Effect of cod-liver oil extract on the buccal permeation of ergotamine tartrate

Ergotamine tartrate (ET) is used clinically in the treatment of migraines. However, the bioavailability of ET is rather poor following oral administration. Therefore, we tried to improve ET delivery using buccal administration. The purpose of this study was to investigate the characteristics of the permeation of ET through the hamster cheek pouch in vitro using a two-chamber diffusion cell, and to evaluate the effect of permeation enhancers on the transbuccal delivery of ET. Cod-liver oil extract (CLOE), polyoxyethylene hydrogenated castor oil (HCO 60), sodium glycocholate (GC), and sodium caprate (CA) were selected as premeation enhancers considering their low irritancy of the mucosa. When the enhancers were added to the donor cell at a 5% concentration each, the ET permeation rate markedly increased compared with that in a control not containing enhancer. Among these enhancers, CLOE exhibited the greatest effect. Because CLOE is composed of 16 kinds of fatty acids, the enhancement action of each of the major components was separately determined. As major fatty acids, palmitic acid, oleic acid, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) were selected and their enhancing effects were studied. The enhancing effect of each fatty acid was significantly lower than that of CLOE.

High absorbency and subchronic morphologic effects on the nasal epithelium of a nasal insulin powder dosage form with a soybean-derived sterylglucoside mixture in rabbits

A soybean-derived sterylglucoside mixture (SG) is a potential enhancer of the nasal absorption of insulin. The aim of the study was to examine the absorption of insulin given as the powder dosage form with SG and excipient and to determine the subchronic effects of SG on the morphology of rabbit nasal epithelium. The insulin powder dosage form with SG was administered to the rabbit nasal cavity for five successive days. The average bioavailability and the average pharmacological bioavailability of insulin were about 25.0 and 61.6%, respectively. The nasal mucosa was taken from the nasal cavity and side-effects were investigated using an optiphoto light microscope. The insulin powder dosage form with SG produced no signs of inflammation, erosion or squamous metaplasia. These findings indicate that SG can be considered as a safe and effective enhancer and excipient in the nasal insulin powder dosage form.

Influence of acute uraemia on percutaneous absorption of nonsteroidal anti-inflammatory drugs

The influence of uraemia on percutaneous absorption of three model drugs (diclofenac, ibuprofen and indomethacin) which are eliminated entirely via nonrenal route was investigated in the rats. Following day after bilateral nephrectomy (BUN levels were between 30-50 mmol/l), gel ointment containing drugs under test was applied on the abdominal site of the skin. Comparing with the sham operated controls the percutaneous absorption significantly decreased in all three challenged substances. Influence on percutaneous absorption of indomethacin was investigated more in depth as this compound can serve as a model for other nonsteroid anti-inflammatory drugs. The 50 mmol/l concentration of urea (equal to uraemia) added to the gel ointment did not influence percutaneous absorption while 10% concentration of urea decreased percutaneous absorption of indomethacin approximately 5 times. Solubility of indomethacin increased in the presence of 10% urea in the gel more than two times. Elimination ratios Q0 were estimated to find if there is any effect on pharmacokinetics linked directly to the renal elimination. None of such changes were observed.

Percutaneous absorption of disopyramide, lidocaine and trimecaine

Promoting effect of cyclic monoterpenes on percutaneous absorption of antiarrythmics drugs disopyramide, lidocaine and trimecaine was investigated in the rats. Laurocapram (Azone) was used as a standard comparator of penetration enhancement. The absorption of trimecaine was significantly enhanced by addition of limonene, trans-p-menthane and Azone in 1% concentration. Lidocaine and disopyramide penetrated across the skin only when 1% of limonene was used. Other cyclic monoterpenes showed no effect on percutaneous absorption of examined drugs.

Xenopus Zic family and its role in neural and neural crest development

We characterized two new members of the Zic family, Xenopus Zic1 and Zic2. They are very similar to mouse Zic1 and Zic2 in the protein coding region including the zinc finger domain. In early gastrula, Zic1 expression was restricted to the prospective neural plate region whereas Zic2 was expressed widely in the ectoderm. We observed enhanced neural and neural crest-derived tissue formation in the Zic1 or Zic2 overexpressed embryos and neural and neural crest marker induction in the Zic1 or Zic2 overexpressed animal cap explants. Our findings suggest that Zic1 and Zic2 have essentially the same properties as Zic3 and that the Xenopus Zic family may act cooperatively in the initial phase of neural and neural crest development.

Identification of the Oka strain of the live attenuated varicella vaccine from other clinical isolates by molecular epidemiologic analysis

A method was developed to distinguish the Oka vaccine strain of varicella-zoster virus (VZV) from other clinical isolates. The molecular characteristics of 52 clinical isolates from varicella or zoster patients with no history of VZV vaccination and the Oka strain, including vaccine and parental viruses, were analyzed by PstI cleavage of the PstI site-less (PSL) region. This was followed by single-strand conformational polymorphism (SSCP) after polymerase chain reaction amplification of repeating region 2 (R2). Most of the clinical isolates tested, especially recent isolates, had a PstI site in the PSL region, but the Oka strain did not. The SSCP patterns of R2 in Oka strain virus differed from those of other viruses. These results suggest that analysis of the PstI site followed by SSCP of R2 will be useful for identifying the Oka vaccine virus in isolates.

Targeting of soybean-derived sterylglucoside liposomes to liver tumors in rat and mouse models

The blood clearance, tissue uptake and antitumor efficacy against liver metastasis of M5076 reticulosarcoma in mice and against primary liver cancer in rats of doxorubicin (DOX) encapsulated in two types of liposomes, with and without a soYbean-derived sterylglucoside mixture (SG), were examined. Liposomes entrapping DOX were composed of dipalmitoylphosphatidylcholine (DPPC), SG and cholesterol (Ch) at a molar ratio of 6:1:3, (SG-liposomes) and 6:0:4 (non-SG-liposomes). Pharmacokinetic analysis of drug disposition was based on the area under the curve (AUC) for liposomes up to 24 h following i.v. injection. SG-liposomes showed lower DOX concentrations in blood and higher concentrations in liver compared with non-SG-liposomes. The highest AUC of SG-liposomes in tissue was in liver, 2.4 times higher than that of the free drug. The antitumor efficacy of SG-liposomes was compared with that of free DOX and non-SG-liposomes at a dose of 5 mg DOX/kg. SG-liposomes displayed stronger antitumor activity than the free drug and non-SG-liposomes in murine reticulosarcoma M5076 tumor models and primary liver cancer models reflecting accumulation in hepatocytes. The antitumor activity of SG-liposomes in rats with primary liver cancer was significantly higher compared with free DOX and non-SG-liposomes (ILS: 92.7%).

A case of Kearns-Sayre syndrome showing a constant proportion of deleted mitochondrial DNA in blood cells during 6 years of follow-up

Kearns-Sayre syndrome (KSS) and Pearson syndrome (PS) show quite different phenotypes despite the same underlying genetic defect, i.e. a large deletion of one population of mitochondrial (mt) DNA. The main feature of KSS is progressive encephalomyopathy; on the other hand, PS shows fatal hematological problems in early infancy. Through Southern blot analysis of mtDNA of blood cells, deletion has been consistently found in patients with PS but usually undetectable in KSS patients. Therefore, their different clinical phenotypes have been explained by the different tissue distribution of mutant mtDNA. Recently, a few cases were reported which had features of PS in infancy and later developed KSS. These observations suggest that phenotypes may also be modified by the selection process involving mtDNA within different tissues. We found a case of KSS, who initially presented endocrinological dysfunction such as insulin-dependent diabetes mellitus (IDDM) and growth hormone (GH) deficiency, and had not developed external ophthalmoplegia until the age of 17. Although he did not show any symptoms of PS, a marked proportion of mtDNA was deleted not only in muscle but also in blood cells. Analysis of his blood cells showed an unchanged proportion of deleted mtDNA at three estimations within 6 years of the follow-up period. This case provides evidence that deleted mtDNA in blood cells also has a stable replicative capacity and that a large proportion of deleted mtDNA in blood cells may not accompany hematological problems.

A case of craniofacial dysmorphism, congenital heart defects, coccygeal skin folds, generalized skeletal alterations, and hemihypertrophy with linear skin hypopigmentation: a new syndrome?

The case of a Japanese girl with a unique combination of congenital malformations is reported. The malformations include craniofacial dysmorphism, congenital heart defects, coccygeal skin folds, generalized skeletal alterations, and hemihypertrophy with linear skin hypopigmentation that indicated somatic mosaicism of a mutated gene or a submicroscopic chromosomal aberration. The phenotype in our patient overlapped significantly with, but was not completely consistent with, that of ter Haar syndrome, a recently elucidated malformation syndrome with an autosomal recessive trait. The present patient may have represented a previously undescribed malformation syndrome, or an atypical manifestation of ter Haar syndrome due to somatic mosaicism.

Diabetes mellitus accompanied by nonocclusive colonic ischemia

A 70-year-old man with diabetic triopathy was hospitalized with left lower quadrant abdominal pain and tenderness, muscle guarding and absent bowel sounds. Three hours after admission, creatine phosphokinase (CPK) was elevated and an abdominal plain film X-ray showed intestinal gas retention, indicating paralytic ileus due to inferior mesenteric artery occlusion. Urokinase (60,000 units/day) and heparin (10,000 units/day) were administered. Angiography showed no occlusion in the mesenteric artery. On the 16th day, the abdominal signs had disappeared and CPK was normalized. We diagnosed this case as nonocclusive colonic ischemia because of the hemorheological abnormalities due to diabetic triopathy and the hypercoagulable state.

In vivo anti-influenza virus activity of Kampo (Japanese herbal) medicine "sho-seiryu-to"--stimulation of mucosal immune system and effect on allergic pulmonary inflammation model mice

When BALB/c mice were treated with a Kampo (Japanese herbal) medicine "Sho-seiryu-to (SST)" (1 g/kg, 10 times) orally from 7 days before to 5 days after the infection and infected with mouse-adapted influenza virus A/PR/8/34 by nasal-site restricted infection, SST caused increment of the influenza virus hemagglutinin-specific IgA antibody secreting cells in nasal lymphocyte but not in Peyer's patch lymphocyte at 6 days after infection in comparison with water-treated mice. Oral administration of SST also augmented IL-2 receptor beta chain+ (activated) T-cell in Peyer's patch lymphocyte, but not in the nasal lymphocyte. We previously reported that SST showed potent anti-influenza virus activity through augmentation of the antiviral IgA antibody titer in the nasal and broncho-alveolar cavities of the mice (T. Nagai and H. Yamada, 1994, Int. J. Immunopharmacol. 16, 605-613). These results suggest that oral administration of SST shows anti-influenza virus activity in the nasal cavity by activation of T-cell in Peyer's patch lymphocyte and stimulation of production of anti-influenza virus IgA antibody in nasal lymphocyte. When ovalbumin-sensitized allergic pulmonary inflammation model mice were administered orally with SST (1 g/kg) from 8 days before (11 times) or from 2 h after (4 times) to 4 days after the infection and infected with mouse-adapted influenza virus A/PR/8/34, replications of the virus in the both nasal and broncho-alveolar cavities or only nasal cavity were significantly inhibited at 5 days after infection in comparison with water-treated control by augmenting antiviral IgA antibody, respectively. These results suggest that SST is useful for both prophylaxis and treatment of influenza virus infection on patients with allergic pulmonary inflammation, such as bronchial asthma.

Role of carboxyl residues surrounding heme of human cytochrome b5 in the electrostatic interaction with NADH-cytochrome b5 reductase

To identify the cytochrome b5 residues responsible for the electrostatic interaction with NADH-cytochrome b5 reductase (b5R), we prepared and characterized the cytochrome b5 mutants in which Glu41, Glu42, Glu63, Asp70, and Glu73 were replaced by Ala, utilizing site-directed mutagenesis and the expression system for cytochrome b5 in Escherichia coli. Apparent Km values of the wild type b5R for Glu42Ala cytochrome b5 and Asp70Ala cytochrome b5 were approximately three-fold and six-fold higher than that for the wild type cytochrome b5, respectively, while the kcat values for those mutants were not remarkably affected. In contrast, Glu41Ala, Glu63Ala, and Glu73Ala cytochrome b5 showed almost the same kinetic properties as the wild type cytochrome b5. Furthermore, kinetic studies on combinations of the cytochrome b5 and b5R mutants suggested the interaction between Glu42 and Asp70 of cytochrome b5 and Lys125 and Lys41 of b5R, respectively, in the reaction.

Electrostatic interaction between NADH-cytochrome b5 reductase and cytochrome b5 studied by site-directed mutagenesis

Electrostatic interaction between NADH-cytochrome b5 reductase and cytochrome b5 was studied by site-directed mutagenesis. The target residues for mutagenesis were selected on the basis of the previously reported chemical cross-linking study of these two proteins, which implicated possible charge-pair interactions between Lys-41, Lys-125, Lys-162, and Lys-163 of the enzyme, and Glu-47, Glu-48, Glu-52, Glu-60, Asp-64 (group A), and heme propionate of cytochrome b5. Mutant reductases that lost one of the above-listed Lys residues showed higher K(m) values for cytochrome b5 and lower kcat values than those of the wild type, suggesting that all of the examined Lys residues participate in binding with cytochrome b5 as reported previously. In contrast, a removal of one of (or even all of) the group A residues from cytochrome b5 by mutagenesis caused no significant effect on the catalytic properties of cytochrome b5. Additional elimination of another set of negative residues (Glu-41, Glu-42, Asp-57, and Glu-63 (Group B)), which are also located close to heme, elevated the K(m) value by more than five folds. These results suggest that there should be other acidic residue(s) than group A in cytochrome b5 which participate in binding with NADH-cytochrome b5 reductase.

Roles of chemical mediators in the taste system

Recent advances in neural mechanisms of taste are reviewed with special reference to neuroactive substances. In the first section, taste transduction mechanisms of basic tastes are explained in two groups, whether taste stimuli directly activate ion channels in the taste cell membrane or they bind to cell surface receptors coupled to intracellular signaling pathways. In the second section, putative transmitters and modulators from taste cells to afferent nerves are summarized. The candidates include acetylcholine, catecholamines, serotonin, amino acids and peptides. Studies favor serotonin as a possible neuromodulator in the taste bud. In the third section, the role of neuroactive substances in the central gustatory pathways is introduced. Excitatory and inhibitory amino acids (e.g., glutamate and GABA) and peptides (substance P and calcitonin gene-related peptide) are proved to play roles in transmission of taste information in both the brainstem relay and cortical gustatory area. In the fourth section, conditioned taste aversion is introduced as a model to study gustatory learning and memory. Pharmacobehavioral studies to examine the effects of glutamate receptor antagonists and protein kinase C inhibitors on the formation of conditioned taste aversion show that both glutamate and protein kinase C in the amygdala and cortical gustatory area play essential roles in taste aversion learning. Recent molecular and genetic approaches to disclose biological mechanisms of gustatory learning are also introduced. In the last section, behavioral and pharmacological approaches to elucidate palatability, taste pleasure, are described. Dopamine, benzodiazepine derivatives and opioid substances may play some roles in evaluation of palatability and motivation to ingest palatable edibles.

In vivo antiinfluenza virus activity of Kampo medicine Sho-seiryu-to through mucosal immune system

The Kampo (Japanese herbal) medicine, Sho-seiryu-to, which has traditionally been used for the treatment of colds and bronchial asthma, showed potent antiinfluenza A and B virus activity through augmentation of production of antiviral IgA antibody in the nasal and bronchoalveolar cavities of mice when administrated orally before viral infection. Sho-seiryu-to also showed antiinfluenza virus activity against A virus H1N1 subtype infected in aged mice (approximately 6 months old) with an increase of antiviral IgA antibody in the bronchoalveolar wash of the treated mice by similar administration. When mice infected with mouse nonadapted influenza A virus H3N2 subtype before 14 days were secondarily infected with mouse adapted A/PR/8 (H1N1) virus and administered Sho-seiryu-to orally after the second infection, replication of the virus in both nasal and bronchoalveolar cavities was significantly inhibited. Sho-seiryu-to had no effect on the mice which were not primed with mouse nonadapted virus when administered after the infection of mouse-adapted A/PR/8 virus. Oral administration of Sho-seiryu-to caused increment of viral-specific IgA antibody secreting cells in mouse nasal lymphocyte. Sho-seiryu-to also augmented IL-2 receptor beta chain+ T-cells in Peyer's patch of the infected mice. Sho-seiryu-to also significantly reduced viral titer in the nasal washes of the infected ovalbumin-sensitized bronchial asthma model mice. Oral administration of Sho-seiryu-to before and after vaccination significantly augmented hemagglutination-inhibiting antibody in the serum by nasal inoculation of influenza HA vaccine, and significantly augmented nasal antiviral IgA antibody and bronchoalveolar and serum antiviral IgG antibodies even after secondary vaccination although induction of antiviral antibody by intranasal vaccination was insufficient without Sho-seiryu-to. These results suggest that Sho-seiryu-to is able to prevent influenza virus infection by cross-protection of subtypes of influenza A virus and B virus. Sho-seiryu-to is also useful for the treatment of influenza virus infection in hosts with a history of influenza virus infection and/or influenza vaccination and allergic pulmonary inflammation, such as bronchial asthma, and can be used as an adjuvant to nasally inoculated influenza HA vaccine.

Uptake and release of neurotransmitter candidates, [3H]serotonin, [3H]glutamate, and [3H]gamma-aminobutyric acid, in taste buds of the mudpuppy, Necturus maculosus

Neurotransmitters in vertebrate taste buds have not yet been identified with confidence. Serotonin, glutamate, and gamma-aminobutyric acid (GABA) have been postulated, but the evidence is incomplete. We undertook an autoradiographic study of [3H]serotonin, [3H]glutamate, and [3H]GABA uptake in lingual epithelium from the amphibian, Necturus maculosus, to determine whether taste bud cells would accumulate and release these substances. Lingual epithelium containing taste buds was incubated in low concentrations (0.4-6 microM) of these tritiated transmitter candidates and the tissue was processed for light microscopic autoradiography. Merkel-like basal taste cells accumulated [3H]serotonin. When the tissue was treated with 40 mM K+ after incubating the tissue in [3H]serotonin, cells released the radiolabelled transmitter. Furthermore, depolarization (KCl)-induced release of [3H]serotonin was Ca-dependent: if Ca2+ was reduced to 0.4 mM and 20 mM Mg2+ added to the high K+ bathing solution, Merkel-like basal cells did not release [3H]serotonin. In contrast, [3H]glutamate was taken up by several cell types, including non-sensory epithelial cells, Schwann cells, and some taste bud cells. [3H]glutamate was not released by depolarizing the tissue with 40 mM K+. [3H]GABA uptake was also widespread, but did not occur in taste bud cells. [3H]GABA accumulated in non-sensory epithelial cells and Schwann cells. These data support the hypothesis that serotonin is a neurotransmitter or neuromodulator released by Merkel-like basal cells in Necturus taste buds. The data do not support (nor rule out) a neurotransmitter role for glutamate or GABA in taste buds.