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Biomedical subjects

J F Thompson

Publications and source records attributed to J F Thompson.

At least 289 records · Page 16Linked to original sources
PubMed1986

Cyclosporin and renal graft histology.

The histology of renal allografts was compared in a series of 107 biopsies from patients receiving cyclosporin and 126 biopsies from patients receiving azathioprine and prednisolone. Patients receiving cyclosporin were converted to azathioprine and prednisolone 90 days after transplantation. Biopsies were taken routinely at 7, 21, 90, and 365 days, irrespective of clinical graft function and were examined "blind" by two independent observers. Interstitial haemorrhage was more common in patients treated with azathioprine and prednisolone corresponding with their poorer graft survival. Analysis of glomerular, tubular, vascular, and interstitial changes showed no other important differences between the two groups despite clinical evidence of reversible cyclosporin nephrotoxicity. Quantitation of interstitial fibrosis in 90 day biopsies showed it to be equal in prevalence after treatment with azathioprine and prednisolone and cyclosporin. It was preceded by diffuse interstitial cellular infiltration, a common finding in early biopsies. Diffuse cellular infiltrates were generally associated with higher serum creatinine concentrations and, if persistent, a poorer graft prognosis than focal infiltrates, but they were not always associated with renal dysfunction.

Azathioprine↗
PubMed1986

Nonocclusive chronic vascular catheterization of conscious unrestrained baboons.

A surgical technique is described for chronic arterial and venous catheterization of unrestrained adult baboons. Vascular access was achieved through a small (5 cm) abdominal incision and an extraperitoneal approach to the iliac vessels, which minimizes postoperative morbidity, discomfort, and restriction of movement. The method permits secure but nonocclusive catheterization, confirmed by angiography. Catheters were removed without further surgery, leaving the baboons intact for reuse. Catheters placed in the distal common or proximal external iliac vessels were all patent when removed at 46-61 days. The results demonstrate arterial pressure, pulse rates, drug administration, blood sampling, and plasma volume measurement as examples of the technique's application in conscious unrestrained baboons.

Animals↗
PubMed1985

Control of directionality in lambda site specific recombination.

The simple relation between the substrates and products of site-specific recombination raises questions about the control of directionality often observed in this class of DNA transactions. For bacteriophage lambda, viral integration and excision proceed by discrete pathways, and DNA substrates with the intrinsic property of recombining in only one direction can be constructed. These pathways display an asymmetric reliance on a complex array of protein binding sites, and they respond differently to changes in the concentrations of the relevant proteins. The Escherichia coli protein integration host factor (IHF) differentially affects integrative and excisive recombination, thereby influencing directionality. A four- to eightfold increase in intracellular IHF coincides with the transition from exponential to stationary phase; this provides a mechanism for growth phase-dependent regulation of recombination that makes the cellular physiology an intrinsic part of the recombination reaction.

Bacterial Proteins↗
PubMed1984

Control of hypertension after renal transplantation by embolisation of host kidneys.

A percutaneous embolisation technique was used for host kidney ablation in 13 patients with renal allografts and hypertension. Markedly improved blood pressure control was achieved in 9 of them, and morbidity was minimal. All patients have been followed from 12 to 25 months. Embolisation of the host kidneys appears to be a simple, effective, and less hazardous alternative to surgery in the treatment of drug-resistant hypertension after renal transplantation in some patients.

Adult↗
PubMed1984

Effects of exogenous methionine on storage protein composition of soybean cotyledons cultured in vitro.

Supplemental methionine in a complete culture medium increased the methionine content of the protein fraction of cultured soybean (Glycine max L. Merrill) cotyledons (Thompson, Madison, Muenster 1981 Phytochemistry 20: 941-945). To explain the observed increase in protein methionine, we have measured the amounts and subunit compositions of 7S and 11S storage proteins and determined the amino acid compositions of the three major protein fractions (2-5S, 7S, 11S) of seeds developed on plants and of cultured cotyledons grown in the presence or absence of supplemental l-methionine. Development of cultured cotyledons was representative of development of seeds on plants. The ratios of 11S to 7S proteins, the subunit contents, and amino acid compositions of their storage protein fractions were similar, but not identical. Supplemental methionine increased the mole percent methionine in each of the three protein fractions of cultured cotyledons and changed the amounts of several other amino acids. Supplemental methionine inhibited expression of the 7S beta-subunit gene. Concomitant with the absence of the beta-subunit, which contains no methionine, was an increase in the ratio of 11S to 7S proteins, and an increase in the methionine content of the subunits composing these fractions. Inhibition of beta-subunit gene expression by methionine in cultured cotyledons provides a reproducible, easily controlled system for the study of eucaryotic gene expression.

Journal Article↗
PubMed1984

Storage Protein Composition of Soybean Cotyledons Grown In Vitro in Media of Various Sulfate Concentrations in the Presence and Absence of Exogenous l-Methionine.

Immature soybean (Glycine max L. Merrill cv Provar) cotyledons were grown aseptically for 6 days in complete culture medium with zero, deficient (17 micromolar), sufficient (1.5 millimolar), or supraoptimal (7.5 millimolar) levels of sulfate. Some cotyledons at each sulfate concentration were supplemented with l-methionine. No sulfate or 17 micromolar sulfate were inadequate for growth and protein accumulation, but all the major subunits of the 7S and 11S storage protein fractions were detected. The ratio of 11S to 7S proteins was <1.0. Addition of 8.4 millimolar methionine overcame the restriction of cotyledon growth and protein accumulation in the sulfate-deficient media, and the ratio of 11S to 7S proteins was significantly increased. The amino acid compositions of the 7S and 11S fractions from sulfate-sufficient cotyledons and from sulfate-deficient cotyledons were not significantly different. There was no difference in fresh weight or total protein accumulation in cotyledons grown in 1.5 millimolar or 7.5 millimolar sulfate. At 7.5 millimolars sulfate, the 11S to 7S ratio was significantly increased, and the amount of beta-subunit in the 7S fraction decreased. At all sulfate levels supplemented with methionine, the 11S to 7S ratio was greater than 1, and no beta-subunit was detected in the 7S fraction. Supplemental methionine in media of any sulfate concentration increased growth and protein methionine content to a greater extent than high (7.5 millimolar) sulfate only. Adding supraoptimal sulfate is not equivalent to supplementing with methionine. Results of this study of in vitro growth are compared to results of studies of seed development on intact plants supplied with various sulfur concentrations.

Journal Article↗
PubMed1984

Clinical pharmacists prescribing drug therapy in a geriatric setting: outcome of a trial.

Clinical pharmacists, under the supervision of a family practitioner physician, assumed responsibility for drug management of geriatric patients in a Los Angeles skilled nursing facility. In a quasi-experimental, pretest-post-test control group design, outcome criteria were measured. Compared with the control group which received traditional patient care, the prescribing clinical pharmacists' group had a significantly lower number of deaths (P = 0.05), a significantly higher number of patients being discharged to lower levels of care (P = 0.03), and a significantly lower average number of drugs per patient (P = 0.04). The lower number of patients hospitalized approached significance (P = 0.06) in the prescribing clinical pharmacists' group. The practice of having clinical pharmacists prescribe drug therapy and render general care, under the supervision of a physician, has the potential for saving the health care system approximately $70,000 per year per 100 skilled nursing facility beds.

Aged↗
PubMed1984

Embolisation of host kidneys for the control of hypertension after renal transplantation: radiological aspects.

In this study 12 patients with drug-resistant hypertension after renal transplantation had their own kidneys ablated by therapeutic embolisation. The technical aspects of the procedure are described in detail. An improvement in blood-pressure control was achieved in eight of the 12 patients. These results are similar to those which have been reported after bilateral nephrectomy. It is concluded that embolisation of the host kidneys is a simple, effective and less hazardous alternative to surgery in the treatment of severe hypertension after renal transplantation.

Adult↗
PubMed1984

The problem of cytomegalovirus infection in renal allograft recipients.

A prospective study of the effects of cytomegalovirus (CMV) infection on 145 recipients of 155 renal allografts is reported. Immunosuppression was either with azathioprine and low-dose prednisolone (103 transplants) or with Cyclosporin A (52 transplants). Sixty-one cases of CMV infection were diagnosed; of those 21 were primary (i.e. in CMV sero-negative recipients) and 40 were secondary (i.e. in previously sero-positive recipients). The infection rate in patients treated with azathioprine and low-dose prednisolone did not differ from the rate in those treated with Cyclosporin A. Eighteen of the 21 primary CMV infections were clinically overt; several of these patients became seriously ill, and one of them died. Only four of the 40 secondary infections were overt, and these were all mild. Graft and patient survival were not adversely affected by CMV infection. Indeed the group with secondary CMV had significantly better survival rates than the uninfected sero-positive or sero-negative patient groups. Recommendations to minimise the effects of primary CMV infections are given.

Actuarial Analysis↗
PubMed1983

Exogenous methionine depresses level of mRNA for a soybean storage protein.

In vitro translation experiments indicate that absence of the beta-subunit of 7S storage protein in soybean (Glycine max L. Merr. cv. Provar) cotyledons cultured on methionine-supplemented medium is due to lack of functional mRNA for that polypeptide. Relative amounts of functional mRNA for the 7S alpha'- and alpha-subunits were unaffected by methionine in the cotyledon culture medium. Measurements of beta-subunit accumulation in cotyledons transferred from basal medium to methionine-supplemented medium show that methionine inhibits continued accumulation of the beta-subunit after synthesis of the beta-subunit has begun, and that methionine does not promote degradation of existing beta-subunit.

Antigens, Plant↗
PubMed1983

Surgery in patients with advanced germ cell malignancy following a clinical partial response to chemotherapy.

Twenty-one patients with metastatic germ cell tumors achieved only partial clinical tumor regression following chemotherapy, and underwent surgical biopsy or resection of the residual tumor deposits. Sixteen (76%) are at present clinically disease-free after a median 30 + months (range 17-50 months) from the time of surgery, and five (24%) died after 9-29 months. Adverse prognostic signs were the finding of persistent cancer at histopathological examination of the resected tumor masses, and the presence of elevated serum tumor markers at the time of surgery. Postchemotherapy surgery in this setting provides tissue for the prognostically important histopathological examination on which a decision regarding further chemotherapy may be based. In addition, it provides tumor bulk reduction in the cases of differentiated teratoma and persistent cancer.

Adolescent↗
PubMed1983

Structure of E. coli 16S RNA elucidated by psoralen crosslinking.

E. coli 16S RNA in solution was photoreacted with hydroxymethyltrimethylpsoralen and long wave ultraviolet light. Positions of crosslinks were determined to high resolution by partially digesting the RNA with T1 RNase, separating the crosslinked fragments by two-dimensional gel electrophoresis, reversing the crosslink, and sequencing the separated fragments. This method yielded the locations of crosslinks to +/- 15 nucleotides. Even finer placement has been made on the basis of our knowledge of psoralen reactivity. Thirteen unique crosslinks were mapped. Seven crosslinks confirmed regions of secondary structure which had been predicted in published phylogenetic models, three crosslinks discriminated between phylogenetic models, and three proved the existence of new structures. The new structures were all long range interactions which appear to be in dynamic equilibrium with local secondary structure. Because this technique yields direct information about the secondary structure of large RNAs, it should prove invaluable in studying the structure of other RNAs of all sizes.

Base Sequence↗