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N,N’-bis(2-chloroethyl)-N-nitrosourea (BCNU) is one of the major drugs used in chemotherapy against malignant gliomas due to its effects, such as induction of bifunctional alkylation of DNA and formation of interstrand DNA cross-linkages, and induces cortical malformations in the fetal and neonatal rat brain. In this study, pregnant rats were treated with 7.5 mg/kg of BCNU on gestational day 13 (GD 13), and their fetuses were collected from 12 to 72 hours after BCNU treatment in order to examine the timecourses of morphological and immunohistochemical changes in neural progenitor cells in the developing brain. The number of pyknotic cells in the telencephalon peaked at 24 h and then gradually decreased until 72 h. The majority of these pyknotic cells were positive for cleaved caspase-3, a key executioner of apoptosis. The pyknotic cells showed the ultrastructural characteristics of apoptosis. The number of p53-positive cells began to increase prior to the appearance of apoptotic cells and p21-positive cells. The number of phosphorylated-histone H3-positive cells (mitotic cells) decreased from 24 to 36 h. The number of Iba1-positive cells (microglial cells) in the telencephalon increased from 12 to 48 h. These results suggest that BCNU induces p53-dependent apoptosis and reduces proliferative activity, resulting in reduction of the weight of the telencephalon and the thickness of the telencephalic wall in the fetal brain. This study will help to clarify the mechanisms of BCNU-induced fetal brain toxicity.

We conducted a study to assess the precise incidence of anaerobic infections among patients with pulmonary diseases in Japan. To avoid false-negative results of anaerobic cultures, we used percutaneous transtracheal aspiration and subsequent immediate bedside anaerobic inoculation onto a set of plates with appropriately selected culture media. Fifty-six episodes of pulmonary disease occurred in 50 patients; anaerobes were isolated in 20 (36%) of these episodes. Bacteria were recovered in 30 (94%) of 32 episodes not associated with prior antimicrobial therapy, and anaerobes were isolated in 15 (47%) of these 32 episodes. Rates of anaerobic isolation in episodes of pneumonia (7 of 14), lung abscess (3 of 3), and acute exacerbation of chronic lower respiratory tract infection (5 of 15) that were not associated with prior antimicrobial therapy were 50%, 100%, and 33%, respectively.