[Effect of selenium on serum, hepatic and lipoprotein lipids concentration in rats fed on a high-cholesterol diet]

The effects of Selenium (Se) on lipid metabolism was studied in male Wistar rats which were fed a high-cholesterol diet (HCD) containing 1%(w/w) cholesterol and 0.5%(w/w) cholic acid for 10 weeks. Se was orally administered at daily doses of 0.173 mg/kg in HCD into the test rats for 10 weeks. As compared with control groups, Se/HCD suppressed the amounts of triglyceride (TG), total cholesterol (CH) and free fatty acid in the serum. Se/HCD also decreased the amounts of low-density lipoprotein cholesterol (LDL-C) in the serum. Further-more, Se/HCD inhibited the amount of liver TG and CH. The activity of fatty acid synthetase in the HCD fed group was higher than in the Se/HCD fed group. These results suggest that Se may have recuperative effects for hypercholesterolemia.

Effect of particle size of polymeric nanospheres on intravitreal kinetics

In this study, we injected nanospheres containing a fluorescein derivative into the vitreous cavity of pigmented rabbit eyes and evaluated their intraocular kinetics as drug carriers in vivo. Polystyrene nanospheres (2 microm, 200 nm and 50 nm in diameter) containing a fluorescein derivative were used in this study. A suspension of each particle was prepared by diluting with distilled water at a concentration of 10 microg/ml equivalent to sodium fluorescein. The suspension of nanospheres was injected once into the vitreous cavity of unilateral eyes of pigmented rabbits. A sodium fluorescein solution of the same concentration was injected once into the vitreous cavity of the other eye as the control. The intraocular kinetics of nanospheres was evaluated by measuring vitreous fluorescence using a scanning fluorophotometer. To investigate elimination pathways of nanospheres in detail, serial cross-sections of the eyes were examined with a fluorescence microscope. The fluorescence derived from nanospheres was observed in the vitreous cavity for over 1 month (2 microm: t(1/2) = 5.4 +/- 0.8 days, 200 nm: t(1/2) = 8.6 +/- 0.7 days, 50 nm: t(1/2) = 10.1 +/- 1.8 days), whereas that in the control eyes completely disappeared within 3 days (t(1/2) = 7.8 +/- 0.7 h). The elimination half-life from the vitreous cavity correlated well with the particle diameter (r = -0.997, p = 0.007). Histological studies using a fluorescence microscope revealed that nanospheres with a diameter of 2 microm were seen in the vitreous cavity and trabecular meshwork, while nanospheres with a diameter of smaller than 200 nm were also observed in the retina as well as these tissues. Our findings indicated that nanospheres may be beneficial as a drug carrier to the retina, vitreous and trabecular meshwork.

[Accuracy of MiniWright peak expiratory flow meters]

OBJECTIVE: To evaluate the accuracy of the Mini-Wright (Clement Clarke International Ltd.) peak-flow meters. METHODS: Twenty of those meters were checked by use of electronic calibration syringe (Jones Flow-Volume Calibrator(R)). Nine of them had an old scale, with values displayed equidistantly, and eleven had a new mechanical scale with non-equidistant values. Each device was connected in series to the calibration syringe to perform eight hand-driven volume injections, with flows ranging from 100 to 700 l/min. Absolute and relative differences between meters and syringe were calculated, the syringe values taken as standard. The accuracy of the twenty Mini-Wright devices was validated by the American Thoracic Society criteria (-/+ 10% or -/+ 20 l/min), and/or European Respiratory Society criteria (-/+ 5% or -/+ 5 l/ min). RESULTS: New scale instruments were more accurate than old scale meters (p < 0.001), by both ATS and ERS criteria. Every meter was rechecked after 600 measurements. Both the old, and the new scale instruments maintained the same level of performance after this evaluation. CONCLUSIONS: Results suggest that new scale meters were accurate and can be safely used in clinical practice. The authors strongly recommend that they are rechecked regularly to ensure that they are within the ATS and ERS variation limits.

Ocular and systemic features of Peters' anomaly

BACKGROUND

To clarify the relationship between associated systemic anomalies and ocular manifestations in patients with Peters' anomaly, a retrospective study was conducted.

METHODS

We classified 37 patients with Peters' anomaly into two groups, one with (+) and one without (-) systemic anomalies.

RESULTS

The systemic anomaly (+) group consisted of 13 patients, eight males and five females, with mean age of 2.3 months. Peters' anomaly was bilateral in six cases and unilateral in seven. Corneolenticular adhesion was observed in 11 cases. Associated ocular anomalies were seen in 12 cases, and developmental glaucoma was present in eight cases. The systemic anomaly (-) group comprised 24 patients, 13 males and 11 females, with mean age of 28.3 months. Peters' anomaly was bilateral in 11 cases and unilateral in 13. Corneolenticular adhesion was observed in five cases. The associated ocular anomalies were observed in 10 cases, and developmental glaucoma was accompanied in six cases. The incidences of cases with corneolenticular adhesion, those with other ocular anomalies, and those with glaucoma were significantly higher in the systemic anomaly (+) group than in the systemic anomaly (-) group.

CONCLUSIONS

Peters' anomaly accompanying corneolenticular adhesion and/or other ocular anomalies should be evaluated for the presence of systemic anomalies.

Eggplant (Solanum melongena) infusion has a modest and transitory effect on hypercholesterolemic subjects

Eggplant (Solanum melongena) is consumed extensively in Brazil. It has been believed that infusion of a powdered preparation of the fruit may reduce serum cholesterol. However, there are few documented reports on its effects on cholesterol metabolism and its possible hypocholesterolemic effect has not been proved by well-controlled studies. The aim of the present study was to observe the effects of S. melongena on the serum cholesterol and triglycerides of 38 hypercholesterolemic human volunteers ingesting S. melongena infusion for five weeks. Thirty-eight hypercholesterolemic subjects receiving either S. melongena infusion (N = 19) or placebo (N = 19) participated in two clinical experiments in which the effect of S. melongena infusion was studied with (N = 16) or without (N = 38) dietary orientation. Total cholesterol and its fractions, triglycerides, and apolipoproteins A and B were measured in blood at the beginning of the experiment and three and five weeks thereafter. No differences were observed compared to control. Intraindividual analysis showed that S. melongena infusion significantly reduced the blood levels of total and LDL cholesterol and of apolipoprotein B. After dietary orientation, no intra- or intergroup differences were seen for any of the parameters analyzed. The results suggest that S. melongena infusion had a modest and transitory effect, which was not different from that obtained with standard orientation for dyslipidemia patients (diet and physical activities).

A comparison of prednisolone and methylprednisolone for renal transplantation

A large difference in immunosuppressive potency between methylprednisolone and prednisolone has been suggested in vitro. However, the selection of the best glucocorticoid for renal transplantation has been seldom considered so far. Thus, the present study was undertaken to compare therapeutic efficacy between prednisolone and methylprednisolone in renal transplantation. We studied 42 renal transplant recipients who were operated on between 1990 and 1994. The patients were divided into two treatment groups: a methylprednisolone/ cyclosporine group (n = 19) and a prednisolone/cyclosporine group (n = 23). Clinical outcome and drug side effects were compared retrospectively between the treatment groups 24-84 months after transplantation. The overall graft survival time in patients treated with methylprednisolone/cyclosporine was superior to that in patients treated with prednisolone/cyclosporine (p < 0.05). Among the recipients from cadaver donors, 5/16 (31.3%) treated with prednisolone required nephrectomy, whereas none of the 10 patients treated with methylprednisolone received nephrectomy (p < 0.01). An examination of the recipients from living related donors revealed that serum creatinine levels 24-36 months after operation were significantly lower in the methylprednisolone group (p < 0.05). Cyclosporine trough levels and glucocorticoid side effects were similar between the treatment groups. The results raised the possibility that methylprednisolone is superior to prednisolone when combined with cyclosporine for maintenance immunosuppressive therapy in renal transplantation.

The mouse L-histidine decarboxylase gene: structure and transcriptional regulation by CpG methylation in the promoter region

To investigate the regulation of mouse L-histidine decarboxylase (HDC) gene expression, we isolated genomic DNA clones encoding HDC. Structural analysis revealed that the mouse HDC gene was composed of 12 exons, spanning approximately 24 kb. Northern blotting analysis indicated that, among the cell lines examined, a high level of HDC gene expression was restricted to mature mast cell lines and an erythroblastic cell line. The gene was induced strongly in the mouse immature mast cell line P815 after incubation in the peritoneal cavity of BDF1 mice. We observed that the promoter region was demethylated in the HDC-expressing cell lines and in induced P815 cells. Interestingly, forced demethylation by 5-azacytidine (5-azaC) treatment induced high expression of HDC mRNA in P815 cells. The activity of a mouse HDC promoter-reporter construct stably transfected in P815 cells was repressed by in vitro patch-methylation. This low promoter activity of the patch-methylated reporter construct was restored after 5-azaC treatment, which demethylated the patch-methylated promoter. These results indicate that DNA methylation state of the promoter region controls HDC gene expression.

Relationship between effects of alcohol on psychomotor performances and blood alcohol concentrations

Ethanol is a social drug and has been generally known to be a CNS depressant. A large fluctuation of blood alcohol concentration (BAC) is well-known to occur due to main factors such as the genetic polymorphism of the main alcohol metabolizing enzymes and the effect of blood. Few studies have substantially discussed the relationship between impaired CNS activities and BAC. In this study, focusing on the correlation of BAC, we investigated the acute effects of alcohol intake on cognitive performance in humans by objective evaluation methods consisting of the attention-demanding cognitive tasks. Tasks were administered to ten healthy male volunteers before and after ingesting established amounts of alcohol. With increased BAC, we observed prolongation of reaction time performances and lowering of a coordination performance. From the results, we concluded that cognitive performance deteriorates with an increase of BAC. Additionally, the BAC threshold that causes significant impairment of cognitive performance was estimated to be approximately 50 mg/dl (ca. 10 mM).

L-Histidine decarboxylase protein and activity in rat brain microvascular endothelial cells

OBJECTIVE AND DESIGN

L-Histidine decarboxylase (HDC) is the primary enzyme regulating histamine biosynthesis. This study was carried out to examine whether the cultured rat brain microvascular endothelial cells (BMEC), which constitute the blood-brain barrier (BBB), have the ability to form histamine, and whether HDC mRNA is expressed in rat BMEC.

MATERIAL

Male, 3-week-old Wistar rats were used. For in vitro studies, rat BMEC were isolated from rat brains, and subculture cells were grown on collagen-coated culture flask and slide.

METHODS

HDC assay, immunofluorescence analysis and expression of HDC mRNA by RT-PCR were performed in rat BMEC.

RESULTS

The HDC activity of the BMEC was estimated to be 0.14 +/- 0.05 p mol/min/mg protein. This activity was completely inhibited by (S)-alpha-fluoromethylhistidine, a specific inhibitor of HDC. Using a polyclonal anti HDC antibody and immunofluorescence microscopy, we confirmed the presence of HDC protein in rat BMEC. RT-PCR also showed the expression of HDC mRNA in rat BMEC.

CONCLUSIONS

L-Histidine uptaken by rat BMEC was shown to be converted to histamine, suggesting that HDC plays an important role in BBB.

Lymphocyte-sensitivity to glucocorticoid correlates with the sensitivity to cyclosporin A and tacrolimus in chronic renal failure patients

AIMS

Association between lymphocyte-sensitivity to immunosuppressants in transplant recipients in vitro and clinical outcomes has been demonstrated. In general, renal transplant recipients are treated with a combination of immunosuppressants such as either glucocorticoid/cyclosporin A (CsA) or glucocorticoid/tacrolimus (FK506) but the pharmacological complementarity of these drugs is still controversial. We examined relationships between the lymphocyte-sensitivities to these immunosuppressants.

METHODS

We examined lymphocyte-sensitivities to prednisolone (PSL), CsA, and FK506 in vitro in a total of 190 chronic renal failure (CRF) patients and 140 healthy subjects. The lymphocyte-sensitivity was evaluated from the IC50 value against mitogen-stimulated lymphocyte-blastogenesis in vitro.

RESULTS

Statistically significant correlations of the IC50 values in CRF patients between the following pairs of drugs were observed: PSL and CsA (P<0.0001; n=129, r=0.419), PSL and FK506 (P<0.001; n=54, r=0. 441), and CsA and FK506 (P<0.0001; n=45, r=0.608). Similar correlations were also observed in lymphocytes from healthy subjects. The population of CRF patients who exhibited high IC50 values (low sensitivities) to PSL and FK506 was significantly larger than that of healthy subjects (P<0.05).

CONCLUSIONS

Patients who showed low lymphocyte-sensitivity to either of the drugs also may exhibit low sensitivity to the others, and thus they may have a high risk of unsatisfactory outcome under combination therapy after renal transplantation. To overcome this risk, the selection of immunosuppressants is recommended to be restricted according to individual lymphocyte-sensitivities to these drugs in vitro, or alternatively, by addition of other drugs with different mechanisms for immunosuppression.

Effects of the acute and chronic restraint stresses on the central histaminergic neuron system of Fischer rat

The effects of acute and chronic restraint stresses on the brain histamine level and histamine N-methyltransferase activity in Fischer rat brain were studied. The acute restraint stress increased the histamine levels in the diencephalon and nucleus accumbens, and increased the histamine N-methyltransferase activities in the nucleus accumbens and striatum. The chronic restraint stress also increased histamine N-methyltransferase activities in the nucleus accumbens and striatum. These results indicate that the acute and chronic restraint stresses increase the brain histamine turnover, which may partly relate to the vulnerability for stress-induced anxiety and depression.

[Management of mycobacteriosis in general hospital without isolation ward for tuberculosis patients. 5. The management of the patients excreting tubercle bacilli in a university hospital without isolation ward for tuberculosis]

The Japanese low ruled that the patients excreting tubercle bacilli should be treated in the isolated ward for tuberculosis. However, it is often difficult to transfer a patient with serious illness to the isolated ward with insufficient medical facilities. We investigated retrospectively the manner of the management of patients excreting tubercle bacilli in the Aichi Medical University Hospital without the isolation ward for tuberculosis. Materials were 166 patients (0.17%) out of 97,275 in-patients during 11 years since 1986 to 1996. Respiratory symptoms were observed in 114 patients (68.7% of 166 patients) on admission. The initial bacteriological examination was ordered by the attendant doctor within a week in 93 patients (81.6%) of 114 patients with respiratory symptoms. On the other hand, a half of the 52 patients without respiratory symptoms on admission were not examined for sputum bacteriology beyond a week. Anti-tuberculous treatment was started within a week after positive bacteriological results in 129 patients (77.7% of the whole 166 patients), while the treatment was not carried out or delayed in 21 patients (12.6%) because of the communication failure of the bacteriological report to the physicians. Some complications were observed in 101 patients: 21 diabetes mellitus, 20 cancers, 15 hematological disorders, 9 collagen diseases, 6 renal failures on dialysis. Serious illnesses were observed in 33 patients (20.6% of the 166 patients). Twenty-four patients (73% of the seriously ill patients) were died of renal failure, pancytopenia, cancer or respiratory failure. We considered that an isolated room for infectious tuberculosis with independent air conditioning system in a general hospital or a educational hospital was very convenient not only to the treatment of the patients with serious complications, but also to the education and training on tuberculosis for the medical student or medical stuffs.

Stereoselective blood-brain barrier transport of histidine in rats

The transport characteristics of l- and d-histidine through the blood-brain barrier (BBB) were studied using cultured rat brain microvascular endothelial cells (BMEC). l-Histidine uptake was a saturable process. A decrease in incubation temperature from 37 to 0 degreesC or the addition of metabolic inhibitors (DNP and rotenone) reduced the uptake rate of l-histidine. Ouabain, an inhibitor of (Na+, K+)-ATPase, also reduced uptake of l-histidine. Moreover, the substitution of Na+ with choline chloride and choline bicarbonate in the incubation buffer decreased the initial l- and d-histidine uptake rates. These results suggested that l-histidine is actively uptaken by a carrier-mediated mechanism into the BMEC, with energy supplied by Na+. However, l-histidine uptake at 0 degreesC was not completely inhibited, and it was reduced in the presence of an Na+-independent System-L substrate, BCH, suggesting facilitated diffusion (the Na+-independent process) by a carrier-mediated mechanism into the BMEC. l-histidine uptake in rat BMEC also appeared to be System-N mediated since uptake was inhibited by glutamine, aspargine and l-glutamic acid gamma-monohydroxamate. System-N mediated transport was not pH sensitive. d-histidine transport was also studied in rat BMEC. d-histidine transport by rat BMEC has similar characteristics to l-histidine. However, System-N transport did not play a role in d-histidine uptake. The uptake of l-histidine was also greater than that of the d-isomer, indicating the stereoselective uptake of histidine in rat BMEC.

Behavioural characterization and amounts of brain monoamines and their metabolites in mice lacking histamine H1 receptors

Behavioural assessments were made of mutant mice lacking histamine H1 receptors to reveal the function of H1 receptors in the behaviour of mice. Exploratory behaviour of mice in a new environment was examined to discover whether the absence of H1 receptors in mice affects actions relating to their emotions. The H1 receptor-deficient mice showed a significant decrease in ambulation in an open field and on an activity wheel. Cognitive functions and anxiety were examined using passive avoidance response test and the elevated plus-maze test, respectively. The passive avoidance test did not show any change in latency. The elevated plus-maze test revealed that the transfer latency of the mutant mice was significantly prolonged, indicating that H1 receptors are partly associated with the control of anxiety. Aggressive behaviour was examined by a resident-intruder aggression test. When confronted with an intruder, the mutant mice attacked the intruder significantly slower and less frequently than did wild-type mice after a six-month isolation period. A formalin test and a forced swimming test were used to evaluate the nociceptive response and depressive or despairing state, respectively, of both groups. The mutant mice showed a significant decrease of nociceptive response in the late phase without affecting the early phase. There was no significant difference in the forced swimming test between the two groups. The brain content of monoamines and their metabolites was measured in the H1 receptor null and wild-type mice. The turnover rate of 5-hydroxytryptamine defined by the ratio of 5-hydroxyindoleacetic acid and 5-hydroxytryptamine was significantly increased in the cerebral cortex and hippocampus of H1 receptor null mice. These results support the previous pharmacological findings that histamine modulates various neurophysiological functions such as locomotor activity, emotion, memory and learning, nociception and aggressive behaviour through H1 receptors.

Kinetics of buccal absorption of propafenone single oral loading dose in healthy humans

Buccal absorption has an advantage when compared with other administration routes because of its rapid onset of action. We examined the pharmacokinetics of buccal-absorbed propafenone in healthy humans. 1. After a single oral administration of 150 mg of propafenone, the average peak concentration of propafenone was 27.9+/-2.5 ng/ml, and that of 5-hydroxypropafenone was 61.7+/-6.6 ng/ml (n=5). The times to reach peak serum concentrations of propafenone and 5-hydroxypropafenone were 1.8+/-0.1 hr and 1.5+/-0.2 hr, respectively. 2. After a buccal absorption of 150 mg of propafenone, the time to reach peak serum concentration of propafenone was 16.9+/-2.3 min (n=8). The average peak concentration of propafenone was 30.4+/-1.4 ng/ml (n=8), and the concentrations of 5-hydroxypropafenone were below the detection limit in all subjects. The rapid upstroke of serum concentrations of propafenone by buccal administration may cause rapid onset of pharmacological conversion.