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Biomedical subjects

M Varela

Publications and source records attributed to M Varela.

At least 55 records · Page 3Linked to original sources
PubMed1991

Ullrich-Turner syndrome in mother and daughter: prenatal diagnosis of a 46,X,del(X)(p21) offspring from a 45,X mother with low-level mosaicism for the del(X)(p21) in one ovary.

A woman with Ullrich-Turner syndrome but with normal secondary sex characteristics became pregnant on two occasions (ages 23 and 24). She had a 45,X karyotype in 100/100 lymphocytes and 50/50 skin fibroblasts. The first pregnancy ended in a miscarriage at 2 months of gestation. In the second pregnancy cultured amniocytes showed a 46,X,del(X)(p21) karyotype. This pregnancy resulted in an apparently normal girl. Biopsies of the mother's ovaries were obtained at the time of cesarean section. Grossly the ovaries appeared normal, and histologically the number of primordial follicles appeared normal. In the right ovary, 5/100 cells were 46,X,del(X)(p21), while all 100 cells in the left ovary were 45,X.

Adult↗
PubMed1991

Transient expression of trisomy 21 and monosomy 7 following cyclosporin A in a patient with aplastic anemia.

We present a patient with severe idiopathic aplastic anemia with no previous chromosomal abnormalities who developed trisomy 21 and monosomy 7 during treatment with intravenous (i.v.) cyclosporine. The abnormal karyotype disappeared when the drug was changed to the oral form. This cytogenetic aberration, previously unreported in association with cyclosporine, may reflect either a direct drug effect or the emergence of a hidden myelodysplastic cell clone subject to preferential survival during immunosuppression.

Administration, Oral↗
PubMed1989

Age-related changes in the motor response to environmental novelty in the rat.

To examine age-related changes in responsiveness to environmental novelty, 3-, 12-, and 24-month-old male Fischer 344 rats were maintained on a restricted diet and exposed to a modified open field for 10 min on each of 10 consecutive days. On the first day of testing, animals of all groups showed equal amounts of rearing. While the 3-month animals continued to show approximately the same levels of rearing until the 8th day, by day 5, the older groups (12- and 24-month) had significantly reduced their rearing. Conversely, grooming was initially highest among the 24-month-old animals. While 3- and 12-month rats showed habituation of grooming, the oldest animals failed to habituate their grooming response by day 5. By day 10, there were no significant differences among the groups in either rearing or grooming. Although food was available in the center of the modified open field, there was little eating and there were no differences among groups. However, all animals did eat quickly when food was made available in their home cages. Thus, all animals displayed a profile of stress-related responses to open field exposure. Plasma corticosterone levels likewise were elevated in the modified open field. Some, but not all, components of this response profile habituated over the 10 days of exposure. Three-month-old animals responded to the novelty predominantly by rearing and 24-month animals predominantly by grooming. This suggests that with aging, locomotor responses to stress are replaced by a more self-directed form of displacement activity.

Aging↗
PubMed1987

Prenatal diagnosis of a 46,XX,inv(12)pat/47,XX,i(Xq),inv(12)pat.

A 46,XX,inv(12)pat/47,XX,i(Xq),inv(12)pat was diagnosed prenatally in a 36-year-old woman whose husband was a known carrier of a pericentric inversion of chromosome 12. The diagnosis was confirmed in fetal tissue. Terminal bromodeoxyuridine (BrdU) labelling demonstrated that in the line with 46 chromosomes one X was late replicating, while one X and the i(Xq) were late replicating in 100% of the cells with 47 chromosomes. We present the first case of this type of sex chromosome mosaicism. Genetic counseling presented difficulties since it was not possible to predict the fetal phenotype.

Adult↗
PubMed1986

Dexamethasone suppresses pituitary-adrenal but not behavioral effects of centrally administered CRF.

Intracerebral ventricular (icv) administration of corticotropin-releasing factor (CRF) significantly enhances the expression of stress-related behaviors in the rat and also activates the pituitary-adrenal system. The pituitary-adrenal response can be blocked by pretreatment of animals with dexamethasone. The behavioral effects (motor activation, increased grooming and decreased eating) on the other hand are resistant to suppression by dexamethasone. The independence of the behavioral effects from activation of the pituitary-adrenal axis suggests that stress-induced release of CRF could contribute to behavioral alterations even in the presence of high concentrations of endogenous steroids.

Adrenocorticotropic Hormone↗
PubMed1984

NOR associations with heterochromatin.

Associations between nucleolus organizer regions (NORs) and non-acrocentric chromosomes were scored in 2,800 metaphase spreads from PHA-stimulated lymphocyte cultures (48 h) from 14 individuals. The preparations were both silver stained and C-banded. In order to calculate the expected values for associations, the ratio of heterochromatin length to euchromatin length was established for each subject. Individual C-band lengths and centromeric lengths were also determined. When silver connective (SC) associations with heterochromatin were compared to SC associations with euchromatin, the number of associations with heterochromatin was significantly greater than expected (P less than 0.000001) for each subject. The SC associations were not distributed randomly over the heterochromatin of the non-acrocentrics. Chromosomes 1 and 2 had significantly more than expected. Chromosomes 17, 18, 19, 20, and the Y had fewer than expected. NOR associations with euchromatic segments also showed a nonrandom pattern of distribution.

Chromosome Banding↗
PubMed1983

NOR activity and satellite association patterns in a family carrying a doubly satellited marker.

Activity and association patterns of nucleolar organizer regions (NORs) were studied in cultured blood lymphocytes from six members of a family, three of whom carried a doubly satellited marker. The marker consisted of a centromere with two sets of satellites and stalks which showed consistent NOR activity. The children with the marker had significantly higher frequencies of NOR activity and satellite association than their non-carrier siblings. The acrocentrics of the children with the marker did not appear to have decreased association tendency.

Cells, Cultured↗
PubMed1980

Clonal changes in chronic granulocytic leukemia in blastic transformation and during remission.

Cytogenetic studies of the peripheral blood and marrow of a patient with chronic granulocytic leukemia in blastic transformation revealed the following abnormalities: 1) a Philadelphia chromosome with the usual 9:22 translocation; 2) a three break rearrangement (insertion) of chromosome #11; and 3) a deletion of the short arm in chromosome #16. Clinical and hematologic remission developed after three courses of intermittent chemotherapy with transient but complete bone marrow aplasia. Studies performed during remission revealed two cellular clones. One had the same karyotype already described and the second showed only a Ph1 chromosome. We postulate that the pretreatment clone evolved from Ph1-positive cells in this patient with chronic granulocytic leukemia during a short, undiagnosed stable phase. Treatment allowed the reappearance of the Ph1-positive clone. The second abnormal clone was apparently partially eradicated but normal cells did not repopulate the bone marrow, suggesting that either the Ph1-positive cells were greatly resistant to therapy or that there were no remaining normal myelogenous stem cells. In addition, we found that there have been few reports of abnormalities involving chromosomes #11 and #16, and that an inserting chromosome #11 has never been reported.

Bone Marrow↗
PubMed1979

Local tolerance of i.m. mezlocillin injection.

To evaluate the intensity of the localized pain caused by intramuscular administration of 6-[(R)-2-[3-methylsulfonyl-2-oxo-imidazolidine-1-carboxamido]-2-phenyl-acetamido]-penicillanic acid sodium salt (mezlocillin, Baypen), the pain was compared to that caused by ampicillin in a blind test. Ampicillin served as reference because of its extensive use. 50 patients were given 1 g of mezlocillin and 1 g of ampicillin successively, in both gluteal regions. Ampicillin is significantly more painful than mezlocillin. However, substantial pain is produced by both drugs. In a second study, to reduce the pain, 50 patients were given 1 g of mezlocillin twice, one injection was given in a period of 5-7 s, and the other in a 12-15 s period. The slower injection is significantly less painful than the faster one. In conclusion, i.m. administration of mezlocillin is less painful than that of ampicillin, and the slow injection reduces the pain of mezlocillin administration.

Ampicillin↗
PubMed1978

Multiple endocrine adenomatosis: in support of the common origin theories.

Herein we give clinical support to the theory of a common origin of multiple endocrine adenomatosis. Accurate clinical evaluation of a patient suspected to have endocrine neoplasia requires the search for a much wider range of potential endocrine tumors. Such an approach is now made possible by the radioimmunoassay. Chromosome patterns and histocompatibility antigens are reviewed in a family with the disease.

Adult↗
PubMed1975

The correspondence between some motor points and acupuncture loci.

A double blind study was conducted to establish the possible correspondence between some motor points and acupuncture loci. The protocol calls for the acupuncturist marking the first group of volunteers with invisible ink at the acupuncture loci. Then the motor points in the same volunteer are found by electrodiagnosis. The error is made visible by UV illumination. In the second group, the procedure is reversed. A statistical analysis of the error yields the following classes of correspondences: (a) Excellent: 1st Dorsal Interosseus (hand) = LI-4; Abductor Pollicis Brevis = Lu-10; Abductor Minimi Digiti = SI-4; 1st Dorsal Interosseus (foot) = LI-3; Tibialis Anterior = Curious Locus; Orbicularis Oculi = GB-1; Frontalis = GB-14; Splenius Capitis = GB-20; Sternocleidomastoid = LI-18; Semi Spinalis Capitis = BI-10. (b) Good: Opponens Pollicis = Curious Locus; Peroneus Longus = Curious Locus; Flexor Digitorum Longus = Ki-3 (Ki-6); Trapezius (upper) = GB-21; Rectus Abdominis = Ki-15; Vastus Medialis = Sp-10.

Acupuncture Therapy↗