Search PubMed⌕ Search

Biomedical subjects

K Imagawa

Publications and source records attributed to K Imagawa.

At least 73 records · Page 4Linked to original sources
PubMed1981

Glucagon radioimmunoassay with use of antiserum to glucagon C-terminal fragment.

In this pancreatic-glucagon-specific radioimmunoassay we used C-terminal-region-specific antiserum. OAL-123, produced against a 19-29 C-terminal fragment of porcine glucagon. On measurement of pooled plasma the ranges for intra- and inter-assay coefficients of variation were 4.8-8.1% and 7.5-10.7%, respectively. The concentration of immunoreactive glucagon in plasma of healthy subjects, as measured with the OAL-123 assay system, was 87.9 (SD 23.8) ng/L. Measurement of the same plasma samples with the 30K assay system (30K being an antiserum highly specific for pancreatic glucagon) showed a comparable value, 86.2 (SD 26.3) ng/L. We followed changes in human and dog plasma immunoreactive glucagon concentrations on arginine infusion and after glucose load, using the OAL-123 and the 30K assay systems, with identical results. Combining other results of comparative immunochemical characterization of the OAL-123 and 30K assay systems, we confirmed that the antisera raised against the C-terminal fragment of glucagon can be used in radioimmunoassay of pancreatic glucagon.

Amino Acids↗
PubMed1980

Heterogeneity of plasma motilin in patients with chronic renal failure.

Plasma immunoreactive motilin (IRM) concentrations were strikingly higher in patients with chronic renal failure (CRF) than in normal subjects. IRM in azotemic plasma was heterogeneous in gel-filtration profile. The first peak eluted in the void volume of the column and the second and the third one, comprising a major portion of IRM content, came out coincidentally with insulin and authentic motilin, respectively. By contrast, no discernible amount of IRM was found in the region corresponding with the second peak in gel-filtration of the plasma from normals and very little in a patient with ileus whole plasma IRM level was elevated. The hypermotilinemia and the accumulation of this high molecular weight motilin in patients with CRF suggest that the kidney plays some role in the elimination of motilin, and further, that the clearance of the high molecular motilin is more dependent on renal function than that of authentic motilin. The present paper emphasizes the necessity for clarifying the significance of the heterogeneity of IRM in CRF.

Chromatography, Gel↗
PubMed1980

A study of the physiological role of glucagon. Passive immunization with antiserum specific for pancreatic glucagon in rats.

To investigate the physiological role of glucagon in the maintenance of euglycemia, the effect of the neutralization of glucagon by an antiserum specific for glucagon on blood glucose and C-peptide immunoreactivity (CPR) levels was studied in the basal as well as in the hyperglucagonemic states caused by hypoglycemia or an intravenous infusion of arginine in rats. The antiserum employed in this study was raised in rabbits by subcutaneous injection as a conjugate of BSA and the C-terminal fragment of glucagon. Since the antiserum was found to contain 896 ng/ml of antibody-bound glucagon, the antigen-stripped glucagon antibody was prepared. Its affinity constant and binding capacity were 2.57 x 10(10) M-1 and 147 nM, respectively. After the administration of 1 ml of the antiserum in 24-hr-fasted rats, no free immuno reactive glucagon (IRG) was detected during the experiment for 60 min. Likewise, antiserum treatment prevented a rise in the plasma IRG level following an arginine infusion and insulin-induced hypoglycemia. Plasma CPR levels tended to be lower in antiserum-treated rats than in the control in any conditions covered by the present study. However, changes in blood glucose levels the both groups were comparable. These results demonstrate that in the presence of glucagon antibodies euglycemia can be maintained with a reduced supply of insulin.

Animals↗
PubMed1980

Heterogeneity of immunoreactive motilin.

Motilin-like immunoreactivities were examined in extracts of duodena of pig, human, dog, rat, cat, rabbit and guinea pig with a combination of radioimmunoassays using three different antisera possessing distinct region-specificities. Antisera GP-1103 and R-1104 were rather C-terminal specific, but the immunological feature of GP-1103 was different from that of R-1104. In the case of antiserum GP-1103, the Glu residue in position 15 in the motilin molecule participated in antigen-antibody interaction, but not in the case of R-1104. Antiserum MBR-02 was N-terminal specific, with of the three assay systems, only a single major peak was detected in the elution profile from BioGel P-10 column of motilin-like immunoreactivity in the porcine duodenal extract, of which the elution volume corresponded to that for synthetic porcine motilin. On the other hand, the gel filtration profiles of the human and canine duodenal extracts consisted of two or three peaks of the immunoreactivity. The major peak emerged in the elution volume identical with that for synthetic porcine motilin and the other two peaks were eluted earlier. The peak which was eluted in the volume corresponding to that for BSA marker was detectable only by the assay system with N-terminal specific antiserum MBR-02. The immunoreactivity of the major peak component in the human, canine or rat extract was found to be lower than that in the porcine extract. The present data may indicate the existence of heterogeneity of motilin-like immunoreactivity and species variation of the structure of the immunoreactive motilin.

Animals↗
PubMed1979

The location of LH-RH neurons in the rat hypothalamus and their pathways to the median eminence. Experimental immunohistochemistry and radioimmunoassay.

The location of the perikarya of LH-RH neurons in the rat hypothalamus and their pathways to the median eminence were studied by immunohistochemistry and radioimmunoassay after placing stereotaxic electrolytic lesions in several parts of the hypothalamus. The principal location of the cell somata was found to be in the ventral part of the medial preoptic area; their pathways were classified into a main baso-lateral pathway and an accessory descending pathway branching off from the former. The main pathway was found to cross in the vicinity of the corresponding neuronal perikarya. The central median eminence and the dorsal and ventral walls of the tubero-infundibular sulcus of the caudal part of the median eminence are innervated mainly by the baso-lateral pathway. On the other hand, the rostral and most caudal protions of the median eminence are innervated principally by the descending pathway and have a subsidiary dual innervation. The projection of LH-RH neurons to the OVLT is believed to originate from perikarya adjacent to this circumventricular organ.

Animals↗
PubMed1979

Detection of catecholamine and luteinizing hormone-releasing hormone (LH-RH) containing nerve endings in the median eminence and the organon vasculosum laminae terminalis by fluorescence histochemistry and immunohistochemistry on the same microscopic sections.

Distribution of catecholamine (CA) and LH-RH nerve endings in the median eminence (ME) and the organon vasculosum laminae terminalis (OVLT) of the rat was investigated by application of fluorescence histochemistry and immunohistochemistry on the same sections of the tissue. In the ME, those two kinds of endings coexisted in the lateral portion of the middle part of ME, and in the wall of tuberoinfundibular sulcus, where they might be considered to have functional correlation. In the OVLT they were also distributed in fairly near distance, but they were not so closely associated as observed in the ME.

Animals↗
PubMed1979

Production of anti-glucagon sera with a C-terminal fragment of pancreatic glucagon.

The C-terminal region-sepcific anti-glucagon sera were raised in rabbits using as immunogen, and conjugate of BSA and a C-terminal fragment of pancreatic glucagon. The hapten was prepared by trypsin digestion of the glucagon, which was proved to be a 1:3 mixture of glucagon (18--29) and (19--29). Six rabbits were immunized by subcutaneous injection of an emulsion of the conjugate with complete Freund's adjuvant and five of the rabbits produced antibodies to the glucagon (GC-1, GC-2, GC-3, GC-5 and GC-6). For comparison, rabbit antisera were also produced against glucagon polymer (GA-10) and syrupy glucagon fibrils (PGA-2). All these antisera as well as the pancreatic glucagon-specific antiserum 30 K were characterized with dog gut-extract (gut-GLI) and glucagon-related peptide fragments in the radioimmunoassay systems. The assay systems utilized 125 I-monosubstituted pancreatic glucagon as tracer and human mono-component glucagon as standard. All sera of the GC-series crossreacted with the dog gut-extract very weakly and antisera GC-5 and GC-6 exhibited the lowest crossreactivities with the extract, which were shown to be as low as that of 30k. Characterization of the antiserum GC-5 with purified glucagon related fragments indicated that the major antigenic determinant located exactly in the C-terminal region of glucagon. The present results clearly showed high efficiency of the use of the glucagon C-terminal fragment as hepatenic immunogen in obtaining the C-terminal region-specific, i.e., pancreatic glucagon-specific antisera.

Animals↗
PubMed1978

Distribution of LH-RH nerve endings in the median eminence of proestrus female rats: fluorescence and peroxidase anti-peroxidase (PAP) immunohistochemistry.

The morphological distribution of the nerve terminals containing LH-RH in the hypothalamus especially in the median eminence of the proestrus female rat was demonstrated by immunohistochemistry, using FITC and peroxidase antibody. The terminals containing LH-RH were classified into four groups on the topographic relationship. LH-RH nerve processes terminated mainly in the infurdibular radix within an elliptical zone surrounding the bases of the infundibular recessus. The heaviest concentration of LH-RH terminals immunohistochemically demonstrated lay on each side of the region extending from the dorsal part of tuberoinfundibular sulcus to the lateral part of the external layer of the superior labium of the infundibulum. We were unable to detect any neuronal soma with the immunoreactivity to LH-RH in the hypothalamic gray matter. The distributional patterns of LH-RH, GH-RIH and monoamine in the median eminence as well as their relationships were briefly discussed.

Animals↗
PubMed1978

[Immunological examination in patients with brain tumor and the usefulness of PHA skin test (author's transl)].

The usefulness of in vivo skin test reaction to phytohemagglutinin to assess cell-mediated immunity was investigated in 109 subjects, including 37 normal controls, 35 patients without brain tumor and 37 patients with brain tumor. Intradermal injection at forearm of 10 microgram of Bacto-phytohemagglutinin-P (PHA-P) produced an erythema within 24 hours. Upon PHA skin reaction the mean diameter of erythema was 25.3 mm with the normal in the control and 18.6 mm with other diseases than brain tumor, while it was 13.0 mm with brain tumor. Furthermore when mean diameter of those with longer than 15.0 mm are classified as positive in the PHA skin test, the normal in the control revealed 89.2% positive and the patients with brain tumor indicated only 37.8% positive. A positive reaction was observed in 10 (77.0%) of 13 benign brain tumor and 5 (26.3%) of 19 malignant brain tumor. A correlation was found between in vivo and in vitro responses to PHA, and between PHA and PPD skin reaction. In repeated PHA skin test at intervals of about one month, the skin reaction to PHA of patients with brain tumor varied depending on the clinical states. Other advantages of this test are no presensitization and it can be used repeatedly. The PHA skin test is a useful and simple screening test for cellular immune function of patients with brain tumor and as a simple method applicable clinically indicating accurate immuno-reactivity the PHA skin tests have been carried out during the course of treatment with an interval of about one month repeatedly.

Adenoma↗
PubMed1977

[A case of enchondroma of the skull base--a manifestation of generalized chondromatosis (author's transl)].

Cartilaginous tumors arising from the skull or intracranial structures are infrequently seen. There have been 112 such cases reported. They are most commonly found in the middle fossa and the parasellar region. They arise from cartilaginous rests in the base of the skull, particularly around the basal synchondroses. Occasional cases of intracranial growths also show lesions in peripheral bones. The authors have encountered a case in which chondroma was a manifestation of generalized chondromatosis. The patient was a 25-year-old male, who complained of diplopia in May 1975. He noted ptosis in his left eyelid which gradually progressed over a 2 months period to complete ptosis. When he was admitted in July 1975 to Nagoya National Hospital, the neurologic signs revealed a palsy of the IIIrd cranial nerve on the left side. The patient has been suffering from generalized enchondromatosis during a period of 20 years. Roentgenograms revealed extensive areas of bone destruction and pathological calcification of the phalanx, ribs, hip bone, femur, tibia, ulna and radius. Roentgenograms of the skull revealed calcification on the left middle fossa. After a left carotid angiography, an osteoplastic craniotomy was performed on August 5, 1975. The tumor was located in the extradural space of the middle cranial fossa. After incision of the capsule, gelatinous semisolid tissue was removed piecemeal. Its total removal proved to be impossible. Histological examination of this tumor revealed enchondroma.

Adult↗
PubMed1977

Intracranial chondroma.

Two cases of intracranial chondroma are reported. In both cases, the tumor was located extradurally in the middle cranial fossa. The tumors were removed piecemeal, but total removal proved to be impossible.

Adult↗
PubMed1976

[A clinicopathological study of the cranial "histiocytosis X" (AUTHOR'S TRANSL)].

A clinicopathological study of 13 cases of cranial histiocytosis X was discussed. The patients were mostly infants, and those under 15 years of age numbered eight. Hematological, blood chemistrical, and other laboratorical prodedures have produced no direct diagnostic value. Radiographically, this lesion in skull appeared to be a lytic defect in all cases. Histologically, they were unified by a localized or generalized histiocytic proliferation. Eosinophilic cells were also found throughout the lesional tissue. There were some slight histological variations from case to case, for instance, in the degree of infiltration by eosinophilic cells, and the number of the histiocytic cells. However, the basic histological pattern remained the same in all cases. The lesion may already have extended into the neighboring osseous tissues. Sections of the neighboring osseous tissues showed the intertrabecular spaces to be infiltrated by the same type of lesion. The patient related trauma to the onset of symptoms in 6 cases, but it is true that we know nothing of the etiology of this lesion. The treatment of choice is the adequate surgical extirpation. It seems fair to conclude that wide surgical excision with postoperative irradiation or with chemotherapy may be expected to affect a clinical cure.

Adult↗