The effect of cyclic strain on embryonic stem cell-derived cardiomyocytes

Cardiomyocytes in the body are subjected to cyclic mechanical strain induced by the rhythmic heart beating. In this study, we tested the hypothesis that cyclic strain promotes cardiomyogenesis of embryonic stem cell-derived cardiomyocytes (ESCs). ESCs cultured on elastic polymer [poly(lactide-co-caprolactone), PLCL] scaffolds subjected to cyclic strain in vitro displayed elevated cardiac gene expression compared to unstrained controls. Six weeks after implantation into infarcted rat myocardium, the elastic cardiac patches (ESC-seeded PLCL scaffolds) showed reduced fibrotic tissue formation, likely due to a combination of lower apoptotic activity, higher vascular endothelial growth factor (VEGF) expression, and more extensive angiogenesis in the strained versus unstrained control [ESC-seeded, non-elastic poly(lactide-co-glycolide) scaffolds] patches. Importantly, cardiac gene expression was upregulated in the elastic patches compared to control, with evidence for cardiomyocyte-specific microstructures including myofibrillar bundles and Z-lines. This study shows that the use of an elastic polymer scaffold designed to permit mechanical strain transduction as a cell transplantation vehicle significantly increases cardiomyogenesis of the implanted ESCs.     

Comparison of tracheal reconstruction with allograft,fresh xenograft and artificial trachea scaffold in a rabbit model

This study evaluated the possibility of tracheal reconstruction with allograft, pig-to-rabbit fresh xenograft or use of a tissue-engineered trachea, and compared acute rejection of three different transplanted tracheal segments in rabbits. Eighteen healthy New Zealand White rabbits weighing 2.5–3.1 kg were transplanted with three different types of trachea substitutes. Two rabbits and two alpha 1, 3-galactosyltransferase gene-knockout pigs weighing 5 kg were used as donors. The rabbits were divided into three groups: an allograft control group consisting of rabbit-to-rabbit allotransplantation animals (n?=?6), a fresh xenograft group consisting of pig-to-rabbit xenotransplantation animals (n?=?6), and an artificial trachea scaffold group (n?=?6). All animals were monitored for 4 weeks for anastomotic complications or infection. The recipients were sacrificed at 28 days after surgery and the grafts were evaluated. On bronchoscopy, all of the fresh xenograft group animals showed ischemic and necrotic changes at 28 days after trachea replacement. The allograft rabbits and the tissue-engineered rabbits showed mild mucosal granulation. The levels of interleukin-2 and interferon-γ in the fresh xenograft group were higher than in other groups. Histopathologic examination of the graft in the fresh xenograft rabbits showed ischemic and necrotic changes, including a loss of epithelium, mucosal granulation, and necrosis of cartilaginous rings. The pig-to-rabbit xenografts showed more severe acute rejection within a month than the rabbits with allograft or artificial trachea-mimetic graft. In addition, the artificial tracheal scaffold used in the present experiment is superior to fresh xenograft and may facilitate tracheal reconstruction in the clinical setting.     

Myomectomy using purse-string suture during cesarean section

Background

Conventionally, myomectomy during cesarean section is reserved only for pedunculated myomas because resection of myomas at the time of cesarean section usually stimulates profuse bleeding.

Cases

Thirty-one patients underwent myomectomy using purse-string suture during cesarean section. Myoma could be excised without profuse bleeding, while an assistant maintains strong tension on the purse-string suture around the myoma. The suture was tightened and tied immediately after complete resection of the myoma and then stitches of another purse-string suture were placed alternately with each previous stitch in the inner side of the first suture. We have used this method for more than 3 years and have not observed failures and serious complications, such as late hemorrhage and uterine rupture during a subsequent pregnancy.

Conclusion

Myomectomy using purse-string suture during cesarean section is a safe, useful, and convenient technique.

     

ALDH1 and tumor infiltrating lymphocytes as predictors for neoadjuvant chemotherapy response in breast cancer

Many studies have reported that Aldehyde dehydrogenase 1 (ALDH1) and tumor-infiltrating lymphocytes (TIL) are related to breast cancer prognosis. However, the clinical significance of ALDH1 and tumor-infiltrating immune cells in breast cancer has not been fully investigated in patients who received neoadjuvant chemotherapy (NAC). We studied the significance of the expression of ALDH1 and the population of TIL for predicting the prognosis and chemotherapeutic response of patients with breast cancer who had received NAC. Forty patients who underwent NAC were enrolled in this study. ALDH1 and TIL (T cells and tumor associated macrophages) were evaluated before and after NAC. The influences of ALDH1 expression status and TIL populations on both prognosis and chemotherapeutic response were evaluated. ALDH1 positivity was related to estrogen receptor (p?=?0.026) and progesterone receptor negativity (p?=?0.025). Positive change of ALDH1 after NAC tended to be associated with a poor NAC response (p?=?0.078). Patients with more CD8+ T cells before NAC and fewer CD68 (+) macrophages after NAC tended to have better OS, respectively (p?=?0.086, p?=?0.096). The chemotherapeutic response and prognosis of patients with breast cancer who received NAC are thought to be determined by the tumor microenvironment. Further research with more patients and a longer study period is needed.     

Effect of ligamentum teres tear on the development of joint instability and articular cartilage damage: an in vivo rabbit study

The contribution of the ligamentum teres to the stabilization of the hip joint and the clinical influence of a compromised ligamentum teres are not well known. This study aimed to investigate joint stability and cartilage damage in a rabbit model by surgically inducing a complete ligamentum teres tear. Twenty adult New Zealand rabbits were used in this study. Rabbits were divided into complete ligamentum teres tear with capsulotomy (n = 9, group I) and capsulotomy only (n = 10, group II) groups. Unilateral surgery was performed on the left hip. Joint instability was assessed by measuring the preoperative and postoperative acetabulofemoral (A-F) distances. Rabbits were euthanized to assess cartilage damage at 24 weeks postoperatively. The median postoperative A-F distance of the operated side in group I [0.68 cm (0.37–1.04 cm)] was larger than that in group II [0.50 cm (0.30–0.65 cm)] (p = 0.041). The median postoperative A-F distance was larger in the operated side [0.68 cm (0.37–1.04 cm)] compared to the nonoperated side [0.45 cm (0.30–0.75 cm)] in group I; it also was larger in the operated side [0.50 cm (0.30–0.65 cm)] compared to the nonoperated side [0.44 cm (0.32–0.67 cm)] in group II, but only group I showed a significant difference (p = 0.016 and 0.395, respectively). Articular cartilage damage was detected at the apex of the femoral head in two rabbits (22.2%) in group I only. Rabbits with a complete ligamentum teres tear showed significant instability at the hip joint and articular cartilage damage in our rabbit model, supporting the potential clinical importance of ligamentum teres as a hip joint stabilizer.     

De novo missense variants in MEIS2 recapitulate the microdeletion phenotype of cardiac and palate abnormalities,developmental delay,intellectual disability and dysmorphic features

Gross deletions involving the MEIS2 gene have been described in a small number of patients with overlapping phenotypes of atrial or ventricular septal defects, cleft palate, and variable developmental delays and intellectual disability. Non‐specific dysmorphic features were noted in some patients, including broad forehead with high anterior hairline, arched eyebrows, thin or tented upper lip, and short philtrum. Recently, a patient with a de novo single amino acid deletion, c.998_1000delGAA (p.Arg333del), and a patient with a de novo nonsense variant, (c.611C>G, p.Ser204*), were reported with a similar, but apparently more severe phenotypes. Clinical whole exome sequencing (WES) performed at our clinical molecular diagnostic laboratory identified four additional patients with predicted damaging de novo MEIS2 missense variants. Our patients’ features closely resembled those previously reported in patients with gross deletions, but also included some less commonly reported features, such as autism spectrum disorder, hearing loss, and short stature, as well as features that may be unique to nucleotide‐level variants, such as hypotonia, failure to thrive, gastrointestinal, skeletal, limb, and skin abnormalities. All of the observed missense variants, Pro302Leu, Gln322Leu, Arg331Lys, and Val335Ala, are located in the functionally important MEIS2 homeodomain. Pro302Leu is found in the region between helix 1 and helix 2, while the other three are located in the DNA‐binding helix 3. To our knowledge, these are the first described de novo missense variants in MEIS2, expanding the known mutation spectrum of the newly recognized human disorder caused by aberrations in this gene.     

Change of erectile function and responsiveness to phosphodiesterase type 5 inhibitors at different stages of streptozotocin-induced diabetes in rats

IntroductionIt has been suggested that risk of erectile dysfunction (ED) increases with duration of diabetes and phosphodiesterase type 5 inhibitors (PDE5I) are not as effective in treatment of diabetes-associated ED. However, few studies have investigated time-dependent change in erectile function during the course of diabetes.AimTo investigate time-dependent change in erectile function and responsiveness to PDE5I in streptozotocin-induced diabetic rats and to understand the pathophysiology of diabetic ED.Main Outcome MeasuresAt 6, 8, 10, 12, and 14 weeks after diabetic induction, erectile function was assessed by cavernous nerve stimulation before and after administration of DA-8159, a novel PDE5I. Penile tissue was assessed for apoptosis with immunohistochemistry. Protein expression of Rho-kinase 2 (ROCK2), myosin phosphatase targeting subunit 1 (MYPT1), and endothelial nitric oxide synthase (eNOS) was evaluated by Western blot.MethodsStreptozotocin was injected into 50 8-week-old male Sprague-Dawley rats, which were then classified into five diabetic groups according to the observation period.ResultsDiabetic rats maintained normal erectile responses until 6 weeks of diabetes. Following 8 weeks, the rats showed lower erectile responses at higher frequencies of nerve stimulation, which were normalized to control by administration of DA-8159. In contrast, erectile responses were significantly decreased in 10-week diabetic rats, and administration of DA-8159 resulted in partial recovery of normal responses. At more than 12 weeks, rats demonstrated severe deterioration of erectile function, which did not fully respond to PDE5I. Corporal apoptosis was significantly increased after 10 weeks. Upregulation of ROCK2 was found at 6 weeks, and was followed by an increase of MYPT1 phosphorylation. Phosphorylation of eNOS showed marked suppression at 6 weeks and remained lower during the experimental period.ConclusionsImpairment of erectile function was followed by decreased responsiveness to PDE5I during the course of diabetes. The RhoA/ROCK pathway played an important role in diabetes-associated ED. Cho SY, Park K, Paick J-S, and Kim SW. Change of erectile function and responsiveness to PDE5 (Type 5 phosphodiesterase) inhibitors at different stages of streptozotocin-induced diabetes in rats.     

Prenatal diagnosis of short-rib polydactyly syndrome type 3 (Verma-Naumoff type) by three-dimensional helical computed tomography

We present a case of short-rib polydactyly syndrome (SRPs) type 3 in which accurate prenatal diagnosis was feasible using both ultrasonography and 3D-CT. SRP encompass a heterogeneous group of lethal skeletal dysplasias. However, the phenotypes overlap with those of nonlethal skeletal dysplasias (i.e. Ellis-van Creveld syndrome and Jeune syndrome). As accurate prenatal diagnosis of SRP is helpful for parents, we used 3D-CT in the early third trimester to examine a fetus suggested to have phenotypes of 'short-rib dysplasia group' on ultrasonography. 3D-CT showed mild modification of the vertebral bodies, small ilia with horizontal acetabula and triangular partial ossification defects, and subtle metaphyseal irregularities of the femora. These CT findings and an extensive literature search regarding the phenotypes of various diseases categorized as short-rib dysplasia group led to a correct prenatal diagnosis of SRP type 3. This case exemplified the usefulness of 3D-CT for the precise prenatal diagnosis of skeletal dysplasias.     

The suppression of lung tumorigenesis by aerosol-delivered folate–chitosan-graft-polyethylenimine/Akt1 shRNA complexes through the Akt signaling pathway

RNA interference (RNAi) represents a promising new approach to the inhibition of gene expression in vitro and in vivo, and has therapeutic potential for human diseases. Efficient delivery of small interfering RNA (siRNA) or small hairpin RNA (shRNA) is a critical concern in RNAi studies. Here we report the development of a new polymeric gene carrier for cancer cell-targeting, designed to enhance the intracellular delivery of shRNA and reduce cytotoxicity. Folate–chitosan-graft-polyethylenimine (FC-g-PEI) copolymer was prepared by an imine reaction between periodate-oxidized folate–chitosan (FC) and low molecular weight polyethylenimine (PEI). FC-g-PEI copolymer was investigated as a potential cancer cell-targeting gene carrier. The composition of FC-g-PEI was characterized using ¹H nuclear magnetic resonance (¹H NMR), and particle size and zeta potential of FC-g-PEI/shRNA complexes were measured using dynamic light scattering (DLS). FC-g-PEI showed good shRNA condensation ability and high protection of shRNA from nuclease attack. It also exhibited lower cytotoxicity compared to PEI 25K control, and showed good cancer cell-targeting ability. Furthermore, aerosol delivery of FC-g-PEI/Akt1 shRNA complexes suppressed lung tumorigenesis in a urethane-induced lung cancer model mouse through the Akt signaling pathway. Together, these results suggest that FC-g-PEI may be useful for shRNA-based gene therapy.