P. gingivalis type II followed by type IV were considered as disease-associated strains that account for the pathogenesis of chronic periodontitis in Chinese adults.
Our laboratory is interested in the genes and gene products involved in the interactions between Porphyromonas gingivalis (Pg) and the host. These interactions may occur in either the periodontal tissues or other non-oral host tissues such as those of the cardiovascular system. We have previously reported the cloning of several genes encoding hemagglutinins, surface proteins that interact with the host tissues, and are investigating their roles in the disease process. Primary among these is HagA, a very large protein with multiple functional groups that have significant sequence homology to protease genes of this species. Preliminary evidence indicates that an avirulent Salmonella typhimurium strain containing hagA is virulent in mice. These data indicate that HagA may be a key virulence factor of Pg. Additionally, we are investigating the invasion of primary human coronary artery endothelial cells (HCAEC) by Pg because of the recent epidemiological studies indicating a correlation between periodontal disease (PD) and coronary heart disease (CHD). We found that some, but not all, strains of Pg are able to invade these cells. Scanning electron microsopy of the infected HCAEC demonstrated that the invading organisms initially attached to the host cell surface as aggregates and by a "pedestal"-like structure. By transmission electronmicroscopy it could be seen that internalized bacteria were present within multimembranous compartments localized with rough endoplasmic reticulum. In addition, invasion of the HCAEC by Pg resulted in an increase in the degradation of long-lived cellular proteins. These data indicate that Pg are present within autophagosomes and may use components of the autophagic pathway as a means to survive intracellularly. However, Pg presence within autophagosomes in KB cells could not be observed or detected. It is therefore likely that Pg uses different invasive mechanisms for different host cells. This and the role of HagA in invasion is currently being investigated further.
The relationship between the features of bone marrow donor and the quality of marrow harvest has been unclear because most of bone marrow registries have multiple collection centers with somewhat different harvest procedures. We are able to address this issue for Tzu Chi General Hospital is the only collection center affiliated with Tzu Chi Taiwan Bone Marrow Registry. Between November 1997 and March 2002, data of 286 healthy unrelated donors was analyzed to correlate with the cell density of total nucleated cell in bone marrow harvests. The harvest procedure was standardized by single-hole harvest needle under general anesthesia. The operation staffs were restricted within the members of Oncology-Hematology division. The results showed that the cell density of bone marrow harvest was positively correlated with donor body weight and peripheral white blood cell count P = 0.0475, P < 0.0001, but negatively correlated with the total volume of bone marrow harvest P < 0.0001. We recommend that if multiple human leukocyte antigen-matched donors are available, donor with higher body weight and/or higher white blood cell count be selected for allogeneic bone marrow transplantation.
The rice disease bakanae, caused by Fusarium fujikuroi Nirenberg, has been present in Taiwan for over a century. To better understand the genetic diversity and structure of F. fujikuroi, a set of 16 polymorphic simple sequence repeat (SSR) markers were newly developed and used to analyze 637 F. fujikuroi isolates collected in 14 cities or counties around Taiwan from 1996 to 2013. On the basis of Bayesian clustering, the isolates were classified into four highly differentiated clusters: cluster B likely derived from the more widespread and genetically diversified clusters A or C, and cluster D was restricted to four cities or counties and may have been introduced from unknown sources genetically distinct from clusters A, B, and C. The coexistence of both mating types (MAT1-1:MAT1-2 = 1:1.88) and the highly diversified vegetative compatibility groups (VCG) (16 VCG among the 21 assessed isolates) suggest the likelihood of sexual reproduction in the field. However, the biased mating type ratios and linkage disequilibrium in the population suggest nonrandom mating between individuals. A significant pattern of isolation by distance was also detected, which implies a geographical restricted gene flow and low dissemination ability of F. fujikuroi. Evaluation of 24 representative isolates on eight rice varieties revealed differential levels of virulence, however no clear pattern of specific variety x isolate interaction was observed. Investigations of the differences in virulence and fungicide sensitivity between 8 early isolates (1998 and 2002) and 52 recent isolates (2012) indicate the evolution of increased resistance to the fungicide prochloraz in F. fujikuroi in Taiwan.
Aim Physical inactivity can cause physical frailty and sarcopenia. We investigated the effects of a hybrid intervention combining commercial exergaming with physical therapy, and clarified the reasons for physical inactivity among older adults. Methods This was a pilot study of older participants recruited from a long‐term care facility assigned to either an experimental or a control group. The experimental group received a 90‐min hybrid intervention twice a week for 12 weeks, whereas the control group received only assessment. The outcomes included muscle strength, walking speed, endurance, the Timed Up and Go test, the Berg Balance Scale, flow state, and safety. Results We enrolled 17 residents (42.5% of those eligible), with eight in the experimental group. After 12 weeks, the handgrip strength and Timed Up and Go test scores significantly improved in the experimental group. The number of participants with handgrip strength exceeding the cut‐off for sarcopenia, Timed Up and Go test scores exceeding the minimal detectable change, and walking speed exceeding the minimum clinically significant difference were greater in the experimental group than in the control group. Furthermore, no significant adverse events were reported; all participants in the experimental group entered the flow state. Overall, 32.5% of participants reported physical inactivity with common reasons, including laziness (77%), a lack of interest (69%) and the hassle of engagement (46%). Conclusions The hybrid intervention is safe and feasible, and could delay disability in older adults. Approximately one‐third of the participants were physically inactive. Further study is required to reduce physical inactivity. Geriatr Gerontol Int 2019; 19: 147–152.
An in vivo expression technology (IVET) system was designed to identify previously unknown virulence genes of Porphyromonas gingivalis. Fourteen ivi (for in vivo induced) genes that are induced during infection in a mouse abscess model were identified in our study. Of these, seven had homology to genes in the NCBI database, and the rest had no homology to reported DNA sequences. In order to determine virulence-related properties of these genes, three mutant strains, deleted of ivi8 (no homology to genes in the database), ivi10 (homologous to a putative TonB-dependent outer membrane receptor protein), and ivi11 (an immunoreactive 33-kDa antigen PG125 in P. gingivalis), were created. The mutants were tested in a mouse abscess model for alterations in virulence relative to the wild type by a competition assay in BALB/c mice. After 5 days we observed the enrichment of the wild-type strain over mutant strains ⌬ivi10 and ⌬ivi11, which indicated that mutant strains ⌬ivi10 and ⌬ivi11 are less able to survive in this model than the wild-type strain, while ⌬ivi8 survives as well as the wild-type strain. We propose that knockout of these ivi genes reduced the ability of the mutated P. gingivalis to survive and cause infection compared to the wild-type strain at the site of injection. Also, in separate experiments, groups of mice were challenged with subcutaneous injections of each individual mutant strain (⌬ivi8, ⌬ivi10, and ⌬ivi11) or with the wild-type strain alone and were then examined to assess their general health status. The results showed that knockout of these ivi genes conferred a reduction in virulence. The ability of the mutants to invade KB cells compared to the wild type was also determined. Interestingly, the CFU counts of the mutant strain ⌬ivi10 recovered from KB cells were eight times lower than those of the wild type, indicating that this mutant has a lower capacity for invasion. These results demonstrate that IVET is a powerful tool in discovering virulence genes and the significant role that ivi genes play in the pathogenesis of this species.
The presence of pleural effusion predicts poor PFS and OS in lung adenocarcinoma patients receiving TKIs as the first-line treatment. Additional studies are warranted to elucidate the underlying mechanisms and determine novel strategies for improving the outcome of these patients.
The exclusion rate was high at the beginning of our study as in previous studies. Understanding the reasons for UCB exclusion may help to improve the efficiency of UCB banking programs in the future.
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