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Biomedical subjects

J C Jones

Publications and source records attributed to J C Jones.

At least 145 records · Page 8Linked to original sources
PubMed1984

An investigation into the type of union achieved between cast cores and Wiptam wire posts.

The type of union formed between Wiptam wire posts and cast cores has been investigated. Scanning electron microscopy of sectioned 'as cast' specimens showed that the union between Wiptam posts and cast cores was predominantly mechanical in nature. Diffusion studies, however, using an X-ray Microanalysis Unit, revealed that there was evidence of diffusion of silver atoms into the post from the core. This suggests that the bonding between the two components is not merely a simple mechanical lock.

Chemical Phenomena↗
PubMed1984

Antiestrogen-cytotoxic chemotherapy and bacillus Calmette-Guerin vaccination in stage II breast cancer: seventy-two-month follow-up.

A prospective, randomized clinical trial of adjuvant treatment of 312 stage II breast cancer patients with use of chemotherapy, antiestrogen therapy, and immunotherapy is reported after 72 months of follow-up. The stratification of patients was based on nodal involvement and estrogen receptor (ER) assay of the primary tumors. Findings at 72 months indicate that antiestrogen therapy (tamoxifen, Nolvadex) added to chemotherapy with cyclophosphamide (Cytoxan), methotrexate, and fluorouracil (5-Fluorouracil) (CMF) resulted in significant delayed recurrence in ER-positive postmenopausal patients, ER-positive patients with four or more positive nodes, and ER-positive patients with tumors greater than 3 cm in diameter. The addition of nonspecific immunotherapy with bacillus Calmette-Guerin had no effect on disease-free survival. ER and progesterone receptor measurements in patients with primary breast cancer provide valuable prognostic information on subsequent recurrence and overall survival and should be documented in future clinical trials.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1983

Adjuvant endocrine therapy, cytotoxic chemotherapy, and immunotherapy in stage-II breast cancer: five-year results.

Five-year results of a prospective, randomized clinical trial of three treatment regimes--(a) cytoxan, methotrexate, and 5-fluorouracil (CMF); (b) CMF plus the antiestrogen drug, tamoxifen (CMFT); and (c) CMFT plus bacillus Calmette-Guerin (BCG) vaccinations--in 312 women with stage-II breast cancer are reported. Estrogen receptors (ER) were measured in all of the primary tumors. Addition of tamoxifen to CMF therapy significantly decreased the number of recurrences at five years in ER positive patients with four or more positive axillary lymph nodes. Addition of tamoxifen to CMF had no effect on disease-free survival in ER-positive patients with 1-3 positive axillary lymph nodes or in patients with ER-negative tumors. Addition of BCG vaccinations had no discernible effect on disease-free survival. ER measurements in the primary tumor provide important prognostic information regardless of treatment, with ER-positive patients having lower recurrence rates and mortality after five years. ER measurements also have predictive value for response to endocrine therapy. Further follow-up is needed to determine whether tamoxifen is delaying recurrence or preventing it in a subset of these patients.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1983

Genetic linkage and HLA association in congenital adrenal hyperplasia due to 21-hydroxylase deficiency.

Twenty-eight families of patients with congenital adrenal hyperplasia due to 21-hydroxylase (21-OH) deficiency were studied to evaluate the specific HLA linkage relationship and HLA antigen association to the 21-OH deficiency gene. Genotype assignment, based on hormonal studies (ACTH stimulation) and HLA genotyping, correlated very well (p less than 0.01) in 23 unaffected sibs of children with 21-OH deficiency further supporting the genetic linkage of the 21-OH deficiency gene to the HLA complex. One family was informative for the placement of the 21-OH deficiency gene outside the HLA complex on the HLA-DR locus side. In this family HLA-A, B, C, DR, MT, MB, and glyoxylase typing and mixed lymphocyte culture was performed. An association of 21-OH deficiency and the HLA-A3 antigen was noted in the 28 families. This association is not secondary to the association of the 21-OH deficiency gene with HLA-BW47.

Adrenal Hyperplasia, Congenital↗
PubMed1983

The role of pseudorabies virus thymidine kinase expression in trigeminal ganglion infection.

The role of pseudorabies virus (PRV) thymidine kinase (TK) expression in the pathogenesis of PRV infection of mice was studied with TK-negative (TK-) mutants. Thymidine phosphorylation and arabinosylthymine inhibition of PRV replication and efficiency of plating were used to characterize TK+ and TK- PRV. In addition, a plaque autoradiography procedure was utilized to determine the TK phenotype of individual plaques. TK+ and TK- PRV replicated well in ocular tissues, while TK+ but not TK- did so in ganglion tissue. Mortality was absent after TK- PRV inoculation and widespread after inoculation of similar amounts of TK+ PRV. Latent infection in mice was not detected with either TK+ or TK- PRV. This study indicated the probable importance of PRV TK expression in acute trigeminal ganglion infection.

Animals↗
PubMed1983

A highly sensitive cytochemical bioassay for plasma angiotensin II.

A highly sensitive cytochemical bioassay has been developed for measuring angiotensin II in human plasma. The assay depends on the ability of angiotensin II to alter the reducing potency of the zona glomerulosa as measured by Prussian blue staining and microdensitometry. An inverse correlation between the intensity of the stain and the logarithm of concentration existed over the range 0.05-5.0 fmol/1 of angiotensin II. The limit of sensitivity of the assay in plasma was 50 fmol/1; the index of precision was 0.07 +/- 0.04 (mean +/- SD; n = 15); and the coefficient of variation of a quality control sample was 34%. The response was specific for angiotensin II; approximately 10(2) times more angiotensin III and approximately 10(6) times more ACTH was required to produce a similar effect. Angiotensin I had no significant activity. A significant inverse relationship existed between sodium intake and bioactive angiotensin II in 5 normal subjects studied on low, normal and high sodium diets. Extremely low levels of angiotensin II were detected in anephric subjects.

Angiotensin II↗
PubMed1983

Thymidine plaque autoradiography of thymidine kinase-positive and thymidine kinase-negative herpesviruses.

Plaques formed by herpes simplex virus (HSV), pseudorabies virus, and varicella-zoster virus were studied by plaque autoradiography after [14C]thymidine labeling. Standard thymidine kinase-positive (TK+) viruses and TK- mutants of HSV types 1 and 2 and pseudorabies virus were studied, including cell cultured viruses and viruses isolated from animals. Autoradiography was performed with X-ray film with an exposure time of 5 days. After development of films, TK+ plaques showed dark rims due to isotope incorporation, whereas TK- plaques were minimally labeled. Plaque autoradiography of stock TK- viruses showed reversion frequencies to the TK+ phenotype of less than 10(-3). Autoradiography indicated that TK- virus retained the TK- phenotype after replication in vivo. In addition, it was shown that TK- HSV could be isolated from mouse trigeminal ganglion tissue after corneal inoculation of TK- HSV together with TK+ HSV. The plaque autoradiographic procedure was very useful to evaluate proportions of TK+ and TK- virus present in TK+-TK- virus mixtures.

Animals↗
PubMed1982

Captopril in essential hypertension; contrasting effects of adding hydrochlorothiazide or propranolol.

Twenty-four patients with moderate to severe hypertension were treated for four weeks with captopril, an oral inhibitor of angiotensin-converting enzyme. The fall in blood pressure with captopril alone correlated with pretreatment plasma renin activity. The effect of adding either hydrochlorothiazide or propranolol to the captopril treatment was then studied. The addition of hydrochlorothiazide to captopril produced a dose-dependent fall in blood pressure. At the higher dose of the diuretic this fall in blood pressure correlated with weight loss, suggesting that when the diuretic-induced compensatory rise in angiotensin II is prevented by captopril the fall in blood pressure becomes dependent on loss of sodium and water. In contrast, the addition of propranolol to captopril produced no further fall in blood pressure, suggesting that inhibition of angiotensin-converting enzyme prevents the blood pressure lowering effect of propranolol. This may have implications for the mechanism whereby beta-blockers alone lower blood pressure. These contrasting effects of hydrochlorothiazide and propranolol in the presence of captopril indicate that in patients whose hypertension is not controlled by captopril alone the addition of increasing doses of diuretic is likely to control the blood pressure. The addition of a beta-blocker, however, is less likely to be effective.

Adult↗
PubMed1982

Dynamic aspects of the supramolecular organization of intermediate filament networks in cultured epidermal cells.

We have shown, by indirect immunofluorescence microscopy using an antiserum against the mouse keratin subunit K2 and by electron microscopy, that transformed (PAM) and primary (PME) mouse epidermal cells possess extensive networks of IF bundles. Following trypsinization and replating of PAM cells, IF bundles are seen to move as a continuous network from a perinuclear zone into the peripheral cytoplasmic regions. In PAM cells lysed in high-ionic-strength solutions containing Triton X-100 and DNAase-1, IF bundles appear to be closely associated with nuclear envelope remnants and, in some cases, appear to be attached to nuclear pore complexes. PME cells cultivated in low Ca2+-containing medium possess perinuclear birefringent arrays of IF bundles. Within 2 hours of switching the cells to normal Ca2+ levels, the PME IF bundle network moves towards and establishes contact with the cell surface as desmosomes form. Live cells observed by phase contrast and fixed cells observed by immunofluorescence microscopy demonstrate that desmosomes can be distinguished as dark bands separating neighboring cells. There is little difference between the major proteins seen in SDS-polyacrylamide gel profiles of isolated IF bundle networks from PME cells before and after the Ca2+ switch. Therefore, a reorganization of relatively insoluble membrane-associated protein following the Ca2+ switch may be involved in desmosome formation. The isolated IF networks from PAM cells differ in protein composition compared to the PME IF networks. This may be related to the greatly reduced number of desmosomes in PAM cells. The IF bundle system in epidermal cells appears to be involved in shape formation, shape maintenance, the establishment of desmosomes, nuclear centration, and cell-cell contact.

Animals↗
PubMed1982

Estrogen receptor status as a prognostic indicator for stage I breast cancer patients.

The prognostic value of estrogen receptor determination was studied for 510 stage I (axillary node negative) breast cancer patients treated by mastectomy alone. Results at 60 months after mastectomy indicate that stage I patients whose tumors lack estrogen receptors fall into a significantly poorer prognostic group for both recurrence and survival than those whose tumors contain estrogen receptors. Within the postmenopausal group, estrogen receptor negative (ER -) patients are recurring more rapidly than estrogen receptor positive (ER +) patients. Within the premenopausal group, ER + patients have a recurrence rate identical to ER - patients, which is apparent only after prolonged follow-up. In contrast to postmenopausal ER + patients, premenopausal ER + patients appear to have no prognostic advantage over the ER - patients, and thus constitute a high risk group for which adjuvant endocrine therapy might prove beneficial.

Breast Neoplasms↗
PubMed1981

Relation between arterial pressure, dietary sodium intake, and renin system in essential hypertension.

Forty-one patients with mild essential hypertension, 36 patients with severe hypertension, and 28 normotensive subjects were studied on a high sodium intake of 350 mmol/day for five days and low sodium intake of 10 mmol/day for five days. The fall in mean arterial pressure on changing from the high-sodium to the low-sodium diet was 0.7 +/- 1.7 mm Hg in normotensive subjects, 8 +/- 1.4 mm Hg in patients with mild hypertension, and 14.5 +/- 1.4 mm Hg in patients with severe hypertension. The fall in blood pressure was not correlated with age. Highly significant correlations were obtained for all subjects between the ratio of the fall in mean arterial pressure to the fall in urinary sodium excretion on changing from a high- to a low-sodium diet and (a) the level of supine blood pressure on normal diet, (b) the rise in plasma renin activity, and (c) the rise in plasma aldosterone. In patients with essential hypertension the blood pressure is sensitive to alterations in sodium intake. This may be partly due to some change either produced by or associated directly with the hypertension. A decreased responsiveness of the renin-angiotensin-aldosterone system shown in the patients with essential hypertension could partly account for the results.

Adult↗