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C Sultan

Publications and source records attributed to C Sultan.

At least 37 records · Page 2Linked to original sources
PubMed1991

[Physiopathology of androgen insensitivity syndromes. Contribution of molecular biology].

Molecular genetic study of androgen insensitivity syndrome is now easier by the development of powerful molecular tools. Complementary DNA of the androgen receptor gene has been recently cloned and sequenced. The development of cDNA probes gave the opportunity to study DNA restriction fragment length polymorphisms of patients with complete or partial androgen insensitivity syndrome. These studies demonstrated that deletions are rarely observed. Using PCR and sequencing of exons, several groups described point mutations within the androgen receptor gene. Enzymatic amplification along with denaturing gradient gel electrophoresis and single strand conformational polymorphism study allowed the description of new mutations. These powerful tools together with mRNA study, expression of muted gene, anti-receptor study had also permitted to analyze correlations between structure-function activity of the androgen receptor gene in patients with androgen insensitivity syndrome.

Androgens↗
PubMed1990

The novel inositol lipid phosphatidylinositol 3,4-bisphosphate is produced by human blood platelets upon thrombin stimulation.

Radioactive PtdIns(3)P was detected in human platelets incubated with [32P]Pi, but remained unaffected by thrombin treatment. In contrast, [32P]PtdIns(3,4)P2 was absent from resting platelets, but was produced by thrombin-activated platelets in a dose- and time-dependent manner. [32P]PtdInsP3 was never found under these conditions. These changes are similar to those elicited in other cells by platelet-derived growth factor or the oncogene product pp60c-src.

Blood Platelets↗
PubMed1990

Defective, deleted or converted CYP21B gene and negative association with a rare restriction fragment length polymorphism allele of the factor B gene in congenital adrenal hyperplasia.

Defects in the enzyme, steroid 21-hydroxylase, result in congenital adrenal hyperplasia (CAH), a common autosomal recessive disorder of cortisol biosynthesis. The gene encoding this protein (CYP21B) and a closely linked pseudogene (CYP21A) have been mapped in the HLA complex on chromosome 6p, adjacent to the complement genes C4B and C4A, about 80 kb from the factor B gene. Molecular analyses of patients with CAH have shown that the cause of the defect may be either a deletion, a point mutation or a conversion of the active gene. Linkage of the disease to HLA has previously been studied by several groups. We have analyzed DNAs from patients with classical and non-classical CAH and from their family members, by probing with CYP21, C4 and BF cDNAs. In 70% of the CAH haplotypes studied, the defective CYP21B gene was indistinguishable from its structurally intact corresponding gene in Southern blot analysis, and presumably bore point mutations. In the remaining chromosomes, evidence for gene conversions, deletions and various deleterious mutations of the CYP21B gene is given. Moreover, our linkage studies show that a polymorphic TaqI cleavage site in the factor B gene, recently described by us, may be a new and useful genetic marker, because we found this TaqI restriction site only in unaffected haplotypes carrying functional CYP21B genes and, therefore, in negative association with the defective CYP21B gene.

Adrenal Hyperplasia, Congenital↗
PubMed1990

[Molecular genetics of 21-hydroxylase deficiency in congenital adrenal hyperplasia].

21-hydroxylase gene analysis was performed on the genomic DNA from patients with congenital adrenal hyperplasia (CAH), their siblings, their parents as well as from a healthy individual serving as control. After digestion by the Taq I and Bgl II restriction enzymes, DNA was hybridized with specific nucleotidic probes: pC21a for the 21-hydroxylase genes, pAT-A for the C4 component Complement genes, closely linked to the 21-hydroxylase genes on the 6 chromosome. Likewise the pFB3B probe was used for the B factor gene located 80 kilobases upstream the 21-hydroxylase gene. From this molecular analysis on 11 families, we report here 4 investigations showing the most frequent genetic abnormalities we have encountered: gene deletions, gene conversions and point mutations. These data show that the molecular approach is a powerful tool for studying this endocrine disease at the clinical, genetic and fundamental point of view.

Adrenal Hyperplasia, Congenital↗
PubMed1990

CYP21B gene conversion and complete CYP21A gene deletion in congenital adrenal hyperplasia.

We studied a family in which one out of two children presented a non-salt wasting form of CAH. Genomic DNA of the patient, his brother, his parents and a normal control were digested by the Taq I and Bgl II restriction enzymes. The fragments were electrophoresed, transferred onto a nitrocellulose membrane and hybridized with two specific probes: pC21a for the CYP21 genes and pAT-A for the C4 genes. We performed simultaneous RFLP analyses of the CYP21 and C4 genes and determined the relative hybridization intensity of the genes using scanning densitometry of the X-ray films. The affected child had a CYP21B gene conversion in the CYP21A pseudogene on one chromosome inherited from his mother and a mutated CYP21B gene on the second chromosome inherited from his father. The second maternal chromosome, inherited by the unaffected brother, presented an unusual CYP21A gene deletion without a C4A or C4B gene deletion. Although CYP21A is a pseudogene, this type of complete CYP21A gene deletion associated with a CYP21B gene conversion has never been previously described.

Adrenal Hyperplasia, Congenital↗
PubMed1990

[Study of growth hormone gene in non-familial complete somatotropin deficiency].

Familial growth hormone deficiency has been often associated to homozygous gene deletions. In this work we have looked for the possible absence of this gene in patients with isolated GH deficiency. The patient genomic DNAs have been digested with two restriction enzymes and hybridized with a 32P labelled growth hormone cDNA. The presence of the growth hormone gene has been proved in the patients. This situation, in which the gene is present but not expressed, might be due to changes in gene regulation or to punctual gene deletions or mutations.

Child↗
PubMed1990

The myelodysplastic syndromes.

The myelodysplastic syndromes are a group of diseases mainly afflicting the elderly of unknown aetiology manifesting with clinical and laboratory manifestations of ineffective haematopoiesis. This review discusses the clinical and morphological features of the syndrome followed by a critical appraisal of the French American British (FAB) group classification. The presenting symptoms are usually non-specific and relate to the peripheral cytopenia(s). The marrow is invariably hyperplastic with peripheral cytopenia(s) together with characteristic trilineage dysplastic morphological changes. Prognostic stratification and treatment are outlined. Lack of effective treatment of this syndrome remains an outstanding problem.

Humans↗
PubMed1990

[Leukocyte differential of the Coulter VCS. Evaluation and modalities of use in comparison with the Coulter STKR and manual count].

The Coulter VCS is a flow cytometer which performs, from a 100 microliter blood sample, a full five-part differential by assessing the volume (V), high frequency conductivity (C) and laser light scatter (S) on each white cell counted. The authors evaluated the Coulter VCS and compared its results with those of the Coulter STKR (three-part differential) and of the manual count. Reproducibility (ten replicate analyses on six different normal samples) was studied by the three methods and showed coefficients of variation closed to the manufacturer's specifications except for monocytes. The correlation coefficients obtained from 345 normal samples were the following: VCS/manual count: 0.97 for neutrophils, 0.70 for eosinophils, 0.97 for lymphocytes and 0.57 for monocytes; VCS/STKR: 0.99 for granulocytes, 0.99 for lymphocytes and 0.70 for monocytes. Comparisons of means displayed statistical differences for some cell categories but without clinical consequences. The flag analysis of 313 abnormal samples showed a false positive rate of 3.1 p. cent for the VCS and 1.8 p. cent for the STKR, the false negative rate was 2.1 p. cent for the VCS and 3.6 p. cent for the STKR. Starting from total blood count parameters, the authors propose guidelines for appropriate use of the different leucocyte differential methods.

Algorithms↗
PubMed1989

Proposals for the classification of chronic (mature) B and T lymphoid leukaemias. French-American-British (FAB) Cooperative Group.

Peripheral blood, bone marrow films, and bone marrow biopsy specimens from 110 patients, well characterised by clinical and laboratory studies, including electron microscopy, were reviewed, to determine proposals for the classification of chronic (mature) B and T cell leukaemias. On the basis of cytology and membrane phenotype the following disorders were defined: (i) B cell type: chronic lymphocytic leukaemia (CLL); CLL of mixed cell type, which includes cases with more than 10% and less than 55% prolymphocytes (CLL/PL), and a less well defined form with pleomorphic lymphocytes but less than 10% prolymphocytes; prolymphocytic leukaemia (PLL); hairy cell leukaemia (HCL); HCL variant; splenic lymphoma with circulating villous lymphocytes; leukaemic phase of non-Hodgkin's lymphoma (follicular lymphoma, intermediate, or mantle zone lymphoma and others); lymphoplasmacytic lymphoma with peripheral blood disease (mostly Waldenström's macroglobulinaemia); and plasma cell leukaemia. (ii) T cell type: T/CLL, which was differentiated from reactive T/lymphocytosis; T/PLL; adult T cell leukaemia/lymphoma; and Sézary's syndrome. The recognition of distinct entities within the B and T cell leukaemias seems to have clinical and epidemiological connotations. It is hoped that these proposals may serve as the basis for further work, discussion, and improved management of patients.

Adult↗
PubMed1989

An expert system applied to the diagnosis of anemia with special reference to myelodysplastic syndromes.

An expert system is described that includes interpretation of the results from a complete blood count as well as data from bone marrow aspiration. The system utilizes Bayes' rule. It has previously been tested on 180 cases of anemia including 20 benign and malignant hematologic disorders. On the data set, the system achieved 84% satisfactory diagnoses. In the present study, patients with myelodysplastic syndromes and with disorders of heme synthesis have been added to the test cases. For support, the expert system requires an IBM Personal Computer or equivalent. The program is available commercially (Coulter Electronics, Hialeah, FL).

Anemia↗
PubMed1989

Adult patients presenting with pancytopenia: a reappraisal of underlying pathology and diagnostic procedures in 213 cases.

We reviewed 213 consecutive adult pancytopenic patients to determine the frequency of underlying pathology, to analyze our diagnostic procedure, and to determine the value of peripheral blood data for diagnosis. Pancytopenia was defined as the association of hemoglobin level below 12 g/dl in males and 11.5 g/dl in females, leukopenia below 4 x 10(9)/L, and thrombocytopenia below 150 x 10(9)/L. The bone marrow aspirates were normo- or hypercellular in 140 cases (66%). Bone marrow biopsies, performed in 93 cases, documented the presence of myelofibrosis in 67 cases. Aplastic anemia was diagnosed in 10% of the cases. Malignant myeloid disorders (acute myeloid leukemias, myelodysplastic syndromes, acute myeloid disorders with myelofibrosis) represented 42% of the cases and various malignant lymphoid disorders 18%. Vitamin deficiencies accounted for 7.5% and nonhematological pathology 10% of the cases. The bone marrow aspirate was sufficient for the diagnosis in 55% of the cases, and the trephine biopsy was necessary in 30%. In the remaining cases, other complementary tests were necessary to achieve final diagnosis. A discriminant analysis, focused on the hemogram data, showed that parameters obtained by analysis of blood smears were helpful for the diagnosis, especially the presence or absence of blast cells and/or of abnormal lymphoid cells.

Adolescent↗
PubMed1989

[Bioluminescence assay of luteinizing hormone in plasma and urine].

The authors describe a bioluminescent immunoassay of LH in plasma and urine. It uses two monoclonal antibodies, one is labelled with glucose-6-phosphate-dehydrogenase, the other one is coimmobilized together with bioluminescent enzymes from marine bacteria on the same adsorbent (Sepharose). This assay can be performed directly on 20 microliters plasma or 10 microliters urine. The protocol is very fast, no separation step is required to remove the excess labeled antibodies. The inhibitory effect of the biological sample on luminescent reaction is determined by adding NADH to the assay tubes. The working range of this assay is 3 to 300 Ul/l, with a sensitivity of detection of 0.5 Ul/l. Recovery, linearity, within and between assay precision were evaluated and appeared to be satisfactory. The authors have observed a good correlation between results obtained with our method and with radioimmunoassay.

Female↗
PubMed1988

Correlations between free plasma estradiol and estrogens determined by bioluminescence in saliva, plasma, and urine during spontaneous and FSH stimulated cycles in women.

Estrone and estradiol (E1 + E2) concentrations in saliva were compared with four other parameters of estrogen status in five normal ovulatory women and ten FSH stimulated women selected for an in vitro fertilization program. E1 + E2 in saliva, plasma, and urine were assessed by a rapid, specific and sensitive enzymatic assay using bioluminescence. The free fraction of plasma estradiol was determined by equilibrium dialysis and total plasma estradiol by conventional radioimmunoassay. The pattern of E1 + E2 variation in saliva was similar to that of free plasma estradiol and the two parameters were correlated in both spontaneous and stimulated cycles. However, the lower correlation coefficient (r = 0.52, P less than 0.001) in spontaneous cycles compared with the high (r = 0.96, P less than 0.001) in the stimulated cycles shows that salivary E1 + E2 could be representative of plasma free estradiol in stimulated cycles but not in normal cycles. The free fraction of plasma estradiol reproduced the variation of total plasma estradiol in spontaneous as well as in FSH stimulated cycles and both parameters were strongly correlated (r = 0.91, P less than 0.001 and r = 0.90, P less than 0.001), respectively. The data show that salivary E1 + E2 concentrations are highly representative of the free fraction of E2 in plasma and at a lesser extend (r = 0.72, P less than 0.001) of total plasma E2 in FSH stimulated cycles.

Adult↗