An epidemiologic study of risk factors in two teenage suicide clusters

Two clusters of teenage suicides occurred in Texas between February 1983 and October 1984. The eight suicides from the first cluster and the six from the second were investigated together in a case-control study using a closed-response questionnaire administered to parents. Three control teenagers were matched with each case subject on the basis of school district, grade, race, and sex. Questions concerned the direct and indirect exposures of subjects to previous suicides as well as their life circumstances and behaviors. Case subjects were not more likely than control subjects to have had direct exposure to suicide as measured by their acquaintance with a person who committed suicide. Similarly, indirect exposure to suicide through the media was not associated significantly with suicide. Case subjects were more likely to have attempted or threatened suicide previously, to have damaged themselves physically, and to have known someone closely who died violently. Case subjects were more likely to have broken up with their girlfriends or boyfriends recently. They also had moved more often than control subjects, attended more schools, and lived with more parent figures. Identification of high-risk youths through knowledge of relevant risk factors can help to direct preventive services to those young people most susceptible to suicide.

Functional relationships and structural determinants of two bacteriophage T4 lysozymes: a soluble (gene e) and a baseplate-associated (gene 5) protein

Lysozymes have proved useful for analyzing the relation between protein structure and function and evolution. In bacteriophage T4, the major soluble lysozyme is the product of the e gene, gpe (gene product = gp). This lysozyme destroys the wall of its host, Escherichia coli, at the end of infection to release progeny particles. Phage T4 contains two additional lysozymes that facilitate penetration of the baseplates into host cell walls during adsorption. At least one of these, a 44-kD protein, is encoded by gene 5. We show here that a segment of the gp5 lysozyme amino acid sequence, deduced from the DNA sequence of gene 5, is remarkably similar to that of the T4 gene e lysozyme. Both T4 lysozymes are somewhat similar to the lysozyme of the Salmonella phage P22, but there is little significant DNA sequence homology among the two T4 lysozyme genes and the P22 lysozyme gene. We speculate that these lysozymes are adapted to differences in the composition of the cell walls of E. coli and S. typhimurium. The cloned gene 5 of the phage T4 directs synthesis of a 63-kD precursor protein that is approximately 19 kD larger than the gene 5 protein isolated from baseplates. Gp5 first associates with gp26 to form the central hub of this structure.(ABSTRACT TRUNCATED AT 250 WORDS)

The tangible cost implications of a hospital outbreak of multiply-resistant Salmonella

A hospital outbreak of multiply-resistant Salmonella heidelberg infection, which affected 17 patients and 2 staff, is described. The tangible cost of the outbreak was estimated at 21 pounds 151, 17 pounds 989 (85.1%) of which was borne by the hospital. The cost to the Microbiology Department was 3596 pounds (17.0% of the total). A detailed analysis of the costs and implications for staffing disruption is given and a comparison is made with the costs of preventive activities. Ways of containing expenses in the event of an outbreak and the economic implications for clinical budgeting and privatization of the laboratory service are considered.

[The extra-peritoneal approach in the surgical treatment of atherosclerosis in the aorto-iliac region]

Based upon a series of 27 cases the results obtained with the extraperitoneal approach for the surgical management of atherosclerosis of the aorto-iliac segment, are presented and discussed. The patients, ranging in age from 55 to 87 years (mean 70.9 years) were considered as high risk patients because of associated respiratory, cardiac and renal diseases. The technique of extraperitoneal approach was applied in 8 cases (29.7%) of abdominal aortic aneurysms (AAA), and 19 cases (70.3%) of aorto-iliac occlusive disease (DOAI), with an operative mortality of 3.7%. It has been concluded that the extraperitoneal approach is an attractive alternative to the conventional transabdominal approach, particularly in those patients with significant risk factors, requiring aorto-iliac surgical reconstruction.

Carotid artery injuries: experience with 124 cases

This is a retrospective study of 124 patients with carotid injuries. The common carotid artery was injured in 84% of the patients. Associated trauma to the internal jugular vein was present in 26%. Most patients (56%) were dead on arrival to the hospital and of those who were operated on, the mortality was 22% (overall mortality, 66%). All operative mortalities had severe shock or neurologic deficits on admission. We performed repair on all patients with preoperative neurologic deficits and the mortality was 64%. The use of a shunt did not influence the prognosis. We believe that there is no place for an emergency angiogram in order to diagnose a carotid injury or to plan the operation.

Surgical approaches to vertebral artery injuries

Twenty patients with penetrating injuries of the vertebral artery who were treated as emergencies were subjected to the following operative approaches: five cases, Henry's approach (posterior) and modified Henry's approach (anterior); five cases, limited exposure and application of metal clips; four cases, plugging of the arterial defect with Oxycell or crushed muscle; three cases, control with ligatures and non-conventional exposure of the artery; one case, inflation of a balloon catheter within the vertebral canal; one case, repair of the lacerated first extraosseous part of the vertebral artery. One patient died from exsanguination on the operating table, before any repair was possible. The overall mortality was 20 per cent and the mean hospital stay 6.1 days. Thirty-five per cent of the patients presented with neurological complications, and 55 per cent left the hospital well. No advantage of Henry's classical approach over limited exposure and control with metal clips was shown, when mortality, hospital stay and long-term problems were compared. Because of its relative simplicity we suggest that the metal clipping of the vertebral artery, above and below the site of injury, is an effective technique that can be used to stop the bleeding. One case presented as a false aneurysm of the vertebral artery, following a stab wound. This was successfully treated with excision of the aneurysm and vertebrovertebral artery bypass, using a saphenous vein graft.

Subclavian vascular injuries

This study comprises 228 patients with penetrating injuries of the subclavian vessels. The vein alone was involved in 44 per cent, the artery alone in 39 per cent, and both vessels in 17 per cent. The majority of the victims (61 per cent) did not reach the hospital alive, and in those who were operated on the mortality was 15.5 per cent (overall mortality 66 per cent). The overall mortality of venous injuries was significantly higher than the arterial ones (P less than 0.01), probably because of the dangerous complication of air embolism. Physical examination is reliable in the diagnosis of these injuries and there is no need for an emergency angiogram. The clavicular incision was the preferred approach. Repair was performed in 94 per cent of those with arterial injury. Vein injuries were treated by suture in 60 per cent and ligation in 40 per cent. A selective conservative approach is advised.

Prediction of preterm birth

The aim of this study was to assess the value of screening of cervical status in normal as well as in pregnancies with risk factors. 1327 pregnancies were studied prospectively; 16% had a medical history of earlier obstetrical or gynecological complications (group I) and 6% had complications during the first 24 weeks of the current pregnancy (group II). The remainder were considered low-risk pregnancies and randomly divided into groups III and IV. In groups I, II and III cervical scoring in accordance with Westin was performed in weeks 24, 28 and 32. The incidence of births before 37 weeks of gestation was 5.6% in group I, 8.8% in group II, 1.5% in group III and 0.7% in group IV. In presence of the risk factors, 61% of the spontaneous preterm deliveries were predicted early in pregnancy. The predictive value of a normal cervical score was high (about 95%) in all groups. In uncomplicated pregnancies the predictive value of a pathological score was only 4% and for cervical dilatation, 6%. In the risk groups the predictive value of a pathological cervix was 3-5-fold higher. Cervical examination in low-risk pregnancies does not improve prediction of preterms but is a complement in a system for indication for preterm delivery in women with defined risk factors.

Relation of age at onset to duration of episode in unipolar depression

The purpose of this study was to test the hypothesis that the duration of episodes of unipolar depression increases with age at onset. On the basis of elevated scores on a self-report depression measure, 2,020 persons were selected from a larger community sample to be interviewed and diagnosed using the Schedule for Affective Disorders and Schizophrenia-Research Diagnostic Criteria procedures. Of the 2,020 persons, 865 had a history of one or more episodes of unipolar depression. The potential effects of the following variables (singly and in interaction) on duration of episode were assessed by means of multiway frequency table analysis and chi-square: age at onset, sex of subject, interval since occurrence of the episode, and type of disorder (major vs. minor depressive disorder). The hypothesis that duration of episodes of depression increases with age at onset was not supported. Women were more likely to have multiple episodes, but did not have longer lasting episodes.

Relation of age at onset to duration of episode in unipolar depression

The purpose of this study was to test the hypothesis that the duration of episodes of unipolar depression increases with age at onset. On the basis of elevated scores on a self-report depression measure, 2,020 persons were selected from a larger community sample to be interviewed and diagnosed using the Schedule for Affective Disorders and Schizophrenia-Research Diagnostic Criteria procedures. Of the 2,020 persons, 865 had a history of one or more episodes of unipolar depression. The potential effects of the following variables (singly and in interaction) on duration of episode were assessed by means of multiway frequency table analysis and chi-square: age at onset, sex of subject, interval since occurrence of the episode, and type of disorder (major vs. minor depressive disorder). The hypothesis that duration of episodes of depression increases with age at onset was not supported. Women were more likely to have multiple episodes, but did not have longer lasting episodes.

Studies of zinc metabolism in pregnant and lactating rats

The metabolism of 65Zn administered intramuscularly (Expt 1) or enterally (Expt 2) at the beginning of pregnancy in rats given a control or marginal-Zn diet was measured. In Expt 2 a comparison was also made between pregnant and non-pregnant rats. The loss of 65Zn (assumed to represent labile body Zn) was markedly reduced in animals fed on a marginal-Zn diet compared with controls, and this effect occurred very rapidly, i.e. within 48 h of introducing the marginal-Zn diet. Pregnancy itself had a much less important effect on 65Zn turnover than diet. Transfer of 65Zn to the litter was significantly greater in the animals fed on a marginal-Zn diet compared with controls but total Zn transfer was reduced. The effect of length of time on a marginal-Zn diet on fetal growth and composition was examined. Compared with controls, fetal weight was significantly greater in litters from mothers fed on a marginal-Zn diet during the last 4, 7 or 14 d of pregnancy, but no different in litters from mothers fed on a marginal-Zn diet throughout pregnancy. There were no differences in the proportions of protein or fat in the fetuses from mothers fed on the control or marginal-Zn diets but the Zn concentration was lower in litters from mothers fed on a marginal-Zn diet during part or all of the pregnancy when compared with controls. The transfer of 65Zn from mothers to litters during birth and the first 3 d of lactation was measured. There were no differences in maternal or litter 65Zn just before or just after birth, but within 72 h maternal 65Zn had significantly decreased and litter 65Zn increased. Increases in litter size were associated with greater total litter 65Zn but reduced individual fetal 65Zn. These experiments demonstrate the importance of an adequate daily supply of Zn during pregnancy. Although there is room for adaptation to a marginal-Zn intake (by reducing Zn excretion) the maintenance of Zn homeostasis is only possible in the absence of other forms of stress, such as pregnancy, to the body. The consequence of insufficient Zn at times of rapid fetal growth on carbohydrate and lipid metabolism warrants further investigation.

Percutaneous nephrostolithotomy vs open surgery for renal calculi. A comparative study

To evaluate the impact of the percutaneous removal of renal calculi we compared 41 patients who had undergone open renal surgery to 88 patients who had a one- or two-stage percutaneous nephrostolithotomy for symptomatic urolithiasis. The two groups were similar with regard to stone size, stone location, treatment success, and complication rates. However, for patients with calculi 2.5 cm or smaller in diameter, the percutaneous procedure resulted in lower postoperative morbidity, more rapid convalescence, less hospital cost, and greater patient satisfaction. For patients with calculi larger than 2.5 cm in diameter, the percutaneous approach was slightly more expensive than open surgery but resulted in a markedly shortened convalescent period. In our experience, percutaneous nephrostolithotomy performed in a single stage under assisted local anesthesia was the most efficacious and least expensive of the percutaneous approaches.