Mahidol University

About: Mahidol University is a education organization based out in Bangkok, Nakhon Pathom, Thailand. It is known for research contribution in the topics: Population & Malaria. The organization has 23758 authors who have published 39761 publications receiving 878781 citations.

Human Colorectal Cancer: High Frequency of Deletions at Chromosome 1p35

Abstract: Cytogenetic analyses of human colon cancer cells have revealed a high frequency of chromosome 1p deletions among other chromosomal abnormalities. In order to find out whether these chromosomal alterations are manifestations of loss of genetic material, we surveyed DNA of 62 primary tumors, 7 metastases, and matching peripheral blood cells with a panel of polymorphic DNA probes that detect different loci on chromosome 1p. A portion of the probes was derived from a microclone bank generated by microdissection and microcloning of 1p35→pter DNA. In 42% of the colon carcinomas allelic loss was observed with at least one probe. The deletions were of different sizes but always included a region involving band 1p35, except for two tumors in which allelic loss was detected more proximally. The frequency of 1p deletion in the metastases was higher than in the primary tumors. These data indicate that genetic information related to tumorigenesis is located within or nearby region 1p35 and that deletion of this region occurs later in tumor development. Our results add to the number of genetic changes presumably involved in colon cancerogenesis.

Rise of Deep Learning for Genomic, Proteomic, and Metabolomic Data Integration in Precision Medicine

Abstract: Machine learning (ML) is being ubiquitously incorporated into everyday products such as Internet search, email spam filters, product recommendations, image classification, and speech recognition. New approaches for highly integrated manufacturing and automation such as the Industry 4.0 and the Internet of things are also converging with ML methodologies. Many approaches incorporate complex artificial neural network architectures and are collectively referred to as deep learning (DL) applications. These methods have been shown capable of representing and learning predictable relationships in many diverse forms of data and hold promise for transforming the future of omics research and applications in precision medicine. Omics and electronic health record data pose considerable challenges for DL. This is due to many factors such as low signal to noise, analytical variance, and complex data integration requirements. However, DL models have already been shown capable of both improving the ease of data encoding and predictive model performance over alternative approaches. It may not be surprising that concepts encountered in DL share similarities with those observed in biological message relay systems such as gene, protein, and metabolite networks. This expert review examines the challenges and opportunities for DL at a systems and biological scale for a precision medicine readership.

Practical PCR genotyping protocols for Plasmodium vivax using Pvcs and Pvmsp1

Abstract: Plasmodium vivax is the second most prevalent malaria parasite affecting more than 75 million people each year, mostly in South America and Asia. In addition to major morbidity this parasite is associated with relapses and a reduction in birthweight. The emergence and spread of drug resistance in Plasmodium falciparum is a major factor in the resurgence of this parasite. P. vivax resistance to drugs has more recently emerged and monitoring the situation would be helped, as for P. falciparum, by molecular methods that can be used to characterize parasites in field studies and drug efficacy trials. Practical PCR genotyping protocols based on polymorphic loci present in two P. vivax genetic markers, Pvcs and Pvmsp1, were developed. The methodology was evaluated using 100 P. vivax isolates collected in Thailand. Analysis revealed that P. vivax populations in Thailand are highly diverse genetically, with mixed genotype infections found in 26 % of the samples (average multiplicity of infection = 1.29). A large number of distinguishable alleles were found for the two markers, 23 for Pvcs and 36 for Pvmsp1. These were generally randomly distributed amongst the isolates. A total of 68 distinct genotypes could be enumerated in the 74 isolates with a multiplicity of infection of 1. These results indicate that the genotyping protocols presented can be useful in the assessment of in vivo drug efficacy clinical trials conducted in endemic areas and for epidemiological studies of P. vivax infections.

The Effect of Periodontal Therapy on Uncontrolled Type 2 Diabetes Mellitus in Older Subjects

Abstract: Objective: The purpose of this study was to examine the effect of periodontal therapy on glycemic control in older type 2 diabetic patients. Methods: Fifty-two diabetic patients, age 55–80 years (mean age = 61 years), with glycated hemoglobin (HbA1c) 7.5–11.0% (mean ± s.d. = 8.98 ± 0.88) and severe periodontitis were included in the present study. The treatment group received mechanical periodontal treatment combined with systemic doxycycline, 100 mg day−1 for 14 days. The control group received neither periodontal treatment nor systemic doxycycline. Clinical periodontal parameters, fasting plasma glucose (FPG), and HbA1c levels were measures at baseline and 3 months. Results: Periodontal treatment significantly improved periodontal status of the treatment group (P < 0.05), however the reduction in the level of FPG and HbA1c did not reach significance. In the control group, no significant changes in clinical periodontal parameters, FPG and HbA1c levels were observed, except for significant increase in attachment loss (P < 0.05). Comparing the two groups, although the 3-month level of HbA1c of the treatment group was lower than that of the control group, the difference did not reach significance. Conclusions: The results of the present study indicate that the periodontal condition of older Thais with uncontrolled diabetes is: (a) significantly improved 3 months after mechanical periodontal therapy with adjunctive systemic antimicrobial treatment, and (b) rapidly deteriorating without periodontal treatment. The effect of periodontal therapy on the glycemic control of older uncontrolled diabetics will require further studies that will have to include much larger sample sizes.

Application of genetic markers to the identification of recrudescent Plasmodium falciparum infections on the northwestern border of Thailand

Abstract: Parasite genotyping by the polymerase chain reaction was used to distinguish recrudescent from newly acquired Plasmodium falciparum infections in a Karen population resident on the northwestern border of Thailand where malaria transmission is low (one infection/person/year). Plasmodium falciparum infections were genotyped for allelic variation in three polymorphic antigen loci, merozoite surface proteins-1 and -2 (MSP-1 and -2) and glutamaterich protein (GLURP), before and after antimalarial drug treatment. Population genotype frequencies were measured to provide the baseline information to calculate the probability of a new infection with a different or the same genotype to the initial pretreatment isolate. Overall, 38% of the infections detected following treatment had an identical genotype before and up to 121 days after treatment. These post-treatment genotypes were considered recrudescent because of the low (< 5%) probability of repeated occurrence by chance in the same patient. This approach allows studies of antimalarial drug treatment to be conducted in areas of low transmission since recrudescences can be distinguished confidently from newly acquired infections.