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Biomedical subjects

L Sanchez

Publications and source records attributed to L Sanchez.

At least 73 records · Page 4Linked to original sources
PubMed1989

Time-course levels of alpha 2-macroglobulin and albumin in cow colostrum and milk and alpha 2-macroglobulin levels in mastitic cow milk.

Time-course levels of alpha 2-macroglobulin and albumin in cow's colostrum and milk during lactation were investigated in order to obtain data that could help to elucidate the biological role of alpha 2-macroglobulin in mammary secretions. Levels of these proteins were also studied in mastitic cow milk and were related to the degree of mastitis, which could allow its use as a mastitis marker. The highest concentration of alpha 2-macroglobulin was found in the first milking (386.7 micrograms/ml). This value decreased very rapidly during the colostral period, attaining its definitive value during the 2nd wk postpartum (4.5 micrograms/ml). The albumin/alpha 2-macroglobulin ratio increased by 6.8 in the first milking to 44.4 at 2 wk postpartum, indicating that the increase of alpha 2-macroglobulin was greater than that of albumin. In mastitic cow's milk, the concentration of alpha 2-macroglobulin (48.1, 71.4, and 89.0 microgram/ml) was also higher than that in normal milk. This increase was found to be related to the degree of mastitis as determined by the California Test.

Animals↗
PubMed1985

Scintigraphic demonstration of a diaphragmatic defect as the cause of massive hydrothorax in cirrhosis.

A 64-year-old man presented with a massive right-sided hydrothorax associated with cirrhosis of the liver. There was no clinical evidence of ascites nor other underlying disease. The usual complementary tests failed to demonstrate any causative abnormality. Chest and abdominal scintigraphy after intraperitoneal injection of 99mTc-human serum albumin disclosed early filling of the pleural space by the radiopharmaceutical and suggested a diaphragmatic defect as the cause for this rare association.

Diaphragm↗
PubMed1984

The formation of visual stimulus equivalences in children.

Four normal children were presented a series of matching-to-sample tasks, using five sets of visual stimuli designated A, B, C, D, and E. Stimulus equivalences were established by matching stimuli from one set to those from another set. Each set consisted of three stimuli, so matching set A to set D meant that each stimulus in set A served as a sample with all three stimuli in set D as comparisons. Subjects were first taught AD and DC matching and were then able to perform AC/CA matching without additional training. After ED was taught directly, CE/EC and AE/EA performances emerged. Following CB training, three new equivalences were demonstrated: AB/BA, EB/BE, and DB/BD. Oral naming of each stimulus showed that subjects had not assigned a common label to stimuli in the same class, indicating that naming is not necessary for the formation of stimulus equivalences. The absence of response mediation suggests that matching to sample can form direct stimulus-stimulus associations. The data also provide support for the notion that generative performances are outcomes of existing stimulus-control relationships.

Child↗
PubMed1981

Clinical evaluation of high copper amalgam restorations.

A comprehensive clinical investigation of amalgam restorations was undertaken to evaluate the performance of "high copper' amalgams and the methods used to examine the marginal integrity of restorations. Six alloys, Aristaloy CR (A), Dispersalloy (D), Indiloy (I), an experimental "high copper' amalgam (E), Tytin (T), and New True Dentalloy (N) as a control, were randomly placed by four operators in 435 Class 1 and Class II restorations. Black and white 1 x photographs were taken at baseline, 6, 12 and 18 months and evaluated using the method described by Mahler & Marantz (1979). In addition, the U.S. Public Health Service system (Cvar & Ryge, 1971) was used at each recall. An analysis of variance based on photographic scoring indicated significant differences (P less than 0.05) among alloys at each recall. The use of Duncan's multiple range test resulted in two homogeneous subsets at 18 months: D, I, E and T, N, A. Six and 12 months recall data showed a close similarity in the rank order of the six alloys. The U.S.P.H.S. system showed no statistically significant differences between the alloys using the chi-square test, however, at each recall the rank order was comparable to that obtained with the photographic method.

Chemical Phenomena↗
PubMed1979

Carcinoma of the penis: analysis of 192 consecutive cases at the Instituto Nacional de Enfermedades Neoplasicas.

Between 1952 and 1976 192 consecutive cases of penile epidermoid carcinoma were seen at the Instituto Nacional de Enfermedades Neoplascias of Lima, Peru. The mean age when the disease developed was 60.5 years, with a peak incidence between 60 and 64 years (32 patients). No correlation was observed between extensive lesions of the shaft of the penis to high pathological staging. Clinical examination of the inguino-crural nodes is not a good criterion for staging. We wait six weeks after eradication of primary lesion before lymphadenectomy. No correlation exists between grade and pathological stage. When no lymph node was positive, the overall survival rate over five years was 90.69%; when lymph nodes were metastasized there was an overall survival rate over five years of only 9.39 percent. The coefficient of cancer versus noncancer cause of death was 1.25 for pathological stage I, 3.09 for pathological stage II, 4.83 for pathological stage III, and 10.000 for pathological stage IV. Our patients did have advanced disease, as 57.14% of deaths occurred at two years and 25.21% more at five years.

Adult↗
PubMed1975

Simultaneous ribosomal resistance to trichodermin and anisomycin in Saccharomyces cerevisiae mutants.

A spontaneous mutant of Saccharomyces cerevisiae resistant to trichodermin has been isolated. It displays cross resistance both in vivo and in vitro to a number of sesquiterpene antibiotics (fusarenon X, trichothecin and verrucarin A) and to the chemically unrelated antibiotic anisomycin. The mutation conferring resistance to anisomycin and trichodermin is expressed in the 60-S subunit of the yeast 80-S ribosome. Mutant ribosomes bind [-14C]trichodermin much less efficiently than wild type ribosomes, suggesting that resistance may be due, at least in part, to this property. However, both types of ribosomes bind [-3H] anisomycin equally. These results suggest that anisomycin and trichodermin have different binding sites on the 60-S subunit of eukaryotic ribosomes, even though previous results have shown that both antibiotics bind to mutually exclusive sites.

Anti-Bacterial Agents↗
PubMedDate not supplied

Selective uptake and sustained expression of AAV vectors following subcutaneous delivery.

BACKGROUND: Recombinant adeno-associated viral (rAAV) vectors are capable of long-term expression of secreted and intracellular proteins following delivery to muscle, liver, and the central nervous system. In this study, we have evaluated subcutaneous injection of rAAV encoding a variety of transgenes as an alternative route of administration for the systemic delivery of therapeutic proteins. METHODS: rAAV vectors encoding the human factor IX, human interferon-alpha 2a, murine erythropoietin (epo), and Escherichia coli lacZ genes were used for subcutaneous delivery into mature immunocompetent mice. Expression of factor IX and interferon in mouse serum was measured by ELISA. Expression of Epo was monitored by an increase in hemotocrit and by RIA. The tissue tropism of AAV transduction was determined by histochemistry following administration of the lacZ vector. RESULTS: Long-term protein expression (at least one year) is demonstrated in the serum of immunocompetent mice following subcutaneous delivery of AAV vectors encoding the human factor IX and interferon genes. The murine epo gene delivered via this route resulted in levels of Epo that correlate with increased hematocrits of up to 90% for a duration of nine months. rAAV encoding the lacZ gene revealed that the panniculus carnosus, a skeletal muscle layer of the skin, was transduced upon subcutaneous administration. CONCLUSIONS: This study shows that long-term expression of secreted proteins can be achieved using rAAV vectors injected subcutaneously as a single administration. The observation that the panniculus carnosus is the primary tissue transduced by rAAV illustrates the high tropism of rAAV for skeletal muscle.

Animals↗
PubMedDate not supplied

Two-year decline in vision but not hearing is associated with memory decline in very old adults in a population-based sample.

BACKGROUND: Recent cross-sectional research in cognitive aging has demonstrated a robust association between visual acuity, auditory thresholds and cognitive performance in old age. However, the nature of the association is still unclear, particularly with respect to whether sensory and cognitive function are causally related. OBJECTIVE: This study aimed to determine whether marked declines in performance on screening measures of either visual acuity or auditory thresholds have an effect on cognitive decline over 2 years. METHODS: The sample from the Australian Longitudinal Study of Ageing (n = 2,087) were assessed in 1992 and 1994 on measures of sensory and cognitive function as part of a larger clinical assessment. A quasi-experimental design involving comparison of extreme groups using repeated measures MANCOVA with age as a covariate was used. RESULTS: Group performance on measures of hearing, memory, verbal ability and processing speed declined significantly. Decline in visual acuity had a significant effect on memory decline, but not on decline in verbal ability or processing speed. Decline in hearing was not associated with decline in any cognitive domain. CONCLUSION: The common association between visual acuity, auditory thresholds and cognitive function observed in cross-sectional studies appears to be disassociated in longitudinal studies.

Aged↗
PubMedDate not supplied

Survey of the perceived benefits and shortcomings of a specialist tinnitus clinic.

Questions about the clinical effectiveness of tinnitus services are of considerable interest to health professionals and health care providers alike in view of the chronic nature of tinnitus, the diversity of tinnitus-related problems, and the range of costs of different approaches to the clinical management of tinnitus. This study sought to identify the views of patients with tinnitus, who attended a specialist tinnitus clinic in Wales, about their satisfaction with that service. One hundred and forty-eight patients returned an open-ended mail-out questionnaire that asked them to list the perceived benefits and shortcomings of attendance at the specialist clinic. The respondents were classified as current or very recent attenders (43 per cent) and those who had first attended between 18 to 60 months earlier (57 per cent). Respondents cited an average of 2.8 benefits compared to only 0.8 perceived shortcomings per respondent. Major areas of perceived benefit included technical assistance, in the form of hearing aid or tinnitus masker fitting, and the general therapeutic nature of the consultation(s) with clinic staff. Statistically significant differences were found in some volunteered benefits in relation to gender and patient status as a current or previous attender. More than one-quarter of the respondents (28.4 per cent) stated that there were no shortcomings to their clinic attendance. The main volunteered shortcoming was lack of treatment effectiveness. The study showed that tinnitus clinic attendance resulted in many of the patients' individually expressed complaints being addressed effectively. Further, the study's findings confirmed the effectiveness of the provision of information and counselling as a fundamental form of tinnitus management for a substantial proportion of patients with tinnitus.

Adult↗
PubMedDate not supplied

Induction of Fc receptors on murine macrophages and leukemic cells by interleukin-1 beta.

Recombinant human interleukin-1 beta (rhIL-1 beta) is shown to be a strong inducer of Fc receptors (FcR) on murine macrophages and not on granulocytes. Data is provided indicating that rhIL-1 beta does induce specific but not nonspecific phagocytosis. Macrophages are shown to autoinduce their FcR expression as a function of time in culture. This induction is increased by the use of exogenous rhIL-1 beta and inhibited by anti-rhIL-1 beta antibody, pointing to an autocrine regulation of FcR expression on macrophages. On the other hand the myelomonocytic cell line WEH13BD- and the macrophage like cell line WR19M.1 are also shown to be inducible for the expression of FcR by this molecule. Data is also provided showing that recombinant murine Interferon gamma (rmIFN gamma) induces FcR on both macrophages and granulocytes. Whereas polyclonal antibodies inhibit FcR induction by IL-1 on macrophages, it does not inhibit FcR induction by IFN gamma on these cells. This points to a different mechanism of induction of FcR by IFN and IL-1. Finally, the possible application of rhIL-1 beta in vivo to help the organism fight infections is discussed.

Animals↗