Kinetics of water flow through a polymer gel

The water flow through the poly(acrylamide) gel under a constant water pressure is measured by newly designed apparatus. The Young modulus and Poisson's ratio of the rod shape gels are measured by the uni-axial elongation experiments, which determine the longitudinal modulus independently from the water flow experiments. The time evolution of the water flow in the dilute gel is calculated based on the collective diffusion model of the polymer network coupled with the friction between the polymer network and the water. The calculated results are compared with the time evolution of the flow experiments, and the values of the longitudinal modulus and the friction coefficient are estimated. The estimated values are consistent with the results of our mechanical-response experiments and the light scattering experiments reported previously. We find that the time evolution of the water flow is well described by a single characteristic relaxation time predicted by our model for dilute gels.

Cataract in atomic bomb survivors

PURPOSE

Ophthalmologic examinations were conducted on atomic bomb (A-bomb) survivors 55 years after exposure.

MATERIALS AND METHODS

A-bomb survivors who had been exposed before 13 years of age at the time of the bombings in 1945 or who had been examined in a previous study between 1978 and 1980. The examinations, conducted between June 2000 and September 2002, included slit-lamp examination, digital photography and a cataract grading system for three parts of the lens (nucleus, cortex and posterior subcapsule) as an outcome variable. Proportional odds logistic regression analysis was conducted using the lowest grading class as a reference and included explanatory variables such as age, sex, city, dose and various cataract-related risk factors. When the grades in an individual differed, the worst grade was used.

RESULTS

Results indicate that odds ratios (ORs) at 1 Sv were 1.07 (95% confidence intervals [CI] 0.90, 1.27) in nuclear colour, 1.12 (95% CI 0.94, 1.30) in nuclear cataract, 1.29 (95% CI 1.12, 1.49) in cortical cataract and 1.41 (95% CI 1.21, 1.64) in posterior subcapsular cataract. The same was true after excluding 13 people whose posterior subcapsular cataracts had been previously detected.

CONCLUSION

Significant radiation effects were observed in two types of cataracts in A-bomb survivors.

A multicenter randomized phase II study of full-dose gemcitabine and concurrent radiotherapy comparing gemcitabine alone for the unresectable locally advanced pancreatic adenocarcinoma

e15512

Background: Some of locally advanced pancreatic cancers (LAPC) are considered to include a potential micro metastasis. We think that full-dose of gemcitabine (GEM) improve the outcome of LAPC. We report the efficacy of full-dose GEM and concurrent radiotherapy, comparing GEM alone for unresectable LAPC. Methods: Patients with histologically or cytologically proven pancreatic adenocarcinoma were eligible for this study. We decide that LAPA which involved a major artery with CT imaging was unresectable. Patients were randomized into a concurrent chemoradiotherapy (CRT) group and a chemotherapy alone (CTX) group. GEM was given intravenously at a dose of 1,000 mg/msq over 30 min on days 1, 8 and 15 of each 28-day cycle and repeated until disease progression in both groups. Patients randomized into CRT group received a limited field irradiation with a total dose of 50 Gy in 25 sessions during first two cycles. The two groups were compared for mean survival, progression free survival and safety. Results: From September 2002 to April 2005, 80 patients were randomized at two institutions into the two arms of the trial (40 patients to CRT group and 40 patients to CTX group). The CRT group had better results than the CTX group as measured by mean survival time (391 vs 372 days, P< 0.02) and progression free survival (237 vs 128 days, P< 0.01). There were no differences in the safety between both groups. Conclusions: The concurrent chemoradiotherapy with full-dose GEM is effective and feasible in patients of LAPC compared with full-dose GEM alone.

No significant financial relationships to disclose.

Trilateral optical powermeter comparison between NIST, NMIJ/AIST, and METAS

We describe the results of a comparison of reference standards between three National Metrology Institutes: the National Institute of Standards and Technology (NIST, USA), the National Metrology Institute of Japan/National Institute of Advanced Industrial Science and Technology (NMIJ/AIST, Japan), and the Federal Office of Metrology (METAS, Switzerland). Open-beam- (free field) and optical-fiber-based measurements at wavelengths of 1302 and 1546 nm are reported. Three laboratories' reference standards are compared by means of two temperature-controlled, optical trap detectors. Measurement results show the largest differences of less than 4.2 parts in 10(3), which is within the expanded (k=2) uncertainty for the laboratories' reference standards.

Transforming growth factor-beta1 mediates the effects of low-intensity pulsed ultrasound in chondrocytes

Low-intensity pulsed ultrasound (LIPUS) has been shown to accelerate fracture healing, but the precise mechanism is still unknown. We used aggregate chondrocyte culture system to analyze LIPUS-induced effects on chondrocytes. First, Northern analyses revealed that LIPUS maintained higher expression levels of type II collagen and aggrecan mRNA and delayed the appearance of type X collagen mRNA expression. We also showed that DNA content was increased and that alkaline phosphatase activity was maintained low by daily treatment. Moreover, LIPUS significantly promoted transforming growth factor (TGF)-beta1 mRNA expression and the protein production at 2 h and 12 h after the treatment, respectively. Furthermore, recombinant TGF-beta1 protein mimicked the LIPUS effect and anti-TGF-beta1 neutralizing antibody reversed all these changes induced by the LIPUS treatment. These results indicate that LIPUS promotes the proliferation and retains the differentiation state of chondrocytes in the aggregate culture and that TGF-beta1 plays an important role in mediating the LIPUS effects in chondrocytes.

Inactivation of Cryptosporidium parvum by ultrasonic irradiation

The inactivation of Cryptosporidium parvum was investigated by the use of three different sonicators utilizing the squeeze-film effect, which may occur when ultrasound is irradiated into an extremely thin space and generate intensified pressure in the sample suspension. To expand from the small-scale horn-type sonicator to large-scale cylindrical or cleaning bath sonicators, the inactivation effectwas improved. In the case of the cylindrical sonicator (26.6 kHz, 30 W), 97% of the initial concentration of 2260 oocysts mL(-1) was inactivated at33 mL min(-1) (residence time of approximately 5.2 min). Hundreds of cubic meters of water can be treated per day at several kW using this sonicator. In addition, the simultaneous use of sonication and chlorination showed a beneficial effect on inactivation for C. parvum based on the evaluation of infectivity testing and morphological observation.

[Aortic valve replacement presence of anti-Jr(a) antibody]

A 65-year-old female with a heart murmur developed progressive symptom of chest oppression. She was diagnosed severe aortic valve stenosis with echocardiogram. Antibody screening revealed anti-Jr(a) antibody. Preoperatively, erythropoietin was administered. Over 14 days, a total 1,000 ml of her blood was drawn and stored for autologous transfusion. The aortic valve was replaced with ATS mechanical valve [18 mm advanced performance (AP)]. Following surgery, her stored blood was administered to him. But her HCT was 17% on the 1st postoperative day. Frozen thawed red cells were transferred 7th postoperative day.

Treatment of gastric hemorrhage by pulverized omeprazole and antacid – concomitant administration via a nasogastric tube

Gastroesophageal reflux (GER) is a common episode in pediatric patients with severe motor and intellectual disabilities (SMID) and occasionally leads to a severe clinical state accompanied with nausea, hematemesis, melena, wheezing, pneumonia, anemia and/or failure to thrive. We report here a case of a 14-year-old male with Lennox syndrome who had been treated with a histamine H2 blocker intravenously or via a nasogastric tube for repeated gastric hemorrhage due to severe GER. Since his gastric hemorrhage became resistant to the H2 blocker, we decided to replace it with a proton pump inhibitor (PPI). Although lansoprazole can be decapsulated for administration via a nasogastric tube, it tends to block fine tubes. The acid-sensitive drug omeprazole, another oral PPI, is commercially available as enteric-coated tablets. Therefore, we pulverized the tablets and administered omeprazole, mixed with a small amount of antacid, via a nasogastric tube. The patient's gastric hemorrhage was dramatically improved. Thus, administration of pulverized omeprazole concomitantly with antacid via a fine nasogastric tube may provide a novel approach for the treatment of chronic GER in pediatric patients with SMID.

[Surgical treatment for left ventricular false aneurysm caused by infective endocarditis; report of a case]

A 24-year-old man who had left ventricular (LV) false aneurysm, which is caused by mitral valve infective endocarditis, underwent aneurysmectomy, direct closure of aneurysmal mouth and concomitant mitral valve replacement. Post-operative course was uneventful. It has been reported that the etiology of this false aneurysm was due to the vegetations' friction, which could have caused an initial endocardial ulceration that progressively expanded into the myocardium. The false aneurysmal wall should be completely removed in order to eliminate the possibility of recurrence of the infective endocarditis. We believe that the surgical treatment should be carried out as soon as possible after completion of diagnosis because the aneurysmal wall is usually quite thin and could rupture easily.

Simultaneous stimulation of EP2 and EP4 is essential to the effect of prostaglandin E2 in chondrocyte differentiation

OBJECTIVE

Prostaglandin E(2)(PGE(2)) has been reported to stimulate chondrocyte differentiation. However, the precise actions and signal transduction pathways of PGE(2)in cartilage are largely unknown. Our purpose is to identify which of the four PGE(2)receptor subtype(s), EP1-4, mediates the action of PGE(2)on chondrocyte differentiation.

DESIGN

We used primary chondrocytes derived from the resting zone of rat rib cartilage. The effects on chondrocyte differentiation were assessed by measuring the Alcian blue-stainable proteoglycan content and the expression levels of type II collagen mRNA by Northern blot analysis. The expression of the four PGE(2)receptor subtypes in rat primary chondrocytes was examined by reverse transcription-polymerase chain reaction.

RESULTS

PGE(2)stimulated the accumulation of proteoglycan and up-regulated the expression of type II collagen mRNA in primary chondrocytes. Dibutyryl cAMP, a cell-permeable analog of cAMP, an important intracellular mediator of PGE(2)signaling, also enhanced the expression of type II collagen mRNA and proteoglycan accumulation in chondrocytes. No EP agonist alone induced the expression of type II collagen mRNA. However, simultaneous administration of EP2 and EP4 agonists at high concentrations cooperatively induced the expression of type II collagen mRNA, mimicking the PGE(2)effect. The simultaneous stimulation of EP2 and EP4 also cooperatively enhanced proteoglycan accumulation and intracellular cAMP production. Moreover, an EP4 antagonist partially blocked the stimulatory actions of PGE(2)on the expression of type II collagen mRNA.

CONCLUSION

These results suggest that simultaneous stimulation of EP2 and EP4 is necessary and sufficient to elicit the effect of PGE(2)on rat primary chondrocyte differentiation.

[Prosthetic valve endocarditis after aortic valve replacement with freestyle stentless xenograft]

A 52-year-old man underwent aortic valve replacement with freestyle stentless xenograft, using subcoronary technique for active infective endocarditis in June, 2001. Eighteen month later he had late prosthetic valve endocarditis associated with aortic annular abscess due to Staphylococcus epidermidis infection. The abscess was debrided and gelatin-resorcin-formalin glue (GRF glue) was injected into the abscess cavity. Abscess cavity was closed with continuous running suture of 3-0 polypropylene stitches. Finally the aortic valve was replaced with ATS mechanical valve (20 mmAP). After administration of vancomycin and gentamicin for 4 weeks, he discharged on 57th postoperative day in good condition. We strongly suggest that GRF glue is essential to close the aortic annular abscess of combined with aortic regurgitation due to active infective endocarditis.

[Thymic carcinoma (mixed small cell undifferentiated squamous cell carcinoma); report of a case]

A 52-year-old man was admitted to our hospital on October, 1997 with complains of left anterior chest pain. A chest X-ray and computed tomography on admission showed evidence of a mass in the left anterior mediastinum. The patient was treated with combination chemotherapy [cisplatin (CDDP), etoposide (VP-16)] and radiation therapy (2 gray x 25 days), preoperatively. Median sternotomy revealed a tumor invading into the left anterior chest wall, the pericardium, and partial pleura. The tumor was extirpated with combined resection of invaded organs. Microscopically and immunohistochemically, the tumor was diagnosed mixed small cell and undifferentiated squamous cell carcinoma documented by Snover et al. The patient was discharge on March 1998, but 2 years later after operation, he was dead by recurrent. We reported a rare case of thymic carcinoma.

Combined aortic valve replacement and coronary artery bypass grafting with in situ arterial grafts for porcelain aorta

Patients with porcelain aorta carry a high risk of cerebral as well as systemic embolism during cardiac surgery. Here we describe a case of severe aortic stenosis and coronary artery disease combined with the circumferentially calcified aorta. The patient was a 77-year-old man who successfully received four coronary artery bypass grafts with in situ arterial grafts without clamping the aorta and aortic valve replacement. Aortic valve replacement and two distal coronary artery anastomoses to the left circumflex artery and obtuse marginal branch were performed under cardiac arrest during hypothermic perfusion with endoaortic balloon occlusion, followed by partial endarterectomy and closure of the aorta buttressed with bovine pericardium under deep hypothermic circulatory arrest. While rewarming, the other two distal coronary anastomoses to the left anterior descending artery and diagonal branch were done on the beating heart in order to minimize cardiac arrest time. On-pump beating heart coronary artery bypass grafting (CABG) can be useful especially for combined complex cardiac surgery.

Cost performance and efficacy of off-pump coronary artery bypass grafting

Off-pump coronary artery bypass grafting (Off-Pump CABG) may provide an alternative form of surgical revascularization by avoiding the unwanted complications of cardiopulmonary bypass, particularly in high-risk patients. To clarify the efficacy and cost performance of Off-Pump CABG, we studied the postoperative course of Off-Pump CABG and compared it to On-pump coronary artery bypass grafting (On-Pump CABG). From Aug. 1998 to Feb. 2002, twenty-eight patients who had preoperative complications such as cerebral vascular disease (11), chronic renal failure (4), atheromatous aorta (4), one lung (1), severely impaired left ventricular function (6), re-do CABG (1), and cancer (1) underwent Off-Pump CABG. Another thirty-six patients who underwent On-Pump CABG served as a control. The Off-Pump CABG patients were almost the same age as the On-Pump CABG patients (68 +/- 8 vs 64 +/- 8 years, ns). The Number of grafts was similar in both groups (2.6 +/- 1.0 vs 2.9 +/- 1.0, ns). Peak CK, peak CKMB, peak LDH, and peak GOT release were significantly lower in the Off-Pump CABG group compared with the On-Pump CABG group. Graft patency rates were similar in both groups (98% in Off-Pump CABG vs 98% in On-Pump CABG). The total cost for surgery and patient care was significantly lower (p < 0.0001) in the Off-Pump CABG group (dollar 21000 +/- 7000) compared with the On-Pump CABG group (dollar 33000 +/- 4200). Off-Pump CABG is less invasive to the myocardium, is less expensive, and has a similar efficacy in comparison with On-Pump CABG.

Lectin-like oxidized low-density lipoprotein receptor 1 mediates leukocyte infiltration and articular cartilage destruction in rat zymosan-induced arthritis

OBJECTIVE

The relationship between rheumatoid arthritis and atherosclerosis has been recognized for >20 years. This study aimed to elucidate the roles of oxidized low-density lipoprotein (ox-LDL; one of the main pathogenic factors of atherosclerosis) and its endothelial receptor, lectin-like ox-LDL receptor 1 (LOX-1), in arthritic joints using a rat zymosan-induced arthritis (ZIA) model.

METHODS

LOX-1 expression and ox-LDL accumulation in arthritic joints were detected by immunohistochemistry using specific mouse anti-LOX-1 and anti-ox-LDL monoclonal antibodies, respectively. To elucidate the effects of the expressed LOX-1 on arthritis, ZIA rats were treated with anti-LOX-1 antibody or normal mouse IgG. The severity of arthritis was analyzed by joint swelling. Cell infiltration, synovial hyperplasia, and proteoglycan losses were also determined by histologic scoring. Proinflammatory cytokine and nitrite levels in serum and joint fluid were also measured.

RESULTS

Immunohistochemical study of ZIA demonstrated LOX-1 expression on synovial endothelium and postcapillary venules at 6 hours after the induction of inflammation, with maximum expression detected at 24 hours. LOX-1 was also expressed weakly on both joint cartilage and synovium. Ox-LDL, a ligand of LOX-1, was also detected in articular chondrocytes. Administration of anti-LOX-1 antibody, which blocks LOX-1 activity, suppressed joint swelling (by 33.5%), leukocyte infiltration, and joint nitrite accumulation at 24 hours, as well as cartilage destruction at 7 days, compared with control rats.

CONCLUSION

LOX-1 induction in arthritic joints might play a role in promoting joint inflammation and cartilage destruction by mediating leukocyte infiltration into the arthritic joints of ZIA rats.

Acutely dissected aorta: a reliable and leak-proof technique

When repairing an acutely dissected aorta, a primary concern is bleeding from the anastomotic site. To prevent a hemorrhagic complication, a unique variation of wall reinforcement with xenopericardium together with GRF glue was introduced to provide a leakproof seal for ascending and descending aortic grafts.

Postural response of low-frequency component of heart rate variability is an increased risk for mortality in patients with coronary artery disease

STUDY OBJECTIVES

We examined whether autonomic functions assessed by heart rate variability (HRV) during standardized head-up tilt testing (HUTT) predict risk for death in stable patients with coronary artery disease (CAD).

DESIGN AND SETTING

Retrospective cohort study in medium-sized university general hospital.

MEASUREMENTS AND RESULTS

In a cohort of 250 patients with CAD who were undergoing elective coronary angiography, we analyzed HRV during standardized HUTT under paced breathing with discontinuation of treatment with all medications. During a subsequent mean follow-up period of 99 months, there were 13 cardiac deaths and 12 noncardiac deaths. Cox regression analysis adjusted for cardiovascular risks revealed that increased postural change (supine to upright) in the power of low-frequency component (LF) power predicted an increased risk for cardiac death (relative risk [per 1-ln ms(2) increment], 4.36; 95% confidence interval, 1.64 to 11.6), while neither the high-frequency component nor its response to HUTT predicted any form of death. When the patients were trichotomized by the level of postural LF change (large drop, < or = - 0.6 ln[ms(2)]; small drop and rise, > 0 ln[ms(2)]), the three groups did not differ in terms of clinical features or CAD severity at baseline or coronary interventions during the follow-up period; however, the 8-year cardiac mortality rates were 0%, 6%, and 12%, respectively (p = 0.008 [log rank test]). Additionally, the difference was enhanced when analyzed excluding 64 patients who had been treated with a beta-blocker during the follow-up period (0%, 7%, and 15%, respectively; p = 0.006 [log rank test]).

CONCLUSIONS

The postural response of HRV predicts the risk for death in patients with CAD. Postural LF increase (LF rise), in particular, is an independent risk factor for cardiac death.

The role of E-cadherin in the differentiation of gallbladder cancer cells

Cell adhesion molecules are essential for development and maintenance of epithelial architecture. To clarify the role of these molecules in the morphology of gallbladder cancers, four human gallbladder cancer cell lines (GB-d1, KMG-C, GBK-1, and G-415) were examined in vitro. They showed noticeably different morphologies in our standard gel cultures (SC). GB-dl and KMG-C formed cystic and spheroid structures, respectively, which seemed to represent well-differentiated and moderately differentiated cancers, respectively. GBK-1 and G-415 showed branching and "pseudoglandular" structures, respectively, both of which seemed to indicate original dedifferentiated cancers. In floating gel culture (FC), only GB-d1 showed a highly increased tendency toward cyst formation. Expression of E-cadherin and alpha-catenin in the gallbladder cancer cell lines was investigated by Western-blotting analysis. Expression was detected in GB-d1 and KMG-C, but not in GBK-1 and G-415 cells. Furthermore, E-cadherin expression in GB-dl was 1.82 times greater in FC than in SC, while E-cadherin expression levels of KMG-C did not change. Neither GB-d1 nor KMG-C showed any difference in a-catenin expression between SC and FC. Immunostaining of GB-d1 revealed that these proteins were localized to the cell membrane. In contrast, heterogeneous localization of these proteins was detected in the spheroid structures of KMG-C, in both SC and FC. Electronmicroscopic examination revealed that reestablishment of the junctional complex occurred only in GB-d1 cells cultured in FC. The formation of cystic structures in GB-d1 was completely inhibited by an antibody against human E-cadherin. Both expression of E-cadherin and its membranous localization are required for well-differentiated-type morphogenesis in gallbladder cancer cells.

Predicting cerebral blood flow response to orthostatic stress from resting dynamics: effects of healthy aging

The transfer function relating arterial pressure (AP) to cerebral blood flow velocity (CBFV) during resting conditions has been used to predict the CBFV response to hypotension. We hypothesized that this approach could predict the CBFV response to posture change in elderly individuals if impaired autoregulation allowed changes in AP to be passively transferred to CBFV. AP (Finapres) and CBFV (middle cerebral artery transcranial Doppler) were measured in 10 healthy young (age 24 +/- 1 yr) and 10 healthy elderly (age 72 +/- 3 yr) subjects during 5 min of quiet sitting and 1 min of active standing while breathing was paced at 0.25 Hz. Transfer functions between AP and CBFV changes during sitting were estimated from each full waveform in both low-frequency (LF; 0.05-0.2 Hz) and heartbeat-frequency (HBF; 0.7-1.4 Hz) ranges. The impulse-response function was used to compute changes in CBFV during posture change. The LF transfer function did not predict orthostatic changes in CBFV in either group, suggesting normal cerebral autoregulation. In the HBF range, the prediction was high in elderly (R = 0.65 +/- 0.23) but not young subjects (R = 0.19 +/- 0.35; P < 0.003, young vs. elderly). Thus rapidly acting regulatory mechanisms that reduce the transmission of beat-to-beat changes in AP to CBFV may be engaged during posture change in young but not elderly subjects.

Prevention and detection of spinal cord injury during thoracic and thoracoabdominal aortic repairs

BACKGROUND

Spinal cord injury is a most dreaded and unpredictable complication. In this study, based on our experimental results in dogs and early clinical results, we reviewed the incidence of paraplegia and the detection of spinal cord injury.

METHODS

Eighty-two patients who underwent elective surgical repair of the descending thoracic and thoracoabdominal aorta over 17 years were subjects for this study. Sixty-two patients were male and 20 were female. Their mean age was 61.6 years (range, 17 to 81 years). Monitoring somatosensory evoked potentials (SEP) and measurement of mean distal aortic pressure and cerebrospinal fluid pressure were performed perioperatively.

RESULTS

Sixty patients had no ischemic change in SEP. In 17 patients with significant ischemic changes of SEP, SEP recovered by increasing spinal cord perfusion pressure to more than 40 mm Hg. Two patients with complete loss of SEP experienced paraplegia. One patient had delayed paraplegia.

CONCLUSIONS

These results strongly suggest that SEP, mean distal aortic pressure, cerebrospinal fluid pressure should be monitored during aortic cross-clamping. Maintaining spinal cord perfusion pressure at more than 40 mm Hg by increasing mean distal aortic pressure or withdrawal of cerebrospinal fluid is valuable for preventing paraplegia.

A case of bladder pheochromocytoma

The clinical picture of bladder pheochromocytoma is usually typical; however, the diagnosis is occasionally delayed because of the rarity of this neoplasm. We report a case of unsuspected bladder pheochromocytoma in which the patient had a hypertensive episode during transurethral resection. A 67-year-old male presented with the chief complaint of painless macrohematuria. Cystoscopy revealed a submucosal tumor on the right lateral wall of the bladder. The tumor was operated on transurethrally, followed by partial cystectomy. The pathological diagnosis was pheochromocytoma, primarily occurring in the bladder. Treatment of this lesion requires a high degree of clinical suspicion based on the patient's symptom complex in order to enable adequate preparation prior to surgical manipulation.