PubMed Health⌕ Search

Biomedical subjects

C Hofmann

Publications and source records attributed to C Hofmann.

At least 163 records · Page 9Linked to original sources
PubMed1978

Islet-cell-surface antibodies in juvenile diabetes mellitus.

Using an indirect immunofluorescence test on suspensions of viable, insulin-producing islet cells from rats, we found that 32 per cent (28/88) of insulin-treated patients with juvenile diabetes have islet-cell-surface antibodies in their circulation. These antibodies also occurred in four of nine children with glucose intolerance, in one of 24 healthy children and in nondiabetic children with thyroid disorders. In the diabetic children, the immunofluorescent reaction was inhibited by preadsorption of serum to islet cells but was little affected by preadsorption to rat hepatocytes or erythrocytes or to acetone powders of various rat tissues, including pancreas. These results show that organ-specific, nonspecies-specific antibodies reactive with the cell surface of the islet cells can be present in serum from diabetic children, and provide an approach to investigation of immunopathological aspects of diabetes mellitus.

Adolescent↗
PubMed1978

[Photoaugmentation. a photobiological phenomenon (author's transl)].

The phenomenon of photoaugmentation was investigated in 37 male and female patients. UVA, UVB and UVC was applied with a high intensity grafting monochromator. Photoaugmentation could be induced following UVA plus UVB immediately or dissociated up to 3 h, but not after 24 h (15 J/cm2 lambda 351 less than or equal to 389 nm [UVA] + 13 mJ/cm2 lambda 290 less than or equal to 310 nm [UVB] = 1/2 MED). Simarily the reversed application of UVB plus UVA lead to photoaugmentation. With UVA plus UVC, photoaugmentation could not be elicited in every patient. Moreover, photoaugmentation was demonstrated in albino rabbits using a new light apparatus with a liquid filled light conducting core. Photoaugmentation seems to be an important biological phenomenon in association with sunburn, pigmentation, photoxicity, phototherapy, photochemotherapy, and UV-light induced cutaneous premalignanacies and malignancies.

Animals↗
PubMed1978

Photoallergic dermatitis from 8-methoxypsoralen.

A 36 year old woman with psoriasis vulgaris developed generalized photoallergic dermatitis to 8-methoxypsoralen after 16 uneventful treatments with 8-methoxypsoralen und UVA (PUVA). The diagnosis of photoallergy was confirmed by re-exposure to oral 8-methoxypsoralen and total body UVA irradiation; phototests using topical and oral 8-methoxypsoralen with a high intensity monochromator or with a new high intensity light apparatus for the delivery of UVA; and histological studies. Photoallergy occurred only with UVA, but not with UVB or UVC. There was no photoallergy following trimethylpsoralen.

Adult↗
PubMed1978

Promotion of monolayer formation in cultured whole pancreatic islets by 3-isobutyl-1-methylxanthine.

Normal adult rat islets usually remained intact and encapsulated, even after many days in culture. In contrast, islets cultured in the presence of the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (0.1 mM) attached more readily to the surface of plastic culture dishes and almost uniformly formed monolayers of endocrine cells. The mechanism of this effect is not known but presumably involves increases in cellular cyclic AMP content. Fibroblast growth did not appear to be stimulated by the inhibitor. These adult pancreatic endocrine monolayer cultures can be produced readily and provide useful preparations for further morphological and biochemical studies of factors affecting the differentiation, growth, and regenerative capacity of islet cells.

Animals↗
PubMed1978

A new apparatus for the delivery of high intensity UVA and UVA+UVB irradiation, and some dermatological applications.

A new apparatus consisting of a 200 W super pressure mercury lamp and a flexible light guide with a liquid light-conducting core is presented. Its transmission for UVA irradiation is more than threefold as compared to conventional quartz fibre optic bundles. The light guide is capable of transmitting density levels exceeding I W/cm2. UVA and UVB are transmitted. By inserting a filter platelet (WG 345) into the light guide the UVB is cut off. The output of the unfiltered guide is 700 mW (3570 mW/cm2), of the filtered guide 400 mW (2040 mW/cm2), centered mainly at 366 nm. The light apparatus proved useful for several dermatological applications. It replaces in many respects conventional Kromayer lamps, especially because the flexible light guide, which is 160 cm long and weighs only 210 g, can be brought into direct contact with the skin. Results of determining the minimal erythema dose (MED), of phototesting (8-MOP photoallergy, persistent light reactor, erythropoietic protoporphyria) and of photochemotherapy are given.

Acrodermatitis↗
PubMed1977

[Photochemotherapy of cutaneous lymphoma: oral and local 8-MOP-UVA treatment (author's transl)].

8-Methoxypsoralen (8-MOP) and long-wave ultra-violet light (UVA) were administered to 16 patients with mycosis fungoides and to three with other cutaneous lymphomas. Total body clearing was achieved in eleven patients, while temporary recurrences were observed in three, maintenance treatment arresting the recurrences. In the others all treatment failed. Histological and enzyme-cytochemical studies indicate that the histological features under 8-MOP-UVA treatment correspond to those induced by other forms of treatment: a lose enzyme-cytochemically negative lymphocytoid infiltrate remaining around blood vessels, after regression of the skin disease. Oral 8-MOV-UVA treatment (12 patients) proved superior to topical treatment (seven patients), because cutaneous lymphoma is a systemic disease. In mycosis fungoides the mean number of exposures causing clearance of skin lesions and the mean UVA dose (single treatment) were generally less than those for psoriasis vulgaris.

Aged↗
PubMed1977

[Histopathology and histochemistry of psoriasis under photochemotherapy (author's transl)].

Fifty-two biopsies from involved and clinically normal looking skin of patients with psoriasis vulgaris and from normal control subjects, all being treated with 8-MOP-UVA (PUVA) were obtained between days 2 and 300. The following parameters were investigated: 1. initial PUVA effects; 2. initial regression of psoriasis under PUVA-therapy; 3. late effects of PUVA-therapy on regression of psoriatic lesions; 4. EFFects on melanocytes and pigmentation; and 5. long-term effects of PUVA-therapy. Paraffin embedded and cryostat sections were prepared with routine stains for light microscopy and enzyme histochemical special stains. The regression of psoriatic lesions following PUVA-therapy was separately assessed for epidermal and dermal components. The sequence of events was as follows: re-establishment of a continous stratum granulosum, re-establishment of a continuous normal appearing stratum corneum, regression of acanthosis and papillomatosis, and regression of inflammatory infiltration. During the initial phase of PUVA-therapy there is a sharp increase of melanocytes which leads to a foamy appearance of the basal cell area. Long term studies did not reveal actinic damage of the skin, neither in the epidermis (absence of actinic keratoses or squamous cell carcinomas) nor in the dermis (absence of actinic "solar" elastosis).

Histocytochemistry↗
PubMed1977

Insulin as a cellular growth regulator.

Previous studies from this laboratory have shown that insulin treatment greatly stimulates liver cell growth in chronically diabetic rats. The effect is striking, being preceded by massive glycogen deposition and water imbibition as well as enchanced RNA and protein synthesis. More recently we have directly confirmed the stimulatory effects of insulin on liver RNA and glycogen synthesis in intact hepatocytes isolated from normal and diabetic rats. The hepatocytes specifically bind insulin (KD = 3.5X10(-9) M) and the bound hormone is degraded systematically, indicating the possibility of receptor-mediated uptake of the hormone. Recent studies in other laboratories of the growth factors, non-suppresible insulin-like activity (NSILA) and nerve growth factor (NGF), as well as of relaxin, have disclosed structural relationships between these peptides and pro-insulin, indicating the existence of families of closely related anabolic effectors. A new hypothesis regarding the role of the insulin-receptor complex in initiating the metabolic and mitogenic effects of the hormone is briefly discussed.

Amino Acid Sequence↗
PubMed1976

[Acute febrile neutrophilic dermatosis Sweet's syndrome].

Acute febrile neutrophilic dermatosis was diagnosed in three middle-aged women. It started characteristically one to three weeks after infection of the upper respiratory tract with sudden fever and painful, inflammatory, multiform skin lesions. There was marked leucocytosis and neutrophilia. The disease is characterized by dense, perivascular, neutrophil-granulocytic infiltrates associated with lymphocytic-histocytic reactions at the margins. Site and dynamics of the histological changes suggest an immune-complex disease. However, direct immunofluorescence has not given any characteristic findings. In general the prognosis is good, the disease rapidly responding to systemic glucocorticoids. But there are also spontaneous remissions, as in two of the described cases.

Biopsy↗
PubMed1976

Immunological and structural evidence for patterned intussusceptive surface growth in a unicellular organism. A postulated role for submembranous proteins and microtubules.

The surface complex of Euglena has been examined intact and after isolation and purification by the use of mild sonication to disrupt cells. In intact cells the surface complex (pellicle complex) is oriented in a series of parallel ridges and grooves, and possesses among other components a characteristic group of four to seven microtubules. Isolated pellicles retain the ridge and groove pattern but no microtubules are present. Isolates yielded at least three major polypeptides on SDS acrylamide gels; one or more of the polypeptides are postulated to be identical with a submembrane layer present in both intact and isolated pellicles; one polypeptide appears to be in or on the surface membrane. Antibodies directed against the isolated pellicles were conjugated directly or indirectly to fluorescein, latex spheres, or ferritin. In appropriate experiments with these antibody conjugates, it has been found that antigenic sites are immobile and that new antigenic sites (daughter strips) are inserted between parental strips in replicating cells. These results together with direct observation of daughter strips by transmission electron microscopy suggest that surface growth in Euglena occurs by intussusception. Microtubules associated with the pellicle complex are postulated to play a role in the development of new daughter strips, and possibly also in cell movements.

Antigens↗