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Biomedical subjects

A M Graulet

Publications and source records attributed to A M Graulet.

10 recordsLinked to original sources

High tumor necrosis factor serum level is associated with increased survival in patients with abdominal septic shock: a prospective study in 59 patients.

BACKGROUND: In several studies including patients with septic shock of various origins, high serum cytokine levels have been reported to correlate with poor outcome. The aim of this prospective study was to assess the prognostic value of cytokine serum levels in a group of patients with perioperative septic shock of digestive origin. METHODS: From January 1992 to December 1994, 59 patients were evaluated (mean age, 68 +/- 15 years). From the first day of septic shock to day 7, blood was drawn every day to measure the conventional biologic parameters (white blood cell count, platelet count, hematocrit, blood urea nitrogen level, serum electrolytes level, pH, blood gases, serum lactate level, coagulation parameters, liver function tests) and tumor necrosis factor (TNF), interleukin-1, and interleukin-6. RESULTS: No difference was observed between the 26 survivors and the 33 nonsurvivors with regard to age, gender, and cause of sepsis. On admission, mean platelet count was significantly higher in the survivors than in the nonsurvivors (260 +/- 142 versus 177 +/- 122 10(9)/L; p = 0.01). Mean blood urea nitrogen level was significantly lower in the survivors than in the nonsurvivors (9.6 +/- 9 versus 12 +/- 7 mmol/L; p = 0.04). No difference was observed between survivors and nonsurvivors for the other conventional biologic parameters and for serum interleukin-1 and interleukin-6 levels. Mean serum TNF level tended to be higher in survivors than in nonsurvivors (565 +/- 1325 versus 94 +/- 69 pg/ml; not significant). In the group survivor 9 (35%) of 26 patients had a serum TNF level greater than 200 pg/ml versus 2 (6%) of 33 patients in the nonsurvivor group (p < 0.02). Survival was noted in 6 (100%) of 6 patients who had both a serum TNF level greater than 200 pg/ml and a platelet count greater than 100.10(9)/L versus 1 (11%) of 9 in patients with neither of these criteria (p < 0.01). CONCLUSIONS: In our patients with abdominal septic shock, high serum TNF levels were associated with increased survival. The high serum level of TNF may reflect the efficacy of peritoneal inflammatory response against abdominal sepsis. Although this possibility must be further explored, a score combining the serum TNF level and platelet count could be helpful for the prognostic assessment of patients with abdominal septic shock.

Abdomen

Bone resorption at the femoral neck is dependent on local factors in nonosteoporotic late postmenopausal women: an in vitro-in vivo study.

Local mediators of bone resorption may be involved in bone loss in recently postmenopausal women and in osteoporosis. In the present study, we investigated the production of cytokines and the formation of osteoclast-like cells in marrow cultures from 16 late postmenopausal nonosteoporotic women (mean age: 66 +/- 8 years; time after menopause: 15 +/- 8 years) undergoing hip replacement for arthrosis. Marrow adherent mononuclear cells (MMNC) isolated from femoral diaphysis marrow were cultured for 10 days in the absence or in the presence of 1,25(OH)2D3. In vivo bone resorption was concomitantly assessed by histomorphometry on femoral neck bone sections. The number of TRAP+ multinucleated cells obtained after 10 days in MMNC cultured in the presence of 1,25(OH)2D3 correlated with the number of osteoclasts measured on the bone femoral neck biopsies (r = 0.65, p < 0.01), suggesting that the formation of multinucleated cells in vitro could reflect the osteoclast differentiation in vivo. Furthermore, the number of osteoclasts was related to the eroded volume and the trabecular separation of the femoral neck bone biopsies. Finally, the release of interleukin-1 (IL-1), IL-6, and TNF-alpha by cultures of peripheral blood mononuclear cells (PBMC) and MMNC was measured by radioimmunoassay. The cytokine levels of basal and 1,25(OH)2D3-treated MMNC decreased from days 2 to 5 and then reached a plateau to day 10. The number of TRAP+ multinucleated cells obtained after 10 days in MMNC cultures correlated with the basal IL-6 release in the same cultures determined at day 2 (r = 0.55, p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon

Cytokine-mediated bone resorption in patients with the hyperimmunoglobulin E syndrome.

Hyperimmunoglobulin E syndrome (HIES) is a rare immunodeficiency disorder characterized by increased serum immunoglobulin E levels. Bone fragility is part of this syndrome, which has recently been reported to be also associated with an imbalance in cytokine-secreting lymphocyte subpopulation. It has recently been shown that some cytokines can play a role in the bone fragility following menopause. We therefore investigated six patients (mean age 16.5 +/- 8.5 years) affected by this rare syndrome in order to study their bone remodeling and the possible involvement of cytokines in causing the bone fragility associated with this disease. Three of six patients had suffered long bone fractures; in four of six patients the cortical bone mass measured at the distal radius was two standard deviations below that of the aged-matched controls. Urinary pyridinoline excretion, a marker of bone resorption, was markedly increased in the two youngest patients. Adherent mononuclear cells derived from these patients were cultured in vitro and the bone resorbing activity (BRA) of the culture supernatant was measured by means of a fetal rat long bone assay. The BRA was up to 28% above the basal value. We compared the BRA and the cytokine production by the mononuclear cells of these patients to that of postmenopausal women. The BRA, and the IL1 beta, IL6, and TNF alpha levels in the mononuclear cell culture supernatants were identical for both HIES and postmenopausal women. However, the levels of PGE2 were higher and the levels of interferon-gamma were lower in the HIES patients. In conclusion, increased bone resorption in young patients with the HIES is responsible for the cortical bone loss that leads to a higher incidence of fractures. The high BRA secreted by the mononuclear cells of these patients is similar to that found in mononuclear cells from postmenopausal women. These data provide evidence of potent mononuclear cell activation leading to bone loss in HIES, which could be related to IgE-dependent mechanisms.

Adolescent

1,25 dihydroxyvitamin D and dexamethasone decrease in vivo Walker carcinoma growth, but not parathyroid hormone related protein secretion.

Parathyroid hormone related protein (PTHrP) is produced by several breast cancers. 1,25 dihydroxyvitamin D (1,25[OH]2D) and Dexamethasone (DEX) have been shown to decrease PTHrP mRNA expression in several cell lines. We therefore tested the in vivo effect of both steroids on PTHrP secretion and tumor development of the Walker carcinoma (WC). WC cells were injected subcutaneously in Fisher rats which were simultaneously treated with either vehicle, or 1,25(OH)2D (0.5 micrograms/kg/d) or DEX (2 mg/kg/d). After 7 days, tumor weight was significantly decreased in the 2 treated-groups as compared to the control group. Vehicle treated-rats developed hypercalcemia, which was also observed in rats treated with 1,25(OH)2D; by contrast, the plasma calcium was significantly decreased in the DEX-treated group compared to vehicle-treated rats. In a dose-effect experiment, this dose of 1,25(OH)2D induced marked hypercalcemia in rats not implanted with WC, but was required to decrease the tumor weight in implanted rats. In both 1,25(OH)2D and DEX-treated groups, plasma PTHrP levels were significantly decreased, but there was a similar correlation between PTHrP plasma level and tumor weight in the three groups. Indeed, the cytosolic PTHrP content/mg tumor was identical in the 3 groups. By contrast, the PTHrP/Actin mRNA in the tumor was significantly decreased in the 1,25(OH)2D group, comparatively to the vehicle and DEX groups. Our results show that Dexamethasone and 1,25(OH)2D decrease WC tumor development in vivo, but do not change the PTHrP secretion by the remaining tumor although steady state PTHrP mRNA content level is decreased by 1,25(OH)2D.

Animals

In vitro production of cytokines by bone surface-derived osteoblastic cells in normal and osteoporotic postmenopausal women: relationship with cell proliferation.

To evaluate the role of cytokines produced by osteoblasts in the pathophysiology of bone lesions in postmenopausal osteoporosis (PMOP), we have determined by RIA and immunoradiometric assays the levels of prostaglandin E2 (PGE2), interleukin-1 beta (IL-1), tumor necrosis factor-alpha (TNF alpha), and IL-6 released by cultured bone surface-derived osteoblastic (OB) cells isolated from 24 untreated PMOP women with high, low, or normal bone turnover on bone biopsy. OB cells isolated from patients with high bone formation had a 2-fold increased proliferation rate in vitro compared to OB cells from patients with normal or low bone formation or OB cells from age-matched controls. The spontaneous in vitro production per cell protein of PGE2, IL-1, and TNF alpha, but not of IL-6, was 2- to 3-fold lower in rapidly proliferating OB cells isolated from PMOP patients with high bone formation compared to OB cells from patients with normal or low proliferation or control cells. Treatment with 10 nmol/L 1,25-dihydroxyvitamin D (48 h) increased PGE2 levels to normal values in OB cells with a high proliferation rate, but decreased PGE2 production in cells with low proliferation and in control cells, suggesting that the release of PGE2 was dependent on the stage of maturation of OB cells. Significant correlations were found between IL-1 and TNF alpha (r = 0.87; P < 0.001), IL-1 and PGE2 (r = 0.46; P < 0.05), IL-6 and IL-1 (r = 0.39; P < 0.05), and IL-6 and TNF alpha (r = 0.49; P < 0.05), suggesting that the production of these cytokines was under reciprocal control. The results indicate that the in vitro production of PGE2, IL-1, and TNF alpha, but not IL-6, by OB cells isolated from patients with PMOP is related to the proliferation rate of these cells and the rate of bone formation. The variable production of cytokines by OB cells may contribute to the histological heterogeneity of bone formation in PMOP.

Aged

Peripheral monocyte culture supernatants of menopausal women can induce bone resorption: involvement of cytokines.

Increased bone resorption is a mechanism contributing to bone loss in the postmenopausal period. Cytokines are involved in osteoclastic differentiation and, therefore, may play a role in the regulation of bone resorption. Several previous works showed the implication of interleukin-1 (IL-1), IL-6, and tumor necrosis factor-alpha (TNF alpha) in the modulation of bone remodeling. This study determines the concomitant production of the three cytokines and tests the bone-resorbing activity of peripheral monocyte supernatants. Four groups of women were studied: premenopausal women (n = 13; mean age, 47 +/- 0.9 yr), untreated postmenopausal women (n = 21; mean age, 52 +/- 0.6 yr), postmenopausal women treated with estrogens (n = 14; mean age, 54.2 +/- 1.1 yr), or postmenopausal women treated with ethanehydroxydiphosphonate (n = 12; mean age, 53.2 +/- 2 yr). Assignment to clinical groups was verified by plasma FSH and estradiol determinations. Lumbar spine bone mineral density was significantly higher in the premenopausal women group than in the three postmenopausal groups. Peripheral blood monocytes were cultured for 48 h with 20% autologous plasma, and after stimulation with lipopolysaccharides. IL-1, IL-6, and TNF alpha levels were measured by RIA in the monocyte surpernatants. The three cytokines were highly correlated to each other, IL-1 with IL-6 (r = 0.76; P < 0.001), IL-1 with TNF alpha (r = 0.89; P < 0.001), and IL-6 with TNF alpha (r = 0.89; P < 0.001). The mean levels of the three cytokines could not be compared because of the variations in the values. However, a trend toward lower levels in the three cytokines was noted in estrogen-treated women compared to the untreated postmenopausals. The bone-resorbing activity of monocyte supernatants, assessed by fetal long bone-resorbing assay, increased in untreated postmenopausal compared to that in premenopausal women (1.22 +/- 0.08 vs. 0.87 +/- 0.11; P < 0.05). In estrogen-treated patients, this activity decreased to premenopausal levels (0.89 +/- 0.04 vs. 0.87 +/- 0.11; P = NS). The resorbing activity was correlated to IL-1 (r = 0.28; P = 0.03), IL-6 (r = 0.52; P < 0.01), and TNF alpha (r = 0.48; P < 0.01). The addition of cytokine inhibitors and IL-1 receptor antagonist and TNF alpha antibodies to the supernatant bone culture medium induced a significant decrease in the calcium release. Those data show the involvement of several cytokines in the bone resorption process after estrogen deficiency.

Bone Resorption

The resistance to parathyroid hormone of fibroblasts from some patients with type Ib pseudohypoparathyroidism is reversible with dexamethasone.

Skin fibroblasts from some patients with pseudohypoparathyroidism type Ib (PHP-Ib) are resistant to PTH. To characterize the defect producing PTH resistance in these cells and determine whether the abnormality is potentially reversible, we evaluated the ability of fibroblasts from patients with PHP-Ib to produce cAMP in response to PTH both before and after exposure to dexamethasone, an agent known to increase PTH responsiveness in other cell types. Before dexamethasone treatment, fibroblasts from five of eight patients with PTH-Ib produced reduced amounts of cAMP in response to PTH (but not prostaglandin E1 and forskolin) compared to that of control cells (6.3 +/- 1.0 and 37.3 +/- 6.3 pmol cAMP/100 micrograms protein, respectively). Whereas dexamethasone pretreatment had no effect on cAMP production by control or PTH-responsive PHP-Ib fibroblasts, it resulted in a dose-dependent increase in PTH-induced cAMP production by PTH-resistant fibroblasts to normal levels in four of five cases. Studies evaluating the binding of radiolabeled PTH did not permit quantification of the small number of high affinity PTH receptors present on these cells. We conclude that PTH resistance in PHP-Ib patients with PTH-resistant fibroblasts results from an abnormality in the expression of or coupling to cyclase of high affinity PTH-receptor complexes. Because it is expressed in only some tissues and is reversible, the defect could be regulatory in nature.

Adult

Optimal correction of acidosis changes progression of dialysis osteodystrophy.

To investigate an eventual role of acidosis on hemodialysis osteodystrophy we prospectively studied 21 patients who were dialyzed with different amounts of bicarbonate in the dialysate for 18 months. According to the level of bone formation rate (BFR) on a prestudy bone biopsy, patients were split in two subgroups. Inside these two subgroups patients were randomly allocated to two therapeutics groups: 10 patients (group A) were dialyzed with the conventional amount of bicarbonate (33 +/- 2 mmol/liter) in the dialysate; the rest of the patients (group B, N = 11) had 7 to 15 mmol/liter sodium bicarbonate added to the dialysate to obtain 24 mEq predialysis bicarbonate plasma levels. An effective correction of acidosis was shown in group B by a higher predialysis plasma bicarbonate level (15.6 +/- 1 group A vs. 24.0 +/- 0.6 mEq/liter group B, P less than 0.005), which was reached three months after start of the study. Compared to the prestudy bone biopsy, osteoid and osteoblastic surfaces increased in group A but not in group B on the bone biopsies performed at the end of the study. Parathormone plasma level (iPTH), measured with an antiserum which cross reacts with the 44-68 region of PTH molecule, increased during the study in group A but not in group B. This finding suggested progression of secondary hyperparathyroidism (HPT) only in group A patients. Osteocalcin plasma values increased in both groups during the 18 months of the study. Consequently the two subgroups of patients formed on the basis of BFR level were evaluated separately.(ABSTRACT TRUNCATED AT 250 WORDS)

Acidosis

Relationships between histomorphometric features of bone formation and bone cell characteristics in vitro in renal osteodystrophy.

To determine whether abnormal bone cell recruitment or differentiation may be involved in the development of aplastic bone lesion in renal osteodystrophy we have compared histomorphometric parameters of bone formation and in vitro behavior of osteoblastic cells isolated from the trabecular bone surfaces in 37 dialysis patients with osteitis fibrosa, normal bone formation rate, or aplastic bone lesion. The bone cell responses to human PTH-(1-34) (20 nmol/L), as evaluated by intracellular cAMP production, and to 1,25-dihydroxyvitamin D (10 nmol/L), as assessed by osteocalcin synthesis, were not different from normal in patients with low, normal, or high bone formation rates. Osteoblastic cells isolated from patients with a high bone formation rate and markedly elevated serum iPTH and osteocalcin values had a higher than normal DNA replication in primary culture. The peak of [3H]thymidine incorporation, the maximal DNA synthesis, and the area under the growth curve were 4.4- to 6.3-fold increased in osteitis fibrosa compared to those in normal bone cells obtained from age-matched individuals. By contrast, [3H]thymidine incorporation in bone cells from aplastic patients was about 25% of normal and only 5% of the value in osteitis fibrosa. The decreased DNA replication of cultured bone cells in aplastic patients was unrelated to trabecular bone aluminum staining, but was associated with low serum immunoreactive PTH values compared to those in other groups of patients. These results show that high bone formation in uremic osteoitis fibrosa is associated with higher than normal [3H]thymidine incorporation in bone cells in vitro, whereas low bone formation in aplastic patients results from lower than normal DNA replication and suggest that the defective osteoblastic recruitment in aplastic patients may be related to factors other than aluminum, including inappropriate PTH secretion.

Biopsy