Xiaohong Wu

Fundamental to most genetic analysis is availability of genomic DNA of adequate quality and quantity. Because DNA yield from human samples is frequently limiting, much effort has been invested in developing methods for whole genome amplification (WGA) by random or degenerate oligonucleotide-primed PCR. However, existing WGA methods like degenerate oligonucleotide-primed PCR suffer from incomplete coverage and inadequate average DNA size. We describe a method, termed multiple displacement amplification (MDA), which provides a highly uniform representation across the genome. Amplification bias among eight chromosomal loci was less than 3-fold in contrast to 4-6 orders of magnitude for PCR-based WGA methods. Average product length was >10 kb. MDA is an isothermal, strand-displacing amplification yielding about 20-30 microg product from as few as 1-10 copies of human genomic DNA. Amplification can be carried out directly from biological samples including crude whole blood and tissue culture cells. MDA-amplified human DNA is useful for several common methods of genetic analysis, including genotyping of single nucleotide polymorphisms, chromosome painting, Southern blotting and restriction fragment length polymorphism analysis, subcloning, and DNA sequencing. MDA-based WGA is a simple and reliable method that could have significant implications for genetic studies, forensics, diagnostics, and long-term sample storage.

Preparation of genomic DNA from clinical samples is a bottleneck in genotyping and DNA sequencing analysis and is frequently limited by the amount of specimen available. We use Multiple Displacement Amplification (MDA) to amplify the whole genome 10,000-fold directly from small amounts of whole blood, dried blood, buccal cells, cultured cells, and buffy coats specimens, generating large amounts of DNA for genetic testing. Genomic DNA was evenly amplified with complete coverage and consistent representation of all genes. All 47 loci analyzed from 44 individuals were represented in the amplified DNA at between 0.5- and 3.0-fold of the copy number in the starting genomic DNA template. A high-fidelity DNA polymerase ensures accurate representation of the DNA sequence. The amplified DNA was indistinguishable from the original genomic DNA template in 5 SNP and 10 microsatellite DNA assays on three different clinical sample types for 20 individuals. Amplification of genomic DNA directly from cells is highly reproducible, eliminates the need for DNA template purification, and allows genetic testing from small clinical samples. The low amplification bias of MDA represents a dramatic technical improvement in the ability to amplify a whole genome compared with older, PCR-based methods.

Sarcopenia is an age-related condition that is characterized by progressive and generalized loss of muscle mass and function. Exercise treatment has been the most commonly used intervention among elderly populations. We performed a systematic review and meta-analysis to evaluate the available literature related to the effects of exercise interventions/programs on muscle mass, muscle strength and physical performance in older adults with sarcopenia. We searched PubMed, EMBASE, MEDLINE and the Web of Science for randomized controlled trials and controlled clinical trials exploring exercise in older adults with sarcopenia published through July 2019 without any language restrictions. Pooled analyses were conducted using Review Manager 5.3, with standardized mean differences (SMDs) and fixed-effect models. A total of 3898 titles and abstracts were initially identified, and 22 studies (1041 individuals, 80.75% females, mean age ranged from 60.51 to 85.90 years) were included in the meta-analysis. The exercise programs in the studies consisted of 30 to 80 min of training, with 1 to 5 training sessions weekly for 6 to 36 weeks. Muscle strength (grip strength [SMD 0.57, 95 % CI 0.42 to 0.73, P <0.00001] and timed five chair stands [SMD -0.56, 95 % CI -0.85 to -0.28, P < 0.0001]) and physical performance (gait speed [SMD 0.44, 95 % CI 0.26 to 0.61, P < 0.00001] and the timed up and go test [SMD -0.97, 95 % CI -1.22 to -0.72, P < 0.00001]) showed significant improvement following exercise treatment, while no differences in muscle mass (ASM [SMD 0.15, 95 % CI -0.05 to 0.36, P = 0.15] and ASM/height² [SMD 0.21, 95 % CI -0.05 to 0.48, P = 0.12]) were detected. Exercise programs showed overall significant positive effects on muscle strength and physical performance but not on muscle mass in sarcopenic older adults.

Peri-implantitis or Periimplantitis is characterized as an inflammatory reaction that affects the hard and soft tissue, which results in loss of supporting bone and pocket formation surrounding the functioning osseointegrated implant. This review aimed to evaluate the effectiveness of surgical and non-surgical treatment of peri-implantitis. The data sources used was PubMed. Searches of this database were restricted to English language publications from January 2010 to June 2015. All Randomized Controlled Trials describing the treatments of peri-implantitis of human studies with a follow up of at least 6 months were included. Eligibility and quality were assessed and two reviewers extracted the data. Data extraction comprised of type, intensity provider, and location of the intervention. A total of 20 publications were included (10 involving surgical and 10 involving non-surgical mechanical procedure). The non-surgical approach involves the mechanical surface debridement using carbon or titanium currettes, laser light, and antibiotics whereas, surgical approach involves implantoplasty, elevation of mucoperiosteal flap and removal of peri-inflammatory granulation tissue followed by surface decontamination and bone grafting. This study reveals that non-surgical therapy tends to remove only the local irritant from the peri-implantitis surface with or without some additional adjunctive therapies agents or device. Hence, non-surgical therapy is not helpful in osseous defect. Surgical therapy in combination with osseous resective or regenerative approach removes the residual sub-gingival deposits additionally reducing the peri-implantitis pocket. Although there is no specific recommendation for the treatment of peri-implantitis, surgical therapy in combination with osseous resective or regenerative approach showed the positive outcome.