Biomedical subjects

H Cheng

Publications and source records attributed to H Cheng.

At least 127 records · Page 7Linked to original sources

PubMed2000

Effects of epidermal growth factor, transferrin, and insulin on lipofection efficiency in human lung carcinoma cells.

Poor transfection efficiency is the major drawback of lipofection. We showed previously that addition of transferrin (TF) to Lipofectin enhanced the expression of a reporter gene in HeLa cells by 120-fold and achieved close to 100% transfection efficiency. The purpose of this study was to determine whether TF and other ligands could improve the efficiency of lipofection in lung carcinoma cells. Confluent A549, Calu3, and H292 cells were transfected for 18 hours with a plasmid DNA (pCMVlacZ) using Lipofectin plus TF, insulin, or epidermal growth factor as the vector. The transfected cells were assessed for transfection efficiency by beta-galactosidase activity (light units/microg protein) and the percentage of blue cells following 5-bromo-4-chloro-3-indolyl beta-D-galactopyranoside staining. Lipofectin supplemented with epidermal growth factor yielded the largest enhancement of lipofection efficiency (< or =23-fold over that by Lipofectin alone) in all three cell lines. Insulin significantly enhanced the lipofection efficiency in A549 and Calu3 cells but not in H292 cells, whereas TF showed significant lipofection efficiency-enhancing effect in Calu3 and H292 cells but not in A549 cells. The transfection efficiency correlated well with the amounts of DNA delivered to the nucleus as well as the amounts of the receptor. These results indicate that the gene delivery strategy employing ligand-facilitated lipofection can achieve high transfection efficiency in human lung carcinoma cells. In addition, enhancement of the expression of the receptor may be a possible strategy for increasing the efficiency of gene targeting.

Cell Nucleus↗

PubMed2000

Interactions of the renin-angiotensin system and neuronal nitric oxide synthase in regulation of cyclooxygenase-2 in the macula densa.

Cyclooxygenase-2 (COX-2) expression in rat kidney is localized to the macula densa and the immediately proximal cTALH and increases after salt restriction. Either ACE inhibitors or AT1 receptor blockers increase COX-2 expression in both control and salt-restricted animals, suggesting that the RAS activation feedback inhibits renal cortical COX-2 expression. To determine whether increased COX-2 expression in response to ACE inhibition mediated increases in renin production, rats were treated with Captopril for 1 week with or without the specific COX-2 inhibitor, SC58236. Plasma renin activity increased significantly in the Captopril group. This increase was partially reversed by simultaneous treatment with SC58236. Kidney renin activity also increased in the Captopril group compared with control, which was also significantly inhibited by SC58236 treatment. Because of the localization of bNOS to MD and surrounding cTALH, the current study investigated the role of NO in the regulation of COX-2 expression. Rats were fed a normal diet, low salt diet or low salt diet combined with captopril and half of them were treated with the neuronal NOS inhibitor, 7-NI, and half with vehicle. After 7 days, mRNA was extracted and the microsome proteins purified from renal cortex. COX-2 mRNA expression was measured by Northern-blot and normalized with GAPDH. 7-NI treatment decreased COX-2 mRNA and immunoreactive COX-2 expression in each group. In summary, these studies indicate that COX-2 from macula densa/cTALH is a regulator of renin production and release. Angiotensin II may be a negative regulator of cTALH/macula densa COX-2 expression, and NO may mediate increased renal cortical COX-2 expression seen in volume depletion. These studies suggest important interactions between the NO and COX-2 systems in the regulation of arteriolar tone and the renin-angiotensin system by the macula densa.

Angiotensin-Converting Enzyme Inhibitors↗

PubMed2000

Modulation of the epidermal growth factor receptor by the human papillomavirus type 16 E5 protein in raft cultures of human keratinocytes.

It has been shown that the E5 protein of the human papillomavirus type 16 modulates epidermal growth factor receptor downregulation in monolayer cultures of human keratinocytes and mouse fibroblasts. We have now analysed the effect of this protein on the expression, the distribution and the activation of EGF receptors in raft cultures derived from an E5-transfected human keratinocyte cell line. The epithelia generated in these cultures were stratified and exhibited suprabasal expression of cytokeratins 1 and 10, which are known markers of early epidermal differentiation. In situ hybridization with an antisense riboprobe to the human papilloma virus type 16 E5 protein revealed a homogeneous gene expression within the entire epithelium of E5-transfected but not empty vector-transfected control cultures. Treatment of serum-starved rafts with EGF for 48 hours led to a strong decrease of suprabasal EGF receptors in control cultures, but not in rafts of E5-expressing cells. Under these conditions, no activated receptors were observed in control cultures, but activated receptors were still present in E5-raft cultures. Our results indicate that human papilloma virus type 16 E5-mediated modulation of EGF receptor expression occurs in a time- and structure-dependent manner in epithelial equivalents of human keratinocytes.

Cell Differentiation↗

PubMed2000

Salvage surgery for recurrent nasopharyngeal carcinoma.

OBJECTIVE: To evaluate the efficacy of salvage surgery in the treatment of recurrent nasopharyngeal carcinoma (NPC) at the primary site. STUDY DESIGN: A retrospective investigation of the outcome of salvage surgery for 28 patients with recurrent NPC after definite radiation therapy. METHODS: The nasopharynx was approached anteroposteriorly by the transmaxillary approach (maxillary swing, maxillectomy) or inferior approach (midline mandibulotomy or median labiomandibular glossotomy), or laterally by modified facial translocation or transpterygoid approach; intentional ligation of the internal carotid artery was performed after establishment of extracranial-intracranial (EC-IC) bypass in one patient; postoperative irradiation was given to the patients with positive pathological margins. RESULTS: Nine patients lived without disease for 20 to 93 months (mean interval, 52 mo) after surgery; among them, eight patients had T1 tumors that were resected totally by surgery via anteroposterior approaches and the other patient had postoperative irradiation to control the disease. Seven patients had local recurrence 8 to 21 months after treatment. Four patients developed distant metastases, including one patient with a T2b tumor that was totally resected through modified facial translocation approach with ligation of internal carotid artery. Eight patients died of other causes; internal carotid artery blowout was the cause of death in four of these eight patients. CONCLUSIONS: In most cases of recurrence, T1 nasopharyngeal tumors can be resected totally by anteroposterior approaches; for T2 or larger tumors, postoperative irradiation is usually necessary. Otherwise, facial translocation offers a better chance to completely resect the tumors. Internal carotid artery is better ligated if patients have received greater than 70 Gy irradiation or if the artery must be exposed during the surgery. We suggest that EC-IC bypass be used to avoid the possible complications (or cerebral ischemic stroke) caused by ligation of internal carotid artery. The transmaxillary approach is favored in the management of nasopharyngeal tumor recurrence with nasal cavity extension, and midline mandibulotomy is more suitable for resection of posterior margin of nasopharyngeal tumor recurrence. Facial translocation offers the widest operative field and is the most versatile approach for radical resection of nasopharyngeal tumor recurrence, but the surgeon should be skilled in the management of the facial nerves to reduce morbidity.

Adult↗

PubMed2000

Spontaneous activation of beta(2)- but not beta(1)-adrenoceptors expressed in cardiac myocytes from beta(1)beta(2) double knockout mice.

Although ligand-free, constitutive beta(2)-adrenergic receptor (AR) signaling has been demonstrated in naive cell lines and in transgenic mice overexpressing cardiac beta(2)-AR, it is unclear whether the dominant cardiac beta-AR subtype, beta(1)-AR, shares the ability of spontaneous activation. In the present study, we expressed human beta(1)- or beta(2)-AR via recombinant adenoviral infection in ventricular myocytes isolated from beta(1)beta(2)-AR double knockout mice, creating pure beta(1)-AR and beta(2)-AR systems with variable receptor densities. A contractile response to a nonselective beta-AR agonist, isoproterenol, was absent in double knockout mouse myocytes but was fully restored after adenoviral beta(1)-AR or adenoviral beta(2)-AR infection. Increasing the titer of adenoviral vectors (multiplicity of infection 10-1000) led to a dose-dependent expression of beta(1)- or beta(2)-AR with a maximal density of 1207 +/- 173 (36-fold over the wild-type control value) and 821+/-38 fmol/mg protein (69-fold), respectively. Using confocal immunohistochemistry, we directly visualized the cellular distribution of beta(1)-AR and beta(2)-AR and found that both subtypes were distributed on the cell surface membrane and transverse tubules, resulting in a striated pattern. In the absence of ligand, beta(2)-AR expression resulted in graded increases in baseline cAMP and contractility up to 428% and 233% of control, respectively, at the maximal beta(2)-AR density. These effects were specifically reversed by a beta(2)-AR inverse agonist, ICI 118,551 (10(-7) M). In contrast, overexpression of beta(1)-AR, even at a greater density, failed to enhance either basal cAMP or contractility; the alleged beta(1)-AR inverse agonist, CGP 20712A (10(-6) M), had no significant effect on basal contraction in these cells. Thus, we conclude that acute beta(2)-AR overexpression in cardiac myocytes elicits significant physiological responses due to spontaneous receptor activation; however, this property is beta-AR subtype specific because beta(1)-AR does not exhibit agonist-independent spontaneous activation.

Adrenergic Agonists↗

PubMed2000

HuR regulates p21 mRNA stabilization by UV light.

Expression of the cyclin-dependent kinase inhibitor p21 is highly induced by many stresses, including exposure to short-wavelength UV light (UVC), which increases p21 mRNA stability. Investigation into the mechanisms underlying this stabilization process revealed that proteins present in cytoplasmic lysates of human RKO colorectal carcinoma cells formed complexes with p21 mRNA that were inducible by treatment with UVC and other stress agents. The ubiquitous Elav-type RNA-binding protein HuR was identified within the p21 mRNA-protein complexes, as antibodies recognizing HuR supershifted these complexes and revealed HuR-immunoreactive proteins complexing with p21 mRNA on Western blots. Lowering of endogenous HuR levels through expression of antisense HuR decreased p21 RNA-protein complexes, greatly reduced the UVC inducibility and half-life of p21 mRNA, and prevented UVC-mediated induction of luciferase activity in p21 3' untranslated region-containing reporter constructs. Our findings indicate that HuR plays a major role in regulating stress-induced p21 expression by enhancing p21 mRNA stability and that these effects are coupled to HuR's elevated presence in the cytoplasm.

Antigens, Surface↗

PubMed2000

Culture and adenoviral infection of adult mouse cardiac myocytes: methods for cellular genetic physiology.

Rapid development of transgenic and gene-targeted mice and acute genetic manipulation via gene transfer vector systems have provided powerful tools for cardiovascular research. To facilitate the phenotyping of genetically engineered murine models at the cellular and subcellular levels and to implement acute gene transfer techniques in single mouse cardiomyocytes, we have modified and improved current enzymatic methods to isolate a high yield of high-quality adult mouse myocytes (5.3 +/- 0.5 x 10(5) cells/left ventricle, 83.8 +/- 2.5% rod shaped). We have also developed a technique to culture these isolated myocytes while maintaining their morphological integrity for 2-3 days. The high percentage of viable myocytes after 1 day in culture (72.5 +/- 2.3%) permitted both physiological and biochemical characterization. The major functional aspects of these cells, including excitation-contraction coupling and receptor-mediated signaling, remained intact, but the contraction kinetics were significantly slowed. Furthermore, gene delivery via recombinant adenoviral infection was highly efficient and reproducible. In adult beta(1)/beta(2)-adrenergic receptor (AR) double-knockout mouse myocytes, adenovirus-directed expression of either beta(1)- or beta(2)-AR, which occurred in 100% of cells, rescued the functional response to beta-AR agonist stimulation. These techniques will permit novel experimental settings for cellular genetic physiology.

Adenoviridae↗

PubMed2000

Cementum-forming cells are phenotypically distinct from bone-forming cells.

Normal human cementum-derived cells (HCDCs), expanded in vitro, formed mineralized matrix when attached to a ceramic carrier and transplanted subcutaneously into immunodeficient mice. The mineralized matrix elaborated by transplanted HCDC exhibited several features identical to cementum in situ and was significantly different from bone deposited by similarly transplanted human bone marrow stromal cells (BMSCs). No bone marrow formation and very few or no tartrate-resistant acid phosphatase (TRAP)-positive cells (osteoclasts and osteoclastic precursors) were found in HCDC transplants. In contrast, in BMSC transplants both hematopoiesis and TRAP-positive cells were routinely observed. Furthermore, compared with BMSC-derived matrix, HCDC-derived matrix was less cellular, numerous empty lacunae were present, and fewer cells were found on the cementum matrix/ceramic carrier interface. The organization of collagen fibers in HCDC-derived matrix, as visualized by using the Picrosirus red staining method, was similar to cementum, with typical unorganized bundles of collagen fibers. In contrast, bone matrix elaborated by transplanted BMSC had lamellar structure, identical to mature bone in situ. Finally, cementocytes embedded in the cementum-like matrix were immunopositive for fibromodulin and lumican, whereas osteocytes within the bonelike matrix were negative. This pattern is consistent with the cementum and bone in situ, respectively. These results indicate that human cementum cells are phenotypically distinct from bone cells and provide further validation of the combined in vitro/in vivo model of human cementogenesis recently developed in our laboratory.

Adolescent↗

PubMed2000

Performance status of health care facilities changes with risk adjustment of HbA1c.

OBJECTIVE: To develop a risk adjustment method for HbA1c, based solely on administrative data and to determine the extent to which risk-adjusted HbA1c changes the identification of high- or low-performing medical facilities. RESEARCH DESIGN AND METHODS: Through use of pharmacy records, 204,472 diabetic patients were identified for federal fiscal year 1996 (FY96). Complete information (HbA1c levels, demographic data, inpatient records, outpatient pharmacy utilization records) was available on 38,173 predominantly male patients from 48 Veterans Health Administration (VHA) medical facilities. Hierarchical mixed-effects models were used to estimate risk-adjusted unique facility-level HbA1c. RESULTS: Predicted HbA1c demonstrated expected patterns for major factors known to influence glycemic control. Poorer glycemic control was seen in minorities and patients with greater disease severity, longer duration of disease (using treatment type or presence of amputation as surrogates), and more extensive comorbidity (measured by an adapted Charlson index). Better glycemic control was seen in Caucasians, older diabetic patients, and patients with higher outpatient utilization. The number of performance outliers was reduced as a result of risk adjustment. For mean HbA1c levels, 7 facilities that were initially identified as statistically significant outliers were no longer outliers after risk adjustment. For high-risk HbA1c (>9.5%) rates, 12 facilities that were initially identified as statistically significant outliers were no longer outliers after risk adjustment. CONCLUSIONS: Risk adjustment using only administrative data resulted in substantial changes in identification of high or low performers compared with non-risk-adjusted HbA1c. Although our findings are exploratory, risk adjustment using administrative data may be a necessary and achievable step in quality assessment of diabetes care measured by rates of high-risk HbA1c (>9.5%).

Adult↗

PubMed2000

Elevated levels of urine angiostatin and plasminogen/plasmin in cancer patients.

Previously, a specific angiogenesis inhibitor, angiostatin, discovered in urine and serum of tumor-bearing mice, was reported to potently block tumor growth and metastasis in animal models. Detection of angiostatin and its precursor proteins in urine from cancer patients has not been reported. Now, we report the development of an antibody-based analysis system that allows us to detect angiostatin and plasminogen/plasmin (Pgn/plasmin) in the urine of cancer patients. The detection system is a combination of a novel lysine-ELISA assay and Western immunoblot analysis using a specific antibody to human angiostatin and Pgn/plasmin. High levels of Pgn/plasmin were detected in the urine from various cancer patients, whereas healthy individuals showed relatively low levels of urine Pgn/plasmin. Of interest, angiostatin is detectable in urine samples of patients with various cancers, including acute lymphoblastic leukemia, suggesting that angiogenesis may play an important role in the development and progression of leukemia. Our data for the first time show that angiostatin and Pgn/plasmin are present at relatively high levels in the urine of human cancer patients. Detection of urine angiostatin in cancer patients helps us not only to understand the role of this angiogenesis inhibitor in cancer development and progression but also allows us to develop tools of cancer diagnosis and prognosis. Thus angiostatin has both therapeutic and diagnostic implications in cancer disease.

Adolescent↗

PubMed2000

Disposition and pharmacokinetics of the antimigraine drug, rizatriptan, in humans.

The absorption and disposition of rizatriptan (MK-0462, Maxalt(TM)), a selective 5-HT(1B/1D) receptor agonist used in the treatment of migraine headaches, was investigated in humans. In a two-period, single i.v. (3 mg, 30-min infusion), and single oral (10 mg) dose study with [(14)C]rizatriptan in six healthy human males, total recovery of radioactivity was approximately 94%, with unchanged rizatriptan and its metabolites being excreted mainly in the urine (89% i.v. dose, 82% p.o. dose). Approximately 26 and 14% of i.v. and oral rizatriptan doses, respectively, were excreted in urine as intact parent drug. In a second, high-dose study (60 mg p.o.), five metabolites excreted into urine were identified using liquid chromatography-tandem mass spectrometry and NMR methods. They were triazolomethyl-indole-3-acetic acid, rizatriptan-N(10)-oxide, 6-hydroxy-rizatriptan, 6-hydroxy-rizatriptan sulfate, and N(10)-monodesmethyl-rizatriptan. Urinary excretion of triazolomethyl-indole-3-acetic acid after i.v. and oral administrations of rizatriptan accounted for 35 and 51% of the dose, respectively, whereas the corresponding values for rizatriptan-N(10)-oxide were 4 and 2% of the dose. Plasma clearance (CL) and renal clearance (CL(r)) were 1325 and 349 ml/min, respectively, after i.v. administration. A similar CL(r) value was obtained after oral administration (396 ml/min). The primary route of rizatriptan elimination occurred via nonrenal route(s) (i.e., metabolism) because the CL(r) of rizatriptan accounted for 25% of total CL. Furthermore, the CL(r) was higher than normal glomerular filtration rate ( approximately 130 ml/min), indicating that this compound was actively secreted by renal tubules. The absorption of rizatriptan was approximately 90%, but it experienced a moderate first-pass effect, resulting in a bioavailability estimate of 47%.

Administration, Oral↗

PubMed2000

Role of macrophages in restricting herpes simplex virus type 1 growth after ocular infection.

PURPOSE: To investigate the role macrophages play in controlling herpes simplex virus (HSV)-1 replication after infection of the murine cornea. METHODS: Macrophage depletion in selected tissues before or after virus infection was achieved by repeated subconjunctival (SCJ) and/or intravenous (IV) injection of liposomes containing dichloromethylene diphosphonate (L-Cl2MDP). Controls received liposomes containing phosphate-buffered saline (L-PBS). The efficiency of depletion was evaluated by histologic examination. Virus content in infected tissues was determined by standard plaque assay. Delayed-type hypersensitivity (DTH) responsiveness was assessed using the ear-swelling assay. Antibody isotype responses to virus antigens and cytokine production were monitored by enzyme-linked immunosorbent assay. RESULTS: Balb/c mice given SCJ injection of L-Cl2MDP 4 and 2 days before HSV-1 corneal infection were found to have ocular virus titers as much as 10(5)-fold higher than that seen in the L-PBS-treated controls 8 days after infection. When L-Cl2MDP treatment was delayed until 2 and 4 days after infection, virus titers in the eye were analogous to those in the control animals. Subconjunctival and submandibular lymph node macrophages in mice given local (SCJ) L-Cl2MDP pretreatment were profoundly reduced, whereas the number of corneal Langerhans' cells and lymph node dendritic cells remained unchanged. Local L-Cl2MDP pretreatment was associated with significantly reduced DTH responsiveness to HSV-1 antigen, and an alteration in selected antibody isotype production. Depletion of macrophages in the subconjunctival tissue before corneal infection was not accompanied by enhanced virus growth at early times (2 or 4 days) after infection. CONCLUSIONS: Macrophages play an important role in restricting HSV-1 growth after corneal infection. These cells appear to be required for the development of an acquired immune response, presumably by functioning in antigen processing and presentation. The hypothesis that macrophages are major participants in innate immunity to HSV-1 corneal infection was not supported.

Acid Phosphatase↗

PubMed2000

[Evaluation and comparison of the Helicobacter pylori stool antigen test and the gastric mucosal antigen test].

OBJECTIVE: To evaluate the reliability of an enzyme-linked immunosorbent assay by the Helicobacter pylori (H. pylori) stool antigen test for the detection of H. pylori infection. METHODS: Stool specimens were collected from 224 patients who received upper gastrointestinal endoscopic examination for gastrointestinal symptoms. H. pylori status was evaluated by five different tests: culture, histology, biopsy rapid urease test, H. pylori stool antigen test, and H. pylori gastric active mucosal antigen test (parts of the patients). A commercial kit using an enzyme-linked immunosorbent assay was used to examined H. pylori antigen in the stool or in the gastric active mucosa. H. pylori status was defined as positive when two of the three tests (culture, histology and biopsy rapid urease test) were positive. RESULTS: 137 patients were diagnosed as H. pylori-positive. The H. pylori stool antigen test was positive in 143 patients and negative in 81 patients. The sensitivity and specificity were 96.4% and 87.4%, respectively. The overall accuracy was 92.9%. 39 patients were examined H. pylori antigen in the gastric active mucosa, and 27/39 were diagnosed as H. pylori-positive. The H. pylori gastric active mucosal antigen test was positive in 28 patients and negative in 11 patients. The H. pylori stool antigen test was positive in 30 patients and negative in 9 patients. The corresponding rate between gastric active mucosa and stool was 94.9%. CONCLUSION: The H. pylori stool antigen test is a simple, non-invasive method for accurate diagnosis of H. pylori infection.

Adolescent↗

PubMed2000

[Effect of lanthanum on growth and biochemical property of Sclerotinia sclerotiorum].

The study shows that La2O3 at a concentration of 30-450 mg.L-1 could inhibit the growth of S. sclerotiorum in both solid and liquid media and the inhibition effect was increased with its increasing concentration. The activity of pectinase produced by S. sclerotiorum in liquid medium was also increased with increasing La2O3 concentration.

Ascomycota↗

PubMed2000

[Niche breadth of Gymnosporangium haraeanum].

The resistant difference among different main pear cultivars in Anhui Province to pear rust caused by Gymnosporangium haraeanum was significant. According to disease index and diseased leaves of susceptible cultivars, the niche breadths of hosts were 0.7555 and 0.7951, respectively. The niche breadths of horizontal and vertical space of each cultivar were approximate to 1. The result shows that the infection of G. haraeanum was a random distribution.

Basidiomycota↗

PubMed2000

Molecular cloning, sequencing and expression of obese gene in the Chinese.

OBJECTIVE: To construct the human obese (ob) cDNA clone in the Chinese, and analyze the expression of the ob gene in adipose tissue of obese, non-obese subjects and nooinsulin-dependent diabetes mellitus (NIDDM) Chinese patients. METHODS: A ob cDNA clone was isolated by reverse transcription polymerase chain reaction (RT-PCR). Four groups of Chinese subjects participated in the study: 1) 12 obese subjects [body mass index (BMI): 28.5 +/- 2.3 kg/m2]; 2) 11 non-obese subjects (BMI: 21.0 +/- 1.5 kg/m2); 3) 8 obese NIDDM patients (BMI: 27.0 +/- 1.4 kg/m2); 4) 11 non-obese NIDDM patients (BMI: 21.2 +/- 1.4 kg/m2). The expression of ob gene mRNA in abdominal subcutaneous adipose tissue was examined using RNA dot blot hybridization with a digoxigenin-labeled human ob cDNA probe. The hybridized signals were quantitated by densitometry. RESULTS: A full human ob cDNA fragment which included a glutamine codon at +49 was obtained. A base substitution (A to G) in the coding region at position 287 was found, resulting in a glutamine being replaced by an arginine. Expression of the ob gene was significantly higher in Chinese obese subjects compared to non-obese ones (P < 0.05), and positively correlated with the BMI. No significant difference in the amount of ob mRNA was detected between non-diabetic and diabetic groups at the same BMI level. CONCLUSIONS: We constructed a full length human ob cDNA clone. The expression of the ob gene was significantly higher in Chinese obese subjects than in non-obese ones. The metabolic and hormonal changes associated with NIDDM are not the main factors regulating the expression of the ob gene.

Adult↗

PubMed2000

[Primary study on characteristics of insulin secretion rate, metabolic clearance rate and sensitivity in non-insulin-dependent diabetic subjects from multiplex diabetic pedigrees].

OBJECTIVE: To investigate the characteristics of insulin secretion rate (ISR), metabolic clearance rate (MCR-I) and sensitivity and to explore their relationship with obesity in non-insulin-dependent diabetic subjects from multiplex diabetic pedigrees (MDP). METHODS: Fifteen subjects with normal glucose tolerance and 11 non-insulin-dependent diabetic patients from MDP were included in the study. Frequently sampled intravenous glucose tolerance test (FSIVGTT) was performed. Glucose, insulin (INS) and connecting-peptide (C-P) concentrations were measured. A computer procedure devised by our laboratory was used to calculate the value of ISR at each time point, then MCR-I was acquired. Insulin sensitivity index (SI) was calculated according to minimal model technique about glucose in FSIVGTT. RESULTS: The ISR curve in control group was biphasic, while in non-insulin. In non-insulin-dependent diabetic group, areas under the curves of C-P (AUCC) and ISR level (AUCS) measured during 0 approximately 16 min were 7.9 nmol.min(-1).L(-1) +/- 2.8 nmol.min(-1).L(-1), and 6.1 nmol +/- 2.2 nmol, respectively, which were significantly lower than those in control group 17.7 nmol.min(-1).L(-1) +/- 4.92 nmol.min(-1).L(-1) and 12.3 nmol +/- 3.9 nmol (P < 0.01). The two parameters were slightly higher than those in control group 155 nmol.min(-1).L(-1) +/- 44 nmol.min(-1).L(-1) vs 101 nmol.min(-1).L(-1) +/- 30 nmol.min(-1).L(-1) and 76 nmol +/- 26 nmol vs 54 nmol +/- 20.0 nmol (P < 0.05)measured during 16 approximately 180 min. There was no significant difference, between the two groups about the amount of insulin secretion during 3 hours (82 nmol +/- 28nmol vs 68 nmol +/- 21 nmol, P = 0.2). In control group, there were significant positive correlation, between AUCS, waist-hip ratio (WHR), and body surface area, (BSA) and significant negative correlation between MCR-I, SI and WHR, BSA (P < 0.01), and also between MCR-I and SI. In non-insulin-dependent diabetic group, AUCS were significantly correlated with body mass index (BMI) (P < 0.01), and MCR-I had significant negative correlation with AUCC (P < 0.01). CONCLUSIONS: There are obvious impaired first phase insulin secretion after glucose challenge in non-insulin-dependent diabetic subjects from MDP. Decrease in endogenous MCR-I might be an important factor to hyperinsulinemia and insulin resistance. Increased insulin secretion, decreased MCR-I and insulin sensitivity can be observed in abdominal obese subjects of control group.

Blood Glucose↗

PubMed2000

[Application of indigo disulphonate spectrophotometry on the determination of ozone in indoor air].

Spectrophotometric determination of ozone in indoor air by using indigo disulphonate was investigated. The results showed that the average recovery of ozone was 99% and the relative standard deviation was 2.3% when the concentration of indoor ozone was in the range of 0.2-1.0 microgram/ml. The lowest detection concentration was 0.009 mg/m3 (sampling 20 L) when the range of determination was 0.18-10.0 mg/10 ml.

Air Pollutants↗