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Biomedical subjects

K C Hsu

Publications and source records attributed to K C Hsu.

At least 73 records · Page 4Linked to original sources
PubMed1980

Demonstration of Anaplasma marginale Theiler in Dermacentor variabilis (Say) by ferritin-conjugated antibody technique.

Cattle were inoculated with a Virginia isolate of Anaplasma marginale Theiler and served as an infective source for laboratory-reared Dermacentor variabilis (Say) nymphs. Transstadial transmission of A marginale was demonstrated by feeding the newly molted adult ticks on susceptible cattle and by inoculation of gut homogenates collected from adult ticks at postattachment day 6. A similar gut homogenate from the same group of ticks was caused to react with A marginale-bovine antisera that had been conjugated with ferritin. The homogenate contained organisms similar to those observed in the gut of adult feeding ticks that were infected as nymphs and the labeling of the outer membrane confirmed that organisms observed were A marginale. A gut homogenate prepared from control ticks did not cause infection when inoculated into a susceptible cow and no organisms were demonstrated.

Anaplasma↗
PubMed1979

An unlabeled antibody macromolecule technique using hemocyanin for the identification of type B and type C retrovirus envelope and cell surface antigens by correlative fluorescence, transmission electron, and scanning electron microscopy.

The present resolution (75-100 A) of the conventional scanning electron microscope (SEM) and its ability to image the surfaces of large numbers of whole cells in situ permit the approach of problems such as viral and cell surface antigen localization by immunological labeling with visual markers. Identification of virus and cell surface antigens in situ has been accomplished in indirect reactions by unconjugated markers. Hemocyanin (Hcy) from whelk, Busycon canniculatum, has been developed as an immunospecific marker for virion and cell surface labeling in the electron microscope. Its size (30 x 50 nm) and distinct cylindrical shape permit easy visualization in the SEM and the transmission electron microscope (TEM). The Hcy method involves the preparation of antisera to Hcy in appropriate hosts for use in an unlabeled antibody macromolecule procedure based exclusively on antigen-antibody affinity to couple the macromolecule to the antigen site. Further correlative data from fluorescence microscopy can be obtained from similarly labeled samples by binding fluorescein to the bridging antibodies used in the Hcy technique. The usefulness of the Hcy marker system was demonstrated by employing highly specific antisera to the major envelope and cell surface glycoprotein (gp70) of Rauscher murine leukemia virus (R-MuLV), a type C retrovirus. The antiserum was shown to bind to the virion and cell surfaces of virus-infected cells in the homologous virus-infected cell system. It also demonstrated the expression of R-MuLV gp70-related antigens on a murine cell line Mm5mt/c1 which produces mouse mammary tumor virus (MuMTV), a type B retrovirus. Furthermore, when used in the Hcy marker system the anti-gp70 serum was able to distinguish type B from type C budding virus on the same cell. Methods for the preparation of immunoreagents and labeling of cells are discussed.

Animals↗
PubMed1979

Immunologic techniques for the identification of virion and cell surface antigens by correlative fluorescence, transmission electron and scanning electron microscopy.

The present resolution (75-100 A) of the conventional scanning electron microscope (SEM) and its ability to image the surfaces of large numbers of whole cells in situ permits the approach of problems such as viral and cell surface antigen localization by immunological labeling with visual markers. Identification of virus and cell surface antigens in situ has been accomplished in indirect reactions by conjugated and unconjugated markers. Hemocyanin (Hcy) from whelk, Busycon canniculatum, has been developed as an immunospecific marker for virion and cell surface labeling in the electron microscope. Its size (approximately 30 x 50 nm) and distinct cylindrical shape permit easy visualization in the SEM and TEM. The Hcy method involves the preparation of antisera to Hcy in appropriate hosts for use in an unlabeled antibody macromolecular procedure based exclusively on antigen-antibody affinity to couple the macromolecule to the antigen site. Further correlative data from fluorescence microscopy can be obtained from similarly labeled samples by binding fluorescein to the bridging antibodies used in the Hcy technique. The usefulness of the Hcy marker system was demonstrated using antisera to the major envelope and cell surface glycoprotein (gp70) of Rauscher murine leukemia virus (R-MuLV), a type C retrovirus. The antiserum was shown to bind to the virion and cell surfaces of virus-infected cells in the homologous virus-infected cell system. It also demonstrated the expression of R-MuLV gp70-related antigens on a murine cell line Mm5mt/c1 which produces mouse mammary tumor virus (MuMTV), A type B retrovirus. Furthermore, when used in the Hcy marker system this antiserum was able to distinguish type B from type C budding virus on the same cell. Examples of other marker systems (ferritin, peroxidase, colloidal gold, and latex) used to show anti-gp70 serum reactivity will be presented to demonstrate their applicability to cell surface labeling studies. Methods for the preparation of immunoreagents and labeling of cells are discussed.

Animals↗
PubMed1979

Bone marrow acid phosphatase in prostate cancer: an assessment by immunoassay and biochemical methods.

Comparisons of the bone marrow and serum acid phosphatase values obtained by counterimmunoelectrophoresis and the Roy biochemical test were made in 72 patients with and in 13 patients without prostatic cancer. The counter-immunoelectrophoresis test, when positive at more than 1 international unit per liter, showed only 4.4% falsely positive results. The Roy biochemical test, which uses sodium thymolphthalein monophosphate as the substrate, had 65% falsely positive bone marrow acid phosphatase levels. Conflicting reports regarding the value of bone marrow acid phosphatase determinations in patients with prostatic cancer result from the use of non-specific substrates in biochemical methods for measurement and from the trauma incidental to bone marrow aspiration, which releases many non-prostatic acid phosphatase enzymes. The use of immunoassay such as counter-immunoelectrophoresis minimizes this source of error.

Acid Phosphatase↗
PubMed1978

Susceptibility of human skeletal muscle culture to influenza virus infection. I. Cytopathology and immunofluorescence.

We found that fused human muscle in culture supports neurotropic influenza A viral infection, as demonstrated by viral growth experiments, hemadsorption, observation of cytopathic changes and detection of intracellular viral antigen. The time of peak virion production and the appearance of cytopathic effects in these experiments were similar to previously described characteristics in influenza A-susceptible organotypic cultures of other tissues. Cytopathological changes occurred earlier in mononucleated cells than in myotubes and included cell-rounding; cytoplasmic retraction, granularity and vacuolization; ribonucleic acid-containing cytoplasmic inclusions; nucleolar enlargement; and clumping of chromatin. Immunofluorescent staining demonstrated early nuclear fluorescence, followed by spread of viral antigen into the cytoplasm. A subpopulation of mononucleated cells, shown by cloning studies to be myoblasts, showed no cytopathic effects or evidence of intracellular viral antigen and was presumably resistant to neurotropic influenza A infection. The adverse effects of influenza A on fused human muscle cells in tissue culture contrast with the inability of the virus to replicate in skeletal muscle after animal inoculation in acute experiments. Therefore, host factors may affect attempts to produce an animal model of human muscle disease with this virus.

Cell Nucleus↗
PubMed1978

Susceptibility of human skeletal muscle culture to influenza virus infection. Part 2. Ultrastructural cytopathology.

Cultured post-fused human skeletal muscle monolayers exposed to WSN influenza A virus were analyzed by scanning and transmission electron microscopy. At 12-14h post-inoculation (p.i.), affected mononuclear cells retracted from the cell surface, but remained anchored to the substrate by taut filar processes. Retraction was accompanied by shortening of microvilli, appearance of hemispherical cytoplasmic protrusions and corrugation of the surface proper. These changes were more pronounced at 24 and 48h p.i. The rounded, moribund mononuclear cells eventually detached from the substratum. Surface alterations were accompanied by the intracellular appearance of electron-dense nuclear inclusions (often associated with the nucleolus) and paracrystalline ribosomestudded cytoplasmic bodies, which increased in size and number with time. In myotubes, distinct surface alterations appeared later (24h p.i.). Early myotube retraction was accompanied by accentuation of the longitudinally oriented surface pleats and appearance of "blebs" followed by cell-rounding. At 48-72 h, many myotubes detached from the substratum. The surfaces of those still adhering appeared corrugated. Intranuclear and cytoplasmic inclusions accumulated, and budding virions, often filamentous, could be demonstrated at the plasmalemma of mononuclear cells and myotubes. Late (end-stage) cytopathic effects included clumping of chromatin, breakdown of the nuclear envelope, disappearance of cortical and endoplasmic cytofilaments, mitochondrial swelling, and vesiculation of surface membranes. The lesions leading to cell injury and cell death appeared to be due to massive accumulation of virus-induced products that altered cellular metabolism, with physical and functional abnormalities of surface membranes.

Autoradiography↗
PubMed1978

Counter immunoelectrophoresis for detection of human prostatic acid phosphatase.

An immunochemical method for detection of prostatic acid phosphatase is described. Acid phosphatase was obtained from benign human prostatic tissue. A specific antiserum to this enzyme was produced in rabbits. A counter immunoelectrophoretic method utilizing the specific antiserum with a chemical staining technique has been developed. Clinical trials have indicated the usefulness of this method for the specific determination of prostatic acid phosphatase.

Acid Phosphatase↗
PubMed1978

Ultrastructural localization of anaplasmal antigens (Pawhuska isolate) with ferritin-conjugated antibody.

Antibodies from a cow with an experimentally induced infection of the Pawhuska isolate of bovine anaplasmosis were conjugated with ferritin and used to label antigenic sites in preparations of parasitized erythrocytes. Intact erythrocytes did not label on the extracellular surface. Ferritin-conjugated antibody did not pass through the intact erythrocyte to label the parasite, probably due to the large molecular size of the antibody. Damage to erythrocytic plasmalemma and inclusion body in the hemolyzed erythrocytes and complement-fixation antigen allowed labeling of anaplasmal inclusion structures. The positively labeled structures were outer surface of the pellicle, chromatin of the initial body, and inclusion appendage. Unlabeled structures included inner organismic membrane of the initial body, inclusion membrane, fibrillar protoplasmic network of the initial body, and small electron-dense bodies derived from the initial body.

Anaplasma↗
PubMed1977

Novel method for estimating the labeling index in clinical specimens with the use of immunoperoxidase-labeled.

The labeling index determined by [3H]thymidine autoradiography in cells from clinical specimens was compared with the percentage of the cells showing nuclear reactivity to immunoperoxidase-labeled antinucleoside antibodies. This nuclear immunoreactivity is specific for denatured or single-stranded DNA's and is detectable almost exclusively during DNA synthesis. Results with the two methods showed excellent agreement. The new method allowed rapid accurate assessment of S phase in the tumor cells from freshly isolated aspirated specimens as well as frozen sections, suggesting general applicability to estimation of the labeling index without autoradiography.

Adenocarcinoma↗
PubMed1976

Murine influenza virus encephalomyelitis. III. Effect of defective interfering virus particles.

Defective interfering influenza virus particles lessened the yield of infective virus recovered from brain after intracerebral challange of 3-week old mice, but failed to affect the appearance of disease or lethality. In 7-week old mice, the presence of defective interfering influenza virus particles reduced both lethality and virus yield. Viral inocula containing significant numbers of defective particles appeared to diminish later inflammatory changes, nerve cell degeneration and the appearance of viral antigen in deeper cerebral regions. The protective effect exerted by defective virus particles does not appear related to interferon production in brain.

Age Factors↗
PubMed1976

Angiotensin-converting enzyme: vascular endothelial localization.

Fluorescein-labeled antibody to rabbit pulmonary angiotensin-converting enzyme localized in the vascular endothelium of rabbit lung, liver, adrenal cortex, pancreas, kidney, and spleen. Epithelial cells of the renal proximal tubules were the only parenchymal cells among the organs studied that demonstrated immunoreactivity.

Adrenal Cortex↗
PubMed1976

Immune complex orchitis in vasectomized rabbits.

The results of the present study show that bilaterally vasectomized rabbits with high levels of antibodies to sperm antigens frequently develop an orchitis associated with granular deposits of rabbit IgG and C3 in the basement membranes of seminiferous tubules. The immune deposits correspond in location to electron-opaque deposits seen by electron microscopy. The "membranous orchitis" is characterized by thickening of tubular basement membranes, acc-mulation of macrophages and a few polymorphonuclear leukocytes, and destruction of the basal lamina, of the Sertoli and spermatogenetic cells. The pathogenetic role of the immune deposits and the possibility that they contain antigen-antibody complexes is indicated by: (a) selective accumulation of IgG and C3 granular deposits along the basement membranes of seminiferous tubules in rabbits producing high and persistent levels of antibodies to sperm antigens; (b) the elution of immunoglobulins from tissues with chaotropic ion-containing buffers, acid buffers, or heat; (c) the observation that the immuno-globulins accumulated in the testis contain antibody to sperm antigens; and (d) the demonstration of sperm antigens in a location similar to that of IgG and C3. It is postulated that sperm antigen-antibody complexes are formed in the basement membranes of seminiferous tubules when antigens leaking out of the tubules react with specific antibody coming from the circulation. In two rabbits with higher levels of circulating antisperm antibodies and severe orchitis, granular deposits of IgG and C3 were also present in renal glomeruli. Immunoglobulins eluted from the kidneys contained antibody with antisperm activity. These findings are consistent with the hypothesis that in some vasectomized rabbits extratesticular lesions may develop by a mechanism comparable to that of chronic serum sickness.

Animals↗