Genome-wide QTL mapping of yield and agronomic traits in two widely adapted winter wheat cultivars from multiple mega-environments

Quantitative trait loci (QTL) analysis could help to identify suitable molecular markers for marker-assisted breeding (MAB). A mapping population of 124 F_5:7recombinant inbred lines derived from the cross ‘TAM 112’/‘TAM 111’ was grown under 28 diverse environments and evaluated for grain yield, test weight, heading date, and plant height. The objective of this study was to detect QTL conferring grain yield and agronomic traits from multiple mega-environments. Through a linkage map with 5,948 single nucleotide polymorphisms (SNPs), 51 QTL were consistently identified in two or more environments or analyses. Ten QTL linked to two or more traits were also identified on chromosomes 1A, 1D, 4B, 4D, 6A, 7B, and 7D. Those QTL explained up to 13.3% of additive phenotypic variations with the additive logarithm of odds (LOD(A)) scores up to 11.2. The additive effect increased yield up to 8.16 and 6.57 g m⁻² and increased test weight by 2.14 and 3.47 kg m⁻³ with favorable alleles from TAM 111 and TAM 112, respectively. Seven major QTL for yield and six for TW with one in common were of our interest on MAB as they explained 5% or more phenotypic variations through additive effects. This study confirmed previously identified loci and identified new QTL and the favorable alleles for improving grain yield and agronomic traits.

Characterization of the Mercury pulsed power x-ray source spectrum using multichannel density aerogel Cherenkov detectors

The Aerogel Cherenkov Detector for Cygnus (ACD/C) is a time-dependent, x-ray spectral detector that uses SiO₂ aerogels spanning an index of refraction (n = 1.02-1.07) corresponding to a 1.1-2.3 MeV x-ray energy threshold. The ACD/C was developed for pulsed power x-ray sources like Cygnus located at the Nevada National Site and Mercury located at the Naval Research Laboratory (NRL). Aerogels sit between the measurement capabilities of gas (>2 MeV) and solids such as fused silica (>0.3 MeV). The detector uses an aluminum converter to Compton scatter incoming x-rays and create relativistic electrons, which produce Cherenkov light in an aerogel or a fused silica medium. The ACD/C was fielded at the NRL when Mercury was tuned to produce up to 4.8 MeV endpoint bremsstrahlung. Despite a high radiation and electromagnetic interference background, the ACD/C was able to achieve high signal over noise across five aerogel densities and fused silica, including a signal to noise for a 1.1 MeV aerogel threshold. Previous experiments at Cygnus observed a signal that was comparable to the noise (1×) at the same threshold. The ACD/C observed time-resolved rise and fall times for different energy thresholds of the photon spectrum. Monte Carlo simulations of the ACD/C's aerogel response curves were folded with a simulation of Mercury's photon energy spectrum and agree within the error to the observed result.

Adherence to treatment in children with epilepsy: who follows "doctor's orders"?

PURPOSE

The goal of the present study was to examine sociocultural, medical, family environment, and individual cognitive factors that predict adherence to treatment in children with epilepsy.

METHODS

The study subjects (4-13 years old) were enrolled in a longitudinal seizure study at the first visit to the seizure clinic, attended at least 6 months, and had at least two appointments. Baseline predictors, which were obtained by interview, chart review, and psychometric testing, included sociocultural and family environment, seizure and previous treatment history, child behavior, cognitive functioning (IQ), and family stress. Four latent factors tapping these indicators of risk (acculturative risk, seizure severity, behavior problems, family environment) and two measured variables (IQ and life events) were hypothesized. Outcomes were visit adherence (proportion of scheduled appointments kept, plus proportion without unscheduled contacts), medication report (proportion of visits at which parent report of medication agreed with records), and medication levels (proportion of serum anticonvulsant levels within expected range for dosage). Two-step analytic procedure included confirmatory factor analysis to validate the hypothetical structure of the baseline risk indicators, followed by structural equation modeling to examine longitudinal relations between baseline risk and subsequent adherence outcomes.

RESULTS

Significant prospective relationships included acculturative risk associated positively with visit adherence and medication levels, behavior problems associated negatively with visit adherence and medication levels, family environment associated negatively with medication report, life events associated positively with medication levels and visit adherence, and cognitive functioning (IQ) associated positively with medication levels. Seizure severity was not associated significantly with any adherence outcome. There also were no significant within-time associations between adherence outcomes.

CONCLUSIONS

Contrary to clinical expectations, families at higher acculturative risk and with higher life events reported greater adherence. Seizure severity did not influence adherence. The three adherence measures were statistically independent of each other.

Pacemaking in interstitial cells of Cajal depends upon calcium handling by endoplasmic reticulum and mitochondria

Pacemaker cells, known as interstitial cells of Cajal (ICC), generate electrical rhythmicity in the gastrointestinal tract. Pacemaker currents in ICC result from the activation of a voltage-independent, non-selective cation conductance, but the timing mechanism responsible for periodic activation of the pacemaker current is unknown. Previous studies suggest that pacemaking in ICC is dependent upon metabolic activity 1y1yand1 Ca2+ release from intracellular stores. We tested the hypothesis that mitochondrial Ca2+ handling may underlie the dependence of gastrointestinal pacemaking on oxidative metabolism. Pacemaker currents occurred spontaneously in cultured ICC and were associated with mitochondrial Ca2+ transients. Inhibition of the electrochemical gradient across the inner mitochondrial membrane blocked Ca2+ uptake and pacemaker currents in cultured ICC and blocked slow wave activity in intact gastrointestinal muscles from mouse, dog and guinea-pig. Pacemaker currents and rhythmic mitochondrial Ca2+ uptake in ICC were also blocked by inhibitors of IP3-dependent release of Ca2+ from the endoplasmic reticulum and by inhibitors of endoplasmic reticulum Ca2+ reuptake. Our data suggest that integrated Ca2+ handling by endoplasmic reticulum and mitochondria is a prerequisite of electrical pacemaking in the gastrointestinal tract.

An investigation of the effect of 2 sedation regimens on patient mood state following upper extremity surgery using local anesthesia

Sedation techniques for patients undergoing minor outpatient surgery frequently include a variety of intravenous agents. The present study was designed to look for differential effects of 2 different sedation regimens on perioperative mood states. Twenty-two patients undergoing upper extremity surgery using local anesthesia were randomized to receive either propofol or midazolam intravenously for intraoperative sedation. Subjects were asked to complete a Profile of Mood States survey before and after surgery. The results of this survey were examined for differences in mood between the 2 groups that may be attributable to differences in drug effect. No significant differences were identified between propofol or midazolam regarding their effect on patient mood. Patients in both groups experienced a reduction in perioperative anxiety.

Self-inflicted and unintentional firearm injuries among children and adolescents: the source of the firearm

CONTEXT

The source and ownership of guns used by children to shoot themselves or others is largely unknown.

OBJECTIVE

To determine the ownership and usual storage location of firearms used in unintentional and self-inflicted intentional firearm deaths and injuries.

DESIGN

Retrospective case series.

SETTING

King County, Washington.

PATIENTS

Youths aged from birth to 19 years who sought medical treatment at a level I trauma center for a self-inflicted or unintentional firearm injury between 1990 and 1995 or who presented to the county medical examiner with a fatal self-inflicted or unintentional firearm injury between 1990 and 1995.

DATA SOURCES

County medical examiner records, regional police investigative reports, medical records from a level I trauma center, and surveys of victims' families.

MAIN OUTCOME MEASURES

Source and ownership of the associated firearm.

RESULTS

Fifty-six fatal injuries and 68 nonfatal firearm injuries that met the criteria were identified. Of these, 59 were intentionally self-inflicted deaths and injuries and 65 were unintentional deaths and injuries. A firearm owned by a household member living with the victim was used in 33 (65%) of 51 suicides and suicide attempts and 11 (23%) of 47 unintentional injuries and deaths. Additionally, a firearm owned by another relative, friend, or parent of a friend of the victim was used in 4 (8%) of the 51 suicides and suicide attempts and 23 (49%) of the 47 unintentional injuries and deaths. Parental ownership accounted for 29 (57%) of the 51 suicides and suicide attempts and 9 (19%) of the 47 unintentional injuries and deaths. More than 75% of the guns used in suicide attempts and unintentional injuries were stored in the residence of the victim, a relative, or a friend.

CONCLUSION

Most guns involved in self-inflicted and unintentional firearm injuries originate either from the victim's home or the home of a friend or relative.

Using the theory of reasoned action (TRA) to understand the decision to use condoms in an STD clinic population

The theory of reasoned action (TRA) provides useful information when designing health education interventions. In this study, 703 heterosexual STD clinic clients responded to a TRA-based survey. With steady partners, social norms and attitudes toward condom use were significant predictors of intention for both men and women. The interaction of attitude and norm increased prediction for men (R = .64, p < 0.001) and women (R = .70, p < 0.001). With casual partners, attitude was a predictor for men and social norm was a predictor for women. Prior use of condoms increased prediction for men (R = .38, p < 0.001) and women (R = .47, p < 0.001). Findings suggest that, in addition to traditional TRA model variables, the relationship between sexual partners and the individual's prior experience with condom use should be incorporated into attempts to understand this complex, dyadic behavior. Examining specific outcome and normative beliefs also provides important information for intervention design.

Quality and patients' expectations of a surgical admission: a Welsh perspective

The authors report a study undertaken to identify the expectations of patients before a surgical admission. Respondents experienced difficulty in articulating their expectations of surgery. Interviewees believed that the level of information available before admission was unsatisfactory.

Development of techniques to genetically manipulate members of the genera Cytophaga, Flavobacterium, Flexibacter, and Sporocytophaga

The Bacteroides-Cytophaga-Flavobacterium branch of the eubacterial phylogenetic tree contains a diverse group of bacterial species. Techniques for the genetic manipulation of Bacteroides spp. are well developed (A. A. Salyers, N. B. Shoemaker, and E. P. Guthrie, Crit. Rev. Microbiol. 14:49-71, 1987). Recently we developed techniques to genetically manipulate the gliding bacterium Cytophaga johnsonae (M. J. McBride and M. J. Kempf, J. Bacteriol. 178:583-590, 1996). We now demonstrate that some of these techniques allow genetic manipulation of a number of environmentally or medically significant bacteria in this group. The Bacteroides transposon Tn4351 was introduced into Cytophaga hutchinsonii, Cytophaga succinicans, Flavobacterium meningosepticum, Flexibacter canadensis, Flexibacter sp. strain FS1, and Sporocytophaga myxococcoides by conjugation. Tn4351 integrated itself into the host chromosomes and conferred erythromycin resistance. We isolated several auxotrophic mutants of Flavobacterium meningosepticum following Tn4351 mutagenesis. The C. johnsonae-Escherichia coli shuttle vector pCP11 functioned in C. succinicans but not in the other bacteria. pLYL03 did not replicate in any of these bacteria and should function as a convenient suicide vector. The identification of a system of gene transfer, a selectable marker, a suicide vector, and a transposon that functions in these diverse bacteria allows genetic manipulations to be performed.

Airborne transmission of respiratory diseases

In surveys during the past decade, CEs and BMETs have reported an increasing frequency of respiratory illnesses they believed to be acquired as a result of their occupation. These illnesses varied from mild to severe in terms of long-term prognosis. With the increasing numbers of cases of drug-resistant organisms, respiratory infections are a growing concern for healthcare workers, employers, and government officials. Armed with a better knowledge base about symptoms, transmission and prevention, CEs and BMETs will be more aware of potential biohazardous situations and the necessary personal protective measures to be employed. Both the Occupational Safety and Health Administration (OSHA) and the Centers for Disease Control and Prevention (CDCP) have issued guidelines for preventing airborne transmission of infectious diseases. This paper addresses the respiratory illnesses reported by CEs and BMETs as occupational concerns, as well as briefly discussing potential epidemic pulmonary conditions.

Hepatitis: protecting BMETs & CEs

Hepatitis is the primary occupational hazard for healthcare workers. Not until the 1970s were hepatitis viruses isolated and identified as types A and B. In the late 1970s, hepatitis D was discovered as a major cause of fulminant hepatitis. Soon, it was evident that another type was also at work. Because testing was only available for types A and B, the new category was referred to as non-A, non-B. In the 1980s, scientists identified two more viruses from this non-A, non-B group, namely hepatitis E and hepatitis C. These five types of hepatitis have different modes of transmission. The fecal-to-oral route is the mode of transmission for hepatitis types A and E. But, types B and D are bloodborne pathogens. With the advent of a safe vaccine for hepatitis B, this category is declining. To date, hepatitis C appears to have multiple routes of transmission, with half the cases being posttransfusion. In the United States, 85,000 people per year develop chronic hepatitis C, which ultimately leads to severe liver damage. This paper addresses each of the five viruses that have been grouped by routes of transmission, prevention techniques for BMETs and CEs, and statistics of reported cases to the Centers for Disease Control and Prevention (CDCP) over the last 20 years.

Psychosocial, behavioral, and medical outcomes in children with epilepsy: a developmental risk factor model using longitudinal data

OBJECTIVE

We studied factors predicting the risk of adverse long-term psychosocial, behavioral, and medical outcomes in children with epilepsy.

METHODS

Children (N = 157, 4.5 to 13 years) were enrolled in a prospective longitudinal study when first seen. Potential subjects were excluded if they were moderately or severely mentally retarded, had motor or sensory handicaps interfering with testing, or did not speak either English or Spanish.

MEASURES

To develop risk predictors, we collected information regarding the child's medical and seizure history, cognitive functioning, and behavior problems, and family functioning. Children and their families were followed for a minimum of 18 months, then underwent reassessment of medical status, parent's attitudes toward epilepsy, and the child's behavioral and cognitive functioning. Data were analyzed by confirmatory factor analysis to develop baseline factors (Sociocultural Risk, Seizure Risk, and Behavior Problems) and outcome factors (Medical/Seizure Problems, Parent's Negative Attitudes Toward Epilepsy, and Behavior Problems), followed by structural equation modeling to determine across-time causal effects. Eighty-eight subjects completed all baseline and outcome measures.

RESULTS

Among significant across-time effects, Medical Outcome was predicted by Seizure Risk. An increased number of stressful life events predicted better Medical Outcome. Low acculturation increased Parent's Negative Attitudes and was associated with increased Behavior Problems at baseline. Behavior Problems were stable across time. It is interesting that IQ did not affect any of the outcomes, although its effect may have been mediated through other baseline measures.

CONCLUSIONS

Seizure history was the best predictor of ongoing medical difficulties, whereas the most important causes of ongoing parental anxiety and negative attitudes toward epilepsy were sociocultural. Variation in medical or attitudinal outcomes was not influenced by either the child's IQ or reported behavioral problems. These findings suggest that to alter attitudes toward epilepsy, programs should be tailored to the sociocultural background of the family. Studies of quality of life of children with epilepsy should include appropriate sociocultural measures.

AIDS: a new frontier in epidemiology

HIV infection has become a pandemic. As such, it is the most recent inclusion to epidemiology studies. A review of past epidemics allows a different perspective on the current status of scientific knowledge regarding AIDS. HIV is a retrovirus, one of three groups identified. The other two groups are commonly referred to as HTLV I and II and do not cause AIDS. Two forms of HIV (HIV-1 and HIV-2) make up the third group, HTLV-III. As with any research, various theories are formed, tested, and often rejected. Some theories receive excessive publicity before testing, resulting in incorrect public beliefs that become myths. The cumulative number of cases of AIDS in the United States is 361,509, as of December 31, 1993. Healthcare workers experience multiple opportunities for exposure to the infection in the course of their duties. Based on data from the 1993 BMET/CE survey, several biohazard issues, as well as preventive measures, are discussed.

Beliefs about condoms and their association with intentions to use condoms among youths in detention

PURPOSE

Youths in detention have been identified as a high-risk group for AIDS. To help inform AIDS-prevention efforts targeted for these youths, we surveyed youths in detention regarding their sexual behaviors, beliefs about condoms, intentions to use condoms, and actual condom use. We examined race and gender differences in these beliefs and behaviors, and we studied the relationship of these beliefs to condom-use intentions.

METHODS

Questionnaires were administered to a sample of 201 youths in detention who were, on average, 16 years old. The sample was stratified on gender and race (African-American and white), with approximately equal numbers in each group.

RESULTS

The results indicate that these youths had engaged in behaviors that put them at high risk of acquired immunodeficiency syndrome (AIDS) and other sexually transmitted diseases. Although they used condoms somewhat more consistently with casual partners than with their steady partners, the majority did not use condoms consistently with either partner type. Very few race or gender differences were found with regard to condom use, intentions to use condoms, or beliefs about the consequences of using condoms. Beliefs associated with intentions to use condoms with steady partners included protection against sexually transmitted diseases (STDs), and the beliefs that condoms reduce pleasure, are artificial, unromantic, and interrupt sex. In contrast, only the belief that condoms prevent pregnancy was related to intentions to use condoms with casual partners.

CONCLUSION

The results suggest that interventions targeted at African-American and white males and females in detention need not differ greatly in content as long as they include the most salient concerns of each group; that interventions include content on the two protective benefits of condom use (pregnancy and STD prevention), as well as on how to minimize the perceived negative aspects of condom use; that they stress the need for condom use with steady as well as casual partners; and that they stress that anal intercourse is especially risky with regard to AIDS transmission.

A 1993 update on biohazards affecting clinical engineers and BMETs

In late 1993, a survey was sent to the subscribers of the Journal of Clinical Engineering to determine: (1) if employers were responding to the biohazards protection needs of BMETs and CEs; (2) if personal protective equipment was being utilized; (3) if occupational exposure perceptions and concerns had changed since a previous survey four years ago; and (4) if educational efforts targeting BMETs and CEs were still needed. The 267 respondents were divided into four groups according to certification status and job title. Results showed that employers were doing an excellent job of providing personal protective equipment, but 50% of the BMETs and CEs chose not to use it. Even though though the occupational exposure illness and disability rate increased to 21% from the 1989 survey rate of 18%, BMETs and CEs still feel confident in their abilities to recognize potential biohazard problems based on visual clues, which can be an error in judgement that can lead to serious adverse effects including illness, disability, or death.

Functional role for the M2 muscarinic receptor in smooth muscle of guinea pig ileum

A functional role for the M2 muscarinic receptor in smooth muscle contraction was investigated in isolated guinea pig ileum. Contractile responses to the muscarinic agonist oxotremorine-M (oxo-M) were measured in isolated ilea that had been pretreated with histamine (0.32 microM) and isoproterenol (0.64 microM) to achieve conditions of elevated cAMP. The resulting concentration-effect curve was biphasic, consisting of high (0-50 nM) and low (> 50 nM) potency components. The reversible M2-selective antagonist AF-DX 116 ([[2-[(diethylamino)methyl]-1-piperidinyl]acetyl]-5,11- dihydro-6H-pyrido[2,3b][1,4]benzodiazepine-6-one) (1 and 10 microM) shifted this curve in a manner that was inconsistent with competitive antagonism at a single receptor site; the high affinity component was significantly blocked, whereas there was little effect on the low affinity portion of the curve. To inactivate the M3 muscarinic receptors selectively, ilea were incubated with the irreversible M1/M3-selective muscarinic antagonist 4-DAMP mustard [N-(2-chloroethyl)-4-piperidinyldiphenylacetate] (40 nM) for 1 hr in the presence of AF-DX 116 (1 microM) and were then washed extensively. Under these conditions, the contractile responses to oxo-M, in the presence of histamine and isoproterenol or forskolin, were antagonized by AF-DX 116 (1 microM) in a manner consistent with that mediated by an M2 receptor. AF-DX 116 caused 6.6- and 11-fold increases in the EC50 value for oxo-M for ilea pretreated with isoproterenol and forskolin, respectively, and a significant increase in the Hill coefficient in both cases. Under basal conditions, AF-DX 116 caused only a 1.34-fold increase in the EC50 value and no change in the Hill coefficient. In addition, under basal conditions 4-DAMP mustard treatment shifted the oxo-M contractile response curve to the right approximately 20-fold. However, when histamine was present in combination with isoproterenol or forskolin 4-DAMP mustard treatment shifted the concentration-effect curves for oxo-M to the right only about 3.5-fold. Oxo-M produced an M3-mediated stimulation of phosphoinositide hydrolysis in the longitudinal muscle of rat ileum with an EC50 value of 30 microM. 4-DAMP mustard (10 nM; 1 hr) prevented this response, resulting in a 6.6-fold increase in the EC50 value with a 65% reduction of the maximal response. In contrast, this treatment blocked M2-mediated inhibition of isoproterenol-stimulated adenylate cyclase with only a 2-fold increase in EC50, without affecting maximum inhibition.(ABSTRACT TRUNCATED AT 400 WORDS)

A comparison of tests of the difference in the proportion of patients who are cured

We compared by simulation the likelihood ratio, Wald, and score tests based on a mixture model similar to that proposed by Farewell (1982, Biometrics 38, 1041-1046), and a simple nonparametric test based on the plateau value of the product-limit estimate, for testing the difference in cured proportions between two groups. The parametric tests obtained their asymptotic properties even in small samples provided that one could assume equal failure rates in the two groups. Otherwise, good agreement with predictions required that essentially all potential failures had been observed. The comparative properties of the parametric tests depended on whether the population survival functions crossed, with the power of the Wald test as good as or better than the others in the common situation when the survival functions do not cross. However, its size was sometimes less than nominal. The score test was often not defined and is therefore of limited value. The product-limit test often performed as well as the parametric tests, and despite being biased in some circumstances, may be a useful alternative to these, especially in small samples when some potential failures have not been observed.

Reaction time, impulsivity, and attention in hyperactive children and controls: a video game technique

Maturation of sustained attention was studied in a group of 52 hyperactive elementary school children and 152 controls using a microcomputer-based test formatted to resemble a video game. In nonhyperactive children, both simple and complex reaction time decreased with age, as did variability of response time. Omission errors were extremely infrequent on simple reaction time and decreased with age on the more complex tasks. Commission errors had an inconsistent relationship with age. Hyperactive children were slower, more variable, and made more errors on all segments of the game than did controls. Both motor speed and calculated mental speed were slower in hyperactive children, with greater discrepancy for responses directed to the nondominant hand, suggesting that a selective right hemisphere deficit may be present in hyperactives. A summary score (number of individual game scores above the 95th percentile) of 4 or more detected 60% of hyperactive subjects with a false positive rate of 5%. Agreement with the Matching Familiar Figures Test was 75% in the hyperactive group.

Methemoglobinemia: the hidden diagnosis

Although methemoglobinemia is not commonly seen in the ER or the critical care setting, it can be life threatening if unrecognized and left untreated. A detailed case history illustrates the symptoms and some of the possible precipitating factors, and outlines treatment for a successful patient outcome.

Methemoglobinemia: the hidden diagnosis

Although methemoglobinemia is not commonly seen in the ER or the critical care setting, it can be life threatening if unrecognized and left untreated. A detailed case history illustrates the symptoms and some of the possible precipitating factors, and outlines treatment for a successful patient outcome.

Occupational biohazards affecting clinical engineers & BMETs. Part V: Skin and urogenital diseases

BMETs and clinical engineers must be aware of the biological hazards they face in the hospital so they can take precautions to avoid work-related illnesses. A need for educational material on the subject prompted this series of papers examining various biohazards. This paper, the last in the series, reviews a variety of common diseases of the skin and urogenital systems. Common pathogens, their routes of transmission, isolation precautions, and infection control techniques are discussed. The precautions cited are not intended to constitute a full infection control program. Persons interested in further information are advised to contact the infection control officer at their facility, or the Centers for Disease Control.

Occupational biohazards affecting clinical engineers & BMETs. Part IV: Respiratory and gastrointestinal systems

A previously published survey indicated that clinical engineers and BMETs may not be aware of the scope of biological hazards they may encounter in their work (Baker, 1989). In this third article of a four-part series, various pathogens affecting the respiratory and gastrointestinal systems are discussed. Infection hazards and methods of transmission are examined, and recommendations are provided to help ensure the safety of CEs, BMETs, and patients. The recommendations presented include suggested disinfection procedures for contaminated equipment. Persons interested in further information are advised to contact the infection control officer at their facility, or the Centers for Disease Control.

Occupational biohazards affecting clinical engineers & BMETs. Part III: Blood and other body fluids

Results of a previously reported survey of BMETs and CEs indicated a need for further education of these professionals concerning work-related biohazards. In this third article of a five-part series, the dangers of disease transmission by blood and other body fluids are discussed. Susceptibility factors are cited to indicate those persons at greatest risk of infection, and recommendations are provided to assist BMETs and CEs in effectively protecting both themselves and other clinical and nonclinical personnel from infection. The recommendations presented include suggested disinfection procedures for contaminated equipment. Persons interested in further information are advised to contact the infection control officer at their facility, or the Centers for Disease Control.

Occupational biohazards affecting clinical engineers & BMETs. Part II: Common biohazard questions

Worldwide concern about AIDS has prompted concern over the prevention of, and protection from, a variety of biological hazards. Healthcare workers are at greater risk for contracting and/or transmitting certain types of contagious disease organisms because of the nature and environment of their work. In response to requests from BMETs, the author developed an educational presentation on work-related biohazards. This article, the second in a five-part series, addresses some questions commonly raised by more than 300 biomedical personnel who have attended the presentation. Recommendations are also made to help BMETs and CEs avoid occupationally acquired illnesses.

Occupational biohazards affecting clinical engineers & BMETs. Part I: Preliminary survey of perceived hazards

The authors developed this preliminary survey in order to collect current information to answer three questions: 1) Is there reason to be concerned about the occupational health and safety of BMETs; 2) Is a larger study needed; and 3) Is continuing education about certain classes of hazards desirable? Of the 136 BMETs completing the questionnaire, 18.4% reported illnesses or disabilities believed to be job related. More than 90% of the respondents indicated a need for additional training on biological hazards in the workplaces of BMETs; likewise, 86% desired additional training on hazards related to chemicals, fire, and explosion.

Immunogenicity of malondialdehyde-modified low density lipoproteins. Studies with monoclonal antibodies

Malondialdehyde (MDA)-modified low density lipoprotein (LDL) can stimulate the accumulation of cholesteryl esters in cultured macrophages through its interaction with specific scavenger receptors. It has been speculated that such interaction occurs in vivo thus contributing to the formation of foam cells within atherosclerotic lesions. This report describes the development of new tools in the form of a specific assay for MDA-LDL to investigate this hypothesis. We have immunized BALB/c mice with malondialdehyde mouse low density lipoproteins and antibodies against malondialdehyde human low density lipoproteins were generated. Monoclonal antibodies were produced using hybridoma techniques and one particular clone (EB 7-3) was expanded for further studies. The immunoreactivity of several antigens was tested using antibody EB 7-3 in an enzyme-linked immunosorbent assay (ELISA). In a typical assay malondialdehyde human LDL (with at least 40% of lysines modified) was coated (2 micrograms/ml, 100 microliter) in 96-well microtiter plates. Antibody plus one of several antigens were then added and the interaction between the antibody and coated antigen was measured using alkaline phosphatase-conjugated affinity purified goat anti-mouse immunoglobulin. The binding of antibody EB 7-3 to wells coated with malondialdehyde-LDL was competitively inhibited by malondialdehyde-LDL added in solution, with half maximal inhibition occurring at 150 +/- 80 ng/ml. In addition, the ability of malondialdehyde-LDL to inhibit this interaction was proportional to the degree of modification: the more lysines were modified the more did malondialdehyde-LDL inhibit the binding of antibody EB 7-3 to coated malondialdehyde-LDL.(ABSTRACT TRUNCATED AT 250 WORDS)

Purification and structural characterization of herpes simplex virus glycoprotein C

Purification of herpes simplex virus glycoprotein C (gC) in microgram amounts yielded sufficient material for an analysis of its secondary structure. Purification was facilitated by using the mutant virus gC-3, which bears a point mutation that interrupts the putative hydrophobic membrane anchor sequence, causing the secretion of gC-3 protein into the cell culture medium. gC-3 protein was purified by size fractionation of concentrated culture medium from infected cells on a gel filtration column of Sephacryl S-200, followed by immunoaffinity chromatography on a column constructed of gC-specific monoclonal antibodies cross-linked to a protein A-Sepharose CL-4B matrix. Purified gC-3 had a molecular weight of 130,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the size expected for gC, was reactive with gC-specific monoclonal antibodies in protein immunoblots, and contained amino acid sequences characteristic of gC as determined by radiochemical amino acid microsequence analyses. Polyclonal antisera obtained from a rabbit immunized with gC-3 reacted with wild-type gC in immunoprecipitation, enzyme immunoassay, and immunoelectroblot (western blot) assays. Deglycosylation by treatment with trifluoromethanesulfonic acid reduced the molecular weight of gC-3 by approximately 35%. Analyses of both native and deglycosylated gC-3 by Raman spectroscopy showed that the native molecule consists of about 17% alpha-helix, 24% beta-sheet, and 60% disordered secondary structures, whereas deglycosylated gC-3 consists of about 8% alpha-helix, 10% beta-sheet, and 81% disordered structures. These data were in good agreement with the 11% alpha-helix, 18% beta-sheet, 61% beta-turn, and 9% disordered structures calculated from Chou-Fasman analysis of the primary sequence of gC-3.