Glial fibrillary acidic protein (GFAP) immunochemical profile after Junin virus infection of rat cultured astrocytes

After five steps of purification including gel permeation, anti-angiotensin I affinity column chromatography followed by reverse-phase HPLC, a peptide immunoreactive to two different antisera (anti-angiotensin I) was purified to homogeneity from extracts of the leech Theromyzon tessulatum. The first 14 amino acid residues of the purified peptide (DRVYIHPFLLXWG) established by automated Edman degradation, reveal the existence in leeches of an angiotensin I-like molecule close to human angiotensin I. The sequence of the purified peptide presents 78.5% of homology with the N-terminal part of human angiotensin. Moreover, in its sequence, this peptide presents the cleavage sites of vertebrate angiotensin metabolic enzymes, i.e. the renin and the angiotensin-converting enzyme. This finding constitutes the first biochemical characterization of an angiotensin I in Invertebrates. It also reflects the high conservation of angiotensins in the course of evolution, suggesting a fundamental role of this family in fluid homeostasis.     

Cisplatin-induced reductions in renal functional reserve uncovered by unilateral nephrectomy: an experimental study in the pig

Summary Groups of mature Large White female pigs, approximately 10 months of age, received single intravenous infusions of 1.5, 2 or 2.5 mg/kg body weight (equivalent to90, 120 and 150 mg/m²) cisplatin. Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were measured before and at 4 weeks after cisplatin infusion by renography using [^{99 m}Tc]-DTPA (diethylenetriamminepentaacetic acid and iodohippurate sodium I 131, respectively. The left kidney of each cisplatin-treated animal plus that of four age-matched control pigs was then removed surgically,and GRF and ERPF were measured in the remaining kidney at 4 weekly intervals for up to 24 weeks after unilateral nephrectomy (UN). The pigs treated with cisplatin exhibited no consistent change in either GFR or ERPF at 4 weeks after treatment. A histological evaluation of kidneys from animals treated with 2mg/kg cisplatin that had been removed at UN revealed both tubular and glomerular lesions. The latter consisted of cell proliferation on the parietal surface of the urinary space; damage to the S₁ portion of the proximal convolution was also noted. Following UN there was a pronounced dose-dependent reduction in the functional status of the remaining kidney such that the increase in GRF and ERPF in pigs initially receiving 2.5 mg/kg cisplatin was <50% of that seen in age-matched UN controls. Moreover, the glomerular lesions observed at 4 weeks after cisplatin infusion had apparently progressed to glomerular hyalinisation by 24 weeks after UN. Thus, prior treatment with cisplatin may cause a permanent reduction in renal functional reserve that may be clinically silent until exposure to an additional nephrotoxic insult.This study was supported by the Cancer Research Campaign     

Marked bleeding diathesis in patients with platelet dysfunction due to a novel mutation in RASGRP2, encoding CalDAG-GEFI (p.Gly305Asp)

Congenital platelet function disorders are often the result of defects in critical signal transduction pathways required for platelet adhesion and clot formation. Mutations affecting RASGRP2, the gene encoding the Rap GTPase activator, CalDAG-GEFI, give rise to a novel, and rare, group of platelet signal transduction abnormalities. We here report platelet function studies for two brothers (P1 and P2) expressing a novel variant of RASGRP2, CalDAG-GEFI(p.Gly305Asp). P1 and P2 have a lifelong history of bleeding with severe epistaxis successfully treated with platelet transfusions or rFVIIa. Other bleedings include extended hemorrhage from minor wounds. Platelet counts and plasma coagulation were normal, as was αIIbβ3 and GPIb expression on the platelet surface. Aggregation of patients’ platelets was significantly impaired in response to select agonists including ADP, epinephrine, collagen, and calcium ionophore A23187. Integrin αIIbβ3 activation and granule release were also impaired. CalDAG-GEFI protein expression was markedly reduced but not absent. Homology modeling places the Gly305Asp substitution at the GEF-Rap1 interface, suggesting that the mutant protein has very limited catalytic activity. In summary, we here describe a novel mutation in RASGRP2 that affects both expression and function of CalDAG-GEFI and that causes impaired platelet adhesive function and significant bleeding in humans.     

Blood-based biomarkers for monitoring antiangiogenic therapy in non-small cell lung cancer

Tumor angiogenesis pathways have been identified as important therapeutic targets in non-small cell lung cancer. However, no biomarkers have been described as predictors of response to antiangiogenic therapy in these patients. In this study, plasma levels of VEGF, bFGF, E-selectin, and S-ICAM and gene expression profiles of peripheral blood mononuclear cells from non-small cell lung cancer patients treated with chemotherapy plus bevacizumab were analyzed before and after treatment. Values were correlated with clinicopathological characteristics and treatment response. Plasma factor levels were measured using commercially available ELISA kits. The TaqMan^® human angiogenesis array was used to investigate the effect of treatment on gene expression profiles. Kyoto Encyclopedia of Genes and Genomes and Gene Ontology enrichment analysis was performed for differentially expressed genes using WEB-based GEne SeT AnaLysis Toolkit. Our results suggest a benefit for patients with increased plasma levels of VEGF, E-selectin, and S-ICAM in the course of bevacizumab treatment. Also, we identified differentially expressed genes between paired blood samples from patients before and after treatment, and significantly perturbed pathways were predicted. These changes in gene expression and levels of plasma factors could be used to assess the effectiveness of antiangiogenic therapy, in addition to standard clinical and radiological evaluations.     

Evidence against systolic intramural forces as the primary cause of subendocardial preponderance of ischemia

Summary Verification of the current view that subendocardial preponderance of ischemia is due to greater forces generated in the deep myocardial layer during systole was undertaken. In anesthetized mongrel dogs transient ischemia was produced in two different situations of altered systolic forces. First, in order to remove that part of the systolic force which is related to intracavitary pressure, left ventricular bypass was created and the left ventricle vented. Second, in order to even out the transmural distribution of the remaining part of the forces, which is due directly to distortion and displacement of contracting fibers, ventricular fibrillation was induced in addition to venting under conditions of total cardiopulmonary bypass. In both series of experiments the ischemic area was then reperfused, normal circulation re-established and the animal allowed to survive for 3–5 days. After sacrifice, ischemic necrosis was found almost exclusively in the subendocardium. The persistence of subendocardial preponderance of ischemia under conditions of left ventricular venting and absence of coordinated contraction shows that uneven distribution of intramural forces generated during systole is not the primary cause of this preponderance.This study was supported by grants from the Polish Ministry of Health and Social Welfare (RMZ-I) and from the Polish Academy of Sciences (W. 10. 8. 4. 13. 05.).     

A Pilot Study Using Nominal Group Technique to Assess Residents’ Perceptions of Successful Attending Rounds

BACKGROUND  Ward attending rounds are fundamental for internal medicine residency training. An improved understanding of interns’ and residents’ perceptions of attending rounds should inform training programs and attending physicians. OBJECTIVES  The aim of this study was to assess residents’ perceptions of successful attending rounds. DESIGN  We convened two groups of interns and two groups of residents, to elicit their perceptions on attending rounds. SUBJECTS  Participants were recruited by e-mail and conference announcements from the 49 interns and 80 residents in the internal medicine and medicine-pediatrics residency programs. MEASUREMENTS  The nominal group technique (NGT) uses a structured group process to elicit and prioritize answers to a carefully articulated question. MAIN RESULTS  Seven interns (14%) identified 27 success factors and ranked attending approachability and enthusiasm and high quality teaching as most important. A second group of six (12%) interns identified 40 detractors and ranked having “mean attendings,” receiving disrespectful comments, and too long or too short rounds as the most significant detractors. Nine (11%) residents identified 32 success factors and ranked attention to length of rounds, house staff autonomy, and establishing goals/expectations as the most important success factors. A second group of six (8%) residents identified 34 detractors and ranked very long rounds, interruptions and time constraints, and poor rapport between team members as the most significant detractors). CONCLUSIONS  Although there was some overlap in interns’ and residents’ perceptions of attending rounds, interns identified interpersonal factors as the most important factors; whereas residents viewed structural factors as most important. These findings should assist attending physicians improve the way they conduct rounds targeting both interns and residents needs. Presented in part at the Southern Regional Meeting of the Society of General Internal Medicine in New Orleans, LA, in February 2005 and the Society of General Internal Medicine Annual Meeting in New Orleans, LA, in May 2005.     

Father Early Engagement Behaviors and Infant Low Birth Weight

Objective To examine the association of father early engagement behaviors and infant low birth weight (LBW) among unmarried, urban couples. Methods Participants were from the Fragile Families and Child Wellbeing Study, a birth-cohort study of urban families. We conducted cross-sectional analyses of data from interviews with unmarried mothers and fathers (N?=?2726) that took place at the time of their child’s birth. Early engagement behaviors were based on fathers’ self-report of whether during the pregnancy they gave mothers money to buy things for the baby, helped in other ways like providing transportation to prenatal clinics, and attended the birth. Results Most (68.9%) fathers engaged in all three early engagement behaviors; 22% engaged in 2 behaviors; and 9.1% engaged in 1 or 0 early engagement behaviors. LBW more than doubled when comparing infants of fathers who engaged in all three early engagement behaviors (9.6% predicted probability of LBW) to those fathers who engaged in no early engagement behaviors (over 22% predicted probability of LBW). Conclusion Infant and maternal health may benefit from intervention to encourage positive father engagement during pregnancy.