The morphology and application of stem cells in digestive system surgery.

BACKGROUND: Stem cells constitute a group of cells which possess the ability to self-renew as well as the capacity to differentiate into a vast number of different cells within the human organism. Moreover, stem cells are able to undergo a potentially unlimited number of divisions and this characteristic is clinically essential. Specific fields of its application include treatment of diseases mainly in the field of haematology, orthopaedics, surgery, dentistry, and neurology. MATERIALS AND METHODS: In the following work, the current knowledge concerning mechanisms of stem cell treatment in different parts of the digestive system with its diseases as well as adjacent therapy for surgery has been revised. RESULTS: Stem cells therapy may be used in the treatment of various diseases of different parts of the digestive system. This also applies to the end part of the digestive tract (proctological diseases) because stem cells can be used to treat fistulas. Liposuction allows more recovery of mesenchymal stem cells, compared to previous bone marrow harvesting methods. Despite the application of stem cells in the treatment of different diseases used for many years so far, the therapeutic use for the regeneration of the gastrointestinal tract is still rare and unfamiliar. CONCLUSIONS: Regenerative medicine seems to be a promising tool in medical research, especially when insulated cells and designed biomaterials are taken into consideration. Major points of discussion include types of stem cells, their origin or differentiation for the treatment of many diseases.

Characterization and sequence analysis of the replicator region of the novel plasmid pALC1 from Paracoccus alcaliphilus.

The replicator region of a low-copy-number plasmid, pALC1, of Paracoccus alcaliphilus JCM 7364 was cloned in a form of the minireplicon pALC100 (3.6 kb). The host range of the minireplicon embraces several species of genus Paracoccus, as well as Agrobacterium tumefaciens, Rhizobium leguminosarum, and Rhodobacter sphaeroides (all belonging to alpha-Proteobacteria), but not Escherichia coli. The complete nucleotide sequence of the replicator region (2276 bp) revealed the presence of one complete open reading frame coding for the 28.4-kDa protein (RepA) with similarity to replication proteins of plasmid pSW500 of Erwinia stewartii and pVS1 of Pseudomonas fluorescens. The iteron-like region was identified upstream of the repA gene and consisted of two clusters of repeated sequences (17 bp long) separated by a putative DnaA box. Analysis of the predicted amino acid sequence of two adjacent incomplete ORFs suggests the localization of repA between genes involved in conjugation (traG) and partitioning (parA) within the pALC1 genome.

Changes in pancreatic lysosomal enzymes activity as the potential factors leading to diabetic enteropathy.

The aim of this study was to establish and quantify changes in the activities of total, free and bound fractions of pancreatic lipase, galactoso-6-sulphatase, beta-D-galactosidase and N-acetyl-beta-D-glucosaminidase in the course of alloxan-induced diabetes mellitus. Rabbits were divided into a control group and groups injected with alloxan on the 21st, 42nd, 90th and the 180th day, after which blood samples were taken and the rabbits sacrificed by decapitation. The pancreas was removed and the glucose level measured. Enzyme activities were assayed by spectrophotometric methods. The total activities of N-acetyl-beta-D-glucosaminidase and beta-D-galactosidase were the lowest on day 42 of the test, and the total activity of lipase was the highest at this point of time, as compared to the other periods of the study. We conclude that in the course of alloxan-induce diabetes activities of pancreatic lipase and sulphatase were increasing following the levels of glucose, whilst activities of beta-D-galactosidase and N-acetyl-beta-D-glucosaminidase were declining, being inversely correlated to the level of glucose and activities of the first two mentioned enzymes. Above alterations in activity of lysosomal pancreatic enzymes of alloxan induced diabetic rabbits may be responsible for some aspects of previously reported diabetic enteropathy and chronic complications, or may provide a mechanism for the pancreatic beta-cells to moderate their insulin content.

Plasmid occurrence and diversity in the genus Paracoccus.

The results of screening for the occurrence of plasmids in several strains representing 11 out of 13 species of the genus Paracoccus are presented. We show that plasmids (ranging in size from 2.7 to above 450 kb) are widely distributed in this genus. Only one tested strain (P. alkenifer) appears to be plasmid-free. The majority of the strains harbour at least two plasmids, one of which usually fits into the class of megaplasmids.

[Activity of malondialdehyde in rat plasma after H2 histamine receptor blockade]. / Zachowanie sie aldehydu malonowego w osoczu szczurów po blokadzie receptora histaminowego H2.

The study evaluates the effect of cimetidine (C), ranitidine (R) and famotidine (F) on the level of the plasma malondialdehyde (MDA). The tested drugs were given intraperitoneally to the male Wistar rats twice a day, during 6 weeks' period, in two doses. CI--2.85 mg/kg body weight (b.w.), R1--0.71 mg/kg b.w., F1--0.28 mg/kg b.w. The second doses (C2, R2, F2) were 10 times higher than C1, R1, F1. At the end of the 6th week of the experiment half of the animals were terminated. The remaining rats were kept for the next 6 weeks without any medications and were killed at the end of 12th week of the experiment. Blood was taken from still beating heart and centrifuged. The level of the MDA was determined from the plasma and compared to the 1 mg of the blood protein. None of administered H2 blockers changed the malondialdehyde level in serum of the experimental rats.

Construction of mobilizable cloning vectors derived from pBGS18 and their application for analysis of replicator region of a pTAV202 mini-derivative of Paracoccus versutus pTAV1 plasmid.

Two mobilizable cloning vectors, designated pABW1 and pAWB2, were constructed basing on the E. coli vector pBGS18 and oriT originating from RK2. In pABW2 the kanamycin resistance gene was replaced by a novel tetracycline resistance cassette derived from Tn1721. Both vectors, specific for E. coli, allow to perform the cloning steps in E. coli and then to efficiently transfer the constructs by conjugation to the host of choice. A vector which cannot propagate in the given host can be applied for identification of the host specific plasmid replicator regions. With the use of pABW2 we defined the minimal replicator region of pTAV202-a mini-derivative of the large pTAV1 plasmid of P. versutus. We also proved that RepC' encoded on this fragment is the principal initiator replication protein and that oriV is located along its coding sequence.

N-unsubstituted glucosamine residues and other modifications in murein of the obligatory chemolithotroph Thiobacillus neapolitanus.

Purified murein from Thiobacillus neapolitanus was poorly digested by lysozyme. It's sensitivity to the enzyme greatly increased after N-acetylation. The murein was found to contain 30 to 35% glucosamine residues lacking N-acetyl groups. It also contained phosphomuramic acid. Further modifications included amidation of diaminopimelic acid in the peptide side chains and a low alanine content. None of these modifications were found in the murein of another sulphur bacterium, Thiobacillus versutus.

The murein of Thiobacillus neapolitanus.

Amino acid analysis of pure murein isolated from cells of T. neapolitanus revealed the typical constituents of most mureins form Gram-negative bacteria. i.e. glutamic acid, alanine and diaminopimelic acid, but the molecular ratio ot these was unusual, being approximately 1: 1: 1. The reduced amount of alanine was explained by the absence of monomers containing tetrapeptide side chains, as revealed by h. p. 1. c. analysis, [(3)H]glutamic acid, [(3)H]diaminopimelic acid and [(3)H]N-acetylglucosamine were incorporated into the murein and allowed to determine the degree of its crosslinkage (28%) and the occurrence of turnover.

Characterization of the cell wall murein of Thiobacillus versutus.

Amino acid analysis of pure murein isolated from cells of Thiobacillus versutus grown in complex medium revealed the typical constituents of most mureins from gram-negative cells, i.e. muramic acid, glucosamine, glutamic acid, alanine and diaminopimelic acid in molecular ratio of 0.58: 0.79: 1.0: 1.76:1.07, respectively. The presence of glycine and leucine was also demonstrated (0.20 and 0.08 compared to glutamic acid). Glycine was also present in the murein of cells grown in chemically defined synthetic medium. The crosslinkage of T. versutus murein was approximately 36% --much higher than for most other gram-negative species. High pressure liquid chromatography analysis of muropeptide composition following muramidase digestion of T. versutus murein revealed essentially the same pattern as for Escherichia coli under similar conditions of digestion and separation with, however, some differences in the minor peaks.

Marriage and divorce in twentieth century American cohorts.

Marital status life tables have provided a basis for describing the marriage, divorce, and mortality experience of U.S. cohorts born 1888-1950. In brief, marriage occurred earlier and became more universal from the earliest cohorts to those of the late 1930s. More recent cohorts show declines in the proportion ever marrying and increases in the mean age at marriage. Period data for 1980 and cumulative cohort data by age suggest the likelihood of a continuing retreat from first marriage. Divorce has been rising steadily, with the latest cohorts indicating that 46 percent of male marriages and 42 percent of female marriages will end in divorce. Period data for males in 1980 raise the possibility that levels of divorce may have reached a peak, but cumulative cohort data by age show no such pattern. The present results are consistent with the view that a fundamental change in the traditional concept of marriage is underway. Traditional marriage involved the husband providing the wife with economic support and protection in return for her companionship and maternal services. Strong social pressures urged men and women to marry, and made the coveted services married persons provided each other difficult to obtain elsewhere. Recent economic changes have undermined the social and economic forces that maintained the institution of marriage. The U.S. economy has grown to include a large service sector in its labor force, and that growth has produced a dramatic increase in female labor force opportunities (Oppenheimer, 1970). The resultant large scale participation of women in economic activity blurs the traditional division of labor by sex, and goes to the very heart of the traditional marriage "bargain." At the same time, economic changes have weakened family ties by encouraging lower fertility, stressing achieved as opposed to ascribed characteristics, and fostering geographical mobility (Goode, 1970). The "marital union" of the past may be giving way to the "marital partnership" of the future, which will accommodate informal as well as formal marriages, less dependence between spouses, greater egalitarianism, lower fertility, and higher levels of divorce.

Penicillin-binding proteins of Thiobacillus versutus.

The cytoplasmic membrane of Thiobacillus versutus was found to contain at least nine penicillin-binding proteins (PBPs) with apparent molecular weights as judged by sodium dodecyl sulphate polyacrylamide slab gel electrophoresis of 87000 (PBP1), 81000 (PBP2), 68000 (PBP3), 63000 (PBP4), 57000 (PBP5), 40000 (PBP6), 37000 (PBP70, 33000 (PBP8) and 31000 (PBP9). The PBP pattern of T. versutus was thus quite different from that of the Enterobacteria and the Pseudomonads. Also the properties of the PBPs of T. versutus such as affinity for various beta-lactam antibiotics, heat stability and release of bound penicillin were different from similar properties of Escherichia coli, Pseudomonas aeruginosa and other gram-negative bacteria.

Cohort marriage and divorce in five Western countries.

An analysis of cohort trends in family formation and dissolution in five Western countries during the twentieth century is presented. The countries concerned are the United States, England and Wales, Belgium, Sweden, and Switzerland. "To obtain the indicators of family formation and dissolution used in this study, male and female cohort marital status life tables were constructed in each of the five countries for single year cohorts born between the years 1888 and 1945." Consideration is also given to the impact of changes in mortality. Data are from official sources. This is a revised version of a paper originally presented at the 1983 Annual Meeting of the Population Association of America (see Population Index, Vol. 49, No. 3, Fall 1983, pp. 384-5).

Twentieth-century cohort marriage and divorce in England and Wales.

Summary Marital status life tables, which follow a real or synthetic birth cohort through life and the marital statuses of 'never married', 'presently married', 'widowed', and 'divorced', reflect observed marriage, divorce and mortality behaviour and provide a detailed record of a cohort's experience. The present paper analyses such tables for cohorts of men and women born in England and Wales between 1900 and 1945. The results show that the later cohorts deviate substantially from the 'European pattern' of late marriage and high proportions never marrying, and that a dramatic rise in divorce has taken place, so that among the later cohorts one marriage out of four ends in divorce.

New types of Escherichia coli K-12 facultative recombination deficient mutants resistant to ultraviolet.

Numerous facultative temperature sensitive recombination deficient mutants of Escherichia coli K-12 strain 108 were isolated after mutagenization with nitrosoguanidine. The majority of the mutants were resistant to UV irradiation. Three mutants, KBP72, KBP169 and KBP610, with marked recombination deificiency (300 to 15,000 times) at 42 degrees C, were UV resistant; their sensitivity to mitomycin C was altered only slightly or not at all. Mutation KBP72 was co-transduced with ilv (83 unit on E. coli genetic map). The mutant is not able to form a functional recombinat structure. Two other mutations are located between 0 and 19 unit of the genetic map.

Kinetics of pair formation during cell cycle of Hfr and F in Escherichia coli K-12.

Pair formation ability in mating mixture of synchronized Hfr or F- culture and asynchronous culture of appropriate partner was studied. The obtained results allow to conclude that the pair formation ability of F- cells is stable over the whole cell cycle whereas in Hfr cells is it subject to cyclic changes with maximum in the first half of the cycle.

Host specificity of DNA in haemophilus influenzae: The physiological and genetical bases of instability of restriction and modification of DNA in strain Rd.

Further investigations of the instability of restriction and modification properties of H. influenzae Rd strain were carried out. It has been shown that the instable properties of hsd Hind1 system are maintained even after transfer of this system to another H. influenzae strain. The expression of hsd Hind1 system is very sensitive to various physiological changes which do not influence the other hsd systems present in the same Rd strain. The instability of hsd Hind1 system is postulated to be connected with some regulator gene(s).