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Biomedical subjects

L Paulin

Publications and source records attributed to L Paulin.

At least 55 records · Page 3Linked to original sources
PubMed1995

Mycobacterium branderi sp. nov., a new potential human pathogen.

A number of mycobacterial strains with similar growth characteristics, metabolic properties, and lipid compositions, which were previously placed in the Helsinki group (E. Brander, E. Jantzen, R. Huttunen, A. Juntunen, and M.-L. Katila, J. Clin. Microbiol. 30:1972-1975, 1992), were characterized by performing 16S rRNA gene sequencing. Of the 14 strains studied, 9 had a unique, previously undescribed sequence in the variable region of 16S rRNA. These nine strains, all of which were isolated from respiratory tract specimens, were nonpigmented and grew at 25 degrees C to 45 degrees C, reaching full colony size after 2 to 3 weeks. They produced arylsulfatase, nicotinamidase, and pyrazinamidase and were negative for Tween 80 hydrolysis, catalase, urease, and nitrate reductase activities, and niacin. Their glycolipid patterns were identical. A mycolic acid analysis performed by using thin-layer chromatography showed that these organisms contained alpha-mycolates, ketomycolates, and carboxy mycolates. Gas-liquid chromatography revealed that 2-eicosanol was the major alcohol and hexacosanoic acid was the major mycolic acid cleavage product. On the basis of their growth, biochemical, and lipid characteristics and their unique 16S rRNA sequence, we propose that these organisms should be assigned to a new species, Mycobacterium branderi. Comparative 16S rRNA sequencing revealed that this new species is closely related to Mycobacterium celatum, Mycobacterium cookii, and Mycobacterium xenopi. Strains 52157T (T = type strain) and 43548 have been deposited in the American Type Culture Collection as strains ATCC 51789 and ATCC 51788, respectively.

Antibiotics, Antitubercular↗
PubMed1995

Characterization of Hafnia alvei by biochemical tests, random amplified polymorphic DNA PCR, and partial sequencing of 16S rRNA gene.

Hafnia alvei strains which possess the attachment-effacement gene (eaeA) may have clinical importance as new diarrhea-causing pathogens and should therefore be differentiated from other H. alvei strains. We characterized diarrheal H. alvei strains, which were positive in the PCR test for the eaeA gene, using biochemical tests not routinely used for identification of members of the family Enterobacteriaceae, and compared them with eaeA-negative strains isolated from different clinical and nonclinical sources to find characteristics useful for identification. Random amplified polymorphic DNA (RAPD)-PCR and partial sequencing of the 16S rRNA gene were utilized to study the genetic diversity of the isolates. The eaeA-positive strains were found to have many characteristic biochemical properties. Negative reactions in the 2-ketogluconate and histidine assimilation tests and a positive reaction in the 3-hydroxybenzoate assimilation test may be useful in routine diagnostics. Nearly identical RAPD-PCR profiles and identical 353-bp fragments of the 16S rRNA genes indicated little genetic diversity among the eaeA-positive strains. The low level of homology (92%) in the partial 16S rRNA genes of eaeA-positive and -negative H. alvei strains raises questions about the taxonomic positioning of eaeA-positive H. alvei.

Base Sequence↗
PubMed1995

The codon usage of the nisZ operon in Lactococcus lactis N8 suggests a non-lactococcal origin of the conjugative nisin-sucrose transposon.

An 11.6 kb area downstream from the structural gene of nisin Z in the conjugative nisin-sucrose transposon of Lactococcus lactis subsp. lactis N8 was cloned and sequenced. Analysis of the sequence revealed eight open reading frames, nisZBTClPRK, followed by a putative rho-independent terminator (delta G degrees = -4.7 kcal/mol). The C-terminal hydrophilic domain of the NisK protein is homologous to the C-termini of several histidine kinases of bacterial two-component regulator systems, such as SpaK from Bacillus subtilis and KdpD and RcsC of Escherichia coli. The nisin Z biosynthetic genes were highly similar with the genes of the nisin A operons having, however, a 0-3% difference in the amino acid sequences of the individual proteins. The codon usage of eleven genes within the same conjugative transposon was calculated and found to be strikingly different from that of other lactococcal genes. This, together with the low GC-content (32%) compared to the 38% (G+C) of the lactococcal chromosome in general strongly suggests a non-lactococcal origin of this transposon.

Amino Acid Sequence↗
PubMed1994

Cloning of cmpE, a plasmid-borne catechol 2,3-dioxygenase-encoding gene from the aromatic- and chloroaromatic-degrading Pseudomonas sp. HV3.

Pseudomonas sp. strain HV3 degrades aromatics and chloroaromatics. It harbours a mega-plasmid, designated pSKY4, from which the gene cmpE, encoding a catechol 2,3-dioxygenase (C23O) catalyzing the conversion of catechol to 2-hydroxymuconic semialdehyde, was cloned and sequenced. The deduced amino acid (aa) sequence shows the highest homology, 52%, to the deduced aa sequences of xylE1 and dmpB. The deduced 307-aa sequence of cmpE contains the extradiol ring-cleavage signature in the same position as other 307-aa C23O-encoding genes.

Amino Acid Sequence↗
PubMed1994

A corolla- and carpel-abundant, non-specific lipid transfer protein gene is expressed in the epidermis and parenchyma of Gerbera hybrida var. Regina (Compositae).

We are examining the floral organ differentiation in Compositae by isolating and characterizing corolla abundant genes. Differential screening of a cDNA library made from the ray floret corolla of Gerbera hybrida var. Regina revealed an abundant cDNA clone which is expressed in the corolla but not in leaves. This cDNA (gltp1) codes for a polypeptide similar to non-specific lipid transfer proteins of the plants. The gltp1 gene is expressed only in the corolla and carpels and is developmentally regulated during corolla development. The gltp1 mRNA accumulates both in epidermal cell layers and in the mesophyll of the corolla. In the stylar part of the carpel, the gltp1 mRNA can be detected in the epidermal and in parenchymal cells but not in the transmitting tissue. Analogous patterns of gltp1 expression in the corolla and carpel may indicate that similar genetic programmes operates during the development of these two tissues.

Amino Acid Sequence↗
PubMed1994

Antisense inhibition of low-affinity nerve growth factor receptor in kidney cultures: power and pitfalls.

1. Antisense inhibition of gene expression implies that the expression of the target protein is selectively inhibited at either the translational or the transcriptional level by complementary DNA or RNA constructs that are antiparallel to the target sequence. The antisense inhibition strategy provides means to study the roles of individual proteins and has, in spite of its limitations, gained a wide range of both therapeutic and experimental applications. 2. In developmental biology, protein expression has been selectively inhibited by the use of antisense gene transfection and by antisense deoxyoligonucleotides. The transfectability of embryonic tissues is variable, but in general fetal and embryonic cells take up foreign DNA relatively efficiently, in particular, short deoxyoligonucleotides that penetrate mesenchymal cells within a few hours without any manipulation. 3. We have now evaluated the advantages and pitfalls of antisense inhibition by deoxyoligonucleotides in organ culture and describe our experience from the inhibition of low-affinity nerve growth factor receptor expression in embryonic mouse and rat kidneys. 4. The expression of nerve growth factor receptor can be specifically inhibited by deoxyoligonucleotides, but the target sequence-dependent window of, in particular, phosphorothioate-modified oligonucleotides is quite narrow. The culture conditions affect the response to the oligonucleotides and their cellular incorporation is variable with respect to the cell type and stage of differentiation.

Animals↗
PubMed1994

The nucleotide sequence of potato virus A genomic RNA and its sequence similarities with other potyviruses.

The complete nucleotide sequence of potato virus A (PVA) was obtained from six independent cDNA clones. The RNA genome of PVA is 9565 nucleotides long and contains one open reading frame (ORF) of 9177 bases encoding a large polyprotein of 3059 amino acids with a calculated M(r) of 340K. Seven potential proteinase NIa, one HC-pro and one P1 proteinase recognition sites were found in PVA polyprotein by searching for cleavage site consensus sequences amongst the potyvirus group. The non-coding region preceding the ORF is 161 nucleotides long. The termination codon is followed by a 227-nucleotide sequence. Overall nucleotide sequence identity compared with several completely sequenced potyvirus genomes is between 53 and 58%, with overall amino acid sequence identity between 65 and 71%. When the putative amino acid sequences of individual proteins of PVA were compared with the corresponding proteins of other potyviruses, P1 and P3 appeared the least conserved (34 to 53%) whereas the other proteins were in most cases from 63 to 80% identical to each other.

Amino Acid Sequence↗
PubMed1994

Hafnia alvei in stool specimens from patients with diarrhea and healthy controls.

We found an epidemiological association of Hafnia alvei with diarrhea, because the organism was isolated from 12 of 77 (16%) adult Finnish tourists to Morocco who developed diarrhea and from 0 of 321 tourists without diarrhea (P < 0.001). From another group of 112 adult Finnish diarrheal patients, only 2 (2%) yielded H. alvei. In contrast to some Bangladeshi strains of H. alvei, the Finnish strains were negative for the attachment-effacement lesion by an in vitro fluorescent acting staining test and also did not show homology to the Escherichia coli attachment-effacement gene (eaeA) by PCR. These results suggest that a mechanism or mechanisms other than the attachment-effacement lesion may also be involved in the association of H. alvei with diarrhea.

Actins↗
PubMed1990

Secretory S complex of Bacillus subtilis: sequence analysis and identity to pyruvate dehydrogenase.

We have cloned the operon coding for the Bacillus subtilis S complex, which has been proposed to be a component in protein secretion machinery. A lambda gt10 library of B. subtilis was screened with antiserum directed against the Staphylococcus aureus membrane-bound ribosome protein complex, which is homologous to the B. subtilis S complex. Two positive overlapping lambda clones were sequenced. The S-complex operon, 5 kilobases in size, was shown to contain four open reading frames and three putative promoters, which are located upstream of the first, the third, and the last gene. The four proteins encoded by the operon are 42, 36, 48, and 50 kilodaltons in size. All of these proteins were recognized by antisera separately raised against each protein of the S. aureus membrane-bound ribosome protein and B. subtilis S complexes, thus verifying the S-complex identity of the lambda clones. Sequence analysis revealed that all four proteins of the B. subtilis S complex are homologous to the four subunits of the human pyruvate dehydrogenase (PDH). Also, the N terminus of the 48-kilodalton protein was found to have 70% amino acid identity with the N-terminal 211 amino acids, determined so far, from the E2 subunit of B. stearothermophilus PDH. Furthermore, chromosomal mapping of the S-complex operon gave a linkage to a marker gene located close to the previously mapped B. subtilis PDH genes. Thus, the S complex is evidently identical to the B. subtilis PDH, which has been shown to contain four subunits with molecular weights very similar to those of the S complex. Therefore, we propose that the S complex is not a primary component of protein secretion.

Amino Acid Sequence↗
PubMed1990

Easy selection of recombinant clones.

We have developed a polymerase chain reaction (PCR)-based procedure to facilitate the selection of recombinant clones. The insert to be cloned is ligated to an antibiotic resistance marker. The ligation product is amplified by PCR, followed by standard cloning procedure into a bacterial vector. The selection for the antibiotic resistance coded by the PCR product ensures 100% insertion frequency, eliminating the screening of the transformants.

Bacillus subtilis↗
PubMed1989

Metabolic and hormonal responses during exercise at 20 degrees, 0 degrees and -20 degrees C.

This study was designed to clarify the effects of cold air exposure on metabolic and hormonal responses during progressive incremental exercise. Eight healthy males volunteered for the study. Informed consent was obtained from every participant. The following protocol was administered to each subject on three occasions in a climatic chamber in which the temperature was 20 degrees, 0 degree or -20 degrees C with relative humidity at 60% +/- 1%. Exercise tests were conducted on an electrically braked ergocycle, and consisted of a progressive incremental maximal exercise. Respiratory parameters were continuously monitored by an automated open-circuit sampling system. Exercise blood lactate (LA), free fatty acids (FFA), glucose levels, bicarbonate concentration (HCO-3), acid-base balance, plasma epinephrine (E) and norepinephrine (NE) were determined from venous blood samples obtained through an indwelling brachial catheter. Maximal oxygen uptake was significantly different between conditions: 72.0 +/- 5.4 ml kg-1 min-1 at 20 degrees C; 68.9 +/- 5.1 ml kg-1 min-1 at 0 degree C and 68.5 +/- 4.6 ml kg-1 min-1 at -20 degrees C. Workload, time to exhaustion, glucose levels and rectal temperature decreased significantly at -20 degrees C. Catecholamines and lactate values were not significantly altered by thermal conditions after maximal exercise but the catecholamines were decreased during rest. Bicarbonate, respiratory quotient, lactate and ventilatory thresholds increased significantly at -20 degrees C. The data support the contention that metabolic and hormonal responses following progressive incremental exercise are altered by cold exposure and they indicate a marked decrease in maximal oxygen uptake, time to exhaustion and workload.

Adult↗
PubMed1989

[Evaluation of short stature in boys: delayed growth or constitutional short size?].

When assessing a child with short stature it may be difficult to differentiate between delayed growth and adolescence and constitutional short stature, which usually provide a completely different prognosis of adult height. The growth data on 43 boys were retrospectively studied after they had reached adult height. Two groups were differentiated according to their final height, i.e. boys with delayed growth and adolescence; and boys with constitutional short stature. From these data a discriminant analysis was worked out that could be used as a means to facilitate the prediction of adult height in boys short stature.

Age Determination by Skeleton↗
PubMed1987

Ornithine decarboxylase, S-adenosyl-L-methionine decarboxylase and arginine decarboxylase from Mycobacterium bovis (BCG).

Ornithine decarboxylase (ODC), S-adenosyl-L-methionine decarboxylase (AMDC) and arginine decarboxylase (ADC) activities were detected for the first time in extracts of Mycobacterium bovis (BCG). All the decarboxylases differed from corresponding known bacterial decarboxylases in that: a) ODC did not require GTP for activity; b) ODC was not inhibited by any known inhibitor of bacterial ODCs; c) AMDC and ADC did not require Mg2+-ion for activity and were not markedly inhibited by any known inhibitor of the decarboxylases of other bacteria.

Adenosylmethionine Decarboxylase↗
PubMed1986

The effects of 1-aminooxy-3-aminopropane and S-(5'-deoxy-5'-adenosyl)methylthioethylhydroxylamine on ornithine decarboxylase and S-adenosyl-L-methionine decarboxylase from Escherichia coli.

1-Aminooxy-3-aminopropane (APA) was shown to be a potent competitive inhibitor (Ki = 1.0 nM) of partially purified Escherichia coli ornithine decarboxylase. APA did not inhibit S-adenosyl-L-methionine decarboxylase and spermidine from E. coli. S-(5'-Deoxy-5'-adenosyl)methylthioethylhydroxylamine (AMA), which is a structural analogue of decarboxylated S-adenosyl-L-methionine, was for the first time shown to be an irreversible inhibitor of bacterial S-adenosyl-L-methionine decarboxylase and a competitive inhibitor (Ki = 47 microM) of bacterial ornithine decarboxylase. AMA had no effect on spermidine synthase.

Adenosylmethionine Decarboxylase↗