Biomedical subjects

L Shi

Publications and source records attributed to L Shi.

At least 199 records · Page 11Linked to original sources

PubMed1997

Nitrogen assimilation in alfalfa: isolation and characterization of an asparagine synthetase gene showing enhanced expression in root nodules and dark-adapted leaves.

Asparagine, the primary assimilation product from N2 fixation in temperate legumes and the predominant nitrogen transport product in many plant species, is synthesized via asparagine synthetase (AS; EC 6.3.5.4). Here, we report the isolation and characterization of a cDNA and a gene encoding the nodule-enhanced form of AS from alfalfa. The AS gene is comprised of 13 exons separated by 12 introns. The 5' flanking region of the AS gene confers nodule-enhanced reporter gene activity in transformed alfalfa. This region also confers enhanced reporter gene activity in dark-treated leaves. These results indicate that the 5' upstream region of the AS gene contains elements that affect expression in root nodules and leaves. Both AS mRNA and enzyme activity increased approximately 10- to 20-fold during the development of effective nodules. Ineffective nodules have strikingly reduced amounts of AS transcript. Alfalfa leaves have quite low levels of AS mRNA and protein; however, exposure to darkness resulted in a considerable increase in both. In situ hybridization with effective nodules and beta-glucuronidase staining of nodules from transgenic plants showed that AS is expressed in both infected and uninfected cells of the nodule symbiotic zone and in the nodule parenchyma. RNA gel blot analysis and in situ hybridization results are consistent with the hypothesis that initial AS expression in nodules is independent of nitrogenase activity.

Adaptation, Physiological↗

PubMed1997

Human TAP1 polymorphisms detected by denaturing gradient gel electrophoresis.

Presentation of endogenous peptides by major histocompatibility complex class I (MHC) molecules is controlled, in part, by the Tap1 and Tap2 genes in the MHC class II region that encode a heterodimeric peptide transporter. Polymorphisms of human Tap1 in normal individuals have now been investigated systematically by denaturing gradient gel electrophoresis (DGGE) analysis of fragments of genomic DNA generated by the polymerase chain reaction. Polymorphisms identified by distinctive DGGE band patterns were confirmed by DNA sequencing. In addition to four previously described polymorphisms in the open reading frame, DGGE detected three new polymorphisms: a G-->T substitution in the promoter region, a 10-bp insert in intron 9, and a G-->T substitution 80-bp downstream of the translation termination codon.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1997

Screening of the TAP1 gene by denaturing gradient gel electrophoresis in insulin-dependent diabetes mellitus: detection and comparison of new polymorphisms between patients and controls.

New protective or disease-associated polymorphisms in the TAP1 gene were sought in insulin-dependent diabetes mellitus (IDDM) patients with the use of denaturing gradient gel electrophoresis (DGGE) screening of genomic DNA. The TAP1 gene is located in the human leukocyte antigen (HLA) class II region of the genome and encodes components of a peptide transporter essential for antigen presentation by HLA class I molecules. Fragments of TAP1 corresponding to the 5' promoter, each of the 11 exons (with portions of adjacent intronic regions) and the 3' flanking region were amplified by the polymerase chain reaction and then subjected to DGGE. DNA fragments of TAP1 yielded DGGE bands with patterns whose frequencies differed between IDDM patients and controls. Specific DGGE band patterns with fragments corresponding to the promoter, exons or introns 3, 6, 7, 8, 9 or 10 of TAP1 were detected exclusively in either patients or controls. Sequencing of TAP1 fragments encompassing exon 7 gave rise to a DGGE band pattern exclusively observed in an IDDM patient and sequencing revealed a previously unidentified polymorphisms at codon 518 (GTC-->ATC, Val-->Ile). Another unique polymorphism uncovered by DGGE revealed by sequencing a polymorphism in intron 2 in a diabetic patient. The genotypes of additional HLA class II matched patients and controls were determined with regard to five exonic and one intronic TAP1 polymorphism. A 10 base pair intronic insertion in intron 9 was exclusively identified in controls and missing from patients (P = 0.017). Further large population-based studies may reveal whether these newly identified at risk or protective TAP1 variants confer markers of statistical risk in diverse population groups.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1997

Primary care physicians and barriers to providing care to persons with HIV/AIDS.

Primary care physicians play an increasingly important role in the care of persons with HIV/AIDS due to the rising number and changing geographic distribution of persons infected with HIV/AIDS. The study explored the relationship between barriers to health services and the experience and willingness of primary care physicians to care for persons with HIV/AIDS. The study was based on a random survey of primary care physicians in South Carolina. The results indicate that although primary care physicians' willingness to treat persons with HIV/AIDS is significantly associated with many self-reported barriers (i.e., financial, structural, knowledge, and attitudinal), their HIV/AID care experience was most significantly correlated with self-reported knowledge that overrides financial and structural barriers. The results emphasize the importance of programs and policy initiatives aimed at enhancing the primary care physicians' knowledge level and improving their attitudes related to HIV/AIDS.

Acquired Immunodeficiency Syndrome↗

PubMed1997

Health care spending, delivery, and outcome in developed countries: a cross-national comparison.

This study examines the trend of health care spending, availability and use of medical services, and aggregate health outcome of the 24 industrialized member countries of the Organization for Economic Cooperation and Development (OECD). Major differences between the United States and other OECD countries are highlighted and discussed. The results of the study demonstrate that, over the past four decades, the United States has been spending more and accomplishing less when compared with other industrialized nations. The United States needs to learn from the successful experience of other nations. Redesigning the system of health care delivery in the United States may be the only viable option to improve the quality of health care.

Aged↗

PubMed1997

Analyzing hospital market share along product lines.

This article illustrates a method of analyzing market share based on product lines or specific hospital services, using 1990 data from a health service catchment area in South Carolina. Hospital discharges from two specific services: vascular and cardiac surgery; and obstetrics, were used to compute market rates of retention, discharge, escape, commitment, opening, and capture. The results confirm that as hospitals become more specialized, market share analysis based on total discharges is often misleading. Rather, discharges should be disaggregated and separate service areas with different boundaries constructed for different product lines. This method of market analysis can be performed easily and periodically by hospitals to monitor the market situation of their product lines.

Catchment Area, Health↗

PubMed1997

African American administrators in community/migrant health centers.

Community and migrant health centers (CHC/MHCs) play a secondary role as avenues for the development of minority and women health care professionals, groups traditionally underrepresented in administrative and managerial positions within the health care system. This paper focuses on the role of CHC/MHCs in eliminating the barriers that typically limit the professional advancement of these groups. In a survey of both rural and urban CHC/MHC administrators, it was found that CHC/MHCs have higher percentages of minorities in top management positions than general management but do not necessarily reflect the minority composition of those being served. Of the CHC/MHC administrators, 20 percent were African American, less than the population served (31 percent) but greater than the percentage of African Americans in the general U.S. population (12 percent). This suggests that CHC/MHCs have partially met the original goal of upward mobility and that there is room for improvement.

Black or African American↗

PubMed1997

Underreporting and misclassification of maternal mortality in Taiwan.

BACKGROUND: Underreporting and misclassification of maternal deaths are universal. The purposes of this study were to quantify the level of underestimation of maternal mortality and to analyze possible factors that contribute to underreporting and misclassification of maternal mortality. METHODS: An interview census of all registered deaths that occurred during 1984-1988 in women of reproductive age was undertaken in Taiwan. Pregnancy-related deaths were screened from all collected questionnaires and death certificates by the researchers. The screened pregnancy-related deaths were then reviewed and evaluated by obstetrician-gynecologists; a cause of each death was assigned. RESULTS: For the five years, on average, the rate of underreporting of maternal mortality is 58.38% and the correct/confirmed rate of classification is 53.28%. Underreported and misclassified maternal deaths are more likely for women aged 20-24, with stillbirth and fetal death, care sought for non-obstetric reasons, care received in private hospitals and clinics, occurrence in the home, certification by non-obstetrician-gynecologists and court doctors, and death from non-obstetric causes. CONCLUSIONS: This study shows the limitations of official vital registration and concludes that dependence on death certificates alone to identify maternal deaths is incomplete and incorrect.

Adult↗

PubMed1997

[Preliminary study on pathophysiological basis of liver-blood deficiency syndrome].

By ways of HPLC and RIA, multiple laboratory parameters were determined simultaneously in 84 patients of iron--deficiency anemia (IDA) or chronic aplastic anemia (CAA) with Liver-Blood Deficiency Syndrome (LBDS) diagnosed by differentiation of TCM. The results showed that LBDS had some pathophysiological characteristics such as decreased function of sympathicus and adrenal medulla axis, increasing of L-EK, lower energy metabolism of erythrocyte, lower rate of body metabolism, sodium and water imbalance, and abnormalities in hemorrheology and erythrocyte deformability. It is suggested that the patients with LBDS are in a state of protective compensation in blood volume regulation.

Adolescent↗

PubMed1997

How well trained are nursing home administrators?

Nursing home administrators represent wide variations in academic training. General education levels do not seem to affect administrative preparation in key domains of practice--specific academic fields of study are more relevant. Hence, sole emphasis on higher educational requirements for licensure appears to be a misdirected strategy for improving quality of care and enhancing management efficiencies in nursing homes. Educational paradigms studied have strengths and weakness in furnishing various job skills. These results are helpful in defining strategic actions for addressing both current deficiencies and future training needs. A specialized long-term care model that incorporates appropriate clinical and business skills is recommended. The roles of continuing education and executive educational offerings also need streamlining. These initiatives would require a joint effort from policymakers, academicians, and practitioners.

Educational Status↗

PubMed1997

Educational preparation and attributes of community and migrant health center administrators.

Based on a 1994 national survey of Community and Migrant Health Center (C/MHC) administrators, this study draws a profile of C/MHC administrators in terms of their personal and work characteristics, as well as their values and beliefs regarding successful C/MHC attributes and important managerial practices. Further, the study compares C/MHC administrators with different educational preparation in terms of their personal and work characteristics, values and beliefs, as well as their perceived deficiencies. The study results indicate that critical factors in C/MHC success, in order of ranked importance, were good organizational leadership, organization's value to community and efficiency. Successful managerial characteristics, in order of ranked importance, were vision for the future of organization, honesty/integrity and open to new possibilities. Administrators with more advanced degrees expressed less deficiencies and those with no college degree showed greatest deficiency on five of eight measures.

Chi-Square Distribution↗

PubMed1997

[Relationship between dietary nutrients intakes and human prostate cancer].

In order to study the relationship between dietary nutrients intakes and prostate cancer, 1 : 1 matched case-control study was carried out with 102 patients suffered from histologically confirmed prostate cancer and 102 healthy controls. Total calories and 11 nutrients including protein, lipid and carbohydrates were calculated based on the mean food intakes in the latest 3 days. Analyzed by matched t-test and conditional logistic regression method, the results showed that high intakes of lipid, carbohydrates, and retinol increased the risk of prostate cancer, but vitamin C and vitamin B1 decreased the risk of prostate cancer. The multivariable adjusted ORs were 1.65 (95% confident interval (CI) 1.39-1.96) for lipid, 1.22 (95% CI 1.13-1.31) for carbohydrates, 3.21 (95% CI 2.18-4.75) for retinol, 0.61 (95% CI 0.6-0.80) for vitamin C, and 0.029 (95% CI 0.009-0.09) for vitamin B1. The authors discussed the possible mechanism of dietary nutrients contributing to the risk of prostate cancer.

Adult↗

PubMed1997

[Epidemiological study on human prostate cancer in Wuhan City].

In America, Canada and many European countries, prostate cancer is the most common cancer and the second leading cause of cancer death in men. In China, the morbidity rate and mortality rate of prostate cancer are unknown. Based on the reports of Wuhan cancer surveillance in 1990-1992, this study researched the epidemiological characterics of prostate cancer. The results showed that morbidity rate and mortality rate in Wuhan city are 1.37 and 0.75 per 100,000 respectively, and the standardized morbidity rate and standardized mortality rate are 1.10 and 0.66 per 100,000 respectively. They also showed that history of urinary diseases (OR = 5.42, 95% confidence interval (CI): 1.56-18.83), children number with more than 3 (OR = 2.43, 95% CI: 1.17-5.02), coitus with more than 3 times per week in youth (OR = 3.38, 95% CI: 1.51-7.58), frequent use of sexual drugs (OR = 4.12, 95% CI: 1.65-10.25) and high body mass index (OR = 2.58; 95% CI: 1.30-5.11) are identified as risk factors of prostate cancer statistically, but physical labor (OR = 0.35, 95% CI: 0.17-0.71) and age of first nocturnal emission after 18 years old (OR = 0.20, 95% CI: 0.08-0.52) are protective factors.

Adult↗

PubMed1997

A study on plasma norepinephrine and epinephrine levels in TCM liver syndromes.

The levels of plasma norepinephrine (NE) and epinephrine (E) were determined by HPLC in 220 patients with various TCM liver syndromes, and in 96 healthy subjects as controls. The plasma NE and E contents were higher in patients with liver excess syndromes, including Ganqi Yujie (GQYJ [symbol: see text]) syndrome, Ganyang Shangkang (GYSK [symbol: see text]) syndrome, Ganhuo Shangyan (GHSY [symbol: see text]) syndrome, and Ganyang Huafeng (GYHF [symbol: see text]) syndrome; while they were lower in patients with liver deficiency syndromes, including Ganqixu (GQX [symbol: see text]) syndrome, Ganxuexu (GXX [symbol: see text]) syndrome, and Ganyinxu (GYX [symbol: see text]) syndrome. Futhermore, when Ganshen Yinxu (GSYX [symbol: see text]) syndrome was turned into GYSK and then into GYHF, the plasma NE and E contents increased in order of precedence; while when GQYJ was turned into Ganyu Pixu (GYPX [symbol: see text]) syndrome, both NE and E contents decreased. The results suggest that the plasma NE and E contents are reliable objective parameters for the study of pathophysiological basis of the liver excess and liver deficiency syndromes, and the liver-kidney and liver-spleen interrelated syndromes.

Adolescent↗

PubMed1997

[Radioimmunologic targeting and therapy with antihuman primary hepatic cancer monoclonal antibodies (Hepama I) in patients].

OBJECTIVE: Effects of monoclonal antibody Hepama-I on targeting and therapy for primary hepatic cancer (PHC) were studied. METHODS: Thirty patients with veritified unresectable PHC were included in this study. For radioimmunoimaging (RII), 131I hepama was administered to 18 patients at a mean dose of 9.25 GBq. For radioimmunotherapy (RIT), 12 patients received a mean dose of 18.5 GBq by Seldinger's method via the hepatic artery. RESULTS: The optimum imaging time was 96 hours after injection. A decline in AFP level was found in 6/8 (75.0%). Reduction of tumor volume was observed as PR 66.6% and the survival time was prolonged in groups with 131I-Hepama-I treatment. CONCLUSION: Hepama I can recognized PHC cells in vivo and intra-hepatic arterial infusion of 131I-Hepama I is one of the acceptable methods of multimodality treatment for unresectable primary hepatic cancer in man.

Adult↗

PubMed1997

[Detection of P-glycoprotein in squamous cell carcinoma of larynx].

The multidrug resistance (MDR) of malignant tumor is a troublesome problem in the chemotherapy. One established mechanism of multidrug resistance is elevated expression of the P-glycoprotein (PGP). JSB1 (which is a special monoclonal antibody of human MDR, PGP) was used to examine the expression of PGP by immunohistochemistry in 23 specimens of squamous cell carcinoma of larynx. The expression of JSB1 in 10 normal laryngeal tissue specimens was also studied, no positive result was found. Of the 23 laryngeal cancer specimens, positive reaction to JSB1 was showed in 15, and there was no relationship between the positive expression, and the tumor differentiation, T staging and lymph-node metastasis. However, by using another newly developed monoclonal antibody C219, a different result was obtained from specimens of the same patients.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1997

[Histological study of experimental reconstructive materials for lateral skull base and dural defect in dogs].

In order to observe the reconstructive effects of fascia lata, superficial fascia and bone morphogenic protein (BMP) in skull base surgery, a lateral skull base bone and dural defect model in dogs was established. Fascia was selected alone or combined with BMP as repairing materials and BMP was evaluated in reconstructing large cranial defect model. Forty dogs underwent a 3.0 x 4.0 cm full-thickness excision of the parietal bone were divided into different groups of five dogs each, and were reconstructed by 1. fascia lata; 2. fascia lata plus BMP; 3. nonreconstructed controls; 4. fascia lata plus BMP and exposed. The implants were harvested at 2-15 weeks and examined histologically. The new bone was found in the BMP. Implants treated and untreated were quite different. The unreconstructed controls demonstrated only a bridge of fibrovascular connective tissue. BMP are defined as osteoinductive by their ability to produce bone formation by stimulating mesenchymal cells to transform into bone-producing osteo-blasts. The results suggested the combination of BMP and reconstructive material in the treatment of bone defects.

Animals↗

PubMed1997

[Experimental study of anti-tumour effect of rhTNF alpha on the laryngeal squamous cell carcinoma].

The anti-tumor effect of rhTNF alpha (recombination human tumor necrosis factor) with three different doses on laryngeal squamous cancer was investigated in nude mice. The results indicated that the higher and the middle doses of rhTNF alpha had significant antitumour effect against laryngeal cancer in BALB/C nude mice. The inhibitory rate of tumor growth was 54.4%(P < 0.05). The lower dose of rhTNF alpha also had antitumour effect but the cancer grew again when rhTNF alpha was stopped. Ultrastructural changes showed that the plasma membrane and the nucleus envelope of the tumor cell were destroyed and the number of lysosomes increased, fibroid material could be seen in the cancer capillary.

Animals↗