Clinico-radiological spectrum of reversible splenial lesions in children

Recently, many cases of children presenting reversible splenial lesions during febrile illness (RESLEF) have been reported; however, their overall clinico-radiological features are unclear.     

Disruption of actin‐binding domain‐containing Dystonin protein causes dystonia musculorum in mice

The Dystonin gene (Dst) is responsible for dystonia musculorum (dt), an inherited mouse model of hereditary neuropathy accompanied by progressive motor symptoms such as dystonia and cerebellar ataxia. Dst‐a isoforms, which contain actin‐binding domains, are predominantly expressed in the nervous system. Although sensory neuron degeneration in the peripheral nervous system during the early postnatal stage is a well‐recognised phenotype in dt, the histological characteristics and neuronal circuits in the central nervous system responsible for motor symptoms remain unclear. To analyse the causative neuronal networks and roles of Dst isoforms, we generated novel multipurpose Dst gene trap mice, in which actin‐binding domain‐containing isoforms are disrupted. Homozygous mice showed typical dt phenotypes with sensory degeneration and progressive motor symptoms. The gene trap allele (Dst^Gt) encodes a mutant Dystonin‐LacZ fusion protein, which is detectable by X‐gal (5‐bromo‐4‐chloro‐3‐indolyl‐β‐D‐galactoside) staining. We observed wide expression of the actin‐binding domain‐containing Dystonin isoforms in the central nervous system (CNS) and peripheral nervous system. This raised the possibility that not only secondary neuronal defects in the CNS subsequent to peripheral sensory degeneration but also cell‐autonomous defects in the CNS contribute to the motor symptoms. Expression analysis of immediate early genes revealed decreased neuronal activity in the cerebellar‐thalamo‐striatal pathway in the homozygous brain, implying the involvement of this pathway in the dt phenotype. These novel Dst^Gt mice showed that a loss‐of‐function mutation in the actin‐binding domain‐containing Dystonin isoforms led to typical dt phenotypes. Furthermore, this novel multipurpose Dst^Gt allele offers a unique tool for analysing the causative neuronal networks involved in the dt phenotype.     

Laparoscope-assisted Hassab's Operation for Esophagogastric Varices After Living Donor Liver Transplantation: A Case Report

This is the first successful report of a laparoscope-assisted Hassab's operation for esophagogastric varices after living donor liver transplantation (LDLT). A 35-year-old man underwent LDLT using a right lobe graft as an aid for primary sclerosing cholangitis (PSC) in 2005. Follow-up endoscopic and computed tomography (CT) examinations showed esophagogastric varices with splenomegaly in 2009 that increased (esophageal varices [EV]: locus superior [Ls], moderator enlarged, beady varices [F2], medium in number and intermediate between localized and circumferential red color signs [RC2]; gastric varices [GV]: extension from the cardiac orifice to the fornix [Lg-cf], moderator enlarged, beady varices [F2], absent red color signs [RC0]). A portal venous flow to the esophagogastric varices through a large left gastric vein was also confirmed. Preoperative Child-Pugh was grade B and score was 9. Because these esophagogastric varices had a high risk of variceal bleeding, we proceeded with a laparoscope-assisted Hassab's operation. Operative time was 464 minutes. Blood loss was 1660 mL. A graft liver biopsy was also performed and recurrence of PSC was confirmed histologically. It was suggested that portal hypertension and esophagogastric varices were caused by recurrence of PSC. Postoperative complications were massive ascites and enteritis. Both of them were treated successfully. This patient was discharged on postoperative day 43. Follow-up endoscopic study showed improvement in the esophagogastric varices (esophageal varices [EV]: locus superior [Ls], no varicose appearance [F0], absent red color signs [RC0], gastric varices [GV]: adjacent to the cardiac orifice [Lg-c], no varicose appearance [F0], absent red color signs [RC0]) at 6 months after the operation. We also confirmed the improvement of esophagogastric varices by serial examinations of CT.     

Role of male pelvic floor muscles and anterior fibromuscular stroma in males on α1‐blocker treatment: A magnetic resonance imaging study

Dynamic motion of the pelvic floor muscles during voiding was analyzed using real‐time magnetic resonance imaging. To evaluate the contraction of the pelvic floor muscles, striated urethral sphincter distance, levator ani muscle thickness and anterior fibromuscular stroma distance were measured. The percent contraction of the striated urethral sphincter from before voiding to just before initiation of voiding was 14% in the normal group and 5% in the voiding dysfunction group. The percent contraction of the anterior fibromuscular stroma from before voiding to just before initiation of voiding was 11% in the normal group and 1% in the voiding dysfunction group; the percent contraction of the muscles was significantly greater in the normal group (P < 0.05). Striated urethral sphincter and anterior fibromuscular stroma contraction at initiation of voiding open the bladder neck and urethra. This plays an important role in the smooth initiation of voiding.     

Kupffer cell function in chronic liver injury and after partial hepatectomy

The reticuloendothelial system (RES) plays an important role in the biological defense system. In the liver, Kupffer cells are the main constituent of the RES, and when their function is impaired postoperative complications may more often occur. By using^99mTc-labeled human serum albumin millimicrospheres (^99mTc-HSA-MM) combined with assessment of single photon emission computed tomography (SPECT), we have attempted to determine the function of Kupffer cells independently of the hepatic blood flow. First, Kupffer cell function in rats with chronic liver injury caused by CCl₄ was studied. The hepatic uptake rate in chronic liver injury was decreased, and a reduced phagocytic activity of the Kupffer cells was noted. The parameter concerning Kupffer cell degradation, the excretion rate (k), was markedly decreased in the early period of chronic liver injury. Changes in Kupffer cell function after 30% and 70% hepatectomy were also studied. After 30% hepatectomy, the excretion rate was decreased on the first postoperative day (POD), and it was increased beyond that found after sham operation on the 3rd POD. In contrast, slower recovery of uptake rate was demonstrated. After 70% hepatectomy, both uptake and excretion rates were markedly reduced, and recovery was prolonged beyond the 5th POD. The hepatic uptake was not parallel with the excretion rate in either experiment. These results suggest that the method that measures the hepatic excretion rate may provide a better assessment of Kupffer cell function than the current uptake measurement with radiolabeled colloid.     

Effects of acute administration of isoproterenol on the systemic and regional blood flow in the dog

The effects of isoproterenol on cardiac output and the blood flow to various parts of the body have been investigated in pentobarbital-anaesthetized dogs, by the microsphere method. Arterial and venous catheterizations were performed for haemodynamic measurements, drug infusions and blood samples. After a stabilization period, control measurements were carried out on the cardiac output, heart rate, blood pressure, expiratory minute volume and blood gases. Radioactive microspheres of 50 μm diameter, labelled with either ⁸⁵Sr or ¹⁴¹Ce, were then injected into the left ventricle. Thereafter the intravenous infusion of isoproterenol (0.5 μg min^?1 kg^?1 was started. Fifteen minutes after initiation of the drug infusion, the same parameters as in the control period were measured and the injection of radioactive microspheres into the left ventricle was repeated. At the end of the experiment, various organs and tissues were removed and weighed and their radioactivity was determined. The fractional distribution of cardiac output and the blood flow to various organs and tissues were calculated by the method after Rudolph &; Heymann (1967). The infusion of isoproterenol resulted in an increase of 57% in cardiac output but changes in regional blood flow varied. The fraction of cardiac output to the myocardium, skeletal muscle and skin were increased, whereas that to the kidney, pancreas and brain decreased. The fraction to the bronchial arteries and splanchnic organs except for the pancreas remained unchanged. The uneven distribution of cardiac output to the various areas may be due mainly to the differences in direct and indirect responses of individual vascular beds to isoproterenol.