Treatment with incretins does not increase the risk of pancreatic diseases compared to older anti-hyperglycaemic drugs, when added to metformin: real world evidence in people with Type 2 diabetes.

AIMS: In people with metformin-treated diabetes, to evaluate the risk of acute pancreatitis, pancreatic cancer and other diseases of the pancreas post second-line anti-hyperglycaemic agent initiation. METHODS: People with Type 2 diabetes diagnosed after 2004 who received metformin plus a dipeptidyl peptidase-4 inhibitor (DPP-4i, n = 50 095), glucagon-like peptide-1 receptor agonist (GLP-1RA, n = 12 654), sulfonylurea (n = 110 747), thiazolidinedione (n = 17 597) or insulin (n = 34 805) for at least 3 months were identified in the US Centricity Electronic Medical Records. Time to developing acute pancreatitis, other diseases of the pancreas and pancreatic cancer was estimated, balancing and adjusting anti-hyperglycaemic drug groups for appropriate confounders. RESULTS: In the DPP-4i group, the adjusted mean time to acute pancreatitis was 2.63 [95% confidence intervals (CI) 2.38, 2.88] years; time to pancreatic cancer was 2.70 (2.19, 3.21) years; and time to other diseases of the pancreas was 2.73 (2.33, 3.12) years. Compared with DPP-4i, the insulin group developed acute pancreatitis 0.48 years (P < 0.01) earlier and the GLP-1RA group developed pancreatic cancer 3 years later (P < 0.01). However, with the constraint of no event within 6 months of insulin initiation, the risk of acute pancreatitis in the insulin group was insignificant. No other significant differences were observed between groups. CONCLUSIONS: No significant differences in the risk of developing pancreatic diseases in those treated with various anti-hyperglycaemic drug classes were found.

Current cardiovascular outcomes trials in type 2 diabetes: Perspectives and insight.

AIMS: The increased risk of cardiovascular disease in patients with type 2 diabetes has been known for many years. However, until recently the cardiovascular (CV) impact of glucose lowering strategies has been inadequately understood. Major clinical trials have now investigated the impact of intensification of glycemic control upon CV outcomes, as well as the CV effects of glucose management with newer antihyperglycemic agents. DATA SYNTHESIS: Key findings from recently completed CV outcomes trials of dipeptidyl peptidase-4 (DPP4) inhibitors, GLP-1 receptor agonists, and sodium-glucose cotransporter 2 (SGLT2) inhibitors completed thus far are reviewed and summarized. CONCLUSIONS: Multiple trials designed to meet regulatory requirements for CV safety of antihyperglycemic medications have been initiated. The results of several completed CV outcomes trials clarify the risks and benefits associated with newer medications used to manage hyperglycemia in patients with type 2 diabetes, particularly in individuals at high CV risk. Important differences have been noted with respect to heart failure outcomes within the DPP4 inhibitor class, and thus far one agent in the SGLT2 inhibitor class has been found to significantly reduce rates of important CV outcomes. Robust safety related information from trials designed to assess the CV effects of diabetes therapies will permit the incorporation of outcomes-based evidence into the formulation of diabetes care guidelines.

Regional, age and sex differences in baseline characteristics of patients enrolled in the Trial Evaluating Cardiovascular Outcomes with Sitagliptin (TECOS).

AIMS: To report baseline characteristics and cardiovascular (CV) risk management by region, age, sex and CV event type for 14 724 participants in the Trial Evaluating Cardiovascular Outcomes with Sitagliptin (TECOS), a randomized, double-blind, placebo-controlled trial exploring whether sitagliptin added to usual type 2 diabetes (T2DM) care affects time to first event in the composite endpoint of CV death, non-fatal myocardial infarction (MI), non-fatal stroke or unstable angina hospitalization. METHODS: TECOS enrolled patients aged ≥50 years, with T2DM and CV disease from 38 countries in five regions: North America, Eastern Europe, Western Europe, Asia Pacific and Latin America. Participants had a glycated haemoglobin concentration of 6.5-8.0% (48-64 mmol/mol) and were receiving oral and/or insulin-based antihyperglycaemic therapy. Analysis of variance or logistic regression was used to compare regional CV risk factors and treatments, referenced to North America. RESULTS: Patients had a mean [1 standard deviation (SD)] age of 66 (8) years, a median (interquartile range) diabetes duration of 9.4 (4.9, 15.3) years, and a mean (SD) body mass index 30.2 (5.7) kg/m² . Compared with North America, blood pressure and lipids were higher in all regions. Statin use was lowest in Latin America (68%) and Eastern Europe (70%) and aspirin use was lower compared with North America in all regions except Asia Pacific. Achievement of treatment targets did not differ by age group or insulin usage, but men and participants with previous MI were more likely than women or those with previous stroke or peripheral arterial disease to reach most treatment goals. CONCLUSION: The CV risk factors of participants in TECOS are reasonably controlled, but differences in CV risk management according to region, sex and history of disease exist. This diversity will enhance the generalizability of the trial results.

Are current clinical trials in diabetes addressing important issues in diabetes care?

AIMS/HYPOTHESIS: Clinical trials assessing interventions for treating and preventing diabetes mellitus and its complications are needed to inform evidence-based practice. To examine whether current studies adequately address these needs, we conducted a descriptive analysis of diabetes-related trials registered with ClinicalTrials.gov from 2007 to 2010. METHODS: From a dataset including 96,346 studies registered in ClinicalTrials.gov downloaded on 27 September, 2010, a subset of 2,484 interventional trials was created by selecting trials with disease condition terms relevant to diabetes. RESULTS: Of the diabetes-related trials, 74.8% had a primarily therapeutic purpose while 10% were preventive. Listed interventions included drugs (63.1%) and behavioural (11.7%). Most trials were designed to enrol ≤ 500 (91.1%) or ≤ 100 (58.6%) participants, with mean/median times to completion of 1.8/1.4 years. Small percentages of trials targeted persons aged ≤ 18 years (3.7%) or ≥ 65 years (0.6%), while 30.8% excluded patients >65 years and the majority excluded those >75 years. Funding sources included industry (50.9%), NIH (7.5%) or other, with most being single-centre trials of other sponsorship (37.7%) or industry-funded multicentre studies (27.4%). A small number of trials (1.4%) listed primary outcomes including mortality or clinically significant cardiovascular complications. The distribution of trials by global region and US state does not correlate with prevalence of diabetes. CONCLUSIONS/INTERPRETATION: The majority of diabetes-related trials include small numbers of participants, exclude those at the extremes of age, are of short duration, involve drug therapy rather than preventive or non-drug interventions and do not focus upon significant cardiovascular outcomes. Recently registered diabetes trials may not sufficiently address important diabetes care issues or involve affected populations.

Optimizing outcomes of laser tattoo removal.

Since the elucidation of the concept of selective photothermolysis, quality-switched lasers have been the gold standard for tattoo removal. Proper patient education prior to commencing treatment is crucial to ensure realistic expectations and compliance. This article reviews appropriate device selection and technique. Clinical pearls and pitfalls are presented, as well as cutting-edge techniques and technologies are discussed in order to enable the laser practitioner to optimize outcomes.

Molar Bud-to-Cap Transition Is Proliferation Independent.

Tooth germs undergo a series of dynamic morphologic changes through bud, cap, and bell stages, in which odontogenic epithelium continuously extends into the underlying mesenchyme. During the transition from the bud stage to the cap stage, the base of the bud flattens and then bends into a cap shape whose edges are referred to as "cervical loops." Although genetic mechanisms for cap formation have been well described, little is understood about the morphogenetic mechanisms. Computer modeling and cell trajectory tracking have suggested that the epithelial bending is driven purely by differential cell proliferation and adhesion in different parts of the tooth germ. Here, we show that, unexpectedly, inhibition of cell proliferation did not prevent bud-to-cap morphogenesis. We quantified cell shapes and actin and myosin distributions in different parts of the tooth epithelium at the critical stages and found that these are consistent with basal relaxation in the forming cervical loops and basal constriction around enamel knot at the center of the cap. Inhibition of focal adhesion kinase, which is required for basal constriction in other systems, arrested the molar explant morphogenesis at the bud stage. Together, these results show that the bud-to-cap transition is largely proliferation independent, and we propose that it is driven by classic actomyosin-driven cell shape-dependent mechanisms. We discuss how these results can be reconciled with the previous models and data.

Immunohistochemical evaluation of toxic epidermal necrolysis treated with human intravenous immunoglobulin.

AIM: Toxic epidermal necrolysis (TEN) is a severe drug reaction characterized by massive epidermal cell death. The authors of the current study and others have noted improved outcomes in TEN patients treated with human intravenous immunoglobulin (IVIG), purportedly due to its ability to inhibit the fas/fas-ligand (Fas-L) apoptotic pathway, but published case series evaluating TEN through the use of immunohistochemical antibody stains for Fas and Fas-L before and after IVIG treatment are lacking. The authors hypothesized that due to IVIG's ability to arrest the evolution of TEN, expression of Fas/Fas-L on keratinocytes would be decreased or absent following IVIG treatment. METHODS: Ten patients diagnosed with TEN underwent biopsies of their lesions prior to and five days after treatment with IVIG. Seven post-treatment biopsies were of sufficient quality to undergo evaluation. RESULTS: All ten pretreatment biopsies had Fas and Fas-L expression by immunohistochemistry, while six out of seven (85.7%) post-treatment biopsies failed to demonstrate Fas or Fas-L expression. One of seven post-treatment biopsies stained positive for Fas and Fas-L. CONCLUSION: This reduced immunohistochemical expression of apoptotic markers may represent IVIG inhibition of the pathogenic mechanism of TEN. Alternatively reduced Fas and Fas-L may be a feature of reepithelialization in TEN, or characteristic of rapidly proliferating epidermis.

Growth factors as morphogens: do gradients and thresholds establish body plan?

Theories of morphogenesis have centred around gradients of morphogens interpreted by cells according to preset concentration thresholds. Growth factor proteins have been candidates for such morphogens, and experiments in the frog Xenopus, among other organisms, now show that embryonic cells are capable of interpreting growth factor concentrations according to the models. This opens up questions of whether such mechanisms are sufficient, and-if there are growth factor gradients-which factors are actually used and how.

RNA folding.

The number of known motifs for RNA folding and RNA tertiary organization is expanding rapidly as we learn more about the diverse biological functions of RNA. Problems in protein and RNA folding have melded in recent investigations of ribonucleoprotein folding. Theoretical and experimental models are rapidly being developed for the pathways and stabilizing forces involved in RNA folding.

Chemotherapy of drug-resistant ovarian cancer: a Southwest Oncology Group Study.

We present a final analysis, including pathology review, of a cooperative group study of drug-resistant ovarian cancer. Of 200 patients registered, 112 were eligible and evaluable, with a response rate of 26% and median survival of 7 months. Because these results are poorer than those reported in the preliminary and interim analyses of this study, we scrutinized the 88 excluded patients, most of whom failed to meet our strict pathologic criteria for a diagnosis of ovarian cancer of epithelial type, and who, as a heterogeneous group, fared better than patients who did meet the eligibility criteria. We believe this analysis provides insight into the spectrum of diseases that are frequently called ovarian cancer, but might be more properly labeled abdominal carcinomatosis.

Scanning probe microscopy.

During the past year, scanning probe microscopy, especially atomic force microscopy (AFM), has taken root in the biological sciences community, as is evident from the large number of publications and from the variety of specialized journals in which these papers appear. Furthermore, there is a strong indication that the technique is evolving from a qualitative imaging tool to a probe of the critical dimensions and properties of biomolecules and living cells. The next stage of the evolution involves the development of microinstruments for process control and sensing applications. Recent advances have been reported in AFM instrumentation and method. For example, the tapping mode of operation is becoming the method of choice to image biological molecules; work to extend tapping-mode operation in liquids has been reported. Biological molecules can also be imaged at low temperature in a cryo-AFM with improved resolution. The measurement of recognition forces between individual molecules continues to attract much attention and has spawned new concepts for ultra-sensitive biosensors. The AFM is being used increasingly for property measurements such as determining the viscoelastic properties of biological molecules. Finally, structural studies using the AFM abound. Some specific highlights include the mapping of DNA using restriction enzymes, imaging during DNA transcription and determining the mode of drug binding to DNA.

Branch-site selection in a group II intron mediated by active recognition of the adenine amino group and steric exclusion of non-adenine functionalities.

The 2'-hydroxyl on a specific bulged adenosine is the nucleophile during the first step of splicing by group II introns. To understand the means by which the ribozyme core recognizes this adenosine, it was mutagenized and effects on catalytic activity were quantified. The results indicate that a low level of mutational variability is tolerated at the branch-site of group II introns, with no apparent loss of fidelity. Analyses of mutant and modified nucleotides at the branch-site reveal that adenine is recognized primarily through the N6 amino group and by steric exclusion of functionalities found on other bases. The mutational and single atom effects reported here contrast with those observed during spliceosomal processing, suggesting that there are important differences in adenosine recognition by the two systems.

Differential effects on Xenopus development of interference with type IIA and type IIB activin receptors.

One candidate for a mesoderm-inducing factor in early amphibian development is activin, a member of the TGF beta family. Overexpression of a truncated form of an activin receptor Type IIB abolishes activin responsiveness and mesoderm formation in vivo. The Xenopus Type IIA activin receptor XSTK9 differs from the Type IIB receptor by 43 and 25% in extracellular and intracellular domains respectively, suggesting the possibility of different functions in vivo. In this paper, we compare the Type IIA receptor with the Type IIB to test such a possibility. Simple overexpression of the wild-type receptors reveals minimal differences, but experiments with dominant negative mutants of each receptor show qualitatively distinct effects. We show that while truncated (kinase domain-deleted) Type IIB receptors cause axial defects as previously described, truncated type IIA receptors cause formation of secondary axes, similar to those seen by overexpression of truncated receptors for BMP-4, another TGF beta family member. Furthermore, in animal cap assays, truncated type IIB receptors inhibit induction of all mesodermal markers tested, while truncated type IIA receptors suppress induction only of ventral markers; the anterior/dorsal marker goosecoid is virtually unaffected. The suppression of ventral development by the type IIA truncated receptor suggests either that the truncated Type IIA receptor interferes with ventral BMP pathways, or that activin signaling through the Type IIA receptor is necessary for ventral patterning.

Pyruvate decarboxylase is like acetolactate synthase (ILV2) and not like the pyruvate dehydrogenase E1 subunit.

Protein sequences of pyruvate decarboxylase (PDC) derived from cloned yeast (Saccharomyces cerevisiae) and bacterial (Zymomonas mobilis) genes were compared with each other and with sequence databases. Extensive sequence similarities were found between them and with two others: cytochrome-linked pyruvate oxidase from Escherichia coli and acetolactate synthase (ilvI in E. coli; ILV2 gene in S. cerevisiae). All catalyse decarboxylation of pyruvate using thiamine pyrophosphate (TPP) as cofactor. General overall similarity suggests common ancestry for these enzymes. None of the sequences was similar to the E1 component of pyruvate dehydrogenase from E. coli which also decarboxylates pyruvate with the help of TPP.

Multicompartmental analysis of the effects of dietary fat saturation and cholesterol on absorptive lipoprotein metabolism in the rat.

The potential contribution of the metabolism of absorptive lipoproteins to effects of dietary cholesterol and saturated (versus polyunsaturated) fat on plasma lipids and lipoproteins was studied in rats. Recipients were fed either a commercial stock diet, a low fat/cholesterol-free semipurified diet with a neutral P/S ratio, or one of two high fat/cholesterol-containing diets that had a high (4.6) or low (0.2) P/S ratio. Chylomicrons and intestinal very low-density lipoproteins labeled with 3H-oleic acid and/or 14C-cholesterol were isolated from donor rats receiving the high or low P/S ratio oil and were injected into recipients. Data on plasma disappearance and hepatic recovery of labels were analyzed by compartmental analysis. A multicompartmental model was required to fit these data and included steps interpreted to correspond to activation of newly secreted intestinal lipoproteins; delipidation on capillary endothelia by lipoprotein lipase, with transfer of cholesterol to other lipoproteins and tissue uptake of cholesterol and fatty acids; hepatic clearance of remnants; and secretion of lipoproteins by the liver. Metabolic state of the recipients (especially plasma triglyceride concentrations) had a greater influence on the rate of chylomicron turnover than did the source of donor chylomicrons, although saturated chylomicrons tended to be metabolized more slowly than polyunsaturated ones. For recipients fed the commercial stock diet and injected with saturated (versus polyunsaturated) chylomicrons, the mechanistic model predicted an increased retention of triglycerides during remnant formation, and thus an increased delivery of triglyceride to the liver. A consequent elevation in hepatic production of very low-density lipoprotein triglycerides may be related to the observed slower clearance of chylomicrons and increased plasma lipid levels in rats fed saturated fat and cholesterol.

Absorption of water-miscible forms of vitamin E in a patient with cholestasis and in thoracic duct-cannulated rats.

Oral administration of vitamin E (100 mg tocopherol X kg-1 X day-1) as tocopheryl polyethylene glycol 1000 succinate (TPGS) to a child with congenital hepatic cholestasis (unresponsive to oral administration of dl-alpha-tocopheryl acetate) promoted an increase of tocopherol in plasma and adipose tissue while tocopheryl acetate emulsified with medium chain triglycerides and polysorbate 80 (MCT-E) did not. alpha-Tocopherol absorption, quantitated in thoracic duct-cannulated rats receiving intraduodenal infusions of soybean oil and saline, was similar for TPGS, MCT-E, and dl-alpha-tocopheryl acetate; gamma-tocopherol absorption from soybean oil was not affected by the presence of the supplemental alpha-tocopherol. Following bile duct ligation in one rat, TPGS promoted the absorption of alpha-tocopherol while absorption of gamma-tocopherol from soybean oil was decreased 30 fold, demonstrating that TPGS, which forms a micellar solution, delivers alpha-tocopherol through the unstirred water layer to enterocytes, while free tocopherol (alpha or gamma) absorption requires the presence of bile salts.

Evoked potentials in multiple sclerosis.

Short-latency somatosensory short-latency auditory, and pattern evoked visual potentials were recorded in 115 patients with suspected, possible, probable, or clinically definite multiple sclerosis. An abnormality of at least one evoked potential was found in 94% of the clinically definite cases, in 67% of the summed suspected, possible, and probable cases, and in 80% of the entire series. Abnormalities of all three modalities of evoked potentials were correlated with severity of illness. Short-latency auditory evoked potential abnormalities were correlated with clinical judgement in respect to localization of lesions and activity of disease.

Short latency somatosensory evoked potentials in patients with neurological lesions.

Short latency somatosensory potentials following median nerve stimulation were recorded in patients grouped according to anatomic location of neurological lesion. Patients with cerebral lesions causing severe sensory deficit lacked a major positive wave of cortical origin that in normal subjects peaked at a mean latency of 20.5 ms. Patients with severe cervical spinal cord disease lacked all of the normal somatosensory response except for the earliest component attributed to peripheral nerve activity. Patients with brain-stem lesions showed delayed latencies of later waves and prolonged interwave latencies. However, auditory evoked potentials measured in the group with brain-stem lesions were more helpful in localization. Analysis of short latency somatosensory potentials can discriminate between peripheral nerve, spinal cord, brain-stem, and cerebral lesions. Further experience and refinement of technique of measurement should increase the value of this procedure.

Short-latency somatosensory evoked potentials in multiple sclerosis. Comparison with auditory and visual evoked potentials.

Short-latency somatosensory potentials after median nerve stimulation were recorded in 17 patients with clinically definite cases of multiple sclerosis and in 15 patients with probable, possible, or suspected cases. Abnormalities, usually prolongation of component wave latencies, were found in 20 patients, often with normal clinicaly sensory testing. Abnormalities in brief auditory evoked potentials were found less often but were significantly more frequent in the group with clinically definite cases. Pattern evoked visual potentials may have been more useful in identifying early cases. The recording of all three evoked potentials showed an abnormality of at least one in most patients.

Intrathoracic meningoceles and neurofibromatosis.

We describe here four additional cases of intrathoracic meningoceles associated with neurofibromatosis, bringing the total number of reported cases of thoracic meningoceles to 88. Seventy-five (85%) have been associated with neurofibromatosis. Possibly, both dural and regional vertebral dysplasia are intrinsic to neurofibromatosis and contribute to the development of the meningocele.