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Background: Prompt and precise identification of black flies (Simuliidae) is crucial, given their biting behaviour and significant impact on human and animal health. To address the challenges presented by morphology and chromosomes in black fly taxonomy, along with the limited availability of molecular data pertaining to the black fly fauna in Vietnam, this study employed DNA-based approaches. Specifically, we used mitochondrial and nuclear-encoded genes to distinguish nominal species of black flies in Vietnam., Methods: In this study, 135 mitochondrial cytochrome c oxidase subunit I (COI) sequences were established for 45 species in the genus Simulium in Vietnam, encompassing three subgenera (Gomphostilbia, Nevermannia, and Simulium), with 64 paratypes of 27 species and 16 topotypes of six species. Of these COI sequences, 71, representing 27 species, are reported for the first time., Results: Combined with GenBank sequences of specimens from Malaysia, Myanmar, Thailand, and Vietnam, a total of 234 DNA barcodes of 53 nominal species resulted in a 71% success rate for species identification. Species from the non-monophyletic Simulium asakoae, S. feuerborni, S. multistriatum, S. striatum, S. tuberosum, and S. variegatum species groups were associated with ambiguous or incorrect identifications. Pairwise distances, phylogenetics, and species delimitation analyses revealed a high level of cryptic diversity, with discovery of 15 cryptic taxa. The current study also revealed the limited utility of a fast-evolving nuclear gene, big zinc finger (BZF), in discriminating closely related, morphologically similar nominal species of the S. asakoae species group., Conclusion: This study represents the first comprehensive molecular genetic analysis of the black fly fauna in Vietnam to our knowledge, providing a foundation for future research. DNA barcoding exhibits varying levels of differentiating efficiency across species groups but is valuable in the discovery of cryptic diversity., (© 2023. BioMed Central Ltd., part of Springer Nature.)

Purpose: The objective of this study is to describe a novel method for creating a distal landing zone for thoracic endovascular aortic repair (TEVAR) in chronic aortic dissection. The technique is described in a patient with prior total arch and descending aortic replacement, with false lumen expansion., Technique: A cheese-wire endovascular septotomy was desired to create a single lumen above the celiac axis. To avoid dividing the septum caudally across the visceral segment, we performed a modified septotomy in a cephalad direction. Stiff wires were passed into the prior surgical graft, through true lumen on the right and false lumen on the left. An additional wire was passed across an existing fenestration at the level of the celiac axis, and snared and externalized. 7F Ansel sheaths were advanced and positioned tip-to-tip at the fenestration. Using the stiff wires as tracks, the through-wire was pushed cephalad to endovascularly cut the septum. Angiogram demonstrated successful septotomy, and TEVAR was performed to just above the celiac with successful aneurysm exclusion and no endoleak or retrograde false lumen perfusion. Follow-up computed tomography angiogram (CTA) showed continued exclusion without false lumen perfusion., Conclusions: This novel modification in a reverse direction provides an alternative method for endovascular septotomy, when traditional septotomy may threaten the visceral vessels.

Background: Hereditary cancer syndromes (HCS) are responsible for 5-10% of cancer cases. Genetic testing to identify pathogenic variants associated with cancer predisposition has not been routinely available in Vietnam. Consequently, the prevalence and genetic landscape of HCS remain unknown., Methods: 1165 Vietnamese individuals enrolled in genetic testing at our laboratory in 2020. We performed analysis of germline mutations in 17 high- and moderate- penetrance genes associated with HCS by next generation sequencing., Results: A total of 41 pathogenic variants in 11 genes were detected in 3.2% individuals. The carrier frequency was 4.2% in people with family or personal history of cancer and 2.6% in those without history. The percentage of mutation carriers for hereditary colorectal cancer syndromes was 1.3% and for hereditary breast and ovarian cancer syndrome was 1.6%. BRCA1 and BRCA2 mutations were the most prevalent with the positive rate of 1.3% in the general cohort and 5.1% in breast or ovarian cancer patients. Most of BRCA1 mutations located at the BRCA C-terminus domains and the top recurrent mutation was NM_007294.3:c.5251C>T (p.Arg1751Ter). One novel variant NM_000038.6(APC):c.6665C>A (p.Pro2222His) was found in a breast cancer patient with a strong family history of cancer. A case study of hereditary cancer syndrome was illustrated to highlight the importance of genetic testing., Conclusion: This is the first largest analysis of carrier frequency and mutation spectrum of HCS in Vietnam. The findings demonstrate the clinical significance of multigene panel testing to identify carriers and their at-risk relatives for better cancer surveillance and management strategies., Competing Interests: H-DN, NN, DD, VUT, HHN, ML, YN, HT, M-DP, HG, and LT are current employees of Gene Solutions, Vietnam. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Tran, Nguyen, Pham, Phan, Nguyen, Nguyen, Nguyen, Doan, Le, Nguyen, Jasmine, Nguyen, Nguyen, Nguyen, Do, Tran, Nguyen, Le, Nguyen, Do, Truong, Tang, Phan, Nguyen, Giang and Tu.)

This study was conducted to determine the prevalence and determinants of medication adherence among patients with HIV/AIDS in southern Vietnam., Methods: A cross-sectional study was conducted in a hospital in southern Vietnam from June to December 2019 on patients who began antiretroviral therapy (ART) for at least 6 months. Using a designed questionnaire, patients were considered adherent if they took correct medicines with right doses, on time and properly with food and beverage and had follow-up visits as scheduled. Multivariable logistic regression was used to identify determinants of adherence., Key Findings: A total of 350 patients (from 861 medical records) were eligible for the study. The majority of patients were male (62.9%), and the dominant age group (≥35 years old) accounted for 53.7% of patients. Sexual intercourse was the primary route of transmission of HIV (95.1%). The proportions of participants who took the correct medicine and at a proper dose were 98.3% and 86.3%, respectively. In total, 94.9% of participants took medicine appropriately in combination with food and beverage, and 75.7% of participants were strictly adherent to ART. The factors marital status (odds ratio (OR) = 2.54; 95%CI = 1.51-4.28), being away from home (OR = 1.7; 95%CI = 1.03-2.78), substance abuse (OR = 2.7; 95%CI = 1.44-5.05), general knowledge about ART (OR = 2.75; 95%CI = 1.67-4.53), stopping medication after improvement (OR = 4.16; 95%CI = 2.29-7.56) and self-assessment of therapy adherence (OR = 9.83; 95%CI = 5.44-17.77) were significantly associated with patients' adherence., Conclusions: Three-quarters of patients were adherent to ART. Researchers should consider these determinants of adherence in developing interventions in further studies.

A new black fly species, Simulium yukawai, is described on the basis of one female and its pupal exuviae from Vietnam. This new species is placed in the S. crocinum species-group of Simulium (Simulium) (Diptera: Simuliidae). It is characterized in the female by the paraproct covered with 48-50 distinct hairs on its ventral and lateral surfaces, and in the pupa by the frons and most of the thorax bare, gill with six dark filaments in three pairs closely arising from the base, of which the two outer filaments of the dorsal and middle pairs are much longer than other filaments, abdomen with distinct spine-combs on the dorsal surface of segments 7-9, and cocoon wall-pocket shaped, with a large anterolateral window on each side. Taxonomic notes are given to separate this new species from related species. This species is the fourth member of the S. crocinum species-group known from Vietnam.

Simulium pumatense sp. nov. is described from Vietnam, and is placed in the Simulium feuerborni species-group of the subgenus Simulium (Nevermannia) Enderlein. Its morphological characteristics include the relatively smaller numbers of the following three numerical features: inner teeth of the female mandible (15-18), minute conical processes (16) on the female cibarium, and male upper-eye facets (in 15 vertical columns and 16 horizontal rows). Keys are constructed to distinguish this species from four species of the same group in Vietnam. Our molecular analysis of the DNA barcoding COI gene shows that this species is most closely related to cytoform A of the S. feuerborni complex from Thailand., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: Current guidelines recommend vascular mapping ultrasound (US) prior to arteriovenous fistula creation. Blunted venous waveforms (BVWs) suggest central venous stenosis; however, this relationship and one between BVWs and the presence of a central venous catheter (CVC) remain unclear., Methods: All patients who received upper extremity vascular mapping US between January 2013 and October 2014 at a single institution were retrospectively reviewed. Patient demographics, comorbidities, US results, pacemaker history, and CVC status were collected. Waveforms were assessed at the proximal subclavian vein/distal axillary vein and interpreted by radiologists. Patients were determined to have central venous stenosis (CVS) if detected by venography within 6 months of US., Results: There were 342 patients, of which 165 (48%) had a current CVC and 29 (8.5%) had BVW of at least 1 arm. Right-sided BVW were associated with a history of a prior ipsilateral CVC (odds ratio [OR] = 4.5, 95% confidence interval [CI] = 1.6-12.6, P = 0.009). Of the 342 patients, 69 (20%) had a venogram within 6 months. Seventeen (25%) of the 69 patients had CVS, with 7 involving the left subclavian vein, 8 the right subclavian vein, and 3 the superior vena cava (one patient had tandem stenoses). A BVW on the left side was not associated with any CVS. A BVW on the right side was associated with an ipsilateral CVS (OR = 5.8, 95% CI = 1.2-27.4, P = 0.04). This association persisted in the setting of a prior CVC (relative risk = 1.3, 95% CI = 0.9-2, P = 0.01)., Conclusions: There are associations between right-sided BVW and an ipsilateral subclavian vein stenosis. We recommend that hemodialysis access planning includes venography to rule out central vein stenosis in patients with BVW, especially if right-sided and in the setting of a prior CVC., (Copyright © 2017 Elsevier Inc. All rights reserved.)

The biodiversity of black flies (Diptera: Simuliidae), which are biting insects of medical and veterinary importance, is strikingly high in Southeast Asian countries, such as Indonesia, Malaysia, Philippines and Thailand. In 2013, we began to explore the fauna of black flies in Vietnam, which has so far been poorly studied. In this monograph, the wealth of the biodiversity of black flies in Vietnam is also confirmed on the basis of the results of our recent investigations, though limited to five provinces in the country.      Morphotaxonomic studies of black flies obtained from Sapa, Lao Cai Province, northern Vietnam, in 2014 and Nghe An Province, northern Vietnam, in 2015, and reexaminations of black flies collected from Tam Dao, Vinh Phuc Province, northern Vietnam, in 2013, Thua Thien Hue Province, central Vietnam, in 2014, and Lam Dong Province, southern Vietnam, in 2014, were conducted. A total of 22 species are described as new, including one in the newly recorded subgenus Montisimulium Rubtsov, and three species are recognized as new records from Vietnam. This investigation brings the number of species of black flies known in Vietnam to 70, all of which are assigned to the genus Simulium Latreille, and are placed in four subgenera (25 in Gomphostilbia Enderlein, one in Montisimulium, seven in Nevermannia Enderlein, and 37 in Simulium Latreille s. str.). The numbers of species-groups recognized include seven in Gomphostilbia, three in Nevermannia and nine in Simulium, indicating a high diversity of putative phylogenetic lineages. New species include S. (G.) sanchayense sp. nov. (= the species formerly regarded as S. (G.) brinchangense Takaoka, Sofian-Azirun & Hashim), S. (S.) lowi sp. nov. (= the species formerly regarded as S. (S.) brevipar Takaoka & Davies), S. (S.) fuscicoxae sp. nov. [= the species formerly regarded as S. (S.) rufibasis Brunetti (in part)], S. (S.) suoivangense sp. nov. [= morphoform 'b' of the S. (S.) tani Takaoka & Davies (complex)]. Newly recorded species are S. (G.) parahiyangum Takaoka & Sigit, S. (N.) maeaiense Takaoka & Srisuka, and S. (S.) doipuiense Takaoka & Choochote (complex) [= the species formerly regarded as S. (S.) rufibasis Brunetti (in part)]. The substitute name, S. (S.) huense, is given for the species that was described under the name of S. (S.) cavum from southern Vietnam. A redescription of the female, male, pupa and larva of S. (G.) asakoae Takaoka & Davies is presented, and the female and larva of S. (G.) hongthaii Takaoka, Sofian-Azirun & Ya'cob are described for the first time. Keys to 10 subgenera in the Oriental Region and all 70 species recorded from Vietnam are provided for females, males, pupae and mature larvae.      As investigations extend nationwide in all the provinces in Vietnam, more new species and records are expected to be discovered. It is hoped that this monograph will be useful as a baseline taxonomic reference for future studies of black flies in Vietnam and neighbouring countries.

Objective: The autogenous arteriovenous fistula (AVF) has been shown to be superior to the arteriovenous graft (AVG) with respect to cost, complications, and primary patency. Therefore, the National Kidney Foundation Disease Outcomes Quality Initiative guidelines recommend reserving AVGs for patients who do not have adequate superficial venous anatomy to support AVF placement. The brachial artery-brachial vein arteriovenous fistula (BVAVF) has emerged as an autologous last-effort alternative. However, there are limited data comparing BVAVFs and AVGs in patients who are otherwise not candidates for a traditional AVF., Methods: Patients who received a BVAVF from July 2009 to July 2014 were compared with those who received an AVG during the same period. At our institution, BVAVF and AVG are only performed in patients with poor superficial venous anatomy. Patient demographic data, operative details, and subsequent follow-up were collected. BVAVFs were performed with a two-stage approach, with initial arteriovenous anastomosis, followed by delayed superficialization or transposition. Our primary outcome measure was primary functional assisted patency at 1 year. Patients lost to follow-up were excluded. A subgroup analysis was also performed for patients in whom the BVAVF or the AVG was their first hemodialysis access surgery., Results: During the study period, 29 patients underwent BVAVF and 32 underwent AVG. There were no differences in age, gender, or presence of diabetes between the two groups. The median days to cannulation from the initial operation were 141 (interquartile range, 94-214) in the BVAVF group and 29 (interquartile range, 14-33) in the AVG group (P < .001). Fewer patients required interventions to maintain or re-establish patency in the BVAVF group than in the AVG group (10% v. 44%; P < .01). The 1-year primary patency was greater for BVAVF (62% vs 25%; P < .01); however, there was no difference in the functional assisted primary patency rates at 1 year (45% vs 25%; P = .1). Subgroup analysis demonstrated greater 1-year primary functional assisted primary patency (52% vs 19%; P < .05) in patients without prior access surgery., Conclusions: The BVAVF is a viable alternative to the AVG in patients with inadequate superficial venous anatomy, especially in access-naïve patients. The decision to perform BVAVF must be weighed against the delay in functional maturation expected compared with AVG., (Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Purpose: This paper aims to analyze the household financial burden and poverty impacts of cancer treatment in Vietnam., Methods: Under the "ASEAN CosTs in ONcology" study design, three major specialized cancer hospitals were employed to assemble the Vietnamese data. Factors of socioeconomic, direct, and indirect costs of healthcare were collected prospectively through both individual interviews and hospital financial records., Results: The rates of catastrophic expenditure based on the cut-off points of 20%, 30%, 40%, and 50% of household's income were 82.6%, 73.7%, 64.7%, and 56.9%, respectively. 37.4% of the households with patient were impoverished by the treatment costs for cancer. The statistically significant correlates of the impoverishment problem were higher among older patients (40-60 years: 1.77, 95% CI 1.14-2.73; above 60 years: 1.75, 95% CI 1.03-2.98); poorer patients (less than 100% national income: 29, 95% CI 18.6-45.24; less than 200% national income: 2.89, 95% CI 1.69-4.93); patients who underwent surgery alone (receiving nonsurgery treatment: 2.46, 95% CI 1.32-4.59; receiving multiple treatments: 2.4, 95% CI 1.38-4.17)., Conclusions: Lots of households were pushed into poverty due to their expenditure on cancer care; more actions are urgently needed to improve financial protection to the vulnerable groups.

Background: The benefit of intraoperative cholangiography (IOC) is controversial in patients with gallstone pancreatitis whose bilirubin levels are normalizing. IOC with subsequent endoscopic retrograde cholangiopancreatography may lengthen duration of surgery and length of stay, whereas failure to clear the common bile duct may result in recurrent pancreatitis., Methods: We performed a 6-year retrospective cohort analysis of consecutive adult patients with mild gallstone pancreatitis undergoing same-admission cholecystectomy at 2 university-affiliated medical centers. Institution A routinely performed IOC, whereas institution B did not. The primary outcome was readmission within 30 days for recurrent pancreatitis., Results: Of 520 patients evaluated, 246 (47%) were managed at institution A (routine IOC) and 274 (53%) were managed at institution B (restricted IOC). Patients at institution B had a shorter duration of surgery (1.0 vs 1.6 hours, P < .001), shorter length of stay (4 vs 5 days, P < .001), and fewer postoperative endoscopic retrograde cholangiopancreatographies performed (1.8% vs 21%, P < .001), without a difference in readmissions (1.5% vs 0%, P = .12)., Conclusions: Routine IOC is not necessary in the setting of mild gallstone pancreatitis with normalizing bilirubin values., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Importance: Acute cholangitis (AC), particularly severe AC, has historically required urgent endoscopic decompression, although the timing of decompression is controversial. We previously identified 2 admission risk factors for adverse outcomes in AC: total bilirubin level greater than 10 mg/dL and white blood cell count greater than 20 000 cells/µL., Objectives: To validate previously identified prognostic factors in AC, evaluate the effect of timing of endoscopic retrograde cholangiopancreatography on clinical outcomes, and compare recent experience with AC vs an historical cohort., Design, Setting, and Participants: A retrospective analysis (2008-2015) of patients with AC (validation cohort, n = 196) was conducted at 2 academic medical centers to validate predictors of adverse outcome. Timing of endoscopic retrograde cholangiopancreatography and outcome were stratified by severity using the Tokyo Guidelines for acute cholangitis diagnosis. Outcomes for the validation cohort were compared with the derivation cohort (1995-2005; n = 114). Data analysis was conducted from July 1, 2015, to September 9, 2015., Main Outcomes and Measures: Death and a composite outcome of death or organ failure., Results: The median age of patients in the derivation cohort was 54 years (interquartile range, 40-65 years) and in the validation cohort was 59 years (45-67 years). Multivariate logistic regression analysis of the validation cohort confirmed white blood cell count of more than 20 000 cells/µL (odds ratio, 3.4; 95% CI, 1.2-9.5; P = .02) and total bilirubin level of more than 10 mg/dL (odds ratio, 5.4; 95% CI, 1.8-16.4; P = .003) as independent risk factors for poor outcomes. In the validation cohort, timing of endoscopic retrograde cholangiopancreatography was not significantly different between those with and without an adverse outcome, even when stratified by AC severity (moderate: median, 0.6 hours [interquartile range (IQR), 0.5-0.9] vs 1.7 hours [IQR, 0.7-18.0] and severe: median, 10.6 hours [IQR, 1.2-35.1] vs 25.5 hours [IQR, 15.5-58.5] for those with and without adverse events, respectively). Patients in the validation cohort had a shorter hospital length of stay (median, 7 days [IQR, 4-10 days] vs 9 days [IQR, 5-16 days]) and lower rate of intensive care unit admission (26% vs 82%), despite a higher rate of severe cholangitis (n = 131 [67%] vs n = 29 [25%]). There were no significant differences in the composite outcome between the validation and derivation cohorts (22 [18.6%] vs 44 [22.4%]; P = .47). Adjusted analysis demonstrated decreased mortality in the validation cohort (odds ratio, 0.3; 95% CI, 0.1-0.7; P = .01)., Conclusions and Relevance: White blood cell count greater than 20 000 cells/µL and total bilirubin level greater than 10 mg/dL are independent prognostic factors for adverse outcomes in AC. Consideration should be given to include these criteria in the Tokyo Guidelines severity assessment. Timing of endoscopic retrograde cholangiopancreatography does not appear to affect clinical outcomes in these patients. Management of AC has improved with time, with an overall shorter hospital length of stay, lower rate of intensive care unit admission, and a decreased adjusted mortality, demonstrating improvements in care efficiency and delivery.

Background: The ability to predict whether a child has complicated appendicitis at initial presentation may influence clinical management. However, whether complicated appendicitis is associated with prehospital or inhospital factors is not clear. We also investigate whether hyponatremia may be a novel prehospital factor associated with complicated appendicitis., Materials and Methods: A retrospective review of all pediatric patients (≤12 y) with appendicitis treated with appendectomy from 2000 to 2013 was performed. The main outcome measure was intraoperative confirmation of gangrenous or perforated appendicitis. A multivariable analysis was performed, and the main predictors of interest were age <5 y, symptom duration >24 h, leukocytosis (white blood cell count >12 × 10 3 /mL), hyponatremia (sodium ≤135 mEq/L), and time from admission to appendectomy., Results: Of 392 patients, 179 (46%) had complicated appendicitis at the time of operation. Univariate analysis demonstrated that patients with complicated appendicitis were younger, had a longer duration of symptoms, higher white blood cell count, and lower sodium levels than patients with noncomplicated appendicitis. Multivariable analysis confirmed that symptom duration >24 h (odds ratio [OR] = 5.5, 95% confidence interval [CI] = 3.5-8.9, P < 0.01), hyponatremia (OR = 3.1, 95% CI = 2.0-4.9, P < 0.01), age <5 y (OR = 2.3, 95% CI = 1.3-4.0, P < 0.01), and leukocytosis (OR = 1.9, 95% CI = 1.0-3.5, P = 0.04) were independent predictors of complicated appendicitis. Increased time from admission to appendectomy was not a predictor of complicated appendicitis (OR = 0.8, 95% CI = 0.5-1.2, P = 0.2)., Conclusions: Prehospital factors can predict complicated appendicitis in children with suspected appendicitis. Hyponatremia is a novel marker associated with complicated appendicitis. Delaying appendectomy does not increase the risk of complicated appendicitis once intravenous antibiotics are administered. This information may help guide resource/personnel allocation, timing of appendectomy, and decision for nonoperative management of appendicitis in children., (Copyright © 2016 Elsevier Inc. All rights reserved.)

The increasing attention on Vietnam as a biodiversity hotspot prompted an investigation of the potential for cryptic diversity in black flies, a group well known elsewhere for its high frequency of isomorphic species. We analyzed the banding structure of the larval polytene chromosomes in the Simulium tuberosum species group to probe for diversity beyond the morphological level. Among 272 larvae, 88 different chromosomal rearrangements, primarily paracentric inversions, were discovered in addition to 25 already known in the basic sequences of the group in Asia. Chromosomal diversity in Vietnam far exceeds that known for the group in Thailand, with only about 5% of the rearrangements shared between the two countries. Fifteen cytoforms and nine morphoforms were revealed among six nominal species in Vietnam. Chromosomal evidence, combined with available molecular and morphological evidence, conservatively suggests that at least five of the cytoforms are valid species, two of which require formal names. The total chromosomal rearrangements and species (15) now known from the group in Vietnam far exceed those of any other area of comparable size in the world, supporting the country's status as a biodiversity hotspot. Phylogenetic inference based on uniquely shared, derived chromosomal rearrangements supports the clustering of cytoforms into two primary lineages, the Simulium tani complex and the Southeast Asian Simulium tuberosum subgroup. Some of these taxa could be threatened by habitat destruction, given their restricted geographical distributions and the expanding human population of Vietnam., Competing Interests: The authors have declared that no competing interests exist.

Prior studies have shown racial and gender differences with respect to maturation of arteriovenous fistulas. Women and minorities have lower maturation rates for unclear reasons. Small arterial diameter and high brachial artery bifurcation (HBB) are also implicated in reduced maturation rates. We sought to correlate differences in upper extremity arterial anatomy to race and gender. All upper extremity vascular mapping ultrasounds from 2013 to 2014 were retrospectively reviewed. A total of 509 arms in 284 patients were evaluated. Men had significantly higher mean arterial diameters than women at the elbow brachial (4.7 vs 3.9 mm, P < 0.01) and wrist radial arteries (2.1 vs 1.9 mm, P = 0.03). There were 20 (7%) patients with HBB of at least one arm, and 7 (2.5%) patients with bilateral HBB. African-American patients had significantly higher rates of both unilateral HBB (15.9% vs 5.4%, P = 0.02) and bilateral HBBs (9.1% vs 1.3%, P = 0.01). In conclusion, men had significantly larger arteries than women, and African-Americans had a higher rate of HBB than non-African-Americans. Consideration should be given for routine preoperative ultrasound to assess arterial anatomy before arteriovenous fistulas creation, particularly in women and in African-Americans.

Surveys of pupae and larvae of black flies (Diptera: Simuliidae) were carried out in Thua Thien Hue Province of central Vietnam, and Lam Dong Province of southern Vietnam in 2014. A total of 26 species belonging to the genus Simulium were collected, consisting of eight known species, one newly recorded species, and 17 new species (of which three species of the subgenus Nevermannia were described in 2014). The remaining 14 new species (nine of the subgenus Gomphostilbia and five of the subgenus Simulium) are described here based on females, males, pupae and mature larvae. The total number of species of black flies in Vietnam is now 46. Keys to identify all 26 species recorded from the two provinces of Vietnam are given for females, males, pupae and mature larvae.

This study, using C57BL/6J mice with streptozotocin (STZ)-induced diabetes, aimed to determine whether Bifidobacterium species (spp.) both induces the expressions of proteins in the insulin signaling pathway and enhances the expressions of certain adipocytokines. The protein expressions of IκB kinase alpha (IKKα), IκB kinase beta (IKKβ), nuclear factor-kappaB inhibitor alpha (IκBα), and the mitogen-activated protein kinase (MAPK) pathway were also investigated. Oral administration of Bifidobacterium spp. reduced blood glucose levels significantly and increased the protein expressions of insulin receptor beta, insulin receptor substrate 1, protein kinase B (Akt/PKB), IKKα, and IκBα. Extracellular-signal-regulated kinase 2 (ERK2) showed increased expression. Bifidobacterium spp. also induced the adiponectin expression and decreased both macrophage chemoattractant protein-1 (MCP-1) and interleukin-6 (IL-6) expression. In addition, IKKβ, c-Jun NH2-terminal kinase (JNK) and p38 MAP kinase expressions showed no significant changes in both groups. In conclusion, Bifidobacterium spp. may be the promising bacteria for treating diabetes.

Three new species of black flies, Simulium (Nevermannia) langbiangense, S. (N.) phami, and S. (N.) bachmaense, are described on the basis of females, males, pupae and larvae collected in Vietnam. All three species are assigned to the Simulium feuerborni species-group of Simulium (Nevermannia). Simulium (N.) langbiangense sp. nov. is characterized by the female sensory vesicle with a large opening, and a short common basal stalk of the six pupal gill filaments, S. (N.) phami sp. nov. is most striking in having the pupal gill with five filaments, a character not reported in species of the S. feuerborni species-group, and S. (N.) bachmaense sp. nov. is characterized by the female genital fork with a triangular lobe-like projection pointed posteromedially on each arm, and the small larval postgenal cleft. This represents the first record of the S. feuerborni species-group from Vietnam.

The intestinal microbiome might be an important contributor to the development of type 2 diabetes. This study was designed to test the hypothesis that oral administration of Bifidobacterium species (spp.) (including B. longum, B. bifidum, B. infantis, and B. animalis) may both ameliorate insulin resistance and reduce the expressions of inflammatory adipocytokines. Male Swiss-Webster mice fed a high-fat diet with or without oral administration of Bifidobacterium spp. for 5 weeks were subjected to an insulin tolerance test and an oral glucose tolerance test. Plasma levels of glucose at 30, 60, 90 and 120 min after insulin injection or glucose administration were significantly lower in the Bifidobacterium spp. than in the control group (P < 0.05), showing the beneficial effect of oral administration on insulin resistance in obese Swiss mice. In addition, Bifidobacterium spp. increased the adiponectin mRNA level and decreased those of monocyte chemoattractant protein 1 and interleukin 6 in non-diabetic C57BL/6J mice fed a normal diet, indicating a molecular mechanism which may ameliorate the inflammatory state, thereby reducing insulin resistance. In conclusion, oral administration of Bifidobacterium spp. improves insulin resistance and glucose tolerance in obese mice by reducing inflammation, as it does in the lean state.

The distribution of unengorged larvae of Leptotrombidium pallidum, L. fuji and L. kitasatoi in and around 12 rodent-nest holes in Oita Prefecture, Japan was studied using the Tullgren funnel apparatus. Soil was taken from each nest hole, and the ground-surface soil and litter from the surrounding area A (an inner quadrate of 20 cm x 20 cm except the nest hole), and also from the outer area B (an outer quadrate of 40 cm x 40 cm excluding A and the nest hole) were sampled, separately. The numbers (% of the total) of L. pallidum collected from soil samples of the nest holes and areas A and B were 38 (19.0), 111 (55.5) and 30 (15.0); those of L. fuji were 171 (58.8), 104 (35.7) and 14 (4.8); those of L. kitasatoi were 35 (77.9), 7 (15.6) and 3 (6.7), and those of G. saduski were 20 (50.0), 17 (42.5) and 3 (7.5). The larvae recovered from litter samples were few, representing 0-8.5% of the total. It is shown that unengorged larvae of these species are distributed not only in the nest holes but also in the nearby areas, and exist mainly on (or in) the soil.

The current study surveyed the 56-kDa type-specific antigen (TSA) gene DNAs of Orientia tsutsugamushi (Hayashi) in approximately 4.000 unengorged chiggers obtained from the soil or ground surface in an endemic and a nonendemic area of the Tsutsugamushi disease in Oita Prefecture, southwestern Japan, by nested polymerase chain reaction (PCR). Serotypes of O. tsutsugamushi were identified by restriction fragment-length polymorphism (RFLP) analysis. In the endemic area, 242 pools from five species [234 pools of Leptotrombidium scutellare (Nagayo, Miyagawa, Mitamura, Tamiya and Tenjin), two L. pallidum (Nagayo, Miyagawa, Mitamura and Tamiya), four L. kitasatoi (Fukuzumi & Obata), one L. fuji (Kuwata, Berge and Philip), and one Neotrombicula japonica (Tanaka, Kaiwa, Teramura and Kagaya)] were tested, and eight (seven pools of L. scutellare and one N. japonica) were positive for O. tsutsugamushi. Among the seven positive pools of L. scutellare, the distribution of serotypes was as follows: Kuroki (4), Gilliam (1), Karp (1), and Kawasaki (1). The first two serotypes (Kuroki and Gilliam) were identified for the first time in this species. In the nonendemic area, 128 pools from eight species were tested, and 13 were positive for O. tsutsugamushi. The positive rate was as follows: L. pallidum (4/41). L. kitasatoi (1/18), Gahrliepia saduski Womersley (2/10), L. fuji (4/50), L. himizu (Sasa, Kumada, Hayashi, Enomoto, Fukuzumi and Obata) (1/2), and Miyatrombicula kochiensis (Sasa, Kawashima and Egashira) (1/3). The latter three species were shown for the first time to harbor O. tsutsugamushi. All ofthe positive pools were Kuroki, except for two pools (one L. pallidum and one L. fuji), which were Gilliam (this serotype was also detected for the first time in L. pallidum). Further analysis revealed no differences in the nucleotide sequences (125 bp of variable domain 1 of TSA gene) of the same serotypes (i.e., Kuroki and Gilliam) among the positive samples. These data indicate that O. tsutsugamushi was widely distributed in various trombiculid species, even in the nonendemic area. The data are also suggestive of a possible horizontal transmission of O. tsutsugamushi among trombiculid species.