CAMELLIA SINENSIS VAR. MADOENSIS (SECT. THEA, THEACEAE), A NEW TAXON FROM VIETNAM

Camellia sinensis var. madoensis is described and illustrated as a new variety of Camellia sinensis (section Thea, Theaceae) from Xuan Loc Commune, Song Cau District, Phu Yen Province. The new variety is easily distinguishable from C. sinensis var. sinensis by style free ½ to the base. The ITS sequence of this variety is also different from that of Camellia sinensis and its other varieties, while the matK gene sequences are nearly identical among Camellia taxa.Camellia sinensis var. madoensis được mô tả và minh họa với vai trò là một thứ mới của Camellia sinensis (section Thea, Theaceae) ghi nhận tại xã Xuân Lộc, huyện Sông Cầu, tỉnh Phú Yên. Thứ mới này có thể dễ dàng phân biệt với C. sinensis var. sinensis bởi vòi nhụy rời ½ tính từ đế. Trình tự ITS của thứ này cũng khác với Camellia sinensis và các thứ khác của nó

Oil pollution in the Vietnamese waters

Enumeration of hydrocarbon-degrading microorganisms (HDM) and their degradative capacity studies were carried out in area IV of South China Sea (Vietnamese water). Microbial most probable number (MPN) varied from 101 to 105 cell/ ml of surface seawater or gram of sediment. Some microbial communities and bacterial strains isolated from 97 collected samples show high hydrocarbon degradation and surfactant producing abilities. Preliminary results of our microbial study indicated that oil pollution in IV area was not found in 30 research stations. Slight oil contamination was observed in 28 survey stations

Oil pollution in the Vietnamese waters

Enumeration of hydrocarbon-degrading microorganisms (HDM) and their degradative capacity studies were carried out in area IV of South China Sea (Vietnamese water). Microbial most probable number (MPN) varied from 101 to 105 cell/ ml of surface seawater or gram of sediment. Some microbial communities and bacterial strains isolated from 97 collected samples show high hydrocarbon degradation and surfactant producing abilities. Preliminary results of our microbial study indicated that oil pollution in IV area was not found in 30 research stations. Slight oil contamination was observed in 28 survey stations

CAMELLIA SINENSIS VAR. MADOENSIS (SECT. THEA, THEACEAE), A NEW TAXON FROM VIETNAM

Camellia sinensis var. madoensis is described and illustrated as a new variety of Camellia sinensis (section Thea, Theaceae) from Xuan Loc Commune, Song Cau District, Phu Yen Province. The new variety is easily distinguishable from C. sinensis var. sinensis by style free ½ to the base. The ITS sequence of this variety is also different from that of Camellia sinensis and its other varieties, while the matK gene sequences are nearly identical among Camellia taxa

Aminoglycoside antibiotics impair calcium entry but not viability and motility in isolated cochlear outer hair cells

Cochlear outer hair cells have been well established as primary targets of the ototoxic actions of aminoglycoside antibiotics. These cells, isolated from the guinea pig cochlea and maintained in short-term culture, were used as a model for evaluating the acute effects of gentamicin on cell viability, depolarization-induced transmembrane calcium flux, and depolarization-induced motile responses. On the basis of morphology and fluorochromasia, the presence of extracellular gentamicin as high as 5 mM did not affect the viability of the cells for up to 6 hr, the longest time tested. Viable cells showed binding of fluorescently tagged gentamicin to their base but excluded the drug from their cytoplasm. In response to [K + ]-depolarization, intracellular calcium levels (monitored with the fluorescent calcium-sensitive dye fluo-3) increased from a resting value of 218 ± 102 nM to 2,018 ± 1,077 nM concomitant with a cell shortening of 0.7% ± 1.3%. The depolarization-induced calcium increase was apparently caused by calcium entry into the cell as it was inhibited by the calcium-channel blocker methoxyverapamil and prevented in the absence of extracellular calcium. Both gentamicin and neomycin blocked the [K + ]-induced calcium increase at an IC 50 of 50 ΜM. Despite the inhibition of calcium entry the ability of the outer hair cells to shorten under [K + ]-depolarization was not impaired; in fact, cell shortening was even more pronounced in the absence of calcium influx (2.6% ± 1.4%). This argues effectively against the existence of a calcium-dependent actomyosin-mediated component in [K + ]-induced shape changes. The results suggest the existence of voltage-gated calcium channels in outer hair cells and that calcium influx through these channels is impaired by the aminoglycoside antibiotics neomycin and gentamicin. This action may be part of the acute ototoxic mechanism of these molecules. Furthermore, the results not only confirm the calcium independence of the depolarization-induced motility but also suggest that calcium influx into outer hair cells opposes cell shortening.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50224/1/490240226_ftp.pd

Three molecular steps of aminoglycoside ototoxicity demonstrated in outer hair cells

Previously postulated molecular mechanisms of aminoglycoside ototoxicity were investigated in outer hair cells in vitro. Cells were isolated by microdissection from the organ of Corti of the guinea pig and maintained in Hank's balanced salt solution. (1) Approx. 100 cells (the standard number per assay) bound 432 +/- 198 pmol calcium as determined with 45Ca2+ (1.2 mM). 1 mM neomycin or gentamicin lowered this value by 28% and 45%, respectively. (2) Binding of radiolabeled gentamicin (28 fmol per 100 cells at 0.1 [mu]M gentamicin) was reduced by 55% by 1 mM neomycin or spermine. Washing with an excess of unlabeled gentamicin displaced only 60% of the drug, the remainder being tightly bound to a less accessible compartment. Incubation at low temperature essentially abolished gentamicin uptake. (3) Phospholipids were labeled with [32P]orthophosphate which was mostly incorporated into phosphatidylinositol 4,5-bisphosphate (PIP2), phosphatidylinositol 4-phosphate, phosphatidylinositol, and phosphatidic acid. When the lipids were chromatographed over immobilized gentamicin PIP2, in contrast to other lipids, was strongly retained. These results are compatible with the following actions of aminoglycosides in outer hair cells: (1) competition with calcium; (2) energy-dependent uptake competitive with polyamines; and (3) binding to the phospholipid PIP2.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26848/1/0000410.pd

The role of nutritional risk evaluation in predicting adverse outcomes among patients with severe COVID-19 in Vietnam

IntroductionAs sufficient nutrition helps alleviate catabolic stress and modulate the systemic inflammatory response of the body, it plays an indispensable role in the good prognosis of critically ill patients. Thus, this study aimed to investigate the malnutrition of patients with severe COVID-19 and its association with adverse treatment outcomes.MethodsWe conducted a retrospective cross-sectional study in two provincial hospitals in Hanoi from February to April 2022. Participants were patients with severe COVID-19 admitted to the Intensive Care Unit (ICU). Malnutrition risk were evaluated by Nutritional Risk Screening-2002 (NRS), Global Leadership Initiative on Malnutrition (GLIM), Prognostic Nutritional Index (PNI), and the adverse prognosis was assessed by Acute Physiology and Chronic Health Evaluation II (APACHE II). The multivariate receiver-operating characteristic (ROC) curve was applied to estimate the predictive ability of those criteria regarding worse treatment results.ResultsThe percentages of malnutrition measured by NRS, GLIM, PNI, and BMI were 62.6, 51.5, 42.9, and 16.6%, respectively. Patients with more severe malnutrition assessed by GLIM, PNI, and having above target fasting blood glucose (FBG) (≥10.0 mmol/L) were more likely to have higher APACHE scores. PNI had a better diagnostic performance than NRS and BMI (AUC = 0.84, 0.81, and 0.82, respectively). In addition, FBG revealed a good prognostic implication (AUC = 0.84).ConclusionA relatively high percentage of patients experienced moderate and severe malnutrition regardless of screening tools. Individuals at higher risk of malnutrition and high FBG were predicted to have more adverse treatment outcomes. It is recommended that nutritional screening should be conducted regularly, and personalizing nutritional care strategies is necessary to meet patients’ nutrient demands and prevent other nutrition-related complications

Frequent inappropriate use of unweighted summary statistics in systematic reviews of pathogen genotypes or genogroups.

OBJECTIVES: Our study aimed to systematically assess and report the methodological quality used in epidemiological systematic reviews (SRs) and meta-analysis (MA) of pathogen genotypes/genogroups. STUDY DESIGN AND SETTING: Nine electronic databases and manual search of reference lists were used to identify relevant studies. The method types were divided into three groups: 1) with weighted pooling analysis (which we call MA), (2) unweighted analysis of the study-level measures (which we call summary statistics), and (3) without any data pooling (which we call SR only). Characteristics were evaluated using Assessment of Multiple Systematic Reviews (AMSTAR), Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA), and Risk Of Bias In Systematic reviews (ROBIS) tools. The protocol was registered in PROSPERO with CRD42017078146. RESULTS: Among 36 included articles, 5 (14%) studies conducted SR only, 16 (44%) performed MA, and 15 (42%) used summary statistics. The univariable and multivariable linear regression of AMSTAR and PRISMA scores showed that MA had higher quality compared with those with summary statistics. The SR only and summary statistics groups had approximately equal scores among three scales of AMSTAR, PRISMA, and ROBIS. The methodological quality of epidemiological studies has improved from 1999 to 2017. CONCLUSION: Despite the frequent use of unweighted summary statistics, MA remains the most suitable method for reaching rational conclusions in epidemiological studies of pathogen genotypes/genogroups

Functional Hair Cell Mechanotransducer Channels Are Required for Aminoglycoside Ototoxicity

Aminoglycosides (AG) are commonly prescribed antibiotics with potent bactericidal activities. One main side effect is permanent sensorineural hearing loss, induced by selective inner ear sensory hair cell death. Much work has focused on AG's initiating cell death processes, however, fewer studies exist defining mechanisms of AG uptake by hair cells. The current study investigated two proposed mechanisms of AG transport in mammalian hair cells: mechanotransducer (MET) channels and endocytosis. To study these two mechanisms, rat cochlear explants were cultured as whole organs in gentamicin-containing media. Two-photon imaging of Texas Red conjugated gentamicin (GTTR) uptake into live hair cells was rapid and selective. Hypocalcemia, which increases the open probability of MET channels, increased AG entry into hair cells. Three blockers of MET channels (curare, quinine, and amiloride) significantly reduced GTTR uptake, whereas the endocytosis inhibitor concanavalin A did not. Dynosore quenched the fluorescence of GTTR and could not be tested. Pharmacologic blockade of MET channels with curare or quinine, but not concanavalin A or dynosore, prevented hair cell loss when challenged with gentamicin for up to 96 hours. Taken together, data indicate that the patency of MET channels mediated AG entry into hair cells and its toxicity. Results suggest that limiting permeation of AGs through MET channel or preventing their entry into endolymph are potential therapeutic targets for preventing hair cell death and hearing loss