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The sensitivity in the IR spectrum of the intact and pathological tissues by laser biophotometry
Abstract
In this paper, we use the laser biophotometry for in vivo investigations, searching the most sensitive interactions of the near-infrared spectrum with different tissues. The experimental methods are based on the average reflection coefficient (ARC) measurements. For healthy persons, ARC is the average of five values provided by the biophotometer. The probe is applied on dry skin with minimum pilosity, in five regions: left-right shank, left-right forearm, and epigastrium. For the pathological tissues, the emitting terminal is moved over the suspected area, controlling the reflection coefficient level, till a minimum value occurs, as ARC-Pathological. Then, the probe is moved on the symmetrical healthy region of the body to read the complementary coefficient from intact tissue, ARC-Intact, from the same patient. The experimental results show an ARC range between 67 and 59 mW for intact tissues and a lower range, up to 58-42 mW, for pathological tissues. The method is efficient only in those pathological processes accompanied by variable skin depigmentation, water retention, inflammation, thrombosis, or swelling. Frequently, the ARC ranges are overlapping for some diseases. This induces uncertain diagnosis. Therefore, a statistical algorithm is adopted for a differential diagnosis. The laser biophotometry provides a quantitative biometric parameter, ARC, suitable for fast diagnosis in the internal and emergency medicine. These laser biophotometry measurements are representatives for the Romanian clinical trials.
... Prevention and monitoring of air pollution are issues of public interest, national and international [21], frequently interfering with healthcare demands and biomedical applications [22,23]. The development of personal computers their spectacular progress in terms of operating speed [24] and storage capacity associated with operating systems and software more and more complete and sophisticated [25,26] is an incentive support for the development of more efficient measurement and monitoring systems [27]. ...
Taking into account that air pollution is one of the most debated issues in the world, this paper proposed a flexible solution for the development a chemical sensor networking able to collect and transmit data for the atmospheric pollutants. The System-Acqusition-Monitoring-Warning-SAMW is composed by a large palette of sensors integrated within Digital Acquisition and Processing System-DAQ, to convert chemical signal in electrical signals easily to be transmitted to a PC server. The air quality monitoring data from different points of map is centralized by a software application. The new proposed software application allows reading, acquisition and monitoring of analogue signals, voltages and currents correlated with the concentrations of main air pollutants. The platform also enables optical and acoustic signalling when the pollutants exceed admissible limits. The application allows both visualization and graphic representation of acquired signals in real time on the computer where is connected the acquisition board. Continuously acquired data are automatically stored in a database to be sent via Internet to a central server for analysis, processing, interpretation and warning. Following these warning, the human operator can take fairly and expeditiously decisions on emerged technological risks. The reported results represent the first map of the cropped pollutants from the atmospheric environment in the Romanian area.
... For diagnosis and disorder monitoring, some considerable efforts were done to introduce some biometric parameters in medicine: average reflection coefficient (ARC) measured by laser bio-photometry [15], thermo-graphic technique in inflammatory processes [16] and others [17][18][19]. New models accompanied by new clinical parameters [20] help to a better patient monitoring, like in the diabetes case [21]. ...
The paper presents a hardware solution of the in vivo electrophysiological signals acquiring and processing, using a continuous data acquisition on PC. The originality of the paper comes from architecture proposal, with some new blocks, which selective amplify and filter biosignals. One of the major problems in the electrophysiological signals monitoring is the impossibility to record the weak signals from deep organs that are covered by noise and by strong cardiac or muscular artefact signals. The analogical processing block is based on a dynamic range compressor, containing the automatic gain control block, so that the high power signals are less amplified than the low components. The following block is a clipper since to capture all the transitions that escape from the dynamic range compressor. At clipper output a low-pass filter is connected since to abruptly cut the high specific bio-frequencies. The data vector recording is performing by strong internal resources microcontroller including ten bits A/D conversion port. Through some specific measurements and calibration the chain can be used to capture and then interprets the neuronal signal with well applications in public health monitoring like psychiatric disorders.
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In order to detect the fluorescence on biological sample still exist extremely elegant solutions that involve high technology of high equipment costs, rather suitable for biomarker discovery in research than routine clinical tests in a very short time.
In this scope, we present a fast real-time application that is running on mobile phones with included optical acquisition system. From the main menu where the application can be configured, as number of samples, colour depth of the camera and picture resolution, all features are automatically filled after a picture is loaded. After the sample selection, some options as re-crop for wrong sample or as start processing will automatically compute the histograms, determine the fluorescence intensity from them, interpolate the logistic curve and show the measured parameters that define the image.
Recently, considerable efforts have been directed towards micro/nanofabrication of two-and three-dimensional devices by two-photon initiated polymerization (2PP). There have been a lot of studies concerning the improvement of the efficiency and precision of 2PP, especially in hybrid methacrylates chemistry (ormosils) capable to generate various compositions with applications in electronics, coatings with tunable properties, drug delivery, biomedical implants and tissue engineering. In this work, substrate adherent and free-standing structures of organic-inorganic polymers were produced via Two Photon Polymerization (2PP) using a Ti: Sapphire laser with the aim to create a suitable scaffold for subsequently tissue engineering applications. The biocompatibility of the resulting materials was tested in L929 mouse fibroblasts to investigate the effect of the polymer structure and its morphology on cells behavior. Cells viability, proliferation and alignment were studied on polymeric structures with different architectures.
Residual pockets are challenging sites that require additional periodontal therapy. The aim of this study was to evaluate the effect of a single photodynamic therapy (PDT) as an adjunct to scaling and root planning (SRP) in residual pockets in single-rooted teeth. A blind, split-mouth, randomized controlled clinical trial was conducted in systemically healthy subjects presenting at least two residual pockets (probing pocket depth (PPD) ≥5 mm with bleeding on probing (BoP)) in single root teeth in supportive periodontal therapy. The selected sites were assigned to receive (1) PDT + SRP or (2) SRP. In sites treated by PDT as adjunctive to SRP, the laser system included a handheld battery-operated diode laser with a wavelength of 660 nm, a power output of 60 mW, and energy density of 129 J/cm(2), together with methylene blue as a photosensitizer (10 mg/ml). Clinical parameters were assessed at baseline and 3 months post-therapies. Clinical parameters improved significantly after both therapies (p < 0.05), whereas higher probing pocket depth reduction and clinical attachment level gain were observed in the PDT + SRP group at 3 months (p < 0.05). In addition, sites treated by the combined approach yielded a significant reduction in the number of sites with PPD <5 mm without BoP after 3 months compared to sites treated by conventional SRP alone (p < 0.05). PDT as an adjunctive to mechanical debridement demonstrated additional clinical benefits for residual pockets in single-rooted teeth and may be an alternative therapeutic strategy in supportive periodontal maintenance.
The quantitative structure – activity relationship in antidiabetic oral drugs has been analyzed on the basis of topological indices that allow to discriminate the structure of different molecules either small or large. The overall correlation structure – activity allows to find the best antidiabetic drugs and to predict the activity of new compound proposed as oral antidiabetic. The screened procedure based on topological indices prevents the expensive and long testing of a high number of compounds.
Diabetes mellitus (DM) and chronic periodontitis are common chronic diseases in adults in the world population. DM has a strong influence on the oral cavity and represents a risk factor for gingivitis and periodontitis. Low-level laser therapy (LLLT) has proven effective in the reduction of inflammation and swelling. The aim of the present study was to evaluate the efficacy of LLLT in diabetic periodontitis through histological analysis. A total of 300 diabetics with chronic periodontal disease and teeth indicated for extraction were assigned into six equal groups. In the groups 1 and 4, indicated teeth were extracted before treatment, and in the rest of the groups upon completion of the entire treatment. All patients received oral hygiene instructions and full-mouth conservative periodontal treatment. In groups 3 and 6, LLLT was applied (670 nm, 5 mW, 2 J/cm(2), 16 min, 5 days). Histologic findings of gingival tissue treated with LLLT showed expressed healing, as is evident by the absence of inflammatory cells. Tissue edema could not be seen, and the number of blood vessels was reduced. In the gingival lamina, propria pronounced collagenization and homogenization were present. It can be concluded that LLLT has shown efficacy in the treatment of periodontitis in diabetics. Because of more pronounced alterations of periodontium in diabetics, the use of LLLT is of particular importance.
During the last three decades, several laser systems, ancillary technologies, and treatment modalities have been developed for the treatment of port wine stains (PWSs). However, approximately half of the PWS patient population responds suboptimally to laser treatment. Consequently, novel treatment modalities and therapeutic techniques/strategies are required to improve PWS treatment efficacy. This overview therefore focuses on three distinct experimental approaches for the optimization of PWS laser treatment. The approaches are addressed from the perspective of mechanical engineering (the use of local hypobaric pressure to induce vasodilation in the laser-irradiated dermal microcirculation), optical engineering (laser-speckle imaging of post-treatment flow in laser-treated PWS skin), and biochemical engineering (light- and heat-activatable liposomal drug delivery systems to enhance the extent of post-irradiation vascular occlusion).
The aim of the study was to examine the role of insulin resistance in etiopathogenesis of metabolic syndrome in an adult Romanian population using exploratory factor analysis. We analyzed 228 non-diabetic subjects randomized in respect to the age and sex distribution of the general population. For each patient, age, sex, body mass index (BMI), systolic and diastolic blood pressure (SBP, DBP), HDL-cholesterol (HDL), plasma triglycerides (TG), fasting plasma glucose (FPG) and fasting insulin were obtained. Factor analysis was performed using principal component analysis, with Varimax rotation of the major determinants of metabolic syndrome. Mean age was 48.9 +/- 12.7 years; 107 (46.9%) were men and 121 (53.1%) women. We found three major factors, which are correlated with metabolic syndrome and may explain its variance. Factor 1 comprises SBP and DBP in men and SBP, DBP and BMI in women. Factor 2 comprises BMI, HDL, TG and FPG in men and BMI, TG and FPG in women. Factor 3 comprises fasting insulin in men and fasting insulin, TG and HDL in women. The finding of more than one factor suggests that insulin resistance is not the only pathophysiological mechanism involved. These factors appear to work independently of each other in men, but they intersect in women, suggesting that the pathophysiology of metabolic syndrome may be different in women compared with men.
Phototherapy stimulates metabolic processes in healing wounds. Despite worldwide interest, phototherapy is not firmly established or practiced in South Africa. This study aimed to determine which dose and wavelength would better induce healing in vitro. Diabetic-induced wounded fibroblasts were irradiated with 5 or 16 J/cm(2) at 632.8, 830, or 1,064 nm. Cellular morphology, viability (Trypan blue and apoptosis), and proliferation (basic fibroblast growth factor) were then determined. Cells irradiated with 5 J/cm(2) at 632.8 nm showed complete wound closure and an increase in viability and basic fibroblast growth factor (bFGF) expression. Cells irradiated at 830 nm showed incomplete wound closure and an increase in bFGF expression. Cells irradiated at 1,064 nm showed incomplete closure and increased apoptosis. All cells irradiated with 16 J/cm(2) at all three wavelengths showed incomplete wound closure, increased apoptosis, and decreased bFGF expression. This study showed that diabetic-wounded cells respond in a dose- and a wavelength-dependent manner to laser light. Cells responded the best when irradiated with a fluence of 5 J/cm(2) at a wavelength of 632.8 nm.
In order to evaluate thermography in exploring the oral mucosa of denture wearers and dentate subjects, a pilot study was conducted where two mobile denture situations and a dentate one were analyzed using infrared thermography. Numerical values corresponding to the thermograms showed an increased temperature underneath prostheses with different distribution in oral mucosa, corresponding to the clinical picture. Thermography can be a non-invasive procedure to assess the oral mucosal status in denture wearers, which can provide important information on prevention, diagnosis and treatment of oral diseases.
Laser speckle contrast imaging (LSCI) is a technique for dynamic visualization of blood flow on tissue surfaces. LSCI produces images of blood flow in real-time using very simple instrumentation without the need for exogenous contrast agents, and has been widely used both in pre-clinical studies of neurological disease as well as clinical applications for monitoring of perfusion. One of the limitations of LSCI is the challenge of obtaining quantitative blood flow information. An extension to LSCI called multi-exposure speckle imaging (MESI) overcomes some of these limitations and enables repeated blood flow measurements to be performed reliably. This chapter describes MESI imaging and the use of LSCI in humans during neurosurgery.
A non-invasive optical method for the characterization of biological tissues using nanoscale FinFET photodetector by wavelet approach has been theoretically developed and presented in this paper. To the best of our knowledge, this approach is the first of its kind for classifying the skin tissue and muscle tissue by determining the surface potential variations of nanoscale FinFET photodetector illuminated by a laser source. The compositional variation of various tissues could be determined by solving the 3-D Poisson-Schrödinger equation using interpolating wavelets. The optical parameters such as absorption and reduced scattering coefficients are also estimated. By this method, the point-to-point variation in tissue composition and structural variation in healthy and diseased tissues could be determined. The results obtained are used to examine the performance of the device for its suitable use as a nanoscale sensor for classification of different tissues.
The aim of this paper is to implement a mathematical predictor algorithm to estimate the health-state evolution versus some measurable index. A relatively new medical tool was used for patients monitoring: the laser close infrared spectrum (850nm) for in vivo interaction with the human tissues. As a main sta-tistic variable was considered the average reflection coefficient, ARC. The determined ARC coefficient in the intact tissues is an index of the health-state, having a range between 55,7 to 68 mW + 2,1 mW, being very stable in time. The determined average reflection coefficient in the pathologically modified tissues constantly decreases from 58 up to 42 mW + 3,4 mW and varies in time according to the evolution of the pathological process. However, the overlap for the ARC ranges occurs among diseases that induce uncertain diagnosis. Therefore a statistical algorithm is favorable. The laser bio-photometry provides the experimental tables that are processed to compute the statistical parameters and to establish a statistic variable. The developed Evaluation function, E, allows the pathological processes finding, besides to the evaluation and monitoring of their evolution.
The modern medicine frequently appeals to the latest news in engineering, informatics or mathematics. One of the challenges is related to the modeling of some phenomena inside the human body that can be valuable instruments for diagnosis and patients monitoring.
The contribution of this paper offers a digital model for the cellular exocytosys and a global model for the in vivo monitoring of insulin concentration after a glycemic stimulus.
The glucose concentration from the human body is regulated by the beta cells activity, via the insulin hormone released into the bloodstream. The insulin exocytosis in 7 steps is modeled as a digital system, expressed as an organigram. The entire physiological behavior is modeled at macro-level, in order to offer a useful tool for diagnosis of diabetes. A simple method for the model parameters extraction, besides to their diagnostic meaning, is provided.
In this paper, design and fabrication of Composite Right/Left-Handed (CRLH) structures for metamaterial based millimeter wave (MMW) devices and circuits are presented. Coplanar waveguide transmission lines working at tens of GHz, were obtained by laser ablation of thin gold films deposied on silicon. The samples are precisely processed by tightly focusing a femtosecond laser beam with 200 fs pulse duration, 775 nm wavelength, energy of hundreds of nJ per pulse, and repetition rate of 2 kHz. A 2D structure is generated by translating the sample according to a computed design. The lateral dimension of the lines removed by the laser from the evaporated film is controlled by adjusting the laser intensity and the focus position. Using this technique, the fabrication of micro-structures for millimeter wave devices is demonstrated.
In this paper, design and fabrication of Composite Right/Left-Handed (CRLH) structures for metamaterial based millimeter wave (MMW) devices and circuits are presented. Coplanar waveguide transmission lines working at tens of GHz, were obtained by laser ablation of thin gold films deposied on silicon. The samples are precisely processed by tightly focusing a femtosecond laser beam with 200 fs pulse duration, 775 nm wavelength, energy of hundreds of nJ per pulse, and repetition rate of 2 kHz. A 2D structure is generated by translating the sample according to a computed design. The lateral dimension of the lines removed by the laser from the evaporated film is controlled by adjusting the laser intensity and the focus position. Using this technique, the fabrication of micro-structures for millimeter wave devices is demonstrated.
Substantial variation across states in the prevalence and trends in childhood overweight and obesity indicate a need for state-specific surveillance to make state comparisons to national estimates and identify high-risk populations. The purpose of this study was to examine body mass index (BMI) trends among third-grade children in Ohio between the 2004-2005 and 2009-2010 school years and examine changes in prevalence of obesity by specific demographic subgroups. Third-grade children (n=33,672) were directly weighed and measured throughout the school years by trained health care professionals. Trends in overweight/obesity (≥85th percentile of BMI by age/sex), obesity (≥95th percentile), and obesity level 2 (≥97th percentile) over five time periods (2004-2005, 2006-2007, 2007-2008, 2008-2009, 2009-2010) were modeled using logistic regression, accounting for the survey design and adjusting for sex, race/ethnicity, National School Lunch Program (NSLP) participation, and age. Differences in these BMI categories were also examined by these subgroups. BMI estimates did not demonstrate a statistically significant trend over the five time periods for overweight/obesity (34% to 36%), obesity (18% to 20%), or obesity level 2 (12% to 14%). However, increases in overweight/obesity prevalence were found in Hispanic children (37.8% vs 53.1%; P<0.01). Decreases in obesity (16.6% vs 14.1%; P=0.02) and obesity level 2 (11.3% vs 9.3%; P=0.02) were found among children not participating in NSLP and residing in suburban counties (obesity [17.3% vs 14.7%; P=0.03] and obesity level 2 [11.8% vs 9.8%; P=0.05]). Finally, decreases in overweight/obesity and obesity level 2 among boys were observed (15% vs 12.9%; P=0.02). Despite no significant overall trends in overweight/obesity, obesity, or obesity level 2 between 2004 and 2010, prevalence changed among specific subgroups. Obesity prevention efforts should be widespread and include special emphasis on groups experiencing increases or no change in prevalence.
The aim of this paper is to implement a mathematical predictor algorithm to estimate the health-state evolution versus some
measurable index. A relatively new medical tool was used for patients monitoring: the laser close infrared spectrum (850nm)
for in vivo interaction with the human tissues. As a main statistic variable was considered the average reflection coefficient,
ARC. The determined ARC coefficient in the intact tissues is an index of the health-state, having a range between 55,7 to
68 mW + 2,1 mW, being very stable in time. The determined average reflection coefficient in the pathologically modified tissues constantly
decreases from 58 up to 42 mW + 3,4 mW and varies in time according to the evolution of the pathological process. However, the overlap for the ARC ranges
occurs among diseases that induce uncertain diagnosis. Therefore a statistical algorithm is favorable. The laser bio-photometry
provides the experimental tables that are processed to compute the statistical parameters and to establish a statistic variable.
The developed Evaluation function, E, allows the pathological processes finding, besides to the evaluation and monitoring
of their evolution.
KeywordsDiagnosis-laser-statistical parameters-diabetes complications
Partial least squares discriminant analysis (PLS-DA) is widely used in multivariate calibration method. Very often, only one single quantitative model is constructed to predict the relationship between the response and the independent variables. This approach can easily misidentify, under or over estimate the important features contained in the independent variables. The results obtained by a single prediction model are thus unstable or correlated to spurious spectral variance, particularly when the training set for PLS-DA is relatively small. A new algorithm developed by applying the Monte Carlo method to PLS-DA, namely MC-PLS-DA, is proposed to classify spectral data obtained from near-infrared blood glucose measurement. Noise in the data is removed by randomly selecting different subsets from the whole training dataset to generate a large number of models. The mean sensitivity and specificity of these models are then calculated to determine the model with the best classification rate. The results show that the MC-PLS-DA method gives more accurate prediction results when compared with other classification methods used for classifying near infrared spectroscopic data of blood glucose. Also, the stability of the PLS-DA model is enhanced.
Gold-gold sulfide nanoparticles (GGS-NPs) fabricated from chloroauric acid and sodium thiosulfate show unique near infrared (NIR) absorption that renders them as a promising candidate for photothermal cancer therapy. To improve targeting efficiency, we developed a versatile method to allow ordered immunoconjugation of antibodies on the surfaces of these nanoparticles via a PEGylated recombinant Protein G (ProG). The PEGylated ProG was prepared with orthopyridyldisulfide-polyethylene glycol-succinimidyl valerate, average MW 2000 (OPSS-PEG-SVA), to first allow the self-assembly of ProG on the nanoparticles, subsequently antibodies were added to this construct to enable active targeting. The bioconjugated GGS-NPs were characterized by TEM, NIR-spectra, dynamic light scattering and modified immunoassay. In in vitro studies, the ProG-conjugated GGS-NPs with bound mouse anti c-erbB-2 (HER-2) immunoglobulin G (IgG) successfully targeted the HER-2 overexpressing breast cancer cell, SK-BR-3. Extensive cell death was observed for the targeted SK-BR-3 line at a low laser power of 540 J (3 W cm(-2) for 3 min) while the control breast cancer cell (low expressing HER-2), HTB-22 survived. Using PEGylated ProG as a cofactor for immobilization of antibodies offers a promising strategy to functionalize various IgGs on nanoparticles for engineering their biomedical applications in cancer therapeutics.
Liposomes have been actively studied as models of cell membranes and are currently used as drug delivery systems of bioactive molecules. Liposome transformations that mimic cellular processes and are associated with their physicochemical properties have become field of interest the last decade. However, there has been little experimental work on controlled vesicle transformations by non-contact, optical handling methods.In this paper we present the use of line optical tweezers to observe liposome state transitions and transformations. Dynamic shape deformations were induced by line optical tweezers in giant stained liposomes leading to budding transition, fission and pearling creation. Under the controlled effect of line optical tweezers reversible liposome deformations were observed. The shear modulus μ of the membrane was inferred by measuring deformation of stained liposomes induced by the applied optical force. Further laser radiation caused irreversible shape deformations of liposomes, which were transformed from spherical to tubular vesicles. The ability of the selective manipulation of liposomes brings us closer to study their physicochemical properties which play a key role in cellular–liposome interactions, drug encapsulation and delivery efficiency.
Photodynamic therapy has been investigated as an alternative method of killing pathogens in response to the multiantibiotic resistance problem. This study evaluated the photodynamic effect of curcumin on methicillin-resistant Staphylococcus aureus (MRSA) compared to susceptible S. aureus (MSSA) and L929 fibroblasts. Suspensions of MSSA and MRSA were treated with different concentrations of curcumin and exposed to light-emitting diode (LED). Serial dilutions were obtained from each sample, and colony counts were quantified. For fibroblasts, the cell viability subsequent to the curcumin-mediated photodynamic therapy was evaluated using the MTT assay and morphological changes were assessed by SEM analysis. Curcumin concentrations ranging from 5.0 to 20.0 μM in combination with any tested LED fluences resulted in photokilling of MSSA. However, only the 20.0 μM concentration in combination with highest fluence resulted in photokilling of MRSA. This combination also promoted an 80% reduction in fibroblast cell metabolism and morphological changes were present, indicating that cell membrane was the main target of this phototherapy. The combination of curcumin with LED light caused photokilling of both S. aureus strains and may represent an alternative treatment for eradicating MRSA, responsible for significantly higher morbidity and mortality and increased healthcare costs in institutions and hospitals.
The 2,790 nm Er:YSGG wavelength has a lower water absorption coefficient than the 2,940 nm Er:YAG, but a higher coefficient than the 10,600 nm CO(2) laser. This allows ablative resurfacing with mild thermal coagulation, which may increase clinical efficacy while reducing patient downtime.
To evaluate the efficacy and safety of the confluent 2,790 nm Erbium:YSGG (Pearl™, Cutera) laser for facial rejuvenation.
Eleven subjects (mean age 50, skin types I-III) with mild to moderate photodamage and wrinkles had two facial treatments with the 2,790 nm Er:YSGG laser using a fluence of 3.5 J/cm(2), pulse duration of 0.4 msecond, and 20% overlap. Treatments were performed 6 weeks apart. Pre-auricular biopsies from five subjects were evaluated at baseline and 6 weeks after the final treatment. Data from blinded photo assessments and subjects' self-assessment of improvement were analyzed 6 weeks after the final treatment. Additionally, long-term safety and efficacy were evaluated 2 years after the final treatment.
Histologically, 80% of subjects had new collagen formation in the dermal grenz zone, and 60% had increased epidermal thickness. Almost all subjects (91%) showed improvement in tone/texture, 82% of subjects showed improvement in dyschromia and fine lines, and 54% showed improvement in wrinkles 6 weeks after the final treatment. Subjects' self assessment indicated "significant" to "dramatic" improvement in dyschromia (91% of subjects) and tone/texture (82%) 6 weeks after the final treatment. All subjects saw "mild" to "significant" improvement in fine lines and wrinkles. At the 2-year follow-up visit, 57% of the overall improvement achieved at 6 weeks was maintained. No adverse events were reported throughout the study.
Ablative resurfacing with the 2,790 nm Er:YSGG laser demonstrated visible improvement in photodamage with good tolerability and minimal downtime. Subjects were highly satisfied, especially with respect to dyschromia, skin tone, and texture.
The tools and techniques developed for analytical cytology have become invaluable in expanding the development of cancer screening programs and biomarker discovery for personalized medicine. Detecting cellular, molecular, and functional changes of diseased tissue as defined by quantitative analytical methodologies has enhanced the field of medical diagnostics and prognostics. The focus of this review is to outline applications and recent technical advances in flow cytometry, laser scanning cytometry, image cytometry, and quantitative image analysis, as they pertain to clinical, research, and drug discovery applications.
The pulsed dye laser (PDL) using varying fluences and pulse durations have been used to treat hemangiomas. This study aims to examine the efficacy and safety of the 595-nm PDL for the treatment of infantile hemangiomas using short (1.5-3 milliseconds) versus long (10 milliseconds) pulse durations and high fluences.
This is a retrospective study of patients with hemangiomas (n = 23) treated with the 595-nm PDL from 2003 to 2007. The parameters used for the short pulse duration group (n = 15) were 7-mm spot size, fluence 10-13.5 J/cm(2) and dynamic cooling device (DCD) spray duration of 50 milliseconds and delay of 30 milliseconds. For the long pulse duration group (n = 8), parameters were 7-mm spot size, fluence 10.5-14.5 J/cm(2) and DCD spray duration of 40 milliseconds and delay of 20 milliseconds.
The number of treatments required to achieve complete or near complete resolution of the hemangioma ranged from 3 to 14 for the short pulse duration group (mean: 8) and for the long pulse duration group, 4-14 treatments (mean: 9). For both groups, more treatments were needed to achieve clearance of mixed hemangiomas (n = 13) compared to superficial hemangiomas (n = 10) (on average, 4-5 treatments more). Erythema, edema, and purpura lasted for about a week in the short pulse duration group but only 2 days in the long pulse duration group. There was no ulceration or hypertrophic scarring noted in both groups.
Both short and long pulse durations using moderately high fluences are equally effective in the treatment of infantile hemangiomas. Shorter pulse durations had a slightly higher incidence of side effects compared to longer pulse duration in our patients with darker phototypes. Hemangiomas are tumors with relatively large diameter blood vessels and this provides the basis for the use of longer pulse durations.
Femurs are the heaviest, longest, and strongest long bones in the human body and are routinely subjected to cyclic forces. Strain gages are commonly employed to experimentally validate finite element models of the femur in order to generate 3D stresses, yet there is little information on a relatively new infrared (IR) thermography technique now available for biomechanics applications. In this study, IR thermography validated with strain gages was used to measure the principal stresses in the artificial femur model from Sawbones (Vashon, WA, USA) increasingly being used for biomechanical research. The femur was instrumented with rosette strain gages and mechanically tested using average axial cyclic forces of 1500N, 1800N, and 2100N, representing 3 times body weight for a 50kg, 60kg, and 70kg person. The femur was oriented at 7° of adduction to simulate the single-legged stance phase of walking. Stress maps were also obtained using an IR thermography camera. Results showed good agreement of IR thermography vs. strain gage data with a correlation of R(2)=0.99 and a slope=1.08 for the straight line of best fit. IR thermography detected the highest principal stresses on the superior-posterior side of the neck, which yielded compressive values of -91.2MPa (at 1500N), -96.0MPa (at 1800N), and -103.5MPa (at 2100N). There was excellent correlation between IR thermography principal stress vs. axial cyclic force at 6 locations on the femur on the lateral (R(2)=0.89-0.99), anterior (R(2)=0.87-0.99), and posterior (R(2)=0.81-0.99) sides. This study shows IR thermography's potential for future biomechanical applications.
Laser speckle contrast imaging (LSCI) has emerged over the past decade as a powerful, yet simple, method for imaging of blood flow dynamics in real time. The rapid adoption of LSCI for physiological studies is due to the relative ease and low cost of building an instrument as well as the ability to quantify blood flow changes with excellent spatial and temporal resolution. Although measurements are limited to superficial tissues with no depth resolution, LSCI has been instrumental in pre-clinical studies of neurological disorders as well as clinical applications including dermatological, neurosurgical and endoscopic studies. Recently a number of technical advances have been developed to improve the quantitative accuracy and temporal resolution of speckle imaging. This article reviews some of these recent advances and describes several applications of speckle imaging.
The aim of this trial was to investigate changes occurring in the subgingival microbiological composition of subjects with aggressive periodontitis, treated with antimicrobial photodynamic therapy (aPDT), in a single episode, or scaling and root planing (SRP), in a split-mouth design on -7, 0, and +90 days. Ten patients were randomly assigned to either aPDT using a laser source in conjunction with a photosensitizer or SRP with hand instruments. Subgingival plaque samples were collected and the counts of 40 subgingival species were determined using checkerboard DNA-DNA hybridization. The data were analyzed using the method of generalized estimating equations (GEE) to test the associations between treatments, evaluated parameters, and experimental times (α = .05). The results indicated that aPDT and SRP affects different bacterial species, with aPDT being effective in reducing numbers of A. actinomycetemcomitans than SRP. On the other hand, SRP was more efficient than aPDT in reducing the presence of periodontal pathogens of the Red Complex. Additionally, a recolonization in the sites treated by aPDT was observed, especially for T. forsythia and P. gingivalis. Under our experimental conditions, this trial demonstrates that aPDT and SRP affected different groups of bacteria, suggesting that their association may be beneficial for the non-surgical treatment of aggressive periodontitis.
Liposomes applications in health care include meanly their ability to carry drugs and genes inside the human body for therapeutic purposes. Nevertheless their applicability can extend far beyond and could be used as analytical tools in order to perform rapid, low-cost, sensitive and specific analyses. Their physical characteristics, such as large internal volume and extended surface area, render them ideal for these applications and specifically for improving the specificity and sensitivity of the analytical assay. The purpose of this study was to develop a simple, stable and low-cost oligonucleotide-tagged liposomal formulation consisting of EggPC and DPPG with a simple to synthesize thiol-reactive conjugate (Mal-SA) incorporated into the lipid bilayer of liposomes. The prepared liposomes, having also the water soluble dye Sulforhodamine B encapsulated in their inner cavity, were characterized in terms of their physicochemical (size, size distribution, zeta-potential, lipid content) and mechanical (morphology, rigidity) properties. The results showed that the final liposomal formulation could be used in the future as analytical tool for detecting pathogen strains of microorganism in biological milieu.
Chemical and electrical interaction within and between cells is well established. Just the opposite is true about cellular interactions via other physical fields. The most probable candidate for an other form of cellular interaction is the electromagnetic field. We review theories and experiments on how cells can generate and detect electromagnetic fields generally, and if the cell-generated electromagnetic field can mediate cellular interactions. We do not limit here ourselves to specialized electro-excitable cells. Rather we describe physical processes that are of a more general nature and probably present in almost every type of living cell. The spectral range included is broad; from kHz to the visible part of the electromagnetic spectrum. We show that there is a rather large number of theories on how cells can generate and detect electromagnetic fields and discuss experimental evidence on electromagnetic cellular interactions in the modern scientific literature. Although small, it is continuously accumulating.
Microtubules are electrically polar structures fulfilling prerequisites for generation of oscillatory electric field in the kHz to GHz region. Energy supply for excitation of elasto-electrical vibrations in microtubules may be provided from GTP-hydrolysis; motor protein-microtubule interactions; and energy efflux from mitochondria. We calculated electric field generated by axial longitudinal vibration modes of microtubules for random, and coherent excitation. In case of coherent excitation of vibrations, the electric field intensity is highest at the end of microtubule. The dielectrophoretic force exerted by electric field on the surrounding molecules will influence the kinetics of microtubule polymerization via change in the probability of the transport of charge and mass particles. The electric field generated by vibrations of electrically polar cellular structures is expected to play an important role in biological self-organization.
Noninvasive and real-time analysis of skin properties is useful in a wide variety of applications. In particular, the quantitative assessment of skin in terms of hemoglobin and melanin content, as well as in terms of its light scattering properties, is a challenging problem in dermatology. We present here a technique for examining human skin, based on the in vivo measurement of diffuse reflectance spectra in the visible and near-infrared ranges of the electromagnetic spectrum. Spectra were measured by means of a fiber optic probe, and they were analyzed using an analytical model of light diffusion in the skin. The results of the analysis indicate that it is possible to obtain quantitative information about hemoglobin and melanin content, as well as basic information regarding the scattering properties of the skin.
The capacities of laser biophotometry in the diagnosis of tuberculous spondylitis and its complications were studied in 42 patients with this disease and in controls. There was a definite significant trend of changes in the reflection coefficient of a laser signal in patients with an active inflammatory process in the vertebrae, which makes it possible to establish a differential diagnosis of the above conditions and to determine the time course of changes in the specific process in the vertebral column during therapy. Comparative analysis of the proposed method with the thermographic technique used in clinical practice demonstrated that the validity of laser biophotometry was highly competitive with that of thermography.
We describe a young man with acute portal vein thrombosis (PVT) and cytomegalovirus (CMV) infection, and we review the literature
regarding the association between PVT and CMV in immunocompetent patients. Published data suggest that CMV hepatitis and,
possibly, other types of acute viral hepatitis could be a local risk factor for acute PVT.
Diagnostic capacities of laser biophotometry in tuberculosis of the vertebral column
- Sokolov Me
- Yo
- Alekseyev Yv
- Degrave Tv
- Afonin
- Av
Sokolov ME, Peretsmanas YO, Alekseyev YV, Degrave TV, Afonin AV (2002) Diagnostic capacities of laser biophotometry in tuberculosis of the vertebral column. Probl Tuberk 9:25–27 [in Russian]
Laser bio-photometry-methods of diagnosis and prognosis of inflammatory diseases of uterine appendages
- A M Torchinov
- A Isaev
- G M Engoyants
- AM Torchinov
Sveto-Lazernaia Diagnostika I Terpia v Acusherstve I Ginecologhii. Ministerstvo zdravohronenia Rossiiskoi Federatii
- A K Isaev
- A Torchinov
- M Uhmanova
Special mathematics, chapter 2 probabilities and statistical mathematics
- V Olariu
- V Prepelita
Bio-physics basics of physiotherapy
- G N Ponomarenco
- I I Turcovski
Clinical laser bio-photometry
- M T Alexandrov
- MT Alexandrov
An extension to the discriminant analysis of near-infrared spectra
- C F So
- K S Choi
- Jwy Chung
- Tks Wong
- CF So
The adjunctive effect of photodynamic therapy for residual pockets in single-rooted teeth: a randomized controlled clinical trial
- F V Ribeiro
- Rcv Casarin
- F R Cirano
- Chc Saraceni
- M Z Casati
- FV Ribeiro