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Biomedical subjects

C Grondin

Publications and source records attributed to C Grondin.

17 recordsLinked to original sources
PubMed1991

A controlled trial of corticosteroid injections into facet joints for chronic low back pain.

BACKGROUND: Chronic low back pain is a common problem with many treatments, few of which have been rigorously evaluated. This randomized, placebo-controlled trial was designed to evaluate the efficacy of injections of corticosteroid into facet joints to treat chronic low back pain. METHODS: Patients with chronic low back pain who reported immediate relief of their pain after injections of local anesthetic into the facet joints between the fourth and fifth lumbar vertebrae and the fifth lumbar and first sacral vertebrae were randomly assigned to receive under fluoroscopic guidance injections of either methylprednisolone acetate (20 mg; n = 49) or isotonic saline (n = 48) in the same facet joints. Ninety-five patients were followed for six months and their condition assessed with scales of pain severity, back mobility, and limitation of function. RESULTS: After one month, none of the outcome measures evaluating pain, functional status, and back flexion differed clinically or statistically between the two study groups. Forty-two percent of the patients who received methylprednisolone and 33 percent of those who received placebo reported marked or very marked improvement (95 percent confidence interval for the difference, -11 to 28 percentage points; P = 0.53). The results were similar after three months. At the six-month evaluation, the patients treated with methylprednisolone reported more improvement, less pain on the visual-analogue scale, and less physical disability. The differences were reduced, however, when concurrent interventions were taken into account. Moreover, only 11 patients (22 percent) in the methylprednisolone group and 5 (10 percent) in the placebo group had sustained improvement from the first month to the sixth month (95 percent confidence interval for the difference, -2 to 26; P = 0.19). CONCLUSIONS: We conclude that injecting methylprednisolone acetate into the facet joints is of little value in the treatment of patients with chronic low back pain.

Adrenal Cortex Hormones↗
PubMed1986

Immunoregulation of lung fibroblast growth: alteration in asbestos-induced pulmonary fibrosis.

Initial studies on mononuclear cell-fibroblast interactions have shown that stimulated human lymphocytes produced a fibroblast growth inhibitory factor and that asbestos, a fibrogenic dust, interferes with this process in vitro. To investigate the role of these interactions in pathologies characterized by pulmonary fibrosis, we used a rat model of asbestos-induced fibrosis. Rats received a single intratracheal instillation of either saline or 10 mg of chrysotile asbestos fibres. Three months after treatment, peripheral blood mononuclear leucocytes (PBML) supernatant fractions were prepared and their effects on lung fibroblast growth measured. As for human PBML, rat PBML stimulated with Concanavalin A (Con A) produced 24 h after initiation of the cultures a soluble factor which inhibits lung fibroblast DNA synthesis and growth in a dose-dependent fashion. By contrast, Con A-stimulated PBML from rats exposed to asbestos failed to produce significant levels of fibroblast growth inhibitory activity. No significant change of total PBML number or in the proportion of circulating mononuclear cell populations was observed. Furthermore, upon stimulation with lipopolysaccharide (LPS), monocytes from asbestotic animals retained their capacity to produce interleukin (IL-1), a mediator required for lymphokine production. Our study demonstrates that suppression of FGIF production by circulating PBML occurs in animals with lung fibrosis and suggests that mechanisms other than impairment of IL-1 production may be responsible for the suppressive effect of asbestos on the production of such fibroblast regulatory lymphokine.

Animals↗
PubMed1986

Alveolar macrophage stimulation of lung fibroblast growth in asbestos-induced pulmonary fibrosis.

Asbestotic lesions are characterized by macrophagic accumulation, fibroblast proliferation, and collagen deposition. To evaluate the potential involvement of alveolar macrophages in the subsequent fibrogenic reaction, the authors studied the effects of macrophages from normal and asbestos-treated rats upon lung fibroblast proliferation in vitro. Culture supernatants from bronchoalveolar (BAL) cells (99% macrophages) of normal rats stimulated lung fibroblast DNA synthesis and growth in a dose-dependent manner. Fibroblast growth factor (FGF) release by alveolar macrophages (AMs) was rapid (within 1 hour of incubation) and dependent on the number of AMs in culture. Moreover, culture supernatants from BAL cells of animals exposed to asbestos (single intratracheal injection) stimulated fibroblast proliferation to a greater degree than culture supernatants from BAL cells of control animals. Enhanced FGF production occurred 1 week after asbestos instillation and persisted up to 24 weeks. This change was accompanied in the early stages (1-4 weeks) by an increase in the total number of BAL cells which returned to control values by 12 weeks. Differential analysis of BAL cell populations showed a transient infiltration of neutrophils in the bronchoalveolar compartment followed by a significant accumulation of macrophages which persisted up to 1 month. Furthermore, lungs of asbestos-treated animals showed evidence of pathologic alterations characterized by fibroblast proliferation and collagen deposition. This study demonstrates that increased production of fibroblast growth factor by alveolar macrophages in vitro coincides with the development of asbestos-induced fibrosis. Prolonged stimulation of FGF release may contribute to excessive fibroblast proliferation and fibrosis.

Animals↗
PubMed1984

Repeated coronary artery bypass grafting in patients with patent atherosclerotic grafts: a special challenge.

The operative risk and results of reoperations in patients with long-standing atherosclerotic vein grafts are not well-known. We have had 38 such patients among our last 102 cases of repeated revascularization procedure (37.2%). Six out of those 38 patients were operated taking special measures to avoid atheromatous material displacement and they were compared to the remaining 32 operated on in a conventional way. In addition, all patients, as a group, were compared to another 64 patients undergoing the same procedure in the same time interval but presenting either healthy or occluded grafts. Perioperative myocardial infarction was specially studied. It was more frequent in those with atherosclerotic grafts (23.7 % versus 9.4%) and, among them, in those operated on in a conventional way (25% versus 16.7%). Operative mortality was also higher in the same groups: 13.2% versus 3.1% for atherosclerotic versus non atherosclerotic graft carriers and 15.6% versus none of those operated on in a conventional way versus those in whom special measures were taken. The late results so far are also suboptimal in the same risk groups, although a mean follow-up of 6 months is too brief a period of time. We can therefore conclude that patients with patent atherosclerotic vein grafts have a higher operative risk and worse long-term results, mainly related to a greater perioperative myocardial infarction rate. Special measures to avoid the latter event are warranted.

Adult↗
PubMed1979

Clinical and angiographic determinants of early mortality related to aortocoronary bypass surgery.

Clinical and angiographic features were identified that influences early mortality in 807 patients who underwent aortocoronary bypass grafting alone among the first 1000 consecutive patients subjected to aortocoronary bypass operations at the Montreal Heart Institute. The early mortality was 4.7% and was related to the patient's age, the duration of the illness from its first clinical manifestation, certain types of clinical presentation, electrocardiographic findings, the number of obstructed arteries and the ejection fraction. The influence of the number of obstructed arteries appeared to be independent of other factors, including the number of grafts and the degree of correction. Early mortality was not influenced by risk factors such as lipid abnormalities, hypertension or diabetes, by the history of previous myocardial infarction or the number of grafts.

Adult↗