MyMedR

Displaying all 4 publications

Abstract:

Sort:

Fulltext Polymerase chain reaction-restriction fragment length polymorphism method for differentiation of uropathogenic specific protein gene types

Lai YM, Zaw MT, Shamsudin SB, Lin Z

J Microbiol Immunol Infect, 2016 Aug;49(4):591-4.
PMID: 26212311 DOI: 10.1016/j.jmii.2015.06.002

The putative pathogenicity island (PAI) containing the uropathogenic specific protein (usp) gene and three small open reading frames (orfU1, orfU2, and orfU3) encoding 98, 97, and 96 amino acid proteins is widely distributed among uropathogenic Escherichia coli (UPEC) strains. This PAI was designated as PAIusp. Sequencing analysis of PAIusp has revealed that the usp gene can be divided into two types - uspI and uspII - based on sequence variation at the 3' terminal region and the number and position of orfUs differ from strain to strain. Based on usp gene types and orfU sequential patterns, PAIusp can be divided into four subtypes. Subtyping of PAIusp is a useful method to characterize UPEC strains. In this study, we developed a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method to differentiate usp gene types. This method could correctly identify the usp gene type in usp-positive UPEC strains in our laboratory.
Fulltext Evaluation of PAIusp subtyping to characterize uropathogenic E. coli isolates

Lai YM, Zaw MT, Shamsudin SB, Lin Z

J Infect Dev Ctries, 2016 Oct 31;10(10):1053-1058.
PMID: 27801366 DOI: 10.3855/jidc.6944

INTRODUCTION: Uropathogenic virulence factors have been identified by comparing the prevalence of these among urinary tract isolates and environmental strains. The uropathogenic-specific protein (USP) gene is present on the pathogenicity island (PAI) of uropathogenic Escherichia coli (UPEC) and, depending on its two diverse gene types and the sequential patterns of three open reading frame units (orfUs) following it, there is a method to characterize UPEC epidemiologically called PAIusp subtyping.
METHODOLOGY: A total of 162 UPEC isolates from Sabah, Malaysia, were tested for the presence of the usp gene and the sequential patterns of three orfUs following it using polymerase chain reaction (PCR). In addition, by means of triplex PCR, the prevalence of the usp gene was compared with other two VFs of UPEC, namely alpha hemolysin (α-hly) and cytotoxic necrotizing factor (cnf-1) genes encoding two toxins.
RESULTS: The results showed that the usp gene was found in 78.40% of UPEC isolates, indicating that its prevalence was comparable to that found in a previous study in Japan. The two or three orfUs were also associated with the usp gene in this study. All the PAIusp subtypes observed in Japan were present in this study, while subtype IIa was the most common in both studies. The usp gene was observed in a higher percentage of isolates when compared with α-hly and cnf-1 genes.
CONCLUSIONS: The findings in Japan and Sabah, East Malaysia, were similar, indicating that PAIusp subtyping is applicable to the characterization of UPEC strains epidemiologically elsewhere in the world.
Non-hypertensive gestational diabetes mellitus: Placental histomorphology and its association with perinatal outcomes

Lai YM, Tan GC, Shah SA, Abd Rahman R, Mohd Saleh MF, Mansor S, et al.

Placenta, 2024 Mar 06;147:21-27.
PMID: 38278001 DOI: 10.1016/j.placenta.2024.01.012

INTRODUCTION: Gestational diabetes mellitus (GDM) exerts a great impact on the placenta and reflects changes on placentas both morphological and functionally. The aims of this study are to evaluate the prevalence of placental histopathological lesions in pregnancies complicated by GDM compared to gestational age-matched controls, and their association with maternal and fetal complications.
METHODS: Fifty-four singleton GDM-complicated pregnancies were recruited and compared to 33 consecutive normal pregnancies. Two pathologists, blinded to all clinical data, reviewed and evaluated all histological samples of the placentas in accordance with Amsterdam criteria. Relevant demographic, clinical data and primary birth outcomes were recorded.
RESULTS: A myriad of histomorphological abnormalities, including chronic inflammation (n = 9/54, p = 0.031), histological chorioamnionitis (n = 23/54, p
Growth and thermal maturation of the Toba magma reservoir

Liu PP, Caricchi L, Chung SL, Li XH, Li QL, Zhou MF, et al.

Proc Natl Acad Sci U S A, 2021 11 09;118(45).
PMID: 34725149 DOI: 10.1073/pnas.2101695118

The Toba volcanic system in Indonesia has produced two of the largest eruptions (>2,000 km3 dense-rock equivalent [DRE] each) on Earth since the Quaternary. U-Pb crystallization ages of zircon span a period of ∼600 ky before each eruptive event, and in the run-up to each eruption, the mean and variance of the zircons' U content decrease. To quantify the process of accumulation of eruptible magma underneath the Toba caldera, we integrated these observations with thermal and geochemical modeling. We show that caldera-forming eruptions at Toba are the result of progressive thermal maturation of the upper crustal magma reservoir, which grows and chemically homogenizes, by sustained magma influx at average volumetric rates between 0.008 and 0.01 km3/y over the past 2.2 My. Protracted thermal pulses related to magma-recharge events prime the system for eruption without necessarily requiring an increased magma-recharge rate before the two supereruptions. If the rate of magma input was maintained since the last supereruption of Toba at 75 ka, eruptible magma is currently accumulating at a minimum rate of ∼4.2 km3 per millennium, and the current estimate of the total volume of potentially eruptible magma available today is a minimum of ∼315 km3 Our approach to evaluate magma flux and the rate of eruptible magma accumulation is applicable to other volcanic systems capable of producing supereruptions and thereby could help in assessing the potential of active volcanic systems to feed supereruptions.