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Biomedical subjects

R Clark

Publications and source records attributed to R Clark.

At least 379 records · Page 21Linked to original sources

Utilization of Virginia's hospital emergency departments.

When compared with the results of a statewide study conducted in 1968, these data indicate that the utilization of Virginia's emergency departments has increased substantially both in absolute numbers and on a per capita basis. Consistent with the national pattern, the results of this study suggest that a large proportion of patients who utilize the hospital emergency department are actually seeking care for non-acute conditions. Thus the hospital emergency department and its staff are confronted with the complex and often contradictory task of responding appropriately to growing demands for primary medical care while, concurrently, trying to improve the level of care for patients with acute illness or injuries. The development of workable ways to resolve this dilemma and still ensure that the public has ready access to appropriate medical care at a reasonable cost is one of the major challenges in the health industry today.

Emergency Service, Hospital↗

Bile duct carcinoma mimicking chronic liver disease.

In a case of cholangiocarcinoma involving the bifurcation of the common duct, the association with striking intermittence of jaundice and with signs of chronic liver disease presented a diagnostic enigma. Disappearance of jaundice does not rule out the diagnosis of bifurcation tumors and may be misleading. Adequate demonstration of the biliary tree, best achieved with percutaneous transhepatic cholangiography, is essential for early diagnosis of this entity.

Adenoma, Bile Duct↗

Echocardiographic assessment of the level of cardiac compensation in valvular heart disease.

The level of cardiac compensation in valvular disease was studied by relating echocardiographic and cardiac catheterization measurements. Three groups -- compensated, intermediately compensated, and decompensated -- were defined according to the left ventricular angiographic pattern and cardiac output. The echocardiographic ejection indices, percent left ventricular minor diameter shortening, ejection fraction, and fiber shortening rate were significantly higher than normal in compensated mitral regurgitation, lower then normal in compensated aortic stenosis, and within normal limits in compensated aortic insufficiency. In the decomposed state these indices were depressed. Intermediate compensation was best recognized by combining several echocardiographic variables into an echocardiographic score based on multivariate discriminant function analysis. Thus, the compensated volume overload states (aortic and mitral regurgitation) and pressure overload state (aortic stenosis) have separate sets of "normal" echocardiographic values; low ejection indices characterize the decompensated group, while recognition of intermediate compensation requires analysis of multiple echocardiographic variables.

Adult↗

Amantadine decreases d-amphetamine stimulation and increases d-amphetamine anorexia in mice.

Amantadine hydrochloride (Symmetrel), an antiviral, antiparkinson agent that is most frequently used clinically at oral doses of 2 to 3 mg/kg, significantly decreased d-amphetamine-induced CNS stimulation (motor activity) and simultaneously increased d-amphetamine-induced anorexia (milk intake) in mice. Amantadine did this at oral doses of 2.5 and 5 mg/kg, which alone had no effect on either motor activity or milk intake.

Amantadine↗

Diagnostic accuracy of fiberoptic panendoscopy and visceral angiography in acute upper gastrointestinal bleeding.

Emergency fiberoptic panendoscopy and visceral angiography both had comparable diagnostic accuracy in our series of 55 patients with actively bleeding upper gastrointestinal lesions. The diagnostic accuracy of the barium meal was found inferior to both fiberoptic panendoscopy and visceral angiography. Panendoscopy proved capable of quickly and safely diagnosing site and source of the active bleeding lesion. Visceral angiography requiring additional time, expense and personnel commitment proved an effective back-up procedure when panendoscopy was unsuccessful or contradictions existed. Emergency angiography was well tolerated by gravely ill patients. The therapeutic advantage of angiography with infusion of vasopressin upon completion of the diagnostic study remains to be shown as an advantage over panendoscopy.

Acute Disease↗

Successful surgical correction of an embolized prosthetic valve poppet: case report.

Embolization of a prosthetic valve poppet, a rare complication following valve replacement, has been, until recently, generally fatal. Immediate recognition followed by replacement of the poppet or valve and extraction of the embolized poppet is the only feasible approach. Recently, a patient was seen was seen shortly after the onset of acute pulmonary edema with wide-open mitral regurgitation. A diagnosis of extrusion of the poppet from a previously placed prosthetic valve was confirmed and a successful mitral valve replacement accomplished. The nonradiopaque poppet, subsequently localized by an ultrasound B-sac, was removed from the lower abdominal aorta at a later operation. We believe this to be the second reported case of survival following successful reoperation for embolization of a prosthetic poppet.

Aorta, Abdominal↗

Factor VIII levels during the course of acute hepatitis in a haemophiliac.

A 51-year-old patient with haemophilia since childhood (usual factor VIII level 14%) developed acute viral hepatitis type B two months after an operation which had been covered by cryoprecipitate. The course of the hepatitis following admission was severe with encephalopathy and ascites. Evidence of intravascular coagulation with an increased radioactive fibrinogen turnover was also present. The factor VIII level measured by a one-stage clotting factor assay rose rapidly to 200% of normal and remained at this level for two weeks, and factor-VIII-related antigen as measured by electroimmunoassay also became greatly elevated (900% of normal). The possible mechanisms underlying those surprising changes are discussed.

Antigens↗

67Gallium accumulation in hepatic actinomycosis.

A case of actinomycosis involving the liver is reported. The liver scan with 99mTcS colloid showed multiple areas of focal abnormalities. 67Gallium citrate liver scan showed these areas to concentrate intensely. This pattern of differential hepatic scintigraphy is seen in pyogenic abscesses as well as malignancy of the liver. Actinomycosis may mimic the clinical picture of a malignant neoplastic process, making the differential diagnosis of 67Ga-positive lesions of the liver more difficult.

Actinomycosis↗

A controlled trial of heparin therapy in the coagulation defect of paracetamol-induced hepatic necrosis.

Treatment of the coagulation disturbances developing with hepatic damage following a paracetamol overdose was assessed in a controlled trial of 22 patients, one half being given heparin and fresh frozen plasma and the other fresh frozen plasma alone. No significant difference was observed either in the speed of correction of the coagulation defect or in the clinical outcome. Two-thirds of the patients had evidence of disseminated intravascular coagulation, but despite the presence of a severe coagulation defect, significant bleeding occurred in only five patients. This may be because with paracetamol-induced hepatic necrosis both the coagulation defect (and possibly other features attributable to severe hepatic insufficiency) are of shorter duration than in hepatic necrosis due to causes such as viral hepatitis in which the liver damage may be a continuing process.

Acetaminophen↗