Spontaneous Electron Emission from Hot Silver Dimer Anions: Breakdown of the Born-Oppenheimer Approximation

We report the first experimental evidence of spontaneous electron emission from a homonuclear dimer anion through direct measurements of Ag_{2}^{-}→Ag_{2}+e^{-} decays on milliseconds and seconds timescales. This observation is very surprising as there is no avoided crossing between adiabatic energy curves to mediate such a process. The process is weak, yet dominates the decay signal after 100 ms when ensembles of internally hot Ag_{2}^{-} ions are stored in the cryogenic ion-beam storage ring, DESIREE, for 10 s. The electron emission process is associated with an instantaneous, very large reduction of the vibrational energy of the dimer system. This represents a dramatic deviation from a Born-Oppenheimer description of dimer dynamics.

Erratum: Rotationally Cold OH^{-} Ions in the Cryogenic Electrostatic Ion-Beam Storage Ring DESIREE [Phys. Rev. Lett. 119, 073001 (2017)]

This corrects the article DOI: 10.1103/PhysRevLett.119.073001.

Dianion diagnostics in DESIREE: High-sensitivity detection of Cn2- from a sputter ion source

A sputter ion source with a solid graphite target has been used to produce dianions with a focus on carbon cluster dianions, C_n^2-, with n = 7-24. Singly and doubly charged anions from the source were accelerated together to kinetic energies of 10 keV per atomic unit of charge and injected into one of the cryogenic (13 K) ion-beam storage rings of the Double ElectroStatic Ion Ring Experiment facility at Stockholm University. Spontaneous decay of internally hot C_n^2- dianions injected into the ring yielded C_n^- anions with kinetic energies of 20 keV, which were counted with a microchannel plate detector. Mass spectra produced by scanning the magnetic field of a 90° analyzing magnet on the ion injection line reflect the production of internally hot C₇^2- - C₂₄^2- dianions with lifetimes in the range of tens of microseconds to milliseconds. In spite of the high sensitivity of this method, no conclusive evidence of C₆^2- was found while there was a clear C₇^2- signal with the expected isotopic distribution. This is consistent with earlier experimental studies and with theoretical predictions. An upper limit is deduced for a C₆^2- signal that is two orders-of-magnitude smaller than that for C₇^2-. In addition, C_nO^2- and C_nCu^2- dianions were detected.

Rotationally Cold OH^{-} Ions in the Cryogenic Electrostatic Ion-Beam Storage Ring DESIREE

We apply near-threshold laser photodetachment to characterize the rotational quantum level distribution of OH^{-} ions stored in the cryogenic ion-beam storage ring DESIREE at Stockholm University. We find that the stored ions relax to a rotational temperature of 13.4±0.2  K with 94.9±0.3% of the ions in the rotational ground state. This is consistent with the storage ring temperature of 13.5±0.5  K as measured with eight silicon diodes but in contrast to all earlier studies in cryogenic traps and rings where the rotational temperatures were always much higher than those of the storage devices at their lowest temperatures. Furthermore, we actively modify the rotational distribution through selective photodetachment to produce an OH^{-} beam where 99.1±0.1% of approximately one million stored ions are in the J=0 rotational ground state. We measure the intrinsic lifetime of the J=1 rotational level to be 145±28  s.

The relationship between marginal bone loss and serum zinc levels

Serum was analyzed for zinc in 51 patients of varying age and with varying degrees of alveolar bone loss as recorded on roentgenograms. There was a reversed correlation between marginal alveolar bone loss and serum zinc levels. The observations are discussed in relation to the physiological functions of zinc.

Correlation between prognostic factors and blood variables in osteosarcoma

Prognostic factors and the blood chemistry were analyzed prior to treatment in 33 consecutive patients with primary osteosarcoma. The only variables of blood chemistry with values outside the normal range were alkaline phosphatase and ESR, which were increased. There was a correlation between certain prognostic factors and between some of these and a number of the blood variables. The degree of malignancy tended to be lower in the female than in the male patients. Distally located tumors tended to be smaller and were assessed with a less marked effect on the blood variables than those located proximally.

Direct quantification in bioanalytical LC–MS/MS using internal calibration via analyte/stable isotope ratio

The possibility to rationalize and simplify bioanalysis, without compromising the analytical quality, by omitting the calibration curves was studied. Using mass spectrometry (MS) and a stable isotope labeled internal standard it was possible to get equally good results by calculating the results directly from the analyte/internal standard area ratio and a predetermined response factor as by the traditional way, using a calibration curve run at the same occasion. To be able to use this simplified quantification method, that we call internal calibration, in its most simple form there are some prerequisites that must be considered: (1) The relative response should not be concentration dependent. (2) The relative response should be constant between batches/days. (3) The level of analyte in the internal standard should not be detectable. (4) There should be no influence from naturally occurring isotopes of the analyte on the internal standard peak area. A bioanalytical LC-MS/MS method for a research compound was validated both with and without calibration curves and no significant differences were found regarding precision and accuracy. It was shown that all four prerequisites above were fulfilled. Validation data were very good for the whole concentration range, 0.010-30 micromol/L. Long-term data for QC samples showed excellent precision and accuracy.

A novel approach to data processing of the QT interval response in the conscious telemetered beagle dog

INTRODUCTION

Drug-induced QT interval prolongation may lead to ventricular arrhythmias. The aim of the study was to optimize QT interval data processing to quantify drug-induced QT interval prolongation in the telemetry instrumented conscious dog model.

METHODS

The test substances cisapride, dofetilide, haloperidol, and terfenadine and corresponding vehicles were given to male and female beagle dogs during two consecutive 90-min intravenous infusions. Cardiovascular parameters were recorded for 24 h and exposure to the drugs was measured. The delayed response in the QT interval after an abrupt change in heart rate was investigated. Eight mathematical models to describe the QT interval-heart rate relationship were compared and different sets of covariates were used to quantify the drug-induced effect on the QT interval.

RESULTS

After an abrupt decrease in heart rate, a 75% adaptation of the QT interval was reached after 54+/-9 s. A linear model was preferred to correct the drug-induced effect on the QT interval for heart rate, vehicle effect, serial correlation, plasma concentration and time of day. All test substances significantly prolonged the QT interval.

DISCUSSION

To optimize the processing of QT interval data, the delay in QT interval response after an abrupt change in heart rate should be considered. The QT interval-heart rate relationship and vehicle response were individual-specific and corrections were therefore made individually. When estimating the drug-induced effect on the QT interval it is considered advantageous to use plasma concentration as a covariate, as well as adjusting for vehicle effect and serial correlation in measurements. The conscious dog model detected significant increases in the QT interval for all test substances investigated.

Pharmacokinetic-pharmacodynamic modeling of drug-induced effect on the QT interval in conscious telemetered dogs

INTRODUCTION

To assure drug safety, the investigation of the relationship between plasma concentration and drug-induced prolongation of the QT interval of the ECG is a challenge in drug discovery. For this purpose, dofetilide was utilized to demonstrate the benefits of characterizing the complete time course of concentrations and effect in conscious beagle dogs in the assessment of drug safety.

METHOD

On two separate occasions, four male and two female beagle dogs were given vehicle or the test substance, dofetilide (0.25 mumol/kg), over a 3-h intravenous infusion. Cardiovascular parameters, including QT intervals, were recorded for 24-h using radiotelemetry. The QT interval was corrected individually for heart rate, vehicle treatment, and serial correlation (QT(c)). Exposure (plasma concentration) to dofetilide was measured and described by a two-compartment model. The individual concentration-time course of dofetilide was linked to the QT(c) interval via an effect compartment and a pharmacodynamic E(max) model, to account for the observed hysteresis.

RESULTS

Dofetilide induced a concentration-dependent increase in the QT(c) interval, with an EC(50) of 9 nM (3-30 nM, 95% C.I.) and an E(max) of 59+/-9 ms. A hysteresis loop was observed by plotting plasma concentrations vs. QT interval in time order, indicating a delay in onset of effect. It was found to have an equilibrium half-life of 11+/-8 min. Based on the parameters potency and E(max), a representation was made of the drug-induced changes to the QT interval.

DISCUSSION

An effect compartment model was found to accurately mimic the QT interval prolongation following administration of the test substance, dofetilide. The assessment of the individual concentration-effect relationship and confounding factors such as hysteresis might provide a better prediction of the safety profiles of new drug candidates.

Prenatal nicotine exposure and pulmonary barotrauma of newborns

Smoking in adults increases the relative risk of contracting spontaneous pneumothorax, a form of pulmonary barotrauma. Maternal smoking habits affect the fetus. Pregnant females attend the antenatal clinic at the 8th to 12th weeks of pregnancy. There is a participation rate of 99% of all births in Sweden. Their smoking habits were registered at this stage. This study supported the hypothesis that the registered maternal smoking habits covariated with the risk of contracting pulmonary barotrauma in newborn infants. The infants of smokers do not seem to be at higher risk (95% C.I. of RR: 0.78-0.99) for contracting pulmonary barotrauma than those of nonsmokers. Thus far, the hypothesis is even rejected at the 5% significance level. However, after considering other factors, especially mother's education, it seems to be an open question whether or not a weak covariation is present. Newborn boys run almost twice the risk of contracting pulmonary barotrauma than girls. Furthermore, we found an increased risk for contracting pulmonary barotrauma in the subcohort of newborns whose mothers' smoking habits were not reported.

Analysis of hereditary component of cancer by use of a familial index by site

To quantify hereditary factors in the risk of cancer, we matched 1283047 cancer patients listed in the Swedish Cancer Registry with healthy controls from a national database, and identified the number of individuals who were first-degree relatives of other individuals in the same cohort. Division of the number of relatives in the patient cohort by the number in the control cohort yielded a "familial index". The following cancers had high familial indices: eye 16.5 (95% CI 2.5-666), testis 9.0 (3.2-35), Hodgkin's disease 6.5 (2.3-26.0), and thyroid 6.2 (3.7-12). Overall, however, familial factors made only a minor contribution to susceptibility to cancer.

Bioavailability of cadmium from infant diets in newborn rats

Infants are exposed to higher levels of cadmium (Cd) from infant and follow-on formulas than from breast milk. We studied the bioavailability of 109CdCl2 from cows' milk formula, soy formula, wheat/oat/milk formula, wholemeal/milk formula and water in 11-day-old rat pups. The pups received a single oral dose of one diet labelled with 109Cd, 0.1 or 0.3 mg Cd/kg body weight. After 2 or 24 h or 4, 9 or 12 days the fractional retention of 109Cd in the whole body, in segments of rinsed small intestine and in tissue was measured in a gamma counter. Pups receiving 109Cd in water or cows' milk formula had the highest mean whole-body retention. It ranged from 67% of the dose in the water group to 52% in the wholemeal/milk formula group 4 days after dosing. The retention of 109Cd in the rinsed small intestine was significantly higher in the water group and the cows' milk formula group than in the cereal-based formula groups at 24 h and 4 days after dosing. It was still high in all groups on day 9, ranging from 26 to 11%. Initially most of the 109Cd was retained in the duodenum but by day 4 it had moved further down into the jejunum. In the liver, the highest and lowest retention on day 4 was 16%, and 3 per thousand of the dose in the water group and wholemeal/milk formula group, respectively. In the kidney, 109Cd was still increasing 12 days after exposure in all groups. Whole-body retention and tissue levels were higher than previously reported in adult animals. The lower bioavailability of 109Cd from the cereal-based formulas compared to water and cows milk formula on the longer survival times is most likely explained by Cd binding to dietary fibre and phytic acid in the cereal-based formulas reducing the intestinal binding and decreasing the bioavailability of Cd. The high retention of 109Cd in the small intestine, leading to a prolonged absorption period, emphasizes the importance of extending studies on neonatal Cd absorption over a long time period in order to detect for example, endpoints, accumulation of Cd in the kidney.

Exposure of cadmium from infant formulas and weaning foods

Cadmium levels were determined in 59 baby food samples, including milk-based, cereal and milk-based and soy-based formulas, recommended from 0 to 18 months of age. Determinations were performed by Zeeman graphite furnace atomic absorption spectrophotometry, after dry ashing, with parallel determinations of certified reference samples. Mean cadmium levels were found to range from 1.10 to 23.5 micrograms/kg fresh weight concentrated formulas. Levels were related to the composition of the diets. Formulas based on cow's milk had the lowest concentrations. Soy formulas contained approximately six times more cadmium than cow's milk formulas, and diets with a cereal content had 4-21 times higher mean levels. The mean weekly intakes of dietary cadmium were estimated to vary between 0.10 and 3.05 micrograms/kg body weight of the child, if the recommended amount of formula were to be consumed at the recommended age, and if the child were of average weight. This estimation however does not include the contribution of cadmium from drinking water. The highest intake on a body weight basis was found in 6-month-old children, consuming the recommended amount of wheat-, oat- and milk-based formulas. This intake is below the provisional tolerable weekly intake (PTWI) of 7 micrograms/kg body weight, established by a WHO/FAO expert group. However, the risk assessment is based on renal effects in adults. Furthermore, preparations of a formula by adding water with cadmium concentrations at the WHO guideline level could lead to intakes at the PTWI level. Compared to breast-fed children, the exposure of dietary cadmium from weaning diets can be up to 12 times higher in children fed infant formula.

Age-specific suicide rates in the Slavic and Baltic regions of the former USSR during perestroika, in comparison with 22 European countries

Age-specific differences in suicide rates in the Baltic and Slavic regions of the former USSR were studied for the period 1984-1990, and were compared to those of 22 European countries. It was observed that suicide rates per 100,000 inhabitants in the Slavic and Baltic regions increased directly with age for women, and showed a bimodal distribution with peaks for the 45-54 and > or = 75 age groups for men. In most of the 22 European countries, the suicide rates of both men and women increased directly with age. In 1990 the suicide rates in the Slavic and Baltic regions ranged from 25.1 for the 15-24 age group to 86.9 for men aged 75 or older, and from 6.0 to 29.8 for women, while the suicide rates in Europe ranged from 13.0 to 64.8 for men and from 3.6 to 18.7 for women. Decreases in the suicide rates in the Slavic and Baltic regions during perestroika were largest for the 25-54 age group, averaging at drop of 45% for men and 33% for women between 1984 and 1986-1988. The pattern of age-specific suicide rates for women in the Slavic and Baltic regions remained similar to that in Europe throughout the period studied. This was in contrast to a distinct pattern of male suicide rates in the Slavic and Baltic regions in 1984, which converged with those found in other parts of Europe during 1986-1988. It appears that perestroika contributed to a unique pattern of male suicide mortality in the Slavic and Baltic regions, especially in the 25-54 age group.

Marked decrease in suicide among men and women in the former USSR during perestroika

At the same time as substantial and rapid socio-political and socio-economic changes took place during the period of perestroika, suicide rates in the former USSR decreased by approximately 32% for men and 19% for women. The decreases in the suicide rates of men in the former USSR were unlike the suicide rate decreases taking place in 22 other European countries, where rates decreased by approximately 8% for men and 17% for women during this time period. Declines in suicide rates from 1984 to 1986-1988 occurred in all republics, with the largest decreases in Russia and Belarus, at 42% for men and 20% for women. The decrease in suicide rates of men in the former USSR was most pronounced until 1986-1988, after which time an increasing trend was observed. Suicide rates for men in the former USSR decreased 3.8-fold more than they did for men in other parts of Europe, while decreases in the suicide rates for women in the former USSR were on the same level as in Europe.

The decline of smoking among Swedish men

BACKGROUND

In 1987 the Association of the Nordic Cancer Registers (ANCR) predicted the incidence of lung cancer in the Nordic countries up to the years 2000 and 2010. The predictions for Sweden can now be considered against recent information on smoking habits.

METHODS

Regular, question-based studies on the public's tobacco consumption are carried out by four separate institutions in Sweden. This article summarizes and updates the smoking habits among Swedish men in the age groups 35-54 and 55-70 years between 1963 and 1994, with special focus on smoking cessation.

RESULTS

Between 1963 and 1994, there was a significant and continuous decrease in the prevalence of smoking among Swedish men. During this time ex-smoking men increased from 20% to 41%. The data reveal a continuous, unbroken and uniform increase in smoking cessation rates during the last 20 years, despite the small success of smoking cessation programmes and smoking-relapse rates of 75-80%. The explanation of this seems to be the surprisingly high frequency of smokers who attempted to stop smoking each year (about 30%). The best success rate in smoking cessation was achieved by occasional smokers and others with a low cigarette consumption.

CONCLUSION

With the continuing fall in the numbers of smoking men, a greater drop in lung cancer incidence than predicted by the ANCR in 1987 may be expected in Sweden within the coming decade.

Female suicides and alcohol consumption during perestroika in the former USSR

During 1984-1990, a decline in suicide rates of 32% for males and 19% for females took place in the former Soviet Union. The observed annual decrease in mortality from suicide was most marked for men in 1984-1986 and for women in 1984-1988. This article illuminates the hypothesis that the restrictive anti-alcohol campaign initiated by Gorbachev on 1 June 1985, in which prices of alcoholic beverages were raised substantially, had an impact on female mortality from suicide in the former Soviet Union. Data regarding alcohol consumption, female violent death (n = 451,537), suicide (n = 94,149), death due to accidental alcohol poisoning (n = 28,078), and undetermined death, whether accidental or self-inflicted (n = 23,982) were analysed for three Slavic (Russia, Belarus and the Ukraine), three Baltic (Lithuania, Latvia and Estonia) and two Central Asian republics (Kazakhstan and Kirgizia). Regression analyses with alcohol consumption as the independent variable and female suicide rates and female violent-death rates as dependent variables showed that suicide and alcohol consumption, as well as violent death and alcohol consumption, were positively correlated. However, alcohol seems to have a lower explanatory value for female suicides and female violent deaths compared with male suicides and male violent deaths. The attributable fraction of alcohol for female suicides in the whole USSR (27%) is estimated at approximately half of that for male suicides (50%).

Living conditions of female suicide attempters: a case-control study

A total of 51 hospitalized female suicide attempters (17-64 years old) were interviewed according to a questionnaire used by Statistics Sweden, SCB (ULF 88:1) for investigation of living conditions. Control subjects from similar geographical areas included in the ULF investigation in 1988, and matched for age and nationality, were identified through the SCB (n = 153). Odds ratios (OR) and 95% confidence limits were estimated. Correlation coefficients were used to study the relative importance of specific factors. Not less than 26 items reached the level of statistical significance, but only four of them (mental disorder, use of anxiolytics, unemployment at some time during the last 5 years, and no professional work during the past year) showed a considerable excess risk (lower 95% CI limit for OR > 3). Physical illness was relevant as an independent factor. Although of secondary importance, hospitalization during the previous 3 months was also a characteristic of suicide attempters.

Notable relationship between the level of tumor marker TPS in serum and survival in breast cancer

Tissue Polypeptide Specific antigen (TPS) in serum was measured once during the follow-up of 200 breast cancer patients and compared with survival. Within 12 months, patients with normal TPS (< 80 U/L) exhibited a 3% death rate (3/96), which was undistinguishable from the mortality of normal females of corresponding age. Patients with moderate TPS (80-400 U/L) suffered 19% death (14/72), and patients with high TPS (> 400 U/L) 72% death (23/32). The relative risk (RR) of death within 6 months was 1 with normal TPS, 8 with moderate TPS, and 48 with high TPS. RR for 12 months was 1, 6, and 23, respectively. Serum TPS at admission had a significant predictive value with regard to survival up to 12 months.

A decline in the lung cancer incidence amongst men in Swedish cities

A statistically-significant (p < 0.01) decrease in the incidence of lung cancer has been observed amongst men in larger Swedish cities, but not in the country as a whole. The decrease is foremostly attributable to changes within the group of older men (i.e., > 65 years). The investigation is based on the Swedish Cancer Registry and covers the period 1975-1989.

Suicides in the Baltic countries, 1968-90

Trends of male and female suicides in the Baltic countries--Estonia, Latvia and Lithuania--in the years 1968-90 were studied. As throughout the former USSR, suicide rates declined sharply from 1986, the year marking the onset of turbulent social change. During the "period of stagnation" from 1968 to 1984, the mean value of male suicide rates per 100,000 males were 55.7 in Estonia, 52.5 in Latvia and 51.7 in Lithuania. The figures for female suicide rates were 14.3, 14.3 and 10.4, respectively. Suicide rates remained consistently high in Estonia and Latvia, while in Lithuania the male suicide rate rose gradually from 33.0 to 61.3 and the female rate from 8.0 to 13.1 during the stagnation period. In conjunction with perestroika in the former USSR (including a restrictive alcohol policy and the first tentative steps towards democracy), annual male suicide rates per 100,000 in the years 1986-90 fell considerably below those in the stagnation period. Mean values of male suicide rates decreased by 26.6% in Estonia, 26.6% in Latvia and 14.4% in Lithuania in the period 1986-90 compared with the mean values for the period 1968-84. Female suicide rates were relatively stable and the male-female ratio was accordingly lower in 1986-90 (Estonia and Latvia 3.1, Lithuania 4.2) than in 1968-84 (Estonia 3.9, Latvia 3.7 and Lithuania 5.0).

Male suicides and alcohol consumption in the former USSR

A significant decline (34.5%) in the suicide rate occurred in 1984-1988 throughout the USSR. The decline was observed shortly after the introduction of strict restrictions on the sale of alcohol. We tested the hypothesis that the restrictive alcohol policy in the first years of perestroika (June 1985) caused the fall in suicide rates in the former USSR. Data on alcohol consumption, violent death caused by external injury and poisoning (n = 916,315), death due to accidental alcohol poisoning (n = 77,837), suicide (n = 192,305) and death undetermined whether accidentally or purposely (n = 54,253) were analyzed for all former Soviet republics for 1984, 1986, 1988 and 1990. Men were chosen for the analysis, since men are more prone to abuse alcohol than women. Regression analysis with alcohol consumption as the independent variable and suicide rates and violent death rates as dependent variables shows that suicide and alcohol consumption were positively correlated as were violet death and alcohol consumption. In the republics with high alcohol consumption (Slavic and Baltic), suicide rates were also high. In the Caucasian republics, low alcohol consumption was associated with low suicide rates. For most republics, alcohol seems to explain more than 50% of suicides. Alcohol also has considerable explanatory value for violent death. Thus, a restrictive alcohol policy might be a way to reduce suicide and violent death.

Epstein-Barr virus infection, salted fish and nasopharyngeal carcinoma. A case-control study in southern China

Two hundred and five histologically confirmed cases of nasopharyngeal carcinoma (NPC) in southern China, and an equal number of matched controls, were investigated for their dietary habits, occupational exposure, use of tobacco and alcohol, history of relatives with NPC, and IgA against Epstein-Barr virus (EBV) capsid antigen (IgA/VCA). Positive IgA/VCA and intake of salted fish were associated with a strong excess risk of NPC. The association persisted after adjustment for other factors. The combination of salted fish and EBV was strongly associated with NPC, and more so than EBV or salted fish per se. Multivariate analyses showed that IgA/VCA was the most important predictor of NPC, and salted fish the second most important. These results suggest that EBV has a strong effect on the development of NPC. The exclusion of EBV and genetic factors in earlier epidemiological studies may have resulted in an overestimation of salted fish as important etiological factor causing NPC.

Nonsmoking, non-alpha 1-antitrypsin deficiency-induced emphysema in nonsmokers with healed spontaneous pneumothorax, identified by computed tomography of the lungs

This case-control study is based on an investigation of 27 nonsmoking patients with radiologically verified spontaneous pneumothorax (SP) and ten healthy never-smoker control subjects. The posteroanterior and lateral radiographs of patients and control subjects were normal. They were all submitted to the same clinical, laboratory, and radiologic examinations, including computed tomography (CT) of the lungs, with the aim of detecting any parenchymatous lung changes. Emphysema-like changes (ELCs) were detected on CT in 22 (81 percent) of the 27 patients, and if the ELC cases detected during interventional surgery are added, the frequency increases to 24/27 (89 percent). In 20 patients with unilateral SP, at least one ELC was found in 13 of the 20 SP-affected lungs, but only in five of the 20 lungs that were not diagnosed as having SP (p < 0.05). ELCs were found more frequently in the upper than in the lower lung regions (p < 0.05) and more frequently in the radiologically peripheral than in central regions (p < 0.001). No ELC was detected in the control group on CT. No alpha 1-antitrypsin deficiency was found in the 27 nonsmoking patients with radiologically verified SP who had ELCs despite the absence of these known promoters of emphysema.

Obstetric medication versus residential area as perinatal risk factors for subsequent adult drug addiction in offspring

In an attempt to explain pronounced uneven distributions of births of subsequent amphetamine and opiate addicts at seven hospitals in Stockholm, two possible mechanisms for adult drug addiction were weighed against each other: (1) risk factors associated with the obstetric care at the hospitals of birth of the addicts and (2) risk factors associated with the phenomenon of 'contagious' transmission of drug addiction in certain residential areas during adolescence. The subjects comprised 200 amphetamine addicts and 200 opiate addicts born between 1945 and 1966. By loglinear analysis the relative risk for future addiction was determined for eight residential areas as well as for the seven hospitals and four periods of birth. For the opiate addicts only one weak association was found for the residential area, which could not explain fully a clustering of births at any particular hospital. For the amphetamine addicts, hospital of birth was found to be an important risk factor even after controlling for residential area. Hence, the variable residential area has not been able to explain the uneven distribution of births of drug abusers among the studied hospitals.

Socio-economic versus obstetric risk factors for drug addiction in offspring

Two possible risk factors for drug addiction were weighed against each other: (1) perinatal factors associated with obstetric medication at time of birth; and (2) factors associated with familial socio-economic conditions at time of birth. The subjects comprised 200 amphetamine addicts and 200 opiate addicts born in Stockholm 1945-1966. In a matched case control study, addicts were compared to their siblings with regard to possible obstetric risk factors by means of conditional logistic regression controlling for socio-economic level and civil status. Administration of opiates, barbiturates and nitrous oxide to mothers during labour was associated with drug addiction in offspring, hence confirming results from earlier studies. In a cohort study the risk associated with birth at a given hospital and familial socio-economic level was analysed by means of log-linear analysis using 7100 controls from the general population. For amphetamine addicts, a low socio-economic level at time of birth might be of importance for the infant subsequently becoming an addict. This could not be demonstrated for the opiate addicts. An uneven distribution of births among the hospitals, most pronounced for the amphetamine addicts, is in agreement with the hypothesis that obstetric practices may be risk factors for adult drug addiction.

Bilateral bronchial anomaly. A pathogenetic factor in spontaneous pneumothorax

Flexible fiberoptic bronchoscopy (FFB) was performed in 26 never-smokers with healed spontaneous pneumothorax (SP) with the aim of detecting and localizing any bronchial obstruction, including congenital anomaly. In a case-control study these patients were compared with a consecutive, randomly sampled, control group of 41 patients who were undergoing FFB for respiratory symptoms but who had not had a SP. In both groups the endobronchial anatomy with respect to such anomalies, which could be classified as disproportionate bronchial anatomy, an accessory bronchus, and/or a missing bronchus, was compared with normal anatomy. All except one of the 26 patients with SP but only four of the 41 control patients without SP had such bronchial anomalies bilaterally. This corresponds to an odds ratio of 231 (95% confidence interval, 24 to 880; p < 0.001). The significantly higher frequency of bilateral bronchial anomalies in never-smokers with SP suggests that a virtual prerequisite for the occurrence of SP has been found. However causal links between the probably congenital bronchial anomalies and SP have not yet been identified.

Response bias in a case-control study: analysis utilizing comparative data concerning legal abortions from two independent Swedish studies

Independent reports of legal abortions in two Swedish epidemiologic studies of breast cancer in young women, covering the same women and overlapping the same time period, have been compared in order to estimate a putative response bias. One study used case-control methods and obtained data by retrospective interviews from 317 cases and 512 controls. The other study was based on objectively documented information froma nationwide registry covering legally induced abortions. Analysis demonstrated a ratio between the odds ratios from the two studies of 1.5 (95 percent confidence interval 1.1-2.1) and an observed ratio of 22.4 (p less than 0.007) between underreporting of previous induced abortions among controls relative to overreporting among cases. This response bias may explain the tendency toward increased risk of breast cancer which, according to several case-control studies, appears to be associated with induced abortion.

Condylomata acuminata and risk of cancer: an epidemiological study

OBJECTIVE

To determine whether patients with condylomata acuminata have an increased risk of developing cancer.

DESIGN

Prospective cohort study on patients diagnosed as having condylomata acuminata. The number of malignant tumours in the cohort was compared with national incidences obtained from the Swedish Cancer Registry.

SETTING

Dermatology department of the Karolinska Hospital, Stockholm, Sweden.

SUBJECTS

3260 patients (2549 males and 711 females, median (range) age 23 (1-80) years) seen during 1969-84, with a mean follow up of 7.8 years.

MAIN OUTCOME MEASURES

Number of malignant tumours observed in the cohort during the study period and expected number from national incidence.

RESULTS

There were 27 malignancies in the study group. There was no significant increase genital cancer in females compared with the national incidence. Only one patient had invasive cervical cancer (relative risk = 1.8; 95% confidence interval 0 to 10.1). Seventeen women had cervical carcinoma in situ (1.5; 0.9 to 2.5) compared with an expected number of 11.5; this increase was not significant. For males 22 cancers were observed at all sites (1.6; 1.0 to 2.5). The number of genitourinary cancers observed in males was almost three times higher than expected (2.6; 1.2 to 5.0).

CONCLUSION

The results indicate that the risk of developing cervical carcinoma in situ or invasive cervical cancer after a genital human papillomavirus infection is less than previously thought. The implications of increase in the genitourinary malignancies in males are uncertain.

Acute leukemia in professional drivers exposed to gasoline and diesel

The environmental exposure to the petroleum products gasoline, diesel, and their motor exhausts was studied in a case-control interview of 125 patients with acute leukemia and 1 matched control per patient. Odds ratios were calculated by comparing discordant matched patient-control pairs. An excess risk for developing acute leukemia was found for the professional drivers, and odds ratio was determined to be 3.0 (95% CI: 1.1-9.2/p less than or equal to 0.02). For those who were exposed for more than 5 years in their life-time, or more than 1 yr during the 5-20 yr period prior to diagnosis, the odds ratio was 5.0 (p less than 0.05). This finding remains after consideration is given to exposures to organic solvents, smoking and therapeutic x-ray treatment. No excess risk was observed for persons professionally exposed to motor oil and machine oil without exposure to fuels and exhausts. No preferential type of acute leukemia was found to be associated with exposure to fuels and their exhausts. The results indicate an etiological relationship between the development of acute leukemia and exposure to petroleum products as fuels and exhaust.

Occurrence of other malignancies in 1973 patients with basal cell carcinoma

To evaluate the possible association of other malignancies with basal cell carcinoma, we reviewed 1973 consecutive patients with basal cell carcinoma. We searched the Swedish Cancer Registry for records reporting malignancies in the study population (1958-1984) and the expected number of malignancies was calculated on the basis of age- and sex-standardized incidence data. In 452 patients with basal cell carcinoma another malignancy was diagnosed. The expected number was 323 (relative risk = 1.4; 95% confidence interval = 1.3 to 1.5). A significant association with basal cell carcinoma was found in four cancer types for men and in three for women. For skin malignancies other than malignant melanoma there was more than a sixfold increased risk for men (relative risk = 6.8; 95% confidence interval = 4.8 to 9.4) and more than a threefold increased risk for women (relative risk = 3.1; 95% confidence interval = 1.4 to 5.9) during the period after the diagnosis of basal cell carcinoma. During the period before the diagnosis of basal cell carcinoma, there were also increased risks (men: relative risk = 5.0; 95% confidence interval = 3.1 to 7.5; women: relative risk = 4.0; 95% confidence interval = 1.9 to 7.4). This was in contrast to the risks of malignant melanoma. Before the diagnosis of basal cell carcinoma there was no significant increased risk of malignant melanoma but after the diagnosis there was more than a sixfold increased risk for men (relative risk = 6.8; 95% confidence interval = 4.8 to 9.4) and more than a fourfold increased risk for women (relative risk = 4.2; 95% confidence interval = 1.5 to 9.2).(ABSTRACT TRUNCATED AT 250 WORDS)

Randomized study of mammography screening--preliminary report on mortality in the Stockholm trial

In March 1981, 40,318 women in Stockholm, aged 40-64, entered a randomized trial of breast cancer screening by single-view mammography alone versus no intervention in a control group of 20,000 women. The attendance rate during the first screening round was 81 per cent and the cancer detection rate was 4.0 per 1000 women. The detection the rate fell to 3.1 per 1000 in the second round, which was completed in October 1985. During 1986 the controlled design of the study was broken and the control women were invited once to screening which was completed the same year. A total of 428 cases of breast cancer were thus diagnosed in the study group and 439 in the adjusted control group. After a mean follow-up of 7.4 years the number of breast cancer deaths in the study and control groups was 39 and 30 respectively. The relative risk of breast cancer death (screening versus control) was 0.71 (95 per cent confidence interval: 0.4-1.2). Among women older than 50 years at entry the relative risk was 0.57 (95 percent confidence interval: 0.3-1.1). Cancer deaths among women under 50 were few and perhaps because of this no mortality reduction was seen in this age group. The estimate of mortality reduction lies between the results from two earlier Swedish randomized controlled trials.

Mortality among Swedish reindeer breeding Lapps in 1961-85

We analyzed the mortality pattern among Swedish reindeer breeding Lapps, a unique group with a carefully preserved culture and a lifestyle that differs considerably from that of the rest of the population. The cohort consisted of 2,034 Lapps who were recorded in the 1960 Population and Housing census as members of a household where someone were occupied in reindeer breeding. The cohort was followed-up in the Swedish Cause-of-Death Register from January 1, 1961 until death or December 31, 1985. The total mortality was similar to that of the entire population. Four hundred and twenty eight deaths occurred and the standardized mortality ratio (SMR) was 0.95. Ischemic heart disease was the most frequent cause-of-death and the mortality was the same as in the general population (SMR = 0.95). Significantly lower mortality than expected was observed for malignant tumors (SMR = 0.70), diseases of the circulatory system (SMR = 0.68 and for diseases of the digestive system (SMR = 0.42). Significantly increased SMR was found for external causes of injury (SMR = 1.83) and among female Lapps for cerebrovascular diseases (SMR = 1.70). Female Lapps had a significantly higher mortality of diseases of the circulatory system (SMR = 1.19) in relation to males (SMR = 0.48).

Cancer risks in Swedish Lapps who breed reindeer

Cancer risks during the period 1961-1984 were studied in a cohort of 2,034 Swedish reindeer-breeding Lapps, a unique group whose culture and life-style differ considerably from those in the rest of the Swedish population. A total of 100 cases of cancer were observed versus 163 expected. Statistically significantly decreased risks were found for cancers of the colon, respiratory organs, female breast, male genital organs, and kidneys, and for malignant lymphomas. The stomach was the only site with a significantly increased risk. Reindeer-breeding Lapps have ingested fallout products via the lichen-reindeer-man food chain since the 1950s. However, no increased risk was found for the cancer sites considered to be most sensitive to radiation.

Opiate addiction in adult offspring through possible imprinting after obstetric treatment

OBJECTIVE

To test the hypothesis that opiate addiction in adults might stem partly from an imprinting process during birth when certain drugs are given to the mother.

DESIGN

Retrospective study by logistic regression of opiate addicts with siblings as controls.

SETTING

Stockholm, Sweden.

SUBJECTS

200 Opiate addicts born in Stockholm during 1945-66, comprising 41 identified during interviews of probands for an earlier study; 75 patients whose death from opiate addiction had been confirmed during 1978-88; and 84 accepted for the methadone programme. 262 Siblings (controls) born in Stockholm during the same period, 24 of whom were excluded for drug addiction or being brought up outside the family. Birth records were unavailable for eight, leaving 230 siblings and 139 corresponding probands.

MAIN OUTCOME MEASURES

Administration of opiates, barbiturates, and nitrous oxide (for greater than 1 h) to mothers of all subjects during labour within 10 hours before birth as a risk factor for adult opiate addiction.

RESULTS

In subjects who had subsequently become addicts a significant proportion of mothers had received opiates or barbiturates, or both, compared with unmatched siblings (25% v 16%, chi 2 = 5.83, df = 1, p = 0.02), and these mothers had received nitrous oxide for longer and more often. After controlling for hospital of birth, order of birth, duration of labour, presentation other than vertex, surgical intervention, asphyxia, meconium stained amniotic fluid, and birth weight the relative risk for offspring subsequently becoming an adult opiate addict increased with the number of administrations of any of the three drugs. When the addicts were matched with their own siblings the estimated relative risk was 4.7 (95% confidence interval 1.8 to 12.4, p for trend = 0.002) for three administrations compared with when no drug was given.

CONCLUSIONS

The results are compatible with the imprinting hypothesis. Therefore, for obstetric pain relief methods are preferable that do not permit substantial passage of drugs through the placenta.

Chronic urticaria and cancer: an epidemiological study of 1155 patients

To evaluate the possible association of malignant disease with chronic urticaria 1155 consecutive cases with chronic urticaria were reviewed. The Swedish Cancer Registry, Stockholm, was searched for records reporting malignancies in the study population (1958-84), and the expected number of malignancies was calculated on the basis of age- and sex-standardized incidence data. A malignancy was diagnosed in 36 patients with urticaria and the expected number of malignancies was 41. In 23 patients the malignancy appeared during the same year as the onset of urticaria or later. The expected number was 25.6. We conclude that chronic urticaria is not statistically associated with malignancy in general.

The prevalence of malignant tumors in patients with psoriasis

A possible association between psoriasis and cancer was investigated by linking the Swedish Psoriasis Association's membership registry to the Swedish Cancer Registry. The population studied was 20,328 living persons. Since 1958 a cancer was recorded in 520 of them. The expected number, based on the prevalence of cancer in Sweden, was 540. Among 43 cancer sites for men and 46 for women selected primarily for analysis, a significant association with psoriasis was found only in two types of cancer. For male breast cancer the observed number was 4 and the expected number was 0.58, and for female kidney cancers the observed number was 17 and the expected number was 6.1. The statistically significant excess risk found for these two forms of cancer may be the result of multiple statistical testing rather than a phenomenon of true biologic significance. Thus psoriasis patients seem not to deviate from the general population with regard to cancer prevalence.

Prospective evaluation of serum CA 125 levels in a normal population, phase I: the specificities of single and serial determinations in testing for ovarian cancer

To determine the potential efficacy of the CA 125 assay as one component of a strategy for early detection of ovarian malignancy, serum CA 125 levels were determined in 1082 women 40 years of age or older in Stockholm. Initial serum CA 125 levels exceeded 35 U/ml in 36 women (3.3%) and 65 U/ml in 11 women (1.0%), placing the exact 95% upper confidence limits on false positive rates for a single screen at 4.3 and 1.7%, respectively. Follow-up CA 125 levels were obtained for those women with initially elevated levels and a group of age-matched controls. Mean CA 125 levels declined significantly for women with initially elevated levels (P = 0.0014). Interindividual variation and variation within individual subjects over the entire follow-up period were 52 and 35%, respectively. Of the 36 subjects with initially elevated serum CA 125 levels, only 2 showed a doubling of these levels; in only 1 of these 2 was this increase sustained. Intensive clinical follow-up with pelvic examination and ultrasonography, with investigators blinded to CA 125 results, led to the diagnosis of Stage III ovarian cancer in the latter individual. Diagnosis was made 21 months after the initially elevated serum CA 125 measurement and 15 months after the first measured doubling of that level. Because no other malignancies were identified at entry or during the follow-up period (median 560 days) in the women with elevated CA 125 levels, the specificity of the assay over that time period would have been 99.9% using the doubling of an initially elevated value as the criterion for determining positivity and 100% using as the criterion a sustained increase in level for those with initially elevated levels that doubled. These results support the continued investigation of longitudinally collected CA 125 levels to identify individuals at high risk for ovarian malignancy.

Pemphigoid and cancer

To evaluate the significance of the association of malignant disease with bullous pemphigoid, we reviewed 497 consecutive cases with positive immunofluorescence tests for circulating antibodies to basement membrane. We searched the Swedish Cancer Registry, Stockholm, Sweden, for records reporting malignancies in the study population (1958 to 1985), and the expected number of malignancies was calculated on the basis of age- and sex-standardized incidence data. In 61 patients, a total of 69 malignancies were diagnosed. The expected number of malignancies was 82.6. In 25 patients, a total of 27 malignancies appeared during the same year as the onset of pemphigoid, or later. The expected number was 35.8. The median titer of circulating antibodies in the 497 patients, in the 61 patients with malignancy, and in the 25 patients with malignancy preceded by the pemphigoid, were not significantly different. We conclude that pemphigoid is not statistically associated with malignancy, and that the former hypothesis of such an association was based on age only.