Serum microRNA profiles among dioxin exposed veterans with monoclonal gammopathy of undetermined significance

Previously an increased risk for monoclonal gammopathy of undetermined significance (MGUS), a precursor of multiple myeloma (MM), was reported among Vietnam veterans exposed to Agent Orange and its contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Dysregulated expression of certain microRNAs (miRNAs) was demonstrated in MGUS and MM. Given the important role of miRNAs in cellular homeostasis, the aim of this study was to determine if there was an association between serum levels of selected miRNAs and TCDD in 47 MGUS cases identified in our previous investigation using serum specimens and exposure data archived by the Air Force Health Study (AFHS). A total of 13 miRNA levels (let-7a, let-7i, miR-16, miR-20a, miR-21, miR-34a, miR-106b, miR-146a, miR-181a, miR-192, miR-205, miR-335, and miR-361) was measured in serum stored during the 2002 AFHS follow-up and the relationship to lipid-adjusted serum TCDD levels in 1987 was determined. miR-34a showed the strongest relationship with TCDD; after age-adjustment, this positive association was more pronounced. In contrast, the other 12 miRNAs displayed absolute values of age adjusted coefficient estimates below 1.16 and non-significant p-values. The observed strong positive association between high body burdens of TCDD and miR-34a, a tumor suppressor regulated by p53, in this MGUS population warrants clarification of the TCDD-miR-34a relationship and its role in the pathogenesis of MGUS and risk for MM.

Preparation of “Open/closed” pores of PLGA-microsphere for controlled release of protein drug

Poly(D,L-lactic-co-glycolic acid)  has been extensively used as a controlled release carrier for drug delivery due to its good biocompatibility, biodegradability, and mechanical strength. In this study, porous PLGA microspheres were fabricated by an emulsion-solvent evaporation technique using poly ethylene glycol (PEG) as an extractable porogen and loaded with  protein (lysozyme) by suspending them in protein solution. For controlled release of protein, porous microspheres containing lysozyme were treated with water-miscible solvents in aqueous phase for production of pore-closed microspheres. The surface morphology of microspheres were investigated using scanning electron microscopy (SEM) for confirmation of its porous microstructure structure. Protein property after release was observed by enzymatic activity assay. The pore-closing process resulted in nonporous microspheres which exhibited sustained release patterns over an extended period.

Prevalence and associated demographic characteristics of exposure to multiple metals and their species in human populations: The United States NHANES, 2007-2012

Lead (Pb), cadmium (Cd), mercury (Hg), and arsenic (As) are among the top 10 pollutants of global health concern. Studies have shown that exposures to these metals produce severe adverse effects. However, the mechanisms underlying these effects, particularly joint toxicities, are poorly understood in humans. The objective of this investigation was to identify and characterize prevalent combinations of these metals and their species in the U.S. NHANES population to provide background data for future studies of potential metal interactions. Exposure was defined as urine or blood levels ≥ medians of the NHANES 2007-2012 participants ≥6 years (n = 7408). Adjusted-odds ratios (adj-OR) and 95% confidence intervals were determined for covariates (age, gender, and race/ethnicity, cotinine and body mass index). Species-specific analysis was also conducted for As and Hg including iAs (urinary arsenous acid and/or arsenic acid), met-iAs (urinary monomethylarsonic acid and/or dimethylarsinic acid), and oHg (blood methyl-mercury and/or ethyl-mercury). For combinations of As and Hg species, age- and gender-specific prevalence was determined among NHANES 2011-2012 participants (n = 2342). Data showed that approximately 49.3% of the population contained a combination of three or more metals. The most prevalent unique specific combinations were Pb/Cd/Hg/As, Pb/Cd/Hg, and Pb/Cd. Age was consistently associated with these combinations: adj-ORs ranged from 10.9 (Pb/Cd) to 11.2 (Pb/Cd/Hg/As). Race/ethnicity was significant for Pb/Cd/Hg/As. Among women of reproductive age, frequency of oHg/iAs/met-iAS and oHg/met-iAs was 22.9 and 40.3%, respectively. These findings may help prioritize efforts to assess joint toxicities and their impact on public health.

Agent Orange Exposure and Monoclonal Gammopathy of Undetermined Significance: An Operation Ranch Hand Veteran Cohort Study

IMPORTANCE

Multiple myeloma has been classified as exhibiting "limited or suggestive evidence" of an association with exposure to herbicides in Vietnam War veterans. Occupational studies have shown that other pesticides (ie, insecticides, herbicides, fungicides) are associated with excess risk of multiple myeloma and its precursor state, monoclonal gammopathy of undetermined significance (MGUS); however, to our knowledge, no studies have uncovered such an association in Vietnam War veterans.

OBJECTIVE

To examine the relationship between MGUS and exposure to Agent Orange, including its contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), in Vietnam War veterans.

DESIGN, SETTING, AND PARTICIPANTS

This was a prospective cohort study conducted in 2013 to 2014, testing for MGUS in serum specimens collected and stored in 2002 by the Air Force Health Study (AFHS). The relevant exposure data collected by the AFHS was also used. We tested all specimens in 2013 without knowledge of the exposure status. The AFHS included former US Air Force personnel who participated in Operation Ranch Hand (Ranch Hand veterans) and other US Air Force personnel who had similar duties in Southeast Asia during the same time period (1962 to 1971) but were not involved in herbicide spray missions (comparison veterans). Agent Orange was used by the US Air Force personnel who conducted aerial spray missions of herbicides (Operation Ranch Hand) in Vietnam from 1962 to 1971. We included 479 Ranch Hand veterans and 479 comparison veterans who participated in the 2002 follow-up examination of AFHS.

EXPOSURES

Agent Orange and TCDD. Serum TCDD levels were measured in 1987, 1992, 1997, and 2002.

MAIN OUTCOMES AND MEASURES

Risk of MGUS measured by prevalence, odds ratios (ORs), and 95% CIs.

RESULTS

The 479 Ranch Hand veterans and 479 comparison veterans had similar demographic and lifestyle characteristics and medical histories. The crude prevalence of overall MGUS was 7.1% (34 of 479) in Ranch Hand veterans and 3.1% (15 of 479) in comparison veterans. This translated into a 2.4-fold increased risk for MGUS in Ranch Hand veterans than comparison veterans after adjusting for age, race, BMI in 2002, and the change in BMI between 2002 and the time of blood draw for TCDD measurement (adjusted OR, 2.37; 95% CI, 1.27-4.44; P=.007).

CONCLUSIONS AND RELEVANCE

Operation Ranch Hand veterans have a significantly increased risk of MGUS, supporting an association between Agent Orange exposure and multiple myeloma.

Respiratory protective equipment, mask use, and respiratory outcomes among World Trade Center rescue and recovery workers

BACKGROUND

Serious respiratory illnesses have been reported among rescue/recovery workers (RRW) following the World Trade Center (WTC) attacks.

METHODS

We studied RRW enrolled in the WTC Health Registry to assess the effects of different respiratory protection equipment (RPE) types on respiratory outcomes, such as recurrent respiratory symptoms and diseases possibly associated with 9/11 exposures. We performed descriptive and multivariate analyses adjusting for demographics and exposure variables.

RESULTS

A total of 9,296 RRW met inclusion criteria. The strongest predictors of using adequate RPE were being affiliated with construction, utilities or environmental remediation organizations and having received RPE training. Workers who used respirators were less likely to report adverse respiratory outcomes compared to those who reported no/lower levels of respiratory protection.

CONCLUSIONS

Level of respiratory protection was associated with the odds of reporting respiratory symptoms and diseases. Training, selection, fit testing, and consistent use of RPE should be emphasized among emergency responders.

Prevalence of monoclonal B-cell lymphocytosis: a systematic review

BACKGROUND

Individuals with monoclonal B-cell lymphocytosis (MBL) have been identified in clinic outpatients, in unaffected relatives of patients with chronic lymphocytic leukemia (CLL), and in general populations. MBL and its relationship with CLL have been actively investigated over the last decade. This report systematically reviews the prevalence of MBL in the context of the populations studied and the evolution of laboratory methods used to define MBL.

METHODS

To identify published studies that have assessed the prevalence of MBL, we systematically searched the MEDLINE databases and consulted with members of the International MBL Study Group. We reviewed the 10 articles that were identified by this process. We abstracted information on study populations, laboratory tests, criteria for designating MBL, and the reported frequencies.

RESULTS

Three of the ten studies were published in 2009, three between 2007 and 2008, and four between 2002 and 2004. Reported prevalences varied widely, ranging from 0.12 to 18.2%. This variability was clearly associated with both the laboratory methods and the populations studied. MBL was more common among older individuals and kindred of persons with CLL. The most common MBL subtype was CLL-like MBL.

CONCLUSIONS

Large population-based studies of MBL that employ standardized laboratory methods with a consensus case definition are needed to assess prevalence and establish risk factors. These studies should include prospective follow-up of MBL cases to determine the relationship between MBL and CLL. Data from original studies should be reported in sufficient detail to allow future synthesis of information from multiple studies, such as meta-analysis.

Parental exposure to pesticides and childhood brain cancer: U.S. Atlantic coast childhood brain cancer study

BACKGROUND

The etiology of childhood brain cancer remains largely unknown. However, previous studies have yielded suggestive associations with parental pesticide use.

OBJECTIVES

We aimed to evaluate parental exposure to pesticides at home and on the job in relation to the occurrence of brain cancer in children.

METHODS

We included 526 one-to-one-matched case-control pairs. Brain cancer cases were diagnosed at < 10 years of age, and were identified from statewide cancer registries of four U.S. Atlantic Coast states. We selected controls by random digit dialing. We conducted computer-assisted telephone interviews with mothers. Using information on residential pesticide use and jobs held by fathers during the 2-year period before the child's birth, we assessed potential exposure to insecticides, herbicides, and fungicides. For each job, two raters independently classified the probability and intensity of exposure; 421 pairs were available for final analysis. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) using conditional logistic regression, after adjustment for maternal education.

RESULTS

A significant risk of astrocytoma was associated with exposures to herbicides from residential use (OR = 1.9; 95% CI, 1.2-3.0). Combining parental exposures to herbicides from both residential and occupational sources, the elevated risk remained significant (OR = 1.8; 95% CI, 1.1-3.1). We observed little association with primitive neuroectodermal tumors (PNET) for any of the pesticide classes or exposure sources considered.

CONCLUSIONS

Our observation is consistent with a previous literature reporting suggestive associations between parental exposure to pesticides and risk of astrocytoma in offspring but not PNET. However, these findings should be viewed in light of limitations in exposure assessment and effective sample size.

B cells behaving badly

The pathogenesis of B-cell lymphoproliferative disorders in general and B-cell chronic lymphocytic leukaemia in particular appears to involve dysfunctional regulation of humoral and cellular immunity with the subsequent development of genetic aberrations in B cells. In theory, either component may arise de novo or may be influenced by environmental exposures including infectious agents, antigens, genotoxic chemicals, or radiation. As an intermediary within the exposure-disease continuum, monoclonal B-cell lymphocytosis may be a helpful biomarker for teasing out these various contributions to risk. This article introduces a series of papers that resulted from an International Workshop held in May 2007 entitled 'Monoclonal B-cell Lymphocytosis and Chronic Lymphocytic Leukemia: Environmental and Genetic Risk Factors'. Research efforts, such as those described in this issue, should lead to improved interventions, more predictive biomarkers, more effective treatments, and a greater appreciation of how the immune system functions over the entire human lifespan.

Overview of monoclonal B-cell lymphocytosis

Monoclonal B-cell lymphocytosis (MBL) has been the subject of more intensive investigation for the last 10 years. The increased presence of MBL in unaffected, first-degree relatives with familial chronic lymphocytic leukaemia (CLL) suggest that it is surrogate marker for early disease. In normal population studies, MBL is found to be increased in ageing subjects. Consensus criteria for the diagnosis of MBL have been proposed. The differential diagnosis has been further clarified and the prevalence of MBL is most prominent in the elderly. The aetiology of MBL is unknown but probably involves immune mechanism of senescence or altered response. Environmental health studies suggest that exposure to certain toxins may lead to MBL but further work is needed. MBL is a precursor to CLL but may also regress, remain stable or progress to clinical CLL.

Monoclonal B-cell lymphocytosis as a biomarker in environmental health studies

The first studies of monoclonal B-cell lymphocytosis (MBL) in the general population were conducted as part of environmental health investigations that began in 1991. MBL was observed as an unexpected finding when blood samples were immunophenotyped by two-colour flow cytometric methods in common use at that time. The initial observations led to a workshop in 1995, at which case definitions were considered and medical follow-up investigations were recommended. Medical follow-ups were conducted in 1997 and 2003. A total of eight cases of confirmed MBL and three cases of presumptive MBL were identified. This review summarizes the findings from those investigations and discusses the issues related to using MBL as a biomarker in environmental health research and population-based studies.

Prevalence and natural history of monoclonal and polyclonal B-cell lymphocytosis in a residential adult population

BACKGROUND

Monoclonal B-cells can be detected in the peripheral blood of some adults without B-cell malignancies, a condition recently termed monoclonal B-cell lymphocytosis (MBL). The risk of individuals with MBL progressing to a B-cell malignancy is unknown. Polyclonal B-cell lymphocytosis (PCBL) has not been systematically studied in the general population.

METHODS

We obtained lymphocyte subset counts on 1,926 residential adults aged 40-76 years in a series of environmental health studies between 1991 and 1994. We then conducted two follow-ups in 1997 and 2003 on consenting participants with B-cell lymphocytosis, which included nine participants with MBL. To ascertain the clinical implications of MBL, we reviewed medical records and death certificates.

RESULTS

The overall prevalence of MBL was 0.57% (11/1,926): nine cases at baseline and two additional cases identified at follow-up. Two (19%) MBL cases subsequently developed a B-cell malignancy; MBL persisted in the remaining nine cases (81%). All PCBL cases where no clone emerged regressed to normal B-cell counts over the follow-up period. MBL was significantly more frequent in residents near a hazardous waste site than in the control populations (age-adjusted OR 6.2; 95%CI 1.1-36.2).

CONCLUSION

MBL confers an elevated risk for developing a B-cell malignancy, although it occurs only in a minority of cases. PCBL is most often a transient state, but a monoclonal population can emerge and persist. Prospective studies are needed to distinguish stable from progressive forms of B-cell lymphocytosis and to clarify the etiologic role of environmental exposures.

Potential residential exposure to toxics release inventory chemicals during pregnancy and childhood brain cancer

BACKGROUND

Although the susceptibility of the developing fetus to various chemical exposures is well documented, the role of environmental chemicals in childhood brain cancer etiology is not well understood.

OBJECTIVES

We aimed to evaluate whether mothers of childhood brain cancer cases had greater potential residential exposure to Toxics Release Inventory (TRI) chemicals than control mothers during pregnancy.

METHODS

We included 382 brain cancer cases diagnosed at < 10 years of age from 1993 through 1997 who were identified from four statewide cancer registries. One-to-one matched controls were selected by random-digit dialing. Computer-assisted telephone interviews were conducted. Using residential history of mothers during pregnancy, we measured proximity to TRI facilities and exposure index, including mass and chemicals released. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) using conditional logistic regression to estimate brain cancer risk associated with TRI chemicals.

RESULTS

Increased risk was observed for mothers living within 1 mi of a TRI facility (OR = 1.66 ; 95% CI, 1.11-2.48) and living within 1 mi of a facility releasing carcinogens (OR = 1.72 ; 95% CI, 1.05-2.82) for having children diagnosed with brain cancer before 5 years of age, compared to living > 1 mi from a facility. Taking into account the mass and toxicity of chemical releases, we found a nonsignificant increase in risk (OR = 1.25 ; 95% CI, 0.67-2.34) comparing those with the lowest versus highest exposure index.

CONCLUSIONS

Risk of childhood brain cancers may be associated with living near a TRI facility ; however, this is an exploratory study and further studies are needed.

Exposures to air pollutants during pregnancy and preterm delivery

The association between preterm delivery (PTD) and exposure to air pollutants has recently become a major concern. We investigated this relationship in Incheon, Republic of Korea, using spatial and temporal modeling to better infer individual exposures. The birth cohort consisted of 52,113 singleton births in 2001-2002, and data included residential address, gestational age, sex, birth date and order, and parental age and education. We used a geographic information system and kriging methods to construct spatial and temporal exposure models. Associations between exposure and PTD were evaluated using univariate and multivariate log-binomial regressions. Given the gestational age, birth date, and the mother's residential address, we estimated each mother's potential exposure to air pollutants during critical periods of the pregnancy. The adjusted risk ratios for PTD in the highest quartiles of the first trimester exposure were 1.26 [95% confidence interval (CI), 1.11-1.44] for carbon monoxide, 1.27 (95% CI, 1.04-1.56) for particulate matter with aerodynamic diameter < or = 10 microm, 1.24 (95% CI, 1.09-1.41) for nitrogen dioxide, and 1.21 (95% CI, 1.04-1.42) for sulfur dioxide. The relationships between PTD and exposures to CO, NO2, and SO2 were dose dependent (p < 0.001, p < 0.02, p < 0.02, respectively) . In addition, the results of our study indicated a significant association between air pollution and PTD during the third trimester of pregnancy. In conclusion, our study showed that relatively low concentrations of air pollution under current air quality standards during pregnancy may contribute to an increased risk of PTD. A biologic mechanism through increased prostaglandin levels that are triggered by inflammatory mediators during exposure periods is discussed.

The heat-shock protein HslVU from Escherichia coli is a protein-activated ATPase as well as an ATP-dependent proteinase

HslVU in Escherichia coli a new two-component ATP-dependent protease composed of two heat-shock proteins, the HslU ATPase and the HslV peptidase which is related to proteasome beta-type subunits. Here we show that the reconstituted HslVU enzyme degrades not only certain hydrophobic peptides but also various polypeptides, including insulin B-chain, casein, and carboxymethylated lactalbumin. Maximal proteolytic activity was obtained with a 1:2 molar ratio of HslV (a 250-kDa complex) to HslU (a 450-kDa complex). By itself, HslV could slowly hydrolyze these polypeptides, but its activity was stimulated 20-fold by HslU in the presence of ATP. The ATPase activity of HslU was stimulated up to 50% by the protein substrates, but not by nonhydrolyzed proteins, and this stimulation further increased 2-3-fold in the presence of HslV. Concentrations of insulin B-chain that maximally stimulated the ATPase allowed maximal rates of the B-chain hydrolysis. Furthermore, addition of increasing amounts of ADP or N-ethylmaleimide reduced ATP and protein or peptide hydrolysis in parallel. Thus, HslVU is a protein-activated ATPase as well as an ATP-dependent proteinase, and these processes appear linked. Surprisingly, the protein and peptide substrates do not compete with each other for hydrolysis. Lactacystin strongly inhibits protein degradation, but has little effect on peptide hydrolysis, while the peptide aldehydes are potent inhibitors of hydrolysis of small peptides, but have little effect on proteins. Thus, the functional requirements for ATP-dependent hydrolysis of peptides and proteins appear different.

Mutagenesis of two N-terminal Thr and five Ser residues in HslV, the proteolytic component of the ATP-dependent HslVU protease

HslVU in E. coli is a new type of ATP-dependent protease consisting of two heat shock proteins: the HslU ATPase and the HslV peptidase that has two repeated Thr residues at its N terminus, like certain beta-type subunit of the 20S proteasomes. To gain an insight into the catalytic mechanism of HslV, site-directed mutagenesis was performed to replace each of the Thr residues with Ser or Val and to delete the first or both Thr. Also each of the five internal Ser residues in HslV were replaced with Ala. The results obtained by the mutational analysis revealed that the N-terminal Thr acts as the active site nucleophile and that certain Ser residues, particularly Ser124 and Ser172, also contribute to the peptide hydrolysis by the HslVU protease. The mutational studies also revealed that both Thr, Ser103, and Ser172, but not Ser124, are involved in the interaction of HslV with HslU and hence in the activation of HslU ATPase as well as in the HslVU complex formation.

Mutational analysis of the ATP-binding site in HslU, the ATPase component of HslVU protease in Escherichia coli

HslU is the ATPase component of the ATP-dependent HslVU protease in Escherichia coli. To gain an insight into the structure and function of HslU, site-directed mutagenesis was performed to generate a mutation in the ATP-binding site of the ATPase (i.e., to replace the Lys63 with Thr). Unlike the wild-type HslU, the mutant form (referred to as HslU/K63T) could not hydrolyze ATP or support the ATP-dependent hydrolysis of N-carbobenzoxy-Gly-Gly-Leu-7-amido-4-methyl coumarin by HslV. The wild-type HslU (a mixture of monomer and dimer) formed a multimer containing 6-8 subunits in the presence of either ATP or ADP, indicating that ATP-binding, but not its hydrolysis, is required for oligomerization of HslU. However, HslU/K63T remained as a monomer whether or not the adenine nucleotides were present. Furthermore, ATP or ADP could protect HslU, but not HslU/K63T, from degradation by trypsin. These results suggest that the mutation in the ATP-binding site results in prevention of the binding of the adenine nucleotides to HslU and hence in impairment of both oligomerization and ATPase function of HslU.

Factors associated with the decline in cirrhosis death rates among young adults in Allegheny County, Pennsylvania, 1973-1985

From 1973 to 1985, the age-adjusted death rate from liver cirrhosis (International Classification of Diseases, Ninth Revision, code 571) dropped by 62.7% among adults aged 25-54 years in Allegheny County, Pennsylvania. The authors investigated factors associated with this decline by verifying causes of death on death certificates from medical records, coroner's reports, and autopsy reports. Although death rates from cirrhosis were slightly underestimated from death certificates, the underestimation did not alter the declining mortality trend. This decline in rates was significant after adjustment of the age, sex, and race effect using statistical modeling. No significant variability in the time trends was noted between sexes, races, and age groups. Neither did the trends in alcohol-related and "unspecified" cirrhosis differ. However, the trends varied significantly between the cirrhosis deaths certified by the coroner and by noncoroner physicians. From 1973-1975 to 1976-1978, the rate initially dropped by 51% among the coroner cases, whereas it dropped by only 9% among the noncoroner cases. By the period 1982-1985, the death rates of both coroner and noncoroner cases declined to approximately 50% of their 1973-1975 rates. These results suggest that the decline during the years 1973-1985 was real and that the trend was initiated by the pronounced decline during the early years in the coroner-certified cirrhosis deaths.

Vehicular crashes and alcohol involvement in drivers at fault, and related fatalities

This descriptive, population-based retrospective review of coroner's and related law enforcement agency's records, and hospital emergency-room records, evaluates the characteristics of fatal traffic crashes in Allegheny County, Pennsylvania, according to whether the driver at fault had been drinking alcohol or not, and examines the relationship between alcohol consumption of drivers at fault, and their respective victims. Our data suggest that passengers of alcohol-positive drivers are as much at risk for fatal crash injuries as are the drivers themselves. Nondrinking drivers should be designated to avoid such risks. The data also show a substantial proportion of crashes involving BAC-negative victims and alcohol-uninvolved drivers at fault. These non-alcohol-related crashes need further evaluation to enable better methods of prevention.

[Proteinase activity in the isolates of Trichomonas vaginalis according to their pathogenicity]

Ten axenic isolates of Trichomonas vaginalis were subcutaneously injected to the BALB/c mice in order to assess their pathogenicity by means of so-called "mouse assay" method. All the isolates revealed neutral and acid proteinase activities both in their lysates and in culture media, but the specific activities of both proteinases in the severely pathogenic group were significantly higher than the mildly pathogenic group (p < 0.05). In the SDS-PAGE system in which the electrophoretic gels contained 0.4% gelatin as the substrate, five different banding patterns of trichomonal proteinases were detected, and the patterns were closely related with the pathogenicity of the isolates of T. vaginalis. All five bands might be regarded as cysteine proteinases group in the inhibitor assays. The cytotoxicity of the lysates of T. vaginalis to the target Chinese hamster ovarian (CHO) cell line was also significantly different according to the pathogenicity of the isolates, and generally lower in the lysates treated with cysteine proteinase inhibitors than in the control lysates. In summarizing the results, it might be considered that the proteinases of T. vaginalis showing five electrophoretic banding patterns are closely related with the pathogenicity and cytotoxicity of the isolates of T. vaginalis.

Detection of fatal therapeutic misadventures by an urban medico-legal system

Very few population-based studies have evaluated fatal therapeutic misadventures, in particular the adequacy of their detection. We therefore assessed the adequacy of the reporting and detection of fatal therapeutic misadventures in an urban setting medico-legal system. The coroner's files and the related hospital records were reviewed as to the circumstances of the incidents and the adequacy of notification by the care providers in Allegheny County, Pennsylvania, for the period of January 1, 1982 through December 31, 1991. The annual average rate of fatal misadventures was 2.2 per 100,000 hospital admissions or 4.7 per million inhabitants (total 63 cases). The survival time from the occurrence of the misadventure was within 24 h in 60% of the cases. University-related hospitals had double the rate of misadventure fatalities (118.2 per 100,000 beds per year), compared to that in community-based hospitals (53.9 per 100,000 bed per year). In more than half of the cases, the hospitals reported the incidents within an hour from the pronouncement of death, 28.6% within 5 h, and 19% after more than 5 h. In 10 cases (15.9%), the notification by the hospitals was clearly deficient in determining the manner of death. In a few cases, the incident was initially reported by the relatives, by the hospital pathologists, or by the media. A high likelihood of under-reporting of fatal misadventures to the medico-legal system is substantiated by comparing with the results reported by others. The possible measures to increase the monitoring and reporting, and to reduce the related mortality are further discussed.

Quantitative computer tomography in Alzheimer's disease: a re-evaluation

This investigation addresses the question of usefulness of computer-tomographic (CT) scanning in discriminating patients with Alzheimer's disease (AD) from healthy, aged controls. Quantitative measures of brain volume loss found to be significant by other investigators as well as additional unique variables are used to discriminate 58 longitudinally studied patients meeting NINCDS-ADRDA criteria for the clinical diagnosis of probable AD from 59 controls. The sensitivity and specificity of both single CT scan parameters and multivariate models comprised of such CT parameters are explored. Reasons for diagnostic misclassification are also illuminated.

The biosynthesis of the chromophore of phycocyanin. Pathway of reduction of biliverdin to phycocyanobilin

The later stages in the pathway of biosynthesis of phycocyanobilin, the chromophore of phycocyanin, were studied by using radiolabelled intermediates. Three possible pathways from biliverdin IX-alpha to phycocyanobilin were considered. 14C-labelled samples of key intermediates in two of the pathways, 3-vinyl-18-ethyl biliverdin IX-alpha and 3-ethyl-18-vinyl biliverdin IX-alpha, were synthesized chemically and were administered to cultures of Cyanidium caldarium that were actively synthesizing photosynthetic pigments in the light. Neither of these two compounds was apparently incorporated into the phycobiliprotein chromophore, suggesting that two of the three pathways were not operative. By elimination, the results imply that the third possible pathway, which involves phytochromobilin, the chromophore of phytochrome, represents the route for biosynthesis of phycocyanobilin. Unfortunately, since 14C-labelled phytochromobilin is not available, no direct proof of this pathway could be obtained. However, if correct, the present interpretation represents a unified pathway for biosynthesis of all plant bilins, via the intermediacy of phytochromobilin.