Prevalence and prognosis of hypoglycaemia in patients receiving maintenance dialysis.

BACKGROUND: End-stage renal disease is a common predisposing condition for the development of hypoglycaemia. AIM: To determine the effect of hypoglycaemia on the mortality of patients undergoing maintenance dialysis. METHODS: Retrospective and descriptive analyses were performed in five dialysis centres in the Republic of Korea between June 2002 and August 2008. We enrolled 1685 patients who had undergone dialysis for at least 1 month. RESULTS: We identified 453 episodes of hypoglycaemia in 256 of 1685 patients (15.2%); 189 patients (73.8%) had diabetes, whereas the other patients did not. The occurrence of hypoglycaemia in patients receiving dialysis appeared to be a life-threatening complication because 27.0% of patients died within two days of the onset of a hypoglycaemic episode. Older age, low serum albumin levels and infections were independent risk factors for total mortality in these patients. Furthermore, the absence of diabetes, age and serum glucose levels were independent factors associated with early mortality within two days of the development of hypoglycaemia. CONCLUSION: Although several factors were associated with mortality, the degree of hypoglycaemia, absence of diabetes and old age were associated with early mortality. Elderly hypoglycaemic patients, especially those without diabetes, should be closely monitored.

Takotsubo cardiomyopathy in the setting of acute hydrocephalus secondary to neurocysticercosis.

We report the case of a 45-year-old male who presented with transient neurogenic stunned myocardium, or takotsubo cardiomyopathy, secondary to acute hydrocephalus caused by obstruction of the third ventricle by neurocysticercosis.

Guided-mode resonant coherent light absorbers.

We present a new class of coherent perfect absorbers based on guided-mode resonance in thin semiconductor films. Using particle-swarm optimization methods, we design a thin-film amorphous silicon grating that maximizes coherent modulation of the absorbance. The optimized device exhibits a maximum scattering power of ∼94% and a power absorption limit approaching 100% at the 1550-nm wavelength.

Spontaneous fungal peritonitis: a severe complication in patients with advanced liver cirrhosis.

Treatment of cirrhotic patients with spontaneous peritonitis using antibiotics occasionally fails. Fungal infections may be one of the causes of antibiotic treatment failure in such patients. In this study we evaluated the clinical significance and characteristics of spontaneous fungal peritonitis (SFP). Consecutive cirrhotic patients with spontaneous peritonitis treated between 2000 and 2005 at a tertiary care center in Seoul, Korea, were included. We analyzed the clinical characteristics and the prognosis of SFP patients compared with patients with spontaneous bacterial peritonitis (SBP). During the study period 416 patients developed spontaneous peritonitis and 15 (3.6 %) had SFP. Compared with patients with SBP, nosocomial peritonitis (peritonitis that developed after hospitalization for >72 h) was more common and the Child-Pugh score was higher in SFP patients (both, P < 0.01). Ten patients were infected with Candida spp. (C. albicans, 8; C. tropicalis, 1; C. glabrata, 1), and 5 with Cryptococcus neoformans. Eleven patients were co-infected with bacteria that were susceptible to the antibiotics administered. Only 5 patients were treated using appropriate anti-fungal agents. The 1-month mortality rate for SFP patients was 73.3 % (11 out of 15; median time to death, 2 days [range, 0-22]), which was significantly higher than patients with SBP alone (28.7 %, P = 0.0007). SFP is severe complication related to high mortality in cirrhotic patients. A longer admission and a higher Child-Pugh score may be risk factors. Immediate anti-fungal treatment is warranted in patients with spontaneous peritonitis, once fungus is found in the ascitic fluid.

Comparison between sitagliptin as add-on therapy to insulin and insulin dose-increase therapy in uncontrolled Korean type 2 diabetes: CSI study.

AIM: Individuals requiring insulin therapy for type 2 diabetes often require escalation of their regimen to achieve glycaemic control. Optimal management strategies for uncontrolled type 2 diabetes would improve glycaemic control without hypoglycaemia and weight gain. This study compared the efficacy and tolerability of adding sitagliptin, an oral dipeptidyl peptidase-4 inhibitor, and an up to 20% increase in insulin dose in patients with uncontrolled type 2 diabetes on insulin therapy. METHODS: We conducted a 24-week, randomized, active-competitor, parallel-group study in subjects with uncontrolled type 2 diabetes [haemoglobin A1c (HbA1c) = 7.5-11%] currently using insulin therapy. Subjects were randomly assigned to either the sitagliptin adding (100 mg daily, n = 70) or an insulin-increasing arm (≥ 10% at week 12 and ≥ 10% at week 24, n = 70) while continuing other medications. RESULTS: Average baseline HbA1c was 9.2% in both groups. HbA1c decreased more at 24 weeks in the sitagliptin adding than the insulin-increasing arm (-0.6 ± 0.1% vs. -0.2 ± 0.1%, p < 0.01). Insulin was increased by 25% at 24 weeks in the insulin-increasing group. Hypoglycaemic events were less common and less severe in sitagliptin adding arm than insulin-increasing arm (7.0 vs. 14.3 events per patient-year, p < 0.05). Weight was stable in the sitagliptin adding subjects (68.6 ± 11.6 vs. 68.1 ± 11.4 kg) but increased in the insulin-increasing subjects (66.2 ± 10.6 vs. 67.4 ± 9.7 kg, p < 0.05). Other adverse events occurred at similar rates in both arms. CONCLUSIONS: Compared to a 25% increase in insulin dose, adding sitagliptin to an insulin-based regimen was more effective at lowering HbA1c and associated with less hypoglycaemia and weight gain over 24 weeks. CLINICAL TRIAL NUMBER: NCT01100125.

Methylation by protein arginine methyltransferase 1 increases stability of Axin, a negative regulator of Wnt signaling.

Axin, a negative regulator of Wnt signaling, is a key scaffold protein for the ß-catenin destruction complex. It has been previously shown that multiple post-translational modification enzymes regulate the level of Axin. Here, we provide evidence that protein arginine methyltransferase 1 (PRMT1) directly interacts with and methylates the 378th arginine residue of Axin both in vitro and in vivo. We found that the transient expression of PRMT1 led to an increased level of Axin and that knockdown of endogenous PRMT1 by short hairpin RNA reduced the level of Axin. These results suggest that methylation by PRMT1 enhanced the stability of Axin. Methylation of Axin by PRMT1 also seemingly enhanced the interaction between Axin and glycogen synthase kinase 3ß, leading to decreased ubiquitination of Axin. Consistent with the role of PRMT1 in the regulation of Axin, knockdown of PRMT1 enhanced the level of cytoplasmic ß-catenin as well as ß-catenin-dependent transcription activity. In summary, we show that the methylation of Axin occurred in vivo and controlled the stability of Axin. Therefore, methylation of Axin by PRMT1 may serve as a finely tuned regulation mechanism for Wnt/ß-catenin signaling.

Maintenance anaesthetics during remifentanil-based anaesthesia might affect postoperative pain control after breast cancer surgery.

BACKGROUND: Although remifentanil provides profound analgesia during operation, postoperative occurrence of hyperalgesia and tolerance after remifentanil administration could be a challenge to the postoperative pain control. In this investigation, we sought to determine the effect of maintenance with propofol or sevoflurane on postoperative analgesia after remifentanil-based anaesthesia. METHODS: Two hundred and fourteen women undergoing breast cancer surgery under remifentanil-based general anaesthesia were randomly included in this prospective and double-blind trial. The patients were anaesthetized with sevoflurane (S) or propofol (P) under high (H) or low (L) effect-site concentration (Ce) of remifentanil-based anaesthesia using a target-controlled infusion system; the patients were allocated into the SH, SL, PH, and PL groups. Pain intensity (visual analogue score, VAS) and cumulative morphine requirements were recorded 30 min, 1, 6, 12, and 24 h after operation. RESULTS: The patient characteristics were similar. Cumulative morphine consumption at 24 h after surgery was higher in the SH group [38.6 (sd 14.9)] compared with the SL [31.5 (3.7)], PH [31.7 (8.3)], and PL groups [30.1 (6.1)] (P<0.001). The VAS scores during 24 h after surgery were also higher in the SH group than the SL, PH, and PL groups (P<0.001). CONCLUSIONS: Remifentanil hyperalgesia was induced by high dose of remifentanil-based anaesthesia during sevoflurane anaesthesia, whereas that was not apparent during propofol anaesthesia. Also, remifentanil hyperalgesia did not occur during low dose of remifentanil-based anaesthesia. Maintenance of propofol during high-dose remifentanil-based anaesthesia provided better postoperative analgesia.

Leukocyte toll-like receptor expression in end-stage kidney disease.

BACKGROUND: End-stage renal disease (ESRD) is simultaneously associated with inflammation, impaired immunity and increased susceptibility to microbial infections. Innate immune cells, monocytes and polymorphonuclear leukocytes (PMN) recognize pathogens via toll-like receptors (TLR) triggering phagocytosis, cellular activation and secretion of inflammatory cytokines. Data on expression and function of TLRs in ESRD are limited. METHODS: Blood samples from 21 stable ESRD patients and 21 normal controls were processed for TLR2, TLR4, TLR7 and TLR 9 expression on monocytes and PMN by flow cytometry. TLR activity was examined by determining the response to TLR4 and TLR2 ligands. RESULTS: The ESRD group exhibited significant upregulation of TLR2 and TLR4 (but not TLR7 or TLR 9) expressions on monocytes and of TLR4 on PMN. This was coupled with heightened cytokine production in response to TLR4 activation with lipopolysaccharide. However, the response to TLR2 stimulation with peptidoglycan was unchanged in the ESRD group. CONCLUSIONS: Monocyte TLR2 and TLR4 and neutrophil TLR4 expressions and TLR4 activity are increased hemodialysis patients, representing another dimension of ESRD-associated inflammation.

Molecular cloning and functional characterization of a sucrose isomerase (isomaltulose synthase) gene from Enterobacter sp. FMB-1.

AIMS: Isomaltulose (palatinose) is a slowly digestible sucrose isomer that can reduce both the glycemic and insulinemic response to foods. The aim of this study was to clone and express a sucrose isomerase (SIase) gene and characterize the protein that is responsible for the production of isomaltulose in the micro-organism Enterobacter sp. FMB-1. METHODS AND RESULTS: A cosmid clone containing c. 6 kbp region encoding an SIase gene was identified. The 5969-bp chromosomal DNA fragment covering the SIase (esi) gene in Enterobacter sp. FMB-1 was sequenced. Although this DNA fragment contained several open reading frames other than esi, only the presence of esi was sufficient to produce isomaltulose in recombinant Escherichia coli. The esi gene was expressed in E. coli, leading to the characterization of its SIase activity. CONCLUSIONS: The Enterobacter sp. FMB-1 esi gene was successfully cloned and expressed in E. coli. This gene encoded a functional SIase that produced isomaltulose from sucrose. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first molecular analysis of an SIase gene in an Enterobacter strain. The functional expression of the Enterobacter sp. FMB-1 esi gene in E. coli offers an alternative choice for the industrial production of isomaltulose.

Risk factors for post-pneumonectomy acute lung injury/acute respiratory distress syndrome in primary lung cancer patients.

Acute lung injury/acute respiratory distress syndrome (ALI / ARDS) is the most serious pulmonary complication after lung resection. This study investigated the incidence and outcome of patients with ALI / ARDS who required mechanical ventilation within one week of undergoing pneumonectomy for primary lung cancer and analysed the risk factors. We retrospectively reviewed the medical records of 146 patients who underwent pneumonectomy for primary lung cancer between May 2001 and April 2006. Preoperative, perioperative and postoperative clinical data were analysed. Post-pneumonectomy ALI / ARDS developed within the first postoperative week in 18 (12%) patients. Patients who developed ALI / ARDS had a longer hospital duration of stay (median [interquartile range], 26 [18 to 75] vs. 8 [7 to 11] days; P < 0.001) and higher in-hospital mortality (12 [67%] vs. 0 [0%]; P < 0.001). In an univariate analysis, post-pneumonectomy ALI / ARDS was associated with larger tidal volume (V(T)) and higher airway pressure (P(aw)) during one-lung ventilation (V(T) 8.2 [7.5 to 9.0] vs. 7.7 [6.9 to 8.2] ml/kg predicted body weight, P = 0.016; P(aw), 28.9 [27.6 to 30.0] vs. 27.2 [25.6 to 28.5] cmH2O, P = 0.001). V(T) during two-lung ventilation was also greater in patients who developed ALI / ARDS (P = 0.014) than in those who did not, but P(aw) during two-lung ventilation did not differ (P = 0.950). In a multiple logistic regression analysis, post-pneumonectomy ALI / ARDS was independently associated with a larger V(T) (OR 3.37 per 1 ml/kg predicted body weight increase; 95% confidence interval 1.65 to 6.86) and higher P(aw) (OR 2.32 per 1 cmH2O increase; 95% confidence interval 1.46 to 3.67) during the period of one-lung ventilation. In conclusion, a large V(T) and high P(aw) during one-lung ventilation were associated with an increased risk of post-pneumonectomy ALI / ARDS in primary lung cancer patients.

A potential role for skeletal muscle caveolin-1 as an insulin sensitivity modulator in ageing-dependent non-obese type 2 diabetes: studies in a new mouse model.

AIMS/HYPOTHESIS: Type 2 diabetes mellitus is a common age-dependent disease. We discovered that male offspring of non-diabetic C57BL/6 and DBA/2 mice, called JYD mice, develop type 2 diabetes when they grow old. JYD mice show characteristics of insulin resistance, hyperglycaemia and hyperinsulinaemia in old age without obesity. We postulated that the mechanism of age-dependent type 2 diabetes in this model relates to caveolin-1 status in skeletal muscle, which appears to regulate insulin sensitivity in the mice. METHODS: We compared insulin sensitivity in aged C57BL/6 and JYD mice using glucose and insulin tolerance tests and (18)F-fluorodeoxyglucose positron emission tomography. We also determined insulin signalling molecules and caveolin proteins using western blotting, and altered caveolin-1 levels in skeletal muscle of C57BL/6 and JYD mice using viral vector systems, to examine the effect of this on insulin sensitivity. RESULTS: In 30-week-old C57BL/6 and JYD mice, the basal levels of IRS-1, Akt and peroxisome proliferator-activated receptor-gamma decreased, as did insulin-stimulated phosphorylation of Akt and insulin receptor beta. However, caveolin-1 was only increased about twofold in 30-week-old JYD mice as compared with 3-week-old mice, whereas an eightfold increase was seen in C57BL/6 mice. Downregulation of caveolin-1 production in C57BL/6 mice caused severe impairment of glucose and insulin tolerance. Upregulation of caveolin-1 in aged diabetic JYD mice significantly improved insulin sensitivity with a concomitant increase of glucose uptake in the skeletal muscle. CONCLUSIONS/INTERPRETATION: The level of skeletal muscle caveolin-1 is correlated with the progression of age-dependent type 2 diabetes in JYD mice.

Human chorionic gonadotropin is an immune modulator and can prevent autoimmune diabetes in NOD mice.

AIMS/HYPOTHESIS: Expression of T helper (Th)1 cytokine mRNA in pregnant women is known to be inversely correlated with serum human chorionic gonadotropin (hCG). Type 1 diabetes is a Th1-mediated autoimmune disease, in which intervention at an early stage of the autoimmune process can prevent disease progression. We hypothesised that immune modulation by treating young NOD mice with hCG may prevent diabetes. METHODS: Female NOD mice were treated with hCG or recombinant hCG from 3 to 15 weeks of age and the incidence of diabetes and development of insulitis was determined. CD4(+) and CD8(+) T cell populations, T cell proliferation, cytokine production and CD4(+)CD25(+) regulatory T cells were examined and adoptive transfer experiments were performed. RESULTS: Both purified and recombinant hCG prevented development of diabetes in NOD mice. hCG decreased the proportion and number of CD4(+) and CD8(+) T cells and inhibited T cell proliferative responses against beta cell antigens. hCG treatment suppressed IFN-gamma production, but increased IL-10 and TGF-beta production in splenocytes stimulated with anti-CD3 antibody. hCG treatment also suppressed TNF-alpha production in splenocytes stimulated with lipopolysaccharide. Furthermore, hCG treatment increased the CD4(+)CD25(+)/CD4(+) T cell ratio in spleen and pancreatic lymph nodes. Depletion of CD4(+)CD25(+) T cells from splenocytes of hCG-treated NOD mice abolished their preventive effect on diabetes transfer. CONCLUSIONS/INTERPRETATION: We conclude that hCG has an immunomodulatory effect by downregulating effector cells, including Th1 cells, CD8(+) T cells and macrophages, and increasing the CD4(+)CD25(+)/CD4(+) T cell ratio, thus preventing autoimmune diabetes in NOD mice.

Spontaneous leukocyte activation and oxygen-free radical generation in end-stage renal disease.

Oxidative stress and inflammation are common features and major mediators of atherosclerosis in end-stage renal disease (ESRD). Available evidence for oxidative stress in ESRD is indirect and based on accumulation of byproducts of interactions of reactive oxygen species (ROS) with various molecules. Inflammation is a major cause of oxidative stress. To explore the direct link between oxidative stress and inflammation in ESRD, we studied leukocyte integrin expression and ROS production in 18 ESRD patients and 18 controls. ESRD patients showed elevated plasma malondialdehyde (MDA) and increased superoxide and hydrogen peroxide (H(2)O(2)) production by granulocytes and monocytes before dialysis. Hemodialysis resulted in a further rise in plasma MDA and H(2)O(2) production by granulocytes and monocytes. Surface expression of Mac-1 (CD11b and CD18) on granulocytes and monocytes was significantly increased (denoting cell activation) in ESRD patients. Granularity of granulocytes was significantly reduced before dialysis and declined further after dialysis. The magnitude of ROS production by granulocytes and monocytes was directly related with CD11b expression as well as plasma ferritin and parathyroid hormone levels and was inversely related to protein catabolic rate. Thus, this study provides direct evidence of spontaneous leukocyte activation and increased ROS generation (hence the link between oxidative stress and inflammation) in ESRD patients.

Cryopreservation of potato cultivated varieties and wild species: critical factors in droplet vitrification.

The applicability of cryopreservation protocols to a broad range of genotypes is a key issue for genebanks. We tried to identify the critical factors causing differences in survival of cryopreserved shoot tips using potato varieties coming from cultivated and wild species. The droplet-vitrification method, a combination of droplet-freezing and solution-based vitrification, was selected from several protocols. High survival after freezing was observed after dehydration with PVS2 for 20 min, cooling shoot tips placed in a droplet of PVS2 solution on aluminum foil strips by immersing the foil strips in liquid nitrogen, warming them by plunging the foil strips into a 0.8 M sucrose solution (at 40 degrees C) for 30 s and unloading in 0.8 M sucrose for 30 min. This optimized protocol was successfully applied to 12 accessions with survival ranging between 64.0 and 94.4%.

Naphthalenemethyl ester derivative of dihydroxyhydrocinnamic acid, a component of cinnamon, increases glucose disposal by enhancing translocation of glucose transporter 4.

AIMS/HYPOTHESIS: Cinnamon extracts have anti-diabetic effects. Phenolic acids, including hydrocinnamic acids, were identified as major components of cinnamon extracts. Against this background we sought to develop a new anti-diabetic compound using derivatives of hydroxycinnamic acids purified from cinnamon. METHODS: We purified hydroxycinnamic acids from cinnamon, synthesised a series of derivatives, and screened them for glucose transport activity in vitro. We then selected the compound with the highest glucose transport activity in epididymal adipocytes isolated from male Sprague-Dawley rats in vitro, tested it for glucose-lowering activity in vivo, and studied the mechanisms involved. RESULTS: A naphthalenemethyl ester of 3,4-dihydroxyhydrocinnamic acid (DHH105) showed the highest glucose transport activity in vitro. Treatment of streptozotocin-induced diabetic C57BL/6 mice and spontaneously diabetic ob/ob mice with DHH105 decreased blood glucose levels to near normoglycaemia. Further studies revealed that DHH105 increased the maximum speed of glucose transport and the translocation of glucose transporter 4 (GLUT4, now known as solute carrier family 2 [facilitated glucose transporter], member 4 [SLC2A4]) in adipocytes, resulting in increased glucose uptake. In addition, DHH105 enhanced phosphorylation of the insulin receptor-beta subunit and insulin receptor substrate-1 in adipocytes, both in vitro and in vivo. This resulted in the activation of phosphatidylinositol 3-kinase and Akt/protein kinase B, contributing to the translocation of GLUT4 to the plasma membrane. CONCLUSIONS/INTERPRETATION: We conclude that DHH105 lowers blood glucose levels through the enhancement of glucose transport, mediated by an increase in insulin-receptor signalling. DHH105 may be a valuable candidate for a new anti-diabetic drug.

Naïve and central memory T-cell lymphopenia in end-stage renal disease.

End-stage renal disease (ESRD) is associated with increased propensity to infections, diminished response to vaccination, impaired cell-mediated immunity, and reduced CD4+/CD8+ T-lymphocyte ratio. Four subsets of CD4+ and CD8+ T cells have been recently identified: naïve cells (as yet uncommitted), central memory (CM) cells (previously programmed), and CD45RA-positive and CD45RA-negative effector memory (EM) cells (programmed to perform specific effector functions). The effect of ESRD on subpopulations of T lymphocytes is unclear and was studied here. Twenty-one hemodialysis patients and 21 age-matched controls were studied. Pre- and post-dialysis blood samples were obtained and analyzed by three-color flow cytometry. CD4+/CD8+ ratio and the numbers of the naïve and CM CD4+ and CD8+ T cells were significantly reduced, whereas the numbers of EM CD4+ and CD8+ T cells were unchanged in the ESRD group. The reduction of the naïve and CM T-cell counts in the ESRD group was associated with increased apoptosis of these cells. Negative correlations were found between severity of azotemia, oxidative stress, and hyperphosphatemia with the number of naïve T cells. Comparison of diabetic with non-diabetic ESRD patients revealed higher numbers of total CD8+ cells and EM CD8+ T cells in the diabetic group. Dialysis did not significantly change the naïve and CM CD4+ or CD8+ cell counts, but significantly lowered CD8+ EM cell count. Thus, ESRD results in increased apoptosis and diminished populations of naïve and CM T lymphocytes. This phenomenon may, in part, contribute to the impaired immune response in this population.

Approaches for the cure of type 1 diabetes by cellular and gene therapy.

Type 1 diabetes results from insulin deficiency caused by autoimmune destruction of insulin-producing pancreatic beta cells. Islet transplantation, beta cell regeneration, and insulin gene therapy have been explored in an attempt to cure type 1 diabetes. Major progress on islet transplantation includes substantial improvements in islet isolation technology to obtain viable and functionally intact islets and less toxic immunosuppressive drug regimes to prevent islet graft failure. However, the availability of human islets from cadaveric pancreata is limited. Regeneration of pancreatic beta cells from embryonic or adult stem cells may overcome the limited source of islets and transplant rejection if beta cells are regenerated from endogenous stem cells. However, it is difficult to overcome the persisting hostile beta cell-specific autoimmune response that may destroy the regenerated beta cells. Insulin gene therapy might overcome the weakness of islet transplantation and beta cell regeneration with respect to their vulnerability to autoimmune attack. This method replaces the function of beta cells by introducing various components of the insulin synthetic and secretory machinery into non- beta cells, which are not targets of beta cell-specific autoimmune responses. However, there is no regulatory system that results in the expression and release of insulin in response to glucose with satisfactory kinetics. Although there is no perfect solution for the cure of type 1 diabetes at the present time, research on a variety of potential approaches will offer the best choices for the cure of human type 1 diabetes.

Acid resistance of Escherichia coli O157:H7 from the gastrointestinal tract of cattle fed hay or grain.

There has been strong debate as to whether feeding cattle hay prior to slaughter will reduce the number and/or virulence of Escherichia coli O157:H7 in the bovine gastrointestinal tract (GIT). This study addressed this issue by comparing numbers, persistence, and acid resistance of generic coliforms and E. coli O157:H7 from various gastrointestinal tract sites of cattle fed grain or hay. Mature Angus steers, doubly cannulated into the rumen and duodenum were inoculated with E. coli O157:H7. Aliquots of digesta from the rumen, duodenum, and rectum were cultured directly or acid shocked (pH 2.0) and then cultured to determine acid resistance. The culture technique used was as sensitive as standard immunomagnetic bead separation protocols. E. coli O157:H7 from hay-fed or grain-fed cattle were similarly acid resistant in all GIT locations. In contrast, generic coliforms from the rumen and rectum of hay-fed animals were more sensitive to an acid shock than coliforms from those GIT locations in grain-fed animals. E. coli O157:H7 colonized the most distal region of the GIT and was not consistently cultured from the rumen or the duodenum. Numbers in the upper GIT did not predict numbers or persistence of E. coli O157:H7 in rectal samples. Grain-feeding or hay-feeding did not affect survival of E. coli O157:H7 in the rumen, nor its passage through the abomasum (pH 2.0) to the duodenum. These data show that generic coliforms behave differently in the bovine host than E. coli O157:H7 and that E. coli O157:H7 acid resistance was independent of animal diet.

Prevention of autoimmune diabetes by immunogene therapy using recombinant vaccinia virus expressing glutamic acid decarboxylase.

AIMS/HYPOTHESES: Type I (insulin-dependent) diabetes mellitus results from T-cell-mediated autoimmune destruction of pancreatic beta cells. Among the beta-cell autoantigens that have been implicated in triggering of beta-cell-specific autoimmunity, glutamic acid decarboxylase (GAD) is a strong candidate in both humans and the NOD mouse. We aimed to determine whether treatment with a recombinant vaccinia virus expressing GAD (rVV-GAD65) could prevent the development of diabetes in NOD mice. METHODS: Three-eight-to-nine-week-old female NOD mice were injected with various doses of rVV-GAD65 or rVV-MJ601as a control. We then examined the incidence of diabetes, T-cell proliferative response to GAD, amounts of anti-GAD IgGs, cytokine production and generation of regulatory cell populations. RESULTS: Administration of rVV-GAD65 to NOD mice prevented diabetes in an age-dependent and dose-dependent manner. Splenic T cells from rVV-GAD65-treated mice did not proliferate in response to GAD65. The amount of IgG1 was increased, whereas IgG2a amounts did not change in rVV-GAD65-treated NOD mice. The production of interleukin-4 increased, whereas the production of interferon-gamma decreased in rVV-GAD65-treated mice after stimulation with GAD. Furthermore, splenocytes from rVV-GAD65-treated NOD mice prevented the transfer of diabetes by splenocytes from acutely diabetic NOD mice in NOD. scid recipients. CONCLUSION/INTERPRETATION: Immunogene therapy using a recombinant vaccinia virus expressing GAD results in the prevention of autoimmune diabetes in NOD mice by the induction of immunological tolerance through active suppression of effector T cells, and this treatment might have therapeutic value for the prevention of Type I diabetes.

Adhesion of viridans group streptococci to sialic acid-, galactose- and N-acetylgalactosamine-containing receptors.

The binding of 10 viridans group streptococci to sialic acid-, galactose (Gal)- and N-acetylgalactosamine (GalNAc)-containing receptors was defined by analysis of the interactions between these bacteria and structurally defined glycoconjugates, host cells and other streptococci. All interactions with sialic acid-containing receptors were Ca(2+)-independent as they were not affected by ethyleneglycoltetraacetic acid (EGTA), whereas all interactions with Gal- and GalNAc-containing receptors were Ca(2+)-dependent. Recognition of sialic acid-, Gal- and GalNAc-containing receptors varied widely among the strains examined, in a manner consistent with the association of each of the three lectin-like activities with a different bacterial cell surface component.