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Biomedical subjects

M W Lee

Publications and source records attributed to M W Lee.

At least 73 records · Page 4Linked to original sources

Why is short-term sentence recall verbatim? An evaluation of the role of lexical priming.

By showing that short-term sentence recall can be significantly affected by words encountered in an intervening distractor task, Potter and Lombardi (1990, Journal of Memory and Language, 29, 633-654) argue that short-term sentence recall is often verbatim because of the availability of recently activated lexical entries during the regeneration of the sentence from its conceptual representation. We show that similar effects can be obtained even when bilinguals perform an intervening task in a different language from that of sentence recall, or when monolinguals perform an intervening task upon pictures. Furthermore, we show that the presentation of a word in P&L's distractor task does not, in any case, affect subsequent retrieval of a semantically related word as measured in a picture-naming task. We suggest that the effects on recall reported here and by P&L should be explained in terms of conceptual level interference at the time of recall. We also discuss the implications of our suggestion for the issue of the verbatimness of short-term sentence recall.

Analysis of Variance↗

Prognostic factors and early resumption of cyclosporin A in renal allograft recipients with thrombotic microangiopathy and hemolytic uremic syndrome.

Biopsy-proven thrombotic microangiopathy (TMA) was found in 22 of 436 (5%) renal transplant recipients, with similar incidence in recipients of cadaver or living related allografts. All patients with TMA presented different degrees of severity of the hemolytic uremic syndrome (HUS). Prognosis was poor when HUS occurred shortly after transplant in recipients of cadaveric kidneys (55% graft loss). It was more favorable when HUS occurred later in the post-transplant course or in recipients with allografts from living related donors, irrespective of time of occurrence. Other factors such as extent of TMA, degree of thrombocytopenia, hemolysis or renal dysfunction were not predictive of graft loss. Cyclosporine was resumed in 14 of 16 recipients shortly after clinical recovery without recurrence of HUS. In conclusion, HUS carries poor prognosis when occurring shortly after transplant in cadaver kidney recipients. Once the graft function improves, cyclosporine can be safely resumed.

Adult↗

Overexpression of phosphatidylethanolamine N-methyltransferase 2 in CHO-K1 cells does not attenuate the activity of the CDP-choline pathway for phosphatidylcholine biosynthesis.

Chinese hamster ovary (CHO) cells express only a trace amount of phosphatidylethanolamine N-methyltransferase (PEMT) activity. CHO cells make their phosphatidylcholine (PC) via the CDP-choline pathway. We investigated whether or not overexpression of PEMT2, an isoform of PEMT, in these cells would down-regulate the activity of the CDP-choline pathway. Transfection of CHO cells with PEMT2 cDNA behind the cytomegalovirus promoter resulted in a series of cell lines that overexpressed PEMT2. Phospholipid metabolism was characterized in cell lines that expressed a medium (281 pmol/min per mg of protein) and a high (1300 pmol/min per mg of protein) level of PEMT activity. The expression of the regulated enzyme (CTP:phosphocholine cytidylyltransferase) in the CDP-choline pathway was increased, not decreased, in these cell lines as judged by immunoblot analysis and enzymic activity. Conversion of phosphatidylethanolamine to PC was enhanced in CHO cells that expressed PEMT2 activity. PC mass was not increased in the transfected compared with the control cells. The rate of PC catabolism made by either the CDP-choline or methylation pathways was unaffected by PEMT2 expression. We conclude that expression of PEMT2 in CHO cells does not down-regulate, but rather enhances, the expression of CTP:phosphocholine cytidylyltransferase.

Animals↗

Immunohistochemical demonstration of the nm23-H1 gene product in human malignant melanoma and Spitz nevi.

Expression of the 17kD product of the human nm23-H1 gene has been shown to be reduced in a number of human malignancies including those from the breast, colon, kidney and lung. Somatic allelic deletion of nm23-H1 gene is also associated with a high incidence of distant metastasis and reduced patient survival in colorectal and infiltrating breast ductal carcinomas. We compared the immunohistochemical reactivity of the nm23-H1 gene product in the different histological subtypes of human cutaneous melanoma to that of Spitz nevi. All nine cases of Spitz nevi and five cases of in situ melanoma showed diffuse and intense nm23-H1 protein immunoreactivity. The majority of superficial spreading melanomas (18 of 27 cases) had moderate to strong nm23-H1 protein immunostaining. In contrast, the majority of nodular melanomas (7 of 8 cases) with poor prognostic histological indices displayed marked reduction in immunoreactivity to the nm23-H1 protein. The 2 cases of metastatic melanoma showed reduced or no nm23-H1 protein immunostaining. In conclusion, reduced nm23-H1 immunohistological expression is associated with melanomas that have high metastatic potential and poorer prognosis.

Adolescent↗

Dermal cylindroma and eccrine spiradenoma.

Multiple dermal cylindromas on the scalp and back and eccrine spiradenoma on the face of a 59 year old woman are described. A case for a common origin is discussed.

Adenoma, Sweat Gland↗

Characterization of a partially purified diacylglycerol lipase from bovine aorta.

A partially-purified diacylglycerol (DG) lipase from bovine aorta has been characterized with respect to the effects of lipid metabolites and two lipase inhibitors, phenylboronic acid and tetrahydrolipstatin (THL). DG lipase activity was determined by the hydrolysis of the sn-1 position of 1-[1-14C]palmitoyl-2-oleoyl-sn-glycerol. The products of the lipase reaction, 2-monoacylglycerol (2-monoolein) and non-esterified fatty acids (oleate, archidonate) produced a concentration-dependent (20-200 microM) inhibition of DG lipase activity. Oleoyl-CoA and dioleoylphosphatidic acid also inhibited aortic DG lipase activity, but lysophosphatidylcholine had little or no effect. The inhibition of aortic DG lipase by phenylboronic acid was competitive, with a Ki of approx. 4 mM. THL was a very potent inhibitor of aortic DG lipase; the concentration required for inhibition to 50% of control was 2-6 nM. THL inhibition was reduced when the concentration of substrate in the assay was increased. Attempts to identify the aortic DG lipase by covalent-labelling with [14C]THL were unsuccessful. Immunoblotting experiments revealed that hormone-sensitive triacylglycerol lipase (HSL) could not be detected in bovine aorta.

Animals↗

Mycetoma caused by Acremonium falciforme: successful treatment with itraconazole.

Mycetoma has not been previously reported in Korea. A case of mycetoma caused by Acremonium falciforme in a 72-year-old man is described. The patient had a single, large, well-demarcated, erythematous, swollen, black, escharlike lesion and three small satellite lesions on his right temporal area. He was treated with itraconazole, and all lesions healed with residual scars in 70 days.

Acremonium↗

O-ring coping attachments for removable partial dentures.

Clinical experiences for the past 9 years have demonstrated the practicability of the O-ring coping attachment, a modification of the telescopic crown-and-sleeve coping retainers, for removable partial dentures. A circumferential groove placed in the primary coping receives an elastomeric O-ring that fits into a corresponding groove made in the internal surface of the telescopic crown. The O-ring not only provides controllable retention but also acts as a shock absorber. Long-term retention of the prostheses can be easily maintained by periodic replacements of the O-rings. Sophisticated procedures and expensive machines are not required to make the prostheses. Excellent patient acceptance and the versatility in clinical applications make this system one of the winning designs for removable partial prosthodontics.

Crowns↗

p53 in cutaneous melanoma: immunoreactivity and correlation with prognosis.

p53 protein immunoreactivity was investigated in cutaneous Spitz naevi (n = 7), superficial spreading (n = 21) and nodular (n = 6) melanomas using the monoclonal antibody DO-7. Nuclear immunostaining for p53 protein was observed in 41% of all the melanomas but not in any of the Spitz naevi studied. This difference in p53 immunoreactivity appeared statistically significant (P = 0.0001; chi 2 test). There were also differences in p53 immunoreactivity between superficial spreading and nodular melanomas (P = 0.001, chi 2 test), where up to 38% of superficial spreading melanomas and 50% of nodular melanomas had demonstrated p53 nuclear immunostaining. An apparently significant correlation was observed between melanomas with poor prognostic histological indices and p53 immunoreactivity (P = 0.0016; chi 2 test). In conclusion, increased p53 protein immunoreactivity is found in melanomas and is associated with poorer prognosis. The differences in p53 immunohistological expression between cutaneous melanomas and Spitz naevi suggest that alterations of the protein may be important in the pathogenesis of the tumour.

Adolescent↗

Comparison of activities and attitudes of baccalaureate level and entry-level doctor of pharmacy graduates of the University of Illinois at Chicago.

OBJECTIVE: To determine whether (1) differences exist between BSPharm and PharmD pharmacists in practice site selection, activities, attitudes; and (2) differences in activities and attitudes exist unique between BS and PharmD pharmacists in hospital settings and in community settings. DESIGN: A survey was designed and sent through the mail. SETTING: The BSPharm graduating classes of 1985 and 1986 the PharmD graduating classes of 1988-1990 from the University of Illinois at Chicago. PARTICIPANTS: Usable responses were received from 65% (n = 159) of the BSPharm cohort and 54% (n = 176) of the PharmD cohort. MAIN OUTCOMES: The outcomes under study were: (1) the choice of practice setting of the first job and the current job; (2) percent of time spent in 4 broad categories of pharmacists' activities: prescription processing, clinical activities, management, and educating; (3) levels of intrinsic and extrinsic job satisfaction; and (4) levels of professional commitment. RESULTS: Chi-square results indicated that more BS pharmacists were practicing in community settings than were PharmD pharmacists. Multivariate analysis of variance results indicated that PharmD pharmacists were spending significantly more time in clinical and educating activities, and less time in prescription processing, controlling for any effect associated with age. PharmDs were significantly more committed to the profession and had higher levels of intrinsic job satisfaction. Analysis of data on 122 hospital pharmacists showed that PharmDs were spending significantly more time on educating activities and less time in processing prescriptions than BSPharm pharmacists, and that they were more intrinsically satisfied. No differences were found between BSPharm pharmacists and PharmD pharmacists in community settings. CONCLUSIONS: The results of this study suggest that the additional clinical education in PharmD programs may have a role in developing pharmacists with greater professional commitment and job satisfaction.

Adult↗

Partial purification of a diacylglycerol lipase from bovine aorta.

A diacylglycerol (DG) lipase has been purified from a soluble subcellular fraction of bovine aorta by (NH4)2SO4 precipitation in the presence of 5.0% (w/v) Triton X-100, followed by chromatography on DEAE-Sephacel, heparin-Sepharose and octyl-Sepharose in the presence of either CHAPS or Triton X-100 detergents. Under basal conditions, the hydrolysis of a short-chain [3H]dioctanoylglycerol ([3H]diC8) substrate was much greater than that of a long-chain 1-[1-14C]palmitoyl-2-oleoyl-sn-glycerol (1-[14C]POG) substrate. Lipase activity measured with 1-[14C]POG was markedly enhanced by Triton X-100. In the presence of 0.1% Triton X-100, specific enzyme activities in the octyl-Sepharose fraction determined with 1-[14C]POG or 1-stearoyl-2-[1-14C]-arachidonoyl-sn-glycerol as substrates were the same as that measured with [3H]diC8. MgCl2 (5mM) or CaCl2 (2 mM) also selectively stimulated lipase activity (up to 10-13-fold) measured with the long-chain (1-[14C]POG) substrate only. The increase in relative specific activity in the octyl-Sepharose fraction was 60-fold and 155-fold, based on hydrolysis of [3H]diC8 and 1-[14C]POG (+ Triton X-100), respectively. Unlabelled diC8 was a competitive inhibitor of 1-[14C]POG hydrolysis, suggesting that a single lipase hydrolyses both the short-chain and long-chain DG substrates; selective stimulatory effects of non-ionic detergents and bivalent cations on the hydrolysis of 1-[14C]POG may be due to effects on the physical properties of the substrate preparation. Monoacylglycerol lipase, DG kinase and cholesterol esterase activities could not be detected in the partially purified lipase preparation.

Animals↗

Assay of ornithine aminotransferase with ninhydrin.

We developed an assay system for ornithine aminotransferase (EC 2.6.1.13) using ninhydrin. Pyrroline 5-carboxylate, a product of enzymatic transamination, reacts with ninhydrin under hot acidic conditions to form a reddish pigment soluble in ethanol. The millimolar extinction coefficient of reaction product dissolved in ethanol was 16.5 at 510 nm. Acidification with perchloric acid effectively abolished the interfering color development by L-ornithine and L-glutamate. The paired activity measurement in mouse tissues by ninhydrin and o-aminobenzaldehyde methods showed a good correlation (gamma = 0.985). In our ninhydrin method, stable ninhydrin replaced unstable o-aminobenzaldehyde, and sensitivity was much higher than that with the conventional o-aminobenzaldehyde method.

Animals↗

Determination of the structure for polysubstituted flavonoid and 6-C-glucosyl flavonoids using 13C-1H long range couplings.

A flavone glycoside was isolated from the leaves of Betula platyphylla var. latifolia and characterized as 4',6-Dimethoxy-5-hydroxyflavone-7-O-beta-D-glucoside(pectolinar igenin-7-O -beta-D-glucopyranoside) by method of chemical and NMR spectral analysis. 13C-1H long range coupling was confirmative for determination of its substituted position. In connection with this study, 6-C-Glucosylnalingenin and 6-C-Glucosylaromadendrin were confirmed its structures using this techniques.

Flavonoids↗

The efficacy of barbiturate coma in the management of uncontrolled intracranial hypertension following neurosurgical trauma.

The purpose of this study was to evaluate the role of barbiturate therapy as an adjunctive treatment for control of intracranial hypertension when conventional methods failed. To this end, a retrospective chart review was conducted on 21 neurosurgical trauma patients with uncontrolled intracranial pressure (ICP) admitted to a trauma/intensive care unit. In this patient population, the overall mortality was 48%. Control of ICP was achieved in 67% of patients. The survival of patients experiencing ICP control with barbiturate coma was better than those patients who failed therapy (71% vs 14%, p = 0.021). Thus, in a subgroup of neurosurgical trauma patients who are refractory to conventional management of elevated ICP, barbiturates appear to improve survival, suggesting that this therapy has an important role in the management of neurotrauma patients.

Adolescent↗

Eosinophilic cellulitis case report: treatment options.

Eosinophilic cellulitis in a 56 year old woman is described. The patient responded well to oral prednisolone, but attempts to withdraw the corticosteroid resulted in relapses. Remission was achieved with a combination of dapsone, antihistamine and alternate-day prednisolone.

Administration, Oral↗

Signal transduction in vascular smooth muscle: diacylglycerol second messengers and PKC action.

Agonist-stimulated phospholipid turnover can generate diacylglycerol (DAG), an intracellular second messenger that activates protein kinase C (PKC). DAG can be produced from the hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2) by a phosphoinositide-specific phospholipase C and by the degradation of phosphatidylcholine (PC) by a phospholipase C or the concerted actions of phospholipase D and phosphatidate phosphohydrolase. In vascular smooth muscle, agonist-stimulated DAG accumulation is biphasic; PIP2 hydrolysis produces a transient increase in DAG, which is followed by a sustained phase of DAG accumulation from PC degradation. Metabolism of DAG attenuates PKC activation and thus results in signal termination. The metabolic fates for DAG include 1) ATP-dependent phosphorylation to form phosphatidic acid (DAG kinase), 2) hydrolysis to release fatty acids and glycerol (DAG and monoacylglycerol lipases), 3) synthesis of triacylglycerol (DAG acyltransferase), and 4) synthesis of PC (choline phosphotransferase). Hydrolysis through the lipase pathway is the predominant metabolic fate of DAG in vascular smooth muscle. Activation of PKC in vascular smooth muscle modulates agonist-stimulated phospholipid turnover, produces an increase in contractile force, and regulates cell growth and proliferation. Further research is required to investigate cross talk between signal transduction mechanisms involving lipid second messengers. In addition, spatial considerations such as nuclear PKC activation and the influence of diradylglycerol generation on the duration of PKC activation are important issues.

Animals↗

Comparative immunohistochemical study of primary and metastatic carcinomas of the liver.

Distinguishing primary hepatocellular carcinoma (HCC) from metastatic carcinomas to the liver is often difficult, if not impossible, particularly in needle biopsy and fine-needle aspiration specimens. In an attempt to identify a specific immunohistochemical profile that would distinguish HCC from metastatic carcinomas, we studied 56 HCCs, 8 cholangiocarcinomas, and 24 metastatic adenocarcinomas with monoclonal antibodies to alpha-fetoprotein (AFP), keratin (AE1, AE3, and CAM5.2), Leu-M1, human milk fat globule (HMFG-2), tumor-associated glycoprotein-72(B72.3), epithelial specific membrane antigen (Ber-EP4), and BCA-225 (CU-18). Both monoclonal and polyclonal (mCEA and pCEA) antibodies to carcinoembryonic antigen also were used. Metastatic adenocarcinomas were often positive for CU-18(71%), Leu-M1 (75%), B72.3 (50%), HMFG-2 (67%), Ber-EP4(83%) and mCEA(71%). Using these antibodies, the frequency of positivity for HCC was 9%, 16%, 11%, 20%, 36%, and 11%, respectively. CU-18 was the only monoclonal antibody in which there was a significant difference in positive rates between HCC and metastatic adenocarcinomas. Most HCCs (71%) revealed a bile canalicular staining pattern with pCEA. Because this staining pattern was absent in metastatic carcinomas, pCEA appears to be useful in confirming a diagnosis of HCC. AE1, AE3 and CAM5.2 antibodies were not useful in distinguishing HCC from metastatic carcinomas. Each cholangiocarcinoma shared a staining profile similar to that of metastatic carcinomas.

Adenocarcinoma↗