Evaluation of the complex trapping blocking-ELISA in a serological survey during the Belgian classical swine fever epizootic in 1990.
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Animals↗
Biomedical subjects
J Lefebvre
Publications and source records attributed to J Lefebvre.
The sequence of the gene encoding elongation factor Tu from Chlamydia trachomatis compared with those of other organisms.
Nucleotide (nt) sequences encoding the elongation factor Tu (EF-Tu), tRNA(Thr) and tRNA(Trp) from Chlamydia trachomatis have been determined. The environment of the EF-Tu-encoding gene (tuf), between two tRNA gene sequences, suggests that it is part of a tufB locus. The nt sequence and the deduced amino acid (aa) sequence were aligned with comparable sequences from other organisms and the resulting data bases were used to infer phylogenies. Phylogenetic trees based on aa sequences and nt sequences are similar, but not completely congruent with rRNA gene-based phylogenies. Both the nt and aa sequence trees concur on the early divergence of Thermotoga and Chlamydia from the bacterial root. The aa alignment highlights the presence of four unique Cys residues in the chlamydial sequence which are found at strictly conserved positions in other sequences. Further peculiarities of the chlamydial and eubacterial sequences have been mapped to the X-ray crystallographic structure of the protein.
Amino Acid Sequence↗
Synthesis of a homologous series of ketomethylene arginyl pseudodipeptides and application to low molecular weight hirudin-like thrombin inhibitors.
The design of low molecular weight thrombin inhibitors IIa-d (hirutonins) that bind concurrently with the enzyme's catalytic site and auxiliary "anion-binding exosite" for fibrinogen recognition is reported. A practical synthesis of the required homologous ketomethylene arginyl dipeptide inserts [Arg psi CO(CH2)nCO] (n = 1-4) corresponding to the P1-P1' scissile position of hirutonins is described. The substitution of the scissile amide function by a ketomethylene group is compatible with the enzyme active site and conferred complete plasma proteolytic stability. This modification also enhanced enzyme affinity up to 20-fold with hirutonin-4 (IIb, n = 4) displaying highest affinity (Ki = 140 +/- 20 pM). Hirutonins 1-4 exhibited potent inhibition of plasma prothrombin time (PT) and activated partial thromboplastin time (aPTT). The inhibition was biphasic and showed good correlation with the corresponding Ki. Hirutonin-2 inhibited thrombin-mediated platelet aggregation and exhibited a strong antithrombotic effect comparable to r-hirudin in an in vivo rat arteriovenous shunt model (ED15 = 1.20 mg/kg for hirutonin-2 and 1.14 mg/kg for r-hirudin). Lower molecular weight inhibitors were obtained by substituting the six native amino acid residues (Q-S-H-N-D-G), connecting the active site and the auxiliary exosite binding elements with a variable number of interening omega-aminopentenoyl units. In addition, the exosite component was reduced to seven amino acid residues (D-F-E-P-I-P-L). Incorporation of these modifications into the bifunctional format resulted in nanomolar thrombin inhibitory peptides (IIIa-c). The resulting inhibitors were studied by molecular modeling with alpha-thrombin, and the bimolecular interactions served to explain the retention of high enzyme affinity.
Amino Acid Sequence↗
Comparative effects of a new cardioselective beta-blocker nebivolol and nifedipine sustained-release on 24-hour ambulatory blood pressure and plasma lipoproteins.
This double-blind, parallel-group study compared the effects of nebivolol, a novel cardioselective beta-blocker, with those of nifedipine sustained-release on 24-hour ambulatory blood pressure and plasma lipoprotein levels. After a washout period of 8 weeks, 51 patients with mild to moderate essential hypertension were randomized to double-blind treatment with either nebivolol 5 mg once a day (n = 26) or nifedipine sustained-release 20 mg bid (n = 25) over a period of 12 weeks. Both treatments produced similar and significant (P = .0001) reduction in office blood pressure as well as in 24-hour, work, awake, and sleep ambulatory blood pressure. The clinical response (diastolic blood pressure less than 90 mmHg or decreased by greater than or equal to 10 mmHg) rate was 69% for nebivolol and 59% for nifedipine, respectively. Moreover, the nebivolol and nifedipine treatment-induced decreases in mean 24-hour ambulatory blood pressure were similar to the decreases in clinic blood pressure. Furthermore, the percentages of "blood pressure loads" (awake greater than 140/90 mmHg and asleep greater than 120/80 mmHg) were lowered significantly (P = .0001), from 60% to 29% with nebivolol and from 60% to 39% with nifedipine. Mean ambulatory heart rate was reduced (P = .0001) from 79 +/- 7 to 68 +/- 7 beats/minute during nebivolol therapy and from 80 +/- 9 to 79 +/- 7 (not significant) with nifedipine. Total plasma cholesterol and low-density lipoprotein levels decreased significantly (P less than .05) by 5 and 8%, respectively, after nebivolol treatment, and each decreased by 3% after nifedipine treatment.(ABSTRACT TRUNCATED AT 250 WORDS)
Adolescent↗
Basic fibroblast growth factor (bFGF): mitogenic activity and binding sites in human breast cancer.
We investigated binding characteristics of basic fibroblast growth factor (bFGF) on membranes prepared from 4 human breast cancer cell lines and 38 primary BC biopsies. Competitive binding experiments were performed and analyzed using the "Ligand" program. Furthermore bFGF mitogenic activity was measured by [3H]thymidine incorporation into DNA from breast cancer cell lines. The presence of high-affinity binding sites was demonstrated in each cell type (MCF-7: Kd = 0.60 nM; T-47D: Kd = 0.55 nM; BT-20: Kd = 0.77 nM; MDA-MB-231: Kd = 0.34 nM). The presence of these high-affinity binding sites was confirmed with saturation experiments. A second class of low-affinity binding sites was detected in the 2 hormone-independent cells (BT-20: Kd = 2.9 nM; MDA-MB-231: Kd = 2.7 nM). bFGF stimulated the proliferation of MCF-7, T-47D, BT-20 but not MDA-MB-231 cell lines. With competition experiments, binding sites were detectable in 36/38 breast cancers; high-affinity binding sites (Kd less than 1 nM) were present in 19/36 cases and low-affinity binding sites (Kd greater than 2 nM) were present in 29/36 cases (the two classes of binding sites were present in 12 breast cancers). No relation between bFGF binding sites and node involvement, histologic type or grading of the tumor was evidenced. There were negative correlations (Spearman test) between total bFGF binding sites and estradiol receptor (P = 0.05) or progesterone receptor (P = 0.009). The demonstration of (1) bFGF specific binding sites in breast cancer membranes, and (2) bFGF growth stimulation of some breast cancer cell lines indicates that this factor may be involved directly in the growth of some breast cancers.
Adult↗
Gelation of globular proteins: effect of pH and ionic strength on the critical concentration for gel formation. A simple model and its application to beta-lactoglobulin heat-induced gelation.
The influence of pH (2-9) and ionic strength (0-0.14 M NaCl) on the sol-gel transition of beta-lactoglobulin was investigated in order to determine the critical gel concentration (C0). The concentration necessary to form a gel near the isoelectric pH remains approximately constant (approximately 1% w/v) independently of the ionic strength. At other pH values, the higher the ionic strength is, the lower the protein concentration must be to form a gel. A theoretical model to relate the effect of the intensity and the range of electrostatic interactions on the critical concentration (C0) is proposed and fits reasonably with the experimental results.
Electrochemistry↗
Fatal septicemia due to Mycoplasma arginini: a new human zoonosis.
A 64-year-old slaughterhouse worker with advanced non-Hodgkin's lymphoma developed septicemia and pneumonia. Mycoplasma arginini, a wall-free prokaryote found in a variety of domestic animal hosts, was repeatedly isolated from blood and bronchial washings from the patient. Immunosuppression, in part caused by hypogammaglobulinemia, probably played a key role in predisposing the patient to a fatal infection. This case suggests that animal mycoplasmas should be considered in the list of infectious agents acquired by immunosuppressed hosts.
Bacteremia↗
cAMP effect on extracellular matrix synthesis in human breast cancer cells.
The effect of a cAMP derivative (N6, O2-dibutyryl cyclic adenosine 3',5'-monophosphate: dBcAMP) on the cell cycle and on the synthesis of typical extracellular matrix (ECM) components, i.e. collagen and glycosaminoglycans (GAG), was studied in two hormone-responsive human breast cancer cell lines VHB-1 and MCF-7. The data showed that dBcAMP induced a decrease in the proportion of cells in S + G2 + M phases due to an increase of the non-cycling (G0 phase) cell number as revealed by the Ki-67 antigen immunocytochemical study. The collagen synthesis, estimated by [3H] proline incorporation into the cellular proteins followed by an enzymatic digestion with highly purified bacterial collagenase, was not modified by dBcAMP. In contrast, the GAG synthesis, analysed by [3H] glucosamine incorporation, was increased two-fold in the dBcAMP treated cells. As a comparison we also tested 4-hydroxy-Tamoxifen (4-OH-Tam) since it induces similar cell cycle perturbations as dBcAMP. However, we did not observe a stimulation of the GAG synthesis following 4-OH-Tam treatment. These data demonstrated that the increased GAG synthesis is due to cAMP and is not a consequence of perturbations in the cell cycle. We can therefore assume that the ECM modifications induced by dBcAMP may contribute to the growth inhibition of the hormone-responsive human breast cancer cells.
Breast Neoplasms↗
Specificity of the microimmunofluorescence assay for the serodiagnosis of Chlamydia pneumoniae infections.
Chlamydia pneumoniae infections are mostly confirmed using an indirect microimmunofluorescence test for which potential cross-reactions between antigens from different chlamydial species are not well documented. Using this assay, 928 sera (507 subjects) submitted for Chlamydia pneumoniae serology were tested for specific IgM and IgG to this bacteria using the TW-183 antigen. IgM and IgG reactivities to Chlamydia trachomatis serotypes C, D, E, and L2 and Chlamydia psittaci strain 6BC antigens were also tested. A sample was interpreted as positive only when evenly fluorescent elementary bodies were observed. Twenty-five subjects (4.9%) showed serological evidence of recent Chlamydia pneumoniae infection (IgM positive and (or) IgG seroconversion); 11 of them also showed serological evidence of recent infection with at least one other chlamydial species. Specificity was 50 and 63% for IgM and IgG detection, respectively. These results suggest that mixed or temporally related infections might occur, or, more likely, that some Chlamydia pneumoniae IgM or IgG reactivities might be due to heterotypic antibodies.
Adolescent↗
Normal hemodynamic and coagulation responses to 1-deamino-8-D-arginine vasopressin in a case of lithium-induced nephrogenic diabetes insipidus. Results of treatment by a prostaglandin synthesis inhibitor (indomethacin).
The effect of 1-deamino-8-D-arginine vasopressin (DDAVP) on mean arterial pressure, pulse rate (PR), plasma renin activity (PRA), plasma factor VIIIc and von Willebrand factor were studied in a case of persistent lithium-induced nephrogenic diabetes insipidus (LINDI). 20% decrease in MAP, 22% increase in PR, 100% in PRA, and release of coagulation factors (2- to 3-fold) were noticed after infusion of 0.3 micrograms/kg DDAVP. Urinary prostaglandin (PG) E2 were enhanced. The treatment of this LINDI by PG synthesis inhibitor (PSI) combined with a low osmotic diet (LOD) led to a 51% fall in urine volume, 57% in free water clearance and 75% in sodium clearance. Urinary osmolality rose by 42% but remained low, probably in part because of the LOD. Urinary PGE2 was about one fifth of the initial high value. The results argue for (1) an end-organ resistance to DDAVP confined to the kidneys in LINDI and (2) an effectiveness of indomethacin combined with an LOD.
Adult↗
Prospective trial on captopril-related cough.
OBJECTIVE: Quantify and characterize cough as an adverse reaction secondary to captopril. DESIGN: Cohort analytic study: six-month prospective trial including two-week, placebo, run-in period; five-month, single-blind, active treatment; and two-week, dechallenge period. SETTING: Outpatient clinic. PATIENTS: 199 previously treated or newly diagnosed untreated patients with mild to moderate hypertension. INTERVENTIONS: Captopril 50 mg/d during five months. OUTCOME MEASURES: Self-questionnaires, interviews, dechallenge, and rechallenge periods. Naranjo's algorithm. RESULTS AND CONCLUSIONS: (1) Cumulative incidence of captopril-induced cough over a five-month period was 7.1 percent (95 percent C.I., 6.8-7.4 percent). Incidence of drug withdrawal secondary to severe cough was 1.0 percent; this figure is somewhat similar to first reports about the reaction. (2) Cough was a generally mild to moderate symptom, present day and night in 71.4 percent of patients and resistant to antitussive agents. Cough was not statistically related to sex, age, or smoking habit; however, the female gender and the development of a common cold may be predisposing factors.
Adolescent↗
Estradiol, progesterone and testosterone exposures affect the atrial natriuretic peptide gene expression in vivo in rats.
To clarify the effects of sex hormones on the expression of atrial natriuretic peptide (ANP), ovariectomized and intact female rats were subcutaneously injected with estradiol, progesterone, a mixture of them or olive oil solvent; castrated and untouched male rats were subcutaneously injected with estradiol, testosterone or olive oil, once a day for 7 days. The relative rANP-mRNA contents of rat atrial were measured by molecular hybridization. rANP-cDNA was labeled with 32P as a probe. The results revealed that estradiol and progesterone increased ANP gene expression. Furthermore their effects were associated with administration dose of these hormones and it was shown that they are probably coordinated. The physiological amounts of estradiol and progesterone may maintain suitable levels of rANP-mRNA and androgen may also increase the ANP gene expression in vivo. These experiments suggested that female sex hormone may have a dual purpose in fluid balance.
Animals↗
Cytogenetic and molecular investigations of an abnormal Y chromosome: evidence for a pseudo-dicentric (Yq) isochromosome.
A derivative Y chromosome was found in a 55-year-old man with Lambert-Eaton paraneoplasic pseudomyastheniform disease. Small testicles, azoospermia were noticed and hormonal level values were as in the Klinefelter syndrome. A 45,X/46,XYp+ mosaïcism was described on peripheral blood lymphocytes. Cytogenetic investigations with R-G-C- and Q-banding have been performed. In situ hybridization with the GMGY 10 DNA probe showed two copies of proximal Yp sequences. Southern blot analyses were performed using the Y DNA probes 27a, 47z, 64a7, 50f2 disclosing specific Yp and Yq sequences from the pseudoautosomal boundary to the Yq proximal portion. The der(Y) has been defined as a dicentric isochromosome for the long arm with one active and one apparently suppressed centromere. The breakpoint leading to the der(Y), has been located in the pairing segment of the Y short arm (i.e. Yp11.32). So the der(Y) was interpreted as a psu dic(Y) (qter-->cen-->p11.32 ::p11.32-->qter). There was thus an almost complete duplication of the Y chromosome.
Blotting, Southern↗
[Adenocarcinomatous pleural lesion associated with hypoglycemia].
We report the case of a patient suffering from a glandular pleural lesion. The evolution of the disease was punctuated by periods of hypoglycaemia, which caused a coma. There was no clinically evident explanation for these hypoglycaemic episodes. Investigations revealed adrenal failure, but this adrenal failure was unrelated to the neoplastic process in the patient. This case is a reminder that the cause of hypoglycaemia associated with tumours can really have a paraneoplastic origin and justifies an in depth study to achieve an aetiological diagnosis.
Adenocarcinoma↗
Chlamydia trachomatis cervical infection: prevalence and determinants among women presenting for routine gynecologic examination.
OBJECTIVE: To determine the prevalence of and risk indicators for Chlamydia trachomatis cervical infection among women presenting for a periodic medical examination. DESIGN: Prevalence study. SETTING: Centre local de services communautaires (CLSC) Saint-Louis du Parc, Montreal. PATIENTS: All women presenting for a routine gynecologic examination from May 1985 to July 1986. Of the 773 (99%) who agreed to participate 56 were excluded because of inadequate diagnostic tests (34), antibiotic intake in the preceding 6 weeks (19) or loss to follow-up after the initial visit (3). OUTCOME MEASURES: Culture was the diagnostic standard, but rapid diagnostic tests were also used. From the identified cases logistic regression analysis was used to evaluate the following risk indicators: age, place of residence, use of oral contraceptives, sexual partners and frequency, history of sexually transmitted disease (STD) and abnormalities found on genital examination. MAIN RESULTS: Fifty-one of the women were found to have C. trachomatis infection, for a prevalence rate of 7.1%; 32 (63%) were completely asymptomatic. Three independent indicators were found: age of 25 years or less (odds ratio [OR] 3.2, 95% confidence limits [CL] 1.8 and 5.9), cervical erythema, contact bleeding or mucopurulent exudate (OR 2.5, 95% CL 1.4 and 4.5) and residency in the CLSC area (OR 2.3, 95% CL 1.1 and 5.1). A history of STD or vaginitis had a significant protective effect in women 30 years of age or more (OR 0.2). CONCLUSIONS: Case-finding for chlamydial infection could be an effective public health measure among women 25 years of age or less and among those with signs of cervicitis when they present for a Papanicolaou test.
Adolescent↗
Cyclic AMP stimulation of transferrin secretion by breast cancer cell grown on extracellular matrix or in two-compartment culture chambers.
Extrahepatic synthesis and secretion of transferrin (Tf), the major iron-carrying protein, have been described in normal and tumoral tissues suggesting a potential role for paracrine or autocrine function. In breast tumor cell MCF-7, we have previously shown a Tf secretion stimulated by estradiol which might confer selective growth advantages of these rapidly proliferating cells. The present work refers to possible additional Tf functions related to differentiation of breast tumor cells. We induced MCF-7 cell differentiation by the cyclic AMP derivative, dibutyryl cAMP (dB cAMP) and studied Tf secretion in different culture conditions after labeling with [35S] methionine. Our results demonstrate that dB cAMP stimulates Tf secretion only in culture environment that permits access to the basolateral surface and caters to the polarity requirements of the cell. These results suggest that Tf may also act as a modulator of cellular differentiation in breast cancer cells.
1-Methyl-3-isobutylxanthine↗
Hypothyroidism following combined treatment for hypopharyngeal and laryngeal carcinoma.
The development of hypothyroidism following combined treatment for pharyngeal and laryngeal cancer has received little attention in the literature. We prospectively studied 32 patients over 4 years to determine the incidence of such hypothyroidism and to examine the effect of hemithyroidectomy associated with a combined treatment modality. All patients were men with pharyngeal or laryngeal squamous cell carcinomas and no prior history of thyroid disease. Treatment consisted of radical surgery (30 of 32 patients), followed by postoperative radiotherapy (31 patients). The results of thyroid function tests (free triiodothyronine, free thyroxine, and thyroid-stimulating hormone [TSH]) were all normal preoperatively; tests were repeated every 3 months after treatment. Elevation of TSH values in two successive blood samples was required to make a diagnosis of hypothyroidism. Of 12 patients who underwent hemithyroidectomy as part of total pharyngolaryngectomy and postoperative radiotherapy, 7 became hypothyroid a mean of 6 months after treatment. Twenty patients had similar combined treatment but without thyroid resection. Hypothyroidism developed a mean of 10 months after treatment in only four patients in this group (p less than 0.05). We conclude that hypothyroidism frequently develops following combined treatment for pharyngeal and laryngeal cancer even when thyroid resection has not been performed. Patients should be evaluated postoperatively and carefully monitored by means of serial thyroid function tests.
Carcinoma, Squamous Cell↗
Early hypopituitarism following cavernous sinus thrombosis: total recovery within 1 year.
Hypopituitarism related to cavernous sinus thrombosis is a very rare event which usually occurs at least 1 year after the acute stage. We report a case which distinguished itself from the previously reported cases through (i) its occurrence during the acute stage and (ii) its total recovery within 1 year. Early anterior hypopituitarism is probably more frequent than expected on the basis of reported cases and it may contribute to the high rate of mortality in cavernous sinus thrombosis. This underscores the need to consider hypopituitarism in every patient with cavernous sinus thrombosis.
Adult↗