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Biomedical subjects

G Schaison

Publications and source records attributed to G Schaison.

At least 127 records · Page 7Linked to original sources
PubMed1989

Pediatric bone marrow transplantation for leukemia and aplastic anemia. Report of 222 cases transplanted in a single center.

We report a single center experience of 222 patients (pts) less than 18 years old transplanted from 1973 to 1987. The median age was 11 years (1-18). The donor was a monozygotic twin (9 pts), an HLA-id sibling (193 pts), an HLA-id, parent (9 pts), a mismatched related donor (9 pts) and a matched unrelated donor (1 pt). Ninety-six pts were transplanted for SAA. Conditioning varied with time but the majority (59 pts) received CY 150 mg/kg and 6 Gy TAI. The long term actuarial survival is 66% with a median follow-up of 3 years. The group who received CY 200 mg/kg and MTX had a 33% long term survival (LTS). GVH was the main complication with 40% acute and 37% chronic GVHD. Chronic GVHD tended to improve with time after 2 to 4 years of evolution. Ninety pts were transplanted for leukemia (35 AML, 45 ALL and 11 CGL), 20 pts were in relapse. Pts in CR had a LTS of 40%, in pts in relapse, it was 12%. The main causes of death were: interstitial pneumonitis (30%), relapse (27%), GVH (15%). Thirty-five pts were transplanted for constitutional disease: Fanconi anemia (FA) (26 pts), Dyskeratosis congenita (2 pts), Blackfan-Diamond erythroblastopenia (2 pts), Glanzmann thrombasthenia (1 pt), osteopetrosis (1 pt) and Gaucher's disease (1 pt). In FA, the LTS is 70% with a CY 20 mg/kg, 5 Gy TAI regimen. In all disease categories, we did not find any influence of donor's sex on GVH and survival.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Castleman's disease: a well defined histological pattern for a widely divergent clinical spectrum.

If the histological patterns of Castleman's disease are well defined--hyaline vascular type and plasma cell type--, the clinical spectrum is widely divergent, ranging from localised forms cured by surgical ablation to multicentric idiopathic forms requiring systemic therapy; some cases are associated with an acquired immunodeficiency, such as HIV infection. The pathogeny of the disease is discussed.

Castleman Disease↗
PubMed1989

[Treatment of autoimmune hemolytic anemias in children].

Management of autoimmune hemolytic anemias (AIHA) in children is often difficult as some patients are very young and the course is often unpredictable. Corticosteroid therapy is the mainstay of the treatment of AIHAs. A dose of 2mg/kg/d should be given as early as possible. The return to normal of hemoglobin levels and reticulocyte counts are the two chief criteria of effectiveness. Only when both are present can disease remission be affirmed and corticosteroid therapy phased out over several months. Inadequate therapy of an acute form may promote prolongation of the disease. Prior to blood transfusion, the following tests should be performed: determination of ABO and Rh groups, determination of the erythrocyte phenotype whenever possible, identification of the specificity of the autoantibody, and investigations for an alloantibody. Splenectomy and immunosuppressive treatments are very rarely used and are indicated only in chronic forms of more than three months duration that fail to respond to high dose corticosteroid therapy or relapse as soon as doses are reduced. On the opposite, some forms are hyperacute and resolve very rapidly, with negativation of the often complement-type Coombs test; the course may be self-limited, especially if the autoantibody is a cold agglutinin or a biphasic hemolysin (Donath Landsteiner type), requiring no more than a few weeks of corticosteroid treatment.

Anemia, Hemolytic, Autoimmune↗
PubMed1989

[Antagonist and agonist effects of the antiprogesterone RU 486].

The mechanism of action of the antihormone substances, and more particularly of RU 486 antiprogesterone, is still poorly understood. The antagonist effect may take place at the receptor site while the latter is in its 8S inactive form. The antihormone blocks the heat shock protein 90 (HSP 90) and prevents the receptor from changing into its 4S active form, solely capable of binding the DNA-specific hormone responding element (HRE). However, if the antihormone does not impede receptor 4S activation, the antagonist effect may be explained by insufficient HRE affinity. Another possibility would be that the antihormone-4S receptor complex becomes chromatin-bound, although no bond is formed at the HRE-specific site. A certain affinity for HRE would explain the agonist effect of the antihormones. An affinity for DNA, outside HRE, would explain some specific activities peculiar to the antihormone. RU 486, which is both an antiprogesterone and an antiglucocorticoid substance, exhibits some powerful antagonistic characteristics. When neither progesterone nor cortisol is available, RU 486 displays weak agonistic effects. It can, therefore, serve as a good experimental model from which to study the mode of action of the antihormones.

Animals↗
PubMed1989

[Bilateral spontaneous pseudo-tumoral cytosteatonecrosis of the breast. Apropos of 2 cases in men].

Two uncommon cases of bilateral breast ischaemia in men are reported. Only one similar case has been published so far. Women, after pregnancy and delivery may also have fat necrosis of the breast, but it is also very unusual. Clinical symptoms are serious, and like tumours. The histological diagnosis is difficult to distinguishable from tissue changes due to self injected paraffin. However in those cases the X ray clearly shows pathognomonic signs of a paraffinoma. The physiopathology is still unclear. In our two cases we did not find any specific etiology. The main contributing factors are likely to be gynaecomastia and adipomastia complicated by lipo-glandular lysis caused by deep glandular ischemia.

Breast↗
PubMed1989

[Frequency and severity of systemic infections caused by Streptococcus mitis and sanguis II in neutropenic children].

We have retrospectively evaluated 24 sepsis episodes caused by viridans streptococci in 23 neutropenic children during a 21 months period at the Pediatric Hematology Unit of St. Louis Hospital. The underlying malignancies included acute lymphoblastic leukemia, acute non lymphoblastic leukemia, aplastic anemia and solid tumor. In 17 children neutropenia, defined as a neutrophil count of less than 500 per cubic millimeter, was caused by cytotoxic chemotherapy. For 6 other children neutropenia was consequential to pretransplant treatment regimen for autologous bone marrow transplantation including cytotoxic chemotherapy and total body irradiation. All patients had a silicone rubber atrial catheter. In 9 patients sepsis was associated only with fever for less than 48 hours. In 5 other children fever was prolonged more than 72 hours in spite of specific antimicrobial therapy. No other organism was isolated. In 10 patients, however, the infectious syndrome was severe and the features included cardiac failure (7 patients), pneumonia (7 patients) resembling adult respiratory distress syndrome, encephalopathy (3 patients) without meningitis and proteinuria, 7 of these patients needed a management in a pediatric intensive care unit and 2 died in spite of adapted antibiotics. Streptococci were isolated in blood cultures in 23 children.

Adolescent↗
PubMed1988

[Ceftazidime for the treatment of infections in neutropenic children].

Ceftazidime in doses of 100 mg/kg/day was used, combined with netilmicin 6 mg/kg/day, as first-line treatment in two successive studies conducted on febrile neutropenic children (neutrophils less than 500/mm3). Study n. 1, performed at the Infantile Haematology unit of Saint Louis hospital, Paris, included 75 children. Study n. 2 was a multicentre study involving 88 children from 11 medical centres. The children's age in both studies ranged from 2 months to 16 1/2 years (mean 7 years). The percentage of bacteriologically documented febrile episodes was 45 per cent (34/75 and 39/88), and the most frequent infections were those caused by Gram-positive cocci (56 and 58 per cent respectively of the cases). Vancomycin 40 mg/kg/day was introduced if fever was still present 48 hours after the beginning of the antibiotic therapy. Effective treatments were continued until the neutropenia was corrected. These children were being treated for acute leukaemia, lymphoma, solid tumours or bone marrow aplasia. In study n. 1 apyrexia was obtained in 85 per cent of the cases with the ceftazidime-netilmicin combination and in 91 per cent of the cases after addition of vancomycin. The initial therapy was effective in all patients with a documented infection. There were tow super-infections with septicaemia: one due to Streptococcus D, the other to Staph. epidermidis. In study n. 2 73 per cent of the patients were apyretic after the first combination and 85 per cent after vancomycin was introduced. In proven infections the ceftazidime-netilmicin combination was effective in 30 cases and in another 6 cases after addition of vancomycin. Three patients remained febrile until they came out of aplasia. In all cases the bacterial cultures were sterilized by the ceftazidime-netilmicin combination. There was no superinfection. The mean duration of antibiotic therapy was 21 days in study n. 1 and 14 days in study n. 2. The drugs were perfectly tolerated both clinically and biochemically. No death occurred in the two studies. Thus, owing to its broad spectrum, effectiveness and safety ceftazidime is a very useful antibiotic when combined with netilmicin as first-line treatment of febrile neutropenic children.

Adolescent↗
PubMed1988

[Probabilistic treatment with ceftazidime of infections in neutropenic patients].

Infection is the most common cause of mortality in neutropenic patients. Although fever does not necessarily mean infection, it must be regarded as its first sign and treated, within hours of its onset, on the basis of probability before a pathogen is isolated. The first-line treatment must cover a wide antibacterial spectrum corresponding to the usual bacteriological flora and to the patient's underlying pathology. The risk of Gram-negative septicaemia in infants and elderly people and the frequency of staphylococcal infections in patients with an indwelling central catheter are well-known. The "best guess" treatment should consist of a third generation cephalosporin, notably ceftazidime, and an antistaphylococcal antibiotic. This treatment should be pursued throughout the period of neutropenia. Due to advances in antibacterial therapy, more aggressive chemotherapeutic regimens can now be prescribed to improve the prognosis of acute blood diseases and of numerous carcinomas.

Agranulocytosis↗
PubMed1988

Cytogenetic study of 130 childhood acute nonlymphocytic leukemias.

Cytogenetic studies performed on 130 consecutive childhood acute nonlymphocytic leukemias (ANLL) investigated in the same center between 1977 and 1986 are reported. The incidence of clonal chromosomal abnormalities was 68.5% with uneven distribution among the groups of the FAB nomenclature. The high incidence of t(8;21) translocation cases, which was 58.6% of M2 ANLL cases, was remarkable. Complete remission rate was lower (P less than 0.05) in ANLL with all karyotypically abnormal metaphases (AA) than in the other ANLL (NN, with only normal metaphases, and AN, with a mixture of normal and abnormal metaphases). Median survival was also shorter in AA ANLL than in AN and NN cases (P less than 0.01). Median survival was different according to karyotype abnormalities: 11q anomalies and t(15;17) were not associated with a good prognosis, and the t(8;21) is not associated with a particularly long median survival (16 months) when compared with other ANLL as opposed to the results of others. The longest survival (26 months) was observed in patients with acute myelomonocytic leukemia with bone marrow eosinophilia. It may be concluded that chromosome studies have a prognostic value in childhood ANLL.

Bone Marrow Examination↗
PubMed1988

Pathophysiology of anovulation.

Anovulatory disorders are physiological during puberty, postpartum period and just before the menopause. In pathology, they are one of the earliest symptoms of different diseases: functional or organic hypothalamic diseases, pituitary destruction or inappropriate feedback by the peripheral hormones and, obviously, primary ovarian insufficiency. Their real interest lies in their pathophysiology. Functional hypothalamic disorders are defined as the inability to liberate GnRH in a physiological way. The role of endogenous opioids, as essential factors of gonadotrophin regulation will be discussed. Hyperprolactinaemias, which represent 20% of the anovulations, have an antigonadotrophic effect at the hypothalamic level, but the very mechanism of the inhibitory effect of prolactin on GnRH is still open to discussion. Although polycystic ovarian disease is one of the most common endocrine abnormalities in women, its pathophysiology remains far from fully understood. The relative parts played by hypothalamic disturbances and by abnormal feedback of gonadal steroids will be discussed.

Anovulation↗
PubMed1988

Leydig cell insufficiency after testicular irradiation for acute lymphoblastic leukemia.

Leydig cell function in 21 boys with acute lymphoblastic leukemia who had been treated by bilateral direct testicular irradiation (12 X 2 Gy) at 8.4 +/- 0.7 years, was evaluated 3.8 +/- 0.4 years after irradiation. At the time of irradiation all were prepubertal and at evaluation 12 were prepubertal and 9 pubertal. Leydig cell insufficiency, indicated by a low plasma testosterone response to chorionic gonadotrophin and/or an increase in basal level of plasma luteinizing hormone, was observed in 19/21 patients. The children who were the youngest at testicular irradiation were more vulnerable. Spontaneous virilization occurred in 3 of the older children and resulted from compensated Leydig cell dysfunction.

Adolescent↗
PubMed1988

The antiglucocorticoid and antiprogestin steroid RU 486 suppresses the adrenocorticotropin response to ovine corticotropin releasing hormone in man.

The glucocorticoid and progesterone antagonist RU 486 normalizes the clinical and biochemical features of hypercortisolism in patients with nonpituitary Cushing's syndrome, presumably by antagonizing the action(s) of cortisol. Since RU 486 has progesterone agonist activity in addition to its progesterone antagonist action, the possibility that it might have some glucocorticoid agonist action did not seem unreasonable. To test this hypothesis we examined the effects of RU 486 on pituitary ACTH secretion in 10 patients with primary adrenal insufficiency in whom glucocorticoid replacement was withheld for 36 h. Each patient received, in randomized sequence 3-7 days apart, an oral dose of placebo, RU 486 (20 mg/kg), cortisol (0.1 mg/kg), or a combination of RU 486 and cortisol at 1800 h. Two hours later, an iv bolus dose of ovine CRH (1 microgram/kg) was administered, and plasma ACTH levels were measured serially for 3 h. RU 486 suppressed ovine CRH-stimulated ACTH secretion, albeit less than cortisol. Its glucocorticoid agonist effect was calculated to be approximately 1/250th that of cortisol on a weight basis. Additionally, RU 486 partially antagonized cortisol-induced suppression of ACTH secretion. These findings suggest that RU 486 is a partial glucocorticoid agonist and offer some insight as to its action in patients with Cushing's syndrome. Whether this degree of glucocorticoid agonist activity is adequate to support life, however, is not known.

Addison Disease↗
PubMed1988

Stimulation of ovarian follicular maturation with pure follicle-stimulating hormone in women with gonadotropin deficiency.

According to the 2-cell theory, ovarian steroidogenesis requires the coordinate action of both FSH and LH. To evaluate the relative importance of these hormones in follicular maturation, a randomized cross-over study was performed in 10 women with complete gonadotropin deficiency (absence of pulsatile LH secretion and no LH response to LHRH). Five women were treated with highly purified FSH (LH bioactivity, 0.09%) and 3 months later with human menopausal gonadotropin (hMG; LH bioactivity, 65%), each given for 10 days at a daily dose of 225 IU FSH, im. The sequence was reversed in the other 5 women. hCG (5000 IU) was administered im 24 h after the last injection of FSH or hMG. Plasma estradiol (E2), estrone (E1), androstenedione (A), testosterone, LH, and FSH concentrations and urinary LH and FSH were measured daily by RIA. Ultrasonography was performed during each treatment and 2 days after each hCG injection. After FSH treatment, mean plasma and urinary FSH levels increased, mean plasma LH did not change, and urinary LH increased slightly but not significantly from 91 +/- 32 (SE) to 164 +/- 55 mIU/24 h (10(-3) IU/24 h). After hMG treatment, mean plasma and urinary LH and FSH levels increased accordingly. The mean basal plasma E2 [11 +/- 1 pg/mL (40 +/- 4 pmol/L)] and E1 [14 +/- 4 pg/mL (52 +/- 15 pmol/L)] levels increased after FSH treatment to 207 +/- 69 pg/mL (760 +/- 253 pmol/L) and 82 +/- 21 pg/mL (303 +/- 78 pmol/L), respectively (P less than 0.01), but plasma A did not change. In response to hMG, the mean plasma E2, E1, A, and testosterone levels increased more than during FSH treatment. Ultrasonography revealed multiple preovulatory follicles (greater than or equal to 16 mm) in 2 women after hMG and 1 woman after FSH treatment; therefore, hCG was not administered. In 3 women given FSH, hCG did not induce ovulation. hCG induced ovulation in 8 women given hMG and in 6 women given FSH, based on ultrasonography and plasma progesterone levels. Thus, in the presence of profound gonadotropin deficiency pharmacological doses of FSH, with minute LH contamination, are capable of stimulating ovarian follicular maturation, underlining the key role of FSH in folliculogenesis.

Adolescent↗
PubMed1988

Use of immunocytochemistry of progesterone and estrogen receptors for endometrial dating.

Endometrial progesterone and estrogen receptors were studied by immunocytochemistry using monoclonal antibodies during the menstrual cycle in normal women. We initially compared immunocytochemical staining of progesterone and estradiol receptors on endometrial fragments obtained by either aspiration or endometrial biopsy and found that immunocytochemistry could be performed easily on tissue obtained in either way. The immunocytochemical studies showed that the concentration and distribution of receptors changed markedly during the normal menstrual cycle. These changes were distributed in three characteristic phases. During phase I, corresponding to the midfollicular period (days 7-8), a small proportion (25%) of stromal and glandular cells stained positively for the progesterone receptor, whereas estrogen receptor staining was more intense and more frequent (50% of cells). Phase II, which included both the late follicular and early luteal periods (days 9-19), was characterized by a marked staining of progesterone receptors in the majority of glandular cells (75%) and somewhat less abundant and less frequent staining in stromal cells (50%). Estrogen receptor staining was present in about half of the glandular and stromal cells. Phase III, the mid- and late luteal period (days 21-27), was characterized by the disappearance of estrogen and progesterone receptor staining in glandular cells, although faint staining for both receptors was found in stromal cells. These variations in progesterone receptor staining are potentially useful for determining the effect of progesterone on endometrial maturation.

Biopsy↗