The SAGA histone acetyltransferase module targets SMC5/6 to specific genes.

BACKGROUND: Structural Maintenance of Chromosomes (SMC) complexes are molecular machines driving chromatin organization at higher levels. In eukaryotes, three SMC complexes (cohesin, condensin and SMC5/6) play key roles in cohesion, condensation, replication, transcription and DNA repair. Their physical binding to DNA requires accessible chromatin. RESULTS: We performed a genetic screen in fission yeast to identify novel factors required for SMC5/6 binding to DNA. We identified 79 genes of which histone acetyltransferases (HATs) were the most represented. Genetic and phenotypic analyses suggested a particularly strong functional relationship between the SMC5/6 and SAGA complexes. Furthermore, several SMC5/6 subunits physically interacted with SAGA HAT module components Gcn5 and Ada2. As Gcn5-dependent acetylation facilitates the accessibility of chromatin to DNA-repair proteins, we first analysed the formation of DNA-damage-induced SMC5/6 foci in the Δgcn5 mutant. The SMC5/6 foci formed normally in Δgcn5, suggesting SAGA-independent SMC5/6 localization to DNA-damaged sites. Next, we used Nse4-FLAG chromatin-immunoprecipitation (ChIP-seq) analysis in unchallenged cells to assess SMC5/6 distribution. A significant portion of SMC5/6 accumulated within gene regions in wild-type cells, which was reduced in Δgcn5 and Δada2 mutants. The drop in SMC5/6 levels was also observed in gcn5-E191Q acetyltransferase-dead mutant. CONCLUSION: Our data show genetic and physical interactions between SMC5/6 and SAGA complexes. The ChIP-seq analysis suggests that SAGA HAT module targets SMC5/6 to specific gene regions and facilitates their accessibility for SMC5/6 loading.

Molecular Insights into the Architecture of the Human SMC5/6 Complex.

A family of Structural Maintenance of Chromosome (SMC) complexes is essential for key cellular processes ensuring proper cohesion, condensation and replication. They share a common SMC-kleisin architecture allowing them to embrace DNA. In SMC5/6, the NSE1 and NSE3 KITE and NSE4 kleisin subunits form a stable subcomplex that binds DNA and regulates essential processes. In addition, NSE5 and NSE6 subunits associate with the core SMC5/6 complex and recruit it to DNA repair sites. The architecture of the SMC5/6 complex is crucial for its proper functioning, and mutations within the human SMC5/6 subunits result in severe syndromes. Therefore, we aimed to analyze interactions within the human SMC5/6 complex and determine its detailed architecture. Firstly, we analyzed different parts of SMC5/6 by crosslinking and MS/MS analysis. Our data suggested domain arrangements of hNSE1-hNSE3 and orientation of hNSE4 within the hNSE1-hNSE3-hNSE4 subcomplex. The crosslinking and electron microscopic analysis of the SMC5/6 core complex showed its rod-like architecture with juxtaposed hSMC5-hSMC6 arms. Additionally, we observed fully or partially opened hSMC5-hSMC6 shapes with the hNSE1-hNSE3-hNSE4 trimer localized in the SMC head domains. To complete mapping of the human SMC5/6 complex architecture, we analyzed positions of hNSE5-hNSE6 at the hSMC5-hSMC6 arms. We showed that hNSE6 binding to hNSE5 and the coiled-coil arm of hSMC6 is mediated by a conserved FAM178 domain, which we therefore renamed CANIN (Coiled-coil SMC6 And NSE5 INteracting) domain. Interestingly, hNSE6 bound both hSMC5 and hSMC6 arms, suggesting that hNSE6 may lock the arms and regulate the dynamics of the human SMC5/6 complex.

Final results of phase III trial in regionally advanced unresectable non-small cell lung cancer: Radiation Therapy Oncology Group, Eastern Cooperative Oncology Group, and Southwest Oncology Group.

STUDY OBJECTIVES: The purpose of this phase III clinical trial was to test whether chemotherapy followed by radiation therapy resulted in superior survival to either hyperfractionated radiation or standard radiation in surgically unresectable non-small cell lung cancer. DESIGN: Patients were prospectively randomized to 2 months of cisplatin, vinblastine chemotherapy followed by 60 Gy of radiation at 2.0 Gy per fraction or 1.2 Gy per fraction radiation delivered twice daily to a total dose of 69.6 Gy, or 2.0 Gy per fraction of radiation once daily to 60 Gy. Patients were enrolled from January 1989 through January 1992, and followed for a potential minimum period of 5 years. SETTING: This trial was an intergroup National Cancer Institute-funded trial within the Radiation Therapy Oncology Group, the Eastern Cooperative Oncology Group, and the Southwest Oncology Group. PATIENTS: Patients with surgically unresectable non-small cell lung cancer, clinical stage II, IIIA, and IIIB, were required to have a Karnofsky Performance Status of > or = 70 and a weight loss of < 5% for 3 months before study entry. Four hundred ninety patients were registered on trial, of which 458 patients were eligible. CONCLUSION: Overall survival was statistically superior for the patients receiving chemotherapy and radiation vs the other two arms of the study. The twice-daily radiation therapy arm, although better, was not statistically superior in survival for those patients receiving standard radiation. Median survival for standard radiation was 11.4 months; for chemotherapy and irradiation, 13.2 months; and for hyperfractionated irradiation, 12 months. The respective 5-year survivals were 5% for standard radiation therapy, 8% for chemotherapy followed by radiation therapy, and 6% for hyperfractionated irradiation.

[Bioenergetics of liver mitochondria after administration of ramipril in experimental diabetes mellitus]. / Bioenergetika pecenových mitochondrií pri experimentálnom diabetes mellitus po podávaní ramiprilu.

BACKGROUND: Diabetes mellitus represents an intense metabolic strain for the liver. Inhibitors of angiotensin-converting enzymes (ACEI) are drugs of choice in the therapy of hypertension in coincidence with diabetes mellitus. The effect of ACEI is complex. The attention is drawn to the study of metabolic effects of ACEI. OBJECTIVES: The aim of the study was to investigate whether the administration of ramipril affects the levels of glycated hemoglobin and fructoseamine in the blood of rats with insulin-dependent diabetes mellitus (IDDM), and whether bioenergetics of mitochondria in the liver undergo changes. METHODS: In our experiments, we used rats of the Wistar strain. The control group was composed of healthy animals. The experimental groups were formed by rats with IDDM evoked by streptozotocine (45 mg/kg) and rats with IDDM + ramipril (10 mg/KG). Both, insulin MONO-ID in the doses of 6 U/kg administered subcutaneously, and water solution of ramipril administered by gastric probe were applied for the period of 8 weeks. We have assessed blood levels of glucose, glycated hemoglobin, fructoseamine and the concentration of cholesterol and triacylglycerols have been assessed also in the liver. Oxidative phosphorylation in mitochondria of the liver were measured polarographically. RESULTS: In the group with IDDM + ramipril, the glycated haemoglobin (M 6.85 CI 5.7-7.0%) and fructoseamine (M 1.45 CI 1.2-1.6 mmol/l) have significantly dropped in comparison with the group with IDDM glycated haemoglobin (M 8.8 7.7-10.7%) and fructoseamine (M 2.04 CI 1.69-2.4 mmol/l). Ramipril did not affect the concentration of cholesterol and triacylglycerols in the blood and liver in rats with IDDM. Ramipril has positively affected oxidative phosphorylation in mitochondria of the liver in coincidence with IDDM. The group with IDDM + ramipril has yielded an increase in the velocity of oxygen consumption in coincidence with stimulated breathing with ADP, the state 3 (M 107.97 CI 96.78-134.51 n AtO/mg of proteins/min.) and phosphorylation velocity (M 232.67 CI 209.38-284.97 nmolATP/protein/min) in contrast to the group with IDDM: the state 3 (M 76.71 CI 66.81-85.99 nAtO/mg of proteins/min and the velocity of phosphorylation (M 161.84 CI 143.55-189.99 nmol ATP/mg of proteins/min) in coincidence with substrate glutamate. A similar trend is present also in coincidence with FAD succinate substrate. CONCLUSIONS: After the administration of ramipril to rats with IDDM, the indicators have improved, and they express the rate of compensation of diabetes mellitus. An increased capacity of the respiratory chain and an increased origin of energy in mitochondria in the livers of rats with IDDM after administration of ramipril indicates an improvement in the metabolic capacity of the liver. (Tab. 4. Ref. 47.)

[Biochemical and functional study of the liver during treatment of familial hyperlipoproteinemia with Mevacor (lovastatin) and Vasosan S (cholestyramine)]. / Biochemické a funkcné vysetrenie pecene pocas liecby familiárnej hyperlipoproteinémie Mevacorom (lovastatínom) a Vasosanom S (cholestyramínom).

The aim of our study was the biochemical and functional examination of the liver during the therapy of familiar hyperlipoproteinemia by means of MevacorR (lovostatine) in comparison with the treatment by Vasosan S (cholestyramine). We examined 20 patients treated with a daily dose of MevacorR being 20-40 mg and, 18 patients treated with a daily dose of Vasosan S being 16-32 g for the period of 12 weeks. During the therapy the total cholesterol, LDL-cholesterol, HDL-cholesterol, triacylglycerols, hepatic enzymes (AST, ALT, ALP) activity, functional test of the liver, biological half-time of antipyrine (t 1/2 antipyrine) were investigated at the onset and at the end of the study. We discovered that at the end of the treatments by MevacorR and Vasosan S the hypolipidemic effect increased (cholesterol p < 0.001, LDL cholesterol p < 0.001), and there was difference in the effect on HDL-cholesterol and in that on triacylglycerols. During the treatment we discovered that due to both medicaments the liver enzymes activity increased to a different extent. At the beginning of the study the antipyrine biological half-time statistically increased in both investigated groups, namely in comparison with the control group. At the end of the treatments in both groups the antipyrine half-time was prolonged, however not significantly. Prior to long-term therapy by hypolipidemics the authors recommend biochemical and functional examination of the liver. (Tab. 4, Fig. 8, Ref. 7.)

[Vasosan S--a cholestyramine in the treatment of hypercholesterolemia of various etiopathogenesis]. / Vasosan S--cholestyramín v liecbe hypercholesterolémie rôznej etiopatogenézy.

Cholestyramine was used for the first time in the treatment of hypercholesterolaemia by Tenneton in 1960 and it persist in the treatment to the present time. The authors had the opportunity to monitor under clinical conditions the hypolipidaemic action of cholestyramine - the preparation Vasosan (manufactured by AG Chemie, Germany) in the treatment of hypercholesterolaemia of different origin, and also when associated with hypertriacylglycerolaemia. The authors revealed that Vasosan S reduced significantly total cholesterol, LDL cholesterol and apoprotein B even after brief treatment (12 weeks) even when there is also hypertriacylglycerolaemia. The decrease of triacylglycerols is not significant, and the increase of HDL-cholesterol is not significant either. Vasosan does not affect the activity of AST, ALT, ALP and total bilirubin, it is well tolerated and causes few gastrointestinal side-effects which do not call for discontinuation of treatment.

Continuous 500,000-year climate record from vein calcite in devils hole, nevada.

Oxygen-18 (delta(18)O) variations in a 36-centimeter-long core (DH-11) of vein calcite from Devils Hole, Nevada, yield an uninterrupted 500,000-year paleotemperature record that closely mimics all major features in the Vostok (Antarctica) paleotemperature and marine delta(18)O ice-volume records. The chronology for this continental record is based on 21 replicated mass-spectrometric uranium-series dates. Between the middle and latest Pleistocene, the duration of the last four glacial cycles recorded in the calcite increased from 80,000 to 130,000 years; this variation suggests that major climate changes were aperiodic. The timing of specific climatic events indicates that orbitally controlled variations in solar insolation were not a major factor in triggering deglaciations. Interglacial climates lasted about 20,000 years. Collectively, these observations are inconsistent with the Milankovitch hypothesis for the origin of the Pleistocene glacial cycles but they are consistent with the thesis that these cycles originated from internal nonlinear feedbacks within the atmosphere-ice sheet-ocean system.

Two-million-year record of deuterium depletion in great basin ground waters.

Fluid inclusions in uranium series-dated calcitic veins from the southern Great Basin record a reduction of 40 per mil in the deuterium content of ground-water recharge during the Pleistocene. This variation is tentatively attributed to major uplift of the Sierra Nevada Range and the Transverse Ranges during this epoch with attendant increasing orographic depletion of deuterium from inland-bound Pacific storms.

A visual field screening protocol for glaucoma.

In this prospective evaluation of the reliability and efficiency of an optimized visual field screening protocol for glaucoma, we tested 145 eyes (73 patients) with increased intraocular pressures to determine the location of early glaucomatous visual field defects. The field examination, which was used as a control, and protocol testing were performed on a manual Goldmann perimeter using kinetic and suprathreshold static techniques, respectively. Of the 145 eyes tested, kinetic Goldmann perimetry detected 43 eyes with glaucomatous defects. The screening protocol detected 39 defective eyes. There were four false-negative tests and one false-positive test. The false-negative rate of just under 10% was within the range predicted from earlier data. The computer-generated optimal protocols performed as predicted and provided an excellent screening technique for the detection of early glaucomatous visual field defects.

Mathematical optimization of glaucoma visual field screening protocols.

There is potential for significantly shortening the time required for visual field screening protocols by a precise specification of the number, exact location, and sequence of points to be tested. Through statistical and mathematical methods, protocols have been developed for maximizing the probability of detecting at least one visual field defect in a subject who is a risk for early glaucomatous field loss. The mathematical formulation was derived in a generalized manner so that it could be applied to most kinetically or statically determined visual field screening methods.

Effect of glucose on the glucagon response to L-dopa in normal and diabetic subjects.

The effect of an oral dose of 1 gm. L-dopa either without or after a concomitant oral administration of 100 gm. glucose on the plasma level of pancreatic glucagon, plasma immunoreactive insulin (IRI), and plasma growth hormone (GH) was assessed in eight normal and 10 insulin-treated diabetic subjects. In the normal group the stimulatory effect o L-dopa on pancreatic glucagon release was reconfirmed. Moreover, in the diabetics essentially the same plasma glucagon increase after drug administration was found, such a response being inhibited in both groups by glucose. The increase of plasma GH after L-dopa in both healthy persons and diabetics and the inhibition of this response by glucose in healthy subjects was reconfirmed. Furthermore, the same effect of exogenous glucose on the L-dopa induced GH release was observed in diabetics. It may be concluded that glucagon may play a pathogenetic role in the worsening of parkinsonian diabetic patients during the treatment with L-dopa and that diabetic hyperglycemia per se seems to be insufficient for an inhibition of the release of both glucagon and GH AFTer L-dopa.