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Biomedical subjects

P Valle

Publications and source records attributed to P Valle.

18 recordsLinked to original sources
PubMed1999

[Meckel's diverticulum: ten years experience].

Meckel's diverticulum (MD) is the most common congenital anomaly of the gastrointestinal tract. The majority of MD cases are asymptomatic although they can, occasionally, cause complications such as bleeding, intestinal obstruction and/or inflammatory process. The diagnosis is difficult and it is usually made at surgery. The treatment of choice in the patients with symptomatic MD is surgical resection while difference of opinion there are about the treatment of asymptomatic MD. The present study concerns 9 cases of MD, 7 symptomatic and 2 incidentally found during surgical abdominal operations. Six patients was males and 3 females with 2:1 male: female ratio. The mean age was 14.7 years. The most common complication was the diverticulitis with the perforation of MD in 1 patient. All patients, symptomatic and asymptomatic, was operated. The diverticulectomy was made in 7 patients while in 2 cases we had to perform an intestinal resection. There was not operative mortality, while there were 2 cases of postoperative complications which occurred only in the patients with symptomatic MD. The Authors believe that there is no factor predictive of the development of diverticular complications. They recommend, in light of the low postoperative mortality and morbidity, the surgical treatment also in the cases of asymptomatic MD, in the absence of absolute contraindications.

Adolescent↗
PubMed1997

Stem cell factor suppresses apoptosis in neuroblastoma cell lines.

Stem cell factor (SCF) is a glycoprotein growth factor produced by marrow stromal cells that acts after binding to its specific surface receptor, which is the protein encoded by the protooncogene c-kit. SCF synergizes with specific lineage factors in promoting the proliferation of primitive hematopoietic progenitors, and has been administered to expand the pool of these progenitors in cancer patients treated with high-dose chemotherapy. SCF and its c-kit receptor are expressed by some tumor cells, including myeloid leukemia, breast carcinoma, small cell lung carcinoma, melanoma, gynecological tumors, and testicular germ cell tumors. Previous studies of SCF in neuroblastoma have produced conflicting conclusions. To explore the role of SCF in neuroblastoma, we studied five neuroblastoma lines (IMR-5, SK-N-SH, SK-N-BE, AF8, and SJ-N-KP) and the neuroepithelioma line CHP-100. All lines expressed mRNA for c-kit and c-kit protein at low intensity as measured by flow cytometry, and secreted SCF in medium culture as shown by ELISA. Exogenous SCF did not modify 3H thymidine uptake in the neuroblastoma and neuroepithelioma cell lines. After 6 days' culture in the presence of anti-c-kit, the number of viable neuroblastoma cells was significantly lower than the control, and terminal deoxynucleotidyl transferase assay showed a substantial increase of apoptotic cells: The percentage of positive cells was 1-3% in the control lines, whereas in the presence of anti c-kit it varied from 29% of SK-N-BE to 92% of CHP-100. After 9 days' culture in the presence of anti-c-kit, no viable cells were detectable. These data indicate that SCF is produced by some neuroblastoma cell lines via an autocrine loop to protect them from apoptosis.

Antibodies, Monoclonal↗
PubMed1996

Brain-derived neurotrophic factor protects neuroblastoma cells from vinblastine toxicity.

Brain-derived neurotrophic factor (BDNF) and its receptors are necessary for the survival and development of many neuronal cells. Because BDNF and TrkB are expressed in many poor-prognosis neuroblastoma (NB) tumors, we evaluated the role of BDNF in affecting sensitivity to chemotherapeutic agents. We investigated the effects of activation of the BDNF-TrkB signal transduction pathway in two NB cell lines, 15N and SY5Y. 15N cells lack the high-affinity receptor p145TrkB and express BDNF; 15N cells were used along with 15N-TrkB cells, a subline transfected with a TrkB expression vector. In cytotoxicity assays, 15N-TrkB cells were consistently 1.4-2 fold more resistant to vinblastine than 15N cells. Drug accumulation assays showed a 50% reduction in[3H]vinblastine accumulation in 15N-TrkB cells compared with control 15N cells. Addition of 30 ng/ml BDNF resulted in a reduction to 46% of control in 15N cells and a reduction to 28% of control in 15N-TrkB cells. SY5Y cells were chosen as a second model because they lack both endogenous BDNF and TrkB expression. p145TrkB expression is induced by 1 nM retinoic acid. Vinblastine accumulation was not significantly affected by 1 nM retinoic acid in SY5Y cells. Addition of 30 ng/ml BDNF decreased [3H]vinblastine accumulation to 58% of control in SY5Y cells and decreased [3H]vinblastine accumulation to 62% of control in TrkB-expressing SY5Y cells. Although an increase in BDNF expression in seen in multidrug-resistant sublines of SY5Y and BE(2)-C NB cells, the protective effect of BDNF in vinblastine toxicity may be unrelated to mdr-1, because the activity of other agents transported by P-glycoprotein was not affected. There was no increase in mdr-1 expression in 1 nM RA SY5Y cells and 15N-TrkB cells, as assessed by Northern blot analysis. In addition to the effects of BDNF on vinblastine cytotoxicity and accumulation, there was an inhibition in the ability of vinblastine to depolymerize tubulin in BDNF-treated cells. Thus, BDNF and TrkB may partially rescue NB cells from vinblastine toxicity and thereby may contribute to a more chemoresistant phenotype.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1995

Subcutaneous juvenile xanthogranuloma.

A 1-month-old female infant was seen in consultation because of a congenital subcutaneous nodule, 2 x 3 cm in diameter, in the right retroauricular area. The nodule was surgically excised. Histologically, a large subcutaneous nodular mass was well delimited but not encapsulated. It consisted of a monomorphous sheet of foamy histiocytic cells with scattered eosinophils. Multinucleated giant cells were not found. The pure subcutaneous type of juvenile xanthogranuloma has been reported very rarely in the literature. The usual histological monomorphism of these cases, with only occasional eosinophils and lymphocytes and rare Touton giant cells, adds another diagnostic difficulty to their unusual clinical presentation.

Female↗
PubMed1994

Efficacy of tropisetron (Navoban) in controlling emesis induced in children by anti-cancer therapy.

AIMS AND BACKGROUND: High doses of metoclopramide are contraindicated to prevent chemotherapy-induced emesis in pediatric patients, since the incidence of extrapyramidal reactions is increased in these patients. The aim of this small study was to evaluate the antiemetic activity and the safety of tropisetron (a new selective antagonist of 5-HT3 receptors) in children who suffered nausea and vomiting during previous chemotherapy courses, despite the administration of an anxiolytic agent (hydroxyzine hydrochloride). METHODS: The children with a malignant neoplasm were treated for emesis with tropisetron (5 mg o.a.d. or b.i.d.) during a total of 20 cycles of chemotherapy with carboplatin combined with other antitumor agents. RESULTS: In 14 cycles (70%), there was no vomiting. There were two or less episodes of vomiting in 2 cycles (10%), 3-4 episodes in 2 cycles (10%), and no inhibition of vomiting at all in 2 cycles (10%). In 8 cycles there were no episodes of nausea (40%), in 5 cycles (25%) there were episodes of moderate nausea, and in 4 (20%) there were episodes of severe nausea. One child had a mild headache during one cycle and moderate hypotension during another. CONCLUSIONS: The results suggest that tropisetron is both efficacious and safe for the treatment of pediatric patients.

Adolescent↗
PubMed1994

Effect of desferrioxamine and hydroxypyridones on hemopoietic progenitors and neuroectodermal tumor cells.

The iron chelator desferrioxamine (DFO) has been shown to inhibit the proliferation of hemopoietic progenitors and several tumor cell lines. We have compared the in viro hemopoietic inhibitory effect of desferrioxamine (DFO) and hydroxypyridones (HPOs) on hemopoietic progenitors and two human neuroectodermal (NE) tumor cell lines, NB 100 and SKNMC. Both DFO and HPOs showed a direct dose-related inhibitory effect on BFU-E and CFU-GM obtained from purified human non-T MNAC (T-lymphocyte-depleted nonadherent mononuclear cells) and CD34+ cells. DFO and HPOs displayed both an inhibitory and a cytotoxic effect on NE cell lines. We calculated the ratio between NE cell and hemopoietic cell growth inhibition for a range of concentrations of chelators. DFO showed the most satisfactory ratio. This suggests that DFO is still the most preferable chelating agent for the treatment of neuroblastoma, since it combines the highest antineuroblastoma effect with the lowest hematopoietic toxicity.

Antithyroid Agents↗
PubMed1982

Effect of light deprivation on sleep in the rat.

The sleep-wake cycles of 24- and 30-day-old rats reared in darkness from 48 hr after bith (E) were polygraphically recorded in 3 3-hour sessions (0900-1200 hr; 1230-1530 hr; 1600-1900 hr) and compared to normally reared controls (C). The total amount of paradoxical sleep (PS) over the 3 3-hr sessions of the light-deprived rats (E24 and E30) was significantly less than in the controls (C24, and C30). The distribution of PS over the 3 sessions was different for the control groups: C24 showed a significantly greater amount of PS and SWS during 1230-1530 hr, and C30 during 1230-1530 and 16-19 hr. Light-deprived groups showed no significant variations neither in PS nor in SWS or W within the three sessions. These data fail to support the hypothesis that PS functions as a compensatory stimulation under conditions of low stimulation.

Age Factors↗
PubMed1981

[Our experience with emergency surgical treatment of acute cholecystitis].

A clinical series of 580 patents (318, F, 199 M) personally observed at the Emergency Surgery and First Aid Division of the Fatebenefratelli and Ophthalmic Hospital Board of Milan between 1975 and 1980, and suffering from acute inflammation of the bile ways (gall bladder empyemas, acute cholecystitis, gangrene of the gall bladder, haemobilia due to gall bladder puncture), has been examined. Of these patients, 558 were subjected to surgery between 12 hours and 6 days after admittance. Operated patients are subdivided into 4 groups on the basis of their anatomo-pathological form and the average time interval between admittance and intervention. Critical examination shows that their behaviour with respect to acute inflammatory forms of the gall bladder can be split up as follows: 1) immediate surgery (within 12 hours) for empyematous and/or punctured forms; 2) emergency surgery (within 2 days of admittance) for cases with certain diagnosis backed up by historical and X-ray data pointing to calculosis of the gall bladder; 3) early surgery (within 3 days) for cases with certain diagnosis but without prior X-ray documentation; 4) deferred surgical intervention (within 6 days) for patients without X-ray documentation and in whom immediate medical treatment leads to a rapid improvement in the clinical picture. The very good clinical results obtained and the observation of a low mortality and morbility index (comparable to those of surgery of choice) suggest that early surgery is certainly the therapy of choice when dealing with acute cholecystitis.

Acute Disease↗
PubMed1977

[Occlusions and perforations caused by carcinoma of the colon and rectum].

A group of 137 patients observed at the Emergency Surgery and First Aid Division of the Fatebenefratelli Hospital of Milan between 1971 and 1974 is examined. The patients all presented a clinical picture of occlusion and/or perforation of the colon and rectum due to carcinoma, requiring emergency surgery. The clinical material examined is analysed and the surgical treatment adopted and the results obtained reported. Post-operative mortality was 16.8% in cases of occlusion, 21.6% in cases of perforation, and 36.4% in mixed cases. 63 patients, i.e. 46%, were subjected to more or less extensive resection and the mortality in this group was 11.2%; in the remaining 74 patients, ax only palliative measures were possible and mortality was 28.3%. It is observed, finally, that among emergency colon operations, right colectomy carried out immediately offers encouraging results, while resection of the left colon, apart from certain special cases, should be preceded by decompressive colostomy.

Adult↗
PubMedDate not supplied

Effect of different exposures to desferrioxamine on neuroblastoma cell lines.

Desferrioxamine (DFO) has shown anti-proliferative and cytotoxic effects on several tumor cells. DFO is used at present in the treatment of neuroblastoma in combination with chemotherapy (D-CECaT regimen: cyclophosphamide, etoposide, carboplatin, and thiotepa). We compared the effect of continuous or intermittent exposures to DFO on 3H-thymidine uptake, viability, and cell cycle of human neuroblastoma (NB) cell lines. Our results show that continuous exposures to DFO cause dose- and time-dependent cytotoxicity of NB cells, while intermittent exposures result in significant NB cell toxicity only when using high DFO concentrations. By 3H-thymidine uptake, a significant inhibition of proliferation was observed only in continuous exposures. In addition, a consistent arrest in G1 phase was detected only in cultures treated continuously with high DFO concentrations. Our data indicate that 3H-thymidine uptake, viability, and cell cycle changes are proportional to the extent of exposure and concentration of DFO, suggesting that in vivo DFO continuous infusion may improve anti-neuroblastoma activity.

Antineoplastic Agents↗
PubMedDate not supplied

[The Cockett syndrome among the syndromes caused by compression of the common iliac vein].

A short account of the aetiopathogenesis of the iliac vein compression syndrome is followed by a description of a little-known form, called Cockett's syndrome, due to compression of the left iliac vein by the right common iliac artery. This syndrome should be looked for with care. If diagnosed in the "functional" stage, it can be ameliorated by means of a special surgical treatment known as "venous stocking plasty".

Femoral Vein↗