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Biomedical subjects

J Kalinowski

Publications and source records attributed to J Kalinowski.

At least 73 records · Page 4Linked to original sources

Effect of frequency-altered feedback on stuttering frequency at normal and fast speech rates.

The purpose of this study was to determine the effect of the magnitude and direction of the frequency shift of frequency-altered auditory feedback (FAF) on stuttering frequency at both normal and fast speech rates. Twelve adult male and 2 adult female subjects who stutter read 10 different passages at either a normal or fast speech rate under nonaltered auditory feedback (NAF) and each of four FAF conditions in which the feedback signal was shifted: up one-half octave; up one octave; down one-half octave; and down one octave. Mean stuttering frequency for NAF was significantly higher than mean stuttering frequencies for all FAF conditions (p < 0.05). There were no statistically significant differences between the FAF conditions (p > 0.05). Subjects exhibited significantly more disfluencies under the fast speech rate condition relative to the normal speech rate condition. Future research should examine the relationship between frequency shifts of less than one-half octave and stuttering amelioration.

Adolescent↗

Increased fertility of Corynebacterium glutamicum recipients in intergeneric matings with Escherichia coli after stress exposure.

Corynebacterial recipient cells exposed to heat, organic solvents, pH shifts, or detergents show an increased fertility in subsequent interspecific matings with Escherichia coli. This effect is independent of de novo protein biosynthesis and seems to be due to a direct inactivation of a restriction system active against foreign DNA that enters the cell by IncP-mediated conjugation.

Conjugation, Genetic↗

Cloning and characterization of a DNA region encoding a stress-sensitive restriction system from Corynebacterium glutamicum ATCC 13032 and analysis of its role in intergeneric conjugation with Escherichia coli.

RP4-mediated transfer of mobilizable plasmids in intergeneric conjugation of Escherichia coli donors with Corynebacterium glutamicum ATCC 13032 is severely affected by a restriction system in the recipient that can be inactivated by a variety of exogenous stress factors. In this study a rapid test procedure based on intergeneric conjugal plasmid transfer that permitted the distinction between restriction-negative and restriction-positive C. glutamicum clones was developed. By using this procedure, clones of the restriction-deficient mutant strain C. glutamicum RM3 harboring a plasmid library of the wild-type chromosome were checked for their restriction properties. A complemented clone with a restriction-positive phenotype was isolated and found to contain a plasmid with a 7-kb insertion originating from the wild-type chromosome. This plasmid, termed pRES806, is able to complement the restriction-deficient phenotype of different C. glutamicum mutants. Sequence analysis revealed the presence of two open reading frames (orf1 and orf2) on the complementing DNA fragment. The region comprising orf1 and orf2 displayed a strikingly low G+C content and was present exclusively in C. glutamicum strains. Gene disruption experiments with the wild type proved that orf1 is essential for complementation, but inactivation of orf2 also resulted in a small but significant increase in fertility. These results were confirmed by infection assays with the bacteriophage CL31 from Corynebacterium lilium ATCC 15990.

Adaptation, Biological↗

[Nutritional evaluation of sweet potato cultivars Ipomea batata (L.) Lam used in bread as partial substitute of wheat flour].

Four hundred and forty entries of sweet potato tubers from the International Potato Center were evaluated for chemical characteristics related to nutritional value. Dry matter range in the group was 15 to 45g/100g. The native entries DLP 2393, DLP 1120, DLP 2312, DLP 1908 and the foreign RCB 361F were selected for use in bread manufacture. Their average dry matter and crude protein was 38.5 and 9.2% respectively. Sweet potato bread was made replacing 30% of wheat flour with grinded sweet potato tubers. This bread had 11.0% crude protein in dry matter basis which were the same for bread made of wheat flour. There were no differences in organoleptic characteristics or protein quality (Apparent biological value: 37 vs 42%; apparent digestibility: 81 vs 80%; net protein utilization: 33 vs 39%) between sweet potato or full wheat flour breads respectively.

Bread↗

Characterization of pGA1, a new plasmid from Corynebacterium glutamicum LP-6.

A new plasmid, pGA1, has been isolated from Corynebacterium glutamicum LP-6, and its detailed restriction map has been prepared. The 4.9-kb plasmid has a G + C content of 57%. It replicates in C. glutamicum ATCC13032 and is compatible with the three other plasmids, pCC1, pBL1 and pHM1519, commonly used for vector construction for amino acid-producing corynebacteria. Fusions of pGA1 with different Escherichia coli replicons (transferred from E. coli to Corynebacterium via transformation of spheroplasts or by filter mating experiments with intact cells) are shown to be suitable as shuttle plasmids; some of them are highly stable in C. glutamicum, even when propagated without any selection pressure.

Base Composition↗

Molecular analysis of the Corynebacterium glutamicum lysl gene involved in lysine uptake.

Two Corynebacterium glutamicum mutants defective in lysine uptake were identified by analysing mutants resistant to S-(2-aminoethyl)-cysteine (AEC). A 5.6 kb genomic DNA fragment restoring AEC sensitivity and lysine uptake was isolated. A 4.2 kb subfragment was sequenced and three open reading frames were identified. Subcloning and gene disruption experiments showed that only the first open reading frame, termed lysl, is involved in lysine uptake. Lysl consists of 501 amino acids with a Mr of 53600. The hydrophobicity profile suggests that the lysl gene product is an integral membrane protein with 13 transmembrane segments. The amino acid sequence of lysl displays strong homology to that of the arcD gene product of Pseudomonas aeruginosa, which is proposed to act as an arginine-ornithine antiporter. Investigation of the influence of the lysl gene on lysine secretion suggests the existence of a separate lysine efflux system in C. glutamicum.

Amino Acid Sequence↗

Genetic and biochemical analysis of the aspartokinase from Corynebacterium glutamicum.

The lysC/asd gene cluster of Corynebacterium glutamicum ATCC 13032 was cloned and sequenced. The lysC locus coding for aspartokinase consists of two in-frame overlapping genes, lysC alpha encoding a protein of 421 amino acids (Mr 44,300) and lysC beta encoding a protein of 172 amino acids (Mr 18,600). The C. glutamicum aspartokinase was purified and found to contain two proteins of Mr 47,000 and Mr 18,000. A C. glutamicum mutant expressing a feedback-resistant aspartokinase was shown to be changed in a single base pair of the lysC beta gene, leading to an amino acid exchange in the beta-subunit of the aspartokinase. In addition, the identified mutation was found to be responsible for the enhanced expression of the asd gene located downstream of lysC.

Amino Acid Sequence↗

A functionally split pathway for lysine synthesis in Corynebacterium glutamicium.

Three different pathways of D,L-diaminopimelate and L-lysine synthesis are known in procaryotes. Determinations of the corresponding enzyme activities in Escherichia coli, Bacillus subtilis, and Bacillus sphaericus verified the fact that in each of these bacteria only one of the possible pathways operates. However, in Corynebacterium glutamicum activities are present which allow in principle the use of the dehydrogenase variant and succinylase variant of lysine synthesis together. Applying gene-directed mutagenesis, various C. glutamicum strains were constructed with interrupted ddh gene. These mutants have an inactive dehydrogenase pathway but are still prototrophic, which is proof that the succinylase pathway of D,L-diaminopimelate synthesis can be utilized. In strains with an increased flow of precursors to D,L-diaminopimelate, however, the inactivation of the dehydrogenase pathway resulted in a reduced formation of lysine, with concomitant accumulation of N-succinyl-diaminopimelate in the cytosol up to a concentration of 25 mM. These data show (i) that both pathways can operate in C. glutamicum for D,L-diaminopimelate and L-lysine synthesis, (ii) that the dehydrogenase pathway is not essential, and (iii) that the dehydrogenase pathway is a prerequisite for handling an increased flow of metabolites to D,L-diaminopimelate.

Amino Acid Oxidoreductases↗

Metabolic activity of zinc during late pregnancy and lactation of first-litter gilts and their offspring under low dietary zinc intake.

The metabolism of Zn-65 was studied in littermate gilts fed either low-Zn (10 mg/kg) or Zn-supplemented (50 mg/kg) diets throughout pregnancy and lactation, and dosed with 100 microCi of Zn-65 at 100 days of pregnancy. Zinc-65 appeared earlier in urine of deficient gilts and about the same time after dose in feces of both groups. Total activity and proportion of the dose excreted via feces were higher in supplemented gilts, where as specific activity (SA) of feces was higher in deficient gilts. Excretion of endogenous Zn by supplemented gilts was triple that of deficient gilts whereas true absorption of Zn by deficient gilts was more than 4-fold that of their supplemented littermates. Biological half-life of Zn-65 was 46 d for the control and twice as long in deficient gilts. Total activity and SA of colostrum was higher in deficient gilts. Muscle, followed by liver, retained the highest proportion of the dose in both groups. Proportion of the dose retained in the liver and lungs was higher in control gilts where as Zn-65 retention in brain, heart, lungs and spleen was higher in deficient gilts. Most tissues from deficient gilts showed higher SA. Liver showed the highest Zn-65 concentration in control and lung in low-Zn newborn piglets. At two weeks of age, liver from both groups of piglets showed the highest Zn-65 retention. Proportion of the dose in brain and lungs was higher in deficient piglets. Specific activity of most organs from deficient piglets was higher than that of controls at both ages. Pregnant gilts under low dietary Zn intake made maximum utilization of this mineral by increasing true absorption and reducing endogenous excretion.

Absorption↗

Tissue composition and trace mineral content of the dam and litter under low dietary zinc intake during gestation and lactation of first-litter gilts.

Dry matter (DM), fat, calcium (Ca), phosphorus (P), zinc (Zn), copper (Cu), iron (Fe) and manganese (Mn) analyses were performed in tissues from gilts and their offspring after receiving either a control (50 mg/kg) or a low-Zn dietary (10 mg/kg) during gestation and lactation. DM and fat content in the body tissues of the dams were not affected by Zn-intake except in the liver and placenta; liver fat was significantly decreased, while placenta fat was significantly increased in the low-Zn gilts. Several tissues of the dams fed the low-Zn diet showed a lower Zn concentration, but liver and bones were the most significantly affected. Liver from these dams compensated with a significant increase in Cu concentration, while placenta, although not affected in its Zn concentration, showed a significant increase in Mn concentration. Overall, at the end of a two week lactation, first-litter gilts showed a significant reduction in total body Zn content, reaching only 65% of the total Zn found in the control gilts. This was compensated for by a significant increase in the total body Cu content, which was 24% greater than in the control group. In spite of the significant reduction of the total body Zn in the dams fed the low-Zn diet, their newborn and two week old piglets showed a significant reduction in Zn concentration in several tissues, of which the liver and bones were mostly affected. At the same time, liver Cu concentration was significantly increased in these piglets. Curiously, there was also observed a consistent increase in Mn concentration in the brain and bones of these piglets. Total body Zn was reduced by more than 40% in newborn piglets from low-Zn dams. There was a significant increase in total body Zn observed from birth to 2 weeks of age in piglets, 58.4 and 53.4 mg for the control and low-Zn group, respectively. This resulted in no significant differences between the 2 experimental groups at the end of 2 weeks of suckling by their respective dams. This indicated that the colostrum and milk was a good source of Zn regardless of the dietary Zn intake of their dams. Total body Cu in piglets at birth was not found to be significantly different in the 2 groups but, by 2 weeks of age, piglets being sucked by low-Zn dams showed a significantly higher Cu content, with an excess of 50% or more of the Cu content found in control piglets.

Adipose Tissue↗

Cleft palate fistulas: a multivariate statistical analysis of prevalence, etiology, and surgical management.

A retrospective, multivariate statistical analysis of 129 consecutive nonsyndromic patients undergoing cleft palate repair was performed to document the incidence of postoperative fistulas, to determine their cause, and to review methods of surgical management. Nasal-alveolar fistulas and/or anterior palatal fistulas that were intentionally not repaired were excluded from study. Cleft palate fistulas (CPFs) occurred in 30 of 129 patients (23 percent), although nearly a half were 1 to 2 mm in size. Extent of clefting, as estimated by the Veau classification, was significantly more severe in those patients who developed cleft palate fistula. Type of palate closure also influenced the frequency of cleft palate fistula. Forty-three percent of patients undergoing Wardill-type closures developed cleft palate fistula versus 10, 22, and 0 percent for Furlow, von Langenbeck, and Dorrance style closures, respectively. The fistula rate was similar in patients with (30 percent) and without (25 percent) intravelar veloplasty. Age at palate closure did not significantly affect the rate of fistulization; however, the surgeon performing the initial closure did not have an effect. Thirty-seven percent of patients developed recurrent cleft palate fistulas following initial fistula repair. Recurrence of cleft palate fistulas was not influenced by severity of cleft or type of original palate repair. Following end-stage management, a second cleft palate fistula recurrence occurred in 25 percent of patients. Continued open discussion of results of cleft palate repair is recommended.

Adolescent↗

Aspartokinase genes lysC alpha and lysC beta overlap and are adjacent to the aspartate beta-semialdehyde dehydrogenase gene asd in Corynebacterium glutamicum.

A 2.1 kb DNA fragment of the recombinant plasmid pCS2, isolated from an aminoethyl cysteine (AEC)-resistant and lysine-producing Corynebacterium glutamicum mutant strain, and which confers AEC resistance and lysine production on the wild-type G. glutamicum ATCC 13032 was analysed. DNA sequence analysis of this fragment revealed three large open reading frames (ORFs). The incomplete ORF1 does not contain the 5' end of the coding region. ORF2, which uses the same reading frame as ORF1, is identical to the 3' end of ORF1 and encodes a putative protein of 172 amino acids (aa) and of Mr 18,584. ORF3 encodes a putative protein of 344 aa and of Mr 36,275. The amino acid sequences deduced from ORF1 and ORF2 display strong homologies to those of the alpha- and beta-subunits of the Bacillus subtilis aspartokinase II. It is therefore proposed that the incomplete ORF1, termed lysC alpha, encodes part of the alpha-subunit of the C. glutamicum aspartokinase whereas the complete ORF2, termed lysC beta, encodes the beta-subunit of the same enzyme. ORF2 is responsible for AEC resistance and lysine production due to a feedback-resistant aspartokinase. The amino acid sequence deduced from ORF3, termed asd, is highly homologous to that of the Streptococcus mutans aspartate beta-semialdehyde dehydrogenase (ASD). Plasmids carrying the C. glutamicum asd gene complemented Escherichia coli asd mutants. Increase in ASD activity by a factor of 30-60 was measured for C. glutamicum cells harbouring high copy-number plasmids with the C. glutamicum asd gene.

Amino Acid Sequence↗

Cloning of a DNA fragment from Corynebacterium glutamicum conferring aminoethyl cysteine resistance and feedback resistance to aspartokinase.

The Corynebacterium glutamicum/Escherichia coli shuttle vector plasmid pZ1 was used to clone the S-(2-aminoethyl)-D,L-cysteine (AEC)-resistance gene from a lysine-excreting, AEC-resistant strain of C. glutamicum, the aspartokinase activity of which was released from feedback inhibition by mixtures of lysine and threonine or AEC and threonine respectively. A recombinant plasmid designated pCS2 carrying a 9.9-kb chromosomal insert that conferred AEC resistance and the ability to excrete lysine to its host was isolated. The aspartokinase activity of the pCS2-carrying strain was resistant towards inhibition by mixtures of lysine and threonine or AEC and threonine respectively. By deletion analysis the DNA region conferring AEC resistance to the host and feedback resistance to its aspartokinase activity could be confined to a 1.2-kb DNA fragment.

Aspartate Kinase↗

High-frequency conjugal plasmid transfer from gram-negative Escherichia coli to various gram-positive coryneform bacteria.

We report on the mobilization of shuttle plasmids from gram-negative Escherichia coli to gram-positive corynebacteria mediated by P-type transfer functions. Introduction of plasmids into corynebacteria was markedly enhanced after heat treatment of the recipient cells. High-frequency plasmid transfer was also observed when the restriction system of the recipient was mutated. On the basis of our data, we conclude that efficient DNA transfer from gram-negative to gram-positive bacteria, at least to coryneform bacteria, is conceivable in certain natural ecosystems.

Actinomycetales↗

Nitrogen and trace mineral balance of pregnant gilts under low dietary zinc intake.

Nitrogen (N) and mineral balance studies were carried out in littermate pregnant gilts fed either a zinc (Zn)-deficient basal diet (10 mg/Kg Zn) or a Zn-supplemented diet (50 mg/kg) from day 22 of pregnancy and in open gilts fed the Zn-supplemented diet. Collections were carried out at 60-66 and at 100-106 days of pregnancy. Open controls had N retention similar to that of Zn-restricted and Zn-supplemented gilts in early pregnancy. A trend towards better N utilization due to Zn supplementation was observed in late pregnancy. Pregnant, Zn-supplemented gilts were in negative Zn and copper (Cu) balance in early pregnancy, whereas open controls and Zn-restricted pregnant gilts were in positive Zn and Cu balance. Utilization of Zn and Cu tended to improve in late pregnancy with Zn-restricted gilts retaining somewhat more Zn and Cu than controls. In early pregnancy, Zn-supplemented gilts retained proportions of dietary iron (Fe) similar to that of open controls and twice the proportion retained by Zn-restricted gilts; the latter tended to increase Fe retention in late pregnancy, but Fe retentions by control gilts were still higher. Pregnant gilts were in negative manganese (Mn) balance in early pregnancy whereas open gilts were in positive balance. In late pregnancy both groups tended to improve their Mn economy, being close to Mn equilibrium. Positive Zn balance in Zn-restricted gilts was achieved by marked reduction of fecal Zn. The Zn-saving mechanisms appeared to influence Cu and Fe retention.

Animals↗

ISR1, a transposable DNA sequence resident in Rhizobium class IV strains, shows structural characteristics of classical insertion elements.

ISR1 is a small transposable element, identified in Rhizobium class IV strains by its high frequent mutagenic insertion into plasmid RP4. Hybridization studies showed that ISR1 is present in, multiple copies in Rhizobium class IV strains. Nucleotide sequence analysis revealed that ISR1 has a length of 1260 bp and is characterized by perfect inverted repeats of 13 nucleotides followed by a stretch of 28/29 nucleotides with imperfect homology. The insertion under study generated a target site duplication of 4 bp. ISR1 carries a large open reading frame, encoding a putative polypeptide of 278 amino acids (ORFA*), and three smaller ones in antiparallel direction (ORFs A1, A2, A3). Two of them are completely covered by the large open reading frame. No significant homology to 17 other known insertion sequence elements could be detected, either at nucleotide or at amino acid levels.

Bacteriocin Plasmids↗