Plasticity of central monoaminergic systems during aging]

The locus coeruleus (LC), located within the caudal pontine central gray, is composed of noradrenaline-containing neurons. The axons of these neurons form extensive collateral branches that project widely to many brain sites. The function of the LC is still unclear at present, however, LC neurons are known to exhibit marked axonal regeneration and sprouting in response to brain damage. We investigated the age-related changes in noradrenergic innervations of the frontal cortex, using in vivo electrophysiological techniques and immunohistochemistry. While noradrenergic innervations gradually decreased with age in the frontal cortex, a high degree of sprouting occurred in the LC axon terminals in middle age. Neither the electrophysiological properties of LC neurons nor NA levels in the frontal cortex changed with age. These findings suggested that the LC neurons preserve a strong capacity to remodel their axon terminals even in the aging brain. Exogenous brain-derived neurotrophic factor (BDNF) infusion caused a marked increase in the density of noradrenergic axon in the aged brain, but no trophic action of BDNF was observed in the young or middle-aged brain. The result suggests that BDNF is necessary for the maintenance of noradrenergic innervations in the aged brain.     

Visual event-related potentials in progressive supranuclear palsy, corticobasal degeneration, striatonigral degeneration, and Parkinson's disease

To determine whether there are characteristic changes in event-related potentials (ERPs) in parkinsonian syndromes we studied 8 patients with progressive supranuclear palsy (PSP), 10 patients with corticobasal degeneration (CBD), 9 patients with striatonigral degeneration (SND), and 16 patients with idiopathic Parkinson's disease (PD) with a mean duration of illness shorter than 5 years in each group. A visual oddball paradigm was employed to elicit P300. P300 to the rare target and rare nontarget stimuli and reaction time (RT) to rare target stimuli in each group were compared with those in the corresponding age-matched normal control group and to each other after age correction. The correlation of P300 and RT to motor disability score was also studied. In PSP P300 amplitude was markedly reduced while in CBD P300 latency was prolonged. P300 amplitude to rare nontargets in SND and PD was attenuated. The mean RT in the PSP and the CBD group was significantly longer than in the other two groups. The mean RT in PD and P300 amplitude to rare nontargets in both CBD and PD showed significant correlation with the severity of motor disability. Simultaneous measurement of P300 and RT may yield useful supplementary information in facilitating diagnosis of parkinsonian syndromes in addition to clinical criteria. Received: 6 April 1999, Received in revised form: 5 August 1999, Accepted: 12 January 2000     

Serine protease inhibitors prevent alcoholic liver injury]

The hepatotoxic effects of alcohol have been described in detail, but factors responsible for its hepatotoxicity have only partially characterized. It now appears that Kupffer cell derived TNF-alpha participates in several aspects of alcoholic liver injury. On the other hand, protease inhibitors have been used successfully for treatment of intractable diseases in which TNF-alpha is involved in the pathogenesis, including ulcerative colitis and Crohn's disease. Here, we will review new evidence for the proposal that serine protease inhibitors prevents alcoholic liver injury via mechanisms dependent on Kupffer cell derived TNF-alpha.     

Gender difference in alcoholic liver injury]

Gender differences of alcoholic liver injury have been described previously, but mechanisms have only partially characterized. For example, it is known that females develop alcoholic liver injury more rapidly and to a greater extent than males. It now appears that estrogen participates in several aspects of this phenomenon. On the other hand, attention has been directed towards the effect of ethanol ingestion on Kupffer cell function, which is stimulated by gut-derived endotoxins via mechanisms dependent on increased gut permeability and the possible relationship between Kupffer cell and alcohol-induced liver injury.     

Long-lasting renal dysfunction following tacrolimus induction therapy in ulcerative colitis patients

Although tacrolimus (TAC) has remarkable effects in ulcerative colitis (UC) patients when given as remission induction therapy, some can develop renal dysfunction during TAC administration, resulting in withdrawal, though related details remain poorly understood. This study was conducted to determine the impact of oral TAC on renal function for remission induction therapy in UC patients. Fifty-five patients (10 elderly, 45 non-elderly) with UC and treated with oral TAC at our hospital were retrospectively evaluated. Renal function was assessed using estimated glomerular filtration rate (eGFR). Although a high clinical response to TAC was seen in both elderly and non-elderly, a decline in eGFR was noted in nearly all patients regardless of age, with a maximum change of −34.4% from the baseline value at week 11. Furthermore, eGFR decline recovered quickly after TAC discontinuation, though did not return to the baseline at two years following cessation. The rate of eGFR change at week 12 was significantly associated with patient age (β = −0.3242, p = 0.0103) and peak serum trough level during TAC treatment (β = 0.3563, p = 0.0051). Furthermore, the rate of decline in eGFR was significantly greater during treatment with TAC in the elderly as compared to non-elderly, with a large difference in eGFR decline rate between those groups also noted at two years after withdrawal of treatment. Careful attention to renal function when administering oral TAC for UC is important and changes in eGFR should be monitored closely in elderly patients even after treatment cessation.     

Decreased portal vein flow during Kawasaki disease in a liver transplant patient

Abnormalities of liver function tests are frequently documented in patients with Kawasaki disease, but the mechanism responsible for this has not yet been established. Described herein is the case of a 1‐year‐10‐month‐old girl who underwent liver transplantation at 11 months of age. Eleven months after transplantation the patient was diagnosed with Kawasaki disease, which was associated with some portal flow reduction, and received i.v. immunoglobulin, after which fever abated with improvement of portal flow to its pre‐fever level. Abnormalities of liver function tests in Kawasaki disease patients may occur as a result of inflammation of both the biliary and portal systems. There are no reports on the potential relationship between Kawasaki disease and the portal vein, and accumulation of further data is necessary to better examine this relationship.     

A novel hepatic-targeting system for therapeutic cytokines that delivers to the hepatic asialoglycoprotein receptor,but avoids receptor-mediated endocytosis

Purpose. To demonstrate the utilities of a synthetic low-affinity ligand ((Gal)₃) for the asialoglycoprotein receptor (ASGP-R) as a hepatic targeting device for therapeutic cytokines. Methods. The site-specific incorporation of (Gal)₃ or a typical high-affinity ligand (GalNAc)₃ into IL-2 was catalyzed by microbial transglutaminase. The anti-tumor activities, pharmacokinetic profiles and receptor-mediated endocytosis in hepatocytes of the ligand-IL-2 conjugates were examined in mouse. Results. The (Gal)₃ has approximately 50 times lower affinity to ASGP-R than (GalNAc)₃. Nevertheless, the antitumor effects were in the order of (Gal)₃—IL-2 > unmodified IL-2 > (GalNAc)₃—IL-2. The systemic elimination and the hepatic uptake of (GalNAc)₃—IL-2 were more rapid than (Gal)₃—IL-2. The ratio of the rate constant representing dissociation from the cell-surface receptor (k_off) to that representing endocytosis of the ligand (k_int) was greater for (Gal)₃—IL-2 than (GalNAc)₃—IL-2, suggesting that (Gal)₃—IL-2 preferably avoids internalization due to its lower affinity to the receptor. The simulation studies demonstrated that (Gal)₃—IL-2 was present in the hepatic extracellular space for a longer period than (GalNAc)₃ IL-2. Conclusions. The (Gal)₃ ligand increases the therapeutic efficacy of IL-2 by enhancing its exposure to the cell-surface. The k_off/k_int affects the targeting efficacy of the conjugates to ASGP-R.     

Formulation Optimization of Paclitaxel Carried by PEGylated Emulsions Based on Artificial Neural Network

PURPOSE: To develop paclitaxel carried by injectable PEGylated emulsions, an artificial neural network (ANN) was used to optimize the formulation--which has a small particle size, high entrapment efficiency, and good stability--and to investigate the role of each ingredient in the emulsion. METHODS: Paclitaxel emulsions were prepared by a modified ethanol injection method. A computer optimization technique based on a spherical experimental design for three-level, three factors [soybean oil (X1), PEG-DSPE (X2) and polysorbate 80 (X3)] were used to optimize the formulation. The entrapment efficiency of paclitaxel (Y1) was quantified by HPLC; the particle size of the emulsions (Y2) was measured by dynamic laser light scattering and the stability of paclitaxel emulsions was monitored by the changes in drug concentration (Y3) and particle size (Y4) after storage at 4 degrees C. RESULTS: The entrapment efficiency, particle size and stability of paclitaxel emulsions were influenced by PEG-DSPE, polysorbate 80, and soybean oil. Paclitaxel emulsions of small size (262 nm), high entrapment efficiency (96.7%), and good stability were obtained by the optimization. CONCLUSIONS: A novel formulation for paclitaxel emulsions was optimized with ANN and prepared. The contribution indices of each component suggested that PEG-DSPE mainly contributes to the entrapment efficiency and particle size of paclitaxel emulsions, while polysorbate 80 contributes to stability.     

Hypoxic status in ovarian serous and mucinous tumors: relationship between histological characteristics and HIF-1α/GLUT-1 expression

Material and methods We analyzed the expression of hypoxia inducible factor-1α (HIF-1α) and glucose transporter-1 (GLUT-1) by immunohistochemistry in ovarian serous and mucinous tumors from the point view of the histological characteristics and acquisition of malignancy. A total of 102 ovarian tumors were examined, composed of 31 adenomas (serous 17 and mucinous 14), 32 borderline tumors (serous 13 and mucinous 19), and 39 adenocarcinomas (serous 21 and mucinous 18). Results The overall positive ratios were as follows: HIF-1α, 74% of adenomas, 91% of borderline tumors, and 100% of adenocarcinomas; and GLUT-1, 68% of adenomas, 95% of borderline tumors, and 100% of adenocarcinomas. Comparing serous tumors and mucinous tumors, there was no significant difference in the positive ratios of HIF-1α and GLUT-1 of adenomas, borderline tumors, and adenocarcinomas. However, both markers were more strongly expressed in serous adenocarcinomas (HIF-1α, 3 + 100%; GLUT-1, 3 + 76%) than in mucinous adenocarcinomas (HIF-1α, 3 + 61%; GLUT-1, 3 + 28%). The results of immunoblotting and mRNA expression level analyses corresponded with those of immunohistochemical expression profiles. DNA binding assay also demonstrated that HIF-1 is more commonly activated in serous adenocarcinomas than in mucinous adenocarcinomas. Conclusion HIF-1α and GLUT-1 expressions seemed to be coordinated to adapt ovarian tumor cells into hypoxic conditions in close association with the acquisition of malignancy. We consider that the relatively strong expression of both markers in serous tumors compared with mucinous tumors is related to the difference in their histological characteristics.