Alteration of the Intestinal Environment by Lubiprostone Is Associated with Amelioration of Adenine-Induced CKD

The accumulation of uremic toxins is involved in the progression of CKD. Various uremic toxins are derived from gut microbiota, and an imbalance of gut microbiota or dysbiosis is related to renal failure. However, the pathophysiologic mechanisms underlying the relationship between the gut microbiota and renal failure are still obscure. Using an adenine-induced renal failure mouse model, we evaluated the effects of the ClC-2 chloride channel activator lubiprostone (commonly used for the treatment of constipation) on CKD. Oral administration of lubiprostone (500 µg/kg per day) changed the fecal and intestinal properties in mice with renal failure. Additionally, lubiprostone treatment reduced the elevated BUN and protected against tubulointerstitial damage, renal fibrosis, and inflammation. Gut microbiome analysis of 16S rRNA genes in the renal failure mice showed that lubiprostone treatment altered their microbial composition, especially the recovery of the levels of the Lactobacillaceae family and Prevotella genus, which were significantly reduced in the renal failure mice. Furthermore, capillary electrophoresis–mass spectrometry-based metabolome analysis showed that lubiprostone treatment decreased the plasma level of uremic toxins, such as indoxyl sulfate and hippurate, which are derived from gut microbiota, and a more recently discovered uremic toxin, trans-aconitate. These results suggest that lubiprostone ameliorates the progression of CKD and the accumulation of uremic toxins by improving the gut microbiota and intestinal environment.     

Factors associated with the stability of titanium screws placed in the posterior region for orthodontic anchorage.

Recently, implant anchors such as titanium screws have been used for absolute anchorage during edgewise treatment. However, there have been few human studies reporting on the stability of implant anchors placed in the posterior region. The purpose of this study was to examine the success rates and to find the factors associated with the stability of titanium screws placed into the buccal alveolar bone of the posterior region. Fifty-one patients with malocclusions, 134 titanium screws of 3 types, and 17 miniplates were retrospectively examined in relation to clinical characteristics. The 1-year success rate of screws with 1.0-mm diameter was significantly less than that of other screws with 1.5-mm or 2.3-mm diameter or than that of miniplates. Flap surgery was associated with the patient's discomfort. A high mandibular plane angle and inflammation of peri-implant tissue after implantation were risk factors for mobility of screws. However, we could not detect a significant association between the success rate and the following variables: screw length, kind of placement surgery, immediate loading, location of implantation, age, gender, crowding of teeth, anteroposterior jaw base relationship, controlled periodontitis, and temporomandibular disorder symptoms. We concluded that the diameter of a screw of 1.0 mm or less, inflammation of the peri-implant tissue, and a high mandibular plane angle (ie, thin cortical bone), were associated with the mobility (ie, failure) of the titanium screw placed into the buccal alveolar bone of the posterior region for orthodontic anchorage.     

Mandibular stability after SSRO with or without postoperative maxillo-mandibular fixation for class III malocclusion

Objective

The objective of this study was to assess the usefulness of maxillo-mandibular fixation (MMF) from a viewpoint of skeletal and occlusal stability and to investigate the complications after surgery with and without MMF.

Materials and methods

Twenty-seven patients who underwent surgical correction of class III malocclusion were analyzed. The surgical procedure in all cases consisted of a bilateral sagittal splitting ramus osteotomy (SSRO). The segments were then fixed rigidly with titanium screws. A postoperative MMF was performed in 13 patients within 1 day of the SSRO. The MMF lasted for 1 week. The other 14 patients were free to move their jaw on the day of the surgery and received occlusal guidance with elastics starting from the third postoperative day. Cephalograms were taken preoperatively, at 1 day postoperatively and at 1, 3, 6, 12, and 24 months after surgery. Skeletal and occlusal stabilities along with postoperative complications were then assessed.

Results

Discomfort of the pharynx and postoperative pain was more severe in the MMF group. Even without MMF, occlusion was guided to the ideal position by an average of 5.3 days after surgery. Occlusal and skeletal stability was satisfactory in both groups, and there was no correlation between the surgical results and postoperative MMF.

Conclusion

MMF may not be necessary after a rigid fixation SSRO, considering the risks of airway problems.     

Effect of ENU (ethylnitrosourea) mutagenesis in cleft lip and/or palate pathogenesis in mice

Cleft lip and/or palate (CL/P) are caused by many factors. The aim of this study was to investigate the effects of genetic point mutations in CL/P pathogenesis. ICR and AJ strain mice were used. Ethylnitrosourea (ENU) was injected into 10-week-old male mice (G0) intraperitoneally at a dose of 250 mg/kg. The males were bred with two untreated virgin females of the same strain on day 100 after injection. The uterine contents (G1) of one female were examined on day 18.5 of pregnancy. From the other female, the offspring were delivered naturally, and F3 mice (G3) were also examined in the same way. In ICR strain mice, cleft palate only (CPO) was increased in both the G1 and G3. The frequency was significantly higher in the G3 than the G1 generation. Cleft lip was not observed. In AJ strain mice, CL/P increased in both the G1 and G3. In the G3, the frequency of CPO was increased significantly. Genes related to CPO may be recessive in phenotype. CPO and cleft lip differ from a genetic viewpoint. Point mutations play a significant role in cleft lip and palate.     

Application of high resolution microfocus X-ray CT for the observation of human tooth

The calcification degree of extracted human teeth was observed by using high resolution microfocus X-ray CT. As samples, upper and lower first premolars extracted from a 21-year-old female were used. The computed tomograms were produced by high resolution microfocus X-ray CT with a open vacuum X-ray source, rotating sample stage, and image sensor. The distinction between enamel and dentin was very clear, and the shape of the pulp cavity was also clearly identified. The secondary dentin was visible in the circumpulpal dentin. The color map displays showed the heterogeneity of the calcification degree not only in the dentin but also in the enamel. The enamel was divided into three layers according to the calcification degree. High resolution microfocus X-ray CT was very useful for the observation of the internal structure of human teeth without destroying the samples.