Stereoregulating behaviour of organoalkali and organoalkaline earth compounds in polymerization of methyl methacrylate

Stereoregulating behaviour of organoalkali and organoalkaline earth metal compounds in methyl methacrylate (MMA) polymerization has been studied. Low temperature and polar solvents such as tetrahydrofuran (THF) favour formation of syndiotactic polymer when lithium and magnesium ketyls are used as catalysts. Whereas isotactic polymer is obtained with sodium ketyl even in THF at ?70°C. Lithium aluminum hydride (LiAlH₄) gave almost complete isotactic polymer in high conversion in diethyl ether or toluene even at low temperature, and lithium aluminum tetraethyl (LiAlEt₄), on the other hand, gave very highly syndiotactic polymer under the same conditions. The solvent, besides, showed very important role in stereoregulation, that is, LiAlH₄ could give syndiotactic polymer in a polar solvent at low temperature. Polymer structure was analyzed by NMR- and IR-spectroscopy. The electrical conductivities of these catalyst systems were measured and there was found a parallelism between those values and stereoregularities of polymers obtained by the respective catalyst systems.     

Identity of hemolysins produced by Vibrio cholerae non-O1 and V. cholerae O1, biotype El Tor.

Hemolysins purified from non-O1 Vibrio cholerae (non-O1 hemolysin) and a Vibrio cholerae O1, biotype El Tor (El Tor hemolysin) were investigated for their homology. The hemolysins were isolated from the culture supernatant fluids by ammonium sulfate precipitation and gel filtration on Sephadex G-100 columns. The purified hemolysins gave single bands with an identical mobility on conventional polyacrylamide gel disc electrophoresis. The molecular weights of the non-O1 and El Tor hemolysins were estimated to be about 60,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and the amino acid compositions of the hemolysins were very similar. The specific activities of the hemolysins were identical, and both hemolysins were neutralized to the same extent with antisera against the homologous and heterologous hemolysins. Ouchterlony double immunodiffusion tests with both hemolysins and antihemolysin serum gave a common (fused) precipitin line. These data indicate that the non-O1 hemolysin is biologically, physicochemically, and immunologically indistinguishable from the El Tor hemolysin.     

CHEMOTACTIC ACTIVITY FOR POLYMORPHONUCLEAR AND MONONUCLEAR LEUKOCYTES IN RHEUMATOID SYNOVIAL FLUIDS

In order to why polymorphonuclear leukocytes (PMNs) are predominant and mononuclear leukocytes (MNLs) are few in rheumatoid synovial fluids, chemotactic factor(s) for PMNs and MNLs were studied in the synovial fluids of rheumatoid arthritis (RA-SF) and osteoarthritis (OA-SF) using both Boyden's and agarose methods. The RA-SF showed strong chemotactic activity for human peripheral blood PMNs compared with non-rheumatoid OA-SF. The chemotactic activity for PMNs was well correlated with the number of PMNs in RA-SF, suggesting that it was a natural mediator for PMN emigration into rheumatoid joint cavity. The major chemotactic factor for PMN in RA-SF was of apparent molecular weight of 14,000 and its activity was suppressed to less than 10 percent by anti-C5a antibody, but it failed to show any anaphylatoxin activity which was an attribute of C5a. It was, therefore, suggested to be C5a-like molecule but not C5a itself. The possibility that the factor may be a C5a des-Arg was discussed. On the contrary, the chemotactic activity for MNLs was not found neither in RA-SF nor OA-SF. These findings may explain the fact that PMNs are predominant in rheumatoid synovial fluids.     

Outcome of advanced renal cell carcinoma arising in end-stage renal disease: comparison with sporadic renal cell carcinoma

Clinical and Experimental Nephrology - The data regarding oncological outcome in advanced renal cell carcinoma (RCC) arising in end-stage renal disease (ESRD) are limited. Patients diagnosed with...     

Longitudinal assessment of anti-Müllerian hormone after cesarean section and influence of bilateral salpingectomy on ovarian reserve

ObjectiveThis study aimed to compare longitudinal changes in ovarian reserve markers after cesarean section (CS) with and without bilateral salpingectomy (BS).Study designWe prospectively enrolled women >35 weeks’ gestation scheduled for CS alone or CS + BS and obtained blood samples for anti-Müllerian hormone prior to surgery and at 3 and 6 months after surgery. At the 3-month visit, we similarly performed transvaginal ultrasound for antral follicle count.ResultsWe enrolled 50 women; 30 underwent CS only and 20 underwent CS + BS. Although anti-Müllerian hormone level increased over 6 months of follow-up in both groups, no clinically important differences in the geometric mean (interquartile range) (ng/mL) were observed at any timepoint (baseline [0.69 {0.36?1.21} {CS only} vs 0.49 {0.32?2.10} {CS + BS}, p = 0.64]; 3 months [1.35 {0.58?3.13} vs 1.45 {1.04?2.25}, p = 0.79]; and 6 months [1.74 {0.93?4.45} vs 2.60 {1.41?5.10}, p =0.27]). Similarly, we detected no difference in antral follicle count.ConclusionBS at the time of CS does not have a negative impact on ovarian reserve 6 months after surgery.ImplicationWhile our results provide reassuring data that bilateral salpingectomy for permanent contraception at the time of cesarean section does not impact ovarian reserve, longer adequately powered studies are needed.     

Quantitative analysis of distribution and fate of human lung cancer emboli labeled with 125I-5-iodo-2′-deoxyuridine in nude mice

The chemical and radio toxicity of ¹²⁵-5-iodo-2-deoxyuridine (¹²⁵IUDR) on 870127T human lung cancer (HLC) cells grown in tissue cultures and the quantitative analysis of the distribution and fate of ¹²⁵IUDR-labeled 870127T HLC cells in nude mice were evaluated. After 870127T HLC cells were plated and ¹²⁵IUDR was added to the dishes at levels ranging from 0.1 µCi/ml to 5.0 µCi/ml of media, the growth rate of the cells for 24h was similar to that of non-labeled cells. Nude mice were given intravenous injections of ¹²⁵IUDR labeled 870127T HLC cells and killed at various intervals ranging from 5 min to 24 h after injection. Organs were collected, processed, and monitored. The lung contained most of the tumor cells at all intervals and the number of tumor cells in the lung decreased gradually post-injection. The tumor cells died rapidly, and only about 1.5% of all cell survived after 24 h post-injection. This study confirmed that very few surviving tumor cells are needed to cause metastasis.     

Congener-specific data on polychlorinated biphenyls in tissues of common porpoise from Puck Bay,Baltic Sea

Individual congeners of polychlorinated biphenyls (PCBs), including the highly toxic non-ortho coplanar 3,3,4,4-tetrachlorobiphenyl (IUPAC No. 77), 3,3,4,4,5-pentachlorobiphenyl (IUPAC No. 126), and 3,3,4,4,5,5-hexachlorobiphenyl (IUPAC No. 169), and their mono- and di-ortho analogs, have been identified and quantified in the blubber, liver, and muscles of three female common porpoise Phocoena phocoena collected from the Puck Bay (inner Gulf of Gdask, Poland) in 1989–1990, to elucidate actual concentrations and toxic potential. The total 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalent for 13 coplanar PCBs in blubber was 1,500±470 pg/g wet wt. 2,3,4,4,5-Pentachlorobiphenyl (IUPAC No. 118) was the most contributing individual and occupied between 57 and 67% in total toxic equivalent of coplanar PCBs in blubber, while 2,2,4,4,5,5-hexachlorobiphenyl (IUPAC No. 153), 2,3,3,4,4-pentachlorobiphenyl (IUPAC No. 105) and 2,2,3,4,4,5-hexachlorobiphenyl (IUPAC No. 138) comprised between 9.5–14, 7.6–11.5, and 7.2–11.0%, respectively (totally 82–95%), and 2,3,3,4,4,5-hexachlorobiphenyl (IUPAC No. 156) was absent. A potentially most toxic non-ortho PCB members such as 3,3,4,4,5-pentachlorobiphenyl, 3,3,4,4,5,5-hexachlorobiphenyl and 3,3,4,4-tetrachlorobiphenyl were only minor contributors, altogether occupying between 1.0 and 14.5% in total TEQ of coplanar PCBs. Concentrations of total PCBs in lipids of the blubber ranged from 26 to 47 g/g and were comparable or lower than reported earlier for common porpoises from the Baltic Sea, North Sea, and North Atlantic by other authors.