The role of psychosis and clozapine load in excessive checking in treatment-resistant schizophrenia: longitudinal observational study

BACKGROUND

A significant proportion of people with clozapine-treated schizophrenia develop 'checking' compulsions, a phenomenon yet to be understood.

AIMS

To use habit formation models developed in cognitive neuroscience to investigate the dynamic interplay between psychosis, clozapine dose and obsessive-compulsive symptoms (OCS).

METHOD

Using the anonymised electronic records of a cohort of clozapine-treated patients, including longitudinal assessments of OCS and psychosis, we performed longitudinal multi-level mediation and multi-level moderation analyses to explore associations of psychosis with obsessiveness and excessive checking. Classic bivariate correlation tests were used to assess clozapine load and checking compulsions. The influence of specific genetic variants was tested in a subsample.

RESULTS

A total of 196 clozapine-treated individuals and 459 face-to-face assessments were included. We found significant OCS to be common (37.9%), with checking being the most prevalent symptom. In mediation models, psychosis severity mediated checking behaviour indirectly by inducing obsessions (r = 0.07, 95% CI 0.04-0.09; P < 0.001). No direct effect of psychosis on checking was identified (r = -0.28, 95% CI -0.09 to 0.03; P = 0.340). After psychosis remission (n = 65), checking compulsions correlated with both clozapine plasma levels (r = 0.35; P = 0.004) and dose (r = 0.38; P = 0.002). None of the glutamatergic and serotonergic genetic variants were found to moderate the effect of psychosis on obsession and compulsion (SLC6A4, SLC1A1 and HTR2C) survived the multiple comparisons correction.

CONCLUSIONS

We elucidated different phases of the complex interplay of psychosis and compulsions, which may inform clinicians' therapeutic decisions.

Advances in Cryopreservatives: Exploring Safer Alternatives

Cryopreservation of cells, tissues, and organs is widely used in the biomedical and research world. There are different cryopreservatives that are used for this process; however, many of them, such as DMSO, are used despite the problems they present, mainly due to the toxicity it presents to certain types of samples. The aim of this Review is to highlight the different types of substances used in the cryopreservation process. It has been shown that some of these substances are well-known, as in the case of the families of alcohols, sugars, sulfoxides, etc. However, in recent years, other compounds have appeared, such as ionic liquids, deep eutectic solvents, or certain polymers, which open the door to new cryopreservation methods and are also less toxic to frozen samples.

Importance of Pharmacogenetics and Drug-Drug Interactions in a Kidney Transplanted Patient

Tacrolimus (TAC) is a narrow-therapeutic-range immunosuppressant drug used after organ transplantation. A therapeutic failure is possible if drug levels are not within the therapeutic range after the first year of treatment. Pharmacogenetic variants and drug-drug interactions (DDIs) are involved. We describe a patient case of a young man (16 years old) with a renal transplant receiving therapy including TAC, mycophenolic acid (MFA), prednisone and omeprazole for prophylaxis of gastric and duodenal ulceration. The patient showed great fluctuation in TAC blood concentration/oral dose ratio, as well as pharmacotherapy adverse effects (AEs) and frequent diarrhea episodes. Additionally, decreased kidney function was found. A pharmacotherapeutic follow-up, including pharmacogenetic analysis, was carried out. The selection of the genes studied was based on the previous literature (CYP3A5, CYP3A4, POR, ABCB1, PXR and CYP2C19). A drug interaction with omeprazole was reported and the nephrologist switched to rabeprazole. A lower TAC concentration/dose ratio was achieved, and the patient's condition improved. In addition, the TTT haplotype of ATP Binding Cassette Subfamily B member 1 (ABCB1) and Pregnane X Receptor (PXR) gene variants seemed to affect TAC pharmacotherapy in the studied patient and could explain the occurrence of long-term adverse effects post-transplantation. These findings suggest that polymorphic variants and co-treatments must be considered in order to achieve the effectiveness of the immunosuppressive therapy with TAC, especially when polymedicated patients are involved. Moreover, pharmacogenetics could influence the drug concentration at the cellular level, both in lymphocyte and in renal tissue, and should be explored in future studies.

Ecotoxicity interspecies study of ionic liquids based on phosphonium and ammonium cations

This work studies the effects of different bromide-based ionic liquids, with phosphonium and ammonium cations, towards several environmental biomodels: Daphnia magna, Allivibrio fischeri, Raphidocelis subcapitata. Results indicate that toxicity clearly depends on the biomodel, Allivibrio fischeri being the least sensitive one while Daphnia magna is more severely affected in the presence of the studied ionic liquids. In most of the cases, phosphonium moieties are less toxic than ammonium ionic liquids. Furthermore, a prediction about the oral toxicity and carcinogenicity of the studied ionic liquids has been also carried out, showing that these chemical structures may suggest significant toxicity but not present genotoxic or nongenotoxic carcinogenicity.

Quantifying the economic impact of caregiving for Duchenne muscular dystrophy (DMD) in Spain

AIM

To establish the potential economic burden in caregivers to patients with DMD and the potential causative factors.

METHOD

Caregivers to patients with DMD were recruited through the DMD patients Register and questioned about several economic aspects using "ad-hoc" questionnaires.

RESULTS

All families, apart from one (97.2% n = 36), incurred in monthly medical costs (44% of the families more than 50 euros/month). 97.2% of the households considered looking after a patient of DMD as financially burdensome, and 80.5% of households declared to have suffered work changes, especially the mothers (job timetable-related mainly). The presence of obsessive-compulsive disorders (OCD) in patients was significantly associated with caregivers' high financial burden as these were six times more likely to have this perception OR = 6468 IC 95% (1056-39,601), p = 0.043. Also, when patients had learning difficulties, caregivers had up to six times more chances to incur in monthly expenditure for formal care OR = 6089 IC 95% (1112-33,342), p = 0.037.

INTERPRETATION

Caregivers have relevant financial burden that might be conditioned by the clinical condition of the patient.

WHAT THIS PAPER ADDS

Quantitative data about financial burden in DMD Spanish families providing informal care. Identification of the patient's main clinical issues associated with financial burden.

QSAR modelling for predicting the toxic effects of traditional and derived biomass solvents on a Danio rerio biomodel

The increasing interest in the development of ecofriendly solvents has led to the synthesis of benign alternative chemicals with minimized environmental impacts. These kinds of chemicals are known as Green solvents. In this work, we selected three families of solvents (furfural, lactate and levulinate families) derived from biomass that are structurally related. Most of the previous ecotoxicological studies of these solvents have focused on invertebrate models such as bacteria, algae and crustaceans. To complete this information, in this work, the acute toxicity of these solvents was studied in Danio rerio (D. rerio). Sublethal and lethal effects were also observed, and the LC₅₀ was obtained. The LC₅₀ values ranged from 13.21 to 12073 mg L^-1, with furfural being the most toxic compound and tetrahydrofurfuryl alcohol the least toxic. Furthermore, the results indicated that a frequent sublethal effect was heart oedema or malformation, even in some cases at concentrations lower than the LC₅₀. A QSAR analysis was also performed to model the toxicological effect towards D. rerio for the studied solvents obtained from biomass and traditional solvents. A total of 15 molecular descriptors of the solvents were obtained using Gaussian 03 software. Finally, we also used the physicochemical property Log P, calculated from ACD/LogP, for QSAR modelling. Multivariable regression analysis showed that the minimum set of independent variables that leads to the best regression is Log P, the energy of the lowest unoccupied molecular orbital (ELUMO) and the heat capacity (CV). The proposed model was validated using several internal and external methods.

Acute and subacute effects of drugs in embryos of Danio rerio. QSAR grouping and modelling

The final fate of many drugs is release into the natural aquatic environment. It is necessary to assess the toxicity caused by this situation and the associated concerns for human beings. Zebrafish (Danio rerio) is a common biomodel used to assess toxicity in aquatic environments. The zebrafish embryo toxicity test was selected to evaluate the acute toxicity of several drugs (diphenhydramine, gentamicin, tobramycin, enalapril and lidocaine) due to the lack of such information. Lethal and sublethal effects were detected, and the LC₅₀ values of the drugs ranged from 11.0 mg/L to 422·10² mg/L. For all of the drugs tested, these values were higher than the concentrations found in the natural environment. Therefore, there was a low environmental toxicological risk. Nevertheless, teratogenic effects were also recorded when embryos of zebrafish were exposed to caffeine (control drug), diphenhydramine and lidocaine at lower concentrations than the respective LC₅₀ values. Quantitative structure-activity relationship analysis was also performed to analyse these drugs and other chemicals with pharmaceutical uses as well as previous toxicological data in this vertebrate after 48 h of exposure. It is estimated that the partition coefficient, log P, is the main physicochemical property related to the ecotoxicological data and can be used for the development of a mathematical model.

Exploring the usefulness of key green physicochemical properties: Quantitative structure-activity relationship for solvents from biomass

In recent decades there has been a growing interest in the development of new solvents from biomass. Some of these new solvents have been classified as green because of their renewable and sustainable source. However, characterization from the ecotoxicological and physicochemical points of view is needed to categorize them as green solvents. We have selected several key physicochemical properties that can reflect environmental features (density, boiling point, critical aggregation concentration, and log p) and explored their usefulness for preliminarily assessing the green character of the studied solvents. Specifically, we have studied several solvents from biomass: lactate family (methyl, ethyl, and butyl lactate), furfural family (furfural, 5-methylfurfural, furfuryl alcohol, and tetrahydrofurfuryl alcohol), and levulinate family (methyl, ethyl, and butyl levulinate). To fill the gaps and complete some toxicity data for the environment, we have measured the ecotoxicity using 2 of the most common and versatile biomodels, bacteria Vibrio fischeri and crustacean Daphnia magna, for furfural- and lactate-derived compounds. The results indicate that solvents from biomass can be categorized as green because their toxicity for the environment is low. Finally, a quantitative structure-activity relationship (QSAR) study was performed with the selected key properties and the ecotoxicological information. Despite the different structure of the chemicals under study, good correlations were found for the studied organisms. It seems that log p and critical aggregation concentration reflect the greatest part of the ecotoxic behavior, whereas density and boiling point cannot reflect toxicity signals. However, these properties are rather useful for assessing the final environmental fate of the studied chemicals. Environ Toxicol Chem 2018;37:1014-1023. © 2017 SETAC.

The present Pyrenean population of bearded vulture (Gypaetus barbatus): its genetic characteristics

The Pyrenean population of the endangered bearded vulture (Gypaetus barbatus) is the largest natural population in Europe. In this study, its current genetic variability was assessed using 110 animals of the recent population in order to know what the present situation. Sex identification by DNA methodology in the 110 bearded vultures, mitochondrial DNA (mtDNA) and eight microsatellite markers in 87 bearded vultures have been analysed. Our results for sex identification present a number of 49 males and 61 females; no significant differences for number of males and females in this population have been observed. mtDNA studies indicate that nucleotide and haplotype diversities and number of variable sites were low. Tajima's D test and Fu and Li's D* and F* tests suggest that mutations are selectively neutral and the population is expanding. A mean number of alleles per locus and a mean observed heterozygosity have been obtained by microsatellite analysis. FIS is not high, and inbreeding depression could be discarded in the near future. The results suggest that the Pyrenean population of bearded vultures have to be controlled in order to avoid the loss of genetic variability. This data should be taken into account when considering conservation plans for the species.

[Epidemiological aspects of ciprofloxacin-resistant Escherichia coli at a general hospital]

The susceptibility to ciprofloxacin of 7288 Escherichia coli clinical isolates from 5667 patients was determined over a 4-year period (1995-1998). Information about the patients' age, sex, specimen type, date, origin and susceptibility to Escherichia coli isolates was studied, and the c2 test was used for statistical comparison. Overall, 1003 (17.70&#37;) patients out of the 5667 included in the study presented ciprofloxacin resistance. The annual resistance observed over this 4-year period was not considered statistically significant. The resistant isolates were more frequent among men, in urine specimens and in outpatients, and increased with different age groups. The average age of patients with resistant isolates was 61.29 years (SD 21.56) and that of patients with susceptible isolates was 39.76 years (SD 27.41). A similar rate of resistance was observed among outpatients from health centers and those from hospital outpatient services. The higher resistance rates were found in outpatients from the urology department. The resistance to other fluoroquinolones remained the same and was not significant for norfloxacin; it increased starting from 1997 for pefloxacin at the expense of ciprofloxacin-sensitive isolates.

Percutaneous transluminal angioplasty in patients with Takayasu arteritis: five-year experience

PURPOSE

The authors report their 5-year experience with percutaneous transluminal angioplasty (PTA) for treatment of stenoses related to Takayasu arteritis.

PATIENTS AND METHODS

Twenty patients were treated; 12 patients had renovascular hypertension at presentation, three patients had abdominal aortic coarctation syndrome, and five patients had aortoiliac occlusive disease.

RESULTS

The initial success rate for patients with renovascular hypertension was 83%, with a 5-year patency of 33.3%. In patients with abdominal aortic coarctation, initial success rate was 100% but 5-year patency was 33.3%. In patients with aortoiliac occlusive disease, the initial success rate was 100%, with a 5-year patency of 60%.

CONCLUSION

Despite the high initial success rate for PTA in these patients, the disease recurs in a substantial number of the, due to the fact that this technique does not treat the disease itself but only its consequences.