Usefulness of the codification of multiple causes of death in mortality statistics.

BACKGROUND: The codification of multiple causes of death began in the US in 1917 and systematic publication of this data started in 1984. In Spain this began in 1988, and the data from this year have been taken as the basis for investigation. They have also been studied for regional differences. METHODS: A representative sample (595) of Spanish Standard Death Certificates (DC) was collected in Asturias for the year 1988. All were coded according to the International Classification of Diseases and a separate coding was made for each nosological entity included in the certificate (coding of multiple causes). The median, mode and the multiple cause/underlying cause ratio were also calculated. RESULTS: More than 80% of the certificates studied contained more than one cause of death. Chronic diseases are those which are accompanied by a greater number of causes and acute diseases those which appear alone. The highest ratios appear for diseases which are ill defined and also in those which are chronic. CONCLUSIONS: Our data show that information is lost in the production of the statistics of mortality and there are repercussions for the usefulness of these statistics.

Hippocampal and entorhinal glucose metabolism in relation to cholinergic theta rhythm.

Hippocampal and entorhinal cortex glucose metabolism were studied by 14C-2-deoxyglucose (2-DG) autoradiography in anesthetized rats with and without continuous theta rhythm (theta). 2-Deoxyglucose changes in specific cytoarchitectonic regions were precisely assessed by n innovative approach. In the absence of theta there were areas with a higher glucose metabolism corresponding to neuropile regions at CA3, dentate gyrus, and subiculum, while the cellular layers always showed lower values. In the presence of theta, provoked by intraventricular injections of anticholinesterases (i.e., physostigmine) or curarimimetics (i.e., d-tubocurarine), 2-DG uptake showed two opposite significant changes in relation to controls: a) it increased in the outer zone of the molecular layer (inner blade) of the dentate gyrus, and in the stratum lacunosum-moleculare of CA3, suggesting an increase in perforant path input during theta rhythm; b) it decreased in the hilar dentate region. This noteworthy decrease in metabolic activity probably reflects an hilar inhibition by local circuits during theta rhythm generation.

Nocturnal and diurnal sleep in Macaca sylvana.

In Macaca sylvana restrained in chairs, continuous 24 h recordings were obtained of scalp EEG, neck EMG, bilateral EOG, motility of the head and lever manipulation. A total of 32 days were studied in 8 monkeys. Recordings were divided into epochs of 30 sec and analyzed in a PDP-12 computer. Four stages of sleep and 5 stages of wakefulness were identified by combination of the above data. Results were as follows: (1) During the night, there was 21% wakefulness and during the day 20% sleep, including a considerable amount of REM. (2) Recordings of spontaneous motility of head and hands proved an excellent indicator of sleep-wakefulness cycles. (3) Spectral analysis revealed the cyclic characteristics of non-REM sleep, with peaks at 360, 149, 72, and 55 min. (4) Stages of wakefulness had ultradian cycles, and stage W-2 was the most important in number and duration of occurrences. (5) Night wakefulness had characteristics different from day wakefulness. (6) Study of sequences showed that stage II was the least differentiated being transitional among the other stages, while stage III-IV was never preceded by wakefulness or REM, and almost always it followed stage II (99.0% of the time). (7) The high statistical significance of results obtained under restraint in different monkeys suggests that this situation has great potential value in the investigation of physiological mechanisms of ultradian rhythms.

Epidemiological study of gastroschisis and omphalocele in Spain.

We report an epidemiological study of gastroschisis and omphalocele performed through the Spanish Collaborative Study of Congenital Malformations. Among 264,502 live births analyzed from April 1976 to September 1981, 12 gastroschisis and 40 omphaloceles were identified. The overall incidence of gastroschisis was 0.4 per 10,000 live births and 1.5 for omphalocele. The incidence of gastroschisis showed a significant secular trend with a mean annual increase of 0.38 per 10,000 livebirths. The mean maternal age was 21.42, which is significantly lower than the control group (p less than 0.01). Among isolated omphaloceles the maternal ages showed a U-shape distribution. Maternal vaginal bleeding, gestational age, and birth weight were significantly different between gastroschisis and omphaloceles and the controls. Mortality within the first 3 days of life was significantly higher in gastroschisis, syndromic omphaloceles, and those associated with other malformations when compared to controls. No significant consanguinity or familial cases were observed for either gastroschisis or omphaloceles.

Lung cancer risk in iron and steel foundry workers: a nested case control study in Asturias, Spain.

BACKGROUND: Workers of iron and steel foundries have a high lung cancer risk but the findings on specific processes associated with this risk are inconsistent. We examined the risk of lung cancer among workers in the main industrial processes of a large iron and steel foundry in Asturias, Spain. METHODS: We conducted a nested case-control study comprised of 144 male lung cancer cases and 558 controls, selected from a study base of about 24,400 workers employed in the industry between 1952 and 1995. Cases were identified through linkage of industry records with those of two cancer registries. Controls were selected through industry records using incidence density sampling, were matched to cases by age and date of birth and had to be alive and without lung cancer at the time of selection. Smoking history was obtained through company medical records. Unconditional logistic regression was applied and all ORs were adjusted for age and tobacco consumption. RESULTS: Workers were, on an average, heavy smokers and a very strong relation was observed for smoking (OR for "ever smoker" = 32.4). Workers having ever been employed in the blast furnace had an excess lung cancer risk (OR = 2.55, 95% CI 1.25-5.21) compared to a reference group of workers not employed in metal producing departments. A similar excess was observed for workers having as their longest held job employment in the blast furnace. A two-fold risk was also observed for workers in the main foundry. For subgroups of workers, tobacco smoking appeared to be an important positive or negative confounder. CONCLUSIONS: In this large Spanish foundry, a high risk was observed for workers employed in departments with high exposure to crystalline silica, PAHs, and various other carcinogenic chemicals. Although comparisons were made between workers of the same industry, smoking habits differed and adjustment by smoking modified considerably the risk estimates.