Clinical trial: Clinical and endoscopic outcomes with ustekinumab in patients with Crohn's disease: Results from the long-term extension period of STARDUST

BACKGROUND

STARDUST, a phase 3b randomised trial, compared ustekinumab therapeutic strategies in patients with Crohn's disease (CD) using early endoscopic assessment and treat-to-target (T2T) versus standard of care (SoC).

AIM

To assess the efficacy of ustekinumab extended treatment in a long-term extension (LTE) of up to 104 weeks with dosing adapted according to clinical, biomarker and endoscopy outcomes.

METHODS

Adults with moderately-to-severely active CD received intravenous ustekinumab approximating 6 mg/kg at Week 0 and subcutaneous ustekinumab 90 mg at Week 8. At Week 16, 440 ≥70-point responders were randomised to T2T or SoC and 323 entered the LTE. At Week 48, a unified, protocol-defined ustekinumab dose frequency escalation/de-escalation was applied based on achieving endoscopic remission and corticosteroid-free clinical remission. Achieving corticosteroid-free clinical remission and biomarker remission at consecutive visits determined ustekinumab dosing frequency. Dichotomous variables were analysed using non-responder imputation.

RESULTS

Among patients who entered the LTE, 7.7%, 48.6% and 43.7% received doses every 4, 8 and 12 weeks, respectively. Ustekinumab dose frequency was escalated in 23.5% and de-escalated in 19.7%. Endoscopic response and remission rates were 28.9% and 10.73% (all randomised) and 39.3% and 14.6% (patients entering the LTE), respectively, at Week 104. Clinical remissiona rates at week 104 were 50.2% (all randomised) and 68.4% (patients entering the LTE). There were no new safety signals.

CONCLUSION

STARDUST LTE is the first interventional ustekinumab efficacy study to show a favourable benefit-risk profile with preservation of clinical and endoscopic outcomes through Week 104 using flexible, algorithm-driven dose adjustment including de-escalation.

Ustekinumab improves health-related quality of life in patients with moderate-to-severe Crohn's disease: Results up to Week 104 of the STARDUST trial

BACKGROUND

STARDUST is a phase 3b randomized controlled trial comparing two ustekinumab treatment strategies in patients with Crohn's disease (CD): treat-to-target (T2T) versus standard of care (SoC).

OBJECTIVE

We investigated the effect of a T2T or SoC ustekinumab treatment strategy on health-related quality of life (HRQoL) and work productivity and activity impairment (WPAI) over a 2-year follow-up period.

METHODS

At Week 16, adult patients with moderate-to-severe active CD were randomized 1:1 to either T2T or SoC treatment groups. We assessed changes from baseline in HRQoL measures (Inflammatory Bowel Disease Questionnaire [IBDQ], EuroQoL 5-dimension 5-level [visual analogue scale and index], Functional Assessment of Chronic Illness Therapy-Fatigue, Hospital Anxiety and Depression Scale-Anxiety and -Depression) and the WPAI questionnaire in two patient populations: randomized analysis set (RAS, patients randomized to either T2T or SoC at Week 16 and completed Week 48) and modified RAS (mRAS, patients who entered the long-term extension [LTE] period at Week 48).

RESULTS

At Week 16, 440 patients were randomized to T2T (n = 219) or SoC (n = 221) arms; 366 patients completed Week 48. Of these, 323 patients entered the LTE and 258 patients completed 104 weeks of treatment. In the RAS population, percentages of patients achieving IBDQ response and remission were not significantly different between treatment arms at Weeks 16 and 48. In the overall mRAS population, IBDQ response and remission increased over time from Weeks 16-104. In both populations, improvements from baseline in all HRQoL measurements were observed at Week 16 and maintained until either Week 48 or Week 104, respectively. In both populations, improvements from baseline in T2T and SoC arms at Weeks 16, 48 or 104 in WPAI domains were observed.

CONCLUSION

Independent of treatment strategy (T2T or SoC), ustekinumab was effective in improving HRQoL measurements and WPAI over a period of 2 years.

Early Ultrasound Response and Progressive Transmural Remission After Treatment With Ustekinumab in Crohn's Disease

BACKGROUND & AIMS

In this STARDUST substudy, the effect of ustekinumab on transmural bowel inflammation was assessed in adults with moderate-to-severe Crohn's disease (CD) by using intestinal ultrasound (IUS), a noninvasive imaging procedure.

METHODS

STARDUST was an international, multicenter, phase 3b, interventional, randomized controlled trial specifically designed to compare treat-to-target and standard-of-care treatment strategies in ustekinumab-treated CD patients. In this substudy, the most affected bowel segment at baseline by IUS was used for all analyses. Key IUS endpoints (centrally read, parameter-blinded) were IUS response, transmural remission, bowel wall thickness (BWT), blood flow, bowel wall stratification, and inflammatory fat.

RESULTS

Seventy-seven patients were evaluated. IUS response could be determined 4 weeks after treatment initiation, with progressive improvement through week 48. IUS response and transmural remission rates at week 48 were 46.3% and 24.1%, respectively. IUS response, transmural remission, BWT, and blood flow normalization rates were more pronounced in the colon and biologic-naive patients. Fair/moderate reliability (κ = 0.21-0.51) was observed between week 4 IUS response and week 48 overall endoscopic response and fecal calprotectin/complete biomarker outcomes. Endoscopy and IUS baseline agreement was >90% in determining the terminal ileum as the most affected bowel segment. IUS response absence at week 4 was associated with no endoscopic response (based on the simplified endoscopic score for Crohn's disease terminal ileum subscore) at week 48 (negative predictive value = 73%).

CONCLUSIONS

In this first international, multicenter, interventional study, IUS showed that ustekinumab-treated CD patients achieved progressive IUS response (46.3%) and transmural remission (24.1%) through week 48, with a more robust response in the colon and biologic-naive patients.

CLINICALTRIALS

gov number: NCT03107793.

Early Symptomatic Improvement After Ustekinumab Therapy in Patients With Ulcerative Colitis: 16-Week Data From the UNIFI Trial

BACKGROUND & AIMS

Rapid symptomatic relief is an important treatment goal for patients with ulcerative colitis (UC). We aimed to characterize early response with ustekinumab in patients with moderate-to-severe UC during the initial 16 weeks of treatment.

METHODS

We performed a post hoc analysis of data from A Study to Evaluate the Safety and Efficacy of Ustekinumab Induction and Maintenance Therapy in Participants With Moderately to Severely Active Ulcerative Colitis trial. Patients (N = 961) were randomized (1:1:1) to receive intravenous 130 mg ustekinumab, approximately 6 mg/kg ustekinumab, or placebo at week 0. Symptomatic remission, absolute stool number, Mayo stool frequency and rectal bleeding subscores, partial Mayo score, C-reactive protein, and fecal calprotectin were assessed in the overall population and for patients in the biologic-naïve or prior biologic failure subgroups.

RESULTS

A significantly greater percentage of patients in the 130-mg ustekinumab (20.0%; P = .015) or approximately 6-mg/kg ustekinumab (20.2%; P = .012) groups achieved symptomatic remission at week 2 vs placebo (12.9%). Mean [SD] changes from baseline in daily stool number on day 7 were greater in the ustekinumab groups (-1.1 [2.6] in 130 mg [P = .065] and -1.2 [2.5] in ∼6 mg/kg [P = .017]) vs placebo (-0.7 [2.7]). The percentage of patients with Mayo stool frequency subscore of 1 or less and rectal bleeding subscore of 0 increased from baseline through week 16 for both ustekinumab groups. Significant improvements in partial Mayo scores were observed by week 2 in both ustekinumab groups vs placebo (P ≤ .001). Significantly more patients in the ustekinumab groups had normalized C-reactive protein levels from week 2 to week 8 vs placebo (P ≤ .05). Similar results were observed with normalized fecal calprotectin levels between week 2 and week 4 (P ≤ .05).

CONCLUSIONS

Ustekinumab improved symptoms in patients with UC compared with placebo in as early as 7 days, indicating rapid onset of effect after induction.

CLINICAL TRIAL REGISTRY NUMBER

ClinicalTrials.gov: NCT02407236.

Effects of various epiphytic microbiota inoculation on the fermentation quality and microbial community dynamics during the ensiling of sterile Napier grass

AIM

To investigate epiphytic microbiota transformation of forages, their adaptation and contributions to fermentation quality of silage.

METHODS AND RESULTS

Gamma-irradiated chopped Napier grass were ensiled with distilled water (STR), extracted epiphytic microbiota of Napier grass (NAP), sudan grass (SUD), whole crop corn (WCC) and forage sorghum (FS). Inoculating Napier grass with WCC significantly increased lactic acid (LA) concentrations during the initial ensiling period followed by a decline after 30 days. Relative to other silages (except STR) inoculation with NAP resulted in lower LA and greater pH, ammonia-N and dry matter (DM) losses. Silage inoculated with FS and SUD maintained lower pH as well as higher (P < 0·05) LA concentrations after 60 days of storage. During day 3 of ensilage, WCC, NAP and SUD inoculated silage were dominated by bacterial genera of Lactobacillus, while Lactococcus dominated the FS silage. Final silages were dominated by Lactobacillus in all treatment silages, however Enterobacter (16·3%) in NAP and Acetobacter (25·7%) in WCC silage were also prominent during the final ensiling.

CONCLUSION

The inoculation of epiphytic microbiota of forage sorghum and sudan grass positively influenced the microbial community and fermentability of sterile Napier grass silage.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first time to investigate the effects of various epiphytic microbiota as silage inoculants which can be used as alternative source of environmental friendly and economically feasible silage additives.

Thoracoscopic cryoanalgesia: A new strategy for postoperative pain control in minimally invasive pectus excavatum repair

OBJECTIVE

Recent publications report early discharge and low opioid requirements after minimally invasive pectus excavatum repair treated with bilateral intercostal nerve cryoablation. Our aim is to report our initial experience with this technique.

MATERIAL AND METHODS

Retrospective analysis of medical records of patients undergoing bilateral thoracoscopic cryoanalgesia during minimally invasive pectus excavatum repair within our institution from September 2018 to March 2019.

TECHNIQUE

A cryoprobe was applied at -70 ºC for 2 minutes each from the 3rd to the 7th intercostal nerves bilaterally under thoracoscopic control. Postoperative pain was assessed using a visual analogue scale (VAS).

RESULTS

Twenty-one patients were included. Ninety percent were male, the mean age being 15.2 ± 4.29 years, and the mean weight being 53.6 ± 15.33 kg. The average Haller index was 5.1 ± 2.97, and the mean repair index was 37.6 ± 13.77%. The mean number of implants introduced was 2.55 ± 0.74. The mean duration of cryoanalgesia was 39.9 ± 21.1. No patients received epidural anesthesia. Mean postoperative stay was 1.64 ± 0.73 days. Seventy-one percent of the patients required 1 dose of opioids at the most for postoperative pain control. According to the VAS, the average pain score on postoperative days 1, 3, 7, and 21 was 2.55, 2.01, 0.5, and 0.06, respectively.

CONCLUSIONS

Bilateral thoracoscopic cryoanalgesia during minimally invasive pectus excavatum repair leads to early discharge and good postoperative pain control in all cases. Cryoanalgesia has become our treatment of choice for pain control in the thoracoscopic repair of pectus excavatum.

Prevalence of Degnala disease in bovine along with screening of toxigenic fungi isolated from contaminated rice straw

Toxigenic potential of different candidate fungi, isolated from rice straw feed of Degnala disease affected bovines was analyzed along with species, age, gender and seasonal prevalence. Of 1,536 cases, 104 (6.77%) showed positive signs with a significant association (p less than 0.05) between this disease and rice straw feeding, in buffaloes, and bovine aged over 1 year in the winter season. Complete blood count showed a marked increase in erythrocyte sedimentation rate and all white blood cells numbers, except lymphocytes in positive cases. There was a significant increase (p less than 0.05) in alanine amino transferase, aspirate amino transferase and alkaline phosphatase in the liver function test. At the same time, an increased value of creatinine was noted in the renal function test. For isolation and screening of toxigenic fungi, rice straw samples (n=40) being fed to the positive cases were processed further, and 85 fungal isolates were found, mainly of Aspergillus (57), Penicillium (10), Fusarium (04), Zygomycetes (03), Curvularia (01) and unidentified (10). All isolated fungi were subjected for mycotoxin production and only 11 showed mycotoxin-producing capability (including Aspergillus, Penicillium and Fusarium isolates) analyzed by thin layer chromatography and quantified through high performance liquid chromatography. It is concluded that all the fungi contaminating rice straw feed of Degnala affected animals were not toxigenic. This work will help in establishing major mycotoxin-producing fungi leading to the probable cause of Degnala disease in bovine.

Tolerability of canagliflozin in patients with type 2 diabetes mellitus fasting during Ramadan: Results of the Canagliflozin in Ramadan Tolerance Observational Study (CRATOS)

AIMS

There is a large population of people with type 2 diabetes mellitus (T2DM) who are Muslim and fast during Ramadan. Changes in the pattern and amount of meal and fluid intake during Ramadan, in addition to the long fasting hours, may increase the risk of hypoglycaemia, hyperglycaemia, and dehydration. The Canagliflozin in Ramadan Tolerance Observational Study (CRATOS) evaluated the tolerability of canagliflozin, a sodium glucose co-transporter 2 inhibitor, compared with sulphonylureas among patients with T2DM who fast during Ramadan.

METHODS

This non-randomised, parallel-cohort, prospective, comparative, observational study was conducted in the Middle East during Ramadan and enrolled patients who were taking canagliflozin (n=162) or any sulphonylurea (n=159) added to metformin±dipeptidyl peptidase-4 inhibitor. The proportion of patients who experienced hypoglycaemia events was assessed as the primary end-point. Between-cohort comparisons were adjusted using propensity score analysis.

RESULTS

During Ramadan, fewer patients experienced symptomatic hypoglycaemia with canagliflozin vs sulphonylurea (adjusted odds ratio: 0.273 [95% CI: 0.104, 0.719]). Of hypoglycaemia events for which blood glucose was measured, two of six with canagliflozin and 27 of 37 with sulphonylurea were confirmed by blood glucose <3.9 mmol/L. More patients treated with canagliflozin experienced volume depletion events compared with sulphonylurea (adjusted odds ratio: 3.5 [95% CI: 1.3, 9.2]). Missed fasting days were few and medication adherence was high in both groups. No patients treated with canagliflozin and 9.4% treated with sulphonylurea adjusted their medication dose near the beginning of Ramadan. Both treatments were generally well tolerated, with low rates of adverse events and no serious adverse events in either group.

CONCLUSIONS

Overall, these findings support the use of canagliflozin for the treatment of adults with T2DM who fast during Ramadan. CLINICALTRIALS.

GOV IDENTIFIER

NCT02737657.

Genotyping of Acanthamoeba isolated from water in recreational areas of Tehran, Iran

A comprehensive survey assessing the presence of Acanthamoeba was conducted on 50 samples from water sources in parks and public squares from 22 municipal districts of Tehran, Iran. The prevalence and genotypes of Acanthamoeba were determined by PCR and the PCR fragments of ribosomal RNA genes sequenced. Sixteen (32%) samples were positive for Acanthamoeba spp. Sequence analysis revealed that the positive isolates belonged to the T4 and T5 genotypes. Fourteen isolates (87.5%) were T4, and two (12.5%) were T5. Acanthamoeba may be a problematic organism for contact lens wearers and for immunocompromised individuals. In Iran, Acanthamoeba keratitis has increased in recent years, mainly due to poor hygiene in contact lens wearers. A thorough survey for the prevalence of this amoeba could have a significant role in prevention of disease. This is the first report of the T5 genotype from water in recreational areas of Tehran.

Multicenter, open-label, nonrandomized, observational safety study in subjects using insulin aspart in basal-bolus regimen for the treatment of diabetes

INTRODUCTION

Basal-bolus insulin therapy is a standard method of intensifying diabetes treatment. A common adverse effect of such treatment is hypoglycemia. Data on frequency of hypoglycemia when fast-acting insulin analogue is used in everyday clinical practice is scarce.

OBJECTIVES

The aim of the study was to investigate the risk of hypoglycemia after the use of insulin aspart in basal-bolus therapy in patients with type 1 and 2 diabetes.

PATIENTS AND METHODS

It was a multicenter, open-label, noninterventional study. It involved 950 patients with type 1 and 1332 patients with type 2 diabetes who started preprandial insulin aspart in basal-bolus regimen. Patients were followed for 13 weeks. The primary endpoint was the incidence of major daytime and nocturnal hypoglycemic events assessed on the basis of patients' self-reports during follow-up compared with a 4-week period before the baseline visit. Secondary endpoints were: incidence of minor daytime and nocturnal hypoglycemia, hemoglobin A1c (HbA1c), fasting and postprandial glycemia.

RESULTS

The rate of major hypoglycemia decreased in patients with type 1 diabetes--the incidence rate ratio (IRR) was 0.14 for daytime and 0.03 for nocturnal episodes (P <0.0001) and did not change in patients with type 2 diabetes. The rate of minor episodes decreased in patients with type 1 diabetes (IRR = 0.44 for daytime and IRR = 0.24 for nocturnal episodes, P <0.0001) and in patients with type 2 diabetes (IRR= 0.57, P <0.0001 for daytime and IRR = 0.89, P <0.05 for nocturnal episodes). HbA1c decreased by 1.28 ± 1.64% in type 1 and 1.25 ± 1.10% in type 2 diabetes (both P <0.0001). Self-measured fasting and postprandial blood glucose levels were significantly lower at the final visit compared with baseline, irrespective of diabetes type.

CONCLUSIONS

In clinical practice, treatment with insulin aspart in basal-bolus regimen is associated with low risk of hypoglycemia and leads to a significant improvement in glucose control, irrespective of diabetes type.

The influence of serotonin depletion on rat behavior in the Vogel test and brain 3H-zolpidem binding

The influence of p-chlorophenylalanine (p-CPA) and 5,7-dihydroxytryptamine (5,7-DHT)-induced serotonin depletion on rat behavior as well as on zolpidem's the behavioral effects and binding to some brain areas of zolpidem, was examined with the help of Vogel's punished drinking test and autoradiography, respectively. Moreover, changes in the serotonin levels and turnover rate were studied in the forebrain and brainstem of rats pretreated with various ligands at the benzodiazepine (BDZ) receptors (midazolam, bretazenil, abecarnil, zolpidem). These drugs were given at doses shown previously to significantly disinhibit animal behavior suppressed by punishment in the Vogel test (Nazar et al., 1997). It was found that serotonin decrease in the frontal cortex and hippocampus after p-CPA significantly and inversely correlated with rat behavior controlled by fear in the VT. p-CPA produced an anticonflict activity in the absence of effect on spontaneous drinking, pain threshold and motility of animals. All applied benzodiazepine receptor ligands decreased the 5-HT turnover rate in the frontal cortex and hippocampus, whereas in the brainstem only abecarnil and zolpidem diminished 5-hydroxyindoleacetic acid levels. This part of the study replicated earlier data with neurotoxins and indicated that the anxiolytic-like effect of 5-HT depletion in some models of anxiety did not depend on changes in animal appetitive behavior or stimulus control. Moreover, the fact that all nonselective and selective (zolpidem) agonists of the type 1 benzodiazepine receptors seemed to produce the same anticonflict effect and decreasing 5-HT turnover indicates that this subtype of benzodiazepine receptor may be important for the interaction between brain 5-HT and GABA/BDZ systems. Accordingly, it was found that serotonin decrease enhanced the anticonflict effect of zolpidem in the Vogel test and increased 3H-zolpidem binding to the occipital cortex and substantia nigra. Altogether, the present study provides more arguments for the role of changes in the activity of brain 5-HT innervation in the control of emotional processes. Moreover, it points to the BDZ1 receptor subtype as a possible target of interaction between brain 5-HT and GABA(A)/BDZ systems.

The role of the hippocampus and 5-HT/GABA interaction in the central effects of benzodiazepine receptor ligands

The effects of an intrahippocampal administering of a nonselective full (midazolam), a partial benzodiazepine (BDZ) receptor agonist (bretazenil), and a BDZ1 selective (zolpidem) receptor ligand were examined in the open field test (OFT) of neophobia and Vogel's test (VT) of conflict behavior in rats. Moreover, the influence of local injections of a noncompetitive GABA(A) receptor antagonist, picrotoxin, on the anxiolytic-like effect of serotonin (5-HT) depletion (p-chlorophenylalanine, p-CPA) in the Vogel test was studied. It was found that in the OFT only midazolam (0.1 microg/site) given to the hippocampus (HP) disinhibited rat exploratory behavior, whereas all the examined compounds inhibited animal motor activity when injected locally at 10.0 microg/site, the highest dose used in the tests. In the VT, again, only midazolam disinhibited rat conflict behavior on a dose-dependent basis. Picrotoxin administered to the HP produced a tendency to increase locomotor activity in rats, and significantly attenuated the anti-conflict action of serotonin depletion without changing the pain threshold and spontaneous drinking of the animals. p-CPA induced potent, dose-dependent and selective 5-HT and 5-hydroxyindoleacetic acid decrease in the HP after administering the dose used in the behavioral experiment. Thus, the present data provide evidence for the lack of selective anxiolytic activity of a partial non-selective agonist and a full selective agonist at the BDZ1 receptor after their administration to the HP. The model of intra-HP drug injections appeared effective in discriminating the anxiolytic spectrum of activity of new psychotropic compounds. Moreover, the obtained results indicate that the dorsal HP is one of the central sites important for GABA/5-HT interaction that modulates rat emotional behavior.

Benzodiazepine-GABAA receptor complex ligands in two models of anxiety

In the present study, the actions of several compounds with different intrinsic activities and BDZ receptor selectivity were examined in two well established animal models of anxiety: the open field test (OFT) and Vogel's punished drinking text (VT). Full agonists at the BDZ GABAA receptor (midazolam and diazepam) showed anxiolytic-like effects in both tests; however, the doses necessary to disinhibit animal behavior controlled by fear were higher in the VT than in the OFT. None of the partial BDZ receptor agonists studied (bretazenil, Ro 19-8022 and abecarnil) diminished neophobia-like behavior of rats in the OFT, and their sedative influence on gross behavior prevailed. On the other hand, all three drugs produced a clear-cut anxiolytic effect in the VT. A selective BDZ, receptor subtype full agonist (zolpidem) had a similar profile of action to that of partial agonists with an even stronger sedative effect in the OFT. Alpidem (a selective BDZ1 receptor partial agonist) did not reveal any anxiolytic action in either test. Flumazenil (an antagonist at the BDZ-GABAA receptors) also produced no effect in the OFT, or the VT. An inverse BDZ receptor agonist, beta-carboline-3-carboxylate methyl ester (beta-CCM), evoked an anxiogenic-like response in the OFT, but not in the VT. In summary, it appeared that partial agonists and selective ligands at BDZ1 receptors revealed less advantageous anxiolytic-like action than did full allosteric GABAA receptor modulators. This study also indicates the test dependent profiles of action of BDZ-GABAA receptor ligands. It also indirectly suggests a different neurobiological background underlying the applied tests.

Central serotonergic system and mechanism of anxiolytic action

The results clearly indicate that the hippocampus, rather than nucleus accumbens is involved in mediating anxiolytic-like effects of the 5-HT1A receptor agonists. Furthermore, hippocampal postsynaptic 5-HT1A receptors may account for the anti-emotional influence of this groups of drugs. As far as the 5-HT3 receptor antagonists are concerned, it was more difficult to localize their central anti-anxiety like action. More clear and unequirocal effects could be observed after intra-accumbens, rather than after intrahippocampal injections of tropisetron and ondansetron.

The hippocampus--the key structure in processing of emotional input in the central nervous system

Gray's conception hypothesizes that anxiolytics act indirectly to impair the behavioural inhibition system through GABA-ergic modulation of the ascending NA and 5-HT pathways to the hippocampus. The obtained results support this theory.

Anxiolytic activity of glycine-B antagonists and partial agonists--no relation to intrinsic activity in the patch clamp

On the basis of animal models, anxiety was one of the first suggested clinical applications of partial agonists of the glycineB site coupled to the NMDA receptor. It is not certain, however, whether these findings can be extended to full glycineB antagonists and what is the relation between intrinsic activity (degree of NMDA receptor antagonism) and anxiolytic effect. In the present study several NMDA receptor antagonists, including several glycineB antagonists/partial agonists, were tested for anxiolytic activity in the Vogel conflict test and the elevated plus-maze. Additionally, the intrinsic activities of the glycineB partial agonists used [ACPC, (R,+)-HA-966 and D-cycloserine] were compared in patch-clamp experiments in cultured neurones. In the plus-maze the most striking increase in the time spent in open arms (index of anxiolytic effect) was seen after diazepam and D-cycloserine (at doses that did not change locomotion). Also reliable (dose-dependent), although weaker, anxiolytic activity was produced by the uncompetitive NMDA receptor antagonist (+)MK-801 and the competitive antagonist CGP 39551. Modest anxiolytic-like effect in the plus-maze was also observed after the glycineB antagonist L-701,324 and the partial agonist (+,R)-HA-966. Uncompetitive antagonists memantine and amantadine, the glycineB partial agonist ACPC (up to 600 mg/kg) or the full antagonists MRZ 2/570, MRZ 2/571 and MRZ 2/576 had no effect. In the Vogel conflict test neither memantine, nor any of the full glycineB antagonists tested (L-701,324 and MRZ 2/576), showed anxiolytic activity. Patch-clamp studies revealed that the intrinsic activity of (+,R)-HA-966, D-cycloserine and ACPC was 13, 57 and 92%, respectively, as compared to that of glycine itself (100%). In conclusion, for the agents tested there is no clear relation between the levels of intrinsic activity, i.e. degree of NMDA receptor inhibition, and anxiolytic activity. Moreover, L-701,324 and MRZ-type glycineB full antagonists do not exchibit anxiolytic activity in the elevated plus-maze and Vogel conflict test.

The behavioral effects of NMDA antagonists in serotonin depleted rats

The influence of serotonin (5-HT) depletion (5,7-dihydroxytryptamine, 5,7-DHT, 250.0 micrograms, ICV), on behavioral effects of non-competitive (MK-801) and competitive (CGP 37849) NMDA antagonists, was examined in rats. 5,7-DHT induced very potent and long lasting decrease in the 5-HT concentration in the brainstem and limbic forebrain. One week after 5,7-DHT administration, dopamine metabolism was found enhanced in the brainstem. The lesion did not change rat baseline motor and exploratory activity, but it significantly disinhibited animals' behavior suppressed by shock, in the Vogel test. Serotonin depletion revealed locomotor stimulating effect of MK-801, administered IP at the doses of 0.05 and 0.2 mg/kg. However, no change in striatal dopamine metabolism was detected in rats injected with the same dose of MK-801 (0.2 mg/kg), and examined one week after serotonergic denervation. Serotonergic lesions antagonized both enhancements of exploratory behavior, and motor suppression produced by the dose of 1.0 and 10.0 mg/kg of CGP 37849, respectively. Thus, 5,7-DHT-induced lesions influenced in a complex way the effects of NMDA antagonists. It is reasoned, that enhancement of motor stimulating effects of MK-801 in neurotoxin pretreated animals, reflects synergistic disinhibition of activity of dopaminergic neurons by MK-801 and serotonin depletion. On the other hand, antagonism of CGP 37849-caused motor depression can be explained by the lowering influence of 5,7-DHT on serotonin content. It is known that the release of serotonin is strongly stimulated by higher doses of CGP 37849, and takes part in the expression of some symptoms of the serotonin-like syndrome, including motor disturbances.

The effects of repeated administration of diazepam, MK-801 and CGP 37849 on rat behavior in two models of anxiety

The effects of repeated administration of diazepam, MK-801 and CGP 37849 on rat behavior in the Vogel conflict test, and in the open field test of neophobia, were studied in rats. The drugs were given at doses active acutely, for 5 days, the last dose was administered 30 or 60 min prior to testing. It appeared that diazepam and MK-801 treated animals showed clear-cut signs of behavioral tolerance and motor sensitization, respectively. CGP 37849 was characterized by the best pharmacological profile, in that on repeated administration the drug not only retained its anxiolytic-like potency in the Vogel test, but even enhanced rat exploratory behavior in a new environment, independently of changes in animal motor activity. Repeated injections of the examined agents did not cause any significant modifications in monoamine levels and their turnover rates, in the striatum and limbic forebrain. It is concluded that the new class of competitive NMDA receptor antagonists, exemplified by CGP 37849, is the most promising candidate for clinical trials in anxiety disorders.

Antagonism of behavioral effects of electroconvulsive shock but not those of desipramine by the selective 5-HT-3 receptor antagonist, ondansetron

The influence of ondansetron (ON) on desipramine (DMI) and electroconvulsive shock (ECS) effects in the open field (OFT) and forced swim test (FST) were studied in Wistar male rats. ON failed to influence the action of DMI but abolished stimulatory effect of ECS in the OFT and, in the lower dose (0.01 mg/kg) reduced ECS action in the FST. This result suggests that 5-HT-3 receptors are involved in behavioral effects of ECS but not DMI.

Anxiolytic-like action of intra-hippocampally administered NMDA antagonists in rats

The effects of intra-hippocampally administered NMDA receptor antagonists MK-801, and AP-7 on rat behavior in the Vogel's and open field tests of anxiety were examined. MK-801 and AP-7 given locally stimulated at the same time rat exploratory and motor activities, in the open field. In the Vogel's test, both compounds attenuated the suppressive effect of shock on drinking, in a dose-range not affecting rat motility. It is concluded that hippocampal NMDA innervation may play a role in the control of motor activity. Furthermore, the Vogel's test data indicate more selective involvement of hippocampal NMDA innervation in processing of fear-related signals.

Effects of antagonists at the NMDA receptor complex in two models of anxiety

The effects of an antagonist at the strychnine insensitive glycine site (5,7-dichlorokynurenic acid, i.c.v.), and of noncompetitive (MK-801, i.p.) and competitive (CGP 37849, i.p.; CGP 39551, i.p.; AP-7, i.c.v.) NMDA antagonists were compared with diazepam (i.p.) in two animal models of anxiety (the open field exploratory behavior of non-habituated rats, and the Vogel conflict test). All drugs when applied in appropriate doses increased punished drinking in the Vogel test, without producing any significant changes in free drinking and the stimulus threshold at their lowest anticonflict doses. The effective doses were as follows: diazepam 1.5 and 2.5 mg/kg; MK-801 0.005 and 0.01 mg/kg; CGP 39551 5.0 and 20.0 mg/kg; CGP 37849 1.0 and 2.5 mg/kg; 5,7-dichlorokynurenic acid 5.0 microgram (i.c.v.); AP-7 0.5 microgram (i.c.v.). In the open field diazepam (0.05 mg/kg), MK-801 (0.1 mg/kg), CGP 37849 (0.01, 0.1, 1.0 mg/kg), and AP-7 2.5 micrograms (i.c.v.) significantly increased exploratory activity in the central sectors of the open field (anti-neophobic reaction), without changing motor activity of the rat. MK-801 at the highest tested dose of 0.2 mg/kg significantly stimulated animal locomotor activity. CGP 37849 in the largest dose examined (10 mg/kg) significantly depressed the motor behavior of rats. Overall, it appeared that different NMDA antagonists showed an anxiolytic-like profile, similar to that of the benzodiazepine diazepam. Among different NMDA receptor complex antagonists studied, CGP 37849 was characterized by the largest distinction between the doses showing an anxiolytic-like action in the open field test, and changing rat motor behavior.

Antidepressant treatment and limbic serotonergic mechanisms regulating rat locomotor activity

The effects of chronic administration of desipramine, citalopram, and electroconvulsive shocks (ECS) on changes in rat motility after intraaccumbens (NAS) injections of selective serotonergic drugs were studied in intact and 5.7-DHT lesioned animals. It was shown that local injections of 8-OHDPAT and DOI-HCl depressed rat locomotor activity. Their effects appeared to be mediated postsynaptically, and could be antagonized by NAN-190 and ritanserin, respectively. Chronic but not acute pretreatment of rats with antidepressants (21 days long; the experiment was performed 24 h after the last dose) as well as repeated ECS (shocks were applied five times every second day), antagonized behavioral depression after 8-OHDPAT and DOI-HCl. The influence of antidepressant treatment was prevented by serotonergic lesions. Chronic administration of antidepressants and ECS did not equivocally affect the levels or metabolism of 5-HT, dopamine, and noradrenaline in the rat limbic forebrain. It is concluded that the present data indicate diminished activity of 5-HT systems related to the 5-HT1A and 5-HT2 receptors in the limbic nucleus, after chronic antidepressant treatment. This effect of drugs and ECS concerns nervous processes linked with the function of postsynaptically localized 5-HT receptor subtypes, and it probably depends on intact presynaptic 5-HT innervation.

The effect of serotonin depletion and intra-hippocampal midazolam on rat behavior in the Vogel conflict test

The effect of intra-hippocampal (dentate gyrus) microinjections of the benzodiazepine, midazolam (10 micrograms per site, bilaterally), was examined in the Vogel conflict test in serotonin depleted rats (pretreated with p-chlorophenylalanine). p-Chlorophenylalanine and midazolam, when given separately, significantly disinhibited rat conflict behavior. Midazolam retained its anticonflict potency in the p-chlorophenylalanine pretreated animals. These and other data indicate: (i) the specific involvement of limbic serotonin in emotional control, (ii) a dissociation of the effects of serotonin depletion and intra-hippocampal benzodiazepine on conflict behavior, and (iii) the important role of the hippocampus in processing emotional input.

Studies on antidepressant action of a new oxazolidinone derivative AS-8

On the basis of previous laboratory studies AS-8 was suggested to possess antidepressant-like activity. Forced swim test, learned helplessness and conflict Vogel's test were performed after three prior administrations of AS-8 (24, 5 and 1 h before the test). The data have shown that AS-8 produces moderate antidepressant effect but did not induce anxiolytic-like action. Biochemical data revealed increased brain 5-HT and 5-HIAA levels following AS-8 administration. The combined treatment of rats with AS-8 (100 mg/kg) and amitriptyline (5 mg/kg) or desipramine (1.25 mg/kg) significantly stimulated active behavior in the forced swim test above the level obtained with each of the drug given separately. The present data suggest the potential antidepressant efficacy of AS-8 in conjunction with small doses of tricyclic antidepressants.

Toxicity of flavoglaucin from Aspergillus chevalieri in rabbits

Female rabbits were injected intraperitoneally (i.p.) with purified flavoglaucin from Aspergillus chevalieri. After 2 h the rabbits were bled and the livers removed for enzyme assays. No changes were found for plasma lactate dehydrogenase (LDH) and its isozymes or liver transketolase (TK) activities. A small but not statistically significant increase was found in plasma glutamate pyruvate transaminase activity. A highly significant increase in plasma glutamic oxaloacetate transaminase activity was observed along with an increase in liver LDH which was, however, not quite significant. The liver also showed some histological evidence of hepatic damage.

Streptomyces maghwi, a new species producing roflamycoin

A new Streptomyces species is described for which the name S. maghwi is proposed. The organism is characterized by a pink mass of aerial mycelium, spiral spore chains, spores with smooth surfaces and a nonchromogenic vegetative mycelium. S. maghwi produces roflamycoin (Schlegel et al. 1981) formerly known as flavomycoin (Schlegel et al. 1971). The type strain of S. maghwi is deposited with CBS, Netherland.