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Biomedical subjects

L Carr

Publications and source records attributed to L Carr.

At least 55 records · Page 3Linked to original sources
PubMed1989

Tryptic cleavage as a probe of conformational differences between active and inactive forms of ornithine aminotransferase.

Treatment of ornithine aminotransferase with trypsin resulted in rapid and complete loss of enzyme activity in a process that coincided with a reduction in subunit Mr of about 3000. However, electrophoresis showed that a substantial proportion of the enzyme had not been digested. The component of the preparation of ornithine aminotransferase that was insusceptible to trypsin contained a naturally occurring but enzymically inactive form of the enzyme, and when this had been removed, the remaining fully active enzyme was completely digested. Irreversible inactivation with a substrate analogue made all of the enzyme insusceptible to trypsin. The hydrolyzed enzyme still underwent a very slow half-reaction with ornithine. Sequence analysis of the truncated protein, prepared by blotting from electrophoretic gels, showed that hydrolysis had occurred at peptide bond Lys26-Tyr27.

Amino Acid Sequence↗
PubMed1986

Crossed fused renal ectopia: sonographic diagnosis.

Five cases of crossed fused renal ectopia, all confirmed by either computed tomographic scan or intravenous urography, were diagnosed sonographically. The sonographic appearance of this entity consists of a characteristic anterior and/or posterior notch, difference in orientation of the 2 collecting systems in the fused kidneys, and absence of a kidney in the contralateral renal fossa, or elsewhere in the body, such as the pelvis. The inability to diagnose this condition correctly may lead to the misdiagnosis of a renal mass or infiltrative disease occupying the contralateral renal fossa. Computed tomographic scans will also identify the anomaly.

Adult↗
PubMed1986

Intradecidual sign: a US criterion of early intrauterine pregnancy.

The uterine cavity appears on sonograms as a linear echo, which is usually visible during early pregnancy and remains straight until the eighth to ninth week of gestation. The early gestational sac is not enveloped by two layers of decidua, as suggested by descriptions of the double decidual sac sign; the sac (or echogenic area of early implantation) is actually located within a markedly thickened decidua on one side of the uterine cavity. The combination of these two sonographic characteristics is called the "intradecidual sign." An early implantation of 25 days gestational age can be detected by the presence of the intradecidual sign, which is sooner than a gestational sac can be seen. The implantation site can also be located by means of the intradecidual sign. In a study of 36 patients with early intrauterine pregnancy and five with ectopic pregnancy, the intradecidual sign was more sensitive (91.7% vs. 63.9%) and specific (100% vs. 60%) than the double decidual sac sign in the detection of early intrauterine pregnancy.

Female↗
PubMed1985

Hyperprolactinemia and estrogen-induced rhythms in LH and prolactin release in the ovariectomized rat.

Short-term (9 days) hyperprolactinemia induced by pituitary grafts reduced basal plasma LH levels in ovariectomized rats whereas long-term (31 days) grafts increased basal LH levels. Although long-term grafts inhibited estradiol-induced prolactin surges, hyperprolactinemia had no effect on the LH surge. It is concluded that the estrogen-treated ovariectomized rat is not suitable for studying the effects of hyperprolactinemia on LH release.

Animals↗
PubMed1985

Testicular lymphoma: sonographic findings.

The sonographic findings in 2 patients diagnosed as having testicular lymphoma (subsequently surgically proven) are discussed. The diagnosis should be suspected when a hypoechoic mass is identified in the testicle.

Adult↗
PubMed1985

An experimental comparison of vertical tooth movement of 33 degrees and 0 degree teeth after denture processing procedures.

Movement of teeth during denture processing is an unsolved problem. This study investigates the amount of vertical tooth movement during controlled processing of acrylic, using 33 degrees and 0 degree teeth invested in specific mixes of plaster of Paris or dental stone. Forty sample set-ups each containing four posterior teeth were processed under strictly controlled laboratory conditions. Twenty of these samples carried 33 degrees teeth and the other twenty carried 0 degree teeth. Each group of twenty samples was randomly divided on a factorial design into batches of ten for investment in plaster of Paris or stone. The vertical movements were measured with a greater degree of accuracy than is required for clinical application. All results were analysed statistically. Significantly greater movement occurred with teeth invested in stone than those invested in plaster of Paris. Whereas, for teeth invested in stone, significantly greater movement occurred with 33 degrees than with 0 degree teeth, no such effect was found with teeth invested in plaster of Paris.

Calcium Sulfate↗
PubMed1984

Low-dose aminoglutethimide in treatment of advanced breast cancer.

The clinical and endocrine effects of low-dose aminoglutethimide without hydrocortisone in patients with advanced breast cancer were investigated. In a dose escalation study low-dose aminoglutethimide alone (62.5-125 mg twice daily) was as effective as conventional doses with hydrocortisone in lowering serum oestrone and oestradiol concentrations but caused minimum adrenal inhibition, as assessed by serum dehydroepiandrosterone sulphate. 11 of 57 (19%) evaluable patients had tumour regression by objective criteria on this treatment, but the frequency of side-effects was similar to that with conventional doses. Low-dose aminoglutethimide is active in the treatment of breast cancer. It appears to work by inhibition of the aromatase enzyme system in peripheral tissues rather than adrenal suppression.

Adrenal Glands↗