Low-Temperature Thermal Conductivity of Rubrene Single Crystals: Quantitative Estimation of Defect Density in Bulk and Film Crystals

Thermal conductivity of rubrene single crystals is measured for both bulk and film-like crystals down to 0.5 K in order to estimate quantitatively density of crystalline defects through their phonon mean free paths. The temperature profile of the bulk rubrene crystals exhibit pronounced peak at ∼ 10 K in the thermal conductivity as the result of very long mean-free paths of their phonons which indicates extremely low-level defect density in the region of 1015-1016 cm−3 depending on different growth methods. The crystals grown from gas phase tend to have less defects than those grown from solution. It turned out that the film-like crystals have a few times more defect density as the result of the measurement by using newly developed devices for minute crystals.

Mitochondrial DNA depletion and its correlation with TFAM, TFB1M, TFB2M and POLG in human diffusely infiltrating astrocytomas

Mitochondrial DNA (mtDNA) alterations and their clinical and pathological implications have been analyzed in several human malignancies. A marked decrease in mtDNA copy number along with the increase in malignancy was observed in diffusely infiltrating astrocytomas (24 WHO grade II, 18 grade III, and 78 grade IV or GBM) compared to non-neoplastic brain tissues, being mostly depleted in GBM. Although high relative gene expression levels of mtDNA replication regulators (mitochondrial polymerase catalytic subunit (POLG), transcription factors A (TFAM), B1 (TFB1M) and B2 (TFB2M)) were detected, it cannot successfully revert the mtDNA depletion observed in our samples. On the other hand, a strong correlation among the expression levels of mitochondrial transcription factors corroborates with the TFAM role in the direct control of TFB1M and TFB2M during initiation of mtDNA replication. POLG expression was related to decreased mtDNA copy number, and its overexpression associated with TFAM expression levels also have an impact on long-term survival among GBM patients, interpreted as a potential predictive factor for better prognosis.

A human anti-CD40 monoclonal antibody, 4D11, for kidney transplantation in cynomolgus monkeys: induction and maintenance therapy

Blockade of CD40-CD154 signaling pathway is an attractive strategy to induce potent immunosuppression and tolerance in organ transplantation. Due to its strong immunosuppressive effect shown in nonhuman primate experiments, anti-CD154 monoclonal antibodies (mAbs) have been tried in clinical settings, but it was interrupted by unexpected thromboembolic complications. Thus, inhibition of the counter molecule, CD40, has remained an alternative approach. In the previous preliminary study, we have shown that 4D11, a novel fully human anti-CD40 mAb, has a fairly potent immunosuppressive effect on kidney allograft in nonhuman primates. In this study, we aimed to confirm the efficacy and untoward events of the 2-week induction and 180-day maintenance 4D11 treatments. In both, 4D11 significantly suppressed T-cell-mediated alloimmune responses and prolonged allograft survival. Addition of weekly 4D11 administration after the induction treatment further enhanced graft survival. Complete inhibition of both donor-specific Ab and anti-4D11 Ab productions was obtained only with higher-dose maintenance therapy. No serious side effect including thromboembolic complications was noted except for a transient reduction of hematocrit in one animal, and decrease of peripheral B-cell counts in all. These results indicate that the 4D11 appears to be a promising candidate for immunosuppression in clinical organ transplantation.

Experimental nodel of C6 brain tumors in athymic rats

Malignant brain tumor experimental models tend to employ cells that are immunologically compatible with the receptor animal. In this study, we have proposed an experimental model of encephalic tumor development by injecting C6 cells into athymic Rowett rats, aiming at reaching a model which more closely resembles to the human glioma tumor. In our model, we observed micro-infiltration of tumor cell clusters in the vicinity of the main tumor mass, and of more distal isolated tumor cells immersed in normal encephalic parenchyma. This degree of infiltration is superior to that usually observed in other C6 models.

Does the permanent portacaval shunt for a small-for-size graft in a living donor liver transplantation do more harm than good?

In order to obviate a small-for-size graft syndrome (SFSGS), a portacaval (PC) shunt had been considered in a case of adult-to-adult living donor liver transplantation (AA-LDLT). In a recent AA-LDLT case, we adopted the PC shunt to resolve SFSGS; however, graft atrophy was observed in the late period of LDLT, thereby resulting in liver dysfunction. Due to the surgical closure of the PC shunt at 11 months post-LDLT, the graft regenerated gradually and resulted in the recovery of the liver function. This experience indicates that the portacaval shunt would overcome SFSGS in the early period of LDLT, while it would cause the graft atrophy and the graft dysfunction in the late period of LDLT.

Clinical significance of epidermal growth factor receptor gene mutations on treatment outcome after cytotoxic chemotherapy in Japanese patients with non-small cell lung cancer (NSCLC)

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Background: The relationship between EGFR mutation status and clinical outcome has not fully been assessed in NSCLC patients receiving cytotoxic agents. The aim of this study was to clarify its association. We also examined if this association could be affected by the prior gefitinib treatment or not. Methods: Patients with advanced or postoperative recurrent NSCLC who received both cytotoxic chemotherapy and gefitinib monotherapy through their treatment course and whose tumors were assessable for EGFR mutation analysis were included in this study. EGFR mutation was determined in exons 19 and 21 by direct sequencing. Results: Sixty patients were included in the study, including 6 (10%) patients who received the first-line gefitinib monotherapy followed by cytotoxic chemotherapy in the second-line or later settings. Of the 54 (90%) patients, 22 also underwent subsequent cytotoxic chemotherapy after the relapse to gefitinib monotherapy. EGFR mutations were detected in 17 (28%) patients. In the first-line cytotoxic chemotherapy setting (n=54), EGFR mutations significantly affected progression-free survival (PFS) with 6-month PFS rates of 45.8 vs. 21.9% (p=0.05). This was also observed in the multivariate analysis (HR=0.42, p=0.04). EGFR mutation was also significantly correlated with overall survival (OS) in the multivariate analysis (HR=0.26, p <0.01). Contrary, in the 28 (47%) of 60 patients who received cytotoxic chemotherapy after gefitinib monotherapy, there were no differences in PFS stratified by EGFR mutation status. The sensitivity to gefitinib was, however, correlated with EGFR mutation status and its sensitivity was retained even in the second-line setting in patients with EGFR mutations. Conclusion: EGFR mutation was significantly associated with better PFS in the first-line cytotoxic chemotherapy regimens. However, its association was not observed in the cytotoxic regimens administered after the relapse to gefitinib monotherapy, while the sensitivity to gefitinib was associated with EGFR mutation even in the second-line or later setting.

No significant financial relationships to disclose.

Diagnosis of acute brain-stem infarcts using diffusion-weighed MRI

There are many reports on acute cerebral infarcts diagnosed by diffusion-weighted MRI (DWI), but few describe brain-stem infarcts diagnosed by this method. Using the apparent diffusion coefficient (ADC), we studied 18 consecutive patients with brain-stem infarcts who underwent DWI during the acute phase. We calculated and compared the ADC ratio (lesion ADC/contralateral ADC) in 10 patients with brain-stem and 23 with supratentorial cortical infarcts examined within 24 h of the onset of stroke. Ischaemic brain-stem lesions were detected in all 15 patients who underwent DWI more than 3 h after the onset, but not in two who had DWI within 3 h of the onset; their ADC ratio was more than 0.95. ADC ratios in patients with brain-stem infarcts decreased as the interval between onset and DWI increased; the decrease was slower than in patients with supratentorial cortical infarcts.

Raised plasma oxidised LDL in acute cerebral infarction

BACKGROUND

The association between oxidised low density lipoprotein (OxLDL) and cerebral infarction is suspected but not established.

OBJECTIVES

To determine whether plasma OxLDL is a useful marker for monitoring oxidative stress in stroke patients.

METHODS

Plasma OxLDL concentrations were determined in 56 stroke patients with cerebral infarction (n = 45) or cerebral haemorrhage (n = 11), and in 19 age matched controls, using a novel sandwich enzyme linked immunosorbent assay.

RESULTS

Compared with the controls (0.130 (0.007) ng/ micro g LDL, mean (SEM)), OxLDL was significantly raised in patients with cerebral infarction (0.245 (0.022); p < 0.0001) but not in those with haemorrhage (0.179 (0.023)). Patients with cortical ischaemic infarcts (n = 22) had higher OxLDL levels than either the controls (p < 0.0001) or the patients with non-cortical ischaemic infarcts (n = 23) (p < 0.001). Increased OxLDL concentrations in patients with cortical infarcts persisted until the third day after stroke onset. The National Institutes of Health stroke scales in patients with cortical infarction were higher than in those with non-cortical infarction (p < 0.01).

CONCLUSIONS

There is a significant association between raised plasma OxLDL and acute cerebral infarction, especially cortical infarction. Plasma OxLDL may reflect oxidative stress in stroke patients.

Long-term therapeutic effects of voglibose, a potent intestinal alpha-glucosidase inhibitor, in spontaneous diabetic GK rats

The effect of long-term (6 months) administration of voglibose in a dietary mixture (10 ppm) on intestinal disaccharidase activity was examined in non obese type 2 diabetes model Goto-Kakizaki (GK) rats. The postprandial blood glucose level in voglibose-treated GK rats was significantly lower than in untreated GK rats (190+/-19 vs. 250+/-25 mg/dl, P<0.01; 1 h, 212+/-23 vs. 256+/-20, P<0.05; 2 h), and the activities of maltase, sucrase, and isomaltase remained significantly lower throughout the 6 months of voglibose treatment. The expressions of protein and mRNA of sucrase-isomaltase (SI) complex were significantly higher in voglibose-treated GK rats. Voglibose administration then was stopped after 6 months of treatment. The mRNA level and protein level of the SI complex became normalized during the interruption of drug administration, and disaccharidase activities increased almost to the level of the untreated group 1 month after treatment was stopped. After 1 day of re-administration of the drug, however, disaccharidase activities again became significantly inhibited. These results indicate that voglibose may improve glucose tolerance since it inhibits activities of disaccharidases in spite of increasing the expression of them on intestine, furthermore voglibose may be reversible and reproducible through interruption and re-administration.

A characteristic feature of acute haematomas in the brain on echo-planar diffusion-weighted imaging

Diffusion-weighted MRI (DWI) is used in the diagnosis of acute ischaemic disease of the brain, but it is not clear whether or not it can be used to differentiate an acute haematoma from an infarct. Our purpose was to identify any characteristic feature of acute haematomas which can be recognised on DWI and to evaluate the usefulness of DWI in acute cerebral stroke. We examined nine patients with acute haemorrhage using CT and MRI including DWI. We measured the volume and apparent diffusion coefficient (ADC) of the haematomas. All showed heterogeneous signal on DWI, and the centre of the large (>20 ml) haematomas especially a mixed pattern with high and low signal. The characteristic feature of acute haematomas was a peripheral low-signal region, found in all subjects regardless of the size of the haematoma; acute infarcts did not show this. This low-signal rim on DWI may be useful for differentiating an acute haematoma from an infarct.

Helicobacter pylori seropositivity among 963 Japanese Brazilians according to sex, age, generation, and lifestyle factors

Seropositivity of anti-Helicobacter pylori antibody (HP + ) was examined among Japanese Brazilians. The study was announced through 18 Japanese community culture associations in São Paulo, Curitiba, Mogi das Cruzes, and Mirandopolis in 2001. Among 969 participants, 963 individuals aged 33 - 69 years were analyzed. The overall HP + % was 48.1% (95% confidence interval, 44.9 - 51.3%). There was no difference in HP + % between 399 males and 564 females (49.6% and 47.0%, respectively). The HP + % increased with age; 35.3% for those aged 33 - 39 years, 46.2% for those aged 40 - 49 years, 46.5% for those aged 50 - 59 years, and 56.9% for those aged 60 - 69 years, but no differences were observed among the generations (Issei, Nisei, and Sansei) for each 10-year age group. Mogi das Cruzes, a rural area, showed a higher HP + %. Length of education was inversely associated with the positivity; the odds ratio (OR) relative to those with eight years or less of schooling was 0.61 (0.42 - 0.89) for those with 12 years or more. The associations with smoking and alcohol drinking were not significant. Fruit intake was associated with the HP + %; the OR relative to everyday intake was 1.38 (1.05 - 1.83) for less frequent intake, while intake frequencies of green tea, miso soup, and pickled vegetables (tsukemono) were not. Multivariate analysis including sex, 10-year age group, residence, education, and fruit intake showed that all factors except sex were significant. This is the largest study of HP infection among Japanese Brazilians, and the results indicated a similar pattern of age-specific infection rate to that for Japanese in Japan.

Anti-HER2-antibody enhances irradiation-induced growth inhibition in head and neck carcinoma

To explore the antiproliferative effects of rhumAbHER2 on head and neck squamous carcinoma cell (HNSCC) lines and breast cancer cell lines (BCCLs) and to evaluate the combined effects with irradiation, 2 human HNSCC lines and 2 BCCLs were exposed to rhumAbHER2 with or without irradiation. The results showed that combined treatment enhanced the growth and colonization inhibitory effects of rhumAbHER2 or irradiation. Interestingly, the apoptotic cell fraction produced by irradiation disappeared on combined treatment. This disappearance was associated with repression of p53 and Bax upregulation induced by irradiation, but conservation of the upregulation of p27. Based on these results, rhumAbHER2 and irradiation may be a new strategy for treating HNSCC and breast cancers. In addition, the upregulation of cyclin-dependent kinase inhibitors by rhumAbHER2 may occur upstream of irradiation-induced p53 upregulation.

Guglielmi detachable coil embolization for ruptured lower-midbasilar trunk aneurysms--a report of five cases

Detachable coil embolization currently plays an essential role for patients with ruptured basilar artery aneurysms, even though it may have an unfavorable outcome and there may be some technical problems of embolization. We describe Guglielmi detachable coil (GDC) embolization for five ruptured lower-mid basilar trunk aneurysms, using a variety of techniques. The patients' ages ranged from 61 to 78 years; Hunt and Kosnik grade was distributed from 2 to 4, and three patients were found to have fenestrations of the lower basilar arteries. All patients underwent aneurysmal embolization at the subacute or chronic stage. The transfemoral route was used in three patients--one of whom, with a wide-necked aneurysm, was treated by the balloon remodeling technique. The transbrachial approach was chosen for the fourth patient, while vertebral artery origin exposure followed by a direct puncture was achieved in the fifth. All patients were assessed with 80-100% aneurysmal obliteration. No patient re-bled after the embolization. Small cerebellar infarction, possibly due to embolism from the obliterated aneurysmal sac, occurred 11 days after the treatment. Of the five patients, four achieved a good recovery, and one became severely disabled. Ruptured basilar trunk aneurysms can be successfully treated with GDC embolization. In addition to the routine transfemoral route, the transbrachial route, direct vertebral artery puncture, and balloon remodeling technique are also useful for the embolization of this location of aneurysm.

Changes in brain morphology in Alzheimer disease and normal aging: is Alzheimer disease an exaggerated aging process?

BACKGROUND AND PURPOSE

Whether Alzheimer disease (AD) represents exaggerated aging rather than a disease is controversial. Data about the effects of normal aging on the human brain are essential for clarifying this issue; however, whether coherent common patterns of regional morphologic brain changes emerge in the normal aged brain is unclear. Clarification of regional morphologic changes in the brain associated with normal aging and AD was sought using MR imaging.

METHODS

Ninety-two healthy volunteers and 26 mildly to moderately impaired patients with AD participated. Images were anatomically normalized, and voxel-by-voxel analyses were done.

RESULTS

In healthy volunteers, an age-related decline in the volume of the prefrontal cortex, insula, anterior cingulate gyrus, superior temporal gyrus, inferior parietal lobule, and precuneus was found. These decreases might contribute to the cognitive changes during normal aging. In patients with AD, a significant reduction of gray matter volume in the hippocampal formation and entorhinal cortex bilaterally was noted.

CONCLUSION

Morphologic changes associated with normal aging are clearly different from those seen with AD.

Donepezil hydrochloride preserves regional cerebral blood flow in patients with Alzheimer's disease

The aim of this SPECT study was to investigate the effects of donepezil on regional cerebral blood flow (rCBF) in patients with mild to moderate Alzheimer's disease (AD) using statistical parametric mapping.

METHODS

rCBF was noninvasively measured using (99m)Tc-ethyl cysteinate dimer in 35 AD patients with a Mini-Mental State Examination score > 16 on initial evaluation. Baseline and follow-up SPECT studies with a mean interval of 12 mo were performed on these patients. We used the adjusted rCBF images in the relative flow distribution (normalization of global cerebral blood flow for each patient to 50 mL/100 g/min with proportional scaling) to compare these groups through statistical parametric mapping.

RESULTS

In the follow-up study, the adjusted rCBF was significantly preserved in the right and left anterior cingulate gyri, right middle temporal gyrus, right inferior parietal lobules, and prefrontal cortex of donepezil-treated AD patients, compared with placebo-treated AD patients.

CONCLUSION

Treatment with donepezil for 1 y appears to reduce the decline in rCBF, suggesting preservation of functional brain activity.