Biomedical subjects
Publications and source records attributed to J D Collins.
This is a case presentation of pelvic fused kidneys as demonstrated by intravenous pyelogram and magnetic resonance imaging (MRI). The authors wish to stress the importance of anatomical imaging with MRI in the coronal plane. No reconstruction is required as with computerized tomography.
Invasive procedures of the chest in radiology require anatomical awareness of variations in thoracic rib anomalies. The "sloping rib" is a descriptive term the authors use to describe an entity that may present a problem when attempting to remove fluid from the pleural space and/or tissue from the lung. The anomaly has been observed in muscle-wasting disorders, severe osteoporosis, metabolic diseases, and in idiopathic scoliosis of the thoracic spine. The significance to patient care and diagnosis will be discussed.
Forty-five computerized tomographic (CT) chest studies were performed on workers suspected of having pleural disease after being exposed to asbestos material. Ten of the 45 reviewed were court cases, and 32 workers acutely exposed at University of California-Los Angeles (UCLA) were studied with routine four views of the chest. CT confirmed the initial interpretation of chest films obtained at UCLA.
Abnormal thromboscintigrams were observed in patients with lymphatic obstruction. This syndrome was reproduced by surgically ligating the lymphatic drainage of the lower extremity of a dog prior to thromboscintigraphy.
Thrombocytopenia in cirrhotic patients is usually attributed to splenic pooling whereas in idiopathic thrombocytopenic purpura it is related to platelet bound immunoglobulin (PA-IgG). Since primary biliary cirrhosis (PBC) is an autoimmune disorder we have undertaken a prospective study to assess the frequency and possible relationship of PA-IgG to thrombocytopenia in this condition. Sixty-two primary biliary cirrhosis patients (28 precirrhotic; 34 cirrhotic) were studied. Twenty-five patients (40%) had raised PA-IgG of whom 18 had cirrhosis. There was a significant inverse correlation between platelet count and PA-IgG (p less than 0.001) and between platelet count and spleen size (p less than 0.001). Thrombocytopenia (platelets less than 100 X 10(9)/l) was found in nine patients (15%); all nine had raised PA-IgG and eight were cirrhotic with an enlarged spleen. Two cirrhotic patients with persistent thrombocytopenia and bleeding episodes were treated with prednisolone and showed a useful therapeutic response. These results suggest that immune mediated platelet destruction and splenic pooling of platelets may both play a part in the thrombocytopenia observed in primary biliary cirrhosis.
A series of 248 consecutive patients undergoing cardiac surgery were examined in a prospective study of post-transfusion hepatitis in a single British centre. Patients received a total of 1796 units of blood or blood products (mean blood transfusion 6.28 units per patient). During five to 30 days after operation 38 of the patients showed an increase in serum transaminase activities. There was no serological evidence for fresh infection by hepatitis A or B virus, cytomegalovirus, Epstein-Barr virus, or herpes virus in any of these patients. The increase in transaminase activities was unexplained and reached over 100 IU/l (normal less than 40 IU/l) in six patients. The incidence of acute short incubation post-transfusion non-A, non-B hepatitis was therefore thought to be 2.4%. These six patients had normal liver function six months after transfusion but a further two of the surviving 228 patients had raised serum transaminase activities at six months. In one of these, liver biopsy disclosed chronic persistent hepatitis; in the other, alcoholic liver disease was suspected. The incidence of significant chronic liver disease after blood transfusion possibly attributable to a non-A, non-B hepatitis agent was therefore only 0.4%.
In a prospective study of 248 consecutive patients undergoing cardiopulmonary bypass surgery, early postoperative "post-pump" jaundice (PPJ) developed in 49 (20%). Development of PPJ was strongly associated with a bad outcome; 25% of jaundiced patients and 1% of non-jaundiced patients died in the postoperative period. The jaundice was a conjugated hyperbilirubinaemia, and was detectable in 48 out of 49 patients by postoperative day 2. Hypotension, hypoxia, and hypothermia ("shocked liver") were not associated with the development of PPJ, nor was evidence of haemolysis or heart-failure. Although PPJ was significantly associated with multiple valve replacement, higher transfusion requirements, and longer cardiopulmonary bypass time, it also occurred in patients undergoing uncomplicated operations. It is suggested that PPJ is caused by a defect in hepatic excretion of bilirubin.
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A case of nodular pulmonary amyloidosis with Sjögren's syndrome is presented. A search of the literature failed to reveal any such case in which pulmonary nodules progressively calcify.
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Twenty-seven patients with a history of asbestos exposure were reviewed at the UCLA Medical Center in December 1981. All patients were referred by the United States Department of Labor. The patients were told they had asbestosis on the basis of their history of exposure and chest radiographs taken at a local asbestos screening program and initially interpreted by a "B" reader. None of the 27 patients reviewed were found to have evidence of asbestosis either clinically or radiographically. The false-positive radiographic interpretations were due to the extrathoracic musculature (serratus anterior) mimicking intrathoracic disease. Since the study described here was done, an additional 330 patients have had their radiographs reviewed.
Predictive heat transfer equations have been developed to estimate the local supplementary heating necessary to support a resting diver. These formulations consider the diver's passive thermal protection in the form of a diving dress and the effects of his ambient environment upon the dress thermal resistance. The mathematical model performs a numerical analysis on discrete regions comprised of the skin, dry protective suit, breathing gas mixture and the surrounding fluid environment. The parametric properties associated with the heat transfer correlations were obtained from validated experimental heat flux and skin temperature data collected under specific environmental conditions. The supplementary heating required to maintain a diver is obtained by determining the heat flux that would be lost were he not heated and subtracting from this the normal heat flux expected from a resting euthermic subject. Applying this principle to each of the regions, it is possible to predict the supplementary heating necessary to compensate for an excessive flux.
Current agents for lymphoscintigraphy have limitations because of slow migration of the colloidal tracers from the injection site and the unknown effect of phagocytosis on the removal of the labeled particles. The usefulness of Tc-99m dextran (TcDx) with a molecular weight of 110,000 has been tested for lymphoscintigraphy. Computer-assisted dynamic imaging and serial blood sampling in 13 dog experiments demonstrated that the tracer cleared only by lymph drainage from an interstitial injection site. Following interdigital injection of 1.0 ml (0.5-5.0 mCi), TcDx reached the knee or elbow lymph nodes in 12.4 +/- 6.5 (1 s.d.) sec, and the inguinal or axillary lymph nodes in 98.0 +/- 42.3 sec. It cleared from the injection site with a half-time of 31.5 min. In a dog with surgically induced lymphedema, tracer migration was markedly delayed in the edematous leg and the radionuclide lymphoscintigram resembled the contrast lymphangiogram. Initial studies in man yielded high-quality radionuclide lymphograms of the leg, and the pelvic and paraaortic lymph nodes. We conclude that TcDx is very promising for lymphoscintigraphy.
A series of linear algebraic equations have been derived from those of Kerslake (Flying Personnel Research Committee Memo 213, R.A.F. Institute of Aviation Medicine, 1964) for predicting the regional skin temperatures of a quasi-euthermic diver having pronounced vasoconstriction. The equations were developed by numerically analyzing twelve regional skin temperatures recorded from five resting subjects exposed to a hyperbaric chamber environment of 20 degrees C, 95% helium, and 5% oxygen pressurized to the equivalent of 200 msw (650 fsw). The independent variable of the basic correlation is an arbitrarily defined mean skin temperature; the empirical equations were developed for the purpose of assisting a designer in estimating regional supplementary heating requirements for a diver wearing a thermal protection garment of known composition. The developed equations were authenticated by comparing the predicted normalized regional temperature with the respective experimental normalized temperature obtained from several set of physiological data collected during the evaluation of the Naval Coastal System Center's diver thermal protecting garment (DTP). The results of these comparisons of nondimensionalized temperatures indicated that the derived correlations should accurately predict the skin temperature of the principal regions as a function of mean skin temperature with a normal error of no more than 15%.
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When a bone scan reveals an abnormal radionuclide accumulation and the cause is uncertain, bone biopsy is sometimes necessary. One hundred thirty biopsies have been performed in our institution with a percutaneous needle guided by fluoroscopy. This procedure is safe and effective.