Angiotensin II-producing proteases from granulomatous tissue reaction in mice infected with Schistosoma mansoni

1. Angiotensin I hydrolases, Mr 140,000 and Mr 70,000 were separated by gel filtration from Tris-HCl buffer extract of hepatic granulomas developed in mice with schistosomiasis. Two enzymes had different substrate specificity. 2. Mr 140,000 hydrolase activity was inhibited by captopril as reported for angiotensin converting enzyme (ACE), while that of Mr 70,000 hydrolase activity was inhibited by potato carboxypeptidase inhibitor. 3. An intermediary, des-Leu10-angiotensin I and then angiotensin II were formed from angiotensin I by Mr 70,000 hydrolase. 4. The findings suggest that Mr 70,000 enzyme is tissue carboxypeptidase A, and it generates angiotensin II in granulomatous inflammation as does ACE.     

The ethmoid and presphenoid of cetaceans

A cribriform plate, a perpendicular plate, and two lateral masses are major components of the ethmoid bone of mammals. Notwithstanding the noticeable bone, virtually sitting in the center of the skull, extensive modifications of the skull of modern cetaceans, especially odontocetes (toothed whales), and the lack of clarity as to what characteristics delimit each element of the ethmoid has made the problem of the nature of the cetacean ethmoid more complicated and elusive than in other, less modified mammals. Furthermore, contention as to whether a perpendicular plate of the ethmoid, or the mesethmoid, exists in all mammals including cetaceans has remained unsettled. In odontocetes, the mesethmoid has been variably identified not only as the osseous nasal septum but also as the mediodorsal region of the posterior wall of the nasal passage below the nasals, as a mass of bone encased by the vomer in front of the osseous nasal cavity at the base of the rostrum, and as a combination of some portions mentioned above. The presence or absence of the mesethmoid in various groups of mammals has attracted the attention of some biologists, and here, I demonstrate that cetaceans have no mesethmoid. The close inspection of the ontogenetic changes of the basicranial elements in cetaceans reveals that a mass of bone ensheathed by the vomer in front, or at the level of the osseous nasal cavity is actually the presphenoid. It is highly likely that in odontocetes the posterior wall of the nasal passages below the nasals consists of the combination of the frontal, the imperforated cribriform plate, the paired ectethmoids, and the vomer, the latter three of which partially concealing the presphenoid dorsally and laterally as the ontogeny proceeds. In contrast, mysticetes clearly display ethmoturbinates and a cribriform plate, which are morphologically similar to those in terrestrial mammals. J. Morphol. 277:1661–1674, 2016. © 2016 Wiley Periodicals, Inc.     

Characterisation of Trypanosoma cruzi populations by dna polymorphism of the cruzipain gene detected by single-stranded dna conformation polymorphism (SSCP) and direct sequencing

Fifty fresh isolates of Trypanosoma cruzi from Triatoma dimidiata vectors and 31 from patients with Chagas disease were analysed for DNA polymorphisms within the 432-bp core region of the cruzipain gene which encodes the active site of cathepsin L-like cystein proteinase. The cruzipain gene showed signs of polymorphism consisting of four different DNA sequences in Central and South American isolates of T. cruzi. The PCR fragments of Guatemalan isolates could be divided into three groups, Groups 1, 2 and 3, based on different patterns of single-stranded DNA conformation polymorphism. All of the strains isolated from Brazil, Chile, and Paraguay, except for the CL strain, showed a Group 4 pattern. Two to four isolates from each group were analysed by cloning and sequencing. A silent mutation occurred between Groups 1 and 2, and five nucleotides and two aa substitutions were detected between Groups 1 and 3. The DNA sequence of Group 4 contained five nucleotides and one aa substitution from Group 1. All of the DNA sequences corresponded well with the single-stranded DNA conformation polymorphism. The Group 1 isolates, the majority in the Guatemalan population (70/81, 86.4%), were isolated from both triatomines and humans, but Group 3 were isolated only from humans. Moreover, the Group 2 isolates were detected only in triatomine vectors (9/50; 18%), but never in humans (0/32, P<0.05) suggesting that this group has an independent life-cycle in sylvatic animals and is maintained by reservoir hosts other than humans.     

Epitope analysis of lipid A preparations from Pseudomonas diminuta and Pseudomonas vesicularis

Abstract In vitro antigenic reactivity of lipid A from Pseudomonas diminuta and Pseudomonas vesicularis with homologous and heterologous lipid A antibodies including monoclonal antibodies was studied by inhibition test of enzyme-linked immunosorbent assay (ELISA). The results suggest that both Pseudomonas lipid As have very similar epitopes, including species-specific and cross-reactive epitopes as compared with enterobacterial lipid A.     

Transport of p-aminohippuric acid, uric acid and glucose in highly purified rabbit renal brush border membranes.

A procedure for preparing highly purified brush border membranes from rabbit kidney cortex using differential and density gradient centrifugation is described. Brush border membranes prepared by this procedure were substantially free of basal-lateral membranes, mitochondria, endoplasmic reticulum and nuclear material as evidenced by an enrichment factor of less than 0.3 for (Na+ + K+)-ATPase, succinate dehydrogenase, NADPH-cytochrome c reductase and DNA. Alkaline phosphatase was enriched ten fold indicating that the membranes were enriched at least 30 fold with respect to other cellular organelles. The yield of brush border membranes was 20%. Transport of D-glucose by the membranes was identical to that previously reported except that the Arrhenius plot for temperature dependence of transport was curvilinear (EA = 11.3--37.6 kcal/mol) rather than biphasic. Transport of p-aminohippuric acid and uric acid were increased by the presence of NaCl, either gradient or preequilibrated. However, no overshoot was obtained in the presence of a NaCl gradient, and KCl and LiCl also produced equivalent stimulation of transport suggesting a nonspecific ionic strength effect. Uptakes of p-aminohippuric acid and uric acid were not saturable, and were increased markedly by reducing the pH from 7.5 to 5.6. Probenecid (1 mM) reduced p-aminohippuric acid and uric acid (50 muM) uptake by 49% and 21%, respectively. We conclude that the uptake of uric acid and p-aminohippuric acid by renal brush border membranes of the rabbit occurs primarily by a simple solubility-diffusion mechanism.     

Differentiation of quail myoblasts transformed with a temperature sensitive mutant of Rous sarcoma virus. I. Relationship between differentiation and tyrosine kinase of src gene product.

Quail embryonic pectoral myoblasts fuse with each other at 35.5 degrees C and 41 degrees C to essentially equal extents. When the myoblasts were transformed with a temperature-sensitive mutant of Rous sarcoma virus (ts-RSV), their fusion and biochemical processes of differentiation became temperature-sensitive: their fusion occurred at 41 degrees C, the non-permissive temperature, but not at 35.5 degrees C, the permissive temperature, suggesting that the fusion was regulated by the viral transforming gene. Fusion of the transformed cells proceeded more rapidly and synchronously than that of the parent cells at 41 degrees C, and was completely suppressed at the permissive temperature, unlike that of the parent cells. These transformed cells were used to examine the relationship between myogenic differentiation and the tyrosine kinase activity of the src gene product. In spite of the temperature sensitivity of transformation, results showed that expressions of the src gene at 35.5 degrees C and 41 degrees C were similar. However, the level of tyrosine-phosphorylated protein was decreased at 41 degrees C. Moreover, myoblast fusion could occur at 35.5 degrees C in the presence of herbimycin A, an inhibitor of the tyrosine kinase activity of the src gene product. These results indicate that the tyrosine kinase activity of the src gene product is closely associated with regulation of myogenic differentiation of the cells.     

Improved immobilization of DNA to microwell plates for DNA-DNA hybridization.

An improved and simplified protocol for DNA immobilization was developed to enhance DNA-DNA hybridization on microwell plates. Target DNA was immobilized by simple dry-adsorption. Efficiencies of DNA immobilization and retention were enhanced 1.4-6.5 times and 4.2-19.6 times, respectively, compared with a conventional method. The overall hybridization efficiency was increased 3.1-5.2 times. This simple new protocol can reduce the consumption of scarce DNA samples.     

A unique system for regulating mitochondrial mRNA poly(A) status and stability in plants

Poly(A) status is the major determinant of mRNA stability, even in endosymbiotic organelles. Poly(A) specific ribonuclease (PARN) is distributed widely among eukaryotes and has been shown to regulate the poly(A) status of cytoplasmic mRNA in various organisms. Surprisingly, our recent study revealed that PARN also directly regulates poly(A) status of mitochondrial mRNA in Arabidopsis. In this addendum, we discuss whether this mitochondrial function of PARN is common in plants and why PARN has been assigned such a unique function.