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Biomedical subjects

S Jones

Publications and source records attributed to S Jones.

At least 541 records · Page 30Linked to original sources
PubMed1986

Double isotype production by a neoplastic B cell line. I. Cellular and biochemical characterization of a variant of BCL1 that expresses and secretes both IgM and IgG1.

We have subcloned the in vitro-adapted murine B cell leukemia, BCL1.B1, to obtain a variant that expresses both IgM and IgG1. By fluorescence analysis, radioiodination, and immunoprecipitation of cell surface Ig, and by RIA of medium from limiting dilution cultures, we have shown that: (a) all the cells express and secrete both isotypes. The heavy chains of both IgG1 and IgM have the apparent molecular weights of membrane mu and gamma 1 chains; (b) both isotypes bear the same idiotype as determined by immunoprecipitation with antiidiotypic antibody, and both use the same VDJ rearrangement as shown by Southern blotting; and (c) the cells express the membrane and secreted forms of mRNA for both mu and gamma 1 but not gamma 2b or gamma 3. Taken together, the data suggest that all the cells are synthesizing, expressing on their surface, and secreting two isotypes that use the same VDJ rearrangement in the DNA and express the same serologically-defined idiotype. The molecular basis responsible for the production of the two isotypes in a single cell is the subject of the accompanying paper.

Animals↗
PubMed1986

Isolation and characterization of cDNA clones for the 35-kDa pulmonary surfactant-associated protein.

A group of 35,000-dalton sialoglycoproteins is the major non-serum protein component of pulmonary surfactant. Tryptic fragments of these proteins were sequenced, and oligonucleotide probes were synthesized based on the amino acid sequences. A human lung cDNA library was then screened using the oligonucleotide probes, and clones coding for these proteins were identified and characterized. By in vitro transcription-translation experiments we have associated individual clones with particular proteins. The data suggest that co-translational modifications of two primary translation products account for many of the isoforms observed by two-dimensional gel electrophoresis in the precursors of 35,000-dalton sialoglycoproteins.

Amino Acid Sequence↗
PubMed1986

Use of flecainide acetate for refractory junctional tachycardias in children with the Wolff-Parkinson-White syndrome.

The response of sustained supraventricular tachycardia to intravenous and oral flecainide acetate was investigated in 5 children, aged 5.5 to 11.5 years, who had tachycardias associated with Wolff-Parkinson-White syndrome. All children had failed to respond to at least 2 conventional agents. The effect of flecainide was studied using intracardiac techniques. Intravenous flecainide terminated tachycardia in all 5 patients. After drug infusion, slow, sustained tachycardia could be initiated in 1 patient. With oral treatment, slow, sustained tachycardia was started in 2 children and nonsustained in 2. One child had no inducible tachycardias. In 4 of 5 patients, long-term treatment has reduced the frequency of episodes and the drug is well tolerated. Thus, flecainide may be used to terminate and suppress junctional tachycardias in children who have failed to respond to conventional therapy.

Administration, Oral↗
PubMed1986

Azacytidine induces reversion of thymidine kinase deficiency in Friend erythroleukemia cells.

Cells of the Friend erythroleukemia cell line show a high frequency of variants which have lost thymidine kinase activity. We have exposed a thymidine kinase-deficient clone of this cell line to a series of concentrations of azacytidine and found a dose-dependent induction of thymidine kinase-positive revertants. Maximum reversion occurred with 0.9 micrograms/ml azacytidine where the frequency of revertants amongst survivors was increased by a factor of 10(6) compared to that of control cultures. Revertants were found to have varying levels of thymidine kinase activity. We conclude that DNA methylation of one or both alleles of the thymidine kinase gene is largely responsible for the instability of this gene in Friend erythroleukemia cells.

Alleles↗
PubMed1986

An experimental study of hydrophilic plastics for urological use.

Hydrophilic graft copolymers of polyethylene vinyl acetate (PEVA) were extruded into tubular form. These materials increase both external and internal diameters by 60% on contact with water. The tubes were used as ureteric stents in an experimental study and were superior to silicone stents of the same calibre in the limitation of urinary extravasation. Histological, cytotoxic and electron microscopic studies showed that PEVA is a biocompatible material suitable for clinical use in urology.

Animals↗
PubMed1986

Cognitive style in depression.

A revised version of the CST was validated by comparing depressed patients with anxious patients, recovered depressed and anxious patients and normal controls. Other measures included three severity of illness scales (the Beck Depression Inventory, the Hamilton Rating Scale for Depression and the state version of the State-Trait Anxiety Inventory) and three well-established cognitive scales (the Automatic Thought Questionnaire, the Hopelessness Scale and the Dysfunctional Attitude Scale). Depressed patients were differentiated from normal controls on all subscales of the CST and the three other cognitive scales. They were similarly differentiated from recovered depressed patients, except for negative interpretations relating to the self when age was covaried. Anxious patients were significantly differentiated from depressed patients on total level of negative thinking, negative interpretations of unpleasant events and negative thinking relating to the world when age was covaried. Hopelessness and dysfunctional attitudes also differentiated depressed and anxious patients. Face validity and concurrent validity for the new scale are provided. The specificity of negative thinking to depression and the possibility of a vulnerable cognitive style are discussed.

Adolescent↗
PubMed1986

Enterotoxin synthesis by nonsporulating cultures of Clostridium perfringens.

Chemostat-cultured Clostridium perfringens ATCC 3624 and NCTC 10240, and a nonsporulating mutant strain, 8-5, produced enterotoxin in the absence of sporulation when cultured in a chemically defined medium at a 0.084-h-1 dilution rate at 37 degrees C. The enterotoxin was detected by serological and biological assays. Examination of the chemostat cultures by electron microscopy did not reveal sporulation at any stage. The culture maintained enterotoxigenicity throughout cultivation in a continuous system. The enterotoxin was detected in batch cultures of each strain cultivated in fluid thioglycolate medium and a chemically defined medium. No heat-resistant or light-refractile spores were detected in batch cultures during the exponential growth.

Clostridium perfringens↗
PubMed1986

Renal nerve activity and renal function during environmental stress in DOCA-NaCl rats.

The effects of a stressful environmental stimulus (air stress) on mean arterial pressure, heart rate, renal sympathetic nerve activity, and renal function were studied in conscious deoxycorticosterone acetate-sodium chloride (DOCA-NaCl) hypertensive rats, sham DOCA-NaCl normotensive rats, and DOCA-NaCl rats with renal denervation. In conscious DOCA-NaCl hypertensive rats, air stress decreased urine flow rate [36% from 17.9 +/- 3.0 microliter X min-1 X 100 g body wt-1 (BW)], urinary sodium excretion (39% from 3.1 +/- 0.5 microeq X min-1 X 100 g BW-1), fractional water excretion (24% from 4.72 +/- 1.00%), and fractional sodium excretion (28% from 5.72 +/- 1.08%) and increased renal sympathetic nerve activity (94% from 8.3 +/- 0.6 integrator resets/min), but no changes occurred in glomerular filtration rate (-15% from 0.40 +/- 0.06 ml X min-1 X 100 g BW-1) or effective renal plasma flow (-7% from 2.50 +/- 0.53 ml X min-1 X 100 g BW-1). Air stress had no effect on these measures in conscious sham DOCA-NaCl normotensive rats or DOCA-NaCl rats with renal denervation. Mean arterial pressure and heart rate were unaffected by air stress in these three groups. Renal denervation lowered base-line mean arterial pressure in DOCA-NaCl rats. Thus DOCA-NaCl hypertensive rats respond to environmental stress with increased renal sympathetic nerve activity and, consequently, antidiuresis and antinatriuresis.

Air↗
PubMed1986

Hypothalamic beta 2-adrenoceptor control of renal sympathetic nerve activity and urinary sodium excretion in conscious, spontaneously hypertensive rats.

The contributions of beta 1-, B2-, and alpha 2-adrenoceptors in the posterior hypothalamus to the increased renal sympathetic nerve activity and decreased urinary sodium excretion resulting from environmental stress (air jet) in conscious spontaneously hypertensive rats were examined. Air stress increased mean arterial pressure and renal sympathetic nerve activity (54% from 7.0 +/- 0.7 integrator resets/min), and decreased urinary sodium excretion (44% from 2.7 +/- 0.4 microEq/min per 100 g body weight). After bilateral injection of ICI 118,551 (beta 2-adrenoceptor antagonist) into the posterior hypothalamus of the same spontaneously hypertensive rats, air stress had no effect on renal sympathetic nerve activity (8% from 4.8 +/- 0.7 integrator resets/min) or urinary sodium excretion (2% from 5.2 +/- 0.8 microEq/min per 100 g body weight), but still increased mean arterial pressure. Bilateral injection of isoproterenolol (beta-adrenoceptor agonist) into the posterior hypothalamus enhanced the renal sympathetic nerve activity and urinary sodium excretion (but not mean arterial pressure) responses to air stress. Air stress had no effect on renal sympathetic nerve activity or urinary sodium excretion when ICI 118,551 was given into the posterior hypothalamus before isoproterenol. Atenolol (beta 1-adrenoceptor antagonist) had no effect on the renal responses to air stress when given alone or before isoproterenol. Similarly, ICI 118,551 administered into the lateral hypothalamus or lateral cerebral ventricle, or guanabenz (alpha 2-adrenoceptor agonist) given into the posterior hypothalamus, had no effects on the renal or mean arterial pressure responses to air stress. Thus, beta 2-adrenoceptors in the posterior hypothalamus mediate the increased renal sympathetic nerve activity and antinatriuresis resulting from environmental stress in conscious spontaneous hypertensive rats.

Air↗
PubMed1986

Immunologic complexity of lymphoblastic lymphoma.

Twelve patients with a histologic diagnosis of lymphoblastic lymphoma (LBL) were studied immunologically using the methodologic refinement of comparative serial section immunochemistry. By this means, we demonstrate complex LBL phenotypic profiles, revealing 3 major immunologic subtypes: immature T cell, 7 cases; intermediate or mature T cell, 3 cases; immature B cell (pre-pre-B), 2 cases. This phenotypic diversity challenges the basic belief that all LBL are the same. Our immature T-cell cases with frequent simultaneous Leu 2/3/6/9/CALLA/Tdt expression correspond to cortical thymic phenotypes; our mature T-cell phenotypes with Leu 9/la expression and absent L6/Tdt correspond either to medullary thymocytes or post-thymic T cells; our pre-pre-B phenotypes with simultaneous Tdt/CALLA/B4 expression correspond to common acute lymphocytic leukemia (ALL) phenotypes. Mature T-LBL phenotypes are similar to "novel" peripheral T-cell lymphoma phenotypes. Scant or absent Tdt expression in mature LBL is not an isolated antigenic change but a complete phenotypic profile difference from immature T-LBL. The major T- and B-cell phenotypes of LBL might have therapeutic significance. Treatment among LBL phenotypes may need to vary as with acute lymphocytic leukemia phenotypes. Further study is needed; in the meantime, comparative serial section immunotyping promises substantial utility in revealing the immunologic complexity of the lymphomas.

Adolescent↗
PubMed1986

Retardation of tumor growth in mice caused by radiation-induced injury of tumor bed stroma: dependency on tumor type.

Dependency on tumor type of tumor growth retardation caused by the radiation-induced damage of tumor bed stroma, a phenomenon known as the tumor bed effect (TBE), was investigated using two mammary carcinomas designated MCA-4 and MCA-K and two fibrosarcomas designated FSA and NFSA, all syngeneic to C3Hf/Kam mice. Inoculations of tumor cells were given s.c. into the right hind thighs of mice either treated or not treated 1 day earlier with graded doses of gamma-rays; tumor latency and growth rate were determined. Tumor latency was prolonged and tumor growth was retarded, but the magnitude of these two features of TBE greatly depended on radiation dose and tumor type. TBE began to appear at doses of 5-10 Gy and then sharply increased as the dose of radiation was increased up to between 20 and 30 Gy, at which point a plateau was achieved. TBE was also significant after 40 and 60 Gy total dose given in daily fractions of 2 Gy 5 times per week, a schedule commonly used in radiotherapy treatment of cancer patients. Carcinomas exhibited more pronounced TBE than fibrosarcomas, with NFSA showing only minimal TBE. Radiation-inactivated MCA-4 and FSA cells admixed with viable MCA-4 cells reduced tumor latency, but not the tumor growth delay, of resulting MCA-4 tumors in preirradiated legs. In contrast, admixture of irradiated NFSA and viable MCA-4 cells abolished growth delay but did not influence tumor latency of the TBE phenomenon. Thus the type of a tumor growing in the irradiated tissue is a very important factor that determines the expression of TBE.

Animals↗
PubMed1985

Reutilization of surfactant phosphatidylcholine in adult rabbits.

32P-saturated phosphatidylcholine was added to [3H]choline-labeled natural surfactant and the mixture was injected intratracheally into 87 adult rabbits. The rabbits were also given [14C]palmitate intravenously at the same time. Rabbits were killed in groups from 10 min to 72 h after injection. In each rabbit we measured the total recovered [3H]phosphatidylcholine (PC) in the alveolar wash, the ratio of [3H]PC to [32P]PC in the alveolar wash, and the specific activity of [14C]PC in the alveolar wash and lamellar bodies. Values were averaged for all rabbits killed at the same times and smooth curves were fit to the data by computer. From the intravenous [14C]palmitate data we calculated a turnover time for alveolar PC of 6.0 h. From the intratracheal labeling data, we calculated a turnover time for alveolar PC of 5.7 h and determined that alveolar PC was reutilized at an efficiency of only 23%. We also concluded that this reutilization occurred as intact molecules.

Animals↗