PubMed Health⌕ Search

Biomedical subjects

C Ponte

Publications and source records attributed to C Ponte.

At least 37 records · Page 2Linked to original sources
PubMed1993

Adherence of Corynebacterium urealyticum (CDC group D2) and Corynebacterium jeikeium to intravascular and urinary catheters.

The ability of Corynebacterium urealyticum, Corynebacterium jeikeium and other control strains to adhere to two intravascular catheters (polyvinyl chloride and Teflon) and one urinary catheter (Teflon-coated rubber) was studied. Results demonstrated that the Corynebacterium species adhered to all catheter materials in greater numbers than a control strain of Micrococcus luteus (p < 0.001). There was not a clear difference in the ability of the strains of Corynebacterium jeikeium and Corynebacterium urealyticum to adhere to the catheters tested, so that differences other than this property could explain their different pathogenicity for humans.

Bacterial Adhesion↗
PubMed1993

Non-urinary tract infections caused by multiply antibiotic-resistant Corynebacterium urealyticum.

Five patients with non-urinary tract infections caused by Corynebacterium urealyticum were seen during an 8-year period at a university hospital in Madrid. Bacteremia (one case) and wound infections (four cases) were the most relevant features of these cases. Treatment with vancomycin, surgery, and supportive measures contributed to a favorable outcome for four of the five patients.

Adult↗
PubMed1993

Serological differentiation between acute (late control) and endocarditis Q fever.

AIMS: To differentiate the serological profiles of chronic (endocarditis) Q fever from the late follow up of acute cases. METHODS: Twenty patients (10 diagnosed with acute and 10 with endocarditis Q fever) were studied. Those diagnosed with acute infection were followed up from 2.5 to 88 months (mean 35.8 months). Serological variables included indirect immunofluorescence against phase I and II of Coxiella burnetii (IgM, IgG, and IgA), complement fixation and rheumatoid factor (RF). RESULTS: All patients with titres of IgA against phase I, after IgG removal, equal to or above 320 and a complement fixation value equal to or above 128 had endocarditis. No patient with acute Q fever had such a serological profile. CONCLUSIONS: The combination of IgA against phase I and complement fixation values may be sufficient to differentiate the serological profile of chronic (endocarditis) Q fever from the late follow up of acute cases.

Acute Disease↗
PubMed1992

A case of urinary tract infection caused by Corynebacterium urealyticum and coryneform group F1.

A case of urinary tract infection (UTI) caused by a fastidious, urea-splitting, antibiotic-sensitive coryneform, identified as CDC group F1, is described. The patient suffered from encrusted cystitis and had had previous and persistent UTIs caused by Corynebacterium urealyticum (formerly CDC group D2). Bacteriological cure was achieved after one month of treatment with amoxicillin plus acetohydroxamic acid.

Actinomycetales↗
PubMed1992

Pulsatility of growth hormone secretion and its relation to growth.

84 short children were submitted to nocturnal spontaneous growth hormone (GH) secretion tests and to provocative insulin-arginine tests. Discrepancies between the GH peak under the provocative test (I-AP) and nocturnal GH maximal peak (PA) and mean concentration (MC) were frequently observed, despite significant statistical correlation between I-AP and PA (r = 0.47; p < 0.02) and between I-AP and MC (r = 0.42; p < 0.02). Night profiles were evaluated by time analysis: 31 fitted a theoretical model, consisting of a cosine function of time (modelizable profiles). Spectral analysis, from Fourier transformation, indicated predominant periods after cluster analysis. The major predominant period in modelizable (n = 9) and in nonmodelizable (n = 28) profiles was close to 180 min and a secondary period was on average 122 min in modelizable (n = 20) and 105 min in nonmodelizable (n = 23) profiles. Two modelizable and two nonmodelizable profiles escaped this classification. The general, auxological and GH secretory status did not differ significantly between patients with modelizable and nonmodelizable profils. Growth velocity correlated with GH mean concentration (r = 0.36; p < 0.001), but not with plasma insulin-like growth factor-I levels nor with any of the pulsatility indices: number of peaks, main period, and pulse height index = mean GH peak/mean GH concentration. The relevance of GH pulsatility to growth is, therefore, unclear in humans.

Adolescent↗
PubMed1991

Comparative study of biosynthetic human growth hormone immunogenicity in growth hormone deficient children.

The immunogenicities of six recombinant human growth hormone (rhGH) preparations, from KABI (A rhGH191 and B rhGH192), Eli Lilly (C), Nordisk (D), Sanofi (E) and Serono (F), used to treat 260 GH-deficient children, have been compared using a common specific and sensitive procedure for antibody determination. For this purpose we developed two immunoassays: a competitive liquid radioimmunoassay using 125I-rhGH, and an immunometric solid enzymoimmunoassay in which the rhGHs were immobilized. Blood samples were collected from the GH-deficient children before treatment and after 3, 6, 9, 12, 18 and 24 months of therapy. Human GH antibodies were detected in children treated with 3 of the 6 rhGH preparations. Seven percent of the patients treated with hormone A, 14% with hormone B and 22% with hormone C formed antibodies against the respective rhGH. Differences in capacity and affinity of the hGH antibodies were observed between these anti-GH-positive groups. They could be divided into 2 groups according to their immunopotency. One group (7, 14 and 6% of the patients treated with hormones A, B and C, respectively) developed anti-hGH antibodies with very low binding capacities (30-100 fmol/ml). The other group (16% of the patients treated with hormone C) developed IgG-type antibodies to hGH with higher binding capacities (200-1,200 fmol/ml) and a measurable binding affinity (Ka = 10(8) M-1). These hGH antibodies partially inhibited the binding of labeled GH to its specific liver membrane receptor. However, because of their low titer, they did not inhibit growth in the treated children.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Relevance of the inoculum effect of antibiotics in the outcome of experimental infections caused by Escherichia coli.

The minimum dosage of antibiotics that reduced mortality in bacteraemic rats inoculated with two different Escherichia coli isolates was determined in an attempt to study the therapeutic importance of the inoculum effect. Low mortality rates (0-5%) at 48 h were obtained when antibiotics with minimal or no inoculum effect (ampicillin, cefuroxime, cefoxitin and gentamicin) were administered to yield serum levels 5 to 14 times the MIC, while antibiotics with a pronounced inoculum effect (piperacillin, cefotaxime and aztreonam) had to be administered to yield serum levels 57 to more than 1000 times the MIC determined with a standard (low) inoculum. All of the antibiotics with inoculum effect studied here are administered empirically in clinical practice at a higher dose than the microbiological and pharmacokinetic data would indicate (in order to reach peak serum concentrations exceeding the MICs of the pathogens by 4-10 times). Our experiment suggests that such high and empirical doses of antibiotics with inoculum effect may be justified.

Animals↗
PubMed1990

Growth hormone response to a bolus injection of 1-44 growth-hormone-releasing hormone in very short children with intrauterine onset of growth failure.

The release of growth hormone (GH) during the 120 min following a bolus venous injection of 1-44 GH-releasing hormone (GHRH) 2 micrograms/kg was studied in 52 prepubertal children aged 8.4 +/- 2.1 years, having a nonfamilial growth deficiency of prenatal onset (-3.26 +/- 1.13 SDS at birth, -3.22 +/- 0.88 SDS at the time of study) and a normal response to conventional GH stimulation tests. GH release reached a peak level of 96.1 +/- 60.2 microU/ml, being significantly higher than that found in 68 non-GH-deficient very short children whose growth failure had a postnatal onset, and not significantly correlated with the response to conventional tests. 26 of the 52 intrauterine growth retardation (IUGR) patients were re-tested with GHRH in similar conditions after 6-12 months of daily subcutaneous injections of GH and 2 days without. They reached at the second test a peak plasma GH level of 91.7 +/- 56.1 microU/ml, not different from their response to the first test. These data could be taken into consideration for long-term studies of the clinical effects of GH in IUGR children with persisting severe growth deficiency.

Child↗
PubMed1990

[Macroprolactinemia in a child].

An hyperprolactinemia, with basal serum prolactin levels ranging from 41 to 135 ng/ml was found to be coincidentally associated with psychosocial dwarfism in a 11 year-old boy. Sephadex G 100 exclusion chromatography showed that the predominating form of immunoreactive prolactin levels ranging from 41 to 135 ng/ml was found to be weight, differing from the regular occurrence of a 22 kilodalton major variant. Prolactin levels increased under TRH (increments between 29 and 76%) but were not blunted by bromocriptine at a dose of 2.5 mg/day. This so-called macroprolactinemia syndrome should be searched for whenever a discrepancy is noted between clinical symptoms and blood prolactin levels.

Adolescent↗
PubMed1990

[Transient complete somatotropin insufficiency. A retrospective study].

Two groups of patients with short stature and a limitation in the growth hormone (GH) response (peaks of 10 mU/l or below in response to 2 stimuli) differed by their GH responses at puberty: normalisation in group 1 (12 patients) and lack of normalisation in group 2 (13 patients). The condition of the patients of group 1 appeared to be less severe as judged by their initial height deficiency, their growth velocity and their GH peaks. Sex steroid hormone priming tests were highly discriminative, especially for the GH response to insulin stimulation. Other pituirary hormone deficiencies were never found in group 1, but did occur in group 2. Finally the beneficial long term effect of hGH therapy was questionable in group 1 in that there was no difference between the final heights of the treated (n = 7) and the untreated (n = 5) patients.

Adolescent↗
PubMed1989

Effect of Bacteroides fragilis on mortality induced by Escherichia coli in an experimental infection treated with cefotaxime, aztreonam or gentamicin.

The possibility that beta-lactamase-producing strains of Bacteroides fragilis can protect Escherichia coli from cefotaxime was studied in an in-vivo model of peritoneal infection in rats. The protective effect of cefotaxime, aztreonam and gentamicin in peritonitis induced by E. coli alone or combined with B. fragilis was evaluated by analysing mortality at 24 and 48 h after bacterial inoculation and treating the animals with two doses of each antibiotic. Comparisons, by drugs, at 24 and 48 h revealed that a statistically significant high mortality rate was obtained at 48 h when mixed infections were treated with cefotaxime, a drug very active in the infection caused by E. coli alone. Infections by mixed flora or E. coli alone treated with aztreonam or gentamicin did not show any significant difference in mortality rate analysed at 24 or 48 h. These in-vivo results confirm previous in-vitro studies and suggest that cefotaxime could be inactivated in mixed infections if a beta-lactamase-producing strain, such as B. fragilis, is involved in a clinical infection.

Animals↗
PubMed1989

[Ichthyosis linked to the X chromosome. Biochemical and endocrinologic study].

The case of a 6-year-old male patient suffering from X-chromosome-linked ichthyosis is presented. There was no steroid sulfatase activity in the proband's leucocytes and cutaneous fibroblasts. The activity was decreased in the proband's mother's leucocytes and in one brother, affected by a mild ichthyosis. Basal plasma levels of dehydroepiandrosterone and its sulfate were normal for the patient's age, suggesting that sulfates do not play a significant role in the production of free steroids. After 3 intramuscular injections of 1,500 units of human chorionic gonadotropin, plasma levels of testosterone increased normally, indicating that there was no associated primary gonadal insufficiency.

Child↗
PubMed1989

[Newborn infants of mothers with endocrinopathies].

When pregnancy and endocrinological disease evolve together, the course of the endocrinological disease and/or the pregnancy and/or the development of the fetus can be altered. Pathophysiological interactions and their therapeutic consequences are reviewed regarding 21-hydroxylase deficiency congenital adrenal hyperplasia, ovary and adrenal virilizing tumours, Addison disease, primary hyperaldosteronism, pheochromocytoma, Graves' disease, Hashimoto thyroiditis, primary hypothyroidism, primary hypo- and hyperparathyroidism and bromocriptine treatment of hyperprolactinaemia.

Adrenal Gland Diseases↗
PubMed1988

In vivo significance of the inoculum effect of antibiotics on Escherichia coli.

The minimum dosage of antibiotics which reduced mortality in rats intraperitoneally inoculated with an Escherichia coli isolate was determined. Low mortality rates (0-10%) were obtained when antibiotics with minimal or no inoculum effect (cefoxitin, cefmetazole and gentamicin) were administered to yield serum levels 3 to 20 times the MIC, while antibiotics with a pronounced inoculum effect (cefotaxime and aztreonam) had to be administered to yield serum levels 200 to 1,000 times the MIC determined with a standard (low) inoculum. Thus, it seems that the inoculum effect observed in vitro with some antibiotics for Escherichia coli may have clinical significance.

Animals↗