Derivation and validation of a novel preoperative risk prediction model for surgical site infection in pancreaticoduodenectomy and comparison of preoperative antibiotics with different risk stratifications in retrospective cohort

BACKGROUND

Surgical site infections (SSIs) are common postoperative complications of pancreaticoduodenectomy.

AIM

To develop a model for preoperative identification of the risk of SSI that may improve outcomes and guide preoperative antibiotics.

METHODS

The prediction model was built by meta-analysis. After literature search and inclusion, data extraction, and quantitative synthesis, the prediction model was established based on the pooled odds ratio of predictors. A single-centre retrospective cohort was the validation cohort. Receiver operating characteristic curves and area under the curve were used to assess the model's ability. We also created a decision curve and a calibration plot to assess the nomogram. The effects of prophylactic antibiotics on SSI were compared between groups by multivariable logistic regression with different risk stratifications.

FINDINGS

Twenty-eight studies were included in the meta-analysis, 17 studies in the derivation cohort. Age, male gender, body mass index, pancreatic duct diameter, high-risk diagnosis, and preoperative biliary drainage were selected to build the prediction model. The model was validated in an external cohort. The cut-off value was 3.5 and area under the curve (AUC) was 0.76 in open pancreaticoduodenectomy (OPD). In laparoscopic pancreaticoduodenectomy, the cut-off value was 4.5 and AUC was 0.69. Decision curve and calibration plot showed good usability of the model, especially in OPD. Multivariable logistic regression did not indicate differences between broad- and narrow-spectrum antibiotics for SSI in different risk stratifications.

CONCLUSION

The model can identify patients with a high risk of SSI preoperatively. The choice of prophylactic antibiotics under different risk stratifications should be investigated further.

Circ_0124055 promotes the progression of thyroid cancer cells through the miR-486-3p/MTA1 axis

BACKGROUND

Thyroid cancer is one of the malignancy cancers. CircRNA, a non-coding RNA, plays an important role in the development of cancer. The relationship and roles of circ_0124055, miR-486-3p and MTA1 in thyroid cancer have not been reported.

METHODS

Real-time quantitative polymerase chain reaction (RT-qPCR) was performed to analyze the RNA levels of circ_0124055, miR-486-3p and MTA1. Western blot was conducted to analyze the protein levels of MTA1, Epithelial cadherin (E-cadherin) and Neuro cadherin (N-cadherin). Subcellular localization assay was used to analyze circ_0124055 location in thyroid cancer cells. Colony formation assay and 5-Ethynyl-2'-deoxyuridine (EdU) assay were carried out to analyze cell proliferation. Cell migration and invasion were analyzed by wound-healing assay and transwell assay. Flow cytometry assay was performed to investigate cell apoptosis. Dual-luciferase reporter assay and RIP assay were employed to analyze the interactions among circ_0124055, miR-486-3p and MTA1. Immunohistochemical (IHC) assay was performed to assess the expression of Ki67, MTA1 and E-cadherin in tumor tissues. Thyroid cancer tumor growth in vivo was evaluated by tumor xenograft mouse model assay.

RESULTS

The expression of circ_0124055 was up-regulated in tumor tissues and cells. Knockdown of circ_0124055 could inhibit thyroid cancer cell proliferation, migration and invasion and promote cell apoptosis, accompanied by the dysregulation of E-cadherin and N-cadherin expression. Circ_0124055 could target miR-486-3p, and miR-486-3p could target MTA1. MiR-486-3p inhibitor could restore the effect of circ_0124055 knockdown in the progression of thyroid cancer. Moreover, MTA1 overexpression weakened the inhibitory effects of miR-486-3p mimics on the progression of thyroid cancer. Further, circ_0124055 could influence tumor growth in vivo.

CONCLUSION

Circ_0124055 promoted the progression of thyroid cancer cells through the miR-486-3p /MTA1 axis.

Menopausal hormone therapy: what are the problems in the perception of Chinese physicians?

OBJECTIVE

This study aimed to investigate Chinese physicians' perception and attitudes toward menopausal hormone therapy (MHT).

METHODS

This nationwide online survey was conducted in China. Physicians registered in the WeChat groups of the Gynecological Endocrinology Committee of China's Maternal and Child Health Care Association received a message invitation to complete this anonymous online survey from April 2020 to July 2020. Physicians' knowledge of and attitudes toward MHT were surveyed.

RESULTS

In total, 4672 questionnaires were submitted; only completed questionnaires could be submitted. The message was sent to 6021 doctors, so the response rate was 77.6%. Overall, 77.9-92.9% of physicians knew the common indications and contraindications to MHT. Additionally, 90.6%, 85.4%, 80.7% and 37.5% of physicians thought that MHT would increase the risk of venous thrombosis, breast cancer, endometrial cancer and weight gain, respectively. In total, 58.1% of the physicians mistakenly believed that a sex hormone test was one of the necessary examinations to reassess MHT prescription during follow-up visits. We found that 68.5% of physicians would consider using MHT themselves or recommend MHT to their partners in the future, and 11.4% were currently using MHT.

CONCLUSIONS

Most Chinese physicians have basic knowledge of MHT. Their misunderstandings about MHT mainly centered on the risks of endometrial cancer, weight gain and the necessary examinations during follow-up visits. These misunderstandings need to be clarified in future professional training programs.

Long non-coding RNA ZFAS1 regulates NOB1 expression through interacting with miR-646 and promotes tumorigenesis in osteosarcoma

OBJECTIVE

Zinc finger antisense 1 (ZFAS1), a newly identified lncRNA, is aberrantly regulated in various cancers including osteosarcoma (OS). However, the underlying molecular mechanisms of ZFAS1 in OS remain to be elucidated.

MATERIALS AND METHODS

We used transfection, luciferase report assay, quantitative Real Time-Polymerase Chain Reaction (qRT-PCR), colony formation assay, transwell migration, invasion assays, and Western blot to determine the potential mechanisms.

RESULTS

Our study showed that ZFAS1 was up-regulated in OS cells and promoted the colony formation, migration, and invasion of OS cells via activating the MAPK signaling pathway. Furthermore, the experimental results indicated that miR-646 was a target of ZFAS1 and there was a negative relationship between ZFAS1 and miR-646 expression. Additionally, we found that ZFAS1 in OS cells up-regulated the expression of NOB1 through sponging miR-646, finally facilitating the growth of the OS cells.

CONCLUSIONS

These results demonstrated that ZFAS1/miR-646/NOB1 axis might play an important role in the development of OS, and ZFAS1 and miR-646 can be considered as potential biomarkers for the diagnosis and treatment of OS.

Crystal Structure and Immunogenicity of the DS-Cav1-Stabilized Fusion Glycoprotein From Respiratory Syncytial Virus Subtype B

Background:

Respiratory syncytial virus (RSV) subtypes, A and B, co-circulate in annual epidemics and alternate in dominance. We have shown that a subtype A RSV fusion (F) glycoprotein, stabilized in its prefusion conformation by DS-Cav1 mutations, is a promising RSV-vaccine immunogen, capable of boosting RSV-neutralizing titers in healthy adults. In both humans and vaccine-tested animals, neutralizing titers elicited by this subtype A DS-Cav1 immunogen were ~ 2- to 3-fold higher against the homologous subtype A virus than against the heterologous subtype B virus.

Methods:

To understand the molecular basis for this subtype difference, we introduced DS-Cav1 mutations into RSV strain B18537 F, determined the trimeric crystal structure, and carried out immunogenicity studies.

Results:

The B18537 DS-Cav1 F structure at 2-Å resolution afforded a precise delineation of prefusion F characteristics, including those of antigenic site Ø, a key trimer-apex site. Structural comparison with the subtype A prefusion F indicated 11% of surface residues to be different, with an alpha-carbon root-mean-square deviation (RMSD) of 1.2 Å; antigenic site Ø, however, differed in 23% of its surface residues and had an alpha-carbon RMSD of 2.2 Å. Immunization of vaccine-tested animals with DS-Cav1-stabilized B18537 F induced neutralizing responses ~100-fold higher than with postfusion B18537 F. Notably, elicited responses neutralized RSV subtypes A and B at similar levels and were directed towards both conserved equatorial and diverse apical regions.

Conclusion:

We propose that structural differences in apical and equatorial sites–coupled to differently focused immune responses–provide a molecular explanation for observed differences in elicited subtype A and B neutralizing responses.

Isolation and Structure of an Antibody that Fully Neutralizes Isolate SIVmac239 Reveals Functional Similarity of SIV and HIV Glycan Shields

HIV- and SIV-envelope (Env) trimers are both extensively glycosylated, and antibodies identified to date have been unable to fully neutralize SIV_mac239. Here, we report the isolation, structure, and glycan interactions of antibody ITS90.03, a monoclonal antibody that completely neutralized the highly neutralization-resistant isolate, SIV_mac239. The co-crystal structure of a fully glycosylated SIV_mac239-gp120 core in complex with rhesus CD4 and the antigen-binding fragment of ITS90.03 at 2.5-Å resolution revealed that ITS90 recognized an epitope comprised of 45% glycan. SIV-gp120 core, rhesus CD4, and their complex could each be aligned structurally to their human counterparts. The structure revealed that glycans masked most of the SIV Env protein surface, with ITS90 targeting a glycan hole, which is occupied in ∼83% of SIV strains by glycan N238. Overall, the SIV glycan shield appears to functionally resemble its HIV counterpart in coverage of spike, shielding from antibody, and modulation of receptor accessibility.

Ancestry Inference Using the ForenSeqTM DNA Signature Prep Kit

Objective To evaluate the effect of 56 ancestry informative single nucleotide polymorphism （aiSNP） genetic markers in the ForenSeq^TM DNA Signature Prep Kit on ancestry inference. Methods A total of 85 samples from five populations including Hebei Han population, Inner Mongolia autonomous region Mongolian population, Tibet autonomous region Tibetan population, Xinjiang Uygur autonomous region Uygur population and Nigerian population were collected. The library was constructed with the ForenSeq^TM DNA Signature Prep Kit and sequencing was performed based on the MiSeq FGx Forensic Genomics System. Using universal analysis software （UAS） of ForenSeq^TM, principal component analysis （PCA）, Structure and likelihood ratio method was used on the genotyping data of 56 aiSNP markers, respectively, and the genetic relationships between populations and inference of the origin of ancestors were analyzed. Results Among the five populations tested, the four ethnic populations in China （Hebei Han population, Inner Mongolia autonomous region Mongolian population, Tibet autonomous region Tibetan population and Xinjiang Uygur autonomous region Uygur population） could be significantly distinguished from Nigerian population. Xinjiang Uygur autonomous region Uygur individuals were shown as having mixed origins of ancestors and could be distinguished from the other three Chinese populations. However, the other three populations in China （Hebei Han population, Inner Mongolia autonomous region Mongolian population and Tibet autonomous region Tibetan population） could not be effectively distinguished by the system. Conclusion The 56 aiSNP markers in the ForenSeq^TM DNA Signature Prep Kit can make accurate ancestry inference from the intercontinental level, but it is not yet able to distinguish between Chinese subpopulations.

Prevention of Disability in the Frail Chinese Older Population

As aging is becoming a global phenomenon, the burden of population aging is increasing rapidly, and is soon expected to be the highest in low-and middle-income countries. China represents the world's largest population, and will face the largest number of older individuals, while the economy still remains developing. There is an urgent need to address the negative consequences of aging such as disability, that creates a myriad of challenges, including financial burden to the economy. In order to achieve successful aging-i.e., aging without being frail or disabled, the traditional healthcare model based on a disease-centered approach is not enough, but require a more holistic course. Here, we briefly outline the current scenario of aging and disability in the Chinese older population, its impact and challenges. We strongly believe that public health initiatives centered on frailty, a clinically distinguishable state of extreme vulnerability in older adults, could be the most relevant approach to meet the current needs of the aging population. Such initiatives are immediately needed to reshape the existing model of geriatric healthcare, to promote healthy aging and to reduce the burden of disability in the Chinese population.

An effective experimental method and apparatus for unsteady water vapor condensation investigation in high speed expansion flow

This paper presents an effective experimental method and system for mechanism study of unsteady water vapor condensation encountered in high speed expansion flow. We proposed an experimental method and designed a simplified expansion system to fulfill the study. Tunable diode laser absorption spectroscopy (TDLAS) and light sheet technique are integrated in the system to monitor the unsteady condensation process in a high speed expansion flow generated by the expansion system. Two near infrared water vapor absorption transitions (1395.0 nm and 1409.27 nm) and one near infrared methane absorption transition (1653.73 nm) are applied in the TDLAS measurement to measure the transient flow parameters during the condensation process. Using the experimental method, time dependent condensation processes are monitored with different expansion time scales. The light sheet results visually reveal the condensation phenomena during the expansion process, while TDLAS results quantitatively follow the condensation process. The experimental results are compared with computational fluid dynamics simulations and a good agreement between them is observed, which indicates that the presented experimental method and system is effective in investigating unsteady water vapor condensation in high speed expansion flow.

HLA-A*02:01:01:28, a novel HLA allele identified by next-generation sequencing in a Chinese family

HLA-A*02:01:01:28 differs from A*02:01:01:01 by one nucleotide transition, T>A 2952 in intron 6.

Next-generation sequencing-based typing of a new allele HLA-DQB1*03:01:01:20 in a Chinese family

DQB1*03:01:01:20 showed one nucleotide difference when compared to DQB1*03:01:01:01 at 224 (C>T).

Associating HIV-1 envelope glycoprotein structures with states on the virus observed by smFRET

The HIV-1 envelope glycoprotein (Env) trimer mediates cell entry and is conformationally dynamic^1–8. Imaging by single-molecule fluorescence resonance energy transfer (smFRET) has revealed that, on the surface of intact virions, mature pre-fusion Env transitions from a pre-triggered conformation (state 1) through a default intermediate conformation (state 2) to a conformation in which it is bound to three CD4 receptor molecules (state 3)^8–10. It is currently unclear how these states relate to known structures. Breakthroughs in the structural characterization of the HIV-1 Env trimer have previously been achieved by generating soluble and proteolytically cleaved trimers of gp140 Env that are stabilized by a disulfide bond, an isoleucine-to-proline substitution at residue 559 and a truncation at residue 664 (SOSIP.664 trimers)^5,11–18. Cryo-electron microscopy studies have been performed with C-terminally truncated Env of the HIV-1_JR-FL strain in complex with the antibody PGT15119. Both approaches have revealed similar structures for Env. Although these structures have been presumed to represent the pre-triggered state 1 of HIV-1 Env, this hypothesis has never directly been tested. Here we use smFRET to compare the conformational states of Env trimers used for structural studies with native Env on intact virus. We find that the constructs upon which extant high-resolution structures are based predominantly occupy downstream conformations that represent states 2 and 3. Therefore, the structure of the pretriggered state-1 conformation of viral Env that has been identified by smFRET and that is preferentially stabilized by many broadly neutralizing antibodies—and thus of interest for the design of immunogens—remains unknown.

Infrared thermography measured body surface temperature and its relationship with rectal temperature in dairy cows under different temperature-humidity indexes

The aim of this study was to better understand the inflection point of RT and BSTs and measure different body surface temperatures (BSTs) under different temperature-humidity index (THI) conditions. A total of 488 Holstein dairy cows were chosen to manually measure rectal temperature (RT) and BSTs including left side of eye, ear, cheek, forehead, flank, rump, fore udder, and rear udder by infrared thermography for 14 times. Those measurements included six times under high THI (THI > 78), three times under moderate THI (72 ≤ THI ≤ 78), and five times under low THI (THI < 72). Results showed that BSTs were affected by THI conditions (P < 0.01). The THI conditions where mean and maximum forehead temperatures started to increase rapidly (71.4 and 66.8) were lower than that where RT started to increase rapidly (74.1). The correlation coefficients of mean and maximum forehead temperatures to THI were 0.808 and 0.740, and were 0.557 and 0.504 to RT, all showing the highest as compared to other region temperatures with THI and RT, respectively. Thus, we conclude that BSTs are more sensitive to thermal environment than RT, suggesting the variability of BST to reflect body core temperature. In addition, the forehead is a relatively reliable region to assess the heat stress reflecting RT compared to the eye, ear, cheek, flank, rump, fore udder, and rear udder regions.

White matter integrity disruption in the pre-dementia stages of Alzheimer's disease: from subjective memory impairment to amnestic mild cognitive impairment

BACKGROUND AND PURPOSE

Subjective memory impairment (SMI) and amnestic mild cognitive impairment (aMCI) are thought to represent the pre-dementia stages of Alzheimer's disease (AD). SMI is considered a more advanced pre-clinical status prior to aMCI. Understanding the neuromechanism of SMI will have great benefits for monitoring the disease progression of AD. The study aims to explore whether SMI shows alterations of white matter (WM) integrity similar to the patterns of aMCI.

METHODS

The atlas-based analyses were performed to investigate the diffusion changes in the major WM tracts amongst 22 individuals with normal cognition (NC), 22 SMI patients and 25 aMCI patients. The correlations between the altered diffusion metrics and cognitive performance in the SMI and aMCI groups were assessed.

RESULTS

The diffusion tensor metrics of SMI were intermediate between the NC and aMCI groups. The aMCI group presented disrupted integrity in multiple WM tracts, including the left anterior thalamic radiation, right corticospinal tract and left cingulum of the hippocampus (CgH), compared to the NC group. The left CgH showed diffusion alterations in the SMI group. In the aMCI group, the mean diffusivity of the left CgH was negatively correlated with episodic memory, whilst the radial diffusivity of the right corticospinal tract was negatively correlated with executive function. No significant relationship was found in the SMI group.

CONCLUSION

The study suggested that SMI patients might present detectable WM integrity changes in the left CgH before exhibiting objective cognitive dysfunction, which may provide novel insights into the pathological mechanisms of AD.

Epitope-based vaccine design yields fusion peptide-directed antibodies that neutralize diverse strains of HIV-1

A central goal of HIV-1 vaccine research is the elicitation of antibodies capable of neutralizing diverse primary isolates of HIV-1. Here we show that focusing the immune response to exposed N-terminal residues of the fusion peptide, a critical component of the viral entry machinery and the epitope of antibodies elicited by HIV-1 infection, through immunization with fusion peptide-coupled carriers and prefusion stabilized envelope trimers, induces cross-clade neutralizing responses. In mice, these immunogens elicited monoclonal antibodies capable of neutralizing up to 31% of a cross-clade panel of 208 HIV-1 strains. Crystal and cryoelectron microscopy structures of these antibodies revealed fusion peptide conformational diversity as a molecular explanation for the cross-clade neutralization. Immunization of guinea pigs and rhesus macaques induced similarly broad fusion peptide-directed neutralizing responses, suggesting translatability. The N terminus of the HIV-1 fusion peptide is thus a promising target of vaccine efforts aimed at eliciting broadly neutralizing antibodies.

[Relationship between hyperuricemia and prognosis in patients with heart failure of coronary heart disease after revascularization]

Objective: To explore the effect of hyperuricemia on prognosis in patients with heart failure of coronary heart disease (CHD) after revascularization. Methods: A single-center retrospective study of all subjects who underwent percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) as revascularization for CHD at Beijing Anzhen Hospital, Capital Medical University, between January 2005 and December 2014 was performed.Patients were divided into two groups by with or without hyperuricemia.The average follow-up was 1 818 d. Results: The Logistic regression analysis revealed that hyperuricemia was independent risk factors of readmission of heart failure(P=0.018, OR=1.499, 95%CI 1.071-2.098). The Cox regression analysis revealed that hyperuricemia was independent risk factor of all-cause mortality(P=0.002, RR=1.520, 95%CI 1.166-1.982), cardiovascular (CV) mortality(P=0.001, RR=1.811, 95%CI 1.279-2.566), heart failure mortality(P=0.006, RR=2.151, 95%CI 1.247-3.711). Conclusions: There is negative correlation between level of uric acid and left ventricular ejection fraction (LVEF). The patients with heart failure of coronary heart disease complicated with hyperuricemia have high risk of readmission of heart failure, all-cause mortality, CV mortality andheart failure mortality than patients with normal uric acid level. Hyperuricemia is an independent risk factor for patients with heart failure of coronary heart disease after revascularization.

[Clinical features analysis of metanephric adenoma: a series of 16 cases]

Objective: To study the clinical characteristics, image findings, therapeutic method and prognosis of metanephric adenoma. Method: The clinical characteristic, image findings, operation methods and prognosis of 16 metanephric adenoma patients treated at Department of Urology, Peking University First Hospital from January 2004 to March 2016 were analyzed retrospectively. Results: There were 6 male and 10 female patients in the study. The mean age of patients was 33.7 years (ranging from 14 to 83 years). Two patients came to the hospital because of fever, while other 14 patients had no symptoms and found renal tumor by medical examination. One case was found polythemia vera and another 1 case showed mild anemia. Serum creatine of all the cases were in normal range. The tumor of 11 cases were at left side and 5 cases were at right. All patients took urinary tract ultrasound. Fifteen patients took CT examination. Among them, 14 cases were solid mass and 1 case was cystosolid.CT value was (41±4) HU. CT scan showed that the tumor was slight enhanced and CT value increased to (77±9) HU. Six patients took MRI examination. The MRI showed high or low signal of T1WI or T2WI scans.Tumor size was (4.7±3.9)cm (ranging from 1.7 to 17.5 cm). All 16 patients took operation and 11 of them took laparoscopic surgery while the other 5 cases took open surgery. Eleven cases took partial nephrectomy, 4 cases took nephrectomy and 1 case took nephroureterectomy. The surgical procedures were all successful and no complications occured during perioperative period. All cases were all confirmed metanephric adenoma by postoperative pathology and surgery cut edge were all negative. Immunohistochemical study showed that the positive rate of Vimentin, CD57, AE1/AE3, WT1, CK7 and AMACR respectively were 16/16, 15/16, 12/16, 10/16, 3/16 and 2/16. The median follow-up time of 16 cases was 44 months (ranging from 8 to 125 months) and none had recurrence or metastasis.One case died 125 months after surgery because of advanced age(83 years old). Conclusions: Metanephric adenoma is difficult to be diagnosed relying on clinical characteristics and image features. Pathology can help confirm the diagnosis. Partial nephrectomy is the first choice for operation and can achieve good prognosis. But it still needs a regular follow-up.

[The impact to operation safety of preoperative renal artery embolization for management of diameter≥10 cm renal cell carcinoma]

Objective: To study the impact to operation safety of preoperative renal artery embolization for management of ≥10 cm renal cell carcinoma. Methods: The clinical data of 239 cases with ≥10 cm renal cell carcinoma which all had underwent operation in Department of Urology, Peking University First Hospital from January 2002 to December 2014 were retrospectively analyzed. Fifty-three patients underwent preoperative renal artery embolization (therapeutic group) and 186 patients did not (control group). The effect of embolization on operative time, transfusion requirements, hospitalization, ICU stay and perioperative complications were analyzed by comparing the two groups using rank sum test and χ(2) test or Fisher exact test. Results: Comparing the therapeutic group and control group, there was significant difference in tumor location (on the left or right). The mean age, sex, mean primary tumor size, and TNM stage were similar in both groups. Comparing the therapeutic group and control group, there were more open surgeries in therapeutic group (96.2% vs. 82.3%, χ(2)=6.438, P=0.013). There were no significant differences in mean operative time (238 (525) minutes vs. 208 (583) minutes, Z=-2.182, P=0.062). The mean blood transfusion (700 (1 900) ml vs. 925 (8 800) ml, Z=-1.064, P=0.006) had significant difference. The therapeutic group had a longer mean hospitalization (21 (50) days vs. 15 (79) days, Z=-4.322, P=0.000) and higher rate of intensive care unit stay (54.7% vs. 34.4%, χ(2)=6.103, P=0.027). There was no significant difference in perioperative complications between two groups (0 vs.3.2%, P=0.408). Conclusion: Preoperative renal artery embolization in ≥10 cm renal cell carcinoma patients undergoing operation provides benefit in increasing operation safety and reducing perioperative death.

[Prognostic factors of patients with T2N0M0 upper tract urothelial carcinoma: a single-center retrospective study of 235 patients]

OBJECTIVE

To evaluate the impacts of the prognostic factors of T2N0M0 upper tract urothelial carcinoma (UTUC) for Chinese patients.

METHODS

A retrospective study was conducted including 235 patients who were diagnosed with T2N0M0 UTUC in our hospital and received radical nephroureterectomy (RNU) or partial ureterectomy during January 2000 and December 2013. The 3 and 5-year cancer-specific survival rates and bladder recurrence-free survival rates of all the patients were valued using Kaplan-Meier method, and the survival curves with statistical significance between the two were compared using the Log-rank test. Variables with significant differences in the univariate analysis were subjected to the multivariate analysis by Cox regression model.

RESULTS

A total of 235 patients were included in this study, including 95 (40.4%) male patients and 140 (59.6%) female patients. The mean age was 66.73±10.49 years.The median follow-up time was 53 (rang: 3-142) months, and during the follow-up, 74 (31.5%) patients died of UTUC after a median of 35 months,and 96 (40.9%) patients developed intravesical recurrence after a median of 19.5 months. The 3 and 5-year cancer-specific survival rates of all the patients were 89.1% and 85.9%, respectively; the bladder recurrence-free survival rates were 85.5% and 80.2%, respectively. The independent prognostic factors of cancer-specific mortality were tumor age elder than 55 years (HR=3.138, 95%CI: 1.348-7.306, P=0.008) and diameter larger than 5 cm (HR=3.320, 95%CI: 1.882-5.857, P<0.001). The independent prognostic factors of bladder recurrence-free survival were ureter tumor (HR=1.757, 95%CI: 1.159-2.664, P=0.008) and lower tumor grade (HR=1.760, 95% CI: 1.151-2.692, P=0.009).

CONCLUSION

T2N0M0 UTUC has a better cancer-specific survival. The intravesical recurrence was equivalent to non-muscle invasive UTUC but earlier. The tumor diameter larger than 5 cm and the patient age elder than 55 years were independently associated with cancer-specific mortality; the primary tumor located in ureter and lower tumor grade were more likely to develop intravesical recurrence.

[The loss of interproximal contact between posterior fixed implant prostheses and adjacent teeth: a retrospective study]

OBJECTIVE

To investigate the interproximal contact(IC) loss rate and the associated risk factors of IC loss between posterior fixed implant prostheses and the adjacent teeth.

METHODS

Ninety-seven posterior fixed implant prostheses including 165 IC in 78 patients(34 men, 44 women) between 23 and 76 years of age were investigated. The period after restoration ranged from 1 to 44 months. The IC between implant prostheses and adjacent teeth was evaluated using a 30-μm-thick contact gauge and dental floss, and the IC was regarded as lost when the gauge or dental floss was inserted into an IC without any resistance at follow-up visits. The state of IC, region of implant prostheses, the condition of opposing dentition, the vitality of the adjacent teeth and the time interval of tooth loss were also confirmed for correlation analysis.

RESULTS

All 78 patients finished follow-up examination. Forty-eight of 165 IC(29%) were regarded as lost. The IC loss rate at the mesial aspect[75%(36/48)] was significantly greater than that at the distal aspect[25%(12/48)](χ(2)=7.344,P=0.007). The difference between IC loss rate in the maxilla[46% (22/48)] and that in the mandible[54%(26/48)] was not significant(χ(2)=2.992,P=0.084). Free-end[hazard ratio (HR)=2.870], and the time interval of tooth loss(HR=0.919) affected the loss of IC significantly(P<0.05, Cox regression analysis).

CONCLUSIONS

Loss of IC between posterior fixed implant prostheses and adjacent teeth was one of biological complications, which was observed frequently at follow-up visits. Patients who have the free-end fixed implant prostheses, or undergo short time interval of tooth loss before restoration may have high risk of the IC loss.