Enriched environment delays the onset of hippocampal damage after global cerebral ischemia in rats

An enriched environment has been shown to improve cognitive, behavioral and histopathological outcome after focal cerebral ischemia and head trauma. The purpose of this study was to determine the effect of an enriched environment on histopathology following global cerebral ischemia. Wistar rats (21 weeks of age) were placed in different environments [standard cages (SC) or enriched environment (EE) cages] for 2 months before and either 6 days or 2 months after ischemia. Rats underwent 10 min of global ischemia by bilateral carotid artery occlusions plus hypotension. Five groups (n=4-5 in each group) were studied: (1) rats kept in SC before and 2 months after ischemia; (2) rats kept in SC before ischemia but transferred to an EE for 2 months after ischemia; (3) rats kept in EE before and after ischemia for 2 months; (4) rats kept in SC before and 6 days after ischemia; (5) rats kept in EE before and 6 days after ischemia. At 7 days or 2 months after ischemia, brains were perfusion-fixed, and ischemic injury was assessed by counting numbers of normal neurons in the hippocampal CA1 sector. Physiological variables showed no inter-group differences. Rats housed in EE for 2 months before and for 6 days (but not 2 months) after global ischemia showed significantly better preservation of pyramidal neurons in the hippocampal CA1 area when compared to control animals (middle CA1, 20.5+/-5.4 vs. 2.8+/-0.6; lateral CA1, 31.5+/-7.2 vs. 2.6+/-0.6, respectively). The present data suggest that housing in EE for 2 months before and 6 days after ischemia can delay the onset of damage to hippocampal pyramidal neurons, which eventually occurs despite 2-month EE.     

Concomitant use of cigarettes and smokeless tobacco: prevalence,correlates, and predictors of tobacco cessation

BACKGROUND: This study examined the characteristics, tobacco use patterns over time, and predictors of tobacco cessation among concomitant users of cigarettes and smokeless tobacco. METHODS: Participants were employed adults residing in the southeastern United States who participated in the Working Well cancer prevention trial. Participants were assessed at baseline and followed-up 4 years later. RESULTS AND CONCLUSIONS: The study yielded several key findings: (a) the prevalence of concomitant smoking and smokeless tobacco use was high among males and nonexistent among females, (b) the characteristics of concomitant users were relatively distinct from those of both smokers and smokeless tobacco users, (c) concomitant users exhibited substantial variability in their tobacco use patterns and were less likely to stop using tobacco than were smokers or smokeless tobacco users, (d) indicators of nicotine dependence predicted tobacco cessation for both smokers and smokeless tobacco users, but were largely unrelated to tobacco cessation among concomitant users, and (e) demographics, environmental variables, and measures derived from the transtheoretical model were not consistent predictors of tobacco cessation after controlling for nicotine dependence.     

Differential contributions of ERK and PI3-kinase to the regulation of cyclin D1 expression and to the control of the G1/S transition in mouse embryonic stem cells

Mouse embryonic stem (ES) cells are known to express D-type cyclins at very low levels and these levels increase dramatically during in vitro and in vivo differentiation. Here, we investigate some of the signalling pathways regulating expression of cyclin D1 and progression to S phase, the Ras/Extracellular signal-regulated protein kinase (ERK) pathway and the phosphatidylinositol 3-kinase (PI3-kinase) pathway. We demonstrate that ERK phosphorylation is fully dispensable for the regulation of cyclin D1 level and for the progression from G1 to S phase in ES cells. By contrast, PI3-kinase activity is required for both. Differentiation induced by retinoic acid results in the gain of ERK-dependent control of cyclin D1 expression and of S phase progression. Differentiation is also paralleled by an increase in PI3-kinase activity. This leads (a) to an increase in the p70 S6 kinase-dependent regulation of the steady-state level of cyclin D1, and (b) to a concomitant decrease in the GSK3beta-dependent rate of cyclin D1 degradation. Altogether, these multiple pathways account for the dramatic increase in the level of cyclin D1 protein which parallels ES cell differentiation. Our studies suggest that PI3-kinase is an important regulator of the ES cell cycle and that its activity is not regulated by mitogen stimulation.     

Chronic phase CML patients possess T cells capable of recognising autologous tumour cells

Much circumstantial evidence points to the immunogenicity of chronic myloid leukemia (CML) cells, most impressively the well-established T cell-dependent GvL effect seen in bone marrow transplantation. However, only a small number of shared antigens expressed by CML cells have been identified as potential targets for T cell-mediated immune responses which might be exploited for immunotherapy. It may be that unique antigens expressed by individual tumours are more potent rejection antigens if the patient's own T cells could be encouraged to react against them. Work is reviewed here which documents that in vitro mixed cultures between autologous T cells and dendritic cells of chronic-phase CML patients can give rise to sensitised T cells capable of recognising the patient's tumour cells. Additionally, mixed autologous tumour cell/lymphocyte cultures, modified by the addition of cytokine cocktails, may also result in the generation of similarly sensitised T cells. These results could be exploited for adoptive immunotherapy, and possibly, after identification of the antigens recognised, also for active immunotherapy, i.e. including therapeutic vaccination.     

Automated registration of laser Doppler perfusion images by an adaptive correlation approach: application to focal cerebral ischemia in the rat

Hemodynamic changes are extremely important in analyzing responses from a brain subjected to a stimulus or treatment. The Laser Doppler technique has emerged as an important tool in neuroscience research. This non-invasive method scans a low-power laser beam in a raster pattern over a tissue surface to generate the time course of images in unit of relative flux changes. Laser Doppler imager (LDI) records cerebral perfusion not only in the temporal but also in the spatial domain. The traditional analysis of LD images has been focused on the region-of-interest (ROI) approach, in which the analytical accuracy in an experiment that necessitates a relative repositioning between the LDI and the scanned tissue area will be weakened due to the operator's subjective decision in data collecting. This report describes a robust image registration method designed to obviate this problem, which is based on the adaptive correlation approach. The assumption in mapping corresponding pixels in two images is to correlate the regions in which these pixels are centered. Based on this assumption, correlation coefficients are calculated between two regions by a method in which one region is moved around over the other in all possible combinations. To avoid ambiguity in distinguishing maximum correlation coefficients, an adaptive algorithm is adopted. Correspondences are then used to estimate the transformation by linear regression. We used a pair of phantom LD images to test this algorithm. A reliability test was also performed on each of the 15 sequential LD images derived from an actual experiment by imposing rotation and translation. The result shows that the calculated transformation parameters (rotation: theta =7.7+/-0.5 degrees; translation: Delta x =2.8+/-0.3, Delta?=4.7+/-0.4) are very close to the prior-set parameters (rotation: theta=8 degrees; translation: Delta x=3, Delta y=5). This result indicates that this approach is a valuable adjunct to LD perfusion monitoring. An original sequence of LD images that recorded cerebral perfusion through a cranial window before, during and after middle cerebral artery occlusion (MCAo) is presented, together with the registered image sequence. Cerebral perfusion data acquired in a pixel-based manner from different anatomic locations of the registered LD image sequence are also presented over the whole time-course of the experiment.     

Targeting peptides for microglia identified via phage display

Screening with a 7-mer phage display peptide library, a panel of cell-targeting peptides for the murine microglial cell line, EOC 20, was recognized. A number of similar, but not identical, sets of sequences representing more than 75% of all the cell line-binding clones were identified. Comparative analysis indicated that motif S/(T) F T/(X) Y W is present in the vast majority of the binding sequences. The selectivity and specificity of the dominant peptide sequence identified for microglia was confirmed using both phage displaying the peptide and the synthetic peptide alone.     

The effect of continuous intraabdominal nebulization of lidocaine during gynecological laparoscopic procedures- a pilot study

Although laparoscopic surgery is known to cause less postoperative pain when compared to laparotomy, some patients still suffer from excessive pain, especially during the first stages of recovery. The purpose of our study was to assess the effect of intraperitoneal nebulization of lidocaine during gynecological laparoscopic procedures on perioperative pain. The study was a prospective, randomized, double-blinded, placebo-controlled trial (Canadian task force classification I) that included 23 patients who underwent outpatient gynecological laparoscopic procedures. Patients were randomly assigned either to a study group that received 5 mg/kg of lidocaine intraperitonealy during surgery (n=15) or to a control group that received sterile water in the same manner (n=8). The fluid was infuslated along with the CO₂ through a Insuflow® device. All patients received the same anesthetic technique. Intraoperative pain as assessed by changes in the vital signs was treated with fentanyl. Postoperative pain was evaluated according to postoperative opioid requirements and by the Visual Analogue Scale (VAS) at 15 min, 1 h and 24 h postoperatively. The VAS score was found to be lower for the study group 1 h after surgery (p=0.023). There was no difference in the VAS scores at 15 min (p=0.9) and 24 h (p=0.11) after surgery. A correlation analysis showed no association between the amount of lidocaine insufflated and the severity of the postoperative pain. There was no difference in terms of fentanyl administration during surgery or opiod consumption following surgery between the groups. We concluded that continuous intraperitoneal insuflation of lidocaine using an Insuflow® device may significantly reduce pain in the initial stage of postoperative recovery.     

Chemobiokinetics of sarcolysin and its peptides with glutaminic acid

A 14C study of chemobiokinetics of sarcolysin and its peptides of glutaminic acid, dosage and routes of administration was conducted in intact rats and those bearing Walker's carcinoma. Similar in shape for peptides, kinetic curves differed from those found for sarcolysin. The rates of absorption and excretion of sarcolysin peptides in intraperitoneal and, particularly, oral administration were lower than those of sarcolysin. Tumor appeared to play a role in a higher rate of peptide excretion. While sarcolysin and its peptides distribution in organs and tissues was generally identical, time of peak radioactive concentration build-up was different. Time needed for accumulation and excretion of peptides from tumor was much longer than from other organs or tissues. Sarcolysin went chiefly to urine while peptides--to faeces.     

Production of gamma and alpha interferons by human blood leukocytes in sequential induction

A schedule for human gamma and alpha interferon production by successive administration, at 2-3-day intervals, of the proper inducers (phytohemagglutinin and Newcastle disease virus (NDV), or staphylococcal enterotoxin A and NDV) into the same suspensions of peripheral blood leukocytes has been proposed. The schedule may be used in laboratory practice and manufacture.