Pain perception in schizophrenia: no changes in diffuse noxious inhibitory controls (DNIC) but a lack of pain sensitization

BACKGROUND: Pain is a dynamic phenomenon resulting from the activity of both excitatory (e.g. sensitization) and inhibitory endogenous modulation systems. Preliminary experimental studies have shown diminished pain sensitivity in schizophrenia patients. The objective of the study was to investigate the role of excitatory and inhibitory systems on pain perception in schizophrenia. METHODS: Participants were 23 patients with a schizophrenia-spectrum disorder (DSM-IV criteria) and 29 healthy volunteers, who did not differ in age, sex or ethnicity. Excitatory and inhibitory systems were elicited using a temporal summation test (Peltier thermode) administered before and after activation of the diffuse noxious inhibitory control (DNIC) by means of a cold-pressor test. RESULTS: Time was a significant predictor of pain scores in controls, but not in patients. That is, pain ratings increased during the tonic thermal stimulation among controls but not in schizophrenia patients. When correlation coefficients (between time and pain ratings) for patients and controls were compared, the correlation coefficient emerged as significantly weaker in the schizophrenia group (Z=12.04; p=0.0001), suggesting a lack of sensitization in schizophrenia. DNIC was similar in magnitude in both patients and controls. CONCLUSIONS: Diminished pain sensitivity in schizophrenia may be related to abnormal excitatory mechanisms, but not to DNIC. More studies are needed to better characterize the neurophysiological and neurochemical mechanisms involved in the lack of sensitization in schizophrenia.     

Feasibility of an easy-to-use risk score in the prevention of venous thromboembolism and placental vascular complications in pregnant women: a prospective cohort of 2736 women

INTRODUCTION: Management of pregnant women at increased risk of venous thromboembolism (VTE) remains complex in the absence of an easy-to-use tool allowing individualised, risk-adapted prophylaxis. Our objective was to assess whether treatment based on risk score is feasible in these women. MATERIALS AND METHODS: A scoring system for VTE risk in pregnant women was developed, each score being associated with a specific treatment. This system was implemented in a prospective cohort of 2736 consecutive women delivered in our teaching hospital from July 2002 to June 2003. Thromboembolic and obstetrical outcomes during pregnancy and the early post-partum period were recorded. RESULTS: Treatment based on risk score was implemented in 2685 of the 2736 women included (98.1%). The scoring system identified 2431 women with no risk factor and 305 women (11%) with at least one risk factor. Eight women not at risk (0.3%, [95% CI: 0.1-0.5]) and one at risk (0.4%, [95% CI: 0-1.1]) experienced a VTE. This low event rate precluded estimation of the discriminatory power of the score. However, the benefit of the scoring system was evaluated indirectly by assessing VTE incidence in the 46 women at risk in whom it was not used (15.2%, [95% CI: 4.8-25.6]). CONCLUSIONS: Our simple scoring system offers an easily implemented procedure for risk-based VTE prophylaxis of pregnant women and the proposed therapeutic strategy appears to be effective and safe in reducing VTE. The discriminatory power of the score is currently being evaluated in a randomized, controlled trial.     

Local risk indicators – Consensus report of working group 2

In implant dentistry, plaque control and oral hygiene practices are essential to limit the risk of complication and failure in the long term. All conditions around an implant in function that influence the load and pathogenicity of the microbiota are considered local risk indicators. They concern the prosthetic suprastructure design and the possibility for the patient to easily access each implant for plaque removal. Use of cemented prostheses should be limited to avoid excess cement acting as a foreign body and leading to peri‐implant disease. The crown margins should be supramucosal, and the connection should be precise to avoid a gap between the implant and the suprastructure. Every implant system is characterised by a specific design, surface texture and connection type. These features may influence peri‐implantitis development and progression, and the clinician should consider the risk of infection when selecting an implant. The soft‐tissue conditions around the implant, the width of keratinised mucosa, and the phenotype and thickness of the mucosa are also considered major risk indicators, as the presence of any mucosal defect around an implant can increase plaque accumulation and result in tissue inflammation. The pathogenicity of the microbiota around an implant is primarily dependent on pocket depth. Deep pockets around implants should be avoided and, if present, closely monitored and/or reduced. Proximity to natural teeth presenting endodontic and/or periodontal lesions may result in implant contamination, but the influence of the type of edentulism on perio‐pathogen presence is still unclear. These local conditions around an implant have a clear influence on peri‐implant diseases development and progression, but there is still only limited evidence regarding their role as true risk indicators.     

Neonatla vestibular stimulation and mating in cerebellar mutants

Two cerebellar mutants, staggerer and reeler, and their congenic nonmutants were used in this experiment. Experimental animals were subjected to intense rotational stimulation on a tilted plane during the first 3 weeks of life, while controls were left nonstimulated. The capacity for mating, as evidenced by vaginal plugs or the occurrence of pregnancy, was assayed during two periods: between 36 and 89 days of age (Experiment A) and between 90 and 120 days of age (Experiment B). During Experiment A the mutants as well as the normals were caged inter se with partners of the opposite sex. During Experiment B the animals were caged with intact, sexually experienced partners. The animals were examined daily for evidence of mating. During Experiment A, only 3 of the 89 couples participating in this study showed evidence of mating. During Experiment B, the number of males of both strains which had mated increased significantly. The staggerer females showed a relatively high level of mating activity, whether stimulated or not. The reeler females, in contrast, rarely mated, although early stimulation significantly increased the level of sexual efficiency. The majority of the normal males and females mated, whether stimulated or not. It was concluded that massive motor-sensory stimulation in infancy, improving gait and body balance in staggerer and reeler mice, may also improve mating efficiency.     

No association between schizophrenia and homozygosity at the D3 dopamine receptor gene

The D₃ dopamine receptor gene is an important candidate gene for schizophrenia, since (because of its almost exclusive expression in the limbic system) it combines the dopamine receptor hypothesis with the limbic system hypothesis of schizophrenia. A BalI restriction fragment length polymorphism of the D₃ dopamine receptor gene has been typed in 107 schizophrenic patients and 98 normal controls from Sichuan (China). With regard to alleles or genotypes, no significant differences were obtained between controls from Europe and China, between patients and controls, and between patient subgroups and controls. These results indicate a lack of association between schizophrenia and the D₃ dopamine receptor gene in our sample. Our findings are at variance with reports of a significant excess of homozygosity at the D₃ dopamine receptor gene in schizophrenic patients from Wales (United Kingdom) and Alsace (France). In conclusion, further studies will be needed with larger samples of patients from Wales and Alsace as well as with samples of different racial groups to prove or disprove the initial positive association between schizophrenia and genotypes of the D₃ dopamine receptor gene. © 1993 Wiley-Liss, Inc.     

Absent chondrodysplasia punctata in a male with an Xp terminal deletion involving the putative region for CDPX1 locus

This is a follow-up report on a male patient with a 46, Y, r(X) karyotype. Although he had no clinico-radiological features of X-linked recessive chondrodysplasia punctata (CDPX1), molecular studies revealed an Xp terminal deletion involving the putative region for the CDPX1 locus (PABX-DXS31). We suspect that the absence of CDPX1 may be attributable to the nature of the disease and the extreme short stature of the patient (mean – 5.6 S.D.). © 1993 Wiley-Liss, Inc.     

Genetic basis of nonresponse to hepatitis B vaccine in hemodialyzed patients

Genetic factors are implicated in the response of normal subjects to hepatitis B vaccine. The aim of our study was to investigate if HLA Class I and II proteins could participate in a nonresponse to this vaccine in immunocompromised, namely hemodialyzed, patients. One hundred and seven hemodialyzed patients (68 men and 39 women, mean age 35 years) were vaccinated with Pasteur Hevac B vaccine, with a mean delay of 2 months following the onset of chronic hemodialysis. Patients were considered nonresponders when their serum antiHBs remained less than 10 mUI/ml on at least two occasions within the 12 months following the vaccination. HLA-A, B and DR antigens were determined by complement-dependent microlymphotoxicity. Ninety patients (84%) were responders and 17 (16%) nonresponders. The HLA-A1, B8 and DR3 frequency was higher in nonresponders (35, 35 and 44%, respectively) than in responders (18, 4 and 14%, respectively). The extended haplotype HLA-A1, B8, DR3 was more frequent in the former (19%) than in the latter (2%) (p less than 0.03). There was only one female within the nonresponders (6%) as compared to 37 (41%) in the responders (p less than 0.05). We conclude that genetic determinants (sex and HLA markers) play a critical role in the induction of an antiHBs immune response in both immunoincompetent hemodialyzed patients and normal immunocompetent hosts.     

FDG uptake at the bronchial stump after curative lobectomy for non-small cell lung cancer

Purpose

Focal areas of FDG uptake may occur at the bronchial stump following curative lobectomy for non-small-cell lung carcinoma (NSCLC), even in the absence of suspicious CT changes. The purpose of our study was to investigate the significance of such PET/CT findings.

Methods

FDG-PET/CT scans performed in 54 patients after lobectomy for NSCLC were reviewed. The presence of focal areas of FDG uptake at the bronchial stump, associated CT abnormalities, SUVmax, and normalized SUV (SUVnorm = SUVmax/mean liver SUV) were recorded. Final diagnosis was based on biopsy or imaging follow-up.

Results

Focal areas of FDG uptake at the bronchial stump were detected in 30 patients (56 %). Mean SUVmax was 4.0?±?1.9 (range; 2.2–12.1) and mean SUVnorm was 1.8?±?0.8 (range; 0.9–4.5). Biopsy showed recurrence in two patients. In these patients, SUVnorm was respectively 4.4 and 4.5 (with SUVmax of 8.8 and 12.1), whereas SUVnorm was lower than 4.0 in those without recurrence, with mean SUVnorm of 1.6?±?0.5 (range; 0.9–3.4) and mean SUVmax of 3.6?±?0.9 (range; 2.2–5.8). The CT component of the PET/CT revealed ill-defined peribronchial soft tissue opacity only in both patients with recurrence.

Conclusion

FDG uptake at the bronchial stump is a frequent finding after pulmonary lobectomy. Moderate levels of FDG uptake (i.e., SUVnorm?<?4.0) without corresponding abnormal CT findings might be a dual criterion for diagnosing benign post-surgical changes.