Clinical characteristics of fulminant-type autoimmune hepatitis: an analysis of eleven cases

BACKGROUND

Although a few adult cases of fulminant-type autoimmune hepatitis have been reported, their clinical features and prognosis have remained uncertain.

AIM

To assess the clinical features and prognosis of patients with fulminant-type autoimmune hepatitis.

METHODS

Eleven patients (10%) diagnosed with fulminant-type autoimmune hepatitis in accordance with the 1999 criteria of the International Autoimmune Hepatitis Group were analysed.

RESULTS

All 11 patients were female, with a median age of 53 years. Five patients survived without liver transplantation, one received a liver transplantation, and five died without liver transplantation. Nine patients (82%) survived for 2 weeks or more following diagnosis, without liver transplantation. Except for the patient receiving a liver transplantation, serum total bilirubin levels measured during the clinical course were significantly higher in non-survivors than in survivors, although the accompanying serum alanine aminotransferase levels measured for the two groups were similar. Most significantly, serum total bilirubin levels in non-survivors worsened during days 8-15, while levels in survivors improved during the same period.

CONCLUSIONS

The short-term prognosis for patients with fulminant-type autoimmune hepatitis may be good. However, patients whose serum total bilirubin levels worsen during days 8-15 should be considered for liver transplantation.

Computed Tomography Angiography of Carotid Stent. Comparison of Various Self-expandable Stent in a Phantom Model

SUMMARY

We evaluated Computed Tomography Angiography (CTA) of four different self-expandable stents in phantom model. Three stents ware made of nitinol and one was made of cobaltbased alloy. Each stent placed in plastic injector, filled with diluted iodinated contrast material, and placed on a plastic case filled with saline. CTA was performed on a four-detector CT scanner (detector collimation, 0.5mm: helical pitch 3.5). Axial and longitudinal reconstructions of CT imaging were compared with the instent attenuation. Three nitinol stents showed few artifact, and cobalt-based alloy stent was appeared artificial narrowing. In conclusion, CTA is useful for follow-up examination after carotid artery stenting (CAS) as a less invasive evaluation method.

Fast-scanning atomic force microscopy reveals the molecular mechanism of DNA cleavage by ApaI endonuclease

Newly developed fast-scanning atomic force microscopy (AFM) allows the dissection of molecular events such as DNA-enzyme reactions at the single-molecule level. With this novel technology, a model is proposed of the DNA cleavage reaction by a type IIP restriction endonuclease ApaI. Detailed analyses revealed that ApaI bound to DNA as a dimer and slid along DNA in a one-dimensional diffusion manner. When it encountered a specific DNA sequence, the enzyme halted for a moment to digest the DNA. Immediately after digestion, the ApaI dimer separated into two monomers, each of which remained on the DNA end and then dissociated from the DNA end. Thus, fast-scanning AFM is a powerful tool to aid the understanding of protein structures and dynamics in biological reactions at the single-molecule level in sub-seconds.

Elasto-plastic contact analysis of an ultra-high molecular weight polyethylene tibial component based on geometrical measurement from a retrieved knee prosthesis

The wear phenomenon of ultra-high molecular weight polyethylene (UHMWPE) in knee and hip prostheses is one of the major restriction factors on the longevity of these implants. Especially in retrieved knee prostheses with anatomical design, the predominant types of wear on UHMWPE tibial components are delamination and pitting. These fatigue wear patterns of UHMWPE are believed to result from repeated plastic deformation owing to high contact stresses. In this study, the elasto-plastic contact analysis of the UHWMPE tibial insert, based on geometrical measurement for retrieved knee prosthesis, was performed using the finite element method (FEM) to investigate the plastic deformation behaviour in the UHMWPE tibial component. The results suggest that the maximum plastic strain below the surface is closely related to subsurface crack initiation and delamination of the retrieved UHMWPE tibial component. The worn surface whose macroscopic geometrical congruity had been improved due to wear after joint replacement showed lower contact stress at macroscopic level.

Does pravastatin increase chylomicron remnant catabolism in postmenopausal women with type 2 diabetes mellitus?

OBJECTIVE

We investigated the effects of pravastatin on chylomicron remnant catabolism measured with a 13C stable isotope breath test and plasma apolipoprotein (apo) B-48 and remnant-like particle (RLP)-cholesterol in postmenopausal women with type 2 diabetes mellitus.

PATIENTS AND MEASUREMENTS

Nineteen postmenopausal women with type 2 diabetes were randomized to receive 40 mg/day pravastatin or no treatment for 6 weeks followed by a 2-week washout period, and crossed over for a further 6 weeks. Fractional catabolic rate (FCR) of a chylomicron remnant-like emulsion was determined from 13CO2 enrichment in the breath and plasma using isotope-ratio mass spectrometry and multicompartmental modelling. Plasma apo B-48 and RLP-cholesterol concentrations were also measured as static markers of chylomicron remnant metabolism.

RESULTS

Pravastatin significantly reduced plasma concentrations of cholesterol (5.9 +/- 0.3 vs. 4.8 +/- 0.2 mmol/l; P < 0.001), low density lipoprotein (LDL)-cholesterol (3.5 +/- 0.2 vs. 2.6 +/- 0.2 mmol/l; P < 0.001), triglyceride (2.1 +/- 0.3 vs. 1.7 +/- 0.2 mmol/l; P = 0.017), non-high density lipoprotein (HDL)-cholesterol (4.4 +/- 0.3 vs. 3.3 +/- 0.2 mmol/l; P < 0.001), lathosterol/total cholesterol ratio (2.6 +/- 0.2 vs. 2.0 +/- 0.3, P = 0.035), apo B-100 (1.1 +/- 0.1 vs. 0.8 +/- 0.1 g/l; P = 0.001), apo B-48 (4.8 +/- 0.9 vs. 3.3 +/- 0.6 mg/l; P = 0.016), and RLP-cholesterol (31.4 +/- 8.2 vs. 18.6 +/- 4.6 mg/dl; P = 0.024). Pravastatin was also associated with an increase in sitosterol/total cholesterol ratio (2.8 +/- 0.3 vs. 3.1 +/- 0.3, P = 0.029). Chylomicron remnant-like emulsion catabolism was not, however, significantly altered by pravastatin estimated by either breath or plasma clearance measurements.

CONCLUSIONS

In postmenopausal women, pravastatin decreases plasma concentrations of remnant lipoproteins by a mechanism that may relate chiefly to inhibition of remnant production, but this requires further evaluation.

Fructooligosaccharide consumption improves the decreased dentin formation and mandibular defects following gastrectomy in rats

OBJECTIVE

We examined the effects of fructooligosaccharides (FOS) consumption on gastrectomy-evoked osteopenia and disorders of dentin formation in rats.

MATERIALS AND METHODS

Male Sprague-Dawley rats (n = 28, 35-day old) were equally divided into two groups; sham-operated and gastrectomized, and sham-operation or total gastrectomy was performed. Four weeks after each surgery, the rats were divided into two sub-groups (n = 7 each); with or without 7.5% FOS-feeding for 6 weeks. Backscattered electron images of the mandibular sections were taken to calculate trabecular bone area, cortical bone area and total scan area. Thereafter, the dentin formation rate in maxilla were calculated using a fluorescent microscope.

RESULTS

Trabecular bone area and cortical bone area in GX rats were markedly decreased. FOS-feeding significantly counteracted this reduction, but not to the level seen in sham-operated rats. Total scan area in gastrectomized groups was significantly decreased. The dentin formation rate was not statistically different among the groups, except the gastrectomized group.

CONCLUSION

These results suggest that FOS consumption partially restored osteopenia and almost completely restored the reduction in dentin formation following gastrectomy in rats.

Functional MRI Detection of Activation in the Primary Gustatory Cortices in Humans

Magnetoencephalography (MEG) has recently revealed that the transitions between the parietal operculum (Pop) and the insula (area G) and the ventral end of the central sulcus (cs) were activated with the shortest latency by instrumental gustatory stimulation, which suggests that the location of the primary gustatory area is in these two regions. However, studies using other noninvasive brain-imaging methods such as positron-emission tomography or functional magnetic resonance imaging (fMRI) with manual application of tastants into the mouth have been unable to confirm this. The present study examined cortical activation by repetitive stimulation of the tongue tip with 1 M NaCl with a computer-controlled stimulator and used fMRI to detect it. In individual brains, activations were detected with multiple comparisons (false discovery rate) across the whole brain corrected (threshold at P < 0.05) at both area G and frontal operculum (Fop) in 8 of 11 subjects and at the rolandic operculum (Rop) in 7 subjects. Activations were also found at the ventral end of the cs (n = 3). Group analysis with random-effect models (multiple comparison using familywise error in regions of interest, P < 0.02) revealed activation at area G in both hemispheres and in the Fop, Rop, and ventral end of the cs on the left side. The present study revealed no activation on the gyrus of the external cerebral surface except for the Rop. Taking MEG findings into consideration, the present findings strongly indicate that the primary gustatory area is present at both the transition between the Pop and insula and the Rop including the gray matter within a ventral part of the cs.

IMPORTANCE OF CYP2D3 IN POLYMORPHISM OF DIAZEPAMP-HYDROXYLATION IN RATS

Diazepam was metabolized to three primary metabolites, 3-hydroxy-diazepam, N-desmethyl-diazepam, and p-hydroxy-diazepam. Our previous studies reported metabolic position-specific inter- or intrastrain differences in diazepam metabolism among Sprague-Dawley, Brown Norway, Dark Agouti, and Wistar rats. Especially, there were marked ( approximately 300 fold) inter- or intrastrain differences in diazepam p-hydroxylation activity at low concentration of substrate. In this study, we investigated the enzyme that catalyzes diazepam p-hydroxylation. The activity toward diazepam p-hydroxylation was inhibited by anti-cytochrome P450 2D (CYP2D) antibody, suggesting that this activity was catalyzed by CYP2D isoforms. Comparing the expression levels of the CYP2D subfamily in liver microsomes from various strains of rats using anti-CYP2D2 antibody, we found that there was a band of protein that was consistent with the phenotype of diazepam p-hydroxylation. N-terminal amino acid sequences of the specific protein exactly corresponded to those of CYP2D3, indicating that CYP2D3 might be involved in diazepam p-hydroxylation. Moreover, using rat CYP2D isoforms expressed in yeast, we tested CYP2Ds to catalyze diazepam p-hydroxylation. CYP2D1 and CYP2D2 practically did not participate in diazepam metabolism. On the other hand, diazepam p-hydroxylation was catalyzed by CYP2D3. CYP2D4 had high activity toward diazepam N-desmethylation, but not p-hydroxylation. In conclusion, the polymorphic expression of CYP2D3 caused the inter- or intrastrain differences in diazepam p-hydroxylation among rat strains or individuals.

p53-Independent ceramide formation in human glioma cells during gamma-radiation-induced apoptosis

Although the p53 tumor-suppressor gene product plays a critical role in apoptotic cell death induced by DNA-damaging chemotherapeutic agents, human glioma cells with functional p53 were more resistant to gamma-radiation than those with mutant p53. U-87 MG cells with wild-type p53 were resistant to gamma-radiation. U87-W E6 cells that lost functional p53, by the expression of type 16 human papillomavirus E6 oncoprotein, became susceptible to radiation-induced apoptosis. The formation of ceramide by acid sphingomyelinase (A-SMase), but not by neutral sphingomyelinase, was associated with p53-independent apoptosis. SR33557 (2-isopropyl-1-(4-[3-N-methyl-N-(3,4-dimethoxybphenethyl)amino]propyloxy)benzene-sulfonyl) indolizine, an inhibitor of A-SMase, suppressed radiation-induced apoptotic cell death. In contrast, radiation-induced A-SMase activation was blocked in glioma cells with endogenous functional p53. The expression of acid ceramidase was induced by gamma-radiation, and was more evident in cells with functional p53. N-oleoylethanolamine, which is known to inhibit ceramidase activity, unexpectedly downregulated acid ceramidase and accelerated radiation-induced apoptosis in U87-W E6 cells. Moreover, cells with functional p53 could be sensitized to gamma-radiation by N-oleoylethanolamine, which suppressed radiation-induced acid ceramidase expression and then enhanced ceramide formation. Sensitization to gamma-radiation was also observed in U87-MG cells depleted of functional p53 by retroviral expression of small interfering RNA. These results indicate that ceramide may function as a mediator of p53-independent apoptosis in human glioma cells in response to gamma-radiation, and suggest that p53-dependent expression of acid ceramidase and blockage of A-SMase activation play pivotal roles in protection from gamma-radiation of cells with endogenous functional p53.

Enzyme replacement therapy in Japanese Fabry disease patients: the results of a phase 2 bridging study

Fabry Disease (alpha-galactosidase A deficiency) is an X-linked hereditary disorder leading to the pathological accumulation of globotriaosylceramide (GL-3) in lysosomes, particularly in the vascular endothelium of the kidney, heart and brain. We report the results of an open-label phase 2 study that was undertaken to evaluate whether ethnic differences exist that would affect agalsidase beta (Fabrazyme) treatment of Fabry patients in the Japanese population, relative to safety and efficacy. The study design mirrored the design of the completed phase 3 clinical trial that led to approval of the product agalsidase beta. The 13 Japanese, male Fabry patients enrolled in the study received the enzyme replacement therapy over a period of 20 weeks as biweekly infusions. All selected efficacy end points showed improvements that were comparable with findings from the phase 3 study. These improvements included reductions of GL-3 accumulation in both kidney and skin capillary endothelial cells to (near) normal levels (92% of patients). Kidney and plasma GL-3 levels decreased by 51.9% and 100%, respectively, by ELISA. Renal function remained normal. Fabry-associated pain, and quality of life, showed improvement over baseline in multiple categories. Related adverse events were mild or moderate in intensity and mostly infusion-associated (fever and rigors). As expected, IgG antibody formation was observed in 85% of the patients, but had no effect on treatment response. These results suggest that treatment with agalsidase beta is safe and effective in Japanese patients with Fabry disease. With regard to safety and efficacy, no differences were observed as compared to the caucasian population.

Development of a novel microbial sensor with baker's yeast cells for monitoring temperature control during cold food chain

A novel microbial sensor containing a commercial baker's yeast with a high freeze tolerance was developed for visibly detecting inappropriate temperature control of food. When the yeast cells fermented glucose, the resulting gas production triggered the microbial sensor. The biosensor was a simple, small bag containing a solution of yeast cells, yeast extract, glucose, and glycerol sealed up with multilayer transparent film with barriers against oxygen and humidity. Fine adjustment of gas productivity in the biosensor at low temperatures was achieved by changing either or both concentrations of glucose and yeast cells. Moreover, the amount of time that food was exposed to inappropriate temperatures could be deduced by the amount of gas produced in the biosensor. The biosensor was stable without any functional loss for up to 1 week in frozen storage. The biosensor could offer a useful tool for securing food safety by maintaining low-temperature control in every stage from farm to fork, including during transportation, in the store, and at home.

Simulation Study of Distal Balloon Protection Systems during Carotid Artery Stenting

The purpose of our experimental study was to assess the pitfalls of distal balloon protection systems and to learn any technique tips to increase safety.

Silicone carotid artery models were connected to a circulatory system to simulate arterial flow. A distal balloon protection device, PercuSurge GuardWire Plus (GWP, Medtronic Vascular) was delivered to the internal carotid artery (ICA), then was inflated to occlude ICA flow temporarily. A debris aspiration catheter (Export catheter) was delivered just proximal to the GuardWire Plus balloon coaxially, in order to introduce and diffuse particulate debris (200–500 micro meter in diameter) in the ICA stump. Then, after debris in the stump was aspirated, the GWP balloon was deflated. We recorded all the processes of our simulation experiments on a digital video and observed the movements of debris during these experiments.

Exp 1) We simulated the movements of debris in the ICA stump when the GWP balloon was gradually deflated to produce a crevice between the balloon and vessel wall, simulating accidental movement of the GWP balloon during the procedure.

Exp 2) In order to assess the optimal placement of the tip of aspiration catheter, the debris in the ICA stump was aspirated from three different sites (from just below the GuardWire balloon, from 2 cm below it, and from 5 cm below it).

Exp 1) When the crevice appeared between GuardWire balloon and silicone tube, simulated debris began to concentrate just below the balloon. Then, some debris migrated distally from the crevice, and another part crowded in the crevice so that was impossible to aspirate and migrated in the end.

Exp. 2) Debris aspiration was most effective from immediately below the GuardWire balloon, and the aspiration ability declined as the distance between the balloon and aspiration catheter became longer. According to our simulation studies, when the GWP balloon was moved accidentally during CAS procedures, or when the aspiration catheter was not delivered all the way to the GuardWire Plus balloon, distal embolization might still occur, even under protection.