Changes in distribution of basic nuclear proteins and chromatin organization during spermiogenesis in the greater bandicoot rat, Bandicota indica.

Male germ cells of the greater bandicoot rat, Bandicota indica, have recently been categorized into 12 spermiogenic steps based upon the morphological appearance of the acrosome and nucleus and the cell shape. In the present study, we have found that, in the Golgi and cap phases, round spermatid nuclei contain 10-nm to 30-nm chromatin fibers, and that the acrosomal granule forms a huge cap over the anterior pole of nucleus. In the acrosomal phase, many chromatin fibers are approximately 50 nm thick; these then thickened to 70-nm fibers and eventually became 90-nm chromatin cords that are tightly packed together into highly condensed chromatin, except where nuclear vacuoles occur.

Magnetic resonance imaging study of the craniocervical junction.

Purpose: To confirm the accuracy of the standard parameters of Chamberlain's line, McGregor's line, McRae's line, and Ranawat's line in the diagnosis of basilar impression in a normal Asian population using magnetic resonance imaging (MRI) scans of the craniocervical junction, and to evaluate the use of MRI in the initial diagnosis of basilar impression.

Methods: We retrospectively reviewed MRI scans of the craniocervical junction in 114 Thai patients (61 men and 53 women) aged 20 to 89 years to assess the lines of Chamberlain, McGregor, McRae, and Ranawat. Patients with injury, tumour, or metastasis in the craniocervial junction; congenital anomalies; or clinical symptoms and signs of basilar impression were excluded.

Unusual germ cell organization in the seminiferous epithelium of a murid rodent from southern Asia, the greater bandicoot rat, Bandicota Indica.

In the greater bandicoot rat, Bandicota indica, of south-east Asia, nine cell associations were documented in the testicular seminiferous epithelium. In about 10% of the tubule cross sections two or more cell associations occurred and, furthermore, some of the generations of germ cells within the cell associations were sometimes either out of phase, or missing, in the tubule cross sections. These features, together with the fact that this species has a highly pleiomorphic sperm head shape, are somewhat reminiscent of those of the seminiferous epithelium in humans and some other primates but not of common laboratory rodents.