Insulin-degrading enzyme higher in subjects with metabolic syndrome

Metabolic syndrome (MS) is comprised of a cluster of abnormalities in glucose, lipid, and vascular homeostasis, which is most commonly linked to abdominal obesity. MS heralds increased risk for development of diabetes and is linked to impairment in insulin signaling. Insulin-degrading enzyme (IDE) is one of the mechanisms through which insulin blood levels are maintained. It has been previously suggested that controlling IDE levels could provide yet another potential therapeutic approach in diabetes. Here we aim to investigate whether changes in serum IDE levels correlate with the severity of MS. Using a highly sensitive ELISA assay of active IDE in human serum, we found a strong correlation between circulating IDE levels and circulating levels of triglycerides, insulin, and c-peptide and an inverse correlation with HDL cholesterol (HDLc). Serum IDE levels were higher in MS subjects than in control subjects. Hence, circulating IDE may serve as a tool to identify subjects with abnormal insulin metabolism, possibly those with MS that are at risk to develop diabetes.

Sodium-site in serine protease domain of human coagulation factor IXa: evidence from the crystal structure and molecular dynamics simulations study

Essentials Consensus sequence and biochemical data suggest a Na+ -site in the factor (F) IXa protease domain. X-ray structure of the FIXa EGF2/protease domain at 1.37 Å reveals a Na+ -site not observed earlier. Molecular dynamics simulations data support that Na+  ± Ca2+ promote FIXa protease domain stability. Sulfate ions found in the protease domain mimic heparin sulfate binding mode in FIXa. SUMMARY: Background Activated coagulation factor IX (FIXa) consists of a γ-carboxyglutamic acid domain, two epidermal growth factor-like (EGF) domains, and a C-terminal protease domain. Consensus sequence and biochemical data support the existence of a Na+ -site in the FIXa protease domain. However, soaking experiments or crystals grown in high concentration of ammonium sulfate did not reveal a Na+ -site in wild-type or mutant FIXa EGF2/protease domain structure. Objective Determine the structure of the FIXa EGF2/protease domain in the presence of Na+ ; perform molecular dynamics (MD) simulations to explore the role of Na+ in stabilizing FIXa structure. Methods Crystallography, MD simulations, and modeling heparin binding to FIXa. Results Crystal structure at 1.37-Å resolution revealed that Na+ is coordinated to carbonyl groups of residues 184A, 185, 221A, and 224 in the FIXa protease domain. The Na+ -site in FIXa is similar to that of FXa and is linked to the Asp189 S1-site. In MD simulations, Na+ reduced fluctuations in residues 217-225 (Na+ -loop) and 70-80 (Ca2+ -loop), whereas Ca2+ reduced fluctuations only in residues of the Ca2+ -loop. Ca2+ and Na+ together reduced fluctuations in residues of the Ca2+ -loop and Na+ -loop (residues 70-80, 183-194, and 217-225). Moreover, we observed four sulfate ions that make salt bridges with FIXa protease domain Arg/Lys residues, which have been implicated in heparin binding. Based upon locations of the sulfate ions, we modeled heparin binding to FIXa, which is similar to the heparin binding in thrombin. Conclusions The FIXa Na+ -site in association with Ca2+ contributes to stabilization of the FIXa protease domain. The heparin binding mode in FIXa is similar to that in thrombin.

Identification and characterization of novel ligase I inhibitors

The terminal step of ligation of single and/or double-strand breaks during physiological processes such as DNA replication, repair and recombination requires participation of DNA ligases in all mammals. DNA Ligase I has been well characterised to play vital roles during these processes. Considering the indispensable role of DNA Ligase I, a therapeutic strategy to impede proliferation of cancer cells is by using specific small molecule inhibitors against it. In the present study, we have designed and chemically synthesised putative DNA Ligase I inhibitors. Based on various biochemical and biophysical screening approaches, we identify two prospective DNA Ligase I inhibitors, SCR17 and SCR21. Both the inhibitors blocked ligation of nicks on DNA in a concentration-dependent manner, when catalysed by cell-free extracts or purified Ligase I. Docking studies in conjunction with biolayer interferometry and gel shift assays revealed that both SCR17 and SCR21 can bind to Ligase I, particularly to the DNA Binding Domain of Ligase I with KD values in nanomolar range. The inhibitors did not show significant affinity towards DNA Ligase III and DNA Ligase IV. Further, addition of Ligase I could restore the joining, when the inhibitors were treated with testicular cell-free extracts. Ex vivo studies using multiple assays showed that even though cell death was limited in the presence of inhibitors in cancer cells, their proliferation was compromised. Hence, we identify two promising DNA Ligase I inhibitors, which can be used in biochemical and cellular assays, and could be further modified and optimised to target cancer cells. © 2016 Wiley Periodicals, Inc.

Correction: Selective Preference of Parallel DNA Triplexes Is Due to the Disruption of Hoogsteen Hydrogen Bonds Caused by the Severe Nonisostericity between the G*GC and T*AT Triplets

[This corrects the article DOI: 10.1371/journal.pone.0152102.].

Selective Preference of Parallel DNA Triplexes Is Due to the Disruption of Hoogsteen Hydrogen Bonds Caused by the Severe Nonisostericity between the G*GC and T*AT Triplets

Implications of DNA, RNA and RNA.DNA hybrid triplexes in diverse biological functions, diseases and therapeutic applications call for a thorough understanding of their structure-function relationships. Despite exhaustive studies mechanistic rationale for the discriminatory preference of parallel DNA triplexes with G*GC & T*AT triplets still remains elusive. Here, we show that the highest nonisostericity between the G*GC & T*AT triplets imposes extensive stereochemical rearrangements contributing to context dependent triplex destabilisation through selective disruption of Hoogsteen scheme of hydrogen bonds. MD simulations of nineteen DNA triplexes with an assortment of sequence milieu reveal for the first time fresh insights into the nature and extent of destabilization from a single (non-overlapping), double (overlapping) and multiple pairs of nonisosteric base triplets (NIBTs). It is found that a solitary pair of NIBTs, feasible either at a G*GC/T*AT or T*AT/G*GC triplex junction, does not impinge significantly on triplex stability. But two overlapping pairs of NIBTs resulting from either a T*AT or a G*GC interruption disrupt Hoogsteen pair to a noncanonical mismatch destabilizing the triplex by ~10 to 14 kcal/mol, implying that their frequent incidence in multiples, especially, in short sequences could even hinder triplex formation. The results provide (i) an unambiguous and generalised mechanistic rationale for the discriminatory trait of parallel triplexes, including those studied experimentally (ii) clarity for the prevalence of antiparallel triplexes and (iii) comprehensive perspectives on the sequence dependent influence of nonisosteric base triplets useful in the rational design of TFO's against potential triplex target sites.

An innate twist between Crick's wobble and Watson-Crick base pairs

Non-Watson-Crick pairs like the G·U wobble are frequent in RNA duplexes. Their geometric dissimilarity (nonisostericity) with the Watson-Crick base pairs and among themselves imparts structural variations decisive for biological functions. Through a novel circular representation of base pairs, a simple and general metric scheme for quantification of base-pair nonisostericity, in terms of residual twist and radial difference that can also envisage its mechanistic effect, is proposed. The scheme is exemplified by G·U and U·G wobble pairs, and their predicable local effects on helical twist angle are validated by MD simulations. New insights into a possible rationale for contextual occurrence of G·U and other non-WC pairs, as well as the influence of a G·U pair on other non-Watson-Crick pair neighborhood and RNA-protein interactions are obtained from analysis of crystal structure data. A few instances of RNA-protein interactions along the major groove are documented in addition to the well-recognized interaction of the G·U pair along the minor groove. The nonisostericity-mediated influence of wobble pairs for facilitating helical packing through long-range interactions in ribosomal RNAs is also reviewed.

An inhibitor of nonhomologous end-joining abrogates double-strand break repair and impedes cancer progression

DNA Ligase IV is responsible for sealing of double-strand breaks (DSBs) during nonhomologous end-joining (NHEJ). Inhibiting Ligase IV could result in amassing of DSBs, thereby serving as a strategy toward treatment of cancer. Here, we identify a molecule, SCR7 that inhibits joining of DSBs in cell-free repair system. SCR7 blocks Ligase IV-mediated joining by interfering with its DNA binding but not that of T4 DNA Ligase or Ligase I. SCR7 inhibits NHEJ in a Ligase IV-dependent manner within cells, and activates the intrinsic apoptotic pathway. More importantly, SCR7 impedes tumor progression in mouse models and when coadministered with DSB-inducing therapeutic modalities enhances their sensitivity significantly. This inhibitor to target NHEJ offers a strategy toward the treatment of cancer and improvement of existing regimens.

Formation of a G-quadruplex at the BCL2 major breakpoint region of the t(14;18) translocation in follicular lymphoma

The t(14;18) translocation in follicular lymphoma is one of the most common chromosomal translocations. Most breaks on chromosome 18 are located at the 3′-UTR of the BCL2 gene and are mainly clustered in the major breakpoint region (MBR). Recently, we found that the BCL2 MBR has a non-B DNA character in genomic DNA. Here, we show that single-stranded DNA modeled from the template strand of the BCL2 MBR, forms secondary structures that migrate faster on native PAGE in the presence of potassium, due to the formation of intramolecular G-quadruplexes. Circular dichroism shows evidence for a parallel orientation for G-quadruplex structures in the template strand of the BCL2 MBR. Mutagenesis and the DMS modification assay confirm the presence of three guanine tetrads in the structure. 1H nuclear magnetic resonance studies further confirm the formation of an intramolecular G-quadruplex and a representative model has been built based on all of the experimental evidence. We also provide data consistent with the possible formation of a G-quadruplex structure at the BCL2 MBR within mammalian cells. In summary, these important features could contribute to the single-stranded character at the BCL2 MBR, thereby contributing to chromosomal fragility.

A phase II clinical trial utilizing maximum medical and surgical cytoredutive treatments for patients with metastatic colorectal cancer to the liver

e15130

Background: The median overall survival (‘OS‘) for patients with mCRC treated with chemotherapy is about 20.4 months. Combination chemotherapy with surgical cytoreduction for patients with liver metastases are evaluated in a phase II clinical trial. Methods: Patients with newly diagnosed mCRC to the liver or recurrent CRC after 5FU failure were consented to receive further chemotherapy with at least irinotecan-based chemotherapy, oxaliplatin-based chemotherapy, and with the intention to treat the liver metastases with either RFA and/or liver resection between chemotherapy regimens whenever possible. Bevacizamab and cetuximab were considered options for treatment after their respective FDA approvals. Chemotherapy was given until there was treatment failure. The primary endpoint was OS. Results: Between 2001 and 2004 thirty-seven patients aged 41 to 79 were consented. One remained alive by December 2008. Only patients with an ECOG performance status of 0–1 were consented. Twenty had been treated with 5FU for a stage III CRC befored developing mCRC. All patients received irinotecan in the form of FOLFIRI, IFL, or as a single agent. Thirty-six also received oxaliplatin in the form of either FOLFOX4 or 6. Twenty-two patients received cetuximab as a single agent. Some regimens were augmented with bevacizumab. Fourteen patients could not undergo resection or RFA because of performance status or progression. Three required radiation to the CNS or distant bone. There were eleven patients who underwent RFA of at least one liver metastasis. There were ten patients who underwent liver resection. One patient underwent both RFA and liver resection at two different times. Another patient underwent RFA, adrenalectomy and wedge resection of the lung at three different times. He remained alive at 78 months at the time of submission. Median OS was 34.5+ months at the time of submission. Patient survival ranged from 15 to 86 months. There were no deaths associated with any surgical intervention. Conclusions: OS was improved in mCRC patients or recurrent CRC patients who had potentially ablatable or resectable liver lesions at the time of their diagnosis and who were treated with available aggressive medical and surgical therapies.

[Table: see text]

Treatment of acute immune thrombocytopenic purpura

Medical history, physical examination, and laboratory testing are essential to arriving at the diagnosis of acute immune thrombocytopenic purpura (ITP). A history of recent viral illness occurs in about half of the pediatric patients who present with acute symptoms of ITP. The physical examination is normal except for purpura; a complete blood cell count with a differential white blood cell count can be used to confirm the diagnosis of acute ITP. Treatment decisions for acute ITP remain controversial. Treatment generally is designed to prevent life-threatening complications, such as intracranial hemorrhage, and may include single or combination therapy with corticosteroids, intravenous immunoglobulin (IVIg), anti-D, and splenectomy. Corticosteroids are inexpensive and offer an alluring option, especially in the recent era of cost-containment. The often slow platelet response and the potentially severe adverse effects of corticosteroid therapy are frequently a deterrent. IVIg usually leads to a rapid rise in platelet count; however, IVIg is very expensive and adverse effects associated with its infusion are common and sometimes troublesome. The role of anti-D in acute ITP is still evolving. It is similar to IVIg in platelet response and is considerably less expensive. Some degree of hemolysis, the main adverse reaction with anti-D, is inevitable due to the binding of anti-D antibody to Rh-positive erythrocytes. However, most cases of hemolysis do not require medical intervention. Splenectomy is reserved for refractory thrombocytopenia with life-threatening hemorrhage in acute ITP or after recurrent severe thrombocytopenia in chronic ITP. Other immunomodulatory therapies are also discussed.

Safety and efficacy of purified factor IX concentrate and antifibrinolytic agents for dental extractions in hemophilia B

This study evaluated the safety and efficacy of combined treatment with epsilon-aminocaproic acid or tranexamic acid and monoclonal antibody purified factor IX (MAb factor IX) for prophylaxis against bleeding in eight hemophilia B patients undergoing nine dental extraction procedures. All patients achieved excellent hemostasis without clinical evidence of thrombosis. There were no significant changes in hemoglobin or hematocrit or in markers of hemostatic system activation (prothrombin fragment F1+2, fibrinopeptide A, and fragment B beta 15-42) after surgery. Thus, a highly purified factor IX concentrate and antifibrinolytic therapy can be effectively and safely combined in hemophilia B patients undergoing dental extractions.

Effect of sleep quality on symptoms of irritable bowel syndrome

A prospective, one-month diary study was conducted with 23 adult irritable bowel syndrome (IBS) patients in order to determine the relationship between IBS and the quality of sleep. Subjects were screened through history and diagnostic studies. Accepted patients then completed a daily diary of IBS symptoms and sleep quality. At baseline, most subjects (74%) characterized themselves as "poor sleepers." Using pooled time series analysis, the study found a significant correlation between morning IBS symptoms and the quality of the prior night's sleep (P < 0.001), a finding not previously reported in the literature. A less strong but still significant correlation (P < 0.05) was found between end of day IBS symptoms and the quality of sleep during the prior evening. Morning IBS symptoms seem to rise or fall in close association with the prior night's quality of sleep. The study supports the hypothesis that IBS symptoms are related to a disturbance in sleep.

Addressing Arkansas' rural primary care challenges

Universal health coverage may become a reality by the year 2000 and implies a greater need for primary care physicians in rural Arkansas in the 21st century. We can start this decade to build the capacity for an outstanding rural primary care system for the next century. The number of rural primary care physicians can be increased by 1) placing a high priority on recruiting more students to primary care, 2) improving the attractiveness of rural practice, and 3) improving the long-term financial viability of rural primary care. The quality of rural primary care will be greatly influenced by changes in information technology. Medical outreach activities from urban centers to rural communities and changes in rural medical infrastructures will be necessary as we approach the year 2000.

Are immunoglobulins with lupus anticoagulant activity specific for phospholipids?

Recent studies have suggested that the lupus anticoagulant (LA) may be specific for prothrombin, prothrombin-phospholipid complexes, or beta 2 glycoprotein 1 (beta 2GP1) rather than phospholipids. We performed a series of experiments to determine whether LA is indeed phospholipid specific. IgG was purified from sera of six patients with the antiphospholipid syndrome (APS) and 10 healthy controls. The six IgG-APS preparations had both LA and anticardiolipin (aCL) activity. Incubation of the six IgG-APS preparations with cardiolipin (CL), phosphatidylserine (PS), phosphatidylcholine (PC), or PS/PC (20:80) liposomes in Tris-buffered saline, resulted in loss of LA activity from the supernatant. We postulated that loss of activity might have resulted from absorption of IgG LA antibodies by phospholipids, a dilutional effect, or the presence of phospholipids in the supernatant causing 'by-pass' of IgG LA inhibitory activity. To distinguish between these possibilities, we re-isolated IgG from the supernatants and re-tested them for LA activity. IgG re-isolated from the PS. CL and PS/PC supernatants had no LA activity, but LA activity remained in the PC supernatant. This suggested that IgG with LA activity was absorbed by negatively charged but not by zwitterionic phospholipids. In like manner, PS, CL and PS/PC, but not PC liposomes, absorbed IgG with aCL activity. Mixtures of the phospholipid liposomes with beta 2GP1 did not modify the absorption of IgG with LA or aCL activity. Finally, we demonstrated that IgG eluted from immunoglobulin-cardiolipin liposome complexes had LA activity. Based on these findings, we conclude that at least one population of antibodies with LA activity is phospholipid specific.

Human neutrophil adhesion to bovine aortic endothelium. Evidence for endothelial lipoxygenase activity

We examined the effect of phorbol myristate acetate on cultured bovine aortic endothelial cells to determine the role of endothelial cells in neutrophil-endothelial cell adhesive interactions. Confluent endothelial cells were preincubated with phorbol myristate acetate and other inflammatory signals including N-formylmethionyl-leucyl-phenylalanine (f-Met-Leu-Phe), the ionophore A23187, and thrombin; washed extensively; and incubated with 51Cr-labeled neutrophils. Preincubation of endothelium with A23187, phorbol ester, or thrombin increased adherence of neutrophils by 3.1-, 5.7-, and 3.7-fold over baseline. In contrast, f-Met-Leu-Phe preincubation failed to increase adhesion over baseline. Supernatants from endothelium preincubated with phorbol failed to augment adherence of untreated endothelial cells. Preincubation of endothelium with lipoxygenase inhibitors nordihydroguaiaretic acid (50 microM), 5,8,11,14-eicosatetraenoic acid (50 microM), and BW755C (50 microM) inhibited the effect of phorbol preincubation of endothelium significantly by 55, 27, and 22%, respectively. In contrast, inhibitors of cyclooxygenase and thromboxane synthase or thromboxane receptor antagonists had no effect on phorbol-induced adhesion. Specific desensitization of neutrophil adhesion to phorbol-treated endothelium could be demonstrated by prior exposure of neutrophils to low concentrations of leukotriene B4 (3.8 x 10(-10) M). Endothelium preincubated with phorbol but not f-Met-Leu-Phe or thrombin produced several fatty acid peaks at 280 nm, one of which comigrated with authentic leukotriene B4 (LTB4). This peak, isolated and purified, increased endothelial cell adherence in a temporal fashion in the same way as LTB4 and was demonstrated to be LTB4 by ultraviolet spectroscopy, high-performance liquid chromatography, and mass spectroscopy. These data demonstrate that endothelial cell-derived lipoxygenase metabolites, in particular LTB4, are involved, in part, in the acute regulation of neutrophil adhesion to endothelium induced by inflammatory signals such as phorbol ester.

Evidence that difference in size of fraternal twins may originate during early gestation: a case report

We describe a woman who conceived by in vitro fertilization (IVF) and embryo transfer (ET). Transvaginal ultrasound demonstrated at least 1 week's difference in size of twin gestations from 1 month post-transfer of embryos to delivery. Differences in sac size, crown-rump length, and gestational growth are discussed, as are implications of ultrasound in early pregnancy.

In vitro fertilization-embryo transfer in three women with ovarian failure

Attempts at in vitro fertilization-embryo transfer (IVF-ET) for women with hypergonadotropic hypogonadism and bilateral tubal disease demonstrated a very low fertilization rate and no clinical pregnancies.

Stimulation-dependent release of adenosine triphosphate from hippocampal slices

Schaffer collaterals of rat and mouse hippocampal slices were stimulated with bursts of pulses (300 Hz for 50 ms, 2-s intervals) for 30-s which caused a stable increase in the size of the population spike known as long-term potentiation. The release of adenosine triphosphate (ATP) was measured with a luciferase-luciferine system and the light emitted was recorded with a photomultiplier placed beneath a modified slice chamber. ATP release was observed shortly after the start of stimulation and was quantified by comparison with the response of standard solutions of ATP. No ATP release was observed in a Ca2+ free solution or after low frequency stimulation (1 Hz). Glutamate (2 mM), applied without electrical stimulation, did not evoke ATP release. Also, the glutamate receptor blocker, kynurenic acid (10 mM), did not block ATP release. It is concluded that ATP is released from electrically stimulated hippocampal slices from presynaptic nerve terminals in a calcium-dependent fashion and may play a role in the modulation of synaptic efficiency.

Assessing the functional status of older patients with chronic illness

The purpose of this study was to investigate the value of using a validated functional assessment instrument, the Sickness Impact Profile (SIP), with older, chronically ill patients seeking care at the family physician's office. The SIP was completed by the patient and the family physician on patients 55 years of age or older who were seen at a family practice residency clinic. The study used stratified, random assignment in an experimental design to compare physician and patient reaction to the SIP. Both physicians (residents and faculty) and patients felt the SIP was useful in detecting disabilities. Approximately half of the physicians felt the SIP was helpful in patient management. Patients reported twice as many disabilities as were reported by physicians. Half of the clinic physicians had the opportunity to review a patient's SIP immediately prior to a visit. They recognized more disabilities and agreed more often with the patients about the presence of a disability. The physicians felt the SIP was too lengthy to assimilate easily into the clinic setting. Use of a functional assessment instrument is advocated because of its ability to increase both physician awareness and physician-patient communication regarding the presence of a functional deficit.

Evidence for a role of 5-hydroxytryptamine in the responses of rat raphe magnus neurones to peripheral noxious stimuli

The role of serotoninergic mechanisms in the responses of neurones in the nucleus raphe magnus to peripheral noxious stimuli was investigated in rats anaesthetized with halothane. In normal animals a large proportion of neurones responded to peripheral noxious stimuli with excitation or inhibition, the direction of the response being dependent on the spontaneous activity of the neurone. Pretreatment with p-chlorophenylalanine (pCPA; 300 mg/kg X 3 days) led to a marked reduction in the number of cells responding to peripheral stimuli. Similarly, the injection of metergoline (5 mg/kg, i.v.) in normal animals caused a reduction in the magnitude of the neuronal responses to noxious stimuli. The results are discussed with regard to the role of serotoninergic mechanisms in the control of nociceptive transmission by this nucleus.

Irritable bowel syndrome: treatment update

Patients with irritable bowel syndrome may be classified as "psychologic reactors," "food reactors" or "mixed reactors." The management approach is tailored to the reactive pattern. Education and reassurance are paramount in the management of irritable bowel syndrome. Psychologic reactors may benefit from antidepressant therapy, psychotherapy, relaxation training and biofeedback. Eliminating offending foods from the diet may provide relief in food reactors. Regular exercise may be especially salutary in patients with constipation.

Factors influencing family practice residency selection: a national survey

The changes in family practice residency selection from 1978 to 1981 were studied by means of a questionnaire, and selection of family practice residency was identified by region. The relationship between the administrative status of family practice (department, division, or no formal unit) and selection of family practice residency was studied, and the opinions of medical school faculty respondents were sought concerning why interest in family practice has increased (or decreased) at their institution. The average percentage of graduates selecting family practice residency varies by region. Schools with stronger institutional commitment to family practice, as evidenced by departmental status, have a higher percentage of graduates entering family practice. Respondents felt that the presence or absence of student contact with family practice was the most important reason for changes seen in residency choice.

Fitzgerald factor (high molecular weight kininogen) clotting activity in human plasma in health and disease in various animal plasmas

Fitzgerald factor (high molecular weight kininogen) is an agent in normal human plasma that corrects the impaired in vitro surface-mediated plasma reactions of blood coagulation, fibrinolysis, and kinin generation observed in Fitzgerald trait plasma. To assess the possible pathophysiologic role of Fitzgerald factor, its titer was measured by a functional clot-promoting assay. Mean +/- SD in 42 normal adults was 0.99+/-0.25 units/ml, one unit being the activity in 1 ml of normal pooled plasma. No difference in titer was noted between normal men and women, during pregnancy, or after physical exercise. Fitzgerald factor activity was significantly reduced in the plasmas of eight patients with advanced hepatic cirrhosis (0.40+/-0.09 units/ml) and of ten patients with disseminated intravascular coagulation (0.60+/-0.30 units/ml), but was normal in plasmas of patients with other congenital clotting factor deficiencies, nephrotic syndrome, rheumatoid arthritis, systemic lupus erythematosus, or sarcoidosis, or under treatment with warfarin. The plasmas of 21 mammalian species tested appeared to contain Fitzgerald factor activity, but those of two avian, two repitilian, and one amphibian species did not correct the coagulant defect in Fitzgerald trait plasmas.