Cell-free DNA Release in the Plasma of Patients with Cardiac Disease is Associated with Cell Death Processes

Cell-free DNA (cfDNA) is released into the plasma of patients with cardiac disease. Here, the source and mechanism of plasma cfDNA release in patients with myocardial infarction (MI) and other cardiac diseases (n = 59) were investigated. Plasma levels of various markers including M30 (apoptosis), M65 (apoptosis and necrosis), cyclophilin A (CyPA) (necrosis), and myeloperoxidase (MPO) (neutrophil activation) were assayed. The plasma cfDNA concentrations in MI and other cardiac diseases were significantly higher than that in the healthy control subjects. Significant differences were not observed among the cardiac disease patients (MI and other cardiac diseases) and healthy control subjects in M30, M65, and CyPA levels. In contrast,the MPO levels were significantly elevated in cardiac disease patients when compared to control groups, and MPO levels in MI patients were significantly higher than other cardiac diseases patients. These results suggest that cfDNA is mainly released by neutrophils via NETosis in addition to apoptosis except for epithelial apoptosis in patients with cardiac disease and the degree is greater in MI patients. The results from this study provide basic information for diagnosis marker of MI.

Urinary Tract Infection Caused by Cronobacter sakazakii

A 69-year-old man presented to the ED of our hospital with fever, loss of appetite, malaise, and pyuria and was admitted. He was diagnosed as having Cronobacter sakazakii urinary infection. We instituted treatment with cefmetazole, and he was discharged on hospital day 7. C. sakazakii is a rare infection in adults in Japan. C. sakazakii urinary infection usually occurs as an opportunistic infection in immunocompromised adults or older adults. This patient was not immunocompromised, so Cronobacter spp. should be recognized as potential pathogens in non-diabetic, non-immunocompromised adults.

Comparison of serum cell-free DNA between postmortem and living samples

Cell-free DNA (cfDNA) originates from apoptotic and/or necrotic cells. Few reports are available that examine cfDNA from postmortem samples. Therefore, this study investigated differences between postmortem and biogenic subjects in concentration and fragment distribution of serum cfDNA. We also clarified features of serum cfDNA in postmortem subjects. The results revealed that postmortem subjects had significantly higher cfDNA concentrations than healthy controls and patients with cardiac disease. Serum cfDNA concentrations increased slightly with postmortem interval in subjects who died of asphyxia, and they were slightly higher in subjects who died from internal vs. external causes. Microchip electrophoresis of serum cfDNA revealed a fragment larger than 10,000 bp in only two postmortem subjects; we speculate that the fragment may have originated from necrotic cells. A relatively high concentration of one 150-200 bp fragment was characteristic of postmortem samples. This fragment may have been derived from apoptosis or other processes. We also observed ladder fragments in some subjects who died from external causes. Although additional research is needed for verification, serum cfDNA concentrations and fragment patterns possibly be used as a tool to estimate postmortem intervals and cause of death.

Circulating cell-free DNA fragment analysis by microchip electrophoresis and its relationship with DNase I in cardiac diseases

Circulating cell-free DNA (cfDNA) has been directly related to cancer, diabetes, stroke, systemic lupus erythematosus, trauma, rheumatoid arthritis, inflammation, infection, and myocardial infarction (MI). In this study, plasma cfDNA was extracted from the plasma of cardiac disease patients and the cfDNA fragment distribution as well as the relationships between cfDNA concentration and deoxyribonuclease I (DNase I) activity enzyme implicated in double-stranded DNA processing were examined. Results revealed that the cfDNA concentrations in patients with MI and cardiac angina were significantly higher than that in healthy control subjects. Microchip electrophoresis of plasma cfDNA revealed a single fragment (150-200 bp) in some healthy control subjects and three fragments (150-200 bp, 300-400 bp, and 500-600 bp) in all cardiac patient samples. Moreover, a cfDNA ratio of 150-200 bp/500-600 bp was significantly more prevalent in MI patients than in patients with other cardiac diseases (chest pain, cardiac angina, atrial fibrillation and cardiac failure). In addition, a positive correlation between DNase I activity and cfDNA concentration was observed. These results suggest that the plasma cfDNA in cardiac disease patients may originate from apoptosis and that the 150-200 bp/500-600 bp ratio for cfDNA may be a novel diagnostic indicator for MI.

Low genetic heterogeneity of copy number variations (CNVs) in the genes encoding the human deoxyribonucleases 1-like 3 and II potentially relevant to autoimmunity

Deoxyribonucleases (DNases) might play a role in prevention of autoimmune conditions such as systemic lupus erythematosus through clearance of cell debris resulting from apoptosis and/or necrosis. Previous studies have suggested that variations in the in vivo activities of DNases I-like 3(1L3) and II have an impact on autoimmune-related conditions. The genes for these DNases are known to show copy number variations (CNVs) whereby copy loss leads to a reduction of the in vivo activities of the enzymes, thereby possibly affecting the pathophysiological background of autoimmune diseases. Using a simple newly developed quantitative real-time PCR method, we investigated the distributions of the CNVs for DNASE1L3 and DNASE2 in Japanese and German populations. It was found that only 2 diploid copy numbers for all of these DNASE CNVs was distributed in both of the study populations; no copy loss or gain was evident for any of the autoimmune-related DNase genes. Therefore, it was demonstrated that these human autoimmune-related DNase genes show low genetic diversity of CNVs resulting in alterations of the in vivo levels of DNase activity.

The value of CT findings for prognostic prediction of spontaneous superior mesenteric artery dissection

BACKGROUND

Spontaneous superior mesenteric artery (SMA) dissection is rare cause of acute abdomen. Time-dependent change of SMA dissection has not been established.

PURPOSE

To determine Sakamoto classification (SC) type of acute and chronic SMA dissection (aSMAD and cSMAD) to predict the treatment methods and outcome.

MATERIAL AND METHODS

From April 2003 to March 2017, unenhanced and contrast-enhanced CT were used to diagnose acute symptomatic or chronic asymptomatic SMA dissection in 25 consecutive patients without aortic dissection. Correlations between SCs and treatment methods and outcomes were investigated.

RESULTS

All 13 patients with aSMAD initially received conservative treatment. Initial SCs in aSMAD were type I = 1, type III = 9, and type IV = 3. Three of nine initial type III and two of three initial type IV changed to type I at follow-up. One of nine type III changed to type II at follow-up. Ohers did not change. One with initial type III required vascular repair, so the final SC was not available. Three patients required bowel resection. In cSMAD of 12 patients, the initial/final SC were type I and IV in ten and two patients, respectively, without change during follow-up. cSMAD was significantly older than aSMAD. The initial length of dissection of aSMAD was longer than in the cSMAD group. In aSMAD, the final length of dissection was significantly shorter than in the initial computed tomography scan.

CONCLUSION

Initial SC differed significantly between aSMAD and cSMAD. Initial SC types in aSMAD were type III and IV mainly, and changed during the observation period. In cSMAD, SC types were I and IV without change.

Graft-versus-host disease-Induced esophageal web

Endoscopy revealed a chicken meat impaction in the upper esophagus. On food removal, an esophageal web (thin membranous constriction) was revealed at the site and diagnosed as GVHD-induced esophageal web by the endoscopist.

Hemosuccus pancreaticus successful treatment by double balloon-assisted coil embolization for active bleeding from the main trunk of the superior mesenteric artery

We report a case of a 63-year-old man with hemosuccus pancreaticus due to large pseudoaneurysm originating from the main trunk of the superior mesenteric artery (SMA). The patient was treated successfully with the double balloon-assisted coil embolization technique combined with proximal and distal balloon inflation in the short segment of the SMA. This technique preserved the pancreaticoduodenal arterial arcade and the supply to the distal part of the SMA by embolizing SMA in a short segment.

Association of SNPs in genes encoding zinc transporters on blood zinc levels in humans

Zinc homeostasis in cells depends on zinc transporters, which are divided into 2 families: ZnT (SLC30A) and ZIP (SLC39A). In this study, we examined the effect of 20 single nucleotide polymorphisms (SNPs) in 10 genes encoding zinc transporters on blood zinc concentration in Japanese subjects (n = 102). Blood zinc levels were determined by microwave plasma-atomic emission spectrometry, and SNPs were analyzed by polymerase chain reaction followed by restriction fragment length polymorphism analysis. Among the 20 SNPs examined, 3 SNPs (SLC30A3 rs11126936, SLC39A8 rs233804, and SLC39A14 rs4872479) were significantly associated with blood zinc concentration. Individuals with genotype TT and TG in rs11126936 showed significantly higher blood zinc concentrations than those with GG. As for rs233804, individuals harboring the A allele had significantly higher blood zinc concentrations than those without this allele. Furthermore, the genotype TT and TG in rs4872479 had significantly higher blood zinc concentrations than those with GG. Among these three SNPs, combination of SLC30A3 rs11126936 and SLC39A8 rs233804 may strongly affect blood zinc levels. This study is the first comprehensive investigation of the effect of SNPs in genes encoding zinc transporters on blood zinc concentration. Adverse effects of zinc deficiency are reported and above 3 SNPs may be related to genetic susceptibility to zinc deficiency.

Nonfatal air embolism complicating percutaneous CT-guided lung biopsy and VATS marking: Four cases from a single institution

Systemic air emboli occur as a rare complication of percutaneous needle biopsy of the lung and video-assisted thoracoscopic surgery (VATS) marking. Here we present four cases of systemic air emboli from single institution and the imaging findings and embolism' kinetics using contrast-enhanced media during VATS color marking with indocyanine green. We suggest that early detection using routine whole-lung CT is required for asymptomatic patients with abnormal air. If abnormal air is found, we should keep the patient to the appropriate posture in order to prevent moving the air until it dissipates. Early detection of abnormal air can prevent severe complications.

An autopsy case of spontaneous esophageal perforation (Boerhaave syndrome)

A 45-year-old male, an alcohol addict with asthma, was found dead in his home, after several days of continued drinking. A forensic autopsy was performed 3days after the discovery of his death in order to specify the cause of death. A longitudinal perforation penetrating all layers of the esophagus measuring 1.8cm was present on the left wall approximately 2.0cm from the gastroesophageal junction. There were 1900mL of greenish to brownish turbid liquid in the left pleural cavity and 150mL of greenish viscous liquid in the stomach. Histopathologically, an infiltration of numerous neutrophils was evident in the submucosa layer, proper muscular layer, and serous membrane of the esophagus, corresponding to the esophageal laceration. The serum C-reactive protein (CRP) concentration was determined to be 3.1mg/dL. The alcohol concentrations were determined to be 1.49mg/g in the right cardiac blood, 1.31mg/g in the left cardiac blood, and 2.48mg/g in urine. Based upon the autopsy and histopathological findings, as well as the biochemical and toxicological analyses, we concluded that the cause of death was respiratory failure by pleural effusion, resulting from spontaneous esophageal perforation. This was the first report of a spontaneous esophageal perforation eventually causing respiratory failure.

Ambulance dispatches to schools during a 5-year period in Fukui Prefecture

Aim

To determine the characteristics and trends of medical emergencies during school activities by analyzing information provided by fire departments.

Methods

During a 5‐year period from January 2009 to December 2013, all nine fire departments in Fukui Prefecture handled 850 emergencies at schools. We investigated the 850 cases with the age range of 0–63 years.

Results

It was found that 21.5% of ambulance dispatches to schools were on weekends and there were more dispatches for non‐faculty members of all age groups on weekends than on weekdays. The percentage of weekend dispatches was particularly high for students aged ≥19 years. Emergency calls for junior high school students and younger students accounted for the majority of weekday calls. There were a total of 524 ambulance dispatches for the three categories “sprains, contusions, dislocations, and fractures” (n = 245), “seizures, epilepsy, and syncope” (n = 171), and “cuts, bruises, lacerations, trauma, amputations, and burns” (n = 108), with dispatches for these three categories accounting for 61.6% of all dispatches. Almost all dispatches for “heat stroke and dehydration” were during school hours and were concentrated between the months of July and September. Heat stroke was most common among high school students and most often occurred during the summer/fall season and on weekends.

Conclusion

Heat stroke was the fourth most frequent condition that required an ambulance dispatch after the above three conditions. Heat stroke is predictable, indicating that it is necessary to prevent heat stroke during high school club activities.

[Tracheal Intubation by Paramedics in a Local Community: Current Situation and Future Challenges]

BACKGROUND

As of April 2013, 164 paramedics are certified to perform tracheal intubation in Fukui Prefecture. This study investigated the current situation surrounding tracheal intubation performed by paramedics in prehospital care.

METHODS

Subjects were 58 paramedics who completed practical training at our hospital. Post-training duration, number of tracheal intubation cases, number of attempts before successful tracheal intubation, disease involved, rate of return of spontaneous circulation, and prognosis were examined.

RESULTS

Tracheal intubation was successful on the first attempt in 92% of cases. Rate of return of spontaneous circulation was high in paramedics whose post-training duration was short. No return of spontaneous circulation occurred after a second attempt. Four patients survived asphyxia or aspiration.

CONCLUSIONS

It is important to perform successful tracheal intubation on the first attempt, to recognize the probability of successful resuscitation in patients with exogenous disease, and to strengthen the medical control system.

[Comatose patient with neuroleptic malignant syndrome brought by ambulance]

A 27-year-old woman with schizophrenia showed signs of neuroleptic malignant syndrome with disturbed consciousness, high fever, muscle rigidity, and autonomic dysfunction (including tachycardia and enhancement of saliva secretion). Since the age of 15, she had been treated at a local psychiatric clinic with a diagnosis of schizophrenia. On the day she was brought to the emergency room, she was asleep in the morning, but tachycardia was observed in the evening in the absence of consciousness. The patient was brought to our hospital by ambulance. It was revealed that she had taken a massive dose of chlorpromazine hydrochloride in the morning on the same day. On arrival, the Japan coma scale, pulse, respiratory rate, body temperature, and Sp(O2) were 300, 114 beats x min(-1), 26 breaths x min(-1), 39.0 degrees, and 91% (room air), respectively. The CPK level was 1,776 IU x l(-1). Sp(O2), bilateral pneumonia, and right atelectasis improved 2 hours after admission. Endotracheal intubation was performed for artificial respiration. Salivation, marked sweating, and rigidity of the limbs were noted. Under a diagnosis of neuroleptic malignant syndrome, dantrolene was administered. For pneumonia, ceftriaxone and pazufloxacin were administered. The consciousness became clear 2 days after admission. The patient was discharged 10 days after admission.

Evaluation of effectiveness of stellate ganglion block (SGB) treatment of sudden hearing loss

CONCLUSION

A stellate ganglion block (SGB) based on the goal of improving internal ear circulatory disturbance appears to be beneficial for the treatment of sudden hearing loss.

OBJECTIVES

To evaluate the effectiveness of SGB for sudden hearing loss.

METHODS

This retrospective study reviewed the medical records of 49 patients who received SGBs and 496 patients who received only conservative therapy, primarily with systemic steroids, for treatment of sudden hearing loss. Propensity scores were used in pairwise matching of these patients to avoid selection biases between the two treatment modalities.

RESULTS

Propensity score matching yielded 48 pairs. The mean therapeutic effect of the SGB was calculated to be 0.40 ± 0.20 (mean ± standard error, p = 0.051).

[Usefulness of helmet type mask in the treatment of postoperative atelectasis in a child: a case report]

A 7-year-old autistic girl underwent an appendectomy under general anesthesia. Both intraoperative course and postoperative one following extubation were uneventful;however, she suddenly developed severe hypoxemia caused by massive atelectasis in the right and lower lobes 27 hours after the operation. With a helmet type mask on her face, she was successfully managed with continuous positive airway pressure (noninvasive positive pressure ventilation) mode, in which PEEP level was 5 cmH2O and FI(O2) was 0.38. Compared with the face mask type, the helmet type has the advantage of better stability on the face without losing sight, and less discomfort with fixation. In spite of a slight difficulty in setting up the device and noise to the patient, the helmet type mask seems to be more useful in the treatment of respiratory distress in pediatric patients.

[Two cases of cerebral infarction caused by fat embolism during orthopedic bone surgeries]

I report on two cases of cerebral infarction caused by fat embolism during the orthopedic surgeries. The first patient was a 77-year-old woman with a femur neck fracture, who developed coma after orthopedic operation. The other was a 70-year-old woman with open fractures in the femur and the fibula, who developed hemiplegia after operation. By echogram, no embolus was demonstrated in the heart, in the carotid arteries or in deep veins, also paradoxical cerebral infarction was denied in the both cases. Diffusion-weighted MR image and FLAIR MR image showing multiple hyperintense signals in the hemispheres were very useful as a diagnosing modality in acute stage. The patients gradually recovered with the intensive treatment.

[Case of serious lidocaine intoxication]

Lidocaine is frequently used as a local anesthetic and has very low incidence of serious complications. I report on a case of lidocaine intoxication in a 66-year-old man who presented with seizure and cardiac periarrest following the brachial plexus block with 450 mg of lidocaine. Twelve minutes after the lidocaine administration, he became unconscious and 29 minutes after, developed seizure. Bradycardia and subsequent cardiovascular depression were found 74 minutes after the lidocaine block. The patient was successfully treated with diazepam, atropine sulphate and transcutaneous pacing for each symptom, respectively.

Preparation and antimicrobial activity of micacocidin

Micacocidin (3), a Zn-free derivative of micacocidin A (1), was prepared to evaluate its antimicrobial activity in comparison with 1 and to obtain a starting material for chemical modification of 1. The structure of 3, quite unlike those of any previously known antimicrobial agents, was elucidated by 1-D and 2-D homonuclear and heteronuclear NMR and mass spectroscopy. Micacocidin (3) thus prepared exhibited weak or no antibacterial activity except against Mycoplasma species, i.e. 3 showed stronger activity than 1. It is noteworthy that 3 displayed high activity against fungi such as Candida, Aspergillus and Trichophyton species.

Effects of YF476, a potent and selective gastrin/cholecystokinin-B receptor antagonist, on gastric acid secretion in beagle dogs with gastric fistula

The antisecretory effects of the gastrin/cholecystokinin-B (CCK-B) receptor antagonist YF476 ((R)-1-[2,3-dihydro-2-oxo-1-pivaloylmethyl-5-(2'-pyridyl) 1H-1,4-benzodiazepin-3-yl]-3-(3-methylaminophenyl)-urea, CAS 155488-25-8) on secretagogue- and peptone-induced gastric acid secretion in beagle dogs with chronic gastric fistula were examined. Plasma gastrin concentrations were evaluated following introduction of peptone into the stomach. Intravenous administration of YF476 dose-dependently inhibited pentagastrin (1 microgram/kg/h)-induced gastric acid secretion, with an ED50 value of 0.0023 mumol/kg. In contrast, intravenous administration of YF476 (0.3 mumol/kg) did not affect histamine (15 micrograms/kg/ h)-induced gastric acid secretion. Oral administration of YF476, famotidine and omeprazole dose-dependently inhibited peptone (8%, 200 ml)-induced gastric acid secretion with ED50 values of 0.11, 0.76 and 4.28 mumol/kg, respectively. The antisecretory effect of YF476 was about 7 and 40 times more potent than that of famotidine and omeprazole, respectively. Plasma gastrin concentrations were increased by introduction of peptone. These results suggest that YF476 is an extremely potent and selective antisecretory drug and the endogenous gastrin plays an important role in peptone-induced gastric acid secretion in dogs.

YM022, a potent and selective gastrin/CCK-B receptor antagonist, inhibits peptone meal-induced gastric acid secretion in Heidenhain pouch dogs

We examined the affinity of YM022, a potent and selective gastrin/CCK-B receptor antagonist, for canine gastrin/CCK-B and CCK-A receptors and the effects of YM022 on secretagogue- and peptone meal-induced acid secretion in the denervated, surgically separated (Heidenhain) canine gastric pouch model in comparison with those of famotidine, an H2-receptor antagonist, and atropine. YM022 inhibited the binding of [(125)I]CCK-8 and [(3)H]devazepide to canine gastrin/CCK-B and CCK-A receptors, with IC50 values of 0.73 and 136 nM, respectively. Intravenous YM022 dose-dependently inhibited pentagastrin- and peptone meal-induced acid secretion with ED50 values of 0.0261 and 0.0654 micromol/kg, respectively, without affecting histamine- or methacholine-induced acid secretion. Famotidine inhibited acid secretion induced by all stimulants, while atropine inhibited the acid secretion induced by every stimulant except histamine. These results indicated that YM022 is a highly potent and selective antagonist for the canine gastrin/CCK-B receptor and suppressed pentagastrin- and peptone meal-induced gastric acid secretion without affecting histamine- or methacholine-induced acid secretion in Heidenhain pouch dogs.

YF476 is a new potent and selective gastrin/cholecystokinin-B receptor antagonist in vitro and in vivo

BACKGROUND

We newly synthesized YF476 ((R)-1-[2,3-dihydro-2-oxo-1-pivaloylmethyl-5-(2'-pyridyl)-1H-1, 4benzodiazepin-3-yl]-3-(3-methylamino-phenyl)urea) as a gastrin/cholecystokinin-B (CCK-B) receptor antagonist. We investigated the pharmacological profile of YF476 in vitro and in vivo.

METHODS

We examined the binding properties of YF476 to the rat brain, cloned canine and cloned human gastrin/CCK-B receptors, and the effect of YF476 on secretagogue-induced gastric acid secretion in rats and Heidenhain pouch dogs.

RESULTS

YF476 replaced the specific binding of [125I]CCK-8 to the rat brain, cloned canine and cloned human gastrin/CCK-B receptors, with Ki values of 0.068, 0.62 and 0.19 nM, respectively. The affinity of YF476 for rat brain gastrin/CCK-B receptor was 4100-fold higher than that for rat pancreatic CCK-A receptor. In anaesthetized rats, intravenous YF476 inhibited pentagastrin-induced acid secretion with an ED50 value of 0.0086 micromol/kg, but did not affect histamine- and bethanechol-induced acid secretion at a dose of 10 micromol/kg. In Heidenhain pouch dogs, intravenous and oral YF476 inhibited pentagastrin-stimulated gastric acid secretion in a dose-dependent manner with ED50 values of 0.018 and 0.020 micromol/kg, respectively, but did not affect histamine-induced acid secretion.

CONCLUSION

These results suggest that YF476 is an extremely potent and highly selective gastrin/CCK-B receptor antagonist, and that the gastrin/CCK-B receptor is not involved in histamine- or bethanechol-induced gastric acid secretion in dogs or rats.

Mucosal protective effect of leminoprazole on reflux esophagitis induced in rats

We examined the effect of leminoprazole (an acid pump inhibitor) on reflux esophagitis induced in rats. Intragastrically administered leminoprazole significantly and dose-dependently protected the esophageal mucosa against the reflux of gastric contents, without affecting gastric acid secretion. However, it had no effect on the esophagitis when administered intraduodenally, despite its significant inhibition (about 40%) of gastric acid secretion. Omeprazole significantly prevented the development of esophagitis, most probably through potent inhibition of gastric acid secretion. Indomethacin significantly reduced the synthesis of prostaglandin E2 in the esophagus. Since indomethacin pretreatment had no effect on the esophageal protection by leminoprazole, omeprazole or sucralfate, the involvement of endogenous prostaglandins can be ruled out as a possible underlying mechanism. Intragastrically, but not intraduodenally, administered sucralfate significantly prevented the esophagitis even at a dose not affecting gastric acid secretion. These results strongly suggest that both leminoprazole and sucralfate protect the esophageal mucosa directly.

Gastrin receptor antagonist YM022 prevents hypersecretion after long-term acid suppression

Female rats were treated orally for 13 wk with YM022 (300 mumol.kg-1.day-1) and with omeprazole (400 mumol.kg-1.day-1) or famotidine (900 mumol.kg-1.day-1) with or without YM022. At 2 h after the last dose, YM022 and omeprazole markedly inhibited basal and pentagastrin-induced acid secretion. Famotidine was less potent than YM022 and omeprazole against both secretions. The degree of increase in plasma gastrin level in the three groups was parallel to the antisecretory potencies of the drugs. At 14 days after the cessation of omeprazole treatment, the secretory response to pentagastrin increased above that of the control. This hyperresponse lasted for > or = 56 days. In the famotidine-treated group, a small increase in secretory response to pentagastrin was observed but was not statistically significant. The increase in secretory response to pentagastrin was paralleled by an increase in mucosal cell mass. In contrast, YM022 not only exhibited a long-lasting inhibition of pentagastrin-induced acid secretion but also prevented the hyperresponse to pentagastrin caused by omeprazole. These results indicate that the hypergastrinemia caused by long-term administration of antisecretory drugs increases mucosal secretory response to pentagastrin through a gastrin/cholecystokinin B receptor-mediated pathway in rats.

YM022 [(R)-1-[2,3-dihydro-1-(2'-methylphenacyl)-2-oxo-5-phenyl- 1H-1,4-benzodiazepin-3-yl]-3-(3-methylphenyl)urea], a potent and selective gastrin/cholecystokinin-B receptor antagonist, prevents gastric and duodenal lesions in rats

We evaluated the effect of YM022 [(R)-1-[2,3-dihydro-1-(2'- methylphenacyl)-2-oxo-5-phenyl-1H-1,4-benzodiazepin-3-yl]-3- (3-methylphenyl)urea], a potent and selective gastrin/cholecystokinin-B receptor antagonist, on gastric acid secretion and gastric and duodenal lesions in rats. Oral YM022 (0.1-10 mumol/kg), famotidine (0.3-30 mumol/kg) and omeprazole (3-100 mumol/kg) dose-dependently suppressed acid secretion in pylorusligated rats with ED50 values of 0.83, 1.63 and 10.9 mumol/kg, respectively. YM022 (1-10 mumol/kg p.o.), famotidine (1-10 mumol/kg p.o.) and omeprazole (10-100 mumol/kg p.o.) prevented indomethacin-induced gastric lesions in a dose-related manner. The potency of YM022 was comparable to that of famotidine and was 8 times greater than that of omeprazole. YM022 and famotidine partially inhibited gastric damage induced by water-immersion and restraint stress, whereas omeprazole abolished these lesions. In an acidified ethanol-induced gastric injury model, all three drugs inhibited the formation of erosions. The YM022 dosage required in this model was much greater than that required in the inhibition of gastric acid. The inhibitory effect of YM022 was partially reversed by indomethacin, indicating the involvement of a prostaglandin-mediated pathway. YM022 (3-100 mumol/kg p.o.), famotidine (1-30 mumol/kg p.o.) and omeprazole (3-100 mumol/kg p.o.) inhibited mepirizole-induced duodenal ulcers. On the basis of ED50 values, YM022 was 5 times less potent than famotidine and as potent as omeprazole against mepirizole-induced duodenal ulcers. These results suggest that YM022 possesses antisecretory and antiulcer activities that are as potent as those of famotidine in rats and that YM022 represents a useful therapeutic agent in the treatment of peptic ulcer disease.

Effects of IGN-2098, a new histamine H2-receptor antagonist, on gastric secretion and gastric and duodenal lesions induced in rats. Comparison with roxatidine

A new compound, IGN-2098 [5,6-dimethyl-2-[4-<3-(1-piperidinomethyl) phenoxy>cis-butenylamino]-4-(1H)-pyrimidone.2HCl], was found to be a potential histamine H2-receptor antagonist in the guinea pig atrium. IGN-2098, given p.o., significantly and persistently (for more than 12 hr) inhibited the basal gastric secretion in pylorus-ligated rats. The agent also significantly inhibited the basal gastric secretion when given by the s.c.-, i.d.- or i.p.-route. Stimulated gastric secretion in fistula rats in response to histamine, carbachol or pentagastrin was also significantly inhibited with IGN-2098 given s.c. Pretreatment with IGN-2098 (p.o.) significantly protected the gastric mucosa against pylorus ligation-, water-immersion stress-, histamine-, indomethacin-, HCl.aspirin-, and HCl.ethanol-induced gastric lesions. In addition, the agent significantly protected the duodenal mucosa against mepirizole-induced ulcers. Based upon the ED50 values, the antisecretory effects on histamine, carbachol or pentagastrin-stimulated acid secretion were 6.0, 37.0 or 80 times more potent than roxatidine, respectively. As to the anti-lesion effects on HCl.aspirin-induced gastric lesions or mepirizole-induced duodenal ulcers, IGN-2098 was 8.1 or 14.8 times more potent than roxatidine, respectively. These results suggest that IGN-2098 will be a useful drug for the treatment of gastric and duodenal lesions in man.

Stimulation by prostaglandin E2 of alkaline secretion in the rat duodenum: comparative study with hypertonic NaCl

Possible involvement of increased mucosal permeability in the stimulation by prostaglandin E2 (PGE2) of duodenal HCO3- secretion was investigated in rats. PGE2 (0.3, 1 mg/kg, s.c.) dose-dependently increased HCO3- secretion in the duodenum with a significant elevation of transmucosal potential difference (PD); the PD was increased from -4.5 +/- 0.3 mV to -10.0 +/- 1.5 mV (mucosa negative) at 1 mg/kg. These responses caused by PGE2 were abolished by sacrificing the animals with saturated KCl (i.v.). Although a significant increase of HCO3- output was observed after exposure of the mucosa to 1 M NaCl (0.5 ml), this response was accompanied by a significant reduction of PD and was not abolished after KCl injection. The mucosal permeability determined by Evans blue (1%, i.v.) was not affected by PGE2, while 1 M NaCl markedly elevated the amount of extravasated dye in both the luminal content and the mucosa. Stimulation of HCO3- output by PGE2 was significantly mitigated by ouabain (3 mg/kg, s.c.) or prior exposure of the mucosa to 1 M NaCl. These results suggest that stimulation by PGE2 of duodenal HCO3- secretion is not simply due to the increased mucosal permeability, but depends rather on both the Na/K ATPase activity and the intact perfusion of the organ. The HCO3- response as induced by 1 M NaCl may result from the increased permeability and is accompanied by a marked reduction of PD.

Effects of TY-10957, a stable PGI2 derivative, on gastroduodenal lesions and secretory responses in the rat

The effects of TY-10957, a stable PGI2 derivative, on gastroduodenal lesions and secretory responses were examined in rats and compared with those of ornoprostil, a PGE1 derivative. Orally administered TY-10957 dose dependently prevented gastric lesions induced by ethanol/HC1 (60% ethanol in 150 mM HCl) and duodenal ulcers induced by mepirizole (200 mg/kg); a significant effect was obtained at 3 micrograms/kg or greater in the former and at 300 micrograms/kg in the latter. Intraduodenally administered TY-10957 had minimal effects on gastric acid secretion, and at the highest dose (300 micrograms/kg) both the basal acid output and that stimulated by histamine (20 mg/kg) were significantly reduced by about 40%. TY-10957 (30-300 micrograms/kg s.c.) produced a marked increase of alkaline secretion in both stomach and duodenum of anesthetized rats, and these effects were significant at 30 micrograms/kg in the stomach and at 100 micrograms/kg in the duodenum. On the other hand, ornoprostil produced a potent and significant inhibition against ethanol/HCl-induced lesions (greater than 1 microgram/kg), but had no effect on mepirizole-induced duodenal ulcers. This PGE1 derivative had no influence on both basal and stimulated acid secretion and did not significantly affect alkaline secretion even at 100 micrograms/kg. These results suggest that TY-10957 has a protective action on both gastric and duodenal mucosa. The mechanism of duodenal antiulcer effect may involve both inhibition of acid and stimulation of alkaline secretion, while the gastroprotective action of this agent may be attributed to other factors.