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Biomedical subjects

G Hunter

Publications and source records attributed to G Hunter.

At least 73 records · Page 4Linked to original sources
PubMed1989

Lysis of oocytes by bovine sperm and seminal plasma.

This study examined the lytic activity of bovine seminal plasma on zona-free oocytes commonly used to assess bovine capacitation. Exposure of hamster oocytes (intact or zona-free) to undiluted seminal plasma resulted in lysis within 5 min. With intact oocytes, 1:5 to 1:20 seminal plasma resulted in swelling of the oocytes. With zona-free oocytes, seminal plasma (1:0 to 1:1000) resulted in lysis within 1 min to 3 h depending on dilution. Heating seminal plasma to inactivate complement did not reduce lytic activity, but boiling destroyed it. Lytic activity was present in seminal plasma from vasectomized bulls and in seminal vesicle fluid. After elution of seminal plasma through Sephadex G-200, lytic activity was only associated with the fraction containing proteins of 200,000 to 45,000 dal. Lytic activity remained with washed capacitated bull sperm only when 10(7) sperm/ml or more were coincubated with zona-free oocytes at 37 degrees C for 3 h. In conclusion, both bovine seminal plasma and capacitated sperm were lytic in the zona-free hamster oocyte assay. The results may explain why so few sperm are normally found at the site of fertilization.

Animals↗
PubMed1988

The effects of dance team participation on female adolescent physical fitness and self-concept.

The purpose of this study was to determine to what extent female physical fitness and self-concept are affected by dance team participation in high school. Eight dancers were tested once prior to and once four months after dance team participation. Eight participants from physical education classes, matched for age, weight, height, grade, and race, were tested once at the same time as the second dance team test. Physiological tests were maximum oxygen uptake, sit-and-reach, one-repetition maximum bench press, skinfolds, and hydrostatic weighing. The self-concept tests were Coopersmith Self-Esteem Inventory, Tennessee Self-Concept Scale, and Body Cathexis Scale. Dependent one-tailed t tests were run to determine differences between dance team pre- and posttests and control and dance team posttests. Dance subjects increased maximum oxygen uptake and one-repetition maximum bench press in addition to improving their body composition as evidenced by a significant decrease in total skinfolds and a near significant decrease in percent body fat. The dance team had a significantly higher maximum oxygen uptake than did controls. No other significant differences were seen between groups. Dance team participants significantly improved physical self and social self on the Tennessee Self-Concept Scale. No other significant differences were seen. A factor that may have affected the self-concept results in this study was low dance team status, due to a combination of unsuccessful previous dance teams and a losing football season. Within the limitations of this study, these results indicate that physical fitness is improved as a result of dance team participation; however, self-concept seems to be affected only minimally, if at all, as compared with participation in physical education classes.

Adolescent↗
PubMed1987

Normal and stenotic renal arteries: experimental balloon-expandable intraluminal stenting.

Elastic recoil of the vessel wall is a common cause of failure of percutaneous transluminal angioplasty in renal arteries. To oppose such recoil, balloon-expandable metal stents were implanted in artificially stenotic renal arteries in pigs and normal renal arteries in dogs and pigs. The stents were then examined angiographically and histologically at regular intervals. All stents were completely covered with endothelialized neointima in 3 weeks. There was no difference in intimal thickness between the stenotic and nonstenotic renal arteries. A large stent diameter and a large open or nonmetal surface may cause less intimal hyperplasia, but nonturbulent, fast arterial flow is probably the most important factor in ensuring long-term patency of the vessel.

Angioplasty, Balloon↗
PubMed1987

In vitro sensitivity of human ovarian tumors to chemotherapeutic agents with adjuvant danazol.

Human ovarian tumors have been cultured as primary monolayers in vitro. The in vitro chemosensitivity was determined indirectly using [3H]leucine uptake with cisplatinum, adriamycin, bleomycin, thiotepa, and chlorambucil. Chemosensitivity also was determined using these agents in the presence of danazol. The tumor cultures showed a uniform increase in sensitivity to these agents in the presence of danazol, suggesting that this drug might merit testing as an adjuvant in the chemotherapy of ovarian cancer.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1986

Management of the upper-limb-deficient child with a powered prosthetic device.

A long-term survey of a large number of children fitted with an electrically powered upper-limb prosthesis seems not to have been reported in the literature. Children with upper-limb deficiencies (congenital or traumatic) were fitted with an electrically powered upper-limb prosthesis in Ontario during the 18-year period of 1965-1983. Seventy-eight patients responded to a questionnaire or were interviewed by telephone. The dropout rate in children with a below-elbow amputation was similar to that reported in below-elbow child amputees wearing a conventional body-powered prosthesis (10% vs. 13%). The acceptance rate in children with above-elbow amputations was higher in those wearing an electrically powered prosthesis than in those using the conventional prosthesis, testifying for improved prosthetic function in the former group.

Amputation, Traumatic↗
PubMed1984

Extraction of an intravascularized pacemaker lead--a new approach to an unusual problem.

A new catheter approach to removing an intravascularized, nonfunctional pacemaker lead which was fixed at both distal (right ventricular endocardium) and proximal (brachiocephalic vein/superior vena cava) ends is described. This case also emphasizes the need for removal of an old pacemaker lead that caused bacteremia in a patient with a prosthetic aortic valve even when infection was presumed to be cured.

Aged↗
PubMed1983

Surgically induced carotid subclavian steal syndrome. Diagnosis by video dilution technique.

A rare occurrence of carotid subclavian steal syndrome following carotid subclavian bypass for arm ischemia was described. Blood flows in the carotid artery and carotid subclavian bypass, at rest and following arm exercise, were determined by video dilution technique during the angiographic procedure. There was no obstruction of the inflow or outflow of the proximal or distal anastomoses to account for the steal (55%). Rather, increased arterial flow to the subclavian artery due to the patient's status as a bilateral amputee was thought to be the cause. The diagnosis and subsequent correction by takedown of this bypass and conversion to an axillary-to-axillary bypass were performed. Video dilution technique offers a unique and accurate way to study steal phenomena in conjunction with routine angiography and does not add to the patient's cost or risk.

Angiography↗
PubMed1983

Virus resistance in clinical practice.

The sensitivity to acyclovir of more than 800 herpes simplex virus (HSV) isolates from over 300 patients were tested by the dye-uptake method. While a broad spectrum of sensitivity was found, approximately 90% of the isolates were inhibited by less than 1 mg/l of acyclovir. Therapy usually did not significantly alter the sensitivity of HSV isolates except in a few severely immunocompromised patients in whom resistant viruses produced asymptomatic or indolent infections. The sensitivity of viruses isolated during subsequent recurrences was similar to that of the originally infecting virus, regardless of therapy. The requirement of convenient and standardized methods of virus sensitivity testing is emphasized so that additional data can be accumulated to allow more precise correlations between in-vitro virus sensitivity and clinical response to acyclovir therapy.

Acyclovir↗
PubMed1983

Postoperative carotid restenosis due to neointimal fibromuscular hyperplasia. Clinical, angiographic, and pathological findings.

Following endarterectomy, stenosis can recur in 0.2-3.6% of carotid arteries due to neointimal fibromuscular hyperplasia (NFH). Angiographically, NFH is manifested as concentric, alternating areas of normal tissue and smooth narrowing which are seen as pale, glistening, nonulcerated plaques on gross examination. Histological study demonstrates proliferation of smooth muscle cells, disruption of the internal elastic lamina, and often discontinuity of the endothelium. Calcium and cholesterol deposits are absent. The cause of the lesion is unknown, and surgical management is frequently difficult.

Aged↗
PubMed1983

Alternative management of isolated iliac artery aneurysms.

Isolated iliac artery aneurysms are uncommon and frequently remain undetected until they reach significant size. Often their first clinical presentation is with rupture of the aneurysm. Direct surgical intervention has been the usual mode of treatment. Successful treatment of iliac aneurysms by alternative approaches in two elderly, debilitated patients is reported. Extra-anatomic bypass and catheter embolization were used in both resulting in a minimal in-hospital stay for the patients without morbidity or mortality.

Aged↗
PubMed1983

Effect of methylazoxymethanol acetate on rat liver nuclear and nucleolar RNA synthesis.

The effect of methylazoxymethanol acetate on rat liver nuclear and nucleolar RNA synthesis is investigated at various doses (5 to 50 mg/100 g body weight) and for various lengths of time (1 to 24 hr). The results show that this carcinogen is a potent inhibitor of both nuclear and nucleolar RNA synthesis. Like other carcinogens studied previously in this laboratory, e.g., N-hydroxy-2-acetylaminofluorene, aflatoxin B1, and actinomycin D, methylazoxymethanol acetate inhibits RNA synthesis at multiple sites. It impairs chromatin template function and selectively inhibits the activity of RNA polymerase II. Experimental evidence suggests the mechanism of inhibition of RNA polymerase II activity is due to a decrease in catalytic efficiency rather than in the total number of the enzyme. In addition, it is found that methylazoxymethanol acetate induces a dramatic condensation of nucleoplasmic chromatin.

Animals↗
PubMed1983

Male hypoplastic infrarenal aorta and premature atherosclerosis.

Hypoplasia of the abdominal aorta distal to the origin of the renal arteries may be a contributing factor in the development of early atherosclerosis. The abnormal aortic configuration and resultant increased stress forces may account for the localization of the disease to the aortoiliac segment. The increased frequency of single bifurcating lumbar arteries at the L4-L5 level, easily demonstrable on conventional arteriograms, suggests that the aortic hypoplasia may result from excessive fusion of the paired dorsal aortas during embryonic life. Hypoplasia of the infrarenal aorta is present in 9% of females with aortoiliac disease, and it is believed to be uncommon in males. A review of 408 peripheral arteriograms of males revealed 18 cases (4.4%) of hypoplasia of the abdominal aorta. Males with hypoplastic aortas develop symptoms 10 years earlier than those with normal-sized aortas and 10 years later than females with similar narrowing of the distal aorta.

Adult↗
PubMed1981

A rapid quantitative colorimetric determination of blood acetone applied to the assessment of ketosis in fasted pregnant ewes.

A simple, accurate, colorimetric method for determining blood acetone as an adjunct to the enzymic method of estimating the other ketones was developed and tested on a group of fasted pregnant ewes. Acetone reacted with 2-hydroxybenzaldehyde to form a stable coloured complex that followed Beer's Law up to an acetone concentration of at least 4 mg/100 ml of the test solution at 490 nm. While the optimum incubation time of the reaction mixture was found to be 3 h at 40 degrees C, it could also be left to incubate overnight at room temperature. When tested in a blood matrix, the method gave a mean within-batch coefficient of variation of 0,7%, and a day to day variation of 0,3-1,2%, while an overall recovery of 100, 6+/-1,4% was achieved over 5 concentration ranges (2,86-10,53 mg/100 ml). The values obtained from this method corresponded closely to those from the diffusion technique previously employed and it considerably simplified the procedure. A direct linear relationship, y = 2,594x + 2,917 with a coefficient of determination r2 = 0,958 for 49 pairs of data, was found between the acetone (= x mg/100 ml) and total ketone (= y mg/100 ml) concentrations in blood samples drawn from fasted pregnant sheep. This relationship can therefore be used to estimate accurately the degree of ketosis from the blood acetone concentration alone.

Acetone↗
PubMed1980

Dynamic isotope aortoiliac assessment. Clinical, doppler, and arteriographic correlation.

In the presence of multiple tandem arteriosclerotic stenoses of the distal aorta, iliac, and lower extremity arteries, it may be difficult to ascertain which lesions are clinically and surgically important. Usually the history, physical examination, and arteriogram will resolve this issue. However, a recent report has stated that the rapid transit time of isotope from the distal aorta to the femoral arteries may be helpful. The relevance of this technique in surgical candidates with different clinical stages of vascular disease has yet to be demonstrated. We compared the use of this technique in surgical candidates with their clinical state and assessment of vascular disease by standard angiographic and directional transcutaneous Doppler techniques. Only modest benefit from the isotope transit was found, particularly when compared with the patient's clinical status of asymptomatic, claudicating, or limb salvage categories. We conclude that isotope transit times as currently measured are not as clinically important as previously reported. With further development, some trends may prove to be useful.

Adult↗
PubMed1978

Major amputation following vascular reconstructive procedures (including sympathectomy).

To study the effects of vascular reconstruction or sympathectomy, or both, on the level of amputation, the number of revision procedures performed and the mortality following amputation, the authors reviewed the records of 504 patients from three Toronto teaching hospitals who had one or both limbs removed at or above the below-knee level. It appears that (a) previous vascular surgery or sympathectomy, or both, actually increases the number of patients in whom a below-knee amputation is successful, (b) the number of revision procedures necessary is increased after failed vascular surgery or sympathectomy, or both and (c) revision procedures following amputation do not affect the mortality from lower limb amputation.

Amputation, Surgical↗