High-resolution preparative-scale purification of RNA using the Prep Cell.
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Electrophoresis, Polyacrylamide Gel↗
Biomedical subjects
T H Nguyen
Publications and source records attributed to T H Nguyen.
Further characterization of HIV-1 isolates from Ho Chi Minh City, Vietnam.
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Anti-HIV Agents↗
The proform of eosinophil major basic protein: a new maternal serum marker for Down syndrome.
The proform of eosinophil major basic protein (proMBP), the most abundant protein in the eosinophil specific granule, is synthesized by the placenta and secreted into the maternal circulation, where it is found complex-bound to pregnancy-associated plasma protein-A (PAPP-A) and other proteins. We examined the potential of proMBP as a maternal serum marker for fetal Down syndrome (DS) by determining its maternal serum concentration (MSpMBP) in 25 Down syndrome (DS) pregnancies and 152 control pregnancies in the first trimester, and in 105 DS pregnancies and 156 control pregnancies in the second trimester. The median (95 per cent confidence interval) MSpMBP MoM in DS pregnancies (n=15) was 0.66 (0.49-0.79) in gestational weeks 5-9; 1.06 (0.71-1.97) in weeks 10-12 (n=10) and 1.62 (1.18-1.98) in weeks 14-20 (n=105). Using parameterized receiver operator characteristics analysis for proMBP as a single marker for DS, detection rates (DRs) of 22 per cent and 38 per cent, for false-positive rates (FPRs) of 5 per cent, were found in weeks 5-9 (using MSpMBP</=cut-off) and weeks 14-20 (using MSpMBP>/=cut-off), respectively. When age and MSpMBP were used as markers in combination, a DR of 36.8 per cent for an FPR of 5.5 per cent was obtained in weeks 5-9 using a risk cut-off of 1:250. In weeks 14-20 the DR was 48.4 per cent for an FPR of 5.3 per cent using the same risk cut-off. This makes proMBP a marker comparable in diagnostic efficiency to human chorionic gonadotrophin (hCG), and exceeding that of alpha-fetoprotein (AFP) and unconjugated oestriol (uE3), in the second trimester.
Aging↗
Leu518Pro mutation of the beta ig-h3 gene causes lattice corneal dystrophy type I.
PURPOSE: To describe a Japanese family with lattice corneal dystrophy type I, which segregates with a novel mutation, Leu518Pro of the beta ig-h3 gene. METHODS: DNA was extracted from leukocytes in four members (three affected and one unaffected) of a Japanese family with lattice corneal dystrophy type I. Exon 12 of the beta ig-h3 gene was amplified and analyzed with a molecular biologic method. Clinical data were also collected. RESULTS: Three generations of this family have been positively diagnosed with lattice corneal dystrophy, indicating autosomal dominant inheritance. We found a heterozygous point mutation that segregates with the disease phenotype. It was a single base-pair transition (CTG to CCG, Leu to Pro). CONCLUSION: Although it is extremely rare compared with the Arg124Cys mutation of the beta ig-h3 gene, Leu518Pro mutation of the beta ig-h3 also causes lattice corneal dystrophy type I.
Adolescent↗
Evaluation of ultrasound-estimated date of delivery in 17,450 spontaneous singleton births: do we need to modify Naegele's rule?
OBJECTIVE: To compare the size of error in the predicted date of delivery by biparietal diameter (BPD) and last menstrual period (LMP) in different clinical models. MATERIALS AND METHODS: Predicted dates of delivery were calculated in 14,805 spontaneous deliveries with a reliable date of LMP using two assumptions: average length of pregnancy of 280 and of 282 days. Errors in these calculated dates were tested when used alone or combined, i.e. the LMP-predicted date of delivery was used as first choice unless the discrepancy between gestational age calculated by BPD and LMP exceeded 7, 10 or 14 days. RESULTS: The average discrepancy (error) between predicted date of delivery from BPD and LMP and date of spontaneous delivery was 7.96 and 8.63 days, respectively (p < 0.0001). Adding 282 instead of 280 days to the first day of the LMP reduced the error of the LMP method from 8.63 to 8.41 days, reduced the percentage of classified post-term deliveries from 7.9 to 5.2% and increased the preterm births from 3.96 to 4.48%. No models of combined use of LMP and BPD were superior to the use of BPD alone. CONCLUSION: If both BPD and LMP are available, BPD should be used to predict term. If only LMP is available, term should be calculated as the first date of the LMP plus 282.
Delivery, Obstetric↗
Head and neck computed tomography virtual endoscopy: evaluation of a new imaging technique.
OBJECTIVE: To evaluate a new radiographic imaging technique: computed tomography virtual endoscopy (CTVE) for head and neck tumors. STUDY DESIGN: Twenty-one patients presenting with head and neck masses who underwent axial computed tomography (CT) scan with contrast were evaluated by CTVE. Comparisons were made with video-recorded images and operative records to evaluate the potential utility of this new imaging technique. METHODS: Twenty-one patients with aerodigestive head and neck tumors were evaluated by CTVE. One patient had a nasal cylindrical cell papilloma; the remainder, squamous cell carcinomas distributed throughout the upper aerodigestive tract. Patients underwent complete head and neck examination, flexible laryngoscopy, axial CT with contrast, CTVE, and in most cases, operative endoscopy. Available clinical and radiographic evaluations were compared and correlated to CTVE findings. RESULTS: CTVE accurately demonstrated abnormalities caused by intraluminal tumor, but where there was apposition of normal tissue against tumor, inaccurate depictions of surface contour occurred. Contour resolution was limited, and mucosal irregularity could not be defined. There was very good overall correlation between virtual images, flexible laryngoscopic findings, rigid endoscopy, and operative evaluation in cases where oncological resections were performed. CTVE appears to be most accurate in evaluation of subglottic and nasopharyngeal anatomy in our series of patients. CONCLUSION: CTVE is a new radiographic technique that provides surface-contour details. The technique is undergoing rapid technical evolution, and although the image quality is limited in situations where there is apposition of tissue folds, there are a number of potential applications for this new imaging technique.
Aged↗
Diabetes, insulin resistance and dyslipidaemia in lipodystrophic HIV-infected patients on highly active antiretroviral therapy (HAART).
This study assessed glucose tolerance, insulin sensitivity and lipid parameters in HIV-infected patients presenting with lipodystrophy during HAART including protease inhibitors. Fourteen consecutive patients from Rothschild Hospital treated with HAART and presenting with marked facial lipoatrophy were evaluated. A 75 g oral glucose tolerance test (OGTT) with measurement of plasma glucose, insulin, proinsulin and free fatty acids at T0, 30, 60, 90 and 120 min was performed. Lipid parameters (triglycerides, cholesterol, apolipoproteins A1 and B) were studied as well as nutritional and inflammatory markers (albumin, prealbumin, transferrin, haptoglobin, orosomucoid, C-reactive protein), endocrine and cytokine parameters (thyrotropin, cortisol, leptin, interleukin-6), HIV viral load and CD4-lymphocyte count. These patients were compared with 20 non-lipodystrophic protease inhibitor-treated patients. The measurements performed during OGTT showed that among the 14 lipodystrophic patients, 11 (79%) presented with diabetes (5 patients) or normal glucose tolerance but with insulin resistance (6 patients). This frequency was strikingly different in the group of nonlipodystrophic patients, which included only 4 (20%) presenting with diabetes (1 patient), or impaired glucose tolerance (2 patients), or normal glucose tolerance but with insulin resistance (1 patient). Hypertriglyceridaemia was present in 11 lipodystrophic (79%) versus 7 nonlipodystrophic patients (35%). Nutritional and endocrine measurements were normal. An abnormal processing of proinsulin to insulin was excluded. Thus, lipodystrophy during HAART was associated with diabetes, insulin resistance and hypertriglyceridaemia. Diabetes, diagnosed by basal and/or 120 min-OGTT glycaemia, seems more frequent than previously described. The therapeutic consequences of these results deserve evaluation in clinical trials.
Adult↗
Hypoxia-ischemia in perinatal rat brain induces the formation of a low molecular weight isoform of striatal enriched tyrosine phosphatase (STEP).
Protein tyrosine phosphatases play a critical role in controlling tyrosine phosphorylation levels of proteins. Ischemia induces changes in tyrosine phosphorylation. As part of our investigations of the mechanisms responsible for these changes, we studied the effects of cerebral hypoxia-ischemia in 7-day-old (P7) and P21 rat brains on expression of the STEP (striatal enriched phosphatase) family of protein tyrosine phosphatases. P7 and P21 rats were subjected to unilateral hypoxia-ischemia, and brains were analyzed at various intervals of recovery for the presence of STEP. Hypoxia-ischemia induced the formation of a low Mr isoform of STEP, STEP33, in the ipsilateral (damaged) hemisphere but not in the contralateral (undamaged) side. STEP33 produced as a result of ischemia was located exclusively in the cell soluble fraction. In P21 rats, the ischemia-induced elevation in STEP33 was delayed relative to P7 rats. STEP33 was produced by digestion of postsynaptic densities with calpain I and by exposure of NT2/D1 cells expressing STEP to the calcium ionophore A23187. The results suggest that ischemia-induced calcium influx results in the calcium-dependent proteolysis of membrane-associated STEP61 and the concomitant release of STEP33 into the cytoplasm.
Aging↗
Calcium-dependent cleavage of striatal enriched tyrosine phosphatase (STEP).
Striatal enriched phosphatase (STEP) is a family of protein tyrosine phosphatases enriched within the CNS. A member of this family, STEP61, is a membrane-associated protein located in postsynaptic densities of striatal neurons. In this study, we demonstrate that STEP61, is cleaved into smaller isoforms. To clarify the mechanism of cleavage, STEP61 was transiently expressed in NT2/D1 neuronal precursor cells. Exposure of transfected cells to the calcium ionophore, A23187, or to thapsigargin resulted in the rapid cleavage of STEP61. Pretreatment with the calpain inhibitor, calpeptin, or EGTA prevented proteolysis. One of the cleavage products has a relative molecular mass of 33 kDa (STEP33). A protein with the identical mobility is detected following calpain treatment of STEP61 fusion protein or postsynaptic densities purified from rat striatum. Exposure of primary neuronal cultures to glutamate also led to a significant increase in the concentration of a low molecular weight form of STEP. Taken together, these results suggest that in response to a rapid influx of calcium, STEP61, is proteolytically cleaved by calpain, leading to the release of a smaller isoform. This model may explain the rapid appearance of STEP33 in response to transient hypoxia-ischemia in the brain as cells attempt to counter the increase in tyrosine phosphorylation levels following neuronal insults.
Animals↗
Amphotropic retroviral vectors displaying hepatocyte growth factor-envelope fusion proteins improve transduction efficiency of primary hepatocytes.
The development of retroviral vectors with cell-specific targeting capabilities will be an important step toward successful in vitro gene therapy. This article describes the generation of a retroviral vector with enhanced binding abilities for cells bearing the c-Met receptor: the Madin-Darby canine kidney (MDCK) cell line and primary hepatocytes. The human hepatocyte growth factor (HGF) was displayed on murine amphotropic retroviral vectors by fusion to the viral transmembrane envelope glycoprotein (TM). The resulting chimeric envelope HGF-TM was expressed in an amphotropic packaging cell line producing viral particles that display both HGF-TM and the wild-type envelope. These modified viral particles had a titer equivalent to that of unmodified particles. Modified particles infected MDCK cells more efficiently than did unmodified amphotropic retrovirus. Adding anti-HGF antibodies to the viral vector particle supernatant prior to infection confirmed that the increased infection was mediated by the HGF moiety. The chimeric viruses also infected primary mouse and nonhuman primate fetal hepatocytes more effectively. Furthermore, these cells could be induced to proliferate by the modified HGF-TM viruses. Since exogenous HGF is primarily taken up by the liver, these results may have implications for retroviral vector design for liver-directed human gene therapy.
3T3 Cells↗
Identification and molecular characterization of human T lymphotropic virus type II infections in intravenous drug abusers in the former South Vietnam.
Previous serological studies have demonstrated that some 60% of intravenous drug abusers (IVDAs) in urban areas of the former South Vietnam are infected with HTLV-II. In the present report we have attempted to characterize the viruses using restriction fragment length polymorphism (RFLP) and nucleotide sequence analysis of the provirus long terminal repeat (LTR) region. RFLP analysis of nine samples demonstrated that all were infected with the HTLV-IIb subtype. The HTLV-IIa subtype was not detected. Phylogenetic analysis of the nucleotide sequences demonstrated that the viruses clustered closely with HTLV-IIb isolates present in IVDAs from the New York City area. The present molecular analysis together with the previously reported absence of HTLV-II infection in North Vietnam supports the view that HTLV-II may have been introduced from the United States to this part of Asia by military personnel during the Vietnam conflict.
HTLV-II Infections↗
Tumor necrosis factor alpha levels in plasma and whole-blood culture in dengue-infected patients: relationship between virus detection and pre-existing specific antibodies.
The pathogenesis of dengue hemorrhagic fever (DHF) is not well known, but the role of host factors has been suggested. The level of immunoreactive circulating and cell-generated tumor necrosis factor alpha (TNF alpha) was studied in 35 patients with DHF; its relationship with virus isolation and/or genome detection by reverse transcription polymerase chain reaction (RT-PCR) and specific antibodies were detected by hemagglutination inhibition (HI). Large variation of TNF alpha plasma levels was obtained in dengue-infected patients at the same stage of the disease and at the same day after infection. Most of the patients (14 out of 17 patients) who displayed augmented spontaneous in vitro production of TNF alpha by heparinized whole-blood culture compared with controls also had elevated levels of TNF alpha in the plasma. The TNF alpha values in lipopolysaccharide and phytohemagglutinin heparinized whole-blood cultures were not higher in patients than in controls, but low TNF alpha levels were obtained in three out of 30 patients. An inverse correlation was observed between spontaneous in vitro TNF alpha production and viral replication, which raises the issue of the antiviral effect of TNF alpha in dengue infection. The results do not support the hypothesis of the role of antibody-dependent enhancement giving rise to increased viremic titers and production of TNF alpha in patients. The present study demonstrates the activation of the TNF alpha-producing cells in dengue-infected patients and suggests further investigation to define the mechanism and the role of TNF alpha in the pathogenesis of dengue virus infection.
Adolescent↗
Composition of the cell walls of several yeast species.
Cell walls, representing 26%-32% of the cell dry weight, were prepared from several strains of the yeasts Kloeckera apiculata, Debaryomyces hansenii, Zygosaccharomyces bailii, Kluyveromyces marxianus and Saccharomyces cerevisiae. Extraction of the walls with potassium hydroxide at 4 degrees C, followed by saturation of the alkali-soluble extract with ammonium sulphate gave fractions of mannoprotein, alkali-soluble glucan and alkali-insoluble glucan. Chitin was associated with the alkali-insoluble glucan. The proportions of the different fractions within the walls varied with the species and strain. Mannoprotein comprised between 25% and 34% of the walls, the content of alkali-insoluble glucan ranged from 15% to 48%, and the content of alkali-soluble glucan ranged from 10% to 48%. There was significant variation in the physical appearance of the alkali-soluble glucans and the relative viscosity of suspensions of these glucans. The yeasts could represent novel sources of polysaccharides with industrial and medical applications.
Cell Wall↗
Combination of bone marrow and TGF-beta1 augment the healing of critical-sized bone defects.
A 1.5 cm segmental defect in the radius of rabbits was used to compare healing at sites administered TGF-beta, with or without autologous bone marrow, to autogenous cortical bone graft. The carrier for TGF-beta consisted of tricalcium phosphate (TCP) granules and hetastarch. The efficacy of TGF-beta formulations and bone marrow (BM) was compared to autogenous bone, carrier control, and untreated defect sites. Bone measurements taken at necropsy included the anterior-posterior (AP) diameter and medial to lateral (LAT) diameter of the defect; the AP and LAT diameters of both radii measured 1 cm proximal to the distal epiphysis, and the AP and LAT diameters of the mid-shaft of the femora. The bones from each group were subdivided for either histological evaluation or for mechanical testing. Strength (maximum torque), energy, angle of rotation and stiffness were determined for both the treated and contralateral radii. Results of the radiographic, necropsy, and mechanical data for defects administered 1.0 microgram of TGF-beta1 + BM or autogenous cortical bone were similar and indicated superior healing compared to defects left blank or administered the carrier control with or without bone marrow. Defects administered 1.0 microgram of TGF-beta1 + BM or autogenous cortical bone had high mechanical strength relative to the control groups and were characterized histologically as healed primarily with lamellar bone. The results from the defects left blank or administered carrier control were similar and generally characterized by poor healing or nonunion. This study demonstrated substantial equality of healing between 1.0 microgram of TGF-beta1 + BM and autograft indicating that this formulation could function as a substitute for autologous grafts.
Animals↗
Quality-of-life outcomes in long-term survivors of advanced prostate cancer.
The authors evaluate the temporal progression of health-related quality of life (HRQOL) in men treated hormonally with surgical or medical castration, as well as to see if either treatment would be associated with a greater impact on patients' quality of life. The authors assessed general and prostate-targeted HRQOL with two self-administered, validated instruments (the RAND 36-Item Health Survey and the UCLA Prostate Cancer Index) in a longitudinal, observational study of 63 men newly diagnosed with metastatic prostate cancer and treated with bilateral orchiectomy or combined androgen blockade with leuprolide and flutamide. Patients completed the two HRQOL instruments by mail at baseline and at 3- and 6-month intervals after initiation of treatment. Significant improvements were demonstrated in 10 of 14 HRQOL domains for all men during the first 12 months. These include all eight of the general HRQOL domains and the disease-specific domains that address bowel function. The authors identified no differences in any of the general or prostate-targeted HRQOL domains when comparing men who underwent orchiectomy versus combined androgen blockade. Patients with metastatic prostate cancer can be informed that general and prostate-specific HRQOL will be similar, regardless of whether they choose medical or surgical castration, and that health status will likely remain stable or improve during the initial months of treatment. Physicians must make patients aware of both the quantity and quality of life they can expect with advanced prostate cancer, and must actively involve them in their treatment decisions.
Aged↗
Population programme in Viet Nam: highlights from the 1997 Demographic and Health Survey.
"The most recent Demographic and Health Survey of Viet Nam (VN-DHS II) was conducted in 1997 as a nation-wide survey.... This note attempts to give a general overview of some of the initial findings and general highlights of the [survey]...." Sections are included on fertility, contraception, abortion, and infant mortality.
Abortion, Induced↗
Systemic endothelial activation occurs in both mild and severe malaria. Correlating dermal microvascular endothelial cell phenotype and soluble cell adhesion molecules with disease severity.
Fatal Plasmodium falciparum malaria is accompanied by systemic endothelial activation. To study endothelial activation directly during malaria and sepsis in vivo, the expression of cell adhesion molecules on dermal microvascular endothelium was examined in skin biopsies and correlated with plasma levels of soluble (circulating) ICAM-1, E-selectin, and VCAM-1 and the cytokine tumor necrosis factor (TNF)-alpha. Skin biopsies were obtained from 61 cases of severe malaria, 42 cases of uncomplicated malaria, 10 cases of severe systemic sepsis, and 17 uninfected controls. Systemic endothelial activation, represented by the up-regulation of inducible cell adhesion molecules (CAMs) on endothelium and increased levels of soluble CAMs (sCAMs), were seen in both severe and uncomplicated malaria and sepsis when compared with uninfected controls. Plasma levels of sICAM-1, sVCAM-1, and sE-selectin correlated positively with the severity of malaria whereas TNF-alpha was raised nonspecifically in malaria and sepsis. Immunohistochemical evidence of endothelial activation in skin biopsies did not correlate with sCAM levels or disease severity. This indicates a background of systemic endothelial activation, which occurs in both mild and severe malaria and sepsis. The levels of sCAMs in malaria are thus not an accurate reflection of endothelial cell expression of CAMs in a particular vascular bed, and other factors must influence their levels during disease.
Adolescent↗
Schwangerschaftsprotein 1 (SP1) as a maternal serum marker for Down syndrome in the first and second trimesters.
The potential of the maternal serum concentration of schwangerschaftsprotein 1 (MSSP1) as a marker for Down syndrome (DS) pregnancies was evaluated in the fifth to the 20th gestational week using 156 DS pregnancies and 546 unaffected control pregnancies. In DS pregnancies, the median of the multiple of the median (MOM) of MSSP1 was 0.27 [95 per cent confidence interval (CI) 0.11-0.59] in weeks 5-9 (n = 25) and 1.28 (CI 1.11-1.49) in weeks 14-20 (n = 117), significantly different from controls (P < 10(-6). In weeks 10-12, the median MSSP1 MOM was 0.89 (CI 0.20-2.09) (n = 14), not different from controls (P = 0.42). Using MSSP1 alone as a marker for DS gave--in empirical receiver-operator-characteristics (ROC) analysis--a detection rate of about 44 percent for a false-positive rate of about 5 per cent in weeks 5-9 (using MSSP1 MOM < or = cut-off), whereas a sensitivity of about 20 percent was found for a false-positive rate of 5 percent in weeks 14-20 (using MSSP1 MOM > or = cut-off). In parameterized ROC analysis, the detection rates were 38 and 18 percent for a false-positive rate of 5 per cent in weeks 5-9 and 14-20, respectively.
Down Syndrome↗