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PubMed1999

Cigarette smoking and effects on menstrual function.

OBJECTIVE: To examine the relationship between smoking and menstrual function, using biologic measures rather than self-report of menstrual cycle characteristics. METHODS: In a prospective study, 408 women collected urine daily for one to seven menstrual segments (cycles), maintained daily diaries, and completed detailed interviews. Smoking data from the diaries were averaged over each segment and verified by cotinine assay. Urine samples were analyzed for metabolites of steroid hormones to define the day of ovulation and various menstrual characteristics, including: 1) segment, follicular, luteal phase, and menses length, 2) variability, and 3) anovulation. RESULTS: Heavy smoking (at least 20 cigarettes per day) was associated with nearly four times the risk of short segment (less than 25 days) as was nonsmoking (adjusted odds ratio 3.8, 95% confidence limits 1.1, 12.7). Mean segment length was on average 2.6 days shorter with heavy versus no smoking (95% confidence limits 0.14, 5.0), due almost entirely to shortening of the follicular phase. Women who smoked an average of ten or more cigarettes per day had significantly more variable segment and menses lengths than nonsmokers. Based on small numbers, the data suggested that with greater smoking, there was a possible increased risk of anovulation and short luteal phase. Segments of exsmokers with ten or more pack-years of exposure were more likely to be short and have shorter luteal phases than those of never smokers. CONCLUSION: The effects found in this study of smoking on the menstrual cycle might explain in part associations of smoking with other reproductive endpoints, such as subfecundity and early menopause.

Adolescent↗
PubMed1992

The role of herd immunity in an epidemic cycle of hepatitis A.

An epidemic of hepatitis A took place in Northern Ireland between 1984 and 1990. All ages of persons and geographical areas were involved. Children aged 5-14 years with Belfast addresses were particularly affected. Serologically confirmed cases in this group rose from five cases in 1984 to 93 cases in 1987 and fell to 19 cases in 1990. Of 100 samples of serum of Belfast children aged 5-14 years in late 1985, 23 were hepatitis A IgG positive, 95% confidence limits being 15.2-32.5. Of 100 similar children in late 1989, 19 were hepatitis A IgG positive, 95% confidence limits being 11.8-28.1. Thus a substantial rise in herd immunity may not be necessary for the ending of such an epidemic in a society with good housing and sanitation.

Adolescent↗
PubMed1997

Tumor control probability of nasopharyngeal carcinoma: a comparison of different mathematical models.

PURPOSE: Radiation dose and tumor volume are factors known to affect the local control of a given type of tumor. Local tumor control is a major factor to consider when a treatment plan is evaluated. This article reports the correlation between tumor control probability, dose, and volume in a retrospective study of 142 patients with nasopharyngeal carcinoma (NPC). METHODS AND MATERIALS: The tumor volume was outlined and calculated from a computed tomographic scan. Patients were categorized according to tumor volume and radiation dose received in treatment. Local control rate was calculated for each category by the Kaplan-Meier method. Mathematical models were fitted to correlate the local control rate, dose, and volume. Both empirical and mechanistic approaches were attempted; the former included logistic models with two and three parameters, and the latter, the formulation from Brenner and Bentzen with a radiobiological basis. RESULTS: Brenner's model estimated alpha at 0.041 Gy(-1) with 95% confidence limits (-0.032, 0.113) Gy(-1). The volume dependent constant h was estimated at 0.160 cm(-3) with 95% confidence limits (-0.729, 1.048) cm(-3). The Pearson correlation coefficient was 0.64. The magnitude and sign of the fitted parameters were reasonable and consistent with reported clinical experience. The other models were fitted with slightly better goodness of fit (r = 0.65 - 0.68), but with less interpretable parameters. CONCLUSION: Brenner's model is considered appropriate for a description of the dose and volume effect on the local control of the NPC. It could be used in combination with normal tissue complication probability for treatment plan evaluation to optimize treatment results.

Adult↗
PubMed1993

Analgesic efficacy and potency of two oral controlled-release morphine preparations.

MS Contin tablets and Oramorph SR tablets are two forms of oral controlled-release morphine sulfate available for the alleviation of pain. Our objective was to compare their analgesic effects in a relative potency assay. In this study, 151 patients undergoing caesarean section or abdominal hysterectomy and reporting moderate or severe postoperative pain received a 30 or 90 mg dose of either drug in a balanced, randomized, double-blind, parallel-group, single-dose experimental design. Patients provided self-ratings of analgesia. Relative potency for pain relief were calculated from log dose-effect curves. For total pain relief (rated by visual analog scales) over 12 hours, the log dose relative potency estimate for MS Contin tablets/Oramorph SR tablets was 1.9 (95% confidence limits, 0.89 to 11.1); for peak pain relief (visual analog scales) the relative potency estimate was 1.7 (95% confidence limits, 0.65 to 48.3). Overall, the 90 mg dose of MS Contin was more effective than 30 or 90 mg doses of Oramorph SR and the 30 mg dose of MS Contin at hours 6 to 12. Adverse experiences (mainly drowsiness) were mostly mild to moderate, with no significant differences in their overall incidence or severity between equivalent doses. MS Contin tablets provided greater peak, total, and duration of analgesia, without higher incidence of adverse experiences.

Administration, Oral↗
PubMed2002

Lower risk for alcohol-induced cirrhosis in wine drinkers.

Although there is a well-known relationship between total alcohol intake and future risk for cirrhosis, other factors such as the type of alcohol consumed are sparsely studied. The aim of this study was to assess the effects of wine compared with other types of alcoholic beverages on risk for alcohol-induced cirrhosis. In 3 prospective studies, 30,630 participants from the Copenhagen area were followed-up for a total observation time of 417,325 person-years. Information on weekly intake of beer, wine, and spirits, and sex, age, body mass index, smoking habits, and education was obtained from questionnaires. The primary outcome measures were first admission or death, with alcohol-induced cirrhosis obtained from death certificates and from the National Hospital Discharge Register. Data were analyzed by means of multiplicative Poisson regression models. We confirmed the increasing risk for cirrhosis with increasing alcohol intake. Individuals who drank more than 5 drinks per day had a relative risk of 14 to 20 for developing cirrhosis compared with non- or light drinkers. However, compared with individuals who drank no wine (relative risk set at 1.0), individuals drinking 16% to 30% wine of their total intake had a relative risk of 0.4 (95% confidence limits, 0.3-0.6) and those drinking 51% or more of wine had a relative risk of 0.3 (95% confidence limits, 0.2-0.5) for developing cirrhosis. In conclusion, the results suggest that a high intake of all 3 types of alcohol conveys an increased risk for cirrhosis, but wine drinkers are at a lower risk than beer and spirits drinkers.

Adult↗
PubMed1991

Testing for consistency in a single multicenter trial.

One of the criteria for demonstrating efficacy in a single multicenter trial is that the centers are consistent with respect to the direction and significance of results. The purpose of this research is to discuss the use of the noncentrality parameter delta of an F distribution as a means of testing for the consistency of treatment effects across centers. We state the testing problem as H0: (delta > delta 0) versus H1: (delta < or = delta 0), where delta 0 is prespecified, so that H0 represents inconsistency and H1 consistency. Thus, strong evidence from the sample data is required in order to conclude that the treatment effects are consistent across centers. We discuss reasonable choices for delta 0 and develop the alpha-level, uniformly most powerful and unbiased test, which is equivalent to rejecting H0 if the 100(1 - alpha)% uniformly most accurate and unbiased upper confidence limit for delta is less than or equal to delta 0. We examine other tests based on upper confidence limits, such as those calculated from linear estimators of delta and those calculated from a likelihood approach. We investigate the performance of the tests in a small simulation study and present an example from a four-center clinical trial.

Humans↗
PubMed1988

Efficacy of Haemophilus influenzae type b capsular polysaccharide vaccine.

The efficacy of the Haemophilus influenzae type b (Hib) polyribose phosphate vaccine was evaluated in a population of 120,000 children from 23 through 71 months of age in the Kaiser Permanente Medical Care Program (KPMCP) in Northern California over the 2-year period from June 1, 1985, through May 31, 1987. Approximately 37% of the population were vaccinated by the end of the first year and 60% were vaccinated by the end of the second year. There were 35 cases of Hib disease, 4 of whom were vaccine failures. Cases of Hib disease were identified by multiple modality case ascertainment, consisting of: (1) active surveillance in KPMCP microbiology laboratories; (2) active surveillance on KPMCP pediatric wards by a study physician; (3) retrospective review of computer-stored hospital discharge diagnoses; and (4) a review of all hospitalizations outside the health plan. The medical records of cases, matched controls and a random sample of the population were reviewed to obtain information on vaccination and related variables. Efficacy was evaluated using two complementary methods. In a retrospective surveillance approach, efficacy was estimated to be 68% (95% confidence limits of 4, 89%). In a matched case-control analysis, efficacy was estimated to be 69% (95% confidence limits of -13, 91%). Adjustment for day care attendance and parental occupation slightly reduced the efficacy estimate. Other possible confounders including race, parental education and number of siblings were considered. Four cases of Hib disease were observed within 1 week following receipt of vaccine and before the time when immunity could have developed. There are several plausible explanations for the occurrence of these early cases including the possibility of chance alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacterial Capsules↗
PubMed1998

High incidence of the Cys 282 Tyr mutation in the HFE gene in the Irish population--implications for haemochromatosis.

A simple PCR-SSOP approach based on a single PCR product has been developed to screen the HFE gene for the haemochromatosis-associated mutations Cys 282 Tyr and His 63 Asp. Using this approach the prevalence of these mutations in a cohort (30) of haemochromatosis patients and normal controls (404) was determined. Ninety percent of the haemochromatosis patients were homozygous for the Cys 282 Tyr mutation. In the normal population we found an increased incidence of the Cys 282 Tyr mutation (17.3%; 95% confidence limits 0.136-0.209) which was also reflected in the higher frequency of Cys 282 Tyr homozygotes (1.24%; 95% confidence limits 0.0016-0.0232). Linkage disequilibrium analysis confirmed the association between A*03 and Cys 282 Tyr. However, strong linkage disequilibrium occurred with the HLA-A*03-associated allele HLA-B*14 but not the HLA-A*03-associated allele HLA-B*07. The His 63 Asp was found to be in linkage disequilibrium with HLA-A*29.

Cysteine↗
PubMed2000

Predictors of final adult height after renal transplantation during childhood: a single-center study.

AIM: Assessment of final adult height and its predictive factors in children transplanted (RTx) and followed up in a single center. METHODS: A cohort of 32 patients (17 boys, 15 girls) who received RTx before the age of 15 years and had reached a final adult height was selected. Twenty patients received a single RTx, 9 patients received two RTx, and 3 patients received three RTx. Seven children were transplanted preemptively, while the remaining 25 children received peritoneal dialysis for relatively short periods of time. In 11 patients, recombinant human growth hormone (rhGH) was administered either before (n = 8) or after (n = 3) RTx. RESULTS: In 13 patiens (41%), the final height standard deviation score for chronological age (hSDS) was -2.3+/-0.5, below the 95% confidence limits for target height (group A), while in 19 patients (59%), it was -0.7+/-0.8, within the 95% confidence limits for target height (group B). The hSDS values at the start of dialysis and at the time of first RTx were significantly lower in group A than in group B. A higher hSDS at the start of dialysis and at the time of first RTx had a significant positive influence on the final height (FH), whereas a longer duration of dialysis had a significant negative effect on the FH. Administration of rhGH after RTx played an important role in the achievement of a normal FH in 3 girls. No differences were observed between group A and B with respect to age at start of dialysis, chronological or bone age at first RTx, number of rejection episodes, duration of the study period from last RTx to FH, glomerular filtration rate during this study period, or percentage of time on prednisone therapy. CONCLUSIONS: The FH is almost exclusively predetermined by the height achieved at the start of dialysis and at the time of first RTx. Therefore, to reach target adult height after RTx, the best strategy is to shorten the time of dialysis and to start rhGH administration at a young age and as early as possible during the course of chronic renal failure. Administration of rhGH after RTx is also highly effective, but, given its potential danger, still remains a matter of investigation.

Adolescent↗
PubMed1991

Lead in the placenta, membranes, and umbilical cord in relation to pregnancy outcome in a lead-smelter community.

As part of a cohort study of the effects of chronic exposure to lead on pregnancy outcome and child development, lead concentrations in the umbilical cord and placental tissues (body and membranes) from 9 late fetal deaths, 23 preterm births, and 18 births associated with premature rupture of the amniotic membranes were compared with the lead concentrations in the tissues obtained at 22 normal births. Modest elevations in lead concentration were found in the placental body of late fetal deaths (stillbirths) and preterm births as well as in the cord tissue associated with preterm births and premature rupture of membranes. The geometric mean lead concentration in the membranes from late fetal deaths was 2.73 micrograms/g of dry tissue (95% confidence limits 0.69-10.8), which was 3.5 times higher than the mean found in normal births (0.78 micrograms/g, 95% confidence limits 0.61-1.00). The concentration in the membranes of preterm births was also significantly high, being 1.24 micrograms/G (0.91-1.67). Low correlations of membrane and antenatal blood lead concentrations suggest that other factors in addition to exposure to environmental lead may influence the amount of lead accumulated in the placental membranes.

Chemical Industry↗
PubMed1995

Thyroid cytotoxic antibodies in atrophic and goitrous autoimmune thyroiditis.

It is unknown whether in chronic lymphocytic thyroiditis the goitrous (Hashimoto's thyroiditis) and atrophic forms (primary myxedema) are variants of the same disease or different pathogenic entities. Conventional thyroid-related autoimmune parameters are unable to separate both diseases serologically. It is assumed that cellular and humoral cytotoxic events induce gland atrophy and thus should be detectable more often in non-goitrous than goitrous autoimmune thyroiditis. We determined antibody-dependent cell-mediated cytotoxicity in 67 patients with autoimmune thyroiditis, using a 51chromium-release assay against human thyroid cells. Thyroid volume had been measured by ultrasonography. Other thyroid-specific antibodies, like TSH binding-inhibiting antibodies, TSH function-blocking antibodies, thyroglobulin antibodies and thyroid peroxidase antibodies, were determined. Cytotoxic antibody activity was 20.5% (median, range 0-54.5%) in patients with autoimmune thyroiditis and 8.3% (median, range 0-18.4%) in controls (p < 0.0001). Analysis of cytotoxicity regarding thyroid size showed a high incidence of cytotoxic antibodies in atrophic disease (median thyroid volume 6 ml), where cytotoxic antibodies were detectable in 80% versus 39% (x2 = 9.6; p < 0.0001) in goitrous disease (median thyroid volume 36 ml). The specific lysis of 30% (median; 95% confidence limit 23.9-32.9) in non-goitrous thyroiditis patients was significantly higher than in goitrous patients (16.9%; 95% confidence limit 13.2-20.4) (p = 0.0006).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Recurrent unexplained haematuria and risk of urological cancer. A follow-up study.

To evaluate the risk of urological cancer in patients with unexplained haematuria, 93 patients, who had undergone complete urological examination and who were classified as having unexplained haematuria, were followed. Mean age was 46 years, range 16-84 years. Seventy-seven patients had gross haematuria and 16 patients had microscopic haematuria. Mean follow-up time was 62 months (range 6-360 months). Urological neoplasms were found in 7 of 38 patients (18%; 95% confidence limits 8-34%) with recurrent haematuria after primary urological examination, and in 1 of 36 patients (3%; 95% confidence limits 0.07-14%) without additional haematuria after primary examination. Regular urological examination of patients with recurrent unexplained haematuria is justified. In patients without additional incidents of haematuria after primary urological examination the risk of urological cancer is not significantly increased.

Adolescent↗
PubMed1984

Receptor theories and quantitative effect versus dose-concentration relationship.

Both in vivo and in vitro, the dissociation constant K not equal to D50. This was shown for morphine in vivo and for several vasoconstrictors in isolated vascular smooth muscle. When Schild plots are made for a pure competitive antagonist the underlying theory requires that the regression line be constrained to slope -1, for only in this case does pA2 = -log KB, and each has the same confidence limits. Further, even where the slope of the conventional (unconstrained) regression line differs only slightly from -1, the confidence limits of pA2 differ appreciably from those of -log KB. Values of K obtained from pharmacologic methods can discriminate among receptor subtypes. A proper determination of K permits knowledge of the stimulus-response relation, a drug-independent property of the effector system. A perturbation of the drug-receptor equilibrium is a way of determining both k1 and k2; so far, however, we have been successful only with alpha-adrenergic vasoconstrictors in which UV light is a suitable stimulus. Radiolabeled binding appears to be a precise way of determining K's for agonists and antagonists. However, it does not measure an effect; hence we do not know that such binding sites are true receptors unless we can find a correlation between the values obtained for a series of drugs with this method and those obtained with appropriate pharmacologic methods.

Binding, Competitive↗
PubMed1992

Bioequivalence of a new atenolol formulation.

A new generic drug of atenolol, Atenolol (A), (Fahlberg-List Magdeburg, Germany) was studied in comparison with standard preparation (S) in their pharmacokinetic behaviour in 12 patients under steady state conditions. The concentration-time-profile of both preparations was nearly identical. The half time of elimination was calculated for A at 6.5 h and for S at 5.9 h. From the ratio of AUC from A to S (extent of absorption) a mean bioequivalence of 103.1% (90%-confidence limits 0.85-1.21) was estimated. Corresponding values for the rate of absorption were in the mean 102.8% (90%-confidence limits 0.94-1.12).

Adult↗
PubMed1992

[An analysis of the circadian rhythm of the heart rate and arrhythmias in healthy elderly subjects].

The incidence of asymptomatic arrhythmia detected by Holter monitor in the normal aged population is high. Nevertheless, there are few studies in the literature about the existence and characteristics of their circadian rhythm (CR). The aim of this study, is to determine the presence of CR of the heart rate (HR), supraventricular and ventricular extrasystoles (SVE, VE), atrial tachycardias (AT) and ventricular complex tachycardias (VCT) in the normal aged population. We studied 120 subjects, older than 70 years of age, belonging to a pensioner club, without apparent cardiovascular disease by history, physical, ECG, Chest X-Ray and echocardiography. All the patients had a 24 hours Holter monitor. 42 patients whose recording showed more than 50 SVE and/or more than 50 VE were included in the study. To study the CR the cosinor method was used. In the simple analysis, the HR had significant CR in 40 subjects (95.2%), the SVE in 18 out of 29 (62.1%) and the VE in 16 out of 26 (61.5%). The global analysis showed significant CR for the HR, with an acrophase at 15:47 hours (confidence limits at 95% between 14:45 and 15:42 hours) and for the VE, (acrophase: 15:35 hours, confidence limits between 11:53 and 19:05 hours). There was not significant CR for the SVE because the wide dispersion of the acrophases between the subjects. The AT had significant CR but no the VCT. We conclude that the majority of the aged normal subjects with frequent ectopy had significant CR for the HR and extrasystoles. The VE follow a CR similar to the frequency, suggesting a common modulation of the autonomic nervous system. The SVE variation follow a different CR.

Aged↗
PubMed1987

Gallium nitrate in prostatic cancer: evaluation of antitumor activity and effects on bone turnover.

Gallium nitrate, an agent known to inhibit bone resorption, was evaluated in patients with bidimensionally measurable hormone-refractory prostatic cancer. The starting dose was 200 mg/m2 iv by continuous infusion over 7 days. Two patients (10%; 95% confidence limits, 0%-22%) achieved short partial remissions of 1 and 6+ months, while seven of 23 (30%; 95% confidence limits, 14%-52%) showed a diminution of bone pain. Serial indices of bone turnover including serum calcium, phosphorus, and urinary hydroxyproline excretion showed a significant decrease at the completion of the infusion which returned to baseline prior to the next cycle. The data suggest the effect on bone was too short to produce consistent improvement. Reasons for the dissociation of pain relief and antitumor activity are discussed.

Adenocarcinoma↗
PubMed1993

Increased life expectancy of world class male athletes.

Reliable data are scanty on the incidence of chronic diseases and life expectancy (LE) of highly trained athletes. We therefore studied Finnish male world class athletes to estimate the LE of athletes. Finnish team members in the Olympic games, World or European championships or intercountry competitions during 1920-1965 in track and field athletics, cross-country skiing, soccer, ice hockey, basketball, boxing, wrestling, weight lifting, and shooting were included (N = 2613 men). The reference cohort, 1712 men, was selected from the Finnish Defence Forces conscription register matched on age and area of residence. All referents were classified completely healthy at the time of induction to military service. The stratified Kaplan-Meier product limit method and the Cox proportional hazards model were used to estimate the life expectancies and the mortality odds ratios (OR) and their confidence limits. The mean LE adjusted for occupational group, marital status, and the age at entry to the cohort (and its 95% confidence limits) was in endurance sports (long distance running and cross-country skiing) 75.6 (73.6, 77.5) yr; in team games (soccer, ice hockey, basketball, as well as jumpers and short-distance runners from track and field (73.9 (72.7, 75.1) yr; in power sports (boxing, wrestling, weight lifting, and throwers from field athletics) 71.5 (70.4, 72.2) yr; and in the reference group 69.9 (69.0, 70.9) yr. The increased mean life expectancies were mainly explained by decreased cardiovascular mortality (endurance sports mortality odds ratio OR = 0.49 (95% CL 0.26, 0.93), team sports OR = 0.61 (0.41, 0.92) compared with referents). For maximum life span no differences between the groups were observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Cohort Studies↗
PubMed1990

The use of historical data for identifying biologically unimportant but statistically significant results in genotoxicity assays.

The definition of a negative result is a problem in genetic toxicology. Here we suggest that a result may be considered biologically unimportant (negative) if it falls within the limits of variation usually found in the negative controls of the particular test. To determine 'usual' variation, we have set 95% confidence limits on three indices of variation, calculated from historical values for duplicate negative control data from several genotoxicity tests. These tests showed four characteristic types of response and the appropriate index of variability was determined for each. Where there was little test-to-test variation in true mean (micronucleus test and metaphase analysis), confidence limits set on the overall distribution of negative controls were the best index of variability. In other assays (Ames, yeast and mouse lymphoma), there was considerable test-to-test variation so that differences between, or ratios of, the members of control duplicates were the preferred measure of variability. This approach can define what is biologically unimportant in terms of the test system. However, no inference can be drawn as to potential importance. Thus the main use is the removal of the positive 'label' from statistically significant results which fall within the usual range of spontaneous variation for the assay under consideration.

Animals↗