Arterial changes following single-dose irradiation

In this reported experiment, the serial morphologic changes in the rabbit ear central artery, following a single dose of 45 Gy 60Co gamma-ray irradiation, were investigated using light and scanning electron microscopy. Under light microscopy, mild intimal proliferation, disorganization of smooth muscle, and severe perivascular fibrosis were observed. These appeared to be caused by increased intimal cell death and lower repair capability after large single-dose irradiation. Under scanning electron microscopy, the endothelial cells did not show significant morphologic changes during the first 4 weeks. At 6 and 10 weeks after irradiation, the endothelial cells shrank in all directions and detached from the basement membrane. These changes accord with the theory that radiation damage following therapeutic dosage occurs within the DNA of the cell, and that there is no significant change until the cell attempts to divide.     

Histological changes in the canine stomach following massive electron beam irradiation

The histologic changes induced by irradiation of the stomachs of dogs were examined one hour to nine months after irradiation. The irradiated area of the stomach progressed to ulcer formation by way of hyperemia and erosion; on the other hand, there were simultaneous signs of recovery. Regenerating epithelium appeared during the first week and migrated from the surface adjacent to the ulcer to the center of the ulcer. Subsequently the muscularis mucosae extended, and then the submucous coat was repaired. Regeneration of the nerve fibers around the muscularis mucosae seemed to reach its maximum three weeks after irradiation. These proliferating nerves degenerated with deepening of the radiation ulcer, but they were unexpectedly radioresistant and protrude from the surface of the ulcer into the necrotic surrounding tissues. It is concluded that the effect of irradiation on the alleviation of the pain of stomach cancer is not due to the degeneration of the nerves but to elimination of the stimulation of nerves on account of the radiation effect on the cancer cells themselves.     

Dynamic lung function changes following long-term work in polluted environments

15N-labelled glycine, ammonium chloride, and L-aspartic acid were infused intravenously into a series of non-diabetic adults at a constant rate for 4 to 8 hours. Midway during the infusion, a pulse of 8-10 units of regular insulin was injected as a pulse or infused at a constant rate for the remainder of the 15N infusion period. Frequent urine specimens were collected during the infusion period. The 15N enrichment of the urinary urea, ammonia, and amino acids increased smoothly with time until the insulin was given. The pulse of insuline caused a downturn on the N enrichment. We concluded from this that a) the effect of a pulse of insulin on human urea and ammonia metabolism lasted for about one hour; and b) insulin affected glutamine distribution in the plasma.     

Cannabis and motor function: fMRI changes following 28 days of discontinuation.

The authors hypothesized that supplementary motor cortex (SMA) and anterior cingulate cortex (ACC) activation in chronic cannabis users, studied 4 to 36 hours after their last episode of use, would disappear by Day 28 of abstinence during finger-tapping tests. Eleven cannabis users and 16 comparison subjects were scanned during right (RFT) and left (LFT) finger-tapping tasks on a GE 1.5 Tesla scanner retrofitted with a whole body echo planar coil. Image analyses were conducted in SPM99 using an ROI approach to define each Brodmann area (BA). Differences in cerebral activation were examined in the left and right primary motor cortex (BA4), SMA (BA6), and ACC (BA24 and BA32 separately). The authors found diminished activation for contralateral BA6 from Day 0 to Day 28. For LFT, the authors also found: ipsilaterally diminished BA6 activation on Day 7, but not Day 0 or Day 28; ipsilaterally diminished BA32 activation on Day 0, but not Day 7 or Day 28; contralaterally diminished BA 4 activation on Day 28, but not Day 0 or Day 7; and contralaterally diminished BA32 activation on Day 0 and Day 28, but not Day 7. For RFT, the authors found ipsilaterally diminished BA32 activation on Days 0 and 7 but not on Day 28; contralaterally diminished BA32 activation on Days 0, 7, and 28; and ipsilaterally diminished BA6 activation on Days 0, 7, and 28. These results suggest that residual diminished brain activation is still observed after discontinuing cannabis use in motor cortical circuits. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Suppression of mouse-killing in rats following irradiation

Suppression of mouse-killing was produced following pairings of mouse-presentations (CS) with 96 roentgens of ionizing radiation (US) at O ( less than 2 min.) and 30 min. US-CS interstimulus intervals. No suppression was found at CS-US intervals of 30 min., 1hr., and 2 hr., or at US-CS intervals of 1 hr. and 2 hr.     

Sociodemographic and psychological predictors of changes in dietary fat consumption in adults with high blood cholesterol following counseling in primary care.

The associations between sociodemographic variables, psychological factors, and changes in dietary fat consumption over 4 months were assessed in a randomized controlled trial of behavioral counseling versus standard advice. Patients were 141 men and 150 women, with an average age of 52.1 years and total cholesterol level of 7.27 mmol/l (278 mg/dl). Smokers, younger patients, and those with greater body mass index had higher fat intake at baseline. Behavioral counseling led to greater reductions in fat intake than did standard advice. Self-efficacy and ratings of benefits of low-fat diets were related to fat consumption at baseline, and changes in these measures were correlated with changes in fat intake. Family support, baseline anticipated regret, and (for the behavioral counseling group only) baseline behavioral intentions predicted reductions in fat intake. The results indicated that psychosocial variables associated cross-sectionally with fat consumption do not necessarily predict change and that factors involved in the process of change and the prediction of change need to be differentiated. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Short-term outcome and predictors of adverse events following pulmonary thromboendarterectomy

Pulmonary complications including hypoxemia, right heart failure, and prolonged ventilation may follow pulmonary thromboendarterectomy (PTE) performed via cardiopulmonary bypass (CPB) with deep hypothermic circulatory arrest. Seventeen adult patients have undergone PTE at the University of Maryland Medical System during the preceding 3 years. From these patients, clinical and hemodynamic parameters were tabulated pre-CPB, post-CPB, at admission to the intensive care unit (ICU), and prior to discontinuation of invasive monitoring in the ICU. Data on anthropometric variables, survival, and times of extracorporeal circulation, mechanical ventilation, and hospital stay were also collected. The mean values for pulmonary arterial systolic and diastolic pressures and pulmonary vascular resistance (PVR) decreased significantly from pre-CPB values after PTE (all p < 0.05). Mild mixed acidosis present at ICU admission resolved prior to discharge (p = 0.002). The length of mechanical ventilation time was positively correlated with the absolute post-CPB PVR and negatively correlated with the relative change in central venous pressure (CVP) from pre-CPB to post-CPB values (r = 0.75, p = 0.037). Of the pre-CPB anthropometric variables, only body mass index was significantly higher in nonsurvivors (p = 0.037). Pulmonary artery pressures and vascular resistance fall significantly after PTE. A lower post-CPB PVR and a relatively decreased (i.e., from pre-CPB values) CVP predict reduced length of postoperative ventilation but not of the hospital stay. Mortality appears increased in patients with a large body habitus.     

Prospective predictors of positive emotions following spousal loss.

Whereas theoreticians are interested in modeling how bereavement contributes to health, the bulk of research on spousal bereavement is conducted after a loss has occurred. Using prospective longitudinal data, this study examined the extent to which positive emotion following spousal loss varies on the basis of preloss characteristics of the bereaved spouse and the marital relationship prior to loss. Analyses are based on the National Survey of Midlife Development (MIDUS), a 2-wave panel survey of adults in the contiguous United States. Results indicate that compared with continuously married controls, widowed participants experienced a significant decline in positive emotion within 3 years following loss. Conversely, no significant declines in positive emotion were evident among widowed persons with greater preloss trait resilience or greater marital strain. Results provide support for the notion that adjustment to loss may be linked to factors that precede actual loss. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive predictors of symptom return following depression treatment.

This study tested whether poor cognitive change during depression treatment predicted time to return of depressive symptoms. Depressed participants (N=121) completed assessments of dysfunctional attitudes and extreme thinking (i.e., number of totally agree and totally disagree responses) during hospitalization and again after 6 months of outpatient treatment. Participants then completed monthly depression assessments for 1 year. Survival analyses for time to symptom recurrence during follow-up were conducted among participants who reported 50% improvement in their depressive symptoms and were at least partially asymptomatic at the end of treatment (n=53). Poor change in dysfunctional attitudes and poor change in extreme thinking both predicted shorter time to return of depressive symptoms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neurotensin--structure, origin and biological function

We have developed a least-squares refinement procedure that in an automated way performs three-dimensional alignment and averaging of objects from multiple reconstructions. The computer implementation aligns the three-dimensional structures by a two-step procedure that maximizes the density overlap for all objects. First, an initial average density is built by successive incorporation of individual objects, after a global search for their optimal three-dimensional orientations. Second, the initial average is subsequently refined by excluding individual objects one at a time, realigning them with the reduced average containing all other objects and including them into the average again. The refinement is repeated until no further change of the average occurs. The resulting average model is therefore minimally biased by the order in which the individual reconstructions are incorporated into the average. The performance of the procedure was tested using a synthetic data set of randomly oriented objects with Poisson-distributed noise added. The program managed well to align and average the objects at the signal/noise ratio 1.0. The increase in signal/noise ratio was in all investigated cases almost equal to the expected square root of the number of objects. The program was also successfully tested on a set of authentic three-dimensional reconstructions from an in situ specimen containing Escherichia coli 70S ribosomes, where the immediate environment of the reconstructed objects may also contain variable amounts of other structures.     

Glutamine dipeptide attenuate mucosal atrophic changes and preservation of gut barrier function following 5-FU intervention

Traditional parenteral nutrition (PN) and chemotherapy may lead to changes mucosal morphology and gut barrier function. To investigate the effects of alanyl-glutamine on intestinal mucosal morphology and gut barrier function in PN-fed rats challenged with 5-FU male Wistar rats were central catheterized and randomily divided into two groups: PN group (n = 10) that received traditional parenteral nutrition solution only, and Ala-Gln group (n = 10) that received glutamine dipeptide enriched nutritional solution (3% Ala-Gln). The rats were maintained on their respective diets for 7 days. 5-FU (75 mg/kg) was injected intraperitoneally at 8 am on day 4. All rats were gavaged with lactulose (100 mg) and mannitol (50 mg) in 2ml before and three days after administration of 5-FU. Ala-Gln group maintained serum glutamine concentration, intestinal mucosal morphology. While bacterial translocation rates in ala-Gln group was 30%, in PN group was 90% (P < 0.05). Similar intestinal permeability was observed on day 3 in both groups. The control group had a significantly increased intestinal permeability on day 7 (P < 0.05), while Ala-Gln group maintained the intestinal permeability. It was suggested that alanyl-glutamine maintained intestinal morphology and gut barrier function in PN-fed rats challenged with 5-FU.     

Alterations in the expression of chemokine mRNA levels in fibrosis-resistant and -sensitive mice after thoracic irradiation

Two adjective pairs in comparative form, more-less and taller-shorter, were tested with moderately mentally retarded (MR) and nonretarded children (NR) matched on verbal mental age (MA) and socioeconomic status (SES) in a "show" and an "act-out" experimental condition. The data indicated that all the main effects, the group, the experimental condition, and the unmarked-marked relational terms were significant and so were the interactions of the Group x Experimental Conditions, Group x Unmarked Versus Marked Relational Terms, and Group x Experimental Conditions and Unmarked Versus Marked Relational Terms. A logistic regression analysis (LRA) showed that the relational term shorter in the act-out condition best predicted classification membership for the subjects in either group, suggesting that the MR children were less able to self-regulate behavior. The error types, however, mainly observed in the act-out experimental condition were the same from a semantic point of view in either group. The effect of the unmarked versus marked distinction cannot be considered independent of the experimental conditions applied.     

Kidney function and age are both predictors of pharmacokinetics of metformin

The effects of renal impairment and age on the pharmacokinetics of metformin were evaluated. The subjects, including 6 young, 12 elderly, and 3 middle-age healthy adults and 15 adults with various degrees of chronic renal impairment (CRI) each were given a single, 850-mg metformin HCl tablet. Multiple whole blood, plasma, and urine samples were collected and analyzed for metformin levels using a high-performance liquid chromatography (HPLC) method. In healthy elderly individuals, the plasma and whole blood clearance/absolute bioavailability values [CL/F and (CL/F)b], and corresponding renal clearance values (CLR and CLR,b) of metformin were 35-40% lower than the respective values in healthy young individuals. These two groups did not differ significantly with respect to volume of distribution (Vd), time to peak concentration (tmax), and parameters related to metformin's appearance in the urine. In the moderate and severe CRI groups, all clearance values were 74-78% lower than in the healthy young/middle-age group, and all other evaluable pharmacokinetic parameters (with the exception of tmax) differed significantly in this group. In the mild CRI group, clearance values of metformin, which were 23-33% lower than in the young/middle-age group, were the only parameters that differed significantly. Based on a regression analysis of the combined data, both creatinine clearance (CL*cr; corrected for body surface area) and age are predictors of metformin clearance, with the following model best fitting the data: CL/F [or (CL/F)b, CLR, CLR,b] = alpha + beta.CL*cr + gamma.CL*cr.age. Metformin should not be used in patients with moderate and severe CRI, or in patients with mild, but not absolutely stable, renal impairment. The initial and maximum doses in elderly patients and patients with stable mild CRI should be lowered to approximately one third that given to the general (i.e., patients without non-insulin-dependent diabetes) population.     

Reproduction function in mice exposed to neonatal irradiation

In colony-bred Wistar rats maintained for several weeks on a high-percent fatty food (fat content 50%) compared with controls (3% fat in food) the concentrations of the following lipids were determined quantitatively: In serum lipid phosphorus (Lip. P.), free fatty acids (FFA), triglycerides (TG), free cholesterole (FC) and cholesteryl ester (CE), in liver Lip. P,TG, FC and CE, in epididymal adipose tissue Lip. P. FFS and TG. With increasing weight differences between the two animals groups, in the phase of steady weight growth (,,dynamic phase", age of investigation 9 weeks, after 4 weeks on fatty food) a significant rise in serum FFS over the controls is observed with increases in TG and CE concentrations in the liver. After about 20 weeks of life the weight growth slows down; in this subsequent "static phase" the TG and CE accumulation in the liver further increases. Investigation of the epididymal adipose tissue suggests hypertrophy of the adipose cells. The results obtained with both phases are discussed with regard to possible metabolic alterations.     

ICAM-1 induction in the mouse CNS following irradiation

Injury to the central nervous system (CNS) results in inflammation, increased trafficking of leukocytes into the CNS, induction of cytokines, and exacerbation of the primary injury. The increased trafficking of neutrophils into the CNS has been described following a number of injury models including stab, stroke, and excitotoxin-induced injury. This enhanced trafficking has largely been ascribed to the adhesion molecule intercellular adhesion molecule-1 (ICAM-1, CD54). In the current study, we wished to determine if the inflammation caused by irradiation of the CNS resulted in a similar induction of ICAM-1. C3H/HeJ mice were irradiated using gamma irradiation aimed over the right cerebral hemisphere. The relative induction of ICAM-1 mRNA levels was determined using quantitative RT-PCR 6 hours following irradiation with either 0, 5, 15, 25 or 35 Gy. ICAM-1 message was seen to exhibit a normal dose response curve with increasing mRNA levels seen at 15 Gy and higher. To determine the cellular distribution of the ICAM-1 protein following irradiation, mice were sacrificed at 4 hrs, 24 hrs, 48 hrs and 7 days following 25 Gy irradiation and the tissue was processed for ICAM-1 immunocytochemistry. ICAM-1 staining was seen to increase in both endothelial cells and astrocytes beginning as early as 4 hrs. The staining intensity continued to increase throughout the 7 day period observed. Together, these results suggest that irradiation of the CNS causes a rapid induction of both ICAM-1 mRNA and protein. This suggests that increased leukocyte trafficking into the CNS may exacerbate the inflammation induced by radiation injury.