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Biomedical subjects

R T Jones

Publications and source records attributed to R T Jones.

At least 325 records · Page 18Linked to original sources
PubMed1976

Abnormal hemoglobins in a quarter million people.

Hemolysates of erythrocytes from more than a quarter million people in Alabama were electrophoresed on cellulose acetate, pH 8.4, and those samples exhibiting an abnormality were also electrophoresed in citrate agar, pH 6.0. The globin chains of mutants other than Hb S and C were electrophoresed in urea-mercaptoethanol buffers at both pH 8.9 and pH 6.0, and 60 of them were also analyzed structurally. Of about 6000 samples from whites, only three contained abnormal hemoglobins--Hb D Los Angeles, Hb J Baltimore, and one unidentified. Of 249,000 samples from blacks, about 29,000 contained electrophoretically detectable abnormalities, most of them associated with Hb S or C, present in a frequency of about 9% and 3%, respectively. About 1000 samples resolved into patterns of potential clinical significance. Twenty other mutant hemoglobins were detected, in various genetic combinations in 164 kindreds; four of these-Hb Alabama, Montgomery, Titusville, and Mobile--were previously unknown. The methods used are rapid, economical, and well suited for large scale surveys. They provide highly specific characterizations of many mutant hemoglobins, and no discrepancies were found between the presumptive identifications based on these characterizations and the definitive identifications obtained from structural analyses.

Alabama↗
PubMed1976

Quantitation of cannabinoids in biological fluids by radioimmunoassay.

A tritium based radioimmunoassay for delta9THC and its metabolites has been developed for the use of investigators studying the epidemiological, medical, clinical, and research aspects of cannabis use. The assay is sufficiently sensitive to detect cannabinoids in the urine of marijuana smokers for several days after their last exposure to the drug. The results obtained from a 28 day study indicate that the assay reflects the administration and removal of oral doses of THC. The specificity of the antisera, as determined in cross reactivity studies, allows not only the assay of metabolites in biological samples without interference from other drugs, but also the evaluation of extracts of other kinds of samples which may contain unmetabolized delta9THC. The technique of radioimmunoassay has many advantages over other methods of analysis. It is simple to perform and can be readily applied to the rapid analysis of large numbers of samples. It can be used in the direct analysis of physiological fluids and other biological samples which ordinarily have to be processed before other techniques can be applied. The method is non-destructive abd obviates the need to use radiolabelled drugs in man during metabolic and other studies. This radioimmunoassay has been designed with particular emphasis on ease of use by other investigators. We anticipate that it will prove useful to investigators and scientists for determining the absence, or presence and amount, of THC metabolite in a biological specimen, for epidemiologists in determining the full extent of cannabis use and to the medical/clinical community for establishing the minimum effective dose of delta9THC for each patient. The widespread application of a single method of analysis should also remove a great deal of the controversy surrounding marijuana studies performed to date.

Animals↗
PubMed1975

Cellular and subcellular effects of ischemia on the pancreatic acinar cell: in vitro studies of rat tissue.

Rat pancreatic slices were incubated at 37 degrees C in vitro, in order to determine if complete ischemia would reproduce the subcellular alterations seen in human pancreatic acinar cells following shock. The ultrastructural alterations observed were similar to those seen in humans and in animal models of hypovolemic shock. These changes ranged from dilated endoplasmic reticulum and swollen mitochondria (reversible changes) to mitochondrial flocculent densities and later stages (evidence of cell death). In this in vitro study the pancreas remained in an apparently reversible stage longer than liver, heart, kidney, and brain treated similarly. However, once the pancreatic cells died, necrotic breakdown occurred very rapidly, perhaps due to intracellular release of lysosomal and zymogen granule hydrolases.

Animals↗
PubMed1975

Isolation and functional characterization of hemoglobin Casper: beta106(G8) Leu replaced by Pro.

Hemoglobin Casper (beta106Leu replaced by Pro) can be separated from hemoglobin (Hb) A by isoelectric focusing on polyacrylamide gel. This abnormal hemoglobin was estimated to be 30% of teh total by both isoelectric focusing and heat lability kinetics. Its oxygen equilibrium curves indicate a high oxygen affinity, low degree of subunit interaction, and a decreased Bohr effect. Mixtures of Hb Casper and Hb A appear to bind oxygen as if no hybrid molecules exist.

Diphosphoglyceric Acids↗
PubMed1975

Haemoglobin F Victoria Jubilee (alpha 2 A gamma 2 80 Asp-Try).

A new A gamma chain haemoglobin variant, haemoglobin F Victoria Jubilee, with an electrophoretic mobility slightly anodal to haemoglobin F Port Royal, was found in a Jamaican infant. The amino acid residue substitution of 80 Aspartic Acid leads to Tyrosine was associated with alanine in position 136. Haemoglobin F Victoria Jubilee constituted about 7.0 percent of the total haemoglobin F.

Adult↗
PubMed1975

Two new hemoglobins. Hemoglobin Alabama (beta39(C5)Gln leads to Lys) and hemoglobin Montgomery (alpha 48(CD 6) Leu leads to Arg).

The amino acid substitutions in two new hemoglobins found by electrophoretic screening during a survey in Alabama have been determined by column chromatography and amino acid analyses of their tryptic peptides. They are hemoglobin Alabama (beta 39(C 5)Gln leads to Lys) and hemoglobin Montgomery (alpha 48(CD 6) Leu leads to Arg). No harmful symptoms have been attributed to the presence of either hemoglobin.

Adult↗
PubMed1975

Cardiovascular effects of prolonged delta-9-tetrahydrocannabinol ingestion.

In contrast to the tachycardia and unchanged or increased blood pressure seen after single doses, prolonged delta-9-tetrahydrocannabinol (THC) ingestion produced significant heart rate slowing and blood pressure lowering in hospitalized volunteers. Impaired circulatory responses to standing, exercise, Valsalva maneuver, and cold pressor testing suggest a state of sympathetic insufficiency. Marked weight gain was observed in all subjects, which has been shown to be related to fluid retention and plasma volume expansion. Tolerance developed to orthostatic hypotension, possibly related to plasma volume expansion, but did not develop to the supine hypotensive effects. Nearly complete tolerance developed to the tachycardia and psychological effects produced by smoked marijuana while ingesting THC. Electrocardiographic changes were minimal despite the large cumulative dose of THC. The hypothesis that THC has a biphasic effect on the sympathetic nervous system in man, producing excitation with single doses and inhibition with prolonged administration, is discussed.

Administration, Oral↗
PubMed1975

Hb Mobile [alpha2beta2 73(E17)Asp replaced by Val]: a new variant.

A new hemoglobin variant found in a mother and her child was characterized by column chromatography of the tryptic hydrolysate of the aminoethylated, glycinamidated beta-chain, followed by chymotryptic digestion of the abnormal beta T-9 peptide and amino acid analyses. It was shown to be alpha2beta2 73(E17)Asp replaced by Val and named by Hb Mobile.

Adult↗
PubMed1975

Measurement of IgE antibodies by the radioallergosorbent test. I. Technical considerations in the performance of the test.

Since its introduction by Wide, Bennich, and Johansson in 1967, the radioallergosorbent test (RAST) has been increasingly used for measurement of specific IgE antibodies. In this study we have varied the conditions during the performance of the RAST and have investigated the effect of altering: (1) the speed of rotation of tubes, (2) the number of washes in both steps of the test, (3) the length of rotation of tubes, (4) the temperature, (5) the conditions during centrifugation, (6) the quantity of antibody to IgE in the second step of the test, (7) the composition of buffers in the reactions, (8) the type of tube employed in the test, (9) the quantity of antigen employed during the coupling procedure, and, finally, (10) the iodine isotope, 125I or 131I, used to radiolabel anti-IgE. Of these variables the most significant were the quantity of anti-IgE used in the second step of the test and the quantity of antigen used in the coupling procedure. Other variables of importance were the choice of radioiodine, whether the tubes were rotated or not, the type of tube used, and finally the diluent employed.

Allergens↗
PubMed1975

Measurement of IgE antibodies by the radioallergosorbent test. II. Analyses of quantitative relationships in the test.

IgE antibodies have been measured by the radioallergosorbent test (RAST) and the relative amounts present in serum determined by comparison with reference standards. In this study we analyzed the quantitative aspects of the binding of IgE antibody to solid-phase ragweed antigens. With the volumes of allergic serum usually tested, IgE antibodies are in excess in the first step of the RAST. The inability of solid-phase antigens to remove IgE antibody appeared to be due to an insufficient quantity of antigen on the particles rather than steric interference with binding of IgE antibody. Dose-response curves with serums from several ragweed-sensitive subjects were not parallel when plotted on a semilog scale. In contrast, log-log plots of dose-response curves with serums from ragweed-sensitive subjects were nearly parallel. Log-log plots of dose-response curves with serums from subjects with ragweed and grass sensitivity and tested with the appropriate solid-phase antigens also were nearly parallel. Because of the latter finding, RAST could be standardized using a reference serum in every assay and plotting the results on a log-log scale. Finally, because IgE antibody is in excess in the RAST as it is usually performed, the final result reflects both the quantity and the affinity of the IgE antibody.

Allergens↗
PubMed1975

The application of electron microscopy and cellular biochemistry to the autopsy. Observations on cellular changes in human shock.

A method based on the utilization of electron microscopy, morphometric analysis, tissue culture, and biochemical analysis in the study of human autopsies is described. In this method rapid sampling immediately following somatic death is conducted in order to make meaningful the application of such techniques. In addition to describing the procedure, we present some new findings relating to cellular changes associated with shock. As in cellular pathobiology, it is of utmost importance that ultrastructural changes be correlated with alterations in chemistry and function.

Adolescent↗
PubMed1975

Alcohol and marijuana effects on static visual acuity.

Static visual acuity was measured at two contrast levels (12 and 49%) in ten subjects in a double blind experiment involving five drug conditions of alcohol and marijuana (0.5 ml and 1.0 ml/kg body weight of 95% ethanol, 8 and 15 mg delta-9-tetrahydrocannabinol (THC), and a placebo). We found no statistically significant change in static visual acuity for any of the dose levels at any of the measurement time up to six hours following drug ingestion; this is sharply contrasted with the marked decrements in acuity which were found in the same subjects under the same drug conditions when the targets were in motion and required corrdinated eye movements for their resolution.

Adolescent↗
PubMed1975

Marijuana smoking and reduced pressure in human eyes: drug action or epiphenomenon?

Normal pressure within the human eye was reduced after smoking a socially relevant dose of marijuana (12 mg. delta9-9-tetrahydrocannabinol), but only for light to moderate users who experienced a substantial "high" and a state of peaceful relaxation from the experimental dose. Analysis suggests an indirect effect of the drug associated with relaxation-a psychophysiologic state that can be produced by drug and nondrug means.

Adolescent↗
PubMed1975

Polycythemia produced by hemoglobin Osler (beta-145 (HC2) Tyr yields Asp).

Polycythemia in a black woman was associated with hemoglobin Osler. In this hemoglobin the tyrosine at the penultimate position of the beta chain is replaced by aspartic acid. As a result oxygen affinity of the hemoglobin is very high, heme-heme interaction is absent, and the influence of hydrogen ion and 2,3 diphosphoglycerate on oxygen affinity is attenuated.

Adult↗
PubMed1975

Effects of shock on the pancreatic acinar cell. Cellular and subcellular effects in humans.

Pancreatic tissues from 22 patients with a wide variety of types of shock were obtained within minutes of somatic death for light and electron microscopy and for cytochemical studies. By light microscopy, it was difficult to ascertain any differences between the shock groups; however, electron microscopy disclosed subcellular alterations that could be correlated well with the type, severity, and duration of shock. Mild cases of shock or shock of short duration showed mild cell damage, while extreme cases of hemorrhagic or septic shock showed cell death and necrosis. No morphological evidence for lysosomal initiation of damage was seen, but it is clear that the pancreas can undergo severe cell injury during shock that could result in release of further damaging enzymes, most probably from zymogen granules rather than from lysosomes.

Adolescent↗