Therapeutic challenges in transcatheter arterial embolization for an enlarging subcutaneous hematoma in a patient with neurofibromatosis type 1: A case report

A 60-year-old woman with a history of neurofibromatosis type 1, who was admitted with pulmonary hypertension, developed buttock pain and anemia, and contrast-enhanced computed tomography showed a large subcutaneous hematoma with minimal active extravasation. Angiography of the bilateral internal iliac arteries revealed diffuse, irregular blood vessels without extravasation. As the exact bleeding site could not be identified, the patient was managed conservatively. However, the patient's symptoms and anemia worsened the following day. Repeat angiography revealed two pseudoaneurysms in the right inferior gluteal artery, which were embolized using n-butyl-2-cyanoacrylate. Nonetheless, the patient's anemia further worsened the following day. Repeat contrast-enhanced CT revealed another site of extravasation in the enlarging hematoma, but no extravasation was observed on the subsequent angiography. Owing to the worsening anemia and enlarging hematoma, proximal embolization of the irregular bilateral inferior gluteal arteries was performed using gelatin sponge particles. The patient's anemia and symptoms improved. Vasculopathy associated with neurofibromatosis type 1 is rare, with an incidence of approximately 3%. In patients with neurofibromatosis type 1, the blood vessels become fragile because of tunica media thinning and elastic-lamina rupture. Histopathologically, neurofibromatosis type 1-associated vasculopathy is characterized by a mixture of normal and abnormal vessels. Abnormally fragile blood vessels may repeatedly rupture followed by physiological hemostasis, which may explain the diagnostic and therapeutic challenges during angiography in this case. In patients with neurofibromatosis type 1 with acute bleeding, irregular vessels without active extravasation on angiography may be indicated for embolization.

Single-photon emission computed tomography (SPECT) predicted neurological prognosis in heat stroke: A case report

Heat stroke may cause multi-organ dysfunction and death. Some patients with neurological abnormalities in the acute phase have neurological sequelae, particularly cerebellar ataxia, in the recovery phase. However, there is no method to predict the neurological prognosis, and the usefulness of imaging has not yet been established. We report the case of an 86-year-old woman with dementia brought to our emergency department in a coma and hyperthermia. The patient was diagnosed with heat stroke and promptly treated in the ICU but remained unconscious. The patient gained consciousness on day 19, but difficulty with stillness associated with cerebellar ataxia in her right upper extremity became apparent. On day 1, head magnetic resonance imaging (MRI) showed no obvious abnormality. However, on day 6, high-signal areas, suggestive of edema, were seen in the bilateral cerebellar hemispheres. Single-photon emission computed tomography (SPECT) on day 9 revealed significant hypoperfusion in the right cerebellum. These changes improved at the time of hospital discharge. This was a case of persistent cerebellar ataxia due to heat stroke, in which imaging findings improved over time. In most cases, MRI findings do not match clinical symptoms. However, the low cerebral blood flow in the early SPECT images was consistent with the clinical symptoms. MRI may not be a prognostic indicator; however, SPECT images may be useful for predicting sequelae.

"Welcome to OBGYN World!" A novel recruitment event for medical students organized by the Japan Society of Obstetrics and Gynecology

"Welcome to OBGYN World!" A novel recruitment event for medical students organized by the Japan Society of Obstetrics and Gynecology. Since 2012, the number of doctors in Japan who specialize in obstetrics and gynecology has shown a decreasing trend. To increase the number of doctors majoring in obstetrics and gynecology, the Japanese Trainees in Obstetrics and Gynecology subcommittee developed a new recruitment event called Welcome to OBGYN World! (WOW!); the aim of this event was to focus on lower grades of medical students. The present report describes the content of WOW! and the results of a post-event questionnaire administered to participating students and tutors. WOW! was held online in order to avoid the risk of Coronavirus Disease 2019 infection for participants. Sixty of the 82 medical schools nationwide (73.2%) participated in this event. Overall, there were 285 participating students, ranging from first to fourth grade in medical school, and 106 tutors were involved to teach material at the event. In the post-event questionnaire survey, 97.6% (248/254) and 100% of the participants stated they now had a high degree of interest in obstetrics and gynecology and found the specialty attractive, respectively. Furthermore, 93.6% (90/94) of the tutors stated that WOW! had helped recruitment activities in their universities. Based on this outcome, members of the Japanese Trainees of Obstetrics and Gynecology subcommittee will now try to increase the number of doctors specializing in obstetrics and gynecology by holding WOW! annually.

Membranous nephropathy without vacuolated podocytes in Fabry disease treated with agalsidase-β and carbamazepine: A case report

RATIONALE

Vacuolated podocytes are the most common form of renal damage in Fabry disease, but other types of renal damage have been reported, such as membranous nephropathy (MN) or IgM nephropathy. Enzyme replacement therapy (ERT) is effective at preventing renal damage, but the nephropathies require appropriate treatment to prevent renal damage.

PATIENT CONCERNS

A 22-year-old male with Fabry disease presented with proteinuria during ERT with agalsidase-β and carbamazepine. He had received the treatment for 10 years and maintained normal plasma globotryaosylceramide levels.

DIAGNOSIS

Renal biopsy revealed MN without vacuolated podocytes. Immunofluorescent staining of the IgG subclass revealed granular patterns of IgG1, G2, G4, and C3 deposition in the glomerular basement membrane.

INTERVENTIONS

The carbamazepine dose was reduced from 600 mg/day to 200 mg/day (serum concentration 10.0-11.0-4.0-5.0 μg/mL).

OUTCOMES

After reducing the carbamazepine dose, proteinuria was negative, and the patient has had a normal urinalysis for 17 months. Plasma globotryaosylceramide levels have also remained normal.

LESSONS

This report is a reminder of the co-existence of MN without vacuolated podocytes in Fabry disease during ERT with agalsidase-β and carbamazepine.Physicians should be aware of this form of renal damage in Fabry disease, even during treatment.

Glucocorticoid effects on bone strength in children with renal diseases

AIM

Glucocorticoids (GC) are essential medicines for idiopathic steroid-sensitive nephrotic syndrome (ISSNS) and IgA nephropathy (IgAN), with good clinical results. However, they cause bone fragility. The aim of this study was to elucidate GC effects on bone strength assessed as bone mineral density (BMD) and bone quality, using bone turnover markers (BTM), in children with ISSNS or IgAN.

METHODS

Eleven children with ISSNS and 13 with IgAN were included. All the patients received GC treatment according to each protocol. The BMD and BTM-serum alkaline phosphatase (S-ALP), tartrate-resistant acid phosphatase 5b (S-TRACP-5b), and undercarboxylated osteocalcin (S-ucOC)-were measured from the initiation of steroid treatment (STx) to the end of STx in both groups.

RESULTS

In ISSNS, S-ALP and S-ucOC levels were decreased significantly at 1 month. BMD and S-TRACP-5b levels showed no significant change through this observation period. In IgAN, BMD and S-ALP levels were decreased significantly at 1 and 3 months, respectively, and recovered to baseline at 10 months after the initiation of GC dosage reduction. S-TRACP-5b levels were decreased significantly at 3 months and remained lower than at baseline through the observation period. In both groups, S-ucOC levels did not directly reflect bone strength.

CONCLUSION

This study clarified the following three points regarding GC effects on bone strength in children with ISSNS or IgAN: first, S-ALP is a more sensitive bone quality marker than S-TRACP-5b; second, BMD loss was observed only when both S-ALP and S-TRACP-5b levels decreased, and third, S-ucOC levels do not directly reflect bone strength.

Prevention of recurrent febrile urinary tract infection in infants: Ultrasonography-oriented approach is more practical than a top-down approach

BACKGROUND

We previously reported that the top-down approach (TDA) for infants with febrile urinary tract infections (fUTI) could prevent recurrent fUTI (r-fUTI) but produced a high number of false-positives on acute-phase ^99m Tc dimercaptosuccinic acid (DMSA) renal scintigraphy. Therefore we compared the ultrasonography-oriented approach (USOA) with TDA from the viewpoint of prevention of r-fUTI.

METHODS

The TDA was applied between July 2010 and February 2014 and the USOA was applied between March 2014 and April 2017 in infants with first fUTI. In the USOA group, voiding cystourethrography (VCUG) was performed in the case of abnormality on acute-phase renal bladder ultrasonography (RBUS) or on chronic- phase DMSA, which were performed in all cases. The frequency of r-fUTI was compared between the TDA group and USOA group retrospectively.

RESULTS

Seventy-four infants (52 male) and 79 infants (60 male) received TDA or USOA, respectively. No significant differences were found between the TDA and USOA groups in male : female ratio, age in months at initial onset of fUTI, observation period, or number of cases of r-fUTI (TDA group, n = 4; USOA group, n = 5). Seventy-four DMSA scintigraphy and 25 VCUG were carried out in the USOA group, and 111 DMSA scintigraphy and 34 VCUG in the TDA group.

CONCLUSIONS

Both USOA and TDA were valid for prevention of r-fUTI, but USOA was superior to TDA with regard to the reduced number of patients undergoing VCUG and DMSA.

Frequency and features of myasthenia gravis developing after thymectomy

BACKGROUND AND PURPOSE

Thymectomy is an effective treatment for myasthenia gravis (MG) with anti-acetylcholine receptor (AChR) antibodies. We rarely encounter patients who develop MG after surgery for thymic tumors. This study aimed to investigate the characteristics and frequency of post-thymectomy onset (PostTx) MG.

METHODS

We reviewed the clinical information of thymoma-associated MG in 158 patients. Of these, 18 (11%) patients with PostTx MG were identified.

RESULTS

The presence of anti-AChR antibodies (82%) and electrophysiological abnormalities (50%) was confirmed before thymectomy in patients with PostTx MG. The clinical characteristics of PostTx MG were similar to those of pre-thymectomy onset (PreTx) MG. In PostTx MG, the duration between thymectomy and MG onset were distributed as < 6 months (early-onset PostTx MG) and ≥ 6 months (late-onset PostTx MG). Notably, some patients with late-onset PostTx MG were associated with thymoma relapse.

CONCLUSION

Our results suggest that approximately 11% of patients with thymoma-associated MG were PostTx MG and pre-surgical assessment of anti-AChR antibody titer or electrophysiological testing may predict PostTx MG development. However, no difference in clinical manifestation and prognosis was observed between PreTx MG and PostTx MG.

Safety of tapering tacrolimus dose in patients with well-controlled anti-acetylcholine receptor antibody-positive myasthenia gravis

BACKGROUND AND PURPOSE

Tapering immunosuppressants is desirable in patients with well-controlled myasthenia gravis (MG). However, the association between tapering of calcineurin inhibitor dosage and reduction-associated exacerbation is not known. The aim of this study was to clarify the frequency of reduction-associated exacerbation when tacrolimus is tapered in stable patients with anti-acetylcholine receptor antibody-positive MG, and to determine the factors that predict exacerbations.

METHODS

We retrospectively analyzed 115 patients in whom tacrolimus dosage was tapered. The reduction-associated exacerbation was defined as the appearance or worsening of one or more MG symptoms <3 months after the reduction.

RESULTS

Tacrolimus dosage was successfully tapered in 110 patients (96%) without any exacerbation. Five patients (4%) experienced an exacerbation, but symptoms were reversed in all patients when the tacrolimus dose was increased to the previous maintenance level. No patient developed an MG crisis. The age at onset was significantly earlier (30 vs. 56 years, P = 0.025) and the reduction in dosage was significantly larger (2.0 vs. 1.0 mg/day, P = 0.002) in patients with reduction-associated exacerbation than in those without exacerbation. The cut-off values determined in a receiver-operating characteristic curve analysis were 52 years (sensitivity, 57%; specificity, 100%) for the age at onset and 1.5 mg (sensitivity, 80%; specificity, 100%) for the dose reduction.

CONCLUSION

Tapering of tacrolimus was possible in most patients with well-controlled anti-acetylcholine receptor antibody-positive MG. Early age at onset and a large reduction from maintenance dosage were associated with exacerbation. Reductions ≤1.5 mg/day from the maintenance dosage should be considered for patients with late-onset disease.

First report of hepatobiliary Mycobacterium avium infection developing obstructive jaundice in a patient with neutralizing anti-interferon-gamma autoantibodies

This study describes a patient who experienced hepatobiliary Mycobacterium avium infection associated with neutralizing anti–interferon gamma (IFN-γ) autoantibodies during treatment for disseminated M. avium disease. Hepatobiliary M. avium infection should be considered in jaundiced patients with neutralizing anti–IFN-γ autoantibodies, including those receiving antimycobacterial therapy for disseminated M. avium disease.

A decreased soluble Klotho level with normal eGFR, FGF23, serum phosphate, and FEP in an ADPKD patient with enlarged kidneys due to multiple cysts

Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary renal disorder. ADPKD is characterized clinically by the presence of multiple bilateral renal cysts that lead to chronic renal failure. The cysts evolve from renal tubular epithelial cells that express the Klotho gene. Notably, Klotho acts as a co-receptor for fibroblast growth factor 23 (FGF23); in this context, it induces phosphaturia and maintains serum phosphate at a normal level. Many reports have shown that decreases in the soluble Klotho level and increases in the FGF23 level are associated with glomerular filtration rate (GFR) decline, but a recent study observed these changes in patient with normal eGFR. It remains unclear whether the decrease in the Klotho level precedes the increase in FGF23. Here, we present an ADPKD patient with enlarged kidneys due to multiple cysts who had a decreased soluble Klotho level but a normal eGFR and a normal FGF23 level. The patient's serum phosphate level was normal, as was the fractional excretion of phosphate (FEP). This appears to be the first reported case to show a decreased soluble Klotho level plus normal eGFR, FGF23, and FEP. These results suggest that Klotho decreases before FGF23 increases and further suggest that Klotho is not required to maintain normal serum phosphate levels in ADPKD if the FEP and serum phosphate levels are normal.

Predominant but silent C1q deposits in mesangium on transplanted kidneys - long-term observational study

Background

C1q nephropathy (C1qN) was first described as glomerular disease characterized by predominant meangial C1q deposits in patients with proteinuria and no evidence of systemic lupus erythematosus. Several studies, however, revealed the clinical heterogeneity of C1qN, showing some cases with normal urinalysis. To confirm the existence of cases with predominant mesangial C1q deposits and negative or mild proteinuria and/or hematuria, we investigated renal graft biopsy specimens showing negative to mild proteinuria (less than or equal to 1+ by dip stick test) and/or hematuria.

Methods

Eligible participants were kidney transplant cases who corresponded to the criteria for C1qN and were followed more than 10 years. Their medical records were reviewed to determine the age at detection of predominant mesangial C1q deposits, gender, original renal disease and reason for renal graft biopsy, blood pressure, degree of proteinuria and hematuria, and serum creatinine levels.

Results

From 414 cases in adults and children, five pediatric patients (the male to female ratio, 1:1.5) were eligible. At the time when predominant mesangial C1q deposits were detected, 2 cases presented with mild proteinuria without hematuria, but the other 3 cases showed normal urinalysis. Light microscopy revealed minor glomerular abnormality in all the cases. Immunofluorescent study showed predominant mesangial C1q deposits with IgG, IgM and C3 in all cases. All selected specimens presented electron dense-depos in the mesangium. Ten years later from the detection, 2 cases continued to be normal urinalysis and 3 cases had mild proteinuria without hematuria. During this follow-up period, no cases presented with persistent proteinuria and/or hematuria greater than or equal to 2+ by dip stick test. And no cases developed systemic lupus erythematosus. Follow-up renal graft biopsies were performed once in 2 cases 8 years later from the detection. They showed minor glomerular abnormalities. C1q deposit disappeared in one case. In another case, immunofluorescent study was not examined.

Conclusions

This long-term observational study on transplanted kidneys confirms the existence of cases with predominant but silent C1q deposits in the mesangium who have negative or mild proteinuria.

Electronic supplementary material

The online version of this article (10.1186/s12882-018-0874-9) contains supplementary material, which is available to authorized users.

Abstract P3-01-05: A feasibility study of sentinel lymph node detection and analysis of safety to omit axillary lymph node dissection in clinically node-negative breast cancer patients after neoadjuvant chemotherapy

Background: Concerns still remain about lower sentinel node (SN) detection and higher false-negative rates (FNR) in breast cancer patients treated with neoadjuvant chemotherapy (NAC), especially those who are clinically node-positive before NAC. It is necessary to analyze the validity of sentinel node biopsy (SNB) after NAC and evaluate whether the SN identification rate and FNR for clinically N0 (cN0) patients after NAC would be acceptable or not in order to omit axillary lymph node dissection (ALND).

Objectives and methods: We identified SN by radioisotopic methods followed by completion of ALND in cN0 patients after NAC from 2013 to 2016 as part of a clinical research study (SNB group, N=68) to analyze the accuracy of SNB, and retrospectively investigated the prognosis of patients treated with NAC from 2006 to 2012 (control group, N=92) to evaluate whether the validity of SNB would be acceptable or not.

Results: Mean patient ages in the SNB group and control group were 51.0 years and 49.5 years, respectively (p=0.17), and the distribution of intrinsic subtypes was not significantly different between the two groups. The numbers of cN1≤ before NAC in the SNB group and control group were 85.5% (57/68) and 80.4% (74/92), respectively (p=0.58), and the pathological complete response rates were 25.0% (17/68) and 19.6% (18/92), respectively (p=0.41). Lymphoscintigraphy using 99mTc-phytate acid was performed in the SNB group, and hot spots were detected at the ipsilateral axilla in 62 of 68 (91.2%) patients, in all of whom SNs could be identified by using a gamma-probe. The FNR, which indicates no metastasis in SNs and metastasis in non-SN, was 5.9% (4/68). Among these four patients, three were of the luminal type while one was triple negative. The number of patients without metastasis in both SN and non-SN, which are candidates for omission of ALND, was 26 of 68 (38.2%). They included eight of nine HER2-enriched patients and six of 13 luminal-HER2 patients. Conversely, there were no false-negative cases in these subtypes. Moreover, all SNs were identified even if there were metastases in SNs. Regarding the prognosis of the control group, the 10-year disease free survival of post-NAC N0 (ypN0) (52/92, 56.5%) and ypN1≤ (40/92, 43.5%) were 80.7% and 61.2%, respectively (p=0.08); in addition, the 10-year overall survival of yN0 and ypN1≤ were 90.4% and 72.6% (p=0.26). Thus, the prognosis of ypN1≤ was not significantly inferior to that of ypN0. If omission of ALND were performed for false negative cases, then the risk of axillary relapse would be a concern. However, these data indicate the possibility that 5.9% of FNR as shown in the SNB group would not have much influence on prognosis.

Conclusion: The accuracy of SN detection by radioisotopic methods for cN0 breast cancer after NAC was not maintained like that for -early breast cancer although it was better than the results of previous studies. However, there were no false-negative cases in HER2-enriched and luminal-HER2 subtypes, which could be potential candidates for omission of ALND. In addition, omission of ALND for false-negative patients would have less influence on the prognosis.

Citation Format: Maeno K, Yamamoto K, Ono M, Oba T, Iesato A, Ono K, Ito T, Kanai T, Ito K-I. A feasibility study of sentinel lymph node detection and analysis of safety to omit axillary lymph node dissection in clinically node-negative breast cancer patients after neoadjuvant chemotherapy [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-01-05.

Non-enhanced magnetic resonance imaging versus renal scintigraphy in acute pyelonephritis

The utility of non-enhanced magnetic resonance imaging (MRI) has not been examined extensively for diagnosing acute pyelonephritis (APN) in children. The aims of this study were to compare non-enhanced MRI with technetium-99 m dimercaptosuccinic acid (^99m Tc-DMSA) renal scintigraphy in detecting APN. Six boys and one girl with temperature ≥38°C and positive urine culture received both non-enhanced MRI with whole body diffusion-weighted imaging (DWI) and ^99m Tc-DMSA scintigraphy ≤7 days from the fever onset. The sensitivity and specificity of MRI in detecting APN lesions diagnosed on ^99m Tc-DMSA scintigraphy were 80% and 100%, respectively. Non-enhanced MRI in children with suspected APN ≤7 days from fever onset might be a suitable replacement for ^99m Tc-DMSA scintigraphy for the detection of APN.

Significance of measurement of serum trough level and anti-drug antibody of adalimumab as personalised pharmacokinetics in patients with Crohn's disease: a subanalysis of the DIAMOND trial

BACKGROUND

Significance of monitoring adalimumab trough levels and anti-adalimumab antibodies (AAA) for disease outcome in Crohn's disease (CD) patients remained unclear.

AIM

To evaluate the association of adalimumab trough levels and AAA at week 26 with clinical remission at week 52, the effect of azathiopurine on AAA and factors influencing trough levels in CD patients in the DIAMOND trial.

METHODS

We performed this study using adalimumab trough levels, AAA at week 26 and 6-thioguanine nucleotide (TGN) in red blood cells at week 12. A multiple regression model and receiver operating analysis was performed to identify factors influencing adalimumab trough levels and AAA, and adalimumab thresholds for predicting disease activity.

RESULTS

There was a significant difference of adalimumab trough level at week 26 between patients with disease remission and without at week 52 (7.7 ± 3.3 μg/mL vs 5.4 ± 4.3 μg/mL: P <.001). Adalimumab trough level of 5.0 μg/mL yielded optimal sensitivity and specificity for remission prediction (80.2% and 55.6%, respectively). AAA development at week 26 significantly affected remission at week 52 (P = .021), which was strongly associated with adalimumab trough levels. Female gender and increasing body weight were independently associated with low adalimumab trough levels, and female gender was associated with AAA development. A cut-off 6TGN level of >222.5 p mol/8 ×10⁸ RBCs yielded sensitivity (100%) and specificity (60.6%) for AAA negativity.

CONCLUSION

Adalimumab trough levels and AAA occurrence were significantly associated with clinical remission. Higher 6TGN affected AAA negativity. The combination therapy is beneficial in some relevant aspects for CD patients. (UMIN Registration No. 000005146).

Top-down approach is possible strategy for predicting breakthrough fUTIs and renal scars in infants

BACKGROUND

Acute-phase technetium-99 m dimercaptosuccinic acid (DMSA) scintigraphy is recommended for initial imaging in children with febrile urinary tract infection (fUTI). Recently, the importance of identifying patients at risk of recurrent fUTI (r-fUTI) has been emphasized. To clarify the effectiveness of DMSA scintigraphy for predicting r-fUTI in infants, we investigated the relationship between defects on DMSA scintigraphy and r-fUTI.

METHODS

Seventy-nine consecutive infants (male: female, 60:19) with fUTI were enrolled in this study. DMSA scintigraphy was performed in the acute phase, and patients with defect underwent voiding cystourethrography and chronic-phase (6 months later) DMSA scintigraphy. Patients were followed on continuous antibiotic prophylaxis (CAP).

RESULTS

Defects on acute-phase DMSA scintigraphy were observed in 32 children (40.5%) of 79. The mean follow-up observation period was 17.0 ± 10.1 months. Four patients had r-fUTI (5%). Two of them had defects on DMSA scintigraphy in both the acute phase and chronic phase, and had bilateral vesicoureteral reflux (VUR) grade IV. Two others had r-fUTI without defects on DMSA and did not have VUR. Twelve patients had defect on chronic-phase DMSA scintigraphy and four of them had no VUR.

CONCLUSIONS

The top-down approach is a possible method for predicting r-fUTI in infants and does not miss clinically significant VUR. Also, given that the prevalence of r-fUTI was 5% regardless of the presence of defects on acute-phase DMSA, then, in conjunction with genital hygiene and CAP, acute-phase DMSA might be unnecessary if chronic-phase DMSA is performed for all patients to detect renal scar.

Fluence correction factor for graphite calorimetry in a clinical high-energy carbon-ion beam

The aim of this work is to develop and adapt a formalism to determine absorbed dose to water from graphite calorimetry measurements in carbon-ion beams. Fluence correction factors, [Formula: see text], needed when using a graphite calorimeter to derive dose to water, were determined in a clinical high-energy carbon-ion beam. Measurements were performed in a 290 MeV/n carbon-ion beam with a field size of 11  ×  11 cm², without modulation. In order to sample the beam, a plane-parallel Roos ionization chamber was chosen for its small collecting volume in comparison with the field size. Experimental information on fluence corrections was obtained from depth-dose measurements in water. This procedure was repeated with graphite plates in front of the water phantom. Fluence corrections were also obtained with Monte Carlo simulations through the implementation of three methods based on (i) the fluence distributions differential in energy, (ii) a ratio of calculated doses in water and graphite at equivalent depths and (iii) simulations of the experimental setup. The [Formula: see text] term increased in depth from 1.00 at the entrance toward 1.02 at a depth near the Bragg peak, and the average difference between experimental and numerical simulations was about 0.13%. Compared to proton beams, there was no reduction of the [Formula: see text] due to alpha particles because the secondary particle spectrum is dominated by projectile fragmentation. By developing a practical dose conversion technique, this work contributes to improving the determination of absolute dose to water from graphite calorimetry in carbon-ion beams.

An Effective New Cryopreservation Procedure for Pancreatic Islets Using Hollow Fiber Vitrification

The present study aimed at establishing a new cryopreservation method for mouse pancreatic islets by vitrification using hollow fibers as a container. A unique feature of the hollow fiber vitrification (HFV) method is that this method achieves stable vitrification using a minimum volume of cryoprotectant (CPA) solution, thereby ensuring high viability of the islets. The cytotoxicity, optimum composition, and concentration of the CPAs for vitrifying islets were examined. The viability, functional-integrity of vitrified islets were evaluated in comparison with those vitrified by conventional methods. Insulin secretion was measured in vitro by a static incubation assay and the metabolic functions was tested after transplantation into Streptozotocin-induced diabetic mice. The combination of 15% dimethyl sulfoxide+15% ethylene glycol resulted in the best CPA solution for the HFV of islets. HFV showed the highest viability in comparison to 2 vitrification methods, open pulled straws and vitrification with EDT324 solution. The vitrified islets stably expressed β-cells markers NeuroD, Pancreatic and duodenal homeobox-1, and MafA. Transplantation of the vitrified islets achieved euglycemia of the host diabetic mice and response to an intraperitoneal glucose tolerance test to a similar extent as non-vitrified transplanted islets. The HFV method allows for efficient long-term cryopreservation of islets.

Surges in proteinuria are associated with plasma GL-3 elevations in a young patient with classic Fabry disease

Fabry disease is an X-linked glycosphingolipidosis caused by deficient synthesis of the enzyme α-galactosidase A, which results in accumulations of globotriaosylceramide (GL-3) in systemic tissues. Nephropathy is a dominant feature of Fabry disease. It still remains unclear how the nephropathy progresses. Recombinant agalsidase replacement therapy is currently the only approved, specific therapy for Fabry disease. The optimal dose of replacement enzyme also still remains unclear. The worldwide shortage of agalsidase-β in 2009 forced dose reduction of administration. It showed that the proteinuria emerged like surges, followed by temporary plasma GL-3 elevations in the early stages of classic Fabry disease. Additionally, it also showed that 1 mg/kg of agalsidase-β every other week could clear the GL-3 accumulations from podocytes and was required to maintain negative proteinuria and normal plasma GL-3 levels.

CONCLUSION

This observation of a young patient with classic Fabry disease about 5 years reveals that the long-term, low-dose agalsidase-β caused proteinuria surges, but not persistent proteinuria, followed by temporary plasma GL-3 elevations, and agalsidase-β at 1 mg/kg every other week could clear accumulated GL-3 from podocytes and was required to maintain normal urinalysis and plasma GL-3 levels.

Renal-limited necrotizing granulomatous vasculitis in a pediatric patient

A 10-year-old girl presented with mild proteinuria and hypertension. Laboratory data indicated slightly elevated serum creatinine (0.67 mg/dL) and elevated serum IgG (2111 mg/dL). On renal arteriography mild stenosis over the entire length of the right renal artery and irregular stenosis of the interlobar arteries in the right kidney were seen. She was diagnosed with renovascular hypertension, and received conventional anti-hypertensive therapy, but did not respond to them. The right kidney had atrophy and dysfunction on technetium-99m-labeled dimercaptosuccinic acid renal scintigraphy, and was therefore resected. Histopathology of the kidney indicated severe necrotizing granulomatous vasculitis affecting the arteries from the renal hilus to the interlobar area. After nephrectomy plus steroid pulse therapy, blood pressure and urinary protein returned to normal. To our knowledge, this is the first report of necrotizing granulomatous vasculitis limited to the medium-sized renal arteries.

Foot process effacement is an early marker of nephropathy in young classic Fabry patients without albuminuria

In Fabry disease, globotriaocylceramid (GL3) starts to accumulate in kidney cells in utero, and continues to accumulate throughout childhood and adulthood with progressive tissue damage, which may lead to renal failure.

MATERIAL AND METHODS

Eight children with classical Fabry disease, median age 12 (range 4-16 years) had a renal biopsy performed before the initiation of enzyme replacement therapy (ERT). All patients were normalbuminuric and had normal GFR. Three patients were re-biopsied after three or five years.

RESULTS

In all patients, significant GL3-accumulation was found in several types of kidney cells with high amounts of GL3 in the podocytes. Segmental podocyte foot process effacement was shown in all but two patients; no effacement was seen neither in the youngest male patient at 4 years of age nor in a male aged 12. A 12-year-old female patient had normal podocyte foot processes before the start of ERT, but de novo foot process flattening and unchanged high score of podocyte GL3 accumulation were seen in the re-biopsy after three years of ERT (agalsidase alpha 0.2 mg/kg/every other week). Two boys showed worsening of podocyte effacement in kidney biopsy after five years of agalsidase alpha 0.2 mg/kg/eow.

CONCLUSIONS

Podocyte foot process effacement was found in the majority of eight young classical Fabry patients of both genders after the age of 11 years, without clinical signs of Fabry nephropathy. Kidney biopsies are essential in the early diagnosis of nephropathy and in the evaluation of the response to enzyme replacement therapy of early Fabry nephropathy.

A case of post-pneumococcal acute glomerulonephritis with glomerular depositions of nephritis-associated plasmin receptor

We report the case of a 12-year-old girl who was referred to our hospital with anuria associated with pneumonia. On admission, the patient's blood test results revealed severe renal failure, hypoproteinemia, and hypocomplementemia. Her urinalysis results revealed hematuria, proteinuria, and a positive titer for Streptococcus pneumoniae. S. pneumoniae was also detected in her sputum and blood cultures. The patient was diagnosed with post-pneumococcal acute glomerulonephritis (AGN) with acute renal failure. A renal biopsy demonstrated the infiltration of neutrophils and mononuclear cells into capillary loops. Immunofluorescence studies showed dominant-positive deposition of C3c along the capillary loops and nephritis-associated plasmin receptor (NAPlr) depositions in the mesangial area and capillary loops. Electron microscopy revealed dense deposits in the glomerular basement membrane without a hump in the subepithelial area. These findings were consistent with endocapillary proliferative glomerulonephritis. AGN associated with pneumococcal infection is very rare. This case suggests that NAPlr is the causative antigen not only of post-streptococcal AGN, but also of post-pneumococcal AGN. To our knowledge, this is the first report that shows a relationship between post-pneumococcal AGN and NAPlr depositions in the glomeruli.

Serum cytokine and chemokine profiles in patients with myasthenia gravis

Myasthenia gravis (MG) is an autoimmune-mediated inflammatory disease of the neuromuscular junction. Previous studies of animal MG models have suggested important roles of cytokines in MG pathogenesis, but adequate studies on cytokines in human MG are lacking. Using a multiplex suspension array system, we measured the serum levels of 27 cytokines/chemokines in 47 anti-acetylcholine receptor antibody-positive patients with MG and 20 normal controls (NC) to investigate the contribution of cytokines/chemokines toward MG pathogenesis. Correlations between clinical parameters and cytokine/chemokine levels in patients with MG were also examined. The serum levels of interleukin (IL)-15 (mean ± standard deviation: 6·85 ± 6·97 pg/ml) and vascular endothelial growth factor (VEGF) (96·21 ± 71·60 pg/ml) significantly increased, whereas IL-4 levels (3·57 ± 0·86 pg/ml) decreased in patients with MG compared with NC (IL-15: 4·42 ± 1·55 pg/ml; VEGF: 63·51 ± 32·95 pg/ml; IL-4: 4·15 ± 0·81 pg/ml, P < 0·05). In addition, eight cytokines (IL-4, IL-8, IL-15, eotaxin, macrophage inflammatory protein-1α, macrophage inflammatory protein-1β, VEGF and IL-1b) were significantly changed among MG patients with thymoma, MG patients without thymoma and NC (P < 0·05). Some cytokines, such as IL-4, IL-15, and VEGF, may play roles in the pathogenesis of MG.

Utility of non-enhanced magnetic resonance imaging to detect acute pyelonephritis

It has been established that enhanced computed tomography (CT) and (99m) Tc-dimercaptosuccinic acid renal scintigraphy ((99m) Tc-DMSA scintigraphy) used in conjunction with single-photon emission CT is a useful tool for the diagnosis of acute pyelonephritis (APN). The utility of non-enhanced magnetic resonance imaging (MRI), however, has not been investigated extensively for the diagnosis of APN or renal abscess in children. We describe the case of a 23-month-old boy with suspected APN who received non-enhanced MRI. Whole body diffusion-weighted imaging (DWI) was used, and a background body-signal suppression sequence was applied. High-intensity focal lesions were identified on DWI and low-intensity lesions on the apparent diffusion coefficient map in the acute phase. This case suggested that non-enhanced MRI could be a useful tool for the diagnosis of APN in children, because it can avoid the risks of not only radiation exposure but also nephrogenic systemic fibrosis associated with gadolinium-based contrast agents, especially in infants.

Cytokine dynamics in a 14-year-old girl with tubulointerstitial nephritis and uveitis syndrome

Tubulointerstitial nephritis and uveitis (TINU) syndrome, which was first described in 1975, has been reported in more than 130 patients, mostly in adolescent or young women. Although data concerning the etiologic background of this inflammatory disease are limited, several humoral factors, including cytokines, have been reported in association with the disease. Here, we report a case of TINU in a 14-year-old girl, whose renal and ophthalmological improvement was associated with the decrease of serum levels of tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), and interleukin-8 (IL-8). This suggests the presence of T-cell-mediated immunity in this unique syndrome.

Transgenic pigs with pancreas-specific expression of green fluorescent protein

The development and regeneration of the pancreas is of considerable interest because of the role of these processes in pancreatic diseases, such as diabetes. Here, we sought to develop a large animal model in which the pancreatic cell lineage could be tracked. The pancreatic and duodenal homeobox-1 (Pdx1) gene promoter was conjugated to Venus, a green fluorescent protein, and introduced into 370 in vitro-matured porcine oocytes by intracytoplasmic sperm injection-mediated gene transfer. These oocytes were transferred into four recipient gilts, all of which became pregnant. Three gilts were sacrificed at 47-65 days of gestation, and the fourth was allowed to farrow. Seven of 16 fetuses obtained were transgenic (Tg) and exhibited pancreas-specific green fluorescence. The fourth recipient gilt produced a litter of six piglets, two of which were Tg. The founder Tg offspring matured normally and produced healthy first-generation (G1) progeny. A postweaning autopsy of four 27-day-old G1 Tg piglets confirmed the pancreas-specific Venus expression. Immunostaining of the pancreatic tissue indicated the transgene was expressed in β-cells. Pancreatic islets from Tg pigs were transplanted under the renal capsules of NOD/SCID mice and expressed fluorescence up to one month after transplantation. Tg G1 pigs developed normally and had blood glucose levels within the normal range. Insulin levels before and after sexual maturity were within normal ranges, as were other blood biochemistry parameters, indicating that pancreatic function was normal. We conclude that Pdx1-Venus Tg pigs represent a large animal model suitable for research on pancreatic development/regeneration and diabetes.

Apolipoprotein AII levels are associated with the UP/UCr levels in idiopathic steroid-sensitive nephrotic syndrome

BACKGROUND

Various humoral factors have been proposed as causal agents of idiopathic steroid-sensitive nephrotic syndrome (ISSNS), resulting in varying data. We used mass spectrometry (MS) to analyze serum proteins in a search for proteins that might be involved in ISSNS pathophysiology.

METHODS

Serial serum samples were obtained from 33 children with ISSNS. Samples were collected during Phase A1 [the acute phase prior to steroid treatment (STx)], Phase A2 (remission with STx), and Phase A3 (remission without any medication). We also included age- and sex-matched two control groups comprising children with normal urinalysis (Group B) and children with a nephrotic syndrome other than ISSNS (Group C). The urinary protein/urinary creatinine (UP/UCr) ratios were not statistically different between Phase A1 and Group C. Samples were analyzed using surface-enhanced laser desorption/ionization time of flight MS.

RESULTS

A total of 207 peptide ion peaks were detected in the range of m/z 2000-10000. Four peptide ions (m/z 6444, 6626, 8695, and 8915) were detected at significant elevation during Phase A1 compared with Phase A2, Phase A3, and Group C. The intensities of m/z 6444 and 8695 were higher in Phase A3 than in Group B. There were significant correlations between the intensities of m/z 6626, 8695, and 8915 and UP/UCr levels. The m/z 8695 was identified as apolipoprotein AII.

CONCLUSIONS

Apolipoprotein AII was detected as a protein associated with the UP/UCr levels in pediatric ISSNS. Our findings present an interesting starting point for further investigation into the pathophysiology of ISSNS.

Operation status of the electron cyclotron resonance ion source at Gunma University

An ECR ion source of Gunma University Heavy Ion Medical Center, so-called KeiGM [M. Muramatsu, A. Kitagawa, Y. Sakamoto, S. Sato, Y. Sato, H. Ogawa, S. Yamada, H. Ogawa, Y. Yoshida, and A. G. Drentje, Rev. Sci. Instrum. 76, 113304 (2005)], has been operated for cancer therapy and physical/biological experiment since 2010. KeiGM produces typically 230 μA of 10 keV/u C(4+) ions from CH4 gases. The vacuum pressure is kept between 1.2 × 10(-4) and 1.7 × 10(-4) Pa so as to suppress the pulse-to-pulse current fluctuation within ±10%. The extraction electrode is cleaned every 6-8 months in order to remove deposited carbon, which increases the leak current and discharge. In order to investigate the possibility of long-term operation without such maintenances, oxygen aging for the cleaning of the extraction electrode has been tested in the test bench. The same-designed ion sources at National Institute of Radiological Sciences and SAGA Heavy Ion Medical Accelerator in Tosu (SAGA-HIMAT) are also operated with stable C(4+) current, which are suitable for the continuous operation for cancer therapy.

Identification of STAT5A and STAT5B target genes in human T cells

Signal transducer and activator of transcription (STAT) comprises a family of universal transcription factors that help cells sense and respond to environmental signals. STAT5 refers to two highly related proteins, STAT5A and STAT5B, with critical function: their complete deficiency is lethal in mice; in humans, STAT5B deficiency alone leads to endocrine and immunological problems, while STAT5A deficiency has not been reported. STAT5A and STAT5B show peptide sequence similarities greater than 90%, but subtle structural differences suggest possible non-redundant roles in gene regulation. However, these roles remain unclear in humans. We applied chromatin immunoprecipitation followed by DNA sequencing using human CD4⁺ T cells to detect candidate genes regulated by STAT5A and/or STAT5B, and quantitative-PCR in STAT5A or STAT5B knock-down (KD) human CD4⁺ T cells to validate the findings. Our data show STAT5A and STAT5B play redundant roles in cell proliferation and apoptosis via SGK1 interaction. Interestingly, we found a novel, unique role for STAT5A in binding to genes involved in neural development and function (NDRG1, DNAJC6, and SSH2), while STAT5B appears to play a distinct role in T cell development and function via DOCK8, SNX9, FOXP3 and IL2RA binding. Our results also suggest that one or more co-activators for STAT5A and/or STAT5B may play important roles in establishing different binding abilities and gene regulation behaviors. The new identification of these genes regulated by STAT5A and/or STAT5B has major implications for understanding the pathophysiology of cancer progression, neural disorders, and immune abnormalities.

26 IN VIVO EXOGENIC ORGAN GENERATION WITH ORGANOGENESIS-DISABLED CLONED PIGS AS A PLATFORM

The generation of organs from pluripotent stem cells (PSC) is one of the ultimate goals of regenerative medicine. We have demonstrated that functional organs can be generated in vivo from xenogenic PSC in the body of organogenesis-disabled mice using blastocyst complementation. To apply this principle in generating human organs, a technical platform using large non-rodent mammals is essential. The aim of the present study was to establish a blastocyst complementation system using cloned pig embryos. We generated transgenic-cloned pigs with an apancreatic phenotype via the overexpression of Hes1 (hairy and enhancer of split-1) under the Pdx1 promoter (pancreatic and duodenal homeobox-1). Cloned embryos of apancreatic pigs (host embryos, male) were complemented (i.e. chimerized) by blastomeres of cloned embryos (donor cells, female) with normal developmental competence. Chimeric embryos were cultured for 1 or 2 days before being transferred into the uteri of oestrus-synchronized gilts. The complementation of 292 Pdx1-Hes1 cloned embryos gave rise to 260 (89.0%) blastocysts. The transfer of these blastocysts resulted in 5 male chimeric pigs. Chimerism was confirmed by the detection of host embryo-derived Pdx1-Hes1 and marker transgenes of the donor cells, such as humanized Kusabira-Orange (huKO) or Pdx1-Venus. Chimeric pigs possessed normally formed pancreata entirely derived from the exogenous donor cells. We thus established a blastocyst complementation system in the pig using cloned embryos that would otherwise give rise to apancreatic animals. Chimeric pigs obtained developed normally, maintaining normal serum glucose concentrations up to maturity, and became fertile boars. Mating the chimeric boars with 7 wild-type sows gave rise to 72 fetuses/piglets of which 37 (51.4%) exhibited the apancreatic phenotype. These results indicate that a missing organ can be generated from exogenous cells when functionally normal pluripotent cells chimerize with a cloned dysorganogenetic embryo. Blastocyst complementation using cloned porcine embryos may permit the use of a large animal for the generation of functional organs from xenogenic PSC, including human iPSC. The chimeric boar produced by blastocyst complementation sired fetuses/offspring with the apancreatic phenotype in a Mendelian fashion. Porcine fetuses with an organogenesis-disabled phenotype may provide a useful platform for organ regeneration research. Table 1.Production of chimeric pigs by complementation and of Pdx1-Hes1 cloned embryos

20 GENERATION AND CHARACTERIZATION OF TRANSGENIC-CLONED PIGS EXPRESSING THE FAR-RED FLUORESCENT PROTEIN MONOMERIC PLUM

Transgenic (Tg) pigs expressing a fluorescent protein are extremely useful for research into transplantation and regenerative medicine. This study aimed to create Tg pigs expressing monomeric Plum (mPlum), a far-red fluorescent protein with a longer wavelength than enhanced green fluorescent protein (EGFP) and humanized Kusabira Orange (huKO), the two fluorescent proteins that have been used previously for Tg pig production. A linearized CAG-mPlum transgene construct was transferred into porcine fetal fibroblasts (PFF) by electroporation. mPlum fluorescence-positive cells were collected using a cell sorter and used as nuclear donors (mPlum-PFF) for somatic cell nuclear transfer (SCNT). In vitro-matured oocytes were obtained from porcine cumulus–oocyte complexes cultured in NCSU23-based medium and were used to obtain recipient oocytes for SCNT after enucleation. Then, SCNT was performed as reported previously (Matsunari et al., 2008). The reconstructed embryos were cultured for 7 days in porcine zygote medium-5 (PZM-5). mPlum fluorescence expression was screened during the early development of the embryos. After 5 or 6 days of culture, the SCNT embryos were surgically transferred to the uterus of a recipient gilt. We first obtained fetuses on Day 36 or 37 of gestation by Caesarean section and the PFF were retrieved from their skin. Fluorescence expression was analysed using fluorescence microscope, and the number of transgene copies in each fetus was determined by Southern blot analysis. We also analysed whether unique spectral properties of mPlum are suitable for multicolor imaging using confocal microscope and flow cytometer. The identification of mPlum-expressing PFF under the mixed culture of PFF expressing EGFP and huKO was examined. The 2 cell lines of PFF expressing EGFP and huKO were previously generated in our laboratory. Rates of normal cleavage and blastocyst formation occurred in the SCNT embryos generated with mPlum-PFF (mPlum embryos) were equivalent to those of SCNT embryos derived from nontransgenic PFF (34/42, 81.0%; 33/42, 78.6% v. 37/40, 92.5%; 30/40, 75.0%). Total cell numbers in mPlum and control blastocysts did not differ significantly (88.3 ± 6.0 v. 99.9 ± 8.8). Fluorescence expression in the mPlum embryos began at the 8-cell stage and became brighter from the morula stage. The gilt into which 103 mPlum embryos were transferred produced 3 fetuses. These fetuses expressed mPlum fluorescence systemically and had 1 to 5 copies of the transgene. Multicolor fluorescence imaging and flow cytometric analyses of a mixed culture of mPlum PFF and PFF expressing EGFP and huKO showed that clear identification and isolation of cells displaying each of the 3 fluorescence signals was possible. These observations demonstrate that the transfer of CAG-mPlum did not interfere with the development of porcine SCNT embryos and resulted in the successful generation of Tg cloned pigs that systemically expressed mPlum. This work was supported by JSPS KAKENHI Grant Number 25293279.

Generation of interleukin-2 receptor gamma gene knockout pigs from somatic cells genetically modified by zinc finger nuclease-encoding mRNA

Zinc finger nuclease (ZFN) is a powerful tool for genome editing. ZFN-encoding plasmid DNA expression systems have been recently employed for the generation of gene knockout (KO) pigs, although one major limitation of this technology is the use of potentially harmful genome-integrating plasmid DNAs. Here we describe a simple, non-integrating strategy for generating KO pigs using ZFN-encoding mRNA. The interleukin-2 receptor gamma (IL2RG) gene was knocked out in porcine fetal fibroblasts using ZFN-encoding mRNAs, and IL2RG KO pigs were subsequently generated using these KO cells through somatic cell nuclear transfer (SCNT). The resulting IL2RG KO pigs completely lacked a thymus and were deficient in T and NK cells, similar to human X-linked SCID patients. Our findings demonstrate that the combination of ZFN-encoding mRNAs and SCNT provides a simple robust method for producing KO pigs without genomic integration.

Development of a novel vitrification method for chondrocyte sheets

Background

There is considerable interest in using cell sheets for the treatment of various lesions as part of regenerative medicine therapy. Cell sheets can be prepared in temperature-responsive culture dishes and applied to injured tissue. For example, cartilage-derived cell sheets are currently under preclinical testing for use in treatment of knee cartilage injuries. The additional use of cryopreservation technology could increase the range and practicality of cell sheet therapies. To date, however, cryopreservation of cell sheets has proved impractical.

Results

Here we have developed a novel and effective method for cryopreserving fragile chondrocyte sheets. We modified the vitrification method previously developed for cryopreservation of mammalian embryos to vitrify a cell sheet through use of a minimum volume of vitrification solution containing 20% dimethyl sulfoxide, 20% ethylene glycol, 0.5 M sucrose, and 10% carboxylated poly-L-lysine. The principal feature of our method is the coating of the cell sheet with a viscous vitrification solution containing permeable and non-permeable cryoprotectants prior to vitrification in liquid nitrogen vapor. This method prevented fracturing of the fragile cell sheet even after vitrification and rewarming. Both the macro- and microstructures of the vitrified cell sheets were maintained without damage or loss of major components. Cell survival in the vitrified sheets was comparable to that in non-vitrified samples.

Conclusions

We have shown here that it is feasible to vitrify chondrocyte cell sheets and that these sheets retain their normal characteristics upon thawing. The availability of a practical cryopreservation method should make a significant contribution to the effectiveness and range of applications of cell sheet therapy.

Scale-up Rule for Double Bubble Tubular Process of PA6 Film

The analysis of scale-up rule for double bubble tubular film process of PA6 was investigated. The scale-up rule previously proposed for a blown film process by the authors was applied to a double bubble tubular film process with a small-scale plant for research (pilot plant) and a large-scale plant for commercial production (production plant).

According to the scale-up rule based on the equivalent stretching stress between the pilot and production plants, the equivalence of stretching stability, birefringence pattern and deformation pattern were confirmed.

It has been confirmed that the proposed scale-up rule is applicable to predict the physical properties such as film impact strength and the bubble stability for the large-scale tubular film process on the basis of the experimental results obtained from the pilot plant.

Dynamics of Double Bubble Tabular Film Process for Producing Biaxially oriented Nylon 6 Film

A double bubble tubular film process for nylon 6 was investigated. This report discussed three topics: Relationship between process conditions and film stretching stresses; deformation rate during double bubble process, birefringence and film thickness uniformity; and scale-up rule for double bubble tubular film process. The optimum stretching stress during the double bubble tubular film process exists. The bubble break occurs over stress of 1300 Kg/cm2 and bubble stability occurs below stress of 600 Kg/cm2. The cross point of stretching stress, which means stress in the machine direction is equal to stress in the transverse direction, is influenced by a deformation rate which is closely related to birefringence and bubble stability. Bubble stability and film thickness uniformity are improved with increasing deformation rate. It is found that the scale-up rule which was set up theoretically is applicable to predict the physical properties and bubble stability for large scale double bubble tubular film process once the same process is carried out by using the same scale machine and a small amount of resin.

Prediction of Birefringence for Optical Memory Disk

Polycarbonate (PC) is considered to be a proper resin for optical memory disk, however PC resin shows high birefringence. It is very important to reduce birefringence of PC optical memory disk. This research is to obtain the relationship between birefringence and process conditions and to get the optimum condition for the production of low birefringence substrate of PC optical memory disk. The birefringence distribution of PC optical memory disk was theoretically predicted by the calculations of both the stress distribution caused by molecular orientation during the filling stage and the thermal stress caused by temperature difference during the cooling stage. The relationship between birefringence distribution and the process conditions such as rheological properties of PC resin, injection temperature, mold temperature, mold design and annealing condition is possible to be predicted theoretically by calculating shear stress during the injection process and thermal stress during the cooling process. The predicted results of birefringence distribution qualitatively agree with the experimental ones.