Action of sorbic acid on Staphylococcus metabolism: a microcalorimetric investigation.

Effect of sorbic acid, an antimicrobial food preservative, on the cellular metabolism of Staphylococcus aureus was observed microcalorimetrically. The highly reproducible and characteristic thermograms of the microorganism were affected significantly by the preservative in a concentration dependent manner. Both the peak heat and total heat dissipation profiles were affected by 50% at the maximum permitted concentration (0.2%) for use in foods.     

Differences in the altered energy metabolism of hemorrhagic shock and hypoxemia.

The effect of hemorrhagic shock, hypoxemia, and anoxia on the levels of adenine and pyridine nucleotides of liver and kidney was assessed. ATP levels in liver and kidney of animals in shock or animals subjected to 7 min of anoxia decreased by 85 and 73%, respectively. Under hypoxic conditions (arterial PO2 AT 18 MMHg), the decrease was only 62 and 48% in liver and kidney, respectively. Tissue NAD levels decreased and NADH levels increased during shock but were found to be essentially unaltered during experimental hypoxemia. Thus, shock produced greater alterations in adenine and pyridine nucleotides than did hypoxemia alone, indicating that stagnant hypoxemia due to shock is more deleterious to energy metabolism than is severe hypoxemia with an otherwise normal circulation. The results also suggest that if an anterial PO2 OF 18 MMHg represents the initial stages of tissue hypoxia, then tissue ATP levels are a more sensitive indicator of this than NAD levels.     

Therapeutic effects of Typha elephantina leave’s extract against paracetamol induced renal injury in rabbits

Present study focuses on ameliorative potential of Typha elephantina leave’s aqueous (TE.AQ) extract against Paracetamol (PCM) induced toxicity in rabbits. We fed the male rabbits with 300 mg PCM in alone and in combination with TE.AQ at different doses i.e. (100, 200 and 300 mg/kg body weight) or silymarin (100 mg/kg) daily for 21 days. PCM in alone significantly (P < 0.5) increased serum urea, uric acid, creatinine, total protein, albumin, globulin and blood urea nitrogen. Serum sodium, potassium and magnesium level were high. The glutathione, radical scavenging activity and Thiobarbituric acid reactive substances were significantly reduced. Treatment with TE.AQ at dose rate 300 mg/kg body weight and Silymarin significantly ameliorated all the parameters when compared with PCM administered group. The 100 and 200 mg of TE.AQ showed no significant effects. The histopathological examination confirmed the therapeutic potential of TE.AQ. These results established the presence of natural antioxidants in Typha elephantina leaves.     

Hypoglycemic and hepatoprotective activity of Rosmarinus officinalis extract in diabetic rats

The present study examined the effect of water extract (200 mg/kg body weight) of Rosmarinus officinalis L. in streptozotocin (STZ)-induced diabetic rats for 21 days. The hepatoprotective effects were investigated in the liver tissues sections. There was a significant increase in serum liver biochemical parameters (aspartate aminotransferase, alanine transaminase, and alkaline phosphatase), accompanied by a significant decrease in the level of total protein and albumin in the STZ-induced rats when compared with that of the normal group. The high-dose treatment group (200 mg/kg body wt) significantly restored the elevated liver function enzymes near to normal. This study revealed that rosemary extracts exerted a hepatoprotective effect. The results indicate that the extract exhibits the protective effect on tissues and prove its potentials as an antidiabetic agent.     

Transorbital Sonographic Evaluation of Normal Optic Nerve Sheath Diameter in Healthy Volunteers in Bangladesh

Introduction

Measurement of optic nerve sheath diameter (ONSD) by ultrasound is increasingly used as a marker to detect raised intracranial pressure (ICP). ONSD varies with age and there is no clear consensus between studies for an upper limit of normal. Knowledge of normal ONSD in a healthy population is essential to interpret this measurement.

Methods

In a prospective observational study, ONSD was measured using a 15 MHz ultrasound probe in healthy volunteers in Chittagong, Bangladesh. The aims were to determine the normal range of ONSD in healthy Bangladeshi adults and children, compare measurements in males and females, horizontal and vertical beam orientations and left and right eyes in the same individual and to determine whether ONSD varies with head circumference independent of age.

Results

136 subjects were enrolled, 12.5% of whom were age 16 or under. Median ONSD was 4.41 mm with 95% of subjects in the range 4.25–4.75 mm. ONSD was bimodally distributed. There was no relationship between ONSD and age (≥4 years), gender, head circumference, and no difference in left vs right eye or horizontal vs vertical beam.

Conclusions

Ultrasonographic ONSD in Bangladeshi healthy volunteers has a narrow bimodal distribution independent of age (≥4 years), gender and head circumference. ONSD >4.75 mm in this population should be considered abnormal.     

Fatty Acids Induce Chloride Permeation in Rat Liver Mitochondria by Activation of the Inner Membrane Anion Channel (IMAC)

The inner membrane of freshly isolated mammalian mitochondria is poorly permeable to Cl(-). Low, nonlytic concentrations (< or =30 microM) of long-chain fatty acids or their branched-chain derivatives increase permeation of Cl(-) as indicated from rapid large-scale swelling of mitochondria suspended in slightly alkaline KCl medium (supplemented with valinomycin). Myristic, palmitic, or 5-doxylstearic acid are powerful inducers of Cl(-) permeation, whereas lauric, phytanic, stearic, or 16-doxylstearic acid stimulate Cl(-) permeation in a lesser extent. Fatty acid-induced Cl(-) permeation across the inner membrane correlates well with the property of nonesterified fatty acids to release endogenous Mg(2+) from mitochondria. Myristic acid stimulates anion permeation in a selective manner, similar as was described for A23187, an activator of the inner membrane anion channel (IMAC). Myristic acid-induced Cl(-) permeation is blocked by low concentrations of tributyltin chloride (IC(50) approximately 1.5 nmol/mg protein). Moreover, myristic acid activates a transmembrane ion current in patch-clamped mitoplasts (mitochondria with the outer membrane removed) exposed to alkaline KCl medium. This current is best ascribed to the opening of an ion channel with a single-channel conductance of 108 pS. We propose that long-chain fatty acids can activate IMAC by withdrawal of Mg(2+) from intrinsic binding sites.     

An ontology for collaborative construction and analysis of cellular pathways

MOTIVATION: As the scientific curiosity in genome studies shifts toward identification of functions of the genomes in large scale, data produced about cellular processes at molecular level has been accumulating with an accelerating rate. In this regard, it is essential to be able to store, integrate, access and analyze this data effectively with the help of software tools. Clearly this requires a strong ontology that is intuitive, comprehensive and uncomplicated. RESULTS: We define an ontology for an intuitive, comprehensive and uncomplicated representation of cellular events. The ontology presented here enables integration of fragmented or incomplete pathway information via collaboration, and supports manipulation of the stored data. In addition, it facilitates concurrent modifications to the data while maintaining its validity and consistency. Furthermore, novel structures for representation of multiple levels of abstraction for pathways and homologies is provided. Lastly, our ontology supports efficient querying of large amounts of data. We have also developed a software tool named pathway analysis tool for integration and knowledge acquisition (PATIKA) providing an integrated, multi-user environment for visualizing and manipulating network of cellular events. PATIKA implements the basics of our ontology.     

Lyn- and ERK-mediated vs. Ca2+-mediated neutrophil O2- responses with thermal injury

We evaluated thedependency of neutrophil O production on PTK-Lyn andMAPK-ERK1/2 in rats after thermal injury. Activation of PTK-Lyn wasassessed by immunoprecipitation. Phosphorylation of ERK1/2 was assessedby Western blot analysis. O production was measuredby isoluminol-enhanced luminometry. Imaging technique was employed tomeasure neutrophil [Ca²⁺]_i in individualcells. Thermal injury caused marked upregulation of Lyn and ERK1/2accompanying enhanced neutrophil O production.Treatment of rats with PTK blocker (AG556) or MAPK blocker (AG1478)before burn injury caused complete inhibition of the respective kinaseactivation. Both AG556 and AG1478 produced an ~66% inhibition inO production. Treatment with diltiazem (DZ) producedan ~37% inhibition of O production withoutaffecting Lyn or ERK1/2 activation with burn injury. Ca²⁺mobilization was upregulated with burn injury but not affected bytreatment of burn rats with AG556. Unlike the partial inhibition ofburn-induced O production by AG556, AG1478, or DZ,platelet-activating factor antagonist (PAFa) treatment of burn ratsproduced near complete inhibition of O production.PAFa treatment also blocked activation of Lyn. The findings suggestthat the near complete inhibition of O production byPAFa was a result of blockade of PTK as well as Ca²⁺signaling. Overall, our studies show that enhanced neutrophil O production after thermal injury is a result ofpotentiation of Ca²⁺-linked and -independent signalingtriggered by inflammatory agents such as PAF.

     

Gut-associated lymphoid T cell suppression enhances bacterial translocation in alcohol and burn injury

The mechanism of alcohol-mediated increased infection in burn patients remains unknown. With the use of a rat model of acute alcohol and burn injury, the present study ascertained whether acute alcohol exposure before thermal injury enhances gut bacterial translocation. On day 2 postinjury, we found a severalfold increase in gut bacterial translocation in rats receiving both alcohol and burn injury compared with the animals receiving either injury alone. Whereas there were no demonstrable changes in intestinal morphology in any group of animals, a significant increase in intestinal permeability was observed in ethanol- and burn-injured rats compared with the rats receiving either injury alone. We further examined the role of intestinal immune defense by determining the gut-associated lymphoid (Peyer's patches and mesenteric lymph nodes) T cell effector responses 2 days after alcohol and burn injury. Although there was a decrease in the proliferation and interferon-gamma by gut lymphoid T cells after burn injury alone; the suppression was maximum in the group of rats receiving both alcohol and burn injuries. Furthermore, the depletion of CD3(+) cells in healthy rats resulted in bacterial accumulation in mesenteric lymph nodes; such CD3(+) cell depletion in alcohol- and burn-injured rats furthered the spread of bacteria to spleen and circulation. In conclusion, our data suggest that the increased intestinal permeability and a suppression of intestinal immune defense in rats receiving alcohol and burn injury may cause an increase in bacterial translocation and their spread to extraintestinal sites.