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Biomedical subjects

W S Hwang

Publications and source records attributed to W S Hwang.

At least 91 records · Page 5Linked to original sources
PubMed1989

Occult prostate adenocarcinoma with pulmonary metastasis: diagnosis by fine needle aspiration biopsy of the lung and immunohistochemistry.

Metastatic pulmonary nodules were found in a 70-year-old man, who also had osteoblastic bone lesions and symptoms of prostatism. Extensive searching, including a transurethral resection of the prostate, failed to establish the primary site of the malignancy. One of the pulmonary nodules was biopsied using a fine needle aspiration technique, and revealed adenocarcinoma. The tumor cells in this lesion stained positive for prostate specific antigen. The patient was treated with estrogen for prostatic carcinoma and improved.

Adenocarcinoma↗
PubMed1989

Collagenous colitis and microscopic colitis: the watery diarrhea-colitis syndrome.

Nine patients (seven females, two males) with chronic watery diarrhea and nonspecific colonic mucosal inflammation followed for 1-5 yr are presented. Eight were diagnosed as having collagenous colitis on the basis of marked thickening of the subepithelial collagen layer in at least one set of biopsies. The thickness of the collagen table varied with time in all eight cases. When thickening was minimal, morphological features were indistinguishable from microscopic colitis, signifying that, in most cases, collagenous colitis and microscopic colitis are part of the same spectrum of colonic mucosal response. One of the eight patients had documented collagenous colitis and gluten-associated enteropathy for 12 yr. The colitis and duodenal histology improved synchronously when a gluten-free diet and corticosteroids were administered. The ninth patient had microscopic colitis and enteropathy which did not respond to gluten withdrawal. This patient never exhibited thickening of subepithelial collagen in repeated biopsies over 5 yr, suggesting that an entity of microscopic colitis may exist independent of collagenous colitis. Duodenal mucosal biopsies showed normal histology in four other patients with collagenous colitis. The histological variability of collagenization and inflammation during the course of collagenous colitis and microscopic colitis and the clinical feature of watery diarrhea suggest that these two entities be grouped together as the watery diarrhea-colitis syndrome.

Adult↗
PubMed1988

Fine-needle aspiration of an apocrine breast carcinoma with multivacuolated, lipid-rich, giant cells.

The frequency of mammary apocrine carcinoma varies considerably and reflects the definitional differences of various researchers. Lipid synthesis by malignant mammary cells is not uncommon, and occasionally it is so extensive that the designation lipid-rich carcinoma is warranted. Many subtypes of lipid-rich carcinoma are described. Although focal apocrine change is observed in one type, a tumor composed predominantly of an apocrine carcinoma with an intimate admixture of lipid-rich malignant cells is previously undescribed. The fine-needle aspiration, histologic, and ultrastructural features of such a tumor is delineated for which the descriptive title lipid-rich apocrine carcinoma is coined.

Adult↗
PubMed1988

The histopathology of the upper airway in the neonate following mechanical ventilation.

Laryngotracheobronchial lesions were carefully documented in 26 neonatal autopsies and were classified into two main types. Type I lesions were focal desquamative or ulcerative, asynchronous, and variable in severity involving areas exposed to contact with endotracheal tube or suction catheter. These lesions are most likely due to trauma of artificial ventilation. Type II lesions were diffuse, necrotizing, more synchronous and uniform in severity involving tissues distal to the endotracheal tube and extending to second or third generation bronchi. The early or mild type II lesions consisted of coagulative necrosis of epithelial cells and mucosal oedema. The late or severe type II lesions showed features similar to those of necrotizing tracheobronchitis described by Metley et al. All the cases with type II lesions had been ventilated with 100 per cent oxygen continuously for at least 3 h during life. The use of pure oxygen may be an important factor leading to necrotizing tracheobronchitis.

Bronchi↗
PubMed1988

Alteration of pulmonary structure by Pseudomonas aeruginosa exoenzyme S.

Intratracheal administration of purified Pseudomonas aeruginosa exoenzyme S elicited extensive, grossly observable damage in the rat lung within 2 h. Light and electronmicroscopy revealed injury and necrosis of bronchial epithelium, type I pneumocytes and capillary endothelial cells after 1 h; associated haemorrhage, fibrinous exudation and released type II cell lamellar bodies in alveolar lumina after 1-12 h; progressively increasing accumulations of polymorphonuclear leucocytes in the bronchi and alveoli and in alveolar septae (interstitial pneumonia) after 1-12 h; collapse of alveolar septal connective tissue and damage to pulmonary arterioles and venules. Treatment of monolayer cultures of bronchial fibroblasts with purified exoenzyme S elicited vacuolation of the cells with apparent membrane damage as revealed by light and electronmicroscopy. In-vivo production and activity of P. aeruginosa exoenzyme S may be an important pathogenicity determinant in the necrotising lung injury characteristic of P. aeruginosa pneumonia.

ADP Ribose Transferases↗
PubMed1987

Fat embolization and pulmonary infiltrates after bone marrow transplantation.

Pulmonary interstitial infiltrates developed in a 22-year-old female after bone marrow transplantation (BMT) for acute lymphoblastic leukemia (ALL) in second remission. She was receiving prednisone for graft versus host disease (GvH). There was some evidence of cardiac failure, but the primary diagnosis was that of cytomegalovirus (CMV) pneumonia, which resolved. Recurrent infiltrates were associated with the appearance of fat emboli in the pulmonary capillaries. There was little histological evidence of CMV pneumonitis, although other tests confirmed persistent infection. The patient recovered after further treatment directed at CMV infection and cardiac failure with a modest reduction in steroid dose. Most previous descriptions of pulmonary fat embolization (PFE) in immunocompromised patients have been derived from autopsy studies, and the majority of patients have received steroid therapy. The present case illustrates that PFE may complicate or contribute to the picture of interstitial pneumonitis (IPN) in the BMT recipient and that this syndrome may be reversible.

Adult↗
PubMed1987

Fibrous hamartoma of infancy.

Fibrous hamartoma of infancy is an uncommon fibroproliferative lesion that occurs only in infancy and childhood. The present case is unusual for the presence of two separate lesions, infiltration into the superficial muscle, infiltration and entrapment of nerves, and rapid recurrence after initial surgery. Despite these unusual and suspicious features, follow-up evaluations over the 15 months subsequent to the last resection showed no evidence of recurrence.

Axilla↗
PubMed1987

Invasiveness of Yersinia enterocolitica lacking the virulence plasmid: an in-vivo study.

Rabbits were given, by the intra-gastric route, two isogenic strains of Yersinia enterocolitica that differed only in the presence or absence of the virulence plasmid. Clinical illness and characteristic morphological lesions of Y. enterocolitica infection were seen only in rabbits infected with the plasmid-bearing strain (MCH700S). Although rabbits infected with a strain lacking the plasmid (MCH700L) remained healthy, mild histological changes in the small intestine, consisting of epithelial-cell damage, dilatation of lymphatics and a slight increase in neutrophil polymorphonuclear leukocytes in lamina propria, were seen in the first 12 h after inoculation. Bacteria, which were identified as Y. enterocolitica by indirect fluorescent antibody staining, were seen in dilated lymphatics. These early lesions tended to abate quickly and were no longer detectable at 24 h. Strain MCH700L was recovered from the mesenteric lymph nodes in increasing numbers until 24 h after inoculation; the number then began to decrease rapidly. In contrast, the early lesions in rabbits given strain MCH700S progressed to micro-abscesses, focal destruction of villi, and ulcerations beginning 24 h after inoculation; the number of bacteria recovered from the lymph nodes continued to increase beyond 24 h after inoculation. Bacteria were also recovered from the liver and spleen. These results suggest that both plasmid-bearing and non-bearing strains of Y. enterocolitica are capable of penetrating the intestinal mucosa. However, the virulence plasmid is required for invading bacteria to proliferate in the host tissue and to establish infection.

Animals↗
PubMed1987

Plasmid-mediated resistance to phagocytosis in Yersinia enterocolitica.

Results of our previous studies have shown that the chemiluminescence response of human neutrophils (polymorphonuclear leukocytes [PMNs]) is inhibited by plasmid-mediated cell surface components from Yersinia enterocolitica. In this study we examined the susceptibility to phagocytosis of Y. enterocolitica cells with or without plasmid-mediated surface structure and the effect of isolated outer membrane fragments on phagocytosis of Escherichia coli by PMNs in vitro. Y. enterocolitica cells with expressed plasmid-mediated surface structure were much less sensitive to ingestion by PMNs than those without it, and the resistance to phagocytosis was readily eliminated in a dose-dependent fashion by pronase treatment of whole cells, which was shown to remove plasmid-encoded outer membrane proteins. Ingestion and intracellular killing of E. coli were inhibited significantly in the presence of isolated outer membrane fragments derived from plasmid-bearing Y. enterocolitica cells. To assess the interaction of Y. enterocolitica with phagocytic cells in vivo, two isogenic strains of Y. enterocolitica, differing only in the presence or absence of the virulence plasmid, were inoculated intradermally into the backs of rabbits; and tissue sections obtained at 12 h postinoculation were examined by light and electron microscopy. The plasmidless strain was found almost entirely in PMNs or mononuclear cells. In contrast, the plasmid-bearing strain was found to be surrounded by, or interspersed with, PMNs and mononuclear cells; but most bacteria were extracellular, with little evidence of phagocytosis. These results suggest that plasmid-mediated cell surface components of Y. enterocolitica act as antiphagocytic factors, thus facilitating the survival and proliferation of the organism in the host tissue.

Animals↗
PubMed1987

Metastatic renal carcinoma to larynx.

The larynx is a most unusual site for metastatic cancer. A case of metastatic renal cell carcinoma of the larynx is presented to illustrate the following features: its exceptional indolent course; the difficulty in arriving at a correct diagnosis, and the good result following local excision.

Carcinoma, Renal Cell↗
PubMed1986

Collagenous colitis: a disease of pericryptal fibroblast sheath?

Mucosal biopsies from four women with collagenous colitis and ten controls were studied. By light microscopy the cells of the pericryptal fibroblast sheath appeared diminished in number but increased in size in collagenous colitis. Electron optically in the controls the pericryptal fibroblasts were in intimate contact with the epithelial basal lamina in the crypts. On the free surface the fibroblasts maintained contact with the epithelial cells by attenuated cell processes. In collagenous colitis, in the middle and upper thirds of the crypts the fibroblasts sheath was separated from the epithelium and the fibroblasts assumed the characteristics of myofibroblasts. The separation was accentuated towards the mouths of the crypts. Beneath the surface epithelium the attenuated fibroblast cell processes seen in normal colon were grossly deficient. The basal lamina was also deficient focally and the surface epithelial cells were resting directly on a thickened collagen table. In collagenous colitis the excess collagen appeared to be secreted by the activated myofibroblasts of the pericryptal sheath.

Adult↗
PubMed1986

A comparative study on the binding characteristics of the tight serum biliverdin-protein complexes in two fishes: Anguilla japonica and Clinocottus analis.

The binding characteristics of biliverdin to its carrier protein in the blue-green blood of Clinocottus analis (woolly sculpin) and Anguilla japonica (freshwater eel) were operationally defined by various chemical probing methods and spectra analysis. The biliverdin in C. analis is a rotatable coiled molecule enveloped in a hydrophobic pocket of its carrier protein. The biliverdin in A. japonica is an open form molecule with external hydrogen bond or weak ester bond interacting with the carrier protein. This, for the first time, shows that the novel firm binding biliprotein complexes in the blood of different species are biochemically different. Their comparative and evolutionary significance is discussed.

Anguilla↗
PubMed1985

Sacrococcygeal teratoma.

Eight cases of sacrococcygeal teratoma are described. Seven patients were diagnosed at birth, and one presented at 3 1/2 months of age with urinary retention. Two patients had associated congenital anomalies (arachnoid cyst, external angular dermoid and bifid sacrum), while one had a family history of sacrococcygeal teratoma. All had the tumour removed together with the coccyx as soon as the diagnosis was made. None had recurrence of the tumour.

Female↗
PubMed1985

Pulmonary angiomatoid vascular changes in mitomycin C-associated hemolytic-uremic syndrome.

Angiomatoid vascular changes in lungs and pulmonary hemorrhage are described in a woman in whom mitomycin C-associated hemolytic-uremiclike syndrome developed. These changes represent part of the spectrum of vascular damage that may complicate mitomycin therapy. Patients receiving mitomycin C chemotherapy require careful monitoring for possible development of these complications.

Female↗
PubMed1982

Chondro-osseous changes in Cerebro-Oculo-Facial-Skeletal (COFS) syndrome.

Radiological and pathological findings were described in three cases of COFS syndrome. Early diagnosis of this syndrome is possible by the recognition radiologically of the characteristic proximal displacement of second metatarsals and pathologically by the extensive cell necrosis in the iliac crest biopsy. Pathological findings, including the presence of nuclear bodies in chondrocytes and amianthoid fibres surrounding necrotic cartilage cells, are compatible with a primary degenerative/deformative disorder. The aetiology of this syndrome is unknown.

Abnormalities, Multiple↗