Occupational exposure to whole body vibrations and birth outcomes - A nationwide cohort study of Swedish women.

BACKGROUND: More women in reproductive ages are entering occupations where exposure to whole body vibrations (WBV) is common (e.g. in transportation and construction). Previous studies based on self-assessed exposure suggest increased risks of adverse birth outcomes, but it is unclear at what exposure levels and if the current exposure guidelines are appropriate during pregnancy. OBJECTIVES: To investigate whether occupational WBV-exposure increases the risk of preterm birth, low birth weight, and/or small-for-gestational age, in a large, nationwide, prospective, cohort study. DESIGN: The Fetal Air Pollution Exposure cohort (FAIR) was formed by merging data from multiple, national registers, and the present study includes singletons born 1994-2014 to working women in Sweden (n = 1,091,080 births). WBV-exposure was assessed quantitatively using a job-exposure matrix based on measurements, and calculated odds ratios were adjusted for potential confounders such as smoking and BMI, and other occupational exposures like noise, combustion particles, and physically and psychologically strenuous work. Data on absence from work (full-/part time, sick leave, parental leave, etc.) was also used. RESULTS: Exposure to WBV during pregnancy, among women with low absence from work (n = 476,419), was associated with an increased risk of preterm birth, below the occupational exposure limit (1.15 m/s2). Compared to unexposed mothers, the OR was 1.38 (95% CI: 1.05, 1.83) for exposure ≥0.5 m/s2, corresponding to an increase from 47/1000 cases to 65/1000 cases. No increased risk was found for small-for-gestational age. CONCLUSIONS: Exposure to WBV was associated with an increased risk of preterm birth. The results suggest that the current permissible exposure and action levels for WBV-exposure do not adequately protect pregnant women with continuous exposure.

Does tobacco smoking influence the occurrence of hand eczema?

BACKGROUND: Tobacco smoking is known to influence various inflammatory skin diseases and an association between tobacco smoking and hand eczema has been proposed in some studies. OBJECTIVES: To examine a possible association between reported current tobacco smoking and the occurrence of hand eczema. SUBJECTS AND METHODS: Previously collected questionnaire data on the occurrence of hand eczema in three occupational cohorts and corresponding controls from the general population were studied. The questionnaires used included questions on 1-year prevalence of hand eczema and questions on smoking habits. For one occupational group, hairdressers and their controls, information on amount of smoking was obtained. Information on age, sex and history of atopy was also available. RESULTS: In total, answers regarding smoking and hand eczema were obtained from 13,452 individuals. Out of 3493 smokers, 437 (12.5%) reported hand eczema compared with 1294 out of 9959 nonsmokers (13.0%) (P = 0.51). With regard to the number of cigarettes smoked, 22.6% of the hairdressers smoking more than 10 cigarettes per day reported hand eczema compared with 17.4% of those smoking 0-10 cigarettes per day (P = 0.01). Corresponding figures for the controls were 14.5% and 11.7%, respectively (P = 0.06). CONCLUSIONS: No clear association was found between 1-year prevalence of hand eczema and smoking. Heavy smoking, more than 10 cigarettes per day, may give a slightly increased risk of hand eczema. Further studies with information on the amount of tobacco consumption and on possible confounders are needed to evaluate smoking as a risk factor for hand eczema.

Pooled analysis of clinical and cytogenetic features in treatment-related and de novo adult acute myeloid leukemia and myelodysplastic syndromes based on a consecutive series of 761 patients analyzed 1976-1993 and on 5098 unselected cases reported in the literature 1974-2001.

To ascertain the frequency of treatment-related acute myeloid leukemias and myelodysplastic syndromes (t-AML/t-MDS) in an unselected series, we have identified all adult cases analyzed in our department from 1976 to 1993. Further aims were to compare karyotypic features of t-AML/t-MDS with de novo AML/MDS, in our material as well as in 5098 unselected, cyto- genetically abnormal, published cases, and to analyze associations between type of prior therapy and karyotype. Among our 372 AML and 389 MDS, 47 (13%) were t-AML and 62 (16%) were t-MDS. Clonal abnormalities were significantly more common in t-AML and t-MDS than in de novo disease (68% vs 50%, P < 0.05 and 84% vs 45%, P < 0.001, respectively). Among the available 4230 AML and 1629 MDS (the present series and published cases), 14% were t-AML and 15% were t-MDS. In t-AML/t-MDS, the number of anomalies and the ploidy levels differed significantly from de novo cases, with complex and hypodiploid karyotypes being more common in t-AML/t-MDS. In t-AML, unbalanced changes in general, t(1;3), der(1;7), 3p-, -5, 5q-, -7, 7q-, t(9;11), t(11;19), t(11q23), der(12p), -17, der(17p), -18, and -21 were significantly more frequent than in de novo AML. In t-MDS, -5, -7, 7q-, 13q-, der(17p), and -18 were significantly more common. Type of prior treatment correlated significantly with number of anomalies in t-AML and with ploidy levels in t-AML/t-MDS. The frequencies of several aberrations varied with type of therapy, eg, 5q- was more frequent in radiotherapy-associated t-MDS, monosomy 7 was more common in t-AML and t-MDS after treatment with alkylators, and t(11q23) in t-AML was associated with topoisomerase II inhibitors. Abnormalities significantly more common in de novo disease were +8 as a sole anomaly, balanced changes in general, t(8;21), t(9;22), t(15;17), inv(16), and t(21q22) in AML, and -Y, 5q-, and 20q- as sole anomalies and +8 in MDS. The results emphasize the strong association between previous genotoxic exposure and karyotypic features.

Survival time in a population-based consecutive series of adult acute myeloid leukemia--the prognostic impact of karyotype during the time period 1976-1993.

A consecutive population-based series of 372 adult acute myeloid leukemias, successfully cytogenetically investigated at a single center between 1976 and 1993, is reported. All medical records were reviewed in order to ascertain the prognostic impact of karyotype, divided into three groups; favorable (t(8;21), t(15;17), and inv(16) irrespective of karyotypic complexity; n = 40), poor (der(1;7), inv(3), -5, del(5q), -7, t(9;22), and complex karyotypes including whole or partial losses of chromosomes 5 and/or 7; n = 56), and intermediate (other abnormalities or normal karyotype; n = 276). The possible modification by age, gender, time period, morphologic subtype, and bone marrow transplantation (BMT) on this prognostic impact was also determined. The chemotherapy regimens used were heterogeneous over time but principally the same at any given point in time. The majority of the patients were treated with combinations including an anthracycline and cytarabine with curative intent. Gender, morphology, and BMT did not significantly modify the effect of cytogenetic patterns on survival time, whereas age and time period did. The hazard ratios for the subgroups favorable, intermediate, and poor were 1.0, 1.2 and 1.9 at age 20-49; 1.0, 2.5 and 4.5 at age 50-64; 1.0, 4.1 and 11.4 at age 65-74; 1.0, 1.4 and 2.2 for the time period 1976-1987 and 1.0, 2.0 and 6.7 for 1988-1993. The salient feature of the Kaplan-Meier curves was the improved survival during the later time period for patients with favorable and intermediate cytogenetic abnormalities. The present findings thus suggest that it is mainly these patient groups that have benefited from advances in therapy, including supportive care.

Variation in the Ovine Abomasal Lymph Node Transcriptome between Breeds Known to Differ in Resistance to the Gastrointestinal Nematode.

Texel lambs are known to be more resistant to gastrointestinal nematode (GIN) infection than Suffolk lambs, with a greater ability to limit infection. The objectives of this study were to: 1) profile the whole transcriptome of abomasal lymph node tissue of GIN-free Texel and Suffolk lambs; 2) identify differentially expressed genes and characterize the immune-related biological pathways and networks associated with these genes. Abomasal lymph nodes were collected from Texel (n = 6) and Suffolk (n = 4) lambs aged 19 weeks that had been GIN-free since 6 weeks of age. Whole transcriptome profiling was performed using RNA-seq on the Illumina platform. At the time of conducting this study, a well annotated Ovine genome was not available and hence the sequence reads were aligned with the Bovine (UMD3.1) genome. Identification of differentially expressed genes was followed by pathway and network analysis. The Suffolk breed accounted for significantly more of the differentially expressed genes, (276 more highly expressed in Suffolk v 162 in Texel; P < 0.001). The four most significant differentially expressed pathways were all related to immunity and were classified as: Role of Pattern Recognition Receptors in Recognition of Bacteria and Viruses, Activation of IRF by Cytosolic Pattern Recognition Receptors, Role of RIG-I-like Receptors in Antiviral Innate Immunity, and Interferon Signaling. Of significance is the fact that all of these four pathways were more highly expressed in the Suffolk. These data suggest that in a GIN-free environment, Suffolk lambs have a more active immune profile relative to the Texel: this immune profile may contribute to the poorer efficiency of response to a GIN challenge in the Suffolk breed compared to the Texel breed.

Asbestos and cancer: An overview of current trends in Europe.

This review assesses the contribution of occupational asbestos exposure to the occurrence of mesothelioma and lung cancer in Europe. Available information on national asbestos consumption, proportions of the population exposed, and exposure levels is summarized. Population-based studies from various European regions on occupational asbestos exposure, mesothelioma, and lung cancer are reviewed. Asbestos consumption in 1994 ranged, per capita, between 0. 004 kg in northern Europe and 2.4 kg in the former Soviet Union. Population surveys from northern Europe indicate that 15 to 30% of the male (and a few percent of the female) population has ever had occupational exposure to asbestos, mainly in construction (75% in Finland) or in shipyards. Studies on mesothelioma combining occupational history with biologic exposure indices indicate occupational asbestos exposure in 62 to 85% of the cases. Population attributable risks for lung cancer among males range between 2 and 50% for definite asbestos exposure. After exclusion of the most extreme values because of methodologic aspects, most of the remaining estimates are within the range of 10 to 20%. Estimates of women are lower. Extrapolation of the results to national figures would decrease the estimates. Norwegian estimates indicate that one-third of expected asbestos-related lung cancers might be avoided if former asbestos workers quit smoking. The combination of a current high asbestos consumption per capita, high exposure levels, and high underlying lung cancer rates in Central Europe and the former Soviet Union suggests that the lung cancers will arise from the smoking-asbestos interaction should be a major concern.

Smoking and acute myeloid leukemia: associations with morphology and karyotypic patterns and evaluation of dose-response relations.

This case-control study of tobacco smoking and acute myeloid leukemia (AML), emphasizing specific associations with morphologic and cytogenetic subtypes, comprised smoking histories for 333 cases and 351 controls. Smoking status (ever smokers versus life-long non-smokers) showed no evident effect on AML risk. However, an effect of smoking was indicated at high cumulative smoking doses (pack-years), e.g. 40 pack-years was associated with an odds ratio (OR) of 1.5 [95% confidence interval (CI) 1.0-2.3]. Among morphologic subtypes, the smoking associated OR for acute erythroleukemia was 8.9 (95% CI 1.0-76). No clear associations between smoking and cytogenetic subtypes of AML were observed.

Hyporesponsiveness of human alveolar leukocytes to interferon-alpha and interferon-gamma inducers.

Leukocytes were obtained from bronchoalveolar lavages (BAL) of 36 patients including 10 with lung cancer, 15 with inflammatory lung diseases and 11 healthy control patients undergoing diagnostic investigation. The entire alveolar cell population responded weakly to the classic interferon (IFN) inducers: Newcastle disease virus (NDV), phytohemagglutinin (PHA) and lipopolysaccharide (LPS). This refers mainly to normal healthy volunteers. Alveolar leukocytes from patients with inflammatory lung diseases and nonsteroid treated lung cancer responded better to the interferon inducers than did cells from other patients. The IFN-alpha or IFN-gamma response of whole blood leukocytes to the same inducers was 10 to 100-fold higher than that of the alveolar cells. Alveolar macrophages from 6 healthy individuals and 3 patients with inflammatory lung disease were cultured in vitro for 6 days. The IFN response to inducers appears to depend on the origin of the cultured cells. It increased in the initially hyporeactive macrophages from healthy subjects and decreased in the relatively reactive cells from the patients with inflammatory lung diseases. We suggest that the hyporeactivity to IFN induction is a physiological state of the alveolar leukocytes which are a specialized cell population having constant exposure to inhaled agents such as dust, smoke, microorganisms and their by-products. The hyporesponsiveness to IFN induction of the alveolar cells may have an important physiological role in protecting lungs against hyperproduction of cytokines involved in the inflammatory and allergic reactions.

Measurement of lung density by x-ray computed tomography. Relation to lung mechanics in workers exposed to asbestos cement.

We measured lung density by means of x-ray computed tomography and lung mechanics in 33 workers exposed to asbestos cement and in 39 normal subjects. The exposed group showed evidence of lung fibrosis with reduced static lung volumes and lung compliance, although only three subjects had signs of interstitial fibrosis at standard chest radiography. Lung density was significantly increased in the exposed workers compared to control subjects, with greater differences between nonsmokers than between smokers. Lung density correlated inversely with static lung volumes. There was no appreciable difference in the regional distribution of lung density between exposed workers and control subjects. We conclude that lung density is often increased in workers with mild asbestosis, even in the presence of a normal chest radiograph. Measurement of lung density may be of value in the evaluation of asbestos-exposed workers for assessment of the extent of parenchymal disease.

Immunohistochemical study of 158 lung carcinomas.

Lung carcinomas were studied immunohistochemically and the results were related to type of tissue sample (bronchoscopic biopsies, surgical specimens, autopsies). All cytokeratins (CAM 5.2, PKK-1, AE1/AE3) reacted with virtually all adenocarcinomas, most squamous, and 65% of the large cell carcinomas, while CAM 5.2 was most efficient with the small cell carcinomas. CEA stained 33% and 60% of the small and large cell carcinomas, respectively, most adenocarcinomas, and 84% of the squamous cell carcinomas, among which staining decreased with dedifferentiation and was often focal. EMA reacted with 90%, and NSE with 20% of all histological types. There was no staining for NF. All antibodies, except EMA, were more efficient with surgical specimens. Our study implies that the cytokeratins we used work better with surgical material, but are generally comparable to monospecific cytokeratin antibodies. Also, EMA is a reliable marker for epithelial differentiation with all types of tissue samples. Moreover, CEA negativity in several poorly differentiated lung carcinomas might have implications in the differential diagnosis against pleural mesothelioma.

Choline and halogen derivatives of CMA (9-oxo-10-acridine acetic acids) as tools for monitoring the interaction of the interferon inducers via a specific receptor.

New choline and halogen derivatives of CMA (9-oxo-10-acridine acetic acid) were investigated as interferon (IFN) inducers in mice and in the mouse bone marrow-derived macrophage cultures. Two of the choline derivatives, DMCMA and CSCMA, were active IFN inducers presumably because they were hydrolyzed so as to release CMA. The halogen analogues of CMA were inactive or weak IFN inducers in vivo and in vitro. On the contrary, the Br and I derivatives of CMA were potent inhibitors of IFN induction by CMA in vitro. The behavior of the agonists and antagonists of CMA suggests that the induction of interferon may occur indirectly via a specific CMA-receptor complex.

Continuous intragastric pH measurement in the critically ill and treatment with parenteral ranitidine.

Continuous measurement of gastric pH using a flexible pH electrode attached to a NG tube was performed in nineteen critically ill patients. The gastric pH readings correlated well with hourly intermittent pH values using indicator strips. Hypotension, physiotherapy and septicaemia was consistently associated with falls in gastric pH. A continuous infusion of Ranitidine, a H2-receptor antagonist, was titrated against the continuously measured gastric pH in an attempt to keep it above a pH of 4. This was successfully achieved in sixteen of the nineteen patients using widely variable doses of Ranitidine. The three patients whose gastric pH remained low all had severe septicaemia.

Spontaneous migration of a central venous catheter and its repositioning: technical note.

A right atrial catheter was inserted the night before operation and its position was verified by an X-ray film. Before the performance of the surgical procedure, the catheter was attached to a strain gauge transducer and a wave form indicated catheter migration into the right ventricle. The catheter was withdrawn until atrial pulse contour developed. Verification of catheter position using this pressure pulse contour technique is simple and accurate and avoids the potential hazards of ventricular placement and the inability to aspirate adequately in the event of venous air embolism.

Intracranial pressure measurement from the anterior fontanelle utilizing a pneumoelectronic switch.

A newly developed infant cranial model shows that accurate, reproducible, and noninvasive measurements of intracranial pressure (ICP) can be made from the anterior fontanelle when fontanelle pressure is referenced from the bony margins adjacent to the fontanelle opening. Also, this model provides insight into the elastic properties of the fontanelle membrane and the pressure/volume relationships governing ICP transmission through the fontanelle window. An anterior fontanelle pressure monitor design based on data from the infant cranial model was used to monitor anterior fontanelle pressure in three infants with elevated ICP and previously inserted ventricular catheters. Measured anterior fontanelle pressure was highly correlated to ICP (r = 0.962) with high reproducibility after blind application and reapplication. Base line adjustment and in situ recalibration were easily achieved, with the monitor showing no sensitivity to patient movement and excellent frequency response.

Analysis and comparison of venous air embolism detection methods.

Changes in precordial ultrasonic Doppler patterns in dogs were compared with changes of end-tidal carbon dioxide (EtCO2) and pulmonary arterial pressure (PAP). Possible mechanisms of pulmonary arterial hypertension after air embolism in dogs are discussed. After the injection of air, an immediate change in the Doppler ultrasonic pattern was detected, including a shift of the base line. The duration of change of Doppler patterns varied depending upon the length of time that trapped air remained in the right heart. There was a delay of 15 to 30 seconds before the EtCO2 and PAP responded. In a group of dogs pretreated with 0.3 mg of propranolol per kg, there was a significant decrease in the PAP response due to induced air embolism compared to the control group (P < 0.05). We found that the Doppler ultrasonic device was the most sensitive for detecting venous air embolism at a level as low as 0.05 ml of air per kg compared to 0.25 ml/kg for the PAP and EtCO2 responses.

Clinical considerations concerning detection of venous air embolism.

Venous air embolism during neurosurgical procedures (detected by Doppler Ultrasound and aspiration via a right atrial catheter) was noted in 100 of 400 patients in the sitting position, 5 of 60 patients in the lateral position, 7 of 48 patients in the supine position, and 1 of 10 individuals monitored in the prone position. We confirmed venous air embolism in many of these cases by using serial technetium-macroaggregated albumin lung scans. Gravitational gradients from the venous portal of entrance to the right side of the heart were as small as 5.0 cm, with aspiration of 200 ml of air occurring. Doppler ultrasonic air bubble detection and aspiration through a previously inserted right atrial catheter are critical factors in the diagnosis and treatment of this condition.

Air embolism during trans-sphenoidal pituitary operations.

Doppler ultrasonic cardiac monitoring of patients undergoing trans-sphenoidal pituitary operations in the semisitting position has revealed the occurrence of venous air embolism in 3 of 31 consecutive cases. One such case is presented. Air may be drawn into the venous system whenever a gradient exists between the site of operation and the right heart. During trans-sphenoidal operations the most likely portals of venous air entry include the intercavernous connections within the sella, venous channels through nonpneumatized bone, inadequately sealed subnasal vessels, and vascularized metastatic tissue in the pituitary. Because the potential for morbidity and mortality from air embolism is so great, rapid diagnosis with the Doppler unit and prompt treatment, including aspiration of air from the right atrial catheter, administration of 100% oxygen, performance of the Valsalva maneuver, saline irrigation of the wound, and hemostasis of open vessels, are essential. Technetium-macroaggregated albumin (TEMAA) lung scans are helpful in postoperative verification of venous air embolism.

Microsurgical treatment of neurovascular disease. Part I. Personnel, equipment, extracranial-intracranial anastomosis.

This study was prepared with the objective of directing the attention of the medical community to advances during the last decade in the operative treatment of cerebral ischemia, intracranial aneurysms, and cerebral and spinal vascular malformations. The requirements for specialized personnel, facilities, and instrumentation are detailed for those who are unfamiliar with the complexities of microneurosurgery. The importance of adequate training in the intricacies of extracranial-intracranial anastomotic procedures is stressed. Reported results of this operation are discussed. It is anticipated that a recently organized cooperative study will provide the data necessary for evaluation of long term benefits. Attention is given to grading the clinical status of patients with intracranial aneurysms in advance of surgery and the importance of operating upon good risk patients. How to manage the relatively large numbers of poor risk patients with aneurysms unsuitable for immediate operation is discussed. Sophisticated radiological procedures utilized in the diagnosis, management, and evaluation of therapy are described. The role and significance of properly administered anesthesia are discussed in relation to the performance of complicated and time-consuming microsurgery on the brain and spinal cord. The study group has tried to present this material objectively and to urge those individuals working in this difficult field to acquire the special skills and instrumentation of microneurosurgery, to implement the "team-of-experts" concept in the operating room, and to enlist the support of related disciplines.

Subdural tension pneumocephalus. Report of two cases.

Two patients developed subdural tension pneumocephalus after undergoing posterior fossa surgery performed in the sitting position. The mechanism for entry of air into the intracranial compartment is analogous to the entry of air into an inverted soda-pop bottle. As the fluid pours out, air bubbles to the top of the container. We have thus referred to this as the "inverted pop-bottle syndrome." Computerized tomography provided prompt diagnosis and confirmed brain displacement. Twist-drill aspiration of the air resulted in improvement in both patients, although one patient subsequently died from an intracerebellar hemorrhage. Tension pneumocephalus appears to be another potential complication of posterior fossa surgery in the sitting position. This condition is easily diagnosed and treated, and should be considered whenever a patient fails to recover as expected following posterior fossa surgery.

Clinical evaluation of intravenous nitroglycerin for neurosurgery.

Moment-to-moment control of blood pressure is important in the management of the neurosurgical patient. The ideal agent to control blood pressure or induce hypotension should be non-toxic, maintain cerebrovascular autoregulation, and not alter cardiac output or change intracranial pressure. Intravenous nitroglycerin has been used to control blood pressure in 54 neurosurgical cases. This agent produces a rapid, controllable, but not precipitous fall in blood pressure without rebound, is non-toxic, may not alter cerebrovascular autoregulation, and does not raise intracranial pressure. Our clinical experience with intravenous nitroglycerin indicates that it has an important role as a hypotensive agent for the neurosurgical patient.