Mapping of the seed storage protein locus Sec-2 in rye

The segregation of the 75K gamma secalin locus (Sec-2) in combination with five interchanges (reciprocal translocations) and two marker genes was analyzed. The translocations involved chromosome arms 1RL, 1RS, 2RL, 2RS, 4RL, 5RL, 5RS, 6RL and 6RS. The gene loci were both on 2R, but the arm was not known. Although the Sec-2 locus was expected to be on chromosome 2RS, no linkage between Sec-2 and any of the markers was found. This is concluded to be the result of exceptionally frequent recombination between Sec-2 and the break point of one of the translocations, which is the only marker in 2RS.     

Bacterial programmed cell death and multicellular behavior in bacteria

Traditionally, programmed cell death (PCD) is associated with eukaryotic multicellular organisms. However, recently, PCD systems have also been observed in bacteria. Here we review recent research on two kinds of genetic programs that promote bacterial cell death. The first is mediated by mazEF, a toxin–antitoxin module found in the chromosomes of many kinds of bacteria, and mainly studied in Escherichia coli. The second program is found in Bacillus subtilis, in which the skf and sdp operons mediate the death of a subpopulation of sporulating bacterial cells. We relate these two bacterial PCD systems to the ways in which bacterial populations resemble multicellular organisms.     

Altered expression of tyrosine kinases of the Src and Syk families in human T-cell leukemia virus type 1-infected T-cell lines

During the late phase of adult T-cell leukemia/lymphoma, a severe lymphoproliferative disorder caused by human T-cell leukemia virus type 1 (HTLV-1), leukemic cells no longer produce interleukin-2. Several studies have reported the lack of the Src-like protein tyrosine kinase Lck and overexpression of Lyn and Fyn in these cells. In this report we demonstrate that, in addition to the downregulation of TCR, CD45, and Lck (which are key components of T-cell activation), HTLV-1-infected cell lines demonstrate a large increase of FynB, a Fyn isoform usually poorly expressed in T cells. Furthermore, similar to anergic T cells, Fyn is hyperactive in one of these HTLV-1-infected T-cell lines, probably as a consequence of Csk downregulation. A second family of two proteins, Zap-70 and Syk, relay the signal of T-cell activation. We demonstrate that in contrast to uninfected T cells, Zap-70 is absent in HTLV-1-infected T cells, whereas Syk is overexpressed. In searching for the mechanism responsible for FynB overexpression and Zap-70 downregulation, we have investigated the ability of the Tax and Rex proteins to modulate Zap-70 expression and the alternative splicing mechanism which gives rise to either FynB or FynT. By using Jurkat T cells stably transfected with the tax and rex genes or inducibly expressing the tax gene, we found that the expression of Rex was necessary to increase fynB expression, suggesting that Rex controls fyn gene splicing. Conversely, with the same Jurkat clones, we found that the expression of Tax but not Rex could downregulate Zap-70 expression. These results suggest that the effect of Tax and Rex must cooperate to deregulate the pathway of T-cell activation in HTLV-1-infected T cells.     

Screening for Tannin Degradation by Rumen and Faecal Samples of Wild and Domestic Animals in Ethiopia

Summary Tannins limit the use of fodder trees as feed for ruminants. Removal of the effects of tannins would thus improve the nutritional quality of these trees. This prompted the study to evaluate the effect of rumen or faecal mixed cultures from different animals on tannin degradation. Tannin extracts, tannic acid and gallic acid were used to enrich media to assess if rumen or faecal mixed cultures could degrade the phenolic compounds. Rumen fluid of Acacia-adapted sheep, sheep fed on wheat bran, bush duikers (Sylvicapra grimmia) and goats fed on Leucaena pallida and Sesbania goetzei were separately inoculated into Growth Study Medium (GSM) and incubated for 5-15 days. Faecal samples from dikdik (Madoqua guentheri), camel (Camelus dromedarius), zebra (Equus quagga), Grant’s gazelle (Gazella granti) and hartebeest (Alcelaphus buselaphus) were also separately inoculated into GSM media and incubated from 3-5 days. TLC results showed that mixed cultures from rumen fluids of Acacia-adapted sheep, sheep on wheat bran, goats on Leucaena pallida and Sesbania goetzei partially hydrolysed tannic acid to pyrogallol. Complete degradation of the heterocyclic ring in tannic acid and gallic acid was achieved by the mixed cultures from the faecal samples of dikdik and this was confirmed by HPLC. Mixed cultures from faecal samples of camel hydrolysed gallic acid to phloroglucinol. This study has demonstrated that faecal microorganisms of Ethiopian dikdik could completely degrade hydrolysable tannin.     

Laboratory Test Surveillance following Acute Kidney Injury

Background

Patients with hospitalized acute kidney injury (AKI) are at increased risk for accelerated loss of kidney function, morbidity, and mortality. We sought to inform efforts at improving post-AKI outcomes by describing the receipt of renal-specific laboratory test surveillance among a large high-risk cohort.

Methods

We acquired clinical data from the Electronic health record (EHR) of 5 Veterans Affairs (VA) hospitals to identify patients hospitalized with AKI from January 1^st, 2002 to December 31^st, 2009, and followed these patients for 1 year or until death, enrollment in palliative care, or improvement in renal function to estimated GFR (eGFR) ≥60 L/min/1.73 m². Using demographic data, administrative codes, and laboratory test data, we evaluated the receipt and timing of outpatient testing for serum concentrations of creatinine and any as well as quantitative proteinuria recommended for CKD risk stratification. Additionally, we reported the rate of phosphorus and parathyroid hormone (PTH) monitoring recommended for chronic kidney disease (CKD) patients.

Results

A total of 10,955 patients admitted with AKI were discharged with an eGFR<60 mL/min/1.73 m². During outpatient follow-up at 90 and 365 days, respectively, creatinine was measured on 69% and 85% of patients, quantitative proteinuria was measured on 6% and 12% of patients, PTH or phosphorus was measured on 10% and 15% of patients.

Conclusions

Measurement of creatinine was common among all patients following AKI. However, patients with AKI were infrequently monitored with assessments of quantitative proteinuria or mineral metabolism disorder, even for patients with baseline kidney disease.     

The relationship between ER-multivesicular body membrane contacts and the ESCRT machinery

Activated EGFR (epidermal growth factor receptor) undergoes ESCRT (endosomal sorting complex required for transport)-mediated sorting on to ILVs (intraluminal vesicles) of endosomes before degradation in the lysosome. Sorting of endocytosed EGFR on to ILVs removes the catalytic domain of the EGFR from the cytoplasm, resulting in termination of receptor signalling. EGFR signalling is also subject to down-regulation through receptor dephosphorylation by the ER (endoplasmic reticulum)-localized PTP1B (protein tyrosine phosphatase 1B). PTP1B on the cytoplasmic face of the ER interacts with endocytosed EGFR via direct membrane contacts sites between the ER and endosomes. In the present paper, we review the relationship between ER-endosome membrane contact sites and ILV formation, and their potential role in the regulation of EGFR sorting on to ILVs, through PTP1B-mediated dephosphorylation of both EGFR and components of the ESCRT machinery.