Randomized, Double-Blind Placebo-Controlled Trial to Assess the Effect of Probiotics on Irritable Bowel Syndrome in Veterans With Gulf War Illness.

Background: Many veterans who served in Operation Desert Storm (August 1990 to March 1991) experienced a complex of symptoms of unknown etiology called Gulf War illness (GWI), which significantly impacts the health and quality of life (QOL) and may have contributed to irritable bowel syndrome (IBS). Methods: We performed a prospective, double-blind placebocontrolled study to determine the efficacy of the multistrain De Simone Formulation probiotic containing 8 strains of bacteria on symptoms of IBS and GWI. Veterans of Operation Desert Storm who had IBS and ≥ 2 nonintestinal symptoms of GWI were included. The primary study endpoint was change in bowel symptom score. The secondary endpoints were mean change in symptoms, QOL, and extra-intestinal and posttraumatic stress disorder (PTSD) symptoms. Results: A total of 101 Gulf War veterans with IBS and GWI were screened at the Veteran Affairs Medical Center in Salt Lake City, Utah. The study was completed by 53 veterans; 47 (89%) were male with a mean (SD) age of 55 (8) years. The probiotic did not improve IBS symptoms or other extra-intestinal symptoms common to IBS and GWI. Conclusions: Our study did not demonstrate statistically significant improvement in IBS symptoms or QOL after treatment with the probiotic. We also did not find any improvement in symptoms of GWI or PTSD.

Data standards for interoperability of care team information to support care coordination of complex pediatric patients.

OBJECTIVE: Seamless access to information about the individuals and organizations involved in the care of a specific patient ("care teams") is crucial to effective and efficient care coordination. This is especially true for vulnerable and complex patient populations such as pediatric patients with special needs. Despite wide adoption of electronic health records (EHR), current EHR systems do not adequately support the visualization and management of care teams within and across health care organizations. Electronic health information exchange has the potential to address this issue. In the present study, we assessed the adequacy of available health information exchange data standards to support the information needs related to care coordination of complex pediatric patients. METHODS: We derived data elements from the information needs of clinicians and parents to support patient care teams; and mapped them to data elements in the Health Level Seven (HL7) Consolidated Clinical Document Architecture (C-CDA) standard and in the HL7 Fast Healthcare Interoperability Resources (FHIR) standard. We also identified additional C-CDA data elements and FHIR resources that include patients' care team members. RESULTS: Information about care team members involved in patient care is generally well-represented in the C-CDA and FHIR specifications. However, there are gaps related to patients' non-clinical events and care team actions. In addition, there is no single place to find information about care team members; rather, information about practitioners and organizations may be available in several different types of C-CDA data elements and FHIR resources. CONCLUSION: Through standards-based electronic health information exchange, it appears to be feasible to build patient care team representations irrespective of the location of patient care. In order to gather care team information across disparate systems, exchange of multiple C-CDA documents and/or execution of multiple FHIR queries will be necessary. This approach has the potential to enable comprehensive patient care team views that may help improve care coordination.

Antioxidant Activity of Yichun Blue Honeysuckle (YBHS) Berry Counteracts CCl4-Induced Toxicity in Liver Injury Model of Mice.

Yichun Blue Honeysuckle (YBHS) is reported to have a broad range of health benefits including protection against a number of chronic diseases. The objective of our study was to determine whether YBHS exhibits antioxidant activity, and if so, determine how it provides protection against oxidative stress. Eight-week old mice (25 male and 25 female) were randomized into five groups (n = 10 per group). YBHS extract (at 6.25%, 12.5%, or 25%) was administrated via intra-gastric tube to mice at 0.1 mL/10 g body weight once daily for 7 days. On the 8th day, all animals except for the controls received 250 mg/kg of CCl4 through an intra-gastric tube. The animals were sacrificed 6 h after CCl4 administration. Liver samples obtained from these mice were analyzed for the levels of Thiobarbituric Acid Reactive Substances (TBARS) and glutathione and the activities of Superoxide Dismutase (SOD), Catalase (CAT), and Glutathione Peroxidase (GPx), using biochemical assay kits. Our results showed that YBHS indeed reduces lipid peroxidation, suggesting that YBHS decreases the Reactive Oxygen Species (ROS) levels. We also found that YBHS activated the endogenous antioxidant enzymes including superoxide dismutase, catalase, and glutathione peroxidase and its co-enzyme glutathione reductase. In addition, we showed that glutathione levels were increased by YBHS treatment. Furthermore, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay revealed that YBHS has potent free radical scavenging activity. Based on the results from our study, we conclude that YBHS scavenges ROS by enhancing the activity of the endogenous antioxidant defense system activity for conferring liver protective effects.

Stabilizing endothelium of donor hearts with fusogenic liposomes reduces myocardial injury and dysfunction.

BACKGROUND: Myocardial injury after heart transplantation is a consequence of pathophysiologic events initiated by local ischemia/reperfusion injury that is further aggravated by the inflammatory response due to blood exposure to the pump's artificial surfaces during cardiopulmonary bypass. The purpose of the present study was to determine the effectiveness of fusogenic lipid vesicles (FLVs) in enhancing the cardioprotective effect of St. Thomas organ preservation solution (ST). We hypothesized that donor hearts preserved with ST+FLVs will stabilize the endothelium during reperfusion, which, in turn, will reduce both endothelial barrier dysfunction and myocardial damage. METHODS: To examine the effect of ST+FLVs therapy in vitro, C3b deposition and adhesion molecule expression studies were performed on human umbilical vein endothelial cells challenged with plastic contact-activated plasma. To assess the therapy in vivo, a cervical heterotopic working heart transplantation model in rats was used. Donor hearts were preserved for 1 h at 27°C (15 min) and 4°C (45 min) and, after transplantation, were followed up for 2 h. Left ventricular function and the blood cardiac troponin I levels were quantified. RESULTS: Human umbilical vein endothelial cells treated with ST+FLVs had reduced C3b deposition and expression of adhesion molecules compared with ST alone (P < 0.05). Donor hearts receiving ST+FLVs therapy had reduced left ventricular dysfunction and cardiac troponin I compared with ST alone. CONCLUSIONS: We concluded that FLVs enhanced the cardioprotective effect of ST and reduced postischemic left ventricular dysfunction and myocardial damage. The mechanism of protection appears to be associated with the stabilization of endothelial cell membranes owing to incorporation of FLV-derived lipids.

Clinical practice guideline: red blood cell transfusion in adult trauma and critical care.

OBJECTIVE: To develop a clinical practice guideline for red blood cell transfusion in adult trauma and critical care. DESIGN: Meetings, teleconferences and electronic-based communication to achieve grading of the published evidence, discussion and consensus among the entire committee members. METHODS: This practice management guideline was developed by a joint taskforce of EAST (Eastern Association for Surgery of Trauma) and the American College of Critical Care Medicine (ACCM) of the Society of Critical Care Medicine (SCCM). We performed a comprehensive literature review of the topic and graded the evidence using scientific assessment methods employed by the Canadian and U.S. Preventive Task Force (Grading of Evidence, Class I, II, III; Grading of Recommendations, Level I, II, III). A list of guideline recommendations was compiled by the members of the guidelines committees for the two societies. Following an extensive review process by external reviewers, the final guideline manuscript was reviewed and approved by the EAST Board of Directors, the Board of Regents of the ACCM and the Council of SCCM. RESULTS: Key recommendations are listed by category, including (A) Indications for RBC transfusion in the general critically ill patient; (B) RBC transfusion in sepsis; (C) RBC transfusion in patients at risk for or with acute lung injury and acute respiratory distress syndrome; (D) RBC transfusion in patients with neurologic injury and diseases; (E) RBC transfusion risks; (F) Alternatives to RBC transfusion; and (G) Strategies to reduce RBC transfusion. CONCLUSIONS: Evidence-based recommendations regarding the use of RBC transfusion in adult trauma and critical care will provide important information to critical care practitioners.

Shedding of foodborne pathogens by Caenorhabditis elegans in compost-amended and unamended soil.

A study was done to characterize the shedding of foodborne pathogenic bacteria by Caenorhabditis elegans, evaluate the persistence of worm populations cocultured with foodborne pathogens, and determine if C. elegans disperses ingested pathogens in soil as a result of shedding. Escherichia. coli O157:H7, Salmonella enterica serotype Poona, and Listeria monocytogenes, as well as E. coli OP50, a non-pathogenic strain, were studied. Synchronous populations of C. elegans were fed for 24 h on confluent lawns of nalidixic acid-adapted bacteria. C. elegans shed viable cells of ingested bacteria on tryptic soy agar supplemented with nalidixic acid (50 microg ml(-1)) (TSAN) throughout a 5-h post-feeding period. C. elegans persisted for up to 10 days by feeding on bacteria that had been shed and grew on TSAN. Eggs harvested from C. elegans cultured on shed foodborne pathogens had the same level of viability as those collected from C. elegans grown on shed E. coli OP50. After 6-7 days, 78%, 64%, 64%, and 76% of eggs laid by C. elegans that had fed on E. coli O157:H7, S. Poona, L. monocytogenes, and E. coli OP50, respectively, were viable. Worms fed on E. coli O157:H7 were inoculated into soil and soil amended with turkey manure compost. Populations of C. elegans persisted in compost-amended soil for at least 7 days but declined in unamended soil. E. coli O157:H7 was detected at 4 and 6 days post inoculation in compost-amended and unamended soil, and in unamended soil inoculated with E. coli OP50. Populations of E. coli O157:H7 in soil amended with turkey manure compost were significantly(alpha = 0.05) higher than those in unamended soil. Results indicate that C. elegans can act as a vector to disperse foodborne pathogens in soil, potentially resulting in increased risk of contaminating the surface of pre-harvest fruits and vegetables.

Diethylene glycol monomethyl ether, ethylene glycol monomethyl ether and the metabolite, 2-methoxyacetic acid affect in vitro chondrogenesis.

Diethylene glycol monomethyl ether (DEGME), ethylene glycol monomethyl ether (EGME) and their common metabolite, methoxyacetic acid (MAA) have been associated with adverse reproductive effects. The objective of this research is to investigate the effects of DEGME, EGME and MAA on in vitro chondrogenesis and the mechanisms by which these effects occur. Micromass cultures were exposed to DEGME, EGME or MAA for 5 days and proteoglycan abundance and cell proliferation determined. Longer-term 9- and 14-day cultures were exposed to MAA and apoptosis analyzed. All three chemicals decreased proteoglycan abundance and cell proliferation at the highest dose tested (100 microL/mL). However, only MAA showed a dose-dependent effect for both parameters at 0.01, 10, and 100 microL/mL. Furthermore, micromass cultures show an increase in apoptotic cells which when treated with MAA suggest that cell death could result from induced apoptosis. These results suggest that effects of DEGME and EGME are the result of generalized toxicity, but their metabolite MAA induces mitochondrial-mediated apoptosis during in vitro chondrogenesis.

Migration of Caenorhabditis elegans to manure and manure compost and potential for transport of Salmonella newport to fruits and vegetables.

A study was done to determine if a free-living, bacterivorous nematode, Caenorhabditis elegans, migrates to bovine manure, turkey manure, composted bovine manure, composted turkey manure, and manure-amended soil inoculated with Salmonella Newport. Movement of the worm to lettuce, strawberries, and carrots was also studied. C. elegans moved most rapidly to turkey manure and strawberries, with 35% and 60% of worms, respectively, associating with samples within 30 min. Survival and reproduction of C. elegans in test materials were not affected by the presence of S. newport. Bovine manure and bovine manure compost inoculated with S. newport (8.6 log10 CFU/g) were separately placed in the bottom of a glass jar and covered with a layer of soil (5 cm) inoculated (50 worms/g) or not inoculated with C. elegans. A piece of lettuce, strawberry, or carrot was placed on top of the soil before jars were sealed and held at 20 degrees C for up to 10 days. In the system using soil inoculated with C. elegans, S. newport initially in bovine manure was detected on the surface of lettuce, strawberry, and carrot samples within 3, 1, and 1 days, respectively. The pathogen was detected on lettuce, strawberry, and carrot within 1, 7, and 1 days, respectively, when initially present in bovine manure compost. With one exception, the pathogen was not detected on the produce over the 10-day incubation period when C. elegans was not present in the soil. Results indicate that C. elegans has the potential for transporting S. newport in soil to the surface of preharvest fruits and vegetables in contact with soil.

Potential role of Diploscapter sp. strain LKC25, a bacterivorous nematode from soil, as a vector of food-borne pathogenic bacteria to preharvest fruits and vegetables.

Diploscapter, a thermotolerant, free-living soil bacterial-feeding nematode commonly found in compost, sewage, and agricultural soil in the United States, was studied to determine its potential role as a vehicle of Salmonella enterica serotype Poona, enterohemorrhagic Escherichia coli O157:H7, and Listeria monocytogenes in contaminating preharvest fruits and vegetables. The ability of Diploscapter sp. strain LKC25 to survive on agar media, in cow manure, and in composted turkey manure and to be attracted to, ingest, and disperse food-borne pathogens inoculated into soil or a mixture of soil and composted turkey manure was investigated. Diploscapter sp. strain LKC25 survived and reproduced in lawns of S. enterica serotype Poona, E. coli O157:H7, and L. monocytogenes on agar media and in cow manure and composted turkey manure. Attraction of Diploscapter sp. strain LKC25 to colonies of pathogenic bacteria on tryptic soy agar within 10, 20, 30, and 60 min and 24 h was determined. At least 85% of the worms initially placed 0.5 to 1 cm away from bacterial colonies migrated to the colonies within 1 h. Within 24 h, > or =90% of the worms were embedded in colonies. The potential of Diploscapter sp. strain LKC25 to shed pathogenic bacteria after exposure to bacteria inoculated into soil or a mixture of soil and composted turkey manure was investigated. Results indicate that Diploscapter sp. strain LKC25 can shed pathogenic bacteria after exposure to pathogens in these milieus. They also demonstrate its potential to serve as a vector of food-borne pathogenic bacteria in soil, with or without amendment with compost, to the surface of preharvest fruits and vegetables in contact with soil.

Persistence of Escherichia coli O157:H7, Salmonella Newport, and Salmonella Poona in the gut of a free-living nematode, Caenorhabditis elegans, and transmission to progeny and uninfected nematodes.

A study was undertaken to determine the persistence of Escherichia coli O157:H7 and salmonellae in the gut of a free-living nematode, Caenorhabditis elegans, as affected by temperature and relative humidity and to determine if infected worms transmit Salmonella enterica serotype Newport to progeny and uninfected worms. Worms were fed cells of a non-pathogenic strain of E. coli (OP50), E. coli O157:H7, S. enterica serotype Newport, and S. enterica serotype Poona, followed by incubating at 4, 20, or 37 degrees C for up to 5 days. Initial populations of ingested pathogens significantly increased by up to 2.93 log(10) cfu/worm within 1 day at 20 degrees C on K agar and remained constant for an additional 4 days. When worms were placed on Bacto agar, populations of ingested pathogens remained constant at 4 degrees C, decreased significantly at 20 degrees C, and increased significantly at 37 degrees C within 3 days. Worms fed E. coli OP50 or S. Newport were incubated at 4 or 20 degrees C at relative humidities of 33%, 75%, or 98% to determine survival characteristics of ingested bacteria. Fewer cells of the pathogens survived incubation at 33% relative humidity compared to higher relative humidities. Populations of ingested E. coli OP50 and S. Newport decreased by up to 1.65 and 3.44 log(10) cfu/worm, respectively, in worms incubated at 20 degrees C and 33% relative humidity. Placement together on K agar of adult worms, labeled with green fluorescent protein (gfp) in the pharynx area, that had ingested gfp-labeled S. Newport and uninfected wild type worms resulted in transfer of the pathogen to gut of wild type worms. S. Newport was isolated from C. elegans two generations removed from exposure to the pathogen. Results of these studies show that C. elegans may serve as a temporary reservoir of foodborne pathogens, and could perhaps be a vector for contaminating preharvest fruits and vegetables, thus potentially increasing the risk of enteric infections associated with consumption of raw produce.

Effect of HTK on the microcirculation in the rat cremaster muscle during warm ischemia and reperfusion.

Histidine-tryptophan-ketoglutarate (HTK) preserves rat muscle function during cold storage. We examined the effect of HTK perfusion on preservation of microvascular function during 4 h of warm ischemia and subsequent reperfusion (I/R) in the rat cremaster muscle. Leukocyte-endothelium interactions, capillary perfusion, and arteriole diameters were quantified prior to HTK-perfusion and/or ischemia, and at 0, 1, and 2 h after restoration of blood flow. In all groups, the number of rolling leukocytes increased with time, whereas I/R induced a slight increase in leukocyte adhesion. After ischemia, capillary perfusion rapidly recovered to about 50% and returned to near normal (90%) after 2 h. HTK at 22 degrees C did not affect the assessed microcirculation variables, whereas HTK at 4 degrees C reduced leukocyte rolling, but not adhesion. Therefore, microvascular function of HTK-perfused muscles was not better preserved during warm I/R than that of nonperfused muscles. Contrary to other preservation solutions, HTK perfusion in itself was not detrimental to the microcirculation.

Effect of hypothermia and HTK on the microcirculation in the rat cremaster muscle after ischaemia.

Hypothermia is an important preservation method for tissues and solid organs. The aim of the present study was to assess in rat cremaster muscle the effect of hypothermia, without or with pre-ischaemic HTK (histidine-tryptophan-ketoglutarate-Bretschneider solution) perfusion, on microvascular consequences of 4 or 6 h ischaemia and 2 h of reperfusion. Intravital microscopy was applied to examine capillary perfusion and leucocyte-endothelium interactions. The cremaster muscle was subjected to 4 or 6 h of cold (4 degrees C) or warm (33-34 degrees C) ischaemia and 2 h of reperfusion. Measurements were performed at baseline, prior to HTK perfusion and ischaemia, and at 0, 1 and 2 h after blood flow restoration. Hypothermia completely prevented the 50% reduction in capillary perfusion that was observed previously at start of reperfusion after 4 h warm ischaemia. After 6 h of warm ischaemia, perfusion resumed in only 45% of capillaries and remained at this low level during reperfusion. In contrast, only a slight decrease (< 10%) in capillary perfusion was observed after 6 h of cold ischaemia. Pre-ischaemic HTK perfusion had no beneficial effect on tissue perfusion. Both hypothermia and HTK attenuated the significant increase in venular leucocyte-vessel wall interactions, which was observed after 4 h of warm ischaemia in a previous study. Combined application of both interventions had no additional effects. After 6 h of warm ischaemia, no increase in leucocyte-vessel wall interactions was observed, possibly due to venular flow reduction. In conclusion, hypothermia preserves capillary perfusion and prevents an increase in leucocyte-vessel wall interactions during reperfusion after muscle tissue ischaemia. Preischaemic perfusion of the vasculature with HTK does not improve the effects of cold storage on tissue perfusion, but attenuates the inflammatory response independently of temperature effect.

Effectiveness of cleaners and sanitizers in killing Salmonella Newport in the gut of a free-living nematode, Caenorhabditis elegans.

Caenorhabditis elegans, a free-living nematode found in soil, has been shown to ingest human enteric pathogens, thereby potentially serving as a vector for preharvest contamination of fruits and vegetables. A study was undertaken to evaluate the efficacy of cleaners and sanitizers in killing Salmonella enterica serotype Newport in the gut of C. elegans. Adult worms were fed nalidixic acid-adapted cells of Escherichia coli OP50 (control) or Salmonella Newport for 24 h, washed, placed on paper discs, and incubated at temperatures of 4 or 20 degrees C and relative humidities of 33 or 98% for 24 h. Two commercial cleaners (Enforce and K Foam Lo) and four sanitizers (2% acetic acid, 2% lactic acid, Sanova, and chlorine [50 and 200 microg/ml]) were applied to worms for 0, 2, or 10 min. Populations of E. coli and Salmonella Newport (CFU per worm) in untreated and treated worms were determined by sonicating worms in 0.1% peptone and surface plating suspensions of released cells on tryptic soy agar containing nalidixic acid. Populations of Salmonella Newport in worms exposed to 33 or 98% relative humidity at 4 degrees or 33% relative humidity at 20 degrees C were significantly (P < or = 0.05) lower than the number surviving exposure to 98% relative humidity at 20 degrees C. In general, treatment of desiccated worms with cleaners and sanitizers was effective in significantly (P < or = 0.05) reducing the number of ingested Salmonella Newport. Results indicate that temperature and relative humidity influence the survival of Salmonella Newport in the gut of C. elegans, and cleaners and sanitizers may not eliminate the pathogen.

Lymphadenectomy prior to rat hind limb allotransplantation prevents graft-versus-host disease in chimeric hosts.

In previous rat studies, the use of mixed allogeneic chimerism (MAC) to induce host tolerance to hind limb allografts has resulted in severe graft-versus-host disease (GVHD). The purpose of this study was to determine if immunocompetent cells in bone marrow (BM) and/or lymph nodes (LNs) of transplanted limbs were responsible for inducing GVHD in mixed chimeric hosts. [ACI-->Wistar Furth] chimeric rats received ACI hind limbs that were non-irradiated, irradiated (1050 cGy) or lymphadenectomized. Rejection, GVHD and donor chimerism was assessed. Chimeric hosts rejected none of their limbs. However, hosts of non-irradiated hind limbs succumbed to GVHD 22.4+/-0.8 days after transplantation. In contrast, chimeras that received irradiated or lymphadenectomized ACI hind limbs showed no clinical or histological signs of GVHD at 5 months. We conclude that mixed chimeric hosts are susceptible to GVHD due to the immunocompetent cell load provided by the LNs, not the BM, of hind limb allografts.

Assessing behavioral toxicity with Caenorhabditis elegans.

Behavior, even in simple metazoans, depends upon integrated processes at the subcellular, cellular, and organismal level, and thus is susceptible to disruption by a broad spectrum of chemicals. Locomotor behavior (movement) of the small free-living nematode Caenorhabditis elegans has proven to be useful in assessing toxicity. Recently reported observations suggest that behavioral change (reduced movement) occurs after 4 h of exposure to heavy metals, and that with abbreviated exposure, the concentration-response relationship for Pb (a known neurotoxic metal) differs from that for Cu. In this study, movement was evaluated after 4-h exposures for nine compounds from three chemical classes: organic pesticides, organic solvents, and heavy metals. Concentration-dependent reduction of movement was observed for all test compounds with the exception of mebendazole, for which test concentrations were limited by solubility. Within each chemical class, movement was more sensitive to the neurotoxic compounds than to substances not believed to be neurotoxic, as evidenced by behavioral effective concentration to reduce average worm movement to 50% of the control movement values (e.g., levamisole and chlorpyrifos < mebendazole, ethanol and acetone < dimethylsulfoxide, and Pb and Al < Cu). These observations are discussed as they relate to the use of acute behavioral tests in assessing general chemical toxicity, and the enhanced value of 4-h testing for the detection of neural toxicants.

The nematode Caenorhabditis elegans as a model of organophosphate-induced mammalian neurotoxicity.

Fifteen organic phosphate pesticides were tested by computer tracking for their acute behavioral toxicity with the nematode Caenorhabditis elegans. Thirteen of these 15 chemicals are used as insecticides and are anticholesterase agents. The other two chemicals are used as herbicides. EC50 values for each chemical were compared to the corresponding LD50 acute lethality value in rats and mice. Order of toxicity was found to be significantly correlated in comparisons of C. elegans to both rats and mice. Mechanistic investigations were conducted by assaying 8 of the 15 chemicals for anticholinesterase activity in C. elegans. Significant cholinesterase inhibition was confirmed for five chemicals that had displayed high behavioral toxicity, while three chemicals of low behavioral toxicity showed no significant decrease in cholinesterase activity. Toxicity for two chemicals that do not inhibit cholinesterase in mammals was linked to pH effects. Detailed comparison of individual chemicals and metabolic issues are discussed. These results have positive implications for the use of C. elegans as a mammalian neurological model and support the use of C. elegans in early rounds of chemical toxicity screening.

Attraction of a free-living nematode, Caenorhabditis elegans, to foodborne pathogenic bacteria and its potential as a vector of Salmonella poona for preharvest contamination of cantaloupe.

Caenorhabditis elegans was studied to determine the potential role of free-living microbivorous nematodes as vectors for preharvest contamination of fruits and vegetables with foodborne pathogens. The propensity of C. elegans to be attracted to seven strains of Escherichia coli O157:H7, eight serotypes of Salmonella, six strains of Listeria monocytogenes, and cantaloupe juice was investigated. Twenty to 30 adult worms were placed on the surface of K agar midway between a 24-h bacterial colony and 10 microl of uninoculated tryptic soy broth (TSB) or cantaloupe juice positioned 1.5 cm apart. The numbers of nematodes that migrated to the colony, to the TSB, and to the cantaloupe juice within 5, 10, 15, and 20 min at 21 degrees C were determined, and then the plates were incubated at 37 degrees C for up to 7 days to determine the ability of C. elegans to survive and reproduce in bacterial colonies. The nematode was attracted to colonies of all test pathogens and survived and reproduced within colonies for up to 7 days. C. elegans was not attracted to cantaloupe juice. The potential of C. elegans to serve as a vector for the transport of Salmonella Poona to cantaloupe rinds was investigated. Adult worms that had been immersed in a suspension of Salmonella Poona were deposited 1 or 3 cm below the surface of soil on which a piece of cantaloupe rind was placed. The rind was analyzed for the presence of Salmonella Poona after 1, 3, 7, and 10 days at 21 degrees C. The presence of Salmonella Poona was evident more quickly on rinds positioned on soil beneath which C. elegans inoculated with Salmonella Poona was initially deposited than on rinds positioned on soil beneath which Salmonella Poona alone was deposited. The time required to detect Salmonella Poona on rinds was longer when the rind was placed 3 cm above the inoculum than when the rind was placed 1 cm above the inoculum. Free-living nematodes may play a role in the preharvest dispersal of incidental human pathogens in soil to the surfaces of raw fruits and vegetables in contact with soil during development and maturation, as evidenced by the behavior of C. elegans as a test model.

Interaction of a free-living soil nematode, Caenorhabditis elegans, with surrogates of foodborne pathogenic bacteria.

Free-living nematodes may harbor, protect, and disperse bacteria, including those ingested and passed in viable form in feces. These nematodes are potential vectors for human pathogens and may play a role in foodborne diseases associated with fruits and vegetables eaten raw. In this study, we evaluated the associations between a free-living soil nematode, Caenorhabditis elegans, and Escherichia coli, an avirulent strain of Salmonella Typhimurium, Listeria welshimeri, and Bacillus cereus. On an agar medium, young adult worms quickly moved toward colonies of all four bacteria; over 90% of 3-day-old adult worms entered colonies within 16 min after inoculation. After 48 h, worms moved in and out of colonies of L. welshimeri and B. cereus but remained associated with E. coli and Salmonella Typhimurium colonies for at least 96 h. Young adult worms fed on cells of the four bacteria suspended in K medium. Worms survived and reproduced with the use of nutrients derived from all test bacteria, as determined for eggs laid by second-generation worms after culturing for 96 h. Development was slightly slower for worms fed gram-positive bacteria than for worms fed gram-negative bacteria. Worms that fed for 24 h on bacterial lawns formed on tryptic soy agar dispersed bacteria over a 3-h period when they were transferred to a bacteria-free agar surface. The results of this study suggest that C. elegans and perhaps other free-living nematodes are potential vectors for both gram-positive and gram-negative bacteria, including foodborne pathogens in soil.

Low-dose immunosuppression in a rat hind-limb transplantation model.

Composite tissue allografts (CTAs) offer an alternative to conventional reconstructive methods. However, the toxicity of the drugs that are required to prevent rejection has prevented its widespread clinical application. The purpose of this study was to determine whether a low-dose, corticosteroid-free combination regimen of tacrolimus and mycophenolate mofetil (MMF) would prevent rejection in a rat hind-limb model, with minimal toxic side effects. Three groups were used in this study. In group I, Wistar Furth (WF) rats received a syngeneic WF hind-limb. In groups II and III, WF rats received an ACI hind-limb. The latter were treated with tacrolimus-MMF. Assessment for rejection, flow cytometry, and mixed lymphocyte reactions was performed. Biopsies were taken regularly and at the time of killing. Combination therapy with low-dose tacrolimus-MMF effectively prolonged CTA survival indefinitely, with minimal side effects. Toxicity associated with immunosuppressive drugs can be avoided in a low-dose combination corticosteroid-free regimen.