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M Wajner

Publications and source records attributed to M Wajner.

105 records · Page 6Linked to original sources
PubMed1989

Inborn errors of metabolism. Sensitivity of screening tests in high risk patients.

We estimated the sensitivity of a screening procedure (SP) for inborn errors of metabolism (IEM) in 566 referred, high-risk patients. The 143 (25.3% of the total sample) patients with initial abnormal results in at least one screening test (ST) were recalled for further investigations. An IEM was diagnosed in 40.6 percent of the 106 patients who came for reevaluation. In 114 of the remaining 423 patients who had normal initial ST, an IEM was still suspected on basis of clinical, radiological, and/or laboratory findings and was confirmed in 30 of such patients (5.3% of the total sample and 7.1% of the patients with normal results in the SP). The sensitivity of the SP was estimated maximally as 67.4 percent and the efficiency as 80.4 percent. Twenty-five of the 30 cases undetected with the SP were patients with sphingolipidoses. The simple inclusion of thin-layer chromatography of urinary oligosaccharides in the SP should allow the detection of at least one half of these cases, increasing its sensitivity by 14.1 percent and its efficiency by 4.6 percent. In at least 7.1 percent of patients with an initial normal ST, an IEM was detected. These would have remained undiagnosed if the limitations of the SP employed had not been fully understood.

Child↗
PubMed1988

Diminished concentrations of ganglioside N-acetylneuraminic acid (G-NeuAc) in cerebellum of young rats receiving chronic administration of methylmalonic acid.

Sustained levels of methylmalonate comparable to those of human methylmalonic acidemia were achieved in the blood of young rats from the 5th till the 25th day of life by injecting them subcutaneously with buffered methylmalonic acid (MMA) twice a day at 8-h intervals. A matched group of rats (controls) was treated with saline. The animals were weighed and killed by decapitation at 25 days of age. Cerebellum and cerebrum were weighed and their contents of protein, DNA and ganglioside N-acetylneuraminic acid (G-NeuAc), as well as the protein/DNA ratio determined. Body weight, cerebral and cerebellar weight did not differ in both groups. The concentrations of protein, DNA and the protein/DNA ratio were also similar in the experimental and control groups. The results indicate that MMA per se does not interfere with the appetite of the animals and does not affect cellular proliferation and growth in cerebrum and cerebellum. We also found that G-NeuAc concentration is significantly reduced in the cerebellum. Therefore, since a deficit of an important component of brain closely related to the dendritic surface (synaptogenesis) occurs in MMA-treated rats, it is tempting to speculate whether this alteration may be associated or even partly responsible for the mental retardation in patients affected by methylmalonic acidemia.

Animals↗
PubMed1987

Relationship between serum immunoglobulin G and alpha-fetoprotein levels during human pregnancy.

The immunoregulatory processes operating during pregnancy that allow the survival of the semiallogeneic conceptus are at present far from understood. alpha-fetoprotein (AFP) is a biological component of the body produced in high amounts during pregnancy mainly by the fetal liver, and in certain clinical pathological states. The biological function of AFP is still unknown, but some investigators postulate an immunosuppressive role for the protein during pregnancy. In this study, serum immunoglobulin G, M and A levels of 101 gravidas at different stages of gestation (26 from 11-14 weeks, 37 from 32-34 weeks and finally 38 from 38-40 weeks) were determined and compared to 57 age matched nonpregnant females. Before being included in the study, patients were checked for various conditions which potentially alter immunoglobulin and AFP serum levels. Maternal serum samples showed a significant decreased concentration of immunoglobulin G (IgG) as compared to non-pregnancy serum samples (table I). AFP levels were also quantitated in the pregnancy sera and correlated with immunoglobulins levels. A strongly negative correlation between AFP and IgG was found throughout gestation (table II). When gestational age was fixed and the partial coefficients of correlation calculated, the inverse correlation persisted. In addition, the relationship between AFP and IgG at the various periods of gestation (11-14 weeks, 32-34 weeks and 38-40 weeks), calculated in order to detect where the association was stronger, revealed significant and uniform negative correlations (table III).(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗
PubMed1987

Detection of inborn errors of metabolism in unselected patients from pediatric intensive care units in Porto Alegre, Brazil: evaluation of screening techniques.

1. The present study provides an analysis of the interpretation and usefulness of mass biochemical urine screening tests currently applied to a population of severely ill children consisting of 232 unselected individuals, under various medications, held in intensive care units. 2. Testing for glycosaminoglycans by the cetyltrimethylammonium bromide reaction is of little benefit to this population. The Ehrlich reaction, used to detect porphobilinogen, should be reserved for cases which present clinical symptoms. Owing to the large number of false-positives and because chromatography or electrophoresis can easily be used to detect tyrosine, it is suggested that the nitrosonaphthol test be abandoned. The cyanide nitroprusside reaction should be used when chromatography or electrophoresis suggests cystinuria, homocystinuria or beta-mercapto lactate disulfiduria. 3. Because of its high sensitivity in detecting reducing substances, the Clinitest is useful for selecting samples to be investigated further by sugar chromatography. 4. Given the relatively high frequency of organic acidurias, particularly methylmalonic aciduria, in intensive care unit populations, it is suggested that the p-nitroaniline reaction be incorporated into the battery of chemical urine tests. 5. A comparison between paper chromatography and high voltage paper electrophoresis in terms of effective analysis of amino acid patterns demonstrated that chromatography is preferential, since this is as sensitive as electrophoresis, does not require a special apparatus and permits the simultaneous use of plasma and urine from the same patient, thus facilitating the interpretation of amino acid patterns.

Amino Acid Metabolism, Inborn Errors↗
PubMed1986

Inhibition of mitogen and allogeneic stimulated lymphocyte growth by human amniotic fluid: lack of correlation between alpha-fetoprotein level and in vitro immunosuppression.

The influence of human amniotic fluid from women at 16-18 wk gestation on the in vitro proliferation of human peripheral lymphocytes stimulated with various mitogens (PHA, Con A and PWM) and with allogeneic cells in the one- and two-way mixed lymphocyte reaction (MLR) was studied. It was seen that amniotic fluid inhibits nonspecifically the responsiveness of the various subpopulations of cells induced to proliferate. It was also demonstrated that the suppression depends on the concentration of the immunosuppressive agent(s), since diluted amniotic fluids showed less inhibitory capacity. In order to detect a possible immune action for alpha-fetoprotein (AFP), the levels of the protein in the amniotic fluid supplemented cultures were correlated with the inhibitory properties of the fluids. No correlation was encountered, indicating that AFP is not mainly responsible for the in vitro immunosuppressive properties of human amniotic fluid on the in vitro test of cell-mediated immunity here utilized.

Amniotic Fluid↗
PubMed1986

Relationship between some obstetric landmarks and the concentration of alpha-fetoprotein in maternal blood.

Alpha-fetoprotein (AFP) quantitation in maternal blood has been used for prenatal diagnosis of anencephaly, spina bifida and some other congenital abnormalities. The levels of AFP in pregnancy serum are greatly dispersed within each gestational period, what makes the test of difficult interpretation mainly in border line cases. The factors which contribute to this variability are still poorly understood. They must act either on the synthesis or catabolism of the protein, or on the permeability of the fetal-maternal barrier. In an attempt to elucidate some of these factors, the levels of AFP in serum of 89 women at 32 to 34 weeks gestation and of 115 women at term were measured by radioimmunoassay and related to several obstetric variables such as parity, pregnancy number, 1 - minute Apgar score, smoking habit and sex of newborn. It was seen that parity and pregnancy number do not correlate with the levels of AFP in pregnancy serum. Smokers, particularly those who smoke more than a pack per day, however, had higher levels of the protein in their blood. The interpretation of these data should take into consideration the fact that smoking causes vasoconstriction and important vascular alterations similar to the ones encountered in diabetic angiopathy. It is possible that an increased microvascular permeability of placenta and/or membranes to proteins of the size of AFP from the fetus to maternal circulation may explain the greater levels of the protein in serum of smokers.(ABSTRACT TRUNCATED AT 250 WORDS)

Apgar Score↗
PubMed1985

Inhibition of phytohaemagglutinin-induced lymphocyte blastogenesis by serum from pregnant women: correlation between cortisol level and in vitro immunosuppression.

Peripheral human blood lymphocytes stimulated by optimal doses of phytohaemagglutinin (PHA) were cultured in the presence of serum obtained from non-pregnant (controls) and pregnant women at different stages of gestation. A significant inhibitory influence on cellular growth was identified in the serum from pregnant women from the second trimester onward but more pronounced at the end of gestation. This inhibition was strongly correlated with the levels of cortisol in the sera. The action of commercial cortisol on lymphocyte reactivity in cultures stimulated by various concentrations of PHA and containing either a pool of pregnancy sera, or a pool of non-pregnancy sera, or a mixture of these pools was also investigated. The hormone provoked a significant inhibition more evident when low doses of PHA were used. The same finding occurred with the gravida's sera pool supplemented cultures.

Adult↗
PubMed1984

Tay-Sachs disease heterozygote detection in Brazil: comparison between tears and leukocytes as beta-hexosaminidase A source.

Hexosaminidase A activities were determined in tears and peripheral leukocytes of carriers and noncarriers for Tay-Sachs Disease (TSD) as a percentage of total hexosaminidase activity. Correlation between enzyme activities in tears and leukocytes was highly significant (r = 0.75, p less than 0.01). Compared to leukocytes, screening in tears revealed 100% sensitivity, 100% negative predictive value, 86% specificity and 80% positive predictive value. These results indicate that tears are a satisfactory material for mass-screening of TSD-carrier state, but positive results must be confirmed in peripheral leukocytes. Seven heterozygotes were detected among 298 young Ashkenazi Jewish volunteers screened, giving an adjusted frequency of the TSD gene of 0.024.

Adult↗
PubMed1984

Clinical and biochemical effects of long-term vitamin A administration to a patient with Hurler-Scheie compound.

Vitamin A decreased the urinary excretion of total mucopolysaccharides in a patient with Hurler-Scheie compound (type IH-S mucopolysaccharidosis). Vitamin A was administered orally in daily doses of 1,000 to 2,000 IU/kg body weight for 10 years. Adverse clinical responses such as irritability, bone pain, dizziness, vomiting and diarrhea appeared in the patient and were controlled by reduction of the dose administered. No clinical improvement was observed, although it is possible that the clinical course of the disease may have been retarded.

Adolescent↗
PubMed1983

Inhibition of lymphocyte transformation by serum from pregnant women: lack of correlation with levels of alpha-fetoprotein.

Lymphocytes from pregnant and non-pregnant women were stimulated with optimal doses of phytohaemagglutinin (PHA) in order to detect any possible suppression of the maternal cellular immune capabilities. No major differences were observed. Similar cultures using lymphocytes from normal healthy individuals were exposed to sera from pregnant and non-pregnant women. A consistent inhibitory influence, more pronounced at the end of gestation, was identified in the sera from pregnant women. No correlation was found between the levels of alpha-fetoprotein in the pregnant sera and the degree of inhibition observed in the cultures.

Female↗
PubMed1983

Response of human peripheral blood lymphocytes in the presence of cord sera: relationship of lymphocyte transformation with number of pregnancies and levels of alpha-fetoprotein.

Peripheral blood lymphocytes were stimulated with various mitogens (PHA, Con A and PWM) and allogenic cells in the presence of cord serum. The cord sera suppressed more effectively certain T cell populations. This immunoregulatory response of cord serum was compared with nonpregnant and pregnant sera from different gestations. Although the cord sera showed significantly higher inhibition compared to normal adult serum but the serum from gravidae in late gestation proved more inhibitory compared to cord serum. No correlation was found between the levels of alpha-fetoprotein (AFP) in the cord sera and the degree of inhibition observed in the cultures. As previously described for pregnant sera the cord serum obtained from women with different numbers of pregnancies did not correlate with the inhibition of cellular proliferation. Our results suggest a possible different suppressor factor in pregnant and cord sera and also excludes the possibility of AFP in cord sera as a suppressor agent of cell-mediated immunity.

Cells, Cultured↗
PubMedDate not supplied

[Organic aciduria: diagnosis in high-risk Brazilian patients]

OBJECTIVE: To determine the prevalence of organic acidurias in high-risk Brazilian patients. METHODS: Laboratory techniques for the detection and quantification of organic acids by gas chromatography/mass spectrometry were implemented in Porto Alegre, Brazil. We investigated 1,480 patients suspected of organic aciduria between January 1994 and June 2000. RESULTS: Seventy three (4.9%) cases of organic acidemias (acidurias) were diagnosed among the tested individuals. In most of these patients, prompt therapy resulted in rapid symptom improvement; these results are completely different from our previous cases diagnosed in other laboratories in Europe and the United States, where several patients died before any measures could be taken. CONCLUSIONS: These results demonstrate the importance of diagnosing organic acidurias in loco even in developing countries, in spite of the extra costs involved.

Journal Article↗
PubMedDate not supplied

[Application of a clinical and laboratory protocol for the investigation of inborn errors of metabolism among critically ill children]

OBJECTIVE: The aim of this work was to evaluate a protocol for investigation of Inborn Errors of Metabolism (IEM) in children who are acutely ill.METHODS: Forty six children with clinical suspicion of a metabolic disorder were studied during 2 years. They were selected through request for investigation of IEM from Pediatrics or Neonatal Intensive Care Units located in the metropolitan area of Porto Alegre. Criteria for inclusion were presence of one or more of the following clinical alterations, without defined etiology: Metabolic acidosis, electrolyte disturbances, hypoglycemia, seizures, lethargy, liver disfunction, family history suggestive of IEM. The protocol included clinical evaluation, compulsory tests (performed in all patients) and optional tests (performed selectively according to the results from the first tests or through specific clinical hypothesis).RESULTS: Six cases of IEM were identified: galactosemia, non-ketotic hyperglycinaemia, propionic acidemia, isovaleric acidemia, 3-hydroxy-3-methylglutaric acidemia and deficiency of 3-ketothiolase deficiency.CONCLUSIONS: The frequency of organic acidurias in this group was 4/46 (8.7%), which justifies the inclusion of organic acids analysis among the first line exams in acutely and severely ill children with undefined etiology. The relatively high frequency of IEM (6/46 or 13%), which is comparable to the ones observed in other studies within high risk groups, indicates that the protocol suggested is efficient and justifies the systematic investigation of IEM in not explained critically ill children.

Journal Article↗