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Biomedical subjects

W Lee

Publications and source records attributed to W Lee.

At least 163 records · Page 9Linked to original sources
PubMed1998

Regional changes of NADPH-diaphorase and neuropeptide Y neurons in the cerebral cortex of aged Fischer 344 rats.

This study examined the effects of aging on neuropeptide Y (NPY) and NADPH-diaphorase (NADPH-d)-positive neurons of the cerebral cortex in young (3 months) and aged (24 months) Fischer 344 rats by immunohistochemical and histochemical methods. In the aged group, the number of NPY-immunoreactive (IR)/NADPH-d-positive neurons was not significantly changed in all regions of the cerebral cortex compared to the control group. However, the number of NPY-IR/NADPH-d-negative neurons was significantly decreased in frontal association, primary motor, secondary somatosensory, insular, ectorhinal, perirhinal and auditory cortex in the aged group. In the aged rats, about 5-10% of NPY-IR/NADPH-d-positive neurons were dystrophic and scattered within the cerebral cortex. These results suggested that NPY-IR neurons that do not contain NADPH-d are affected by aging and that aging influences NPY-IR/NADPH-d-negative neurons in a region-specific pattern within the cerebral cortex of rats.

Aging↗
PubMed1998

Biliary cystadenoma of the liver.

Hepatobiliary cystadenoma is an uncommon lesion that is difficult to diagnose preoperatively. Here we report a 34-year-old woman who presented with enlargement of a cyst that had been observed for the previous 6 months. Diagnostic imaging revealed a 7-cm diameter cystic mass with irregular multiple septation in her liver. All laboratory test results were normal except for serum carbohydrate antigen (CA) 19-9 (62.5 U/ml). Because of the malignant potential and the history of enlargement, a complete surgical excision was performed. The patient was discharged after a good recovery; 2 months after surgery her serum CA19-9 level had returned to normal (32.9 U/ml). Regardless of the diagnostic modalities used, cystadenoma and cystadenocarcinoma cannot be differentiated with accuracy. Therefore complete surgical resection is the recommended therapy.

Adenoma, Bile Duct↗
PubMed1998

Right fetal cardiac axis: clinical significance and associated findings.

OBJECTIVE: To ascertain the clinical significance of right fetal cardiac axis. METHODS: Fetal cardiac axis was assessed prospectively in ultrasound examinations of 16,562 fetuses over a 6-year period. RESULTS: Twenty-two fetuses had a right cardiac axis. When classified by ventricular and atrial configuration, six fetuses had mirror-image hearts with situs inversus, 12 had rotation of the heart axis alone, and four had inversion of the ventricles. Fourteen of the 22 had underlying structural cardiac defects, most of which were atrioventricular septal defects, double outlet right ventricles, or common atria. The chromosomes and/or phenotypes of all 22 were normal. All four fetuses with polysplenia and asplenia died. Major extracardiac defects were few (two) but lethal. CONCLUSION: Right cardiac axis in the fetus is associated with a high incidence of structural cardiac defects. In the absence of severe extracardiac defects, polysplenia, or asplenia, neonatal outcome was good.

Dextrocardia↗
PubMed1998

Effects of a 532 nm Q-switched nanosecond pulsed laser on dentin.

The purpose of this study was to determine whether a nanosecond-pulsed, frequency-doubled Nd:YAG laser emitting at 532 nm can be used as an alternative to mechanical methods of root canal treatment or as an adjunct to conventional endodontic preparation. Laser parameters whose thermal effects did not exceed safety thresholds for adjacent periodontal tissues were selected in a preliminary study. In 27 extracted human teeth, root canals were irradiated for 30 to 60 s at fluences of 2 to 2.2 J/cm2, and 10 Hz. Samples were observed using SEM. Laser irradiation could achieve smear layer removal after minimal manual preparation. However, results were inhomogeneous, and at higher energy densities thermal damage was observed, especially in the fully manually prepared samples. Nanosecond-pulsed irradiation at 532 nm can achieve complete smear layer removal. However, mechanisms must be developed to monitor laser effects and avoid potential damage to collateral structures.

Dentin↗
PubMed1998

Effects of intravenous immunoglobulin on plasma interleukin-10 levels in Kawasaki disease.

Kawasaki disease is an acute febrile disease in children and many inflammatory cytokines are known to be involved in its pathogenesis. Interleukin-10 (IL-10) is an anti-inflammatory cytokine and previous reports have shown blood IL-10 levels were elevated during the acute phase of Kawasaki disease. In this study, we endeavoured to clarify the effects of i.v.IG on plasma IL-10 levels and to verify by RT-PCR, using specific primers, whether viral IL-10 or human IL-10 was responsible for high plasma IL-10. T-cells and B-cells were separated using magnetic beads, and IL-10 mRNA expressions were tested in both cell types. The mean plasma IL-10 levels were significantly decreased from 125.037 +/- 111.161 pg/ml, before i.v.IG treatment, to 32.437 +/- 54.716 pg/ml, after i.v.IG treatment, in subjects with Kawasaki disease. The levels of patients before i.v.IG treatment were significantly higher than those of the acute febrile patients (mean 26.956 +/- 13.316 pg/ml) and the normal controls (mean 16.042 +/- 5.088 pg/ml). RT-PCR was performed using specific primers to distinguish whether viral IL-10 (BCRF-1) or human IL-10 was produced in Kawasaki disease. Viral IL-10 (BCRF-1) mRNA expression was not detected in any groups and only human IL-10 mRNA transcripts were detected in PBMCs of Kawasaki patients as well as in those of acute febrile patients and normal controls. Human IL-10 mRNA transcripts were detected in both CD3+ T-cells and CD19+ B-cells. Elevated IL-10 levels during the acute phase of Kawasaki disease decreased immediately after i.v.IG administration, coincidentally with rapid improvement of inflammatory symptoms. Elevated plasma IL-10 in Kawasaki disease was transcripted from the human IL-10 gene and IL-10 mRNA expressions were detected in both T- and B-cells. Therefore, this study suggests that plasma IL-10 levels may be useful in the early identification and discrimination of the acute phase of Kawasaki disease from other febrile diseases. However, i.v.IG effects on IL-10 production still needs further investigation.

B-Lymphocytes↗
PubMed1998

Acute lymphoblastic leukemia with maturation--a new entity with clinical significance.

The diagnosis of 'ALL with maturation' (ALLm) is proposed. One hundred and one patients with untreated ALL were entered into this study. The diagnosis of ALLm was made when more than 20% of all nucleated elements in the bone marrow showed maturation beyond prolymphocytes by light microscopic examination. The mature-appearing leukemic cells showed the same immunophenotype to remaining lymphoblasts. The number of ALLm cases was 19 (18.8%). The mean age at presentation of ALLm was 29 +/- 18, older than that of 18 +/- 16 of the remaining typical ALL (ALLt) (P = 0.015). Remission was induced with daunorubicin, vincristine, prednisone and L-asparaginase. Only two of 19 ALLm patients achieved CR after 4 weeks induction chemotherapy. In contrast, 57 of 82 (69.5%) ALLt patients achieved CR after the same induction chemotherapy. There was no significant difference in immunophenotype of ALLm compared with ALLt. Labeling index of DNA topoisomerase IIalpha (TopoLI) was studied by immunohistochemistry. Initial TopoLI of ALLm (221 +/- 147) was much lower than that of ALLt (609 +/- 262, P = 0.005). Furthermore, the remaining leukemic cells after chemotherapy were not labeled with anti-DNA topoisomerase IIalpha. The P53 protein was expressed in nine of 18 ALLm cases (50.0%) and P-glycoprotein was not expressed in ALLm cases. Twelve of 19 ALLm cases were studied for carrying bcr/abl fusion by karyotyping and/or fluorescent in situ hybridization. Only two cases revealed bcr/abl fusion. In conclusion, ALLm is a separate entity of ALL which has a very poor clinical course and is independent of other prognostic factors. The morphologically mature leukemic cells are in resting GO phase.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1998

Association between culturable human immunodeficiency virus type 1 (HIV-1) in semen and HIV-1 RNA levels in semen and blood: evidence for compartmentalization of HIV-1 between semen and blood.

Both qualitative and quantitative virologic measurements were compared between blood and genital compartments for 128 men infected with human immunodeficiency virus type 1 (HIV-1) to address several controversial issues concerning HIV-1 shedding in semen and to obtain further information about the distribution of virus between these two compartments. Evidence for viral compartmentalization was suggested by earlier studies that noted the poor correlation between blood and seminal virus load, phenotype, and genotype. Further support for this viral compartmentalization was based on the following observations between semen and blood: lack of association between culturability of virus in semen and viral RNA level in blood, discordant distribution of viral phenotypes, discordant viral RNA levels, a weak correlation between viral RNA level in semen and CD4 cell count in blood, differences in the biologic variability of viral RNA levels, and differences in the virus load response to antiretroviral therapy.

Adult↗
PubMed1998

Lectin-oral streptococci interactions.

Lectins of various specificities were examined for interaction with strains of oral streptococci of various species. The lectins were capable of binding galactose, N-acetylgalactosamine, glucose, N-acetylglucosamine, mannose, fucose and sialic acid. Lectin reactivities were strain-dependent in that some members of a species, but not others, could be aggregated by certain lectins. Proteolysis and extraction with hot water, guanidine hydrochloride and sodium dodecyl sulphate tended to increase the reactivity of the streptococci with lectins but did not change the recognition patterns of the bacteria. Sonication, in contrast, tended to reduce the ability of streptococci to be agglutinated by lectins. Furthermore, lectin reactivities were dependent on the growth conditions, as evidenced by changes in lectin titres following streptococcal growth in sub-inhibitory concentrations of citrate, fluoride or antibiotics. It is likely that lectins could be useful tools for epidemiological studies and to probe strain-dependent and growth-dependent surface characteristics of viridans streptococci.

Agglutination Tests↗
PubMed1998

The roles of transcription and translation in mediating the effect of electrical afterdischarge on neurohormone synthesis in Aplysia bag cell neurons.

The molecular links between membrane excitability and neurohormone synthesis were investigated using a simple model system: the bag cell neurons of Aplysia. We tested the hypothesis that the electrical afterdischarge, which leads to depletion of egg-laying hormone (ELH) by triggering secretion, rapidly stimulates ELH synthesis to replenish bag cell stores of hormone. Newly synthesized peptides were radiolabeled, and ELH peptide was immunoprecipitated. Within 4 h of afterdischarge, there was a 100% increase in ELH synthesis compared with that in unstimulated controls. Northern blot analysis showed that ELH messenger RNA (mRNA) levels were not altered for at least 8 h after the onset of afterdischarge. ELH mRNA levels were also not affected by 4-h treatments that inhibited either transcription (with actinomycin D) or translation (with anisomycin). Further work revealed that ELH mRNA is stable, with a half-life exceeding 32 h. Notably, the stimulatory effect of afterdischarge on ELH synthesis was blocked in response to treatment with the transcription inhibitor actinomycin D. These results suggest that the afterdischarge-induced increase in ELH synthesis is mediated by an increase in the rate of translation of already existing ELH mRNA, and that transcription of a non-ELH gene(s) is required for this effect to occur.

Animals↗
PubMed1998

Longitudinal study of bone turnover after acute spinal cord injury.

Increased bone turnover is a sequel of spinal cord injury (SCI) and predisposes to a number of clinically relevant complications, including osteoporosis and fractures. There are limited data available regarding the changes in modern markers of bone metabolism after SCI. We report a 6-month longitudinal follow-up of biochemical markers of bone metabolism (free and total deoxypyridinoline, total pyridinoline, N-telopeptide, osteocalcin, and total alkaline phosphatase) and bone mineral densitometry in 30 subjects with acute SCI. Markers of bone formation showed only a minor rise, remaining within the reference range. In contrast, markers of bone resorption showed a significant rise after acute SCI, peaking around weeks 10-16, with values up to 10 times the upper limit of normal. Paired bone mineral densities (n = 11; on the average, determined 14 weeks apart) showed no change at the hip, lumbar spine, or radius, but demonstrated a decrement in the entire lower limbs. changes in biochemical markers of bone formation and resorption were comparable in patients with quadriplegia and paraplegia, except for a greater increase in quadriplegics in pyridinoline, expressed as a percentage of baseline. In conclusion, a marked increase in bone resorption and modest changes in bone formation occur after SCI, and possibly increased bone resorption occurs in quadriplegia.

Adolescent↗
PubMed1998

Students, clinicians and university tutors: triangulation of clinical data.

The relationship between intuitive clinical awareness and scientific knowledge is reciprocal: clinical hunch fuels scientific theory which in turn informs clinical practice. This paper demonstrates how students may have a pivotal role in a data triangulation process by acting as a channel for the flow of information between speech and language clinicians and academic institutions involved in the education and training of speech and language therapists. The results of a preliminary survey of students' and clinicians' views about the usefulness of collaboration around clinical data are used as the basis for generating a model which shows the shared roles and responsibilities of the participants as well as the crucial focus on improved client management.

Adult↗
PubMed1998

PACE: a model for integrated care of frail older patients. Program of All-inclusive Care for the Elderly.

The Program of All-inclusive Care for the Elderly (PACE) is a model of care that pools Medicare and Medicaid funds to provide acute and long-term care services for older patients through the use of interdisciplinary teams. Services include physician visits, prescription drugs, rehabilitation services, personal care workers, hospitalization, and nursing home care, if needed. PACE programs may also offer social services intervention, case management, respite care, or extended home care nursing. The PACE site assumes financial responsibility for all services. Now that PACE programs can become permanent providers under Medicare, their number is expected to grow.

Aged↗
PubMed1998

Immunodepletion experiments suggest that acyl-coenzyme A:cholesterol acyltransferase-1 (ACAT-1) protein plays a major catalytic role in adult human liver, adrenal gland, macrophages, and kidney, but not in intestines.

The first acyl-coenzyme A:cholesterol acyltransferase (ACAT) cDNA cloned and expressed in 1993 is designated as ACAT-1. In various human tissue homogenates, ACAT-1 protein is effectively solubilized with retention of enzymatic activity by the detergent CHAPS along with high salt. After using anti-ACAT-1 antibodies to quantitatively remove ACAT-1 protein from the solubilized enzyme, measuring the residual ACAT activity remaining in the immunodepleted supernatants allows us to assess the functional significance of ACAT-1 protein in various human tissues. The results showed that ACAT activity was immunodepleted 90% in liver (83% in hepatocytes), 98% in adrenal gland, 91% in macrophages, 80% in kidney, and 19% in intestines, suggesting that ACAT-1 protein plays a major catalytic role in all of the human tissue/cell homogenates examined except intestines. Intestinal ACAT activity is largely resistant to immunodepletion and is much more sensitive to inhibition by the ACAT inhibitor Dup 128 than liver ACAT activity.

Adolescent↗