Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

Design of the high-yield time-gated x-ray hot-spot imager for OMEGA

Time-resolved x-ray self-emission imaging of hot spots in inertial confinement fusion experiments along several lines of sight provides critical information on the pressure and the transient morphology of the hot spot on the University of Rochester's OMEGA Laser System. At least three quasi-orthogonal lines of sight are required to infer the tomographic information of the hot spots of deuterium-tritium cryogenic layered implosions. OMEGA currently has two time-gated x-ray hot-spot imagers: the time-resolved Kirkpatrick-Baez x-ray microscope and the single-line-of-sight, time-resolved x-ray imager (SLOS-TRXI). The time-gated x-ray hot-spot imager (XRHSI) is being developed for use on OMEGA as the third line of sight for the high-yield operation of up to 4 × 10¹⁴ neutrons. XRHSI follows the SLOS-TRXI concept; however, it will have improved spatial and temporal resolutions of 5 μm and 20 ps, respectively. The simultaneous operation of the three instruments will provide 3-D reconstructions of the assembled hot-spot fuel at various times through peak thermonuclear output. The technical approach consists of a pinhole array imager and demagnifying time-dilation drift tube that are coupled to two side-by-side hybrid complementary metal-oxide semiconductor (hCMOS) image sensors. To minimize the background and to harden the diagnostics, an angled drift-tube assembly shifting the hCMOS sensors out of the direct line of sight and neutron shielding will be applied. The technical design space for the instrument will be discussed and the conceptual design will be presented.

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

242 Maintaining Surgical Training During the Covid-19 Pandemic; A Novel Use of Surgical Simulators

Introduction

During Covid-19 pandemic, operation theatres limit the number of staff during each session, which causes a decrease in training opportunity. To counteract this lapse, the Orthopaedic Research Institute (ORI) designs an innovative training session. During the nationwide lockdown, the closure of the Institute allowed for the transfer of the VirtaMed ArthrosTM (VA), to our NHS facility. VA is a surgical simulator which enables the participant to practise knee arthroscopy.

Method

Participants with little arthroscopic experience were included in the study. Three fellowship-trained surgeons conducted daily teaching sessions. Participants were taught necessary arthroscopic skills before undertaking training modules on diagnostic arthroscopy. 90% of the participants attended the session at least three times.

At the end of every module, VA generates a score based on parameters which include procedure duration, visualisation of key structures and iatrogenic chondral damage. Structure questionnaires were also used to analyse feedback.

Results

The overall confidence and module scores progress with each subsequent session. A keystone of success is the location and ease of access to the simulator.

Conclusions

Surgical simulators are a useful tool for surgical education and training. We should encourage their use in the future, especially in the UK surgical training programme.

SHadow Under the Lamp (SHUL): Smoking behavior of the health professionals

Background

Smoking cessation is the best option a health professional can offer to the patients for averting the preventable causes of mortality and morbidity.

Purpose

To determine smoking behavior, preferred cessation methods, and attitudes towards smoking cessation amongst health professionals.

Methods

The cross-sectional study, conducted in six countries, included doctors and nurses working at different hospital settings. Participants responded anonymously to an online questionnaire.

Results

Among 1109 participants, 36% were from Saudi Arabia, 14% from Nepal, 14% from Indonesia, 12% from Australia, 12% from Jordan, and 12% from Pakistan. Mean age was 33 years, 61% were females and 58% were nurses. One in eight (12%) was daily smoker. Among current smokers, 42% smoked 2-9 cigarettes/day, and 26% had their first cigarette within 5-30 minutes after waking up. Half of the smokers perceived it as 'very important' to quit smoking, 30% had tried to quit in the last six months, and 31% preferred to have a group quit program with the same health professionals. Only 17% had formal training on smoking cessation, but 57% were interested to receive one. Half of the participants said they (53%) 'always' asked patients if they smoked, but 89% said they advised to quit, 76% said they assessed intention to quit, 28% said they assisted by providing materials on cessation, and 33% said they arranged follow up for cessation. Compared to current smokers, never smokers were more likely to 'always' ask patients if they smoked (78% vs. 22%, p = 0.044, ORs 1.39, 95%CIs 1.01-1.91), assist smokers by setting quit dates (74% vs. 26%, p = 0.039, ORs 1.54, 95%CIs 1.03-2.29), arrange follow up (77% vs. 23%, p = 0.044, ORs 1.40, 95%CIs 1.01-1.94).

Conclusions

Health professionals reported moderately good behavior around advice to smokers, but it is much worse among current smokers. Health professionals who smoke should be both encouraged to quit and to better support their patients to do so.

Key messages

Smoking cessation support for patients was not good among health professionals, who were smokers. Health professionals need to quit smoking in order to provide better cessation support for patients.

Developments in imaging methods used in hip arthroplasty: A diagnostic algorithm

BACKGROUND

Several imaging modalities can be used to diagnose complications of hip prosthesis placement. Despite progress in these imaging techniques, there are, as yet, no guidelines as to their respective indications.

METHODS

We formed a panel of experts in fields related to prosthesis imaging (radiology, nuclear medicine, orthopedic surgery) and conducted a review of the literature to determine the value of each modality for diagnosing complications following hip replacement.

RESULTS

Few recent studies have investigated the benefits related to the use of the latest technical developments, and studies comparing different methods are extremely rare.

CONCLUSIONS

We have developed a diagnostic tree based on the characteristics of each imaging technique and recommend its use. Computed topography was found to be the most versatile and cost-effective imaging solution and therefore a key tool for diagnosing the complications of hip replacement surgery.

Subchondral linear hyperintensity of the femoral head: MR imaging findings and associations with femoro-acetabular joint pathology

PURPOSE

The goal of this study was to evaluate the associations between linear hyperintensity in the subchondral bone of the femoral head on T2-weighted MR imaging and structural bone lesions.

MATERIAL AND METHODS

The MR imaging examinations of 63 patients (66 hips) that showed a bone marrow edema pattern (BMEP) of the hip were retrospectively evaluated (study group). The study group comprised 43 men and 20 women, with a mean age of 55.3 years±16.9 (SD) (range: 19-84 years). A control group of 61 patients (77 hips) without BMEP of the hip on MR imaging was created. The control group comprised 30 men and 31 women, with a mean age of 53.1 years±15.6 (SD) (range: 25-83 years). The presence of linear abnormalities of the subchondral bone on T2-weighted fat-saturated sequences (TR/TE=4220-4340/42-45ms) was evaluated and MR imaging findings were correlated with structural femoro-acetabular pathology (advanced chondropathy, osteonecrosis, subchondral insufficiency fractures and macroscopic fractures) and with pain duration.

RESULTS

A linear hyperintensity in the subchondral bone on T2-weighted MR imaging was found in 43/66 hips with areas of BMEP (65.1%) and in 3/77 hips without BMEP (3.8%). Subchondral linear hyperintensity was seen in 15/16 (93.7%) hips with a subchondral insufficiency fracture. Among the 16 hips with an ARCO stage III osteonecrosis, 13 (76.9%) presented BMEP associated with a subchondral linear hyperintensity. BMEP was present in 6/8 hips with ARCO stage IV osteonecrosis; however, only two hips (25%) exhibited subchondral linear hyperintensities. Finally, 77.7% of patients with subchondral linear hyperintensities presented with acute or subacute hip pain (P<0.0001).

CONCLUSION

Femoral head subchondral linear hyperintensity on T2-weighted MR imaging is common and is associated with acute subchondral bone damage.

Relationship between testosterone, estradiol and circulating PCSK9: Cross-sectional and interventional studies in humans

BACKGROUND

Circulating PCSK9 levels are higher in women than men, in postmenopausal than premenopausal women, and in pregnant than non-pregnant women, suggesting that sex hormones may be related to PCSK9 levels. We have examined the relationship between serum estradiol (E2) and testosterone (T) and PCSK9, and the impact of E2 replacement therapy in women and T replacement and ablation therapy in men on circulating PCSK9.

METHODS

We conducted a cross-sectional study to examine the correlation between serum T (in males) and E2 (in females) and serum PCSK9. We also conducted interventional studies to examine the effect of hormonal therapy on serum PCSK9 levels.

RESULTS

In men, (1) serum T does not correlate with circulating PCSK9 or with LDLC in the basal state, (2) T replacement therapy does not have any effect on circulating PCSK9, and (3) T ablation therapy has mixed results. In women, (1) E2 correlates inversely with circulating PCSK9 and directly with serum LDLC, but (2) E2 replacement therapy does not have any effect on circulating PCSK9.

CONCLUSIONS

We demonstrate differences between men and women in the relationship of their major sex hormones with circulating PCSK9. In men, circulating PCSK9 is not related to or affected by T except for a possible effect during T ablation therapy. In women, E2 is inversely related to circulating PCSK9 but the lack of effect of E2 therapy on circulating PCSK9 suggests that the E2-related differences in PCSK9 levels may be the result of differences in receptor-mediated PCSK9 clearance through E2-induced changes rather than production of PCSK9. The studies were registered with ClinicalTrials.gov NCT00848276.

Strategy and optimization of diagnostic imaging in painful hip in adults

Diagnostic imaging strategy in painful hip depends on many factors, but in all cases, plain X-ray is the first investigation. It may be sufficient to reach diagnosis and determine treatment options. More effective but more expensive exploration is indicated in two circumstances: when plain X-ray is non-contributive, and when diagnosis has been established but more accurate imaging assessment is needed to guide treatment. Following radiography, the choice of imaging techniques depends not only on the suspected pathology but also on the availability of equipment and its performance. MRI is probably the technique that provides the most comprehensive results; recent improved accessibility has significantly simplified the diagnostic algorithm. CT remains invaluable, and current techniques have reduced patient irradiation to a level similar to that of standard X-ray. Finally, cost is an important consideration in choosing the means of exploration, but the overall financial impact of the various strategies for diagnosis of painful hip is not well established. This article aims to provide a simple and effective diagnostic strategy for the assessment of painful hip, taking account of the clinical situation, and to detail the most typical semiologic patterns of each disease affecting this joint.

A phase I multi-institutional study of systemic sorafenib in conjunction with regional melphalan for in-transit melanoma of the extremity

BACKGROUND

Isolated limb infusion with melphalan (ILI-M) corrected for ideal body weight (IBW) is a well-tolerated treatment for patients with in-transit extremity melanoma with an approximate 29 % complete response (CR) rate. Sorafenib, a multi-kinase inhibitor, has been shown to augment tumor response to chemotherapy in preclinical studies.

METHODS

A multi-institutional, dose-escalation, phase I study was performed to evaluate the safety and antitumor activity of sorafenib in combination with ILI-M. Patients with AJCC stage IIIB/IIIC/IV melanoma were treated with sorafenib starting at 400 mg daily for 7 days before and 7 days after ILI-M corrected for IBW. Toxicity, drug pharmacokinetics, and tumor protein expression changes were measured and correlated with clinical response at 3 months.

RESULTS

A total of 20 patients were enrolled at two institutions. The maximum tolerated dose (MTD) of sorafenib in combination with ILI-M was 400 mg. Four dose-limiting toxicities occurred, including soft tissue ulcerations and compartment syndrome. There were three CRs (15 %) and four partial responses (20 %). Of patients with the Braf mutation, 83 % (n = 6) progressed compared with only 33 % without (n = 12). Short-term sorafenib treatment did alter protein expression as measured with reverse phase protein array (RPPA) analysis, but did not inhibit protein expression in the MAP kinase pathway. Sorafenib did not alter melphalan pharmacokinetics.

CONCLUSION

This trial defined the MTD of systemically administered sorafenib in combination with ILI-M. Although some responses were seen, the addition of sorafenib to ILI-M did not appear to augment the effects of melphalan but did increase regional toxicity.

Systematic resequencing of X-chromosome synaptic genes in autism spectrum disorder and schizophrenia

Autism spectrum disorder (ASD) and schizophrenia (SCZ) are two common neurodevelopmental syndromes that result from the combined effects of environmental and genetic factors. We set out to test the hypothesis that rare variants in many different genes, including de novo variants, could predispose to these conditions in a fraction of cases. In addition, for both disorders, males are either more significantly or more severely affected than females, which may be explained in part by X-linked genetic factors. Therefore, we directly sequenced 111 X-linked synaptic genes in individuals with ASD (n = 142; 122 males and 20 females) or SCZ (n = 143; 95 males and 48 females). We identified >200 non-synonymous variants, with an excess of rare damaging variants, which suggest the presence of disease-causing mutations. Truncating mutations in genes encoding the calcium-related protein IL1RAPL1 (already described in Piton et al. Hum Mol Genet 2008) and the monoamine degradation enzyme monoamine oxidase B were found in ASD and SCZ, respectively. Moreover, several promising non-synonymous rare variants were identified in genes encoding proteins involved in regulation of neurite outgrowth and other various synaptic functions (MECP2, TM4SF2/TSPAN7, PPP1R3F, PSMD10, MCF2, SLITRK2, GPRASP2, and OPHN1).

Défaillance multiviscérale au cours d'un choc septique d'origine urinaire à Escherichia coli: syndrome catastrophique des anticorps antiphospholipides?

INTRODUCTION

Although the presence of antiphospholipid antibodies is not an uncommon fact during infection, their responsibility in serious manifestations can still be debated and questions the existence of an actual catastrophic antiphospholipid syndrome or multivisceral faintings, triggered by the infection only, since the presence of antiphospholipid antibodies is not pathogenous.

CASE

A 68-year-old man presented during an Escherichia coli urinary tract infection a septic shock with renal and cardiac insufficiencies, hepatic cytolysis and cholestasis and disseminated intravascular coagulation. There was a significant titer of antiphospholipid antibodies IgG (50 UGPL/ml) with an antibêta2-glycoprotein-1 positivity. The patient quickly recovered with antibiotherapy and intravenous immunoglobulins.

DISCUSSION

Diagnosing the pathogeny of multivisceral faintings is founded of the clinical manifestations published during the catastrophic antiphospholipid syndrome, the evolution and the persistence of post recovery antibodies and the comparison with the visceral bouts that the sepsis exclusively as revealed.

Home intervention in the treatment of asthma among inner-city children

BACKGROUND

In Atlanta, as in other major urban areas of the United States, asthma is a leading cause of school absenteeism, emergency department use, and hospitalization. Recent guidelines for asthma management recommend reducing exposure to relevant allergens, but neither the feasibility nor the efficacy of this form of treatment has been established for children living in poverty.

OBJECTIVE

We sought to investigate allergen avoidance as a treatment for asthma among inner-city children.

METHODS

One hundred four children with asthma living in the city of Atlanta were enrolled into a controlled trial of avoidance without being skin tested. The children were randomized to an active avoidance group, a placebo avoidance group, and a second control group for which no house visits occurred until the end of the first year. Avoidance included bed and pillow covers, hot washing of bedding, and cockroach bait. Eighty-five children completed the study, and the outcome was measured as unscheduled clinic visits, emergency department visits, and hospitalization for asthma, as well as changes in mite and cockroach allergen levels.

RESULTS

There was a significant decrease in acute visits for asthma among children whose homes were visited (P < .001). However, there was no significant difference between the active and placebo homes either in the effect on asthma visits or in allergen concentrations. When the children with mite allergy were considered separately, there was a significant correlation between decreased mite allergen and change in acute visits (P < .01). The avoidance measures for cockroach allergen appeared to be ineffective, and the changes observed did not correlate with changes in visits.

CONCLUSIONS

Applying allergen avoidance as a treatment for asthma among children living in poverty is difficult because of multiple sensitivities and problems applying the protocols in this environment. The current results demonstrate that home visiting positively influences the management of asthma among families living in poverty. Furthermore, the results for children with mite allergy strongly suggest that decreasing relevant allergen exposure should be an objective of treatment in this population.

Biomarkers of immunotoxicity in fish: from the lab to the ocean

Historically, host immunocompetence has been monitored using a battery of immune parameters. Recently, many of these same assays have been employed as biomarkers for predicting chemical-induced immunotoxicity in wildlife species. In this laboratory, assays measuring immunopathology, immune cell function, and host resistance against bacteria have been used successfully to assess immunotoxicity in laboratory-reared Japanese medaka (Oryzias latipes) and in feral fish populations. As an example of the latter, smallmouth bass collected from a PCB-contaminated site demonstrated significantly reduced phagocyte function and antioxidant activity compared to reference site fish. Taken together, these studies along with those from other investigators demonstrate the usefulness of immune assays as indicators to predict the toxicological risk associated with 'real-world' polluted aquatic environments.

Immunoprotective activities of multiple chaperone proteins isolated from murine B-cell leukemia/lymphoma

Although the use of tumor-derived heat shock/chaperone proteins (HSPs) as anticancer vaccines is gaining wider study and acceptance, there have thus far been no reports concerning chaperone antitumor activities against disseminated hematological malignancies. We have devised an efficient and effective method for purification of the chaperone proteins grp94/gp96, HSP90, HSP70, and calreticulin from harvested A20 murine leukemia/lymphoma tumor material. We have demonstrated that these purified proteins, when used as vaccines, can induce potent and specific immunity against a lethal tumor challenge. Individual chaperone proteins were differentially effective in their abilities to provide immune protection. The increase in survival generated by the most effective chaperone vaccine, HSP70, resulted from at least a 2-log reduction in tumor burden. Syngeneic granulocyte macrophage colony-stimulating factor producing fibroblasts were injected at the site of vaccination in an attempt to augment the immune response. Surprisingly, localized granulocyte macrophage colony-stimulating factor production inhibited the protective effects of chaperone vaccination. These studies provide evidence that chaperone proteins can be isolated from B-cell tumors and used effectively to immunize against disseminated lymphoid malignancies.

Perceptions of indigenous workers following participation in a disaster relief project

A survey design was used to elicit workers' perceptions of providing crisis outreach services to survivors of the 1993 flood in Illinois. Findings highlight the benefits of recruiting local workers in disaster relief work. Positive outcomes of the experience include both personal and professional growth.

Outbreak of sterile peritonitis among continuous cycling peritoneal dialysis patients

BACKGROUND

Approximately 30,000 patients receive peritoneal dialysis in the United States. In August 1996, several dialysis centers from different states reported sterile peritonitis among CCPD patients using sterile peritoneal dialysis solution (PDS) from a single manufacturer. The manufacturer recalled 53 lots of PDS that had passed established industry guidelines and Food and Drug Administration (FDA) approved quality control tests [including endotoxin levels <0.5 endotoxin units (EU)/ml], but had pre-sterilization bacterial colony counts >1 cfu/ml.

METHODS

At one outpatient dialysis center, Hospital of the University of Pennsylvania (HUP), we conducted a retrospective cohort study of all CCPD patients treated during July 15 to August 30, 1996. A case-patient was defined as any HUP patient with culture-negative peritoneal fluid with a white blood cell count >100/mm3, cloudy peritoneal fluid, and/or abdominal pain. PDS and tubing were cultured for bacteria and assayed for endotoxin.

RESULTS

Overall, 14 of 28 patients had sterile peritonitis. The only risk factor identified was exposure to > or =1 lot of recalled PDS (14 of 22 vs. 0/6, P = 0.02); the more recalled lots received, the higher the attack rate (P = 0.0001). Five of 47 PDS bags had detectable endotoxin; recalled lots were more likely to have measurable endotoxin than nonrecalled lots (5/19 vs. 0/17, P = 0.05). When case-patients resumed CCPD using PDS from non-recalled lots, no further cases were reported.

CONCLUSIONS

Our results suggest that this outbreak was caused by intrinsic PDS contamination with endotoxin. Pre-sterilization colony counts may be an important quality control indicator for CCPD fluids in conjunction with endotoxin levels.

Comparison of alcohol consumption patterns and social problems between women and men drink-drivers

OBJECTIVE

To compare the sociodemographic characteristics, patterns of alcohol consumption and driving histories of women and men drink-drivers.

DESIGN

Cross-sectional descriptive study.

SETTING AND SUBJECTS

All 156 women who attended the Drink-Drive Program at St Vincent's Hospital, Melbourne, between January 1990 and December 1993, and an age-matched sample of 298 men attending in the same period. All had been disqualified from driving after a conviction for driving under the influence of alcohol.

OUTCOME MEASURES

Self-reported weekly alcohol consumption and expenditure on alcohol at apprehension and during the program; blood alcohol level (BAL) at apprehension; demographic characteristics; number of previous drink-drive and other traffic convictions; and score on the Michigan Alcoholism Screening Test (MAST).

RESULTS

Women had a higher educational level than men, and were more likely to be managers or professionals and to live in areas of high socioeconomic status. Women reported lower levels of weekly alcohol consumption at both apprehension (women: 15.2 standard drinks; men: 31.6 standard drinks) and during the program (women: 7.1 standard drinks; men: 12.0 standard drinks) but had similar BALs to men at apprehension (mean, 0.12% [26 mmol/L]). Sixty percent of women drank wine, or wine, beer and spirits, while 75% of men drank beer. Women had lower MAST scores than men (mean [standard deviation]: women, 5.8 [5.2]; men, 8.9 [8.2]). Women were less likely than men to have prior convictions for drink-driving or other traffic offences.

CONCLUSION

Although women presented with similar blood alcohol levels to men, their drinking patterns and sociodemographic characteristics differ greatly. Health education for women drink-drivers needs to have a different strategy to that for men.

Platelet-derived growth factor indirectly stimulates angiogenesis in vitro

We evaluated the effect of platelet-derived growth factor (PDGF) on capillary formation using an in vitro angiogenesis model system in which microvascular fragments and myofibroblasts (Mfs) isolated from rat epididymal lipid tissues were grown in co-culture. In this system Mfs induce capillary formation by producing an endothelial cell growth factor and by secreting extracellular matrix components that cause endothelial cells to form cordlike structures. Addition of PDGF enhances in vitro capillary growth. Although some recently described microvascular endothelial cells display PDGF receptors and respond to PDGF, we found no evidence for direct PDGF action on the rat epididymal microvascular endothelial cells. Rather, we found that PDGF increased the proliferation of Mfs, as well as the production of Mf-derived endothelial cell growth factor and matrix collagen type I. Our results suggest that even in cases where the microvasculature lacks PDGF receptors, PDGF may accelerate capillary formation by activating connective tissue cells in the vicinity of endothelial cells.

Does a blood alcohol level of 0.15 or more identify accurately problem drinkers in a drink-driver population?

OBJECTIVE

To determine whether a blood alcohol concentration (BAC) of 0.15 or more identifies accurately problem drinking in an apprehended drinking driver.

DESIGN

Cross-sectional analytic study of 86 drink drivers ("diagnostic test study").

SETTING

St Vincent's Hospital, Melbourne, drink-driver education programme.

SUBJECTS

Men aged between 18-25 years, applying for relicensing after disqualification, who were participants at 10 consecutive drink-driver education courses conducted in early 1987.

OUTCOME MEASURES

Self-reports of the amount of alcohol consumed and the amount of money spent on alcohol per week, the standard Michigan Alcoholism Screening Test (MAST) score and the blood alcohol level at apprehension. The first three measures were used as reference standards for alcohol-related problems, against which the blood alcohol level was compared.

MAJOR RESULTS

Scatter plots of BAC against amount consumed, amount spent and the MAST scores showed that a large proportion of the heaviest drinkers were not identified by the BAC. Log-transformed correlation coefficients were: for amount spent v. amount consumed, r = 0.73; for MAST score v. amount consumed, r = 0.52, and for MAST score v. amount spent r = 0.53. Correlating the BAC with the log of the MAST score gave r = 0.21, BAC with log of the amount consumed, r = 0.20, and BAC with log of the amount spent, r = 0.15. Comparing a BAC of 0.15 or more with a MAST score of greater than or equal to 5, we obtained a sensitivity of 0.36, a specificity of 0.76, a positive predictive value of 0.86, and a negative predictive value of 0.23. The prevalence of heavy drinking as measured by the MAST score was 0.80.

CONCLUSION

A blood alcohol concentration of 0.15 or more identifies only a third of the problem drinkers in this sample of drink drivers. Although it selected a group of drinkers with alcohol-related problems, it missed most of the problem drinkers and did not reliably identify the heaviest drinkers.

Automated determination of human choriogonadotropin by use of microparticle capture analysis

We evaluated a new microparticle enzyme immunoassay (MEIA) for human choriogonadotropin (hCG) in serum. This hCG assay is fully automated for the Abbott "IMx System," which has a dynamic range extending to 100,000 int. units/L. We tested 321 patients' sera, with hCG values ranging between 0 and 196,000 int. units/L by both the IMx hCG (y) and the Hybritech Tandem-E hCG (x) assays. Results correlated well (r = 0.972, slope = 0.87, y-intercept = 0.7). The IMx hCG assay is sensitive (0.21 int. units/L) and precise (CVs 2.4-8.7% for various hCG concentrations). No carryover to subsequent specimens was observed when specimens with values up to 10(6) int. units/L were tested, nor was any high-dose "hook" effect noted. The IMx hCG assay, which is specific for intact hCG molecules, is rapid (one to six samples in 17 min) and is a valid automated alternative to enzymatic and radioisotopic methodologies.

Automated determination of human choriogonadotropin by use of microparticle capture analysis

We evaluated a new microparticle enzyme immunoassay (MEIA) for human choriogonadotropin (hCG) in serum. This hCG assay is fully automated for the Abbott "IMx System," which has a dynamic range extending to 100,000 int. units/L. We tested 321 patients' sera, with hCG values ranging between 0 and 196,000 int. units/L by both the IMx hCG (y) and the Hybritech Tandem-E hCG (x) assays. Results correlated well (r = 0.972, slope = 0.87, y-intercept = 0.7). The IMx hCG assay is sensitive (0.21 int. units/L) and precise (CVs 2.4-8.7% for various hCG concentrations). No carryover to subsequent specimens was observed when specimens with values up to 10(6) int. units/L were tested, nor was any high-dose "hook" effect noted. The IMx hCG assay, which is specific for intact hCG molecules, is rapid (one to six samples in 17 min) and is a valid automated alternative to enzymatic and radioisotopic methodologies.

Carboniferous brachiopod migration and latitudinal diversity: a new palaeoclimatic method

Patterns of migration of organisms, coupled with changes in latitudinal diversity, provide useful information for reconstructing palaeoclimate. We apply these tools to the record of 344 articulate brachiopod genera from the Tournaisian, Visean, and Namurian stages of the Carboniferous. Localities from the Northern Hemisphere were assigned to four palaeolatitudinal zones: the palaeoequatorial zone and the low, middle and high latitudes. Generic migrations were tabulated among latitudinal zones for each pair of successive stratigraphic intervals. Latitudinal diversity gradients were calculated based on the number of genera present within each zone.

Two intervals of climatic change were identified by these methods. Between the middle and late Visean, 42% of the genera moved the northern boundary of their range northward, and nonequatorial diversity rose dramatically. These patterns indicate high-latitude warming, which may have been caused by deflection of the circumequatorial current as the collision of Laurussia and Gondwana progressed. Migration and latitudinal diversity patterns indicate both high-latitude cooling and equatorial warming between the Namurian A and B. The onset of Gondwanan glaciation may have been responsible; similar patterns occurred during glacial onset in the Miocene.

The Limulus amebocyte lysate assay. A rapid and sensitive method for diagnosing early gram-negative peritonitis in patients undergoing continuous ambulatory peritoneal dialysis

The Limulus amebocyte lysate (LAL) assay was used in a blinded, prospective fashion to analyze peritoneal fluids from 35 consecutive patients undergoing continuous ambulatory peritoneal dialysis (CAPD), who presented with clinical peritonitis. The results were correlated with standard microbiologic culture results. The LAL assay was positive in all three patients with gram-negative peritonitis, was appropriately negative in 24 of 28 gram-positive infections (sensitivity, 100%; specificity, 86%) and was positive in two of five cases in which there was no microbiologic growth. One of the two patients in this last group yielded a gram-negative organism two days later. It was then demonstrated that therapeutic concentrations of a variety of antibiotics (cefazolin sodium, gentamicin sulfate, tobramycin sulfate, ticarcillin disodium, penicillin G potassium, vancomycin hydrochloride, metronidazole hydrochloride, piperacillin sodium, and trimethoprim/sulfamethoxazole) did not interfere with the LAL assay. Together, these data indicate that the LAL assay is useful for identifying patients at high risk for gram-negative peritonitis and for excluding from possible aminoglycoside exposure the majority of patients with peritonitis undergoing CAPD, most of whom will have gram-positive infections. Furthermore, lack of antibiotic interference allows the possibility of monitoring treatment efficacy.

Virus-associated colitis in homosexual men: two case reports

Two homosexual men with colitis are described. In each case there was evidence of viral infection of the colon. One patient developed toxic megacolon that responded to conservative therapy. The other patient had proctosigmoiditis and opportunistic infections that eventually led to his death. An intensive search for viruses should be made in all homosexual men with proctitis and/or colitis.

[G2 technic : a simplified procedure of reconstitution of the angle of His, applied to the treatment of hiatus hernia and malposition of the greater tuberosity (242 cases) (author's transl)]

A simple procedure of reconstitution of the angle of His applied to the treatment of hiatus hernia and malposition of the greater tuberosity is reported. Applied to 242 cases, it presents compared with the classical procedure several advantages : easy to carry out, including no complex manoevre, it does not endanger the vagus nerve and maintains firmly the anastomosis. Radiological control and, above all, the clinical results were excellent or good in 96% of cases, suggesting that this new procedure is perfectly valid.