Reduced folate carrier-1 80G > A gene polymorphism is not associated with methotrexate treatment response in South Indian Tamils with rheumatoid arthritis

Methotrexate (MTX) is the most commonly used disease-modifying drug to treat rheumatoid arthritis (RA). Although there are no reliable molecular markers to predict the treatment response and adverse effects to MTX therapy, the polymorphisms in genes coding for MTX metabolizing enzymes and transporters may play a crucial role. The reduced folate carrier-1 (RFC-1) is a bidirectional anion exchanger which transports MTX and folinic acid. It is reported to influence MTX treatment response and adverse effects in some ethnic populations but not in others. It is also associated with susceptibility to various diseases including systemic lupus erythematosus (SLE). The present study was aimed at investigating the role of RFC-1 80G > A gene polymorphism in association with disease susceptibility, MTX treatment response and the MTX-induced adverse events in the South Indian Tamil patients with rheumatoid arthritis. The RFC-1 80G > A gene polymorphism was investigated in 327 patients with RA and in 322 healthy controls by PCR-RFLP method. It was found that the heterozygous RFC-1 80 GA genotype was associated with protection against RA [p?=?0.02, odds ratio (OR) 0.69, 95 % confidence interval (CI) 0.50–0.95]. However, it was not found to be associated with MTX treatment response. The RFC-1?G allele frequency was higher in patients with adverse effects, but the difference was not statistically significant (p?=?0.08, OR 1.44, 95 % CI 0.97–2.13). RFC-1 80G > A gene polymorphism confers protection for RA. However, it is not associated with MTX treatment response and MTX-induced adverse effects in South Indian Tamil patients with RA.     

The genome sequence of Bifidobacterium longum subsp. infantis reveals adaptations for milk utilization within the infant microbiome

Following birth, the breast-fed infant gastrointestinal tract is rapidly colonized by a microbial consortium often dominated by bifidobacteria. Accordingly, the complete genome sequence of Bifidobacterium longum subsp. infantis ATCC15697 reflects a competitive nutrient-utilization strategy targeting milk-borne molecules which lack a nutritive value to the neonate. Several chromosomal loci reflect potential adaptation to the infant host including a 43 kbp cluster encoding catabolic genes, extracellular solute binding proteins and permeases predicted to be active on milk oligosaccharides. An examination of in vivo metabolism has detected the hallmarks of milk oligosaccharide utilization via the central fermentative pathway using metabolomic and proteomic approaches. Finally, conservation of gene clusters in multiple isolates corroborates the genomic mechanism underlying milk utilization for this infant-associated phylotype.     

Acute thrombocytopenic purpura in relation to the use of drugs

The relation of acute thrombocytopenic purpura (TP) to the use of drugs was investigated in a case-control study conducted in eastern Massachusetts, Rhode Island, and the Philadelphia region; 62 cases over the age of 16 years with acute onset and with a rapid recovery were compared with 2,625 hospital controls. After control for confounding by multiple logistic regression, use of the following drugs in the week before the onset of symptoms was significantly associated: trimethoprim/sulfamethoxazole (relative risk [RR] estimate, 124), quinidine/quinine (101), dipyridamole (14), sulfonylureas (4.8), and salicylates (2.6). The overall annual incidence of acute TP was estimated to be 18 cases per million population. The excess risks for the associated drugs were estimated to be 38 cases per million users of trimethoprim/sulfamethoxazole per week, 26 per million for quinidine/quinine, 3.9 per million for dipyridamole, 1.2 per million for sulfonylureas, and 0.4 per million for salicylates. Associations with sulfonamides, quinidine/quinine, sulfonylureas, and salicylates have been previously reported, but the present study has provided the first quantitative measures of the risk. The association with dipyridamole was unexpected. In general, despite large RRs, the incidence rates attributable to the drugs at issue (excess risks) were low, suggesting that TP is not an important consideration in the use of the various drugs.     

Lactation and neonatal nutrition: defining and refining the critical questions

This paper resulted from a conference entitled "Lactation and Milk: Defining and refining the critical questions" held at the University of Colorado School of Medicine from January 18-20, 2012. The mission of the conference was to identify unresolved questions and set future goals for research into human milk composition, mammary development and lactation. We first outline the unanswered questions regarding the composition of human milk (Section I) and the mechanisms by which milk components affect neonatal development, growth and health and recommend models for future research. Emerging questions about how milk components affect cognitive development and behavioral phenotype of the offspring are presented in Section II. In Section III we outline the important unanswered questions about regulation of mammary gland development, the heritability of defects, the effects of maternal nutrition, disease, metabolic status, and therapeutic drugs upon the subsequent lactation. Questions surrounding breastfeeding practice are also highlighted. In Section IV we describe the specific nutritional challenges faced by three different populations, namely preterm infants, infants born to obese mothers who may or may not have gestational diabetes, and infants born to undernourished mothers. The recognition that multidisciplinary training is critical to advancing the field led us to formulate specific training recommendations in Section V. Our recommendations for research emphasis are summarized in Section VI. In sum, we present a roadmap for multidisciplinary research into all aspects of human lactation, milk and its role in infant nutrition for the next decade and beyond.     

CD44 can mediate the adhesion of platelets to hyaluronan

CD44 represents a family of glycoproteins that are present on the surfaces of some types of lymphocytes, macrophages, and epithelial cells. In the present study, we have found that CD44 is also present on murine megakaryocytes and peripheral blood platelets as judged by immunohistochemical staining. Western blotting of platelet proteins indicated that this CD44 was predominantly of the 85-kD form. This form of CD44 also had the capacity to bind hyaluronan, because detergent extracts of platelets as well as intact platelets could bind soluble [3H]hyaluronan, and this property was blocked by antibodies directed against CD44. More importantly, isolated platelets could attach to the hyaluronan-containing extracellular matrix produced by cultured rat fibrosarcoma cells. This attachment took place in the absence of divalent cations and could be blocked by pretreating the rat fibrosarcoma cells with hyaluronidase or by the addition of an antibody to CD44. These results suggested that CD44 was responsible for the attachment of platelets to hyaluronan. Histochemical staining also showed that hyaluronan was present immediately beneath the endothelial cells of many blood vessels of various tissues, such as the dermis, lamina propria of the intestinal tract, the lungs, and the pericardium. Thus, it is possible that CD44 plays an important role in the attachment of platelets to the surface of exposed connective tissue after injury to endothelial cells.     

The risks of central nervous system relapse and leukoencephalopathy in patients receiving marrow transplants for acute leukemia

The records of 415 patients who received allogeneic marrow transplants for acute leukemia were reviewed to assess the risk of central nervous system (CNS) relapse and leukoencephalopathy after marrow transplantation. The Kaplan-Meier estimates of the probability of CNS relapse posttransplant were 13% for patients with acute lymphoblastic leukemia (ALL) and 2% for patients with acute nonlymphoblastic leukemia (ANL). Previous CNS disease was significantly correlated with an increased risk of CNS relapse in patients transplanted for ALL but not for ANL. In contrast, bone marrow involvement with leukemia at the time of transplant was associated with an increased risk of CNS relapse in patients with ANL but not in patients with ALL. Seventy-one patients with ALL did not receive posttransplant intrathecal methotrexate (IT- MTX) and 127 did. The probability of CNS relapse in these two groups was 38% and 7%, respectively (P less than .02). This protective benefit from IT-MTX was present in patients both with and without a history of CNS involvement or marrow involvement at the time of transplant. In patients with ANL, 116 patients did not receive posttransplant IT-MTX and 101 patients did, but no protection from CNS relapse was observed from IT-MTX irrespective of a patient's previous CNS history or marrow status at the time of transplant. Leukoencephalopathy was seen exclusively in patients who had received radiation and/or intrathecal chemotherapy to the CNS before preparation for marrow transplantation and posttransplant IT-MTX. In such patients the risk of leukoencephalopathy was 7%. From our data, it appears that posttransplant IT-MTX is a significant benefit for ALL patients in preventing CNS relapse after marrow transplantation. A similar benefit from posttransplant IT-MTX for ANL patients cannot be established from this study. In both groups, increasing total CNS therapy was associated with an increasing risk of leukoencephalopathy.     

Azathioprine does not reduce adenoma formation in a mouse model of sporadic intestinal tumorigenesis

AIM: To investigate if azathioprine could reduce adenoma formation in ApcMin/+, a mouse model of sporadic intestinal tumorigenesis.METHODS:Azathioprine was administered via drinking water(estimated 6-20 mg/kg body weight per day)to ApcMin/+and wildtype mice.Control animals received vehicle only(DMSO)dissolved in drinking water.At 15wk of age all mice were sacrificed and intestines of ApcMin/+were harvested for evaluation of polyp number.Azathioprine induced toxicity was investigated by immunohistochemical analysis on spleens.RESULTS:All azathioprine treated mice showed signs of drug-associated toxicity such as weight loss and development of splenic T-cell lymphomas.Although this suggests that the thiopurine concentration was clearly in the therapeutic range,it did not reduce tumor formation(48±3.1 adenomas vs 59±5.7 adenomas,P=0.148).CONCLUSION:We conclude that in the absence of inflammation,azathioprine does not affect intestinal tumorigenesis.