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Biomedical subjects

K Huang

Publications and source records attributed to K Huang.

At least 181 records · Page 10Linked to original sources
PubMed1989

Characterization of two monoclonal antibodies that recognize high molecular weight colon antigens.

Two monoclonal antibodies, M32-1 (Ig-G1,k) and M39-2 (IgM,k), were prepared against high molecular weight (greater than 650 kDa) cytosol antigens (HMW-CA) of a human adenocarcinoma of the colon (GW-39). These monoclonal antibodies appeared to bind to determinants on two distinct high molecular weight colon antigens. One was shown by gel filtration to be a 650 kDa glycoprotein (gp650) containing at least one 300 kDa antigenic subunit (gp300). The other antigen eluted from a S-300 Sephacryl column at a molecular size of 600 kDa (gp600) and was resistant to dissociation by detergents, salts and chaotropic agents. The differential sensitivity of these two high molecular weight glycoproteins to treatment with trypsin, chondroitinase ABC, HNO2, endoglycosidase H and 2-mercaptoethanol suggest that monoclonal antibodies M39-1 and M39-2 react with distinct antigenic determinants located on two separate, high molecular weight, colon antigens. Since these antigens are only detected in extracts prepared from normal mucosa, well-differentiated tumors or margins of well-differentiated tumors, their expression appears to be related to a well-differentiated cell phenotype.

Adenocarcinoma↗
PubMed1988

Effect of ionizing radiation on thymic epithelial cell function. I. Radiation-spared thymic epithelial grafts expedite the recovery of T cell function in lethally irradiated and fetal liver reconstituted mice.

A murine model system was developed to determine whether ionizing radiation has a detrimental influence on thymic epithelium, cell function. Normal mice were lethally irradiated, grafted intracamerally with normal fetal thymic epithelium, and then reconstituted with fetal liver cells. These animals were compared with a group of animals who received their thymic grafts before the irradiation protocol. Analysis of the reconstitution of T cell function in peripheral lymph nodes and spleens at various times post transplantation demonstrated that animals with radiation-spared thymic grafts had superior proliferative responses to T cell mitogens and alloantigens. It was also determined that the capacity of these animals to elicit contact hypersensitivity responses was significantly greater when compared with animals whose thymic grafts had been radiated. The observed difference in T cell function could not be ascribed to a difference in the rate of export of mature T cells from the thymic grafts since the absolute number of Thy-1+, L3T4+, or Lyt-2+ lymphocytes present in the peripheral lymphoid compartment of our two groups of animals was equivalent. Immunohistologic analysis of the thymic grafts demonstrated a marked reduction in the medullary compartment of the repopulated grafts that had been exposed to ionizing radiation. The results of this study suggest: 1) that irradiation of the thymic microenvironment during marrow ablative preparative regimens may be in part responsible for some of the immune alterations observed in marrow transplant recipients, and 2) that our model system may provide a valuable tool for delineating the roles played by medullary and cortical epithelial cells of the thymus on the T cell maturation and education processes.

Animals↗
PubMed1986

Isolation and characterization of human factor VIII: molecular forms in commercial factor VIII concentrate, cryoprecipitate, and plasma.

Human factor VIII has been isolated from a high purity factor VIII concentrate by immunoaffinity chromatography and HPLC on Mono Q gel. Two fractions of factor VIII were obtained with a specific activity of approximately equal to 7000 units/mg. The major fraction contained eight peptide chains of 200, 180, 160, 150, 135, 130, 115, and 105 kDa plus one doublet chain of 80 kDa. The minor fraction contained one peptide chain of 90 kDa plus the chain of 80 kDa. Both fractions were activated by thrombin to the same extent. Amino-terminal amino acid sequence analysis was performed on the 180-kDa, 130-kDa, and 90-kDa chains and showed an identical amino-terminal sequence in these chains. Each chain from 200 kDa to 90 kDa was linked to one 80-kDa chain by a metal-ion bridge(s). Studies on factor VIII in plasma and cryoprecipitate, prepared and gel filtered in the presence of protease inhibitors, showed that one 200-kDa plus one 80-kDa chain were the only or dominating chains in the materials and may represent native factor VIII. The results indicated that all chains from 180 kDa to 90 kDa are fragments of the 200-kDa chain. All of these more or less fragmented chains form active factor VIII complexes with the 80-kDa chain.

Amino Acid Sequence↗
PubMed1985

A demonstration of two distinct geniculocortical projection patterns in albino ferrets.

The geniculocortical pathways of albino ferrets have been studied by injecting lectin bound horseradish peroxidase into the visual cortex and then studying the geniculate distribution of retrogradely labelled cells in the dorsal lateral geniculate nucleus. It has been shown that in ferrets, as in Siamese cats, there are two quite distinct patterns of geniculocortical projection. One of the patterns seen in ferrets is comparable to the 'Midwestern' pattern previously described in Siamese cats, while the other is comparable to the 'Boston' pattern.

Albinism↗
PubMed1985

Binswanger's disease: progressive subcortical encephalopathy or multi-infarct dementia?

Since Binswanger's description of subcortical arteriosclerotic encephalopathy in 1894, numerous cases have been reported. Several authors doubt the validity of this malady, although the majority consider it to be a disease entity. We report seven cases with this type of pallor of myelin, only two of which are accompanied by a history of dementia. Among the seven cases, two had arteriosclerosis of penetrating arteries and arterioles in cerebral white matter. Electron microscopy showed splitting of myelin sheaths, probably the result of edema. In reviewing the blood supply of the cerebral white matter, we conclude that no pathological alterations of medullary branches of the cerebral arteries, the same vessels supplying the white matter, can give rise to such diffuse pallor of white matter and spare the arcuate fibres. This pallor can only be due to cerebral edema, most likely of hypoxic-ischemic, hypotensive, or acidotic origin. We also contend that arteriosclerosis can only cause dementia through multiple infarcts or lacunae, if it indeed leads to dementia.

Aged↗
PubMed1985

The influence of retinal afferents upon the development of layers in the dorsal lateral geniculate nucleus of mustelids.

The extent to which the development of a normal laminated lateral geniculate nucleus depends upon retinal afferents has been studied in normal and albino ferrets and in mink. Removal of all retinal afferents before they invade the nucleus (28 days in utero) or before they establish distinct monocular terminal fields (newborn, approximately 41 days post-conception) produces a nucleus that is smaller than normal and poorly separated from the adjacent perigeniculate and medial interlaminar nuclei. However, the nucleus is wedge-shaped, resembling a normal adult nucleus, in which a broad medial binocular segment is distinguishable from a narrower lateral monocular segment. There is a normal mediolateral gradient of cell sizes and some signs of a laminar differentiation, cells next to the optic tract being morphologically distinguishable from cells near the optic radiation, but no cell-free interlaminar zones are formed. The development of a monocularly innervated nucleus depends on the size of the surviving retinal input. In normally pigmented ferrets or mink the crossed retinofugal component is larger than the uncrossed component. In the monocular animals one sees essentially a monocular set of geniculate layers on each side, with an appropriate asymmetry. Each nucleus can be regarded as representing the survival of those layers which would have been innervated by the good eye, together with some additional geniculate territory that appears to be added to the surviving layers as retinogeniculate axons occupy territory normally innervated by the other eye. The crossed component of an albino ferret is abnormally large and the monocularly innervated contralateral nucleus is almost like that of a normal albino. There is a full complement of geniculate layers and interlaminar zones, which appears to develop without any binocular interactions. The ipsilateral retinogeniculate component of albinos is extremely small. In the monocular albino animals it forms discontinuous terminal patches, leaving sectors of the poorly differentiated nucleus uninnervated. These results show that in geniculate development there is a limited interaction between the two sets of retinal afferents. Each set plays a well defined and distinctive role, and one can replace the other to a limited extent only.

Afferent Pathways↗
PubMed1984

Spongy degeneration of the CNS in infancy.

We studied six cases of spongy degeneration of the CNS in infancy among Chinese. The main clinical features were cyclical vomiting and wailing, blindness, megalocephaly, convulsions, lethargy, and coma. Chief findings from light microscopic studies were spongiform change, moderate outfall of neurons, and marked astrocytosis, with formation of Alzheimer's cells type 2. Demyelination was only slight, if present. Electron microscopic studies revealed membrane-bound vacuoles, often containing membranous fragments or blisters and electron-dense granules.

Asian People↗
PubMed1983

Adult spinal muscular atrophy. A report of four cases.

Four cases of spinal muscular atrophy (SMA) are reported, 3 with detailed autopsy findings. These are compared with 2 cases of typical amyotrophic lateral sclerosis (ALS) with neuropathological data. The 3 autopsy cases of SMA only showed decreased numbers of anterior horn cells in the spinal cord, with no change in the cortical pyramidal cells, including the Betz cells, and no degeneration of the pyramidal tracts, while the ALS cases showed loss both of lower and upper motor neurons and degeneration of the pyramidal tracts. In our opinion, the infantile, juvenile, adult, and late-life forms of SMA are really a single disease entity that occurs at varying ages and is separate from ALS. The term lower motor neuron disease would be preferable because the lesions are not limited to the spinal cord, but also occur in the brain stem.

Adult↗
PubMed1979

Vitrectomy in experimental endophthalmitis: Part I-Fungal infection.

In studying the dose-related ocular toxicity of amphotericin B in vitrectomized eyes, up to 5 micrograms/0.1 ml concentration of amphotericin C was nontoxic to the ocular structure when injected in the anterior part of the vitreous cavity. Intravitreal injection of 2.5 micrograms of amphotericin B halted fungal endophthalmitis, which was experimentally induced in rabbit eyes, even after 16 days of infection. Combined treatment of vitrectomy and intravitreal injection of amphotericin B not only cured the fungal endophthalmitis but it also cleared the ocular media from opacities.

Amphotericin B↗
PubMed1977

Tyzzer's disease in Syrian hamsters.

Tyzzer's disease was diagnosed in 18 Syrian hamsters. The clinical signs included sudden onset of diarrhea, dehydration, and lethargy; all affected hamsters died within 48 hours. Gross lesions consisted of multiple white nodules in the heart; dilated cecum and colon containing semiliquid feces, sometimes bearing necrotic plaques on the mucosa; and occasionally, a few small scattered white spots in the liver. Microscopic study of those lesions revealed areas of necrosis and mixed cellular inflammation. The causative agent, Bacillus piliformis, was demonstrated within myocardial fibers, hepatocytes, and colonic epithelial cells. Inoculation of chicken embryos and a clinically normal hamster with a homogenate of cecal wall prepared from affected hamsters resulted in reproduction of the agent and transmission of the disease.

Animals↗
PubMed1977

Effect of interferon on phagocytosis.

The observation on the in vitro phagocytosis-enhancing effect of mouse interferon has now been confirmed in the same host system and expanded to the human system. Morphological and cytochemical evidence of the activated state of mouse macrophages has also been reported. The interferon-elicited enhanced state of macrophages has been demonstrated in intact animals. The exact mechanism of the macrophage-enhancing effect of interferon remains to be elucidated.

Animals↗