Identification of highest-affinity ligands by affinity selection from equimolar peptide mixtures generated by robotic synthesis

A fully automated peptide synthesizer has been constructed that is capable of the simultaneous synthesis of up to 36 individual peptides and the synthesis of equimolar peptide mixtures. The instrument consists of an array of reaction vessels, a series of solenoid valves to control liquid flow, and a Zymark robot to deliver solvents and reagents; all components are computer controlled and coordinated. Equimolar peptide mixtures are obtained by algorithms that automate the mixing and distribution of peptide-resin particles. This technology was used to synthesize a library of 361 peptides, generated by randomizing two critical binding residues of a 10-mer epitope known to bind an anti-human immuno-deficiency virus gp120 monoclonal antibody. Each critical residue was substituted with 19 amino acids consisting of all the natural amino acids except cysteine. The library was synthesized as 19 pools, each containing 19 peptides. Each pool was screened in a solution-phase competition ELISA assay. The 12 most inhibitory peptides in the library were isolated by a rapid affinity-selection method and were identified by mass spectrometry and amino acid analysis. The binding properties of these 12 selected peptides were verified by synthesis and assay of the individual peptides. The two critical residues investigated were found to contribute independently to antibody binding.     

Combination of renin-angiotensin system polymorphisms is associated with altered renal sodium handling and hypertension

Genes of the renin-angiotensin-aldosterone system (RAAS) are natural candidates for sodium homeostasis and blood pressure regulation. To investigate the effect of a combination of polymorphisms of RAAS genes on renal sodium handling and blood pressure, 918 participants to the Olivetti Heart Study were genotyped for the following polymorphisms: I/D of angiotensin converting enzyme (ACE), M235T of angiotensinogen (AGT), A1166C of angiotensin II type-1 receptor (AT1R), and C-344T of aldosterone synthase (CYP11B2). The segmental renal sodium handling was evaluated by the fractional excretions of exogenous lithium (FE-Li), uric acid (FE-UA), and sodium (FE-Na). Twenty-eight carriers of triple homozygosity for M (AGT), A (AT1R), and C (CYP11B2) in the presence of the D allele of ACE (DD/ID) showed lower FE-Li (20.0%+/-5.9% versus 25.0%+/-7.5%; P=0.004; mean+/-sD), FE-UA (6.3%+/-2.0% versus 8.2%+/-2.7%; P=0.001), and FE-Na (0.96%+/-0.41% versus 1.22%+/-0.61%; P=0.004) as compared with all other allelic combinations (n=890), independently from age and body mass, suggesting an enhanced rate of proximal tubular sodium reabsorption. The carriers of the MM, AA, CC, DD/ID combination showed a substantially higher probability of being hypertensive (OR: 3.4 [(99% CI: 1.1 to 10.1]), independently of age and body mass. This relatively rare combination of allelic variants of candidate genes of the RAAS is associated with a significant alteration in proximal renal sodium handling and with higher risk of hypertension, suggesting that a combination of polymorphic variants at different candidate loci may affect phenotypic expression even in the absence of detectable effects of each variant at any single locus.     

Cardiac CT and MRI guide surgery in impending left ventricular rupture after acute myocardial infarction

We report the case of a 67 year-old patient who presented with worsening chest pain and shortness of breath, four days post acute myocardial infarction. Contrast enhanced computed tomography of the chest ruled out a pulmonary embolus but revealed an unexpected small subepicardial aneurysm (SEA) in the lateral left ventricular wall which was confirmed on cardiac magnetic resonance imaging. Intraoperative palpation of the left lateral wall was guided by the cardiac MRI and CT findings and confirmed the presence of focally thinned and weakened myocardium, covered by epicardial fat. An aneurysmorrhaphy was subsequently performed in addition to coronary bypass surgery and a mitral valve repair. The patient was discharged home on post operative day eight in good condition and is feeling well 2 years after surgery.     

Use of Temporary Enteral Access Devices in Hospitalized Neonatal and Pediatric Patients in the United States

Background: Temporary enteral access devices (EADs), such as nasogastric (NG), orogastric (OG), and postpyloric (PP), are used in pediatric and neonatal patients to administer nutrition, fluids, and medications. While the use of these temporary EADs is common in pediatric care, it is not known how often these devices are used, what inpatient locations have the highest usage, what size tube is used for a given weight or age of patient, and how placement is verified per hospital policy. Materials and Methods: This was a multicenter 1‐day prevalence study. Participating hospitals counted the number of NG, OG, and PP tubes present in their pediatric and neonatal inpatient population. Additional data collected included age, weight and location of the patient, type of hospital, census for that day, and the method(s) used to verify initial tube placement. Results: Of the 63 participating hospitals, there was an overall prevalence of 1991 temporary EADs in a total pediatric and neonatal inpatient census of 8333 children (24% prevalence). There were 1316 NG (66%), 414 were OG (21%), and 261 PP (17%) EADs. The neonatal intensive care unit (NICU) had the highest prevalence (61%), followed by a medical/surgical unit (21%) and pediatric intensive care unit (18%). Verification of EAD placement was reported to be aspiration from the tube (n = 21), auscultation (n = 18), measurement (n = 8), pH (n = 10), and X‐ray (n = 6). Conclusion: The use of temporary EADs is common in pediatric care. There is wide variation in how placement of these tubes is verified.     

A SEARCH FOR UNHAPPY ABDOMEN: PREVALENCE OF IRRITABLE BOWEL SYNDROME IN GENERAL POPULATION

The irritable bowel syndrome is the commonest gastrointestinal disorder seen in practice but its exact prevalence in India is not known. This study was carried out to determine the prevalence of symptoms compatible with this diagnosis in general population. A cross sectional random sample survey was conducted in various strata of urban population in Wanoworie area of Pune. Survey utilized personal interviews based on a questionnaire. Symptoms were evaluated as per Manning criteria and the diagnosis of irritable bowel syndrome was defined by Kruis diagnostic index. Of the 1010 subjects interviewed, 370 (37%) reported more than 6 episodes of abdominal pain in previous 6 months, with 333 reporting symptoms consistent with the the diagnosis of irritable bowel syndrome. At least one of the Manning''s symptoms was present in 307 out of 370 subjects (83%). The male female ratio was 5.3:1. Among males, 288 (35%) and among females 82 (53.2%) persons had at least some degree of abdominal discomfort. Other common symptoms were: excessive passage of wind (42.2%), irregular bowel habits (33%), excessive belching (30.8%), constipation (27.5) and feeling of incomplete evacuation(28.1%). About one third of the symptomatic subjects (134 or 36.2%) had seen a doctor or wanted to be seen by a specialist. Overall prevalence of the symptoms consistent with irritable bowel syndrome thus, is 33 per cent though only about a third of these may possibly consult a doctor. Follow up of all these patients for a mean duration of 8.3 months showed that no case of organic disease was picked up either by the scoring system or by the gastroenterologist. Symptoms consistent with the diagnosis of irritable bowel syndrome are see in almost one third of the study population residing in Wanoworie area of Pune.KEYWORDS: Irritable bowel syndrome, Kruis diagnostic index, Manning''s symptoms     

Impact of Early Initiation of Enteral Nutrition on Survival During Pediatric Extracorporeal Membrane Oxygenation

Introduction: Pediatric data related to safety, tolerance, and outcomes of enteral nutrition (EN) for patients requiring extracorporeal membrane oxygenation (ECMO) are lacking. The objectives of this study were to evaluate early nutrition status and timing of EN initiation on survival during pediatric ECMO. Methods: A single center institutional review board–approved retrospective chart review was performed on all pediatric patients requiring ECMO from October 2008 through December 2013. Demographics, ECMO variables, laboratory values, vasoactive inotropic score (VIS), and nutrition data on day 5 (d5) were collected. Patients receiving parenteral nutrition (PN) were compared with those receiving any EN on d5. Analyses were conducted to identify factors influencing survival to completion of ECMO and to discharge. Results: Forty‐nine patients aged 53 ± 76 months met inclusion criteria. Kaplan‐Meier curves demonstrated greater survival to discharge in patients receiving any EN, compared with only receiving PN (P = .031). EN on d5 of ECMO support (P = .040) and a higher percentage of daily energy intake achieved (P = .013) were protective, whereas a higher VIS was associated with increased mortality (P = .010). Multivariable analysis demonstrated EN was no longer associated with survival to discharge (P = .139), whereas energy intake (P = .021) and VIS (P = .013) remained significant. Conclusions: Pediatric patients who received nutrition that was closer to goal energy intake, as well as those who received any EN early during ECMO, had improved survival to hospital discharge.     

The importance of the mesofascial interface in complete mesocolic excision

Complete mesocolic excision (CME) with Central Vascular Ligation (CVL) is progressively gaining acceptance as the most updated surgical treatment in the multimodal management of colonic cancer. The concept is based on excision of the affected organ with its related primitive dorsal mesenterium as an intact package to maximize local clearance, and high tie ligation to boost regional control, translating the original concept of Total Mesorectal Excision proposed by Heald for rectal cancer. Aim of this review is to analyze the modern concept of the mesenteric organ, with particular regard to the interfaces between its single components and the importance of the meso-fascial interface as the correct plane of separation.The integrity of the mesocolon excised along the meso-fascial interface (meso-fascial separation) prevents any breach of its surface and underlying structures, preserving the radial margin and the complex network of the meso-structure, avoiding any spillage of neoplastic cells within the surgical field. Central Vascular ligation allows for the most effective harvesting of lymph nodes, particularly of the apical ones, whose removal appears to be crucial in optimizing regional control.A surgical plane developed along the meso-fascial interface, coupled with high tie ligation, yields higher quality of surgical specimen, with better oncologic outcome in terms of local recurrence rate, disease-free and overall survival.     

Body mass index, migraine, migraine frequency and migraine features in women

We evaluated the association of body mass index (BMI) with migraine and migraine specifics in a cross-sectional study of 63 467 women aged ≥ 45 years, of whom 12 613 (19.9%) reported any history of migraine and 9195 had active migraine. Compared with women without migraine and a BMI < 23 kg/m², women with a BMI ≥ 35 kg/m² had adjusted odds ratios (ORs) (95% confidence intervals) of 1.03 (0.95, 1.12) for any history of migraine. Findings were similar for active migraineurs. Women with a BMI of ≥ 35 kg/m² had increased risk for low and high migraine frequency, with the highest estimate for women who reported daily migraine. Compared with women with the lowest associated risk (migraine frequency < 6 times/year; BMI between 27.0 and 29.9 kg/m²), women with a BMI ≥ 35 kg/m² had an OR of daily migraine of 3.11 (1.12, 8.67). Among the women with active migraine, a BMI ≥ 35 kg/m² was associated with increased risk of phonophobia and photophobia and decreased risk of a unilateral pain characteristic and migraine aura. Our data confirm previous findings that the association between BMI with migraine is limited to migraine frequency and specific migraine features.