Effects of intrapancreatic neuronal activation on cholecystokinin-induced exocrine secretion of isolated perfused rat pancreas

The role of intrapancreatic neurons in the action of cholecystokinin (CCK) on pancreatic exocrine secretion of the totally isolated, perfused rat pancreas was investigated. Intrapancreatic neurons were activated by applying electrical field stimulation (EFS) to the isolated pancreas for 45 min. When applying EFS, spontaneous pancreatic secretions of fluid and amylase increased until the second 15-min period of EFS and then decreased during the third 15-min period. Atropine (2 microM) notably reduced the EFS-evoked pancreatic secretions of fluid and amylase. The CCK-induced (10 pM) pancreatic secretions of fluid and amylase elevated further in the first 15-min period of EFS and then gradually resumed to the levels observed during application of CCK alone in the third 15-min period of EFS. However, the CCK-induced pancreatic secretions remained elevated even in the third 15-min period of EFS when an action of endogenous somatostatin was inhibited by cyclo-(7-aminoheptanonyl-Phe-d-Trp-Lys-Thr[BZL]) (10 nM) or pertussis toxin (200 ng/ml). EFS further elevated spontaneous exocrine secretion by the cysteamine-treated (300 mg/kg) pancreas, but this was markedly reduced, to normal levels, by infusing somatostatin (100 pM). EFS increased the numbers of immunoreactive somatostatin cells in the Langerhans' islets. The results indicate that intrapancreatic neuronal activation influences CCK-induced pancreatic secretions in a dual-phase pattern in the rat: an increase during the early phase and a decrease during the late phase. Endogenous somatostatin released from the islets appears to inhibit the enhancing effect of neuronal activation on CCK-induced pancreatic secretion. Of the intrapancreatic neurons, the cholinergic ones appear to predominate in EFS's effects on CCK-induced pancreatic secretion.

Detection of p16 gene alteration in cervical cancer using tissue microdissection and LOH study

The p16 gene was identified as cyclin-dependent kinase inhibitor (CDKI) and this may negatively regulate the cell cycle by acting as a tumor suppressor. Using tissue microdissection, the molecular changes at p16 and Rb genes were analysed in the spectrum of disease from dysplasia to invasive cancer of the uterine cervix. Six of 27 (22%) cases informative for D9S171 and IFNA of 9p21-22 marker (p16INK4a) showed loss of one or both alleles in at least one of these loci. LOH of pRb was detected in 29% (5/17). Gene alterations at p16 and pRb loci were only detectable in some cases of HPV-16/18 DNA positive cervical cancer. Three cases demonstrated mutational changes of p16INK4a, and the alterations were determined to be G to T shift, suggesting transitional missense mutation. In summary, the inactivation of the p16/cdk-cyclin/Rb cascade may play an additional role during the malignant progression in HPV-16/18 positive cervical cancers.

Quality of life in Korean patients with inflammatory bowel diseases: ulcerative colitis, Crohn's disease and intestinal Behçet's disease

Health-related quality of life (HRQOL) is an important outcome factor in chronic diseases such as inflammatory bowel disease (IBD). This study used the Korean translation of the disease-specific, self-administered Inflammatory Bowel Disease Questionnaire (IBDQ) to compare HRQOL in ulcerative colitis (UC; n = 98), Crohn's disease (CD; n = 49), and intestinal Behçet's disease (BD; n = 34). In addition to the current status, patients were asked retrospectively to recall their symptoms at the beginning and during the worst period of their disease. Disease activity was measured by St. Mark's Activity Index, Crohn's disease Activity Index (CDAI), and the Harvey-Bradshaw Index (HBI). In all IBD patients, including those with BD, the IBDQ total score during the worst period was significantly lower than that at present and that at the beginning of the disease. However, there were no significant differences between groups regarding the total IBDQ score or its various dimensions. In UC a strong correlation between IBDQ scores and St. Mark's Activity Index was observed (r = -0.708, P < 0.001). IBDQ scores were also highly correlated with CDAI and HBI in both CD (r = -0.506, P < 0.001 for CDAI; r = -0.600, P < 0.001 for HBI) and BD (r = -0.687, P < 0.001 for CDAI; r = -0.531, P < 0.001 for HBI). However, the current IBDQ score was not related to demographic parameters such as gender, age, educational status, economic status, and marital status as well as disease factors such as duration of disease, history of operation or hospital admission, extent of disease in UC, involved region in CD, and clinical type in BD. We conclude that the Korean IBDQ is a responsive and promising instrument for measuring HRQOL of IBD patients in clinical trials. In addition, the IBDQ can be helpful in developing a disease-specific activity index in BD.

NMDA receptor antagonists enhance 5-HT2 receptor-mediated behavior, head-twitch response, in mice

The purpose of this study was to characterize behavioral interactions between glutamatergic and serotonergic 5-HT2 receptors. Both competitive (AP-5 [D-2-amino-5-phosphovalerate] and D-CPP [3-(2carboxypiperazine-4yl)-propylphosphonate]) and noncompetitive (MK-801 [dizocilpine], ketamine, dextrorphan and dextromethorphan) N-methyl-D-aspartate (NMDA) receptor antagonists markedly enhanced a selective serotonergic behavior, the head twitch response (HTR), in mice. In contrast, NMDA itself inhibited 5-hydroxytryptamine (5-HT)-induced HTR in mice. These results suggest that glutamatergic neurotransmission may modulate serotonergic function at the 5-HT2 receptor.

Preferential expression of insulin-like growth factor binding proteins-1, -3, and -5 during early diabetic renal hypertrophy in rats

The renal insulin-like growth factor-I (IGF-I) system has been implicated in the pathogenesis of renal hypertrophy, altered hemodynamics, and extracellular matrix expansion associated with early diabetes. The relative abundance of IGF binding proteins (IGFBPs) in the renal microenvironment may modulate IGF-I actions. However, the precise IGFBPs expressed in the glomerular and tubulointerstitial compartments during diabetic renal growth have not been characterized. In the present study, in situ hybridization studies were performed to examine the expression of IGFBP-1 to -6 messenger RNAs (mRNAs) 3, 7, and 14 days after streptozotocin (STZ) injection in rats. In control, nondiabetic kidneys, all six IGFBP mRNAs were differentially expressed with a predominance of IGFBP-5. The onset of renal hypertrophy in STZ-induced diabetes was associated with a rapid and site-specific induction of IGFBP-1, -3, and -5 mRNAs. In contrast, basal expression of IGFBP-2, -4, and -6 mRNAs was not altered in diabetic rats. IGFBP-5 mRNA expression increased in diabetic glomeruli, cortical, and inner medullary peritubular interstitial cells at days 3, 7, and 14. Although normal glomeruli failed to express IGFBP-3, it was induced concomitantly with IGFBP-5 in diabetic glomeruli and cortical peritubular interstitial cells. IGFBP-1 mRNA levels also increased in cortical tubular cells at each time point tested. Peak induction of IGFBP-3 and -5 was observed at day 3, whereas IGFBP-1 was delayed until day 7. IGFBP-1, -3, and -5 mRNA levels declined by day 14, but remained persistently elevated above control. By immunoperoxidase staining, similar alterations in the pattern of IGFBP-3 and -5 protein expression were observed at each time point. The preferential and site-specific increase in IGFBP-1, -3, and -5 suggest that these IGFBPs may regulate the local autocrine and/or paracrine actions of IGF-I and contribute to the pathogenesis of the early manifestations of diabetic nephropathy.

Thiolated Salmonella antibody immobilization onto the gold surface of piezoelectric quartz crystal

An improved antibody-coated sensor system based on quartz crystal microbalance analysis on Salmonella spp. was developed making use of thiolated antibody immobilization onto one gold electrode of the piezoelectric quartz crystal surface. The best results in sensitivity and stability were obtained with the thin layer of a thiol-cleavable, heterobifunctional cross-linker, sulfosuccinimidyl 6-[3-(2-pyridyldithio)propionamido]hexanoate (sulfo-LC-SPDP). The long bridge of this reagent could function as a spacer, facilitating antibody-Salmonella interaction on the gold electrode. After the addition of a S. typhimurium suspension into a reaction cell with 0.1 M sodium phosphate buffer, pH 7.2, the resonant frequency decreased conspicuously. The time required for maximum frequency shift was about 30-90 min. Sensor response was observed for the microbial suspensions ranging from 9.9 x 10(5) to 1.8 x 10(8) CFU/ml.

Radiofrequency pulmonary valvotomy using a new 2-French catheter

We report the usefulness of a new 2-French (F) electrode catheter for perforating the atretic pulmonary valve in patients with pulmonary atresia and intact ventricular septum, using radiofrequency energy. The new 2-F electrode catheter was used in three patients. The first patient, weighing 2.1 kg, with pulmonary atresia and an intact ventricular septum, underwent transcatheter valvotomy at the age of 18 days. Due to massive left ventricular volume overload, the patient required surgical ligation of the ductus arteriosus, but she was discharged uneventfully after that. The second patient, weighing 2.2 kg, had Ebstein's anomaly with pulmonary atresia and an intact ventricular septum. She underwent transcatheter valvotomy at the age of 30 days. Although she was weaned from prostaglandin E1 infusion, she died suddenly (presumed septicemic). A postmortem examination showed a split pulmonary valve. The third patient, weighing 2.3 kg, with pulmonary atresia and an intact ventricular septum, underwent transcatheter valvotomy at the age of 17 days. Prostaglandin E1 infusion was discontinued on the 3rd day after the transcatheter valvotomy and she was discharged uneventfully.

Induction of apoptosis in colon cancer cells by nonsteroidal anti-inflammatory drugs

Epidemiological studies have demonstrated that nonsteroidal anti-inflammatory drugs (NSAIDs) decrease the incidence of colon cancer. In addition, NSAIDs reduce the number and size of polyps in patients with familial adenomatous polyposis. The mechanisms of the anti-neoplastic effect of NSAIDs are still far from complete understanding, but one possible mechanism is the induction of apoptosis. Several lines of evidence suggest that NSAIDs-induced apoptosis in colon cancer cells are mediated through the cyclooxygenase (COX)-independent pathway. In this study we explored the mechanism of NSAIDs-induced apoptosis in the colon cancer cell line, HT-29. We confirmed that NSAIDs induce apoptosis in HT-29 cells irrespective of their COX-selectivity. Indomethacin enhanced the expression of p21waf-1 in HT-29 cells. However the expression of apoptosis-related genes such as Fas, bcl-2 and bax was not affected by indomethacin. Intra- and extra-cellular calcium chelators, protein tyrosine kinase (PTK) inhibitor, protein kinase A (PKA) inhibitor and protein kinase C (PKC) inhibitors did not influence indomethacin-induced apoptosis in HT-29 cells. We concluded that NSAIDs-induced apoptosis in colon cancer cells may be independent from signals transducted through [Ca++]i, PTK, PKA, PKC or the expression of apoptosis-related genes. In contrast, our results demonstrating the induction of p21waf-1 transcription by NSAIDs suggest the possible association of NSAIDs-induced apoptosis and cell-cycle control in colon cancer cells.

Cytokinetic pattern in the thoracic spinal cord of chick embryos (incubation day 5-13) using PCNA staining and TUNEL method

For the cytokinetic studies using spinal cords of chick embryos, chronological patterns of cell proliferation and programmed cell death (apoptosis) should be known. Information in the early stages of chick embryos is available while data on later stages are seldom available. To investigate the chronological patterns of cell proliferation and apoptosis in the thoracic spinal cord of normal chick embryos on incubation day 5, 6, 8, 10 and 13 (Hamburger and Hamilton stage 26-40), proliferating cell nuclear antigen (PCNA) staining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) method were used. Cell proliferation was active at the germinal layer on days 5 and 6. It markedly declined on day 8 and became negligible on day 13. TUNEL-positive cells were mainly found in the germinal layer, the ventrolateral part of the mantle layer and the dorsal root ganglion. Compared to PCNA-positive cells, TUNEL-positive cells were sparse, especially after day 10, when only a few positive cells were scattered. These results will be used as a control data for the studies such as an experimental research for neural tube defects.

Laser-to-fiber optical coupling scheme with a long working distance by use of thermally overexpanded fiber

A laser-diode-optical-fiber coupling scheme that uses aspherically ended thermally overexpanded fiber is proposed. The scheme is verified by both an analytical formalism and a wide-angle beam-propagation method analysis in cylindrical coordinates.

Transient expression of clusterin (sulfated glycoprotein-2) during development of rat pancreas

Clusterin has been known to play important roles not only in remodeling damaged tissues, but also in tissue reorganization during embryonic development. In the present study, we have investigated the expression of clusterin in the endocrine pancreas during embryonic development. Although a weak immunoreaction was detected in some pancreatic primordial cells at day 14 of gestation, distinct clusterin expression was identified by immunocytochemistry and Northern blot analysis at the 16th day of gestation. Clusterin-producing cells, which corresponded to insulin-containing cells, accounted for the major portion of the developing islet of Langerhans up to 18 days of gestation. Thereafter, clusterin-producing cells display similar distribution and morphological features to glucagon-producing cells. Clusterin expressed in the pancreas was shown by Western blot analysis to be a disulfide-linked heterodimer of 70 kDa with an alpha-subunit of 32 kDa. During early developmental stages, however, we found that proteolytic internal cleavage of the clusterin molecule occurred from the 18th day of gestation. Only one 70 kDa band on the 16th day and two bands (32 kDa and 70 kDa) on the 18th day of gestation were detected by Western blot analysis even in reducing conditions, while only a single 32 kDa band was detected on the second day after birth. The levels of clusterin mRNA in the pancreas transiently increased from the 16th day of gestation to the second day after birth, during the period when active cellular reorganization takes place to form the classic cellular features of the islet. Among various tissue (kidney, brain, liver, heart, lung and pancreas) the levels of clusterin mRNA were the highest in the pancreas from the 18th day of gestation to the second day after birth. In contrast, the lowest expression was observed in adult pancreatic tissue. The higher expression of clusterin in developing pancreas must indicate its involvement in tissue organization during development.

Digital infrared thermographic imaging in patients with gastroesophageal reflux disease

We performed a thermographic study to observe any possible interaction between the esophageal acid perfusion and the temperature changes of skin surface in patients with gastroesophageal reflux disease (GERD). Twenty-seven patients with GERD were categorized as group I(globus symptoms with posterior laryngitis) and group II (heartburn and/or regurgitation symptoms). Patients and 6 healthy volunteers underwent Bernstein test (BT) and digital infrared thermographic imaging (DITI) simultaneously. The positive rate for BT in group I and group II was 22.2% and 55.6%, respectively, and the DITI positive rate was 55.6% for group I and 50.0% for group II. None of healthy control were positive in BT or DITI. All subjects with DITI positive were hypothermic. The overall accordance rate between DITI and BT was 69.7%. All group I patients showed a diffuse type, while in group 11, 4 patients showed diffuse type and 5 patients showed localized type (p<0.05). In patients with DITI (+)/BT (-), 83.3% showed diffuse type, whereas equal numbers of diffuse and localized type were noted in patients with DITI (+)/BT (+). In conclusion, add contact with a sensitive mucosa leads to an activation of the sympathetic nervous system in some patients with GERD, inducing skin surface hypothermia.

Cell kinetics of surgically induced spinal open neural tube defect in chick embryos

In an attempt to understand cell kinetics of open neural tube defects (ONTDs) in the embryonic stages, chronological changes of cell proliferation and cell death patterns in the surgically induced spinal ONTDs of chick embryos were investigated using proliferating cell nuclear antigen (PCNA) staining and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP) nick end labeling (TUNEL) method. ONTDs were induced at Hamburger and Hamilton stages 17-19. Compared with the control group, the surgery group showed a lower PCNA labeling index for 5 days after surgery and demonstrated more TUNEL-positive cells at 6 h, 3 and 5 days after surgery. Decreased cell proliferation and enhanced apoptosis were seen in the ventral as well as in the dorsal spinal cord. These results partly explain the functional deficits of ONTDs.

Acute gastroparesis in Duchenne's muscular dystrophy

Duchenne's muscular dystrophy (DMD) is an X-linked recessive disease. Clinical descriptions of the disorder focus principally on skeletal muscle degeneration. Another manifestation, which involves the gastrointestinal tract, may be fatal. But its prevalence remains undefined. We report here a case of acute gastroparesis associated with Duchenne's muscular dystrophy. In our case, the patient's symptoms were improved by prokinetic agents and timely decompression in life-threatening acute gastric dilatation.

Active-site mutants of the VanC2 D-alanyl-D-serine ligase, characteristic of one vancomycin-resistant bacterial phenotype, revert towards wild-type D-alanyl-D-alanine ligases

BACKGROUND

The rising number of vancomycin-resistant enterococci (VREs) is a major concern to modern medicine because vancomycin is currently the 'last resort' drug for life-threatening infections. The D-alanyl-D-X ligases (where X is an hydroxy or amino acid) of bacteria catalyze a critical step in bacterial cell-wall peptidoglycan assembly. In bacteria that produce glycopeptide antibiotics and in opportunistic pathogens, including VREs, D-, D-ligases serve as switches that confer antibiotic resistance on the bacteria themselves. Peptidoglycans in vancomycin-sensitive bacteria end in D-alanyl-D-alanine, whereas in vancomycin-resistant bacteria they end in D-alanyl-D-lactate or D-alanyl-D-serine.

RESULTS

We demonstrate that the selective utilization of D-serine by the Enterococcus casseliflavus VanC2 ligase can be altered by mutagenesis of one of two residues identified by homology to the X-ray structure of the Escherichia coli D-alanyl-Dalanine ligase (DdlB). The Arg322-->Met (R322M) and Phe250-->Tyr (F250Y) ligase mutants show a 36-44-fold decrease in the use of D-serine, as well as broadened specificity for utilization of other D-amino acids in place of D-serine. The F250Y R322M double mutant is effectively disabled as a D-alanyl-D-serine ligase and retains 10% of the catalytic activity of wild-type D-alanyl-D-alanine ligases, reflecting a 6,000-fold switch to the D-alanyl-D-alanine peptide. Correspondingly, the Leu282-->Arg mutant of the wild-type E. coli DdlB produced a 560-fold switch towards D-alanyl-D-serine formation.

CONCLUSIONS

Single-residue changes in the active-site regions of D-, D-ligases can cause substantial changes in recognition and activation of hydroxy or amino acids that have consequences for glycopeptide antibiotic efficacy. The observations reported here should provide an approach for combatting antibiotic-resistant bacteria.

Comparative study of bentiromide test and endoscopic retrograde pancreatography in patients with chronic pancreatitis

We performed a bentiromide test in 25 patients with chronic pancreatitis and 7 normal controls to evaluate pancreatic exocrine function, and compared the test results of patients with their endoscopic retrograde pancreatography(ERP) findings. The cumulative 6-hour recovery rate of para-aminobenzoic acid(PABA) in the urine was significantly lower in patients with chronic pancreatitis(55.8 +/- 24.2%) than in controls(82.0 +/- 10.0%). Among 25 patients with chronic pancreatitis, however, 7 patients showed normal recovery rates of PABA. Pancreatograms of the patients represented 4 mild changes, 5 moderate changes, and 16 marked changes. The average 6-hour recovery rates of PABA of the groups were 56.9 +/- 21.6%, 78.4 +/- 10.5%, and 47.2 +/- 23.7%, respectively. Urinary PABA recovery rates were found subnormal as follows: 3(75%) in the mild changes group; 1(20%) in the moderate changes group; and 14(87.5%) in the marked changes group. We found hardly any correlation between the degree of functional impairment and the changes noted by ERP. These findings suggest that both the pancreatic function test and morphologic study are required to evaluate the degree of functional impairment in patients with chronic pancreatitis.

Effect of erythromycin on gastric emptying in healthy individuals assessed by radio-opaque markers and plasma acetaminophen levels

We simultaneously recorded gastric emptying of radio-opaque markers (ROMs) and monitored serial changes in plasma acetaminophen (AAP) levels to demonstrate the relationship between the ROM and the AAP methods, and we investigated the effect of a single intravenous dose of erythromycin (EM) on gastric emptying in healthy human subjects. After an overnight fast, subjects were randomized to receive either placebo or EM lactobionate (Abbott, North Chicago, IL, USA) 250 mg intravenously in a single dose, given immediately before a standard meal. Subjects ingested 1.5 g of AAP and ROMs with the test meal. A supine plain abdominal radiograph was taken 1, 2, 3, and 6 h after ingestion of the test meal. Peripheral blood samples were obtained 0, 0.5, 1, 1.5, 2, 3, and 6 h after ingestion of the test meal. EM significantly accelerated gastric emptying of ROMs. By 6 h, no markers remained in the stomach in any of the subjects in the placebo or EM groups. By 120 min, half of the ROMs had passed into the duodenum in 12.5% of subjects after placebo, whereas EM injection resulted in gastric emptying of half of the ROMs in all subjects. There was no difference in plasma AAP concentration between the placebo and EM groups. There were significant correlations between maximum plasma AAP concentration and gastric emptying of ROMs 120 min after ingestion (r = 0.546; P = 0.019), and between time of maximum plasma AAP concentration and gastric emptying of ROMs 120 min after ingestion (r = -0.568; P = 0.014). The time taken to reach the peak concentrations ranged from 30 to 90 min after ingestion, whereas most ROMs were emptied 120 min after ingestion. We conclude that the gastric emptying assessed by ROMs and by serial changes in plasma AAP level are good, non-invasive, clinically applicable tests, with a significant correlation between the two tests. A single intravenous dose of EM had a prokinetic effect on gastric emptying, assessed by ROMs, in healthy human subjects.

Comparison of the hemostatic effect of endoscopic injection with fibrin glue and hypertonic saline-epinephrine for peptic ulcer bleeding: a prospective randomized trial

BACKGROUND AND STUDY AIMS

Although endoscopic injection therapy using various agents has been considered the least expensive and most effective technique in obtaining hemostasis in peptic ulcer bleeding, most of these agents induce tissue necrosis or degeneration. Theoretically the injection of fibrin glue (FG) to halt peptic ulcer bleeding may be safer than the use of other agents, but randomized clinical trials to compare the efficacy of FG and other agents are rare. The aim of this study was to compare the hemostatic efficacy between FG and hypertonic saline-epinephrine (HSE) in peptic ulcer bleeding.

PATIENTS AND METHODS

From March 1992 to December 1993 we conducted a prospective randomized trial in 127 patients with peptic ulcer bleeding, in whom a visible vessel or active bleeding was identified. Patients were randomized into two groups, an FG group comprising 64 patients who received FG injections, and an HSE group, comprising 63 patients who received HSE injections.

RESULTS

The two groups were comparable with regard to age, sex, bleeding focus and bleeding stigma. Permanent hemostasis using only endoscopic treatment was achieved in 59 cases (92.2 %) in the FG group and in 54 cases (85.7 %) in the HSE group. Rebleeding occurred in seven cases (10.9%) in the FG group and in 14 cases (22.2%) in the HSE group (P=0.087); emergency surgery was undertaken in four (6.3%) and seven cases (11.1%), respectively (P = 0.33); death occurred in one case (1.6%) and four cases (6.3%), respectively (P = 0.165).

CONCLUSIONS

These results suggest that endoscopic injection of FG is an effective method in the control of peptic ulcer bleeding. However, even though there is a strong trend supporting the hypothesis that fibrin glue is superior to HSE, no statistically significant differences are noted. A trial involving larger numbers may produce a positive result.

Bacterial resistance to vancomycin: overproduction, purification, and characterization of VanC2 from Enterococcus casseliflavus as a D-Ala-D-Ser ligase

The VanC phenotype for clinical resistance of enterococci to vancomycin is exhibited by Enterococcus gallinarum and Enterococcus casseliflavus. Based on the detection of the cell precursor UDP-N-acetylmuramic acid pentapeptide intermediate terminating in D-Ala-D-Ser instead of D-Ala-D-Ala, it has been predicted that the VanC ligase would be a D-Ala-D-Ser rather than a D-Ala-D-Ala ligase. Overproduction of the E. casseliflavus ATCC 25788 vanC2 gene in Escherichia coli and its purification to homogeneity allowed demonstration of ATP-dependent D-Ala-D-Ser ligase activity. The kcat/Km2 (Km2 = Km for D-Ser or C-terminal D-Ala) ratio for D-Ala-D-Ser/D-Ala-D-Ala dipeptide formation is 270/0.69 for a 400-fold selection against D-Ala in the C-terminal position. VanC2 also has substantial D-Ala-D-Asn ligase activity (kcat/Km2 = 74 mM-1min-1).

Rare variants of divided right ventricle with sequestered apical trabecular component

The right ventricle may be divided into two or more compartments by various structures in various ways. Rarely, the apical trabecular component may be sequestered from the rest of the right ventricle. We report 4 cases with different underlying lesions that share a common pathology of apical sequestration of the right ventricle resulting in diverse hemodynamic consequences. Case 1 had pulmonary valve stenosis. The apical sequestration of the right ventricle resulted in no significant hemodynamic consequence. Case 2 had multiple defects in the muscular ventricular septum. The volume of left-to-right shunt seemed to be reduced because of the commitment of some of the defects to the sequestered cavity. Case 3 had a large defect in the trabecular septum. As the defect involved the whole septum that was related to the sequestered right ventricular apex, the left ventricle together with the sequestered right ventricle formed a boot-shaped chamber. Hemodynamically, the muscular shelf was an interventricular septum. Case 4 had a coronary artery fistula to an isolated cavity that occupied the apical region of the right ventricle. The pathology was similar to the case that was reported as a five-chambered heart. The abnormal cavity was, in fact, the sequestered right ventricular apex.

A case of bleeding from the Dieulafoy lesion of the jejunum

Dieulafoy lesion is an uncommon cause of gastrointestinal bleeding, reported to be only 2% of acute or chronic upper gastrointestinal bleeding episodes. Bleeding occurs from a small mucosal erosion involving an unusually large submucosal artery in an otherwise normal mucosa. It is associated with massive, life threatening hemorrhage and is difficult to diagnosis. In most cases the lesion is encountered in the proximal stomach, antrum, duodenum, colon and rectum. In particular, extragastric Dieulafoy lesion is an extremely rare source of intestinal bleeding. In Korea, no case of bleeding from a Dieulafoy lesion of the small intestine has been previously reported. We experienced one case of bleeding from a jejunal Dieulafoy lesion, which was confirmed by the pathologic examination of the resected specimen, and report here.

Congenital bronchoesophageal fistula associated with esophageal diverticulum in the adult

Congenital bronchoesophageal fistula is a rare clinical entity in adults. This anomaly may cause various symptoms such as respiratory infections, coughing bouts when eating or drinking, and even hemoptysis. The fistula can cause symptoms in childhood but may not appear until adulthood. We recently experienced a case of congenital bronchoesophageal fistula associated with esophageal diverticulum in an adult. A 63-year-old woman was admitted to our hospital due to chest discomfort, sore throat and coughing bouts when eating. An empyema with lung abscess had occurred eight years previously. Results of the physical examination were unremarkable. A Barium swallowing revealed a medium-sized diverticulum at the right anterior aspect of the esophagus, which had developed a fistulous connection with the right lower lobe bronchus. The patient was treated by fistulectomy and lobectomy of the right lower lobe. The postoperative course was smooth and uneventful.

D-Alanyl-D-lactate and D-alanyl-D-alanine synthesis by D-alanyl-D-alanine ligase from vancomycin-resistant Leuconostoc mesenteroides. Effects of a phenylalanine 261 to tyrosine mutation

The Gram-positive bacterium Leuconostoc mesenteroides, ATCC 8293, is intrinsically resistant to the antibiotic vancomycin. This phenotype correlates with substitution of D-Ala-D-lactate (D-Ala-D-Lac) termini for D-Ala-D-Ala termini in peptidoglycan intermediates in which the depsipeptide has much lower affinity than the dipeptide for vancomycin binding. Overproduction of the L. mesenteroides D-Ala-D-Ala ligase (LmDdl) 2 in E. coli and its purification to approximately 90% homogeneity allow demonstration that the LmDdl2 does have both depsipeptide and dipeptide ligase activity. Recently, we reported that mutation of an active site tyrosine (Tyr), Tyr216, to phenylalanine (Phe) in the E. coli DdlB leads to gain of D-Ala-D-Lac depsipeptide ligase activity in that enzyme. The vancomycin-resistant LmDdl2 has a Phe at the equivalent site, Phe261. To test the prediction that a Tyr residue predicts dipeptide ligase while an Phe residue predicts both depsipeptide and dipeptide ligase activity, the F261Y mutant protein of LmDdl2 was constructed and purified to approximately 90% purity. F216Y LmDdl2 showed complete loss of the ability to couple D-Lac but retained D-Ala-D-Ala dipeptide ligase activity. The Tyr-->Phe substitution on the active site omega-loop in D-Ala-D-Ala ligases is thus a molecular indicator of both the ability to make D-Ala-D-Lac and intrinsic resistance to the vancomycin class of glycopeptide antibiotics.

P53 overexpression in gastric adenocarcinoma with Helicobacter pylori infection

Gastric carcinogenesis has been studied in various aspects. Helicobacter pylori (Hp) infection and mutation of the p53 tumor suppressor gene have recently been argued to be important factors of gastric carcinogenesis. There have been many studies to determine the precise mechanism of how Hp is related to gastric cancer, but it is so far still unknown. We studied the relationship of Hp infection and p53 overexpression and tried to discover some significance in clinicopathologic factors such as age, sex, stage, site, differentiation and gross morphology. Ninety-six patients who were diagnosed with gastric cancer at Severance Hospital, Yonsei University Medical College from November 1995 to March 1996, and 96 control patients of non-ulcer dyspepsia (NUD) were studied by endoscopic biopsy of normal gastric tissue and cancer tissue. They also underwent the CLO (Delta West, Melbourne, Western Australia) test for Hp positivity and p53 immunohistochemical stain for p53 positivity. These data were analyzed for comparison with the clinicopathologic characteristics of gastric cancers. In conclusion, the differentiated group cancer had a significantly high Hp positivity and p53 positivity. There is a possibility that Hp infection and p53 tumor suppressor gene mutation might be significantly related in the gastric carcinogenic process of well- and moderately-differentiated adenocarcinomas, but further study is necessary to determine more direct clues on the carcinogenic roles of these factors.

Extrapancreatic islets of Langerhans: ontogenesis and alterations in diabetic condition

The existence of extrapancreatic islets in the duodenal mucosa of the adult rat has been established by morphological studies and the development of these islets has been followed from the early embryonic stage to neonatal and adult life. Like the pancreatic islets, glucagon cells were the first to appear at day 12 of gestation. However, in contrast to the pancreatic islets, insulin was not detected in the extrapancreatic islets until birth. At this stage, the different endocrine cells assume their classical topography, insulin cells being surrounded by non-insulin endocrine cells. In addition, the behavior of these extrapancreatic islets in diabetic conditions was evaluated on streptozotocin-induced diabetic rats as well as on spontaneous BB Wistar diabetic rats. In both conditions, the extrapancreatic islets were found in the duodenal mucosa but were mainly composed of glucagon cells, the insulin cells having disappeared. These results demonstrate that the extrapancreatic islets are a common normal feature of the rat duodenal mucosa. They appear during fetal development, are present in different strains of rats and behave similarly to the pancreatic islets under spontaneous or chemically induced diabetic conditions. Although their exact role remains to be established, they probably react to local hyperglycaemic environment due to intestinal absorption.