A cosmid-based genomic library of Serratia marcescens N28b was introduced into Escherichia coli and clones were screened for a bacteriocin 28b insensitive phenotype. One clone was found that showed partial resistance to bacteriocin 28b. By using Tn5tac1 insertions it was shown that this phenotype was due to the expression in E. coli of an outer-membrane protein of 17 kDa (Omp4). The DNA region defined by insertion mutagenesis was sequenced and found to contain an ORF of 515 bp. The deduced amino acid sequence has 172 residues with a theoretical molecular mass of 18.4 kDa. The protein contains an N-terminal signal sequence of 24 amino acid residues and, when compared to other enterobacterial outer-membrane proteins, most closely resembles a family of small outer-membrane proteins of Enterobacteriaceae whose known functions appear to be related with virulence. Immunoblotting experiments showed that Omp4 is present in 15 biotypes of S. marcescens. The bacteriocin 28b resistance phenotype conferred on E. coli by Omp4 appears to be pleiotropic since overexpression of the Omp4-encoding gene leads to a decrease in the amount of OmpA, OmpF and/or OmpC; OmpA and OmpF are the receptors for bacteriocin 28b in E. coli.

Amino Acid Sequence↗

PubMed1995

Protection against bacteriocin 28b in Serratia marcescens is apparently not related to the expression of an immunity gene.

The gene encoding bacteriocin 28b from Serratia marcescens N28b (bss gene) has been cloned in Escherichia coli and its nucleotide sequence has been determined. The genetic determinants coding for other well-characterized bacteriocins from enterobacteria (colicins) are located in plasmids and they have always been shown to contain a gene responsible for immunity located downstream from the bacteriocin structural gene. In some cases there is another gene located downstream from the immunity gene, which is responsible for bacteriocin release. Analysis of bacteriocin 28b release and the sensitivity to this bacteriocin of E. coli strains harbouring recombinant plasmids containing the bss gene showed that bacteriocin 28b is not released from the cell in these strains and that their phenotypic insensitivity is not associated with any region close to the structural gene. The nucleotide sequence of the region downstream from the bss gene contains two putative open reading frames transcribed in the opposite direction to the bss gene. These open reading frames apparently encode proteins that seem not to be involved in bacteriocin immunity or release. Moreover, a S. marcescens N28b genomic library was screened and no immunity gene was found. Therefore, bacteriocin 28b differs greatly from the bacteriocins from other enterobacteria, and in the following senses it is unique: firstly, the gene encoding bacteriocin 28b seems to be located on the chromosome, and secondly, insensitivity to this bacteriocin in S. marcescens N28b is not associated with the expression of an immunity gene.

Amino Acid Sequence↗

PubMed1995

[Eosinophilic pustular folliculitis in acquired immunodeficiency syndrome. Report of 6 cases].

Eosinophilic pustulous foliculitis (EPF) is a rare dermatosis which has been reported in association with the human immunodeficiency virus infection. Six patients infected with HIV are reported with advanced disease in whom the diagnosis of EPF was made. All patients has a highly pruritic follicular papular rash. In all cases the pathology study revealed a mixed inflammatory infiltrate with predominance of eosinophils at the infundibulum of the pilous folliculi. Two patients had eosinophilia in peripheral blood. Therapy with antihistaminic agents and topical corticosteroids was ineffective in all cases. A favourable therapeutic response was achieved with phototherapy associated with the topic application of disodium cromoglycate 4%.

Adult↗

PubMed1994

Transformation of Aspergillus parasiticus using autonomously replicating plasmids from Aspergillus nidulans.

A genetic transformation system for the aflatoxin-producing fungus Aspergillus parasiticus using two autonomously replicating plasmids from A. nidulans (ARp1 and pDHG25) is reported. Transformation frequencies using the plasmid pDHG25 were from 5 x 10(2) to 2.5 x 10(4) transformants per 10(6) viable protoplasts and microgram DNA. The stability of the plasmids in the transformants was also studied. This transformation system offers a new opportunity to clone genes related to aflatoxin production using appropriate aflatoxin-defective mutants.

Aspergillus↗

PubMed1994

Anticonvulsant properties of copper acetazolamide complexes.

Two copper acetazolamide complexes were synthesized for evaluation as anticonvulsant agents. These complexes were found to be more effective as anticonvulsants than the acetazolamide.

Acetazolamide↗

PubMed1994

Reductions, relative equilibria, and bifurcations in the generalized van der Waals potential: Relation to the integrable cases.

Explore the source record for details and available documents.

Journal Article↗

PubMed1994

[Polyneuropathies and dysglobulinemias].

We review the concept fo Monoclonal Gammopathy emphasizing that the so called benign forms, with or without polyneuropathy can have an unpredictable evolution. Polyneuropathies associated to monoclonal gammopathy-IgM, IgG, IgA, Waldestrom's disease, Multiple myeloma, Osteosclerotic myeloma (POEMS), Amyloidosis and Cryoglobulinemias are reviewed. They generally are solely sensory, sensorimotor or rarely, solely motor. The importance of neuro-physiological studies and nerve biopsy is emphasized. For progressive forms, treatment with plasmapheresis, immunotherapy, corticoids or intravenous gammaglobulin is suggested.

Aged↗

PubMed1993

Nucleotide sequence of a Trichophyton mentagrophytes HindIII mitochondrial DNA fragment containing a tRNA gene cluster.

A 0.85-kb HindIII mitochondrial DNA fragment of the dermatophytic fungus Trichophyton mentagrophytes has been sequenced. The fragment contains eight complete genes which corresponds to a tRNA gene cluster. From 5' to 3', the sequenced genes code for tRNA(thr), tRNA(glu), tRNA(val), tRNA(met1), tRNA(met3), tRNA(leu), tRNA(ala), and tRNA(phe). This tRNA gene cluster is located downstream of the larger ribosomal RNA gene. The particularities of the sequenced genes and their comparison with other fungal tRNA mitochondrial genes are reported.

Base Sequence↗

PubMed1993

An improved medium for distinguishing between homofermentative and heterofermentative lactic acid bacteria.

An improved solid medium for differentiating between homofermentative and heterofermentative lactic acid bacteria is proposed. It was developed to support the growth of wine strains unable to grow in other media. However, it can be employed as a general medium for the lactic acid bacteria that utilize fructose.

Bacteriological Techniques↗

PubMed1993

[Clinical correlations and evoked potentials in 29 cases of definitive multiple sclerosis].

Aiming to correlate the alterations in evoked potentials with the initial clinical manifestations of multiple sclerosis, 29 patients with the disease were studied and 19 were followed for a lapse ranging from 1 to 11 years. Visual evoked potentials were studied in all the patients and 51% were abnormal. Auditory evoked potentials were assessed in 26 patients and 26% were abnormal. Somatosensory evoked potentials were made in 21 patients and 61% were abnormal. We found no relationship between clinical status and abnormalities in evoked potentials. In the followed patients, those with the worst clinical deterioration, initially had cerebellar symptoms and pyramidal signs did not predict a bad evolution. There was no relationship between evolution time and aggravation of the disease. There was no general correlation between clinical evolution and alterations in evoked potentials however the presence of bilaterally abnormal auditory evoked potentials was a predictor of bad prognosis. It is concluded that evoked potentials are relevant diagnostic tools in multiple sclerosis, specially when they detect subclinical alterations.

Adult↗

PubMed1993

[Cerebral abscess caused by Toxoplasma gondii and AIDS. Report of a case with anatomo-pathological study].

We report a 47 year old woman that presented to the hospital with an intracranial hypertension syndrome, a right hemiparesis and a several months history of progressive malaise and behavioral disturbances. During the hospital stay, positive HIV antibodies were detected and CAT scan showed a profound left parietal rounded hypodense lesion. The patient died 21 days after admission and the postmortem pathological study showed a deep abscess in the left basal ganglia, with recognizable Toxoplasma gondii trophozoites.

Acquired Immunodeficiency Syndrome↗

PubMed1992

Cloning and DNA sequence analysis of a bacteriocin gene of Serratia marcescens.

Serratia marcescens N28b synthesized and secreted a bacteriocin, with a molecular mass of 45 kDa, which was capable of inhibiting the growth of Escherichia coli. The expression of this bacteriocin was negligible unless induced with mitomycin C. The genes encoding the bacteriocin were cloned in plasmid pBR328. E. coli harbouring recombinant plasmid pBA189 or pBA289 expressed the Serratia marcescens N28b bacteriocin. The nucleotide sequence of the bss gene (Serratia marcescens N28b bacteriocin structural gene) was determined. The predicted amino acid sequence of the carboxy-terminal part of the bacteriocin 28b had a high degree of similarity to the pore-forming domains of colicins A, E1, B, N, Ia and Ib.

Amino Acid Sequence↗