A peptide with unique receptor specificity: stimulation of phosphoinositide hydrolysis and induction of superoxide generation in human neutrophils

Previously, we identified peptides that stimulate phosphoinositide hydrolysis in several leukocyte cell lines from mixtures of random hexapeptide sequences. Moreover, the peptides activate phospholipase C via a pertussis toxin-sensitive G protein-coupled receptor. We now investigate the structure-activity relationship of the peptides with the goal of improving the activity of the peptides, as well as the biologic function of the peptides. Substitution of the L-methionine at the C terminus of peptides with D-methionine markedly increased the effectiveness of the peptides. The half-maximal effective concentrations of MKYMPm-NH2 and WKYMVm-NH2 for stimulation of phosphoinositide hydrolysis in U266 cells were 30 and 0.5 nM, respectively. By BIAcore analysis we confirmed the existence of a receptor for WKYMVm-NH2. Furthermore, the intracellular calcium concentration increase induced by WKYMVm-NH2 was not inhibited by several chemoattractants (FMLP, IL-8, platelet-activating factor, C5a, granulocyte-macrophage CSF, and granulocyte CSF) suggests that WKYMVm-NH2 has a unique cell surface receptor on leukocytes. WKYMVm-NH2 stimulated the phosphoinositide hydrolysis in U937, HL60, and U266 cells, as well as in human neutrophils. Moreover, WKYMVm-NH2 is more effective than FMLP in the production of superoxide in human neutrophils. The data suggest that WKYMVm-NH2 may have the ability to activate the microbicidal functions of human neutrophils.

Identification of the peptides that inhibit the stimulation of thyrotropin receptor by Graves' immunoglobulin G from peptide libraries

Graves' disease is characterized by the overproduction of thyroid hormones due to the persistent stimulation of TSH receptor by autoantibodies. To determine the epitopes recognized by the autoantibodies, an enzyme-linked immunosorbent assay was developed that uses the human TSH receptor extracellular domain attached to plastic wells. The total IgG from some of the Graves' patients interacted with the bound TSH receptor (TSHR) at a significantly higher level than that in normal individuals. The IgG preparation that showed the highest binding activity was used for the identification of peptide sequences that prevent binding of Graves' IgG to TSHR from positional scanning synthetic peptide combinatorial libraries. A hexapeptide mixture, X1X2FDDA (X1 is a mixture of E, M, and Y; X2 is a mixture of E, H, and T), was found to be effective for inhibiting the binding of Graves' IgG to the TSHR. Further fractionation of X1X2FDDA showed that the following three sequences were highly effective: EEFDDA, ETFDDA, and EHFDDA. The second position of the three peptides did not appear to be important. The peptides also inhibited the cAMP synthesis induced by IgG of four of eight patients with Graves' disease tested. The synthesis of cAMP by TSH was also inhibited by the peptides to some extent. The peptide sequences most likely mimic a part of the conformational epitopes recognized by at least one class of Graves' IgG.

Studies on bone markers and bone mineral density in patients with chronic renal failure

Renal osteodystrophy has become a frequent complication in patients with chronic renal failure (CRF), and various histologic forms such as high turnover, low turnover and mixed bone disease have been demonstrated. The only reliable method for distinguishing patients with high turnover from those with low turnover bone disease is bone histomorphometric study, but its clinical utility is restricted. Because of its invasive nature, efforts have been made to predict indirectly the type and severity of this metabolic bone disease by serum assays. In this cross-sectional study, we measured total and regional (head, arms, trunk, ribs, legs, spine and pelvis) bone mineral densities (BMD) by dual X-ray absorptiometry (DXA) in patients with variable degrees of CRF and correlated them with various bone markers. Decreased BMDs were detected in various skeletal sites (trunk and pelvis) in the patients' group. Total BMD Z score was lower in predialysis CRF patients than in the control subjects. Decreased BMD Z scores on weight-bearing bone were pronounced at L1 lumbar vertebra, femur trochanter, femur neck and Ward's triangle. Positive linear correlations were found between creatinine clearance and trunk, ribs, pelvis, and spine BMDs. There were inverse linear correlations between total BMD and total BMD Z score and alkaline phosphatase (AP), urine deoxypyridinoline (U-DPD) in the patients' group. There were no correlations between regional and total BMD, total BMD Z score and serum calcium, ionized calcium, and serum phosphate. There were inverse linear correlations between BUN, creatinine and bone-specific alkaline phosphatase in the predialysis CRF group. We evaluated the correlations between intact parathyroid hormone (i-PTH) and biochemical and other bone markers. There was statistically significant linear correlation between i-PTH and AP. Other bone markers have no significant correlations with i-PTH. Our results demonstrated that there is significant bone loss in patients with CRF before the start of dialysis and also regional variations of BMDs in predialysis CRF patients. DXA is a useful method for evaluating regional and total BMDs and provides information about diverse regional skeletal changes. AP, i-PTH and U-DPD can predict BMD of predialysis CRF patients.

Identification of the peptides that stimulate the phosphoinositide hydrolysis in lymphocyte cell lines from peptide libraries

Peptides which stimulate the formation of inositol phosphates (InoPs) in lymphocyte cell lines were identified by screening synthetic peptide libraries composed of random sequences of hexapeptides. The peptides containing the consensus sequence XKYX(P/V)M were found to be most active in the phospholipase C (PLC)-mediated formation of InoPs in a human B myeloma cell line, U266. The peptides also stimulated the phosphoinositide hydrolysis and the release of [Ca2+]i in HL60 and U937 cell lines. On the other hand, these peptides showed no effect in the following cell lines: NIH3T3, PC12, Daudi, Sp2, Jurkat, H9, Molt-4, SupT-1, K562, and RBL-2H3. The result suggests the possibility that the peptides may have cell type specificity. Experiments with one of the active peptides, WKYMVM-NH2 showed that its action mimics the effect of AlF4- which is a G-protein activator in the InoPs generation, and pertussis toxin partially blocked the InoPs accumulation and [Ca2+]i release induced by the peptide in the U266 cells. Binding assays with the peptide labeled with 125I showed that U266 cells have a saturable number of binding sites for the peptide. Taken together, these results suggest that the peptides could activate PLC-mediated signal transduction via a pertussis toxin-sensitive G-protein coupled receptor in certain cell types.

Clinical significance of serum TSH in euthyroid patients with paroxysmal atrial fibrillation

Atrial fibrillation may occur in patients with a variety of cardiovascular or chronic disease as well as in normal subjects. Many authors reported that atrial fibrillation occurs in patients with thyrotoxicosis. It is reported that a low serum thyrotrophin concentration in an asymptomatic person with normal serum thyroid hormone concentrations can be a independent risk factor for developing atrial fibrillation. But we focused on the significance of serum thyroid stimulating hormone (TSH) in the euthyroid patient with atrial fibrillation whose serum level of T3, T4, fT4, and even TSH were absolutely within normal range. On our results, there was no significant differences in age, sexual distribution, and left ventricular ejection fraction between the patients group of paroxysmal and chronic persistent atrial fibrillation (p > 0.05), but there was larger left atrial dimension (LAD) and more cases of rheumatic heart disease in the chronic persistent atrial fibrillation group and there was more cases of lone atrial fibrillation in the paroxysmal atrial fibrillation group (p < 0.05). There was no significant differences in serum levels of T3, T4, fT4 between paroxysmal and chronic persistent atrial fibrillation, but significantly lower serum TSH was found in patients with paroxysmal atrial fibrillation (p < 0.001), and these findings were more significant after the control of hemodynamic change (p < 0.001 vs p < 0.05). The discriminant value in serum TSH between the paroxysmal and chronic atrial fibrillation group was 1.568U/mL with about 76% of predictive power. There was significantly lower serum TSH in paroxysmal atrial fibrillation in all age groups (p < 0.05). There was a significantly higher prevalence of cerebral thromboembolic events in chronic persistent (27.7%) and disease-associated (15.0% atrial fibrillation than in the paroxysmal (3.3%) and lone (4.5%) atrial fibrillation group (p < 0.001). Therefore, we suggest that serum TSH below the serum concentration of 1.5U/mL can be a risk factor for developing atrial fibrillation when the serum level of T3, T4, fT4, and even TSH were within absolutely normal range.

The value of Helicobacter pylori IgG antibody in estimating the severity of gastritis in children

A serologic test for antibodies is useful for diagnosis of Helicobacter pylori(H.pylori) infection in children. We evaluated the reliability of H.pylori IgG antibody titer in grading the severity of infection in children. We surveyed the sero-prevalence of H.pylori infection in 300 healthy school children (13 to 15 years old). Thirty-four percent(102 of 300 children) were sero-positive for H.pylori. Of the 102 sero-positive children, 70 underwent gastroscopic examination. Ninety percent of sero-positive children(63 of 70 children) were proven to be H.pylori infected. All children with H.pylori infection had histologically proven gastritis, and its severity did not correlate with the IgG antibody titer. Although a serologic test is useful to identify H.pylori infection in children, it can not predict the severity of H.pylori associated gastritis.

The role of serology in the diagnosis of Helicobacter pylori infection in children

The aim of this study was to evaluate the diagnostic accuracy of serologic tests and to verify whether specific IgG antibody can be used in the diagnosis of Helicobacter pylori infection in children without endoscopy. Serologic and endoscopic examinations were performed in 310 children (1 month-15 years) with gastrointestinal symptoms. Serologic outcomes were compared with the results of rapid urease test, histologic examination, and culture. The prevalence of H. pylori infection was 21.0% and the seropositivity of H. pylori was 24.2% in these symptomatic children. Serologic examination for diagnosis of H. pylori showed a sensitivity of 94.9% and a specificity of 92.4%, diagnostic reliability equal to the rapid urease test and histologic examination in children. The serum IgG test is a useful tool for the diagnosis of H. pylori infection, especially in children.

Hepatic capillariasis: first case report in the Republic of Korea

We report a case of massive hepatic infection by Capillaria hepatica in a 14-month-old girl who presented with the symptom triad of persistent fever, hepatomegaly, and leukocytosis with eosinophilia. Twenty-five cases of human infection with this parasite, mostly in children, have been reported in the literature. This is the first case of hepatic capillariasis reported in the Republic of Korea. The diagnosis was made by needle biopsy of the liver. Scanning electron microscopic examination of the biopsy specimen was also performed. Thiabendazole therapy was initiated and the patient developed liver disease-related IgA nephropathy during the therapy. The literature dealing with proven cases of infection with C. hepatica is briefly reviewed.

Inflammatory bowel disease in children--clinical, endoscopic, radiologic and histopathologic investigation

This paper reviews our five years' clinical experience (1987 to 1991) of 22 patients with inflammatory bowel disease (IBD). There were 12 patients with Crohn's disease and 10 patients with ulcerative colitis. The mean age at diagnosis was 8.7 years (2 to 14 years). Clinical impressions before referral were chronic diarrhea in 11, irritable bowel syndrome in 5, colon polyp in 4, lymphoma in 3, intestinal tuberculosis in 2, amoebic colitis in 2, ulcerative colitis in 2 children and other diseases. The mean interval from the onset of symptoms to the diagnosis of IBD was 18 months. Diagnosis of Crohn's disease was delayed for more than 13 months in 8 (67%), whereas that of ulcerative colitis was delayed for more than 13 months in 4 (40%). Diarrhea (50%), abdominal pain (36%) and rectal bleeding (36%) were the three most frequent presenting complaints of IBD. Moderately severe abdominal pain was a more common chief complaint in Crohn's disease (58%) than in ulcerative colitis (10%). Hematochezia (90% vs 17%) and moderately severe diarrhea (90% vs 75%) were more common gastrointestinal manifestations in ulcerative colitis than in Crohn's disease. The associated extraintestinal manifestations were oral ulcer in 7, arthralgia in 11 and arthritis in 4, skin lesions in 2, eye lesions in 2 and growth failure in 9 patients. Of 12 children with Crohn's disease, granuloma was found in 5, aphthous ulcerations in 8, cobble stone appearance in 8, skip area or asymmetric lesions in 6, transmural involvement in 7, and perianal fistula in 3. Among 10 children with ulcerative Colitis, there were crypt abscess in 8, granularity or friability in 10 and rectosigmoid ulcerations with purulent exudate in 8 children. The main sites of involvement in children with Crohn's disease were both the small and large bowels in 7 (58%), small bowel only in 2 (16%), and colon only in 3 (25%). Terminal ileum involvement was seen in 75% of Crohn's disease cases. The main sites of involvement in children with ulcerative colitis were total colon in 4 (40%), up to the splenic flexure in 2 (20%), rectosigmoid in 3 (30%) and rectum only in one (10%). Medical treatment including sulfasalazine, and systemic or topical steroid was administered initially in most patients. Seven of 12 patients with Crohn's disease and 2 of 10 patients with ulcerative colitis were operated on.(ABSTRACT TRUNCATED AT 400 WORDS)

Surgical treatment of giant cavernous hemangiomas of the liver--analysis of 7 patients

Seven patients with giant cavernous hemangioma of the liver were treated surgically with success at Pusan Gospel Hospital, Kosin Medical College, Pusan, from 1980 through 1989. They were 3 males and 4 females, and their ages ranged from 6 to 59 years. The tumors were located on the right lobe of the liver in 5 patients and on the left lobe in 2. The lesions were solitary in all patients, and their sizes varied from 4cm to 15cm in diameter. All patients underwent hepatic resection: 1 right hepatic lobectomy and 4 partial resections for tumors on the right lobe, and 1 left lobectomy and 1 left lateral segmentectomy for tumors on the left lobe. There was no surgical death, but 1 patient had a postoperative complication: multiple stress ulcers on the stomach and ileum. The pathologic diagnosis was cavernous hemangioma in all cases. In the long-term follow-up, there was no recurrence of preoperative symptoms in any patient.

Gastrointestinal manifestations of Henoch-Schönlein purpura

We report a case of the intestinal lesion in Henoch-Schönlein purpura, presented with an acute abdomen in a 4 year old boy. Five days after sudden colicky abdominal pain, skin purpura and painful joint swelling developed. These manifestations were associated with abdominal distension, hematemesis, hematochezia and hematuria. Exploratory laparotomy revealed a marked bowel distension with edema and patchy dark reddish discoloration of the jejunum and ileum. These patchy areas showed transmural hemorrhage and necrosis associated with characteristic leukocytoclastic vasculitis in and around the hemorrhagic lesions. These vasculitis was thought to be related to Henoch-Schönlein purpura.

[An immunohistochemical study on primary carcinoma of the liver]

Using 109 hepatocellular carcinomas (HCG), 34 cholangiocellular carcinomas (CCC), 4 mixed hepatocellular-cholangiocellular carcinomas (MHC) and 24 metastatic adenocarcinomas in the liver (MA), an immunohistochemical study on primary carcinoma of the liver was performed by means of the ABC method for carcinoembryonic antigen (CEA), epithelial membrane antigen (EMA), tissue polypeptide antigen (TPA) and keratin. The material consisted of surgical specimens of Kosin Medical College including 50 HCC, 17 CCC and 1 MHC, surgical specimens of 20 HCC from the University of Occupational and Environmental Health, Japan (UOEH) and autopsied specimens from UOEH that included 39 HCC, 17 CCC, 3 MHC and 24 MA. All the specimens were fixed with 10-15% formalin and embedded in paraplast manually at Kosin Medical College and by utilizing an automatic embedding machine with a decompressing procedure at UOEH. The antigenicity of TPA and keratin was preserved better in the specimens of Kosin Medical College than in those from UOEH. It is therefore assumed that manually embedded specimens are superior to specimens embedded by using an embedding machine with regard to the preservation of some antigenicities. The immunoreactivity of the 4 antigens in CCC cells was significantly higher than that in HCC cells, and the intracellular localization of antigens generally showed several characteristics in HCC and CCC. However, as the same localization of antigens is also seen in both HCC cells and CCC cells, it is considered that the immunohistochemical examination using plural antibodies is not always useful for a differential diagnosis between HCC and CCC, which is difficult in conventional sections. That TPA in HCC may be an oncodevelopmental antigen is suggested by the facts that the higher the grade of HCC, the higher the immunoreactivity of HCC cells, that hepatocytes with possible higher activity sometimes showed a positive reaction in the present study and that TPA is expressed in fetal hepatocytes in a fetus up to 20 weeks in the literature.

Development of intestinal host defense: an increased sensitivity in the adenylate cyclase response to cholera toxin in suckling rats

To determine if developmental variations existed in the second messenger system that mediates cholera toxin (CT) action, the adenylate cyclase (AC) response was studied in 2-wk-old suckling and 6-wk-old weaned rats. AC was assayed in the proximal small intestine 4 h after intraduodenal administration of various doses of CT. Dose-effect analysis showed a 9-fold increase in the sensitivity of the CT-activated cyclase response in suckling rats when measured by the ED50, expressed as microgram CT/g body wt (0.03 for 2 wk, 0.27 for 6 wk). When the CT dose was expressed as microgram/animal, suckling rats were 50 times more sensitive than 6-wk-old rats. In addition, the CT-induced fluid secretion was closely correlated with the elevated cyclase activities (correlation coefficient: 0.83 for 2 wk, 0.93 for 6 wk). Furthermore, more fluid seemed to be secreted/unit wt of gut in the sucklings, even when the same level of enzyme activity was compared. A maximum of 3- to 4-fold rise in AC activation occurred at 0.5 microgram CT/g body wt, but both the basal and the maximal stimulated levels of AC were not developmentally different. This study demonstrates an in vivo increase in AC responsiveness to CT that may be in part responsible for the increased incidence of toxigenic diarrhea in neonates.