Association of NOS3 gene with metabolic syndrome in hypertensive patients

Recent data from animal models indicate that the eNOS null mice present a phenotype that resemble the human metabolic syndrome (hypertension, insulin resistance and hypertriglyceridemia). In this work, we have studied whether NOS3 gene, previously related to endothelial dysfunction, might have a role in metabolic syndrome susceptibility in hypertensive patients. To carry out the study, we genotyped 105 hypertensive patients < or = 60 years old with two polymorphisms of NOS3 gene: 1132 T>C and 7164 G>T (GeneBank:AF519768.1). To check the allelic frequency of these polymorphisms in our geographical area, we also genotyped 94 unselected healthy controls (control group). To perform sample genotyping, we designed a novel FRET system coupled to real time PCR. There were no differences in genotypic distribution or allelic frequency between hypertensive patients and the control group. However, we observed that 786CC genotype was significantly more frequent in hypertensive patients with metabolic syndrome than in those without the syndrome (p=0.0022). When both polymorphisms were analyzed, we identified the 786C894G as the risk haplotype for metabolic syndrome susceptibility (p=0.011). These data suggest a role of the NOS3 gene in the pathogenesis of metabolic syndrome in hypertensive patients.     

Adjuvant radiotherapy in stage IV diffuse large cell lymphoma improves outcome

The role of adjuvant radiotherapy to sites of nodal bulky disease in patients with aggressive diffuse large cell lymphoma (DLCL), and stage IV remain undefined. We began a prospective controlled clinical trial to evaluate impact in event free survival (EFS) and overall survival (OS) in a large cohort of patients with a longer follow-up. Between 1989 and 1995; 341 patients with aggressive DLCL and presence of nodal bulky disease (tumor mass > 10 cm) in pathological proven complete response after intensive chemotherapy were randomized to received either radiotherapy (involved fields, 40 Gy) or not. The 5-year EFS and OS in radiated patients were respectively: 82% (95% Confidence interval (CI): 70-89%) and 87% (95% 80-99%), that were statistically significant to control group: 55% (41-64%) (P < 0.001) and 66% (95% CI: 51-73%) (P < 0.01) respectively. Radiotherapy was well tolerated, acute toxicity was mild and until now late toxicity did not appear. The use of adjuvant radiotherapy improve EFS and OS and probably the possibility of cure in patients diffuse large cell lymphoma with worse prognostic factors. Thus, we felt that adjuvant radiotherapy will be considered as part of the initial treatment in this setting of patients.     

Characteristics of CD59 up-regulation induced in porcine endothelial cells by alphaGal ligation and its association with protection from complement

Abstract: Background: Activation of endothelial cells may result in proinflammatory and procoagulant changes, or in changes that protect the endothelial cells (EC) from injurious insults. Stimulation of porcine EC with human anti‐porcine antibodies, or lectins from Bandeiraea simplicifolia that bind terminal Galα(1–3)Gal (abbreviated αGal), can induce EC protection from cytotoxicity by human complement. These EC also exhibit up‐regulation of CD59 protein and mRNA expression. Porcine CD59 has been reported to protect porcine cells from human complement. Therefore we investigated the specificity requirements and other characteristics of the induced CD59 up‐regulation, as well as the role of up‐regulated CD59 in lectin‐induced protection of EC from human complement. Methods: Aortic EC were incubated in vitro with αGal‐binding lectins B. simplicifolia lectin I isolectin B4 (IB4) and B. simplicifolia lectin I (BS‐I) and CD59 expression was assessed by flow cytometry and enzyme linked immunosorbent assay (ELISA). Binding requirement was studied using disaccharides containing either αgalactosyl or βgalactosyl moieties to inhibit CD59 up‐regulation. Protection from complement killing was assessed after incubation of EC with human serum as a source of anti‐porcine antibodies and complement. The role of CD59 in lectin‐induced protection was studied in the presence of an anti‐pig CD59 antibody and after removal of CD59 using phosphatidylinositol (PI)‐specific phospholipase C (PI‐PLC). Results: We found that induction of CD59 up‐regulation required specific binding of the lectin to terminal αGal and was not induced either by soluble factors that may be released from EC by stimulation with the lectin or by TNF‐α, IFN‐γ, or IL‐1α. Unstimulated or BS‐I‐treated EC showed little or no expression of decay accelerator factor (DAF). Removal of membrane‐associated CD59 (and other proteins that are associated with the membrane through PI linkage) with PI‐PLC from EC that had been exposed to lectin restored their complement sensitivity to various degrees, depending on the extent of lectin‐induced protection. Cytotoxicity was completely restored in cells that exhibited partial protection induced with lectin at low doses or for a short period of time. However, EC that were fully resistant to complement did not regain sensitivity to complement after removal of CD59. Changes in CD59 expression did not modify the degree of C9 binding. Conclusion: Induction of CD59 expression required specific binding of the lectin to terminal αGal and was not induced by soluble factors that may be released from EC by lectin stimulation. Increased CD59 expression may contribute to this form of protection from complement; however, mechanisms other than CD59 up‐regulation appear to be essential for the development of full protection.     

Behavioural sensitization and enhanced dopamine response in the nucleus accumbens after intravenous cocaine self-administration in mice

The behavioural effects of cocaine are enhanced in animals with a prior history of repeated cocaine administration. This phenomenon, referred to as sensitization, is also associated with an increase in cocaine-evoked extracellular dopamine levels in the nucleus accumbens. Behavioural and neurochemical sensitization has been demonstrated in rats with a prior history of cocaine self-administration and in those that had received experimenter-administered cocaine. Although it is clear that the repeated non-contingent administration also results in behavioural sensitization in the mouse, the issue of whether behavioural and neurochemical sensitization also occur in this species following intravenous cocaine self-administration has not been assessed. The present study used the technique of in vivo microdialysis in conjunction with operant self-administration to characterize cocaine-evoked locomotor activity and dopamine levels in the nucleus accumbens in mice with a prior history of intravenous cocaine self-administration or those that had received yoked infusions of cocaine. Mice that had received contingent or non-contingent infusions of cocaine exhibited an enhanced behavioural response to cocaine and increased cocaine-evoked dopamine levels in the nucleus accumbens. There was no difference between groups in the magnitude of this effect. Prior exposure to cocaine did not modify baseline dopamine levels in the nucleus accumbens. These data demonstrate that mice with previous cocaine self-administration experience show an enhanced behavioural and dopamine response to cocaine in the nucleus accumbens. Furthermore, control over cocaine infusion does not significantly alter the magnitude of the sensitized behavioural and presynaptic dopamine responses observed in response to a challenge dose of cocaine.     

Phase I study of AG 331, a novel thymidylate synthase inhibitor, in patients with refractory solid tumors

Purpose: This was a phase I study of AG 331 to determine systemic tolerance and pharmacokinetics following single and multiple escalating intravenous doses. Methods: The study was an open-label phase I trial that was divided into two components. In phase IA (single dose), six dose levels from 12.5 to 225 mg/m² were administered to 18 patients (3 at each dose level) and serial blood samples were collected for 72 h. Upon achieving satisfactory pharmacologic parameters, the multiple dosing component (phase IB) was initiated. Six dose levels from 50 to 800 mg/m² per day were administered for 5 consecutive days to 18 patients. Pre- and postdose blood samples were obtained on days 1–4 and serial blood samples were collected over 24 h following dose 5. Nonhematologic and hepatic toxicities were assessed, serum AG 331 concentrations were measured and pharmacokinetic parameters determined. Results: Other than fatigue, no severe toxicities were encountered in phase IA. Liver toxicity was manifested by elevations in transaminase first noted at multiple doses of 200 mg/m² per day for 5 days. Fever and malaise but no myelosuppression were noted. The mean terminal t_1/2 following single doses was significantly shorter than the t_1/2 following multiple dosing (6.8 vs 9.9 h) and clearance was significantly faster following single doses than following multiple dosing (81.7 vs 30.4 1/h), but no significant difference in V_d was noted. Conclusions: The dose-related toxicity profile precludes further clinical development at this time. The pharmacokinetics of AG 331 following single and multiple doses showed significant differences. Received: 11 July 1997 / Accepted: 18 September 1998     

Breast-feeding and mental and motor development at 51/2 years.

OBJECTIVE: Breast-feeding is associated with better child development outcomes, but uncertainty remains primarily due to the close relationship between breast-feeding and socioeconomic status. This study assesses the issue in a low socioeconomic status sample where breast-feeding was close to universal. METHODS: Seven hundred eighty-four Chilean children were followed longitudinally from infancy. All but four were initially breastfed, 40% nursed beyond 12 months, and infant growth was normal. Child development was assessed at 5(1/2) years by a cognitive, language, and motor test battery. The duration of breast-feeding as the sole milk source was analyzed as a continuous variable, adjusting for a comprehensive set of background factors. RESULTS: The relationship between breast-feeding and most 5(1/2)-year developmental outcomes was nonlinear, with poorer outcome for periods of breast-feeding as the sole milk source for <2 months or >8 months--statistically significant for language, motor, and one comprehensive cognitive test, with a suggestive trend for IQ. CONCLUSIONS: The observed nonlinear relationships showed that breast-feeding as the sole milk source for <2 months or >8 months, compared with 2-8 months, was associated with poorer development in this sample. The latter finding requires replication in other samples where long breast-feeding is common and socioeconomic status is relatively homogeneous.     

Enhancement of tumor-associated glycoprotein-72 antigen expression in hormone-related ovarian serous borderline tumors

The immunoreactivity of monoclonal antibody (MoAb) B72.3 with ovarian serous tumors of borderline malignancy from 44 women who were pregnant, were on hormone medication containing a progestin, or were known to be in the secretory phase of the menstrual cycle, was compared with that of similar tumors of 32 patients who were not known to be in any of these three categories. All 76 borderline tumors expressed the tumor-associated glycoprotein (TAG-72) recognized by MoAb B72.3. Striking staining differences (P less than 0.0001) were observed between the hormone-related and the nonhormone-related tumors. Differences were also noticed between the staining of tumors from pregnant patients and that of previous, persistent, or recurrent tumors of the ipsilateral or contralateral ovaries when the same patients were not pregnant. Tumor MoAb B72.3 reactivity increased with progressive gestational age and fell to lower levels at term and during the postpartum period. Although it has been suggested by cell culture studies, enhanced TAG-72 expression in human tumors under hormonal stimulation has not been described before.