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Biomedical subjects

D Lacombe

Publications and source records attributed to D Lacombe.

At least 19 recordsLinked to original sources

Phase I and pharmacokinetic study of halofuginone, an oral quinazolinone derivative in patients with advanced solid tumours.

PURPOSE: Halofuginone (tempostatin) is a synthetic derivative of a quinazolinone alkaloid showing anti-angiogenic, anti-metastatic and anti-proliferative effects in preclinical studies. The objectives of this phase I study were to assess the dose-limiting toxicities (DLTs), to determine the maximum tolerated dose (MTD) and to study the pharmacokinetics (PKs) of halofuginone when administered once or twice daily orally to patients with advanced solid tumours. METHODS: Patients were treated with escalating doses of halofuginone at doses ranging from 0.5 to 3.5 mg/day. For pharmacokinetic analysis plasma sampling was performed during the first and second course and assayed using a validated high-performance liquid chromatographic assay with mass spectrometric detection. RESULTS: Twenty-four patients received a total of 106 courses. The 'acute' MTD was reached at 3.5 mg/day, with nausea, vomiting, and fatigue as DLT. The recommended dose for chronic administration was defined as 0.5mg/day with the requirement of 5HT3 antagonists to control nausea and vomiting considered as DLT. Several patients experienced bleeding complications on treatment with halofuginone in which a causal relationship could not be excluded. The PKs of halofuginone were linear over the dose range studied with a large interpatient variability. CONCLUSIONS: In this study the DLT of halofuginone was nausea, vomiting, and fatigue. The recommended dose for phase II studies of halofuginone is 0.5mg administered orally, once daily.

Administration, Oral↗

Genotype-phenotype correlation in Costello syndrome: HRAS mutation analysis in 43 cases.

BACKGROUND: Costello syndrome (CS) is a rare multiple congenital abnormality syndrome, associated with failure to thrive and developmental delay. One of the more distinctive features in childhood is the development of facial warts, often nasolabial and in other moist body surfaces. Individuals with CS have an increased risk of malignancy, suggested to be about 17%. Recently, mutations in the HRAS gene on chromosome 11p13.3 have been found to cause CS. METHODS: We report here the results of HRAS analysis in 43 individuals with a clinical diagnosis of CS. RESULTS: Mutations were found in 37 (86%) of patients. Analysis of parental DNA samples was possible in 16 cases for both parents and in three cases for one parent, and confirmed the mutations as de novo in all of these cases. Three novel mutations (G12C, G12E, and K117R) were found in five cases. CONCLUSIONS: These results confirm that CS is caused, in most cases, by heterozygous missense mutations in the proto-oncogene HRAS. Analysis of the major phenotypic features by mutation suggests a potential correlation between malignancy risk and genotype, which is highest for patients with an uncommon (G12A) substitution. These results confirm that mutation testing for HRAS is a reliable diagnostic test for CS.

Abnormalities, Multiple↗

[Genetics and orthopedics: genetic implications of congenital limb abnormalities].

Limb malformations are frequent. These malformations are isolated or associated with anomalies of other developmental fields and accurate diagnostic is essential for prognosis evaluation, treatment and genetic counseling. Animal embryology and molecular biology techniques, have given us a better understanding of the processes of growth and patterning of the limb buds. The key genes that are involved in these processes have been identified and their interactions recognized. Human genetics has been able to identify, or at least localize, several genes implicated in limb development. We here review the present knowledge on these genes and their mutations responsible for limb anomalies.

Extremities↗

Mosaic maternal uniparental isodisomy for chromosome 7q21-qter.

Uniparental disomy (UPD) for several human chromosomes is associated with clinical abnormalities. We report the case of a 2-year-old boy with severe intrauterine and post-natal growth retardation (IUGR/PNGR) and highly variable sweat chloride concentrations. The patient was identified as heterozygous for the F508del mutation of the CFTR (cystic fibrosis transmembrane conductance regulator) gene. Unexpectedly, the signal corresponding to the maternally inherited F508del allele appeared much more intense than the paternally derived wild allele. Molecular analysis including polymorphic marker studies, microsatellites and single-nucleotide polymorphisms subsequently showed that the boy was a carrier of a de novo mosaic maternal isodisomy of a chromosome 7 segment while there was a biparental inheritance of the rest of the chromosome. This is the first report of a mosaic partial UPD7. The matUPD7 segment at 7q21-qter extends for 72.7 Mb. The karyotype (550 bands) of our patient was normal, and fluorescence in situ hybridization with probes mapping around the CFTR gene allowed us to rule out a partial duplication. The detection of this chromosomal rearrangement confirms the hypothesis that the 7q31-qter segment is a candidate for the localization of human imprinted genes involved in the control of IUGR and PNGR. It also emphasizes the importance of searching for UPD7 in severe, isolated and unexplained IUGR and PNGR.

Alleles↗

Mutational spectrum of COH1 and clinical heterogeneity in Cohen syndrome.

Cohen syndrome (CS) is an autosomal recessive disorder with variability in the clinical manifestations, characterised by mental retardation, postnatal microcephaly, facial dysmorphism, pigmentary retinopathy, myopia, and intermittent neutropenia. Mutations in the gene COH1 have been found in an ethnically diverse series of patients. Brief clinical descriptions of 24 patients with CS are provided. The patients were from 16 families of different ethnic backgrounds and between 2.5 and 60 years of age at assessment. DNA samples from all patients were analysed for mutations in COH1 by direct sequencing. Splice site mutations were characterised using reverse transcriptase PCR analysis from total RNA samples. In this series, we detected 25 different COH1 mutations; 19 of these were novel, including 9 nonsense mutations, 8 frameshift mutations, 4 verified splice site mutations, 3 larger in frame deletions, and 1 missense mutation. We observed marked variability of developmental and growth parameters. The typical facial gestalt was seen in 23/24 patients. Early onset progressive myopia was present in all the patients older than 5 years. Widespread pigmentary retinopathy was found in 12/14 patients assessed over 5 years of age. We present evidence for extended allelic heterogeneity of CS, with the vast majority of mutations leading to premature termination codons in COH1. Our data confirm the broad clinical spectrum of CS with some patients lacking even the characteristic facial gestalt and pigmentary retinopathy at school age.

Abnormalities, Multiple↗

Prenatal diagnosis of hypochondroplasia: three-dimensional multislice computed tomography findings and molecular analysis.

We report the first case of sporadic hypochondroplasia diagnosed in utero by computed tomography (CT) three-dimensional (3D) imaging and molecular analysis at 38 weeks' gestation. Prenatal sonographic examinations performed at 32 and 35 weeks' gestation revealed a rhizomelic shortness of the long bones (femur and humerus) with macrocephaly. Based on these findings, a nonlethal form of skeletal dysplasia was suspected and a multislice CT imaging with 3D reconstruction was performed depicting skeletal abnormalities which suggested hypochondroplasia. The prenatal diagnosis was confirmed by DNA mutation analysis of the fibroblast growth receptor 3 gene.

DNA Mutational Analysis↗

A case of trisomy 12 mosaicism with pituitary malformation and polycystic ovary syndrome.

We report the case of a patient (followed from birth to 15 years) presenting with trisomy 12 mosaicism, and focus on the endocrine phenotype associating a pituitary malformation and ovarian abnormalities. We describe the dysmorphic features and their evolution, the growth retardation and ovarian symptoms. Complete growth hormone deficiency was confirmed on auxological data, stimulation test and was related to pituitary stalk interruption, diagnosed by magnetic resonance imaging. Effect of growth hormone treatment was satisfactory resulting in a normal adult height. She also presented premature thelarche associated with right ovarian hypertrophy (4 to 5 fold the volume of the left ovary) which remained constant until 15 years of age. Diagnosis of trisomy 12 mosaicism was made on skin and ovarian karyotypes. The possible relation between these endocine findings and some genes located on chromosome 12 involved in pituitary and ovarian development is discussed.

Abnormalities, Multiple↗

A study from the EORTC new drug development group: open label phase II study of sabarubicin (MEN-10755) in patients with progressive hormone refractory prostate cancer.

Sabarubicin (MEN-10755), a new synthetic anthracycline analogue, was evaluated for safety and efficacy in a multicentre phase II study in patients with advanced hormone refractory prostate cancer (HRPC). Thirty seven patients were included, of which 34 were evaluable for PSA response according to Bubley's criteria. Sabarubicin was administered as a short (30 min) intravenous infusion at a dose of 80 mg/m(2) every 3 weeks. The main toxicity consisted of grade 3/4 neutropenia in 24 patients (64.9%), with grade 3/4 febrile neutropenia occurring in one patient only. Grade 3/4 cardiotoxicity was observed in 4 patients including one ineligible. Other toxicities were mild. Nine patients achieved a PSA response (26.5%), 10 patients had stable disease (29.4%) and 14 patients disease progression (41.2%). One patient (2.9%) had a PSA response that was not confirmed by repeat PSA testing. The objective response rate according to RECIST criteria was 6.7% in 15 patients with measurable disease. The median duration of PSA responses was relatively long 7.1 months (95% CI 4.9-20.7) as was the median time to treatment progression in patients with stable disease. The median overall survival was 18.7 months (95% CI 9.1-N), comparable to results recently observed in taxotere-containing regimens. To confirm and extend these results, further testing of sabarubicin in larger trials is warranted.

Aged↗

Screening of ARX in mental retardation families: Consequences for the strategy of molecular diagnosis.

Mutations in the human ARX gene have been shown to cause nonsyndromic X-linked mental retardation (MRX) as well as syndromic forms such as X-linked lissencephaly with abnormal genitalia (XLAG), Partington syndrome and X-linked infantile spasm. The most common causative mutation, a duplication of 24 bp, was found in families with a variety of phenotypes, but not in the more severe XLAG phenotypes. The aim of the study was to access the frequency of ARX mutations in families with established or putative X-linked mental retardation (XLMR) collected by the European XLMR Consortium. We screened the entire coding region of ARX for mutations in 197 novel XLMR families by denaturing high-performance liquid chromatography, and we identified eight mutations (six c.428_451dup24, one insertion and one novel missense mutation p.P38S). To better define the prevalence of ARX mutations, we included previously reported results of 157 XLMR families. Together, these data showed the relatively high rate (9.5%) of ARX mutations in X-linked MR families and an expectedly low rate in families with affected brother pairs (2.2%). This study confirms that the frequency of ARX mutations is high in XLMR, and the analysis of ARX in MRX should not be limited to duplication.

Amino Acid Sequence↗

Factor V Leiden, prothrombin 20210A, methylenetetrahydrofolate reductase 677T, and population genetics.

Thrombosis results from the interaction between predisposing genetic polymorphisms and acquired risk factors. Two of the main prothrombotic alleles, Factor V (FV) Leiden and prothrombin 20210A, are only encountered among European populations. They are estimated to have arisen about 21,000-34,000 years ago as founding mutations after the evolutionary divergence of Caucasians from Asians, and have been subsequently dispersed by the Neolithic migrations. These polymorphisms may have developed by means of genetic drift or natural selection by possibly conferring a reduced risk of bleeding. Of note, FV Leiden is nearly absent in the Basques, a European population of pre-Neolithic individualization. The C677T mutation of the methylenetetrahydrofolate reductase gene may induce hyperhomocysteinemia and could slightly increase the risk of arterial or venous thrombosis and pregnancy loss in individuals with folic acid deficiency. Through a selective phenomenon, the frequency of the mutation may parallel the intake of this vitamin within populations. Hence, this allele is underrepresented in Sub-Saharan Africa, Indonesia, and in the Inuits and a positive North to South gradient has been described in Europe. Thus, these three inherited prothrombotic polymorphisms represent interesting tools for population genetics studies.

Evolution, Molecular↗

A second locus for Aicardi-Goutieres syndrome at chromosome 13q14-21.

BACKGROUND: Aicardi-Goutières syndrome (AGS) is an autosomal recessive, early onset encephalopathy characterised by calcification of the basal ganglia, chronic cerebrospinal fluid lymphocytosis, and negative serological investigations for common prenatal infections. AGS may result from a perturbation of interferon alpha metabolism. The disorder is genetically heterogeneous with approximately 50% of families mapping to the first known locus at 3p21 (AGS1). METHODS: A genome-wide scan was performed in 10 families with a clinical diagnosis of AGS in whom linkage to AGS1 had been excluded. Higher density genotyping in regions of interest was also undertaken using the 10 mapping pedigrees and seven additional AGS families. RESULTS: Our results demonstrate significant linkage to a second AGS locus (AGS2) at chromosome 13q14-21 with a maximum multipoint heterogeneity logarithm of the odds (LOD) score of 5.75 at D13S768. The AGS2 locus lies within a 4.7 cM region as defined by a 1 LOD-unit support interval. CONCLUSIONS: We have identified a second AGS disease locus and at least one further locus. As in a number of other conditions, genetic heterogeneity represents a significant obstacle to gene identification in AGS. The localisation of AGS2 represents an important step in this process.

Basal Ganglia Diseases↗

[Angelman syndrome and intracranial aneurysm: fortuitous association or commune genetic predisposition?].

Although the pathogenesis of cerebral aneurysms has been studied intensively, it is yet poorly understood. However, a genetic predisposition to this pathology has been often suspected. We describe a patient with both intracranial aneurysm and Angelman syndrome. Angelman syndrome is characterized by severe mental retardation, inappropriate laughter, absent speech, dysmorphic facial features and seizures. It is due to genetic abnormalities of chromosome 15. Cerebral aneurysms are sometimes associated with inherited diseases like autosomal dominant polycystic kidney disease. Moreover several candidate genes have been analysed, to search for genetic variants which might be associated with the occurrence of intracranial aneurysms. Our question is: is the association described in our observation fortuitous or do these diseases share a same genetic predisposition? Our observation also supports the hypothesis of a genetic participation in the genesis of cerebral aneurysms.

Angelman Syndrome↗

Multicentre EORTC study 16997: feasibility and phase II trial of farnesyl transferase inhibitor & gemcitabine combination in salvage treatment of advanced urothelial tract cancers.

In this study, the feasibility and activity of combined chemotherapy of the farnesyl transferase inhibitor SCH66336 and gemcitabine was evaluated. This therapy was used as second-line treatment in patients with advanced urothelial tract cancer and the influence of SCH66336 exposure on the pharmacokinetics of gemcitabine was also determined. Patients who had received one previous chemotherapy regime for advanced urothelial cancer were treated with a combination of SCH66336 (150 mg in the morning and 100 mg in the evening) and Gemcitabine (1000 mg/m2 on day 1, 8 and 15 per 28-day cycle). Dosages of gemcitabine and its metabolite dFdU were performed on day one of cycle 1 before exposure to SCH66336 and day one of cycle 2. A total of 152 cycles were administered in 33 patients (median 3, range: 1-15). No patients had severe hematological toxicity, defined as Grade 4 thrombocytopenia or febrile neutropenia. Nine partial responses and one complete response were achieved in 31 assessable patients and corresponded to an overall response rate of 32.3% [95% CI:17%-51%]. There was no influence of exposure to SCH66336 on the level of gemcitabine or dFdU in 11 assessable patients. In conclusion, a combination of SCH66336 and gemcitabine is feasible in terms of toxicity and active as second-line treatment in patients with advanced urothelial tract cancer. SCH66336 had no effect on the pharmacokinetics of gemcitabine. Randomised trials should be undertaken to clarify the role of SCH66336 in combination with gemcitabine in cancer treatment.

Adult↗

Mutations in PHF8 are associated with X linked mental retardation and cleft lip/cleft palate.

Truncating mutations were found in the PHF8 gene (encoding the PHD finger protein 8) in two unrelated families with X linked mental retardation (XLMR) associated with cleft lip/palate (MIM 300263). Expression studies showed that this gene is ubiquitously transcribed, with strong expression of the mouse orthologue Phf8 in embryonic and adult brain structures. The coded PHF8 protein harbours two functional domains, a PHD finger and a JmjC (Jumonji-like C terminus) domain, implicating it in transcriptional regulation and chromatin remodelling. The association of XLMR and cleft lip/palate in these patients with mutations in PHF8 suggests an important function of PHF8 in midline formation and in the development of cognitive abilities, and links this gene to XLMR associated with cleft lip/palate. Further studies will explore the specific mechanisms whereby PHF8 alterations lead to mental retardation and midline defects.

Animals↗

[Hereditary neuralgic amyotrophy: a paediatric and familial presentation of Parsonage-Turner syndrome].

Hereditary neuralgic amyotrophy is a rare disorder, characterized by recurrent attacks of pain in a brachial plexus distribution. We report the case of a 12-year-old boy with several attacks of pain and atrophy of the muscles of the shoulders. The age of onset of this disease is variable, most frequently in the second or third decade. Pediatric onsets, during the first decade are rare. The differences between the hereditary neuralgic amyotrophy and the sporadic Parsonage-Turner syndrome are painful recurrent episodes of weakness and similar familial cases. The analysis of several families has shown that hereditary neuralgic amyotrophy phenotype is heterogeneous and two different clinical courses can be discerned. Recent evidence indicates that HNA is genetically heterogeneous. Pathophysiology of the disease remains unclear, so the treatment is not clearly established.

Age of Onset↗

Glufosfamide administered by 1-hour infusion as a second-line treatment for advanced non-small cell lung cancer; a phase II trial of the EORTC-New Drug Development Group.

The activity of glufosfamide (beta-D-glucosylisophosphoramide mustard) was tested in a multicentre phase II clinical trial in patients with advanced non-small cell lung cancer (NSCLC) who had received one prior line of platinum-based chemotherapy. Patients were treated with 5000 mg/m(2) glufosfamide by a 1-h intravenous (i.v.) infusion every 3 weeks following registration at the European Organisation for Research and Treatment of Cancer (EORTC) Data Center. Patients were randomised between hydration and no hydration to evaluate the nephroprotective effects of forced diuresis. Patients experiencing >/= 35 micromol/l increase of serum creatinine compared with baseline values were taken off the treatment. The Response evaluation criteria in solid tumours (RECIST) criteria were applied for the response assessment. Blood sampling was performed for a pharmacokinetic analysis. 39 patients from seven institutions were registered and a median of three cycles was given (range 0-6) cycles; 20 patients were randomised to the hydration arm. Haematological toxicity was mild, but treatment-related metabolic and electrolytic abnormalities and increases of serum creatinine occurred in several patients. Hydration did not have any significant influence on the plasma pharmacokinetics of glufosfamide and did not show any nephroprotective effect. Only one confirmed partial remission was observed (response rate 3%; 95% (Confidence Interval (CI) 0-14) and 18 cases with stable disease (49%) were recorded as assessed by an independent panel. Median survival of all patients treated was 5.8 months (95% CI 4.2-7.9). In conclusion, glufosfamide administered by a 1-h infusion every 3 weeks has modest activity in advanced NSCLC patients after one prior platinum-based chemotherapy.

Adolescent↗

RFS2000 (9-nitrocamptothecin) in advanced small cell lung cancer, a phase II study of the EORTC New Drug Development Group.

Camptothecins have shown efficacy in terms of response rate in patients with small cell lung cancer (SCLC). RFS2000 is a new camptothecin derivative, which has shown objective responses in various tumour types. The aim of this phase II study was to determine the objective response rate of RFS2000 in patients with sensitive and refractory SCLC. RFS2000 was given orally at 1.5 mg/m(2) per day for five consecutive days (five days on - two days off) on a continuous basis. Patients were evaluated weekly for toxicity and every six weeks for response. Thirty seven patients were included, 36 patients (14 with sensitive and 22 with refractory SCLC) were evaluable for toxicity, and 35 patients were evaluable for response. No objective responses were observed. Toxicity was acceptable, with myelosuppression, nausea/vomiting, and diarrhoea as the main toxicities. RFS2000 therefore has an acceptable toxicity profile but is not active as a single agent in SCLC.

Aged↗