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Biomedical subjects

M Mena

Publications and source records attributed to M Mena.

At least 55 records · Page 3Linked to original sources
PubMedDate not supplied

Cytologic and biomolecular diagnosis of polyomavirus infection in urine specimens of HIV-positive patients.

OBJECTIVE: To evaluate the frequency of human polyomavirus reactivation in urine specimens from HIV-positive patients; compare the sensitivity of cytology, immunohistochemistry and molecular biology; differentiate viral genotypes; and correlate the results with urinary cytologic abnormalities. STUDY DESIGN: Urine specimens from 78 unselected HIV-positive patients were evaluated by means of cytology, immunohistochemistry and nested polymerase chain reaction (n-PCR) to evaluate the presence of polyomaviruses. Restriction fragment length polymorphism (RFLP) was carried out in positive cases in order to differentiate BK virus (BKV) from JC virus (JCV). CD4 cells and serum creatinine levels were evaluated as indices of immune status and renal function, respectively, whereas the presence of red blood cells was used as an index of urogenital damage. RESULTS: Cytologic evidence of polyomavirus infection was found in 17 samples and immunohistochemically confirmed in 9; another 6 cytologically negative cases were detected by means of immunohistochemistry. In all cases, only one or two cells showed typical viral inclusions or positive staining. n-PCR identified 44 positive samples, thus confirming all of the cytologically and immunohistochemically positive cases and detecting polyomavirus genome in a further 21. RFLP detected 39 JCV, 1 BKV and 4 JCV-BKV infections. No correlation was found between the presence or type of polyomavirus and immune status, but red blood cells were found more frequently in the positive than in the negative samples. Serum creatinine levels fell within the normal range in all cases. CONCLUSION: Molecular biology is the most sensitive tool for detecting polyomavirus urinary infection in HIV-positive patients and the only reliable method of differentiating JCV and BKV viral genotypes.

Adult↗
PubMedDate not supplied

Absolute TCD4+ counting by a minimalist dual-platform flow cytometric method.

UNLABELLED: The aim of this work was to compare the performance of an absolute TCD4+ counting method based on total WBC gating versus the standard lymphocyte (Ly) gating method, in order to develop a flow cytometric (FCM) minimalist strategy for TCD4+ enumeration. METHOD: 132 routine peripheral blood samples, mainly from HIV infected patients, were labelled with CD3-FITC/CD4-PE/CD45-PECy5 and analyzed by two gating methods: a) standard method based on Ly immunological gating (CD45++SSClow), followed by the determination of CD3+CD4+ percentage and absolute number (# calculation using Ly # from hematological analyser (HA); b) total WBC immunological gate on biparametric scatter CD45/CD4, followed by CD4++SSClow percentage determination and absolute number calculation using WBC absolute number from hematological counter without using the WBC differential. Moreover on 63 samples Ly # based on Ly % from FCM and WBC counting from HA was compared with Ly # from HA. RESULTS: The TCD4+/microL ranged from 3 to 3277 and the statistical analysis results showed: a) linear regression: r2 = 0.9847; b) Bland & Altman analysis: difference mean = -56.22; agreement range = +95.68 / -208.12; c) the mean of result difference/mean value*100 between two methods was -9.06%; d) comparison between regression line and the boundaries for acceptable residual values based on regressed confidence limits found by A. Kunkl et al showed regression line within boundaries near the upper limits. The Ly/microL count ranged from 635 to 8752. The statistical analysis results showed: a) linear regression: r2 = 0.9764; b) Bland & Altman analysis: difference mean = -362.93; agreement range = +134.51 / -860.37; c) the mean of result difference/mean value*100 between two methods was -16.12%. CONCLUSIONS: Our results suggest a fair agreement between the two gating methods, but the one based on total WBC gate gives TCD4+/microL counts systematically higher than the standard method. This finding can be attributed to a systematic lower estimation of Ly% by HA.

Antibodies, Monoclonal↗
PubMedDate not supplied

[Physiopathology of dystonia].

Dystonia is a movement disorder characterized by sustained twisting movements and muscle contractions and abnormal postures. Dystonia is a symptom present in many diseases of the central nervous system. Anatomical data reveal that dystonia appears in diseases involving the basal ganglia, diencephalon, brain stem and cerebellum. Physiological studies revealed an abnormal facilitation of polysynaptic reflexes at the brain stem level. A common pathogenic mechanism for dystonia must be found in order to delineate in effective treatment. From clinical and biochemical data we suggest that dystonia is produced by abnormal shift to the norepinephrine/dopamine neurotransmission in favor of norepinephrine in different brain areas.

Animals↗
PubMedDate not supplied

[Stability in intellectual performance of students with fetal alcohol syndrome in children homes].

Children with fetal alcohol syndrome (FAS) display great variability in their IQs during follow-up. The course of cognitive performance among twelve school girls aged 10 to 15 years with FAS who lived in foster homes of a chilean public organization for socially handicapped infants, was assessed by comparison of the results of Wechsler's psychometric test for children (WISC) which were done once and repeated 4 years later in the same patients. IQs were 7 to 13 points lower after 4 years in 7/12 girls, slightly better (4 and 6 points) in 2/12 and practically the same in 3/12 patients 1 to 3 points lower. Mean global IQs were 79.58 +/- 11.24 at year 1984 and 74.75 +/- 10.56 in 1988. This IQ reduction, even though not statistically significant, was deeper the more evident were the dysmorphogenic findings.

Adolescent↗
PubMedDate not supplied

[Combined fetal alcohol and hydantoin syndromes].

Ethanol and hydantoin are both teratogenic drugs of common usage and are associated with specific syndromes. This is a report on two children born to different heavy drinking, mentally abnormal epileptic women, that were also under treatment with 300 mg/day of hydantoin (mother of case 1 on a regular basis and that of case 2 sporadically) during pregnancy. Both infants displayed the syndrome due to both of these drugs. Particularly relevant were failure to thrive, severe mental retardation, microcephaly, blepharophimosis, hypertelorism, and long philtrum. Additional findings in case 1 included nail hypoplasia and in case 2 palatine fissure. Case 1 died unexpectedly at age three months. Case 2 is still alive and he is severely mentally retarded at age four years.

Abnormalities, Drug-Induced↗
PubMedDate not supplied

[Antithyroglobulin antibodies and autoimmune thyroiditis in man].

The pathogenic mechanisms responsible for the induction of autoimmune thyroiditis in humans may include the participation of specific antibodies against thyroid antigens. Based on this idea, blood donors were randomly selected from a Hospital and the presence of antibodies against human thyroglobulin in their blood sera was determined. The antibody titer was determined by the micro-method of passive hemagglutination and the resistance to reduction with 2-Mercaptoethanol, tested in the same way. It was found that 11.8% of the normal sera gave positive titers, some of them as high as Log2 11. All positive sera were resistant to 2-Mercaptoethanol. Their possible role in the generation of tissue damage is discussed.

Autoantibodies↗