Arrangement of Excitatory Synaptic Inputs on Dendrites of the Medial Superior Olive

Neurons in the medial superior olive (MSO) detect 10 µs differences in the arrival times of a sound at the two ears. Such acuity requires exquisitely precise integration of binaural synaptic inputs. There is substantial understanding of how neuronal phase locking of afferent MSO structures, and MSO membrane biophysics subserve such high precision. However, we still lack insight into how the entirety of excitatory inputs is integrated along the MSO dendrite under sound stimulation. To understand how the dendrite integrates excitatory inputs as a whole, we combined anatomic quantifications of the afferent innervation in gerbils of both sexes with computational modeling of a single cell. We present anatomic data from confocal and transmission electron microscopy showing that single afferent fibers follow a single dendrite mostly up to the soma and contact it at multiple (median 4) synaptic sites, each containing multiple independent active zones (the overall density of active zones is estimated as 1.375 per μm²). Thus, any presynaptic action potential may elicit temporally highly coordinated synaptic vesicle release at tens of active zones, thereby achieving secure transmission. Computer simulations suggest that such an anatomic arrangement boosts the amplitude and sharpens the time course of excitatory postsynaptic potentials by reducing current sinks and more efficiently recruiting subthreshold potassium channels. Both effects improve binaural coincidence detection compared with single large synapses at the soma. Our anatomic data further allow for estimation of a lower bound of 7 and an upper bound of 70 excitatory fibers per dendrite.SIGNIFICANCE STATEMENT Passive dendritic propagation attenuates the amplitude of postsynaptic potentials and widens their temporal spread. Neurons in the medial superior olive, with their large bilateral dendrites, however, can detect coincidence of binaural auditory inputs with submillisecond precision, a computation that is in stark contrast to passive dendritic processing. Here, we show that dendrites can counteract amplitude attenuation and even decrease the temporal spread of postsynaptic potentials, if active subthreshold potassium conductances are triggered in temporal coordination along the whole dendrite. Our anatomic finding that axons run in parallel to the dendrites and make multiple synaptic contacts support such coordination since incoming action potentials would depolarize the dendrite at multiple sites within a brief time interval.     

Reliability of the English version of the painDETECT questionnaire

Background: The painDETECT questionnaire (PD-Q) has been used widely for the identification of neuropathic pain (NeP); however, the reliability of the English version of the PD-Q has never been investigated.

Objective: This study aimed to determine the reliability of the PD-Q pre- (T0) and immediately post- (T1) clinical consultation and at one-week follow-up (T2).

Methods: We recruited 157 patients attending a Neurosurgery Spinal Clinic and Pain Management Department. Minor changes to PD-Q instructions were made to facilitate patient understanding; however, no changes to individual items or scoring were made. Intraclass correlation coefficients (ICCs) were used to assess the reliability of PD-Q total scores between T0–T1 and T0–T2; weighted kappa (κ) was used to assess the agreement of PD-Q classifications (unlikely NeP, ambiguous, likely NeP) between all time-points. To ensure stability of clinical pain, patients scoring ≤2 or ≥6 on the Patient Global Impression Scale (PGIC) at T2 were excluded from the T0–T2 analysis.

Results: Accounting for missing data and exclusions (change in PGIC score), data for 136 individuals (mean [SD] age: 56.8 [15.2]; 54% male) was available, of whom n?=?129 were included in the T0–T1 and n?=?69 in the T0–T2 comparisons. There was almost perfect agreement between the PD-Q total scores at T0–T1 time-points (ICC 0.911; 95% CI: 0.882–0.941) and substantial agreement at T0–T2 (ICC 0.792; 95% CI: 0.703–0.880). PD-Q classifications demonstrated substantial agreement for T0–T1 (weighted κ: 0.771; 95% CI: 0.683–0.858) and for T0–T2 (weighted κ: 0.691; 95% CI: 0.553–0.830). Missing data was accounted in 13% of our cohort and over 42% of our patients drew multiple pain areas on the PD-Q body chart.

Conclusion: The English version of the PD-Q is reliable as a screening tool for NeP. The validity of the questionnaire is still in question and has to be investigated in future studies.     

Life quality of patients undergoing liver transplantation

Abstract The aim of this study was to assess the life quality of a group of Datients who had undergone liver transplantation using (1) a psychological test to evaluate family relations, work activity, emotional state and social relationships; (2) the quantification of hospital dependence and degree of fitness for work. Included in the study were 32 patients using the following criteria: diagnosis of hepatic cirrhosis and minimum posttransplant follow-up of 6 months. The average age of the study population was 44.8 ± 10.5 years; there were 23 males and 9 females, with an average follow-up of 15 months. The psychological test used was the Quality of Life Scale (QLS) which consists of 21 items each scoring from 1 to 6 points. The questionnaire was completed before transplantation by all the patients, and after transplantation by 32 patients at 6 months, 20 at 12 months and 12 at 24 months. Hospital dependence was evaluated by the number of admissions and number of days per admission. Lastly, we compared fitness for work before transplantation and at 1 and 2 years after transplantation. The QLS test showed a post-transplant improvement in the four aspects assessed, particularly in the personal aspects (emotions and family) ( P < 0.001). Hospital dependence following liver transplantation decreased significantly compared with the pretransplant situation ( P < 0.01). Finally, the post-transplant percentage of unfitness for work decreased with time, reaching a significant differences 2 years after transplantation ( P < 0.05). /     

Placental transfer of fluoride in Holstein cows.

Placental transfer of fluoride was studied in 40 Holstein cows and related to a previous 7 1/2 y study for comparative purposes. Animals were randomly assigned to fluoride dosage groups of control, 0.51, 1.31 or 2.66 sodium fluoride/d (10, 25, 50 or 100 ug/g feed). Each animal received the dose daily via gelatin bolus for 4-14 d prior to parturition. Maternal heparinized blood samples were collected before dosing and after parturition. Placental cotyledon and calf blood samples were collected from each animal immediately after parturition. Maternal and calf plasma and placental cotyledon fluorine concentrations were determined. Increased levels of fluoride given to pregnant cows resulted in significantly increased (p less than 0.05) maternal plasma and placental cotyledon fluorine concentrations. Calf plasma fluorine concentrations at birth did not significantly increase in relation to the fluoride treatment level of dams. The data support the concept that under normal circumstances in cattle there is a partial placental barrier to fluoride that operates to limit fluoride concentrations in the fetal circulation and tissues.     

Management of the perineal wound following abdominoperineal resection: prospective study of three methods.

A prospective study was made of three procedures for treating the perineal wound and presacral cavity in 102 patients undergoing abdominoperineal excision for cancer of the rectum: (1) packing of the presacral space after suture of the pelvic peritoneum; (2) suture of the pelvic peritoneum and perineal wound, leaving two drains through the perineum; and (3) no suture of the pelvic peritoneum, and primary closure of the perineal wound, leaving drains through the abdomen for physiological saline irrigation. The parameters analysed were incidence of infection, primary healing of the perineum, extraperineal complications and mean hospital stay. Primary healing of the perineum was best with method 3, and overall incidence of infection highest with method 2. There were no differences between the methods with regard to extraperineal complications. Hospital stay was shortest with method 3.     

Restructuring the multi-professional organization: professional identity and adjustment to change in a public hospital

The present study explored the multiple identities held by health professionals in a large public hospital that was experiencing organizational change that involved the transition from the traditional use of professional hierarchies to the use of new clinical teams. Consistent with predictions from social identity theory and research, the results of an organization-wide survey (N = 615) reveal the protective role of identification with professional departments during change that threatened group status. Professional departments were the preferred target of identification of employees, and employees who preferred this target reported a stronger sense of identification. Also consistent with our predictions, employees who were members of higher status groups reported greater job satisfaction, higher levels of openness to organizational change, and reduced levels of change-related uncertainty. These results were more pronounced for employees who identified with their professional department. Implications for managing multiple identities during organizational transition are discussed.     

Antimicrobial Activities of BMS-284756 Compared with Those of Fluoroquinolones and β-Lactams against Gram-Positive Clinical Isolates

The in vitro antibacterial activity of BMS-284756 was compared to those of ciprofloxacin, gatifloxacin, moxifloxacin, ceftriaxone, imipenem, piperacillin-tazobactam, and amoxicillin-clavulanic acid against 492 gram-positive clinical isolates. BMS-284756 was the most-active agent against Streptococcus pneumoniae, Streptococcus viridans, beta-hemolytic streptococci, methicillin-sensitive and -resistant Staphylococcus aureus, methicillin-sensitive and -resistant coagulase-negative staphylococci, and enterococci.