Self-compassion and related factors in severe mental illness: A scoping review

PURPOSE

To clarify what is known and identify research gaps on the role of self-compassion (SC) and potential interventions for individuals with severe mental illness (SMI).

DESIGN AND METHODS

We analyzed 24 studies of SC in schizophrenia spectrum disorder, bipolar disorder (BD), and major depressive disorder (MDD).

FINDINGS

Mindfulness-based cognitive therapy (MBCT) was the most common intervention. Predicting depression by SC was common in MDD and BD; however, relationships between demographics/clinical variables and SC in BD and schizophrenia spectrum disorder remain unclear.

PRACTICE IMPLICATIONS

MBCT increases SC in SMI. Data regarding predictors of SC are limited, especially in schizophrenia.

Effects of mild-intensity physical exercise on neurocognition in inpatients with schizophrenia: A pilot randomized controlled trial

PURPOSE

To find suggestions for a future definitive randomized control trial and examine the effects of physical exercise on neurocognition in schizophrenia.

DESIGN AND METHODS

Patients hospitalized with schizophrenia were randomly assigned to exercise (n = 5) or control (n = 17) groups. The experimental group performed an exercise regimen for 8 weeks. Following intervention, demographics, psychiatric symptoms, and neurocognitive functions were examined.

FINDINGS

The patients in the control and exercise groups, 14 and 4, respectively, showed significant differences in hospitalization duration and negative symptoms. After controlling both, neurocognition improved in the exercise group compared with the control group.

PRACTICE IMPLICATIONS

Mild-intensity physical exercise improves global neurocognition in schizophrenic inpatients and could lead to earlier release.

The effect of revised process recording on self-focus and self-compassion: A randomized controlled pilot study

DESIGN AND METHODS

Thirty-five university nursing students in Japan participated in this randomized controlled trial. The revised process recording referred to self-compassion. Both the control and intervention groups completed the self-compassion scale (SCS) pre- and post-intervention. A repeated two-way analysis of variance examined the interaction effect of time × group on the SCS subscales.

FINDINGS

A significant interaction effect was observed only for mindfulness; the score only increased in the intervention group.

IMPLICATIONS FOR NURSING PRACTICE

The revised process recording might facilitate self-compassion, making it appropriate for nursing education.

Self-compassion and nursing competency among Japanese psychiatric nurses

PURPOSE

This study examined the association of self-focus and self-compassion with nursing competency.

DESIGN AND METHODS

Data of 433 psychiatric nurses comprising demographics, other-consciousness, self-compassion, self-focus, and nursing competency were analyzed using the Other-Consciousness Scale (OCS), Self-Compassion Scale (SCS), Japanese version of the Rumination-Reflection Questionnaire (RRQ), and Oriented Problem Solving Behavior (OPSN).

FINDINGS

Higher internal aspect and lower fantastic aspect in OCS, higher reflection in RRQ, and lower SCS negative subscales predicted a higher OPSN score. The account rate of variance was 12.5%.

PRACTICE IMPLICATIONS

Psychiatric nursing education should facilitate other-consciousness and reflection enhancement, and assuage uncompassionate attitude towards self.

Effects of self-compassion and self-focus on sleep disturbances among psychiatric nurses

PURPOSE

Previous research has demonstrated that self-compassion improved sleep in geriatric samples. However, this may be due to an uncontrolled influence from self-focus, or interaction between self-compassion and self-focus. This study examines whether these findings apply to psychiatric nurses.

DESIGN AND METHODS

Demographics, sleep disturbances, self-compassion, and self-focus of 404 psychiatric nurses were assessed. Hierarchical multiple regression was used to predict sleep disturbances.

FINDINGS

Analyzes revealed that working more night shifts, less self-compassion, and rumination predicted worse sleep quality; however, the effect of self-compassion was not significant when controlling for self-focus.

PRACTICE IMPLICATIONS

An association between sleep quality and self-compassion was observed, but not when controlling for self-focus. Rumination may have an impact on sleep, and reducing it may improve sleep in psychiatric nurses.

Effect of process recording and self-compassion on self-focus: A pre-post interventional pilot study

Research Problem/aim: This study examined whether process recording increases self-focus, and whether this effect is moderated by self-compassion. Methods: Participants included 31 undergraduates in Tokyo. A pre-post-test design was used. Participants completed measures including self-focus and self-compassion before and after process recording. Participants were divided into high and low self-compassion groups. Findings: Overall, the mean rumination and reflection scores were 42.0 and 37.9, respectively, at pre-intervention. The low self-compassion group (n = 14) showed no significant changes in either subscale. The high self-compassion group (n = 17) showed a significant reduction in rumination. Conclusions: Overall, process recording does not influence self-focus, but does reduce rumination in those with high self-compassion. Enhancing self-compassion is needed before using process recording to prevent excessive rumination.

Comparison of factors predicting nursing skills between general and psychiatric nurses

PURPOSE

I examined whether nursing skills are related to occupational stress, self-focus, and other-consciousness, and whether these relationships differ between general and psychiatric nurses.

DESIGN AND METHODS

Two hundred seventy-one general and 317 psychiatric nurses completed a questionnaire assessing the aforementioned variables. Regression analysis was used to explore the predictors of nursing skills.

FINDINGS

Internal and fantastic aspects (other-consciousness subscales) and psychological burden (occupational stress subscale) predicted nursing skills in both groups, while lower rumination and higher reflection scores predicted them only in psychiatric nurses.

PRACTICE IMPLICATIONS

Nursing education should facilitate other-consciousness in general nurses, but self-focus in psychiatric nurses.

Neurocognitive differences between inpatients and outpatients with symptomatically nonremitted schizophrenia: A cross-sectional study

PURPOSE

We aimed to examine whether neurocognition in individuals with nonremitted schizophrenia differed between inpatients and outpatients.

DESIGN AND METHODS

We recruited 59 inpatients and 41 patients with nonremitted schizophrenia (assessed with the Andreason criteria), and neurocognitive functions were compared between both, controlling for demographics, psychiatric symptoms.

FINDINGS

Outpatients with nonremitted schizophrenia performed better on tests of processing speed, visual attention, and working memory than did inpatients with nonremitted.

PRACTICE IMPLICATIONS

To facilitate discharge for nonremitted inpatients, nursing could focus on processing speed, e.g., arranging the environment such that patients do not need quick responses.

Does Physical Exercise Increase Brain-Derived Neurotrophic Factor in Major Depressive Disorder? A Meta-Analysis

BACKGROUND

Major depressive disorder (MDD) is one of the most common disorders in the world, but is generally refractory to antidepressant treatment. However, physical exercise has been demonstrated to improve MDD symptoms, though the mechanism through which this is achieved is not clear. This systematic review and meta-analysis aimed to clarify whether physical exercise increased brain-derived neurotrophic factor (BDNF) in patients with MDD to either establish or rule out this effect as a possible mechanism.

SUBJECTS AND METHODS

We searched five electronic databases (PubMed, PsycINFO, CHINAL, Cochran Library, and Japanese Central Review of Medicine) for interventional studies released prior to 24 October 2017, examining the effects of physical exercise on BDNF in patients with MDD that compared the experimental group with an MDD control group. Those studies meeting the inclusion criteria were subjected to a meta-analysis in which changes of BDNF from baseline to post-exercise were quantified, with a standard mean difference and random effect model.

RESULTS

Five studies were eligible and included 199 participants. All articles included subjects with severe symptoms; three articles studied inpatient populations. All articles introduced aerobic exercise. We found no significant effect of physical exercise on BDNF levels (Z=0.32, p=0.75), and no heterogeneity (I²=0%). The risk of bias was moderate.

CONCLUSIONS

We conclude that physical exercise does not significantly increase BDNF in patients with MDD. Thus, while increased BDNF has been shown to be beneficial in patients with MDD, physical exercise likely produces its benefits through a different mechanism. However, the small number of included articles and lack of multiple reviewers increase the risk of the result being a false negative.

Neurocognitive Functions in Patients With Remitted and Nonremitted Schizophrenia: A Cross-Sectional Study

PURPOSE

We aimed to clarify the neurocognitive features of outpatients with remitted and nonremitted schizophrenia.

DESIGN AND METHODS

The neurocognitive functions of 22 remitted and 41 nonremitted outpatients with schizophrenia and age-matched healthy controls were compared, after controlling for demographic and psychiatric variables.

FINDINGS

The spatial attention scores of both groups were lower than those of age-matched healthy controls. The processing speed and visual attention of remitted patients were better than those of nonremitted patients.

PRACTICE IMPLICATIONS

Psychiatric nurses should place patients with nonremitted schizophrenia in environments that facilitate patient vigilance and limit the need for quick responses.

Association between altered physical activity and neurocognitive function among people with schizophrenia: A minimum 6-months' follow-up study

BACKGROUND

The long-term benefits of physical activity on neurocognitive function among patients with schizophrenia, specifically among inpatients, remain unclear. This preliminary study, with a minimum of 6-months' follow-up, examined alterations in physical activity and neurocognitive function in both inpatients and outpatients with schizophrenia.

METHODS

Symptoms and neurocognitive function were assessed at 2 intervals using the Positive and Negative Symptom Scale and Cognitrax, respectively. After each testing period, participants wore an accelerometer for 1week to measure their levels and duration of physical activity. After the 6-months' follow-up (average duration, 235.9±36.2days), participants were divided into 2 groups based on either increased or decreased activity, as compared with baseline: increased-activity and decreased-activity groups.

RESULTS

Of the 29 initially enrolled participants, 25 (mean age, 56.8±11.8years) completed the follow-up. Reaction times in the increased-activity group in daily activity (n=10) improved as compared with the decreased-activity group (n=15). Moreover, cognitive flexibility and executive function improved in the increased-activity group in steps (n=7) compared with the decreased-activity group (n=18). Finally, there was no association between the duration of moderate or vigorous exercise and neurocognitive function.

CONCLUSIONS

Together, our results suggest that increased daily activity and walking, but not high intensity activity, are associated with improved neurocognitive function in patients with schizophrenia.

Correlations between physical activity and neurocognitive domain functions in patients with schizophrenia: a cross-sectional study

BACKGROUND

Neurocognitive dysfunction is a critical target symptom of schizophrenia treatment. A positive correlation between physical activity level and neurocognitive function has been reported in healthy individuals, but it is unclear whether such a correlation exists in patients with schizophrenia and whether the relationship is different according to inpatients or outpatients. This study aimed to examine the differences in the correlations between physical activity and multiple neurocognitive domains in inpatients and outpatients with schizophrenia and obtain suggestions for further study to facilitate this field.

METHODS

Twenty-nine patients with schizophrenia were examined (16 inpatients and 13 outpatients, 56.0 ± 11.4 years of age). Current symptoms were assessed using the Positive and Negative Symptom Scale and neurocognitive functions using Cognitrax, which yields a composite neurocognitive index (NCI) and 11 domain scores. After testing, participants wore an HJA-750C accelerometer for one week to measure physical activity levels and durations. Partial correlation analyses were performed between exercise and cognitive parameters.

RESULTS

In the outpatient group, higher physical activity was associated with faster Motor and Psychomotor Speeds in outpatients. However, higher physical activity was associated with lower overall NCI, Attention score, and Memory scores in inpatients.

CONCLUSION

Although higher physical activity was associated with better neurocognitive functions of outpatients, in inpatients with non-remitted schizophrenia, higher physical activity was associated with worsening of several cognitive domains. In a future study examining the relationship between physical activity and neurocognitive function for facilitating this research field, separation between inpatients and outpatients are needed because the relationship is different between inpatients and outpatients.

Polyacrylamide backbones for polyvalent bioconjugates using “post-click” chemistry

This paper reports the synthesis and application of acrylamide-type neoglycoconjugates interacting with practical targets.

A selective, high affinity 5-HT 2B receptor antagonist inhibits visceral hypersensitivity in rats

BACKGROUND

RS-127445 is a selective, high affinity 5-HT(2B)receptor antagonist. We investigated whether 5-HT(2B)receptor antagonists can reduce colonic visceral hypersensitivity caused by restraint stress or by proximal colonic inflammation.

METHODS

Visceral hypersensitivity was induced in rats by either restraint stress or injection of 2, 4, 6-trinitrobenzene sulfonic acid (TNBS) into the proximal colon. Restraint stress produced a significant increase in numbers of abdominal contractions evoked by colorectal distension (CRD), measured as a quantitative index of visceral nociception in rats. Seven days after TNBS injection, the pain threshold to CRD at the non-inflamed distal colon, that was determined as the minimum pressure required to evoke abdominal cramp, was significantly decreased. The effect of RS-127445 on visceral hypersensitivity was assessed in either naïve or TNBS-treated rats.

KEY RESULTS

Oral administration of a selective, high affinity 5-HT(2B)receptor antagonist, RS-127445, significantly inhibited visceral hypersensitivity provoked by restraint stress (35 to 74% inhibition at 1 to 10 mg kg(-1)). Oral RS-127445 produced a significant suppression of TNBS-induced visceral hypersensitivity (15 to 62% inhibition at 3 to 30 mg kg(-1)), although it was without significant effect on the visceral nociceptive threshold of naïve rats. RS-127445 (1 to 30 mg kg(-1), p.o.) also dose-dependently reduced the restraint stress-induced defecation in naïve and TNBS-treated rats.

CONCLUSIONS & INFERENCES

These results suggest that 5-HT(2B)receptors are involved in signaling from the colon in rats in which there is visceral hypersensitivity and that a selective 5-HT(2B)receptor antagonist could have therapeutic potential for the treatment of gut disorders characterized by visceral hypersensitivity.

Synthesis and pharmacological activities of novel bicyclic thiazoline derivatives as hepatoprotective agents II. (7-Alkoxycarbonyl-2,3,5,6-tetrahydropyrrolo[2,1-b]thiazol-3-ylidend) acetamid derivatives

A series of exomethylenic bicyclic thiazoline derivatives (3a--i) was synthesized and evaluated for hepatoprotective activity against galactosamine-induced and monoclonal antibody-induced acute liver injuries in rats. The structure-activity relationships were investigated. Among the compounds synthesized, N-methyl-(7-isopropoxy-carbonyl-6,6-dimethyl-2,3,5,6- tetrahydropyrrolo[2,1-b]thiazol-3-ylidene)acetamide (3i) exhibited the most potent hepatoprotective activity. This compound suppressed galactosamine-induced hepatic injury at 100 mg/kg by oral administration and further prevented monoclonal antibody-induced hepatic injury at 30 mg/kg by intraperitoneal injection, as judged from the changes in serum transaminase activities.

Synthesis and pharmacological activities of novel bicyclic thiazoline derivatives as hepatoprotective agents. I. 8-Ethoxycarbonyl-5,6-dihydrothiazolo[2,3-c][1,4]thiazine derivatives

A series of bicyclic thiazoline derivatives (4a-s) was synthesized and evaluated for hepatoprotective activity against galactosamine-induced and monoclonal antibody-induced acute liver injuries in rats. The structure-activity relationships were investigated. Among the compounds synthesized, ethyl 3-(N-methylcarbamoyl)-5,6-dihydrothiazolo[2,3-c][1,4]thiazin e-8- carboxylate (4p) exhibited remarkable hepatoprotective activity and lower toxicity. This compound suppressed galactosamine-induced hepatic injury at 100 mg/kg by gavage and further prevented monoclonal antibody-induced hepatic injury at 30 mg/kg by intraperitoneal injection, as evaluated by measuring changes in serum transaminase activities.

Species- and organ-specificity and expression of 105 kD liver cell membrane glycoprotein antigen during rat development

Species- and organ-specificity of a rat liver cell antigen recognized by a monoclonal antibody (MoAb) from a hybridoma clone RM-1 was investigated immunohistologically and immunoelectronmicroscopically. In rats, the MoAb reacted specifically with liver cell membrane, but not with other organs tested, including the brain, thymus, heart, lung, stomach, spleen, kidney, small and large intestines, testis and muscle. Furthermore, it was found that liver from the human, monkey, mouse, rabbit, guinea pig, dog, cat, cattle and chicken showed no specific reaction with this MoAb. The results indicated that the antigen was organ- and species-specific and designated as rat liver cell-specific membranous antigen (RLSA). RLSA was expressed scarcely along cell junctions of immature hepatocytes at the 19th day of pregnancy. This increased gradually, and was expressed along all surface membranes after birth.

Antisecretory and antiulcer effects of ebselen, a seleno-organic compound, in rats

The effects of ebselen (2-phenyl-1,2-benzisoselenazol-3(2H)-on), a metal-containing organic compound, on gastric secretion and gastric ulceration were examined in rats. Intraduodenal ebselen (30 to 300 mg/kg) significantly and dose-dependently inhibited gastric secretion in pylorus-ligated rats. Both aspirin- and water-immersion restraint stress-induced ulcers were significantly prevented by oral administration of ebselen at doses equivalent to the antisecretory doses. These results indicate that the antisecretory effect of ebselen underlies its antiulcer effect in these models.

Effect of DS-4574, a novel peptidoleukotriene antagonist with mast cell stabilizing action, on acute gastric lesions and gastric secretion in rats

DS-4574 is a peptidoleukotriene antagonist with mast cell stabilizing activity. In the present study, we studied the effects of this compound on gastric secretion and various acute gastric lesions in rats. Intraduodenal administration of DS-4574 at doses of 5 to 10 mg/kg significantly and dose-dependently inhibited gastric acid secretion in pylorus-ligated rats, but a further increase in the dose up to 50 mg/kg did not cause any further inhibition. Shay ulceration in response to pylorus ligation was dose-dependently prevented by DS-4574 (10-25 mg/kg, i.d.). Water-immersion restraint stress- and aspirin-induced gastric ulcers were also significantly prevented in a dose-related manner by oral pretreatment with DS-4574 (10-50 mg/kg). The lower doses of DS-4574 (1-10 mg/kg, p.o.) significantly and dose-dependently protected the gastric mucosa against the necrotizing action of either absolute ethanol or concentrated hydrochloric acid, indicating that this compound possesses a potent gastroprotective activity. These antiulcer and gastric protective effects of DS-4574 were more potent than those of cimetidine used as a reference drug. These findings suggest that DS-4574 is useful for peptic ulcer therapy, as well as for the therapy of various allergic diseases, including asthma.

Protective effect of 16,16-dimethyl prostaglandin E2 on isolated rat hepatocytes against complement-mediated immune attack

16,16-Dimethyl prostaglandin E2 was examined for its ability to inhibit complement-mediated in vitro hepatocytolysis by an antigen-antibody reaction. In the presence of fresh rat serum as a source of complement, 5-min culture of isolated rat hepatocytes with a monoclonal antibody against a rat liver-specific membranous antigen resulted in a marked, significant elevation in lactate dehydrogenase leakage into the culture medium. However, with heat-inactivated rat serum, such a reaction did not occur, indicating that the hepatocytolysis induced by the antibody was attributable to the membrane damaging action of complement activated by an antigen-antibody reaction. Pretreatment of the hepatocyte with 16,16-dimethyl prostaglandin E2 significantly suppressed the cytolytic reaction induced by the antibody in a concentration-dependent manner. These results show that 16,16-dimethyl prostaglandin E2 is capable of protecting isolated rat hepatocytes against the membrane-damaging insult of activated complement.

Protection by 16,16-dimethyl prostaglandin E2 and dibutyryl cyclic AMP against complement-mediated hepatic necrosis in rats

16,16-Dimethyl prostaglandin E2, a known cytoprotective agent, was examined for its ability to protect the liver against complement-mediated necrosis induced by an intravenous injection of a monoclonal antibody against a rat liver-specific antigen in rats. The hepatic injury induced by the antibody was characterized by (a) rapid development of numerous massive hemorrhagic foci of necrotic liver cells, (b) marked increases in serum liver enzyme activities and (c) pronounced reduction in the CH50 level, presumably as a result of complement consumption in the liver. Pretreatment with 16,16-dimethyl prostaglandin E2 at intraperitoneal doses of 20 and 100 micrograms/kg suppressed the hepatic injury, as evidenced by markedly mitigated liver-cell necrosis and much smaller increases in the serum-enzyme activities compared with the values in diseased control animals. The prostaglandin analogue failed to prevent serum complement consumption in response to the antibody injection or affect the CH50 level at the preinjury stage, indicating that neither complement inactivation nor interference with the antigen-antibody reaction was involved in the hepatic protection. The hepatoprotective doses of 16,16-dimethyl prostaglandin E2 produced a significant increase in liver cyclic AMP content in a dose-related manner. In addition, intravenous dibutyryl cyclic AMP at 3 and 10 mg/kg dose-dependently prevented histological and biochemical changes in the hepatic damage without altering the rate of reduction in serum complement activity. Like 16,16-dimethyl prostaglandin E2, dibutyryl cyclic AMP did not affect the preinjury CH50 level.(ABSTRACT TRUNCATED AT 250 WORDS)

Colonization of Helicobacter pylori in the gastric mucosa of Mongolian gerbils

Helicobacter pylori was orally inoculated into Mongolian gerbils. The organisms were able to colonize in the gastro-mucosal layer of the gerbils, especially in those gerbils which had mucosal lesions caused by indomethacin treatment. The pathological changes developed by H. pylori infection were restricted to the stomachs, and only slightly inflammatory cells were observed.

A rat model of acute liver necrosis induced by a monoclonal antibody to liver-specific antigen and complement

Acute massive hepatic injury was induced in rats by a monoclonal antibody against a rat liver-specific membrane antigen, and its histological characteristics were investigated. A single intravenous injection of murine ascites containing a monoclonal antibody produced numerous hemorrhagic foci of degenerated and necrotic liver cells predominantly in zones 1 (the periportal area) and 2 (the area of transition between the periportal zone and the perivenular zone) of the liver lobule within 10 min. Massive hepatocellular necroses were observed 1 hr later, but no inflammatory cell infiltration occurred in and around the necrotic foci. Immunohistological study demonstrated marked deposition of the third component of the complement system in the necrotic area. Serum complement activity was sharply decreased immediately after the injection of the antibody, suggesting that the hepatic necrosis is ascribable to a complement-mediated immune attack on the liver cell membrane induced by the antigen-antibody reaction. The hepatic necrosis in response to monoclonal-antibody injection did not progress to a chronic disease and healed almost completely, changing to scar tissues within 2 wk. Although it is not clear whether this hepatic injury has any clinical relevance, this antibody/complement model may be useful for investigating the cause and therapy of hepatic diseases such as fulminant hepatitis.

[Comparison of three methods for detecting Campylobacter pylori and measurement of human antibody titers against the whole organisms]

In order to detect Campylobacter pylori in the gastric mucosa, three different methods as 1) culture of the organisms, 2) immunostaining by monoclonal antibody against the cells, and 3) urease test were compared. In the disease group, positive % of each methods was 64, 75 and 74. However, positive % common to the three methods was only 48. The corresponding rate of culture and urease tests, and that of culture and staining methods was 81% and 60%, respectively. Therefore, it was concluded that urease test was a useful method, and that the three methods were necessary to confirm the existence of the organisms in the gastric mucosa. Total positive % of culture and staining methods in disease and control groups was 77 and 31, respectively, indicating that positive % of the disease group was much higher than that of the control group. Anti C. pylori titer was compared between culture-positive and culture-negative patients by ELISA. The titer of the former was significantly higher than that of the latter.

Antiulcer effects of 3-[[[2-(3,4-dimethoxyphenyl)ethyl] carbamoyl]methyl]-amino-N-methylbenzamide in experimental gastric and duodenal ulcers

Effects of 3-[[[2-(3,4-dimethoxyphenyl)ethyl]carbamoyl] methyl]-amino-N-methylbenzamide (DQ-2511), a newly synthesized compound, were evaluated using various types of experimental gastric and duodenal ulcers in rats. Pretreatment with DQ-2511, over the dose range 30-300 mg/kg p.o., resulted in a dose-related inhibition of water-immersion stress-, serotonin-, acetylsalicylic acid (ASA)-, indometacin-, ethanol-, and 2-deoxy-D-glucose(2DG) plus indometacin-induced gastric ulcers as well as cysteamine-induced duodenal ulcers. The antiulcer potencies of DQ-2511 were equal to or greater than those of H2-receptor antagonist cimetidine in these ulcer models except for ASA- and 2DG plus indometacin-induced ulcers. The rate of healing of chronic gastric ulcers induced by acetic acid was significantly accelerated by DQ-2511 (100 and 300 mg/kg p.o.) but not by the same doses of cimetidine. DQ-2511, at doses of 30 mg/kg p.o. and above, produced a significant decrease in gastric acid and pepsin output in pylorus-ligated rats. In anesthetized rats with acute gastric fistulae, 30 mg/kg i.v. of DQ-2511 significantly inhibited gastric acid secretion stimulated by 2DG, whereas it did not affect gastric hyperacidity evoked by either carbachol, histamine or pentagastrin. At effective antiulcer doses, this compound produced a sustained increase in gastric mucosal blood flow in conscious, restrained rats. Based on these observations, DQ-2511 is characterized as a new antiulcer compound with beneficial effects on both gastric aggressive and defensive factors. Furthermore, these results indicate a possible superiority of DQ2511 over cimetidine in regard to its antiulcer potency and spectrum.

Chemiluminescence and phagocytic responses of rat polymorphonuclear neutrophils to leptospires

The interaction of leptospires with polymorphonuclear neutrophils (PMN) was examined by the luminol-dependent chemiluminescence (CL) test. Whole blood CL changed in relation to the stage of leptospiral infection both in susceptible (SUS) and resistant (RES) rats. The intensity of CL grew with an increasing number of leptospires in the blood. CL responses were observed in isolated PMN upon exposure to living leptospires. In contrast, the same bacteria, having been inactivated by formalin, did not stimulate PMN. A variation was found in the CL response by different living strains of Leptospira. The CL intensity was arranged as follows: L. illini greater than L. biflexa greater than L. interrogans avirulent strains greater than L. interrogans virulent strains. The CL response was markedly enhanced by an opsonization of leptospires. Specific opsonization was shown to increase the rate of phagocytosis of leptospires with relation to the CL response.

Gastric cytoprotection by ebselen against the injury induced by necrotizing agents in rats

The gastric cytoprotective effect of ebselen (2-phenyl-1,2-benzisoselenazol-3(2H)-one), a novel seleno-organic antioxidative agent, against the insults of necrotizing agents was investigated in rats. Either 0.6 N HCl or acidified ethanol (60% ethanol in 150 mmol/l HCl), given orally in a volume of 1 ml, produced linear hemorrhagic necroses in the gastric mucosa within 1 h. Pretreatment with ebselen at oral doses from 10 to 100 mg/kg significantly inhibited such lesion formation induced by either necrotizing agent in a dose-related manner, and the inhibition at the highest dose (100 mg/kg p.o.) was practically complete. Light microscopic analysis also confirmed that ebselen effectively prevented the formation of deep mucosal necrosis in response to the necrotizing agents. In addition, the protection by ebselen of gastric necrosis induced by either damaging agent was not affected by pretreatment of animals with indomethacin (5 mg/kg s.c.), indicating that the protective effect of this agent was not mediated by the mild irritation on the gastric mucosa. These results demonstrate that ebselen is a potent cytoprotective agent effectively preventing the gastric mucosal injury induced by necrotizing agents.

Cytoprotective action of cetraxate against HCl.ethanol-induced gastric lesion in rats

The protective effect of cetraxate, an antiulcer and antigastritis agent, on HCl.ethanol-induced gastric lesions was investigated in rats. Oral administration of 1 ml of HCl.ethanol (60% ethanol in 150 mM HCl) induced within 1 hr linear hemorrhagic necrosis in the gastric mucosa. Either oral or intraperitoneal treatment with cetraxate (30-300 mg/kg) significantly inhibited such macroscopic gastric lesions in a dose-related manner, and the inhibition at the oral highest dose (300 mg/kg) was practically complete. Histological analysis also confirmed that cetraxate effectively prevented deep mucosal necrosis, but showed that it was without protective effect on the surface epithelial disruption and submucosal edema in response to HCl.ethanol. The antilesion activity of cetraxate was of statistically significance for at least 3 hr after a single injection, and it was hardly affected by the removal of the gastric contents just prior to application of the necrotizing agent. However, subcutaneous treatment of rats with indomethacin (5 mg/kg) resulted in a partial but significant attenuation in the protection afforded by cetraxate, suggesting that dual mechanisms related and unrelated to endogenous prostaglandins may be involved in its protective activity. The results demonstrate that cetraxate is a potent cytoprotective agent effectively preventing the formation of gastric mucosal necrosis induced by HCl.ethanol.

Biological activities of leptospiral lipopolysaccharide

Lipopolysaccharide extracted with phenol-water from Leptospira interrogans serovar copenhageni strain Shibaura (L-LPS) showed various biological activities. In lethality for mice, L-LPS was active (LD 50, 3.4 mg/mouse) but about 12 times less potent than Escherichia coli LPS (E-LPS) per weight basis. L-LPS had pyrogenicity for rabbits, and the fever curves showed no evidence of the classical biphasic fever produced by E-LPS. In the bone marrow of mice, L-LPS caused hemorrhages and necrosis but less severe than those caused by E-LPS. Histopathologically, fresh hemorrhages were found in the intestine, spleen, lung and the other organs at 24 h after inoculation of L-LPS. Necrosis was also found in these organs and was particularly severe in mice inoculated with more than 2 mgL-LPS. Liver necrosis was found at 7th day after inoculation of L-LPS but not after inoculation of E-LPS. L-LPS had adjuvant activity just like E-LPS. L-LPS enhanced non-specific resistance to Salmonella infection and activated mouse peritoneal macrophages to kill these organisms. L-LPS was positive in limulus test just like E-LPS. These results demonstrated similarities of L-LPS and E-LPS. Some toxic effects of L-LPS were less than those of E-LPS, but some effects of L-LPS were more than those of E-LPS. L-LPS was antigenically active and the specificity was serogroup-associated. L-LPS was composed of carbohydrate (54%), lipid (12%), protein (5%). Arabinose, xylose and rhamnose were major sugars as detected by gas chromatography. 2-keto-deoxyoctanate (KDO) was not detectable.

Phagocytosis as a defense mechanism against infection with leptospiras

The role of macrophages in host defense was studied in vivo and in vitro. The intravenous administration of silica, an agent reported to selectively inactivate macrophages, increased the sensitivity to leptospiral infection and inhibited bacterial clearance. Active immunization with killed organisms or with leptospiral lipopolysaccharide (L-LPS), and passive immunization with a monoclonal antibody showed powerful protective effects against infection in mice. The effect of immunization decreased in silica-treated mice. These findings were supported by electron microscopic examination and observation of killing by macrophages in vitro.

Changes in duodenal mucosal blood flow and mucus glycoprotein content during cysteamine-induced duodenal ulceration in rats

The effects of cysteamine on duodenal mucosal blood flow and duodenal glycoprotein were studied during the development of duodenal ulceration in conscious rats. Cysteamine at an ulcerogenic dose (300 mg/kg s.c.) produced a remarkable decrease of duodenal mucosal blood flow which preceded the appearance of duodenal ulcers. The reduced blood flow was followed by a significant decrease of tissue levels of glycoprotein which also occurred prior to the time when duodenal injury had reached a maximum. Cysteamine was without significant effect on the rate of incorporation of 3H-glucosamine into duodenal glycoprotein at concentrations up to 10(-3) M. These results suggest that the reduction in duodenal mucosal blood flow in response to cysteamine could possibly contribute to a decrease of duodenal glycoprotein and that both may be at least in part responsible for the incidence of duodeno-ulcerogenecity.

Dulcerozine-induced duodenal ulcers in rats: a simple, highly-reliable model for evaluating anti-ulcer agents

Dulcerozine-induced duodenal ulcers in rats were studied in order to establish the optimum conditions for a routine production of ulcers and to elucidate their possible pathogenesis. Single doses of dulcerozine administered either subcutaneously or orally produced a dose-related duodenal ulceration in rats. The ulcerogenic effect of dulcerozine was most potent when given subcutaneously to 24-hr fasted animals at 300 mg/kg. At this dose, deep or perforating ulcers were consistently produced within 18 hr, but mortality due to general toxicity of the agent was excluded at least up to 48 hr. Feeding of animals resulted in a significant reduction in susceptibility to dulcerozine. An antacid and antisecretory agents prevented dulcerozine-induced duodenal ulceration in a dose-dependent manner. Either pylorus ligation or vagotomy completely inhibited duodenal ulceration in response to dulcerozine. In addition, an ulcerogenic dose (300 mg/kg s.c.) of dulcerozine evoked a sustained gastric hypersecretion in pylorus ligated rats. These results suggest that a stimulating action on gastric secretion may be, at least in part, responsible for the ulcerogenic property of dulcerozine. The present study provides a new reliable model for investigations of the pathogenesis and therapy of duodenal ulcer disease.

Serial endoscopic observation of swine gastroesophageal ulceration induced by injection of a histamine-oil-beeswax mixture

The gastroesophageal (GE) area of swine was endoscopically observed before and after injection of a histamine-oil-beeswax mixture (5 mg of histamine/kg of body weight). The swine were anesthetized with halothane, and a rigid endoscope was inserted through a gastric cannula placed in the proximal greater curvature of the stomach. Observation was simple and the procedure lasted less than 10 minutes, without adverse reactions. In 4 swine with normal GE areas, hemorrhage was found at postmedication hour (PMH) 3 and ulcerative changes were seen at PMH 9 to 12. A more rapid pathologic change of the GE area was found in 2 animals with hyper- or parakeratotic changes before medication. Abnormalities were found up to PMH 9 in the GE area of 2 animals in which the stomach cannula was opened to allow the escape of gastric juice.

Three compartment model for pyrimethamine disposition in the pig

Plasma concentration and urine excretion of pyrimethamine (Py) after intravenous (i.v.) administration (10 mg/kg) were determined in four pigs, using NP-FID gas chromatography. A three-compartment model system adequately fitted the observed plasma data. Py may undergo an extensive extravascular distribution, because of the ratio of total volume of distribution to volume of the central compartment was extremely large (about 10). From the calculation of theoretical distribution, only 30% of the dose appears to remain in the central compartment 15 min after administration. Within 2 h of administration the proportion of drug within the two identified peripheral compartments exceeded the proportion remaining in the central compartment. Calculation of cumulative drug excretion showed that up to 90% of an administered dose is excreted within 24 h of administration, although only about 3% of the dose could be detected in urine in an unchanged form during the 24 h period.