Human adenovirus in tissues of freshwater snails living in contaminated waters.

Human adenovirus (HAdV) is resistant to environment and can be used as a marker to detect fecal contamination. Considering the importance of freshwater snails in the aquatic environment, their use as concentrators for HAdV is a complementary tool for viral analysis of water. The goal of the study was to detect HAdV in snails and surface water collected from wetlands of the Sinos River (Rio Grande do Sul, Brazil) basin and to compare rates and viral loads found in both samples. HAdV was detected through real-time PCR. Total and fecal coliforms were detected by Colilert® kit, and viral infectivity of positive samples of the DNA genome was performed in A549 human cell line. All wetlands presented bacterial and viral contamination, but no viral particle was considered viable. The wetland that showed lower fecal coliform mean was Campo Bom, and São Leopoldo (both cities in Rio Grande do Sul) was representative of the highest mean. HAdV was detected in water samples (53%), gastropods' hemolymph (31%) and tissues (16%). Wetlands proved to be environments already altered by human action. Water samples exhibited a higher frequency of HAdV detection; however, in some instances, the target viral genomes were only found in gastropod biological samples. This was a pioneer study in the use of freshwater snails for human enteric viral assessment thus demonstrating that the human organism can retain fecal contamination, complementing and assisting in microbiological water analyzes.

Patient-level meta-analysis of the EDITION 1, 2 and 3 studies: glycaemic control and hypoglycaemia with new insulin glargine 300 U/ml versus glargine 100 U/ml in people with type 2 diabetes.

AIMS: To conduct a patient-level meta-analysis of the EDITION 1, 2 and 3 studies, which compared the efficacy and safety of new insulin glargine 300 U/ml (Gla-300) with insulin glargine 100 U/ml (Gla-100) in people with type 2 diabetes (T2DM) on basal and mealtime insulin, basal insulin and oral antihyperglycaemic drugs, or no prior insulin, respectively. METHODS: The EDITION studies were multicentre, randomized, open-label, parallel-group, phase IIIa studies, with similar designs and endpoints. A patient-level meta-analysis of the studies enabled these endpoints to be examined over 6 months in a large population with T2DM (Gla-300, n = 1247; Gla-100, n = 1249). RESULTS: No significant study-by-treatment interactions across studies were found, enabling them to be pooled. The mean change in glycated haemoglobin was comparable for Gla-300 and Gla-100 [each -1.02 (standard error 0.03)%; least squares (LS) mean difference 0.00 (95% confidence interval (CI) -0.08 to 0.07)%]. Annualized rates of confirmed (≤3.9 mmol/l) or severe hypoglycaemia were lower with Gla-300 than with Gla-100 during the night (31% difference in rate ratio over 6 months) and at any time (24 h, 14% difference). Consistent reductions were observed in percentage of participants with ≥1 hypoglycaemic event. Severe hypoglycaemia at any time (24 h) was rare (Gla-300: 2.3%; Gla-100: 2.6%). Weight gain was low (<1 kg) in both groups, with less gain with Gla-300 [LS mean difference -0.28 kg (95% CI -0.55 to -0.01); p = 0.039]. Both treatments were well tolerated, with similar rates of adverse events. CONCLUSION: Gla-300 provides comparable glycaemic control to Gla-100 in a large population with a broad clinical spectrum of T2DM, with consistently less hypoglycaemia at any time of day and less nocturnal hypoglycaemia.

Do current incretin mimetics exploit the full therapeutic potential inherent in GLP-1 receptor stimulation?

Glucagon-like peptide-1 (GLP-1) receptor agonists (RAs) are incretin-derived glucose-lowering agents that have been used for the treatment of type 2 diabetes since 2007. Agents such as exenatide (short-acting and once weekly preparations), liraglutide, taspoglutide, albiglutide and lixisenatide lower fasting glucose and HbA1c upon subcutaneous injection, leading to glycaemic control that is equivalent to, or better than, that observed with other oral glucose-lowering agents or bedtime insulin. However, varying proportions of patients report nausea and vomiting, adverse events that typically narrow the therapeutic dose range. Furthermore, GLP-1 RAs reduce fasting glucose to a clinically meaningful extent, but not into the normal range. In contrast, where GLP-1 is administered as a short-term intravenous infusion, a full normalisation of glucose concentrations (approximately 5 mmol/l) has been observed without any risk of gastrointestinal side effects. Subcutaneous infusions or injections of GLP-1 are much less effective. The present analysis relates the proportion of patients who report nausea following treatment with GLP-1 and GLP-1 RAs to the clinical effectiveness of the treatment (represented by the fasting glucose concentration achieved with treatment). The results suggest that GLP-1 RAs injected into the subcutaneous compartment do not exploit the full potential inherent in GLP-1 receptor activation. Reasons for this may include modifications of the peptide molecules in the subcutaneous environment or high local concentrations triggering side effects through GLP-1 receptors on autonomic nerves in subcutaneous adipose tissue. Elucidation of the mechanisms underlying differential responses to GLP-1/GLP-1 RAs administered intravenously vs subcutaneously may help to develop improved agents or modes of administration that are more effective and have fewer side effects.

Targeted mutation of the gene encoding prion protein in zebrafish reveals a conserved role in neuron excitability.

The function of the cellular prion protein (PrP(C)) in healthy brains remains poorly understood, in part because Prnp knockout mice are viable. On the other hand, transient knockdown of Prnp homologs in zebrafish (including two paralogs, prp1 and prp2) has suggested that PrP(C) is required for CNS development, cell adhesion, and neuroprotection. It has been argued that zebrafish Prp2 is most similar to mammalian PrP(C), yet it has remained intransigent to the most thorough confirmations of reagent specificity during knockdown. Thus we investigated the role of prp2 using targeted gene disruption via zinc finger nucleases. Prp2(-/-) zebrafish were viable and did not display overt developmental phenotypes. Back-crossing female prp2(-/-) fish ruled out a role for maternal mRNA contributions. Prp2(-/-) larvae were found to have increased seizure-like behavior following exposure to the convulsant pentylenetetrazol (PTZ), as compared to wild type fish. In situ recordings from intact hindbrains demonstrated that prp2 regulates closing of N-Methyl-d-aspartate (NMDA) receptors, concomitant with neuroprotection during glutamate excitotoxicity. Overall, the knockout of Prp2 function in zebrafish independently confirmed hypothesized roles for PrP, identifying deeply conserved functions in post-developmental regulation of neuron excitability that are consequential to the etiology of prion and Alzheimer diseases.

Glycaemic control and hypoglycaemia risk with insulin glargine 300 U/mL versus glargine 100 U/mL: A patient-level meta-analysis examining older and younger adults with type 2 diabetes.

AIM: Older people with type 2 diabetes (T2DM) are at an increased risk of hypoglycaemia and its consequences. However, efficacy and safety data for basal insulin therapy are limited in these individuals. This patient-level meta-analysis assessed the treatment effects of insulin glargine 300 U/mL (Gla-300) versus glargine 100 U/mL (Gla-100) in people with T2DM ≥ 65 years old. METHODS: Data were pooled for patients randomised to receive Gla-300 or Gla-100 in the Phase 3a, treat-to-target EDITION 1, 2 and 3 trials. Glycaemic efficacy, hypoglycaemia, changes in body weight and insulin dosage and adverse events were examined over 6 months' treatment with Gla-300 versus Gla-100 for participants aged ≥ 65 and < 65 years. RESULTS: Of 2496 participants randomised, 662 were ≥ 65 years (Gla-300, n = 329; Gla-100, n = 333). Glycaemic control was comparable for Gla-300 and Gla-100 in participants ≥ 65 years (LS mean [95% CI] difference in HbA1c change from baseline to month 6: 0.00 [-0.14 to 0.15] %; 0.00 [-1.53 to 1.64] mmol/mol) and < 65 years (0.00 [-0.09 to 0.08] %; 0.00 [-0.98 to 0.87] mmol/mol). Fewer participants receiving Gla-300 versus Gla-100 experienced nocturnal confirmed (≤ 3.9 mmol/L [≤ 70 mg/dL]) or severe hypoglycaemia (relative risk: ≥ 65 years: 0.70 [0.57 to 0.85]; < 65 years: 0.77 [0.68 to 0.87]). Annualised rates of nocturnal confirmed or severe hypoglycaemia were lower with Gla-300 than Gla-100 for both age groups. CONCLUSION: Gla-300 was associated with a reduced risk of nocturnal hypoglycaemia versus Gla-100, accompanied by comparable glycaemic improvement, for people aged ≥ 65 and < 65 years with T2DM.

[Invasive diagnostic procedures for insulinomas of the pancreas]. / Invasive Diagnostik bei Insulinomen des Pankreas.

Insulinomas are the most common cause for hypoglycemia with endogenous hyperinsulinism. Insulinomas are the most frequent endocrine tumor of the pancreas and 10% occur as multiple tumors (e.g. multiple endocrine neoplasia type I) or in rare cases as islet cell hyperplasia. A further 10-15% of insulinomas are malignant. Non-invasive imaging modalities, such as computed tomography (CT), magnetic resonance imaging (MRI), ultrasonography (US) and somatoreceptor scintigraphy (SRN) show a lower sensitivity for detection and localization of tumors, because in many cases insulinomas are smaller than 2 cm in size. Invasive pre-operative diagnostic procedures, such as transhepatic peripancreatic venous blood sampling (TPVB) and the intra-arterial calcium stimulation test (ASVS) are much more time-intensive compared to CT, MRI and US with an examination time of 2-3 h but achieve a more exact pre-operative detection and localization with sensitivities mostly greater than 95% and are therefore the diagnostic methods of choice.

Clinical perspectives from the BEGIN and EDITION programmes: Trial-level meta-analyses outcomes with either degludec or glargine 300U/mL vs glargine 100U/mL in T2DM.

AIMS: To explore comparative glycaemic control and hypoglycaemia incidence with insulin degludec 100U/mL (IDeg) or insulin glargine 300U/mL (Gla-300) versus glargine 100U/mL (Gla-100) in trial-level meta-analyses of phase 3a clinical trials including people with type-2 diabetes. METHODS: Meta-analyses of HbA1c, fasting plasma glucose (FPG), average 24h self-measured plasma glucose (SMPG), pre-breakfast SMPG and hypoglycaemia incidence and rate, using data from the BEGIN (IDeg) and EDITION (Gla-300) insulin development programmes, were performed. RESULTS: In BEGIN, despite greater FPG reduction with IDeg than Gla-100, HbA1c reduction was greater with Gla-100 (mean difference [95% CI] in HbA1c change: 0.09 [0.01-0.18] %) whereas in EDITION, there was no difference in FPG and HbA1c reduction between Gla-300 and Gla-100. Risk of nocturnal confirmed (<3.1mmol/L [<56mg/dL]) or severe hypoglycaemia, but not anytime (24h) events, was lower with IDeg than Gla-100 (relative risk [RR] 0.79 [0.66-0.94]) whereas Gla-300 was associated with reduced risk of nocturnal (RR 0.75 [0.61-0.92]) and anytime (24h) (RR 0.81 [0.69-0.94]) confirmed (<3.0mmol/L [<54mg/dL]) or severe hypoglycaemia versus Gla-100. CONCLUSIONS: These trial-level meta-analyses suggest that despite greater reductions in FPG, IDeg was associated with less improvement in HbA1c versus Gla-100, with a hypoglycaemia benefit only evident at night. In contrast, Gla-300 showed similar HbA1c reduction to Gla-100, accompanied by lower risk of hypoglycaemia both at night and at any time of day. Gla-300 and IDeg appear more similar than dissimilar, but head-to-head trials are required.

Role of the negative charges in the cytosolic domain of TOM22 in the import of precursor proteins into mitochondria.

TOM22 is an essential mitochondrial outer membrane protein required for the import of precursor proteins into the organelles. The amino-terminal 84 amino acids of TOM22 extend into the cytosol and include 19 negatively and 6 positively charged residues. This region of the protein is thought to interact with positively charged presequences on mitochondrial preproteins, presumably via electrostatic interactions. We constructed a series of mutant derivatives of TOM22 in which 2 to 15 of the negatively charged residues in the cytosolic domain were changed to their corresponding amido forms. The mutant constructs were transformed into a sheltered Neurospora crassa heterokaryon bearing a tom22::hygromycin R disruption in one nucleus. All constructs restored viability to the disruption-carrying nucleus and gave rise to homokaryotic strains containing mutant tom22 alleles. Isolated mitochondria from three representative mutant strains, including the mutant carrying 15 neutralized residues (strain 861), imported precursor proteins at efficiencies comparable to those for wild-type organelles. Precursor binding studies with mitochondrial outer membrane vesicles from several of the mutant strains, including strain 861, revealed only slight differences from binding to wild-type vesicles. Deletion mutants lacking portions of the negatively charged region of TOM22 can also restore viability to the disruption-containing nucleus, but mutants lacking the entire region cannot. Taken together, these data suggest that an abundance of negative charges in the cytosolic domain of TOM22 is not essential for the binding or import of mitochondrial precursor proteins; however, other features in the domain are required.

Autoantibodies in diabetes mellitus: current utility and perspectives.

Testing of autoantibodies in individuals at risk of developing or being newly diagnosed with diabetes mellitus is currently of very limited clinical value. However, clinical studies evaluating new therapeutic options for the delay or treatment of type 1 diabetes mellitus require sensitive, specific, and reliable assays for autoimmune antibodies associated with diabetes mellitus. With immune modulatory treatment of pre-diabetes mellitus on the horizon the need of reliable assays is evident. In addition, determination of autoimmune antibodies in diabetes mellitus facilitates studies investigating the pathophysiology underlying this disease. Clinicians and researchers should be aware of the tests available, their limitations, their clinical relevance, and their indications. This review focuses on the current knowledge about antibody assays for diabetes associated autoimmunity, their clinical value, their role in diagnosing and predicting autoimmune associated diabetes mellitus, and research applications.

Preserved GLP-1 effects in a diabetic patient with Cushing's disease.

CONTEXT: A patient with diabetes mellitus, who participated in a study with intravenous administration of GLP-1, was later found to have Cushing's disease (markedly elevated 24 h urinary cortisol excretion and inadequate suppression of fasting cortisol with 2 mg dexamethasone). His diabetic state disappeared (2 h plasma glucose after 75 g oral glucose 159 mg/dl=IGT) after successful pituitary surgery (normal 24 h urinary cortisol excretion and adequate cortisol suppression with 2 mg dexamethasone). OBJECTIVE: The present analysis was undertaken to compare GLP-1 actions on fasting glycemia in diabetes mellitus due to Cushing's disease with GLP-1 actions in typical type 2 diabetes. DESIGN AND METHODS: GLP-1 (1.2 pmol/kg/min) and placebo had been infused into ten patients with diabetes mellitus over 4 h in the fasting state. The results from the patient with Cushing's disease (C) were compared to the data from the remaining nine patients with type 2 diabetes (D). RESULTS: Within 4 h glucose decreased from basal (C: 12.9; D: 12.9+/-0.7 mmol/l) to normal fasting values (C: 5.0; D: 4.9+/-0.4 mmol/l). The stimulation of insulin secretion and suppression of glucagon secretion was similar in the patient with Cushing's disease compared to those with type 2 diabetes. CONCLUSIONS: The insulinotropic, glucagonostatic and glucose-lowering actions of GLP-1 in a patient with diabetes mellitus due to cortisol excess were similar to actions in typical type 2 diabetes. Therefore incretin mimetics might be a novel therapeutic strategy for the treatment of glucocorticoid-induced diabetes mellitus.

Expression of two insm1-like genes in the developing zebrafish nervous system.

Insulinoma associated-1 (INSM1, formerly IA-1) is a Cys(2)-His(2) zinc finger transcription factor sharing conserved regions with Caenorhabditis elegans EGL-46 and Drosophila Nerfin-1. INSM, EGL-46, and Nerfin proteins comprise the EIN family of zinc finger transcription factors. egl-46 and nerfin-1 have been implicated in various aspects of neuronal differentiation including cell fate specification, axon guidance decisions and cell migration. Murine Insm1 has a restricted expression pattern in the developing CNS. We have characterized two zebrafish (Danio rerio) Insm1-like genes, insm1a and insm1b, and analyzed their expression patterns during embryonic development. Zebrafish insm1a and insm1b share an embryonic expression pattern comparable to the proneural deltaA as well as overlapping the neuronal marker elavl3. The expression pattern observed for zebrafish insm1a and insm1b is similar to other EIN homologues. Both zebrafish insm1-like transcripts are also present in a region of the embryo where pancreatic progenitors originate. The expression data along with functional characterization of invertebrate homologues suggest a conserved pathway involving the EIN transcription factors in early neurogenesis.

Glucagon-like peptide 1 increases secretory burst mass of pulsatile insulin secretion in patients with type 2 diabetes and impaired glucose tolerance.

The insulinotropic gut hormone glucagon-like peptide (GLP)-1 increases secretory burst mass and the amplitude of pulsatile insulin secretion in healthy volunteers without affecting burst frequency. Effects of GLP-1 on secretory mechanisms in type 2 diabetic patients and subjects with impaired glucose tolerance (IGT) known to have impaired pulsatile release of insulin have not yet been studied. Eight type 2 diabetic patients (64+/-9 years, BMI 28.9+/-7.2 kg/m2, HbA1c 7.7+/-1.3%) and eight subjects with IGT (63+/-10 years, BMI 31.7+/-6.4 kg/m2, HbA1c 5.7+/-0.4) were studied on separate occasions in the fasting state during the continued administration of exogenous GLP-1 (1.2 pmol x kg(-1) x min(-1), started at 10:00 P.M. the evening before) or placebo. For comparison, eight healthy volunteers (62+/-7 years, BMI 27.7+/-4.8 kg/m2, HbA1c 5.4+/-0.5) were studied only with placebo. Blood was sampled continuously over 60 min (roller-pump) in 1-min fractions for the measurement of plasma glucose and insulin. Pulsatile insulin secretion was characterized by deconvolution, autocorrelation, and spectral analysis and by estimating the degree of randomness (approximate entropy). In type 2 diabetic patients, exogenous GLP-1 at approximately 90 pmol/l improved plasma glucose concentrations (6.4+/-2.1 mmol/l vs. placebo 9.8+/-4.1 mmol/l, P = 0.0005) and significantly increased mean insulin burst mass (by 68%, P = 0.007) and amplitude (by 59%, P = 0.006; deconvolution analysis). In IGT subjects, burst mass was increased by 45% (P = 0.019) and amplitude by 38% (P = 0.02). By deconvolution analysis, insulin secretory burst frequency was not affected by GLP-1 in either type 2 diabetic patients (P = 0.15) or IGT subjects (P = 0.76). However, by both autocorrelation and spectral analysis, GLP-1 prolonged the period (lag time) between subsequent maxima of insulin concentrations significantly from approximately 9 to approximately 13 min in both type 2 diabetic patients and IGT subjects. Under placebo conditions, parameters of pulsatile insulin secretion were similar in normal subjects, type 2 diabetic patients, and IGT subjects based on all methodological approaches (P > 0.05). In conclusion, intravenous GLP-1 reduces plasma glucose in type 2 diabetic patients and improves the oscillatory secretion pattern by amplifying insulin secretory burst mass, whereas the oscillatory period determined by autocorrelation and spectral analysis is significantly prolonged. This was not the case for the interpulse interval determined by deconvolution. Together, these results suggest a normalization of the pulsatile pattern of insulin secretion by GLP-1, which supports the future therapeutic use of GLP-1-derived agents.

Cloning and analysis of the alternative oxidase gene of Neurospora crassa.

Mitochondria of Neurospora crassa contain a cyanide-resistant alternative respiratory pathway in addition to the cytochrome pathway. The alternative oxidase is present only when electron flow through the cytochrome chain is restricted. Both genomic and cDNA copies for the alternative oxidase gene have been isolated and analyzed. The sequence of the predicted protein is homologous to that of other species. The mRNA for the alternative oxidase is scarce in wild-type cultures grown under normal conditions, but it is abundant in cultures grown in the presence of chloramphenicol, an inhibitor of mitochondrial protein synthesis, or in mutants deficient in mitochondrial cytochromes. Thus, induction of alternative oxidase appears to be at the transcriptional level. Restriction fragment length polymorphism mapping of the isolated gene demonstrated that it is located in a position corresponding to the aod-1 locus. Sequence analysis of mutant aod-1 alleles reveals mutations affecting the coding sequence of the alternative oxidase. The level of aod-1 mRNA in an aod-2 mutant strain that had been grown in the presence of chloramphenicol was reduced several fold relative to wild-type, supporting the hypothesis that the product of aod-2 is required for optimal expression of aod-1.

Topical reversion at the HIS1 locus of Saccharomyces cerevisiae. A tale of three mutants.

Mutants of the HIS1 locus of the yeast Saccharomyces cerevisiae are suitable reporters for spontaneous reversion events because most reversions are topical, that is, within the locus itself. Thirteen mutations of his1-1 now have been identified with respect to base sequence. Revertants of three mutants and their spontaneous reversion rates are presented: (1) a chain termination mutation (his1-208, née his1-1) that does not revert by mutations of tRNA loci and reverts only by intracodonic suppression; (2) a missense mutation (his1-798, née his1-7) that can revert by intragenic suppression by base substitutions of any sort, including a back mutation as well as one three-base deletion; and (3) a -1 frameshift mutation (his1-434, née his1-19) that only reverts topically by +1 back mutation, +1 intragenic suppression, or a -2 deletion. Often the +1 insertion is accompanied by base substitution events at one or both ends of a run of A's. Missense suppressors of his1-798 are either feeders or nonfeeders, and at four different locations within the locus, a single base substitution encoding an amino acid alteration will suffice to turn the nonfeeder phenotype into a feeder phenotype. Late-appearing revertants of his1-798 were found to be slowly growing leaky mutants rather than a manifestation of adaptive mutagenesis. Spontaneous revertants of his1-208 and his1-434 produced no late-arising colonies.

Influence of glucagon-like peptide 1 on fasting glycemia in type 2 diabetic patients treated with insulin after sulfonylurea secondary failure.

OBJECTIVE: Glucagon-like peptide 1 (GLP-1) has glucose-dependent insulinotropic and glucagonostatic actions in type 2 diabetic patients on diet and on oral agents. It is not known, however, whether after secondary sulfonylurea failure, GLP-1 is still effective. RESEARCH DESIGN AND METHODS: Therefore, 10 type 2 diabetic patients (6 women, 4 men; age 65+/-10 years, BMI 30.4+/-5.1 kg/m2, HbA1c 8.2+/-1.5%, 6+/-3 [2-13] years after starting insulin treatment) were examined in the fasting state after discontinuing NPH insulin on the evening before the two study days. GLP-1 (1.2 pmol x kg(-1) x min(-1) or placebo (NaCl with 1% human serum albumin) were infused over 6 h. Plasma glucose (glucose oxidase) insulin (IMx), and C-peptide (enzyme-linked immunosorbent assay) were measured. Statistical analysis was performed using repeated measures analysis of variance. RESULTS: Fasting plasma glucose was 9.4+/-0.5 mmol/l and was reduced by GLP-1 to 5.3+/-0.3 (3.9-7.3) mmol/l (placebo: 8.2+/-0.7 mmol/l; P < 0.0001). GLP-1 transiently increased insulin (from 115+/-31 to 222+/-64 pmol/l at 150 min; P < 0.0001) and C-peptide (from 1.00+/-0.12 to 1.90+/-0.23 nmol/l at 120 min; P < 0.0001) with no effect of placebo. Glucagon and free fatty acids were lowered transiently. After normalization of plasma glucose, insulin and C-peptide concentrations became lower again during the ongoing administration of exogenous GLP-1, and no hypoglycemia occurred. CONCLUSIONS: It is concluded that exogenous GLP-1 effectively lowers plasma glucose concentrations in advanced type 2 diabetes long after sulfonylurea secondary failure. These findings may broaden the applicability of GLP-1-derived drugs as a new treatment to nearly all type 2 diabetic patients.

The phosphofructokinase genes of yeast evolved from two duplication events.

Yeast phosphofructokinase (PFK) is an octameric enzyme composed of four alpha-subunits and four beta-subunits, encoded by the genes PFK1 and PFK2, respectively. PFK1 was mapped 23 cM distal to ADE3 on chromosome VII, and PFK2 30 cM proximal to RNA1 on chromosome XIII. The entire nucleotide sequences for the two genes were obtained by sequencing both DNA strands. Only one major open reading frame was found for each gene. They encode 987 aa for PFK1 (Mr 107,984) and 959 aa for PFK2 (Mr 104,589). Both genes show a biased codon usage. The deduced amino acid sequences showed: (i) 20% homology between the N- and the C-terminal halves of each subunit, (ii) 55% homology between the two subunits, and (iii) significant homologies to the PFK sequences from human and rabbit muscle (42%), Escherichia coli (34%), and Bacillus (36%). These data support the view that two gene duplication events occurred in the evolution of the yeast PFK genes. The first duplication event took place soon after the separation of prokaryotic and eukaryotic lineage and the second in Saccharomyces later in the phylogeny. Functional domains in the yeast subunits were deduced by comparison to the rabbit muscle enzyme.

Combined pancreas and kidney transplantation in a lean type 2 diabetic patient. Effects on insulin secretion and sensitivity.

BACKGROUND/AIMS: Pancreas transplantation is an established method of treating Type 1 diabetes. It was our aim to test the consequences of pancreas transplantation in a Type 2 diabetic patient by determining insulin secretion and sensitivity before and after surgery. PATIENTS AND METHODS: A female patient with Type 2 diabetes and end-stage nephropathy was treated with combined pancreas and kidney transplantation. Before surgery and at 4 weeks, 6 months and 2 years afterwards, insulin sensitivity was measured using hyperinsulinemic euglycemic clamps and insulin secretion was quantified after oral glucose or intravenous glucagon challenges. RESULTS: The patient was insulin resistant before surgery (glucose infusion 4.6 mg. kg (-1). min (-1), normal range 6.4 +/- 0.5 mg.kg( -1). min (-1). Insulin sensitivity declined further after transplantation (1.4 and 3.0 mg. kg -1. min -1 after 4 weeks and 6 months, respectively), but improved to 5.4 mg. kg (-1). min (-1) after 2 years. Insulin secretion was greatly impaired before surgery. Insulin and C-peptide responses after oral glucose and intravenous glucagon increased into the normal range from 6 months after surgery onwards and oral glucose tolerance remained non-diabetic (IGT). CONCLUSIONS: Insulin resistance is first aggravated after pancreas transplantation, probably due to immunosuppressive treatment including glucocorticoids, but improves on the long term. The initially impaired insulin secretion from the transplant may also be explained by the action of glucocorticoids or by transient and reversible organ damage.

The mutator mut7-1 of Saccharomyces cerevisiae.

The mut7-1 mutant of Saccharomyces cerevisiae is a cell-division-cycle mutant, exhibiting temperature-sensitive lethality and enhancement of mutator activity with increases in temperature. The base-sequence alterations in mutants arising in a mut7-1 background differed from the control by there being a higher transversion/transition ratio and by the much increased production of multi-base deletions. The deletions were, in every instance, associated with repeated oligonucleotide sequences (3-8 bases in length), where one of the two sequences was removed during the deletion process. The mutant mut7-1 failed to complement with cdc2, the temperature-sensitive mutant of the locus which encodes DNA polymerase III (delta).

Evaluating the mutagenic activity of targeted endonucleases containing a Sharkey FokI cleavage domain variant in zebrafish.

Synthetic targeted endonucleases such as zinc finger nucleases (ZFNs) and transcription activator-like effector nucleases (TALENs) have recently emerged as powerful tools for targeted mutagenesis, especially in organisms that are not amenable to embryonic stem cell manipulation. Both ZFNs and TALENs consist of DNA-binding arrays that are fused to the nonspecific FokI nuclease domain. In an effort to improve targeted endonuclease mutagenesis efficiency, we enhanced their catalytic activity using the Sharkey FokI nuclease domain variant. All constructs tested display increased DNA cleavage activity in vitro. We demonstrate that one out of four ZFN arrays containing the Sharkey FokI variant exhibits a dramatic increase in mutagenesis frequency in vivo in zebrafish. The other three ZFNs exhibit no significant alteration of activity in vivo. Conversely, we demonstrate that TALENs containing the Sharkey FokI variant exhibit absent or severely reduced in vivo mutagenic activity in zebrafish. Notably, Sharkey ZFNs and TALENs do not generate increased toxicity-related defects or mortality. Our results present Sharkey ZFNs as an effective alternative to conventional ZFNs, but advise against the use of Sharkey TALENs.