Characteristics of the Gut Microbiome of Healthy Young Male Soldiers in South Korea: The Effects of Smoking

Background/Aims@#South Korean soldiers are exposed to similar environmental factors. In this study, we sought to evaluate the gut microbiome of healthy young male soldiers (HYMS) and to identify the primary factors influencing the microbiome composition. @*Methods@#We prospectively collected stool from 100 HYMS and performed next-generation sequencing of the 16S rRNA genes of fecal bacteria. Clinical data, including data relating to the diet, smoking, drinking, and exercise, were collected. @*Results@#The relative abundances of the bacterial phyla Firmicutes, Actinobacteria, Bacteroidetes, and Proteobacteria were 72.3%, 14.5%, 8.9%, and 4.0%, respectively. Fifteen species, most of which belonged to Firmicutes (87%), were detected in all examined subjects. Using cluster analysis, we found that the subjects could be divided into the two enterotypes based on the gut microbiome bacterial composition. Compared with enterotype 2 subjects, subjects classified as enterotype 1 tended to be characterized by higher frequencies of potentially harmful lifestyle habits (current smoker: 55.6% vs 36.6%, p=0.222; heavy drinker: 16.7% vs 3.7%, p=0.120; insufficient physical activity: 27.8% vs 14.6%, p=0.318). We identified a significant difference in the microbiome compositions of current and noncurrent smokers (p=0.008); the former differed from the latter mainly in a relatively lower abundance of Bifidobacterium species and a higher abundance of Negativicutes. @*Conclusions@#A high abundance of Actinobacteria and low abundance of Bacteroidetes

Lactobacillus attenuates progression of nonalcoholic fatty liver disease by lowering cholesterol and steatosis

Background/Aims@#Nonalcoholic fatty liver disease (NAFLD) is closely related to gut-microbiome. There is a paucity of research on which strains of gut microbiota affect the progression of NAFLD. This study explored the NAFLD-associated microbiome in humans and the role of Lactobacillus in the progression of NAFLD in mice. @*Methods@#The gut microbiome was analyzed via next-generation sequencing in healthy people (n=37) and NAFLD patients with elevated liver enzymes (n=57). Six-week-old male C57BL/6J mice were separated into six groups (n=10 per group; normal, Western, and four Western diet + strains [109 colony-forming units/g for 8 weeks; L. acidophilus, L. fermentum, L. paracasei, and L. plantarum]). Liver/body weight ratio, liver pathology, serum analysis, and metagenomics in the mice were examined. @*Results@#Compared to healthy subjects (1.6±4.3), NAFLD patients showed an elevated Firmicutes/Bacteroidetes ratio (25.0±29.0) and a reduced composition of Akkermansia and L. murinus (P<0.05). In the animal experiment, L. acidophilus group was associated with a significant reduction in liver/body weight ratio (5.5±0.4) compared to the Western group (6.2±0.6) (P<0.05). L. acidophilus (41.0±8.6), L. fermentum (44.3±12.6), and L. plantarum (39.0±7.6) groups showed decreased cholesterol levels compared to the Western group (85.7±8.6) (P<0.05). In comparison of steatosis, L. acidophilus (1.9±0.6), L. plantarum (2.4±0.7), and L. paracasei (2.0±0.9) groups showed significant improvement of steatosis compared to the Western group (2.6±0.5) (P<0.05). @*Conclusions@#Ingestion of Lactobacillus, such as L. acidophilus, L. fermentum, and L. plantarum, ameliorates the progression of nonalcoholic steatosis by lowering cholesterol. The use of Lactobacillus can be considered as a useful strategy for the treatment of NAFLD.

Sex Differences in Gut Microbiota

Study on the 6 MV Photon Beam Characteristics and Analysis Method from Medical Linear Accelerators Using Geant4 Medical Linac2 Example / 의학물리

In this study, Geant4 based Monte Carlo simulations were carried out for medical linear accelerator. Modified Medical Linac2 toolkit was used for calculation. The energy spectrum, most probable energy and the photon mean energy compared with the published results using the EGS4 code. The results well agreed with published results. The calculated results of photon fluence, energy fluence and mean energy according to the radius from the centre of the beam were analyzed. Monte Carlo simulation using Medical Linac2 code is considered to be useful for analysis of medical linear accelerator. Because the calculated results varies depending on Physics List model for same head structure. It it important to choose the right model for research purpose. Monte Carlo simulation using GEANT4 Medical Linac2 is a valuable for any novice to adopt this code to the study related to 6 MV photon fluence from medical linear accelerator.

Moxifloxacin Ameliorates Oleic Acid-induced Acute Lung Injury by Modulation of Neutrophilic Oxidative Stress in Rats / 결핵및호흡기질환

BACKGROUND: Based on the known immunoregulatory functions of moxifloxacin on phagocytes, the therapeutic effect of moxifloxacin on oleic acid (OA)-induced acute lung injury (ALI) was investigated. METHODS: Moxifloxacin (10 mg/kg) was given to male Sprague-Dawley rats that had been given oleic acid (OA, 30 microliter) intravenously. Five hours after OA injection, parameters demonstrating ALI were assessed to measure the effects of moxifloxacin on acute lung injury. RESULTS: The pathological findings of OA-induced ALI's was diminished by moxifloxacin. Through ultrastructural and CeCl3 EM histochemistry, moxifloxacin was confirmed to be effective in decreasing oxidative stress in the lung as well. Indices of ALI, such as lung weight/body weight ratio, protein content in bronchoalveolar lavage fluid, and lung myeloperoxidase were decreased by moxifloxacin. In diaminobenzidine immunohistochemistry, fluorescent immunohistochemistry, and Western blotting of the lung, moxifloxacin had decreased the enhanced expression of secretory phospholipase A2 (sPLA2) by OA. CONCLUSION: We concluded that moxifloxacin was effective in lessening acute inflammatory pulmonary edema caused by OA, by inhibiting the neutrophilic respiratory burst, which was initiated by the activation of sPLA2.

Role of the PLA2-Activated Neutrophilic Oxidative Stress in Oleic Acid-Induced Acute Lung Injury / 결핵및호흡기질환

BACKGROUND: The underlying pathogenesis of fat embolism-induced acute lung injury (ALI) has not been elucidated. In the present study, the pathogenesis of fat embolism-induced ALI was probed in association with neutrophilic oxidative stress in oleic acid (OA)-induced ALI of S-D rats. METHODS: OA was injected intravenously to provoke ALI in experimental rats. Five hours later, indices of ALI were measured to confirm the role of the neutrophilic respiratory burst. The effect of an inhibition of phospholipase A2 (PLA2) was also evaluated. RESULTS: The accumulation of neutrophils in the lung due to OA caused increased neutrophilic oxidative stress in lung, which was ameliorated by mepacrine. What were the results from inhibition of PLA2. CONCLUSION: Excess neutrophilic oxidative stress contributes to OA-induced ALI, which is lessened by the inhibition of PLA2.

Effect of the combined use of bone morphogenetic protein and platelet-derived growth factor on bone formation in nude mouse / 대한치주과학회지

Bone morphogenetic protein(BMP) and platelet-derived growth factor(PDGF) have been demonstrated tostimulate bone formation when applied locally in vivo. To explore whether or not the combined use of BMP and PDGF could have promotive effect and synergic interac- tion on bone formation in vivo, bone marrow mesenchymal stem cells were treated with BMP-2, PDGF-BB, or BMP-2 plus PDGF-BB, and then these cells were injected into the subcutaneous space on the dorsum of nude mice. The bone formation was evaluated after 12 weeks. Histomorphometric analysis demonstrated that the subcutaneous nodules formed in nude mice contained 25.3% newly formed bone in the BMP-2 treated cells, 14.4% newly formed bone in the PDGF-BB treated cells, and 8.9% newly formed bone in the BMP-2 plus PDGF-BB treated cells. The results showed that the combination of BMP-2 and PDGF-BB had neither a promotive effect nor synergic interact on bone formation in vivo.

The effects of irradiation and hyperbaric oxygen therapy on microvascular anastomosis

Malignant tumors of the head and neck frequently require treatment with both radiotherapy and surgery. Reconstruction of the defect in previously irradiated field is a challenge to surgeon, who must produce both a functional and an esthetic result. Hyperbaric oxygen therapy(HBO) has been used in an attempt to reduce the deleterious effects of radiation. But the issue of whether prior irradiation and HBO of the recipient site of a free flap affects the result of reconstruction continues to generate controversy. So, the effects of irradiation and hypergbaric oxygen therapy on microvascular anastomosis was evaluated in an experimental study in femoral vessels of rats. The experimental groups were divided into 3 groups, contorol group, irradiation group, and irradiation and HBO group. Preoperative irradiation was delivered in the left groin field with single dose corresponding 2,000cGy and total 48 hours of HBO was given 100% oxygen at 2.4 atmosphere for 4 weeks. The femoral vessels of 60 rats were anastomosed after irradiation and HBO treatment. Three days, 1 week, 2 weeks and 4 weeks after surgery, the femoral vessels were evaluated for patency and histopathologic changes. There was no notable effect of irradiation on patency of femoral vessels in rats and the radiation effects were obvious on histological examination which showed the sloughing of the endothelial cells, subintimal hyperplasia and fibrosis on the media and adventitia of femoral arteries. The histologic changes of the femoral veins were mild and not typical. But the effects of hyperbaric oxygen therapy after irradiation was seen not marked difference in irradiation group.