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J Grozdea

Publications and source records attributed to J Grozdea.

At least 19 recordsLinked to original sources

Lower alkaline phosphatase activity and occurrence of an abnormal hybrid intestinal/tissue non-specific isoform in Down's syndrome amniotic fluids.

Quantitative and qualitative analysis of alkaline phosphatases (AP) was performed on amniotic fluid in 59 normal pregnancies and 14 Down's syndrome (DS) pregnancies at 16, 18 and 19 weeks of gestation. In DS cases, intestinal and placental isoenzyme levels were significantly reduced (P<0.001) and the AP electrophoretic pattern was seen to be modified on polyacrylamide gel electrophoresis. A unique component was detected. After extraction and purification of the abnormal isoenzyme, peptide fragments obtained after cyanogen bromide cleavage indicated a hybrid heterodimeric AP composed of intestinal and tissue non-specific subunits, as evaluated by SDS polyacrylamide gel electrophoresis.

Adult↗

Atypical neutrophil alkaline phosphatase associated with impaired neutrophil functions.

We report the case of a healthy young man presenting with atypical neutrophil alkaline phosphatase (NAP) and reduced neutrophil chemotactic activity, but with no susceptibility to infection. NAP activity was low, kinetic parameters were modified and immunoreactive properties and subcellular distribution were abnormal. Neutrophil morphology was normal. A similar pattern was observed in the patient's healthy brother. The profile of the observed anomalies offers some similarity to that previously described in patients with chronic myelogenous leukaemia. However, in the present case, the NAP deficiency with impaired neutrophil function was present in two brothers with no haematological symptoms and is probably related to a non-acquired neutrophil abnormality. This observation of a primary NAP variant reinforces the hypothesis of a direct link between NAP activity and functional properties of neutrophils.

Adult↗

Evaluation of two markers of cell maturation and proliferation in cultured amniotic cells of trisomic 18 fetuses at the 15th week of gestation.

Intensive studies have been conducted so far on biochemical markers available for screening of chromosome defects in obstetrical monitoring. In this paper we report further data on two protein phosphatases: alkaline phosphatase (a marker of cell maturation) and phosphotyrosine phosphatase (a marker of cell proliferation) assayed in cultured amniotic cells from fetuses with trisomy 18 at 15 weeks of gestation. Comparison with normal fetal cells showed a different behaviour for each enzyme: alkaline phosphatase was very significantly lowered while phosphotyrosine phosphatase remained a normal levels. These results provide a further enlargement of the field of biochemical markers used in the screening tests of trisomy 18.

Alkaline Phosphatase↗

Changes in immunological properties of neutrophil alkaline phosphatase in trisomy 21 pregnancies.

Immunoreactivity, cytochemical, immunocytochemical characteristics and subcellular distribution of neutrophil alkaline phosphatase (NAP) were investigated in blood and/or smear samples from 18 women aged 23-46 years (mean 32.5 years) with trisomy 21 fetuses (17-21 weeks) and 28 women aged 20-42 years (mean 31 years) with normal fetuses (17-22 weeks). Immunochemical NAP investigations were carried out in 8 pathological and 8 normal pregnancies; cytochemical and immunocytochemical procedures were carried out in 18 pregnant women with trisomy 21 fetuses and 28 controls. NAP from women with trisomy 21 fetuses is characterized by: (1) a significant decrease in reactivity with anti-liver-type alkaline phosphatase (AP) and anti-NAP antisera; (2) low or very slight reactivity with antiplacental or anti-intestinal antibodies; (3) marked dispersion of NAP lead citrate reaction products or anti-NAP antibody colloidal gold-labelling in neutrophil cytoplasms, as detected by electron microscopy. This subcellular AP distribution (extramembranous) is different from that of normal NAP sites associated with plasma membrane, nuclear membrane and secretory vesicles. The NAP immunochemical and cytochemical characteristics suggest that neutrophils of a woman with a trisomy 21 fetus contain two AP isoenzymes: the liver/bone type and an atypical AP.

Adult↗

Phosphotyrosine phosphatase activity and haematologic changes in Down's syndrome patients.

Assays of neutrophil phosphotyrosine phosphatase activity and determination of haematological parameters were performed on 12 trisomic 21 probands without any clinical or biological symptom of other evolutive disease. Haematological studies showed the two main classical abnormalities: the existence of a macrocytosis and an enhanced lymphocyte count. Of interest are the very reduced rates of phosphotyrosine phosphatase activity found in granulocytes from these patients. This defect in protein phosphatase can be considered as an additional enzymatic change extending the list of modified factors recognized at molecular and cellular levels in subjects whose risk of leukaemia is significantly increased.

Adolescent↗

Alkaline phosphatase and phosphotyrosine phosphatase activities of cultured amniotic cells with trisomy 18.

In cultured amniotic cells from fetuses with Edward's syndrome (trisomy 18), the activities of two protein phosphatases, alkaline phosphatase and phosphotyrosine phosphatase, were measured. Comparison with normal fetal cells showed a different behavior for each enzyme. Alkaline phosphatase was significantly lowered while phosphotyrosine phosphatase remained at normal levels. The interest of these enzyme assays in the screening procedure of this severe chromosome defect is discussed.

Alkaline Phosphatase↗

Effects of uric acid in aqueous phase on neutrophil alkaline phosphatase.

In vitro effects of uric acid (2-6-8 trioxypurine) on purified human neutrophil alkaline phosphatase were studied. A marked activation of the enzyme catalyzed reaction is observed. This activation is dose and pH dependent and not influenced by dialysis. Uric acid can form a stable complex with alkaline phosphatase, whose biochemical characteristics (heat stability, reactivity towards some inhibitors) are significantly modified.

Adult↗

Difference in activity properties and subcellular distribution of neutrophil alkaline phosphatase between normal individuals and patients with trisomy 21.

Biochemical, cytochemical characteristics and electron microscopy subcellular distribution of neutrophil alkaline phosphatase (NAP) were analysed in blood and/or smear samples from 39 trisomy 21 patients (Down's syndrome) aged 11.5-18 years (mean 15.5 years) and 55 normal subjects aged 12-20.5 years (mean 17 years). All patients were karyotyped. NAP cytochemical procedures were carried out on all subjects; biochemical NAP determinations were made in 10 patients and 20 controls; ultrastructural electron microscopy of AP was performed in three patients and four normal subjects. Neutrophil alkaline phosphatase from patients with trisomy 21 displayed the following changes: (1) a significant increase of enzyme activity, (2) a high thermal lability of enzyme. Electron microscope morphology exhibited large deposits of NAP reaction product associated with the plasma membrane and intracellular main organelles, like phosphasomes. The NAP biochemical and cytochemical characteristics suggest that trisomy 21 neutrophils contain a non-specific AP isoenzyme, closely related to the early placental form.

Adolescent↗

New antibody in severe rhesus incompatible pregnancies: IgG-kappa antiplacental alkaline phosphatase.

As already found in other various diseases, a macromolecular alkaline phosphatase complex (HMW-AP) was also found in sera of two severe Rhesus-incompatible pregnancies complicated by ascites and fetal hydrops at delivery. This atypical complex was detected and isolated by agarose gel electrophoresis. Immunoelectrophoresis and heat inactivation of this HMW-AP complex revealed that it consisted of IgG of the kappa type and placental AP isoenzyme. The transitory presence of this immuncomplex is discussed. However, in all women with Rh-immunized complicated pregnancies, significant variations of neutrophil and serum AP activities were observed. A fall in AP activity and the presence of an antiplacental AP antibody in serum of women with complicated Rh immunization should be of value in assessing the prognosis of the disease.

Adult↗