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J Brown

Publications and source records attributed to J Brown.

At least 703 records · Page 39Linked to original sources
PubMed1990

Radiolabeled antifibrin antibody in the detection of venous thrombosis: preliminary results.

The recent development of monoclonal antibodies against components of coagulated blood may provide new approaches to the diagnosis of venous thrombosis. Scanning with an indium-111-labeled Fab fragment of a murine monoclonal antifibrin antibody (59D8) and ascending contrast venography were performed in 33 patients. Images of the calves, popliteal fossae, thighs, and pelvis were obtained immediately, 4-6 hours, and 24 hours after injection of 2 mCi (74 MBq) of the antibody. All images were read in a blinded manner. Findings in both studies were positive in 28 patients and negative in three. In 19 patients not undergoing heparin therapy, 19 specific anatomic sites were positive on venograms and 29 were positive on antibody images (19 sites matched). In 14 patients undergoing heparin therapy, 34 sites were positive on venograms and 27 were positive on antibody images (22 sites matched). In most patients, positive results were noted within 1 hour of antibody injection. No adverse effects were noted with the antibody preparation. Preliminary data suggest that antifibrin antibody imaging is sensitive in detecting clots, is safe to use, and may have a role in diagnosing and managing venous thrombosis.

Adult↗
PubMed1990

Renal masses: evaluation with gradient-echo Gd-DTPA-enhanced dynamic MR imaging.

Dynamic contrast material-enhanced gradient-echo magnetic resonance (MR) imaging was performed on 15 patients with 18 renal masses (seven simple renal cysts, nine renal cell carcinomas, one angiomyolipoma, and one oncocytoma). Fifteen sequential images were obtained while the patients held their breath during a 2.5-3.5-minute interval during and immediately after the intravenous administration of gadolinium diethylenetriaminepentaacetic acid (DTPA); delayed images were also obtained for 15 minutes. Time-intensity curves showed that renal cortical enhancement reached maximal intensity 80 seconds after the injection of Gd-DTPA. Medullary enhancement reached maximal intensity at 120 seconds. None of the simple renal cysts showed enhancement; each cyst displayed a signal intensity less than that of the renal cortex on precontrast images. All renal cell carcinomas were isointense with the renal cortex and demonstrated variable enhancement. Three patterns of enhancement were observed: predominantly peripheral, heterogeneous, and homogeneous. Both the angiomyolipoma and the oncocytoma showed brisk, homogeneous enhancement. This MR imaging technique appears to be useful in the detection and characterization of simple renal cysts and solid neoplasms.

Adenoma↗
PubMed1990

Autoradiographic localization of atrial and brain natriuretic peptide receptors in rat brain.

Displacement of bound 125I-labeled atrial natriuretic peptide-(1-28) [alpha 125I-ANP-(1-28)] by alpha-ANP-(5-28) and porcine brain natriuretic peptide (BNP) was used to map receptors common to these peptides in rat brain by in vitro autoradiography. alpha-125I-ANP bound reversibly to subfornical organ, area postrema, median preoptic, supraoptic and paraventricular nuclei, and arachnoid mater. Binding at these sites was displaced similarly by 1 microM unlabeled alpha-ANP, alpha-ANP-(5-28), and BNP. Binding dissociation constants in the subfornical organ and arachnoid were 4.40 +/- 1.15 and 3.99 +/- 0.86 nM, respectively, for alpha-ANP, and 2.41 +/- 1.11 and 2.23 +/- 1.06 nM, respectively, for BNP. alpha-125I-ANP also bound to choroid plexus. Here 1 microM unlabeled alpha-ANP displaced significantly more radioligand than did 1 microM BNP, and the concentration displacing 50% of bound radioligand was 2.23 +/- 0.78 nM for alpha-ANP and 1.51 +/- 0.67 nM for BNP. alpha-ANP-(5-28) also displaced alpha 125I-ANP at all sites with significantly greater affinity than did unlabeled alpha-ANP. alpha-125I-ANP was not displaced by completely unrelated peptides. Therefore, both atrial and brain natriuretic peptides may be high-affinity ligands at common receptors in some cerebral localities.

Animals↗
PubMed1990

Distribution of atrial natriuretic peptide receptor subtypes in rat brain.

The presence and distribution of atrial natriuretic peptide (ANP) clearance receptors in rat brain were investigated by use of des[Gln18,Ser19,Gly20,Leu21,Gly22]ANP-(4-2 3) (C-ANP), a specific ligand of this receptor, to displace bound alpha-125I-labeled ANP. alpha-125I-ANP (200 pM) bound significantly to arachnoid mater, subfornical organ, choroid plexus, area postrema, median preoptic nucleus, and supraoptic and paraventricular nuclei. Binding was reversible at all sites with unlabeled alpha-ANP. Binding dissociation constants for alpha-ANP were measured for the first three sites and were all in the nanomolar range. C-ANP competed with alpha-125I-ANP only for binding sites on arachnoid mater, 1 microM C-ANP displacing radioligand from at least 60% of these sites. No alpha-125I-ANP was displaced by completely unrelated peptides. The reversible binding of 125I-Tyr0-ANP-(5-25), another relatively selective ligand of the clearance receptor, was also concentrated on arachnoid mater. Therefore, high-affinity binding sites for alpha-ANP on arachnoid mater may be clearance receptors for ANP.

Animals↗
PubMed1990

Autoradiographic localization of atrial natriuretic peptide receptor subtypes in rat kidney.

The distribution of atrial natriuretic peptide (ANP) clearance receptors in rat kidney was investigated by in vitro autoradiography using des[Gln18,Ser19,Gly20,Leu21,Gly22]-ANP-(4- 23) (C-ANP) and 125I-Tyr0-ANP-(5-25) as relatively specific ligands of this receptor. Alpha-125I-ANP (100 pM) bound reversibly but with high affinity to glomeruli, outer medullary vasa recta bundles, and inner medulla. C-ANP (10 microM) inhibited greater than 60% of this glomerular binding but did not inhibit the binding of alpha-125I-ANP to medullary tissues. Alpha-125I-ANP also bound reversibly to the renal arteries up to the glomerulus. This arterial binding was only partly inhibited by 10 microM C-ANP. In the presence of 10 microM C-ANP, increasing concentrations of alpha-125I-ANP bound to a residue of glomerular sites with apparent dissociation constants of 0.82 +/- 0.16 to 2.73 +/- 1.20 nM at different cortical levels. 125I-Tyr0-ANP-(5-25) bound significantly to glomeruli and intrarenal arteries but not to vasa recta bundles or inner medulla. This glomerular binding also occurred with nanomolar dissociation constants. It was completely inhibited by 1 microM alpha-ANP and 10 microM C-ANP, but not by unrelated peptides such as gastrin. These results suggest that renal ANP clearance receptors are restricted in vivo to the glomeruli and renal arterial system of the rat.

Animals↗
PubMed1990

Renal atrial natriuretic peptide receptor subtypes in spontaneously hypertensive rats.

Receptor subtypes for atrial natriuretic peptide (ANP) were characterized in kidneys of 18-wk-old Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR) by in vitro autoradiography through use of des[Gln18, Ser19, Gly20, Leu21, Gly22] ANP-(4-23) (C-ANP) and ANP-(5-25) as subtype-selective ligands. alpha-125I-ANP (100 pM) bound reversibly but with high affinity to glomeruli, to stripes in outer medulla, and to inner medulla of both WKY and SHR. C-ANP (10 microM) inhibited approximately 70% of the glomerular binding but none of the medullary binding in either strain. All high-affinity specifically reversible binding sites for alpha-ANP that bound C-ANP were also bound by 10 microM ANP-(5-25). However, the specifically reversible binding of alpha-125I-ANP that was not inhibited by 10 microM C-ANP behaved differently in each strain. In WKY, this binding was weakly inhibited by ANP-(5-25), so that even the presence of 10 microM ANP-(5-25) did not inhibit some glomerular binding and greater than 40% of the specifically reversible medullary binding of alpha-125I-ANP. In SHR, this binding was inhibited by ANP-(5-25) with a significantly higher affinity so that all specifically reversible binding of alpha-125I-ANP was inhibited by 10 microM ANP-(5-25). SHR also showed higher affinities but lower maximum binding capacities for alpha-ANP in their outer cortical glomeruli and medullas. These results suggest that the preponderant medullary ANP receptor differs between WKY and SHR. Differences in glomerular subtypes of ANP receptor may also distinguish WKY and SHR.

Animals↗
PubMed1990

Acute changes in atherogenic and thrombogenic factors with cessation of smoking.

Tobacco smoking is associated with alterations in several factors considered to be important in the atherosclerotic process. Thirty chronic smokers were studied 2 weeks before and 2 weeks after complete tobacco withdrawal. Significant reductions in fibrinogen, haematocrit, plasma viscosity and whole blood viscosity as well as a significant increase in HDL-cholesterol were observed. As these factors are important in both atherogenesis and thrombogenesis, these observations may give insight into tobacco-induced atherosclerotic disease and may be responsible for the more rapid reduction in the incidence of cardiovascular disease that is believed to occur after stopped smoking.

Adult↗
PubMed1990

Nurses' perceptions of parent and nurse roles in caring for hospitalized children.

Twenty-five nurses were interviewed and asked to describe their perceptions of parent and nurse roles in caring for hospitalized children. Data were analyzed using content analysis. Six types of roles were identified: providing nonmedical care; providing technical and medical care; being a gatekeeper; being an advocate; providing psychosocial care; and providing general care. It seemed that often the nurses' need for control influenced the psychoemotional care they provided for parents.

Attitude of Health Personnel↗
PubMed1990

Microflora associated with the skin of the bowhead whale (Balaena mysticetus).

A study of the microbiological flora isolated from cultures of normal and lesional skin tissue samples collected from 19 bowhead whales (Balaena mysticetus) over a 4 yr period is presented. These cultures were obtained from 30 tissue samples (17 normal, 13 lesion) and 248 swab samples (157 normal, 91 lesion). Seven hundred-thirty bacterial and yeast isolations were made (285 normal, 445 lesion). Distribution revealed that 56% of the gram positive bacterial isolates, 75% of the gram negative bacterial isolates and 64% of the yeast isolates recovered were associated with lesional skin. It was found that 80% of one group of Corynebacterium sp. isolates, 90% of the Acinetobacter sp. isolates and 94% of the Moraxella sp. isolates were associated with lesional skin. Although the primary yeasts recovered were Candida spp., they were found on both normal and lesional skin. Enzymatic assays of isolates from normal and lesional skin demonstrated production of enzymes capable of causing necrosis. The majority of the microorganisms recovered were facultative anaerobes and many of them could be considered potential pathogens of mammalian hosts.

Animals↗
PubMed1990

Augmentation of release of gastric somatostatin-like immunoreactivity by adenosine, adenosine triphosphate and their analogs.

The effect of adenosine, adenosine 5'-triphosphate (ATP) and ATP analogs on basal gastric somatostatin-like immunoreactivity (SLI) release was studied using the vascularly perfused rat stomach. The release of gastric SLI was stimulated by adenosine (0.6-60 microM) concentration dependently, while the release of immunoreactive gastrin was inhibited by 1 and 10 microM adenosine. The stimulatory action of adenosine was probably mediated by adenosine receptors because the receptor antagonist, 8-phenyltheophylline, abolished the action of adenosine. In addition, the adenosine-induced release of SLI was not mediated by a cholinergic or beta-adrenergic mechanism, since atropine, hexamethonium or propranolol did not block the action of adenosine. Dipyridamole enhanced the adenosine-stimulated, but not 2-chloroadenosine-induced SLI release. Since the adenosine analog, 2-chloroadenosine, is resistant to the adenosine uptake mechanism, it is likely that adenosine-stimulated release of gastric SLI is due to the activation of extracellular receptors. ATP also stimulated gastric SLI release. The analogs alpha,beta-methyleneadenosine triphosphate and diphosphate, which are resistant to metabolic breakdown, did not stimulate basal SLI release, while gamma,beta-methyleneadenosine triphosphate, which can be metabolized, increased the release of SLI. In addition, the ATP-induced release of SLI was abolished by 8-phenyltheophylline. Therefore, the action of ATP is likely to be a result of its metabolism to adenosine.

2-Chloroadenosine↗
PubMed1990

The association of xerostomia and inadequate intake in older adults.

Recent studies indicate that nearly one in five older adults has xerostomia (dry mouth). Salivary gland dysfunction and/or inadequate saliva increases the difficulty of these older adults in obtaining proper nutrition. Problems in lubricating, masticating, tolerating, tasting, and swallowing food contribute notably to the complex physiological and psychological manifestations of aging. To our knowledge, the literature has not demonstrated an association between xerostomia and malnutrition in the elderly. We randomly selected 67 older adults from institutionalized and free-living geriatric populations. Nutritional intake analysis was performed on both groups of study subjects, who were found to have xerostomia by use of sialometry, and on control subjects matched for age, sex, and physical status. Intake of total energy, protein, dietary fiber, total fat, saturated fat, cholesterol, sodium, potassium, vitamin A, vitamin C, thiamin, riboflavin, vitamin B-6, calcium, iron, and zinc was compared with the 1989 Recommended Dietary Allowances. Subjects' intakes were also compared with that of a control group. Medical systemic information and number and types of medications were compared among the groups. Statistical analysis of the data indicated significant (p less than .001) inadequacies in the nutritional intake patterns of institutionalized and free-living older adults with xerostomia. Subjects with xerostomia (more than 75% of the free-living and institutionalized seniors) had significant deficiencies of fiber, potassium, vitamin B-6, iron, calcium, and zinc. Taste and food perception were significantly reduced in the elders with xerostomia. Our study indicates the potential contribution of xerostomia to the high prevalence of geriatric malnutrition in the United States.

Aged↗
PubMed1990

Noninvasive measurement of renal blood flow with technetium-99m-DTPA in the evaluation of patients with suspected renovascular hypertension.

If a hypertensive patient with renal artery stenosis (RAS) is to benefit from percutaneous transluminal renal angioplasty (PTRA) in terms of a sustained improvement in blood pressure control, one may postulate a demonstrable reduction in renal blood flow (RBF) to that kidney, reversible by PTRA. In a population of 32 hypertensive patients, RAS was present in 23 of 62 kidneys. Eleven of the 32 patients underwent renal revascularization, of whom 6 showed improvement in blood pressure control at 6 mo, i.e., had renovascular hypertension (RVH). There was no correlation between RBF and angiographic appearances of the renal artery. Furthermore, there was no significant difference between RBF in the stenosed kidneys of the patients with RVH compared with the stenosed kidneys of patients without RVH. Individual kidney RBF was 22% (s.d. 11) higher 1-3 wk after PTRA but the increase did not correlate with clinical outcome. Angiotensin converting enzyme (ACE) inhibition increased RBF by 25% (s.d. 25) of baseline flow before PTRA but the increase did not correlate with clinical outcome. Measurement of RBF is of limited value for the prediction of the long-term blood pressure response following PTRA.

Angiography, Digital Subtraction↗