Biomedical subjects
Publications and source records attributed to D R Jones.
Myxomas occur most commonly in the left atrium arising from the fossa ovalis. We report the case of a left atrial myxoma originating from the base of the right inferior pulmonary vein. This large myxoma filled a large secundum atrial septal defect, which was diagnosed intraoperatively. The unusual position of this myxoma and operative management of the associated atrial septal defect are discussed.
Success in neonatal lung transplantation depends on the growth of the transplanted lung. To study the effects of transplantation and denervation on primate lung growth without rejection or immunosuppression, an autotransplant model was chosen. Eight-week-old baboons underwent left lung autotransplantation (n = 5) or sham operation (n = 1). At age 13 weeks and 9 months, single lung volumes were calculated by nitrogen washout and computed tomography. Results were compared with those of 4 unoperated weight-matched controls (2 per age group). Over the growth period, mean total lung capacity in operated baboons increased 82% (137 to 249 mL) by nitrogen washout and 70% (182 to 309 mL) by computed tomography compared with 85% (128 to 237 mL) and 74% (141 to 245 mL) for the sham-operated baboon, respectively. Transplanted left lung volume increased 91% (53 to 101 mL) by nitrogen washout and 75% (68 to 119 mL) by computed tomography compared with 85% (54 to 100 mL) and 80% (56 to 101 mL) for the sham-operated baboon, respectively. In the absence of rejection and immunosuppression, normal volume growth occurs in the transplanted infant primate lung.
A 49-year-old man with unstable angina and a history of severe anaphylaxis to seafood and intravenous iodine needed myocardial revascularization. Because of concern of an intraoperative protamine reaction, preoperative treatment was instituted with steroids and with H1 and H2 blockers. Revascularization was accomplished using a heparin-coated cardiopulmonary bypass circuit. Complement activation and postoperative bleeding were minimal. Heparin-coated cardiopulmonary bypass is a safe, effective technique of bypass in select patients.
The advent of video-assisted thoracic surgical procedures has caused many thoracic surgeons to reevaluate their approach to the management of diseases of the chest. The management of traumatic thoracic injuries is an area in which thoracoscopic techniques may have significant impact. The current role of thoracoscopy in the diagnosis and therapy of thoracic trauma continues to evolve. This review considers the currently accepted diagnostic and therapeutic applications of thoracoscopy in the management of these patients. The technique of thoracoscopy as it applies to the trauma patient is also discussed, as well as the future and expanding applications of thoracoscopy in this setting.
Thoracic procedures once requiring open thoracotomy are now being performed with video-assisted thoracoscopy. To visualize adequately the intrathoracic structures, creation of an artificial pneumothorax by carbon dioxide insufflation under positive pressures has been advocated. We hypothesized that positive-pressure insufflation during thorascopy would cause significant hemodynamic compromise. Eight healthy female pigs underwent general endotracheal anesthesia and placement of monitoring lines. After placement of a thorascope, baseline hemodynamic measurements were obtained at 0 mm Hg (atmospheric pressure). Measurements were taken randomly at 5, 10, and 15 mm Hg using carbon dioxide insufflation after stabilization at each pressure. Data were analyzed using Page's test for noparametric variables. Insufflation pressures of 5 mm Hg or greater resulted in significant decreases in cardiac index, mean arterial pressure, stroke volume, and left ventricular stroke work index, whereas central venous pressure increased (p < 0.001). Changes in heart rate were not significant. We do not recommend routine positive-pressure insufflation during thorascopy because of the significant hemodynamic compromise in our experimental model.
The papain test, which detects incomplete anti-red blood cell (RBC) autoantibodies in serum, was positive in 12 out of 16 anaemic dogs. Positive results were significantly correlated (chi 2 = 11.1, P < 0.001) with increased levels of RBC-bound immunoglobulin, but in three of these cases it was considered that a diagnosis of autoimmune haemolytic anaemia could not be justified. Furthermore, enzyme-linked antiglobulin test measurements of RBC-reactive serum IgG were increased in only three of the dogs with a positive papain test. Papainised canine RBC did not consistently take up more serum IgG than untreated cells in an indirect enzyme-linked antiglobulin test. However, the zeta potential of the RBC was reduced after enzyme treatment, and electrophoretic analysis revealed that glycophorins, which bear a strong negative charge, were cleaved from the cell membrane. It is concluded that a positive papain test alone is not reliable in the diagnosis of canine autoimmune haemolytic anaemia and that the enzyme increases the agglutinability of RBC by reducing the mutually repulsive electrostatic forces between the cells, rather than by increasing the amount of autoantibody bound.
Acute hyperosmolality in the Pekin duck results in an extracellular acidosis and hypercarbia without any stimulation of ventilation. The development of the extracellular acidosis is accompanied by the concurrent development of an intracellular alkalosis systemically which has been hypothesized to depress ventilation (Kasserra et al., J. Appl. Physiol., 1993). In order to investigate this apparent suppression of ventilation, the ventilatory response to various respiratory challenges (CO2, O2, K+) was studied both before (normosmotic) and after (hyperosmotic) hypertonic sucrose infusion. Increased plasma osmolality caused a significant drop in arterial pH of 0.06 +/- 0.01 units and a 4 Torr increase in PaCO2, yet did not stimulate any significant increase in ventilation despite a significant increase in oxygen consumption. Acute hyperosmolality increased the PaCO2 associated with resting ventilation, and decreased the magnitude of the ventilatory response to a given increase in PaCO2, compared with the response to the same ventilatory challenge in normosmotic animals. Acute hyperosmolality increased the ventilatory response to hypoxia and K+ compared with normosmotic animals. The opposite effect of hyperosmolality on the ventilatory responses to hypercapnia compared with hypoxia suggests that the mechanisms of chemoreception for hypercapnia and hypoxia are different. The depressed ventilatory response curve to increased PaCO2 and decreased arterial pH during hyperosmolality, both alone and during the hypercapnic challenge, suggests that the peripheral chemoreceptor response to pH and CO2 is suppressed. It is hypothesized that the suppression results from the intracellular alkalosis occurring during acute hyperosmolality.
It is generally considered that the clinical manifestations of human and canine systemic lupus erythematosus (SLE) are similar in many respects. However, there are differences in serological markers of SLE between the two species, which has led to much discussion on which immunopathological criteria might be appropriate in the diagnosis of the canine disorder. Further studies on canine SLE will need to address these issues, so that definitive diagnostic indices may be employed. Areas which require to be re-assessed, in particular, include the applicability of assays for antibodies to double-stranded DNA--a hallmark of human SLE, a re-evaluation of the anaemia associated with canine SLE and an index of the clinical activity of the disease process.
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The neuromuscular control of the glottis, a muscular sphincter that controls air flow to and from the swim bladder, was investigated using in vitro preparations from bowfin (Amia calva). Stimulation of the ramus intestinalis branch of the vagus nerve caused an increase in isometric tension of the glottal musculature, indicating active closure. The glottis could be actively opened only by direct stimulation of muscle bundles lying lateral to the glottis. In 19 of 24 preparations supramaximal nerve stimulation (20 Hz, 10 V) caused a two-phase increase in muscle tension. Immediately after the onset of stimulation there was a rapid increase in muscle tension. After the end of the train of stimuli, the tension decreased and then again increased briefly followed by a slow return to baseline lasting approximately 60 s. The addition of hyoscine reduced maximum tension of the response by 63 +/- 7% and abolished the second slower element of the response to vagal stimulation. The remaining faster response to nerve stimulation was abolished by tubocurarine. Applied acetylcholine or carbachol mimicked the slow response, causing a slow-onset sustained contraction that was abolished by hyoscine. Hence, the musculature showed physiological characteristics of both skeletal and smooth muscle. Histological examination of the glottis confirmed the physiological results: smooth muscle fibers were found lining the pneumatic duct and lumen of the glottis arranged in a circular fashion around the lateral margins of the glottis. Distinct skeletal muscle bundles were found lateral to the smooth muscle and also arranged in parallel with the glottal lumen, forming a skeletal muscle sphincter.(ABSTRACT TRUNCATED AT 250 WORDS)
The histological and transrectal ultrasound (TRUS) appearances at corresponding sites of the periphery of the prostate gland have been compared in 30 benign and 27 malignant glands taken at autopsy. In the benign series, the histological capsule was frequently absent and correlated poorly with the consistent TRUS findings of a regular, well-defined 'ultrasonic capsule'. It is concluded that 'the capsule' should be replaced as a tumour-staging landmark by a more realistic terminology. Carcinoma may be described as intra- or extra-prostatic, or confined or unconfined with respect to the gland. In the malignant glands, there was no correlation between morphologically unconfined cancers and irregular or absent ultrasound 'capsule' when corresponding areas were compared. This disparity must contribute to an underestimation of tumour extent with TRUS.
The effects of retroperitoneal lymphadenectomy on ejaculation have been examined in 186 patients who had removal of residual masses after chemotherapy for metastatic non-seminomatous germ cell tumours. The results were analysed for significance using a chi 2 test of independence. Forty-one men (22%) permanently lost ejaculation postoperatively. The larger the size of the mass removed, the more likely the patient was to have ejaculatory failure (< 4 cm = 4%, 4-8 cm = 17%, > 8 cm = 58%; p < 0.005). Removal of bilateral masses was more likely to result in loss of ejaculation than unilateral masses (45 and 12%, respectively, p < 0.005). There has been significantly less postoperative ejaculatory dysfunction since 1984 when a nerve sparing dissection was introduced (before 1984 36%, since 1984 16%, p < 0.005). The incidence of ejaculatory dysfunction following retroperitoneal lymphadenectomy is therefore determined by the size and position of residual lymph node masses after chemotherapy and can be kept to a minimum by a careful nerve sparing operative technique.
The diagnosis and treatment of intrathoracic disease often requires open thoracotomy. Patients who are immunocompromised, have poor pulmonary function, or have coronary artery disease may not tolerate this procedure well. With the advent of small video cameras, fiberoptics, and compatible instrumentation, thoracoscopy is now a viable option to open thoracotomy. This procedure is being performed with increasing frequency, and has achieved excellent results. The intrathoracic image, which previously was only available to the operating surgeon, is captured by a small video camera on the end of the scope. The image is projected simultaneously on several television monitors in the operative suite so that all members of the operative team can see exactly what the surgeon sees. By using such technologies, intrathoracic diagnostic and therapeutic procedures, which previously required some type of open thoracotomy, may now be performed through several small ports placed through diminutive surgical incisions. This article describes three case reports which demonstrate some of the successful applications of video-assisted thoracoscopy, and reviews the diagnostic and therapeutic indications for video-assisted thoracoscopy.
The ability to resist fluid penetration was measured in body fabric and forearm seams of standard and reinforced non-woven disposable theatre gowns. Six standard use, non-woven gowns showed water strike-through in the body area at pressures ranging between 12.1 +/- 0.8 cmH2O and 23.2 +/- 2.2 cmH2O (means +/- 95% confidence interval). Two products resisted fluid penetration of the forearm seam at pressures similar to that of the fabric alone (16.8 +/- 1.0 cmH2O and 18.6 +/- 0.9 cmH2O respectively) but other standard gowns leaked at significantly lower pressures (range 4.6-6.9 cmH2O). (P < 0.05, Mann-Whitney U test). Six of seven high-protection gowns proved fluid resistant at a pressure in excess of 50 cm in the reinforced body zone but four reinforced gowns leaked at stitched arm seams at a pressure of less than 10 cmH2O despite an inner impermeable layer of fabric covering the forearm. Three gowns with heat or adhesive sealed reinforced arm seams resisted fluid penetration up to a pressure of 50 cmH2O. Standard gowns and some reinforced gowns do not offer full protection against forearm contamination through stitched seams. A gown with sealed seams and impermeable fabric should be chosen for high-risk cases.
One hundred six astronaut applicants who had passed initial screening were evaluated for Axis I and Axis II DSM-III-R diagnoses using a structured psychiatric interview. Nine of 106 candidates (8.5%) met diagnostic criteria for six Axis I (including V-code), or Axis II disorders. The use of the NASA structured interview was effective in identifying past and present psychopathology in a group of highly motivated and healthy astronaut applicants. This was the first time that a structured interview had been used in such a setting for this purpose. The methodology described is applicable to any situation where the presence or history of psychopathology requires evaluation for job selection (e.g. pilot selection).
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Systemic lupus erythematosus (SLE) occurs in human beings and in dogs. There is evidence to suggest that the disease is caused by a transmissible factor that may cross the species barrier. We investigated this possibility by looking for autoantibodies and serum protein abnormalities in serum samples from 15 pet dogs owned by patients with SLE and comparing results with those obtained with serum from 10 healthy dogs kept in a controlled environment and 9 dogs with autoimmune diseases. We used standard immunological assays modified for use with canine samples. Compared with the normal dogs, increased amounts of antibody to double-stranded DNA were found in serum from the SLE patients' dogs (median optical density [405 nm] = 0.117 vs 0.299; p = 0.0001), this latter amount being similar to that found in serum from the autoimmune group (0.201; p = 0.6). Abnormal serum protein electrophoresis patterns were found in samples from the autoimmune and SLE patients' dogs but not the normal dogs. These findings support the idea that exposure to common environmental factors or transmissible agents may have a role in causing SLE.
POSSUM and APACHE II scores from 117 consecutive admissions to a high-dependency unit after major surgery were correlated with 30-day morbidity and mortality rates. Thirteen patients (11 per cent) died and 59 (50 per cent) developed a postoperative complication. Receiver-operating characteristic curve analysis showed POSSUM to have good predictive value for mortality (area under curve 0.75) and morbidity (area under curve 0.82). APACHE II scores had a significantly inferior predictive value for mortality (area under curve 0.54) (P < 0.002). POSSUM was superior to APACHE II in prediction of mortality in patients admitted to a high-dependency unit after general surgery. Prediction of postoperative complications by POSSUM is accurate and may be useful for audit.