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Biomedical subjects

S Hosoi

Publications and source records attributed to S Hosoi.

At least 73 records · Page 4Linked to original sources

Specific IgG antibodies to Dermatophagoides pteronyssinus and egg white--their changes with age.

Dermatophagoides pteronyssinus-specific and egg white-specific IgG in 232 children and 42 adults were measured by the RAST method using monoclonal anti-human IgG antibodies (HG2-25) as the secondary antibody. Changes in allergen-specific IgG with the age of the subjects were examined. Allergen-specific IgG antibody in standard serum was designated as 1,000 U/mL. Standard curves were made for each measurement and the levels of allergen-specific IgG of the sera were expressed in units (U). Dermatophagoides pteronyssinus-specific IgG increases from 9 months of age until adulthood. The atopic group showed higher mean values than the non-atopic group (r less than .001). Egg white-specific IgG reaches a peak around 3 to 4 years of age. After this, it declines until adulthood. These results suggest that age factors and allergen factors must be taken into consideration when evaluating allergen-specific IgG antibodies.

Adolescent↗

Monoclonal anti-human IgG antibodies for quantitation of allergen-specific IgG in human sera.

Eight monoclonal anti-human IgG antibodies were fully characterized and evaluated as possible reagents in solid phase radioimmunoassay for quantitating allergen-specific IgG antibody. Four monoclonal antibodies (HG24D, HG2-14, HG2-18, and HG2-25) recognize CH2 domain of human IgG and bind to human IgG fixed to microtiter plate with high affinities. These monoclonal antibodies were more suitable than polyclonal rabbit anti-human IgG antibody in Phadebas RAST for honey bee venom-specific IgG antibody. Nonspecific binding was much lower, and the slopes of standard curves were much steeper. In contrast to polyclonal antibody, the standard curve was hardly influenced by human serum IgG in sample diluent. These advantages of monoclonal antibodies that recognize CH2 domain of human IgG made it possible to quantitate egg white- and Dermatophagoides pteronyssinus-specific IgG antibodies with use of allergen disks prepared for IgE RAST. This property allows a single system to be used for measurement of IgG and IgE antibodies against clinically relevant allergens.

Allergens↗

Membrane voltage, resistance, and channel switching in isolated mouse fibroblasts (L cells): a patch-electrode analysis.

The whole-cell patch-electrode technique of Fenwick, Marty & Neher (1982) has been applied to single suspension-cultured mouse fibroblasts. Seals in the range of 10-50 G omega were obtained without special cleaning of the cell membranes. Rupture of the membrane patch inside the electrode was accompanied by a shift of measured potential into the range -10 to -25 mV, but in most cases with little change in the recorded resistance. The latter fact implied that the absolute resistance of the cell membrane must be in the same range as the seal resistance and the recorded potential is a poor measure of actual cell membrane potential. Steady-state current-voltage curves (range -160 mV to +80 mV) were generated before and after rupture of the membrane patch, and the difference between these gave (zero-current) membrane potentials of -50 to -75 mV, which represents a leak-corrected estimate of the true cell-membrane potential. The associated slope conductivity of the cell membrane was 5-15 microS/cm2 (assumed smooth-sphere geometry, cells 13-15 microns in diameter) and was K+-dominated. With 0.1 mM (or more) free Ca2+ filling the patch electrode, membrane potentials in the range -60 to -85 mV were observed following patch rupture, with associated slope conductivities of 200-400 microS/cm2, also K+-dominated. Similar voltages and conductivities were observed at the peak of pulse-induced 'hyperpolarizing activation' (Nelson, Peacock, & Minna, 1972), and the two phenomena probably reflect the behaviour of Ca2+-activated K+ channels. Both the pulse-induced conductance and the Ca2+-activated conductance spontaneously decayed, the latter over periods of 5-15 min following patch rupture. Sr2+, Ba2+, and Co2+ could also activate the putative K+ channels, but only Sr2+ really mimicked Ca2+. Co2+ and Ba2+ activated with a delay of several minutes following patch rupture, and deactivated quickly with a small decrease of conductance and a large decrease of membrane potential. Evidently, Co2+ and Ba2+ affect channel specificity as well as channel opening and closing kinetics.

Action Potentials↗

The use of monoclonal antibodies in demonstrating the effect of antibody heterogeneity on immune complex size.

The effect of antibody heterogeneity on immune complex size was investigated by using monoclonal antibodies. Five monoclonal antibodies which bind different antigenic determinants of human serum albumin were used to produce immune complexes. When one or two different monoclonal antibodies were used, under antigen-excess, antigen-antibody equivalent, and antibody-excess conditions, hardly any immune complexes larger than mouse IgM were produced. On the other hand, in a representative experiment, when five different monoclonal antibodies were used, immune complexes larger than mouse IgM comprised 21.5% of the total antigen under antigen-antibody equivalent conditions, 18.2% under antibody-excess conditions, and 4.3% under antigen-excess conditions. These results indicate that antibody heterogeneity is one of the important factors determining immune complex size.

Animals↗

Bronchial and intercostal angiography with ioxaglate and diatrizoate in man. A comparative investigation.

A low osmolality contrast medium, ioxaglate, was compared with diatrizoate of high osmolality in selective bronchial and intercostal angiography. The frequency and degree of pain, heat sensation, cough and involuntary movement were significantly lower with ioxaglate. In addition haemodynamics recorded in 17 cases of bronchial angiography revealed that ioxaglate induced significantly less effect on systemic blood pressure and heart rate.

Aged↗

Analysis of antigenic expression by primary and autologous metastatic human sarcomas using murine monoclonal antibodies.

The efficacy of monoclonal antibody therapy depends in part on the expression of the relevant tumor-associated antigens by both primary tumors and their metastases. Antigen expression by paired primary and autologous metastases from surgically excised osteogenic and soft-tissue sarcomas from 15 patients was studied using a panel of murine hybridoma monoclonal antibodies and indirect immunoperoxidase staining of formalin-fixed tissue sections. The panel included three antibodies (B3619, 17-9H3, OST6) recognizing sarcoma-associated antigens and an antibody recognizing an HLA-DR framework determinant (OKla1). In most cases, antibody binding to both primary and metastatic tumors was observed. However, marked heterogeneity of binding intensity between primary and metastatic tumors and of cells expressing antigens within tumors was noted. This occurred even though primary and metastatic tumors demonstrated homogeneous histology and cellular morphology. Differences were noted among patients as well as among metastases taken from an individual. A significant number of both primary and metastatic tumors contained cells that did not bind a particular antibody even in the presence of other cells that demonstrated significant antibody binding. Thus, strategies for single monoclonal antibody therapy may be limited by heterogeneity of intertumor and intratumor antigenic expression.

Animals↗

In vivo radiolocalization of antiosteogenic sarcoma monoclonal antibodies in osteogenic sarcoma xenografts.

Monoclonal antibodies Ost6 and Ost7 (mouse Immunoglobulin G1) to human osteogenic sarcoma were isolated from ascitic fluid and labeled with radioiodine. After injection into athymic nu/nu mice with s.c. xenografts of human osteogenic sarcoma, the uptake of radioactivity in tumors, visceral organs, and blood was determined. Five days after injection, Ost6 and Ost7 showed preferential accumulation in tumors (tumor:blood ratio, 4.3). Furthermore, with testicular and bladder tumors, both unreactive with Ost7, there was no localization of radiolabeled Ost7 in xenograft growths. When Ost7 was labeled with 131I, its accumulation into human osteogenic sarcoma could be clearly visualized by whole-body gamma-scintigraphy without computer-assisted data processing.

Animals↗

Detection of human osteosarcoma-associated antigen(s) by monoclonal antibodies.

Hybrid cell lines have been derived from a fusion between mouse myeloma cells, NS1, and spleen cells from mice immunized with freshly resected osteosarcoma cells from an untreated patient. Of the 276 hybrids obtained, five secreted antibodies which bound to osteosarcoma tissues but not to autologous skin fibroblasts. The antibodies from three of these five hybrids, OST6, OST7, and OST15, reacted with all of five osteosarcoma tissues and with one chondrosarcoma tissue but not with other malignant or benign tumors. Tests of various normal tissues were negative, except for weak binding to a subpopulation of chondrocytes in articular cartilage. The reciprocal binding inhibition test showed that OST6, OST7, and OST15 antibodies were directed against different antigenic determinants.

Animals↗

CYBEST model 3 automated cytologic screening system for uterine cancer utilizing image analysis processing.

The improvements incorporated into the Model 3 version of CYBEST (Cyto-Biological Electronic Screening System) are highlighted. Following the successful development of a software-controlled automatic shading for a video system, the new Model 3 CYBEST contains a televisions scan system with a single-step, fine-resolution scan and strobe-light illumination in place of the two-step (coarse and fine) scan of Model 2. The automatic shading control is described in detail, as is the automated focusing system, which uses a touch-sensor to achieve a near-focus level and a differential adding algorithm to obtain exact focus. Improvements in the slide magazine and slide autochanger have quadrupled the number of slides that may be loaded into the machine at one time while increasing the speed of operation. CYBEST Model 3 has achieved our goal of rapid processing, requiring less than three minutes per specimen for final assessment as compared with the six minutes per specimen of Model 2. Field tests of Model 3 are currently under way, with a large number of smears prepared by our automated cell dispersion and monolayer smearing device (CYBEST-CDMS).

Cell Nucleus↗