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Biomedical subjects

C Y Li

Publications and source records attributed to C Y Li.

At least 361 records · Page 20Linked to original sources
PubMed1985

Primary pulmonary lymphoma. A clinical and immunohistochemical study of six cases.

Six patients with lymphomatous lesions primarily involving the pulmonary parenchyma were studied. In these patients, both the history and physical findings were vague and minimal. The laboratory findings also were nonspecific, although the findings of large multiple lesions in the lungs and pleural adhesion or effusion were more consistent with lymphoma. Histologic examination revealed lymphocytic infiltration of the pulmonary parenchyma in all six patients and presence of germinal or growth centers in some areas of the lesions in four. The hilar or mediastinal lymph nodes were not involved in five patients so examined. Immunocytochemical study of cytoplasmic immunoglobulin revealed monoclonal lymphocytic proliferation in five patients and negative staining in one patient. Clinical, histologic, or immunohistochemical studies alone may not be sufficient to detect all of the lymphomatous lesions. The combined use of all of these parameters is more advantageous for accurate diagnosis of these lesions. Treatment is surgical resection. Radiotherapy or chemotherapy are used when residual disease is present after surgery. Three patients died of disseminated lymphoma 96, 42, and 8 months after diagnosis, respectively, and three patients are still alive at 18, 24, and 4 months, respectively.

Aged↗
PubMed1985

Immunoelectron microscopic demonstration of prostatic acid phosphatase in human hyperplastic prostate.

Immunoelectron microscopic studies were done on prostatic tissues obtained from patients with benign hyperplasia. Rabbit IgG-peroxidase conjugate against purified human prostatic acid phosphatase band 2 (HPAP-2) was used for studies. Under the light microscope, the columnar secretory epithelia of prostatic glands showed different intensity and distribution of immunostaining whereas the basal cells were unstained. Under the electron microscope, the secretory epithelial cells often showed electron-dense reaction product in the Golgi apparatus and secretory vesicles and vacuoles, and only sparingly in the cisternae of nuclear envelope and rough ER. Sometimes, fusion of secretory vacuolar membrane and plasma membrane and discharge of the vacuolar contents into the extracellular space were noted. The surfaces of microvilli at the apical portion of the columnar epithelia and the lumen of the glandular acini always showed reaction product. These findings suggest that HPAP-2 may be synthesized in the rough ER and transported to the Golgi apparatus where it is concentrated and transferred to the secretory vesicles and vacuoles. HPAP-2 is finally discharged into the extracellular spaces through exocytosis, a secretory mechanism similar to that of other secretory proteins.

Acid Phosphatase↗
PubMed1985

Infectious mononucleosis mimicking a B cell immunoblastic lymphoma associated with an abnormality in regulatory T cells.

An elderly woman is described with infectious mononucleosis in whom cervical node biopsy was interpreted as showing immunoblastic lymphoma. Concomitant reactive lymphocytosis, Epstein-Barr virus serologic results consistent with an acute infection, and demonstration of polyclonal B cell infiltration of other tissues argued against intervention. Defective in vitro T cell responses were demonstrated during the acute phase of Epstein-Barr virus infection. Infectious mononucleosis has rarely been reported as mimicking a non-Hodgkin's lymphoma. At 18 months, our patient's course has been typical for infectious mononucleosis with no evidence of disseminated malignancy.

Aged↗
PubMed1985

Texture discrimination: representation of orientation and luminance differences in cells of the cat striate cortex.

Neuronal texture discrimination in the cat striate cortex was investigated by measuring the responses of single cells to different pattern structures. The representation of two independent features, texture orientation and texture luminance, was analysed in detail and the sensitivity of neurones to either feature was studied at different levels of structure density. Texture patterns were systematically moved across the receptive field. From the cell response to various parts of the pattern, "response patterns" were generated which displayed the cell transform of the textured stimulus pattern. Only when texture structures were coarse, were cells able to encode the texture orientation of an area. Differences in texture luminance, on the other hand, were detected only in fine texture structures. Further, these textural features were processed in a different manner: Cells responded to differences in texture luminance but continuously to areas of similar texture orientation. Thus, responses of striate cells reveal an ambiguous representation of texture features and a failure to uniquely encode texture borders.

Animals↗
PubMed1985

Immunoalkaline phosphatase cytochemistry. Technical considerations of endogenous phosphatase activity.

The authors have developed an immunoalkaline phosphatase method and have applied it with success to the study of blood cells. They have now observed that macrophages in tissues and in serous effusions may be nonspecifically stained when immunoalkaline phosphatase methods are used. A systematic study of this endogenous macrophage phosphatase activity has shown it to have a pH optimum of 5.0-6.0 (acid phosphatase), but it remains weakly active in the mildly alkaline conditions used in the immunoalkaline phosphatase procedure. At its pH optimum, this macrophage phosphatase is mostly tartrate resistant, however, when 50 mM tartrate is added to a staining medium of pH 7.6-8.0, the residual endogenous phosphatase activity effectively is inhibited. When immunochemical studies are conducted by immunoalkaline phosphatase methods, the authors recommend addition of 50 mM tartrate to a buffer of pH 7.6-8.0. This modification does not significantly decrease the sensitivity of the specific staining of surface antigens.

Alkaline Phosphatase↗
PubMed1985

Adult-onset urticaria pigmentosa and systemic mast cell disease.

The records of 32 patients with adult-onset urticaria pigmentosa were analyzed to determine if any clinical or pathologic findings could distinguish urticaria pigmentosa associated with systemic mast cell disease from urticaria pigmentosa with no clinical evidence of systemic mast cell disease. Thirteen patients had biopsy-proven systemic mast cell disease, and 19 had no documentation of systemic mast cell disease after at least 20 years of follow-up. Generally, urticaria pigmentosa with systemic mast cell disease could not be differentiated from urticaria pigmentosa with skin involvement only. Although most patients in both groups had mast cells in a perivascular location, four patients had dense infiltrates filling the papillary dermis. Two of these patients had biopsy-proven systemic mast cell disease, and two had clinical symptoms that could have been produced by systemic mast cell disease, although the diagnosis was not proved by biopsy. The presence of dense infiltration by mast cells in urticaria pigmentosa with cytologic atypia may correlate with the presence of systemic mast cell disease.

Adult↗
PubMed1985

Leukemia cutis. A histopathologic study of 42 cases.

Biopsy specimens of skin from 42 patients with leukemia cutis were studied. Typing of leukemia was based on histopathologic and histochemical findings in peripheral blood and bone marrow. There were three patients with acute lymphocytic leukemia, 16 with chronic lymphocytic leukemia, 12 with acute granulocytic leukemia, three with chronic granulocytic leukemia, five with acute monocytic leukemia, and three with acute myelomonocytic leukemia. In general, leukemia cutis shows a diffuse infiltration of leukemic cells in the dermis and subcutaneous tissue, often infiltrating between collagen bundles. Extensive involvement and disruption of blood vessels and skin adnexa are characteristic findings in granulocytic, monocytic, and myelomonocytic leukemia cutis, but biopsy specimens of skin in patients with different types of leukemia show a wide range of histopathologic changes that are variable among the various types of leukemia and sometimes even among different patients with the same type of leukemia. A final typing of leukemia should not rely only on regular histopathologic findings of a skin biopsy, but should depend more on morphologic and histochemical studies of smears of peripheral blood or of bone marrow or both.

Humans↗
PubMed1985

T-cell chronic lymphocytic leukaemia: anomalous cell markers, variable morphology, and marked responsiveness to pentostatin (2'-deoxycoformycin).

4 men with an unusual variant of T-cell chronic lymphocytic leukaemia are reported. The clinical features differed from the virus-associated T-cell disease reported from Japan, the Caribbean, and the southeastern United States. Cytology was pleiomorphic: cells with cerebriform nuclei resembling Sézary cells and lymphocytes with cytoplasmic granules resembling T-suppressor cells occurred in the same patients. Immunofluorescence studies with monoclonal antibodies suggested that the leukaemia cells expressed determinants of both helper- (OKT4+) and suppressor-(OKT8+) related antigens. The cells were TdT-negative. In all patients the disease was very refractory to conventional cytotoxic agents, but there was prompt and extensive response to the adenosine deaminase inhibitor pentostatin (2'-deoxycoformycin). This agent merits further study in the treatment of T-cell chronic lymphocytic leukaemia.

Adult↗
PubMed1985

Immunohistochemical detection of monocytes by the antiserum specific to monocytic esterase.

An antiserum specific to esterase Ib was produced in a rabbit. The antigen-antibody reaction was visualized by the strong esterase activity in the precipitin band in Ouchterlony double diffusion and immunoelectrophoresis. Immunohistochemical procedure demonstrated strong staining in the monocyte-infiltrated splenic sections and tissue sections of true histiocytic lymphoma. Negative results were observed in T- and B-cell lymphomas, granulocytic sarcoma, and chronic granulocytic leukemia. This antibody may be useful for the identification of monocytes and histocytes in paraffin-embedded tissue sections.

Animals↗
PubMed1985

Simultaneous demonstration of nonspecific esterase and chloroacetate esterase in human blood cells.

A new cytochemical method is described for the simultaneous demonstration of nonspecific esterase in monocytes and chloracetate esterase in granulocytes. The procedure uses both alpha-naphthyl butyrate and naphthol AS-D chloroacetate as substrates and hexazotized pararosaniline as the coupler. The enzyme reaction products are highly chromogenic and their localization is precise. This method is potentially useful for the accurate diagnosis of the acute monocytic leukemias. Its advantages and limitations are also discussed.

Acute Disease↗
PubMed1984

Representation of spatial details in textured patterns by cells of the cat striate cortex.

The ability of single cells to represent the spatial details of textured stimuli was investigated. Two complementary aspects of cell response were considered, the ability to discriminate fine stimulus details and the property of integration over wider areas of a structure to encode differences in mean luminance. Responses of simple and complex cells were distinct in some respects. Spatial discrimination: Simple cells would encode orientation of line arrays as long as individual line elements could be spatially resolved. By contrast, complex cells were able to distinguish the orientation of texture areas even when the individual lines of the stimulus were not resolved in their response. Threshold sensitivity for texture orientation was of the same order in both cell classes despite differences in receptive field size. Spatial integration: Complex cells responded to texture luminance differences of much coarser patterns than did simple cells. These responses, however, were not biased for contour orientation unless finer patterns were used. Only with very fine textures did responses become indistinguishable from those to uniform stimuli for both simple and complex cells. For complex cells, there was a smooth transition from resolution to fusion of spatial details with increasing structural density. Simple cells were insensitive to both detailed and global properties of a stimulus pattern over a wide range of texture density. Implications for alternative measures of visual acuity of single cells are discussed.

Animals↗
PubMed1984

The representation of contrast and other stimulus parameters by single neurons in area 17 of the cat.

The responses of neurons in area 17 were tested as a function of various stimulus parameters. The thresholds of individual cortical neurons were at contrasts between 0.01 and 0.1 (increment of 0.5 X 10(-1) cd/m-2 on a background of 3 cd/m-2), the dynamic ranges were 1.0-2.0 log units of increment, and all cells showed a response decrease at increments above a certain maximum (supersaturation response). The averaged contrast/response curve for all neurons was S-shaped in the logarithmic plot, had a dynamic range of 2.5 log units, reached its maximum at a contrast of 0.75 and supersaturated above this level. The contrast/sensitivity curves changed their slope under different stimulus conditions. They became flatter when the non-dominant eye was stimulated as compared to dominant eye stimulation or when the stimulation was done at a non-optimal orientation or direction, and they became steeper when both eyes were stimulated. But the maximum was reached at the same contrast and supersaturation was seen above maximum contrast no matter whether a cell was strongly (e.g. binocular stimulation at optimal orientation) or weakly excited (non-dominant or non-optimal orientation stimulation). After normalization, the averaged population contrast/response curves were virtually identical at all stimulus conditions. It was concluded, that range as well as maximum and supersaturation of cortical contrast/response curves are determined before the input reaches the cortex, and that the cortical cells summate, essentially, linearly. The findings furthermore demonstrate that the supersaturation of the cortical input must be due to subtractive inhibition, and that the same is true for the orientation sensitive inhibition in the cortex itself. Both, the peripheral contrast and the cortical orientation dependent inhibition cannot be explained by multiplicative inhibition. The fact, that the responses of neurons depend on many variables relativates their significance for feature representation.

Animals↗
PubMed1984

Unusual radiologic features of metastatic prostatic carcinoma confirmed by immunohistochemical study.

The clinical application of an immunohistochemical technique for prostatic acid phosphatase allowed the accurate diagnosis of metastatic prostatic carcinoma in 17 patients whose condition was not recognized by either clinical or histologic observations. The cardinal manifestations in these 17 patients included supraclavicular lymphadenopathy in 7, hilar lymphadenopathy in 1, pulmonary infiltration in 2, simulating carcinoma of the rectum in 4, fracture of femur in 1, orbital tumor in 1, and brain tumor in 1. A retrospective analysis of the radiologic features of these patients showed that the unusual manifestations were due to the route of metastasis, that is, direct invasion, lymphatic, and hematogenous. Radiologic studies, even in these unusual cases, are both useful in establishing the diagnosis and helpful in delineating the mode of metastasis of prostatic carcinoma.

Acid Phosphatase↗