Biomedical subjects

S J Lin

Publications and source records attributed to S J Lin.

At least 73 records · Page 4Linked to original sources

PubMed1999

Differential coronary microvascular function in patients with left ventricular dysfunction of unknown cause--implication for possible mechanism of myocardial ischemia in early stage of cardiomyopathy.

To evaluate whether or not coronary microvascular dysfunction is associated with exercise-induced myocardial ischemia in left ventricular dysfunction of unknown cause, both the treadmill exercise test (TET) and coronary hemodynamics were studied in 20 patients with impaired left ventricular ejection fraction (<50% by radionuclide ventriculogram), normal cardiac size, normal coronary angiogram and no evidence of clinical heart failure. Ten subjects with atypical chest pain were studied as the control. Coronary hemodynamics were studied both at baseline and after dipyridamole infusion (0.56mg/kg, i.v. for 4'). There was no difference in age, gender, blood pressure, baseline great cardiac venous flow (GCVF) and coronary vascular resistance between ten patients with a positive TET and the other ten with a negative TET. At baseline, coronary sinus oxygen concentration was increased and myocardial oxygen consumption reduced in patients with a positive TET compared with those with negative a TET. After dipyridamole infusion, maximum GCVF (102+/-47 vs. 144+/-31 ml/min, P=0.027) and coronary flow reserve (2.31+/-0.49 vs. 3.00+/-0.61, P=0.012) were significantly reduced and minimum coronary vascular resistance was higher (1.00+/-0.42 vs. 0.63+/-0.12 mmHg/ml/min, P=0.016) in patients with a positive TET than in those with a negative TET. At follow-up, 40% of patients with a positive TET and 10% of those with a negative TET developed clinical heart failure with a dilated left ventricle during a period of 45 months. Thus, coronary microvascular function is heterogeneous in patients with left ventricular dysfunction of unknown cause. In some of them, coronary microvascular dysfunction could be related to the presence of exercise-induced myocardial ischemia, suggesting that similar pathophysiology underlies the early stage of dilated cardiomyopathy and syndrome X.

Adult↗

PubMed1999

Results of coronary stenting after delayed angioplasty of the culprit vessel in patients with recent myocardial infarction.

Little information is available concerning the effect of late coronary stenting in patients with recent myocardial infarction, especially long-term results. We retrospectively reviewed our results of 57 stent placements in 52 consecutive patients who received stents at an infarct-related lesion 24 hr to 30 days after an acute myocardial infarctions (median, 14 days). The average age was 67 years; 90% were male. Two patients who suffered from acute stent thrombosis received revascularization again and two early deaths were due to refractory cardiogenic shock before discharge. Mean patient clinical follow-up was 18.3 +/- 6.5 months. There were 1 subacute stent thrombosis, 1 cardiogenic death, and 10 patients (20.8%) in total suffering from angina class II to IV. Angiographic follow-up was performed in 36 patients (80%) at a mean of 7.5 +/- 3.1 months. Of these 36 patients, only 1 (3% of the total population undergoing follow-up angiography) had reocclusion at follow-up, but restenosis existed in 18 patients (50%). We conclude that there is still relatively high incidence of angiographic recurrence that is often silent in long-term follow-up, though the long-term result of late stenting in recent MI is low incidence of reocclusion.

Aged↗

PubMed1999

Intracellular pathways of copper trafficking in yeast and humans.

In the bakers yeast S. cerevisiae, there at least four intracellular targets requiring copper ions-1) Ccc2p and Fet3p in the secretory pathway (homologues to Menkes/Wilson proteins and ceruloplasmin); 2) cytochrome oxidase in the mitochondria; 3) copper transcription factors in the nucleus; and 4) Cu/Zn superoxide dismutase (SOD1) in the cytosol. We have discovered a small soluble copper carrier that specifically delivers copper ions to the secretory pathway. This 8.2 kDa factor known as Atx1p, exhibits striking homology to the MERp mercury carrier of bacteria and contains a single MTCXXC metal binding site also found in the Menkes/Wilson family of copper transporting ATPases. Our studies show that Atx1p is cytosolic and facilitates the delivery of copper ions from the cell surface copper transporter to Ccc2p and Fet3p in the secretory pathway; furthermore, it is not involved in the delivery of copper ions to the mitochondria, the nucleus or cytosolic SOD1, implicating specific signals directing Atx1p to the secretory pathway. Homologues to Atx1p have been found in invertebrates, plants and humans, and the human gene is abundantly expressed in all tissues. In addition to Atx1p, we have recently uncovered an additional metal trafficking protein that appears to specifically deliver copper ions to SOD1. Mutants in the corresponding gene (lys7) are defective for SOD1 activity, and are unable to incorporate copper into SOD1, while there is no obvious impairment in copper delivery to cytochrome oxidase of Fet3p. The encoded 27 kDa protein contains a single MHCXXC consensus copper binding sequence and close homologues have been identified in a wide array of eukaryotic species including humans.

Amino Acid Sequence↗

PubMed1999

PFAPA syndrome (Periodic Fever, Aphthous stomatitis, Pharyngitis, Adenitis).

This paper aims to remind paediatric clinicians to suspect and confirm 'PFAPA' syndrome (Periodic Fever, Aphthous stomatitis, Pharyngitis and cervical Adenitis syndrome). We report two cases of PFAPA syndrome: a 3-year-old healthy boy with atopic rhinitis and a boy aged 8 years 5 months who simultaneously had lymphocytic vasculitis syndrome treated with immunosuppressive drugs. Both met Marshall's criteria. The literature regarding PFAPA syndrome was complied using a Medline search for articles published between 1963 and 1998 and we then reviewed the reference lists of the articles. The Medline search revealed 28 cases with available clinical manifestations, management and prognosis. Our study describes two additional cases. We divided the cases into typical (28 cases) and atypical (two cases) PFAPA syndrome. In typical PFAPA, the age of onset was less than 5 years in most cases and the patients presented 4.9 +/- 1.4 days of fever (100%), pharyngitis (89.3%), cervical adenitis (72.1%), stomatitis (71.4%), malaise (64.3%), headache (60.7%), abdominal pain (53.6%) and nausea/vomiting (17.9%). Afebrile intervals were 3.2 +/- 2.4 months and increased with age. The time from initial onset to final episode was 3 years 7 months +/- 3 years 6 months. The total number of episodes was 8.3 +/- 2.5 (range 6-14). Effective treatment included steroids, tonsillectomy/adenoidectomy and cimetidine. The general outcome was good. In atypical PFAPF, the clinical manifestations were similar to those of typical PFAPA except that the age of onset was more than 5 years, and life-threatening intestinal perforation happened once in a patient with underlying Fanconi's anaemia. It was concluded that typical PFAPA syndrome is benign and can be diagnosed by detailed history-taking and from physical findings during repeated febrile episodes with tests to rule out other periodic fever syndromes. A review of the literatures since the first report in 1987 has shown that typical PFAPA syndrome is not associated with significant long-term sequelae and has a good response to steroids. One patient with atypical PFAPA, who received low-dose steroids for over 1 year, developed intestinal perforation after an increment of the 7-day steroid dose. If an underlying problem requires long-term immunosuppressive medication, it is wiser to choose cimetidine rather than increasing the steroid dosage to resolve atypical PFAPA.

Azathioprine↗

PubMed1999

Thrombocytopenia in systemic-onset juvenile chronic arthritis: report of two cases with unusual bone marrow features.

Two children with systemic-onset juvenile chronic arthritis (S-JCA) suffering from severe, symptomatic thrombocytopenia are reported. Case 1 is a 10-year-old girl who had fever, chronic polyarthritis and hepatosplenomegaly for 6 months and severe gum bleeding and generalised petechiae for 1 week. Immune thrombocytopenic purpura (ITP) was indicated by bone marrow findings of megakaryocytic hyperplasia, and her thrombocytopenia responded well to steroid therapy without recurrence, but progressive, deforming polyarthritis with anaemia and thrombocytosis persisted. Case 2 is a 7-year-old girl who presented with spiking fever, arthritis and skin rashes and was suspected of having S-JCA. She developed a severe nosebleed with impending shock while receiving full-dose aspirin. Pancytopenia and elevated liver enzymes were also noted. Bone marrow aspiration revealed erythroid hyperplasia, maturation arrest of myeloid series with increased blasts, and adequate megakaryocytes. Her thrombocytopenia resolved in 1 week without specific treatment. Her subsequent clinical course confirmed the diagnosis of S-JCA, while thrombocytopenia did not recur during follow-up.

Arthritis, Juvenile↗

PubMed1999

Localised hyaline vascular type of Castleman's disease mimicking adult-onset Still's disease.

A previously healthy 18-year-old boy presented with daily spiking fever, polyarthritis, and evanescent skin rashes, as well as hepatomegaly and Raynaud's phenomena for 2 months. He was initially diagnosed with adult-onset Still's disease (AOSD). During the period of follow-up, intermittent fever and migratory polyarthritis persisted and an insidiously growing mass over the right axillary region was noted 1 year after the diagnosis of AOSD. Excisional biopsy of the mass revealed a group of lymph nodes with histological features of the hyaline vascular type of Castleman's disease. The patient's symptoms disappeared soon after excision of the lymph nodes. evanescent rash, lymphadenopathy, hepatosplenomegaly and serositis [5]. A clinical picture compatible with the diagnosis of AOSD has not been described in the localised hyaline vascular type of Castleman's disease. We report such a case in an 18-year-old male patient who presented prolonged fever and polyarthritis with an initial diagnosis of AOSD. The diagnosis of hyaline vascular type of Castleman's disease was made 1 year later, when the patient developed an insidiously growing mass over the right axilla.

Adolescent↗

PubMed1999

Elimination of replication block protein Fob1 extends the life span of yeast mother cells.

A cause of aging in yeast is the accumulation of circular species of ribosomal DNA (rDNA) arising from the 100-200 tandemly repeated copies in the genome. We show here that mutation of the FOB1 gene slows the generation of these circles and thus extends life span. Fob1p is known to create a unidirectional block to replication forks in the rDNA. We show that Fob1p is a nucleolar protein, suggesting a direct involvement in the replication fork block. We propose that this block can trigger aging by causing chromosomal breaks, the repair of which results in the generation of rDNA circles. These findings may provide a novel link between metabolic rate and aging in yeast and, perhaps, higher organisms.

DNA Repair↗

PubMed1999

Clinical spectrum of enterovirus 71 infection in children in southern Taiwan, with an emphasis on neurological complications.

An outbreak of enterovirus 71 (EV71) infection occurred in Taiwan in 1998. The clinical spectrums and laboratory findings for 97 patients with virus culture-proven EV71 infections were analyzed. Eighty-seven percent of the patients were younger than age 5 years. Hand-foot-and-mouth syndrome occurred in 79% of the children and central nervous system (CNS) involvement in 35%, including nine fatal cases. The predominant neurological presentations were myoclonus (68%), vomiting (53%), and ataxia (35%). Brain stem encephalitis was the cardinal feature of EV71 CNS involvement during this outbreak. Magnetic resonance imaging and pathological findings illustrated that the midbrain, pons, and medulla were the target areas. EV71 brain stem encephalitis can present either with cerebellar signs and an initially mild, reversible course or with overwhelming neurogenic shock and neurogenic pulmonary edema (NPE) resulting in a fatal outcome. Brain stem encephalitis that progressed abruptly to neurogenic shock and NPE was indicative of poor prognosis in this epidemic. Early aggressive treatment and close monitoring of the neurological signs are mandatory to improve the chance of survival.

Adolescent↗

PubMed1999

Similarity as a risk factor in drug-name confusion errors: the look-alike (orthographic) and sound-alike (phonetic) model.

BACKGROUND: One of every four medication errors reported in the United States is a name-confusion error. The rate of name-confusion errors might be reduced if new and confusing names were not allowed on the market and if safeguards could be put in place to avoid confusion between existing names. OBJECTIVES: To evaluate several prognostic tests of drug-name confusion, alone and in combination, with respect to their sensitivity, specificity, and overall accuracy. RESEARCH DESIGN: Case-control study. Twenty-two different computerized measures of orthographic similarity, orthographic distance, and phonetic similarity were used to compute similarity/distance scores for n = 1,127 cases (ie, pairs of names that appeared in published error reports or national error databases) and n = 1,127 controls. MAIN OUTCOME MEASURES: Mean similarity/distance scores were compared across cases and controls. The performance of each measure at distinguishing between cases and controls was evaluated by tenfold crossvalidation. Dose-response relationships were examined. Univariate and multivariate logistic regression models were formed and evaluated by 10 fold crossvalidation. RESULTS: Cases had significantly higher similarity scores than controls. Every measure of similarity proved to be a significant risk factor for error. There was a significant increasing trend in the odds-ratio as a function of similarity. A three-predictor logistic regression model had crossvalidated sensitivity of 93.7%, specificity of 95.9% and accuracy of 94.8%. CONCLUSIONS: A sensitive and specific test of drug-name confusion potential can be formed using objective measures of orthographic similarity, orthographic distance, and phonetic distance.

Analysis of Variance↗

PubMed1999

Insulin-like growth factor I improves cardiovascular function and suppresses apoptosis of cardiomyocytes in dilated cardiomyopathy.

To investigate how insulin-like growth factor I (IGF-I) modulates cardiovascular function and myocardial apoptosis in heart failure, the therapeutic effects of IGF-I were determined in a canine model of dilated cardiomyopathy. The animals were paced at 220 beats/min, and the left ventricular (LV) chamber became dilated after 2 weeks. A subset of paced dogs was treated with s.c. injections of IGF-I from week 3 to week 4. After 4 weeks of pacing, untreated paced dogs developed significant ventricular dysfunction. IGF-I-treated paced dogs showed better cardiac output, stroke volume, LV end-systolic pressure, and LV end-diastolic pressure. Moreover, pulmonary wedge pressure and systemic vascular resistance were increased in the untreated group and decreased in the IGF-I-treated group. IGF-I treatment was associated with less thinning of the ventricular wall. Compared with the controls, untreated paced dogs showed increased apoptosis of cardiac muscle cells, which was partially suppressed by IGF-I treatment. The myocardial apoptotic index was negatively related to the thickness of the ventricular wall and to cardiac output, suggesting that ventricular remodeling/dysfunction involves the occurrence of myocardial apoptosis. Due to the close resemblance between this experimental model of dilated cardiomyopathy and human heart failure, the results of this study provide evidence that IGF-I may be a potential therapeutic agent for the failing human heart.

Animals↗

PubMed1999

Changes of the insulin-like growth factor I system during acute myocardial infarction: implications on left ventricular remodeling.

In vitro and in vivo experiments have shown important biological actions of insulin-like growth factor I (IGF-I) in heart. The aims of this study were to determine the changes in circulating IGF-I and IGF-binding proteins (IGFBPs) during acute myocardial infarction (AMI) and to explore the relationship between IGF-I levels and myocardial remodeling and function after AMI. Thirty-four patients with acute Q-wave AMI and 17 matched controls were investigated in this study. Compared to normal subjects, free IGF-I and IGFBP-3 were significantly elevated, and IGFBP-1 was decreased upon AMI. Myocardial remodeling occurred after AMI in these patients. The day 2, 3, and 7 total IGF-I levels were inversely related to day 7 left ventricular (LV) end-diastolic, end-systolic diameters (r = -0.395 to -0.516) and LV mass (r = -0.487 to -0.661). Moreover, total IGF-I levels were positively related to LV ejection fraction (r = 0.402-0.453). Compared to the healthy survivors, those patients with poor outcomes had lower total IGF-I levels immediately after AMI. Most healthy survivors had total IGF-I levels greater than 137 ng/mL, but all patients with poor outcome had total IGF-I levels less than 137 ng/mL. Thus, AMI is associated with significant alterations in the IGF-I system. A higher total IGF-I level immediately after the onset of AMI is associated with better myocardial remodeling and ventricular function.

Echocardiography, Doppler↗

PubMed1999

Coronary flow reserve and ischemic-like electrocardiogram in patients with symptomatic mitral valve prolapse.

The purpose of the present study was to determine whether coronary microvascular function is impaired in patients with symptomatic mitral valve prolapse (MVP) and whether ischemia-like ECG, if present, is related to coronary microvascular dysfunction. Twenty chest pain patients with normal coronary angiograms and MVP proven by echocardiogram were included. Both treadmill exercise test (TET) and coronary hemodynamic study were done in each patient. Coronary flow reserve (CFR) was determined by measuring coronary sinus flow (CSF) or great cardiac venous flow (GCVF) both at baseline and after dipyridamole 0.56 mg/kg IV for 4 minutes (maximum). All patients were divided into 2 groups with either negative (TET-) or positive results of TET (TET+). Another 10 subjects with atypical chest pain, normal coronary angiograms, echocardiogram and TET were used as controls. There were no differences in GCVF, either at baseline or after dipyridamole infusion, among the 3 groups. Calculated CFR using GCVF was similar among the 3 groups. However, baseline CSF was higher in the TET+ group (TET- vs TET+ vs control: 77 +/- 24 vs 96 +/- 31 vs 75 +/- 12 ml/min, p < 0.05) and maximum CSF was lower in the TET- group (TET- vs TET+ vs control: 167 +/- 25 vs 219 +/- 85 vs 238 +/- 80 ml/min, p < 0.05). Calculated CFR using CSF was significantly reduced in both the TET- (2.26 +/- 0.4) and TET+ groups (2.31 +/- 0.7) as compared with the control subjects (3.18 +/- 0.95, p < 0.01). There were no differences in any of the hemodynamic parameters between the TET- and TET+ groups. Coronary microvascular function could be impaired in patients with symptomatic MVP. Such impairment, when presented, was probably regional and outside the territory of the left anterior descending coronary artery. However, it was irrelevant to the presence of ischemic-like ECG during exercise.

Adult↗

PubMed1999

Color Doppler ultrasonographic evaluation of osteomyelitis in children.

We investigated the capability of color Doppler sonography in evaluating acute osteomyelitis in children. Twelve children suspected of having osteomyelitis were evaluated with color Doppler ultrasonography at admission and at regular intervals to observe the inflammatory process of osteomyelitis, determine the response of antibiotic therapy, and predict the need of surgery in these patients. At admission, color Doppler flow within or around the infected periosteum was found in patients with symptoms for 4 days or longer, whereas those with symptoms for less than 4 days showed no color Doppler flow within and around the periosteum. During sonographic follow-up, six cases were found to have increased color Doppler vascular flow within and around the affected periosteum, and two of them had periosteal abscess. They eventually required surgical treatment. Persistent or increased color Doppler flow during follow-up examination correlated with elevated serum levels of C-reactive protein as well. Our study indicated that color Doppler vascular flow within or around the infected periosteum correlated with advanced acute osteomyelitis, and surgery usually was required in these patients. Those with early stage acute osteomyelitis usually showed no vascular flow within or around the infected periosteum. Thus, color Doppler sonography allowed detection of advanced osteomyelitis and revealed the progression of inflammation during antibiotic therapy. Color Doppler ultrasonography might be valuable in determining the efficacy of antibiotic therapy and justifying the need for operation.

Acute Disease↗

PubMed1999

Ultrasonographic diagnosis and color flow Doppler sonography of internal jugular venous ectasia in children.

We investigated the diagnostic utility of ultrasonography in the diagnosis of internal jugular venous ectasia. Eight children (six boys, two girls) were recruited into this prospective study. Sonography of internal jugular venous ectasia in these patients revealed fusiform dilation of the internal jugular vein, and the possibility of thrombus and external compression could be ruled out. Marked variation in size of ectatic jugular veins during respiration was demonstrated under real-time sonography. The mean anteroposterior diameter of these dilated internal jugular veins was 0.79+/-0.18 mm (mean+/-standard deviation), which increased to 1.58+/-0.27 mm with Valsalva maneuver. Our study showed that the anteroposterior diameters of the internal jugular veins in cases of ectasia were greater than those of contralateral jugular veins in same patients as well as those in normal children, and they showed greater increase after Valsalva maneuver. Under color Doppler flow studies, turbulent vascular flows were demonstrated in these patients with jugular venous ectasia. No progression of venous ectasia was found in any of our patients during a 6 month follow-up period. We conclude that internal jugular venous ectasia in children is a benign condition, which usually does not require surgical intervention. Ultrasonography is a good diagnostic modality for the diagnosis of internal jugular venous ectasia. Color Doppler ultrasonography demonstrate the turbulent flow in jugular venous ectasia.

Blood Flow Velocity↗

PubMed1999

Acute goby poisoning in southern Taiwan.

Food poisoning due to ingestion of two fishes, Yongeichthys nebulosus and Sillago japonica, occurred in Kaohsiung, Taiwan, in February 1997. Two male persons (48 and 58 years old) were poisoned, with symptoms featured by dizziness, nausea, vomiting, numbness, and difficulty in respiration. All of the specimens of fish retained by the victims were combined and consisted of Yongeichthys nebulosus and Sillago japonica. These retained specimens were assayed for anatomical distribution of toxicity (as tetrodotoxin) and all specimens were found to be toxic. The highest toxicity of specimen was 7,650 mouse units (MU) in Y. nebulosus and 1,460 MU in S. japonica. However, the other specimens re-collected from that fish pier were also found to be highly toxic in Y. nebulosus, but nontoxic in S. japonica. Hence, Y. nebulosus was judged as the real causative fish in this food poisoning. The toxins were partially purified from the methanolic extracts of toxic fishes by ultrafiltration and Bio-Gel P-2 column chromatography. Cellulose acetate membrane electrophoresis and high performance liquid chromatography analyses demonstrated that tetrodotoxin was the causative agent of this food poisoning.

Animals↗

PubMed1999

Primary sclerosing cholangitis in a child.

Primary sclerosing cholangitis (PSC) is a rare disease in Taiwan and has not been described in Taiwanese children previously. We report a 4-year-old girl who presented with prolonged fever, eosinophilia (11%), hepatomegaly, and markedly elevated serum levels of alkaline phosphatase (3,318 IU/L) and gamma-glutamyl transpeptidase (475 IU/L). Subsequent investigations including endoscopic retrograde cholangiopancreatography and liver histology confirmed the diagnosis fo PSC. Treatment with a low dose of prednisolone for 2 months and ursodeoxycholic acid during 32 months of follow-up resulted in clinical remission and halted disease progression. A high index of suspicion is necessary for physicians to diagnose this disorder in children with chronic liver disease. Our experience in this case indicates that therapy with prednisolone and ursodeoxycholic acid may be helpful for the treatment of PSC in children, and suggests the need for more trials of combined therapy.

Age of Onset↗

PubMed1999

Colour Doppler ultrasonography of retropharyngeal abscess.

OBJECTIVE: This study was conducted to determine the capability of colour Doppler ultrasonography (CDU) in evaluating retropharyngeal abscess in children. MATERIALS AND METHODS: From July 1996 to February 1998, five children with clinical suspicion of retropharyngeal abscess were evaluated by CDU. The distance from internal carotid artery (ICA) to cervical vertebra (CV) (DICA-CV) at the upper cervical level was measured by longitudinal ultrasonography. Fifty healthy children, aged from 1 to 15 years, were recruited in the study to measure DICA-CV as control. Colour Doppler ultrasonography was used to differentiate abscess from other pathology and to detect carotid sheath invasion. Computed tomography was performed to confirm the sonographic diagnosis. Measurements of the DICA-CV at regular intervals were performed to monitor the progression of retropharyngeal abscess. RESULTS: Retropharyngeal abscess was highly suspected in all cases under sonographic studies. A patient was found to have carotid sheath invasion. Computed tomography confirmed the diagnosis of retropharyngeal abscess in all cases. Retropharyngeal abscess can be evaluated by the measured DICA-CV. The DICA-CV decreased as the retropharyngeal abscess gradually resolved. CONCLUSION: Colour Doppler ultrasonography offers a sensitive method to evaluate retropharyngeal abscess in children. It can also be used to monitor the progression of retropharyngeal abscess and avoid unnecessary radiologic examinations.

Adolescent↗

PubMed1999

Development of a coronary artery aneurysm three months after stent implantation: a case report.

Coronary artery stents have been used widely to prevent acute closure as a bailout procedure, or to decrease restenosis after balloon angioplasty. Stent use has increased substantially in recent years due to the ease and simplicity with which stents provide a predictable angiographic result. However, few data exist on the long-term safety of stents. This case report describes a 63-year-old male patient who developed intimal dissection after balloon angioplasty and who underwent coronary stent placement of a sheathed stent (half Palmaz-Schatz stent, 3.5 mm in diameter and 7 mm in length) as a bailout procedure. Postdilatation with a 3.5-mm balloon was performed at the maximum pressure of 14 atmospheres with a satisfactory angiographic result. However, an aneurysmal dilatation at the stent site was noted three months later. High-pressure stent use without immediately visible vascular dissection by angiography may not be effective for prevention of coronary aneurysm development in a case such as this. Aneurysmal dilatation may be a late complication in cases of coronary artery stent placement.

Angioplasty↗