Current trends in ß-lactam based ß-lactamases inhibitors.

The introduction of antibiotics to treat bacterial infections either by killing or blocking their growth has been accompanied by the development of resistance mechanism that allows the bacteria to survive and proliferate. In particular the successive series of ß-lactams have selected several generations of ß-lactamases including ESBLs, AmpC ß-lactamases, KPC carbapenamases in Enterobacteriaceae, the metallo ß-lactamases VIMs and IMPs, and very recently the threatening NDM-1 that confers resistance to virtually any clinically used antibiotic. The increasing use of carbapenems due to the spread of resistance to other existing antibacterial agents has facilitated the spread of resistance, especially in Acinetobacter spp. due to OXA- and metallo-carbapenemases. The pharmaceutical industry, that abandoned this field at the end of the nineties, is now trying to recover by developing some novel ß-lactam antibiotics and novel ß-lactamase-inhibitors, the latter to be used in combination with new as well as seasoned ß-lactam antibiotics. This article provides a survey of patent and scientific literature for ß-lactamase inhibitors discovered in the period 2006-2010.

Some characteristics of nutrition metabolism and hormone control during the first 24 hours in neonatal calves.

Six male Holstein calves of spontaneous delivery and with jugular vein catheter were chosen to study the characteristics of nutrition metabolism and hormone control during the first 24 h of age after birth. The results showed that plasma fructose (Fru) and lactic acid (LA) concentrations were highest at birth, fell significantly during the first 2 h of life, and then dropped further until 24 h. Glucose (Glu) increased at 0.5 h after birth, followed by a gradual decrease until 8 h, with a general upward trend thereafter. Free fatty acid (FFA) was very low at birth, rose rapidly within 2 h of live, and kept a relatively high concentration thereafter. Total protein (TP) had not obvious change and fluctuated at a low level during the first 24 h of age. The rise of insulin (Ins) at 1 h of age was observed, with a downward tendency thereafter. Plasma cortisol (Cort) level was high during 1 h of age and tend to drop thereafter. An obviously rising tendency of T4 and T3 was found during the first 4 h of life, followed by their keeping relatively high levels although decreasing constantly in neonatal calves.

Characteristics and developmental changes of some plasma nutrition metabolites in neonatal lambs.

Twelve spontaneously delivered Hu sheep neonatal lambs with a birth weight of 1.5-4.5 kg were used to study the characteristics and developmental changes of plasma nutrition metabolites during postnatal period in 7 days of age. The results showed that plasma glucose (Glu) concentration rose significantly within 4 h after lambing and then maintained a fluctuent upward tendency until day 7 of age. Fructose (Fru) and lactic acid (LA) concentrations were highest at 1 h after birth, tended to drop thereafter, and remained relatively stable levels after day 3 of age. Free fatty acid (FFA) tended to increase within 12 h after birth, followed by keeping comparatively high levels although decreasing fluctuently. An obvious increase of total protein (TP) occurred within 8 h after birth and then remained a relatively high concentration until day 7 of age. a-Amino nitrogen (a-NH2N) tended to rise by 4 h and fell slightly thereafter, urea nitrogen (UN) had an elevated concentration from birth to 8 h and then dropped obviously. Both a-NH2N and UN appeared to be fairly stable during the first week of age in neonatal lambs.

The development changes and correlations of some blood hormone levels and immune indexes during the postnatal period in neonatal calves.

The developmental changes and correlations of some hormone levels and immune parameters in six spontaneously delivered Holstein calves with a birth weight of 40-50 kg were studied for a postnatal period of 1-15 days after birth. The mean levels of insulin (I), glucagon (Gc), cortisol (C) and growth hormone (GH) before feeding on day 1 were 9.68 +/- 3.27 muu/ml, 685.39 +/- 95.42 pg/ml, 14.27 +/- 5.58 micrograms/dl and 0.85 +/- 0.10 ng/ml respectively. I and GH increased on day 2 and then decreased to a steady level. Gc and C fell fluctuantly within week 1 and remained at a stable level after then. WBC, neutrophil percentage, B-lymphocyte percentage, albumin percentage decreased with day of age in 1st week and lymphocyte percentage, T-lymphocyte percentage, T-G (total globulin) percentage and gamma-G percentage increased with day of age in 1st week and then reached a steady level. The correlations between some hormone levels and immune parameters indicated that C and Gc have significantly negative correlations with gamma-G (%), T-G (%) and T-lymphocyte (%) respectively. WBC is positively correlated to C and Gc significantly. The correlations of I and GH with some immune parameters have no significance.