First Dark Matter Search with Nuclear Recoils from the XENONnT Experiment

We report on the first search for nuclear recoils from dark matter in the form of weakly interacting massive particles (WIMPs) with the XENONnT experiment, which is based on a two-phase time projection chamber with a sensitive liquid xenon mass of 5.9 ton. During the (1.09±0.03)  ton yr exposure used for this search, the intrinsic ^{85}Kr and ^{222}Rn concentrations in the liquid target are reduced to unprecedentedly low levels, giving an electronic recoil background rate of (15.8±1.3)  events/ton yr keV in the region of interest. A blind analysis of nuclear recoil events with energies between 3.3 and 60.5 keV finds no significant excess. This leads to a minimum upper limit on the spin-independent WIMP-nucleon cross section of 2.58×10^{-47}  cm^{2} for a WIMP mass of 28  GeV/c^{2} at 90% confidence level. Limits for spin-dependent interactions are also provided. Both the limit and the sensitivity for the full range of WIMP masses analyzed here improve on previous results obtained with the XENON1T experiment for the same exposure.

Searching for Heavy Dark Matter near the Planck Mass with XENON1T

Multiple viable theoretical models predict heavy dark matter particles with a mass close to the Planck mass, a range relatively unexplored by current experimental measurements. We use 219.4 days of data collected with the XENON1T experiment to conduct a blind search for signals from multiply interacting massive particles (MIMPs). Their unique track signature allows a targeted analysis with only 0.05 expected background events from muons. Following unblinding, we observe no signal candidate events. This Letter places strong constraints on spin-independent interactions of dark matter particles with a mass between 1×10^{12} and 2×10^{17}  GeV/c^{2}. In addition, we present the first exclusion limits on spin-dependent MIMP-neutron and MIMP-proton cross sections for dark matter particles with masses close to the Planck scale.

Search for New Physics in Electronic Recoil Data from XENONnT

We report on a blinded analysis of low-energy electronic recoil data from the first science run of the XENONnT dark matter experiment. Novel subsystems and the increased 5.9 ton liquid xenon target reduced the background in the (1, 30) keV search region to (15.8±1.3)  events/(ton×year×keV), the lowest ever achieved in a dark matter detector and ∼5 times lower than in XENON1T. With an exposure of 1.16 ton-years, we observe no excess above background and set stringent new limits on solar axions, an enhanced neutrino magnetic moment, and bosonic dark matter.

Feasibility of group cognitive behavioural therapy for insomnia (CBT-I) in bipolar disorder

Introduction

Euthymic patients with bipolar I and II disorder (BD) often have comorbid insomnia, which is associated with worse outcome. Cognitive behavioral therapy for insomnia (CBT-I) is rarely offered to this population, though preliminary research indicates CBT-I to be safe and helpful to improve sleep and mood stability.

Objectives

The present study investigates if CBT-I for euthymic BD patients is feasible and acceptable when offered in a group format.

Methods

14 euthymic bipolar disorder I or II participants participated in a 7-session group CBT-I with BD-specific modifications (CBT-I-BD), preceded by one individual session. Feasibility and acceptability were assessed by recruitment, treatment drop-out and participants’ and therapists’ evaluations, while sleep quality, mood and sleep medication were assessed at baseline, end of treatment, 3 and 6 months later.

Results

31 of 539 patients with bipolar disorder were referred, 14 were included and one dropped out of treatment. Group CBT-I-BD was acceptable as shown by high session attendance and good homework compliance. Participants highly appreciated the treatment, the group format and learning effect. Insomnia severity decreased significantly between baseline and post-treatment. Group CBT-I-BD did not cause mood episodes during treatment and although not requested, the total number of nights with sleep medication decreased.

Conclusions

Group CBT-I-BD seems to be a feasible, acceptable and therefore viable treatment for euthymic patients with bipolar disorder suffering from persistent insomnia. The small sample size, resulting in small CBT-I-BD groups was a main limitation of the study.

Remote TELEmonitoring and Health Coaching for patients with acute heart failure: results of the TELE-HC randomized trial

Introduction

Patients discharged after acute decompensated heart failure (ADHF) have elevated risk for readmission due to multiple factors including suboptimal behavioral and social support. Telemonitoring interventions have shown inconsistent effectiveness in reducing HF readmissions. Patient-centered health coaching, when combined with telemonitoring, may be a viable model to engage patients in self-care behaviors and enhance patient experiences following acute hospitalization.

Purpose

This multicenter randomized trial evaluates whether remote telemonitoring combined with health coaching decreases 60 day readmission rates for patients with ADHF when compared to standard of care.

Methods

Patients with primary or secondary diagnosis of ADHF were consented and randomized prior to hospital discharge to either standard care or intervention of remote telemonitoring and health coaching. Within 2 days of hospital dismissal, intervention patients were onboarded to the remote monitoring platform, which links personal health sensors which collect on-body physiologic measures (ECG, heart rate, respiration rate, and activity via 3-axis accelerometer) with providers through secure mobile communication. A registered nurse was designated as the primary health coach focusing on disease management - including symptom recognition, adherence to treatment strategies, care coordination, medication matters, and problem solving. A social worker and nutritionist were also assigned. The primary outcome was all-cause mortality or readmission within 60 days of hospital dismissal. Statistical analysis included stratified log-rank tests and stratified Cochran-Mantel-Haenszel Chi-square test to account for site-stratified randomization.

Results

The study was halted due to low rate of subject accrual. Of planned 304 subjects, 143 were randomized between 2015 and 2019 at 6 sites in the United States. Dropout and withdrawal after randomization of 32 subjects (22%) left 112 analyzable for the primary endpoint. Many subject withdrawals after unblinded disclosure of arm allocation were related to treatment assignment. Immediate withdrawal without follow up in these subjects precluded an intention-to-treat analysis. Mean age was 69 years and subjects were more often male (56%) and non-Hispanic white (70%). In per-protocol analysis, using subjects adherent to protocol specified visits (n=112), we observe no difference in the primary outcome (26% among intervention vs 28% among standard care, Figure, p=0.77). There were also no differences among secondary outcomes of overall mortality (2% vs 7%, p=0.20) or composite emergency department visit, hospital admission, or death (35% vs 34%, p=0.85).

Conclusions

Among patients with heart failure, an intervention of remote telemonitoring and health coaching did not reduce all-cause readmission or mortality. Significant withdrawal rates suggest future studies may need to improve screening and study retention.

Figure 1

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): National Institutes of Health, National Institute on Aging

Biological monitoring of workers exposed to engineered nanomaterials

As the number of nanomaterial workers increase there is need to consider whether biomonitoring of exposure should be used as a routine risk management tool. Currently, no biomonitoring of nanomaterials is mandated by authoritative or regulatory agencies. However, there is a growing knowledge base to support such biomonitoring, but further research is needed as are investigations of priorities for biomonitoring. That research should be focused on validation of biomarkers of exposure and effect. Some biomarkers of effect are generally nonspecific. These biomarkers need further interpretation before they should be used. Overall biomonitoring of nanomaterial workers may be important to supplement risk assessment and risk management efforts.

The treatment of premenstrual syndrome with preparations of Vitex Agnus Castus (Chaste-berry): A systematic review and meta-analysis

Introduction

Five to 8% of women of reproductive age suffer from moderate to severe symptoms of premenstrual syndrome associated with substantial distress or functional impairment.

Objective

To determine the efficacy, tolerability and acceptability of Vitex agnus castus (VAC, chaste-berry) preparations for treatment of premenstrual syndrome (PMS).

Methods

After an extensive literature search all randomized controlled trials of VAC in women with PMS and/or premenstrual dysphoric disorder were included.

Results

We found 17 randomized controlled trials of VAC in the treatment of PMS of which 14 studies could be included in the quantitative analysis. All trials, except one, found the Vitex agnus castus preparation to be more efficacious than placebo, pyridoxine and magnesium for either total symptom score or individual symptoms or symptom clusters. Unfortunately, the majority of trials is hampered by a high risk of bias. The pooled effect of VAC in placebo-controlled trials was large (Hedge's g: −1.21; 95% CI: −1.53 to −0.88), but heterogeneity extremely high (I2 = 91%). We could not single out distinct factors that could explain this heterogeneity. The funnel plot and Egger's tests suggest the presence of bias over the full set of studies and effect sizes.

Conclusion

Although meta-analysis shows a large pooled effect of VAC in placebo-controlled trials the high risk of bias, high heterogeneity and risk of publication bias of the included studies preclude a definitive conclusion. The pooled treatment effects should be viewed as merely explorative and, at best, overestimating the real treatment effect of VAC for PMS symptomatology.

Disclosure of interest

P.S. reports personal fees from H. Lundbeck A/S, outside the submitted work. The other authors have not supplied their declaration of competing interest.

Adjunctive memantine in clozapine-treated refractory schizophrenia: A one-year extension study

Introduction

In a recent 26-week placebo-controlled, crossover trial (n = 52) we found significant positive effects on verbal and visual memory, and negative symptoms in clozapine-treated patients with refractory schizophrenia.

Objectives

In this 1-year extension study, we report the long-term effects and tolerability of memantine add-on therapy to clozapine.

Aims

To evaluate the persistence of improvements in cognitive functioning and symptoms of memantine add-on therapy to clozapine in schizophrenia.

Methods

Completers of the first trial who experienced a beneficial effect of memantine after 12 weeks continued memantine for one year. Primary endpoints were change from baseline to 26 weeks treatment and 26 weeks to 52 weeks treatment on memory and executive function using the Cambridge Neuropsychological Test Automated Battery (CANTAB), Positive and Negative Syndrome Scale (PANSS), and Clinical Global Impression Severity Scale (CGI-S). Secondary endpoints were change on the Health of the Nation Outcome Scales (HoNOS) and Liverpool University Neuroleptic Side Effect Rating Scale (LUNSERS).

Results

Of 32 completers who experienced a beneficial effect of memantine 23 patients continued memantine for one year. Memory improvement was sustained, verbal recognition memory improved even further between t = 26 weeks and t = 52 weeks. Continued treatment with memantine add-on to clozapine was associated with significantly improved PANSS positive, negative and overall score, CGI-S and HoNOS scores.

Conclusions

In the extension phase the positive effect of memantine add-on therapy on verbal memory sustained and positive, negative and overall symptoms of schizophrenia, clinical global status and psychosocial functioning significantly improved. Memantine was well tolerated without serious adverse effects.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Mechanisms of pulmonary toxicity and medical applications of carbon nanotubes: Two faces of Janus?

Nanotechnology is an emerging science involving manipulation of materials at the nanometer scale. There are several exciting prospects for the application of engineered nanomaterials in medicine. However, concerns over adverse and unanticipated effects on human health have also been raised. In fact, the same properties that make engineered nanomaterials attractive from a technological and biomedical perspective could also make these novel materials harmful to human health and the environment. Carbon nanotubes are cylinders of one or several coaxial graphite layer(s) with a diameter in the order of nanometers, and serve as an instructive example of the Janus-like properties of nanomaterials. Numerous in vitro and in vivo studies have shown that carbon nanotubes and/or associated contaminants or catalytic materials that arise during the production process may induce oxidative stress and prominent pulmonary inflammation. Recent studies also suggest some similarities between the pathogenic properties of multi-walled carbon nanotubes and those of asbestos fibers. On the other hand, carbon nanotubes can be readily functionalized and several studies on the use of carbon nanotubes as versatile excipients for drug delivery and imaging of disease processes have been reported, suggesting that carbon nanotubes may have a place in the armamentarium for treatment and monitoring of cancer, infection, and other disease conditions. Nanomedicine is an emerging field that holds great promise; however, close attention to safety issues is required to ensure that the opportunities that carbon nanotubes and other engineered nanoparticles offer can be translated into feasible and safe constructs for the treatment of human disease.

Identifying high-risk small business industries for occupational safety and health interventions

BACKGROUND

Approximately one-third (32%) of U.S. workers are employed in small business industries (those with 80% of workers in establishments with fewer than 100 employees), and approximately 53 million persons in private industry work in small business establishments. This study was performed to identify small business industries at high risk for occupational injuries, illnesses, and fatalities.

METHODS

Small business industries were identified from among all three- and four-digit Standard Industrial Classification (SIC) codes and ranked using Bureau of Labor Statistics (BLS) data by rates and numbers of occupational injuries, illnesses, and fatalities. Both incidence rates and number of injury, illness, and fatality cases were evaluated.

RESULTS

The 253 small business industries identified accounted for 1,568 work-related fatalities (34% of all private industry). Transportation incidents and violent acts were the leading causes of these fatalities. Detailed injury and illness data were available for 105 small business industries, that accounted for 1,476,400 work-related injuries, and 55,850 occupational illnesses. Many of the small business industries had morbidity and mortality rates exceeding the average rates for all private industry. The highest risk small business industries, based on a combined morbidity and mortality index, included logging, cut stone and stone products, truck terminals, and roofing, siding, and sheet metal work.

CONCLUSIONS

Identification of high-risk small business industries indicates priorities for those interested in developing targeted prevention programs.

Serum organochlorine levels and breast cancer: a nested case-control study of Norwegian women

This study investigated the potential association between organochlorine exposure and breast cancer using stored sera collected from 1973 through 1991 from the Janus Serum Bank in Norway. Breast cancer cases were ascertained prospectively from among 25,431 female serum bank donors. A total of 150 controls were matched to cases by birth dates and dates of sample collection. One g of serum per subject was analyzed for a total of 71 organochlorine compounds. For 6 pesticides [B-hexachlorocyclohexane, heptachlor epoxide, oxychlordane, trans-nonachlor, p, p'-1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene, and p, p'-2,2-bis(p-chlorophenyl)-1,1,1-trichloroethane] and 26 individual polychlorinated biphenyl (PCB) congeners there were >90% of samples over the limit of detection. There was no evidence for higher mean serum levels among cases for any of these compounds, nor any trend of increasing risk associated with higher quartiles of exposure. The remaining compounds (including dieldrin) were analyzed with respect to the proportion of cancer cases and controls having detectable levels; no positive associations were noted in these analyses. Our study did not confirm the recent findings of a Danish study of increased concentrations of dieldrin in the serum of breast cancer cases. The evidence to date on the association between serum organochlorines is not entirely consistent, but there is accumulating evidence that serum levels of p, p'-1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene and total PCBs are not important predictors for breast cancer in the general population. Studies to date have not been able to evaluate whether exposure to highly estrogenic, short-lived PCB congeners increases breast cancer risk, nor have they fully evaluated the risk associated with organochlorine exposure in susceptible subgroups or at levels above general population exposure, including women with occupational exposure.

Stimulation of phosphatidylinositol-4-phosphate 5-kinase by Rho-kinase

The serine/threonine kinase Rho-kinase was recently identified as a downstream effector of the small GTPase Rho, mediating effects of Rho on the actin cytoskeleton. Also phosphatidylinositol 4,5-bisphosphate (PI(4,5)P(2)) has been implicated in the regulation of actin polymerization. As the synthesis of PI(4,5)P(2) has been suggested to be affected by Rho proteins, we investigated whether Rho-kinase is involved in the control of PI(4,5)P(2) levels. Overexpression of RhoA in HEK-293 cells increased phosphatidylinositol 4-phosphate (PI4P) 5-kinase activity and concomitantly enhanced cellular PI(4,5)P(2) levels, whereas overexpression of the Rho-inactivating C3 transferase decreased both PI4P 5-kinase activity and PI(4,5)P(2) levels. These effects of RhoA could be mimicked by overexpression of wild-type Rho-kinase and of the constitutively active catalytic domain of Rho-kinase, Rho-kinase-CAT. In contrast, a kinase-deficient mutant of Rho-kinase had no effect on PI4P 5-kinase activity. Importantly, the increase in PI4P 5-kinase activity and PI(4,5)P(2) levels by wild-type Rho-kinase, but not by Rho-kinase-CAT, was completely prevented by coexpression of C3 transferase, indicating that the effect of Rho-kinase was under the control of endogenous Rho. In cell lysates, addition of recombinant RhoA and Rho-kinase-CAT stimulated PI4P 5-kinase activity. Finally, the increase in PI(4,5)P(2) levels induced by both Rho-kinase-CAT and RhoA was reversed by the Rho-kinase inhibitor HA-1077. Our data suggest that Rho-kinase is involved in the Rho-controlled synthesis of PI(4,5)P(2) by PI4P 5-kinase.

NMR solution structure of a complex of calmodulin with a binding peptide of the Ca2+ pump

The three-dimensional structure of the complex between calmodulin (CaM) and a peptide corresponding to the N-terminal portion of the CaM-binding domain of the plasma membrane calcium pump, the peptide C20W, has been solved by heteronuclear three-dimensional nuclear magnetic resonance (NMR) spectroscopy. The structure calculation is based on a total of 1808 intramolecular NOEs and 49 intermolecular NOEs between the peptide C20W and calmodulin from heteronuclear-filtered NOESY spectra and a half-filtered experiment, respectively. Chemical shift differences between free Ca(2+)-saturated CaM and its complex with C20W as well as the structure calculation reveal that C20W binds solely to the C-terminal half of CaM. In addition, comparison of the methyl resonances of the nine assigned methionine residues of free Ca(2+)-saturated CaM with those of the CaM/C20W complex revealed a significant difference between the N-terminal and the C-terminal domain; i.e., resonances in the N-terminal domain of the complex were much more similar to those reported for free CaM in contrast to those in the C-terminal half which were significantly different not only from the resonances of free CaM but also from those reported for the CaM/M13 complex. As a consequence, the global structure of the CaM/C20W complex is unusual, i.e., different from other peptide calmodulin complexes, since we find no indication for a collapsed structure. The fine modulation in the peptide protein interface shows a number of differences to the CaM/M13 complex studied by Ikura et al. [Ikura, M., Clore, G. M., Gronenborn, A. M., Zhu, G., Klee, C. B., and Bax, A. (1992) Science 256, 632-638]. The unusual binding mode to only the C-terminal half of CaM is in agreement with the biochemical observation that the calcium pump can be activated by the C-terminal half of CaM alone [Guerini, D., Krebs, J., and Carafoli, E. (1984) J. Biol. Chem. 259, 15172-15177].

Roles of epidemiology, pathology, molecular biology, and biomarkers in the investigation of occupational lung cancer

The pathology and molecular biology of lung cancer demonstrate that these tumors evolve through a series of mutations, molecular changes, and corresponding morphologic changes. To elucidate how occupational and environmental factors influence lung cancer histogenesis it is important not only to understand epidemiology and the interactions between etiologic agents but also to integrate information from pathology, biochemistry and molecular biology. This review focuses on the range of techniques currently available for characterizing lung cancer and how their prudent use can be beneficial in the identification of occupational carcinogens. Because many occupational and environmental lung cancers are caused by multiple etiologic agents, the integration of histology with cellular, biochemical and molecular biomarker techniques may provide new approaches for understanding the disease process.

Incidence of tuberculosis infection among New York State prison employees

OBJECTIVES

This study examined tuberculosis skin test conversions among 24,487 New York State prison employees in 1992.

METHODS

Conversions were analyzed by prison and by job category.

RESULTS

The conversion rate was 1.9%. Employees in prisons with low and high numbers of prisoner cases had odds ratios for conversion of 1.67 (95% confidence interval [CI] = 1.27, 2.19) and 2.20 (95% CI = 1.69, 2.87), respectively, relative to employees in prisons with no prisoner cases. In prisons with cases, guards and medical personnel had odds ratios of 1.64 (95% CI = 1.11, 2.43) and 2.39 (95% CI = 1.40, 4.08), respectively, relative to employees with little prisoner contact.

CONCLUSIONS

In 1992, approximately one third of new infections among New York State prison employees were due to occupational exposure.

Treatment with growth factors in myelodysplastic syndromes

In myelodysplastic syndromes (MDS), pancytopenia leads to a high risk of infectious and hemorrhagic complications. The progression to acute myeloid leukemia adds to morbidity and mortality. While transfusions of red blood cells and platelets are still a cornerstone of the therapy, the clinical use of recombinant hematopoietic growth factors has enlarged the range of therapeutic applications in patients with MDS. It is possible to reverse neutropenia by administration of G-CSF (granulocyte colony stimulating factor) or GM-CSF (granulocyte-monocyte colony stimulating factor). In the case of a severe infection, therapeutic administration of G-CSF together with antibiotics might be justified in otherwise neutropenic MDS patients. Since especially patients with only slight impairment of erythropoiesis and no transfusion dependency have the highest response rates but need erythropoietin (EPO) the least, pharmacoeconomic analyses are urgently needed. Controlled randomized trials will have to ascertain wether combinations of EPO with G-CSF or GM-CSF are of benefit. Clinical studies with thrombopoietin (megakaryocyte growth and differentiation factor) have to be initiated to find out whether thrombocytopenia in MDS can be reversed.

Clinical use of hematopoietic growth factors in patients with myelodysplastic syndromes

In myelodysplastic syndromes (MDS), pancytopenia and defective function of neutrophils and platelets lead to a high risk of infectious and hemorrhagic complications. The progression to acute myeloid leukemia adds to morbidity and mortality. Supportive care including red blood cell and platelet transfusions are still the cornerstone of therapeutic management. However, the clinical use of the recombinant hematopoietic growth factors has enlarged the range of therapeutic applications in patients with MDS. It is possible to reverse neutropenia in MDS patients by administration of G-CSF (granulocyte colony stimulating factor) or GM-CSF (granulocyte-monocyte colony stimulating factor). Because of the lower incidence of adverse events, G-CSF is preferable. However, neither G-CSF nor GM-CSF have been shown to reduce the rate of severe infection or mortality from infection when given prophylactically. In the case of a severe infection, therapeutic administration of G-CSF together with antibiotics might be justified in otherwise neutropenic MDS patients. Preliminary data suggest it to be possible to identify MDS patients with a higher than 50% chance of reversal of anemia or transfusion dependency by treatment with high-dose erythropoietin (EPO). Since patients with only slight impairment of erythropoiesis and no transfusion dependency have the highest response rates but need EPO the least, pharmacoeconomic analyses are urgently needed. Controlled randomized trials will have to ascertain whether combinations of EPO with G-CSF or GM-CSF are of benefit. Clinical studies with thrombopoietin (megakaryocyte growth and differentiation factor) have to be initiated to find out whether thrombocytopenia in MDS can be reversed.

Fulminant liver failure in association with the emetic toxin of Bacillus cereus

BACKGROUND

A 17-year-old boy and his father had acute gastroenteritis after eating spaghetti and pesto that had been prepared four days earlier. Within two days, fulminant liver failure and rhabdomyolysis developed in the boy and he died. The father had hyperbilirubinemia and rhabdomyolysis but recovered. We investigated the cause of these illnesses.

METHODS

Bacteria were isolated and characterized by conventional methods, and bacterial toxins were quantified by immunoassays and cell-culture techniques. The effect of the isolated toxin on the rates of oxidation of various substrates was analyzed in rat-liver mitochondria.

RESULTS

Autopsy of the boy's liver revealed diffuse microvesicular steatosis and midzonal necrosis that suggested impaired beta-oxidation of liver mitochondria due to a mitochondrial toxin. There was no evidence of ingestion of heavy metals, halogenated compounds, hepatotoxic drugs, or staphylococcal enterotoxin. However, high concentrations of Bacillus cereus emetic toxin were found in both the residue from the pan used to reheat the food and the boy's liver and bile. B. cereus was cultured from the intestinal contents and the pan residue. The emetic toxin isolated from the B. cereus cultures was found to be a mitochondrial toxin.

CONCLUSIONS

Fulminant liver failure developed after the ingestion of food contaminated with the B. cereus emetic toxin. The toxin inhibits hepatic mitochondrial fatty-acid oxidation, indicating that it caused liver failure in this patient.

Assessment of reproductive disorders and birth defects in communities near hazardous chemical sites. II. Female reproductive disorders

Members of the workgroup on female reproductive disorders discussed methods to evaluate five principal functions: menstrual dysfunction, infertility, pregnancy loss, lactation disorders, and pregnancy complications. To test each function, a nested strategy was considered, based on progressive levels of effort available to conduct field investigations. This strategy was analogous to the three-tier classification of biomarkers used by other workshops. The lowest level of effort, corresponding to Tier 1, consists only of questionnaires, diaries, and reviews of maternal and infant medical records. The medium level of effort (Tier 2) collects data from questionnaires and diaries, and some biologic specimens. Suggested laboratory analyses included measurement of progesterone in saliva and several glycoprotein hormones in urine that evaluate menstrual dysfunction, infertility, and pregnancy loss. The highest level of effort (Tier 3) involves prospective collection of diary information and simultaneous collection of biological specimens.

O6-alkylguanine DNA alkyltransferase activity in student embalmers

O6-Alkylguanine-DNA alkyltransferase (AGT) activity was assessed in peripheral blood lymphocytes among 23 mortuary science students before and after 9 weeks in a laboratory course in techniques of embalming. Formaldehyde exposure was established by environmental monitoring. The average air concentration of formaldehyde during embalming was about 1.5 ppm. At the pre-exposure sampling, baseline DNA repair capacity tended to be reduced in subjects who reported a prior history of embalming (p = 0.08). From pre- to post-exposure, 17 subjects decreased in DNA repair capacity, while only 6 increased (p < 0.05). Analysis of variance, including adjustment for age, sex, and smoking status, confirmed these findings. Among the eight subjects who had no embalming experience during the 90 days before study, seven had decreased and one had increased AGT activity during the period of study (p < 0.05). For those with prior embalming experience, 10 subjects decreased in AGT activity, while 5 increased (p < 0.05). Although the major chemical exposure in embalming practice was to formaldehyde, no clear link was established between amount of formaldehyde exposure and AGT activity.

Quantification of epithelial cell micronuclei by fluorescence in situ hybridization (FISH) in mortuary science students exposed to formaldehyde

A micronucleus assay employing fluorescence in situ hybridization (FISH) with a centromeric probe was used on specimens of exfoliated buccal and nasal cells collected from mortuary science students exposed to embalming fluid containing formaldehyde. FISH labeling allowed micronuclei (MN) containing a whole chromosome (centromere-positive, MN+) to be differentiated from those containing only chromosomal fragments (centromere-negative, MN-). Each student was sampled before and after the 90 day embalming class. We determined if an increase in MN frequency could be attributed to formaldehyde exposure and was specific to either MN+ or MN-. In buccal cells, total MN frequency was significantly increased from 0.6/1000 to 2/1000 (p = 0.007) following the course, whereas in nasal cells it was not (2 and 2.5/1000, respectively, p = 0.2). Cells with multiple MN were present only in samples taken after exposure to embalming fluid. Although the baseline frequency was higher for MN+ in both buccal (0.4/1000 for MN+ and 0.1/1000 for MN-) and nasal cells (1.2/1000 for MN+ and 0.5/1000 for MN-), the increase in MN frequency was greater for MN-, (9-fold, p = 0.005 for buccal cells; 2-fold, p = 0.03 for nasal cells) than for MN+ (> 2-fold, p = 0.08 for buccal cells; no change, p = 0.31 for nasal cells) in both tissues. Thus, the primary mechanism of micronucleus formation appeared to be chromosome breakage. This finding is consistent with known clastogenic properties of formaldehyde, the component of embalming fluid most likely responsible for micronucleus induction.

[Subjective perception of social support in the population]

The ISEL scale (Interpersonal Support Evaluation List) has been developed to assess social support. Despite good reliability and validity of the original scale the German version has been rately applied. Thus, perceived social support as measured by the ISEL scale was studied in a general population sample of Tyrol/Austria (n = 216). The reliability of the German ISEL version is as high as the original version. Our results showed that sociodemographic variables significantly influence scale scores: Males and rural subjects indicated more tangible support than females and urban subjects, respectively. Elder people (50-70 years) reported the lowest scale scores, except in tangible support. With the exception of tangible support, significant socioeconomic status differences were found in all dimensions of social support. However, the middle classes showed less social support than upper and lower class subjects. Income only increased tangible support, as higher educational degrees did with self-esteem support. Marital status showed no influence on scale scores, whereas unemployment decreased tangible and belonging support. Our results can be used as preliminary German language norm data for evaluating social support in epidemiological and clinical studies.

Minimizing alcohol exposure of the breastfeeding infant

What are the effects of alcohol consumed by breastfeeding women on their nursing infants? The woman's weight, whether she is amenorrheic during lactation, and the age of her baby are important considerations that influence blood alcohol concentrations and the effect of a mother's alcohol consumption.

Proportionate mortality among construction laborers

This report presents the results of proportionate mortality ratio (PMR) analyses and proportionate cancer mortality ratio (PCMR) analyses among the 11,685 members of the Laborers' International Union of North America (LIUNA), who died between 1985-1988, using U.S. proportionate mortality rates as the comparison population. Statistically significant elevated mortality risks were observed for all malignant neoplasms (N = 3285, PMR = 1.13, CI = 1.09-1.17), as well as for site-specific neoplasms of the lung (N = 1208, PCMR = 1.06, CI = 1.00-1.12), stomach (N = 170, PCMR = 1.44, CI = 1.23-1.68), and thyroid gland (N = 10, PCMR = 2.24, CI = 1.07-4.12). The PCMRs for these malignant neoplasms were elevated among both white and non-white males, regardless of length of union membership, in most 10-year categories of age at death above 40 and for the three largest LIUNA regions examined. The study also observed 20 mesothelioma deaths, which indicated that some LIUNA members had been previously exposed to asbestos. Statistically significant elevated risks were also observed for deaths from transportation injuries (N = 448, PMR = 1.37, CI = 1.25-1.51), falls (N = 85, PMR = 1.34, CI = 1.07-1.66), and other types of injuries (N = 245, PMR = 1.61, CI = 1.42-1.83). The deaths due to injuries were most often observed among those members who had the shortest amount of time within the union, were younger, and first entered the union after 1955. This is the first study that has examined the general mortality experience limited to construction laborers only (Bureau of Census code 869).

Vasopressin induces frequency-modulated repetitive calcium transients in single insulin-secreting hit cells

Ca2+ is central to the stimulation of insulin secretion from pancreatic beta-cells. Arginine-vasopressin (AVP) may participate in the modulation of insulin release. In the present study, the AVP-induced changes in cytosolic free Ca2+ ([Ca2+]i) were investigated in single fura-2 loaded insulin-secreting HIT cells. Stimulation with AVP (0.1-5 nM) caused repetitive Ca2+ transients. The frequency but not the amplitude of the Ca2+ transients was modulated by the concentration of AVP. High concentrations of AVP (10-100 nM) triggered a biphasic rise in [Ca2+]i. In Ca(2+)-free medium AVP caused only one or two Ca2+ transients. Withdrawal of extracellular Ca2+ rapidly abolished the AVP-induced Ca2+ transients in all cells tested. The Ca2+ channel blocker, verapamil (50 microM), reduced amplitude and frequency of the Ca2+ transients by about 25% and 60%, respectively, and terminated the Ca2+ transients in 2 of 6 cells. When HIT cells were incubated in Ca(2+)-free medium, and extracellular Ca2+ was restored, there was a small increase in [Ca2+]i. If, however, the agonist-sensitive Ca2+ pool was functionally depleted by repetitive stimulation with high concentrations of AVP or thapsigargin in Ca(2+)-free medium before extracellular Ca2+ was restored, an agonist-independent increase in [Ca2+]i was observed, which was transiently larger than in the control cells, and was mainly preserved in the presence of verapamil. Thus, depletion of the agonist-sensitive Ca2+ pool enhances the influx of extracellular Ca2+ through a Ca2+ entry mechanism independent from verapamil-sensitive voltage-dependent Ca2+ channels (VDCC).(ABSTRACT TRUNCATED AT 250 WORDS)

IMPLICATIONS OF HYPERGLYCEMIA FOR POST-EXERCISE RESYNTHESIS OF GLYCOGEN IN TROUT SKELETAL MUSCLE

Rates of whole-body glucose turnover and muscle-specific glucose utilization were determined in rainbow trout (Oncorhynchus mykiss) at rest and at intervals during recovery from burst swimming. Plasma glucose level was high in the experimental animals (range 6&shy;38 mmol l-1), but hyperglycemia was not related specifically to exercise. Estimated glucose turnover, 19.3&plusmn;2.6 (rest) and 15.8&plusmn;3.9 &micro;mol min-1 kg-1 (recovery), was also highly variable, but was linearly associated with plasma glucose concentration (turnover=0.97[glucose]+0.57, r=0.93) in both resting and recovering fish. While utilization of glucose in the whole animal was clearly responsive to plasma glucose availability, estimated total skeletal muscle disposal of glucose accounted for less than 15 % of glucose turnover, indicating that glucose was utilized largely by tissues other than locomotory muscle. Rates of glucose utilization in white muscle (range 0.5&shy;4 nmol min-1 g-1) provide direct evidence that glucose, regardless of plasma concentration, accounted for less than 10 % of glycogen repletion during exercise recovery. In red muscle, glucose uptake was influenced by plasma glucose level below 10&shy;12 mmol l-1 (utilization range 1&shy;15 nmol min-1 g-1), but was independent of glucose concentration above about 12 mmol l-1 (utilization plateaued at 15&shy;20 nmol min-1 g-1). Trout red muscle is similar to mammalian white muscle in the sense that glucose is estimated to account incompletely for glycogen restoration (25&shy;60 %), suggesting dependence on both glycogenesis and glyconeogenesis during recovery. It is concluded that hyperglycemia may be important to the pattern of substrate incorporation into red muscle glycogen and to the rate of repletion observed, but glucose availability has, as predicted from earlier indirect studies, little relevance to white muscle glycogen restoration. The regulatory mechanisms that govern apparently very high glucose turnover rates during extreme hyperglycemia, concomitant with low disposal rates in skeletal muscle, require further investigation.

Cytogenetic effects of formaldehyde exposure in students of mortuary science

The effect of low-level exposure to formaldehyde on oral, nasal, and lymphoycte biological markers was studied prospectively in a group of 29 mortician students who were about to take a course in embalming. During the 85-day study period, the subjects performed an average of 6.9 embalmings and had average cumulative formaldehyde exposures of 14.8 ppm-h, with an average air concentration of 1.4 ppm during embalming. Since the average time spent embalming was 125 min, formaldehyde exposures calculated as an 8-h time-weighted average were 0.33 ppm on days when embalmings were done, which was less than the Occupational Safety and Health Administration permissible exposure limit of 0.75 ppm. Epithelial cells from the buccal area of the mouth showed a 12-fold increase in micronucleus frequency during the study period, from 0.046 +/- 0.17/1000 cells preexposure to 0.60 +/- 1.27/1000 cells at the end of the course (P < 0.05). Nasal epithelial micronuclei increased 22%, from 0.41 +/- 0.52/1000 cells to 0.50 +/- 0.67/1000 cells (P = 0.26). In blood cells, the frequency of micronucleated lymphocytes increased 28%, from 4.95 +/- 1.72/1000 cells to 6.36 +/- 2.03/1000 cells (P < 0.05), while sister chromatid exchanges decreased 7.5% (P < 0.05). A dose-response relationship was observed between cumulative exposure to formaldehyde and increases in buccal micronuclei in the 22 male subjects but not in the 7 female subjects. We conclude that low-level exposure to formaldehyde is associated with cytogenetic changes in epithelial cells of the mouth and in blood lymphocytes. These cytogenetic effects may be useful as markers of biologically effective dose.

[Compartment syndrome after femoral contusion. Case report and review of the literature]

Compartment syndromes of the lower arm and lower leg are quite well known by now and have been often described in the literature. Those of the upper arm and thigh are rarer and those after pure closed lesion of the soft parts of the thigh are the subject of only sporadic reports in the literature. A recently observed case of this kind prompted the present case report and review of the literature.