Causality Assessment Between Drugs and Fatal Cerebral Haemorrhage Using Electronic Medical Records: Comparative Evaluation of Disease-Specific and Conventional Methods

INTRODUCTION

A new algorithm for causality assessment of drugs and fatal cerebral haemorrhage (ACAD-FCH) was published in 2021. However, its use in clinical practice has not been verified.

OBJECTIVES

This study aimed to explore the practical value of the ACAD-FCH when applying information available in clinical practice.

METHODS

The medical records of patients who died at the University of Tokyo Hospital in 2020 were reviewed, and cases with intracranial haemorrhage were selected. Two evaluators independently assessed these cases using three methods (the ACAD-FCH, Naranjo algorithm, and WHO-UMC scale). The number of 'Yes', 'No', and 'No information/Do not know' responses to each question by both evaluators were summed and compared. Inter-rater reliability was evaluated for each method using agreement rates and kappa coefficients with 95% confidence intervals (CI).

RESULTS

Among 316 deaths, 24 cases with intracranial haemorrhage were evaluated. The proportion of ‛No information/Do not know' responses for each question was 35.6% (95% CI 31.4-40.6%) for the ACAD-FCH and 66.9% (95% CI 62.5-71.1%) for the Naranjo algorithm. The respective agreement rates and kappa coefficients were 0.917 (0.798-1.00) and 0.867 (0.675-1.00) for the ACAD-FCH, 0.708 (0.512-0.904) and 0.139 (-0.236 to 0.513) for the Naranjo algorithm, and 0.50 (0.284-0.716) and 0.326 (0.110-0.541) for the WHO-UMC scale, respectively.

CONCLUSION

Our findings suggest the utility of the ACAD-FCH when assessing death cases with intracranial haemorrhage. However, larger studies including intra-rater assessments are warranted for further validation of this algorithm.

Antiviral effect and safety of nafamostat mesilate in patients with mild early-onset COVID-19: An exploratory multicentre randomized controlled clinical trial

OBJECTIVES

This study aimed to evaluate the antiviral effects and safety of nafamostat in early-onset patients with coronavirus disease 2019 (COVID-19).

METHODS

In this exploratory multicentre randomized controlled trial, patients were assigned to three groups within 5 days of symptom onset, with 10 participants in each group: nafamostat at either 0.2 mg/kg/h or 0.1 mg/kg/h or a standard-of-care group. The primary endpoint was area under the curve for decrease in SARS-CoV-2 viral load in nasopharyngeal samples from baseline to day 6.

RESULTS

Of the 30 randomized patients, 19 received nafamostat. Overall, 10 patients received low-dose nafamostat, 9 patients received high-dose nafamostat, and 10 received standard-of-care. The detected viruses were Omicron strains. The regression coefficient for area under the curve for decrease in viral load as the response variable and nafamostat dose per body weight as the explanatory variable showed a significant relationship of -40.1 (95% confidence interval, -74.1 to -6.2; P = 0.022). Serious adverse events were not observed in either group. Phlebitis occurred in ca. 50% of patients treated with nafamostat.

CONCLUSIONS

Nafamostat exerts virus load-reducing effects in patients with early-onset COVID-19.

High-dose ubiquinol supplementation in multiple-system atrophy: a multicentre, randomised, double-blinded, placebo-controlled phase 2 trial

Background

Functionally impaired variants of COQ2, encoding an enzyme in biosynthesis of coenzyme Q10 (CoQ10), were found in familial multiple system atrophy (MSA) and V393A in COQ2 is associated with sporadic MSA. Furthermore, reduced levels of CoQ10 have been demonstrated in MSA patients.

Methods

This study was a multicentre, randomised, double-blinded, placebo-controlled phase 2 trial. Patients with MSA were randomly assigned (1:1) to either ubiquinol (1500 mg/day) or placebo. The primary efficacy outcome was the change in the unified multiple system atrophy rating scale (UMSARS) part 2 at 48 weeks. Efficacy was assessed in all patients who completed at least one efficacy assessment (full analysis set). Safety analyses included patients who completed at least one dose of investigational drug. This trial is registered with UMIN-CTR (UMIN000031771), where the drug name of MSA-01 was used to designate ubiquinol.

Findings

Between June 26, 2018, and May 27, 2019, 139 patients were enrolled and randomly assigned to the ubiquinol group (n = 69) or the placebo group (n = 70). A total of 131 patients were included in the full analysis set (63 in the ubiquinol group; 68 in the placebo group). This study met the primary efficacy outcome (least square mean difference in UMSARS part 2 score (-1.7 [95% CI, -3.2 to -0.2]; P = 0.023)). The ubiquinol group also showed better secondary efficacy outcomes (Barthel index, Scale for the Assessment and Rating of Ataxia, and time required to walk 10 m). Rates of adverse events potentially related to the investigational drug were comparable between ubiquinol (n = 15 [23.8%]) and placebo (n = 21 [30.9%]).

Interpretation

High-dose ubiquinol was well-tolerated and led to a significantly smaller decline of UMSARS part 2 score compared with placebo.

Funding

Japan Agency for Medical Research and Development.

Multicenter, single-blind, randomized controlled study of the efficacy and safety of favipiravir and nafamostat mesilate in patients with COVID-19 pneumonia

OBJECTIVES

To evaluate the efficacy and safety of nafamostat combined with favipiravir for the treatment of COVID-19.

METHODS

We conducted a multicenter, randomized, single-blind, placebo-controlled, parallel assignment study in hospitalized patients with mild-to-moderate COVID-19 pneumonia. Patients were randomly assigned to receive favipiravir alone (n = 24) or nafamostat with favipiravir (n = 21). The outcomes included changes in the World Health Organization clinical progression scale score, time to improvement in body temperature, and improvement in oxygen saturation (SpO₂).

RESULTS

There was no significant difference in the changes in the clinical progression scale between nafamostat with favipiravir and favipiravir alone groups (median, -0.444 vs -0.150, respectively; least-squares mean difference, -0.294; P = 0.364). The time to improvement in body temperature was significantly shorter in the combination group (5.0 days; 95% confidence interval, 4.0-7.0) than in the favipiravir group (9.0 days; 95% confidence interval, 7.0-18.0; P =0.009). The changes in SpO₂ were greater in the combination group than in the favipiravir group (0.526% vs -1.304%, respectively; least-squares mean difference, 1.831; P = 0.022). No serious adverse events or deaths were reported, but phlebitis occurred in 57.1% of the patients in the combination group.

CONCLUSION

Although our study showed no differences in clinical progression, earlier defervescence, and recovery of SpO₂ were observed in the combination group.

A first-in-human study of the anti-inflammatory profibrinolytic TMS-007, an SMTP family triprenyl phenol

AIMS

TMS-007, an SMTP family member, modulates plasminogen conformation and enhances plasminogen-fibrin binding, leading to promotion of endogenous fibrinolysis. Its anti-inflammatory action, mediated by soluble epoxide hydrolase inhibition, may contribute to its efficacy. Evidence suggests that TMS-007 can effectively treat experimental thrombotic and embolic strokes with a wide time window, while reducing haemorrhagic transformation. We aim to evaluate the safety, pharmacokinetics and pharmacodynamics of TMS-007 in healthy volunteers.

METHODS

This was a randomized, placebo-controlled, double blind, dose-escalation study, administered as a single intravenous infusion of TMS-007 in cohorts of healthy male Japanese subjects. Six cohorts were planned, but only five were completed. In each cohort (n = 8), individuals were randomized to receive one of five doses of TMS-007 (3, 15, 60, 180 or 360 mg; n = 6) or placebo (n = 2).

RESULTS

TMS-007 was generally well tolerated, and no serious adverse events were attributed to the drug. A linear dose-dependency was observed for plasma TMS-007 levels. No symptoms of bleeding were observed on brain MRI analysis, and no bleeding-related responses were found on laboratory testing. The plasma levels of the coagulation factor fibrinogen and the anti-fibrinolysis factor α₂ -antiplasmin levels were unchanged after TMS-007 dosing. A slight increase in the plasma level of plasmin-α₂ -antiplasmin complex, an index of plasmin formation, was observed in the TMS-007 group in cohort 2.

CONCLUSIONS

TMS-007 is generally well tolerated and exhibits favourable pharmacokinetic profiles that warrant further clinical development.

Efficacy of l-Arginine treatment in patients with HTLV-1-associated neurological disease

OBJECTIVE

HTLV-1 infection causes HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), resulting in loss of motor function. In this Phase 2 trial, we assessed the efficacy and safety of l-arginine in patients with HAM/TSP.

METHODS

This open-label, single-arm, Phase 2 study enrolled patients diagnosed with HAM/TSP. Patients received l-arginine at a dose of 20 g orally for 1 week and were followed-up for 3 weeks. The primary endpoint was change in walking speed in the 10-m walk test (10MWT). The main secondary endpoints were change in Timed Up and Go Test (TUGT) time, improvement in inflammatory markers in cerebrospinal fluid (CSF), safety, and tolerability.

RESULTS

The study enrolled 20 patients (13 [65%] female) with a mean age of 67.8 years (95% CI 62.3 to 73.3). Although the primary endpoint, the changes in 10MWT time between baseline (Day 0) and Day 7, did not reach statistical significance (mean percent change in time -3.5%, 95% CI -10.8% to 3.7%; P = 0.32), a significant improvement was detected between baseline and Day 14 (-9.4%, 95% CI -16.6% to -2.2%; P = 0.01). Significant improvements were also observed in selected secondary endpoints, including in TUGT time (-9.1%, 95% CI -15.5% to -2.7%; P < 0.01), and in neopterin concentration in CSF (-2.1 pmol/mL, 95% CI -3.8 to -0.5; P = 0.01). Adverse events were infrequent, mild, and resolved rapidly.

INTERPRETATION

l-arginine therapy improved motor function and decreased CSF inflammatory markers. l-arginine thus represents a promising therapeutic option for patients with HAM/TSP.

TRIAL REGISTRATION NUMBER

UMIN000023854.

Ethnic differences in fat and muscle mass and their implication for interpretation of bioelectrical impedance vector analysis

According to the World Health Organization Expert Consultation, current body mass index (BMI) cut-offs should be retained as an international classification. However, there are ethnic differences in BMI-associated health risks that may be caused by differences in body fat or skeletal muscle mass and these may affect the interpretation of phase angle and bioelectrical impedance vector analysis (BIVA). Therefore, the aim of this study was to compare body composition measured by bioelectrical impedance analysis among 1048 German, 1026 Mexican, and 995 Japanese adults encompassing a wide range of ages and BMIs (18–78 years; BMI, 13.9–44.3 kg/m2). Regression analyses between body composition parameters and BMI were used to predict ethnic-specific reference values at the standard BMI cut-offs of 18.5, 25, and 30 kg/m2. German men and women had a higher fat-free mass per fat mass compared with Mexicans. Normal-weight Japanese were similar to Mexicans but approached the German phenotype with increasing BMI. The skeletal muscle index (SMI, kg/m2) was highest in Germans, whereas in BIVA, the Mexican group had the longest vector, and the Japanese group had the lowest phase angle and the highest extracellular/total body water ratio. Ethnic differences in regional partitioning of fat and muscle mass at the trunk and the extremities contribute to differences in BIVA and phase angle. In conclusion, not only the relationship between BMI and adiposity is ethnic specific; in addition, fat distribution, SMI, and muscle mass distribution vary at the same BMI. These results emphasize the need for ethnic-specific normal values in the diagnosis of obesity and sarcopenia.

Effect of short-term treatment with sitagliptin or glibenclamide on daily glucose fluctuation in drug-naïve Japanese patients with type 2 diabetes mellitus

AIMS

To compare the effect of a dipeptidyl peptidase-4 inhibitor (DPP4-i) and a sulfonylurea (SU) on daily glucose fluctuation in drug-naïve Japanese patients with type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

A total of 53 drug-naïve Japanese patients with T2DM (HbA1c, 7.0%-9.0%; fasting plasma glucose, 6.1 mmol/L or higher) were randomly assigned to either sitagliptin 50 mg qd or glibenclamide 2.5 mg per day (given in divided doses) in a 1:1 ratio. A continuous glucose monitoring (CGM) device was used to obtain 24-hour glucose profiles for each patient at baseline and at Week 2. The primary study endpoint was change from baseline in mean amplitude of glucose excursion (MAGE) during a 24-hour period. A key secondary endpoint was change from baseline in the standard deviation (SD) of 24-hour glucose levels.

RESULTS

After 2 weeks of treatment, a numerically greater reduction in MAGE from baseline was observed in the sitagliptin group compared with the glibenclamide group, but the between-treatment difference was not statistically significant (LS mean difference [95% CI]: -0.48 mmol/L [-1.31, 0.34]; P = .245). However, a significantly greater reduction in the change from baseline in SD was observed in the sitagliptin group compared with the glibenclamide group (LS mean difference [95% CI]: -0.33 mmol/L [-0.62, -0.03]; P = .029).

CONCLUSIONS

This study suggests that the DPP4 inhibitor sitagliptin has a greater ability to reduce daily glucose fluctuation than the SU glibenclamide in drug-naïve Japanese patients with T2DM. ClinicalTrials.gov: NCT02318693.

A Novel Method to Estimate Long-Term Chronological Changes From Fragmented Observations in Disease Progression

Clinical observations of patients with chronic diseases are often restricted in terms of duration. Therefore, obtaining a quantitative and comprehensive understanding of the chronology of chronic diseases is challenging, because of the inability to precisely estimate the patient's disease stage at the time point of observation. We developed a novel method to reconstitute long-term disease progression from temporally fragmented data by extending the nonlinear mixed-effects model to incorporate the estimation of "disease time" of each subject. Application of this method to sporadic Alzheimer's disease successfully depicted disease progression over 20 years. The covariate analysis revealed earlier onset of amyloid-β accumulation in male and female apolipoprotein E ε4 homozygotes, whereas disease progression was remarkably slower in female ε3 homozygotes compared with female ε4 carriers and males. Simulation of a clinical trial suggests patient recruitment using the information of precise disease time of each patient will decrease the sample size required for clinical trials.

Notable Drug-Drug Interaction Between Etizolam and Itraconazole in Poor Metabolizers of Cytochrome P450 2C19

In this study, impact of a polymorphism of CYP2C19 on drug-drug interaction (DDI) was examined for etizolam. The effect of itraconazole (a strong CYP3A inhibitor) on the pharmacokinetics of etizolam (a substrate of CYP2C19 and CYP3A) was assessed in both extensive metabolizers (EMs) and poor metabolizers (PMs) of CYP2C19. Sixteen participants (8 EMs and 8 PMs) received a single oral dose of etizolam (0.25 mg) on day 1. The participants ingested itraconazole (200 mg twice a day) on days 2-5. On day 5, participants received an oral dose of etizolam (0.25 mg) again. Before coadministration of itraconazole (day 1), the area under the time-plasma concentration curve from time zero to infinity (AUC_∞ ) of etizolam was higher in PMs than in EMs (2.65-fold, P < .01). Coadministration of itraconazole increased the AUC_∞ of etizolam 1.66-fold and 2.34-fold in EMs and PMs, respectively (day 5). Consequently, AUC_∞ was 6.18-fold higher in PMs with itraconazole than that in EMs without itraconazole. The increase by itraconazole was larger in PMs (P < .01). In heterozygous EMs (hEMs), AUC_∞ was simulated to be 2.56-fold higher with itraconazole than that in EMs without itraconazole. We found that in vitro measurements of fraction metabolized (f_m ) using the liver microsome prepared from PM donors would be helpful to predict polymorphism-dependent DDIs. These results suggest that the PMs and hEMs of a polymorphic CYP would be at higher risk of DDIs relative to EMs for drugs metabolized by both polymorphic and nonpolymorphic CYPs such as etizolam.

Accelerating Regulatory Science Initiatives for the Development of Drugs for Alzheimer's Disease in Japan

PURPOSE

The Ministry of Health, Labour and Welfare (MHLW) of Japan launched a regulatory science research project in which the aim is to promote the establishment of guidelines for the development of innovative drugs thorough interactions between academia and Japan's regulatory agency, the Pharmaceuticals and Medical Devices Agency (PMDA). In this project, a research system with the aim of developing a guideline for the clinical evaluation of drugs intended for the treatment of Alzheimer's disease (AD) was established.

METHODS

Two research groups were set up: (1) the Biomarker and Clinical Evaluation Group to establish biomarker-based criteria for the clinical evaluation of drugs for AD, and (2) the Modeling and Simulation (M&S) Group to create a disease model of AD using M&S techniques based on data from the Alzheimer's Disease Neuroimaging Initiative (ADNI). Furthermore, a human resource exchange between the University of Tokyo Hospital and the PMDA is conducted to establish a guideline that is suitable for regulatory use.

FINDINGS

As an interim report of this project, issues that require consideration for the clinical evaluation and development were summarized, including topics such as the use of biomarkers in the inclusion criteria, the efficacy endpoint, and the clinical data package required for application in Japan.

IMPLICATIONS

As the result of collaboration between the University of Tokyo Hospital and PMDA, this document is the first to summarize perspectives on the development of drugs for AD in Japan.

ERBB4 mutations that disrupt the neuregulin-ErbB4 pathway cause amyotrophic lateral sclerosis type 19

Amyotrophic lateral sclerosis (ALS) is a devastating neurological disorder characterized by the degeneration of motor neurons and typically results in death within 3-5 years from onset. Familial ALS (FALS) comprises 5%-10% of ALS cases, and the identification of genes associated with FALS is indispensable to elucidating the molecular pathogenesis. We identified a Japanese family affected by late-onset, autosomal-dominant ALS in which mutations in genes known to be associated with FALS were excluded. A whole- genome sequencing and parametric linkage analysis under the assumption of an autosomal-dominant mode of inheritance with incomplete penetrance revealed the mutation c.2780G>A (p. Arg927Gln) in ERBB4. An extensive mutational analysis revealed the same mutation in a Canadian individual with familial ALS and a de novo mutation, c.3823C>T (p. Arg1275Trp), in a Japanese simplex case. These amino acid substitutions involve amino acids highly conserved among species, are predicted as probably damaging, and are located within a tyrosine kinase domain (p. Arg927Gln) or a C-terminal domain (p. Arg1275Trp), both of which mediate essential functions of ErbB4 as a receptor tyrosine kinase. Functional analysis revealed that these mutations led to a reduced autophosphorylation of ErbB4 upon neuregulin-1 (NRG-1) stimulation. Clinical presentations of the individuals with mutations were characterized by the involvement of both upper and lower motor neurons, a lack of obvious cognitive dysfunction, and relatively slow progression. This study indicates that disruption of the neuregulin-ErbB4 pathway is involved in the pathogenesis of ALS and potentially paves the way for the development of innovative therapeutic strategies such using NRGs or their agonists to upregulate ErbB4 functions.

Evaluating the driving ability in patients with Parkinson's disease using a driving simulator

OBJECTIVE

For patients with Parkinson's disease (PD), driving is challenging due to an impaired motor function and decreased attention capabilities. This study assessed the driving capacity in PD patients by comparing neurological signs.

METHODS

The driving ability of PD patients was evaluated using a driving simulator (Safety Master NT-932) that tested the reaction time in response to traffic signals and steering wheel errors. We studied the correlations between the total Unified Parkinson's Disease Rating Scale (UPDRS) score, the UPDRS part III score, the subscores of the UPDRS part III score, age, PD disease duration, braking reaction time, steering wheel errors and total scores for driving safety test results. 'On' state regular PD licensed drivers (n=42; mean age: 63 years) in Hoehn and Yahr stages II-III participated after their cognitive status was confirmed using mini-mental state examinations.

RESULTS

The UPDRS scores, the UPDRS part III scores and the postural instability subscores exhibited significant (p<0.05) correlations with the number of steering wheel errors but not with the braking reaction time or the total safety scores of the test results.

CONCLUSION

The UPDRS is an established evaluation method used to estimate PD signs, although it is not sufficient alone for deciding whether PD patients should be allowed to drive. Our findings suggest that determining the driving ability using a driving simulator might be a useful adjunct to UPDRS scores in the assessment of PD patients who are active drivers. Estimating the driving ability requires complex measurements, including motor performance with perception of stimuli and attention.

View and present status of personnel involved in clinical trials: a survey of participants from the First Symposium of the Shikoku Collaborative Group for Promotion of Clinical Trials

Clinical trials leading to drug approval (registration trials) play a central role in the drug development process. Since the introduction of the Good Clinical Practice (GCP) standard in 1997, the Japanese infrastructure for registration trials has improved. The contribution of support staff, including clinical research coordinators (CRCs), to clinical trials is now widely recognized in Japan. Quality issues and career development for these support staff are being increasingly emphasized. The Shikoku Collaborative Group for Promotion of Clinical Trials was organized in 2008 to address these issues through communication with the personnel involved in clinical trials in regional areas of Japan. To understand the views and present status of personnel involved in clinical trials, we used questionnaires to survey the participants of the First Symposium of the Shikoku Collaborative Group for Promotion of Clinical Trials held in August 2009. Group discussions and special lectures occurred at the symposium. The questionnaire began with questions about basic patient characteristics, followed by practical questions. Of 110 participants, there were 68 respondents (62%), including clinical trial support staff (clinical research coordinators [n=36, 53%], administrative officers [n=9, 13%]), and medical staff [n=23, 34%]). Among the support staff, 36 (80%) had more than 5 years of experience. The most common questionnaire answer selected for participation in the symposium was "willing to contact staff from other medical institutions or organizations" for support staff and "to obtain further knowledge concerning clinical trials" for medical staff. The overall view of the discussion ("Was the discussion satisfactory?") was favorable for 36 (53%) respondents. This survey revealed that the group discussion in the present symposium appears to be valuable for participants, using overall satisfaction as a surrogate. Based on the information obtained in the present study, further development of the clinical trial infrastructure, including training opportunities and career development for support staff, is required. Due to the limitations of this study, further analysis is warranted to determine the optimal strategy for training support staff.

Plasma amantadine concentrations in patients with Parkinson's disease

We determined plasma amantadine concentrations in patients with Parkinson's disease (PD) in daily clinical practice and investigated the relationship between plasma concentration and adverse reactions to clarify the safe therapeutic range. Seventy-eight consecutive PD patients on stable amantadine treatment were recruited. Plasma concentration of amantadine was measured 3h after the administration of morning amantadine dose. Serum creatinine was measured to estimate renal function. The mean daily dose of amantadine was 135.1+/-62.3mg/day, and the mean plasma amantadine concentration was 812.5+/-839.5 ng/ml (range, 91-4400 ng/ml). Plasma amantadine concentration increased according to increasing renal dysfunction. Three patients exhibited adverse reactions, such as myoclonus, hallucinations, and delirium, and all of them showed plasma amantadine concentration >3000 ng/ml. None of the three cases had previously shown such side effects. PD patients who have not developed any psychiatric symptoms as adverse reactions to the treatment may develop myoclonus, hallucination, or delirium when the plasma concentration of amantadine exceeds 3000 ng/ml. It is therefore recommended to use amantadine at the plasma concentration of less than 3000 ng/ml in the treatment of Parkinson's disease, especially in elderly patients.

Expression of proinflammatory cytokines and its relationship with virus infection in the brain of macaques inoculated with macrophage-tropic simian immunodeficiency virus

The pathogenesis of acquired immunodeficiency syndrome dementia complex (ADC) is still poorly understood. Many studies suggest that proinflammatory cytokines such as IL-1beta and TNF-alpha released by microglia/macrophages or astrocytes play a role in CNS injury. A microscopic finding of a microglial nodule with multinucleated giant cells (MNGCs) is a histopathologic hallmark of ADC and named HIV encephalitis. However, in vivo expression of these cytokines in this microenvironment of HIV encephalitis is not yet clarified. One of the main reasons is complexities of brain pathology in patients who have died from terminal AIDS. In this study, we infected two macaques with macrophage-tropic Simian immunodeficiency virus SIV239env/MERT and examined expression of TNF-alpha and IL-1beta in inflammatory lesions with MNGCs and its relation to virus-infected cells using immunohistochemistry. One macaque showed typical inflammatory lesions with MNGCs in the frontal white matter. Small microglial nodules were also detected in the basal ganglia and the spinal cord. SIVenv positive cells were detected mainly in inflammatory lesions, and seemed to be microglia/macrophages and MNGCs based on their morphology. Expression of IL-1beta and TNF-alpha were detected in the inflammatory lesions with MNGCs, and these positive cells were found to be negative for SIVenv by double-labeling immunohistochemistry or immunohistochemistry of serial sections. There were a few TNF-alpha positive cells and almost no IL-1beta positive cells in the area other than inflammatory lesions. Another macaque showed scattered CD3+ cells and CD68+ cells in the perivascular regions of the white matter. SIVenv and TNF-alpha was demonstrated in a few perivascular macrophages. These findings indicate that virus-infected microglia/macrophages do not always express IL-1beta and TNF-alpha, which suggests an indirect role of HIV-1-infected cells in cytokine-mediated pathogenesis of ADC. Our macaque model for human ADC may be useful for better understanding of its pathogenesis.

Effect of clarithromycin on the pharmacokinetics of cabergoline in healthy controls and in patients with Parkinson's disease

Cabergoline is used in the treatment of Parkinson's disease (PD). Clarithromycin is a potent inhibitor of CYP3A4 and P-glycoprotein and is often co-administered with cabergoline in usual clinical practice. We studied the effect of clarithromycin co-administration on the blood concentration of cabergoline in healthy male volunteers and in PD patients. Study 1: Ten healthy male volunteers were enrolled and were randomized to take a single oral dose of cabergoline (1 mg/day) for 6 days or a single oral dose of cabergoline plus clarithromycin (400 mg/day) for 6 days. Study 2: Seven PD patients receiving stable cabergoline doses were enrolled. They were evaluated for the plasma cabergoline concentration before and after the addition of clarithromycin 400 mg/day for 6 days, and again 1 month after discontinuation of clarithromycin. The dose and duration of clarithromycin were decided according to usual clinical practice. In healthy male volunteers, mean Cmax and AUC(0-10 h) of cabergoline increased to a similar degree during co-administration of clarithromycin. Mean plasma cabergoline concentration over 10 h post-dosing increased 2.6-fold with clarithromycin co-administration. In PD patients, plasma cabergoline concentration increased 1.7-fold during clarithromycin co-administration. Co-administration with clarithromycin may increase the blood concentration of cabergoline in healthy volunteers and in PD patients.

[Inter- and intraindividual pharmacokinetic variations in the treatment of Parkinson's disease]

In the treatment of Parkinson's disease, levodopa, DCI, MAO-B inhibitor, COMT inhibitors, dopamine receptor agonists, amantadine, anticholinergics have been applied and new drugs are being developed. Levodopa is still the golden standard in the treatment of Parkinson's disease. The study on levodopa bioavailability showed 3-4 times differences in individual patients. Drug-food interactions are prominent in levodopa. Low protein food increased levodopa bioavailability and improved no ON or delayed ON in the treatment of Parkinson's disease. Vitamine C or magnesium did not alter the bioavailability of levodopa. The bioavailability of levodopa between the levodopa/carbidioa (100/12.5) group and the levodopa/benserazide (100/25) group was studied in patients with Parkinson's disease by population PK study. C(max) of levodopa in levodeopa/benserazide group was twice as high as in levodopa/carbidopa group. Domperidone, a dopamine receptor antagonist applied as an antiemetic inceases vowel movement. The effect of domperidone on levodopa bioavailability was studied, and the combination of domperidone with levodopa increased AUC of levodopa. Clarythromycin or grape fruit juice inhibits both of CYP3A4 and P-glycoprotein which work on metabolism and absorption of drugs. Coadministration of clarythromycin with ergot alkaloids such as cabergoline or bromocriptine increased the AUC up to 2-3 times. Amantadine is excreted through kidney without being metabolized and renal function is the most important factor in the blood concentration of amantadine. In elder women with the body weight of 50 kg or less, creatinine clearance is less than 50 ml/min even though the serum creatinine is within the normal range. Selegiline is metabolized through CYP2D6 and 3A4. Coadministration of qunidine, cimetidine, maclorides, antifungals, grape fruit juice increase the bioavailability of selegiline and may augment the antiparkinsonian effect.

Simian immunodeficiency virus encephalitis in the white matter and degeneration of the cerebral cortex occur independently in simian immunodeficiency virus-infected monkey

Highly active antiretroviral therapy (HAART) has been successful to reduce progression of acquired immunodeficiency syndrome (AIDS). Nevertheless, recent autopsy analysis of the brain from patients with human immunodeficiency virus (HIV)-1 infection reported same or even increasing numbers of AIDS encephalopathy. This insufficient effect of HAART for central nervous system (CNS) complication might be explained by independent pathogenetic processes in lymph node and CNS. We inoculated macaques with three Simian immunodeficiency virus (SIV) strains and investigated relationship between degree of the lymph node pathology and that of AIDS-related brain pathology. Animals infected with T-cell-tropic viruses SIVmac239 and SHIV-RT developed typical AIDS pathology in the lymph node 46 to 156 weeks after infection. The cerebral cortex of these animals showed focal or diffuse gliosis, and electron microscopic analysis demonstrated degenerative changes, such as accumulation of dense lamellar bodies in the dendrites and swelling of astrocytic processes. However, there was no evidence of microglial nodules or multinucleated giant cells in the white mater. The animals infected with macrophage-tropic SIV239env/MERT did not develop lymph node pathology of AIDS in the same or longer period of infection. The white mater of the animal, however, showed microglial nodules with multinucleated giant cells, a pathological hallmark of AIDS encephalopathy. SIV immunoreactivity was demonstrated in these giant cells as well as macrophage/microglia cells. On the other hand, there was no abnormality in the cerebral cortex. These findings suggest that there are two independent pathogenetic processes in AIDS encephalopathy: immune response against virus infected macrophage/microglial cells in the white mater without immunodeficiency and cortical degeneration caused in the late stage of AIDS.

nef gene is required for robust productive infection by simian immunodeficiency virus of T-cell-rich paracortex in lymph nodes

The pathogenesis of AIDS virus infection in a nonhuman primate AIDS model was studied by comparing plasma viral loads, CD4(+) T-cell subpopulations in peripheral blood mononuclear cells, and simian immunodeficiency virus (SIV) infection in lymph nodes for rhesus macaques infected with a pathogenic molecularly cloned SIVmac239 strain and those infected with its nef deletion mutant (Deltanef). In agreement with many reports, whereas SIVmac239 infection induced AIDS and depletion of memory CD4(+) T cells in 2 to 3 years postinfection (p.i.), Deltanef infection did not induce any manifestation associated with AIDS up to 6.5 years p.i. To explore the difference in SIV infection in lymphoid tissues, we biopsied lymph nodes at 2, 8, 72, and 82 weeks p.i. and analyzed them by pathological techniques. Maximal numbers of SIV-infected cells (SIV Gag(+), Env(+), and RNA(+)) were detected at 2 weeks p.i. in both the SIVmac239-infected animals and the Deltanef-infected animals. In the SIVmac239-infected animals, most of the infected cells were localized in the T-cell-rich paracortex, whereas in the Deltanef-infected animals, most were localized in B-cell-rich follicles and in the border region between the paracortex and the follicles. Analyses by double staining of CD68(+) macrophages and SIV Gag(+) cells and by double staining of CD3(+) T cells and SIV Env(+) cells revealed that SIV-infected cells were identified as CD4(+) T cells in either the SIVmac239 or the Deltanef infection. Whereas the many functions of Nef protein were reported from in vitro studies, our finding of SIVmac239 replication in the T-cell-rich paracortex in the lymph nodes supports the reported roles of Nef protein in T-cell activation and enhancement of viral infectivity. Furthermore, the abundance of SIVmac239 infection and the paucity of Deltanef infection in the T-cell-rich paracortex accounted for the differences in viral replication and pathogenicity between SIVmac239 and the Deltanef mutant. Thus, our in vivo study indicated that the nef gene enhances SIV replication by robust productive infection in memory CD4(+) T cells in the T-cell-rich region in lymphoid tissues.

Limited intercellular spread of spontaneous Ca2+ signals via gap junctions between mouse chromaffin cells in situ

Using a confocal laser-scanning microscope, we measured the changes in the cytosolic Ca(2+) concentration ([Ca]i) of chromaffin cells on adrenal slice preparations of mouse. The spontaneous fluctuations of [Ca]i were often observed in situ, as reported in isolated rat and bovine cells. Intriguingly, the spontaneous [Ca]i changes in one cell were often transmitted to one or two adjacent cells, and the synchronized [Ca]i changes were often observed in two adjacent cells, both of which failed to respond to ATP. The synchronized [Ca]i changes between two cells were much less frequently observed in rat than in mouse adrenals. The spontaneous [Ca]i changes were also synchronized between closely touching mouse chromaffin cells in culture. These results suggest that the spread of Ca(2+) signaling is mediated by low-conductance intercellular coupling.

Excitatory effect of ATP on acutely dissociated ventromedial hypothalamic neurons of the rat

The ATP-induced increase in the cytosolic Ca(2+) concentration ([Ca]i) and current in acutely dissociated ventromedial hypothalamic rats neurons were investigated using fura-2 microfluorometry and the nystatin-perforated patch recording method, respectively. The ATP-induced [Ca]i increase was mimicked by dimethyl-thio-ATP and ATPgammaS, and was inhibited by P2 purinoreceptor antagonists. The ATP-induced [Ca]i increase was markedly reduced by removal of external Na(+) or Ca(2+), and by addition of various Ca(2+) channel antagonists. ATP induced a transient inward current exhibiting a strong inward rectification at membrane potentials more positive than -20 mV. The ATP-induced current at a holding potential of -70 mV was concentration-dependent with a half-maximum effective concentration of 26 microM. Increasing the external Ca(2+) concentration to 10 mM shifted the dose-response relationship to the right. ATP induced only a small current and a small increase in [Ca]i, even at 10 mM Ca(2+), when external Na(+) was removed, suggesting the relatively low permeability to Ca(2+) of purinoceptor channels. These results suggest that ATP activates non-selective cation channels by acting on P2X purinoceptors on dissociated ventromedial hypothalamic neurons, which in turn increases [Ca]i by increasing Ca(2+) influx through voltage-dependent Ca(2+) channels.

Intraventricular administration of the neurotrophic factor midkine ameliorates hippocampal delayed neuronal death following transient forebrain ischemia in gerbils

Midkine (MK) is a growth factor with neurotrophic activities, and is expressed during the early stages of experimental cerebral infarction in rats in the zone surrounding the infarct. To evaluate in vivo activity of MK in preventing neuronal death, MK produced in yeast (Pichia pastoris) was administered into the brain ventricle immediately before occlusion of the bilateral common carotid artery of Mongolian gerbils. MK administration at the dose of 0.5-2 microg immediately before occlusion was found to ameliorate delayed neuronal death in the hippocampal CA1 region caused by transient ischemia 7 days after the insult. The hippocampal neurons of the MK-administered gerbils tended to degenerate 14 and 21 days after the insult, but their numbers remained higher than those in saline-administered controls; however, the hippocampal neurons were degenerated 28 days after the insult. MK administration at 2 h after occlusion did not ameliorate the neuronal death. These findings suggested that the therapeutic time window was narrow. The two to four times repeated administration of 2 microg MK immediately before and at 1, 2, or 3 weeks after the occlusion were not significantly different for the hippocampal neuronal death at 28 days after the insult compared with a single injection, but were significantly effective compared with vehicle administration alone. These findings suggested that the therapeutic time window was relatively narrow. The potent neuroprotective activity of MK observed in vivo suggested that MK might be useful as a therapeutic reagent for prevention of neuronal death in neurodegenerative diseases.

Phenotypes of X-linked Charcot-Marie-Tooth disease and altered trafficking of mutant connexin 32 (GJB1)

To clarify the pathomechanism in three patients with X-linked Charcot-Marie-Tooth disease (CMTX) and unique clinical features, we studied three connexin (Cx) 32 (GJB1) mutants with respect to cellular localization in cultured cells. Wild-type Cx32 and three Cx32 mutants (Va163Ile and Glu186Lys, obtained from CMTX patients with hearing impairment; and Arg22Gln, obtained from a CMTX patient with a fair number of onion-bulb formations) were transfected to rat pheochromocytoma cells (PC12). We investigated the expression of Cx32 protein in each clone by immunoblotting and immunohistochemical staining. While Cx32 protein with the Arg22Gln mutation was detectable immunohistochemically only in the cytoplasm, Cx32 protein with the Va163Ile or Glu186Lys mutation was detected in both the plasma membrane and the cytoplasm. Cx32 protein with the wild-type sequence was detected mostly in the plasma membrane, with plaques indicating the existence of active gap junction formation. These three Cx32 mutations associated with CMTX patients with unique clinical and pathological findings caused altered trafficking of the Cx32 protein. These altered expressions indicated loss of active gap junction formation with different expression abnormalities in these CMTX patients.

HTLV-I-associated myelopathy (HAM)/tropical spastic paraparesis (TSP) with amyotrophic lateral sclerosis-like manifestations

To clarify the existence of HAM/TSP presenting amyotrophic lateral sclerosis (ALS)-like manifestations, we assayed HTLV-I proviral load in peripheral blood mononuclear cells (PBMC) in 15 patients with anti-HTLV-I antibody in serum and ALS-like manifestations (upper motor neuron involvement in at least one region and lower motor neuron involvement in at least two limbs) by quantitative PCR, and compared the proviral load with that of 233 HAM/TSP patients and of 213 HTLV-I carriers. Five of 15 patients with ALS-like manifestations had proviral loads as high as those in the 233 patients with HAM/TSP. Anti-HTLV-I antibody in cerebrospinal fluid (CSF) was present in all of five patients. The proviral load in the remaining 10 patients was similar to that in HTLV-I carriers. Four of five patients with a high proviral load met the diagnostic criterion of HAM/TSP except for lower motor neuron involvement. These four patients showed high neopterin levels in CSF. On the basis of HTLV-I proviral load in PBMC and the clinical symptoms, our tentative conclusion is that these four patients are HAM/TSP presenting ALS-like manifestations.

Activation of ATP receptor increases the cytosolic Ca(2+) concentration in nucleus accumbens neurons of rat brain

ATP increased the cytosolic Ca(2+) concentration ([Ca](i)) in nucleus accumbens neurons acutely dissociated from rat brain. The ATP response was dependent on external Ca(2+) and Na(+), and was blocked by voltage-dependent Ca(2+) channel blockers. The results suggest that the ATP-induced depolarization increases Ca(2+) influx resulting in the increase in [Ca](i).

Histopathological analysis of four autopsy cases of HTLV-I-associated myelopathy/tropical spastic paraparesis: inflammatory changes occur simultaneously in the entire central nervous system

Although brain lesions have been described in some cases with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP), little is known about the nature of brain lesion and its relation to the spinal cord lesion. In the present study, we performed histopathological analysis of the brain and the spinal cord of four autopsied cases with HAM/TSP to clarify the relationship between the brain and the spinal cord lesions. In two cases with active-chronic inflammation in the spinal cord, perivascular inflammatory infiltration was also seen in the brain, and the composition of cell subsets was similar both in the spinal cord and in the brain. No active inflammatory change was seen in the brain in two cases with inactive-chronic spinal cord lesions. Inflamed vessels were distributed mainly in the deep white matter and in the area between cerebral cortex and white matter of the brain. In the spinal cord inflamed vessels were mainly seen in the bilateral lateral and the ventral posterior columns. Parenchymal infiltration was diffused in the spinal cord but very sparse in the brain, suggesting the importance of parenchymal infiltration in the destruction of tissues. These results suggest that inflammatory changes occurred simultaneously in the spinal cord and in the brain, and that distribution of inflamed vessels closely correlated with the characteristics of vascular architecture of the brain and the spinal cord, which lead to a slow blood flow. This study may help promote a better understanding of the pathogenesis of HAM/TSP.

Molecular pathologic analysis of the tonsil in HTLV-I-infected individuals

Little is known about the role of the tonsils in HTLV-I infection. We performed molecular pathologic studies of tonsils in individuals positive or negative for anti-HTLV-I antibodies (HTLV-I-Ab) to clarify histologic characteristics of tonsils in HTLV-I infection. We collected tonsils and peripheral blood samples from patients who underwent tonsillectomy in a prospective manner. HTLV-I-Ab in serum was examined and presence of HTLV-I provirus was detected by polymerase chain reaction (PCR) in extracted DNA of both peripheral blood and tonsils. Histopathologic and immunohistochemical evaluations of tonsils were performed. HTLV-I seropositivity and PCR detection of HTLV-I provirus matched perfectly. Tonsil samples from seropositive individuals showed atrophy of the mantle zone and high numbers of T cells in the marginal zone compared with findings in HTLV-I-negative samples. HTLV-I provirus could be detected only from extracted DNA of extrafollicular areas. PCR in situ hybridization also showed positive signals in some mononuclear cells located in the marginal zone. There was a significant correlation between HTLV-I proviral load in tonsils and in peripheral blood. These results suggest the presence of characteristic histologic changes and deviated localization of HTLV-I-infected cells in the tonsils of individuals positive for HTLV-I.

Detection of human T-lymphotropic virus type I p40tax protein in cerebrospinal fluid cells from patients with human T-lymphotropic virus type I-associated myelopathy/tropical spastic paraparesis

We investigated the role of viral transcripts of human T-lymphotropic virus type I (HTLV-I) in the cerebrospinal fluid (CSF) cells and peripheral blood mononuclear cells (PBMCs) of patients with human T-lymphotropic virus type I-associated myelopathy (HAM)/tropical spastic paraparesis (TSP). To detect the HTLV-I p40tax protein, we developed a new sensitive method of immunohistochemistry combined with tyramide signal amplification and quantitative analysis. Seven patients with HAM/TSP were examined. As controls, four patients with other neurological diseases were examined; two of these patients were infected with HTLV-I and the other two were not. Both the CSF cells and PBMCs were reacted with a monoclonal antibody, Lt-4, for p40tax protein, followed by secondary antibody labeled with horseradish peroxidase. This was visualized by fluorescein directly labeled with tyramide and the number of positive cells was quantified with a Laser Scanning Cytometer. In the samples from patients with HAM/TSP, the HTLV-I p40tax protein was successfully detected by tyramide signal amplification, but not without it. In HAM/TSP patients, 0.04-1.16% of the CSF cells and 0.02-0.54% of PBMCs were positive for the HTLV-I p40tax protein, respectively. The expression of the HTLV-I p40tax protein in the CSF cells was more frequent than that in PBMCs in both HAM/TSP patients and HTLV-I carriers, and was also more frequent in the patients with HAM/TSP of shorter duration of illness. This technique could be a powerful tool to investigate the pathogenic mechanism of diseases associated with HTLV-I.

Activation of macrophages/microglia with the calcium-binding proteins MRP14 and MRP8 is related to the lesional activities in the spinal cord of HTLV-I associated myelopathy

Macrophages and microglia may play an important role in the pathogenesis of chronic inflammatory process in HTLV-I associated myelopathy (HAM) and tropical spastic paraparesis (TSP). However, the etiology and cellular mechanism of chronic inflammation are poorly understood in HAM/TSP. To help to define the roles of macrophages and microglia we analyzed the various patterns of macrophage and microglia activation in the central nervous system (CNS) of HAM/TSP using several monoclonal antibodies recognizing the different states of activation. The results indicate that a large number of macrophages and microglia express both MRP14 and MRP8 in active-chronic inflammatory lesions of the patients with a short duration of illness (2.5 years). In the patient whose duration of illness was 4.5 years, perivascular and parenchymal macrophages and microglia were reactive for MRP8 but not for MRP14. In contrast, MRP14 and MRP8 were negative on the perivascular and parenchymal macrophages and microglia in inactive-chronic lesions and in controls. This study suggests that (a) activated macrophages and microglia as well as CD4+ T lymphocytes and CD8+ cytotoxic T lymphocytes are main components of the inflammatory process in the CNS in HAM/TSP, (b) activation of macrophages and microglia is related to the amount of HTLV-I proviral DNA in situ.

A rat model of human T lymphocyte virus type I (HTLV-I) infection: in situ detection of HTLV-I provirus DNA in microglia/macrophages in affected spinal cords of rats with HTLV-I-induced chronic progressive myeloneuropathy

To investigate the pathogenetic role of human T lymphocyte virus type I (HTLV-I) in central nervous system disease, a rat model for HTLV-I-associated myelopathy/tropical spastic paraparesis, designated as HAM rat disease, has been established. Wistar-King-Aptekman-Hokudai strain rats with induced HTLV-I infection develop a chronic progressive myeloneuropathy with paraparesis of hind limbs after an incubation period of 15 months. In the affected spinal cord in these rats, white matter degeneration, demyelination and vacuolar change with microglia/macrophage infiltration are present as are the provirus DNA and the virus mRNA. To identify infected cells in the affected lesions, we carried out in situ hybridization of amplified fragments of the provirus DNA by polymerase chain reaction on thin sections, plus immunohistochemistry on the same sections. The provirus DNA was localized in some microglia/macrophages in the spinal cord lesion. In addition, the HTLV-I provirus was clearly evident not only in ED-1-negative lymphoid cells but also in ED-1-positive macrophages from lymph nodes. These observations suggest that cells of microglia/macrophage lineage may be one of dominant viral reservoirs in the spinal cords and lymph nodes in HAM rat disease. These infected microglia/macrophages may relate to cause the myeloneuropathy through neurotoxic cytokine synthesis.

Analysis of HTLV-I proviral load in 202 HAM/TSP patients and 243 asymptomatic HTLV-I carriers: high proviral load strongly predisposes to HAM/TSP

In order to examine the effect of HTLV-I proviral load on the pathogenesis of HAM/TSP, we measured the HTLV-I proviral load in peripheral blood mononuclear cells (PBMC) from a large number of HAM/TSP patients and asymptomatic HTLV-I carriers. To measure the proviral load, we used an accurate and reproducible quantitative PCR method using a dual-labeled fluorogenic probe (ABI PRISM 7700 Sequence Detection System). The mean +/- standard error of mean (s.e.m.) HTLV-I proviral copy number per 1 x 10(4) PBMC was 798 +/- 51 (median 544) in 202 HAM/TSP patients; 120 +/- 17 (median 34) in 200 non HAM-related (general) asymptomatic HTLV-I carriers (RC); and 496 +/- 82 (median 321) in 43 asymptomatic HTLV-I carriers genetically related to HAM/TSP patients (FA). The prevalence of HAM/TSP rises exponentially with log (proviral load) once the proviral load exceeds 1% PBMC. The HTLV-I proviral load of female patients with HAM/TSP was significantly higher than that of male patients, however there was no significant difference in proviral load between sexes in RC. There was a significant correlation between the proviral load and the concentration of neopterin in CSF of HAM/TSP patients. These results indicate that the HTLV-I proviral load in PBMC may be related to the inflammatory process in the spinal cord lesion. The increased proviral load in FA suggests the existence of genetic factors contributing to the replication of HTLV-I in vivo.

Genetic diagnostic test of hepatocellular carcinoma by telomerase catalytic subunit mRNA

This study investigated the relationship between telomerase activity and telomere length and between telomerase reverse transcriptase (hTERT) mRNA and telomere length. Both cancerous and non-cancerous tissues were studied in individuals with hepatic carcinoma. In this study, the telomere length in HCC livers had a wide range, no clear significant correlation was found between hTERT mRNA and telomere length. Telomerase activity was more strongly correlated with hTERT mRNA than with telomere length. The correlation between hTERT mRNA and telomerase activity shown here indicates that hTERT mRNA has potential for cancer diagnosis.

Perivascular T cells are infected with HTLV-I in the spinal cord lesions with HTLV-I-associated myelopathy/tropical spastic paraparesis: double staining of immunohistochemistry and polymerase chain reaction in situ hybridization

HTLV-I-infected cells play an important role in pathogenesis HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Our previous studies of quantitative polymerase chain reaction (PCR) and in situ PCR suggested that T cells infiltrating in the spinal cord lesion were infected with HTLV-I. To elucidate the localization of HTLV-I proviral DNA directly, we performed double staining using immunohistochemistry and PCR in situ hybridization (PCR-ISH). Fresh frozen sections of the spinal cord from four HAM patients taken at autopsy were first immunostained with antibodies to pan T cells (UCHL-1), macrophages (KP-1) and helper/inducer T cells (OPD4). Then PCR-ISH was carried out with specific primers and probe for the HTLV-I pX region. UCHL-1-positive cells were noted around perivascular areas and, to some extent, in the parenchyma. Of the UCHL-1-positive cells, 9.4% (case 1), 9.6% (case 2), 1.1% (case 3) and 6.7% (case 4) became positive in HTLV-I PCR-ISH. UCHL-1-negative cells were HTLV-I PCR-ISH negative and almost all KP-1-positive cells were HTLV-I negative. HTLV-I was localized to OPD4-positive cells in examined lesions of cases 2 and 4. These data are a direct demonstration of HTLV-I proviral DNA localizing to infiltrated T cells in HAM/TSP spinal cord lesions.

Midkine exists in astrocytes in the early stage of cerebral infarction

Midkine (MK), a heparin-binding neurotrophic factor, is expressed in the early stage of experimental cerebral infarction in the zone surrounding the infarct. Double immunostaining with anti-MK and anti-glial fibrillary acidic protein showed existence of MK in astrocytic cytoplasm on postoperative day 2. Immunoelectron microscopic analysis revealed the presence of MK in the swollen astrocytic processes on postoperative day 4.

[A case of rapidly progressive HTLV-I-associated myelopathy (HAM)]

We report a 65-year-old woman with HAM who showed rapid progression of the clinical symptoms. The initial symptom was lumbago and she became unable to walk within 4 months after the onset of the lumbago. When seen on admission, she had flaccid paraplegia and areflexia was seen in the lower extremities with positive Babinski and Chaddock reflexes. She had numbness below the level of the navel, vibratory sensation was decreased in both lower limbs, and there was a hyperesthesic zone at the tenth thoracic vertebral level. She had a difficulty in urination and defecation. Laboratory examination revealed elevated anti-HTLV-I antibody titers both in serum (4,096x by PA method) and in cerebrospinal fluid (CSF) (4,096x). The levels of IgG and neopterin in CSF were also increased to 16.6 mg/dl (normal: < 5 mg/dl) and 360.3 pmol/ml (normal: < 30 pmol/ml), respectively. HTLV-I messenger RNA positive cells were detected in 0.1% to 0.01% of cells in CSF by in situ hybridization using an oligonucleotide probe labelled with alkaline phosphatase. Spinal cord MRI detected neither spinal cord compression nor vascular diseases. She was treated with 1,000 mg methylprednisolone for 3 days intravenously, followed by 60 mg oral prednisolone therapy. In several days after receiving the treatments, her muscle tonus became spastic and deep tendon reflexes in the legs became brisk. The hyperesthesia at the tenth thoracic vertebral level and numbness below the level of the navel were also gradually improved. Subsequently, her clinical features were consistant with those of the typical HAM. Therefore, the patient was diagnosed as rapidly progressive HAM. The initial phase of rapidly progressive HAM patients had been described only from clinical history. These patients had common characteristic clinical features, such as older age at onset, relatively severe motor dysfunction, high titers of anti-HTLV-I antibody in CSF, and increased levels of neopterin and IgG in CSF, when compared with those of other HAM patients. The clinical course and laboratory findings in the present patient were compatible with those in the previous cases reported as rapidly progressive HAM. This patient showed flaccid paraplegia and areflexia which have rarely been seen in HAM patients. However, these symptoms were changed to spastic and hyperactive after prednisolone therapy. We speculate that inflammation in the spinal cord in this patient was severe enough to spread to the dorsal root, and disturbed the afferent pathway from the peripheral to the central nervous system. This inflammatory reaction might be suppressed by prednisolone to facilitate the recovery of the afferent pathway, which led to the typical clinical symptoms of HAM.

Human T-cell lymphotropic virus type 1 can infect primary rat retinal glial cells and induce gene expression of inflammatory cytokines

PURPOSE

To examine whether or not retinal glial cells can be infected by human T-cell lymphotropic virus type 1 (HTLV-1) and test the possibility that HTLV-1-infected retinal glial cells are involved in the pathogenesis of HTLV-1 uveitis (HU).

METHODS

We tested infection of HTLV-1 by a standard coculturing method using WKAH rat retinal glial cells and irradiated MT-2, a human T cell line that produces HTLV-1. Infection was confirmed by detecting the integrated HTLV-1 provirus, using polymerase chain reaction (PCR), viral gene expression, using reverse transcriptase-PCR (RT-PCR) and HTLV-1 p19 ELISA, and by identifying the HTLV-1-infected glial cells by immunofluorescence cytochemistry and in situ hybridization. Changes in cytokine gene expression were studied by RT-PCR.

RESULTS

Using a semiquantitative PCR of HTLV-1 provirus sequence, we found that 2.6% of the retinal glial cells were infected at 3 days after infection, followed by a gradual decrease in the percentage with an extended period of culture up to 4 weeks. This time course of infection was also verified by RT-PCR and ELISA studies that detect viral mRNA expression and protein production, respectively. Expression of HTLV-1 gag protein and tax mRNA was detected in a part of glial cells by indirect immunofluorescence cytochemistry and in situ hybridization, respectively. RT-PCR analysis of cytokine gene expression revealed that gene expression of IL-6, CINC-1 (Gro, KC), and TNF-alpha were induced in these cells, with a peak at 3 weeks after infection.

CONCLUSION

These results provided supportive evidence for the theory that the infection of retinal glial cells by HTLV-1 and subsequent production of inflammatory cytokines could be one contributing factor for the development of the unique clinical features of HU. A better understanding of the specific roles of the inflammatory cytokines in the pathogenesis of HU would be beneficial in the treatment and control of this disease.

Human T-lymphotropic virus type I-associated myelopathy and tax gene expression in CD4+ T lymphocytes

Infection by human T-lymphotropic virus type I (HTLV-I) is associated with adult T-cell leukemia and a slowly progressive disease of the central nervous system (CNS), HTLV-I-associated myelopathy/tropical spastic paraparesis, characterized pathologically by inflammation and white matter degeneration in the spinal cord. One of the explanations for the tissue destruction is that HTLV-I infects cells in the CNS, or HTLV-I-infected CD4+ T lymphocytes enter the CNS, and this drives local expansion of virus-specific CD8+ cytotoxic T lymphocytes, which along with cytokines cause the pathological changes. Because both in the circulation and in the cerebrospinal fluid, CD8+ cytotoxic T lymphocytes are primarily reactive to the product of the HTLV-I tax gene, we sought evidence of expression of this gene within cells in the inflammatory lesions. After using double-label in situ hybridization techniques, we now report definitive localization of HTLV-I tax gene expression in CD4+ T lymphocytes in areas of inflammation and white matter destruction. These findings lend support to a hypothetical scheme of neuropathogenesis in which HTLV-I tax gene expression provokes and sustains an immunopathological process that progressively destroys myelin and axons in the spinal cord.

Immunological abnormality in patients with lysinuric protein intolerance

Lysinuric protein intolerance (LPI) is a rare hereditary disorder manifesting hyperammonemia induced by low levels of basic amino acids, these low levels being due to the impaired transport of these acids in the intestinal mucosa and the renal tubules. Low serum arginine levels and probably the consequently low in vivo levels of nitric oxide (NO), which against acts as a physiological and immunological mediator/modulator, are thought to influence the immunological status in patients with LPI. Accordingly, this study was conducted to. We found that patients with LPI had leukocytopenia, high serum IgG levels, a high ratio of CD44B4-positive lymphocytes (helper inducer) to CD42H4-positive lymphocytes (suppressor inducer), low levels of leukocyte phagocytic, cytotoxic, and natural killer cell activity, and increased spontaneous proliferation of lymphocytes. These results were probably the consequence of persistent low NO levels in vivo.