Biomedical subjects

T T Tsai

Publications and source records attributed to T T Tsai.

15 recordsLinked to original sources

PubMed2000

Midbrain hemorrhage presenting with trochlear nerve palsy.

A 40-year-old normotensive man suddenly developed diplopia, tinnitus and a burning sensation on the left side of his body while driving a motorcycle. He did not complain of headache, nausea or vomiting. Neurologic examination revealed left trochlear nerve palsy and impaired pinprick, temperature and joint position sensation of the left limbs. There was no ptosis or motor deficit. He had a mild bleeding diathesis due to alcoholic liver cirrhosis. Computerized tomography and magnetic resonance image of the brain disclosed hemorrhages in the right midbrain tectum and the left temporal lobe. After nine months of observation, there was nearly complete recovery of symptoms, except for mild residual diplopia. From a literature review, only nine case of midbrain tectal hemorrhage involving the inferior colliculus have been reported. These patients had a unique clinical presentation. Diplopia due to trochlear nerve palsy, either unilateral or bilateral, was present in all of the cases. Tinnitus and sensory disturbance contralateral to the lesion side were very common. Only three patients had risk factors for hemorrhage, including bleeding diathesis, hypertension and vascular anomalies. In the majority of patients, no underlying causes were detected. The outcome was favorable with conservative treatment.

Adult↗

PubMed1999

Analysis of volition latency on antisaccadic eye movements.

The antisaccadic paradigm can be applied to test the suppression of reflexive saccades and the activation of volitional saccades simultaneously. The impaired frontal cortex has been shown to have difficulty in suppressing reflexive saccade (prosaccade) to make a successful antisaccade. Degraded antisaccade performance can also be observed in patients with Parkinson's disease (PD). The studies of PD based on the prosaccadic and antisaccadic paradigms have shown controversial findings; the latency between patients and age-matched controls could be either with or without significant difference. Even with this inconsistency, our previous study and recent analysis have supported that the latency of both prosaccade and antisaccade increases significantly for patients with PD. The objective of this study is to investigate whether prolonged antisaccade latency is caused by the affected volitional decision process (volition latency) or simply by the delayed initiation of saccade with direction opposite to the cue, by measuring prosaccade and antisaccade latency from the intermingled paradigms. Eleven mildly affected patients with idiopathic PD and eight age-matched normal subjects were tested in this study. As compared to the age-matched control, the results showed that prosaccade, antisaccadic, and volition latency of the patients was significantly elevated (P<0.01). We conclude that antisaccade performance for the PD patients was degraded for both the volition decision process and the initiation of saccade with direction opposite to the cue. Also, volition latency analysis is a more objective method than prosaccade and antisaccade latency analysis, which can be compared among results obtained from different analysis methodologies.

Aged↗

PubMed1998

Presence of serum anti-p53 antibodies is associated with pleural effusion and poor prognosis in lung cancer patients.

This study was designed prospectively to evaluate the development of anti-p53 antibodies (Abs) in lung cancer patients in relation to their clinical outcome. Sera, derived from 125 lung cancer patients, consisting of 14 small cell lung cancers (SCLC) and 111 non-SCLCs (NSCLC), were surveyed. The p53-null human NSCLC cell line, NCI-H1299, transfected with a human mutant p53 gene was prepared as the source of p53 antigen for immunoblotting analyses to detect the presence of serum anti-p53 Abs. The control group included sera from 10 healthy adults and 14 patients with benign pulmonary diseases. Clinical data including staging and survival were recorded for statistical analyses. The anti-p53 Abs were found in 8% (10 of 125) of the lung cancer patients studied (8.1% of NSCLC versus 7.1% of SCLC patients), whereas none of the control sera had detectable anti-p53 Abs. The presence of anti-p53 Abs was closely associated with malignant pleural effusions (P = 0.001). The p53 Ab-positive patients had a worse prognosis than the p53 Ab-negative patients (P < 0.02; median survival, 20 versus 41 weeks). In both univariate and multivariate analyses, the tumor extension and probably the presence of anti-p53 Abs were significant predictors for cancer death. The development of anti-p53 Abs (n = 9) was also a predictor for poor survival in patients with malignant effusions (n = 51). In conclusion, the presence of serum anti-p53 Abs is closely associated with malignant pleural effusions in lung cancer patients. It may serve as a negative prognostic factor for survival independent of malignant pleural effusions and tumor staging.

Antibodies, Neoplasm↗

PubMed1997

Superior vena cava syndrome caused by encapsulated pleural effusion.

Pleural effusion is often a manifestation of the superior vena cava (SVC) syndrome. However, pleural effusion has never been reported to be a cause of the SVC syndrome. We report the case of a 68 yr old male patient who presented with SVC syndrome and respiratory failure, both attributable to an encapsulated pleural effusion over the right upper mediastinum. Simple drainage was performed as a diagnostic and therapeutic procedure. The pleural effusion was confirmed to be a tuberculous empyema. Chest computed tomography (CT) scan is the most appropriate initial diagnostic procedure for superior vena cava syndrome.

Aged↗

PubMed1997

Foreign body aspiration into the lower airway in Chinese adults.

OBJECTIVES: Foreign body aspiration into the lower airway in adults is uncommon. We designed this study to investigate the clinical presentations, precipitating factors, management choice, and complications of foreign body aspiration in Chinese adults. PATIENTS AND METHODS: We analyzed 43 consecutive adult patients with foreign body aspiration between February 1980 and December 1995 from the medical record registry and cross index system of a tertiary medical center. RESULTS: The most common symptoms are chronic cough, hemoptsis, fever, and dyspnea. Only three patients (7%) presented with choking. Chest radiograph demonstrated the foreign body in nine cases (21%). The most common foreign body was bone fragments (21/43, 49%). Lodgment is more common in the right, especially the right intermediate bronchus and basal bronchus. Three patients were also diagnosed as having lung cancers. Precipitating factors include CNS dysfunction, facial trauma, intubation, dental procedure, and underlying pulmonary diseases. Flexible fiberoptic bronchoscopy removed the foreign body in 25 cases (58%) during the first attempt and 32 cases (74%) in total. Complications include obstructive pneumonitis (including one case of actinomycosis infection), atelectasis, bronchiectasis, lung abscess, and lung torsion (two cases). CONCLUSION: The nature of foreign body in Chinese adults was different from the Western adults. The initial clues to foreign body aspiration in adults are usually obscure or indirect. We suggest flexible fiberoptic bronchoscopy as the first-line approach. Follow-up bronchoscopy and chest radiograph are recommended to detect chronic complications or coexisting lung cancer.

Adult↗

PubMed1997

Detection of p53 nuclear protein accumulation in brushings and biopsies of Barrett's esophagus.

Alterations in the tumor suppressor gene p53 may represent a useful prognostic marker of premalignant or malignant disease in Barrett's dysplasia or esophageal adenocarcinoma. Immunohistochemistry was used to establish the ability to detect nuclear accumulation of altered p53 protein in esophageal brushings as well as biopsies, and to examine for p53 alterations in a group of 18 patients with Barrett's esophagus enrolled in a surveillance and endoscopy program, p53 protein accumulation was easily detected in esophageal brushings, and the results correlated well with matched biopsies (9/11). In patients enrolled in surveillance endoscopy, 1 brushing of 22 was positive for p53 protein accumulation. In this patient, who received preoperative radiation and chemotherapy, the positive p53 result correlated with positive cytology for residual adenocarcinoma. All Barrett's esophagus brushings negative for p53 protein were benign by cytologic, morphologic criteria. The immunohistochemical detection of p53 alterations in esophageal brushing and biopsy specimens may provide useful information in patients undergoing surveillance for esophageal dysplasia and adenocarcinoma.

Adenocarcinoma↗

PubMed1997

Sarcoidosis among Chinese in Taiwan.

Sarcoidosis is a multisystem disorder of unknown causes, characterized by widespread noncaseating epithelioid cell granuloma in more than one organ. It is rare among Chinese people. In recent years, a rapidly increasing incidence among inpatients of the Veterans General Hospital-Taipei has been noted. We retrospectively reviewed the records at our hospital from January 1960 through December 1995. We found 38 cases of sarcoidosis with biopsy-proven involvement of at least one organ system, in addition to either a typical clinical manifestation or chest radiograph. The disease-specific rate per thousand admissions increased from 0.0025 in the 1960s to 0.004 in the 1980s: for 1990 to 1995, it jumped to 0.027. Two possible explanations for the increasing incidence are greater awareness and recognition of this disease among physicians and pathologists, and advances in invasive diagnostic techniques and histopathology. Compared with patients in Western countries, sarcoidosis among Chinese patients in Taiwan had the following characteristics: 1) a higher frequency of patients (97%) had intrathoracic involvement, 2) there was a low incidence of hypercalcemia and hyperglobulinemia, and 3) there was an inclination toward older age at presentation. In conclusion, the incidence of sarcoidosis among Chinese in Taiwan has increased in the past 3 decades. The clinical presentations of patients differed from those reported from Western countries.

Adult↗

PubMed1997

Genetic polymorphism of monoamine oxidase B and susceptibility of Parkinson's disease.

BACKGROUND: Monoamine oxidase B (MAO-B) may play a role in the progression and cause of Parkinson's disease (PD), given consideration of the biochemistry and pathophysiology of the disease, and experiments on primates and humans. Assuming that the structural gene determines enzyme activity, an association study was undertaken to examine MAO-B genetic polymorphisms and look for the unique MAO-B gene alleles which occurred at a higher frequency in PD patients. METHODS: Sixty-five PD patients, diagnosed according to the criteria set by a Core Assessment Program for Intracerebral Transplantations Committee, and 108 healthy controls were enrolled in this study. Genomic DNA was extracted from peripheral leukocytes by using a puregene kit. Polymerase chain reaction (PCR) was used to amplify the MAO-B genome. The PCR products were screened by restriction enzyme Hae III digestion and analyzed by single-stranded conformational polymorphism (SSCP). RESULTS: Two bands with different mobility shifts, defined as MAO-B allele 1 and allele 2, were observed in SSCP analysis. Neither genotypes nor allelic frequencies of MAO-B showed a significant difference between PD patients and controls in our study. CONCLUSIONS: Polymorphism of MAO-B genome was demonstrated in this study. It failed to show an association of a genetic marker with PD. However, this did not necessarily exclude the MAO-B locus from playing a role in causing PD because a polymorphism different from the one evaluated here may show some disease association.

Aged↗

PubMed1995

Visual attention in Huntington's disease: the effect of cueing on saccade latencies and manual reaction times.

Studies of eye movements in patients with Huntington's disease (HD) have suggested that frontal lobe-basal ganglia structures are more involved in HD than the parietal lobes. To test this hypothesis further we compared the ability of HD patients and normal subjects to direct "covert" visual attention, using saccade latency and thumb press reaction time tasks that have been shown to be sensitive to parietal lobe dysfunction. Subjects were instructed to move their eyes or to press a button when a peripheral target was illuminated. The peripheral stimulus appeared at various intervals after the appearance of a central arrow(s) that pointed in the direction of the target (valid cue), in the opposite direction (invalid cue), or pointed simultaneously in both directions (neutral cue). For both saccade and thumb press paradigms, the difference in the latencies for trials with invalid and valid cues was the same in HD patients and normals. These findings suggest that the ability to direct visual attention is normal in HD and are compatible with the hypothesis that in HD, frontal-basal-ganglia circuits are more affected than parietal lobe pathways.

Attention↗

PubMed1994

Effects of preservation techniques on in vivo expression of adhesion molecules by aortic valve allografts.

Methods of sterilization and preservation of aortic valve allografts influence graft longevity. The effect of storage techniques on valve durability may be mediated by alterations in the immunologic properties of the allograft, which are reflected by expression of leukocyte adhesion molecules. Rat aortic valve grafts were transplanted in the fresh state, after cryopreservation (-196 degrees C), or after storage at 4 degrees C for 1 to 21 days. Syngeneic and strongly allogeneic valves were transplanted for 4 hours to 21 days and were retrieved for immunohistochemical staining for expression of leukocyte adhesion molecules. Unimplanted valves and transplanted syngeneic valves, regardless of storage methods, exhibited little or no expression of leukocyte adhesion molecules. Fresh allogeneic valves expressed all molecules, indicating up-regulation, at all time intervals studied. Cryopreserved allogeneic valves demonstrated no leukocyte adhesion molecules at 4 hours or 2 days and weak reactivity at 10 and 21 days. Allogeneic valves stored at 4 degrees C, regardless of the duration of storage, demonstrated weak expression of all molecules at 10 days and strong expression at 21 days. Expression of leukocyte adhesion molecules requires an allogeneic environment and may precede immune-mediated injury. Reduced expression of leukocyte adhesion molecules resulting from storage may predict a diminished immunologic response. Cryopreservation (-196 degrees C) causes the greatest delay and diminution of expression of leukocyte adhesion molecules.

Animals↗

PubMed1993

Endothelial cell replication in an in vivo model of aortic allografts.

Previous studies of aortic valve allograft viability have used in vitro assessments that may not reflect in vivo properties. This study evaluated in vivo endothelial cell replication in experimental valved aortic grafts and examined the consequences of histoincompatibility and cryopreservation. Valved aortic conduits were heterotopically transplanted into syngeneic or allogeneic rats. Tritiated thymidine was administered to graft recipients and control rats. After 72 hours, monolayers from the native aortas and the aortic portion of the grafts were prepared for autoradiography, with six or more silver grains per nucleus considered evidence of replication. Percentages of replicating cells in native aortas ranged from 0.3% to 2.3% (p = not significant). Percentages of replicating cells in the fresh isografts (12.4%) and allografts (12.2%) were not significantly different from each other, although each was significantly greater than the percentage in its native aorta (p < 0.04). Cryopreserved allografts and isografts displayed a few endothelial cells, none of which was replicating. Immunologic differences do not affect endothelial cell replication in this early period after fresh graft transplantation. Cryopreservation, however, results in the absence of replicating endothelium.

Animals↗

PubMed1993

Effect of cryopreservation on the presence of endothelial cells on human valve allografts.

Cryopreserved human allograft valves are useful in a variety of cardiac operations. The presence or absence of endothelial cells on allografts may be important in determining immunogenicity and ultimate graft longevity. The purpose of this study was to determine whether endothelial cells are present on cryopreserved human allografts. Portions of cryopreserved allografts (35 valve leaflets, 96 pieces of arterial wall) not used at operation were studied. For comparison, untreated tissues (44 valve leaflets, 46 pieces of arterial wall) were obtained from structurally normal hearts and lungs removed or inserted at the time of transplantation and from pathologic tissues obtained during operations for congenital heart defects. A monolayer of cells from the luminal surface of each specimen was harvested by means of a Hautchen preparation. The monolayer was stained with fluorescein isothiocyanate-labeled Ulex europaeus I, a lectin with strong affinity for human endothelium. Positive staining with fluorescein was considered to be evidence for the presence of human endothelium. Endothelial cells were observed on 21 of 131 (16%) cryopreserved allograft specimens and on 70 of 90 (78%) untreated tissues (p < 0.001). These results show that cryopreservation typically results in the loss of endothelium from aortic and pulmonary valve allografts. These findings may have important implications for the immunologic response of the host to allograft implantation.

Aortic Valve↗

PubMed1989

[Prognosis of comatose patients on ventilator: a prospective study of brain death].

The concept of brain death is widely accepted in most countries. However, there are differences in the criteria for the diagnosis of brain death. In Taiwan, the diagnostic criteria of brain death has just been established. These criteria require strict preconditions to be fulfilled, necessary exclusions to be made, and adequate time of observation to ensure the irremediability of the disease. Tests of brainstem reflexes and apnea are then performed and should be repeated at an interval of at least 4 hours to establish the diagnosis. This prospective study was undertaken in order to examine the reliability of the present criteria. A total of 79 comatose patients (57 males and 22 females) on the ventilator were collected. Their ages ranged from 2.3 to 89 years, with a mean of 46.3 +/- 20.3 years. The preconditions or exclusions were not fulfilled in 5 patients (3 with drug intoxication, 1 with septicemia, and 1 due to an unknown cause). Among them, 1 with alcohol intoxication recovered well. Of 16 patients with hypoxic/ischemic brain damage, brain death was diagnosed in only 2; in the remaining 14 patients, 6 became vegetative and 8 died from cardiac arrest. Fifty-eight patients sustained structural brain damage, and brain death was diagnosed in 50 of these patients. The most frequent cause of brain death was head injury (31 cases), followed by intracerebral hemorrhage (11 cases). Of the 52 patients fulfilling the criteria of brain death, all sustained cardiac asystole in a limited interval of time (96% in 7 days).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1986

[Clinical and immunological observations in myotonia].

Nine patients of myotonia, 5 being myotonia dystrophica and others being myotonia congenita, were studied for their clinical manifestations and immunological function. In the cases of myotonia dystrophica, they were inherited as autosomal dominant trait; the mean age onset was 17 years. Myotonia dystrophica was a diffuse systemic disorder. In addition to myotonia, there were muscle wasting, hatchet face, frontal baldness, pseudohypertrophy, etc. In the cases of myotonia congenita, none of the parents of the patients has clinical symptoms. The mean age onset was 8 years. The disease involved mainly the skeletal muscle. The immunological functions were studied in 7 patients, including 5 myotonia dystrophica and 2 myotonia congenita. In either myotonia dystrophica or myotonia congenita, the immunological functions were impaired widely, both humoral and cellular immunity. The level of serum IgG was lowered in both diseases.

Adult↗

PubMedDate not supplied

Quantification analysis for saccadic eye movements.

Traditional parameters, such as latency and peak velocity, have been used for quantitative analysis of saccade dynamics. However, saccades of equal magnitude which differ substantially in dynamics may still have the same peak velocity. This lack of selectivity might degrade the efficacy of the peak velocity measurement in discriminating patients from normal subjects. In this study, an alternative parameter, the damping ratio of a second-order response, is proposed to concisely and accurately describe saccadic dynamics. A measurement of damping ratio is made by considering the response curve of saccade as the step response of a second-order transfer function. Using the least-mean-square algorithm, the second-order function has been optimized to fit the response of the saccade dynamics with the latency removed. Nineteen normal subjects (ten young and nine older) and 16 patients of Parkinson's disease (eight mildly affected and eight advanced affected) were tested for eye movements in response to pseudorandom saccadic stimuli. While the traditional peak velocity had difficulties in differentiating between the saccadic dynamics of normal and Parkinson subjects, the damping ratio is sensitive enough not only to highlight the difference between a group of patients mildly affected with Parkinson's disease and an age-matched normal group (p<0.01; abnormal versus normal), but also to distinguish between groups at different ages (p<0.01; younger versus older). It is proposed that the damping ratio could be a useful parameter in analyzing saccadic dynamics.

Adult↗