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Biomedical subjects

R Marrero

Publications and source records attributed to R Marrero.

17 recordsLinked to original sources
PubMed2005

Long-term functional and urodynamic results of 50 patients receiving a modified sigmoid neobladder created with a short distal segment.

PURPOSE: We assessed the long-term functional and urodynamic outcomes of a modified sigmoid neobladder. MATERIALS AND METHODS: A total of 50 patients received a sigmoid neobladder with a short distal segment after radical cystoprostatectomy. Patients were followed at 3-month intervals the first year and every 6 months thereafter. Continence and voiding patterns were assessed using questionnaires and interview. The International Continence Society classification was used after 1996. Urodynamic assessment was performed 3 times during followup. RESULTS: Mean sigmoid segment length +/- SD was 18 cm (+/- 2.8). Mean followup was 38 months (+/- 24.8). Ureter stricture and reflux were present in 8% and 17% of the reimplanted units, respectively. Mean creatinine serum levels did not change after surgery and remained stable during followup. At 2 years 89% of the patients were continent in the daytime and 90% had good or satisfactory daytime continence according to the International Continence Society classification. At 3 years 77% of the patients voided every 3 or 4 hours during the day. Nighttime continence was poor. Only 10% of the patients complied with an alarm program. Mean maximal capacity of the reservoir was 300 ml and remained stable during followup. Mean intrareservoir pressure at maximal capacity decreased from 61 to 51 cm H2O from the first to the third urodynamic evaluation. No patient required clean intermittent catheterization. CONCLUSIONS: This modified sigmoid neobladder offers good daytime continence with low post-void residual and adequate daytime micturition frequency. Nighttime continence is poor. The presence of high intrareservoir pressures did not impair renal function.

Aged↗
PubMed2004

Transperitoneal laparoscopic radical prostatectomy: ascending technique.

BACKGROUND AND PURPOSE: To demonstrate the operative steps of transperitoneal laparoscopic radical prostatectomy with the ascending approach (Heilbronn technique). PATIENTS AND METHODS: The technique is based on our experience with more than 1000 cases of clinically localized prostate cancer from March 1999 to April 2004. The technical steps, instrumental requirements, patient data, complications, and reintervention rate were reviewed. RESULTS: The principles of the technique include the routine use of a voice-controlled robot (AESOP) for the camera, exposure of the prostatic apex with 120 degree retracting forceps, free-hand suturing for Santorini plexus control, application of 5-mm clips during the nerve-sparing technique, control of the prostatic pedicles by 12-mm Hem-o-Lock clips, the bladder neck-sparing technique in patients with stage T1c and T2a tumors, and use of interrupted sutures for the urethrovesical anastomosis. A considerable improvement was observed when comparing the first 300 with the most recent 300 cases (mean operating time 280 v 208 minutes; conversion rate 2.7% v 0.3%; reintervention rate 3.7% v 1.0%). CONCLUSIONS: Through our experience with more than 1000 cases, transperitoneal access for laparoscopic radical prostatectomy has proven to be feasible and transferable with results comparable to those of the original open approach. Besides the well-known advantages of minimally invasive surgery, the video endoscopic approach may offer further benefits in permitting optimization of the technique by video assessment.

Adult↗
PubMed1995

The transformation frequency of plasmids into Bacillus anthracis is affected by adenine methylation.

Plasmids pLTV1 and pHV33, capable of replicating in both Gram+ and Gram- bacterial hosts (shuttle vectors), when derived from the Escherichia coli strain HB101, were inactive in an electro-transformation assay employing the Bacillus anthracis strains delta Ames-1 and delta V1B-1 as recipients. The same plasmids isolated from the DNA methyltransferase (MTase)-deficient E. coli strain GM2929 (dam, dcm), were able to transform the B. anthracis strains at a frequency of 10(2)-10(3) transformants/micrograms of plasmid DNA. Efficient transformation was also obtained when the plasmids were propagated in strains of B. subtilis 168 (10(2)-10(4) transformants/micrograms of plasmid DNA). The B. subtilis strains used are known to harbor restriction/modification systems that recognize cytosine as a target for methylation. In contrast, no adenine methylation activities have been reported for these strains. The data presented indicate that DNA containing methylated adenine residues is restricted in the B. anthracis strains studied here, resulting in decreased plasmid DNA-mediated transformation frequencies. This inhibition could be alleviated by propagating plasmid species in MTase-deficient (dam) strains of E. coli or B. subtilis 168, before their introduction into strains of B. anthracis.

Bacillus anthracis↗
PubMed1995

Identification and characterization of a trans-activator involved in the regulation of encapsulation by Bacillus anthracis.

Production of the plasmid-pXO2-encoded capsule by Bacillus anthracis is required for full virulence of the organism. The induction of capsule synthesis in vitro requires growth in the presence of bicarbonate and CO2; however, little else is known about the regulation of capsule synthesis and the role it plays in the expression of virulence. Recently, transposon Tn917 mutagenesis of B. anthracis plasmid pXO2 identified genes involved in capsule production and genes associated with virulence in inbred mice. One mutant, UUP5, had an 8.2-kb deletion located outside of the capsule structural gene region (cap). UUP5 was reduced significantly in capsule production and in virulence as compared to the wild-type (wt) parental strain. Using a HindIII-generated pXO2 library, we examined fragments contained in the deleted region and showed that electroporation of the mutant with a cloned 2.3-kb HindIII fragment restored capsule production to wt levels. Sequence analysis of the 2.3-kb fragment revealed a 1449-bp open reading frame (ORF) encoding a 483-amino-acid (57 kDa) protein, in good agreement with the 55-kDa protein detected by in vitro transcription/translation. Construction of a frameshift mutant that replaced the 55-kDa protein with a truncated 34-kDa moiety abrogated the complementing activity of the fragment in UUP5. mRNAs specific for cap and for the 1449-bp ORF were detected in mutant UUP5 transformed with the unaltered fragment and grown in the presence of bicarbonate, but not in air. No cap-specific mRNA, and very low levels of ORF-specific mRNA, were detected in UUP5 containing the frameshift mutation.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1993

Surgical management of advanced squamous cell skin cancers.

Squamous cell cancer of the skin usually follows prolonged exposure to known carcinogens including ultraviolet light, ionizing radiation, chronic infection or irritation, chemicals, and immunologic suppression. The majority of squamous cell skin cancers metastasize infrequently and can be cured with aggressive wide local excision. However, on occasion they can be quite aggressive locally, with or without associated distant metastasis, and may require a radical surgical approach. We report a series of four male patients covering the spectrum of this disease with the following distribution: lower pole of the right ear, right posterior thigh below gluteal fold with positive inguinal nodes, lateral aspect of the foot with bone involvement, and as an incidental finding in a pilonidal cyst. We conclude that one should not hesitate to proceed with aggressive surgical resection as it may provide the only chance for cure. Finally, one should always look for lymph node metastasis, particularly with large (> 5 cm) lesions adjacent to a regional lymph node drainage basin.

Aged↗
PubMed1988

Cloning of the Bacillus subtilis recE+ gene and functional expression of recE+ in B. subtilis.

By use of the Bacillus subtilis bacteriophage cloning vehicle phi 105J23, B. subtilis chromosomal MboI fragments have been cloned that alleviate the pleiotropic effects of the recE4 mutation. The recombinant bacteriophages phi 105Rec phi 1 (3.85-kilobase insert) and phi 105Rec phi 4 (3.3-kilobase insert) both conferred on the recE4 strain YB1015 resistance to ethylmethane sulfonate, methylmethane sulfonate, mitomycin C, and UV irradiation comparable with the resistance observed in recE+ strains. While strain YB1015 (recE4) and its derivatives lysogenized with bacteriophage phi 105J23 were not transformed to prototrophy by B. subtilis chromosomal DNA, strain YB1015 lysogenized with either phi 105Rec phi 1 or phi 105Rec phi 4 was susceptible to transformation with homologous B. subtilis chromosomal DNA. The heteroimmune prophages phi 105 and SPO2 were essentially uninducible in strain YB1015. Significantly, both recombinant prophages phi 105Rec phi 1 and phi 105Rec phi 4 were fully inducible and allowed the spontaneous and mitomycin C-dependent induction of a coresident SPO2 prophage in a recE4 host. The presence of the recombinant prophages also restored the ability of din genes to be induced in strains carrying the recE4 mutation. Finally, both recombinant bacteriophages elaborated a mitomycin C-inducible, 45-kilodalton protein that was immunoreactive with Escherichia coli recA+ gene product antibodies. Collectively, these data demonstrate that the recE+ gene has been cloned and that this gene elaborates the 45-kilodalton protein that is involved in SOB induction and homologous recombination.

Bacillus subtilis↗
PubMed1986

Evidence for circular permutation of the prophage genome of Bacillus subtilis bacteriophage phi 105.

Analysis of DNA extracted from Bacillus subtilis lysogenic for bacteriophage phi 105 was performed by restriction endonuclease digestion and Southern hybridization using mature phi 105 DNA as a probe. The data revealed that the phi 105 prophage is circularly permuted. Digests using the enzymes EcoRI, SmaI, PstI, and HindIII localized the bacteriophage attachment site (att) to a region 63.4 to 65.7% from the left end of the mature bacteriophage genome. The phi 105 att site-containing SmaI C, PstI J, and HindIII L fragments were not present in digests of phi 105 prophage DNA. phi 105-homologous "junction" fragments were visualized by probing digests of prophage DNA with the purified PstI J fragment isolated from the mature bacteriophage genome. The excision of the phi 105 prophage was detected by observing the appearance of the mature PstI J fragment and the concomitant disappearance of a junction fragment during the course of prophage induction.

Bacillus subtilis↗
PubMed1985

Bacteriophage SPO2-mediated plasmid transduction in transpositional mutagenesis within the genus Bacillus.

A single copy of the Streptococcus faecalis transposon Tn917, located in the Bacillus subtilis chromosome, was able to transpose onto the SPO2 cos plasmid pPL1017, which codes for chloramphenicol resistance and contains the bacteriophage phi 105 immunity region. Selection for pPL1017::Tn917 chimeras was performed by SPO2-mediated plasmid transduction of transposon-borne resistance to macrolide-lincosamide-streptogramin B antibiotics (MLSr). The transposition of Tn917 onto plasmid pPL1017 occurred with a frequency of 10(-5) and was dependent on the presence of a subinhibitory dose of erythromycin. Twelve chimeras were subjected to genetic and physical analyses. Two Cams transductants harbored plasmids whose chloramphenicol acetyltransferase genes had been insertionally inactivated by Tn917. Several transpositions in the vicinity of the phi 105 immunity region were detected. However, all of the 300 MLSr, Camr transductants screened were immune to phi 105 infectious activity. One pPL1017::Tn917 chimera, pLK200, was transferred by SPO2 plasmid transduction into the Bacillus amyloliquefaciens prototrophic strain DSM7. Plasmid pLK200 was effective in the mutagenesis of the DSM7 chromosome and yielded auxotrophs at a frequency of 0.5 to 5.3%. Generation of auxotrophs was also dependent on the presence of a subinhibitory dose of erythromycin. Forty-four auxotrophs representing at least nine amino acid requirements were recovered.

Acetyltransferases↗
PubMed1984

Characterization of interspecific plasmid transfer mediated by Bacillus subtilis temperate bacteriophage SP02.

Plasmid pPL1010 is a 7.0-kilobase derivative of plasmid pUB110 that harbors the cohesive end site of the bacteriophage SP02 genome. Plasmid pPL1017 is a 6.8-kilobase derivative of plasmid pC194 that contains the immunity region of bacteriophage phi 105 and the cohesive end site of bacteriophage SP02. These plasmids are transducible by bacteriophage SP02 at a frequency of 10(-2) transductants per PFU among mutant derivatives of Bacillus subtilis 168 and have been transferred to other strains of B. subtilis and B. amyloliquefaciens by means of bacteriophage SP02-mediated transduction, with frequencies ranging from 10(-5) to 10(-7) transductants per PFU. The introduced plasmids were stably maintained in nearly all new hosts in the absence of selective pressure. An exception was found in B. subtilis DSM704, which also harbored three cryptic plasmids. Plasmids pPL1010 and pPL1017 were incompatible with a 7.9-kilobase replicon native to strain DSM704. Furthermore, plasmid pPL1017 was processed by strain DSM704 into a approximately 5.3-kilobase replicon that was compatible with the resident plasmid content of strain DSM704. The use of bacteriophage SP02-mediated plasmid transduction has allowed the identification of Bacillus strains that are susceptible to bacteriophage SP02-mediated genetic transfer but cannot support bacteriophage SP02 lytic infection.

Bacillus↗
PubMed1982

Interference of plasmid pCM194 with lysogeny of bacteriophage SP02 in Bacillus subtilis.

Three observations indicated that the 2-megadalton chloramphenicol resistance plasmid pCM194 interferes with SP02 lysogeny of Bacillus subtilis. SP02 plaques formed on B. subtilis(pCM194) appeared almost clear, whereas plaques produced on plasmid-free or pUB110-containing cells contained large turbid centers. The number of phages spontaneously liberated by B. subtilis(SP02) was increased 10-fold or more when pCM194 was also present in the lysogens. Lastly, growth of B. subtilis(SP02, pCM194) for approximately 20 to 25 generations resulted in essentially complete loss of the prophage. This interference was not observed with pUB110 or pE194, and the pCM194 interference was not directed against B. subtilis temperate phage phi 105, which is unrelated to SP02. Lytic replication of SP02 appeared to be unaffected by pCM194. pCM194 interference with SP02 lysogeny was demonstrable in recombination-proficient strains and a recE mutant of B. subtilis. SP02 prophage which were noninducible due to the phage ind mutation were resistant to pCM194 interference. pCM194 interference was lost when the entire pCM194 molecule was joined at its unique HpaII site or at one of the two MboI sites to pUB110 or pUB110 derivatives. pBR322 joined to pCM194 at the same MboI site or at the HindIII site produced chimeras that retained the ability to interfere with SP02 lysogeny. A three-part plasmid constructed by joining pBR322 to pCM194 (at HindIII sites) and to pE194 (at PstI sites) was compatible with the SP02 prophage and showed a temperature-sensitive replication phenotype characteristic of the pE194 replicon. One explanation for the interference involves competition for a host component between an SP02 genome attempting to establish lysogeny and plasmids whose replication is directed by the pCM194 replicon.

Bacillus subtilis↗
PubMed1981

SP02 particles mediating transduction of a plasmid containing SP02 cohesive ends.

SP02 particles that mediate transduction of plasmid pPL1010, a 4.6-megadalton derivative of pUB110 containing an Eco RI endonuclease-generated fragment of SP02 deoxyribonucleic acid that spans the cohesive ends, exhibit three unusual features: the transducing particles have a lower buoyant density than infectious particles; the transduction of pPL1010 occurs at high efficiency; and the transducing activity of the particles is relatively resistant to ultraviolet irradiation when the recipient is recombination proficient. Evidence is presented which indicates that SP02(pPL1010) particles carry the plasmid predominantly as a linear multimer having a molecular mass comparable to that of infectious SP02 deoxyribonucleic acid (ca. 31 megadaltons). The plasmid monomers in the linear multimer appear oriented in the same polarity. The buoyant density difference between infectious and transducing particles appears to be due mainly to the buoyant density difference between pPL1010 (1.699 g/cm3) and SP02 deoxyribonucleic acid (1.702 gm/cm3).

Bacillus subtilis↗
PubMed1981

High-frequency elimination of SP02 prophage from Bacillus subtilis by plasmid transformation.

Transformation of competent Bacillus subtilis lysogenic for SP02 with any of three plasmids (pCM194, pUB110, pAM77) generates drug-resistant transformants of which 5 to 20% have lost the infectivity and immunity associated with the SP02 prophage. Such cured derivatives can be again lysogenized with SP02 and again cured by introduction of a different plasmid. Elimination of the SP02 prophage was not detected when plasmids were introduced by PBS1 transduction or by transformation of protoplasts. Similarly, transformants of B. subtilis selected for chromosome markers retained the prophage. The phi 105 prophage was not eliminated from competent B. subtilis transformed with plasmids.

Anti-Bacterial Agents↗
PubMed1980

Transductional selection of cloned bacteriophage phi 105 and SP02 deoxyribonucleic acids in Bacillus subtilis.

The Bacillus subtilis temperate bacteriophages phi 105 and SP02 are incapable of transduction of the small, multicopy drug resistance plasmids pUB110 and pCM194. Cloning endonuclease-generated fragments of phi 105 or SP02 DNA into each of the plasmids renders the chimeric derivatives susceptible to transduction specifically by the phage whose deoxyribonucleic acid is present in the chimera. The majority of phage deoxyribonucleic acid fragments identified that render plasmids transducible by phi 105 or SP02 appear to be internal fragments, not fragments containing the cohesive ends. However, the highest overall transduction frequency was observed in SP02-mediated transduction of a derivative of pUB110 containing a 1.6-megadalton EcoRI fragment that likely contains the SP02 cohesive ends (plasmid pPL1010). The transducing activity present in a phi 105 transducing lysate had a buoyant density slightly greater than infectious particles, whereas the majority of transducing particles in an SP02(pPL1010) transducing lysate had a buoyant density slightly less than infectious particles. Although no detectable change in plasmid structure resulted from transduction by phi 105 or SP02, deoxyribonucleic acid isolated from a purified SP02(pPL1010) transducing lysate contained no detectable monomeric pPL1010, but did contain a form of pPL1010 of higher molecular weight than the monomer.

Bacillus subtilis↗
PubMed1979

Insertional inactivation of trpC in cloned Bacillus trp segments: evidence for a polar effect on trpF.

Plasmid pUB110 was previously used as a vector to clone fragments of deoxyribonucleic acid that complement the trpC2 mutation in Bacillus subtilis from endonuclease EcoRI digested B. licheniformis, B. pumilus, and B. subtilis cellular deoxyribonucleic acid. Each of several such trp plasmids was subsequently shown to contain a segment of the trp gene cluster on the basis of genetic complementing activity. In the present study, analysis of the Trp enzyme levels in B. subtilis harboring the constructed trp plasmids confirms the genetic constitution of the plasmids. Thus, plasmids that complement mutations in specific trp genes specify the corresponding enzyme activities. The levels of the plasmid-specified Trp enzymes in B. subtilis were generally above the repressed level of the chromosomally specified Trp enzymes and equal to or below the derepressed levels of the chromosomally specified Trp enzymes. Certain cloned trp segments contain a single HindIII-sensitive site. Insertion of HindIII-generated deoxyribonucleic acid fragments into these trp plasmids resulted in inactivation of trpC complementing activity, loss of the trpC-specified enzyme activity, and a 10-fold reduction in the specific activity of the plasmid-specified trpF product. The HindIII insertions had no detectable effect on the level of the trpD product, nor did the insertions detectably alter plasmid-specified complementing activity other than to abolish trpC complementation. Removal of the HindIII insertions was accompanied by recovery of trpC complementing activity and restoration of the trpC-and trpF-determined enzymes to the levels specified by the parent plasmids.

Bacillus↗