A conserved family of immune effectors cleaves cellular ATP upon viral infection

During viral infection, cells can deploy immune strategies that deprive viruses of molecules essential for their replication. Here, we report a family of immune effectors in bacteria that, upon phage infection, degrade cellular adenosine triphosphate (ATP) and deoxyadenosine triphosphate (dATP) by cleaving the N-glycosidic bond between the adenine and sugar moieties. These ATP nucleosidase effectors are widely distributed within multiple bacterial defense systems, including cyclic oligonucleotide-based antiviral signaling systems (CBASS), prokaryotic argonautes, and nucleotide-binding leucine-rich repeat (NLR)-like proteins, and we show that ATP and dATP degradation during infection halts phage propagation. By analyzing homologs of the immune ATP nucleosidase domain, we discover and characterize Detocs, a family of bacterial defense systems with a two-component phosphotransfer-signaling architecture. The immune ATP nucleosidase domain is also encoded within diverse eukaryotic proteins with immune-like architectures, and we show biochemically that eukaryotic homologs preserve the ATP nucleosidase activity. Our findings suggest that ATP and dATP degradation is a cell-autonomous innate immune strategy conserved across the tree of life.

Discovery of phage determinants that confer sensitivity to bacterial immune systems

Over the past few years, numerous anti-phage defense systems have been discovered in bacteria. Although the mechanism of defense for some of these systems is understood, a major unanswered question is how these systems sense phage infection. To systematically address this question, we isolated 177 phage mutants that escape 15 different defense systems. In many cases, these escaper phages were mutated in the gene sensed by the defense system, enabling us to map the phage determinants that confer sensitivity to bacterial immunity. Our data identify specificity determinants of diverse retron systems and reveal phage-encoded triggers for multiple abortive infection systems. We find general themes in phage sensing and demonstrate that mechanistically diverse systems have converged to sense either the core replication machinery of the phage, phage structural components, or host takeover mechanisms. Combining our data with previous findings, we formulate key principles on how bacterial immune systems sense phage invaders.

Cryo-EM structure of the RADAR supramolecular anti-phage defense complex

RADAR is a two-protein bacterial defense system that was reported to defend against phage by "editing" messenger RNA. Here, we determine cryo-EM structures of the RADAR defense complex, revealing RdrA as a heptameric, two-layered AAA+ ATPase and RdrB as a dodecameric, hollow complex with twelve surface-exposed deaminase active sites. RdrA and RdrB join to form a giant assembly up to 10 MDa, with RdrA docked as a funnel over the RdrB active site. Surprisingly, our structures reveal an RdrB active site that targets mononucleotides. We show that RdrB catalyzes ATP-to-ITP conversion in vitro and induces the massive accumulation of inosine mononucleotides during phage infection in vivo, limiting phage replication. Our results define ATP mononucleotide deamination as a determinant of RADAR immunity and reveal supramolecular assembly of a nucleotide-modifying machine as a mechanism of anti-phage defense.

Multiple phage resistance systems inhibit infection via SIR2-dependent NAD+ depletion

Defence-associated sirtuins (DSRs) comprise a family of proteins that defend bacteria from phage infection via an unknown mechanism. These proteins are common in bacteria and harbour an N-terminal sirtuin (SIR2) domain. In this study we report that DSR proteins degrade nicotinamide adenine dinucleotide (NAD⁺) during infection, depleting the cell of this essential molecule and aborting phage propagation. Our data show that one of these proteins, DSR2, directly identifies phage tail tube proteins and then becomes an active NADase in Bacillus subtilis. Using a phage mating methodology that promotes genetic exchange between pairs of DSR2-sensitive and DSR2-resistant phages, we further show that some phages express anti-DSR2 proteins that bind and repress DSR2. Finally, we demonstrate that the SIR2 domain serves as an effector NADase in a diverse set of phage defence systems outside the DSR family. Our results establish the general role of SIR2 domains in bacterial immunity against phages.

Prokaryotic viperins produce diverse antiviral molecules

Viperin is an interferon-induced cellular protein that is conserved in animals1. It has previously been shown to inhibit the replication of multiple viruses by producing the ribonucleotide 3'-deoxy-3',4'-didehydro (ddh)-cytidine triphosphate (ddhCTP), which acts as a chain terminator for viral RNA polymerase2. Here we show that eukaryotic viperin originated from a clade of bacterial and archaeal proteins that protect against phage infection. Prokaryotic viperins produce a set of modified ribonucleotides that include ddhCTP, ddh-guanosine triphosphate (ddhGTP) and ddh-uridine triphosphate (ddhUTP). We further show that prokaryotic viperins protect against T7 phage infection by inhibiting viral polymerase-dependent transcription, suggesting that it has an antiviral mechanism of action similar to that of animal viperin. Our results reveal a class of potential natural antiviral compounds produced by bacterial immune systems.

Cyclic GMP-AMP signalling protects bacteria against viral infection

The cyclic GMP-AMP synthase (cGAS)-STING pathway is a central component of the cell-autonomous innate immune system in animals^1,2. The cGAS protein is a sensor of cytosolic viral DNA and, upon sensing DNA, it produces a cyclic GMP-AMP (cGAMP) signalling molecule that binds to the STING protein and activates the immune response^3-5. The production of cGAMP has also been detected in bacteria⁶, and has been shown, in Vibrio cholerae, to activate a phospholipase that degrades the inner bacterial membrane⁷. However, the biological role of cGAMP signalling in bacteria remains unknown. Here we show that cGAMP signalling is part of an antiphage defence system that is common in bacteria. This system is composed of a four-gene operon that encodes the bacterial cGAS and the associated phospholipase, as well as two enzymes with the eukaryotic-like domains E1, E2 and JAB. We show that this operon confers resistance against a wide variety of phages. Phage infection triggers the production of cGAMP, which-in turn-activates the phospholipase, leading to a loss of membrane integrity and to cell death before completion of phage reproduction. Diverged versions of this system appear in more than 10% of prokaryotic genomes, and we show that variants with effectors other than phospholipase also protect against phage infection. Our results suggest that the eukaryotic cGAS-STING antiviral pathway has ancient evolutionary roots that stem from microbial defences against phages.

Systematic discovery of antiphage defense systems in the microbial pangenome

The arms race between bacteria and phages led to the development of sophisticated antiphage defense systems, including CRISPR-Cas and restriction-modification systems. Evidence suggests that known and unknown defense systems are located in "defense islands" in microbial genomes. Here, we comprehensively characterized the bacterial defensive arsenal by examining gene families that are clustered next to known defense genes in prokaryotic genomes. Candidate defense systems were systematically engineered and validated in model bacteria for their antiphage activities. We report nine previously unknown antiphage systems and one antiplasmid system that are widespread in microbes and strongly protect against foreign invaders. These include systems that adopted components of the bacterial flagella and condensin complexes. Our data also suggest a common, ancient ancestry of innate immunity components shared between animals, plants, and bacteria.

Elevated alanine aminotransferase independently predicts new onset of depression in employees undergoing health screening examinations

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of elevated alanine aminotransferase (ALT). NAFLD is associated with insulin resistance and hepatic inflammation. Similarly, patients with depression exhibit insulin resistance and increased inflammatory markers. However, no study has shown a clear association between elevated ALT and the development of depression. The aim of the study was to test whether elevated ALT, a surrogate marker for NAFLD, predicts the development of depression.

METHOD

The present prospective cohort study investigated 12 180 employed adults referred for health examinations that included fasting blood tests and anthropometric measurements between 2003 and 2010. Exclusion criteria were: baseline minor/major depression, excessive alcohol consumption and other causes for ALT elevation. Depression was evaluated by the eight-item Patient Health Questionnaire (PHQ-8) score.

RESULTS

The final cohort included 5984 subjects [69.4% men, aged 45.0 (s.d. = 10.24) years]. The incidence rate of minor and major depression was 3.8% and 1.4%, respectively. Elevated ALT was a significant independent predictor for the occurrence of minor [odds ratio (OR) 2.02, 95% confidence interval (CI) 1.40-2.92] and major (OR 3.132, 95% CI 1.81-5.40) depression after adjusting for age, gender, body mass index, education level, serum levels of lipids, glucose, smoking and physical activity. Adding subjective health and affective state parameters (sleep disturbances, self-rated health, anxiety and burnout) as potential mediators only slightly ameliorated the association. Persistently elevated ALT was associated with the greatest risk for minor or major depression as compared with elevation only at baseline or follow-up (p for trend < 0.001).

CONCLUSIONS

Elevated ALT was associated with developing depressive symptoms, thus suggesting that NAFLD may represent an independent modifiable risk factor for depression.

Biochar mitigates negative effects of salt additions on two herbaceous plant species

Addition of pyrolyzed biomass ("biochar") to soils has commonly been shown to increase crop yields and alleviate plant stresses associated with drought and exposure to toxic materials. Here we investigate the ability of biochar (at two dosages: 5 and 50 t ha(-1)) to mitigate salt-induced stress, simulating road salt additions in a factorial glasshouse experiment involving the broadleaved herbaceous plants Abutilon theophrasti and Prunella vulgaris. Salt additions of 30 g m(-2) NaCl to unamended soils resulted in high mortality rates for both species. Biochar (Fagus grandifolia sawdust pyrolyzed at 378 °C), when applied at 50 t ha(-1) as a top dressing, completely alleviated salt-induced mortality in A. theophrasti and prolonged survival of P. vulgaris. Surviving A. theophrasti plants that received both 50 t ha(-1) biochar and salt addition treatments showed growth rates and physiological performance similar to plants without salt addition. Biochar treatments alone also substantially increased biomass of P. vulgaris, with a ∼50% increase relative to untreated controls at both biochar dosages. Biochar did not significantly affect photosynthetic carbon gain (Amax), water use efficiency, or chlorophyll fluorescence (Fv/Fm) in either species. Our results indicate that biochar can ameliorate salt stress effects on plants through salt sorption, suggesting novel applications of biochar to mitigate effects of salinization in agricultural, urban, and contaminated soils.

Assessment of high-sensitivity CRP as a marker of micro-inflammation in irritable bowel syndrome

BACKGROUND

The diagnosis of irritable bowel syndrome (IBS) is symptom-based. Although considered a functional disease, accumulating evidence supports a low-grade gut inflammation as an element of its pathophysiology. Thus, high-sensitivity C-reactive protein (hs-CRP), a marker of micro inflammation, may be elevated in IBS. Our aim was to assess whether hs-CRP is higher in IBS patients compared to healthy controls (HC) and does it differ among the IBS clinical subgroups and correlate with disease severity.

METHODS

A diagnostic case control study was conducted in two gastroenterology departments. Eighty-eight IBS patients who were recruited prospectively answered the Rome III diagnostic questionnaire. They all completed the Functional Bowel Disorder Severity Index (FBDSI), dietary, and general health questionnaires. All patients underwent blood sampling for hs-CRP levels. Each IBS patient was matched to four HC by age, gender, and BMI. Blood samples were obtained from the HC at a periodic health survey.

KEY RESULTS

The mean hs-CRP level in the IBS group was significantly higher than in HC (1.17±1.26mg L(-1) vs 0.72±0.91mg L(-1) respectively, P=0.001). Hs-CRP levels were highest in patients with diarrhea-predominant IBS and in patients with greater disease severity. A cut-off value of 1.08mg L(-1) had a sensitivity of 60.2% and a specificity of 68% for differentiating IBS from HC.

CONCLUSIONS & INFERENCES

Hs-CRP levels are higher in IBS patients than HC, but still in the normal laboratory range. This may reflect the low-grade gut inflammation believed to occur in IBS and support its existence.

A 1-year study to compare the efficacy and safety of once-daily travoprost 0.004%/timolol 0.5% to once-daily latanoprost 0.005%/timolol 0.5% in patients with open-angle glaucoma or ocular hypertension

PURPOSE

The objective of the study was to compare the intraocular pressure (IOP)-lowering efficacy and safety of travoprost 0.004%/timolol 0.5% ophthalmic solution (Trav/Tim) to latanoprost 0.005%/timolol 0.5% ophthalmic solution (Lat/Tim), dosed once daily in the morning, in patients with open-angle glaucoma (OAG) or ocular hypertension (OH).

METHODS

This was a randomized, double-masked, multicenter, parallel group, active-controlled study conducted at 41 sites. At the eligibility visit the patients were randomized (1:1) to the assigned masked medication if they met inclusion/exclusion criteria, and the mean IOP values in the eligible eyes were > or =24 mmHg at 9 AM and > or =21 mmHg at 11 AM and 4 PM. Patients were excluded if the mean IOP in either eye was >36 mmHg. Patients were instructed to administer the assigned medication each morning at 9 AM. During the treatment phase of the study, IOP was measured at 9 AM at week 2, week 6, month 3, and month 9. At the month 6 and month 12 visits, IOP was measured at 9 AM, 11 AM, and 4 PM. Statistical methods included a repeated measures analysis of variance (ANOVA); to test for noninferiority, a 95% confidence interval for the treatment group difference was constructed based on the ANOVA results for each time point at month 12.

RESULTS

Patients (n=408) with OAG or OH were enrolled at 41 sites. One patient withdrew prior to receiving medication so 207 in the Trav/Tim group and 200 in the Lat/Tim group were evaluable for safety. Baseline demographic characteristics as well as IOP values showed no statistical differences between the two groups. Trav/Tim provided lower mean IOP values than Lat/Tim that were statistically significant at the week 2 9 AM (p=0.0081), month 6 9 AM (p=0.0056), and month 6 11 AM (p=0.0128) time points and at 9 AM time point pooled across all visits (p=0.0235) when mean IOP was 0.6 mmHg lower in the Trav/Tim group. Treatment-related adverse events were mild in both groups. Although hyperemia was reported from a higher percentage of patients in Trav/Tim group, differences in average hyperemia scores between the two groups were not considered clinically relevant.

CONCLUSIONS

Travoprost 0.004%/timolol 0.5% ophthalmic solution produced mean IOP levels that are statistically noninferior to latanoprost 0.005%/timolol 0.5% ophthalmic solution. Furthermore, at 9:00 AM, 24 hours after dosing, IOP was statistically lower for travoprost 0.004%/timolol 0.5% pooled across all visits. Travoprost 0.004%/timolol 0.5% fixed combination ophthalmic solution is an effective treatment for reducing IOP and it is safe and well-tolerated in patients with OAG or OH.

Heart rate and microinflammation in men: a relevant atherothrombotic link

OBJECTIVE AND BACKGROUND

To explore the possibility that increased resting heart rate (HR) is associated with a microinflammatory response. Such an association could explain, at least in part, the recently described worse cardiovascular prognosis in individuals with increased HR.

METHODS

Concentrations of fibrinogen and high-sensitivity C-reactive protein, as well as the absolute number of polymorphonuclear leucocytes, were analysed in a cohort of 4553 apparently healthy men and in those with atherothrombotic risk factors.

RESULTS

Following adjustment for age and body mass index, lipid profile and cardiovascular risk factors, a significant (p<0.001) difference was noted between individuals in the first quintile of HR (< or =58 beats/min) and those in the fifth quintile (> or =79 beats/min) regarding all the above-mentioned inflammatory biomarkers, the respective mean values being 7.38 and 8.11 micromol/l, 1.12 and 1.61 mg/l, and 4.23 and 4.74 x 10(9)/l.

CONCLUSIONS

Resting HR is associated with a microinflammatory response in apparently healthy men and in those with atherothrombotic risk factors. Sympathetic activation might be a common factor explaining such an association. If confirmed in additional studies, this association might be a relevant target for therapeutic manipulations.

ITS2 sequences as barcodes for identifying and analyzing spider mites (Acari: Tetranychidae)

The use of DNA barcodes, short DNA sequences from a standardized region of the genome, has recently been proposed as a tool to facilitate species identification and discovery. Here we show that second internal transcribed spacer of nuclear ribosomal DNA (rDNA-ITS2) barcodes effectively discriminate among 16 species of spider mites (Acari: Tetranychidae) from Israel. The barcode sequences of each species were unambiguously distinguishable from all other species and formed distinct, nonoverlapping monophyletic groups in the maximum-parsimony tree. Sequence divergences were generally much greater between species than within them. Using a 0.02 (2%) threshold for species diagnosis in our data set, 14 out of 16 species recognized by morphological criteria would be accurately identified. The only exceptions involved the low divergence, 0.011-0.015 (1.1-1.5%), between Tetranychus urticae and Tetranychus turkestani, where speciation may have occurred only recently. Still, these species had fixed alternative rDNA-ITS2 variants, with five diagnostic nucleotide substitutions. As a result, we tentatively conclude that rDNA-ITS2 sequence barcodes may serve as an effective tool for the identification of spider mite species and can be applicable as a diagnostic tool for quarantine and other pest management activities and decision-making. We predict that our work, together with similar efforts, will provide in the future the platform for a uniform, accurate, practical and easy-to-use method of spider mite species identification.

Skin test results and self-reported symptom severity in allergic rhinitis: the role of psychological factors

BACKGROUND

In allergic conditions, the degree of skin test reactivity does not always correlate with the severity of clinical symptoms. Additional factors may contribute to the reported symptom severity.

OBJECTIVES

To investigate the association between the magnitude of the skin prick test (SPT) response and the reported symptom severity in patients with allergic rhinitis and the possible modifying role of psychological factors.

METHODS

One hundred four patients with allergic rhinitis and 23 with non-allergic rhinitis, classified according to their SPT response to 19 aeroallergens, were asked to rate the severity of five symptoms and to indicate whether their symptoms intensified on exposure to five common aeroallergens. They also completed a psychological questionnaire. Results Reported symptom severity of allergic rhinitis did not correlate with weal size for any of the aeroallergens tested or with the number of positive responses on SPT. It was not related to patient age, sex, or education. The reported symptoms severity correlated positively (0.29, P < 0.01) with reported symptom intensification on exposure to allergens. Moreover, both outcomes were positively associated with the psychological factors of hypochondriasis (0.20, P < 0.05 and 0.18, P < 0.05, respectively), and somatic awareness (0.24, P < 0.05 and 0.33, P < 0.01, respectively), but not with neuroticism.

CONCLUSIONS

The severity of symptoms experienced by patients with allergic rhinitis is apparently not related to the magnitude of SPT response, but rather to psychological factors of hypochondriasis and somatic awareness. Physicians should be aware of the contribution of psychological factors to patient perceptions of the intensity of symptoms and of the intensification of symptoms on their exposure to allergens.

Diurnal IOP control with bimatoprost versus latanoprost in exfoliative glaucoma: a crossover, observer-masked, three-centre study

AIM

To evaluate the diurnal intraocular pressure (IOP) control and safety of bimatoprost versus latanoprost in exfoliative glaucoma (XFG).

METHODS

One eye of 129 consecutive patients with XFG (mean (SD) age 66.5 (8.3) years) was included in this prospective, observer-masked, three-centre, crossover comparison. After a 4-6 week medicine-free period patients were randomised to bimatoprost or latanoprost monotherapy for 3 months. Patients were then switched to the opposite treatment for another 3 months. At the end of the washout and the treatment periods diurnal IOP was measured at 0800, 1300, and 1800.

RESULTS

At baseline the IOP (mean (SD)) was 28.0 (4.0), 26.9 (3.6), and 25.9 (3.6) mm Hg, at the three time points, respectively. Both treatments significantly reduced mean diurnal IOP at month 3. Mean diurnal IOP was 26.9 (3.5) mm Hg at baseline, 17.6 (3.3) mm Hg with bimatoprost, and 18.6 (3.6) mm Hg with latanoprost (p<0.0001). Furthermore, lower IOP values were obtained with bimatoprost at all time points (17.9 (3.4), 17.3 (3.3), and 17.6 (3.5) mm Hg, respectively) compared with latanoprost (18.7 (3.6), 18.5 (3.6), and 18.6 (4.1) mm Hg, respectively). The corresponding mean differences (0.8, 1.1, and 1.0 mm Hg, respectively) were all significant (p<0.001 for each comparison). Significantly more patients with XFG obtained a target diurnal IOP <17 mm Hg with bimatoprost than with latanoprost, 55/123 (45%) v 34/123 (28%); (p = 0.001), and significantly fewer patients were non-responders with bimatoprost than with latanoprost (5 v 13, p = 0.021). More patients reported at least one adverse event with bimatoprost than with latanoprost (58 v 41 at 3 months; p = 0.0003).

CONCLUSION

This crossover study suggests that better diurnal IOP control is obtained with bimatoprost than with latanoprost in patients with XFG.

Oral Temperature in Daily Life. A New Look in the Era of Microinflammation

It has been repeatedly shown that apparently healthy individuals and those with atherothrombotic risk factors harbor a low grade subclinical internal inflammation (microinflammation). This low grade acute phase response is relevant for the presence of atherothrombosis and future vascular events. Since these events are associated with a febrile response, we thought that it is relevant to clarify whether the microinflammatory response has an influence on the oral temperature. Included were 2,340 men and 1,280 women in whom the white blood cell count (WBCC) and differential, as well as the erythrocyte sedimentation rate (ESR), quantitative fibrinogen and high sensitivity C-reactive protein (hs-CRP) were determined in addition to the oral temperature in quiescent conditions. There was no association between these inflammatory biomarkers, except from a weak association with the absolute number of polymorphonuclear leukocytes. This association could be, however, related to the stress of the examination itself. Thus, it is unlikely that the microinflammatory response in daily life is associated, to a significant degree, with an enhanced oral temperature. The results are relevant for the findings of elevated oral temperature during conditions of acute ischemia/infarction where the temperature is probably related to the event itself and not to the patient's background microinflammation.

Increased erythropoiesis and subclinical inflammation as part of the metabolic syndrome

Recent studies have suggested the insulin resistance might be accompanied by enhanced erythropoiesis. We have examined this association in individuals with the metabolic syndrome (MS) who in addition to insulin resistance harbor a chronic low grade inflammation. This study is relevant because chronic inflammation might have a suppressive effect on erythropoiesis. 280 and 554 non-smoking women and men with respective age of 46.4+/-9.3 (mean+/-S.D.) and 44.0+/-11.0 years are included. A significant correlation was noted between the numbers of the components of the MS and the inflammatory biomarkers including the white blood cell count, high sensitivity C-reactive protein, fibrinogen concentrations and the erythrocyte sedimentation rate. In addition, a significant correlation (r=0.157, p=0.008) was noted between the number of components of the MS and the number of red blood cells in the peripheral blood in women. The same was true for men (r=0.192, p<0.0005). We conclude that enhanced erythropoiesis could be a new, hitherto unrecognized component of the MS. The enhanced erythropoiesis could give an erroneous impression of general "good" health in these individuals.

Obesity-related correlation between C-reactive protein and the calculated 10-y Framingham Coronary Heart Disease Risk Score

OBJECTIVE

To clarify the role of body mass index (BMI, kg/m(2)) adjustment in predictive models for cardiovascular events that add high-sensitivity C-reactive protein (hs-CRP) to the 10-y Framingham Coronary Heart Disease Risk Score (FCRS).

DESIGN

A cross-sectional study in a group of apparently healthy individuals.

SUBJECTS

In all, 1512 apparently healthy individuals (955 men and 557 women) at a respective age of 49.7+/-10.6 and 50.6+/-9.6 y.

RESULTS

The Pearson correlation between hs-CRP and the calculated 10-y FCRS was lower when adjusted for BMI. This reduction was especially noted in women where it dropped from 0.247 to 0.09. The dominant role of hs-CRP concentrations was also noted in a linear regression model, again, especially noted in women (drop of the standardized coefficient from 0.517 for BMI to 0.08 for the FCRS).

CONCLUSIONS

The correlation between hs-CRP and the 10-y FCRS is partly related to the presence of obesity. We raise the possibility that the addition of BMI to the predictive model of FCRS might attenuate the cost-effectiveness of CRP measurements for this specific risk assessment.

Pingelapese achromatopsia: correlation between paradoxical pupillary response and clinical features

AIM

To evaluate the paradoxical pupillary constriction in darkness in patients with Pingelapese achromatopsia (PA), and to describe a connection between this phenomenon and the clinical features.

METHODS

27 patients with PA were examined. All underwent a full ophthalmic examination which included Snellen visual acuity and ophthalmoscopy. Colour vision examination was performed with Ishihara pseudoisochromatic plates and also with a colour plate consisting of five basic colours (red, green, purple, yellow, and orange). Paradoxical pupillary response was examined and documented with a special infrared video camera. Pupils' images were analysed using the Scion Image program and the ratio of pupil size in darkness to its size in light was calculated and recorded.

RESULTS

Mean visual acuity was 20/400 (range 20/80-20/800). Colour vision examination showed a mean of 3.2 (SD 1.5) (range 1-5) of Ishihara colour plates, and 0.5 (0.75) (0-3) of basic colour plates. 23 patients (85%) had paradoxical pupillary constriction in darkness. Mean dark/light ratio of pupillary area was 0.86 (range 0.5-1.6). In patients with marked paradoxical pupillary constriction there was a significant correlation of visual acuity and Ishihara score.

CONCLUSIONS

Clinical manifestations of achromatopsia include total colour blindness, low visual acuity (mean of 20/400), horizontal pendular or rotatory nystagmus, and photophobia. Most patients have paradoxical pupillary constriction in darkness. When this response is brisk it seems to correlate with lower visual acuity and lower Ishihara score.

Neuroprotective properties of a synthetic docosanoid, unoprostone isopropyl: clinical benefits in the treatment of glaucoma

The characteristic loss of visual field due to glaucoma is directly associated with retinal ganglion cell (RGC) death. The process of RGC death is thought to be biphasic, starting with a primary injury, followed by a slow secondary degeneration. Retinal ischemia may establish the cellular conditions that create a fatal biochemical cascade; hypoxia, followed by high excitotoxic levels of glutamate cause pathologically elevated levels of intracellular calcium resulting in neuronal cell death via apoptosis or necrosis. Impaired ocular perfusion, primarily due to abnormal autoregulation and/or vasoconstriction caused by endothelin-1, probably contributes to the ischemic milieu. Neuroprotection, the preservation of neurons that were either not damaged or only slightly damaged during the primary insult, has become important for the clinician when considering treatment options. Unoprostone, the first synthetic docosanoid, has been demonstrated to exhibit neuroprotective properties. In an ischemic animal model, unoprostone protected RGCs in a dose-dependent manner. Unoprostone inhibits glutamate stimulation and opens maxi-K channels, which are potassium channels that reach an activation threshold only during depolarization and/or at high intracellular Ca2+ concentrations. The resultant large efflux of K+ hyperpolarizes the cell, thereby closing voltage-gated Ca2+ channels and limiting neuronal damage by decreasing influx of intracellular Ca2+. Unoprostone has also been shown to protect rat photoreceptors from constant light-induced damage. Lastly, unoprostone has vasorelaxant properties, evidenced by increased choroidal blood flow and inhibition of vasoconstrictors such as endothelin-1. These findings indicate that a substantial clinical benefit of unoprostone is neuroprotection of RGCs.

Detection of phytoplasma by polymerase chain reaction of insect feeding medium and its use in determining vectoring ability

A polymerase chain reaction (PCR)-based method was developed for the detection of phytoplasma in insect feeding medium (sucrose). A correlation was established between the transmissibility of Flavescence dorée phytoplasma in the experimental leafhopper vector Euscelidius variegatus and its detection by PCR in the insect feeding medium. However, phytoplasma were detected in the insects' bodies 3 weeks before they began to transmit. Hence, PCR assays of the sucrose medium reflected phytoplasma vectoring ability probably by detecting it in the insect saliva, whereas detection of phytoplasma in the insect's body did not identify it as a vector. The assay was applied to two field-collected leafhoppers suspected of being phytoplasma vectors in Israel (Orosius albicinctus and Anaceratagallia laevis). The presence of phytoplasma in the body of specimens of the latter species was assayed by PCR in 1999. Phytoplasmas were detected in insects' bodies throughout the year, with no specific seasonal pattern. In the saliva, however, no phytoplasma could be detected in the autumn. This seasonal pattern supported the validity of the feeding-medium tests and their correlation to the insect's ability to transmit phytoplasma. Transmission assays indicated, to our knowledge for the first time, that O. albicinctus and A. laevis are vectors of phytoplasma in Israel. A simple PCR-based assay is thus provided, circumventing the need for tedious biological assays and enabling epidemiological studies of phytoplasma transmissibility on a large scale.

Low job satisfaction predicts delayed return to work after laparoscopic cholecystectomy

We studied 102 consecutive employed patients treated by elective laparoscopic cholecystectomy to determine job characteristics and psychological factors that predict delay in return to work after their procedure. Median sick leave was 13 days, and five variables significantly added to a model predicting sick leave of at least 20 days (31.4% of the workers): low job satisfaction (odds ratio [OR], 12.56; 95% confidence interval [CI], 3.34 to 47.2); physical effort at work (OR, 4.99; 95% CI, 1.46 to 17.04); pain at 7 days (OR, 5.55; 95% CI, 1.56 to 19.76); patient's expectation of slow recovery (> 7 days) (OR, 6.12; 95% CI, 1.82 to 20.55); and patient's expectation of no financial loss (OR, 3.85; 95% CI, 1.14 to 12.50). The model was excellent (area under the receiver operating characteristic curve, 89.6%). We conclude that low job satisfaction is a major predictor of delayed return to work.

The interactive effect of chronic exposure to noise and job complexity on changes in blood pressure and job satisfaction: a longitudinal study of industrial employees

The hypothesis of this study was that noise exposure level and job complexity interact to affect changes in blood pressure (BP) levels and job satisfaction over 2-4 years of follow-up. Results showed that among workers exposed to high noise, those with complex jobs showed increases in BP that were more than double shown by those with simple jobs. Under low noise exposure, there was a small increase in BP for workers with complex jobs but about a 3-fold increase in workers with simple jobs. The prevalence of elevated BP showed a similar trend. Job satisfaction increased among workers with complex jobs but was much less in those exposed to high noise. It was concluded that exposure to occupational noise has a greater negative impact on changes in BP and job satisfaction over time among those performing complex jobs. In contrast, job complexity had a clear beneficial effect for workers exposed to low noise.

The relationships among objective and subjective environmental stress levels and serum uric acid: the moderating effect of perceived control

This study was designed to investigate the effects of objective and subjective stress levels and perceived control on serum uric acid (SUA). Respondents were 2,504 male and 1,176 female manufacturing employees. Objective job-related stress was assessed by the Ergonomic Stress Level (ESL) inventory (S. Melamed, D. Yekutieli, P. Froom, E. Kristal-Boneh, & J. Ribak, 1999). As expected, ESL was positively associated with SUA, but among male respondents only. The measure of subjective stress, environmental annoyance, was negatively related with SUA for male respondents, thus not confirming the hypothesis. Perceived control was not found to have a direct effect on SUA, after controlling for the ESL measure. For male respondents only, perceived control moderated the relationship between ESL and SUA: This relationship was negative for those reporting above-average control and positive for those reporting below-average control.

Serum total cholesterol and cardiovascular mortality in Israeli males: the CORDIS Study. Cardiovascular Occupational Risk Factor Determination in Israeli Industry

BACKGROUND

The degree to which serum total cholesterol predicts cardiovascular disease is uncertain. While most authors have placed TC among the most powerful risk indicators of CVD, some have claimed that it predicted CVD in women only, or even not at all.

OBJECTIVE

To determine the predictive value of serum total cholesterol relative to diabetes, smoking, systolic blood pressure and body mass index (kg/m2), for cardiovascular disease mortality in 3,461 occupationally active Israeli males.

METHODS

A prospective follow-up was carried out for the years 1987-1998 to determine the effect of age, smoking habits, a history of diabetes, SBP, BMI and TC, at entry, on CVD mortality.

RESULTS

There were 84 CVD deaths during a total of 37,174 person-years follow up. The hazard ratios (95% confidence intervals) for CVD mortality with respect to variables at entry were: diabetes 5.2 (2.1-13.2), age 2.2 (1.7-2.9), smoking 1.3 (1.0-1.8), SBP 1.4 (1.1-2.0), TC 1.5 (1.0-2.1) and BMI 1.2 (0.7-2.2). Among non-obese, non-diabetic, normotensive subjects the hazard ratio of TC adjusted for age and smoking was 1.16 (1.09-1.22) per 10 mg/dl. In the remaining subjects it was 1.04 (0.98-1.12) only. There was a significant interaction between TC and diabetes, hypertension or obesity (P = 0.003).

CONCLUSIONS

In this population of Israeli males we found an interaction between TC and other risk indicators for CVD. Confirmation is required for the unexpected finding that the predictive value of TC for CVD mortality among non-diabetic, non-obese and normotensive subjects exceeded that among subjects with either of these risk factors.

The relationships among objective and subjective environmental stress levels and serum uric acid: the moderating effect of perceived control

This study was designed to investigate the effects of objective and subjective stress levels and perceived control on serum uric acid (SUA). Respondents were 2,504 male and 1,176 female manufacturing employees. Objective job-related stress was assessed by the Ergonomic Stress Level (ESL) inventory (S. Melamed, D. Yekutieli, P. Froom, E. Kristal-Boneh, & J. Ribak, 1999). As expected, ESL was positively associated with SUA, but among male respondents only. The measure of subjective stress, environmental annoyance, was negatively related with SUA for male respondents, thus not confirming the hypothesis. Perceived control was not found to have a direct effect on SUA, after controlling for the ESL measure. For male respondents only, perceived control moderated the relationship between ESL and SUA: This relationship was negative for those reporting above-average control and positive for those reporting below-average control.

Tonsillar pain mimicking glossopharyngeal neuralgia as a complication of vagus nerve stimulation: case report

An adolescent girl presented with severe, lancinating tonsillar pain exacerbated by swallowing 6 weeks after initiation of left vagus nerve stimulation for intractable epilepsy. Her symptoms mimicked those seen in glossopharyngeal neuralgia and were relieved by temporary cessation of stimulation. Gradual reinstitution of therapy with alteration in stimulus parameters resulted in improved seizure control as well as cessation of pain symptoms. Direct stimulation of the vagus nerve may result in vagoglossopharyngeal neuralgia, which, in this case, was amenable to stimulus modification.

[Early detection of glaucoma by a mobile unit--results from 10,000 examinees]

Glaucoma, the third leading cause of blindness in the western world, is characterized by painless, gradual loss of visual fields which may lead to severe visual impairment or even blindness. In 4 years of operation of a mobile glaucoma unit for screening and early diagnosis of glaucoma, 10,037 subjects aged 18-95 years were screened (4504 women, 45%); 55% were under 50 years (Graph 1). Ocular hypertension was diagnosed in 8.0%; primary open angle glaucoma (POAG) in 0.8%, with 2/3 already under treatment, the rest newly diagnosed. Pseudo-exfoliative glaucoma was diagnosed in 0.2%; only 2 cases had closed angle glaucoma; 91% of those screened were normal (Fig. 4; age stratification, Graph 3). POAG increased with age, from 0.2% in those under 40 years to 10% in those over 80; POAG was more common in men, but OHT was similar in both sexes (6.0% vs. 5.3%). There was no correlation between incidence of POAG and place of work except in the Sorek Nuclear Center (1.9% vs. 0.8%, p = 0.11). Other conditions significantly more frequent in POAG than normals were diabetes mellitus (x 2.5), systemic hypertension (x 4), myopia (x 2) and history of intraocular surgery (x 6).

Association of physical activity at work with mortality in Israeli industrial employees: the CORDIS study

The objective of this study was to evaluate the association of physical activity at work with the risk of all-cause cardiovascular disease and cancer mortality. The cohort consisted of 3488 male, Israeli, industrial employees who participated in an 8-year follow-up study. During this period 129 deaths were recorded: 54 from cardiovascular disease, 47 from cancer, and 28 from other causes. Physical activity at work was assessed at entry on a 4-point scale (none, light, medium, and high). Potential confounding demographic, anthropometric, and socioeconomic variables, and health habits including leisure time physical activity were accounted for. We found that the hazard ratio of all-cause mortality in workers with a high physical workload was 1.82 (95% confidence interval, 1.18 to 2.81) compared with workers having a low workload. A similar trend was noted for cardiovascular disease and cancer mortality. We concluded that a high physical workload is associated with increased mortality rates. Future studies should differentiate between leisure time and work time physical activity.

Ongoing clinical assessment of the safety profile and efficacy of brimonidine compared with timolol: year-three results. Brimonidine Study Group II

OBJECTIVE

We compared the safety profile and efficacy of brimonidine 0.2% BID with those of timolol 0.5% BID over 3 years in patients with ocular hypertension and glaucoma.

METHODS

Ninety-four eligible patients from an ongoing multicenter, interventional, double-masked clinical trial were followed through year 3, 48 receiving brimonidine 0.2% and 46 receiving timolol 0.5%. Study visits occurred at months 24, 27, 30, 33, and 36. The primary efficacy variable was mean reduction from baseline intraocular pressure (IOP) at trough. Visual acuity, visual fields, and safety variables (adverse events, ocular symptoms, heart rate, blood pressure, and laboratory test results) were monitored throughout the study.

RESULTS

The 2 treatment groups were well matched, with no significant differences in demographic or clinical characteristics. Both drug regimens caused significant mean reductions from baseline IOP at trough during year 3 (P < 0.001), with no significant differences between groups at any study visit. The overall mean reduction from baseline IOP at trough was 5.02 mm Hg with brimonidine and 5.57 mm Hg with timolol (P = 0.383). Brimonidine caused reductions in IOP at trough that were equivalent to those with timolol at months 30 and 36 (within the 95% CI). Visual fields were unchanged or improved in 95% of patients in both treatment groups. Both drug regimens appeared to be safe and were well tolerated. Ocular allergy occurred in 2 brimonidine-treated patients (4.2%). There were no statistically significant differences in adverse-event reports and no clinically significant effects on any ocular or systemic safety variable in either group.

CONCLUSIONS

Brimonidine 0.2% BID continues to appear to be safe, well tolerated, and effective in the long-term management of ocular hypertension and glaucoma. Over 3 years, it provided sustained IOP-lowering efficacy and visual-field preservation equal to those with timolol 0.5% BID.

Debilitating beliefs, emotional distress and quality of life in patients given immunotherapy for insect sting allergy

BACKGROUND

Patients who receive immunotherapy for systemic reaction to insect stings are told that once they reach maintenance dose they are almost 100% protected against future systemic reactions. However, we have observed that some patients continued to perceive themselves as highly debilitated by the allergy, and this perception had a significant impact on their quality of life.

OBJECTIVE

To validate this clinical observation and to explore possible reasons for such an undesired psychological reaction.

METHODS

The study group consisted of 97 patients who regularly attended an allergy outpatient clinic for venom immunotherapy, and who had been under medical surveillance for up to 8 years. They completed a questionnaire measuring debilitating beliefs, preoccupation with the systemic reaction event, emotional distress, perceived restriction by allergy, and perceived quality of life. We also recorded the duration of immunotherapy, physician-graded severity of the systemic reaction and the frequency at which immunotherapy was administered. The reference group consisted of patients who had not reached maintenance dose and were still at risk of recurrent systemic reactions.

RESULTS

As many as one-third of the patients held self-imposed debilitating beliefs, were preoccupied with the systemic reaction event, perceived a moderate to severe impairment in their quality of life, and manifested symptoms of emotional distress. These psychological responses did not correlate with the immunotherapy dosage that had been reached. Patients who reached a full maintenance dose were doing no better psychologically than those in the reference group. Moreover, the length of time on immunotherapy did not result in attenuation of the psychological responses.

CONCLUSION

This study demonstrates for the first time, the long-lasting psychological impact of a threatening systemic reaction. It suggests a need for intervention aimed at dispelling patients' unfounded and persisting debilitating beliefs.

Correlation of work structure and job satisfaction among Israeli family physicians

BACKGROUND

Physicians need a professional environment that is conducive to efficient and satisfying work. Little has been published about the effect of work structure on the satisfaction that family physicians derive from their work.

OBJECTIVES

To assess the structure and the positive and negative job components of family physicians in Israel, as well as the effect of these components on their satisfaction with their work.

METHODS

A questionnaire was sent to a random selection of members of the Israel Society of Family Physicians (n = 225).

RESULTS

Altogether 183 questionnaires were returned. Specialist family doctors, practice medical directors and salaried doctors were involved in more activities than non-specialist doctors, trainees and self-employed doctors. Overall satisfaction was highest for specialists and lowest for non-specialists. Work overload, insufficient resources and abundant paperwork were most frequently cited as negative work components. The opportunity to utilize medical knowledge, challenging work and work variety scored highest as positive components.

CONCLUSIONS

The more professionally active physicians were also the more satisfied. Clinical work and teaching provided the most satisfaction, while administrative work and lack of time were the main causes of dissatisfaction.

Association between burnout at work and leukocyte adhesiveness/aggregation

OBJECTIVE

This study examined whether burnout at work is associated with leukocyte adhesiveness/aggregation (LAA), a phenomenon known to be affected by stress.

METHODS

The LAA levels of 179 employees (68 men and 111 women) of Tel Aviv University were determined when the employees underwent their annual routine medical checkup. Blood pressure and toxic chemical exposure were also measured, and background data were retrieved from medical records. Information on burnout and somatic complaints (known to be a general marker of stress) was collected through a self-report questionnaire.

RESULTS

Total burnout and each of its subcomponents, emotional exhaustion, chronic fatigue, and cognitive weariness, was significantly associated with LAA levels, even after controlling for age, sex, and educational level. Burnout and somatic complaints intercorrelated positively, but somatic complaints were not significantly associated with LAA levels before or after controlling for the above possible confounders.

CONCLUSIONS

Burnout was positively associated with LAA levels. This finding is consistent with the growing evidence of the negative impact of burnout on physical health. The lack of an association between somatic complaints and LAA levels reinforces the claim that burnout and stress are two different concepts.

Referral to occupational medicine clinics and resumption of employment after myocardial infarction

Rehabilitation after acute myocardial infarction (AMI) consists of education, exercise, and an encouragement to return to work (RTW). This study attempts to (1) determine whether the time interval between AMI and the visit at occupational medicine (OM) clinics predicts resumption of full employment, and (2) estimate the incidence of work-related recurrent AMI after RTW. We followed 216 consecutive AMI patients at a single OM clinic. The independent variables were clinical and personal data, physical workload and time between AMI, and first visit to the OM clinic. The outcome variables were full employment 24 months after the acute event and recurrent AMI during this period. Of all patients, 168 attempted RTW. Of these, 18 stopped working subsequently. Of the remaining 150 patients, 54 returned to part-time work and 96 were employed full-time after 2 years. Logistic regression indicated that a failure to resume full employment was independently associated with diabetes, older age, Q wave AMI, angina before AMI, heavy work, and a late visit to the OM clinic. For each month's delay in referral to the OM clinic, there was a 30% decrease in the chance for full employment 24 months after AMI. Six (4%) of the 150 patients who resumed employment sustained a recurrent AMI, two of them while at work. A delayed referral to the OM clinic was associated with work disability after AMI. Late referrals to OM clinics should receive a more intensive and sustained rehabilitation than early referrals. Whether an earlier referral to OM clinics will result in increased RTW rates is unknown. Patients who attempted to resume employment had a 1.2% risk of a recurrent ischemic event at their workplace.

Healthy volunteer effect in industrial workers

Volunteers for epidemiological research, have lower mortality rates than non-volunteers, thereby producing a bias referred to as the "healthy volunteer effect" (HVE). Occupationally active persons have been similarly shown to have a reduced mortality relatively to the general population (the "healthy worker effect"). To determine whether a HVE exists in occupationally active persons, we followed for 8 years a cohort of Israeli male industrial employees, of whom 71.6% agreed to participate in 1985 in screening examinations for cardiovascular disease. We calculated standardized mortality ratios (SMRs) of the entire cohort relative to the general population, and compared the mortality among participants with that of the non-participants. Over 8 years follow up, SMRs were 78% for the entire cohort, 71% for participants and 99% for non-participants. Participants were older than non-participants and worked more commonly in smaller factories. A proportional hazard model indicated that after adjusting for these variables, the all cause mortality hazard ratio among participants and non-participants was 0.69 (95% CI = 0.51-0.94). During the first and last two years of the 8-year follow-up there were 39.6 and 30.0 age-adjusted deaths per 10,000 person-years among participants, and 58.6 and 51.5 respectively among non-participants. We conclude that the HVE occurs in occupationally active persons, and that it may persist for up to 8 years follow-up.

Adverse work and environmental conditions predict occupational injuries. The Israeli Cardiovascular Occupational Risk Factors Determination in Israel (CORDIS) Study

This study was designed to test whether the total objective adverse work and environmental conditions, expressed as the ergonomic stress level (ESL), would predict occupational injuries over a 2-year period. The study population consisted of 4,096 men from 21 factories in six industrial sectors who were studied as part of the Israeli Cardiovascular Occupational Risk Factors Determination in Israel (CORDIS) Study, 1985-1987. The ESL (assigned four levels, 1-4) was based on an ergonomic assessment which covered 17 risk factors pertaining to safety hazards, overcrowding, cognitive and physical demands, and environmental stressors. The ESL was found to be a highly reliable measure and stable over a period of 2-4 years. The incidence of injuries among workers in low ESL conditions (level 1) was 10.3%. It increased with higher ESL's: 11.7% in level 2 (relative risk (RR) = 1.13, 95% confidence interval (CI) 0.86-1.50); 21.6% in level 3 (RR = 2.09, 95% CI 1.68-2.62); and 23.8% in level 4 (RR = 2.31, 95% CI 1.85-2.88). After adjustment for age, job experience, educational level, managerial status, and occupational status (white/blue collar), injury occurrence was significantly elevated for those at level 3 (adjusted odds ratio (OR) = 1.46, 95% CI 1.12-1.91) and level 4 (adjusted OR = 1.81, 95% CI 1.39-2.37) but not for level 2 (adjusted OR = 0.87, 95% CI 0.65-1.18). The authors conclude that adverse work and environmental conditions, objectively assessed, can predict occurrence of occupational injuries.

Chronic burnout, somatic arousal and elevated salivary cortisol levels

Burnout syndrome, comprised of the symptoms of emotional exhaustion, physical fatigue, and cognitive weariness, is believed to be a result of ineffective coping with enduring stress. This study of 111 nonshift blue-collar workers free of cardiovascular disease (CVD) examined whether chronic burnout is associated with a state of somatic and physiological hyperarousal. Results showed that 37 workers exhibited symptoms of chronic burnout, with symptoms lasting at least 6 months. These workers, compared to those with no burnout symptoms (n = 52) or nonchronic burnout symptoms (n = 22), had higher levels of tension at work, postwork irritability, more sleep disturbances and complaints of waking up exhausted, and higher cortisol levels during the work day. These results suggest that chronic burnout is associated with heightened somatic arousal and elevated salivary cortisol levels. This may be part of the mechanism underlying the emerging association between burnout and risk of CVD.

Smoking cessation and body mass index of occupationally active men: the Israeli CORDIS Study

OBJECTIVES

This study estimated weight gain after smoking cessation and identified factors attenuating this gain.

METHODS

We conducted a prospective follow-up of 1209 male factory workers for 2 to 4 years. The independent variables were smoking habits. age, sports activity, education, alcohol consumption, ethnicity, duration of follow-up, and body mass index (BMI, kg/m2) at entry. The dependent variable was increase in BMI during follow-up.

RESULTS

The mean age-adjusted BMI at entry into the study was 26.6 kg/m2 among past smokers and 25.4 kg/m2 among current smokers. There were no differences in BMI between those who quit less than 3 years before entry and those who quit more than 6 years before entry. During follow-up, the average increase in BMI was 0.07 kg/m2 among never smokers, 0.19 kg/m2 among smokers who had stopped smoking before entry, 0.24 kg/m2 among current smokers, and 0.99 kg/m2 among those who stopped smoking after entry. Cessation of smoking after entry predicted an increased gain in BMI; older age, a higher BMI at entry, sports activity, and alcohol consumption attenuated this gain.

CONCLUSIONS

The increased rate of weight gain after smoking cessation is transient. However, the weight gained is retained for at least 6 years.

Emotional reactivity and debilitating beliefs during hospitalization predict future adjustment to first myocardial infarction in men

Research efforts are being made to identify personality and cognitive variables predictive of poor adjustment following myocardial infarction. Sixty-two male patients were examined after a first and uncomplicated myocardial infarction to determine whether dispositional emotional reactivity and debilitating beliefs measured during hospitalization can predict work engagement, social activities involvement, and ambulation/independence six months later. A structural model with direct paths between emotional reactivity, debilitating beliefs, and the above outcomes, as well as partial mediation of emotional distress and illness preoccupation, was tested using the CALIS procedure. The model explained 33%, 48% and 82% of the variance in the three outcomes, respectively. Work engagement was indirectly related through emotional distress to earlier emotional reactivity and debilitating beliefs. Social activities involvement was both directly and indirectly related through emotional distress to debilitating beliefs; and also indirectly related through emotional distress to emotional reactivity. Ambulation/independence was directly and negatively related to debilitating beliefs. Prolonged emotional distress was predicted by emotional reactivity and debilitating beliefs. Illness preoccupation turned out to be an independent outcome that was positively related to emotional reactivity. Thus, measuring dispositional emotional reactivity and debilitating beliefs at the hospitalization stage may be helpful in detecting patients at risk of poor future adjustment.

Malingering assessment in behavioral toxicology: what, why, and how

Neurobehavioral assessment is frequently made in a forensic context. The cognitive assessment may be biased due to an international manipulation of data by the patient motivated by attainment of compensation, that is, malingering. Although malingering is highly relevant in behavioral toxicology, the issue and its assessment are underrepresented in the literature. A routine assessment of malingering is important to reduce false-positive and false-negative errors in assessment, thereby establishing the credibility and validity of behavioral assessment. In the long run, the routine inclusion of malingering measurements might reduce claims and encourage employers to be more cooperative in behavioral toxicology studies. Guidelines for malingering assessment and research, inferred from the clinical and research literature, are discussed. Sensitivity to the problematic issues involved in assessing malingering behavior is an important step toward malingering detection in the clinical setting and to the establishment of assessment methods that are less confounded by these issues.

Association between somatic symptoms and 24-hour ambulatory blood pressure levels

OBJECTIVE

To clarify whether somatic complaints in healthy normotensive men are associated with differential 24-hour blood pressure and heart rate measures.

METHOD

Twenty-four-hour ambulatory systolic and diastolic blood pressure was monitored in 114 healthy normotensive men, aged 28 to 63 years, engaged in similar physical work. Means were calculated for each hour, for the whole 24-hour period, and for daytime, nighttime, and work time. Subjects were interviewed about somatic complaints, demographic data, and health habits, and body mass index was measured.

RESULTS

After controlling for possible confounders, a positive association was found between the somatic complaint score and 24-hour, diurnal, and work-time systolic blood pressure (p = .014, p = .007, and p = .008, respectively). The association with casual systolic blood pressure was of borderline significance (p = .089). There was a positive trend, which did not reach statistical significance, in the relationship between somatic complaint score and all measures of diastolic blood pressure. Diurnal, 24-hour, and work-time heart rates were highest in the subjects with the highest somatic scores (p < .01 for all trends).

CONCLUSIONS

In healthy normotensive men, somatic complaints are associated with an increased cardiovascular load. The effects of this increase on long-term cardiovascular morbidity and mortality are uncertain and warrant additional study.