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Biomedical subjects

T Hill

Publications and source records attributed to T Hill.

At least 91 records · Page 5Linked to original sources
PubMed1988

Angina and exertional myocardial ischemia in diabetic and nondiabetic patients: assessment by exercise thallium scintigraphy.

Patients with diabetes mellitus and coronary artery disease are thought to have painless myocardial ischemia more often than patients without diabetes. We studied 50 consecutive patients with diabetes and 50 consecutive patients without diabetes, all with ischemia, on exercise thallium scintigraphy to show the reliability of angina as a marker for exertional ischemia. The two groups had similar clinical characteristics, treadmill test results, and extent of infarction and ischemia, but only 14 [corrected] patients with diabetes compared with 34 [corrected] patients without diabetes had angina during exertional ischemia. In diabetic patients the extent of retinopathy, nephropathy, or peripheral neuropathy was similar in patients with and without angina. Angina is an unreliable index of myocardial ischemia in diabetic patients with coronary artery disease. Given the increased cardiac morbidity and mortality in such patients, periodic objective assessments of the extent of ischemia are warranted.

Adult↗
PubMed1987

Interaction of lactoferrin and transferrins with the outer membrane of Bordetella pertussis.

Bordetella pertussis was able to grow in vitro under conditions where the only iron present was bound to the iron-binding proteins ovotransferrin, transferrin or lactoferrin. Under these conditions the bacteria produced neither hydroxamate nor phenolate-catecholate siderophores to assist in the procurement of iron. Examination of B. pertussis outer-membrane preparations by SDS-PAGE and immunoblotting showed that the iron-binding protein ovotransferrin was bound directly to the bacterial surface. Assays of the binding of radiolabelled transferrin by the bacteria showed that the association was a specific process and that there was turnover of the bound proteins. Competitive binding assays indicated that lactoferrin could be bound in the same way. It is suggested that B. pertussis obtains iron directly from host iron-binding proteins during infection.

Bacterial Outer Membrane Proteins↗
PubMed1987

Clinical findings after zosteriform spread of herpes simplex virus to the eye of the mouse.

When herpes simplex virus (HSV) is inoculated onto the snout of the inbred strain NIH mouse, clinical disease of the eye ensues only after a delay, due to spread of virus to the eye occurring via neural pathways. This report is concerned with the detailed description of eye disease. Physical signs observed include mydriasis, iritis and keratitis. The incidence of combinations of physical signs has been analysed by the computer and presented as pie-charts to show the complexity and evolution of the eye disease.

Animals↗
PubMed1987

The histology of the eye after zosteriform spread of herpes simplex virus in the mouse.

A murine model of zosteriform spread of herpes simplex virus to the eye is reported. Viral antigens were demonstrated by a peroxidase-antiperoxidase technique in the trigeminal ganglion, iris, ciliary body, and cornea. The histology suggested a spontaneous bacterial superinfection during the later stages of the herpetic disease of the cornea. The relevance to human disease is discussed.

Animals↗
PubMed1987

Uptake, distribution, and oxidation of fatty acids by Leishmania mexicana amastigotes.

Fatty acid uptake, distribution, and beta-oxidation were investigated in Leishmania mexicana amastigotes. The uptake of radiolabeled palmitic, stearic, and oleic acids was similar, reaching 3-6 nmol/10(8) cells in 2 min and 8-12 nmol/10(8) cells in 60 min. The percent of radiolabeled fatty acid that was esterified in the form of triglycerides or phospholipids increased from less than 25% at 2 min to 65-86% at 60 min. The dehydrogenase(s) in an amastigote granule fraction were unusual in that the Vmax for long-chain substrates (0.95-1.6 delta Abs units/min-mg protein) approximated the Vmax for short-chain substrates (0.82-2.0 delta Abs units/min-mg protein), and the Km for long-chain substrates was high (approximately 250 microM), in contrast to data for a mammalian liver mitochondrial fraction. The high Vmax and Km for long-chain substrates suggest a biochemical mechanism for the postulated high utilization of fatty acids as an energy source for amastigotes. Although the primary anti-leishmanial agent, Sb in the form of Pentostam, inhibited oxidation of palmitic acid to CO2 by intact organisms, Sb did not significantly inhibit fatty acid uptake or esterification by organisms, or beta-oxidation by the granule fraction, and the mechanism of action of Sb remains unclear.

Acyl-CoA Dehydrogenase↗
PubMed1986

Non-human primate (baboon) anti-carcinoembryonic antigen antibody infusion in patients with metastatic adenocarcinoma. A phase I study.

A total of 14 patients with advanced visceral carcinoma which produced carcinoembryonic antigen (CEA) were treated in a Phase I study with IV infusion of affinity purified baboon anti-CEA antibody (dosage range from 0.1 to 2 mg/kg body weight). In all 14 patients, the antibody infusion caused a decrease (26% to 97%) in the plasma level of CEA. The degree of decrease depended upon the patients initial CEA level and the amount of antibody given. In 12 of the 14 patients "free" circulating antibody was observed. The plasma half-life of the antibody ranged from 0.7 to 21 h and the duration of detectable free antibody ranged from 3 to 216 h postinfusion. No toxicity was observed for the dosage range of antibody tested. In 9 of the 14 patients a low titer anti-baboon antibody response occurred between 14 and 28 days postinfusion. No clinical regression of carcinoma was documented. In 7 of the 14 patients disease remained stable during the 28-day study period. By the end of the 28-day study period plasma CEA levels had returned to at least the preinfusion level in 11 of the 14 patients.

Adenocarcinoma↗
PubMed1986

Influence of bezafibrate on plasma lipoproteins, biliary lipids and fecal sterols in healthy men.

The effect of a 4-week treatment with 600 mg/day of bezafibrate in addition to a low-cholesterol, fat-modified diet on plasma lipids and lipoproteins and on biliary lipids and fecal sterols was investigated in 12 healthy men aged 25-39, and compared to the effect of the diet plus placebo, using a double-blind crossover design. The comparison of placebo and treatment values indicated that bezafibrate, beyond the effect of the diet, significantly lowered concentrations of circulating triglycerides (-25.5%), total cholesterol (-25.8%), LDL cholesterol (-19.5%), and apolipoprotein B (-19.9%), and increased apolipoprotein A-II concentrations in serum (+15.0%). There was a tendency towards lower biliary bile acid and cholesterol secretion rates with bezafibrate; lithogenic indices in fasting and stimulated bile were similar with the drug and placebo. Fecal bile acid excretion rate with diet plus bezafibrate was significantly less than with diet plus placebo. The data obtained are in accord with the hypothesis that bezafibrate exerts its effects on cholesterol and bile acid metabolism predominantly by decreasing VLDL secretion, possibly through an enhancement of fatty acid beta-oxidation in the liver.

Adult↗
PubMed1986

Track condition and racing injuries in thoroughbred horses.

The incidences of fractures and soft tissue injuries during 68397 starts of thoroughbred horses at New York Racing Association tracks were analyzed concerning track condition, dirt and turf tracks, environmental conditions, length of races, location of fractures on the track, and age of horses. It was concluded that the conditions evaluated are of no importance in the occurrence of racing injuries to thoroughbred horses.

Animals↗
PubMed1985

Permanent cardiac pacing after open heart surgery: congenital heart disease.

A retrospective review of 6,004 patients who underwent open repair of congenital heart defects revealed that 132 patients (2.2%) required permanent cardiac pacing postoperatively. The indications for pacing were early atrioventricular (AV) block in 55%, late onset AV block in 31%, and sick sinus syndrome in 14%. A ventricular septal defect (VSD) was the most common congenital anomaly present alone or in association with other lesions in 67% of the patients. Atrial surgery accounted for 21% of the patients requiring pacing. Ten-year patient survival was found to be 66% (+/- 6%). Thirty-five percent of the deaths were sudden and unexpected, presumably due to an arrhythmia. Reoperation for pacing system failure has occurred too frequently (12% per year). The most common causes for reoperation were battery failure (44%) and exit block (25%).

Adult↗
PubMed1984

External imaging of cerebral muscarinic acetylcholine receptors.

A radioiodinated ligand that binds to muscarinic acetylcholine receptors was shown to distribute in the brain by a receptor-mediated process. With single-photon-emission imaging techniques, radioactivity was detected in the cerebrum but not in the cerebellum, whereas with a flow-limited radiotracer, radioactivity was detected in cerebrum and cerebellum. Single-photon-emission computed tomography showed good definition of the caudate putamen and cortex in man.

Animals↗
PubMed1984

The influence of display characteristics on active pursuit and passively induced eye movements.

A series of experiments has been conducted on human subjects to examine the effect of the movement of small targets located in the peripheral visual field on oculomotor response. Subjects were presented with either a single centrally positioned target or a pair of targets displaced at angles of +/- 5 degrees, +/- 10 degrees and +/- 20 degrees from centre. Target movement was in the horizontal plane, the paired targets always moving in unison. The stimulus waveform consisted of either a sinusoidal or random target motion encompassing a frequency range from 0.1 to 4 Hz with an angular displacement of +/- 3.5 degrees. Subjects made two types of response. First they were instructed to follow the single target or the centre point of the paired targets. In this 'active' pursuit condition the gain of slow-phase eye velocity progressively decreased as the moving targets were moved from the central position to the most peripheral location (+/- 20 degrees). Secondly, subjects were required passively to ignore the target movement by staring blankly ahead. During this 'passive' response nystagmic eye movements were induced for which the slow-phase eye velocity also decreased with increasing target eccentricity, but the gains were always less than those induced during 'active' pursuit. The frequency characteristics of the 'passive' response were very similar to those of the 'active' response, breaking down at frequencies beyond 1 Hz. The ability to suppress the 'passive' response was also investigated by the presentation of a tachistoscopically illuminated earth-fixed target. The response was found to decline as the interval between presentations of the fixation target was decreased from 3000 ms to 100 ms. It is suggested that the 'passive' response originates from a basic velocity drive to the oculomotor system resulting from image movement across the retina. This velocity drive may be cancelled with adequate fixation but must be enhanced to accomplish desired eye velocity during active pursuit.

Eye Movements↗
PubMed1982

Pre- and posttreatment arrests of alcoholic outpatients at a rural mental health center.

Examined pre- and post-arrests of 76 alcoholics treated on an outpatient basis at a rural mental health center and compared with the arrest rates of non-treated alcoholics (N = 36) and the general Wyoming population. It was found that: (1) the treated alcoholics had generally higher arrest rates than the general population; and (2) frequency of arrests for the outpatients did not evidence reduction after treatment.

Adolescent↗
PubMed1982

Trapping of peripheral blood lymphocytes in the pancreas of patients with acute-onset insulin-dependent diabetes mellitus.

Involvement of humoral and cellular autoimmunity in the pathogenesis of insulin-dependent diabetes mellitus (IDDM) is demonstrated by the presence of circulating autoantibodies and the early pancreatic lesion of insulitis. In an effort to detect the early pancreatic lesion in acute onset IDDM, we have labeled peripheral blood lymphocytes with indium oxine 111, reinjected these autologous cells intravenously into the patients, and followed their kinetics over 96 h using an emission computerized tomography (ECT) scanner. The reinjected cells are acutely distributed in the patients' lungs, liver, and spleen (2-12 h). At 24, 48, and 72 h, the labeled lymphocytes are no longer detectable in the lungs or the liver, but are clearly present in the spleen and in the pancreas. Lymphocytic pancreatic infiltration was observed in two of three acute-onset IDDM patients, but not in large number of patients undergoing similar scans for other diseases, suggesting ongoing mononuclear cell infiltration of the pancreas, a possible marker of the lesion of insulitis. Lymphocyte scanning may provide a powerful noninvasive tool for studying patients with IDDM and for selecting those who might benefit from immunosuppressive therapy.

Acute Disease↗
PubMed1972

Mutagen stability of alkylation-sensitive mutants of Bacillus subtilis.

A series of mutations of Bacillus subtilis, conferring sensitivity to methyl methanesulfonate (MMS), were transferred by transformation to a suppressible his(-) stock. The introduction of certain sensitivity mutations prevented the ultraviolet- or MMS-induced, but not the spontaneous, reversion of his(-) to his(+). Not all sensitivity mutations led to this resistance to mutagenesis; a strain with altered deoxyribonucleic acid (DNA) polymerase activity behaved almost normally with respect to its mutagen response, as did an excision-defective, ultraviolet-sensitive strain used as a control. One of the mutagen-stable strains responded to mutagenesis with nitrosomethylguanidine; another appeared stable even to this mutagen. All mutagen-stable strains had DNA polymerase and DNA ligase activity.

Alkanes↗