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Biomedical subjects

E D Plotka

Publications and source records attributed to E D Plotka.

At least 37 records · Page 2Linked to original sources
PubMed1983

Aspirin-sulfinpyrazone in prophylaxis of deep venous thrombosis in total hip replacement.

In postoperative hip arthroplasty patients, treatment with aspirin and sulfinpyrazone resulted in a statistically significant reduction of venographically diagnosed thrombi in the proximal veins of the leg. This reduction was most apparent in thrombi that involved the iliac vein. When compared with their placebo-treated counterparts, female patients who received the active treatment experienced a statistically significant 75% reduction of thrombosis, compared with a 32% reduction for men that was not statistically significant. There were no serious adverse effects. Factors were identified that may influence the result of drug prophylaxis trials in deep-vein thrombosis.

Adult↗
PubMed1983

The effect of naloxone on feeding and spontaneous locomotion in the wolf.

The effect of naloxone on food intake and activity levels was studied in the wolf (Canis lupus). Naloxone decreased food intake at both the 1 mg/kg and 5 mg/kg dose. There was no quantitative difference in the magnitude of the decrease in food intake produced by naloxone in winter or summer. Wolves ate significantly greater amounts of deer meat than dog chow after naloxone when expressed on a mass basis but there was no difference when the amounts of food ingested were expressed in calories. This suggests a role for endogenous opiates in the regulation of energy intake. The putative satiety factor, cholecystokinin-octapeptide, had no effect on food intake in wolves. Naloxone decreased spontaneous locomotion and increased time spent resting in wolves. The effects of naloxone on activity were significantly more marked in winter compared to summer.

Animals↗
PubMed1982

Reproductive steroids in white-tailed deer. IV. Origin of progesterone during pregnancy.

The primary source of progesterone during pregnancy in white-tailed deer (Odocoileus virginianus borealis) was examined in two experiments. Ovariectomy at 110 or 156 days of gestation reduced progesterone levels in jugular vein blood serum from 5.1 +/- 0.7 ng/ml to 0.3 +/- 0.1 ng/ml and resulted in termination of pregnancy. Sham-operated does maintained pregnancy and preoperative progesterone levels. Measured at 110 days gestation in three does, progesterone concentrations in ovarian vein, uterine artery and vein, and jugular vein blood serum averaged 319.3 +/- 29.3, 5.9 +/- 0.3, 46.7 +/- 8.9, and 4.9 +/- 0.4 ng/ml, respectively. Ovarian vein concentrations of progesterone fluctuated over a 2-3/4 h collection period between 70 and 1200 ng/ml. Uterine and jugular vein concentrations of progesterone fluctuated less dramatically. These experiments suggest that the ovaries are the principal source of progesterone through the first 156 days of the normal 200-day gestation in white-tailed deer and that the ovaries are essential for maintenance of pregnancy during this time.

Animals↗
PubMed1981

Characterization of seasonal changes in prolactin and growth hormone cells in the hypophyses of white-tailed deer (Odocoileus borealis) by ultrastructural and immunocytochemical techniques.

Prolactin and GH cells were identified in thin sections taken from the adenohypophyses of adult male (6) and female (8) white-tailed deer, collected during all seasons of the year, by locating portions of the same cells in adjacent thick plastic sections immunostained for either PRL or GH. Growth hormone cells were round to ovoid in shape and filled with dense spherical secretory granules which ranged in size from 168 to 682 nm, with a mean diameter of 367 +/- 18 nm (X +/- SD) in the 14 glands studied. No apparent seasonal changes were evident in the ultrastructural appearance of GH cells. Prolactin cells were small and angular in shape during the winter months and contained only a few small secretory granules. By early summer, they wee markedly hypertrophied, round to oval in shape, and densely packed with large spherical secretory granules. The increase in size of PRL secretory granules was most prominent in pregnant females in May, when their mean diameter was approximately double than in midwinter. The ultrastructural appearance of PRL cells in September was similar to that of cells studied in March. The size distribution of PRL secretory granules overlapped that of the GH granules, ranging from 114 to 564 nm, and the mean diameter was 246 +/- 53 nm, calculated from all 14 individual glands. Our observations suggest that the synthesis and secretion of PRL are closely linked to photoperiodic changes in this species, and they demonstrate the necessity of using specific immunocytochemical techniques in the ultrastructural identification of pituitary acidophils, and of specifying the time of year and location (specifies photoperiod) in studies concerning PRL physiology, particularly when dealing with wild animal populations.

Animals↗
PubMed1981

The effect of pinealectomy on seasonal changes in prolactin secretion in the white-tailed deer (Odocoileus virginianus borealis).

Surgery was performed on four buck and four doe 9-month-old white-tailed deer in March of 1978. Pinealectomy was performed on two deer of each sex, and the remaining animals received sham operations. At monthly intervals over the following year, baseline and TRH-stimulated (200 microgram/deer, iv bolus) serum PRL was measured over a 3-h period by RIA. Baseline PRL levels in sham-operated animals followed a circannual pattern, with peak levels occurring in June (74-237 ng/ml for does; 34-193 ng/ml for bucks) and lowest levels occurring in midwinter (0.41-0.44 ng/ml for does; 0.10-0.13 ng/ml for bucks). Pituitary responsivity to TRH followed the same patterns as that seen for basal PRL levels in sham-operated deer, with the highest peak serum PRL responses in June (198-568 ng/ml for does; 190-395 ng/ml for bucks) and the lowest peaks seen in midwinter (0.27-0.80 ng/ml for dose; 0.29-2.62 ng/ml for bucks). Pinealectomy appeared to abolish the circannual basal serum PRL rhythms in bucks, while this rhythm was maintained in does. Basal PRL levels in pinealectomized bucks ranged from 0.36-10.5 ng/ml, and basal levels in pinealectomized does ranged from 0.10-29.4 ng/ml. The greatest peak PRL response to TRH in pinealectomized deer was seen in August (41.2-93.4 ng/ml for does; 32.0-40.5 ng/ml for bucks), while the lowest peak response occurred in January (0.33-11.0 ng/ml for does; 0.50-17.0 ng/ml for bucks). Both sexes retained a degree of seasonality in their pituitary responsiveness to TRH, but the magnitude of the response in pinealectomized deer was greatly diminished in the summer months and increased in the winter months. Our results show that pinealectomy alters the naturally occurring photoperiod-linked seasonal profile of serum PRL in white-tailed deer and the associated pituitary responsiveness to TRH.

Animals↗
PubMed1980

Seasonal changes in prolactin and growth hormone cells in the hypophyses of white-tailed deer (Odocoileus virginianus borealis) studied by light microscopic immunocytochemistry and radioimmunoassay.

Numerous investigators have shown a relationship between basal serum prolactin (PRL) levels and photoperiod in domestic ungulates, and we have shown recently that a similar seasonal baseline serum PRL profile exists in both sexes of a captive but free-breeding population of white-tailed deer. In order to localize and describe the distribution and possible seasonal changes of PRL and growth hormone (GH) cells in the adenohypophyses of deer, we have used antisera raised against ovine PRL and bovine GH and the unlabeled antibody enzyme technique, in conjunction with point counting morphometry. In addition, we have measured seasonal changes in pituitary PRL concentrations in this same population, using a heterologous application of a recently developed homologous radioimmunoassay (RIA) for ovine PRL. Our results show that GH and PRL cells comprise two morphologically separate and immunologically distinct populations. Growth hormone cells were distributed evenly throughout the gland, except in the zona tuberalis, and males had a slightly greater volume density of immunoreactive GH than females; however, there were no differences between sexes in the average size of these cells, and little seasonal change was observed in these cell populations. In contrast to GH cells, the volume density of PRL cells, the size of PRL cells, and the pituitary concentration of RIA--measurable PRL all showed marked seasonal changes in deer of both sexes. These changes were well correlated with one another and with previously reported changes in basal serum levels (in these animals), in that they all reached zenith during midsummer, and nadir in midwinter. Our results demonstrate the necessity of reporting the time of year and latitude (to specify photoperiod) in studies concerning PRL cell physiology, particularly when dealing with any wild animal population.

Animals↗
PubMed1980

Comparison of milk and blood plasma progesterone concentrations in cycling and pregnant mares.

Progesterone concentrations were measured in milk and blood plasma for 15 mares throughout a normal estrous cycle and early pregnancy to determine the feasibility of utilizing progesterone in milk as an indicator of pregnancy. Samples were obtained daily from foaling until diagnosis of pregnancy by rectal examination at 30 to 35 days of gestation. Progesterone in milk and blood plasma was quantified by radioimmunoassay. Mean progesterone concentrations (+/- SE) in plasma from foaling to foal heat and during estrus, luteal phase and pregnancy were .51 +/- .09 ng/ml, .53 +/- .08 ng/ml, 3.88 +/- .26 ng/ml and 4.22 +/- .09 ng/ml, respectively; progesterone concentrations in milk during the same periods were 1.57 +/- .16 ng/ml, 1.41 +/- .06 ng/ml, 4.26 +/- .21 ng/ml and 4.14 +/- .09 ng/ml respectively. Progesterone concentrations in milk were higher than concentrations in plasma only from foaling to foal heat and during estrus. Days of the estrous cycle on which milk and (or) blood plasma progesterone concentrations could be used to detect pregnancy were determined. Progesterone concentrations in milk from seven of the mares on each day from day 1 to 25 of a normal estrous cycle (nonpregnant) were compared to progesterone concentrations in milk from the same seven mares on days 1 to 25 of a subsequent fertile estrous cycle (pregnancy). (The first day that mares refused to accept the stallion respectively.) Identical comparisons were made of progesterone concentrations in blood plasma. Significantly lower progesterone concentrations were observed in milk from nonpregnant mares from days 17 to 22 and in blood plasma from nonpregnant mares from days 15 to 22.

Animals↗
PubMed1979

Comparison of estrogen receptor levels in primary and regional metastatic carcinoma of the breast.

The estrogen receptor (ER) level in carcinoma of the breast is a useful predictor of response to hormonal therapy. Metastatic disease may not have the same level of ER as the primary. In a series of 37 patients who had simultaneous ER determination in both primary neoplasm and regional nodal metastasis there was 81% agreement. The true ER character of the tumor would have been missed in seven patients if only the primary tumor had been sampled. The possible reasons for this discrepancy are discussed. We feel that the nodal metastatic deposit may reflect the true nature of the ER status because it represents a purer concentration of tumor cells as well as representing the aggressive element of the tumor.

Axilla↗
PubMed1979

The limited utility of fibrinogen I 125 leg scanning.

Using venography as the reference procedure, this study examined the utility of fibrinogen I 125 scanning for the detection or demonstration of deep venous thrombosis. The results demonstrate the inability of leg scanning to detect accurately the presence or absence of thrombi in the deep venous system. Most striking was the lack of sensitivity of this procedure in areas where the propensity for embolization is greatest. Sensitivity is extremely low in the anatomic areas where leg scanning demonstrates reasonable specificity. The results are nearly identical in the extremity not operated upon. The validity of all prior studies relying heavily or exclusively on 125I leg scans to determine the presence or absence of thrombi must be critically reassessed.

Fibrinogen↗
PubMed1978

Platelet dysfunction associated with cardiopulmonary bypass.

The clinical significance and pathogenesis of the platelet dysfunction following cardiopulmonary bypass were studied in conjunction with the degree of functional impairment associated with the use of membrane and bubble oxygenators. Forty consecutive patients had the following tests preoperatively and postoperatively: complete blood count (CBC), platelet count, prothrombin consumption time, bleeding time, prothrombin time, partial thromboplastin time, fibrinogen, euglobulin clot lysis, fibrin degradation products, and platelet aggregation tests. Six patients were given 14C-serotonin tests before and after operation, and preoperative and postoperative electron micrographs were made of the platelets of 3 patients. The amount of blood lost, the blood transfused, and plasma hemoglobin levels were also measured. Abnormal aggregation of platelets was found, with no difference between the membrane and bubble oxygenators. In vitro aggregation tests with protamine sulfate and hemoglobin solutions, as well as the 14C-serotonin studies and electron micrographs, suggest that platelets acquire storage pool deficiency and an abnormal membrane during cardiopulmonary bypass.

Blood Coagulation Tests↗
PubMed1978

A technique for pinealectomy in deer, with notes on the neuroanatomy.

A technique for removing the pineal gland in adult and young male deer is described. A unilateral craniotomy or craniectomy was performed and the pineal gland was approached by parting the 2 hemispheres of the brain. The blood vessels supplying the pineal gland were coagulated and the gland was removed with forceps. Magnification, microtechniques, fiberoptic illumination, and bipolar coagulation rendered the surgical procedure safe and precise.

Animals↗
PubMed1977

Functional lutein cyst in a postmenopausal woman.

A postmenopausal woman presented with enlarged breasts, increased vaginal mucus, and elevated serum estrogen and normal progesterone levels. A laparotomy was performed and revealed a cystic right ovary. Histologic examination of the ovary demonstrated a cyst lined by stratified lutein cells with abundant eosinophilic cytoplasm. The endometrium showed cystic and adenomatous hyperplasia. The diagnosis was functional lutein cyst. Removal of the cystic ovary reduced the estrogen levels, and the clinical picture reverted to that of a normal postmenopausal state.

Endometrial Hyperplasia↗