Biomedical subjects

T Jaffe

Publications and source records attributed to T Jaffe.

5 recordsLinked to original sources

PubMed1997

Diagnosis of postoperative urinary ascites using renal scintigraphy.

Nuclear medicine biliary studies have been routinely used to identify bile leaks that occur after laparoscopic cholecystecomy. The use of a Tc-99m mercaptoacetyltriglycine (MAG3) renal scan to diagnose a case of urinary leakage that occurred after a laparoscopic-assisted colectomy is shown in this report. Laparoscopic surgery is widely used in place of conventional laparotomy to minimize recovery time and discomfort after surgery. The complication rate for laparoscopic colectomy has been reported as approximately 6% to 10%. In particular, ureteral leak has been reported in 2% of procedures. Ascites of unknown origin can become a diagnostic dilemma. We present a case of postoperative ascites of unknown origin that was successfully diagnosed as urinary leakage using renal scintigraphy.

Ascitic Fluid↗

PubMed1996

Mouse autosomal homolog of DAZ, a candidate male sterility gene in humans, is expressed in male germ cells before and after puberty.

Deletion of the Azoospermia Factor (AZF) region of the human Y chromosome results in spermatogenic failure. While the identity of the critical missing gene has yet to be established, a strong candidate is the putative RNA-binding protein DAZ (Deleted in Azoospermia). Here we describe the mouse homolog of DAZ. Unlike human DAZ, which is Y-linked, in mouse the Dazh (DAZ homolog) gene maps to chromosome 17. Nonetheless, the predicted amino acid sequences of the gene products are quite similar, especially in their RNP/RRM (putative RNA-binding) domains, and both genes are transcribed predominantly in testes; the mouse gene is transcribed at a lower level in ovaries. Dazh transcripts were not detected in testes of mice that lack germ cells. In testes of wildtype mice, Dazh transcription is detectable 1 day after birth (when the only germ cells are prospermatogonia), increases steadily as spermatogonial stem cells appear, plateaus as the first wave of spermatogenic cells enters meiosis (10 days after birth), and is sustained at this level thereafter. This unique pattern of expression suggests that Dazh participates in differentiation, proliferation, or maintenance of germ cell founder populations before, during, and after the pubertal onset of spermatogenesis. Such functions could readily account for the diverse spermatogenic defects observed in human males with AZF deletions.

Amino Acid Sequence↗

PubMed1995

Diverse spermatogenic defects in humans caused by Y chromosome deletions encompassing a novel RNA-binding protein gene.

We have detected deletions of portions of the Y chromosome long arm in 12 of 89 men with azoospermia (no sperm in semen). No Y deletions were detected in their male relatives or in 90 other fertile males. The 12 deletions overlap, defining a region likely to contain one or more genes required for spermatogenesis (the Azoospermia Factor, AZF). Deletion of the AZF region is associated with highly variable testicular defects, ranging from complete absence of germ cells to spermatogenic arrest with occasional production of condensed spermatids. We find no evidence of YRRM genes, recently proposed as AZF candidates, in the AZF region. The region contains a single-copy gene, DAZ (Deleted in AZoospermia), which is transcribed in the adult testis and appears to encode an RNA binding protein. The possibility that DAZ is AZF should now be explored.

Amino Acid Sequence↗

PubMed1994

Genetic abnormalities and reproductive failure.

Adequate male development and spermatogenesis involve a complex array of events, all prescribed by numerous gene products in an orderly temporal and spatial sequence. A single defect in any portion of these myriad steps may lead to total failure of testicular development or simply subtle spermatogenic deficiency. As emphasis continues to be placed upon elucidation of the molecular and genetic basis underlying clinical and phenotypic human failings, knowledge will slowly accumulate to explain these failings and, it is hoped, to suggest treatment strategies for some.

Abnormalities, Multiple↗

PubMed1985

Pulsatile release of growth hormone and prolactin from the primate pituitary in vitro.

Perifused anterior hemipituitaries from one male and 4 female monkeys released GH and PRL in a pulsatile pattern, with mean +/- SE interpulse intervals of 8.2 +/- 0.4 and 8.5 +/- 0.3 min, as determined by a cycle detection computer algorithm. Mean hormone concentrations in the perifusate fractions collected at 2-min intervals were 435 +/- 89 (GH) and 515 +/- 262 (PRL) ng/ml. Pulse amplitudes averaged 74 +/- 16 ng/ml for GH and 189 +/- 89 ng/ml for PRL. These findings suggest the presence of a high frequency pulsatile secretory mechanism within the primate pituitary.

Animals↗