Lung function measurements over 21 days shiftwork in steelworkers from a strandcasting department.

On the assumption that short term changes in lung function may reflect the potential for a long term decline the evolution of lung function indices in 25 steelworkers from a strandcasting department and in 11 comparable steelworkers not exposed to dust was investigated over an almost uninterrupted 21 day working period and over three different workshifts. The mean total dust level in the strandcasting department, assessed by personal sampling, was 11.8 mg/m3. All subjects were examined at the beginning, in the middle, and at the end of their first (day 1) morning shift (0600 to 1400), their last (day 14) afternoon shift (1400 to 2200), and their last (day 21) night shift (2200 to 0600). Indices measured were vital capacity (VC), forced expiratory volume in one second (FEV1) and in three seconds (FEV3), forced expiratory flow over the middle half of the forced vital capacity (FEF25-75), peak expiratory flow rate (PEFR), the slope of the N2 plateau (delta N2) and the closing volume (CV) of the single breath oxygen test. Differences in indices between initial values (0600 on day 1) and final values (0500 on day 21) were not significant in the control group (except delta N2 which became lower); in the casting group there were significant (p less than 0.05) decreases in FEF25-75 and FEV3, but these decreases were not significantly greater than in the control group. Lung function changes were not significant in either group over the morning shift. During the afternoon there were significant decreases in spirometric indices in the casting group, with no significant decreases in the control group, but the interactions between exposure and time were generally not significant. During the night shift, however, the decreases in FEV1 and FEF25-75 observed in the strandcasting group were significantly more pronounced than in the control group. The single breath test, which many subjects failed to perform correctly on each occasion, showed no significant changes in closing volumes, and an "improvement" of delta N2 over the morning and the night shift in the control but not the exposed subjects needs to be interpreted with caution. The more pronounced decrease in spirometric indices, suggestive of slight airways obstruction, found over the night shift in the strandcasting workers is attributed to their working environment.     

Assessing the power and quality of epidemiologic studies of asbestos-exposed populations

This paper briefly discusses criteria for evaluating epidemiologic studies for risk assessment purposes, using asbestos as an example. Asbestos is one of the few carcinogens for which substantial data exist on exposures to humans. However, there are major difficulties in using these data for conducting risk assessments. In particular, exposure data are often incomplete, and risk assessments usually involve extrapolating from the higher exposures of the occupational environments to the lower levels typically encountered in the nonoccupational environment. The term "asbestos" refers to the fibrous form of several minerals, and levels of exposures to these fibers are not easily assessed. Criteria for evaluating epidemiologic studies used in an Ontario Royal Commission report on asbestos are discussed. The importance of considering the statistical power of studies to detect an excess risk is examined using as examples major cohort studies of asbestos-exposed workers, as summarized in a report by the U.S. National Research Council.     

Analysis of neomycins A, B and C by high-performance liquid chromatography with post-column reaction detection

The analysis of the antibiotics neomycins A, B and C was investigated. The separation of the components was studied using reversed-phase and reversed-phase ion-pair chromatography. The optimum separation was obtained utilizing a Lichrosorb RP-2 column with a mobile phase consisting of 75 mg/l sodium dodecyl sulphate, 0.5M Na2SO4 and 0.015 M sodium acetate buffer at pH 7.0. Using this mobile phase, baseline separation was obtained for all three compounds in approximately 20 min. Detection was via post-column derivatization of the analytes with ortho-phthalaldehyde in the presence of mercaptoethanol to form fluorescent iso-indole products. This system is applied to the analysis of a number of formulated products containing neomycin.     

IUD insertion during cesarean section

An IUD (TCu220C) was inserted in 82 women during low-transverse cesarean section. No untoward effect on puerperal morbidity or lactation was observed and no serious complications occurred in this series. At 12 months the rates were zero for pregnancy and 7.7 for expulsion; the latter figure is comparable to that reported after immediate postplacental insertion of the same IUD model. Intracesarean IUD insertion is a procedure that deserves further promotion.

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Resumen A 82 mujeres se les insertó un DIU (TCu220C) durante una cesárea transversa en el segmento bajo. No se observaron efectos adversos en la morbilidad puerperal y la lactancia y no ocurrieron complicaciones serias en esta serie. A los 12 meses la tasa de embarazos fue de cero y de 7,7 la de expulsiones; esta última cifra es comparable a la registrada después de la inserción postparto inmediato del mismo modelo du DIU. Por lo tanto, la inserción intracesárea de DIU se considera un procedimiento que merece mayor promoción.

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Résumé Un dispositif intra-utérin (TCu220C) a été mis en place chez 82 femmes au cours d'une césarienne transverse basse. On a noté aucune répercussion défavorable sur la morbidité post-puerpérale ni sur l'allaitement et aucune complication sérieuse est apparue dans cette série. Au bout de douze mois, les fréquences étaient de zéro pour les grossesses et de 7,7 pour les expulsions. Les chiffres ultérieurs sont comparables à ce qui a été publié après insertion post-placentaire immédiate du même modèle de DIU. La mise en place d'un DIU au cours de la césarienne est une méthode qui mérite d'être plus largement répandue.

     

Comparison of three Multiload IUDs: MLCu250, MLCu375 and MLAgCu250

A comparative study was made of three differently loaded Multiload intrauterine contraceptive devices. The IUDs were used by 450 women for 3 years unless the device was removed earlier. The reasons for IUD removal (pregnancy, bleeding and/or pain, and other) were recorded, and the data analyzed after 1 year and after 3 years using the log-rank method. No statistically significant differences could be found among the three devices either in rate of pregnancy nor IUD removal for any reason.

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Resumen Se hizo un estudio comparativo de tres anticonceptivos intrauterinos Multiload con tres cargas diferentes. Durante tres años, 450 mujeres usaron los DIU a menos que el dispositivo hubiera sido quitado antes. Las razones para la remoción de los DIU (embarazo, sangrado y/o dolor y otras) fueron registradas y los datos se analizaron después de l año y de 3 años, usando el método log-rank. No se pudo encontrar ninguna diferencia estadísticamente significativa entre los tres dispositivos sea en la tasa de embarazos o en la remoción de los DIU por cualquier razón.

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Resumé On a conduit une étude pour comparer 3 DIU multichargés, de charge différente. Ces DIU ont été utilisés par 450 femmes pendant 3 ans, sauf retrait plus précoce. On a relevé les motifs de retrait du DIU (grossesse, hémorragie et/ou douleurs et autres motifs) et analysé les données au bout de 1 an et de 3 ans, par la méthode des rangs logarithmiques. Aucune différence statistiquement significative n'a été constatée entre les 3 DIU; ni sur le plan du taux de grossesse ni sur celui du taux de retrait, pour un motif quelconque.

     

Aortocaval fistula: CT appearance with angiographic correlation

As CT is often the initial imaging method in the evaluation of suspected complications of abdominal aortic aneurysm, especially rupture of the aneurysm, it is important to be aware of other less common complications that can be detected by CT. A patient with an aortocaval fistula and renal venous hypertension is discussed. The constellation of CT findings that suggest this diagnosis is described as is the angiographic correlation. Awareness of these CT findings, including early equivalent enhancement of the inferior vena cava and aorta; enlarged, poorly functioning kidney; and perirenal "cobwebs," will lead to the appropriate confirmatory angiographic studies.     

Seroepidemiological study on sexually transmitted diseases and hepatitis B in African promiscuous heterosexuals in relation to HTLV-III infection

A seroepidemiological study was performed on HTLV-III, T. pallidum, C. trachomatis and Hepatitis B virus (HBV), in Butare, Rwanda, among 33 female prostitutes, 25 male customers of prostitutes, and 60 male and female controls. As compared with female controls the prostitutes had a higher prevalence of antibodies to HTLV-III (29/33 versus 4/33, p<0.001), T. pallidunz (TPHA: 27/33 versus 6/33, p<0.001; RPR: 19/33 versus 233, p<0.001; FTA-Abs: 27/33 versus 5/33, p<0:001) and C. trachomatis (IgG IF: 31/33 versus 13/33, p<0.001). HBV serological markers were more often detected in the prostitutes than in the female controls (31/33 versus 18/33, p<0.001) although HBs antigen carriage rate was similar in both groups. As compared with male controls, the male customers of prostitutes had more frequently detectable antibodies to HTLV-III (7/25 versus 2/27, p = 0.05), and a positive RPR (10/25 versus 1/27, p<0.01). Among the 118 individuals studied, odds ratios and trend analysis disclosed a significant association between HTLV-III seropositivity and a positive TPHA, RPR, FTA-Abs, Chlamvdia IgG IF test and serological markers to HBV. No association was found between HTLV-III seropositivity and IIBs Ag carriage. This study suggests that HTLV-III has to be considered as an infectious agent transmitted among promiscuous Central African heterosexuals by sexual contact and/or parenteral contact with unsterile needles used for STD treatments.     

Total parenteral nutrition (TPN) and gallbladder diseases in neonates. Sonographic assessment

During a 1-year period, a prospective ultrasound (US) study of the biliary tract was performed in 41 neonates receiving total parenteral nutrition (TPN). Gallbladder sludge appeared in 18 neonates (44%) after a mean period of 10 days of TPN. The occurrence of this abnormality seems related to three main factors: prematurity with immaturity of the enterohepatic circulation of bile acids, duration of TPN, and lack of enteral nutrition. In five neonates (12%), an evolution of sludge to "sludge balls" was observed. Two neonates (5%) went on to develop uncomplicated gallstones and a spontaneous resolution occurred in one of them 6 months after the examination. This finding suggests conservative management in such cases. However, since cholecystitis or biliary tract obstruction are classical complications in older children, a US survey of neonates receiving TPN is useful to follow the abnormal gallbladder content, and rapid introduction of enteral feeding is advisable.     

Are eye movement evoked potentials different from pattern reversal evoked potentials?

The averaged lambda wave elicited by saccadic eye movements across a checkerboard pattern has been reported to differ from checkerboard reversal evoked reponses, even when the electroencephalographic responses were corrected for the artefact caused by the movement of the dipole moment of the eye itself. Because of these differences it was suggested that the recording of the lambda wave might provide extra information in pathological circumstances. We performed experiments in which the parameters of the pattern (high contrast checkerboard pattern, 20 checks, large field 72 × 72 degrees) shift across the retina were carefully adjusted. For instance, eye movements were made across an integer and odd number of checks in order to mimic the pattern reversal. Furthermore, the timing of the pattern movement in the pattern reversal condition was adjusted so as to simulate the saccadic eye movement. The results seem to suggest that the reported dissimilarities between pattern reversal and eye movement evoked responses can be accounted for by the small differences of the retinal shift in the two conditions.