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Biomedical subjects

V W Lee

Publications and source records attributed to V W Lee.

At least 73 records · Page 4Linked to original sources
PubMed1985

The role of endogenous opioid peptides in the effects of constant illumination on reproductive function in the rat.

The present experiments assessed the involvement of endogenous opioids in the inhibition of FSH and LH release, ovulation and continuous sexual receptivity following exposure to constant illumination. In the first experiment, exposure to constant illumination resulted in persistent vaginal oestrus in all rats. The injection of naloxone resulted in marked elevations in serum FSH and LH, induced ovulation and increased the frequency of lordosis behaviour. It was concluded that endogenous opioid(s) participate in these effects. In Experiment 2, levels of beta-endorphin were found to be elevated in anterior pituitary and neurointermediate lobe tissue extracts from rats exposed to constant illumination, compared to levels in pro-oestrus rats. Naloxone injection into those rats exposed to constant illumination significantly increased hypothalamic levels of beta-endorphin compared to saline injected controls. This suggests that the blockade of opiate receptors increases beta-endorphin production, uptake and/or decreases its release from the hypothalamus. These results, and the known inhibitory action of beta-endorphin on LH release suggest that it may be this opioid, perhaps in conjunction with pineal products, which is responsible for the observed anti-reproductive effects of constant illumination.

Animals↗
PubMed1985

Scintiangiographic demonstration of parasitization of systemic blood supply by inflammatory lung disease.

An unusual case in which a computed tomogram demonstrated abnormal, enlarged vessels in the right lower lobe of the lung and suggested an arteriovenous malformation is presented. A scintiangiogram showed abnormal systemic supply to this area in the aortic phase. Contrast angiography demonstrated hypertrophy of the right inferior phrenic artery with abnormal systemic supply to the pleura and parenchyma of the right lower lobe, presumably on the basis of old infection.

Erythrocytes↗
PubMed1985

Ovulation rate and inhibin levels in gonadotrophin-treated mice.

Ovarian follicular growth was induced in immature female mice with varying doses of pregnant mare's serum gonadotrophin. The numbers of ovulations were determined either by counting tubal oocytes or corpora lutea in the ovary. Ovarian and circulatory levels of inhibin rose progressively with increasing doses of PMSG and a positive correlation (P less than 0.01) was found between circulating inhibin levels and ovulation rate. The latter correlation makes it likely that the growing preovulatory ovarian follicles are the predominant source for the secretion of inhibin into the circulatory system.

Animals↗
PubMed1984

Dipyridamole-thallium-201 scintigraphy in the prediction of future cardiac events after acute myocardial infarction.

To evaluate the safety and usefulness of serial thallium scanning immediately after intravenous dipyridamole, we studied 51 patients recovering from acute myocardial infarction. Eight patients experienced angina during the procedure, but there were no serious complications. Patients were followed for a mean period of 19 months after hospital discharge. Eleven of 12 patients who died during follow-up or had another infarction had shown transient defects (redistribution) on their predischarge scan, as had 22 of the 24 patients who needed readmission for management of angina. Among all the other clinical or scintigraphic criteria tested, the presence of redistribution on the dipyridamole-thallium scan was the only significant predictor of these serious cardiac events. Twenty-six patients were also given a submaximal exercise test before discharge, of whom 13 subsequently had serious cardiac events. The exercise test had been positive in only 6 of these 13 patients, whereas the dipyridamole-thallium scan had shown a redistribution pattern in 12 (P less than 0.001). We conclude from this preliminary study that dipyridamole-thallium scintigraphy after myocardial infraction is relatively safe. It appears to be a more sensitive predictor of subsequent cardiac events than a submaximal exercise test and may therefore prove useful in evaluating patients after recovery from a myocardial infarction.

Aged↗
PubMed1984

Sustained improvement of cardiac function in patients with congestive heart failure after short-term infusion of dobutamine.

Fifteen patients with congestive cardiomyopathy (six idiopathic and nine alcoholic) manifested by heart failure (New York Heart Association class III or IV) were randomly assigned to a protocol in which dobutamine (n = 8) or 5% dextrose in water (n = 7) was infused continuously for 72 hr. The dose of dobutamine was titrated to increase cardiac output to twice the baseline values. The patients were evaluated before infusion, shortly after infusion, and 1, 2, and 4 weeks thereafter. Functional class improved in six of eight dobutamine-treated patients but in only two of seven control patients during the 4 week observation period. Maximal exercise time and left ventricular ejection fraction increased significantly above baseline only in the dobutamine group. However, neither dobutamine nor placebo infusion produced significant changes shortly after infusion in heart rate, cardiac index, or total peripheral vascular resistance at rest or during exercise at similar workloads. The group receiving dobutamine did show a reduction in systemic systolic and pulmonary arterial mean and diastolic pressure at rest (123 +/- 5 to 108 +/- 6, 32 +/- 5, to 24 +/- 3, and 26 +/- 4 to 20 +/- 2 mm Hg, respectively). In addition, total body oxygen consumption during similar workloads was lower after dobutamine infusion than before.(ABSTRACT TRUNCATED AT 250 WORDS)

Catecholamines↗
PubMed1984

Hepatocellular carcinoma: uptake of 99mTc-IDA in primary tumor and metastasis.

Four consecutive cases of proven hepatocellular carcinoma (HCC) showed significant avidity of 99mTc -labeled iminodiacetic acids (Tc- IDAs ) in preoperative scintigraphy. In one patient, the pulmonary metastasis showed uptake of Tc-IDA. Such scintigraphic findings were obvious only in the delayed scans, performed 2 1/2-4 hr after injection. Since Tc- IDAs and bilirubin are functional analogs physiologically, the ability of HCC to concentrate Tc- IDAs may be related to the ability of HCC neoplastic cells to form bile intracellularly. This hypothesis is supported by the fact that intracellular bile granules were found in the tumor cells of all four patients. This suggests a potential for using Tc- IDAs for the specific and preoperative diagnostic of HCC.

Adult↗
PubMed1983

Sensitivity of technetium-99m-pyrophosphate scintigraphy in diagnosing cardiac amyloidosis.

To determine the value of technetium-99m-pyrophosphate myocardial scintigraphy in the diagnosis of amyloid heart disease this procedure was prospectively performed in 20 consecutive patients with biopsy-proven primary amyloidosis. Eleven patients had echocardiographic abnormalities compatible with amyloid cardiomyopathy, 9 of whom had congestive heart failure. Diffuse myocardial pyrophosphate uptake was of equal or greater intensity than that of the ribs in 9 of the 11 patients with echocardiograms suggestive of amyloidosis, but in only 2 of the 9 with normal echocardiograms, despite abnormal electrocardiograms (p less than 0.01). Increased wall thickness measured by M-mode echocardiography correlated with myocardial pyrophosphate uptake (r = 0.68, p less than 0.01). None of 10 control patients with nonamyloid, nonischemic heart disease had a strongly positive myocardial pyrophosphate uptake. Thus, myocardial technetium-99m-pyrophosphate scanning is a sensitive and specific test for the diagnosis of cardiac amyloidosis in patients with congestive heart failure of obscure origin. It does not appear to be of value for the early detection of cardiac involvement in patients with known primary amyloidosis without echocardiographic abnormalities.

Aged↗
PubMed1983

Specific diagnosis of hepatoma using 99mTc-HIDA and other radionuclides.

The difficulty of clinical and radiographical diagnosis of hepatoma is discussed. A case of hepatoma is reported. Both the primary tumor and distant metastases showed strong avidity for 99mTc-HIDA, which normally is concentrated by parenchymal cells of the liver. The potential of using 99mTc-HIDA for the noninvasive investigation of patients suspected of having hepatoma is discussed. The association between tumor avidity for 99mTc-HIDA and the bile-forming ability of tumor cells is of interest.

Adult↗
PubMed1983

Bilomas: a new approach to the diagnosis and treatment.

Biloma, a newly described entity, appears to have gained a heightened clinical interest recently. During the past 18 months we have diagnosed 9 abnormal biliary collections. We discuss here the role of sonography and radionuclide cholescintigraphy in the evaluation of bilomas. The diagnosis of all cases was confirmed by ultrasound-guided percutaneous needle aspiration. Subsequently 7 patients were treated with catheter drainage, obviating the need for any surgery.

Adult↗
PubMed1983

Diaphyseal presentation of Paget disease in long bones.

The authors report a case of polyostotic Paget disease including bilateral tibial involvement with sparing of the ends of each bone. Bone scans with technetium-99m-methylene diphosphonate demonstrated increased activity at the ends of the tibiae, suggesting atypical progression from the shaft toward the joint. This appears to be the first such report to include scintigraphic correlation.

Aged↗
PubMed1983

Amyloidosis of heart and liver: comparison of Tc-99m pyrophosphate and Tc-99m methylene diphosphonate for detection.

A prospective, comparative study was made of the efficacy of technetium-99m pyrophosphate (Tc PYP) and technetium-99m methylene diphosphonate (Tc MDP) in detecting soft-tissue amyloidosis. Tc PYP and Tc MDP scans were obtained within ten-day intervals in seven patients with histologically proven amyloidosis. Tc PYP was a better scanning agent for soft-tissue amyloidosis in all patients. Cardiac and hepatic involvement were proved by autopsy in one patient. Involvement of the heart was confirmed by echocardiography in five patients. The potential use of Tc PYP scanning as a screening test for soft-tissue amyloidosis is discussed.

Adult↗
PubMed1983

Ovarian inhibin content and sensitivity to inhibin in Booroola and control strain Merino ewes.

The inhibin content of ovaries collected from highly fecund Booroola Merino ewes was only one third that of control Merino ewes. Ovariectomized ewes of both strains were treated with charcoal-treated ovine follicular fluid for 2 days. A dose-dependent effect on plasma FSH was observed: maximum FSH suppression was observed on the day after the last injection of follicular fluid. Ewes receiving the highest dose of follicular fluid (total dose 72000 units of inhibin) had FSH levels depressed to only 8% of pre-treatment levels. Booroola ewes showed FSH suppression 1 day earlier than control ewes but otherwise the responses of the two strains to follicular fluid were similar. Plasma LH levels were only slightly depressed with the highest dose of follicular fluid. These results suggest that the feedback relationship of inhibin and FSH in Booroola ewes may be set differently from that in control ewes and this may contribute to the difference in ovulation rate between ewes of the two genotypes.

Animals↗