Is Clozapine-induced Weight Gain Dose-dependent? Results From a Prospective Cohort Study

BACKGROUND

Antipsychotic-induced metabolic adverse effects are risk factors for cardiometabolic comorbidities. Whether dose lowering could mitigate such effects remains unclear. The present study aims to investigate the associations between clozapine doses and modifications of weight, blood pressure, blood glucose, and lipid levels.

STUDY DESIGN

Linear mixed-effects models of weight changes over 1 year and of variations of other metabolic parameters over 4 months were applied to a prospective cohort of 115 patients. Age- and sex-stratified analyses of weight changes were also performed.

STUDY RESULTS

Each 100 mg dose increment of clozapine was associated on average with a +0.48% weight increase (P = .004) over 1 year of treatment. Weight increase was greater for treatment duration ≤3 vs >3 months (+0.84% and +0.47% per month, respectively, P < .001), with a significant association with the dose for durations >3 months (+0.54%, P = .004) and a trend for durations ≤3 months (+0.33%, P = .075). Dose increments of 100 mg were also associated with weight increases of +0.71% among adults (P = .001), +1.91% among the elderly (P < .001) and +1.32% among men (P < .001) with no associations among women (P = .62). Among young adults, weight change was positively associated with doses ≤300 mg/day (+2.19% per 100 mg, P = .001), whereas no association was found with doses >300 mg/day (P = .60). No significant effect of clozapine dose on other metabolic parameters was found.

CONCLUSIONS

This study reports a modest effect of clozapine dose increases on weight gain over 1 year with differences among age categories and sexes and no dose effect on other metabolic parameters over 4 months.

Sevoflurane dose and postoperative delirium: a prospective cohort analysis

BACKGROUND

Recent trials are conflicting as to whether titration of anaesthetic dose using electroencephalography monitoring reduces postoperative delirium. Titration to anaesthetic dose itself might yield clearer conclusions. We analysed our observational cohort to clarify both dose ranges for trials of anaesthetic dose and biological plausibility of anaesthetic dose influencing delirium.

METHODS

We analysed the use of sevoflurane in an ongoing prospective cohort of non-intracranial surgery. Of 167 participants, 118 received sevoflurane and were aged >65 yr. We tested associations between age-adjusted median sevoflurane (AMS) minimum alveolar concentration fraction or area under the sevoflurane time×dose curve (AUC-S) and delirium severity (Delirium Rating Scale-98). Delirium incidence was measured with 3-minute Diagnostic Confusion Assessment Method (3D-CAM) or CAM-ICU. Associations with previously identified delirium biomarkers (interleukin-8, neurofilament light, total tau, or S100B) were tested.

RESULTS

Delirium severity did not correlate with AMS (Spearman's ρ=-0.014, P=0.89) or AUC-S (ρ=0.093, P=0.35), nor did delirium incidence (AMS Wilcoxon P=0.86, AUC-S P=0.78). Further sensitivity analyses including propofol dose also demonstrated no relationship. Linear regression confirmed no association for AMS in unadjusted (log (IRR)=-0.06 P=0.645) or adjusted models (log (IRR)=-0.0454, P=0.735). No association was observed for AUC-S in unadjusted (log (IRR)=0.00, P=0.054) or adjusted models (log (IRR)=0.00, P=0.832). No association of anaesthetic dose with delirium biomarkers was identified (P>0.05).

CONCLUSION

Sevoflurane dose was not associated with delirium severity or incidence. Other biological mechanisms of delirium, such as inflammation and neuronal injury, appear more plausible than dose of sevoflurane.

CLINICAL TRIAL REGISTRATION

NCT03124303, NCT01980511.

Dried Plum Consumption Improves Total Cholesterol and Antioxidant Capacity and Reduces Inflammation in Healthy Postmenopausal Women

Dried plums contain bioactive components that have demonstrated antioxidant and anti-inflammatory effects. The objective of this study was to determine if dried plum consumption reduces the risk factors for cardiovascular disease (CVD) in postmenopausal women, specifically examining lipid profiles, oxidative stress, antioxidant capacity, and inflammation in a dose-dependent manner. We conducted a 6-month, parallel-design controlled clinical trial, where 48 postmenopausal women were randomly assigned to consume 0, 50, or 100 g of dried plum each day. After 6 months of intervention, total cholesterol (TC) in the 100 g/day treatment group (P = .002) and high-density lipoprotein cholesterol in the 50 g/day treatment group (P = .005) improved significantly compared to baseline. Inflammatory biomarkers interleukin-6 (P = .044) and tumor necrosis factor-α (P = .040) were significantly lower after 6 months within the 50 g/day dried plum group compared to baseline. Moreover, total antioxidant capacity increased significantly within the 50 g/day group (P = .046), and superoxide dismutase activity increased significantly within both 50 and 100 g/day groups (P = .044 and P = .027, respectively) after 6 months compared to baseline. In addition, plasma activities of alanine transaminase (P = .046), lactate dehydrogenase (P = .039), and creatine kinase (P = .030) were significantly lower after 6 months in the 50 g/day dried plum group. These findings suggest that daily consumption of 50-100 g dried plum improves CVD risk factors in postmenopausal women as exhibited by lower TC, oxidative stress, and inflammatory markers with no clear dose dependence.

The long-term effects of γ-radiation on the growth of Allium cepa plants

PURPOSE

The purpose of this study was to assess the long-term effects of gamma-radiation, including low-dose radiation, on growth parameters of onion (Allium cepa) seedling roots 6-10 days after irradiation.

MATERIALS AND METHODS

Onion seedlings were exposed to a ¹³⁷Cs gamma source at doses ranging from 0.1 to 10 grays (Gy). Responses of root and shoot length growth were studied 6 and 10 days after irradiation.

RESULTS

Our results showed inhibition of the root and shoot length growth 6 days after exposure at all doses, including the low dose - 0.1 Gy. At a later point in time (day 10), root and shoot inhibition was only observed after irradiation at high doses (above 5 Gy), and that suggested the occurrence of cell repair after irradiation at low doses. The results indicated that the length of seedling roots was more sensitive to gamma-irradiation than the shoot length.

CONCLUSION

The results of the study suggested that short-term gamma-irradiation of onion seedlings (absorbed doses of 0.1-10 Gy) caused inhibition of plant growth 6 and 10 days after irradiation. The dose dependence of the onion root length was linear. The present study showed for the first time that short-term low-dose gamma-irradiation could induce long-term negative effects on plant growth.

In vitro toxicity assessment of respirable solid surface composite sawing particles

Solid surface composites (SSCs) are a class of popular construction materials composed of aluminum trihydrate and acrylic polymers. Previous investigations have demonstrated that sawing SSC releases substantial airborne dusts, with a number-based geometric mean diameter of 1.05 µm. We reported that in mice, aspiration exposure to airborne SSC dusts induced symptoms of pulmonary inflammation at 24-h postexposure: neutrophilic influx, alveolitis, and increased lactate dehydrogenase (LDH) and pro-inflammatory cytokine levels in lavage fluid. The particles appeared to be poorly cleared, with 81% remaining at 14-day postexposure. The objective of this study was to determine the toxicity specifically of respirable particles on a model of human alveolar macrophages (THP-1). The relative toxicities of subfractions (0.07, 0.66, 1.58, 5.0, and 13.42 µm diameter) of the airborne particles were also determined. THP-1 macrophages were exposed for 24 h to respirable particles from sawing SSC (0, 12.5, 25, 50, or 100 µg/ml) or size-specific fractions (100 µg/ml). Exposure to respirable SSC particles induced THP-1 macrophage toxicity in a dose-dependent manner. Viability was decreased by 15% and 19% after exposure to 50 and 100 µg/ml SSC, respectively, which correlated with increased cell culture supernatant LDH activity by 40% and 70% when compared to control. Reactive oxygen species (ROS) production and inflammatory cytokines were increased in a dose-dependent manner. A size-dependent cytotoxic effect was observed in the cells exposed to subfractions of SSC particles. SSC particles of 0.07, 0.66, and 1.58 µm diameter killed 36%, 17%, and 22% of cells, respectively. These results indicate a potential for cytotoxicity of respirable SSC particles and a relationship between particle size and toxicity, with the smallest fractions appearing to exhibit the greatest toxicity.

Dose dependency of γ-H2AX formation in the rat urinary bladder treated with genotoxic and nongenotoxic bladder carcinogens

We previously reported that immunostaining for γ-H2AX, a biomarker of DNA damage, in the rat urinary bladder is useful for early detection of bladder carcinogens in 28-day toxicity studies. Here, we aimed to examine the dose dependency of γ-H2AX formation in the urinary bladder of rats. Male F344 rats (aged 6 weeks) were orally administered N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN; 0%, 0.0001%, 0.001%, 0.01%, 0.02%, or 0.05% in drinking water), a genotoxic bladder carcinogen, and melamine (0%, 0.3%, 1.0%, or 3.0% in the diet), a nongenotoxic bladder carcinogen, for 2 days or 4 weeks. Immunohistochemical analysis showed that γ-H2AX- and Ki67-positive epithelial cells in the bladder urothelium were significantly increased, with a clear dose dependency, in both BBN- and melamine-treated groups. Additionally, γ-H2AX formation was detected from the lower-dose group, without increased Ki67 expression or histopathologic findings. The ratios of γ-H2AX-positive cells at week 4 in both BBN- and melamine-treated groups were higher than those on day 2, indicating the time-dependent increase in γ-H2AX formation. Immunofluorescence double-staining revealed that γ-H2AX single-positive cells without Ki67 expression were often found in the urothelium of BBN-treated rats, whereas most γ-H2AX-positive cells were Ki67-positive in the melamine group. Our results demonstrated that γ-H2AX formation in the urinary bladder increased in a clear dose-dependent manner and that γ-H2AX immunostaining has the potential to detect bladder carcinogens after a 2-day administration. Furthermore, the association of genotoxic mechanisms in bladder carcinogenesis could be determined by analyzing the colocalization of γ-H2AX and Ki67 in the urothelium.

Cardiotoxicity of mitoxantrone treatment in a german cohort of 639 multiple sclerosis patients

Background and Purpose

The aim of this study was to elucidate the role of therapy-related cardiotoxicity in multiple sclerosis (MS) patients treated with mitoxantrone and to identify potential predictors for individual risk assessment.

Methods

Within a multicenter retrospective cohort design, cardiac side effects attributed to mitoxantrone were analyzed in 639 MS patients at 2 MS centers in Germany. Demographic, disease, treatment, and follow-up data were collected from hospital records. Patients regularly received cardiac monitoring during the treatment phase.

Results

None of the patients developed symptomatic congestive heart failure. However, the frequency of patients experiencing cardiac dysfunction of milder forms after mitoxantrone therapy was 4.1% (26 patients) among all patients. Analyses of the risk for cardiotoxicity revealed that cumulative dose exposure was the only statistically relevant risk factor associated with cardiac dysfunction.

Conclusions

The number of patients developing subclinical cardiac dysfunction below the maximum recommended cumulative dose is higher than was initially assumed. Interestingly, a subgroup of patients was identified who experienced cardiac dysfunction shortly after initiation of mitoxantrone and who received a low cumulative dose. Therefore, each administration of mitoxantrone should include monitoring of cardiac function to enhance the treatment safety for patients and to allow for early detection of any side effects, especially in potential high-risk subgroups (as determined genetically).

Site-specific effects of testosterone propionate on the prostate of rat pretreated with 3,2'-dimethyl-4-aminobiphenyl: dose-dependent induction of invasive carcinomas

It has been shown that testosterone propionate (TP) strongly promotes induction of invasive carcinomas in previously initiated accessory sex organs. In this study, in order to clarify the dose-dependence of this promotion, TP was given at 3 different levels (high, medium or low doses) using different sizes (2, 1 and 0.5 cm long) of Silastic tube for 40 weeks after administration of 3,2'-dimethyl-4-aminobiphenyl to male F344 rats. The data showed development of invasive carcinomas in the dorso-lateral and anterior prostate and in the seminal vesicle to be dose-dependent with the high dose of TP being most effective for tumor induction. Average levels of serum testosterone were approximately 800, 600, 300 and 150 ng/dl in rats given the high to low doses and in control rats, respectively. Development of neoplastic lesions in the ventral prostate demonstrated an inverse dependence on the dose of TP. These findings, together with previous data, suggest that the tumor-promoting potential of TP on rat prostate is unlikely to be simply due to its androgenic action and other factors should also be considered.

Dose-dependent induction of liver and thyroid neoplastic lesions by short-term administration of 2-amino-3-methylimidazo[4,5-f]quinoline combined with partial hepatectomy followed by phenobarbital or low dose 3'-methyl-4-dimethylaminoazobenzene promotion

Dietary administration of 0.1, 0.05, or 0.025% 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) for two weeks combined with partial hepatectomy at the end of the first week and followed by long-term treatment with phenobarbital (PB) or 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB) from week 3 to week 86 resulted in dose-dependent development of liver and thyroid neoplastic and preneoplastic lesions. Quantitation of glutathione S-transferase placental form (GST-P)-positive hepatocellular focal populations revealed a significant correlation of IQ concentration with lesion area, with a yield approximately equal to that generated by a similar dose of 2-acetylaminofluorene. The fact that IQ was less toxic therefore allowed greater yields of hepatocellular carcinomas to be induced. The development of thyroid tumors initiated by the IQ treatment was significantly enhanced by the administration of PB, whereas Zymbal gland tumors induced by IQ did not show any correlation with either PB or 3'-Me-DAB treatment.