Actions of subtype-specific purinergic ligands on rat spiral ganglion neurons

In a previous study we showed that, in rat spiral ganglion neurons (SGNs), the adenosine 5'-triphosphate (ATP)-evoked currents were a combination of the activation of ionotropic receptors (the first fast current) and the activation of metabotropic receptors which secondarily opened non-selective cation channels. These two conductances imply the involvement of different receptor subtypes. In the present study, we tested three subtype-specific purinergic ligands: alpha,beta-methylene ATP (a;pha,beta-meATP) for P2X receptors, uridine 5'-triphosphate (UTP) for P2Y receptors and 2'-3'-O-(4-benzoylbenzoyl) ATP (Bz-ATP) for P2Z (P2X(7)) receptors. Application of 100 microM alpha,beta-meATP did not trigger any significant change in membrane conductance, while the SGNs were responsive to ATP. Pressure application of UTP (100 microM, 1 s) evoked an inward current averaging 344+/-169 pA at a holding potential of -50 mV. The conductance developed after a latency averaging 1.5+/-0.6 s, took 4-6 s to peak and reversed slowly within 15-30 s. The current-voltage curve reversed near 0 mV, suggesting a non-selective cation conductance, like the second component of the ATP conductance. Bz-ATP evoked an inward current which developed without latency, was sustained during ligand application and was rapidly inactivated at the end of application: the same characteristics as the first component of the ATP-evoked current. The Bz-ATP conductance reversed around -10 mV, indicating also a non-selective cation conductance. These results suggest that, in SGNs, ATP acts via two different receptor subtypes, ionotropic P2Z receptors and metabotropic P2Y receptors, and that these two receptor subtypes can assume different physiological roles.     

Measuring quality of life in multiple sclerosis patients with urinary disorders using the Qualiveen questionnaire

OBJECTIVES: To assess the impact of urinary disorders on multiple sclerosis (MS) patients' health-related quality of life and to examine the cross-sectional construct validity of Qualiveen, a questionnaire originally developed for spinal cord injury patients with urinary disorders, in patients with MS. DESIGN: Cohort study. SETTING: Neurourodynamic units in 3 French university hospitals. PARTICIPANTS: Patients with MS (N=197). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: We tested predictions about the relationships among clinical features, the French version of the Multiple Sclerosis Quality of Life questionnaire (SEP-59), the Expanded Disability Status Scale (EDSS), and the 4 domains of the 30-item Qualiveen. RESULTS: Cross-sectional correlations among the 4 Qualiveen domains and type (range, .36-.54), number of symptoms (range, .23-.50), and severity of incontinence (.39-.68) were generally moderate to strong. The SEP-59 bowel and bladder function domain showed moderate to strong relationships with the Qualiveen (range, .39-.59). Relationships with other SEP-59 domains were generally weak (range, .22-.35), and with the EDSS they were very weak. Predictions proved generally accurate (weighted kappa=.61). CONCLUSIONS: Our data supported the Qualiveen's validity as a discriminative instrument for use with patients with MS. Further studies should explore the Qualiveen's longitudinal validity and responsiveness.     

Nosocomial bloodstream infection and clinical sepsis

Primary bloodstream infection (BSI) is a leading, preventable infectious complication in critically ill patients and has a negative impact on patients' outcome. Surveillance definitions for primary BSI distinguish those that are microbiologically documented from those that are not. The latter is known as clinical sepsis, but information on its epidemiologic importance is limited. We analyzed prospective on-site surveillance data of nosocomial infections in a medical intensive care unit. Of the 113 episodes of primary BSI, 33 (29%) were microbiologically documented. The overall BSI infection rate was 19.8 episodes per 1,000 central-line days (confidence interval [CI] 95%, 16.1 to 23.6); the rate fell to 5.8 (CI 3.8 to 7.8) when only microbiologically documented episodes were considered. Exposure to vascular devices was similar in patients with clinical sepsis and patients with microbiologically documented BSI. We conclude that laboratory-based surveillance alone will underestimate the incidence of primary BSI and thus jeopardize benchmarking.     

Glucose appearance in the peripheral circulation and liver glucose output in men after a large 13C starch meal

BACKGROUND: Glucose absorption from starchy food has only been described with small amounts ingested ( approximately 20-75 g). OBJECTIVE: Our aim was to describe total plasma (Ra) and exogenous glucose (Ra(exo)) appearance, glucose release from the liver (HGP), and the metabolic response after ingestion of 5 g polished or parboiled rice/kg body mass. DESIGN: Gas exchange and urea excretion were monitored in 8 healthy subjects before (3.5 h) and after (8 h) ingestion of rice intrinsically labeled with (13)C; [6,6-(2)H(2)]glucose was infused for the measurement of Ra, Ra(exo), and HGP. RESULTS: Changes in plasma glucose, insulin, lactate, and free fatty acids and the increase in Ra(exo) and Ra ( approximately 200%) and the decrease in HGP ( approximately 90%) were not significantly different (P > 0.05) after ingestion of either rice. Glucose oxidation was not significantly different (111.6 +/- 8.2 compared with 89.0 +/- 11.3 g; P = 0.13), but fat oxidation was significantly lower (9.9 +/- 1.7 compared with 21.3 +/- 4.0 g; P < 0.05) after parboiled than after polished rice. The percentage of the glucose load that appeared in the circulation over 8 h was not significantly different after ingestion of polished (70.4 +/- 4.5%) or parboiled (63.8 +/- 2.0%) rice (P > 0.05). CONCLUSION: Although the starch in parboiled rice is less susceptible to digestion in vitro, exogenous glucose availability was not significantly different after ingestion of large amounts of polished or parboiled rice. Glucose absorption remains incomplete 8 h after ingestion of both types of rice.     

Extensive unilateral iliofemoral occlusions: durability of four techniques of arterial reconstructions

In patients with long unilateral iliofemoral occlusive disease unfit for percutaneous transluminal angioplasty (PTA), most surgeons would choose some type of prosthetic bypass (aortounifemoral, iliofemoral or cross over). All these bypasses would provide excellent early results, but some may not be sufficient in patients with a good life expectancy who also need durable patency. The purpose of the study was to compare the long-term results of four types of arterial reconstructions. Over 20 years, 468 unilateral iliofemoral occlusions were treated primarily by one of the following techniques: aortounifemoral bypass (group 1, n = 108), iliofemoral bypass (group 2, n = 144), crossover bypass (group 3, n = 108), and iliofemoral endarterectomy (group 4, n = 108). Patients in group 3 presented with more severe comorbidities, and patients in group 4 had more superficial femoral artery occlusions. All data were prospectively registered after discharge and during the survey. Patency was assessed with duplex ultrasonography on a yearly basis. Perioperative complications and death rates were similar in all groups. The standard error was less than 10% for a period of over 10 years in all groups, except for group 3, in which it was more than 10% after 8 years. At 8 years, primary patency rates in groups 1, 2, 3, and 4 were 79%, 66%, 74%, and 89%, respectively. The difference was significant between group 4 and group 2 (p < .02) and group 3 (p < .01). Secondary patency and limb salvage rates were not significantly different. In this study, for an equal perioperative risk, the primary patency rates of iliac endarterectomies were superior to those of the other techniques, suggesting that these procedures should be the first choice in patients in good physical condition. Iliofemoral bypasses and crossover bypasses needed much more redo surgery. A crossover bypass should be reserved for patients who are unfit for an abdominal approach or who have a short life expectancy.