Occupational exposure of deck crews to carcinogenic agents on crude oil tankers

Occupational exposure to carcinogenic agents on the decks on six Norwegian crude oil tankers was examined in five harbors. The purpose of the study was to evaluate the need for improving the working environment on deck on these tankers. Technical arrangments and the work itself on the deck were observed during loading or unloading. Occupational monitoring was performed by active sampling of benzene, polyaromatic hydrocarbons, and some aldehydes. The crew answered a questionnaire concerning their work, use of protective equipment, and occurrence of acute symptoms. The levels of air-borne carcinogenic agents were low, probably due to closed loading systems on all tankers. However, the seamen reported discomfort during the work that may be related to other chemical agents in the cargo. The seamen were frequently painting with lead chromate paint without using personal protective equipment. This type of chemical exposure should be evaluated.     

Transurethral resection versus transurethral incision of the prostate. A prospective randomized study

In this ongoing study, patients with an estimated prostate size of no more than 20 gm are randomized to undergo either transurethral resection of the prostate (TURP) or transurethral incision (TUIP) at the 6 o'clock position. To date, 93 patients have been included, and 3 months postoperatively, 80 to 90 per cent of the patients in each group reported improvement. There was also a significant decrease in symptom scores and a significant increase in maximum urinary flow rate, with great variation within each group but without difference between the groups. In both groups, there appears to be some deterioration over time. Operating time, estimated blood loss, time to catheter removal postoperatively, and duration of postoperative hospital stay were all significantly in favor of TUIP. Loss of ejaculation was reported by 37 per cent of patients after TURP and by 13 per cent after TUIP (not statistically significant). There was no difference between the groups in the need for further surgery. Therefore, TUIP is recommended as an alternative to TURP in patients with small prostates.     

Diagnostic and therapeutic problems in prostatitis. Therapeutic position of ofloxacin.

Lower tract localisation studies have been the gold standard in diagnosing various kinds of prostatitis. Four clinical categories are recognised: acute and chronic bacterial prostatitis, nonbacterial prostatitis, and prostatodynia. In acute bacterial prostatitis Gram-negative bacteria are the most common pathogens isolated. The roles of Gram-positive bacteria in chronic bacterial prostatitis and of Chlamydia trachomatis in nonbacterial prostatitis are contentious. Treatment of these various forms of prostatitis has been a challenge to the clinician. The lack of penetration of various drugs into the prostatic tissue, because of poor lipid solubility, ionisation, protein binding, and unfavourable pH gradients from the plasma to the prostatic fluid, may be the main reasons for poor results. The minimum inhibitory concentration (MIC) of antibacterial drugs used, and the concentration of drugs actually obtained in the prostate, combined with the influence of pH and inoculum size, and the effect of prostatic fluid and prostatic extracts on MIC are important factors in determining at least the theoretical efficacy of various drugs in the treatment of prostatitis. The new fluoroquinolone ofloxacin, the first quinolone to be approved for the treatment of chronic bacterial prostatis, has excellent penetration into human prostate and high in vitro activity in human urine and prostatic tissue. From a theoretical standpoint, ofloxacin should be ideal in the treatment of chronic bacterial prostatis. Comparative studies have shown its superiority to carbenicillin. Several noncomparative studies have also been reported. The initial results are promising, but further investigations are needed.     

Biological exposure limits estimated from relations between occupational styrene exposure during a workweek and excretion of mandelic and phenylglyoxylic acids in urine

Summary Styrene exposure of 18 workers in fiber-glass reinforced plastic industries was measured for 30-min periods throughout each workday for a week. The styrene uptake was estimated using pulmonary ventilation measurements. All urine voidings were collected separately and the styrene metabolites, mandelic acid (MA) and phenylglyoxylic acid (PGA) were determined. The relationship between both exposure and uptake versus excretion of these metabolites was studied. Styrene metabolite concentrations and excretion rates (with 95% tolerance limits) were calculated to correspond to a constant 8-h exposure at the Swedish exposure limit level (25 ppm) or an uptake of an exposure limit related styrene dose (6.3 mmol). The tightest tolerance limits were obtained for excretion rate of MA + PGA per 24 h. The calculated biological exposure limit was 3.4 (± 0.7) mmol MA + PGA/24 h for a dose of 6.3 mmol styrene.     

Is the risk of bipolar disorder in twins equal to the risk in singletons? A nationwide register-based study

BACKGROUND: A previous study demonstrated a higher rate of schizophrenia in dizygotic twins than in the general population, and a higher rate of schizophrenia in siblings of dizygotic twins than in siblings of monozygotic twins and singletons, pointing to a common genetic predisposition for dizygotic twinning and schizophrenia. The aim of the present study was to investigate whether these findings also apply to bipolar disorder. METHODS: Through record linkage between The Danish Twin Register, The Danish Psychiatric Central Register and The Danish Civil Registration System, the rate of bipolar disorder (diagnosed for the first time during admission to hospital) in dizygotic and monozygotic twins was compared with the rate in singletons, and the rate in siblings and parents of twins was compared with the rate in siblings and parents of singletons. RESULTS: The rate of bipolar disorder was the same in dizygotic twins, monozygotic twins and singletons as well as for parents and siblings of dizygotic twins, monozygotic twins and singletons. LIMITATIONS: The study is a register-based study, only including hospitalized patients. CONCLUSION: This study shows that there is an equal rate of bipolar disorder in twins and in singletons. Assuming that DZ twinning is under some genetic influence, a differential relationship between schizophrenia and DZ twinning on one hand and bipolar disorder and DZ twinning on the other hand may suggest differences in the genetic basis of the two diseases. The finding that the rate of bipolar disorder in monozygotic twins is the same as the rate of bipolar disorder in singletons supports studies finding no association between bipolar disorder and obstetric complications.     

Contraction-specific differences in maximal muscle power during stretch-shortening cycle movements in elderly males and females

Elderly people (age 75 years; n=48 males and 34 females) were studied in order to elucidate gender differences in elderly subjects on the determinants of muscle power (force and velocity) during a stretch-shortening cycle. All subjects performed three maximal counter-movement vertical jumps using both legs, on a force platform (Kistler 9281 B). The eccentric (Ep) and concentric (Cp) phases of the jumps were analyzed. The Ep was further divided into an acceleration phase (Ep_acc: from the start of the downward movement to the maximal negative velocity) and deceleration phase (Ep_dec: from the maximal negative velocity to the end of the downward movement). Jump height for the men was higher than for the women (P < 0.001). During both Ep_acc and Ep_dec no significant differences were observed between males and females in force and power generation. However, the men had a higher peak muscle power during the Cp, which may be explained exclusively by the velocity determinant (P < 0.001). No specific gender-related strategy appeared to influence the motor pattern of the movement. The comparable eccentric force generation of the leg extensors in both genders suggests a similar ability to cope with eccentric muscle actions during everyday activities. In contrast, the marked lower capacity for concentric contractions in women may result in an impaired performance, especially in activities where intense and rapid movements are essential, for example when reversing a forward fall. This may be one reason why elderly women are more prone to falls than are elderly men. Accepted: 19 September 2000     

Selective immunolesion of cholinergic neurons leads to long-term changes in 5-HT2A receptor levels in hippocampus and frontal cortex

Although loss of cholinergic neurons in the basal forebrain is considered a key initial feature in Alzheimer's disease (AD), changes in other transmitter systems, including serotonin and 5-HT_2A receptors, are also associated with early AD. The aim of this study was to investigate whether elimination of the cholinergic neurons in the basal forebrain directly affects 5-HT_2A receptor levels. For this purpose intraventricular injection of the selective immunotoxin 192 IgG-Saporin was given to rats in doses of either 2.5 or 5 μg. The rats were sacrificed after 1, 2, 4 and 20 weeks. 5-HT_2A protein levels were determined by western techniques in frontal cortex and hippocampus. A significant 70% downregulation in frontal cortex and a 100% upregulation in hippocampus of 5-HT_2A receptor levels were observed 20 weeks after the cholinergic lesion when using the highest dose of 192 IgG-Saporin. Our results show that cholinergic deafferentation leads to decreased frontal cortex and increased hippocampal 5-HT_2A receptor levels. This is probably a consequence of the interaction between the serotonergic and the cholinergic system that may vary depending on the brain region.     

Genomic approach to identification of Mycobacterium bovis diagnostic antigens in cattle

Differential delayed-type hypersensitivity skin testing with tuberculin purified protein derivatives from Mycobacterium bovis and M. avium is the standard for diagnosing bovine tuberculosis. However, improved tests based on defined, specific antigens are urgently needed. In the present study, a combination of bioinformatics, molecular biology, and bovine models of infection were used to screen mycobacterial proteins for their potential as diagnostic reagents which could be used in a whole-blood assay for diagnosis of tuberculosis. Initial screening of 28 proteins selected in silico and expressed as recombinants in Escherichia coli indicated that CFP-10, ESAT-6, TB27.4, TB16.2, TB15.8, and TB10.4 induced strong gamma interferon responses in experimentally infected cattle. A more thorough investigation over time in two groups of animals infected with a high (10(6) CFU) and a low (10(4) CFU) dose of M. bovis revealed that, for both groups, the strength of the in vitro response to individual antigens varied greatly over time. However, combining the results for ESAT-6, CFP-10, and TB27.4, possibly supplemented with TB10.4, gave sensitivities at different infection stages close to those obtained with M. bovis purified protein derivative. Importantly, while responsiveness to ESAT-6 and CFP-10 correlated strongly for individual samples, the same was not the case for ESAT-6 and TB27.4 responsiveness. The results suggest that combinations of specific antigens such as these have great potential in development of optimized diagnostic systems for bovine tuberculosis.