Hepatitis B virus-associated membranous glomerulonephropathy

A variety of extrahepatic abnormalities have been described in patients with hepatitis B viral infection, including the prodromal arthritis (serum sickness-like) syndrome, polyarteritis nodosa, and glomerulonephropathy. Five patients with hepatitis B virus (HBV)-associated membranous glomerulonephropathy (MGN) were persistent carriers of HBsAg. The deposition of HBsAg in the renal lesions of these patients was proved by using monospecific antibody and immunofluorescence technique. These findings support the hypothesis of an etiological correlation of hepatitis B viral infection with some cases of MGN. HBV-associated MGN may be much more frequent in the world than previously reported, and more cases must be collected for the understanding of this unique entity.

Human stomach alcohol and aldehyde dehydrogenases (ALDH): a genetic model proposed for ALDH III isozymes

Isozyme phenotypes of alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) from human gastroendoscopic as well as surgical gastric biopsies were determined by starch gel electrophoresis and agarose isoelectric focusing. gamma gamma ADH isozymes were expressed predominantly in the mucosal layer of the stomach, whereas beta beta isozymes were in the muscular layer. In the 56 gastroendoscopic mucosal biopsies examined, the homozygous ADH3 1-1 phenotype was found in 75% of the samples, and the heterozygous ADH3 2-1 phenotype in 25%. Accordingly, the gene frequencies of the alleles ADH1/3 and ADH2/3 were calculated to be 0.88 and 0.12, respectively. Using a modified agarose isoelectric focusing procedure, gastric ALDH I, ALDH II, and up to five ALDH III forms could be clearly resolved. The ALDH III isozymes accounted for more than 80% of the total ALDH activities in gastric mucosa and exhibited Km values in the millimolar range for propionaldehyde at pH 9.0. Forty-five percent of the 55 gastroendoscopic biopsies studied lacked ALDH I isozyme. The complex gastric ALDH III isozyme phenotypes seen in these biopsies fall into three patterns. They can be interpreted by a genetic hypothesis, based on a dimeric molecule, in which there are two separate genes, ALDH3a and ALDH3b, with the ALDH3b locus exhibiting polymorphism. The homozygous phenotypes ALDH3b 1-1 and ALDH3b 2-2 were found to be 4 and 76%, respectively, and the heterozygous ALDH3b 2-1 phenotype 20%, of the total. Therefore, the allele frequencies for ALDH1/3b and ALDH2/3b were calculated to be 0.14 and 0.86, respectively. Several lines of biochemical evidence consistent with this genetic model are discussed.

A case study of hospital operations management

This paper discusses a study to investigate various operations management problems in a newly opened, modern regional hospital in Hong Kong. The findings of the study reveal that there exist in the hospital a number of current and potential problem areas. Recommendations for solving these problems are suggested with a view to improving the overall operational efficiency and effectiveness of the hospital.

Thalassemia due to a mutation in the cleavage-polyadenylation signal of the human beta-globin gene

A beta-globin gene cloned from a person with beta-thalassemia contained a T----C substitution within the conserved sequence AATAAA that forms a portion of the recognition signal for endonucleolytic cleavage and polyadenylation of primary mRNA transcripts. By Northern blot analysis a novel beta-globin RNA species, 1500 nucleotides in length, was detected in erythroid RNA. Nuclease protection studies of erythroid RNA, as well as RNA generated upon transient expression of the cloned mutant gene in HeLa cells, located the 3' terminus of this novel, polyadenylated RNA 900 nucleotides downstream of the normal poly(A) addition site, within 15 nucleotides of the first AATAAA in the 3'-flanking region of the beta-globin gene. These findings define the in vivo terminus of an elongated RNA and establish that human beta-globin transcription may extend at least 900 nucleotides 3' of the normal polyadenylation site.

A lectin on the hemocyte membrane of the oyster (Crassostrea virginica)

Using antisera produced against a serum lectin we have shown by employing immunocytofluorescence that hemocytes from the oyster, Crassostrea virginica, possess a lectin which is situated on the external surface of the cell membrane. The antisera block the binding of hemocyte microsomes to protease-treated vertebrate erythrocytes, thus confirming that the hemocyte membrane lectin is serologically related to the serum lectin. The major serum lectin has an apparent mass of 34,000. Flow cytometry has revealed that the distribution of the surface lectin on hemocytes represents a heterogeneous expression on a population basis, but no discrete cell subpopulations can be identified.

Genetic selection for tolerance to niclosamide and copper in Biomphalara glabrata (Mollusca: Pulmonata)

Successive generations of the PR-79 and M-line laboratory stocks of Biomphalaria glabrata were exposed in the LC90 of niclosamide or copper sulfate. Survivors from each generation produced the succeeding generation by self fertilization. The PR-79 stock showed no evidence of tolerance to either molluscicide following five generations of selection. On the other hand, M-line F5 snails demonstrated approximately two-fold higher tolerance to both molluscicides than did non-selected M-line snails.

beta-Thalassemia in Chinese: use of in vivo RNA analysis and oligonucleotide hybridization in systematic characterization of molecular defects

To perform a systematic analysis of beta-thalassemia genes among Chinese, we have determined the DNA haplotype in the beta-globin gene region of 37 Chinese beta-thalassemia chromosomes. Only four haplotypes were found. Blot hybridization analysis of erythroid RNA from patients homozygous for haplotypes 1, 2, and 3 demonstrated different patterns, suggesting that a different mutation was associated with each haplotype. The mutation associated with haplotype 1 was a C----T substitution at IVS-2, position 654. This mutation produces a new donor splice site and leads to formation of a beta-globin RNA with an insertion of 73 nucleotides. The mutation associated with haplotype 2 was a nucleotide insertion of A between codons 71 and 72, which results in a frameshift and premature termination of beta-globin synthesis. Haplotype analysis suggests that these two mutations may account for up to 85% of beta-thalassemia genes in this ethnic group. The haplotype 3 gene contained a transcriptional "TATA" box mutation that has been previously reported. Oligonucleotide hybridization demonstrated that the mutation associated with haplotype 4 was the same IVS-1 position 5 substitution commonly observed among beta-thalassemia genes in Asian Indians. Since haplotype 4 of Chinese differs at polymorphic sites on either side of the IVS-1 position 5 mutation from the haplotype associated with this mutation in Indians, the mutation presumably arose independently in these two populations.