A wireless multi-channel neural amplifier for freely moving animals

Conventional neural recording systems restrict behavioral experiments to a flat indoor environment compatible with the cable that tethers the subject to recording instruments. To overcome these constraints, we developed a wireless multi-channel system for recording neural signals from rats. The device takes up to 64 voltage signals from implanted electrodes, samples each at 20 kHz, time-division multiplexes them into one signal and transmits that output by radio frequency to a receiver up to 60 m away. The system introduces <4 μV of electrode-referred noise, comparable to wired recording systems, and outperforms existing rodent telemetry systems in channel count, weight and transmission range. This allows effective recording of brain signals in freely behaving animals. We report measurements of neural population activity taken outdoors and in tunnels. Neural firing in the visual cortex was relatively sparse, correlated even across large distances and was strongly influenced by locomotor activity.     

Serum testosterone, dihydrotestosterone, luteinizing hormone and follicle-stimulating hormone versus prostate specific antigen in patients with localized prostate adenocarcinoma who underwent radical prostatectomy. Radioimmunoassays measurements

The relation of steroid hormones (SH) with carcinogenesis is not well understood. There is a variation of opinions among researchers about the prognostic value of serum SH in patients with localized prostate cancer (PC). The aim of this was to study serum SH in patients with localized PC before and after radical prostatectomy (RP). Seventy patients with mean age 67+/-8 years, were studied. The diagnosis was confirmed by histology after a biopsy. None of the patients was submitted to hormonal treatment or radiotherapy prior to RP. Serum testosterone (TST), dihydrotestosterone (DHT), luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels were examined prior RP and one year following RP, by radioimmuno assay (RIA) or immunoradiometric assay (IRMA) methods. Based on serum PSA levels before and one year after RP, 66 of the patients did not have biochemical recurrence while 4 patients developed biochemical recurrence due to residual disease and were treated with flutamide and a LH-RH analogue. In the group of 66 patients there was a statistically significant increase in serum TST (P<0.001), LH (P=0.004) and FSH (P<0.001), and statistically significant decrease in serum DHT (P<0.001). In the four patients with biochemical recurrence, TST increased and serum DHT, LH and FSH decreased. In this group the reduction of DHT and LH, FSH were due to treatment with flutamide and a LH-RH analogue respectively. Our findings suggest that after RP increase of serum LH and FSH may have caused an increase in serum TSH and a decrease of serum DHT. If those changes are due to the hypothalamic-pituitary axis it may be that the prostate neoplasm before RP may have secreted a substance that induced a negative feedback to the pituitary gonadotrophin secretion, which was unrelated to varying serum PSA levels.     

Heterotopic ossification of the knee joint in intensive care unit patients: early diagnosis with magnetic resonance imaging

Introduction  

Heterotopic ossification (HO) is the formation of bone in soft tissues. The purpose of the present study was to evaluate the magnetic resonance imaging (MRI) findings on clinical suspicion of HO in the knee joint of patients hospitalised in the intensive care unit (ICU).     

Association of depressive symptoms with coagulation factors in young healthy individuals

BACKGROUND: Depression has been reported to be an independent risk factor for coronary heart disease (CHD). We investigated the association of depressive symptoms with lipids and coagulation factors in young individuals free of CHD. METHODS: We recruited 1073 young healthy individuals candidates for military academies (mean age=18.4+/-0.8 years, males 762) in whom the presence of depressive symptoms was assessed by using the depression scale of Minnesota Multiphasic Personality Inventory test. Total cholesterol, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, lipoprotein (a), fibrinogen, factors VII, VIII and X were measured. RESULTS: The depression score ranged from 22 to 90. The participants were divided into quartiles according to the depression score. Three hundred twenty-two subjects were classified in the upper quartile (score>48) and 269 in the lower quartile (score<37) of the depression score. Factor VII (102.95+/-24 versus 98.5+/-20%) and X levels (92+/-11 versus 89.7+/-10%) were significantly higher in individuals in the upper quartile compared to the lower quartile of the depression score. In a logistic regression model with factor VII as dependent variable (upper versus lower quartile) and depression score, age, gender, body mass index, exercise and smoking as predictor variables, depression was an independent predictor of factor VII levels with an adjusted odds ratio for high levels of factor VII of 1.05 (95% confidence interval 1.008-1.09, p=0.01). Factor VII levels were associated with triglycerides (r=0.21, p=0.001) while factor X with triglycerides (r=0.22, p<0.001) and cholesterol levels (r=0.12, p<0.001). CONCLUSIONS: Depressed mood is associated with a hypercoagulant profile as it is expressed by the higher levels of coagulation factors VII and X. This might partially explain the higher propensity for CHD of people with depressive symptoms.     

Phase I study of concomitant chemoradiotherapy with paclitaxel, fluorouracil, gemcitabine, and twice-daily radiation in patients with poor-prognosis cancer of the head and neck.

PURPOSE: We previously demonstrated high locoregional control, in patients with poor-prognosis head and neck cancer (HNC), using paclitaxel, 5-fluorouracil, hydroxyurea, and concomitant hyperfractionated radiotherapy. In the present phase I trial, gemcitabine, a novel antimetabolite with strong radiation-enhancing activity, replaces hydroxyurea. We sought to determine the recommended phase II dose and clinical efficacy in poor-prognosis HNC patients. EXPERIMENTAL DESIGN: Seventy-two patients enrolled. Eligibility criteria included recurrent or second primary HNC, metastases or expected 2-year survival <20%. Chemoradiotherapy consisted of 5-fluorouracil, 600 mg/m(2)/d, for 5 days; paclitaxel, 100 mg/m(2) on Day 1; and concurrent 1.5 Gy twice-daily radiation for 5 days. Gemcitabine was dose escalated, 50-300 mg/m(2) on day 1. Cycles repeated every 14 days until the completion of chemoradiation. Dose-limiting toxicities (DLTs) included: neutropenic fever; grade > or =4 neutropenia or thrombocytopenia for >4 days; grade > or =4 mucositis or dermatitis for >7 days; or grade 3 toxicity necessitating chemotherapy dose reductions. Non-DLT dose reductions in 5-fluorouracil and/or paclitaxel were allowed. RESULTS: Seventy-nine percent of assessable patients experienced a clinical response. Five-year actuarial survival is 33.0%, and locoregional control is 61.4%. The recommended phase II dose of gemcitabine in this regimen is 100 mg/m(2) during cycles 1-5 (1 of 7 patients with DLT) or 200 mg/m(2) delivered only during cycles 3-5 (3 of 19 with DLT). Grades 3 and 4 mucositis (56 and 21%, respectively) and dermatitis (25 and 21%, respectively) were common. CONCLUSIONS: Gemcitabine, 5-fluorouracil, paclitaxel, and twice-daily radiation, delivered on alternating weeks, is active in patients with poor-prognosis HNC, although severe mucositis limits the clinical applicability of this regimen. Refinements in radiotherapy, including intensity-modulated radiation therapy, may improve the tolerance for this regimen.