Identification of a tsRNA Contributor to Impaired Diabetic Wound Healing via High Glucose-Induced Endothelial Dysfunction

PURPOSE

Delayed skin healing in diabetic wounds is a major clinical problem. The tRNA-derived small RNAs (tsRNAs) were reported to be associated with diabetes. However, the role of tsRNAs in diabetic wound healing is unclear. Our study was designed to explore the tsRNA expression profile and mine key potential tsRNAs and their mechanism in diabetic wounds.

METHODS

Skin tissues of patients with diabetic foot ulcers and healthy controls were subjected to small RNA sequencing. The role of candidate tsRNA was explored by loss- and gain-of-function experiments in HUVECs.

RESULTS

A total of 55 differentially expressed tsRNAs were identified, including 12 upregulated and 43 downregulated in the diabetes group compared with the control group. These tsRNAs were mainly concentrated in intercellular interactions and neural function regulation in GO terms and enriched in MAPK, insulin, FoxO, calcium, Ras, ErbB, Wnt, T cell receptor, and cGMP-PKG signaling pathways. tRF-Gly-CCC-039 expression was upregulated in vivo and in vitro in the diabetic model. High glucose disturbed endothelial function in HUVECs, and tRF-Gly-CCC-039 mimics further harmed HUVECs function, characterized by the suppression of proliferation, migration, tube formation, and the expression of Coll1a1, Coll4a2, and MMP9. Conversely, the tRF-Gly-CCC-039 inhibitor could attenuate high-glucose-induced endothelial injury to HUVECs.

CONCLUSION

We investigated the tsRNAs expression profile in diabetic foot ulcers and defined the impairment role of tRF-Gly-CCC-039 in endothelial function in HUVECs. This study may provide novel insights into accelerating diabetic skin wound healing.

Fracture of the lateral process of the talus with associated deltoid ligament injury: a report of 2 cases

Background

Fractures of the lateral process of the talus (LTPF) are rare and only rarely are associated ligamentous injuries. The injury mechanism is commonly considered to be similar with ankle sprains, where excessive varus of the hindfoot leads to avulsion fractures of the lateral process of the talus. However, previous cadaveric studies have suggested that LTPF was more likely to be caused by eversion or external rotation force with dorsiflexion of the ankle. But no clinical evidence has been provided.

Case presentation

Two patients presented to the emergency department with ankle pain after ankle eversion or external rotation. Physical examination revealed tenderness and swelling on both medial and lateral sides of the ankles. Plain radiographs and computed tomography revealed LTPF and medial soft tissue swelling, and magnetic resonance imaging confirmed a discontinuity of the deltoid ligament in Case 1. Surgical exploration revealed rupture of the superficial layer of the deltoid ligaments with intact deep layer in both patients. Treatment included fixation of the lateral process of the talus with headless compression screws and repair of deltoid ligaments. Both patients achieved excellent clinical outcomes 1 year post injury.

Conclusion

There are many possibilities of the injury mechanism of LTPF. These two cases provided clinical evidence that eversion or external rotation force, in addition to inversion, was also an important mechanism of LTPF.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12893-022-01781-y.

Exaggerated elastin turnover in childhood and adolescence in Marfan syndrome – correlation with age – new insights from the AIMS trial

Background

Marfan syndrome (MFS) is an autosomal dominant connective tissue disorder caused by mutations in the Fibrillin1 gene (FBN1) that leads to impaired elastin formation and extra-cellular matrix homeostasis. Elastin synthesis and related lamellae formation in the aorta is completed in the newborn. Thereafter further elastin turnover is thought to be minimal during life. Elastin homeostasis is little studied in patients with MFS who have been reported to have reduced elastin in their aorta and are at risk of aortic dilatation and consequent life-threatening dissection. It is not clear if elastin loss is due to reduced elastin formation in utero or accelerated degradation during life. However, aortopathy develops early in MFS with 70% of patients developing aortic dilatation by the age of 20 years. Therefore, the longitudinal and circumferential aortic growth that occurs in childhood may involve elastic lamellae remodelling that is impaired in MFS. Desmosine is the cross-link component in the elastin molecule and is exclusively released from mature elastin breakdown, thus is a physiologically relevant biomarker of elastin turnover. We hypothesise that physiologic aortic growth is associated with elastic lamellae remodelling and increased elastin turnover, detected by elevated plasma desmosine (pDES), and that elastin turnover is exaggerated during the fast-growing period in MFS.

Purpose

The aims of this study were 1. To investigate the relationship between elastin turnover and age in the control subjects, and 2. To compare the elastin turnover in MFS with control subjects.

Methods

pDES was measured by stable isotope dilution LC-MS/MS in 113 MFS subjects (48% male, mean age 18.2±9.4 (SD) years), mean aortic root 33.8±2.1mm and Z-score 3.4±2.1 in the AIMS trial at baseline before intervention, and in 109 healthy controls (46% male, mean age 26.1±9.5 years).

Results

pDES levels were associated positively with age, body surface area and negatively with diastolic BP in the control group (p=0.05 and 0.21 respectively after correcting for age). In MFS subjects pDES also positively correlated with age and male sex (p<0.05). Interestingly, the age-dependent association with pDES showed a peak distribution in both control and MFS groups (Figure 1) where teenage children expressed the highest pDES levels. MFS subjects had significantly higher pDES compared to controls before the age of 20 (p=0.01) but in adulthood, there was no difference (Figure 2).

Conclusion

Elastin turnover is highly dynamic before early adulthood, and peaks in adolescence and is exaggerated in MFS, suggesting that this period of growth is critical in developing aortopathy.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): British Heart FoundationTENOVUS Scotland Figure 1Figure 2

Injectable stress relaxation gelatin-based hydrogels with positive surface charge for adsorption of aggrecan and facile cartilage tissue regeneration

Background

Cartilage injury and pathological degeneration are reported in millions of patients globally. Cartilages such as articular hyaline cartilage are characterized by poor self-regeneration ability due to lack of vascular tissue. Current treatment methods adopt foreign cartilage analogue implants or microfracture surgery to accelerate tissue repair and regeneration. These methods are invasive and are associated with the formation of fibrocartilage, which warrants further exploration of new cartilage repair materials. The present study aims to develop an injectable modified gelatin hydrogel.

Method

The hydrogel effectively adsorbed proteoglycans secreted by chondrocytes adjacent to the cartilage tissue in situ, and rapidly formed suitable chondrocyte survival microenvironment modified by ε-poly-L-lysine (EPL). Besides, dynamic covalent bonds were introduced between glucose and phenylboronic acids (PBA). These bonds formed reversible covalent interactions between the cis−diol groups on polyols and the ionic boronate state of PBA. PBA-modified hydrogel induced significant stress relaxation, which improved chondrocyte viability and cartilage differentiation of stem cells. Further, we explored the ability of these hydrogels to promote chondrocyte viability and cartilage differentiation of stem cells through chemical and mechanical modifications.

Results

In vivo and in vitro results demonstrated that the hydrogels exhibited efficient biocompatibility. EPL and PBA modified GelMA hydrogel (Gel-EPL/B) showed stronger activity on chondrocytes compared to the GelMA control group. The Gel-EPL/B group induced the secretion of more extracellular matrix and improved the chondrogenic differentiation potential of stem cells. Finally, thus hydrogel promoted the tissue repair of cartilage defects.

Conclusion

Modified hydrogel is effective in cartilage tissue repair.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-021-00950-0.

Efficient Qubit Measurement with a Nonreciprocal Microwave Amplifier

The act of observing a quantum object fundamentally perturbs its state, resulting in a random walk toward an eigenstate of the measurement operator. Ideally, the measurement is responsible for all dephasing of the quantum state. In practice, imperfections in the measurement apparatus limit or corrupt the flow of information required for quantum feedback protocols, an effect quantified by the measurement efficiency. Here, we demonstrate the efficient measurement of a superconducting qubit using a nonreciprocal parametric amplifier to directly monitor the microwave field of a readout cavity. By mitigating the losses between the cavity and the amplifier, we achieve a measurement efficiency of (72±4)%. The directionality of the amplifier protects the readout cavity and qubit from excess backaction caused by amplified vacuum fluctuations. In addition to providing tools for further improving the fidelity of strong projective measurement, this work creates a test bed for the experimental study of ideal weak measurements, and it opens the way toward quantum feedback protocols based on weak measurement such as state stabilization or error correction.

Deep small RNA-Seq reveals microRNAs expression profiles in lactating mammary gland of 2 sheep breeds with different milk performance

Micro ribonucleic acid (miRNA) is a type of noncoding RNA, and it has been revealed to play important roles in the activity of the mammary gland (MG) in some species. However, the function of miRNAs in MG of sheep is poorly understood. In the study, Gansu Alpine Merino (GAM; n = 9) and Small-tailed Han sheep (STH; n = 9) with different milk production traits were investigated. Microstructures and the expression profile of miRNAs of MG tissues at peak lactation were studied. Mature alveolar lumens of MG in appearance were larger in STH than GAM. The expression levels of CSN2 and the content of rough endoplasmic reticulum were also higher in STH ewes than GAM ewes. A total of 124 mature miRNAs were expressed, and 18 of these were differentially expressed between the 2 breeds. The KEGG analysis results showed that the targeted genes of differentially expressed miRNAs were mainly involved in some metabolic pathways and signaling pathways related to MG development, milk protein, and fat synthesis. The findings in the study can improve our understanding of the roles of miRNAs in the development and lactation of MG in sheep.

Simultaneous dislocation of the radial head and distal radio-ulnar joint without fracture in an adult patient: a case report and review of literature

Background

Simultaneous dislocation of the radial head and distal radio-ulnar joint without fracture (Criss-Cross Injury) in an adult patient is rarely reported in previous studies. The pathological changes and injury patterns have not been clearly demonstrated.

Case presentation

A 26-year-old woman presented with acute pain of the right wrist and elbow after a fall from cycling. Physical examination revealed an unstable elbow and wrist joint. Plain radiographs showed volar dislocation of the radial head and dorsal dislocation of the distal radius without associated fracture, forming a criss-cross appearance of the ulna and radius on the lateral radiograph. MRI images confirmed partial rupture of the proximal interosseous membrane from its dorsal attachment on the radius, as well as partial rupture of the medial collateral ligament. Conservative treatment failed because the radiocapitellar joint and distal radio-ulnar joint could not be simultaneously reduced. Surgical exploration revealed a highly unstable radial head, but the annular ligament was found to be intact. Manual force was applied to reduce the radial head and a percutaneous K-wire was used to stabilize the proximal radioulnar joint with the forearm in full supination. After surgery, the elbow was immobilized in 90° flexion by a long arm cast for 4 weeks. The K-wire was removed at 6 weeks postoperatively. At 18 months postoperatively, the patient had regained a full range of flexion and extension, with normal supination and a slight limitation in pronation.

Conclusions

The proximal IOM, especially the dorsal band, was injured in Criss-Cross injuries, while the central part of the IOM remained intact. This injury pattern distinguished itself from Essex-Lopresti injury, which mainly involves rupture of the central band of the IOM.

[The clinical efficacy of laparoscopic cornuotomy on interstitial tubal pregnancy which diameter was shorter than 3 cm]

Objective: To investigate the clinical efficacy of Laparoscopic cornuotomy on Interstitial Tubal Pregnancy (IP) which diameter was shorter than 3 cm. Methods: The women who had IP under 3 cm diameter were selected from January, 2016 to December, 2018 at the Department of Gynecology, JiaXing Maternity and Child Health care Hospital. A total of 32 IP patients were divided into two groups. They were all treated with laparoscopic surgery. 17 patients were in study group, conducted by a cornuotomy and suturing the cornual.15 patients were in control group, conducted by a cornual resection and suturing the cornual. Patients' genenral conditions were not significantly different(all P values>0.05). The peri-surgical data and the related clinical data were compared in the two groups. Results: All the 32 patients were successfully treated by laparoscopic surgery. The mean operating time was significantly shorter for cornuotomy than for cornual resection[ (33±6) min vs (53±9) min, P<0.05].Changes in blood loss[(45±5) ml vs (50±7) ml]、the total hospital stays[ (4.4±1.4) d vs (4.6±1.4) d] and the recovery time of HCG[(16±5) d vs (15±5) d] were not significantly different between the two groups (all P values>0.05) . There were no persistent ectopic pregnancy and uterine rupture happened in two groups. Compared with the control group,the interval time to pregnancy was shorter[ (8±3) m vs (16±4) m, P<0.05] and the number of full-term pregnancy cases were more (9 vs 3, P<0.05). Conclusion: The Laparoscopic cornuotomy was feasible and safe on interstitial tubal pregnancy which diameter was shorter than 3cm. It deserved popularization in the clinical work and regarded as one of selection operative treatment on interstitial heterotopic pregnancy.

[Analysis of the occurrence of interstitial pregnancy during the re-pregnancy after modified tubal resection or ligation]

Objective: To investigate the effect of modified tubal resection or ligation on the incidence of interstitial pregnancy during the re-pregnancy. Methods: Patients who underwent tubal resection or ligation in our hospital from June 2017 to June 2019 were selected as research subjects and randomly divided into observation group and control group, with 43 cases in each group.The observation group received modified tubal resection or ligation, while the control group received traditional tubal resection or ligation, and the occurrence of re-gestation interstitial pregnancy was followed up. Results: A total of 86 subjects were included, with an average age of (32.3±2.6) years old, 2-5 pregnancies, and 2-4 births. There was no statistical difference in general data between the two groups.The success rate of operation in both groups was more than 95%, with 6.98% (3/43) patients in the observation group having temporary fever and other discomforts after operation, and 9.30%(4/43) patients in the control group having good outcomes.In the observation group and the control group, 36 and 34 patients underwent in vitro fertilization and embryo transfer three months after the operation, respectively, and 23 pregnancies were successful in each group. All pregnancies in the observation group were intrauterine, and no ipsilateral tubal interstitial pregnancy occurred; in the control group, 19 were intrauterine pregnancies, and 4 cases of ipsilateral tubal interstitial pregnancy occurred.Ipsilateral tubal interstitial pregnancy after modified tubal ligation was significantly lower than that after traditional tubal resection or ligation (χ(2)=4.195, P=0.041). Conclusion: Modified tubal ligation and resection can effectively reduce the occurrence of interstitial pregnancy during the re-pregnancy.

Ultrastrong Parametric Coupling between a Superconducting Cavity and a Mechanical Resonator

We present a new optomechanical device where the motion of a micromechanical membrane couples to a microwave resonance of a three-dimensional superconducting cavity. With this architecture, we realize ultrastrong parametric coupling, where the coupling not only exceeds the dissipation in the system but also rivals the mechanical frequency itself. In this regime, the optomechanical interaction induces a frequency splitting between the hybridized normal modes that reaches 88% of the bare mechanical frequency, limited by the fundamental parametric instability. The coupling also exceeds the mechanical thermal decoherence rate, enabling new applications in ultrafast quantum state transfer and entanglement generation.

Pinopode score around the time of implantation is predictive of successful implantation following frozen embryo transfer in hormone replacement cycles

STUDY QUESTION

Is pinopode measurement of any prognostic value?

SUMMARY ANSWER

Pinopode expression was significantly associated with the occurrence of pregnancy after frozen embryo transfer.

WHAT IS KNOWN ALREADY

Pinopodes are expressed in the endometrium during the implantation period. Pinopode measurement has been proposed as a marker of endometrial receptivity.

STUDY DESIGN, SIZE, DURATION

A prospective cohort study was conducted at the Center of Reproductive Medicine, Sir Run Run Shaw Hospital, between 2014 and 2016, recruiting 172 women with infertility and undergoing frozen embryo transfer following IVF treatment. Among 172 participants, 46 women took part in the first study to quantify the daily changing pattern of pinopodes 3-7 days after the initiation of progesterone therapy in the hormone replacement cycles and the remaining 126 women with infertility participated in a study to examine the relationship between pinopode count and pregnancy outcome following frozen embryo transfer in hormone replacement cycles.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The mean age of participants was 29 years old. All participants received an artificial hormone replacement protocol capable of supporting successful implantation. Endometrial biopsies from 46 women were obtained 3, 4, 5, 6 and 7 days after the initiation of progesterone therapy (P + 3, n = 6; P + 4, n = 6; P + 5, n = 11; P + 6, n = 13; P + 7, n = 10, respectively). Another 126 endometrial biopsies were obtained precisely 6 days after the initiation of progesterone. Scanning electron microscopy was used to capture the pinopode images, followed by use of the image J program to quantify the count and subtype of the pinopodes.

MAIN RESULTS AND THE ROLE OF CHANCE

We found that at least 60 microscopic fields were necessary to achieve a reproducible result. An intra-observer variability study showed good agreement between two measurements regarding the developing pinopode (DP) subtype (r = 0.95) and the fully developed pinopode (FDP) subtype (r = 0.86) but not for the regressing (RP) pinopode subtype (r = 0.39). The proportion of DP/total pinopodes (TP) declined rapidly form day P + 4 to a minimum on day P + 6. The percentage of FDP/TP increased rapidly from day P + 4 to reach a peak on day P + 6. On the other hand, the percentage of RP/TP reached a peak on day P + 7. Participants who conceived had a significantly (P = 0.011) higher percentage of FDP/TP on day P + 6 and significantly (P = 0.005) lower percentage of DP/TP on the same day compared with participants who did not become pregnant. Using a scoring system incorporating the percentages of DP and FDP, it was found that the pregnancy rate and the embryo implantation rate of women with a high pinopode score (82.3%; 63.0%) was significantly (P = 0.001; P = 0.046) higher than that of women with a low pinopode score (53.3%; 46.7%), respectively. There remains a possibility that the observations could have arisen due to chance.

LIMITATIONS, REASONS FOR CAUTION

This study examined pinopode count and subtype in the HRT cycles, and it is uncertain whether the same observations apply to in natural cycles.

WIDER IMPLICATIONS OF THE FNDINGS

Pinopodes have been questioned as a potential marker of endometrial receptivity for many years. Our results suggested that pinopode measurement may be of value in predicting pregnancy.

STUDY FUNDING/COMPETING INTEREST(S)

The study was supported by the grants from the general project of medicine and health in Zhejiang Province of China (2015KYA142; 2018KY106), the Key Research and Development Program of Zhejiang Province (2017C03022) and the National Natural Science Foundation of China (81701514).The funders had no role in the study design, data collection and analysis, decision to publish or preparation of the manuscript. We have no competing interests to declare.

TRIAL REGISTRATION NUMBER

ISRCTN26300668.

[Genetic Polymorphisms of 30 InDel Loci in Ewenki Ethnic Group from Inner Mongolia]

OBJECTIVES

To study the genetic polymorphisms of 30 insertion/deletion （InDel） loci and evaluate their forensic application in Ewenki ethnic group from Inner Mongolia.

METHODS

Peripheral blood samples were collected from 87 unrelated healthy individuals in Ewenki ethnic group. Genomic DNA were extracted, and 30 InDel loci of the samples were multiplex amplified and genotyped. Hardy-Weinberg balance tests were preformed for all loci and genetic parameters were calculated by modified PowerStats v1.2 software. The linkage disequilibrium between loci were tested by SNPAnalyzer v2.0 software. Based on the allele frequencies of 30 InDel loci, the genetic relationships between Ewenki ethnic group and other populations were evaluated by analysis of molecular variance, principal component analysis and phylogenetic reconstruction.

RESULTS

After correction, 30 InDel loci conformed to Hardy-Weinberg equilibrium. It was found that the pairwise InDel loci were in linkage equilibrium after Bonferroni correction. The results of population genetics indicated that Ewenki ethnic group had close genetic relationships with Henan Han and Beijing Han populations; whereas it was significantly different from several populations in Europe and Mexico.

CONCLUSIONS

There are relatively high genetic polymorphisms on 30 InDel loci of Ewenki ethnic group from Inner Mongolia, which can be used as a helpful supplement application for STR detection system.

[Validation of the Chinese version of Hull airway reflux questionnaire and its application in the evaluation of chronic cough]

OBJECTIVE

To validate the effectiveness, repeatability and treatment responsiveness of the Chinese version of Hull airway reflux questionnaire (HARQ), and to determine its clinical value.

METHODS

A standard Chinese version of HARQ was developed by an established translation procedure and its repeatability was assessed in a preliminary study involving 55 untreated patients with stable chronic cough. Thereafter, a total of 132 patients with chronic cough referred to our respiratory clinic were recruited into the study between May 2014 and April 2015. After their cough was evaluated with the HARQ, cough symptom score or cough reflex sensitivity to inhaled capsaicin and the correlations among them were analyzed, and the causes of chronic cough in all the patients were presumptively determined according to an established diagnostic protocol and finally confirmed with the subsequent therapy specific to the etiologies. After two weeks of effective treatment, HARQ, cough symptom score and cough reflex sensitivity to inhaled capsaicin were measured once more, and treatment responsiveness was calculated. The score of the HARQ in 132 patients with chronic cough were compared with that in 104 healthy volunteers.

RESULTS

The repeatability of the Chinese version of the HARQ was validated at a week interval with the intraclass correlation coefficients of 0.96 (95%CI: 0.93-0.98, P=0.00) for total score (n=55). No correlation was found between the HARQ and cough symptom score, and the HARQ showed a weak negative correlation with cough threshold C2 (rIgC2=-0.23, P=0.01) but not with C5. The value of HARQ was significantly higher in patients with chronic cough than in healthy volunteers[20.00(14.00, 28.00) vs 4.00 (2.00, 6.00), Z=-12.89, P=0.00], but no difference of HARQ in gender or age existed in chronic cough. Although all the patients with various etiologies of chronic cough had an increased value of HARQ, cough due to gastroesophageal reflux showed the highest HARQ score among them[28.50 (25.00, 32.25) vs 18.50 (14.00, 26.25), Z=4.43, P=0.00]. After two weeks of effective treatment, the HARQ score decreased from 20.00 (14.00, 28.00) pre-treatment to 10.00 (4.25, 17.75) post-treatment (Z=-6.06, P=0.00), with 52.04% of score change ratio, 1.38 of effect side and 1.97 of standard response mean respectively.

CONCLUSION

HARQ is a reliable and valid tool for the management of chronic cough with good treatment responsiveness, and may be used as an easy way to predict cough due to gastroesophageal reflux.

Comparative efficacy of whole-brain radiotherapy with and without elemene liposomes in patients with multiple brain metastases from non-small-cell lung carcinoma

PURPOSE

We explored and compared the clinical effects of whole-brain radiotherapy (wbrt) with and without elemene liposomes in patients with multiple brain metastases from non-small-cell lung carcinoma (nsclc).

METHODS

We retrospectively analyzed 62 patients with multiple brain metastases from nsclc who received wbrt (30 Gy in 10 fractions) at Shengjing Hospital of China Medical University from January 2012 to May 2013. In 30 patients, elemene liposomes (400 mg) were injected intravenously via a peripherally inserted central catheter for 21 consecutive days from the first day of radiotherapy. Overall survival (os) and nervous system progression-free survival (npfs) for the two groups were compared by Kaplan-Meier analysis. Factors influencing npfs were examined by Cox regression analysis. Chi-square or Fisher exact tests were used for group comparisons.

RESULTS

The median os was 9.0 months in the wbrt plus elemene group and 7.8 months in the wbrt-alone group (p = 0.581); the equivalent median npfs durations were 5.2 months and 3.7 months (p = 0.005). Patient treatment plan was an independent factor associated with npfs (p = 0.002). Tumour response and disease-control rates in the wbrt plus elemene group were 26.67% and 76.67% respectively; they were 18.75% and 62.5% in the wbrt group (p = 0.452). Compared with the patients in the wbrt-alone group, significantly fewer patients in the wbrt plus elemene group developed headaches (p = 0.04); quality of life was also significantly higher in the wbrt plus elemene group both at 1 month and at 2 months (p = 0.021 and p = 0.001 respectively).

CONCLUSIONS

The addition of elemene liposomes to wbrt might prolong npfs in patients with multiple brain metastases from nsclc, while also reducing the incidence of headache and improving patient quality of life.

[Gene typing and antibiotic resistance of methicillin-resistant Staphylococcus aureus isolated from lower respiratory tract at two hospitals in Shanghai]

OBJECTIVE

To study the genotyping characteristics and antibiotic resistance of methicillin-resistant Staphylococcus aureus(MRSA) isolated from lower respiratory tract at 2 different level hospitals in Shanghai.

METHODS

The subjects included 155 patients at Ruijin Hospital and Tongren Hospital between January 2013 and June 2014, including 108 males and 47 females, with a mean age of 67.8±16.5. The 155 MRSA strains were isolated from lower respiratory tract specimens and multilocus sequence typing (MLST) and spa typing were analyzed by the PCR method. The antimicrobial resistance of MRSA was tested by VITEK-32. Fisher's exact test was used for statistical analysis.

RESULTS

Among the 155 strains, 28 MLST-spa molecular types were identified, of which ST764-t002(41.29%), ST239-t037(17.42%) and ST239-t030(10.32%) were the most predominant types. The MRSA strains were susceptible to linezolid, vancomycin and teicoplanin, and also had a lower resistance to trimethoprim-sulfamethoxazole and rifampin, with a susceptible rate of 83.9% and 83.2% respectively, but were highly resistant to other antibiotics. The resistance rate of ST239-t037 to trimethoprim-sulfamethoxazole was higher than that of other types, and the resistance rate of ST239-t030 to rifampin was higher than that of other types, the differences being significant(P<0.001). The mean length of hospital stay of the 155 patients was (97±84) days, and mechanical ventilation were used in 78(50.3%) patients, while 108(69.7%))patients received invasive procedures. Broad-spectrum antibiotics were used in 136 (87.1%) patients. There were differences in age, hospitalization days, smoking history, history of COPD, mechanical ventilation, and operation between the 2 hospitals(P<0.05).

CONCLUSION

Most of the MRSA strains at Ruijin Hospital and Tongren Hospital between January 2013 and June 2014 were multi-drug resistant, and the susceptibility spectrum of different genotypes was different.

CASP-9 gene functional polymorphisms and cancer risk: a large-scale association study plus meta-analysis

We investigated the association between CASP-9 polymorphisms and susceptibility to neoplasm. Fourteen studies with a total of 2733 neoplasm cases and 3352 healthy controls were included. Meta-analysis showed that the rs4645981 T allele and the rs4645981 T allele carrier were positively associated with neoplasm susceptibility [odds ratio (OR) = 1.43, 95% confidence interval (95%CI) = 1.12-1.81, P = 0.004; OR = 1.46, 95%CI = 1.10-1.93, P = 0.009, respectively]. However, the rs1052576 A allele, rs1052576 A carrier, rs2308941 T allele, and rs2308941 T carrier might decrease the risk of cancer (OR = 0.72, 95%CI = 0.58-0.89, P = 0.003; OR = 0.76, 95%CI = 0.63-0.92, P = 0.004; OR = 0.20, 95%CI = 0.09-0.45, P < 0.0001; OR = 0.21, 95%CI = 0.06-0.75, P = 0.02, respectively). There was no significant association between rs1263, rs1052571, rs2308950, rs4645978, rs4645980, rs4645982, and rs4646018 and cancer risk (all P > 0.05). In conclusion, this meta-analysis suggests that CASP-9 gene polymorphisms are involved in the pathogenesis of various cancers. The rs4645981 T allele and the rs4645981 T allele carrier might increase the risk of cancer, but the rs1052576 A allele, rs1052576 A carrier, rs2308941 T allele, and rs2308941 T carrier might be protective.

Meta-analysis demonstrates association of XRCC1 genetic polymorphism Arg399Gln with esophageal cancer risk in the Chinese population

We made a meta-analysis of the association between X-ray cross-complementing gene 1 (XRCC1) genetic polymorphism Arg399Gln and esophageal cancer (EC) risk. Statistical analysis was performed with the Review Manager version 4.2.8 software program and STATA version 11.0. We selected 16 case-control studies for this meta-analysis, including 3591 EC cases and 5752 controls. Overall, the Gln399 allele was not associated with EC risk, compared with the Arg399 allele in the populations included in the analysis. However, stratified analysis revealed that the Gln399 allele was associated with increased EC risk among the Chinese population in a recessive model [odds ratio (OR) = 1.42; 95% confidence interval (95%CI) = 1.07-1.90; P = 0.02 for heterogeneity] and by homozygote contrast (OR = 1.43; 95%CI = 1.05-1.96; P = 0.02 for heterogeneity), particularly for the tumor histology of squamous cell carcinoma (OR = 1.46; 95%CI = 1.10-1.95 for the recessive model and OR = 1.42; 95%CI = 1.03-1.95 for the homozygote contrast). We conclude that the XRCC1 Arg399Gln polymorphism has potential as a biomarker for EC susceptibility in the Chinese population, particularly for squamous cell carcinoma.

A literature-based systematic HuGE review and meta-analysis show that CASP gene family polymorphisms are associated with risk of lung cancer

The caspase (CASP) gene family is known to be involved in apoptosis, cytokine maturation, cell growth, and differentiation. A large number of single nucleotide polymorphisms (SNPs) in the CASP gene family have been increasingly recognized as important regulators in the development of lung cancer. However, this specific association is still controversial. In this Human Genome Epidemiology review and meta-analysis, we summarized the available evidence associating lung cancer with the CASP gene family. Seven studies, which included 1155 lung cancer cases and 1120 healthy controls, met the inclusion criteria and were included in our meta-analysis. In seven studies, 19 different SNPs have been studied in seven CASP genes, including CASP-1, -2, -5, -7, -8, -9, and -10. Meta-analysis results showed positive associations between heterozygote (A/G) of rs507879 in the CASP-5 gene, the T allele of rs12415607 in the CASP-7 gene, and the T allele and T carrier (C/T+T/T) of rs4645981 in the CASP-9 gene with lung cancer susceptibility [odds ratio (OR) = 1.83, 95% confidence interval (95%CI) = 1.07-3.12, P = 0.03; OR = 1.18, 95%CI = 1.02-1.37, P = 0.03; OR = 1.43, 95%CI = 1.12-1.81, P = 0.004; OR = 1.46, 95%CI = 1.10-1.93, P = 0.009; respectively]. However, we found that homozygote (G/G) of rs2227310 in the CASP-7 gene, del allele, heterozygote (ins/del), and del carrier (ins/del + del/del) of rs3834129 in CASP-8 could be protective factors for lung cancer (OR = 0.17, 95%CI = 0.14-0.21, P = 0.0003; OR = 0.83, 95%CI = 0.72-0.97, P = 0.02; OR = 0.74, 95%CI = 0.64-0.85, P < 0.0001; OR = 0.81, 95%CI = 0.71-0.93, P = 0.002; respectively). In conclusion, based on this meta-analysis, we suggest that SNPs in CASP-5, -7, -8, and -9 are associated with susceptibility to lung cancer.

Serum levels of selenium in patients with brain metastases from non-small cell lung cancer before and after radiotherapy

PURPOSE

This study was to evaluate the influence of radiotherapy on the selenium serum levels of non-small cell cancer patients with brain metastases.

PATIENTS AND METHODS

This prospective study included 95 non-small cell cancer patients with brain metastases treated by radiotherapy from December 2007 until November 2010. Plasma selenium levels were determined before and at the end of the radiotherapy. Age, body mass index (BMI), prior chemotherapy, pathological type and personal habits (smoking and alcoholism) were recorded for each patient.

RESULTS

The mean age was 63 years; the mean BMI was 27.6. Seventy-six patients (80%) were non-smokers. Sixty-two patients (65.3%) showed no drinking habits and 8 (8.4%) have no prior chemotherapy. Thirty-nine patients (41.1%) were adenocarcinoma, 51 (53.7%) were squamous cell carcinoma and five (5.3%) were large cell carcinoma. At the beginning of radiotherapy, the mean selenium level for all patients was 90.4 μg/l and after radiation this value dropped to 56.3 μg/l. Multivariate analysis showed statistically significant difference in the plasma selenium concentration before and after radiotherapy for age (P<0.001), BMI (P<0.001), smoking (P<0.001), alcoholism (P<0.001), prior chemotherapy (P<0.001) and pathological type (P<0.001).

CONCLUSION

Significant reduction in plasma levels of selenium was recorded in patients undergoing radiotherapy, suggesting attention to the nutritional status of this micronutrient and other antioxidant agents.

Safety and radiation-enhancing effect of sodium glycididazole in locoregionally advanced laryngeal cancers previously treated with platinum-containing chemotherapy regimens: A preliminary report

PURPOSE

To determine the safety and radiation-enhancing effect of sodium glycididazole in laryngeal squamous cell carcinoma (stage T3-4,N0-3,M0) with conventional radiotherapy.

PATIENTS AND METHODS

Patients with locoregional advanced laryngeal cancer (stage T3-4,N0-3,M0) were included: group 1(control, n=30)were not administered of sodium glycididazole; group 2 (test, n=30) received sodium glycididazole at a dose of 700 mg/m(2) intravenous infusion 30 minutes before radiotherapy three times a week. Surrogate end-points of efficacy were tumor and nodal size. Safety parameters were vomiting, nausea, mucositis, laryngeal edema, esophagus and skin reaction, dysphagia, dyspnea, neurological deficit. Patients were evaluated weekly during treatment for 7 weeks and thereafter monthly for 3 months.

RESULTS

In the test, the overall response rate was 88.89% (95%CI, 71.00-97.00%) at 7 weeks and 92.59% (95%CI, 76.00 to 99.00%) at 1 month of follow-up. In the control, the overall response rate was 62.5% (95%CI, 41.00 to 81.00%) at 7 weeks and 58.33% (95%CI, 37.00 to 78.00%) at 1 month of follow-up. The short-term locoregional response rate was better in the test group at 7 weeks (p=0.027) and at 1 month (p=0.005) of follow-up. The test group had significantly more nausea and vomiting in weeks 1 (p=0.047), 2 (p=0.007), and 3 (p=0.01) of treatment.

CONCLUSIONS

The study indicates sodium glycididazole is an effective radiation-enhancing agent that improves short-term locoregional control and is well tolerated in patients with locoregionally advanced laryngeal cancer.

Enhanced macroscopic quantum tunneling in Bi2Sr2CaCu2O8 + delta intrinsic Josephson-junction stacks

We have investigated macroscopic quantum tunneling in Bi(2)Sr(2)CaCu(2)O(8 + delta) intrinsic Josephson junctions at millikelvin temperatures using microwave irradiation. Measurements show that the escape rate for uniformly switching stacks of Nu junctions is about Nu(2) times higher than that of a single junction having the same plasma frequency. We argue that this gigantic enhancement of the macroscopic quantum tunneling rate in stacks is boosted by current fluctuations which occur in the series array of junctions loaded by the impedance of the environment.

Aortic root remodeling in atheromatous aneurysms: the role of selected sinus repair

OBJECTIVE

Atheromatous ascending aortic aneurysms (AAA) frequently present with aortic regurgitation (AR) from dilatation of the sino-tubular junction (STJ) and extension of the pathological process into the root. Experience suggests that root dilatation begins in the non-coronary, then right coronary sinus. Rather than employ aortic root replacement or the David procedure, we have elected to replace the ascending aorta and remodel the STJ and involved sinuses. We studied the outcome after selective sinus replacement in 29 consecutive AAA patients between 1995 and 2001.

METHODS

There were nine male and 20 females. Age ranged from 47 to 79 years (mean 67.5). Seven had arch aneurysms and four coronary artery disease. Nineteen were NYHA III or IV. Grade of AR was IV in 20, III in five and II in four. The STJ was dilated >50% of annulus diameter in each case (5.3-10.0 cm, mean 6.4 cm). All valves had three cusps. All patients underwent ascending aortic replacement. Seven had arch replacement and four coronary artery bypass. Seven had replacement of both right and non-coronary sinuses with re-implantation of the right coronary ostium. Twelve had replacement of the non-coronary sinus alone whilst nine had right coronary sinus replacement. One with dextrocardia had left coronary sinus replacement with ostial re-implantation. The graft size was within 2 mm of annulus size except for two patients (24 mm 12, 26 mm 11, and 28 mm six). Post operative echocardiographic studies were performed. None of the patients received anticoagulation.

RESULTS

There were no hospital or late deaths and no thromboembolic or infective complications. Two patients had mild to moderate aortic regurgitation. These had a size 28 graft, which in retrospect was too large. Others had no significant regurgitation.

CONCLUSIONS

The native aortic valve can be preserved in the majority of patients with AAA. Remodelling of the STJ and selective sinus replacement restores valve competence. Anticoagulation and prosthesis related complications are thereby avoided.

Pericardial stentless aortic valves: effects of sizing on hemodynamics and root geometry

The objective of this study was to determine the effects of sizing policy for pericardial stentless valves on hemodynamic performance and aortic root geometry. Discharge echocardiography was performed on 103 patients out of 110 consecutive implants (54 men and 49 women, mean age 75 +/- 9 years, and 36% with Co-CABG). Valve prosthesis size was based on largest annulus size plus 1 to 2 mm in the first 50 implants (group A, n = 48). Following continuous echo assessment, sizing policy was changed to annulus size plus 3 to 4 mm in the next 60 implants (group B, n = 55). Sinotubular (ST) junction was kept within 115% of the annulus size by surgical remodeling of aortic root. In comparison with group A, group B had a 7% larger valve size (25.2 +/- 2.1 mm v 23.6 +/- 2.3, mm, P <.01) implanted for patients of same body surface area and left ventricular cavity size. However, group B has a 38% lower mean pressure gradient (4.0 +/- 2.7 v 6.5 +/- 3.2, mm Hg, P <.01), a 32% greater effective orifice area (2.3 +/- 0.9 cm(2) v 1.7 +/- 0.7 cm(2), P <.01), better root distensibility (9.3% +/- 6.0% v 6.8% +/- 4.1%, P =.026), and a lower ratio of ST junction to valve size (0.92 +/- 0.13 v 0.99 +/- 0.14, P =.009). Group B also had lower grade of prosthesis regurgitation (0.35 +/- 0.62 v 0.89 +/- 1.1, P =.002). Sizing of pericardial stentless aortic valves by annulus diameter plus 3 to 4 mm provides better valve competence and hemodynamic efficiency by improving aortic root geometry and distensibility. Pericardial stentless valves may be of advantage in elderly patients with significant geometric root mismatch.

Performance of Edwards prima stentless aortic valve over eight years

Long-term clinical and hemodynamic performance is a key consideration in using a stentless aortic bioprosthesis. This study reports clinical and hemodynamic performance of Prima stentless aortic valve during our 8-year follow-up. In the study, 85 patients underwent aortic valve replacement (Edwards Prima or Prima plus stentless valve) and had follow-up at discharge and then annually up to 8 years. The mean age at operation was 72 +/- 5 yrs, 49 were male and 25% underwent concomitant CABG. Doppler Echo studies were performed to determine mean pressure gradient (mPG), effective orifice area (EOA) and the degree of regurgitation of stentless valves. Aortic root geometry was assessed by the ratio of sinotubular junction to valve size at peak systole. Patient survival rate was 82% +/- 5% at 5th year and 72% +/- 6% at 8th year. The freedom from valve structure failure was 97% +/- 2% at 5th and 8th year. Valve mPG and EOA at 8 years remained significantly better than those at discharge (6.8 +/- 4.4 mm Hg v 9.7 +/- 6.2 mm Hg; 1.91 +/- 0.54 cm(2) v 1.63 +/- 0.71 cm(2), both P <.01), and did not differ from those at 3-year follow-up. Mean sinotubular junction diameter remained below valve size (0.96 +/- 0.14). Mild degree of valvular regurgitation was present in 17% of patients, but this did not progress over the period of follow-up. After aortic valve replacement with the Prima stentless valves, excellent valve hemodynamics and normal root geometry were well maintained up to 8 years, but longer-term follow-up of a larger cohort remains essential.

In vivo hemodynamic characteristics of porcine stentless aortic valves

The objective of this study was to elucidate the relationship of aortic pressure gradient (mPG) and effective orifice area (EOA) with mean systolic flow rate of left ventricle in patients who received a stentless aortic valve. Two hundred thirteen patients (age: 73 +/- 6 years, 123 men and 90 women) who received a Freestyle stentless valve in subcoronary position for aortic valve diseases were studied. EOA, mPG, and systolic aortic flow rate were determined by Doppler echocardiography at 1 and 20 months after implant. With follow-up, there was a 13% increase in EOA and a 30% decrease in mPG, both P <.01. Although systolic aortic flow did not change, the intercept of EOA-flow relationship increased significantly at late follow-up (0.56 +/- 0.13 v 0.11 +/- 0.13, P <.01). Multiple regression analysis showed that systolic aortic flow accounted for 54%, and mPG for only 27%, variation of EOA. Linear relationship between EOA and systolic aortic flow provides a comprehensive approach to describe stentless valve performance, when mean valve pressure gradient appears to be flow independent. These hemodynamic features distinguish stentless valves from stented or mechanical prosthesis. Ultimately, the variations in aortic root anatomy, surgical experience and their interactions are likely to become major determinants of in vivo performance of stentless aortic valves.

Does the use of a stentless bioprosthesis increase surgical risk?

Stentless aortic bioprostheses (SBPs) convey hemodynamic and perhaps survival benefit over stented counterparts. The aim of this study was to determine whether the more taxing operation increases surgical risk. We studied contemporary multicenter (USA) data submitted to the Food and Drug Administration (FDA) for Freestyle stentless (group I, n = 583) and Mosaic stented xenograft approval (group II, n = 1260). The study compared 30-day mortality for the two groups overall, then for isolated aortic valve replacement (AVR) and for AVR and coronary bypass (CABG). Because the USA Freestyle valves were used in selected patients (pts) we included SBP data (group III) from Oxford, where Freestyle valves were used consecutively within the same time frame. We also reviewed hospital mortality in the stentless bioprosthesis literature and compared this with the Society of Thoracic Surgery Database. There were no differences in age, NYHA, or incidence of CABG between the groups. There was no significant difference in operative mortality between stented (group II) and exclusive (group III) SBP patient groups (P =.233 for AVR and P =.478 for AVR + CABG), or between selective (group I) and exclusive (P =.929 for AVR and P =.390 for AVR + CABG) groups, after adjustment for risk factors. However, there was a significantly higher mortality both for isolated AVR (P =.026) and AVR + CABG (P =.001) in the selected stentless group compared with stented. This was partly attributed to greater mortality when the Freestyle was used in elderly patients by the full root replacement method, and to the higher proportion of females, and subjects with intra-aortic balloon pump insertion in this group. A meta-analysis of published stentless valve series, showed mortality rates to be lower than those of the STS National Database average. During the learning curve selective use of SBPs increased hospital mortality for AVR +/- CABG. Consecutive use dispelled the difference and the literature now suggests that SBPs may reduce hospital mortality for high-risk patients.

Pericardial and porcine stentless aortic valves: are they hemodynamically different?

BACKGROUND

We sought to compare the early hemodynamic performance of pericardial stentless aortic valves with that of well-established porcine stentless aortic prostheses.

METHODS

A total of 169 patients (97 men and 72 women, aged 73+/-6 years) undergoing aortic valve replacement received either a pericardial (Pericarbon, Sorin Biomedica, Saluggia, Italy; n = 89) or a porcine (Freestyle, Medtronic, n = 80) stentless aortic valve. Aortic valve hemodynamics and root dynamism were assessed by Doppler echocardiography at discharge and 12 months after implantation.

RESULTS

Clinical demographic data, valve size (24.0+/-1.9 vs 24.6+/-2.3 mm), and body surface area (1.85+/-0.19 vs 1.80+/-0.19 m2) did not differ between porcine and pericardial valves (both p > 0.05). The 1-year postoperative mean valve pressure gradient (4.2+/-2.6 vs 3.7+/-2.6 mm Hg), effective orifice area (2.2+/-0.8 vs 2.2+/-0.8 cm2), and left ventricular ejection fraction (62+/-13 vs 63+/-13, %) also did not differ (all p > 0.05). However, at discharge, systolic increase in aortic sinus diameter was significantly greater in pericardial valves than in porcine ones (7.7+/-5.7 vs 4.9%+/-4.2%, p < 0.01). Furthermore, pericardial valves had a greater slope of effective orifice area-systolic aortic flow relationship (0.89+/-0.07 vs 0.70+/-0.06, cm2/100 mL/s, p < 0.01).

CONCLUSIONS

Nonprosthetic thin-walled pericardial valves appear to offer better aortic root dynamism and more efficient hemodynamics than those of porcine valves immediately after implant. At 1-year follow-up, however, both types of stentless valves provide equally excellent hemodynamics. The clinical choice between the two will depend on their long-term durability.

First permanent implant of the Jarvik 2000 Heart

BACKGROUND

Heart failure is a major public-health concern. Quality and duration of life on maximum medical therapy are poor. The availability of donor hearts is severely limited, therefore an alternative approach is necessary. We have explored the use of a new type of left-ventricular assist device intended as a long-term solution to end-stage heart failure.

METHODS

As part of a prospective clinical trial, we implanted the first permanent Jarvik 2000 Heart--an intraventricular device with an innovative power delivery system--into a 61-year-old man (New York Heart Association functional class IV) with dilated cardiomyopathy. We assessed the effect of this left-ventricular assist device on both native heart function and the symptoms and systemic characteristics of heart failure.

FINDINGS

The Jarvik 2000 Heart sustained the patient's circulation, and was practical and user-friendly. After 6 weeks, exercise tolerance, myocardial function, and end-organ function improved. Symptoms of heart failure have resolved, and continuous decreased pulse-pressure perfusion has had no adverse effects in the short term. There has been no significant haemolysis and no device-related complications. The skull-mounted pedestal is unobtrusive and has healed well.

CONCLUSIONS

The initial success of this procedure raises the possibility of a new treatment for end-stage heart failure. In the longer term, its role will be determined by mechanical reliability.

Survival advantage of stentless aortic bioprostheses

BACKGROUND

Bioprostheses (BPs) are used to avoid anticoagulation after aortic valve replacement (AVR) in patients over 65 years of age. Stentless BPs offer established hemodynamic benefits. We sought to determine whether these advantages translate into improved survival.

METHODS

Between 1993 and 1997, follow-up data (for Food and Drug Administration submission) were collected prospectively for 160 consecutive, unselected hospital survivors who received the Freestyle valve (FS). Equivalent data were collected for 247 Carpentier-Edwards (CE) porcine xenograft patients. Detailed comparative statistical analysis was used to compare events and survival between the groups. Follow-up was 100% complete for the FS (5.2 years maximum; mean 3.2+/-1.0 years) group and 98% (7.2 years maximum; mean 3.8+/-2.0 years) for CE.

RESULTS

The groups were well matched in age (FS, 73+/-6 years; CE, 74+/-6 years), gender (FS, 58% male; CE, 62% male), ventricular function, and number of patients requiring coronary grafts (FS, 41%; CE, 37%). Actuarial survival at 5 years was 84% for FS versus 69% for CE (p = 0.023 Kaplan Meier, p = 0.009 Cox). Annual mortality rates were 3.6% for FS versus 7.1% for CE (p = 0.001). Thromboembolic rate was 0.8% per year for FS and 2.4% for CE (p = 0.024) without a difference in cardiac rhythm. Incidence of nonstructural dysfunction (paravalvular leak) was 0.2% for FS versus 1.3% for CE (p = 0.020).

CONCLUSIONS

By 5 years, the stentless valve patients had improved survival and reduced adverse events. Though differences in durability are yet to be proved, our findings support the use of stentless bioprostheses in this age group.

Mechanical bridge to recovery in fulminant myocarditis

A patient with acute fulminant lymphocytic myocarditis and cardiogenic shock was successfully treated by mechanical off loading of the left ventricle. A nonpulsatile left-heart bypass was undertaken with an implantable centrifugal blood pump. Careful weaning resulted in device removal on the seventh day. Left and right ventricular function is sustained at 7 months. Widespread application of this method depends on the availability of an inexpensive user friendly blood pump, appropriate weaning protocols and emerging strategies to promote sustainable myocardial recovery.

Aortic root geometry and stentless porcine valve competence

The goal of this study was to characterize medium-term changes in aortic root geometry after stentless aortic valve replacement, the relationship between aortic sinotubular junction and the competence of stentless valves. A total of 205 consecutive patients (mean age 73+/-6 years; 120 men, 85 women) received a Freestyle stentless porcine aortic valve and were studied prospectively by echocardiography from 1 week to 5 years. Internal diameters of outflow tract, annulus, sinus, sinotubular junction, and ascending aortic root were measured at early ejection and indexed to stentless valve size. The degree of stentless valve regurgitation was semiquantified by color Doppler echocardiography. A total of 701 echocardiographic studies were obtained and analyzed; 73% showed a fully competent stentless valve (nAR) and 13% and 14%, respectively, showed a trivial (tAR) or mild (mAR) regurgitation. Sinotubular junction of tAR or mAR was significantly greater than that of nAR (111+/-1.9, 117+/-2.2 vs. 104+/-1.0, percentage of valve size, P<.001). A preoperative diagnosis of aortic regurgitation (110+/-2.6 vs. 104+/-1.0, percentage of valve size, P<.001) and 4 to 5-year follow-up time (116+/-2.2 vs. 107+/-2.9, percentage of valve size, P = .023) were associated with a greater sinotubular junction, although the incidence and mean grade of stentless valve regurgitation did not change significantly during the follow-up period. Up to medium-term follow-up evaluation, the incidence of moderate stentless aortic regurgitation is less than 5%. The nature of valve disease and age-related increase in sinotubular junction may have reduced the cusp coaptation area of the stentless valve and may predict the presence of a trivial or mild regurgitation. Understanding the interrelations between the stentless valve and remodeling of the aging aorta has important implications for both surgical technique and long-term follow-up outcome.

The Sorin stentless pericardial valve: implant technique and hemodynamic profile

Stentless porcine xenografts have had significant impact on the hemodynamics, left ventricular remodeling, and survival after aortic valve replacement. We sought to establish a similar trend for the stentless pericardial valve. In a consecutive unselected series of 54 patients over 65 years of age, we refined the implant method for the stentless aortic pericardial valve and defined the pitfalls. We used a detailed echocardiographic study designed by the Food and Drug Administration to define the early valve hemodynamics and changes in left ventricular function. The valve is user friendly. With an easily reproducible implant technique, very low mean (7.1+/-3.4 mm Hg) and peak (13.6+/-6.3 mm Hg) transvalvular gradients were obtained, which did not decline significantly with time. Left ventricular mass index declined accordingly over 6 months (147+/-49 g/m2 to 125+/-39 g/m2). Mild aortic regurgitation, which did not influence left ventricular mass regression, occurred (26%) predominantly in the first half of the series because of size discrepancy between the annulus and a dilated sinotubular junction. Aortic regurgitation was virtually eliminated by tailoring of the sinotubular junction in the noncoronary sinus. The stentless pericardial valve provides excellent early hemodynamics and is a realistic alternative to the stentless porcine xenograft or aortic homograft for subcoronary aortic valve replacement in elderly patients. Valve durability is yet to be defined.

The effects of cardioplegia on coronary pressure-flow velocity relationships during aortic valve replacement

OBJECTIVE

The acute physiological response of the coronary circulation to aortic valve replacement (AVR) has not been fully elucidated. This study aimed to characterize the changes in coronary perfusion pressure-flow velocity relationships, and to test whether this relationship is affected by cardioplegic method.

METHODS

Nineteen patients (mean age 67 +/- 12 (SD) years, 9 males) undergoing aortic valve replacement who received either cold blood cardioplegia (CBC, n = 9) or warm blood cardioplegia (WBC, n = 10), were prospectively studied before and 30 min after the operation, using transesophageal Doppler echocardiography combined with high fidelity left ventricular (LV) and aortic pressures. We thus determined: (1) Diastolic flow velocities in proximal anterior descending coronary artery (LAD), and simultaneous aorta to LV pressure differences. (2) The slope (LAD proximal linear resistance) and pressure intercept (zero flow pressure) of this relationship. (3) Overall LAD linear resistance as the ratio of mean diastolic flow velocity to mean pressure difference between aorta and left ventricle. (4) LV myocardial stroke work.

RESULTS

Following operation, myocardial stroke work fell from 5.2 +/- 2.7 to 3.0 +/- 1.7, mJ cm(-3) (P = 0.001), LAD mean diastolic flow velocity increased from 47 +/- 19 to 74 +/- 21, cm s(-1) (P = 0.0002). LAD overall linear resistance fell (0.75 +/- 0.24 vs. 1.26 +/- 0.26, mmHg cm(-1) s, P = 0.001). LAD proximal linear resistance, however, remained unchanged (P = 0.21), but the zero flow pressure fell (18 +/- 12.6 vs. 27 +/- 12.2, mmHg above LV end diastolic pressure, P = 0.013). With similar fall in myocardial work postoperatively, there was a greater fall in zero flow pressure after WBC than CBC (48 +/- 28 vs. 19 +/- 13,% of pre-op, P = 0.012), and a greater increase in flow velocity time integral (127 +/- 81 vs. 53 +/- 59,%, P = 0.039).

CONCLUSION

Instantaneous diastolic LAD pressure-flow velocity relations in the early postoperative period can be explained more satisfactorily in terms of zero flow pressure and proximal linear resistance than simple resistance alone. The fall in zero flow pressure alone explains the increase in LAD flow velocity immediately after aortic valve replacement. The extent of this fall is greater after warm rather than cold blood cardioplegia.

Echocardiographic parameters of the freestyle stentless bioprosthesis in aortic position: the European experience

The objective of this study was to determine normal Doppler and 2-dimensional characteristics of the Freestyle stentless aortic bioprosthesis. The Freestyle aortic bioprosthesis is a new type of aortic xenograft, and experience is limited. We therefore determined the normal range of echocardiographic and Doppler examinations of this valve. Three hundred thirty-nine consecutive patients with a Freestyle aortic bioprosthesis underwent an echocardiographic and Doppler examination according to a common protocol. Investigations were done within 4 weeks after operation, after 3 to 6 months, and after 1, 2, and 3 years. With a valve size from 19 to 27 mm, mean gradients decreased from 7.9 +/- 5.1 mm Hg at discharge to 5.5 +/- 3. 8 mm Hg after 3 to 6 months (P <.001). Thereafter, gradients remained stable. Effective orifice area 1 year after implantation was 1.59 +/- 0.58 cm(2) for the 21-mm valves, 1.92 +/- 0.74 cm(2) for the 23-mm valves, 2.03 +/- 0.64 cm(2) for the 25-mm valves, and 2.52 +/- 0.72 cm(2) for the 27-mm valves (P <.001). The performance index, the ratio of the measured effective orifice area in the patient divided by the effective orifice area measured in vitro, increased from 67% +/- 20% at discharge to 82% +/- 29% after 1, 2, and 3 years. Performance index was especially very high in the smaller-sized valves. After implantation with the subcoronary technique or root-inclusion technique, small cavities could be seen between the native aortic root and the Freestyle valve. Doppler values were evaluated for the Freestyle stentless porcine bioprostheses in the aortic root. Gradients appear to be close to those measured in native valves over a time period of 3 years.

The relationship of myocardial stroke work to coronary flow velocity immediately after aortic valve replacement

BACKGROUND

The interrelations between myocardial stroke work and coronary flow velocity have not been fully defined during aortic valve replacement or with different cardioplegias.

METHODS

Twenty-six patients (15 men age 63+/-13 years) who had elective isolated aortic valve replacement were studied by transesophageal Doppler echocardiography with simultaneous high fidelity left ventricular pressure. Fifteen patients received cold blood cardioplegia and 11 had warm blood cardioplegia. Myocardial stroke work and flow velocities in proximal left anterior descending coronary artery were quantified simultaneously before cardiopulmonary bypass and at 1, 6, 12, and 20 hours afterwards.

RESULTS

Myocardial stroke work decreased postoperatively in both groups (160+/-19 versus 228+/-19 mJ/cm3 per minute, with cold blood cardioplegia; 135+/-22 versus 227+/-22 mJ/cm3 per minute with warm blood cardioplegia; both p<0.001 versus time, but p>0.05 versus cardioplegia, by two-way analysis of variance). Left anterior descending artery flow velocity-time integral per minute increased significantly in both groups (26.1+/-2.1 versus 15.0+/-2.1 m/min with cold blood cardioplegia; 32.8+/-2.5 versus 14.4+/-2.5 m/min with warm blood cardioplegia; both p<0.001 versus time, but p>0.05 versus cardioplegia). Thus, at 1 hour postoperatively the mJ x cm(-3) x m(-1) x min ratio of myocardial stroke work to left anterior descending artery flow velocity-time integral decreased significantly in both groups (4.3+/-1.6 versus 16.3+/-1.7 mJ x cm(-3) x m(-1) x min with warm blood cardioplegia, and 7.4+/-1.4 versus 17.9+/-1.4 J x cm(-3) x m(-1) x min with cold blood cardioplegia; both p<0.001 versus time). Warm blood cardioplegia was also associated with a lower mean ratio perioperatively than that with cold blood cardioplegia (7.8+/-0.9 versus 10.9+/-0.7 mJ x cm(-3) x m(-1) x min, p = 0.014).

CONCLUSIONS

Coronary hyperemia occurs for at least 20 hours postoperatively when myocardial stoke work has decreased. The ratio of myocardial stroke work to coronary flow velocity appears to be more sensitive than either alone in differentiating the effect of warm versus cold blood cardioplegia.

Medium-term determinants of left ventricular mass index after stentless aortic valve replacement

BACKGROUND

This study aimed to investigate the risk factors for elevated left ventricular mass index 3 to 5 years after stentless aortic valve replacement, and to elucidate the underlying physiologic mechanisms.

METHODS

Eighty-nine patients (age, 76 +/- 6 years, 51 males) having a stentless porcine valve for aortic stenosis (n = 76) or regurgitation (n = 13) were prospectively studied by Doppler echocardiography 3 to 5 years after operation. Left ventricular systolic function, mass index, blood pressure, cardiac rhythm, and New York Heart Association function class were all determined. Stentless valve effective orifice area, mean pressure drop, and the presence and degree of aortic regurgitation were quantified.

RESULTS

The mean stentless aortic valve size was 24 +/- 2 mm. At follow-up time of 45 +/- 9 months, effective orifice area index was 1.2 +/- 0.35 cm2 x m(-2), and mean pressure drop was 5.7 +/- 3.8 mm Hg. Left ventricular mass index was 128 +/- 47 g x m(-2), and ejection fraction was 63% +/- 14%. Multivariant analysis showed a greater left ventricular mass index to be associated with nonsinus rhythm (versus sinus) (163 +/- 8 versus 131 +/- 7 g x m(-2)), greater pulse pressure (> 84 mm Hg) (161 +/- 7 versus 133 +/- 7 g x m(-2)), New York Heart Association class II or III (versus class I) (166 +/- 10 versus 128 +/- 5 g x m(-2)), and male sex (versus female) (160 +/- 7 versus 134 +/- 8 g x m(-2)), all p < 0.01. Mean pressure drop (> 8 mm Hg), effective orifice area index (< 1.0 cm2 x m(-2)), the presence of mild regurgitation of the stentless valve, or the type of previous valve disease were insignificant determinants of left ventricular mass index.

CONCLUSIONS

Three to five years after the implantation, stentless aortic valve hemodynamics remain excellent. Left ventricular hypertrophy caused by previous native aortic valve disease had largely regressed. However, patient-related factors, particularly systemic blood pressure, cardiac rhythm, and function, are significant causes of late residual left ventricular hypertrophy. Thus, continued medical care and earlier surgical intervention may further improve the outlook for these patients.

Early changes in the time course of myocardial contraction after correcting aortic regurgitation

BACKGROUND

Correcting aortic regurgitation causes significant changes in left ventricular loading conditions, but few observations have been made intraoperatively of early effects on myocardial function.

METHODS

We studied 18 patients (mean age, 59+/-12 years; 14 men) in whom aortic regurgitation was corrected with a stentless biologic valve. Overall left ventricular function was studied by thermodilution cardiac output, ventricular filling pressure, and systemic arterial pressure. Regional myocardial function was assessed from intraoperative transesophageal M-mode echocardiography and high fidelity ventricular pressure recordings before cardiopulmonary bypass, and 0.5, 1, 3, 6, 12, and 20 hours after operation. Time course of contraction, and magnitude of left ventricular systolic wall stress, dimensional shortening, myocardial power, and stroke work were measured.

RESULTS

Global hemodynamics: there was an immediate decrease in left ventricular stroke volume (58+/-31 mL versus 80+/-30 mL, p = 0.004) and stroke work index (250+/-86 mJ/m versus 401+/-198 mJ/m, p = 0.005), but systemic arterial pressure (79+/-11 mm Hg versus 65+/-10 mm Hg, p = 0.002), increased at constant heart rate and end-diastolic pressure. Regional myocardial function and timing: peak systolic wall stress, dimensional shortening rate, and myocardial power production were all unchanged with operation. However, myocardial stroke work decreased (3.0+/-1.3 mJ/cm versus 4.8+/-2.4 mJ/cm, p = 0.009), attributable to shortening of the duration of systole (475+/-91 ms versus 543+/-67 ms, p<0.001). Diastolic time increased from 34%+/-18% to 71%+/-33% of systolic pulse duration (p<0.001).

CONCLUSIONS

Correcting aortic regurgitation causes an early decrease in regional and global stroke work and increases diastolic time, although systolic wall stress does not decrease immediately. These beneficial effects are achieved by reducing the duration rather than altering the peak intensity (power) of myocardial contraction.

Fifth-year hemodynamic performance of the prima stentless aortic valve

BACKGROUND

The medium-term hemodynamic performance of stentless valves has not been widely reported, particularly in comparison with in vitro studies. Therefore, we have assessed prospectively the hemodynamics of the Edwards Prima valve in its fifth year after implantation in the aortic position, and compared the results with those at 1 month after implantation and also with in vitro data.

METHODS

Thirty-five patients (age, 77 +/- 6 years; 19 men) were prospectively studied by Doppler echocardiography at 1 month and 52 +/- 8 months after implantation of a Prima stentless valve. Valve hemodynamics were assessed by measuring the mean pressure gradient, mean valve resistance, and effective orifice area. Left ventricular systolic function was quantified by ejection fraction, the degree of hypertrophy by ventricular mass index, and the ratio of ventricular wall thickness to cavity radius as a measure of ventricular geometry.

RESULTS

With a mean valve size of 24.6 +/- 2.2 mm in the fifth year after implantation, the mean pressure gradient was 6.2 +/- 3.5 mm Hg, the mean valve resistance, 29 +/- 16 dyne x s(-1) x cm(-5)), and the effective orifice area was 2.05 +/- 0.50 cm2. Compared with 1 month after operation, there was a 47% decrease in mean valve resistance (p = 0.002) and a 39% increase in effective orifice area (p = 0.001). Furthermore, both effective orifice area and mean valve resistance in the fifth year did not differ from their in vitro counterparts, whereas the left ventricular ejection fraction (0.64 +/- 0.14), the left ventricular mass index (119 +/- 49 g/m2), and the ratio of ventricular wall thickness to cavity radius (0.44 +/- 0.13) were within the normal range.

CONCLUSIONS

This study suggests that the Prima valve is a reliable stentless aortic bioprosthesis. This is supported by a favorable medium-term clinical outcome, durable hemodynamic performance, and normal mean values of left ventricular ejection fraction and mass index in the fifth year after implantation.

Valve replacement with a stentless bioprosthesis: versatility of the porcine aortic root

OBJECTIVE

Stentless valves convey important hemodynamic benefits but are used selectively depending on aortic root structure. The Freestyle valve (Medtronic, Inc, Minneapolis, Minn) is a versatile device that can be implanted by different methods depending on operating conditions. We aimed to demonstrate that a stentless valve could be used in every patient without increased risk of morbidity or mortality. We documented the effects of this valve on clinical outcome and left ventricular mechanics.

METHODS

The Freestyle valve was implanted by the modified subcoronary method into 200 consecutive unselected patients who received a tissue valve in the aortic position and by root replacement in 2. Forty-three percent were older than 75 years. Forty percent underwent coronary bypass. Detailed clinical and echocardiographic follow-up (Food and Drug Administration protocol) was used out to 3 years.

RESULTS

Mean ischemic time was 43+/-6 minutes for isolated aortic valve replacement and 63+/-14 minutes with concomitant procedures. Thirty-day mortality was 6%, none of the deaths being valve related. Hemodynamic function improved progressively with falling valve gradients and increased effective orifice areas. Left ventricular mass fell within normal limits over 2 years, but at 3 years there was a non-valve-related upswing. No instances of valve thrombosis, hemolysis, or paravalvular leak were noted. Less than 5% had mild to moderate aortic regurgitation.

CONCLUSIONS

The Freestyle valve can be used in virtually every patient with aortic valve disease and provides superlative hemodynamic outcome. Hospital mortality and morbidity are similar to those reported for stented valves in an elderly population.

Mechanical support in dilated cardiomyopathy: signs of early left ventricular recovery

BACKGROUND

Recent reports have documented left ventricular recovery in patients with dilated cardiomyopathy off-loaded long term with a left ventricular assist device. We sought to document the natural history of left ventricular recovery.

METHODS

We implanted the TCI left ventricular assist device without the intention to perform transplantation in 2 patients with dilated cardiomyopathy who had been rejected for transplantation. Both were in New York Heart Association functional class IV and had renal failure. One was a diabetic. We studied left ventricular function with detailed echocardiography at 4, 6, and 8 weeks postoperatively.

RESULTS

With the left ventricular assist device turned off, we observed a progressive increase in myocardial contractility beginning as early as 4 weeks after implantation and improving progressively. Histologic examination showed resolution of myocytolysis in both patients.

CONCLUSIONS

Left ventricular recovery begins earlier than was previously suspected. Mechanical bridge to myocardial recovery is a potential approach to therapy for such patients.

Coronary artery problems during homograft aortic valve replacement: role of transesophageal echocardiography

We describe 2 cases in which intraoperative transesophageal echocardiography detected complications related to the proximal coronary arteries during homograft aortic valve and root replacement. In both cases, cardiopulmonary bypass could not be discontinued despite the use of large doses of inotropic drugs. Transesophageal echocardiography demonstrated aliasing on color flow mapping in the left main coronary artery in 1 case and proximal right coronary artery in the other, along with severely depressed left ventricular anterior wall and right ventricular function, respectively. Coronary artery bypass grafting was performed in both cases, and the outcome was successful.