PKD2, a gene for polycystic kidney disease that encodes an integral membrane protein

A second gene for autosomal dominant polycystic kidney disease was identified by positional cloning. Nonsense mutations in this gene (PKD2) segregated with the disease in three PKD2 families. The predicted 968-amino acid sequence of the PKD2 gene product has six transmembrane spans with intracellular amino- and carboxyl-termini. The PKD2 protein has amino acid similarity with PKD1, the Caenorhabditis elegans homolog of PKD1, and the family of voltage-activated calcium (and sodium) channels, and it contains a potential calcium-binding domain.

Complete genome sequence of enterohemorrhagic Escherichia coli O157:H7 and genomic comparison with a laboratory strain K-12

Escherichia coli O157:H7 is a major food-borne infectious pathogen that causes diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome. Here we report the complete chromosome sequence of an O157:H7 strain isolated from the Sakai outbreak, and the results of genomic comparison with a benign laboratory strain, K-12 MG1655. The chromosome is 5.5 Mb in size, 859 Kb larger than that of K-12. We identified a 4.1-Mb sequence highly conserved between the two strains, which may represent the fundamental backbone of the E. coli chromosome. The remaining 1.4-Mb sequence comprises of O157:H7-specific sequences, most of which are horizontally transferred foreign DNAs. The predominant roles of bacteriophages in the emergence of O157:H7 is evident by the presence of 24 prophages and prophage-like elements that occupy more than half of the O157:H7-specific sequences. The O157:H7 chromosome encodes 1632 proteins and 20 tRNAs that are not present in K-12. Among these, at least 131 proteins are assumed to have virulence-related functions. Genome-wide codon usage analysis suggested that the O157:H7-specific tRNAs are involved in the efficient expression of the strain-specific genes. A complete set of the genes specific to O157:H7 presented here sheds new insight into the pathogenicity and the physiology of O157:H7, and will open a way to fully understand the molecular mechanisms underlying the O157:H7 infection.

A muscle-specific insulin receptor knockout exhibits features of the metabolic syndrome of NIDDM without altering glucose tolerance

Skeletal muscle insulin resistance is among the earliest detectable defects in humans with type 2 diabetes mellitus. To determine the contribution of muscle insulin resistance to the metabolic phenotype of diabetes, we used the Cre-loxP system to disrupt the insulin receptor gene in mouse skeletal muscle. The muscle-specific insulin receptor knockout mice exhibit a muscle-specific > 95% reduction in receptor content and early signaling events. These mice display elevated fat mass, serum triglycerides, and free fatty acids, but blood glucose, serum insulin, and glucose tolerance are normal. Thus, insulin resistance in muscle contributes to the altered fat metabolism associated with type 2 diabetes, but tissues other than muscle appear to be more involved in insulin-regulated glucose disposal than previously recognized.

Unstable expansion of CAG repeat in hereditary dentatorubral-pallidoluysian atrophy (DRPLA)

Hereditary dentatorubral-pallidoluysian atrophy (DRPLA) is an autosomal dominant neurologic disorder characterized by variable combinations of myoclonus, epilepsy, cerebellar ataxia, choreoathetosis and dementia. By specifically searching published brain cDNA sequences for the presence of CAG repeats we identified unstable expansion of a CAG in a gene on chromosome 12 in all the 22 DRPLA patients examined. A good correlation between the size of the CAG repeat expansion and the ages of disease onset is found in this group. Patients with earlier onset tended to have a phenotype of progressive myoclonus epilepsy and larger expansions. We propose that the wide variety of clinical manifestations of DRPLA can now be explained by the variable unstable expansion of the CAG repeat.

Synaptic vesicle membrane fusion complex: action of clostridial neurotoxins on assembly

Clostridial neurotoxins inhibit neurotransmitter release by selective and specific intracellular proteolysis of synaptobrevin/VAMP, synaptosomal-associated protein of 25 kDa (SNAP-25) or syntaxin. Here we show that in binary reactions synaptobrevin binds weakly to both SNAP-25 and syntaxin, and SNAP-25 binds to syntaxin. In the presence of all three components, a dramatic increase in the interaction strengths occurs and a stable sodium dodecyl sulfate-resistant complex forms. Mapping of the interacting sequences reveals that complex formation correlates with the presence of predicted alpha-helical structures, suggesting that membrane fusion involves intermolecular interactions via coiled-coil structures. Most toxins only attack the free, and not the complexed, proteins, and proteolysis of the proteins by different clostridial neurotoxins has distinct inhibitory effects on the formation of synaptobrevin-syntaxin-SNAP-25 complexes. Our data suggest that synaptobrevin, syntaxin and SNAP-25 associate into a unique stable complex that functions in synaptic vesicle exocytosis.

Ghrelin, an endogenous growth hormone secretagogue, is a novel orexigenic peptide that antagonizes leptin action through the activation of hypothalamic neuropeptide Y/Y1 receptor pathway

Ghrelin, an endogenous ligand for growth hormone secretagogue (GHS) receptor originally isolated from the stomach, occurs in the hypothalamic arcuate nucleus and may play a role in energy homeostasis. Synthetic GHSs have activated the hypothalamic arcuate neurons containing neuropeptide Y (NPY), suggesting the involvement of NPY in some of ghrelin actions. This study was designed to elucidate the role of ghrelin in the regulation of food intake. A single intracerebroventricular (ICV) injection of ghrelin (5-5,000 ng/rat) caused a significant and dose-related increase in cumulative food intake in rats. Ghrelin (500 ng/rat) was also effective in growth hormone-deficient spontaneous dwarf rats. Hypothalamic NPY mRNA expression was increased in rats that received a single ICV injection of ghrelin (500 ng/rat) (approximately 160% of that in vehicle-treated groups, P < 0.05). The ghrelin's orexigenic effect was abolished dose-dependently by ICV co-injection of NPY Y1 receptor antagonist (10-30 microg/rat). The leptin-induced inhibition of food intake was reversed by ICV co-injection of ghrelin in a dose-dependent manner (5-500 ng/rat). Leptin reduced hypothalamic NPY mRNA expression by 35% (P < 0.05), which was abolished by ICV co-injection of ghrelin (500 ng/rat). This study provides evidence that ghrelin is an orexigenic peptide that antagonizes leptin action through the activation of hypothalamic NPY/Y1 receptor pathway.

Ca,P-rich layer formed on high-strength bioactive glass-ceramic A-W

Glass-ceramic A-W, containing crystalline apatite and wollastonite in a MgO-CaO-SiO2 glassy matrix shows high bioactivity as well as high mechanical strength, but other ceramics containing the same kinds of crystalline phases in different glassy matrices do not show the same bioactivity. In order to investigate the bone-bonding mechanism of this type of glass-ceramic, surface structural changes of the glass-ceramics after exposure to simulated body fluid were analyzed with various techniques. A solution with ion concentrations which are almost equal to those of the human blood plasma was used as the simulated body fluid, instead of Tris-buffer solution hitherto used. For analyzing the surface structural changes, thin-film x-ray diffraction was used in addition to conventional techniques. It was found that a bioactive glass-ceramic forms a Ca, P-rich layer on its surface in the fluid but nonbioactive ones do not, and that the Ca, P-rich layer consists of carbonate-containing hydroxyapatite of small crystallites and/or defective structure. These findings were common to those of Bioglass-type glasses. So, we conclude that the essential condition for glass and glass-ceramic to bond to bone is the formation of the surface apatite layer in the body environment but it is not essential to contain apatite within the material. Bioactivity of glass and glass-ceramic can be evaluated in vitro by examining the formation of the surface apatite layer in the simulated body fluid described above.

Chiral monodentate phosphine ligand MOP for transition-metal-catalyzed asymmetric reactions

Chiral monophosphines, whose chirality is due to biaryl axial chirality, have been prepared from enantiomerically pure 2, 2'-dihydroxy-1,1'-binaphthyl and demonstrated to be highly efficient chiral ligands for transition-metal-catalyzed organic transformations, especially for reactions where chelating bisphosphine ligands cannot be used. The high efficiency is observed in palladium-catalyzed asymmetric hydrosilylation of a wide variety of olefins such as alkyl-substituted terminal olefins and in asymmetric reactions via pi-allylpalladium intermediates represented by asymmetric reduction of allylic esters with formic acid.

Cisplatin-incorporating polymeric micelles (NC-6004) can reduce nephrotoxicity and neurotoxicity of cisplatin in rats

In spite of the clinical usefulness of cisplatin (CDDP), there are many occasions in which it is difficult to continue the administration of CDDP due to its nephrotoxicity and neurotoxicity. We examined the incorporation of CDDP into polymeric micelles to see if this allowed the resolution of these disadvantages. Cisplatin was incorporated into polymeric micelles through the polymer-metal complex formation between polyethylene glycol poly(glutamic acid) block copolymers and CDDP (NC-6004). The pharmacokinetics, pharmacodynamics, and toxicity studies of CDDP and NC-6004 were conducted in rats or mice. The particle size of NC-6004 was approximately 30 nm, with a narrow size distribution. In rats, the area under the curve and total body clearance values for NC-6004 were 65-fold and one-nineteenth the values for CDDP (P<0.001 and 0.01, respectively). In MKN-45-implanted mice, NC-6004 tended to show antitumour activity, which was comparable to or greater than that of CDDP. Histopathological and biochemical studies revealed that NC-6004 significantly inhibited the nephrotoxicity of CDDP. On the other hand, blood biochemistry revealed transient hepatotoxicity on day 7 after the administration of NC-6004. Furthermore, rats given CDDP showed a significant delay (P<0.05) in sensory nerve conduction velocity in their hind paws as compared with rats given NC-6004. Electron microscopy in rats given CDDP indicated the degeneration of the sciatic nerve, but these findings were not seen in rats given NC-6004. These results were presumably attributable to the significantly reduced accumulation of platinum in nerve tissue when NC-6004 was administered (P<0.05). NC-6004 preserved the antitumour activity of CDDP and reduced its nephrotoxicity and neurotoxicity, which would therefore seem to suggest that NC-6004 could allow the long-term administration of CDDP where caution against hepatic dysfunction must be exercised.

The presence of free D-serine in rat brain

Free amino acid enantiomers in adult rat brain extracts were analyzed as their N,O-pentafluoropropionyl isopropyl derivatives by gas chromatography on a capillary column of Chirasil-L-Val. A peak X, which exhibited the same retention time as the N,O-pentafluoropropionyl isopropyl derivative of authentic D-serine, was detected in the brain extracts. Electron impact and positive chemical ionization mass spectra of the peak X of the brain extracts were identical to those of authentic D-serine. The concentration of free D-serine and the ratio of D-serine/total serine in the brain were estimated to be 0.27 and 0.23 mumol/g of wet weight, respectively. These data provide the first evidence that substantial quantities of free D-serine are present in mammalian brain tissues.

Metabolic stress and altered glucose transport: activation of AMP-activated protein kinase as a unifying coupling mechanism

5'AMP-activated protein kinase (AMPK) can be activated in response to cellular fuel depletion and leads to switching off ATP-consuming pathways and switching on ATP-regenerating pathways in many cell types. We have hypothesized that AMPK is a central mediator of insulin-independent glucose transport, which enables fuel-depleted muscle cells to take up glucose for ATP regeneration under conditions of metabolic stress. To test this hypothesis, rat epitrochlearis muscles were isolated and incubated in vitro under several conditions that evoke metabolic stress accompanied by intracellular fuel depletion. Rates of glucose transport in the isolated muscles were increased by all of these conditions, including contraction (5-fold above basal), hypoxia (8-fold), 2,4-dinotrophenol (11-fold), rotenone (7-fold), and hyperosmolarity (8-fold). All of these stimuli simultaneously increased both alpha1 and alpha2 isoform-specific AMPK activity. There was close correlation between alpha1 (r2 = 0.72) and alpha2 (r2 = 0.67) AMPK activities and the rate of glucose transport, irrespective of the metabolic stress used, all of which compromised muscle fuel status as judged by ATP, phosphocreatine, and glycogen content. 5-Aminoimidazole-4-carboxamide ribonucleoside, a pharmacological AMPK activator that is metabolized to an AMP-mimetic ZMP, also increased both glucose transport and AMPK activity but did not change fuel status. Insulin stimulated glucose transport by 6.5-fold above basal but did not affect AMPK activity. These results suggest that the activation of AMPK may be a common mechanism leading to insulin-independent glucose transport in skeletal muscle under conditions of metabolic stress.

Pathophysiological role of leptin in obesity-related hypertension

To explore the pathophysiological role of leptin in obesity-related hypertension, we examined cardiovascular phenotypes of transgenic skinny mice whose elevated plasma leptin concentrations are comparable to those seen in obese subjects. We also studied genetically obese KKA(y) mice with hyperleptinemia, in which hypothalamic melanocortin system is antagonized by ectopic expression of the agouti protein. Systolic blood pressure (BP) and urinary catecholamine excretion are elevated in transgenic skinny mice relative to nontransgenic littermates. The BP elevation in transgenic skinny mice is abolished by alpha(1)-adrenergic, beta-adrenergic, or ganglionic blockers at doses that do not affect BP in nontransgenic littermates. Central administration of an alpha-melanocyte-stimulating hormone antagonist causes a marked increase in cumulative food intake but no significant changes in BP. The obese KKA(y) mice develop BP elevation with increased urinary catecholamine excretion relative to control KK mice. After a 2-week caloric restriction, BP elevation is reversed in nontransgenic littermates with the A(y) allele, in parallel with a reduction in plasma leptin concentrations, but is sustained in transgenic mice overexpressing leptin with the A(y) allele, which remain hyperleptinemic. This study demonstrates BP elevation in transgenic skinny mice and obese KKA(y) mice that are both hyperleptinemic, thereby suggesting the pathophysiological role of leptin in some forms of obesity-related hypertension.

Basal release of nitric oxide from aortic rings is greater in female rabbits than in male rabbits: implications for atherosclerosis

Estradiol is known to exert a protective effect against the development of atherosclerosis, but the mechanism of this hormonal action is unknown. One of the early events in the development of atherosclerosis is the adhesion of macrophages to endothelial cells, and nitric oxide (NO) inhibits this process. We show that basal release of NO is greater with endothelium-intact aortic rings from female rabbits than those from males. Oophorectomy diminishes both circulating estradiol concentration and basal release of NO to levels seen in male rabbits. These data establish that basal NO release from endothelium-intact aortic rings depends on circulating estradiol concentration and offer an explanation for the protective effect of estradiol against the development of atherosclerosis.

Estrogen increases endothelial nitric oxide by a receptor-mediated system

To determine the mechanism of the antiatherosclerotic effect of estrogen, we investigated the effect of estrogen on endothelial nitric oxide synthase (NOS-3). Preincubation with a physiologic concentration of 17 beta-estradiol (10(-12)-10(-8) M) over 8 hours significantly enhanced the activity of NOS-3 in endothelial cells of cultured human umblical vein (HUVEC) and of bovine aortas (BAEC). 17 beta-estradiol also enhanced the release of nitric oxide (NO) as measured by an NO selective meter and NO2-/NO3-, metabolites of NO, from endothelial cells. Western blot showed a similar effect of 17 beta-estradiol on NOS-3. The estrogen receptor antagonists, tamoxifen and ICI182780, each inhibited the effect of 17 beta-estradiol by 80%. The effect of 17 beta-estradiol gradually decreased in cells beyond the 10th passage and was not significant in cells beyond the 16th passage. Immunocytochemistry showed the existence of estrogen receptor in HUVEC and BAEC (less than 5 passages) and the sparseness of the existence in BAEC beyond the 16th passage. Estrogen increases NOS-3 via a receptor-mediated system, and estrogen receptor, which appeared to be altered by cell senescence, could be important in the release of NO from endothelium.

Identification and characterization of polycystin-2, the PKD2 gene product

PKD2, the second gene for the autosomal dominant polycystic kidney disease (ADPKD), encodes a protein, polycystin-2, with predicted structural similarity to cation channel subunits. However, the function of polycystin-2 remains unknown. We used polyclonal antisera specific for the intracellular NH(2) and COOH termini to identify polycystin-2 as an approximately 110-kDa integral membrane glycoprotein. Polycystin-2 from both native tissues and cells in culture is sensitive to Endo H suggesting the continued presence of high-mannose oligosaccharides typical of pre-middle Golgi proteins. Immunofluorescent cell staining of polycystin-2 shows a pattern consistent with localization in the endoplasmic reticulum. This finding is confirmed by co-localization with protein-disulfide isomerase as determined by double indirect immunofluorescence and co-distribution with calnexin in subcellular fractionation studies. Polycystin-2 translation products truncated at or after Gly(821) retain their exclusive endoplasmic reticulum localization while products truncated at or before Glu(787) additionally traffic to the plasma membrane. Truncation mutants that traffic to the plasma membrane acquire Endo H resistance and can be biotinylated on the cell surface in intact cells. The 34-amino acid region Glu(787)-Ser(820), containing two putative phosphorylation sites, is responsible for the exclusive endoplasmic reticulum localization of polycystin-2 and is the site of specific interaction with an as yet unidentified protein binding partner for polycystin-2. The localization of full-length polycystin-2 to intracellular membranes raises the possibility that the PKD2 gene product is a subunit of intracellular channel complexes.

Exercise induces isoform-specific increase in 5'AMP-activated protein kinase activity in human skeletal muscle

The 5'AMP-activated protein kinase (AMPK) is stimulated by contractile activity in rat skeletal muscle. AMPK has emerged as an important signaling intermediary in the regulation of cell metabolism being linked to exercise-induced changes in muscle glucose and fatty acid metabolism. In the present study, we determined the effects of exercise on isoform-specific AMPK activity (alpha1 and alpha2) in human skeletal muscle. Needle biopsies of vastus lateralis muscle were obtained from seven healthy subjects at rest, after 20 and 60 min of cycle ergometer exercise at 70% of VO(2)max, and 30 min following the 60 min exercise bout. In comparison to the resting state, AMPK alpha2 activity significantly increased at 20 and 60 min of exercise, and remained at a higher level with 30 min of recovery. AMPK alpha1 activity tended to slightly decrease with 20 min of exercise at 70%VO(2)max; however, the change was not statistically significant. AMPK alpha1 activities were at basal levels at 60 min of exercise and 30 min of recovery. On a separate day, the same subjects exercised for 20 min at 50% of VO(2)max. Exercise at this intensity did not change alpha2 activity, and similar to exercise at 70% of VO(2)max, there was no significant change in alpha1 activity. In conclusion, exercise at a higher intensity for only 20 min leads to increases in AMPK alpha2 activity but not alpha1 activity. These results suggest that the alpha2-containing AMPK complex, rather than alpha1, may be involved in the metabolic responses to exercise in human skeletal muscle.

Increase in length of leg relative to trunk in Japanese children and adults from 1957 to 1977: comparison with British and with Japanese Americans

The secular trends in height, sitting height and leg length in Japanese children have been studied by fitting Preece-Baines Model I curves to the annual mean values from ages five to 17 of school data collected in 1957, 1967 and 1977. The method provides estimates of final adult value, and of age of maximum annual increment. Between 1957 and 1977 the maximal increments in height, sitting height and leg length all became earlier, by about a year in boys and a little less in girls. Japanese now mature about a year earlier than North Europeans. Adult height increased by 4.3 cm in boys and 2.7 cm in girls between 1957 and 1977, the increment being less in the second decade than in the first. Sitting height showed practically no increase whatever; almost the whole secular trend was due to change in leg length. Japanese now have trunk/leg proportions much more similar to those of North Europeans than was the case 20 years ago, but their adult height remains about one standard deviation lower.

A clinicopathologic study of 100 cases of pulmonary sclerosing hemangioma with immunohistochemical studies: TTF-1 is expressed in both round and surface cells, suggesting an origin from primitive respiratory epithelium

Pulmonary sclerosing hemangioma (SH) is a lung neoplasm of uncertain histogenesis that is composed of two major cell types: surface and round cells. The authors studied 100 cases of pulmonary SH that presented as a peripheral (95%), solitary (96%) mass of less than 3 cm in diameter (74%) in asymptomatic patients who were mostly women (83%) with a mean age of 46.2 years. Immunohistochemistry of multiple epithelial, mesothelial, pneumocyte, neuroendocrine, and mesenchymal markers was performed on 47 cases to investigate the histogenesis of this neoplasm. Both surface and round cells stained with epithelial membrane antigen (EMA) and thyroid transcription factor-1 (TTF-1) in more than 90% of cases; however, the round cells were uniformly negative for pancytokeratin and positive for cytokeratin-7 and CAM 5.2 in only 31% and 17% of cases, respectively. Surfactant proteins A and B as well as Clara cell antigen were positive in varying numbers of surface cells but they were negative in the round cells. Neuroendocrine cells either as isolated scattered cells or as a tumorlet within the center of SH were detected (chromogranin, Leu-7, synaptophysin positive) in three cases. The expression of TTF-1 in the absence of surfactant proteins A and B and Clara cell antigens in the round cells of SH suggests that they are derived from primitive respiratory epithelium. The alveolar pneumocytes and neuroendocrine cells may either represent phenotypic differentiation of a primitive respiratory epithelial component or they may correspond to non-neoplastic entrapped or hyperplastic elements. The concomitant positivity of both cell types in SH for TTF-1 and EMA, and the negativity of round cells for pancytokeratin and neuroendocrine markers, provide useful clues not only for histogenesis but also for the diagnosis of this lung neoplasm.

Rapid induction of vascular endothelial growth factor gene expression after transient middle cerebral artery occlusion in rats

BACKGROUND AND PURPOSE

Vascular endothelial growth factor (VEGF) is a mitogen for endothelial cells and also has the potential to increase vascular permeability. Therefore, it may contribute to the recovery of brain cells from ischemic insult through potentiating neovascularization or may exacerbate brain damage by forming brain edema. However, the exact role of this protein in cerebral ischemia is not fully understood. We investigated temporal, spatial, and cellular profiles of the induction of VEGF gene expression after transient focal cerebral ischemia at both mRNA and protein levels.

METHODS

We used a transient middle cerebral artery (MCA) occlusion model. Northern blot analysis was performed to assess the chronological pattern of induction and the impact of length of ischemia on mRNA expression. Western blot analysis was performed to ensure the selective detection of immunoreactive VEGF with an antibody. Temporal, spatial, and cellular changes of immunohistochemical VEGF expression were compared with different periods of reperfusion from 1 hour to 7 days after transient MCA occlusion.

RESULTS

(1) Northern blot analysis revealed no detectable VEGF mRNA in the control brains. The mRNA became evident at 1 hour after reperfusion, peaked at 3 hours, and then decreased. The length of ischemia from 1 to 3 hours made no differences in the degree and temporal profile of the subsequent induction of VEGF mRNA. (2) Western blot analysis showed no band in the control brain, but two bands with molecular weights of 38 and 45 kD, corresponding to VEGF121 and VEGF165, were induced at 1 hour of reperfusion, peaked at 3 hours of reperfusion, and then decayed. (3) Neurons in the cerebral cortex of the MCA territory expressed VEGF at 1 hour after reperfusion with a peak at 3 hours and then diminished by 1 day. Pial cells of the MCA territory also expressed immunoreactive VEGF from 1 hour of reperfusion that was sustained until 3 to 7 days after reperfusion.

CONCLUSIONS

Rapid induction of VEGF gene expression after transient MCA occlusion was demonstrated at both mRNA and protein levels. Cortical neurons and pial cells were the source of VEGF production in this model, but the temporal profiles of the induction between these cells were different. The early but dissociative induction of VEGF between neuronal and pial cells suggests different roles of the protein in their cells after transient MCA occlusion.

Incidence and factors associated with intrahepatic recurrence following resection of hepatocellular carcinoma

BACKGROUND

The long-term survival rate after liver resection of hepatocellular carcinoma (HCC) is far from satisfactory, mainly because of high intrahepatic recurrence (IHR) rates. This study was aimed to clarify clinicopathologic factors relevant to IHR after resection of HCC.

METHODS

The 10-year cumulative intrahepatic recurrence rates were analyzed in terms of seven clinical and eight pathological factors in 201 patients with curative hepatic resection.

RESULTS

IHR was found in 121 patients during the follow-up period. The overall IHR rates were 22% at 1 year, 43% at 2 years, 62% at 3 years, 72% at 4 years, 75% at 5 years, and 75% at 10 years. Age, sex, and serum alpha-fetoprotein level, hepatitis B virus markers, and extent of liver resection were not significantly related to the IHR rate. Postoperative chemotherapy mainly with anthracycline tended to suppress IHR (P = 0.0889), but preoperative chemoembolization did not affect IHR. The presence of cirrhosis, satellite nodules, and venous invasion and the absence of capsule formation were associated with higher recurrence rates throughout the observation. Positive surgical margin (< or = 5 mm) was also associated with a higher IHR rate. Although not significant, well-differentiated HCCs showed a higher recurrence rate in comparison with poorly differentiated tumors. Size and number of tumor did not influence the IHR rate.

CONCLUSIONS

Accurate patient selection and adequate hepatic reserve are important considerations in the management of HCC by resection.

Reduction of ischemic damage by application of vascular endothelial growth factor in rat brain after transient ischemia

Vascular endothelial growth factor (VEGF) is a secreted polypeptide and plays a pivotal role in angiogenesis in vivo. However, it also increases vascular permeability, and might exacerbate ischemic brain edema. The effect of this factor on the brain after transient ischemia was investigated in terms of infarct volume and edema formation, as well as cellular injury. After 90 minutes of transient middle cerebral artery occlusion, VEGF (1.0 ng/microL, 9 microL) was topically applied on the surface of the reperfused rat brain. A significant reduction of infarct volume was found in animals with VEGF application (P < 0.001) at 24 hours of reperfusion as compared with cases with vehicle treatment. Brain edema was significantly reduced in VEGF-treated animals (P = 0.01), and furthermore, extravasation of Evans blue was also decreased in those animals (P < 0.01). Terminal deoxynucleotidyl transferase-mediated dUTP-biotin in situ nick end labeling and immunohistochemical analysis for 70-kDa heat shock protein showed an amelioration of the stainings at 24 and 48 hours after reperfusion with VEGF treatment, which indicated reduction of neuronal damage. These results indicate that treatment with topical VEGF application significantly reduces ischemic brain damage, such as infarct volume, edema formation, and extravasation of Evans blue, and that the reductions were associated with that of neuronal injury.