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Biomedical subjects

S Toma

Publications and source records attributed to S Toma.

At least 109 records · Page 6Linked to original sources
PubMed1988

Cloning of a novel pilin-like gene from Bordetella pertussis: homology to the fim2 gene.

A search for pilin genes in a Bordetella pertussis (Bp) genomic library has led to the identification of several clones which hybridize to synthetic oligonucleotides with sequences derived from amino acid sequences of Bp fimbrial subunits. One of these clones (corresponding to a gene we have named fimX) contains an open reading frame encoding a protein with a molecular weight of about 20 kD and a sequence similar but not identical to the fimbrial subunit fim2 and to other fimbrial protein sequences. In this communication we present the cloning and nucleotide sequence of the fimX gene and its homology to the fim2 gene. A genomic analysis on the positional relationship between the two genes is also presented.

Amino Acid Sequence↗
PubMed1988

Serotyping of Clostridium difficile.

A total of 246 live Clostridium difficile cultures were serotyped by a slide agglutination technique. Fifteen grouping antisera were produced which serotyped 98% of the cultures (241 of 246). Our results indicated that certain serogroups may have specific pathogenicity. Strains of serogroups A, G, H, K, S1, and S4 were cytotoxigenic and were isolated mainly from adult patients with pseudomembranous colitis or antibiotic-associated diarrhea. Nontoxigenic strains of serogroups D and Cd-5 were isolated mainly from asymptomatic neonates and small children. Some cross-reactions occurred among some strains of serogroups A, Cd-5, G, and K. These strains were further examined by analysis of protein profiles and restriction endonuclease patterns to elucidate their serology. Typing of C. difficile by using slide agglutination is a simple technique suitable for routine examination. Serogrouping may be a useful epidemiological marker and could help in elucidating the medical relevance of some C. difficile isolates.

Adult↗
PubMed1987

Clinical evaluation of three types of plasmapheresis in a patient with type IIa familial hypercholesterolemia.

Long-term plasmapheresis (PP) therapy was studied in a 56-year-old patient with homozygous type IIa familial hypercholesterolemia also suffering from severe coronary heart disease. Three different PP techniques, plasma exchange (PE), double-membrane-filtration plasmapheresis (DFP), and the recently developed low-density lipoprotein adsorbent column (adsorption plasmapheresis, adsorption PP), were used in an attempt to develop better means of managing the disease. All three techniques showed similar elimination efficiency with respect to plasma total cholesterol level. Adsorption PP with minimal supplemental plasma protein managed the circulatory status of the patient better than DFP during extracorporeal treatment. In the course of PP therapy xanthoma tuberosum markedly regressed, and the cardiac status of the patient was clearly improved.

Angiography↗
PubMed1987

Metabolism and pharmacokinetics of cinobufagin.

1. The metabolic fate of cinobufagin, a major component of the cardiotonic Senso, has been studied after i.v. administration to rats. Two metabolites were detected in rat serum and shown by n.m.r. and mass spectroscopy to be desacetylcinobufagin (I) and 3-epidesacetylcinobufagin (II). 2. Inhibitory activities of I and II on guinea-pig heart Na+/K+-ATPase were less than that of cinobufagin. 3. Serum or plasma levels of cinobufagin, I and II in rats, cats and dogs were determined by h.p.l.c. after i.v. and/or oral administration of cinobufagin. After i.v. administration, cinobufagin, I and II appeared in rat serum, but in dog and cat plasma only unchanged cinobufagin was present. After oral administration, only II was detected in rat serum, but neither cinobufagin nor either of its metabolites (I and II) were found in cat and dog serum.

Animals↗
PubMed1987

Association between breast and colorectal cancer in a sample of surgical patients.

The frequency of adenomatous polyps and adenocarcinomas of the large bowel in 95 patients mastectomized for breast cancer, and the prevalence of breast cancer in 77 women previously operated on for colorectal cancer were evaluated by means of a case-control study. The mastectomized patients as well as the control group, underwent a left-sided colonoscopy. The latter had been selected among women spontaneously referring to our gastroenterological out-patients clinic. The choice of this self selected control group could produce a under-estimation of the relative for colon cancer in mastectomized patients. Among mastectomized patients the frequency of adenomatous polyps and colorectal cancer was 10.5% and 5.3% respectively; while the control group showed 8.5% frequency for adenomatous polyps and 3.9% frequency for cancer. These figures are not statistically different. Patients operated on for colorectal cancer and the control group underwent clinical and mammographic examination. The prevalence of breast cancer among colorectal cancer patients and the control group women was 5.2% and 0.3% respectively (10 times higher): the difference was statistically significant (P less than 0.006). In spite of the relatively small number of studied cases, our finding are consistent with the hypothesis of a correlation between breast cancer and colorectal cancer.

Adenocarcinoma↗
PubMed1986

Primary tumor site, size, patients age and axillary lymph nodes in breast cancers.

This study considers the correlations between some characteristics of the primary tumor and level of lymph node involvement in 185 primary breast cancers. The average number of lymph nodes was higher in N+ women than in N- women. Primary tumors with a diameter of more than 4 cm yielded the highest mean number of lymph nodes (17.5). The risk of developing lymph node metastases was fourfold in tumors with a diameter greater than 2 cm when compared to those with a diameter less than or equal to 2 cm. The most commonly metastasized lymph node level, in both large and small tumors, was the first; however, one-fifth of the patients had simultaneous lymph node metastasis in all three axillary levels. Although the left breast was the most affected (58.9%), there was no evidence of a different risk of metastasis between the two breasts; 34.1% of the tumors were multifocal. Lymph node involvement was higher in women under 50 years of age with a primary tumor larger than 2 cm.

Adult↗
PubMed1986

New plasmid expression vectors for Bacillus subtilis.

The construction of new cloning vectors for Bacillus subtilis is described. They are derived from the in vitro joining of parts of pE194 and pUB110 DNAs. Their common feature is to present a cloning site immediately after the promoter and ribosome binding site of the erythromycin resistance gene, allowing the insertion and expression of either sticky or blunt ended DNA fragments coding for any heterologous gene. The cloning and expression of Escherichia coli beta-lactamase and EcoRI methylase are given as examples. The enzymes are efficiently synthesized by B. subtilis cells.

Bacillus subtilis↗
PubMed1986

nprR1 and nprR2 regulatory regions for neutral protease expression in Bacillus subtilis.

The gene coding for the Bacillus subtilis extracellular neutral protease was isolated from strain BGSC 1A341, an overproducer carrying the nprR2 region, and from strain 168, a normal producer with the nprR1 sequence. The sequence of about 600 nucleotides upstream from the start codon of the protease gene was determined for both strains. The two regions are highly homologous except for a stretch of 66 base pairs close to the promoter region, which is absent in the BGSC 1A341 gene. Northern blot analysis of the in vivo RNAs indicated that the different levels of enzyme secreted by the two strains were due to different amounts of transcripts that accumulated in the cells. Furthermore, at the end of exponential growth, the amount of transcript increased dramatically in the overproducer strain but remained approximately constant in the normal producer strain. The start point(s) for transcription, however, as determined by S1 nuclease mapping of the in vivo transcripts, appeared to be the same for both genes.

Bacillus subtilis↗
PubMed1986

Broad-spectrum enzyme-linked immunosorbent assay for detection of Legionella soluble antigens.

An enzyme-linked immunosorbent assay (ELISA) was developed which detected soluble antigens from culture extracts of Legionella pneumophila serogroups 1 to 8, L. micdadei, L. bozemanii serogroups 1 and 2, L. dumoffii, L. gormanii, L. longbeachae serogroups 1 and 2, L. wadsworthii, L. oakridgensis, L. anisa, L. feeleii serogroup 1, and L. jordanis. The assay was approximately 10-fold more sensitive for the eight L. pneumophila serogroups than for the other Legionella species tested. The ELISA detected Legionella antigens in the urine specimens of 25 of 35 patients with L. pneumophila serogroup 1, 3, 4, 6, and 8; L. micdadei; and L. longbeachae serogroup 1 infections. None of the 334 urine specimens from patients with either non-Legionella pneumonia or urinary tract infections was positive. For 10 patients from whom sequential urine specimens were available, Legionella antigens were not detectable from 7 to 19 days after laboratory diagnosis. Test sensitivity was not affected by heavy bacterial contamination. This ELISA offers the detection of a broad spectrum of Legionella antigens by a single test.

Antigens, Bacterial↗
PubMed1986

Conduction velocity of action potentials measured from unidimensional latency-topography in human and frog skeletal muscle fibers.

Conduction of an action potential along skeletal muscle fibers was graphically displayed by unidimensional latency-topography, UDLT. Since the slopes of the equipotential line were linear and the width of the line was constant, it was possible to calculate conduction velocity from the slope. To determine conduction direction of the muscle action potential elicited by electric stimulation applied directly to the muscle, surface recording electrodes were placed on a two-dimensional plane over a human muscle. Thus a bi-dimensional topography was obtained. Then, twelve or sixteen surface electrodes were placed linearly along the longitudinal direction of the action potential conduction which was disclosed by the bi-dimensional topography. Thus conduction velocity of muscle action potential in man, calculated from the slope, was for m. brachioradialis, 3.9 +/- 0.4 m/s; for m. biceps brachii, 3.6 +/- 0.2 m/s; for m. sternocleidomastoideus, 3.6 +/- 0.4 m/s. By using a tungsten microelectrode to stimulate the motor axons, a convex-like equipotential line of an action potential in UDLT was obtained from human muscle fibers. Since a similar pattern of UDLT was obtained from experiments on isolated frog muscles, in which the muscle action potential was elicited by stimulating the motor axon, it was assumed that the maximum of the curve corresponds to the end-plate region, and that the slopes on both sides indicate bi-directional conduction of the action potential.

Action Potentials↗
PubMed1985

Inhibitory effect of acupuncture on the vibration-induced finger flexion reflex in man.

Experiments were performed on 12 young and healthy subjects. The palmar side of the index finger was vibrated with a triangular wave form at randomly changed inter-stimulus intervals. This vibratory stimulation elicited a flexion movement of the index finger, which was depressed by acupuncture at 'Wai-Kuan.' It was generally observed that the depressive effect developed slowly and lasted for a long time. The depressive effect of acupuncture on this reflex was analyzed using a cross-correlation between the vibratory stimuli and motor unit spikes recorded from the flexor digitorum communis muscle. Cross-correlograms revealed two types of reflex responses. One of them showed a peak of time-locked spikes to the vibratory stimuli at a latency of 25 msec, which indicates monosynaptic activity of the motoneuron, and also showed time-unlocked spikes distributed in both sides of the peak, which implies polysynaptic activity. This type of response was frequently observed and was supposed to be elicited by the proprioceptive tonic vibration reflex. The other revealed no peaks, which indicates that only time-unlocked spikes to the stimuli are generated, and that these spikes are evoked via polysynaptic pathway. This type of response was supposed to be elicited by so-called exteroceptive vibration-induced finger flexion reflex. Since both types of reflex responses, i.e., mono- and polysynaptic ones, were equally depressed during acupuncture, it was concluded that the excitability of the motoneuron, a common output of this reflex, is lowered by acupuncture.

Acupuncture Therapy↗
PubMed1985

The effects of therapy on estrogen receptors in breast cancer.

The importance of estrogen receptors (ER) in predicting the results of therapy in advanced-stage breast carcinoma is now generally accepted. It is, therefore, important to know whether therapy itself, besides other factors, could affect ER status. The aim of the authors was to investigate this problem by reviewing the data from the literature. They have taken into account the effects of hormonal and/or chemotherapy and of radiotherapy, moreover, they have considered the importance of the time elapsed since the suspension of treatment. Hormonal therapy appears to be the kind of treatment more clearly correlated with a loss of ER: the authors have reported some hypotheses about the possible mechanisms of this action. The effect of chemotherapy is much less clear; the data about radiotherapy are few, unhomogeneous and, often, insufficient. Instead, it appears quite clear that ER tend to regain their original status after the suspension of therapy. More studies, are needed before any definitive conclusion can be drawn; it will be necessary to take into account also the possible effect of the different criteria for the preselection of patients. The actual data appear, anyway, to confirm the importance of routine receptor assay on breast tumors, especially after systemic treatment and independently of the kind of therapy itself.

Antineoplastic Agents↗
PubMed1985

Antibiotic susceptibility of blood and cerebrospinal fluid isolates of Haemophilus influenzae.

One hundred and sixty-nine blood and cerebrospinal fluid isolates of Haemophilus influenzae, collected in the Province of Ontario from children and adults from 1976 to 1983, were tested for susceptibility to six conventional and eight newer antibacterial drugs. Most active were ceftriaxone, ceftizoxime and cefotaxime (MIC90 less than or equal to 0.02 mg/l); latamoxef (moxalactam), acrosoxacin and ceftazidime were close behind with MIC90s in the 0.05-0.09 mg/l range. Twenty-five strains (14.8%) were beta-lactamase-producing and thus resistant to ampicillin. There were no chloramphenicol-resistant strains. The isolates showed intermediate but still clinically useful susceptibility to trimethoprim, rifampicin, cefuroxime, piperacillin and chloramphenicol and were least susceptible to gentamicin and sulphamethoxazole.

Adult↗