Search

Background: Microglial cell iron load and inflammatory activation are significant hallmarks of late-stage Alzheimer's disease (AD). In vitro, microglia preferentially upregulate the iron importer, divalent metal transporter 1 (DMT1, gene name Slc11a2) in response to inflammatory stimuli, and excess iron can augment cellular inflammation, suggesting a feed-forward loop between iron import mechanisms and inflammatory signaling. However, it is not understood whether microglial iron import mechanisms directly contribute to inflammatory signaling and chronic disease in vivo. These studies determined the effects of microglial-specific knockdown of Slc11a2 on AD-related cognitive decline and microglial transcriptional phenotype., Methods: In vitro experiments and RT-qPCR were used to assess a role for DMT1 in amyloid-β-associated inflammation. To determine the effects of microglial Slc11a2 knockdown on AD-related phenotypes in vivo, triple-transgenic Cx3cr1 Cre-ERT2 ;Slc11a2 flfl ;APP/PS1 +or - mice were generated and administered corn oil or tamoxifen to induce knockdown at 5-6 months of age. Both sexes underwent behavioral analyses to assess cognition and memory (12-15 months of age). Hippocampal CD11b+ microglia were magnetically isolated from female mice (15-17 months) and bulk RNA-sequencing analysis was conducted., Results: DMT1 inhibition in vitro robustly decreased Aβ-induced inflammatory gene expression and cellular iron levels in conditions of excess iron. In vivo, Slc11a2 KD APP/PS1 female, but not male, mice displayed a significant worsening of memory function in Morris water maze and a fear conditioning assay, along with significant hyperactivity compared to control WT and APP/PS1 mice. Hippocampal microglia from Slc11a2 KD APP/PS1 females displayed significant increases in Enpp2, Ttr, and the iron-export gene, Slc40a1, compared to control APP/PS1 cells. Slc11a2 KD cells from APP/PS1 females also exhibited decreased expression of markers associated with subsets of disease-associated microglia (DAMs), such as Apoe, Ctsb, Ly9, Csf1, and Hif1α., Conclusions: This work suggests a sex-specific role for microglial iron import gene Slc11a2 in propagating behavioral and cognitive phenotypes in the APP/PS1 model of AD. These data also highlight an association between loss of a DAM-like phenotype in microglia and cognitive deficits in Slc11a2 KD APP/PS1 female mice. Overall, this work illuminates an iron-related pathway in microglia that may serve a protective role during disease and offers insight into mechanisms behind disease-related sex differences., (© 2024. The Author(s).)

Background: Microglial cell iron load and inflammatory activation are significant hallmarks of late-stage Alzheimer's disease (AD). In vitro , microglia preferentially upregulate the iron importer, divalent metal transporter 1 (DMT1, gene name Slc11a2 ) in response to inflammatory stimuli, and excess iron can augment cellular inflammation, suggesting a feed-forward loop between iron import mechanisms and inflammatory signaling. However, it is not understood whether microglial iron import mechanisms directly contribute to inflammatory signaling and chronic disease in vivo . These studies determined the effects of microglial-specific knockdown of Slc11a2 on AD-related cognitive decline and microglial transcriptional phenotype., Methods: In vitro experiments and RT-qPCR were used to assess a role for DMT1 in amyloid-β-associated inflammation. To determine the effects of microglial Slc11a2 knockdown on AD-related phenotypes in vivo , triple-transgenic Cx3cr1 Cre - ERT2 ; Slc11a2 flfl ; APP/PS1 + or - mice were generated and administered corn oil or tamoxifen to induce knockdown at 5-6 months of age. Both sexes underwent behavioral analyses to assess cognition and memory (12-15 months of age). Hippocampal CD11b + microglia were magnetically isolated from female mice (15-17 months) and bulk RNA-sequencing analysis was conducted., Results: DMT1 inhibition in vitro robustly decreased Aβ-induced inflammatory gene expression and cellular iron levels in conditions of excess iron. In vivo , Slc11a2 KD APP/PS1 female, but not male, mice displayed a significant worsening of memory function in Morris water maze and a fear conditioning assay, along with significant hyperactivity compared to control WT and APP/PS1 mice. Hippocampal microglia from Slc11a2 KD APP/PS1 females displayed significant increases in Enpp2 , Ttr , and the iron-export gene, Slc40a1 , compared to control APP/PS1 cells. Slc11a2 KD cells from APP/PS1 females also exhibited decreased expression of markers associated with disease-associated microglia (DAMs), such as Apoe , Ctsb, Csf1 , and Hif1α ., Conclusions: This work suggests a sex-specific role for microglial iron import gene Slc11a2 in propagating behavioral and cognitive phenotypes in the APP/PS1 model of AD. These data also highlight an association between loss of a DAM-like phenotype in microglia and cognitive deficits in Slc11a2 KD APP/PS1 female mice. Overall, this work illuminates an iron-related pathway in microglia that may serve a protective role during disease and offers insight into mechanisms behind disease-related sex differences., Competing Interests: Competing Interests The authors declare that they have no competing interests.

Additional chromosome abnormalities (ACAs) occur in less than 10% of cases at diagnosis of Philadelphia chromosome (Ph)-positive chronic myelogenous leukemia (CML). In some cases, on the basis of the persistence of the ACAs in Ph-negative cells after response to imatinib, a secondary origin of the Ph chromosome has been demonstrated. In this study, the possible prognostic value of this phenomenon was evaluated. Thirty-six Ph-positive CML patients were included in the study. In six patients, ACAs persisted after the disappearance of the Ph. A complete cytogenetic response (CCR) was obtained in five of these six patients, and five of six also had a high Sokal score. In all the other cases, ACAs disappeared together (in cases of response to therapy with imatinib) or persisted with the Ph (in cases of no response to imatinib). In the former cases, the primary origin of the Ph was demonstrated. CCR was obtained in 22 cases (17 with low to intermediate Sokal scores), while no response was observed in 8 patients (5 with a high Sokal score). Sokal score seems to maintain its prognostic value for patients in whom the Ph occurs as a primary event, but not in those in whom it occurs as a secondary one., (Copyright 2010 Elsevier Inc. All rights reserved.)

The advent of atypical antipsychotics presented psychiatrists with an effective way of treating psychosis without the many side effects associated with conventional agents. Given the superiority of atypical antipsychotics, we examined demographic information and treatment histories of patients currently treated with conventional antipsychotics, especially in regard to treatment with atypical agents. Medication histories and demographic information for 276 patients admitted to an urban hospital were obtained by patient/family interviews and review of medical records. Chi-square and logistic regression tests were used to analyze data for possible predictive factors of which patients within the sample were still receiving conventional antipsychotics for treatment. Seventy-eight (28%) patients were currently being treated with conventional antipsychotics. More than half of them had never received a trial of an atypical agent. African-Americans, who are more likely to suffer adverse effects from conventional antipsychotics, and substance abusers were overrepresented in this group. It is unclear to what extent ethnic or cultural bias played a role in determining medication choice. Because conventional antipsychotics are associated with more side effects and greater medication nonadherence, these patients should be evaluated for appropriateness of a trial with an atypical agent even if they are currently stable with a conventional antipsychotic.

Background: Recent studies suggest a role for the atypical antipsychotic olanzapine in the acute treatment of psychotic mood disorders, but long-term data are unavailable. The purpose of this naturalistic study was to determine the long-term effectiveness and tolerability of olanzapine as add-on therapy in psychotic mood disorders., Method: Hospital records were reviewed for 125 inpatients at the state psychiatric hospital in Buffalo, N.Y., who received at least 6 weeks of add-on olanzapine treatment for psychotic mood disorders (schizoaffective disorders [bipolar and depressive type], bipolar disorders [I, II, and NOS], and major depressive disorder). A group of schizophrenic patients served as a control group (N = 50). Baseline measures, including age, gender, number of hospitalizations in the 2 years prior to olanzapine treatment, concomitant medications, the Clinical Global Impressions scale (CGI), and the Global Assessment of Functioning-Equivalent (GAF-EQ) and Kennedy Axis V psychological impairment, violence, social skills, and activities of daily living subscale scores, were obtained. Follow-up information was obtained from the patients at least 6 months after initiation of olanzapine or by chart review and discussion with the treating psychiatrist. Patients with a diagnosis of psychotic mood disorders were compared with patients with the non-affective psychotic disorder (schizophrenia) on a variety of outcome measures., Results: Follow-up information was available on 102 patients (82%). Mean follow-up was 15 months; 50 (49%) of the 102 patients remained on olanzapine treatment at follow-up (32 psychotic mood disorder, 18 schizophrenic). The primary reason for discontinuation in both groups was lack of response. Both the psychotic mood disorder and schizophrenic groups had comparable outcomes on the CGI and GAF-EQ. Improvement on the Kennedy Axis V psychological impairment and social skills subscales was seen only in the psychotic mood disorders group (p < .01); both groups showed significant (p < .02) improvement in the violence subscale. Sustained mood-stabilizing effect was evident in only 7/27 (26%) of the psychotic mood disorders patients continuing on add-on olanzapine treatment at follow-up., Conclusion: Lack of response was the primary reason for discontinuation of add-on olanzapine in both groups. Mood symptoms predicted a better response to add-on olanzapine in patients with psychotic mood disorders on selective outcome measures. However, only 26% of the patients with psychotic mood disorders sustained a clinically meaningful mood-stabilizing effect with add-on olanzapine treatment at follow-up.

The optimal sequence of a paclitaxel-radiation combination was investigated in vitro in two human colon adenocarcinoma cell lines, HT29 and LoVo. Three schedules of combined treatment were tested by clonogenic and flow cytometric assays. Paclitaxel was given 24 h prior to a single radiation shot (first schedule) or 24 h (second schedule) or 48 h (third schedule) before 3 days of concomitant radiation. Dose-response data were fit to a linear quadratic model, and mean inactivation dose and sensitizer enhanced ratio were calculated. In HT29 cells, the first and second schedule resulted in an additive effect, whereas a supraadditive interaction was observed with the third combination schedule. This effect was obtained with amounts of paclitaxel lower than IC50, which did not result in cell cycle perturbation, and with low radiation dose (2 Gy) that may be given in a clinical setting. LoVo cells were less sensitive to combined treatment than HT29 cells, switching from infraadditive (first and second schedule) to additive interaction (third schedule). Posttreatment recovery studies of third schedule showed a loss of cell survival in HT29 cells but not in LoVo cells. In contrast to LoVo cells, the third schedule in HT29 cells was able to induce perturbation of cell cycle kinetics, an effective impairment of DNA repair, and apoptotic cell death. HT29 and LoVo cells showed constitutional different characteristics: HT29 cells were more sensitive to paclitaxel exposure, less radiosensitive, and had a different cell cycle redistribution after radiation exposure than LoVo cells; moreover, HT29 cells showed a major propensity to undergo apoptosis. These results suggest that the radiosensitizing effect of paclitaxel was strictly schedule dependent, and the inhibition of DNA repair, cell cycle redistribution, and apoptosis could be the mechanisms for the induction of radiosensitization by paclitaxel.

The combination of differentiation-inducing agents with conventional antineoplastic drugs has been suggested as a potential new cancer therapeutic approach. We have assayed the cytotoxic effect of N-Methylformamide (NMF) as a differentiating agent combined with Paclitaxel, a novel antineoplastic agent, on cell survival of a human adenocarcinoma cell line HT29. The cell killing of this combination was evaluated by clonogenic assay and cell cycle perturbation was analyzed by flow cytometric methods. HT29 cells were exposed to graded doses of Paclitaxel (0.001-0.01-0.1-1-5 micrograms/ml) for 2, 4, 8, 16, 18 and 24 hours in order to determine its dose-time effect. Secondly, exponentially or non-growing HT29 cells were exposed to graded doses of Paclitaxel (0.001-5 micrograms/ml) for 18 hours at 37 degrees C, and in combination experiments the cells were pre- or posttreated with 1% NMF for 72 hours. The results demonstrated that only proliferating cells were responsive to Paclitaxel and that its cytotoxicity is strictly related to exposure time. The combination studies showed that only the Paclitaxel-->NMF sequence causes a powerful reduction in the surviving fraction of HT29 cells, whereas the reverse sequence had a protective effect on cell killing. The flow cytometry evaluation has indicated that synergism with NMF in HT29 cells was observed only at the same Paclitaxel concentrations required for mitotic arrest, suggesting that the mechanism underlying the synergic interaction was a Paclitaxel-induced alteration of cell cycle kinetics. This study stresses the importance of the administration sequence in the protocols involving NMF as a cytotoxic effect modulator as well as the role of cell kinetics in determining the effectiveness of this modulation.

Five pesticides [amitraz, cyanazine, cyhexatin, dinitro-o-cresol (DNOC), and fenarimol] were tested as pure active ingredients for in vivo induction of DNA strand breaks on rat hepatocytes after intraperitoneal (ip) treatment. Two pesticides, fenarimol and DNOC, were capable of inducing DNA damage because they significantly increased the DNA unwinding rate. On the contrary, amitraz, cyanazine, and cyhexatin were not DNA-damaging agents.

The genotoxic effects of the herbicide dicamba have been studied by measuring 1) the unwinding rate of liver DNA from intraperitoneally (i.p.) treated rats (fluorimetric assay); 2) DNA repair as unscheduled DNA synthesis (UDS) induced in cultured human peripheral blood lymphocytes (HPBL); and 3) sister chromatid exchanges (SCE) in HPBL. Results show that dicamba is capable of inducing DNA damage since it significantly increases the unwinding rate of rat liver DNA in vivo and also induces UDS in HPBL in vitro in the presence of exogenous metabolic activation (S-9 mix). Furthermore, dicamba causes a very slight increase in SCE frequency in HPBL in vitro.