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Biomedical subjects

B R Elejalde

Publications and source records attributed to B R Elejalde.

At least 19 recordsLinked to original sources
PubMed2002

Single photon emission computerized tomography (SPECT) in detecting neurodegeneration in Huntington's disease.

Single photon emission computerized tomography (SPECT) studies were performed on 34 manifest Huntington's disease (HD) patients at various stages of clinical pathology ranging from early chorea to late dystonia with or without signs of dementia and 12 pre-symptomatic patients with abnormal terminal CAG expansions. Thirty HD patients with obvious clinical signs and seven pre-symptomatic patients without signs or symptoms of HD displayed selective caudate hypoperfusion by direct visual inspection. Such qualitative, selective striatal hypoperfusion patterns can be indicative of early and persistent metabolic changes in striatal neuropathology. SPECT studies can be useful in documenting early pre-clinical changes in patients with abnormal terminal CAG expansions and in confirming the presence of caudate pathology in patients with clinical signs of HD.

Adult↗
PubMed2001

Up-regulation of WNT-4 signaling and dosage-sensitive sex reversal in humans.

Wnt-4, a member of the Wnt family of locally acting secreted growth factors, is the first signaling molecule shown to influence the sex-determination cascade. In mice, a targeted deletion of Wnt-4 causes the masculinization of XX pups. Therefore, WNT-4, the human homologue of murine Wnt-4, is a strong candidate gene for sex-reversal phenotypes in humans. In this article, we show that, in testicular Sertoli and Leydig cells, Wnt-4 up-regulates Dax1, a gene known to antagonize the testis-determining factor, Sry. Furthermore, we elucidate a possible mechanism for human XY sex reversal associated with a 1p31-p35 duplication including WNT-4. Overexpression of WNT-4 leads to up-regulation of DAX1, which results in an XY female phenotype. Thus, WNT-4, a novel sex-determining gene, and DAX1 play a concerted role in both the control of female development and the prevention of testes formation. These observations suggest that mammalian sex determination is sensitive to dosage, at multiple steps in its pathway.

Amino Acid Sequence↗
PubMed1998

A multicenter investigation with interphase fluorescence in situ hybridization using X- and Y-chromosome probes.

Twenty-six laboratories used X and Y chromosome probes and the same procedures to process and examine 15,600 metaphases and 49,400 interphases from Phaseolus vulgaris-leucoagglutinin (PHA)-stimulated lymphocytes. In Part I, each laboratory scored 50 metaphases and 200 interphases from a normal male and a normal female from its own practice. In Part II, each laboratory scored 50 metaphases and 200 interphases on slides prepared by a central laboratory from a normal male and a normal female and three mixtures of cells from the male and female. In Part III, each laboratory scored 50 metaphases (in samples of 5, 10, 15, and 20) and 100 interphases (in samples of 5, 10, 15, 20, and 50) on new, coded slides of the same specimens used in Part II. Metaphases from male specimens were scored as 98-99% XY with no XX cells, and 97-98% of interphases were scored as XY with 0.04% XX cells. Metaphases from female specimens were scored as 96-97% XX with 0.03% XY cells, and 94-96% of interphases were scored as XX with 0.05% XY cells. Considering the data as a model for any probe used with fluorescence in situ hybridization (FISH), a statistical approach assessing the impact of analytical sensitivity on the numbers of observations required to assay for potential mosaicisms and chimerisms is discussed. The workload associated with processing slides and scoring 50 metaphases and 200 interphases using FISH averaged 27.1 and 28.6 minutes, respectively. This study indicates that multiple laboratories can test/develop guidelines for the rapid, efficacious, and cost-effective integration of FISH into clinical service.

Cytogenetics↗
PubMed1994

Primary syphilis and nonimmune fetal hydrops in a penicillin-allergic woman. A case report.

The incidence of congenital syphilis is on the rise. Penicillin continues to be the drug of choice for it during pregnancy. A penicillin-allergic woman with primary stage syphilis who was treated initially with erythromycin presented with fever and nonimmune fetal hydrops secondary to an intrauterine syphilitic infection. Following desensitization and penicillin therapy the fetal hydrops disappeared, the pregnancy continued to term, and the patient delivered a small-for-gestational-age but other-wise normal infant who continued to do well up to 1 year of age.

Adult↗
PubMed1994

DNA testing and genetic counseling: truth or consequences.

Advances in medical genetics are providing a major clinical challenge to practitioners seeing patients concerned about their risk of developing either inherited disease or susceptibility to acquired disease. Popular information can easily exceed our professional ability to provide services to well-read patients who want answers with scientific certainty. The challenge also involves ethical questions regarding confidentiality and the way that results are disclosed. More often than not, the test itself becomes the focus of psychosocial expectations for the future and lifestyle of the patient and family. The behavioral consequences of disclosure of test results need to be anticipated by the caregiver to avoid adverse psychological outcomes.

DNA↗
PubMed1990

Prospective study of amniocentesis performed between weeks 9 and 16 of gestation: its feasibility, risks, complications and use in early genetic prenatal diagnosis.

This paper demonstrates that the outcome of amniocenteses performed between the 9th and the 14th weeks is similar to that of amniocenteses performed between the 15th and 20th weeks. We have performed and prospectively followed 615 amniocenteses between the 9th and 16th weeks of gestation. The outcome, risks, and complications are similar to those of amniocenteses at the usual time (after 15 weeks) and to the other groups of early amniocentesis (before 15 weeks). Early amniocentesis differs from amniocentesis at the usual time in that it carries higher rates of fetal losses and of amniotic fluid leakage, more confined cytogenetic abnormalities, and an increased number of patients who have the procedure postponed. Two cultures (0.32%) failed to produce results, 595 (96.7%) samples were obtained at the first tapping, 20 (3.3%) at the second attempt. alpha-Fetoprotein levels reach their maximum at 13 weeks. Amniocenteses between 15 and 16 weeks (293, or 47%) constitute the control group, those between 9 and 14 weeks (322) the experimental group. Early amniocentesis appears to be a safe early genetic prenatal diagnosis technique, an alternative to chorionic villi sampling.

Amniocentesis↗
PubMed1986

The prenatal growth of the human body determined by the measurement of bones and organs by ultrasonography.

This paper presents the ultrasonographic analysis of the growth of two groups of human fetuses, one longitudinal and the other cross-sectional. Measurements of all the long bones were taken, as well as measurements of the following diameters: Biparietal, occipitofrontal, thoracic and abdominal anterior/posterior and transverse, spinal canal width, arm, forearm, thigh and leg transverse. The bladder and the stomach were also measured. The pregnancies analyzed covered the period between the 8th and 38th week of gestation. Centiles (3rd-97th) were calculated for each structure and week. All pregnancies known or suspected to be abnormal were removed from the study. The values obtained were tested in 102 pregnancies (test group); the expected values (from the graphs) did not deviate from the values obtained from this group of fetuses, demonstrating the reliability of the values presented in these graphs. All structures measured showed linear growth. There was no significant difference between the longitudinal and cross-sectional groups.

Adolescent↗
PubMed1986

Determination of cholinesterase and acetylcholinesterase in amniotic fluid. Uses in prenatal diagnosis and quality control.

The determination of acetylcholinesterase (AChE) has been shown to be as specific as alphafetoprotein (AFP) for the prenatal detection of open neural tube defects although AFP remains the method of choice. This paper describes a semi-automated technique for the analysis of acetylcholinesterase in amniotic fluid that: A) reduces the cost of the procedure; B) allows for a larger number of samples to be run at a time; and C) provides for more accurate and reproducible procedures and results. Six fetuses with neural tube defects (2 with gastroschisis and 3 where one twin was dead) were detected and found to have elevated AChE, TChE and 2 bands by electrophoresis. Quality control procedures using both pure enzyme and amniotic fluid with low and high levels of the enzyme are described. The analysis of 340 amniotic fluids of normal pregnancies indicates that the normal value for AChE is 5.17 +/- 2.63 mU/ml (97% confidence interval for the mean 4.84-5.49 mU/ml. A group of 27 abnormal pregnancies provides evidence that fetal vomiting and regurgitation, fetal demise, multiple cysts syndrome, idiopathic IUGR, arthrogryposis multiplex, hydrocephaly (stenosis of aqueductus), trisomy 21, trisomy 18, hydronephrosis, pyloric stenosis, heart malformation, ectopia cordis and multiple gestation produce elevated levels of pseudocholinesterase (PChE) in amniotic fluid. The use of pseudocholinesterase levels in amniotic fluid for prenatal diagnosis is proposed and discussed in view of its elevated levels in abnormal pregnancies where AChE is normal. The normal values for PChE are 23.86 mU/ml (mean) and 5.83 for standard deviation. Electrophoretic analysis was performed on all samples with values higher than one standard deviation above the mean.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholinesterase↗
PubMed1985

Analysis of the human fetal skeleton and organs with xeroradiography.

We have used xeroradiography to study normal and abnormal fetuses including some with anencephaly, hydrocephalus, spina bifida, osteogenesis imperfecta (type IV), Jeune syndrome, radial aplasia, thanatophoric dysplasia, and Pena-Shokeir syndrome. Xeroradiography images the lines of ossification and epiphyses in great detail, shows ossification, and reveals abnormalities that alter bone modeling as seen in Jeune syndrome, osteogenesis imperfecta (type IV), and thanatophoric dysplasia. This technique can be used successfully to examine soft tissues and organs. It can also be used in combination with contrast materials to identify the lateral ventricles, the cardiovascular, gastrointestinal, urinary, and respiratory systems, and the cavities (pleural and peritoneal) of the fetal body.

Abortion, Incomplete↗
PubMed1985

Nuchal cysts syndromes: etiology, pathogenesis, and prenatal diagnosis.

We examined 10 fetuses with nuchal cysts and compared the findings with 32 cases from the literature. Based on their characteristics, we propose that nuchal cysts are signs of four causally and pathogenetically different entities: cystic nuchal blebs present in otherwise normal fetuses as a postmortem change; 45,X fetuses who have a particular appearance and multiple congenital malformations; an apparently autosomal recessive syndrome of multiple cysts (that extend into deep muscular planes), generalized edema, cleft palate, peculiar skeletal characteristics, acutely angulated ribs (producing a bell-shaped rib cage), and shortened long bones; and in fetuses with syndromes that are inherited (multiple pterygium, Roberts) and chromosomal (trisomy 13, trisomy 21) as an unspecific sign representing both primary and secondary lesions.

Abnormalities, Multiple↗
PubMed1985

Prenatal diagnosis of Jeune syndrome.

We describe two sibs affected with Jeune syndrome. The first was diagnosed after birth and the second was diagnosed prenatally using ultrasonography. The detected abnormalities were confirmed by X-ray and autopsy following pregnancy termination. This observation indicates the possibility of prenatal diagnosis of the condition.

Adult↗