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K J Chun

Publications and source records attributed to K J Chun.

17 recordsLinked to original sources
PubMed2005

'Shine through' on dual tracer parathyroid scintigraphy: a potential pitfall in interpretation.

Dual tracer scintigraphy has become the procedure of choice for preoperative localization of parathyroid adenomas. The typical protocol used by most laboratories is to initially perform a Tc-99m sestamibi (MIBI) study with early and delayed (2-3 hours) washout phase images. This is followed by a thyroid-specific Tc-99m pertechnetate study. A potential pitfall exists if the delayed phase of the initial MIBI study shows an intense, abnormal focus of retention. This focus may interfere with interpretation of the subsequent pertechnetate study because of a "shine through" effect. To differentiate a parathyroid adenoma from a thyroid adenoma, it may be necessary to repeat the thyroid-specific pertechnetate scan on a separate day after the dual tracer study.

Adenoma↗
PubMed2001

Flail aortic valve and acute aortic regurgitation due to spontaneous localized intimal tear of ascending aorta.

This report describes the transesophageal echocardiographic findings of acute severe aortic regurgitation resulting from localized transverse intimal tear of ascending thoracic aorta which could not be suspected as a cause of flail aortic valve preoperatively. In patients with chest pain and acute aortic regurgitation associated with flail aortic valve, localized intimal tear of aorta should be considered as a possible cause of flail aortic valve.

Aortic Rupture↗
PubMed2001

Survival and prognostic factors in patients with primary pulmonary hypertension.

OBJECTIVES: Primary pulmonary hypertension (PPH) that affects predominantly young and productive people is a progressive fatal disease of unknown cause. The objectives of this study were to characterize mortality in patients with PPH and to investigate the factors associated with their survival. METHODS: Thirteen patients with PPH were enrolled between 1988 and 1996 and followed-up through July 1999. Measurements at diagnosis included hemodynamic and pulmonary function variables in addition to information on demographic data and medical history. RESULTS: 1) The mean age of the patients with PPH enrolled into the study was 36.1 +/- 9.3 years with female predominance. 2) The estimated median survival was 3.4 +/- 0.6 years. 3) Decreased cardiac index was the only significant predictor of mortality (Cox proportional hazards model). CONCLUSION: Patients with PPH have a poor survival expectancy. In this limited study with a small number of patients, mortality is largely associated with decreased cardiac index.

Adult↗
PubMed2000

Apoptosis in dilated cardiomyopathy.

OBJECTIVE: Cardiomyopathy, a popular diagnosis that always obscures more than it reveals, nevertheless has several characteristic histological features. These prominently include widespread focal myocardial fibrosis and associated hypertrophy of surviving cardiac myocyte. In fact, focal noninflammatory degeneration (not necrosis) has been demonstrated as a feature of many forms of cardiac hypertrophy. We hypothesized that this loss of myocardial cells in dilated cardiomyopathy (DCMP) may result from cell death by apoptosis. METHODS: Endomyocardial biopsy specimens from the right ventricles of six patients who suffered from DCMP were studied, and myocardial specimens from two persons who died in motor vehicle accidents were used as negative controls. For identification of apoptosis, immunohistochemistry with terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end-labeling was performed. In addition, apoptosis was confirmed morphologically by confocal laser scanning microscopy with propidium iodide. RESULTS: Apoptosis, that was represented by an apoptotic index ranging from 19.8 to 25.4%, could be extensively seen in myocytes and also rarely in non-myocytes of interstitium and vascular endothelium. Morphologically, there were a lot of nuclei with clumps of condensed chromatin, suggestive of apoptosis. CONCLUSION: The present study demonstrated that myocyte loss in DCMP might be mainly due to the apoptosis of myocytes and interstitial cells, rather than inflammation or cell necrosis.

Adult↗
PubMed1999

Radionuclide renal scan findings in rupture of the ureter: a case report.

Radionuclide renal scan findings in a patient with iatrogenic rupture of the ureter are reported. Although the literature contains reports of the radionuclide scan in rupture of the ureter from other causes, this, to our knowledge is the first description of the scan findings in iatrogenic rupture.

Aged↗
PubMed1996

Exercise renography in untreated subjects with essential hypertension.

UNLABELLED: Exercise induced renal dysfunction is reported to occur in treated hypertensive patients but not seen normotensive subjects. It is unclear if this phenomenon is related to the disease or to treatment. METHODS: Four normal volunteers and 15 hypertensive subjects (antihypertensive medications were discontinued for more than 4 wk) were studied with upright radionuclide renography at rest and during bicycle exercise. The amount of exercise was sufficient to increase the heart rate at least 20 bpm above the resting value. All subjects were healthy, without evidence of left ventricular hypertrophy renal disease or hypertensive retinal disease. BUN, serum creatinine concentration and urinalysis were normal in all subjects. Renograms were performed for 12-15 min after injection of either 1 mCi[123]orthoidohippurate (OIH) or 2-7 mCi 99mTc-mercaptoacetyltriglycine (MAG3). Visual analysis and mean transit time calculation were performed on the rest and exercise studies. RESULTS: Seven of 14 hypertensive subjects and none of the normal volunteers demonstrated abnormal prolongation in renal transit during exercise which was not seen on the resting renogram. Four of these seven subjects had a history of hypertension for 2 yr or less. CONCLUSION: About 50% of individuals with mild-to-moderate hypertension and normal renal function may have abnormal renal transit of renal excretion agents during exercise, although their baseline studies are normal. This finding is unassociated with therapy and appears to be related directly to the pathophysiology of essential hypertension.

Adult↗
PubMed1990

Systemic to pulmonary venous shunting in superior vena cava obstruction. Unusual myocardial and thyroid visualization.

Obstruction of the superior vena cava is commonly associated with the development of several collateral venous pathways. Right-to-left systemic to pulmonary venous shunting, however, rarely has been reported. This paper describes a case in which a previously unsuspected shunt, manifested by the striking visualization of myocardial and thyroid tissue in addition to other findings, was discovered on a routine lung perfusion scan. Imaging, as well as radiologic studies are presented in the investigation of this phenomenon.

Adult↗
PubMed1990

Acute renal dysfunction during interleukin-2 treatment: suggestion of an intrinsic renal lesion.

Adoptive immunotherapy with interleukin-2 (IL-2) and lymphokine-activated killer (LAK) cells has been effective in treating some advanced malignancies in animals and humans. One complication of this treatment is a reversible, oliguric, acute renal failure, which has been ascribed to renal hypoperfusion and resultant prerenal azotemia. We serially studied renal function in 10 patients receiving high-dose regimens of recombinant interleukin-2 (rIL-2) to attempt to delineate further the nature of the renal dysfunction caused by IL-2 treatment. Renal plasma flow was computed from iodine 131 (I-131 Hippuran; Mediphysics, Paramus, NJ) orthoiodohippurate, excretion curves, and glomerular filtration rate (GFR) was determined by creatinine clearance. Studies done prior to and on day 4 of treatment showed that GFR fell in nine of 10 patients, with a mean decrease of 43% +/- 8%, and renal plasma flow fell in five of the 10 patients with a mean decrease of 5% +/- 10%. The average pretherapy filtration fraction was calculated to be 23% +/- 1% and after 4 days of treatment, decreased to a mean value of 15 +/- 2%. The BUN to creatinine ratio also declined in all patients. These findings collectively suggest that IL-2 nephrotoxicity may result from an intrarenal defect in addition to the previously described prerenal azotemia. Additionally, radionuclide studies of renal function are a reliable and reproducible noninvasive method of assessing these changes in renal function.

Acute Kidney Injury↗
PubMed1988

Mechanical responses of tendons to repeated extensions and wait periods.

Tendon specimens were repeatedly extended to peak strains of either 2, 3, 4, or 6 percent. During the three 1800 s (30 min.) periods of cyclic extension, the peak loads relaxed with decreases in hysteresis and increases in slack strain. During the two 1800 s wait periods of no extension, the specimens recovered with increases in peak load and hysteresis and decreases in slack strain. However, the recovery during the wait periods was eradicated in the first few subsequent extensions and the relaxation continued as if there were no 1800 s wait periods. Stress-strain responses were well fit with power relations.

Activity Cycles↗
PubMed1986

Positional effects on distribution of ventilation in chronic obstructive pulmonary disease.

Ventilation is distributed predominantly to the dependent lung in normal persons in the decubitus position. We evaluated the distribution of ventilation in four patients with mild-to-moderate chronic obstructive pulmonary disease using 81mKr gas. Patients were tested in the sitting and right and left decubitus positions with and without the application of positive end expiratory pressure (PEEP). In contrast to findings in controls, ventilation was predominantly distributed to the nondependent lung in patients in the decubitus position. Mean ventilation in the right lung decreased from 51% of the total in the sitting position to 31% in the right decubitus position; it increased with the application of 10 cm PEEP. Reduced ventilation in the dependent lung most likely is caused by closure of the airways after a decrease in volume. Application of PEEP resulted in increased lung volume and preferential distribution of ventilation to the dependent lung.

Aged↗
PubMed1981

Radionuclide imaging in the nonsurgical treatment of liver and spleen trauma.

Twenty-nine patients had splenic or hepatic defects on 99mTc sulfur colloid scintigraphy performed after abdominal trauma. All were treated conservatively. One additional patient had a scan after a laceration was oversewn. Followup scans in 24 patients 1 to 13 months later showed resolution that was complete in nine, partial in 12, and unchanged in three. No defects enlarged. All but two patients were completely asymptomatic; two children with occasional unexplained upper abdominal pain had progressively resolving splenic defects. We conclude that surgery may not always be necessary for liver-spleen injury, that radionuclide imaging is useful in valuation of healing as well as in initial diagnosis, and that the risk of 'delayed' rupture is much smaller than heretofore feared.

Adolescent↗
PubMed1979

Demonstration of traumatic bile leakage with cholescintigraphy and ultrasonography.

Technetium-99m HIDA cholescintigraphy and ultrasonography are noninvasive, safe, simple procedures that can document the presence, location, and extent of a bile leak. Early detection of posttraumatic or postoperative biliary tract disruption can significantly reduce morbidity and mortality. The possibility of biliary tract disruption should be considered in any patient who has had blunt or penetrating abdominal trauma. In two cases reported, the new hepatobiliary radiotracer 99mTc dimethyliminodiacetic acid (HIDA) was quite useful in detecting such leaks. Sonography was particularly useful in detecting small intra- or perihepatic bile collections which no longer communicate with the biliary tree. An active bile leak at a surgical anastomosis may also be documented by 99mTc-HIDA cholescintigraphy and can yield information of potential prognostic importance. Serial cholescintigraphy is also useful in evaluating the response to medical or surgical treatment.

Aged↗