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Biomedical subjects

H Gerber

Publications and source records attributed to H Gerber.

At least 91 records · Page 5Linked to original sources
PubMed1995

Partial sequence of the equine immunoglobulin epsilon heavy chain cDNA.

In order to isolate a part of the immunoglobulin E (IgE) heavy chain cDNA of the horse, primers have been designed based upon well conserved sequences in humans, sheep and rats. The PCR resulted in a 500 bp fragment which hybridised with a human IgE constant region probe. The fragment was cloned and sequenced and its derived protein sequence compared with the corresponding sequences in humans, sheep and mice. Most amino acids common to these three species are also shared by the horse.

Amino Acid Sequence↗
PubMed1995

Vasculitides in hairy cell leukemia.

Forty-two cases of vasculitis coincident with hairy cell leukemia (HCL) have been reported, of which 17 had panarteritis nodosa (PAN), 21 had cutaneous leukocytoclastic vasculitis (LCV), and 4 had vessel wall infiltration by hairy cells. PAN generally occurred after the diagnosis of HCL, splenectomy, and infection. HBs antigen was detected in 3 of 12 patients tested, whereas immune complexes were positive in 3 of 4 patients tested. LCV was often preceded by infection and was frequently detected before HCL. Serum immunoglobulin levels were generally elevated when measured. Cryoglobulins, complement, rheumatoid factor, and antinuclear antibodies showed no clear association with vasculitis in HCL. These reports suggest a role for infection and splenectomy as contributing factors to vasculitis.

Adult↗
PubMed1995

Epidermal growth factor stimulates cell proliferation and inhibits iodide uptake of FRTL-5 cells in vitro.

In accordance with the available data most authors conclude that epidermal growth factor (EGF) has very little or no effect on FRTL-5 cells. This has been viewed as a serious handicap of this cell line. In the present study we cultivated three strains of FRTL-5 cells from different sources and assessed their response to EGF with regard to proliferation, function and differentiation. Cell proliferation was assessed by counting in a Coulter cell counter after culturing cells at suboptimal conditions in well plates. Cell function was studied by measuring iodide uptake. Cell differentiation was examined immunocytochemically by staining monolayer cultures for thyroglobulin (Tg) and EGF receptor (EGFr) as well as morphologically by microscopical evaluation of monolayer cultures. All three FRTL-5 cell lines investigated express EGFr. In two wild type FRTL-5 cell lines EGF stimulates growth, an effect that is enhanced by the presence of TSH, and partially inhibits iodide uptake. A third mutated strain of FRTL-5 cells does not respond to EGF. Tg expression can be demonstrated immunocytochemically in EGF-treated cells as well as in controls. Morphologically, in monolayer culture EGF-treated cells cannot be distinguished from controls. Contrary to previous reports, these studies demonstrate EGF effects on FRTL-5 cells that are consistent with EGF effects established in other thyroid follicular cells.

Animals↗
PubMed1994

[Osteoporosis screening--indications for bone densitometry].

Osteoporosis is a major public health problem because of increasing prevalence and the cost of related morbidity, especially fractures of the spine and hip. The perimenopausal evaluation of risk patients by assessment of clinical risk factors and bone-mass measurements are used to select patients for prevention of postmenopausal and age-associated bone loss. The value of bone-mass for prediction of fracture-risk and the clinical significance of bone-densitometry for patient management is reviewed. Four essential clinical indications for bone mass assessment are discussed.

Absorptiometry, Photon↗
PubMed1994

[Gonorrheal arthritis].

A 43-year-old female patient presented with migratory arthralgias, generalized exanthema and arthritis of the left elbow. She had a history of fever and chills three days earlier. Beside to a maculopapular and pustular rash and a joint involvement we found a swelling of the dorsal surface of her right hand without wrist effusion or synovitis. The clinical presentation was typical for the diagnosis of disseminated gonococcal infection (arthritis-dermatitis syndrome). Arthrocentesis was performed, and the cultures of the synovial fluid on chocolate agar were positive for Neisseria gonorrhoeae. The serologic examination for gonococcus was negative, it became positive some weeks later. The therapy with intravenous penicillin G 6 x 10(6) units/day for ten days was successful; unfortunately, we could not treat the partner. The present case report is illustrated with colour prints and describes the typical clinical picture of a diagnosis which is nowadays rare or even forgotten.

Adult↗
PubMed1994

Etiopathology of feline toxic nodular goiter.

We have discussed the etiopathology of feline toxic nodular goiter in the context of human nodular goiter pathogenesis. We have reviewed thyroid heterogeneity, growth regulation, functional and growth autonomy, nodule and tumor formation, and the evolution of toxic nodular goiter in the human being. By addressing toxic nodular goiter of the cat, the history, morphologic findings, xenotransplantation and cell culture studies, evidence for and against circulating thyroid stimulators and epizootiological studies of the feline disease have been summarized. Due to its structure, the thyroid gland offers some unique possibilities to study the mechanisms that are responsible for cellular heterogeneity, the emergence of autonomous nodular growth and function, and, ultimately, the development of tumors. The demonstration of naturally occurring clones of cells with high intrinsic proliferation potential within the follicular epithelium of the thyroid has fostered promising new concepts on the genesis of nodular growth of benign and possibly malignant endocrine tumors. Hyperthyroid cat goiters contain single or multiple, autonomously (i.e., TSH-independently) functioning and growing nodules. Neither hyperfunction nor growth of these nodules depends on extrathyroidal circulating stimulators. The basic lesion appears to be an excessive intrinsic growth capacity of some thyroid cells. The factors enhancing the transformation of a normal thyroid into a nodular hyperfunctioning goiter over many years are still unknown. Immunological, environmental, and nutritional factors are the focus of ongoing studies, but an infectious agent can not yet be excluded.

Animals↗
PubMed1994

Studies on the frequency and associations of equine leucocyte antigens in sarcoid and summer dermatitis.

The equine leucocyte antigen (ELA) types and the clinical diagnosis for equine sarcoid and summer dermatitis were evaluated in 2026 horses representing five breeds. Data were analysed in unrelated animals and in family material. In the case of equine sarcoid, a strong association was observed between the ELA class II DW13 antigen and its effect on Swiss (cP < 0.001), French (cP < 0.0001) and Irish (cP < 0.01) Warmblood horses. The class I antigen A3 occurred more frequently in sarcoid-affected French horses (cP < 0.001). These results confirm our earlier findings (Gerber et al. 1988). Among Freiberger horses, which lack the ELA DW13 and A3 specificities, a breed-specific class I antigen, ABe108, displayed an increased frequency (cP < 0.05) in the affected group. Among Arabian horses, a tendency for increased frequency of the A1 antigen was observed in the affected animals, but the number of affected horses is too small for statistical significance. The Mendelian segregation in diseased half-siblings by ELA DW13 heterozygous stallions showed a strong association (P < 0.0001) between the inherited DW13 antigen and susceptibility to the sarcoid effect. In the case of summer dermatitis, previously published data (Marti et al. 1992) have been extended. The ELA types in four multiple-case families, founded by the same stallion, were analysed for an association with the effect of sarcoid. Eight out of nine ELA-typed affected offspring inherited the paternal haplotype A15, DW23 in contrast to nonaffected offspring where three out of 12 displayed these antigens (P < 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Alleles↗
PubMed1994

Childhood epidermolysis bullosa acquisita.

We report a 6-year-old boy suffering from acquired epidermolysis bullosa, who presented with extensive lesions of the mucous membranes and disseminated, herpetiform and 'cluster of jewels'-like vesicles and bullae arising on erythematous plaques. Direct immunofluorescence showed linear deposits of IgG and C3 at the epidermal basement membrane zone. Indirect immunofluorescence demonstrated circulating autoantibodies (titre 1:128-1:256) directed at the blister floor of human NaCl-split skin, and reacting specifically with collagen VII of the anchoring fibrils, as demonstrated by immunoblotting. The disease was controlled with a combination of dapsone and prednisone. This case demonstrates the importance of modern immunological techniques in classifying childhood autoimmune bullous diseases, as precise diagnosis is important in determining an appropriate therapeutic regimen.

Autoantibodies↗
PubMed1994

Experimental treatment of equine sarcoid using a xanthate compound and recombinant human tumour necrosis factor alpha.

A xanthate compound with antiviral and antitumoural activities, tricyclodecan-9-yl-xanthogenate (D609) in combination with the potassium salt of the lauric acid (KC12) and, in a further investigation, the above-mentioned substances together with recombinant human TNF alpha (rh-TNF alpha), were tested on equine sarcoid tumours for therapeutic efficacy. A pilot investigation on 5 healthy horses showed that the compounds were well-tolerated; apart from a local, temporary oedema at the injection site, no other clinical symptoms were observed after subcutaneous administration of volumes from 0.1 to 10 ml per injection. The tested concentrations of D609 and KC12 (5 mg/ml solution) and of rh-TNF alpha (50 micrograms/ml) were used for the treatment experiments. The repeated injections of the compounds to 11 sarcoid affected horses were also well-tolerated, except by one horse. In this case the treatment had to be interrupted after two injections because of severe reaction, i.e. fever and lameness due to oedemas. Five horses (n = 6 sarcoids) were treated by local, subcutaneous injection of D609 and KC12 under the tumour at intervals of 3 weeks. On one periocular sarcoid the compounds were applied as an ointment. After a follow-up period of 18 months, 5 tumours did completely regress and one remained unchanged. The periocular tumour showed a reduction in size. Five horses (n = 9 sarcoids) were then treated with a combination of D609, KC12 and rh-TNF alpha.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Transformation of normal thyroids into colloid goiters in rats and mice by diphenylthiohydantoin.

Some years ago, we reported that colloid goiters could be produced experimentally in mice and rats by injection of TSH over a few days in the presence of ample iodine supply. This clearly showed that colloid accumulation and intense TSH stimulation are not mutually exclusive. In the present study, large colloid goiters, sharing many morphological and biochemical characteristics with human colloid goiters, were induced in rats and mice by treatment with 5,5-diphenyl-2-thiohydantoin (DPTH). This drug increases fecal loss of thyroid hormone and inhibits conversion of T4 to T3. Thus, DPTH raises TSH and induces macrofollicular colloid-rich goiters. In contrast to this, goiters induced by combined treatment with methimazole (MMI) or sodium perchlorate and DPTH are microfollicular, although serum TSH is increased to the same level as in rats treated with DPTH alone. The degree of iodine organification obviously determines if the follicle will sprout and form daughter follicles or if it will expand its hull. Thyroglobulin content of DPTH goiters is lower than that of normal glands but considerably higher than after MMI treatment, whereas total iodine content of DPTH goiters is only slightly lower than in normal glands, but also much higher than in MMI goiters. In DPTH goiters, a high proportion of total iodine is in the particulate fraction which probably contains the periodic acid Schiff-positive bodies floating in the colloid of DPTH treated glands. Acute DPTH administration does not inhibit iodide organification, but after treatment with DPTH for 1 day, chromatography suggests some inhibition of iodine organification and hormone synthesis by DPTH, but much less than by MMI. DPTH treatment causes considerable tissue damage and repair, such as follicular cell necrosis and invasion of the colloid by macrophages and granulation tissue. Therefore, DPTH goiters might well be a useful model not only for colloid goiter formation but also for inflammatory processes in the thyroid gland.

Animals↗
PubMed1994

The degree of inhibition of thyroid follicular cell proliferation by iodide is a highly individual characteristic of each cell and differs profoundly in vitro and in vivo.

Pharmacological concentrations of iodide (> 1 x 10(-6) mol/l) are known to inhibit thyroid follicular cell growth in vitro. However, the inhibitory effect varies widely, depending on experimental conditions, and usually does not exceed 50%. We demonstrate that iodide (10(-4) mol/l) inhibits the growth of FRTL-5 cells in different passages by 11-67%. When five subclones of FRTL-5 cells were compared to the wild type, iodide-induced growth inhibition varied between 25% and 46%. The individual degree of inhibition of each clone was reproducible in two subsequent passages, suggesting that it is a stable constitutive trait. When FRTL-5 cells were grown first in three-dimensional clusters and then transplanted onto nude mice with high endogenous thyrotropin secretion, iodide at a serum concentration of less than 5.7 x 10(-7) mol/l nearly completely blocked cell replication in the transplants but not in the mice's own thyroid. Five cell lines, prepared from autonomously growing hyperthyroid feline multinodular goiters, were nearly completely resistant to the growth-inhibitory effect of iodide. These observations suggest that the sensitivity towards the growth-inhibiting effect of iodide is a highly variable, stable trait of each thyrocyte, even in cloned cell populations. Some FRTL-5 cells and, even more so, cells prepared from autonomously growing nodular feline goiters are resistant constitutively to the growth-inhibiting effect of iodide.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

[Development and adaptation of tensile strength by bones in the extremities in response to physical training exemplified by the tibia].

Results from an in vivo assessment of the bending stiffness of human tibiae with a new method demonstrate that bone mineral measurements are not a suitable predictor to evaluate changes of mechanical properties of long bones. In a study on 559 male military recruits, the bone mineral at tibial shaft resulted in a mean increase of +1.8% during 15 weeks of exercise. The bending stiffness however increased about 25%. An additional test 24 months later on a sample indicated that the increase of bone mineral content was only due to the natural maturation of bone. The bending stiffness however, decreased by about 6% demonstrating the earlier training effect. No correlation between bone mineral and bending stiffness could be found neither in absolute values nor in difference between the three measurements. At the same time first results of a normative study on children (9 to 18 years old, male and female) and on women (up to 80 years old) are presented.

Adolescent↗
PubMed1994

Primary biliary cirrhosis (PBC): antigen-presenting cells differ in their distribution in early and late stage PBC and involve the ductal, but not the ductular compartment.

We have studied the distribution patterns of antigen-presenting cells (APCs) in different stages of primary biliary cirrhosis (PBC). 58% of cases with early PBC (stages I and II) exhibited dendritic APCs (S-100+, HLA-DR+, KiMlp+) in bile duct epithelia. In contrast, APCs, were not detected in ductular proliferations occurring in late PBC (stages III and IV), but occurred in portal tracts and piecemeal necroses. There was a correlation between the presence of APCs and HLA-DR expression in bile ducts but, in contrast to former studies, we noted a heterogeneous ductal HLA expression. These observations support the hypothesis that: 1) APC distribution in PBC may change as a function of stage, involving hepatic parenchyma in late PBC; 2) ductular epithelia may not represent a target for immune attack, because APCs do not accumulate in these structures; and 3) HLA expression in bile ducts may be heterogeneous, suggesting one mechanism why bile duct destruction in PBC does not take place in a synchronous way.

Adult↗
PubMed1993

[Suspected adult-onset Still's disease: unexpected manifestation of leprosy].

A 23-year old male from Sri Lanka was admitted to hospital with symmetrical inflammatory peripheral polyarthritis, fever of 39 degrees C and poly-lymphadenopathy. At first we suspected adult onset Still's disease. The histological findings from axillary lymph node biopsy strongly suggested the diagnosis of leprosy, for which we had had little evidence thus far. Typical skin lesions were absent, skin smears were negative and neurological symptoms only became obvious much later when fever and arthritis had subsided under anti-inflammatory treatment. At this time a right ulnar palsy developed, with atrophy of the interosseous muscles and thickening of the ulnar nerves at both medial epicondyles. Fite-stains of a sural nerve biopsy confirmed the diagnosis when mycobacteria were detected. Leprosy displays a clinico-pathological spectrum caused by variations in host resistance. A widely accepted classification is the five group system of Ridley and Jopling. At one extreme of this spectrum are patients with lepromatous or low resistance leprosy with numerous bacilli, and at the other those with high resistance or tuberculous leprosy where few or no bacilli are found. The numerous bacilli in the sural nerve biopsy classified the disease as lepromatous in our case. Of the various manifestations of the lepra reaction occurring in lepromatous leprosy, one is acute arthritis, but a more common one is erythema nodosum leprosum. Our patient's clinical presentation was interpreted to be a rheumatic manifestation of a type-2 reaction. This form of immunological response in leprosy is an immune complex syndrome and may mimic different rheumatic diseases.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

DNA of bovine papillomavirus type 1 and 2 in equine sarcoids: PCR detection and direct sequencing.

Nucleotide sequences of bovine papillomavirus (BPV) DNA amplified by the polymerase chain reaction (PCR) from samples of equine sarcoid skin tumours were determined. All naturally occurring sarcoids (n = 58 tumours from 32 horses and 2 donkeys) contained BPV-DNA. All but 3 of the genome fragments belonged to the BPV type 1 strain (BPV-1); the remaining were BPV type 2. Similar results were obtained with cutaneous bovine papillomas used as controls (n = 20). One of the horses, carrying 2 sarcoids, was particularly interesting; one tumour contained BPV-1 DNA whilst the other sarcoid yielded BPV-2 DNA, suggesting that horses are not immune to super-infection. BPV-DNA was even amplified from the sarcoid samples which had yielded negative results in previous investigations when DNA isolated from the lesions was used in Southern blot hybridization with BPV probes. In addition, there was no detectable BPV-DNA in any equine or bovine tissue examined other than sarcoids or cutaneous bovine papillomas. Biopsies of normal skin surrounding lesions yielded exclusively negative results. The described nucleotide differences represent a natural genomic variation of this BPV type between geographically distant locations. The identical variations recovered from cattle and horses in Switzerland, a finding of great epidemiological interest, strongly suggest that a uniform variant of BPV-1 is one of the etiologic agents of equine sarcoid and bovine papilloma in a given region.

Animals↗