Biomedical subjects

R Kodet

Publications and source records attributed to R Kodet.

At least 55 records · Page 3Linked to original sources

PubMed1999

Papillary cystic and solid tumor of the pancreas--surgical therapy with the use of CUSA, and a review of the pediatric literature.

Papillary cystic and solid tumor of the pancreas (PCSTP), so-called Frantz tumor, is a very rare tumor in children. Only 62 cases, 57 girls and 5 boys, have been reported in children since 1959. The tumor presents usually as a slowly growing abdominal mass with or without abdominal pain. Surgical resection of the tumor is an adequate mode of treatment, and the prognosis is excellent. The authors present 4 girls and 1 boy with PCSTP and demonstrate that the Cavitron Ultrasonic Surgical Aspirator (CUSA, Valleylab) is successfully used in surgical therapy.

Adolescent↗

PubMed1999

[Primary lung tumors in childhood].

The authors give an account of their experience with the treatment of primary lung tumours in children during 1989-1998. Primary lung tumours in children are extremely rare and represent a varied spectrum of pathological conditions (pneumoblastoma, rhabdomyosarcoma, mucoepidermoid carcinoma, pulmonary endodermal tumour and benign tumours). During the mentioned period 10 children were operated on account of primary lung tumours, 5 with malignant tumours and 5 with benign tumours. In these patients during the above period 3 pneumonectomies, 5 lobectomies and 3 segmental resections were made. Chemotherapy was indicated in children with pneumoblastoma and rhabdomyosarcoma. Two patients with pneumoblastoma died, 3 children with malignant and 5 children with benign tumours live without symptoms of the disease.

Adolescent↗

PubMed1998

A database of germline p53 mutations in cancer-prone families.

We created a comprehensive database covering all published cases of germline p53 mutations. The current version lists 580 tumours in 448 individuals belonging to 122 independent pedigrees. The database describes each p53 mutation (type of the mutation, exon and codon affected by the mutation, nucleotide and amino acid change), each family (family history of cancer, diagnosis of Li-Fraumeni syndrome), each affected individual (sex, generation, p53 status, from which parent the mutation was inherited) and each tumour (type, age of onset, p53 status-loss of heterozygosity, immunostaining). Each entry contains the original reference(s). The database is freely available and can be obtained from http://www.lf2.cuni.cz

Computer Communication Networks↗

PubMed1998

Allele loss in Wilms tumors of chromosome arms 11q, 16q, and 22q correlate with clinicopathological parameters.

An extended analysis for loss of heterozygosity (LOH) on eight chromosomes was conducted in a series of 82 Wilms tumors. Observed rates of allele loss were: 9.5% (1p), 5% (4q), 6% (6p), 3% (7p), 9.8% (11q), 28% (11p15), 13.4% (16q), 8.8% (18p), and 13.8% (22q). Known regions of frequent allele loss on chromosome arms 1p, 11p15, and 16q were analyzed with a series of markers, but their size could not be narrowed down to smaller intervals, making any positional cloning effort difficult. In contrast to most previous studies, several tumors exhibited allele loss for multiple chromosomes, suggesting an important role for genome instability in a subset of tumors. Comparison with clinical data revealed a possible prognostic significance, especially for LOH on chromosome arms 11q and 22q with high frequencies of anaplastic tumors, tumor recurrence, and fatal outcome. Similarly, LOH 16q was associated with anaplastic and recurrent tumors. These markers may be helpful in the future for selecting high-risk tumors for modified therapeutic regimens.

Alleles↗

PubMed1998

Amebic encephalitis caused by Balamuthia mandrillaris in a Czech child: description of the first case from Europe.

We describe a fatal case of amebic encephalitis caused by Balamuthia mandrillaris in a 3-year-old Czech boy who had never traveled abroad. This is the first such infection reported in Europe. The diagnosis was established by brain biopsy, in which abundant trophozoites and a few round amebic cysts were identified. The presence of multiple nucleoli in some trophozoites suggested the organism to be Balamuthia mandrillaris and this was confirmed by indirect immunofluorescence. The amebae invaded brain tissue, including neurons, and blood vessel walls, causing thrombovasculitis. The tissue reaction was a subacute necrotizing and granulomatous encephalitis (GAE) with an infiltrate of CD4- and CD8-positive T-lymphocytes, B-lymphocytes, plasma cells and macrophages. The child, in whom no underlying immunodeficiency was demonstrated, died after 45 days. The mode of infection was not established. Postmortem examination of the brain revealed massive areas of necrosis and microscopic findings like those in the surgical specimen. In vitro isolation of B. mandrillaris was unsuccessful.

Amebiasis↗

PubMed1998

Retinal detachment in an infant with the ring chromosome 13 syndrome.

PURPOSE: To inform about retinal detachment in an infant with the ring chromosome 13 as a possible new feature of this syndrome. The finding is able to imitate retinoblastoma, which is closely connected to the deletion of 13q14. METHODS: We report on a girl with many congenital anomalies including hypoplasia of both optic discs and chorioretinal coloboma of the right eye. Chromosomal analysis revealed karyotype 46 XX with a ring chromosome 13. The patient was examined again at 15 months of age, where leukocoria was disclosed in the left eye, emerging from a retrolental greyish-white mass. Even though neither sonography nor CT showed a typical picture for retinoblastoma, this tumor could not be ruled out. Enucleation of the left eye was performed. The globe was then investigated histopathologically. RESULTS: No tumor was found in the removed eye. Microscopic examination showed a detached retina with reactive gliosis and neovascularisation. CONCLUSIONS: The possibility of retinal detachment should be included into differential diagnoses in infants with ring 13 chromosome in cases with a non-specific intraocular mass. The assessment of chromosomal breakpoints in children with this aberration would enable clinicians to determine the real risk of retinoblastoma.

Abnormalities, Multiple↗

PubMed1998

Two Li-Fraumeni syndrome families with novel germline p53 mutations: loss of the wild-type p53 allele in only 50% of tumours.

We describe two Li-Fraumeni syndrome families. Family A was remarkable for two early childhood cases of adrenocortical tumours, family B for a high incidence of many characteristic cancers, including a childhood case of choroid plexus tumour. Using direct sequencing, we analysed exons 5-9 of the p53 gene in constitutional DNA of individuals from both families and found two novel germline mutations in exon 5. In family A, we detected a point substitution in codon 138 (GCC to CCC), which resulted in the replacement of the alanine by a proline residue. Family B harboured a single-base pair deletion in codon 178 (CAC to -AC), resulting in a frameshift and premature chain termination. Three out of six tumours examined from both families, a renal cell carcinoma, a rhabdomyosarcoma and a breast cancer, showed loss of heterozygosity and contained only the mutant p53 allele. The remaining three neoplasms, both adrenocortical tumours and the choroid plexus tumour retained heterozygosity. Immunohistochemistry with anti-p53 antibody confirmed accumulation of p53 protein in tumours with loss of heterozygosity, while the remaining tumours were p53 negative. These results support the view that complete loss of activity of the wild-type p53 need not be the initial event in the formation of all tumours in Li-Fraumeni individuals.

Adolescent↗

PubMed1998

Oncogene amplification and expression in pediatric solid tumors.

Oncogene amplification and expression and their mutual relationship was analyzed in 92 pediatric tumors by Southern and Northern blot hybridization with N-MYC, ERB A, ERB B, N-RAS and Shb probes. Amplification and overexpression was associated with more advanced clinical stages of tumor, especially in neuroblastomas, rhabdomyosarcomas and ganglioneuroblastomas. The most frequent alteration observed was N-MYC amplification together with overexpression. N-RAS amplification was not detected, while the overexpression of this oncogene was found in 3 cases. Neither amplification nor overexpression was revealed in any specimen of hepatoblastoma or hepatocellular carcinoma. We suggest that oncogenes overexpression provides more accurate prognostic information than amplification.

Child↗

PubMed1998

Ultrastructural observations on neuroblastic tumors in childhood: a study of tumor cell differentiation and regression on 89 cases.

The study presents ultrastructural findings in 89 neuroblastic tumors. All of them including 21 undifferentiated neuroblastomas (NB) were characterized by neural cell processes which contained neurofilaments, mitochondria and neurosecretory granules. The granules were generally sparse and their number and distribution was a feature independent on other signs of differentiation of the tumor cells. We found degenerative changes in the tumor cell bodies and their neuronal processes to be a prominent phenomenon in neuroblastic tumors. Although they occurred both in patients who were operated primarily and in those who received a preoperative chemotherapy they were most conspicuous in the latter group (28 of 80 patients). The degenerative changes included swelling and dilatations of the neuronal processes, accumulation of heterophagosomes, myelinated bodies and cytoskeletal filaments. Some ganglion cells had dilated endoplasmic reticulum, and contained lipofuscin. In one ganglioneuroblastoma we detected dense granulated bodies resembling neuromelanin. The diagnosis of undifferentiated NB was established on the basis of ultrastructural investigations in 13 out of 21 undifferentiated NB; in the remaining 8 cases the electron microscopy was an additional confirmatory tool together with the results of immunohistochemical reactions. The electron microscope is still a valuable instrument for diagnosis of neuroblastic tumors in addition to newer diagnostic approaches such as immunohistochemical and molecular investigations.

Child↗

PubMed1998

[Detection of monoclonality in childhood lymphoma with the polymerase chain reaction].

We studied monoclonality of tumour cells by polymerase chain reaction (PCR) in paediatric lymphomas. In B-lymphomas we detected monoclonal rearrangement of the immunoglobulin of the T-cell receptor delta and gamma chain (TCR, TCR-delta, TCR-gamma) by an analogous way. We examined a group of 37 paediatric patients with lymphomas (26 with B-lymphomas and 11 with T-lymphomas). Monoclonal gene rearrangement was found in 34 cases, i.e. the method used in this study proved to be successful in 92% of cases. We confirmed our results by correlation with histologic and immunohistologic diagnoses. The method may be used as a complementary diagnostic tool in differential diagnosis of lymphoma versus non-neoplastic proliferation of lymphatic tissue, in distinction between B- and T-lymphomas, and to separate lymphomas and other malignancies. Beside the pure diagnostic usage we perceive the main importance of the method in monitoring minimal residual disease (MRD), because amplified products of PCR may be sequenced and used for preparing tumour specific primers and probes.

Child↗

PubMed1997

Orbital rhabdomyosarcomas and related tumors in childhood: relationship of morphology to prognosis--an Intergroup Rhabdomyosarcoma study.

Children and adolescents who develop rhabdomyosarcoma (RMS) and related sarcomas in the orbit and treated on Intergroup Rhabdomyosarcoma protocols have had an extremely high cure rate. This study evaluates the possible relationship between their tumor morphologic subtypes and this high cure rate. The histology of tumors was re-reviewed from 229 of the 264 patients with tumors of the orbit, conjunctiva, and eyelids treated on Intergroup Rhabdomyosarcoma Studies (IRS I, II, III, and IV pilot protocols, and followed through July, 1992. Immunohistochemistry was applied in selected cases. Clinical correlations were done on all 264 cases including both the re-reviewed cases and those reviewed only by the IRS Pathology committee. The 5-year survival rate of 24 children with alveolar RMS was 74% (p < .001). All five infants diagnosed to have an alveolar RMS died before the age of one. Two hundred and twenty-one patients (84%) had embryonal RMS. About three-fourths of the re-reviewed embryonal RMS tumors showed only minimal rhabdomyoblastic differentiation. Thirty-one had a spindle cell RMS, two were anaplastic variants. The 5-year survival rate for patients with embryonal RMS subtypes combined was 94%, and 97% for the 144 patients with poorly differentiated embryonal RMS. In contrast, 90 of 432 IRS II patients treated for poorly differentiated embryonal RMS located in extraocular sites had a 66% survival estimate.

Adolescent↗

PubMed1997

Surgical tactics in the treatment of malignant renal tumors in childhood.

The authors report the treatment results of 89 children with renal tumors (excluding carcinoma) seen from 1988 to 1992, 71 (79.8%) with favorable-histology Wilms' tumor (survival 86%) and 18 (20.2%) with unfavorable histology, including anaplastic nephroblastoma, clear-cell sarcoma, and rhabdoid tumor (survival 61%). Preoperative chemotherapy (ChT) was given to 46 patients (survival 84%); none was given to 43 with either tumors in the 1st year of life, massive hematuria, or tumor growth during ChT (survival 78%). There were 3 tumor ruptures in the latter group compared to 1 in the former group.

Chemotherapy, Adjuvant↗

PubMed1997

[N-myc oncogene amplification in tumors of the sympathetic nervous system: preliminary study of methods and clinico-pathologic correlations].

Tumors of the sympathetic nervous system (NT), namely neuroblastoma (NB) and ganglioneuroblastoma (GNB), have a variable clinical course. Prognostic factors include clinical stage, age of the patient, histological grade, and changes at the genomic level, of which amplification of N-myc oncogene is a well recognized phenomenon. The aim of this study was to establish the status of the N-myc oncogene in NT and to compare the results with histopathological grading, with risk groups according to criteria outlined by Joshi et al., and with the clinical stage. To detect the amplification of N-myc oncogene we used differential polymerase chain reaction (D-PCR). Amplified N-myc oncogene was found in 10 out of 31 investigated children with NB (32%). The result of D-PCR could not be interpreted reliably in two patients. Of seven children with GNB the N-myc amplification was found in one case. None of seven children with ganglioneuroma was found to have amplified N-myc oncogene. The tumors with N-myc amplification were histologically poorly differentiated of undifferentiated with a high mitotic activity-8 children were classified as a high risk category; in two we had not enough surgical material to evaluate the histological prognostic factors. The correlation of N-myc status with clinical stage revealed N-myc amplification in two of 9 children classified as clinical stage III, and in eight of 11 children classified as clinical stage IV. The N-myc amplification was not found in any child diagnosed at stage I, II and IV. Five of 10 children with NB and N-myc amplification died of the disease progression. Four children died in the group of 19 children without N-myc amplification. The median of follow-up was 18 months. The patient with GNB and N-myc amplification also died of the disease progression. Although the follow-up period of the investigated group of patients was short, the results showed that the amplification of N-myc oncogene was associated with tumors of patients diagnosed at a late clinical stage (III and IV), and with tumors whose morphology and age were assessed collectively under the term "high risk group".

Child↗

PubMed1996

[Amplification of oncogenes in solid tumors in children].

BACKGROUND: The objective of the work was detection of amplification of oncogenes N-MYC, N-RAS, C-ERB A, C-ERB B and adaptor tyrosine kinase Shb in a group of 92 child age tumours in an attempt to reveal clinical and histopathological associations. METHODS AND RESULTS: Amplifications of oncogenes were detected by means of Southern's transfer, hybridization with labelled probes and densitometric evaluation. Amplification of the N-MYC oncogene in child tumours can be considered a manifestation of progression of the disease with an adverse prognosis, in particular in neuroblastomas, where it corresponds also with the adverse histological finding. In a group of sarcomas N-MYC amplification was detected in advanced clinical stages, while in malignant lymphogranulomas of the Hodgkin type it was not found. In Wilms tumour it was detected sporadically. Amplifications of oncogenes ERB A and ERB B are rare, amplifications of the oncogene RAS were not observed. Coamplifications characterized progression of the disease, in case of neuroblastoma even very short survival. In hepatic malignancies oncogene amplification was not found even in advanced stages. CONCLUSIONS: Oncogene amplification characterizes progression in a number of child tumours and its application in clinical oncology is prognostically useful.

Child↗

PubMed1996

Congenital-infantile fibrosarcoma: a clinicopathological study of five patients entered on the Prague children's tumor registry.

Five children with congenital-infantile fibrosarcoma are analyzed. The tumor was found at birth in four children: in one patient it was recognized at the age of 7 months. In three children the tumor affected the lower extremity. In one patient the inguinal region was the primary site, in another the abdominal wall. The morphology was that of a highly cellular spindle cell sarcoma with cells arranged in a fascicular pattern. Variations of this common pattern such as a cartwheel arrangement, and foci of small oval cells were observed. The immunohistochemistry revealed positivity of vimentin in four investigated tumors and muscle specific actin in three. Desmin, sarcomeric actin and myoglobin were all negative. There were scattered cells positive with KP1 (CD68), MAC 387, and in one case, with factor XIIIa antibodies which were considered to be reactive rather than tumor cells. The flow cytometry study showed DNA content in three tumors within diploid range; one tumor was hyperdiploid with the DNA index 1.2. Three children are disease-free from nine to 21 years after the diagnosis. One of them had the tumor preoperatively irradiated, and the subsequent histological examination revealed an almost complete tumor necrosis. In one patient there were six recurrences (treated by surgery only), and the child is well 25 months after the last recurrence. In one child the disease had an unusually aggressive course, and the patient died of widespread metastases to the lungs, lymph nodes and bones.

Abdominal Neoplasms↗

PubMed1996

DNA ploidy in neuroblastoma.

Neuroblastoma is perhaps the most heterogeneous childhood cancer in terms of clinical behavior. Stage of disease, age at diagnosis, levels of urinary catecholamine excretion, N-myc amplification, and DNA ploidy have been found to be significant prognostic factors. The aims of this combined retrospective-prospective study are to verify the prognostic significance of DNA ploidy and to show its correlation with other prognostic signs. Thirty six fresh and thirty three paraffin embedded samples from patients with histologically confirmed neuroblastoma (41 prior to receiving any chemotherapy) were available for flow cytometry DNA analysis. Our results showed that the maturation induced during chemotherapy could give rise to aneuploidy therefore we analyzed the associations between the DNA ploidy and other prognostic markers only in patients examined before chemotherapy. There were no significant correlations between DNA ploidy and urinary catecholamine metabolites levels or tumor localization. DNA aneuploidy was significantly more frequent in patients with lower clinical stage, lower age at diagnosis, and without N-myc gene amplification. Patients with DNA aneuploid neuroblastomas died less frequently than patients with DNA diploid tumors. There were no significant associations among the S-phase or proliferation fraction and other prognostic factors.

Catecholamines↗

PubMed1996

[Sinus histiocytosis with massive lymphadenopathy--a disseminated form of the Rosai-Dorfman syndrome].

A 20 year-old black male presented with a generalized lymphadenopathy, skin papules with maximum involvement of the head and trunk region, and elevated temperature. Ultrasound, CT and bone scans revealed infiltration of the kidneys and bones. Surgical specimens of the cervical lymph nodes showed massive infiltration of sinuses by histiocytes with engulfed lymphocytes and granulocytes in their cytoplasm. A similar finding was found in the excised dermis and nasopharyngeal mucosa. Immunohistochemical investigations showed a strong positive reaction of sinusoidal macrophages with anti S100 protein, anti alpha-1 antitrypsin and alpha-1 antichymotrypsin antibodies, negative CD1a. The engulfed granulocytes were positive with lysozyme and MAC387 antibodies; lymphocytes reacted with antilymphocytic antibodies L26, HLADR, UCHL-1 and OPD4 only rarely, possibly due to alterations of their cell membranes in the cytoplasmic environment of histiocytes. Occasional plasma cells were also entrapped in the macrophages. The best results were obtained with CD3 antibody which showed focal predominance of phagocytosed T cells. These findings confirm a nonselective nature of the emperipolesis. In situ hybridization with probes EBER and BHLF against Epstein-Barr virus sequences was negative. The pacient was treated by multidrug chemotherapy with a moderate regression of the infiltrates. The symptoms of the disease persisted for 10 months from the treatment start but further course of the disease is uncertain. The patients is lost to follow up.

Adult↗

PubMed1995

[Indications for liver resection in childhood].

The authors give an account of indications for resection of the liver in childhood which comprise extensive injuries, cysts, vascular malformations and primary (benign and malignant) and secondary tumours. During the period between 1986 and 1993 34 major resections of the liver were performed and examined. Indications for resection were in 17 cases hepatoblastomas, 4x metastasis, 3x hepatocellular carcinoma, 2x haemangioendothelioma, adenoma, hamartoma and in one case each necrosis after injury, a cyst, cavernous haemangioma and sarcoma. The mean age of the operated children was 4 years and 5 months, the youngest patient was operated on the age of 4 days and the oldest was 17 years old. During the period between 1986 and 1989 the survival rate was 33%. During the period between 1990 and 1993 the survival rate was 86.5%. The authors emphasize the radical character of operations of malignant tumours which has a marked impact on the survival of patients with these disease.

Adolescent↗