Radiation dose to workers due to the inhalation of dust during granite fabrication.

There has been very little research conducted to determine internal radiation doses resulting from worker exposure to ionising radiation in granite fabrication shops. To address this issue, we estimated the effective radiation dose of granite workers in US fabrication shops who were exposed to the maximum respirable dust and silica concentrations allowed under current US regulations, and also to concentrations reported in the literature. Radiation doses were calculated using standard methods developed by the International Commission on Radiological Protection. The calculated internal doses were very low, and below both US occupational standards (50 mSv yr(-1)) and limits applicable to the general public (1 mSv yr(-1)). Workers exposed to respirable granite dust concentrations at the US Occupational Safety and Health Administration (OSHA) respirable dust permissible exposure limit (PEL) of 5 mg m(-3) over a full year had an estimated radiation dose of 0.062 mSv yr(-1). Workers exposed to respirable granite dust concentrations at the OSHA silica PEL and at the American Conference of Governmental Industrial Hygienists Threshold Limit Value for a full year had expected radiation doses of 0.007 mSv yr(-1) and 0.002 mSv yr(-1), respectively. Using data from studies of respirable granite dust and silica concentrations measured in granite fabrication shops, we calculated median expected radiation doses that ranged from <0.001 to 0.101 mSv yr(-1).

First bilateral lobar lung transplant in Ireland: advanced operative strategies in lung transplantation.

Lobar lung transplantation is an option that provides the possibility of transplantation of small size recipients with size-mismatch donor lungs by surgically reducing the size of donor lungs. We report our first experience of bilateral lobar lung transplantation of big donor lungs, in a small size urgently listed recipient, after size reduction. A 24 years old girl with end stage cystic fibrosis received the bilateral lobar lung transplant. She made very good recovery postoperatively and was discharged home two weeks following surgery.

Predicted indoor radon concentrations from a Monte Carlo simulation of 1,000,000 granite countertop purchases.

Previous research examining radon exposure from granite countertops relied on using a limited number of exposure scenarios. We expanded upon this analysis and determined the probability that installing a granite countertop in a residential home would lead to a meaningful radon exposure by performing a Monte Carlo simulation to obtain a distribution of potential indoor radon concentrations attributable to granite. The Monte Carlo analysis included estimates of the probability that a particular type of granite would be purchased, the radon flux associated with that type, the size of the countertop purchased, the volume of the home where it would be installed and the air exchange rate of that home. One million countertop purchases were simulated and 99.99% of the resulting radon concentrations were lower than the average outdoor radon concentrations in the US (14.8 Bq m(-3); 0.4  pCi l(-1)). The median predicted indoor concentration from granite countertops was 0.06 Bq m(-3) (1.59 × 10(-3) pCi l(-1)), which is over 2000 times lower than the US Environmental Protection Agency's action level for indoor radon (148 Bq m(-3); 4 pCi l(-1)). The results show that there is a low probability of a granite countertop causing elevated levels of radon in a home.

Predictability and durability of mitral valve repair in patients with severe degenerative mitral regurgitation in medium sized centres.

INTRODUCTION: Mitral valve repair (MVr) is now the treatment of choice to correct severe degenerative mitral regurgitation (MR). Repair rates vary greatly from centre to centre, and the concept of heart valve centres of excellence has been established. OBJECTIVE: The purpose of this study was to see whether large international centre repair rates, and outcomes, are transferrable to medium-sized centres with an interest in mitral repair. METHODS: Between 2011 and 2018, a total of 346 patients underwent mitral valve surgery by a single surgeon. Of these, 238 consecutive patients had repairs, or attempted repairs for degenerative MR, and are included in this study. RESULTS: The study sample consisted of 71% male patients and had a mean age of 64.4 ± 12.3 years; 66% of the study population had concomitant procedures. The overall repair rate in this cohort is 99%. Mean follow up was 3.7 ± 1.9 years. At 5 years, the freedom from MR ≥ 3+ was 95.9 ± 1.9% and at 7 years 91.1 ± 3.8%. Freedom from reoperation at 5 years was 92.9 ± 3.7%, while the 5 years actuarial survival was 89.1 ± 3.7%. On a multivariate analysis, predischarge echo grade was associated with higher risk of future reoperation (odds ratio (OR) = 21.82, p = 0.05). Only age (OR = 1.3, p = 0.03) was predictive of long-term survival. CONCLUSIONS: In specialised medium-sized heart centres, where the surgical team have undergone specialist mitral training, favourable short- and long-term outcomes are achievable with mitral repair rates similar to those from large international centres of excellence. In these heart centres, early surgery should be considered for all patients with severe degenerative MR.

Heart transplant candidates: factors influencing waiting list mortality.

Cardiac transplantation is a successful treatment for end-stage heart disease. However the number of potential candidates is significantly greater then number of suitable organ donors. We reviewed the characteristics of new transplant candidates presenting for assessment for cardiac transplantation to the Irish Heart & Lung Transplant programme over a one year period. Of 44 patients referred for assessment, 24 (54.5%) were listed for cardiac transplantation. Six have died while awaiting transplantation, seven have been transplanted and eleven remain on the active transplant list. The six month survival rate on the transplant waiting list is 74%. Although the Irish system of organ donation has traditionally provided high organ donation rates in comparison with other countries, the demand for suitable heart donors exceeds supply. Newer methods of promoting and facilitating organ donation may prove beneficial in improving the number of donations and addressing the long waiting time for cardiac transplantation.

DNA alterations and enzyme activities in Japanese medaka (Oryzias latipes) exposed to diethylnitrosamine.

Several molecular and biochemical markers of genotoxicity were adapted for measurement in the medaka, and were used to describe the effects of treatment of the organism with diethylnitrosamine (DEN). DEN treatment inhibited the activity of a detoxication enzyme activity (ethoxyresorufin-O-deethylase) and increased the activity of glutathione-S-transferase. This pattern of response has been described in preneoplastic rodent cells. No O6-ethyl guanine adducts were detected, and a slight, but statistically significant, increase in DNA strand breaks was observed. These results are consistent with the hypothesis that prolonged exposure to high levels of DEN induced alkyltransferase activity which enzymatically removes any O6-ethyl guanine adducts but does not result in strand breaks or hypomethylation of the DNA such as might be expected from excision repair of chemically modified DNA.

Modeling of natural organic matter transport processes in groundwater.

A forced-gradient tracer test was conducted at the Georgetown site to study the transport of natural organic matter (NOM) in groundwater. In particular, the goal of this experiment was to investigate the interactions between NOM and the aquifer matrix. A detailed three-dimensional characterization of the hydrologic conductivity heterogeneity of the site was obtained using slug tests. The transport of a conservative tracer (chloride) was successfully reproduced using these conductivity data. Despite the good simulation of the flow field, NOM breakthrough curves could not be reproduced using a two-site sorption model with spatially constant parameters. Preliminary results suggest that different mechanisms for the adsorption/desorption processes, as well as their spatial variability, may significantly affect the transport and fate of NOM.

Patterns of infant mortality from Armenian parish records: a study from 10 countries of the diaspora, 1737-1982.

Using parish records from 10 different countries with small Armenian communities, this study compared patterns of infant mortality in these countries over a period of 245 years. Deaths registered as aged < or = 1 year were used to estimate the numerator for the infant mortality rates (IMR) while the denominator was estimated from births in the same year based on baptisms in the appropriate registers. To check on the validity of using the baptisms as the denominator for the IMR, records of infant deaths were linked with the baptismal records. Thus, from a sample of 273 infant deaths 78.4% had a baptismal record in the registers of the same church in which the death was recorded. Of the deaths 60% had a recorded cause of death. Over the past 245 years, IMR have fallen substantially in all parishes. However, there were notable exceptions to this general pattern of declining IMR over time. For example, the IMR was tripled in Palestine during the decade of the First World War, possibly as a result of the influx of refugees deported from Turkey. A study of the seasonal occurrence of the deaths revealed peaking of deaths between May and August, a pattern influenced by the relative importance of gastroenteritis as a cause of death during the summer months in Egypt where the majority of these infant deaths were recorded. A review of the most important causes of death helped identify an outbreak of undetermined cause in Belgrade in 1737 and an outbreak of dysentery deaths in Alexandria, Egypt, in 1909.(ABSTRACT TRUNCATED AT 250 WORDS)

PIP: The use of parish records of the Armenian infant mortality rate (IMR) illustrates the trends of IMR over time and among Armenian population in different countries, and indicates the overall health of the population at different stages of development. The data from parish records collected by the Armenian Genealogical Society is reasonably valid as a whole, but suffers from misclassification bias reporting in the cause of death. Cause of death was reported in only 60% of cases. Coding of specific causes was based on List B of the List of 50 Causes from the ICD, 8th Revision. Heaping may occur at age 1, but mortality both above and below age 1 was rounded and may minimize this bias. Bias is reporting neonatal deaths is possible, but 78.4% of deaths were linked to baptismal records. Uniformity of recording systems were established by the Armenian church after 1863. IMR data span a period of 245 years (1737-1982) and includes information from 10 countries having long standing Armenian communities: Singapore, Burma, Bangladesh, Indonesia, India, Egypt, Palestine, Cyprus, Greece, and Belgrade, Yugoslavia. Baptismal records were used to calculate births for the denominator in the IMR. Tabulations were made by the church, which showed variations in the proportion of successful matches of births and deaths. Data were available by age, sex, and geographical distribution and varied through time and seasons. In the analysis of time trends, it was revealed that IMR declined continuously but varied for all countries. In India and the Far East, IMR was consistently lower that the IMR from the Middle East parishes. Greece and Cyprus also had somewhat low IMR. The large settlements of Armenians had the highest IMR; these large communities also were communities with low socioeconomic status. Between 1910 and 1919, IMR from Palestine parishes increased; this may have been due to the refugees fleeting persecution and genocide in Armenia and those deported from Turkey. Economic and health conditions among refugees were known to be poor. Neonatal deaths were higher in countries with low IMR. Peak deaths occurred during the months of May and August. Gastroenteritis was a primary cause of death. The most important causes of death were due to diarrhea and respiratory infections. Neonatal deaths were primarily due to congenital anomalies. Many of the death clusters occurred during peak epidemics.

School-based health care for urban minority junior high school students.

OBJECTIVE: To describe the use of school-based health clinics by urban minority junior high school students. DESIGN: Review of demographic and utilization data collected by service providers during clinic visits. SETTINGS AND PARTICIPANTS: Health clinics in four junior high schools that enrolled predominantly Hispanic students who were residing in an economically disadvantaged, medically underserved New York (NY) school district. RESULTS: Of 5757 students who were enrolled in the schools, 5296 (92%) obtained parental consent to use the clinics, and 3723 (65%) used the clinics during the 1991-1992 academic year. Clinic users were 11 to 15 years old, 50% male and 50% female, 81% Hispanic and 14% black, and 29% sixth graders, 33% seventh graders, and 38% eighth graders. Clinic users made 16,340 clinic visits during the 1991-1992 academic year. Presenting complaints were mental health problems (32%), illness (14%), injury (12%), physical examination (5%), immunization (3%), follow-up (21%), and other (13%). Referral sources were clinic outreach (48%), self (44%), and school personnel (8%). Disposition of visits was on-site treatment (92%), referral to an affiliated hospital (5%), and referral elsewhere (3%). Compared with a nationwide group of high school-based clinics that served predominantly black adolescents, these clinics provided more mental health care (31% vs 21%), similar illness/injury care (32% vs 30%), and less preventive (10% vs 24%) and reproductive/contraceptive (7% vs 12%) care. CONCLUSIONS: Junior high school-based clinics can provide a wide range of primary and preventive health care services for large numbers of medically underserved youths. The provision of mental health services may fill a critical need among inner-city adolescents. Clinic outreach may be necessary to maximize utilization, especially among high-risk students.

Contribution of vasomotion to vascular resistance: a comparison of arteries from virgin and pregnant rats.

Intrinsic oscillatory activity, or vasomotion, within the microcirculation has many potential functions, including modulation of vascular resistance. Alterations in oscillatory activity during pregnancy may contribute to the marked reduction in vascular resistance. The purpose of this study was 1) to mathematically model the oscillatory changes in vessel diameter and determine the effect on vascular resistance and 2) to characterize the vasomotion in resistance arteries of pregnant and nonpregnant (virgin) rats. Mesenteric arteries were isolated from Sprague-Dawley rats and studied in a pressurized arteriograph. Mathematical modeling demonstrated that the resistance in a vessel with vasomotion was greater than that in a static vessel with the same mean radius. During constriction with the alpha1-adrenergic agonist phenylephrine, the amplitude of oscillation was less in the arteries from pregnant rats. We conclude that vasomotor activity may provide a mechanism to regulate vascular resistance and blood flow independent of static changes in arterial diameter. During pregnancy the decrease in vasomotor activity in resistance arteries may contribute to the reduction in peripheral vascular resistance.

Tricuspid valve repair with the Cosgrove-Edwards Annuloplasty System.

The technique of tricuspid valve repair with the Cosgrove-Edwards Annuloplasty System is described. This system provides a measured plication of the tricuspid valve annulus with a technique that is easily reproducible and permits physiologic motion of the tricuspid annulus.

Optimizing mitral valve exposure with conventional left atriotomy.

The standard surgical approach to the mitral valve is accomplished through a longitudinal incision in the left atrium, posterior and parallel to the interatrial groove. Many other surgical approaches have evolved. This report describes a technique of optimizing mitral valve exposure via the standard approach. These modifications are simple, do not lengthen the procedure, and usually obviate the need for more complex maneuvers.

Aortic valve repair after arterial switch operation.

A patient with transposition of the great arteries and a ventricular septal defect underwent an arterial switch operation 15 months after pulmonary artery banding. At 12 years of age, severe neoaortic valve regurgitation, due to dilated aortic sinuses and poor leaflet coaptation, developed. Aortic valve repair involved placement of subcommissural sutures, elliptical excision and tailored reduction of two anterior aortic sinuses, with triangular patch expansion of the proximal ascending aorta. A good result was obtained.

Factors influencing HLA sensitization in implantable LVAD recipients.

BACKGROUND: Patients bridged to transplantation (TX) with the implantable left ventricular assist device (LVAD) may be at increased risk for the development of panel-reactive antibodies (PRA) during support. METHODS: To investigate that, we evaluated 60 patients who received the HeartMate LVAD at our institution, of whom 53 had PRA results available for analysis. T lymphocyte PRA levels were examined before LVAD, at the peak PRA level during LVAD support (PEAK), and just before TX. A PRA level more than 10% was considered indicative of sensitization against HLA antigens. RESULTS: The only factor that had a significant effect on PRA levels before LVAD was patient's sex (1.3% for men versus 7.4% for women; p = 0.005). During LVAD support, peak PRA levels increased significantly and the sex-associated differences were no longer evident (33.3% men, 34.3% women; not significant). At the time of TX, PRAs decreased to 10.9% (men) and 7.0% (women) (not significant). We examined the influence of blood products received before TX on PRA levels. Patients who received less than the median number of total units (median). When examined by the type of blood product, only the number of platelet transfusions significantly increased the peak PRA (median: 46.9%; p = 0.03). Patients who received blood that was leukocyte-depleted tended to have lower TX PRA levels (2.9%) compared with those who did not (13.9%, p = 0.18). Forty-two patients were successfully bridged to TX, with three early and two late deaths after TX. Whereas 39 patients received transplants without intervention, 3 were treated by plasmapheresis with a 77% reduction in their HLA antibody levels at TX as measured by flow cytometry. CONCLUSIONS: Patients with the implantable LVAD are at significant risk for the development of anti-HLA antibodies during support. Although this sensitization is often transient, intervention using plasmapheresis may be useful for some patients.

Risk factors for death after heart transplantation: does a single-center experience correlate with multicenter registries?

BACKGROUND: Risk factors for death after heart transplantation (Tx) are frequently documented from multicenter registries. Although this information is helpful, it reflects a whole range of experiences and results, and may not translate to a particular center. This study was performed to (1) evaluate pre-Tx factors affecting mortality in a single-center experience, and (2) compare these factors with risk factors obtained from multicenter registry reports. METHODS: Review of our transplant database between January 1984 and December 1995 identified 405 adults who received a primary heart Tx. Multiple factors were analyzed, including demographics, Tx era, cytomegalovirus status, United Network for Organ Sharing status of recipient, presence of pulmonary hypertension, previous cardiac operations, mechanical ventilation or circulatory support, ischemia time, number of rejection episodes, and preoperative flow cytometry crossmatching. RESULTS: One- and 5-year survival rates were 87.8% and 73.4%, respectively (Kaplan-Meier). Contrary to multicenter registry reports, our data indicate that reoperative procedures, left ventricular assist device support, increasing donor and recipient age, and ischemia time up to 4.2 hours are not risk factors for death after Tx. Likewise, mode of donor death is not a risk factor affecting outcome. Significant risk factors for mortality identified by multivariate analysis included early transplant era (1984 to 1989; p = 0.002), female donor (p = 0.042), cytomegalovirus-seropositive donor (p = 0.048), high pulmonary vascular resistance (p = 0.018), and intraaortic balloon pump support (p = 0.03). It also identified a positive B-cell flow cytometry crossmatch (p = 0.015) to be a risk factor with univariate analysis. CONCLUSIONS: Our data identify a group of recipients, reportedly at high risk in multicenter registries, who are not at increased risk of death after Tx. This information supports the growing experience with older donors and recipients and with bridged transplants, and has allowed us to expand our donor pool. These prognostic factors at evaluation allow more liberal selection of patients and donors for transplantation.

Sexual, assaultive, and suicidal behaviors among urban minority junior high school students.

OBJECTIVE: A greater understanding of minority adolescents' involvement in sex and violence is an essential precursor to the development of effective prevention programs targeted at inner-city youths. METHOD: To estimate the prevalence of involvement in sexual, assaultive, and suicidal behaviors and to quantify the relative importance of demographic, psychosocial, and behavioral risk factors for those behaviors, a survey was administered in the spring of 1992 to a sample of 3,738 predominantly Hispanic and African-American students attending four junior high schools in an economically disadvantaged, medically underserved New York City school district. The mean age of participants was 13.5 years; 73.7% were Dominican, 6.9% were other Hispanic, and 10.4% were black. RESULTS: Thirty-one percent of males and 7% of females reported involvement in sexual intercourse, 27% of males and 8% of females reported involvement in assaultive behavior and 10% of males and 19% of females reported suicide intentions/attempts. The primary risk factor for sexual intercourse was a belief that involvement in intercourse was common and acceptable among peers. The primary risk factor for assaultive behavior was adverse social circumstances. The primary risk factor for suicide intentions/attempts was symptoms of depression. The risk for involvement in each of the three investigated risk behaviors was substantially increased by involvement in the other two behaviors. CONCLUSIONS: These findings underscore the urgent need for comprehensive sex and violence prevention programs targeted at urban minority junior high school students and suggest factors that may identify students at highest risk.

Ponasterone A: a new ecdysteroid from the embryos and serum of brachyuran crustaceans.

The apolar ecdysteroid present in the developing embryo of the blue crab, Callinectes sapidus Rathbun, is tentatively identified as ponasterone A (2 beta, 14 alpha, 20,22-pentahydroxy-5, beta-cholest-7-en-6-one) on the basis of chromatographic, immunological, and mass spectral evidence. The apolar ecdysteroid present in the serum of land crabs, Gecarcinus lateralis, in the late premolt stages of the intermolt cycle is also tentatively identified as ponasterone A on the basis of chromatographic and immunological evidence.

Video-assisted control of haemorrhage post coronary artery bypass surgery.

Excessive bleeding post coronary artery bypass surgery (CABG) remains a major source of morbidity and mortality. Approaching this bleeding with a resternotomy, while necessary in the vast majority of cases, is associated with an increased incidence of infections and sternal wound complications. A thoracoscopic approach in select patients with a pleural based collection is described.

Imaged thoracoscopic surgery--patent ductus arteriosus ligation.

Video-assisted thoracic surgery (VATS) combines excellent visualization of the intrathoracic structures with a minimally invasive technique. A patient is presented who underwent successful ligation of a patent ductus arteriosus with a video-assisted thoracoscopic technique.

Is use of the pulmonary valve allograft justified as an aortic valve substitute?

Between January 1, 1990, and March 20, 1994, 56 patients had a homograft valve device placed in the aortic position. The mean age at operation was 53.3 years (range 5-77 years). Diagnosis included dominant aortic stenosis in 27 patients (48.2%) and aortic incompetence in 29 (51.8%). Thirteen patients (23.2%) had subacute bacterial endocarditis. Forty-three aortic homografts and 13 pulmonary homografts were placed. Concomitant procedures were performed in 12 patients (21.8%). The hospital mortality was 7.3% (four patients). On follow-up, three pulmonary valves have failed, two between 1 and 5 weeks post implantation. At reoperation a linear cusp fracture was found in all with no evidence of infection. All remaining patients have no, trivial, or mild, aortic regurgitation on echo and remain well. Pulmonary and aortic valves were compared for failure, P = 0.02 suggesting a significant difference between valve substitutes. In conclusion we advise caution in using pulmonary allografts in the aortic position.