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.     

Ethnic differences in allele frequency of autoimmune-disease-associated SNPs

Several multiple, large-scale, genetic studies on autoimmune-disease-associated SNPs have been reported recently: peptidylarginine deiminase type 4 (PADI4) in rheumatoid arthritis (RA); solute carrier family 22 members 4 and 5 (SLC22A4 and 5) in RA and Crohns disease (CD); programmed cell death 1 (PDCD1) in systemic lupus erythematosus (SLE), type 1 diabetes mellitus (T1D), and RA; and protein tyrosine phosphatase nonreceptor type 22 (PTPN22) in T1D, RA, and SLE. Because these reports on association were not always evaluated in multiple ethnic groups and because ethnic difference in allele frequency of the variants has been also reported, we investigated allele frequencies of nine SNPs in four autoimmune-disease-associated loci in Caucasian, African-descent, and Japanese populations. Although SNPs in PADI4 had similar allele frequency among three groups [maximal difference 11%; (P >0.05)], the other three loci revealed statistically significant allele frequency differences (maximal difference 39% (P <0.00001), 13% (P <0.00001), and 8% (P <0.00001) in SLC22A4, PDCD1, and PTPN22, respectively). Of note, three SNPs in the three loci that had allele frequency more than 8% in the Caucasian population were either not polymorphic at all or extremely rare in the Japanese population. Our data suggest that ethnic variations of polymorphisms should be evaluated in detail, and differences should be incorporated into investigations of susceptibility variants for common diseases.     

Two closely related ubiquitin C-terminal hydrolase isozymes function as reciprocal modulators of germ cell apoptosis in cryptorchid testis

The experimentally induced cryptorchid mouse model is useful for elucidating the in vivo molecular mechanism of germ cell apoptosis. Apoptosis, in general, is thought to be partly regulated by the ubiquitin-proteasome system. Here, we analyzed the function of two closely related members of the ubiquitin C-terminal hydrolase (UCH) family in testicular germ cell apoptosis experimentally induced by cryptorchidism. The two enzymes, UCH-L1 and UCH-L3, deubiquitinate ubiquitin-protein conjugates and control the cellular balance of ubiquitin. The testes of gracile axonal dystrophy (gad) mice, which lack UCH-L1, were resistant to cryptorchid stress-related injury and had reduced ubiquitin levels. The level of both anti-apoptotic (Bcl-2 family and XIAP) and prosurvival (pCREB and BDNF) proteins was significantly higher in gad mice after cryptorchid stress. In contrast, Uchl3 knockout mice showed profound testicular atrophy and apoptotic germ cell loss after cryptorchid injury. Ubiquitin level was not significantly different between wild-type and Uchl3 knockout mice, whereas the levels of Nedd8 and the apoptotic proteins p53, Bax, and caspase3 were elevated in Uchl3 knockout mice. These results demonstrate that UCH-L1 and UCH-L3 function differentially to regulate the cellular levels of anti-apoptotic, prosurvival, and apoptotic proteins during testicular germ cell apoptosis.     

Role of ubiquitin carboxy terminal hydrolase-L1 in neural cell apoptosis induced by ischemic retinal injury in vivo

Ubiquitin is thought to be a stress protein that plays an important role in protecting cells under stress conditions; however, its precise role is unclear. Ubiquitin expression level is controlled by the balance of ubiquitinating and deubiquitinating enzymes. To investigate the function of deubiquitinating enzymes on ischemia-induced neural cell apoptosis in vivo, we analyzed gracile axonal dystrophy (gad) mice with an exon deletion for ubiquitin carboxy terminal hydrolase-L1 (UCH-L1), a neuron-specific deubiquitinating enzyme. In wild-type mouse retina, light stimuli and ischemic retinal injury induced strong ubiquitin expression in the inner retina, and its expression pattern was similar to that of UCH-L1. On the other hand, gad mice showed reduced ubiquitin induction after light stimuli and ischemia, whereas expression levels of antiapoptotic (Bcl-2 and XIAP) and prosurvival (brain-derived neurotrophic factor) proteins that are normally degraded by an ubiquitin-proteasome pathway were significantly higher. Consistently, ischemia-induced caspase activity and neural cell apoptosis were suppressed approximately 70% in gad mice. These results demonstrate that UCH-L1 is involved in ubiquitin expression after stress stimuli, but excessive ubiquitin induction following ischemic injury may rather lead to neural cell apoptosis in vivo.     

Exogenous antigens are processed through the endoplasmic reticulum-associated degradation (ERAD) in cross-presentation by dendritic cells

Antigen cross-presentation is critical in infectious and tumor immunity where cytotoxic T lymphocytes are induced by dendritic cells specifically equipped with cellular machineries to present exogenous antigens with major histocompatibility complex (MHC) class I molecules. To examine molecular mechanisms of antigen cross-presentation, we employed as a model system a murine dendritic cell line DC2.4 capable of presenting soluble antigens such as ovalbumin (OVA) with MHC class I. Here, we demonstrate that exogenously added OVA is accumulated in the endoplasmic reticulum (ER) and late endosomes followed by retrograde transport to the cytoplasm through the Sec61 transporter complexes, and that CHIP functions as an E3 ubiquitin-ligase for OVA degradation by proteasomes. This mechanism is essentially the same as that known as the ER-associated degradation (ERAD) in the quality control of secretary and membrane proteins.     

Transition between two forms of heterochromatin at plant subtelomeres

The manner of packing of the terminal DNA loci into nucleosomes and higher order structures may strongly influence their functional interactions. Besides the structural flexibility of telomeric DNA sequences, conserved features of their chromatin including short nucleosome phasing (157 bp) and nucleosome sliding have been described previously. To gain a complementary knowledge of subtelomeres, we have analysed the chromatin structure of two subtelomeric tandem repeats from the plant Silene latifolia: X43.1 and 15Ssp. X43.1 shows two distinct nucleosome periodicities – 157 and 188 bp. Preferred positions of its two nucleosomes have been mapped at both low and high resolution and the experimental results correspond to computer-predicted positions. 15Ssp is a newly-discovered sequence showing a telomere-associated position by PCR and a subtelomeric location by pulsed-field gel electrophoresis and fluorescence in situ hybridisation. Its 159 bp sequence unit shows a tandem arrangement and the presence of micrococcal nuclease-hypersensitive sites when either naked DNA or chromatin is digested. Use of a chemical nuclease results in a regular nucleosome ladder of 157 bp periodicity. Moreover, 15Ssp mononucleosomes show instability and absence of specific positioning, features typical for telomeric chromatin. This revised version was published online in July 2006 with corrections to the Cover Date.     

Induction Of Megamitochondria In The Rat Liver By N-Propyl Alcohol And N-Butyl Alcohol

Propyl alcohol and butyl alcohol had similar effects to ethyl alcohol on ultrastructure of liver mitochondria. Rats were given 32% ethyl alcohol, 32% n-propyl alcohol, and 6.9% n-butyl alcohol in drinking water for up to three months. After one month, mitochondria in hepatocytes obtained from the experimental animals became elongated, constricted or cup-shaped with scanty cristae. After two months, mitochondria in some hepatocytes became gigantic. In extreme cases, the megamitochondria exceeded 10 μm in diameter. Coupling efficiencies of hepatic mitochondria obtained from alcohol-fed animals were well preserved despite their drastic morphologic changes. ACTA PATHOL. JPN. 34: 471–480, 1984.     

Suppression of neointimal thickening by a newly developed HMG-CoA reductase inhibitor,BAYw6228, and its inhibitory effect on vascular smooth muscle cell growth

1. The aim of this study was to determine whether BAYw6228 (BAYw), a newly developed 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase inhibitor, could suppress an atherogenic process such as intimal thickening by a mechanism other than lowering the level of serum cholesterol.
2. First, we evaluated the in vitro effect of BAYw on the proliferation of vascular smooth muscle cells (SMC) from various species: Sprague-Dawley (SD) rats, New Zealand (NZ) white rabbits, intimal cells from Watanabe hereditary hyperlipidemic (WHHL) rabbit and SMC from the new-born human aorta. The increasing rate of total protein content of these cells was inhibited by the addition of BAYw in a dose-dependent fashion. In the presence of 2% foetal calf serum (FCS), the value of IC₅₀ was 1.0 μM in SD rats. 2.1 μM in NZ white rabbits, and 0.3 μM in WHHL rabbits. With human SMC, the value was 0.02 μM in the presence of 10% FCS and 0.2 μM with a mixture of growth factors.
3. Based on these above in vitro findings, we next examined the in vivo effect of the agent to determine whether it could suppress rabbit intimal thickening induced by balloon catheterization. A balloon catheter was inserted from a peripheral branch of the left external carotid artery to the aorta to denude the endothelium of the left common carotid artery in Japanese white rabbits. After 12 days they were divided into control and BAYw groups. The former were subcutaneously injected with saline and the latter with BAYw 1 mg kg⁻¹ day⁻¹. Two days after the beginning of treatment, a second balloon injury was performed to the previously injured left common carotid artery in both groups. After another two weeks, the left common carotid artery was removed and variously stained. Although the total serum cholesterol in the BAYw group was significantly lower than in the control (P<0.05), the difference was not enough to affect intimal thickening. In addition, the BAYw group had a smaller intima/media ratio than the control group, decreasing to 45% of control (P<0.05). By anti-α smooth muscle actin antibody staining, these intimal thickening areas were entirely occupied by SMCs, and their amount was attenuated by BAYw. By anti-rabbit macrophage antibody (RAM 11) staining, the number of positive cells in the intimal thickening was markedly decreased in the BAYw group compared to control (P<0.01).
4. These results indicate that BAYw has an inhibitory effect on intimal thickening by attenuating intimal SMC proliferation and infiltration of macrophages, suggesting that BAYw could be effective in the prevention of the progression of atherosclerotic plaque-like restenosis after angioplasty.

     

Effects of dorzolamide hydrochloride on ocular tissues.

We studied the intraocular pharmacokinetics of dorzolamide hydrochloride eye drops and the effect of dorzolamide on carbonic anhydrase activity and localization in ocular tissues. Carbonic anhydrase activity was detected in normal ocular tissues. The activity was inhibited in corneal endothelial cells, the ciliary body, lens epithelial cells, or the retina 1 to 8 hours after instillation of dorzolamide eye drops. In lens epithelial cells and the retina, the enzyme activity had not recovered even 10 hours after instillation of the drug. Immunostaining did not reveal any differences between the group administered dorzolamide eye drops and the control group administered a physiologically balanced solution. Time-related changes in dorzolamide concentrations in ocular tissues were measured by high-performance liquid chromatography (HPLC). In the cornea, anterior aqueous, iris, ciliary body and retina, drug concentrations increased 15 minutes after the instillation and peaked within 1 hour. These results suggest that dorzolamide immediately suppresses carbonic anhydrase activity in ocular tissues, and is rapidly distributed among the tissues of the eye when administered as eye drops.