Isoarenarol,A New Protein Kinase Inhibitor from the Marine Sponge Dysidea arenaria

The novel sesquiterpene hydroquinone isoarenarol (1) and the known compound arenarol (2) were isolated from extracts of the marine sponge Dysidea arenaria Bergquist as part of a search for new protein kinase inhibitors. Both 1 and 2 showed potent and selective protein kinase inhibition in vitro.     

Antioxidant status in rheumatoid arthritis and role of antioxidant therapy

BACKGROUND: Oxygen free radicals have been implicated as mediators of tissue damage in patients of rheumatoid arthritis (RA). This study was designed to elucidate plasma oxidant/antioxidant status in rheumatoid arthritis, with the aim of evaluating the importance of antioxidant therapy in the management of this disease. METHODS: The study included 40 patients of rheumatoid arthritis who were randomly divided into two subgroups of 20 each. One group received conventional treatment for 12 weeks and in the other group conventional treatment was supplemented with antioxidants for the same duration. Twenty age- and sex-matched normal individuals constituted the control group. Blood samples of controls and patients were collected at the time of presentation and analyzed for total thiols, glutathione, vitamin C and malondialdehyde (MDA-marker of oxidative stress). The investigations were repeated in the patients after 12 weeks. RESULTS: The blood concentrations of total thiols, glutathione and vitamin C were found to be significantly lower in rheumatoid arthritis patients as compared to healthy controls, while the concentrations of MDA were much higher. There was a statistically significant increase in the posttreatment concentrations of these antioxidants, along with a decrease in the concentrations of MDA. CONCLUSIONS: The antioxidant defense system is compromised in rheumatoid arthritis patients. There is a shift in the oxidant/antioxidant balance in favor of lipid peroxidation, which could lead to the tissue damage observed in the disease. The results suggest the necessity for therapeutic co-administration of antioxidants along with conventional drugs to such patients. However, due to the limited number of cases included in this study, more studies may be required to substantiate the results and arrive at a definite conclusion, in terms of safety and efficacy of adding on antioxidant therapy for the treatment of RA.     

Inhibition of Chk1 by the G2 DNA damage checkpoint inhibitor isogranulatimide

Inhibitors of the G(2) DNA damage checkpoint can selectively sensitize cancer cells with mutated p53 to killing by DNA-damaging agents. Isogranulatimide is a G(2) checkpoint inhibitor containing a unique indole/maleimide/imidazole skeleton identified in a phenotypic cell-based screen; however, the mechanism of action of isogranulatimide is unknown. Using natural and synthetic isogranulatimide analogues, we show that the imide nitrogen and a basic nitrogen at position 14 or 15 in the imidazole ring are important for checkpoint inhibition. Isogranulatimide shows structural resemblance to the aglycon of UCN-01, a potent bisindolemaleimide inhibitor of protein kinase C beta (IC(50), 0.001 micromol/L) and of the checkpoint kinase Chk1 (IC(50), 0.007 micromol/L). In vitro kinase assays show that isogranulatimide inhibits Chk1 (IC(50), 0.1 micromol/L) but not protein kinase C beta. Of 13 additional protein kinases tested, isogranulatimide significantly inhibits only glycogen synthase kinase-3beta (IC(50), 0.5 micromol/L). We determined the crystal structure of the Chk1 catalytic domain complexed with isogranulatimide. Like UCN-01, isogranulatimide binds in the ATP-binding pocket of Chk1 and hydrogen bonds with the backbone carbonyl oxygen of Glu(85) and the amide nitrogen of Cys(87). Unlike UCN-01, the basic N15 of isogranulatimide interacts with Glu(17), causing a conformation change in the kinase glycine-rich loop that may contribute importantly to inhibition. The mechanism by which isogranulatimide inhibits Chk1 and its favorable kinase selectivity profile make it a promising candidate for modulating checkpoint responses in tumors for therapeutic benefit.     

Macronutrients in breastmilk of mothers of preterm infants

Objectives

To evaluate the variability in macronutrient and energy content of breastmilk of Indian women delivering at ≤34 weeks of gestation.

Methods

In this cross-sectional study, samples of breastmilk expressed manually for feeding of preterm neonates were collected from 106 mothers at 3±1 (n=26), 7±2 (n=34), 14±2 (n=24), 21±3 (n=12) and 28±3 (n=10) days after birth. Protein, fat and carbohydrate content were estimated and total energy content was calculated.

Results

Protein content in the human milk declined from 4.1±2.1 g/dL on the 3rd postpartum day to 2.2±0.6 g/dL by the 28th day postpartum. Lactose (from 2.2±0.7 g/dL to 3.0±0.9 g/dL), fat (1.9±1.8 g/dL to 3.4±2.1 g/dL) and energy (42.3±18.8 Kcal/dL to 51.9±21.5 Kcal/dL) contents increased from day 3 to day 28.

Conclusions

Preterm human milk has high temporal and inter-individual variation in the macronutrient composition and without fortification is unlikely to meet the nutritional requirement of preterm neonates.

     

Lipoprotein (a) in type 2 diabetes mellitus: Relation to LDL:HDL ratio and glycemic control

BACKGROUND:

Increased lipoprotein (a) [Lp (a)] concentrations are predictive of coronary artery disease (CAD). Type 2 diabetes mellitus also leads to dyslipidemia, like elevated triglyceride levels and low HDL levels, which are known risk factors for CAD. This study was designed to investigate the levels of Lp (a) in type 2 diabetic patients and their association with LDL: HDL ratio and glycemic control.

MATERIALS AND METHODS:

The study included 60 patients of type 2 diabetes and 50 age and sex matched controls. The Lp(a) levels in the diabetic group were compared with the control group and the relationship between the Lp(a) levels and LDL: HDL ratio was evaluated. Diabetic group was further divided into three subgroups according to levels of glycated hemoglobin. Lp(a) levels and glycated hemoglobin in controlled and uncontrolled diabetes mellitus were also compared to find out any correlation between them. Statistical analysis was done using the students ‘t’ test and Chi square test.

RESULTS:

Lp(a) levels were found to be significantly increased in the diabetic group as compared to the control group (P< 0.001). LDL: HDL ratio was also increased in the diabetic group as compared to the control group. Lp(a) levels showed no association with LDL: HDL ratio and degree of glycemic control in these patients.

CONCLUSIONS:

The results of the present study suggest that Lp(a) levels are increased in type 2 diabetic patients. The elevated Lp(a) levels do not reflect the glycemic status and are also independent of increase in LDL:HDL ratio suggesting different metabolic pathways and the genetic connection for LDL and Lp(a).     

Do SNPs in folate pharmacokinetic pathway alter levels of intracellular methotrexate polyglutamates and affect response? A prospective study in Indian patients

This study investigated the impact of seven polymorphisms in genes of folate transport and (de)glutamation pathway on methotrexate polyglutamate levels and response in patients with rheumatoid arthritis. This prospective study included patients with rheumatoid arthritis. They were treated with methotrexate (up to 25 mg per week) for 24 weeks and categorized by EULAR response criteria into responders (good and moderate) and non-responders. Using real-time Taqman discrimination assay, SNPs were genotyped—rs1045642 (ABCB1 3435C>T), rs1128503 (ABCB1 1236C>T), rs10106 (FPGS 1994A>G), rs1544105 (FPGS G>A), rs11545078 (GGH 452C>T), rs3758149 (GGH -401C>T), and rs1051266 (RFC1 80G>A). RBC methotrexate polyglutamate_1–5(MTX-glu_1–5) levels were determined at 4, 8, 16, and 24 weeks using by reverse phase HPLC using C-18 column followed by post column photo-oxidation. This study included 117 patients with rheumatoid arthritis (M:F?=?14:103). The mean dose of methotrexate at 24 weeks was 22.0?±?4.0 mg, with data on DAS28(3) at 24 weeks available in 96 patients—61 responders and 35 non-responders. Minor allele of GGH 452C>T had an association with non-response (odds ratio 2.9, 95% CI 1.4–5.6) and assuming the dominance of C, the recessive genetic model found GGH 452C>T CC genotype (odds ratio 9.5, 95% CI 1.2 to 76.0) was significantly associated with response. However, there was no difference in MTX-glu_1–5 levels among the various genotypes of this SNP (p?=?0.9). Other SNPs were neither associated with response nor with alteration in methotrexate polyglutamate levels. On logistic regression, GGH 452C>T CC genotype and DAS28(3) at baseline were independent predictors of response. GGH 452C>T CC genotype was associated with response to methotrexate. None of the SNPs affected MTX-glu_1–5levels.     

Clinico-genetic model to predict methotrexate intolerance in rheumatoid arthritis

Clinical Rheumatology - Methotrexate is the gold-standard DMARD in rheumatoid arthritis but is often associated with “mild” adverse effects like intolerance or laboratory abnormalities....     

Ringer’s lactate vs normal saline for children with acute diarrhea and severe dehydration: A double blind randomized controlled trial

Objective

WHO recommends Ringer’s lactate (RL) and Normal Saline (NS) for rapid intravenous rehydration in childhood diarrhea and severe dehydration. We compared these two fluids for improvement in pH over baseline during rapid intravenous rehydration in children with acute diarrhea.

Design

Double-blind randomized controlled trial

Setting

Pediatric emergency facilities at a tertiary-care referral hospital.

Intervention

Children with acute diarrhea and severe dehydration received either RL (RL-group) or NS (NS-group), 100 mL/kg over three or six hours. Children were reassessed after three or six hours. Rapid rehydration was repeated if severe dehydration persisted. Blood gas was done at baseline and repeated after signs of severe dehydration disappeared.

Outcome Measures

Primary outcome was change in pH from baseline. Secondary outcomes included changes in serum electrolytes, bicarbonate levels, and base-deficit from baseline; mortality, duration of hospital stay, and fluids requirement.

Results

Twenty two children, 11 each were randomized to the two study groups. At primary end point (disappearance of signs of severe dehydration), the improvement in pH from baseline was not significant in RL-group [from 7.17 (0.11) to 7.28 (0.09)] as compared to NS-group [7.09 (0.11) to 7.21 (0.09)], P=0.17 (after adjusting for baseline serum Na/Cl). Among this limited sample size, children in RL group required less fluids [median 310 vs 530 mL/kg, P=0.01] and had shorter median hospital stay [38 vs 51 hours, P=0.03].

Conclusions

There was no difference in improvement in pH over baseline between RL and NS among children with acute diarrhea and severe dehydration.