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Biomedical subjects

H F Haberman

Publications and source records attributed to H F Haberman.

At least 55 records · Page 3Linked to original sources
PubMed1979

Photolysis of mast cells in presence of protoporphyrin.

The effects of ultraviolet and visible irradiation in presence of protoporhyrin upon mast cells were investigated. Rat peritoneal mast cells were suspended in a medium containing varying concentrations of protoporphyrin and were irradiated using a mercury vapor lamp. The release of histamine is related to both the concentrations of protoporphyrin and the period of irradiation. Comparatively negligible amounts of histamine were released when the cells were irradiated in absence of protophyrin or when the cells were incubated in the dark in presence of protoporphyrin. When 51Cr-labelled cells were employed, the release of histamine was paralleled by the release of 51Cr. These results suggest that the release of histamine was due to the lysis of cells. It was found that 2-deoxyglucose, iodoacetate and carbonyl cyanide, m-chlorophenyl hydrazone at concentrations which are known to inhibit the secretory release of histamine or uncouple oxidative phosphorylation, had no effect on the photolysis of mast cells. When mast cells were irradiated in presence of protoporphyrin for 5 to 10 minutes and then kept in the dark, the release of histamine was greater than when the cells were irradiated but not subsequently kept in the dark. It is suggested that the initial site of photochemical lysis is at or near the cell surface.

Animals↗
PubMed1978

Treatment of psoriasis with orally administered 8-methoxypsoralen and long-wavelength ultraviolet radiation.

Between May 1976 and September 1977, 51 patients with severe psoriasis were treated with orally administered 8-methoxypsoralen followed by exposure to high-intensity long-wavelength ultraviolet radiation. Clearing of psoriasis occurred in 40 patients (78%) and marked improvement in 5 (10%). Of the remaining patients three (6%), who had generalized erythroderma, failed to respond to this therapy. The mean number of treatments required for clearing was 37.5. No serious side effects were noted clinically, by ophthalmologic examination or by laboratory testing. This therapy has some advantages over conventional types of treatment now used for severe psoriasis, but also has limitations. It appears to be an effective method of treatment for ambulatory patients. Further long-term follow-up studies are required to evaluate its side effects.

Administration, Oral↗
PubMed1978

Extramammary Paget's disease.

In a 74-year-old man extramammary Paget's disease of the scrotal and perianal areas masqueraded as tinea cruris and chronic dermatitis for 7 years before it was diagnosed. Topical therapy with 1% 5-fluorouracil cream resulted in clinical improvement but not histologic clearing.

Aged↗
PubMed1978

Formation of melanin-tyrosinase complex and its possible significance as a model for control of melanin synthesis.

Previous reports have shown that the tyrosinase activities of melanosomes and soluble tyrosinase isolated from melanoma were diminished when these preparations were incubated with 3,4-dihydroxyphenylalanine (dopa). It was concluded from these results that the tyrosinase activities of these preparations decreased when melanin was synthesized in these systems. The present investigation has revealed that melanin synthesized in vitro from dopa formed a complex with purified mushroom tyrosinase. The addition of melanin diminished the tyrosinase activity of the sample. These results show that the formation of the melanin-tyrosinase complex results in a decrease in the activity of the tyrosinase solution. The tyrosinase activity of the melanin-tyrosinase complex could not be increased by certain procedures which were previously found to enhance the tyrosinase activity of isolated melanosomes.

Catechol Oxidase↗
PubMed1976

The use of freeze-fracture and negative staining techniques to study the ultrastructure of melanosomes isolated from B16 melanoma.

Freeze-fracture negative staining methods were used to investigate the structure of melanosomes isolated from B16 melanoma. The findings demonstrated the presence of a melanosomal double-layered membrane. Negative staining procedure showed that the melanosomal membrane is sometimes ruptured, displaced or peeled off during the purification process. Fractured melanosomes showed melanin spheres with a mean diameter of 24 nm. This compares with a mean diameter of 26 nm for the melanin spheres revealed by negative staining. The granular appearance of fractured mature melanosomes is due to the fracture following a random path between melanin spheres.

Animals↗
PubMed1976

Junctional and compound pigmented nevi induced by 9, 10-dimethyl-1,2-benzanthracene in skin of albino guinea pigs.

Seventy albino guinea pigs were used in the experiment to investigate the influence of 9,10-dimethyl-1,2-benzanthracene on amelanotic melanocytes. A field 5 sq cm was marked on the flank of each animal. Hairs from these fields were clipped twice a week and painted for 20 consecutive weeks with 0.3 ml of 1% 9,10-dimethyl-1,2-benzanthracene in acetone. During the 1-year observation period, pigmented sports appeared in 40 animals. Biopsies were taken under local anesthesia, and sections were prepared for light and electron microscopic observations. Melanin formation of unknown mechanism took place in the epidermal melanocytes and in the melanocytes from the outer root sheath. These melanocytes also formed junctional and compound nevi; serial sections revealed various stages of pigmented nevi development. Schwann cells did not participate in the formation of nevi. Evidence is presented that 9,10-dimethyl-1,2-benzanthracene can convert amelanotic melanocytes into melanin-producing cells in the albino guinea pig skin. In addition, this system produces an animal model for the development of junctional and compound nevi.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1975

Photosensitivity: results of investigation in 250 patients.

Between January 1972 and December 1974, 250 patients were referred for investigation of possible photosensitivity to a university-associated clinical research unit for photobiology. In addition to an appropriate history and clinical examination, phototesting was carried out with a solar simulator, monochromatic light and fluorescent light directed to patch-tested areas of skin. Photosensitivity was not demonstrated in 110 patients (44%). Among the laboratory-confirmed photosensitivities, diagnoses included polymorphous light eruption (4.4%), erythropoietic protoporphyria (3.6%), porphyria cutanea tarda (2%), photoallergic contact dermatitis (5.6%), persistent light reaction (4%), systemic drug phototoxicity (1.2%), phototoxic contact dermatitis (2%), solar urticaria (0.8%) and photoaggravated dermatoses (7.6%). It is important to establish a precise etiologic diagnosis in patients with photosensitivity in order to treat the disorder specifically or effectively or both.

Adolescent↗
PubMed1975

Porphyria cutanea tarda: comparison of cases precipitated by alcohol and estrogens.

A group of seven patients with porphyria cutanea tarda (PCT) precipitated by excessive alcohol consumption (A) was compared with a group of nine patients with PCT precipitated by estrogen therapy (B). Comparison was based on clinical signs, biochemical and morphologic evidence of liver disease, results of serum iron studies and response to therapy. Group A patients were men of mean age 57 years; group B patients were women of mean age 39 years who had been taking estrogen orally, either for contraception (in combination with progesterone) or as replacement therapy. Clinical signs were essentially the same in the two groups. Some patients in both groups had biochemical and morphologic evidence of liver disease. Group A patients had elevated values for serum iron and total iron-binding capacity, whereas patients in group B had normal or low values. Cessation of estrogen therapy of less than a year's duration brought about a spontaneous clinical and biochemical remission in group B patients. Otherwise, phlebotomy seemed to be the therapy of choice in both groups.

Adult↗
PubMed1975

Simple and sensitive test for the determination of phenolic compounds in urine and its application to melanoma.

A simple procedure is outlined for the determination of phenolic compounds in urine. The method involves the diazotization of p-nitroaniline and subsequent coupling of the diazonium chloride with phenolic compounds. The diazo compound formed is determined by measuring the absorbance at 400 nm. The extinction coefficients for several compounds have been determined. Application of this method to determine the levels of phenolic compounds in urine in patients with melanoma showed that the assay may be of diagnostic value. The amounts of phenols in 24-hr urine samples from patients with melanoma, patients with various other diseases, and healthy individuals were determined. A statistical analysis of these results showed that the results for patients with melanoma were higher than those for healthy individuals and patients with other diseases at 1 percent probability level. A comparison of this test with three other methods (Thormählen test, ferric chloride test, and ferrocitrate test) for determination of melanogens showed that the diazo test is the most sensitive one for detecting melanoma.

Colorimetry↗
PubMed1975

Use of affinity chromatography for purification of tyrosinase.

The possibility of using affinity chromatography for the purification of tyrosinase was explored. When purified mushroom tyrosinase was employed, almost all tyrosinase became bound to Sepharose containing 3-iodotyrosine, an inhibitor of tyrosinase. When crude extracts from B16 melanoma were employed, partial purification of tyrosinase and separation of two or possibly three forms of tyrosinase could be obtained. The results indicate that affinity chromatography could possibly be employed for the purification of tyrosinase during the final stages of the purification procedures.

Basidiomycota↗