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Biomedical subjects

C Y Kuo

Publications and source records attributed to C Y Kuo.

At least 55 records · Page 3Linked to original sources
PubMed1990

Linkage relationship of X-linked juvenile retinoschisis with Xp22.1-p22.3 probes.

Linkage analysis was performed to evaluate the relationship between the locus for X-linked juvenile retinoschisis (RS) and five X-chromosomal markers-RC8 (DXS9), SE3.2L (DXS16), 99-6 (DXS41), D2 (DXS43), and 782 (DXS85)-all mapped to the interval Xp22.1-p22.3. Seven U.S. families with 56 affected males were studied. No recombinants were found between RS and DXS9 with a maximum lod score (Z) of 4.93 at a recombination fraction of zero. Obligate recombinants were found for RS with DXS16, DXS41, DXS43, and DXS85. Multipoint linkage analysis and consideration of recombination events within pedigrees suggest that DXS41 and DXS43, and also DXS41 and DXS16, flank RS and that DXS85 lies outside the interval DXS41-DXS43. Our pedigrees provide no evidence for genetic heterogeneity of RS, with five of our families individually showing evidence of linkage. (Z greater than 2.0) to the least one of these probes from Xp22.1-p22.3.

DNA Probes↗
PubMed1989

Identification of knee joint models for varus-valgus and internal-external rotations: snow skiing experiments.

Sprains at the knee are the most frequent of the severe injuries occurring during alpine snow skiing. This paper discusses the development of analytical models describing rotations across the knee joint caused by varus-valgus and internal-external moments applied at the foot during skiing. Identification of an ARMAX model requires simultaneous measurements of the rotations across the knee and the moments at the foot during skiing. As the models only relate the measured input (moment) and output (rotation) data, they also identify components of apparent rotation resulting from imperfect fixation of the rotation measuring instrument on the test subject and resulting from other inputs. The models identified for all subjects are of order four or five for both varus-valgus and internal-external rotation, and they describe modes with oscillatory and exponentially decaying components. Application of the models to prediction of rotation across the knee from the measured moment at the foot is illustrated by example. A new, and virtually mechanically uncoupled, six degrees-of-freedom, strain gauge dynamometer is developed to record the moments at the foot during skiing. The concept of the dynamometer design has general application.

Humans↗
PubMed1989

Generation of monoclonal antibodies to prostatic acid phosphatase isoenzyme 2 and application in solid-phase enzyme immunoassay.

Monoclonal antibodies specific to prostatic acid phosphatase (PAP) isoenzyme 2 were generated by using an improved hybridoma technique. After three subcutaneous immunizations and three intravenous boosters, cell fusion experiments were performed. The hybrid cells were first cultured in a semisolid medium containing methylcellulose and later transferred to a liquid medium for further subculture. Out of a total of 600 colonies recovered after two cell fusion experiments, 13 were shown to exhibit affinity to PAP isoenzyme 2 by radioimmunoassay. Nine hybrid cell lines which showed high affinity and specificity were established for further evaluation. Their immunoglobulin subclass was determined to be immunoglobulin G. The association constants between PAP isoenzyme 2 and each monoclonal antibody were determined by titration curve in radioimmunoassay (RIA). Three of them (PAP 1, PAP 03, and PAP 019) were shown to be over 1 X 10(9) M-1. From the results of a matrix cross-matching procedure, a pair of antibodies (PAP 03 and PAP 1) reacting with discrete antigenic determinants were identified for preparing a solid phase sandwich enzyme immunoassay (EIA) kit. The designed EIA procedure could be performed within 40 min in a one-stage incubation protocol. The assay time was shorter than that of other commercial RIA or EIA kits, and the sensitivity was 0.4 ng/ml which was comparable to that of RIA kits. The EIA kit was shown not to cross-react with human thyroid stimulating hormone, alpha-fetoprotein, carcinoembryonic antigen, and acid phosphatases derived from tissues other than prostate. Therefore, this design was a simple and rapid method with high sensitivity and specificity for determining PAP isoenzyme 2 in human serum.

Acid Phosphatase↗
PubMed1989

Generation of monoclonal antibodies to alpha-fetoprotein and application in solid-phase enzyme immunoassay.

By using an improved hybridoma technique, monoclonal antibodies specific to alpha-fetoprotein (AFP) were generated. After three subcutaneous immunizations and three intravenous boosters, cell fusion experiments were performed. The hybrid cells were initially cultured in a semisolid medium containing methylcellulose and later transferred to a liquid medium for subculture. Out of 800 colonies recovered after two cell fusion experiments, 16 were shown to exhibit affinity to AFP by radioimmunoassay. Six hybrid cell lines which showed high affinity and specificity were selected for further evaluation. From the results of a cross-matching procedure, two pairs of antibodies (AFP 3 and AFP 05; AFP 3 and AFP 013) reacting with discrete antigenic determinants were identified for preparing solid-phase sandwich enzyme immunoassay (EIA) kits. The association constants between AFP and these three antibodies (AFP 3, AFP 05, and AFP 013) were 2.0, 3.7, and 3.8 X 10(9) M-1, respectively. The immunoglobulin subclass of them was determined to be IgG1. The EIA procedure designed could be performed within 40 min in a one-stage incubation and 70 min in a two-stage incubation. The incubation time was shown to be equal to or shorter than that of any other known commercial kits and the sensitivity was less than 1 IU/ml. In order to avoid the high-dose hook effect which occurred in the one-stage incubation procedure, a two-stage incubation protocol was advised.

Animals↗
PubMed1989

Congenital mesoblastic nephroma: report of a case.

Congenital mesoblastic nephroma (CMN) is a rare renal tumor with a distinct pathology and a unique clinical, therapeutic, and prognostic pattern. The characteristic pathological feature is uniform mesenchymal spindle-shaped cells arranged in interlacing bundles. The prognosis of typical CMN is believed to be excellent by nephrectomy alone. We report a typical case of congenital mesoblastic nephroma which was prenatally detected, and was associated with maternal polyhydramnios.

Humans↗
PubMed1988

Sperm antibodies induced by anti-idiotype antibodies: a strategy in development of immunocontraceptive vaccines.

The potential of using anti-idiotype antibodies as immunocontraceptive vaccines is evaluated in this study. Two sperm monoclonal antibodies, HS 63 and MS 204, which have significant inhibitory effect on the in vitro and in vivo fertilization of mouse were selected to elicit heterologous anti-idiotype antibodies. Rabbit antisera against HS 63 or MS 204 were collected after the third immunization. After the removal of anti-Fc fragments with an irrelevant mouse IgG immunoadsorbent column, anti-idiotype antibodies (anti-Id HS 63 or anti-Id MS 204) were purified from the antisera with affinity chromatography. HS 63 or MS 204 was used as respective ligand. The purified anti-idiotype antibodies conjugated with hemocyanin were used to immunize female CD-1 mice as the experimental group. Another group of female CD-1 mice were immunized with adjuvant only as the control group. Each group had three mice. The immune responses varied significantly among individual mice. The antisera could stain the acrosomal region of sperm in the indirect immunofluorescent assay in a way which is similar to the original monoclonal antibodies (HS 63 and MS 204). The inhibitory effect of antisera on the sperm fertilization of mouse oocytes in vitro was significant in both cases. In the case of antisera against anti-Id HS 63, the control group showed 81.8% and 49.3% of fertilization rates, whereas the corresponding rates of the experimental group were only 35.7% and 20.5%, respectively. Similarly, for antisera against anti-Id MS 204, the experimental group also revealed lower fertilization rates as compared with those of the controls (50.0% vs. 95.8% and 36.8% and 81.3%). The results of this study suggest that anti-idiotype antibodies against HS 63 and MS 204 contain the internal image of the sperm antigen and they could elicit an immune response with a significant antifertility effect. Therefore, they might not only be contributory to further study and understanding of the original antigens in structure and function but also be used as an alternative in the development of immunocontraceptive vaccines.

Animals↗
PubMed1988

Determination of paraquat from formalin-fixed tissue.

In this paper, a sulfuric acid digestion method and a clean-up technique by using cation exchange resin followed by XAD-2 resin has been developed for the determination of paraquat from formalin-fixed tissue at the submicrograms per gram level. Formalin-fixed tissue is dissolved by hot sulfuric acid, then paraquat is isolated and purified with cation exchange chromatography. The eluted paraquat forms an ion-pair with sodium dodecyl sulfate, it is then adsorbed on XAD-2 resin. Paraquat is eluted, extracted and reduced with solvent mixtures, NaCl solution and dithionite reagent, respectively. The calibration graphs of zero-order and second-derivative spectroscopy are linear in the range of 0.01-5.0 mg/kg. The relative standard deviation was less than 5% and the detection limit was 0.02 mg/kg based on 0.5-g samples. The sensitivity of the proposed method could be increased by using larger sample sizes. The method was precise and gave a quantitative recovery of paraquat spiked into formalin-fixed liver homogenates (78%). The proposed method has been satisfactorily applied to the determination of paraquat in the formalin-fixed tissues of suspected poisoned cases. It has been shown to be of great value in the field of forensic toxicology especially when formalin-fixed tissue only is available.

Adult↗
PubMed1984

Surface EMG and torsion measurements during snow skiing: laboratory and field tests.

The relationship between mean rectified EMG (MREMG) measured with surface electrodes and the longitudinal torsion of the lower extremity was investigated in laboratory and snow skiing experiments. Linear regression of the MREMG from the gluteus medius and the peroneus longus with the torsion measured at the foot in the laboratory tests showed that torsion can be predicted with correlation coefficients greater than 0.95 and with a standard deviation less than 5 Nm over all knee flexions and weight bearing. A similar correspondence between MREMG and torsion during skiing does not exist. MREMG is dominantly correlated to posture and body position control functions in skiing. During falling, during ski binding release, and during possible injury sustaining situations, the MREMG was always relatively large, but it was not distinguishable from that associated with smaller torsion of the lower extremity.

Adult↗
PubMed1984

Protease inhibition of natural killer (NK) and antibody-dependent cell-mediated cytoxicity (ADCC) activities.

The ability of protease inhibitors to modulate NK and ADCC cell activities was studied. NK and ADCC cell activities were suppressed by 1,10 phenanthroline (PHE), N-alpha-p-tosyl-L-lysine chloromethyl ketone (TLCK), L-1-tosylamide-2-phenylethylchoromethyl ketone (TPCK), N-benzoyl-DL-tyrosine ethyl ester (BTEE), and phenylethylchoromethyl fluoride (PMSF). The effect of these protease inhibitors on ADCC was not mediated through the early phase of cytotoxicity involving Fc-receptor binding, since they failed to alter EoxA rosetting of effector cells. The results suggest that an activated esterase system might play a role in the later phase of the cytotoxic mechanism by ADCC cells and perhaps NK cells.

Animals↗
PubMed1983

Field measurements in snow skiing injury research.

Field measurements during skiing experiments simultaneously recorded the complete excitation of the toe and heel of one foot, the absolute spatial orientation of the pelvis and the foot, muscle activity at the hip, knee and ankle and the complete rotation of the femur relative to the tibia across the knee in three test subjects. Data were transmitted from test subjects during the skiing experiments by a 100K bits-1. PCM-FM system and recorded in digital form. Analyses of field data show the magnitude of the loading applied to the lower extremity during normal skiing often exceeds the expected, quasi-static ultimate strength of the tibia. Anterior-posterior bending of approximately 600 Nm has been recorded during skiing without binding release or injury to the test subjects. The standard heel binding design can not effectively control the bending moment in the lower extremity during skiing. Longitudinal rotation across the knee was in-phase with, though not proportional to, the applied torsion at the foot by the ski.

Athletic Injuries↗
PubMed1983

Antigens of alternaria. I. Isolation and partial characterization of a basic peptide allergen.

A basic peptide allergen has been isolated from Alternaria extracts. Flat-bed gel preparative isoelectric focusing followed by dialysis and lyophilization allowed for concentration of substantial quantities of this heretofore unrecognized allergen. Rocket immunoelectrophoresis and autoradiography (using a 2 X concentrated, IgE serum fraction from Alternaria patient sera and 125I-anti human IgE), a RAST inhibition assay, and skin testing of Alternaria-sensitive patients were used to demonstrate the allergenicity of this fraction. The allergenicity of this protein was sufficient to give 50% RAST inhibition at a concentration of 100 micrograms/ml using standard RAST procedures. The immunoelectrophoresis autoradiography also indicated allergenicity. Skin tests indicated that over 90% of patients hypersensitive to Alternaria crude extracts were also hypersensitive to the basic allergen fraction.

Allergens↗
PubMed1983

Allergens of Alternaria: further characterization of a basic allergen fraction.

A basic allergen fraction isolated from Alternaria extracts by preparative flat-bed gel isoelectric focusing (as previously reported) was subjected to further characterization. The fraction was chromatographed on a Sephadex G-25 column and exhibited two major peaks, the first of which was allergenic and the second of which was nonallergenic but caused a precipitate to form when added to a mixture of sodium dodecyl sulfate (SDS) (1%) and trichloroacetic acid (5%). SDS-PAGE indicated that the allergen component of the basic fraction migrated at about the same rate as insulin (5.8 kdaltons). Both G-25 peaks were carbohydrate rich with a protein:carbohydrate ratio (by weight) of 1:4.5 and 1:5.8 for peak 1 and peak 2 respectively. Heat (100 degrees C for 10 min) and enzyme digestion (trypsin, alpha-chymotrypsin and pepsin) did not reduce the RAST inhibition values for peak 1 or the original basic fraction. The basic fraction did not bind human IgE specific for birch pollen indicating that the RAST inhibition and IgE (Alternaria specific) binding to radioimmunoelectrophoresis plates was not due to nonspecific binding of IgE. We conclude that the allergenicity of the basic fraction is due to a small molecule that is predominantly carbohydrate in nature and is a major allergen of Alternaria.

Allergens↗
PubMed1982

Effect of fatty acid modification of cultured hepatoma cells on susceptibility to natural killer cells.

Rat hepatoma (Morris 7777) cells modified with either oleic or linoleic acid exhibited greater susceptibility to normal spleen cell-mediated lysis in a 16-hr 51Cr release assay. At effector:target cell ratios of 300:1, the specific lysis of fatty acid-enriched target cells (cultured for 2 days in fatty acid-supplemented medium) by the normal rat spleen cells was 60% higher than the untreated target cells (P less than 0.01). Prolonging the culture in fatty acid-supplemented medium up to 6 days produced similar effects. Analysis of the fatty acid composition of cellular lipids revealed that an elevation of oleic or linoleic acid was the only significant alteration in the hepatoma cells grown in the oleic or linoleic acid-supplemented medium, respectively. The percentage of the acids was increased in the total cellular phospholipids, the choline, ethanolamine, serine, and inositol phosphoglyceride fractions, and the neutral lipids. In conclusion, we suggest that the elevation of oleic acid and linoleic acid contents in the membranes of the fatty acid-modified hepatoma cells may contribute to the increased susceptibility of these cells to natural killer cell-mediated cytotoxicity.

Animals↗
PubMed1980

Cellular and reaginic immune responses to ragweed antigen E in inbred rats.

The cellular and reaginic immune responses to ragweed were examined in six strains of inbred rats. Three differentiable patterns of primary reaginic responses were observed: (a) Lewis rats--good uniform responders--produced high titers of IgE antibody for a short (less than 2 weeks) time; (b) Brown Norway rats--good uniform responders--produced high titers of IgE antibody for a long time (more than 1 month), and (c) intermediate responders--Buffalo, ACI, Fischer 344 and Wistar-Furth rats--produced poor-to-moderate titers of IgE for an intermediate time. There were no secondary reaginic immune responses to ragweed AgE in these six strains of rats. Furthermore, extensive study of Lewis rats indicated that IgE antibody production in primary immunization could be suppressed by passive transfer of either AgE-primed spleen lymphocytes, AgE-primed blood lymphocytes, or Con-A stimulated lymphocytes. Cellular responses to AgE and PHA stimulation were suppressed in rats receiving AgE-primed lymphocytes or Con-A stimulated lymphocytes.

Animals↗
PubMed1979

Subchronic toxicity test for two thermotolerant filamentous fungi used for single cell protein production.

Safety evaluations of two thermotolerant filamentous fungi, Cephalosporium eichhorniae 152 (C. 152) and Rhizopus chinensis 180 (R. 180), grown on a sugar-salts medium were carried out through feeding the biomases to rats at 20% or 40% dietary levels for 90 days. There was a control group fed soybean meal. Weight gain and feed consumption for rats fed 20% C. 152 were equal to those for the control animals, but were depressed in the other three groups, especially the rats fed R. 180. All animals appeared normal and healthy except that transient alopecia was found for a short duration in the fungi-treated rats in the initial period. The cause of this lesion is not clear. At the end of the feeding trial, clinical determinations of constituents in blood and urine samples were conducted. The animals were autopsied and weights for four organs were taken. Histopathological examinations for 26 different tissues were carried out. Mild changes were found in both C. 152 and R. 180-treated rats but most of the these were not considered to be related to treatment.

Acremonium↗
PubMed1978

Studies of the radioallergosorbent test and the lymphocyte stimulation index in symptomatic ragweed pollenosis.

We followed 47 ragweed hay fever patients (not on immunotherapy) through a ragweed season by means of clinical evaluation and symptom scores. The radioallergosorbent test (RAST) and lymphocyte stimulation index (LSI) were done to determine their reliability as predictors of clinical symptomatology. Symptom scores of 10 or above, denoting at least moderate daily symptoms, occurred in 36 patients (80%). Preseasonally, RAST class 2 or above was found in 34 patients (75%), of whom 29 patients (64%) had symptom scores of 10 or above. At that time, LSI was elevated in about 50% of the patients. Patients in RAST class 3 had the highest LSI as a group. Seasonal exposure boosted the LSI in 50% of the patients, whereas 25% were unchanged and 25% showed a decrease. The results suggest that neither RAST nor LSI are reliable predictors of clinical severity in ragweed pollenosis.

Adult↗