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J Hou

Publications and source records attributed to J Hou.

At least 55 records · Page 3Linked to original sources
PubMed2000

Realizing the potential of clinical judgment: a real-time strategy for predicting outcomes and cost for medical inpatients.

PURPOSE: We sought to determine whether illness severity and anticipated level of function, as evaluated at the time of admission, were associated with outcomes and costs of care for patients admitted to the medical service. METHODS: All 1,759 patients admitted to the medical service at a large urban academic medical center between July 1, 1997, and September 30, 1997 (excluding those admitted directly to the intensive care units or for protocol chemotherapy), were evaluated and categorized by the admitting intern by illness severity (not ill, mildly ill, moderately ill, severely ill, or moribund) and anticipated level of function at discharge (excellent, good, fair, or poor) as part of their routine sign-out process. Interns' ratings were always available within 24 to 28 hours of admission. In-hospital mortality, length of stay, cost of hospitalization, and anticipated billing revenue were evaluated. RESULTS: Patients who were more severely ill had significantly greater in-hospital mortality. For example, mortality was 1.1% (11 of 972) among those who were not ill or mildly ill, 3.6% (26 of 724) among those who were moderately ill, and 15% (9 of 60) among those who were severely ill. Illness severity (P = 0.003) and anticipated functional status (P < 0.01) were significant predictors of in-hospital mortality. Illness severity and function were also significant predictors of greater length of stay and greater costs of hospitalization (all P < 0.0001). The 389 patients who were moderately ill with fair or poor anticipated function were associated with the largest cumulative losses (about $330,000 during the 3-month period), whereas the 798 mildly ill patients with good or excellent function were associated with the largest cumulative profits ($550,000). CONCLUSION: Physicians' estimates of patients' illness severity and anticipated function at the time of discharge, as made by interns using a system designed to help them sign out to their colleagues, predict outcomes and costs of hospitalization. Such a system may be useful in developing new approaches to management strategies based on prognosis.

Academic Medical Centers↗
PubMed2000

Mechanisms of apoptosis in rat cerebellar granule cells induced by hydroxyl radicals and the effects of EGb761 and its constituents.

In this study investigation is made on whether oxidative stress produced by treatment with hydroxyl radicals can induce apoptosis in rat cerebellar granule cells. The protective effects of Ginkgo biloba extract (EGb761) and its active constituents against apoptosis are also examined. The results show that hydroxyl radicals generated by the Fenton reaction induced apoptosis in cerebellar granule cells, which was associated with the decrease in the Bcl-2 mRNA level and the increase in the protein levels of the transcription factors Fos and Jun. Moreover, hydroxyl radicals induced time-dependent lipid peroxidation in cells and caused the changes in the sulfhydryl group binding sites on the membrane proteins. Hydroxyl radicals may induce apoptosis via different signaling pathways. EGb761 attenuated these changes and its different constituents showed different effects. The total flavonoid component of EGb761 and a mixture of flavonoids and terpenes protected cerebellar granule cells from oxidative damage and apoptosis induced by hydroxyl radicals. Total terpenes of EGb761 did not protect against apoptosis. Flavonoids and terpenes did not show a synergistic effect in this regard.

Animals↗
PubMed2000

Detection of the brain response during a cognitive task using perfusion-based event-related functional MRI.

Event-related (ER) fMRI has evoked great interest due to the ability to depict the dynamic features of human brain function during various cognitive tasks. Thus far, all cognitive ER-fMRI studies have been based on blood oxygenation level-dependent (BOLD) contrast techniques. Compared with BOLD-based fMRI techniques, perfusion-based fMRI is able to localize the region of neuronal activity more accurately. This report demonstrates, for the first time, the detection of the brain response to a cognitive task using high temporal resolution perfusion-based ER-fMRI. An English verb generation task was used in this study. Results show that perfusion-based ER-fMRI accurately depicts the activation in Broca's area. Average changes in regional relative cerebral blood flow reached a maximum value of 30.7% at approximately 6.5 s after the start of stimulation and returned to 10% of the maximum value at approximately 12.8 s. Our results show that perfusion-based ER-fMRI is a useful tool for cognitive neuroscience studies, providing comparable temporal resolution and better localization of brain function than BOLD ER-fMRI.

Adult↗
PubMed2000

A case-controlled study on the use of HBsAg-positive donors for allogeneic hematopoietic cell transplantation.

To compare the clinical and serological outcomes of patients receiving donors' marrow positive or negative for hepatitis B surface antigen (HBsAg), we studied 18 patients of allogeneic hematopoietic cell transplantation receiving HBsAg-positive marrow (group 1) and 18 receiving HBsAg-negative marrow (group 2). The recipients of the 2 groups were matched for hepatitis B virus (HBV) serology, sex, age, underlying hematological diseases, conditioning regimen, and prophylaxis against graft-versus-host diseases. Eight (44.4%) recipients in group 1 and 2 (11.1%) in group 2 suffered from HBV-related hepatitis posttransplant (P =.03). Furthermore, HBV-related hepatic failure was seen in 6 group 1 patients, but in none of the group 2 patients (P =.007). Five of the 9 (55.5%) HBsAg-negative recipients in group 1 became positive after receiving HBsAg-positive marrow. Serum HBV DNA was positive in all 5 donors of these patients, but in none of the donors of recipients who remained HBsAg negative (P =.008). Group 1 patients developing HBV-related hepatitis posttransplant were more likely to have a donor carrying a precore A(1896 )and/or core promoter T(1762)/A(1764) HBV variant (62. 5% versus 0%, P =.007). This study has demonstrated that a high incidence of HBV-related hepatitis was associated with the use of HBsAg-positive marrow for transplant, and a high viral load in the donor appeared to predispose recipients to the development of HBV-related hepatitis posttransplant. Further clinical trials will be necessary to determine the optimal management approach to this problem, including the use of the antiviral agents in the donors and the recipients. (Blood. 2000;96:452-458)

Adolescent↗
PubMed2000

Coexpression of nestin in neural and glial cells in the developing human CNS defined by a human-specific anti-nestin antibody.

The presence of the intermediate filament protein nestin has been the predominant marker used to describe stem and progenitor cells in the mammalian CNS. In this study, a 998-bp fragment in the 3' region of the nestin mRNA was cloned from human fetal brain cells (HFBC). The nucleotide sequence of the cloned cDNA revealed 21 differences with the previously published human nestin sequence, resulting in 17 amino acid changes. A 150-amino-acid fragment derived from the cloned nestin cDNA was coupled to glutathione S-transferase and used as an immunogen to generate a rabbit polyclonal antiserum that selectively detects human nestin. HFBC that proliferated in response to basic fibroblast growth factor incorporated 5-bromo-2'-deoxyuridine into their nuclei and immunostained for nestin, indicating nestin expression in proliferating CNS progenitor cells. In all cell cultures, nestin costained with the neuroepithelial cell marker vimentin. A small subset of nestin-stained cells (1-2%) immunostained with neuronal marker MAP-2 during the first week and after 4 weeks in culture. However, during the first week in culture, approximately 10-30% of the total cell population of HFBC stained for the glial cell marker GFAP, and nearly all coimmunostained for nestin. After 4 weeks in culture, a subset of GFAP-positive cells emerged that no longer costained with nestin. These results describe nestin expression not only in CNS progenitor cells but also in the cells which were in transition from a progenitor stage to glial differentiation. Collectively, these data suggest a differential temporal regulation of nestin expression during glial and neuronal cell differentiation.

Amino Acid Sequence↗
PubMed2000

Hydrogen peroxide-induced oxidative damage and apoptosis in cerebellar granule cells: protection by Ginkgo biloba extract.

The ability of oxidative stress to induce apoptosis and the protective effects of Ginkgo biloba extract (EGb761) against this induction were studied in cultures of rat cerebellar granule cells. Cells were exposed to oxidative stress by treatment with 50 microm hydrogen peroxide+100 microm ferrous sulphate which generates hydroxyl radicals by Fenton reaction. Both morphological observation and biochemical analysis revealed that H(2)O(2)/FeSO(4)treatment induced apoptotic cell death in cerebellar granule cells, which was characterized by chromatin condensation and DNA fragmentation. During this process, the fluidity of the cell membrane decreased markedly, and the conformation of membrane proteins altered significantly. Pretreating cerebellar granule cells with the antioxidant EGb761 (Ginkgo biloba extract) effectively attenuated oxidative damage induced by H(2)O(2)/FeSO(4), and prevented cells from apoptotic cell death. The results suggested that EGb761 might be used as a potential drug for neuronal diseases associated with the excessive production of reactive oxygen species.

Animals↗
PubMed2000

Maternal serum ferritin and fetal growth.

OBJECTIVE: To determine the relationship between maternal serum ferritin and concentrations and specific types of fetal growth restriction (FGR). METHODS: Serum ferritin concentrations were measured at approximately 25 and 36 weeks' gestation in 480 multiparas with singleton fetuses who participated in a study of risk factors for repeated FGR. Asymmetric FGR was defined by low birth weight for gestational age criteria and a ponderal index less than 2.32, and symmetric FGR was defined by the same birth weight for gestational age criteria and a ponderal index of at least 2.32. RESULTS: Among 480 infants, 370 were appropriate for gestational age (AGA), 58 had asymmetric FGR, and 52 had symmetric FGR. Higher ferritin concentrations were associated with black race, maternal age 25 years or older, and smoking. Mothers of asymmetric-FGR infants had higher mean ferritin levels than mothers of AGA infants at 25 weeks' (38.0 versus 20.2 microg/L, P < .01) and 36 weeks' gestation (21.0 versus 13.3 microg/L, P < .01), whereas mothers of symmetric-FGR infants had significantly lower ferritin levels at 36 weeks (8.3 microg/L). For mothers with serum ferritin levels of at least 26 microg/L (highest quartile at 25 weeks), the adjusted odds ratio (OR) for asymmetric-FGR infants was 3.4, 95% confidence interval (CI) 1.6, 7.2. There was a similar association between the highest quartile of serum ferritin at 36 weeks (at least 20 microg/L) and asymmetric FGR (adjusted OR 2.7, 95% CI 1.3, 5.8). Women with serum ferritin levels less than 3 microg/L (lowest quartile at 36 weeks) had an adjusted OR for symmetric-FGR infants of 2.2, 95% CI 1.01, 4.6. CONCLUSION: High maternal serum ferritin levels are associated with asymmetric FGR, whereas low serum ferritin levels are associated with symmetric FGR.

Embryonic and Fetal Development↗
PubMed2000

Combination therapy with lamivudine and famciclovir for chronic hepatitis B-infected Chinese patients: a viral dynamics study.

In vitro studies have shown that lamivudine and penciclovir (the active metabolite of famciclovir) act synergistically to inhibit hepatitis B virus (HBV) replication. We compared the effectiveness of HBV viral suppression by lamivudine monotherapy versus lamivudine plus famciclovir combination therapy in Chinese patients with chronic HBV infection. Twenty-one Chinese hepatitis B e antigen (HBeAg)-positive patients, with detectable HBV DNA (Digene Hybrid Capture II), were randomized to receive either lamivudine 150 mg/d orally (group 1, 9 patients) or lamivudine 150 mg/d plus famciclovir 500 mg 3 times a day orally (group 2, 12 patients) for 12 weeks, with a follow-up period of at least 16 weeks. Serial serum HBV-DNA levels were determined and a mathematical model with provision for incomplete inhibition of virus production during therapy was applied to analyze the dynamics of viral clearance. The mean antiviral efficacy was significantly greater in group 2 than in group 1 (0.988 +/- 0.012 vs. 0.94 +/- 0.03, P =.0012). HBV DNA returned to pretreatment level within 16 weeks after the end of initial treatment in 4 patients (66.7%) in group 1 and none in group 2 (P =.08), who remained HBeAg positive and received no further treatment after week 12. Hence, in Chinese chronic HBeAg-positive patients, combination therapy using lamivudine and famciclovir was superior to lamivudine monotherapy in inhibiting HBV replication. Further studies of longer duration are needed to define whether combination therapy will increase the HBeAg seroconversion rate and decrease the rate of emergence of lamivudine-resistant variants.

2-Aminopurine↗
PubMed2000

Delta 469 mutation in the type 3 repeat calcium binding domain of cartilage oligomeric matrix protein (COMP) disrupts calcium binding.

Cartilage oligomeric matrix protein (COMP/TSP5), a large glycoprotein found in the territorial matrix surrounding chondrocytes, is the fifth member of the thrombospondin (TSP) gene family. While the function of COMP is unknown, its importance is underscored by the finding that mutations in the highly conserved type 3 repeat domain causes two skeletal dysplasias. Pseudoachondroplasia (PSACH) and Multiple Epiphyseal Dysplasia, Fairbanks type (EDM1). The type 3 repeats are highly conserved low-affinity Ca(2+)binding domains that are found in all TSP genes. This study was undertaken to determine the effects of mutations on calcium binding and structure of the type 3 repeat domains. Wild-type (WT) and Delta469 recombinant COMP (rCOMP) proteins containing the entire calcium-binding domain were expressed in E. coli and purified. Equilibrium dialysis demonstrated that WT bound 10-12 Ca(2+)ions/molecule while Delta469 bound approximately half the Ca(2+)ions. Circular dichroism (CD) spectrometry had striking spectral changes for the WT in response to increasing concentrations of Ca(2+). These CD spectral changes were cooperative and reversible. In contrast, a large CD spectral change was not observed at any Ca(2+)concentration for Delta469. Moreover, both WT and Delta469 proteins produced similar CD spectral changes when titrated with Zn(2+), Cu(2+)and Ni(2+)indicating that the Delta469 mutation specifically affects only calcium binding. These results suggest that the Delta469 mutation, in the type 3 repeat region, interferes with Ca(2+)binding and that filling of all Ca(2+)binding loops may be critical for correct COMP protein conformation.

Amino Acid Sequence↗
PubMed2000

[Dynamic changes of hepatitis B virus during treatment with lamivudine versus lamivudine plus famciclovir].

OBJECTIVE: To study whether combination therapy with lamivudine (LAM) and famciclovir (FCV) is effective for treatment of Chinese chronic HBV infection. METHODS: Chronic hepatitis B-infected patients treated with either LAM (n=9, 150 mg daily for 12 weeks) or LAM plus FCV (n=12, 150 mg LAM daily plus 500 mg FCV daily for 12 weeks). Serial serum HBV DNA were determined. A mathematical model was applied to analyze the dynamics of viral clearance. RESULTS: HBV clearance from patients treated with LAM was biphasic attenuation with mean antiviral efficacy of 0.94 while a combination therapy with LAM and FCV displayed an increased mean antiviral efficacy of 0. 988. There was an increased magnitude of the first phase of clearance from 1.1 log(10) to 1.9 log(10). Mean log(10) HBV viral decline were 1.8A0.2 for LAM treated group and 2.5A0.8 for combination group. CONCLUSION: Combination therapy of LAM and FCV has higher efficacy than LAM alone in suppressing HBV replication in Chinese chronic HBeAg-positive carriers.

2-Aminopurine↗
PubMed2000

Progressive multifocal leukoencephalopathy: JC virus induced demyelination in the immune compromised host.

Progressive multifocal leukoencephalopathy (PML) is a fatal demyelinating disease of the central nervous system that predominantly affects immunocompromised individuals. The etiologic agent, JCV, is a widespread polyomavirus with a very specific target, the myelin-producing oligodendrocytes of the brain. During periods of immune suppression, the virus can be reactivated from lymphoid tissues and kidney, causing targeted myelin destruction and corresponding neurological deficits. The incidence of PML has increased in recent years, due in large part to the advent of AIDS and the growing number of immunodeficient individuals. Furthermore, previous serological studies have shown that greater than 80% of the human population has antibodies to JCV in circulation. When combined, these statistics highlight an increasing need to establish effective treatment regimens for infected individuals as well as strategies to identify those at risk for developing PML.

Demyelinating Diseases↗
PubMed2000

Demonstration of the medullary lamellae of the human red nucleus with high-resolution gradient-echo MR imaging.

BACKGROUND AND PURPOSE: The human red nucleus is not a uniform structure. It is composed of caudally located magnocellular and rostrally located parvicellular subnuclei. In fact, the latter forms the bulk of the human red nucleus and can be subdivided histologically by two medullary lamellae into three parts. Because iron is deposited in the human red nucleus and gradient-echo sequences are more sensitive than spin-echo sequences in the detection of iron, a high-resolution gradient-echo MR sequence was used in this study to determine whether the medullary lamellae of the normal human red nucleus could be detected in vivo. METHODS: Ten healthy volunteers (seven men and three women, 27-48 years old) were examined with a high-resolution T2-weighted gradient-echo MR sequence using a 1.9-T MR imager. The scanning parameters were 60/40/15 (TR/TE/excitations) with a flip angle of 20 degrees , a pixel size of 1 x 1 mm, and a slice thickness of 5 mm. RESULTS: The medullary lamellae were depicted in all subjects in three imaging planes: coronal, oblique axial, and oblique sagittal. The signal intensity of the lamellae was consistently higher than that of other parts of the red nucleus on all images. With the lamellae, the parvicellular subnucleus of the human red nucleus can be divided into its subdivisions. CONCLUSION: High-resolution gradient-echo MR imaging is capable of depicting the medullary lamellae of the normal human red nucleus in vivo.

Adult↗
PubMed2000

Interactive medical data on demand: a high-performance imaged-based approach across heterogeneous environments.

Medical data in image format continues to increase in both size and complexity. We have integrated advanced techniques in visualization, networked computing, and interface design to improve methods for accessing medical data comprising high-resolution images for reconstructions into three-dimensional volumetric representations. We present two approaches to handle the range of low to high-end client platforms, support visualization functionality, and provide the ability to manipulate very large data over heterogeneous computing and networking environments. We present examples of its use for clinical, research, and educational purposes and discuss future extensions.

Computer Communication Networks↗
PubMed2000

The stress hormone, cortisol, synergizes with HIV-1 gp-120 to induce apoptosis of normal human peripheral blood mononuclear cells.

Both quantitative and qualitative defects in immune functions in patients with AIDS may result from induction of programmed cell death or apoptosis of CD4 T lymphocytes. We postulate that neurohormones may interact with gp-120 that is shed during active HIV infection and cause apoptosis of immunocompetent cells leading to immunopathogenesis of HIV infections. In this study, we investigated the synergistic effect of cortisol plus HIV gp-120 in inducing apoptosis of lymphocytes from normal subjects. Total peripheral blood mononuclear cells and isolated CD4+ T-cells were treated with cortisol or gp-120 separately and in combination and RNA and DNA were extracted. RNA was reverse transcribed and amplified with specific primers for Fas and Fas ligand and analyzed on agarose gels. DNA was analyzed by gel electrophoresis for ladder formation, the hallmark for apoptosis, and Fas antigen expression by confocal microscopy. Results demonstrate that cortisol and gp-120 induce apoptosis of lymphocytes from normal donors as demonstrated by DNA ladder formation, TUNEL staining and Fas gene expression. Concentrations of cortisol and gp-120 that did not produce apoptosis when used separately, induced significant apoptosis when used in combination. Further, gp-120 induced DNA fragmentation was significant in the CD4+ T-cell subpopulation compared to the CD47 subpopulation. This study suggests that the stress-associated neurohormone, cortisol, synergizes with HIV peptides in causing apoptosis of normal lymphocytes. The synergistic effect of cortisol and gp- 120 in inducing apoptosis of lymphocytes is consistent with a model proposing that stress-associated and circulating HIV-1 derived soluble products may cause progression of HIV infections.

Apoptosis↗
PubMed2000

[Polarized populations of T helper cells in patients with chronic hepatitis B virus infection].

OBJECTIVES: To investigate the composition of Th1/Th2/Th3 cells in chronic HBV-infected individuals by determining the expression of IL-4/IFN-gamma/TGF-beta in single CD4+ T cell isolated from the peripheral blood mononuclear cells (PBMCs), and analyze the role of Th cells polarized population in chronic HBV-infection. METHODS: PBMCs from chronic HBV infected individuals were separated routinely, stimulated by PMA/Ionomycin/Monensin, and the production of IL-4/IFN-gamma/TGF-beta by CD4+ T cells in PBMCs was determined by FACS analysis. RESULTS: The percentage of IFN-gamma-producing T cells, IL-4-producing T cells and TGF-beta producing T cells ranged from 2.3%-18.6%, 1.1%-8.7% and 0.7%-7.1%, respectively, in CD4+ cells from non-infected individuals. The majority of CD4+ T cells from PBMCs in chronic HBV-infected individuals were Th0 cells. The proportion of Th1 cells increased significantly with the hepatic inflammation activity, and the proportion in active period of chronic hepatitis B was higher than that in nonactive period (P < 0.05). The percentage of Th2 cells in CD4+ T cells from HBV-infected individuals did not differ significantly (P > 0.05), but it was higher than controls (P < 0.05). The percentage of Th3 cells in CD4+ T cells from AsC group was higher than that in CHB group and control (P < 0.05). CONCLUSIONS: Th1 phenotype cytokine are correlated with hepatic inflammation activity of chronic hepatitis B. Th2 cells may be associated with the persistence of HBV infection. Th3 cells cooperating with Th2 cells exert negative immunoregulating action and may be associated with the immune tolerance state of chronic HBV infection.

Adolescent↗
PubMed2000

[Cloning and expression of TTV gene fragment in E. coil and identification of the expressed protein].

OBJECTIVE: To construct a recombinant expression vector containing TTV gene fragment and identify the expressed protein. METHODS: Based on computer-aided studies, TTV ORF12 gene fragment coding protein of antigenicity was amplified by PCR from the patient serum with non-A-G hepatitis. Then the gene fragment was integrated into the multiple cloning site of pQE-30 and expressed in E coil. The expressed protein was identified by ELISA. RESULTS: The relative molecular weight of the expressed protein matches the predication and its yield was up to 22.33% of total bacterial proteins of E. coli The expressed protein was detected by ELISA. CONCLUSIONS: The recombinant vector has been constructed successfully and the expressed protein possesses antigenicity.

Adolescent↗
PubMed2000

Deletion of chromosomes 9p and 17 associated with abnormal expression of p53, p16/MTS1 and p15/MTS2 gene protein in hepatocellular carcinomas.

OBJECTIVE: Fifteen loci on chromosome 9p and 17 were analyzed to clarify the involvement of loss of heterozygosity (LOH) in hepatocellular carcinoma (HCC) in Chinese patients positive for hepatitis B (HBV) and/or hepatitis C (HCV) infection. Expression of tumor suppressor genes (TSG) of p53, p16, and p15 gene was found to correlate with a deletion of these genes. METHODS: Immunohistochemistry and PCR-based microsatellite polymorphism analysis techniques were used. RESULTS: A high frequency of LOH was detected on chromosome 9p24 at locus D9S54 (61.8%) and 9p21, concentrated at loci D9S1747 (52.4%) and D9S1752 (51.8%). On chromosome 17, high frequent LOH was concentrated on 17p at the p53 gene locus (53.8%) and locus D17S520 (52.8%). p53 protein expression was increased in HCC, which correlated with p53 gene loss. Expression of p16 and p15 protein decreased in HCC when LOH occurred at locus D9S1752 (p15 gene locus) or at locus D9S1747 and D9S1748 (p16 gene is located between these 2 loci). LOH at the p53 gene and p15 gene loci was closely associated with HBV and HCV co-infection in HCC. No significant relationship between LOH and HCC clinico-pathological outcomes was observed. CONCLUSION: High frequency LOH occurs on chromosomes 9p and 17 in HCC in Chinese patients. Such sites may contain several putative tumor suppressor genes critically involved in the development and/or progression of HCC. Deletion of p53, p16, or p15 tumor suppressor genes may cause abnormal expression of the protein product of these genes. HBV and/or HCV infection may be closely associated with LOH p53 and/or p15 gene expression.

Adult↗