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Biomedical subjects

M Fournier

Publications and source records attributed to M Fournier.

At least 19 recordsLinked to original sources
PubMed1998

Structural constraints in the HIV-1 reverse transcriptase-primer/template complex for the initiation of DNA synthesis from primer tRNALys3.

The topography and functional implications of the complex formed in vitro between human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) and its primer tRNALys3 were studied in this work. On the basis of previous results showing the high affinity both of the native primer, tRNALys3, as well as that of mismatched short oligonucleotide primers for HIV-1 RT, we synthesized chimeric primers containing tRNALys3 linked to U and T residues of different lengths. We found that the affinity of the oligonucleotide primers for HIV-1 RT is dramatically increased when linked to primer tRNA. Our results also show that in the tRNA.RT complex, before annealing tRNALys3 to the retroviral RNA genome, the 3'-terminal nucleotide of tRNALys3 is positioned at a distance of one nucleotide unit away from the template in the active polymerization site of the enzyme.

Binding Sites↗
PubMed1998

Lack of suppressive effects of mixtures containing low levels of methylmercury (MeHg), polychlorinated dibenzo-p-dioxins (PCDDS), polychlorinated dibenzofurans (PCDFS), and aroclor biphenyls (PCBS) on mixed lymphocyte reaction, phagocytic, and natural killer cell activities of rat leukocytes in vitro.

Rat splenocyte mixed leukocyte reaction (MLR), splenic natural killer (NK) cell activity, and phagocytic activities of splenic, peritoneal, and peripheral blood leukocytes (PBLs) were evaluated in vitro to determine the immunotoxicity of mixtures containing low levels of methylmercury (MeHg), polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and Aroclor polychlorinated biphenyls (PCBs). The mixtures were based on the concentrations of the chemicals in fish flesh. Leukocytes from male Fischer rats were exposed to MeHg (0.1-2 microg/ml), PCDD/PCDF mixtures (1-15 pg/ml) of three PCDDs (2,3,7,8-tetrachlorodibenzo-p-dioxin, 1,2,3,7,8-pentachlorodibenzo-p-dioxin, and 1,2,3,4,7,8-hexachlorodibenzo-p-dioxin) and two PCDFs (2,3,7,8-tetrachlorodibenzofuran and 1,2,3,7,8-pentachlorodibenzofuran), three Aroclor PCB (Aroclor 1242, 1254, and 1260) mixtures (0.01-0.5 microg/ml), or combinations of MeHg/PCB/PCDD/PCDF mixtures for 24 or 72 h before immunological assays. Phagocytosis and NK cell cytotoxicity were evaluated with a flow cytometer, and MLR of Fischer rat responder splenocytes cultured with mitomycin C-treated Long-Evans splenocytes by [3H]thymidine uptake. Exposure to MeHg (2 microg/ml) alone or with PCB/ PCDD/PCDF resulted in significant cytolethality in rat splenocytes, peritoneal leukocytes, and PBLs at 24 h exposure. Treatment with Aroclor PCB mixtures, PCDD/PCDF mixtures, 0.1 microg MeHg/ml (noncytolethal), or PCB/PCDD/PCDF mixtures with 0.1 microg MeHg/ml caused no suppression of splenocyte MLR response, splenic NK cell-mediated lysis of Yac-l cells, or phagocytosis of fluorescent beads by splenic, peritoneal, and peripheral blood phagocytic cells. The results indicate that in vitro exposure of rat leukocytes to low levels of MeHg, Aroclor PCB mixtures, PCDD/PCDF mixtures, or MeHg/PCB/PCDD/PCDF mixtures had no suppressive effects on the immune functions assayed, and thus produced no additive immunotoxicity. However, in order to predict the potential risk of these chemical mixtures to the human immune system, in vivo animal studies with blood (tissue) levels compatible with the levels of MeHg, PCBs, and PCDDs/PCDFs in exposed human populations should be evaluated.

Animals↗
PubMed1998

Increased apoptosis, changes in intracellular Ca2+, and functional alterations in lymphocytes and macrophages after in vitro exposure to static magnetic field.

Electromagnetic-related alteration of cellular functions is well documented for extremely low-frequency low-energy pulsing electromagnetic fields (ELF-EMF). In this study we examined the in vitro effects of static magnetic fields (SMF) on the cellular immune parameters of the C57BI/6 murine macrophages, spleen lymphocytes, and thymic cells. The cells were exposed in vitro for 24 h at 37 degrees C, 5% CO2, to 250-1500 G SMF. Exposure to the SMF resulted in the decreased phagocytic uptake of fluorescent latex microspheres, which was accompanied by an increased intracellular Ca2+ level in macrophages. Exposure to SMF decreased mitogenic responses in lymphocytes, as determined by incorporation of [3H]thymidine into the cells. This was associated with the increased Ca2+ influx in concanavalin A-stimulated lymphocytes. Furthermore, exposure to SMF produced markedly increased apoptosis of thymic cells, as determined by flow cytometry. Overall, in vitro exposure of immunocompetent cells to 250-1500 G SMF altered several functional parameters of C57BI/6 murine macrophages, thymocytes, and spleen lymphocytes.

Animals↗
PubMed1998

Effect of pentachlorophenol on immune function.

The organochlorine compound, pentachlorophenol, was evaluated for effects on immune system function in male Fisher 344 rats. Pentachlorophenol was prepared in an olive oil vehicle and was administered by oral gavage twice weekly for 28 days at a dose of 2.0 mg/kg per treatment. Exposure to pentachlorophenol increased body weight gains (P=0.024) during the treatment period. Liver (P=0.034) and kidney (P=0.012) body weight ratios were also increased. Pentachlorophenol exposure enhanced T-lymphocyte blastogenesis induced by concanavalin A (Con A)(P=0.0001) and phytohemagglutinin (PHA)(P=0.048) evaluated using stimulation indices. Corresponding B-lymphocyte blastogenesis induced by lipopolysaccharide/dextran (LPS/dex)(P=0.0034) was also enhanced by pentachlorophenol exposure. Pentachlorophenol suppressed the antibody response against sheep red blood cells (SRBCs) by 39% when the response was expressed per viable spleen cell (P=0.006). This suppression was not evident when the response was expressed per spleen (P=0.22), suggesting that a compensatory mechanism or extramedullary splenic hemopoiesis was occurring minimizing the overall impact on humoral immunity. The enhanced B- and T-lymphocyte blastogenesis may also reflect compensatory or hemopoietic activity. Pentachlorophenol exposure had no effect on peritoneal macrophage phagocytosis (P=0.31) or lymphocyte cell surface antigen expression. The observed alterations in lymphocyte blastogenesis and humoral immunity subsequent to pentachlorophenol exposure do not appear to be associated with phagocytosis or lymphocyte cell surface antigen expression.

Animals↗
PubMed1998

p66/p51 and p51/p51 recombinant forms of reverse transcriptase from human immunodeficiency virus type 1--interactions with primer tRNA(Lys3), initiation of cDNA synthesis, and effect of inhibitors.

Human immunodeficiency virus type-1 (HIV-1) reverse transcriptase (RT) initiates reverse transcription from tRNA(Lys3). HIV-1 RT is a heterodimer consisting of two polypeptides, p66 and p51. In this work, the possible role of each subunit of RT in the interaction with its natural primer tRNA(Lys3) was studied. Two recombinant forms of HIV-1 RT, heterodimer p66/p51 and homodimer p51/p51, were used. Previously we have expressed and purified recombinant RT p51/p51 which possesses DNA polymerase activity [El Dirani-Diab, R., Andreola, M. L., Nevinsky, G., Tharaud, D., Barr, P. J., Litvak, S. & Tarrago-Litvak, L. (1992) FEBS Lett. 301, 23-28]. Here we show that HIV-1 RT p51/p51 displays certain properties very similar to the p66/p51 recombinant enzyme. The homodimer was able to anneal tRNA(Lys3) to the primer-binding site of the HIV-1 RNA template leading to a functional complex capable of synthesizing cDNA. Further, the p51/p51 enzyme behaved like RT p66/p51 concerning the strong inhibition produced by a non-nucleoside RT inhibitor. These data show that for RT p51/p51, one of the subunits of the homodimer adopts a conformation similar to the catalytic subunit (p66) present in the heterodimeric form. Part of this work was devoted to the study of the complex between the recombinant forms of HIV-1 RT and its primer tRNA. Each enzymatic form was cross-linked to tRNA(Lys3) in the presence of a platinum derivative, giving different ribonucleoprotein complexes of molecular masses higher than 100 kDa, suggesting that primer tRNA may interact with both subunits in the heterodimeric enzyme. After RNase A treatment of the complex RT p66/p51 x tRNA, the label was mainly found to migrate with the p66 subunit, although some cross-linking was also found associated to the p51 subunit. These results show that the p66 and p51 subunits of RT interact with tRNA(Lys3). Moreover, cross-linking of tRNA(Lys3) with HIV-1 RT p66/p51 in the presence of a DNA template containing the primer-binding-site sequence yielded an enzymatically active complex.

Base Sequence↗
PubMed1998

Phagocytic and metabolic activities of macrophages from mummichog naturally exposed to pulp mill effluents in the Miramichi River.

Chemicals present in bleached kraft pulp mill effluents (BKMES) can modulate the immune response of fish. This work was conducted to determine if mummichogs living downstream from a bleached kraft pulp mill (BKM) had an impaired immune response. Head kidney phagocytes from males and females were tested for their phagocytic and metabolic activities. Mummichogs were captured 4 km (S2) and 39 km (S1) downstream from a BKM in the Miramichi estuary (New Brunswick, Canada) and at two sites located upstream (S3) and 20 km downstream (S4) in a reference estuary, the Bouctouche. Both male and female mummichogs captured at S2 in the Miramichi estuary had a lower phagocytic activity, whereas only females from the same site had a decreased oxidative burst response, indicating a difference between sexes in the susceptibility to pollutants present in the Miramichi. Therefore, the results indicate that mummichogs exposed to BKMES have an impaired immune response and that females are more sensitive than males to the chemicals present in BKMES.

Animals↗
PubMed1998

Effects of Great Lakes fish consumption on the immune system of Sprague-Dawley rats investigated during a two-generation reproductive study.

The effects of Great Lakes fish on food consumption, body and organ weights, and hematological parameters were investigated in the first- (F1) and second- (F2) generation Sprague-Dawley rats assigned to immunological studies. The parent- (F0) generation rats were fed either a control diet or diets containing 5 or 20% lyophilized chinook salmon from Credit River (Lake Ontario, LO) or Owen Sound (Lake Huron, LH). The F1 and F2 pups were exposed to the fish diet in utero, through the dam's milk to 21 days of age and through the respective diets to 13 weeks of age. The study included an F1-reversibility (F1-R) phase in which rats at 13 weeks of exposure to fish or control diets were switched to the control diet for 3 months. Statistically significant effects included increased growth rates in the F1 male rats fed the LH fish diets compared to those fed the LO fish diets; increased liver weights in the F2-generation male rats fed the LH-20% and LO-20% diets compared to those fed the 5% fish diets; reduced thymus weights in the F1-R female rats fed the LO-20% fish diet compared to those fed the LO-5% or LH-20% fish diets and in the F2 male rats fed the LO diets compared to those fed the LH diets; increased kidney weights in the F2 male rats fed the LH-20% diet compared to those fed the LH-5% or LO-20% diets; reduced but reversible effects on red blood cell (RBC), white blood cell (WBC), neutrophil, lymphocyte, and monocyte numbers in the F1-generation female rats fed the fish diets; reduced red blood cell (RBC), white blood cell (WBC), and lymphocyte numbers in the F2 male rats fed the LO diets compared to those fed the LH diets; and reduced WBC and lymphocyte numbers in the F2 female rats fed the LO-20% diet compared to those fed the LH-20% fish diet. These results suggested that long-term exposure to Great Lakes fish contaminants may have adverse effects on some immune-related parameters. The impact of such changes on the functional aspects of the immune system of rats and consequently on human health needs to be further investigated.

Animal Feed↗
PubMed1998

Effects of Great Lakes fish consumption on the immune system of Sprague-Dawley rats investigated during a two-generation reproductive study.

The effects of Great Lakes fish contaminants on several quantitative and functional aspects of the immune system were investigated in the first (F1) and second (F2) generations of Sprague-Dawley rats. The F0 rats were fed either a control diet or diets containing 5 or 20% lyophilized chinook salmon from the Credit River of Lake Ontario (LO) and Owen Sound point of Lake Huron (LH). The F1 and F2 pups were exposed to fish in utero, through the dam's milk to 21 days old, and through the dam's respective diets to 13 weeks of age. The study included an F1-reversibility (F1-R) phase in which rats at 13 weeks of exposure to fish or control diets were switched to the control diet for 3 months. The most outstanding finding was a statistically significant increase in absolute spleen leukocytes and absolute and percentage lymphocytes in the F2 male rats fed the LH fish diets compared to the control and to those fed the LO fish diets with the 20% fish diets having higher cell numbers compared to the LO-5% fish diets. A parallel increase in the T-helper/inducer T-lymphocyte subset numbers was observed. Increased but statistically insignificant plaque-forming cell (PFC) numbers were obtained in the F2 male rats fed the LH fish diets compared to those fed the LO fish diets and in the F1-R female group of rats fed the LH fish diet compared to those fed the LO fish diets. Phagocytosis by resident peritoneal macrophages was significantly increased in the F1 male and F2 female rats fed the fish diets compared to the control. The phagocytic activity was significantly higher in the F2-generation male and female rats fed the LO diets compared to those fed the LH diets. Other parameters including lymphocyte transformation in response to mitogens, the number of Listeria monocytogenes bacteria surviving in the rat spleens, and the natural killer cell activity were not affected significantly by any of the treatments. Overall, the effects of diets containing chinook salmon from the LO and LH sources on the immune system of rats were minimal and were on quantitative rather than on functional aspects of the system. Further focused research would be required in order to establish conclusively that the immune system of cohorts who ingest Great Lakes fish frequently is at a greater risk for adverse effects.

Animal Feed↗
PubMed1998

Effects of SR140333, a selective non-peptide NK1 receptor antagonist, on trigemino-thalamic nociceptive pathways in the rat.

Trigeminal stimulation of C-fibers increased c-fos expression within the trigeminal nucleus caudalis (NtV) and thalamic neuronal activity which both reflect the transmission of a nociceptive message. We examined the effects on both these phenomena of the selective NK1 and NK2 receptor antagonists, SR140333 and SR48968. SR140333 (0.3, 1 and 3 micrograms/kg intravenously [i.v.]) dose-dependently, reversibly and stereoselectively antagonized the increase of contralateral thalamic activity. This compound, when given i.v. (30 micrograms/kg) or orally (10 mg/kg), also reduced the number of Fos-like immunoreactive cells particularly at the medial and caudal level of the NtV. In contrast, SR48968 did not exert any antagonistic effect either on thalamic activity or on Fos-like immunoreactivity. The data strongly suggest a preferential involvement of NK1 vs NK2 receptors in nociceptive transmission following trigeminal ganglion stimulation. Taken together, our results indicate that SR140333 could provide a potent drug for the relief of pain occurring under excessive activity of sensory trigeminal fibers.

Administration, Oral↗
PubMed1998

Cellular adaptations of skeletal muscles to cyclosporine.

The aim of this study was to evaluate the cellular response of the diaphragm, extensor digitorum longus (EDL), and soleus (Sol) muscles to clinically relevant doses of cyclosporine administered to male rats over 4 wk. Control rats were provided with vehicle only. Muscle fiber types, cross-sectional areas, indexes of capillarity, and succinate dehydrogenase (SDH) activity were determined by quantitative histochemistry. Myosin heavy chain isoforms were identified by SDS-PAGE, and their proportions were measured by scanning densitometry. Serum cyclosporine level, 20-24 h after the last dose of cyclosporine, was 145 +/- 81 ng/ml. Final body weight and muscle mass were similar between the cyclosporine and control groups. In the diaphragm, EDL, and Sol, no differences were observed between the groups with regard to fiber type proportions, fiber cross-sectional areas, and proportions of myosin heavy chain isoforms. In the EDL, reductions, both in SDH activity in type I, IIx, and IIb fibers (-26 to -37%) and in indexes of capillarity (-18 to -37%), were noted. In the Sol, SDH activity and capillarity were similar between the groups. In the diaphragm of cyclosporine-treated rats, there was significant reduction in the number of capillaries around individual fibers (-5%), whereas levels of SDH activity tended to be lower. This suggests that activation history may in part determine muscle-specific responses to cyclosporine. We speculate that reduced oxidative activity and capillarity of some limb muscles contribute to reduced exercise capacity and the "deconditioned state" observed in patients receiving cyclosporine after successful solid-organ transplantation.

Animals↗
PubMed1998

IGF-I and/or growth hormone preserve diaphragm fiber size with moderate malnutrition.

Resistance to the anabolic effects of growth hormone (GH) occurs with severe caloric deficit. This study examined whether moderate caloric deficit (50% of daily intake for 7 days) in the adolescent rat exceeds a critical threshold for GH action and whether a combination of GH and insulin-like growth factor I (IGF-I) would have enhanced anabolic effects on the diaphragm (Dia). Five groups of rats (4 wk old) were studied: 1) control (Ctl), 2) nutritionally deprived (ND), 3) ND + GH, 4) ND + IGF-I, and 5) ND + GH + IGF-I. IGF-I was given by continuous infusion (200 microg/day). GH was injected subcutaneously (250 microg every 12 h). Contractile and fatigue properties of the Dia were determined in vitro. Quantitative histochemical methods were used to determine Dia fiber type proportions, cross-sectional areas, and succinate dehydrogenase activities. The body weight of Ctl rats increased 46% compared with 7% in ND animals, whereas that of ND rats receiving growth factors was intermediate. Serum IGF-I levels were reduced 54% in ND animals and maintained with the provision of growth factors. Dia fatigue resistance was improved in ND animals receiving growth factors. There were no differences in Dia contractile properties, fiber type proportions, or succinate dehydrogenase activities across groups. ND resulted in atrophy/growth arrest of all Dia fibers (20-32%) compared with Ctl. Administration of IGF-I and/or GH completely prevented atrophy/growth arrest of all Dia fibers. No additive or synergistic effects were noted. We propose that these growth factors may provide useful short-term adjunctive nutritional support in circumstances in which the provision of optimal nutrition may be delayed or inadequate.

Animals↗
PubMed1998

Early release of proinflammatory cytokines after lung transplantation.

BACKGROUND: Systemic hypotension may complicate the early postoperative period after lung transplantation. A release of proinflammatory cytokines secondary to lung ischemia/reperfusion injury could be involved in the pathogenesis of this early hemodynamic failure (EHF). STUDY OBJECTIVE: To assess prospectively whether the occurrence of EHF is associated with a release of cytokines in the systemic circulation. DESIGN: Blood samples were taken daily during the first postoperative week in 26 patients who underwent a double or a single-lung transplantation. These patients were divided into three groups: 7 patients who experienced EHF and subsequently died (EHF group); 15 patients without EHF (control group); and 4 patients without EHF but with an identified sepsis (sepsis group). The serum levels of interleukin (IL)-1beta, tumor necrosis factor-alpha (TNF-alpha), IL-6, and IL-8 were compared among the three groups. RESULTS: In the EHF group, the levels of each cytokine peaked at day 1 postoperatively. Cytokine levels at day 1 were significantly higher in the EHF group than in the control group (p<0.0006) or in the sepsis group (p<0.003 except for TNF-alpha). CONCLUSION: We conclude that EHF is associated with a massive release of proinflammatory cytokines that could play a determinant role in the pathogenesis of this complication.

Adolescent↗
PubMed1998

Predominant androgenic component in the stimulatory effect of dehydroepiandrosterone on bone mineral density in the rat.

In order to assess the relative roles of the androgenic and/or estrogenic components in the stimulatory effect of dehydroepiandrosterone (DHEA) on bone mineral content (BMC) and density (BMD), ovariectomized (OVX) female rats received DHEA administered alone or in combination with the antiandrogen flutamide (FLU) or the antiestrogen EM-800 for 12 months. We also evaluated, for comparison, the effect of estradiol (E2) and dihydrotestosterone (DHT) constantly released by Silastic implants as well as medroxyprogesterone acetate (MPA) released from poly(lactide-co-glycolide) microspheres. Femoral BMD was decreased by 11% 1 year after OVX, but treatment of OVX animals with DHEA increased BMD to a value 8% above that of intact animals. The administration of FLU reversed by 76% the stimulatory effect of DHEA on femoral BMD and completely prevented the stimulatory effect of DHEA on total body and lumbar spine BMD. Similar results were obtained for BMC. On the other hand, treatment with the antiestrogen EM-800 did not reduce the action of DHEA on BMD or BMC. At the doses used, MPA, E2 and DHT increased femoral BMD, but to a lesser degree than observed with DHEA. Bone histomorphometry measurements were also performed. While DHEA treatment partially reversed the marked inhibitory effect of OVX on the tibial trabecular bone volume, the administration of FLU inhibited by 51% (P < 0.01) the stimulatory effect of DHEA on this parameter. The addition of EM-800 to DHEA, on the other hand, increased trabecular bone volume to a value similar to that of intact controls. DHEA administration markedly increased trabecular number while causing a marked decrease in the intertrabecular area. The above stimulatory effect of DHEA on trabecular number was reversed by 54% (P < 0.01) by the administration of FLU, which also reversed by 29% the decrease in intertrabecular area caused by DHEA administration. On the other hand, the addition of EM-800, while further decreasing the intertrabecular space achieved by DHEA treatment, also led to a further increase in trabecular number to a value not significantly different from that of intact control animals, suggesting an additional effect of EM-800 over that achieved by DHEA. Treatment with DHEA caused a 4-fold stimulation of serum alkaline phosphatase, a marker of bone formation, while the urinary excretion of hydroxyproline, a marker of bone resorption, was decreased by DHEA treatment. Treatment with DHEA and DHEA + EM-800 decreased serum cholesterol levels by 22 and 65% respectively, while the other treatments had no significant effect on this parameter. The present data indicate that the potent stimulatory effect of DHEA on bone in the rat is mainly due to the local formation of androgens in bone cells and their intracrine action in osteoblasts.

Androgen Antagonists↗
PubMed1998

Effect of 2,4-dicholorophenoxyacetic acid, trifluralin and triallate herbicides on immune function.

The commercial formulations of 3 commonly used herbicides (the amine salt of 2,4-dichlorophenoxyacetic acid, trifluralin and triallate) were evaluated for effects on immune function in male Fisher 344 rats. The herbicides were prepared in an olive oil vehicle and administered by oral gavage twice weekly for 28 d at the following doses: 10.0 mg 2,4-D/kg; 17.5 mg trifluralin/kg; 5.0 mg triallate/kg/treatment. Normal body weight and organ/body weight ratios indicated the rats tolerated the herbicide treatments without difficulty. Exposure to 2,4-D did not alter lymphocyte blastogenesis, 1 gm antibody production (anti-sheep red blood cell), lymphocyte cell surface marker expression or phagocytic function of peritoneal macrophages. Trifluralin acted as a weak mitogen, but impaired T-lymphocyte blastogenesis induced by phytohemagglutinin and concanavalin A. Other immunological measurements were unaffected by trifluralin exposure. Triallate exposure reduced peritoneal macrophage phagocytosis by 33%, showed weak mitogenic properties and impaired T-lymphocyte blastogenesis in the presence of phytohemagglutin. Triallate also increased the anti-sheep red blood cell response expressed/spleen by 43%, a phenomenon suggestive of a compensatory response to minimize the impact on overall immune function. The changes in lymphocyte or macrophage function due to the herbicide treatments were not associated with changes in lymphocyte cell surface antigen expression.

2,4-Dichlorophenoxyacetic Acid↗
PubMed1998

Effects of corticosteroids on epithelial structure and smooth muscle function of rat trachea.

Corticosteroids, efficient drugs for the treatment of severe asthma, may have numerous side effects. We investigated the effects of 7 days of treatment with triamcinolone (1.2 mg x kg(-1) x day(-1)) on the epithelial structure, tracheal smooth muscle cross-sectional area and contractility in the rat. The corticosteroid-injected rats were compared to pair-fed, and pair-weighed animals. Histological studies were performed on transverse sections of glutaraldehyde-fixed tracheal blocks embedded in plastic. In the preparations taken from corticosteroid-injected, pair-fed and pair-weighed animals, pharmacological stimulation with single (10(-3) M) or cumulative (10(-8)-10(-3) M) concentrations of carbachol (in corticosteroid-injected and pair-fed animals), either inside (In) or outside (Out) of the tracheal lumen, was performed and contractions of the tracheal smooth muscle were recorded. We found that triamcinolone administration: 1) reduced the number of epithelial cells and the tracheal smooth muscle cross-sectional area; 2) induced a decrease in maximal tension (Tmax (g); Out: 2.42+/-0.17, 1.03+/-0.1 in pair-fed and corticosteroid-injected, respectively; In: 2.55+/-0.16, 1.1+/-0.16, respectively) without affecting the sensitivity of the tracheal smooth muscle; and 3) reduced the time required to reach 50% Tmax in carbachol (In) preparations. We conclude that the observed changes resulted from atrophy of tracheal smooth muscle induced by undernutrition and atrophy of tracheal smooth muscle and tracheal epithelium induced by corticosteroid treatment.

Animals↗
PubMed1998

Isolated pulmonary arteries involvement in a patient with Takayasu's arteritis.

Pulmonary arteries involvement is well described in Takayasu's arteritis (TA), a condition which is mainly associated with involvement of the systemic arteries. We report a case of TA with documented isolated pulmonary arteries involvement. Symptoms were quite similar to those encountered in chronic thromboembolic disease. A pulmonary angiogram showed bilateral stenosis and occlusion of pulmonary arteries. Diagnosis of TA was suspected, and as such a complete aortogram was made but proved to be normal. Massive haemoptysis suddenly occurred, which resulted in death. Autopsy disclosed characteristic pathological lesions of TA in pulmonary arteries and confirmed the lack of involvement of the aorta and its branches. The frequency of such a clinical form could be underestimated, given the difficulties of diagnosis and features similar to those of chronic thromboembolic disease.

Adult↗