Clinical implication of florid reactive follicular hyperplasia in Japanese patients 60 years or older: a study of 46 cases

Florid reactive follicular hyperplasia (FRFH) of the enlarged lymph node in middle-aged or elderly patients requiring biopsy is a relatively uncommon phenomenon as compared with that in younger age groups. Between 1984 and January 2004, we encountered 46 patients, aged 60 years or older, in whom histology of biopsied lymph node specimens showed inappropriate FRFH for the patient's age. An apparent cause of lymphadenopathy was initially identified in 17 cases (37%): 11 with autoimmune disease and related disorders, 3 with cancer-reactive lymphadenopathy, 2 with Epstein-Barr virus-associated lymph node lesion exhibiting transient autoimmune-disease-like clinical findings, and 1 with atypical mycobacterial infection. Among 29 patients without specific etiology, 16 patients (55%) exhibited histologic findings of progressive transformed germinal center (PTGC). Only 1 of our patients developed malignant lymphoma during the follow-up period. The present study indicates that PTGC is included in the etiology of FRFH in elderly Japanese patients as well as imbalance of the immune system such as autoimmune-disease-associated lymphadenopathy and idiopathic plasmacytic lymphadenopathy with polyclonal hyperimmunoglobulinemia. By in situ hybridization, Epstein-Barr virus genomes were demonstrated in only 6 (15%) of 39 cases examined.     

Effect of continuous infusion of propofol on its concentration in blood with and without the liver in pigs

In living donor liver transplantation, propofol, an intravenous anesthetic drug, has recently been used in both donors and recipients. Propofol is known to have intra- and extrahepatic metabolic pathways, but the effect of its continuous infusion during a long-term anhepatic state is yet to be determined. Recently, we successfully established a simplified pig model of the complete anhepatic state. In this state, we first evaluated hemodynamic parameters relating to the pharmacokinetics of continuously infused propofol (6 mg.kg(-1) x h(-1)). No significant changes in the concentration of hemoglobin or in hemodynamic parameters other than the heart rate were observed during the anhepatic phase when porpofol was continuously infused at the rate that maintains the state. Blood propofol concentrations in the mixed vein, artery, and portal vein were stable during the anhepatic phase. Finally, we confirmed the pharmacokinetics of continuously infused propofol using orthotropic liver transplantation in miniature pigs. The propofol concentration did not change markedly during the transplant procedure. In conclusion, the pharmacokinetics of continuously infused propofol was almost stable with and without the liver in pigs. Extrahepatic metabolism of propofol might help prevent changes in propofol concentrations.     

Evaluation of intraoperative infusion solution using a complete anhepatic model in baby pigs

Compared to cadaveric liver transplantation, living-related liver transplantation (LRLT) has the physiological advantage of avoiding hemodynamic changes due to the nonsystemic clamping of the inferior vena cava (IVC). However, metabolic changes in the level of blood glucose and lactate usually occur during the anhepatic phase in LRLT. For pediatric patients, intraoperative infusions have the potential to maintain immature homeostasis during LRLT. In the present study, a complete anhepatic model of baby pigs with nonsystemic clamping of IVC, which mimics the procedure of pediatric LRLT, was established using a heparin-coated tube as an internal shunt lactate Ringer solution (LR, Lactec), acetate Ringer solution (AR, VeenF), and a solution comprising acetate Ringer with 1% glucose (AR-G, Phisio140) were tested using piglets. Hemodynamic and metabolic (blood gas analysis, electrolytes, blood lactate, and glucose) changes were observed during the anhepatic phase. Although no major difference was observed in hemodynamic parameters, arterial blood gas data, or concentration of electrolytes among the three solution groups, significant progressive hyperlactatemia was observed in the LR group. Also, though severe hypoglycemia was found in the LR and AR groups, the AR-G group maintained blood glucose levels throughout the anhepatic phase. To conclude, using the simplified pig anhepatic model, we evaluated various solutions for pediatric LRLT.     

Multiple cystic cavernous angiomas associated with hemorrhage

Summary. A 29-year-old man presented with impaired mental concentration and inability to remember. Magnetic resonance and computed tomography studies revealed multiple calcified cysts. Craniotomy was performed and one of the lesions was resected. The histological diagnosis was cavernous angioma. The first report of multiple cystic cavernous angiomas is reported.     

13C-Relaxationsuntersuchungen zum Einfluß des Lösungsmittels auf die Kettenbewegung von Polystyrol

Temperature dependent measurements of ¹³C spin lattice relaxation times and of nuclear Overhauser enhancement factors were carried out for atactic and isotactic polystyrene in tetrahydrofuran and for atactic polystyrene in 1,4-dioxane. The analysis of the relaxation data by means of a Cole-Cole distribution of correlation times confirms the additivity of intramolecular and solvent viscosity dependent activation energies. For atactic and isotactic polystyrene the same intramolecular activation energy of 21 ± 5kJ/mol is obtained for the segmental motion. A comparison with ¹³C relaxation measurements of other authors shows that the intramolecular activation energies and the anisotropy of the segmental motion are increasing simultaneously by changing the solvent from toluene over pentachloroethane to tetrahydrofuran. Based on the experimental findings the chain motions in polystyrene are interpreted as diffusion controlled processes in the hindering potential of the C? C bonds of the chain backbone which is modified by conformation dependent interactions between phenyl groups and solvent molecules.     

Endoplasmic reticulum stress induced in motor neurons by transient spinal cord ischemia in rabbits

OBJECTIVE: The mechanism of spinal cord injury has been thought to be related to the vulnerability of spinal motor neuron cells against ischemia. However, the mechanisms of such vulnerability are not fully understood. Because we previously reported that spinal motor neurons were probably lost as the result of programmed cell death, we investigated a possible mechanism of neuronal death by immunohistochemical analysis for Grp78 and caspase12. METHODS: We used a rabbit spinal cord ischemia model with a balloon catheter. The spinal cord was removed at 8 hours or 1, 2, or 7 days after 15 minutes of transient ischemia. Histologic changes were studied with hematoxylin-eosin staining. Western blot analysis for Grp78 and caspase12, temporal profiles of Grp78 and caspase12 immunoreactivity, and double-label fluorescence immunocytochemical studies were performed. RESULTS: The majority of motor neurons were preserved for 2 days but were selectively lost at 7 days of reperfusion. Western blot analysis revealed scarce immunoreactivity for Grp78 and caspase12 in the sham-operated spinal cords. However, immunoreactivity for Grp78 and caspase12 became apparent at 8 hours after transient ischemia, which returned to the baseline level at 1 day. Double-label fluorescence immunocytochemical study revealed that both Grp78 and caspase12 were positive at 8 hours of reperfusion in the same motor neurons that eventually die. CONCLUSION: This study demonstrated that immunoreactivities for both Grp78 and caspase12 were induced in the same motor neuron that eventually dies. These results suggest that endoplasmic reticulum stress was induced in motor neurons by transient spinal cord ischemia in rabbits.     

High throughput screening of pharmacokinetics and metabolism in drug discovery (II)--investigation on in vitro and in vivo correlation in drug metabolism screening

Metabolic screening using liver microsomes of rats and humans is an indispensable tool to optimize a lead structure and to select compounds for in vivo study. Elucidating the relationship between in vitro intrinsic clearance (CL(int, app)) and in vivo clearance (CL(b)) is a prerequisite for screening. We investigated the relationship between CL(int, app) in rat liver microsomes and CL(b) after intravenous administration in rats in eight projects. No relationship between these two parameters was found across all of the projects examined. However, there was a certain relationship in the same core structure of six projects, but not in the other two projects. The poor correlation in the projects was improved by considering serum protein binding or microsomal binding in the estimation of in vitro clearances. Although the binding assay was labor intensive, unlike metabolic screening, the introduction of the equilibrium dialysis method using a 96-well format increased the throughput. Optimization of metabolic stability was conducted on the basis of the structure-metabolic stability relationship (SMR) in one of the projects, showing a good correlation without the binding factors. The replacement of the piperazine with a homopiperazine moiety improved metabolic stability in the rat and human liver microsomes. The compound also showed a desirable in vivo pharmacokinetic profile in rats, suggesting that the SMR study on the confirmed in vitro and in vivo correlation is essential to the optimization.     

High throughput screening of pharmacokinetics and metabolism in drug discovery (I)--establishment of assessment system for absorption to compounds with a wide diversity of physical properties

The application of combinatorial chemistry and high-throughput screening to biological targets has led to efficient identification of lead compounds in wide therapeutic areas. However, the physicochemical properties of some lead compounds are lipophilic with low water soluble. Since these parameters determine in vivo absorption, we established robust screening methods for solubility and Caco-2 membrane permeability which are applicable to our screening strategy based on the structure-pharmacokinetic parameter relationship (SPR). Of test compounds with different core structures, turbidimetric solubility and apparent solubility as determined by HPLC-UV analysis after dilution of aqueous media from DMSO stock solution was overestimated in comparison with the corresponding thermodynamic solubility obtained using a traditional shake-flask method. A new powder-dissolution method providing thermodynamic solubility similar to that in the traditional method was developed using 96-well plates for equilibrium dialysis. The throughput of the method was the almost the same as that using the apparent solubility method. In a conventional Caco-2 assay, membrane permeability (P(app)) of some lipophilic compounds was underestimated due to low solubility in the apical site and adhesion to the device, resulting in a poor relationship between the in vivo absorption fraction and the P(app) values. The addition of 0.1% Gelucire 44/14 into the apical site and 4% bovine serum albumin into the basolateral site improved the relationship. These newly developed methods are therefore useful to optimize lead compounds with less water solubility and high lipophilicity on the basis of SPR.     

Indole alkaloids of a Thai medicinal herb, Mitragyna speciosa, that has opioid agonistic effect in guinea-pig ileum

Recently, we found that mitragynine, a major constituent of Mitragyna speciosa, has an opioid agonistic activity, but its weak potency could not explain the opium-like effect of this plant. In the present study, bioassay-guided fractionation of the crude extract of the leaves of M. speciosa was carried out to search for potent opioid agonists other than mitragynine. Opioid agonistic activities were evaluated using twitch contraction induced by electrical stimulation in guinea-pig ileum. The crude extract of M. speciosa inhibited the twitch contraction in a concentration-dependent manner. The inhibition was reversed by naloxone. The opioid effect was detected only in the crude base fraction, which was followed by the isolation of five indole alkaloids. Among these alkaloids, 7-hydroxymitragynine showed the most potent opioid effect on the electrically-stimulated contraction (pD (2) = 8.38 +/- 0.12). The potency, calculated using pD (2) values, was 30- and 17-fold higher than that of mitragynine and morphine, respectively. Antagonism of naloxone on concentration-response curves for 7-hydroxymitragynine confirmed its opioid effect. These results suggest that the opioid effect of M. speciosa is mostly based on the activity of 7-hydroxymitragynine.