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Biomedical subjects

M Sun

Publications and source records attributed to M Sun.

At least 163 records · Page 9Linked to original sources
PubMed1997

[Ten-case report on primary cervical lymphoma].

OBJECTIVE AND METHODS: Clinical feature, treatment and prognosis of primary cervical lymphoma: are retrospectively analysied. RESULTS: The disease is rare, comprising about 0.9% of all primary cervical malignancies. The average age was 43.6 years. Seven cases had history of familial carcinoma. The complaints: abnormal vaginal bleeding and/or vaginal discharge. The usual pattern of growth was endophytic or polypoid. By FIGO cervical cancer, staging system, there were 8/10 stage I b, 1/10 stage II b and 1/10 stage IV. Histologically all were NHL, B cell lesions(7/10) were the diffuse, cleaved or cleaved-noncleaved cell type. Combination of surgery and chemotherapy were used for 9 of these 10 patients. The follow-up period was 3-66 months. Only one patient had relapse 41 months after the treatment while, others (9/10) survived with no evidence of the disease. CONCLUSION: The prognosis is favorable if cervical lymphoma is discovered early and treated properly.

Adult↗
PubMed1997

The effect of moderately increased CO2 concentration on perception of coherent motion.

BACKGROUND: Several studies have shown that some aspects of vision are impaired when exposed to higher than normal CO2 concentrations in air. The effect of moderately increased CO2 concentration on coherent motion perception, however, has not been studied. HYPOTHESIS: Studies in neurophysiology and cell biology have provided evidence that higher than normal CO2 concentration in air affects cell activities from the retina to the cortex, including the V1 area in the visual cortex. We predicted that motion perception may be impaired by moderately increased CO2, since the V1 area is a gateway for visual motion information processing. The purpose of the present work was to investigate the effect of 2.5% CO2 concentration in air on coherent motion perception. METHODS: Random dot cinematograms were generated by a computer and served as visual stimuli. A whole-room indirect calorimeter was used for the accurate measurement and control of CO2 concentration in air, and served as the experimental environment. A two-interval-forced choice (2IFC) psychophysical procedure was employed to obtain psychometric functions. RESULTS: For all three subjects, psychometric functions were shifted to the right when exposed to 2.5% CO2 in breathing air, compared to those using fresh air. CONCLUSION: This finding implies that human ability in detecting coherent motion can be temporally impaired when CO2 concentration in air is raised to 2.5%.

Aerospace Medicine↗
PubMed1997

[Effects of smoking on oxygen free radicals and fibrinolytic system].

UNLABELLED: The effects of smoking on SOD, MDA, t-PA, PAI-1 were studied in 20 healthy men (10 smokers and 10 nonsmokers). RESULTS: SOD decreased and MDA increased significantly in smokers. After acute smoking, SOD decreased and MDA increased significantly in all the subjects, t-PA and PAI-1 activities were increased immediately after acute smoking. There was a significant positive relationship between increased t-PA and SOD, whereas a significant negative relationship exists between increased t-PA and MDA. CONCLUSION: Smoking increases oxygen free radicals. The release of t-PA is decreased in smokers, that might be resulted from the increases of oxygen free radicals.

Adult↗
PubMed1997

[A study on the relationship between plasma level of ET-1 and cGRP and blood pressure in hemodialysis patients].

Plasma endothelin-1 (ET-1) and calcitonin gene related peptides (cGRP) were studied by immunoradiological method in 60 hemodialysis (HD) patients. The results showed that: (1) Plasma level of ET-1 and cGRP were increased in the HD patients. (2) Plasma level of ET-1 and cGRP varied in different times of HD. (3) A significantly positive relation between plasma ET-1 and blood pressure (BP) existed in the HD patients, while a significantly negative relation between plasma cGRP and BP existed in the HD patients. The results suggest that ET-1 and cGRP are major factors which lead to BP changes in HD patients.

Adult↗
PubMed1996

STAT3 participates in transcriptional activation of the C-reactive protein gene by interleukin-6.

Interleukin-6 (IL-6) is the major cytokine inducing transcription of human C-reactive protein (CRP) during the acute phase response. STAT (signal transducers and activators of transcription) family members, recently shown to be important mediators of the effects of many cytokines including IL-6, generally induce their effects by binding to palindromic sequences with TT(N)5AA motifs. We report an IL-6 responsive element in the proximal region of the human CRP 5'-flanking region that bears a TT(N)4AA motif, which we have termed CRP acute phase response element (CRP-APRE). In Hep3B cells, IL-6 but not interferon-gamma was capable of activating CAT constructs driven by the CRP promoter containing CRP-APRE. Overexpressed STAT3 was able to transactivate CRP-chloramphenicol acetyltransferase constructs through the CRP-APRE and was able to enhance endogenous CRP mRNA accumulation in response to IL-6. STAT3 (or an antigenically related molecule) bound to the CRP-APRE in response to IL-6. Overexpression of STAT3 in the presence of IL-6 was capable of inducing expression of a construct consisting of the CRP-APRE and a minimal thymidine kinase promoter lacking a C/EBP site. Taken together, these findings indicate that STAT3 participates in the transcriptional activation of CRP in response to IL-6.

Acute-Phase Proteins↗
PubMed1996

CD30 (Ki-1)-positive malignant lymphomas: clinical, immunophenotypic, histologic, and genetic characteristics and differences with Hodgkin's disease.

This study compares the histologic and immunophenotypic features of 71 cases of primary CD30+ diffuse large-cell lymphomas (DLCL) and 128 cases of Hodgkin's disease (HD) and discusses the clinical features of 52 patients with CD30+ DLCL. It includes analysis of sites of involvement, staging, response to treatment, sites and treatment of recurrences, and disease-free and overall survival. Diagnostic immunophenotypic differences were found between CD30+ DLCL and HD. All cases of CD30+ DLCL were positive for one or more common or lineage-specific lymphocyte antigens or for EMA. In contrast, 96.9% of HD cases were negative for CD45, CD45-RO, CD43, and CD20. The four exceptions are discussed. All cases of HD were negative for EMA. In patients with CD30+ DLCL, a T-cell phenotype was found in 60%, a null-cell type in 22%, and a B-cell type in 18% of the cases. The median age of patients with T- and null-cell phenotype was 22 years (range, 4 to 72). Fifty-two percent of them had high-stage (III and IV) disease and 61% had extranodal involvement at presentation, including 25% with skin lesions. Lymph nodes draining the skin lesions became involved in seven of 11 patients. No patient had initial bone marrow involvement. Most patients were treated with chemotherapy, and 83% had a complete remission. Fifty-four percent remain free of disease with a median follow-up of 47 months. Thirteen patients (29%) had one or more recurrences and five of them remain free of disease after salvage therapy, with a median follow-up period of 79 months. The clinical stage did not affect survival, probably as a result of different therapy. The t(2;5) translocation was found in five of 15 patients who had cytogenetic abnormalities. Of the other 10 cases, the translocation was detected by reverse transcriptase-polymerase chain reaction (RT-PCR) in four of five cases studied. All nine cases were of T- or null-cell phenotype. The cases of B-cell CD30+ DLCL had a characteristic immunophenotype. All were negative for EMA. These patients were older and had frequent bone marrow involvement but no skin infiltration by lymphoma. All three patients who were human immunodeficiency virus-positive (HIV+) had lymphomas of B-cell lineage. Detection of the t(2;5) translocation by molecular genetics is a useful and highly specific marker in the differential diagnosis between HD and CD30+ DLCL.

Adolescent↗
PubMed1996

Glucocorticoids stimulate prostaglandin H synthase type-2 (PGHS-2) in the fibroblast cells in human amnion cultures.

The human amnion may be an important source of prostaglandins involved in the onset of labour. Glucocorticoids are possible regulators of amnion prostaglandin synthesis and have been shown to stimulate the PGE2 output and prostaglandin H2 synthase (PGHS) activity of human amnion cells maintained in primary monolayer culture. There are two known isoforms of PGHS: the constitutively expressed PGHS-1 and the inducible PGHS-2. Recent studies have shown that the latter isoform is induced by glucocorticoids. The amnion consists of a single layer of epithelial cells beneath which lies a mesenchymal layer containing fibroblasts and it is not known which cell types are responding to glucocorticoids in this manner. In the present study, we demonstrate that although both cell types are present in culture, PGHS-2 protein and mRNA levels increase exclusively within the fibroblasts in response to dexamethasone, while PGHS-1 protein and mRNA levels remain unaffected in both cell types. These results suggest that the stimulation of PGE2 in cultured amnion cells by glucocorticoids is due to an upregulation of PGHS-2 gene transcription in fibroblasts, and that these previously overlooked cells may have important roles to play in the synthesis of prostaglandins involved in labour.

Amnion↗
PubMed1996

Evaluation of Bacillus thuringiensis and Bacillus sphaericus Strains from Chinese Soils Toxic to Mosquito Larvae

During our research to isolate and screen microbial agents, eight Bacillus thuringiensis isolates and five Bacillus sphaericus isolates were shown to have high toxicity to mosquito larvae. Comparing the LC50 values, four B. sphaericus isolates with LC50 values ranging from 0.50 to 1.47 ng/ml were about two to six times more toxic than strain 1593 (LC50 3.00 ng/ml) against larvae of Culex quinquefasciatus. Four B. thuringiensis isolates (LC50 values ranging from 3.80 to 7.54 ng/ml) and four B. sphaericus isolates with LC50 of 17.0 to 43.7 ng/ml were more toxic to Aedes aegypti than strain 1897 (LC50 8.46 ng/ml) and strain 1593 (LC50 67.3 ng/ml). As to Anopheles hyrcanus, the LC50 values of three B. sphaericus isolates ranging from 3.63 to 5.73 ng/ml were three to five times smaller than that of strain 1593 (LC50 16.1 ng/ml). Two B. sphaericus isolates showed high toxicity against mosquito larvae in the three genera Culex, Aedes, and Anopheles.

Journal Article↗
PubMed1996

Computer classification of sleep in preterm and full-term neonates at similar postconceptional term ages.

A classification strategy of neonatal sleep is being developed by comparing visually scored minutes of 21 channels of electroencephalographic (EEG)/polygraphic recordings with the corresponding values for each physiological signal derived from either visual or computer analyses. Continuous 3-hour sleep studies on 54 preterm and full-term neonates at similar postconceptional term ages were acquired under environmentally controlled conditions using a computerized monitoring system. An on-line event marker program recorded behavioral observations. One of three EEG sleep states was assigned to each of 8,995 minutes by traditional visual analysis criteria. EEG spectral values, spectral and nonspectral cardiorespiratory calculations and behaviorally observed movements, arousals and rapid eye movement counts were submitted for discriminant analysis. Based on the total minutes known for each of three states (i.e. active, quiet and awake), linear combinations of all specified digitized parameters were formed into an arithmetic algorithm by use of discriminant analysis, which served as the basis of a state assignment for each minute. Fifty percent of the data were arbitrarily used as the training set to derive the state classification model. The remaining fifty percent of the data were used as the cross-validation "test sample" to determine the accuracy of the classification when compared to the visually analyzed score for each corresponding minute. Thirteen out of 32 physiological measures best predicted state of both preterm and full-term neonatal groups. For both groups, the correct classification for active sleep was 90.3%, quiet sleep was 97.4%, awake was 97% and the overall accuracy was 93.3%. However, the order of significance for specific variables differed between these two neonatal groups. Differences in the order of variables that predict sleep states between preterm and full-term infants may reflect adaptation of brain function of the preterm infant to prematurity and/or prolonged extrauterine experience.

Child, Preschool↗
PubMed1996

Irinotecan is an active agent in untreated patients with metastatic colorectal cancer.

PURPOSE: To determine the response rate, survival, and toxicity of the new anticancer agent, irinotecan (CPT-11), in the treatment of metastatic colorectal cancer. PATIENTS AND METHODS: Forty-one chemotherapy-naive patients with measurable metastatic colorectal cancer were treated with a 90-minute infusion of irinotecan 125 mg/m2 administered weekly for 4 weeks every 6 weeks. Pretreatment tumor biopsies to assess topoisomerase-I (Topo-I) activity were obtained from 11 patients. The pharmacokinetics for irinotecan and its active metabolite, SN-38, were determined in 18 patients. RESULTS: Thirteen of 41 patients (32%) had a partial response (PR; 95% confidence interval, 18% to 46%). The median response duration was 8.1 months (range, 4.0 to 16.0) and the median survival time was 12.1 months (range, 2.1 to 21.7) for all 41 patients. Grade 3 or 4 toxicities were diarrhea (29% of patients) and neutropenia (22% of patients). Grade 3 or 4 diarrhea was substantially more prevalent in the initial 18 patients on study, with an incidence rate of 56%; a significant reduction in the incidence of severe diarrhea to 9% was noted with strict adherence to an antidiarrheal regimen of loperamide and diphenyldramine. No correlations were seen between pharmacokinetics of irinotecan/SN-38 and the clinical parameters of response, survival, or incidence of diarrhea. CONCLUSIONS: Irinotecan has activity in the treatment of patients with metastatic colorectal cancer. Strict adherence to an antidiarrheal regimen of diphenhydramine/loperamide significantly reduced the incidence of diarrhea; the agent was thereafter well tolerated in the majority of patients.

Adult↗
PubMed1996

Nutrition in minority elders: current problems and future directions.

Nutrition and aging are inseparably connected as eating patterns affect the progress of many degenerative diseases associated with aging. In turn, the nutritional status of the elderly, particularly minority elders (the most rapidly growing segment of the population in the United States), may be adversely affected by a number of factors associated either directly or indirectly with aging. Because reducing morbidity through health promotion and disease prevention could both improve the quality of elderly life and lessen the burden on the health care system, it would seem reasonable that such efforts, including nutrition education, in minority elderly would be of benefit. The extent of the potential value of such preventive programs, however, remains uncertain, and the task of determining nutrient needs of the elderly difficult. Special studies are required to describe the association of nutrition-related factors with chronic diseases, particularly those prevalent in minority elders.

Age Factors↗
PubMed1996

Immunohistochemical localization of the glucocorticoid receptor in human fetal membranes and decidua at term and preterm delivery.

The human fetal membranes and decidua may be important in the onset and/or progression of human labor by providing prostaglandins for this process. Glucocorticoids have been implicated in the regulation of prostaglandin production by these tissues but to date there is no direct evidence for glucocorticoid receptors (GRs) being present in human intrauterine tissues. The purpose of the present study was to determine, using immunohistochemistry, whether the human fetal membranes and decidua contained GRs; to determine the localization of receptors to the cytoplasm or nuclei, and to examine the content and distribution of the GRs in tissues obtained during pregnancy following preterm labor (< 37 weeks) and at term prior to and following term labor. Term tissues were obtained prior to labor by elective Caesarean section (n = 9) or following vaginal delivery (n = 9). Tissues from 14 patients who delivered preterm but with no clinical evidence of infection were also examined. Cryostat sections were thaw-mounted onto microscope slides. The immunoreactive GRs were visualized with an Elite Vectastain ABC Kit using a polyclonal antibody prepared against a synthetic peptide corresponding to amino acids 346-367 of the human GR. At term, nuclear GRs were found in amnion epithelial cells, mesenchyme and the chorion laeve. GRs were present, but were less defined, in the decidua. A similar distribution was found in the preterm tissues. However, nuclear staining in the amnion epithelial cells, mesenchymal cells, chorion and decidua was more pronounced in tissues obtained following preterm labor. This study provides direct evidence for the presence of GRs in human fetal membranes and decidua, and suggests the possible importance of multiple cell types in the action of glucocorticoids in these tissues.

Amnion↗
PubMed1996

Localization of prostaglandin H synthase type 2 protein and mRNA in term human fetal membranes and decidua.

Prostaglandin (PG) production by human fetal membranes (amnion and chorion laeve) may be important in the onset and progression of labour, cervical ripening and membrane rupture. Prostaglandin H synthase (PGHS) is a key enzyme in PG formation and has two isoforms, a constitutive form (PGHS-1) and an inducible form (PGHS-2). The present study examined the cellular distribution of the PGHS-2 enzyme and PGHS-2 mRNA in term human fetal membranes and decidua prior to and following labour, using immunohistochemistry and in situ hybridization with an 35S-labelled oligonucleotide probe. The PGHS-2 protein was found to be localized in amnion epithelial cells and chorion laeve trophoblast, but was absent or at low levels in the decidual stroma in most tissues, although cells surrounding some of the blood vessels in the decidual did express PGHS-2. In situ hybridization demonstrated that PGHS-2 mRNA had a similar distribution and was localized to amnion epithelial cells, cells in the amnion-chorion mesenchyme, chorion laeve trophoblast and, occasionally, to cells surrounding blood vessels in the decidua. Of particular note was the high mRNA expression in some cells and low expression in other cells, particularly in the chorion, and the low level of PGHS-2 mRNA in decidua. There was no observable difference in the cellular localization of PGHS-2 protein or PGHS-2 mRNA in tissues obtained prior to and following labour. The studies indicate that, at term, the inducible form of PGHS, PGHS-2, is expressed at a high level in fetal tissues in a number of different cell types rather than in the maternal decidua.

Base Sequence↗
PubMed1996

Increased energy expenditure in hemodialysis patients.

Malnutrition is prevalent in chronic hemodialysis patients and is related to multiple factors; the hemodialysis procedure itself has been suggested as a catabolic factor. To examine the possible role of hemodialysis on energy metabolism, resting energy expenditure and respiratory quotient in ten chronic hemodialysis patients was measured in this study, using a whole-room indirect calorimeter. Measurements were done continuously: for 2 h before hemodialysis, during 4 h of hemodialysis, for 2 h after hemodialysis, and separately on a nondialysis day after 12 h of fasting. Age-, sex-, and body mass index-matched healthy volunteers were used as control subjects. Chronic hemodialysis patients have a significantly higher resting energy expenditure on a nondialysis day (1.18 +/- 0.15 kcal/min; P < 0.01) as compared with control subjects (1.10 +/- 0.16 kcal/ min). Resting energy expenditure further increased significantly during the hemodialysis procedure (1.32 +/- 0.18 kcal/min, averaged over the 4 h of hemodialysis; P < 0.01 versus predialysis) and was also significantly higher compared with the postdialysis period and nondialysis day resting energy expenditure (P < 0.001 for both). This effect was most pronounced during the first (1.37 +/- 0.19 kcal/min) and second (1.33 +/- 0.18 kcal/min) hours of hemodialysis (P < 0.001 for both). Respiratory quotient was not significantly affected by hemodialysis. It was concluded that chronic hemodialysis patients have higher than normal resting energy expenditure levels, which is further increased during hemodialysis. This process may significantly potentiate the protein-calorie malnutrition seen in this patient population.

Adult↗
PubMed1996

Energy expenditure, television viewing and obesity.

OBJECTIVE: To measure energy expenditure (EE) of television viewing, sitting, and resting and duration of self-selected television viewing in obese and non-obese men and women. DESIGN: Cross-over randomized study consisting of two separate 24-h stays in a whole-room indirect calorimeter. SUBJECTS: 123 obese and non-obese healthy men and women (age: 38 +/- 9, BMI: 29.4 +/- 7.9) MEASUREMENTS: Rates of energy expenditure during resting (RMR), sitting (EEsit) and television viewing (EEtv) using indirect calorimetry technique on two separate 24-h stays in a whole-room indirect calorimeter. Physical activities and work of body movements during these periods using a large force platform system located inside the calorimeter. RESULTS: Rates of EE for television viewing, adjusted for differences in body composition were 18% higher than resting metabolic rate (RMR), but similar to rates of other sedentary activities. There were no significant differences between obese and non-obese subjects in metabolic rates during resting, television viewing, and other sedentary activities. Average time of self-selected television viewing was significantly greater in obese than in non-obese subjects and also in women than in men. CONCLUSION: EE rate for television viewing in adults is higher than RMR and similar to other sedentary activities. Obese adults choose television viewing as a form of leisure activity more often than non-obese individuals and as a result they could significantly reduce other forms of physical activities and total daily EE.

Adult↗