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Biomedical subjects

C Lee

Publications and source records attributed to C Lee.

At least 1,135 records · Page 63Linked to original sources
PubMedDate not supplied

Inhibition of myocardial apoptosis as a therapeutic target in cardiovascular disease prevention: focus on caspase inhibition.

Apoptosis is a type of programmed cell death that is evident during embryonic development and normal tissue turnover. When the apoptotic activity extends beyond physiologic limits, it can determine and/or contribute to those pathologic states characterized by excessive cell loss and impairment of organ function. The clinical development of caspase inhibitors may represent a potential therapeutic strategy for influencing the onset and progression of ventricular dysfunction to terminal failure. This article focuses on the caspase cascade, a fundamental enzymatic system for apoptotic cell death. Caspases do not constitute the death signals, but are implicated in their transmission. These cytoplasmic cysteine proteases have a dual role in apoptosis. Caspases can operate as initiators, activating an endonuclease that catalyzes deoxyribonucleic acid fragmentation. Alternatively, caspases can act as effectors, participating in the total disassembly of cell structures. For example, apoptosis represents the principal form of myocyte death in the region of an acute myocardial infarction. In addition, apoptosis in the region bordering the infarct can influence the development of ischemic cardiomyopathy and ventricular dilation.

Apoptosis↗
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Development of canine systemic lupus erythematosus model.

The purpose of this study was to develop a model for canine systemic lupus erythematosus. Systemic lupus erythematosus (SLE) is a systemic autoimmune syndrome defined by clinical and serological features, including arthritis, glomerulonephritis, dermatitis and autoantibodies. SLE was induced in eight normal dogs by immunization with heparan sulphate, the major glycosaminoglycan of the glomerular basement membrane. All the heparan sulphate-immunized dogs showed mild-to-moderate levels of proteinuria and skin disease. Cutaneous signs associated with SLE including alopecia, erythema, crusting, scaling and seborrhoea were observed. Immunohistological examination of the skin lesions revealed deposition of immunoglobulin M and complement in the dermal-epidermal junction. Three of eight dogs showed lameness. The antinuclear antibody tests were positive with the antibody titres higher than 1:128. Therefore, this experimental SLE model could be useful for studying immune-mediated skin disease and autoimmunity.

Animals↗
PubMedDate not supplied

TPH gene may be associated with suicidal behavior, but not with schizophrenia in the Korean population.

Tryptophan hydroxylase (TPH) is a rate-limiting enzyme in the biosynthesis of serotonin. This study was designed to examine whether A218C polymorphism, which has been identified in intron 7 of the TPH gene, may be associated with schizophrenia or the suicidal behavior of schizophrenics in the Korean population. TPH genotypes were determined in DNA samples from 217 schizophrenics and 236 healthy volunteers. Among the schizophrenic group, 27 patients had a history of suicidal behavior. Genomic DNA was amplified by a polymerase-chain-reaction-based method and restricted by Nhel. A218C polymorphism was associated with a history of suicidal behavior in schizophrenics. This finding suggests that the TPH gene or a gene in its vicinity may influence suicidal behavior in schizophrenics. However, genotypic and allelic distrubutions of this polymorphism did not significantly differ between schizophrenics and controls.

Adult↗
PubMedDate not supplied

Neuromuscular block by antibiotics: polymyxin B.

Characteristics of neuromuscular block produced by polymyxin B (PXB) were examined in 12 anesthetized cats, using sciatic nervetibialis anticus muscle preparations. The ED50 was 6.7 (+/- 1.4, SD) PXB base/kg body weight. The ED95 was 10.8 (+/- 2.4) mg/kg. Spontaneous recovery from 25 percent of control to 75 percent of control required 72 (+/- 16) minutes. During a 50 percent block, train-of-four twitches elicited at 2 Hz faded with a train-of-four ratio of 0.42 (+/- 0.13), but the tetanus did not fade. Edrophonium Cl, neostigmine methylsulfate, and pyridostigmine Br at sub-clinical dosages weakly antagonized the block but enhanced the block at anti-curare dosages. All 3 cholinesterase inhibitors were short acting, lasting 10 to 15 minutes, and noncumulative on repeated injection. The potency ratio was approximately 20:10:1 in the order of edrophonium, neostigmine, and pyridostigmine on a weight-for-weight basis. Calcium partially antagonized the block. The authors conclude that neuromuscular blocks produced by various antibiotics differ from each other and from that produced by other groups of neuromuscular blocking agents, including curare.

Animals↗
PubMedDate not supplied

Cystic, peritoneal mesothelioma in a dog.

A 10-year-old, spayed female beagle was presented with a 2.5-year history of ascites. The ascitic fluid was a modified transudate with no abnormal cells present. Cardiac and hepatic functions were normal. Abdominal ultrasonography revealed cystic abnormalities of the peritoneal serosal surfaces. On exploratory laparotomy, the parietal and visceral peritonea were covered with variably sized, thin-walled cysts containing serous fluid. Histopathological, immunohistochemical, and ultrastructural analyses of the lesions were consistent with a diagnosis of cystic, peritoneal mesothelioma.

Animals↗
PubMedDate not supplied

Performance appraisal: can we 'manage' away the curse?

Call them what you will--appraisals, evaluations or reviews--performance appraisals seem to be the one organizational ritual that is universally hated. The shortcomings of this ritual, the annual documenting of bouquets and brickbats, are obvious to those who give them and those who receive them. Why do companies continue to do them? To align employee goals with those of the organization; to provide feedback on (and improve) employee performance; to identify training needs; as a basis for merit increases; to document poor performance in case it becomes necessary to defend personnel decisions in court. How can any evaluation satisfy all these objectives? One solution is performance management, a system that helps people manage their actions as a way of helping the organization achieve its goals. Ongoing effort is key to making performance management work. And it gives the employee who's off the track time to climb back on. One company put its appraisal forms online, which allows both employees and managers to update progress continuously. A goal of performance management is to enable employees to see how their objectives tie to the business objectives. Regardless of the system or methods for performance appraisal an organization uses, it will only be as good or helpful as the managers who use it.

Employee Performance Appraisal↗
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Expression of the alpha6beta4 integrin provides prognostic information in bladder cancer.

Integrins are cell surface receptors for extracellular matrix components that may participate in metastatic processes. Normal urothelial tissues show a polarized expression of alpha6beta4 integrin on basal cells at their junction with the lamina propria. We have previously shown that bladder cancers frequently overexpress one member of the integrin family, the alpha6beta4 integrin. In this study, we evaluated the level of alpha6beta4 integrin expression in bladder cancer specimens from 57 patients and correlated the expression level with patient survival. Expression was evaluated by immunoperoxidase staining. Three patterns of alpha6beta4 expression were observed: negative (13 patients); strong overexpression throughout the tumor cells (21 patients); and weak expression that most closely resembled expression in normal urothelium (23 patients). Individuals with weak staining tumors had a statistically significantly better survival (p=0.041) than patients whose tumors exhibited either no expression or strong overexpression. These data indicate that evaluation of the expression of alpha6beta4 integrin may provide valuable prognostic information on clinical outcome in patients with bladder cancer.

Antigens, Surface↗
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Overexpression of MPS antigens by squamous cell carcinomas of the head and neck: immunohistochemical and serological correlation with FDG positron emission tomography.

Survival from advanced primary or recurrent Squamous Cell Carcinoma (SCC) of the head and neck (H&N) is poor. More accurate detection of primary tumors and recurrence may provide ways to improve survival. No standard serum tumor marker is routinely used for surveillance of SCC-H&N. In this paper, we evaluated the performance characteristics of the MPS-H tumor marker test for the quantitative measurement of "MPS-H" heat-generated immunoreactive proteins and assessed the clinical utility of this marker in the detection and monitoring of SCC-H&N. In approximately 92% of the subjects having no evidence of SCC-H&N, the MPS-H levels were lower than 15 ng/mL. In 76% of patients having SCC-H&N at various stages (T1-T4), the MPS-H level was > 15 ng/mL (range: 20-200 ng/mL). In addition, we found a statistically significant correlation between PET positive cases and high MPS-H serum levels in SCC-H&N patients with recurrent disease. These results suggest that MPS-H may provide an initial screening test that would allow for selective PET imaging in these patients. Furthermore, we found that there was greater expression of MPS-1 in tumors of higher histological grades. Thus, in tumors with more histological aggressiveness there is more MPS-1, indicating the potential usefulness of this marker in prognosis for SSC-H&N. Considering the immunohistochemical, serological, and FDG-PET data presented here, and the compelling need to expedite the early diagnosis of primary and recurrent epithelial malignancies of the head and neck, we are further evaluating the system of MPS antigens in a large patient population as a tool for the early serologic and histologic diagnosis of SCC-H&N.

Adult↗
PubMedDate not supplied

Experimental cryptorchidism inhibited growth of the rat ventral prostate.

Adult Sprague-Dawley male rats, weighing about 350 g, were rendered cryptorchid by suturing the testes to the lateral abdominal wall. Twenty-eight days later, cryptorchidism resulted in a significant decline in testis weight and suppressed spermatogenesis. The ventral prostate was significantly smaller in cryptorchid rats. There was no significant difference in serum testosterone levels between the normal and cryptorchid rats. Charcoal-stripped aqueous extracts of the testis from intact and cryptorchid animals were tested on primary cultures of rat prostatic stromal cells. Cultures treated with extract from the intact testis had a significantly increased cell proliferation as assessed by cell count and by the rate of 3H-thymidine incorporation. Additionally, extracts of seminiferous tubules significantly increased prostate stromal cell proliferation compared to extracts of testicular interstitial components. Furthermore, this proliferative effect of testicular extracts is specific to the prostate as extract of both normal and cryptorchid testis stimulated proliferation of rat footsole fibroblasts in culture, but only extracts from intact testis stimulated proliferation of prostate stromal cells. These observations demonstrate that the testis produces nonandrogenic substances that can promote growth of prostatic stromal cells and that these substances were eliminated in the cryptorchid testis.

Animals↗
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3-hydroxy-3-methylglutaric aciduria presenting with Reye like syndrome: report of one case.

We report the case of a patient with 3-hydroxy-3-methylglutaric aciduria who presented with a repeat attack of Reye like syndrome clinically. Vomiting and somnolence, generalized tonic and clonic convulsions with hepatomegaly, hyperammonemia, liver function impairment, and mild metabolic acidosis were the presenting signs. 3-hydroxyisovaleric, 3-methylglutaric, 3-methylglutaconic and 3-hydroxy-3-methylglutaric acids were detected in the urine by gas chromatography-mass spectrometry. 3-methylglutarylcarnitine was also identified in the urine by fast atom bombardment and tandem mass spectrometry. Therefore, the possibility of metabolic disease should be considered in neonates and infants with repeat attacks of Reye like syndrome and a history of similarly affected siblings.

Female↗
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Cerebral infarction: assessment of patterns using ultra-fast MR contrast imaging.

We describe a rapid MR imaging technique, applying functional analysis to images obtained during the tissue transit of injected contrast material into the cerebral circulation, which has potential for assessment of the altered hemodynamics in cerebral ischemia. This technique utilized turbo-FLASH imaging maximizing the T1 relaxivity properties of gadopentetate dimeglumine with positive contrast enhancement.

Cerebral Infarction↗
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Cerebral hemodynamics and cerebral blood volume: MR assessment using gadolinium contrast agents and T1-weighted Turbo-FLASH imaging.

PURPOSE: To assess the degree and regional pattern of first-pass brain enhancement using dynamic MR imaging. MATERIALS AND METHODS: Ultrafast MR imaging (1.06-second acquisition time per image) was performed in 19 healthy subjects following a bolus IV injection of a gadolinium contrast agent; 36 patients with suspected pathology were studied using the same protocol. RESULTS: Calculated percent blood volumes were 4.9% for right cortical gray matter, 4.8% for left cortical gray matter, and 2.6% for white matter. Subtraction images were obtained that depicted the first pass "blood pool" pattern of enhancement (gray and white matter) which was significant. CONCLUSION: Preliminary evidence suggests utility for cerebral "blood pool" imaging, especially if reduced image acquisition times can be achieved.

Adult↗
PubMedDate not supplied

Unstable Jefferson variant atlas fractures: an unrecognized cervical injury.

We retrospectively reviewed the plain films and CT scans of 11 unstable atlas fractures from a series of 72 atlas fractures to better characterize these injuries and to determine if the correct diagnosis could have been made. These 11 atlas fractures were unstable because either the anterior bony ring was disrupted (six cases), the posterior longitudinal ligament was torn (one case), or both the anterior bony ring and the posterior longitudinal ligament were disrupted (four cases), allowing C1-C2 subluxation to occur. Although all the fractures were potentially unstable, only eight demonstrated subluxation on the lateral radiography. Despite the abnormal open mouth view in all cases, the plain films showed minimal abnormalities, requiring CT for definitive diagnosis. Less than half (five of 11) of the patients had other levels of spine injury or associated transverse ligament tear. Three of the 11 patients were quadriplegic, and two died as a result of their spinal cord injury. These unstable atlas fractures were similar to the classical Jefferson fracture in appearance and mechanism, except that they had fewer than four breaks in the atlas ring and were associated with severe neurologic injury and lower level spine injuries. The pattern of bilateral anterior arch fractures was associated more often with neurologic injury. Because of these differences, we chose to refer to them as Jefferson variant fractures to distinguish them from the classical Jefferson fracture and to emphasize the seriousness of this injury.

Cervical Atlas↗