Prevalence and risk factors of urinary stones in Koreans.

To estimate the prevalence of urinary stone disease in Koreans, and to determine the inter-relationships between urinary stone disease and various epidemiological factors, 1,521 controls and 1,177 cases with urinary stones were evaluated. Of special interest in this study were: 1) proportion of past urinary stone history among controls; 1.9% 2) the point prevalence rate of urinary stones among controls; 0.2% 3) the recurrence rate of urinary stones (the proportion of past history of urinary stone) among cases; 56.8% 4) high incidences (76.3%) in the thirties to the fifties among cases 5) the risk factors for urolithogenesis; obesity [higher than 25 of BMI (body mass index, weight/height2)], more than 10 year-experience as a production worker, past stone history, familial stone history, low physical activity (< 2,000 Kcal/day), and low intake of fruit. However, the well-known risk factors for urinary stones; over intake of meat or fish and milk or dairy products, perspiration, amount and kind of drinking water, and stress unexpectedly were not significantly different between the controls and the cases.     

Dlk1 in normal and abnormal hematopoiesis.

Dlk1 (Pref-1) is a transmembrane and secreted protein, which is a member of the epidermal growth factor-like family, homologous to Notch/Delta/Serrate. We have found by real-time RT-PCR that Dlk1 mRNA levels were high in CD34(+) cells in 10 of 12 MDS samples compared with CD34(+) cells from 11 normals. Also, Dlk1 mRNA was elevated in mononuclear, low density bone marrow cells from 11/38 MDS patients, 5/11 AML M6 and 2/4 AML M7 samples. Furthermore, 5/6 erythroleukemia and 2/2 megakaryocytic leukemia cell lines highly expressed Dlk1 mRNA. Levels of Dlk1 mRNA markedly increased during megakaryocytic differentiation of both CMK megakaryoblasts as well as normal CD34(+) hematopoietic stem cells. High serum levels of Dlk1 occurred in RA (4/10) and essential thrombocythemia (2/10) patients. Functional studies showed that forced expression of Dlk1 enhanced proliferation of K562 cells growing in 1% fetal bovine serum. Analysis of hematopoiesis of Dlk1 knockout mice suggested that Dlk1 contributed to granulocyte, megakaryocyte and B-cell clonogenic growth and was needed for generation of splenic B-cells. In summary, Dlk1 is overexpressed in selected samples of MDS (especially RA and RAEB) and AML (particularly M6, M7), and it appears to be associated with normal development of megakaryocytes and B cells.     

Use of the tail moment of the lymphocytes to evaluate DNA damage in human biomonitoring studies.

The Comet assay has gained increasing popularity for use in human biomonitoring or epidemiologic studies; however, one of the shortcomings of the Comet assay is a lack of agreement on a single appropriate Comet parameter that is capable of adequately describing observed DNA damages. Among the tail parameters of Comet features, the most frequently used are the tail moments (both the Olive tail moment and the extent tail moment), the tail DNA, and the tail length. Some studies comparing Comet parameters have been found in cell toxicity research, but there are few comparative studies that use human biomonitoring or epidemiologic data. In this study, we evaluate those four tail parameters in both high and low DNA damaged cells with the use of epidemiologic data. To do this, a new graphical approach, the so-called quantile dispersion graphs (QDGs) are used. In a comparison of an exposed group and a control group, either the tail moment or tail DNA is preferable to the tail length. With respect to providing smaller variability in quantiles for the amount of DNA damage, however, the tail moment is the preferred parameter for both groups. Moreover, the tail moment provides the most stable estimates for DNA damage because it has a larger degree of uniformity in quantile dispersions. To study high degrees of damage from toxic exposure using B cells or G cells, however, the tail DNA showed more significant discrepancies than the other parameters, in terms of both the mean differences and the graphical differences between the two groups. In view of this result, it is suggested that both the tail moment and the tail DNA be presented as tail parameters in human biomonitoring studies.     

Disease severity impacts the relationship of apelin with arterial function in patients with rheumatoid arthritis

Apelin can improve arterial function by enhancing the expression of endothelial nitric oxide synthase but this effect depends markedly on endothelial integrity. We hypothesized that inflammation influences the potential impact of apelin on arterial function in rheumatoid arthritis (RA). We assessed the associations of apelin concentrations with arterial stiffness (pulse wave velocity), wave reflection (augmentation index, reflected wave pressure, and reflection magnitude), and pressure pulsatility (central systolic pressure (CSP), central pulse pressure (CPP), peripheral pulse pressure (PPP), pulse pressure amplification (PPamp), and forward wave pressure (Pf)) among 170 RA patients without cardiovascular disease. In multivariable regression models, apelin concentrations were not independently associated with arterial function measures (p?≥?0.15) in all patients. Inflammation markers were not consistently associated with apelin levels but joint deformity counts, Disease Activity Score in 28 joints (DAS28), and erythrocyte sedimentation rate (ESR) impacted apelin-pressure pulsatility relations (interaction p?≤?0.05). In stratified analysis, apelin was associated with CSP (partial r?=???0.33, p?=?0.01), CPP (partial r?=???0.26, p?=?0.04), PPamp (partial r?=?0.27, p?=?0.03), and Pf (partial r?=???0.33, p?=?0.01) in patients without but not with joint deformities; apelin was related to CSP (partial r?=???0.24, p?=?0.05) in those with a DAS28 joint <?2.8 (median value) (partial r?=???0.24, p?=?0.05) but not ≥?2.8, and to CSP (partial r?=???0.36, p?=?0.003) in those with an erythrocyte sedimentation rate <?13 mm/h (median value) but not ≥?13 mm/h. Apelin is associated with reduced pressure pulsatility in RA patients without but not with a high inflammatory burden. A loss of apelin protective effects on arterial function may contribute to the link between RA severity and cardiovascular risk.     

The effect of calcium ion concentration on the bone response to oxidized titanium implants

Aim: To investigate the effect of calcium concentration on the bone tissue response to Ca‐incorporated titanium implants Materials and methods: Two titanium surfaces containing 4.2% and 6.6% calcium were prepared using the micro‐arc oxidation process. The implants were inserted in the tibia of nine New Zealand White rabbits. After 6 weeks of healing, the bone response to the implants was quantitatively compared by biomechanical and histomorphometrical measurements. Results: Ca 4.2% and Ca 6.6% containing implants revealed no distinctive differences in their qualitative surface chemistry; chemical bonding state of Ca in titanium oxide was mainly calcium titanates. No significant differences were observed between two implants in peak removal torque and shear strength comparisons (P>0.05). Histomorphometrical analyses presented no significant differences in bone–metal contact, bone area and newly formed bone measurements between two implants (P>0.05). Conclusions: From biomechanical and histomorphometrical measurements, the two calcium concentrations in this study did not differ significantly with respect to their influence on the bone tissue response. This similar bone response in rabbit tibiae may be explained by the similarity of the qualitative Ca chemistry in titanium surfaces.     

In-feed antibiotic effects on the swine intestinal microbiome

Antibiotics have been administered to agricultural animals for disease treatment, disease prevention, and growth promotion for over 50 y. The impact of such antibiotic use on the treatment of human diseases is hotly debated. We raised pigs in a highly controlled environment, with one portion of the littermates receiving a diet containing performance-enhancing antibiotics [chlortetracycline, sulfamethazine, and penicillin (known as ASP250)] and the other portion receiving the same diet but without the antibiotics. We used phylogenetic, metagenomic, and quantitative PCR-based approaches to address the impact of antibiotics on the swine gut microbiota. Bacterial phylotypes shifted after 14 d of antibiotic treatment, with the medicated pigs showing an increase in Proteobacteria (1-11%) compared with nonmedicated pigs at the same time point. This shift was driven by an increase in Escherichia coli populations. Analysis of the metagenomes showed that microbial functional genes relating to energy production and conversion were increased in the antibiotic-fed pigs. The results also indicate that antibiotic resistance genes increased in abundance and diversity in the medicated swine microbiome despite a high background of resistance genes in nonmedicated swine. Some enriched genes, such as aminoglycoside O-phosphotransferases, confer resistance to antibiotics that were not administered in this study, demonstrating the potential for indirect selection of resistance to classes of antibiotics not fed. The collateral effects of feeding subtherapeutic doses of antibiotics to agricultural animals are apparent and must be considered in cost-benefit analyses.