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Biomedical subjects

E Frenk

Publications and source records attributed to E Frenk.

At least 55 records · Page 3Linked to original sources
PubMed1993

The Nägeli-Franceschetti-Jadassohn syndrome: A hereditary ectodermal defect leading to colloid-amyloid formation in the dermis.

Light- and electron-microscopical examination of 4 skin biopsies from 2 members of the initially described family with Nägeli-Franceschetti-Jadassohn syndrome revealed that the already reported pigment incontinence is accompanied by varying amounts of colloid-amyloid bodies located in the superficial dermis. Occasionally, such bodies could also be seen around sweat glands in the reticular dermis. These findings indicate that cutaneous colloid-amyloid formation could be a pathogenic factor in the phenotypic expression of this autosomal dominant syndrome.

Amyloid↗
PubMed1993

Hermansky-Pudlak syndrome in a Swiss population.

Tyrosinase-positive albinism, previously diagnosed as Hermansky-Pudlak Syndrome (HPS), has been examined in four generations from a village of the canton Valais, Switzerland. Homozygotes, obligate heterozygotes and putative heterozygotes in this geneology yielded lower than normal membrane-associated thioredoxin reductase (TR) activities compared with normal family members and controls. All of the homozygotes and 50% of each the obligate and putative heterozygotes showed an increase in bleeding time associated with storage-pool-deficient platelets lacking dense bodies. The TR activity profile and the platelet-dense body deficiency in the Swiss albinos was the same as that in the HPS population from Puerto Rico. However, in albinos from Puerto Rico, there is an accumulation of ceroid/lipofuscin-like pigment in lysosomal structures causing tissue damage, and, upon kidney involvement, this leads to increased urinary dolichol excretion. Approximately half of the Puerto Rican HPS cases had clinical evidence of storage disease with restrictive lung disease, granulomatous colitis, kidney failure and cardiomyopathy. By comparison, the Swiss HPS geneology had a normal life expectancy with no significant evidence for ceroid accumulation or urinary dolichol excretion. An examination of antioxidant enzymes, catalase, TR and glutathione reductase in epidermal suction blisters from Swiss HPS homozygotes showed a similar result for catalase and TR levels to the depigmented epidermis of patients with vitiligo, except that intracellular TR was found to be calcium free in HPS compared with vitiligo. Intracellular glutathione reductase levels were highest in HPS. Both the Swiss and Puerto Rican HPS homozygotes and heterozygotes have giant melanosomes in skin melanocytes.

Adolescent↗
PubMed1993

Bullous systemic lupus erythematosus. Report of a case with lupus erythematosus cells in the dermis.

A 20-year-old black patient with bullous systemic lupus erythematosus developed papular and vesicular lesions on the extensor surfaces of the extremities. Histologically, subepidermal blisters and papillary neutrophilic abscesses with a striking number of lupus erythematosus cells were observed. No circulating anti-basal-membrane-zone antibodies were found. By Western immunoblotting, the patient's serum showed no reactivity against epidermal or dermal extracts.

Adult↗
PubMed1993

Superficial granulomatous pyoderma.

We report the case of a 66-year-old man presenting 2 chronic, slowly expanding skin lesions having clinical and histopathological characteristics of superficial granulomatous pyoderma. Sulfone treatment induced healing with scar formation.

Abscess↗
PubMed1993

Analysis of the cornified cell envelope in lamellar ichthyosis.

BACKGROUND: Loricrin and involucrin are major precursor proteins to the cornified cell envelope expressed late in epidermal differentiation. Involucrin expression starts in the upper spinous layers in normal human epidermis and precedes loricrin expression, which is restricted to the granular layer. Subsequently, both proteins become cross-linked by the activity of transglutaminases TGK/E as major components of the cornified cell envelope by N epsilon-(gamma-glutamyl)lysine isopeptide bonds. In this study, three cases of lamellar ichthyosis were analyzed by immunohistologic study with antibodies to loricrin, involucrin, filaggrin, and transglutaminase TGK. OBSERVATIONS: A high expression of loricrin and involucrin with a peculiar and abnormal cytoplasmic staining concurred with a diminished cytoplasmic staining of transglutaminase TGK as assessed by antibodies B.C.1 and K.D.3. This pattern was absent in a collodion baby at birth but present 2 weeks later before a phenotype of lamellar ichthyosis appeared clinically. CONCLUSIONS: The results suggest that in our cases of lamellar ichthyosis, (1) disturbed membrane anchorage of transglutaminase TGK could alter loricrin and involucrin cross-linkage and the formation of the cornified cell envelope and that (2) immunohistologic study might serve as an early diagnostic and prognostic tool in the treatment of collodion babies.

Cell Membrane↗
PubMed1992

Mutations in the rod domains of keratins 1 and 10 in epidermolytic hyperkeratosis.

Epidermolytic hyperkeratosis is a hereditary skin disorder characterized by blistering and a marked thickening of the stratum corneum. In one family, affected individuals exhibited a mutation in the highly conserved carboxyl terminal of the rod domain of keratin 1. In two other families, affected individuals had mutations in the highly conserved amino terminal of the rod domain of keratin 10. Structural analysis of these mutations predicts that heterodimer formation would be unaffected, although filament assembly and elongation would be severely compromised. These data imply that an intact keratin intermediate filament network is required for the maintenance of both cellular and tissue integrity.

Amino Acid Sequence↗
PubMed1992

Endogenous glutathione levels modulate the frequency of both spontaneous and long wavelength ultraviolet induced mutations in human cells.

Spontaneous and induced mutations at the hypoxanthine guanine phosphoribosyl transferase locus have been measured in cultured human lymphoblastoid (TK6) cell populations under conditions in which cellular glutathione has been severely depleted by overnight treatment with buthionine-S,R-sulfoximine. At maximum levels of glutathione depletion, the increase in spontaneous frequency is at least 5-fold, a finding consistent with the possibility that cellular redox state can modulate the levels of pre-mutagenic damage arising as a result of normal metabolism in cultured human cells. Glutathione depletion does not lead to a significant enhancement in the frequency of mutants that arise as a result of irradiation at 313 nm but does lead to a 3-fold increase in mutations resulting from irradiation at 365 nm. These results indicate that glutathione may quench reactive intermediates that would otherwise lead to spontaneous mutations as well as a fraction of UVA radiation-induced premutagenic damage.

Buthionine Sulfoximine↗
PubMed1992

Relationship between melanogenesis, glutathione levels and melphalan toxicity in human melanoma cells.

Resistance to alkylating agents has been correlated with cellular levels of reduced glutathione (GSH) and glutathione-S-transferase (GST). GSH is also involved in regulation of melanin synthesis. Therefore, we examined sensitivity to melphalan as a function of differentiation and GSH/GST levels in three human melanoma cell lines. The Me8 cell line, classified as undifferentiated on the basis of cell shape, absence of pigment, insignificant dopa oxidase activity and presence of inhibitors of dopa-melanin formation, showed the lowest GST activity among the cell lines investigated. GLL19 cells exhibited normal differentiation as indicated by the presence of dendrites, typical eumelanosomes, melanin granules and dopa oxidase activity. These cells showed the highest GSH content and the highest GST activity. The JUSO cell line showed incomplete differentiation, and its dopa oxidase and GST activities were intermediate between the Me8 and GLL19 cell lines. The sensitivity of melanoma cell lines to melphalan increased with their degree of differentiation; it was lowest for Me8, intermediate for JUSO and highest for GLL19. Dibutyryl cyclic AMP (dbcAMP) enhanced melphalan toxicity against Me8 cells. Depletion of intracellular GSH with buthionine sulphoximine (BSO) resulted in a three-fold increase in melphalan sensitivity in all three cell lines. Our results indicate that melphalan toxicity is related to cell differentiation and GSH status of melanoma cells. Based on the observed relationship between dopa oxidase, GSH/GST levels and drug toxicity, it is proposed that competition for the GSH pool between quinonoid melanin intermediates and melphalan could diminish drug conjugation and increase cytotoxicity.

Bucladesine↗
PubMed1992

Self-healing collodion baby: evidence for autosomal recessive inheritance.

Five spontaneously healing collodion babies were recorded in a large Swiss kindred. They all had consanguineous parents. Their distribution in the family indicates autosomal recessive inheritance. At birth they had the typical features of collodion babies. The collodion-like membrane was shed within the first month, leaving a slightly scaly skin for a few weeks. Thereafter the skin remained normal without any evidence of a disorder of cornification.

Child↗
PubMed1992

A comparative study of formaldehyde detection using chromotropic acid, acetylacetone and HPLC in cosmetics and household cleaning products.

Chromotropic acid and acetylacetone methods for qualitative determination of formaldehyde were tested in parallel on 48 commercial samples, with high-performance liquid chromotography (HPLC) implemented for quantitative measure. In addition, interference with the detection of formaldehyde was investigated by analyzing 12 other aldehydes and ketones, 7 essential oils and 3 polysorbates. Throughout this comparative study, the disadvantages of the chromotropic acid method, of which 2 variants were used, were delineated and we found that the acetylacetone test proved to be a more efficient screening method for formaldehyde detection in a clinical laboratory.

Chromatography, High Pressure Liquid↗
PubMed1992

[Eccrine syringofibroadenoma. Report of clinical aspects and histology of two cases with review of the literature].

Eccrine syringofibroadenoma is a rare benign neoplasm with differentiation towards eccrine ducts. Its recognition depends on the histopathological examination; it is to be differentiated mainly from fibroepithelial basal cell carcinoma. Two new cases which occurred in a 70-year-old woman and a 39-year-old woman are presented. Clinically the two neoplasms were each a solitary hyperkeratotic, partially oozing nodule. On microscopic examination they both showed proliferation of small neoplastic cells in a reticular pattern; immature or mature eccrine ductal structures were seen within them. The neoplastic cells in the two cases differed in their content of PAS-positive glycogen.

Adenoma, Sweat Gland↗
PubMed1992

[Erythema nodosum and AIDS].

We report on a patient with AIDS who developed erythema nodosum, an association that has not previously been reported. Extensive clinical and laboratory investigations disclosed no obvious origin of erythema nodosum apart from HIV infection with disseminated Kaposi sarcoma.

Acquired Immunodeficiency Syndrome↗