Biomedical subjects

Y Yamamura

Publications and source records attributed to Y Yamamura.

At least 163 records · Page 9Linked to original sources

PubMed1996

The prognostic value of preoperative serum levels of CEA and CA19-9 in patients with gastric cancer.

OBJECTIVES: The clinical significance of preoperative serum levels of tumor markers CEA and CA19-9 was evaluated in gastric cancer patients. METHODS: Serum levels of CEA and CA19-9 were measured in 663 patients with gastric cancer who underwent laparotomies over a recent 4-yr period (1990-1993). The correlations between the serum levels of tumor markers and several clinicopathological factors were evaluated by univariate analysis. The significance of the tumor markers as prognostic factors was assessed by multivariate analysis. RESULTS: The positivity rates of CEA and CA19-9 were 16.6% and 16.0%, respectively. The positivity of CEA correlated well with the sex of the patients, hepatic, peritoneal, and nodal metastases and the depths of tumors, but it correlated weakly with a tumor's histological type. The positivity of CA19-9 correlated well with various forms of metastases, depths, and tumor size. A significant in prognosis was observed between patients positive and negative for CA19-9 among those undergoing R0 resection. Multivariate analysis also revealed that serum CA19-9 was better than CEA as a prognostic factor. CONCLUSIONS: CA19-9 in the preoperative sera is a good prognostic factor in gastric cancer patients, although tumor markers continue to have only limited diagnostic usefulness.

Biomarkers, Tumor↗

PubMed1996

[Quality control of surgery in multicenter study--interinstitutional and individual differences].

UNLABELLED: In a prospective randomized controlled trial (PRCT) of adjuvant chemotherapy for gastric cancer patients participated by 6 cancer center hospitals, inter-institutional and inter-individual differences about several factors related to the surgery and remote survivals were analyzed. From 1988 to 1992, 1,049 evaluable patients were enrolled and stratified to 6 groups according to the grade of the serosal invasion and curability, and analyzed statistically. RESULTS: 1) There were no inter-institutional differences about postoperative survival rate, but there were slight differences about patient's background factors and entry policy of each institution. 2) There were no inter-institutional differences about several factors related to the surgery such as operative time, bleeding volume during operation, and the length of the administration periods. 3) There were no inter-individual differences about the length of the administration periods, but there were a little differences about operative time and the volume of hemorrhage. When the PRCT of adjuvant chemotherapy of which the end point is survival would be designed, no inter-institutional differences about remote survival and surgical operation in each institution should be confirmed before starting the trial.

Chemotherapy, Adjuvant↗

PubMed1996

Water channel protein subtype suggests the origin of renal cell carcinoma.

PURPOSE: Several subtypes of water selective channel protein have been cloned. In normal kidneys, CHIP-28 (channel forming integral protein of 28 kd) is expressed solely in the proximal tubules and descending thin limbs, and aquaporin-CD (AQP-CD) expression is restricted to collecting ducts. We assessed expression of these 2 distinct types of water channels in renal cancer tissues. MATERIALS AND METHODS: Expression of CHIP-28 and AQP-CD was examined in 12 samples of primary renal cell carcinoma by Northern blot, reverse transcriptase-polymerase chain reaction and immunohistochemistry. We also evaluated expression of these 2 molecules immunohistochemically in 4 samples of Bellini duct tumor, which has been thought to arise from renal collecting ducts. RESULTS: Expression of CHIP-28 was detected in all of the samples of primary renal cell carcinoma, whereas none of them expressed AQP-CD. None of 4 samples of Bellini duct tumor expressed CHIP-28, although expression of AQP-CD was recognized in 2. CONCLUSIONS: Our current observation confirms the idea of the proximal or descending tubule origin of renal cell carcinoma.

Aged↗

PubMed1996

[Prolonged QTc intervals in Parkinson's disease--relation to sudden death and autonomic dysfunction].

Sudden death has been reported in Parkinson's disease (PD), but the cause of death has not been fully clarified. A prolonged QT interval on the electrocardiogram (ECG) of patients without cardiac dysfunction is an independent risk factor for sudden death regardless of etiology. QT prolongation is believed to be related to cardiac autonomic dysfunction. We suspected that QTc intervals, as well as QT intervals, might be related to the clinical characteristics of PD and to the function of the autonomic nervous system in PD and also postulated a relationship between QTc prolongation and sudden death in PD. We investigated the QTc intervals on the ECGs of 48 PD patients (20 males 28 females) aged 64.5 +/- 9.4 years and 44 controls aged 60.0 +/- 8.2 years, and excluded patients with heart disease. QTc intervals were determined by using ECG-8210, ECAPS12 (Nihon-Kohden). The autonomic nervous system was evaluated by measuring CVR-R and performing orthostatic tests. Since the autonomic nervous system is considered to play an important role in the mechanism of diurnal blood pressure variation (DBPV), we assessed DBPV in 19 PD patients by determining blood pressure automatically every 30 minutes for 24 hours with an ambulatory blood pressure monitor (90202, Space Lab). QTc intervals were significantly longer in the PD patients (412 +/- 26 msec) than in the controls (401 +/- 14 msec) (p < 0.02, t-test). QTc prolongation was significantly correlated with severity according to Hoehn and Yahr stage (r = 0.509, p < 0.001), orthostatic hypotension, and decreased CVR-R ratio but not with duration of PD or treatment. The incidence of QTc prolongation was higher in the PD patients with non-dipper type DBPV than in those with the dipper type. Two of the PD patients died suddenly. Their QTc intervals a year before their death were 451 msec and 470 msec, respectively, suggesting that cardiac dysautonomia may have been involved in the cause of their death. These findings suggest that cardiac autonomic dysfunction is related to the severity of PD, and that it may predispose such patients to cardiac disorders including sudden cardiac death.

Adult↗

PubMed1996

[Detection of bone metastasis by serial measurement of C-terminal telopeptide of type I collagen in patients with malignancy].

Measurements of biochemical markers specific to bone resorption are known to be useful in evaluation of skeletal metastasis. However, most of previous studies were performed cross-sectionally and sensitivity for detection of early bone metastasis was not satisfactory. Since basal levels of bone markers differ significantly individually, longitudinal studies would be preferable to evaluate small metabolic changes such as in early skeletal metastasis. Thus, we performed serial measurements of serum c-terminal telopeptide of type I collagen (ICTP), a bone resorption marker, in patients with malignancy and evaluated its clinical significances for detection of bone metastasis, comparing with measurements of propeptide of type I procollagen (PICP) and tumor markers. In total, 43 patients (41 of them are breast cancer), serial serum samples were obtained during 0.5 to 2.4 years (mean 1.4 years). In all of nine patients, who developed bone metastasis, serum ICTP level increased, and by successful treatment to the metastatic lesions, ICTP level decreased, while in some cases, tumor markers remained to be elevated. PICP was less sensitive and specific for detection of bone metastasis. Thus, serial measurement of ICTP is suggested to be useful for detection and evaluation of therapeutic responses in patients with bone metastasis.

Biomarkers, Tumor↗

PubMed1996

Functional characterization of vasopressin V1 and V2 receptors in the rabbit renal cortical collecting duct.

Recently we clarified the mechanism in which arginine-vasopressin (AVP) applied from the luminal side inhibits the basolateral Cl- conductance, which is stimulated by basolateral AVP. However, to prove that these vasopressin phenomena are expressed via receptor mediated actions, we examined the effect of specific V1 and V2 receptor antagonists, OPC-21268 and OPC-31260, respectively, on the electrical response to vasopressin in the rabbit CCD perfused in vitro. In the presence of the V2-antagonist, basolateral AVP caused only the activation of luminal Na+ conductance, indicating a V1 action. In the presence of the V1 antagonist, basolateral AVP caused the same biphasic responses in electrical parameters as cyclic AMP, representing a pure V2 action. On the other hand, a rise in cell Ca2+ in response to AVP was completely abolished in the presence of the V1-antagonist, but not by the V2-antagonist in the bath. These data confirm our earlier findings that rabbit CCD possesses both V1 and V2 receptors in the basolateral membrane. We conclude that electrical responses to AVP in the rabbit CCD are a complex of V1 and V2 receptor-mediated actions.

Animals↗

PubMed1996

Three-dimensional bone scintigraphy using volume-rendering technique and SPECT.

UNLABELLED: Three-dimensional bone scintigraphic images were made and their usefulness and limitations discussed. METHODS: After usual bone scan procedures, single-photon emission computed tomography (SPECT) data were taken and reconstructed into three-dimensional images. Volume rendering methods were used. RESULTS: Three cases of three-dimensional bone scintigraphy were obtained; one of a normal patient, one of a case of transplanted kidney and incomplete fracture of the left femoral head, and one of a case of degenerative joint disease (DJD) on the left temporomandibular joint (TMJ). The three-dimensional structure of the skeletal system was depicted more clearly by the three-dimensional images than by a conventional bone scan. CONCLUSION: Three-dimensional bone scintigraphs were thought to provide additional information for better understanding of the nature of bone lesions. Some technical improvements including automated threshold level determination and feature extraction for detecting abnormal high uptake are required before routine use can be envisaged.

Adult↗

PubMed1996

Visualization of routes of lymphatic drainage of the gallbladder with a carbon particle suspension.

BACKGROUND: Although carcinoma of the gallbladder frequently spreads lymphatically, few reports exist about the evaluation of routes of lymphatic drainage of the gallbladder by vital staining. The purpose of this study was to visualize drainage routes and the extent of lymphatic flow from the gallbladder by using vital staining with a carbon particle suspension (CH40). STUDY DESIGN: In 20 patients, 0.3 to 0.5 mL of carbon particle suspension was injected into first station nodes for the gallbladder, the cystic node or pericholedochal node, intraoperatively. After a Kocher maneuver was performed, lymph nodes and lymphatic vessels blackened by the stain were visualized macroscopically. RESULTS: Lymphatic pathways from the gallbladder were classified into three routes: right, left, and hilar. The right route, which ran along the common bile duct to the superior retropancreaticoduodenal node or the retroportal node and reached the para-aortic nodes, was stained in 95 percent of patients. The left route, which traveled toward lymph nodes medial to the hepatoduodenal ligament through the posterior aspect of the head of the pancreas, was stained in less than 50 percent of patients. Among lymph nodes along the left route, the posterior common hepatic node was most frequently stained (45 percent). The hilar route, which ascended toward the hepatic hilus, was stained in 20 percent of patients. CONCLUSIONS: These data demonstrate that the right route is a main pathway of lymphatic drainage from the gallbladder, while the left and hilar routes are branch lines. The para-aortic nodes, regarded as final regional nodes for the gallbladder, should be removed during radical surgery for advanced carcinoma of the gallbladder. Drainage along the hilar route may cause metastasis to the liver.

Carbon↗

PubMed1996

[Coagulation and fibrinolytic parameters as predictors for small-vessel disease revealed by magnetic resonance imaging of the brain].

We correlated coagulation and fibrinolytic parameters with small-vessel disease revealed by magnetic resonance imaging (MRI) of the brain. One hundred and eleven patients with asymptomatic or symptomatic cerebral infarction were randomly selected for the study; 57 males and 54 females with an average age of 66.6 +/- 9.6, age range 40 to 85, years old. Among them, 76 patients had a history of symptomatic cerebral infarction; 38 patients hypertension; and 24 patients diabetes mellitus. Patients with large cortical infarction, cerebral hemorrhage, demyelinating disease or mass lesions were excluded from the present study. The MRI scans were reviewed for areas with increased signal intensity on T2-weighted images. The small infarction was defined as a lesion less than 10mm in diameter. The activity of von Willebrand factor (vWF) correlated significantly with the grade of caps at the anterior and posterior horns of the lateral ventricle, and the number of small infarctions in the subcortical white matter and basal ganglia, suggesting vWF could be a predictor for these small-vessel disease. The grade of caps at posterior horn of the lateral ventricle and the number of small infarctions in the subcortical white matter were associated significantly with the concentration of plasma fibrinogen and reversely with the activity of antithrombin III, an inhibitory factor in coagulation system. These results indicate that hypercoagulable state may causatively relate with small-vessel disease in the territory of medullary artery branching from cortical artery. On the contrary, these coagulation parameters did not correlate significantly with small ischemic lesions in the territory of perforating artery. No correlation was observed between the level of marker proteins for platelet activation and the degree of small-vessel disease, indicating the activation of platelet could not associate with the etiology of small-vessel disease.

Adult↗

PubMed1996

Surgical treatment of Borrmann type IV gastric carcinoma: relevance of lymphadenectomy in improving survival.

BACKGROUND: Borrmann type IV gastric carcinoma carries a poor prognosis, even if curatively resected. The benefit of a lymphadenectomy is unknown. STUDY DESIGN: A retrospective study was designed to evaluate whether improvements have been made in the treatment of type IV gastric carcinoma over the past decade. The 345 patients with type IV carcinoma who underwent laparotomy within a recent 16-year period were split into two groups: one group of patients who underwent laparotomy between 1977 and 1985, and the other between 1986 and 1992. Survival data were compared between these two groups and prognostic factors for type IV gastric carcinoma were assessed by multivariate analysis. RESULTS: A significant difference in survival was observed between the groups, both of which underwent curative resection, despite a lack of difference in background factors. The improvement was more prominent among patients with nodal metastases and insignificant among patients without nodal metastases. Multivariate analysis identified nodal metastasis as a major independent prognostic factor. CONCLUSIONS: An improvement in outcome was presumably achieved through extended lymphadenectomy. However, the survival rate remains unsatisfactory, and further advances in the treatment of this disease are needed.

Adenocarcinoma↗

PubMed1996

[Autosomal recessive early-onset parkinsonism with diurnal fluctuation (AR-EPDF)--clinical characteristics].

Among heterogeneous diseases manifested by parkinsonism beginning early in life, there is a disease presenting with marked diurnal fluctuation of symptoms, called autosomal recessive early-onset parkinsonism with diurnal fluctuation (AR-EPDF). To identify the characteristics of this condition as a disease entity, we examined the clinical manifestations of AR-EPDF patients (Group I, n = 42) in comparison with those of early-onset parkinsonism patients without diurnal fluctuation (Group II, n = 34). Family history suggesting autosomal recessive inheritance was noted in 85.7% of Group I patients and 17.6% of Group II. The male-to-female ratio was 1: 1.8 in Group I, and 1:0.89 in Group II. Age at onset showed a standard distribution with an average of 25.6 years (SD: +/- 7.7) in Group I and an average of 32.7 with an increasing pattern toward 40 years in Group II. The initial symptom was dystonic gait disturbance in 42.9% of Group I and 5.9% of Group II, parkinsonian gait in 19.9% of Group I and 2.9% of Group II, and tremor in 28.6% of Group I and 41.2% of Group II. The main clinical feature was parkinsonism in both groups. Diurnal fluctuation of parkinsonism was remarkable in all but one (97.6%) of Group I, while it was not observed in Group II. Dystonic postures were noted in 79.4% of Group I and in 37.1% of Group II; hyperactive tendon reflexes in 74.3% of Group I patients and in 20% of Group II. Autonomic symptoms were mild in both groups. None of the Group I patients had dementia while two of Group II did. Levodopa was markedly effective in both groups. Dopa-induced dyskinesia was observed in 96.8% of Group I and in 61.8% of Group II. As for progression of the disease, the Hoehn-Yahr stage of patients on medication was evaluated as 2.2 +/- 0.7 (mean +/- SD) in Group I and 3.1 +/- 1.1 in Group II for a period of 10 to 20 years of onset, 2.5 +/- 0.8 in Group I and 3.3 +/- 0.5 in Group II for 20 to 30 years, and 3.2 +/- 0.9 in Group I and 4.3 +/- 0.6 in Group II after 30 years. There were significant differences between the two groups in the frequency of positive family history, in the mean and distribution of age at onset, in the incidence of dystonic gait as the initial symptom, and in the incidences and medians of the variables including dystonia, hyperreflexia and dopa-induced dyskinesia, as well as in the progression of the disease. Thus, we have successfully characterized the clinical features of AR-EPDF and demonstrated that diurnal fluctuation is a cardinal symptom of this disease. Reported pathologic studies on AR-EPDF showed the nigral lesion characterized by non-Lewy body type degeneration and the occurrence of melanin-poor neurons. These pathologic findings as well as the clinical manifestations differentiate AR-EPDF from Parkinson's disease and from autosomal-dominant familial parkinsonism. Low melanin-content of the nigral neurons is also a striking feature of hereditary progressive dystonia with diurnal fluctuation, in which unlike AR-EPDF there is no neuronal loss in the substantia nigra.

Adult↗

PubMed1995

Increased nitric oxide biosynthesis in leukotoxin,9,10-epoxy-12-octadecenoate injured lung.

We measured effluent nitric oxide levels using a chemiluminescence method from leukotoxin (Lx, a linoleate epoxide) injured isolated rat lungs perfused with physiological salt solution. Nitric oxide production from Lx-injured lung promptly increased and lasted for 20 min. Pretreatment with NG-monomethyl-L-arginine (LNMMA) significantly suppressed Lx-induced production of nitric oxide. Effluent from control lungs showed trace levels of nitric oxide. The wet to dry lung weight (WLW/DLW) after termination of the experiments was significantly elevated in Lx-treated lungs compared with that of LNMMA pretreated lungs or control lungs. There was a correlation between nitric oxide levels (at 10 min) and lung edema (WLW/DLW). Thus, nitric oxide plays a role in the pathogenesis of Lx-induced lung injury.

Animals↗

PubMed1995

The relationship between pharmacokinetic behaviour of glycyrrhizin and hepatic function in patients with acute hepatitis and liver cirrhosis.

The pharmacokinetic behavior of glycyrrhizin in four patients with acute hepatitis (hepatitis group) and six patients with liver cirrhosis (cirrhosis group) receiving chronically an IV administration of a 120 mg dose once a day or once every other day of glycyrrhizin was investigated. The plasma concentration of glycyrrhizin declined monoexponentially in both groups. The elimination half-life (t1/2) for glycyrrhizin in the hepatitis and cirrhosis groups varied significantly in the range of 2.7-7.6 h and 6.2-40.1 h, and the total body clearance (CLtot) in the range of 2.8-23.2 mL h-1 kg-1 and 1.4-12.9 mL h-1 kg-1, respectively. The t1/2 for glycyrrhizin in the hepatitis and the cirrhosis groups was about twice and eight times that in normal subjects, respectively, as reported previously, and CLtot values were about 0.7 and 0.23 times that in normal subjects, respectively. There was significant correlation between the CLtot and hepatic function (aspartate aminotransferase and alanine aminotransferase in serum) in both patient groups. With improvement of the liver function, the CLtot for glycyrrhizin increased from 2.8 ml h-1 kg-1 to 11.4 mL h-1 kg-1, and the t1/2 shortened from 7.6 h to 3.4 h. These findings indicated that the variation of pharmacokinetic behaviour of glycyrrhizin in both groups was closely related to the extent of the liver function.

Adult↗

PubMed1995

Incidence, diagnosis and significance of multiple gastric cancer.

Of 2790 patients with gastric cancer undergoing surgery between January 1978 and December 1993, 160 (with 356 neoplastic lesions) had synchronous multiple cancer. Of these lesions 271 (76 percent) were early cancers. Only 85 (53 percent) of the 160 patients were diagnosed before operation as having multiple cancer; 69 further patients (43 percent) were diagnosed during the course of the operation. Small flat (IIb) and depressed (IIc) type lesions had a propensity to be missed before operation. The incidence of multiple cancer was relatively low, indicating that several microscopic lesions might have been overlooked in this series. There has, however, only been one patient (1 percent) with subsequent cancer of the gastric remnant of 126 with multiple cancer and postoperative gastric remnants over the past 16 years. This might be because of co-resection of unrecognized lesions by distal gastrectomy in 68 percent of the patients. Alternatively some microscopic cancers might not invariably be destined to grow into clinically significant lesions over 10 or more years.

Female↗

PubMed1995

Randomized study with mitomycin C + 5-fluorouracil+cytosine arabinoside (MFC)+5-fluorouracil, MFC+tegafur and uracil (UFT), and MF+UFT in advanced gastric cancer: interinstitutional differences in a multicenter study in Japan.

In a phase III randomized trial of adjuvant chemotherapy for gastric cancer, interinstitutional differences were analyzed. A trial of three regimens: mitomycin C, 5-fluorouracil(5-FU) and CA (MFC) + continuous oral 5-FU (Group C); MFC + continuous oral UFT(tegafur and uracil) (Group B); and MF + UFT (Group C) after operation was conducted in 466 patients with gastric cancer (stage II and III) at four hospitals in Japan (CIH, CAD, ACC and NCC). Patients were stratified by the institution, stage, and tumor size (8 cm ><). The 5-year survival rates were in the order of Group A (79.0%) > B (70.0%) > C (61.0%) (P = 0.1228) in total, A (95.0%) > B (80.0%) > C (58.0%) (P < 0.05) at CAD (82 patients), A > C > B at CIH (215), C > A > B at ACC (95), and B > A > C at NCC (78). The survival rate of patients with S2(serosal exposure), 8 cm < and N0-1 cancer was higher at CIH than at the other institutions. The interinstitutional differences in patient characteristics and surgical technique were more powerful than the differences among the three groups.

Administration, Oral↗

PubMed1995

Low intensity areas observed on T2-weighted magnetic resonance imaging of the cerebral cortex in various neurological diseases.

The cerebral cortex of patients with Alzheimer's disease (AD) or amyotrophic lateral sclerosis (ALS) may show low signal intensity on T2-weighted magnetic resonance images (MRI). Since these low intensity areas (LIA) are also often observed in aged patients with other diseases, we suspected that they might be a non-specific finding. We conducted a retrospective study of LIA in 139 patients with various diseases of the central and peripheral nervous systems, and evaluated their relationship to age and other MRI findings. Brain atrophy, ventricular dilatation, white matter lesions, and LIA were visually evaluated on axial images of the spin echo sequences obtained with a 1.5 tesla (T) system. We found that LIA appeared after age 50 and became more common with advancing age. Their presence correlated with brain atrophy and white matter lesions. They were most frequent in the motor cortex, followed by the occipital and sensory cortices. Their incidence in the motor cortex was significantly higher in patients with central nervous system diseases than in those with peripheral neuropathy. We conclude that LIA are common in old patients with various neurological diseases and suggest that the deposition of iron in the cerebral cortices causes their development.

Adolescent↗

PubMed1995

Adoptive immunotherapy of poorly immunogenic tumors with in vitro sensitized cells generated by intratumoral administration of biological response modifiers.

We investigated the efficacy of intratumoral administration of biological response modifiers (BRM) in induction of in vitro sensitized (IVS) cells for adoptive immunotherapy of the poorly immunogenic MCA 102 sarcoma and B16-BL6(BL6) melanoma. We used the bacterial immunoadjuvant Nocardia rubra cell wall skeleton (N-CWS), and a streptococcal preparation, OK-432, for MCA 102 and BL6, respectively. After C57BL/6(B6) mice were inoculated subcutaneously (s.c.) with viable MCA 102 or BL6 tumor cells in the foot-pad, mice were injected intratumorally (i.t.) with N-CWS ranging from 10 to 400 micrograms or OK-432 ranging from 1 to 100 micrograms. Draining popliteal lymph nodes (LN) were harvested 7 days after i.t. administration of BRM, and LN cells were cultured with irradiated tumor cells in the presence of IL-2 for 11 days. These IVS cells (7.5 x 10(6) or 2 x 10(6)) were transferred intravenously (i.v.) to B6 mice with 4 day pulmonary metastases established by i.v. injection of viable MCA 102 cells (1 x 10(6)) or viable BL6 cells (3 x 10(5)). The mice were also received intraperitoneally 4 x 10(4) IU/day of IL-2 for 4 days after adoptive transfer. The transfer of IVS cells from mice immunized by i.t. injection of 100 micrograms of N-CWS 1 week after inoculation of tumor cells significantly reduced MCA 102 pulmonary metastases, compared with control IVS cells without administration of N-CWS. Moreover, the transfer of IVS cells from mice immunized by i.t. injection of 10 micrograms of OK-432 3 days after inoculation of tumor cells significantly reduced BL6 pulmonary metastases compared with control IVS cells without administration of OK-432. The administration of N-CWS resulted in no enhancement of in vitro cytotoxicity. Although the administration of 10 micrograms of OK-432 augmented in vitro cytotoxicity of IVS cells against BL6, cytotoxic activity was lower than that of IVS cells immunized with N-CWS. The major phenotype was CD8+ cells in IVS cells immunized with N-CWS or OK-432. These results suggest that i.t. administration of N-CWS and OK-432 facilitates the production of sensitized T-cells, and this administration route of BRM may be useful in the adoptive immunotherapy of human cancer.

Adjuvants, Immunologic↗

PubMed1995

A novel proteinase, glucagon-degrading enzyme, secreted by a human pancreatic cancer cell line, HPC-YO.

Sixty-four kinds of cell lines were examined as to their ability to degrade glucagon using conditioned-media obtained from their protein-free cultures. Two human tumor cell lines were shown to produce this activity, and the cell line, HPC-YO, established from a human pancreatic carcinoma was shown to produce the highest level of activity. The glucagon-degrading enzyme (GDE) was purified from HPC-YO conditioned-medium by a combination of ion-exchange, gel filtration, and hydroxylapatite column chromatographies. The purified GDE also degraded vasoactive intestinal polypeptide (VIP) and secretin, however, it did not cleave EGF, gastrin, insulin, somatostatin, substance P, neurotensin, or growth hormone. The molecular weight of GDE is 83,000, as determined on SDS-polyacrylamide gel electrophoresis. The N-terminal amino acid sequence of GDE was blocked, and the five partial amino acid sequences obtained on lysyl-endopeptidase digestion were determined to be N-L-T-E-E-Y-D-V-S-D-G-E-I-E-L-L-Y-E-K, V-E-T-Y-Y-D-L-L-F-E-K, L-Y-W-F-L-D-E-A-K, S-N-S-T-S-Y-V-K, and Y-Y-A-S-T-S-Y-D-D-T-Y-K. The same or homologous amino acid sequences have not been found in known proteins, demonstrating that GDE is a novel peptidase that degrades the secretin family: glucagon, VIP, and secretin.

Amino Acid Sequence↗