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Biomedical subjects

S Watson

Publications and source records attributed to S Watson.

At least 163 records · Page 9Linked to original sources
PubMed1976

(Vinylaryloxy)acetic acids. A new class of diuretic agents. 1. (Diacylvinylaryloxy)acetic acids.

A series of (diacylvinylaryloxy)acetic acids was synthesized and tested in dogs for saluretic and diuretic activity. Several compounds exhibit a high order of activity, the most active being [2,3-dichloro-4-(2,2-diacetylvinyl)-phenoxy]acetic acid (3). This compound is about three times as potent as [2,3-dichloro-4-(2-methylenebutyryl)-phenoxy]acetic acid (ethacrynic acid) but is qualitatively similar in causing a prompt increase in the excretion of water and in the excretion of sodium and chloride ions in approximately equimolar amounts. Saturation of the double bond of 3 virtually abolishes activity lending support to the hypothesis that the saluresis induced by these compounds, like that of ethacrynic acid, is related at least in part to a chemical reaction with protein-bound sulfhydryl groups. Four mercaptan adducts of 3 were prepared; these probably function as prodrugs in producing saluresis. The adduct with mercaptoacetic acid is as active as 3 itself.

Acetates↗
PubMed1975

Limulus lysate test for gram-negative bacterial meningitis. Bedside application.

The limulus lysate on cerebrospinal fluid was evaluated in 335 infants and children as a method for the rapid diagnosis of Gram-negative bacterial meningitis. Positive limulus tests were obtained within one hour in 33 of 34 cases of Hemophilus influenzae meningitis; four additional patients with Gram-negative meningitis also showed positive limulus lysate tests. Conversely, 13 patients with Gram-positive bacterial meningitis all yielded negative limulus assays. All 48 cases of aseptic meningitis and 236 children with no meningitis showed negative limulus assays. Antibiotic therapy prior to hospitalization did not vitiate the validity of the test. A bedside adaptation of the limulus test, performed by house officers and medical students, showed approximately 98% agreement with the laboratory assay.

Arachnida↗
PubMed1975

The nitroblue tetrazolium test in patients with advanced neoplastic diseases.

The nitroblue tetrazolium test (NBT) was evaluated in 111 patients with cancer. Patients were placed into control and "presumed infected" groups. The mean NBT score for the control group, 6.3, was significantly greater than the mean for a group of normal volunteers, 3.1, but the mean score for the "presumed infected" group, 15.6 was significantly higher. Less than 10 percent of the patients with bacterial infection had scores below 10, while 15 percent of the control patients had unexplained high scores. A method for concentrating leukocytes is described which makes the NBT test feasible in patients with granulocytopenia. Morphological changes in granulocytes used as indicators of infection are unreliable markers in cancer patients, in whom such changes occur frequently in the absence of infection. We have found that the NBT test is more useful as an indicator of infection in patients with cancer.

Bacterial Infections↗
PubMedDate not supplied

The signal peptide of pro-opiomelancortin: validation of a specific radioimmunoassay.

The N-terminus portion of the POMC leader sequence (signal peptide) was synthesized, and an antiserum was raised against it. A radioimmunoassay was developed which is effective at a dilution of 1:500,000, and sensitive at less than 1 fmole/tube. Since leader sequences often exhibit structural homologies, and since synthetic peptides are not readily available, we resorted to an unusual procedure to establish specificity. This involved extraction of pituitary RNA, cell-free translation to produce the pre-prohormones, and purification by B-END and signal antibody affinity columns. The eluates were then tested by SDS gel electrophoresis and by multiple immunoprecipitations. All results showed that the signal antibody captured a single molecular species, approximately 30,000 in MW, which was also captured by the B-END column, and was immunoprecipitable by B-END and ACTH antisera. It therefore appears that this antibody selectively measures the POMC leader sequence and should be valuable in measuring the newly synthesized pre-prohormone.

Amino Acid Sequence↗
PubMedDate not supplied

Immunohistochemical localization of aminopeptidase M in rat brain and periphery: relationship of enzyme localization and enkephalin metabolism.

An antiserum specific for rat aminopeptidase M has been used for the immunohistochemical localization of the enzyme in rat brain and peripheral tissues. The enzyme in brain is localized exclusively on blood vessels. Within the pituitary the enzyme was associated with the vasculature in the posterior lobe, on the surface of the intermediate lobe and on the surface of some cells in the anterior lobe. In the liver, fine cell staining was observed between parenchymal cells, in the ileum the entire lumenal surface was stained, while in the kidney both proximal tubular and a central tubular staining was detected. In each tissue aminopeptidase M is localized such that it can limit diffusion across specific barriers. Aminopeptidase M activity in brain has been proposed to function in the degradation of synaptically released enkephalins. Its localization on blood vessels requires that enkephalins diffuse prior to degradation, a concept not in concert with current hypotheses. Based on these studies it is proposed that diffusion away from enkephalinergic synapses plays a key role in terminating enkephalin action.

Aminopeptidases↗
PubMedDate not supplied

Relationships between symbolic play, functional play, verbal and non-verbal ability in young children.

It is well established that certain aspects of play in young children are related to their emerging linguistic skills. The present study examined the relationships between functional play, symbolic play, non-verbal ability, and expressive and receptive language in normally developing children aged between 1 and 6 years using standardized assessment procedures, including a recently developed Test of Pretend Play (ToPP). When effects of chronological age were partialled out, symbolic play remained significantly correlated with both expressive and receptive language, but not with functional play or non-verbal ability; and functional play was only correlated significantly with expressive language. It is concluded that ToPP will provide practitioners with a useful way of assessing symbolic ability in children between the ages of 1 and 6 years, and will contribute to the assessment and diagnosis of a number of communication difficulties, and have implications for intervention.

Child↗
PubMedDate not supplied

Soy phytoestrogens improve radial arm maze performance in ovariectomized retired breeder rats and do not attenuate benefits of 17beta-estradiol treatment.

OBJECTIVE: Soy phytoestrogens (SPEs) seem to have beneficial effects on the cardiovascular system with no adverse effects on the breast and uterus. Our objective was to examine the effects of oral estradiol alone, soy protein with phytoestrogens alone, and combinations of estradiol and SPEs on working memory of ovariectomized retired breeder female rats using the radial arm maze test. DESIGN: Eighty-four bilaterally ovariectomized retired breeder female rats were randomized into 12 groups to examine the effects of chronic treatment (10 months) with oral micronized estradiol (0, 0.5, 1, and 2 mg/1,800 Cal), SPEs (0, 72, and 144 mg/1,800 Cal), and all combinations of these doses of estradiol and SPEs on working memory. RESULTS: Oral administration of estradiol or SPEs resulted in a dose-dependent improvement in the performance of the radial arm maze tests. In addition, at each of the three doses of oral micronized estradiol tested, the performance of the radial arm tests was not significantly different in the presence or absence of SPEs. CONCLUSIONS: Our data suggest that SPEs may function as estrogen agonists in improving working memory in the ovariectomized retired breeder female rats and that SPEs do not antagonize the beneficial effects of estradiol on the working memory of these rats. No additional benefits on the radial arm maze test performance were observed with the tested combinations of estradiol and SPEs.

Animals↗
PubMedDate not supplied

Rapid turnover transport proteins, plasma albumin, and growth in low birth weight infants.

The purpose of this investigation was to establish normative data and to determine the value of measuring rapid plasma turnover proteins in low birth weight infants during the neonatal period. Forty-three premature, adequate for gestational age infants were divided in three groups according to their birth weight: group A less than 1000 g, group B 1001 to 1500 g, group C 1501 to 2000 g. Weekly anthropometric measurements and biochemical determinations were obtained. Anthropometric measurements included weight, crown heel length, midtricipital skinfold thickness, and midarm circumference. Biochemical studies in plasma included total proteins, albumin, prealbumin, and retinol-binding protein. A significant increase in prealbumin concentration preceded weight gain. The elevation in prealbumin concentration was statistically significant (p less than 0.02) for the combined data from all groups and for infants included in group B and C (p less than 0.05). No concomitant changes were demonstrated in plasma retinol-binding protein, or total proteins. The transient rise in prealbumin plasma concentrations remains unexplained, but may be related to the infant's nutritional status.

Anthropometry↗
PubMedDate not supplied

A ward of their own.

Explore the source record for details and available documents.

Adolescent↗