Suppurative meningoencephalitis and perineuritis caused by Streptococcus gallolyticus in a Japanese Black calf

A 179-day-old calf, which was weak and stunted, showed neurological signs and was euthanized. Postmortem examination revealed extensive and severe cloudy area in the meninges, and pleural pneumonia. Gram-positive cocci were isolated from systemic organs. Biochemical and 16S rRNA gene sequence analyses identified the isolate as Streptococcus gallolyticus, and its subspecies was suggested to be gallolyticus (SGG). The isolate was classified as a novel sequence type (ST115) by the multilocus sequence typing scheme for SGG and showed susceptibility to penicillin, ampicillin, amoxicillin, florfenicol, sulfamethoxazole-trimethoprim, and chloramphenicol. Histopathologically, suppurative meningoencephalitis and perineuritis were detected. As SGG has been isolated solely from a cow with mastitis in Japan, this is the first SGG infection in a calf with suppurative meningoencephalitis and perineuritis in this country.     

C and N natural abundance of the soil microbial biomass

Stable isotope analysis is a powerful tool in the study of soil organic matter formation. It is often observed that more decomposed soil organic matter is ¹³C, and especially ¹⁵N-enriched relative to fresh litter and recent organic matter. We investigated whether this shift in isotope composition relates to the isotope composition of the microbial biomass, an important source for soil organic matter. We developed a new approach to determine the natural abundance C and N isotope composition of the microbial biomass across a broad range of soil types, vegetation, and climates. We found consistently that the soil microbial biomass was ¹⁵N-enriched relative to the total (3.2 ‰) and extractable N pools (3.7 ‰), and ¹³C-enriched relative to the extractable C pool (2.5 ‰). The microbial biomass was also ¹³C-enriched relative to total C for soils that exhibited a C3-plant signature (1.6 ‰), but ¹³C-depleted for soils with a C4 signature (−1.1 ‰). The latter was probably associated with an increase of annual C3 forbs in C4 grasslands after an extreme drought. These findings are in agreement with the proposed contribution of microbial products to the stabilized soil organic matter and may help explain the shift in isotope composition during soil organic matter formation.     

Arrhythmogenic effect of hypercapnia in ducks anesthetized with halothane

OBJECTIVE: To determine effects of hypercapnia on arrhythmias in ducks anesthetized with halothane. ANIMALS: 12 ducks, 6 to 8 months old, weighing 1.1 to 1.6 kg. PROCEDURES: Each duck was anesthetized with a 1.5% mixture of halothane in oxygen, and anesthetic depth was stabilized during a 20-minute period. We added CO2 to the inspired oxygen to produce CO2 partial pressures of 40, 60, and 80 mm Hg in the inspired gas mixture.The CO2 partial pressure was increased in a stepwise manner. When arrhythmias were not evident during inhalation of the gas mixture at a specific CO2 partial pressure, the CO2 partial pressure was maintained for 10 minutes before a sample was collected for blood gas analysis. When arrhythmias were detected, a sample for blood gas analysis was collected after the CO2 partial pressure was maintained for at least 2 minutes, and CO2 inhalation then was terminated. RESULTS: During the stabilization period, PaCO2 (mean +/- SD) was 33 +/- 5 mm Hg,and arrhythmias were not detected. In 6 ducks, arrhythmias such as unifocal and multifocal premature ventricular contractions developed during inhalation of CO2. Mean PaCO2 at which arrhythmias developed was 67 +/- 12 mm Hg. In 5 of 6 ducks with arrhythmias, the arrhythmias disappeared after CO2 inhalation was terminated. CONCLUSION AND CLINICAL RELEVANCE: Analysis of data from this study indicated that hypercapnia can lead to arrhythmias in ducks during halothane-induced anesthesia. Thus, ventilatory support to maintain normocapnia is important for managing ducks anesthetized with halothane.     

Effects of carbon and nitrogen amendment on soil carbon and nitrogen mineralization in volcanic immature soil in southern Kyushu,Japan

Soil N mineralization is affected by microbial biomass and respiration, which are limited by available C and N. To examine the relationship between C and N for soil microbial dynamics and N dynamics, we conducted long-term laboratory incubation (150 days) after C and N amendment and measured changes in C and N mineralization, microbial biomass C, and dissolved C and N throughout the incubation period. The study soil was volcanic immature soil from the southern part of Japan, which contains lower C and N compared with other Japanese forest soils. Despite this, the area is covered by well-developed natural and plantation forests. Carbon amendment resulted in an increase in both microbial biomass and respiration, and net N mineralization decreased, probably due to increasing microbial immobilization. In contrast, N amendment resulted in a decrease in microbial respiration and an increase in net N mineralization, possibly due to decreased immobilization by microbes. Amendment of both C and N simultaneously did not affect microbial biomass and respiration, although net N mineralization was slightly increased. The results suggested that inhibitory effect on microbial respiration by N amendment should be reduced if carbon availability is higher. Thus, soil available C may limit microbial biomass and respiration in this volcanic immature soil. Even in immature soil where C and N substrate is low, soil C, such as plant root exudates and materials from above- and belowground dead organisms, might help to maintain microbial activity and N mineralization in this study site.     

Investigation of relationships between cell and pulp properties in Eucalyptus by examination of within-tree property variations

 Relationships between cell and pulp properties were investigated by examining the within-tree property variations in Eucalyptus camaldulensis and Eucalyptus globulus. Properties investigated included proportions of ray and axial parenchyma, thickness of cell walls and cell wall percentages. The characteristics of the ray and axial parenchyma (their proportions and wall thickness) were found to have a significant influence on all measured pulp properties, including paper strength properties. Multiple regression of pulp properties in relation to cell properties revealed that nearly all measured pulp properties were explained by cell properties at the 1% significance level. It was concluded, therefore, that all cell types are important for predicting pulp properties, and it is strongly recommended that tree breeding programs for Eucalyptus include the measurement of all cell types. Received 6 July 1999     

Time course of the incidence/multiplicity and histopathological features of murine colonic dysplasia,adenoma and adenocarcinoma induced by benzo[a]pyrene and dextran sulfate sodium

Benzo[a]pyrene (BP) is mutagenic but noncarcinogenic in the murine colon. Recently, we reported rapid induction of colonic tumors by treatment of CD2F₁ mice with BP (125 mg/kg for 5 days) followed by a colitis inducer, dextran sulfate sodium (DSS) (4% in drinking water for 1 or 2 weeks). However, there are no reports on detailed time course and histopathological features of colonic proliferative lesions in this model. Here, we show the detailed time course of colonic dysplasia, adenoma and adenocarcinoma induced by treatment with BP, DSS, and a combination of the two (BP/DSS). In the colon of mice exposed to BP/DSS, 14.6 dysplastic foci per mouse were present one week after DSS treatment (week 4). The number of dysplastic foci decreased with time to 3.1 at week 9 and thereafter remained almost constant. At week 4, 1.5 adenocarcinomas were also observed, with a marked increase in numbers with time, reaching 29.3 at week 14. In contrast, the number of dysplastic foci induced by DSS alone showed a time course similar to that following BP/DSS treatment; however, only a few tumors appeared. Neither dysplastic foci nor neoplastic lesions were induced by BP only. In mice exposed to BP/DSS, β-catenin was demonstrated immunohistochemically in the nucleus and/or cytoplasm of the tumor cells, and this translocation from the cell membrane was evident in subsets of dysplastic foci. In dysplastic foci induced by DSS alone, β-catenin was absent in the nucleus/cytoplasm. These finding suggest that aberrant β-catenin accumulation in dysplastic foci is associated with tumor progression in this BP/DSS model.