Prevalence of Coxiella burnetii infection in dairy cattle with reproductive disorders

The prevalence of Coxiella burnetii infection in 207 cattle with reproductive disorders was studied by using an indirect immunofluorescence (IF) test, nested polymerase chain reaction (PCR) and isolation. IF antibodies to phase I and phase II antigens of C. burnetii were found in 122 (58.9%) and 125 (60.4%) of the sera, respectively, and PCR-positives were found in 8 (3.9%) of the sera and in 51 (24.6%) of the milk samples. In addition, C. burnetii was isolated from 51 (24.6%) of the milk samples by inoculating laboratory mice. The results indicate that the IF test plus PCR are useful in the diagnosis of bovine coxiellosis. It is difficult to deny that dairy cattle with reproductive disorders would be one of the important reservoirs of C. burnetii responsible for infection in both animal and human populations in Japan.     

Technology for in situ ablation by laparoscopic and image-guided interstitial laser hyperthermia

The effects of low level lead exposure on synaptic plasticity in hippocampal regions CA1 and CA3 were determined in adult rats in vitro. In the CA3 region the NMDA (N-methyl-D-aspartate)-independent mossy fiber-CA3 synapse potentiation was not influenced by chronic pre- and postnatal lead exposure, while in the same rats, in the CA1 region the NMDA-dependent long-term potentiation was slightly reduced as compared to controls. Paired-pulse facilitation was neither impaired in CA1 nor in CA3 region in the lead-exposed rats. These findings suggest that NMDA-dependent forms of synaptic plasticity are more susceptible to chronic low level lead exposure than NMDA-independent forms of potentiation or paired-pulse facilitation.     

Outbreak of Pseudomonas fluorescens bacteremia among oncology patients

From 7 to 24 March 1997, four patients developed Pseudomonas fluorescens bacteremia at the hospital; one on the oncology ward and the other three in the chemotherapy room. These patients all had underlying malignancies and had the Port-A-Cath (Smiths Industries Medical Systems, Deltec, Inc., St. Paul, Minn.) implants. Three patients had primary bacteremia, and one had Port-A-Cath-related infection. None of these patients had received a blood transfusion before the episodes of bacteremia. All patients recovered: two received antimicrobial agents with in vitro activity against the isolates, and the other two did not have any antibiotic treatment. A total of eight blood isolates were recovered from these patients during the febrile episodes that occurred several minutes after the infusion of chemotherapeutic agents via the Port-A-Cath. These isolates were initially identified as P. fluorescens or Pseudomonas putida (four), Burkholderia (Ralstonia) pickettii (three), and a non-glucose-fermenting gram-negative bacillus (one) by routine biochemical methods and the Vitek GNI card. These isolates were later identified as P. fluorescens on the basis of the characteristic cellular fatty acid chromatogram and the results of supplemental biochemical tests. The identification of identical antibiotypes by the E test and the random amplified polymorphic DNA patterns generated by arbitrarily primed PCR of the isolates showed that the outbreak was caused by a single clone of P. fluorescens. Surveillance cultures of the possibly contaminated infusion fluids and disinfectants, which were performed 7 days after recognition of the last infected patient, failed to isolate P. fluorescens. This report of a small outbreak caused by P. fluorescens suggests that timely, accurate identification of unusual nosocomial pathogens is crucial for early initiation of an epidemiological investigation and timely control of an outbreak.     

Hyperglycemia increases neurological damage and behavioral deficits from post-traumatic secondary ischemic insults

The effects of post-traumatic administration of glucose 2.0 g/kg was compared to saline infusion with and without control of brain temperature at 37 degrees C on behavioral and histological measures of brain injury after controlled cortical impact injury complicated by a secondary ischemic insult. The glucose infusion increased blood glucose concentration from 114 +/- 4 to 341 +/- 76 mg/dl prior to the secondary ischemic insult. The resulting outcome measures were significantly worse in the glucose infusion group than in either control group. Mortality rate was significantly increased by the glucose administration, from 0% to 55% (p < 0.001). The median contusion volume was increased from 7.9 to 64.2 by glucose administration (p < 0.001) and the neuronal loss in the CA1 and CA3 areas of the hippocampus were greater in the glucose infusion group. In the animals that survived for the 2 weeks of behavioral studies, the duration of beam balance was shorter; the percent of animals that could balance on the beam for at least 60 s was less, the percent of animals that could perform the beam-walking task was less, and the length of time required to find the platform in the Morris water maze task was longer in the glucose infusion group. These studies demonstrate that the infusion of glucose after the cortical impact injury significantly increases the damage caused by post-traumatic ischemic insults. The adverse effect on neurological outcome could not be explained by the temperature effects of glucose infusion.     

Acetylene reduction (nitrogen fixation) associated with corn inoculated with Spirillum

Sorghum and corn breeding lines were grown in soil in field and greenhouse experiments with and without an inoculum of N2-fixing in Spirillum strains from Brazil. Estimated rates of N2 fixation associated with field-grown corn and sorghum plants were less than 4 g of N2/ha per day. The mean estimated N2-fixation rates determined on segments of roots from corn inoculated with Spirillum and grown in the greenhouse at 24 to 27 degrees C were 15 g of N2/ha per day (16 inbreds), 25 g of N2/ha per day (six hybrids), and 165 g of N2/ha per day for one hybird which was heavily inoculated. The corresponding mean rates determined from measurements of in situ cultures of the same series of corn plants (i.e., 16 inbreds, six hybrids, and one heavily inoculated hybrid) were 0.4, 2.3, and 1.1 g of N2/ha per day, respectively. Lower rates of C2H2 reduction were associated with control corn cultures which had been treated with autoclaved Spirillum than with cultures inoculated with live Spirillum. No C2H2 reduction was detected in plant cultures treated with ammonium nitrate. Numbers of nitrogen-fixing bacteria on excised roots of corn plants increased an average of about 30-fold during an overnight preincubation period, and as a result acetylene reduction assays of root samples after preincubation failed to serve as a valid basis for estimating N2 fixation by corn in pot cultures. Plants grown without added nitrogen either with or without inoculum exhibited severe symptoms of nitrogen deficiency and in most cases produced significantly less dry weight than those supplied with fixed nitrogen. Although substantial rates of C2H2 reduction by excised corn roots were observed after preincubation under limited oxygen, the yield and nitrogen content of inoculated plants and the C2H2-reduction rates by inoculated pot cultures of corn, in situ, provided no evidence of appreciable N2 fixation.     

Inhibition of the reoxidation of the secondary electron acceptor of photosystem II by bicarbonate depletion

Intravenous infusion of 600 ng/kg/min of 1-sarcosine, 8-isoleucine-angiotensin II, an angiotensin II antagonist, caused a marked blood pressure fall and a decrease in plasma aldosterone in 3 patients with Bartter's syndrome. These results indicate that proximal cause of Bartter's syndrome is an arteriolar hyporesponsiveness to angiotensin II and that this angiotensin II analogue has an antagonist activity on peripheral arterioles as well as adrenal cortex.