Search PubMed⌕ Search

Biomedical subjects

M L Alonso

Publications and source records attributed to M L Alonso.

32 records · Page 2Linked to original sources
PubMed1987

Chromosome abnormalities in AIDS-associated lymphadenopathy.

Cytogenetic studies were performed on direct and 24-hour culture preparations of eight lymph node biopsies from seven patients with acquired immunodeficiency syndrome (AIDS) or AIDS-related complex (ARC)-associated lymphadenopathy in whom histological evidence of lymphoma was not detected. Three of these seven had chromosomal abnormalities, including chromosome instability in one and clonal chromosomal abnormalities in two; one of the latter was a t(8;14)(q24;q32). The remaining five showed normal karyotypes. Epstein-Barr virus (EBV) titers were elevated in all three patients that exhibited chromosome abnormalities, two of whom later developed malignant lymphoma. A control group of five patients with reactive lymphadenopathy not associated with AIDS failed to reveal chromosomal aberrations, but elevated EBV titers were present in two. These data are consistent with current views on the role of EBV and chromosome change in the development of lymphoma in immunodeficient states and suggest that karyotypically abnormal AIDS-related lymphadenopathy represents a prelymphomatous proliferation.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Prenatal diagnosis of minute 5p- deletion: a cytogenetic problem in detection.

An unbalanced translocation, 46,XX,der(5)t(5;11) (p15;q25)mat was ascertained by prenatal diagnosis. The mother previously had a liveborn child with cri du chat syndrome. The subtlety of the chromosome rearrangement in this case illustrates the need for the most detailed cytogenetic investigations in cri du chat cases when deletion or translocation are not immediately obvious.

Adult↗
PubMed1986

Analysis of meiotic segregation in a man heterozygous for two reciprocal translocations using the hamster in vitro penetration system.

Sperm chromosomal complements of a man heterozygous for two reciprocal translocations and exhibiting the karyotype 46,XY,t(5;11) (p13;q23.2),t(7;14)(q11;q24.1) were analyzed following in vitro fusion with golden hamster zona-free eggs (the hamster in vitro penetration [HIP] system). Products of alternate, adjacent 1, and 3:1 segregation at meiosis I of both translocation quadrivalents were recovered, and the analysis of their output, which was dissimilar between the two translocations, permitted prediction of probable sites of chiasma formation in the chromosomes involved in the translocation. These data, which comprise the first reported analysis of the products of two translocations in a single individual (hence, in a common genetic background), emphasize the uniqueness in genetic behavior of individual translocations; they further demonstrate the usefulness of the HIP system to carry out such studies.

Animals↗
PubMed1985

Effect of chorionic villus sampling on serum alpha fetoprotein levels.

Chorionic villus sampling (CVS) is a recent advance in prenatal diagnosis in the first trimester. maternal serum alpha fetoprotein (AFP) screening for neural tube defects is done from 14-17 weeks gestation. Previous studies have shown an elevation of AFP levels following amniocentesis. The aim of this study was to determine the effect of CVS on AFP levels immediately following this procedure. CVS was performed under sonographic guidance on 22 patients between 6 and 12 weeks gestation undergoing elective termination of pregnancy. A Portex catheter was used for obtaining villi. Maternal serum AFP levels were ascertained before and after CVS by radioimmunoassay. In the group of patients 8 weeks or less, no change in AFP levels was seen; in patients greater than 8 weeks gestation, a significant rise in post-biopsy AFP level was noted in 7 of 14 patients. Further studies are planned to clarify the effect of CVS on AFP levels in patients with ongoing pregnancies. Clarification of this issue is important to the role of CVS in prenatal screening.

Adult↗
PubMed1984

Immunomodulatory activity of isoprinosine on experimental viral infections in avian models.

The immunomodulatory activity of Isoprinosine treatments have been experimentally verified on chicken infected by three different viruses: Newcastle disease, fowl plague and avian infectious bronchitis. In protection tests, positive variations in the mean day of death rather than in the mortality rate were found depending on the modality of treatment. A stimulatory influence on primary anti-Newcastle disease virus antibody response was observed. In the avian model the Isoprinosine antiviral effect appears as due mainly to the enhancement of interferon production and to a synergistic interferon-isoprinosine interaction.

Adjuvants, Immunologic↗
PubMed1983

'In vivo' variations in serum interferon levels produced by antiviral compounds.

The effects of adamantane, amantadine, and glucosamine on the interferon induction in chickens as compared to mice were studied. Nonviral and viral inductions were produced either by Pseudomonas aeruginosa endotoxin or by some orthomyxoviridae. After establishing their toxicity, single treatments with the drugs were intraperitoneally administered at two different doses 36, 24, and 12 h before or 2 h after the time of interferon induction. Data obtained show that adamantane and its derivative amantadine are able to inhibit the 'in vivo' interferon synthesis only when viral inductors are used; possibly by impairing the necessary stimulative action of the viral nucleic acid at the replication level. Glycosylation inhibitors like glucosamine were uneffective on interferon induction 'in vivo'.

Adamantane↗
PubMed1982

Variations in host defence mechanisms and blastogenesis in chickens and mice after rifamycin treatments.

The immunobiological effect of rifamycins on different experimental models has been comparatively studied in chickens and mice using cyclophosphamide as a reference immunosuppressive agent. "In vivo" treatments with rifampicin and rifamycin SV diminished interferon levels in chickens and mice up to two hours after virus challenge. Mitogen induced blastogenesis was significantly depressed by either "in vivo" (5-50 mg/kg) or "in vitro" (5-20 micrograms/ml) drug treatments, although the activation of B lymphocytes was more easily inhibited than that of T lymphocytes. Primary anti-SRBC immune responses suffered a similar immune suppressive action by rifamycin treatments "in vivo". In every case, cyclophosphamide (10-20 micrograms/ml "in vitro" and 25 mg/kg "in vivo") proved to be the most active immunosuppressant. On the other hand, a remarkable parallelism in the effect of rifamycins in chickens and mice was observed in all the experimental systems used.

Animals↗
PubMed1982

Mid-pachytene chromomere maps of human autosomes.

Using a method of chromosome preparation which yielded pachytene spermatocytes with exceptionally well spread bivalents, we undertook detailed chromomere analysis of each of the 22 autosomal bivalents stained with orcein or quinacrine. A maximum of 442 chromomeres were recognized and mapped at mid-pachytene. The chromomere maps of pachytene chromosomes presented here corresponded well with the high resolution banding maps of somatic chromosomes at the 850 band stage described in the International System for Human Cytogenetic Nomenclature (ISCN, 1981). Our observations of other features of the pachytene chromosomes, such as the parameters, also agree well with previous reports.

Aged↗
PubMed1978

Early quantification of experimental myocardial infarction with technetium-99m glucoheptonate: scintigraphic and anatomic studies.

Recent advances in understanding of the pathophysiology of myocardial necrosis indicate the need for a noninvasive method that will allow detection and quantification of infarcts in the first few hours after the onset of infarction. Myocardial infarct scintigraphy using technetium-99m glucoheptonate is capable of detecting infarction in dogs and man within 4 to 6 hours of onset. Studies were performed in 45 dogs with acute myocardial infarction: 28 with with an anterior infarct, 5 with an inferior infarct, 6 with an anterior infarct studied after infusion of mannitol and 6 with ligation of the left anterior descending coronary coronary artery and reperfusion of the ischemic area. The dogs were given 20 m Ci of technetium-99m glucoheptonate 1 hour after coronary occlusion, subjected to imaging 5 to 9 hours later and then killed. The experiments revealed that (1) scintigraphic infarct size correlated with infarct weight for anterior (r = 0.85) and inferior (r = 0.88) infarcts; (2) technetium-99m glucoheptonate also concentrated in a rim of myocardium around the infarct that probably represented the ischemic zone; and (3) technetium-99m glucoheptonate uptake by infarcted myocardium could be greatly increased with mannitol and reperfusion.

Animals↗
PubMedDate not supplied

[A model of extreme insulin resistance with carbohydrate intolerance in a patient with Werner's syndrome].

We present the study of a patient suffering insulin resistance with Werner's syndrome which had abnormal glucose tolerance determined by euglycemic fixing ("Clamp") using an artificial pancreas (Biostator GCIIS, Miles Martin) and the binding of insulin to its receptor in erythrocytes. The results obtained show a dose-response curve of insulin serum levels to dextrose infusion rate, shifted significantly to the right and bottom which indicates a diminished insulin sensitivity; similarly a moderate decrease in receptor is obtained with no decrease in their affinity and absence of abnormalities in contraregulatory hormones. These results are compatible with a postreceptor alteration.

Blood Glucose↗