Insular Amyloid in a Case of Type HI Glycogenosis with a Special Reference to the Origin of Amyloid Fibrils

Amyloid depositions of pancreatic islets were investigated with electron microscopy in a case of type III glycogenosis.

Beta cells adjoining small amyloid depositions were shown to have cytoplasmic invaginations where closely packed amyloid fibrils were disclosed regularly orientated amyloid bundles. In the cytoplasm of the beta cells, some membrane-bounded vesicles contained amyloid fibrils and a few beta granules directly transformed into the fibrils within the vesicles.

These findings indicate that, at least in this case, the beta cells play a crucial role in the formation of insular amyloid.     

Hypothermia attenuates apoptosis and protects contact between myelin basic protein‐expressing oligodendroglial‐lineage cells and neurons against hypoxia–Ischemia

Periventricular leukomalacia (PVL) is a major form of brain injury among preterm infants, which is characterized by extensive loss and dysfunction of premyelinating oligodendrocytes (pre‐OLs) induced by hypoxia–ischemia (HI). Therapeutic hypothermia, which is a standard treatment for term infants with HI encephalopathy, is not indicated for preterm infants because its safety and effect have not been established. Here we investigate the effectiveness and mechanism of hypothermia for the inhibition of pre‐OLs damage in PVL. For in vivo studies, 6‐day‐old rats underwent left carotid artery ligation, followed by exposure to 6% oxygen for 1 hr under hypothermic or normothermic conditions. The loss of myelin basic protein (MBP) was inhibited by hypothermia. For in vitro studies, primary pre‐OLs cultures were subjected to oxygen–glucose deprivation (OGD) under normothermic or hypothermic conditions, and dorsal root ganglion neurons were subsequently added. Hypothermia inhibited apoptosis of pre‐OLs, and, despite specific downregulation of 21.5‐ and 17‐kDa MBP mRNA expression during hypothermia, recovery of the expression after OGD was superior compared with normothermia. OGD caused disarrangement of MBP distribution, decreased the levels of phosphorylated 21.5‐kDa MBP, and disturbed the capacity to contact with neurons, all of which were restored by hypothermia. Pharmacological inhibition of ERK1/2 phosphorylation with U0126 during and after OGD significantly reduced the protective effects of hypothermia on apoptosis and myelination, respectively. These data suggest that phosphorylated exon 2‐containing (21.5‐ and possibly 17‐kDa) MBP isoforms may play critical roles in myelination and that hypothermia attenuates apoptosis and preserves the contact between OLs and neurons via ERK1/2 phosphorylation. © 2014 Wiley Periodicals, Inc.     

Comparison of short- and long-term outcomes after early versus late liver retransplantation: a single-center experience

Background

As the survival of patients after liver transplantation (LT) improves, the requirement of liver retransplantation (reLT) for late graft failure has grown. Although some have reported that the short-term outcome of late reLT was comparable with that of early reLT, it remains unknown whether long-term survival of late reLT is inferior to that of early reLT patients.

Materials and methods

We reviewed early (<6 mo after primary LT) and late (≥6 mo after primary LT) reLT cases performed between January 2000 and December 2010.

Results

Sixteen early and 32 late reLT cases were analyzed. There was no significant difference regarding the number of units of red blood cells transfused during the transplantation between the groups, whereas operative time was significantly longer in the late reLT cases. Graft loss within 3 mo after early and late reLT was 18.6% and 15.6%, respectively. Patient and graft survival rates after 1, 3, 5, and 10 y in the late reLT group were 80.6%, 73.3%, 73.3%, and 67.7% and 80.7%, 69.1%, 63.3%, and 54.3%, respectively, whereas those in the early reLT group were 75.0%, 75.0%, 64.3%, and 64.3% and 81.3%, 75.0%, 64.3%, and 32.1%, respectively. There was no significant difference in patient or graft survival rates between the groups (P = 0.91 and 0.91, respectively).

Conclusions

Acceptable short- and long-term survival were provided in early and late reLT. The time between the primary LT and reLT does not seem to play significant role in the prognosis of reLT in the long term.     

Combination therapy with intra‐articular injection of mesenchymal stem cells and articulated joint distraction for repair of a chronic osteochondral defect in the rabbit

The present study investigated intra‐articular injection of bone‐marrow‐derived mesenchymal stem cells (MSCs) combined with articulated joint distraction as treatment for osteochondral defects. Large osteochondral defects were created in the weight‐bearing area of the medial femoral condyle in rabbit knees. Four weeks after defect creation, rabbits were divided into six groups: control group, MSC group, distraction group, distraction + MSC group, temporary distraction group, and temporary distraction + MSC group. Groups with MSC received intra‐articular injection of MSCs. Groups with distraction underwent articulated distraction arthroplasty. Groups with temporary distraction discontinued the distraction after 4 weeks. The rabbits were euthanized at 4, 8, and 12 weeks after treatment except temporary distraction groups which were euthanized at only 12 weeks. Histological scores in the distraction + MSC group were significantly better than in the control, MSC group or distraction group at 4 and 8 weeks, but showed no further improvement. At 12 weeks, the temporary distraction + MSC group showed the best results, demonstrating hyaline cartilage repair with regeneration of the osteochondral junction. In conclusion, joint distraction with intra‐articular injection of MSCs promotes early cartilage repair, and compressive loading of the repair tissue after temporary distraction stimulates articular cartilage regeneration. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1466–1473, 2015.     

Multiparametric voxel-based analyses of standardized uptake values and apparent diffusion coefficients of soft-tissue tumours with a positron emission tomography/magnetic resonance system: Preliminary results

Objectives

To investigate the usefulness of voxel-based analysis of standardized uptake values (SUVs) and apparent diffusion coefficients (ADCs) for evaluating soft-tissue tumour malignancy with a PET/MR system.

Methods

Thirty-five subjects with either ten low/intermediate-grade tumours or 25 high-grade tumours were prospectively enrolled. Zoomed diffusion-weighted and fluorodeoxyglucose (¹⁸FDG)-PET images were acquired along with fat-suppressed T2-weighted images (FST2WIs). Regions of interest (ROIs) were drawn on FST2WIs including the tumour in all slices. ROIs were pasted onto PET and ADC-maps to measure SUVs and ADCs within tumour ROIs. Tumour volume, SUVmax, ADCminimum, the heterogeneity and the correlation coefficients of SUV and ADC were recorded. The parameters of high- and low/intermediate-grade groups were compared, and receiver operating characteristic (ROC) analysis was also performed.

Results

The mean correlation coefficient for SUV and ADC in high-grade sarcomas was lower than that of low/intermediate-grade tumours (?0.41?±?0.25 vs. ?0.08?±?0.34, P?<?0.01). Other parameters did not differ significantly. ROC analysis demonstrated that correlation coefficient showed the best diagnostic performance for differentiating the two groups (AUC 0.79, sensitivity 96.0%, specificity 60%, accuracy 85.7%).

Conclusions

SUV and ADC determined via PET/MR may be useful for differentiating between high-grade and low/intermediate-grade soft tissue tumours.

Key Points

? PET/MR allows voxel-based comparison of SUVs and ADCs in soft-tissue tumours. ? A comprehensive assessment of internal heterogeneity was performed with scatter plots. ? SUVmax or ADCminimum could not differentiate high-grade sarcoma from low/intermediate-grade tumours. ? Only the correlation coefficient between SUV and ADC differentiated the two groups. ? The correlation coefficient showed the best diagnostic performance by ROC analysis.

     

Utility of the new Japanese severity score and indications for special therapies in acute pancreatitis

Background  The Japanese severity score (JSS) for acute pancreatitis was revised in 2008. As special therapies for severe acute pancreatitis (SAP), continuous regional arterial infusion of protease inhibitor and antibiotics (CRAI) and enteral nutrition (EN) are now utilized in Japan. We investigated the usefulness of the new JSS and the indications for CRAI and EN based on the new JSS. Methods  We assessed the new JSS in 138 patients with SAP according to the previous Japanese criteria. Usefulness of the new JSS for the prediction of mortality rates was compared with conventional scoring systems by receiver-operator characteristic curve analysis. We analyzed the relationship between the new JSS and prognosis in patients with and without CRAI and EN, respectively. Results  Forty-five patients (33%) were assessed as having mild acute pancreatitis, and 93 patients (67%) were assessed as having SAP. Their mortality rates were 7 and 40%, respectively. The area under the curve for the prediction of mortality rates with the new JSS was 0.822 and was the highest among conventional scoring systems. In patients with new JSS ≥ 6, the mortality rate was lower in patients with CRAI than in patients without CRAI (P = 0.129). In patients with new JSS ≥ 4, the mortality rate was lower in patients with EN than in patients without EN (P = 0.016). Conclusions  The new JSS is useful and easier to use for the prediction of prognosis compared to the conventional scoring systems. EN was effective in reducing the mortality rate in patients with a new JSS ≥ 4.     

Tissue plasminogen activator in the treatment of vitreoretinal diseases

Tissue plasminogen activator (tPA) is a thrombolytic agent that activates plasminogen into plasmin almost exclusively in the presence of fibrin. Intraocular injection of tPA has been proposed for the treatment of vitreoretinal diseases, such as vitreous hemorrhage, postvitrectomy fibrin formation, submacular hemorrhage, retinal vascular occlusive disorders, suprachoroidal hemorrhage and endophthalmitis. Currently, intraocular tPA is only used in the treatment of postvitrectomy fibrin formation and submacular hemorrhage. For other indications, tPA has not been shown to be safe or effective. This article reviews the use of tPA in the treatment of vitreoretinal disorders.     

Effects of metabolic fragments of [Arg]-vasopressin on nerve growth in cultured hippocampal neurons

The effects of metabolic fragments of [Arg⁸]-vasopressin (AVP), [pGlu⁴, Cyt⁶]AVP (AVP_4–9), and desglycinamide-[pGlu⁴, Cyt⁶]AVP (AVP_4–8) on the growth of hippocampal neurons in culture were investigated in comparison with those of AVP. AVP_4–9 caused a significant increase in filopodial length following 96 h of exposure at concentrations higher than 300 nM. AVP_4–9 was more potent than AVP. AVP_4–8 also induced an increase in filopodial length, but this effect was less than that of AVP. The selective V₁ agonist [Phe², Ile³, Orn⁸]-vasopressin caused a significant increase in filopodial length, whereas the selective V₂ agonist [deamino-Cys¹, -Arg⁸]-vasopressin showed no such effect. OPC-21268, a vasopressin V₁ antagonist, blocked AVP and AVP fragment-induced increases in filopodial length. However, the V₂ antagonist OPC-31260 showed no such effect. A23187, a representative Ca ionophore, also increased filopodial length, and the A23187-induced increase in filopodial length was potentiated by AVP and AVP fragments. These results indicated that AVP_4–9 and AVP_4–8 increased filopodial length in cultured hippocampal neurons by activating V₁ receptors. Both phenomena induced by AVP_4–9 and AVP_4–8 were associated with intracellular calcium mobilization.     

Mechanism of the inhibitory effect of histamine on amygdaloid-kindled seizures in rats

PURPOSE: The mechanism of the inhibitory effect of histamine on amygdaloid-kindled seizures was investigated in rats. METHODS: Under pentobarbital anesthesia, rats were fixed to a stereotaxic apparatus, and bipolar electrodes were implanted into the right amygdala. A guide cannula made of stainless steel tubing was implanted into the right lateral ventricle. Electrodes were connected to a miniature receptacle, which was embedded in the skull with dental cement. EEG was recorded with an electroencephalograph; stimulation of the amygdala was applied bipolarly every day by a constant-current stimulator and continued until a generalized convulsion was obtained. RESULTS: Intracerebroventricular (i.c.v.) injection of histamine at doses of 2-10 microg resulted in a dose-related inhibition of amygdaloid-kindled seizures. I.c.v. injection of calcium chloride at doses of 10-50 microg and A23187 at doses of 2-10 microg also caused dose-dependent inhibition of amygdaloid-kindled seizures. Calcium chloride at a dose of 10 microg, which showed no significant effect on amygdaloid-kindled seizures when used alone, significantly potentiated the effect of histamine. Similar findings were observed with A23187 at a dose of 2 microg. In addition, EGTA and EGTA/AM antagonized the inhibition of kindled seizures induced by histamine. Moreover, the inhibition of kindled seizures induced by histamine was antagonized by KN62. However, calphostin C did not antagonize the inhibitory effect of histamine. CONCLUSIONS: These results indicated that histamine-induced inhibition of amygdaloid-kindled seizures may be closely associated with a calcium calmodulin-dependent protein kinase II activation pathway.