Light- and electron-microscopic studies of transplanted human dystrophic muscles to nude mice

Light-microscopic study of muscles from 8 patients with Duchenne muscular dystrophy (DMD) and 9 control cases transplanted into nude mice showed the formation of cross-striations and peripheral nuclei in regenerating muscle fibers of both DMD and control grafts up to 4 weeks. Quantitative study of the diameter of myotubes and myoblasts in grafted muscles showed that the group mean diameters of DMD myotubes and myoblasts were 13.4 ± 0.8 (SE) μm, 15.6 ± 0.7 μm, 17.1 ± 0.9 μm and 16.2 ± 1.0 μm after 1, 2, 3 and 4 weeks of transplantation, respectively, whereas those of control myotubes and myoblasts were 14.9 ± 0.6 (SE) μm, 19.9 ± 0.5 μm, 21.3 ± 0.7 μm and 20.7 ± 0.7 μm after the same intervals. The group mean diameters of the DMD regenerating myotubes and myoblasts were significantly smaller than those of control myotubes and myoblasts at 2 (P <0.001), 3 (P <0.005) and 4 (P <0.005) weeks after transplantation.Electron-microscopic findings of DMD muscle grafts were morphologically similar to those seen in control muscle grafts at all stages of this experiment.     

Freeze fracture studies of muscle plasma membrane in human muscular dystrophy

Summary Freeze fracture analysis of intramembranous particle density in skeletal muscle plasma membrane from 7 patients with Duchenne muscular dystrophy (DMD), 5 patients with facioscapulohumeral muscular dystrophy (FSH) and 5 patients with myotonic dystrophy (MyD) were carried out. Marked deplction of intramembranous particles including orthogonal arrays were significantly decreased in FSH. No abnormalities were noted in MyD.This work was supported by a Research Center Grant from the Muscular Dystrophy Association of America and by grants NS-08075, NS-14471 and 5 M01 RR00040 from the U.S. Public Health Service     

Effective gene therapy of biliary tract cancers by a conditionally replicative adenovirus expressing uracil phosphoribosyltransferase: significance of timing of 5-fluorouracil administration

In order to enhance the efficacy of conditionally replicating adenoviruses (CRAd) in the treatment of cancers of the biliary tract, we studied the efficacy in vitro and in vivo of AxE1CAUP, a CRAd vector that carries a gene for uracil phosphoribosyltransferase (UPRT), which converts 5-fluorouracil (5-FU) directly to 5-fluorouridine monophosphate and greatly enhances the cytotoxicity of 5-FU. AxE1CAUP replicated and induced an increased UPRT expression in biliary cancer cells more efficiently than AxCAUP, a nonreplicative adenovirus carrying the UPRT gene. Whereas AxCAUP and AxE1AdB, a CRAd without the UPRT gene, modestly increased the sensitivity of BC cells to 5-FU, AxE1CAUP markedly increased the sensitivity, especially when the timing of 5-FU administration was appropriately chosen. AxE1CAUP replicated much less efficiently in normal WI-38 fibroblasts without any change in the sensitivity to 5-FU. In nude mice with s.c. biliary cancer xenografts, i.t. AxE1CAUP/5-FU therapy inhibited tumor growth significantly more strongly than AxCAUP/5-FU or AxE1AdB/5-FU therapy. Furthermore, in mice with peritoneally disseminated biliary cancer, i.p. AxE1CAUP efficiently proliferated in the tumors, decreased the tumor burden, and prolonged the survival of the mice when 5-FU was started 10 or 15 days after the vector inoculation, whereas earlier initiation of 5-FU resulted in early eradication of the vector and no survival benefit. The present study shows that the CRAd expressing UPRT was a more potent sensitizer of biliary cancer to 5-FU, than was a nonreplicative UPRT-encoding vector or a CRAd without UPRT gene, even at a lower dose of the vector, and that timing of 5-FU administration was a key factor to maximize the efficacy. This gene therapy with appropriately timed administration of 5-FU should be useful in overcoming the resistance of biliary cancers to 5-FU.     

Metastatic brain tumors with simultaneous multiple cerebral hemorrhages: a case report

We encountered a case of multiple metastatic brain tumors with simultaneous multiple cerebral hemorrhages. A 45-year-old male suffered from sudden left hemiplegia and was admitted to our hospital. CT scans on admission revealed multiple cerebral hemorrhages with surrounding brain edema in the right frontal lobe, left frontal lobe, right occipital lobe and right basal ganglia. On full-body examination, renal cell carcinoma of the left kidney and multiple metastatic tumors in the lung, liver and vertebral body were identified. We continued conservative therapy, but the patient's condition worsened and he died 36 days later. The autopsy findings indicated that all hemorrhages had occurred in the necrotic tissue associated with the metastatic brain tumors. Simultaneous multiple cerebral hemorrhages caused by metastatic brain tumors are very rare, and the differential diagnosis of cerebral hemorrhage due to metastatic brain tumor and hypertensive cerebral hemorrhage is difficult. The present case indicates that metastatic brain tumor should be taken into consideration in cases with simultaneous multiple intracerebral hemorrhages.     

Analyses of restricted diffusion of water molecules using trabecular bone phantom

We have reported that the apparent diffusion coefficient (ADC) was correlated with bone mineral density, but the relation between the restricted diffusion of the water molecules and the trabecular bone structure was unclear. The purpose of our study is to clarify this relationship using two component analyses with an original phantom. With an increase in the interspace area of the simulated trabecular bone, the ADC of the fast component was increased, and the fraction of the fast component was also increased. On the other hand, with an increase in the interspace area of the simulated trabecular bone, the ADC of the slow component was decreased, and the fraction of the slow component was increased. Moreover, the ADC and fraction of the dry vertebral bone agreed with those of the simulated trabecular bone. This result means that our phantoms can reproduce the actual trabecular bone structure, which induces the restricted diffusion. The diffusion of the water molecules was separated into fast and slow components because of the restricted diffusion of the trabecular bone structure. Our original phantom enables analyzing restricted diffusion, and this analytical method obtains more detailed information on trabecular bone structure.     

Chronic Renal Failure as a Possible Risk Factor for Allergic Reaction in Therapeutic Plasma Exchange Using Fresh Frozen Plasma

The incidence of allergic reactions in patients with chronic renal failure during plasma exchange using fresh frozen plasma is not well known. We retrospectively reviewed 62 patients who underwent plasma exchange between January 2013 and May 2018. The most common indication for plasma exchange was desensitization/preconditioning for kidney transplant (61.3%, 38/62). The incidence of allergic reactions was significantly higher in patients with chronic renal failure than patients without (57.1% vs. 25.0%, P = 0.029). Also, the incidence of allergic reactions tended to be higher in peritoneal dialysis patients (75%, 3/4) than in hemodialysis (58.8%, 10/17) and preemptive kidney transplant (58%, 11/19). These results suggested the relationship of chronic renal failure and the incidence of allergic reactions in patients undergoing therapeutic plasma exchange using fresh frozen plasma.     

A sodium channel blocker, pilsicainide, produces atrial post-repolarization refractoriness through the reduction of sodium channel availability

Atrial fibrillation (AF) is the most common tachyarrhythmia. Shortening of atrial action potential duration (APD) and effective refractory period (ERP) is one of the crucial factors in the occurrence and maintenance of AF. ERP is usually shorter than APD, but ERP can be prolonged beyond action potential repolarization in some situations. It is termed as post-repolarization refractoriness (PRR) that is thought to be one of main anti-arrhythmic mechanisms of class I sodium channel blockers (SCBs). Most of anti-arrhythmic agents, including SCBs, have multi-channel blocking effects. It is unknown whether atrial PRR with SCBs is associated with the reduction of sodium channel availability. We therefore explored the relationship between the reduction of sodium channel availability with a pure SCB (pilsicainide or tetrodotoxin) and atrial PRR using the left atrial appendage from male guinea pigs (each group, n = 3~10). Employing a standard microelectrode technique, we evaluated APD measured at 90% repolarization (APD(90)) and the sodium channel availability, judged from the maximal rate of rise of action potential (Vmax). At a 500-msec basic cycle length (BCL), pilsicainide prolonged atrial ERP assessed by a single extra-stimulus in response to the decrement of the Vmax in a dose-dependent manner without affecting APD(90). Furthermore, pilsicainide increased the ERP and decreased the Vmax in a rate-dependent manner without APD(90) prolongation at a shorter BCL (200 msec). Importantly, tetrodotoxin reproduced the effects of pilsicainide on atrial ERP, APD(90), and Vmax. These results indicate that SCBs produce atrial PRR through the reduction of sodium channel availability.     

Right pleural effusion in Fitz-Hugh-Curtis syndrome

Right pleural effusion was diagnosed in a 36-year-old woman with right upper quadrant pain and fever. Enhanced pelvic computed tomography performed because of irregular genital bleeding revealed the pelvic inflammatory disease. Upon further questioning, the patient confirmed that she had recently undergone therapy for Chlamydia trachomatis infection. Therefore she was given an injection of tetracycline because we suspected Fitz-Hugh-Curtis syndrome (FHCS), a pelvic inflammatory disease characterized by perihepatitis associated with chlamydial infection. A remarkable clinical response to antibiotics was noted. The right upper quadrant pain was due to perihepatitis, and the final diagnosis was FHCS. Right pleural effusion may be caused by inflammation of the diaphragm associated with perihepatitis. Once chlamydial infection reaches the subphrenic liver, conditions in the closed space between the liver and diaphragm due to inflammatory adhesion may be conductive to chlamydial proliferation. The possibility of FHCS should be considered in patients and carefully distinguished from other abdominal diseases.