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Biomedical subjects

T C Chow

Publications and source records attributed to T C Chow.

45 records · Page 3Linked to original sources
PubMed1989

Clear cell chondrosarcoma: case report and ultrastructural study.

A case of clear cell chondrosarcoma in a Chinese patient is described. The clear cells showed strongly positive S-100 protein immunoreactivity. Ultrastructurally 2 types of chondroid cells were demonstrated. One type appeared more primitive with abundant electron-lucent cytoplasm and sparse organelles. The other type of cell was more differentiated with presence of microvilli and numerous dilated cisternae of endoplasmic reticulum. Previous ultrastructural studies on these lesions were reviewed and compared with the present findings.

Adult↗
PubMed1987

Prostatic-type polyps of the lower urinary tract: three histogenetic types?

Seventeen prostatic-type polyps of the lower urinary tract are reported. All occurred in males, and the mean ages of the patients with ureteric orifice, bladder and urethral polyps were 20.5, 60.2 and 36.6 years, respectively. The commonest presentation for the bladder and ureteric orifice polyps was haematuria, whereas that for the urethral polyps was either dysuria or haematuria. The polyps consisted of acini and papillae lined by prostatic-type epithelium, as confirmed by immunostaining for prostatic-specific antigen. Most had interspersed islands or complete covering of transitional epithelium on the surface. We believe that the histogenesis of prostatic-type polyps may differ in the different sites. For the ureteric orifice polyp, the early age of presentation and the simple occurrence of prostatic acini beneath an intact urothelium suggest a developmental abnormality. For the bladder polyp, the late onset of disease and the commonly observed transition with cystitis cystica-glandularis suggest that it may be a metaplastic variant of cystitis cystica-glandularis. On the other hand, the urethral polyp probably represents a hyperplastic lesion, since the prostatic urethra is normally lined partly by prostatic-type epithelium.

Adolescent↗
PubMed1986

Fetal echocardiography: results in high-risk patients.

The results of 140 fetal cardiac scans in 124 high-risk obstetric patients (16 to 40 weeks' gestation) are presented. Sixty patients were scanned for high genetic or environmental risk (group 1); 31 because of fetal abnormality detected on routine ultrasound scanning (group 2) and 37 because of arrhythmias (group 3). Three patients were in two groups. The standard echocardiography views, ie, long-axis, great vessel short axis, four chamber, and aortic arch were obtained in 72, 95, 96, and 55%, respectively. All scans in group 1 were diagnosed as normal. In group 2, complex cardiac abnormalities were detected, the presence of fetal cardiac failure and its cause were clarified, and serious cardiac malformations were excluded. Arrhythmias in group 3 were diagnosed correctly and fetal hemodynamics assessed. A small number of lesions were not detected or diagnosed. The factors interfering with detection of lesions were abnormalities of the intrathoracic or abdominal cavity, inadequate amniotic fluid, and size of lesions. Major cardiac structures or abnormalities could be identified, and abnormal hemodynamics caused by arrhythmias and structural lesions assessed. Unnecessary intervention was prevented in five cases and conversely the need for acute intervention was indicated in seven cases. Fetal echocardiography remains a specialized investigation that has an important role in the management of some high-risk pregnancies.

Arrhythmias, Cardiac↗
PubMed1980

Interaction of herpesvirus with spleen cell subpopulations comparison of a neurotropic and a lymphotropic virus.

We studied the interaction of a neurotropic herpesvirus, herpes simplex virus type 1 (HSV-1) or type 2 (HSV-2), and a lymphotropic herpesvirus, guinea pig herpes-like virus (HLV), with guinea pig spleen cells. Both HSV-1 and HSV-2 and HLV can attach to and penetrate into B- or T-enriched cells. Less than 1.4% of the total B- or T-enriched cell populations were susceptible to infection by HLV and to some degree to HSV-1 or HSV-2 as determined by infectious center assays. After specific antiserum treatment, higher titers of intracellular virus were detected in HLV-infected cells than in HSV-1- or HSV-2-infected cells. Both B-enriched and T-enriched cells could support HLV replication, but not that of HSV-1 or HSV-2. The replication of HSV-1 was demonstrated in guinea pig spleen cells pretreated with lipopolysaccharide but not with phytohemagglutinin. Furthermore, when cells were separated into B- and T-enriched cells, the B- enriched cells prestimulated with lipopolysaccharide were susceptible to HSV-1 replication, whereas the T-enriched cells prestimulated with phytohemagglutinin were not. The differences observed in vitro in the interactions of these two herpesviruses with guinea pig spleen cell subpopulations may provide a basis for understanding the differences observed in vivo in the pathogenesis of these two viruses; i.e., HLV is capable of infecting and persisting in guinea pig lymphocytes, whereas HSV is not.

Animals↗
PubMed1980

Hemagglutinin and neuraminidase specific cell-mediated immune responses to influenza A virus following immunization in guinea pigs.

Groups of guinea pigs were immunized with different inactivated recombinant influenza A viruses including H3ChN2Ch, Heq1N2Ch, H3ChNeq1 or uninfected allantoic fluid. Employing hemagglutination and neuraminidase inhibition tests, an in-vitro lymphocyte transformation (LTF) assay, and rosetting techniques for the separation of lymphocytes, influenza hemagglutinin (HA) and neuraminidase (NA) specific antibody and cell-mediated immune (CMI) responses were evaluated. Inactivated H3ChN2Ch, H3ChNeq1, HavN2Ch, and Heq1Neq1 recombinant influenza viruses were used as test antigens. Following immunization the CMI and antibody responses to influenza were characterized by the induction of specific LTF and antibody activity to homotypic HA or NA antigens but not to heterotypic HA or NA antigens. The temporal kinetics of the antibody response to influenza antigens was characterized by a prompt onset being initially detected at 1-2 weeks and reaching peak titers 3-4 weeks after immunization. Influenza specific LTF responses were first detected one week after immunization and declined to minimal responses at eight weeks. T-lymphocytes but not B-lymphocytes were capable of in-vitro recognition of the HA and NA antigens. After recognition the subsequent in-vitro lymphoproliferation was shown to involve both T and B lymphocytes.

Agglutinins↗
PubMed1979

Cell-mediated immune responses to the hemagglutinin and neuraminidase antigens of influenza A virus after immunization in humans.

Humoral and cell-mediated immunity (CMI) were evaluated in groups of school children after immunization with inactivated influenza virus vaccines. A conventional biphasic strain (H3ChN2Ch) of Port Chalmers influenza virus (X-41), a recombinant influenza virus specific for the neuraminidase antigen (Heq1N2Ch) of Port Chambers influenza A virus (X-42), and a placebo were employed for immunization. The techniques of hemagglutination inhibition and neuraminidase inhibition were used to determine serum antibody titers. The CMI responses were evaluated by the in vitro lymphocyte transformation assay employing HavN2Ch, Heq1Neq1, H3ChNeq1, and H3ChN2Ch influenza A virus strains as stimulants. Specific HAI antibody and CMI responses to H3Ch were observed in X-41 but not in X-42 vaccinees. Specific anti-neuraminidase antibodies and CMI responses to N2Ch were manifested by both X-41 and X-42 vaccinees. Immunization with the placebo resulted in no influenza-specific immune responses. The CMI response was first detectable 10 days after immunization and then declined. These observations demonstrate the induction of CMI responses to the HA and NA influenza surface antigens after immunization. These responses may be important in antiviral immunity and the recovery from influenza infection.

Antibodies, Viral↗
PubMedDate not supplied

Ultrastructural observations on Penicillium marneffei in natural human infection.

The ultrastructure of Penicillium marneffei and the host response to the infection were studied in two patients. One was immunocompetent and the other an immunosuppressed renal graft recipient. In the immunocompetent patient it was observed that all the yeast cells were phagocytosed and were found either within membrane-bound vacuoles or lying freely within the cytoplasm of the macrophages. It was postulated that continuous lysosomal fusion with the phagolysosomes and multiplication of the fungi within the phagocytic vacuoles might eventually lead to the rupture of the vacuoles with release of the organisms into the cytoplasm of the macrophages. In the second patient, the immunosuppressive effects of corticosteroids might account for the large number of nonphagocytosed fungi in the tissue space, and the failure to form large phagocytic vacuoles.

Adult↗