Mineral bone disease in maintenance hemodialysis patients: Association with morbidity and mortality

There is a paucity of data on mineral bone disease in maintenance hemodialysis (MHD) patients from India. This retrospective analysis was undertaken on 858 (males: 599; females: 259) patients from two medical centers on MHD from 1998 to 2010. Age, gender, months on dialysis, hours per session of dialysis, hemoglobin, serum calcium, inorganic phosphorus, intact parathyroid hormone (iPTH), urine output, erythropoietin dosage per week, blood sugar, blood pressure, urea reduction rate, gain in fluid and fluid removed per session, serum albumin, alkaline phosphatase, vitamin D level, supplemental vitamin D and use of phosphate binder for therapy were documented. Overall, 191 patients died (22%) during the observation period. There was an 86% patient survival rate at 1 year on dialysis and an overall predicted 3-year survival rate of 78%. A relatively higher iPTH (P = 0.012), a need for vitamin D supplementation (P = 0.003), less hours on dialysis per session (P = 0.046) and a non-vegetarian diet (P = 0.022) were significantly associated with mortality.

An unusual case of recurrent subconjunctival haemorrhage causing yellow-brown discolouration due to haemosiderin deposition

The authors describe an unusual case of striking unilateral yellow-brown discolouration of the conjunctiva in a 33-year-old man. A biopsy from an elevated conjunctival area showed a brown pigmentation to be haemosiderin and haemogranulomatous inflammation most probably due to recurrent subconjunctival haemorrhage.

Reduced sensory gating of the P1 potential in rape victims and combat veterans with posttraumatic stress disorder

The P1 midlatency auditory evoked potential was studied in female rape victims with Posttraumatic Stress Disorder (PTSD) and compared to an age-matched female control group; and in male combat veterans with PTSD and compared to three groups of age-matched male control subjects. Sensory gating of the P1 potential was determined using a paired click stimulus paradigm in which the stimuli were presented at 250, 500 and 1000 msec interstimulus intervals (ISI). Results showed that sensory gating of the P1 potential was significantly decreased at the 250 msec ISI, and that there was a numerical, but not a statistically significant, decrease in sensory gating at the other intervals tested in both male and female PTSD subjects compared to all control groups. Since the P1 potential may be generated, at least in part, by the reticular activating system, dysregulation of sensory processing by elements of this system may be present in PTSD.

Anaesthesia for renal transplantation in sickle cell disease

Sickle cell disease (SCD) is associated with many pathological and functional abnormalities affecting all organ systems. Renal manifestations of SCD may result in end-stage renal disease (ESRD), which can be treated by chronic haemodialysis or renal transplantation. Renal transplantation was successfully performed in a 25-yr-old male with sickle cell beta-thalassaemia and nephrotic syndrome. We present a case report of this patient, a discussion of the renal complications associated with SCD and the perioperative management of a patient with SCD undergoing renal transplantation.

Types of beta-lactamase determined by plasmids in gram-negative bacteria

Two species of beta-lactamase determined by plasmids in enteric bacteria that show some resemblance to TEM enzymes are described. Both are distinct from all other plasmid-mediated beta-lactamases and differ from the TEM beta-lactamases in ability to hydrolyze some substrates, in isoelectric point, in immunological specificity, and in susceptibility to inhibition. One of the enzyme species, mediated by plasmid p453, has been briefly described previously. We have discovered that this beta-lactamase, designated SHV-1, is unique in its response to inhibition by the sulfhydryl group reagent p-chloromercuribenzoate, because the hydrolysis of cephaloridine but not that of benzylpenicillin is affected. This enzyme is found in a variety of plasmid types which were transferred from several bacterial species collected from a wide geographic range. The other enzyme species is novel; only a single plasmid determining this kind of beta-lactamase (designated HMS-1) has been detected.

Properties of the beta-lactamase specified by the Pseudomonas plasmid RPL11

The Pseudomonas plasmid RPL11 specifies a beta-lactamase that has properties distinguishing it from other plasmid-mediated beta-lactamases so far described, although it closely resembles plasmid Rms139 beta-lactamase.

Correlation of serological and biochemical groupings of Yersinia enterocolitica with the beta-lactamases of the strains

The beta-lactamase isoelectric focusing patterns of 37 strains of Yersinia enterocolitica from various serological and biochemical groups were examined. Strains of different serological groups generally had different patterns, but those of serological groups 1, 2, 3 and 9 were identical.

Properties of a transposon conferring resistance to penicillins and streptomycin

R938 carries a transposon (TAbeta) of approximate molecular weight 9.5 Megadaltons (Mdal, 10(6) daltons). This contains genes for a beta lactamase of type TEM-1 and for streptomycin phosphatransferase (SPT). There is a ten-fold difference in the efficiency of transposition in different strains of E. coli K12.

Identification of beta-lactamases by analytical isoelectric focusing: correlation with bacterial taxonomy

beta-Lactamases (EC. 3.5.2.6) can be directly compared by analytical isoelectric focusing. Using this technique, 242 strains from five Gram-positive and 16 Gram-negative genera were examined. A preparation of each strain focused as a single group of bands which did not match the pattern of any R factor-associated beta-lactamase. None of the strains was known to carry an R factor and resistance transfer experiments were unsuccessful. The enzymes studied were therefore thought to be chromosomally mediated. The isoelectric points ranged from 3.9 to 8.7 and were not related to the substrate profiles or other biochemical properties. The chromosomal beta-lactamases appeared to be specific for genus, species and sub-species, and strains that produced identical beta-lactamases had identical bacterial characteristics. Correlation of bacteriological differences with differences in beta-lactamase patterns is discussed with particular reference to strains of Escherichia coli and Klebsiella spp. Since beta-lactamases may be universally produced by bacteria, separation of the enzymes by analytical isoelectric focusing could be used in bacterial taxonomy.

Analytical isoelectric focusing of R factor-determined beta-lactamases: correlation with plasmid compatibility

R factor-determined beta-lactamases have been investigated by analytical isoelectric focusing. The enzymes such as those specified by the R6K and RP4 plasmids (TEM-type enzymes) are notably homogenous in biochemical tests (Hedges et al., 1974), but two subclasses can be distinguished by isoelectric focusing. Three subclasses can be distinguished among the oxacillin-hydrolyzing enzymes, in good agreement with the classification based upon biochemical characteristics (Dale and Smith, 1974). The TEM-type beta-lactamases are promiscuously distributed among plasmids of a wide variety of compatibility groups, whereas the various oxacillin-hydrolyzing enzymes show some degree of correlation with compatibility.

Plasmid-determined beta-lactamase indistinguishable from the chromosomal beta-lactamase of Escherichia coli

A plasmid, derived from a naturally occurring strain of Proteus mirabilis, conferred resistance to cephalosporins, apparently mediated by a beta-lactamase indistinguishable from that determined by the chromosomal gene of Escherichia coli K-12. There was evidence for a recombination event between the wild-type plasmid and a defective F factor (Fsp) in the Escherichia coli K-12 culture in which it was stored.

R-factor mediated beta-lactamase production by Haemophilus influenzae

Production of beta-lactamase by 15 strains of Haemophilus influenzae has been investigated. All the strains produce a constitutive beta-lactamase, which readily hydrolyses penicillin G, ampicillin, and cephaloridine. The beta-lactamase produced by these strains is indistinguishable from the type-IIIa enzyme commonly found in strains of Escherichia coli. The beta-lactamase gene has been transferred from the enzyme-producing strains of Haemophilus to strains of H. parainfluenzae and a strain of E. coli.

Role of lymphocyte activation products (LAP) in cell-mediated immunity. I. Preparation and partial purification of guinea-pig LAP

Partial purification of soluble products of guinea-pig lymphocyte activation (LAP) was undertaken by fractional precipitation with ammonium sulphate, ion-exchange and Sephadex chromatography, and by immune precipitation of inducing antigen and of contaminating serum protein. During these purification steps the activity of macrophage migration-inhibition factor (MIF) was concentrated up to 1300-fold and separated from inducing antigen and serum protein. An endpoint assay was devised for expressing antigen-induced MIF activity of LAP fractions as weights of material giving 30% inhibition of migration (MI₃₀ doses).

MIF activity precipitated between 50% and 80% saturated ammonium sulphate and eluted from DEAE-cellulose at pH 7·9 at intermediate salt concentrations (0·03–0·2 M phosphate). On Sephadex gel filtration MIF activity was concentrated in fractions of molecular weight range 56,000–82,000 with a smaller amount of activity eluting from 20,000–56,000. After immune precipitation of extraneous protein and elution from DEAE-cellulose, LAP material was found to have an MI₃₀ dose of 0·4 μg.

Materials representative of antigen and serum protein-depleted MIF were selected for intralymphatic injection in order to determine whether MIF-rich LAP fractions were able to induce paracortical distension in guinea-pig lymph nodes (see following paper).