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Biomedical subjects

S Taylor

Publications and source records attributed to S Taylor.

At least 433 records · Page 24Linked to original sources
PubMed1982

Amphibian neurotensin (NT) is not xenopsin (XP): dual presence of NT-like and XP-like peptides in various amphibia.

To clarify whether xenopsin (XP) is the amphibian counterpart of mammalian neurotensin (NT), extracts of skin, brain, and intestine from representative amphibians were subjected to immunochemical, chromatographic, and biological analyses. The results indicated the dual presence of NT- and XP-like peptides in extracts of tissues from Xenopus laevis, Rana catesbeiana, Rana pipiens, Bufo marinus, Bufo americanus, and Necturus maculosus, which were separated during gel chromatography on Sephadex G-25 and high pressure liquid chromatography on mu-Bondapak C-18. Immunochemical studies, employing three different region-specific antisera toward NT (ox and man) and one antiserum towards XP (Xenopus laevis), indicated that the NT-like peptides shared COOH-terminal homologies with NT and differed at their NH2-termini. TWo classes of NT-like peptides could be distinguished on the basis of their distributions in tissues and their cross-reactivities with the antisera; immunoreactive NT measured using antiserum HC-8 tended to be found primarily in brain and intestine, whereas that reactive with antiserum PGL-4 was most concentrated in stomach, liver, and pancreas. Although also present in brain and intestine, immunoreactive XP was highest in stomach, pancreas, and skin. Partially purified immunoreactive NT and XP obtained from gastrointestinal tissues of Xenopus laevis and Bufo marinus were shown to increase the hematocrit and induce cyanosis in anesthesized rats. These findings indicate the presence of both NT- and XP-like peptides in neural and gastrointestinal tissues from several amphibia and suggest the possibility that XP-like peptides (apart from NT) may exist in other animals.

Amphibians↗
PubMed1982

The petrous temporal bone (including the cerebellopontine angle).

Lower resolution CT scanners play an important role in the evaluation of the cerebellopontine angle, but careful integration along with the older conventional examinations is often necessary. A high-resolution CT scanner may provide all the necessary information. With proper techniques, bony changes are most clearly analyzed, and small tumors of the acoustic nerve may be directly seen in the cerebellopontine angle, and even in the internal auditory canal, with only a contrast-enhanced scan. If necessary CT-air cisternography provides the most sensitive and least morbid of the definitive, invasive examinations. In scanning only a localized region, care must be taken not to overlook abnormalities just beyond the immediate cerebellopontine angle, either within the posterior fossa or the petrous temporal bone.

Cerebellopontine Angle↗
PubMed1981

Clinical kinetics on intact cisplatin and some related species.

Plasma concentrations of cisplatin, total platinum, and total filterable platinum were monitored in 24 patients after either 50 or 100 mg/m2 of cisplatin by rapid intravenous injection. Half the patients at each dose were pretreated with mannitol. Total platinum levels declined in a triphasic fashion with a terminal half-life (t1/2)greater than or equal to 24 hr. Both total filterable platinum and cisplatin levels declined in a monophasic manner and exhibited t1/2 of 0.3 to 0.5 hr. The ratio of cisplatin to total filterable platinum in plasma remained constant (0.6 to 0.8) over the time period (2 hr) during which they could be detected, while the ratio of the plasma levels of cisplatin to total platinum decreased continuously from approximately 0.5 at 5 min to approximately 0.10 at 2 hr. Larger doses of cisplatin resulted in higher plasma levels of all three species monitored, and although the increases appeared somewhat less than proportional to dose, terminal plasma slopes were not dose dependent. Neither mannitol nor dose had an effect on the various species ratios, nor did mannitol appear to affect either plasma levels or terminal plasma decline.

Cisplatin↗
PubMed1981

The effect of bromocriptine on insulin secretion and glucose tolerance in patients with acromegaly.

The oral administration of bromocriptine 5 mg 6-hourly to twelve patients with acromegaly for a mean period of 12 (range 3-27) months significantly reduced whole blood glucose, plasma insulin and plasma growth hormone (GH) concentrations during a 50 g oral glucose tolerance test (OGTT). After this period of treatment, bromocriptine was withdrawn for 48 h resulting in a significant rise in whole blood glucose, plasma insulin and plasma GH concentrations during a repeat OGTT. It is concluded that bromocriptine therapy improves glucose tolerance in acromegaly by suppressing GH secretion and consequently GH-mediated antagonism of insulin.

Acromegaly↗
PubMed1980

Phase I evaluation of chlorozotocin: single dose every six weeks.

A phase I trial of chlorozotocin was completed for the single dose every six week schedule. At 250 mg/m2 i.v. push, excessive thrombocytopenia, nausea, and anorexia occurred. Two cases of cholestatic jaundice were seen, and one patient had worsening of his diabetes mellitus after one course. Partial response or prolonged disease stabilization with increased survival was documented in four of seven patients with non-small cell carcinoma of the lung. A starting dose of 225 mg/m2 is recommended for good risk patients with little or no prior bone marrow toxicity from chemotherapy or irradiation. A dose of 200 mg/m2 is recommended for patients with limited previous treatment and good bone marrow reserve.

Anorexia↗
PubMed1980

Studies of hydroxyurea administered by continuous infusion: toxicity, pharmacokinetics, and cell synchronization.

Hydroxyurea was administered by means of two schedules designed to provide continuous 72-hour exposure of tumor cells to therapeutic drug levels. Toxicity and pharmacokinetics were determined for both an oral pulse dose schedule (every 4 hours x 18 doses) and continuous intravenous (IV) infusion for 72 hours. The maximal tolerated dose (MTD) was 800 mg/m2 every 4 hours for the oral route and 3.0 mg/m2/min x 72 hours for IV infusion. Granulocytopenia was dose-limiting for both schedules and correlated well with plasma-HU levels. Serial sampling of normal bone marrow (10 patients) and tumor tissue (3 patients) showed a modest degree of synchronization induced by continuous IV infusion of hydroxyurea. Interindividual pharmacokinetic variations severely limit the usefulness of the oral pulse schedule as a potential means of synchronizing cells. Hydroxyurea administered by continuous IV infusion may be useful as a synchronizing agent in humans.

Administration, Oral↗
PubMed1980

Pituitary apoplexy. The importance of skull roentgenograms and computerized tomography in diagnosis.

In two patients with pituitary apoplexy, computerized tomograms demonstrated a suprasellar mass that, after infusion with contrast medium, showed a peripheral ring-like enhancement consistent with a pituitary adenoma with central necrosis. In patients with symptoms or signs suggesting subarachnoid hemorrhage or meningitis, the finding of an enlarged sella turcica on plain skull roentgenograms should raise the possibility of pituitary apoplexy. This diagnosis may be rapidly and safely confirmed by computerized tomography.

Adult↗