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Biomedical subjects

D Louis

Publications and source records attributed to D Louis.

At least 37 records · Page 2Linked to original sources
PubMed1994

Desmoplastic small round cell tumors of the abdomen.

BACKGROUND: Desmoplastic small round cell tumors (DSRCT) have been only recently identified. METHODS: The authors report DSRCT in two pediatric patients (an 8-year-old boy and 12-year-old boy). In both patients, the initial diagnosis was rhabdomyosarcoma. The resistance to standard chemotherapy and radiation therapy prompted the authors to review the initial biopsy specimens and perform complementary immunophenotypic characterization. RESULTS: These analyses revealed that the tumor cells were strongly positive for keratin epithelial marker antigen, desmin, vimentin, neurospecific enolase, and S100 protein, corresponding to pleomorphic differentiation, characteristic of DSRCT: CONCLUSIONS: The authors suggest that extensive immunohistologic characterization be performed in all cases of small round cell tumors of the abdomen so that the diagnosis of DSRCT is not overlooked. These rare tumors are refractory to chemotherapy, and initial aggressive surgery is warranted.

Antigens, Neoplasm↗
PubMed1993

[Role of surgery in pediatric oncology].

In paediatric oncology, the surgeon working in a multidisciplinary team can be called upon to intervene at all stages of the disease. At the time of diagnosis, he performs the biopsy, with or without excision of the tumour. He can also intervene for removal of a residual lesion or to evaluate the response after initial chemotherapy. He occasionally is required for metastatic surgery, or more rarely, for palliative surgery.

Age Factors↗
PubMed1993

[Desmoplastic tumors with multiple differentiation. A new entity. Six cases].

Desmoplastic tumours with divergent differentiation are principally located in the abdomen and develop locally or regionally. They occur in adolescents or young adults and are characterized at histology by a proliferation of undifferentiated small cells surrounded by a dense stroma. Only immuno-histo-chemistry provides the diagnosis. Since their chemosensitivity is rare and often partial the outcome is usually lethal. Six new cases of this recently described entity are presented here. The authors are in favour of a multidisciplinary and aggressive management, combining intensive polychemotherapy, extensive surgical exerisis and total abdominal radiotherapy.

Abdominal Neoplasms↗
PubMed1993

Neuropeptide Y inhibits human and invertebrate immunocyte chemotaxis, chemokinesis, and spontaneous activation.

1. In a concentration-dependent manner neuropeptide Y was found to be a potent inhibitor of the spontaneous activation of human granulocytes and macrophages as well as Mytilus edulis immunocytes. 2. Neuropeptide Y also inhibited the chemotaxic response of these immunocytes to the chemoattractant f-MLP. 3. Incubation of both the human and the invertebrate immunocytes in f-MLP (10(-9) M) causes "activation" as noted by random locomotion (chemokinesis). Neuropeptide Y also blocked f-MLP-induced chemokinesis. 4. The results suggest that neuropeptide Y may, in addition to other functions, serve as an endogenous regulator of immunocyte function.

Animals↗
PubMed1993

Double megatherapy and autologous bone marrow transplantation for advanced neuroblastoma: the LMCE2 study.

In the LMCE1 study using a single course of megatherapy most of the relapses occurred during the first 2 years after autologous bone marrow transplantation. A second pilot study (LMCE2) was therefore set up using a double harvest/double graft approach with two different megatherapy regimens. Objectives were to test the role of increased dose intensity on response status, relapse pattern and overall survival. Thirty-three patients (20 boys, 13 girls) with a median age of 53 months at first megatherapy (range, 17-202 months) entered this study. They were cases either with refractory disease in partial response after second line treatment for stage 4 neuroblastoma (n = 25) or after relapse from stage 4 (n = 5) or stage 3 disease (n = 3). All patients received Etoposid and/or Cisplatinum (or Carboplatin) containing treatments before megatherapy. The first megatherapy regimen was a combination of Tenoposid, Carmustine and Cisplatinum (or Carboplatin), the second applied Vincristin, Melphalan and Total Body Irradiation. The first harvest was scheduled 4 weeks after the last chemotherapy, the second 60 to 90 days after megatherapy. All marrows were purged in vitro by an immunomagnetic technique. Median follow up time since first megatherapy is 56 months. Response rates for evaluable patients were 65% (complete response rate: 16%) for megatherapy 1 and 60% (complete response rate: 25%) for megatherapy 2. Considering that only patients with delayed response or relapse were eligible for this pilot study the overall survival was encouraging with 36% at 2 years and still 32% at 5 years. The costs for these survival rates were high in terms of morbidity (four early and four late toxic deaths; toxic death rate: 24%). Double harvesting may have the disadvantage of delayed engraftments related in part to a disturbance of marrow microenvironment by megatherapy 1. This double megatherapy approach achieved a prolonged relapse free interval (median 11 months, range 2-31 months) in patients reaching megatherapy 2 and justifies further evaluation of concepts with consecutive dose-escalation.

Adolescent↗
PubMed1993

Cystic fibrosis and portal hypertension interest of partial splenectomy.

Extra pulmonary complications can be major in patients suffering of cystic fibrosis who survive long enough without pulmonary problems. Hepatic cirrhosis is often present and is responsible for portal hypertension with splenomegaly, hypersplenism and esophageal varices. In six patients we have performed a partial splenectomy with conservation of the upper pole of the spleen vascularized by gastrosplenic omentum and its vessels. The post-operative complications (3 scar ruptures but no pulmonary decompensation) are not very important considering the benefits: Normal spleen according to clinical, ultrasonic examination and scintigraphy Correction of hypersplenism Diminution of esophageal varices Stability of hepatic functions. With a post-operative follow-up between 2.5 and 7 years, none of the patients had an increased risk of infection. This technique allows a good survival for those patients waiting for pulmonary transplantation.

Adolescent↗
PubMed1993

[Congenital hypoplasia of the left pulmonary artery and exertion hypoxemia].

The reported case concerns a 12-year-old boy with a congenital hypoplasia of the left pulmonary artery without associated cardiac malformation. At rest, pulmonary function tests were within the normal range, while the patient demonstrated an abnormal dyspnea and hypoxemia during exercise. These symptoms disappeared after left pneumonectomy. Unilateral pulmonary artery hypoplasia can be responsible for exercise hypoxemia due to an intermittent right-to-left shunt or a ventilation-to-perfusion mismatching.

Child↗
PubMed1992

Ultrasound diagnosis of midgut volvulus: the "whirlpool" sign.

The authors present their US findings in 24 patients with proved complicated midgut malrotation: volvulus in 18 and occlusive Ladd's bands in 6. All the 24 patients have had US examination prior to surgery. Contrast examinations were performed in only 9 patients, always after US and before surgery. The sonographic "whirlpool" pattern of the superior mesenteric vein and mesentery around the superior mesenteric artery was detected in 15 of the 18 patients with midgut volvulus, and was best seen using Doppler color. Embryological signification of midgut malrotation is discussed.

Duodenal Diseases↗
PubMed1992

Heart-lung transplantation in a 16-month-old infant.

A 16-month-old boy who had a heart-lung transplantation is doing well 16 months postoperatively. The HLT can be a successful treatment for very young patients. Most of the postoperative management can be assessed with noninvasive techniques. Normally, the allograph grows with the recipient.

Heart-Lung Transplantation↗
PubMed1991

TP53 gene mutations and 17p deletions in human astrocytomas.

Astrocytomas, including the most malignant form, glioblastoma multiforme, are the most frequent and deadly primary tumors of the human nervous system. Recent molecular genetic analyses of astrocytomas have demonstrated frequent chromosome 17 deletions involving the telomeric region of the short arm (17p12-pter). This region contains a candidate tumor suppressor gene, TP53, which has recently been implicated in the etiology of a broad array of human cancers. To study the possible role of TP53 in astrocytoma development, 24 randomly chosen human astrocytic tumors were examined for genomic TP53 sequence aberrations using primer-directed DNA amplification in conjunction with direct sequencing. Five of the 11 grade III astrocytomas (glioblastoma multiforme), but only one of seven grade II astrocytomas (anaplastic astrocytoma) and none of either the grade I astrocytomas or oligodendrogliomas demonstrated distinct point mutations involving the TP53 gene. These data suggest that TP53 mutations may play a role in astrocytoma development and are predominantly associated with higher grade tumors.

Adult↗
PubMed1991

Relationship between the cardiovascular effects and both plasma and myocardial levels of clentiazem, a new benzothiazepine calcium antagonist, in anesthetized dogs.

We evaluated the relationship between the cardiovascular effects of clentiazem (TA-3090), a new 1,5-benzothiazepine calcium antagonist with high lipophilicity, and both its plasma and myocardial concentrations. Anesthetized, open-chest dogs, instrumented for hemodynamic data recording and blood sampling, were divided into three groups treated with 15, 50, or 200 micrograms/kg of clentiazem, respectively, as an intravenous bolus. At the end of the protocol (240 minutes), myocardial samples were tested for clentiazem. The results indicated that the peripheral and coronary vasodilatory effects of clentiazem were dose dependent and closely related to its plasma concentrations. It was also observed that the minimal effective plasma concentration was in the range of 15-20 ng/ml. Sustained negative chronotropic effects were recorded at the highest dose only and were best related to the amount of clentiazem detectable in the myocardium, suggesting that myocardial clentiazem retention is a major factor governing its depressant cardiac impact.

Animals↗
PubMed1991

Management of pediatric non-Hodgkin's lymphoma.

Over the past 15 years, significant progress has been made in the understanding of the molecular mechanism involved in malignant transformation of lymphocytes as well as in the management and treatment of non-Hodgkin's lymphoma (NHL) in childhood. Cyto-histological classifications and immunophenotyping of different types of NHL have contributed to the characterisation of three major subtypes of NHL in children i.e. Burkitt's lymphoma (BL), lymphoblastic lymphoma (LL) and large cell lymphoma (LCL). Precise staging of the disease at diagnosis is necessary before the onset of the treatment and should be performed as quickly as possible. Presence of bone marrow and central nervous system (CNS) involvement are major prognosis criteria. In most cases, surgery has no therapeutic role and is required only for diagnostic procedures. Similarly, several studies have demonstrated that irradiation of various sites including the CNS does not improve survival. Thus, NHL patients are usually treated with chemotherapy alone. BL and LL have distinct clinical presentations and require completely different chemotherapy protocols. After comparable induction phases with intensive chemotherapy regimens, the former is usually treated with a short consolidation phase while the latter receives a long lasting consolidation consisting of intermittent chemotherapy for at least one year. The prognosis of stage I-II, and III-IV bone marrow negative NHL of children is excellent with respectively 95% and 75% long term survival. However, patients with concomittent CNS and bone marrow involvement in both histological subtypes have a considerably worse prognosis with only 30% long term survival.(ABSTRACT TRUNCATED AT 250 WORDS)

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1990

[Acute intestinal intussusception: ultrasonic diagnosis and air insufflation].

Sixty-five children with intussusception were diagnosed by ultrasonography. Colonic air insufflation was the principle form of treatment. The diagnosis value of ultrasound was 100% and the success rate of reduction by air insufflation was 93%, after intrarectal injection of midazolam (0.3 mg/kg). The device for insufflation was simple, original and manual, with permanent control of intrarectal pressure. No complications were observed.

Acute Disease↗
PubMed1989

Preservation of infralevator structures in imperforate anus repair.

In this report, we describe the most recent refinements to the anterior perineal approach originally described by Mollard for the repair of high and intermediate forms of imperforate anus. A skin tube is constructed from perineal skin, passed through the center of the external sphincter, and anastomosed to the fully preserved rectum with or without tapering. The anastomosis lies within the puborectalis sling and is anchored to the striated muscle complex. Sixteen patients have been operated on by this technique with excellent anatomic results in 15 patients and excellent early functional results in patients who are 2 years of age or older.

Anal Canal↗
PubMed1989

[The Jaubert de Beaujeu technic in the treatment of hiatal hernia in newborn infants and children. Results apropos of 810 patients surgically treated from 1960 to 1986].

810 patients have been operated from 1960 to 1986 for gastroesophageal reflux. The surgical management has always been the same by an abdominal approach: dissection and repositioning of lower esophagus, closure of the columns, fixation of the esophagus to the columns, fixation of the gastric tuberosity to the esophagus and making an anterior valve. 59% of the patients have less than one year and 14.5% have been operated for respiratory syndromes. Mortality was 1.2% and 7% of patients developed post-operative complications. Because geographic diversity of the patients only one year results have been studied. 56 patients have been lost for follow up. 90.4% of patients have a clinical and radiological good result.

Child↗