Modern precipitation of hydrogenetic ferromanganese minerals during on-site 15-year exposure tests.

Redox-sensitive metallic elements, Mn and Fe, are oxidized in deep sea waters and form abundant ferromanganese crusts and nodules on the world's ocean floors at ultraslow rates of growth. This process of oxidation and the mechanism of precipitation are yet unknown. In this paper, the results of the first successful, long-term, on-site experiment of mineral precipitation that ascertains modern, ongoing hydrogenetic deposition of oxide materials from normal seawaters at water depths of 900-4500 m of geologically active and inactive environments are presented. We succeeded in the in-situ precipitation experiment on the sea floor and characterized the precipitates using high-resolution and submicron-scale chemical, mineralogical, and structural analyses. The installed artificial plates of glass, ceramics, and plastic yielded spread-out particles of sizes varying from one to a few micrometers in diameter, of coccoid-like irregular shapes, with a maximum of 1,000-10,000 individual particles/mm2/year after 12-15 years of exposure. The results indicated a continuous substantial growth of the hydrogenetic minerals if both Mn and Fe are supplied to the bottom waters. The mineralogical, chemical, and structural properties of the precipitates are similar to those of the natural precipitates on the seabed that are made up of hydrogenetic ferromanganese crusts and nodules, together with settling sediments, suspended hydrothermal particles, or microbial precipitates from cultivated Mn-oxidizing bacteria. Our work presents new realistic insight into proposed genetic models of marine hydrogenetic ferromanganese deposits in modern diverse ocean environments.

Evaluation of circadian phenotypes utilizing fibroblasts from patients with circadian rhythm sleep disorders.

We evaluated the circadian phenotypes of patients with delayed sleep-wake phase disorder (DSWPD) and non-24-hour sleep-wake rhythm disorder (N24SWD), two different circadian rhythm sleep disorders (CRSDs) by measuring clock gene expression rhythms in fibroblast cells derived from individual patients. Bmal1-luciferase (Bmal1-luc) expression rhythms were measured in the primary fibroblast cells derived from skin biopsy samples of patients with DSWPD and N24SWD, as well as control subjects. The period length of the Bmal1-luc rhythm (in vitro period) was distributed normally and was 22.80±0.47 (mean±s.d.) h in control-derived fibroblasts. The in vitro periods in DSWPD-derived fibroblasts and N24SWD-derived fibroblasts were 22.67±0.67 h and 23.18±0.70 h, respectively. The N24SWD group showed a significantly longer in vitro period than did the control or DSWPD group. Furthermore, in vitro period was associated with response to chronotherapy in the N24SWD group. Longer in vitro periods were observed in the non-responders (mean±s.d.: 23.59±0.89 h) compared with the responders (mean±s.d.: 22.97±0.47 h) in the N24SWD group. Our results indicate that prolonged circadian periods contribute to the onset and poor treatment outcome of N24SWD. In vitro rhythm assays could be useful for predicting circadian phenotypes and clinical prognosis in patients with CRSDs.

Low-dose hyperthermia enhances the antitumor effects of chemotherapy in squamous cell carcinoma.

Esophageal squamous cell carcinoma is a highly aggressive neoplasm and the sixth leading cause of global cancer-related death; the 5-year survival rate for esophageal cancer is only about 20%-25% for all stages. Therefore, improving the therapeutic effect is important. This study assessed whether low-dose hyperthermia (LDH) enhances the antitumor effects of chemotherapy. The antitumor effect of chemotherapy with/without LDH in the squamous cell carcinoma cell line SCCVII was evaluated. A comprehensive analysis was performed with real-time polymerase chain reaction (PCR) to study the hyperthermia-induced changes in the gene expression of SCCVII cell lines. In addition, the cytotoxic and apoptotic changes in the cells treated with LDH combined with/without 5-fluorouracil (5-FU) were measured. LDH combined with 5-FU (10 nM) strongly inhibited the cell growth of SCCVII, with flow cytometry showing an increased population of apoptotic cells. PCR showed that LDH promoted a 25.22-fold increase of p53 mRNA and 18.08-fold increase of Bax mRNA in vitro. MDR1 expression was decreased to 28.7% after LDH. This treatment can result in much higher efficacy of antitumor drugs. After LDH, the expressions of TS decreased to 12.06%, OPRT increased by 4.17-fold, and DPD did not change (1.03-fold). This transformations will induce susceptibility to 5-FU. LDH may be a useful enhancer of chemotherapy drugs for squamous cell carcinoma.

[The strategy for aortic root reconstruction; Bentall operation or native valve preserving operation?].

Bentall operation has been a gold-standard procedure for the aortic root reconstruction in the patients with aortic root aneurysms and aortic valve insufficiency (AI). Recently, native aortic valve preserving operation has been widely spread. In this study, we described the results of aortic root reconstruction in our institution and evaluated our operative methods. We selected Bentall operation for severely damaged or cardiac redo cases, and David operation for simple annuloaortic ectasia and AI. Recently, we have utilized Valsalva graft which provides the advantage of capability of larger prosthetic valve implantation and better hemodynamic performance.

Evidence for two Mg related acceptors in GaN.

The optical signatures of Mg-related acceptors in GaN have been revisited in samples specifically grown on bulk GaN templates, to avoid strain broadening of the optical spectra. Bound-exciton spectra can be studied in these samples for Mg concentrations up to [Mg] approximately 2 x 10(19) cm(-3). Contrary to previous work it is found that instabilities in the photoluminescence spectra are not due to unstable shallow donors, but to unstable Mg-related acceptors. Our data show that there are two Mg-related acceptors simultaneously present: the regular (stable) substitutional Mg acceptor, and a complex acceptor which is unstable in p-GaN.

[Surgical treatment for aortic root dilatation and aortic regurgitation after arterial switch operation].

Aortic regurgitation (AR) and, aortic root dilatation are serious problems occurring after arterial switch operation (ASO). We have experienced a case of 12-year-old boy with aortic root dilatation and AR after ASO. Consistent progression of AR and aortic root dilatation were observed during the follow-up period. The latest Z-score of Valsalva sinus was about 9. We performed the Bentall procedure instead of aortic valve-sparing operation because of the degenerative aortic valve and the excessive aortic root dilatation. The postoperative course was uneventful. Histopathological findings of the aortic wall showed degeneration of elastic fibers on both sides of the anastmosis.

[Coronary artery anastomosis using a cloth graft-holder attached to a stabilizer].

Numerous assist devices are usually used for coronary bypass grafting but they make the surgical field cluttered. This study proposes the use of a simple anastomotic method using a cloth graft-holder, which can be attached to a stabilizer. A graft is held between a double-folded cloth of a graft-holder and the graft-holder is attached to the stabilizer using double-stick tape, which provides steady positioning of the graft even in an up-right position. The graft can be positioned parallel with a coronary artery on either side of the stabilizer. The presented method provides a simplified and orderly surgical field without complicated devices and should help achieve a uniform and steady coronary anastomosis.

Resonant light delay in GaN with ballistic and diffusive propagation.

We report on a strong delay in light propagation through bulk GaN, detected by time-of-flight spectroscopy. The delay increases resonantly as the photon energy approaches the energy of a neutral-donor bound exciton (BX), resulting in a velocity of light as low as 2100 km/s. In the close vicinity of the BX resonance, the transmitted light contains both ballistic and diffusive components. This phenomenon is quantitatively explained in terms of optical dispersion in a medium where resonant light scattering by the BX resonance takes place in addition to the polariton propagation.

[Surgical repair of traumatic rupture of the discending aorta through 'L'-thoracotomy].

Acute blunt aortic rupture occurs frequently at the aortic isthmus and emergency operation is usually required. A 33-year-old man was suffered with blunt traumatic thoracic aortic injury caused by traffic accident and emergency operation was performed due to hemodynamic instability. The patient was operated through 'L'-thoracotomy (upper part sternotomy and antero-lateral thoracotomy). Cardiopulmonary bypass was initiated with right femoral vein drainage and right femoral arterial return and converted to standard cardiopulmonary bypass with the ascending aorta return and right atrium appendage drainage when the discending aorta was re-ruptured. It stabilized the circulation of upper body, especially brain. The post-operative course was uneventful. The 'L'-thoracotomy can provide good operative exposure for the aortic isthmus and stabilize the circulation of the brain with standard cardiopulmonary bypass and clamping the descending aorta.

[Aortic valve replacement for the small aortic annulus].

Aortic valve surgery for the small aortic annulus is still challenging for surgeons. Recently, the new types of high performance prosthesis have been developed and the chance of an aortic root enlargement (ARE) is decreasing. In this study, we propose the ideal strategy of the aortic surgery for the small aortic annulus. We analyzed the clinical records of 158 patients who underwent aortic valve replacement from August 1999 to October 2005 in our institution. The small aortic annulus was observed in 38 patients (24%). Fourteen patients of this group underwent ARE. Patient-prosthesis mismatch (PPM) was less frequently observed in patients with ARE compared to those without ARE. The additional time required for ARE was not considerable, and neither ischemic time nor cardiopulmonary bypass time was significantly prolonged by ARE. In conclusion, we have to select a prosthesis with sufficient orifice area to avoid PPM, otherwise we should choose an option of ARE. For this consideration, we definitely need the chart that demonstrates the relationship between the nominal size of various types of prostheses and the size of a patient's annulus that those prostheses actually fit.

[Surgery for acute aortic dissection concomitant with preceding axillofemoral bypass to prevent malperfusion of visceral organs and limb ischemia].

A 52-year-old man was admitted with sudden onset of epigastralgia. Abdominal X-ray showed dilated intestine and computed tomography (CT) revealed extended type A aortic dissection. Marked abdominal distention and weak pulse of right femoral artery were recognized so malperfusion of visceral organs due to narrowing true lumen compressed by thrombosed false lumen was suggested. In the operation, right axillo-right femoral bypass was established preceding to median sternotomy. This graft was used as an arterial perfusion site of cardiopulmonary bypass, and replacement of the ascending aorta was performed under hypothermic circulatory arrest and retrograde cerebral perfusion. Sign of malperfusion of visceral organs was showed for several days after the operation but it disappeared without further intervention. Axillofemoral inflow of cardiopulmonary bypass may be effective procedure in these cases.

Plasma orexin-A is lower in patients with narcolepsy.

Recently identified hypothalamic peptides called orexins (or hypocretins) have been implicated in the sleep-wake cycle and in sleep disorder narcolepsy. Neuropathological studies have shown that in patients with narcolepsy, global reduction in the expression of orexins occurs due to the loss of orexin neurons in the hypothalamus. Cerebrospinal fluid analysis has confirmed a reduced or undetectable level of orexin-A in most narcolepsy patients. In this study, measurement of plasma orexin showed significantly lower concentrations in patients with narcolepsy than in age- and gender-matched normal controls. These data suggest that low levels of orexin-A in plasma could serve as a biological marker for narcolepsy.

Giant vegetation mimicking cardiac tumor in tricuspid valve endocarditis after catheter ablation.

A 33-year-old man suffered from fever of unknown origin and developed right-sided heart failure. A transeshophageal echocardiogram revealed an progressive enlarging mass in the right atrium mainly attached to the tricuspid valve and a previous ablation site, which mimicked a cardiogenic tumor. He was operated on to remove the mass and intraoperative pathology showed it was large vegetation and secondary granulation due to tricuspid endocarditis. Tricuspid valve replacement was performed combined with reconstruction of the right atrial wall.

Evaluation of antibody class in response to endoscopic subureteral collagen injection in patients with vesicoureteral reflux.

PURPOSE: Clinical problems after glutaraldehyde cross-linked collagen injection for vesicoureteral reflux are the appearance of anticollagen antibodies and a decrease in collagen with time. We evaluated whether antibody production affects reflux recurrence and implanted collagen absorption. MATERIALS AND METHODS: We treated 27 patients (39 ureters) who had vesicoureteral reflux with endoscopic subureteral glutaraldehyde cross-linked collagen injection. The maximum diameter of the elevated ureteral orifice was measured 3-dimensionally and the numerical value calculated by multiplying each diameter by approximately pi/6 was used as the ultrasound estimate of injected collagen volume. The 1-to-6-month collagen volume ratio was used as an index of the decrease in implant collagen volume. The antibody class against bovine collagen was characterized by indirect enzyme-linked immunosorbent assay. RESULTS: Seroconversion in 6 patients was noted a mean 6.8 months after the first injection. In these patients the antibody class was IgG dominant and IgA or IgM was not detected. There was no significant difference in the total injected collagen volume, total number of injections or collagen volume ratio in the seropositive and seronegative groups. Reflux recurred in 4 patients and the curve of the reflux-free rate was similar regardless of antibody appearance. CONCLUSIONS: The immune response to bovine collagen injection for vesicoureteral reflux does not depend on injected collagen volume or an increased number of treatments. Antibody production had no effects on absorption of the implanted collagen or reflux recurrence.

Dislocation propagation in GaN films formed by epitaxial lateral overgrowth

We have investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) the relationship between surface morphological evolution and dislocation propagation in GaN films formed by epitaxial lateral overgrowth (ELO) in hydride vapour phase epitaxy. The SEM observations revealed that step and terrace structures were formed on (0001) surfaces of the films both in the earlier and the later stages of growth, suggesting the occurrence of step-flow growth during ELO. Bending dislocations with laterally propagated segments were frequently observed in the ELO films and their morphology led to a reduction in threading dislocation density in the film surface regions. Systematic TEM observations were performed to reveal the detailed structure of the bending dislocations. Comparison between the SEM and the TEM results showed that the lateral propagation of the dislocation was closely related to the appearance of the [1101) facets. A mechanism for dislocation propagation is discussed that explains the observed dislocation structure and surface step morphology.

Clinical results of implantation of an endovascular covered stent-graft via midsternotomy for distal aortic arch aneurysm.

UNLABELLED: We have been implanting endovascular stent grafts (EVG) via midsternotomy for distal aortic arch surgery since February 1997. The early clinical results are evaluated. METHODS: There were 11 true aneurysms (8 fusiform, 3 saccular) and one chronic type B dissection. The average age was 68 yr (63-81). EVGs were PTFE-covered two-8 bend Z stents in the first eight cases and made with the same stents and ultrathin woven Dacron grafts in the last four cases. RESULTS: Total arch replacement and aortocoronary bypass grafting were combined in one and two patients, respectively. The average retrograde cerebral perfusion time was 42+/-8 min. The cardiopulmonary bypass time averaged 211+/-26 min. All patients awoke early after operation (4.5+/-1.2 h). All but one case was extubated within 24h. There was no operative mortality, but paraplegia and cerebral infarction were complicated in one case each. Their maximum diameter (73.9+/-21.2mm) decreased significantly after operation (68.7+/-20.1mm) and one year thereafter (63.1+/-16.0 mm). True aneurysms were thrombosed completely. A chronic type B dissection revealed impending rupture due to false lumen infection one year after operation. The whole descending aorta replacement was performed but the patient died 6 months thereafter due to cerebro-vascular complication. CONCLUSION: Implantation of EVGs reduces operative invasion for distal arch surgery. This procedure should improve mortality, while long-term results have not been clarified.

The endothelin-2/vasoactive intestinal contractor gene: expression and promoter activity in PC12 rat pheochromocytoma cells.

In order to understand the physiological roles of vasoactive intestinal contractor (VIC)/endothelin-2 (ET-2), we examined the expression of this peptide by specific reverse transcriptase polymerase chain reaction (RT-PCR) analysis and found that PC12 rat pheochromocytoma cells express the VIC gene. The 5'-flanking 1.0 kilo base pair (kb) region of the mouse VIC gene is sufficient to express a secreted alkaline phosphatase (SEAP) reporter gene in transiently transfected PC12 cells. The 1.0 kb promoter region may contain cis-acting elements that determine the rate of the VIC gene transcription in PC12 cells.

Detection of interstitial Ga in GaN

We report the direct detection of interstitial Ga by optical detection of electron paramagnetic resonance (ODEPR) in the photoluminescence of n-type GaN after irradiation in situ at 4.2 K with 2.5 MeV electrons. It is stable upon annealing until room temperature, where it becomes mobile and trapped to form a new defect which is observed to emerge as the interstitial disappears. The time constant of the process at room temperature is approximately 200 min. The emergence of another ODEPR center beginning at approximately 135 K suggests even easier migration of one of the other intrinsic defects in the GaN lattice.

Endoscopic subureteral glutaraldehyde cross-linked collagen injection for the treatment of secondary vesicoureteral reflux: comparison with primary vesicoureteral reflux in adults.

PURPOSE: We assessed the effectiveness of endoscopic subureteral glutaraldehyde cross-linked collagen injection for treating vesicoureteral reflux in patients with vesicoureteral disorders. MATERIALS AND METHODS: All 51 ureters studied had grade II or greater vesicoureteral reflux. We treated 18 patients (24 refluxing ureters) with secondary and 17 adults (27 refluxing ureters) with primary vesicoureteral reflux. The primary group served as controls to establish normal urination. A total of 14 patients with secondary vesicoureteral reflux had a low compliant autonomous bladder, including 11 with myelodysplasia and 3 after pelvic surgery and radiotherapy. One patient had an unstable bladder due to cerebral palsy and 3 had anatomical abnormalities of the urinary tract. We evaluated the estimated reflux-free rate in the secondary and adult primary vesicoureteral reflux groups. RESULTS: Repeat injection was required in 24 ureters because of recurrent reflux. Average injected volume in the secondary and primary groups was 2.72 and 2.88 ml. per refluxing unit, respectively. The estimated reflux-free rate after the initial injection decreased gradually to about 35% in each group, while 12 and 24 months after the last injection it remained constant at 70% in the secondary group but decreased from 84.7% to 62.1% in the primary group. The percent of late recurrence was higher in the primary group. CONCLUSIONS: Long-term efficacy of the endoscopic correction of vesicoureteral reflux in the secondary group was similar to that in the primary group. Thus, endoscopic subureteral glutaraldehyde cross-linked collagen injection is useful for treating complicated secondary vesicoureteral reflux as a minimally invasive procedure. It is considered optional treatment of primary vesicoureteral reflux to avoid long-term prophylactic treatment.