Effect of warning on feigned malingering on the WAIS-R in college samples

Research indicates claimant malingering of cognitive deficits to be common in personal injury litigation. Efforts have been made to either detect such tendencies or deter efforts at malingering. The present study examined whether warning people that feigned malingering efforts would be detected results in more valid profiles on the Wechsler Adult Intelligence Scale-Revised. Undergraduates (N = 48) were randomly assigned to one of three conditions: feigned malingerers without warning, feigned malingerers with warning, and controls. Analysis indicated both feigned malingerer groups performed significantly worse than the control group; however, feigned malingerers with warning did not perform significantly better than those without warning. Unlike previous research using the Wechsler Memory Scale-Revised, results did not support effectiveness of warning in reducing feigned malingering scores.

Paradoxical effects of resveratrol on the two prostaglandin H synthases

Prostaglandin H synthase (PGHS) is the primary enzyme responsible for the biosynthesis of prostaglandins and thromboxanes. Of the two isoenzymes of PGHS, PGHS-1 is constitutively expressed and PGHS-2 is inducible by mitogens or other inflammatory stimuli. Constitutive expression of PGHS-2 in neoplastic tissues has been implicated in carcinogenesis. Resveratrol, a lignan, was recently shown to be an anticarcinogen that selectively inhibits PGHS-1. In vitro experiments to resolve these seemingly paradoxical observations revealed that resveratrol is not only an inhibitor of PGHS-1 but also is an activator of PGHS-2. Resveratrol non-competitively inhibited PGHS-1 with a K1 of 26 +/- 2 microM but enhanced the PGHS-2 activity nearly twofold. Additionally, resveratrol did not serve as a reducing co-substrate for the peroxidase activities of either enzyme despite being an easily oxidizable phenolic compound. Resveratrol inhibited the peroxidase activity of PGHS-1 (IC50 = 15 microM) better than that of PGHS-2 (IC50 = > 200 microM). Inhibition of the perxidase activity but not the cyclooxygenase activity of PGHS-2 resulted in the production of PGG2 from arachidonic acid. A plausible relationship between these observation and the anticarcinogenic activity of resveratrol is discussed.

Primed neutrophils require phosphatidic acid for maximal receptor-activated elastase release

BACKGROUND

Priming of neutrophils (PMNs) for protease release is believed to be central to the pathogenesis of PMN-mediated tissue injury observed in ARDS/MOF. Defining the intracellular signaling pathways involved with this excessive protease release may aid in establishing future therapies for ARDS. Phospholipase D (PLD) production of phosphatidic acid (PA) is thought to be pivotal in reactive oxygen species generation but its role in degranulation (i. e., protease release) remains unclear. Our hypothesis was that primed neutrophils require PLD production of PA for maximal activated release of elastase.

METHODS

Isolated human PMNs were incubated with a well described antagonist of PA production, ethanol (ETOH, 100-1000 mg/dL), and then primed (PAF, 200 nM) followed by activation (fMLP, 1 microM). To mimic fMLP receptor-dependent activation, PMNs were primed and then directly activated with exogenous dioctanoyl l-alpha-phosphatidic acid (PA8, 0.5-200 microM). To confirm the importance of PA in elastase release, PA8 was given to primed-activated PMNs after ethanol pretreatment in an attempt to recover the maximal response. Elastase release was measured by the cleavage of AAPV-pNA.

RESULTS

PA blockade with ETOH attenuated PAF-primed/fMLP-activated PMN elastase release in a dose-dependent manner. Exogenous PA8 reproduced maximally primed-activated PMN elastase release, and furthermore, PA8 was able to restore maximal elastase release following ethanol attenuation.

CONCLUSIONS

Elastase release from PAF-primed/ fMLP-activated neutrophils is dependent on PA production. Thus, PA production appears to be involved in both oxidant-dependent and independent mechanisms of neutrophil cytotoxicity and may be a potential therapeutic target in the treatment of hyperinflammatory diseases such as ARDS/MOF.

Human sulfite oxidase R160Q: identification of the mutation in a sulfite oxidase-deficient patient and expression and characterization of the mutant enzyme

Sulfite oxidase catalyzes the terminal reaction in the degradation of sulfur amino acids. Genetic deficiency of sulfite oxidase results in neurological abnormalities and often leads to death at an early age. The mutation in the sulfite oxidase gene responsible for sulfite oxidase deficiency in a 5-year-old girl was identified by sequence analysis of cDNA obtained from fibroblast mRNA to be a guanine to adenine transition at nucleotide 479 resulting in the amino acid substitution of Arg-160 to Gln. Recombinant protein containing the R160Q mutation was expressed in Escherichia coli, purified, and characterized. The mutant protein contained its full complement of molybdenum and heme, but exhibited 2% of native activity under standard assay conditions. Absorption spectroscopy of the isolated molybdenum domains of native sulfite oxidase and of the R160Q mutant showed significant differences in the 480- and 350-nm absorption bands, suggestive of altered geometry at the molybdenum center. Kinetic analysis of the R160Q protein showed an increase in Km for sulfite combined with a decrease in kcat resulting in a decrease of nearly 1,000-fold in the apparent second-order rate constant kcat/Km. Kinetic parameters for the in vitro generated R160K mutant were found to be intermediate in value between those of the native protein and the R160Q mutant. Native sulfite oxidase was rapidly inactivated by phenylglyoxal, yielding a modified protein with kinetic parameters mimicking those of the R160Q mutant. It is proposed that Arg-160 attracts the anionic substrate sulfite to the binding site near the molybdenum.

Impact of human immunodeficiency virus type-1 infection on the initial bacteriologic and radiographic manifestations of pulmonary tuberculosis in Uganda. Makerere University-Case Western Reserve University Research Collaboration

SETTING

TB Treatment Centre, Kampala, Uganda.

OBJECTIVE

To evaluate the impact of human immunodeficiency virus (HIV) co-infection on the bacteriologic and radiographic presentation of pulmonary tuberculosis (TB) in Uganda, a nation with high rates of Mycobacterium tuberculosis and HIV infection.

DESIGN

To compare baseline characteristics among HIV-infected and non-HIV-infected adults with initial newly-diagnosed episodes of culture-confirmed pulmonary TB screened for participation in a randomized prospective TB treatment trial.

RESULTS

Negative and paucibacillary (very scanty or scanty) sputum acid fast bacilli (AFB) smears were more frequent in HIV-infected patients presenting with pulmonary TB (P = 0.007). More HIV-infected individuals also had sputum cultures that required 7-8 weeks incubation until positivity than non-HIV-infected patients (P < 0.01). Lower lung field and diffuse pulmonary infiltrates were more frequent among HIV-infected patients. Rates of atypical X-ray presentations and cavitary disease were comparable between HIV-seropositive and -seronegative patients; however, atypical disease was more frequent in HIV-infected patients with small tuberculin reactions or tuberculin anergy (PPD = 0 mm).

CONCLUSION

HIV co-infection was associated with a higher frequency of negative and paucibacillary sputum AFB smears. The differences in the diagnostic yields of microscopy and culture between HIV-infected and non-HIV-infected individuals were small and do not, in our opinion, significantly affect the utility of these important diagnostic tests in developing countries. Examining more than one sputum specimen and monitoring cultured specimens for a full 8 weeks may assist in optimizing the diagnostic yield. Upper lobe infiltrates and cavitary disease are still the most frequent radiographic presentations of pulmonary TB in HIV-infected and non-HIV-infected adults in countries with a high prevalence of TB.

Activation of the leukocyte NADPH oxidase by phorbol ester requires the phosphorylation of p47PHOX on serine 303 or 304

The leukocyte NADPH oxidase is an enzyme in phagocytes and B lymphocytes that when activated catalyzes the production of O-2 from oxygen and NADPH. During oxidase activation, serine residues in the C-terminal quarter of the oxidase component p47(PHOX) become extensively phosphorylated, the protein acquiring as many as 9 phosphate residues. In a study of 11 p47(PHOX) mutants, each containing an alanine instead of a serine at a single potential phosphorylation site, we found that all but S379A corrected the defect in O-2 production in Epstein-Barr virus (EBV)-transformed p47(PHOX)-deficient B cells (Faust, L. P., El Benna, J., Babior, B. M., and Chanock, S. J. (1995) J. Clin. Invest. 96, 1499-1505). In particular, O-2 production was restored to these cells by the mutants S303A and S304A. Therefore, apart from serine 379, whose state of phosphorylation in the activated oxidase is unclear, no single potential phosphorylation site appeared to be essential for oxidase activation. We now report that the double mutant p47(PHOX) S303A/S304A was almost completely inactive when expressed in EBV-transformed p47(PHOX)-deficient B cells, even though it was expressed in normal amounts in the transfected cells and was able to translocate to the plasma membrane when the cells were stimulated. In contrast, the double mutant p47(PHOX) S303E/S304E was able to support high levels of O-2 production by EBV-transformed p47(PHOX)-deficient B cells. The surprising discovery that the double mutant S303K/S304K was also able to support considerable O-2 production suggests either that the effect of phosphorylation is related to the increase in hydrophilicity around serines 303 and 304 or that activation involves the formation of a metal bridge between the phosphorylated serines and another region of the protein.

Adenovirus-mediated gene transfer of the human TIMP-1 gene inhibits smooth muscle cell migration and neointimal formation in human saphenous vein

Neointimal formation involving smooth muscle cell (SMC) migration and proliferation is a common feature of atherosclerosis, restenosis after angioplasty, and vein graft intimal thickening. Extracellular matrix remodeling by metalloproteinase (MMP) enzymes is an essential component of neointimal formation and therefore MMPs are a potential target for localized gene therapy. To evaluate this concept using human tissue, we used the highly reproducible organ culture model of neointimal formation in human saphenous vein to investigate the effect of adenovirus-mediated gene transfer of tissue inhibitor of metalloproteinase 1 (TIMP-1) and the bacterial LacZ gene (RAd35) as a control. Incubating veins with 100 microl of RAd35 (1.2 x 10(10) pfu/ml) led to expression of LacZ in 39 +/- 7% of surface cells but had no effect on SMC proliferation, migration, or neointimal formation. Similar infection with RAdTIMP-1 increased explanation of TIMP-1 in surface cells and significantly inhibited neointimal formation and SMC migration after 14 days by 54% and 78%, respectively (n = 6, p < 0.05 Student's paired t test). No effect on SMC proliferation or deleterious effect on cell viability was observed. A specific MMP inhibitory effect was detected using in situ zymography. These data confirm the importance of MMPs in neointimal formation and highlight the potential for application of TIMP gene therapy.

Interleukin-6 augments neutrophil cytotoxic potential via selective enhancement of elastase release

BACKGROUND

Interleukin-6 (IL-6) appears to be a reliable marker of disease severity in critically ill patients at risk for inflammatory organ injury such as ARDS and MOF. Debate continues, however, as to whether this pleiotropic cytokine acts principally as a proinflammatory or counterregulatory mediator. Because the polymorphonuclear leukocyte (PMN) is a central effector of inflammatory injury, defining the effects of IL-6 on mechanisms of PMN cytotoxicity may be revealing. Previous investigations of PMN release of reactive oxygen species demonstrate that IL-6 in concert with other mediators may augment cytotoxicity. We hypothesized that IL-6 alone increases PMN cytotoxic potential through selective enhancement of elastase release.

MATERIALS AND METHODS

Isolated human PMNs were incubated with IL-6 in the physiologic range observed in critically ill patients (0.1 to 100 ng/ml) for 10 to 30 min. Selected cells were then activated with fMLP (1 microM). Elastase release was measured by specific cleavage of AAPV-pNA and compared to untreated cells and cells activated with formyl-Met-Leu-Phe (fMLP; 1 microM) alone. To determine if changes in elastase release might be due to IL-6 induced generation of PAF, WEB 2347 (50 microM) was preincubated with selected cells for 20 min. Surface expression of beta 2 integrins was measured by flow cytometry after incubating with labeled antibodies to CD11b and CD18.

RESULTS

IL-6 alone at 100 ng/ml augmented basal elastase release by 116 +/- 41% within 10 min. Doses as low as 0.1 ng/ml stimulated elastase release when the incubation time was increased to 30 min. After 30 min of incubation, IL-6 at all doses examined augmented the elastase release of fMLP-activated cells (increases of 33 to 45%). WEB 2347 preincubation did not block augmentation of elastase release by IL-6 at 10 ng/ml. IL-6 had no effect on surface expression of beta 2 integrins at 10 ng/ml.

CONCLUSIONS

IL-6 alone enhances both basal and fMLP-stimulated elastase release by PMNs. This proinflammatory action on PMNs may help explain the observed correlation between circulating IL-6 levels and inflammatory organ injury.

Plasma and lipids from stored packed red blood cells cause acute lung injury in an animal model

Transfusion-related acute lung injury (TRALI) is a serious complication of hemotherapy. During blood storage, lipids are generated and released into the plasma. In this study, the role of these lipids in TRALI was investigated using an isolated, perfused rat lung model. Rats were pretreated with endotoxin (LPS) or saline in vivo and the lungs were isolated, ventilated, and perfused with saline, or (a) 5% (vol/ vol) fresh human plasma, (b) plasma from stored blood from the day of isolation (D.0) or from the day of outdate (D.42), (c) lipid extracts from D.42 plasma, or (d) purified lysophosphatidylcholines. Lungs from saline or LPS-pretreated rats perfused with fresh (D.0) plasma showed no pulmonary damage as compared with saline perfused controls. LPS pretreatment/D.42 plasma perfusion caused acute lung injury (ALI) manifested by dramatic changes in both pulmonary artery pressure and edema. Incubation of LPS pre-tx rats with mibefradil, a Ca2+ channel blocker, or WEB 2170, a platelet-activating factor (PAF) receptor antagonist, inhibited ALI caused by D.42 plasma. Lung histology showed neutrophil sequestration without ALI with LPS pretreatment/saline or D.0 plasma perfusion, but ALI with LPS pretreatment/D.42 plasma perfusion, and inhibition of D.42 plasma induced ALI with WEB 2170 or mibefradil. A significant increase in leukotriene E4 was present in LPS-pretreated/D.42 plasma-perfused lungs that was inhibited by WEB 2170. Lastly, significant pulmonary edema was produced when lipid extracts of D.42 plasma or lysophosphatidylcholines were perfused into LPS-pretreated lungs. Lipids caused ALI without vasoconstriction, except at the highest dose employed. In conclusion, both plasma and lipids from stored blood produced pulmonary damage in a model of acute lung injury. TRALI, like the adult respiratory distress syndrome, may be the result of two insults: one derived from stored blood and the other from the clinical condition of the patient.

Hypertonic saline activates lipid-primed human neutrophils for enhanced elastase release

BACKGROUND

Ongoing clinical trials have revived interest in hypertonic saline (HTS) for postinjury resuscitation; these studies have documented serum Na+ concentrations > or = 170 mmol/L. Recent animal studies have shown that HTS enhances T-cell and monocyte function, but effects on the polymorphonuclear neutrophil (PMN) remain unclear. The postinjury lipid mediators platelet-activating factor (PAF) and leukotriene B4 (LTB4) have been implicated in PMN priming for cytotoxicity, which is believed to be important in the pathogenesis of multiple organ failure. We hypothesized that HTS would stimulate PMN superoxide (O2-) and elastase release from PAF- and LTB4-primed PMNs.

METHODS

Isolated PMNs from five donors were primed for 5 minutes with 200 nmol/L PAF or 1 micromol/L LTB4 in Kreb's-Ringer's phosphate with dextrose at a Na+ concentration of 140 mmol/L (normal serum Na+ concentration), pelleted, and resuspended in Kreb's-Ringer's phosphate with dextrose for 10 minutes at a Na+ concentration of 130 to 170 mmol/L. O2- generation was measured by superoxide dismutase-inhibitable reduction of cytochrome c and elastase release by cleavage of N-methoxysuccinyl-Ala-Ala-Pro-Val p-nitroanilide.

RESULTS

HTS with Na+ concentration up to 170 mmol/L had no significant effect on O2- production or elastase release from quiescent cells. Na+ concentration of 160 and 170 mmol/L, however, activated PAF- and LTB4-primed PMNs for enhanced elastase release with no effect on O2- production.

CONCLUSION

In clinically relevant concentrations, elevated Na+ activates lipid-primed neutrophils for enhanced elastase degranulation. Consequently, the administration of HTS in the early postinjury resuscitation period, when PMNs are maximally primed, may activate PMN elastase release and thereby promote the development of multiple organ failure.

Prostaglandin E1 attenuates cytotoxic mechanisms of primed neutrophils

In a recent clinical trial, liposomal prostaglandin E1 (PGE1) improved oxygenation, increased compliance, and decreased ventilator dependency in patients with adult respiratory distress syndrome (ARDS), thus renewing interest in PGE1 as a potential modulator of inflammation. The neutrophil (PMN) is believed to play a key role in the development of ARDS. Consequently, we investigated the effects of PGE1 on three components of the neutrophil inflammatory response: reactive oxygen species (ROS) generation, protease release, and surface expression of adhesion molecules. Human neutrophils were incubated with PGE1 and then primed with platelet-activating factor (PAF) and activation with N-formyl-methionyl-leucylphenylalanine (fMLP). PGE1 at a dose range of (10[-8] to 10[-5] M) attenuated primed/activated (PAF/fMLP) PMN superoxide anion generation and elastase release. In contrast, PGE1 doses > or =10[-5] M were required to attenuate PAF-stimulated neutrophil upregulation of CD11b/CD18 adhesion molecules. PGE1 also diminished the duration of the PAF-induced cytosolic calcium (Ca2+) flux. Our results suggest that plasma levels of PGE1 attained in patients with ARDS may attenuate ROS and protease neutrophil cytotoxicity but may not effectively block PMN-endothelial cell (EC) adhesion. This attenuation may occur through abrogation of the Ca2+ influx.

Examining emotional, physical, social, and spiritual health as determinants of self-rated health status

PURPOSE

To determine whether individuals' perceptions of their emotional, physical, social, and spiritual health constitute elements of their self-rated health status operationalized with a commonly employed single indicator.

DESIGN

Secondary analysis of cross-sectional survey data. Structural equation modeling with LISREL was used.

SETTING

The Yukon Health Promotion Survey, Yukon Territory, Canada, 1993.

SUBJECTS

The population-based sample was made up of 742 women and 713 men between 15 and 90 years of age; 80.3% responded.

MEASURES

Self-rated health status was operationalized with the "excellent, good, fair, poor" indicator derived from the question: "In general, compared to other people your age, would you say your health is...." Social, spiritual, emotional, and physical health status were also self-rated from excellent to poor.

RESULTS

The model's fit of the data was acceptable. Only physical health status significantly contributed to the variance in self-rated health status (55.1% of the variance was explained). Emotional, social, and spiritual health were found to have no effect on individuals' ratings of their health status.

CONCLUSIONS

Although recent conceptualizations have broadened in much of the theoretical and political discourse about health, especially in health promotion, the self-rated health status indicator measures only physical health status.

Clinically relevant concentrations of ethanol attenuate primed neutrophil bactericidal activity

BACKGROUND

Acute alcohol intoxication is associated with an increased risk of infection in the injured patient. The impact of clinically relevant levels of ethanol (ETOH) on neutrophil (PMN) bactericidal activity remains ill-defined. PMN priming optimizes microbicidal activity by enhancing oxygen radical production, degranulation, and adhesion molecule up-regulation. We hypothesized that clinically relevant levels of ETOH attenuate these primed PMN responses critical to eradicate infection.

METHODS

After incubation with ETOH (0-1.0%), isolated human PMNs were primed with beta-acetyl-gamma-O-alkyl and activated with N-formyl-methionyl-leucyl-phenylalanine. Superoxide generation was measured by cytochrome c reduction, elastase release was measured by cleavage of methoxysuccinyl-ala-ala-pro-val-p-nitroanilide, and CD11b was measured by fluorescent monoclonal antibody staining. Bactericidal activity was assessed by Staphylococcus aureus killing.

RESULTS

ETOH attenuated superoxide production dose-dependently with significance at 0.3% ETOH. Elastase release was attenuated starting at 0.2% ETOH, and CD11b expression was reduced starting at 0.4% ETOH. S. aureus killing was impaired dose-dependently with significance at 0.3% ETOH.

CONCLUSION

Clinically relevant concentrations of ETOH attenuate PMN functions critical in host defense against invading pathogens. These results provide direct in vitro evidence consistent with previous in vivo data that acute alcohol intoxication is important in the pathogenesis of trauma-related infections.

The leukocyte NADPH oxidase subunit p47PHOX: the role of the cysteine residues

The leukocyte NADPH oxidase is a multi-subunit enzyme that catalyzes the reduction of oxygen to O2- at the expense of a reduced pyridine nucleotide. We have used site-directed mutagenesis to examine the functional role of the four cysteines in p47PHOX, one of the subunits of the oxidase. For these experiments, mutant proteins in which a single cysteine was replaced with alanine were expressed in p47PHOX-deficient Epstein-Barr virus-transformed B lymphoblasts, and O2- production by these transfected cells was measured. The activity of the mutant C98A was similar to that of wild type, but the maximum rate of O2- production by C196A was significantly larger than seen with wild type. The other two mutants (i.e., C111A and C378A) differed from wild type not only in maximum O2- production, but also in the time required for activation, which was considerably delayed with both of these mutants. The similarity in the time courses of oxidase activation with the C111A and C378A mutants, and the finding that C378A occurs in the sequence CSE, raises the possibility that these cysteines may be involved in redox regulation of oxidase activity.

Air trapping in children: evaluation with dynamic lung densitometry with spiral CT

PURPOSE

To evaluate the feasibility of the use of a simple method of dynamic lung densitometry with spiral computed tomography (CT) to differentiate air trapping from compensatory hyperinflation in children.

MATERIALS AND METHODS

Eight children (mean age, 4 years 2 months) who had focal areas of radiolucency on chest radiographs underwent spiral CT (5-second acquisition time, fixed table position) during quiet breathing. Data were reconstructed with 0.7-second temporally overlapping scans. Lung attenuation in selected regions of interest was plotted against time.

RESULTS

In children with air trapping (n = 5), mean lung attenuation (+/- 1 standard deviation) in hyperlucent regions was -815 HU +/- 52, and mean respiratory excursion was 28 HU +/- 7. In patients with compensatory hyperinflation (n = 4), mean lung attenuation was -664 HU +/- 31, and respiratory excursion was 84 HU +/- 15. The differences were statistically significant (P = .001 for mean attenuation; P < .0005 for respiratory excursion).

CONCLUSION

Dynamic spiral CT lung densitometry is a quick, simple method for quantitative confirmation of the presence of air trapping and differentiation from compensatory hyperinflation.

Communicating cancer risk information: the challenges of uncertainty

Developments in predictive testing for inherited cancers have focused attention on the accurate and sensitive communication of risk information. Although sharing risk information is often equated with genetic testing, it is important to acknowledge that the need for risk information related to familial cancer is also relevant to those not eligible for, or interested in, testing. Communicating cancer risk information is germane to a number of health professions including physicians, geneticists, genetic counsellors, psychologists, nurses, health educators and social workers. Based on a literature review of 75 research reports, expert opinion papers and clinical protocols, we provide a synthesis of what is known about the communication of cancer risk information and make recommendations for the enhancement of knowledge and practice in the field.

Identification of critical IgG binding epitopes on the neonatal Fc receptor

The neonatal Fc receptor (FcRn) binds maternal immunoglobulin G (IgG) during the acquisition of passive immunity by the fetus or newborn. FcRn also binds IgG and returns it to the bloodstream, thus protecting IgG from a default degradative pathway. Biosensor assays have been used to characterize the interaction of a soluble form of rat FcRn with IgG, and demonstrate that FcRn dimerization and immobilization are necessary to reproduce in vivo binding characteristics. Here, we report the identification of several FcRn amino acid substitutions that disrupt its affinity for IgG and examine the effect of alteration of residues at the FcRn dimer interface. The role of these amino acids is discussed in the context of the previously reported structures of rat FcRn and a complex of FcRn with the Fc portion of IgG.

Biochemical and molecular biological characterization of CAC2, the Arabidopsis thaliana gene coding for the biotin carboxylase subunit of the plastidic acetyl-coenzyme A carboxylase

The biotin carboxylase subunit of the heteromeric chloroplastic acetyl-coenzyme A carboxylase (ACCase) of Arabidopsis thaliana is coded by a single gene (CAC2), which is interrupted by 15 introns. The cDNA encodes a deduced protein of 537 amino acids with an apparent N-terminal chloroplast-targeting transit peptide. Antibodies generated to a glutathione S-transferase-CAC2 fusion protein react solely with a 51-kD polypeptide of Arabidopsis; these antibodies also inhibit ACCase activity in extracts of Arabidopsis. The entire CAC2 cDNA sequence was expressed in Escherichia coli and the resulting recombinant biotin carboxylase was enzymatically active in carboxylating free biotin. The catalytic properties of the recombinant biotin carboxylase indicate that the activity of the heteromeric ACCase may be regulated by light-/dark-induced changes in stromal pH. The CAC2 gene is maximally expressed in organs and tissues that are actively synthesizing fatty acids for membrane lipids or oil deposition. The observed expression pattern of CAC2 mirrors that previously reported for the CAC1 gene (J.-K. Choi, F. Yu, E.S. Wurtele, B.J. Nikolau [1995] Plant Physiol 109: 619-625; J. Ke, J.-K. Choi, M. Smith, H.T. Horner, B.J. Nikolau, E.S. Wurtele [1997] Plant Physiol 113: 357-365), which codes for the biotin carboxyl carrier subunit of the heteromeric ACCase. This coordination is probably partially established by coordinate transcription of the two genes. This hypothesis is consistent with the finding that the CAC2 and CAC1 gene promoters share a common set of sequence motifs that may be important in guiding the transcription of these genes.

Dosimetric characteristics of a new high-intensity 192Ir source for remote afterloading

A new high-intensity 192Ir source has recently become commercially available for remote afterloading brachytherapy treatment. The dosimetric characteristics (dose rate constant, radial dose function, and anisotropy function) of this source were experimentally determined through the application of AAPM Task Group 43 recommendations. Complete dosimetric data are presented in this manuscript.

Activity of new quinolones against intracellular Mycobacterium avium in human monocytes

The ability to inhibit the in-vitro growth of mycobacteria within human monocytes is a useful screening assay for novel chemotherapeutic agents. In this study the MICs of a panel of new quinolones were determined by the broth microdilution method for two strains of Mycobacterium avium. Sixteen such compounds with MIC90s ranging from 2 to >32 mg/L were subsequently selected for the 7 day monocyte assay using ciprofloxacin for comparison. The degree of inhibition of intracellular growth correlated with the MICs. PD 139586, PD 143289, PD 135144, PD 119421 and PD 131575 were the most active new agents with activities superior to those of ciprofloxacin and sparfloxacin.

Newborn hearing screening in Hawaii

Hawaii has been a pioneer and national leader in implementing universal newborn hearing screening. In fact, Hawaii is one of only two states (Rhode Island is the other) which have a statewide newborn hearing screening program in which 95% or more of all newborns are screened. Hawaii is the best example of a truly integrated system of services to provide effective intervention for all infants and toddlers who are identified as having a hearing loss. The success of the newborn hearing screening program is measurable in two ways: 1) all available information indicates that not a single infant with hearing loss has been missed by the screening process and not a single infant has been misdiagnosed as having a hearing loss; and 2) many of the children identified with hearing loss by the newborn hearing screening program have transitioned out of the early intervention program with age-appropriate developmental and communication skills. The success of Hawaii's program is a tribute to the enthusiastic support and collaboration of legislators, pediatricians, hospital staff, and DOH personnel.

Is size discordancy an indication for delivery of preterm twins?

OBJECTIVE

Our goal was to determine the clinical significance of size discordancy in preterm twins.

STUDY DESIGN

A retrospective study was performed to review outcomes of twins delivered between Jan. 1, 1988, and June 30, 1995. Maternal and neonatal records were assessed for demographic data, maternal medical history, and neonatal mortality and morbidity outcomes. Discordancy was defined as > or = 20% difference in birth weight. The chi 2 analysis was performed.

RESULTS

There were 42 sets of discordant twins and 77 sets of concordant twins in the final analysis. The distribution of gestational ages in both groups was similar. We found no difference in maternal morbidity between the groups. Discordant sets had a significantly longer hospital stay (p = 0.003) and more cases of hyperbilirubinemia (p = 0.01), but there were no other differences in morbid outcomes. There were no differences in outcome variables between the two twins within discordant sets with respect to gender, size, birth order, growth restriction, or route of delivery. There were no stillbirths among any of the 238 infants. Of the 15 neonatal deaths, none occurred in infants delivered after 32 weeks' gestation or in infants weighing > 2000 gm at birth. Infants who were small for gestational age had a higher incidence of sepsis (p = 0.043) and longer hospital stays (p = 0.005) compared with infants who were appropriate for gestational age.

CONCLUSIONS

Size discordancy alone does not appear to be an indication for preterm delivery of twins. When results of antenatal testing are normal and growth restriction is absent, attempts should be made to achieve a gestational age > 32 weeks and weight > 2000 gm before delivery is considered.

Short-term exposure to thapsigargin inhibits neointima formation in human saphenous vein

Vascular smooth muscle cell (VSMC) migration and proliferation are involved in the intimal thickening responsible for late vein graft failure. In addition to growth and chemotactic factors, VSMCs require expression of matrix-degrading enzymes, e.g., metalloproteinases (MMP), to relieve the antiproliferative and antimigratory constraints of the extra-cellular matrix. Thapsigargin irreversibly inhibits Ca(2+)-ATPase, eliciting an increase in intracellular Ca2- and depletion of the intracellular calcium pools that are thought to be involved in the control of VSMC migration, VSMC proliferation, and MMP activity. We therefore studied the effect of thapsigargin on VSMC migration, VSMC proliferation, and MMP expression in human saphenous vein organ cultures. Vein segments were cultured for 14 days, and VSMC proliferation and migration were determined by autoradiography. Cell death was assessed using in situ end-labeling and lactate dehydrogenase release. Using Western blotting, we examined MMP-2 and MMP-9 and tissue inhibitor of metalloproteinases (TIMP)-1 and TIMP-2 expression. Exposure to thapsigargin at 10 nmol/L for 60 minutes before culture significantly inhibited neointimal thickening (60%, P < .05), intimal and medial VSMC proliferation (32%, P < .05 and 37%, P < .05, respectively), and VSMC migration (36%, P < .05). Thapsigargin at 10 nmol/L did not significantly increase cell death or MMP-2, MMP-9, TIMP-1, and TIMP-2 expression. These results suggest that blockade of Ca(2+)-ATPase by thapsigargin inhibits VSMC migration and proliferation involved in neointimal formation without affecting MMP-2 and MMP-9 expression. Because short-term exposure to thapsigargin was sufficient to inhibit neointima formation, this drug may prove useful in the treatment of intimal thickening after arterial bypass graft surgery.

Correlation between thoracic radiographic changes and remission/survival duration in 270 dogs with lymphosarcoma

A retrospective study was undertaken wherein the medical records and thoracic radiographs of 270 dogs with lymphosarcoma were reviewed to determine the type and frequency of thoracic radiographic changes. Statistical evaluation of the relationship between radiographic, clinical and immunologic factors and the primary remission duration and survival times was performed using univariate and multivariate analysis. One hundred ninety-two dogs (71%) had some type of thoracic radiographic abnormality, including 80 dogs (29.6%) with pulmonary infiltrates and 164 dogs (64.4%) with thoracic lymphadenomegaly. Only T-cell phenotype (p = 0.0056 for survival, p = 0.0045 for remission) and the presence of cranial mediastinal lymphadenomegaly (p = 0.0005 for survival, p = 0.0129 for remission) were identified as having a significant negative correlation to both primary remission and survival duration by multivariate analysis.

Failure of a two-state model to describe the influence of phospho(enol)pyruvate on phosphofructokinase from Escherichia coli

A linked-function analysis is presented of the influence of the inhibitor phospho(enol)pyruvate (PEP) on the binding of fructose 6-phosphate (Fru-6-P) and MgATP to phosphofructokinase (PFK) from Escherichia coli. The results of this analysis indicate that the previously described inhibition of Fru-6-P binding by MgATP [Johnson, J. L., & Reinhart, G. D. (1992) Biochemistry 31, 11510-11518] is almost completely independent of the inhibition by PEP. Moreover, with or without the presence of MgATP, the inhibition by PEP does not conform to the behavior expected if PEP and Fru-6-P bind exclusively to different enzyme forms since the formation of a ternary complex with both PEP and Fru-6-P bound is clearly evident at high concentrations of Fru-6-P and PEP. van't Hoff analyses of the coupling interactions between PEP and Fru-6-P in the presence and absence of MgATP indicate that these couplings are driven by enthalpy. However, the influence that PEP has on MgATP binding is small and changes from being activating to being inhibitory at temperatures above 40 degrees C, revealing the importance of a compensating entropy component to the coupling interactions. The four functionally defined enzyme forms that contribute to the coupling between Fru-6-P and PEP were evaluated structurally using the fluorescence properties of the single intrinsic tryptophan as a probe. The steady-state and dynamic fluorescence emission and polarization properties of the tryptophan, as well as its susceptibility to I- quenching, indicate that the flexibility of PFK in the vicinity of the tryptophan is perturbed by the binding of ligands. The properties of free PFK do not lie between those established by the binding of Fru-6-P and PEP individually, indicating that it is structurally distinct. The properties of the ternary complex lie between those of the singly-ligated forms. Though an equilibrium mixture of two conformations of ternary complex cannot therefore be formally ruled out, no evidence obtained to date requires the presumption of this mechanistic complication.

Risk factors for adverse drug reactions during thiacetazone treatment of pulmonary tuberculosis in human immunodeficiency virus infected adults

SETTING

Prospective randomised clinical trial comparing the safety and efficacy of rifampicin- and thiacetazone-containing regimens in human immunodeficiency virus (HIV)-infected adults with pulmonary tuberculosis (TB) at the National Tuberculosis Treatment Centre, Kampala, Uganda.

OBJECTIVE

To assess demographic, clinical and laboratory risk factors associated with toxicity during treatment with streptomycin, thiacetazone and isoniazid (STH) of HIV-1 infected adults with pulmonary TB.

DESIGN

Nested case-control study of all subjects randomized to the STH treatment arm. Baseline demographic, clinical, microbiological, hematological and radiographic characteristics were compared between subjects who developed and those who did not develop adverse drug reactions (ADR).

RESULTS

Of the 90 subjects randomized to STH, 13 developed ADR yielding an incidence rate of 19.6 events per 100 person years of observation (PYO). Eleven of the 13 ADR were cutaneous hypersensitivity reactions, including one fatal case of Stevens-Johnson syndrome. Eight of 13 patients who developed ADR were tuberculin anergic, compared to 12 of 77 patients who did not develop ADR (P < 0.001). An absolute lymphocyte count below 2000 cells/mm3 was also associated with ADR (P = 0.02).

CONCLUSION

Initial anergy to tuberculin and lymphocytopenia, markers of advanced HIV infection and immunosuppression, were associated with increased risk for adverse drug reactions during STH chemotherapy.

Gut and liver fat metabolism in depancreatized dogs: effects of exercise and acute insulin infusion

Excessive circulating fat levels are a defining feature of poor metabolic control in diabetes. Splanchnic adipose tissue is a source of free fatty acids (FFA), and the liver is a key site of FFA utilization and the sole source of ketones. Despite the role of splanchnic tissues in fat metabolism, little is known about how these tissues respond to diabetes under divergent metabolic conditions. Therefore, splanchnic fat metabolism was studied in poorly controlled diabetes under two conditions. First, it was studied during exercise, a stimulus that enhances FFA flux. Second, it was studied while insulin was being acutely infused to achieve levels normally present during exercise, a treatment that may be expected to inhibit lipolysis. For this purpose, liver and gut arteriovenous differences were used during rest and 2.5 h of treadmill exercise in insulin-deficient (n = 6) and acutely insulin-infused (n = 4) depancreatized (PX) dogs. The data show that 1) exercise, in insulin-deficient PX dogs, leads to an increase in net FFA release from mesenteric fat that is equal in magnitude to the response in nondiabetic dogs; 2) net hepatic fractional FFA extraction is increased twofold during exercise in both insulin-deficient PX dogs and nondiabetic control dogs; 3) during exercise, approximately 40 and 75% of the FFA consumed by the liver is effectively transferred from fat stores mobilized from splanchnic adipose tissue in insulin-deficient PX and nondiabetic dogs, respectively; 4) hepatic ketogenic efficiency is elevated during rest three- to fourfold in insulin-deficient PX dogs compared with nondiabetic control dogs and remains elevated during exercise; and 5) surprisingly, acute insulin replacement is ineffective in normalizing net gut, hepatic, or splanchnic FFA or ketone body balances in PX dogs.

Phase II trial of docetaxel in non-Hodgkin's lymphomas: a study of the Cancer and Leukemia Group B

PURPOSE

To evaluate the new anticancer agent, docetaxel, with a novel mechanism of action in patients with non-Hodgkin's lymphoma International Working Formulation (IWF) A through H, to determine the response rate by histologic group and the toxicities of this agent in this population.

PATIENTS AND METHODS

Sixty-eight patients previously treated for non-Hodgkin's lymphoma with two prior cytotoxic regimens for low-grade and one prior regimen for intermediate-grade lymphoma were entered onto this phase II trial. Central pathologic review was required. Twenty-four IWF A to C and 31 IWF D to H patients with normal hepatic and renal function, performance status (PS) 0 to 2, and adequate hematologic function were eligible. Patients received docetaxel 100 mg/m2 intravenously over 1 hour without corticosteroid premedications every 3 weeks with weekly hematologic monitoring, and tumor assessment every 3 weeks. For grade 3 or 4 hematologic toxicity, the docetaxel dosage was lowered to 75 mg/m2. Patients received a maximum of six cycles of therapy.

RESULTS

The major response rate was 13% (95% confidence limits, 3% to 32%) for IWF A to C and 16% (95% confidence limits, 5% to 34%) for IWF D to H; response durations ranged from 1.4 to 20 months. Time to response ranged from 1.3 to 2.8 months. Patients refractory to previous chemotherapy were less apt to respond to docetaxel, but the differences were not statistically different in this small sample size. Twelve percent of IWF A to C and 6% of IWF D to H patients discontinued treatment because of toxicity. The major toxicity was granulocytopenia (grade 3 to 4), which occurred in virtually all patients during the first course of therapy.

CONCLUSION

This study confirms that docetaxel has limited but definite activity in patients with non-Hodgkin's lymphoma and suggests that the previously reported responses with taxanes can not be attributed solely to the use of corticosteroid premedications.

Risk factors for relapse in human immunodeficiency virus type 1 infected adults with pulmonary tuberculosis

SETTING

A study conducted by the Uganda-Case Western Reserve University Research Collaboration in Kampala, Uganda, a country with high incidence rates of tuberculosis (TB) and human immunodeficiency virus type 1 (HIV-1) infection.

OBJECTIVE

To assess clinical, microbiologic and radiographic factors associated with risk for relapse in HIV-infected adults treated for initial episodes of pulmonary TB.

DESIGN

Nested case-control study within a randomized prospective clinical trial comparing the safety and efficacy of thiacetazone- and rifampicin-containing regimens for TB treatment in HIV-infected adults.

RESULTS

The analysis was based on 119 patients who completed therapy. Median follow-up for all subjects was 22.3 months. Ten patients relapsed a median of 12.7 months after the end of therapy; seven of these were initially treated with the thiacetazone (T)-containing regimen. Each relapse case was matched to four controls by length of follow-up after initial TB treatment. In a univariate analysis risk for relapse was associated with treatment with the T-containing regimen (OR = 4.2, P = 0.08), age > or = 30 yrs (OR = 2.9, P = 0.16), and irregular compliance (OR = 3.6, P = 0.1). Baseline anergy on Mantoux tuberculin skin testing, cavitary disease, radiographic extent of disease and sputum bacillary burden, two month culture negativity, and residual cavitary disease at the end of treatment did not differ between relapses and controls.

CONCLUSION

Older HIV-1 infected patients, those with poor treatment compliance, and those being treated with T-containing regimens, may be at increased risk for relapse after TB treatment and require closer post-treatment surveillance. Risk for relapse in HIV-infected adults with pulmonary TB after treatment with a nine month rifampicin-containing regimen was low (3.1 per 100 person-years observation) compared with those treated with a thiacetazone-containing regimen (10.1 per 100 person-years observation).

A trial of three regimens to prevent tuberculosis in Ugandan adults infected with the human immunodeficiency virus. Uganda-Case Western Reserve University Research Collaboration

BACKGROUND

Infection with the human immunodeficiency virus (HIV) greatly increases the risk of reactivation tuberculosis. We evaluated the safety and efficacy of three preventive-therapy regimens in a setting where exposure to tuberculosis is common.

METHODS

We performed a randomized, placebo-controlled trial in 2736 HIV-infected adults recruited in Kampala, Uganda. Subjects with positive tuberculin skin tests (induration, > or =5 mm) with purified protein derivative (PPD) were randomly assigned to one of four regimens: placebo (464 subjects), isoniazid daily for six months (536), isoniazid and rifampin daily for three months (556), or isoniazid, rifampin, and pyrazinamide daily for three months (462). Subjects with anergy (0 mm induration in reaction to PPD and candida antigens) were randomly assigned to receive either placebo (323 subjects) or six months of isoniazid (395). The medications were dispensed monthly and were self-administered.

RESULTS

Among the PPD-positive subjects, the incidence of tuberculosis in the three groups that received preventive therapy was lower than the rate in the placebo group (P=0.002 by the log-rank test). The relative risk of tuberculosis with isoniazid alone, as compared with placebo, was 0.33 (95 percent confidence interval, 0.14 to 0.77); with isoniazid and rifampin, 0.40 (0.18 to 0.86); and with isoniazid, rifampin, and pyrazinamide, 0.51 (0.24 to 1.08). Among the subjects with anergy, the relative risk of tuberculosis was 0.83 (95 percent confidence interval, 0.34 to 2.04) with isoniazid as compared with placebo. Side effects were more common with the multidrug regimens, and particularly with the regimen containing pyrazinamide. Survival did not differ among the groups, but the subjects with anergy had a higher mortality rate than the PPD-positive subjects.

CONCLUSIONS

A six-month course of isoniazid confers short-term protection against tuberculosis among PPD-positive, HIV-infected adults. Multidrug regimens with isoniazid and rifampin taken for three months also reduce the risk of tuberculosis.

Altered IL-1 expression and compartmentalization in monocytes from patients with AIDS stimulated with Mycobacterium avium complex

The pathophysiologic basis for the exuberant intracellular growth of Mycobacterium avium complex (MAC) in AIDS patients is unclear but may relate to altered expression of modulatory cytokines. Interleukin (IL)-1, IL-6, and TNF-alpha expression by monocytes from AIDS patients and healthy subjects (HS) stimulated with isogeneic MAC strains (SmT, smooth-transparent, virulent; SmD, smooth-domed, avirulent) was examined. Spontaneous cytokine production was not observed in patients with AIDS. MAC strains induced less IL-1 alpha and IL-1 beta release in AIDS patients than HS (P < 0.05). The ratio of cell-associated to supernatant IL-1 alpha also was increased in AIDS patients (P = 0.03). IL-1 beta mRNA expression paralleled protein release in either group of subjects. In both HS and AIDS patients, stimulation with SmD induced more IL-1 and TNF-alpha release by monocytes compared to SmT. In AIDS patients, SmD also induced greater IL-6 release than SmT (P < 0.01). Alterations in monocyte expression and compartmentalization of the regulatory cytokines IL-1 and IL-6 may enhance bacterial replication and contribute to the pathogenesis of MAC infection in AIDS.

The challenges of clinical nursing research: strategies for successful conduct

Although the literature is replete with stringent methodological guidelines for designing experimental and quasi-experimental studies, there is a paucity of literature addressing the challenges of conducting these studies in the "real world" of the clinical setting. This article describes the challenges experienced by a team of researchers conducting a study in the acute care setting, including those associated with navigating organizational restructuring and managing within a climate of uncertainty. The study focused on the evaluation of a nurse-delivered smoking cessation intervention for hospitalized cardiac patients. As each particular challenge emerged, strategies were developed. By explicating these challenges and strategies, we hope to help clinical researchers deal with challenges proactively rather than reactively.

HIV-1 risk and vaccine acceptability in the Ugandan military

Between July and October 1993, 570 19- to 22-year-old volunteers were screened for HIV-1, with a resulting seroprevalence rate of 18.3% (95% CI: 14.0%, 22.6%). A cohort of 249 HIV-1-noninfected military recruits in the Ugandan Peoples' Defense Forces was followed prospectively for up to 18 months to document rates of HIV-1 seroprevalence, seroconversion, and knowledge and attitudes related to vaccine acceptability. The HIV-1 seroincidence rate was 3.56 per 100 person-years (95% CI: 1.49, 5.62) over 309 person-years of observation. At the 3- and 12-month visits, subjects were interviewed on issues of acceptance and knowledge about vaccines, including anti-HIV vaccines in particular. More than 90% believe that HIV vaccines will not cause HIV infection, and if offered, 88% report that they would take the vaccine if they were not already infected. Nonvaccine prevention methods were considered less reliable; monogamy and condom use were considered effective by only 33.5% and 69.3% of the cohort respectively. After completing the vaccine acceptability questionnaire at the 12-month visit, subjects were offered an approved polyvalent meningococcal vaccine as an indicator of general vaccine acceptance. All subjects reported receiving at least one previous vaccination, and 95% willingly accepted the meningococcal vaccination. The Ugandan military is a stable population at substantial risk for HIV-1 infection and may be a suitable population for vaccine efficacy trials.

Homocyst(e)ine decreases bioavailable nitric oxide by a mechanism involving glutathione peroxidase

Hyperhomocyst(e)inemia is believed to injure endothelial cells in vivo through a number of mechanisms, including the generation of hydrogen peroxide (H2O2). Earlier in vitro studies demonstrated that homocyst(e)ine (Hcy) decreases the biological activity of endothelium-derived relaxing factor and that this decrease can be reversed by preventing the generation of hydrogen peroxide. Here we show that Hcy treatment of bovine aortic endothelial cells leads to a dose-dependent decrease in NOx (p = 0.001 by one-way analysis of variance) independent of endothelial nitric-oxide synthase activity or protein levels and nos3 transcription, suggesting that Hcy affects the bioavailability of NO, not its production. We hypothesized that, in addition to increasing the generation of H2O2, Hcy decreases the cell's ability to detoxify H2O2 by impairing intracellular antioxidant enzymes, specifically the intracellular isoform of glutathione peroxidase (GPx). To test this hypothesis, confluent bovine aortic endothelial cells were treated with a range of concentrations of Hcy, and intracellular GPx activity was determined. Compared with control cells, cells treated with Hcy showed a significant reduction in GPx activity (up to 81% at 250 microM Hcy). In parallel with the decrease in GPx activity, steady-state GPx mRNA levels were also significantly decreased compared with control levels after exposure to Hcy, which appeared not to be a consequence of message destabilization. These data suggest a novel mechanism by which Hcy, in addition to increasing the generation of hydrogen peroxide, may selectively impair the endothelial cell's ability to detoxify H2O2, thus rendering NO more susceptible to oxidative inactivation.

Simple ovarian cysts. Clinical features on a first-trimester ultrasound scan

OBJECTIVE

To determine the clinical features of simple ovarian cysts, often seen on a first-trimester ultrasound scan.

STUDY DESIGN

All initial examinations from patients scanned in 1993 (N = 1,001) were reviewed, and the clinical features of simple ovarian cysts were determined. Relationships were determined between the presence of a cyst and first-trimester pregnancy outcomes, including progression beyond the first trimester, blighted ovum, ectopic pregnancy and fetal demise.

RESULTS

A simple ovarian cyst was observed in 29% of patients. Cysts were seen less often after 8 weeks' gestation, and there was an equal distribution between those on the right and those on the left side of the pelvis. Cyst diameters did not vary with gestational age, and most mean diameters were within a range of 1-3 cm. The absence of a cyst was more often associated with a blighted ovum on follow-up ultrasound scan (relative risk, 2.8), but its presence or absence did not correlate with failure to progress beyond the first trimester, ectopic pregnancy or intrauterine fetal demise.

CONCLUSION

The presence of simple ovarian cysts in the first trimester, which may represent corpus luteal cysts, appears to support early pregnancy development due to its association with a lower incidence of blighted ova.

Cultures of "Clostridium acetobutylicum" from various collections comprise Clostridium acetobutylicum, Clostridium beijerinckii, and two other distinct types based on DNA-DNA reassociation

The best-known acetone-butanol (solvent)-producing bacterium is the Weizmann organism, Clostridium acetobutylicum, which was used for starch-based industrial fermentation. In the past two decades, cultures of "C. acetobutylicum" from various culture collections have included organisms that were isolated for sugar (molasses)-based industrial solvent production. Recent biochemical and genetic studies have revealed significant differences among some of these "C. acetobutylicum" strains. We used DNA-DNA reassociation to analyze 39 cultures of "C. acetobutylicum" and phenotypically similar organisms from major collections. The results of this study clearly identified four groups intergroup reassociation values of less than 30%. All of the intragroup values except the value for one strain were 68% or more, which supported species status for each group. The C. acetobutylicum group (with ATCC 824 as the type strain) consisted of 17 cultures and had average reassociation values of 10% with the other three groups. All strains of C. acetobutylicum produced riboflavin in milk, and the cultures were bright yellow, which is useful for differentiating this species from the other three groups. The Clostridium beijerinckii group (with VPI 5481 [= ATCC 25752] as the type strain) consisted of 16 cultures and included strains NCIMB 8052 and NCP 270. Strains NCP 262 and NRRL B643 constituted the third group, whereas strain N1-4 ("Clostridium saccharoperbutylacetonicum") and its derivative, strain N1-4081, formed the fourth group. At present, the last two groups are each represented by only one independent strain; definitive descriptions of these two groups as two new or revived species will require further phenotypic characterization, as well as identification of additional strains. C. beijerinckii NCP 270, Clostridium sp. strain NRRL B643, and "C. saccharoperbutylacetonicum" were used in industrial solvent production from molasses, which confirms that the new organisms used for the sugar-based processes are distinct from C. acetobutylicum.

High incidence of Kaposi's sarcoma-associated herpesvirus and Epstein-Barr virus in tumor lesions and peripheral blood mononuclear cells from patients with Kaposi's sarcoma in Uganda

With the advent of AIDS, Kaposi's sarcoma (KS) has become one of the leading malignancies in sub-Saharan Africa. Recently, DNA sequences from a new human herpesvirus called KS-associated herpesvirus (KSHV) or human herpesvirus type 8 have been found in KS tumor lesions in high frequency. Analyses of tumor lesions from 38 Ugandan KS patients indicated a uniform presence of KSHV in KS tumor lesions as revealed by polymerase chain reaction and Southern hybridization. In contrast, only 31% (11/36) of the normal skin biopsies from the same patient population were positive. The frequency of KSHV DNA detection in peripheral blood mononuclear cells (PBMC) of KS patients was also high (84%, 31/37). Similar analyses revealed the presence of cytomegalovirus (21% in KS lesions) to be discordant with KS development. A large number of KS lesions (87%, 33/38) and KS PBMC (70%, 26/37) were, however, positive for Epstein-Barr virus sequences. In addition, KSHV DNA was not found in the PBMC of Ugandans without KS.

Transcriptional analysis of the toxigenic element of Clostridium difficile

A transcriptional analysis was undertaken for the toxigenic element of Clostridium difficile in five strains which differ greatly in toxigenicity. The toxigenic element has recently been described in C. difficile strain VPI 10463 and consists of three small open reading frames in addition to the toxin A and B genes. A large, polycistronic transcript (17.5 kb) was detected, in addition to processing intermediates, and individual transcripts for toxin A, toxin B, and two of the three small open reading frames. A transcription initiation site and a promoter for the toxigenic element were identified, as well as major extension products upstream of the toxin A and B genes. These data support models in which the toxin A and B genes are cotranscribed along with the open reading frames, in addition to being transcribed individually. Transcriptional analyses, using probes for the transcripts for toxin A and toxin B, revealed quantitative differences among strains which correlated with quantitative differences in toxin production among these strains. However, DNA sequencing of intergenic regions in these strains showed remarkable DNA sequence conservation in these intergenic regions.

Relationship of organizational characteristics of Canadian workplaces to anti-smoking initiatives

BACKGROUND

In Canada, with universal single-payer health care insurance and a lower proportion of the gross domestic product going to health care costs, employers may be less motivated than their U.S. counterparts to develop health promotion programs for their employees. This study determined the extent to which nongovernmental workplaces in Canada have made smoking-related information, policies, and programs available to their employees. Several characteristics of those workplaces most likely to have engaged in such activities were identified.

METHODS

A secondary analysis of data collected in the 1992 National Workplace Survey was conducted. All Canadian provinces, except Saskatchewan, were included. Dunn and Bradstreet's register of companies was used to select companies randomly from those with 20 or more employees. Questionnaires were distributed to 10000 workplaces. The response rate was 35.5% (N = 3,549). There were no significant differences found between responders and nonresponders in a phone survey.

RESULTS

One-half of workplaces reported some kind of smoking-related initiative. Most of the initiatives were smoking policies; only 11.7% of workplaces provided smoking cessation programs. The number of employees and the number of other lifestyle and occupational health and safety programs available are most predictive of smoking-related programs.

CONCLUSIONS

If Canadians are going to achieve a smoke-free society, greater efforts to assist smokers to quit will be necessary. The workplace provides an excellent opportunity for such efforts. Health promotion advocates must communicate the cost savings and other benefits to employers garnered from workplace smoking reduction efforts.

Members of the nuclear receptor superfamily regulate transcription from the hepatitis B virus nucleocapsid promoter

The role of members of the nuclear receptor superfamily of transcription factors in regulating hepatitis B virus (HBV) transcription was investigated. Hepatocyte nuclear factor 4 (HNF4), the retinoid X receptor (RXR), and the peroxisome proliferator-activated receptor (PPAR) were examined for their capacity to modulate the level of transcriptional activity from the four HBV promoters by transient-transfection analysis in the dedifferentiated hepatoma cell line, HepG2.1. It was found that the nucleocapsid and large surface antigen promoters were transactivated in the presence of HNF4 whereas the enhancer I/X gene, nucleocapsid, and large surface antigen promoters were transactivated in the presence of RXR and PPAR. Characterization of the nuclear receptors interacting with the nucleocapsid promoter region demonstrated that HNF4 is the primary transcription factor binding to the regulatory region spanning nucleotides -127 to -102 whereas HNF4, RXR-PPAR heterodimers, COUPTF1, and ARP1 bind the regulatory region spanning nucleotides -34 to -7. Transcriptional transactivation from the nucleocapsid promoter by HNF4 appears to be mediated through the two HNF4 binding sites in the promoter, whereas modulation of the level of transcription from the nucleocapsid promoter by RXR-PPAR appears to be regulated by the regulatory sequence element spanning nucleotides -34 to -7 and the HBV enhancer 1 region. These observations indicate that HBV transcription, and pregenomic RNA synthesis in particular, is regulated by ligand-dependent nuclear receptors. Agonists and antagonists capable of regulating the activity of these nuclear receptors may permit the modulation of HBV transcription and consequently replication during viral infection.

The effect of warning on malingering on memory and motor tasks in college samples

The effect of a warning regarding detection of simulated cognitive and motor deficits on the Wechsler Memory Scale-Revised (WMS-R; Wechsler, 1987) and Grooved Pegboard (Klove, 1963; Matthews & Klove, 1964) was examined. Undergraduates (N = 87) were randomly assigned to one of three conditions: simulators without warning, simulators with warning, and controls. It was predicted that warning participants that simulation efforts will be detected would reduce malingering behavior and this hypothesis was generally supported. Analyses indicated simulators with warning frequently approximated control group performances and were significantly better than simulators without warning on some measures. Stepwise discriminant function analysis accurately classified 57% of all participants. Results provide support for effectiveness of warning in reducing malingering behavior on selected measures and are discussed in terms of the use of warning as an adjunct to existing procedures, role of the neuropsychologist, and informed consent for assessment in personal injury litigation.

Two-step tuberculin skin testing in HIV-infected persons in Uganda

Identifying persons infected with both human immunodeficiency virus (HIV) and Mycobacterium tuberculosis (MTB) is often difficult because of the reduced sensitivity of tuberculin skin testing in HIV-infected persons. To determine the value of two-step tuberculin skin testing (TTST) as a method of increasing the sensitivity of tuberculin skin testing in HIV-infected persons, a consecutive sample of 58 HIV-infected persons being screened for a TB preventive therapy trial in Uganda with an initial purified protein derivative (PPD) response < 5 mm completed two-step tuberculin and candida skin testing. The mean change in PPD size between the two tests, placed a mean of 8 d apart, was +2.1 mm (SD 4.4 mm, range -4 to +16 mm). Seventeen subjects (29%) had a boosted response (PPD1 < 5 and PPD2 > or = 5). In a multiple logistic regression model, boosted responses were independently associated with a CD4 count between 200 and 500 microl(-1) (p = 0.02) and a higher body mass index (p = 0.05). TTST may be valuable in identifying MTB infection and in preventing misclassification of boosted responses as skin test conversions in HIV-infected persons, especially persons with CD4 counts between 200 and 500 microl(-1) from areas with a high prevalence of MTB infection or from areas with a low prevalence of MTB infection who have other risk factors for MTB infection.

Systemic lupus erythematosus with acanthosis nigricans, hyperpigmentation, and insulin receptor antibody

Acanthosis nigricans, insulin receptor antibody, and systemic lupus erythematosus are associated in the potentially lethal syndrome of type B insulin resistance. Hyperpigmentation has been reported rarely, while glucose intolerance is common in these patients. We report an adolescent girl with acanthosis nigricans, hyperpigmentation, insulin receptor antibody, and systemic lupus erythematosus without glucose intolerance. Insulin resistance may be mild or transient in some patients with type B insulin resistance. Resolution of skin lesions was noted during therapy of SLE, and was associated with disappearance of insulin receptor antibody.

A critical analysis of COA research

Five experts respected for their significant contributions to the scientific literature on children of alcoholics (COA's) offer their perspectives in a panel discussion format. The panel members reflect on the historical roots of COA research and comment on its current status and future direction. Enriched by the panelists' variety of backgrounds, research interests, and approaches, the discussion emphasizes the need to consider multiple variables that influence the risk for alcoholism among COA's.

Immune activation, allergic drug toxicity and mortality in HIV-positive tuberculosis

SETTING

Tuberculosis Treatment Center, Kampala, Uganda.

OBJECTIVE

HIV-1 affects outcome in pulmonary tuberculosis (TB). Immune mechanisms triggered by Mycobacterium tuberculosis may lead to increased HIV expression and accelerated disease progression. This study was conducted to correlate serum levels of markers of immune activation with mortality and drug toxicity in HIV + TB.

DESIGN

Substudy of a randomized clinical trial of streptomycin-thiacetazone-isoniazid (STH) vs. rifampin-isoniazid-pyrazinamide (RHZ) in HIV + TB.

RESULTS

Neopterin > or = 14 ng/ml, TNF-alpha receptors > or = 6.5 ng/ml, and negative skin test were independently associated with increased mortality (P < 0.01). Among STH-treated subjects, dermatologic toxicity and mortality were respectively 13- and 6.3-fold more likely to occur in subjects with elevated neopterin (P < 0.05), although these two adverse events occurred independently. Activation markers increased from baseline after 2 months of therapy with the less rapidly bactericidal STH regimen, whereas they declined in those treated with RHZ, suggesting a relationship with continued mycobacterial replication.

CONCLUSIONS

Immune activation in HIV + TB is associated with shortened survival and increased risk of drug toxicity. HIV + TB patients with elevated serum neopterin should be treated with a rapidly-bactericidal drug regimen which does not include thiacetazone.

Identification of mutations contributing to the reduced virulence of a modified strain of respiratory syncytial virus

The nucleotide sequences of the genome of the RSS-2 wild type strain of respiratory syncytial (RS) virus, which is known to induce upper respiratory tract infection in adults, and that of the attenuated ts1C candidate vaccine derived from it by three cycles of mutagenesis and selection of temperature-sensitive (ts) mutants, have been determined. Comparison of the sequences has located the genetic changes which contribute to the reduced pathogenicity in adults of the candidate vaccine. Thirty-seven nucleotide changes distinguish the wild type and ts1C, 13 of which confer amino acid substitutions; no mutations are present in extragenic regions. Partial nucleotide sequencing of the genomes of the first stage ts mutant (ts1A) and the second stage ts mutant (ts1B), which were intermediates in the derivation of the third stage mutant ts1C, established that five mutations resulting in amino acid substitutions had been induced in the first cycle of mutagenesis, one in the second cycle, and seven in the third cycle. The unique mutation differentiating ts1B from ts1A substitutes an alanine for a threonine at residue 736 in the polymerase (L) protein. The occurrence of a mutation in ts1C inducing substitution of a phenylalanine for a serine residue at an adjacent site (731) suggests that mutations in this region of the polymerase can have significant attenuating effects. The data suggest also that a mutation in the F gene may contribute to the attenuated phenotype.

Isolated sulfite oxidase deficiency

Isolated sulfite oxidase (SO) deficiency is an autosomal recessively inherited inborn error of sulfur metabolism. In this report of a ninth patient the clinical history, laboratory results, neuropathological findings and a mutation in the sulfite oxidase gene are described. The data from this patient and previously published patients with isolated sulfite oxidase deficiency and molybdenum cofactor deficiency are summarized to characterize this rare disorder. The patient presented neonatally with intractable seizures and did not progress developmentally beyond the neonatal stage. Dislocated lenses were apparent at 2 months. There was increased urine excretion of sulfite and S-sulfocysteine and a decreased concentration of plasma cystine. A lactic acidemia was present for 6 months. Liver sulfite oxidase activity was not detectable but xanthine dehydrogenase activity was normal. The boy died of respiratory failure at 32 months. Neuropathological findings of cortical necrosis and extensive cavitating leukoencephalopathy were reminiscent of those seen in severe perinatal asphyxia suggesting an etiology of energy deficiency. A point mutation that resulted in a truncated protein missing the molybdenum-binding site has been identified.