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Biomedical subjects

C Lee

Publications and source records attributed to C Lee.

At least 973 records · Page 54Linked to original sources
PubMed1982

An anatomic and histologic study of the rat prostate.

Various morphologic features of the rat prostate complex were characterized by anatomic dissection and by light microscope histology. The prostate complex is viewed as a whole and it is related to the individual portions of the male reproductive system. The three lobes of the prostate are designated as ventral, lateral, and dorsal according to their relation to the urethra. These lobes are connected to the urethra by fascia and a series of ducts. Relations of the prostate to the seminal vesicles, coagulating glands, vas deferens and ampullary glands, urinary bladder, and ureters are described. Vascular supply is also reviewed. While the acinar pattern of each prostatic lobe is unique, the dorsal and lateral lobes more closely resemble each other than the ventral lobes.

Animals↗
PubMed1982

Effect of protease inhibitors on androgen receptor analysis in rat prostate cytosol.

Prostate androgen receptors are liable to proteolytic digestion during in vitro analysis; thus, various proteolytic enzyme inhibitors were tested for their ability to improve the androgen receptor assay. The serine (phenylmethylsulfonylflouride, aprotinin, p-aminobenzamidine) and thiol-senine (leupeptin, bacitracin) protease inhibitors individually present in the homogenization buffer significantly increased the measurable androgen binding sites by 30-35% in rat prostate cytosol as determined by saturation analysis with [3H]-17 beta-hydroxy-17-methyl- 4,9 11-estratrien-3-one (R-1881) for 20 hr at 4 degrees C. The apparent binding affinity was also increased by these compounds. Various combinations were tried and aprotinin/bacitracin was found to be additive in effect. This combination was also shown to prevent receptor degradation as determined by sucrose density gradient centrifugation. The carboxyl protease inhibitor, pepstatin A, was ineffective in improving the receptor assay. Rabbit bile, an inhibitor of seminin, interfered with receptor binding thus rendering it ineffective for use in saturation analysis. The results show that the use of serine-thiol protease inhibitors significantly improves the cytosol androgen receptor yield and assay sensitivity; therefore, we recommend routine inclusion of these compounds(s) in the homogenization buffer for androgen receptor assays.

Animals↗
PubMed1982

Reduced prolactin binding to liver membranes during pheromonal emission in the rat.

Between 14 and 27 days of lactation, female rats excrete a pheromone in their feces that is cholic-acid dependent and that strongly attracts young. Previous research has shown that high circulating levels of prolactin are necessary before the pheromone can be emitted. However, during the time of pheromonal emission prolactin in serum conspicuously declines, while in hepatic cytosol the hormone reaches peak levels. We were interested in the question of how the liver can show peak cytosolic concentrations of prolactin at a time of falling blood levels of prolactin. Accordingly, we examined the prolactin binding capacity of liver membrane fractions during selected periods of lactation. We also studied the livers of virgin and pregnant females for comparison. Three membrane fractions were separated: the cell membrane, the nuclear membrane and a fraction consisting of the cell membrane and large non-nuclear organelles. In all three fractions, there was an increase in available and total prolactin binding in the liver when pregnant females were compared with nulliparous females. However, during the time of pheromonal emission, when prolactin in hepatic cytosol was elevated, there was a significant reduction in the prolactin binding capacity of the liver. How such a reduction increases the cytosolic concentration of the hormone and in turn heightens cholic acid output and pheromonal emission remains unsolved.

Animals↗
PubMed1982

Delay of castration induced regression in rat prostate by pituitary homografts.

Although prolactin has a synergistic effect with testosterone in stimulating growth of the lateral lobe of the rat prostate, the role of prolactin in the absence of testosterone has not been well established. We studied the effect of prolactin on the rate of prostatic regression induced by castration in mature Sprague-Dawley rats. Anterior pituitaries from female rats were transplanted under the renal capsule in all rats. Castration and unilateral nephrectomy were carried out 1 week later. Half of the animals had the normal, non-grafted kidney removed and another half had the kidney bearing the pituitary grafts excised. Rats were sacrificed on days 0, 7, 10 and 14 and 3 lobes of the prostate were dissected separately. The lateral lobe showed a marked decrease in the rate of regression in the pituitary graft-bearing rats. In control animals, the relative weight of the lateral lobe on days 7, 10 and 14 was 38 +/- 2 per cent (mean +/- SE), 33 +/- 2 per cent and 26 +/- 2 per cent of the day 0 value, respectively; the respective relative weight in animals carrying pituitary grafts was 67 +/- 4 per cent, 51 +/- 5 per cent, and 38 +/- 3 per cent of the day 0 value. The difference in the weight of the lateral lobe between the 2 groups was significant on days 7 (p less than 0.001) and 10 (p less than 0.05) and was not significant on day 14. There was no difference in the mean body weight in graft bearing and non-graft bearing animals. Bilateral adrenalectomy at the time of castration did not influence the rate of prostatic regression in either group. Furthermore, pituitaries implanted in rats castrated for 3 weeks had no stimulatory effect of the prostates. These results indicate that increased endogenous prolactin, in the absence of testicular and adrenal secretion, delays the castration-induced regression of the lateral lobe of the prostate of Sprague-Dawley rats.

Adrenal Glands↗
PubMed1982

Activities of cathepsin D in rat prostate during castration induced involution.

The possibility that an intracellular proteolytic process is activated during castration induced prostatic regression warrants consideration and investigation. We investigated the activities of cathepsin D, a lysosomal proteolytic enzyme, in the prostate of rats at different intervals following castration. The enzyme activity was noted to increase during the period of rapid prostatic involution. Administration of exogenous testosterone in varying doses to castrated rats prevented or retarded prostatic weight loss as well as the increase in cathepsin D activity in a dose related manner. Administration of actinomycin D to castrated rats also retarded ventral prostate regression and decreased cathepsin D activity. These observations suggest that cathepsin D is actively synthesized in the regressing prostate and that the enzyme may play an important role in castration induced prostatic regression.

Androgens↗
PubMed1982

Ultrasonography and hepatobiliary scintigraphy in the assessment of biliary-enteric anastomoses.

Twenty-three patients with surgical diversion of the biliary tract were serially studied with ultrasonography and hepatobiliary scintigraphy using 99mTc-HIDA or 99mTc-disofenin. Refluxed biliary air resulted in nondiagnostic sonograms in 14% of cases. Persistent postoperative dilatation was present in five patients (22%). Scintigraphy allowed differentiation of biliary dilatation with obstruction from nonobstructed dilatation. By coordinating the noninvasive imaging results, those patients requiring study using direct injection of contrast material may be selected.

Adult↗
PubMed1982

Lymphopenia and abnormal lymphocyte subsets in the "BB" rat: relationship to the diabetic syndrome.

The "BB" rat spontaneously develops insulitis followed by impaired glucose tolerance (IGT) and/or an insulin-dependent diabetic syndrome like that in man. All diabetic rats in this study showed marked lymphopenia in blood, lymph nodes, spleen, and thymus. Peripheral blood lymphopenia antedated glucoregulatory disturbances. All rats showing either insulitis with or without IGT or diabetes were lymphopenic. None with normal lymphocyte counts developed any abnormality. Diabetics showed marked decrease in the proportions of T+ lymphocytes in all tissues. The proportion of B (Ia+) lymphocytes was normal in blood, spleen and thymus, but increased in lymph nodes. However, in absolute terms both T and Ia+ lymphocytes were decreased. The subset decreased by the greatest proportion in all tissues was that which includes helper T lymphocytes. Thus: a) generalized lymphopenia most marked for T lymphocytes has been shown, b) helper T lymphocytes show proportionally the greatest reduction, c)thymic helper T deficit suggests a thymic origin of the lymphopenia, d) lymphopenia is a possible marker for susceptibility to the syndrome.

Animals↗
PubMed1982

Radiologic evaluation of surgical cervical spine fusion.

Preoperative, intraoperative, and postoperative radiologic evaluation of surgical cervical spine fusion plays an integral part in the management of cervical spine injuries. The radiographic anatomy of the basic types of anterior, posterior, and combined fusions and the indications for their performance are discussed. A retrospective review of 210 consecutive cervical spine fusions showed a 21.1% radiographic complication rate for anterior fusions and only 3.9% for posterior fusions. The high complication rate of anterior fusions is related to the performance of anterior fusion in the presence of unrecognized posterior instability. Radiographically identified complications must be correlated with the clinical neurologic examination in each case since the spectrum of radiographic complications may be compatible with a clinically satisfactory result.

Adolescent↗
PubMed1982

Triangular cervical vertebral body fractures: diagnostic significance.

A common feature of many fractures of the cervical spine is a triangular fragment broken from some part of the vertebral body. The radiographs of 109 patients with cervical spine fractures having a triangular vertebral body fragment were reviewed. Thirteen patients had two triangular fragments, a total of 122 triangular fragments. Eighty-eight (72%) fractures involved the anterior-inferior corner of the vertebral body. Other triangular fractures occurred in anterior-superior (16%), posterior-inferior (11%), and posterior-superior (1%) corners. The position and origin of these fragments are related to the mechanism of fracture. Complete radiographic assessment including tomography and CT revealed that these triangular corner fractures had other associated injuries of the body and of the posterior elements, characteristic of each particular form of triangular fragment. A knowledge of these patterns of injury guides the radiographic evaluation when a triangular fracture is identified on the initial lateral radiograph. A systematic approach to the evaluation of cervical spine fractures based on these triangular fragments is suggested.

Adolescent↗
PubMed1982

Sagittal fracture of the cervical vertebral body.

The sagittal fracture of the cervical vertebral body is an uncommon injury producing the paradoxic situation of profound quadriplegia with either normal or minimal radiographic findings and may be overlooked if polytomography or computed tomography (CT) is not performed. The sagittal fracture was the sole fracture of the vertebral body in seven cases encountered in a review of 270 consecutive cervical fractures, and was readily apparent on routine anteroposterior radiographs in two cases, suspected in two cases, but clearly demonstrated in all cases by polytomography or CT. Most (five of seven) occurred with multiple levels of sagittal fractures in which only one case was apparent on routine radiographs. Posterior ring fractures at the lamina or pedicle were commonly present (six of seven), but detected by plain radiographs in only two cases. The sagittal fracture is frequently a component of the teardrop fracture, occurring in 44% (51/116) of teardrop fractures that were additionally reviewed. The plain radiographic findings are emphasized, since they provide the initial clues as to the presence of this injury. Computed tomography and polytomography either confirmed the presence of or detected additional sagittal fractures, as well as determined the presence of frequently associated arch fractures, and should be used if the plain film findings are uncertain, especially if there is quadriplegia present.

Adolescent↗
PubMed1982

Spinal leptomeningeal infiltration by systemic cancer: myelographic features.

Five cases of spinal leptomeningeal infiltration by systemic cancer are presented and myelographic features are discussed with a review of the literature. Common characteristic features are parallel longitudinal striations due to thickened nerve roots in the cauda equina and bizarre irregular filling defects with varying degrees of blocks, resembling arachnoiditis. Another pattern described in the literature consists of multiple nodular filling defects along the nerve roots of the cause equina.

Aged↗
PubMed1982

Neuromuscular effects of atracurium in man.

The neuromuscular effects of atracurium were studied in 25 A.S.A. class I or II patients anesthetized by a N2O-O2 narcotic technique. In five patients incremental doses of 0.05 to 0.1 mg/kg of atracurium were given intravenously every 3 minutes until approximately 95% depression of the evoked electromyographic (EMG) response of the adductor policus muscle was produced. This required 0.25 to 0.35 mg/kg of atracurium. The duration of block (return to 95% of control) was 25 to 50 minutes. In addition, four groups of five patients each received 0.15, 0.25, 0.375, or 0.6mg/kg of atracurium. The block produced by 0.15 mg/kg was 10% to 92% and lasted 8 to 55 minutes. The block produced by 0.25, 0.375, and 0.6 mg/kg was 95% or greater with a duration of action of 30 to 68 minutes, 52 to 70 minutes, and 65 to 95 minutes, respectively. Tracheal intubation was easily carried out in all patients in whom there was a block of 90% or greater. The block could be antagonized by the common clinical combination of atropine and neostigmine. Changes in heart rate and blood pressure following atracurium were less than 5%.

Adolescent↗
PubMed1982

Dissociation of plasma and cerebrospinal fluid beta-endorphin-like immunoactivity levels during pregnancy and parturition.

The association between central (cerebrospinal fluid [CSF]) and peripheral (plasma) levels of beta-endorphin-like immunoactivity (beta-ELI) in nonpregnant women (n = 8) and pregnant women (a) at 16 to 20 weeks of gestation (n = 6), (b) at term (n = 21), and (c) in labor (n = 15) was investigated. Umbilical arterial (n = 11) and venous (n = 11) samples were also obtained. In agreement with previous investigations, it was found that plasma levels of beta-ELI increased during labor (mean +/- SEM: nonpregnant women, 63.5 +/- 18.2; pregnant women at term, 64.0 +/- 12.2; women in labor, 110.8 +/- 30.3 pg/ml), and that levels of umbilical arterial plasma of beta-ELI exceeded those in umbilical venous plasma (132.5 +/- 34.0 versus 68.2 +/- 22.2). However, CSF levels of beta ELI did not change over the course of pregnancy or during labor (nonpregnant women, 36.5 +/- 15.8; pregnant women at 16 to 20 weeks of gestation, 60.1 +/- 10.3; pregnant women at term, 57.5 +/- 8.4; women in labor 48.5 +/- 8.3 pg/ml). This evidence that plasma and CSF levels of beta-ELI are dissociated during labor calls into question inferences regarding behavioral changes during parturition based on plasma beta-ELI measurements.

Endorphins↗