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Biomedical subjects

D Benjamin

Publications and source records attributed to D Benjamin.

At least 109 records · Page 6Linked to original sources
PubMed1995

Muscle X-inactivation patterns and dystrophin expression in Duchenne muscular dystrophy carriers.

Muscle pathology, dystrophin expression and X-inactivation patterns were studied in the muscle of five asymptomatic females heterozygous for deletions in the dystrophin gene (non-manifesting carriers) and five symptomatic carriers (manifesting carriers). Muscle from the non-manifesting carriers showed an increase in the population of centrally nucleated fibres (9.0 +/- 2.8%; controls, 1.4 +/- 0.3%), frequent fibers with abnormally interrupted dystrophin staining (38 +/- 5%), and, in sections from three individuals, small numbers of dystrophin-negative fibers (1-4%). The amount of dystrophin measured by immunoblotting was reduced to 64 +/- 5% (P < 0.001 n = 5) of normal. The pattern of X-inactivation in muscle DNA was non-biased (50: 50-60: 40) in all cases. In the manifesting carriers both highly biased (90: 10) and non-biased patterns of X-inactivation were found, but no consistent relationship was apparent between the patterns of X-inactivation and the proportions of dystrophin-negative fibers. We conclude from studies of the non-manifesting carriers that the proportion of residual dystrophin is similar to the relative activation in muscle of the X-chromosome carrying the wild-type allele. Extreme bias of X-inactivation can be associated with early clinical symptoms and severe pathology. However, as non-manifesting and some manifesting adult carriers had identical patterns of X-inactivation, abnormalities in the distribution of dystrophin, as well as overall levels of expression, may be important for the development of myopathic pathology.

Adolescent↗
PubMed1995

Electrovaporization of the prostate: new technique for treatment of symptomatic benign hyperplasia.

This pilot study evaluated the efficacy of a newly configured roller electrode (Circon/ACMI Vaportrode) in the treatment of symptomatic benign prostatic hyperplasia. The electrode is used with a cutting current and an otherwise-standard (ACMI) resectoscope. Thirty-four patients with significant symptoms of bladder outlet obstruction were treated and evaluated. Among them, 20 were in urinary retention, and 14 had moderate to severely symptomatic bladder outlet obstruction. Thirty-three patients are voiding and available for follow-up. The other patient has not returned. All available patients have shown both subjective and objective voiding improvement. In the evaluable patients, the AUA Symptom Index decreased from a mean of 26 to 12. The mean postoperative peak urinary flow rate was 13 mL/sec. Complications occurred in three patients (post-operative bleeding in one, urinary retention in two). Electrovaporization allowed definitive treatment of bladder outlet obstruction with subjectively better visibility than transurethral resection (TURP). The potential for fluid and electrolyte shifts and resulting complications appears to be less than with TURP. Further study of this technique appears warranted.

Aged↗
PubMed1994

B cell IL-7. Human B cell lines constitutively secrete IL-7 and express IL-7 receptors.

IL-7 was originally reported as a cytokine produced by stromal cells which supports pre-B cell proliferation in vitro. To determine whether human B cells secrete IL-7 and express IL-7R we studied a wide panel of B cell lines (CLS). In Northern blot analysis we detected 2.4 kb IL-7 mRNA and by quantitative PCR we demonstrated IL-7 expression in 5 of 6 B CLS derived from patients with AIDS-associated Burkitt's lymphoma (AABCL), 3 of 3 CLS derived from patients with American Burkitt's lymphoma and 5 of 6 normal lymphoblastoid CLS. Only 1 of 5 African Burkitt's lymphoma CLS and 2 of 7 EBV- CLS expressed IL-7. A total of 484-bp amplicons was cloned and sequenced and found to correspond to the original IL-7 sequence. Constitutive IL-7 secretion was detected in 5 of 6 AABCL and in 6 of 7 normal lymphoblastoid CLS but in none of the 7 EBV- CLS. IL-7R expression was demonstrated in 8 of 26 CLS, none of which secreted IL-7. Our data suggest that 1) IL-7 mRNA is expressed in malignant B cell phenotypes, which correspond to a narrow window in the B cell differentiation pathway (pre-B, early B, intermediate B), as well as in normal lymphoblastoid B CLS. 2) IL-7 mRNA is expressed in both EBV+ and EBV- CLS, but only the EBV+ CLS secrete IL-7. 3) B cells activated by both EBV and HIV-1 (AABCL) secrete the greatest amount of IL-7. 4) IL-7 autocrine loops are not evident since IL-7R were detected on on CLS, which do not secrete IL-7. Our data provide the first direct evidence of IL-7 secretion by human cells and it is yet to be determined whether IL-7 is secreted by other cell types.

B-Lymphocytes↗