Uncontrolled blood pressure and risk of sleep apnea among blacks: findings from the Metabolic Syndrome Outcome (MetSO) study.

Uncontrolled blood pressure (BP) is linked to increased risk of obstructive sleep apnea (OSA). However, few studies have assessed the impact of this relationship among blacks with metabolic syndrome (MetS). Data for this study were collected from 1035 blacks (mean age=62±13 years) enrolled in the Metabolic Syndrome Outcome study. Patients with a score ⩾6 on the Apnea Risk Evaluation System were considered at risk for OSA. Of the sample, 77.1% were low-to-high OSA risk and 92.3% were hypertensive, of which 16.8% had uncontrolled BP levels. Analysis also showed that 60.4% were diabetic, 8.9% had a stroke history, 74.3% had dyslipidemia, 69.8% were obese and 30.9% had a history of heart disease. Logistic regression analyses were employed to investigate associations between uncontrolled BP and OSA risk, while adjusting for known covariates. Findings showed that uncontrolled BP independently increased the odds of OSA risk twofold (odds ratio=2.02, 95% confidence interval=1.18-3.48, P<0.05). In conclusion, our findings show that uncontrolled BP was associated with a twofold greater risk of OSA among blacks, suggesting that those with MetS and who have uncontrolled BP should be screened for the presence of OSA.

Survey of management of common iliac artery aneurysms by members of the Vascular Society of Great Britain and Ireland.

INTRODUCTION: The aim of this study was to determine whether the current management of common iliac artery aneurysms (CIAAs) by vascular surgeons is in tune with existing guidelines for referral. METHODS: This was a postal survey of members of the Vascular Society of Great Britain and Ireland. The main outcome measures were relative frequency of ruptured CIAA, respondents' size threshold for surveillance versus intervention, and their management strategies for isolated unilateral CIAAs, bilateral CIAAs and aortoiliac aneurysms. RESULTS: Two hundred and eighty-four (anonymous) replies were received (48% response rate). Respondents estimated that a ruptured abdominal aortic aneurysm (AAA) was 25 times more common than a ruptured CIAA. Most surgeons (64%) would wait until a CIAA reached 4 cm in diameter before considering intervention. This threshold was not affected by other scenarios such as the presence of a bilateral CIAA or a small (4 cm) AAA. Eighty per cent of surgeons would treat a non-ruptured CIAA by stenting, where possible. The majority of surgeons felt that ultrasonography surveillance should be commenced when a CIAA exceeds 1.5 cm, with a surveillance interval of 1 year but with more frequent surveillance for CIAAs wider than 3 cm. CONCLUSIONS: Existing guidelines that recommend referral for possible intervention for non-ruptured CIAAs at a diameter of 3 cm are out of tune with current practice. Most surgeons in this survey would wait until the diameter was 4 cm.

Effects of packaging systems and fat concentrations on microbiology, sensory and physical properties of ground beef stored at 4±1°C for 25 days.

This study evaluated effects of modified atmosphere (MAP, 0.4% carbon monoxide [CO], 30% carbon dioxide, and 69.6% nitrogen), vacuum (VP) and polyvinyl chloride (PVC) packaging systems and fat levels (10, 20 and 30% fat) on ground beef stored at 4 ± 1°C for 25 days for microbiology, sensory, pH, thiobarbituric acid reactive substances (TBARS), objective color, headspace and residual CO. As storage time increased, pH decreased (P< 0.05) for MAP and VP and increased (P < 0.05) for PVC. TBARS varied (P < 0.05) among MAP and VP treatments. Except for day 1, CO headspace concentrations were similar among fat concentrations, and residual CO absorption in meat increased (P < 0.05) for all MAP treatments. In all treatments, degree of lightness was similar, redness decreased and brown discoloration increased during storage. As psychrotrophic bacteria counts increased, panelists detected color and off-odor deterioration in all systems. The CO treatment had no effect on maintaining the carboxymyoglobin "cherry red" fresh meat color during meat spoilage.

Quantification of hepatic FOXP3+ T-lymphocytes in HIV/hepatitis C coinfection.

Coinfection with HIV adversely impacts every stage of hepatitis C (HCV) infection. Liver damage in HCV infection results from host antiviral responses rather than direct viral pathogenesis. Despite depressed cellular immunity, coinfected patients show accelerated hepatic fibrosis compared with HCV monoinfected patients. This paradox is poorly understood. T-regulatory (Treg) cells (CD4+ and FOXP3+) are hypothesized to limit hepatic damage in HCV. Our hypothesis was that reduced frequency of hepatic Treg in HIV/HCV coinfection compared with HCV monoinfection may explain poorer outcomes. We quantified FOXP3+, CD4+, CD8+ and CD20+ cells in liver biopsies of 35 male subjects matched by age and ISHAK fibrosis score, 12 HIV monoinfected, 11 HCV monoinfected and 12 HIV/HCV coinfected. Cell counts were performed using indirect immunohistochemical staining and light microscopy. HIV/HCV coinfected subjects had fewer hepatic FOXP3+ (P = 0.031) and CD4+ cells (P = 0.001) than HCV monoinfected subjects. Coinfected subjects had more hepatic CD8+ cells compared with HCV monoinfected (P = 0.023), and a lower ratio of FOXP3+ to CD8+ cells (0.08 vs 0.27, P < 0.001). Multivariate analysis showed number of CD4+ cells controlled for differences in number of FOXP3+ cells. Fewer hepatic FOXP3+ and CD4+ cells in HIV/HCV coinfection compared with HCV monoinfection suggests lower Treg activity, driven by an overall loss of CD4+ cells. Higher number of CD8+ cells in HIV/HCV coinfection suggests higher cytotoxic activity. This may explain poorer outcomes in HIV/HCV coinfected patients and suggests a potential mechanism by which highly active antiretroviral therapy may benefit these patients.

Prenatal and gestational cocaine exposure: Effects on the oxytocin system and social behavior with implications for addiction.

Drug abuse during pregnancy is a major public health concern, with negative consequences throughout development. Prenatal cocaine exposure (PCE) in rats produces social behavior deficits with corresponding changes in neuroendocrine and monoaminergic signaling. The relevance of parental care in social behavior maturity cannot be ignored, and gestational exposure to cocaine severely disrupts parental care, thus impacting the early environment of the offspring. Oxytocin (Oxt) is critical in regulating social behaviors and central levels are disrupted following acute and chronic cocaine (CC) treatment in postpartum rat dams, coincident with deficits in maternal care. We will discuss studies aimed to determine the relative contribution of PCE and CC-induced deficits in maternal care to social behaviors and Oxt signaling across development. PCE results in decreased social (including parental) behaviors in adolescence and adulthood. PCE is also associated with increased aggression in adults. Rearing by CC-exposed mothers synergistically increases the behavioral effects of PCE. Rearing by CC-exposed mothers, but not PCE, disrupts Oxt levels and mRNA in regions relevant to social behavior, but does not affect receptors in postpartum adult offspring. Preliminary work indicates that PCE/CC rearing has dynamic effects on Oxt levels and receptors in neonatal rat pups, suggesting very early regulation of Oxt signaling. This work highlights how the interactive role of Oxt signaling and behavioral context throughout development can be derailed by drug abuse during pregnancy. The relevance of disrupted Oxt to intergenerational transmission of addiction is briefly discussed.

Generation of a functional liver tissue mimic using adipose stromal vascular fraction cell-derived vasculatures.

One of the major challenges in cell implantation therapies is to promote integration of the microcirculation between the implanted cells and the host. We used adipose-derived stromal vascular fraction (SVF) cells to vascularize a human liver cell (HepG2) implant. We hypothesized that the SVF cells would form a functional microcirculation via vascular assembly and inosculation with the host vasculature. Initially, we assessed the extent and character of neovasculatures formed by freshly isolated and cultured SVF cells and found that freshly isolated cells have a higher vascularization potential. Generation of a 3D implant containing fresh SVF and HepG2 cells formed a tissue in which HepG2 cells were entwined with a network of microvessels. Implanted HepG2 cells sequestered labeled LDL delivered by systemic intravascular injection only in SVF-vascularized implants demonstrating that SVF cell-derived vasculatures can effectively integrate with host vessels and interface with parenchymal cells to form a functional tissue mimic.

Sodium metasilicate affects growth of Campylobacter jejuni in fresh, boneless, uncooked chicken breast fillets stored at 4 degrees Celsius for 7 days.

The objectives of this study were to determine the antimicrobial effects of sodium metasilicate (SMS) treatments against Campylobacter jejuni in fresh, boneless, uncooked chicken breast fillets and to ascertain the effects of SMS treatments on pH. The fillets were inoculated with C. jejuni, treated with 0% SMS and no inoculum (negative control), 0% SMS and inoculum (positive control), 1 and 2% SMS solutions, and stored at 4 ± 1°C. All samples were analyzed after 0, 1, 3, 5, and 7 d storage for C. jejuni, psychrotrophic organisms, and pH. Campylobacter jejuni and psychrotrophic counts for samples treated with 1 and 2% SMS solutions were similar (P > 0.05) to the positive control on all storage days. The pH values for 2% SMS marinade treatments were higher (P < 0.05) when compared with the negative and positive controls through 7 d of storage. Based on the findings in this study, a second study was conducted to determine the level of SMS necessary to reduce C. jejuni by at least 1 log cfu/g. The treatments were the same as previously discussed, except SMS was used at levels of 1 and 2% of the weight of the meat instead of percentage of the solution. Chicken fillets treated with 1 and 2% SMS (by weight of meat) resulted in 1.12 to 1.26 and 3.27 to 3.79 log cfu/g reductions in C. jejuni, respectively, when compared with the positive control. Except for d 0, psychrotrophic counts for samples treated with 2% SMS were lower (P < 0.05) than negative and positive controls on all storage days. The pH values were higher (P < 0.05) for all SMS treatments when compared with the negative and positive controls. This study revealed that SMS, when used at elevated levels in excess of the USDA Food Safety and Inspection Service 2% approved level, could function to control Campylobacter jejuni and extend the shelf life of raw poultry by retarding the growth of psychrotrophic bacteria.

Chronic cocaine exposure during pregnancy increases postpartum neuroendocrine stress responses.

The cycle of chronic cocaine (CC) use and withdrawal results in increased anxiety, depression and disrupted stress-responsiveness. Oxytocin and corticosterone (CORT) interact to mediate hormonal stress responses and can be altered by cocaine use. These neuroendocrine signals play important regulatory roles in a variety of social behaviours, specifically during the postpartum period, and are sensitive to disruption by CC exposure in both clinical settings and preclinical models. To determine whether CC exposure during pregnancy affected behavioural and hormonal stress response in the early postpartum period in a rodent model, Sprague-Dawley rats were administered cocaine daily (30 mg/kg) throughout gestation (days 1-20). Open field test (OFT) and forced swim test (FST) behaviours were measured on postpartum day 5. Plasma CORT concentrations were measured before and after testing throughout the test day, whereas plasma and brain oxytocin concentrations were measured post-testing only. The results obtained indicated increased CORT response after the OFT in CC-treated dams (P ≤ 0.05). CC-treated dams also exhibited altered FST behaviour (P ≤ 0.05), suggesting abnormal stress responsiveness. Peripheral, but not central, oxytocin levels were increased by cocaine treatment (P ≤ 0.05). Peripheral oxytocin and CORT increased after the FST, regardless of treatment condition (P ≤ 0.05). Changes in stress-responsiveness, both behaviourally and hormonally, may underlie some deficits in maternal behaviour; thus, a clearer understanding of the effect of CC on the stress response system may potentially lead to treatment interventions that could be relevant to clinical populations. Additionally, these results indicate that CC treatment can have long-lasting effects on peripheral oxytocin regulation in rats, similar to changes observed in persistent social behaviour and stress-response deficits in clinical populations.

Sodium metasilicate affects growth of Salmonella Typhimurium in fresh, boneless, uncooked chicken breast fillets stored at 4°C for 7 days.

The objectives of this study were to determine the antimicrobial effects of sodium metasilicate (SMS) against Salmonella and psychrotrophic organisms in fresh, boneless, uncooked chicken breast fillets and to ascertain the effects of SMS treatments on pH. Chicken breast fillets were inoculated with Salmonella enterica serovar Typhimurium treated with 0% SMS and no inoculum (negative control), 0% SMS and inoculum (positive control), 1% SMS, or 2% SMS solutions and stored at 4 ± 1°C. All samples were analyzed after 0, 1, 3, 5, and 7 d for Salmonella, psychrotrophic organisms, and pH. The fillets that were treated with 1 or 2% SMS had lower (P < 0.05) Salmonella counts as compared with those of the positive control at 3 through 7 d. Reductions in Salmonella Typhimurium were 0.83 to 0.91 log cfu/g and 1.04 to 1.16 log cfu/g for 1 and 2% SMS treatments, respectively. The psychrotrophic counts were similar (P > 0.05) for all treatments. The pH values for samples treated with 1 or 2% SMS were higher (P < 0.05) when compared with those of the negative and positive controls. This study revealed that SMS could restrict the growth of pathogenic Salmonella Typhimurium in fresh poultry.

Cellular immunoisolation for islet transplantation by a novel dual porosity electrospun membrane.

Immunoisolation strategies have the potential to impact the treatment of several diseases, such as hemophilia, Parkinson's and endocrine disorders, such as parathryroid disorders and diabetes. The hallmark of these disease states is the amelioration of the disease process by replacement of the deficient protein. Naturally, several cellular therapeutic strategies like genetically modified host cells, stem cells, donor cells, or even complex tissues like pancreatic islets have been investigated. Current evidence suggests that successful strategies must incorporate considerations for local hypoxia, vascularity, and immunoisolation. Additional regulatory concerns also include safe localization of implanted therapeutic cells to allow for monitoring, dose adjustment, or removal when indicated. Local hypoxia and cellular toxicity can be detrimental to the survival of freshly implanted pancreatic islets, leading to a need for a larger initial number of islets or repeated implantation procedures. The lack of adequate donors and the large number of islet equivalents needed to achieve euglycemic states amplify the nature of this problem. We have developed a novel immunoisolation device based on electrospun nylon, primarily for islet transplantation, such that the inner component functions as a cellular barrier while allowing diffusion, whereas the outer component can be optimized for tissue integration and accelerated vascularization. Devices explanted after subcutaneous implantation in wild-type B6 mice after a period of 30 days show vascular elements in the outer layer of the electrospun device. The inner layer when intact functioned as an effective barrier to cellular infiltration. The preimplantation of such a device, with a relatively thin inner barrier membrane, will allow for adequate vascularization and reduce postimplantation hypoxia. This study demonstrates the feasibility of an electrospun isolation device that can be easily assembled, modified by varying the electrospinning parameters, and functionalized with surface-active molecules to accelerate vascularization.

Sodium metasilicate affects antimicrobial, sensory, physical, and chemical characteristics of fresh commercial chicken breast meat stored at 4° C for 9 days.

The objectives of this study were to investigate antimicrobial properties of sodium metasilicate (SMS) on fresh boneless and skinless commercial broiler chicken breast fillets, and to ascertain effects of the treatments on sensory, chemical, and physical characteristics of the meat. Fillets were divided into 5 groups, weighed, treated with 0, 1, 2, 3, or 4% SMS marinades, vacuum tumbled at 172.32 kPa for 20 min, reweighed, packaged in styrofoam trays, stored at 4°C for 9 d, and analyzed at 0, 1, 3, 5, 6, 7, and 9 d for marination yield (d 0 only), pH, total psychrotrophic counts, water-holding capacity, purge loss, cooking yield, and objective texture, color, and sensory characteristics. Marination yield and water-holding capacity were similar (P > 0.05) among all SMS treatments and increased by 3 to 4% compared with that in control fillets. Fillets treated with at least 3% SMS had higher (P < 0.05) pH and cooking yields and lower (P < 0.05) purge loss (on d 9) compared with control fillets. The 3 and 4% SMS treatments retarded growth of psychrotrophic organisms for 1 additional day compared with control, 1, and 2% SMS-treated fillets. Color and texture measurements and sensory characteristics of the fillets were not adversely affected by the SMS treatments. The data in this study revealed that at least 3% SMS was necessary to retard growth of spoilage bacteria compared with untreated samples and samples treated with the USDA maximum allowable level of 2% SMS in poultry marinades.

Life after lower extremity amputation in diabetics.

UNLABELLED: Lower limb amputees typically have reduced mobility which affects their ability to perform daily tasks and to successfully reintegrate into community life. A major goal of rehabilitation for amputees is to improve quality of life (QOL). This study therefore focussed on QOL and functional independence for persons with lower limb amputations secondary to diabetes. OBJECTIVE: To determine the QOL and functional independence of lower limb diabetic amputees one to three years post amputation, using variables such as age, gender and amputation level. METHOD: A total of 87 participants were selected from the 2006-2009 physiotherapy records at the St Ann's Bay Hospital. These participants completed the World Health Organization Quality of Life Scale (WHO QOL-BREF) and the Functional Independence Measure (FIM). Data were analysed using SPSS (version 12) and the mean values for QOL and functional independence were calculated. Relationships between the variables: age, gender and level of amputation with QOL and functional independence were analysed using descriptive and inferential statistical techniques. RESULTS: Among the 35 males and 52 females participating in the study, below knee amputees recorded higher scores for QOL (p < 0.05) and functional independence (p < 0.0001) compared to the above knee amputees. The result also showed that females had a significantly higher average score than males among the four domains for QOL. Similar results were obtained from the FIM where women again had significantly higher scores than males (p < 0.0001). The majority of females across the age groups reported average to high QOL (p < 0.0001) compared to the males. A positive correlation (r = 0.5999, p < 0.0001) was found between functional independence and quality of life of all participants. CONCLUSION: The results showed that below knee amputees functioned better than those with above knee amputations and that females were more likely to cope and function with the disability than males.

Control of Escherichia coli O157:H7 in corn silage with or without various inoculants: efficacy and mode of action.

This study aimed to evaluate the effectiveness of 3 commercial bacterial inoculants at controlling Escherichia coli O157:H7 in corn silages during ensiling and feedout phases of silage production. A second objective was to determine whether the inoculants exhibited and transferred antibacterial activity against E. coli O157:H7 to the silages. Chopped corn forage was ensiled after treatment with the following: distilled water (control); 5 x 10(5) cfu/g of E. coli O157:H7 (EC); EC and 1 x 10(6) cfu/g of Pediococcus pentosaceus and Propionibacterium freudenreichii (EC+BII); EC and 1 x 10(6) cfu/g of Lactobacillus buchneri (EC+LB); and EC and 1 x 10(6) cfu/g of L. buchneri and P. pentosaceus (EC+B500). Each treatment was ensiled in triplicate in mini silos for 3, 7, 31, and 82 d and analyzed for pH and E. coli O157:H7 counts. Samples from d 82 were also analyzed for volatile fatty acids, lactate, and aerobic stability. Antibacterial activity of inoculants and silages was determined by the Kirby-Bauer disc diffusion test. The pH of silages from all treatments decreased below 4 within 3 d of ensiling and remained low until d 82. Therefore, E. coli O157:H7 was not detected in silages after any of the ensiling durations. Applying inoculants containing L. buchneri resulted in less lactate, more acetate, and greater aerobic stability compared with the control. Applying EC+BII containing P. freudenreichii did not increase propionate or aerobic stability. Subsamples of d 82 silages were reinoculated with 1 x 10(5) cfu/g of E. coli O157:H7 either immediately after silo opening on d 82 or after 144h of aerobic exposure (d 88), and E. coli were enumerated 24h later. All silages reinoculated with the pathogen on d 82 had similar, low pH values (<4) and no E. coli were detected 24h later. Control, EC, and EC+BII silages reinoculated with the pathogen after 144h of aerobic exposure had relatively greater pH values (4.71, 5.67, and 6.03, respectively) and E. coli counts (2.87, 6.73, and 6.87 log cfu/g, respectively) 24h later, whereas those treated with L. buchneri had low pH values (<4) and undetectable (EC+B500) or 10-fold lower (1.97, cfu/g; EC+LB) E. coli counts. All pure cultures of commercial bacterial inoculants exhibited antibacterial activity independent of pH against E. coli O157:H7, but the pH-independent activity did not persist in the treated silages, suggesting that E. coli elimination from silages was mediated by pH reduction.

Sodium diacetate and sodium lactate affect microbiology and sensory and objective characteristics of a restructured turkey breast product formulated with a fibrin cold-set binding system.

Research was conducted to manufacture and evaluate a restructured turkey breast product using the Fibrimex cold-set binding system, sodium diacetate (NaD), and sodium lactate (NaL) and to ascertain effects of the treatments on proximate composition, pH, psychrotrophic organisms, water activity, onset of rancidity (TBA), thaw loss, cooking yields, and objective color, and sensory characteristics. Whole turkey breasts were cut into 5-cm-thick strips; treated with either water only (control), 1.5% NaL, 2.0% NaL, 0.1% NaD, 1.5% NaL + 0.1% NaD, or 2.0% NaL + 0.1% NaD; blended with Fibrimex ingredients; stuffed into casings; and stored at -30 degrees C for 0, 1, 2, and 3 mo. After each storage period, frozen chubs were tempered at 4 degrees C, sliced into 1-cm-thick steaks, packaged in retail trays, stored at 0 degrees C to simulate retail storage, and analyzed after 0, 2, 4, 6, 8, and 10 d. Sodium diacetate used alone or in combination with NaL reduced (P < 0.05) growth of psychrotrophic organisms and had no adverse effects on water activity, pH, cooking yield, fat, moisture, protein, objective color, onset of rancidity, and sensory characteristics (juiciness, turkey flavor intensity, and tenderness). Panelists reported slight off-flavor in all steaks treated with NaL. Treating steaks with NaL alone or in combination with NaD resulted in increased (P < 0.05) ash content. Sodium lactate also functioned to minimize thaw loss in the frozen restructured turkey product.

Nisin affects the growth of Listeria monocytogenes on ready-to-eat turkey ham stored at four degrees Celsius for sixty-three days.

The objectives of this study were to determine pH, anti-Listeria and general antimicrobial properties of nisin on ready-to-eat vacuum-packaged diced turkey ham inoculated with Listeria monocytogenes, and the usage level that would exert maximum antimicrobial effect during 63 d of storage. Ready-to-eat diced turkey ham was inoculated with a 5-strain L. monocytogenes cocktail; treated with 0.2, 0.3, 0.4, and 0.5% nisin treatment solutions; vacuum-packaged; stored at 4+/-1 degrees C for 63 d; and analyzed at 1-wk intervals for total aerobic counts, pH, L. monocytogenes, and lactic acid bacteria. Antimicrobial effectiveness of nisin increased as concentration increased from 0.2 to 0.5%. Aerobic plate counts for 0.4 and 0.5% nisin were lower (P<0.05) than negative and positive controls. All nisin treatments resulted in 4 log reductions (P<0.05) in L. monocytogenes when compared with the positive control on d 0. Four log reductions were also observed on d 7 for 0.4% nisin treatment and d 7 and 14 for 0.5% nisin treatment when compared with the positive control. Listeria monocytogenes counts decreased from 4.97 log cfu/g on d 0 and remained less than 2 log cfu/g through 63 d of storage for the 0.5% nisin treatment. Lactic acid bacteria counts were lower (P<0.05) for 0.5% nisin treatment when compared with positive and negative controls from 28 through 63 d. Except for d 56 and 63, pH was similar (P<0.05) for all treatments. This study revealed that nisin could be used for postprocessing intervention to control L. monocytogenes in ready-to-eat poultry products.

Factors associated with academic performance of physical therapy students.

UNLABELLED: Understanding the pre-matriculation factors that influence academic success facilitates the recruitment and retention of students who are more likely to graduate on time. OBJECTIVE: To determine the factors associated with the academic performance of students enrolled in the physical therapy diploma programme. METHODS: Records of 250 students enrolled over a twenty-year period at the School of Physical Therapy were reviewed. Data were collected and organized using a data collection sheet. Data were analysed using the Statistical Package for the Social Sciences (SPSS). Relationships between the independent variables: age, gender marital status, work history and entry qualifications, and the dependent variables: academic performance (percentage of subjects passed at the first sitting of examinations and success in the Final Qualifying Examination), withdrawal and delayed graduation were examined using correlation coefficient, t-test, ANOVA and chi-square as appropriate. RESULTS: Results revealed that students gaining the minimum entry qualifications at one sitting of GCE O' Level/CXC examinations (p < 0.01) and who had GCE A' Level passes (p < 0.05) were less likely to withdraw from the programme. Students without prior work experience performed better during the course of study (p < 0.05) but the older and married students were more likely to withdraw (p < 0.01). Older students performed better on the Final Qualifying Practical and Theory Examinations taken at the end of the academic programme (p < 0.05) but had a lower percentage of subjects passed at the first sitting of course examinations (p < 0.05). CONCLUSION: Students with better academic preparation demonstrated better academic performance. These findings were consistent with prior studies in the field.

Some Listeria monocytogenes outbreak strains demonstrate significantly reduced invasion, inlA transcript levels, and swarming motility in vitro.

Listeria monocytogenes can cause a severe invasive food-borne disease known as listeriosis, and large outbreaks of this disease occur occasionally. Based on molecular-subtype data, epidemic clone (EC) strains have been defined, including ECI and ECIa, which have caused listeriosis outbreaks on different continents. While a number of molecular-subtyping studies of outbreak strains have been reported, few comprehensive data sets of virulence-associated characteristics of these strains are available. We assembled a set of human clinical isolates from 15 outbreaks that occurred worldwide between 1975 and 2002. Initial characterization of these strains showed significant variation in the ability to invade human Caco-2 intestinal epithelial cells and HepG2 hepatic cells; four strains showed consistently reduced invasion in both cell lines. DNA sequencing of inlA, which encodes a protein required for efficient Caco-2 and HepG2 invasion, showed that none of the invasion-attenuated strains contained known virulence-attenuating mutations in inlA. Phylogenetic analyses of inlA sequences revealed a well-supported clade containing a fully invasive ECI strain and three invasion-attenuated ECI strains, along with a fully invasive ECIa strain and an invasion-attenuated ECIa strain. Of the four invasion-attenuated strains, one strain showed both reduced inlA transcript levels and impaired swarming, one strain showed reduced inlA transcript levels, and two strains showed reduced swarming. Overall, our data show that (i) L. monocytogenes strains from outbreaks vary significantly in invasion efficiency and (ii) different mechanisms may contribute to reduced invasion efficiency. Association between EC strains and listeriosis outbreaks may involve characteristics other than virulence phenotypes, including survival and growth in food-associated environments.

Nisin, rosemary, and ethylenediaminetetraacetic acid affect the growth of Listeria monocytogenes on ready-to-eat turkey ham stored at four degrees Celsius for sixty-three days.

The objectives of this study were to determine the anti-Listeria and general antimicrobial properties of nisin, rosemary, and EDTA alone and in combination on Listeria monocytogenes inoculated on ready-to-eat vacuum-packaged diced turkey ham and to ascertain the effects of the treatments on pH and objective color. The turkey hams were cut into 0.5-cm pieces, inoculated with a L. monocytogenes cocktail containing 5 strains of the bacterium, and treated with either no treatment and no inoculum (negative control), inoculum only (positive control), 0.5% nisin, 20 mM EDTA, 1% rosemary, 0.5% nisin + 20 mM EDTA, 0.5% nisin + 1% rosemary, 0.5% nisin + 20 mM EDTA + 1% rosemary, or 20 mM EDTA + 1% rosemary. All samples were vacuum-packaged, stored for 63 d at 4 degrees C +/- 1 degrees C, and analyzed at 1-wk intervals for total aerobes, L. monocytogenes, lactic acid organisms, pH, and objective color. Nisin, nisin with rosemary, nisin with EDTA, and nisin with rosemary and EDTA treatments reduced (P < 0.05) L. monocytogenes counts by 4.42, 4.20, 3.73, and 4.11 log cfu/g when compared with the positive control, respectively, on d 0. Listeria monocytogenes counts remained less than 2.75 log cfu/g for all hams treated with nisin. The EDTA and rosemary treatments alone and in combination were ineffective in inhibiting growth of L. monocytogenes. Although none of the treatments completely eliminated L. monocytogenes, the results indicated that ready-to-eat turkey ham can have significantly decreased L. monocytogenes when treated with nisin alone or in combination with rosemary or EDTA, or both.

Gestational ethanol and nicotine exposure: effects on maternal behavior, oxytocin, and offspring ethanol intake in the rat.

Alcohol consumption and smoking during pregnancy is common, despite the known adverse effects of these drugs on fetal development. Though studies on the effects of each drug separately are published, little is known about the effect of concurrent use of alcohol and nicotine in humans or in preclinical models. In this report, we examined the impact of continuous gestational exposure to both ethanol via liquid diet and nicotine via an osmotic minipump on maternal behavior, offspring ethanol intake, and oxytocin levels in a rat model. Dams were tested for the onset of maternal behavior with litters of unexposed surrogate pups and then killed to examine oxytocin levels within specific brain regions. Drug-exposed offspring reared by surrogate dams were tested for ethanol intake at either adolescence or adulthood, and oxytocin levels were measured in relevant brain regions after behavioral tests. Dams exhibited minor deficits in maternal care, which were associated with lower oxytocin levels in both the ventral tegmental and medial preoptic areas compared to control dams. Prenatal exposure altered sex-specific ethanol intake, with differential effects at adolescence and adulthood. Oxytocin system changes were also apparent in the ventral tegmental and medial preoptic regions of drug-exposed adolescent and adult offspring. These results suggest that dam treatment with ethanol and nicotine can somewhat negatively affect the early rearing environment, and that prenatal exposure to both of these drugs results in drinking behavior differing from what would be expected from either drug alone. Oxytocin's possible involvement in the mediation of these effects is highlighted.

Impact of gestational cocaine treatment or prenatal cocaine exposure on early postpartum oxytocin mRNA levels and receptor binding in the rat.

Prior research reported decreased oxytocin levels in specific brain regions correlated with disruptions in maternal care following gestational cocaine treatment in rats. Similarly, prenatal exposure to cocaine impaired subsequent maternal behavior in adulthood, but behavioral alterations were not associated with decreases in oxytocin levels in the same brain regions as were found in their cocaine-treated rat dams. To determine if other aspects of the oxytocin system are disrupted by cocaine treatment or prenatal exposure to cocaine during critical time points associated with maternal care, oxytocin mRNA transcription and receptor binding were examined on postpartum day two in relevant brain regions following gestational treatment with, or prenatal exposure to, either cocaine or saline. We hypothesized that oxytocin mRNA levels and receptor binding would be differentially affected by cocaine in the early postpartum period of dams and their offspring. Our findings indicate that gestational cocaine treatment resulted in significant increases in oxytocin mRNA levels in only the paraventricular nucleus of cocaine-treated dams, with almost significant increases in both generations in the supraoptic nucleus, but no significant effects of cocaine on receptor binding in either generation of dams. These findings indicate that in addition to oxytocin levels, cocaine treatment or prenatal exposure primarily affects oxytocin mRNA synthesis, with little effect on receptor binding in specific brain regions associated with maternal behavior in the early postpartum period of the rat.