BMC Pharmacology & Toxicology最新文献

Among 284 human immunodeficiency virus (HIV)-hepatitis B virus (HBV) coinfected adults starting tenofovir-based antiretroviral therapy (ART) in Zambia, median baseline CD4+ count was 202 cells/mm3 and 41.6% were hepatitis B e-antigen positive. Within 2 years of therapy, 29 (10.2%) participants experienced HBV functional cure (confirmed loss of hepatitis B surface antigen). In multivariable analysis, baseline CD4 count <350 cells/mm3, female sex, and lower baseline HBV deoxyribonucleic acid were associated with increased odds of functional cure. Immune recovery during HIV-HBV treatment with ART may drive higher rates of functional cure than during HBV monoinfection treatment. Understanding the mechanisms underlying this phenomenon could inform immunomodulatory therapies for HBV cure.

Glioblastoma (GBM) brain tumor remains among the most lethal and incurable human diseases. Oncogenic microRNA-10b (miR-10b) is strongly and universally upregulated in GBM, and its inhibition by antisense oligonucleotides (ASOs) reduces the growth of heterogeneous glioma cells; therefore, miR-10b represents a unique therapeutic target for GBM. Here we explored the effects of miR-10b gene editing on GBM. Using the clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 system, we investigated effects of miR-10b gene editing on the growth of cultured human glioma cells, tumor-initiating stem-like cells, and mouse GBM xenografts, as well as the oncogene-induced transformation of normal astrocytes. We show that GBM is strictly "addicted" to miR-10b and that miR-10b gene ablation is lethal for glioma cell cultures and established intracranial tumors. miR-10b loss-of-function mutations lead to the death of glioma, but not other cancer cell lines. We have not detected escaped proliferative clones of GBM cells edited in the miR-10b locus. Finally, neoplastic transformation of normal astrocytes was abolished by the miR-10b-editing vectors. This study demonstrates the feasibility of gene editing for brain tumors in vivo and suggests virus-mediated miR-10b gene ablation as a promising therapeutic approach that permanently eliminates the key regulator essential for tumor growth and survival.

Background: CLP is an orally administered, non-absorbed, superabsorbent polymer being developed to increase fecal excretion of sodium, potassium and water in patients with heart failure and end-stage renal disease. This study was conducted to evaluate the safety of CLP, and to explore dose-related effects on fecal weight, fecal and urine sodium and potassium excretion, and serum electrolyte concentrations.

Methods: This Phase 1, open-label, dose-escalation study included 25 healthy volunteers, who were administered CLP orally immediately prior to four daily meals for 9 days at doses of 7.5, 15.0, and 25.0 g/day (n = 5/group). An additional dose group received 15.0 g/day CLP under fasting conditions, and an untreated cohort (n = 5) served as control. Twenty-four-hour fecal and urinary output was collected daily. Samples were weighed, and sodium, potassium, and other ion content in stool and urine were measured for each treatment group. Effects on serum cation concentrations, other standard laboratory values, and adverse events were also determined.

Results: At doses below 25.0 g/day, CLP was well tolerated, with a low frequency of self-limiting gastrointestinal adverse events. CLP increased fecal weight and fecal sodium and potassium content in a dose-related manner. Concomitant dose-related decreases in urinary sodium and potassium were observed. All serum ion concentrations remained within normal limits.

Conclusions: In this study, oral CLP removed water, sodium and potassium from the body via the gastrointestinal tract in a dose related fashion. CLP could become useful for patients with fluid overload and compromised kidney function in conditions such as congestive heart failure, salt sensitive hypertension, chronic kidney disease and end stage renal disease.

Trial registration: NCT01944007.

Background: Oxaliplatin-based regimens induce a potential risk of hypersensitivity reaction (HSR), with incidence varying from 10% to 25% and lack of clearly identified risk factors. The present study aimed to assess incidence and risk factors in HSR.

Methods: All patients treated with oxaliplatin in the Medical Oncology Department of the Lyon Sud University Hospital (Hospices Civils de Lyon, France) from October 2004 to January 2011 were enrolled. Incidence and severity of HSR were analyzed retrospectively and the potential clinicopathological covariates were tested on univariate and multivariate analysis.

Results: A total of 1,221 doses of oxaliplatin were administered for 191 patients, 8.9% of whom experienced an HSR. Seventeen HSRs were observed, with 1.6% grade 3 and no grade 4 events. The first reaction appeared after a median of 3 oxaliplatin infusions. Using univariate analysis, HSR was associated with younger age (mean age, 56.2 years; p = 0.04), female gender (p = 0.01) and prior exposure to platinum salts (p = 0.02). No increased risk was associated with mean dose or with presence of atopic background. Multivariate analysis confirmed that women were at higher risk of oxaliplatin HSR than men (p < 0.05). Reintroduction of oxaliplatin was effective in 64.7% of hypersensitive patients using an appropriate premedication strategy. Patients who experienced a grade 3 HSR were not rechallenged.

Conclusion: The risk of developing oxaliplatin HSR should not be underestimated (8.9% of patients). The medical team's vigilance should be increased with women, younger patients and patients with prior exposure to platinum salts.

Background: The gut microbiota is critical for intestinal homeostasis. Recent studies have revealed the links between different types of dysbiosis and diseases inside and outside the intestine. Environmental exposure to pollutants (such as heavy metals) can also impair various physiological functions for good health. Here, we studied the impact of up to 8 weeks of oral lead and cadmium ingestion on the composition of the murine intestinal microbiome.

Results: Pyrosequencing of 16S RNA sequences revealed minor but specific changes in bacterial commensal communities (at both family and genus levels) following oral exposure to the heavy metals, with notably low numbers of Lachnospiraceae and high numbers levels of Lactobacillaceae and Erysipelotrichaceacae (mainly due to changes in Turicibacter spp), relative to control animals.

Conclusions: Non-absorbed heavy metals have a direct impact on the gut microbiota. In turn, this may impact the alimentary tract and overall gut homeostasis. Our results may enable more accurate assessment of the risk of intestinal disease associated with heavy metal ingestion.

Background: Carbon monoxide (CO) intoxication is a leading cause of severe neuropsychological impairments. Peripheral nerve injury has rarely been reported. It consists usually in a demyelinating polyneuropathy or mononeuropathy affecting mainly the lower limbs. Isolated involvement of both upper extremities has been described in only 4 patients related to root damage. We report the first case of bilateral brachial plexus injury following CO poisoning and review all previous CO-induced neuropathy described in literature.

Case presentation: After being unconscious for three hours, a 42 years old man experienced bilateral brachial weakness associated with edema of the face and the upper limbs. Neurological examination showed a brachial diplegia, distal vibratory, thermic and algic hypoesthesia, deep tendon areflexia in upper limbs. There was no sensory or motor deficit in lower extremities. No cognitive disturbances were detected. Creatine kinase was elevated. Electroneuromyogram patterns were compatible with the diagnosis of bilateral C5 D1 brachial axonal plexus injury predominant on the left side. Clinical course after hyperbaric oxygen therapy was marked by a complete recovery of neurological disorders.

Conclusion: Peripheral neuropathy is an unusual complication of CO intoxication. Bilateral brachial plexus impairment is exceptional. Various mechanisms have been implicated including nerve compression secondary to rhabdomyolysis, nerve ischemia due to hypoxia and direct nerve toxicity of carbon monoxide. Prognosis is commonly excellent without any sequelae.

Background: Indoxyl sulfate (IS), an organic anion uremic toxin, promotes the progression of renal dysfunction. Some studies have suggested that IS inhibits osteoclast differentiation and suppresses parathyroid hormone (PTH)-stimulated intracellular cAMP production, decreases PTH receptor expression, and induces oxidative stress in primary mouse calvaria osteoblast cell culture. However, the direct effects of IS on osteoblast apoptosis have not been fully evaluated. Hence, we investigated whether IS acts as a bone toxin by studying whether IS induces apoptosis and inhibits differentiation in the cultured osteoblast cell line MC3T3-E1.

Methods: We assessed the direct effect of IS on osteoblast differentiation and apoptosis in the MC3T3-E1 cell line. We examined caspase-3/7 activity, apoptosis-related proteins, free radical production, alkaline phosphatase activity, and mRNA expression of type 1 collagen and osteonectin. Furthermore, we investigated the uptake of IS via organic anion transport (OAT).

Results: We found that IS increased caspase activity and induced apoptosis. Production of free radicals increased depending on the concentration of IS. Furthermore, IS inhibited the expression of mRNA type 1 collagen and osteonectin and alkaline phosphatase activity. The expression of OAT, which is known to mediate the cellular uptake of IS, was detected in in the MC3T3-E1 cell line. The inhibition of OAT improved cell viability and suppressed the production of reactive oxygen species. These results suggest that IS is transported in MC3T3-E1 cells via OAT, which causes oxidative stress to inhibit osteoblast differentiation.

Conclusions: IS acts as a bone toxin by inhibiting osteoblast differentiation and inducing apoptosis.

Introduction: Patients with febrile neutropenia (FN) exhibit changes in extracellular fluid that may alter the plasma concentrations of beta-lactams and result in therapeutic failure or toxicity. We evaluated the pharmacokinetics of piperacillin/tazobactam in patients with hematological malignancies and FN after receiving chemotherapy at a primary public cancer center.

Methods: This was an open, nonrandomized, observational, descriptive, and prospective study. Samples from 15 patients with hematological malignancies and FN were evaluated after the administration of chemotherapy. Five blood samples were taken from each patient when the antibiotic level was at steady-state 10, 60, 120, 180, and 350 min after each dose. Antibiotic concentrations were measured using gel diffusion with Bacillus subtilis. All study participants provided written informed consent.

Results: We investigated the pharmacokinetics of piperacillin in 14 patients between the ages of 18 years and 59 years and with a mean absolute neutrophil count of 208 cells per mm³ (standard deviation (SD) ± 603.2). The following pharmacokinetic measurements were obtained: maximum concentration, 94.1-1133 mg/L; minimum concentration, 0.47-37.65 mg/L; volume of distribution, 0.08-0.65 L/kg (mean, 0.34 L/kg); drug clearance (CL), 4.42-27.25 L/h (mean, 9.93 L/h); half-life (t(1/2)), 0.55-2.65 h (mean, 1.38 h); and area under the curve, 115.12-827.16 mg · h/L.

Conclusion: Patients with FN after receiving chemotherapy exhibited significant variations in the pharmacokinetic parameters of piperacillin compared with healthy individuals; specifically, FN patients demonstrated an increase in t1(/2) and decreased CL.

Background: Chemotherapy-induced hair loss (alopecia) (CIA) is one of the most feared side effects of chemotherapy among cancer patients. There is currently no pharmacological approach to minimize CIA, although one strategy that has been proposed involves protecting normal cells from chemotherapy by transiently inducing cell cycle arrest. Proof-of-concept for this approach, known as cyclotherapy, has been demonstrated in cell culture settings.

Methods: The eukaryotic initiation factor (eIF) 4E is a cap binding protein that stimulates ribosome recruitment to mRNA templates during the initiation phase of translation. Suppression of eIF4E is known to induce cell cycle arrest. Using a novel inducible and reversible transgenic mouse model that enables RNAi-mediated suppression of eIF4E in vivo, we assessed the consequences of temporal eIF4E suppression on CIA.

Results: Our results demonstrate that transient inhibition of eIF4E protects against cyclophosphamide-induced alopecia at the organismal level. At the cellular level, this protection is associated with an accumulation of cells in G1, reduced apoptotic indices, and was phenocopied using small molecule inhibitors targeting the process of translation initiation.

Conclusions: Our data provide a rationale for exploring suppression of translation initiation as an approach to prevent or minimize cyclophosphamide-induced alopecia.