Autophagy in protists and their hosts: When, how and why?

Pathogenic protists are a group of organisms responsible for causing a variety of human diseases including malaria, sleeping sickness, Chagas disease, leishmaniasis, and toxoplasmosis, among others. These diseases, which affect more than one billion people globally, mainly the poorest populations, are characterized by severe chronic stages and the lack of effective antiparasitic treatment. Parasitic protists display complex life-cycles and go through different cellular transformations in order to adapt to the different hosts they live in. Autophagy, a highly conserved cellular degradation process, has emerged as a key mechanism required for these differentiation processes, as well as other functions that are crucial to parasite fitness. In contrast to yeasts and mammals, protist autophagy is characterized by a modest number of conserved autophagy-related proteins (ATGs) that, even though, can drive the autophagosome formation and degradation. In addition, during their intracellular cycle, the interaction of these pathogens with the host autophagy system plays a crucial role resulting in a beneficial or harmful effect that is important for the outcome of the infection. In this review, we summarize the current state of knowledge on autophagy and other related mechanisms in pathogenic protists and their hosts. We sought to emphasize when, how, and why this process takes place, and the effects it may have on the parasitic cycle. A better understanding of the significance of autophagy for the protist life-cycle will potentially be helpful to design novel anti-parasitic strategies.

Perfect diffractive circular metagrating for Bessel beam transformation

Bessel beams, with their non-diffractive property, have attracted great interest in recent years. Optical needle shaping of Bessel beams is highly desired in many applications, however, this typically requires low numerical aperture (NA) bulky 4f confocal systems incorporated with spatial light modulators or round filters. Here, we employ a circular dielectric metagrating for perfect Bessel beam transformation at a desired wavelength. The dielectric metagrating exhibits a high transmissive diffraction efficiency (up to 75%) for a broadband (460 nm to 560 nm), wide-angle range, and dual-polarization response, which is capable of a high-performance transformation of Bessel beams with arbitrary NAs. Our results show potential for special-beam-required applications such as light storage, imaging, and optical manipulation.

Genomics and morphometrics reveal the adaptive evolution of pikas

Pikas (Lagomorpha: Ochotonidae) are small mouse-like lagomorphs. To investigate their adaptation to different ecological environments during their dispersal from the Qinghai-Xizang (Tibet) Plateau (QTP), we collected 226 pikas and measured 20 morphological characteristics and recorded habitat information. We also sequenced the genome of 81 specimens, representing 27 putative pika species. The genome-wide tree based on 4 090 coding genes identified five subgenera, i.e., Alienauroa, Conothoa, Lagotona, Ochotona, and Pika, consistent with morphometric data. Morphologically, Alienauroa and Ochotona had similar traits, including smaller size and earlier divergence time compared to other pikas. Consistently, the habitats of Alienauroa and Ochotona differed from those of the remaining subgenera. Phylogenetic signal analysis detected 83 genes significantly related to morphological characteristics, including several visual and hearing-related genes. Analysis of shared amino acid substitutions and positively selected genes (PSGs) in Alienauroa and Ochotona identified two genes, i.e., mitochondrial function-related TSFM (p.Q155E) and low-light visual sensitivity-related PROM1 (p.H419Y). Functional experiments demonstrated that TSFM-155E significantly enhanced mitochondrial function compared to TSFM-155Q in other pikas, and PROM1-419Y decreased the modeling of dynamic intracellular chloride efflux upon calcium uptake. Alienauroa and Ochotona individuals mostly inhabit different environments (e.g., subtropical forests) than other pikas, suggesting that a shift from the larger ancestral type and changes in sensory acuity and energy enhancement may have been required in their new environments. This study increases our understanding of the evolutionary history of pikas.

[Epidemiological characteristics of novel coronavirus pneumonia in Shijiazhuang, China]

Objective: To analyze the epidemiological characteristics of an outbreak of novel coronavirus pneumonia (COVID-19) in Shijiazhuang, Hebei Province in 2021 and to provide scientific basis for developing improved strategies to prevent and control the outbreak of COVID-19. Methods: Descriptive analysis of the outbreak of COVID-19 in Shijiazhuang, Hebei Province was performed with SPSS 21.0 and Excel software. The statistical analysis of the incubation period was performed using the rstan package in R4.0.4. Results: As of February 14^th 2021, a total of 942 local confirmed cases were reported in Hebei Province, 869 cases in Shijiazhuang, of which 847 cases were available for case information. This outbreak was mainly in rural areas, with the largest number of confirmed cases in Xiaoguozhuang village, 249 (29.4%); followed by Nanqiaozhai village, 128 (15.1%); and Liujiazuo village, 85 (10.0%). The outbreak lasted from January 2^nd, 2021 to February 14^th, 2021, and was mainly transmitted among the farmers as well as the students through dining parties, public gatherings and family contacts, showing an obvious time and occupation concentration trend. An analysis of 116 local confirmed cases in this outbreak with specific exposure time and onset time indicated that the median incubation period was 6 [interquartile range(IQR): 3.3, 10.0] days; whereas another report including 264 local confirmed cases with specific exposure time window showed that a median incubation period was 8.5 [95% confidence interval (CI): 1.8-18.8] days. Conclusions: This outbreak was mainly related to rural areas, and was associated with parties, public gatherings and family gatherings. Self-protection and isolation of key areas and populations at risk should be effectively implemented to avoid close contact and other measures to reduce the occurrence of COVID-19 aggregation. Based on the results of the incubation period of this outbreak, the isolation period could be recommended to be extended to three weeks.

[Advances in the application of three-dimensional photothermal functionalized scaffold for bone repairation after maxillofacial tumor surgery]

The traditional treatment of maxillofacial tumors includes surgery and chemoradiotherapy. Surgery carries a high risk,and large bone defects are difficult to repair themselves. Besides, chemoradiotherapy can bring serious side effects. Therefore, how to repair the bone defects after maxillofacial tumor surgery and prevent tumor recurrence has become a major clinical challenge. In recent years, photothermal therapy has attracted much attention because of its low invasion, high efficiency, and no side effects. More and more photothermal materials have emerged and been applied in photothermal therapy. In order to treat tumor-related bone defects, many studies use three-dimensional printing technology to prepare photothermal functionalized scaffold to repair bone defects and prevent the recurrence of tumors. Based on photothermal therapy, the review states the photothermal materials, bone repair materials and photothermal functionalized scaffolds in the treatment of maxillofacial tumors at home and abroad, and provides a new way to solve the clinical challenge of bone defect and tumor recurrence after maxillofacial tumor surgery.

[Clinical characteristics and death risk factors of severe COVID-19]

Objective: To analyze the clinical features and death-related risk factors of COVID-19. Methods: We enrolled 891 COVID-19 patients admitted to the Affiliated Hospital of Jianghan University from December 2019 to February 2020, including 427 men and 464 women. Of the 891 cases, 582 were severe or critical, including 423(73%)severe and 159 (27%) critical cases. We compared the demographics, laboratory findings, clinical characteristics, treatments and prognosis data of the 582 severe patients. Univariate and multivariate logistic regression analysis was conducted to explore the risk factors associated with death in COVID-19 patients. Results: The 582 severe patients included 293 males and 289 females, with a median age of 64(range 24 to 106). Sixty-three patients died, including 45 males and 18 females, with a median age of 71(range 37 to 90). The average onset time of the 582 patients was 8 days, of whom 461 (79%) had fever, 358 (62%) dry cough, 274 (47%) fatigue. There were 206 cases with shortness of breath (35%), 155 cases with expectoration (27%), 83 cases with muscle pain or joint pain (14%), 71 cases with diarrhea (12%), and 29 cases with headache (4%). Underlying diseases were present in 267 (46%) patients, most commonly hypertension (194, 33%), followed by diabetes (69, 12%), coronary atherosclerotic heart disease (37, 6%), tumor (18, 3%), and chronic obstructive pulmonary disease (5, 1%). Chest CT showed bilateral lung involvement in 505 patients (87%). Upon admission, the median lymphocyte count of the 582 patients was 0.8(IQR, 0.6-1.1)×10(9)/L, the median D-dimer was 0.5 (IQR, 0.4- 0.8) mg/L, the median N-terminal brain natriuretic peptide precursor (NT-proBNP) was 433 (IQR, 141- 806) pg/L, and the median creatinine was 70.3 (IQR, 56.9-87.9) μmol/L. The death group had a median lymphocyte count of 0.5 (0.4-0.8)×10(9)/L, D-dimer 1.1 (0.7-10.0)mg/L, N-terminal brain natriuretic peptide precursor 1479(893-5 087) pg/ml, and creatinine 89.9(67.1-125.3) μmol/L. Multivariate logistic analysis showed that increased D-dimer (OR: 1.095, 95% CI: 1.045-1.148, P<0.001), increased NT-proBNP (OR: 4.759, 95% CI: 2.437-9.291, P<0.001), and decreased lymphocyte count (OR: 0.180, 95% CI: 0.059-0.550, P=0.003) were the risk factors of death in COVID-19 patients. Conclusions: The average onset time of severe COVID-19 was 8 days, and the most common symptoms were fever, dry cough and fatigue. Comorbidities such as hypertension were common and mostly accompanied by impaired organ functions on admission. Higher D-dimer, higher NT-proBNP, and lower lymphocyte count were the independent risk factors of death in COVID-19 patients.

The complete mitochondrial genome of Carpodacus pulcherrimus (Passeriformes: Fringillidae)

The Himalayan Beautiful Rosefinch Carpodacus pulcherrimus, belongs to the family Fringillidae, distributed in central Himalayas from India (Himachal Pradesh) to southwest China and Bhutan. The conservation status of this species is least concern (LC) in IUCN. In this study, the complete mitogenome of C. pulcherrimus was determined. The mitogenome is a circular molecule of 16,797 bp in length, containing 13 protein-coding genes, 2 ribosome RNA genes, 22 transfer RNA genes, and 1 non-coding region. We reconstructed a phylogenetic tree based on Bayesian inference for other 14 Fringillidae species. The new mitogenome data would provide useful information for application in conservation genetics and further clarify phylogenetic evolution of this species.

Interactions of Mutiple Biological Fields in Stored Grain Ecosystems

Biological entities such as fungi in stored grain evolve and interact with the environment in similar fashions as physical fields. An experiment was conducted to study the behavior of the biological field of fungi in stored grain, as well as the interactions between the biological field of fungi and the physical fields of temperature and moisture. A framework of the biological field is presented to describe biological systems in which multiple biological entities co-exist and interact among themselves and with the surrounding environment. The proposed biological field describes the spatio-temporal distribution of a biological entity and its ability of influencing (or being influenced by) the surrounding biotic and abiotic entities through exchange of energy, matter, and/or information. The strength of a biological field of fungi was quantified as the rate of energy conversion by fungi from grain starch to heat. The experimental data showed that the strength of biological field of fungi in stored grain varied in both space and time, with the maximum field strength of 120-133 W m-3 occurred at the location where the biological field of fungi interacted strongly with the temperature and moisture fields.

[Preliminary study of the relationship between novel coronavirus pneumonia and liver function damage: a multicenter study]

Objective: To analyze the clinical characteristics of cases of novel coronavirus pneumonia and a preliminary study to explore the relationship between different clinical classification and liver damage. Methods: Consecutively confirmed novel coronavirus infection cases admitted to seven designated hospitals during January 23, 2020 to February 8, 2020 were included. Clinical classification (mild, moderate, severe, and critical) was carried out according to the diagnosis and treatment program of novel coronavirus pneumonia (Trial Fifth Edition) issued by the National Health Commission. The research data were analyzed using SPSS19.0 statistical software. Quantitative data were expressed as median (interquartile range), and qualitative data were expressed as frequency and rate. Results: 32 confirmed cases that met the inclusion criteria were included. 28 cases were of mild or moderate type (87.50%), and four cases (12.50%) of severe or critical type. Four cases (12.5%) were combined with one underlying disease (bronchial asthma, coronary heart disease, malignant tumor, chronic kidney disease), and one case (3.13%) was simultaneously combined with high blood pressure and malignant tumor. The results of laboratory examination showed that the alanine aminotransferase (ALT), aspartate aminotransferase (AST), albumin (ALB), and total bilirubin (TBil) for entire cohort were 26.98 (16.88 ~ 46.09) U/L and 24.75 (18.71 ~ 31.79) U/L, 39.00 (36.20 ~ 44.20) g/L and 16.40 (11.34 ~ 21.15) μmol/L, respectively. ALT, AST, ALB and TBil of the mild or moderate subgroups were 22.75 (16.31 ~ 37.25) U/L, 23.63 (18.71 ~ 26.50) U/L, 39.70 (36.50 ~ 46.10) g/L, and 15.95 (11.34 ~ 20.83) μmol/L, respectively. ALT, AST, ALB and TBil of the severe or critical subgroups were 60.25 (40.88 ~ 68.90) U/L, 37.00 (20.88 ~ 64.45) U/L, 35.75 (28.68 ~ 42.00) g/L, and 20.50 (11.28 ~ 25.00) μmol/L, respectively. Conclusion: The results of this multicenter retrospective study suggests that novel coronavirus pneumonia combined with liver damage is more likely to be caused by adverse drug reactions and systemic inflammation in severe patients receiving medical treatment. Therefore, liver function monitoring and evaluation should be strengthened during the treatment of such patients.

Vacuolar ATPase depletion contributes to dysregulation of endocytosis in bloodstream forms of Trypanosoma brucei

Background

Vacuolar H⁺-ATPase (V-ATPase) is a highly conserved protein complex which hydrolyzes ATP and pumps protons to acidify vacuolar vesicles. Beyond its role in pH maintenance, the involvement of V-ATPase in endocytosis is well documented in mammals and plants but is less clear in Trypanosoma brucei.

Methods

In this study, the subcellular localization of V-ATPase subunit B (TbVAB) of T. brucei was assessed via in situ N-terminal YFP-tagging and immunofluorescence assays. Transgenic bloodstream forms (BSF) of T. brucei were generated which comprised either a V-ATPase subunit B (TbVAB) conditional knockout or a V-ATPase subunit A (TbVAA) knockdown. Acridine orange and BCECF-AM were employed to assess the roles of V-ATPase in the pH regulation of BSF T. brucei. The endocytic activities of three markers were also characterized by flow cytometry analyses. Furthermore, trypanosomes were counted from trypanolysis treatment groups (either containing 1% or 5% NHS) and endocytosed trypanosome lytic factor (TLF) was also analyzed by an immunoblotting assay.

Results

TbVAB was found to localize to acidocalcisomes, lysosomes and probably also to endosomes of BSF of T. brucei and was demonstrated to be essential for cell growth. TbVAB depletion neutralized acidic organelles at 24 hours post-tetracycline depletion (hpd), meanwhile the steady state intracellular pH increased from 7.016 ± 0.013 to 7.422 ± 0.058. Trypanosomes with TbVAB depletion at 24 hpd were found to take up more transferrin (2.068 ± 0.277 fold) but less tomato lectin (49.31 ± 22.57%) by endocytosis, while no significant change was detected in dextran uptake. Similar endocytic dysregulated phenotypes were also observed in TbVAA knockdown cells. In addition, TbVAB depleted trypanosomes showed a low uptake of TLF and exhibited less sensitive to lysis in both 1% and 5% NHS treatments.

Conclusions

TbVAB is a key component of V-ATPase and was found to play a key function in endocytosis as well as exhibiting different effects in a receptor/cargo dependent manner in BSF of T. brucei. Besides vacuolar alkalinization, the dysregulation of endocytosis in TbVAB depleted T. brucei is considered to contribute to the reduced sensitivity to lysis by normal human serum.

[Clinical characteristics of 30 medical workers infected with new coronavirus pneumonia]

Objective: To investigate the clinical characteristics of medical staff with novel coronavirus pneumonia(NCP). Methods: 30 patients infected with novel coronavirus referred to jianghan university hospital between January 11, 2020 and January 3, 2020 were studied. The data reviewed included those of clinical manifestations, laboratory investigation and Radiographic features. Results: The patients consisted of 10 men and 20 women, including 22 doctors and 8 nurses,aged 21~59 years(mean 35±8 years).They were divided to 26 common type and 4 severe cases, all of whom had close(within 1m) contact with patients infected of novel coronavirus pneumonia. The average contact times were 12 (7,16) and the average cumulative contact time was 2 (1.5,2.7) h.Clinical symptoms of these patients were fever in 23 patients (76.67%) , headache in 16 petients (53.33%) , fatigue or myalgia in 21patients (70%) , nausea, vomiting or diarrhea in 9 petients (30%) , cough in 25 petients (83.33%) , and dyspnea in 14 petients (46.67%) .Routine blood test revealed WBC<4.0×10(9)/L in 8 petients (26.67%) , (4-10) ×10(9)/L in 22 petients (73.33%) , and WBC>4.0×10(9)/L in 4 petients (13.33%) during the disease.Lymphocyte count<1.0×10(9)/L occurred in 12 petients (40%),abnormal liver function in 7 petients (23.33%) ,myocardial damage in 5 petients(16.67%), elevated D-dimer (>0.5mg/l) in 5 patients (16.67%). Compared with normal patients, the average exposure times, cumulative exposure time, BMI, Fever time, white blood cell count, liver enzyme, LDH, myoenzyme and D-dimer were significantly increased in severe patients, while the lymphocyte count and albumin levels in peripheral blood were significantly decreased.Chest CT mainly showed patchy shadows and interstitial changes.According to imaging examination, 11 patients (36.67%) showed Unilateral pneumonia and 19 patients (63.33%) showed bilateral pneumonia,4 patients (13.33%) showed bilateral multiple mottling and ground-glass opacity.Compared with the patients infected in the protected period, the proportion of severe infection and bilateral pneumonia were both increased in the patients infected in unprotected period. Conclusion: Medical staffs are at higher risk of infection.Infection rates are associated with contact time, the amount of suction virus. Severe patients had BMI increased, heating time prolonged, white blood cell count, lymphocyte count, D-dimer and albumin level significantly changed and were prone to be complicated with liver damage and myocardial damage.Strict protection measures is important to prevent infection for medical workers.

[Clinical characteristics of 30 medical workers infected with new coronavirus pneumonia]

Objective: To investigate the clinical characteristics of medical staff with novel coronavirus pneumonia(NCP). Methods: 30 patients infected with novel coronavirus referred to jianghan university hospital between January 11, 2020 and January 3, 2020 were studied. The data reviewed included those of clinical manifestations, laboratory investigation and Radiographic features. Results: The patients consisted of 10 men and 20 women, including 22 doctors and 8 nurses,aged 21~59 years(mean 35±8 years).They were divided to 26 common type and 4 severe cases, all of whom had close(within 1m) contact with patients infected of novel coronavirus pneumonia. The average contact times were 12 (7,16) and the average cumulative contact time was 2 (1.5,2.7) h.Clinical symptoms of these patients were fever in 23 patients (76.67%) , headache in 16 petients (53.33%) , fatigue or myalgia in 21patients (70%) , nausea, vomiting or diarrhea in 9 petients (30%) , cough in 25 petients (83.33%) , and dyspnea in 14 petients (46.67%) .Routine blood test revealed WBC <4.0×10(9)/L in 8 petients (26.67%) , (4-10) ×10(9)/L in 22 petients (73.33%) , and WBC>4.0×10(9)/L in 4 petients (13.33%) during the disease.Lymphocyte count <1.0×10(9)/L occurred in 12 petients (40%),abnormal liver function in 7 petients (23.33%) ,myocardial damage in 5 petients(16.67%), elevated D-dimer (>0.5mg/l) in 5 patients (16.67%). Compared with normal patients, the average exposure times, cumulative exposure time, BMI, Fever time, white blood cell count, liver enzyme, LDH, myoenzyme and D-dimer were significantly increased in severe patients, while the lymphocyte count and albumin levels in peripheral blood were significantly decreased.Chest CT mainly showed patchy shadows and interstitial changes.According to imaging examination, 11 patients (36.67%) showed Unilateral pneumonia and 19 patients (63.33%) showed bilateral pneumonia,4 patients (13.33%) showed bilateral multiple mottling and ground-glass opacity.Compared with the patients infected in the protected period, the proportion of severe infection and bilateral pneumonia were both increased in the patients infected in unprotected period. Conclusion: Medical staffs are at higher risk of infection.Infection rates are associated with contact time, the amount of suction virus. Severe patients had BMI increased, heating time prolonged , white blood cell count, lymphocyte count, D-dimer and albumin level significantly changed and were prone to be complicated with liver damage and myocardial damage.Strict protection measures is important to prevent infection for medical workers.

[Efficacy of double-incision extracapsular cataract extraction in the treatment of hard-nucleus cataract with low corneal endothelial cell density]

Objective: To discuss the efficacy and security of double-incision extracapsular cataract extraction (ECCE) in the treatment of hard-nucleus cataract with low corneal endothelial cell density. Methods: This was a retrospective case series study. Forty-six patients (47 eyes) with hard-nucleus cataract and low corneal endothelial cell density were enrolled at Shandong Eye Hospital from June 2009 to December 2018, including 22 males and 24 females, aged 50 to 74 (63.8±6.3) years. Preoperative corneal endothelial cell density was less than 1 000 cells/mm(2), and the cataract nuclear hardness was equal to or greater than grade IV. According to the surgical methods, the patients were divided into the single-incision ECCE group (24 eyes) and the double-incision ECCE group (23 eyes). The surgical procedures for the double-incision group were as follows. First, a superior scleral pre-incision was made. Then the conventional capsulorhexis was conducted through a 2.6 mm transparent corneal tunnel incision at the temporal or the nasal side, after which the hydro-dissection was performed. Next, the surgeon cut the pre-incision at the sclera, delivered the lens nucleus, sutured the scleral incision and removed the residual cortical materials from the corneal incision. Finally, a foldable intraocular lens was implanted, and the viscoelastic substance was removed. The intraoperative anterior chamber condition and the postoperative corneal edema condition were monitored. During the 6 month follow-up after surgeries, the endothelium cell density, visual acuity and astigmatism in the two groups were compared. The χ(2) test was used to compare the counting data, and the t test was used to compare the measurement data. Results: There was no statistically significant difference (t=1.12, P=0.28) in the preoperative corneal endothelial cell density between the double-incision and single-incision ECCE groups, which was (827±164) cells/mm(2) and (802±121) cells/mm(2), respectively. At 6 months after operation, in the double-incision and single-incision groups, the endothelial cell density was (793±147) cells/mm(2) and (706±101) cells/mm(2), respectively, and the difference was statistically significant (t=4.37, P<0.01). The percentage of corneal endothelial cell loss was 4.16%±3.12% and 11.69%±2.96%, respectively, and the difference was also statistically significant (t=9.52, P<0.01). The hexagon loss rate of corneal endothelial cells was 9.67%±6.11% and 28.33%±8.39%, respectively, and the difference was statistically significant (t=5.52, P<0.05). In the follow-up of 6 months, none of the eyes in the double-incision ECCE group suffered corneal endothelial decompensation compared with 3 eyes in the single-incision ECCE group. There were no statistically significant differences in postoperative astigmatism and surgically induced astigmatism between the two groups (t=-0.71, 0.15; P>0.05). Conclusions: The double-incision ECCE, in which the lens nucleus is delivered through a scleral incision and other procedures are conducted through a corneal tunnel incision, is safe and effective for cataract patients with hard nucleus and low corneal endothelial cell density. (Chin J Ophthalmol, 2020, 56: 126-130).

The complete mitochondrial genome of Semnopithecus schistaceus

Semnopithecus schistaceus Hodgson, 1840 belongs to subfamily Colobinae, family Cercopithecidae. This species was once mixed with S. entellus. The conservation status of this species is Least Concern (LC) in IUCN. In China, this species has been considered as Critically Endangered (CR) by the Red List of China’s vertebrates. In this study, the complete mitogenome of S. schistaceus was determined. The mitogenome is a circular molecule of 16,534 bp in length, containing 13 protein－coding genes, 2 ribosome RNA genes, 1 light strand replication origin (OL), 22 transfer RNA genes, and 1 non－coding region. We reconstructed a phylogenetic tree based on Bayesian inference for 19 primates species. The Cyt b p-distance is 0.029 between S. schistaceu and S. entellus. Thus, the taxonomic status of these two species remains to be further studied.

Successful Genetic Transfection of the Colonic Protistan Parasite Blastocystis for Reliable Expression of Ectopic Genes

The microbial parasite Blastocystis colonizes the large intestines of numerous animal species and increasing evidence has linked Blastocystis infection to enteric diseases with signs and symptoms including abdominal pain, constipation, diarrhea, nausea, vomiting, and flatulence. It has also recently been reported to be an important member of the host intestinal microbiota. Despite significant advances in our understanding of Blastocystis cell biology and host-parasite interactions, a genetic modification tool is absent. In this study, we successfully established a robust gene delivery protocol for Blastocystis subtype 7 (ST7) and ectopic protein expression was further tested using a high sensitivity nano-luciferase (Nluc) reporter system, with promoter regions from several genes. Among them, a strong promoter encompassing a region upstream of the legumain 5' UTR was identified. Using this promoter combined with the legumain 3' UTR, which contains a conserved, precise polyadenylation signal, a robust transient transfection technique was established for the first time in Blastocystis. This system was validated by ectopic expression of proteins harbouring specific localization signals. The establishment of a robust, reproducible gene modification system for Blastocystis is a significant advance for Blastocystis research both in vitro and in vivo. This technique will spearhead further research to understand the parasite's biology, its role in health and disease, along with novel ways to combat the parasite.

How many species of Apodemus and Rattus occur in China? A survey based on mitochondrial cyt b and morphological analyses

Apodemus (mice) and Rattus (rats) are the top rodent reservoirs for zoonoses in China, yet little is known about their diversity. We reexamined the alpha diversity of these two genera based on a new collection of specimens from China and their cyt b sequences in GenBank. We also tested whether species could be identified using external and craniodental measurements exclusively. Measurements from 147 specimens of Apodemus and 236 specimens of Rattus were used for morphological comparisons. We analysed 74 cyt b sequences of Apodemus and 100 cyt b sequences of Rattus to facilitate phylogenetic estimations. Results demonstrated that nine species of Apodemus and seven species of Rattus, plus a new subspecies of Rattus nitidus, are distributed in China. Principal component analysis using external and craniodental measurements revealed that measurements alone could not separate the recognized species. The occurrence of Rattus pyctoris in China remains uncertain.

An efficient cumate-inducible system for procyclic and bloodstream form Trypanosoma brucei

In Trypanosoma brucei, the tetracycline-inducible system enables tightly-regulated, highly-efficient expression of recombinant proteins or double-stranded RNA in both procyclic and bloodstream form cells, providing useful molecular genetic tools to study gene functions. An alternative, vanillic acid-inducible system is recently described for procyclic T. brucei, providing ∼18-fold increase in GFP reporter expression upon induction (Sunter JD. Mol. Biochem. Parasitol. 2016, 207:45-48). Here we describe a cumate-inducible system that allows efficient, tunable gene expression showing >300-fold increase in GFP expression upon induction. The cumate-inducible system can be used alone or together with the tetracycline-inducible system, in both procyclic and bloodstream form T. brucei. Efficient cumate-inducible expression is also achieved in T. brucei-infected mice.

BAPTA-AM decreases cellular pH, inhibits acidocalcisome acidification and autophagy in amino acid-starved T. brucei

To investigate the role of Ca²⁺ signaling in starvation-induced autophagy in Trypanosoma brucei, the causative agent of human African trypanosomiasis, we used cell-permeant Ca²⁺ chelator BAPTA-AM and cell impermeant chelator EGTA, and examined the potential involvement of several intracellular Ca²⁺ signaling pathways in T. brucei autophagy. The results showed an unexpected effect of BAPTA-AM in decreasing cellular pH and inhibiting acidocalcisome acidification in starved cells. The implication of these results in the role of Ca²⁺ signaling and cellular/organellar pH in T. brucei autophagy is discussed.

ATP-driven and AMPK-independent autophagy in an early branching eukaryotic parasite

Autophagy is a catabolic cellular process required to maintain protein synthesis, energy production and other essential activities in starved cells. While the exact nutrient sensor(s) is yet to be identified, deprivation of amino acids, glucose, growth factor and other nutrients can serve as metabolic stimuli to initiate autophagy in higher eukaryotes. In the early-branching unicellular parasite Trypanosoma brucei, which can proliferate as procyclic form (PCF) in the tsetse fly or as bloodstream form (BSF) in animal hosts, autophagy is robustly triggered by amino acid deficiency but not by glucose depletion. Taking advantage of the clearly defined adenosine triphosphate (ATP) production pathways in T. brucei, we have shown that autophagic activity depends on the levels of cellular ATP production, using either glucose or proline as a carbon source. While autophagosome formation positively correlates with cellular ATP levels; perturbation of ATP production by removing carbon sources or genetic silencing of enzymes involved in ATP generation pathways, also inhibited autophagy. This obligate energy dependence and the lack of glucose starvation-induced autophagy in T. brucei may reflect an adaptation to its specialized, parasitic life style.

Association between Toll-like receptor 9 gene polymorphisms and risk of bacterial meningitis in a Chinese population

We determined whether two common single nucleotide polymorphisms (SNPs) in the Toll-like receptor 9 gene (TLR9) (TLR9+2848 rs352140 and TLR9-1237 rs5743836) influenced susceptibility to bacterial meningitis in a Chinese population. The study comprised 126 patients with bacterial meningitis and 252 control subjects, all of whom were recruited from the Tuberculosis Hospital of Shanxi Province. Genotyping of TLR9+2848 rs352140 and TLR9-1237 rs5743836 was performed by polymerase chain reaction coupled with restriction fragment length polymorphism. Using logistic regression analysis, we found that individuals with the AA genotype were associated with an increased risk of bacterial meningitis compared with those with the GG genotype (OR = 0.43, 95%CI = 0.19-0.95; P = 0.03). In a recessive model, the AA genotype was correlated with an elevated risk of bacterial meningitis compared with the GG+GA genotype (OR = 0.49, 95%CI = 0.22-0.99; P = 0.04). However, no significant differences were observed in the association between the TLR9-1237 rs5743836 polymorphism and the risk of bacterial meningitis in the codominant, dominant, or recessive models. In conclusion, the results of our study suggest an association between the TLR9+2848 polymorphism and a reduced risk of bacterial meningitis in the codominant and recessive models.

Acidocalcisome is required for autophagy in Trypanosoma brucei

Lysosomes play important roles in autophagy, not only in autophagosome degradation, but also in autophagy initiation. In Trypanosoma brucei, an early divergent protozoan parasite, we discovered a previously unappreciated function of the acidocalcisome, a lysosome-related organelle characterized by acidic pH and large content of Ca(2+) and polyphosphates, in autophagy regulation. Starvation- and chemical-induced autophagy is accompanied with acidocalcisome acidification, and blocking the acidification completely inhibits autophagosome formation. Blocking acidocalcisome biogenesis by depleting the adaptor protein-3 complex, which does not affect lysosome biogenesis or function, also inhibits autophagy. Overall, our results support the role of the acidocalcisome, a conserved organelle from bacteria to human, as a relevant regulator in autophagy.

Genomic cloning, expression, and single nucleotide polymorphism association analysis of the insulin-like androgenic gland hormone gene in the oriental river prawn (Macrobrachium nipponense)

Increasing evidence suggests that the insulin-like androgenic gland hormone (IAG) gene plays an important role in male sexual differentiation, metabolism, and growth in crustaceans. In the present study, we isolated the full-length genome sequence of IAG by genome walking based on the cDNA sequence in Macrobrachium nipponense. Four novel single nucleotide polymorphisms (SNPs) were studied, including 509G>T, 529G>T, 590A>T in intron 1, and 2226A>G in intron 2. The association of genetic variation with growth traits [body length (BL) and body weight (BW)] was analyzed. Individuals with GG geno- type at locus 2226A>G maintained higher mean BL (P < 0.01) and BW (P < 0.05) than AA and GA individuals. These results suggest that IAG SNPs may be useful molecular markers for selecting growth traits in M. nipponense.

COI barcode based species-specific primers for identification of five species of stored-product pests from genus Cryptolestes (Coleoptera: Laemophloeidae)

Flat grain beetles of the genus Cryptolestes (Coleoptera: Laemophloeidae) are one of the economically most important stored-product pests which feed on many kinds of agricultural products, especially grains. Nine of more than 40 described Cryptolestes species are recognized as stored-product pests and two of the pest species have a cosmopolitan distribution. Given the rapid growth in global trade of food products, ecological barriers to the spread of pests are easily overcome. Therefore, development of reliable systems for routine quarantine inspection and early infestation detection is vital. In the present study, we established a new rapid and accurate cytochrome c oxidase subunit I-based system for molecular identification of five common stored-product Cryptolestes species, namely, Cryptolestes capensis, Cryptolestes ferrugineus, Cryptolestes pusilloides, Cryptolestes pusillus and Cryptolestes turcicus. Five species-specific primer pairs for traditional uniplex polymerase chain reaction assay are described and their specificity and sensitivity for the identification process is evaluated using larval samples of 12 different populations from three continents (Asia, Europe and North America).

DNA barcoding of five common stored-product pest species of genus Cryptolestes (Coleoptera: Laemophloeidae)

Several species of the genus Cryptolestes Ganglbauer, 1899 (Coleoptera: Laemophloeidae) are commonly found in stored products. In this study, five species of Cryptolestes, with almost worldwide distribution, were obtained from laboratories in China, Czech Republic and the USA: Cryptolestes ferrugineus (Stephens, 1831), Cryptolestes pusillus (Schönherr, 1817), Cryptolestes turcicus (Grouvelle, 1876), Cryptolestes pusilloides (Steel & Howe, 1952) and Cryptolestes capensis (Waltl, 1834). Molecular identification based on a 658 bp fragment from the mitochondrial DNA cytochrome c oxidase subunit I (COI) was adopted to overcome some problems of morphological identification of Cryptolestes species. The utility of COI sequences as DNA barcodes in discriminating the five Cryptolestes species was evaluated on adults and larvae by analysing Kimura 2-parameter distances, phylogenetic tree and haplotype networks. The results showed that molecular approaches based on DNA barcodes were able to accurately identify these species. This is the first study using DNA barcoding to identify Cryptolestes species and the gathered DNA sequences will complement the biological barcode database.

Emerging roles for the FCRL family members in lymphocyte biology and disease

Members of the extended Fc receptor-like (FCRL) family in humans and mice are preferentially expressed by B cells and possess tyrosine-based immunoregulatory function. Although the majority of these proteins repress B cell receptor-mediated activation, there is an emerging evidence for their bifunctionality and capacity to counter-regulate adaptive and innate signaling pathways. In light of these findings, the recent discovery of ligands for several of these molecules has begun to reveal exciting potential for them in normal lymphocyte biology and is launching a new phase of FCRL investigation. Importantly, these fundamental developments are also setting the stage for defining their altered roles in the pathogenesis of a growing number of immune-mediated diseases. Here we review recent advances in the FCRL field and highlight the significance of these intriguing receptors in normal and perturbed immunobiology.

Development of high-speed and wide-angle visible observation diagnostics on Experimental Advanced Superconducting Tokamak using catadioptric optics

A new wide-angle endoscope for visible light observation on the Experimental Advanced Superconducting Tokamak (EAST) has been recently developed. The head section of the optical system is based on a mirror reflection design that is similar to the International Thermonuclear Experimental Reactor-like wide-angle observation diagnostic on the Joint European Torus. However, the optical system design has been simplified and improved. As a result, the global transmittance of the system is as high as 79.6% in the wavelength range from 380 to 780 nm, and the spatial resolution is <5 mm for the full depth of field (4000 mm). The optical system also has a large relative aperture (1:2.4) and can be applied in high-speed camera diagnostics. As an important diagnostic tool, the optical system has been installed on the HT-7 (Hefei Tokamak-7) for its final experimental campaign, and the experiments confirmed that it can be applied to the investigation of transient processes in plasma, such as ELMy eruptions in H-mode, on EAST.

Co-expression of VpROMT gene from Chinese wild Vitis pseudoreticulata with VpSTS in tobacco plants and its effects on the accumulation of pterostilbene

Plant secondary metabolites, such as stilbenes, have fungicidal potential and have been found in several plant species. Stilbenes in grapevine, such as resveratrol and pterostilbene, have recently attracted much attention, they are not only helping the plant to fight against pathogen attack, but they are also being widely used as ingredients of fungicide, anti-inflammatory drugs, antioxidant, and anti-infective agents. However, resveratrol O-methyltransferase gene, related with the synthesis of pterostilbene from resveratrol, has not been characterized effectively from Chinese wild Vitis pseudoreticulata. In this study, a candidate of resveratrol O-methyltransferase gene designated as VpROMT was isolated from a powdery mildew-resistant Chinese wild V. pseudoreticulata 'Baihe-35-1', and characterization studies were performed. Expression studies showed that VpROMT was predominantly expressed in developing roots yet not found in the leaves, stems, nor tendrils when the plants are not challenged. Results of qRT-PCR showed that VpROMT was rapidly induced by Erysiphe necator in V. pseudoreticulata and by methyl-jasmonate, UV-irradiation in suspension culture cells of Vitis romanetii. The expression level varies in different tissues of grapevine, which MeJA and UV-C treatment significantly upregulated the expression of VpROMT gene while UV-B treatment failed to. Co-expression of VpROMT and grapevine stilbene synthase (VpSTS) gene leads to the accumulation of pterostilbene in leaves of tobacco (Nicotiana tabacum) indicating that VpROMT was able to catalyze the biosynthesis of pterostilbene from resveratrol in over-expression transgenic tobacco plants.

Menhaden oil, but not safflower or soybean oil, aids in restoring the polyunsaturated fatty acid profile in the novel delta-6-desaturase null mouse

Background

Polyunsaturated fatty acids (PUFA) have diverse biological effects, from promoting inflammation to preventing cancer and heart disease. Growing evidence suggests that individual PUFA may have independent effects in health and disease. The individual roles of the two essential PUFA, linoleic acid (LA) and α-linolenic acid (ALA), have been difficult to discern from the actions of their highly unsaturated fatty acid (HUFA) downstream metabolites. This issue has recently been addressed through the development of the Δ-6 desaturase knock out (D6KO) mouse, which lacks the rate limiting Δ-6 desaturase enzyme and therefore cannot metabolize LA or ALA. However, a potential confounder in this model is the production of novel Δ-5 desaturase (D5D) derived fatty acids when D6KO mice are fed diets containing LA and ALA, but void of arachidonic acid.

Objective

The aim of the present study was to characterize how the D6KO model differentially responds to diets containing the essential n-6 and n-3 PUFA, and whether the direct provision of downstream HUFA can rescue the phenotype and prevent the production of D5D fatty acids.

Methodology

Liver and serum phospholipid (PL) fatty acid composition was examined in D6KO and wild type mice fed i) 10% safflower oil diet (SF, LA rich) ii) 10% soy diet (SO, LA+ALA) or iii) 3% menhaden oil +7% SF diet (MD, HUFA rich) for 28 days (n = 3-7/group).

Results

Novel D5D fatty acids were found in liver PL of D6KO fed SF or SO-fed mice, but differed in the type of D5D fatty acid depending on diet. Conversely, MD-fed D6KO mice had a liver PL fatty acid profile similar to wild-type mice.

Conclusions

Through careful consideration of the dietary fatty acid composition, and especially the HUFA content in order to prevent the synthesis of D5D fatty acids, the D6KO model has the potential to elucidate the independent biological and health effects of the parent n-6 and n-3 fatty acids, LA and ALA.

PCR approach for the detection of Trypanosoma brucei and T. equiperdum and their differentiation from T. evansi based on maxicircle kinetoplast DNA

The goal of this study was to develop a PCR approach based on the sequence of maxicircle kinetoplast DNA (kDNA) of Trypanosoma brucei to distinguish T. brucei/T. equiperdum from T. evansi and to evaluate its diagnostic use for their detection in blood samples. Primers derived from the sequence of the maxicircle kDNA of T. brucei, encoding the NADH dehydrogenase subunit 5 (nad5) gene, were used to test the PCR-amplification from T. brucei (including T. b. brucei and T. b. rhodesiense), T. equiperdum, T. evansi, T. vivax and T. congolense. A primer pair to a nuclear DNA region incorporated into a separate PCR was employed to control for the presence of amplifiable genomic DNA (representing the subgenus Trypanozoon) in each sample subjected to the PCR. Products of approximately 395bp were amplified from all T. brucei and T. equiperdum samples tested using the nad5-PCR, but not from T. evansi DNA samples or any of the control samples representing T. vivax, T. congolense, or host. The current PCR approach allows the rapid differentiation of T. brucei/T.equiperdum from T. evansi and can detect the equivalent of 20-25 cells of T. brucei or T. equiperdum in purified genomic DNA or infected blood samples.

Application of multiple DNA fingerprinting techniques to study the genetic relationships among three members of the subgenus Trypanozoon (Protozoa: Trypanosomatidae)

Three different DNA fingerprinting techniques, the mobile genetic element (MGE)-PCR, simple sequence repeat (SSR)-PCR and random amplified polymorphic DNA (RAPD)-PCR, were used to define a large set of genetic markers to study genetic similarity within and among Trypanosoma brucei, Trypanosoma equiperdum and Trypanosoma evansi strains (n=18) from China, Africa and South America and to investigate their genetic relationships. Using the three fingerprinting techniques, >890 bands (ranging in size from 0.2 to 2kb) were defined for all 18 strains of Trypanosoma. Within each of the strains, 39-59 bands were defined. The similarity coefficients between strains ranged from approximately 41 to 94%, with a mean of 65%. There was more genetic similarity among strains within T. evansi (mean of approximately 79%) compared with T. equiperdum ( approximately 65%) and T. brucei ( approximately 59%). The similarity coefficient data were used to construct the dendrogram, which revealed that (irrespective of species) the majority of strains from China and South America grouped together to the exclusion of those from Africa. The exceptions were a T. brucei strain from Africa and a T. equiperdum strain of unknown origin. Hence, employing data sets generated using the three different fingerprinting methods, it was not possible to unequivocally distinguish among T. brucei, T. evansi and T. equiperdum, although there was a tendency for T. evansi strains to group together to the exclusion of T. brucei. The findings provide support for the hypothesis that T. evansi originated from a mutated form of T. equiperdum and stimulate further investigations of the genetic make-up and evolution of members of the subgenus Trypanozoon.

Enhancement of hyperthermia-induced apoptosis by a free radical initiator, 2,2'-azobis (2-amidinopropane) dihydrochloride, in human histiocytic lymphoma U937 cells

To elucidate the mechanism how a free radical initiator, 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH), induces cell death at hyperthermic temperatures, apoptosis in a human histiocytic lymphoma cell line, U937, was investigated. Free radical formation deriving from the thermal decomposition of AAPH was examined by spin trapping with 5,5-dimethyl-1-pyrroline-N-oxide (DMPO). An assay for DNA fragmentation, observation of nuclear morphological changes, and flow cytometry for phosphatidylserine (PS) externalization were used to detect apoptosis and revealed enhancement of 44.0 degrees C hyperthermia-induced apoptosis by free radicals due to AAPH. However, free radicals alone derived from AAPH did not induce apoptosis. Hyperthermia induced the production of lipid peroxidation (LPO), an increase in intracellular Ca2+ concentration ([Ca2+]i) and enhanced expression of the type 1 inositol 1,4,5-trisphosphate receptor (IP3R1). The effects of hyperthermia on LPO and [Ca2+]i were enhanced markedly by the combination with AAPH. A significant decrease in Bcl-2 expression, increase in Bax expression, a loss of mitochondrial membrane potential (delta psi m) and a marked increase in cytochrome c expression were found only in cells treated with hyperthermia and AAPH. Although an intracellular Ca2+ ion chelator, BAPTA-AM, completely inhibited DNA fragmentation, water-soluble vitamin E, Trolox, only partially suppressed DNA fragmentation and the increase in [Ca2+]i. In contrast, LPO was inhibited completely by Trolox, but no inhibition by BAPTA-AM was found. These results suggest that apoptosis induced by hyperthermia alone is due to the increase in [Ca2+]i arising from increased expression of IP3R1 and LPO. Additional increase in [Ca2+]i due to increased LPO and the activation of mitochondria-caspase dependent pathway play a major role in the enhancement of apoptosis by the combination with hyperthermia and AAPH.

Apoptosis induced by cadmium in human lymphoma U937 cells through Ca2+-calpain and caspase-mitochondria- dependent pathways

Apoptosis induced by cadmium has been shown in many tissues in vivo and in cultured cells in vitro. However, its molecular mechanism is not fully understood. When the human histiocytic lymphoma cell line U937 was treated with cadmium for 12 h, evidence of apoptotic features, including change in nuclear morphology, DNA fragmentation, formation of DNA ladder in agarose gel electrophoresis, and phosphatidylserine externalization, were obtained. Moreover, loss of the mitochondrial membrane potential (Deltapsi(m)) was observed in the cadmium-treated cells and was inhibited by a broad caspase inhibitor (Z-VAD-FMK). Caspase inhibitors suppressed the DNA fragmentation in the order of Z-VAD-FMK > caspase-8 inhibitor > caspase-3 inhibitor. Expression of Bcl-x(L) and Bid decreased significantly in the cadmium-treated cells, although no apparent change in Bcl-2 and Bax expression was found. Tetrakis-(2-pyridylmethyl) ethylendiamine, a cell-permeable heavy metal chelator, partially reversed the increase of fluorescence of Fura-2 in the cadmium-treated cells. In addition, verapamil (70 microm), a voltage-dependent Ca(2+) channel blocker, inhibited the DNA fragmentation induced by cadmium less than 100 microm and decreased the fluorescence of Fura-2. Cadmium up-regulated the expression of type 1 inositol 1,4,5-trisphosphate receptor (IP(3)R) but not type 2 or type 3 IP(3)R. Calpain inhibitors I and II partially prevented DNA fragmentation. No effects of Z-VAD-FMK on the expression of type 1 IP(3)R or of calpain inhibitors on the loss of Deltapsi(m) were observed. These results suggest that cadmium possibly induced apoptosis in U937 cells through two independent pathways, the Ca(2+)-calpain-dependent pathway and the caspase-mitochondria-dependent pathway.

[Screening on lameness caused by poliomyelitis in Anhui Province]

In 1992, a screening of poliomyelitis caused lameness among children under 15 years of age was conducted to verify whether poliomyelitis has been absent in Anhui. A total number of 7,639 cases were diagnosed as poliomyelitis caused lameness. The prevalence rate was 0.44%, the rate was higher in plains than in hilly and mountainous areas. Rate was higher in ural than in urban areas. The disease mainly occurred in children at age below 3. The result showed that there were two epidemic peaks during 1976-1991, but the incidence rate tended to be declining. The incidence rate was the lowest in 1991. Many cases were not reported during 1976-1988.

Isolation of methylcarbamoyl-adducts of adenine and cytosine following in vitro reaction of methyl isocyanate with calf thymus DNA

Methylisocyanate (MIC) is the direct-acting acylating compound involved in the Bhopal, India disaster which occurred on December 3rd, 1984. The accidental release of MIC resulted in at least 2000 deaths, thousands of injuries and exposure of at least 200,000 people to varying amounts of MIC. We have studied how MIC reacts with 2'-deoxyribonucleosides at pH 7.0 and 37 degrees C for 1 h. MIC acylates exocyclic amino groups resulting in the following methylcarbamoyl (MC) adducts: N6-MC-Ade (0.5% yield) and N4-MC-dCyd (6%). No adducts were detected with dThd and dGuo. UV, NMR and mass spectrometry were employed to spectroscopically characterize these adducts. MIC was reacted with calf thymus DNA (pH 7.0, 37 degrees C, 1 h) and yielded N6-MC-Ade (0.3 nmol/mg DNA) and N4-MC-dCyd (2.0 nmol/mg DNA). The inability of others to observe genetic mutations by MIC in Salmonella and Drosophila is consistent with the exocyclic adducts at N4 of Cyt and N6 of Ade where normal hydrogen bonding can occur after rotation of the methylcarbamoyl group anti to the Watson-Crick side of the molecule assuming that MIC binds to DNA within the intact cell.