PubMed Health⌕ Search

Biomedical subjects

S Santos

Publications and source records attributed to S Santos.

At least 73 records · Page 4Linked to original sources
PubMed1990

The macular photostress test in diabetic retinopathy and age-related macular degeneration.

We propose the macular photostress test for the evaluation of macular function in the office setting. Eighty eyes were tested and divided into four diagnostic categories: background diabetic retinopathy, diabetic macular edema, age-related macular degeneration, and normal. The recovery times for the eyes with age-related macular degeneration were longer than for eyes with macular edema (P = .03). Age-matched patients with age-related macular degeneration had longer recovery times than did those without age-related macular degeneration (P = .0001). A possible explanation is that the prolonged recovery time in the eyes with age-related macular degeneration reflects that the anatomic lesion is located in the retinal pigment epithelium-photoreceptor complex. In comparison, the eyes with macular edema, whose lesion is in the inner retina and not the retinal pigment epithelium, show a less-prolonged recovery time than the eyes with age-related macular degeneration.

Adolescent↗
PubMed1989

Fraction from human and rat liver which is inhibitory for proliferation of liver cells.

A comparative study was undertaken with human and rat liver of a fraction reported to have growth inhibitory activity when prepared from rat liver. Fractions which were soluble in 70% ethanol and insoluble in 87% ethanol were prepared from liver cytosols. Electrophoretic analysis under denaturing conditions indicated that there were several quantitative or qualitative differences in the fractions from the two species. Fractions from both human and rat liver were found to be inhibitory for the incorporation of 3H-thymidine into DNA of foetal chick hepatocytes. Under conditions in which the rat fraction inhibited precursor incorporation into DNA of rat liver epithelial cells there was not a significant inhibitory effect with the fraction from human liver. DNA synthesis in a rat hepatoma cell line was not significantly inhibited by preparations from either species. The data suggested that corresponding fractions from both rat and human liver could have inhibitory effects on precursor incorporation into DNA but the magnitude of the effects and target cell specificity may differ.

Animals↗
PubMed1989

[Non-fatal firearm injuries of the head and neck].

There is depicted the evolutive course of 6 men with gunshot wounds of the neck and head, fortunately not threatening their lives. All victims were men between 18 and 67 years of age. Three times the gun fired a single projectile, whereas the other 3 were multiple projectiles. The latter cases resulted in heavier damages. Etiologically the events were classified as: 3 cases as suspected murder, 2 as attempted suicide and in the last case, an accident. The management has been both medical and surgical under general anesthesia, in order to repair the disorders and/or remove the bullets in 5 occasions. The sixth case did not allow removal of the bullet because of expected risk. All the cases did seemingly well, in spite of 2 who had postoperative complications which delayed healing.

Accidents↗
PubMed1989

[Study of hearing in normally-hearing elderly patients. I. Auditory threshold].

Through this paper the AA. examine 504 ears of 252 subjects of both sexes, between 60 and 84, all feeling subjectively normal regarding this sense, without otologic conditions in the past or at present. The explorations done were air and bone tonal audiometry. At the time the results were assessed, the coefficient of variability and standard deviation were kept in mind.

Aged↗
PubMed1989

[Study of hearing in normally-hearing elderly patients. II. Supraliminal tests].

Five-hundred-and-four ears of 252 people, between 60 and 84 years of age have been tested. All of the group had supposedly good hearing, without otic antecedents and free of any complaint related to the ear. The tests done were: recruitment (Lüscher-Zwislocki), tone decay (Carhart) and automatic audiometry (von Békésy). In assessing the results, the coefficient of variability and standard deviation were kept in mind. Lastly, the AA. compare their own results with those attained in other published series.

Aged↗
PubMed1989

Recovery facilitation of malathion-intoxicated freshwater fish by exposure to hypertonic environment.

The possibility of recovery in a hypertonic environment (10-40% NaCl) was investigated in the freshwater fish Oreochromis niloticus acutely intoxicated with the pesticide Malathion (40 mg/l). Survival was significantly higher in 15 g/l NaCl, with a shorter time required to recover posture and swimming, although 20% of recovered animals died on subsequent days. Exposure to a hypertonic environment plus pesticide did not protect the animals. Fish exposed to air until they became unresponsive recovered faster in freshwater than in a hypertonic environment. It is concluded that a hypertonic environment only facilitates recovery and that although osmotic mechanisms may explain the results, other possibilities remain to be investigated.

Animals↗
PubMed1987

A monoclonal antibody to the heavy chain of human IgM with a particular reaction pattern in human B-cell malignancies.

We produced a monoclonal antibody to the human mu-chain. Its specificity was proved by amino acid-sequence analysis of immunoabsorbent purified cell surface antigen. In binding studies an affinity constant (K-aff) of 5.7 X 10(9) M-1 was determined. When compared with a polyclonal anti-IgM antiserum it was found that this antibody may react with a determinant of the mu-chain differently exposed in clonal B-cell disorders rendering it to a reagent of particular diagnostic interest.

Amino Acid Sequence↗
PubMed1984

Visual detection of granulocyte surface antigens using the avidin-biotin complex.

A visual test for detection of granulocyte surface markers using the avidin-biotin complex (ABC) has been developed. That this assay is highly specific, reproducible, and sensitive was determined by studying the expression of HLA antigens on granulocytes with monoclonal antibodies. Further, using granulocyte specific alloantisera, the results of the ABC test compared well to data from leukoagglutination assays and indirect immunofluorescence tests. The assay is particularly advantageous in that granulocytes can be stored, only small amounts of cells and sera are needed, and heterogeneous cell populations can easily be studied.

Agglutination Tests↗
PubMed1984

Platelet crossmatch tests using radiolabelled staphylococcal protein A or peroxidase anti-peroxidase in alloimmunized patients.

Refractoriness to random-donor platelets as a result of alloimmunization remains a major problem in long-term platelet transfusion therapy despite the use of HLA-matched platelets. We have therefore studied the use of two methods for detection of platelet associated IgG as platelet crossmatch tests for the selection of platelet donors. These methods use radiolabelled staphylococcal protein A (125I-SPA) and peroxidase anti-peroxidase (PAP), respectively. One hundred and ten crossmatch tests using 125I-SPA were performed retrospectively in 18 alloimmunized patients. The results indicated that the predictive value of a positive or a negative test was 87%; the sensitivity was 73% and the specificity was 95%. Results with the PAP test were similar. The HLA types were known for 48 donor-recipient pairs. With few exceptions, there was a correlation between the results of the platelet crossmatch tests and the effectiveness of platelet transfusion regardless of the degree of HLA match. These results indicate that platelet crossmatch tests may be valuable even when closely HLA matched donors are not available. A large-scale prospective study is warranted, particularly in highly immunized patients.

Anemia, Aplastic↗
PubMed1981

Histochemical demonstration of terminal deoxynucleotidyl transferase in leukemia.

White blood cells from 22 patients with leukemia and lymphoma were studied for the presence of terminal deoxynucleotidyl transferase with a peroxidase-antiperoxidase method. The enzyme was detected in leukemic cells of 5 patients with acute lymphoblastic leukemia and 1 patient with chronic myelogenous leukemia, whereas 16 patients with different forms of leukemia or lymphoma were negative for this enzyme. Comparative studies using a biochemical and an indirect immunofluorescence assay revealed complete concordance between these three methods.

Animals↗
PubMed1980

Detection of platelet-directed immunoglobin G in sera using the peroxidase-anti-peroxidase (PAP) slide technique.

An immunohistochemical procedure for the detection of immunoglobulin G adherent to platelets is described. The peroxidase anti-peroxidase method is used to detect antibody activity directed against platelets from normal donors in the sera from 305 individuals. These subjects were divided into three groups: group 1, patients referred for tissue typing; group 2, healthy normal females; group 3, healthy normal males. In group 1, 28% of the sera were found to be positive; in most of these a history of prior transfusions was obtained. In group 2, 7.4% were found to be positive, most having previous pregnancies. Only 1% were found to be positive in group 3, and no reason for presensitization was found. Results from the indirect immunofluorescence technique served as a control and as a means to compare the sensitivity. Under the conditions chosen, the peroxidase anti-peroxidase test was two to eight times more sensitive than the immunofluorescence technique. Specificity of the peroxidase anti-peroxidase technique was demonstrated using a monospecific anti-PLA1 antiserum. It is concluded that the peroxidase anti-peroxidase slide technique may be a useful tool in the study of platelet-related immunophenomena.

ABO Blood-Group System↗
PubMedDate not supplied

Effect of dioxin on ovarian function in the cynomolgus macaque (M. fascicularis).

Ovarian function was evaluated in mature female cynomolgus macaques 443 to 625 days following a single oral exposure (1, 2, or 4 microg/kg BW) to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Urinary estrone conjugates (E1C), pregnanediol-3-glucuronide (PdG), and follicle stimulating hormone (FSH) were measured. Three of four animals in the high dose group had no evidence of menstrual cycles while animals in the low and medium dose groups plus one from the high dose group had cycles that were similar to those of control animals. The noncycling animals had baseline E(1)C concentrations without ovulatory midcycle peaks and monotonic PdG profiles. Mean FSH concentrations during the midfollicular phase of the medium dose group and during the entire cycle of the high dose group were elevated compared to those of the control group and the endometria of the noncycling animals were inactive. These data demonstrate that a single exposure of 4 microg/kg BW TCDD leads to long-term adverse effects on ovarian function in primates.

Administration, Oral↗
PubMedDate not supplied

Parathyroid hormone-related protein as a renal regulating factor. From vessels to glomeruli and tubular epithelium.

Parathyroid hormone (PTH) and PTH-related protein (PTHrP) produce similar biological effects through the PTH/PTHrP receptor. Less is known about the physiological role of PTHrP, which was first identified as the agent of the humoral hypercalcemia of malignancy. Despite the widespread production of PTHrP in healthy individuals, the concentration of the protein is below the detectable limit of current assays, suggesting that PTHrP normally functions locally in an autocrine or paracrine manner. Thus, some differences in their biological activities have been described and they may be related to the presence of different receptors. In this regard, a second receptor that binds selectively to PTH has also been found. Recent studies have demonstrated the expression of both PTH/PTHrP receptor and protein in the renal glomeruli. Moreover, there are convincing data that support a direct role of PTH and PTHrP in modulating renal blood flow and glomerular filtration rate. This multifunctional protein, PTHrP, also has a proliferative effect on both glomerular mesangial cells and tubular epithelial cells. Increases in the expression of PTHrP have been observed in several experimental models of nephropathies, suggesting that PTHrP upregulation is a common event associated with the mechanism of renal injury and repair.

Glomerular Filtration Rate↗
PubMedDate not supplied

[Symptomatic epilepsy: review of 208 patients].

OBJECTIVE: To determine the main etiological mechanisms of symptomatic epilepsy and its frequency according to age. PATIENTS AND METHODS: We made a retrospective analysis of 208 patients admitted during a period of four and a half years, studying the variables: age, sex and type of seizures: simple partial, secondarily generalized partial, complex partial, tonic-clonic, generalized tonic, and also EEG and neuroimaging. RESULTS: The main etiological mechanisms found were: vascular (31.25%), alcoholic (12.01%), intracranial disorders (9.61%), traumatic (5.28%), degenerative (5.28%), infectious (2.88%) and cryptogenic (33.65%). In the last group there was an outstandingly large proportion of patients with silent infarcts. When considering vascular epilepsy, those seizures occurring during the acute phase of the stroke (24/65) are differentiated from those of late onset (41/65). In the latter there was a marked predominance of ischemic etiology (48.78% corresponded to extensive infarcts in the territory of the middle cerebral artery; 36.58% were associated with partial infarcts) probably because of the greater frequency of ischemic stroke as compared with hemorrhagic stroke. After the acute phase, the latency was of 10.68 +/- 0.43 months and the most frequent seizures were tonic-clonic (48.78%). CONCLUSION: In persons under 30 years of age, etiology is multifactorial; between 30 and 50 years of age alcoholic epilepsy (39.53%) and traumatic epilepsy (11.62%) predominate; over the age of 50 years the cause was vascular in 43.5%. In the latter age group there was a high proportion of patients with heraldic seizures.

Acute Disease↗
PubMedDate not supplied

[Incidence of otosclerosis in a subpopulation of Galicia, Spain].

We have made a prospective study of the patients who were analysed for the first time at the Outpatients Department in the Otolaryngology Section of the University Complex Hospital of Santiago de Compostela all along 1997. A whole of 1,050 patients have been included in this study. The most frequent diagnosis were neurosensorial hypoacusis (29.1%), chronic otitis media (27.8%) and in the third place, otosclerosis. This appeared in 83 cases, which represents a 8.7% of the fulfilled diagnosis. The incidence for our health area reached 19 new cases of otosclerosis per 100,000 inhabitants a year. When only the number of stapedectomies were included, it reached a 7.8%. The prevalence of the female population was clear, reaching a 77%. Diagnosed patients' age was from 30 to 50 years, although a considerable percentage (37%) were older. The incidence reached by our studies is higher to other values previously published. We think this responds to the fact that the health system covers all the population and to the importance a good audition is given nowadays.

Adolescent↗
PubMedDate not supplied

[Transient global amnesia: a review of 58 cases].

INTRODUCTION: Transient global amnesia (TGA) is a clinical condition in which the etiopathogenesis is still not clear. The most generally accepted theory is of a vascular origin, although epilepsy or migraine have also been considered to possibly be the cause. OBJECTIVE: To make a retrospective review of the risk factors, etiopathogenesis and clinical characteristics of 58 patients with TGA. PATIENTS AND METHODS: The variables recorded were compared with those from two control groups: one of healthy individuals and one of patients with transient ischemic attacks (TIA). RESULTS: The average age of the patients with TGA was 66.01 years. The risk factors included: arterial hypertension (58.62%), dyslipemia (15.51%) and migraine (8.62%). In three patients the EEG showed weak bilateral frontotemporal interference. Cerebral CT scans were done in all cases and were found to be pathological in 23, with lacunar multinfarct the commonest abnormality. With regard to patients with TIA, these were older (66.01 vs 72.94), smoked more (1.72% vs 12.06%) and a previous stroke was more frequent (8.62% vs 31.03%). We did not find differences regarding dyslipemia, atrial fibrillation, arterial hypertension or cardiac ischemia. However, the prevalence of vascular risk factors was significantly higher in patients with TGA as compared to healthy controls. CONCLUSION: We suggest that the etiopathogenesis of TGA is probably a transient ischemic phenomenon triggered (or not) following an attack of migraine.

Adult↗