The role of external ventricular drainage for the management of posterior cranial fossa tumours: a systematic review

Neurosurgical Review - Posterior cranial fossa tumours frequently develop hydrocephalus as first presentation in up to 80% of paediatric patients and 21.4% of adults, although it resolves after...     

Beta-endorphin concentrations both in plasma and in cerebrospinal fluid in response to acute painful stimuli

The beta-endorphin-like-immunoreactivity (beta-ELI) has been evaluated both in plasma and in cerebrospinal fluid (CSF) in 30 patients during trans-sphenoidal surgery. Blood and liquoral samples were collected in five conditions: (1) "reference", (2) "pain", (3) "analgesia", (4) "end", and (5) "24th hour". A significant rise of both plasma and liquoral beta-ELI levels (p less than 0.00001 and p less than 0.08, respectively) when compared to basal ones occurred following the painful stimulation due to the divarication of the nasal mucosa by speculum. A significant decrease (p less than 0.01) was noticed for plasma concentrations at the third sample followed by a new significant increase at the end of the operation, (p less than 0.05 when compared to the third sample and p less than 0.01 when compared to the reference sample). In CSF, beta-ELI levels decreased at the third sample (p less than 0.01 when compared to the painful levels) and at the end of surgery (p less than 0.01, p less than 0.01 and p less than 0.05 vs first, second and third samples, respectively). Twenty-four hours after surgery either plasma and liquoral beta-ELI levels decreased (p less than 0.05). The modifications of the opiatergic system after acute painful stimuli should be, hence, characterized by an early rise followed by a progressive decrease of beta-ELI concentrations. The increase of plasma beta-ELI levels, at the end of surgery, could be due to pituitary manipulation with massive release in the peripheral blood.     

Two-pulse monocular and binocular interactions at the differential luminance threshold

Interaction between two pulses at the differential luminance threshold was studied for stimuli pairs presented to the same eye or to opposite eyes with an interocular delay. With monocular stimuli, the results replicated the earlier observations by Ikeda (1965) and Rashbass (1970) indicating linear interaction followed by rectification occurring at about 50-60 msec into the integration epoch. Binocular results were different, in accord with observations made in the contrast domain by Green and Blake (1981). Binocular stimuli of opposite polarity showed no cancellation. Binocular facilitation at threshold was found when either the stimuli of the same sign (+ + or - -) occurred with little interocular delay (stimulus onset asynchrony, SOA less than 15 msec), or the stimuli of the opposite sign (+ - or - +) were presented with an interocular delay between 15 and 100 msec SOA; the latter effect was at maximum with flashes 50 msec in duration presented with 50 msec interocular SOA. These results imply that binocular interaction takes place between rectified internal effects of luminance pulses. From the two-channel binocular model of Cogan (1987), binocular facilitation is attributed to the "fused" response derived from multiplicative excitation between same-sign (half-wave rectified), internal pulse responses. The absence of cancellation between simultaneous opposite-sign dichoptic stimuli is attributed to the "either-eye" binocular process dealing with full-wave rectified internal pulse responses to transient stimuli.     

Studies on the degenerative and regenerative phenomena occurring after transection and repair of the sciatic nerve in rats: effects of acetyl-L-carnitine

The effects of acetyl-L-carnitine on some degenerative and regenerative phenomena following sciatic nerve transection in rats, were studied. In Experiment 1, acetyl-L-carnitine was administered intraperitoneally at the dose of 50 mg/kg/day for 28 and 56 days following transection and microsurgical repair of the sciatic nerve. On day 56, the acetyl-L-carnitine-treated rats showed a significantly (p less than 0.05) better motor recovery ("clinical assessment") of the peroneal component of the sciatic nerve than the control rats. Twenty-eight days after nerve repair, the acetyl-L-carnitine-treated rats showed a significantly higher (p less than 0.05) number of myelinated axons in the postlesional nerve stump than control rats. Finally, the treated rats had a significantly lower (p less than 0.05) presence of atrophic fibres in the extensor digitorum longus muscle. In Experiment 2 the sciatic nerve was cut. To prevent spontaneous regeneration, a metallic clip was applied to the distal nerve stump and then the nerve stumps were positioned in different anatomical compartments. After surgery, a group of rats was treated with acetyl-L-carnitine dissolved in the drinking water (75 mg/kg/day). Another group of rats received normal water and served as the control group. Three, 6, 9, 12 and 18 months postoperatively, in the rats of both groups, the proximal sciatic nerve stump was injected with horseradish peroxidase to label the spinal cord neurons of the sciatic nerve nucleus. While in untreated rats the number of horseradish peroxidase-labelled neurons decreased with the increase in denervation time, in acetyl-L-carnitine-treated rats the number of horseradish peroxidase-labelled neurons remained stable for as long as 12 months of denervation and decreased only after 18 months of denervation. Furthermore, acetyl-L-carnitine-treated rats showed a significantly higher (p less than 0.05) number of horseradish peroxidase-labelled neurons with respect to untreated rats both after 9 and 12 months of denervation. In Experiment 3, the sciatic nerve was cut and then repaired after periods of 3, 6, 9, 12, and 18 months. Four months after nerve repair, the sciatic nerve was again cut and the proximal nerve stump was injected with horseradish peroxidase to label the spinal cord neurons of the sciatic nerve nucleus. Both acetyl-L-carnitine-treated and untreated rats showed a tendency to have an increased number of horseradish peroxidase-labelled neurons with respect to intact rats of correspondent ages.(ABSTRACT TRUNCATED AT 400 WORDS)     

Chlorhexidine susceptibility and Eagle effect in planktonic cells and biofilm of nosocomial isolates

European Journal of Clinical Microbiology & Infectious Diseases - The aim of this study is to evaluate the chlorhexidine gluconate (CHG) susceptibility in both planktonic cells and biofilm of...     

P0.1 is a useful parameter in setting the level of pressure support ventilation

Objective The purpose of this study was to investigate whether changes in breathing pattern, neuromuscular drive (P0.1), and the work involved in breathing might help to set the individual appropriate level of pressure support ventilation (PSV) in patients with acute respiratory failure (ARF) requiring ventilatory assistance.Design: A prospective, interventional study.Setting An 8-bed multidisciplinary intensive care unit (ICU).Patients Ten patients with ARF due to adult respiratory distress syndrome (ARDS), sepsis or airway infection were included in the study. Chronic obstructive pulmonary disease (COPD) patients with acute exacerbation were excluded. None of these patients was in the weaning process.Interventions We found a level of pressure support able to generate a condition of near-relaxation in each patient, as evidenced by work of breathing (WOB) values close to 0 J/l. This level was called PS 100 and baseline physiological measurements, namely, breathing pattern, P 0.1 and WOB were obtained. Pressure support was then reduced to 85%, 70% and 50% of the initial value and the same set of measurements was obtained.Measurements and results Flow ( ) was measured by a flow sensor (Varflex) positioned between the Y-piece of the breathing circuit and the endotracheal tube. Tidal volume was obtained by numerical integration of the flow signal. Airway pressure (P_aw) was sampled through a catheter attached to the flow sensor. Esophageal pressure (P_es) was measured with a nasogastric tube incorporating an esophageal balloon. The esophageal balloon and flow and pressure sensors were connected to a portable monitor (CP 100 Bicore) that provided realtime display of flow, volume, P_aw and P_es tracings and loops of P_es/V, P_aw/V and /V relationships. The breathing pattern was analyzed from the flow signal. Patient work of breathing (WOB) was calculated by integration of the area of the P_es/V loop. Respiratory drive (P 0.1) was measured at the esophageal pressure change during the first 100 ms of a breath, by the quasiocclusion technique. When pressure support was reduced, we found that the respiration rate significantly increased from PS 100 to PS85, but varied negligibly with lower pressure support levels. Tidal volume behaved in a similar way, decreasing significantly from PS 100 to PS85, but hardly changing at PS 70 and PS 50. In contrast, WOB and P 0.1 increased progressively with decreasing pressure support levels. The changes in WOB were significant at each stage in the trial, whereas P 0.1 increased significantly from PS 100 at other stages. Linear regression analysis revealed a highly positive, significant correlation between WOB and P 0.1 at decreasing PSV levels (r=0.87), whereas the correlation between WOB and ventilatory frequency was less significant (r=0.53). No other correlation was found.Conclusions During pressure support ventilation, P 0.1 may be a more sensitive parameter than the assessment of breathing pattern in setting the optimal level of pressure support in individual patients. Although P 0.1 was measured with an esophageal balloon in the present study, non-invasive techniques can also be used.     

Ceftriaxione associated biliary lithiasis in newborns-report of two cases

The occurrence of biliary calculosis as a complication of the use of ceftriaxone was first described in an 18-year-old patient with chronic granulomatosis. Since then many reports have been published on this type of complication both in children and in adults, but until the present moment, this complication had never been reported in pre-term neonates.The authors describe two cases of biliary calculosis associated with the use of ceftriaxone in preterm-newborns, emphasizing that due to the frequent use of this type of antibiotic in neonatal I.C.U., routine ultrasonographic control exams should be performed to diagnose this possible complication in all neonates receiving ceftriaxone.     

The effect of surgical glove powder on proliferation of human skin fibroblast and monocyte/macrophage

The effect of surgical glove powders (Biosorb, Keoflo, and CaCO3) and Hydrocote (powder-free lubricating agent, Biogel) was examined on human skin fibroblasts and monocyte/macrophage cell lines (U937 and HL-60). Glove powders (0.1-100 micrograms/ml) in the presence of 10% fetal bovine serum (FBS) had no significant effect on the rate of 3H-thymidine uptake and proliferation of these cells after 48 h and 7 days of exposure, respectively. However, they inhibited HL-60 growth after 10 days, and Biosorb and CaCO3 inhibited U937 after 10-21 days of exposure compared with control. In the presence of low serum (0.5%), Biosorb, but not Keoflo, CaCO3, and Hydrocote, inhibited HL-60 cells after the third day of exposure (p < 0.05), whereas they were without any effect on U937 cells. Further incubation resulted in a significant decrease in cell density in all treatments, as well as controls, because of cell death. In the presence of 2% serum, glove powder-treated HL-60 significantly increased in cell numbers during the first 3 days, and the cells became stationary thereafter, whereas Keoflo and CaCO3-stimulated U937 reached a maximal by 9 days of treatment. Coculturing of fibroblasts directly with macrophages (0.4-5 x 10(5) cells per dish) or incubation with macrophage culture-conditioned media (CCM) stimulated quiescent fibroblast growth equal to that induced by 10% and 0.5% serum, respectively (p < 0.05). However, incubation of fibroblasts with glove powder-treated HL-60 CCM (except CaCO3) inhibited (p < 0.05) and CCM from Biosorb-treated U937 stimulated (p < 0.05) fibroblast proliferation. The CCM from glove powder-treated HL-60 and U937 did not have any significant effect on the rate of 3H-thymidine incorporation into fibroblasts compared with controls. The present observations suggest that glove powder action on fibroblast and macrophage growth in vitro depends on both the serum concentration of the culture medium and the length of exposure. The results imply that glove powders may have an adverse effect in vivo by directly influencing the biologic activity of macrophages, as well as other cell types, leading to alterations in the early phases of wound healing.