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Biomedical subjects

B Jones

Publications and source records attributed to B Jones.

At least 541 records · Page 30Linked to original sources
PubMed1983

Computed tomography and appendiceal abscess: special applicability in the elderly.

Five cases are presented in which appendiceal abscesses were demonstrated by computed tomography (CT) and confirmed at surgery. In another, a feces-filled cecum led to a false positive diagnosis of appendiceal abscess, and this is included as an instructive case. Three of the patients were elderly, with an atypical presentation; in these, CT was especially important in clarifying the diagnosis by including appendiceal abscess in the differential diagnosis of pelvic pathology.

Abscess↗
PubMed1983

Pharmacokinetics of metronidazole in patients undergoing peritoneal dialysis.

After a single 500-mg intravenous dose of metronidazole, plasma and dialysate levels were measured over a 7.5-h period in five patients undergoing peritoneal dialysis for terminal renal failure. Approximately 10% of this dose was removed by dialysis during that period, and therapeutic levels were maintained in plasma. No routine adjustment in the dosage of metronidazole appears necessary in patients undergoing peritoneal dialysis.

Adult↗
PubMed1983

Intracellular pH in intact rat renal cortex estimated with [14C]-5,5-dimethyl-2,4-oxazolidinedione.

The distribution of [14C]-5,5-dimethyl-2,4-oxazolidinedione ([14C]-DMO) was measured in intact rat renal cortex using 22Na+ to estimate extracellular fluid volume. Results of two different methods to obtain tissue were compared, a cortical slice technique and a whole kidney frozen technique. In normal animals with a mean blood pH of 7.41 +/- 0.006 (SEM) the cortical slice method measured an intracellular pH of 6.97 +/- 0.03 (SEM). Corrections are described which can be used to compensate for varying volumes of tubular fluid in the slice and for differing concentrations of intracellular sodium. Using reasonable estimates for tubular fluid volume and intracellular sodium these corrections increase the value of intracellular pH to about 7.20. The results of the study indicate that the cortical slice [14C]-DMO method provides a satisfactory technique to obtain baseline values for intracellular pH in intact renal cortex, which can be used to detect changes in intracellular pH produced by experimental manipulations.

Acid-Base Equilibrium↗
PubMed1983

Influence of alterations in acid-base conditions on intracellular pH of intact renal cortex.

Intracellular pH (pHI) of intact rat renal cortex was estimated using [14C]-5,5-dimethyl-2,4-oxazolidinedione and 22Na+ under conditions of metabolic acidosis and alkalosis, potassium depletion and carbonic anhydrase inhibition. In metabolic acidosis and alkalosis, pHI and bicarbonate concentration changed in the same direction as occurred in plasma. In potassium depletion, systemic acid-base balance was unaltered but a marked intracellular acidosis developed. Carbonic anhydrase inhibition with acetazolamide was associated with an extracellular respiratory acidosis and a rise in intracellular bicarbonate concentration. Another carbonic anhydrase inhibitor, benzolamide, caused no change in systemic acid-base state but produced a decrease in intracellular bicarbonate concentration. When appropriate corrections were made for predicted change in tubular fluid bicarbonate and for intracellular sodium, modification in the absolute values of the above changes occurred but the directions of the changes in pHI and bicarbonate concentration were unaltered.

Acid-Base Equilibrium↗
PubMed1983

A cloned, antigen-specific, Ia-restricted Lyt-1+,2- T cell with suppressive activity.

The correlation between cell surface antigen phenotype and function is one of the cornerstones of modern cellular and clinical immunology. It is based on the collective experience of many investigators examining populations of T cells. The availability of cloned lines of T cells now allows us to ask whether all cells sharing cell surface antigen phenotype are functionally equivalent. We have examined a large number of antigen-specific, self-Ia recognizing, cloned Lyt-1+,2- T cell lines for their ability to help B cells proliferate and secrete antibody in response to antigen. All of these lines induced antigen-specific, Ia-restricted B cell proliferation. One line did not induce antibody secretion. This line, indeed suppressed the plaque-forming cell response of B cells helped by any of the other cloned T cell lines tested. Suppression in this system had all the characteristics of classical T cell help, apart from the ultimate outcome. That is, the suppressor cell acted upon the B cell in a manner that was antigen-specific, Ia-restricted, and required hapten-carrier linkage. We interpret our results as supporting the basic paradigm of an association of cell surface antigen phenotype with function, with an important proviso. Not all Ly1, Ia-restricted T cells may be capable of helper function, and some in fact may be suppressive. Experimental conditions favoring the generation of such cells, or disease states in which such cells reside within the Ly1 or T4+ subset, may give rise to disparities between phenotype and function similar to that observed here at the clonal level.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

Villous hypertrophy of the small bowel in a patient with glucagonoma.

Mucosal thickening in the small bowel was seen on computed tomography (CT) in a patient with a pancreatic glucagonoma. A small bowel series demonstrated multiple fine filling defects throughout both jejunum and ileum associated with moderate fold thickening and prolonged transit time. Villous hypertrophy was indeed identified in a resected segment of jejunum. Elevated blood levels of enteroglucagon have previously been associated with small intestinal villous hypertrophy. Careful scrutiny of the bowel pattern on CT scans may suggest abnormalities which may then be confirmed by conventional barium studies. Such observations may change the evaluation of a clinical problem.

Adenoma, Islet Cell↗
PubMed1983

Stathmokinetic measurement of tumour cell proliferation in relation to vascular proximity.

In this study the metaphase-arrest method with vincristine (VCR) was used, in a transplanted C3H mouse mammary tumour, to study cell proliferation relative to distance from a blood vessel. The metaphase-arrest method has a number of advantages over methods involving [3H]TdR labelling for such a study. The cell birth rate (kB) was shown to be inversely related to distance from a capillary in corded areas of tumour. Penetration of VCR, even into perinecrotic areas of tumour, appeared to be sufficient to achieve effective metaphase arrest.

Adenocarcinoma↗
PubMed1982

Vindesine: a phase II study in childhood malignancies-a report for cancer and leukemia group B.

Vindesine, a semisynthetic derivative of vinblastine sulfate, was tested for antitumor activity and clinical toxicity in 36 children. The drug was administered to the initial 13 patients entered into the study a 2 mg/m2/day for five days by IV bolus. Because of severe neurotoxicity and life-threatening gastrointestinal toxicity, the regimen in 23 patients was modified to 4mg/m2 IV infusion over four hours, weekly. This latter regimen was well tolerated, with acceptable gastrointestinal, hematological, and neurotoxicity. One child with acute lymphocytic leukemia resistant to vincristine had a transient M1 remission bone marrow. Improvement or stable disease was noted in one patient each with Ewing's sarcoma, neuroblastoma, and Hodgkin's disease.

Adolescent↗
PubMed1982

MHC recognition by clones of Mls specific T-lymphocytes.

To test whether Mls determinants like other non-MHC or nominal antigens, are recognized by T-cells in association with H-2 determinants, the in vitro proliferative responses of T-cell lines and clones were studied. Lines and clones were prepared by soft agar cloning (B10.BR X BALB/c)F1 (H-2k/H-2d Mlsb/Mlsb) t-cells responding in a primary MLR to AKD2F1 (H-2k/H-2d, Mlsa/Mlsa) stimulator cells. All the T-cell clones obtained could respond equally well in a proliferative assay to the Mlsa determinant in association with the H-2 haplotype of either parent, i.e., DBA/2 (H-2d, Mls), and AKR (H-2K, Mlsa) both stimulated equally well. When the T-cell lines and clones were screened against stimulators from recombinant inbred (RI) strains, it became apparent that strains exhibiting the H-2b, Mlsa genotype stimulated poorly or not at all. This shows that the T-cell response to Mlsa involves MHC recognition, and raises the possibility that the response to Mlsa can involve recognition of H-2 specificities shared between the H-2k and H-2d haplotypes.

Animals↗
PubMed1982

Cell kinetic response of an experimental tumour to irradiation. Use of the stathmokinetic method.

The cell kinetic perturbations following irradiation (20 Gy) were studied by combining the metaphase arrest method using vincristine with histological indices of cell death. The metaphase arrest method yielded remarkably constant values of rate of entry into mitosis (rM) of around 24 new cells/1,000 cells/hour during a 7 day period in which there was no tumour growth. The time course of cell death as indicated by changes in the pyknotic index during this period may reflect the processes of reoxygenation and repopulation known to influence the results of fractionated radiotherapy.

Adenocarcinoma↗