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J Joyce

Publications and source records attributed to J Joyce.

At least 37 records · Page 2Linked to original sources
PubMed1991

Effects of various fixatives and fixation conditions on DNA ploidy analysis. A need for strict internal DNA standards.

DNA ploidy and cell cycle analyses are being used with increasing frequency as additional, sometimes independent, biologic prognosticators of various malignancies. For obvious reasons, most of the large studies published are retrospective, using archival paraffin-embedded tissues likely to have been fixed and processed differently. To assess the effect of various fixation conditions on ploidy analyses, the authors performed a comprehensive study in which five contiguous aliquots from 26 tissue samples were fixed in formalin for 8. 24, and 48 hours; B5; and the ethanol-based fixative Omnifix (Omni, Xenetics Biomed Inc., Irvine, CA), respectively. The samples were prepared and stained with the use of Hedley's method; the DNA analyses were done with a Coulter EPICS V flow cytometer (Coulter Electronics, Hialeah, FL); and the resulting histograms were interpreted with Multicycle software (Phoenix Flow Systems, San Diego, CA). Mean channels and coefficients of variation (CVs) of the G0/G1 peaks were compared. Increasing fixation times in formalin produced slight shifting to the left on the G0/G1 peaks with differences up to 13 channels. Omni caused similar but more conspicuous changes, with maximal shifting of 51 channels. B5 created the opposite effect, with right-shifted G0/G1 peaks up to 22 channels. The CVs deteriorated progressively with increasing fixation times in formalin. B5 and Omni fixatives conferred the worse histograms, with 6 and 15 cases, respectively, displaying CVs greater than 8. Such significant differences preclude the use of any other internal standard but adjacent normal tissue that was processed exactly the same as the tumor. The validity of DNA results obtained otherwise should be considered questionable. These findings may explain some of the previously published controversial reports and emphasize the need to use an internal standard and more stringent criteria to define aneuploidy in paraffin-embedded tissue.

Cell Cycle↗
PubMed1990

Does rapid microwave fixation improve immunohistochemistry?

Microwave fixation in dilute aldehyde solution has been reported to be superior to fixation in formaldehyde for the preservation of antigens. We studied antigen preservation among tissues which were soaked in formaldehyde, dilute aldehyde, alcohol, and saline solution with or without microwave irradiation. Microwave fixation was found to be superior to conventional formaldehyde fixation with regard to antigen preservation. However, there was no detectable difference in immunostaining between any of the irradiated and nonirradiated alcohol-, aldehyde-, or even saline-treated tissues. Microwave-irradiated tissues, regardless of the fixative employed, displayed a tendency for tissue disintegration upon protease treatment, as is commonly seen in alcohol-fixed tissues. Our results suggest that the apparent improvement in antigen preservation when microwave fixation in dilute aldehyde solution is used is largely attributable to the fixation in alcohol during the graded alcohol dehydration steps in the tissue processor, rather than to any demonstrable effect of the microwave radiation per se.

Fixatives↗
PubMed1989

Antiproliferative effect of IFN-gamma in immune regulation. III. Differential selection of TH1 and TH2 murine helper T lymphocyte clones using recombinant IL-2 and recombinant IFN-gamma.

Supernatants collected after primary or secondary stimulation of spleen cells contain different arrays of lymphokines. Primary supernatants from spleen cells stimulated with Con A or allogeneic spleen cells (MLC-SF) contain IL-2 but little IL-4 or IGN-gamma; in contrast, secondary MLC-SF contains IL-2 as well as substantial IL-4 and IFN-gamma. Our laboratory previously had always used secondary MLC-SF for cloning T cells, and had routinely obtained TH1 helper T lymphocyte clones. In the present study, when primary Con A-SF was used as source of growth factors, TH2 and not TH1 clones were preferentially derived. Considering the possibility that IFN-gamma may be one important factor in determining whether TH1 or TH2 clones are preferentially obtained, clone derivation was then performed either in the presence of rIL-2 or rIL-2 plus rIFN-gamma. The majority of clones derived using rIL-2 alone were TH2 cells, whereas the majority of clones derived using rIL-2 plus rIFN-gamma were TH1 cells. Using either procedure, some clones were obtained that produced IL-2, IL-4, and IFN-gamma. These data are consistent with our previous observations that IFN-gamma inhibits the proliferation of TH2 but not TH1 clones, and suggest that the presence of IFN-gamma during an immune response would result in the preferential expansion of helper T lymphocytes of the TH1 phenotype. Our procedure for the differential selection of TH1 and TH2 clones reactive with the same Ag should be useful for designing in vitro systems for studying the function of these cell subsets in specific immune responses.

Animals↗
PubMed1989

Postmortem analysis of adrenal-medulla-to-caudate autograft in a patient with Parkinson's disease.

A 53-year-old physician who had a 10-year history of progressive idiopathic parkinsonism survived for 4 months after an autologous adrenal-medulla-to-right-caudate autograft but he received little clinical benefit. A small number of chromaffin cells in the graft site survived; they expressed neurofilament proteins and chromogranin A, but scant tyrosine hydroxylase. The striatum on both sides showed almost complete loss of [3H]mazindol binding to dopamine-uptake sites; the density of dopamine receptors was decreased adjacent to the transplant but increased rostral to the transplant. These results demonstrate that autografted chromaffin cells can survive for 4 months after transplantation and that related changes in dopamine receptors can be quantified.

Adrenal Medulla↗
PubMed1984

The irreversible loss of alanine and of glycine in fetal and sucking lambs.

Estimates have been made of the irreversible loss of alanine and of glycine in chronically catheterized fetal lambs and in sucking lambs using [U-14C]-labelled radioisotopes. The experiments in the fetal lambs were carried out at least 5 d after implantation of catheters. The mean concentration of glycine in fetal femoral arterial blood between 102 and 129 d conceptual age was 755 mumol/l and this was not significantly different from that in maternal venous blood. The mean concentration of alanine in fetal femoral arterial blood during the same period of gestation was 229 mumol/l and this was significantly greater than that in maternal venous blood. Assuming a catenary model, the mean irreversible loss of glycine, determined using the single-injection technique, in three fetal lambs of 107, 111 and 127 d conceptual age was 17 mumol/min per kg, whereas in two fetal lambs aged 106 and 109 d into which the isotope was infused continuously the mean irreversible loss, calculated from the specific activity of glycine 5 h after the start of infusion of the tracer ('pseudo plateau'), was 12 mumol/min per kg. In a sucking lamb, 9 d after birth, the irreversible loss of glycine was 11 mumol/min per kg. The mean irreversible loss of alanine, determined by the single-injection technique assuming a catenary model in five fetuses between 112 and 121 d conceptual age was 14 mumol/min per kg, and in two sucking lambs, 9 and 11 d after birth, it was 5.1 mumol/min per kg. When a two-pool model was assumed in which entry of metabolite was not directly into the sampling pool but was by way of the second pool, then the mean irreversible loss of glycine in the three fetuses was 23 mumol/min per kg and of alanine in the five fetuses was 32 mumol/min per kg. Calculations based on the alternative two-pool model did not alter appreciably the rates of irreversible loss of either alanine or glycine in the sucking lambs. From a comparison of the specific activities of the amino acids and of carbon dioxide in blood during the course of the experiments, it was found that in the fetuses 0.96% of the CO2 present in blood was derived from alanine and only 0.12% was derived from glycine. It was calculated that not more than 1.6 mumol alanine/min per kg and 0.29 mumol glycine/min per kg could have been converted to CO2 in the fetal lambs.(ABSTRACT TRUNCATED AT 400 WORDS)

Alanine↗
PubMed1977

On the tryptic peptides from hemoglobin chains of six carnivores.

The amino acid compositions of the tryptic peptides of the following carnivore hemoglobin chains have been determined: gray fox (Urocyon cineroargenteus); raccoon (Procyon lotor); polar bear (Thalarctos maritimus); coati mundi (Nasua nasua) beta chain; coati mundi (Nasua narica) two beta chains; cat (Felis catus) alpha chain; and lion (Pantbera leo) beta chain. These provide a basis for future sequencing of these hemoglobins and construction of an evolutionary tree. The specific results are summarized in the following article (Stenzel and Brimhall, 1977).

Amino Acid Sequence↗
PubMed1977

Smoke, burns, and the natural history of inhalation injury in fire victims: a correlation of experimental and clinical data.

Mortality and morbidity in fire victims is largely a function of injury due to heat and/or smoke. While degree and area of burn together constitute a reliable numerical measure of cutaneous injury due to heat, as yet no satisfactory measure of inhalation injury has been developed. In this study, with fluid resuscitation and pulmonary infection eliminated as variables, dose-response curves were constructed as a measure of inhalation injury by exposing burned and unburned animals to smoke of constant temperature and toxicity under conditions similar to the fire situation. In these animals, the natural history of inhalation injury: 1) proved to be a relatively simple function of smoke and burn dosage; 2) appeared to simulate and therefore aid interpretation of the inhalation injury syndromes seen in human fire victims; 3) indicated that within limits [COHgb] measured immediately after injury was directly proportional to, and might prove to be a clinically valuable measure of, absorbed dose of smoke. While fluid resuscitation and pulmonary contamination with bacterial pathogens may be eliminated experimentally, such is not the case with the vast majority of fire victims admitted to burn services with associated inhalation injury. Fluid resuscitation and inhalation of a Pseudomonas aeruginosa aerosol were therefore included serially in a study of animals with inhalation injury and burns large enough to require fluid resuscitation. In these animals it was demonstrated that: 1) pulmonary edema occurred in association with too little rather than too much fluid therapy; 2) after aerosol inoculation, fatal bacterial pneumonia was difficult to produce when inhalation injury was associated with no or only small burns, but common when associated with no or only small burns, but common when associated with a burn large enough to require fluid resuscitation.

Animals↗