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Biomedical subjects

Y Chang

Publications and source records attributed to Y Chang.

At least 199 records · Page 11Linked to original sources

[Effects of gallbladder ruptured under laparoscopic cholecystectomy on pulmonary function].

To assess effects of gallbladder ruptured and bile running out under laparoscopic cholecystectomy on pulmonary function, we preprospectively studied 20 patients without gallbladder rupture (group A), 10 with gallbladder rupture (group B), and 10 open cholecystectomy (group C). Significant differences were found in the group B and C to all pulmonary function values compared with preoperative values until the 5th to 7th postoperative day (P < 0.05). The group A showed only a significant difference on the first day after operation (P < 0.05). There are no significant differences between groups B and C. Comparing the group A with the group B and C respectively showed a significant differences from the 1st to 7th day (P < 0.05). This study confirms that the group A is superior to the groups B and C. Postoperative peritonitis is also an important cause of pulmonary dysfunction to reduce small airway function. Performing LC, we should try to avoid rupture of gall bladder or hemorrhage to fasten the recovery of patients' pulmonary function and reduce the chance of pulmonary complications.

Cholecystectomy↗

[Comparison of total N-nitrosamides in fasting gastric juice from subjects in high and low risk areas for gastric cancer].

OBJECTIVE: The status of human exposure to N-nitrosamides (NAD) is almost unknown, although they are probably carcinogenic to human stomach. This study is to elucidate the relationship between NAD exposure and causes of gastric carcinomas (GC). METHODS: The total amount of natural NAD was detected with a photohydrolysis-TEA method (184 nmole/l, detection limit) in fasting gastric juice samples from subjects aged 35-68 by fibroendoscope both in a high and low risk area for GC with the same geographical and socioeconomic conditions in Shangdon Province, China. RESULTS: A) More NAD-positive samples in the high risk area (Linqu County, n = 176) were observed than in the low risk area (Chongshan County, n = 99), the difference was significantly after age-adjustment (40.9% vs. 30.3%, P = 0.0324). B)84% of samples was pH < or = 3 in Chongshan, whereas only 48% in Linqu (P < 0.001). In the acidic samples more NAD-positive ones in Linqu were found than in Chongshan (46.2% vs 27.4%, P < 0.01). NAD-positive rate was higher in samples with pH > or = 5 than those with pH < or = 3 only in the low but not in the high risk area. C)NAD-positive rate was also higher in samples from subjects with chronic atrophic gastritis (CAG) with or without dysplasia than those from normal subjects and from those with superficial gastritis or CAG with intestinal metaplasia both in the high and low risk areas. CONCLUSION: The results suggest that human endogenous exposure to NAD in the high risk area for GC be higher than that in the low risk area; CAG and dysplasia may play a role in human gastric carcinogenesis by N-nitrosamides.

Adult↗

[Discovery of a novel reassortant H1N2 influenza virus].

Three strains of influenza A virus were isolated from patients suffering from influenza like disease in Railway Hygiene and Anti-epidemic Station of Taiyuan in January 1996. The identification results by serological method indicated that the isolates were different from H1N2 subtype of influenza A virus isolated from men in 1989 and 1992 and that their HA antigenicity was similar to that of A/RP/8/34 (H1N1) virus, but distinguishable from that of influenza A (H1N1) virus circulating in mans recently. The comparison of migration patterns of the RNA among the isolates, the A/PR//34 (H1N1) and the A/Wuhan/359/95 (H3N2) viruses revealed that the migration patterns of RNA 1-4 segments of the isolates were similar to those of A/PR/8/34 (H1N1) virus, but those of RNA 5-6 segments were indistinguishable from those of A/Wuhan/359/95 (H3N2) strain. However, the migration patterns of RNA 7-8 segments of the isolates were not only different from those of A/PR/8/34 (H1N1) virus, but also distingrasgable from those of A/Wuhan/359/95 (H3N2) strain. Therefore, it could be considered that the isolates were a novel reassortant H1N2 influenza A virus.

Adolescent↗

[Detection of minimal residual disease after allogeneic bone marrow transplantation in chronic myeloid leukemia].

OBJECTIVE: To detect minimal residual disease (MRD) after allogeneic bone marrow transplantation (allo-BMT) in chronic myeloid leukemia (CML). METHODS: M-bcr/abl mRNA was assayed by reverse transcriptase polymerase chain reaction (RT-PCR) in bone marrow cells from 46 successfully sibling marrow engrafted CML patients. RESULTS: About 70% of the patients achieved genetic complete remission in 3 months post allo-BMT. Four patients were M-bcr/abc mRNA positive at 1.5 to 2 months post allo-BMT and turned to be negative at 3 to 9 months post allo-BMT. One patient was still M-bcr/abl(+) after disease-free survival(DFS) for more than 6 years, while another one was M-bcr/abl(-) after DFS for more than 4 years. CONCLUSION: RT-PCR is so far the most sensitive method for MRD detection in CML, but its limitation should not be ignored.

Adolescent↗

Assessment of an epoxy-fixed pericardial patch with or without ionically bound heparin in a canine model.

In this study, an epoxy-fixed porcine pericardial patch with or without ionically bound heparin was evaluated in a canine model as an alternative to the glutaraldehyde-fixed biological patch for clinical applications. To evaluate the effectiveness of this epoxy-fixed patch, a composite membrane composed of: an epoxy-fixed porcine patch with ionically bound heparin; a glutaraldehyde-fixed porcine patch with ionically bound heparin; an ePTFE polymeric patch; a polyester polymeric patch; an epoxy-fixed porcine patch without ionically bound heparin; and a glutaraldehyde-fixed porcine patch without ionically bound heparin was made. This membrane was assessed orthopically in a canine model. The early results (1 approximately 4 weeks post implant) revealed that the biological patches with ionically bound heparin had the mildest tissue reactions (inflammatory reaction, fibrosis, and adhesion) among all the test samples. However, by 12 weeks postoperatively, all the test samples had mild to severe tissue reactions. The order of tissue reactions with increasing severity was: the biological patches with ionically bound heparin, the biological patches without ionically bound heparin, and the polymeric patches. The results suggest that heparin may be used to reduce adhesion. Additionally, the epoxy-fixed tissue caused a relatively lower degree of inflammatory reaction than the glutaraldehyde-fixed tissue.

Analysis of Variance↗

Improved postoperative pain relief via preemptive analgesia in relation to heart rate variability for coronary artery bypass grafting: a preliminary report.

BACKGROUND: Sudden cardiac death remains to be the most devastating outcome for patients who undergo cardiac surgery. Surgical stress in combination with postoperative pain are key factors of such tragedy. Preemptive analgesia (PA) is supposed to provide optimal postoperative pain management, and epidural morphine infusion to provide effective pain relief and stress reduction after cardiac surgery. Heart rate (HR) variability seems to correlate to the survival of acute myocardial infarction (AMI) patients. This study was conducted to evaluate the benefits of PA for coronary artery bypass grafting (CABG) patients in the sense of improvement in postoperative respiratory and cardiovascular functions, and its correlation to HR and HR variability. METHODS: A total of 40 patients who underwent CABG from June 1995 to December 1995 were randomly selected and divided into two groups (Group A and Group B). Group A (n = 20) was treated with conventional postoperative analgesia of intravenous (i.v.) meperidine HCl (Demerol). Group B (n = 20) was treated with PA using epidural infusion of local anesthetics plus ketamine and morphine during surgery and then using intermittent epidural morphine infusion for postoperative pain control when necessary, and Demerol was given intravenously as in group A. Postoperative pain intensity was measured by a modified visual analogue pain scale from 0 to 10 (0 = no pain, 10 = severe pain). Perioperative HR and HR variability data based on 24-hour electrocardiograph (ECG) Holter monitoring along with data on respiratory and cardiovascular functions were gathered, analyzed, and compared between Group A and Group B. RESULTS: Effective analgesia (mean pain score of 0-2) was achieved in 50% of Group A patients and 75% of Group B patients. Group B with the reduced dosage of demerol also had the benefits of smaller degree of respiratory insufficiency, earlier extubation, and less incidence of re-intubation as compared with Group A. For HR comparison between Group A and Group B, statistically significant differences (p < 0.05) were observed in 3 out of the 16 postoperative time segments. For HR variability comparison between Group A and Group B, statistically significant difference (p < 0.05) was observed in one of the time segments while another segment showed marginal significance (p = 0.061). Group B patients also maintained better overall respiratory and cardiovascular functions. CONCLUSIONS: PA method through the use of epidural anesthesia along with morphine infusion provided better postoperative pain relief and more stable respiratory and cardiovascular functions in our patients with cardiac surgery. Although the differences in HR and HR variability between the control and the PA groups were not statistically significant throughout the period studied, the potential benefits of better understanding the relationship between postoperative pain control and HR variability justify further studies to be conducted.

Aged↗

Surgical repair of Ebstein's anomaly.

BACKGROUND: Ebstein's anomaly represents a congenital structural deformity of the tricuspid valve associated with a wide spectrum of morphologic and physiologic abnormalities. Valvuloplasty and tricuspid valve replacement are the main surgical treatments. Plication of the atrialized right ventricle and valvuloplasty of the tricuspid valve can achieve satisfactory clinical results. Two surgical techniques, known as Danielson's and Quaegebeur's methods, are often used clinically. This study was conducted to compare the postoperative results between both methods in treatment of Ebstein's anomaly. METHODS: Valvuloplasty of tricuspid valve and the plication of atrialized right ventricle were performed in 8 out of 17 patients with Ebstein's anomaly in our hospital from January 1986 to August 1996. Danielson's method was used in six of eight patients, and Quaegebeur's method was used in the remaining two patients. There were three males and five females, aged from 8 months to 61 years (mean: 14.1 years). RESULTS: All patients achieved clinical improvement in cardiothoracic ratio and heart functional class. Cardiac arrhythmia was the likely cause of death in two patients treated by Danielson's method, and one patient developed complete atrioventricular (A-V) block postoperatively. By Quaegebeur's method, all patients survived, but a permanent pacemaker was implanted for both patients due to their preoperative complete A-V block. CONCLUSIONS: Both methods achieved satisfactory postoperative results. However, Quaegebeur's method seems to be more effective because it provided a simultaneous reconstruction of both tricuspid valve and right ventricle without the need for additional excision of the right atrium.

Adolescent↗

Expression of a virus-derived cytokine, KSHV vIL-6, in HIV-seronegative Castleman's disease.

Castleman's disease is a rare B cell lymphoproliferative disorder related to excess interleukin-6 (IL-6)-like activity. Kaposi's sarcoma-associated herpesvirus (KSHV or HHV8), which encodes a functional cytokine (vIL-6), has been found in some patients with Castleman's disease. Lymph nodes from 14 HIV-seronegative Castleman's disease patients were compared to hyperplastic lymph nodes from 25 HIV-seronegative patients as well as Kaposi's sarcoma lesions from 48 patients for KSHV infection and vIL-6, human IL-6, and Epstein-Barr virus EBER expression. While all Kaposi's sarcoma tissues examined were polymerase chain reaction-positive and all control lymph nodes were polymerase chain reaction-negative for KSHV, none had detectable vIL-6 expression. Six of 14 (43%) Castleman's tissues were positive for KSHV by polymerase chain reaction and all 6 had evidence of vIL-6 expression by immunohistochemistry. vIL-6-positive Castleman's disease patients generally had the multicentric plasma cell variant form of the disease and had a rapidly fatal clinical course frequently associated with autoimmune hemolytic anemia and gammopathy. In contrast, 7 (88%) of the 8 vIL-6-negative Castleman's disease patients had localized disease and have remained disease-free after therapy. KSHV vIL-6 expression appears to be limited to hematopoietic cells and is not present in Kaposi's sarcoma spindle cells. These data suggest that Castleman's disease is a syndrome of multiple etiologies involving aberrant IL-6 activity from either endogenous or viral sources.

Adolescent↗

The association of Helicobacter pylori with intestinal type gastric adenocarcinoma in a Hawaii population.

American-Japanese in Hawaii with gastric cancer have characteristics intermediate to those in Japan and the mainland United States. Japanese and mainland U.S. studies have found Helicobacter pylori is associated with intestinal type gastric adenocarcinoma. The present Hawaii study confirmed this association which is independent of Japanese race (27.6% intestinal type and 4.5% diffuse type were H. pylori positive, p = 0.031, n = 80).

Adenocarcinoma↗

Nucleotide sequence of the Kaposi sarcoma-associated herpesvirus (HHV8).

The genome of the Kaposi sarcoma-associated herpesvirus (KSHV or HHV8) was mapped with cosmid and phage genomic libraries from the BC-1 cell line. Its nucleotide sequence was determined except for a 3-kb region at the right end of the genome that was refractory to cloning. The BC-1 KSHV genome consists of a 140.5-kb-long unique coding region flanked by multiple G + C-rich 801-bp terminal repeat sequences. A genomic duplication that apparently arose in the parental tumor is present in this cell culture-derived strain. At least 81 ORFs, including 66 with homology to herpesvirus saimiri ORFs, and 5 internal repeat regions are present in the long unique region. The virus encodes homologs to complement-binding proteins, three cytokines (two macrophage inflammatory proteins and interleukin 6), dihydrofolate reductase, bcl-2, interferon regulatory factors, interleukin 8 receptor, neural cell adhesion molecule-like adhesin, and a D-type cyclin, as well as viral structural and metabolic proteins. Terminal repeat analysis of virus DNA from a KS lesion suggests a monoclonal expansion of KSHV in the KS tumor.

Base Sequence↗

Molecular mimicry of human cytokine and cytokine response pathway genes by KSHV.

Four virus proteins similar to two human macrophage inflammatory protein (MIP) chemokines, interleukin-6 (IL-6), and interferon regulatory factor (IRF) are encoded by the Kaposi's sarcoma-associated herpesvirus (KSHV) genome. vIL-6 was functional in B9 proliferation assays and primarily expressed in KSHV-infected hematopoietic cells rather than KS lesions. HIV-1 transmission studies showed that vMIP-I is similar to human MIP chemokines in its ability to inhibit replication of HIV-1 strains dependent on the CCR5 co-receptor. These viral genes may form part of the response to host defenses contributing to virus-induced neoplasia and may have relevance to KSHV and HIV-I interactions.

Amino Acid Sequence↗

Body cavity-based malignant lymphoma containing Kaposi sarcoma-associated herpesvirus in an HIV-negative man with previous Kaposi sarcoma.

BACKGROUND: The role of Kaposi sarcoma-associated herpesvirus in the development of malignant lymphomas in patients negative for the human immunodeficiency virus (HIV) has not been established. OBJECTIVE: To examine the possible role of Kaposi sarcoma-associated herpesvirus in a case of body cavity-based malignant lymphoma that occurred in an HIV-negative patient who had previously had Kaposi sarcoma. DESIGN: Case study. SETTING: Academic medical center. PATIENT: A 94-year-old man with lymphomatous ascites. MEASUREMENTS: Polymerase chain reaction (PCR) and Southern blot DNA analysis. RESULTS: The body cavity-based lymphoma cells were positive for Kaposi sarcoma-associated herpesvirus by PCR and were negative for other herpesviruses, including Epstein-Barr virus, cytomegalovirus, and human herpesviruses 6 and 7. Southern blot analysis of lymphoma DNA showed high levels of Kaposi sarcoma-associated herpesvirus (> 40 to 80 genomes/cell). Clonal rearrangement of the immunoglobulin JH and JK genes was present, confirming the presence of a clonal B-cell proliferation. CONCLUSIONS: Kaposi sarcoma-associated herpesvirus may be involved in the development of malignant lymphoma after Kaposi sarcoma in HIV-negative patients. This type of lymphoma, in contrast to body cavity-based lymphoma related to the acquired immunodeficiency syndrome, may have an indolent clinical course.

Aged↗

Stoichiometry of a recombinant GABAA receptor.

GABA is the main inhibitory neurotransmitter in the mammalian brain. The postsynaptic GABAA receptor/pore complex is presumed to be a pentamer typically composed of a combination of alpha, beta, and gamma subunits, although the stoichiometry remains controversial. We probed the stoichiometry of the GABAA receptor by site-directed mutagenesis of a conserved leucine (to serine) in the putative second membrane-spanning domain of the rat alpha 1(alpha L263S), beta 2(alpha L259S), and gamma 2(alpha L274S) subunit isoforms. Coexpression of wild-type and mutant subunits of each class (e.g., alpha and alpha L263S), along with their wild-type counter-parts (e.g., beta and gamma), in Xenopus laevis oocytes resulted in mixed populations of receptors with distinct GABA sensitivities. This is consistent with the interpretation that the leucine mutation increased the GABA sensitivity in proportion to the number of incorporated mutant subunits. The apparent number of incorporated subunits for each class (alpha, beta, and gamma) could then be determined from the number of components comprising the compound GABA dose-response relationships. Using this approach, we conclude that the recombinant alpha 1 beta 2 gamma 2 GABAA receptor is a pentamer composed of two alpha subunits, two beta subunits, and one gamma subunit.

Amino Acid Sequence↗

Effect of economic reforms on child growth in urban and rural areas of China.

BACKGROUND: Beginning in 1978, China implemented economic reforms to transform the economy to a free-market system. We compared the effect of the reforms on the growth of children in urban and rural areas. METHODS: Using data from five large cross-sectional surveys conducted between 1975 and 1992, we examined the trends in height for age of children two to five years of age in urban and rural areas. Mean height for age was expressed as the height in centimeters adjusted to a reference value of 99.1 cm for a 42-month-old boy. RESULTS: Height increased before and during the economic reforms. In 1975, the average height of children in periurban rural areas was about 3.5 cm less than that of children in urban areas. Between 1975 and 1985, the average height of children in periurban rural areas increased by 2.0 cm, as compared with 1.3 cm in urban children. Between 1987 and 1992, the average height of both urban and rural children increased, but the net increase for rural children was only one fifth that for urban children (0.5 vs. 2.5 cm). In a 1990 survey of seven provinces, the rural mean height was 92.5 cm, as compared with the urban mean of 96.9 cm and the reference value of 99.1 cm; 38 percent of rural children had moderate stunting of growth and 15 percent had severe stunting, as compared with 10 percent and 3 percent of urban children, respectively. Differences in height between rural and urban children were greater in provinces in which the average height of children was lower. CONCLUSIONS: Despite an overall improvement in child growth during the economic reforms in China, the improvement has not been equitable, as judged by increased differences in height between rural and urban children and increased disparities within rural area.

Adolescent↗

Seroconversion to antibodies against Kaposi's sarcoma-associated herpesvirus-related latent nuclear antigens before the development of Kaposi's sarcoma.

BACKGROUND: If Kaposi's sarcoma-associated herpesvirus (KSHV) is the cause of Kaposi's sarcoma, serologic evidence of infection should be present in patients before the disease develops. METHODS: Using an immunoblot assay for two latent nuclear antigens of KSHV, we tested serum samples from homosexual male patients with the acquired immunodeficiency syndrome (AIDS) with and without Kaposi's sarcoma (HIV-infected men with hemophilia), HIV-seronegative blood donors, and HIV-seronegative patients with high titers of antibodies against Epstein-Barr virus (EBV). Serial serum samples obtained from patients with Kaposi's sarcoma before the diagnosis of the disease were tested for evidence of seroconversion. RESULTS: Of 40 patients with Kaposi's sarcoma, 32 (80 percent) were positive for antibodies against KSHV antigens by the immunoblot assay, as compared with only 7 of 40 homosexual men (18 percent) without Kaposi's sarcoma immediately before the onset of AIDS. Of 122 blood donors, 22 EBV-infected patients, and 20 HIV-infected men with hemophilia, none were seropositive. When studied by the immunoblot assay over a period of 13 to 103 months, 21 of the 40 patients with Kaposi's sarcoma (52 percent) seroconverted 6 to 75 months before the clinical appearance of Kaposi's sarcoma. The median duration of antibody seropositivity for KSHV-related latent nuclear antigens before the diagnosis of Kaposi's sarcoma was 33 months. CONCLUSIONS: In most patients with kaposi's sarcoma and AIDS, seroconversion to positivity for antibodies against KSHV-related nuclear antigens occurs before the clinical appearance of Kaposi's sarcoma. This supports the hypothesis that Kaposi's sarcoma results from infection with KSHV.

Acquired Immunodeficiency Syndrome↗