Persistence of Ebola virus in semen among Ebola virus disease survivors in Sierra Leone: A cohort study of frequency, duration, and risk factors.

BACKGROUND: Sexual transmission chains of Ebola virus (EBOV) have been verified and linked to EBOV RNA persistence in semen, post-recovery. The rate of semen persistence over time, including the average duration of persistence among Ebola virus disease (EVD) survivors, is not well known. This cohort study aimed to analyze population estimates of EBOV RNA persistence rates in semen over time, and associated risk factors in a population of survivors from Sierra Leone. METHODS AND FINDINGS: In this cohort study from May 2015 to April 2017 in Sierra Leone, recruitment was conducted in 2 phases; the first enrolled 100 male participants from the Western Area District in the capital of Freetown, and the second enrolled 120 men from the Western Area District and from Lungi, Port Loko District. Mean age of participants was 31 years. The men provided semen for testing, analyzed by quantitative reverse transcription PCR (qRT-PCR) for the presence of EBOV RNA. Follow-up occurred every 2 weeks until the endpoint, defined as 2 consecutive negative qRT-PCR results of semen specimen testing for EBOV RNA. Participants were matched with the Sierra Leone EVD case database to retrieve cycle threshold (Ct) values from the qRT-PCR analysis done in blood during acute disease. A purposive sampling strategy was used, and the included sample composition was compared to the national EVD survivor database to understand deviations from the general male survivor population. At 180 days (6 months) after Ebola treatment unit (ETU) discharge, the EBOV RNA semen positive rate was 75.4% (95% CI 66.9%-82.0%). The median persistence duration was 204 days, with 50% of men having cleared their semen of EBOV RNA after this time. At 270 days, persistence was 26.8% (95% CI 20.0%-34.2%), and at 360 days, 6.0% (95% CI 3.1%-10.2%). Longer persistence was significantly associated with severe acute disease, with probability of persistence in this population at 1 year at 10.1% (95% CI 4.6%-19.8%) compared to the probability approaching 0% for those with mild acute disease. Age showed a dose-response pattern, where the youngest men (≤25 years) were 3.17 (95% CI 1.60, 6.29) times more likely to be EBOV RNA negative in semen, and men aged 26-35 years were 1.85 (95% CI 1.04, 3.28) times more likely to be negative, than men aged >35 years. Among participants with both severe acute EVD and a higher age (>35 years), persistence remained above 20% (95% CI 6.0%-50.6%) at 1 year. Uptake of safe sex recommendations 3 months after ETU discharge was low among a third of survivors. The sample was largely representative of male survivors in Sierra Leone. A limitation of this study is the lack of knowledge about infectiousness. CONCLUSIONS: In this study we observed that EBOV RNA persistence in semen was a frequent phenomenon, with high population rates over time. This finding will inform forthcoming updated recommendations on risk reduction strategies relating to sexual transmission of EBOV. Our findings support implementation of a semen testing program as part of epidemic preparedness and response. Further, the results will enable planning of the magnitude of testing and targeted counseling needs over time.

First report of cerebellar abiotrophy in an Arabian foal from Argentina.

Evidence of cerebellar abiotrophy (CA) was found in a six-month-old Arabian filly with signs of incoordination, head tremor, wobbling, loss of balance and falling over, consistent with a cerebellar lesion. Normal hematology profile blood test and cerebrospinal fluid analysis excluded infectious encephalitis, and serological testing for Sarcocystis neurona was negative. The filly was euthanized. Postmortem X-ray radiography of the cervical cephalic region identified not abnormalities, discounting spinal trauma. The histopathological analysis of serial transverse cerebellar sections by electron microscopy revealed morphological characteristics of apoptotic cells with pyknotic nuclei and degenerate mitochondria, cytoplasmic condensation and areas with absence of Purkinje cells, matching with CA histopathological characteristics. The indirect DNA test for CA was positive in the filly, and DNA test confirmed the CA carrier state in the parents and the recessive inheritance of the disease. To our knowledge this is the first report of a CA case in Argentina.

Effectiveness of a 95 SNP panel for the screening of breed label fraud in the Chinese meat market.

Breed assignment has proved to be useful to control meat trade and protect the value of special productions. Meat-related frauds have been detected in China; therefore, 95 SNPs selected from the ISAG core panel were evaluated to develop an automated and technologically updated tool to screen breed label fraud in the Chinese meat market. A total of 271 animals from four Chinese yellow cattle (CYC) populations, six Bos taurus breeds, two Bos indicus and one composite were used. The allocation test distinguished European, Japanese and Zebu breeds, and two Chinese genetic components. It correctly allocated Japanese Black, Zebu and British breeds in 100, 90 and 89% of samples, respectively. CYC evidenced the Zebu, Holstein and Limousin introgression. The test did not detect CYC components in any of the 25 samples from Argentinean butchers. The method could be useful to certify Angus, Hereford and Japanese Black meat, but a modification in the panel would be needed to differentiate other breeds.

Foreign meat identification by DNA breed assignment for the Chinese market.

Methods for individual identification are usually employed for traceability, whereas breed identification is useful to detect commercial frauds. In this study, Chinese Yellow Cattle (CYC) samples plus data from six Bos taurus breeds, two Bos indicus breeds, and one composite breed were used to develop an allocation test based on 22 microsatellites. The test allowed discriminating all foreign breeds from the CYC, although some CYC individuals were wrongly allocated as Limousin or Holstein, probably due to the recent introduction of these breeds into China. In addition, CYC evidenced a previously reported Zebu cline (south-north) and a possible structure within the B. taurus component that should be confirmed. An independent test performed with meat samples of unknown breed origin from Argentina allocated 92% of them to either Angus, Hereford, or their crossbreed, but none was identified as CYC. We conclude that the test is a suitable tool to certify meat of foreign breed origin and to detect adulterations of CYC beef labeled as imported meat.

Hormonal regulation of pituitary FSH sialylation in male rats.

Sialic acid content in FSH is modulated by GnRH and sexual steroids. Galbeta1,3GlcNAcalpha2,3-sialyltransferase (ST3Gal III) and Galbeta1,4GlcNAcalpha2,6-sialyltransferase (ST6Gal I) incorporate sialic acid residues into FSH oligosaccharides. The aim of the present study was to assess pituitary FSH molecular microheterogeneity and ST3Gal III/ST6Gal I expression during sexual development and after castration in male rats. Preparative isoelectric focusing and lectin chromatography were used to isolate FSH glycosylation variants according to charge and complexity of their oligosaccharides; RT-PCR and immunohistochemistry were employed to analyse sialyltransferase expression. Sexual development was associated with a progressive shift towards more acidic/sialylated FSH glycoforms concomitantly with an increment in ST6Gal I gene and protein expression. After castration, a transient decrease followed by a marked increase in ST6Gal I expression were observed. Less acidic/sialylated FSH glycoforms bearing incomplete oligosaccharides increased after castration, despite high ST6Gal I expression. ST3Gal III expression remained unchanged in all the experimental conditions examined. These results show that the synthesis of FSH isoforms possessing alpha2,6-linked sialic acid is hormonally regulated in male rats.

Catch-up growth in intrauterine growth retarded rats: its correlation with histomorphometric changes of the pituitary somatotrope cells

The aim of the present study was to examinethe long-term effects of prenatal injure onbody and craniofacial growth in intrauterinegrowth retarded (IUGR) animals and its correlationwith histomorphometric changes ofthe pituitary somatotrope population. IUGRmodel was carried out by means of uterine vesselsligation in pregnant rats at 14th day ofpregnancy. Control and sham-operated animalswere also included. The animals were Xrayedat 1, 21, and 84 days of age. Bodyweight, neural and facial variables were measured.Pituitaries were processed for lightmicroscopy and immunolabeled with anti-GH sera. Morphometry was performed bymeans of an image-analysis system. Data wereprocessed by ANOVA, and Wilcoxon tests.Body weight was significantly lower in newbornIUGR rats compared with that of theircontrol counterparts, even during postnatalgrowth. Both neurocranium and face weresimilarly affected at birth and weaning. At 84days of age, despite facial growth exhibited apartial recovery, cranial volumes remainedsmaller in IUGR animals. Quantitativeimmunohistochemistry revealed a significantdecrease in the volume and cell densities inIUGR compared to control age peers. Adequatenutritional and environmental conditionswere insufficient to reverse the effects ofa reduced uteroplacental blood supply on fetalgrowth. The timing and duration of thegrowth insult seem to be crucial for the occurrenceof catch-up body weight and cranialgrowth in the rat. The lack of complete catchupin these IUGR animals may be associatedto an alteration in the GH production (AU)

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[Risk assessment of work-related upper limb musculoskeletal disorders in thirty factories in the upholstered furniture industry]. / Valutazione del rischio da movimenti e sforzi ripetuti degli arti superiori in trenta aziende del comparto del mobile imbottito.

BACKGROUND: One of the most common procedures for risk assessment of upper limb work-related musculoskeletal disorders (UL-WMSDs) in Italy is the OCRA synthetic index, which is recommended as the preferred method in the ISO standard 11228-3. OBJECTIVE: The aim of the survey was to assess the risk of UL-WMSDs due to repetitive strain and movements in thirty factories of the sofa industry located in a large geographic area of southern Italy. METHODS: The most characteristic working tasks of the manufacturing process were studied: filling preparation workers, leather-cutting operators, sewing and upholstery-assembly workers. The single tasks were carried out almost exclusively manually, with features of a handicraft approach. Data were collected through questionnaires and video tape recordings in each factory. The mean value of the OCRA index of every group of factories was calculated by weighting the values of the index of each single task group with the number of the workers. RESULTS: Figures obtained in the different factories showed values of the OCRA index ranging between 4 and 15. A 2,9 OCRA value was attributed to a low exposure group. CONCLUSIONS: Even though the work tasks analyzed were characterized by long duration of the manufacturing cycle (between 5 and 60 min), a particular but rigorous application of the OCRA procedures made it possible for a detailed risk assessment to be made for each of the working groups analysed.

[Manufacture of upholstered furniture and work-related upper limb musculoskeletal disorders: an industrial sector prevention project]. / Produzione del mobile imbottito: un progetto di ricerca finalizzato alla prevenzione delle patologie da sovraccarico biomeccanico degli arti superiori. Presentazione delle caratteristiche del comparto.

BACKGROUND: In cooperation with the IRCCS Fondazione Maugeri and the IRCCS Fondazione Ospedale Maggiore Policlinico - EPM-CEMOC, of Milan, the Local Health Unit in Bari, Italy carried out a research project, sponsored partly by the Italian Ministry of Health, on upper limb work-related musculoskeletal disorders (UL-WMSDs) in a specific manufacturing sector, the upholstered furniture industry. This "sofa district" is widely represented with approximately 14,000 workers and 500 factories over a wide geographic area of southern Italy. Advanced technology in the manufacturing process is combined with workers performing intensive arm-hand tasks. OBJECTIVES: The aim of the study included: a) assessment of exposure to repetitive strain and movements of the upper limb in a representative sample of the factories using the OCRA method, b) analysis of the annual prevalence and incidence rates, c) definition of possible improvement via ergonomic solutions in the various factories. METHODS: Via a network of occupational physicians a total of more than 6000 subjects were examined over a 5-year period. Case-definition was assessed through standardized procedures. RESULTS: A detailed description of the manufacturing process of the upholstered furniture industry and of the characteristics of the working population is provided Exposed groups at risk were:filling preparation workers, leather-cutting operators, sewing and upholstery-assembly workers. CONCLUSIONS: Data collected in private companies of different size in this extensive industrial "sofa area" emphasize the importance of prevention through adequate ergonomic solutions and the need to improve training programmes covering the whole area.

[Upper limb work-related musculoskeletal disorders (UL-WMSDs): a retrospective cohort study in three large factories of the upholstered furniture industry]. / Patologia da sovraccarico biomeccanico degli arti superiori: studio retrospettivo di coorte in tre grandi aziende del mobile imbottito.

BACKGROUND: The epidemiological evidence of work-related musculoskeletal disorders (UL-WMSDs) due to repetitive strain and movements in the various industries has been collected in the literature mainly through cross-sectional surveys. In particular there are no contributions so far regarding the upholstered furniture industry with a longitudinal design. OBJECTIVES: The aim of the study was to evaluate the incidence rate of WMSDs such as hand-wrist and shoulder tendonitis, carpal tunnel syndrome, and epicondylitis in exposed workers of three large companies of the upholstered furniture industry in a large geographic area of southern Italy. METHODS: The OCRA method, recommended by international standard ISO 11228-3 and EN 1005-5, was used for risk assessment. The following work tasks were considered:.filling preparation workers, leather-cutting operators, sewing and upholstery-assembly workers. A total population of 5,278 subjects (exposed n=2927, controls n=2351) was investigated. The person/year at risk parameters were calculated from 1 January 2000, or from the date of engagement if later, until the first diagnosis of WMSD or, in absence of disorders, until the end of the study, i.e. 31 December 2004. Disorders occurring after the first were not considered. A multiple regression analysis was used to evaluate relationships between rates. RESULTS AND CONCLUSIONS: Incidence rates correlated with risk classes of the OCRA index. An incidence rate of WMSDs higher than 1.2 cases per 100 person/year may be considered as a threshold value to suspect an occupational exposure to repetitive strain and movements warranting further investigation. The analysis of single factors did not show a greater predisposition of the female gender, with the single exception of the carpal tunnel syndrome (RR 2.92; 95% CI 1.57-5.43). Shoulder disorders affected mainly male leather-cutting operators (RR 4.97; 95% CI 2.03-12.16) and among all the factors influencing risk (frequency, force, posture, additional risk factors, pauses) posture seems to play a significant role.

[Prevalence of upper limb work-related musculoskeletal disorders (UL-WMSDs) in workers of the upholstered furniture industry]. / Prevalenza delle patologie da sovraccarico biomeccanico degli arti superiori negli addetti del comparto del mobile imbottito.

BACKGROUND: The upholstered furniture industry, the so-called "triangle of the sofa industry", is a geographic area of national and strategic economic importance in southern Italy. The single tasks are carried out mostly manually, with the characteristics of a handicraft approach. OBJECTIVES: The aim of the survey was to assess the prevalence of upper limb work-related musculoskeletal disorders (UL-WMSDs) in 30 factories of the sofa industry located in a large geographic area of the Puglia and Basilicata Regions. METHODS: In the period 1 January-31 December 2003 a network of occupational physicians investigated a population of 5.477 subjects (exposed n=3481, controls n=1996, M=3865, F=1612) in 30 different factories of the area. More than 60 percent of the total workforce studied was employed in large-sized companies (>500 employees). The following work tasks were considered: filling preparation workers, leather-cutting operators, sewing and upholstery-assembly workers. Case-definition was assessed through standardized procedures: symptoms by questionnaire plus physical and laboratory/imaging findings. RESULTS: Cumulative prevalence rates of UL-WMSDs as at 31 December 2003 reached values of up to 30% in high risk groups. Prevalence rates showed good correlation with the concise OCRA index used for assessment of exposure to repetitive strain and movements of the upper limb. The most frequently occurring disorders were tendon-related cysts and wrist tendonitis. Shoulder disorders were more frequent in male and female leather-cutting operators. CONCLUSIONS: This survey showed a significantly high prevalence of UL-WMSDs in sofa industry workers. It did not seem to be confirmed in this study that there was a greater female susceptibility to UL-WMSDs with the exception of carpal tunnel syndrome: gender difference seems to be less relevant at increasing levels of occupational exposure to repetitive movements and exertion of the upper limbs.

[From mandatory to participatory prevention: a model applied to the upholstered furniture industry]. / Dalla prevenzione imposta alla prevenzione partecipata: un modello applicativo nel comparto del mobile imbottito.

BACKGROUND: The Italian 2006-2008 National Health Plan emphasizes synergy and cooperation between the agencies formally involved in the prevention of occupational risks, in agreement with social partners. The so-called 'triangle of the sofa industry' is an interregional geographic area south-west of Bari, Italy. In 2003 this area produced 16% of the world-wide upholstered furniture output, with more than 500 plants of varying size. OBJECTIVE: The aim was to set up a network of communication and cooperation between the competent Agencies and Regions in order to address the rising trend of upper limb work-related musculoskeletal disorders. METHODS: The first step of the National Health Service Unit in Bari was to assess risk via a Ministerial research project and implement various information campaigns involving institutions, occupational physicians, private companies and public opinion. In a subsequent phase a synergy between the local Departmenst ofPrevention of the different Regions, the Italian Institute for Insurance Occupational Accidents and Disease (INAIL), the trade unions and the upholstered furniture industry Association was established. RESULTS AND CONCLUSIONS: New joint experimental projects (cutting tools, ergonomic table for assemblers, instruments for isokinetic evaluation) were launched together with training programmes for management, safety technicians and workers. This kind of 'participatory prevention' is more appropriate for the goal of a collaborative effort in order to assist the companies, which is a modern interpretation of the mission of public health prevention operators.

[Educational health programs in the construction industry of the Apulia Region, southern Italy]. / Percorsi formativi in edilizia nel territorio dell'AUSL BA/3, Regione Puglia.

31,000 building firms have been registered in the Apulia Region of Southern Italy, and 13.5% are concentrated in the area of the Local Health Bari/3. Especially small and middle-size firms (90% of total number) are assisted with information programs through dedicated local office. Educational and medical audit advanced programs carried out among occupational health professionals are described. A 'pilot project' for the regional health surveillance program in the construction industry is presented.

[Radiological and functional progression in silicosis]. / Progressione radiologica e funzionale nella silicosi.

BACKGROUND: The incidence of silicosis has decreased today because of a clear improvement of working conditions. According to recent data from Italian National Compensation Agency (INAIL) silicosis represents more than 5% of occupational diseases claimed for annually. Since silicosis is an evolving chronic disease, it has serious consequences on patient health, modifying the quality of life and increasing public costs. Some studies show a relationship between occupational exposure to silica and radiological and functional deterioration, but the results are not satisfactory because of the variety of clinical patterns and the interference of many risk factors. OBJECTIVES: The aim of our investigation was to evaluate silicosis evolution in relation to living habits and to different occupational exposures. METHODS: All admissions from 1980 to 2000 in the Occupational Medicine Unit of the Maugeri Foundation in Cassano Murge (Bari), Southern Italy, with final diagnosis of silicosis were examined. From 586 medical records gathered, subjects with double admissions were selected and their chest radiographs and FVC, FEV1 from lung function test were detected. No industrial hygiene data were available and individual exposure was estimated through calculation of a global exposure index. RESULTS: On the basis of data quality control, 106 consecutive male patients were recruited (age at first admission 51.7 +/- 8.3 years, occupational exposure at second admission 23.8 +/- 9.1 years). More than 50% of the subjects had an estimated high risk exposure at work. The first diagnosis of silicosis was made at first admission in 40% of the cases, 33% of the patients had been suffering from silicosis for 10 years while 27% for more than 10 years. Chest radiographs showed mostly p, q nodular pattern, and over a 4. 7 +/- 3.3 year follow-up period they appeared largely unchanged, although 8 radiographs showed confluent areas, 18 subjects showed pleural thickening, 10 calcified opacities, 17 COPD (Chronic Obstructive Pulmonary Disease) with emphysema, 2 tubercolosis lesions, 4 radiographic abnormalities attributable to cancer (3 lung, 1 oesophageal). CONCLUSIONS: The mainly stationary results of chest radiographs and the slight loss of respiratory function we observed confirm the slow evolution over time of silicosis. Multiple logistic regression analysis of main risk factors showed that subjects with radiographic opacities having a diameter greater than 10 mm or conglomerate shadows at the time of diagnosis seem to have a lower risk of progression of the disease after a relatively short period of follow up, even in mining related exposure.

Glucocorticoid-induced apoptosis in lymphoid organs is associated with a delayed increase in circulating deoxyribonucleic acid.

Pathological processes like cancer, chronic inflammation and autoimmune phenomena, all of which involve massive cell death, are associated with significant increases in circulating DNA. In order to clarify whether massive apoptosis occurring under physiological circumstances also causes DNA release into the circulation, we correlated the time-course of dexamethasone-induced intra thymic cell apoptosis with plasma DNA dynamics in rats. Animals were given 10 mg/l dexamethasone in their drinking water for up to 7 days. Sequential plasma samples were obtained during the treatment and DNA was quantitated by a micro fluorometric assay. Thymus and spleen weight as well as apoptotic cell levels were assessed at different times. Seven days of glucocorticoid treatment reduced thymic and spleen mass by 82 and 31%, respectively. Intra thymic apoptosis was maximal 24 h after the beginning of glucocorticoid treatment, declining markedly by 48 h. Very little apoptosis was observed in the spleen. Plasma DNA increased steadily during the first 4 days of glucocorticoid treatment (11.8 +/- 1.2 microg/ml on day 0; 24.2 +/- 1.6 microg/ml on day 4) beginning to decline afterward. Thymectomy but not splenectomy, drastically reduced the glucocorticoid-induced increase in plasma DNA. It is concluded that hormone-induced massive intra thymic cell death is followed by a delayed release of nucleosomal DNA into the circulation.

[Changes in the radiologic and spirometric profile in subjects with pulmonary silicosis]. / Evoluzione del quadro radiologico e spirometrico in soggetti affetti da silicosi polmonare.

All admissions with diagnosis of silicosis from 1980 to 2000, in the Occupational Medicine Division of Fondazione S. Maugeri, Cassano Murge (Bari), were examined. From 586 gathered medical records we selected 106 subjects with double admissions and detected their X-rays of chest, FVC and FEV1. The stationary results of their chest X-rays and the light declines of their respiratory functions confirm the slow evolution in time of this pathology.

[Occupational asthma and biological damage: adequate compensation?]. / Asma professionale e danno biologico: tutela privilegiata?

The evaluation of the damage to biological and relational capacities of the subject is the novel approach of the Italian Insurance Regulation Decree N(o) 38/2000 for compensating occupational asthma (OA). In this study we aimed to apply retrospectively the novel rating system to mild OA. From a data base of 201 diagnosis of OA collected in the 1987-97 decade 85 eligible consecutive cases of mild asthma according to the criteria of NIH/WHO guidelines on asthma were studied. Records on compensation were documented for 41 subjects. The average difference between novel scales and the actual rating individually assessed by Italian National Agency for compensation through criteria used at that time was 45.6 +/- 20%. The average difference between novel scales and rating calculated with guidelines considering the measurement of non-specific bronchial hyperreactivity developed by international experts and American Thoracic Society, endorsed by American Medical Association, was 41.5 +/- 12%. Within the actual rating individually assessed with previous Italian Insurance criteria no significant relationship (r=-0.20, p=0.2) was shown with bronchial responsiveness to methacoline expressed as provocative dose causing a 20% fall in FEV1 (PD20FEV1 microg of mch). A significant (p<0.05) relationship was observed with age at the time of OA diagnosis (r=0.37, p=0.017) and with duration of exposure (r=0.34, p=0.034). This study suggests that scales of the Insurance Regulation Decree N(o) 38/2000 grading mild OA underevaluate biological damage/impairment with reference both to previous practice in Italy and to international criteria guidelines. Among the parameters of evaluation methacoline challenge should be considered an adequate tool in measuring biological damage in OA for medicolegal purpose.

60 Hz magnetic fields and central cholinergic activity: effects of exposure intensity and duration.

In previous research, we have found that acute exposure to a 60 Hz magnetic field caused a decrease in cholinergic activity in the frontal cortex and hippocampus of the rat. In the present study, the effects of exposure to different intensities of the magnetic field and durations of exposure were investigated. Rats were exposed to a 60 Hz magnetic field for 60 min at a flux density of either 0.5, 1.0, 1.5, or 2.0 mT. A significant decrease in cholinergic activity was observed in the frontal cortex and hippocampus immediately after exposure to the 2.0 mT field. No significant effect was observed at lower intensities. In another experiment, effect of exposure to a 1.0 mT magnetic field for 30, 45, 60, and 90 min was investigated. A decrease in cholinergic activity was found in both brain areas after 90 min of exposure. No significant effect was observed after shorter durations of exposure. In a further experiment, the exposure duration was extended to 3 h at flux densities of 0.5, 0.1, and 0.05 mT. A significant decrease in cholinergic activity was observed in the frontal cortex and hippocampus of the rat immediately after exposure to all the intensities. It is concluded that the intensity and duration of exposure interact. By increasing the duration of exposure, effects can be observed at lower intensities.

Intracerebroventricular injection of mu- and delta-opiate receptor antagonists block 60 Hz magnetic field-induced decreases in cholinergic activity in the frontal cortex and hippocampus of the rat.

In previous research, we have found that acute exposure to a 60 Hz magnetic field decreased cholinergic activity in the frontal cortex and hippocampus of the rat as measured by sodium-dependent high-affinity choline uptake activity. We concluded that the effect was mediated by endogenous opioids inside the brain because it could be blocked by pretreatment of rats before magnetic field exposure with the opiate antagonist naltrexone, but not by the peripheral antagonist naloxone methiodide. In the present study, the involvement of opiate receptor subtypes was investigated. Rats were pretreated by intracerebroventricular injection of the mu-opiate receptor antagonist, beta-funaltrexamine, or the delta-opiate receptor antagonist, naltrindole, before exposure to a 60 Hz magnetic field (2 mT, 1 hour). It was found that the effects of magnetic field on high-affinity choline uptake in the frontal cortex and hippocampus were blocked by the drug treatments. These data indicate that both mu- and delta-opiate receptors in the brain are involved in the magnetic field-induced decreases in cholinergic activity in the frontal cortex and hippocampus of the rat.