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Biomedical subjects

G Shen

Publications and source records attributed to G Shen.

At least 91 records · Page 5Linked to original sources
PubMed1997

Risk factors for hospitalization in a cohort with type 1 diabetes. Wisconsin Diabetes Registry.

The authors investigate the postonset hospitalization rate and risk factors during 1987-1994 in Wisconsin, in a population-based, incidence cohort followed from diagnosis of Type 1 diabetes mellitus at ages 0-29 (n = 577). The overall rate was 8.9 +/- 0.60 (standard error) per 100 person-years of diabetes, whereof 5.7 was due to hyperglycemia, 1.9 to hypoglycemia, and 1.3 to other and undetermined causes. Major risk factors for hospitalization were longitudinally measured glycosylated hemoglobin level (rate ratio = 1.5 per 2% increase, 95% confidence interval 1.4-1.7), black/other race (rate ratio = 1.9, 95% confidence interval 1.0-3.6), diagnosis in a non-university-based setting (rate ratio = 1.9, 95% confidence interval 1.2-3.2), female sex (rate ratio = 1.5, 95% confidence interval 1.0-2.4 at age 11), age in males (rate ratio = 0.6, 95% confidence interval 0.4-0.8 per 5-year increase), and public or no insurance up to 18 months postdiagnosis (rate ratio = 2.2, 95% confidence interval 1.1-4.4). For individuals less than 18 years, "black/other race" was replaced in the model by "having other than two biologic parents in the home" (rate ratio = 2.0, 95% confidence interval 1.1-3.5). Hence, hospitalization is common in children, adolescents, and young adults with diabetes, primarily for problems with glycemic control.

Adolescent↗
PubMed1997

Nutritional benefits of neonatal screening for cystic fibrosis. Wisconsin Cystic Fibrosis Neonatal Screening Study Group.

BACKGROUND: Many patients with cystic fibrosis are malnourished at the time of diagnosis. Whether newborn screening and early treatment may prevent the development of a nutritional deficiency is not known. METHODS: We compared the nutritional status of patients with cystic fibrosis identified by neonatal screening or by standard diagnostic methods. A total of 650,341 newborn infants were screened by measuring immunoreactive trypsinogen on dried blood spots (from April 1985 through June 1991) or by combining the trypsinogen test with DNA analysis (from July 1991 through June 1994). Of 325,171 infants assigned to an early-diagnosis group, cystic fibrosis was diagnosed in 74 infants, including 5 with negative screening tests. Excluding infants with meconium ileus, we evaluated nutritional status for up to 10 years by anthropometric and biochemical methods in 56 of the infants who received an early diagnosis and in 40 of the infants in whom the diagnosis was made by standard methods (the control group). Pancreatic insufficiency was managed with nutritional interventions that included high-calorie diets, pancreatic-enzyme therapy, and fat-soluble vitamin supplements. RESULTS: The diagnosis of cystic fibrosis was confirmed by a positive sweat test at a younger age in the early-diagnosis group than in the control group (mean age, 12 vs. 72 weeks). At the time of diagnosis, the early-diagnosis group had significantly higher height and weight percentiles and a higher head-circumference percentile (52nd, vs. 32nd in the control group; P=0.003). The early-diagnosis group also had significantly higher anthropometric indexes during the follow-up period, especially the children with pancreatic insufficiency and those who were homozygous for the deltaF508 mutation. CONCLUSIONS: Neonatal screening provides the opportunity to prevent malnutrition in infants with cystic fibrosis.

Body Height↗
PubMed1997

Incidence of retinopathy and associated risk factors from time of diagnosis of insulin-dependent diabetes.

OBJECTIVE: To describe the prevalence at baseline and 4-year incidence of retinopathy and its relation to glycemic control from the time of diagnosis of insulin-dependent diabetes. DESIGN: Geographically defined population-based study. SETTING: Twenty-eight-county area in Wisconsin. STUDY POPULATION: Incipient cohort of children, teenagers, and young adults (n = 354) up to 30 years of age with newly diagnosed insulin-dependent diabetes. MAIN OUTCOME MEASURE: Diabetic retinopathy as determined by gradings from 30 degrees color stereoscopic photographs of the Diabetic Retinopathy Study 7 standard fields. RESULTS: The prevalence of retinopathy at diagnosis was 1.3%. Four years after diagnosis of diabetes, retinopathy was first identified in 5.1% of our cohort and in 9.7% of those 15 years of age or older. After controlling for age, subjects with a mean glycosylated hemoglobin level of 12% or greater were 3.2 times as likely (95% confidence interval, 1.1-9.9) to have retinopathy present at follow-up as were subjects with a mean glycosylated hemoglobin level of less than 12%. CONCLUSION: Population-based data on the frequency and incidence of retinopathy from the time of diagnosis of insulin-dependent diabetes mellitus provided by this study suggest a possible reduction in risk of developing retinopathy in those in whom glycemic control is achieved from the time of diagnosis.

Adolescent↗
PubMed1997

Rhinovirus infection preferentially increases lower airway responsiveness in allergic subjects.

Rhinovirus (RV) infections are important triggers of acute asthma symptoms in susceptible persons. To determine whether the presence of allergy is a risk factor for enhanced lower airway effects during RV infection, we experimentally infected (RV16) 18 volunteers with allergic rhinitis and 13 normal control subjects and measured the effects on the response of the lower airways to histamine. All subjects were successfully infected, as indicated by increased upper respiratory symptoms and RV16 cultured from nasal secretions. The change in histamine PD20(deltaPD20) caused by RV infection was significantly different in allergic subjects from that in nonallergic control subjects (deltaPD20 = -0.40 versus -0.03 log units, p = 0.04). This relationship was strengthened after adjusting for initial PD20 and FEV1 (mean deltaPD20 = -0.43 versus 0.01 log units, p < 0.01). The virus-induced deltaPD20 was also influenced by baseline lung function: there was a positive correlation between initial FEV1 and deltaPD20, and a weak but significant negative correlation between baseline PD20 and deltaPD20. These findings indicate that host factors such as allergy, baseline FEV1, and baseline PD20 influence the changes in lower airway physiology caused by RV infection and raise the possibility that these factors contribute to the increased lower airway effects of RV infection in subjects with asthma.

Adult↗
PubMed1997

Acquisition of Pseudomonas aeruginosa in children with cystic fibrosis.

OBJECTIVE: This study was pursued as an extension of a randomized clinical investigation of neonatal screening for cystic fibrosis (CF). The project included assessment of respiratory secretion cultures for pathogens associated with CF. The objective was to determine whether patients diagnosed through neonatal screening and treated in early infancy were more likely to become colonized with Pseudomonas aeruginosa compared with those identified by standard diagnostic methods. METHODOLOGY: The design involved prospective cultures of respiratory secretions obtained generally by oropharyngeal swabs at least every 6 months and more often if clinically indicated. Patients were managed with a standardized evaluation and treatment protocol at the two Wisconsin certified CF centers; however, there were community and environmental variations associated with the follow-up period as described below. RESULTS: Overall, there were no differences in acquisition of respiratory pathogens between the screened and the control (standard diagnosis) groups. Evaluation of the data between and within the two centers, however, revealed significant differences with earlier acquisition of P aeruginosa in the center with the following distinguishing characteristics: urban location; following patients with the standard US approach in which newly diagnosed, young children were interspersed with older CF patients; and where there were more opportunities for social interactions with other CF patients. The differences were confined to the screened group followed in the urban center in which the median pseudomonas-free survival period was 52 weeks contrasted with 289 weeks in the other center. In addition, assessment of data for the entire CF populations followed at the two centers revealed that the urban center showed a significantly higher prevalence of P aeruginosa colonization in patients between the ages of 3 and 9 years. CONCLUSIONS: These results present questions and generate hypotheses on risk factors for acquisition of P aeruginosa in CF and suggest that clinic exposures and/or social interactions may predispose such patients to pseudomonas infections.

Cystic Fibrosis↗
PubMed1997

Long-term hyperglycemia is related to peripheral nerve changes at a diabetes duration of 4 years. The Wisconsin Diabetes Registry.

OBJECTIVE: To examine longitudinal hyperglycemia and peripheral nerve responses in a population-based incident cohort. RESEARCH DESIGN AND METHODS: A sample from an incident cohort of young people was comprehensively followed from diagnosis of IDDM. Participants were invited to submit blood samples three times per year for central testing of GHb. During their 4th year of diabetes, nerve conduction studies were performed on the median sensory and motor, peroneal motor, and sural sensory nerves. Relationships between mean GHb and nerve latencies, velocities, and amplitudes were explored. RESULTS: GHb was positively related to all nerve latencies and negatively related to all nerve velocities. The relationships between mean GHb and nerve conduction latencies and velocities differed by sex for the peroneal nerve latency (beta = 0.17 male subjects, beta = -0.01 female subjects; P < 0.001). Pubertal participants had lower velocities and longer latencies than prepubertal participants (beta = 0.37; P = 0.05 peroneal latency), after adjustment for GHb, height, and extremity temperature. Sensory and motor nerve amplitudes were related to GHb, and these relationships did not differ by sex. CONCLUSIONS: Our study indicates that sustained hyperglycemia is related to functional changes, at the minimum, in peripheral sensory and motor nerve conduction at a diabetes duration of 4 years. Our findings are consistent with a dying-back neuropathy, and there is some suggestion that chronic hyperglycemia may be more detrimental to nerves in male subjects than in female subjects.

Adolescent↗
PubMed1997

[Investigation of potency to produce interleukin-2 of the peripheral blood T lymphocytes in patients with hemorrhagic stroke].

For further understanding the changes in immune function of the patients with hemorrhagic stroke, we investigated the activity of interleukin-2 (IL-2) in the peripheral blood T lymphocytes from 32 patients. The results showed that the levels of IL-2 in the patients were lower than those of the healthy controls, but no significant difference was observed between the cerebral hemorrhage group and subarachnoid hemorrhage group. It suggests the cellular immune function of patients at the acute period is low. We consider that IL-2 might be of use as a kind of therapeutic measure to modulate patients' immune function and treat the diseases.

Adolescent↗
PubMed1997

Special features of acute infection due to Schistosoma japonicum in urban and rural areas in China.

The statistical analysis of six indices: sex, age, occupation, time of onset, mode of infection and educational level of acute cases infected by Schistosoma japonicum in 1990 and 1994 respectively in Wuhu city was carried out. No significant differences were found in the five indices between 1990 and 1994 in Wuhu city except sex. There were significant differences between the urban and rural areas in all six indices.

Adult↗
PubMed1997

[Telescopic adhesive anastomosis of small blood vessel applied in formation of arteriovenous fistula for hemodialysis].

The formation of an arteriovenous fistual for dialysis by routine interrupted sutures anastomosing the vein and artery is difficult to perform and time-consuming. A new method, telescopic adhesive anastomosis was studied and applied in 10 hemodialysis patients, who were in need of an arteriovenous fistula. The external diameter of the vessels anastomosed was 2.40 +/- 0.20 mm (radial artery) or 2.40 +/- 0.35 mm (cephalic vein). After thorough debridement of the vascular ends, the arterial end was put in the venous lumen. In order to fix the telescopic vessels, two stitches were applied 180 degrees apart from each other and tied. Each stitch was inserted from vein (penetrating the whole wall) to artery (just through the adventitia and partial thickness of the media vasorum). The distance from the stitch to the edge of the vein was 0.5 mm, and that of the artery was approximated to the external diameter of the vessle. The medical adhesive was then applied for sealing the anastomotic adventitia. Ten seconds were given for the solidification of the adhesive. The patients were followed up for 8 months. The patency rate was 100%, and the rate of blood flow was more than 300 ml/min (measured by ultrasonography). It was shown that this method could be managed easily and quickly, and the so-formed fistula would fulfill the need of hemodialysis.

Adult↗
PubMed1996

Longitudinal patterns of glycemic control and diabetes care from diagnosis in a population-based cohort with type 1 diabetes. The Wisconsin Diabetes Registry.

Glycosylated hemoglobin is an indicator of long-term glycemic control and a strong predictor of diabetic complications. This paper provides a comprehensive description of glycemic control (total glycosylated hemoglobin (GHb)) up to 4.5 years duration of diabetes by age, duration, and sex in a population-based cohort (n = 507) aged less than 20 years followed from diagnosis of Type 1 diabetes in Wisconsin during 1987-1994 Important aspects of demographics and diabetes care are described to allow comparison with other populations. Since large variations between laboratories are known to exist in the measurement of GHb, levels are also interpreted relative to the frequency of short-term complications. GHb increased after diagnosis, but leveled off after 2-3 years. Peak GHb values occurred in the age group 12-15 years. The within-individual standard deviation in GHb between tests, adjusted for age and duration was 1.6%. The mean GHb at last testing was 11.3%, with a standard deviation across individuals of 2.9%. The majority (74%) of individuals saw a diabetes specialist at least once. The mean number of insulin injections per day increased from 2.2 to 2.5 across the 4.5-year duration, and the insulin dose increased from 0.6 to 0.9 units per day per kg body weight. Despite the quite satisfactory level of care, 38% of subjects had GHb levels associated with significant short-term complications.

Adolescent↗
PubMed1996

Immunoregulation of lupus-like NZB/W F1 mice by anti-murine IL-1 alpha, IL-6 antibodies.

Anti-murine IL-1 alpha, IL-6 antibodies were intra-peritoneally injected to the lupus-like NZB/W F1 mice of 4 months with the dosage of 10 micrograms per day for three days and then per month for three months. The mice were killed at the age of 11 months. The results showed that the treatment of the dosage could not absolutely prevent lupus nephritis--it could alleviate proteinuria, obviously reduce the levels of serum IL-1 alpha and inhibit the secretion of IL-1 alpha by celiac macrophage. As to the level of IL-6 and TNF-alpha no significant change was observed.

Animals↗
PubMed1996

Characterization of psaI and psaL mutants of Synechococcus sp. strain PCC 7002: a new model for state transitions in cyanobacteria.

The psaI and psaL genes were characterized from the cyanobacterium Synechococcus sp. strain PCC 7002. The gene organization was different from that reported for other cyanobacteria with psaI occurring upstream and being divergently transcribed from the psaL gene. Mutants lacking PsaI or PsaL were generated by interposon mutagenesis and characterized physiologically and biochemically. Mutant strains PR6307 (delta psaI), PR6308 (psaI-) and PR6309 (psaL-) had doubling times similar to that of the wild type under both high- and low-intensity white light, but all grew more slowly than the wild type in green light. Only monomeric photosystem I (PS I) complexes could be isolated from each mutant strain when Triton X-100 was used to solubilize thylakoid membranes; however, approximately 10% of the PS I complexes from the psaI mutants, but not the psaL mutant, could be isolated as trimers when n-dodecyl beta-D-maltoside was used. Compositional analyses of the mutant PS I complexes indicate that the presence of PsaL is required for trimer formation or stabilization and that PsaI plays a role in stabilizing the binding of both PsaL and PsaM to the PS I complex. Strain PR6309 (psaL-) was capable of performing a state 2 to state 1 transition approximately three times more rapidly than the wild type. Because the monomeric PS I complexes of this mutant should be capable of diffusing more rapidly than trimeric complexes, these data suggest that PS I complexes rather than phycobilisomes might move during state transitions. A "mobile-PS I" model for state transitions that incorporates these ideas is discussed.

Amino Acid Sequence↗
PubMed1996

Presence of free radicals in pigment gallstone in vivo.

OBJECTIVE: To clarify whether free radical, which may play a role in pigment gallstone formation, is present in pigment gallstones in vivo. MATERIALS AND METHODS: Free radical signal of gallstones from 18 patients was detected by electron paramagnetic resonance spectroscopy at 77K under anaerobic condition and in air (control). As soon as the anaerobic determination was finished, the fresh anaerobic sample was exposed to air and stored in a freezer at -20 degrees C. RESULTS: Free radical signal (g = 2.0038) was detected in fresh anaerobic samples containing more than 2% bilirubin compound, and the signal intensity correlated linearly with the content of calcium bilirubinate (r = +0.95, P < 0.0005). During the storage at -20 degrees C and exposure to air, the signal intensity of each anaerobic sample and its control increased gradually, eventually reaching the same stable level. Fe(III) signal intensity was enhanced synchronously and related linearly with free radical signal (r = +0.99, P < 0.0005). CONCLUSIONS: Free radical exists originally in pigment gallstones in vivo, and it may play an important role in pigment gallstone formation. The free radical signal carried by gallstones may be strengthened by the action of oxygen in air on bilirubin. The transition metal ions probably take part in the formation of bilirubin free radical.

Bilirubin↗
PubMed1996

[The prevalence and risk factors of carotid atherosclerosis in elderly patients].

To assess the prevalence of extracranial carotid artery atherosclerosis and its relation to principal cardiovascular risk factors in Chinese elderly patients, 100 cases aged from 54 to 94 were investigated with B-mode ultrasonography. Arterial intima-media thickening, plaque, mild stenosis (defined as a plaque that obstructed > 20% of the lumen diameter), and clinically significant stenosis (> 50% in cross-sectional area) were found in 79, 49, 40 and 3 patients, respectively. There was no significant correlation between carotid atherosclerosis and coronary heart disease, cerebral infarction, hypertension, hyperlipidemia or diabetes. In contrast, the prevalence of carotid atherosclerosis was increased with age (P < 0.05), so did the severity. Thus, age is a major risk factor for carotid atherosclerosis in the elderly.

Age Factors↗
PubMed1996

Enzyme-linked immunosorbent assay for detection of IgG against penicillins in children.

AIM: To establish an enzyme-linked immunosorbent assay (ELISA) for detection of IgG against penicillins and then investigate this antibody response in children. METHODS: Western blotting, ELISA, and hapten inhibition assay were used. RESULTS: Penicillins reacted with bovine serum albumin (BSA) to generate conjugate which was used as coating antigen (100 mg.L-1) in ELISA. A good correlation was found between absorbance (A) and dilutions of sample with a linear coefficient of 0.9918. Thirteen subjects who were clinically suspicious of penicillin allergy were tested for specific IgG by ELISA, 4 positive for benzylpenicillin, 1 for benzylpenicillin and piperacillin, and 3 for benzylpenicillin, piperacillin and ampicillin. CONCLUSION: An ELISA was successfully established and penicillin reactive IgG response in children was heterogeneous. IgG antibodies recognized benzylpenicillin molecule, degraded products and new antigenic determinant from conjugate. Cross reactions occurred among benzylpenicillin, ampicillin and piperacillin.

Child↗
PubMed1996

Benzylpenicillin induced specific non-IgE antibody response in mice.

AIM: To study whether or not the specific non-IgE antibody response in mice can be induced by benzylpenicillin in vivo. METHODS: Antibody response and antigenic cross reactions were determined by enzyme-linked immunosorbent assay (ELISA). Antigen molecules recognized by antibodies were tested by hapten inhibition assay. RESULTS: During d 1-d 50 after immunization, positive % of specific IgM, IgG, and IgA to benzylpenicillin were 100%, 50%-100%, and 17%-100%, respectively. IgM and IgG to benzylpenicillin also recognized ampicillin and piperacillin. The positive % of IgM and IgG to ampicillin were 23%-100% and 50%-100%, to piperacillin 43%-100% and 50%-100%, respectively. Aged benzylpenicillin showed an inhibitory effect on specific antibodies in a dose-dependent manner, and inhibitory % of specific IgM and IgG were 29%-87% and 29%-71%. However, freshly prepared benzylpenicillin had no effect. CONCLUSION: Specific non-IgE antibody response was successfully induced by benzylpenicillin in mice, in which the isotypes were mainly IgM and then IgG and IgA. Antibodies recognized degraded products, not benzylpenicillin molecule itself. Antigenic cross reactions occurred between benzylpenicillin, ampicillin, and piperacillin. Isotypes of antibodies responsible for cross reactions were mainly IgG and then IgM.

Animals↗
PubMed1995

Effects of expressing human Hsp70 and its deletion derivatives on heat killing and on RNA and protein synthesis.

We have established rat cell lines stably and constitutively expressing intact human heat shock protein (hsp) 70 and its deletion mutant derivatives. Using these stable cell lines, the functions of the various domains of human hsp70 were studied. An elevated level of human hsp70 or fragments containing the C-terminal portion of the protein, but not fragments containing the amino-terminal portion of the protein, is found to protect cells against thermal killing. Only the expression of intact human hsp70, however, can reduce the degree of heat-induced inhibition of translation and most effectively accelerate the recovery from heat-induced inhibition of transcription and translation. The peptide-binding domain in the carboxyl portion of hsp70 is of primary importance in protecting cells from thermal stress, probably through its binding to unfolded or partially folded polypeptides; this interaction, in turn, retards detrimental thermal denaturation or aggregation of key cellular proteins and protects cells from thermal stress. ATP binding and hydrolysis, on the other hand, are presumably necessary in the refolding and reassembly of thermally damaged proteins through multiple cycles of interactions between hsp70 and its targets.

Animals↗