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Biomedical subjects

V P Sybert

Publications and source records attributed to V P Sybert.

At least 55 records · Page 3Linked to original sources
PubMed1990

Heterogeneity in harlequin ichthyosis, an inborn error of epidermal keratinization: variable morphology and structural protein expression and a defect in lamellar granules.

Skin biopsies and scale samples from nine infants and one fetus affected with harlequin ichthyosis (HI) were obtained from eight families. Epidermal differentiation was examined by morphologic and biochemical criteria and cell culture studies. Two striking abnormalities were identified; first, keratin and filaggrin expression were abnormal and varied between cases, and, second, in all cases lamellar granules were absent or abnormal, and intercellular lamellae within the stratum corneum were absent. Three HI phenotypes were distinguished by variable expression of epidermal structural proteins. Cases were classified by the absence (type 1) or presence (types 2 and 3) of keratins K6 and K16 ("hyperproliferative" keratins) and by the presence of profilaggrin in the interfollicular epidermis (types 1 and 2 only). Profilaggrin is apparently not converted to filaggrin, but it is retained in the scale. The block in profilaggrin processing may be due to an inactive phosphatase. Siblings in two families (presenting with types 1 and 2) showed the same type classification suggesting that expression of the phenotype is consistent within families but differs between families. Cultured HI keratinocytes were normal by phase microscopy, but abnormal by electron microscopy with no lamellar granules and extensive stacking of the upper layers. We conclude that harlequin ichthyosis is a genetically heterogeneous group of disorders with altered lamellar granules, intercellular lipids, and variation in expression and/or processing of structural protein markers of normal epidermal keratinization. Furthermore, the lamellar granule and structural protein defects may be indirectly related via a mechanism involving phosphorylation/dephosphorylation.

Biopsy↗
PubMed1990

Intra-epidermal retention of type VII collagen in a patient with recessive dystrophic epidermolysis bullosa.

An infant born with severe blisters on the limbs, face, trunk, and oral mucosa was diagnosed by light and electron microscopy to have recessive dystrophic epidermolysis bullosa. Transmission electron microscopy showed that the basal lamina remained with the epidermis and that the floor of the blister was exposed collagen of the papillary dermis. No banded anchoring fibrils were observed along either the roof or the floor of the blister; however, small filamentous structures, possibly immature anchoring fibrils, extended down from the lamina densa along the blister roof. Some basal and suprabasal keratinocytes contained large vesicles filled with filamentous matrix of variable electron density. Immunofluorescent staining of skin for type VII collagen showed sparse and irregular staining of type VII collagen along the blister roof, and intense intracellular labeling for type VII collagen in clusters of epidermal cells in basal and suprabasal layers. Type VII collagen appeared to be synthesized by keratinocytes but not secreted.

Antibodies, Monoclonal↗
PubMed1989

Cutaneous and extracutaneous neutrophilic infiltrates (Sweet syndrome) in three patients with Fanconi anemia.

Three patients with coexistent Fanconi syndrome and Sweet syndrome (neutrophilic dermatosis) are presented. These sterile skin lesions responded to systemic corticosteroid therapy in all three cases, and recurred when treatment was discontinued. The association in children of Sweet syndrome with malignancy has previously been recognized; it has not been reported in the premalignant phase of Fanconi anemia. This report expands the differential diagnosis of the neutrophilic dermatoses. Children with Sweet syndrome and anemia should be examined for Fanconi anemia by diepoxybutane cytogenetic studies.

Adult↗
PubMed1989

Congenital monocytic leukemia: report of a case with cutaneous involvement, and review of the literature.

Congenital leukemia is a rare disease that can become manifest soon after birth. Cutaneous involvement consists of red, brown, or purple papules and nodules, and confluent areas of purpura. The diagnosis is established by the presence of leukemic cells in biopsy specimens of bone marrow and involved skin, and by immunocytochemical characterization of these cells. We report a case of congenital monocytic leukemia with a normal karyotype, whose disease underwent temporary spontaneous regression.

Humans↗
PubMed1989

Hypohidrotic ectodermal dysplasia: argument against an autosomal recessive form clinically indistinguishable from X-linked hypohidrotic ectodermal dysplasia (Christ-Siemens-Touraine syndrome)

Hypohidrotic ectodermal dysplasia (HED) is a well-described, X-linked recessive disorder characterized by hypohidrosis, hypodontia, and hypotrichosis in males. Reports of similarly affected females have suggested autosomal recessive inheritance in some families. The evidence for two clinically identical but genetically distinct disorders is not convincing, however. In two families with X-linked recessive inheritance of HED, the condition was severe in females. A critical review of previously reported cases of presumed autosomal recessive HED suggests that an autosomal recessive form of the condition identical to the X-linked HED may not exist. All sporadic instances of females with classic HED should be considered to be X-linked recessive, and counseling for X-linked recessive inheritance as well as autosomal recessive inheritance should be given.

Anodontia↗
PubMed1988

Idiopathic extrahepatic biliary atresia: recurrence in sibs in two families.

Since 1855, 11 instances of familial extrahepatic biliary atresia (EHBA) have been described. Genetic, environmental, vascular, and infectious causes for this disorder have been proposed. We report on 2 families each with 2 sibs with EHBA. We suggest that a genetic susceptibility to an environmental insult to the biliary tree may be responsible for the genesis of this disease.

Biliary Atresia↗
PubMed1988

Mosaicism for ring 19: a case report.

A male with mosaicism for ring 19 presented with a complex cardiac malformation, microcephaly and minor dysmorphic features. Intellectual development has been within normal limits. This chromosome aberration has been reported only twice before and no clear phenotype-karyotype correlations are recognized.

Abnormalities, Multiple↗
PubMed1988

Palmar-plantar keratoderma. A clinical, ultrastructural, and biochemical study.

The hereditary palmar-plantar keratodermas are a heterogeneous group of disorders characterized by hyperkeratosis of the palms and soles and distinguishable by other clinical characteristics, associated abnormalities, and mode of inheritance. We report a family with a new autosomal dominant condition with clinical similarities to mal de Meleda and Greither's disease. Biochemical characteristics before and during treatment with oral isotretinoin were typical of hyperproliferative epithelium with expression of the 48-kd keratin. Ultrastructural abnormalities were qualitatively reduced during treatment, but the abnormal keratohyaline aggregations were still seen. Clinical improvement with treatment was marked and directly correlated with dosage.

Adult↗
PubMed1987

Rapp-Hodgkin ectodermal dysplasia.

Rapp-Hodgkin ectodermal dysplasia is an autosomal dominant condition characterized by distinctive craniofacies, cleft lip or palate, dental hypoplasia with caries, dystrophic nails, and decreased to absent sweat glands and hair follicles. We report the third family to be described, and distinguish the condition from similar syndromes.

Ectodermal Dysplasia↗
PubMed1987

Keratinocytes cultured from subjects with ichthyosis vulgaris are phenotypically abnormal.

Ichthyosis vulgaris (IV) is an autosomal dominant, scaling disorder in which keratohyaline granules and filaggrin are reduced in or absent from the epidermis of affected individuals. Morphologic and biochemical markers of epidermal differentiation were studied in keratinocytes cultured from clinically unaffected skin of patients with IV, from clinically unaffected skin of an obligate gene carrier, and from normal skin of unaffected family members and an adult volunteer. Cultured keratinocytes from affected subjects formed thickened layers of scaly cells that failed to react with monoclonal antibody to filaggrin. In contrast, normal cells contained many large, immunoreactive granules. Electron microscopy confirmed the absence of keratohyaline granules in affected cells and the presence of large keratohyaline granules in normal cells. Immunoblot analysis of keratinocyte extracts from subjects with ichthyosis showed that profilaggrin was absent, but no differences in keratins were detected between affected and control cells. For all parameters, findings in cells of the clinically unaffected obligate gene carrier were intermediate between those from affected patients and controls. We conclude that keratinocytes cultured from patients with IV maintain structural and biochemical phenotypic characteristics of the disease in vitro.

Biopsy↗
PubMed1987

Prenatal diagnosis and screening.

We have limited the scope of this article to those disorders that have already been successfully diagnosed or excluded in utero. We currently have the potential to diagnose a number of others for which the opportunity has not yet arisen. If a biochemical, morphologic, chromosomal, or DNA alteration is known for a specific condition and is likely to be expressed in one of the fetal tissues or secretions, attempt at prenatal diagnosis is reasonable. Our ability to detect the inherited disorders of the skin in utero will continue to improve both in the number of specific disorders successfully diagnosed or excluded and in the increasingly earlier stages of pregnancy at which the disorder can be detected. Advances in instrumentation will, it is hoped, decrease the risk of the invasive methods of prenatal diagnosis, and improvement in noninvasive methods, such as maternal serum screening, may eliminate the need for invasive procedures altogether. Detection of useful DNA polymorphisms linked to genes for specific genodermatoses and development of specific gene probes will improve the accuracy of diagnosis and reduce the need for specific fetal tissues. The entire genome of an individual is present in each cell, even though a specific gene product may not be expressed in that cell. Thus, DNA restriction endonuclease studies can be performed on amniotic fluid cells, chorionic villi, fetal cells in maternal circulation, and fetal tissues with equal facility. The usefulness of prenatal diagnosis will always be limited by the ability to detect pregnancies at risk. If carrier detection is unavailable, the only way to identify couples at risk for offspring with an autosomal recessive condition is by the birth of an affected child. For autosomal dominant and X-linked recessive and dominant conditions, new mutations will continue to occur. As mentioned previously, screening of all pregnancies for all defects is not possible now and is unlikely ever to be feasible, either economically or technically. The reliability of prenatal diagnosis will continue to depend upon accurate diagnosis in the index case and upon the availability of a specific and sensitive test (or tests), with no overlap in values between heterozygotes and homozygotes for autosomal recessive conditions or between normal and affected fetuses with autosomal dominant and X-linked recessive disorders. Correct interpretation of test results is subject to experience, recognition of artifact, and variation in the expression of a given disorder in utero.(ABSTRACT TRUNCATED AT 400 WORDS)

Amniocentesis↗
PubMed1986

Psychosocial adjustment of adult women with Turner syndrome.

This paper presents results from a detailed assessment of the psycho-social adaptation of a group of adult women with Turner syndrome. Thirty subjects, 21 to 48 years of age, participated in an evaluation of social and psychiatric status. The evaluation included a semi-structured interview designed to assess current social functioning and past psychiatric and social history. Subjects completed two self-report questionnaires as well: the Tennessee Self-Concept Scale and the Carroll Rating Scale for Depression. The results reveal a significant subgroup of subjects reporting major psychiatric difficulties and endorsing a considerably impaired sense of self-esteem. These women presented as very dissatisfied with themselves and their lives. These findings are not consistent with previous reports in which women with Turner syndrome have been described as having an unusually high tolerance for stress and being emotionally inert.

Adaptation, Psychological↗
PubMed1986

Measurement of body fat in Turner syndrome.

Fourteen individuals with the Turner syndrome (gonadal dysgenesis with X chromosome chromosome abnormalities) were evaluated for obesity using hydrostatic weighing and skinfold measurements. While skinfold estimates of body fat correlated well with clinical impression, hydrostatic weighing appeared to falsely overestimate percent body fat. We suggest that reduced skeletal mass and/or occult lymphedema in Turner syndrome may invalidate the formula used to calculate percent body fat derived from hydrostatic weights. In this population and possibly in other disorders where skeletal mass is reduced from the normal, the use of hydrostatic weighing may be inappropriate.

Adult↗