Twelve hours exposure to inhomogeneous high magnetic field after logarithmic growth phase is sufficient for drastic suppression of Escherichia coli death.

When Escherichia coli B was aerobically grown at 43 degrees C in a medium whose concentration was one-fourth that of the Luria-Bertani (LB) medium supplemented with 1.5 g/l of glutamic acid, drastic cell death was observed after the end of the logarithmic growth phase. However, when the same experiment was conducted under inhomogeneous 5.2-6.1 T magnetic field, cell death was extremely suppressed and the ratio of viable cell number under high magnetic field to that under geomagnetic field reached as much as 100,000. When the magnetic field exposure was restricted to 12 h after the logarithmic growth phase, a similar high degree of suppressive effect on the death was observed. The findings that the amount of sigma S protein encoded by the rpoS gene under the high magnetic field was larger than that under the geomagnetic field, and that the magnetic field effect disappeared when the rpoS gene-deficient strain was cultivated under the high magnetic field, suggest the interaction of magnetic field with a stationary phase specific gene.

Drastic high magnetic field effect on suppression of Escherichia coli death.

When Escherichia coli B was aerobically grown in a medium containing one-fourth the concentration of the LB medium supplemented with glutamic acid at 43 degrees C under an inhomogeneous 5.2-6.1 T magnetic field, the number of cells in the stationary phase under the high magnetic field was 100,000 times higher than that under a geomagnetic field. The finding that the amount of sigma S factor encoded by the rpoS gene under the high magnetic field was larger than that under the control geomagnetic field indicated that the activity of the rpoS gene was affected by the high magnetic field.

Disappearance of growth advantage in stationary phase (GASP) phenomenon under a high magnetic field.

The phenomenon called growth advantage in stationary phase (GASP) originally discovered by Kolter et al. was confirmed using two bacterial strains, Escherichia coli ZK126Nalr and ZK126Smr, under the geomagnetic field. However, when the same experiment was conducted in an inhomogeneous high magnetic field of 5.2-6.1 T, almost no death of ZK126Smr was observed and the GASP phenomenon disappeared. When the same experiment was conducted in a homogeneous magnetic field of 7 T, the GASP was significantly delayed due to the much slower death rate of ZK126Smr than that in the geomagnetic field. These data are consistent with our previous finding that a high magnetic field reduces the death rate of bacteria and enhances their survivability in a stationary phase.

The genes degQ, pps, and lpa-8 (sfp) are responsible for conversion of Bacillus subtilis 168 to plipastatin production.

Bacillus subtilis YB8 produces the lipopeptide antibiotic plipastatin. B. subtilis MI113, which is a derivative of strain 168, was converted into a new plipastatin producer, strain 406, by competence transformation with the chromosomal DNA of YB8. Transposon mini-Tn10 insertional mutagenesis was applied to strain 406, which revealed that lpa-8 (sfp) (encoding 4'-phosphopantetheinyl transferase) and the pps operon (located between 167 and 171 degrees ) are essential for plipastatin production. The pps operon was previously suggested to encode putative peptide synthetases (A. Tognoni, E. Franchi, C. Magistrelli, E. Colombo, P. Cosmina, and G. Grandi, Microbiology 141:645-648, 1995) and was thought to be the fengycin operon (V. Tosato, A. M. Albertini, M. Zotti, S. Sonda, and C. V. Bruschi, Microbiology 143:3443-3450, 1997). We claim that the pps operon is the pli operon, encoding plipastatin synthetase. By using a new high-performance liquid chromatography system, we revealed that strain 168 expressing only lpa-8 can also produce plipastatin, although the yield is very low. However, the introduction of the pleiotropic regulator degQ of strain YB8 into strain 168 expressing lpa-8 resulted in a 10-fold increase in the production of plipastatin.

High magnetic field enhances stationary phase-specific transcription activity of Escherichia coli.

When Escherichia coli B was aerobically grown at 37 degrees C under inhomogeneous 5.2-6.1 Tesla (T) magnetic fields in the superconducting magnet biosystem (SBS), the cell number in the stationary phase after the growth had leveled off, was about 3 times higher than that under a geomagnetic field. When the E. coli defective in the rpoS gene which encodes a sigma factor, sigmaS of RNA polymerase and is specifically expressed in the stationary phase was cultivated at 37 degrees C in SBS, such enhancement of cell survival was significantly reduced. The E. coli cells carrying rpoS-lacZ fusion gene or other rpoS dependent genes fused with lacZ were grown, significant increase in the activity of beta-galactosidase was observed in the stationary phase under high magnetic field. These data suggest that enhancement of the transcription activity in stationary phase is involved in the higher survival of the cells under magnetic field.

Bone SPECT in cholesteatoma assessment.

Bone SPECT in cholesteatoma assessment. Single photon emission computed tomography (SPECT) is a procedure in nuclear medicine which enables bone lesions to be better assessed. Twenty patients with cholesteatoma were studied to assess the efficiency of SPECT in bone lesions produced by cholesteatoma. Every patient also had a middle ear computed tomography (CT) and underwent surgery and anatomopathologic examination. Results obtained by SPECT are compared to CT results. SPECT was positive in 15 cases of which 2 of them with a negative CT for bone erosion. Five cases were false negative, but 2 of them had contralateral ear pathology and in one case bone erosion was not found. We conclude that in some patients SPECT can be a complementary diagnostic procedure in cholesteatomatous bone lesions.

Percutaneous dilatational cricothyroidotomy: outcome with 44 consecutive patients.

OBJECTIVE: To assess the value of the percutaneous dilatational technique in elective cricothyroidotomy. DESIGN: Forty-four consecutive patients requiring prolonged mechanical ventilation. SETTING: The general 14-bed intensive care unit of a university hospital. INTERVENTIONS: Fourty-four percutaneous dilatational cricothyroidotomies using a multiple-dilator wire-guided procedure. MEASUREMENTS AND RESULTS: The average duration for the procedure was 11 min in 37 patients. No significant complications occurred intraoperatively except for one paratracheal cannula insertion. Postoperative complications were one case of stoma infection, three cases of transient phonatory changes, two cases of a small peristomal granuloma, and one case of persistent stoma. Of 21 decannulated patients, 16 survived to discharge. Long-term follow-up was possible in 14 surviving patients. All were asymptomatic several months after decannulation. CONCLUSIONS: Percutaneous dilatational cricothyroidotomy can be a quick, safe technique, as good as the percutaneous subcricoidal approach in ventilated, critically ill patients.

Isolation of a gene essential for biosynthesis of the lipopeptide antibiotics plipastatin B1 and surfactin in Bacillus subtilis YB8.

Bacillus subtilis YB8 was found to produce the lipopeptide antibiotics surfactin and plipastatin B1. A gene, lpa-8, required for the production of both lipopeptides was cloned from strain YB8. When this gene was inactivated in strain YB8, neither surfactin nor plipastatin B1 was produced. However, the defective strain transformed with an intact lpa-8 gene had restored ability to produce both peptides. Nucleotide sequence analysis of the region essential for the production of the peptides revealed the presence of a large open reading frame. The deduced amino acid sequence of lpa-8 (224 amino acid residues) showed sequence similarity to that of sfp (from surfactin-producing B. subtilis), lpa-14 (from iturin A- and surfactin-producing B. subtilis), psf-1 (from surfactin-producing Bacillus pumilus), gsp (from gramicidin-S-producing Bacillus brevis), and entD (from siderophore-enterobactin-producing Escherichia coli), which are able to complement a defect in the sfp gene and promote production of the lipopeptide antibiotic surfactin. The sequence similarity among these proteins and the product similarity of cyclic peptides suggests that they might be involved in the biosynthesis or secretion of the peptides.

Production of a lipopeptide antibiotic, surfactin, by recombinant Bacillus subtilis in solid state fermentation.

Production of a lipopeptide antibiotic, surfactin, in solid state fermentation (SSF) on soybean curd residue, Okara, as a solid substrate was carried out using Bacillus subtilis MI113 with a recombinant plasmid pC112, which contains lpa-14, a gene related to surfactin production cloned at our laboratory from a wild-type surfactin producer, B. subtilis RB14. The optimal moisture content and temperature for the production of surfactin were 82% and 37 degrees C, respectively. The amount of surfactin produced by MI113 (pC112) was as high as 2.0 g/kg wet weight, which was eight times as high as that of the original B. subtilis RB14 at the optimal temperature for surfactin production, 30 degrees C. Although the stability of the plasmid showed a similar pattern in both SSF and submerged fermentation (SMF), production of surfactin in SSF was 4-5 times more efficient than in SMF. (c) 1995 John Wiley & Sons, Inc.

[Treatment and outcome of infantile cholesteatoma surgery]. / Tratamiento y resultados en la cirugia del colesteatoma infantil.

Infantile Cholesteatoma has been lately the aim of a large number of papers dealing with its natural history and optimal treatment. The outcome of 26 cases of ear surgery, done between 1990 and 1991, are reviewed. The etiology of Cholesteatoma was congenital in 2 cases, iatrogenic in an other one and unknown for the remainder (88%). Fifteen (15) closed surgical procedures and 11 open were carry out, achieving global removal of lesions in 76 percent of cases. Ninety-one (91%) of open tympanoplasties and 66 percent of closed procedures. Six cases evolved to recidivation (and later reoperatively reconverted in open cases) owing either to the erosion of the ossicular chain or encroachment of the recessus. Reconstructions of the ossicular chain was undertaken in 61.5 percent of cases and the hearing preserved in all instances and improved in 35 percent of reconstructions.

Adenoid cystic carcinoma initially diagnosed and treated as hemangioma.

Adenoid cystic carcinoma initially diagnosed and treated as hemangioma. A case diagnosed as having a hemangioma of the soft palate according to clinical and arteriographic findings is discussed. Recurrence appeared one year after embolization. Arteriography showed no vascular lesion and histopathologic study revealed an adenoid cystic carcinoma. It is stated that imaging studies may be insufficient.

[Mikulicz disease as the beginning of AIDS]. / Enfermedad de Mikulicz como debut en un caso de SIDA.

Major salivary lymphoepithelial lesions accounted for less than 3 percent of all benign parotid tumors, prior to AIDS acquaintance. Defined as the presence of enlargement of one or more salivary glands and, in some cases, with diminished salivary function. The paper present the case of an acquired immunodeficiency syndrome starting as a Mikulicz's disease. Reviewed the medical literature and treatment options.

[Benign nasal melanosis transformed into malignant mucosal melanoma: a documented case]. / Melanosis benigna nasal hacia melanoma maligno mucoso: una transformación documentada.

We report a case of nasal mucosal melanosis transformed into malignant mucosal melanoma. We review the feature of these disorders, their association, and preventive treatment.

[Jugular phlebectasia. Apropos a case]. / Flebectasia yugular. A propósito de un caso.

We present a case of 6-years-old male with an internal jugular phlebectasia, diagnosed at our Hospital. Review of the bibliography, and complementary examination, like doppler, echography and digital intravenous angiography subtraction (DIVAS) was made.

Plasmid transformation in Bacillus subtilis NB22, an antifungal-antibiotic iturin producer.

A transformation system with plasmids was developed for Bacillus subtilis NB22, an antibiotic iturin producing strain. Treatment of B. subtilis NB22 with 4 M KCl was effective for the induction of competence, followed by uptake of plasmid DNA in the presence of polyethylene glycol. The efficiency of transformation of this bacterium with pC194 and pUB110 was 4.1 X 10(3) and 1.5 X 10(3) transformants per micrograms DNA, respectively and the transformation frequency was 3.3 X 10(-3) and 7.2 X 10(-4), transformants per viable cell, respectively. This method was much faster and three orders of magnitude more efficient in transformation efficiency than protoplast transformation methods.

The copy number of Bacillus plasmid pRBH1 is negatively controlled by RepB protein.

The replication control mechanism of Bacillus plasmid pRBH1 was analysed; pRBH1 contains four promoters, P1 to P4, and a large inverted repeat (63 base pairs) upstream of the protein (RepB) coding sequence. The stem and loop structure is surrounded by two promoters, P1 and P3, with different directions of transcription. One base substitution in the loop structure caused a change in copy number. Since the P1 promoter is located upstream of the replication origin of pRBH1, the transcript from the P1 promoter might serve as the primer of DNA replication. In vivo transcription from the P1 promoter was repressed by a trans-acting plasmid gene product. Since the RepB protein is involved in copy number control and RepB contains the consensus amino acid sequence of DNA binding proteins, RepB was thought to be the repressor. It was concluded from these data that the inverted repeat is involved in the control of copy number of the plasmid pRBH1. The RepB protein also contains two regions highly homologous with the Rom protein encoded on Escherichia coli plasmid ColE1. The possible mechanism for the copy number control of the plasmid via RepB protein and/or RNAs is discussed.

Complete nucleotide sequences of Bacillus plasmids pUB110dB, pRBH1 and its copy mutants.

The deletion plasmids, pRBH1 (1.5 MDa, kanamycin resistance, Kmr) and pUB110dB (1.5 MDa, Kmr), were obtained from pTB913 (2.9 MDa, Kmr, isolated from a thermophilic bacillus) and pUB110 (3.0 MDa, Kmr, from Staphylococcus aureus), respectively. All the nucleotide sequences of these deletion plasmids were determined. Replication origin regions of pRBH1 and pUB110dB contained, respectively, 63 base-pair inverted repeat and a large open reading frame, encoding RepB protein (235 amino acid residues). The nucleotide sequences were identical to each other except for one base in the center of the inverted repeat. Two copy number mutant plasmids, pRBHC3 and pRBHC7, were obtained from pRBH1. The mutation points were located at different positions in the RepB protein coding region (Gly to Asp for pRBHC3 and Gly to Glu for pRBHC7). RepB protein was shown to be involved in the copy number control of these plasmids.