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Biomedical subjects

D Donati

Publications and source records attributed to D Donati.

At least 109 records · Page 6Linked to original sources
PubMed1992

Effects of hemodialysis on activation of lymphocytes: analysis by an in vitro dialysis model.

Patients undergoing maintenance hemodialysis have impaired immune responsiveness, which appears to deteriorate progressively with the duration of the replacement treatment. It has been suggested that it is caused by a chronic preactivation state of T cells caused by hemodialysis. Each treatment session has been compared with a recurring "acute-phase" inflammatory reaction. In this study, the acute effects of hemodialysis on the activation state and functional responsiveness of normal peripheral blood mononuclear cells have been evaluated by use of an in vitro dialysis model. The dialysis was carried out with either cuprophan or polysulfone membranes, with or without sodium acetate in the dialysis fluid. It was observed that a single session of in vitro dialysis did not induce production of interleukin-2 (IL-2) and did not alter the expression of IL-2 receptor (IL-2R) on the cytoplasmic membrane and the secretion of soluble IL-2R, whereas it induced transcription of mRNA for IL-2R. The proliferative response of lymphocytes to phytohemagglutinin or IL-2 in vitro also did not change after a single dialysis session. There was only a slight decrease of the release of soluble IL-2 receptor by phytohemagglutinin-stimulated cells after dialysis. Dialysis induced an active synthesis of IL-1 by peripheral blood mononuclear cells, even in the absence of sodium acetate in the dialysate bath, but there was no release of IL-1 to the circulating medium. The results show that a single dialysis encounter can acutely prime the activation of human peripheral blood mononuclear cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗
PubMed1992

Osteoblastoma of the spine.

Osteoid osteomas and osteoblastomas have similar histologic characteristics, although their clinical course in the spine may be significantly different. At the authors' institution, spinal osteoblastomas constituted 46% (30/65) of all osteoblastomas treated. Sixteen of the lesions occurred in the lumbar spine (53%), eight in the thoracic spine, and six in the cervical spine. In all regions of the spine, the posterior elements and pedicles were more frequently involved than the vertebral body. Twenty patients had pain or other symptoms for more than 12 months before diagnosis. Six of eight patients had thoracic lesions that demonstrated neurologic involvement. Twelve patients presented with painful scoliosis. Fourteen patients had lesions with well-circumscribed margins confined within the vertebral structure (Enneking Stage 2), and 16 had ill-defined margins with soft-tissue extension (Enneking Stage 3). Well-defined lesions were treated with curettage, with excellent results in 12 of 14 patients. The more extensive lesions were treated by intralesional excision (15/16) and adjuvant radiation therapy (9/16).

Adolescent↗
PubMed1991

Radiographic evaluation of achalasia immediately after pneumatic dilatation with the Rigiflex dilator.

Radiographic evaluation of the lower esophagus was done immediately after pneumatic dilatation using the Rigiflex dilator in 34 patients (24 men, 10 women; mean age, 55 years) with achalasia. The dilator was positioned across the esophagogastic junction using fluoroscopy and the balloon was inflated for 1 min. The esophagus was intubated and injected sequentially with water-soluble and barium contrast materials. Radiographic analysis included changes in the appearance of the caliber and contour of the esophagogastric junction, rate of esophageal emptying, and presence of complications. In 23 patients with predilatation esophagrams, the mean esophagogastric junction caliber increased from 4.7-7.6 mm following dilatation. The postdilatation esophagrams in 33 patients showed a smooth contour in 22 (67%) and immediate esophageal emptying in 26 (79%). Esophageal perforation occurred in one (3%) patient and intramural hematoma in one (3%). Clinical follow-up (mean, 7 months) was available in 29 patients and 23 (79%) had symptomatic improvement. Five of the six patients who did not improve clinically all had previous Heller myotomy, pneumatic dilatation, or both.

Catheterization↗
PubMed1991

Phase I clinical trial of an acellular pertussis vaccine composed of genetically detoxified pertussis toxin combined with FHA and 69 kDa.

An acellular pertussis vaccine composed of genetically detoxified pertussis toxin (PT-9K/129G), filamentous haemagglutinin (FHA) and pertactin (69 kDa protein) was evaluated in adult volunteers, in double blind, versus placebo. No fever was reported in either group. Mild local reactions were reported after injection of both vaccine and placebo. After the first dose a marked increase in antibodies to PT, FHA and 69 kDa protein was seen in vaccinated subjects with the exception of one who responded well to PT and FHA but did not show a humoral response to the 69 kDa protein. All vaccinees acquired cellular immunity against the three antigens. No significant variation was observed in the humoral or cellular responses after the second dose.

Adhesins, Bacterial↗
PubMed1991

Production and kinetics of interleukin-1 in hemodialysis. In vivo and in vitro study.

Interleukin-1-beta (IL-1-beta) was measured in the plasma and peripheral blood mononuclear cell lysates of uremic patients undergoing maintenance hemodialysis by means of either cuprophane or polysulfone membranes. Basal plasma levels of IL-1-beta in hemodialyzed patients were strikingly higher than those of uremic patients on conservative treatment or of healthy subjects. Plasma levels of IL-1-beta in uremic patients increased significantly after 3 and 6 months of hemodialysis. The study of the kinetics of IL-1-beta concentration during a single hemodialysis session revealed that the concentration of IL-1-beta fell to 21 and 22% of the predialysis level with cuprophane and polysulfone, respectively. Hemodialysis patients also had a significantly higher intracellular IL-1-beta level than normal controls. During the hemodialysis session, an increase in cell-associated IL-1-beta was seen regardless of the membrane employed. In a parallel study, normal mononuclear cells were subjected to closed-loop in vitro dialysis with either cuprophane or polysulfone membranes, with or without acetate buffer. After 120 min of recirculation, an increase in cell-associated IL-1-beta was detected, but no changes were seen in the circulating medium. IL-1-beta production was not significantly influenced by either membrane or the dialysate composition. Hemodialysis has been associated with high plasma- and cell-associated IL-1 levels. The kinetics of intradialytic changes of IL-1-beta levels make IL-1 an unlikely cause of acute complications in hemodialysis. On the other hand, a chronic elevation of IL-1 in plasma of patients on maintenance hemodialysis may contribute to the development of some of the long-term complications of this treatment.

Biocompatible Materials↗
PubMed1991

Hemodialysis-associated cardiac arrhythmias: a lower risk with bicarbonate?

The role of hemodialysis (HD) as an arrhythmogenic event has recently been emphasized. We studied 18 patients by Holter monitoring, comparing the arrhythmogenic effect of acetate dialysis (AHD) and bicarbonate dialysis (BHD). The frequency of ventricular arrhythmias was 93 +/- 66/h in AHD and 32 +/- 26/h in BHD (p less than 0.005). According to the classification of Lown and Graboys, classes III and IV were more often to be found in AHD than in BHD and no patient on BHD was in class IVB and class V. Five patients affected with ischemic heart disease had more frequent and dangerous ventricular arrhythmias than the others; a significant difference between buffers was recorded in all cases but 1. Intradialytic changes in body weight, hematocrit, osmolarity, ionized calcium and potassium during AHD and BHD were similar. The two methods only differed in the quickness and degree of correction of acidosis, and this was related to a significant difference in intraerythrocytic potassium at the end of the session. The quicker and more regular correction of acidosis with BHD and the consequent difference in ionic flows between the intra- and extracellular spaces, as demonstrated by changes in intraerythrocytic potassium at the end of the session, could account for the seemingly less arrhythmogenic effect of BHD.

Acetates↗
PubMed1991

Immune deficiency in uremia: interleukin-2 production and responsiveness and interleukin-2 receptor expression and release.

We have studied the role of interleukin-2 (IL-2) and its receptors in the impaired in vitro lymphocyte response characteristic of hemodialysis patients treated by means of cuprophane membranes. The proliferative response of T lymphocytes as well as T-cell-dependent B cell proliferation after stimulation with mitogens was significantly reduced in hemodialysis patients. The in vitro production of IL-2 after such stimulation in parallel cultures was found to be similar in patients and in controls. The expression of IL-2 receptor on the lymphocyte cellular membrane in the hemodialysis group was also similar to controls. The in vitro proliferative response of uremic lymphocytes to exogenous IL-2, however, was significantly depressed suggesting a reduced availability of biologically active IL-2 receptor. The release of soluble IL-2 receptor by lectin-stimulated lymphocytes in culture was also significantly lower in the patient group; yet, hemodialysis patients has a strikingly elevated level of plasma soluble IL-2 receptor, and similar high levels were also found in three other groups of end-stage renal disease patients dialyzed by means of cellulose acetate, polysulfone and polyacrylonitrile membranes, as well as in a group of uremic patients on conservative treatment. In the hemodialysis patient group a significant positive correlation between levels of soluble IL-2 receptor and the duration of hemodialysis was found. Since soluble IL-2 receptor has been reported to down-regulate lymphocyte responses, the elevation in plasma levels of soluble IL-2 receptor in hemodialysis patients may be a pathogenetic factor in the progressive development of impaired immunity associated with end-stage renal disease.

Aged↗
PubMed1991

Prevention of cisplatin-induced emesis: a double-blind multicenter randomized crossover study comparing ondansetron and ondansetron plus dexamethasone.

Ondansetron (OND) is a new 5-HT3 receptor antagonist that give complete protection from emesis/nausea in approximately 50% of cisplatin (CDDP)-treated patients. To evaluate if dexamethasone (DEX) added to OND increases antiemetic efficacy, we carried out a double-blind randomized crossover study to compare the antiemetic activity of OND with OND plus DEX. One hundred two chemotherapy-naive patients (44 women and 58 men) scheduled to receive CDDP chemotherapy at doses greater than or equal to 50 mg/m2 entered the study. Eighty-nine patients completed both cycles with the following results: complete protection from emesis/nausea was obtained in 57/59 patients (64.0%/66.3%) with OND and in 81/79 (91.0%/88.8%) with OND plus DEX (P = .0005/P = .0021). At the end of the study, 53% of the patients expressed a treatment preference, and of these, 74% chose OND plus DEX compared with 26% who preferred OND alone, a statistically significant difference (P less than .003). Side effects were very mild and not significantly different between the two treatments. We conclude that OND plus DEX is more efficacious than OND in protecting patients from CDDP-induced emesis and nausea.

Antiemetics↗
PubMed1991

[Osteoid osteoma of the spine. The experience of the Rizzoli Institute].

The authors report their experience at the Rizzoli Institute in treating osteoid osteomas localized to the spine (40 cases). This clinical study confirms that osteoid osteomas are tumors of adolescence, which are often diagnosed late due to their spinal localization. The role of additional investigations, dominated by bone scan and computed tomography is discussed. Their use should decrease the diagnosis delay. Mean follow-up in this series was 4 years, and confirmed that surgical excision had a favorable outcome. The outcome of associated scoliosis was also studied (8 cases). After tumor excision, there were 6 complete or partial corrections. Two cases remained unchanged. Curvature worsening after excision was not encountered.

Adolescent↗
PubMed1991

The management of malignant bone tumors in children and adolescents.

A series of 205 pediatric patients affected by osteosarcoma, Ewing's sarcoma, fibrosarcoma, and malignant fibrous histiocytoma of bone were treated from 1978 to 1988. Ninety-eight percent of the patients received chemotherapy and 63% had a surgical resection. Sixty-five percent of all patients were alive at 30 months and were considered disease free. The functional results after surgery were evaluated according to the Musculoskeletal Tumor Society score. In all diaphyseal resections and resections of the upper extremity and pelvis, the results were excellent or good in 60% of the cases. In resections of the proximal femur, distal femur, or proximal tibia and reconstruction with nonexpansible prostheses, the results were excellent or good in 75%. On the other hand, when arthrodeses of the lower extremity were used, only 14% of cases had a good result. This correlates with the resulting lack of articulation and serious limb shortening seen with progression of skeletal growth.

Adolescent↗
PubMed1990

Induction of gene expression by IL-1 in NIH 3T3 cells. Possible requirement of protein kinase C activity and independence from arachidonic acid metabolism.

NIH 3T3 fibroblasts were transfected with the chloramphenicol-acetyltransferase (CAT) gene under the control of the SV40 early promoter, which can be stimulated by IL-1. CAT activity in cell lysates and PGE2 release in the supernatants were measured in control and stimulated cell cultures in parallel. Human IL-1 beta (180 pM) and human rTNF-alpha (3 nM) significantly stimulated both CAT activity and PGE2 release. The combined incubation of the two cytokines resulted in a synergistic effect on PGE2 release. The addition of AA (30 microM) greatly stimulated PGE2 release without affecting CAT activity. Similarly, drugs interfering with AA metabolism were without effect on CAT activity although profoundly reducing PGE2 release. Forskolin (0.1 microM) did not modify either parameter. The glucocorticoid fluocinolone (20 nM) was able to decrease both parameters. Protein kinase inhibitors H7 (5-50 microM) and sphingosine (50 microM) inhibited only IL-1-induced CAT activity, whereas H8 (5-50 microM) and HA1004 (50 microM) were ineffective on both parameters. PMA (0.5 microM) and R59 022, a diacylglycerol kinase inhibitor (10 microM), did not modify either control or IL-1-induced CAT activity. IL-1-stimulated PGE2 release was potentiated by PMA, although this effect was not inhibited by H7. The data suggest that: 1) in NIH 3T3 cells the activation of AA metabolism by IL-1 is not involved in IL-1-induced gene expression; 2) protein kinase C activity is required but not sufficient for IL-1-induced gene expression; and 3) PMA may stimulate AA metabolism by a mechanism in part independent of protein kinase activity.

Animals↗
PubMed1990

Lymphocyte activating factor activity in the serum and cerebrospinal fluid of patients with multiple sclerosis.

Serum and cerebrospinal fluid (CSF) from patients with multiple sclerosis (MS), patients with other (non-inflammatory) neurological diseases (OND), patients with non-inflammatory non-neurological diseases, and normal controls were assayed for lymphocyte activating factor (LAF) activity by thymocyte costimulation. LAF activity was detected in normal control sera, which did not differ significantly in this respect from MS or OND patient sera. Not were there significant differences by stage of MS (chronic progressive MS, MS in relapse and MS in remission) or between MS patients and the non-inflammatory non-neurological controls. Almost all the CFSs assayed presented lower values than did the corresponding sera. Serum and CSF after fractionation showed no significant increase in LAF activity except in the 2 MS patients in remission. From these data it may be assumed that LAF activity does not necessarily correspond to the clinical phase of MS. The possible role of LAF activity as a marker of MS progression has yet to be determined.

Adult↗
PubMed1990

Ondansetron (GR38032) in the prophylaxis of acute and delayed cisplatin-induced emesis.

Sixty five chemotherapy naive patients receiving cisplatin (50-120 mg/m2) containing chemotherapy participated in an evaluation of ondansetron, a 5-HT3 receptor antagonist, in the prophylaxis of acute and delayed nausea and emesis. Ondansetron was given as three 0.15 mg/kg doses intravenously (0.5 h before, 3.5 h and 7.5 h after cisplatin) for acute emesis followed by 8 mg orally 8-hourly for five days at 24 h post-cisplatin for delayed emesis. For acute emesis (first 24 h, n = 63), complete control was achieved in 34 patients (54%) and major control (1-2 episodes) in 16 patients (25%). Complete protection from acute nausea was achieved in 48 patients (76%). For delayed emesis (days 2-6, n = 55), 33 patients (60%) were completely protected or reported one to two episodes during the entire 5-day observation period; 63% reported only mild or no nausea. Ondansetron was well tolerated with no significant drug-related adverse events. These results are consistent with serotonin being a significant transmitter of cisplatin-induced emesis.

Acute Disease↗
PubMed1990

Normal T lymphocyte function in patients with end-stage renal disease hemodialyzed with 'high-flux' polysulfone membranes.

T lymphocyte function was analyzed in patients hemodialyzed with 'high-flux' polysulfone membranes, which have been reported to improve the patients' overall clinical condition and well-being. For comparison purposes, patients treated by the use of 'low-flux' cuprophane membranes were also studied. Peripheral blood white cell counts, numbers of lymphocytes as well as the numbers of T cells and their CD4 and CD8 subsets were within normal range in both patient groups. The absolute number of B cells was slightly decreased in cuprophane-membrane- but not polysulfone-membrane-treated patients. The proliferative response of T lymphocytes after stimulation with optimal concentration of phytohemagglutinin (PHA) was normal in patients treated with 'high-flux' membrane dialysis but significantly reduced in those treated with cuprophane membranes. The generation of interleukin-2 (IL-2) receptor on T lymphocytes after PHA stimulation was normal in the polysulfone-membrane-treated group and slightly impaired in the cuprophane-membrane-dialyzed patients. Production of both IL-2 and interleukin-1, as well as the natural killer cell activity, in patients treated by 'high-flux' membrane dialysis were also comparable to controls. The levels of serum beta 2-microglobulin were significantly elevated in patients-maintained on 'high-flux' dialysis membranes but did not reach the levels seen in patients dialyzed by cuprophane membranes. The beta 2-microglobulin at levels seen in patients on cuprophane dialysis had no effects on activation and proliferation of control lymphocytes in vitro. These results suggest that impaired functional responses of T lymphocytes seen in end-stage disease patients on prolonged hemodialysis with cuprophane membranes are not seen in similar patients hemodialyzed with polysulfone membranes.

Biocompatible Materials↗