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Biomedical subjects

D Han

Publications and source records attributed to D Han.

210 records · Page 12Linked to original sources
PubMed1987

[A case of clear cell carcinoma of the minor salivary gland].

A rare case of clear cell carcinoma of the palatal salivary gland in a 69-year-old man is reported. Histopathologically, nests and cords of tumor cells, which showed predominantly clear cytoplasms, and occasionally eosinophilic cytoplasms, proliferated on the overlying epithelium and capsules of the fibrous connective tissue. The clear cell cytoplasms were found to be PAS positive, diastase soluble, and Alcian-blue negative, indicating the presence of glycogen. Ultrastructurally, the tumor cells were found to contain glycogen and cytoplasmic filaments in various proportions. These observations suggest that clear cell carcinoma is myoepithelial in origin.

Adenocarcinoma↗
PubMed1980

Total creatinine kinase and isoenzyme MB activity in serum and skeletal muscle of a patient with dermatomyositis.

Total creatine activity was greatly increased, and creatine kinase MB isoenzyme was measurable in the serum of a patient with dermatomyositis. In contrast, total CK activity in an extract of skeletal muscle from this patient was markedly decreased as compared with normal muscle extracts, but contained about the normal proportion of the MB isoenzymes, 1.5%. We believe skeletal muscle to be the source of the MB isoenzyme in the serum, because the patient's electrocardiographic pattern was normal and she had no signs or symptoms of myocardial infarction.

Clinical Enzyme Tests↗
PubMedDate not supplied

Effects of two ACTH analogs on successive odor discrimination learning in rats.

Olfactory discrimination learning has been shown to provide a powerful tool to investigate the mechanisms involved in the formation, storage and retrieval of information in rodent CNS. In the present study we tested the effects of two ACTH analogs, which were previously reported to influence the processes of learning and memory, on various olfactory learning tasks. The ACTH(4-9) analog HOE 427 produced an apparent increase in storage of olfactory information as shown by the difficulty experienced by the animals to rapidly reverse their behavioral responses to previously learned odors. Similarly, the ACTH (4-9) analog ORG 2766 appears to enhance the storage of olfactory information when administered either before or after the learning trials. These data are consistent with the notion that ACTH and related analogs facilitate performance in a variety of learning tasks. In addition, our results suggest possible mechanisms by which some neuroactive peptides might modulate learning and memory processes in the CNS.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

Case report. Pulmonary dirofilariasis in man.

A case of pulmonary dirofilariasis in a 69-year-old woman is presented. A review of the literature revealed 56 documented cases. As in most cases of pulmonary dirofilariasis, our patient presented roentgenologically a single noncalcified coin lesion and required thoracotomy for diagnosis. The gross and histologic characteristics of the lesion, the life cycle of the parasite, the subcutaneous form of human dirofilariasis, and the possible role of the immunologic tests in establishing the diagnosis are briefly discussed. The incidence of pulmonary dirofilariasis appears to be increasing. Awareness that such entity exists is important since correct preoperative diagnosis can alleviate unnecessary surgical intervention.

Aged↗
PubMedDate not supplied

Effect of shear rates on protein adsorption in the total artificial heart.

Plasma protein adsorption is the first event in blood-material interaction and influences subsequent platelet adhesion and thrombus formation. Thromboembolic events are strongly influenced by surface characteristics of materials and fluid dynamics inside the blood pump. In vitro flow visualization, and an animal experiment with a moving actuator total artificial heart (TAH), were performed to investigate fluid dynamic effects on protein adsorption. The different levels of shear rate inside the ventricle were determined by considering the direction of opening of the four heart valves in the implanted TAH, and the visualized flow patterns as well. Each ventricle of the explanted TAH was cut into 12 segments according to the shear rate level. The adsorbed protein on each segment was quantified using an ELISA method after soaking in 2% (w/v) SDS/PBS for 2 days. Adsorbed protein layer thicknesses were measured by the immunogold method under transmission electron microscopy. Scanning electron microscopic observation showed that the right ventricle, immobilized with albumin, displayed different degrees of platelet adhesion on each segment, whereas the left ventricle, coated with polythyleneoxide-sulfonate, indicated nearly the same platelet adhesion behavior, regardless of shear rates. The surface concentrations of adsorbed proteins in the low shear rate region are higher than those in the high shear region, which was confirmed statistically.

Adsorption↗
PubMedDate not supplied

Albumin immobilized polyurethane and its blood compatibility.

Surface pretreatment with albumin on a blood contacting material inhibits platelet adhesion, activation, and subsequent thrombus formation. Although adsorbed albumin improves blood compatibility, rapid desorption occurs when this surface is exposed to circulating blood. In this study, human serum albumin was immobilized on a polyurethane (PU) surface to investigate its blood compatibility and extended effects on a blood-material interface. The PU surface was treated with hexamethylene diisocyanate (HMDI), and the PU-HMDI was further grafted with albumin to produce an albumin immobilized PU surface (PU-albumin). The PU-albumin surface was characterized by attenuated total reflection infrared electron spectroscopy for chemical analysis, scanning electron microscopy, and dynamic contact angle. Blood compatibility was evaluated by in vitro protein adsorption, platelet adhesion, and occlusion time in an ex vivo rabbit arterio-arterial shunt. Immobilization of albumin was confirmed by the disappearance of the -NCO peak observed at 2,250 cm-1 on the PU-HMDI surface by infrared spectroscopy and the existence of sulfur atomic percent by electron spectroscopy for chemical analysis. The concentration of PU-albumin was approximately 5.8 micrograms/cm2. The PU-albumin also showed a slight increase in hydrophilicity on the Wilhelmy plate method, and there was less fibrinogen adsorption than a PU control. In addition, PU-albumin had less platelet adhesion, platelet activation, and thrombogenicity. The ex vivo occlusion time of untreated PU was 50 min, that of PU-albumin was extended to 150 min, indicating that a PU-albumin surface has better blood compatibility than PU alone.

Adsorption↗
PubMedDate not supplied

Thin-section CT findings of arc-welders' pneumoconiosis.

OBJECTIVE: To describe the thin-section CT findings of arc-welders' pneumoconiosis. MATERIALS AND METHODS: Eighty-five arc-welders with a three to 30 (mean, 15)- year history of exposure underwent thin-section CT scanning. The extent of abnormalities detected was correlated with the severity of dyspnea and pulmonary function tests. For comparison, images of 43 smoking males (mean 25 pack-year) who underwent thin-section CT for other reasons (smokers' group) were also analyzed. RESULTS: Fifty-four welders (63.5%) and six smokers (14.0%) showed positive findings. Predominant thin-section CT findings were poorly-defined centrilobular micronodules (30/54, 55.6%), branching linear structure (18/54, 33.3%), and ground-glass attenuation (6/54, 11.1%). In the smokers' group, poorly-defined micronodules were found in four patients, branching linear structures in one, and ground-glass attenuation in one. In welders, the extent of abnormalities seen on thin-section CT showed no significant correlation with the severity of dyspnea or the results of pulmonary function test. CONCLUSION: Poorly-defined centrilobular micronodules and branching linear structures were the thin-section CT findings most frequently seen in patients with arc-welders' pneumoconiosis. Less commonly, extensive ground-glass attenuation was also seen.

Adult↗
PubMedDate not supplied

Budd-Chiari syndrome in women taking oral contraceptives.

The report concerns a 21-year-old woman who, after having taken oral contraceptives for three months, developed the Budd-Chiari syndrome as the results of a widespread chronic obliterative process involving the intrahepatic venous system. The diagnosis was established by liver biopsy. She was treated with supportive measures and completely recovered after 28 days of hospitalization. The literature is reviewed regarding the Budd-Chiari syndrome in women taking oral contraceptives and the clinical and pathological features seen in those reported patients are discussed.

Adult↗