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1.
Malar J ; 20(1): 177, 2021 Apr 09.
Article in English | MEDLINE | ID: mdl-33836772

ABSTRACT

BACKGROUND: A goal of malaria epidemiological interventions is the detection and treatment of parasite reservoirs in endemic areas-an activity that is expected to reduce local transmission. Since the gametocyte is the only transmissible stage from human host to mosquito vector, this study evaluated the pre and post presence of gametocytes during a mass screening and treatment (MST) intervention conducted during 2013 in East Nusa Tenggara, Indonesia. METHODS: RT-qPCR targeting pfs25 and pvs25 transcripts-gametocyte molecular markers for Plasmodium falciparum and Plasmodium vivax, respectively, was performed to detect and quantify gametocytes in blood samples of P. falciparum and P. vivax-infected subjects over the course of the MST study. The presence of both asexual and sexual parasites in microscopic and submicroscopic infections was compared from the start and end of the MST, using proportion tests as well as parametric and non-parametric tests. RESULTS: Parasite prevalence remained unchanged for P. falciparum (6% = 52/811 versus 7% = 50/740, p = 0.838), and decreased slightly for P. vivax (24% = 192/811 versus 19% = 142/740, p = 0.035) between the MST baseline and endpoint. No significant difference was observed in gametocyte prevalence for either P. falciparum (2% = 19/803 versus 3% = 23/729, p = 0.353, OR = 1.34, 95%CI = 0.69-2.63), or P. vivax (7% = 49/744 versus 5% = 39/704, p = 0.442, OR = 0.83, 95%CI = 0.52-1.31). Even though there was an insignificant difference between the two time points, the majority of parasite positive subjects at the endpoint had been negative at baseline (P. falciparum: 66% = 29/44, P. vivax: 60% = 80/134). This was similarly demonstrated for the transmissible stage-where the majority of gametocyte positive subjects at the endpoint were negative at baseline (P. falciparum: 95% = 20/21, P. vivax: 94% = 30/32). These results were independent of treatment provided during MST activities. No difference was demonstrated in parasite and gametocyte density between both time points either in P. falciparum or P. vivax. CONCLUSION: In this study area, similar prevalence rates of P. falciparum and P. vivax parasites and gametocytes before and after MST, although in different individuals, points to a negligible impact on the parasite reservoir. Treatment administration based on parasite positivity as implemented in the MST should be reevaluated for the elimination strategy in the community. Trial registration Clinical trials registration NCT01878357. Registered 14 June 2013, https://www.clinicaltrials.gov/ct2/show/NCT01878357.


Subject(s)
Carrier State/epidemiology , Malaria, Falciparum/diagnosis , Malaria, Vivax/diagnosis , Mass Screening , Plasmodium falciparum/isolation & purification , Plasmodium vivax/isolation & purification , Adolescent , Adult , Aged , Aged, 80 and over , Carrier State/parasitology , Child , Child, Preschool , Female , Humans , Indonesia/epidemiology , Infant , Longitudinal Studies , Malaria, Falciparum/epidemiology , Malaria, Falciparum/prevention & control , Malaria, Vivax/epidemiology , Malaria, Vivax/prevention & control , Male , Middle Aged , Prevalence , Prospective Studies , Young Adult
2.
Heliyon ; 6(8): e04568, 2020 Aug.
Article in English | MEDLINE | ID: mdl-32775745

ABSTRACT

Graphene oxide (GO) based on coconut shell waste was successfully synthesized using a modified Hummers method, and the obtained GO was confirmed using XRD, FTIR, Raman spectroscopy, UV-Vis spectroscopy, and SEM-EDX. The XRD spectroscopy obtained the fractional content of the 2H graphite phase of 71.53%, 14.47% phosphorus, 10.02% calcium, and 3.97% potassium in coconut shell charcoal, where the GO sample tend to forms a phase of reduced graphene oxide (rGO). FTIR spectra shows compound functional groups of hydroxyl (- OH) at peak 1 (3449.92 cm-1), carboxyl (-COOH) at peak 2 (1719.42 cm-1) and peak 3 (1702.62 cm-1), and alcohol (C-OH) at peak 4 (1628.12 cm-1) and epoxy (CO) at peak 5 (1158.51 cm-1), which is similar to the GO synthesis from pure graphite. Raman spectroscopy analysis shows that the value of the ID/IG intensity ratio of the GO sample was 0.89 with a 2D single layer, and SEM results showed that surface morphology with an abundance of granular particles were found with different size distribution. The UV-visible results showed sufficient optical properties characterized by the spectrum, which formed because of the light absorption of the energy passed on the sample. The bandgap energy value of the sample obtained by the Tauc plot method was 4.38 eV, which indicates semiconductor properties.

3.
Clin Infect Dis ; 67(9): 1364-1372, 2018 10 15.
Article in English | MEDLINE | ID: mdl-29579195

ABSTRACT

Background: Mass screening and treatment (MST) aims to reduce malaria risk in communities by identifying and treating infected persons without regard to illness. Methods: A cluster-randomized trial evaluated malaria incidence with and without MST. Clusters were randomized to 3, 2, or no MST interventions: MST3, 6 clusters (156 households/670 individuals); MST2, 5 clusters (89 households/423 individuals); and MST0, 5 clusters (174 households/777 individuals). All clusters completed the study with 14 residents withdrawing. In a cohort of 324 schoolchildren (MST3, n = 124; MST2, n = 57; MST0, n = 143) negative by microscopy at enrollment, we evaluated the incidence density of malaria during 3 months of MST and 3 months following. The MST intervention involved community-wide expert malaria microscopic screening and standard therapy with dihydroartemisinin-piperaquine and primaquine for glucose-6 phosphate dehydrogenase-normal subjects. All blood examinations included polymerase chain reaction assays, which did not guide on-site treatment. Results: The risk ratios for incidence density of microscopically patent malaria in MST3 or MST2 relative to that in MST0 clusters were 1.00 (95% confidence interval [CI], .53-1.91) and 1.22 (95% CI, .42-3.55), respectively. Similar results were obtained with molecular analysis and species-specific (P. falciparum and P. vivax) infections. Microscopically subpatent, untreated infections accounted for 72% of those infected. Conclusions: Two or 3 rounds of MST within 3 months did not impact the force of anopheline mosquito-borne infection in these communities. The high rate of untreated microscopically subpatent infections likely explains the observed poor impact. Clinical Trials Registration: NCT01878357.


Subject(s)
Antimalarials/therapeutic use , Malaria/drug therapy , Malaria/transmission , Mass Screening , Adult , Cluster Analysis , Drug Therapy, Combination , Female , Humans , Incidence , Indonesia , Malaria/diagnosis , Male , Plasmodium falciparum/isolation & purification , Plasmodium vivax/genetics , Plasmodium vivax/isolation & purification , Treatment Outcome
4.
J Clin Microbiol ; 49(4): 1464-74, 2011 Apr.
Article in English | MEDLINE | ID: mdl-21289150

ABSTRACT

Severe early childhood caries (ECC), while strongly associated with Streptococcus mutans using selective detection (culture, PCR), has also been associated with a widely diverse microbiota using molecular cloning approaches. The aim of this study was to evaluate the microbiota of severe ECC using anaerobic culture. The microbial composition of dental plaque from 42 severe ECC children was compared with that of 40 caries-free children. Bacterial samples were cultured anaerobically on blood and acid (pH 5) agars. Isolates were purified, and partial sequences for the 16S rRNA gene were obtained from 5,608 isolates. Sequence-based analysis of the 16S rRNA isolate libraries from blood and acid agars of severe ECC and caries-free children had >90% population coverage, with greater diversity occurring in the blood isolate library. Isolate sequences were compared with taxon sequences in the Human Oral Microbiome Database (HOMD), and 198 HOMD taxa were identified, including 45 previously uncultivated taxa, 29 extended HOMD taxa, and 45 potential novel groups. The major species associated with severe ECC included Streptococcus mutans, Scardovia wiggsiae, Veillonella parvula, Streptococcus cristatus, and Actinomyces gerensceriae. S. wiggsiae was significantly associated with severe ECC children in the presence and absence of S. mutans detection. We conclude that anaerobic culture detected as wide a diversity of species in ECC as that observed using cloning approaches. Culture coupled with 16S rRNA identification identified over 74 isolates for human oral taxa without previously cultivated representatives. The major caries-associated species were S. mutans and S. wiggsiae, the latter of which is a candidate as a newly recognized caries pathogen.


Subject(s)
Bacteria, Anaerobic/classification , Bacteria, Anaerobic/isolation & purification , Dental Caries/microbiology , Bacteria, Anaerobic/genetics , Bacteria, Anaerobic/growth & development , Child , Child, Preschool , Cluster Analysis , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , Female , Humans , Male , Phylogeny , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA
5.
J Dent Res ; 89(11): 1224-9, 2010 Nov.
Article in English | MEDLINE | ID: mdl-20858780

ABSTRACT

Frequent consumption of cariogenic foods and bacterial infection are risk factors for early childhood caries (ECC). This study hypothesized that a short diet survey focused on frequency of foods, categorized by putative cariogenicity, would differentiate severe ECC (S-ECC) from caries-free children. Children's diets were obtained by survey and plaque bacteria detected by PCR from 72 S-ECC and 38 caries-free children. S-ECC children had higher scores for between-meal juice (p < 0.01), solid-retentive foods (p < 0.001), eating frequency (p < 0.005), and estimated food cariogenicity (p < 0.0001) than caries-free children. S-ECC children with lesion recurrence ate fewer putative caries-protective foods than children without new lesions. Streptococcus mutans (p < 0.005), Streptococcus sobrinus (p < 0.005), and Bifidobacteria (p < 0.0001) were associated with S-ECC, and S. mutans with S. sobrinus was associated with lesion recurrence (p < 0.05). S. mutans-positive children had higher food cariogenicity scores. Food frequency, putative cariogenicity, and S. mutans were associated with S-ECC individually and in combination.


Subject(s)
Dental Caries/microbiology , Diet , Streptococcus/isolation & purification , Beverages , Bifidobacterium/isolation & purification , Child , Child Behavior , Child, Preschool , Colony Count, Microbial , Dental Caries/etiology , Dental Plaque/microbiology , Diet, Cariogenic , Drinking , Drinking Behavior , Feeding Behavior , Female , Follow-Up Studies , Food , Fruit , Humans , Male , Recurrence , Socioeconomic Factors , Streptococcus mutans/isolation & purification , Streptococcus sobrinus/isolation & purification
6.
Theor Appl Genet ; 109(1): 80-91, 2004 Jun.
Article in English | MEDLINE | ID: mdl-15094992

ABSTRACT

This study focuses on the standardization of techniques across laboratories to enable multiple datasets to be compared and combined in order to obtain reliable and robust wide-scale patterns of diversity. A set of protocols using a core collection of simple sequence repeat (SSR) markers, reference lines and standard alleles, plus a common system of allele nomenclature, was adopted in the study of maize genetic diversity in a network of laboratories in Asia. Pair-wise allele comparisons of the reference lines, done to assess the general agreement between datasets from four laboratories, showed error rates (raw) ranging from 5.8% to 9.7%, which were reduced to less than 8% after adjustments of correctable errors, and further reduced to less than 6% after the exclusion of all markers with greater than 10% individual error rates. Overall, 45% of the total mismatches were due to frameshift errors, 39% to wrong allele size, 15% to failed amplification and 1% to "extra" alleles. Higher genetic similarity values of the reference lines were achieved using fewer markers with data of higher quality rather than with more markers of questionable quality. Cluster analysis of the merged datasets showed the lines from southern China to be highly diverse, falling into six of the seven clusters observed and all well represented by tester lines. The lines from Indonesia fell into five of six groups, with two main groups represented by tester lines. The CIMMYT lines developed for the Asian region showed a relatively narrow genetic base, falling in two out of seven and in three out of six clusters in China and Indonesia, respectively. In contrast to the case in southern China where 95% of the lines clustered separately from the CIMMYT lines, lines in the Indonesian breeding program show a closer relationship with the CIMMYT lines, reflecting a long history of germplasm exchange.


Subject(s)
Computational Biology/methods , Genetic Variation , Inbreeding , Zea mays/genetics , Alleles , Asia , Cluster Analysis , DNA Fingerprinting , Minisatellite Repeats/genetics , Research Design , Species Specificity
7.
J Biosci Bioeng ; 87(4): 519-24, 1999.
Article in English | MEDLINE | ID: mdl-16232508

ABSTRACT

A simple biodegradation system consisting of an air stripping tank and a bioreactor was proposed for the treatment of volatile organic chemicals in wastewater. Toluene was used as a model of volatile organic chemicals. An aqueous solution of toluene and a basic mineral medium were placed in the air stripping tank and bioreactor, respectively. Toluene was stripped by supplying compressed air into the stripping tank through a sparger, and the stripped toluene was degraded by Pseudomonas putida mt-2 (ATCC 33015) in the bioreactor under aerobic conditions. The effect of the air stripping rate on bacterial growth was examined. A quantitative relationship was found between the air flow rate in the air stripping tank (Qa) and the stripping rate constant. During cultivation, the bacterial cells grew by utilizing toluene as the sole carbon source, and reached their maximum cell concentration (Xm) at the stationary phase. Xm showed a gradual decrease with increase in Qa from 1.8 to 7.2 l/h, indicating a decrease in the rate of toluene degradation with increasing Qa. The Xm at Qa=1.8 l/h was the highest among the experiments under different values of Qa, which was almost twice that at Qa=7.2 l/h. Mathematical analysis taking the growth kinetics and mass transfer of toluene into consideration satisfactorily explained the system performance.

8.
Asia Pac J Clin Nutr ; 5(3): 138-40, 1996 Sep.
Article in English | MEDLINE | ID: mdl-24394568

ABSTRACT

Communication and information technologies are rapidly changing the way we learn, live, and relate to others. There are societal and direct personal consequences, along with the impact of communication as a process, with which we need to reckon. As in other domains of life and health, nutritional well-being may be profoundly affected, favourably or unfavourably, depending on how we manage the new technologies. It is opportune for nutrition scientists and practitioners to embrace proactively these developments.

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