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Biomedical subjects

G Wright

Publications and source records attributed to G Wright.

At least 199 records · Page 11Linked to original sources

Assessment of cardiovascular function in patients undergoing coronary artery bypass grafting.

Blood pressure and flow in the ascending aorta were measured in 16 patients undergoing coronary artery bypass grafting. The analog records were digitized and the data used to compute total hemodynamic power and aortic input impedance, which may be considered to be direct indices of cardiac performance and the state of the cardiovascular system. Various indirect indices were also computed from the same data and statistically compared with the two direct indices. The results showed that it is necessary to measure both pressure and flow to achieve statistically significant correlations, and that none of the indirect indices was capable of describing either cardiac performance or the state of the cardiovascular system comprehensively, or unambiguously, in these patients.

Adult↗

Early changes in bacterial envelopes after inhibition of peptidoglycan synthesis, as shown by the use of a fluorescent probe.

The probe 8-anilino-1-naphthalene sulphonate (ANS) showed increasing fluorescence with Bacillus subtilis metC lyt-2 cells taken from exponentially growing cultures treated with antibiotics that inhibit cell-wall peptidoglycan synthesis. This increase was due to the probe reaching hydrophobic cell constituents, probably membranes, and started within 30 min of the addition of the antibiotics. This corresponded to the time at which membrane function had been shown to be damaged. The increased fluorescence of the cells with ANS persisted after removal of the antibiotics.

Anilino Naphthalenesulfonates↗

Nephrotic syndrome in the elderly.

Study of hospital activity analysis data over a ten-year period in a district general hospital show that nephrotic syndrome is uncommon in the elderly. The spectrum of histology, however, is no different from the younger adults. The other interesting findings were: diabetic elderly with nephrotic syndrome may have minimal change, therefore should have renal biopsy; and occurrence of sero-negative lupus nephritis in a 90-year-old male and a focal glomerulo-nephritis in a 75-year-old female.

Aged↗

Sugar ring conformations of guanine nucleosides by proton nuclear magnetic resonance.

Proton NMR studies at 250 MHz showed that ribofuranosyl and 2-deoxyribofuranosyl derivatives of N2-(p-n-butylphenyl)guanine (BuPG) favored the C2'-endo (S) sugar pucker and the gg exocyclic group rotamer, although less so than guanosine and 2'-deoxyguanosine themselves. The correlation calculated between C3'-endo (N) and gg conformational states in these compounds may result from destabilization of syn glycosidic bond conformers by the bulky N2 substituent. Results for a bis(ribofuranosyl) derivative of BuPG showed a strong correlation between N and gg states in both sugar rings, suggesting that both rings are anti and are stabilized by intramolecular hydrogen bonding between C3'-O and H8.

Guanosine↗

Ovarian tumor antigens: preliminary histological investigation.

The immunoglobulin IgG was isolated from the immune complexes obtained from the ascitic fluids of patients with ovarian serous cystadenocarcinoma. The IgG isolates did not react in immunoperoxidase staining of normal ovarian, fallopian tube, or endocervical tissue. In contrast, the IgG isolates did react in immunoperoxidase staining of autologous and allogeneic ovarian cancer tissue. However, the staining was variable in terms of areas of positivity and was completely absent in some serial sections. This variability was also evident in control sections of an ovarian mucinous cystadenocarcinoma that was positive for the carcinoembryonic antigen. In addition, it appears that serous and mucinous ovarian cancers may share common antigenic determinants. These results demonstrate the antigenic heterogenous nature of ovarian cancer.

Antigen-Antibody Complex↗

A blind randomised cross-over trial comparing metipranolol 0.3% with timolol 0.25% in open-angle glaucoma: a pilot study.

A blind randomised cross-over study was conducted on 10 patients (20 eyes) to compare the effect in patients with open-angle glaucoma of metipranolol 0.3% with that of timolol 0.25% on intraocular pressure following one month's topical instillation with each preparation alone. There was no statistically significant difference in intraocular pressure reduction between these two preparations, and the ocular tolerance of both was good. There was no significant difference in the blood pressure, pulse, or pupil diameters of patients receiving either preparation.

Aged↗

A new class of propylthiouracil analogs: comparison of 5'-deiodinase inhibition and antithyroid activity.

After in vivo administration, propylthiouracil (PTU) inhibits not only thyroid iodide uptake and organification, but also T4 5'-deiodinase activity in most peripheral organs. The present report describes the effects of some previously untested 6-substituted 2-thiouracil derivatives on in vivo and in vitro iodide uptake and organification, and on T4 5'-deiodinase activity in liver and pituitary homogenates. When added to homogenates, many analogs were as potent or more potent than PTU in inhibiting hepatic T4 5'-deiodinase activity. Three derivatives, 6-anilino-2-thiouracil (A compound), 6-(p-ethylanilino)2-thiouracil (B compound), and 6-(p-n-butylanilino) 2-thiouracil (C compound), which were among the most potent inhibitors of hepatic T4 5'-deiodinase, when added in vitro inhibited T4 5'-deiodinase activity in liver homogenates after in vivo administration. When added to pituitary homogenates prepared from hypothyroid rats, these compounds also significantly inhibited pituitary T4 5'-deiodinase activity. In a concentration of 1 mM in the presence of 20 mM dithiothreitol, the percent inhibition of pituitary T4 5'-deiodinase activity was 19.7 +/- 7.4 (mean +/- SE), 34.0 +/- 3.2, 47.3 +/- 3.1, and 89.0 +/- 1.0 for PTU and the A, B, and C compounds, respectively (P less than 0.05 for all groups vs. one another and vehicle). Despite their ability to inhibit hepatic T4 5'-deiodinase activity, none of the 13 analogs tested altered thyroid iodide uptake or organification after administration of 0.1 mg/rat. PTU, in the same dose, inhibited thyroid iodide uptake by 78.2 +/- 2.4% (P less than 0.001) and thyroid iodide organification by 36.4 +/- 7.3% (P less than 0.01). Furthermore, the A, B, and C compounds did not inhibit thyroid iodide uptake or iodide organification when administered in higher doses of 5, 5, and 1 mg/rat, respectively. In contrast to these in vivo results, the A, B, and C compounds were more potent than PTU in inhibiting iodide organification in a purified thyroid peroxidase system and in porcine thyroid slices. The concentrations causing 50% inhibition of iodide organification in the purified thyroid peroxidase system were 30, 7, 8, and 14 microM for PTU and the A, B, and C compounds, respectively. However, PTU was far more potent in inhibiting iodide organification in intact incubated thyroid lobes compared to the A, B, and C compounds.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗