Direct determination of spin-orbit interaction coefficients and realization of the persistent spin helix symmetry

The spin-orbit interaction plays a crucial role in diverse fields of condensed matter, including the investigation of Majorana fermions, topological insulators, quantum information and spintronics. In III-V zinc-blende semiconductor heterostructures, two types of spin-orbit interaction--Rashba and Dresselhaus--act on the electron spin as effective magnetic fields with different directions. They are characterized by coefficients α and β, respectively. When α is equal to β, the so-called persistent spin helix symmetry is realized. In this condition, invariance with respect to spin rotations is achieved even in the presence of the spin-orbit interaction, implying strongly enhanced spin lifetimes for spatially periodic spin modes. Existing methods to evaluate α/β require fitting analyses that often include ambiguity in the parameters used. Here, we experimentally demonstrate a simple and fitting parameter-free technique to determine α/β and to deduce the absolute values of α and β. The method is based on the detection of the effective magnetic field direction and the strength induced by the two spin-orbit interactions. Moreover, we observe the persistent spin helix symmetry by gate tuning.

Two-stage laparoscopic treatment for strangulated inguinal, femoral and obturator hernias: totally extraperitoneal repair followed by intestinal resection assisted by intraperitoneal laparoscopic exploration

PURPOSE

Total extraperitoneal preperitoneal (TEP) repair is widely used for inguinal, femoral, or obturator hernia treatment. However, mesh repair is not often used for strangulated hernia treatment if intestinal resection is required because of the risk of postoperative mesh infection. Complete mesh repair is required for hernia treatment to prevent postoperative recurrence, particularly in patients with femoral or obturator hernia.

CASES

We treated four patients with inguinocrural and obturator hernias (a 72-year-old male with a right indirect inguinal hernia; an 83-year-old female with a right obturator hernia; and 86- and 82-year-old females with femoral hernias) via a two-stage laparoscopic surgery. All patients were diagnosed with intestinal obstruction due to strangulated hernia. First, the incarcerated small intestine was released and then laparoscopically resected. Further, 8-24 days after the first surgery, bilateral TEP repairs were performed in all patients; the postoperative course was uneventful in all patients, and they were discharged 5-10 days after TEP repair. At present, no hernia recurrence has been reported in any patient.

CONCLUSION

The two-stage laparoscopic treatment is safe for treatment of strangulated inguinal, femoral, and obturator hernias, and complete mesh repair via the TEP method can be performed in elderly patients to minimize the occurrence of mesh infection.

Maternal high-fat diet alters anxiety behavior and glucocorticoid signaling in adolescent offspring

Maternal obesity and overconsumption of saturated fats during pregnancy have profound effects on offspring health, ranging from metabolic to behavioral disorders in later life. The influence of high-fat diet (HFD) exposure on the development of brain regions implicated in anxiety behavior is not well understood. We previously found that maternal HFD exposure is associated with an increase in anxiety behavior and alterations in the expression of several genes involved in inflammation via the glucocorticoid signaling pathway in adult rat offspring. During adolescence, the maturation of feedback systems mediating corticosteroid sensitivity is incomplete, and therefore distinct from adulthood. In this study, we examined the influence of maternal HFD on several measures of anxiety behavior and gene expression in adolescent offspring. We examined the expression of corticosteroid receptors and related inflammatory processes, as corticosteroid receptors are known to regulate circulating corticosterone levels during basal and stress conditions in addition to influencing inflammatory processes in the hippocampus and amygdala. We found that adolescent animals perinatally exposed to HFD generally showed decreased anxiety behavior accompanied by a selective alteration in the expression of the glucocorticoid receptor and several downstream inflammatory genes in the hippocampus and amygdala. These data suggest that adolescence constitutes an additional period when the effects of developmental programming may modify mental health trajectories.

62 EFFECTS OF VARYING GLUTATHIONE CONCENTRATIONS IN SEMEN EXTENDER ON THE QUALITY OF FROZEN–THAWED CANINE SPERM

Trans-cervical insemination (TCI) with cryopreserved semen offers a potentially effective approach for breeding canids with specific genetic traits, such as guide dogs for the blind. However, there are technical difficulties in canine sperm cryopreservation, such as the composition of semen extender. The aim of this study was to evaluate the effects of glutathione (GSH) as an antioxidant in the semen extender to improve the quality of frozen-thawed dog sperm. A Tris-egg yolk-citrate extender containing 15.7 mg mL–1 of TRIS, 8.8 mg mL–1 of citric acid, 14.1 mg mL–1 of lactose, 25.4 mg mL–1 of raffinose, 1% (vol/vol) antibiotics, and 20% (vol/vol) egg yolk in ultra-pure water was used as the base medium. Twelve ejaculates were collected from 7 dogs. Each ejaculate was divided into 2 to 5 aliquots and extended with base extender supplemented with 0, 2.5, 5, 7.5, and 10 mM GSH as first dilution. The extended semen was equilibrated for 3 h at 4°C. An equal volume of second extender was added to obtain a final concentration of 6.5% glycerol and sperm per milliliter. The sperm samples were loaded in straws and frozen at 6 cm above the surface of LN2 for 15 min in a styrene foam box and plunged into the LN2. The frozen semen was thawed for evaluation. The motility of sperm was estimated with a phase-contrast microscope and the motile patterns were classified into the following grades: progressively motile at a high speed (+++), progressively motile at a moderate and low speed (++), motile without progression (+), and immotile (–). Then, the sperm motility index (SMI) was determined from the following formula as described previously (Iritani et al., 1975), with some modifications: the percentage of (+++) sperm + the percentage of (++) sperm × 0.75 + the percentage of (+) sperm × 0.5. Sperm motility and the SMI were determined at 0, 1, 2, 3, 4, 12, and 24 h after thawing. Acrosome status was evaluated at 4 h after thawing. Lipid peroxidation (LP) levels at 0 and 12 h after thawing were used to examine the antioxidant ability of GSH. Trans-cervical insemination was carried out on 5 bitches to evaluate the fertility of GSH-treated sperm. The TCI were performed nonsurgically with a laparoscope and deposited 2 mL of semen through a catheter. Each bitch was inseminated 1 to 2 times during oestrus. Data were analysed using ANOVA with the Tukey-Kramer method. We found that the rate of (+++) sperm in the 5 mM GSH group was higher than that in the 0 mM group from 1 to 24 h after thawing (P < 0.05). The SMI was higher in the 5 and 7.5 mM GSH groups than in the 0 mM group (P < 0.05). There were no significant differences in the control and 2.5 and 10 mM GSH groups. Long-term survival was increased in the 5 mM GSH group. Acrosome integrity was higher in the GSH-treated group. The level of LP was lower in the GSH-treated groups at 0 h after thawing (P < 0.05). Trans-cervical insemination with the 5 mM GSH-treated semen resulted in the delivery of 5 pups from 2 bitches. These results indicate that the cryopreservation with 5 mM GSH can improve the motility, viability, and fertility of frozen-thawed canine sperm by its antioxidant effects on the sperm membrane.

Proteomics-based identification of novel proteins in temporal tendons of patients with masticatory muscle tendon--aponeurosis hyperplasia

Masticatory muscle tendon-aponeurosis hyperplasia (MMTAH) is a new disease associated with limited mouth opening that is often misdiagnosed as a temporomandibular disorder; subsequently, patients are mistakenly treated with irreversible operations. Due to the poor presentation and characterization of symptoms, the underlying pathological conditions remain unclear. We have previously conducted a proteomic analysis of tendons derived from one MMTAH subject and one facial deformity subject using two-dimensional fluorescence difference gel electrophoresis and liquid chromatography coupled with tandem mass spectrometry. However, the results were obtained for only one subject. The aim of the present study was to confirm the expression of specific molecules in tendon tissues from multiple subjects with MMTAH by applying two-dimensional polyacrylamide gel electrophoresis with matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Of the 19 proteins identified in tendons from both MMTAH and facial deformity patients, fibrinogen fragment D and beta-crystallin A4 were up-regulated, whereas myosin light chain 4 was down-regulated in MMTAH. We also found fibrinogen to be expressed robustly in tendon tissues of MMTAH patients. Our data provide the possibility that the distinctive expression of these novel proteins is associated with the pathology of MMTAH.

Constitutively and highly expressed Oryza sativa polyamine oxidases localize in peroxisomes and catalyze polyamine back conversion

Polyamine oxidases (PAOs) are FAD-dependent enzymes involved in polyamine (PA) catabolism. Recent studies have revealed that plant PAOs are not only active in the terminal catabolism of PAs as demonstrated for maize apoplastic PAO but also in a polyamine back-conversion pathway as shown for most Arabidopsis PAOs. We have characterized Oryza sativa PAOs at molecular and biochemical levels. The rice genome contains 7 PAO isoforms that are termed OsPAO1 to OsPAO7. Of the seven PAOs, OsPAO3, OsPAO4, and OsPAO5 transcripts were most abundant in 2-week-old seedlings and mature plants, while OsPAO1, OsPAO2, OsPAO6, and OsPAO7 were expressed at very low levels with different tissue specificities. The more abundantly expressed PAOs--OsPAO3, OsPAO4, and OsPAO5--were cloned, and their gene products were produced in Escherichia coli. The enzymatic activities of the purified OsPAO3 to OsPAO5 proteins were examined. OsPAO3 favored spermidine (Spd) as substrate followed by thermospermine (T-Spm) and spermine (Spm) and showed a full PA back-conversion activity. OsPAO4 substrate specificity was similar to that of OsPAO5 preferring Spm and T-Spm but not Spd. Those enzymes also converted Spm and T-Spm to Spd, again indicative of PA back-conversion activities. Lastly, we show that OsPAO3, OsPAO4, and OsPAO5 are localized in peroxisomes. Together, these data revealed that constitutively and highly expressed O. sativa PAOs are localized in peroxisomes and catalyze PA back-conversion processes.

Highly fluorescent 5-(5,6-dimethoxybenzothiazol-2-yl)-2'-deoxyuridine 5'-triphosphate as an efficient substrate for DNA polymerases

We herein describe the synthesis of fluorescent 5-(5,6-dimethoxybenzothiazol-2-yl)-2'-deoxyuridine 5'-triphosphate (d(bt)UTP) and primer extension reactions using d(bt)UTP. We also carried out primer extension reactions using the (bt)U template. B family DNA polymerases, such as KOD, Deep Vent (exo-), and 9°N(m) DNA polymerases, were effective for elongation with d(bt)UTP. Deep Vent (exo-) and KOD DNA polymerases have excellent fidelity for incorporating d(bt)UTP only at the site opposite the adenine template and only dATP when using the (bt)U template. Therefore, d(bt)UTP is an excellent fluorescent nucleotide that can be incorporated into DNA by DNA polymerases.

Laparoscopy-assisted appendectomy through an umbilical port in children

INTRODUCTION

We report surgical techniques for single-incision laparoscopy-assisted surgery (SILAS) in the treatment of pediatric acute appendicitis.

METHODS

We performed SILAS in 15 cases of acute appendicitis between January and September of 2009. SILAS is a surgical method that involves making the incision at the umbilicus, inserting a wound retractor XS, suspending the abdominal wall with a hook, and appendectomy with the same procedures as conventional appendectomy.

RESULTS

SILAS appendectomy was performed in all 15 cases with the exception of one case where one 3-mm port was added. Compared to open appendectomy, blood loss was significantly lower and postoperative hospitalization time was shorter, although there was no significant decrease in operative time, or postoperative fasting time. No postoperative complications, such as wound infection, intestinal obstruction, intra-abdominal abscess, or bleeding, were encountered.

CONCLUSION

SILAS was safely performed and is superior to open appendectomy with regard to cosmetic outcome.

Laparoscopic Heller myotomy with Dor fundoplication for achalasia: long-term outcomes and effect on chest pain

The aim of the present study was to evaluate the long-term outcomes of laparoscopic Heller myotomy with Dor fundoplication (LHD) and its effect on chest pain. Between June 1995 and August 2009, a total of 35 patients with achalasia underwent an LHD. The symptom scores were calculated by combining the frequency and the severity. Pre- and postoperative evaluations included symptom score, radiology, manometry, and 24-hour pH manometry. Median total symptom score was significantly lower than the preoperative score (19 vs 4, P < 0.001) at a median follow-up of 94 months. Among the 35 patients, 18 (51%) had chest pain. The frequency of chest pain was similar for the pre- and postoperative scores, but the severity tended to be less. Median esophageal diameter (5.4 cm vs 3.5 cm, P < 0.001) and lower esophageal sphincter pressure (41 mmHg vs 8.9 mmHg, P < 0.001) were significantly reduced after surgery. Median age, duration of symptoms, esophageal diameter, and lower esophageal sphincter pressure were similar between patients with and without chest pain prior to surgery. No significant differences were observed between the two groups in terms of amplitude, duration, and frequency of contractions from the findings of postoperative 24-hour esophageal manometry. Chest pain resolved in three patients (17%) and improved in seven patients (39%) after surgery. LHD can durably relieve achalasic symptoms of both dysphagia and regurgitation, and it can be considered the surgical procedure of choice. However, achalasic chest pain does not always seem to be related with patient characteristics and manometric findings.

Development and single laboratory validation of a method for citrinin

Citrinin (CIT) is a nephrotoxic secondary metabolite produced by several fungal species. CIT contamination has been reported in many cereals. Recently CIT contamination of red mold rice, used as an artificial colour, received attention because a CIT producing Monascus species was used in its production. Therefore, we developed a relatively simple method, immunoaffinity column clean-up followed by high performance liquid chromatographic (IAC-HPLC) detection, to determine CIT in red mold rice and several other commodities, and performed a single laboratory validation of the method. CIT was extracted by shaking for 30 min with 70% methanol, after which the extract was purified using an immunoaffinity column. The isolated CIT was quantitated by HPLC with fluorescence detection. Recoveries of CIT from red mold rice and koji-rice at levels of 50-2,500 µg/kg were 81-88%. RSDs, estimated with naturally contaminated red mold rice at 50, 200 and 400 µg/kg were 5.1%, 2.8% and 4.1%, respectively. Recoveries of CIT from cereals and mushroom samples at 50, 200 and 400 µg/kg were 60-123%, 69-88% and 73-100% with RSDs of 2.1-7.8%, 1.7-9.2% and 0.6-5.3%, respectively.