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Biomedical subjects

R Mariani

Publications and source records attributed to R Mariani.

At least 37 records · Page 2Linked to original sources
PubMed1996

Increased urinary catecholamines in a hypertensive child with renal artery stenosis.

We report a hypertensive child with renal artery stenosis who exhibited increased urinary excretion of norepinephrine (NE) and normetanephrine (NMN), while vanillylmandelic acid (VMA) excretion was within the normal range. The NMN values prompted us to investigate the patient for pheochromocytoma; for this purpose, NE was determined by plasma catecholamine assays in venous samples obtained by catheterization. The moderately increased NE levels could not be localized to any particular sampling site. Arteriography demonstrated right renal artery abnormalities. Following right nephrectomy with preservation of the right adrenal gland, arterial blood pressure returned to normal. The cause of increased NMN excretion without a concomitant rise in VMA during hypertension is discussed.

Angiography↗
PubMed1996

[Post-traumatic hypopituitarism after skull injury: apropos of 3 cases].

BACKGROUND: Hypopituitarism is a rare but well-known complication of cranial trauma. In the absence of overt diabetes insipidus, its recognition is difficult as the onset of clinical symptoms can be very progressive, up to several years. CASE REPORTS: Three children, aged 8, 9 and 2 years, respectively, were admitted after a cranial trauma. Manifestations of diabetes insipidus occurred a few days later in two patients; one of them developed secondary growth hormone deficiency, hypothyroidism and hypogonadism, only evidenced at the age of 14 years. The third patient also developed manifestations of hypothalamic and/or pituitary hormone deficiencies without diabetes insipidus at the age of 12 years-6 months. MRI showed complete severance of the pituitary stalk in two patients and absence of posterior pituitary signal in one of the two patients with diabetes insipidus. CONCLUSION: Growth disorders and/or hypogonadism may occur many years after a trauma that may have been forgetten. Search for such an etiology and dynamic MRI are necessary in identifying heterogenous hypophyseal lesions.

Child↗
PubMed1996

[Treatment of neonatal hyperthyroidism with calcium iopodate].

BACKGROUND: Treatment of hyperthyroidism in those neonates born to mothers with Grave's disease is difficult. Calcium ipodate, an agent for oral cholecystography, inhibits extra-thyroid conversion of T3 to T4 and diminishes thyroid secretion. CASE REPORTS: Two neonates with clinical manifestations and biological findings of hyperthyroidism were given calcium ipodate orally, 400 mg every 3 days, from day 26 to 50 for the first patient and from day 9 to 18 for the second in association with a beta blocker. Clinical manifestations disappeared within 2 days and circulating levels of T3 and T4 were normalized within 2-5 days. CONCLUSIONS: This treatment was effective and well-tolerated in both patients and in three others previously reported; it should be confirmed in a larger number of patients and controlled by measuring levels of antibodies directed against thyrotropin-releasing hormone receptors in order to avoid relapse after cessation of treatment as seen in our second patient.

Adrenergic beta-Antagonists↗
PubMed1996

Three years of GH treatment in Turner's syndrome: complex effect of GH dosage on growth parameters. French Pediatric Clinics and Sanofi-Winthrop.

OBJECTIVE: There have been few studies of GH dose responses in Turner's syndrome. We have therefore compared the growth effect of two doses of subcutaneous GH: 0.45 (D1) or 0.90 (D2) IU/kg/week. DESIGN: Multicentre study with two parallel randomized groups treated with D1 or D2 dose for one year, then with D2 for the second and third years in both groups. PATIENTS: Ninety-seven girls with Turner's syndrome aged from 4.8 to 16.5 years. RESULTS: The first mean height velocity (HV) was significantly higher with D2. At one year the girls changed from D1 to D2 showed a further acceleration in HV. During second and third years HV remained above the mean for untreated Turner girls, in both groups. Mean cumulative height gains over the 3 years were 1.06 and 1.17 SDS/CA (Ranke's Turner standard) in groups G1 and G2 respectively. Bone maturation, over 36 months, was 33.7 (G1) and 31.9 (G2) months. CONCLUSION: These results suggest that, if a higher initial GH dose is associated with a greater net initial height gain, the duration of treatment might affect the long-term results. Intermittent treatment should be considered.

Adolescent↗
PubMed1996

High frequency of defective nef alleles in a long-term survivor with nonprogressive human immunodeficiency virus type 1 infection.

A large number of nef alleles were obtained from peripheral blood mononuclear cells (PBMC) of four long-term nonprogressing survivors of human immunodeficiency virus type 1 (HIV-1) infection and from five individuals with progressive HIV-1 infection. These primary nef alleles were characterized by DNA sequence analysis and for their ability to downregulate CD4 surface expression. Intact nef open reading frames that directed the expression of Nef protein were recovered from all of the individuals. Most of the Nef proteins derived from three of four individuals with nonprogressive infection and from all five individuals with progressive infection were functional as judged by their ability to induce a decrease in surface CD4 expression. In contrast, one individual with nonprogressive HIV-1 infection yielded an unusually high frequency of disrupted nef open reading frames and Nef proteins defective for CD4 downregulation. Approximately 70% of the nef clones obtained from the PBMC of this individual at eight time points over a 12-year period were disrupted or defective for CD4 downregulation. While functional Nef proteins were demonstrated early in the course of infection (1983), functional nef alleles have surprisingly not come to predominate over time in PBMC DNA in this individual.

Alleles↗
PubMed1996

[Non-specific tuberculin reactivity due to sensitization to non-tuberculous mycobacteria (NTM) in children not vaccinated with BCG. Diagnostic value of a comparison of intradermal tests with tuberculin and NTM antigens].

Sensitisation to non tuberculous mycobacteria (NTM) may provoke a non specific tuberculin reaction and can cause problems in the interpretation of tuberculin tests in subjects who have not been vaccinated with BCG. The practice of testing for antigens to NTM (sensitins) should be useful for pointing to the right diagnosis. Our study was carried out on 24 asymptomatic children aged between 11 months and 8 years 9 months; these children were considered to be sensitive to NTM based on comparative cutaneous tests (reactions to sensitins > or = 5 mm and > or = 3 mm vs tuberculin) and were selected from a group of 53 children who had either initially achieved a positive tuberculin reaction or who had undergone conversion on subsequent prevaccination testing. The tests were carried out with tuberculin RT 23, tuberculin Merieux and sensitins from M. avium and M. intracellulare. They had been repeated two to four months later in cases of a response to one of the different reactants. At the first examination the tuberculin reactions were most often weak, the Merieux tuberculin induced a stronger response than the RT23 tuberculin. A dominant response for one or both sensitins was present in 18 cases. The tuberculin reactions became weaker whilst the sensitins remained relatively stable. The difference became significant in the six remaining cases. Although tests for tuberculin and sensitins have some diagnostic value which is necessarily imprecise, comparative analysis of the cutaneous reactions to the different antigens may contribute to avoid an erroneous interpretation for tuberculin allergy in asymptomatic young children without any risk factors for tuberculous infection. It is important to identify those subjects having non specific tuberculin reactivity induced by sensitisation to NTM in order to avoid non justified chemoprophylaxis and also to be able to vaccinate these children with BCG.

Antigens↗
PubMed1995

Human immunodeficiency virus type 1 Nef and p56lck protein-tyrosine kinase interact with a common element in CD4 cytoplasmic tail.

The human immunodeficiency virus type 1 nef gene induces endocytosis of CD4 antigen and disrupts the association between CD4 and p56lck protein-tyrosine kinase (EC 2.7.1.112). We demonstrate that in T cells these effects of the viral protein require a cluster of hydrophobic amino acids in a membrane-proximal region of the CD4 cytoplasmic tail; other amino acids in the C-terminal segment of CD4 cytoplasmic tail also contribute to the interaction. Mutations in CD4 that prevent down-modulation by Nef also decrease CD4 association with p56lck and prevent Nef-induced disruption of CD4-p56lck complexes. Together, the overlap in CD4 sequences required for interaction with Nef and p56lck and the tight correlation between Nef-induced CD4 down-modulation and disruption of CD4-p56lck association suggest that Nef, or cellular factors recruited by Nef, interact with this segment of CD4 to displace p56lck from the complex and induce CD4 endocytosis.

Amino Acid Sequence↗
PubMed1995

Abnormal alpha-aminoadipic acid excretion in a newborn with a defect in platelet aggregation and antenatal cerebral haemorrhage.

alpha-Aminoadipic acid (alpha AA) is an intermediate in lysine metabolism. We report a new case with alpha AA excess in urine and plasma, without alpha-ketoadipic acid, in a full-term male child born to unrelated parents; he presented at 24h of life with seizures that failed to respond to phenobarbital, clonazepam, and Vigabatrin and death occurred on the 38th day of life. Brain imaging suggested antenatal haemorrhage. Small quantities of alpha AA were also detected in the blood and urine of both parents and a healthy brother, all three of whom exhibited the same defect in platelet aggregation as the deceased child. Both parents had decreased levels of plasma neopterin, a finding that might be related to the immunodeficiency described in other cases.

2-Aminoadipic Acid↗
PubMed1995

[Maternal-fetal transmission of HIV].

HIV infection in children is mainly the result of a mother-to-child transmission. The contamination during pregnancy is well known but intrapartum vertical transmission may also occur through ascending infection, blood exchange between mother and child, or direct contact with vaginal or cervical secretions. In addition HIV can be transmitted via breast milk. The reported rates of vertical transmission are highly variable: 14.4% in a European study, 18.3% in a French survey, 20 to 25% in the USA, 35 to 50% in Africa. It is unclear whether such a large variation of the rate of transmission is due to methodological differences or to different distributions of risk factors in the populations. There are some known predictive factors of HIV transmission such as low CD4 cells count, positive p24 antigenaemia and elevated concentrations of virus. The role of other factors is still debated: prematurity, virus (CMV, HTLV-1, HVB, HVC), C section prior labour, rupture of membranes. The prevention of HIV infection in infants is mainly based on contra-indication of pregnancy in infected women, desinfection of the vagina at the beginning of labour, early protection of the newborn by avoiding skin lesions and immediate washing, preventive treatment by zidovudin during pregnancy.

Female↗
PubMed1995

Defective accessory genes in a human immunodeficiency virus type 1-infected long-term survivor lacking recoverable virus.

We have been studying a patient who acquired human immunodeficiency virus (HIV) infection via a blood transfusion 13 years ago. She has remained asymptomatic since that time. The blood donor and two other recipients have all died of AIDS. Although this patient has shown persistently strong seroreactivity to HIV type 1 (HIV-1) antigens by Western blot (immunoblot), she has been continually HIV culture negative in results from multiple laboratories over the last 6 years and has a very low viral burden. Her CD4+ T-cell count has fluctuated around a mean of 399 cells per microliters, with little change in lymphocyte subset percentages. Strong cellular immune responses to HIV-1 epitopes by this patient have been demonstrated. We now report the results of an intensive molecular genetic analysis of the HIV-1 proviral quasispecies from this patient sampled over 5 years. Long terminal repeat region sequences supported the argument for normal basal and Tat-mediated promoter activities. Sequential sequencing of the nef gene revealed a low frequency (8.3%) of defective genes and a striking lack of sequence evolution. Functional analysis of predominant nef genes by both a cell surface CD4 downregulation and a viral infectivity complementation assay showed wild-type function. In contrast, sequential analysis of an amplicon containing the vif, vpr, vpu, tat1, and rev1 genes revealed the presence of inactivating mutations in 64% of the clones. These data suggest that this patient, initially infected with a virulent swarm of HIV-1, is presently infected with a more-attenuated viral quasispecies as a result of effective host immunity.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Nephrocalcinosis and prematurity: importance of urate and oxalate excretion.

Nephrocalcinosis was described in preterm infants by several authors who tried to determine its association with hypercalciuria and furosemide therapy. We evaluated these potential mechanisms along with other lithogenic factors not previously studied in 10 premature babies. Hypercalciuria was an inconsistent finding like in other reports; elevated uric acid excretion and hyperoxaluria were observed in 5 and 6 cases, respectively. The aminocid excretion was normal in all infants. Our data suggest that in addition to hypercalciuria, other lithogenic factors may play a role in the pathophysiology of nephrocalcinosis of premature infants.

Glycosuria↗
PubMed1994

Altered glycosylation of leukosialin, CD43, in HIV-1-infected cells of the CEM line.

CD43 (leukosialin, gpL115, sialophorin) is a major sialoglycoprotein widely expressed on hematopoietic cells that is defective in the congenital immunodeficiency Wiskott-Aldrich syndrome. It is thought to play an important role in cell-cell interactions and to be a costimulatory molecule for T lymphocyte activation. Using a metabolic 35SO4(2-) radiolabeling assay or biotinylation of cell surface proteins, we describe here that CD43 are sulfated molecules the glycosylation of which is altered in human immunodeficiency virus type 1 (HIV-1)-infected leukemic T cells of the CEM line. Hyposialylation of O-glycans and changed substitution on N-acetylgalactosamine residues are observed. The glycosylation defect is associated with an impairment of CD43-mediated homotypic aggregation which can be restored by resialylation. The hyposialylation of CD43 on HIV-1+ cells may explain the high prevalence of autoantibodies directed against nonsialylated CD43 that have been detected in HIV-1-infected individuals. A defect in glycosylation of important molecules such as CD43 or, as we recently described, CD45 may explain alterations of T cell functions and viability in HIV-1-infected individuals. In addition, a possible implication of hyposialylation in the HIV-1-infected cells entrapment in lymph nodes could be envisioned.

Antibodies, Monoclonal↗
PubMed1994

Study of final height in Turner's syndrome: ethnic and genetic influences.

In understanding Turner's syndrome, spontaneous adult height is a prerequisite for an accurate assessment of the therapeutic efficiency of growth hormone treatment. The heights described in the literature reveal significant differences (136-147 cm). Our collaborative study pooled results from 16 pediatric endocrinology centers and obtained a large number of spontaneous adult heights (n = 216). The selective criteria were: chronological age (CA) > 18 years, bone age (BA) > 16 years, typical karyotype, no treatment with growth hormone or anabolic steroids. Mean CA was 23.3 +/- 5.6 years. Chromosomal anomalies were: monosomy X 56%; mosaicism 37.2%; structural aberration 10.6%. Mean final height in the whole group was 141.5 (129-160) cm. There was no significant difference in height between the three groups: monosomy X (n = 121: 141.1 +/- 6.4 cm); mosaicism (n = 72: 141.5 +/- 7.5 cm); X anomaly (n = 23: 141.4 +/- 5.0 cm). Mean parental height was 170.4 +/- 7.1 cm (father) and 160.1 +/- 6.2 cm (mother). Parental height and patients' heights correlated significantly, but more so with fathers' heights (r = 0.50) than with mothers' (r = 0.42). The correlation was still apparent with the target height (r = 0.55). The results of different series in the literature show the existence of significant variations as mean final heights are between 136 and 147 cm. These differences can be explained by the variations in normal female heights in each country. We have found in these different countries a very strong correlation (r = 0.91) between normal height and final height in Turner's syndrome.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗