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Biomedical subjects

J Rosen

Publications and source records attributed to J Rosen.

At least 145 records · Page 8Linked to original sources
PubMed1988

Comparative plasma concentration profiles after i.v., i.m. and rectal administration of pethidine in children.

Plasma concentration-time curves of pethidine and norpethidine were studied in 25 children allocated after operation to three groups to receive pethidine 1 mg kg-1 i.v., i.m. or rectally. Peak concentrations occurred after 5 +/- 1, 10 +/- 2, and 60 +/- 10 min, respectively, while the maximum concentrations amounted to 2800 +/- 462, 1609 +/- 367 and 531 +/- 179 nmol litre-1, respectively. The area under the curve (0-240 min) was similarly reduced in the group with rectal administration (P less than 0.05). Compared with the i.v. data, approximately 40% systemic availability occurred after rectal application, although considerable individual variation was noted. In one child very high plasma concentrations were observed after rectal administration, possibly as a result of redistribution/recirculation phenomena. The average results are similar to those obtained when other opioids are given rectally.

Administration, Rectal↗
PubMed1988

Prism adaptation in Parkinson's disease.

Prism adaptation is impaired by lesions in the basal ganglia in non-human primates, suggesting that this area is involved in this form of visuomotor learning. We investigated the ability of patients with Parkinson's disease to prism adapt. Patients and controls wore prisms which deflected vision laterally by 11 degrees. After baseline testing with a localisation task that permitted no feedback about performance accuracy, prism adaptation was tested at 4 minute intervals over a 28 minute trial. All subjects erred initially, reaching too far to the left of the target, but a separate pointing task encouraged adaptation and reaching error decreased at a similar rate in Parkinsonians and controls. Immediately after the prisms were removed, all subjects reached to the right of the target. This negative after effect was present in controls but not patients when assessed 4 minutes later, suggesting that the patients could not maintain the new sensorimotor relationship imposed by the prisms after their removal. This is similar to performance on visuospatial and executive tasks in Parkinsonians, where ongoing behaviour cannot be modulated without external guidance.

Adaptation, Ocular↗
PubMed1988

Immunoregulatory effects of catrix.

The immunoregulatory effect of Catrix on in vitro and and in vivo antibody production was examined in mice. Catrix, an acidic mucopolysaccharide complex, contains glycosaminoglycans including chondroitin sulfate. Catrix-S, a soluble derivative, was found to enhance T-dependent and T-independent antibody responses in vivo in a dose-dependent manner, with 100 mg intraperitoneally or 10 mg intravenously being optimal. Lower doses were found to be less effective or inhibitory. In vitro, the enhancing activity of Catrix-S on proliferative response was additive with that of dextran sulfate and lipopolysaccharide but not with chondroitin sulfate C. This immunoaugmenting activity appears to be related to the chondroitin sulfate component of Catrix-S, because both have similar effects on in vivo and in vitro antibody responses and because chondroitinase ABC inactivates activity. The inhibitory activity of Catrix-S could be separated from its stimulatory effects by ammonium sulfate precipitation or by fractionation according to molecular weight. The immunoaugmenting effect was present in the 0-30% saturated ammonium sulfate precipitate and in the 5-10,000-m.w. and 30-100,000-m.w. fractions. The ability of Catrix-S to enhance antibody responses in nude as well as in normal mice, and antibody responses to T-independent as well as to T-dependent antigens, indicates that its activity is due in part to a direct effect on B cells and/or to an indirect effect mediated by macrophages.

Adjuvants, Immunologic↗
PubMed1988

Herpes zoster ophthalmoplegia. Report of six cases.

Ophthalmoplegia occurs infrequently in herpes zoster ophthalmicus. The third nerve appears to be the most commonly affected and the fourth nerve the least. We describe herein the clinical course of six patients with herpes zoster ophthalmoplegia. Spontaneous recovery occurred in four patients. The pathogenesis and clinical features of this syndrome are described.

Abducens Nerve↗
PubMed1987

The chemiluminescence activity of peripheral blood mononuclear cells during acute experimental allergic encephalomyelitis.

The spontaneous chemiluminescence activity (CL-A) of peripheral mononuclear cells (MNC) was examined in Lewis rats with acute experimental allergic encephalomyelitis (EAE), compared to rats immunized with complete adjuvant (n = 11) and healthy animals (n = 16). In rats with EAE, CL-A increased sharply 8-9 days after immunization (3420 +/- 3124 counts/10 s, n = 16) at the time of flattening of the weight curve. This CL-A peak was compared to that of animals immunized with complete adjuvant: 765 +/- 441 counts/10 s (P = 0.01) and healthy rats: 450 +/- 172 counts/10 s (P = 0.0001). After this initial peak in EAE rats, CL-A decreased almost to normal values when animals lost weight (746 +/- 251 counts, n = 19) and tail paralysis developed (557 +/- 251 counts/10 s, n = 15). CL-A increased again with the onset of paralysis of the extremities (1527 +/- 990 counts/10 s, n = 11), followed by a decrease as the clinical course deteriorated. Finally, CL-A approached normal values as the animals improved. A significant increase in the number of meningeal (P less than 0.01) and perivascular (P less than 0.01) cells in the CNS coincided with the initial CL-A peak. Gel filtration of the serum of rats with increased CL-A revealed at least one substance, with a molecular weight between 13,700 and 43,000 Da, which stimulated the CL-A of normal mononuclear cells.

Acute Disease↗
PubMed1987

In search of closure: subjective contour illusions, Gestalt completion tests, and implications.

This study investigates the construct validity of perceptual closure tests (CTs), and isolates a common processing demand from the right-hemisphere. Sixty-seven patients with focal unilateral lesions (34 right side, 33 left side), and 80 control subjects participated. Multivariate analyses indicated that there was substantial age-related variance in all CTs, while sex was variably significant; CTs are not uniform in their discriminating ability, and hence factorially complex; and their specifically right hemisphere-sensitive dimension was subjective contour illusions, and interestingly unrelated to facial discrimination ability. The methodological and theoretical implications are discussed.

Brain Damage, Chronic↗
PubMed1987

Antibody to a synthetic oligopeptide in subjects at risk for human immunodeficiency virus infection.

Detection of antibodies to human immunodeficiency virus (HIV) by enzyme-linked immunosorbent assay (ELISA) is the accepted method to screen blood products at risk to transmit infection. The presence of antibodies to HIV in 565 serum specimens from 274 patients with acquired immunodeficiency syndrome (AIDS) or AIDS-related complex, symptomatic and asymptomatic subjects at risk for AIDS, and controls was determined with an ELISA that incorporates synthetic peptides (designated E32/E34) representing sequences in the envelope glycoprotein gp41. Of 105 specimens from patients with AIDS or AIDS-related complex, 3 specimens that were negative by commercially licensed ELISA and immunoblot test were similarly unreactive in the E32/E34 ELISA. For homosexual men with generalized lymphadenopathy, 186 specimens were positive by the E32/E34 ELISA and 63 specimens were negative. In comparison, with the licensed ELISA, 184 of these samples were positive and 65 samples were negative. The two samples that were positive in the E32/E34 ELISA but not the commercial kit were also positive by immunoblotting. Sequential sera from one individual who apparently underwent seroconversion according to the commercial assays were all positive by E32/E34 ELISA and immunoblotting. Thus, the ELISA with synthetic peptides is an extremely sensitive and specific test of antibody response to HIV and has not yet yielded a negative result with a Western blot (immunoblot)-confirmed antibody-positive serum.

AIDS-Related Complex↗
PubMed1987

Chondroitin sulfates used as adjuvants for antibody formation and as mitogens for B cells.

The effects of chondroitin sulfates (ChS) A and C on antibody formation in mice and chickens and on proliferation of murine B cells in vitro were determined. Simultaneous injection of ChS with sheep erythrocytes (SRBC) caused enhanced antibody production as measured by plaque-forming cells per spleen on day 5 after antigen and by serum agglutinin titers. ChS.C was more active than ChS.A and intravenous (i.v.) injection was far more effective, requiring 100-fold lower doses, than intraperitoneal (i.p.) injection. Responses of chickens could be enhanced by i.v., but not by i.p., injection of ChS.C with SRBC. Simultaneous injection of ChS.C with trinitrophenylated Ficoll had no effect, but injection of ChS.C 2 days after this antigen significantly increased the responses. Although ChS.C and ChS.A both caused proliferation of normal and athymic mouse spleen cells, the concentrations required for this effect in vitro were much higher than those needed for the in vivo effect. ChS.C caused only a slight increase in delayed hypersensitivity to a contact sensitizer.

Animals↗
PubMed1986

Use of an antibody to characterize and determine the role of the major Met-tRNAf deacylase from rabbit reticulocyte ribosomes.

Inhibition of polypeptide chain initiation in rabbit reticulocyte lysate by phosphorylation of eukaryotic initiation factor-2(alpha) results, secondarily, in the enzymatic deacylation of Met-tRNAf on the 48 S initiation complexes that accumulate. We have prepared an antibody to a highly purified preparation of the major Met-tRNAf deacylase activity on rabbit reticulocyte ribosomes, termed deacylase II. Antibody, but not similarly purified normal IgG, completely neutralizes the activity of Met-tRNAf deacylase II and has no effect on Met-tRNAf deacylase I, a separate, minor, reticulocyte activity with the same substrate specificity but very different physical and enzymatic properties, strongly suggesting that deacylase I and II are distinct proteins. We partially purified Met-tRNAf deacylase activities from rabbit liver, myocardium and bone marrow ribosomes and found them to be similar to each other and to reticulocyte deacylase I in their enzymatic properties and insensitivity to anti-deacylase II, suggesting that deacylase I may be a general form of this enzyme, present in many cells, while deacylase II may be induced specifically during erythroid differentiation. Addition of the antibody to reticulocyte lysate incubated in the absence of hemin or presence of hemin plus 0.1 microgram/ml poly(I X C) did not reverse the inhibition of protein synthesis but did reduce the rate of turnover/utilization of Met-tRNAf and increase the level of Met-tRNAf bound to 48 S initiation complexes, demonstrating that the deacylase does not directly inhibit protein synthesis under these conditions but does mediate the deacylation, loss, and thus greater than expected turnover of Met-tRNAf in the 48 S complexes that accumulate.

Acyltransferases↗
PubMed1986

Long-term plasma glucose normalization in experimental diabetic rats with macroencapsulated implants of benign human insulinomas.

Permselective tubular membranes (1 mm i.d.) were filled with fragments of nine freshly resected human insulinomas, closed at both ends, and implanted in the peritoneal cavity of 30 streptozocin-induced diabetic rats. In 14 animals, nonfasting plasma glucose (PG) and insulin levels were normalized by these immunoprotected transplants for up to 1 yr (PG from 520 +/- 12 to 142 +/- 3 mg/100 ml; insulin from 6 +/- 0.5 to 44 +/- 3 microU/ml). These animals showed the same weight gain after 12 mo of observation as 20 controls. The remaining 16 animals showed an incomplete or transient correction of their diabetes and survived 4-6 mo, versus less than 8 wk in untreated animals. Removal of the membrane-encapsulated insulin-secreting tissue from 8 successfully treated rats led to hyperglycemia and death within 10 days. Histology and electron microscopy of insulinoma tissue retrieved after long-term implantation showed functionally active endocrine cells and no evidence of graft rejection. In vitro perifusion gave similar results for encapsulated and nonencapsulated insulinoma tissue. The amount of insulin secreted was quite variable, and responsiveness of the insulinoma to changes in glucose concentration of the surrounding medium was observed in three out of the five tumors studied. These observations establish the effectiveness of immunoseparation by a synthetic membrane in a pancreatic xenograft model.

Adenoma, Islet Cell↗
PubMed1985

Transfer of experimental allergic neuritis with P2-reactive T-cell lines.

Experimental allergic neuritis (EAN) was induced in normal Lewis rats by systemic passive transfer of T-cell lines responding to P2 protein. These cells had predominantly helper phenotype and could induce EAN within 7 days following adoptive transfer. There was no anti-P2 antibody response in the recipients of the P2-reactive cells recovered from donors with high anti-P2 antibody levels. This study provides direct evidence that T cells are important for the induction of EAN. Furthermore, there was no evidence of a pathogenic role for anti-P2 antibody in passive EAN.

Animals↗
PubMed1985

Syngeneic mixed lymphocyte reactions to murine Fc receptor-bearing, nonadherent low density lymph node cells and epidermal Langerhans cells.

Both Langerhans cells from BALB/c mouse epidermis and nonadherent, low density (LD) cells, obtained from collagenase-treated minced lymph node, are stimulatory for isolated T cells in syngeneic mixed lymphocyte reaction (SMLR). The method of preparation of LD cells influences whether Fc receptor (FcR) can be detected on them. Fc receptors on nonadherent LD lymph node cells can be detected only if the same procedure is employed as that for Langerhans cell isolation, i.e., Ig-free bovine albumin must be used during gradient centrifugation and EA rosetting must be done overnight at 4 degrees C. Thus, both FcR+ and FcR- LD lymph node cells, as well as FcR+ Langerhans cells, stimulate SMLR. Although Ig+ cells in the LD fraction also stimulate the SMLR, their removal does not affect the stimulating capacity of the LD lymph node fraction.

Animals↗
PubMed1985

Platelet alpha-2-adrenergic dysfunction in negative symptom schizophrenia: a preliminary study.

The specific binding to platelet membranes (Bmax) of 3H-clonidine, an alpha-2 agonist, and 3H-yohimbine, an alpha-2 antagonist, was measured in nine drug-free male schizophrenic patients and repeated after 2 weeks of chlorpromazine (CPZ) treatment. Patients with a lower pretreatment Bmax for 3H-clonidine showed a significantly smaller change in Bmax after treatment, less improvement in their clinical state, as indicated by the change in the Global Assessment Scale (GAS), and a lower posttreatment GAS. Also, they had a significantly higher score for negative symptoms on the Affect Rating Scale both before and after treatment. These findings suggest that schizophrenic patients with relatively subsensitive platelet alpha-2-adrenergic receptors, as measured by 3H-clonidine binding, tend to have more negative symptoms and a diminished alpha receptor binding response and diminished clinical response to CPZ. There were no clinical correlations to 3H-yohimbine binding.

Blood Platelets↗