Detoxification of ochratoxin A,a food contaminant: Prevention of growth of Aspergillus ochraceus and its production of ochratoxin A

The toxicity of ochratoxin A (OTA), a mycotoxin produced by fungi ofAspergillus orPenicillium genera is now well documented. Its nephrotoxicity, immunosuppression, teratogenicity, and carcinogenicity have been widely studied. Physical and biochemical methods have been studied to prevent these toxinogenicAspergillus andPenicillium from producing OTA, and/or to destroy the mycotoxin when already produced in a liquid or a solid medium. Repeated freezing at ? 20?C and thawing at + 26?C aleatory reduce OTA production in a liquid medium. Exposure to UV B for different periods of time is efficient in preventing OTA production in a liquid medium. Gamma-irradiation from 2 to 5 kGy gives good results in preventing the production of OTA or destroying it when already produced. Carboxypeptidase is very efficient at 5 units/50 ml in a liquid medium for cleaving the OTA already produced.     

Cerebral energy metabolism during the onset and recovery from halothane anesthesia

Halothane (1%) was administered to twenty-two gram female Swiss-Albino mice which were sacrificed at times of 15 seconds, 45 seconds, 79 seconds and 5 minutes. Additional animals were exposed for 5 minutes and sacrificed 10 minutes after removal from halothane (recovery). Selected energy metabolites were measured in 100–500 nanogram samples from the inferior colliculus and the ascending reticular activating system.Results from this study showed an increase in glucose levels at 79 seconds, when the animals first lost their righting response. The glucose increase was similar in the inferior colliculus and reticular formation. ATP and phosphocreatine were increased at 45 seconds, and during the sleep period in the ascending reticular activiting system, and returned to normal during the recovery period. In the inferior colliculus, ATP was similarly increased from 45 seconds throughout the time course, whereas phosphocreatine was elevated at 79 seconds, and during recovery only. These data suggest a decrease in utilization of energy metabolities during halothane anesthesia, both in cells of the inferior colliculus and ascending reticular activating system.     

Metabolic profile of hippocampal regions after bilateral ischemia and recovery

Microanalysis methods were used to determine the effect of bilateral carotid occlusion on net levels of energy metabolites in discrete cellular regions of the hippocampus and dentate gyrus of the Mongolian gerbil. Glucose, glycogen, ATP and phosphocreatine levels were not decreased after one minute of bilateral occlusion. Three minutes of ischemia, however, produced a dramatic fall in net levels with no further decrease observed at fifteen minutes. Re-establishment of blood flow for five minutes after a fifteen minute ischemic episode resulted in replenishment of metabolites to pre-ischemic levels. Glucose was increased two to three times in sham-operated animals as compared to control (non-operated) animals. The increase was the result of the Na-pentobarbital anesthetic employed. The present data indicate that regions of the hippocampus and dentate gyrus respond in a uniform manner to bilateral occlusion of the carotid arteries. Further, most cells maintained enough viability to resume production of high-energy phosphate and carbohydrate metabolites.     

Glycolytic metabolism in cultured cells of the nervous system IV. The effects of thiamine deficiency on thiamine levels,metabolites and thiamine-dependent enzymes of the C-6 glioma and C-1300 neuroblastoma cell lines.

Summary C-6 glioma and C-1300 neuroblastoma cells were cultured in thiamine deficient and control media. Thiamine levels, transketolase and pyruvate decarboxylase activities, and high energy phosphate metabolites were all measured in deficient and control cells. Thiamine levels in the deficient cells were found to be below the level of detectability. Pyruvate decarboxylase activity was more susceptible to thiamine deficiency in both cell lines than transketolase. In spite of the large decrease in pyruvate decarboxylase activity, high energy phosphate metabolites were not decreased in either cell line. These data indicate that C-6 glioma and C-1300 neuroblastoma cells have the capacity to maintain normal energy metabolites in the presence of large changes in thiamine levels and thiamine dependent enzyme activity.Supported in part by USPHS grant AA 01391.     

Persistence of Swidden Cultivation in the Face of Globalization: A Case Study from Communities in Calakmul, Mexico

Over the last decades, political, economic and environmental pressures have encouraged changes from swidden to more intensive agricultural practices, resulting in the hypothesis that swidden cultivation systems are disappearing. In Calakmul, southeastern Mexico, communities decreased the area under milpa, the traditional maize swidden system, but a collapse did not occur. To document and explain the persistence of swidden we employ a variety of data: (1) 59 standardized household surveys from 2003 and 2010 in five villages, (2) in-depth interviews in one village, and (3) coupled human–environmental timelines in this same village. Droughts, hurricanes, and remittances were important drivers of decreases in milpa cultivation. Market crop profitability and conservation programs were also reported to affect the area under milpa. Off-farm employment and governmental transfers have tended to stabilize household economies and decrease dependency on agricultural production, but have also allowed households to maintain their milpas for subsistence and cultural reproduction. Findings in Calakmul point to the need to consider swidden as an evolving and active response to changing policy, economic, and environmental conditions.     

The role of fish-poultry integration on fish growth performance,yields and economic benefits among smallholder farmers in sub-Saharan Africa,Tanzania

Aquaculture practices from sub-Saharan Africa are characterised by low production, owing to improper technology. Production can be increased through integrating fish farming with other existing on-farm activities, particularly livestock husbandry. We assessed the role of fish-poultry integration on all male Nile tilapia, Oreochromis niloticus growth performance, yields and economic benefits among smallholder farmers in sub-Saharan Africa, Tanzania. The study also compared phytoplankton species composition, abundance and biomass between the fish-poultry integration and non-integrated system. After 180 days of the experiment, all male O. niloticus cultured under fish-poultry integration exhibited significantly higher growth rates than those in the non-integrated system (p < 0.05). Gross fish yield (GFY), net fish yield (NFY) and net annual yields (NAY) obtained from fish-poultry integration were significantly higher than those from non-integrated system (p < 0.05). Partial enterprise budget analysis revealed that fish-poultry integration was more profitable than the non-integrated system. Moreover, fish-poultry integrated system produced significantly higher phytoplankton abundance and biomass than those from the non-integrated system. Results demonstrate that rural smallholder farmers can achieve higher growth rate, farm net yields and income by integrating all male O. niloticus with other on-farm activities than practising a stand-alone fish culture system.     

Responses in Primary Astrocytes and C6-Glioma Cells to Ammonium Chloride and Dibutyryl Cyclic-AMP

Elevated brain ammonia levels are a major factor in the genesis of hepatic encephalopathy (HE). The mechanism of ammonium chloride (NH₄Cl) neurotoxicity involves interruption of oxidative metabolism. This leads to decreased levels of ATP concentration and subsequent glial fibrillary acidic protein (GFAP) degradation of astrocytes and fibrous C6-glioma cells. Our study investigates NH₄Cl toxicity by evaluating changes in ATP concentration and mitochondrial function as well as by evaluating alterations in GFAP expression. NH₄Cl induced decreases in ATP were detected after 15 minutes in C6-glioma cells and 24 hours in both cell types. Mitochondrial function, assessed by MTT (2–4,5-dimethylthiazol A-yl)-2, 5-diphenyltetrazolium bromide) assay, was impaired in both cell types at 24 hours following NH₄Cl treatment. GFAP was also significantly decreased in both cell types. Morphologic and metabolic toxicities were greater in C6-glioma cells. The data clearly indicate that NH₄Cl interrupts oxidative metabolism. The greater toxicity seen in C6-glioma cells may be due to their greater dependence on oxidative metabolism. Lastly, the decrease in GFAP is probably a consequence of diminished ATP.     

Nuclear gene trees and the phylogenetic relationships of the mangabeys (Primates: Papionini)

Phylogenetic relationships of mangabeys within the Old World monkey tribe Papionini are inferred from analyses of nuclear DNA sequences from five unlinked loci. The following conclusions are strongly supported, based on congruence among trees derived for the five separate gene regions: (1) mangabeys are polyphyletic within the Papionini; (2) Cercocebus is the sister taxon to the genus Mandrillus; and (3) Lophocebus belongs to a clade with Papio and Theropithecus, with Papio as its most likely sister taxon. Morphologically based phylogenies positing mangabey monophyly were evaluated by mapping the sequences for each locus on these trees. The data seem to fit these trees poorly in both maximum-parsimony and likelihood analyses. Incongruence among nuclear gene trees occurred in the interrelationships among Lophocebus, Papio, and Theropithecus. Several factors that may account for this incongruence are discussed, including sampling error, random lineage sorting, and introgression.      

The burden of genetic disease on inpatient care in a children's hospital

The important role of genetics in pediatric illness has been increasingly recognized, but the true impact has not been well delineated. An important study of pediatric inpatient admissions to a children's hospital in 1978 found a genetic basis for disease in just less than half of admitted patients. We sought to update this study in light of current hospitalization practices and new knowledge about genetics. We systematically reviewed the records of 5,747 consecutive admissions (4,224 individuals), representing 98% of patients admitted in 1996 to Rainbow Babies and Children's Hospital (Cleveland, OH). Each patient was assigned to one of five groups on the basis of the presence or absence of an underlying chronic medical condition and whether that condition had a genetic basis or susceptibility. An underlying disorder with a significant genetic component was found in 71% of admitted children. The vast majority (96%) of underlying chronic disorders in children in this study were either clearly genetic or had a genetic susceptibility. Total charges for 1996 were >$62 million, of which $50 million (81%) was accounted for by disorders with a genetic determinant. The 34% of admissions with clearly genetic underlying disorders accounted for 50% (>$31 million) of the total hospital charges. The mean length of stay was 40% longer for individuals with an underlying disease with a genetic basis than for those with no underlying disease. Charges and length of stay were similar for children with underlying chronic disorders, regardless of the cause. This study begins to quantify the enormous impact of genetic disease on inpatient pediatrics and the health care system. Additional study and frank public discourse are needed to understand the implications on the future health care workforce and on the utilization of health care resources.     

CXCL12 limits inflammation by localizing mononuclear infiltrates to the perivascular space during experimental autoimmune encephalomyelitis

The inflammatory response in the CNS begins with the movement of leukocytes across the blood-brain barrier in a multistep process that requires cells to pass through a perivascular space before entering the parenchyma. The molecular mechanisms that orchestrate this movement are not known. The chemokine CXCL12 is highly expressed throughout the CNS by microendothelial cells under normal conditions, suggesting it might play a role maintaining the blood-brain barrier. We tested this hypothesis in the setting of experimental autoimmune encephalomyelitis (EAE) by using AMD3100, a specific antagonist of the CXCL12 receptor CXCR4. We demonstrate that the loss of CXCR4 activation enhances the migration of infiltrating leukocytes into the CNS parenchyma. CXCL12 is expressed at the basolateral surface of CNS endothelial cells in normal spinal cord and at the onset of EAE. This polarity is lost in vessels associated with an extensive parenchymal invasion of mononuclear cells during the peak of disease. Inhibition of CXCR4 activation during the induction of EAE leads to loss of the typical intense perivascular cuffs, which are replaced with widespread white matter infiltration of mononuclear cells, worsening the clinical severity of the disease and increasing inflammation. Taken together, these data suggest a novel anti-inflammatory role for CXCL12 during EAE in that it functions to localize CXCR4-expressing mononuclear cells to the perivascular space, thereby limiting the parenchymal infiltration of autoreactive effector cells.