A novel construct of an electrochemical acetylcholinesterase biosensor for the investigation of malathion sensitivity to three different insect species using a NiCr2O4/g-C3N4 composite integrated pencil graphite electrode

Herein, an electrochemical biosensor has been prepared to assess the sensitivity of an organophosphate insecticide, malathion, to acetylcholinesterase (AChE) enzyme of three insects including Apis mellifera (honeybee), Tribolium castaneum (red flour beetle), and Zootermopsis nevadensis (dampwood termite). A composite of nickel chromite (NiCr₂O₄) and graphitic carbon nitride (g-C₃N₄) was prepared and characterized for its morphological, chemical and electrical properties. The NiCr₂O₄/g-C₃N₄ composite integrated pencil graphite electrodes were used to covalently immobilize insect AChE enzymes and amperometric response of bioelectrodes was determined through cyclic voltammetry. The prepared bioelectrodes exhibited high enzyme immobilization efficiency and electro-catalytic performance. The integrated bioelectrodes could efficiently detect malathion induced inhibition of insects'' AChEs. The linear ranges for malathion were found to be 0.1–1.6 μM, 1–40 nM and 2–100 nM, and LODs were 2 nM, 0.86 nM and 2.3 nM for A. mellifera, T. castaneum, and Z. nevadensis, respectively. Additionally, the biosensing platform developed using A. mellifera AChE was found highly sensitive and effective for malathion recoveries from spiked wheat flour samples with high recovery rates. Moreover, the proposed method was adequately reproducible and selective. The results revealed that A. mellifera AChE is less sensitive to inhibition by malathion as compared to T. castaneum, and Z. nevadensis AChE. The experimental results were validated through computational docking of malathion with insect AChEs and the results were in correspondence to experimental outcomes. The proposed method can be a plausible alternate to conventional analytical methods to assess the pesticide sensitivity and toxicity of various compounds against insect enzymes.

An innovative electrochemical assay has been established to determine pesticide sensitivity against acetylcholinesterase and possible toxicity against insects. The analytical efficiency of three common insect AChEs was determined through this method.     

造血干细胞移植与临床感染的防治

学术背景:造血干细胞移植技术在临床上已得到广泛应用,移植后感染是关系到移植成败的重要因素。目的:探讨造血干细胞移植后各阶段的感染的特点、预防及治疗,以进一步减低造血干细胞移植后感染的发生率及死亡率。检索策略:由作者应用计算机检Medline 1994-01/2007-05关于造血干细胞移植及移植后感染的文章,检索词为"hematopoietic stem cell transplantation,infection",限定语言种类为"English";同时检索中国期刊全文数据库1994-01/2007-05相关文章,检索词"造血干细胞移植,感染,防治",限定语言种类为中文。纳入标准:随机对照研究;实验或临床研究包含平行对照组。排除标准:重复性研究文献评价:初检得到212篇文献,初审后选取与造血干细胞移植后感染有关的文章126篇,删除明显无关及相关性不强的文章,进一步查找全文,29个实验符合标准,予以纳入。29个研究包括324例患者和140个实验动物,分别阐述了造血干细胞移植后感染的原因、途径、特点、种类及各种感染的预防及治疗措施。资料综合:造血干细胞移植后感染发病隐匿,由于患者免疫力低下,感染不易控制,在不同阶段致病菌的种类有所不同,细菌感染普遍,在移植后各个时期均可出现,真菌感染和病毒感染致死性强,故预防和治疗感染至关重要,其治疗分为预防治疗、抢先治疗、经验性治疗和针对治疗。结论:造血干细胞移植后感染的治疗已成为影响移植疗效的一个重要原因,及早的诊断及正确的治疗将成为移植后感染治疗成功的关键。     

Postnatal histomorphogenesis of the mandible in the house mouse

The mandible of the house mouse, Mus musculus, is a model structure for the study of the development and evolution of complex morphological systems. This research describes the histomorphogenesis of the house mouse mandible and analyses its biological significance from the first to the eighth postnatal weeks. Histological data allowed us to test a hypothesis concerning modularity in this structure. We measured the bone growth rates by fluorescent labelling and identified the bone tissue types through microscopic analysis of histological cross-sections of the mandible during its postnatal development. The results provide evidence for a modular structure of the mouse mandible, as the alveolar region and the ascending ramus show histological differences throughout ontogeny. The alveolar region increases in length during the first two postnatal weeks by bone growth in the posterior region, while horizontally positioned incisors preclude bone growth in the anterior region. In the fourth postnatal week, growth dynamics shows a critical change. The alveolar region drifts laterally and the ramus becomes more vertical due to the medial growth direction of the coronoid region and the lateral growth of the ventral region of the ramus. Diet changes after weaning are probably involved in these morphological changes. In this way, the development of the masticatory muscles that insert on the ascending ramus may be particularly related to this shape modeling of the house mouse mandible.     

Predictors of failure after fecal microbiota transplantation for recurrent Clostridioides difficile infection: a systematic review and meta-analysis

Fecal microbiota transplantation (FMT) is a highly effective therapy for recurrent Clostridioides difficile infection (CDI), with ~15% 1-year recurrence rate. Small studies have identified variable risk factors associated with FMT failure. We, therefore, performed a systematic review and meta-analysis to evaluate the predictors of FMT failure. A systematic search of Medline, Embase, and Web of Science was performed from January 2013 up to June 2020. Meta-analyses were performed using random-effects models and pooled adjusted odds ratios for risk factors reported in ≥2 studies were calculated. Overall, 2671 patients with recurrent CDI who underwent FMT in 12 studies were included. FMT failure occurred in 454 patients (16.9%) with median follow-up of 3 months (range 2–7.7 months). A total of 9 risk factors were identified in ≥2 studies. Meta-analysis showed that use of non- CDI antibiotics, presence of inflammatory bowel disease, poor quality of bowel preparation, CDI-related hospitalization before FMT, inpatient FMT, and severe CDI were associated with statistically significant increased risk of failure after FMT. Increasing age, female gender, and immunocompromised status were not associated with increased risk for FMT failure. Several risk factors (both modifiable and non-modifiable) are associated with FMT failure. Lower use of antibiotics in the post-FMT period and good bowel preparation at the time of FMT are associated with lower risk of failure after FMT. Additionally, patients with non-modifiable risk factors should be counseled to be particularly alert about recurrent symptoms after FMT.

     

Attention and memory in aged rats: Impact of lifelong environmental enrichment

Aged rodents exhibit memory and attention dysfunctions. Environmental enrichment (EE) attenuates memory impairments. Whether it may reduce attention deficits is not known. At the age of 1 month, Long-Evans female rats were placed in standard or EE conditions and tested after 3 (young), 12 (middle-aged) or 24 (aged) months of differential housing. Spatial reference memory was assessed in a water-maze task. Attention performance was evaluated in the five-choice serial reaction time (5-CSRT) task. EE improved spatial memory at all ages, but did not ameliorate 5-CSRT performance in young and middle-aged rats; it prevented, however, the degradation of attention performances detected in aged rats. The number of ChAT (+30 to +64%)- and p75^NTR-positive (+35 to +44%) neurons was higher in the basal forebrain of aged enriched vs. standard rats, suggesting their EE-mediated protection. The weaker deficit of attention found in aged EE rats might be linked to a better survival in the very long term of neurons in the basalo-cortical system.     

Inferior detection of information from collaborative versus individual crimes based on a P300 Concealed Information Test

The present study used a P300‐based Concealed Information Test (CIT) to detect individual and collaborative crimes and to explore whether or not the P300 index is effective in identifying collaborative crime members. Participants were divided into two groups to either steal a ring alone (individual group) or collaboratively with another companion participant (collaborative group) before taking the Complex Trial Protocol test that is regarded as an accurate version of the P300‐based CIT. The ERP results revealed that both groups showed significantly larger P300s to probe (the ring) than to all irrelevant stimuli (other jewelery), but the P300 amplitude difference of probe stimulus versus irrelevant stimuli in the collaborative group was significantly less than that in the individual group. For the individual diagnosis, using P300 index, the detection rate was significantly inferior for collaborative crime than individual crime, probably related to weakness of collaborative encoding. The ROC curve comparisons showed the individual guilty was effectively discriminated from the simulated‐innocent (AUC = .84) and from the collaborative guilty (AUC = .83), but the collaborative guilty was not discriminable from the simulated‐innocent (AUC = .66). These findings suggest that collaborative encoding of crime‐related information impacts the efficiency of the P300 index, and that the P300‐based CIT is not applicable when used to identify collaborative crime perpetrators.     

Exercise capacity as an independent risk factor for adverse cardiovascular outcomes among nondiabetic and diabetic patients

Introduction

To investigate if decreased exercise capacity is an independent risk factor for major adverse cardiovascular events (MACE) in diabetics and nondiabetics.

Material and methods

The association of decreased exercise capacity (EC) during a treadmill exercise sestamibi stress test with MACE was investigated in 490 nondiabetics and 404 diabetics. Mean follow-up was 53 months.

Results

Nondiabetics with a predicted EC < 85% had a higher prevalence of myocardial ischemia (34% vs. 19%, p = 0.0002), 2- or 3-vessel obstructive coronary artery disease (CAD) (31% vs. 13%, p = 0.016), myocardial infarction (MI) (17% vs. 7%, p = 0.0005), stroke (8% vs. 2%, p = 0.002), death (11% vs. 3%, p = 0.0002), and MI or stroke or death at follow-up (32% vs. 11%, p < 0.001) compared to nondiabetics with a predicted EC ≥ 85%. Diabetics with a predicted EC < 85% had a higher prevalence of myocardial ischemia (48% vs. 32%, p = 0.0009), 2- or 3-vessel obstructive CAD (54% vs. 28%, p = 0.001), MI (32% vs. 14%, p < 0.001), stroke (22% vs. 6%, p < 0.001), death (17% vs. 9%, p = 0.031), and MI or stroke or death at follow-up (65% vs. 27%, p < 0.001). Stepwise Cox regression analysis showed decreased EC was an independent and significant risk factor for MACE among nondiabetics (hazard ratio 3.3, p < 0.0001) and diabetics (hazard ratio 2.7, p < 0.0001).

Conclusions

Diabetics and nondiabetics with decreased EC were at increased risk for MACE with nondiabetics and decreased EC at similar risk as diabetics with normal EC.     

Intracranial Dural Sinus Thrombosis: Novel Use of a Mechanical Thrombectomy Catheter and Review of Management Strategies

Management of intracranial dural sinus thrombosis with involvement of multiple sinuses is complex, often involving not only the primary problem (thrombosis) but acute adverse events consequent to the disease. We highlight the novel use of an endovascular device (typically for suction thrombectomy in the peripheral vascular system) used in our patient with a life-threatening multi-sinus thrombosis. As there is no standard treatment yet for cranial sinus thrombosis, our review of the literature highlights some effective management strategies. A 35-year-old woman developed associated complications of cranial sinus thrombosis that included intracranial hypertension caused by an expanding intracranial hematoma, pulmonary embolism treated by placement of filters in superior and inferior vena cava to eliminate intra- and extracranial sources of emboli, and procedure-related retroperitoneal hematoma that necessitated peripheral vascular intervention. After failure of several common devices during mechanical thrombolysis, a thrombectomy catheter (typically for peripheral vascular intervention to aide in the clot removal) was used. Our case highlights the fine balance of anticoagulation and thrombolysis and the proactive, aggressive approach used by our multispecialty team to manage concurrent factors.     

Very late recurrence of childhood acute lymphoblastic leukemia treated with chemoimmunotherapy: a report of three cases occurring 19, 11, and 9 years after discontinuation of chemotherapy

Current therapeutic modalities for childhood acute lymphoblastic leukemia (ALL) are associated with a high cure rate, and recurrences more than 4 years after therapy cessation are very unusual. We report three cases of exceptionally late recurrences of childhood ALL after cessation of chemotherapy (CT) given for respective periods of 8, 7, and 24 months. CT was followed by maintenance immunotherapy (IMT) with Bacillus Calmette-Guérin (BCG) and allogeneic leukemic lymphoblasts pretreated with formaldehyde or irradiated in vitro. Leukemic recurrences were observed 19, 11, and 9 years after cessation of CT and appeared morphologically similar to the original blasts. A second complete remission was easily achieved in all three patients, but two went on to repeated relapse (one has died following the fourth recurrence). We speculate that some residual leukemic cells, remaining after the inadequate, short-term CT, were responsible for these unusual evolutions, and we question a possible delaying role of IMT in prolonging remission. Other possible etiologies are discussed.     

Recurrent chest pain as the presenting manifestation of spinal meningioma

We report the case of a 9-year-old boy with a spinal cord meningioma whose only manifestations were recurrent episodes of chest pain lasting for 2 years. This case shows that spinal cord meningioma should be considered among the possible causative factors of chronic chest pain in childhood. Chest pain, meningioma, spinal tumors