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Biomedical subjects

P Tron

Publications and source records attributed to P Tron.

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

Metastatic medulloblastoma: the experience of the French Cooperative M7 Group.

A retrospective analysis was performed to determine the outcome of children with metastatic medulloblastoma given a standardised treatment programme. Of 68 consecutive patients treated in the French M7 protocol for medulloblastoma, 23 presented with metastatic disease. They were uniformly treated with surgery, and the same protocol of chemotherapy and craniospinal radiotherapy. The 7-year relapse-free survival rate is 43% for metastatic patients compared to 68% for patients with localised disease. Survival did not correlate with age, sex, location of metastases, extent of initial surgery and the dose of radiation therapy on the posterior fossa. Survival did correlate with the dose to the cranial field with a threshold dose of 30 Gy. Patients with metastatic disease have a worse prognosis and require more aggressive therapies at initial presentation. The prognostic impact of the different sites of metastatic disease requires further evaluation in cooperative studies.

Adolescent↗
PubMed1994

[Langerhans-cell histiocytosis in twin sisters].

BACKGROUND--Histiocytosis of Langerhans cells includes a range of clinical manifestations that have been described as bone eosinophilic granuloma, Hand-Schüller-Christian syndrome, Letterer-Siwe syndrome and Hashimoto-Pritzker histiocytosis. These syndromes represent a spectrum of severity and prognosis of the same underlying disorder which is usually sporadic. It has occurred in monozygotic twins and in a familial pattern. This report describes monozygotic twins who developed the disease a few months after their father was found to be suffering from Hodgkin's disease. Case n. 1.--A 4 month-old girl was admitted because of fever, disseminated lymphadenopathy and hepatomegaly. She also had interstitial pneumonia. Infiltrating abnormal histiocytes were demonstrated in lymph node and bone marrow biopsies. X-rays showed lytic areas in the skull. Serology for EBV infection was negative. Special studies with immune markers of lymph node histiocytes confirmed the diagnosis of Langerhans cell histiocytosis, and more precisely, Letterer-Siwe syndrome. The patient was given prednisolone followed by vinblastine without success. She was given etoposide 11 weeks later, which induced remission. This treatment was replaced by vinblastine when the patient was aged 2 years 9 months. Case n. 2.--The monozygotic twin of the case n. 1 was also admitted at 4 months of age because of the same manifestations. Laboratory findings were identical to those of her sister, as was her response to the same drugs. The father was diagnosed as having Hodgkin's disease 3 months before the first manifestation of Langerhans cell histiocytosis in his daughters. His maternal uncle had also been treated for Hodgkin's disease. Immunologic studies of the twin were negative. CONCLUSION--These cases of Langerhans cell histiocytosis in monozygotic twins have no apparent relationship with the Hodgkin's disease of their father. Etoposide seems to be useful for treating such severe forms of the disease.

Diseases in Twins↗
PubMed1993

Phase II study of ifosfamide in childhood brain tumors: a report by the French Society of Pediatric Oncology (SFOP).

Forty-two evaluable pediatric patients with a variety of recurrent primary brain tumors participated in a phase II ifosfamide trial. Their mean age was 10 years. All patients were treated with ifosfamide, 3 g/m2/day for 2 days every 2 weeks. Response was assessed on clinical and radiological criteria after at least 2 courses of therapy. The overall response rate was 12% (5/42). One complete and 2 partial responses were documented in 21 patients with medulloblastoma. A partial response was demonstrated in 1 patient with primitive neurectodermal tumor (PNET) and in 1 patient with ependymoma. No activity was observed in astrocytic tumors. Toxicity was primarily neurologic (16 out of 54 patients, 30%). Hematological toxicity, without severe morbidity, was encountered in 9% of courses (16/179). Ifosfamide, administered at this dose regimen has modest efficacy in the treatment of recurrent childhood medulloblastoma and ependymoma and appears inactive for gliomas. Further trials with other dose schedules are necessary to assess the activity of this drug. However, according to the neurotoxicity observed in our trial, we would not recommend building a protocol using ifosfamide for highly progressive brain tumors.

Adolescent↗
PubMed1993

Thyroid hormone and dietary carbohydrate induce different hepatic zonation of both "spot 14" and acetyl-coenzyme-A carboxylase: a novel mechanism of coregulation.

The S14 gene encodes a protein found in the nuclei of lipogenic tissues that is induced synergistically by thyroid hormone (T3) and dietary carbohydrate, as are several lipogenic enzymes. In hyperthyroid rats, hepatic expression of S14 protein is zonated. The established association of S14 gene expression with lipogenesis, therefore, prompted a comparison of the zonal distribution of induction of S14 and acetyl-coenzyme-A-carboxylase (ACC), a rate-determining enzyme of fatty acid synthesis, by T3, dietary carbohydrate, and both stimuli together. As determined by immunohistochemistry, liver from chow-fed hypothyroid or euthyroid fasted rats showed essentially no reactivity for either S14 or ACC. Sections from hyperthyroid rats exhibited nuclear staining with anti-S14 antibodies and cytoplasmic reactivity for ACC that was primarily perivenous in both cases. In contrast, sections from euthyroid-fasted animals refed a high carbohydrate, fat-free diet for 3 days exhibited panlobular expression of both antigens. Animals receiving both T3 and high carbohydrate diet refeeding showed increased intensity of staining, compared to the refed group, for both S14 and ACC across the entire lobule. Therefore, in rats consuming normal chow, T3 induced S14 and ACC only in the perivenous zone of the acinus, whereas it further induced these proteins across the entire lobule in the presence of increased carbohydrate intake. Modulation, by the carbohydrate content of the diet, of the fraction of the liver that may express S14 and ACC in response to T3 provides a mechanism for coregulation of the genes involved in hepatic lipid formation. Moreover, the observed cozonation of S14 and ACC as well as the quantitatively similar effects of T3 and dietary carbohydrate on S14, ACC, fatty acid synthetase, and ATP-citrate lyase protein abundance prompt the speculation that S14 acts in the nucleus to promote expression of the genes involved in the lipogenic pathway.

Acetyl-CoA Carboxylase↗
PubMed1993

[Extensive fibrous endocarditis as first manifestation of systemic lupus erythematosus].

BACKGROUND: Cardiac abnormalities, such as myocarditis, pericarditis or verrucous endocarditis (Libman-Sacks endocarditis) occur in about one third of patients with systemic lupus erythematosus. This study describes an unusual aspect of endocardial involvement. CASE REPORTS: Case no. 1: A 14 year-old girl was admitted 3 months after acute hemichorea because of heart failure plus biological inflammatory findings. Echocardiography showed mitral insufficiency with enlargement of the left atrium and ventricle. There was some infiltration involving the endocardium of the left ventricle, the chordae tendinae and the mitral valve. The titres of anti-DNA and anti-nuclear antibodies were elevated while the serum hemolytic complement was depressed. Skin biopsy showed IgG, IgM and C1q deposits along the dermoepidermal junction. Corticosteroids, diuretics and vasodilator drugs failed to completely cure the heart failure; the mitral insufficiency required mitral valve replacement 21 months later. Pathological examination showed extended fibrotic changes of the endocardium. Case no. 2: A 4 year-old boy was admitted for acute heart failure due to mitral insufficiency, associated with biological inflammatory findings. Echocardiography showed mitral insufficiency and enlarged left atrium and ventricle. Anti-DNA and anti-nuclear antibody titres were elevated. The patient was given antibiotics followed by corticosteroids and immunosuppressive drugs. The persistence of the mitral insufficiency required mitral valve replacement 7 months later. Pathological examination showed fibrotic changes of the endocardium. Exacerbation of the inflammatory process was seen 2 months after surgery, with development of diffuse proliferative lupus nephritis. The patient died of kidney failure and neurological complications, 44 months after cardiac surgery. CONCLUSION: In both patients, the systemic lupus erythematosus was revealed by endocardial involvement, a complication that is usually seen later. The endocardium changes responsible for mitral insufficiency and requiring valve replacement in these two cases were different from those described as verrucous endocarditis in classical forms of the disease.

Adolescent↗
PubMed1993

[Clear cell sarcoma of the tendons and aponeuroses].

BACKGROUND: Clear cell sarcoma of tendons and aponeuroses is a rare mesenchymal tumor in childhood. It is difficult to treat and its prognosis is bad. CASE REPORT: A 9 year-old girl was admitted because of persistent pain in the left lower part of her thorax. Clinical examination showed a mass, 4 cm in diameter, embedded in the thoracic wall. Ultrasonography and CT-scan showed that this mass extended between the last ribs to the pleural cul-de-sac. There was no adenopathy and myelogram was normal. Biopsy of the mass showed features of clear cell sarcoma of tendons and aponeuroses. Cytogenetic studies showed translocation t(12;22) (q13-14;q12) in tumor cells. The patient was given chemotherapy followed by complete resection, but the tumor recurred locally 3 months later and the patient died, despite chemotherapy plus radiotherapy, 23 months after the apparent onset of disease. CONCLUSION: Treatment of this type of tumor remains difficult. The existence of a break point on 22q12, as in Ewing sarcoma, suggests that this tumor in of neural crest cell origin.

Child↗
PubMed1993

[Isolated acute peripheral facial paralysis in children. Etiological and prognostic study].

BACKGROUND: As facial nerve palsy is usually of sudden onset and of obscure etiology, a survey of large series may provide new information. PATIENTS AND METHODS: The files of 40 children suffering from acute facial nerve palsy seen in 3 pediatric and 1 otorhinolaryngologic (ORL) departments between 1980 and 1990 were analysed. Patients with congenital palsy and those with paralysis that appeared after injury or in the course of acute or chronic disease (otitis media, tumor) were excluded from the study. The children were 9 months-16 years old (mean: 7 year 1 month). There were 22 left and 18 right facial nerve palsies. The palsy was moderate in 17 children, severe in 15, and total in 5. Etiologic factors (viral serologic studies, CSF examination), ORL studies and electromyogram of the facial nerve were analyzed in the majority of cases. Corticosteroids were used in 30 patients. RESULTS: A viral etiology was suspected and/or confirmed in 13 children; abnormalities were seen in 6 of the patients who underwent lumbar puncture. A familial facial nerve palsy was seen in 1 case and kidney disease in 2 cases. 23 cases appeared to be idiopathic. A moderate permanent residual weakness was seen in only 4 children. The mean time for recovery was 32 days (4-140 days). Corticosteroids did not influence the incidence of complete recovery, but decreased the time for recovery (26 versus 37 days) only in the patients who were treated before the 3rd day of the disease. Patients with idiopathic palsy recovered 23 days before those with viral etiology. CONCLUSIONS: Idiopathic and post-viral facial nerve palsies seem to have an excellent prognosis. Corticosteroids seem to have no effect although there is some evidence of benefit when treatment is begun early.

Acute Disease↗
PubMed1992

Genetics and epidemiology of Wilms' tumor: the French Wilms' tumor study.

A complete family history was obtained for 501 patients with Wilms' tumor, treated in departments of pediatric oncology in whole France. The information was collected by self-questionnaire and/or by interview of parents. The proportion of bilateral cases is 4.6% and there are 12 patients (2.4%) with a positive family history of Wilms' tumor. The affected relatives are most often distant and no first degree relative was affected. Apart from the well-known associations with aniridia, hemihypertrophy, genitourinary anomalies, Beckwith-Wiedeemann, and Drash syndromes, there is also a significant excess of congenital heart defects (P = .008) which remains to be explained. Several findings support the bimutational hypothesis such as earlier diagnosis and increased parental age in bilateral cases. No particular anomalies and no increased frequency of childhood cancer were found in patients' relatives. The frequency of Wilms' tumor in relatives was estimated to be less than 0.4% in sibs, 0.06% in uncles and aunts, and 0.04% in first cousins. These figures are very different from those found in retinoblastoma and suggest that the mechanism may be more complex in Wilms' tumor. This conclusion is in agreement with molecular biology studies in tumors and linkage analysis in multiple case families which suggest that more than one locus is involved.

Adolescent↗
PubMed1992

M4 protocol for cerebellar medulloblastoma: supratentorial radiotherapy may not be avoided.

The main goal of the M4 protocol was to evaluate the efficacy of treatment excluding supratentorial radiation in patients with newly diagnosed medulloblastoma. All patients underwent surgical resection and received postoperative chemotherapy. Chemotherapy was adapted to the initial staging and prognostic factors (Group A: good-risk; Group B: poor-risk). Chemotherapy was started early after surgery, and consisted of two courses of the "eight drug in one day" regimen and two courses of high dose methotrexate. Radiotherapy was delayed until 5 (Group B) to 7 (Group A) weeks after the first course of chemotherapy. Radiotherapy was administered only to the posterior fossa and the spinal axis. Only 3/16 patients (18%) are alive and disease-free with a mean follow up of 6 years. The site of progression was supratentorial in 9 out of 13 patients and three patients had spinal and/or cerebrospinal fluid relapses. Only one patient had isolated posterior fossa relapse. The mean time to relapse was 484 days. We conclude that the chemotherapy regimens used in the M4 protocol do not allow the reduction of irradiation fields in patients with cerebellar medulloblastoma. In spite of long-term side effects on neurocognitive functions, supratentorial radiotherapy should remain a major component of medulloblastoma treatment.

Adolescent↗
PubMed1992

Nuclear localization and hepatic zonation of rat "spot 14" protein: immunohistochemical investigation employing anti-fusion protein antibodies.

S14 protein and mRNA levels are rapidly regulated by hormones and diet. We have purified a 45-Kd fusion protein from lysates of transformed E. coli that includes the entire S14 polypeptide. Affinity-purified rabbit anti-fusion protein antibodies were used in immunohistochemistry to determine the distribution of S14 protein across the hepatic lobule, and to reassess its intracellular location. In hyperthyroid liver, S14 protein clustered near the central venous zone, and was not detectable in the periportal area of the acinus. The signal in perivenous hepatocytes was primarily nuclear in location, in stark contrast to previous subcellular fractionation studies. Visualization of identical hepatic distribution and subcellular localization employing anti-synthetic peptide antiserum provided evidence for the specificity of the immunostaining, as did attenuation of the signal by preincubation of the antibody with its antigen. No staining was observed in sections of heart or hypothyroid liver, as expected from the low levels of S14 protein in those tissues. The data indicate that induction of S14 protein expression by T3 occurs through enhanced expression by perivenous hepatocytes, rather than by recruitment of cells in more peripheral zones of the lobule. Nuclear localization of the S14 protein by immunohistochemistry suggests that it is lost from nuclei during standard fractionation procedures, and prompts consideration of a role for S14 in regulation of nuclear structure and/or function.

Animals↗
PubMed1991

Clear cell sarcoma with t(12;22) (q13-14;q12).

Karyotypic analysis of a clear cell sarcoma revealed a translocation t(12;22) (q13-14;q12) as a primary chromosomal change. This case is the third clear cell sarcoma cytogenetically analyzed; the two previously reported cases had t(12;22)(p11;p11), and a complex karyotype with trisomy 22, respectively.

Chromosome Banding↗
PubMed1991

Pancreatoblastoma: response to chemotherapy.

Two cases of pancreatoblastoma in children are reported here. Only biopsies were made at laparotomy as surgical resection by duodeno-pancreatectomy was not possible. In both children a dramatic response was observed with chemotherapy: doxorubicin plus cisplatin for one, cyclophosphamide, actinomycin D, bleomycin, vinblastine sulfate, and cisplatin for the other. After completion of the chemotherapy the first patient had a local resection; then he had radiotherapy. He is alive in first remission 40 months after the end of the treatment. In the second patient, regional recurrence occurred 8 months after chemotherapy was ended. A transient second remission was obtained with ifosfamide plus etoposide alternating with epirubicin plus vincristine. The patient died 36 months after the diagnosis. Therefore, these two cases suggest that chemotherapy may be proposed before any attempt at surgical excision. Nevertheless, early consolidation by radical resection or irradiation must be considered.

Adenocarcinoma↗
PubMed1991

[A prognostic study of cryptogenic infantile spasms].

The prognosis of infantile spasms is grim when a detectable brain lesion is present. In contrast, cryptogenic infantile spasms, in which there is no identifiable brain lesion, usually run a favorable course under treatment. Few studies have focused on the outcome in children with cryptogenic infantile spasms. Among 111 pediatric patients with a history of infantile spasms hospitalized over 18 consecutive years, 23 (21%) were given a diagnosis of cryptogenic infantile spasms. Follow-up ranged from 4 to 21 years. Outcome was as follows: the IQ was above 80 in 39% of cases and above 100 in 13% of cases; 42% of patients of school age were attending school but half of these had learning disabilities; 30% of patients had severe psychiatric disorders, and 22% had developmental delay and severe epilepsia. Early factors apparently associated with a good prognosis included the mild nature of psychomotor regression, persistence of spindles on EEGs recorded during NREM sleep, and prompt improvement of clinical status and EEG recordings under treatment. Conversely, severe regression, focalized EEG anomalies, failure of development to resume promptly after initiation of therapy, recurrence of spasms and hypsarrhythmia at discontinuation of treatment, and onset before 5 months or after 11 years of age were associated with a poor prognosis.

Adrenocorticotropic Hormone↗
PubMed1990

New evaluations of circulating granulocyte and macrophage stem cells in healthy adults using conditioned media and recombinant human growth factors.

Peripheral human blood contains granulo-monocyte (CFU-GM) and eosinophil (CFU-Eo) progenitors. In vitro, the number of colony forming units is thought to range from 0.1-14 per 2 x 10(5) plated cells. We show that the number of CFU-GM, Eo depends on culture methods. By modifying the usual assay method (using human umbilical cord plasma and the association of 2 stimulating conditioned media: activated lymphocyte conditioned medium and bone marrow fibroblast conditioned medium), we found different circulating CFU-GM, Eo numbers. The mean number of circulating CFU-GM, Eo in 107 healthy adults was 22.4 per 2 x 10(5) plated cells (range: 1-84). There was a slight difference between males (mean number: 23.6) and females (mean number: 20.4). The mean number of CFU-GM, Eo harvested on Percoll gradient was 123/ml of peripheral blood (range: 7-513). These results are far over those commonly reported in literature. This suggests that these latter results were probably underestimated. The use of recombinant human interleukin 3 and recombinant human GM (granulocyte-monocyte) colony-stimulating factors shows that CFU-GM, Eo numbers are found to be comparatively increased compared to that obtained with our modified method (using rhIL-3 alone), or that the size of those colonies is notably increased (using rhIL-3 + rhGM-CSF).

Adult↗
PubMed1990

Cytomegalovirus encephalopathy in an infant with congenital acquired immuno-deficiency syndrome.

A female infant born pre-term to a HIV seropositive mother presented at birth with seropositivity for HIV and CMV viruria. At five months of age she developed an AIDS-related complex. Six months later she died from rapidly progressive diffuse encephalopathy. Post mortem examination revealed generalized CMV infection. Neuropathological examination showed a nodular encephalitis with occasional cytomegalic cells containing characteristic CMV inclusion bodies. There was no evidence of HIV encephalitis; immunostaining for HIV antigen (gp 41) was negative. Opportunistic infections in infants with congenital AIDS are the exception. To our knowledge, only one case of CMV encephalitis in an infant with congenital AIDS has been reported previously. In that case, as in the present one, a reactivation of a congenital CMV infection is likely.

AIDS-Related Complex↗