Estimating the undetected burden of influenza hospitalizations in children.

During the 2004-2005 influenza season two independent influenza surveillance systems operated simultaneously in three United States counties. The New Vaccine Surveillance Network (NVSN) prospectively enrolled children hospitalized for respiratory symptoms/fever and tested them using culture and RT-PCR. The Emerging Infections Program (EIP) and a similar clinical-laboratory surveillance system identified hospitalized children who had positive influenza tests obtained as part of their usual medical care. Using data from these systems, we applied capture-recapture analyses to estimate the burden of influenza related-hospitalizations in children aged<5 years. During the 2004-2005 influenza season the influenza-related hospitalization rate estimated by capture-recapture analysis was 8.6/10,000 children aged<5 years. When compared to this estimate, the sensitivity of the prospective surveillance system was 69% and the sensitivity of the clinical-laboratory based system was 39%. In the face of limited resources and an increasing need for influenza surveillance, capture-recapture analysis provides better estimates than either system alone.

[Silent myocardial ischemia and exercise-induced arrhythmia detected by the exercise test in the total health promotion plan (THP)].

We investigated the prevalence and characteristics of ischemic heart disease especially silent myocardial ischemia (SMI) and arrhythmia in need of careful observation in the exercise stress tests in the Total Health Promotion Plan (THP), which was conducted between 1994-96 for the purpose of measuring cardiopulmonary function. All workers (n = 4,918, 4,426 males) aged 18-60 yr old in an occupational field were studied. Exercise tests with an ergometer were performed by the LOPS protocol, in which the maximal workload was set up as a presumed 70-80% maximal oxygen intake, or STEP (original multistage protocol). ECG changes were evaluated with a CC5 lead. Two hundred and fifteen people refused the study because of a common cold, lumbago and so on. Of 4,703 subjects, 17 with abnormal rest ECG and 19 with probable anginal pain were excluded from the exercise tests. Of 4,667 who underwent the exercise test, 37 (0.79%) had ischemic ECG change, and 155 (3.32%) had striking arrhythmia. These 228 subjects then did a treadmill exercise test with Bruce protocol. Twenty-two (0.47% of 4,703) showed positive ECG change, 9 (0.19%) of 22 had abnormal findings on a 201Tl scan. 8 (0.17%) were diagnosed as SMI (Cohn I), in which the prevalence of hypertension, hyperlipidemia, diabetes mellitus, smoker and positive familial history of ischemic heart disease was greater than that of all subjects. In a 15-30 month follow up, none has developed cardiac accidents. Exercise-induced arrhythmia was detected in 11 (0.23%) subjects. Four were non-sustained ventricular tachycardia without any organic disease, 4 were ventricular arrhythmia based on cardiomyopathy detected by echocardiography, 2 were atrial fibrillation and another was WPW syndrome. It is therefore likely that the ergometer exercise test in THP was effective in preventing sudden death caused by ischemic heart disease or striking arrhythmia.

Walking 10,000 steps/day or more reduces blood pressure and sympathetic nerve activity in mild essential hypertension.

We investigated the effects of walking 10,000 steps/day or more on blood pressure and cardiac autonomic nerve activity in mild essential hypertensive patients. All subjects were males aged 47.0+/-1.0 (mean+/-SEM) years old. The original cohort consisted of 730 people in a manufacturing industry who measured the number of steps they walked each day using a pedometer. Eighty-three of these subjects walked 10,000 steps/day or more for 12 weeks. Thirty-two of these were hypertensives with systolic blood pressure (SBP) greater than 140 mmHg and/or diastolic blood pressure (DBP) greater than 90 mmHg. Thirty of these hypertensive subjects (HT) were examined twice, once during the pre- and once during the post-study period, for body mass index (BMI), maximal oxygen intake (Vo2max), blood pressure, heart rate (HR), and autonomic nerve activity by power spectral analysis of SBP and HR variability. In the HT group, walking 13,510+/-837 steps/day for 12 weeks lowered blood pressure (from 149.3+/-2.7/98.5+/-1.4 to 139.1+/-2.9/90.1+/-1.9 mmHg; p<0.01, respectively). In both the 34 normotensive controls and 17 hypertensive sedentary controls, blood pressure did not change. Walking also significantly lowered low-frequency fluctuations in SBP as an index of sympathetic nerve activity, from 1.324+/-0.192 to 0.738+/-0.154 mmHg2/Hz (p<0.05). VO2max rose significantly from 26.1+/-2.4 to 29.5+/-2.5 ml/kg/min (p<0.05). There were no changes in parasympathetic nerve activity, baroreceptor reflex sensitivity, or BMI. Our results indicate that walking 10,000 steps/days or more, irrespective of exercise intensity or duration, is effective in lowering blood pressure, increasing exercise capacity, and reducing sympathetic nerve activity in hypertensive patients.

A randomized study of the safety and antiretroviral activity of hydroxyurea combined with didanosine in persons infected with human immunodeficiency virus type 1. American Foundation for AIDS Research Community-Based Clinical Trials Network.

This randomized open-label trial of human immunodeficiency virus type 1-infected persons compared safety and efficacy for 38 patients receiving hydroxyurea/didanosine combination therapy with findings in 42 persons given didanosine monotherapy for 12 weeks, followed by 12 weeks of hydroxyurea/didanosine combination therapy for all patients. Week 12 on-treatment group comparisons showed a mean decrease in virus load between hydroxyurea/didanosine versus didanosine groups of -0.93 versus -0.74 log10 copies/mL (P=.20); a higher percentage of the hydroxyurea/didanosine group below the assay's detection limit (500 copies/mL), 29% versus 7% (P=.017); and median change in CD4 cells for the hydroxyurea/didanosine versus didanosine group of 0 versus 43 cells/mm3 (P=.045), although median change in CD4 percentage was similar (0.9% vs. 1.2%, P=.64). Week 24 virus load reductions and CD4 cell changes were similar in both groups. Intent-to-treat and on-treatment analyses showed similar results. The hydroxyurea/didanosine combination was well tolerated.

Assessment of the ability of the topical skin protectant (TSP) to protect against contact dermatitis to urushiol (Rhus) antigen.

BACKGROUND: Military personnel have a need for effective protection against cutaneous exposure to chemical warfare agents (CWA). Topical Skin Protectant (TSP) is being developed to supplement chemical warfare protective garments. TSP protects against CWA exposure in animals, but does it work for humans? Because humans should not be tested with live CWA, urushiol (poison ivy) extract was used as a surrogate substance in place of CWA for human efficacy testing of TSP. OBJECTIVE: Determine whether TSP protects human skin against experimentally-induced urushiol dermatitis. METHODS: Open urushiol patch testing of 50 rhus-sensitive subjects comparing the 96-hour dermatitis severity scores between TSP protected and TSP unprotected sites. There were 4 paired sites (i.e., protected versus unprotected) per subject. Test sites were scored using a 9-point dermatitis scale of 0.0 to 4.0 (using 0.5 increments). RESULTS: Analysis of variance of the dermatitis scores from 192 paired sites on 48 evaluable subjects showed that TSP protected sites had mean dermatitis scores about 2 points lower than TSP unprotected sites (P <.001). CONCLUSION: Although this study does not provide direct scientific evidence that TSP protects humans against the percutaneous absorption of CWA, it does provide circumstantial evidence that this is the case. The fact that TSP is so highly effective against a lipophilic substance like urushiol and that most common vesicant CWAs are lipophilic and are weaponized in oleaginous vehicles, makes the effectiveness of TSP in preventing absorption and dermatitis from CWA seem likely.

Simultaneous screening for three correlated lipids in the VA HDL Intervention Trial.

We developed methodology to design the multistage lipid screen for the VA HDL Intervention Trial, a randomized double-blind placebo-controlled secondary prevention clinical trial of 2531 participants. The trial aimed to determine if HDL-raising therapy reduces coronary events in men with low HDL-cholesterol and desirable LDL-cholesterol. Joint lipid distributions for HDL-cholesterol, LDL-cholesterol, and triglycerides were derived on the basis of estimates from previous studies, and simulations were performed to determine the cutpoints for excluding screenees for the three lipid parameters to be used at each recruitment stage. Operating characteristics for different screening rules are presented. Comparisons between the predicted and actual study recruitment results show good agreement in lipid characteristics and underscore the complexity of simultaneously screening on correlated continuous physiologic parameters such as lipids.

TAK-147, an acetylcholinesterase inhibitor, increases choline acetyltransferase activity in cultured rat septal cholinergic neurons.

TAK-147, a potent acetylcholinesterase (AChE) inhibitor, potentiated choline acetyltransferase (ChAT) activity in cultured rat septal cholinergic neurons in a concentration-dependent manner with an EC50 value of 4.47 nM. Donepezil, another potent AChE inhibitor, also increased ChAT activity although its potency was less than that of TAK-147. Other AChE inhibitors (rivastigmine, tacrine, physostigmine and neostigmine) showed no effect. The effects of TAK-147 were greater in the presence of NGF, suggesting a synergistic action of TAK-147 and NGF. TAK-147 and donepezil showed high affinity for sigma receptors, whereas tacrine and physostigmine did not. Haloperidol and ifenprodil, high-affinity sigma ligands, potently enhanced ChAT activity in the septal neurons. These results suggest that TAK-147 may have neurotrophic activity on central cholinergic neurons, not via AChE inhibition but possibly via an effect on tau receptors.

A national HIV community cohort: design, baseline, and follow-up of the AmFAR Observational Database. American Foundation for AIDS Research Community-Based Clinical Trials Network.

This article describes the design, methodology, baseline distributions, and general follow-up characteristics of the American Foundation for AIDS Research (AmFAR) National Observational Database (ODB) Project including the benefits and limitations of collecting information on a large simple cohort in the HIV community setting. The study prospectively followed 15,611 HIV-positive men and women and collected longitudinal and cross-sectional data on demographics, medical conditions, drug therapies, laboratory parameters, and survival. Participants were followed between October 1990 and December 1993 by 252 community-based sites coordinated by 22 centers in the Community-Based Clinical Trials Network (CBCT Network) throughout the United States (including Puerto Rico) and Toronto, Canada. The ODB provided quantitative information on a national level needed to track the HIV epidemic and plan clinical trials conducted through the Network, and to provide sites with local databases to monitor patients and facilitate access to therapies in clinical trials. Overall, the ODB contains information on 1,925 women (12%) and 13,686 men (88%), 60% white, 20% African American, 17% Latino/Hispanic, with 56,254 baseline and follow-up forms, a median follow-up of about 12 months, a 16% loss-to-follow-up, and an 11% mortality rate. AmFAR plans to place the ODB in the public domain.

Design and baseline characteristics of the Veterans Affairs Non-Q-Wave Infarction Strategies In-Hospital (VANQWISH) trial. VANQWISH Trial Research Investigators.

OBJECTIVES: The Veterans Affairs Non-Q-Wave Infarction Strategies In-Hospital (VANQWISH) trial was designed to compare outcomes of patients with a non-Q wave myocardial infarction (NQMI) who were randomized prospectively to an early "invasive" strategy versus an early "conservative" strategy. The primary objective was to compare early and late outcomes between the two strategies using a combined trial end point (all-cause mortality or nonfatal infarction) during at least 1 year of follow-up. BACKGROUND: Because of the widely held view that survivors of NQMI are at high risk for subsequent cardiac events, management of these patients has become more aggressive during the last decade. There is a paucity of data from controlled trials to support such an approach, however. METHODS: Appropriate patients with a new NQMI were randomized to an early "invasive" strategy (routine coronary angiography followed by myocardial revascularization, if feasible) versus an early "conservative" strategy (noninvasive, predischarge stress testing with planar thallium scintigraphy and radionuclide ventriculography), where the use of coronary angiography and myocardial revascularization was guided by the development of ischemia (clinical course or results of noninvasive tests, or both). RESULTS: A total of 920 patients were randomized (mean follow-up 23 months, range 12 to 44). The mean patient age was 61 +/- 10 years; 97% were male; 38% had ST segment depression at study entry; 30% had an anterior NQMI; 54% were hypertensive; 26% had diabetes requiring insulin; 43% were current smokers; 43% had a previous acute myocardial infarction; and 45% had antecedent angina within 3 weeks of the index NQMI. CONCLUSIONS: Baseline characteristics were compatible with a moderate to high risk group of patients with an NQMI.

Anticoagulants in Takayasu's arteritis associated with crescentic glomerulonephritis and nephrotic syndrome: a case report.

The authors describe a 46-year-old Japanese woman who had Takayasu's arteritis associated with nephrotic syndrome due to mesangial proliferative glomerulonephritis with crescent. Although a few cases of focal and segmental mesangial proliferative glomerulonephritis associated with Takayasu's arteritis have been reported, nephrotic syndrome has not been reported previously in this situation.

A review of the design of vaccine efficacy trials and a proposal for the design of the VA Cooperative Study of Active Immunotherapy of HIV Infection.

We review the design of vaccine trials based on a search of the medical literature over the past four years, and present the proposed design of a therapeutic HIV vaccine efficacy study by the Department of Veterans Affairs Cooperative Studies Program. We explore the reasons for the atypical design of many vaccine trials, particularly the analysis of efficacy and how it differs from the more usual intent-to-treat analysis used in nonvaccine trials.

Esophageal mucosal eicosanoids in gastroesophageal reflux disease and Barrett's esophagus.

OBJECTIVE: Eicosanoids (prostaglandins and leukotrienes) may contribute to the clinical manifestations of gastroesophageal reflux disease (GERD). In this cross-sectional study, our purpose was to assess the role of leukotriene B4 (LTB4) and prostaglandin E2 (PGE2) in the clinical, endoscopic, and histological manifestations of GERD. METHODS: Using RIA, we measured ex vivo LTB4 and PGE2 content in esophageal mucosal biopsies from 141 patients with or without gastroesophageal reflux disease who underwent upper endoscopy. Patients were classified as normal symptomatic controls(n = 70), esophagitis stages 1-4 (n = 60), and Barrett's esophagus (n = 11), using clinical, endoscopic, histological, manometric, and esophageal 24-h ambulatory pH criteria. RESULTS: Mean LTB4 levels were significantly higher in both endoscopically and histologically identified erosive esophagitis and Barrett's esophagus patients, compared with normal controls. In contrast, PGE2 levels did not differ significantly among endoscopic or histological groups. When eicosanoid levels and composite symptom score (frequency score x severity score summed over five symptoms) were analyzed, no significant associations were found between LTB4 or PGE2 levels and the composite symptom score. There was no correlation between tissue eicosanoid levels and either the degree of esophageal acid exposure by ambulatory pH monitoring or the lower esophageal sphincter resting pressure as assessed by esophageal motility. Treatment with omeprazole 20 mg by mouth daily for 6 wk significantly reduced both LTB4 and PGE2 levels (p < 0.05) and was associated with significant improvement of symptoms and the endoscopic and histological appearance of the esophagus in 25 patients. CONCLUSIONS: These results suggest that LTB4, a prominent product of arachidonic acid metabolism in neutrophils, mediates the inflammatory phenomena of reflux esophagitis. The role of LTB4 and PGE2 in the induction of symptoms in patients with GERD and Barrett's esophagus remains unclear.

Purification and characterization of biologically active recombinant human neurotrophin-3 produced by expression of a chimera gene in Chinese hamster ovary cells.

In order to obtain high-level expression of recombinant human neurotrophin-3 (NT-3), we constructed several types of expression plasmids and examined several cell lines for expression of the human NT-3 gene. The highest level production of the recombinant protein was attained in Chinese hamster ovary cells transfected with an expression plasmid that contains a chimera gene encoding the human nerve growth factor (NGF) prepro-region and human NT-3 mature-region under control of a murine leukemia virus-derived long terminal repeat (MuLV-LTR). This cell line can produce more than 1 mg recombinant human NT-3/1 conditioned medium. The recombinant protein was purified to apparent homogeneity with a cation exchange column, a gel filtration column and a reversed-phase HPLC column with a recovery of about 30%. The purified NT-3, at a concentration as low as 0.2 ng/ml, induced neurite out-growth in neurons prepared from 8-day-old chick embryonic dorsal root ganglia; however, it showed little neurotrophic effect on rat PC12 pheochromocytoma cells, which are known to be NGF-responding cells. In addition, this protein promoted colony formation by human peripheral blood lymphocytes in soft agar culture.

Establishment of monoclonal antibodies against human nerve growth factor.

We have generated and characterized a monoclonal antibody to human nerve growth factor (hNGF). The monoclonal antibody NGFA-133 neutralizes hNGF activity, as assayed by neurite-outgrowth of nerve cells from chick embryonal dorsal root ganglion. Using this antibody, we have developed a sensitive and specific two-site enzyme immunoassay (EIA) system for hNGF. The assay is based on a sandwiching of the antigen between NGFA-133 coated on a microtiter plate and the same monoclonal antibody (NGFA-133) conjugated with horseradish peroxidase (HRP). The two-site EIA was sensitive enough to detect 920 fg/well of hNGF and did not cross-react either human neurotrophin-3 (hNT-3) or sodium dodecyl sulfate (SDS) denatured hNGF.

Loss of basic fibroblast growth factor in substantia nigra neurons in Parkinson's disease.

Basic fibroblast growth factor (bFGF) has a neurotrophic effect on mesencephalic dopaminergic neurons in vitro and in vivo. To explore whether an abnormality in bFGF expression occurs in Parkinson's disease (PD), we examined the substantia nigra (SN) of six PD and eight control cases immunohistochemically using a monoclonal antibody to bFGF. The mean number of melanin-positive neurons in sections of PD SN was 30.3% of the control mean, but the number of bFGF-immunopositive neurons was only 4.7% of the control mean. bFGF-immunoreactivity was present in only 8.2% of PD, but in 93.7% of control melanin-positive neurons. These results suggest a profound depletion of bFGF in surviving dopaminergic neurons of the SN in PD, and this depletion may be related to the disease process.

Detailed characterization of the biological activities of recombinant human nerve growth factor expressed in Chinese hamster ovary cells.

The biological activities of recombinant human nerve growth factor (rhNGF) produced by Chinese hamster ovary (CHO) cells that were transfected with human NGF gene were investigated in vitro and in vivo. rhNGF showed the same immunoreactivity as mouse NGF (mNGF) in a highly sensitive two-site enzyme immunoassay system employing mouse monoclonal antibody against mouse beta-NGF (MAb 27/21) for both the primary and the secondary antibodies. In PC12 cells, rhNGF promoted neurite extension and induced acetylcholinesterase (AChE) with the same potency as mNGF, showing an ED50 of 10-20 ng/mL. In fetal rat septal neurons cultured on a feeder layer of astroglial cells, rhNGF promoted survival and neurite extension as well as an increase in choline acetyltransferase (ChAT) activity and acetylcholine (ACh) content. At a maximal effective concentration of 30 ng/mL, rhNGF promoted a 1.4-, 2.8-, and 4-fold increase in surviving cell number, ACh content, and ChAT activity, respectively. rhNGF was five times more potent than mNGF for the increase in ChAT activity and ACh content showing an ED50 of 0.5 ng/mL, although the maximal response was the same for the two NGFs. Transection of the fimbria-fornix resulted in a loss of AChE-positive cells in the medial septum (MS) and vertical limb of the diagonal band of Broca (VDB). The administration of rhNGF or mNGF (3 or 30 micrograms in gel form) attenuated the loss of AChE-positive cells; rhNGF was as potent as or even more potent than mNGF. Radio frequency lesion of the basal forebrain (BF) including the nucleus basalis magnocellularis (NBM) resulted in severe impairment of memory and/or learning in passive avoidance and Morris' water maze tasks. Repeated injection of rhNGF (5 micrograms x 5 over 2 wk) into the lateral ventricle ameliorated the behavioral impairment in the water maze task but not in passive avoidance. rhNGF treatment increased ChAT activity in the frontal cortex and even in other subregions of the cerebral cortex where ChAT activity was not decreased by BF lesion. These results indicate that human NGF can be measured in an enzyme immunoassay system using monoclonal antibody against mNGF (MAb 27/21) and that rhNGF has potent biological activity, comparable to or greater than mNGF, both in vitro and in vivo.