Computer experiments to determine whether over- or under-counting necessarily affects the determination of difference in cell number between experimental groups.

Computer cell counting experiments were performed in order to examine the consequences of over- or under-counting. The three-dimensional reaggregate culture laboratory environment for cell counting was used as a model for computer simulation. The laboratory environment for aggregate and cell sizes, numbers and spatial placement in gelatin blocks was mimicked in the computer setup. However, in the computer, cell counting was set to be either ideally unbiased, or deliberately biased in regard to over- or under-counting so as to compare eventual results when using the various cell counting methods. It was found that there was no effect of the cell counting methods used in determining whether there was a significant difference in cell number between two experimental groups. In addition, it was found that under the conditions of these simulations, the optical dissector method behaved similarly, on the average, as the ideal method of counting cell centers and in both of those cases, the average ratio between actual cell number in a flask and estimated number was close to 1.00.

Examination of caspase-dependent apoptotic and necrotic changes in rat kidney exposed to different doses of permethrin.

We investigated dose-related pathological alterations and apoptosis in rat kidney tissue exposed to permethrin. Histopathological findings, apoptotic cell death and urinary 3-phenoxybenzoic acid concentrations (3-PBA) were evaluated. Different doses of permethrin were administered to animals by oro-gastric gavage. A dose-dependent increase of urine 3-PBA concentration was observed in all the permethrin-treated groups. SDS-PAGE separated 30-45 kD and 100-220 kD protein bands in all experimental groups. Histopathologically, degenerative changes were observed in the epithelial lining of the S1, S2, and S3 segments of the renal proximal tubules. Apoptotic cells were seen in the inner stripe of the outer medulla in Group I, and both the cortex and medulla in Groups II and III. Immunohistochemical staining of caspase 3 and caspase 9 also was observed in the same areas. Our results suggest that damage to regions of the proximal tubules is dose-related, and caspase-9-dependent, mitochondria-related apoptotic cell death could play an important role in permethrin-induced nephrotoxicity. We also observed morphologically necrotic cells. We concluded that both necrosis and apoptosis are produced by permethrin.

A variant of the Ekman-Westborg and Julin trait.

Ekman-Westborg and Julin is a trait that shows multiple macrodontia and multituberculism affecting only the teeth with no other anomalies (E-WJ). The aim of this report is to present a case which appears to manifest all the clinical signs of the E-WJ trait including odontoma formation. A 18-year-old girl with gingival inflammation particularly in the maxillary insicor area was referred to the authors' department. Panoramic, periapical and cephalometric radiographs were examined and complex odontoma associated with unerupted maxillary permanent lateral incisors was revealed. Intraoral examination revealed anterior crossbite, Angle Class III type malocclusion with mandibulary prominence and macrodontia of teeth 37, 12, 11 and 21. The patient was accepted as a new sporadic case of E-WJ. More case reports are needed to elucidate the causes and pathogenesis of this condition.