Overview of rotavirus infections in Korea

Rotavirus is the most common cause of acute watery diarrhea in young Korean children. Rotavirus vaccine will soon be available, and information is urgently required about the serotype distribution of recent epidemics and clinical characteristics of rotavirus infection in Korean children before the implementation of a vaccination program against rotavirus. We reviewed published studies of the past 20 years, carried out on Korean children with rotavirus gastroenteritis. Rotavirus was estimated to be responsible for 46% of 4668 hospitalized Korean children with acute gastroenteritis. Rotavirus gastroenteritis was most prevalent among children aged 6-24 months, which accounted for 84% of all cases. Asymptomatic rotavirus infection was common. Rotavirus was one of the most commonly identified enteric pathogens in nosocomial diarrhea. Vomiting, respiratory symptoms and fever were prominent symptoms in rotavirus gastroenteritis. Transient elevation of liver enzymes, pulmonic infiltration and rarely afebrile convulsion were also observed. The epidemic peak, which occurred in November of the last 15 years, has been moving toward late winter and early spring in recent years. No apparent cause has been found to explain this alteration of peak seasonality. All serotyping studies in Korea for the past 10 years until 1997 revealed that G1 was most prevalent (45-81%). Interestingly, the predominant G serotype of the recent outbreaks in 1998 and 1999 was not G1 but G4. Approximately 95% of rotavirus isolates in recent outbreaks belonged to serotype G1, 2, 3 or 4.

Congenital intrahepatic portohepatic venous shunt: treatment with coil embolisation

Congenital abnormalities of the portal venous system are rare. There are few radiological descriptions of intrahepatic portosystemic venous shunt detected in the perinatal period. We report a congenital portosystemic shunt that was detected by US and treated with coil embolisation in the neonatal period.

Multicenter study of the treatment of erectile dysfunction with transurethral alprostadil (MUSE) in Korea

A Korean multicenter study was conducted to assess the effectiveness of transurethral alprostadil with MUSE in 334 subjects with chronic erectile dysfunction (ED) who were enrolled in 21 clinical centers. Patients with psychogenic impotence comprised about 30% of subjects. Intraurethral alprostadil was titrated in a stepwise fashion in the clinics from 250 to 500 or 1000 mcg based on erectile response and tolerability. The erectile responses were evaluated using an erection assessment scale (score of 1-5). The dose that produced a maximal penile response of score 5 (full rigid erection) or 4 (full tumescence, partial rigidity) was selected for home treatment. Patients who showed partial erection (score of 3) with 1000 mcg were also included in the home-treatment group. In-clinic phase: 198 men (59.3%) had maximal penile responses of score 4 or 5. The rate of maximal responses was not related to patient age, etiology or duration of the ED. A total of 228 (68.3%) men progressed to home treatment. The overall level of comfort of the transurethral alprostadil was rated as uncomfortable or very uncomfortable in 12%. Home phase: During the two-month period of home treatment, 178 (78.1%) men had successful sexual intercourse at least once, and 78.2% of administrations (1976) resulted in successful intercourse. The main causes of drop-out were insufficient erectile response in 27 men (11.8%), adverse reactions (mostly penile or urethral pain) in 7 (3.1%) or both in 7 (3.1%). In conclusion, transurethral alprostadil could be a suitable treatment option for patients with ED regardless of age and etiology of ED. Efficacy in an Asian population (Korea) is comparable to that reported previously in Caucasians.

Transoral protrusion of a peritoneal catheter: a case report and literature review

Transoral protrusion of a peritoneal catheter is rare. Only two cases have been reported in the English literature. We now report the case of a 5-year-old girl who presented with a catheter that had been inserted 4 years previously, protruding from her mouth. Signs of cerebrospinal fluid infection or peritonitis were absent. The peritoneal catheter was cut and externalized at the chest. The distal portion, which had perforated the stomach wall, was removed using endoscopic procedures. After 3 weeks of antibiotic treatment, a new shunt was inserted. Analysis of 50 cases of bowel perforation extracted from the English literature showed that among the suggested factors such as age, gender, nutritional state, history of abdominal surgery, and length and type of the catheter, age was the only predisposing factor. In the treatment of bowel perforation by a peritoneal catheter, suspected shunt infection should be managed properly and contamination be minimized during removal of the peritoneal catheter.

Trp-Lys-Tyr-Met-Val-Met activates mitogen-activated protein kinase via a PI-3 kinase-mediated pathway independent of PKC

Trp-Lys-Tyr-Met-Val-Met (WKYMVM) is a novel potent peptide which can stimulate phosphoinositide hydrolysis in U937 as well as U266 and HL-60 cells (Baek et al., J. Biol. Chem. 271, 8170 (1996)). The peptide also induces superoxide generation in human neutrophils (Seo et al., J. Immunol. 158, 1896 (1997)). However, the signaling pathway down-stream of PLC set in motion by the peptide is not yet completely understood. We studied the signaling pathway of the peptide with the goal of elucidating the mechanism of the peptide's action. WKYMVM induced a rapid and transient activation of the ERKs in human histiocytic lymphoma cells, U937. The ERK1 activation peaked at 5 min and returned to the basal level after 30 min. The ERK1 stimulation by the peptide was partially inhibited by pretreatment of the cells with pertussis toxin (PTX), implicating G-protein involvement in the peptide's action. Pretreatment of staurosporine, protein kinase C (PKC) inhibitor, or PKC down-regulating PMA had no impact on the ERK1 activation by the peptide, indicating that the signaling pathway is independent of PKC activation. Pretreatment of the cells with neomycin and intracellular Ca2+ mobilizing reagents had also no effect on the ERK1 activation by the peptide. However, pretreatment with wortmannin or LY294002, the inhibitor of phosphatidylinositol 3 kinase (PI-3K), strongly inhibited peptide-stimulated ERK1 activation. Our results suggest that PI-3K may be an important participant in the ERK cascade induced by the peptide. Furthermore, the treatment of U937 cells with the peptide activated p74Raf-1, an upstream kinase of ERK. Taken together, our results suggest that the peptide activate ERK via a G-protein/PI-3K/Ras/Raf-1 mediated signaling pathway in U937 cells.

Pulmonary hypertension in a child with juvenile-type autosomal recessive polycystic kidney disease

An 11 year-old girl, whose condition was diagnosed as juvenile-type autosomal recessive polycystic kidney disease (ARPKD) at five years of age, presented with chest pain and dyspnea that had developed suddenly two months previously. Two-dimensional echocardiography, Doppler study and cardiac catheterization confirmed pulmonary hypertension. The underlying mechanism of the diagnosis was not defined. Two and a half months after the onset of symptoms, the patient died of pulmonary hypertensive crisis. Careful regular checks of cardiopulmonary status using two-dimensional echocardiography and Doppler should be considered for the early detection of pulmonary hypertension even in an asymptomatic patient with juvenile-type ARPKD.

Trp-Lys-Tyr-Met-Val-D-Met stimulates superoxide generation and killing of Staphylococcus aureus via phospholipase D activation in human monocytes

Among the phagocytic leukocytes, monocytes have the important role of clearing out parasitic microorganisms. They accomplish this through production of toxic metabolites of oxygen. Trp-Lys-Tyr-Met-Val-D-Met (WKYMVm), a peptide that stimulates phosphoinositide (PI) hydrolysis in human leukocytes, including monocytes, binds to a unique cell surface receptor and stimulates superoxide generation, killing of Staphylococcus aureus, and activation of phospholipase D (PLD) in human monocytes. Preincubation of the cells with a PI-specific phospholipase C (PLC) inhibitor (U-73122), protein kinase C inhibitor (GF109203X), or intracellular Ca2+ chelator (BAPTA/AM) before the peptide stimulus totally inhibits the peptide-induced PLD activation and superoxide generation. On the other hand, tyrosine kinase inhibitor genistein only partially inhibits the peptide-induced processes. The peptide-induced bacteria killing activity shares regulatory mechanisms for PLD activation with the superoxide generation, which is inhibited in the presence of 1-butanol. We suggest that the peptide stimulates PLD downstream of PLC activation and PLD activation in turn is essential for the peptide-induced immunological functions such as the superoxide generation and killing of bacteria by human monocytes.

Endoscopic management of gastrointestinal foreign bodies in children

Endoscopic removal of foreign bodies (FBs) is an important part of therapeutic endoscopy in children. Children most often ingest coins, pins, keys, round stones or marbles, nails, rings, batteries and toys. Coins were the most common FB in the pediatric series of 139 children, who underwent endoscopic removal in Seoul National University Children's Hospital, Korea. The management of FBs depends on the type (sharp or dull, pointed or blunt, and toxic or nontoxic) and the size, along with the location of FB in the gastrointestinal tract. The endoscopist should decide whether endoscopic intervention is necessary and how urgently it has to be done. Indications for removal of FBs from the gastrointestinal tract in children are 1) All esophageal FBs, 2) Gastric or duodenal FBs if they are sharp or pointed, of more than 4 cm long or 2 cm wide in young infants and children; if containing toxic substances and if blunt objects remaining after 2 week observation in the stomach or 1 week observation in the duodenum. Esophageal FBs should be removed within 24 hours because of the risks of perforation and serious fistula formation. Disk batteries can cause corrosive injury to the esophagus within 4 hours. Coin retrieval can be done using the W-shape FB grasping forceps without an endotracheal general anesthesia. Blunt FBs, such as marbles can be best removed with a stone retrieval basket, which can be made from a condom. Disk batteries cannot be grasped with the FB forceps and snares, but very safely with the powerful magnet attached to the tip of the scope. Overtubes and protective rubber hoods are useful for removing sharp or pointed objects. It is important to test the available grasping accessories on a duplicate of the FB as a "dry run" to determine which accessories will grasp the FB securely.

Choledochal cyst with or without biliary atresia in neonates and young infants: US differentiation

PURPOSE

To differentiate at ultrasonography (US) between the choledochal cyst associated with biliary atresia (CCBA) and that in the absence of biliary atresia (CC) in neonates and young infants.

MATERIALS AND METHODS

Preoperative US findings in 28 neonates and infants younger than 4 months in whom choledochal cyst was subsequently surgically confirmed were retrospectively analyzed. There was no statistically significant difference in age between the CCBA group (n = 19) and the CC group (n = 9). US findings in both groups were compared, with focus on the size of the cyst in the hepatic portal, dilatation of the intrahepatic bile ducts, and the size and morphology of the gallbladder.

RESULTS

At US, the width and length of the cysts in the hepatic portal in the CC group were significantly larger than those in the CCBA group (P < .001). Dilatation of the intrahepatic bile ducts, seen in only one patient (5%) of the CCBA group, was observed in all patients (100%) of the CC group. The gallbladder was normal or distended in all patients of the CC group, while it was atretic or irregularly elongated in 17 patients (89%) of the CCBA group.

CONCLUSION

US can be helpful in the preoperative differential diagnosis of choledochal cysts in neonates and infants. Cysts are larger, intrahepatic ducts are dilated, and gallbladders are not atretic in patients with CC as compared with those in patients with CCBA.

Radiological features of focal nodular hyperplasia of the liver in children

BACKGROUND

Focal nodular hyperplasia (FNH) is an unusual hepatic tumour in children and should be distinguished from other hepatic lesions.

OBJECTIVE

To describe the imaging characteristics of FNH in children.

MATERIALS AND METHODS

We examined five patients (three boys and two girls, mean age 9.4 years) with pathologically confirmed FNH. The diagnosis was obtained by tumour resection (n = 4) and percutaneous needle biopsy (n = 1). One patient with multiple FNHs showed recurrent lesions after tumour resection. All patients were studied with US (including colour and power Doppler US [n = 3]) and CT. Dynamic enhanced CT scans were available in three patients. MRI (n = 2) or coeliac angiography (n = 1) was performed in three patients.

RESULTS

Seven of eight FNH lesions in five patients were demonstrated by imaging. The average size of the lesions was 6.5 cm. Six lesions detected on US showed variable echogenicity with a central hyperechoic scar (n = 2). On Doppler examination, central or peripheral hypervascular areas were seen (n = 3). Six lesions detected on contrast-enhanced CT showed high attenuation (n = 4) or iso-attenuation (n = 2). On early phase scans, all the lesions (n = 3) showed high attenuation. Irregular linear or ovoid central scars were detected in two patients on CT. MR demonstrated three lesions in two patients, one of which had not been detected by US or CT. A central low signal intensity scar (n = 1) was seen on T2-weighted MRI. Coeliac angiography performed in one patient showed a hypervascular mass with homogeneous staining.

CONCLUSION

FNH in children shows a wide spectrum of imaging findings on various radiological examinations and the typical central scar was not always seen on imaging studies. Dynamic enhanced CT obtained in the early phase and colour Doppler studies may be helpful in the diagnosis of FNH by allowing characterisation of tumour vascularity. FNH should be included in the differential diagnosis of liver mass in children.

Computed numerical analysis of the biomechanical effects on coronary atherogenesis using human hemodynamic and dimensional variables

The objectives of this investigation were to evaluate biomechanical factors in the atherosclerotic process using human in vivo hemodynamic parameters and computed numerical simulation qualitatively and quantitatively. The three-dimensional spatial patterns of steady and pulsatile flows in the left coronary artery were simulated, using a finite volume method. Coronary angiogram and Doppler ultrasound measurement of the proximal left coronary flow velocity were performed in humans. Inlet wave velocity distribution obtained from in vivo data of the intravascular Doppler study allowed for input of in vitro numerical simulation. Hemodynamic variables, such as flow velocity, pressure and shear stress of the left anterior descending coronary bifurcation site were calculated. We found that there were spatial fluctuation of flow-velocity and recirculation areas at the curved outer wall of the left anterior descending coronary artery, which were due to the differences of flow-velocity and shear stress, especially during the declaration phase of pulsatile flow. This study suggests that rheologic properties may be a part of the atherogenic process in the coronary bifurcated and curved areas.

Distribution of the receptor for a novel peptide stimulating phosphoinositide hydrolysis in human leukocytes

OBJECTIVES

Previously we reported that a synthetic peptide, WKYMVm, stimulates phosphoinositide (PI) hydrolysis in several hematopoietic cell lines and human neutrophils. In addition, the peptide induces superoxide generation in human neutrophils. The biochemical stimulation appeared to be mediated by specific receptors on leukocytes. In this report we try to find whether the specific receptor(s) exists on specific types of cells in human leukocytes.

DESIGN AND METHODS

To study distribution of the peptide-specific receptors, we prepared a probe, biotin-labeled WKYMVm, and analyzed distribution of the peptide receptor using a biochemical study, cytochemical staining, and flow cytometric analysis.

RESULTS

The peptide-specific receptors are expressed in several human leukocytes including granulocytes, monocytes, and B-lymphocytes but not T-lymphocytes and erythrocytes.

CONCLUSIONS

These data suggest that the receptors for the peptide restricted to certain types of leukocytes and this specificity is probably related to the specific functions of the stimulated leukocytes.

Acute pyelonephritis focusing on perfusion defects on contrast enhanced computerized tomography(CT) scans and its clinical outcome

OBJECTIVES

Many cases of acute pyelonephritis show renal perfusion defects on contrast enhanced computerized tomography (CT) imaging studies. The purpose of this study is to show the frequency of renal perfusion defects in uncomplicated acute pyelonephritis and to compare the clinical responses of patients who had perfusion defects or not.

METHODS

We studied patients who had symptoms and signs of acute pyelonephritis through CT examinations with contrast enhancement. We identified 21 cases who had perfusion defects among 35 patients who had undergone CT imaging studies and compared the clinical data in the two groups of patients who had perfusion defects on CT (group 1) and who had not (group 2).

RESULTS

Nearly all patients had typical symptoms and signs of acute pyelonephritis such as high fever and chill, flank pain and costovertebral angle tenderness. Combined clinical problems were septic shock (one case, 4.8%) and disseminated intravascular coagulation (DIC) (one case, 4.8%) in group 1. Laboratory findings were not different between the two groups. All patients were treated with antibiotics and had successful recoveries. The duration of recovery of pyuria in group 1 (5.2 +/- 9.6 days) was not longer than that in group 2 (3.1 +/- 2.9 days) (p > 0.05). The length of defeverscence in group 1 (7.0 +/- 4.6 days) was longer than in group 2 (3.5 +/- 2.7 days) (p < 0.05). There were no differences between group 1 and group 2 in the rate of predisposing factors. Thirteen of 21 cases (61.9%) in group 1 and five of 14 cases (35.7%) in group 2 had positive urine culture results which are relatively low probably due to the administration of antibiotics prior to our emergency room visit. Perfusion defects on CT were very frequent findings (60.0% of the clinical acute pyelonephritis patients). We classified CT findings of group 1 as focal unilateral (2 cases, 9.5%), multifocal unilateral (14 cases, 66.7%) and multifocal bilateral (5 cases, 23.8%), and there were no differences between the subgroups of group 1 in the duration of defeverscence.

CONCLUSION

Those patients who had perfusion defects on CT showed relatively severe clinical courses but responses to early antibiotics were very good. Contrast enhanced CT scans may be very sensitive for the detection of acute renal parenchymal inflammatory disease and for defining the extent of disease, but it is clinically not essential to perform in the early uncomplicated acute pyelonephritis because CT diagnosis does not change management. Clinical use of contrast enhanced CT scan may be appropriate in case of persistence of fever and leukocytosis for more than seven days despite antibiotic treatment.

Therapeutic endoscopy: removal of gastrointestinal foreign bodies in children

Endoscopic removal of foreign bodies (FBs) is an important part of therapeutic endoscopy in children. The majority of FB ingestion occur in children under 5 years. Children most often ingest coins, pins, keys, round stones or marbles, nails, rings, batteries and toys, and coins are the most common in the pediatric series of 139 children, who underwent endoscopic removal in Seoul National University, Children's Hospital. The management of FBs in children depends on the type (sharp or dull, pointed or blunt, and toxic or nontoxic) and the-size, along with the location of FB in the gastrointestinal tract. The endoscopist should decide whether endoscopic intervention is necessary and how urgently it has to be done. Indications for removal of FBs from the gastrointestinal tract in children are 1) all esophageal FBs. 2) gastric and duodenal FBs if they are sharp or pointed, if more than 4 cm long or 2 cm wide in young infants and children, if containing toxic substances and if blunt objects after 2 weeks observation in the stomach or 1 week observation in the duodenum. All FBs impacted in the esophagus should be removed within 24 hours because of the risks of perforation and serious fistula formation. Disk batteries can cause corrosive injury to the esophagus within 4 hours, and should be removed as soon as possible. Coin retrieval can be done very securely by the W-shape FB grasping forcep without an endotracheal general anesthesia. Blunt FBs, such as marbles can be best removed with a stone retrieval basket, which can be made from a condom. Disk batteries can not be grasped with the FB forceps and snares, but very safely with the powerful magnet attached to the tip of the scope. Overtubes and protective rubber hoods are useful for removing sharp or pointed objects. It is important to test the available grasping accessories on a duplicate of the FB as a "dry run" to determine which accessories will grasp the FB securely.

Extrarenal manifestations of autosomal dominant polycystic kidney disease

Recently, with the widespread use of new imaging techniques, the diagnosis of autosomal dominant polycystic kidney disease (ADPKD) is increasing. To analyze the extrarenal manifestations of ADPKD in Korean patients, we retrospectively studied the clinical characteristics of 30 patients with ADPKD. Thirty Patients with ADPKD who had been diagnosed at Yongdong Severance Hospital from 1988 through 1994 were recruited for this study. All patients' past and family histories were re-evaluated, and charts and radiologic images were reviewed retrospectively. The male to female ratio was 9:21, and the age of initial diagnosis was 39.2 +/- 13.8 (mean +/- SD) years. In 15 cases (50%), ADPKD had been diagnosed by renal symptoms; in 8 cases (26.7%), by chance during evaluation of extrarenal diseases; in 5 cases (16.7%), by family screening; and in 2 cases (6.7%), by uremic symptoms. Extrarenal involvement included hepatic cysts (70%), pancreatic cysts (16.7%), splenic cysts (6.7%), thyroid cysts (6.7%), inguinal hernia (3.3%), and colonic diverticula (3.3%). In 5 cases (16.7%), cardiac valvular abnormalities were noted by echocardiography. Seven patients underwent hemodialysis, and the duration from the initial diagnosis to initiation of dialysis was 9.9 +/- 8.5 (mean +/- SD) years. We investigated the extrarenal manifestations of 30 cases of ADPKD in Koreans, which were also common and clinically important as renal manifestations. Renal cysts are only one of a myriad of renal and extrarenal manifestations of ADPKD. ADPKD should be managed systematically since this disorder is a systemic disease with clinically important involvement of the cardiovascular system, the gastrointestinal tract, the genitourinary system, and the musculoskeletal system.

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.

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.