Ischaemic vascular disease and long-term mortality in emergency abdominal surgical patients: A population-based cohort study.

BACKGROUND: Emergency abdominal surgery carries a high mortality, as patients are often frail with significant comorbidity. We aimed to evaluate the association between co-existing ischaemic vascular disease (IVD) and long-term mortality in patients undergoing emergency abdominal surgery. METHODS: We included adult emergency abdominal surgical patients operated on 13 Danish hospitals between 1 January 2009 and 31 December 2010. Appendectomies were excluded. Data were retrieved from the National Patient Registry (NPR) and the Danish Anaesthesia Database. Preoperative IVD status was retrieved from NPR. We used crude and adjusted Cox regression analysis. The primary outcome was mortality within eight years. The secondary outcome was mortality within 30 days. RESULTS: We included 4864 patients, of which 2584 (53.7%) died within 8 years. Some 20.9% (1019/4864) had preoperative IVD. The adjusted association between preoperative IVD and mortality within 8 years was hazard ratio (HR) 1.10 (95% confidence interval [CI], 1.00-1.20; P = .045). At 30 days, this association was HR 0.97 (95% CI, 0.84-1.13). CONCLUSION: In adult major emergency abdominal surgical patients, preoperative IVD was prevalent and associated with a 10% relative increase in long-term mortality, but not in short-term mortality.

Development of small intestinal enzyme activities and their relationship with some gut regulatory peptides in grazing sheep.

Growth depends on an animal's capacity to digest and assimilate ingested nutrients, and insufficient supply and impairment will constrain lamb growth. Eight groups of Alpine Finewool lambs were harvested on 0, 3, 7, 14, 21, 28, 42, and 56 d to measure pH and enzymatic activities in the duodenum, proximal jejunum, middle jejunum, distal jejunum, and ileum mucosa or digesta. From the duodenum to the ileum the pH of intestinal mucosa and digesta increased, whereas pH changed very little with age. The trypsin, chymotrypsin, lipase, lactase, and α-amylase activities observed at birth decreased by d 3, followed by a nonuniform enzymatic response in the small intestine. The trypsin activity increased from d 3 to peak, at d 21, followed by a decline. Chymotrypsin activity followed the same general trend but with smaller responses in activities. Trypsin demonstrated greater enzymatic activity than chymotrypsin at the same age. The lipase activity of small intestinal mucosa and digesta changed little with age. The lactase activity was high at birth, decreased by d 3, and then increased, followed by a decrease as lambs approached weaning. α-Amylase activity was similar in the small intestinal mucosa and digesta at birth but increased with age for the duodenum and proximal jejunum. Plasma concentrations of cholecystokinin (CCK), secretin, and gastrin were positively correlated ( < 0.05) with ileal mucosa lipase activity. Plasma concentration of CCK, secretin, gastrin, and gastric inhibitory polypeptide (GIP) were positively correlated ( < 0.05) with ileal mucosa lactase activity. Plasma concentration of pancreatic polypeptide (PP) was negatively correlated ( < 0.05) with lactase activity in the middle jejunum and ileal mucosa. Plasma concentrations of CCK, secretin, gastrin, and GIP were positively correlated ( < 0.05) with α-amylase activity in the ileal mucosa but negatively correlated ( < 0.05) with duodenum, prejejunum, and middle jejunum. Plasma PP concentrations were positively correlated ( < 0.01) with α-amylase activity of duodenum, middle jejunum, and postjejunum mucosa but not with the enzyme activity of postjejunum and ileal mucosa ( > 0.05). Small intestinal enzymatic activities exist and may be sufficient to enhance lamb growth via appropriate nutrient supplementation.

Microbiology of surgical site infections after gastrointestinal surgery in the south region of The Netherlands.

AIM: To give an overview of the microbiology of blood and wound samples from surgical site infections (SSIs) after gastrointestinal surgery, as well as the antimicrobial susceptibility of the microorganisms involved, and to discuss the appropriateness of the prophylactic antibiotics administered. MATERIALS & METHODS: During a 3.5-year study period, wound swabs and blood samples of patients with an SSI were taken in the first 48 h after surgery until 30 days thereafter. RESULTS: Most pathogens were isolated from wound swabs. Escherichia coli (25%) and Pseudomonas aeruginosa (10%) were the most frequently found microorganisms. Both microorganisms showed a slight tendency towards a decrease in susceptibility for the tested antibiotics, although after correction, this was not significant. CONCLUSION: The comparison between wound swabs taken in the first 48 h after a surgical procedure and swabs in the 30 days thereafter provides important information concerning the microbiology of SSIs and the development of antibiotic resistance of the causative agents over time.

Seasonal variability in otariid energetics: implications for the effects of predators on localized prey resources.

Otariids, like other wild mammals, contend with a wide variety of energetic demands across seasons. However, due to the cryptic behaviors of this marine group, few studies have been able to examine longitudinal energetic costs or the potential impact of these costs on seasonal or annual prey requirements. Here we evaluated the changes in energy demand and intake of female California sea lions (Zalophus californianus) during reproductive (n=2 sea lions) and nonreproductive (n=3) periods. Monthly measurements included resting metabolic rate, blood hormone levels, body condition (blubber thickness and body mass), and caloric intake for adult sea lions throughout molting, late pregnancy, lactation, and postweaning. We found that maintenance energy demands decreased from 32.0 to 23.1 MJ d(-1) before pupping, remaining stable at 19.4+/-0.6 MJ d(-1) during lactation and postweaning. Energy intake rates to meet these demands showed marked changes with activity level and the reproductive cycle, reaching a peak intake of 3.6 times baseline levels during lactation. Translating this into prey demands, we find that 20,000 reproductively active females on San Nicolas Island rookeries would maximally require 4,950 metric tons of Pacific whiting during a month of the breeding season. This localized impact is reduced significantly with postbreeding dispersal and demonstrates the importance of considering spatial and temporal factors driving the energetic requirements of predators when designing marine protected areas.

ATM protein expression correlates with radioresistance in primary glioblastoma cells in culture.

PURPOSE: Glioblastoma multiforme (GBM) is one of the malignancies most resistant to radiation therapy. In contrast, cells derived from individuals with ataxia telangiectasia (AT), possessing mutations in the ATM gene, demonstrate increased sensitivity to ionizing radiation. Using a collection of glioma specimens adapted to tissue culture and several established GBM cell lines, we investigated the relationship between ATM protein expression and radiosensitivity. The three aims of our study were to: (1) quantify ATM protein levels in cultured glioma cells; (2) measure the correlation between ATM protein levels and radiation sensitivity; and (3) examine the dependence of ATM on p53 status. METHODS AND MATERIALS: Glioma specimens were collected, catalogued, and adapted to grow in culture. Levels of ATM, p53, and p21 proteins were determined by Western blot. Radiation sensitivities were determined by clonogenic assays. p53 mutation status was determined by DNA sequencing. Correlations were identified by linear regression analysis. RESULTS: ATM protein levels were variable in the primary gliomas. Glioma cell lines demonstrated significantly lower levels of ATM protein. Clonogenic assays of cell strains and cell lines yielded survival fractions (SF2s) consistent with the radioresistant behavior of GBM tumors in vivo. Regression analysis revealed a high correlation between ATM protein levels and SF2 for primary glioma cell strains, but not for established GBM cell lines. p53 status failed to predict radiosensitivity. CONCLUSION: We have demonstrated that while our collection of low passage cell cultures depends on ATM for their resistance to IR, established cell lines may acquire adaptive characteristics which downplay the role of the ATM gene product in vitro. Therefore, attenuating ATM gene expression may be a successful strategy in the treatment of GBM tumors.

Acetaminophen selectively reduces glioma cell growth and increases radiosensitivity in culture.

Glioblastoma multiforme (GBM) is a highly lethal brain cancer. Using cultures of rodent and human malignant glioma cell lines, we demonstrated that millimolar concentrations of acetylsalicylate, acetaminophen, and ibuprofen all significantly reduce cell numbers after several days of culture. However, their mechanisms of action may vary, as demonstrated by (1) differences in the morphological changes produced by these compounds; (2) varied responses to these drugs with respect to toxicity kinetics; and (3) respective rates of cell proliferation, DNA synthesis, and mitotic index. We studied the effects of acetaminophen on relative cell number further. Evidence is presented that acetaminophen induced cell death by an apoptotic mechanism after a brief burst of mitosis in which cell numbers increased transiently, followed by a reduction in cell number and an increase in DNA fragmentation, as evidenced by terminal deoxytransferase-mediated dUTP-biotin nick end labeling (TUNEL) analysis. Using cultures of adult human brain and embryonic rat brain, we demonstrated that glioma cells were several-fold more sensitive to acetaminophen than normal brain cells in culture. Finally, subtoxic doses of acetaminophen increased the sensitivity of the human glioma cells in culture to ionizing radiation. Taken together, these results suggest that acetaminophen may prove to be a useful therapeutic agent in the treatment of human brain tumors.

Antisense ATM gene therapy: a strategy to increase the radiosensitivity of human tumors.

Atm, the gene mutated in ataxia-telangiectasia (AT) patients, is an essential component of the signal transduction pathway that responds to DNA damage due to ionizing radiation (IR). We attenuated ATM protein expression in human glioblastoma cells by expressing antisense RNA to a functional domain of the atm gene. While ATM expression decreased, constitutive expression of p53 and p21 increased. Irradiated ATM-attenuated cells failed to induce p53, demonstrated radioresistant DNA synthesis, and increased radiosensitivity. Antisense-ATM gene therapy in conjunction with radiation therapy may provide a novel strategy for the treatment of cancer.

Expression of vascular endothelial growth factor in pediatric and adult cerebral arteriovenous malformations: an immunocytochemical study.

Children and adults may differ with respect to their cerebral vasculature in both normal and pathological states. The authors have identified four pediatric patients in whom a cerebral arteriovenous malformation (AVM) recurred after surgery for removal of the AVM and in whom a normal postoperative angiogram had been obtained. This phenomenon has not been observed in adults. The propensity to regrow a cerebral AVM may reflect a less mature cerebral vasculature and a disregulated angiogenic process. Recently, attention has focused on vascular endothelial growth factor (VEGF) as a possible general mediator of angiogenesis in development and neoplasia. A retrospective immunocytochemical analysis of VEGF expression in AVM tissue was conducted to test the hypothesis that VEGF expression may be found in association with the regrowth of AVMs. The results demonstrate a high degree of astrocytic VEGF expression in four (100%) of four specimens from the initial operation in the children with recurrent AVMs as compared to one (14%) of seven nonrecurrent AVMs in the pediatric and two (25%) of eight adult specimens. All of the specimens from the first operation of the recurrent group demonstrate a clear association of cellular immunoreactivity to the abnormal blood vessels, a relationship that was not observed in the specimens from the nonrecurrent groups. These observations indicate that a humoral mechanism mediated by VEGF may play a role in AVM recurrence.

Brain-specific tropomyosins TMBr-1 and TMBr-3 have distinct patterns of expression during development and in adult brain.

In this study we report on the developmental and regional expression of two brain-specific isoforms of tropomyosin, TMBr-1 and TMBr-3, that are generated from the rat alpha-tropomyosin gene via the use of alternative promoters and alternative RNA splicing. Western blot analysis using an exon-specific peptide polyclonal antibody revealed that the two isoforms are differentially expressed in development with TMBr-3 appearing in the embryonic brain at 16 days of gestation, followed by the expression of TMBr-1 at 20 days after birth. TMBr-3 was detected in all brain regions examined, whereas TMBr-1 was detected predominantly in brain areas that derived from the prosencephalon. Immunocytochemical studies on mixed primary cultures made from rat embryonic midbrain indicate that expression of the brain-specific epitope is restricted to neurons. The developmental pattern and neuronal localization of these forms of tropomyosin suggest that these isoforms have a specialized role in the development and plasticity of the nervous system.

Clathrin light chain B: gene structure and neuron-specific splicing.

The clathrin light chains are components of clathrin coated vesicles, structural constituents involved in endocytosis and membrane recycling. The clathrin light chain B (LCB) gene encodes two isoforms, termed LCB2 and LCB3, via an alternative RNA splicing mechanism. We have determined the structure of the rat clathrin light chain B gene. The gene consists of six exons that extend over 11.9 kb. The first four exons and the last exon are common to the LCB2 and LCB3 isoforms. The fifth exon, termed EN, is included in the mRNA in brain, giving rise to the brain specific form LCB2 but is excluded in other tissues, generating the LCB3 isoform. Primary rat neuronal cell cultures express predominantly the brain specific LCB2 isoform, whereas primary rat cultures of glia express only the LCB3 isoform, suggesting that expression of the brain-specific LCB2 form is limited to neurons. Further evidence for neuronal localization of the LCB2 form is provided using a teratocarcinoma cell line, P19, which can be induced by retinoic acid to express a neuronal phenotype, concomitant with the induction of the LCB2 form. In order to determine the sequences involved in alternative splice site selection, we constructed a minigene containing the alternative spliced exon EN and its flanking intron and exon sequences. This minigene reflects the splicing pattern of the endogenous gene upon transfection in HeLa cell and primary neuronal cell cultures, indicating that this region of the LCB gene contains all the necessary information for neuron-specific splicing.

EGF enhances the survival of dopamine neurons in rat embryonic mesencephalon primary cell culture.

Epidermal growth factor (EGF) immunoreactive material has been demonstrated to be present in the basal ganglia. In this study, we investigated the effect of EGF on cells cultured from 16-day embryonic rat mesencephalon, which included dopamine neurons that project to the striatum in vivo. EGF receptors were detected in untreated cultures by [125I]-EGF binding. Treatment of the cultures with EGF resulted in up to 50-fold increases in neuronal high-affinity dopamine uptake. Scatchard analysis of uptake kinetics and counting of tyrosine hydroxylase-immunoreactive cells suggest that the effect of EGF on uptake is due to increased survival and maturation of dopaminergic neurons. By contrast, the high-affinity uptake for serotonin was increased only threefold over its controls. There was no significant effect on high-affinity gamma-aminobutyric acid (GABA) uptake. These results suggest that EGF is acting as a neurotrophic agent preferential for dopaminergic neurons in E16 mesencephalic cultures. Immunocytochemistry for glial fibrillary acidic protein demonstrated an increase in astroglia with EGF treatment. Fluorodeoxyuridine, an agent that is toxic to proliferating cells was able to eliminate the effect of EGF on dopamine uptake, suggesting that EGF may be increasing dopaminergic cell survival largely through a population of dividing cells.

Stimulation of choline acetyltransferase activity by retinoic acid and sodium butyrate in a cultured human neuroblastoma.

Choline acetyltransferase (Acetyl-CoA:choline O-acetyltransferase, EC 2.3.1.6, abbreviated ChAT), the biosynthetic enzyme for acetylcholine and acetylcholinesterase (EC 3.1.1.7, abbreviated AChE) are expressed in a human cholinergic neuroblastoma cell line, MC-IXC. We have shown that ChAT activity can be regulated in culture by retinoic acid, an active metabolite of vitamin A, and by sodium butyrate, an organic fatty acid. Optimal concentrations of these agents produce 4.3-fold and 1.6-fold increases in ChAT activity, respectively. The effects of retinoic acid are statistically significant after 24 h, whereas for sodium butyrate significant differences are seen only after 48 h. Since retinoic acid stimulation of ChAT activity was reversed only by trypsin treatment and not by removal of retinoic acid from the medium, this suggests that this agent may be acting at the level of the cell surface. Other differentiating conditions, such as culture in serum-free medium or addition of 1-2% dimethylsulfoxide did not increase ChAT activity. Acetylcholinesterase activity was shown to increase only in the presence of sodium butyrate, suggesting that retinoic acid and sodium butyrate may be acting via different pathways. Retinoic acid and sodium butyrate both seem to be permissive rather than instructive in regulating ChAT activity in that they are unable to induce ChAT expression de novo in cell lines which do not already express ChAT activity.

Mechanism of activation of choline acetyltransferase in a human neuroblastoma cell line.

In our previous report we have shown that the enzyme choline acetyltransferase (ChAT), responsible for the synthesis of the neurotransmitter acetylcholine, can be regulated in response to treatment by either retinoic acid or sodium butyrate. These responses were dose and time dependent, but the mechanism by which these agents were acting was not understood. We now report the results of studies aimed at elucidating the level at which both sodium butyrate and retinoic acid are able to increase ChAT activity. The effects of these agents on macromolecular synthesis appeared to be limited to small but statistically significant increases in the rate of RNA synthesis. However, inhibition of DNA, RNA and protein synthesis in these cells had no effect on the stimulation of ChAT activity by either sodium butyrate or retinoic acid. Several experiments appeared to rule out a role for cyclic AMP or protein kinase C in the regulation of ChAT activity, even though retinoic acid treatment could increase endogenous levels of cyclic AMP 3- to 4-fold over the time course of ChAT activity stimulation. Experiments performed to determine kinetic parameters of this enzyme demonstrated changes only in the Vmax, but not the Km of ChAT, suggesting that the affinity of enzyme for either of its substrates was not responsible for the increase in specific activity. Taken together, this evidence suggests that the activation of choline acetyltransferase in this human neuroblastoma cell line occurs at the post-translational level.

Lactational responses of dairy cows to diets containing regular and high oleic acid sunflower seeds.

Ten Holstein cows were used in a 15-wk nested factorial to evaluate the response to diets containing added fat from sunflower seeds high (greater than 65%) in linoleic acid (regular sunflower seeds) or high (80%) in oleic acid (high oleic acid variety sunflower seeds). Replicated periods were of 5 wk each, with data collected the last 3 wk of each period. Total mixed diets were 40% corn silage (DM basis), 15% alfalfa hay, and 45% concentrate mix. Concentrate mixes were control, 20% regular sunflower seeds, or 20% high oleic acid sunflower seeds in place of portions of the corn and soybean meal. Yields of milk (27.9, 25.4, and 28.8 kg/d) were similar for all diets, while 4% FCM (24.0, 19.2, and 24.0 kg/d) and SCM (24.8, 20.2, and 24.8 kg/d) were lower when cows were fed regular sunflower seeds. Percentages of fat (3.14, 2.43, and 2.92%) were reduced when cows were fed regular sunflower seeds, but protein (3.00, 3.24, and 3.03%) and total solids (12.12, 11.34, and 11.82%) were similar for all diets. Milk fat from cows fed regular sunflower seeds contained the highest proportions of unsaturated fatty acids with the lowest proportions from cows fed the control diet. Dry matter intakes (22.8, 20.6, and 21.9 kg/d) were similar. Molar percentages of ruminal acetate were lower and propionate higher when cows were fed regular sunflower seeds than when fed high oleic acid sunflower seeds or control. The fatty acid composition of dietary fat influenced the fatty acid composition of cows milk.

Regulation of choline acetyltransferase activity by cell density in a cultured human neuroblastoma cell line.

Choline acetyltransferase (ChAT), the biosynthetic enzyme for acetylcholine metabolism, is expressed in a human cholinergic neuroblastoma cell line; MC-IXC. We demonstrate that ChAT activity is regulated in this cell line by cell density. It is believed that the mechanism of stimulation of enzyme activity involves cellular contact, as medium conditioned by cells of high density failed to mimic the effect of density alone, and trypsinization reversed this effect. Density did not increase acetylcholinesterase activity, another marker for the cholinergic phenotype, in MC-IXC cultures, demonstrating the independent regulation of these two cholinergic enzymes. Since increased density slows the rate of cell division, we used a DNA synthesis inhibitor to uncouple DNA replication from cell density. This had no effect on the specific activity of ChAT, suggesting that a cell-cell contact was the mediating factor. Other neuroblastoma cell lines were tested, and only cell lines which already contain ChAT activity were sensitive to its regulation by cell-cell contact, suggesting that cell-cell contact is permissive rather than instructive in this process. The effect of cell passage on ChAT activity is also discussed.

Evaluation of urea and dried whey in diets of cows during early lactation.

Thirty-three Holstein cows were fed one of three concentrate mixtures supplemented with all protein (soybean meal), 1% urea, or 1% urea and 30% dried whey from wk 3 through 16 postpartum. Total mixed rations contained 40% (dry matter basis) corn silage, 10% alfalfa hay, and 50% concentrate mixture. Diets were formulated to be isonitrogenous at 16% crude protein, but soluble nitrogen was formulated to be approximately 23, 30, and 42% of total nitrogen. Milk yield was similar (33.8, 33.4, and 33.2 kg/d) for cows fed the three diets, whereas production of 4% fat-corrected milk (29.9, 28.0, and 29.2 kg/d) and solids-corrected milk (30.3, 28.6, and 29.6 kg/d) was higher for cows fed soybean meal and urea-dried whey. Milk fat percentages (3.23, 2.94, and 3.23%) were lower when cows were fed urea, but milk protein (3.10, 3.04, and 3.04%) and solids-not-fat (8.74, 8.79, and 8.81%) were not affected by diet. Dry matter intakes (22.0, 20.2, and 23.1 kg/d) were highest for cows fed urea-dried whey and lowest for cows fed urea. Molar percentages of ruminal acetate (56.6, 50.3, and 50.2%) were highest for cows fed soybean meal, propionate (24.8, 28.6, and 25.0%) was highest for cows fed urea, and butyrate (13.6, 14.4, and 18.4%) was highest for cows fed urea-dried whey. Concentrations of ruminal ammonia (11.8, 20.3, and 13.5 mg/dl) and serum urea (19.5, 22.9, and 16.5 mg/dl) were highest for cows fed urea. Utilization of urea nitrogen for milk production was improved by adding dried whey to diets of early lactation cows.

Familial simple ectopia lentis: a case study.

Hereditary simple ectopia lentis affected nine patients in three generations of a family. Inheritance appeared to be autosomal dominant. Examination of 12 family members, employing body proportion measurements, chest x-ray, echocardiogram, and urinary cystine or blood methionine levels, revealed no evidence of any systemic disease. In all cases except two, lenses were bilaterally and superiorly dislocated. The degree of dislocation varied considerably among those affected, causing no visual disturbance in some and severely limiting visual acuity in others. Visual deficits were greatest in patients with intermediate degrees of dislocation. To date, the only known complications related to the dislocations have been two cases of bilateral cataracts. The indications for lensectomy in patients with ectopia lentis are reviewed.