Biomedical subjects

S Hellström

Publications and source records attributed to S Hellström.

At least 19 recordsLinked to original sources

PubMed2004

The stromal reaction in basal cell carcinomas. A prerequisite for tumour progression and treatment strategy.

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 activity of the BCC tumours was evaluated with immunohistological techniques. In superficial BCC the tumour islands displayed moderate hyaluronan (HA) staining. Feeble proliferation, denoted by modest mitotic activity and weak Ki-67 and PCNA immunoreactivity, occurred within the tumour islands. The surrounding connective tissue resembled normal skin, and no differentiated tumour stroma was observed. In nodular BCC, the HA staining of the tumour strands was weak to moderate, denoting increased proliferative activity. The differentiated surrounding tumour stroma stained strongly for HA. Tumour islands of infiltrative BCC stained weakly to moderately to HA and evidenced intense proliferation. The intensely HA-stained tumour stroma ended abruptly and the adjacent areas were almost devoid of HA. This study showed that the proliferative activity of BCC cells is associated with increased expression of HA in the tumour stroma. Modification of tumour-associated connective tissue indicates a close relationship between the tumour cells and the adjacent matrix. In particular, in infiltrative BCC, such alterations include degeneration and possible modification and remodelling of the surrounding extracellular matrix. These processes involving areas of probable importance for tumour progression, should be considered when deciding the extent of intended surgical resection.

Basal Cell Carcinoma↗

PubMed2001

[Check ups after acute otitis media should be revised. What are we looking for and why?].

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 years of age by otoscopy but only 66 percent checked the mobility of the tympanic membrane. The follow-up procedure varied considerably. In a study of 129 ears (99 children) three months after an episode of AOM the diagnostic accuracy of pneumatic otoscopy, tympanometry and audiometry performed at a health care center was studied. The tympanometry performed by a nursing assistant had a very high sensitivity (93 percent) regarding secretory otitis media and could be used as a check-up after AOM. Thus there seems to be no need for the GP to examine ears where tympanometry is normal, but concentrate on the cases with pathologic tympanometry.

Acoustic Impedance Tests↗

PubMed2001

[Telemedicine in sparsely populated areas yields satisfied patients and better competence].

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 (surgery, medicine and gynecology). Among the 169, 47 cases were successfully managed via telemedicine. 30% of consultations were made in order to secure a second opinion. The remaining 70% were made in order to seek advice concerning a possible referral. At the telemedical visit, patients indicated a satisfaction score of 5.5 on a scale up to 6.0. The GP's rated the educational value at 4.4. After completion of the pilot-project, a survey of acceptance and ratings of the future potential of telemedicine for the health care system was carried out among 191 doctors and other health care workers in Västerbotten county. Using a similar graded scale up to 6.0, physicians rated telemedicine as regards utility for patients and quality of care at 4.6 and 4.5 respectively, somewhat higher than they rated the consequences of telemedical consulting for their working conditions and health care organizations, at 3.8 and 4.1 respectively. Despite a low volume of patients in the pilot project, we can conclude that telemedical consultations seem to reduce the number of referrals and raise the level of competency of the GP's. It's important to find further fields of application, as well as further ways of working and organizing the communication network in order to increase volume.

Clinical Competence↗

PubMed2001

A topical steroid without an antibiotic cures external otitis efficiently: a study in an animal model.

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 and polymyxin B added; Group D, the controls, treated with saline. All rats were observed otomicroscopically daily during the first 7 days after treatment and then on days 10 and 20. A standardized scoring system was used to evaluate colour, swelling and effusion of the ear canal. Histological specimens were collected on days 3, 7, 10 and 20. The most rapid improvement in the ear canal status occurred in the animals treated with betamethasone dipropionate. The inflammatory reaction of the ear canal skin caused by mechanical stimulation was characterized by oedema of the stroma but few inflammatory cells were present. The surface of the epithelium towards the connective tissue layer was smooth in the group III-treated animals (group A) whereas other groups had irregularities of the basal membrane. From this study it is inferred that the group III steroid betamethasone dipropionate alone heals experimentally induced external otitis more rapidly than hydrocortisone with oxytetracycline, with or without polymyxin B. These findings should be considered in future clinical trials of external otitis.

Administration, Topical↗

PubMed2001

How can the hooded seal dive to a depth of 1000 m without rupturing its tympanic membrane? A morphological and functional study.

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 membrane (TM) and middle ear (ME). We dissected and photodocumented the temporal bones of five newborn and three adult hooded seals in order to study the temporal bone structure and reveal its protective mechanisms for extreme pressure changes. Specimens were sectioned and stained for light microscopy. The thicknesses of the pars tensa and pars flaccida were found to average 60 and 180 microm, respectively. The ME cavity hosts a cavernous tissue of thin-walled vessels beneath the modified respiratory epithelium. The ME and external ear canal (EAC) volumes can be altered appreciably by filling/emptying the cavernous tissue with blood. The ossicles were fixed by contracting the tensor tympani and stapedius muscles simultaneously with complete occlusion of the EAC. According to Boyle's law, the volume of the gas-filled ME cavity at a depth of 1000 m is only 1% of its volume at the surface of the sea. Ascent from such a depth allows the gas in the ME cavity to expand, causing the TM to bulge laterally. This movement is counteracted by a reduction in the blood volume inside the cavernous sinuses, action in the tensor tympani and stapedius muscles and discharge of gas through the Eustachian tube. The presence of a firm, broad-based exostosis in the floor of the EAC lateral to the TM helps to obstruct the EAC.

Animals↗

PubMed2001

Degranulation of mast cells provokes a massive inflammatory reaction in the tympanic membrane.

OBJECTIVE: 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. STUDY DESIGN: In vivo, murine model. METHODS: In a rat model, the mast cell secretagogue compound 48/80 was applied locally to the tympanic membrane on 4 consecutive days and the ensuing inflammatory changes were evaluated by otological, light, and electron microscopy 3, 6, 9, 12, 18, 24, 36, and 48 hours and 4, 6, and 8 days later. RESULTS: Degranulation of the mast cells occurred within 3 hours of applying compound 48/80. Release of the mast cell substances coincided with an inflammatory event characterized by a two-stage reaction: an edema stage, peaking 6 hours after application, followed by a massive invasion of inflammatory cells, peaking at 24 and 48 hours. Pars flaccida and pars tensa were both involved, pars flaccida showing the earliest changes. Pars tensa exhibited the same biphasic reaction as pars flaccida, but approximately 6 hours later. CONCLUSIONS: The mast cells of the pars flaccida have the capacity to elicit an intense inflammation of the tympanic membrane. The biphasic reaction pattern resembles that observed in experimental otitis media, suggesting involvement of the mast cells in this inflammatory condition of the middle ear.

Animals↗

PubMed2000

Inhibition of OM pathogens by alpha-hemolytic streptococci from healthy children, children with SOM and children with rAOM.

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 recovered from the tubal orifice in each child. The samples were taken from 20 healthy children under general anesthesia, from 19 children with SOM and 20 children with rAOM. The method used to test the bacterial interference in vitro was a modified agar overlay method. The AHS sampled from the tubal orifice of the healthy children were able to inhibit 92% of the S. peumoniae isolates, 74% of the non-typable H. influenzae isolates and 89% of the M. catarrhalis isolates. The corresponding figures for children with SOM and children with rAOM were: 73% of the S. pneumoniae isolates, 58 and 54% of the non-typable H. influenzae isolates and 86 and 89% of the M. catarrhalis isolates. The AHS from children with SOM and children with rAOM were significantly less capable of inhibiting the S. peumoniae and the H. influenzae isolates (P<0.001). There was no significant difference between the three groups of children regarding inhibitory activity against M. catarrhalis. The results suggest that the inhibitory activity of the normal bacterial flora at the tubal orifice against pneumococci and H. influenzae may be reduced in children with SOM and rAOM.

Acute Disease↗

PubMed2000

Variability of Eustachian tube function in children with secretory otitis media. Evaluations at tube insertion and at follow-up.

OBJECTIVE: Despite the variable clinical course of diseases related to Eustachian tube function, the variability of tubal function has been less focused than outcomes of single tests. This study aimed to compare the passive and active tubal function and its variability in children with secretory otitis media (SOM) at tube insertion and at follow-up. METHOD: Thirty-eight ears in 19 children aged 4-10 years (mean 7.0 years) with long-standing SOM were examined 4-6 h after tube insertion, at 4 months and at 9 months. The pressure in the middle ear and the nasopharynx were recorded while performing (1) forced opening test, (2) equalization of +100 and -100 daPa, (3) Valsalva test, and (4) sniff test. The procedure was repeated after 30 min. Relationships were analyzed by uni- and multi-variate analysis of variance. RESULTS: From tube insertion to 4 months, the mean forced opening pressure increased from 282+/-128 to 355+/-153 daPa (P<0.01), and the mean closing pressure from 91+/-51 to 126+/-82 daPa (P<0.01). There was no further change at 9 months. Female gender, serous effusion (in contrast to mucoid), and more than three previous episodes of acute otitis media were related to higher opening and closing pressures. At tube insertion, 60% and 16% equalized +100 and -100 daPa, respectively, and 28% succeeded in performing Valsalva inflation. The sniff test was positive in 32%, indicating a closing failure. These rates did not change significantly over time. For individual ears, outcomes of all tests varied considerably when retested after 30 min; P(o) changed by +/-12% and P(c) by +/-26%, and 9-29% of the ears changed from a positive to negative response, or vice versa, in the equalization, Valsalva, and sniff tests. CONCLUSIONS: The unexpected finding of weaker closing forces at the day of tube insertion and increased tubal resistance at follow-up might be ascribed to changes in the muco-adhesive forces related to the disease and tube treatment. The pronounced intra-individual variability of test outcomes indicates that tubal function is dynamic and variable in ears prone to SOM, which emphasizes that results of single tubal function tests have very low prognostic value.

Analysis of Variance↗

PubMed2000

Exostoses and cavernous venous formation in the external auditory canal of the hooded seal as a functional physiological organ.

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 were prepared for light microscopic evaluation after staining with haematoxylin-eosin or toluidine blue. All EACs exhibited a firm, broad-based. mountain peak-shaped exostosis on the floor of the meatus, lateral to the eardrum. In addition, the meatal skin of the bony EAC harboured large venous sinuses. The exostosis and venous sinuses of the seal EAC participate in the protection of the sensitive hearing apparatus, particularly the pars tensa portion of the drum, during divine.

Animals↗

PubMed2000

Eustachian tube function varies over time in children with secretory otitis media.

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 comprised 42 ears in 21 children (13 males and 8 females) with tympanostomy tubes due to SOM. The middle ear pressure was recorded during repeated passive forced openings, equalization of + 100 daPa and - 100 daPa by swallowing, Valsalva inflation and forceful sniffing. Test sessions were performed twice (separated by 30 min) on each of 2 days, with a mean interval of 3.7 months in between. In the forced opening test there was a considerable intra-individual variability over time. Expressed as SD of the mean, the variability of the forced opening and closing pressures in individual ears was on average 15% and 23%, respectively, between sessions and 20% and 30% respectively, between test days. In the equalization, Valsalva and sniff tests the rates of responses that changed from positive to negative between sessions and test days ranged from 12% to 33%. Female gender and retraction pockets were related to poorer opening function in the forced opening test. Ears with serous effusion (in contrast to mucoid) showed a similar trend and also a lower occurrence of positive equalization, Valsalva and sniff tests. It was concluded that Eustachian tube opening and closing functions are highly variable in ears with SOM. Consequently, single tubal function tests have low value when used as a prognostic tool in individual ears.

Analysis of Variance↗

PubMed2000

Reliability and validity of a Swedish version of the Revised Leeds Disability Questionnaire for patients with ankylosing spondylitis.

The aim of the study was to investigate the reliability and the validity of a Swedish version of the Revised Leeds Disability Questionnaire (RLDQ). Forty-two patients, 36 men and 6 women, median age 52.5 years, median symptom duration 24 years, with spondylarthropathy were assessed with the RLDQ, three questions on the content of the questionnaire, and range-of-motion measures. The results indicated satisfactory test-retest stability and internal consistency, and only minor internal redundancy. RLDQ items were generally considered relevant and suggested additions were similar to items already included in the questionnaire. Patients with low disability scores tended to be older and have better joint mobility than those with higher scores. Physiotherapists observed and scored disability significantly higher than patients. Correlations between subscores of the RLDQ and range-of-motion measures were in the main weak. In conclusion the Swedish version of the RLDQ may be considered as reliable and valid.

Adult↗

PubMed2000

Variability of Eustachian tube function: comparison of ears with retraction disease and normal middle ears.

OBJECTIVE: To explore the short-term and longterm variability of tubal opening and closing in ears with advanced retractions and in healthy ears. STUDY DESIGN/METHODS: Twenty ears with retraction type middle ear disease (R-MED) and 20 normal ears underwent direct recording of the middle ear pressure during repeated forced openings, equalization of +100 daPa and -100 daPa by swallowing, Valsalva inflation, and forceful sniffing. Tests were performed twice (separated by 30 min) on each of 2 days separated by 3 to 4 months. RESULTS: There was considerable intraindividual variability of the forced opening pressure and the closing pressure in both groups, within as well as between sessions and test days. Although the variability was 1.5 to 2 times higher in ears with retraction than in the normal group, mean Po and Pc did not differ between the groups. Compared with normal ears, ears with retraction changed more frequently from a positive to negative test response, or vice versa, when re-tested after 30 minutes. Rates of positive response in the equalization and Valsalva tests were significantly lower in diseased ears compared with normal ears. CONCLUSIONS: Eustachian tube opening and closing functions vary more in ears with retraction disease than in normal ears, which is consistent with the variable clinical course of R-MED and implies that single tubal function tests have little prognostic value on the individual level.

Adolescent↗

PubMed2000

Human uvula: characterization of resident leukocytes and local cytokine production.

Upper airway infections often lead to macroscopic changes in the architecture of the uvula. Using immunomorphometric analysis, we investigated the frequency and distribution of immune cells and of cytokine-producing cells in uvular samples. Tissue macrophages, alphabeta T cells, gammadelta T cells, and B cells were, in declining order, the main cell populations. Gammadelta T cells and B cells exhibited reciprocal localization, with almost all gammadelta T cells residing in the vicinity of the epithelium, and all B cells in the glandular area. The presence of cells expressing the suppressor phenotype CD8+CD28- alphabeta T cells is suggested. Fifteen to twenty-five percent of the immune cells expressed the down-regulatory cytokine tumor growth factor beta. Most macrophages were located subepithelially, in the vicinity of the basal lamina. The composition and cytokine profile of leukocytes in the tissue suggest that the uvula may be a site, additional to the jejunal mucosa, for induction of mucosal tolerance to inhaled and ingested antigens. Concomitantly, the uvula appears to be protected from invasion of microbial pathogens by a subepithelial barrier of macrophages and gammadelta T cells.

Adult↗

PubMed2000

Treatment with dexamethasone arrests the development of myringosclerosis after myringotomy.

HYPOTHESIS: To attempt to inhibit the development of myringosclerosis by intraperitoneal injection of dexamethasone. BACKGROUND: 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. METHODS: Three groups of bilaterally myringotomized rats were treated at 12-hour intervals with intraperitoneal injection of dexamethasone, RU486 (a glucocorticoid receptor antagonist), and saline, respectively. At 6, 12, 24, and 48 hours after the myringotomy, 2 animals were anesthetized on each occasion and examined otomicroscopically. The animals were then killed, and the tympanic membranes were excised and prepared for light microscopic studies. RESULTS: Dexamethasone treatment retarded and diminished the development of sclerotic lesions markedly. Moreover, no inflammatory signs were seen in the flaccida specimens. When the RU486-treated animals were compared with the animals in the control group, there were no evident differences concerning the development of myringosclerosis or the extent of the inflammatory reaction. CONCLUSION: These findings confirm the earlier hypothesis that an inflammatory reaction in collagen tissue is involved in the mechanism that causes the development of myringosclerosis.

Animals↗

PubMed1999

The character and consequences of disturbing sound sensations in retraction type middle ear disease.

OBJECTIVE: Transient sound disturbances are common but neglected symptoms in retraction type middle ear disease (R-MED). The aim of this study was to explore and describe their character, their individual consequences, and their role in the development of tympanic membrane retractions. METHODS: Fifty-three subjects with manifest retractions and experiences of disturbing sound and ear sensations were interviewed. A qualitative method was used for analysis of the transcribed interviews. RESULTS: Two different patterns emerged from the interviews. 1. Too weak sound was the least common and most tolerable disturbance. It occurred in 45% and was eliminated by Valsalva's inflation. 2. Sudden and transient sensations of too loud and piercing sound, and intermittent autophony frequently caused intense and intolerable discomfort, which might in turn cause loss of control of speech and conversation. These types occurred in 74% and 60%, respectively, and were eliminated by evacuating the middle ear, for example by sniffing. Subjects who described too loud sound or intermittent autophony commonly preferred a retracted tympanic membrane position. This may explain why pressure equalization by swallowing, and inflation by Valsalva's manoeuvre often elicited discomfort. CONCLUSIONS: Transient experiences of too loud sound or intermittent autophony may indicate a shift of sound preference towards the sound experienced at negative middle ear pressure, and an unreliable tubal function in the sense that it fails to stay closed to protect the ear from sounds and pressure variations in the nasopharynx. Such experiences of altered sound may trigger evacuation of the middle ear, which eliminates the sound disturbance. It is crucial to identify, interpret, and explain the disturbances correctly in the therapy and prevention of retractions, since habitual evacuation exposes the tympanic membrane to strong negative pressure loads and a subsequent risk of developing retraction.

Adult↗

PubMed1999

Structure of the human uvula.

Eleven uvular biopsies were investigated for their morphology, the presence of mast cells and the distribution of hyaluronan and its major ligand CD44. Three microanatomical sites--surface epithelium, subepithelial area and area of glands--were examined. The oral side of the uvula was covered by a 15-20 cell thick layer of keratinized/parakeratinized surface epithelium, firmly anchored to the underlying connective tissue by connective tissue papillae. The width of the intercellular spaces in the epithelium increased toward the basal lamina, a location that exhibited intense hyaluronan and anti-CD44 staining. Most mast cells were located in the vicinity of blood vessels, at which sites there was high staining intensity of hyaluronan. Tissue mast cells could also be observed in the connective tissue septa enclosing the acini. Glands and muscle fibres became more sparse from the proximal part of the uvula to the distal end, while the amount of connective tissue increased. The localization and architecture of connective tissue elements and mast cells are consistent with the ability of the uvula to resist mechanical stresses and to develop oedema and fibrosis, respectively.

Adult↗

PubMed1999

Tele-otolaryngology consultations between two rural primary-care centres in southern Lapland and the University Hospital of Umeå.

In 1996 a telemedicine link was established between two primary-care centres of Västerbotten county and the University Hospital. Specialties involved at the University Hospital were otoloaryngology, orthopaedics and dermatology. Videoconferencing used ISDN at 384 kbit/s. The primary-care centres were equipped with video-endoscopes. During the first 21 months, there were 32 otolaryngology consultation. The average time for each consultation was between 15 and 30 min. Patients, general practitioners and specialists were interviewed using questionnaires with answers on a six-point scale, in which a score of six was best. Patient satisfaction produced a mean score of 5.7. The specialist doctors rated the video-consultation satisfactory for diagnosis. Roughly 40% of the referrals could be avoided by telemedicine. The general practitioners rated the educational effect of the consultation very highly.

Health Care Costs↗

PubMed1999

Moraxella catarrhalis-induced purulent otitis media in the rat middle ear. Structure, protection, and serum antibodies.

To study the effects of viable and heat-killed Moraxella catarrhalis bacteria on the middle ear mucosa and to evaluate the protection after whole-cell immunizations, Sprague-Dawley rats were challenged and rechallenged with four different M. catarrhalis strains. The animals were monitored by clinical observations, bacterial and histological samples from middle ears, and serum IgG levels. Only viable bacteria at a high concentration induced purulent otitis media, which was culture positive in 58% of the cases on day 4. The infection was characterized by a mild acute reaction lasting otomicroscopically about 8 days, together with quantitative and qualitative changes of the goblet cells. Structurally the mucosal effects of the heat-killed bacteria were less pronounced in the early phase compared to the viable bacteria, but similar at the end of the experiment at 6 months. The intrabullar and subcutaneous immunizations evoked an IgG antibody response in all animals, and the protection rate after immunization was 50% or more. The induced protection was not strain-specific. The study showed the rat to be a possible alternative for the study of different aspects of M. catarrhalis otitis media, an infection that is clinically and structurally different from that elicited by Streptococcus pneumoniae and Haemophilus influenzae in the rat.

Animals↗