Septal pore apparatus and nuclear division of Auriscalpium vulgare.

Ultrastructure of the septal pore apparatus and nuclear division of Auriscalpium vulgare (Russulales) was examined with freeze substitution and is presented for inclusion in the AFTOL Structural and Biochemical Database (http://aftol.umn.edu). Previously unreported septal characters for the Russulales (Agaricomycotina) were observed: Septa of the hymenophore had bell-shaped perforated septal pore caps that may extend along the septum and a zone of organelle exclusion surrounded the septal pore apparatus. Metaphase I of meiosis and metaphase of mitosis were similar. Globular spindle pole bodies with electron-opaque inclusions were set within polar fenestrae of the nuclear envelope. The nuclear envelope was mostly intact with occasional gaps. Fragments of endoplasmic reticulum were present near the spindle pole bodies but did not form a polar cap. Structural characters may distinguish one or more clades of the Agaricomycotina and provide additional signal in phylogenetic analyses.

Microwave processing for sample preparation to evaluate mitochondrial ultrastructural damage in hemorrhagic shock.

This is a report of the adaptation of microwave processing in the preparation of liver biopsies for transmission electron microscopy (TEM) to examine ultrastructural damage of mitochondria in the setting of metabolic stress. Hemorrhagic shock was induced in pigs via 35% total blood volume bleed and a 90-min period of shock followed by resuscitation. Hepatic biopsies were collected before shock and after resuscitation. Following collection, biopsies were processed for TEM by a rapid method involving microwave irradiation (Giberson, 2001). Samples pre- and postshock of each of two animals were viewed and scored using the mitochondrial ultrastructure scoring system (Crouser et al., 2002), a system used to quantify the severity of ultrastructural damage during shock. Results showed evidence of increased ultrastructural damage in the postshock samples, which scored 4.00 and 3.42, versus their preshock controls, which scored 1.18 and 1.27. The results of this analysis were similar to those obtained in another model of shock (Crouser et al., 2002). However, the amount of time used to process the samples was significantly shortened with methods involving microwave irradiation.