Search PubMed⌕ Search

Biomedical subjects

G Howard

Publications and source records attributed to G Howard.

At least 235 records · Page 13Linked to original sources
PubMed1984

Pharmacokinetics of different doses of norethisterone oenanthate.

Doses of norethisterone oenanthate of 300, 150, 100 and 50 mg were administered to four groups of subjects. Due to wide intersubject variations there were no statistically significant differences in the pharmacokinetic parameters for the different groups but there were significant correlations between the dose and the mean values for these parameters. There was little difference between the groups in the duration for which ovarian function was suppressed due to the inter-subject variation being greater than the inter-dose effect. The duration of the antifertility action of norethisterone oenanthate cannot be increased by increasing the dose above the standard 200 mg; however, with an injection interval of 60 to 70 days, it seems likely that the dose could be reduced to 150 mg.

Adult↗
PubMed1983

Comparison of the effects of intravenous papaverine hydrochloride and oral pavabid HP capsulets on regional cerebral blood flow in normal individuals.

A single-blind study was conducted in 13 right-handed normal male subjects to compare the effects of oral and i.v. papaverine on regional cerebral blood flow (rCBF). Six xenon-133 inhalation rCBF measurements were performed on each subject; three tests--baseline, placebo, and drug evaluations--were carried out on each of two separate days. The oral and i.v. drugs were randomized for first-day administration. rCBF, measured as flow gray (FG), increased significantly (p less than or equal to 0.001) from baseline with both drug forms. Increases of 10.53% and 13.94% (left and right hemispheres, respectively) were demonstrated 90 min after a single 600-mg dose of oral papaverine. Increases of 5.09% and 8.69%, respectively, were recorded immediately after a single 100-mg dose of i.v. papaverine. FG also increased significantly (p less than or equal to 0.001) for both drug forms when compared to that of placebo. Placebo produced only a slight increase (not significant) with both the oral and i.v. groups. The data show increasing rCBF in normal subjects.

Administration, Oral↗
PubMed1983

Effect of mannitol on increased intracranial pressure.

We studied 61 patients with a closed head injury and increased intracranial pressure (ICP). The ICP was monitored continuously, concomitant with the administration of 20% mannitol. If the ICP remained higher than 25 mm Hg for 10 minutes or more, the patient was included in the study. Analysis of monitoring records delineated four variables that were related to the response of ICP to mannitol: (a) the level of ICP 1 hour before mannitol was administered, (b) the level of ICP when mannitol was administered, (c) the amount of mannitol that was administered immediately before the resulting changes in ICP were measured, and (d) the cumulative amount of mannitol given over the 6 hours before the most recent mannitol dosage was administered. The level of the ICP measurements and the cumulative amount of preceding doses of mannitol influenced the response of ICP to mannitol more than did the size of the dose of mannitol. These findings imply that: (a) the initial administration of more mannitol than is absolutely needed may lead to larger doses being required to control ICP and (b) for that reason, mannitol given on a gram/kilogram, an hourly, or a serum osmolarity basis to control increased ICP has negative long term effects because more mannitol may be required to decrease ICP when an excessive amount of it has been given previously.

Brain Injuries↗
PubMed1982

Who asks for vasectomy reversal and why?

Of the 76 men requesting reversal of vasectomy who were interviewed at Charing Cross Hospital between June 1978 and September 1981, 31 were still married. These men had decided to have a vasectomy during a crisis-a recent pregnancy or financial stress being the commonest reason. Most wanted another child but others wished to be "put back to normal," and a few hoped reversal would help their marriage. Forty-five (59%) were divorced or separated and felt disadvantaged in courtship or remarriage by being infertile, many wives or partners being "desperate" for a pregnancy. A greater number of requests for reversal came from men who had been under 35 at the time of vasectomy and who were more likely to have been divorced, especially if there had been a teenage pregnancy. The risks of regret after sterilisation appear to relate to immaturity at the time of the vasectomy and to be as great for young men as for young women.

Adult↗
PubMed1982

Extracranial carotid artery arteriosclerosis. Diagnosis with continuous-wave Doppler and real-time ultrasound studies.

To determine the predictive accuracy of Doppler and real-time ultrasound studies, continuous-wave Doppler (CWD) and B-mode real-time ultrasound (RTU) studies of the carotid bifurcation were compared in 50 consecutive patients before cervicocranial arteriography. Four categories of CWD results were formed according to the severity of stenosis. Except for mild to moderate stenosis, there was a high degree of agreement (87.5% to 98.1%) between CWD results and arteriographic diagnosis. Of the arteries classified as normal on RTU study, 95.5% were arteriographically normal; of those classified as abnormal, 94.9% were abnormal on arteriography. In 94.7% of the cases in which RTU demonstrated a possible ulcer, the diagnosis was confirmed by arteriography.

Adult↗
PubMed1982

Coupling factor.

Explore the source record for details and available documents.

Animals↗
PubMed1982

A clinical trial of norethisterone oenanthate (Norigest) injected every two months.

A clinical trial was carried out in which Norigest (200 mg norethisterone oenanthate) was administered by intramuscular injection every 56 days into 383 women studied for 5,521 woman-months of use. No pregnancies occurred. Continuation rates at the end of one, two and three years were 76.6%, 63.7% and 33.8%. Only minor side-effects were recorded. After one year of use, 20.1% women had gained more than 2 kg in weight and 14.8% had lost more than 2 kg. There was marked disruption of the menstrual pattern and irregular bleeding was the major cause of discontinuation. In 38% of the injection intervals analysed, women were amenorrhoeic. Norigest proved an effective and acceptable method of fertility control.

Amenorrhea↗
PubMed1982

Effect of injectable norethisterone oenanthate (Norigest) on blood lipid levels.

Lipid concentrations were measured in 74 blood samples from 61 women who had been using the injectable contraceptive Norigest (norethisterone oenanthate) for between 2 to 4-1/2 years. There were no significant changes in the concentrations of total cholesterol, total triglycerides and low density and very low density lipoprotein cholesterol but high density lipoprotein cholesterol was significantly reduced. The reduction in serum HDL-C levels was not correlated with either the serum norethisterone concentrations or the length of use of Norigest nor was it affected by obesity or smoking.

Adult↗
PubMed1982

Cranial computerized tomography in carotid artery transient ischemic attacks.

32 of 45 (71.1%) patients with carotid artery distribution transient ischemic attacks had normal cranial computerized tomography (CCT). 9 (20%) had cerebral atrophy. Incidental abnormalities were found in 3 (6.6%) patients, while a hypodense lesion corresponding to the site of neurological dysfunction was seen in only 1 (2.2%) patient. The latter showed a persistent abnormality in follow-up studies on the 8th and the 23rd day after the initial event. Our clinical CCT correlation did not demonstrate the frequency of hypodense lesions reported by some authors. Furthermore an increased incidence of cerebral atrophy was found compared to the one reported previously.

Aged↗
PubMed1981

Physician attitudes. Management of asymptomatic carotid artery murmur and transient ischemic attacks.

We polled 582 physicians to determine what their approach would be to management of an asymptomatic murmur at the carotid bifurcation and to carotid-distribution transient ischemic attack. We discovered a great disparity in attitudes attributable to location and type of practice. However, there was no difference attributable to age, and few differences were found with respect to measures of the physician's awareness of his own health. Physicians' attitudes and practices do not necessarily parallel scientific literature or recommendations of experts in the field.

Adult↗
PubMed1981

Pharmacokinetics of norethisterone oenanthate in humans.

The pharmacokinetics of a dose of 200 mg NET-OEN were studied after intramuscular injection into nine subjects. Blood levels of NET and NET-OEN increased rapidly, reaching peaks in most subjects within seven days. At all times after injection, serum levels of NET exceeded those of NET-OEN. The half-life of absorption varied from 5.4 to 22.3 days and the half-life of elimination varied from 7.5 to 22.5 days; there was a significant correlation (R = 0.78) between these two half-lives. There were significant correlations between the absorption half-lives and the peak values of NET and NET-OEN, the time to reach peak values and the time for which NET was detectable in serum. In all subjects NET was detectable in the circulation for a longer time after injection (mean value 74 days) than NET-OEN (mean value 43 days). The time for which the two steroids were detectable in the circulation showed a significant correlation with the elimination half-lives but there was no correlation with the peak values attained, the time taken to reach peak values and bioavailability. There was a two-fold variation between the subjects in the bioavailability of NET, less than 5% of the bioavailable NET was released after day 60.

Absorption↗
PubMed1980

Somatosensory central latencies and disc discrimination in multiple sclerosis.

1. Somatosensory evoked potentials are abnormal in a large percentage of patients with severe multiple sclerosis if amplitude, latency and right-left asymmetry are all considered. Mild disease has remained difficult to identify. This screening test employing two stimulus sites in the same arm did not improve the yield. 2. Stimulation of the median nerve at the elbow is not often likely to justify the associated discomfort, except in patients with known disease in the forearm. 3. Measuring the central conduction velocities from easily recorded low cervical potentials up to the parietal scalp deflections eliminates the need to consider the length and health of the peripheral nerve stimulated. 4. Central conduction velocities were not significantly related to age or total body height in this population. Extremely old or tall subjects may still deserve special consideration if the cervical responses are truly nerve propagated waves. 5. One restricted measure of stereogno-sis--disc size discrimination, correlated well with conduction times from the low cervical region to short-latency deflections in the post-central parietal area, but patients with delayed onset of deflections still maintained normal interpeak latencies. 6. more precise correlations between components of stereognosis, and the integrity of mediating neurons, will be possible when the electrical generators of the SER are better delineated.

Aging↗
PubMed1979

An epilepsy workshop for professionals.

This experimental study evaluated the impact of an epilepsy workshop format designed for community professionals who may be involved in the treatment plan and follow-up of patients. The goals of the workshop were to increase the professional's knowledge and comfort in the presence of epilepsy and to effect better delivery of services to patients. To achieve this, a didactic approach to learning was modified to include patient contact and participant involvement in the learning process. A pre- and posttest experimental design was utilized. Those who attended the workshop improved significantly more than the two control groups in their knowledge of and comfort with epilepsy. Following the workshop, there was a marked increase in the referral of school children for possible neurological problems by teachers who had attended. There was a subsequent improvement in the delivery of health care services to such children in this county.

Adolescent↗
PubMed1979

Infant heart rate response to trigeminal airstream stimulation: determination of normal and deviant values.

In this study, trigeminal airstream stimulation is used on a group of normal, sleeping infants to screen for reflex bradycardia. Infants were tested at 1--3 days and at 4, 8, 12, and 16 weeks of age. The usual heart rate response was acceleration above the prestimulus level. The amount of heart rate change was seen to depend on prestimulus rate and, to a lesser extent, postconceptional age. Multiple regression analysis of the data provided estimates of expected responses, given postconceptional age and prestimulus heart rate. From these, ranges were established for classification of normal or abnormal responses. Six deviant data points over 2 SDs from expected values were identified. Two of these represented heart rate increases and four were heart rate decreases. One deviant heart rate decrease was over 3 SDs from the mean. Although the deviant increases were thought to represent exaggerated startles, the more severe heart rate decreases were believed to be a reflex resembling the diving reflex.

Heart Rate↗