Migraine and cardiovascular disease: a population-based study

OBJECTIVES

Although the relationship between migraine and cardiovascular disease (CVD) has been studied, several questions remain unanswered. Herein we contrast the rate of diagnosed CVD as well as of risk factors for CVD in individuals with migraine with and without aura (MA and MO) and in controls.

METHODS

In this case-control study, migraineurs (n = 6,102) and controls (n = 5,243) were representative of the adult US population. Headache diagnosis was formally assigned using a validated mailed questionnaire which also obtained details on treatment, comorbidities, and other variables. CVD events were obtained based on self-reported medical diagnosis. Risk factors for CVD and modified Framingham scores were computed.

RESULTS

In unadjusted analyses, migraine overall and MA were associated with myocardial infarction, stroke, and claudication, and MO was associated with myocardial infarction and claudication. Migraineurs were more likely than controls to have a medical diagnosis of diabetes (12.6% vs 9.4%, odds ratio [OR] 1.4, 95% confidence interval [CI] 1.2-1.6), hypertension (33.1% vs 27.5%, OR 1.4, 95% CI 1.3-1.6), and high cholesterol (32.7% vs 25.6%, OR 1.4, 95% CI 1.3-1.5). Risk was highest in MA, but remained elevated in MO. Framingham scores were significantly higher in MO and MA than in controls. After adjustments (gender, age, disability, treatment, CVD risk factors), migraine remained significantly associated with myocardial infarction (OR 2.2, 95% CI 1.7-2.8), stroke (OR 1.5, 95% CI 1.2-2.1), and claudication (OR 2.69, 95% CI 1.98-3.23).

CONCLUSION

Both migraine with and without aura are associated with cardiovascular disease (CVD) and with risk factors for CVD. However, since our sample size is large, the clinical relevance of the differences is yet to be established.

Epileptogenesis and enhanced prepulse inhibition in GABA(B1)-deficient mice

The recent cloning of two GABA(B) receptor subunits, GABA(B1) and GABA(B2), has raised the possibility that differences in GABA(B) receptor subunit composition may give rise to pharmacologically or functionally distinct receptors. If present, such molecular diversity could permit the selective targeting of GABA(B) receptor subtypes specifically involved in pathologies such as drug addiction, spasticity, pain, and epilepsy. To address these issues we have developed a GABA(B1) subunit knockout mouse using gene targeting techniques. In the brains of GABA(B1) null mice, all pre- and postsynaptic GABA(B) receptor function was absent demonstrating that the GABA(B1) subunit is essential for all GABA(B) receptor-mediated mechanisms. Despite this, GABA(B1) null mice appeared normal at birth, although by postnatal week four their growth was retarded and they developed a generalized epilepsy that resulted in premature death. In addition, GABA(B1) heterozygote animals showed enhanced prepulse inhibition responses compared to littermate controls, suggesting that GABA(B1) deficient mice exhibit increased sensorimotor gating mechanisms. These data suggest that GABA(B) receptor antagonists may be of benefit in the treatment of psychiatric and neurological disorders in which attentional processing is impaired.

Ventilatory and heart rate responses to exercise : better predictors of heart failure mortality than peak oxygen consumption

BACKGROUND

An abnormally low chronotropic response and an abnormally high ventilatory response (V(E)/V(CO2)) to exercise are common in patients with severe heart failure, but their relative prognostic impacts have not been well explored.

METHODS AND RESULTS

Consecutive patients with heart failure referred for metabolic stress testing who were not taking beta-blockers or intravenous inotropes (n=470) were followed for 1.5 years. The chronotropic index was calculated while peak V(O2) and V(E)/V(CO2) were directly measured. Chronotropic index and peak V(O2) were considered abnormal if in the lowest 25th percentiles of the patient cohort, whereas V(E)/V(CO2) was considered abnormal if in the highest 25th percentile. For comparative purposes, a group of 17 healthy controls underwent metabolic testing as well. Compared with controls, heart failure patients had markedly abnormal ventilatory and chronotropic responses to exercise. In the heart failure cohort, there were 71 deaths. In univariate analyses, predictors of death included high V(E)/V(CO2) low chronotropic index, low V(O2), low resting systolic blood pressure, and older age. Nonparametric Kaplan-Meier plots demonstrated that by dividing the population according to peak V(E)/V(CO2) and peak V(O2), it is possible to identify low, intermediate, and very high risk groups. In multivariate analyses, the only independent predictors of death were high V(E)/V(CO2) (adjusted relative risk [RR] 3.20, 95% CI 1.95 to 5.26, P<0.0001) and low chronotropic index (adjusted RR 1.94, 95% CI 1.18 to 3.19, P=0.0009).

CONCLUSIONS

The ventilatory and chronotropic responses to exercise are powerful and independent predictors of heart failure mortality.

A UK multicentre study of the antimicrobial susceptibility of bacterial pathogens causing urinary tract infection

OBJECTIVES

To determine the prevalence of resistance amongst urinary tract pathogens against antimicrobials used to treat urinary tract infections (UTIs) in the UK to provide data to help direct empirical therapy.

METHOD

During 1999-2000, a total of 1291 bacterial isolates causing UTI were collected from 8 centres in the UK. Isolates were cultured from patients with (1). community-acquired UTI in those less than 65 years old (397), (2). hospital-acquired UTI other than those admitted with pyelonephritis (394), (3). pyelonephritis (108) and (4). community-acquired UTI in those greater than 65 years old (392). After re-identification, MICs for a range of antimicrobials were determined and interpreted using NCCLS procedures and interpretive guidelines.

RESULTS

Escherichia coli was the predominant pathogen in all categories but the total percentage for each category varied (56.3-77.3%). The next three pathogens of importance were Enterococcus faecalis, Klebsiella pneumoniae and Proteus mirabilis which varied in prevalence slightly from category to category. The activity of amoxycillin against E. coli (51.3% susceptible) was greatly reduced as a result of beta-lactamase production and only partially restored by the addition of clavulanic acid (78.8% susceptible). Cefuroxime was very active against E. coli using parenteral form breakpoints (97.1% susceptible) but less so using oral form breakpoints (68.6% susceptible). Cefuroxime was inactive against Enterococcus spp. and Pseudomonas spp. Nitrofurantoin was very active against isolates of E. coli (96.3% susceptible) and E. faecalis but not against K. pneumoniae, P. mirabilis or Pseudomonas aeruginosa. Overall susceptibility to trimethoprim ranged from 58.1% to 84.5% for the most prevalent pathogens. Ciprofloxacin was highly active against the UTI pathogens examined in this study with susceptibilities of between 88.6% and 97.7% for the most prevalent pathogens (E. coli, n=864, 97.7% susceptible) and was the only oral agent tested with activity against Pseudomonas spp.

CONCLUSION

These data provide much needed information on the prevalence of antimicrobial resistance amongst pathogens currently causing UTI in the UK.

A radioimmunoassay for immunologic phenomena in pneumococcal disease and for the antibody response to pneumococcal vaccines. I. Method for the radioimmunoassay of anticapsular antibodies and comparison with other techniques

A radioimmunossay is described which uses a 14C biosynthetically internally labeled antigen. This modified Farr technique has been standardized by quantitative precipitation and compared with hemagglutination and mouse protection. Specificity was established by use of heterologous hyperimmune sera and by use of unlabeled pneumococcal polysaccharides for inhibition. Reproducibility has been evaluated for different preparations of antigens and varying storage conditions of sera. The system has been applied to a wide variety of studies requiring analysis of human and animal sera.

Magnetic resonance imaging of central nervous system lesions in patients with lupus erythematosus. Correlation with clinical remission and antineurofilament and anticardiolipin antibody titers

Clinical, magnetic resonance imaging (MRI), and serologic studies were performed on 11 patients with diffuse central nervous system (CNS) systemic lupus erythematosus and 8 patients with focal CNS lupus. MRI of patients with diffuse clinical disease showed symmetrically distributed areas of increased signal intensity in the subcortical white matter; these resolved after treatment with high-dose methylprednisolone. These patients' sera contained elevated levels of antineurofilament antibodies. Patients with focal CNS lupus had areas of increased signal intensity and atrophic changes in regions corresponding to the major cerebral vessels. These MRI abnormalities did not improve after treatment with high-dose steroids. The sera of patients with focal CNS lupus had elevated levels of cardiolipin and lupus anticoagulant but normal levels of antineurofilament antibody. Our findings suggest that results of a combined clinical, MRI, and serologic evaluation of patients with CNS lupus may predict the response of patients to high-dose steroid therapy.

The imPaCT study: a randomised controlled trial to evaluate a hospital palliative care team

A randomised controlled trial was undertaken to assess the effectiveness of a hospital Palliative Care Team (PCT) on physical symptoms and health-related quality of life (HRQoL); patient, family carer and primary care professional reported satisfaction with care; and health service resource use. The full package of advice and support provided by a multidisciplinary specialist PCT ('full-PCT') was compared with limited telephone advice ('telephone-PCT', the control group) in the setting of a teaching hospital trust in the SW of England. The trial recruited 261 out of 684 new inpatient referrals; 175 were allocated to 'full-PCT', 86 to 'telephone-PCT' (2 : 1 randomisation); with 191 (73%) being assessed at 1 week. There were highly significant improvements in symptoms, HRQoL, mood and 'emotional bother' in 'full-PCT' at 1 week, maintained over the 4-week follow-up. A smaller effect was seen in 'telephone-PCT'; there were no significant differences between the groups. Satisfaction with care in both groups was high and there was no significant difference between them. These data reflect a high standard of care of patients dying of cancer and other chronic diseases in an acute hospital environment, but do not demonstrate a difference between the two models of service delivery of specialist palliative care.

Assembly and regulation of the CD40 receptor complex in human B cells

CD40 is a member of the tumor necrosis factor (TNF) receptor superfamily. Studies with human B cells show that the binding of CD154 (gp39, CD40L) to CD40 recruits TNF receptor- associated factor 2 (TRAF2) and TRAF3 to the receptor complex, induces the downregulation of the nonreceptor-associated TRAFs in the cell and induces an increased expression of Fas on the cell surface. Combined signaling through the interluekin 4 receptor and CD40 induces an increased expression of Fas with a commensurate increase in the level of TRAF2, but not TRAF3, that is recruited to the receptor complex. In contrast, engagement of the membrane immunoglobulin and CD40 limits Fas upregulation and reduces the recruitment of TRAF2, relative to TRAF3, to the CD40 receptor complex. These studies show that the TRAF composition of the CD40 receptor complex can be altered by signals that influence B cell differentiation.

Septo-hippocampal cholinergic and neurotrophin markers in age-induced cognitive decline

Messenger RNA (mRNA) molecules encoding proteins related to the presynaptic cholinergic and neurotrophin systems were quantitated in the hippocampus and basal forebrain of Long-Evans rats with spatial learning ability assessed in the Morris water maze. The reverse transcriptase-polymerase chain reaction showed that the mRNAs for the low-affinity neurotrophin receptor (p75-NTR) and the growth-associated protein GAP-43 were decreased in level in the basal forebrain of aged-impaired rats. In the hippocampus of these aged-impaired rats, the mRNA for VGF, another neurotrophin-inducible gene, also was decreased. In situ hybridization histochemistry revealed that mRNAs for nerve growth factor (NGF) and brain-derived neurotrophic factor increased in level in the aged rat hippocampus; when age effects were removed, NGF mRNA level remained significantly correlated with maze performance. Enzyme-linked immunosorbent assay indicated that NGF protein was expressed at normal levels in the aged rat hippocampus. These mRNA and protein alterations may signify that a defect in neurotrophin signaling exists in the brains of aged Long-Evans rats, underlying reduced plasticity responses in the basal forebrain cholinergic system.

Tissue distribution and measurement of cartilage oligomeric matrix protein in patients with magnetic resonance imaging-detected bone bruises after acute anterior cruciate ligament tears

Histologic and immunostaining analyses were performed on articular cartilage/subchondral bone biopsy specimens overlying MRI-detected bone bruises in 12 patients with anterior cruciate ligament (ACL) tears. Staining with toluidine blue for proteoglycan revealed loss of staining from the superficial portion of the articular cartilage. Immunostaining for cartilage oligomeric matrix protein (COMP) showed an increased staining in the superficial matrix of the articular cartilage. Using polyclonal antisera against COMP, the authors performed a competitive enzyme-linked immunosorbent assay (ELISA) on the synovial fluid from the injured and uninjured knees. There was an approximately 10-fold higher synovial fluid COMP levels in injured knees. The COMP levels were greater in those patients who had synovial fluid samples harvested closer to the date of initial injury. Western blot analysis of the synovial fluid showed an increased presence of COMP degradation fragments from injured knees. These results are indicative of a significant injury to the articular cartilage, and may represent preclinical posttraumatic osteoarthritic lesions.

The measurement of skin lymph flow by isotope clearance--reliability, reproducibility, injection dynamics, and the effect of massage

The measurement of skin lymph flow was investigated using an isotope clearance technique (ICT). Multiple lymph flow determinations were undertaken in the skin of anaesthetized large white pigs to test for reproducibility, ascertain the most suitable tracer, study the influence of injection dynamics, and observe the effect of massage as a stimulus to lymph flow. Blood clearance of tracer was also investigated. Results demonstrated that lymphatic clearance is a monoexponential function with good reproducibility under controlled laboratory conditions. 99mTc-colloid (TCK17 Cis) compared favorably with 131I-human serum albumin as a tracer and both performed better than colloid gold (198Au). Lymph flow was significantly faster in one pig than in the other. No difference existed between left and right sides or between caudal and rostral sites on each flank, but clearance was significantly slower in thigh than flank skin. Sub-epidermal injections cleared faster and more consistently than either deep or subcutaneous injections. Neither injection volume nor needle tract backflow of tracer influenced results, but local massage significantly enhanced clearance. Escape of 99mTc-colloid by the blood was negligible. These results indicate that skin lymph flow can be reliably measured when conditions are controlled. Extrinsic factors such as massage strongly influence lymph flow. Greater sensitivity in detecting degrees of lymphatic insufficiency may be achieved if a standardized stimulus to lymph flow is administered during isotope clearance measurement.

Fatty acid synthase: a novel target for antiglioma therapy

High levels of fatty acid synthase (FAS) expression have been observed in several cancers, including breast, prostate, colon and lung carcinoma, compared with their respective normal tissue. We present data that show high levels of FAS protein in human and rat glioma cell lines and human glioma tissue samples, as compared to normal rat astrocytes and normal human brain. Incubating glioma cells with the FAS inhibitor cerulenin decreased endogenous fatty acid synthesis by approximately 50%. Cell cycle analysis demonstrated a time- and dose-dependent increase in S-phase cell arrest following cerulenin treatment for 24 h. Further, treatment with cerulenin resulted in time- and dose-dependent decreases in glioma cell viability, as well as reduced clonogenic survival. Increased apoptotic cell death and PARP cleavage were observed in U251 and SNB-19 cells treated with cerulenin, which was independent of the death receptor pathway. Overexpressing Bcl-2 inhibited cerulenin-mediated cell death. In contrast, primary rat astrocytes appeared unaffected. Finally, RNAi-mediated knockdown of FAS leading to reduced FAS enzymatic activity was associated with decreased glioma cell viability. These findings suggest that FAS might be a novel target for antiglioma therapy.

Purification and characterization of monodehydroascorbate reductase from soybean root nodules

Soybean (Glycine max (L.) Merr.) root nodules contain the enzymes of the ascorbate-glutathione cycle as an important defense against activated forms of oxygen. A key enzyme in this cycle--monodehydroascorbate reductase (MR)--was purified 646-fold and appeared as a single band on SDS-PAGE with silver or Coomassie blue staining. Purified MR contained 0.7 mol FAD/mol enzyme and had a specific activity of 288 mumol NADH oxidized.min-1.mg protein-1. The enzyme was a single subunit occurring as two isozymes (MR I and MR II) with Mr values of 39,000 and 40,000. Isoelectric focusing revealed that each isozyme consisted of two forms with pl values of 4.6 to 4.7. Ferricyanide and 2,6-dichlorophenol-indophenol were effective as electron acceptors. The purified enzyme did not possess leghemoglobin reductase activity. Inhibition by p-chloromercuribenzoate indicated the involvement of a thiol group in MR activity. The Km values were 5.6, 150, and 7 microM for NADH, NADPH, and monodehydroascorbate, respectively. The pH optimum was 8 to 9. The N-terminal sequence of 10 amino acids of MR II had little homology to known protein sequences.

Transcriptional regulation of neuromodulin (GAP-43) in mouse neuroblastoma clone N1E-115 as evaluated by the RT/PCR method

The steady-state level of the neuromodulin transcript in the neuron-like N1E-115 cell line was measured with a method combining reverse transcription and the polymerase chain reaction (RT/PCR). Total RNA was isolated from N1E-115 cells and treated with DNAse to remove residual DNA; cDNA was synthesized from this RNA by priming with random hexamers. For PCR amplification, primers for neuromodulin were designed for regions of the coding sequence that were identical in mouse, rat, and human. In one approach (the 'ratio method'), variations in RNA yield and cDNA synthesis efficiency were controlled for by amplifying a reference (housekeeping) gene (glyceraldehyde phosphate dehydrogenase; GAPDH). To control for inter-experimental variations in PCR amplification efficiencies the data were analyzed on semi-logarithmic plots, with which the relative levels of the starting templates could be determined by extrapolating the plots to cycle number zero (0). In another approach with RT/PCR (the 'spiking method'), the absolute level of N1E-115 neuromodulin cDNA was assessed by adding known amounts of cloned human neuromodulin template to the RT/PCR assay of N1E-115 nucleic acid and comparing the increased yield of product across cycles. When the spike was added at either the cDNA level (in the form of double-stranded DNA) or at the total RNA level (as sense RNA), the levels of N1E-115 calculated were virtually the same: 509 fg and 495 fg of coding region per ug total RNA in confluent N1E-115 cells, respectively. Treatment of N1E-115 cells with 2% dimethylsulfoxide for three days elevated neuromodulin mRNA levels 5.6-fold. Conversely, treatment of N1E-115 cells with 100 nM phorbol myristate acetate for 24 h decreased the level of neuromodulin mRNA by 70%. Under carefully controlled conditions and within certain limits of precision, the RT/PCR method appears to be suitable for assessing the level of low abundance mRNA under various pharmacologically-induced conditions.

Early extubation attempts reduce length of stay in extremely preterm infants even if re-intubation is necessary

OBJECTIVE

Prolonged mechanical ventilation in the extremely premature infant is associated with the development of bronchopulmonary dysplasia (BPD). Clinically, the decision to extubate the extremely low birth weight (ELBW) infant can be difficult. There is continued debate regarding whether it is better for an ELBW infant to remain on the ventilator or to extubate to nasal constant positive airway pressure (nCPAP). It has also been argued that repeated intubations may be detrimental to ELBW infants. We tested the hypothesis that earlier extubation attempts would decrease length of hospital stay and BPD.

STUDY DESIGN

A database maintained on infants born at <27 completed weeks gestation admitted to our all referral NICU for a 36 month period was queried (n = 224).

RESULTS

Day of life (DOL) of the first extubation attempt was inversely correlated with birth weight (p <  0.001) and gestational age (p <  0.01). The DOL of the 1st extubation attempt correlated with the need for re-intubation (p <  0.001), but not with mortality (p = 0.27). In survivors, earlier DOL of 1st extubation attempt was associated with shorter LOS (p <  0.001). Earlier DOL of the 1st extubation attempt was associated with less need for supplemental oxygen (p <  0.001) at 36 weeks CGA, while re-intubation was not (p = 0.50).

CONCLUSION

In our cohort of extremely premature infants, the earlier the first extubation attempt the sooner the patient was discharged home and the less likely to develop BPD. Our study suggests that extubation should not be delayed in extremely premature infants due to fears of need for re-intubation.

Digitalis and myocardial infarction in man

The use of digitalis after acute myocardial infarction is controversial. The effect of digoxin on computer-quantitated thallium-201 perfusion scintigrams (Tl-201), left ventricular (LV) ejection fraction (EF), and percentage of abnormally contracting LV regions (% ACR) was determined in 23 patients. A correlation was established between creatine kinase MB isoenzyme release and initial radionuclide-gated blood pool wall motion estimates of EF (r = -0.73) and % ACR (r = 0.71). After radionuclide assessments, 14 patients received digoxin 18 +/- 23 hours (mean +/- SD) after the rise in CK-MB from baseline, while the remaining nine patients served as controls. In the control group, the mean EF was 0.33 +/- 0.12 on the first study and 0.30 +/- 0.08 on the second study (p = NS). In the digoxin group, the EF after digoxin administration (mean 0.33 +/- 0.11) was significantly different from the initial EF (mean 0.29 +/- 0.09, p less than 0.03); however, digoxin had no apparent effect on infarct size as assessed by sequential % ACR and Tl-201 perfusion data. These data indicate that digoxin resulted in a minimal but significant improvement in EF that did not occur at the expense of LV perfusion or regional wall motion.

A comparative clinical trial of the TCu 380A, Lippes Loop D and Multiload Cu 375 IUDs in Indonesia

The Copper T 380A (TCu 380A), Lippes Loop D (LLD) and the Multiload Cu 375 (MLCu 375) IUDs were evaluated for safety and efficacy in a multicenter randomized clinical trial in Indonesia. A total of 2992 women were enrolled into the study and data for 2845 women were analyzed (147 cases did not meet protocol criteria). Although study IUDs were randomly assigned, LLD users in this study were older and of higher parity than TCu 380A and MLCu 375 users. The 24-month gross cumulative life-table pregnancy rates for TCu 380A, LLD and MLCu 375 users were 1.2, 2.2 and 2.7, respectively. The 24-month expulsion rates for TCu 380A, LLD and MLCu 375 users were 6.7, 7.5 and 5.3, respectively. Overall, 24-month continuation rates were 85.5%, 85.0% and 85.4% for the respective device groups. Differences in both gross and age- and parity-adjusted life-tables rates for the major outcome variables were not statistically significant at 24 months postinsertion. The study suggests that the TCu 380A, LLD and MLCu 375 IUDs seem to be safe and effective contraceptive options for Indonesian women.