Sympathovagal balance fluctuates during colonoscopy

BACKGROUND AND STUDY AIM

Colonoscopy is a common gastroenterological procedure for investigation of the bowel. The main side effects of colonoscopy are pain during investigation, cardiovascular complications and very rarely even death. The aim of this study was to compare the continuous fluctuation of heart rate variability (HRV) components during colonoscopy under normal conditions, analgesia/sedation, and total intravenous anesthesia.

PATIENTS AND METHODS

37 consecutive patients (aged 35 - 65), were randomly allocated to three groups: no sedation (control group 1); analgesia/sedation (group 2); and total intravenous anesthesia (group 3). Holter electrocardiography and subsequent frequency domain analysis were undertaken. The low-frequency (LF, 0.04 - 0.15 Hz) and the high-frequency (HF, 0.15 - 0.40 Hz) components were estimated using spectral analysis in the usual way. Normalized units (nu) were calculated from the following equations: LFnu = LF/(LF + HF), and HFnu = HF/(LF + HF).

RESULTS

Groups 2 and 3 were found to have a significantly lower HFnu and higher LFnu than group 1 essentially throughout the procedure. A one-way analysis of variance and t-test confirmed that the differences were significant when the colonoscope reached the splenic flexure as were the LF/HF balances at the splenic and hepatic flexures and the cecum. The percentage change in LF/HF was also analyzed, and it was found that in group 3 the mean change was over 136 % when the colonoscope reached the sigmoid flexure, which was significantly higher than in the other two groups.

CONCLUSION

Most changes in HRV components occurred during colonoscopy of the left side of the bowel. Analgesia/sedation and total intravenous anesthesia increased HRV by increasing the LF component.

[Psychological and sociologic requirements to prepare for anesthesia and surgery of patients with intracranial invasive processes]

Response to anxiety has been analyzed in 195 patients operated because of intracranial expansive process and influence of standard and individualized preoperative preparations over it.

[Anesthesia-related and surgical problems in day neurosurgery in children]

Problems resulted from necessity of securing safety for 4500 children with intracranial congenital hydrocephalus and subdural hygromas diagnosed and operated in one-day neurosurgery terms.

Arthromitus (Bacillus cereus) symbionts in the cockroach Blaberus giganteus: dietary influences on bacterial development and population density

The filamentous spore-forming bacterium Arthromitus, discovered in termites, millipedes, sow bugs and other soil-dwelling arthropods by Leidy (1850), is the intestinal stage of Bacillus cereus. We extend the range of Arthromitus habitats to include the hindgut of Blaberus giganteus, the large tropical American cockroach. The occurrence and morphology of the intestinal form of the bacillus were compared in individual cockroaches (n=24) placed on four different diet regimes: diurnally maintained insects fed (1) dog food, (2) soy protein only, (3)purified cellulose only, and (4) a dog food-fed group maintained in continuous darkness. Food quality exerted strong influence on population densities and developmental stages of the filamentous bacterium and on fecal pellet composition. The most dramatic rise in Arthromitus populations, defined as the spore-forming filament intestinal stage, occurred in adult cockroaches kept in the dark on a dog food diet. Limited intake of cellulose or protein alone reduced both the frequency of Arthromitus filaments and the rate of weight gain of the insects. Spores isolated from termites, sow bugs, cockroaches and moths, grown on various hard surfaces display a branching mobility and resistance to antibiotics characteristic to group I Bacilli whose members include B. cereus, B. circulans, B. alvei and B. macerans. DNA isolated from pure cultures of these bacilli taken from the guts of Blaberus giganteus (cockroach), Junonia coenia (moth), Porcellio scaber (sow bug) and Cryptotermes brevis (termite) and subjected to Southern hybridization with a 23S-5S B. subtilis ribosomal sequence probe verified that they are indistinguishable from laboratory strains of Bacillus cereus.

Variation in 16S-23S rRNA intergenic spacer regions among Bacillus subtilis 168 isolates

The genome of the Bacillus subtilis 168-type strain contains 10 ribosomal RNA (rRNA) operons. In the intergenic spacer region (ISR) between the 16S and 23S rRNA genes, five rRNA operons, rrnI-H-G and rrnJ-W, lack a trinucleotide signature region. Precise determination of molecular weight (MW), using electrospray mass spectrometry (MS), of the polymerase chain reaction (PCR) products from a segment of the ISR from the 168-type strain and B. subtilis 168-like strain 23071 demonstrated 114 and 111 basepair (bp) PCR products (due to the presence or absence of the insert in the operons) as predicted from sequence. However, PCR of the ISR segment for five other B. subtilis 168 isolates generated only a 114 bp PCR product, suggesting the presence of the trinucleotide signature region in all rRNA operons for these strains. Additional genetic variability between the seven B. subtilis 168 isolates was demonstrated by restriction fragment length polymorphism (RFLP) of the rRNA operons, with three distinct patterns found upon Southern blot analysis. The 168-type strain and three others (23066, 23067, and 23071) exhibited the same Southern pattern. Thus, operon deletion is not responsible for the absence of a 111 bp product on MS analysis for strains 23066 and 23067. Restriction analysis confirmed the presence of the trinucleotide signature region in the ISR of all rRNA operons for five B. subtilis 168 isolates; sequencing of rrnW/H from a representative strain also upheld this finding. These results help provide a better understanding of variations in sequence, operon number and chromosomal organization, both within a genome and among isolates of B. subtilis subgroup 168. It is also hypothesized that the presence of the trinucleotide insert in certain rRNA operons may play a role in rRNA maturation and protein synthesis.

Classification and genetic characterization of pattern-forming Bacilli

One of the more natural but less commonly studied forms of colonial bacterial growth is pattern formation. This type of growth is characterized by bacterial populations behaving in an organized manner to generate readily identifiable geometric and predictable morphologies on solid and semi-solid surfaces. In our first attempt to study the molecular basis of pattern formation in Bacillus subtilis, we stumbled upon an enigma: some strains used to describe pattern formation in B. subtilis did not have the phenotypic or genotypic characteristics of B. subtilis. In this report, we show that these strains are actually not B. subtilis, but belong to a different class of Bacilli, group I. We show further that commonly used laboratory strains of B. subtilis can co-exist as mixed cultures with group I Bacilli, and that the latter go unnoticed when grown on frequently used laboratory substrates. However, when B. subtilis is grown under more stringent semiarid conditions, members of group I emerge in the form of complex patterns. When B. subtilis is grown under less stringent and more motile conditions, B. subtilis forms its own pattern, and members of group I remain unnoticed. These findings have led us to revise some of the mechanistic and evolutionary hypotheses that have been proposed to explain pattern growth in Bacilli.

A relA(S) suppressor mutant allele of Bacillus subtilis which maps to relA and responds only to carbon limitation

The histidine analog 3-amino-1,2,4-triazole (AT) was used for the selection of spontaneous AT-resistant revertants of a relA mutant of Bacillus subtilis. One of these revertants, L3, showed a unique phenotype; it did not respond to amino acid starvation, like the relA mutant, but it did respond to glucose starvation by the accumulation of (p)ppGpp, unlike its parent. Genetic analysis revealed that this suppressor mutant (relA(S)) allele mapped to the relA locus at 239 degrees on the B. subtilis chromosome.

Two tRNA gene clusters associated with rRNA operons rrnD and rrnE in Bacillus subtilis

Sequence analysis of cloned rescued DNA fragments from a Bacillus subtilis strain with an inserted recombinant plasmid in ribosomal operon rrnE revealed the presence of two tRNA genes for Met and Asp at the 3' end of the operon. Probing chromosomal DNA from a strain carrying a plasmid inserted in rrnD with a fragment containing the genetically unassigned cluster of 16 tRNA genes revealed that the cluster is located immediately following the rrnD operon. Our findings show that all 10 rrn operons in B. subtilis are associated with tRNA gene clusters.

Early spo gene expression in Bacillus subtilis: the role of interrelated signal transduction systems

The early spo genes are subject to a number of different control mechanisms. We found that at least one histidine kinase, SpoIIJ, is important for the expression of early spo genes but that two others, ComP and DegS, also affect sporulation, especially when SpoIIJ is absent. This indicates the existence of a signal transduction network which may gather information from several sources to feed into the sporulation pathway. Early spo gene expression is inhibited by overproduction of two response regulators, SpoOF and ComA. This effect is eliminated by the elevated presence of their cognate histidine kinases, SpoIIJ and ComP, respectively. This suggests that the unphosphorylated response regulators cause the inhibition of sporulation.

Genetic structure and DNA sequences at junctions involved in the rearrangements of Bacillus subtilis strains carrying the trpE26 mutation

Studies on the region upstream to ribosomal operon rrnD of Bacillus subtilis led to the characterization of two of the four chromosomal junctions involved in the rearrangements (a translocation and an inversion) of the strains carrying the trpE26 mutation. Genetic analysis, by integrative mapping, showed linkage of rrnD to cysB and hisA (both on segment A) in the trpE26-type strains. Physical analysis showed that the region upstream to rrnD is now linked to the trpE-ilvA chromosome segment as demonstrated by analyzing restriction site-polymorphism between 168 and trpE26-type strains. Similar experiments confirmed the previous genetic data on linkage in these areas in strains carrying novel rearrangements derived from the trpE26-type strains: stable merodiploids and inversions. The nucleotide sequence of the area 5' to rrnD in both types of strains (168 and trpE26), the region downstream of the citG gene and the region carrying the trpE26 mutation (made available to us by D. Henner) provided evidence for the molecular basis of the differences in structure, allowed the identification of the break points and revealed the presence of a polypurine region upstream to rrnD as seen in other systems in B. subtilis. No extensive homology was found between pairs of junctions so far sequenced. The models proposed by C. Anagnostopoulos for the role of DNA sequences of intrachromosomal homology involved in the transfer of the trpE26 mutation and the formation of novel arrangements require therefore reevaluation.

The structure of the trpE, trpD and 5' trpC genes of Bacillus pumilus

The nucleotide (nt) sequences of the Bacillus pumilus trpE, trpD and 5' portions of trpC genes have been determined. Genetic analysis suggested the presence of an internal promoter upstream from the trpC gene, yet no typical consensus sequences were found. The nt and amino acid sequence homologies between the B. pumilus, Bacillus subtilis and Escherichia coli trp genes are presented.

Chromosomal organization of rRNA operons in Bacillus subtilis

Integrative mapping with vectors containing ribosomal DNA sequences were used to complete the mapping of the 10 rRNA gene sets in the endospore forming bacterium Bacillus subtilis. Southern hybridizations allowed the assignment of nine operons to distinct BclI restriction fragments and their genetic locus identified by transductional crosses. Nine of the ten rRNA gene sets are located between 0 and 70 degrees on the genomic map. In the region surrounding cysA14, two sets of closely spaced tandem clusters are present. The first (rrnJ and rrnW) is located between purA16 and cysA14 closely linked to the latter; the second (rrnI, rrnH and rrnG) previously mapped within this area is located between attSPO2 and glpT6. The operons at or near the origin of replication (rrnO,rrnA and rrnJ,rrnW) represent "hot spots" of plasmid insertion.

Instability of rRNA operons in Bacillus subtilis

Many laboratory strains of Bacillus subtilis contain 9 rather than 10 rRNA operons due to deletions occurring within the rrnJ-rrnW or rrnI-rrnH-rrnG gene cluster. These operons are members of two sets of closely spaced clusters located in the cysA-aroI region. Analysis of rescued DNA from integrants with insertions into rrnG and rrnH indicated that these tandemly arranged operons allowed frequent deletions of an rrn operon equivalent. These events may arise spontaneously by intrachromosomal recombination or by simultaneous double crossovers with a multimeric integrative plasmid.

Mapping of rRNA genes with integrable plasmids in Bacillus subtilis

Integrable plasmids pGR102 and pWR103 containing ribosomal sequences from within the transcriptional units for 16S and 23S were used to transform Bacillus subtilis. To date, these plasmids integrated into 7 of 10 known rrn operons. Two such events occurred at unassigned operons, revealing a close linkage of the CAT gene of the plasmid to pha-1 situated between dal-1 and purB33 for rrnE and to thiA78 situated between glyB133 and re-12 for rrnD. All seven integration events that led to the loss of unique ribosomal BclI fragments can now be assigned to known rrn operons.

Alterations in the number of rRNA operons within the Bacillus subtilis genome

Deletions and additions of rRNA gene sets in Bacillus subtilis were observed by Southern hybridizations using cloned radiolabeled rDNA sequences. Of the ten rRNA gene sets found in B. subtilis 168M or NCTC3610, one was deleted in strains possessing the leuB1, ilvC1, argA2 and pheA1 mutations. Among EcoRI restriction fragments of genomic DNA products, a 2.9-kb 23S rRNA homolog was missing. In HindIII digest, both 5.5- and 5.1-kb hybrid bands were lost with 16S and 23S probes, respectively. Similarly, genomic DNAs digested with SmaI showed the absence of both 2.1- and 2.0-kb fragments that hybridized to 16S and 5S sequences, respectively, in wild-type genomes. In contrast, B. subtilis strain 166 and its derivatives displayed a gain of a 3.3-kb HindIII fragment homologous to 16S rRNA. Transforming the ilvC1 and leuB1 mutations into new genetic backgrounds revealed in some clones the concomitant introduction of the ribosomal defect. Transformations with the slightly heterologous donor DNA from strain W23 yielded some Leu+ and Arg+ transformants with altered hybridization patterns when probed with cloned sequences. We propose that the deletion of the rRNA operon occurred in the ilv-leu gene cluster of the B. subtilis genome as a result of unequal recombination between redundant sequences.

Genetic and nucleotide sequence homologies in bacillus genomes

The extent of divergence in the organization of the aromatic amino acid cluster among the heterogenetic strains of Bacillus subtilis has been examined by hybridizations to a trp homolog from B. pumilus and by marker survivals after restriction. The trp operon in the W23, 3610 and 168M genomes exhibit variations in the location of the ECoRI and HindIII cleavage sites consistent with the relative transforming activity of the surviving genes and the history of the strains.

Mutagenesis during transformation of Bacillus subtilis. I. An increase in "selfing' resulting from hybrid donor DNAs

Reverse mutations increase when competent Bacillus subtilis cells are transformed with high concentrations of homologous "selfer' DNA. A high proportion of the mutants were also transformants of linked genes. A stimulation in the appearance of reversed mutations occurred when homoduplex and heteroduplex "selfer' DNAs were used as donors. Digestions of native and hybrid DNAs with nuclease S1 from Aspergillus oryzae resulted in the preferential decrease of mutations as compared to a much smaller inactivation of single marker transformation. Among various repair-deficient strains of B. subtilis, only poly A mutants showed a preferential effect of either suppressing or stimulating the frequency of reverse mutation induced by "selfer' DNA. The results are consistent with mutagenic errors occurring during gap-filling steps in the process of either mismatch repair or recombinational strand exchanges.

Mutagenesis during transformation of Bacillus subtilis. II. An increase in chemically-induced mutations during competency

During the development of competency in Bacillus subtilis there was an increased sensitivity to methyl methanesulfonate (MMS) treatments. The frequency of reverse mutation also increased among the MMS-revertible markers by a factor of 100 as compared to vegetative cultures. The frequency of 2-aminopurine(AP)-induced mutagenesis was the same in competent and noncompetent cultures. Studies with DNA-polymerase-deficient mutants showed a direct involvement of DNA polymerase I in promoting MMS and transformation-induced mutagenesis in competent cells.

Intrastrand self-complementary sequences in Bacillus subtilis DNA

Intrastrand self-complementary sequences have been isolated from the DNA of Bacillus subtilis by hydroxyapatite (HA) chromatography following thermal renaturation of strands separated by chromatography on methylated albumin kieselguhr (MAK). The instrastrand structures derived from the MAK H strand (HA HII) were biologically active showing transforming activity for a wide variety of markers, as well as hybridization to both pulse-labelled and ribosomal RNA. Removal of regions of single-strand DNA with S1 nuclease did not significantly alter the biological activity of the self-annealed molecules. The overall efficiency of transformation and hybridization of the intrastrand self-annealing DNA was low suggesting that many sequences in the population are neither active in transformation to prototrophy nor transcribed into RNA.

Transformation in Bacillus subtilis with nitrogen mustard crosslinked DNA. Effect on cotransformation and mutation frequencies

Bacillus subtilis DNA was treated in vitro with nitrogen mustard and the crosslinked molecules were purified, after alkali denaturation, by hydroxyapatite chromatography. When tested for the ability to transform the trpC2-hisB2 segment, these molecules exhibited a decrease in the cotransformation index (r) as compared to native or renatured DNA. The decrease in r was not accompanied by an increase in mutagenicity.

Asymmetric transcription during post-germinative development of Bacillus subtilis spores. II. Hybrid competition analyses

Hybrid-competition analyses were done to estimate the relatedness of 3H-labeled mRNA species synthesized during spore germination and log-phase growth. The competitions showed that early in the germination process 10--15 and 1--3% of the RNA transcribed from the H and from the L strand, respectively, were unique and absent during log-phase growth. At later stages, the amounts of the germination-specific H transcripts decreased more rapidly than the L transcripts. The competitions with pulse-labeled log-phase RNAs showed that vegetative genes were transcribed more rapidly from the H strand than from the L strand. Most of the results could be correlated with the observed decrease in the H/L asymmetry ration during spore germination.

Asymmetric transcription during post-germinative development of Bacillus subtilis spores

The relative transcription from L and H strands of Bacillus subtilis DNA during consecutive stages of spore outgrowth was determined and compared to the transcription pattern during log-phase growth of vegetative cells. Pulses of [3H] uridine were administered during early, middle and late outgrowth phases of germination and the RNAs isolated. The asymmetry ratio of H/L as determined by hybridization at saturating RNA/DNA inputs showed a gradual decrease. During the period studied (10-90 and 90-160 min post-induction), about 50 and 35%, respectively, of the radioactive RNA consisted of ribosomal RNA transcripts. The decrease in the H/L asymmetry ratio was due predominantly to the appearance and accumulation of L strand transcripts and not to either changes in the quantity of H strand transcripts nor to fluctuation in the rate of rRNA synthesis.

Chromatographically fractionated complementary strands of Bacillus subtilis deoxyribonucleic acid: biological properties

Biological, physical, and chromatographic properties of methylated albuminkieselguhr (MAK)-fractionated complementary strands, designated as light (L) and heavy (H), of Bacillus subtilis deoxyribonucleic acid (DNA) are presented. The pattern of transforming activity along the MAK elution profile of alkilidenatured DNA shows that the residually active molecules selectively fractionated ahead of the L strand fraction, whereas the most active self-annealed molecules fractionated preferentially at the trailing end of the H strand fraction. The restoration rate of transforming activity in the late-eluting H molecules was rapid and independent of concentration during the annealing reaction. The data suggest that the self-annealing activity in the H strand is due in part to the formation of intrastrand secondary structures. Hydroxyapatite chromatography of self-annealed L and H strands yielded a major fraction (I) of highly purified strand preparations devoid of transforming activity and hypochromicity, and a minor "nativelike" fraction (II). Sedimentation velocity measurements show that, in addition to the mutual complementary nature of the L and H fractions, they differ in molecular size and possibly configuration.

Chromatographically fractionated complementary strands of Bacillus subtilis deoxyribonucleic acid: transformation of hybrids

The annealing properties as measured by the restoration of transforming activity and hypochromicity of methylated albumin-kieselguhr (MAK)-fractionated complementary strands of Bacillus subtilis deoxyribonucleic acid (DNA) are presented. Temperature-absorbance measurements performed on annealed mixtures of various L and H strand fractions indicated the existence of a complementarity gradient between the two MAK peaks. The markers purA16, leu-8, metB(5), thr-5, and the linked marker hisB(2)-try-2 exhibited different bimodal distributions on MAK columns. The transforming efficiency of heteroduplex mixtures, prepared by cross-annealing resolved complementary strands of wild-type and recipient DNA, was compared. The transforming efficiency of the wild-type L and H strands was equal in one preparation and unequal in a second preparation. It was found that in the second strand preparation the heteroduplex DNA containing the H strand from wild type was more efficient for all of the markers tested. The variations in transforming efficiencies of the complementary strands in heteroduplex molecules reported here and by others are due in part to strands of unequal length and probably to the self-annealing property of the H strands. At present, no conclusion could be made regarding the existence of strand selection bias during integration of donor DNA in competent B. subtilis cells.

Distribution of pyrimidine oligonucleotides in strands L and H of Bacillus subtilis DNA

The distribution of pyrimidine oligodeoxynucleotide clusters in L and H strands of Bacillus subtilis DNA separated by methylated albumin-Kieselguhr has been determined. Preparations of native and single-stranded DNA were degraded with diphenylamine in formic acid, and the released isostichs with the general formula of Py(n)P(n+1) were separated on DEAE-cellulose by chain length. Eleven isostichs were obtained for strands L and H in unequal proportions. Each isostich fraction was subfractionated by base composition on DEAE-cellulose at pH 3.0. 61 Pyrimidine oligonucleotide clusters were separated from the H strand and only 46 from the L strand. The findings show a higher degree of asymmetry between the strands in the distribution of cytosine-rich clusters as compared with thymine-rich clusters. The longest cytosine oligodeoxynucleotide present in both strands is of chain length 5. There is an unusually high distribution of thymine oligodeoxynucleotides of length 5-11. Up to chain length 6, the distribution of thymine oligodeoxynucleotides between the strands is about equal; from chain length 7 to 11 they occur predominantly in the H strand.

Asymmetric template function of microbial deoxyribonucleic acids: transcription of messenger ribonucleic acid

In Bacillus subtilis and Escherichia coli, pulse-labeled ribonucleic acid (RNA) synthesized during step-down growth hybridized preferentially with the heavy (H) strand of methylated albumin-Kieselguhr-fractionated deoxyribonucleic acid (DNA). At high RNA inputs, the ratio of RNA hybridized with the H strand to that hybridized with the light (L) strand was 8.7 for B. subtilis and 2.0 for E. coli. At high DNA inputs, the H/L hybridization ratio increased by a factor of two. This change in the hybridization ratio was attributable to the fraction of the pulse-labeled RNA which is in stable RNA components. The hybridization peak of pulse-labeled RNA was specifically located in the late-eluting region of the absorbance profile of the H strand. This region was considered to represent the most actively transcribing H strand templates.

Asymmetric template function of microbial deoxyribonucleic acids: transcription of ribosomal and soluble ribonucleic acids

In Bacillus subtilis and Escherichia coli, 16 and 23S ribosomal ribonucleic acid (rRNA) hybridize exclusively with the heavy (H) strand of methylated albuminkieselguhr (MAK)-fractionated complementary deoxyribonucleic acid (DNA) strands. All the soluble RNA (4S RNA) in B. subtilis and 66 to 75% of the 4S RNA in E. coli also hybridize with the H strand. Interspecific hybridization shows that E. coli 23S rRNA also binds selectively to the DNA H strand of Salmonella typhimurium. The hybridization peak for all three cellular RNA components is specifically located in the late-eluting region of the absorbance profile of the DNA H strand. The early-eluting region of the light (L) strand preferentially inhibits the hybridization between the peak region of the H strand and 23S rRNA. These regions are considered to represent the transcribing sequences and their complements for 23S rRNA in the separated H and L strands of DNA, respectively.

Template properties of complementary fractions of denatured microbial deoxyribonucleic acids

DNA preparations from seven bacterial species and from E. coli phage T4, and also the complementary L and H fractions into which these DNA specimens, after denaturation, were separated by chromatography on methylated albumin-kieselguhr columns, were studied as templates in the RNA polymerase system, and the nucleotide composition of the RNA products was determined. The RNA transcripts of the separated L and H fractions were found to be faithful copies of the respective DNA fractions. This suggests "transcription analysis" as a sensitive and reliable analytical technique for the determination of the base composition of denatured DNA. The L and H fractions of T4 DNA were shown, both by temperature-absorbance profiles and by transcription analysis, to be mutually complementary. The RNA products formed with intact DNA as the template were not exact copies of the latter; their composition indicated that under our experimental conditions the "heavy" DNA strand is transcribed preferentially.

Separation of microbial deoxyribonucleic acids into complementary strands

DNA preparations from seven bacterial species and from the E. coli phage T4 can, after denaturation with alkali, be separated chromatographically into two distinct components (L and H) through intermittent gradient elution from methylated albumin kieselguhr columns. The direct chemical analysis of the L and H fractions isolated from DNA specimens of the AT type shows them to exhibit a high degree of complementarity; but despite a bias in the distribution of purines and pyrimidines, either fraction contains equimolar quantities of 6-amino and of 6-keto nucleotides. In the L and H components derived from DNA of the equimolar and GC types, the distribution bias appears limited to guanine and cytosine. It is suggested that the L and H fractions represent the complementary DNA strands.