A comparison of glycaemic effects of sitagliptin and sulfonylureas in elderly patients with type 2 diabetes mellitus.

INTRODUCTION: In the USA, 45% of patients with type 2 diabetes mellitus (T2DM) are elderly (≥ 65 years old). In general, use of sulfonylurea increases with patient age as does the associated risk for hypoglycaemia, and the consequences of hypoglycaemia can be more pronounced in elderly patients. Sitagliptin, a DPP-4 inhibitor, improves glycaemic control in adult patients of all ages with T2DM, with a low risk of hypoglycaemia when used alone or in combination with other antidiabetic agents that are not generally associated with hypoglycaemia when used independently. METHODS: In a post hoc analysis, pooled data from elderly patients who participated in one of three double-blind studies comparing the effects of therapy with sitagliptin (100 mg/day) vs. sulfonylurea (in titrated doses) were analysed for changes from baseline in HbA1c, fasting plasma glucose (FPG), and body weight and for the incidence of reported symptomatic hypoglycaemia. In these studies, patients on diet alone or metformin were randomised to sitagliptin or glipizide for 104 weeks (studies 1 and 2) or glimepiride for 30 weeks (study 3). The analysis included 372 elderly patients who completed a trial through 25 or 30 weeks. RESULTS: Both HbA1c and FPG decreased from baseline with each treatment, with no statistically significant differences between treatments. A significantly lower incidence of reported hypoglycaemia was observed with sitagliptin compared with sulfonylurea (6.2% vs. 27.8%; p < 0.001). Body weight decreased significantly with sitagliptin but not with sulfonylurea. Significantly more patients on sitagliptin than on sulfonylureas achieved a composite end-point of >0.5% HbA1c reduction with no reported hypoglycaemia or increase in body weight (44.1% vs. 16.0%; p < 0.001). CONCLUSION: In this analysis of elderly patients with T2DM, compared with sulfonylurea, sitagliptin provided similar glycaemic efficacy with less hypoglycaemia and with body weight loss.

Sitagliptin and pioglitazone provide complementary effects on postprandial glucose and pancreatic islet cell function.

AIMS: The effects of sitagliptin and pioglitazone, alone and in combination, on α- and ß-cell function were assessed in patients with type 2 diabetes. METHODS: Following a 6-week diet/exercise period, 211 patients with HbA1c of 6.5-9.0% and fasting plasma glucose of 7.2-14.4 mmol/l were randomized (1 :1 :1 : 1) to sitagliptin, pioglitazone, sitagliptin + pioglitazone or placebo. At baseline and after 12 weeks, patients were given a mixed meal followed by frequent blood sampling for measurements of glucose, insulin, C-peptide and glucagon. RESULTS: After 12 weeks, 5-h glucose total area under the curve (AUC) decreased in all active treatments versus placebo; reduction with sitagliptin + pioglitazone was greater versus either monotherapy. The 5-h insulin total AUC increased with sitagliptin versus all other treatments and increased with sitagliptin + pioglitazone versus pioglitazone. The 3-h glucagon AUC decreased with sitagliptin versus placebo and decreased with sitagliptin + pioglitazone versus pioglitazone or placebo. Φ(s), a measure of dynamic ß-cell responsiveness to above-basal glucose concentrations, increased with either monotherapy versus placebo and increased with sitagliptin + pioglitazone versus either monotherapy. The insulin sensitivity index (ISI), a composite index of insulin sensitivity, improved with pioglitazone and sitagliptin + pioglitazone versus placebo. The disposition index, a measure of the relationship between ß-cell function and insulin sensitivity, improved with all active treatments versus placebo. CONCLUSIONS: Sitagliptin and pioglitazone enhanced ß-cell function (increasing postmeal Φ(s)), and sitagliptin improved α-cell function (decreasing postmeal glucagon) after 12 weeks in patients with type 2 diabetes. Through these complementary mechanisms of action, the combination of sitagliptin and pioglitazone reduced postmeal glucose more than either treatment alone.

Recent trends in the characteristics of patients prescribed sitagliptin and other oral antihyperglycaemic agents in a large U.S. claims database.

AIM: This study was designed to determine if differences in baseline characteristics of patients with type 2 diabetes mellitus (T2DM) being treated with sitagliptin vs. other oral antihyperglycaemic agents (OAHA) during the initial 2 years following sitagliptin's introduction in the U.S. continued during the second 2 years of sitagliptin availability. METHODS: Patients with T2DM and at least one new prescription for sitagliptin or another OAHA from Oct 2006 to April 2010 were identified in an insurance claims database. Multivariate logistic regression adjusting for age, gender, treatment type (monotherapy, dual or triple therapy), new or existing T2DM diagnosis, and comorbidities and diabetes complications in the prior 12 months was used to estimate odds ratios for sitagliptin vs. other OAHAs. RESULTS: During 2006-2007 or 2008-2010, new sitagliptin users were older and more likely to be male, have prior diagnosis of T2DM, or initiating combination therapy compared with new users of other OAHAs. Prevalence of comorbidities and complications was consistently higher for new sitagliptin users across most of the conditions assessed during both time periods. CONCLUSIONS: New sitagliptin users consistently tended to be older and have greater comorbidity/complication burden compared with new users of other OAHAs. These differences in baseline characteristics persisted up to 4 years postapproval. This observation has significant implications for observational studies using electronic medical record or insurance claims databases. Appropriate adjustment is needed to try to control for potential confounding and channelling bias resulting from this non-random prescribing pattern, and the limitations of such analyses acknowledged.

Risk of acute renal failure in patients with Type 2 diabetes mellitus.

AIMS: Progressive decline in renal function has been well described in patients with Type 2 diabetes mellitus, but few studies have assessed the risk of acute renal failure in a large population of patients with Type 2 diabetes. This study quantified the risk of acute renal failure associated with Type 2 diabetes in the General Practice Research Database from the UK. METHODS: Patients with Type 2 diabetes (n = 119,966) and patients without diabetes (n = 1,794,516) were identified in the General Practice Research Database. Patients with end-stage renal disease were excluded. Crude incidence and multivariate-adjusted hazard ratios of acute renal failure were estimated for patients with diabetes relative to those without diabetes. Cox regression models were adjusted for a variety of comorbidities. Increase of acute renal failure risk resulting from additive effects of specific co-morbidities with Type 2 diabetes was also assessed. RESULTS: Between 2003 and 2007, acute renal failure incidence was 198 per 100,000 person-years in patients with Type 2 diabetes compared with 27 per 100,000 patients-years among patients without diabetes (crude hazard ratio 8.0, 95% CI 7.4-8.7). Risk of acute renal failure for patients with Type 2 diabetes remained significant, but was attenuated in multivariate analyses adjusting for various comorbidities (adjusted hazard ratio 2.5, 95% CI 2.2-2.7). Age and specific comorbidities (chronic kidney disease, hypertension and congestive heart failure) were also associated with increased risk of acute renal failure in Type 2 diabetes. CONCLUSIONS: Patients with Type 2 diabetes have increased risk for acute renal failure compared with patients without diabetes, even after adjustment for known risk factors, particularly in the elderly and those with other comorbidities such as chronic kidney disease, congestive heart failure and hypertension.

Impact of diabetes duration and chronic pancreatitis on the association between type 2 diabetes and pancreatic cancer risk.

AIM: To examine the impact of diabetes duration, chronic pancreatitis and other factors on pancreatic cancer risk. METHODS: This retrospective cohort study using the UK General Practice Research Database compared pancreatic cancer incidence and risk in patients with type 2 diabetes mellitus (T2DM) versus patients without diabetes. Multivariate Cox regression adjusting for age, sex, history of chronic pancreatitis, gallbladder disease, obesity, smoking and alcohol use and Charlson comorbidity index was used to estimate hazard ratio (HR) [95% confidence interval, CI]. Analyses were repeated using various time windows for diabetes duration. RESULTS: A total of 1903 incident pancreatic cancers were identified, 436 in patients with T2DM (78.76 per 100 000 person-years [95% CI: 71.54, 86.51]) and 1467 in patients without diabetes (11.46 per 100 000 person-years [10.88, 12.06]). Pancreatic cancer risk was significant for T2DM (adjusted HR 1.80 [1.52, 2.14]), increasing age, history of chronic pancreatitis and tobacco use. For patients with chronic pancreatitis and T2DM, the adjusted HR was 12.12 [6.02, 24.40]. Incidence was highest in patients with ≥5 year duration of T2DM. In patient populations with duration of T2DM ranging from ≥1 to ≥5 years, adjusted HRs remained significant but point estimates attenuated slightly with longer duration of T2DM. CONCLUSIONS: Patients with T2DM had an 80% increased risk of pancreatic cancer versus patients without diabetes. Patients with T2DM and chronic pancreatitis were 12 times more likely to develop pancreatic cancer.

Efficacy and safety of initial combination therapy with sitagliptin and pioglitazone in patients with type 2 diabetes: a 54-week study.

AIM: To assess the 54-week efficacy of initial combination therapy with sitagliptin and pioglitazone, compared with pioglitazone monotherapy, and to assess safety in these groups during the 30 weeks after the dosage of pioglitazone was increased from 30 to 45 mg/day, in drug-naÏve patients with type 2 diabetes mellitus and inadequate glycaemic control [haemoglobin A1c (HbA1c) 8-12%]. METHODS: Following a 24-week, randomized, double-blind, parallel-group study (Sitagliptin Protocol 064, Clinicaltrials.gov: NCT00397631; Yoon KH, Shockey GR, Teng R et al. Effect of initial combination therapy with sitagliptin, a dipeptidyl peptidase-4 inhibitor, and pioglitazone on glycaemic control and measures of beta-cell function in patients with type 2 diabetes. Int J Clin Pract 2011; 65: 154-164) in which patients were treated with the combination of sitagliptin 100 mg/day and pioglitazone 30 mg/day or monotherapy with pioglitazone 30 mg/day, patients entered a 30-week extension study. In the extension study, the pioglitazone dose was increased from 30 to 45 mg/day in both groups. Depending upon treatment allocation, patients took one tablet of sitagliptin 100 mg or matching placebo daily. Pioglitazone was administered in an open-label fashion as a single 45-mg tablet taken once daily. Patients not meeting specific glycaemic goals in the extension study were rescued with metformin therapy. Efficacy and safety results for the extension study excluded data after initiation of rescue therapy. RESULTS: Of the 520 patients initially randomized, 446 completed the base study and, of these, 317 entered the extension. In this extension study cohort, the mean reductions from baseline in HbA1c and fasting plasma glucose (FPG) at the end of the base study (week 24) were -2.5% and -62.1 mg/dl with the combination of sitagliptin 100 mg and pioglitazone 30 mg versus -1.9% and -48.7 mg/dl with pioglitazone monotherapy. At the end of the extension study (week 54), the mean reduction in haemoglobin A1c (HbA1c) was -2.4% with the combination of sitagliptin 100 mg and pioglitazone 45 mg versus -1.9% with pioglitazone monotherapy [between-group difference (95% CI) = -0.5% (-0.8, -0.3)] and the mean reduction in FPG was -61.3 mg/dl versus -52.8 mg/dl, respectively [between-group difference (95% CI) = -8.5 mg/dl (-16.3, -0.7)]. Safety and tolerability of initial treatment with the combination of sitagliptin and pioglitazone and pioglitazone monotherapy were similar. As expected, increases in body weight from baseline were observed in both treatment groups at week 54: 4.8 and 4.1 kg in the combination and monotherapy groups, respectively [between-group difference (95% CI) = 0.7 kg (-0.7, 2.1)]. CONCLUSION: In this study, initial combination therapy with sitagliptin 100 mg and pioglitazone 30 mg increased to 45 mg after 24 weeks led to a substantial and durable incremental improvement in glycaemic control compared with initial treatment with pioglitazone monotherapy during a 54-week treatment period. Both initial combination therapy with sitagliptin and pioglitazone and pioglitazone monotherapy were generally well tolerated (Clinicaltrials.gov: NCT01028391).

Initial therapy with the fixed-dose combination of sitagliptin and metformin results in greater improvement in glycaemic control compared with pioglitazone monotherapy in patients with type 2 diabetes.

AIMS: To evaluate the efficacy and safety of initial therapy with a fixed-dose combination (FDC) of sitagliptin and metformin compared with pioglitazone in drug-naÏve patients with type 2 diabetes. METHODS: After a 2-week single-blind placebo run-in period, patients with type 2 diabetes, HbA1c of 7.5-12% and not on antihyperglycaemic agent therapy were randomized in a double-blind manner to initial treatment with a FDC of sitagliptin/metformin 50/500 mg twice daily (N = 261) or pioglitazone 30 mg per day (N = 256). Sitagliptin/metformin and pioglitazone were up-titrated over 4 weeks to doses of 50/1000 mg twice daily and 45 mg per day, respectively. Both treatments were then continued for an additional 28 weeks. RESULTS: From a mean baseline HbA1c of 8.9% in both groups, least squares (LS) mean changes in HbA1c at week 32 were -1.9 and -1.4% for sitagliptin/metformin and pioglitazone, respectively (between-group difference = -0.5%; p < 0.001). A greater proportion of patients had an HbA1c of <7% at week 32 with sitagliptin/metformin vs. pioglitazone (57% vs. 43%, p < 0.001). Compared with pioglitazone, sitagliptin/metformin treatment resulted in greater LS mean reductions in fasting plasma glucose (FPG) [-56.0 mg/dl (-3.11 mmol/l) vs. -44.0 mg/dl (-2.45 mmol/l), p < 0.001] and in 2-h post-meal glucose [-102.2 mg/dl (-5.68 mmol/l) vs. -82.0 mg/dl (-4.56 mmol/l), p < 0.001] at week 32. A substantially greater reduction in FPG [-40.5 mg/dl (-2.25 mmol/l) vs. -13.0 mg/dl (-0.72 mmol/l), p < 0.001] was observed at week 1 with sitagliptin/metformin vs. pioglitazone. A greater reduction in the fasting proinsulin/insulin ratio and a greater increase in homeostasis model assessment of ß-cell function (HOMA-ß) were observed with sitagliptin/metformin than with pioglitazone, while greater decreases in fasting insulin and HOMA of insulin resistance (HOMA-IR), and a greater increase in quantitative insulin sensitivity check index (QUICKI) were observed with pioglitazone than with sitagliptin/metformin. Both sitagliptin/metformin and pioglitazone were generally well tolerated. Sitagliptin/metformin led to weight loss (-1.4 kg), while pioglitazone led to weight gain (3.0 kg) (p < 0.001 for the between-group difference). Higher incidences of diarrhoea (15.3% vs. 4.3%, p < 0.001), nausea (4.6% vs. 1.2%, p = 0.02) and vomiting (1.9% vs. 0.0%, p = 0.026), and a lower incidence of oedema (1.1% vs. 7.0%, p < 0.001), were observed with sitagliptin/metformin vs. pioglitazone. The between-group difference in the incidence of hypoglycaemia did not reach statistical significance (8.4 and 4.3% with sitagliptin/metformin and pioglitazone, respectively; p = 0.055). CONCLUSION: Compared with pioglitazone, initial therapy with a FDC of sitagliptin and metformin led to significantly greater improvement in glycaemic control as well as a higher incidence of prespecified gastrointestinal adverse events, a lower incidence of oedema and weight loss vs. weight gain.

Effects of climate and environmental variance on the performance of a novel peatland-based integrated multi-trophic aquaculture (IMTA) system: Implications and opportunities for advancing research and disruptive innovation post COVID-19 era.

Advancing wet peatland 'paludiculture' innovation present enormous potential to sustain carbon-cycles, reduce greenhouse-gas (GHG) gas emissions and to transition communities to low-carbon economies; however, there is limited scientific-evidence to support and enable direct commercial viability of eco-friendly products and services. This timely study reports on a novel, paludiculture-based, integrated-multi-trophic-aquaculture (IMTA) system for sustainable food production in the Irish midlands. This freshwater IMTA process relies on a naturally occurring ecosystem of microalgae, bacteria and duckweed in ponds for managing waste and water quality that is powered by wind turbines; however, as it is recirculating, it does not rely upon end-of-pipe solutions and does not discharge effluent to receiving waters. This constitutes the first report on the effects of extreme weather events on the performance of this IMTA system that produces European perch (Perca fluviatilis), rainbow trout (Oncorhynchus mykiis) during Spring 2020. Sampling coincided with lockdown periods of worker mobility restriction due to COVID-19 pandemic. Observations revealed that the frequency and intensity of storms generated high levels of rainfall that disrupted the algal and bacterial ecosystem in the IMTA leading to the emergence and predominance of toxic cyanobacteria that caused fish mortality. There is a pressing need for international agreement on standardized set of environmental indicators to advance paludiculture innovation that addresses climate-change and sustainability. This study describes important technical parameters for advancing freshwater aquaculture (IMTA), which can be future refined using real-time monitoring-tools at farm level to inform management decision-making based on evaluating environmental indicators and weather data. The relevance of these findings to informing global sustaining and disruptive research and innovation in paludiculture is presented, along with alignment with UN Sustainable Development goals. This study also addresses global challenges and opportunities highlighting a commensurate need for international agreement on resilient indicators encompassing linked ecological, societal, cultural, economic and cultural domains.

Efficacy and safety of treatment with sitagliptin or glimepiride in patients with type 2 diabetes inadequately controlled on metformin monotherapy: a randomized, double-blind, non-inferiority trial.

AIM: to evaluate the efficacy and safety of adding sitagliptin or glimepiride to the treatment regimen of patients with type 2 diabetes mellitus and inadequate glycaemic control on metformin monotherapy. METHODS: patients with type 2 diabetes and an HbA(1c) of 6.5-9.0% while on a stable dose of metformin (≥ 1500 mg/day) combined with diet and exercise for at least 12 weeks were randomized in a double-blind manner to receive either sitagliptin 100 mg daily (N = 516) or glimepiride (starting dose 1 mg/day and up-titrated, based upon patient's self-monitoring of blood glucose results, to a maximum dose of up to 6 mg/day) (N = 519) for 30 weeks. The primary analysis assessed whether sitagliptin is non-inferior to glimepiride in reducing HbA(1c) at week 30 (based on the criterion of having an upper bound of the 95% CI less than the prespecified non-inferiority bound of 0.4%). RESULTS: the mean baseline HbA(1c) was 7.5% in both the sitagliptin group (n = 443) and the glimepiride group (n = 436). After 30 weeks, the least squares (LS) mean change in HbA(1c) from baseline was -0.47% with sitagliptin and -0.54% with glimepiride, with a between-group difference (95% CI) of 0.07% (-0.03, 0.16). This result met the prespecified criterion for declaring non-inferiority. The percentages of patients with an HbA(1c) < 7.0% at week 30 were 52 and 60% in the sitagliptin and glimepiride groups, respectively. The LS mean change in fasting plasma glucose from baseline (95% CI) was -0.8 mmol/l (-1.0, -0.6) with sitagliptin and -1.0 mmol/l (-1.2, -0.8) with glimepiride, for a between-group difference (95% CI) of 0.2 mmol/l (-0.1, 0.4). The percentages of patients for whom hypoglycaemia was reported were 7% in the sitagliptin group and 22% in the glimepiride group (percentage-point difference = -15, p < 0.001). Relative to baseline, sitagliptin was associated with a mean weight loss (-0.8 kg), whereas glimepiride was associated with a mean weight gain (1.2 kg), yielding a between-group difference of -2.0 kg (p < 0.001). CONCLUSIONS: in patients with type 2 diabetes and inadequate glycaemic control on metformin monotherapy, the addition of sitagliptin or glimepiride led to similar improvement in glycaemic control after 30 weeks. Sitagliptin was generally well tolerated. Compared to treatment with glimepiride, treatment with sitagliptin was associated with a lower risk of hypoglycaemia and with weight loss versus weight gain (ClinicalTrials.gov: NCT00701090).

T cell responses in calcineurin A alpha-deficient mice.

We have created embryonic stem (ES) cells and mice lacking the predominant isoform (alpha) of the calcineurin A subunit (CNA alpha) to study the role of this serine/threonine phosphatase in the immune system. T and B cell maturation appeared to be normal in CNA alpha -/- mice. CNA alpha -/- T cells responded normally to mitogenic stimulation (i.e., PMA plus ionomycin, concanavalin A, and anti-CD3 epsilon antibody). However, CNA alpha -/- mice generated defective antigen-specific T cell responses in vivo. Mice produced from CNA alpha -/- ES cells injected into RAG-2-deficient blastocysts had a similar defective T cell response, indicating that CNA alpha is required for T cell function per se, rather than for an activity of other cell types involved in the immune response. CNA alpha -/- T cells remained sensitive to both cyclosporin A and FK506, suggesting that CNA beta or another CNA-like molecule can mediate the action of these immunosuppressive drugs. CNA alpha -/- mice provide an animal model for dissecting the physiologic functions of calcineurin as well as the effects of FK506 and CsA.

Patients with type 2 diabetes mellitus have higher risk for acute pancreatitis compared with those without diabetes.

AIM: The aetiology of acute pancreatitis (AP) is complex, and many risk factors for AP are shared by patients with type 2 diabetes mellitus (T2DM). However, few have assessed risk factors for AP specifically in T2DM patients. METHODS: Patients in the General Practice Research Database (2 984 755, 5.0% with T2DM) were used to estimate incidence of AP for T2DM relative to non-diabetes, adjusting for prior pancreatitis, gallbladder disease, obesity, smoking and alcohol use. Multivariate Cox regression analysis adjusting for risk factors and Charlson comorbidity index (CCI) was used to estimate hazard ratios (HR) with 95% confidence intervals (CI). RESULTS: Between 2003 and 2007, 301 of 148 903 patients with T2DM and 2434 of almost 3 million patients without diabetes developed AP. Patients with T2DM had higher risk for AP compared with patients without diabetes (crude HR: 2.89, 95% CI: 2.56-3.27). Patients with T2DM had significantly higher rates of prior alcohol and tobacco exposure (44.2 and 61.9% vs. 34.1 and 35.9%, p < 0.001) and of comorbid conditions (14.7% with CCI > or =1 vs. 4.3%, p < 0.001). Histories of obesity, pancreatitis, gallbladder disease, smoking or alcohol use were significant predictors of AP. After adjusting for these factors, age, gender and comorbidities, the risk of developing AP remained elevated in patients with T2DM (adjusted HR: 1.49, 95% CI: 1.31-1.70). CONCLUSION: After adjusting for risk factors, patients with T2DM had an elevated risk of AP compared with patients without diabetes. Physicians should be aware of the increased risk in patients with T2DM, particularly in those with prior pancreatitis.

Transcription factor OTF-1 is functionally identical to the DNA replication factor NF-III.

Octamer transcription factor-1 (OTF-1) and nuclear factor III (NF-III) are sequence-specific DNA binding proteins that activate transcription and DNA replication, respectively. It is shown here that OTF-1 is physically and biologically indistinguishable from NF-III. This conclusion is based on the following observations. First, the two proteins have identical mobilities by SDS-polyacrylamide gel electrophoresis. Second, OTF-1 binds to the adenovirus origin of DNA replication at the same site and with the same affinity as NF-III. Third, OTF-1 can substitute for NF-III in activating the initiation of adenovirus DNA replication in vitro. Fourth, the ability of OTF-1 to stimulate viral DNA replication is dependent on the presence of an intact NF-III binding site within the origin of replication. Fifth, NF-III can substitute for OTF-1 in activating in vitro transcription from the human histone H2b promoter. These data suggest the possibility that NF-III/OTF-1 is a protein that functions in both cellular DNA replication and transcription.

Sequence-specific interactions between cellular DNA-binding proteins and the adenovirus origin of DNA replication.

The adenovirus origin of DNA replication contains three functionally distinct sequence domains (A, B, and C) that are essential for initiation of DNA synthesis. Previous studies have shown that domain B contains the recognition site for nuclear factor I (NF-I), a cellular protein that is required for optimal initiation. In the studies reported here, we used highly purified NF-I, prepared by DNA recognition site affinity chromatography (P. J. Rosenfeld and T. J. Kelly, Jr., J. Biol. Chem. 261:1398-1408, 1986), to investigate the cellular protein requirements for initiation of viral DNA replication. Our data demonstrate that while NF-I is essential for efficient initiation in vitro, other cellular factors are required as well. A fraction derived from HeLa cell nuclear extract (BR-FT fraction) was shown to contain all the additional cellular proteins required for the complete reconstitution of the initiation reaction. Analysis of this complementing fraction by a gel electrophoresis DNA-binding assay revealed the presence of two site-specific DNA-binding proteins, ORP-A and ORP-C, that recognized sequences in domains A and C, respectively, of the viral origin. Both proteins were purified by DNA recognition site affinity chromatography, and the boundaries of their binding sites were defined by DNase I footprint analysis. Additional characterization of the recognition sequences of ORP-A, NF-I, and ORP-C was accomplished by determining the affinity of the proteins for viral origins containing deletion and base substitution mutations. ORP-C recognized a sequence between nucleotides 41 and 51 of the adenovirus genome, and analysis of mutant origins indicated that efficient initiation of replication is dependent on the presence of a high-affinity ORP-C-binding site. The ORP-A recognition site was localized to the first 12 base pairs of the viral genome within the minimal origin of replication. These data provide evidence that the initiation of adenovirus DNA replication involves multiple protein-DNA interactions at the origin.

Activity of Plasmid Replicons in CAULOBACTER CRESCENTUS : Rp4 and Cole1.

The RP4 replicon was detected as covalently-closed circular DNA in Caulobacter crescentus strains into which it had been transferred from Escherichia coli. RP4-mediated transfer of ColE1-associated markers into C. crescentus occurred, but only as the result of transposon-mediated events. Both transposition of a ColE1-associated marker onto RP4 and cointegration of ColE1 with RP4 were observed. Chimeric plasmids containing both a ColE1 and an RP4 origin of replication were stably maintained in C. crescentus , but similar plasmids lacking the RP4 origin of replication were not stably maintained in C. crescentus. Thus we show that the ColE1 replicon cannot be maintained in C. crescentus unless it is covalently linked to another replicon, such as RK2, that can be maintained.

Long-term efficacy of sitagliptin as either monotherapy or add-on therapy to metformin: improvement in glycemic control over 2 years in patients with type 2 diabetes.

OBJECTIVE: To evaluate the efficacy of once daily sitagliptin 100 mg as monotherapy or as add-on to metformin in patients with type 2 diabetes mellitus (T2DM) over 2 years of treatment. RESEARCH DESIGN AND METHODS: The monotherapy analysis used pooled 104 week data from 64 patients in two randomized, double-blind trials evaluating the safety and efficacy of sitagliptin monotherapy. Data used were from patients who were randomized to sitagliptin 100 mg/day, were not on an antihyperglycemic agent at the screening visit, had baseline A1C of 7.0%-10.0%, and had Week 104 A1C measurements. The add-on to metformin analysis used pooled data from 347 patients in two randomized double-blind trials evaluating the safety and efficacy of sitagliptin + metformin combination therapy. Data used were from patients who were randomized to sitagliptin 100 mg/day + metformin ≥1500 mg/day, had baseline A1C of 7%-10%, and had Week 104 A1C measurements. Excluded from either analysis were patients who discontinued prior to 2 years (e.g., due to lack of efficacy, a need for rescue medications, or adverse experiences). Analysis endpoints were A1C, fasting plasma glucose (FPG), HOMA-ß, proinsulin/insulin (P/I) ratio, and for monotherapy, 2 hour post-meal plasma glucose (PMG). RESULTS: For the pooled monotherapy cohort, after 2 years of treatment, mean A1C, FPG, and 2 hour PMG decreased from baseline values of 7.9%, 156 mg/dL, and 223 mg/dL to 6.9%, 143 mg/dL, and 191 mg/dL, respectively, while HOMA-ß increased from 67% to 85% and P/I ratio improved from 0.57 to 0.28. For the pooled add-on to metformin cohort, after 2 years of treatment, mean A1C and FPG decreased from baseline values of 7.7% and 160 mg/dL to 6.9% and 140 mg/dL, respectively, while HOMA-ß increased from 50% to 62% and P/I ratio improved from 0.33 to 0.28. These analyses are limited in that only patients who were able to complete 104 weeks of study were included. CONCLUSION: In the subset of patients with T2DM who maintained and completed treatment for 2 years with sitagliptin as monotherapy or as add-on to metformin, improvements in glycemic control and measures of ß-cell function were observed over the course of treatment.

Unusual sites of metastases.

Unusual metastases occur in a significant percentage of patients with malignant disease. In large measure, they represent a preterminal event. This is not always the case, however. In patients who have metastases to the skin, the event is generally preterminal particularly when the primary is the lung. In that instance the time between appearance of the metastasis and death is between 1.5 and 2.6 mo. Metastases to the skin occurring in patients with carcinoma of the cervix also represents a preterminal event with a time from diagnosis to death of 3 mo. In patients with carcinoma of the esophagus, the time from diagnosis to death is 4.3 mo, on the average. On the other hand, metastases to the skin from primary malignant tumors involving the colon, bladder, kidney, and ovary do not represent preterminal events. The time form diagnosis to death varies from 7.3 mo in carcinoma of the ovary to 12.7 mo in carcinomas of the kidney. Therefore, it is important when a patient presents with metastases to the skin to establish the primary source, the extent of the metastatic lesions and devise treatment programs that are appropriate to the pattern of the metastasis and the primary diagnosis...

Design and synthesis of potent, selective, and orally bioavailable tetrasubstituted imidazole inhibitors of p38 mitogen-activated protein kinase.

Novel potent and selective diarylimidazole inhibitors of p38 MAP (mitogen-activated protein) kinase are described which have activity in both cell-based assays of tumor necrosis factor-alpha (TNF-alpha) release and an animal model of rheumatoid arthritis. The SAR leading to the development of selectivity against c-Raf and JNK2alpha1 kinases is presented, with key features being substitution of the 4-aryl ring with m-trifluoromethyl and substitution of the 5-heteroaryl ring with a 2-amino substituent. Cell-based activity was significantly enhanced by incorporation of a 4-piperidinyl moiety at the 2-position of the imidazole which also enhanced aqueous solubility. In general, oral bioavailability of this class of compounds was found to be poor unless the imidazole was methylated on nitrogen. This work led to identification of 48, a potent (p38 MAP kinase inhibition IC50 0.24 nM) and selective p38 MAP kinase inhibitor which inhibits lipopolysaccharide-stimulated release of TNF-alpha from human blood with an IC50 2.2 nM, shows good oral bioavailability in rat and rhesus monkey, and demonstrates significant improvement in measures of disease progression in a rat adjuvant-induced arthritis model.

Periodic synthesis of phospholipids during the Caulobacter crescentus cell cycle.

Net phospholipid synthesis is discontinuous during the Caulobacter crescentus cell cycle with synthesis restricted to two discrete periods. The first period of net phospholipid synthesis begins in the swarmer cell shortly after cell division and ends at about the time when DNA replication initiates. The second period of phospholipid synthesis begins at a time when DNA replication is about two-thirds complete and ends at about the same time that DNA replication terminates. Thus, considerable DNA replication, growth, and differentiation (stalk growth) occur in the absence of net phospholipid synthesis. In fact, when net phospholipid synthesis was inhibited by the antibiotic cerulenin through the entire cell cycle, both the initiation and the elongation phases of DNA synthesis occurred normally. An analysis of the kinetics of incorporation of radioactive phosphate into macromolecules showed that the periodicity of phospholipid synthesis could not have been detected by pulse-labeling techniques, and only an analysis of cells prelabeled to equilibrium allowed detection of the periodicity. Equilibrium-labeled cells also allowed determination of the absolute amount of phosphorus-containing macromolecules in newborn swarmer cells. These cells contain about as much DNA as one Escherichia coli chromosome and about four times as much RNA as DNA. The amount of phosphorus in phospholipids is about one-seventh of that in DNA, or about 3% of the total macromolecular phosphorus.