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Biomedical subjects

J D Cooper

Publications and source records attributed to J D Cooper.

At least 235 records · Page 13Linked to original sources
PubMed1989

Airway hyperreactivity in patients undergoing lung and heart/lung transplantation.

To assess airway reactivity in lung transplant patients, three heart/lung, three double lung, and eight single lung transplant patients underwent airway challenge tests. All patients were assessed by methacholine aerosol challenge and thirteen were also assessed by histamine aerosol challenge at least three months after transplant surgery. The airways of patients with bilaterally denervated lungs (heart/lung and double lung transplants) were significantly more reactive to both methacholine and histamine (p less than 0.01) than were the airways of patients with unilaterally denervated (single lung transplants) lungs. Inflammatory changes in the airway mucosal biopsies were minimal in three patients and absent in all others. These studies raise questions about the role of central innervation in the maintenance of normal airway function as well as the mechanisms of action of both methacholine and histamine in causing bronchoconstriction.

Adolescent↗
PubMed1989

Single lung transplantation for severe chronic obstructive pulmonary disease. Washington University Lung Transplant Group.

Single lung transplantation (SLT) has been considered physiologically inappropriate for patients with chronic obstructive pulmonary disease (COPD). It has been postulated that the high static compliance and elevated pulmonary vascular resistance of the native lung functioning in parallel with the more normal allografted lung could cause unacceptable ventilation-perfusion mismatching and/or overinflation of the native lung with encroachment on the expansion of the transplanted lung. While some degree of ventilation-perfusion imbalance may be physiologically obligatory after SLT for COPD, a significant disruption in gas exchange may not occur unless a complication, such as rejection or infection, arises in the transplanted lung. A 60-year-old man with COPD who underwent successful SLT is presented and discussed. In spite of scintigraphic evidence of ventilation-perfusion mismatching between the native lung and the allograft during the first six postoperative weeks, the recipient had normal resting gas exchange on room air after the second postoperative week. Fourteen weeks after transplantation, his maximum oxygen uptake was 37.3 percent of the predicted maximal value, and no evidence of ventilatory limitation was detected. His functional status and lifestyle have been markedly improved by SLT. The role of SLT for COPD should be reconsidered. It may be a reasonable transplantation alternative for selected patients with COPD who are not candidates for double lung transplantation (DLT).

Exercise↗
PubMed1989

A method for safe twelve-hour pulmonary preservation.

The clinical application of lung transplantation is severely limited by the shortage of suitable donor organs. Current techniques of lung preservation allow a maximum of 4 to 6 hours of safe ischemic time. The function of canine left lung allografts stored for 12 hours after being cooled by pulmonary artery flush was studied. Two types of flush solution were used: group I; Euro-Collins solution; group II, low-potassium-dextran solution. Lung function was studied immediately and 3 days after transplantation. This protocol enables study of acute preservation-related lung injury and the delayed manifestations of ischemic and reperfusion injury after a 3-day period of recovery. Inflatable cuffs were placed around each pulmonary artery at operation and were attached to subcutaneous injection ports. Temporarily occluding either pulmonary artery allowed independent study of the native or transplanted lung. Using this model, we were able to demonstrate reliable and reproducible preservation of lungs for 12 hours. The low-potassium-dextran solution provided significantly better immediate function of the preserved lung than the Euro-Collins solution: arterial oxygen tension 509 +/- 15 mm Hg versus 111 +/- 16 mm Hg (p less than 0.0001). Function on the third day was excellent for both groups. Pulmonary artery pressure, pulmonary vascular resistance, and carbon dioxide tension were not significantly different between the groups immediately or on day 3.

Animals↗
PubMed1989

Endoscopic infertility surgery.

Since the introduction of endoscopy by Jacobaeus in 1910, there has been a dramatic change in the pattern of and approach to the diagnosis and treatment of various diseases of the female reproductive organs. The advances in techniques of operative endoscopy, in high technology and in instrumentation (such as endoscopes, video cameras and videomonitors) have made it possible to perform laparoscopically many of the infertility-related procedures previously requiring laparotomy. The advantages of such surgery are the rapid recovery time, decreased time lost from work, smaller scars, reduced cost, avoidance of risks and complications of laparotomy, and, perhaps, better results.

Adnexal Diseases↗
PubMed1988

Automated sequential trace enrichment of dialysates and robotics. A technique for the preparation of biological samples prior to high-performance liquid chromatography.

The development of the sample preparation process, the automated sequential trace enrichment of dialysates, in association with a cartesian robotic sampler is described. The system has been applied to the total automation of the preparation of biological samples and high-performance liquid chromatographic analysis. Concepts of the technique are reported together with an examination of its application to free and total analyte estimation. Examples of chromatographic separations obtained from the preparation of a variety of different analytes and sample materials are given.

Amino Acids↗
PubMed1988

Histologic and hemodynamic investigation on canine lung allografts.

Histologic and hemodynamic investigations were performed on 26 mongrel dogs that underwent left lung allotransplantation. All dogs received cyclosporin A and azathioprine as immunosuppressants and were divided into two groups. In the 10 Group I dogs, no preservation was performed and the animals were followed until death. The 16 Group II dogs were subdivided into two groups; Group II-A dogs received the transplantation after 6 hours preservation and Group II-B dogs received it after no preservation. All dogs in Group II were sacrificed within 14 days following the transplantation. Seven of the dogs in Group I survived for over 90 days. The major histologic findings of Group I were pneumonitis, fibrotic interstitial changes and pleural thickening. Atypical pneumocytes were observed in three dogs, however structural changes of the bronchioles, suggesting obliterative bronchiolitis, were obscure. In Group II, 75 per cent of the dogs demonstrated the histologic features of rejection and early rejection was seen in a few dogs. Under electron microscopy, vascular wall damage was indicated by swollen endothelial cytoplasm and disrupted basement membranes. Small lymphocytes accumulating around the vessels showed lymphoblastic figures with rich intracytoplasmic organellae. The mean pulmonary arterial pressure measured by right pulmonary artery (PA) occlusion was elevated just after the transplantation in Group II, but decreased on the 7th day. The mean PA was again elevated on the 14th day in those dogs in which diffuse mononuclear cell cuffing was demonstrated. We consider that the PA-occlusion test can be used for determining the degree of rejection.

Animals↗
PubMed1988

Complement-mediated pulmonary edema in sheep.

Incubation of plasma with zymosan results in complement activation. Infusion of zymosan-activated plasma (ZAP) into the pulmonary circulation in sheep results in a transient rise in pulmonary vascular resistance, accompanied by hypoxemia. This is associated with production of the vasoactive prostaglandin metabolite, thromboxane. We hypothesized that ZAP infusion caused pulmonary edema and may transiently alter pulmonary permeability to protein. Two sets of experiments were conducted involving six sheep. Three sheep underwent open lung biopsies during ZAP infusion, and electron microscopy documented early reversible interstitial pulmonary edema in response to ZAP infusion. Three other sheep were prepared with lung lymph fistulae and subjected to a similar infusion of ZAP. These studies documented a rapid rise in lymph flow and lymph protein clearance, occurring immediately upon infusion of ZAP. These experiments demonstrate a rapid reversible interstitial edema in sheep lung in response to ZAP infusion and suggest that permeability to protein may be transiently altered as a result of this injury.

Animals↗
PubMed1988

An improved technique to facilitate transcervical thymectomy for myasthenia gravis.

We have used the transcervical method of thymectomy in patients with myasthenia gravis and believe that complete thymectomy is accomplished with minimum morbidity. For the past eight years we have used an improved technique for the transcervical approach, employing a specially designed sternal retractor that permits improved visualization of the anterior mediastinum. We have reviewed 65 patients operated on between 1977 and 1986. Patients were assessed using a modified Osserman classification (0 = asymptomatic; 1 = ocular signs and symptoms; 2 = mild generalized weakness; 3 = moderate generalized weakness; 4 = severe generalized weakness, respiratory dysfunction, or both). The mean grade for all patients at the time of thymectomy was 2.7. At most recent follow-up, the mean clinical grade was 0.5. In addition, 85% of patients were free of generalized weakness, 95% had improved by at least one grade, and 86% had improved by two or more grades. Comparing these results with those reported following thymectomy through a sternotomy reveals that the transcervical approach gives equivalent results.

Adolescent↗
PubMed1988

Technique of successful clinical double-lung transplantation.

Lung transplantation has become a successful method in the therapy for end-stage pulmonary disease. While single-lung transplantation provides benefit to patients with pulmonary fibrosis, bilateral lung transplants are required for septic or emphysematous lung disease. We describe the technique employed in 6 patients to transplant en bloc both lungs with the recipient heart left in place. The lungs are connected by a left atrial cuff, main pulmonary artery, and trachea. The completed implantation has a tracheal anastomosis securely wrapped in omentum, a left atrial anastomosis posterior to the heart, and a pulmonary artery anastomosis anteriorly. Airway ischemia resulted in the death of 1 patient. This procedure allows complete excision of all diseased pulmonary tissue, retention of the recipient's own heart, and separate excision of the donor heart for use in another recipient, thereby markedly increasing the supply of donor lungs for transplantation.

Adolescent↗
PubMed1988

Separate extraction of cardiac and pulmonary grafts from a single organ donor.

The scarcity of multiple-organ donors for perfused organ transplantation requires cooperation between various transplanting teams to maximize organ retrieval. We have developed a technique for the extraction of a cardiac and separate pulmonary graft from the same donor. These grafts can then be successfully implanted into two separate recipients. Our experience with 9 successful extractions and implantations is recorded.

Anastomosis, Surgical↗
PubMed1988

Status of lung transplantation.

Selected patients with terminal lung disease have been managed effectively by lung transplantation. Strict selection criteria for donors and recipients, attention to technical detail, and avoidance of perioperative corticosteroids increase the likelihood of success. The underlying pulmonary disease determines the appropriate procedure. Single-lung transplantation is most appropriate for patients with pulmonary fibrosis. Patients with emphysema or septic pulmonary disease who have adequate or recoverable cardiac function can be well served by double-lung transplantation. However, such patients are still treated in some centers by combined heart-lung transplantation. Patients with right-heart failure secondary to vascular or parenchymal pulmonary disease are best managed by combined heart-lung transplantation. Donor availability, airway healing, and diagnosis of rejection remain significant problems and are the focus of experimental and clinical investigation in many centers.

Graft Rejection↗
PubMed1988

Alterations in regional catecholamine content and turnover in the male rat brain in response to in utero ethanol exposure.

Fetal ethanol exposure is known to produce CNS abnormalities. The molecular basis for these manifestations observed in animals exposed to ethanol in utero may be explained by changes in regional catecholamine content and turnover. This study was designed to determine changes in catecholamine content and turnover in the cerebral cortex, cerebellum, medial basal hypothalamus, diencephalon, and septal area of male rats exposed to ethanol pre- and postnatally. Pregnant Sprague-Dawley rats were exposed to either an ad libitum liquid diet containing 35% ethanol-derived calories, an isocalorically matched liquid diet, or a diet consisting of laboratory chow and water. Regional alterations in catecholamine content and turnover in each of the brain areas were observed on postnatal Day 18. A regional variability was demonstrated in the effect of in utero ethanol exposure on catecholamine content and turnover. The most dramatic effect was found in the dopaminergic neurons of the medial basal hypothalamus where in utero ethanol exposed offspring had a significantly reduced DA content and turnover when compared to pups from both isocalorically matched and chow-fed dams. These data indicate that the dopaminergic neurons of this particular brain region are susceptible to alteration by ethanol exposure during development and that this alteration cannot be explained by changes in nutrition alone.

Animals↗
PubMed1988

Why the assay of serum cystine by protein precipitation and chromatography should be abandoned.

The higher bias of serum cystine estimations by a HPLC method compared with those by ion exchange techniques is shown to be largely due to differences in the sample preparation procedures of the two techniques. The ion exchange methods utilised sulphosalicylic acid serum protein precipitation and post-column ninhydrin derivatisation of cystine, whilst the high pressure liquid chromatography technique employed automated dialysis for removal of proteins and pre-column ortho-phthalaldehyde derivatisation of cystine after its conversion to cysteine and then to S-carboxymethylcysteine. Examination of these procedures showed that whilst the high pressure liquid chromatographic method accurately estimates total serum cystine and cysteine, many factors affect the precision and accuracy of serum cystine estimations using the ion exchange techniques. In particular, serum protein precipitation techniques that are currently employed for the preparation of samples for cystine analysis by ion exchange chromatography should be abandoned.

Blood Proteins↗