[show abstract][hide abstract] ABSTRACT: Gallbladder carcinoma (GBC) is a relatively rare disease which pathogenesis is less clarified. Human antigen R (HuR), a RNA-binding protein, modulates the expressions of various cancer-related proteins by stabilizing or regulating the transcription of the corresponding messenger RNA. The significance of HuR expression in a large cohort with GBCs is yet to be evaluated. In total, 164 cases of GBC were selected, and immunostaining for HuR was performed. HuR nuclear (HuR-N) expression and HuR cytoplasmic (HuR-C) expression were evaluated by using a histochemical score. The results of HuR expression were correlated with various clinicopathological factors, disease-specific survival (DSS), and disease-free survival (DFS) in 161 patients with follow-up data. HuR-N overexpression was strongly associated with high histological grade (p = 0.001), vascular invasion (p < 0.001), and high Ki-67 labeling index (p < 0.001). HuR-C overexpression was significantly related to higher primary tumor status (p < 0.001), advanced tumor stage (p < 0.001), histological type (p = 0.006), high histological grade (p < 0.001), vascular and perineurial invasion (p < 0.001 and p = 0.002, respectively), tumor necrosis (p = 0.042), and high Ki-67 labeling index (p = 0.002). Besides, HuR-C overexpression also correlates with HuR-N overexpression (p < 0.001) and cyclin A overexpression (p = 0.026). HuR-N overexpression correlated with poor DFS (p = 0.0348) in univariate analysis, but HuR-C overexpression strongly correlated with a worse DSS and DFS in both univariate (both p < 0.0001) and multivariate (DSS, p = 0.006; DFS, p = 0.001) analyses. Subcellular localization of HuR expression correlates with different adverse phenotypes of GBC. Besides, HuR-C overexpression is an independent prognostic factor for dismal DSS and DFS, suggesting its roles in tumorigenesis or carcinogenesis and as a potential prognostic marker of GBC.
[show abstract][hide abstract] ABSTRACT: BACKGROUND: The volume-outcome relationship has been validated previously for surgical procedures and cancer treatments. However, no studies have longitudinally compared the relationships between volume and outcome, and none have systematically compared laparoscopic cholecystectomy (LC) surgery outcomes in Taiwan. This study purposed to explore the relationship between volume and hospital treatment cost after LC. METHODS: This cohort study retrospectively analyzed 247,751 LCs performed from 1998 to 2009. Hospitals were classified as low-, medium-, and high-volume hospitals if their annual number of LCs were 1-29, 30-84, ≥85, respectively. Surgeons were classified as low-, medium-, and high-volume surgeons if their annual number of LCs were 1-10, 11-24, ≥25, respectively. Hierarchical linear regression model and propensity score were used to assess the relationship between volume and hospital treatment cost. RESULTS: The mean hospital treatment cost was US $2,504.53, and the average hospital costs for high-volume hospitals/surgeons were 33/47 % lower than those for low-volume hospitals and surgeons. When analyzed by propensity score, the hospital treatment cost differed significantly between high-volume hospitals/surgeons and low/medium-volume hospitals/surgeons (2,073.70 vs. 2,350.91/2,056.73 vs. 2,553.76, P < 0.001). CONCLUSIONS: Analysis using a hierarchical linear regression model and propensity score found an association between high-volume hospitals and surgeons and hospital treatment cost in LC patients. Moreover, the significant factors associated with hospital resource utilization for this procedure include age, gender, comorbidity, hospital type, hospital volume, and surgeon volume. Additionally, analysis of the treatment strategies adopted at high-volume hospitals or by high-volume surgeons may improve overall hospital treatment cost.
[show abstract][hide abstract] ABSTRACT: The S-phase kinase-associated protein 2 (SKP2) oncoprotein is an E3 ubiquitin ligase. Overexpression of SKP2 was found in various human cancers, including colorectal cancers, but its potential role as a prognostic marker after neoadjuvant chemoradiotherapy (CRT) and for therapeutic intervention in rectal cancers is unknown. This study examined the correlation of SKP2 expression in the prognosis of rectal cancer patients and the viability of colorectal cancer cells treated with CRT. SKP2 immunoexpression was retrospectively assessed in pretreatment biopsies of 172 rectal cancer patients treated with neoadjuvant CRT followed by surgery. Results were correlated with clinicopathological features, therapeutic responses, and patient survival. Pharmacologic assays were used to evaluate the therapeutic relevance of Bortezomib in two colorectal cancer cell lines (HT-29 and SW480). High expression of SKP2 was correlated with the advanced Post-Tx nodal status (p = 0.002), Post-Tx International Union for Cancer Control stage (p = 0.002), and a lower-degree tumor regression grade (p < 0.001). Moreover, high expression of SKP2 (p = 0.027, hazard ratio 3.21) was an independent prognostic factor for local recurrence-free survival. In vitro, Bortezomib downregulated SKP2 expression, induced caspase activation, and decreased the viability of colorectal cancer cells with or without a combination with fluorouracil. Bortezomib also promoted caspase activation and gamma-H2AX formation in colorectal cancer cells concurrently treated with CRT. High expression of SKP2 was associated with a poor therapeutic response and adverse outcomes in rectal cancer patients treated with neoadjuvant CRT. In the presence of chemotherapy with or without radiotherapy, the promoted sensitivity of colorectal cancer cells to Bortezomib with an SKP2-repressing effect indicated that it is a potential therapeutic target.
[show abstract][hide abstract] ABSTRACT: BACKGROUND: To validate the use of artificial neural network (ANN) models for predicting 5-year mortality in HCC and to compare their predictive capability with that of logistic regression (LR) models. METHODS: This study retrospectively compared LR and ANN models based on initial clinical data for 22,926 HCC surgery patients from 1998 to 2009. A global sensitivity analysis was also performed to assess the relative significance of input parameters in the system model and to rank the importance of variables. RESULTS: Compared to the LR models, the ANN models had a better accuracy rate in 96.57 % of cases, a better Hosmer-Lemeshow statistic in 0.34 of cases, and a better receiver operating characteristic curves in 88.51 % of cases. Surgeon volume was the most influential (sensitive) parameter affecting 5-year mortality followed by hospital volume and Charlson co-morbidity index. CONCLUSIONS: In comparison with the conventional LR model, the ANN model in this study was more accurate in predicting 5-year mortality. Further studies of this model may consider the effect of a more detailed database that includes complications and clinical examination findings as well as more detailed outcome data.
Journal of Gastrointestinal Surgery 08/2012; · 2.36 Impact Factor
[show abstract][hide abstract] ABSTRACT: Neoadjuvant chemoradiation therapy (CRT) is an increasingly used therapeutic strategy for rectal cancer. Clinically, it remains a major challenge to predict therapeutic response and patient outcome after CRT. Rsf-1 (HBXAP), a novel nuclear protein with histone chaperon function, mediates ATPase-dependent chromatin remodelling and confers tumour aggressiveness and predicts therapeutic response in certain carcinomas. However, the expression of Rsf-1 has never been reported in rectal cancer. This study examined the predictive and prognostic impacts of Rsf-1 expression in patients with rectal cancer following neoadjuvant CRT.
Rsf-1 immunoexpression was retrospectively assessed for pre-treatment biopsies of 172 rectal cancer patients without initial distant metastasis. All of them were treated with neoadjuvant CRT followed by surgery. The results were correlated with the clinicopathological features, therapeutic response, tumour regression grade and metastasis-free survival (MeFS), local recurrent-free survival and disease-specific survival.
Present in 82 cases (47.7%), high-expression of Rsf-1 was associated with advanced pre-treatment tumour status (T3, T4, p=0.020), advanced post-treatment tumour status (T3, T4, p<0.001) and inferior tumour regression grade (p=0.028). Of note, high-expression of Rsf-1 emerged as an adverse prognosticator for diseases-specific survival (p=0.0092) and significantly predicted worse MeFS (p=0.0006). Moreover, high-expression of Rsf-1 also remained prognostic independent for worse MeFS (HR 2.834; p=0.0214).
High-expression of Rsf-1 is associated with poor therapeutic response and adverse outcome in rectal cancer patients treated with neoadjuvant CRT, which confers tumour aggressiveness and therapeutic resistance through chromatin remodelling and represents a potential prognostic biomarker in rectal cancer.
Journal of clinical pathology 05/2012; 65(8):687-92. · 2.43 Impact Factor
[show abstract][hide abstract] ABSTRACT: Few studies of laparoscopic cholecystectomy (LC) outcome have used longitudinal data for more than two years. Moreover, no studies have considered group differences in factors other than outcome such as age and nonsurgical treatment. Additionally, almost all published articles agree that the essential issue of the internal validity (reproducibility) of the artificial neural network (ANN), support vector machine (SVM), Gaussian process regression (GPR) and multiple linear regression (MLR) models has not been adequately addressed. This study proposed to validate the use of these models for predicting quality of life (QOL) after LC and to compare the predictive capability of ANNs with that of SVM, GPR and MLR.
A total of 400 LC patients completed the SF-36 and the Gastrointestinal Quality of Life Index at baseline and at 2 years postoperatively. The criteria for evaluating the accuracy of the system models were mean square error (MSE) and mean absolute percentage error (MAPE). A global sensitivity analysis was also performed to assess the relative significance of input parameters in the system model and to rank the variables in order of importance. Compared to SVM, GPR and MLR models, the ANN model generally had smaller MSE and MAPE values in the training data set and test data set. Most ANN models had MAPE values ranging from 4.20% to 8.60%, and most had high prediction accuracy. The global sensitivity analysis also showed that preoperative functional status was the best parameter for predicting QOL after LC.
Compared with SVM, GPR and MLR models, the ANN model in this study was more accurate in predicting patient-reported QOL and had higher overall performance indices. Further studies of this model may consider the effect of a more detailed database that includes complications and clinical examination findings as well as more detailed outcome data.
PLoS ONE 01/2012; 7(12):e51285. · 3.73 Impact Factor
[show abstract][hide abstract] ABSTRACT: Since most published articles comparing the performance of artificial neural network (ANN) models and logistic regression (LR) models for predicting hepatocellular carcinoma (HCC) outcomes used only a single dataset, the essential issue of internal validity (reproducibility) of the models has not been addressed. The study purposes to validate the use of ANN model for predicting in-hospital mortality in HCC surgery patients in Taiwan and to compare the predictive accuracy of ANN with that of LR model.
Patients who underwent a HCC surgery during the period from 1998 to 2009 were included in the study. This study retrospectively compared 1,000 pairs of LR and ANN models based on initial clinical data for 22,926 HCC surgery patients. For each pair of ANN and LR models, the area under the receiver operating characteristic (AUROC) curves, Hosmer-Lemeshow (H-L) statistics and accuracy rate were calculated and compared using paired T-tests. A global sensitivity analysis was also performed to assess the relative significance of input parameters in the system model and the relative importance of variables. Compared to the LR models, the ANN models had a better accuracy rate in 97.28% of cases, a better H-L statistic in 41.18% of cases, and a better AUROC curve in 84.67% of cases. Surgeon volume was the most influential (sensitive) parameter affecting in-hospital mortality followed by age and lengths of stay.
In comparison with the conventional LR model, the ANN model in the study was more accurate in predicting in-hospital mortality and had higher overall performance indices. Further studies of this model may consider the effect of a more detailed database that includes complications and clinical examination findings as well as more detailed outcome data.
PLoS ONE 01/2012; 7(4):e35781. · 3.73 Impact Factor
[show abstract][hide abstract] ABSTRACT: The prevalence of symptomatic gallbladder diseases increases with age. The present study evaluated cholecystectomy risk factors and hospital resource utilization in an elderly (aged 60 years and older) population of patients who had undergone open cholecystectomy (OC) or laparoscopic cholecystectomy (LC).
The study analyzed 20,538 OC and 29,318 LC procedures performed in Taiwan from 1996 to 2007. Odds ratio (OR) and 95% confidence interval were calculated to assess the relative change rate. Regression models were employed to predict length of stay (LOS) and total surgical cost.
Patient characteristics associated with increased likelihood of undergoing LC were age 60-69 years, female gender, and lack of current co-morbidities. Length of stay associated with both OC and LC decreased during the study period. Total surgical cost for elderly OC patients increased during the study period, whereas that for elderly LC patients declined. Compared to OC patients, LC patients had significantly larger changes in LOS (-2.27 days) and total surgical cost ($ -368.64 U.S. dollars) (p < 0.001). The following factors were associated with considerable increases in both LOS and total surgical cost: advanced age, female gender, presence of one or more co-morbidities, treatment in a regional or a district hospital, and long LOS.
Decreases in hospital resource utilization were larger in elderly LC patients than in elderly OC patients. Health care providers and patients should observe that hospital resource utilization may depend on hospital attributes as well as patient attributes. These analytical results should be applicable to similar elderly populations in other countries.
World Journal of Surgery 12/2010; 34(12):2922-31. · 2.23 Impact Factor
[show abstract][hide abstract] ABSTRACT: The objectives of this study were to examine longitudinal time trends, to predict thresholds of improvement in each dimension of health-related quality of life (HRQoL), and to identify long-term predictors of HRQoL.
This study analyzed 353 laparoscopic cholecystectomy (LC) patients. Disease-specific Gastrointestinal Quality-of-Life Index (GIQLI) and generic Short-Form 36-Item Health Survey (SF-36) scores were obtained immediately before surgery, then 3, 6, 12, and 24 months after surgery. Generalized estimating equations and piecewise linear regression models were used.
The examined population significantly (p<0.05) improved in both SF-36 and GIQLI subscale scores. The HRQoL dimensions were substantially improved the sixth month after surgery and continued improving until they reached a plateau at 54.93 to 73.18 months. The data also showed the following explanatory variables for HRQoL: time, age, gender, Charlson Comorbidity Index, and preoperative GIQLI and SF-36 subscale scores.
As shown by the findings, the HRQoL scores improved substantially by the sixth month after surgery and continued improving until they reached a 4- to 7-year threshold, indicating that change trends in HRQoL dimensions may vary. Although HRQoL scores were substantially improved after cholecystectomy, the improvements were associated with preoperative functional status and demographic characteristics.
[show abstract][hide abstract] ABSTRACT: Traditional pre- and post-surgery quality of life assessments are inadequate for assessing change in health-related quality of life (HRQoL) after laparoscopic cholecystectomy (LC). This study examined whether a response shift, a change in the internal standards of a patient, occurs in patients who have received LC.
Self-administered gastrointestinal quality of life index (GIQLI) was used to evaluate preoperative, postoperative, and retrospective postoperative HRQoL. Response shifts, unadjusted treatment effects, adjusted treatment effects, and their effect sizes were calculated.
In all GIQLI domains, a significant response shift was indicated by the significantly higher pre-test scores compared to then-test scores (P < 0.05). The effect size of the response shift ranged from 0.19 for the physical impairment domain of the GIQLI to 0.49 for the total GIQLI score. It was observed the treatment effect was greater after adjusting for the presence of response shift.
Patients who have received LC undergo a response shift that affects their outcome measurement at 6 months postoperative. Response shift is a potentially confounding factor and should be considered when designing clinical studies that employ self-administered HRQoL measures. This evidence of confounding effects warrants further study of response shift at longer intervals after LC, after other health care interventions, and in patients with varying preoperative health status.
Quality of Life Research 10/2010; 20(3):335-41. · 2.41 Impact Factor
[show abstract][hide abstract] ABSTRACT: This study analyzed patient demographics and preoperative functional status for associations with post-cholecystectomy quality of life (QOL).
This prospective study analyzed 159 cholecystectomy patients at two tertiary academic hospitals. All patients completed the SF-36 and the gastrointestinal quality of life index (GIQLI) at baseline and at 3 and 6 months postoperatively. The 95% confidence intervals for differences in responsiveness estimates were derived by bootstrap estimation. Scores derived by these instruments were interpreted by generalized estimating equation (GEE) before and after cholecystectomy.
The examined population significantly (p < 0.05) improved in both SF-36 subscales and GIQLI subscales. After adjusting for time effects (time, and time(2)) and baseline predictors, GEE approaches revealed the following explanatory variables for QOL: time, time(2), age, gender, preoperative GIQLI score, body mass index, and number of comorbidities.
The data revealed dramatically improved post-cholecystectomy QOL. However, QOL change was simultaneously associated with preoperative functional status and demographic characteristics.
Journal of Gastrointestinal Surgery 10/2009; 13(9):1651-8. · 2.36 Impact Factor
[show abstract][hide abstract] ABSTRACT: The minimal clinically important difference (MCID) for the Gastrointestinal Quality of Life Index (GIQLI) is unknown, which limits its application and interpretation. This study aimed to estimate MCIDs for the GIQLI scores of patients after they had undergone cholecystectomy.
This study had 267 participants. All the participants completed the GIQLI and four anchor items, namely, "How would you describe your overall symptoms, emotions, physical functions, and social functions since your last visit?" The response options were "much worse," "somewhat worse," "same," "somewhat better" and "much better." The MCID was defined according to those who responded with "somewhat better."
The mean age of the participants was 57.81 ± 14.93 years, and 37.08% of the patients were women. The MCID group included 67, 78, 44, and 22 patients with MCIDs of 6.42, 6.86, 7.64 and 6.46 points respectively for scores on the symptoms, emotions, physical functions, and social functions subscales, respectively. The effect sizes of four anchors in the "somewhat better" group (0.38-0.49) exceeded those of the same group (0.25-0.38).
This study showed that after patients had undergone cholecystectomy, the clinically significant mean changes in their scores on the GIQLI subscales for symptoms, emotions, physical functions, and social function were respectively 6.42, 6.86, 7.64, and 6.46 points. After patients have undergone cholecystectomy, the MCIDs for the GIQLI subscales can play an important role in interpretation of the scores, application of them in clinical practice, and verification of treatment effects.
[show abstract][hide abstract] ABSTRACT: Up-regulation of Wnt-1 protein has been reported in hepatitis B virus (HBV)-related and hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC) tissues and cell lines. It is known to play a fundamental role in signaling cancer progression, whereas its prognostic role in HCC remains unexplored.
As a prognostic biomarker, this study analyzed Wnt-1 protein expression in 63 histology-verified HCC patients receiving curative resection. In each paired tumor and nontumor specimen, Wnt-1 levels were semiquantitatively measured by Western blotting and expressed by tumor/nontumor ratio. The data were further correlated with quantitative real-time PCR as well as with beta-catenin and E-cadherin expression by immunohistochemistry. Cumulative tumor recurrence-free survival curves were constructed using the Kaplan-Meier method and compared by the log-rank test.
The results showed that 26 (group I) and 37 (group II) HCC patients had an expression ratio of Wnt-1 > or =1.5 and <1.5, respectively. The amount of Wnt-1 estimated by tumor/nontumor ratio correlated with the results by quantitative real-time PCR. High tumor Wnt-1 expression correlated with enhanced nuclear beta-catenin accumulation, diminished membranous E-cadherin expression, and increased tumor recurrence after curative tumor resection.
These results suggest that Wnt-1 may be used as a predisposing risk factor for HCC recurrence. The use of tumor Wnt-1 as prognostic biomarker may identify patients with HBV- and/or HCV-related HCC patients with a high risk of tumor recurrence who may then benefit from further intensive therapy after surgery.
[show abstract][hide abstract] ABSTRACT: To compare responsiveness and minimal clinically important differences (MCID) between the Gastrointestinal Quality of Life (GIQLI) and the Short Form 36 (SF-36), we prospectively analyze 159 patients undergoing cholecystectomy at two tertiary academic hospitals.
All patients completed the disease-specific GIQLI and the generic SF-36 before and 3 months after surgery. Scores using these instruments were interpreted by generalized estimating equation before and after cholecystectomy. The bootstrap estimation was used to derive 95% confidence intervals for differences in the responsiveness estimates.
Mean changes in all GIQLI and the SF-36 subscales were statistically significant (p < 0.05). Comparisons of effect size (ES), standardized response means (SRM), and relative efficiency (>1) indicated that the responsiveness of the GIQLI was superior to that of the SF-36. In the equivalence test, all lower or upper confidence limits presented no equivalence (>5), indicating good MCID. The ES and SRM for emotions and physical function in the GIQLI significantly differed from those of the SF-36 (p < 0.05).
The data in this study indicate that clinicians and health researchers should weight disease-specific measures more heavily than generic measures when evaluating treatment outcomes.
Journal of Gastrointestinal Surgery 07/2008; 12(7):1275-82. · 2.36 Impact Factor
[show abstract][hide abstract] ABSTRACT: The link of proto-oncogenic protein Wnt-1 production with NF-kappaB activation has been functionally demonstrated in PC12 cells, a rat pheochromocytoma cell line of neural crest lineage, while it is not yet verified in human cells. The link can be indirectly supported in our previous report that functional proteomics identifies enhanced expression of NF-kappaB-associated Wnt-1 production in human hepatocellular carcinoma tissues. This study aimed to further validate this link in human cells using anti-sense strategy. The effects of sequence-specific anti-sense morpholino oligonucleotides (ONs) targeting against pre-mRNA sequences of human p50 and p65 subunits of NF-kappaB as well as Wnt-1 genes were investigated. It revealed that all the three morpholino ONs inhibited NF-kappaB activation in human hepatoblastoma cell line HepG2 cells along with decreased Wnt-1 production. Chromatin immunoprecipitation assay ascertained the direct binding of NF-kappaB-p50 to the Wnt-1 promoter. Additionally, anti-P50 and anti-P65 morpholino ONs also repressed the phosphorylation of Ikappa Balpha which temporarily correlated with the inhibition of NF-kappaB activation accompanied by decreased Wnt-1 production by HepG2 cells. In summary, NF-kappaB activation is critically involved in the production of Wnt-1 by HepG2 cells. These results may have important oncology implications in treating patients with NF-kappaB-associated Wnt-1-producing cancers.
Journal of Biomedical Science 06/2008; 15(5):633-43. · 2.46 Impact Factor
[show abstract][hide abstract] ABSTRACT: Our aim was to examine whether certain molecular markers, specifically p53, p21, p27, and Bcl-2, could be used to predict the tumor response of rectal cancer to neoadjuvant therapy and determine the overall and disease-free survival rates of patients following neoadjuvant therapy. Seventy-seven patients with rectal cancers were used in this study. All of them received neoadjuvant therapy and 53 of them were given radical surgery. Immunohistochemical tests were performed for the four markers mentioned above using biopsy specimens obtained from 70 of the patients prior to radiation. The identical tests were performed for the same markers using excised specimens from the patients after radical surgery. For the pre-radiation specimens, the positive rate for having p27 and Bcl-2 markers was 32.7% and 16.6%, respectively. This rate increased to 73.5% and 41.6% (p=0.001 and 0.012, respectively) in the specimens obtained after the surgery. With respect to "fair response (FR)" of patients, the pre-radiation biopsy specimens showed significant difference for the p53 (-) and p27 (+) markers (p=0.006). Patients with a 3-year overall survival rate were found to have, from their surgical specimens, 92% of the p27 (+) and 75% of p27 (-) markers (p=0.0058). Our study showed: first, the rate of positive identification of molecular markers, p27 and Bcl-2, increased following neoadjuvant therapy. Second, either the p53 (-) or p27 (+) status was a good predictor for FR in the pre-radiation biopsy specimens. Third, patients with p27 (+) markers in the surgical specimens lived longer at 3 years.
[show abstract][hide abstract] ABSTRACT: Gasless laparoscopy using abdominal wall lifting (AWL) has been developed in an attempt to avoid the adverse effects of carbon dioxide pneumoperitoneum that may occur in conventional laparoscopy. However, lifting has been criticized for its poor operative space and surgical invasiveness. This study compared the AWL method with conventional CO2 pneumoperitoneum for laparoscopic cholecystectomy with respect to operation performance, postoperative course, and stress response.
During a 6-month period, 95 patients with symptomatic gallstones were randomly assigned to receive laparoscopic cholecystectomy with conventional CO2 pneumoperitoneum (CO2 group; N = 47) or the AWL method (AWL group; N = 48). Operative results and operative time were recorded. Cardiopulmonary functions were assessed, and arterial blood gases were analyzed during surgery. Urinary cortisol, vanillylmandelic acid, metanephrines, and nitrogen loss; serum complement 3, C-reactive protein, and interleukin-6; postoperative pain; and the presence of nausea and vomiting were assessed for 48 hours after surgery. Postoperative time to recovery of flatus, tolerance of a full oral diet, and full activity were also determined.
Only three significant differences were found. First, intraoperative ventilatory function deteriorated significantly less in the AWL group. Second, arterial blood gas determinations and capnography showed a greater decrease in intraoperative arterial pH and compliance with CO2 retention and an increase in peak airway pressure in the CO2 group (P < 0.05), reflecting poorer ventilatory performance. Third, preparation time and total operating time were significantly greater with the AWL method (P < 0.05).
Although AWL required a longer operation time, our results suggest that the technique may still have value in high-risk patients with cardiorespiratory diseases.