Interaction of acetamiprid, Varroa destructor, and Nosema ceranae in honey bees

Health of honey bees is threatened by a variety of stressors, including pesticides and parasites. Here, we investigated effects of acetamiprid, Varroa destructor, and Nosema ceranae, which act either alone or in combination. Our results suggested that interaction between the three factors was additive, with survival risk increasing as the number of stressors increased. Although exposure to 150 μg/L acetamiprid alone did not negatively impact honey bee survival, it caused severe damage to midgut tissue. Among the three stressors, V. destructor posed the greatest threat to honey bee survival, and N. ceranae exacerbated intestinal damage and increased thickness of the midgut wall. Transcriptomic analysis indicated that different combinations of stressors elicited specific gene expression responses in honey bees, and genes involved in energy metabolism, immunity, and detoxification were altered in response to multiple stressor combinations. Additionally, genes associated with Toll and Imd signalling, tyrosine metabolism, and phototransduction pathway were significantly suppressed in response to different combinations of multiple stressors. This study enhances our understanding of the adaptation mechanisms to multiple stressors and aids in development of suitable protective measures for honey bees. ENVIRONMENTAL IMPLICATION: We believe our study is environmentally relevant for the following reasons: This study investigates combined effects of pesticide, Varroa destructor, and Nosema ceranae. These stressors are known to pose a threat to long-term survival of honey bees (Apis mellifera) and stability of the ecosystems. The research provides valuable insights into the adaptive mechanisms of honey bees in response to multiple stressors and developing effective conservation strategies. Further research can identify traits that promote honey bee survival in the face of future challenges from multiple stressors to maintain the overall stability of environment.

Interactive effects of dinotefuran and Nosema ceranae on the survival status and gut microbial community of honey bees

Growing evidences have shown that the decline in honey bee populations is mainly caused by the combination of multiple stressors. However, the impacts of parasitic Nosema ceranae to host fitness during long-term pesticide exposure-induced stress is largely unknown. In this study, the effects of chronic exposure to a sublethal dose of dinotefuran, in the presence or absence of N. ceranae, was examined in terms of survival, food consumption, detoxification enzyme activities and gut microbial community. The interaction between dinotefuran and Nosema ceranae on the survival of honey bee was synergistic. Co-exposure to dinotefuran and N. ceranae led to less food consumption and greater changes of enzyme activities involved in defenses against oxidative stress. Particularly, N. ceranae and dinotefuran-N. ceranae co-exposure significantly impacted the gut microbiota structure and richness in adult honey bees, while dinotefuran alone did not show significant alternation of core gut microbiota compared to the control group. We herein demonstrated that chronical exposure to dinotefuran decreases honey bee's survival but is not steadily associated with the gut microbiota dysbiosis; by contrast, N. ceranae parasitism plays a dominant role in the combination in influencing the gut microbial community of the host honey bee. Our findings provide a comprehensive understanding of combinatorial effects between biotic and abiotic stressors on one of the most important pollinators, honey bees.

Early-Life Sublethal Thiacloprid Exposure to Honey Bee Larvae: Enduring Effects on Adult Bee Cognitive Abilities

Honey bees have significant ecological and economic value as important pollinators, but they are continuously exposed to various environmental stressors, including insecticides, which can impair their health and cause colony decline. (1) Background: Cognitive abilities are vital for the functional maintenance of honey bees; however, it remains unknown if chronic, low-dose exposure to thiacloprid during the larval stage impairs the cognitive abilities of emerged adult honey bees. (2) Methods: To explore this question, honey bee larvae were fed 0, 0.5, and 1.0 mg/L thiacloprid during their developmental phase. Then, the cognitive (i.e., olfactory learning and memory) abilities of adult honey bees were quantified to assess the delayed impacts of early-stage thiacloprid exposure on adult honey bee cognition. Neural apoptosis and transcriptomic level were also evaluated to explore the neurological mechanisms underlying these effects. (3) Results: Our results revealed that chronic larval exposure to sublethal thiacloprid impaired the learning and memory abilities of adult honey bees by inducing neuronal apoptosis and transcriptomic alterations. (4) Conclusions: We highlighted a previously unknown impairment caused by thiacloprid in honey bees.

Interaction of chlorothalonil and Varroa destructor on immature honey bees rearing in vitro

Under realistic environmental conditions, bees are often exposed to multiple stressors, especially Varroa destructor and pesticides. In this study, the effects of exposure to NOAEC of chlorothalonil during the larval stage, in the presence or absence of V. destructor, was examined in terms of survival, morphological and transcriptional changes. The interaction between chlorothalonil and V. destructor on the survival of honey bee was additive. V. destructor are the dominant factor in the interaction for survival and transcriptome alternation. The downregulation of the genes related to tissue growth and caste differentiation may directly link to the mortality of honey bees. Either chlorothalonil or V. destructor induces the irregular morphology of trophocytes and oenocytes in the fat body. In addition to irregular shapes, oenocytes in V. destructor alone and double-stressor treatment group showed altered nuclei and vacuoles in the cytoplasm. The interaction of V. destructor and chlorothalonil at the larval stage have potential adverse effects on the subsequent adult bees, with up-regulation of genes involved in lipid metabolism and detoxification/defense in fat body tissue. Our findings provide a comprehensive understanding of combinatorial effects between biotic and abiotic stressors on one of the most important pollinators, honey bees.

Greater wax moth control in apiaries can be improved by combining Bacillus thuringiensis and entrapments

The greater wax moth (GWM), Galleria mellonella (Lepidoptera: Pyralidae), is a major bee pest that causes significant damage to beehives and results in economic losses. Bacillus thuringiensis (Bt) appears as a potential sustainable solution to control this pest. Here, we develop a novel Bt strain (designated BiotGm) that exhibits insecticidal activity against GWM larvae with a LC50 value lower than 2 μg/g, and low toxicity levels to honey bee with a LC50 = 20598.78 μg/mL for larvae and no observed adverse effect concentration = 100 μg/mL for adults. We design an entrapment method consisting of a lure for GWM larvae, BiotGm, and a trapping device that prevents bees from contacting the lure. We find that this method reduces the population of GWM larvae in both laboratory and field trials. Overall, these results provide a promising direction for the application of Bt-based biological control of GWM in beehives, although further optimization remain necessary.

SARS-CoV-2 and male infertility: from short- to long-term impacts

PURPOSE

The coronavirus 2019 (COVID-19) pandemic-caused by a new type of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-has posed severe impacts on public health worldwide and has resulted in a total of > 6 million deaths. Notably, male patients developed more complications and had mortality rates ~ 77% higher than those of female patients. The extensive expression of the SARS-CoV-2 receptor and related proteins in the male reproductive tract and the association of serum testosterone levels with viral entry and infection have brought attention to COVID-19's effects on male fertility.

METHODS

The peer-reviewed articles and reviews were obtained by searching for the keywords SARS-CoV-2, COVID-19, endocrine, spermatogenesis, epididymis, prostate, and vaccine in the databases of PubMed, Web of Science and Google Scholar from 2020-2022.

RESULTS

This review summarizes the effects of COVID-19 on the male reproductive system and investigates the impact of various types of SARS-CoV-2 vaccines on male reproductive health. We also present the underlying mechanisms by which SARS-CoV-2 affects male reproduction and discuss the potentially harmful effects of asymptomatic infections, as well as the long-term impact of COVID-19 on male reproductive health.

CONCLUSION

COVID-19 disrupted the HPG axis, which had negative impacts on spermatogenesis and the epididymis, albeit further investigations need to be performed. The development of vaccines against various SARS-CoV-2 variations is important to lower infection rates and long-term COVID risks.

[Differential diagnosis and surgical management in chondrosarcoma of the jugular foramen]

Objective: To explore the diagnosis, surgical management and outcome of jugular foramen chondrosarcoma (CSA). Methods: Fifteen patients with jugular foramen CSA hospitalized in the Department of Otorhinolaryngology Head and Neck Surgery of Chinese PLA General Hospital from December 2002 to February 2020 were retrospectively collected,of whom 2 were male and 13 were female, aging from 22 to 61 years old. The clinical symptoms and signs, imaging features, differential diagnosis, surgical approaches, function of facial nerve and cranial nerves IX to XII, and surgical outcomes were analyzed. Results: Patients with jugular foramen CSA mainly presented with facial paralysis, hearing loss, hoarseness, cough, tinnitus and local mass. Computed tomography (CT) and magnetic resonance (MR) could provide important information for diagnosis. CT showed irregular destruction on bone margin of the jugular foramen. MR demonstrated iso or hypointense on T1WI, hyperintense on T2WI and heterogeneous contrast-enhancement. Surgical approaches were chosen upon the sizes and scopes of the tumors. Inferior temporal fossa A approach was adopted in 12 cases, inferior temporal fossa B approach in 2 cases and mastoid combined parotid approach in 1 case. Five patients with facial nerve involved received great auricular nerve graft. The House Brackmann (H-B) grading scale was used to evaluate the facial nerve function. Preoperative facial nerve function ranked grade Ⅴ in 4 cases and grade Ⅵ in 1 case. Postoperative facial nerve function improved to grade Ⅲ in 2 cases and grade Ⅵ in 3 cases. Five patients presented with cranial nerves Ⅸ and Ⅹ palsies. Hoarseness and cough of 2 cases improved after operation, while the other 3 cases did not. All the patients were diagnosed CSA by histopathology and immunohistochemistry, with immunohistochemical staining showing vimentin and S-100 positive, but cytokeratin negative in tumor cells. All patients survived during 28 to 234 months' follow-up. Two patients suffered from tumor recurrence 7 years after surgery and received revision surgery. No complications such as cerebrospinal fluid leakage and intracranial infection occurred after operation. Conclusions: Jugular foramen CSA lacks characteristic symptoms or signs. Imaging is helpful to differential diagnosis. Surgery is the primary treatment of jugular foramen CSA. Patients with facial paralysis should receive surgery in time as to restore the facial nerve. Long-term follow-up is necessary after surgery in case of recurrence.

Thiacloprid impairs honeybee worker learning and memory with inducing neuronal apoptosis and downregulating memory-related genes

Neonicotinoids are among the most widely used insecticides in the world and are recognized as a potential cause of pollinator decline. Previous studies have demonstrated that the neonicotinoid thiacloprid has adverse effects on foraging and memory behaviors. However, there is no direct evidence linking thiacloprid-induced neuronal cell damage in the brains of honeybees to learning and memory dysfunction. Adult honeybee (Apis mellifera L.) workers were chronically exposed to sub-lethal concentrations of thiacloprid. We discovered that thiacloprid negatively affected their survival, food consumption, and body weight. In addition, sucrose sensitivity and memory performance were impaired. We evaluated the apoptosis of honeybee brain cells using TUNEL (Terminal deoxynucleotidyl transferase-mediated digoxigenin-dUTP-biotin nick-end labeling) and Caspase-3 assays, which revealed that thiacloprid increases the dose-dependent apoptosis of neurons in the mushroom bodies (MB) and antennal lobes (AL). We also determined the abnormal transcripts of multiple genes, including vitellogenin (Vg), immune system genes (apidaecin and catalase), and memory-associated genes (pka, creb, Nmdar1, Dop2, Oa1, Oa-2R, and Oa-3R). These results indicate that exposure to sublethal concentrations of thiacloprid cause abnormal expression of memory-related genes and apoptosis of brain cells in the AL and MB, which may contribute to the memory disorder induced by thiacloprid exposure.

[Phenotype-genotype analysis of the autosomal recessive hereditary hearing loss caused by OTOA variations]

Objective: To analyze the phenotypic-genotypic characteristics of hereditary deafness caused by OTOA gene variations. Methods: Family histories, clinical phenotypes and gene variations of six pedigrees were analyzed, which were diagnosed with hearing loss caused by OTOA gene variations at the PLA General Hospital from September 2015 to January 2022. The sequence variations were verified by Sanger sequencing and the copy number variations were validated by multiplex ligation-dependent probe amplification (MLPA) in the family members. Results: The hearing loss phenotype caused by OTOA variations ranged from mild to moderate in the low frequencies, and from moderate to severe in the high frequencies in the probands, which came from six sporadic pedigrees, among which a proband was diagnosed as congenital deafness and five were diagnosed as postlingual deafness. One proband carried homozygous variations and five probands carried compound heterozygous variations in OTOA gene. Nine pathogenic variations (six copy number variations, two deletion variations and one missense variation) and two variations with uncertain significance in OTOA were identified in total, including six copy number variations and five single nucleotide variants, and three of the five single nucleotide variants were firstly reported [c.1265G>T(p.Gly422Val),c.1534delG(p.Ala513Leufs*11) and c.3292C>T(p.Gln1098fs*)]. Conclusions: OTOA gene variations can lead to autosomal recessive nonsyndromic hearing loss. In this study, the hearing loss caused by OTOA defects mostly presents as bilateral, symmetrical, and postlingual, and that of a few presents as congenital. The pathogenic variations of OTOA gene are mainly copy number variations followed by deletion variations and missense variations.

Pesticide exposure and forage shortage in rice cropping system prevents honey bee colony establishment

As one of the key stable crops to feed half of the world's population, how rice cropping system affects honey bee health regarding pesticide exposure and forage availability is under investigated. We predicted honey bees were stressed by high pesticide exposure and forage dearth in monoculture rice systems. Providing access to natural habitats is a typical approach to mitigate the negative impact of intensive agriculture on honey bees. We aimed to determine if bee colonies located in landscapes with more cover of forest habitat would collect more forage and be exposed to less pesticides. We selected beekeeping locations in rice dominated landscapes (as control), mosaic landscapes of rice and medium woodland (MW) cover, and landscapes of high woodland (HW) cover, respectively, in July when rice starts bloom and pesticides are commonly used. Colonies were inspected at a biweekly frequency from July to October with population growth and forage (nectar and pollen) availability estimated. Pollen and bees were collected in middle August for pesticide exposure analysis. We did not observe enhancement in forage availability and reduction in pesticide exposure in landscapes with increased forest habitat (i.e., MW or HW cover), and all colonies failed in the end. Other natural habitats that can supplement flower shortage periods in forest can be considered for supporting bee health. Our results suggest that forest should be carefully assessed for being incorporated into beekeeping management or pollinator conservation when forest phenology can be a factor to affect its impact as a natural habitat.

[Prevalence and related factors of visual disability, hearing disability and comorbidity of visual and hearing disability among the elderly in China]

Objective: To estimate the prevalence of visual disability, hearing disability and comorbidity of visual and hearing disability among the elderly in China, and explore the related factors of comorbidity of visual and hearing disability in the elderly. Methods: This was a cross-sectional study. Based on the Second China National Sample Survey on Disability in 2006, the data of the elderly with visual and hearing disability were extracted and combined for descriptive analysis. Meanwhile, multivariate logistic regression model was used to analyze the related factors of comorbidity of visual and hearing disability among the elderly. Results: A total of 250 752 cases were in the final analysis (119 120 males and 131 632 females), and there were 164 003, 74 156 and 12 593 cases with the age of 65-<75, 75-<85 and ≥ 85 years, respectively. The prevalence of visual disability and hearing disability of the elderly in China was 8.10% (95%CI: 8.00%-8.21%), 13.41% (95%CI: 13.29%-13.54%), respectively, while the prevalence of comorbidity of visual and hearing disability was 1.97% (95%CI: 1.92%-2.02%). The severity of disability of the elderly with comorbidity of visual and hearing disability was higher, and the percentage of mild disabilities (18.31%, 966/5 277) was lower than those with visual (53.06%, 11 208/21 123) or hearing disabilities (32.96%, 11 536/34 995). Moreover, 19.40% (1 024/5 277) of visual or hearing disability occurred in the same year. Multivariate logistic regression analysis showed that education level below primary school (OR=0.65, 95%CI: 0.61-0.70, P<0.001), having a spouse (OR=0.68, 95%CI: 0.64-0.72, P<0.001), living in an urban area (OR=0.77, 95%CI: 0.71-0.82, P<0.001) and having a per capita household income higher than the national average (OR=0.73, 95%CI: 0.68-0.78, P<0.001) were protective factors for comorbidity of visual and hearing disability among the elderly. Conclusions: Visual disability is correlated with hearing disability in the elderly. Attention should be paid to the prevention and control of associated disabilities such as visual and hearing co-disabilities in the elderly population, with emphasis on strengthening publicity and education on prevention and control of visual and hearing disabilities for the elderly who are economically disadvantaged, have no spouse and live in remote areas.

Exposure of chlorothalonil and acetamiprid reduce the survival and cause multiple internal disturbances in Apis mellifera larvae reared in vitro

Background: Chlorothalonil and acetamiprid are chemical pesticides commonly used in agricultural production and have been shown to have negative effects on bee's fitness. Despite many studies have revealed that honey bee (Apis mellifera L.) larvae are posting a high risk on exposure to pesticides, but the toxicology information of chlorothalonil and acetamiprid on bee larvae remain limited. Results: The no observed adverse effect concentration (NOAEC) of chlorothalonil and acetamiprid for honey bee larvae were 4 μg/mL and 2 μg/mL, respectively. Except for CarE, the enzymic activities of GST and P450 were not influenced by chlorothalonil at NOAEC, while chronic exposure to acetamiprid slightly increased the activities of the three tested enzymes at NOAEC. Further, the exposed larvae showed significantly higher expression of genes involved in a series of different toxicologically relevant process following, including caste development (Tor (GB44905), InR-2 (GB55425), Hr4 (GB47037), Ac3 (GB11637) and ILP-2 (GB10174)), immune system response (abaecin (GB18323), defensin-1 (GB19392), toll-X4 (GB50418)), and oxidative stress response (P450, GSH, GST, CarE). Conclusion: Our results suggest that the exposure to chlorothalonil and acetamiprid, even at concentrations below the NOAEC, showed potentially effects on bee larvae's fitness, and more important synergistic and behavioral effects that can affect larvae fitness should be explored in the further.

The sulfoximine insecticide sulfoxaflor exposure reduces the survival status and disrupts the intestinal metabolism of the honeybee Apis mellifera

Honeybees (Apis mellifera) are indispensable pollinators in agricultural production, biodiversity conservation, and nutrients provision. The abundance and diversity of honeybees have been rapidly diminishing, possibly related to the extensive use of insecticides in ecosystems. Sulfoxaflor is a novel sulfoximine insecticide that, like neonicotinoids, acts as a competitive modulator of nicotinic acetylcholine receptors (nAChR) in insects. However, few studies have addressed the negative effects of sulfoxaflor on honeybees at environmentally relevant concentrations. In the present study, adult workers were fed a 50% (w/v) of sugar solution containing different concentrations (0, 0.05, 0.5 and 2.0 mg/L) of sulfoxaflor for two weeks consecutively. The survival rates, food intake, and body weight of the honeybees significantly decreased after continuous exposure at higher doses (0.5 and 2.0 mg/L) of sulfoxaflor when compared with the control. The change in the metabolites in the honeybee gut was determined using high-throughput non-targeted metabolomics on day 14 after sulfoxaflor treatment. The results revealed that 24 and 105 metabolites changed after exposure to 0.5 and 2.0 mg/L sulfoxaflor, respectively, compared with that of the control groups. A total of 12 changed compounds including pregenolone and glutathione were detected as potential biomarkers, which were eventually found to be enriched in pathways of the steroid hormone biosynthesis (p = 0.0001) and glutathione metabolism (p = 0.021). These findings provide a new perspective on the physiological influence of sulfoxaflor stress in honeybees.

Chronic larval exposure to thiacloprid impairs honeybee antennal selectivity, learning and memory performances

The use of agricultural neonicotinoid insecticides has sub-lethal chronic effects on bees that are more prevalent than acute toxicity. Among these insecticides, thiacloprid, a commonly used compound with low toxicity, has attracted significant attention due to its potential impact on the olfactory and learning abilities of honeybees. The effect of sub-lethal larval exposure to thiacloprid on the antennal activity of adult honeybees (Apis mellifera L.) is not yet fully understood. To address this knowledge gap, laboratory-based experiments were conducted in which honeybee larvae were administered thiacloprid (0.5 mg/L and 1.0 mg/L). Using electroantennography (EAG), the impacts of thiacloprid exposure on the antennal selectivity to common floral volatiles were evaluated. Additionally, the effects of sub-lethal exposure on odor-related learning and memory were also assessed. The results of this study reveal, for the first time, that sub-lethal larval exposure to thiacloprid decreased honeybee antenna EAG responses to floral scents, leading to increased olfactory selectivity in the high-dose (1.0 mg/L) group compared to the control group (0 mg/L vs. 1.0 mg/L: p = 0.042). The results also suggest that thiacloprid negatively affected odor-associated paired learning acquisition, as well as medium-term (1 h) (0 mg/L vs. 1.0 mg/L: p = 0.019) and long-term memory (24 h) (0 mg/L vs. 1.0 mg/L: p = 0.037) in adult honeybees. EAG amplitudes were dramatically reduced following R-linalool paired olfactory training (0 mg/L vs. 1.0 mg/L: p = 0.001; 0 mg/L vs. 0.5 mg/L: p = 0.027), while antennal activities only differed significantly in the control between paired and unpaired groups. Our results indicated that exposure to sub-lethal concentrations of thiacloprid may affect olfactory perception and learning and memory behaviors in honeybees. These findings have important implications for the safe use of agrochemicals in the environment.

Alleviating effect of mulberry leaf 1-deoxynojirimycin on resistin-induced hepatic steatosis and insulin resistance in mice

Resistin is upregulated in obese humans and mice, and elevated serum resistin induces insulin resistance and hepatic steatosis. Previous studies have revealed that mulberry 1-deoxynojirimycin (DNJ) is important for a variety of physiological processes, especially carbohydrate and lipid metabolism. However, it remains unclear whether DNJ has a positive effect on insulin resistance and hepatic steatosis, and what the exact mechanism is. Male C57BL/6J mice were treated with resistin with or without DNJ. DNJ reversed the homeostasis model assessment of insulin resistance (HOMA-IR)-induced by resistin and significantly decreased triglyceride levels both in the serum and liver. A histological analysis demonstrated that lipid accumulation significantly decreased in the DNJ group compared to the resistin group. A mechanistic analysis showed that DNJ significantly inhibited the resistin-induced decline in enzyme activities of hormone-sensitive lipase (HSL) and hepatic lipase (HL) in serum and lipoprotein lipase (LPL) in liver. FAS and Acox13α were significantly altered by resistin but restored by DNJ. Furthermore, DNJ partially but significantly restored insulin-stimulated glucose uptake compared with the resistin group, suggesting that DNJ reversed the insulin sensitivity impaired by hyperresistinemia. Treatment of AML12 cells with DNJ significantly restored the expression level and phosphorylation of Akt. The transcriptional levels of InsR and IRS1, as well as the protein levels of InsR and Glut4 and phosphorylation of PI3K and GSK3β, were also normalized in the DNJ-treated group. In conclusion: mulberry DNJ significantly alleviated liver steatosis and insulin resistance in hyperresistinemia.

[Analysis of the factors influencing positive predictive value of noninvasive prenatal testing for chromosome aneuploidies]

Objective: To investigate the influence of Z-score and different risk factors on positive predictive value (PPV) of noninvasive prenatal testing (NIPT) for chromosome aneuploidies. Methods: A total of 81 838 NIPT samples from January 1, 2016 to May 31, 2021 in the First Affiliated Hospital of Zhengzhou University were retrospectively analyzed. Invasive prenatal diagnosis was applied to verify the diagnosis of NIPT-positive results and the corresponding PPV was calculated. The PPV of the samples with different Z-score were compared. The women were divided into high-risk group and non-high-risk group: high-risk group (n=39 114) included those with ultrasound soft index abnormalities, advanced maternal age or high risk for maternal serum screening, while non-high-risk group (n=42 724) included those with intermediate risk for maternal serum screening or no indications. The differences of the PPV between these two groups were compared. Finally, the comprehensive influence of Z-score and different risk factors on PPV were analyzed. Results: A total of 471 high-risk cases were detected by NIPT results, including 362 cases of trisomy 21, 77 cases of trisomy 18 and 32 cases of trisomy 13. For trisomy 21, trisomy 18 and trisomy 13, there were 226 cases, 46 cases and 6 cases which were confirmed via invasive prenatal diagnosis respectively. The corresponding PPV were 79.3% (226/285), 82.1% (46/56) and 27.3% (6/22), respectively. PPV of trisomy 21 and trisomy 18 were positively correlated with the corresponding Z-score (r=0.92, 0.62, all P<0.05), while trisomy 13 could not be analyzed due to the small sample size. The PPV of high-risk group was 85.2% (207/243), which was higher than that of the non-high-risk group with PPV of 59.2%(71/120, χ²=30.30, P<0.01). When the Z-score was between 3-<4 and 4-<5, the PPV of the high-risk group were 46.2%(12/26)and 62.5%(15/24) respectively, which were higher than those of the non-high-risk group [16.0%(4/25) and 14.3%(3/21), χ²=4.10, 8.90, all P<0.05]. With the increase of Z-score, there was no significant difference in PPV between the two groups (all P>0.05). Conclusions: The PPV of trisomy 21 and trisomy 18 are positively correlated with Z-score. The PPV of high-risk group is higher than that of non-high-risk group. The combination of Z-score and other risk factors may provide more accurate genetic counseling for those with NIPT positive results.

Recovery and genetic characterization of black queen cell virus

Black queen cell virus (BQCV) is a severe threat to the honeybee (Apis mellifera) worldwide. Although several BQCV strains have been reported in China, the molecular basis for BQCV pathogenicity has not been well understood. Thus, a reverse genetic system of BQCV is required for studying viral replication and its pathogenic mechanism. Here, the complete genome sequence of BQCV was obtained from honeybees using reverse transcription PCR (RT-PCR), namely a BQCV China-GS1 strain (KY741959). Then, a phylogenetic tree was built to analyse the genetic relationships among BQCV strains from different regions. Our results showed that the BQCV China-GS1 contained two ORFs, consistent with the known reference strains, except for the BQCV China-JL1 strain (KP119603). Furthermore, the infectious clone of BQCV was constructed based on BQCV China-GS1 using a low copy vector pACYC177 and gene recombination. Due to the lack of culture cells for bee viruses, we infected the healthy bees with infectious clone of BQCV, and the rescued BQCV resulted in the recovery of recombinant virus, which induced higher mortality than those of the control group. Immune response after inoculated with BQCV further confirmed that the infectious clone of BQCV caused the cellular and humoral immune response of honeybee (A. mellifera). In conclusion, the full nucleotide sequence of BQCV China-GS1 strain was determined, and the infectious clone of BQCV was constructed in this study. These data will improve the understanding of pathogenesis and the host immune responses to viral infection.

[A study on longitudinal changes in white matter microstructure of parents who have lost their only child based on diffusion tensor imaging and its relationship with symptoms of posttraumatic stress disorder]

Objective: To investigate the longitudinal changes of white matter microstructural based on diffusion tensor imaging in parents who lost their only child without psychiatric disorders and its relationship with symptoms of posttraumatic stress disorder (PTSD). Methods: Parents who had who lost their only child and without psychiatric disorders in Jiangsu Province, from September 2016 to March 2017, were retrospectively collected (TENP group, 32). MRI scans were performed at baseline and at the end of 5-year follow-up, and the Clinician Administered PTSD Scales (CAPS) were used for assessing the severity of symptoms. Additionally, sex, age and education level matched healthy subjects were recruited as healthy controls (control group, 27) and underwent MRI scanning using the same protocol. The differences of fractional anisotropy (FA) values between TENP group and control group at baseline were analyzed by using Tract-based spatial statistics method, and the brain areas of lateral differences were used as the regions of interest for longitudinal follow-up analysis of TENP group. Partial correlation analysis was used to evaluate the relationship between FA values changes in longitudinal differences in brain regions and CAPS scores. Results: Compared with the control group, FA values of the right cingulate gyrus, Uncinate fasciculus, superior longitudinal fasciculus, corticospinal tract, Inferior fronto-occipital fasciculus, Inferior longitudinal fasciculus and forceps major in TENP group were decreased at baseline ((0.613±0.032) vs (0.631±0.034), (0.539±0.048) vs (0.563±0.045), (0.534±0.033) vs (0.558±0.039), (0.560±0.038) vs (0.580±0.030), (0.519±0.023) vs(0.549±0.024), (0.489±0.038) vs (0.518±0.027), (0.499±0.027) vs (0.533±0.032); all P<0.05). From baseline to follow-up, scores of trauma reexperience symptoms and avoidance/numbness symptoms were decreased ((5.2±2.8) vs (8.1±4.9), (4.0±3.2) vs (6.6±5.4); all P<0.05); FA values of the right corticospinal tract, Inferior fronto-occipital fasciculus, Inferior longitudinal fasciculus and forceps major were decreased ((0.523±0.049) vs (0.537±0.049), (0.568±0.052) vs (0.590±0.050), (0.540±0.063) vs (0.559±0.059), (0.520±0.059) vs (0.547±0.059); all P<0.05); The decrease of FA values of the right Inferior fronto-occipital fasciculus and right Inferior longitudinal fasciculus was negatively correlated with the decrease of avoidance/numbness symptoms scores (r=-0.458, -0.374, respectively, all P<0.05). Conclusions: The trauma of parents who lost their only child can result in impaired microstructural integrity of white matter. As the post-traumatic time goes by, parents who have lost their only child do not develop to PTSD and other psychiatric disorders, and the clinical symptoms are alleviated, the damage of the white matter microstructure continued to progress.

Chlorothalonil alters the gut microbiota and reduces the survival of immature honey bees reared in vitro

BACKGROUND

Chlorothalonil is a nonsystemic fungicide, and it is one of the most widely detected pesticides in bee hives. The effect of chlorothalonil on the survival, weight, and gut microbiota of immature Apis mellifera L. reared in vitro was studied.

RESULTS

Larvae were fed 1, 2, 4, 8, and 16 μg/mL chlorothalonil and compared with larvae fed the negative control (diet without any additives), positive control (45 mg/L dimethoate), and solvent control (2% acetone). Compared with the control groups, the survival of the 2, 4, 8, and 16 μg/mL chlorothalonil treatments was significantly reduced. The no-observed-adverse-effect concentration of chlorothalonil was 1 μg/mL. Chlorothalonil had no significant effect on larval weight. The gut bacterial community composition of newly emerged bees was determined by PacBio 16S rDNA gene sequencing. linear discriminant analysis effect size (LEFSe) analysis showed that Pseudomonadales and Burkholderiales were affected by exposure to chlorothalonil.

CONCLUSION

Chlorothalonil reduced the survival of honey bee larvae and altered the gut microbiota of newly emerged bees. The risk of pesticides to honey bees is related to their toxicity and exposure dose.

[Analysis of COL1A1 gene variation and clinical prevention and treatment in patients with Van der Hoeve syndrome]

Objective: To investigate the clinical phenotype, treatment and prevention of Van der Hoeve syndrome, and analyze the variation characteristics of its related gene COL1A1. Methods: Hearing and sequencing data of syndromic deafness patients who had undergone genetic testing for deafness at the Chinese People's Liberation Army General Hospital since January 2008 to October 2020 were retrospectively reviewed. The variation of the COL1A1 gene and return visits to traceable patients and families were summarized, the disease progress and clinical treatment effects were analyzed, and the prevention strategies were discussed. Results: A total of 7 patients with COL1A1 gene mutation underwent clinical intervention. The mutation sites were c.1342A>T (p.Lys448*), c.124C>T (p.Gln42*), c.249insG(p.Ala84*), c.668insC(p.Gly224*), c.2829+1G>C, c.1081C>T (p.Arg361*), c.1792C>T (p.Arg598*), of which c.1081C>T and c.1792C>T had been previously reported, and the remaining 5 were novo mutations that have not been reported. All the 7 probands underwent stapes implantation and received genetic counseling and prevention guidance. Conclusions: Van der Hoeve syndrome belongs to osteogenesis imperfecta type Ⅰ. The disease has high penetrance. Timely surgical intervention for hearing loss can improve the life quality in patients. Accurate genetic counseling and preimplantation genetic diagnosis can achieve the primary prevention for the disease.

[Reconstruction of complex tissue defects in temporal region: report of 3 cases]

Objective: To discuss the techniques and repairing methods of various degree of compound tissue defects in the auriculotemporal region. Methods: Retrospective analysis was conducted on three cases of different repairing methods for huge compound tissue defects in different degrees in the auriculotemporal region after the resection of the malignant tumor or sinus tract due to repeated infection in our hospital. Results: Following total removal of the tumors or sinus tract in all patients, we applied retroauricular lingual flap transfer repairing, latissimus dorsi flap free transfer repairing and vascular anastomosis, scalp tissue expansion in stage Ⅰ, then repairing the lesion with expanded scalp and filling the huge mastoid cavity with abdominal fat in stage Ⅱ, respectively, according to the characteristics of compound tissue defects in the auriculotemporal region. All free flaps survived well. Conclusions: The anatomy of the auricular-temporal area is complex and involves important vascular and neural structures of head and neck and lateral skull base. The huge composite tissue defect following auriculotemporal region surgery, which is composed of skin, muscle and bone tissue, needs to be repaired in one stage. Therefore, flexible repairing methods should be chosen based on different situations, for attaining the goal of completely removing tumor and lesions, and then, covering the operation cavity.

A combination of Tropilaelaps mercedesae and imidacloprid negatively affects survival, pollen consumption and midgut bacterial composition of honey bee

Tropilaelaps mercedesae is not only a major threat to honey bees in Asia but also a potential risk to global apiculture due to trade. Imidacloprid is a systemic insecticide that negatively affects individual bees. Moreover, the health of honey bees may be threatened by imidacloprid exposure and T. mercedesae infestation. We studied the effects of T. mercedesae and imidacloprid on the survival, food consumption and midgut bacterial diversity of Apis mellifera in the laboratory. Illumina 16S rRNA gene sequencing was used to determine the bacterial composition in the honey bee midgut. T. mercedesae decreased survival in parasitized honey bees compared with nonparasitized honey bees, but there was no significant difference in food consumption. The imidacloprid 50 μg/L diet significantly decreased syrup consumption of A. mellifera compared with the control diet. The combination of T. mercedesae infestation and imidacloprid 50 μg/L exposure reduced survival and increased pollen consumption of A. mellifera. T. mercedesae infestation or a combination of T. mercedesae infestation and exposure to 25 μg/L imidacloprid affected the midgut bacterial composition of honey bees. T. mercedesae infestation and imidacloprid exposure may reduce the survival and affect honey bee health.

The Larvicidal and Adulticidal Effects of Selected Plant Essential Oil Constituents on Greater Wax Moths

Some plant essential oil constituents, such as monoterpenoids and phenylpropanoids, are promising insecticides in some situations and for certain insect pests. They vary in their toxicity, depending on the target insect. Moths (Lepidoptera) appear susceptible to these compounds, making them of promise for use against greater wax moths (Galleria mellonella Fabricius, (Lepidoptera: Pyrallidae), GWM), an important pest of western honey bee (Apis mellifera Linnaeus. (Hymenoptera: Apidae)) colonies. We determined the LC50 for GWM larvae or LD50 for GWM adults of select compounds (thymol, carvacrol, (S)-(+)-carvone, estragole, citral, linalool, (S)-(-)-limonene, and γ-terpinene). Concentrations between 8 and 2,266 µg/cm3 were mixed into the diets of GWM larvae and doses ranging between 0.08 and 70.3 mg per adult were applied topically to the abdomens of GWM adults. Lethal concentrations and doses were calculated after of 72 h of exposure. All eight compounds showed insecticidal activity against all tested stages of GWMs. Thymol (LC50 µg/cm3 (95% CI) = 21 [9-56], carvacrol = 46 [26-79], citral = 63 [30-134], and carvone = 76 [33-201]) had the highest toxicity toward GWM larvae. The hydrocarbons limonene (296 [231-377]), estragole (466 [354-611]), and γ-terpinene (729 [630-857]) had the lowest toxicity toward GWM larvae. Thymol had the highest toxicity towards GWM adults (LD50 (CI) = 0.5 [0.4-0.8] mg/adult). However, carvacrol (11.6 [10.1-13.6]), linalool (12.9 [9.3-17.8]), and limonene (15.8 [13.1-19.2]) were less toxic to GWM larvae. Our data show that select plant essential oil constituents are promising controls of GWM.

Effects of Bt Cry78Ba1 Toxin on Larvae and Adults of Apis mellifera (Hymenoptera: Apidae)

Cry78Ba1 is Bacillus thuringiensis Berliner (Bacillales: Bacillaceae) (Bt) protein found with high insecticidal activity against the piercing-sucking insect Laodelphax striatellus Fallén (Homoptera: Delphacidae) and has broad application prospects for control of the rice planthopper. As honey bees may be exposed to Bt Cry78Ba1 rice pollen by feeding, we evaluated the risk of Bt Cry78Ba1 toxin to Apis mellifera L. workers. A dietary exposure experiment was conducted on worker larvae and adults under controlled laboratory conditions to examine the effects of Cry78Ba1 toxin on honey bees. Worker bee larvae were fed a diet containing Cry78Ba1 toxin (0.01, 0.1, 1, and 10 mg/liter) on day 2 through day 5 after grafting, and adults were exposed to syrup containing Cry78Ba1 for up to 16 d. Negative control (no test substance added), solvent control (1 mM Tris-HCl), and positive control (dimethoate 45 mg/liter for the larva test, 1 and 45 mg/liter for the adult test) groups were established. Compared with the negative control, larvae and adults that consumed food containing Cry78Ba1 toxin exhibited no significant differences in survival, larval weight, or pollen or syrup consumption. This result indicates that chronic oral exposure to Cry78Ba1 toxin has no negative effects on honey bees at the maximum tested concentration.

[Surgical strategy of minimally invasive cochlear implantation]

Cochlear implantation is currently the most effective treatment for patients with severe-to-profound sensorineural hearing loss. How to achieve minimally invasive treatment, preserve the residual hearing, and further improve curative effect and reduce surgical complications is the goal of cochlear implantation practice. This article introduces the minimally invasive cochlear implantation technique in terms of the idea of minimally invasive operation, the advantages of electric acoustic stimulation, the key points of electrode implantation technique, the design of surgical incision, and the precise processing of perioperative period. This technique not only has the merits of less operative damage and better hearing and speech rehabilitation after surgery, but also reserves favorable structures and function for the future application of gene therapy and hair cell regeneration technique. Therefore, it is strongly recommended for further promotion in clinical practice.

[Confirmation and analysis of 2 398 positive results of cell-free fetal DNA]

Objective: To explore the clinical application value and accuracy of cell-free fetal DNA (cff-DNA) technique in prenatal screening. Methods: The results of quantitative fluorescent PCR (QF-PCR) and karyotype of amniotic fluid cells were analyzed retrospectively in 2 398 monocyesis pregnant women who had been amniocentesis at the First Affiliated Hospital of Zhengzhou University from May 2013 to December 2019, and the results of 359 cases who had been examined by single-nucleotide polymorphism array (SNP array). Results: Cff-DNA test of 2, 398 cases indicated 987 cases of trisomy 21, 351 cases of trisomy 18, 135 cases of trisomy 13, 566 cases of sex chromosome abnormality, and 359 cases of other chromosome abnormality. Chromosome karyotype analysis detected 826 cases of trisomy 21, 213 cases of trisomy 18, 17 cases of trisomy 13, 221 cases of sex chromosome abnormality, and 26 cases of other chromosome abnormality. The detection rate were 83.69% (826/987), 60.68% (213/351), 12.59% (17/135), 39.04% (221/566) and 7.24% (26/359), respectively. QF-PCR detected 1 046 cases of trisomy and 188 cases of sex chromosomes abnormality, and the detection rate was 99.05% (1 046/1 056) and 85.07% (188/221), respectively. Compared with the abnormal number detected by chromosome karyotype analysis, 10 cases of trisomeric chimerism and 24 cases of sex chromosome were missed by QF-PCR. Among the 359 other chromosomal abnormalities detected by SNP array, 64 cases were consistent with the results of cff-DNA, and the detection rate was 17.83% (64/359), which was 10.59% higher than the karyotype result. Conclusions: Karyotype analysis is the gold standard for diagnosing chromosomal abnormalities. QF-PCR could diagnose common chromosome aneuploidy rapidly and accurately, and it could be used as an auxiliary detection technique for karyotype analysis. The incidence of sex chromosome chimerism is high, so missed diagnosis should be warned. SNP array could be given priority to verify chromosome microdeletion or microduplication detected by cff-DNA.

Self-made Salmonella Pullorum agglutination antigen development and its potential practical application

Pullorum disease caused by Salmonella Pullorum is one of the most important infectious diseases in the poultry industry worldwide, which leads to serious economic losses in many developing countries because of its high mortality rate in young chicks. The traditional slide agglutination test with low cost, fast reaction, and on-site detection has been widely used in the diagnosis of Pullorum disease. However, in practice, the test performance is with the disadvantages of false positive results and unstable detection results. In this paper, we developed self-made agglutination antigens prepared by local isolates in the poultry farm and compare the detection performance with commercial agglutination antigens (China Institute of Veterinary Drug Control) and Group D Salmonella ELISA kit (BioChek UK Ltd). The results of detecting 200 serum samples indicated that the consistency of commercial agglutination antigen detecting in 2 times was only 79.5%. Using the ELISA kit as the reference method, the commercial agglutination antigen detecting results of the Kappa test were only moderately consistent (0.58 ∼ 0.59). Meanwhile, positive and total coincidence rates of the self-made agglutination antigen test with more reliable repeat could reach 97.4 and 88%, respectively, and the result of Kappa test was highly consistent (0.75). The Receiver Operating Characteristic curve analysis clarified that the area under the receiver-operating-characteristic curve values of self-made and commercial agglutination antigen tests could reach 0.861 and 0.804, respectively. These results were coincident when detecting known positive serum from the infected chickens. It's worth mentioning that the visible positive reaction of self-made agglutination antigen test appeared faster and stronger than commercial antigen test. In conclusion, self-made Salmonella Pullorum agglutination antigen developed in this study was much better than commercial agglutination antigen and is expected to be a valuable tool in the diagnosis of the epidemiology of Salmonella Pullorum.

Acute and chronic toxicity of acetamiprid, carbaryl, cypermethrin and deltamethrin to Apis mellifera larvae reared in vitro

BACKGROUND

The effects of exposing Apis mellifera larvae to common insecticides were tested in the laboratory.

RESULTS

The acute toxicity values of the four insecticides that we tested ranged from high toxicity to low toxicity: deltamethrin > cypermethrin > carbaryl > acetamiprid. The NOAEC (no observed adverse effect concentration) values of the chronic toxicity tests for each compound are 5 mg L^-1 for acetamiprid, 2 mg L^-1 for carbaryl, 1 mg L^-1 for cypermethrin, and 0.2 mg L^-1 for deltamethrin.

CONCLUSION

According to the risk quotient (RQ) values of acute and chronic toxicity that we obtained, the risk is acceptable at exposure rates that have been identified in the field. Overall, our results are valuable for evaluating the acute and chronic toxicities of these insecticides to developing honey bees. © 2019 Society of Chemical Industry.

Computer-generated photorealistic hologram using ray-wavefront conversion based on the additive compressive light field approach

The conventional computer-generated hologram reconstructing photorealistic three-dimensional (3D) images based on ray-wavefront conversion has the disadvantage of spatio-angular resolution trade-off. In this Letter, we propose for the first time, to the best of our knowledge, a computer-generated photorealistic hologram without spatio-angular resolution trade-off based on the additive compressive light field (CLF) approach. The original light field is compressed into multiple layer images through numerical optimization based on the additive light field principle. Then, by independently calculating the wave propagation from each layer image to the hologram plane and adding them together, a CLF hologram is generated. Since the CLF information is presented through a holographic method, the advantage of high resolution in CLF is preserved while the limitation of the number of physically stacked layers (such as liquid crystal displays) is removed, leading to higher quality, larger depth of field, and higher brightness compared with a conventional CLF display. The proposed method is verified with a photorealistic optical experiment.

The effect of Bt Cry9Ee toxin on honey bee brood and adults reared in vitro, Apis mellifera (Hymenoptera: Apidae)

The effects of Bt Cry9Ee toxin on honey bee, Apis mellifera L., survival, developmental rate, larval weight, pollen consumption, and midgut bacterial diversity were tested in the laboratory. Honey bee larvae and adults were reared in vitro and fed a diet that contained Cry9Ee toxin at 0.01, 0.1, 1, and 10 mg/L. Cry9Ee toxin 0.01, 0.1, and 1 mg/L in diet used in this study may represent a value closer to field relevance and the highest concentration is unlikely to be encountered in the field and thus represent a worst case scenario. The dependent variables were compared for groups of honey bees feeding on treated diet and those feeding on negative control (no addition of a test substance), solvent control (0.01 mM Na₂CO₃), and positive control diet (dimethoate 45 mg/L). Bt Cry9Ee toxin did not affect survival or larval weight, and the result was great confidence in accepting the null hypothesis by power analysis. The effect on development rates and pollen consumption were the inconclusive results because the post-hoc power was less than 0.8. Furthermore, the midgut bacterial structure and compositions were determined using high-throughput sequencing targeting the V3-V4 regions of the 16S rDNA. All core honey bee intestinal bacterial class such as γ-Proteobacteria, Actinobacteria, α-Proteobacteria, Bacilli, β-Proteobacteria, and Bacteroidia were detected, and no significant changes were found in the species diversity and richness between Cry9Ee treatments and laboratory control.

Effects of Tropilaelaps mercedesae on midgut bacterial diversity of Apis mellifera

Tropilaelaps mercedesae is an ectoparasite of Apis mellifera in Asia and is considered a major threat to honey bee health. Herein, we used the Illumina MiSeq platform 16S rDNA Amplicon Sequencing targeting the V3-V4 regions and analysed the effects on the midgut bacterial communities of honey bees infested with T. mercedesae. The overall bacterial community in honey bees infested with T. mercedesae were observed at different developmental stages. Honey bee core intestinal bacterial genera such as Gilliamella, Lactobacillus and Frischella were detected. Tropilaelapsmercedesae infestation changed the bacterial communities in the midgut of A. mellifera. Tropilaelapsmercedesae-infested pupae had greatly increased relative abundances of Micrococcus and Sphingomonas, whereas T. mercedesae-infested 15-day-old workers had significantly reduced relative abundance of non-core microbes: Corynebacterium, Sphingomonas, Acinetobacter and Enhydrobacter compared to T. mercedesae-infested newly emerged bees. The bacterial community was significantly changed at the various T. mercedesae-infested developmental stages of A. mellifera. Tropilaelapsmercedesae infestation also changed the non-core bacterial community from larvae to newly emerged honey bees. Bacterial communities were significantly different between T. mercedesa-infested and non-mite-infested 15-day-old workers. Lactobacillus was dominant in T. mercedesae-infested 15-day-old workers compared to non-mite-infested 15-day-old workers.

[PTPN11 and the deafness]

Summary PTPN11 gene encodes tyrosine phosphatase SHP-2 which locates on chromosome 12（12q24.1）, expresses in most embryonic and adult tissues, and plays pivotal roles in cell proliferation, differentiation, survival and cell death. SHP-2 apparently participates in signaling events downstream of RAS-MAPK and JAK/STAT. Diseases related to PTPN11 gene mutations include the Noonan syndrome（NS） and the NS with Multiple Lentigines（NSML）. Both NS and NSML contain the phenotypes of deafness, craniofacial anomalies, short stature, congenital heart defects, skin disorders, ophthalmologic abnormalities and cancer predisposition.

[Case report and diagnosis of Noonan syndrome with multiple lentigines with deafness as its main clinical feature]

Summary Noonan syndrome with multiple lentigines（NSML） is a disorder with syndromic hearing loss. Abnormalities of other systems in NSML have received increasing attention, but hearing loss is rarely concerned. And due to the incomplete phenotype, some patients with NSML maybe missed or maybe confused with other syndromic deafness such as Waardenburg syndrome. Our study will familiarize more otolaryngologists with Leopard syndrome. A 5-year-old boy with bilateral sensorineural hearing loss and numerous symmetrically distributed dark brown macules that had good effect of cochlear implantation was collected in this study. And his father had bilateral sensorineural hearing loss and numerous symmetrically distributed dark brown macules. Waardenburg syndrome was initially diagnosed by clinical phenotype and its molecular etiology was confirmed by gene diagnosis. Waardenburg syndrome-related deafness genes and 131 known deafness genes were not identified by second-generation sequencing. Whole-exon sequencing was performed for 4 individuals in the family and the results were confirmed by Sanger sequencing. This study confirmed the diagnosis by identifying a disease-causing mutation in the PTPN11 gene, which was a heterozygous missense mutation at p. Tyr279Cys（c. 836A>G）. The mutation co-segregated with hearing loss in the family. Our results demonstrated that hearing loss in this family was caused by heterozygous mutations in PTPN11. These cases will familiarize more otolaryngologists with NSML, and they emphasize the importance of considering NSML as a possible cause of hearing problems.

Effects of three common pesticides on survival, food consumption and midgut bacterial communities of adult workers Apis cerana and Apis mellifera

The acute and chronic toxicity of 3 common pesticides, namely, amitraz, chlorpyrifos and dimethoate, were tested in Apis mellifera and Apis cerana. Acute oral toxicity LC₅₀ values were calculated after 24 h of exposure to contaminated syrup, and chronic toxicity was tested after 15 days of exposure to 2 sublethal concentrations of pesticides. The toxicity of the tested pesticides to A. mellifera and A. cerana decreased in the order of dimethoate > chlorpyrifos > amitraz. A. mellifera was slightly more sensitive to chlorpyrifos and dimethoate than A. cerana, while A. cerana was more sensitive to amitraz than A. mellifera. Chronic toxicity tests showed that 1.0 mg/L dimethoate reduced the survival of the two bee species and the food consumption of A. mellifera, while 1.0 mg/L amitraz and 1.0 mg/L chlorpyrifos did not affect the survival or food consumption of the two bee species. The treatment of syrup with amitraz at a concentration equal to 1/10th of the LC₅₀ value did not affect the survival of or diet consumption by A. mellifera and A. cerana; however, chlorpyrifos and dimethoate at concentrations equal to 1/10th of their respective LC₅₀ values affected the survival of A. cerana. Furthermore, intestinal bacterial communities were identified using high-throughput sequencing targeting the V3V4 regions of the 16S rDNA gene. All major honey bee intestinal bacterial phyla, including Proteobacteria (62.84%), Firmicutes (34.04%), and Bacteroidetes (2.02%), were detected. There was a significant difference in the microbiota species richness of the two species after 15 days; however, after 30 days, no significant differences were found in the species diversity and richness between A. cerana and A. mellifera exposed to 1.0 mg/L amitraz and 1.0 mg/L chlorpyrifos. Overall, our results confirm that acute toxicity values are valuable for evaluating the chronic toxicity of these pesticides to honey bees.

Volatiles from Different Instars of Honeybee Worker Larvae and Their Food

(E)-β-Ocimene was the only volatile chemical found to be emitted by whole, live worker larvae of Apis mellifera L. when sampling in the vapor phase. In addition to (E)-β-ocimene, there is evidence for the existence of other volatiles, but the changes in their composition and contents remain unknown during larval development, as are their differences from larvae to larval food. We investigated volatile components of worker larvae and larval food using solid phase dynamic extraction (SPDE) coupled with gas chromatography-mass spectrometry (GC-MS). Nine compounds were identified with certainty and six tentatively, including terpenoids, aldehydes, hydrocarbons, an ester and a ketone. The contents of volatiles in the second-instar worker larvae differ greatly from those in larvae of other stages. This is mainly attributable to terpenoids, which resulted in the second-instar worker larvae having significantly higher amounts of overall volatiles. Larval food contained significantly higher amounts of aldehydes and hydrocarbons than the corresponding larvae from the fourth to fifth-instar. We discovered volatiles in worker larvae and their food that were never reported before; we also determined the content changes of these volatiles during larval development.

[Clinical diagnosis and surgical management of 110 cases of facial nerve schwannomas]

Objective: To elucidate the clinical behavior, causes of misdiagnosis, surgical management, and outcomes of facial nerve schwannomas (FNS). Methods: A retrospective review in Chinese People's Liberation Army General Hospital from January 1, 2002 to December 31, 2015 was carried out and evaluated 110 patients with FNS, including 50 males and 60 females, aged 16-67 years old. The appropriate surgical strategy was selected based on each patient's clinical manifestations, facial nerve function, and imaging characteristics. After surgery, patients received follow-up visits to assess their facial nerve functions, with the effect of treatment compared to the reality before surgery. The Kruskal-Wallis H test was used to distinguish between the pre- and post-operation facial nerve functions in patients who had different facial nerve functions before the operations. Results: 110 cases of FNS mainly presented with facial paralysis, hearing loss, tinnitus, otalgia, dizziness, and facial spasm. 20 of the cases were misdiagnosed as Bell's Palsy, 6 were mistaken for chronic otitis media/cholesteatoma with radical mastoidectomy, 3 were mistaken for Meniere's disease, 1 was misdiagnosed as petrous bone cholesteatoma, and 4 were mistaken for acoustic neuroma. 81.8 % (90/110) of the patients had multiple segments of the facial nerve, including the vertical segment of the facial nerve, accounting for 65.5% (72/110), followed by the labyrinthine/geniculate segment, for 61.8% (68/110), and the horizontal segment, for 55.5% (61/110). The appropriate surgical approaches were chosed based on the sizes and scopes of the tumors evaluated by imaging: transmastoid approach in 73 cases, translabyrinthe approach in 14 cases, middle cranial fossa approach in 13 cases, retrosigmoid approach in 3 cases, transmastoid-middle cranial fossa approach in 3 cases, and transmastoid-neck approach in 4 cases, with all the patients undergoing a total/subtotal resection of the tumor. Eighty-seven patients had their facial nerves reconstructed. Among them, 6 received facial nerve end-to-end anastomosis, 55 received great auricular nerve graft, and 26 were subjected to facial nerve-hypoglossal nerve anastomosis. Because of long histories, facial muscle atrophies, or other reasons, the remaining patients were not received facial nerve reconstruction. The House-Brackmann(H-B) grading scale was used to evaluate the facial nerve function pre- and post-operation. Patients with better facial nerve functions and shorter history of facial paralysis before operation would get relatively better facial nerve function. The before and after operation comparisons revealed that the recovery of the facial nerve functions in patients with H-B Ⅰ-Ⅲ was better than the improvement in patients with H-B Ⅳ-Ⅴ. The difference was statistically significant (Kruskal-Wallis H test, H=8.508, P<0.05). Conclusions: The diagnosis of patients with unknown facial paralysis, hearing loss, and tinnitus should take into account the possibility of FNS. CT and other imaging examinations of the temporal bone can avoid misdiagnosis and determine the tumor size and extent of lesions, as well as provide the basis for the choice of the surgical approach. After tumors have been completely resected, facial nerve reconstruction can be performed simultaneously, according to the defect of the nerve.

Chronic toxicity of clothianidin, imidacloprid, chlorpyrifos, and dimethoate to Apis mellifera L. larvae reared in vitro

BACKGROUND

The effects of chronic exposure to two neonicotinoids (clothianidin and imidacloprid) and two organophosphates (chlorpyrifos and dimethoate) on survival, developmental rate and larval weight of honey bee larvae reared in vitro were determined. Diets containing chemicals were fed to larvae with the range of concentrations for each compound based on published acute toxicity experiments and residues found in pollen and nectar, both components of the larval diet.

RESULTS

Four concentrations of each compound and controls were tested: chlorpyrifos: 0.5, 0.8, 1.2, 8 mg/L; clothianidin: 0.1, 0.4, 2, 10 mg L^-1 ; dimethoate: 0.02, 1, 6, 45 mg L^-1 ; imidacloprid: 0.4, 2, 4, 10 mg L^-1 ; positive control: dimethoate (45 mg L^-1 ); solvent control: acetone or methanol; and negative control. A significant decrease in survival, relative to the solvent control, occurred in the 0.8, 1.2 and 8 mg L^-1 chlorpyrifos, 0.4, 2 and 10 mg L^-1 clothianidin, and 45 mg L^-1 dimethoate diets, but not the imidacloprid diets.

CONCLUSION

The treatment of larval diets with clothianidin, dimethoate and imidacloprid did not affect survival, developmental rate, or weight of immature honey bees; however, treatment with chlorpyrifos did. Overall, our results are valuable for evaluating the chronic toxicity of these pesticides to developing honey bees. © 2018 Society of Chemical Industry.

The impacts of chlorothalonil and diflubenzuron on Apis mellifera L. larvae reared in vitro

Chlorothalonil is a broad-spectrum fungicide and diflubenzuron is an insect growth regulator used to control many insect larvae feeding on agricultural, forest and ornamental plants. Honey bee larvae may be exposed to both via contaminated pollen, in the form of beebread, added to their diet by their adult nurse sisters. In this study, we determined how single (acute: 72 h mortality) and repeated (chronic: mortality until emergence as adults) exposure to chlorothalonil and diflubenzuron in their diet affected honey bee larvae reared in vitro. The tested doses of chlorothalonil (20, 100, or 200 mg/L) did not impact 72 h larval mortality acutely relative to that of the solvent control. The 72 h mortality of larvae exposed to 1.6 mg/L and higher doses of diflubenzuron acutely in their diet (47.2-63.9% mortality) was significantly higher than that of larvae fed the solvent control, with no predictable dose dependent pattern observed. In the chronic toxicity tests, consuming an artificial diet with 30 or 100 mg/L chlorothalonil and 0.8, 1.3 or 2 mg/L diflubenzuron significantly lowered the survival of honey bee larvae over that of larvae feeding on the solvent control diet. We calculated risk quotients (RQs) for both compounds using the data we generated in our experiments. Collectively, the RQs suggest that neither compound is likely to affect larval mortality directly at field relevant doses given that pollen composes only a fraction of the total larval diet. Nevertheless, our data do not preclude any sublethal effects that chronic exposure to either compound may cause.

The Herbicide Glyphosate Negatively Affects Midgut Bacterial Communities and Survival of Honey Bee during Larvae Reared in Vitro

Effects of glyphosate on survival, developmental rate, larval weight, and midgut bacterial diversity of Apis mellifera were tested in the laboratory. Larvae were reared in vitro and fed diet containing glyphosate 0.8, 4, and 20 mg/L. The dependent variables were compared with negative control and positive control (dimethoate 45 mg/L). Brood survival decreased in 4 or 20 mg/L glyphosate treatments but not in 0.8 mg/L, and larval weight decreased in 0.8 or 4 mg/L glyphosate treatments. Exposure to three concentrations did not affect the developmental rate. Furthermore, the intestinal bacterial communities were determined using high-throughput sequencing targeting the V3-V4 regions of the 16S rDNA. All core honey bee intestinal bacterial phyla such as Proteobacteria (30.86%), Firmicutes (13.82%), and Actinobacteria (11.88%) were detected, and significant changes were found in the species diversity and richness in 20 mg/L glyphosate group. Our results suggest that high concentrations of glyphosate are deleterious to immature bees.

Enhancement of chronic bee paralysis virus levels in honeybees acute exposed to imidacloprid: A Chinese case study

Though honeybee populations have not yet been reported to be largely lost in China, many stressors that affect the health of honeybees have been confirmed. Honeybees inevitably come into contact with environmental stressors that are not intended to target honeybees, such as pesticides. Although large-scale losses of honeybee colonies are thought to be associated with viruses, these viruses usually lead to covert infections and to not cause acute damage if the bees do not encounter outside stressors. To reveal the potential relationship between acute pesticides and viruses, we applied different doses of imidacloprid to adult bees that were primarily infected with low levels (4.3×10⁵ genome copies) of chronic bee paralysis virus (CBPV) to observe whether the acute oral toxicity of imidacloprid was able to elevate the level of CBPV. Here, we found that the titer of CBPV was significantly elevated in adult bees after 96h of acute treatment with imidacloprid at the highest dose 66.9ng/bee compared with other treatments and controls. Our study provides clear evidence that exposure to acute high doses of imidacloprid in honeybees persistently infected by CBPV can exert a remarkably negative effect on honeybee survival. These results imply that acute environmental stressors might be one of the major accelerators causing rapid viral replication, which may progress to cause mass proliferation and dissemination and lead to colony decline. The present study will be useful for better understanding the harm caused by this pesticide, especially regarding how honeybee tolerance to the viral infection might be altered by acute pesticide exposure.

Chronic toxicity of amitraz, coumaphos and fluvalinate to Apis mellifera L. larvae reared in vitro

The effects of chronic exposure to common acaricides on Apis mellifera survival, developmental rate and larval weight were tested in the laboratory. Larvae were reared in vitro and fed a diet containing amitraz: 1.5, 11, 25 and 46 mg/L; coumaphos: 1.8, 6, 8 and 25 mg/L; or fluvalinate: 0.1, 1, 2.4 and 6 mg/L. The dependent variables were compared for groups feeding on treated diets and control diets: positive control, 45 mg/L dimethoate; solvent control; and negative control. Bee survival decreased in the 46 mg/L amitraz and 25 mg/L coumaphos treatments but not in any fluvalinate treatment. Furthermore, the developmental rate decreased in individuals treated with 46 mg/L amitraz. In our study, larvae exposed to acaricides at concentrations similar to maximum residue in pollen and honey/nectar had no detectable change in survival or developmental rate. Given that pollen and honey/nectar represent only a small part of larval diet, we suggest that residues of amitraz, coumaphos and fluvalinate at the levels we tested are unlikely to impact immature worker bee survival in the field, though our data do not preclude any sublethal effects that may result from bee exposure to these compounds or possible synergisms when they co-occur in bee colonies.

Acute toxicity of five pesticides to Apis mellifera larvae reared in vitro

BACKGROUND

The reported high loss rates of managed honey bee colonies have been attributed to diverse stressors including pesticides. Honey bee larvae can be exposed to pesticides in contaminated nectar, pollen and wax. Due to the difficulties of rearing larvae in vitro, research focusing on adult bee exposure to pesticides is more common than that on larva exposure to pesticides. Herein, we aimed to assess the acute toxicity of five insecticides to honey bee larvae using an improved in vitro rearing method.

RESULTS

LC₅₀ and LD₅₀ were calculated for larvae at 72 h following a single diet exposure administered when the larvae were 84 ± 12 h old. Solvent control larval mortalities were less than 15% at 72 h. The LC₅₀ values (mg L^-1 ) for each tested pesticide were as follows: amitraz, 494.27; chlorpyrifos, 15.39; coumaphos, 90.01; fluvalinate, 27.69; and imidacloprid, 138.84. The LD₅₀ values in µg per larva were 14.83 (amitraz), 0.46 (chlorpyrifos), 2.70 (coumaphos), 0.83 (fluvalinate) and 4.17 (imidacloprid).

CONCLUSION

The toxicity of the test pesticides to honey bee larvae from most to least toxic was chlorpyrifos > fluvalinate > coumaphos = imidacloprid > amitraz. © 2017 Society of Chemical Industry.