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Biomedical subjects

R Hoffmann

Publications and source records attributed to R Hoffmann.

At least 541 records · Page 30Linked to original sources
PubMedDate not supplied

Acrodermatitis acidemica secondary to malnutrition in glutaric aciduria type I.

We encountered a patient with glutaric aciduria type I (GA-I) associated with skin lesions resembling acrodermatitis enteropathica (AE). This child was being fed with a low-protein diet when the skin disorder developed. A deficiency in plasma levels of essential amino acids, particularly isoleucine, and zinc was confirmed. Supplementation of a high-caloric, protein-rich diet together with zinc, selenium and vitamins led to a prompt improvement of the skin lesions. We assume that in our patient the skin lesions were the result of malnutrition, rather than being primarily associated with the underlying metabolic disease. To our knowledge, no other report is so far available concerning GA-I complicated by skin eruptions.

Acrodermatitis↗
PubMedDate not supplied

Enzymology of the hair follicle.

Androgenetic alopecia (AGA) is the most common type of hair loss in men and women. This continuous process results in a type of alopecia that follows a definite pattern in those individuals who are genetically predisposed. A genetic predisposition is a feature of AGA, but the predisposing genes are still unknown. Our understanding, however, of the hormonal effects on hair growth is far move advanced, and human hair follicles are not only targets for androgens, but also reveal an active androgen metabolism, with the ability to convert several androgens by different steroidogenic enzymes. Recent results suggest that the dermal papilla of the hair follicle expresses abundant type 2 5a-reductase, 3b-HSD and steroid sulfatase activity. Therefore, current information about the androgen metabolism in hair follicles is reviewed and the potential impact on future therapeutic approaches is discussed.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMedDate not supplied

TrichoScan: combining epiluminescence microscopy with digital image analysis for the measurement of hair growth in vivo.

Hair loss or hair thinning is a common complaint in clinical dermatology, and patients seeking advice for hair loss are not necessarily bald. Also the effects of treatment attempts are hard to measure. Consequently, there is a need for a sensitive tool to monitor hair loss and treatment response. Such a method must be able to analyze the biological parameters of hair growth, which are: 1: hair density (n/cm2), 2: hair diameter (mm), 3: hair growth rate (mm/day) and 4: anagen/telogen ratio. Here we present the TrichoScan as a method which combines epiluminescence microscopy (ELM) with automatic digital image analysis for the measurement of human, and potentially animal hair, in situ. The TrichoScan is able to analyze all biological parameters of hair growth with a so-called intraclass correlation of approx. ninety-one percent with the same TrichoScan operator and an intraclass correlation of approx. ninety-seven percent for different TrichoScan operators. The application of the technique is demonstrated by comparison of the hair parameters in individuals without apparent hair loss with men with untreated AGA and men after treatment with finasteride (1 mg/day), where we were able to detect a significant increase in hair counts and cumulative hair thickness 3 and 6 months after treatment. The advantage of the TrichoScan is that it can be used for clinical studies to compare placebo versus treatment or to compare different capacities of different hair growth promoting substances, it can be used for studying AGA or other forms of diffuse hair loss, and it can be adopted to study the effect of drugs or laser treatment on hypertrichosis or hirsutism.

5-alpha Reductase Inhibitors↗
PubMedDate not supplied

Trichoteiromania.

We describe a 61-year-old patient who compulsively rubbed her hair and her scalp because of a psychiatric disorder. Permanent rubbing resulted in fracturing of the hair shafts, leaving 2 cm long hairs and areas with stubs of 1mm length, giving the impression of bald spots. The distal ends of affected hair shafts were split, giving the impression of white tips. Light microscopy of the hair shafts showed split, brush-like ends of otherwise normal hair. We suggest the name trichoteiromania, which means "compulsive rubbing of hair", as a new term to describe hair loss in such cases.

Alopecia↗
PubMedDate not supplied

Treatment of alopecia areata in C3H/HeJ mice with the topical immunosuppressant FK506 (Tacrolimus).

Alopecia areata-like hair loss has been observed in C3H/HeJ mice and can be defined as a tissue-restricted T cell mediated disease of the hair follicle. Because FK506 has been described as suppressing T cell mediated autoimmune diseases, we addressed the question whether topical treatment of C3H/HeJ mice with FK506 has a beneficial effect on alopecia areata (AA). For this purpose six C3H/HeJ mice with AA were treated topically with 0.1% FK506 ointment, four mice received the vehicle only. Four of six FK506-treated mice showed complete hair regrowth, whereas 1/4 vehicle-treated mice regrew hair. Mice treated successfully with FK506 had reduced perifollicular infiltrates of CD4+ and CD8+ cells and a decreased expression of MHC class I and II and ICAM-1 on hair follicle epithelium, compared to control mice. We conclude that topical treatment with FK506 is able to induce hair regrowth in AA of C3H/HeJ mice, most likely by suppressing the T cell mediated immune response.

Administration, Cutaneous↗
PubMedDate not supplied

Lesions in chickens with spontaneous or experimental infectious hepato-myelopoietic disease (inclusion body hepatitis) in Germany.

A group of 83 two-to-eighteen-week-old chickens with acute infectious hepato-myelopoietic disease (a German form of inclusion-body-hepatitis) were observed to have the following histologic lesions: panmyelophthisis, small foci of liver necrosis, often with intranuclear inclusion bodies in hepatocytes (15 to 20% of chickens), involution-like atrophy of the bursa of Fabricius and thymus, loss of lymphatic tissue in spleen and cecal tonsils, and nonpurulent myocarditis. In 18 survivors 6 to 8 weeks after clinical signs of disease, nonpurulent myocarditis but normal lymphatic organs and bone marrow were present. A group of 75 chickens were infected after hatching with the field isolant "1942." Between the 3rd and 9th weeks postinoculation the same histologic changes-though mostly milder-were demonstrated. This syndrome differs somewhat from the syndrome described as inclusion body hepatitis in America and Europe.

Animals↗
PubMedDate not supplied

Histological development of lesions in the bursa of Fabricius of chickens with inclusion body hepatitis.

Twenty chickens, 4 weeks old, from a flock with spontaneous inclusion body hepatitis were observed for five weeks following the outbreak of disease. Biopsies were made of the bursae of Fabricius on days 1, 3 or 7, and 14 after housing, and the chickens were killed on day 35. Histologically, severe lesions in bursal follicles developed within a few days. At the end of the observation period the bursal structures had completely recovered.

Animals↗
PubMedDate not supplied

Production of tumor necrosis factor-alpha, interleukin-1 and interleukin-6 in the perfused rat liver.

The kinetics of the production and release of tumor necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1) and interleukin-6 (IL-6) were investigated in the perfused rat liver and in primary cultures of Kupffer cells after stimulation with lipopolysaccharide (LPS). A small and transient accumulation of TNF-alpha could be detected immunohistochemically and by cytotoxicity assay in the intracellular space about 1 h after addition of LPS to the cultured cells. TNF-alpha release in the perfused liver followed similar kinetics as those found in the serum of LPS-treated rats and in primary cultures of rat Kupffer cells. The cytotoxic TNF-alpha activity of the perfusate attained its maximum (11.5 +/- 2.6 U/ml) 90 min after LPS stimulation and remained nearly constant for further 150 min. 2 microM dexamethasone reduced the production of TNF-alpha by 10 g of liver during 240 min from 46 to 16 x 10(3) units. The production of IL-1 and IL-6 by 10 g of liver during the initial 240 min was 3 and 530 x 10(3) IU, respectively. The maximal concentrations of IL-1 (1.4 +/- 0.7 IU/ml) and IL-6 (157 +/- 60 IU/ml) were found 240 min after LPS addition. The production of IL-1 was totally suppressed by 2 microM dexamethasone.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗