Radiation dosimetry and pharmacokinetics of the tau PET tracer florzolotau (18F) in healthy Japanese subjects

OBJECTIVE

Abnormal aggregation of tau in the brain is a major contributing factor in various neurodegenerative diseases. Florzolotau (18F) (florzolotau, APN-1607, PM-PBB3) has been shown to be a probe for tau fibrils in an animal model and patients with Alzheimer's disease and those with non-Alzheimer's disease tauopathies. The objective of this study is to evaluate the safety, pharmacokinetics, and radiation dose following a single intravenous administration of florzolotau in healthy Japanese subjects.

METHODS

Three healthy male Japanese subjects aged between 20 and 64 were enrolled in this study. Subjects were determined to be eligible based on the screening assessments at the study site. Subjects received a single intravenous dose of 195.0 ± 0.5 MBq of florzolotau and underwent the whole-body PET scan 10 times in total to calculate absorbed doses to major organs/tissues and effective dose. Radioactivities in whole blood and urine were also measured for pharmacokinetic evaluation. Absorbed doses to major organs/tissues and effective dose were estimated using the medical internal radiation dose (MIRD) method. Vital signs, electrocardiography (ECG), and blood tests were done for safety evaluation.

RESULTS

The intravenous injection of florzolotau was well tolerated. There were no adverse events or clinically detectable pharmacologic effects related to the tracer in any subjects. No significant changes in vital signs and ECG were observed. The highest mean initial uptake at 15 min after injection was in the liver (29.0 ± 4.0%ID), intestine (4.69 ± 1.65%ID), and brain (2.13 ± 0.18%ID). The highest absorbed dose was 508 μGy/MBq of the gallbladder wall, followed by the liver of 79.4 μGy/MBq, the pancreas of 42.5 μGy/MBq, and the upper large intestine of 34.2 μGy/MBq. The effective dose was calculated as 19.7 μSv/MBq according to the tissue weighting factor reported by ICRP-103.

CONCLUSION

Florzolotau intravenous injection was well tolerated in healthy male Japanese subjects. The effective dose was determined as 3.61 mSv when 185 MBq florzolotau was given.

Clinical Utility of 18 F-APN-1607 Tau PET Imaging in Patients with Progressive Supranuclear Palsy

BACKGROUND

¹⁸ F-APN-1607 is a novel tau PET tracer characterized by high binding affinity for 3- and 4-repeat tau deposits. Whether ¹⁸ F-APN-1607 PET imaging is clinically useful in PSP remains unclear.

OBJECTIVES

The objective of this study was to investigate the clinical utility of ¹⁸ F-APN-1607 PET in the diagnosis, differential diagnosis, and assessment of disease severity in patients with PSP.

METHODS

We enrolled 3 groups consisting of patients with PSP (n = 20), patients with α-synucleinopathies (MSA with predominant parkinsonism, n = 7; PD, n = 10), and age- and sex-matched healthy controls (n = 13). The binding patterns of ¹⁸ F-APN-1607 in PET/CT imaging were investigated. Regional standardized uptake ratios were compared across groups and examined in relation to their utility in the differential diagnosis of PSP versus α-synucleinopathies. Finally, the relationships between clinical severity scores and ¹⁸ F-APN-1607 uptake were investigated after adjustment for age, sex, and disease duration.

RESULTS

Compared with healthy controls, patients with PSP showed increased ¹⁸ F-APN-1607 binding in several subcortical regions, including the striatum, putamen, globus pallidus, thalamus, subthalamic nucleus, midbrain, tegmentum, substantia nigra, pontine base, red nucleus, raphe nuclei, and locus coeruleus. We identified specific regions that were capable of distinguishing PSP from α-synucleinopathies. The severity of PSP was positively correlated with the amount of ¹⁸ F-APN-1607 uptake in the subthalamic nucleus, midbrain, substantia nigra, red nucleus, pontine base, and raphe nuclei.

CONCLUSIONS

¹⁸ F-APN-1607 PET imaging holds promise for the diagnosis, differential diagnosis, and assessment of disease severity in patients with PSP. © 2021 International Parkinson and Movement Disorder Society.

Correction to: Cryo-EM structures of tau filaments from Alzheimer's disease with PET ligand APN-1607

A correction to this paper has been published: https://doi.org/10.1007/s00401-021-02303-5

Cryo-EM structures of tau filaments from Alzheimer's disease with PET ligand APN-1607

Tau and Aβ assemblies of Alzheimer’s disease (AD) can be visualized in living subjects using positron emission tomography (PET). Tau assemblies comprise paired helical and straight filaments (PHFs and SFs). APN-1607 (PM-PBB3) is a recently described PET ligand for AD and other tau proteinopathies. Since it is not known where in the tau folds PET ligands bind, we used electron cryo-microscopy (cryo-EM) to determine the binding sites of APN-1607 in the Alzheimer fold. We identified two major sites in the β-helix of PHFs and SFs and a third major site in the C-shaped cavity of SFs. In addition, we report that tau filaments from posterior cortical atrophy (PCA) and primary age-related tauopathy (PART) are identical to those from AD. In support, fluorescence labelling showed binding of APN-1607 to intraneuronal inclusions in AD, PART and PCA. Knowledge of the binding modes of APN-1607 to tau filaments may lead to the development of new ligands with increased specificity and binding activity. We show that cryo-EM can be used to identify the binding sites of small molecules in amyloid filaments.

Characterization of 18F-PM-PBB3 (18F-APN-1607) Uptake in the rTg4510 Mouse Model of Tauopathy

Misfolding, aggregation, and cerebral accumulation of tau deposits are hallmark features of Alzheimer’s disease. Positron emission tomography study of tau can facilitate the development of anti-tau treatment. Here, we investigated a novel tau tracer ¹⁸F-PM-PBB3 (¹⁸F-APN-1607) in a mouse model of tauopathy. Dynamic PET scans were collected in groups of rTg4510 transgenic mice at 2–11 months of age. Associations between distribution volume ratios (DVR) and standardized uptake value ratios (SUVR) with cerebellum reference were used to determine the optimal scanning time and uptake pattern for each age. Immunohistochemistry staining of neurofibrillary tangles and autoradiography study was performed for ex vivo validation. An SUVR 40–70 min was most consistently correlated with DVR and was used in further analyses. Significant increased ¹⁸F-PM-PBB3 uptake in the brain cortex was found in six-month-old mice (+28.9%, p < 0.05), and increased further in the nine-month-old group (+38.8%, p < 0.01). The trend of increased SUVR value remained evident in the hippocampus and striatum regions except for cortex where uptake becomes slightly reduced in 11-month-old animals (+37.3%, p < 0.05). Radioactivity distributions from autoradiography correlate well to the presence of human tau (HT7 antibody) and hyperphosphorylated tau (antibody AT8) from the immunohistochemistry study of the adjacent brain sections. These findings supported that the 40–70 min ¹⁸F-PM-PBB3 PET scan with SUVR measurement can detect significantly increased tau deposits in a living rTg4510 transgenic mouse models as early as six-months-old. The result exhibited promising dynamic imaging capability of this novel tau tracer, and the above image characteristics should be considered in the design of longitudinal preclinical tau image studies.

In vivo axonal transport deficits in a mouse model of fronto-temporal dementia

Background

Axonal transport is vital for neurons and deficits in this process have been previously reported in a few mouse models of Alzheimer's disease prior to the appearance of plaques and tangles. However, it remains to be determined whether axonal transport is defective prior to the onset of neurodegeneration. The rTg4510 mouse, a fronto-temporal dementia and parkinsonism-17 (FTDP-17) tauopathy model, over-express tau-P301L mutation found in familial forms of FTDP-17, in the forebrain driven by the calcium–calmodulin kinase II promoter. This mouse model exhibits tau pathology, neurodegeneration in the forebrain, and associated behavioral deficits beginning at 4–5 months of age.

Animal model

rTg4510 transgenic mice were used in these studies. Mice were given 2 μL of MnCl₂ in each nostril 1 h prior to Magnetic Resonance Imaging (MRI). Following MnCl₂ nasal lavage, mice were imaged using Manganese enhanced Magnetic Resonance Imaging (MEMRI) Protocol with TE = 8.5 ms, TR = 504 ms, FOV = 3.0 cm, matrix size = 128 × 128 × 128, number of cycles = 15 with each cycle taking approximately 2 min, 9 s, and 24 ms using Paravision software (BrukerBioSpin, Billerica, MA). During imaging, body temperature was maintained at 37.0 °C using an animal heating system (SA Instruments, Stony Brook, NY).

Data analysis

Resulting images were analyzed using Paravision software. Regions of interest (ROI) within the olfactory neuronal layer (ONL) and the water phantom consisting of one pixel (ONL) and 9 pixels (water) were selected and copied across each of the 15 cycles. Signal intensities (SI) of ONL and water phantom ROIs were measured. SI values obtained for ONL were then normalized the water phantom SI values. The correlation between normalized signal intensity in the ONL and time were assessed using Prism (GraphPad Software, San Diego, CA).

Results

Using the MEMRI technique on 1.5, 3, 5, and 10-month old rTg4510 mice and littermate controls, we found significant axonal transport deficits present in the rTg4510 mice beginning at 3 months of age in an age-dependent manner. Using linear regression analysis, we measured rates of axonal transport at 1.5, 3, 5, and 10 months of age in rTg4510 and WT mice. Axonal transport rates were observed in rTg4510 mice at 48% of WT levels at 3 months, 40% of WT levels at 5 months, and 30% of WT levels at 10 months of age. In order to determine the point at which tau appears in the cortex, we probed for phosphorylated tau levels, and found that pSer262 is present at 3 months of age, not earlier at 1.5 months of age, but observed no pathological tau species until 6 months of age, months after the onset of the transport deficits. In addition, we saw localization of tau in the ONL at 6 months of age.

Discussion

In our study, we identified the presence of age-dependent axonal transport deficits beginning at 3 months of age in rTg4510 mice. We correlated these deficits at 3 months to the presence of hyperphosphorylated tau in the brain and the presence within the olfactory epithelium. We observed tau pathology not only in the soma of these neurons but also within the axons and processes of these neurons. Our characterization of axonal transport in this tauopathy model provides a functional time point that can be used for future therapeutic interventions.

•

We used MEMRI to define axonal transport rate changes in the rTg4510 mouse.

•

We observed significant hyperphosphorylated tau starting at 3 months of age.

•

We found an age-dependent decline in axonal transport rates.

•

Declines in axonal transport correlated with increases in hyperphosphorylated tau.

Imaging of tau pathology in a tauopathy mouse model and in Alzheimer patients compared to normal controls

Accumulation of intracellular tau fibrils has been the focus of research on the mechanisms of neurodegeneration in Alzheimer's disease (AD) and related tauopathies. Here, we have developed a class of tau ligands, phenyl/pyridinyl-butadienyl-benzothiazoles/benzothiazoliums (PBBs), for visualizing diverse tau inclusions in brains of living patients with AD or non-AD tauopathies and animal models of these disorders. In vivo optical and positron emission tomographic (PET) imaging of a transgenic mouse model demonstrated sensitive detection of tau inclusions by PBBs. A pyridinated PBB, [(11)C]PBB3, was next applied in a clinical PET study, and its robust signal in the AD hippocampus wherein tau pathology is enriched contrasted strikingly with that of a senile plaque radioligand, [(11)C]Pittsburgh Compound-B ([(11)C]PIB). [(11)C]PBB3-PET data were also consistent with the spreading of tau pathology with AD progression. Furthermore, increased [(11)C]PBB3 signals were found in a corticobasal syndrome patient negative for [(11)C]PIB-PET.

The neuroactive steroid pregnenolone sulfate stimulates trafficking of functional N-methyl D-aspartate receptors to the cell surface via a noncanonical, G protein, and Ca2+-dependent mechanism

N-methyl D-aspartate (NMDA) receptors (NMDARs) mediate fast excitatory synaptic transmission and play a critical role in synaptic plasticity associated with learning and memory. NMDAR hypoactivity has been implicated in the pathophysiology of schizophrenia, and clinical studies have revealed reduced negative symptoms of schizophrenia with a dose of pregnenolone that elevates serum levels of the neuroactive steroid pregnenolone sulfate (PregS). This report describes a novel process of delayed-onset potentiation whereby PregS approximately doubles the cell's response to NMDA via a mechanism that is pharmacologically and kinetically distinct from rapid positive allosteric modulation by PregS. The number of functional cell-surface NMDARs in cortical neurons increases 60-100% within 10 minutes of exposure to PregS, as shown by surface biotinylation and affinity purification. Delayed-onset potentiation is reversible and selective for expressed receptors containing the NMDAR subunit subtype 2A (NR2A) or NR2B, but not the NR2C or NR2D, subunits. Moreover, substitution of NR2B J/K helices and M4 domain with the corresponding region of NR2D ablates rapid allosteric potentiation of the NMDA response by PregS but not delayed-onset potentiation. This demonstrates that the initial phase of rapid positive allosteric modulation is not a first step in NMDAR upregulation. Delayed-onset potentiation by PregS occurs via a noncanonical, pertussis toxin-sensitive, G protein-coupled, and Ca(2+)-dependent mechanism that is independent of NMDAR ion channel activation. Further investigation into the sequelae for PregS-stimulated trafficking of NMDARs to the neuronal cell surface may uncover a new target for the pharmacological treatment of disorders in which NMDAR hypofunction has been implicated.

Long-term efficacy of entecavir in adefovir-refractory chronic hepatitis B patients with prior lamivudine resistance

This study aimed to evaluate the long-term efficacy of entecavir (ETV) in adefovir (ADV)-refractory chronic hepatitis B (CHB) patients with prior lamivudine (LMV) resistance. A total of 55 ADV-refractory CHB patients with prior LMV resistance, who received rescue therapy with ETV 1 mg daily for at least 12 months, were consecutively enrolled and analysed. Forty-four patients were men, and their median age was 47 (25-69). Ten patients had liver cirrhosis and 46 patients were positive for hepatitis B e antigen (HBeAg). Median hepatitis B virus DNA levels were 6.6 (4.3-8.0) log(10) copies/mL, and the median duration of ETV therapy was 24 (12-47) months. Cumulative virologic response rates at 6, 12, 24 and 36 months were 18%, 29%, 58% and 75%, respectively. HBeAg loss occurred in 10 (21.7%) of 46 HBeAg-positive patients. In multivariate analysis, only initial virologic response at 3 months remained as an independent predictor for virologic response (RR 3.143; 95% CI 1.387-7.120; P = 0.006). The patients with a virological response at 3 months had not only a significantly higher probability of achieving a virologic response (P < 0.001) but also lower probability of experiencing a virologic breakthrough (P = 0.043) than the patients without an early response. Viral breakthrough was observed in 29 patients during the follow-up period. Cumulative breakthrough rates at 6, 12, 24 and 36 months were 0%, 15%, 45% and 73%, respectively. ETV monotherapy may be considerably efficacious in cases with an initial virological response but its efficacy is attenuated by frequent emergence of ETV resistance in ADV-refractory CHB patients with prior LMV resistance.

A steroid modulatory domain in NR2A collaborates with NR1 exon-5 to control NMDAR modulation by pregnenolone sulfate and protons

NMDA receptor (NMDAR)-mediated excitatory synaptic transmission plays a critical role in synaptic plasticity and memory formation, whereas its dysfunction may underlie neuropsychiatric and neurodegenerative diseases. The neuroactive steroid pregnenolone sulfate (PS) acts as a cognitive enhancer in impaired animals, augments LTP in hippocampal slices by enhancing NMDAR activity, and may participate in the reduction of schizophrenia's negative symptoms by systemic pregnenolone. We report that the effects of PS on NMDAR function are diverse, varying with subunit composition and NR1 splice variant. While PS potentiates NR1-1a/NR2B receptors through a critical steroid modulatory domain in NR2B that also modulates tonic proton inhibition, potentiation of the NMDA response is not dependent upon relief of such inhibition, a finding that distinguishes it from spermine. In contrast, the presence of an NR2A subunit confers enhanced PS-potentiation at reduced pH, suggesting that it may indeed act like spermine does at NR2B-containing receptors. Additional tuning of the NMDAR response by PS comes via the N-terminal exon-5 splicing insert of NR1-1b, which regulates the magnitude of proton-dependent PS potentiation. For NR2C- and NR2D-containing receptors, negative modulation at NR2C receptors is pH-independent (like NR2B) while negative modulation at NR2D receptors is pH-dependent (like NR2A). Taken together, PS displays a rich modulatory repertoire that takes advantage of the structural diversity of NMDARs in the CNS. The differential pH sensitivity of NMDAR isoforms to PS modulation may be especially important given the emerging role of proton sensors to both learning and memory, as well as brain injury.

Aspartate aminotransferase to platelet ratio index (APRI) can predict liver fibrosis in chronic hepatitis B

BACKGROUND

There have been still few valuable markers that can be used as indirect markers of liver fibrosis in chronic hepatitis B.

AIMS

This study aimed to evaluate efficacy of several indirect markers of liver fibrosis and to identify the most valuable test in chronic hepatitis B.

PATIENTS AND METHODS

A total of 264 patients with chronic hepatitis B were consecutively enrolled. Fibrosis was staged by a single blinded pathologist according to the METAVIR system. Significant fibrosis was defined as stage >or=2. We investigated diagnostic accuracy of four indirect markers including aspartate aminotransferase to platelet ratio index for predicting significant fibrosis.

RESULTS

Mean age was 28 years. 53% (141/264) had significant hepatic fibrosis. Of indirect markers, aspartate aminotransferase to platelet ratio index yielded the best area under the receiver operating characteristic curve (0.86; 95% confidence interval, 0.82-0.91). Positive predictive value/negative predictive value at 0.5, 1.5 and 2.0 of aspartate aminotransferase to platelet ratio index score for predicting significant fibrosis were 63%/91%, 83%/74% and 86%/65%, respectively. The odds ratio for aspartate aminotransferase to platelet ratio index >or=1.4 relative to less than aspartate aminotransferase to platelet ratio index of 1.4 was 17.971 (p<0.0001; 95% confidence interval, 9.677-33.376).

CONCLUSIONS

Of simple markers already developed in chronic hepatitis C, aspartate aminotransferase to platelet ratio index may be the most accurate and simple marker for predicting significant fibrosis in chronic hepatitis B.

Five-aminoimidazole-4-carboxamide-1-beta-4-ribofuranoside attenuates poly (I:C)-induced airway inflammation in a murine model of asthma

BACKGROUND

Asthma can frequently be induced or exacerbated by respiratory viral infections. Oxidative stress might also play an essential role in the pathogenesis of allergic airway diseases, indicating that antioxidant therapy may have a potential effect in controlling allergic airway diseases. Recent studies showed that 5-aminoimidazole-4-carboxamide-1-beta-4-ribofuranoside (AICAR) has the potential ability to modulate NADPH oxidase activity, indicating the antioxidant activity of AICAR. This study investigated the inhibitory effects of AICAR as an anti-inflammatory modulator on allergic airway inflammation in murine animal models.

METHODS

The anti-inflammatory effects of AICAR were evaluated in two experimental asthma models: (1) an ovalbumin (OVA)-induced experimental asthma model and (2) an OVA plus polyinosinic-polycytidylic acid [poly (I:C)]-induced experimental asthma model to mimic respiratory viral infections. The inhibitory effects of AICAR in poly (I:C)-mediated signalling for NF-kappaB activation and production of TNF-alpha were analysed in vitro.

RESULTS

AICAR was shown to have a marginal inhibitory effect in an OVA-induced asthma model. Interestingly, AICAR significantly attenuated poly (I:C)-induced airway hyperresponsiveness and airway inflammation, as shown by the attenuation of the influx of total inflammatory cells and soluble products into bronchoalveolar lavage fluid, such as macrophages, eosinophils, IL-5, IL-13, TNF-alpha and IFN-gamma. AICAR also significantly reduced the serum levels of OVA-specific IgE and IgG2a antibodies. Histologic and flow cytometric studies showed that AICAR inhibited poly (I:C)-induced lung inflammation and the infiltration of CD11b+CD11c+ dendritic cells into the lung. Moreover, AICAR effectively inhibited poly (I:C)-mediated activation of NF-kappaB and the production of TNF-alpha.

CONCLUSION

These findings suggest that AICAR may be a novel immunomodulator with promising beneficial effects for the treatment of respiratory viral infection in airway allergic diseases.

Glucocorticoid receptor represses the Dex-mediated induction of human androgen response element-linked Luc activity

A human androgen response element (hARE), identified within intron 8 of the human sterol regulatory element-binding protein cleavage-activating protein, interacts with both glucocorticoid receptor (GR) and androgen receptors (AR). The aim of this study was to test the hypothesis that human GR (hGR) might modulate the expression of a hARE-linked reporter gene by dexamethasone (Dex). The hypothesis was tested by: a) co-transfecting HepG2 cells with a hGR and a luciferase (Luc)-reporter gene for performing in vitro investigations and b) by their co-injection into the tail vein of mice for in vivo investigation. In vitro co-transfected cells and the in vivo co-injected mice were then treated with Dex. Our results have led us to concluded that both transfection and injection of the hGR leads to a repression in the Dex-mediated induction of hARE-linked Luc activity both in vitro and in vivo settings. These findings suggest that this assay system allows screening of drug candidates affecting to a signal transduction pathway of the GR and AR and may help in the future discovery and analysis of novel and selection of GR and AR agonists.

Early engraftment kinetics of two units cord blood transplantation

Cord blood transplantation (CBT) is a promising alternative means of allogeneic stem cell transplantation. However, limited cell doses may compromise outcome. To enhance engraftment, CBT has been conducted using two units with promising results. However, little is known about the mechanism of engraftment. Here, we analyzed the early engraftment kinetics of eight patients given two unit umbilical CBT. Early engraftment kinetics revealed dominancy of one of two units from the day of engraftment (absolute neutrophil count > 0.5 x 10(9)/l). The median value of percentage of the predominant unit by chimerism analysis at the time of engraftment was 88% (60-100%). Two units CBT was found to be a safe, effective and promising alternative treatment option with good engraftment potential. Dominancy occurred early after CBT and is probably influenced by multiple factors.

Intussusception after gastric surgery

Intussusception following gastric surgery is a rare postoperative complication. It may develop in clinical situations following gastroenterostomy, Billroth II gastric surgery with or without Braun anastomosis, or Roux-en-Y gastrojejunostomy. The patients may present with either an acute surgical emergency or with a chronic, relapsing form. The mortality may be up to 50 % in these cases if not treated appropriately, but little is known about the mechanism underlying the condition. Early diagnosis with a high index of suspicion and prompt treatment of the acute form are therefore important. Surgical reduction with laparotomy is mandatory, although definitive corrective and preventative measures have not yet been established.

A steroid modulatory domain on NR2B controls N-methyl-D-aspartate receptor proton sensitivity

N-methyl-D-aspartate (NMDA) receptor function is modulated by several endogenous molecules, including zinc, polyamines, protons, and sulfated neurosteroids. Zinc, polyamines, and phenylethanolamines exert their respective modulatory effects by exacerbating or relieving tonic proton inhibition. Here, we report that pregnenolone sulfate (PS) uses a unique mechanism for enhancement of NMDA receptor function that is independent of the proton sensor. We identify a steroid modulatory domain, SMD1, on the NMDA receptor NR2B subunit that is critical for both PS enhancement and proton sensitivity. This domain includes the J/K helices in the S2 region of the glutamate recognition site and the fourth membrane transmembrane region (M4). A molecular model based on alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor structure suggests that steroid modulatory domain 1 contributes residues to a hydrophobic pocket that is capable of accommodating PS. The results demonstrate that the J/K helices and the fourth membrane transmembrane region participate in transducing allosteric interactions induced by steroid and proton binding to their respective sites.

Expression of FasL and perforin/granzyme B mRNA in chronic hepatitis B virus infection

Cytotoxic T lymphocytes are essential components of immune responses during chronic hepatitis B (CHB). It has been known that Fas ligand (FasL) and perforin/granzyme B-based mechanisms account for all T cell-mediated cytotoxicity. In the present work, we examined the correlation between injury of the hepatocytes and mRNA expression of FasL and perforin/granzyme B in liver tissue to investigate the roles of both the FasL and the perforin/granzyme B pathways in CHB. Reverse transcription-polymerase chain reaction was used to identify intrahepatic expression of FasL and perforin/granzyme B in liver biopsy specimens from 24 patients with hepatitis B virus (HBV) infection. In addition, the transferase-mediated deoxyuridine triphosphate nick end-labelling (TUNEL) method was used to determine the degree of apoptosis. The degree of mRNA expression and apoptosis were compared with the histologic activity index (HAI) and serology, including alanine aminotransferase (ALT). Intrahepatic mRNA expression rates of FasL, perforin and granzyme B were seen in 79.2, 62.5 and 33.3% of patients, respectively, and correlated with ALT levels (P < 0.05). Intrahepatic expression of FasL and perforin mRNA were significantly correlated with HAI (P < 0.05). Also, apoptosis documented by the TUNEL assay was correlated with HAI and intrahepatic mRNA expression of FasL and perforin (P < 0.05). Our results show that the T-cell mediated perforin death pathway as well as the Fas system play important roles in liver cell injury in HBV infection and that apoptosis mediated by the Fas/FasL system is closely correlated with HAI in chronic HBV infection.

Effects of Puerariae Flos and Puerariae Radix extracts on antioxidant enzymes in ethanol-treated rats

This study was performed to investigate the effect of Puerariae Flos (PF) and Puerariae Radix (PR) water extracts on the activities and mRNA expression of three hepatic antioxidant enzymes in ethanol-treated rats. Male Sprague-Dawley rats were divided into four groups, a control, ethanol-treated, ethanol plus PF-treated, and ethanol plus PR-treated group with seven rats per group. Ethanol (25 % v/v, 5 g/kg body weight) was orally administered once a day for 5 weeks. The PF and PR water extracts were supplemented in a diet based on 1.2 g of raw PF or PR/kg body weight/day. Ethanol administration without the PF or PR supplement significantly lowered the activities of hepatic Cu/Zn SOD and catalase (CAT), whereas it increased the hepatic GSH-Px activity. However, the PF and PR supplementation resulted in a significant increase in the Cu/Zn SOD and/or CAT activities and a significant decrease in the GSH-Px activity in the ethanol-treated rats. The mRNA levels of these antioxidant enzymes in the ethanol-treated rats were normalized to the control level by the PF or PR supplement. The hepatic glutathione content, which was significantly lower in the ethanol-treated group than in the control group, was also normalized to the control level by supplementing with either PF or PR. The PF or PR supplement resulted in lowering the hepatic malondialdehyde to the control level in the ethanol-treated rats.

Antioxidative activity of naringin and lovastatin in high cholesterol-fed rabbits

The consumption of a cholesterol-enriched diet increases the degree of lipid peroxidation, which is one of the early processes of atherosclerosis. The aim of this trial was to determine the antioxidative effects of the citrus bioflavonoid, naringin, a potent cholesterol-lowering agent, compared to the cholesterol-lowering drug, lovastatin, in rabbits fed a high cholesterol diet. Male rabbits were served a high-cholesterol (0.5%, w/w) diet or high-cholesterol diet supplemented with either naringin (0.5% cholesterol, 0.05% naringin, w/w) or lovastatin (0.5% cholesterol, 0.03% lovastatin, w/w) for 8 weeks to determine the plasma and hepatic lipid peroxide, plasma vitamin A and E levels, and hepatic hydrogen peroxide levels, along with the hepatic antioxidant enzyme activities and gene expressions. Only the lovastatin group showed significantly lower plasma and hepatic lipid peroxide levels compared to the control group. The naringin supplementation significantly increased the activities of both hepatic SOD and catalase by 33% and 20%, respectively, whereas the lovastatin supplementation only increased the catalase activity by 23% compared to control group. There was no difference in the GSH-Px activities between the various groups. Content of H2O2 in hepatic mitochondria was significantly lower in groups supplemented with lovastatin and naringin than in control group. However, there was no difference in cytosolic H2O2 content in liver between groups. The concentration of plasma vitamin E was significantly increased by the naringin supplementation. When comparing the antioxidant enzyme gene expression, the mRNA expression of SOD, catalase and GSH-Px was significantly up-regulated in the naringin-supplemented group. Accordingly, these results would appear to indicate that naringin, a citrus bioflavonoid, plays an important role in regulating antioxidative capacities by increasing the SOD and catalase activities, up-regulating the gene expressions of SOD, catalase, and GSH-Px, and protecting the plasma vitamin E. In contrast, lovastatin exhibited an inhibitory effect on the plasma and hepatic lipid peroxidation and increased the hepatic catalase activity in high-cholesterol fed rabbits.

Seroepidemiology of HBV infection in South Korea, 1995 through 1999

BACKGROUND

We analyzed serologic data that were obtained from the Korea Association of Health from 1995 to 1999 to estimate the reliable prevalence of HBV in South Korea.

METHODS

603,375, 639,465, 621,476, 612,705 and 650,398 serum samples were annually tested for HBsAg. Of HBsAg positive persons whose serum samples were available, HBeAg positivity was checked.

RESULTS

HBsAg positivities among subjects between 6 and 19 years old were 8.2%, 3.9%, 2.1%, 2.6% and 1.3%. HBsAg positivities among subjects above 20 years old were 8.9%, 6.4%, 5.9%, 5.4% and 5.4%. The positive rates of HBeAg were 39.8 to 62.9% among subjects between 6 and 19 years old, and 18.3 to 37.9% among persons above 20 years old, in each year. In both subgroups, HBsAg positivity in the latter year was significantly lower than that in the former year (p < 0.001). It also showed that HBsAg positivities among subjects between 6 and 19 years old have been significantly lower than those among subjects above 20 years old, but those of HBeAg the exact reverse of HBsAg since 1996 (p < 0.001).

CONCLUSIONS

It was observed that prevalence of HBV infection in the late 1990s, especially in the group between 6 and 19 years old, was conspicuously lower than that in the past. The nationwide vaccination programme might be one of the most important contributors to this tendency in Korea.

A curcuminoid and sesquiterpenes as inhibitors of macrophage TNF-alpha release from Curcuma zedoaria

Tumor necrosis factor-alpha (TNF-alpha) is one of the major mediators produced in activated macrophages which contribute to the circulatory failure associated with septic shock. In the course of screening marketed oriental anti-inflammatory herbal drugs for TNF-alpha antagonistic activity, a crude methanolic extract of the rhizomes of Curcuma zedoaria exhibited significant activity. The activity-guided fractionation and repetitive chromatographic procedures with the EtOAc-soluble fraction resulted in the isolation of three active compounds. They were identified as 1,7-bis(4-hydroxyphenyl)-1,4,6-heptatrien-3-one (1), procurcumenol (2) and epiprocurcumenol (3) by spectral data analysis. They inhibited the production of TNF-alpha by lipopolysaccharide (LPS)-activated macrophages from the results of bioassay (IC(50) values of 1 and 2 are 12.3 and 310.5 microM, respectively) and Western blot assay. These results imply that the traditional use of C. zedoaria rhizome as anti-inflammatory drug may be explained at least in part, by the inhibition of TNF-alpha production.

Ca2+/calmodulin-dependent protein kinase IV stimulates nuclear factor-kappa B transactivation via phosphorylation of the p65 subunit

Calmodulin-dependent protein kinase IV (CaMKIV) is a key mediator of Ca(2+)-induced gene expression. In this study, CaMKIV was found to directly associate with and phosphorylate the nuclear factor-kappaB (NFkappaB) component p65 both in vitro and in vivo. The phosphorylation of p65 by CaMKIV resulted in recruitment of transcription coactivator cAMP-response element-binding protein-binding protein and concomitant release of corepressor silencing mediator for retinoid and thyroid hormone receptors, as demonstrated by the glutathione S-transferase pull down and mammalian two hybrid assays. In addition, cotransfection of CaMKIV resulted in cytosolic translocation of the silencing mediator for retinoid and thyroid hormone receptors. Consistent with these results, cotransfected CaMKIV dramatically stimulated the NFkappaB transactivation in mammalian cells. From these results, NFkappaB is suggested to be a novel downstream effector molecule of CaMKIV.

Effect of solvent on the preparation of surfactant-free poly(DL-lactide-co-glycolide) nanoparticles and norfloxacin release characteristics

The surfactant-free nanoparticles of poly(DL-lactide-co-glycolide) (PLGA) were prepared by dialysis method without surfactant and physicochemical properties such as particle size and drug contents were investigated against used initial solvent. The size of PLGA nanoparticles and drug contents were significantly changed by used initial solvent. The size of PLGA nanoparticles prepared from dimethylacetamide (DMAc), dimethylformamide (DMF), and dimethylsulfoxide (DMSO) as a initial used solvent was smaller than that of acetone. Selected initial solvent used to dissolve the copolymer significantly affects the size of nanoparticles and drug contents. It was shown that PLGA nanoparticles have spherical shapes from the results of scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations. It was thought that surfactant-free nanoparticles of PLGA entrapping norfloxacin (NFX) has nice drug loading capacity without free-drug on the surface of nanoparticles through the analysis of X-ray powder diffraction. From these results, it was showed the potential that the PLGA nanoparticles could be formed successively by dialysis method without surfactant. Release kinetics of NFX used as a model drug was governed by not only drug contents but also particle size parameter. The higher the drug contents and the larger the particle size resulted in slower the drug release.

Regulation of ferritin light chain gene expression by oxidized low-density lipoproteins in human monocytic THP-1 cells

Genes induced or suppressed by oxidized low-density lipoproteins (oxLDL) in human monocytic THP-1 cells were searched using differential display reverse transcriptase polymerase chain reactions (DDRT-PCR). Among the many differentially expressed cDNA fragments, one was dramatically stimulated by the oxLDL in a steady state level, which was later found to contain sequences corresponding to ferritin light chain (L-ferritin) in a sequence homology search. The stimulatory effect of the oxLDL on the level of L-ferritin mRNA in the THP-1 cells was both time- and dose-dependent. When the cells were allowed to differentiate in the presence of phorbol 12-myristate 13-acetate (PMA), the differentiated cells were generally less responsive to the oxLDL than the undifferentiated ones. An increase of L-ferritin mRNA was observed when the cells were treated with the lipid components in the oxLDL such as 9-HODE, 13-HODE, and 25-hydroxycholesterol. In addition, a stimulation of the L-ferritin gene expression was also observed when the cells were treated with an endogenous peroxisome proliferator-activated receptor gamma (PPARgamma) ligand, 15d-PGJ2, in a time- and dose-dependent manner. These results suggest that oxLDL or its constituents are related to the stimulation of L-ferritin expression via PPARgamma.

A sesquiterpene, dehydrocostus lactone, inhibits the expression of inducible nitric oxide synthase and TNF-alpha in LPS-activated macrophages

Nitric oxide (NO) and tumor necrosis factor alpha (TNF-alpha) are the major mediators produced in activated macrophages which contribute to the circulatory failure associated with septic shock. A sesquiterpene lactone compound (dehydrocostus lactone) isolated from the medicinal plant, Saussurea lappa, inhibited the production of NO in lipopolysaccharide (LPS)-activated RAW 264.7 cells by suppressing inducible nitric oxide synthase enzyme expression. This compound also decreased the TNF-alpha level in LPS-activated systems in vitro and in vivo. Thus, dehydrocostus lactone may be a possible candidate for the development of new drugs to treat endotoxemia accompanied by the overproduction of NO and TNF-alpha.

Differentially expressed genes in cultured aortic smooth muscle cells by cholesterol-loading

Differentially expressed genes generated by cholesterol-loading in the culture medium of aortic smooth muscle cells (SMC) were screened using the DDRT-PCR technique in order to identify the genes that are possibly involved in the pathogenesis of atherosclerosis in the artery. Twenty-eight genes were initially isolated and three differentially expressed cDNAs were finally selected by Northern blot analysis. All three cDNAs were up-regulated (designated CRGSM-1 through -3) by the cholesterol-loading. Upon nucleotide sequencing and homology search in the databases, the first cDNA (CRGSM-1) had a high homology (97%) with the corresponding segment of the acyl-CoA synthetase II gene from rat brain, which participates in fatty acid synthesis. The second one (CRGSM-2) had a high homology (91%) with a part of Mus musculus (mouse) LIM protein 1, and with human skeletal muscle LIM-protein 1 genes (80%) and the third gene (CRGSM-3) had no significant homology match in the database. A full size cDNA isolated from the cDNA library of rat aortic smooth muscle cell using the CRGSM-2 as a probe was identified to have a high homology with muscle LIM protein (MLP). The isolated cDNA contained a segment of DNA that encodes for a zinc-finger motif and two LIM domains. Proteins bearing the LIM domain, defined as a unique double zinc-finger structure associated with a subclass of proteins involved in the determination of cell identity, cell differentiation and control of cell growth, have previously been suggested to play an important role in the pathogenesis of atherosclerosis by others.

Preparation of insulin-immobilized polyurethanes and their interaction with human fibroblasts

Insulin-immobilized polyurethanes (PU) were prepared by the graft polymerization of acrylic acid on oxygen plasma-treated PU, followed by a coupling reaction with polyethylene oxide (PEO) and subsequently with insulin. Modified PUs were characterized by measuring the water contact angle, the electron spectroscopy for chemical analysis and the attenuated total reflection Fourier-transform infrared spectroscopy. The wettabilities of the PU surfaces were increased by the introduction of acrylic acid, PEO and insulin. The amount of insulin immobilized was controlled by changing the concentrations of grafted acrylic acid and PEO. The interactions of human fibroblasts with surface-modified PUs were investigated using [3H]-thymidine incorporation and optical microscopy. Compared to the PU control, the proliferation of cells on the insulin-immobilized PUs was accelerated irrespective of the presence of serum while it was not influenced by PEO grafting. It seemed to be certain, from the experiments with high performance liquid chromatography, that A chain of insulin mainly reacted with the amine-end group of PEO grafted during the immobilization reaction.