MR measurement of visceral fat: assessment of metabolic syndrome.

One diagnostic criterion for metabolic syndrome is obesity from the accumulation of visceral fat; others include abdominal circumference and area of visceral fat as measured by computed tomography (CT) at the umbilical level. We evaluated visceral fat using frequency-selective excitation magnetic resonance (MR) imaging SPAIR (spectral attenuation with inversion recovery) water suppression THRIVE (3D T1-high resolution isotropic volume examination). Fifty of 70 slices with 2-mm interval were used to render and measure volume of visceral fat ranging within 10 cm of the umbilicus; the area of visceral fat at the umbilical level was also measured. Imaging was completed using breath hold within 14 s. Image processing was easier than using CT.     

Living domino liver transplantation in an adult with congenital absence of portal vein.

Congenital absence of the portal vein (CAPV) is a rare malformation of the splanchnic venous system. Although CAPV is usually detected in the pediatric age group, our patient was a 35-year-old woman. She had been diagnosed with CAPV in 1996 when she was 27 years old. In 1998, she was placed on hemodialysis due to chronic renal failure. After several episodes of encephalopathy in 2002, liver transplantation (LT) was recommended to her and her family. Since there was no suitable living donor candidate, she was put on the waiting list for a deceased donor liver transplant in Japan. In 2004, her ammonia level increased to around 300 microg/dl, and she went into a coma lasting for three days. After recovering from this event, she underwent a living domino transplantation using a whole liver donated by a familial amyloid polyneuropathy (FAP) patient. Her portal vein, which had drained directly into the inferior vena cava (IVC), was transected together with a cuff of the IVC wall and anastomosed to the graft liver portal vein in an end-to-end fashion. In conclusion, liver transplantation proved to be a safe and effective way to save this patient and improve her quality of life.     

Flunarizine induces a transient loss of tyrosine hydroxylase immunoreactivity in nigrostriatal neurons

Neurotoxic effects of flunarizine (Fz), a selective calcium channel blocker, on the nigrostriatal dopamine system was investigated. Systemic injections of Fz to mice resulted in a transient loss of tyrosine hydroxylase (TH) immunoreactive nigrostriatal neurons without cell loss. TH immunoreactivity in these neurons was greatly reduced as rapidly as one day after drug administration (regardless of dosage used) and thereafter recovered in both dose- and time-dependent manners. Such a novel neurotoxic action of Fz may constitute a morphological substrate for reversible drug-induced parkinsonian signs described in recent clinical case reports.     

Quantitative analysis of sodium fast and slow component in in vivo human brain tissue using MR Na image]

In vivo sodium concentrations in the normal brain tissue and a tumorous tissue were analyzed using MR Na image. The nuclear magnetic resonance enabled us to divide the signal from sodium in the living tissue into 2 parts based on the differences of T2 value. Those are fast component having the T2 value of less than 5 msec and slow component of 15-40 msec. We investigated the effect of macromolecules on T2 value of sodium image using polyvinyl alcohol (PVA) powder. MR Na image was taken with the parameters of TR/TD, 110 ms/1.9 ms (FID image) and TR/TE, 110 ms/20 ms (SE image). Saline solution showed high intensity on both FID image and SE image. Saline solution added PVA (PVA phantom) also showed high intensity on FID image, whereas the signal intensity of PVA phantom in SE image extinguished. To know the relation between the signal intensity and sodium concentration, sodium concentration--signal intensity curve was obtained using phantoms with various sodium concentrations (0.05-1.0%). This curve showed a direct proportion between sodium concentration and signal intensity on Na image. We measured further the sodium concentrations of the human brain tissue. Sodium phantoms were arranged around the heads and the MR Na images of the normal brains from 3 volunteers and a patient with a brain tumor (meningioma) were taken. The sodium concentrations of occipital lobe, basal ganglia and the tumorous tissue were calculated using the sodium concentration--signal intensity curve obtained from the phantoms arranged around the heads.(ABSTRACT TRUNCATED AT 250 WORDS)     

Surface modification of titanium by etching in concentrated sulfuric acid

OBJECTIVE: The purpose of this study was to characterize the etching behavior of titanium in concentrated sulfuric acid and discuss its application on surface modification of titanium for biological use. METHODS: Commercially pure titanium (cpTi) plate was etched in 48% H2SO4 at RT -90 degrees C for 0.25-8 h. The weight loss was derived from the weight differences before and after etching. The surfaces after etching were characterized by surface roughness, X-ray diffractometry, and scannning electron spectroscopy. The apparent activation energy of the dissolution of cpTi into acid was derived from an Arrhenius plot of the rate of weight loss versus the acid temperature. RESULTS: The surface roughness of cpTi increased with the acid temperature and etching time. The surface roughness was strongly related to the weight loss. The weight loss increased drastically with the acid temperature after an initial period, which shortened with increasing acid temperature. The apparent activation energy for the dissolution of cpTi in H2SO4 was derived as 67.8 kJ/mol. SIGNIFICANCE: This study indicates that etching with concentrated sulfuric acid is an effective way to modify the surface of titanium for biological applications.     

A clinical study of cerebral perfusion during pulsatile and nonpulsatile cardiopulmonary bypass

The purpose of this study was to determine the effect of pulsatile flow on cerebral perfusion under cardiopulmonary bypass (CPB). Twenty-three patients who underwent cardiac operations were divided into two comparable groups: Group A (N = 11) had standard nonpulsatile flow, while in Group B (N = 12), a pulsatile pump was used. The blood flow of left common carotid artery and radial arterial pressure were continuously monitored during cardiac operation in both groups and cerebral vascular resistance was calculated. In Group B, the perfusion pressure of left common carotid artery was monitored and compared with that of radial artery. Arterial and internal jugular venous blood were sampled and the difference of cerebral A.V O2 contents and cerebral oxygen consumption was calculated. Cerebral vascular resistance in Group B (54.0 +/- 11.2% of the value of before-CPB) significantly decreased compared to that in Group A (72.2 +/- 11%) at the end of CPB (p less than 0.05). Pulse pressure following pulsatile CPB flow was 15.1 +/- 5.8 mmHg monitored in radial artery and it reduced to 8.5 +/- 5 mmHg in left common carotid artery. Although there was no significant difference in cerebral oxygen consumption of both groups during and just after CPB, the difference of cerebral A-V O2 contents of Group B was greater than Group A just after CPB. These data suggest that pulsatile flow may minimize the cerebral microcirculatory shunt during CPB, resulting from the reduction of cerebral vascular resistance.