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Biomedical subjects

D K Jones

Publications and source records attributed to D K Jones.

14 recordsLinked to original sources
PubMed1992

Release of von Willebrand factor antigen (vWF:Ag) and eicosanoids during acute injury to the isolated rat lung.

It has been suggested that the von Willebrand factor antigen (vWF:Ag) may be a clinical marker for pulmonary endothelial cell injury. An ELISA was developed for the measurement of rat vWF:Ag. Rat lungs were isolated and perfused with a recirculating, blood-free, physiologic salt solution. Circulating levels of vWF:Ag and the eicosanoids thromboxane B2 (TXB2) and prostaglandin 6-keto F1-alpha (6-keto PGF1 alpha) were measured before and after different forms of insult. The addition of phospholipase C (PLC) or hydrogen peroxide (H2O2) to the perfusate caused lung damage as manifested by pulmonary artery pressure increase and pulmonary edema. This was paralleled by significant release of vWF:Ag, TXB2, and 6-keto PGF1 alpha. Increased hydrostatic pressure caused pulmonary edema without vWF:Ag and eicosanoid release. The addition of vasopressin to the perfusate caused vWF:Ag release but no lung injury and no release of eicosanoids. It is concluded that in the rat model, vWF:Ag release is a nonspecific marker for lung injury.

6-Ketoprostaglandin F1 alpha↗
PubMed1990

The influence of sex-class, USDA yield grade and USDA quality grade on seam fat trim from the primals of beef carcasses.

Beef carcasses (129 steers and 80 heifers) differing in weight, muscling, fatness and marbling score were selected to represent the full spectrum of USDA yield grades; one side was fabricated into boneless primal cuts. Primals were trimmed of all external fat and intermuscular (seam) fat and all components were weighed. Regression equations were developed to predict the percentage of seam fat on an external fat-free primal basis using USDA yield grade (YG), marbling score and a squared function of YG as the independent variables. YG (.77) and marbling score (.67) were highly correlated to seam fat. Heifers tended to have a higher predicted percentage of seam fat than did steers across all YG. Primals from USDA Choice carcasses had approximately 1.0 percentage point more predicted seam fat than did USDA Select primals at the same YG and sex-class. The YG 2.5 heifers had similar proportions of predicted seam fat from primals as YG 3.5 steers, but YG 3.5 heifers tended to have more seam fat than YG 4.5 steers. The same trend was noted between YG 4.5 heifers and YG 5.5 steers, indicating a sex-related deposition of seam fat in fed cattle.

Adipose Tissue↗
PubMed1988

Changes in factor VIII proteins after cardiopulmonary bypass in man suggest endothelial damage.

16 patients undergoing coronary artery bypass grafting using cardiopulmonary bypass (CPB) had blood samples taken at various times before, during and up to 1 week after surgery for estimation of beta-thromboglobulin (BTG), alpha-1-antichymotrypsin (ACT), factor VIII procoagulant protein (VIII:C), von Willebrand factor antigen (vWF:Ag) and ristocetin co-factor (vWF:RiCoF). vWF:Ag and vWF:RiCoF rose during and following surgery in a different manner to ACT. At 1 week there was a significantly disproportionate rise in vWF:Ag compared to vWF:RiCoF which suggested a degree of pulmonary endothelial damage. Prostacyclin, which was administered to 8 of the patients during CPB, reduced platelet activation as measured by a reduction in the release of BTG and also attenuated the consumption of VIII:C. It had no effect on pulmonary endothelial damage as measured by the ratio of vWF:Ag to vWF:RiCoF.

Adult↗
PubMed1987

The rapid reversibility of effects of changing lung volume on the clearance rate of inhaled 99Tcm-DTPA in man.

Five normal non-smoking subjects inhaled an aerosol of 99Tcm-DTPA in saline with a mass median aerodynamic diameter of 0.6 micron. The rate of clearance (k) of the inhaled 99Tcm-DTPA from lung to blood was measured using a gamma scintillation camera with computer data acquisition. During a single clearance study the subjects voluntarily breathed close to total lung capacity (TLC) and close to residual volume (RV). They breathed at one volume for 5 min, then at the opposite volume for 5 min and finally reverted to the original volume for 5 min with a 1 min pause between each manoeuvre. The order in which each subject performed these breathing patterns was randomized. Tidal volume, respiratory frequency and end expired volume were measured with a water spirometer. When they breathed close to TLC the rate of clearance increased (k = 4.62 +/- 1.03%/min) compared with breathing close to RV (k = 1.96 +/- 0.5%/min). This effect of changing volume was immediately reversible after adopting each new lung volume. There were no significant changes in tidal volume or respiratory frequency between each 5 min period. There was no significant difference between the clearance increased (k = 4.62 +/- 1.03%/min) compared with breathing close to RV (k = 1.96 +/- 0.5%/min). This effect of changing volume was immediately reversible after adopting immediate and reversible.

Administration, Inhalation↗
PubMed1987

Treatment of primary pulmonary hypertension intravenous epoprostenol (prostacyclin).

Ten patients with severe primary pulmonary hypertension and pronounced disability who were unresponsive to oral vasodilators were treated with intravenous epoprostenol (prostacyclin). All had been referred for heart and lung transplantation. Short term administration of epoprostenol (mean dose 5.5 ng/kg/min) increased the mean cardiac index from 1.8 to 2.2 1/min/m2, improved pulmonary artery oxygen saturation from 48% to 57%, and increased calculated tissue oxygen delivery from 10 to 11.8 ml/kg/min. The mean pulmonary vascular resistance fell by 18% while mean systemic artery pressure fell by 32%. Pulmonary artery pressure rose in only two patients. Continued intravenous infusion of epoprostenol for 1-25 months was associated with subjective and clinical improvement. Exercise tolerance improved as measured by an increase in the maximum rate of oxygen consumption during progressive exercise testing. In those six patients who were able to exercise before treatment it rose from a mean of 7 to 15 ml/kg/min. Those who had been unable to exercise before treatment achieved comparable rates of oxygen consumption after treatment. Two patients died on treatment, three have undergone heart-lung transplantation, and in five the treatment is continuing. Complications included episodes of septicaemia and ascites. In this uncontrolled study of patients with severe pulmonary hypertension epoprostenol seemed to offer a means of optimally dosing the patients with a vasodilator to reduce pulmonary vascular resistance and thus increasing cardiac output and oxygen tissue delivery. There was no evidence to suggest that this treatment influenced the progress of the disease.

Adolescent↗
PubMed1985

Does bronchography have a role in the assessment of patients with haemoptysis?

The results of bronchography in 96 consecutive patients investigated for haemoptysis at Papworth Hospital from 1975 to 1983 were reviewed. None of the patients included in this study gave a history suggestive of bronchiectasis and neither chest radiography nor fibreoptic bronchoscopy had shown a cause for the bleeding. Bronchography was performed through the fibreoptic bronchoscope and all included in the study showed both lungs adequately. The chest radiographic appearances were compared with the bronchographic findings. Seven of 12 patients with appearances suggesting old fibrosis showed bronchiectasis, as did eight of 10 with radiographic appearances suggestive of bronchiectasis. Eleven out of 74 patients with normal chest radiographs, however, also showed bronchiectasis. This group of 11 was compared with the other 63 but no clinical feature was found to be significantly associated with the presence of bronchiectasis. Although bronchography is now rarely used in the investigation of haemoptysis, this high yield (15%) of bronchiectasis indicates that its use should be reappraised. Follow up of the patients indicated that bronchography was not reliable at diagnosing peripheral bronchial carcinomas, which became evident later in two cases, and that asthma was present in 15 (24%) of the 63 patients with both normal chest radiographs and normal bronchograms.

Adolescent↗
PubMed1985

Alpha-1-antitrypsin deficiency presenting as bronchiectasis.

We describe three patients with the clinical and radiographic features of progressive bronchiectasis, and without evidence of emphysema, associated with deficiency of alpha-1-antitrypsin. The association of hereditary alpha-1-antitrypsin deficiency and pulmonary emphysema is well recognized (Eriksson 1965). About half of these subjects also have chronic bronchitis as defined by persistent sputum production (Tobin et al. 1983). Bronchographically proven bronchiectasis without apparent emphysema has been reported in only one subject with alpha-1-antitrypsin deficiency (Longstretch et al. 1975).

Aged↗
PubMedDate not supplied

Extracellular flush solution that contains blood, mannitol, albumin, and prostacyclin protects rat lungs from six hours of ischemia.

We have used an isolated rat lung model to compare the quality of preservation of different flush techniques with each other and with topical cooling alone. Lung injury was assessed by recording lung weights after reperfusion after 4 and 6 hours of ischemia. The flush solutions studied were intracellular (Collins-Sacks), traditional extracellular, extracellular with low potassium plus dextran, and extracellular containing blood, mannitol, albumin, and prostacyclin (Wallwork's solution). Flushing with Wallwork's solution before both 4 and 6 hours of ischemia gave superior protection from lung edema after reperfusion over all the other methods.

Albumins↗