Sten Hellström

Sten Hellström
Karolinska Institutet | KI · Department of Clinical Science, Intervention and Technology/Otorhinolaryngology/Audiology and Neurotology

MD, PhD

About

305
Publications
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6,053
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Additional affiliations
January 2014 - December 2015
Karolinska Institutet
Position
  • Professor (Full)
January 2014 - December 2015
Karolinska Institutet
Position
  • Professor (Full)

Publications

Publications (305)
Article
Background Universal newborn hearing screening (UNHS) contributes to the early diagnosis of hearing loss. However, not all permanent pediatric hearing impairments can be identified by UNHS. Aims/objective To investigate children who have successfully passed the UNHS, but have later-onset hearing loss at an early stage. Methods UNHS of children, w...
Article
Objective: To evaluate the efficacy of systemic and intratympanic steroid treatment in patients with idiopathic sudden sensorineural hearing loss (ISSNHL). Methods: Ninety patients who met the inclusion criteria were randomly divided into 3 groups (n = 30 per group). Group I patients were given oral methylprednisolone (MEPD) tablets, group II re...
Article
Objective: To survey long-term hearing outcomes and middle ear pathology in a 30-year follow-up in individuals with onset of recurrent acute otitis media (rAOM) before three years of age. Methods: 28 adults, aged 30.1–31.8 years, who originally – at the age of 12–32 months – participated in a study on rAOM between 1979 and 1983, were re-examined re...
Article
Full-text available
Background: The prevalence of sudden sensorineural hearing loss in children (CSSNHL) is consistently increasing. However, the pathology and prognosis of CSSNHL are still poorly understood. This retrospective study evaluated clinical characteristics and possible associated factors of CSSNHL. Methods: One hundred and thirty-six CSSNHL patients treate...
Article
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Objective: To evaluate the efficacy and safety of intratympanic and systemic steroid therapies in the initial treatment of Sudden Sensorineural Hearing Loss (SSNHL) patients. Methods: A comprehensive search of PubMed, Wanfang database and CNKI (China National Knowledge Infrastructure) was performed covering the period from January 1990 to July 2...
Article
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Background: Otitis media is one of the most common childhood diseases worldwide, but because of lack of doctors and health personnel in developing countries it is often misdiagnosed or not diagnosed at all. This may lead to serious, and life-threatening complications. There is, thus a need for an automated computer based image-analyzing system that...
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Full-text available
Otosclerosis is a common disorder that leads to conductive hearing loss. Most patients with otosclerosis also have tinnitus, and surgical treatment is known to improve hearing as well as tinnitus. Some patients however experience worsening of tinnitus after the operation, but there are no known factors that allow surgeons to predict who will be at...
Article
These findings suggest that Atrial natriuretic peptide (ANP) exhibits an inhibitory effect on auditory brainstem response (ABR) and is involved in the neuromodulation of the auditory nervous system. ANP may alter electrophysiological properties of the cochlea and play a role in auditory action. This study was undertaken to examine and clarify the r...
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Full-text available
Otosclerosis is a disorder that impairs middle ear function, leading to conductive hearing loss. Surgical treatment results in large improvement of hearing at low sound frequencies, but high-frequency hearing often suffers. A likely reason for this is that inner ear sensory cells are damaged by surgical trauma and loud sounds generated during the o...
Article
Scar tissues were collected from patients with keloids, hypertrophic scars and mature scars. Normal skin was obtained from healthy individuals. Clinical attributes were used to select which tissue to obtain but the distribution of the specific hyaluronan (HA) staining was then used for the definite classification of the various scar types. Light mi...
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Most tympanic membrane (TM) perforations heal spontaneously, but approximately 10-20% remain open as chronic TM perforations. Chronic perforations can lead to an impaired hearing ability and recurrent middle ear infections. Traditionally, these perforations must be surgically closed, which is costly and time consuming. Therefore, there is a need fo...
Article
Type II collagen is synthesized in the tympanic membrane during healing of a perforation. The time course and appearance of Type II collagen regrowth in the newly healed tympanic membrane is the subject of the present study. The arrangement of Type II collagen fibers in the tympanic membrane gives it a unique tensile strength important for sound co...
Article
Full-text available
Background and objectives: Although serious complications of otitis media (OM) such as brain abscess are rare, sequelae of OM such as tympanic membrane perforation and atelectatic tympanic membrane are quite common. Inner ear sequelae can cause hearing loss and speech and language problems. The objectives of this article are to provide a state-of-...
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Full-text available
Background and objectives: The pathogenesis of otitis media (OM) involves a number of factors related to the anatomy, pathology, and cell biology of the middle ear, the mastoid, the Eustachian tube, and the nasopharynx. Although some issues of pathogenesis are fairly well established, others are only marginally indicated by current knowledge, and...
Article
Background: Grading of acute otitis media (AOM) is important in clinical situations as well as in research. Current grading scales for AOM have used a 6 to 9 point scoring system primarily based on variation of redness and bulging of the tympanic membrane (TM). This study aimed to develop and validate a new scale for grading AOM. Method: The sca...
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Full-text available
Mice deficient in plasminogen, the precursor of plasmin, show completely arrested healing of tympanic membrane (TM) perforations, indicating that plasmin plays an essential role in TM healing. The activation of plasminogen to plasmin is performed by two plasminogen activators (PAs), urokinase-type PA (uPA) and tissue-type PA (tPA). To elucidate the...
Article
The aim of this study was to investigate the role of congenital cytomegalovirus (CMV) infection as a cause of various types of sensorineural hearing loss (SNHL) in a group of nonsyndromic children with otherwise unknown aetiology of hearing loss. Furthermore, the occurrence of combined congenital CMV infection and connexin 26 (Cx26) mutations was i...
Article
We sought to identify the prevalence of otitis media with effusion (OME) in urban Chinese children in Xi'an, China. Five kindergartens and 3 primary schools were randomly selected in the urban area of Xi'an. Screening otoscopic and tympanometric examinations were performed on 2,902 children (1,491 boys and 1,411 girls) 2 to 8 years of age. Children...
Article
SUMMARYA simple anti-roll plate has been designed for use in preparing ‘dry’ ultrathin frozen sections. The plate, which is made of a strip of a glass cover slip and attached close to the edge of a glass knife, prevents curling of the sections.
Article
The aim of this review was to study the effectiveness of ventilation tube (VT) treatment in children with secretory otitis media (SOM), assessed by improved hearing, normalized language and quality of life (QoL), and recurrent acute otitis media (rAOM), assessed by number of episodes of AOM and QoL. Data Sources. Cochrane Library, PubMed, and Embas...
Article
In order to examine whether a myringotomy made with a CO2-laser might be alternative to a ventilation tube, a perforation was made in the upper rear quadrant bilaterally, of 22 rats. The laser-made perforations showed a delayed healing pattern, about twice the closing time of a similar-sized perforation made with a myringotomy lancet. Serous effusi...
Article
Absorbable gelatin sponge (Gelfoam)—commonly used in otosurgery—was gently inserted or firmly packed into the middle ear cavities of rats. The postoperative changes were evaluated 2 to 3 months later when, apart from some air-filled canals leading from the tym-panal orifice of the Eustachian tube towards the attic, the middle ear cavity had become...
Article
It is known that the healing of a perforated tympanic membrane can be influenced by mechanical procedures as well as drugs. Animal experiments have recently shown that local treatment with steroids delays the healing of a tympanic membrane perforation, whereas hyaluronan (hyaluronic acid) improves the healing rate as well as the quality of the scar...
Article
A baby boy presented with a double tongue combined with a median cleft palate. He was otherwise normally developed. The double tongue was reconstructed to form one tongue 40 days after birth. At follow-up examination when he was 6 months old the tongue was well formed with normal function.
Article
A micro-organ composed of islands resembling carotid body cells located in the endoneural space of the rat recurrent laryngeal nerve is described. The microglomus is located 5 to 6 mm from the nerve entrance into the laryngeal wall. The characteristic cells, containing numerous membrane-bound granules, or dense-cored vesicles, are surrounded by bun...
Article
The development of myringosclerosis has been correlated with increased production of oxygen-derived free radicals. For the present study, we used a null mutant mouse lacking extracellular superoxide dismutase to test the hypothesis that increased production of free radicals can cause the development of myringosclerosis. Null mutant mice and wild-ty...
Article
Full-text available
The results of the present study show that the early inflammatory response in plasminogen (plg)-deficient mice is not altered compared to that in wild-type (wt) mice. Therefore the chronicity of the perforation in the long-term healing experiment cannot be explained by an impairment of the early inflammatory response, but rather by an impairment in...
Article
Among the three main gentamicin (GM) compounds following intratympanic application, the cochleotoxicity of C2 was the most severe, whereas that of C1a was the weakest. Understanding of the different cochleotoxicity characteristics of each compound may be of use in future custom-made intratympanic therapy for Ménière's disease. To investigate differ...
Article
To evaluate digital imaging of the tympanic membrane by telemedicine technology and study interpersonal agreement in assessing image quality. In an open consecutive study, 64 children aged 2-16 years who attended three rural health care centres in Northern Sweden with otalgia were examined with video endoscopic photography of their tympanic membran...
Article
Inflammatory conditions of the ear, otitis media, are one of the most common disease entities in children. In this study, the role of the plasminogen (plg)/plasmin system for the spontaneous development of chronic otitis media was investigated by the analysis of plg-deficient mice. Whereas essentially all of the wild-type control mice kept a health...
Article
Plasminogen has been proposed to play an important role in different tissue remodeling processes such as wound healing and tissue regeneration after injuries. The healing of tympanic membrane perforations is a well-organized chain of inflammatory events, with an initial invasion of inflammatory cells followed by reparative and restoration phases. H...
Article
The present study was undertaken to compare the clinical benefits of prescribing ear drops containing 0.05% solution of betamethasone dipropionate (BD), and ear drops containing hydrocortisone with oxytetracycline hydrochloride and polymyxin B (HCPB), for topical treatment of external otitis. Fifty-one patients were enrolled in this open randomized...
Article
Irrespective of the microbial agent, group III steroid solution cured external otitis efficiently in a rat model. The addition of antibiotic components to steroid solutions for the treatment of external otitis is of questionable validity. External otitis, caused by infection with either Pseudomonas aeruginosa or Candida albicans, was established in...
Article
The CD44 receptor is a transmembrane glycoprotein expressed on a variety of cells like endothelial, epithelial and smooth muscle cells. This molecule has many important functions, e.g. in cell-cell and cell-matrix interactions and signal transduction. The main ligand for CD44 is hyaluronan (HYA). HYA is a glycosaminoglycan with structural and cell...
Article
Problem: The study investigated the early inflammatory changes in the TM in rat models of otitis media with effusion (OME), acute otitis media (AOM), and after degranulation of pars flaccida (PF) mast cells (MCs). Furthermore, we have developed a new model of AOM that resembles the natural route of infection in man.Methods: OME was initiated by blo...
Article
Specimens of basal cell carcinomas collected from 28 patients were classified into three groups: superficial, nodular, and infiltrative, according to their microarchitecture. The specimens were then subjected to histological characterization by means of a biotinylated hyaluronan-binding probe (HABP). By using Ki-67 and PCNA the proliferative activi...
Article
The rat is a frequently used animal model for middle ear research. To date, acute otitis media (AOM) has been evoked after instillation of bacteria directly into the middle ear cavity or after traumatizing the tympanic membrane. The purpose of the study was to examine whether, with an intact tympanic membrane and middle ear cavity, intranasally dep...
Article
Objective: The inhibitory effect of alpha-haemolytic Streptococci (AHS) in vitro on the three commonest otitis media pathogens, Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis, was previously investigated. The aim of this study was to determine the mechanism of this inhibitory activity. Material and methods/results: Wh...
Article
Objective-The inhibitory effect of alpha-haemolytic Streptococci (AHS) in vitro on the three commonest otitis media pathogens, Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis, was previously investigated. The aim of this study was to determine the mechanism of this inhibitory activity. Material and Methods/Results-When fr...
Article
The early inflammatory changes in the tympanic membrane were explored in 2 rat models. Acute otitis media was induced by instillation of Streptococcus pneumoniae type 3 into the middle ear cavity, and otitis media with effusion was induced by blockage of the eustachian tube. Otomicroscopic examination was performed before the rats were painlessly s...
Article
The present study aimed at elucidating whether there are blood vessels in the semitransparent portion of the tympanic membrane. The normal semitransparent portions of pars tensa show strikingly few, small-caliber vessels under the otomicroscope. The major portion of a pars tensa seems to be devoid of blood vessels. In inflammatory conditions of the...
Article
To identify and localize hyaluronan (HYA) and alpha-atrial natriuretic polypeptide (ANP) in human nasal polyps and to measure the HYA concentrations. Twelve nasal polyps were collected during routine polypectomies and processed histochemically and biochemically to determine the occurrence of HYA. The distribution of ANP was investigated using an im...
Article
The matrix components of the vessel wall are of great importance for the function of the vessel system of which both endurance and elasticity are prerequisites. One component of the vessel wall is the glycosaminoglycan hyaluronan (HYA) with its unique physico-chemical properties, e.g. viscoelasticity and barrier function. The present study aimed to...
Article
The matrix components of the vessel wall are of great importance for the function of the vessel system of which both endurance and elasticity are prerequisites. One component of the vessel wall is the glycosaminoglycan hyaluronan (HYA) with its unique physico-chemical properties, e.g. viscoelasticity and barrier function. The present study aimed to...
Article
We examined the adherence to pharyngeal cells of alpha-haemolytic Streptococci (AHS) and Haemophilus influenzae, representing normal flora and otitis media (OM) pathogens, respectively. The bacteria were incubated with epithelial cells brushed from the tonsils, adenoid or tubal orifice of children and adults. Adherence varied among the clinical iso...
Article
Acute otitis media is a major cause of visits to pediatric health care providers. Myringotomy in uncomplicated acute otitis media is debatable today. The study addressed this problem through the otomicroscopic and histopathological observations of the events occurring in the tympanic membrane during the first week after myringotomy. Randomized stud...
Article
Myringotomy (Myr) is one of the most frequently performed surgical procedures in children. However, events occurring in the early phases, i.e. a matter of hours, following Myr in the acute otitis media (AOM) model have not been described. The aim of the present study was to evaluate the early otomicroscopic and histopathologic reactions of the tymp...
Article
Full-text available
To understand better the pathogenesis of inner ear (IE) damage caused by otitis media (OM), the round window membrane(RWM) structure was investigated in a rat model for pneumococcal otitis media (POM). The RWM of 25 rats were evaluated light and electron microscopically on 1 day, 3 days, 6 days, 10 days, and 20 days after the unilateral inoculation...
Article
The aim of this study was to evaluate the development of myringosclerosis in in vitro-cultured tympanic membranes. Sprague-Dawley rats were myringotomized bilaterally and the tympanic membranes were excised after sacrifice. The explants were placed in inserts in wells filled with a nutrient medium. Every second day the tympanic membranes were photo...
Article
Full-text available
Glycosaminoglycans are important components of all extracellular matrices. One of the glycosaminoglycans is hyaluronan, which is ubiquitously distributed throughout the connective tissue. Hyaluronan is especially abundant in the skin, in which it is of both structural and functional importance. This study describes the localization and distribution...
Article
Previous studies have shown that children with recurrent acute otitis media (rAOM) have significantly lower quantities of alpha-haemolytic streptococci (AHS) in the nasopharynx than healthy children. Furthermore children with otitis media have AHS with lower inhibitory activity in vitro on Streptococcus pneumoniae and non-typable Haemophilus influe...
Article
Bacterial interference studied by means of agar methods has shown a decreased number of inhibitory alpha-haemolytic Streptococci among otitis-prone children. Additional information was gained regarding the interplay between alpha-haemolytic Streptococci (AHS) and otitis media (OM) pathogens by comparing the bacterial interference in broth with the...
Article
The latest Swedish consensus conference (May 2000) on treatment of acute otitis media (AOM) states that a check-up should be made three months after an episode of AOM. In order to find out how these recommendations are implemented 36 general practitioners were asked about their management of AOM check-ups. Almost all GPs checked children below 5 ye...
Article
Recent studies using a satellite-linked dive recorder have shown that the hooded seal (Cystophora cristata), a common Arctic pinniped, can dive to a depth of > 1000 m and stay submerged for close to 1 h. At these depths the water pressure reaches 100 atm, entailing obvious risk of serious damage to the hearing apparatus, mainly the tympanic membran...
Article
A telemedical pilot-project involving two rural primary health care centers in Tärnaby/Storuman in Southern Lappland and the University Hospital of Umeå was carried out during the period Sept. 1, 1996-Dec. 31, 1998. Out of 169 consultations in all, 40 pertained to dermatology, 50 to ENT, 40 to orthopedics, and a further 27 to other specialties (sur...
Article
In an animal external otitis model, inflammatory reactions were evoked by mechanical stimulation of the rat ear canal skin. The rats were in four groups: group A treated with a group III steroid, betamethasone dipropionate; group B treated with hydrocortisone combined with oxytetracycline; group C treated with hydrocortisone with oxytetracycline an...
Article
The pars flaccida is extremely rich in mast cells. On stimulation the mast cells release preformed and de novo synthesized inflammatory substances. The purpose of this study was to examine how these mast cell substances provoke inflammatory changes in the tympanic membrane. In vivo, murine model. In a rat model, the mast cell secretagogue compound...
Article
Myringosclerosis, a common finding after myringotomy, has been recently associated with an increased production of oxygen free radicals. Ascorbic acid's proposed actions include collagen synthesis, antioxidation, and free radical scavenging. The effects of topical ascorbic acid on healing tympanic membranes were studied. Particular attention was gi...
Article
The present study was undertaken to elucidate the inhibitory activity of the normal nasopharyngeal flora against the three most common otitis media (OM) pathogens in healthy children, children with secretory otitis media (SOM) and children with recurrent otitis media (rAOM). Isolates of alpha-hemolytic streptococci (AHS) and OM pathogens were recov...
Article
To attempt to inhibit the development of myringosclerosis by intraperitoneal injection of dexamethasone. The authors' earlier report showed that the development of myringosclerosis after myringotomy was associated with an inflammatory reaction. The present study was performed to secure evidence for this hypothesis. Three groups of bilaterally myrin...
Article
Exostoses of the external auditory canal (EAC) develop after protracted mechanical, chemical or thermal irritation in particular. This is a common disorder among aquatic sportsmen and has been considered unique to Man. We dissected and photodocumented the EACs of 5 newborn and 3 adult Hooded Seals (Cystophora cristata). Serial sections of the EACs...
Article
Impaired opening and closing functions of the Eustachian tube are considered to be pathogenic factors in secretory otitis media (SOM). As the clinical course of SOM is variable, the variability of tubal function is of interest. We aimed to explore the short- and long-term variability of tubal opening and closing functions in SOM. The study comprise...