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Biomedical subjects

M Renoux

Publications and source records attributed to M Renoux.

At least 37 records · Page 2Linked to original sources
PubMed1994

Evaluation of carboplatin as a single agent in highly refractory acute myeloid leukemia.

Thirteen patients (pts) with highly refractory acute myeloid leukemia (AML) 10 pts with de novo AML and 3 with blast crisis of chronic myeloid leukemia were treated with carboplatin (CP) 150 mg/m2/day through continuous IV infusion for 7 consecutive days. Seven of them received CP at least as third or more line therapy after a median duration of the disease of 26 weeks. None achieved a complete remission but a good hematologic response, with disappearance of circulating blast cells along with correction of bone marrow failure, persisting for 3 months was obtained in one patient and correction of hyperbasophilemia was observed in another with blast crisis of chronic myelogenous. Myelosuppression was the most consistent toxic effect. Two deaths occurred, one from renal acute failure and the other from sepsis. Median survival after CP was 8 weeks (range 4 days-11 months) and the majority of patients were able to return home. When used as a single agent and with the dose-schedule used in this study, CP does not appear effective in refractory AML. Other studies are necessary to assess its role at an higher dose or in combination with other agents in earlier phases of the disease.

Acute Disease↗
PubMed1994

[Paget disease, complicated by Ki-1 lymphoma with G-CSF growth factor secretion].

Development of lysis within an area of pagetic bone suggests a sarcoma. We report the case of a 61-year-old woman who had increasingly severe pain in her right hip and a decline in general health. The roentgenogram of the pelvis showed previously known pagetic lesions of the right half of the pelvis and osteolysis of the roof of the acetabulum. Additional imaging studies (ultrasonography, computed tomography, and magnetic resonance imaging) disclosed a pelvic tumor extending on either side of the right ilium. The peripheral white blood cell count was markedly elevated (93,000/mm3) as a result of inappropriate secretion of granulocyte-colony-stimulating factor. The tumor was an anaplastic large cell lymphoma of T-cell origin with CD30 positivity, i.e., a Ki-1 lymphoma. Most CD30-positive lymphomas are high-grade tumors. There has been only one previous report of Ki-1 lymphoma with production of granulocyte-colony-stimulating factor and hyperleukocytosis. It has been suggested that cytokines may influence tumor growth. Unusual features in our case include development of the Ki-1 lymphoma in an area of pagetic bone and presence of a leukemic syndrome due to increased production of a growth factor.

Bone Neoplasms↗
PubMed1993

Substance P levels in the synovium and synovial fluid from patients with rheumatoid arthritis and osteoarthritis.

Experimental results suggest that substance P (SP) may play an important role in pain and inflammation in rheumatic diseases. Measurements of SP-like immunoreactivity (SPLI) were performed in synovial fluid (SF) and synovial tissue from 40 patients with rheumatoid arthritis (RA) or osteoarthritis (OA). High levels of SPLI were found in the SF of patients with RA compared with OA. Conversely, SPLI content in synovial tissue was higher in OA than in RA, suggesting that there is an active secretory process of SPLI into the SF in RA, thus depleting SPLI stores in the synovium. Our data support the involvement of SP in the perpetuation and exacerbation of inflammation in RA, and may also explain some clinical features of this disease.

Adult↗
PubMed1993

[Paraparesis of lower limbs caused by apophyseal joint cyst].

A case of paraparesis due to an apophyseal joint cyst is reported. Full recovery occurred following surgical removal of the cyst. A review of the literature found approximately 60 cases of nerve root pain due to a synovial apophyseal joint cyst. Only very few patients had neurological loss. Facet joint cysts must be differentiated from spinal tumors. Computed tomography and above all magnetic resonance imaging provide valuable diagnostic and therapeutic information.

Adult↗
PubMed1993

Uptake of technetium-99m-teboroxime in cultured myocardial cells: comparison with thallium-201 and technetium-99m-sestamibi.

The effects of metabolic inhibition on the uptake of 99mTc-teboroxime were assessed in cultured myocardial cells and compared with 201Tl and 99mTc-sestamibi. Metabolic impairment was induced by cyanide (CN), a blocker of the mitochondrial respiratory chain, iodoacetate (IAA), an inhibitor of the glycolytic pathway, and ouabain, an inhibitor of Na(+)-K+ sarcolemmal ATPase. Cellular viability was appreciated by the trypan blue exclusion method. The effects of low temperature and of cellular death resulting from osmotic lysis were also assessed. Net cellular uptake of the radiotracers and the amount of proteins in the culture dishes were measured. All experiments were performed in parallel with control conditions and the results were expressed relatively to the control values. Teboroxime uptake was clearly decreased at low temperature (29.6% +/- 2.2% at 0 degree C, p < 0.001), while metabolic inhibition or osmotic lysis had no definite effect. The uptake of 201Tl and sestamibi was severely diminished in the presence of a mixture of 5 mM CN and 0.1 mM IAA, but 201Tl was less resistant than sestamibi (13.7% +/- 0.3% and 73.5% +/- 3.3%, respectively, after 1 hr of preincubation, p < 0.001 for both). Uptake of both tracers was very low in the presence of dead cells (12.1% +/- 1.3% for 201Tl and 4.1% +/- 0.2% for sestamibi, p < 0.001 for both). Ouabain had a detrimental effect only on 201Tl uptake at doses higher than 100 microM. Of these three currently available coronary blood flow imaging agents, teboroxime shows the lowest sensitivity to metabolic impairment.

Animals↗
PubMed1992

[Candida tropicalis arthritis of the shoulder associated with articular chondrocalcinosis].

A case of infection of the scapulohumeral joint following articular infiltrations is reported in a female patient with alcohol-related cirrhosis of the liver. Joint destruction occurred despite appropriate treatment with fluconazole. Candida tropicalis joint infections are seen mainly in immunocompromised hosts and usually cause little destruction of the joint. Most are the result of dissemination via the bloodstream. Preexisting chondrocalcinosis in the patient reported here may have been a contributing factor to the development of extensive joint destruction.

Aged↗
PubMed1991

Paradoxal pharmacologic effects observed with beta-blocker agents on cardiac cells in culture.

The direct effects of propranolol and metoprolol were studied on cultured neonatal rat ventricular myocytes by recording cellular contraction with a video signal analyzer of cells movements. The experiments were performed on 3-d-old cultures forming a synchronously beating monolayer. The spontaneous beating frequency of preparations depended on cultures and varied from 100 to 330 beats/min with a peak for the interval 140 to 149 beats/min. Propranolol and metoprolol were tested at 1, 5, 10 microM and 10, 50, 100 microM, respectively. At these doses the two beta-blockers induced chronotropic and inotropic effects in the same range. The two agents induced rapid and short-lasting negative inotropic effects, which were dose-dependent and delayed negative chronotropic effects even with the lowest doses. In some preparations paradoxal effects were evidenced: an increase of the amplitude or frequency of the contractions was observed. The results obtained with 5 microM propranolol or 50 microM metoprolol could be separated in two groups depending on the basal beating rate (less than or greater than to 150 beats/min). In cultures with a rapid frequency, the drugs had a marked negative chronotropic effect and, surprisingly, a positive inotropic effect was observed. These findings confirm the interdependence of the two parameters frequency and amplitude of contraction on this model, and evidence the interest of taking into account the control parameters before any interpretation.

Adrenergic beta-Antagonists↗
PubMed1989

Role of the N-terminal arginine in the histamine-releasing activity of substance P, bradykinin and related peptides.

A series of substance P (SP)- and bradykinin (BK)-related peptides have been compared for their histamine-releasing activities on rat peritoneal mast cells. Some of these peptides only differed in the N-acetylation of the N-terminal arginine residue or by the removal of charged residue at the N-terminal. The aim was to examine the role of the N-terminal positive charges in the histamine-releasing activity of compounds that are selective for the SP receptor (named NK-1) or for the B2 type bradykinin receptor. Only compounds with positive charges at the N-terminal caused non-cytotoxic histamine release from rat mast cells. It is suggested that SP- and BK-related peptides caused histamine release by a mechanism which appeared to be non-specific and not related to the activation of mast cell NK-1 or B2 receptors, respectively. Our results show that NK-1 agonists or B2 antagonists devoid of histamine-releasing activity, which could be of potential use in the clinic, can be obtained by removing the positively charged N-terminal aminoacids or by N-acetylation of the N-terminal arginine.

Animals↗
PubMed1989

Sodium diethyldithiocarbamate protects against the MPTP-induced inhibition of immune responses in mice.

The effects of 1-methyl-4-phenyl - 1,2,3,6-tetrahydropyridine (MPTP) on immune parameters, and the restorative influence of sodium diethyldithiocarbamate (DTC) or deprenyl were evaluated in mice. The concentrations of dopamine (DA), 3-methoxytyramine (3-MT), 3-4-dihydroxyphenyl acetic acid (DOPAC), and homovanillic acid (HVA), were concomitantly measured in the striatum. MPTP depressed T-cell responses. DTC restored these responses as well as the concentration of striatal DA. Deprenyl had no effect on the concentrations of DA and its metabolites, yet it modified the immune responses alike MPTP. The findings suggest a dopamine pathway could be involved in the brain-controlled immunostimulation afforded by DTC.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1989

Interleukin-1 secretion by lipopolysaccharide-stimulated alveolar macrophages. Relationships to cell numbers--influence of smoking habits.

Interleukin-1 (IL-1) release by alveolar macrophages (AMs) from 29 patients with primary bronchogenic carcinoma, lung metastases, acute pneumonitis, and chronic infection was evaluated in response to a standard stimulus, lipopolysaccharide (LPS). The results were compared to those of AMs from normal smokers or nonsmokers (volunteers). AMs derived from healthy smokers secreted significantly more IL-1 than AMs from nonsmokers. In contrast, AMs from smokers affected with primary lung cancer have lost their capacity of secreting high levels of IL-1, whereas IL-1 secretion was high in nonsmokers with hematogenous metastases. AMs release high IL-1 levels in patients with acute bacterial infections. A significant correlation exists between numbers of AMs and IL-1 levels in normal individuals, a relationship which disappears in patients. These observations suggest that AMs in inflammatory lung disease, even discrete, have an increased capacity to secrete IL-1 on stimulation with LPS. They also suggest that an intrinsic dysfunction of AMs may accompany primary bronchogenic carcinoma. The influence of tobacco in modifying the functions of AMs is stressed.

Adult↗
PubMed1989

Histamine-releasing activity of endogenous peptides on mast cells derived from different sites and species.

We have examined the cytological and functional characteristics of mast cells grown in tissue culture from the bone marrow of mice and rats and compared them with mast cells isolated from the peritoneal cavity of these animals. In both species, bone marrow-derived mast cells (considered to be a model of mucosal mast cells) have fewer cytoplasmic granules and lower histamine content than peritoneal mast cells. Sprague-Dawley rat peritoneal mast cells were responsive to various endogenous peptides and to compound 48/80. However, peritoneal mast cells isolated from BDF1 mice (a strain widely used to obtain bone marrow-derived mast cells) were not responsive to the same secretagogues. Rat and mouse bone marrow-derived mast cells obtained from Sprague-Dawley rats and BDFI1 mice were also hyporesponsive to calcium ionophore as compared to peritoneal mast cells and unresponsive to compound 48/80 and peptides. Despite the similarity of the functional characteristics of mouse and rat bone marrow-derived mast cells, mouse bone marrow-derived mast cells could not be used as a model of responsiveness to peptides for rat mucosal mast cells because of the differences in responsiveness between the peritoneal mast cells in the two species. Obtention of homogeneous rat bone marrow-derived mast cells may provide a useful tool to study the functional heterogeneity in an intraspecies system since most of our knowledge on mast cell physiology and pharmacology is derived from studies on rat peritoneal mast cells.

Animals↗