Clinical evaluation of the diagnosis of neuronal reversibility with acute cerebral infarction using ADC by diffusion weighted echo planar imaging

The possibility of diagnosing neuronal reversibility with acute cerebral infarction was studied using ADC measured by diffusion weighted imaging (DWI). The subjects were eleven patients who underwent DWI within 24 hours of onset. The area of abnormal signal on DWI during the acute stage was visually compared with that on T2-WI in the subacute phase. ADC was calculated in the two different abnormal areas on DWI, which were differentiated by the presence or absence of abnormality on T2-WI in the subacute phase. The abnormal signals of three cases showed an obviously narrowed area on DWI in the acute phase compared with the abnormality on T2-WI in the sub-acute phase. ADCs of the ischemic areas in DWI abnormalities that showed no abnormality on subacute T2-WI were slightly higher than those of the infarct areas with remaining abnormal signals on T2-WI. However, no statistically significant difference was found between these two regions, because there were large variations within each pixel. We considered that the diagnosis of neuronal reversibility in acute cerebral infarction was difficult using ADC values only and that other parameters such as perfusion or blood volume will be necessary to improve diagnostic quality prior to determining therapy.     

LIPID EMULSIONS OF PALMITOYLRHIZOXIN: EFFECTS OF PARTICLE SIZE ON BLOOD DISPOSITIONS OF EMULSION LIPID AND INCORPORATED COMPOUND IN RATS

Emulsion formulations of various particle sizes for the highly lipophilic antitumour agent, RS-1541 (13-O-palmitoylrhizoxin), were prepared using dioctanoyldecanoyl-glycerol (ODO) as lipids and polyoxyethylene-(60)-hydrogenated castor oil (HCO-60) as a surfactant. These emulsions were evaluated as injectable drug carriers and compared with a colloidal solution. Both in vitro and in vivo after i.v. administration, RS-1541 was distributed into lipoproteins from the colloidal solution. When applied as emulsions of various particle sizes (124–419 nm) in vitro, RS-1541 was retained and stabilized within the emulsions. In the in vivo study, however, retention of RS-1541 in the emulsions after i.v. injection depended on their size. The small-particle emulsions (94–112 nm) resulted in long retention, and the large-particle emulsions (415–474 nm) led to short retention. Lipolysis rates of emulsion particles by lipoprotein lipase also depended on their size, indicating rapid lipolysis for small-particle emulsions (133 nm). However, the lipolysis was not such an extensive one, showing 10–30% release of capric acid from ODO within 6 h. Blood dispositions of capric acids approximately paralleled those of RS-1541 after i.v. injection of various particle size emulsions (130–368 nm) to rats, although relatively rapid eliminations of capric acids compared with RS-1541 were observed for the small-particle size emulsions (130 nm). These results suggest that when injected as emulsion formulations, the highly lipophilic antitumour agent, RS-1541, has behaviour similar to that of the emulsion particles in the body, which is dependent on the size of the latter. Thus, by properly selecting the particle size, lipid emulsions consisting of ODO and HCO-60 are expected to be effective and useful DDS carriers for RS-1541.     

Morphological development of the rat fetal pancreas.

Rat fetal pancreata of days 12 to 19 of gestation and those of neonates were examined with light and electron microscopes. The pancreas arose from the primitive epithelium of the foregut as two primordia (dorsal and ventral pancreatic primordia) of epithelial cell nests surrounded with abundant fetal mesenchymal tissue between days 11 and 12. Primitive pancreatic islets, which mainly consisted of the endocrine cells with A cell type secretory granules, also appeared in the primordia at this age. The epithelial cell nests elongated gradually and had a branching cord-like arrangement. Two pancreatic primordia fused together on day 15, and an apparent ductular structure was observed on days 15 to 17. An acinar configuration of exocrine cells with zymogen granules gradually formed between days 17, 18 and 19. After birth, the volume of pancreatic parenchyma markedly increased and that of mesenchymal tissue prominently decreased. Ultrastructurally, the pancreatic primordia in the early stage showed immature epithelial features with the surrounding basement membrane and inconspicuous intercellular junctions. This might imply a plasticity in cellular differentiation of protodifferentiated pancreatic epithelial cells toward a ductular structure of immature exocrine pancreas which appeared later. In addition to the basement membrane, abundant fetal mesenchymal tissue was considered to play a possible role in the early morphogenesis in pancreatic development.     

Three-dimensional observation of the rat endocrine pancreas by a scanning electron microscope

A three-dimensional observation was performed on chemically digested rat pancreata and vascular corrosion casts of it with a scanning electron microscope. The Langerhans islets were sporadically situated in the exocrine tissue and were surrounded by the fibrous capsule, which was so tough that it could not be chemically digested easily. This capsule was considered to play different roles in the collection of the endocrine cells in a functional unit, in the prevention of secreted hormones spreading into the adjacent exocrine and stromal tissue, in the support of the microvascular structure, and in the protection for the islet cells from the pancreatic enzymes, which are leaking into the stromal spaces physiologically. The microvascular structure of the islet, disclosed by the corrosion vascular casts, showed afferent vessels branching into the capillaries at the periphery of the islet and entering the core of it by a twisted course. These findings were considered to be related to the islet cell distribution, that is, A and D cells are at the periphery of the islet and B cells at the center of it. This might support the existence of a hormonal regulating mechanism among endocrine cells. In addition, the efferent vessels from the islet that communicate to the vascular network of the exocrine tissue might suggest that the endocrine system also regulates the exocrine function in a circulatory dynamic state.     

A case of facioscapulohumeral muscular dystrophy complicated with complete A-V block

Myocardial involvement and serious electrocardiographic abnormalities are rare in patients with facioscapulohumeral (FSH) muscular dystrophy. We reported a case of FSH muscular dystrophy complicated with complete A-V block. The case was that of a 48 year-old male with the complaints of exertional dyspnea. His chest X-ray showed cardiomegaly, and the electrocardiogram recorded on admission showed complete A-V block. On the His bundle electrogram, complete A-H block and prolongation of H-V intervals were noted. Therefore, a permanent pacemaker was implanted, and he has been doing well for over 10 years after implantation. Although it is well known that serious electrocardiographic abnormalities are not infrequently associated with Duchenne's progressive muscular dystrophy (DMD), there are few reports about pacing therapy for patients with muscular dystrophy. Because the daily activity of patients with rapidly progressive type of muscular dystrophy such as DMD is at a very low level, they do not require pacing therapy. Whereas in patients with the FSH type of muscular dystrophy, which is a slowly progressive type, their daily activity is maintained at a high level. Therefore, pacing therapy should be recommended if the FSH type of muscular dystrophy is accompanied with serious bradyarrhythmias.     

Successful repair of a large pseudoaneurysm of the left ventricle late after mitral valve replacement due to rupture of the papillary muscle following acute myocardial infarction.

We present a rare case demonstrating a large pseudoaneurysm of the left ventricle late after mitral valve replacement due to rupture of the papillary muscle following acute myocardial infarction. A 52-year-old man, who had undergone mitral valve replacement 7 months previously, presented with severe congestive heart failure. Echocardiography and computed tomography of the chest demonstrated a large pseudoaneurysm of the left ventricle. The patch repair of the orifice of the pseudoaneurysm was successfully performed.     

Expression of a member of tumor necrosis factor receptor superfamily,TROY, in the developing mouse brain

TROY is a recently identified member of the tumor necrosis factor (TNF) receptor superfamily. We investigated the expression pattern of TROY mRNA in the developing central nervous system by the in situ hybridization technique. TROY mRNA was strongly expressed in the ventricular zone and the subventricular zone, which contain neuronal and glial precursors during mouse embryogenesis. Its spatial and temporal expression patterns suggest that TROY plays some important roles in neurogenesis of embryonic stages.     

Oncocytic schneiderian papilloma confined to the sphenoid sinus detected by FDG-PET

We report a 55-year-old man with oncocytic schneiderian papilloma confined to the sphenoid sinus, which was initially detected by positron emission tomography with 18F-fluorodeoxyglucose (FDG-PET) at a very early stage. Based on CT and MRI findings, we suspected that the tumor was most likely benign; however, positive uptake in FDG-PET suggested malignancy. The patient underwent endoscopic resection of the tumor, and the histopathological diagnosis turned out to be oncocytic schneiderian papilloma. FDG-PET is thought to be a powerful tool to search for malignant lesions, but the present case demonstrates the fallibility of this technique. This should be taken into consideration when interpreting FDG-PET images.     

Abnormal Ca2+ release from cardiac sarcoplasmic reticulum in tachycardia-induced heart failure

OBJECTIVE: In heart failure, little information is available as to the Ca2+ release function of sarcoplasmic reticulum (SR), which plays a major role in cardiac contractile function. Here, we assessed the rapid kinetics of drug-induced Ca2+ release from cardiac SR in combination with a measurement of ryanodine binding in heart failure. METHODS: The SR vesicles were isolated from dog left ventricular (LV) muscles (normal (N), n = 10; pacing induced heart failure (HF), n = 10). The time course of SR Ca2+ release was continuously monitored by a stopped-flow apparatus using arsenazoIII as a Ca2+ indicator, and Ca2+ uptake and [3H]ryanodine binding assays were done using a filtration method. RESULTS: The amount of Ca2+ uptake was reduced in HF to 55% of N (P < 0.05). Even the more marked and earlier appeared decrease was seen in the rate constant and the initial rate of polylysine (PL; a specific release trigger)-induced Ca2+ release (P < 0.05). However, the PL concentration dependency of the initial rate shifted towards lower concentrations of PL in HF than in N ([PL] at half maximum stimulation = 0.13 vs. 0.35 microM). The [3H]ryanodine binding assay revealed a lower Bmax (pmol/mg) in HF than in N (0.91 +/- 0.19 vs. 2.64 +/- 0.59, P < 0.05), but no difference in Kd (nM) (0.95 +/- 0.29 vs. 0.90 +/- 0.11, P = n.s.). The [PL] dependency on the enhancement of [3H]ryanodine binding again showed a shift towards lower [PL] in HF than in N. CONCLUSIONS: In pacing-induced heart failure, the Ca2+ releasing function of SR is disturbed, which may result in an intra-cellular Ca2+ transient that was slowed down.