Search PubMed⌕ Search

Biomedical subjects

K Asakura

Publications and source records attributed to K Asakura.

At least 109 records · Page 6Linked to original sources
PubMed1996

[Manifestation of nasal allergy in ovalbumin-sensitized mice--as compared with mast cell-deficient mice, determined with an immunosuppressive agent].

We performed general and topical sensitization by ovalbumin in wild type, WBBFI6- +/+ (+/+), mice and mast cell-depleted type, WBBFI6-W/Wv (W/W)v, mice. Although both mice showed almost equal PCA liters, W/Wv mice showed a lower level of antigen-induced eosinophilia, and more significant nasal symptoms and histamine hypersensitivity than +/+ mice. Antigen-induced increased levels of histamine and IL-5 in nasal lavage fluid were noted in +/+ mice. Cyclosporin A pre-treatment inhibited the antigen-induced nasal symptoms, nasal eosinophilia and increased levels of histamine and IL-5 in nasal lavage fluid in the +/+ mice. The PCA titer was not affected by the treatment in either kind of mouse.

Animals↗
PubMed1996

[Usefulness of the newly developed transtelephonic electrocardiogram and computer-supported response system].

The "Cardiophone System" is a system designed to expand the relationship between patients and medical services using a transtelephonic electrocardiogram and computer-assisted answering system. The transtelephonic electrocardiogram, or so-called "Cardiophone", developed by Nihon Kohden, Inc., allows the patients to carry a "Cardiophone" to record electrocardiograms during paroxysmal occurrences of palpitation, chest pain, and other symptoms. The Cardiophone may function as a terminal of the host computer at the hospital, which stores the electrocardiogram and print it as soon as the computer receives the electrocardiogram over the phone. Cardiologists can examine the electrocardiogram immediately after it is printed. Cardiologists and operators are on duty 24 hours a day. Judgments based on the electrocardiogram are made by the cardiologist on duty, and stored in the computer by the operator. The patients may listen to the judgment over the phone within 30 min of sending the electrocardiogram. In the case of potentially lethal findings on the electrocardiogram, the cardiologist on duty calls the patient directly to give a medical advice. We studied 184 outpatients who were enrolled in the Cardiophone System of our hospital. The average number of transtelephonic electrocardiograms was 10 per day. Abnormal electrocardiographic changes were observed in 42 patients, and the diagnoses were as follows: paroxysmal supraventricular tachycardia in 18 patients, paroxysmal atrial fibrillation in 17, ventricular tachycardia in 3, and angina in 7. Among seven patients in whom ST changes were documented by Cardiophone, six were diagnosed as variant angina. In several patients with diagnoses already made by Holter monitoring, the Cardiophone was used to monitor the drug effects and the correlations between symptoms and arrhythmic events. We conclude that the Cardiophone System is useful for diagnosing the causes of paroxysmal cardiac symptoms in some patients and for improving home medical services.

Adolescent↗
PubMed1996

[Studies on murine model of nasal allergy].

For the purpose of making a murine model of nasal allergy, we performed the ovalbumin (OA)-sensitization on groups of BALB/c mice in four different ways. The 1st group was sensitized with OA + alum by introperitoneal myection on day 1, 5 and 21, and the 2nd group was added OA nasal drips on day 28, 34. The 3rd group was performed OA + alum nasal dripping on day 1, 5 and 21, and the 4th was a added OA nasal dripping in the same way with the 2nd group. The observed OA-induced nasal symptoms, mucosal eosinophillia and 8 days-PCA titer were remarkable in 2nd group, moreover it also showed higher histamine hypersensitivity than other groups. We concluded that mice sensitized by OA with alum are useful for research of nasal allergy, for the reason that they posses three features of nasal allergy, anti-intigen-induced nasal symptoms, eosinophils infiltration and antigen-specific PCA titer as index of IgE increasing.

Animals↗
PubMed1996

Does adenotonsillectomy affect the course of bronchial asthma and nasal allergy?

Twenty-five bronchial asthma patients who underwent adenotonsillectomy were studied for postoperative changes of respiratory symptoms, doses or frequency of medications, and required hospitalization. Postoperative evaluation proved that 22 patients (88%) improved their asthmatic symptoms, 15 patients (60%) were able to eliminate all of their medications, and 7 patients (28%) were able to eliminate some of their medication. There were no patients with aggravated conditions. Out of 17 patients with nasal allergy, only 3 patients (18%) improved their nasal symptoms. The results suggest that adenotonsillectomy might change some conditions of allergic states in children.

Adenoidectomy↗
PubMed1996

Adenotonsillar hypertrophy and skeletal morphology of children with obstructive sleep apnea syndrome.

To define the role of adenotonsillar hypertrophy and facial morphology in obstructive sleep apnea (OSA) in children we performed a cephalometric analysis of an OSA group and an age-matched control group. Adenotonsillar hypertrophy was remarkable in OSA children at every age level. Maxillary protrusion expressed by SNA was significantly smaller in the OSA group than in the control group for elderly children (5-9 years old). Mandibul protrusion expressed by SNB was significantly smaller in the OSA group even at younger ages (1-2 years). The hyoid bone was significantly lower in the OSA group than in the control group who were from 3 to 6 years. Environmental factors due to upper airway obstruction as well as genetic factors are suspected to cause abnormal facial morphology in OSA children.

Adenoids↗
PubMed1996

Antigen specific immunoglobulin production by NALT lymphocytes in rats.

In this study, we examined the antigen specific immunoglobulin (Ig) contents in nasopharyngeal lavage fluid and antigen specific Ig production by NALT lymphocytes in rats immunized by various routes. OA specific IgG SFC in NALT lymphocytes was higher than that in spleen lymphocytes in locally immunized rats, whereas the inverse relationship was noted in generally immunized rats. These OA-specific IgG SFC were remarkably increased in NALT, but not so increased in spleen following nasal booster challenge. However, the number of OA specific IgA SFC in freshly obtained lymphocytes was very low in both NALT and spleen even after topical antigen challenge. A significant increase of antigen-specific IgA and IgG levels was noted in the naso-pharyngeal lavage fluid of immunized animals, whereas these Ab levels were not changed 48 h after topical antigen challenge. OA specific IgA SFC were revealed to be increased after in vitro stimulation with lipopolysaccaride (LPS). A preliminary study showed that further increase of antigen-specific IgA as well as IgG production by NALT lymphocytes occurred in the presence of TGF-beta and IL-5.

Animals↗
PubMed1996

Profile of immunoglobulin production in adenoid and tonsil lymphocytes.

The adenoids and tonsils are thought to be essential parts of the system protecting against pathogens invading the upper respiratory tracts. We have examined IgA-spot forming cells (SFC) as well as IgG- and IgM-SFC in human adenoid and tonsil lymphocytes. The majority of SPC were revealed to be IgG type in adenoid and tonsil lymphocytes. However, when the changes in the number of SFC were examined following 6 days of incubation in the presence of LPS and Con A, an increase in IgA-SFC was noted in both adenoid and tonsillar lymphocytes, suggesting that adenoid and tonsillar lymphocytes differentiate into IgA forming cells under appropriate conditions.

Adenoids↗
PubMed1995

Oligodendrocyte-reactive O1, O4, and HNK-1 monoclonal antibodies are encoded by germline immunoglobulin genes.

Natural or physiologic autoantibodies are present normally in serum, are polyreactive, are frequently of the IgM subtype, and are encoded by unmutated germline genes. We tested whether the oligodendrocyte-reactive O1, O4, A2B5, and HNK-1 IgM kappa monoclonal antibodies are natural autoantibodies by sequencing immunoglobulin (Ig) cDNAs and comparing these with published germline sequences. O1 VH was identical with unrearranged VH segment transcript A1 and A4. O4 VH had three and HNK-1 VH had six nucleotide differences from germline VH101 in the VH coding region. The D segment of O1 was derived from germline SP2 gene family. The D segments of O4 and HNK-1 were derived from DFL16 gene family. O4 JH and HNK-1 JH were encoded by unmutated germline JH4, whereas O1 JH was encoded by germline JH1 with one silent nucleotide change. O1 and O4 light chains were identical with myeloma MOPC21 except for one silent nucleotide change. HNK-1 V kappa was identical with germline V kappa 41 except for two silent nucleotide changes. O1 J kappa, O4 J kappa and HNK J kappa were encoded by unmutated germline J kappa 2. In contrast, A2B5 VH showed seven nucleotide differences from germline V1, whereas no germline sequence encoding A2B5 V kappa was identified. O1 and O4, but not A2B5 were polyreactive against multiple antigens by direct ELISA. Therefore, O1, O4 and HNK-1 Igs are encoded by germline genes, and have the genotype and phenotype of natural autoantibodies.

Amino Acid Sequence↗
PubMed1995

kappa-opioid agonist U50488 inhibits P-type Ca2+ channels by two mechanisms.

The effects of U50488, kappa-opioid agonist on P-type Ca2+ channels, were studied. U50488 inhibited depolarization-induced Ca2+ uptake into rat brain synaptosomes, which was sensitive to omega-Agatoxin IVA (omega-AgaIVA; P-type Ca2+ channel blocker) and inhibited P-type Ca2+ channel currents recorded from rat cerebellar Purkinje neurons by the whole-cell patch clamp method. Dynorphin A also inhibited P-type Ca2+ channel currents. The inhibition by U50488 was biphasic; high affinity component (21%, IC50 = 8.9 x 10(-8) M) and low affinity component (79%, IC50 = 1.1 x 10(-5) M). At low concentrations of U50488 (10(-6) M), P-type Ca2+ channel current inhibition was attenuated by norbinartorphimine (nor-BNI), kappa-opioid antagonist, and by dialysis of cells with a pipette solution containing guanosine 5'-O-(2-thiodiphosphate) (GDP-beta S). At high concentrations of U50488 (10(-5) M), P-type Ca2+ channel current inhibition was frequency-dependent. Thus U50488-induced current inhibition is mediated by two mechanisms. Its high affinity component is produced by activation of kappa-opioid receptors, whereas the low affinity component is due to its direct action on the P-type Ca2+ channel.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗
PubMed1995

Experimental strategies to promote central nervous system remyelination in multiple sclerosis: insights gained from the Theiler's virus model system.

The destruction of central nervous system (CNS) myelin, the lipid-rich insulator surrounding axons in the mammalian brain and spinal cord, is the primary pathological finding in multiple sclerosis. Myelin loss can result in a significant clinical deficit, and was originally thought to be permanent, similar to axonal destruction. However, myelin regeneration is now an established phenomenon in both human disease and animal models of CNS demyelination. In this review, the concept of remyelination in demyelinating diseases such as multiple sclerosis is discussed and the usefulness of animal models of CNS demyelination in developing experimental strategies to promote remyelination is examined. Special emphasis is given to the Theiler's murine encephalomyelitis model, which has been the primary animal model used to investigate therapies designed specifically to stimulate myelin repair.

Animals↗
PubMed1995

[Relationship between birch pollen allergy and oral and pharyngeal hypersensitivity to fruit].

We evaluated the relationship between birch pollen allergy and oral and pharyngeal hypersensitivities to certain fruits. 1. Of 171 birch pollen CAP positive (score > or = 2) patients, twenty two (13%) were revealed to be hypersensitive to apples, eleven (6%) to be hypersensitive to peaches, both rates being higher than those found in patients with other CAP positive reactions (orchard grass pollen CAP, mugwort pollen CAP or Dermatophagoides pteronyssius CAP positive). 2. Among the birch pollen CAP positive patients, the higher the CAP score for birch pollen, the higher the prevalences of hypersensitivity to apples and peaches were found to be. 3. Of 171 birch pollen CAP positive patients, six (3.5%) were revealed to be hypersensitive to kiwi fruit. Of 253 patients with other CAP positive reactions, three (1%) were revealed to be hypersensitive to kiwi fruit.

Adolescent↗
PubMed1995

IgA nephropathy associated with hyper IgAnemia, psoriasis or pustulosis and ossification.

This is a report on two cases of IgA nephropathy associated with psoriasis vulgaris, having hyper IgAnemia (above 500 mg/dl) and ossification. Case 1 is a 47-year-old woman with a 7-year history of psoriasis vulgaris, and case 2 is a 57-year-old man with a 17-year history of this disease. IgA was 526 and 1,356 mg/dl, respectively. HLA analysis showed A2, A26 (10), Bw62 (15), Bw46, Cw3, DRw12 (5), and DRw8 in the former, and A2, A11, B13, Bw46, Cw11, DR4, and DRw8 in the latter. Renal biopsy specimens disclosed mild mesangial proliferative glomerulonephritis and moderate mesangial proliferative glomerulonephritis with predominant IgA deposition in mesangial area, respectively. A bone-scintigraphy revealed a high uptake of radioisotopes in the left shoulder, the vertebra, the sacroiliac joint, both sides of the knees and ankles, and the sterno-cost-clavicular area. An X-ray study showed ossification of the posterior longitudinal ligament (OPLL) in the former, and ankylosing spinal hyperostosis (ASH) in the latter. A review of the literature discloses three other case reports of hyper IgAnemia, IgA nephropathy, psoriasis or pustulosis, and ossification. The alertness of dermatologists, orthopedic surgeons, rheumatologists, and general practitioners will be required to attain to a more frequent diagnosis of the above combination.

Female↗
PubMed1995

[Studies on thromboxane B2 level in nasal lavage fluid after antigen challenge in patients with allergic rhinitis and guinea pig models].

Thromboxane A2 (TxA2) seems to play an important role in bronchial constriction and hypersensitivity in asthmatics. To study the role of TxA2 in allergic rhinitis, we investigated the levels of thromboxane B2 (TxB2), a stable metabolite of TxA2, in nasal lavage fluid from patients with allergic rhinitis and from actively sensitized guinea pigs after antigen challenge by radioimmunoassay (RIA). There was a significant (p < 0.05) rise in TxB2 levels soon after antigen challenge in nasal lavage fluid from both patients (36.4 +/- 7.5 pg/ml, mean +/- SE) and models (55.6 +/- 21.8 pg/ml). In some of the patients and models, there was an dual rise in TxB2 in the 10 hours after antigen challenge. There was a significant (p < 0.03) correlation between the patients whose levels of TxB2 were re-elevated and them whose nasal airway resistance showed dual rises. These results suggest that TxA2 may contribute to the nasal obstruction in later phase in allergic rhinitis.

Adult↗
PubMed1994

Partially oxygenated sickled cells: sickle-shaped red cells found in circulating blood of patients with sickle cell disease.

A previously uncharacterized type of sickled cell was found in venous blood of patients with sickle cell disease when blood was collected without exposure to air and fixed immediately with 1% glutaraldehyde solution equilibrated with 5% oxygen. These cells were either elongated, resembling irreversibly sickled cells (ISCs), or nonelongated, with a raisin-like shape. Both types assumed a normal discoidal shape upon full oxygenation. Since these cells exist only under partially oxygenated conditions, they are described as partially oxygenated sickled cells (POSCs). POSCs are morphologically distinct from partially deoxygenated sickled cells formed during deoxygenation by having rounded edges, while the latter have sharp edges. Transmission electron microscopy of POSCs revealed various amounts of misaligned Hb S polymers. Investigations in vitro demonstrated the formation of POSC-like cells by partial oxygenation of deoxygenated cells. Since POSCs contain intracellular fibers and sickle readily upon deoxygenation, they may have clinical and pathological significance.

Anemia, Sickle Cell↗
PubMed1994

Changes in nasal airway resistance and secretory response in the guinea pig after nasal challenge with capsaicin and histamine.

We studied serial changes of nasal airway resistance (NAR) and secretory response after topical stimulation with either capsaicin or histamine, since both are known to stimulate a chemosensitive sensory C-fiber ending. After topical capsaicin stimulation, a dose-related increase of NAR was noted, with a peak response occurring at 10-20 min. These NAR responses were completely abolished following systemic pretreatment with capsaicin. However, they were not affected by atropine, diphenhydramine or hexamethonium pretreatment. After topical histamine stimulation, an atropine-resistant increase of NAR was found and continued more than 120 min. The early phase of this response was significantly suppressed by the systemic pretreatment with capsaicin. A secretory response also occurred after topical capsaicin stimulation and continued for 30 min. This secretory response was almost completely blocked by atropine, hexamethonium or systemic capsaicin pretreatment and was partially suppressed by diphenhydramine pretreatment. These findings suggest that sensory C-fiber stimulation can induce both atropine-resistant vascular reflexes and atropine-sensitive secretory reflexes, and that these reflexes might play an important role during the early phase after nasal stimulation.

Administration, Intranasal↗