Host factors that influence the behaviour of bacterial pathogens in vivo

Interest is increasing in how bacteria behave and produce virulence determinants within the infected host. There are three aspects of this process; observations on the bacteria themselves, recognition of host factors that affect them and investigation of metabolic interactions between the two. The first aspect is relatively easy to investigate and attracts much interest. The second and third are difficult to work on and hence understudied. The review aims to stimulate interest in them by indicating methods of investigation and describing some successful studies. After discussing host factors that determine growth in vivo consideration is given to factors that influence the production of the determinants of mucosal colonization, penetration, interference with host defence and damage to the host. The final section deals with the influence of host-derived cytidine 5'-monophospho-N-acetyl neuraminic acid and lactate on the pathogenicity of gonococci, meningococci and Haemophilus influenzae.     

乳酸左氧氟沙星注射液与替硝唑注射液配伍稳定性考察

目的考察乳酸左氧氟沙星注射液与替硝唑注射液配伍的稳定性。方法考察室温（20℃）下8h内乳酸左氧氟沙星（2g／L）与替硝唑（4g／L）配伍液的外观、pH值变化，用高效液相色谱法测定两种药物的含量。结果两种药物配伍后8h内的含量、pH值及外观均无明显变化。结论乳酸左氧氟沙星注射液与替硝唑注射液可以配伍。     

Effects of pH on the glucose and lactate metabolisms by the washed cells of Actinomyces naeslundii under anaerobic and aerobic conditions

Effects of pH on the glucose and lactate metabolism by the washed cells of Actinomyces naeslundii genospecies 1 and 2 under anaerobic and aerobic conditions were studied. The rate of acid production from glucose was the highest at pH 7.0 and decreased as the pH lowered to 4.5, irrespective of atmospheric conditions. The anaerobic end-product in the absence of bicarbonate was mainly lactate, while in the presence of bicarbonate the rate of acid production increased 1.8-2.5 times with the production of formate, acetate and succinate in addition to lactate. Under aerobic conditions, the cells produced acids from glucose along with oxygen consumption and the end-product was mainly acetate. In contrast to the glucose metabilism, the cells produced base from lactate along with oxygen consumption. The rates of base production and oxygen consumption were the highest at pH 5.5. The end-products from lactate were acetate and pyruvate. These results indicate that oral actinomyces has a various activity of glucose and lactate metabolism at a wide range of environmental pH and suggest its flexibility in surviving in dental plaque, where the environmental factors fluctuate.     

METABOLIC AND ENDOCRINE RESPONSES TO A MILK FEED IN SIX-DAY-OLD TERM INFANTS: DIFFERENCES BETWEEN BREAST AND COW'S MILK FORMULA FEEDING

ABSTRACT. Lucas, A., Boyes, S., Aynsley-Green, A. (Department of Paediatrics, John Radcliffe Hospital, Oxford) and Bloom, S. R. (Hammersmith Hospital, London, England). Metabolic and endocrine responses to a milk feed in six-day-old term infants: JMfferences between breast and cow's milk formula feeding. Acta Paediatr Scand, 70:195, 1981. – There is little information on the metabolic and endocrine responses to milk feeding in the neonatal period particularly in relation to the mode of nutrition and composition of the milk. Plasma concentrations of insulin, glucagon and gastric inhibitory polypeptide (GIP) together with blood levels of glucose, ketone bodies, pyruvate, lactate and glycerol were measured pre- and post-prandially in 79 healthy six-day-old term infants who had been either breast fed or fed on a modified cow's milk formula (Cow and Gate Premium) from birth. Formula fed infants had a greater insulin and GIP response to feeding and their basal and postprandial blood ketones were considerably lower than in breast fed infants. In addition a significantly greater post feed rise in both lactate and pyruvate concentrations was observed with formula feeding. These results may have significant implications regarding infant feeding and postnatal metabolism.     

Adrenergic innervation of the gingiva in experimental periodontitis

In experiments on guinea pigs, the nerve-tissue relationships in gingival papillae were studied under conditions of experimental inflammation induced by local (turpentine injection) and general (whole-body γ-irradiation). It is found that structural and metabolic changes in the lamina propria and epithelium of the gingival mucosa correlate with disturbances in trophic influences from the sympathetic nervous system. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 127, No. 5, pp. 564–568, May, 1999     

Extracorporeal determination of glucose, lactate and potassium with electrochemical biosensors

Glucose, lactate and potassium ions have been continuously measured in whole blood by using two extracorporeal electrochemical biosensors and a new flow through potassium electrode. For experiments involving the “glucose clamp”, lactate and potassium electrodes have been connected in series to an endocrine artificial pancreas “Betalike” properly modified. The same artificial pancreas has been used in experiments measuring the anaerobic threshold (AT) by continuous monitoring of lactate in athletes. In this case glucose and lactate sensors were connected in series for continuous measurement of both metabolites in blood in real time. The results are in agreement with the biochemical pathways involving such metabolises.     

血清镁离子酶法测定及在肝硬化病人中的应用

目的　评价丙酮酸激酶偶联乳酸脱氢酶测定血清镁离子方法 ,观察几种物质对镁测定的干扰及肝硬化病人血清镁离子水平。方法　应用丙酮酸激酶偶联乳酸脱氢酶反应测定血清镁离子。结果　该方法批内CV为 0 .63 % ,日间CV为 1.46% ,钾、氨、钙、锰、铜、锌、铁离子以及胆红素、甘油三酯和血红蛋白对镁离子测定无干扰。肝硬化组病人血清镁为 (0 .67± 0 .14 )mmol L ,对照组为 (0 .88± 0 .0 9)mmol L ,t =8.5 71,P <0 .0 1,两组差别具有显著的统计学意义。结论　该方法准确性好 ,灵敏度高 ,特异性强 ,抗干扰性强。低血镁 (2 1 3 3 ,63 .64 % )在肝硬化中较为常见     

Plasma Potassium and Phosphate Concentrations—Influence by Adrenaline Infusion, β-blockade and Physical Exercise

ABSTRACT. Ljunghall S, Joborn H, Rastad J, Åkerström G (Departments of Internal Medicine, and Surgery, University Hospital, Uppsala, Sweden). Plasma potassium and phosphate concentrations—influence by adrenaline infusion, β-blockade and physical exercise. Acta Med Scand 1987; 221:83–93. Infusion of adrenaline into healthy male subjects reduced the plasma concentrations of both potassium and phosphate to a similar extent, in a dose-dependent manner, an effect which was prevented by the administration of propranolol. Ergometer bicycling until exhaustion, which caused marked accumulation of lactic acid in the blood and reduction of pH, induced great elevations of both plasma potassium and phosphate with close relationships between the raised plasma concentrations and the reduction in pH, also during β-blockade. However, longer-term aerobic exercise, without acidosis, also caused some rise of the potassium and phosphate concentrations. During recovery from anaerobic, but not from aerobic, exercise there was a rapid decrease of the plasma potassium levels while the phosphate values normalized gradually together with pH. From measurements of the ion concentrations both in the femoral effluent of one leg, which carried out maximal isokinetic work, and in the opposite antecubital vein it could be calculated that there was for potassium, but not for phosphate, a post-exercise uptake both in the exercised muscle and in the entire organism, indicating the participation of systemic factors.     

Accelerated utilization of lactate under the effect of hypoxen after intensive exercise

Administration of substrates of energy metabolism in combination with hypoxen (sulfur-containing oligoquinone) promoted the increase in blood lactate concentration during maximum exercise, accelerated lactate utilization, and reduced the lactate/pyruvate ratio during recovery. The in vivo effects are in line with hypoxen capacity to accelerate in vitro oxidation of exogenous NADH in mitochondria by the non-rotenone-dependent pathway realized with participation of cytochrome C. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 145, No. 2, pp. 158–161, February, 2008