Novel insights into the co-selection of metal-driven antibiotic resistance in bacteria: a study of arsenic and antibiotic co-exposure.

The simultaneous development of antibiotic resistance in bacteria due to metal exposure poses a significant threat to the environment and human health. This study explored how exposure to both arsenic and antibiotics affects the ability of an arsenite oxidizer, Achromobacter xylosoxidans CAW4, to transform arsenite and its antibiotic resistance patterns. The bacterium was isolated from arsenic-contaminated groundwater in the Chandpur district of Bangladesh. We determined the minimum inhibitory concentration (MIC) of arsenite, cefotaxime, and tetracycline for A. xylosoxidans CAW4, demonstrating a multidrug resistance (MDR) trait. Following this determination, we aimed to mimic an environment where A. xylosoxidans CAW4 was exposed to both arsenite and antibiotics. We enabled the strain to grow in sub-MIC concentrations of 1 mM arsenite, 40 µg/mL cefotaxime, and 20 µg/mL tetracycline. The expression dynamics of the arsenite oxidase (aioA) gene in the presence or absence of antibiotics were analyzed. The findings indicated that simultaneous exposure to arsenite and antibiotics adversely affected the bacteria's capacity to metabolize arsenic. However, when arsenite was present in antibiotics-containing media, it promoted bacterial growth. The study observed a global downregulation of the aioA gene in arsenic-antibiotic conditions, indicating the possibility of increased susceptibility through co-resistance across the entire bacterial population of the environment. This study interprets that bacterial arsenic-metabolizing ability can rescue the bacteria from antibiotic stress, further disseminating environmental cross-resistance. Therefore, the co-selection of metal-driven antibiotic resistance in bacteria highlights the need for effective measures to address this emerging threat to human health and the environment.

Improving the substrate binding of acetyl-CoA carboxylase (AccB) from Streptomyces antibioticus through computational enzyme engineering.

Malonyl-CoA serves as the main building block for the biosynthesis of many important polyketides, as well as fatty acid-derived compounds, such as biofuel. Escherichia coli, Corynebacterium gultamicum, and Saccharomyces cerevisiae have recently been engineered for the biosynthesis of such compounds. However, the developed processes and strains often have insufficient productivity. In the current study, we used enzyme-engineering approach to improve the binding of acetyl-CoA with ACC. We generated different mutations, and the impact was calculated, which reported that three mutations, that is, S343A, T347W, and S350W, significantly improve the substrate binding. Molecular docking investigation revealed an altered binding network compared to the wild type. In mutants, additional interactions stabilize the binding of the inner tail of acetyl-CoA. Using molecular simulation, the stability, compactness, hydrogen bonding, and protein motions were estimated, revealing different dynamic properties owned by the mutants only but not by the wild type. The findings were further validated by using the binding-free energy (BFE) method, which revealed these mutations as favorable substitutions. The total BFE was reported to be -52.66 ± 0.11 kcal/mol for the wild type, -55.87 ± 0.16 kcal/mol for the S343A mutant, -60.52 ± 0.25 kcal/mol for T347W mutant, and -59.64 ± 0.25 kcal/mol for the S350W mutant. This shows that the binding of the substrate is increased due to the induced mutations and strongly corroborates with the docking results. In sum, this study provides information regarding the essential hotspot residues for the substrate binding and can be used for application in industrial processes.

How many kinases are druggable? A review of our current understanding.

There are over 500 human kinases ranging from very well-studied to almost completely ignored. Kinases are tractable and implicated in many diseases, making them ideal targets for medicinal chemistry campaigns, but is it possible to discover a drug for each individual kinase? For every human kinase, we gathered data on their citation count, availability of chemical probes, approved and investigational drugs, PDB structures, and biochemical and cellular assays. Analysis of these factors highlights which kinase groups have a wealth of information available, and which groups still have room for progress. The data suggest a disproportionate focus on the more well characterized kinases while much of the kinome remains comparatively understudied. It is noteworthy that tool compounds for understudied kinases have already been developed, and there is still untapped potential for further development in this chemical space. Finally, this review discusses many of the different strategies employed to generate selectivity between kinases. Given the large volume of information available and the progress made over the past 20 years when it comes to drugging kinases, we believe it is possible to develop a tool compound for every human kinase. We hope this review will prove to be both a useful resource as well as inspire the discovery of a tool for every kinase.

Skin sodium is increased in male patients with multiple sclerosis and related animal models.

Novel MRI techniques allow a noninvasive quantification of tissue sodium and reveal the skin as a prominent compartment of sodium storage in health and disease. Since multiple sclerosis (MS) immunopathology is initiated in the periphery and increased sodium concentrations induce proinflammatory immune cells, the skin represents a promising compartment linking high sodium concentrations and MS immunopathology. We used a 7-T sodium MRI (23Na-MRI) and inductively coupled plasma mass spectrometry to investigate the skin sodium content in two mouse models of MS. We additionally performed 3-T 23Na-MRI of calf skin and muscles in 29 male relapsing-remitting MS (RRMS) patients and 29 matched healthy controls. Demographic and clinical information was collected from interviews, and disease activity was assessed by expanded disability status scale scoring. 23Na-MRI and chemical analysis demonstrated a significantly increased sodium content in the skin during experimental autoimmune encephalomyelitis independent of active immunization. In male patients with RRMS, 23Na-MRI demonstrated a higher sodium signal in the area of the skin compared to age- and biological sex-matched healthy controls with higher sodium, predicting future disease activity in cranial MRI. In both studies, the sodium enrichment was specific to the skin, as we found no alterations of sodium signals in the muscle or other tissues. Our data add to the recently identified importance of the skin as a storage compartment of sodium and may further represent an important organ for future investigations on salt as a proinflammatory agent driving autoimmune neuroinflammation such as that in MS.

The heterogeneity of symptom reporting across study sites: a secondary analysis of a randomised placebo-controlled multicentre antimalarial trial.

INTRODUCTION: Symptoms reported following the administration of investigational drugs play an important role in decisions for registration and treatment guidelines. However, symptoms are subjective, and interview methods to quantify them are difficult to standardise. We explored differences in symptom reporting across study sites of a multicentre antimalarial trial, with the aim of informing trial design and the interpretation of safety and tolerability data. METHODS: Data were derived from the IMPROV trial, a randomised, placebo-controlled double blinded trial of high dose primaquine to prevent Plasmodium vivax recurrence conducted in eight study sites in Afghanistan, Ethiopia, Indonesia and Vietnam. At each follow up visit a 13-point symptom questionnaire was completed. The number and percentage of patients with clinically relevant symptoms following the administration of primaquine or placebo, were reported by study site including vomiting, diarrhoea, anorexia, nausea, abdominal pain and dizziness. Multivariable logistic regression was used to estimate the confounder-adjusted site-specific proportion of each symptom. RESULTS: A total of 2,336 patients were included. The greatest variation between sites in the proportion of patients reporting symptoms was for anorexia between day 0 and day 13: 97.3% (361/371) of patients in Arba Minch, Ethiopia, reported the symptom compared with 4.7% (5/106) of patients in Krong Pa, Vietnam. Differences attenuated slightly after adjusting for treatment arm, age, sex, day 0 parasite density and fever; with the adjusted proportion for anorexia ranging from 4.8% to 97.0%. Differences between sites were greater for symptoms graded as mild or moderate compared to those rated as severe. Differences in symptom reporting were greater between study sites than between treatment arms within the same study site. CONCLUSION: Despite standardised training, there was large variation in symptom reporting across trial sites. The reporting of severe symptoms was less skewed compared to mild and moderate symptoms, which are likely to be more subjective. Trialists should clearly distinguish between safety and tolerability outcomes. Differences between trial arms were much less variable across sites, suggesting that the relative difference in reported symptoms between intervention and control group is more relevant than absolute numbers and should be reported when possible. TRIAL REGISTRATION: Clinicaltrials.gov: NCT01814683; March 20th, 2013.

A challenging high-risk surgery for necrotizing pneumonia in a right bilobed lung.

BACKGROUND: Necrotizing pneumonia is rare in children and is one of the most serious complications of a lung infection caused by antibiotic failure. We present a 12-year-old leukopenic child with a long-lasting lung infection, presenting as having a lung hydatid cyst, but diagnosing with necrotizing pneumonia in the right bilobed lung. Failure to medical treatment and ongoing leukopenia justified surgical intervention with positive results. CASE PRESENTATION: The patient was referred to our teaching hospital's pediatric surgery department. He had previously been diagnosed with intestinal tuberculosis (TB) and received anti-TB treatment. On referral to our hospital, the patient was suffering from restlessness, frequent coughing, fever, vomiting, and diarrhea. Following the completion of the clinical work-up, a blood test revealed leukopenia (white blood cell count of 2100/microliter), a normal platelet count, and a lesion in the right lung. Computerized tomography scanning (CT-Scan) image reported a lung hydatid cyst. In the pediatrics ward, a broad-spectrum antibiotics regimen with triple-antibiotic therapy (linezolid, vancomycin, and metronidazole) was instituted and continued for a week with no response, but worsening of the condition. In the pediatric surgery ward, our decision for surgical intervention was due to the failure of medical treatment because of a pulmonary lesion. Our team performed right lung upper lobe anterior segment wedge resection due to necrotizing pneumonia and followed the patient 45 days post-operation with a reasonable result. CONCLUSION: Living in remote rural areas with low resources and inaccessibility to proper and specialized diagnostic and treatment centers will all contribute to an improper diagnosis and treatment of lung infection. In total, all of these will increase the morbidity and mortality due to lung necrosis in the pediatric population, regardless of their age. In low-resource facilities, high-risk patients can benefit from surgical intervention to control the ongoing infection process.

Exploring the medicinal potential of Dark Chemical Matters (DCM) to design promising inhibitors for PLpro of SARS-CoV-2 using molecular screening and simulation approaches.

The growing concerns and cases of COVID-19 with the appearance of novel variants i.e., BA.2.75. BA.5 and XBB have prompted demand for more effective treatment options that could overcome the risk of immune evasion. For this purpose, discovering novel small molecules to inhibit druggable proteins such as PLpro required for viral pathogenesis, replication, survival, and spread is the best choice. Compounds from the Dark chemical matter (DCM) database is consistently active in various screening tests and offer intriguing possibilities for finding drugs that are extremely selective or active against uncommon targets. Considering the essential role of PLpro, the current study uses DCMdatabase for the identification of potential hits using in silico virtual molecular screening and simulation approaches to inhibit the current and emerging variants of SARS-CoV-2. Our results revealed the 10 best compounds with docking scores between -7.99 to -7.03 kcal/mol better than the control drug (GRL0617) among which DC 5977-0726, DC 6623-2024, DC C879-0379 and DC D135-0154 were observed as the best hits. Structural-dynamics properties such as dynamic stability, protein packing, and residue flexibility demonstrated the pharmacologically favorable properties of these top hits in contrast to GRL0617. The hydrogen bonding half-life revealed that Asp164, Arg166, Tyr264, and Tyr268 have major contributions to the hydrogen bonding during the simulation. However, some of the important hydrogen bonds were missing in the control drug (GRL0617). Finally, the total binding free energy was reported to be -34.41 kcal/mol for GRL0617 (control), -41.03 kcal/mol for the DC5977-0726-PLpro, for the DC6623-2024-Plpro complex the TBE was -48.87 kcal/mol, for the for DCC879-0379-Plpro complex the TBE was -45.66 kcal/mol while for the DCD135-0154-PLpro complex the TBE was calculated to be -40.09 kcal/mol respectively, which shows the stronger potency of these compounds against PLpro and further in in vivo and in vitro test are required for the possible usage as potential drug against SARS-CoV-2.

Discovery of natural products to block SARS-CoV-2 S-protein interaction with Neuropilin-1 receptor: A molecular dynamics simulation approach.

Neuropilin-1 (NRP1) is a widely expressed cell surface receptor protein characterized by its pleiotropic function. Recent reports highlighted NRP1 as an additional entry point of the SARS-CoV-2 virus, enhancing viral infectivity by interacting with the S-protein of SARS-CoV-2. The ubiquitous distribution and mechanism of action of NRP1 enable the SARS-CoV-2 virus to attack multiple organs in the body simultaneously. Therefore, blocking NRP1 is a potential therapeutic approach against SARS-CoV-2 infection. The current study screened the South African natural compounds database (SANCDB) for molecules that can disrupt the SARS-CoV-2 S protein-NRP1 interaction as a potential antiviral target for SARS-CoV-2 cellular entry. Following excessive screening and validation analysis 3-O-Methylquercetin and Esculetin were identified as potential compounds to disrupt the S-protein-NRP1 interaction. Furthermore, to understand the conformational stability and dynamic features between NRP1 interaction with the selected natural products, we performed 200 ns molecular dynamics (MD) simulations. In addition, molecular mechanics-generalized Born surface area (MM/GBSA) was utilized to calculate the free binding energies of the natural products interacting with NRP1. 3-O-methylquercetin showed an inhibitory effect with binding energies ΔG of -25.52 ±â€¯0.04 kcal/mol to NRP1, indicating the possible disruption of the NRP1-S-protein interaction. Our analysis demonstrated that 3-O-methylquercetin presents a potential antiviral compound against SARS-CoV-2 infectivity. These results set the path for future functional in-vitro and in-vivo studies in SARS-CoV-2 research.

Higher infectivity of the SARS-CoV-2 new variants is associated with K417N/T, E484K, and N501Y mutants: An insight from structural data.

The evolution of the SARS-CoV-2 new variants reported to be 70% more contagious than the earlier one is now spreading fast worldwide. There is an instant need to discover how the new variants interact with the host receptor (ACE2). Among the reported mutations in the Spike glycoprotein of the new variants, three are specific to the receptor-binding domain (RBD) and required insightful scrutiny for new therapeutic options. These structural evolutions in the RBD domain may impart a critical role to the unique pathogenicity of the SARS-CoV-2 new variants. Herein, using structural and biophysical approaches, we explored that the specific mutations in the UK (N501Y), South African (K417N-E484K-N501Y), Brazilian (K417T-E484K-N501Y), and hypothetical (N501Y-E484K) variants alter the binding affinity, create new inter-protein contacts and changes the internal structural dynamics thereby increases the binding and eventually the infectivity. Our investigation highlighted that the South African (K417N-E484K-N501Y), Brazilian (K417T-E484K-N501Y) variants are more lethal than the UK variant (N501Y). The behavior of the wild type and N501Y is comparable. Free energy calculations further confirmed that increased binding of the spike RBD to the ACE2 is mainly due to the electrostatic contribution. Further, we find that the unusual virulence of this virus is potentially the consequence of Darwinian selection-driven epistasis in protein evolution. The triple mutants (South African and Brazilian) may pose a serious threat to the efficacy of the already developed vaccine. Our analysis would help to understand the binding and structural dynamics of the new mutations in the RBD domain of the Spike protein and demand further investigation in in vitro and in vivo models to design potential therapeutics against the new variants.

Preliminary Structural Data Revealed That the SARS-CoV-2 B.1.617 Variant's RBD Binds to ACE2 Receptor Stronger Than the Wild Type to Enhance the Infectivity.

The evolution of new SARS-CoV-2 variants around the globe has made the COVID-19 pandemic more worrisome, further pressuring the health care system and immunity. Novel variations that are unique to the receptor-binding motif (RBM) of the receptor-binding domain (RBD) spike glycoprotein, i. e. L452R-E484Q, may play a different role in the B.1.617 (also known as G/452R.V3) variant's pathogenicity and better survival compared to the wild type. Therefore, a thorough analysis is needed to understand the impact of these mutations on binding with host receptor (RBD) and to guide new therapeutics development. In this study, we used structural and biomolecular simulation techniques to explore the impact of specific mutations (L452R-E484Q) in the B.1.617 variant on the binding of RBD to the host receptor ACE2. Our analysis revealed that the B.1.617 variant possesses different dynamic behaviours by altering dynamic-stability, residual flexibility and structural compactness. Moreover, the new variant had altered the bonding network and structural-dynamics properties significantly. MM/GBSA technique was used, which further established the binding differences between the wild type and B.1.617 variant. In conclusion, this study provides a strong impetus to develop novel drugs against the new SARS-CoV-2 variants.

Short-course primaquine for the radical cure of Plasmodium vivax malaria: a multicentre, randomised, placebo-controlled non-inferiority trial.

BACKGROUND: Primaquine is the only widely used drug that prevents Plasmodium vivax malaria relapses, but adherence to the standard 14-day regimen is poor. We aimed to assess the efficacy of a shorter course (7 days) of primaquine for radical cure of vivax malaria. METHODS: We did a randomised, double-blind, placebo-controlled, non-inferiority trial in eight health-care clinics (two each in Afghanistan, Ethiopia, Indonesia, and Vietnam). Patients (aged ≥6 months) with normal glucose-6-phosphate dehydrogenase (G6PD) and presenting with uncomplicated vivax malaria were enrolled. Patients were given standard blood schizontocidal treatment and randomly assigned (2:2:1) to receive 7 days of supervised primaquine (1·0 mg/kg per day), 14 days of supervised primaquine (0·5 mg/kg per day), or placebo. The primary endpoint was the incidence rate of symptomatic P vivax parasitaemia during the 12-month follow-up period, assessed in the intention-to-treat population. A margin of 0·07 recurrences per person-year was used to establish non-inferiority of the 7-day regimen compared with the 14-day regimen. This trial is registered at ClinicalTrials.gov (NCT01814683). FINDINGS: Between July 20, 2014, and Nov 25, 2017, 2336 patients were enrolled. The incidence rate of symptomatic recurrent P vivax malaria was 0·18 (95% CI 0·15 to 0·21) recurrences per person-year for 935 patients in the 7-day primaquine group and 0·16 (0·13 to 0·18) for 937 patients in the 14-day primaquine group, a difference of 0·02 (-0·02 to 0·05, p=0·3405). The incidence rate for 464 patients in the placebo group was 0·96 (95% CI 0·83 to 1·08) recurrences per person-year. Potentially drug-related serious adverse events within 42 days of starting treatment were reported in nine (1·0%) of 935 patients in the 7-day group, one (0·1%) of 937 in the 14-day group and none of 464 in the control arm. Four of the serious adverse events were significant haemolysis (three in the 7-day group and one in the 14-day group). INTERPRETATION: In patients with normal G6PD, 7-day primaquine was well tolerated and non-inferior to 14-day primaquine. The short-course regimen might improve adherence and therefore the effectiveness of primaquine for radical cure of P vivax malaria. FUNDING: UK Department for International Development, UK Medical Research Council, UK National Institute for Health Research, and the Wellcome Trust through the Joint Global Health Trials Scheme (MR/K007424/1) and the Bill & Melinda Gates Foundation (OPP1054404).

Complete genome sequence of a potential foot-and-mouth disease virus serotype O vaccine strain from Bangladesh.

One of the six sublineages of the dominant O/ME-SA/Ind2001 lineage of foot-and-mouth disease virus (FMDV), Ind2001BD1 has already spread throughout 14 countries, including Bangladesh. Here, we report the complete genome sequence of the potential serotype O vaccine strain BAN/TA/Dh-301/2016, which has been shown to provide protection against all the circulating serotype O viruses in Bangladesh. The viral genome is 8,211 nucleotide (nt) long with an open reading frame (ORF) of 6999 nt. The ORF is flanked by a 1098-nt-long 5'-UTR and a 114-nt-long 3'-UTR. Compared to the Indian FMDV serotype O vaccine strain O/India/R2/75 (AF204276), ten mutations were identified in the major antigenic sites of BAN/TA/Dh-301/2016 (MK088170.1).

The glutathione degrading enzyme, Chac1, is required for calcium signaling in developing zebrafish: redox as an upstream activator of calcium.

Calcium signaling is essential for embryonic development but the signals upstream of calcium are only partially understood. Here, we investigate the role of the intracellular glutathione redox potential in calcium signaling using the Chac1 protein of zebrafish. A member of the γ-glutamylcyclotransferase family of enzymes, the zebrafish Chac1 is a glutathione-degrading enzyme that acts only on reduced glutathione. The zebrafish chac1 expression was seen early in development, and in the latter stages, in the developing muscles, brain and heart. The chac1 knockdown was embryonic lethal, and the developmental defects were seen primarily in the myotome, brain and heart where chac1 was maximally expressed. The phenotypes could be rescued by the WT Chac1 but not by the catalytically inactive Chac1 that was incapable of degrading glutathione. The ability of chac1 to alter the intracellular glutathione redox potential in the live animals was examined using Grx1-roGFP2. The chac1 morphants lacked the increased degree of cellular oxidation seen in the WT zebrafish. As calcium is also known to be critical for the developing myotomes, brain and heart, we further investigated if the chac1 knockdown phenotypes were a consequence of the lack of calcium signals. We observed using GCaMP6s, that calcium transients normally seen in the developing embryos were strongly attenuated in these knockdowns. The study thus identifies Chac1 and the consequent change in intracellular glutathione redox potential as important upstream activators of calcium signaling during development.

Knowledge, attitudes, behaviours and practices towards diabetes mellitus in Kuwait.

BACKGROUND: Rates of diabetes in Kuwait are among the highest in the world. AIMS: To inform prevention initiatives, this study assessed diabetes knowledge, attitudes towards it, and personal behaviour relating to risk factors among the Kuwaiti population. METHODS: A cross-sectional knowledge, attitudes, beliefs and practices survey of 1124 people was performed between July and September 2015. Descriptive analysis and χ2 tests were performed. RESULTS: Although most participants (94%) had heard of diabetes and 87% believed type 2 diabetes to be preventable, knowledge of risk factors was poor [family history (87%), age (44%), low exercise (10%), obesity (4%), diet (0%) and stress (0%)]. Dietary patterns in Kuwait were variable and, of concern, 42% of those with diabetes had been eating more since diagnosis. Lifestyle, particularly among Kuwaitis and people with diabetes, was sedentary - 47% of participants walked < 20 minutes per day. CONCLUSIONS: Despite the importance of diet and exercise for diabetes prevention, significant gaps in public education clearly exist. At a policy level, much remains to be done and intensified intersectoral programmes are required to improve public awareness.

Associations of adiposity and parental diabetes with prediabetes among adolescents in Kuwait: A cross-sectional study.

BACKGROUND: Prediabetes, a high-risk state for developing diabetes, has become more prevalent among children and adolescents in recent decades. This study sought to estimate the prevalence of prediabetes and assess its association with adiposity among adolescents in Kuwait. Also, to determine whether maternal and paternal history of diabetes associate with offspring prediabetes in a sex-specific manner. METHODS: A cross-sectional study was conducted by enrolling students (n = 1959; aged 14-19 years) attending high schools across Kuwait. Body mass index-for-age z-scores were estimated using the World Health Organization growth reference. Glycated hemoglobin A1c (HbA1c) was measured in capillary blood using point-of-care testing. Prediabetes was defined according to the diagnostic criteria of the American Diabetes Association (ADA; 5.7 ≤ HbA1c% ≤ 6.4) and the International Expert Committee (IEC; 6.0 ≤ HbA1c% ≤ 6.4). Adjusted prevalence ratios (aPR) and 95% confidence intervals (CI) were estimated using Poisson regression with robust variance estimation. RESULTS: According to the ADA criteria, 33.3% (620/1845) of participants had prediabetes; whereas, 8.5% (157/1845) met the IEC definition for prediabetes. Subjects classified as obese had higher prevalence of prediabetes compared to children in the thinness/normal group (aPR = 1.68, 95% CI: 1.44-1.95). Analysis stratified by offspring sex showed that maternal history of diabetes is associated with prediabetes among male offspring (aPR = 1.29, 95% CI: 1.02-1.63). In contrast, paternal history of diabetes showed an association with prediabetes among female offspring (aPR = 1.22, 95% CI: 1.01-1.48). CONCLUSIONS: Prediabetes affects a substantial proportion of adolescents in Kuwait and adiposity and parental diabetes being the main associated factors with prediabetes.

A convenient and reproducible method for the synthesis of astatinated 4-[211At]astato-l-phenylalanine via electrophilic desilylation.

The 211At-labeled compound, 4-[211At]astato-l-phenylalanine, is one of the most promising amino acid derivatives for use in targeted alpha therapy (TAT) for various cancers. Electrophilic demetallation of a stannyl precursor is the most widely used approach for labeling biomolecules with 211At. However, the low acid-resistance of the stannyl precursor necessitates the use of an N- and C-terminus-protected precursor, which results in a low overall radiochemical yield (RCY) due to the multiple synthetic steps involved. In this study, a deprotected organosilyl compound, 4-triethylsilyl-l-phenylalanine, was employed for the direct synthesis of astatinated phenylalanines. 211At was separately recovered from the irradiated 209Bi target using chloroform (CHCl3) and N-chlorosuccinimide-methanol (NCS-MeOH) solution. The RCYs of 4-[211At]astato-l-phenylalanine obtained from the triethylsilyl precursor with the use of 211At, isolated in CHCl3 and NCS-MeOH solution, were 75% and 64% respectively. In both cases, the retention time of the 4-[211At]astato-l-phenylalanine was found to be about 20 min, which showed reasonable correlation with the retention time of non-radioactive 4-halo-l-phenylalanines (4-chloro-, 4-bromo-, and 4-iodo-l-phenylalanine). The one-step reaction examined in this study involved mild reaction conditions (70 °C) and a short time (10 min) compared to the other currently reported procedures for astatination. Electrophilic desilylation was found to be very effective for the labeling of aromatic amino acids with 211At.

Infant and young child feeding patterns in Kuwait: results of a cross-sectional survey.

OBJECTIVE: The beneficial role of breast-feeding for maternal and child health is now well established. Its possible role in helping to prevent diabetes and obesity in children in later life means that more attention must be given to understanding how patterns of infant feeding are changing. The present study describes breast-feeding profiles and associated factors in Kuwait. Design/Setting/Subjects Interviews with 1484 recent mothers were undertaken at immunisation clinics across Kuwait. Descriptive analysis and binary logistic regression of results were performed. RESULTS: Rates of breast-feeding initiation in Kuwait were high (98·1 %) but by the time of discharge from hospital, only 36·5 % of mothers were fully breast-feeding, 37·0 % were partially breast-feeding and 26·5 % were already fully formula-feeding. Multiple social and health reasons were given for weaning the child, with 87·6 % of mothers who had stopped breast-feeding completely doing so within 3 months postpartum. Nationality (P<0·001), employment status 6 months prior to delivery (P<0·001), mode of delivery (P=0·01), sex of the child (P=0·026) and breast-feeding information given by nurses (P=0·026) were all found to be significantly associated with breast-feeding. Few women (5·6 %) got information on infant nutrition and feeding from nursing staff, but those who did were 2·54 times more likely to be still breast-feeding at discharge from hospital. Over 70 % of mothers had enjoyed breast-feeding and 74 % said they would be very likely to breast-feed again. CONCLUSIONS: In Kuwait where the prevalence of both obesity and type 2 diabetes is growing rapidly, the public health role of breast-feeding must be recognised and acted upon more than it has in the past.

Effects of different spawning agents on serum levels of reproductive steroid hormones and cortisol level in adult female Barbus sharpeyi (Gunther, 1874).

The question of whether, as hormone therapies, spawning agents differ from each other to induce physiological pathways of gametogenesis and oocyte maturation in fish remains important, because it could modify undesirable changes, regulated by endocrine systems of individual fish. A series of experimental treatments were applied to investigate the underlying mechanism(s) in which female bunnei (Barbus sharpeyi) fish respond differently to hormone therapies. Female broodstocks were injected twice (with 12 h interval) by three different treatments namely A, B and C. The treatment A received carp pituitary extract (CPE) + luteinizing hormone-releasing hormone analogs (LHRHα2) (0.5 mg CPE kg(-1) BW for first injection and 2 mg CPE kg(-1) BW + 10 µg LHRHα2 kg(-1) for second injection), treatment B received CPE (0.5 and 3.5 mg kg(-1) BW), and treatment C received ovaprim (0.1 and 0.15 ml kg(-1) BW). Blood samples were collected at four different time intervals, including prior to injections, 6 h after first injection, 6 h after second injection and at the time of spawning, and serum steroid hormones, including testosterone, progesterone and estradiol-17ß as well as cortisol, were measured. Results showed significant increases in serum estradiol-17ß following all treatments, but the most profound response was found in treatments A and B. Testosterone was higher in larger broodfish than in small-sized broodfish (>1.5 vs. <1.5 kg) in all treatments. CPE led to higher concentration of testosterone rather than two other treatments. CPE also increases the progesterone following first injection and approximately remains unchanged till the end of experiment. Change in progesterone level was only significant after second injection of ovaprim as well as after spawning compared with previous time. Linear regression analyses indicated that cortisol had adverse effects on progesterone and testosterone levels of weight group <1.5 kg. These results suggest that among inducing agents, applied here, CPE can provide more reasonable response in reproduction of female B. sharpeyi.

The potential of o-bromo-trans-decalinvesamicol as a new PET ligand for vesicular acetylcholine transporter imaging.

We investigated the characteristics of the regional rat brain distribution of radio-brominated o-bromo-decalinvesamicol (OBDV) in vivo to evaluate its potential as a PET ligand for vesicular acetylcholine transporter (VAChT). In in vivo biodistribution study, the specific brain regional accumulation of [(77) Br]OBDV was revealed 30 min after intravenous injection. The specific brain regional accumulation of [(77) Br]OBDV was significantly inhibited by co-injection of (+/-)-vesamicol. In contrast, no significant inhibition of the uptake of [(77) Br]OBDV in all brain regions was observed with co-injection of (+)-pentazocine (selective σ-1 receptor agonist) and (+)-3-(3-hydroxyphenyl)-N-propylpiperidine, [(+)-3-PPP] (σ-1 and σ-2 receptor agonist) with [(77) Br]OBDV. [(77) Br]OBDV accumulation in VAChT-rich brain regions was observed in ex vivo autoradiography. These results showed that [(77) Br]OBDV selectively bound to VAChT with high affinity in rat brain in vivo. Hence, OVBDV radiolabelled with more suitable (76) Br was suggested to be a potent VAChT ligand for PET.