To explore the effects of intrauterine infection on early growth and neurobehavioral development in neonatal rats. (E. coli) was inoculated into uterine cervix of pregnant rats with gestation of 15 d to establish the intrauterine infection model, and the effect on the delivery of pregnant rats was observed. The neonatal rat brain tissue was stained with Hematoxylin-Eosin and the cerebral white matter damage was assessed. Immunohistochemical staining and Western blot analysis were performed to evaluate the expression of glial fibrillary acidic protein (GFAP), 2', 3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) and neurofilament (NF) in pup brains. Birth weight and early growth development indices were monitored,and neurobehavioral tests were performed to access the change of neurobehavioral development in neonatal rats. The white blood cell count increased significantly in the uterus and placenta of the pregnant rats after intrauterine E. coli infection and no significant impact was observed on the delivery of pregnant rats. Weak staining and focal rarefaction of cerebral white matter from rats at P7 in intrauterine infection group were observed. The expression of GFAP markedly increased (<0.05) in infection group, while the level of CNPase and NF in pup brains at P7 significantly decreased (<0.05 or <0.01). Compared with control group, the neonatal rats in infection group had lower birth weight and slower weight gain during the suckling period (<0.05 or <0.01), and the completion times of ear opening, eye opening, surface righting, negative geotaxis, acoustic startle and swimming test in infection group were significantly delayed (<0.05 or <0.01). Intrauterine infection in pregnant rats can induce cerebral white matter damage and retardation of early growth and neurobehavioral development in neonatal rats.
Animals ; Animals, Newborn ; Behavior, Animal ; Body Weight ; Disease Models, Animal ; Escherichia coli ; Escherichia coli Infections ; complications ; physiopathology ; Female ; Glial Fibrillary Acidic Protein ; genetics ; Growth Disorders ; etiology ; Leukoencephalopathies ; etiology ; Pregnancy ; Pregnancy Complications, Infectious ; physiopathology ; Rats ; Rats, Sprague-Dawley

This study examined the effect of experimentally induced fever on the pharmacokinetics of cefepime (75 mg/kg BW) administered intramuscularly to six rabbits. The study was carried out in two consecutive phases separated by a two-week washout period. An infection was induced by an intravenous inoculation of 5 x 10(8) colony-forming units of Escherichia coli 24 h before the pharmacokinetic investigation. A quantitative microbiological assay was employed to measure the plasma cefepime concentrations using an agar-gel diffusion method with Bacillus subtilis ATCC 6633 as the test organism. Twenty-four hour after the injection, the rectal temperature in the infected animals increased by 1degrees C. There was a significant reduction in the elimination halflife by 21.8% in the febrile rabbits compared to healthy animals. In addition, the infection significantly increased the peak plasma concentrations by 11.9%, the mean residence time by 19.9%, the area under the plasmaconcentration- time curve by 53.6% and the area under the moment curve by 62.3%. In conclusion, the endotoxin-induced febrile state produced significant changes in the plasma levels as well as some of the pharmacokinetic variables of cefepime in rabbits.
Animals ; Anti-Bacterial Agents/*administration&dosage/blood/*pharmacokinetics ; Area Under Curve ; Cephalosporins/*administration&dosage/blood/*pharmacokinetics ; Endotoxins/pharmacology ; Escherichia coli Infections/drug therapy/physiopathology ; Fever/chemically induced/*physiopathology ; Half-Life ; Injections, Intramuscular ; Male ; Rabbits

In this study, we tested the hypothesis that decreased cerebral perfusion pressure (CPP) induces cerebral ischemia and worsen brain damage in neonatal bacterial meningitis. Meningitis was induced by intracisternal injection of 10(9) colony forming units of Escherichia coli in 21 newborn piglets. Although CPP decreased significantly at 8 hr after bacterial inoculation, deduced hemoglobin (HbD), measured as an index of changes in cerebral blood flow by near infrared spectroscopy, did not decrease significantly. In correlation analyses, CPP showed significant positive correlation with brain ATP and inverse correlation with brain lactate levels. CPP also correlated positively with HbD and oxidized cytochrome aa3 (Cyt aa3) by near infrared spectroscopy. However, CPP did not show significant correlation with cerebral cortical cell membrane Na+,K+-ATPase activity, nor with levels of lipid peroxidation products. In summary, decreased CPP observed in this study failed to induce cerebral ischemia and further brain injury, indicating that cerebrovascular autoregulation is intact during the early phase of experimental neonatal bacterial meningitis.
Animal ; Animals, Newborn ; Blood Glucose/metabolism ; Cell Membrane/microbiology ; Cell Membrane/enzymology ; Cerebral Cortex/metabolism ; Cerebral Cortex/chemistry ; Cerebral Cortex/blood supply ; Cerebrovascular Circulation/physiology* ; Energy Metabolism/physiology* ; Escherichia coli Infections/physiopathology* ; Escherichia coli Infections/metabolism* ; Glucose/cerebrospinal fluid ; Glucose/analysis ; Intracranial Pressure ; Lactic Acid/cerebrospinal fluid ; Lactic Acid/blood ; Lactic Acid/analysis ; Lipid Peroxidation/physiology ; Meningitis, Bacterial/physiopathology* ; Meningitis, Bacterial/metabolism* ; Na(+)-K(+)-Exchanging ATPase/metabolism ; Spectroscopy, Near-Infrared ; Swine

We evaluated the effects of a combined therapy of pre-blockade endogenous nitric oxide synthase (NOS) with N-nitro-L-arginine methyl ester (L-NAME) and continuous inhaled NO (iNO) on the gas exchange and hemodynamics of Escherichia coli pneumonia and sepsis in newborn piglets. Seven to ten day old ventilated newborn piglets were randomized into 5 groups: control, E. coli pneumonia control, pneumonia with iNO 10 ppm, pneumonia pre-treated with L-NAME 10 mg/kg, and pneumonia with the combined therapy of L-NAME pretreatment and iNO. E. coli pneumonia was induced via intratracheal instillation of Escherichia coli, which resulted in progressively decreased cardiac index and oxygen tension; increased pulmonary vascular resistance index (PVRI), intrapulmonary shunting, and developed septicemia at the end of 6 hr experiment. iNO ameliorated the progressive hypoxemia and intrapulmonary shunting without affecting the PVRI. Only two of 8 animals with L-NAMEpretreated pneumonia survived. Whereas when iNO was added to infected animals with L-NAME pretreatment, the progressive hypoxemia was abolished as a result of a decrease in intrapulmonary shunting without reverse of the high PVRI and systemic vascular resistance index induced by the L-NAME injection. This result suggests that a NOS blockade may be a possible supportive option for oxygenation by iNO treatment in neonatal Gram-negative bacterial pneumonia and sepsis.
Treatment Outcome ; Swine ; Survival Rate ; Sepsis/diagnosis/drug therapy/physiopathology ; Pulmonary Gas Exchange/*drug effects ; Premedication/*methods ; Pneumonia, Bacterial/diagnosis/*drug therapy/physiopathology ; Oxygen Consumption/*drug effects ; Nitric Oxide Synthase/antagonists & inhibitors ; Nitric Oxide/*administration & dosage ; NG-Nitroarginine Methyl Ester/*administration & dosage ; Injections, Intravenous ; Escherichia coli Infections/diagnosis/*drug therapy/physiopathology ; Drug Therapy, Combination ; Animals, Newborn ; Animals ; Administration, Inhalation

We evaluated the effects of a combined therapy of pre-blockade endogenous nitric oxide synthase (NOS) with N-nitro-L-arginine methyl ester (L-NAME) and continuous inhaled NO (iNO) on the gas exchange and hemodynamics of Escherichia coli pneumonia and sepsis in newborn piglets. Seven to ten day old ventilated newborn piglets were randomized into 5 groups: control, E. coli pneumonia control, pneumonia with iNO 10 ppm, pneumonia pre-treated with L-NAME 10 mg/kg, and pneumonia with the combined therapy of L-NAME pretreatment and iNO. E. coli pneumonia was induced via intratracheal instillation of Escherichia coli, which resulted in progressively decreased cardiac index and oxygen tension; increased pulmonary vascular resistance index (PVRI), intrapulmonary shunting, and developed septicemia at the end of 6 hr experiment. iNO ameliorated the progressive hypoxemia and intrapulmonary shunting without affecting the PVRI. Only two of 8 animals with L-NAMEpretreated pneumonia survived. Whereas when iNO was added to infected animals with L-NAME pretreatment, the progressive hypoxemia was abolished as a result of a decrease in intrapulmonary shunting without reverse of the high PVRI and systemic vascular resistance index induced by the L-NAME injection. This result suggests that a NOS blockade may be a possible supportive option for oxygenation by iNO treatment in neonatal Gram-negative bacterial pneumonia and sepsis.
Treatment Outcome ; Swine ; Survival Rate ; Sepsis/diagnosis/drug therapy/physiopathology ; Pulmonary Gas Exchange/*drug effects ; Premedication/*methods ; Pneumonia, Bacterial/diagnosis/*drug therapy/physiopathology ; Oxygen Consumption/*drug effects ; Nitric Oxide Synthase/antagonists & inhibitors ; Nitric Oxide/*administration & dosage ; NG-Nitroarginine Methyl Ester/*administration & dosage ; Injections, Intravenous ; Escherichia coli Infections/diagnosis/*drug therapy/physiopathology ; Drug Therapy, Combination ; Animals, Newborn ; Animals ; Administration, Inhalation

OBJECTIVETo investigate the expression of glial fibrillary acidic protein (GFAP), GFAP mRNA and interleukin-1beta mRNA (IL-1beta mRNA), tumor necrosis factor-alpha mRNA (TNF-alpha mRNA) in neonatal rat brain after intrauterine infection.

METHODSEscherichia coli (E. coli) was inoculated into both uterine horns of pregnant rats when gestation was 70% complete (15 days). The control group was treated with normal saline. The pups were killed on the postnatal day 1 (P1), P3 and P7, respectively. The cerebral white matter damage of the neonatal rats was determined by HE staining. Immunohistochemistry was used for evaluation of GFAP expression in neonatal rat brains and RT-PCR to analyze GFAP mRNA, IL-1beta mRNA and TNF-alpha mRNA expression at P1, P3 and P7.

RESULTSThe major histopathological changes in neonatal cerebral white matter at P7 after intrauterine infections were: weak staining of cerebral white matter and focal rarefaction. GFAP-positive cells were observed in both the control and the E. coli-treated groups. The numbers of GFAP-positive cells of the E. coli-treated group pups were markedly increased in periventricular white matter and hippocampus at P7 compared with those of the control group (periventricular white matter: 9.73 +/- 3.55 vs 5.67 +/- 1.90, P < 0.05 and hippocampus: 7.81 +/- 3.61 vs 2.16 +/- 1.11, P < 0.05, respectively). No significantly different levels of GFAP expression in corpus callosum were found between two groups (P > 0.05). The expression of GFAP mRNA in brain of the E. coli-treated neonatal rat was higher than the control at P1, P3 (P1: 0.25 +/- 0.07 vs 0.15 +/- 0.08, P < 0.05 and P3: 0.50 +/- 0.09 vs 0.39 +/- 0.08, P < 0.05, respectively), but the expression of GFAP mRNA in brain of the neonatal rat at P7 had no significant difference between two groups (P > 0.05). The expression of IL-1beta mRNA and TNF-alpha mRNA in brain of the E. coli-treated neonatal rat were higher than of the control at P1 (IL-1beta mRNA: 0.83 +/- 0.19 vs 0.50 +/- 0.30, P < 0.05 and TNF-alpha mRNA: 0.74 +/- 0.30 vs 0.30 +/- 0.20, P < 0.05, respectively), but the expression of IL-1beta mRNA and TNF-alpha mRNA in brain of the neonatal rat at P3 and P7 had no significant difference between two groups (P > 0.05).

CONCLUSIONSThe intrauterine infection could cause neonatal white matter damage and IL-1beta, TNF-alpha may be a mechanism mediating between the two events.

Animals ; Animals, Newborn ; Brain ; metabolism ; pathology ; Disease Models, Animal ; Escherichia coli Infections ; microbiology ; physiopathology ; Female ; Glial Fibrillary Acidic Protein ; analysis ; genetics ; Immunohistochemistry ; Interleukin-1 ; genetics ; Pregnancy ; Pregnancy Complications, Infectious ; microbiology ; physiopathology ; RNA, Messenger ; metabolism ; Rats ; Reverse Transcriptase Polymerase Chain Reaction ; Tumor Necrosis Factor-alpha ; genetics ; Uterus ; microbiology