Search PubMed⌕ Search

Biomedical subjects

A Jacob

Publications and source records attributed to A Jacob.

144 records · Page 8Linked to original sources
PubMedDate not supplied

Comparison of visual estimate with digital caliper measurement of coronary artery stenosis.

We compared visual estimate and digital caliper measurement of coronary stenoses, utilizing both a 50% and 70% diameter reduction as a definition of significance and both experienced angiographers and cardiology fellows as readers. Ten angiograms were interpreted twice, using the different methods, by four readers, two months apart. The angiograms were divided into 12 vessel segments. Stenoses were judged more severe by visual estimate in 11 segments. Seven of twelve segments had significant differences between readers using the visual estimate, but no significant differences were obtained using caliper measurements. Variability was highest for fellows using the visual method. Interobserver agreement was highest using the digital caliper and the 70% criteria. Intraobserver agreement was most dependent on the amount of time taken in film interpretation. The digital caliper appears to be preferable in interpreting angiograms, particularly for cardiology fellows.

Coronary Angiography↗
PubMedDate not supplied

Male infertility and environmental exposure to lead and cadmium.

Humans are exposed occupationally and environmentally to metal aerosols including lead (Pb2+) and cadmium (Cd2+). These toxicants accumulate in male reproductive organs. Epidemiological studies have been equivocal about effects of Pb2+ and Cd2+ on hormone concentrations, male fertility and sperm parameters. Comparison of Pb2+ and Cd2+ concentrations in fertile and infertile men are problematic. Problem areas include failure to control confounding variables, but genetic polymorphisms as in somatic diseases may modulate Pb2+ and Cd2+ damage. Multiple calcium (Ca2+) and potassium (K+) channel isoforms have been identified in human testes and spermatozoa. These Ca2+ and K+ channels are involved in early events of acrosome reactions. Ca2+ channel are susceptible to Cd2+ poisoning and K+ channels to Pb2+. These channels offer entry paths for metallic toxicants into mature spermatozoa. Ion channel polymorphisms may cause differential sensitivities to Cd2+ and Pb2+, explaining in part prospective blinded studies showing high Cd2+ in varicocele-related human infertility and high Pb2+ in unexplained infertility. In both forms of male infertility the ability to undergo an acrosome reaction decreases. Reverse transcriptase-polymerase chain reaction assays for Ca2+ and K+ channel isoforms may identify susceptibility subgroups with lower resistance to environmental exposures.

Cadmium↗
PubMedDate not supplied

Biochemical and functional analysis of nuclear receptors as targets in cAMP-dependent control of bovine CYP17.

Several lines of evidence have suggested that the nuclear receptor Steroidogenic Factor-1 (SF-1 or Ad4BP) may be directly involved in the cAMP-dependent regulation of steroid hydroxylase genes in adrenocortical cells. In the bovine CYP17 gene, which encodes the cytochrome P450 17alpha-hydroxylase, an SF-1 site is present within cAMP-responsive sequence 2 (CRS2) and mutations which interfere with SF-1 binding correlate with decreases in cAMP-stimulated transcription of a linked reporter gene. In order to determine whether the cAMP response relies on structures within SF-1 itself, mutations and deletions were introduced. We demonstrate that even a single point mutation (E454A) in the transactivating AF-2 domain drastically reduces the ability of SF-1 to mediate cAMP-dependent transcription. Furthermore, the mutation results in a protein which acts in a dominant negative fashion with respect to cAMP-dependent regulation of the bovine CYP17 gene. Finally, we demonstrate that the coactivators CBP and SRC-1 are limiting with respect to cAMP-induced CRS2-dependent transcription in Y1 adrenocortical tumor cells, suggesting that part of the action of cAMP may be to influence the interaction of SF-1 with other cofactors via the AF-2 domain.

Adrenal Cortex Neoplasms↗
PubMedDate not supplied

Serologic evidence of human monocytic and granulocytic ehrlichiosis in Israel.

We conducted a retrospective serosurvey of 1,000 persons in Israel who had fever of undetermined cause to look for Ehrlichia chaffeensis antibodies. Four of five cases with antibodies reactive to E. chaffeensis were diagnosed in the summer, when ticks are more active. All patients had influenzalike symptoms with high fever. None of the cases was fatal. Three serum samples were also seroreactive for antibodies to E. canis, and one was also reactive to the human granulocytic ehrlichiosis (HGE) agent. The titer to the HGE agent in this patient was higher than the serum titer to E. chaffeensis, and the Western blot analysis also indicated that the HGE agent was the primary cause of infection. We present the first serologic evidence that the agents of human monocytic ehrlichiosis (HME) and HGE are present in Israel. Therefore, human ehrlichiosis should be included in the differential diagnoses for persons in Israel who have been exposed to ticks and have influenzalike symptoms.

Adult↗
PubMedDate not supplied

[Blunt injury of the larynx by hanging. X-ray computed tomographic aspect].

The closed laryngeal traumas by attempt of hanging are rarely studied by medical imaging. The lesions are evaluated by fiberoptic endoscopy and CT scan. We report a case of complicated lesions of the larynx with rupture of the cricothyroid membrane, diagnosed by CT scan and we discuss the usefulness of this technique.

Adult↗