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PubMed1981

Bioassay of a new aldosterone antagonist and evaluation of a simple method of quantitative comparison.

The renal antimineralocorticoid activity of single oral doses of a new aldosterone antagonist OH OPC(ME)-K was compared to that of spironolactone in two studies in healthy men. OH OPC(ME)-K reversed the urinary electrolyte response to fludrocortisone in the period up to 16 hr after treatment, but it was less potent than spironolactone on a weight basis. The best estimate of the relative potency of OH OPC(ME)-K: spironolactone (derived from a simple protocol using equal single doses of the two drugs) was 0.60:1 (95% confidence limits 0.24:1 to 1.42:1), in good agreement with the estimate from a more complex three-dose parallel-line bioassay (0.61:1, 95% confidence limits 0.48:1 to 0.79:1). The results of simple single-dose studies can be used, with certain assumptions, to provide a useful estimate of the relative potency of new aldosterone antagonists at an early stage of development.

Double-Blind Method↗
PubMed1986

The relationship between mean abdominal diameter and femur length in normal and impaired fetal growth.

The relationship of fetal mean abdominal diameter (MAD) to fetal femur length (FL) in clinically normal pregnancies and 37 cases of intrauterine growth retardation (IUGR) was studied. The normal relationship of FL to MAD is closely described by the equation: log (MAD) = 3.326 + (0.185 X FL). r = .953, P less than .001. In the growth retarded infants, 59% of the abdominal measurements fell below the lower 75% confidence limit. Of the abdominal measurements derived from infants with birthweight greater than 2 SD below the mean for gestational age, 86% fell below the lower 75% confidence limit. These data show the MAD is selectively depressed in many, but not all cases of IUGR and particularly in the more severely affected infant, but the technique is not sufficiently discriminant to be used by itself for the detection of IUGR. Detection of an anomaly of this relationship would be strong supportive evidence of IUGR independent of gestational age and possibly identifies infants growth retarded specifically due to chronic deprivation.

Abdomen↗
PubMed1988

Lack of relation of increased malformation rates in infants of diabetic mothers to glycemic control during organogenesis.

To determine how much insulin-dependent diabetes increases a woman's risk of giving birth to a malformed infant and how that risk is influenced by metabolic control, we followed 347 diabetic and 389 control women who enrolled in the study within 21 days of conception (the early-entry group) and 279 diabetic women who entered later (the late-entry group). We detected major malformations in the infants of 4.9 percent of the early-entry diabetic women, 2.1 percent of the controls, and 9.0 percent of the late-entry diabetic women. Malformation rates were significantly higher among offspring of early-entry diabetic women than among those of controls (odds ratio, 2.45; lower one-sided 95 percent confidence limit, 1.12; P = 0.027), and higher among late-entry than among early-entry diabetic women (odds ratio, 1.91; lower one-sided 95 percent confidence limit, 1.07; P = 0.032). Mean blood glucose and glycosylated hemoglobin levels during organogenesis were not significantly higher in women whose infants were malformed. Hypoglycemia (glucose, less than or equal to 50 mg per deciliter [2.8 mmol per liter]) was not significantly more common in the same group. Hyperglycemia and glycosylated hemoglobin were not correlated with malformation. The data suggest that more sensitive measures are needed to identify the teratogenic mechanisms, or that not all malformation can be prevented by good glycemic control. Despite the increased malformation rate among infants of the early-entry diabetic women, as compared with the controls, the more favorable outcome seen in the former group as compared with the late-entry group justifies the attempt to achieve good metabolic control around the time of conception.

Blood Glucose↗
PubMed2005

Active and passive cigarette smoking and the risk of cervical neoplasia.

OBJECTIVE: Evidence links active cigarette smoking to cervical neoplasia, but much less is known about the role of passive smoking. Using a prospective cohort design, we examined personal cigarette smoking and household passive smoke exposure in relation to the risk of cervical neoplasia. METHODS: Cohorts were established based on data collected on the smoking status of all household members during private censuses of Washington County, Maryland in 1963 (n = 24,792) and 1975 (n = 26,381). Using the Washington County Cancer Registry, the occurrence of cervical neoplasia in the two cohorts was ascertained from 1963-1978 and from 1975-1994. Poisson regression models were fitted to estimate the relative risk of developing cervical neoplasia associated with active and passive smoking in both cohorts. The referent category for all comparisons was never smokers not exposed to passive smoking. RESULTS: The adjusted relative risk and 95% confidence limits for passive smoking was 2.1 (1.3, 3.3) in the 1963 cohort and 1.4 (0.8, 2.4) in the 1975 cohort. The adjusted relative risk and 95% confidence limits for current smoking were 2.6 (1.7, 4.1) and 1.7 (1.1, 2.6) in the 1963 and 1975 cohort, respectively. CONCLUSION: The associations were in the direction of increased risk for both passive smoking and current active smoking in both the 1963 and 1975 cohorts, but were stronger in the 1963 cohort. The results of this long-term, prospective cohort study corroborate the association between active cigarette smoking and cervical neoplasia and provide evidence that passive smoking is a risk factor for cervical neoplasia.

Adult↗
PubMed2000

Cost analysis of nurse telephone consultation in out of hours primary care: evidence from a randomised controlled trial.

OBJECTIVE: To undertake an economic evaluation of nurse telephone consultation using decision support software in comparison with usual general practice care provided by a general practice cooperative. DESIGN: Cost analysis from an NHS perspective using stochastic data from a randomised controlled trial. SETTING: General practice cooperative with 55 general practitioners serving 97 000 registered patients in Wiltshire, England. SUBJECTS: All patients contacting the service, or about whom the service was contacted during the trial year (January 1997 to January 1998). MAIN OUTCOME MEASURES: Costs and savings to the NHS during the trial year. RESULTS: The cost of providing nurse telephone consultation was 81 237 pound sterling per annum. This, however, determined a 94 422 pound sterling reduction of other costs for the NHS arising from reduced emergency admissions to hospital. Using point estimates for savings, the cost analysis, combined with the analysis of outcomes, showed a dominance situation for the intervention over general practice cooperative care alone. If a larger improvement in outcomes is assumed (upper 95% confidence limit) NHS savings increase to 123 824 pound sterling per annum. Savings of only 3728 pound sterling would, however, arise in a scenario where lower 95% confidence limits for outcome differences were observed. To break even, the intervention would have needed to save 138 emergency hospital admissions per year, around 90% of the effect achieved in the trial. Additional savings of 16 928 pound sterling for general practice arose from reduced travel to visit patients at home and fewer surgery appointments within three days of a call. CONCLUSIONS: Nurse telephone consultation in out of hours primary care may reduce NHS costs in the long term by reducing demand for emergency admission to hospital. General practitioners currently bear most of the cost of nurse telephone consultation and benefit least from the savings associated with it. This indicates that the service produces benefits in terms of service quality, which are beyond the reach of this cost analysis.

Acute Disease↗
PubMed2005

Blunt cerebrovascular injury in patients with blunt multiple trauma: diagnostic accuracy of duplex Doppler US and early CT angiography.

PURPOSE: To retrospectively evaluate the frequency of blunt cerebrovascular injury (BCVI) in patients with multiple trauma and to retrospectively compare the diagnostic accuracy of duplex Doppler ultrasonography (US) and computed tomographic (CT) angiography by using clinical follow-up and subsequent imaging as reference standards. MATERIALS AND METHODS: The institutional review board approved this study; informed consent was not required. Charts and images of consecutive patients treated for multiple trauma (injury severity score, >16) between January 1998 and October 2003 were reread by an experienced radiologist. Until October 2002, subjects were screened for BCVI with US. Since November 2002, patients underwent CT angiography of the carotid and vertebral arteries. Sensitivity and specificity of US and CT angiography were calculated with 95% confidence intervals (CIs). RESULTS: The early cohort included 1471 patients (mean age, 35.8 years +/- 17.7 [standard deviation]), and the late cohort included 407 patients (mean age, 39.2 years +/- 18.8). US depicted five blunt vessel injuries but later missed another eight, which led to cerebral ischemia. With a BCVI frequency of 0.9%, sensitivity and specificity of US were 38.5% (95% CI: 13.9%, 68.4%) and 100% (lower 95% confidence limit, 99.7%), respectively. In the second cohort, the BCVI rate was 2.7%. CT angiography depicted BCVI in 11 patients, with a sensitivity of 100% (lower 95% confidence limit, 71.5%), but produced one false-positive result. CONCLUSION: Injuries to the cervical arteries among blunt trauma patients are more common than previously reported. Duplex Doppler US has inadequate sensitivity to help rule out this condition. The notable morbidity with missed dissections warrants routine contrast material-enhanced studies of the carotid and vertebral vessels if patients are scheduled for CT of the cervical spine.

Adult↗
PubMed1981

Sensitivity and specificity of hemodynamic criteria in the diagnosis of acute right ventricular infarction.

To test the sensitivity and specificity of hemodynamic criteria for acute right ventricular infarction (RVI), two groups of patients with anatomically proved acute myocardial infarction and hemodynamic monitoring were studied. Group A included 22 patients acute RVI and group B, 38 with infarction confined to the left ventricle. In both groups, the closest relation between right atrial and pulmonary capillary pressures (RAP and PCP), as well as the presence of a severe noncompliant pattern (SNCP), were studied. A SNCP was defined as a y descent deeper than the x descent in RAP. RAP was equal to or higher than PCP in 10 patients from group A and in none from group B. In group B, a significant relation was found between RAP and PCP (r = 0.777, y = 0.43x + 0.18) (p less than 0.05), and the 95% confidence limits could be calculated. Above these limits, a closer relation between RAP and PCP was only found in patients with RVI. However, six patients with RVI showed an RAP/PCP relation within 95% confidence limits of group B (sensitivity 72.7%, specificity 100%). A SNCP was present in 12 patients with RVI and only in one without RVI (p less than 0.01) (sensitivity 54.5% and specificity 97.4%). When either criterion is present (close relation between RAP and PCP or SNCP), a high sensitivity (81.8%) and specificity (97.4%) can be achieved in the diagnosis of acute RVI.

Acute Disease↗
PubMed1995

Diagnostic sensitivity of motor nerve conduction studies in ulnar neuropathy at the elbow.

Seventy-six patients with ulnar neuropathy at the elbow were divided into 3 classes (Grades I, II, and III) according to their clinical features and the maximal motor nerve conduction velocity (MCV), and the amplitude ratios at the across-elbow segment were retrospectively analyzed. To determine the criteria for abnormality, a control study was conducted on 150 healthy volunteers ranging in age from 20 to 89 years (6 age groups). The normal value for MCV could be set for two age groups: those under 60 and those over 60 years old. The 95% confidence limit was 54m/s for the former and 50m/s for the latter. There was no statistically significant difference in the amplitude ratio among the age groups. The confidence limit was set uniformly at 0.82 (above elbow/below elbow). An abnormality in either MCV or the amplitude ratio was found in 66.7% of Grade I (recent and mild symptoms), 89.7% of Grade II (persistent symptoms), and 100% of Grade III cases (marked intrinsic muscle atrophy). Evaluation using the combination of MCV and the amplitude ratio, considering the age-related normal value, appeared to be useful in establishing a differential diagnosis of ulnar neuropathy at the elbow.

Adult↗
PubMed1988

Diagnostic value of ascitic fluid cholesterol levels in the prediction of malignancy.

In a prospective study abdominal paracentesis with ascitic fluid aspiration was performed in 54 consecutive patients with ascites of unknown cause. The ascitic fluid was examined cytologically and bacteriologically. The total cholesterol concentration was measured with an enzymatic colorimetric method. Malignant disease was diagnosed in 34 patients. Two of them had both malignant disease and liver cirrhosis and were excluded. Seventeen patients had liver cirrhosis, one had acute pancreatitis, and two had decompensated heart disease. The diagnostic value of an ascitic cholesterol concentration greater than 1.2 mmol/l in terms of predicting malignant disease was 87.5% (95% confidence limits, 71.0-96.5). The predictive value of an ascitic cholesterol concentration less than or equal to 1.2 mmol/l in terms of benign disease was 80.0% (95% confidence limits, 56.3-94.3). It is concluded that ascitic cholesterol measurement is a valuable supplement to cytologic examination in distinguishing between ascites of malignant and benign origin.

Adult↗
PubMed1991

[Assessment of micturition cystourethrography. Intra- and inter-observer variation].

The reliability of any method of investigation depends upon the accuracy and reproducibility of the results of the investigation. The accuracy of voiding cystoureterography (VCU) which is greatly dependent on the radiographic assessment cannot be assessed because no standard answers exist. The reliability of the method may be assessed in the form of intra- and inter-observer variations. VCU investigations from 24 women with incontinence were assessed by two independent radiologists. Fifteen of the radiological examinations had previously been described by one of the radiologists so that intra-observer variation could be assessed by these. Inter-observer variation was 70% (95% confidence limits 51-89%), calculated from the diagnoses anterior and posterior suspension defects, combined defects and normal conditions. The corresponding intra-observer variation was 53% (95% confidence limits 27-78%). The radiographic criteria for subdivision of suspension defects into anterior and posterior defects are, theoretically, very simple but appear to be difficult to attain in practice. The indications for employing a form of examination where assessment of the result of examination is so obscure should be very weighty.

Adult↗
PubMed1988

Long-term (5-year) results after either horizontal gastroplasty or very-low-calorie diet for morbid obesity.

Fifty-seven patients allocated at random to either diet supported by gastroplasty or very-low-calorie diet (VLCD) were followed for 5 years. One patient was lost to follow-up 1 year after surgery. Data were analyzed by survival statistics and success was liberally defined as a maintained weight loss of at least 10 kg. The cumulative success rate declined steadily in both groups, but it remained higher in the gastroplasty group (16 versus 3 percent, the 95 percent confidence limits being 11-21 percent and 1-5 percent, respectively; P less than 0.05). At 5 years, eight of 27 gastroplasty patients (30 percent, 95 percent confidence limits 14-50 percent) had not relapsed. Of 30 VLCD patients, relapse had not occurred in five (17 percent, 6-35 percent). The weight loss of patients without relapse did not differ significantly (medians of gastroplasty and VLCD patients 18 kg and 27 kg, respectively). Complications and side-effects were more numerous and serious among the gastroplasty patients. Although in this long-term study, the horizontal gastroplasty proved to be somewhat more effective than the diet alone, the surgical risks and the unsatisfactory maintenance of weight loss speak against the use of this operation.

Adult↗
PubMed1987

Pregnancy outcomes after first-trimester vaginitis drug therapy.

Prescription frequencies in the first trimester were compared for miconazole, clotrimazole, nystatin, candicidin, aminacrine compounds, and metronidazole before deliveries involving congenital anomalies versus those not linked to congenital anomalies. Prescriptions before spontaneous abortions were compared with those in the first trimester of deliveries and with those before legal abortions. No statistically significant association was observed with any of these agents for the overall frequency of birth defects or for specific birth defects analyzed (cardiovascular defects, oral clefts, and spina bifida). Two hundred fifty miconazole exposures among 4264 spontaneous abortions, compared with 2236 in the first trimester of 55,736 deliveries, provided an estimated relative risk of 1.4 (95% confidence limits 1.2-1.5). One hundred twelve treatments with clotrimazole among the spontaneous abortions, compared with 1086 among the deliveries, provided a relative risk of 1.4 (95% confidence limits 1.1-1.6). In contrast, large numbers of exposures to nystatin and aminacrine compounds did not show this association, suggesting that spontaneous abortions are caused by the imidazole agents miconazole and clotrimazole rather than the condition being treated. Because many associations were examined without previous hypotheses, and because the data were inadequate to show an elevated risk for clotrimazole when comparing spontaneous with legal abortion exposures, these findings are considered to be a signal for further studies rather than definitive in themselves.

Abnormalities, Drug-Induced↗
PubMed1999

Air pollution and hospital admissions for heart disease in eight U.S. counties.

This study examines the consistency of the association between particulate matter less than 10 microm in aerodynamic diameter (PM10), carbon monoxide (CO), and hospital admissions for cardiovascular disease across eight urban counties with different levels of correlation between pollutants and between the pollutants and weather. I fit Poisson regression models controlling for day-of-week effects and using nonparametric smoothing to control for season and weather. Daily variation in PM10 was associated with hospital admissions for heart disease in the elderly (2.48% increase, for an interquartile range increase in exposure; 95% confidence limits = 1.82%, 3.15%). Daily variation in CO was also associated with admissions (2.79% increase, for an interquartile range (1.75 parts per million) increase in exposure; 95% confidence limits = 1.89%, 3.68%). These associations held in both humid and dry locations and were independent of the correlation between the pollutants and weather or other pollutants. The effect size estimates for PM10 and CO likewise showed no association with their correlation in each location, as one would expect if one pollutant were merely a proxy for the other. The PM10 effects are consistent with recent animal data showing cardiovascular effects and with preliminary human data showing effects on heart rate variability and plasma viscosity. The CO results are consistent with literature on angina exacerbations.

Aged↗
PubMed1986

Parity and breast cancer risk: possible effect on age at diagnosis.

We examined the effect of parity on breast cancer risk on the basis of information from 107,146 married female nurses followed prospectively between 1976-1980. For everparous women, a significant protective effect against breast cancer was observed with increasing parity (chi 12 for trend = 14.2, p less than 0.001). Adjustment for age at first birth and other potential confounders by multiple logistic regression did not materially affect this trend. After controlling for these risk factors, the overall relative risk of breast cancer for women with four or more pregnancies lasting 6 months or longer was 0.68 (95% confidence limits 0.51-0.90) compared with women with only one pregnancy. When nulliparous and everparous women were compared, an interaction of age and everparous status in 1976 was observed. The logistic regression coefficient for the interaction was 0.3419 (95% confidence limits 0.0374-0.6464). Specifically, for women of parity 2 relative to nulliparous, the relative risk of breast cancer and the 95% confidence intervals were 1.85 (1.09, 3.14), 1.32 (0.92, 1.89), and 0.93 (0.62, 1.41) for 30-39, 40-49 and 50-55-year-old women, respectively. This points to the need of presenting age-specific, rather than age-adjusted, relative risks in future studies of breast cancer and parity.

Adult↗
PubMedDate not supplied

Spinal anesthesia reduces oxygen consumption in diabetic patients prior to peripheral vascular surgery.

BACKGROUND AND OBJECTIVES: The purpose of this study was to evaluate the effect of spinal anesthesia in VO2 in a uniform high-risk patient population and also the relationship between dermatomal level of block and VO2, neither of which has been investigated previously. METHODS: The effect of spinal anesthesia on VO2 was studied in 17 diabetic patients undergoing lower limb peripheral vascular surgery. Measurements were made before and 15 minutes after administration of a tetracaine spinal anesthetic. Values for VO2 and oxygen delivery (DO2) were derived from cardiac output as measured by thermodilution, hemoglobin concentration, and arterial and mixed venous blood gas analysis. The dermatomal level of the sensory block was determined by use of a hand-held nerve stimulator. RESULTS: Mean VO2 decreased by 27.7% (P = .001) (95% confidence limits, decrease of 22.4-90.4%). Mean DO2 and arterial blood gases were unchanged, and the mean postspinal oxygen extraction ratio (VO2/DO2) decreased by 20.5% (P = .002) (95% confidence limits, decrease of 9.1-32.3%). There was a relationship between changes in VO2 and sensory block height (P = .029). CONCLUSIONS: Spinal anesthesia in diabetic patients is associated with a reduction in VO2, the extent of which appears to be, at least in part, a function of the level of spinal sensory block.

Adult↗
PubMed1997

Uncertainty and variability in updated estimates of potential dose and risk at a U.S. nuclear test site--Bikini Atoll.

Uncertainty and interindividual variability were assessed in estimated doses for a rehabilitation scenario for Bikini Island at Bikini Atoll, in which the top 40 cm of soil would be removed in the housing and village area, and the rest of the island would be treated with potassium fertilizer, prior to an assumed resettlement date of 1999. Doses were estimated for ingested 137Cs and 90Sr, external gamma-exposure, and inhalation+ingestion of 241Am + 239+240Pu. Two dietary scenarios were considered: imported foods are available (IA); imported foods are unavailable with only local foods consumed (IUA). After approximately 5 y of Bikini residence under either IA or IUA assumptions, upper and lower 95% confidence limits on interindividual variability in calculated dose were estimated to lie within a approximately threefold factor of its in population-average value; upper and lower 95% confidence limits on uncertainty in calculated dose were estimated to lie within a approximately twofold factor of its expected value. For reference, the expected values of population-average dose at age 70 y were estimated to be 16 and 52 mSv under IA and IUA dietary assumptions, respectively. Assuming that 200 Bikini resettlers would be exposed to local foods (under both IA and IUA assumptions), the maximum 1-y dose received by any Bikini resident is most likely to be approximately 2 and 8 mSv under the IA and IUA assumptions, respectively. Under the most likely dietary scenario, involving access to imported foods, this analysis indicates that it is most likely that no additional cancer fatalities (above those normally expected) would arise from the increased radiation exposures considered.

Animals↗
PubMed2006

Comparison of cancer slope factors using different statistical approaches.

The U.S. Environmental Protection Agency's cancer guidelines (USEPA, 2005) present the default approach for the cancer slope factor (denoted here as s*) as the slope of the linear extrapolation to the origin, generally drawn from the 95% lower confidence limit on dose at the lowest prescribed risk level supported by the data. In the past, the cancer slope factor has been calculated as the upper 95% confidence limit on the coefficient (q*1) of the linear term of the multistage model for the extra cancer risk over background. To what extent do the two approaches differ in practice? We addressed this issue by calculating s* and q*1 for 102 data sets for 60 carcinogens using the constrained multistage model to fit the dose-response data. We also examined how frequently the fitted dose-response curves departed appreciably from linearity at low dose by comparing q1, the coefficient of the linear term in the multistage polynomial, with a slope factor, sc, derived from a point of departure based on the maximum likelihood estimate of the dose-response. Another question we addressed is the extent to which s* exceeded sc for various levels of extra risk. For the vast majority of chemicals, the prescribed default EPA methodology for the cancer slope factor provides values very similar to that obtained with the traditionally estimated q*1. At 10% extra risk, q*1/s* is greater than 0.3 for all except one data set; for 82% of the data sets, q*1 is within 0.9 to 1.1 of s*. At the 10% response level, the interquartile range of the ratio, s*/sc, is 1.4 to 2.0.

Biological Assay↗
PubMed2003

Neuraminidase sequence analysis and susceptibilities of influenza virus clinical isolates to zanamivir and oseltamivir.

The influenza virus neuraminidase (NA) inhibitors zanamivir and oseltamivir were introduced into clinical practice in various parts of the world between 1999 and 2002. In order to monitor the potential development of resistance, the Neuraminidase Inhibitor Susceptibility Network was established to coordinate testing of clinical isolates collected through the World Health Organization influenza surveillance network from different regions of the world (M. Zambon and F. G. Hayden, Antivir. Res. 49:147-156, 2001). The present study establishes the baseline susceptibilities prior to and shortly after the introduction of the NA inhibitors. Over 1000 clinical influenza isolates recovered from 1996 to 1999 were tested. Susceptibilities were determined by enzyme inhibition assays with chemiluminescent or fluorescent substrates with known NA inhibitor-resistant viruses as controls. The 50% inhibitory concentrations (IC(50)s) depended upon the assay method, the drug tested, and the influenza virus subtype. By both assays, the mean zanamivir IC(50)s were 0.76, 1.82, and 2.28 nM for the subtype H1N1 (N1), H3N2 (N2), and B NAs, respectively, and the oseltamivir IC(50)s were 1.2, 0.5, and 8.8 nM for the N1, N2, and B NAs, respectively. The drug susceptibilities of known zanamivir- and oseltamivir-resistant viruses with the NA mutations E119V, R292K, H274Y, and R152K fell well outside the 95% confidence limits of the IC(50)s for all natural isolates. Sequence analysis of the NAs of viruses for which the IC(50)s were above the 95% confidence limits and several control isolates for which the IC(50)s were in the normal range revealed variations in some previously conserved residues, including D151, A203, T225, and E375 (N2 numbering). Known resistance mutations are both influenza virus subtype and drug specific, but there was no evidence of naturally occurring resistance to either drug in any of the isolates.

Acetamides↗