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B Jones

Publications and source records attributed to B Jones.

At least 505 records · Page 28Linked to original sources
PubMed1984

Characteristics of tyrosinate fluorescence emission in alpha- and beta-purothionins.

The CD, absorption, and fluorescence spectra and fluorescence lifetimes of three highly homologous, basic cytotoxic proteins isolated from wheat (alpha 1-, alpha 2-, and beta-purothionins) and a moderately homologous protein isolated from Crambe abyssinica (crambin) have been measured. The purothionins each contain a single tyrosine, while crambin has two tyrosine residues. At neutral pH in buffered solution or in water, beta-purothionin showed a single fluorescence emission peak maximal at 345 nm; alpha 1- and alpha 2-purothionins gave a double-humped emission (lambda max 308 and 345 nm), while crambin emitted only at 303 nm. Under acid pH conditions (less than pH 3) or when denatured in 6 M guanidine hydrochloride, the spectra of the alpha- and beta-purothionins showed predominantly the 303-nm emission (tau = 3.1 ns) while at pH greater than 10.0 only the 345-nm emission was evinced by all three proteins. Crambin showed typical tyrosine emission in the pH range 3-9 and weak tyrosinate fluorescence at pH greater than 10.5. From these features, and from the absorption and CD spectra, we infer that the 345-nm fluorescence emission of either alpha 1- or beta-purothionin is from tyrosinate moieties. The purothionin emission spectra appear to be generated by excited-state proton transfer rather than from tyrosinate species in the ground state.

Antimicrobial Cationic Peptides↗
PubMed1984

In vivo determination of efficacy of pyrazoloquinolinones at the benzodiazepine receptor.

The pyrazoloquinolinones CGS 9896, CGS 9895 and CGS 8216 potently displace the benzodiazepines from their CNS binding site in vitro but have been reported to display agonist, partial agonist and antagonist activity respectively in a number of in vivo tests in rats. We found CGS 9896 to have only weak antipentylenetetrazole activity in mice at doses which produced near maximal displacement of [3H]flunitrazepam in vivo and were not able to detect any antipentylenetetrazole activity of CGS 9895. However, CGS 9895 blocked the anticonvulsant effect of diazepam at doses closely related to those which inhibited the in vivo binding of [3H]flunitrazepam and CGS 9896 also showed some reversal of the antipentylenetetrazole action of diazepam. This is consistent with the notion that CGS 9896 is a partial agonist and CGS 9895 an antagonist at the benzodiazepine receptor.

Animals↗
PubMed1984

Amino acid sequence and secondary structural analysis of the corn inhibitor of trypsin and activated Hageman Factor.

The amino acid sequence of a corn inhibitor for trypsin and activated Hageman Factor (Factor XIIa) was determined by automated Edman degradation from the intact inhibitor and two fragments generated by specific cleavage of the inhibitor. The 112-residue sequence is unique at each position except 91, where both Ala and Glu were found. The structural heterogeneity suggests the occurrence of two genes (possibly allelic) for the inhibitor. Based on analysis of fragments produced by the interaction of the inhibitor with trypsin-agarose, the reactive site peptide bond is identified as Arg 36-Leu 37. There is no strong similarity between the sequence of the corn inhibitor and the sequences published for other serine protease inhibitors. Thus, the corn inhibitor represents a new family of protease inhibitors. Circular dichroism measurements and a theoretical prediction of secondary structure indicate that the inhibitor has helix and beta sheet contents of approximately 40 and 20%, respectively.

Amino Acid Sequence↗
PubMed1984

How drugs act.

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Absorption↗
PubMed1984

The role of B cell surface Ia antigen recognition by T cells in B cell triggering. Analysis of the interaction of cloned helper T cells with normal B cells in differing states of activation and with B cells expressing the xid defect.

Two discrete mechanisms of T-B cell collaboration appear to exist. In cognate recognition, B cell triggering results from a direct recognition of antigen and MHC determinants at the B cell surface. Alternatively, B cells can be triggered by transstimulation, in which the Th cell is activated by an antigen-presenting cell to produce soluble factors which in turn trigger the B cell. This report addresses the question of whether antigen recognition at the B cell surface in association with Ia determinants delivers a signal to the B cell, which is qualitatively different from the signals delivered by the soluble mediators released by the activated Th cell. Previous reports from a number of laboratories suggest that cognate recognition is obligatory for the triggering of small resting B cells and B cells of the Lyb-5- phenotype, whereas enlarged B cell blasts and the Lyb-5+ subset can be triggered solely by soluble mediators. Contrary to these findings, the experiments described here indicate that B cells isolated in different states of activation from normal spleens on the basis of their buoyant density in Percoll density gradients, or unfractionated B cells from mice differing genetically due to the xid defect [Lyb-5- B cells from (CBA/N X BALB/c)F1 male mice], do not discriminate between the two modes of Th cell function. In both stimulation modes, the high density B cells, and the B cells from xid mice made very poor immunoglobulin secretory responses measured in terms of reverse plaque formation on protein A-coupled erythrocytes. When the responses of different density fractions of B cells were compared under conditions where stimulation occurred either directly or indirectly via transstimulation, the following hierarchy of responsiveness in both the proliferative and plaque-forming cell (PFC) responses was observed in the density fractions 60% greater than 65% greater than 70% greater than 75%. The hierarchy was the same in both modes of interaction and the deficiency of the high density, small B cells was far more marked in the PFC assay than in the proliferative assay. We conclude that the initial proliferative response of the resting B cell can be triggered comparably in vitro under conditions of direct or transstimulation. Thus, recognition of B cell surface Ia by Th cells is not obligatory for B cell activation and does not transfer an essential transmembrane signal to the B cell.

Animals↗
PubMed1984

Computed tomographic diagnosis of radiation ileitis.

Two patients were studied by CT after resection of colon carcinoma followed by abdominal radiation therapy. Based upon the findings of a localized, mass-like confluence of shortened loops of bowel with thickening of bowel wall, adherence of adjoining loops, thickening of the adjacent mesentery, and increased density of mesenteric fat the patients were considered to have radiation ileitis. Recurrent tumor was excluded by autopsy and confirmed by a 1-year asymptomatic follow-up period.

Adenocarcinoma↗
PubMed1984

Scintigraphic peritoneography in advanced ovarian malignancies: its value for chemotherapeutic distribution studies.

It is important to be aware of the position of the transabdominal infusion catheter and of the expected distribution of the chemotherapeutic agent, prior to the administration of intraperitoneal chemotherapeutic agents for metastatic tumour. The intraperitoneal introduction of technetium-99m labelled human serum albumin provides a means of studying fluid distribution, as well as identifying the catheter position. The technique used in this examination, the expected normal pattern of distribution and various pathological findings and pitfalls of the peritoneal scan are discussed on the basis of results in 10 patients, in whom 24 intraperitoneal scintigraphic studies were done. In one of these scans there was inappropriate filling of the lesser sac. In another scan the tip appeared to lie within the lumen of the small bowel. In two other patients inappropriate filling of the large bowel was seen. Only one scan showed a total widespread distribution of the scintigraphic agent throughout the abdominal cavity. In 16 other scans the spread was satisfactory. In three scans certain parts of the abdominal cavity did not show any activity at all. In these last scans computed tomography findings could explain why there was a poor peritoneal distribution of the scintigraphic agent.

Adult↗
PubMed1984

CT demonstration of colovesical fistulae secondary to diverticulitis.

Colovesical fistula, a not infrequent complication of diverticulitis, can be difficult to demonstrate by commonly used diagnostic imaging modalities. We present four cases in which computed tomography was used to detect the presence of such a fistula. Computed tomography readily detected air within the bladder earlier and without equivocation when compared with other imaging techniques. It was useful also in the assessment of the extent and the degree of pericolonic inflammation, thus playing an important role in preoperative surgical planning and postoperative follow-up.

Aged↗
PubMed1984

Cholecystitis associated with myelomatosis.

A case of myeloma presenting as acute cholecystitis unresponsive to conventional management is reported. The impairment of the immunological response is a well-known aspect of myeloma, although this usually takes the form of recurrent respiratory infections. It is unusual for acute on chronic cholecystitis, a predominantly Gram-negative infection, to present in this way.

Adult↗
PubMed1984

Open trial of S-adenosylmethionine for treatment of depression.

Nine depressed inpatients completed trials with S-adenosylmethionine. Seven showed improvement or remission of their symptoms. As in European studies, no side effects were seen except the apparent induction of mania in two patients with bipolar disorder.

Adult↗
PubMed1984

Toxic deaths in the Second National Wilms' Tumor Study.

There were 122 deaths among 803 children registered, randomized, and followed in the second National Wilms' Tumor Study; 17 occurred in children apparently free of disease and were attributable to causes other than tumor progression. Seven deaths were attributed to infection during periods of drug-induced leukopenia; four were due to liver failure; and one each was attributable to radiation pneumonopathy, intestinal obstruction, renal failure, myocardial disease, and encephalopathy. The cause of one death was unexplained. Of particular concern were four (of 47) infants under one year of age with group I or II disease who had toxic deaths. Subsequent to these experiences the doses of all chemotherapeutic agents were reduced by 50% for infants under one year of age. No deaths from toxicity were observed thereafter in infants. An analysis of the therapeutic effect of this dose reduction showed three of 47 relapsed on full dose and five of 54 on half dose. The difference is not statistically significant. This report is a further demonstration of the potentially serious vulnerability of infants to standard doses of anticancer drugs even when they are calculated on a per kilogram basis.

Age Factors↗