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Biomedical subjects

M Lee

Publications and source records attributed to M Lee.

At least 829 records · Page 46Linked to original sources
PubMed1990

Oxybutynin-induced reflux esophagitis.

Oxybutynin has less anticholinergic activity than propantheline bromide. Therefore, oxybutynin is often preferentially prescribed for patients at risk of morbid complications of atropine-like adverse effects. We report a case of oxybutynin-induced reflux esophagitis. This probably resulted from the anticholinergic action of oxybutynin, which decreased lower esophageal sphincter tone. We outline a management approach for patients who experience this adverse effect due to oxybutynin or other commonly prescribed medications.

Adult↗
PubMed1990

1,2-Diarylethylenediamines as pre-column fluorescence derivatization reagents in high-performance liquid chromatographic determination of catecholamines in urine and plasma.

Meso- and dl-1,2-diarylethylenediamines (14 species) were evaluated for pre-column fluorescence derivatization reagents in the high-performance liquid chromatographic determination of catecholamines (norepinephrine, epinephrine and dopamine) in human urine and plasma. Of the compounds, meso-1,2-bis(4-methoxyphenyl)ethylenediamine was most preferable for all the catecholamines in terms of sensitivity and selectivity. The detection limit for each catecholamine is approximately 0.5 fmol in a 50-microliters injection volume.

Catecholamines↗
PubMed1990

Evaluation and treatment of a male factor component to unexplained infertility.

The standard semen analysis frequently fails to identify subfertile males even when findings are normal and conversely often fails to identify fertile males with subnormal semen analyses. This has created the need to produce other tests of sperm physiology that will better distinguish a fertile from a subfertile specimen. Understanding more about the nature of the sperm defect should lead to the establishment of more specific and effective therapies. Until that time, it would still be reasonable to try some of the available empirical therapies even though they may work merely by a placebo mechanism.

Ascorbic Acid↗
PubMed1990

Anti-retroviral effect of chlorophyll derivatives (CpD-D) by photosensitization.

A new photosensitizer, CpD(chlorophyll derivatives), previously reported as a promising agent for tumor therapy, was studied to determine its inhibitory effects on Gross leukemia virus(GLV), a mouse retrovirus isolated from the GLV-producing TGV cell line, and the cytocidal effect on the GLV infected cells in vitro, following photodynamic treatment with CpD-D and red light, the viral inactivation and infectivity were examined by measuring the reverse transcriptase(RT) activity of the virus itself and that in cell-free culture supernatant of freshly GLV-infected secondary mouse embryo cells respectively. The cytocidal activity was measured by trypan blue exclusion test. Inhibition of GLV associated RT activity resulted from CpD-D and red light treatment. The RT inhibition effect was immediate and the infectivity of these photodynamically treated GLV to mouse embryo cells was also inhibited. However, specific cytotoxicity of GLV infected cells was not found. Thus, it is concluded that CpD-D may be used as an effective antiviral agent.

AKR murine leukemia virus↗
PubMed1990

A rapid sporozoite ELISA using 3,3',5,5'-tetramethylbenzidine as the substrate chromogen.

A modified version of the standard 2-site sporozoite enzyme-linked immunosorbent assay (ELISA) using 3,3',5,5'-tetramethylbenzidine (TMB) as the substrate chromogen solution was adapted for rapid detection and identification of Plasmodium falciparum and P. vivax circumsporozoite (CS) proteins. The TMB-ELISA was evaluated using sporozoites from experimentally infected mosquitoes and laboratory colonized uninfected mosquitoes. Our data indicate comparable sensitivity levels between the TMB-ELISA and the standard ELISA, i.e., 50 P. falciparum or P. vivax sporozoites/50 microliters of test solution. Reactions inherent to the method were specific and background reactivity was minimal. The TMB-ELISA is rapid (1 hr), simple, uses a minimal amount of monoclonal antibodies, and is suitable for use in a wide range of laboratories.

Animals↗
PubMed1990

Evaluation of a bronchial anastomosis by laser Doppler velocimetry.

Healing after bronchoplasty was evaluated by assessing the bronchial mucosal blood flow by laser Doppler velocimetry in dogs. Bronchoplastic surgery at the right main bronchus was performed and bronchial mucosal blood flow was determined by laser Doppler velocimetry at proximal and distal sides of the anastomosis before and after operation. Four experimental groups were established. After operation the blood flow was adequately preserved, and healing of the anastomosis site was satisfactory in the minimum detachment group and steroid-treated group. Mucosal blood flow was markedly reduced in both proximal and distal sides in the extensive detachment group. The extent of the reduction in the blood flow was smaller in the omentum dressing group than in the extensive detachment group. The state of healing of the anastomosis site was closely related to the bronchial mucosal blood flow.

Anastomosis, Surgical↗
PubMed1990

[A surgical case of atrial septal aneurysm associated with rheumatic mitral and tricuspid disease and coronary-pulmonary artery fistula].

A case of atrial septal aneurysm associated with combined valvular disease and coronary-pulmonary fistula (C-PA fistula) was presented. The patient successfully underwent mitral valve replacement, excision and closure of the aneurysm, tricuspid annuloplasty and closure of C-PA fistula. Atrial septal aneurysm is a rare anomaly and its natural course is thought to be generally good without significant clinical symptoms. However, complications such as cerebral and pulmonary embolism, or occlusion of the atrioventricular vales by the prolapsed aneurysm were reported to occur in small number of cases. In this case, diagnosis of the aneurysm was made by 2-D and Doppler echocardiography and further confirmed by cineangiography. Routine echocardiographic examinations will serve as useful noninvasive method for detection and follow up study of this anomaly.

Arterio-Arterial Fistula↗
PubMed1990

The parental origin of the extra X chromosome in 47,XXX females.

We used X-linked DNA polymorphisms to study the parental origin of X chromosome nondisjunction in 28 47,XXX live-born females. Errors in oogenesis accounted for 26 of the cases, with the majority of these being attributable to an error at meiosis I. We observed an association between advanced parental age and meiosis I nondisjunction--but not meiosis II nondisjunction--in the maternally derived cases. In studies of recombination we found little evidence for an association between pairing failure and X chromosome nondisjunction, but our results suggest that increased recombination near the centromere may play a role in the etiology of the 47,XXX condition.

Adolescent↗
PubMed1990

Modulation of tartrate-resistant acid phosphatase expression by calcitriol in CSF-induced macrophage colonies.

The osteoclast is thought to be a hemopoietically derived cell, but questions exist about which hemopoietic growth factors are responsible for proliferation of osteoclast precursors. Experiments were thus performed to see if recombinant human colony-stimulating factors (CSFs) influenced the expression of tartrate-resistant acid phosphatase (TRAP), an osteoclast marker enzyme, by monkey bone marrow colonies in vitro. In addition, the effect of 1,25-dihydroxyvitamin D3 (calcitriol) on CSF-induced colony growth and TRAP expression was also determined. Bone marrow was obtained from a single Macaca nemestrina monkey, kept frozen in liquid nitrogen, and aliquots of frozen cells were thawed and placed at 10(5) cells per plate in a standard cell colony-forming unit (CFU-C) assay. The recombinant human CSFs (granulocyte-macrophage CSF, GM-CSF; macrophage CSF, M-CSF; interleukin 3, IL-3; and granulocyte CSF, G-CSF) were added to the cultures at 50 U/ml, and calcitriol was titrated for each CSF from 0.1 to 100 nM. Day-14 colonies were stained to demonstrate TRAP-positive cells in individual colonies. GM-CSF caused an increase (193%, p less than 0.0004) in total colony numbers that was only partially inhibited by calcitriol. IL-3 and M-CSF had less effect, and G-CSF had no effect. GM-CSF also caused a large increase in TRAP-positive macrophage (M) colonies (326%, p less than 0.0001) and changed the relative proportion of TRAP-positive M colonies from 39% to 62% of all M colonies. M-CSF caused less increase in numbers of TRAP-positive M colonies and had no effect on the proportion of TRAP-positive colonies. When GM-CSF was present, calcitriol caused a maximum number of TRAP-positive colonies to appear at 1 nM, and it caused a drastic decrease in TRAP-positive colonies at higher doses. Calcitriol at 10 nM caused TRAP-negative colonies to increase in number and proportion when GM-CSF was present, but in the presence of M-CSF, the same dose of calcitriol caused a decline in numbers of TRAP-negative colonies. These results suggest that GM-CSF may be important in the replication of TRAP-positive mononuclear cells that resemble osteoclast precursors and that myeloid cell development may be weighted toward TRAP-positive or TRAP-negative progeny depending on whether GM-CSF or M-CSF predominates. They further suggest that calcitriol concentration may be critical in this process.

Acid Phosphatase↗
PubMed1990

[Intracavitary microspheres incorporating cisplatinum in the treatment of malignant effusions--clinical trials].

A new dosage form of cisplatinum (CDDP), lactic acid oligomer microspheres incorporating cisplatinum (CDDP-ms), is designed to slowly release 70% of contained CDDP. CDDP-ms's acute toxicity is as low as 57% of the toxicity of CDDP aqueous solution, and its therapeutic efficacy is statistically significantly strong as compared with that of CDDP aqueous solution, when examined with experimental peritoneal carcinomatosis induced by mouse M5076 ovarian sarcoma. Clinical trials were carried out in 10 patients with malignant ascites (gastric cancer 6, pseudomyxoma peritonei 2, colon cancer 1, pancreas cancer 1) and in one patient with pleural effusion (lung cancer). CDDP-ms at 100 mg/person in terms of CDDP was injected at bolus into the affected cavity. In the 10 patients with ascites, 7 responded completely, two partially and one did not respond. The patient with pleural effusion responded partially. The response rate was 91%. Five of the 11 patients complained of temporary nausea or vomiting. In 5 patients fever higher than 38 degrees C was seen. No other side effect such as kidney, nor liver-damage or blood cell count abnormality was noted.

Animals↗
PubMed1989

Induction of cytochromes P450IIE1 and P450IIB1 by secondary ketones and the role of P450IIE1 in chloroform metabolism.

It has been shown previously that the potentiation of chloroform-induced hepatotoxicity by linear secondary ketones increases with the carbon-chain length. The present work examines the possibility that this potentiation is due to the induction of P450IIE1. The metabolism of chloroform, as measured using headspace gas chromatography, in the presence of microsomes from acetone-treated rats was elevated threefold compared to controls. Inclusion of monoclonal antibody against P450IIE1 inhibited the metabolism by 81%. Alternate substrates of P450IIE1 were also inhibitory. Chloroform metabolism was observed using purified, reconstituted P450IIE1 plus cytochrome b5, but was not detected using P450IIB1. The inductive effect of 18-hr oral pretreatment (15 mmol/kg body wt) with each of three secondary ketones on two isozymes of rat liver microsomal cytochrome P450, P450IIE1, and P450IIB1 was studied. The content of total microsomal P450 and NADPH-dependent cytochrome c reductase, the rates of oxidation of N-nitrosodimethylamine, benzphetamine, and pentoxyresorufin, as well as levels of immunoreactive protein for both of the isozymes were elevated by the pretreatments in the rank order of acetone less than or equal to 2-butanone less than 2-hexanone, in agreement with other trends noted by previous investigators. The results provide further evidence for the role of P450IIE1 induction in the potentiation phenomenon.

Animals↗
PubMed1989

Attitudes to alcoholism in a Sydney teaching hospital.

The physical and psychosocial tolls that are attributable to alcohol are well-documented. However, our community has been slow to respond to this serious problem. A survey of attitudes to alcoholism at a Sydney teaching hospital found an acceptance of the disease model and an acknowledgement of alcohol as Australia's main problem drug. The vast majority of respondents felt that the National Campaign against Drug Abuse had paid inadequate attention to alcohol.

Alcoholics Anonymous↗
PubMed1989

Fibroblast growth factors are present in adult cardiac myocytes, in vivo [corrected and issued with original paging in Biochem Biophys Res Commun 1988 Dec 30;157(3)].

We have previously shown that the adult heart contains mitogens immunologically identical to acidic and basic fibroblast growth factors. To determine whether these proteins are present in myocytes, we subjected lysates of freshly isolated myocytes to heparin-affinity chromatography. The 1.1 M - 3 M NaCl eluates stimulated incorporation of thymidine into DNA in quiescent Balb/c 3T3 fibroblasts, caused proliferation of vascular endothelial cells, and cross-reacted with antisera raised against acidic (1.1 M) and basic FGF's (1.5 M) by Western blotting and by RIA. These proteins may be involved in cellular differentiation and proliferation and may play an important role in regenerative and repair processes in the heart.

Animals↗