Search PubMed⌕ Search

Biomedical subjects

H Gerber

Publications and source records attributed to H Gerber.

At least 55 records · Page 3Linked to original sources
PubMed1999

Three-dimensional video analysis of facial movements: a new method to assess the quantity and quality of the smile.

The results of neuromuscular reconstructions of the paralyzed face are difficult to assess. Very sophisticated methods are necessary to measure the motor deficits of facial paralysis or the functional recovery in the face. The aim of this development was a relatively simple system for data acquisition, which is easy to handle and which makes it relatively cheap to delegate data acquisition to centers all over the world, which will not be able to derive a data analysis on their own, but will send their data to a center with specialized equipment. A complex mirror system was developed to get three different views of the face at the same time on the video screen. At each investigation, a digital video is taken from a calibration grid and from standardized facial movements of the patient. Secondary analysis of the digital videofilm is made possible at any time later on by the support of a computer program, which calculates distances and movements three-dimensionally from the frontal image and the right and left mirror images. Pathologies of the mimic movements can be identified as well as improvements after surgical procedures by this system. The significant advantage is the possibility to watch the same movement on the video which is under study and to apply any kind of study later on. Taking the video needs only a few minutes, and fatigue of the patient's mimic system is prevented. Measurements usually at the endpoints of the movements give excellent information on the quantity of the movement or the degree of the facial palsy, whereas the video itself is very informative regarding the quality of the smile. Specific computer software was developed for standardized three-dimensional analysis of the video-documented facial movements and for data presentation. There are options like two-dimensional graphs of single moving points in the face or three-dimensional graphs of the movements of all measured points at the same time during a standardized facial movement. By a comparison of the right- and left-sided alterations of specific distances between two points during the facial movements, the degree of normal symmetry or pathologic asymmetry is quantified. This system is more suitable for detailed scientific multicenter studies than any other system previously established. A very sensitive instrument for exact evaluation of mimic function is now available.

Calibration↗
PubMed1999

Prevalence of beta2-toxigenic Clostridium perfringens in horses with intestinal disorders.

The incidence of a new, yet unassigned toxin type of Clostridium perfringens containing the genes for the alpha-toxin and the recently described beta2-toxin in horses with intestinal disorders is reported. The study included 18 horses suffering from typical typhlocolitis, 7 horses with atypical typhlocolitis, 16 horses with other intestinal disorders, and 58 horses without intestinal disease. In total, 20 samples of ingesta of the small and large intestines, five biopsy specimens of the intestinal wall, and 74 fecal samples were analyzed bacteriologically. C. perfringens isolates were typed for the presence of the alpha-, beta-, beta2-, and epsilon-toxin and enterotoxin genes by PCR, including a newly developed PCR for the detection of the beta2-toxin gene cpb2. beta2-Toxigenic C. perfringens was detected in samples from 13 of 25 (52%) horses with typical or atypical typhlocolitis, with a particularly high incidence in specimens of ingesta and biopsy specimens (75%), whereas only 6 of 16 specimens from horses with other intestinal diseases yielded beta2-toxigenic C. perfringens. No beta2-toxigenic C. perfringens was found in the samples from the 58 control horses, of which only one fecal sample contained C. perfringens type A. Among the samples from the 15 horses with fatal cases of typical and atypical typhlocolitis 9 (60%) were positive for beta2-toxigenic C. perfringens, whereas samples from only 4 of the 10 (40%) animals with nonfatal cases of infection were positive. We found an interesting correlation between the antibiotic-treated horses which were positive for beta2-toxigenic C. perfringens and lethal progression of the disease. No C. perfringens strains isolated in this study contained genes for the beta- and epsilon-toxins and enterotoxin. The high incidence of beta2-toxigenic C. perfringens in samples of ingesta, biopsy specimens of the intestinal wall, and feces from horses suffering or dying from typhlocolitis together with the absence of this organism in healthy horses provides strong evidence that beta2-toxigenic C. perfringens play an important role in the pathogenesis of typhlocolitis.

Animals↗
PubMed1999

Drug-induced linear IgA bullous dermatosis associated with ceftriaxone- and metronidazole-specific T cells.

BACKGROUND: Previous reports indicate that various drugs may induce linear IgA bullous dermatosis (LABD). The role of T cells and T-cell-derived cytokines in the pathomechanism of such skin lesions, however, has remained unclear. OBJECTIVE: To describe a case of LABD induced by ceftriaxone and metronidazole in an 80-year-old female suffering from cholelithiasis with concomitant cholecystitis and provide evidence that drug-specific T cells and their cytokines may contribute to the development of LABD lesions. METHODS: We performed flow cytometry analysis of peripheral blood T cells during LABD, epicutaneous testing (scratch-patch) and lymphocyte proliferation analysis (LTT) with the suspected drugs, routine histological and immunohistochemical examination of the acute skin lesions during LABD as well as of the positive epicutaneous test reactions and measurement of cytokines (IL-4, IL-5, IL-10, TNF-alpha, IFN-gamma) in the supernatant of the LTT cultures. RESULTS: An increased number mainly of activated CD8+ cells was detected in the peripheral blood during LABD. T cell sensitization to ceftriaxone and metronidazole was confirmed by epicutaneous testing and LTT, indicating that these methods may be useful in identifying the causative drugs. Enhanced cytokine levels, particularly of IL-5, were found in the supernatant of the LTT stimulated with ceftriaxone and metronidazole. Furthermore, in situ expression of IL-5 was confirmed in the patient's skin lesions by immunohistochemistry. CONCLUSION: Our findings suggest that in addition to IgA antibodies drug-specific T cells and their subsequent release of cytokines may play an important role in the pathogenesis of drug-induced LABD.

Aged↗
PubMed1999

Inhibition of iodine organification and regulation of follicular size in rat thyroid tissue in vitro.

The factors mediating the accumulation of thyroglobulin are of great importance to the understanding of the pathogenesis of human and experimentally induced colloid goiters. To elucidate further the underlying cellular mechanism, thyroid fragments from newborn rats were incorporated into semisolid alginate beads and were cultured as three-dimensional organoids for up to 21 d. In five parallel cultures, the medium contained either no supplements (group A), Nal (group B), thyroid-stimulating hormone (TSH) (group C), Nal plus TSH in the same concentrations as B and C (group D), or Nal and TSH (as in group D) plus methimazole (MMI, group E). The thyroid organoids maintained morphological integrity, functional activity, and ability to proliferate in vitro. Addition of iodine to the cultures significantly increased mean (+/-SEM) follicular diameters from 19.5 +/- 0.7 microm in controls to 33.9 +/- 2.2 microm (p < 0.0001) when NaI was added alone (group B), and 30.4 +/- 1.7 microm (p < 0.0001) when combined with TSH (group D). The effect of NaI on follicular size was abolished by MMI (group E, follicular diameter 23.5 +/- 1.3 microm). The results presented support the recent finding, using a rat colloid goiter model, that not only TSH but also iodine organification or its inhibition are important factors in modulating follicular morphology.

Animals↗
PubMed1999

Follicle-forming cat thyroid cell lines synthesizing extracellular matrix and basal membrane components: a new tool for the study of thyroidal morphogenesis.

Interactions between follicular epithelial cells and extracellular matrix (ECM) are supposed to play an important role in the development and maintenance of thyroid tissue architecture. In the present study we have therefore investigated the synthesis of ECM components by a feline thyroid cell line which is able to form follicle-like structures in vitro, and also in v-ras-transfected and control-transfected sublines. Transfections were performed by lipofection with pZSR (viral Harvey ras gene; neo) and pSV2-neo (control, neo only) plasmids. We have adapted a semisolid culture system composed exclusively of polymerized alginate and therefore devoid of ECM components. Feline cells embedded in alginate gels as single cells and cultured for up to 90 days formed cell clusters within 10 days. Follicle-like structures were formed in the original cell lines and also in the v-ras- and control-transfected cells. Differences in proliferation rates were observed, the v-ras-transfected cells growing up to two to three times faster than the non-transfected cells. Immunostaining was done using rabbit first antibodies directed against mouse collagen IV, human fibronectin, laminin (tumor Engelbreth-Holm-Swarm laminin), perlecan and other ECM components. For comparison, immunostaining was also performed on cryosections of nodular goiters of six hyperthyroid cats. The cell lines and their transfected clones stained strongly positive for collagen IV and fibronectin, and positively but less strongly for laminin and perlecan. The cat goiter tissue stained positively for collagen IV, laminin, perlecan, and fibronectin, and positive staining for S-laminin (containing the beta2-chain) was seen in blood vessel walls in this tissue. In conclusion, cat cell lines grow three-dimensionally in alginate beads over several weeks, they form follicle-like structures and express the same ECM components as the native cat goiter tissue. Transfection with v-ras does increase proliferation rate, but does not fundamentally alter formation of follicle-like structures and ECM expression. Alginate gel culture is a promising new tool for the study of follicular morphogenesis, polarity, the expression pattern of ECM components and of the interaction between thyrocytes and ECM. It avoids interference caused by gels composed of ECM components.

Alginates↗
PubMed1998

Equine sarcoids.

Sarcoids, the most common tumor of the horse, are fibroblastic, wart-like skin lesions that show variable manifestations. They are often invasive and recurrent, although they do not fulfill all criteria of malignancy. Due to their anatomic location, these tumors can sometimes cause loss of use of the horse. There is very strong evidence that sarcoids are caused by viruses closely related or identical to bovine papilloma viruses, and genetic studies have shown associations between genes in or near the equine major histocompatibility complex (MHC) and susceptibility to sarcoid. Several types of treatments have been successful in treating sarcoids, although the response to therapy is not consistent. Current treatment of sarcoids primarily involves antitumor therapy, but the development of preventative measures in the future may be directed against the causative papilloma virus. Sarcoid continues to be an important clinical entity for the equine practitioner.

Animals↗
PubMed1998

Anti-D immunoglobulin in Rh(D) negative volunteers: clearance of Rh(D) positive red cells and kinetics of serum anti-D levels.

Properties of a new anti-D immunoglobulin were assessed in Rh(D) negative healthy male adults. Six volunteers received intravenous, and five volunteers intramuscular injections of 200 micrograms anti-D, 48 hours after pre-treatment with 5 mL of Rh(D) positive erythrocytes. Immediately after intravenous administration of anti-D, a rapid decrease of the Rh(D) positive erythroyctes was noted. After intramuscular injection of anti-D, there was a lag phase of 6 hours until the erythrocytes decreased, and the elimination rate was slower. Twenty-four hours after injection of anti-D, the Rh(D) positive erythrocytes were at the detection limit or no longer detectable in all volunteers. After intravenous administration, anti-D serum levels decreased from 45 ng/mL at 2 hours to 29 ng/mL at 24 hours, whereas after intramuscular administration, anti-D became detectable at 4 hours and increased to 11 ng/mL at 24 hours. During subsequent months, anti-D serum levels decreased at similar rates in both groups. After six months, anti-D was not detectable in any of the volunteers. Thus, the new anti-D immunoglobulin induced elimination of the Rh(D) positive erythrocytes and suggested that Rh(D) immunization of the volunteers was prevented.

Adult↗
PubMed1998

Morphological, immunohistochemical and autoradiographic studies of thyroid autonomy.

The values and limits of morphological, immunohistochemical and autoradiographic methods in studies of thyroid autonomy are briefly discussed. For meaningful studies of molecular aspects of thyroid autonomy--such as for example TSH receptor and Gs-alpha gene mutations--it is absolutely crucial that the tissue analysed is well characterized and really is autonomous. This is particularly important in view of the well known heterogeneity of human goiter tissue in respect to many if not all functional and proliferative parameters. To prove functional and proliferative autonomy of thyroid tissue, autoradiography is a very helpful tool, while simple morphology and immunohistochemistry do not contribute substantially to this aim.

Animals↗
PubMed1998

[Insulin as an anabolic: hypoglycemia in the bodybuilding world].

Excessive body building may be dangerous. To promote athletic performance and to improve physical appearance many of the body builders abuse anabolic-androgenic steroids and other drugs. The abuse of insulin as an anabolic medication in this athletic community was followed by a case of severe hypoglycaemia in a body builder. A 30-year old male presented with cerebral symptoms of hypoglycaemia. Directly before an international competition he tried to stimulate muscle growth by using the hypoglycaemic stimulus to the growth hormone. To achieve this he injected 70 IE of a short-acting insulin subcutaneously, resulting in severe hypoglycaemia. After the initial administration of intravenous glucose by the paramedics, he lost consciousness and showed signs of convulsions. After orotracheal intubation by an emergency physician, despite of ongoing infusion of glucose the blood glucose concentration remained low as measured in the out-of-hospital setting. Finally administration of additional glucose and glucagon in the intensive care unit was able to stabilize the metabolic system. In any case of severe hypoglycaemia, repetitive measurements of blood glucose even in the prehospital setting should be performed to detect the hypoglycaemia especially if athletes are concerned.

Adult↗
PubMed1998

Alginate gel culture allows the retention of extracellular matrix and follicular structure of rat thyroid tissue but does not lead to the formation of follicles by FRTL-5 cells.

Extracellular matrix (ECM) and basement membrane (BM) components were studied by immunohistological methods in native rat thyroid tissue, and in rat thyroid tissue and FRTL-5 cells cultured in a three-dimensional alginate bead system. In all three situations, the presence of collagen IV, laminin, perlecan, and fibronectin was demonstrated. There were marked differences between rat thyroid tissue and FRTL-5 cells in culture. Rat thyroid tissue maintained a follicular structure, whereas FRTL-5 cells did not form follicles. Rat thyroid cells multiplied more slowly than FRTL-5 cells and thyroglobulin (Tg) was visible in the follicular lumen, while in FRTL-5 cells Tg was only seen intracellularly. Tg iodination was much lower in FRTL-5 cells than in rat cells. In rat thyroid cells, positive staining for collagen IV, laminin, and perlecan was seen in thin membranes around individual follicles, and for fibronectin around groups of follicles. In FRTL-5 cells, these ECM/BM components could be identified, but were not organized into equally regular networks around groups of cells. These results demonstrate that of the two types of cells examined, primary cultures of rat thyroid cells in alginate beads maintain structural and functional similarities to native thyroid tissue and would therefore be suitable for future in vitro studies of thyroidal ECM/BM and their interrelationship with growth and function of this organ. FRTL-5 cells cultured in alginate beads show some functional, but not structural similarities to native thyroid tissue and so would be less valuable for use in such studies.

Alginates↗
PubMed1998

Learning manual skills in anesthesiology: Is there a recommended number of cases for anesthetic procedures?

UNLABELLED: The learning process is a multidimensional function with a wide intra- and interindividual scattering. To determine the learning process in anesthesia, we evaluated 11 first-year residents according to their rate of success or failure when applying manual anesthesiological skills, such as performance of spinal, epidural, or brachial plexus anesthesia and tracheal intubation or insertion of an arterial line. Epidural anesthesia was the most difficult procedure (P < 0.05). Significant differences were found between epidural anesthesia and tracheal intubation (P < 0.05), insertion of an arterial line (P < 0.05), and brachial plexus block (P < 0.05), as well as between spinal anesthesia and orotracheal intubation (P < 0.05). Learning curves are a valid tool for monitoring institutional and individual success. IMPLICATIONS: To investigate the learning process in anesthesia, typical anesthetic procedures were performed by inexperienced residents during their first year. Learning curves were generated for each procedure performed. Epidural anesthesia was the most difficult procedure to perform (P < 0.05).

Anesthesia, Epidural↗
PubMed1998

Comparing the enzyme allergosorbens and coated allergen particle tests for latex allergy: which in vitro test should be chosen by an anesthesiologist?

UNLABELLED: To determine sensitivity and specificity of the enzyme allergosorbens test (EAST) and the coated allergen particle Test (CAP) in detecting specific antibodies against latex, we compared these two methods in a previously investigated sample of an epidemiological study among our anesthesia staff. One hundred one blood samples were tested with EAST and CAP for specific antibodies against latex. Skin test results were used as references. CAP was more sensitive in detecting sensitized individuals than EAST (56% vs 18.8%). Two additional persons with previously negative skin tests were detected. These results suggest that the EAST system is not as sensitive as the CAP system. Therefore, the CAP system should be preferred for the in vitro diagnosis of latex allergy. IMPLICATIONS: Testing for latex allergy requires time-consuming and technically difficult tests. Easy to perform in vitro tests for latex allergy are desirable. Our results indicate that the coated allergen particle test is more sensitive and easy to use than the enzyme allergosorbens test.

Anesthesiology↗
PubMed1998

Techniques and equipment for muscle mechanics.

The individual in vivo mechanical properties of muscle groups are not well known, and these data are important in simulations of a subject's movements, and analysis of measured movements. Discrepancies in the force-velocity relation between in vivo and in vitro measurements have been documented in previous investigations. A powerful, high precision dynamometer was designed and built to make in vivo tests on the elbow and ankle joints. Test data obtained with this machine did not exhibit the same discrepancies observed in previous experiments, which leads to the conclusion that the previous discrepancies resulted from the test method used.

Biomechanical Phenomena↗
PubMed1998

Direct determination of urinary iodine by inductively coupled plasma mass spectrometry using isotope dilution with iodine-129.

An inductively coupled mass spectrometric method was developed for the direct determination of iodine in urine. The application of isotope dilution analysis with added 129I offers new possibilities for automatic and accurate determinations. The sample preparation consists of dilution with an ammonia solution containing 129I. The validation was made by comparison with the results obtained in another laboratory by a spectrophotometric method based on the Sandell-Kolthoff reaction. Different regression models, including maximum likelihood estimation, were used to compare the methods. None of the models revealed analytical bias between the two methods. The urine samples analyzed for validation were from three persons previously exposed to an iodine bath and covered a concentration range of 0.2 to 2.8 micromol/L. A detection limit of 0.02 micromol/L, a within-run CV of 2.5%, and a between-run CV of 11.9% were estimated for the proposed method.

Adult↗
PubMed1997

[Iodine supply at various periods in life and ultrasonographic thyroid volume in school children in a region of Switzerland].

In Switzerland the previous severe iodine deficiency has been corrected by iodization of salt. Changing food habits make it mandatory to periodically monitor iodine intake. In 1994 we therefore measured thyroid volume by sonography in 217 schoolchildren, and iodine, creatinine and sodium in casual urine samples of 214 schoolchildren, 40 pregnant women and 30 breast-fed newborns. Iodine was also measured in 30 breast milk samples. In schoolchildren, goiters of WHO grades Ia/Ib/II were found by palpation in 10.6/2.3/ 0.9%. By contrast, only two of the children had a sonographic thyroid volume exceeding the 97 percentile of the WHO, which underlines the difficulty of estimating the size of small goiters by palpation. Mean thyroid volume at 6/7/9/ 10/11 years of age was 2.1/2.2/3.3/3.3/3.1 ml, which is well within the normal range suggested by the WHO. Mean urinary iodine in schoolchildren (118 +/- 49 micrograms per gram creatinine) and in pregnant women (193 +/- 113 micrograms per gram creatinine) is within required limits, albeit with a decrease since 1988. In breast milk (7.8 +/- 5.9 micrograms/dl) and in urine of newborns (6.6 +/- 3.3 micrograms/dl) iodine values are below the Swedish reference values but well above values found in iodine deficient areas. We conclude that the iodine supply in schoolchildren and pregnant women is just sufficient and in newborns slightly below recently recommended limits. Compared to 1988 the iodine supply to schoolchildren is diminishing. The discrepancy between the rather low iodine content in breast milk despite a normal iodine supply during pregnancy remains to be explained.

Breast Feeding↗
PubMed1997

[Why is iodine deficiency once again present in the Berne region?].

Owing to the progressive iodination of salt in Switzerland (5, 10, 20 mg KI/kg in the years 1922, 1965, 1980), iodine deficiency in former endemic goiter regions had nearly disappeared. In several areas of the country, urinary iodine had increased from below 30 micrograms/24 h (1920) to > 100 micrograms/g creatinine (1981-1990). In 1991-1992, however, the 24-h-iodinuria in a subgroup of 160 examinations out of a total of 289 persons in Berne was again insufficient (norm > 150 micrograms J/24 h): mean 121 micrograms/24 h (82 micrograms/l), median 107.8 micrograms/24 h (67 micrograms/l). Follow-up of one proband in 1991-1992 (n = 9) and 1996 (n = 11) yielded average 24-h-iodinurias in the slightly deficient domain of (mean +/- SD) 104 +/- 57 micrograms/ 24 h (75 +/- 30 micrograms/l) and 103 +/- 27 micrograms/24 h (44 +/- 17 micrograms/l) respectively, with a wide range (45-258 micrograms l/24 h globally). Possible reasons for the decreasing iodide intake in recent years, resulting in the 1990s in a marginally deficient supply, are reduced intake of salt in recent decades, increased consumption of foodstuffs prepared with non-iodized salt, dietary diversification, and frequent meals away from the family table. Therefore, intake of non-iodized salt should be avoided in Switzerland.

Adult↗
PubMed1997

Chronic calcifying tendinitis of the shoulder-therapy by percutaneous needle aspiration and lavage: a prospective open study of 62 shoulders.

In an open study the therapeutic value of percutaneous needle aspiration and lavage performed in local anaesthesia under image intensifier control in patients with chronic calcifying shoulder tendinitis was investigated. 60 patients (62 shoulders) were included in the study. The average age was 48 years, and the median duration of shoulder pain and calcification was 24 months and 7 months respectively. The right shoulder was affected in 34 and the left in 24 patients; two patients had painful calcifications in both shoulders. In 47% X-ray showed calcium deposits in the contralateral shoulder. 77% of the painful deposits projected on the supraspinatus tendon and in most cases image intensifier examination showed multiple calcifications. Calcareous material could be removed by needle aspiration and lavage in 76% of all cases. There was no correlation regarding the preferred working hand and the side of calcifying tendinitis. X-ray controls performed after 2 months revealed a significant reduction of the size of calcifications. The clinical follow-up 2 and 6 months after needling showed a significant reduction of global pain intensity. There were also significant improvements in the areas of pain on movement, pain at night and impairment of sleep. Clinical success was independent of the radiological aspect of the calcifications.

Adult↗