Molecular typing of Mycobacterium tuberculosis based on variable number of tandem DNA repeats used alone and in association with spoligotyping

Fingerprinting based on variable numbers of tandem DNA repeats (VNTR), a recently described methodology, was evaluated for molecular typing of Mycobacterium tuberculosis in an insular setting. In this study, VNTR fingerprinting was used alone or as a second-line test in association with spoligotyping, double-repetitive-element PCR (DRE-PCR), and IS6110 restriction fragment length polymorphism (RFLP) analysis, and the discriminatory power for each method or the combination of methods was compared by calculating the Hunter-Gaston discriminative index (HGI). The results obtained showed that in 6 out of 12 (50%) cases, VNTR-defined clusters were further subdivided by spoligotyping, compared to 7 out of 18 (39%) cases where spoligotyping-defined clusters were further subdivided by VNTR. When used alone, VNTR was the least discriminatory method (HGI = 0.863). Although VNTR was significantly more discriminatory when used in association with spoligotyping (HGI = 0.982), the combination of spoligotyping and DRE-PCR (HGI = 0.992) was still the most efficient among rapid, PCR-based methodologies, giving results comparable to IS6110 RFLP analysis. Nonetheless, VNTR typing may provide additional phylogenetical information that may be helpful to trace the molecular evolution of tubercle bacilli.     

Autoradiographic mapping of the opioid receptor-like 1 (ORL1) receptor in the brains of mu-, delta- or kappa-opioid receptor knockout mice

The opioid receptor-like 1 (ORL1) receptor shares a high degree of sequence homology with the classical mu-, delta- and kappa-opioid receptors and a functional mutual opposition between these receptors has been suggested. To further address this possible interaction we have used mu-, delta- and kappa-opioid receptor knockout mice to determine autoradiographically if there are any changes in the number or distribution of the ORL1 receptor, labelled with [(3)H]nociceptin, in the brains of mice deficient in each of the opioid receptors. An up-regulation of ORL1 expression was observed across all brain regions in delta-knockouts with cortical regions typically showing a 15-30% increase in binding that was most marked in heterozygous mice. In contrast, ORL1 receptor expression was down-regulated in virtually all brain structures in heterozygous kappa-knockouts although the magnitude of this change was not as great as for the delta-knockouts. No significant alterations in ORL1 receptor expression were observed across brain regions in mu-receptor knockout mice and there were no qualitative differences in ORL1 receptor expression in any groups.These data suggest there are interactions between the ORL1 system and the classical opioid receptors and that the interactions are receptor-specific. The greater differences observed in heterozygous mice suggest that these interactions might be most relevant when there is only partial loss of receptor function.     

Characterization of Finnish Mycobacterium tuberculosis isolates by spoligotyping

The molecular epidemiology of tuberculosis (TB) in Finland was studied by spoligotyping 380 Mycobacterium tuberculosis isolates. The isolates were obtained during a 1-year study period from July 2000 to June 2001 and represented 90% of new M. tuberculosis findings by culture in the whole country during the study period. The spoligotyping results were compared to the World Spoligotyping Database of the Institut Pasteur de Guadeloupe, which contains data from >14,000 M. tuberculosis isolates obtained worldwide. A total of 138 different spoligotypes were identified among the 380 M. tuberculosis isolates. Thirty-eight (10%) isolates had unique spoligotypes, while 342 (90%) isolates belonged to 100 shared types. The four most common spoligotypes caused approximately one-third of the Finnish TB cases. Forty-seven of the 138 (34.1%) spoligotypes and 61 (16.1%) of the 380 M. tuberculosis isolates had spoligotypes that had not been previously reported. Only four (1.1%) patients were infected with an isolate belonging to the Beijing genotype. The characterization of Finnish M. tuberculosis isolates by spoligotyping shows that ubiquitous spoligotypes were common, but many spoligotypes specific to Finland were also found. However, Beijing family isolates were rarely encountered, although this spoligotype is predominant in our eastern and southern neighbors.     

Zinc alleviates pain through high-affinity binding to the NMDA receptor NR2A subunit

Zinc is abundant in the central nervous system and regulates pain, but the underlying mechanisms are unknown. In vitro studies have shown that extracellular zinc modulates a plethora of signaling membrane proteins, including NMDA receptors containing the NR2A subunit, which display exquisite zinc sensitivity. We created NR2A-H128S knock-in mice to investigate whether Zn2+-NR2A interaction influences pain control. In these mice, high-affinity (nanomolar) zinc inhibition of NMDA currents was lost in the hippocampus and spinal cord. Knock-in mice showed hypersensitivity to radiant heat and capsaicin, and developed enhanced allodynia in inflammatory and neuropathic pain models. Furthermore, zinc-induced analgesia was completely abolished under both acute and chronic pain conditions. Our data establish that zinc is an endogenous modulator of excitatory neurotransmission in vivo and identify a new mechanism in pain processing that relies on NR2A NMDA receptors. The study also potentially provides a molecular basis for the pain-relieving effects of dietary zinc supplementation.     

Facteurs de risque de pose de sonde gastrique en chirurgie colorectale programmée,dans le cadre d’un programme de réhabilitation postopératoire : une analyse multivariée

Objective

Nasogastric tube placement (NTP) is no more systematically recommended in patients scheduled for elective colorectal surgery but could be necessary in case of postoperative vomiting. The aim of this study was to determine independent risk factors for NTP after colorectal surgery.

Patients and methods

We performed an observational study including 290 patients scheduled for elective colorectal surgery included in an enhanced recovery programme: immunonutrition, thoracic epidural analgesia, antiemetic prophylaxis, respiratory physiotherapy, absence of NT and drainage, forced mobilization and oral nutrition. The main outcome was the occurrence of vomiting requiring NTP. Univariate analysis included: age, sex, BMI, American Society of Anesthesiologist Physical Status Classification System (ASA), duration of surgery, epidural analgesia, and mobilization, intraoperative fluid, temperature, laparotomy, use of droperidol, parenteral nutrition, stoma, diabetes, hypertension or coronary disease, COPD, type of surgery. A logistic regression was performed to determine independent risk factors of NTP.

Results

Among the 290 patients included, 277 were analyzed. The incidence of NTP was 10.5% (95%CI [7.4–14.6%]). Univariate analysis documented BMI, low temperature in PACU (< 35 °C), ASA scores, duration of surgery and epidural analgesia, rectal and sigmoid resections, diabetes, transfusion, no use of droperidol, duration of mobilization, conversion to laparotomy. Three independent risk factors were associated with NTP: temperature in SSPI < 35.5 °C (OR: 14.49; IC95% [4.52–45.45], P < 0.0001), BMI < 21 kg/m² (8.40; [1.99–35.71], P = 0.0038) and lack of postoperative droperidol administration (3.37 [1.02–11.39], P = 0.04).

Conclusions

After colorectal surgery tolerance to rapid oral feeding is impaired by denutrition and postoperative hypothermia. The combined used of postoperative droperidol should also be considered to avoid postoperative NTP.     

Two additional cases of excessive extension of sensory blockade after intrathecal sufentanil for labor analgesia

Combined spinal-epidural anesthesia (CSE) is an effective technique with rapid onset of labor analgesia. We describe two cases of excessive cephalad spread of sensory blockade without motor blockade in two parturients in spontaneous labor with CSE. The patients received sufentanil 5 microg intrathecally with 1.25 mg bupivacaine. Spinal injection produced dyspnea and extension of sensory blockade to cervical or facial level without fetal consequences. We conclude that the risk of these side-effects previously described with the 10 microg dose persists for lower sufentanil spinal doses.     

Increased functional coupling of the mu opioid receptor in the anterior insula of depressed individuals

The mu opioid receptor (MOR) is a G protein-coupled receptor that plays an essential role in reward and hedonic processes, and that has been implicated in disorders such as depression and addiction. Over the last decade, several brain imaging studies in depressed patients have consistently found that dysregulation of MOR function occurs in particular in the anterior insular cortex, an important brain site for the perception of internal states and emotional regulation. To investigate molecular mechanisms that may underlie these effects, here we assessed genetic polymorphisms, expression, and functional G-protein coupling of MOR in a large post-mortem cohort (N = 95) composed of depressed individuals who died by suicide, and healthy controls. Results indicated that depression, but not comorbid substance use disorder or acute opiate consumption, was associated with increased MOR activity. This effect was partly explained by a specific increase in expression of the inhibitory alpha G-protein subunit GNAI2. Consistent with previous neuroimaging studies, our findings support the notion that enhanced endogenous opioidergic tone in the anterior insula may buffer negative affective states in depressed individuals, a mechanism that could potentially contribute to the antidepressant efficacy of emerging opioid-based medications.Subject terms: Depression, Depression