Carrier state in human acatalasemia

The heterozygous carrier state of a rare hereditary disease, acatalasemia, has been defined biochemically. Affected homozygotes have no blood catalase activity, whereas heterozygotes show activities intermediate between this inactivity and the activity of normal controls, without overlap. Pedigrees show a high frequency of consanguineous marriages.     

Immunohistochemical and histoplanimetrical study on the endothelial receptor involved in transportation of minute chylomicrons into subepithelial portal blood in intestinal villi of the rat jejunum

A portion of the minute chylomicrons less than 75 nm in diameter are transcytosed from the extravascular tissue into the subepithelial blood capillaries (sBC) in the villous apices of the rat jejunum. However, the details of the transportation mechanism have not been clarified. In this study, the endothelial receptor involved in the transportation of minute chylomicrons into the sBC’s lumina was immunohistochemically and histoplanimetrically examined in intestinal villi of the rat jejunum. Immunopositivity for very low density lipoprotein (VLDL) receptor was detected on the luminal and basal surfaces of the endothelial cells of sBC in approximately 68% of those apices of jejunal villi that possessed numerous chylomicrons in the lamina propria, while VLDL receptor was detected on the endothelial cells of sBC in only approximately 8% of intestinal villi that possessed few or no chylomicrons in the lamina propria. No immunopositivity for LDL receptor was detected in the sBC of all intestinal villi. These findings suggest that VLDL receptor is expressed by the endothelial cells of the sBC in conjunction with the filling of the lamina propria of jejunal villi with many chylomicrons produced by the villous columnar epithelial cells and that the VLDL receptor mediates the transportation of minute chylomicrons, maybe VLDL, into the subepithelial portal blood from the extravascular tissue of the rat jejunal villi.     

Biological Control of Soft Rot of Chinese Cabbage Using Single and Mixed Treatments of Bacteriocin-producing Avirulent Mutants of Erwinia carotovora subsp. carotovora

Two pathogenic strains of E. carotovora subsp. carotovora 2T-2 and TT-4 with high bacteriocin activity but low sensitivity to the bacteriocins of other strains were treated with ethyl methane sulphonate (EMS). Two avirulent mutants A-f-39 and B-e-19 developed from 2T-2 and TT-4, respectively, by this treatment had the same bacteriocin activity as their respective parents and inhibited the in vitro growth of pathogenic strains of this species. The disease control of these two mutant strains were compared in the field in 1995 and 1997 to the control by CGE234M403 (M403) (a commercialized biocontrol agent), a mixture of A-f-39 and M403, and an agrochemical (basic dithianon-copper chloride). The protection obtained with A-f-39 was comparable to M403 and was better than that with the chemical. The mixture of A-f-39 and M403 consistently gave the best results in all the field trials. Received 17 September 1999/ Accepted in revised form 22 February 2000     

Immunohistochemical study on the secretory host defense system of bactericidal peptides in rat digestive organs

To clarify the fundamental regulation mechanism against indigenous bacterial proliferation in the alimentary tract, we immunohistochemically examined the localization of 4 bactericidal peptides (BP) in the rat digestive exocrine glands. In the upper alimentary tract, lysozyme was detected in the gustatory, extraorbital lacrimal and parotid glands. Secretory phospholipase A2 (sPLA2) was detected in the extraorbital lacrimal glands. β-defensin1 was detected in the gustatory and extraorbital lacrimal glands. β-defensin2 was detected in the Harderian glands. In the stomach, β-defensins were detected in the gastric superficial epithelial cells. In the small and large intestines, only lysozyme and sPLA2 were detected in the Paneth cells. In the cecum, all 4 BP were detected in the middle to apical portions of the crypts, and only sPLA2 was detected in the basal portion. No BP were localized in other exocrine glands associated with the alimentary tract. In addition, all 4 BP were also detected in the columnar epithelial cells of the apical portions of intestinal villi. In the intestinal superficial epithelial cells, lysozyme and β-defensins were detected in the ascending colon, whereas only β-defensin1 was detected in the descending colon and rectum. These results suggest that BP are mainly secreted from exocrine tissues in the initial portion of the digestive tract and play a role in host defense against indigenous bacteria throughout the digestive tract. Part of the BP in the chyme might be absorbed by the epithelium at the most inner sites of mucosae in the small and large intestines.