The yeast AMP-activated protein kinase Snf1 phosphorylates the inositol polyphosphate kinase Kcs1.

The yeast Snf1/AMP-activated kinase (AMPK) maintains energy homeostasis, controlling metabolic processes and glucose derepression in response to nutrient levels and environmental cues. Under conditions of nitrogen or glucose limitation, Snf1 regulates pseudohyphal growth, a morphological transition characterized by the formation of extended multicellular filaments. During pseudohyphal growth, Snf1 is required for wild-type levels of inositol polyphosphate (InsP), soluble phosphorylated species of the six-carbon cyclitol inositol that function as conserved metabolic second messengers. InsP levels are established through the activity of a family of inositol kinases, including the yeast inositol polyphosphate kinase Kcs1, which principally generates pyrophosphorylated InsP7. Here, we report that Snf1 regulates Kcs1, affecting Kcs1 phosphorylation and inositol kinase activity. A snf1 kinase-defective mutant exhibits decreased Kcs1 phosphorylation, and Kcs1 is phosphorylated in vivo at Ser residues 537 and 646 during pseudohyphal growth. By in vitro analysis, Snf1 directly phosphorylates Kcs1, predominantly at amino acids 537 and 646. A yeast strain carrying kcs1 encoding Ser-to-Ala point mutations at these residues (kcs1-S537A,S646A) shows elevated levels of pyrophosphorylated InsP7, comparable to InsP7 levels observed upon deletion of SNF1. The kcs1-S537A,S646A mutant exhibits decreased pseudohyphal growth, invasive growth, and cell elongation. Transcriptional profiling indicates extensive perturbation of metabolic pathways in kcs1-S537A,S646A. Growth of kcs1-S537A,S646A is affected on medium containing sucrose and antimycin A, consistent with decreased Snf1p signaling. This work identifies Snf1 phosphorylation of Kcs1, collectively highlighting the interconnectedness of AMPK activity and InsP signaling in coordinating nutrient availability, energy homoeostasis, and cell growth.

Frequency of DNA end joining in trans is not determined by the predamage spatial proximity of double-strand breaks in yeast.

DNA double-strand breaks (DSBs) are serious genomic insults that can lead to chromosomal rearrangements if repaired incorrectly. To gain insight into the nuclear mechanisms contributing to these rearrangements, we developed an assay in yeast to measure cis (same site) vs. trans (different site) repair for the majority process of precise nonhomologous end joining (NHEJ). In the assay, the HO endonuclease gene is placed between two HO cut sites such that HO expression is self-terminated upon induction. We further placed an additional cut site in various genomic loci such that NHEJ in trans led to expression of a LEU2 reporter gene. Consistent with prior reports, cis NHEJ was more efficient than trans NHEJ. However, unlike homologous recombination, where spatial distance between a single DSB and donor locus was previously shown to correlate with repair efficiency, trans NHEJ frequency remained essentially constant regardless of the position of the two DSB loci, even when they were on the same chromosome or when two trans repair events were put in competition. Repair of similar DSBs via single-strand annealing of short terminal direct repeats showed substantially higher repair efficiency and trans repair frequency, but still without a strong correlation of trans repair to genomic position. Our results support a model in which yeast cells mobilize, and perhaps compartmentalize, multiple DSBs in a manner that no longer reflects the predamage position of two broken loci.

Double-strand breaks in motion: implications for chromosomal rearrangement.

DNA double-strand breaks (DSBs) must be rejoined properly to prevent the occurrence of serious genomic rearrangements associated with many human diseases. Non-homologous end joining (NHEJ) is a DSB repair mechanism known to protect genomic integrity that is also implicated in creating genomic translocations, inversions, deletions, and insertions. We recently investigated the impact of the pre-damage spatial proximity of DSB-bearing loci on the frequency of trans repair by NHEJ and surprisingly found no correlation between them. In this review, we consider various models that might account for these unexpected results. While DSB movement is necessary to explain our findings, many questions remain about the nature and timing of that motion.

Overhang polarity of chromosomal double-strand breaks impacts kinetics and fidelity of yeast non-homologous end joining.

Non-homologous end joining (NHEJ) is the main repair pathway for DNA double-strand breaks (DSBs) in cells with limited 5' resection. To better understand how overhang polarity of chromosomal DSBs affects NHEJ, we made site-specific 5'-overhanging DSBs (5' DSBs) in yeast using an optimized zinc finger nuclease at an efficiency that approached HO-induced 3' DSB formation. When controlled for the extent of DSB formation, repair monitoring suggested that chromosomal 5' DSBs were rejoined more efficiently than 3' DSBs, consistent with a robust recruitment of NHEJ proteins to 5' DSBs. Ligation-mediated qPCR revealed that Mre11-Rad50-Xrs2 rapidly modified 5' DSBs and facilitated protection of 3' DSBs, likely through recognition of overhang polarity by the Mre11 nuclease. Next-generation sequencing revealed that NHEJ at 5' DSBs had a higher mutation frequency, and validated the differential requirement of Pol4 polymerase at 3' and 5' DSBs. The end processing enzyme Tdp1 did not impact joining fidelity at chromosomal 5' DSBs as in previous plasmid studies, although Tdp1 was recruited to only 5' DSBs in a Ku-independent manner. These results suggest distinct DSB handling based on overhang polarity that impacts NHEJ kinetics and fidelity through differential recruitment and action of DSB modifying enzymes.

A prospective, multi-centre, observational study to examine kidney disease progression in adults with chronic kidney disease - CKDOD - Study design and preliminary results.

BACKGROUND: The objective of this article is to describe the organisation of an international, clinical registry, the Chronic Kidney Disease Observational Database (CKDOD), the processes of enrolling patients and entering data and preliminary results to date. DESIGN: The Chronic Kidney Disease Observational Database (CKDOD) is designed to assess the association between different factors with a known influence on chronic kidney disease (CKD) progression as well as treatment strategies such as dietary modifications, blood pressure control and pharmacological interventions in Asian countries (India, China, Malaysia and Thailand). The only inclusion criterion is the presence of CKD stage 2 or higher as defined by the KDIGO guidelines. Demographic and clinical information are collected by a standardised electronic questionnaire, available in English and Chinese. The data are transferred to the CKDOD database either by e-mail or via web access. All data are checked for consistency and missing values. Collection of data started in September 2011 and by April 2015, data on 1323 individual patients had been submitted. The mean age at inclusion was 57 ± 14 years, 67 % were male and 36 % were diabetic. The baseline estimated glomerular filtration rate was 26 ml/min/1.73 m(2). Of all enrolled patients, 324 (24 %) received ketoanalogue supplementation during at least one recorded visit. DISCUSSION: The CKDOD is a very large and comprehensive data repository, currently focused in subjects recruited from Asia. The database is expected to provide important long-term information on CKD progression, nutritional and metabolic derangements that accompany CKD progression and treatment strategies to ameliorate progression and complications of CKD. TRIAL REGISTRATION: Clinical Trial Registry - India: CTRI/2012/06/002743 ; 25th July 2012.

A dominant role for meiosis-specific 3' RNA processing in controlling expression of a fission yeast cyclin gene.

Meiotic gene regulation provides a rich source of insight into mechanisms of temporal control during development. We previously reported that accumulation of many meiotic mRNAs in fission yeast is governed by changes in 3' RNA processing and elucidated the molecular basis of this regulatory mechanism for an early meiotic gene. Here, we report that cleavage/polyadenylation is also the nexus of negative control for middle meiotic genes. Parallel profiles of splicing and polyadenylation are observed over a meiotic time course for both rem1 and spo4 but not for a constitutive control gene. Nevertheless, polyadenylation of rem1 transcripts is restricted to meiosis by a splicing-independent mechanism. Through systematic sequence substitutions, we identified a negative control region (NCR) located upstream of the rem1 transcription start site and found that it is required to block 3' RNA processing in proliferating cells. Ablation of the NCR relieves inhibition regardless of whether the intron is present, absent, or carries splice site mutations. Consistent with the previous report of a polypeptide encoded by the first exon of rem1, we discovered a second 3' processing site just downstream from the 5' splice site. Polyadenylation within the intron is activated concurrent with the downstream site during meiosis, is controlled by the NCR, and is enhanced when splicing is blocked via 5' junction or branch point mutations. Taken together, these data suggest a novel regulatory mechanism in which a 5' element modulates the dynamic interplay between splicing and polyadenylation.

Burden and predictors of hypertension in India: results of SEEK (Screening and Early Evaluation of Kidney Disease) study.

BACKGROUND: Hypertension (HTN) is one of the major causes of cardiovascular morbidity and mortality. The objective of the study was to investigate the burden and predictors of HTN in India. METHODS: 6120 subjects participated in the Screening and Early Evaluation of Kidney disease (SEEK), a community-based screening program in 53 camps in 13 representative geographic locations in India. Of these, 5929 had recorded blood pressure (BP) measurements. Potential predictors of HTN were collected using a structured questionnaire for SEEK study. RESULTS: HTN was observed in 43.5% of our cohort. After adjusting for center variation (p < 0.0001), predictors of a higher prevalence of HTN were older age ≥ 40 years (p < 0.0001), BMI of ≥ 23 Kg/M2 (p < 0.0004), larger waist circumference (p < 0.0001), working in sedentary occupation (p < 0.0001), having diabetes mellitus (p < 0.0001), having proteinuria (p < 0.0016), and increased serum creatinine (p < 0.0001). High school/some college education (p = 0.0016), versus less than 9th grade education, was related with lower prevalence of HTN. Of note, proteinuria and CKD were observed in 19% and 23.5% of HTN subjects. About half (54%) of the hypertensive subjects were aware of their hypertension status. CONCLUSIONS: HTN was common in this cohort from India. Older age, BMI ≥ 23 Kg/M2, waist circumference, sedentary occupation, education less, diabetes mellitus, presence of proteinuria, and raised serum creatinine were significant predictors of hypertension. Our data suggest that HTN is a major public health problem in India with low awareness, and requires aggressive community-based screening and education to improve health.

Fluoride export is required for the competitive fitness of pathogenic microorganisms in dental biofilm models.

Microorganisms resist fluoride toxicity using fluoride export proteins from one of several different molecular families. Cariogenic species Streptococcus mutans and Candida albicans extrude intracellular fluoride using a CLCF F-/H+ antiporter and FEX fluoride channel, respectively, whereas oral commensal eubacteria, such as Streptococcus gordonii, export fluoride using a Fluc fluoride channel. In this work, we examine how genetic knockout of fluoride export impacts pathogen fitness in single-species and three-species dental biofilm models. For biofilms generated using S. mutans with the genetic knockout of the CLCF transporter, exposure to low fluoride concentrations decreased S. mutans counts, synergistically reduced the populations of C. albicans, increased the relative proportion of oral commensal S. gordonii, and reduced properties associated with biofilm pathogenicity, including acid production and hydroxyapatite dissolution. Biofilms prepared with C. albicans with genetic knockout of the FEX channel also exhibited reduced fitness in the presence of fluoride but to a lesser degree. Imaging studies indicate that S. mutans is highly sensitive to fluoride, with the knockout strain undergoing complete lysis when exposed to low fluoride for a moderate amount of time. Biochemical purification of the S. mutans CLCF transporter and functional reconstitution establishes that the functional protein is a dimer encoded by a single gene. Together, these findings suggest that fluoride export by oral pathogens can be targeted by specific inhibitors to restore biofilm symbiosis in dental biofilms and that S. mutans is especially susceptible to fluoride toxicity. IMPORTANCE: Dental caries is a globally prevalent condition that occurs when pathogenic species, including Streptococcus mutans and Candida albicans, outcompete beneficial species, such as Streptococcus gordonii, in the dental biofilm. Fluoride is routinely used in oral hygiene to prevent dental caries. Fluoride also has antimicrobial properties, although most microbes possess fluoride exporters to resist its toxicity. This work shows that sensitization of cariogenic species S. mutans and C. albicans to fluoride by genetic knockout of fluoride exporters alters the microbial composition and pathogenic properties of dental biofilms. These results suggest that the development of drugs that inhibit fluoride exporters could potentiate the anticaries effect of fluoride in over-the-counter products like toothpaste and mouth rinses. This is a novel strategy to treat dental caries.

Fluoride export is required for competitive fitness of pathogenic microorganisms in dental biofilm models.

Microorganisms resist fluoride toxicity using fluoride export proteins from one of several different molecular families. Cariogenic species Streptococcus mutans and Candida albicans extrude intracellular fluoride using a CLCF F-/H+ antiporter and FEX fluoride channel, respectively, whereas commensal eubacteria, such as Streptococcus gordonii, export fluoride using a Fluc fluoride channel. In this work, we examine how genetic knockout of fluoride export impacts pathogen fitness in single-species and three-species dental biofilm models. For biofilms generated using S. mutans with genetic knockout of the CLCF transporter, exposure to low fluoride concentrations decreased S. mutans counts, synergistically reduced the populations of C. albicans, increased the relative proportion of commensal S. gordonii, and reduced properties associated with biofilm pathogenicity, including acid production and hydroxyapatite dissolution. Biofilms prepared with C. albicans with genetic knockout of the FEX channel also exhibited reduced fitness in the presence of fluoride, but to a lesser degree. Imaging studies indicate that S. mutans is highly sensitive to fluoride, with the knockout strain undergoing complete lysis when exposed to low fluoride for a moderate amount of time, and biochemical purification the S. mutans CLCF transporter and functional reconstitution establishes that the functional protein is a dimer encoded by a single gene. Together, these findings suggest that fluoride export by oral pathogens can be targeted by specific inhibitors to restore biofilm symbiosis in dental biofilms, and that S. mutans is especially susceptible to fluoride toxicity.

Epidemiology and risk factors of chronic kidney disease in India - results from the SEEK (Screening and Early Evaluation of Kidney Disease) study.

BACKGROUND: There is a rising incidence of chronic kidney disease that is likely to pose major problems for both healthcare and the economy in future years. In India, it has been recently estimated that the age-adjusted incidence rate of ESRD to be 229 per million population (pmp), and >100,000 new patients enter renal replacement programs annually. METHODS: We cross-sectionally screened 6120 Indian subjects from 13 academic and private medical centers all over India. We obtained personal and medical history data through a specifically designed questionnaire. Blood and urine samples were collected. RESULTS: The total cohort included in this analysis is 5588 subjects. The mean ± SD age of all participants was 45.22 ± 15.2 years (range 18-98 years) and 55.1% of them were males and 44.9% were females. The overall prevalence of CKD in the SEEK-India cohort was 17.2% with a mean eGFR of 84.27 ± 76.46 versus 116.94 ± 44.65 mL/min/1.73 m2 in non-CKD group while 79.5% in the CKD group had proteinuria. Prevalence of CKD stages 1, 2, 3, 4 and 5 was 7%, 4.3%, 4.3%, 0.8% and 0.8%, respectively. CONCLUSION: The prevalence of CKD was observed to be 17.2% with ~6% have CKD stage 3 or worse. CKD risk factors were similar to those reported in earlier studies.It should be stressed to all primary care physicians taking care of hypertensive and diabetic patients to screen for early kidney damage. Early intervention may retard the progression of kidney disease. Planning for the preventive health policies and allocation of more resources for the treatment of CKD/ESRD patients are imperative in India.

A new method to efficiently induce a site-specific double-strand break in the fission yeast Schizosaccharomyces pombe.

Double-strand DNA breaks are a serious threat to cellular viability and yeast systems have proved invaluable in helping to understand how these potentially toxic lesions are sensed and repaired. An important method to study the processing of DNA breaks in the budding yeast Saccharomyces cerevisiae is to introduce a unique double-strand break into the genome by regulating the expression of the site-specific HO endonuclease with a galactose inducible promoter. Variations of the HO site-specific DSB assay have been adapted to many organisms, but the methodology has seen only limited use in the fission yeast Schizosaccharomyces pombe because of the lack of a promoter capable of inducing endonuclease expression on a relatively short time scale (~1 h). We have overcome this limitation by developing a new assay in which expression of the homing endonuclease I-PpoI is tightly regulated with a tetracycline-inducible promoter. We show that induction of the I-PpoI endonuclease produces rapid cutting of a defined cleavage site (> 80% after 1 h), efficient cell cycle arrest and significant accumulation of the checkpoint protein Crb2 at break-adjacent regions in a manner that is analogous to published findings with DSBs produced by an acute exposure to ionizing irradiation. This assay provides an important new tool for the fission yeast community and, because many aspects of mammalian chromatin organization have been well-conserved in Sz. pombe but not in S. cerevisiae, also offers an attractive system to decipher the role of chromatin structure in modulating the repair of double-stranded DNA breaks.

Streeter's Syndrome of Lower Limb Associated with CTEV.

Introduction: The term Streeter's syndrome is a term used to describe rare congenital malformations that includes a variety of clinical presentations usually consisting of a constriction band around a part of the body which can be as superficial as involving just the skin which can be only cosmetic and asymptomatic or can be as deep as causing restricted circulation distally which may be in incompatible with life. Such conditions are remarkably rare accounting for an incidence range from 1:1.2 k to 1: 15 k live births and 178:10 k spontaneous abortions [1]. Males and females are uniformly affected. Almost all cases are sporadic; extremely rare evidence of familial transmission. The entity has been described in the literature in 34 different terms, (such as amniotic rupture sequence, ADAM complex, constriction band syndrome, Streeter's dysplasia, etc.) due to its extremely variable clinical features and lack of understanding of the etiology. This results in a lack of understanding and creates unnecessary stress for the surgeon/physician as well as the parents. Case Report: We discuss case reports of two such cases with their simple nature of treatment with their outcomes. Conclusion: There is a significant deficit in the education of cases with low incidence, such is the case with pediatric patients presenting with amniotic bands, which usually present and are associated with Congenital Talipes Equino Varus deformity. In such cases, improper or incorrect treatment and/or neglect of the constriction may lead to the vascular deficit and eventually auto-amputation of the segment distal to the amniotic band.

Prevalence of Vascular Calcification in Chronic Kidney Disease Stage 4 and 5 Patients and its Correlation with Inflammatory Markers of Atherosclerosis.

Vascular calcification is one of the independent risk factors associated with cardiovascular disease (CVD) in chronic kidney disease (CKD) patients. This study evaluated the prevalence of vascular calcification in Indian patients with CKD stages 4 and 5. This was a prospective study conducted between January 2011 and June 2012. CKD stage 4 and 5 patients of either sex aged >18 years were screened for aortic vascular calcification using digital X-ray lumbar spine and multislice computed tomography (CT) scan. In addition, details of inflammatory markers [high-sensitivity C-reactive protein (hs-CRP) and interleukin (IL-6)] were also collected. A total of 150 patients (stage 4, n = 98; stage 5, n = 56) were screened for vascular calcification, and the mean age was 56.56 years. Patients with CKD stage 5 had significantly higher (P ≤0.05) serum creatinine and lower estimated glomerular filtration rate, total cholesterol, and low-density lipoprotein than CKD stage 4. Significantly, more patients with CKD stage 5 had a history of CVD. A total of 113 (75.3%) patients had vascular calcification [aortic calcification index (ACI) >0] with significantly higher prevalence in CKD stage 5 (85.72%) as compared to CKD stage 4 (69.15%). Patients having high aortic calcification (ACI >20%) were older (P = 0.0013); had a higher frequency of diabetes, and CVD; and had significantly (P <0.05) higher blood urea, serum creatinine, phosphorus, Ca × PO4 product, intact parathyroid hormone, hs-CRP, and IL-6. The higher CKD stage was associated with a higher prevalence of vascular calcification and higher aortic calcification index (ACI). CT techniques (electron beam CT and multislice CT) are the gold standards for detection and quantification of progression of vascular calcification.

Isolation of 4-aminopyridine resistant mutants affecting alkali-insoluble glucan content of cell walls in Saccharomyces cerevisiae.

Saccharomyces cerevisiae cells when grown on synthetic medium plates containing 10 mM of 4-aminopyridine (4-AP) undergo cell lysis. Using an ethylmethane sulfonate mutagenesis (EMS) screen, 4-AP resistant mutants (apr) were isolated which could grow on inhibitory concentration of 4-AP. Eighty mutants were obtained that were recessive, monogenic and formed two complementation groups. To identify genes, whose products might be interacting with the apr loci, extragenic suppressors were isolated, which reverted 4-AP resistance phenotype of apr mutants. The suppressors, when genetically characterized, were found to be recessive and represented two loci with overlapping functions. Representative alleles from apr mutants were analyzed for cell wall composition. They were found to have a higher amount of alkali-insoluble glucan signifying the role of alkali-insoluble glucan in cell wall maintenance.

A rare case of type-I auto-immune hepatitis and thyroiditis presenting with crescentic glomerulonephritis.

A middle-aged female patient with a past history of non-alcoholic liver disease and hypothyroidism presented with swelling of the body, off and on, for six months and rapidly worsening renal function. Renal biopsy showed crescentic glomerulonephritis with negative immunofluorescence. Serological tests were positive for anti-thyroglobulin, anti-nuclear antibody (1:80), p-anti-neutrophil cytoplasmic antibodies; gamma globulin was 5.23 g/dL and viral markers were negative. The patient was diagnosed to have autoimmune hepatitis type-1 and treated with injection methylprednisolone pulse (500 mg/day for 3 days) and maintained on oral steroids and azathioprine 100 mg. She responded dramatically to this treatment and has remained in complete remission at last follow-up.

Unusual metastatic presentation of carcinoma hypopharynx.

Cutaneous metastases from hypopharyngeal cancers is rare constituting about 0.8-1.3% and represent a sub-group of head and neck cancer patients who have very poor prognosis even when treated. We report a case of 65-year-old male diagnosed as carcinoma hypo pharynx stage IV who was on radiotherapy when he developed cutaneous metastasis over the chest wall, which initially presented as small nodules and later progressed into a proliferative lesion. Patient received further radiation to the metastatic lesion, but the disease was progressive, demonstrating that head and neck squamous cell cancer patients with skin metastasis fare poorly.

Autophosphorylation of the Smk1 MAPK is spatially and temporally regulated by Ssp2 during meiotic development in yeast.

Smk1 is a meiosis-specific MAPK that controls spore wall morphogenesis in Saccharomyces cerevisiae. Although Smk1 is activated by phosphorylation of the threonine (T) and tyrosine (Y) in its activation loop, it is not phosphorylated by a dual-specificity MAPK kinase. Instead, the T is phosphorylated by the cyclin-dependent kinase (CDK)-activating kinase, Cak1. The Y is autophosphorylated in an intramolecular reaction that requires a meiosis-specific protein named Ssp2. The meiosis-specific CDK-like kinase, Ime2, was previously shown to positively regulate Smk1. Here we show that Ime2 activity is required to induce the translation of SSP2 mRNA at anaphase II. Ssp2 protein is then localized to the prospore membrane, the structure where spore wall assembly takes place. Next the carboxy-terminal portion of Ssp2 forms a complex with Smk1 and stimulates the autophosphorylation of its activation-loop Y residue. These findings link Ime2 to Smk1 activation through Ssp2 and define a developmentally regulated mechanism for activating MAPK at specific locations in the cell.

Evaluation of Protein-Energy Wasting and Inflammation on Patients Undergoing Continuous Ambulatory Peritoneal Dialysis and its Correlations.

BACKGROUND: Protein-energy wasting (PEW) and heightened inflammation are prevalent in patients undergoing continuous ambulatory peritoneal dialysis (CAPD) and is a strong risk factor for morbidity and mortality in these patients. Evaluation of PEW, prevalence of inflammation as well as interrelationship between various nutritional indices and inflammation has not been studied in much detail in patients undergoing CAPD. OBJECTIVES: This study was conducted to evaluate the interrelationship between PEW and inflammation in patients undergoing CAPD. PATIENTS AND METHODS: Sixty-three patients undergoing CAPD (M = 28, F = 35) were assessed with regard to their nutritional status and inflammation after a minimum of 3 months CAPD initiation. Nutritional status was assessed by dietary diary, anthropometry, subjective global assessment, and multifrequency bioelectrical impedance analysis (BIA). In addition, their serum albumin, prealbumin, transferrin, and cholesterol level were measured. Also, inflammation in these patients was assessed by High-Sensitivity C-Reactive Protein (hs-CRP > 3 mg/L) and Interleukin-6 (IL-6 > 2 µg/mL). Later on, diagnosis of malnutrition was made based on different methods. Correlation between inflammation and various nutritional assessment indices were analyzed statistically. RESULTS: Mean (SD) age of the patients was 57.6 (11.6) years. The average (SD) calorie and protein intake per day were 25.5 (4.6) kcal and 0.81 (0.2) mg, respectively. The mean and standard deviation of anthropometry variables of body mass index (BMI), mid-arm circumference (MAC), tricipital skin-fold thickness (TST), mid-arm muscle circumference (MAMC), and corrected mid-arm muscle area (cMAMA) were 23.7 ± 5 kg/m(2), 26.3 ± 4.5 cm, 1.624 ± 0.4 cm, 25.6 ± 4.5 cm, and 45.7 ± 19.7 cm(2), respectively. The mean values of serum protein, albumin, prealbumin, transferrin, cholesterol, triglyceride, hs-CRP, and IL-6 were 5.9 g/dL, 3.0 g/dL, 21.11 mg/dL, 130.6 mg/dL, 155.9 mg/dL, 136.1 mg/dL, 8.8 ± 7.6 mg/L, and 8.4 ± 12.2 µg/dL, respectively. Based on subjective global assessment (SGA); 11.63 (17.4%), 34.63 (54%), and 18.65 (28.6%) patients undergoing CAPD had normal, moderate, and severe malnutrition status, respectively. According to serum albumin level; 13.63 (21%), 39.63 (62%), and 11.63 (17%) patients undergoing CAPD had normal, moderate, and severe malnutrition status, respectively. Finally, based on BMI; 33.63 (52%), 23.63 (37%), and 7.63 (11%) patients undergoing CAPD had normal, moderate, and severe malnutrition status, respectively. About 76.1% and 9.5% of patients undergoing CAPD were malnourished based on lean tissue index (LTI) and fat tissue index (FTI), respectively. Based on hs-CRP and IL-6 findings, 70% (44/63) and 71.8% (45/63) of patients undergoing CAPD had high inflammation, respectively. High sensitive C-reactive protein correlated negatively (significantly) with serum albumin, prealbumin, and transferrin. Interleukin -6 correlated negatively (significantly) with MAC; MAMA; serum albumin, cholesterol, and transferrin. There was significant positive correlation between hs-CRP and IL-6. There is statistically significant difference in total protein intake (g/d), protein intake (g/kg/d), serum protein (g/dL), albumin (g/dL), transferrin (mg/dL), and cholesterol (mg/dL) between patients with and without inflammation. CONCLUSIONS: Protein-energy wasting (80% - 85%) by various methods and inflammation (70%) was very prevalent among patients undergoing CAPD. Inflammatory markers show significant negative correlation with anthropometry and serological markers. Inflammatory markers are suggested to be included in the regular assessment of patients undergoing CAPD, for the better management of protein-energy wasting.

Chronic peritoneal dialysis in the tenth decade of life.

In this retrospective study we present our experience with chronic peritoneal dialysis in nine patients with ESRD in their 10th decade of life (> or =90 years) at the Toronto Western Hospital. A family member or a private nurse assisted all patients in dialysis procedure. The co-morbid illnesses, survival, hospitalizations and complications related or unrelated to peritoneal dialysis were reviewed. Four patients started dialysis before and five after their 90th birthday, their mean age was 90.61+/-4.04 years. All patients had three or more co-morbid illnesses at the start of dialysis. Total duration of PD treatment was 210 patient months with a median duration of 25 months (range 4-68 months). Of the nine patients, four died after a mean follow up of 38.5 months on dialysis. Of the remaining five, one was transferred to hemodialysis after remaining for 10 months on peritoneal dialysis and the other four are continuing on PD for a mean duration of 9.25 months. Peritonitis (1/13.4 patient months) and exit site infection (1/100.5 patient months) responded to treatment. Hospitalization rate was one admission per 2.5 patient years. Most often, the cause of hospitalization was unrelated to PD, e.g., cardiovascular events, pneumonia and peripheral vascular disease etc. Patient survival at 1, 3 and 5 years was 88%, 58% and 24% respectively. The technique survival was 69%, 47% and 23% at 1, 3 and 5 years respectively. We conclude that continuous peritoneal dialysis is a safe and suitable treatment even in nonagenarians (> or =90 years) ESRD patients.

Yeast DNA ligase IV mutations reveal a nonhomologous end joining function of BRCT1 distinct from XRCC4/Lif1 binding.

LIG4/Dnl4 is the DNA ligase that (re)joins DNA double-strand breaks (DSBs) via nonhomologous end joining (NHEJ), an activity supported by binding of its tandem BRCT domains to the ligase accessory protein XRCC4/Lif1. We screened a panel of 88 distinct ligase mutants to explore the structure­function relationships of the yeast Dnl4 BRCT domains and inter-BRCT linker in NHEJ. Screen results suggested two distinct classes of BRCT mutations with differential effects on Lif1 interaction as compared to NHEJ completion. Validated constructs confirmed that D800K and GG(868:869)AA mutations, which target the Lif1 binding interface, showed a severely defective Dnl4­Lif1 interaction but a less consistent and often small decrease in NHEJ activity in some assays, as well as nearly normal levels of Dnl4 accumulation at DSBs. In contrast, mutants K742A and KTT(742:744)ATA, which target the ß3-α2 region of the first BRCT domain, substantially decreased NHEJ function commensurate with a large defect in Dnl4 recruitment to DSBs, despite a comparatively greater preservation of the Lif1 interaction. Together, these separation-of-function mutants indicate that Dnl4 BRCT1 supports DSB recruitment and NHEJ in a manner distinct from Lif1 binding and reveal a complexity of Dnl4 BRCT domain functions in support of stable DSB association.