Association of adiposity with risk of obstructive sleep apnea: a population-based study

BACKGROUND

Obesity is a crucial risk factor for obstructive sleep apnea (OSA), but the association between adiposity deposition and OSA risk has not reached a consistent conclusion. This study sought to reveal the association of multiple adiposity indicators with OSA risk.

METHODS

This cross-sectional study included 9,733 participants aged 35-74 years, recruited from an ongoing population-based cohort. OSA was assessed by the Berlin Questionnaire. Six adiposity indicators, including neck circumference (NC), body fat percentage (BF%), waist-to-hip ratio (WHR), visceral adiposity index (VAI), lipid accumulation product (LAP), and resting metabolic rate (RMR), were selected. Multivariate logistic regression models were used to examine the association of adiposity indicators with OSA risk.

RESULTS

One thousand six hundred twenty-six participants (16.71%) were classified into the OSA group. NC, BF%, WHR, VAI, LAP, and RMR were all positively associated with the risk of OSA after adjusting for confounders, regardless of age, sex, and history of dyslipidemia. Every 1-unit increment of NC, BF%, and VAI was associated with a 13%, 9%, and 14% increased risk of OSA, respectively; every 0.01-unit increment of WHR was associated with a 3% increased risk of OSA; every 10-unit increment of LAP and RMR was associated with 2% and 4% increased risk of OSA, respectively.

CONCLUSIONS

NC, BF%, WHR, VAI, LAP, and RMR were all independently and positively associated with OSA risk, regardless of age, sex, history of dyslipidemia, and menopausal status. Application of these new indicators could help to more comprehensively reflect and predict the risk of OSA in the general population.

[Anatomical and histological investigation of the area anterior to the anorectum passing through the levator hiatus]

Objective: To document the anatomical structure of the area anterior to the anorectum passing through the levator hiatus between the levator ani slings bilaterally. Methods: Three male hemipelvises were examined at the Laboratory of Clinical Applied Anatomy, Fujian Medical University. (1) The anatomical assessment was performed in three ways; namely, by abdominal followed by perineal dissection, by examining serial cross-sections, and by examining median sagittal sections. (2) The series was stained with hematoxylin and eosin to enable identification of nerves, vessels, and smooth and striated muscles. Results: (1) It was found that the rectourethralis muscle is closest to the deep transverse perineal muscle where the longitudinal muscle of the rectum extends into the posteroinferior area of the membranous urethra. The communicating branches of the neurovascular bundle (NVB) were identified at the posterior edge of the rectourethralis muscle on both sides. The rectum was found to be fixed to the membranous urethra through the rectourethral muscle, contributing to the anorectal angle of the anterior rectal wall. (2) Serial cross-sections from the anal to the oral side were examined. At the level of the external anal sphincter, the longitudinal muscle of the rectum was found to extend caudally and divide into two muscle bundles on the oral side of the external anal sphincter. One of these muscle bundles angled dorsally and caudally, forming the conjoined longitudinal muscle, which was found to insert into the intersphincteric space (between the internal and external anal sphincters). The other muscle bundle angled ventrally and caudally, filling the gap between the external anal sphincter and the bulbocavernosus muscle, forming the perineal body. At the level of the superficial transverse perineal muscle, this small muscle bundle headed laterally and intertwined with the longitudinal muscle in the region of the perineal body. At the level of the rectourethralis and deep transverse perineal muscle, the external urethral sphincter was found to occupy an almost completely circular space along the membranous part of the urethra. The dorsal part of the external urethral sphincter was found to be thin at the point of attachment of the rectourethralis muscle, the ventral part of the longitudinal muscle of the rectum. We identified a venous plexus from the NVB located close to the oral and ventral side of the deep transverse perineal muscle. Many vascular branches from the NVB were found to be penetrating the longitudinal muscle and the ventral part of rectourethralis muscle at the level of the apex of the prostate. The rectourethral muscle was wrapped ventrally around the membranous urethra and apex of the prostate. The boundary between the longitudinal muscle and prostate gradually became more distinct, being located at the anterior end of the transabdominal dissection plane. (3) Histological examination showed that the dorsal part of the external urethral sphincter (striated muscle) is thin adjacent to the striated muscle fibers from the deep transverse perineal muscle and the NVB dorsally and close by. The rectourethral muscle was found to fill the space created by the internal anal sphincter, deep transverse perineal muscle, and both levator ani muscles. Many tortuous vessels and tiny nerve fibers from the NVB were identified penetrating the muscle fibers of the deep transverse perineal and rectourethral muscles. The structure of the superficial transverse perineal muscle was typical of striated muscle. These findings were reconstructed three-dimensionally. Conclusions: In intersphincteric resection or abdominoperineal resection for very low rectal cancer, the anterior dissection plane behind Denonvilliers' fascia disappears at the level of the apex of the prostate. The prostate and both NVBs should be used as landmarks during transanal dissection of the non-surgical plane. The rectourethralis muscle should be divided near the rectum side unless tumor involvement is suspected. The superficial and deep transverse perineal muscles, as well as their supplied vessels and nerve fibers from the NVB. In addition, the cutting direction should be adjusted according to the anorectal angle to minimize urethral injury.

[Long-term efficacy of low-dose rituximab treatment in patients with primary membranous nephropathy]

Objective: To explore the long-term efficacy of low-dose rituximab (RTX) treatment in patients with primary membranous nephropathy (PMN). Methods: Patients with biopsy-proven PMN who received low-dose RTX as initial or second-line regimen from August 2018 to May 2020 in the Department of Nephrology, Tianjin Medical University General Hospital were respectively enrolled. The clinical parameters of patients were urinary protein>3.5 g/24 h, serum albumin<30 g/L and estimated glomerular filtration rate (eGFR)>20 ml·min^-1·(1.73 m²)^-1. The treatment response of patients with PMN was observed during follow-up, and the remission rate of patients with urinary protein<8 g/24 h or ≥8 g/24 h, anti-PLA2R antibody<150 RU/ml or ≥150 RU/ml, eGFR≥ 60 ml·min^-1·(1.73 m²)^-1 or<60 ml·min^-1·(1.73 m²)^-1 were analyzed, respectively. Results: A total of 40 patients were enrolled, including 26 males and 14 females, aged (53±15) years. There were 14 patients received RTX as initial treatment and 26 patients as second-line therapy. The total median dose of RTX in the first course was 800 (425, 1 075) mg. The overall remission rate at the 1st, 3rd, 6th, 12th and 24th months were 12.5% (5/40), 17.5% (7/40), 47.5% (19/40), 57.5% (23/40), 60% (24/40), respectively. The median overall response time was 6.0 (3.0, 7.5) months. Two cases relapsed. Patients with remission (n=24) had a higher level of baseline eGFR [(93.9±28.0) vs (62.4±28.1) ml·min^-1·(1.73 m²)^-1, P=0.001), and a lower level of both urinary protein [5.9 (5.0, 6.5) vs 11.7 (8.6, 15.5) g/24 h, P<0.001] and anti-PLA2R antibody level [73 (29, 132) vs 453 (182, 950) RU/ml, P=0.004] than those without remission (n=16) 24 month after treatment. There was no statistically significant difference in the remission rate between initial and second-line treatment (P=0.101). Moreover, patients had a higher remission rate in urinary protein<8 g/24 h group (21/26 vs 3/14, P<0.001), anti-PLA2R antibody<150 RU/ml group (16/19 vs 5/16, P=0.002) and eGFR ≥ 60 ml·min^-1·(1.73 m²)^-1 group (22/29 vs 2/11, P=0.003). Conclusions: Low-dose RTX treatment in PMN is effective during long-term follow-up, and has a lower recurrence rate. The results also suggest that it is more suitable for patients with baseline urinary protein<8 g/24 h, anti-PLA2R antibody<150 RU/ml and eGFR≥ 60 ml·min^-1·(1.73 m²)^-1.

[Anatomical observation and clinical significance of the prostatic part of neurovascular bundle in total mesorectal excision]

Objective: To observe the anatomical architecture of the prostatic part of the neurovascular bundle (NVB) in total mesorectal excision (TME). Methods: A descriptive cohort study and an anatomical observation study were carried out. A total of 38 male patients with rectal cancer who underwent TME in the Department of Colorectal Surgery at the affiliated Union hospital of Fujian Medical University between November 2013 and March 2015 were included. A total of 4 hemipelvis were examined at the Laboratory of Clinical Applied Anatomy, Fujian Medical University. The following outcomes were observed: 1) the clinical significance of bleeding of the prostatic part of NVB: surgical videos were reviewed and the incidence of bleeding was recorded. The urogenital function was assessed using the International Prostate Symptom Score (IPSS) and International Index of Erectile Function (IIEF) score. The correlation between prostatic part bleeding and postoperative urogenital function was evaluated. 2) anatomical observation: the vessels, nerve fibers, as well as their surrounding fatty tissue from the prostatic part were treated as a whole, namely, the fat pad of the prostatic part. The anatomical architecture of the prostatic part in the surgical videos was reviewed and interpreted with the cadaveric findings. Categorical variables were compared between groups using a Fisher exact probability. while continuous variables with skewed distribution were compared between groups using the Mann-Whiteny U test. Results: The median age of the included 38 patients was 57 years (range, 31-75), and the median tumor distance to the anal verge was 6 cm (range, 1-8). Of them, a total number of 21 (55.3%) patients had bleeding of the prostatic part of NVB (bleeding group), while the rest had not (17 cases, 44.7%, non-bleeding group). 1) the clinical significance of bleeding of the prostatic part of NVB. The urinary function significantly decreased in patients in the bleeding group according to IPSS score after the 3rd month and the 6rd month of the surgery [7 (0-16) vs. 2 (0-3), Z=-1.787, P=0.088; 2 (0-15) vs. 0 (0-2), Z=-2.270, P=0.028]. There was no difference regarding the IPSS score between the two groups after 1 year of the surgery (P>0.05). With a total of 23 patients with normal preoperative sexual activity included, 87.5% (7/8) of patients in the non-bleeding group can expect to return to their preoperative baseline, this incidence was significantly higher than that of only 40% (6/15) in the bleeding group (P=0.029). 2) anatomical observation: for cadaveric observation, the prostatic part of NVB was located in the narrow triangular space composed of anterolateral walls of the rectum, the posterolateral surface of the prostate and the medial surface of the levator ani musculature. The tiny vascular branches and nerve fibers from the prostatic part were hard to identify. The cavernosal nerves cannot reliably be distinguished from the neural supply to the prostate, rectum and levator ani. In the cross-section of levels of prostatic base and mid-prostate in cadaveric hemipelvis specimens, the boundary of the prostatic part fat pad was partly overlapped and merged with the boundary of the mesorectum. Intraoperative observation showed that the areas of overlap referred to the rectal branches from the prostatic part piercing the proper fascia to supply the mesorectum, which carried the largest tension and high risk of bleeding during circumferential dissection toward the perirectal plane. The ultrasonic scalpel was required to pre-coagulate the rectal branches at the point close to the proper fascia of the rectum to prevent bleeding. In the cross-section of the prostatic apex level, the prostatic part approached ventrally and its boundary was away from the boundary of the mesorectum. Conclusions: NVB prostatic part injury is one of the causes of urogenital dysfunction after TME. The nerve fibers from the prostatic part were tiny, and its functional zones cannot be distinguished during operation. Therein, the fat pad of the prostatic part should be protected as a whole. Understanding the morphology of the fat pad of the prostatic part provides invaluable surgical guidance to dissect this critical area. When dissecting around the anterolateral rectal wall, appropriate anti-traction tension should be maintained and the rectal branches from the prostatic part should be coagulated with an ultrasonic scalpel to prevent bleeding.

[Anatomical observation of the right retroperitoneal fascia and its clinical significance in complete mesocolic excision for right colon cancer]

Objective: To investigate the anatomic characteristics of the right retroperitoneal fascia and its surgical implementation while performing complete mesocolic excision (CME) for right colon cancer. Methods: A descriptive study was carried out. (1) Clinicopathological data and surgical videos of 17 non-consecutive patients undergoing laparoscopic right hemicolectomy (extended right hemicolectomy) with CME for right colon cancer at Department of Colorectal Surgery of Union Hospital, Fujian Medical University between January 2020 and October 2020 were retrospectively collected. The construction of right retroperitoneal fascia was observed from caudal dorsal direction and caudal ventral direction. (2) Three postoperative specimens from 3 cases undergoing laparoscopic right hemicolectomy with CME for right colon cancer in June 2020 were prospectively included to observe anatomy and examine histology. (3) Five abdominal cadaver specimens from the Department of Anatomy of Fujian Medical University were enrolled, including 3 males and 2 females. Anatomical observation and histological studies were performed from the cranial approach and the caudal dorsal approach. Masson staining was used to examine the histology. Results: (1) Surgical video observation: The typical structure of right retroperitoneal fascia could be observed in all the 17 patients. The fascia was a rigid barrier between the posterior space of the ascending colon and the anterior pancreaticoduodenal space behind the transverse colon. The right retroperitoneal fascia should be sharply cut to communicate between the two spaces to avoid entering the right mesocolon by mistake. The severed ventral stump of the right retroperitoneal fascia ran along the dorsal side of the right hemicolon to the lateral side, and the dorsal stump covered the level of the duodenum caudally, and continued to move downward, covering the surface of Gerota's fascia. (2) Observation of 3 surgical specimens: The dorsal side of the right mesocolon was smooth and intact, which could be anchored in the corresponding area of the lateral edge of the duodenum. The ventral stump of the right retroperitoneal fascia could be seen, which attached to the dorsal side of the right mesocolon semi-circularly. Masson staining observation: The ventral stump of the right retroperitoneal fascia ran cephalad, fused with the dorsal side of the right mesocolon tightly and curled. The caudal side of confluence and the dorsal side of the right mesocolon presented a bilobed structure. (3) Anatomy of 5 cadaveric specimens: The right retroperitoneal fascia was a thin fascia structure, which was a rigid barrier between the anterior pancreaticoduodenal space behind the transverse colon and the posterior space of the ascending colon. The ventral stump of the right retroperitoneal fascia (including the dorsal side of the right mesocolon), the dorsal stump of the right retroperitoneal fascia (including part of the duodenal wall) and the dorsal side of the right mesocolon were retrieved for histological examination. The ventral stump of the right retroperitoneal fascia fused with the dorsal side of the right mesocolon by the cephalic side, and the dorsal side of the right hemi-mesocolon on the fusion level by caudal side gradually separated into a double-layer loose fascial structure. The dorsal stump of the right retroperitoneal fascia covered the surface of the duodenum level, moved on from the ventral side to the surface of the prerenal fascia, and continued to the caudal side. Conclusions: The right retroperitoneal fascia is a rigid barrier between the anterior pancreaticoduodenal space behind the transverse colon and the posterior space of the ascending colon. The Toldt fascia formed by fusion with the dorsal lobe of the right colon travels to the edge of the descending and horizontal part of the duodenum and separates again. The right retroperitoneal fascia is attached to the edge of the duodenum, reversing and running on the surface of the prerenal fascia, while the dorsal lobe of the right colon runs in front of the pancreas and duodenum, and shifts to the pancreaticoduodenal fascia. During the operation, this fascia should be identified and cut to penetrate the anterior pancreaticoduodenal space behind the transverse colon and the posterior ascending colon space, which helps to ensure the integrity of the dorsal side of the right hemi-mesocolon.

[Establishment and validation of a new predictive equation with multiple risk factors for the development of cardiorenal syndrome type 1 in patients with acute myocardial infarction]

Objective: To investigate the independent risk factors of cardiorenal syndrome type 1 (CRS1) in patients with acute myocardial infarction (AMI) and to build a predictive equation for the development of CRS1 in these patients. Method: Consecutive inpatients with AMI, who hospitalized from January 2017 to December 2018 in the Hunan Provincial People's Hospital, were enrolled in this case-control study. Patients were divided into CRS1 group and non-CRS1 group according to the presence or absence of CRS1.The clinical data were collected through the electronic medical record system of Hunan Provincial People's Hospital. The matching process was conducted with a minimum-distance scoring method and a 1∶1 match between the CRS1 group and the no-CRS1 group, the propensity score was calculated through the logistic regression model. Factors with statistically significant differences in univariate analysis were included in the multivariate logistic regression model to analyze the risk factors of AMI patients with CRS1, then the independent risk factors were used to establish a predicting equation for CRS1 by logistic regression function for model building. Area under the curve (AUC) value and the best cut-off value of the combined predictors was determined according to the ROC curve. Python 3.8 software was used to perform 10-fold cross-validation on modeling samples. Results: A total of 942 patients were included, there were 113 cases in CRS1 group and 829 cases in non-CRS1 group. Ultimately, 99 CRS1 patients were successfully matched to 99 non-CRS1 patient using 1∶1 matching. After propensity score matching, the baseline age and sex along with heart rate, mean arterial pressure, percentage of people with a history of diabetes, hypertension, ST-segment elevation myocardial infarction, myocardial ischemia time, angiotensin converting enzyme inhibitors or angiotensin Ⅱ receptor blockers use, and β receptor blocker use were similar between the two groups(all P>0.05). The contrast agent dosage was also similar between the two groups (P=0.266). The peak cardiac troponin I (cTnI), N-terminal pro-brain natriuretic peptide(NT-proBNP), white blood cell count, base estimated glomerular filtration rate (eGFR), albumin and hemoglobin levels were statistically significant between the two groups (all P<0.05). Multivariate logistic regression analysis showed that decreased baseline eGFR, increased NT-proBNP, peak cTnI concentrations and white blood cell count were independent risk factors of CRS1 in AMI patients (all P<0.01).The predicting equation of the combined predictor was established by transforming the logistic model equation, L=0.031×cTnI+0.000 2×NT-proBNP-0.024×eGFR+0.254×white blood cell count, where L represented the combined predictor. ROC curve analysis indicated that the AUC of the peak cTnI, NT-proBNP, baseline eGFR, white blood cell count, and combined predictor were 0.76, 0.85, 0.79, 0.81, and 0.92 respectively (all P<0.05), and the cutoff value of combined predictor was 2.6. The AUC of ROC curve after the model's ten-fold cross validation was 0.89. Conclusions: Decreased baseline eGFR, increased NT-proBNP, peak cTnI concentrations and white blood cell count are the independent risk factors for CRS1 in AMI patients. The combined predictor equation based on the above 4 biomarkers presents a good predictive value for CRS1 in AMI patients.

[Anatomical observation of the left parietal peritoneum and its clinical significance in left retro-mesocolic space dissection]

Objective: To investigate the anatomic characteristics of the left parietal peritoneum and its surgical implementation while dissecting in left retro-mesocolic space. Methods: A descriptive case series research methods was used. (1) surgical videos of 35 patients who underwent laparoscopic radical resection (complete mobilization of splenic flexure) of colorectal cancer in Union Hospital of Fujian Medical University between January 2018 and December 2018 were reviewed; (2) four specimens after radical resection of rectal cancer performing in June 2020 were prospectively enrolled and reviewed; (3) five specimens of left parietal peritoneum from 5 cadaveric abdomen (3 males and 2 females) were enrolled and reviewed as well; Tissues of 3 unseparated regions, namely the root of the inferior mesenteric artery (IMA), the medial region and the lateral region (including kidney tissue), from above the 5 cadaveric abdominal specimens were selected to perform Masson staining and histopathological examination. Results: (1) Surgical video observation: "Staggered layer phenomenon" and typical left parietal peritoneum was found in 77.1% (27/35) of patients when the left retro-mesocolic space was separated from the lateral and central approaches. The left parietal peritoneum presented as a rigid fascia barrier between the lateral and central approaches, which was a translucent dense connective tissue fascia. After the splenic flexure were completely mobilized, the left parietal peritoneum stump continued to the cephalic side. (2) Observation of 4 surgical specimens: The dorsal side of the left mesocolon specimen was studied, and the left parietal peritoneum stump edge was identified. The outside of the stump edge was the left hemicolon dorsal layer, which was continuously downward to the rectal fascia propria. (3) Cadaveric abdominal specimens: The left retro-mesocolic space was separated through lateral and central approaches, and the rigid fascia barrier, essentially the left parietal peritoneum and Gerota fascia, was encountered. Cross-section view showed that the left parietal peritoneum could be further detached from the dorsal layer of the left mesocolon from the outside, but could not be further detached from the inside out. (4) Histological examination: There was no obvious fascia structure in the IMA root region, while outside the IMA root region, the left bundle of inferior mesenteric plexus penetrating Gerota fascia was observed. There were 4 layers of fascias in the medial region, including the ventral layer of the left mesocolon, the dorsal layer of the left mesocolon, left parietal peritoneum and Gerota fascia. Small vessels were observed between the dorsal layer of the left mesocolon and the left parietal peritoneum. In lateral region, renal tissue and renal fascia were observed. Three layers of fascia structures were observed clearly under high power field, including the dorsal layer of the left mesocolon, left parietal peritoneum, and Gerota fascia. Conclusions: The left parietal peritoneum is the anatomical basis of the "staggered layer phenomenon" from the lateral or central approaches during the separation of left retro-mesocolic space. The small vessels in the dissection plane are the anatomical basis of intraoperative microbleeding, which need pre-coagulation. The central part of Gerota fascia is penetrated by the branches of the inferior mesenteric plexus, which results in a relatively dense surgical plane. Thus, during the dissection through the central approach, it is easy to involve in wrong surgical plane by deeper dissection.

[Effects of ammonium pyrrolidine dithiocarbamate (PDTC) on osteopontin expression and autophagy in tubular cells in streptozotocin-induced diabetic nephropathy rat]

Objective: To investigate the effects of ammonium pyrrolidine dithiocarbamate (PDTC) on tubulointerstitial inflammatory molecules and autophagy in diabetic nephropathy (DN) rats. Methods: Twenty-four male Sprague-Dawley rats were assigned to DN group (n=6) and DN+ PDTC group (n=6, PDTC, ip, 100 mg·kg^-1·d^-1), all received streptozotocin (STZ) 60 mg/kg intraperitoneally, and the other 12 rats were randomly divided into control group (n=6) and PDTC group (n=6). At the end of 12 weeks, after serum creatine (Scr) and 24-hour urinary protein were determined, rats were sacrificed to determined the renal pathological damages and the changes of nuclear factor (NF)-κB p65, p62, osteopontin (OPN), microtubule associated protein 1 light chain 3 (LC3)-Ⅱ/LC3-Ⅰ, nuclear p-NF-κB p65 by immunohistological stainning and Western blot, and ultrastructural changes of autophagic process was observed by electron microscopy (EM). Results: Scr was similar among the four groups (P>0.05). The levels of urinary protein in DN group and DN + PDTC group were significantly higher than the other two groups (all P<0.01), but the level of urinary protein in DN + PDTC group was lower than that of DN group (P<0.05). DN + PDTC group had less tubulointerstitial damage compared with DN group (P<0.05). Among the four groups, expressions of p62, p65, OPN of tubulointerstitial area in DN group were significantly higher than that of the other groups (all P<0.05), and Western blot showed that DN+ PDTC group had less expressions of NF-κB p65, nuclear p-p65, OPN and more expresssion of LC3-Ⅱ/LC3-Ⅰ compared with DN group (all P<0.05), which were consistent with the decreased autophagic vacuoles and increased mitochondria dysfunction revealed by EM. Correlation analysis showed that renal LC3-Ⅱ/LC3-Ⅰ was negatively correlated the expressions of nuclear p-p65 and OPN (r=-0.45, P=0.02; r=-0.50, P=0.01), and p62 was positively correlated the expressions of nuclear p-p65 and OPN (r=0.33, P=0.01; r=0.41, P=0.01). Conclusion: Tubular NF-κB activation is closely related to autophagy dysfunction in DN rats, and PDTC may enhance autophagy activity in tubule cells by blocking NF-κB activity.

Development of diabetic nephropathy in nude mice

BACKGROUND

Immune dysfunction is very common in diabetes mellitus (DM). However, there is no evidence whether such immune dysfunction can influence the development of DM, especially the development of diabetic nephropathy (DN).

AIM

To investigate the influence of absence of T cells on DN.

MATERIALS AND METHODS

Balb/c nude mice and Balb/c wild-type nude (WT) mice were injected with streptozotocin (STZ). Serum tumor necrosis factor α (TNF-α), blood glucose, body weight, urine albumin/creatinine ratio and rate of kidney weight to body weight (KW/BW) were measured.

RESULTS

After modeling, there was no difference of blood glucose level between nude mice and WT mice except at week 2 (28.3 ± 4.9 mmol/l vs 23.1 ± 3.9 mmol/l, p<0.01). At week 4, the serum TNF- α level of nude mice got to 175.08 ± 46.03 pg/ml (p<0.05, compared with baseline level 80.19 ± 8.46 pg/ml), whereas the TNF- α levels of WT mice was stable. At week 4, the body weight of nude mice was lower than that of WT mice (14.7 ± 3.15 g vs 17.97 ± 2.85 g, p<0.05); the urine albumin/creatinine ratio (Alb/Cr) of nude mice was higher than that of WT mice (50.96 ± 5.57 mg/mmol vs 41.09 ± 5.79 mg/mmol, p<0.05); the kidney weight to body weight of nude mice was higher than that of WT mice (0.01352 ± 0.00163 vs 0.01173 ± 0.00131, p<0.05). Correlation analysis showed urine Alb/Cr positively correlated with serum TNF-α level at week 4 (r = 0.588, p<0.01). At week 4, the increase of type IV collagen in the glomeruli was more prominent in diabetic nude mice than in diabetic WT mice (p<0.05).

CONCLUSIONS

Absence of T cells in DM might influence the development of DN.

Diabetes mellitus and prostate cancer risk in Asian countries: a meta-analysis

BACKGROUND/AIMS

Diabetes mellitus (DM) is widely considered to be associated with risk of cancer, but studies investigating the association between DM and prostate cancer in Asian countries have reported inconsistent findings. We examined this association by conducting a detailed meta-analysis of studies published on the subject.

METHODS

Cohort or case-control studies were identified by searching Pubmed, Embase and Wanfang databases through May 30, 2012. Pooled relative risk (RR) with its corresponding 95% confidence interval (95% CI) were calculated using the random-effects model. Subgroup analyses were performed by the study type.

RESULTS

Finally, we identified 7 studies (four cohort studies and three case-control studies) with a total of 1,751,274 subjects from Asians. DM was associated with an increased risk of prostate cancer in Asians (unadjusted RR= 2.82, 95% CI 1.73-4.58, P < 0.001; adjusted RR= 1.31, 95% CI 1.12-1.54, P = 0.001). Subgroup analyses by study design further confirmed an obvious association.

CONCLUSION

Findings from this meta-analysis strongly support that diabetes is associated with an increased risk of prostate cancer in Asians.

Serum osteoprotegerin measurement for early diagnosis of chronic kidney disease-mineral and bone disorder

AIM

Chronic kidney disease-mineral and bone disorder (CKD-MBD) has been proposed to be the replacement of renal osteodystrophy by the Organization of Kidney Disease: Improving Global Outcomes since 2005 because the mineral disorder is not confined to the skeleton in CKD. Accordingly, laboratory and imaging tests have been emphasized for the clinical assessment of patients with CKD besides renal biopsy. The objective of the current study was to investigate whether osteoprotegerin (OPG) could be made a useful biomarker for early diagnosis of CKD-MBD.

METHODS

Sixty pre-dialysis patients with CKD 1-5 were enrolled in this study. The serum calcium, phosphorus, blood urea nitrogen, creatinine, alkaline phosphatase, Osteocalcin, Calcitonin, intact parathyroid hormone and OPG were measured. Bone mineral densities of the lumbar spine (L2-L4), femoral neck, Ward's triangle and trochanter were measured by dual-energy X-ray absorptiometry.

RESULTS

Among all measured serum bone metabolism indexes, the changing of serum OPG level happened at the earliest time (CKD 3) and its correlation coefficient with estimated glomerular filtration rate (eGFR) was also the highest (r = -0.601, P = 0.001). In the multivariable analysis that included sex, age and eGFR as controlling factors, the serum OPG correlated with the bone mineral density (BMD) of Ward's triangle (r = -0.390, P = 0.041).

CONCLUSION

Serum OPG may be a useful biomarker for early diagnosis of CKD-MBD.

Phase transition between nanostructures of titanate and titanium dioxides via simple wet-chemical reactions

Titanate nanofibers of various sizes and layered structure were prepared from inorganic titanium compounds by hydrothermal reactions. These fibers are different from "refractory" mineral substances because of their dimension, morphology, and significant large ratio of surface to volume, and, surprisingly, they are highly reactive. We found, for the first time, that phase transitions from the titanate nanostructures to TiO(2) polymorphs take place readily in simple wet-chemical processes at temperatures close to ambient temperature. In acidic aqueous dispersions, the fibers transform to anatase and rutile nanoparticles, respectively, but via different mechanisms. The titanate fibers prepared at lower hydrothermal temperatures transform to TiO(2) polymorphs at correspondingly lower temperatures because they are thinner, possess a larger surface area and more defects, and possess a less rigid crystal structure, resulting in lower stability. The transformations are reversible: in this case, the obtained TiO(2) nanocrystals reacted with concentrate NaOH solution, yielding hollow titanate nanotubes. Consequently, there are reversible transformation pathways for transitions between the titanates and the titanium dioxide polymorphs, via wet-chemical reactions at moderate temperatures. The significance of these findings arises because such transitions can be engineered to produce numerous delicate nanostructures under moderate conditions. To demonstrate the commercial application potential of these processes, we also report titanate and TiO(2) nanostructures synthesized directly from rutile minerals and industrial-grade rutiles by a new scheme of hydrometallurgical reactions.

Phase transition between nanostructures of titanate and titanium dioxides via simple wet-chemical reactions

Titanate nanofibers of various sizes and layered structure were prepared from inorganic titanium compounds by hydrothermal reactions. These fibers are different from "refractory" mineral substances because of their dimension, morphology, and significant large ratio of surface to volume, and, surprisingly, they are highly reactive. We found, for the first time, that phase transitions from the titanate nanostructures to TiO(2) polymorphs take place readily in simple wet-chemical processes at temperatures close to ambient temperature. In acidic aqueous dispersions, the fibers transform to anatase and rutile nanoparticles, respectively, but via different mechanisms. The titanate fibers prepared at lower hydrothermal temperatures transform to TiO(2) polymorphs at correspondingly lower temperatures because they are thinner, possess a larger surface area and more defects, and possess a less rigid crystal structure, resulting in lower stability. The transformations are reversible: in this case, the obtained TiO(2) nanocrystals reacted with concentrate NaOH solution, yielding hollow titanate nanotubes. Consequently, there are reversible transformation pathways for transitions between the titanates and the titanium dioxide polymorphs, via wet-chemical reactions at moderate temperatures. The significance of these findings arises because such transitions can be engineered to produce numerous delicate nanostructures under moderate conditions. To demonstrate the commercial application potential of these processes, we also report titanate and TiO(2) nanostructures synthesized directly from rutile minerals and industrial-grade rutiles by a new scheme of hydrometallurgical reactions.

Rotor-like ZnO by epitaxial growth under hydrothermal conditionsElectronic supplementary information (ESI) available: TEM images of the rod-like and rotor-like ZnO in the bright field and dark field. See http://www.rsc.org/suppdata/cc/b4/b403252g/

Rotor-like ZnO was grown from a mixture of rod-like ZnO powder and a saturated Zn(OH)(4)(2-) solution under moderate hydrothermal conditions at 100 degree C, in which the precursor rod-like ZnO crystal plane acts as a matrix core, and the branched nanorods showed fast epitaxial growth on the six directions around the prism core.

Why reversing the sequence of the alpha domain of human metallothionein-2 does not change its metal-binding and folding characteristics

A novel peptide, the backward reading sequence of human metallothionein-2 alpha domain, was synthesized and its chemical and spectroscopic properties analyzed. This folded retro-alpha domain was able to bind Cd(II) in identical stoichiometries with the chemically synthesized alpha domain of metallothionein-2. Nearly identical to the alpha domain, Cd-binding retro-alpha domain showed a characteristic ultraviolet absorption spectrum with a shoulder at 245-250 nm (due to cadmium-thiolate charge transfer), and the absorption shoulder was abolished by acidification [suggesting mercaptide bonding between Cd(II) and the cysteine residues]. Similar metal-binding capabilities between alpha domain and retro-alpha domain were observed also by pH titration and in the reaction with the sulfhydryl reagent 5,5'-dithiobis(2-nitrobenzoic acid). A two-state cooperativity of the metal-cluster formation was observed spectroscopically in the titration of the retro-alpha domain, indicating that the retro-protein is foldable. In contrast to other proteins, our results indicate that the reversion of the amino acid sequence for the alpha domain does not change its foldability and metal-binding capacity, suggesting that the order of its sequence is not critical to the formation of a critical metal-tetrathiolate nucleus. However, CD spectra of the Cd-binding alpha domain and retro-alpha domain showed that the reversal direction of the domain sequence backbone significantly affects the formation of structure even when it is foldable.

Multiple isoforms of metallothionein are expressed in the porcine liver

Isogenes are highly homologous to each other and are often difficult to ascertain, as has been the case with metallothionein, a metal-binding protein rich in cysteines. Conventional separation of metallothionein isoforms relied on ion exchange chromatography of the proteins, or screening for the sequences from gene libraries. In this study, a combination of RT-PCR and partial protein sequencing is used in the identification of metallothionein isogenes expressed in porcine liver. By this approach, we have identified expressed coding sequences which constitute 10 new isogenes. Of the four known groups of metallothioneins (MT), phylogenetic analyses place these pig isogenes in the MT-1 group, except two which are identified as being closely related to MT-2, and none in groups 3 and 4. The isogenes are thus namedpMT-1a to -1g, andpMT-2a and -2b. While each of the isogene sequences is unique, two isogenes,pMT-1e1 andpMT-1e2, share an identical amino acid sequence, differing only in specific codons. Two others,pMT-1b andpMT-1g, have a cysteine substituted by arginine, the first such sequence ever detected in MT.pMT-2a andpMT-2b are closely aligned with the MT-2 group of vertebrates, in spite of the absence of a characteristic acidic amino acid at position 10 or 11, common in other mammalian metallothioneins.