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Biomedical subjects

C Lee

Publications and source records attributed to C Lee.

At least 937 records · Page 52Linked to original sources
PubMed1984

Action of prolactin in regressing prostate: independent of action mediated by androgen receptors.

Hyperprolactinemia, achieved by grafting pituitaries under the renal capsule, has been shown to cause a delay in the rate of castration-induced prostatic regression in rats. The mechanism of this prolactin action is not established, although it has been suggested that the action of prolactin in the rat prostate is mediated through the action of androgen. To explore the possibility that a small amount of residual endogenous androgen present in the prostate at the time of castration acts synergistically with prolactin to cause this delay in prostatic regression, Flutamide has been used in the present study in an attempt to inhibit this residual androgen effect by blocking its interaction with androgen receptors. Two experiments were conducted. In experiment 1, daily sc injections of Flutamide (25 mg/kg) for 7 days to castrated rats supplemented with dihydrotestosterone-filled silastic tubing either 1 or 4 cm long completely suppressed both prostatic weight and protein content to the level that was normally observed in castrated rats receiving empty tubings. Furthermore, treatment of Flutamide to castrated rats did not cause an increase in prostatic weight and protein content over those of castrated rats treated with the vehicle only. These results indicate that Flutamide, at this dosage, is a potent antiandrogen and that the compound itself does not have any androgenic activity in the rat prostate. In experiment 2, adult male rats were castrated and received two female pituitaries grafted under the renal capsule. One week later, their serum prolactin levels increased from 20 +/- 3 ng/ml to 102 +/- 8 ng ml. This elevated level of serum prolactin was associated with a delay in the rate of prostatic regression. Administration of Flutamide, at a dose (25 mg/kg) which completely suppressed prostatic growth, failed to inhibit the delay in prostatic regression in castrated rats bearing the pituitary grafts. Since Flutamide inhibits the androgen action in the prostate by blocking the binding of intracellular dihydrotestosterone to androgen receptors, the failure of Flutamide to block the effect of prolactin suggests that the prolactin action in regressing prostates is not mediated by androgen receptors.

Animals↗
PubMed1984

Sequential disseminated tuberculosis and toxoplasmosis in a Haitian refugee.

A 27-year-old previously healthy male Haitian had sequential disseminated tuberculosis and toxoplasmosis during a three-month period. The former appeared to respond to antituberculous therapy; the latter proved fatal and was diagnosed only at autopsy. We suspect acquired immune deficiency syndrome (AIDS) as the underlying problem, which emphasizes the danger of sequential unusual infections in patients from groups with a high incidence of AIDS. This case also illustrates some of the difficulties of diagnosing toxoplasmosis and the advisability of early empiric therapy in such patients.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Atracurium for intubation in man. A clinical and electromyographic study.

Atracurium is a new competitive neuromuscular blocking agent. We prospectively studied intubating conditions 2.5 minutes after atracurium doses of 0.4 or 0.5 mg/kg. For comparison, we evaluated conditions 1 minute after suxamethonium 1.0 mg/kg, there being 10 patients in each group. The same anaesthetist evaluated conditions during laryngoscopy and intubation in all patients. Intubating conditions were excellent in 33% of patients receiving atracurium 0.4 mg/kg and 60% of those receiving atracurium 0.5 mg/kg after 2.5 minutes; conditions were excellent in 80% of patients 1 minute after suxamethonium. The incidence of successful intubation on the first attempt was 67%, 90%, and 100%, respectively, in the three groups. Atracurium may be a suitable alternative to suxamethonium when speed of intubation is not critical.

Adolescent↗
PubMed1984

Persistence of immunoreactive neurofilament protein breakdown products in transected rat sciatic nerve.

Alterations occurring in nerve proteins of transected nerves were studied in rat sciatic nerves using polyclonal and monoclonal antibodies to identify and monitor neurofilament (NF) epitopes among nerve proteins following their electrophoresis and transfer to nitrocellulose paper. Immunoblot methods identified NF epitopes in NF triplet proteins (Mr 200,000, 150,000, and 68,000) and in NF nontriplet proteins (all other immunobands below Mr 200,000 and above Mr 40,000). NF triplet and nontriplet proteins were Triton-insoluble in both untransected and transected nerves. Extensive loss of NF triplet and most nontriplet proteins occurred during the 24-48-h period following nerve transection and was attributed to proteolytic degradation. Loss of protease-labile NF proteins led to a markedly reduced level of NF immunoreactivity in 2-day transected nerve. NF proteins which survived the 2-day posttransectional period were considered to represent protease-stable NF fragments. These fragments persisted in transected nerve for periods of at least 35 days. Most protease-stable NF fragments which retained immunoreactivity had Mr of 57,000-65,000. Low concentrations of the same immunobands were present in untransected nerves.

Animals↗
PubMed1984

Hepatobiliary scintigraphy and sonography in early biliary obstruction.

The authors examined 139 patients thought to have early, partial, or intermittent biliary obstruction, using sonography, hepatobiliary scintigraphy, and in selected cases contrast cholangiography. Of 125 patients with a well-established final diagnosis, sonography and scintigraphy disagreed in 29 (23%). Scintigraphy revealed early or low-grade obstruction in 13 patients who had no evidence of dilated ductules, while 7 patients with dilatation from prior stone passage or biliary surgery showed normal clearance. The authors conclude that in a preselected population in whom early or low-grade biliary obstruction may be present, disagreement between sonography and scintigraphy is not rare, and the absence of sonographically detectable dilatation does not exclude obstruction.

Adult↗
PubMed1984

Cat medial interlaminar nucleus: retinotopy, relation to tapetum and implications for scotopic vision.

The medial interlaminar nucleus (MIN) of the cat was electrophysiologically mapped in sufficient detail to resolve individual laminae and to allow reconstruction of isoazimuth and isoelevation lines in coronal, sagittal, and horizontal planes. The electrophysiologically defined laminar pattern was in agreement with that revealed anatomically in the same animal, as well as with the general pattern revealed by anatomical methods in several unmapped nuclei. The MIN is made up of three distinct layers, each receiving inputs from one hemi-retina but none representing an entire hemifield. We confirm the findings of Guillery et al. (19) that the contralateral hemifield is represented in layers 1 and 2 through the contralateral and ipsilateral eyes, respectively, and that layer 3 represents the ipsilateral hemifield through the contralateral eye. Elevation and absolute value of azimuth are represented continuously through the MIN. When an isoazimuth line crosses the border between layer 3 and either layer 1 or 2, the absolute value of azimuth is maintained but the sign of the azimuth changes. Adjacent points on either side of this border represent mirror symmetrical visual directions on opposite sides of the vertical meridian. This indicates that the distance from the vertical meridian is an independently coded parameter within the geniculate complex. There is virtually no nasotemporal overlap in any layer of the MIN. The function relating magnification (mm3 per steradian) to eccentricity is strikingly similar to the function relating retinal ganglion cell density to eccentricity, suggesting that a constant fraction of retinal ganglion cells project to the MIN at all eccentricities. Most of the volume of each MIN layer is devoted to lower visual fields. Analysis of the geniculate retinotopic maps of Sanderson (46) reveals no equivalent bias toward lower visual fields in the dorsal lateral geniculate nucleus. The MIN represents a region of retina roughly coincident with the tapetum, suggesting a role of the MIN in dim-light vision.

Animals↗
PubMed1984

Systematic characterization of human prostatic fluid proteins with two-dimensional electrophoresis.

We present a systematic analysis of human prostatic fluid with two-dimensional gel electrophoresis (the ISO-DALT system) and a characterization of normal and disease-related protein patterns. A reference map for prostatic fluid proteins was established by analysis of pooled prostatic fluids from 80 men (age less than or equal to 50 years) without prostatic lesions. Proteins in prostatic fluid that share immunogenicity with serum proteins were identified by use of antibody to whole human-serum protein in an affinity-column fractionation of a reference pool and differential analysis of the absorbed (serum components) and unabsorbed (non-serum components) fractions. Individual prostatic fluids from 30 patients (eight with prostatic cancer, 10 with prostatitis and benign prostatic hyperplasia, six with benign prostatic hyperplasia alone, and six with asymptomatic chronic prostatitis) were scored qualitatively with respect to the presence or absence of 57 major prostatic fluid proteins. Statistically significant, disease-correlated alterations were observed for at least eight of the proteins so scored.

Blood Proteins↗
PubMed1983

Inhibition of protein synthesis by the cordycepin analog of (2'-5')ppp(Ap)nA, (2'-5')ppp(3'dAp)n3'dA, in intact mammalian cells.

The introduction of the cordycepin analog of (2'-5')An, (2'-5')ppp(3'dAp)n3'dA [referred to as (2'-5')p33'dAn], into mouse L929 cells and cultured human fibroblasts resulted in a dose-dependent inhibition of protein synthesis which was comparable to the inhibition observed by (2'-5')ppp(Ap)nA [referred to as (2'-5')p3An]. The inhibition of protein synthesis by (2'-5')p33'dAn was much more persistent than that of the naturally occurring (2'-5')p3An following prolonged incubation of cells. Furthermore, the (2'-5')p3An was cytotoxic to mammalian cells in culture, whereas the (2'-5')p33'dAn was not.

Animals↗
PubMed1983

Acetaminophen-aluminum hydroxide interaction in rabbits.

Acetaminophen-aluminum hydroxide interaction was investigated in a crossover study using six rabbits. Blood samples were collected at various time intervals for up to 6 hr following the oral administration of acetaminophen alone or in combination with aluminum hydroxide. Aluminum hydroxide at a 40-mg/kg dose did not appear to affect the rate and extent of acetaminophen absorption. The influence of aluminum hydroxide on gastric emptying could be compromised by gastric absorption of acetaminophen, resulting in a negligible effect on the overall bioavailability of acetaminophen.

Acetaminophen↗
PubMed1983

Comparative assays for doxepin and desmethyldoxepin using high-performance liquid chromatography and high-performance thin-layer chromatography.

Two chromatographic methods, high-performance liquid chromatography (HPLC) and high-performance thin-layer chromatography (HPTLC) were compared for sensitivity and reproducibility in the analysis of the tricyclic antidepressant doxepin and its metabolite, desmethyldoxepin, in plasma. The HPLC procedure yielded a better reproducibility, as reflected by the coefficient of variation, and a higher sensitivity, as reflected by the minimum detectable quantity. The application of these methods for therapeutic and subtherapeutic monitoring of plasma levels of the drug is described.

Animals↗
PubMed1983

Effect of castration on experimental bacterial prostatitis in rats.

Inoculation of Escherichia coli into the ventral lobe of the rat prostate produced positive bacterial cultures in the expressed fluid of all three lobes of the rat prostate for a prolonged period of time. Orchiectomy at the time of bacterial inoculation significantly shortened the interval of positive bacterial cultures in the prostate expressate.

Animals↗