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Biomedical subjects

S S Lee

Publications and source records attributed to S S Lee.

At least 19 recordsLinked to original sources
PubMed1992

Salivary gland neoplasms in children.

Of 29 patients, aged 3 to 16 years, with nonvasoformative salivary gland tumors, 21 had malignant tumors. Mucoepidermoid carcinoma was the most common; adenocarcinoma, adenoid cystic carcinoma, and acinic cell carcinoma were equally represented. Pleomorphic adenoma was the exclusive benign lesion, occurring in eight patients. Mean follow-up for patients with malignant lesions was 13.6 years (minimum, 3.5 years). Absolute 2- and 5-year survival rates were 100% and 90%, respectively. Mean follow-up for benign lesions was 15.9 years; none recurred. Superficial or total parotidectomy is the treatment of choice for malignant parotid neoplasms. Benign parotid lesions are adequately controlled with parotidectomy based on extent of disease. Facial nerve sacrifice can often be avoided. We advocate postoperative radiotherapy for high-grade lesions or those with adverse prognostic factors, such as soft-tissue extension and perineural invasion.

Adenocarcinoma↗
PubMed1992

Circulatory changes induced by portal venous diversion and mesenteric hypertension in rats.

We studied the hemodynamics in four groups of rats with combinations of mesenteric hypertension and portal diversion. Operations created three groups with mesenteric hypertension and different degrees of portal venous diversion: mesenteric vein stenosis, portal vein stenosis and end-to-side portacaval anastomosis with mesenteric vein stenosis, the fourth group had only portacaval anastomosis. A control group had sham operations. Cardiac output, splanchnic blood flows and portosystemic shunt indices were measured with radioactive microspheres. Mesenteric venous pressures in the mesenteric-stenosed, portal-stenosed, portacaval-shunted and end-to-side portacaval anastomosis with mesenteric vein stenosis rats were, respectively, 13.5 +/- 0.6, 15.3 +/- 0.7, 4.3 +/- 0.5 and 13.0 +/- 0.9 mm Hg, which were all significantly different from controls: 8.3 +/- 0.3 mm Hg. Portosystemic shunt indices were also significantly different from each other: controls, 0.4% +/- 0.02%; mesenteric-stenosed, 5.9% +/- 2.3%; and portal-stenosed, 52.1% +/- 4.9%. Cardiac output and splanchnic visceral blood flows were significantly increased in the portal-stenosed rats and the two groups with portacaval anastomoses, with the latter two groups having the highest values. The addition of mesenteric stenosis did not change the blood flows because mesenteric-stenosed rats did not differ from controls and end-to-side portacaval anastomosis with mesenteric vein stenosis rats did not differ from rats with portacaval anastomosis alone. These results suggest that mesenteric venous hypertension per se does not affect hemodynamics but that diversion of portal venous blood from the liver is a critical factor in the development of hyperkinetic circulation in portal hypertension.

Abdomen↗
PubMed1992

Adenosine receptor blockade reduces splanchnic hyperemia in cirrhotic rats.

To explore a possible role for adenosine in the pathogenesis of the splanchnic hyperemia of cirrhosis, we administered 8-phenyltheophylline, a specific adenosine receptor antagonist, to rats with biliary cirrhosis caused by bile duct ligation and to control sham-operated rats. Micro-Doppler flow studies showed that a 10-mumol/kg dose of 8-phenyltheophylline completely abolished the superior mesenteric hyperemic response to infusions of exogenous adenosine in both cirrhotic and control rats. Analysis of regional blood flows by radioactive microspheres demonstrated that this dose of 8-phenyltheophylline in cirrhotic rats significantly increased portal tributary vascular resistance by 60% and decreased portal tributary blood flow by 26%. This decrease was entirely the result of a 42% reduction in the intestinal blood flow. 8-phenyltheophylline did not affect cardiac output, arterial pressure or any other extrasplanchnic hemodynamic variables in cirrhotic rats. No detectable effect of 8-phenyltheophylline was seen in sham-operated rats. These results suggest that adenosine may be involved in the genesis of splanchnic hyperemia in cirrhotic rats.

Adenosine↗
PubMed1992

Characterization of spontaneous and ethanol-induced gastric damage in cirrhotic rats.

Cirrhosis was induced in Sprague-Dawley rats via ligation of the common bile duct. Changes in gastric blood flow and mucosal architecture were examined. Using an ex vivo gastric chamber preparation, the susceptibility of the cirrhotic gastric mucosa to injury by 20% ethanol was also examined. The gastric mucosa of cirrhotic animals was abnormal, even before ethanol administration. The macroscopically visible damage in these animals ranged from superficial hyperemia to epithelial sloughing. These gastric lesions were similar in appearance to the gastropathy described in cirrhotic patients, including "cherry-red spots" and areas of generalized erythema. Cirrhotic rats had a lower resting gastric transmucosal potential difference than control rats, and their gastric mucosa was also significantly more susceptible to damage by topical ethanol application. Ethanol administration caused a significant increase in gastric blood flow in control rats, whereas it significantly decreased gastric blood flow in cirrhotic rats. This lack of a reactive hyperemic response in cirrhotic rats may be responsible for the increased susceptibility of the gastric mucosa to ethanol-induced damage.

Animals↗
PubMed1992

Role of the temporal cilioretinal artery in retaining central visual field in open-angle glaucoma.

The authors reviewed the optic disc photographs of 34 eyes with high-pressure open-angle glaucoma with advanced visual field loss. Thirteen eyes (38%) had one or two temporal cilioretinal arteries, and 21 eyes (62%) had no temporal cilioretinal artery. All 13 eyes with a temporal cilioretinal artery retained central visual field and had visual acuity of 20/40 or better. In the 21 eyes without a temporal cilioretinal artery, 8 eyes lost central visual field and 12 eyes had a visual acuity of less than 20/40, while 13 eyes retained central visual field and 9 eyes had a visual acuity of 20/40 or better. Significant differences were obtained when eyes with and without cilioretinal arteries were compared for retention of visual field (P less than 0.02) and visual acuity (P less than 0.01). The presence of a temporal cilioretinal artery may provide more circulation to the temporal rim of the optic disc and aid in retaining central field and visual acuity in advanced open-angle glaucoma.

Aged↗
PubMed1992

Antilactoferrin antibody in systemic lupus erythematosus.

Lactoferrin is a secondary granule protein of neutrophils. Seventy-nine systemic lupus erythematosus patients who fulfilled the ARA criteria for classification were tested for antibody against human lactoferrin (LF-ab) by ELISA. Thirty-one of these (39.2%) demonstrated elevated levels. There was significant correlation between LF-ab positivity and disease duration. Clinical flare was common with positive LF-ab (P less than 0.05). Disease manifestations were independent of antibody status except for an increased incidence of lymphadenopathy and crescentic gomerulonephritis among those who had LF-ab. No consistent immunofluorescence pattern could be demonstrated on alcohol-fixed neutrophils for the LF-ab positive sera. It is suggested that LF-ab is related to lupus activity, and can be useful as a marker for disease monitoring.

Adolescent↗
PubMed1992

Measurement of whole blood phagocyte chemiluminescence in a microtitreplate format.

Zymosan-induced luminol-enhanced chemiluminescence of phagocytes was measured in whole blood using a microtitreplate format. A consistent reaction response curve could be obtained using a normal blood sample, with low intra-assay variations in peak light index, cumulated response as well as time taken to reach the peak. Variations were common when tests were done on different days for the same individual, or when different persons were compared simultaneously. Reactions were hastened and enhanced if continuous shaking at 37 degrees C was applied. The interval between time zero and peak was the most consistent variable, with a coefficient of variation of 12% in inter-assay analysis. Because of its simplicity and ease of operation, the method is potentially useful in studying phagocyte functions in pathological states.

Hematologic Tests↗
PubMed1992

Can we predict carbamazepine responsiveness in partial epilepsy?

We studied 153 patients with partial epilepsy who were placed on a carbamazepine monotherapy plan in order to evaluate the clinical factors that may determine drug responsiveness to carbamazepine. The subjects were divided into 3 groups based on their therapeutic outcome--complete seizure control (44%), significant seizure reduction (32%) and unsatisfactory control (24%). Fifteen tentative clinical factors were examined in relation to the therapeutic outcomes. Factors such as seizure type, number of generalized tonic-clonic seizures, age of onset, duration of illness, seizure frequency, previous treatment and EEG finding were relevant to drug responsiveness. However, other variables including mental retardation, etiology, febrile convulsion, positive family history and abnormal neurologic examination showed no significant correlation. Our data suggest that a potential success of carbamazepine treatment should not be underestimated even in patients with complicated clinical features.

Adolescent↗
PubMed1992

Prognostic value of evoked and standard electromyography in acute facial paralysis.

Ninety-one patients with idiopathic (n = 62) and traumatic (n = 29) facial paralyses were available for evaluation at least 1 year after the onset of paralysis. In nine cases of idiopathic paralysis and in 12 cases of traumatic paralysis, total intratemporal nerve decompression was performed. The remaining patients were treated with steroids alone. All patients underwent evoked electromyography (EEMG) testing within 2 weeks of the onset of paralysis. Facial nerve recovery was graded using the House-Brackmann facial nerve recovery scale. Subjects were grouped according to maximal decline of compound muscle action potential (CAP), as determined by EEMG, and by level of recovery 1 year after onset of paralysis. Among patients who did not undergo surgical decompression of the facial nerve, incomplete clinical recovery (grade III or higher) was significantly associated with CAP decline of greater than 90% (p less than 0.05) for idiopathic paralysis. In contrast, there was no significant association between CAP decline of greater than 90% and clinical outcome in traumatic paralysis. These findings support previous reports of the prognostic value of EEMG in idiopathic facial paralysis, but suggest that this test may have less predictive value in the evaluation of facial paralysis as a result of trauma.

Action Potentials↗
PubMed1992

Technetium-99m HM-PAO SPECT in patients with delayed neurologic sequelae after carbon monoxide poisoning.

We used single photon emission computed tomography (SPECT) with technetium-99m hexamethylpropylene amine oxime (99mTc-HM-PAO) in 14 studies on 6 patients with delayed neurologic sequelae from carbon monoxide (CO) poisoning to determine whether any changes in cerebral blood flow could be correlated with clinical or computed tomographic evidence of delayed deficits. Among the six initial CT brain scans, two showed low density of both basal ganglia and two showed decreased density of the cerebral white matter. There was no correlation between the clinical outcome and the findings of the follow-up CT brain scans. Of the two SPECTS with 99mTc-HM-PAO performed during acute anoxic insult, one showed focal hypoperfusion which appeared 20 days prior to the onset of delayed neurologic sequelae after CO poisoning. Seven SPECTs in the six patients performing the delayed phase showed diffuse patched patterns of hypoperfusion which improved on follow-up images. There was good correlation between the clinical outcome and the findings of the 99mTc-HM-PAO SPECT. In preliminary conclusion, 9Tc-HM-PAO brain SPECT can be used for predicting or evaluating the outcome of delayed neurologic sequelae after CO poisoning. Cerebral vascular changes may be the possible cause of hypoperfusion in patients with CO poisoning.

Adult↗
PubMed1992

Acute systemic and splanchnic haemodynamic effects of L-carnitine in patients with cirrhosis.

L-carnitine (L-C) is a naturally occurring substance in mammalian tissues that has recently been proposed as a therapeutic agent in hepatic encephalopathy and liver steatosis. L-C also produces some acute, non-metabolic, haemodynamic effects that have not previously been studied in patients with cirrhosis. Therefore, the authors evaluated the acute effect of i.v. administration of L-C (30 mg/kg) on systemic and splanchnic haemodynamics in ten patients (L-C group) with chronic liver disease (Child-Pugh's class A: 4, B: 3, C: 3 patients) and a control group composed of ten patients with similar clinical characteristics (Child-Pugh's class A: 5, B: 2, C: 3 patients) who received placebo. Heart rate, cardiac index and pulmonary arterial pressure (measured by right heart catheterization) decreased slightly but significantly in the L-C group and the changes observed in stroke volume were highly correlated to the Pugh's score. Moreover, the hepatic venous pressure gradient (measured by hepatic vein catheterization) decreased significantly in the L-C group, whereas no changes occurred in the placebo group. The overall response to L-C was contradictory to that previously observed in animals and humans with normal liver function, and the extent seemed to depend on the severity of liver disease. The effect of the drug on cardiac index, heart rate and hepatic venous gradient could possibly be beneficial for patients with hyperdynamic circulatory condition and portal hypertension.

Adult↗
PubMed1992

A two-base-pair substitution in T7 promoter by SP6 promoter-specific base pairs alone abolishes T7 promoter activity but reveals SP6 promoter activity.

The phage T7 and SP6 RNA polymerase-promoter systems are very similar in many characteristics, but maintains stringent specificity for each. In order to identify the base pair element that distinguishes between T7 and SP6 promoters, the base pairs at -12, -10, -9, and -8 of the T7 promoter consensus sequence were changed singly and multiply to the SP6 promoter-specific base pairs, and assayed for T7 and SP6 promoter activities. The results indicate that the primary discrimination element is the base pairs at -8 and -9. The two-base-pair substitution alone in T7 promoter by SP6-specific base pairs is sufficient to make the T7 variant be a SP6 promoter, abolishing T7 promoter activity.

Base Composition↗
PubMed1992

Enzymatic reduction of shogaol: a novel biotransformation pathway for the alpha,beta-unsaturated ketone system.

A novel reductive metabolism of 1-(4-hydroxy-3-methoxyphenyl)-deca-4-ene-3-one (shogaol), a pungent principle of ginger, was investigated in rat liver in vitro. Ethyl acetate-extractable metabolites of shogaol formed by incubation of this alpha,beta-unsaturated ketone with rat liver cytosolic fraction fortified with NADPH or NADPH-generating system were isolated, and two major metabolites were identified as 1-(4-hydroxy-3-methoxyphenyl)-decan-3-one (paradol) and 1-(4-hydroxy-3-methoxy)-decan-3-ol (reduced paradol). 1-(4-hydroxy-3-methoxyphenyl)-deca-1-ene-3-one (dehydroparadol), a non-pungent analog of shogaol, formed the same metabolites as did shogaol under similar incubation conditions. Paradol appears to be an intermediate in the reductive metabolism of the alpha,beta-unsaturated ketone moiety of shogaol to the corresponding saturated alcohol.

Animals↗
PubMed1991

Optic nerve head and nerve fiber layer in Alzheimer's disease.

We compared (1) the differences in the retinal nerve fiber layer between 26 patients with Alzheimer's disease and 30 age- and race-matched normal controls with use of blue-light high-resolution photography, (2) the differences in disc pallor between 30 patients with Alzheimer's disease and 32 controls with use of a boundary-tracking program and fundus photographs, and (3) the topographic disc variables between 26 patients with Alzheimer's disease and 36 controls with use of an optic nerve head analyzer. A higher proportion of patients with Alzheimer's disease had detectable nerve fiber damage as seen by red-free photography compared with controls. Although the pallor area-to-disc area ratio was not significantly different between patients with Alzheimer's disease and controls, the patients with higher pallor area-to-disc area ratios had higher Alzheimer's Disease Assessment Scale (ADAS) scores and longer durations of disease. Patients had an increased cup-to-disc ratio and cup volume and decreased disc rim area compared with controls. These variables also correlated significantly with ADAS scores and the duration of disease. The correlation among the optic nerve head changes and the ADAS scores in patients with Alzheimer's disease suggests a potential role for optic nerve head analysis in monitoring the progression of Alzheimer's disease and in assessing the effectiveness of any treatments developed.

Aged↗
PubMed1991

Prognostic variables in parotid gland cancer.

We performed a retrospective review of 178 previously untreated patients with primary malignant neoplasms of the parotid gland treated at our institution between 1960 and 1985. Patients were followed up for a median of 7.5 years. Fifty-nine percent underwent surgery alone, and 40% underwent surgery and radiation therapy. Univariate and multivariate analyses established the prognostic influence of cancer stage, cancer grade, histologic type, presence of lymphatic invasion, perineural invasion, tumor size, extension beyond the parotid gland fascia, cervical adenopathy, quality of margins, and patient age and gender. Survival was influenced most by tumor grade, tumor size, presence of positive cervical lymph nodes, and facial nerve invasion. The risk of local-regional recurrence was most affected by cervical adenopathy and tumor size. Distant metastases were predicted by tumor grade and size. At last contact, 39% of patients were alive and free of disease, while 26% had died of the disease. We analyzed the optimal surgical procedure and the rationale for the selection of combined treatment.

Adolescent↗
PubMed1991

Upper gastrointestinal bleeding following open heart surgery. Predominant finding of aggressive duodenal ulcer disease.

We reviewed our experience with endoscopically evaluated severe upper gastrointestinal hemorrhage following open heart surgery. Of 4892 patients undergoing open heart surgery, 18 (0.4%) sustained upper gastrointestinal hemorrhage requiring endoscopic evaluation. Endoscopy identified the source of bleeding in all cases. No significant complications of endoscopy were observed. Duodenal ulcers (DUs) were found in 16 (89%) of cases and were felt to be the source of bleeding in 15 (83%). Aggressive features, such as multiplicity, large size, or distal location were associated with 13 (81%) of the DU cases. Complications necessitated endoscopic or surgical therapy in eight (44%) patients with DUs. We conclude that aggressive DU disease accounts for the majority of severe upper gastrointestinal bleeding following open heart surgery.

Aged↗