Effects of the inhibition of intestinal P-glycoprotein on aliskiren pharmacokinetics in cynomolgus monkeys

Aliskiren is a substrate for P-glycoprotein (P-gp) and is metabolized via cytochrome P450 3A4 (CYP3A4). The aim of the present study was to assess whether P-gp influenced the pharmacokinetics of aliskiren and also if drug-drug interactions (DDIs) mediated through P-gp could be reproduced in cynomolgus monkeys. The study investigated the pharmacokinetics of aliskiren in mdr1a/1b gene-deficient (P-gp KO) and wild-type (WT) mice. The area under the plasma concentration-time curve (AUC) following the oral administration of aliskiren was 6.9-fold higher in P-gp KO mice than in WT mice, while no significant differences were observed in the AUC or total plasma clearance following the intravenous administration of aliskiren to P-gp KO mice. Then the pharmacokinetics of aliskiren were evaluated and DDIs between aliskiren and P-gp inhibitors, such as cyclosporin A (CsA) and zosuquidar, examined in cynomolgus monkeys. The AUC for aliskiren were 8.3- and 42.1-fold higher after the oral administration of aliskiren with the concomitant oral administration of zosuquidar and CsA at doses of 10 and 30 mg/kg, respectively. In contrast, the AUC after the intravenous and oral administration of aliskiren was not significantly affected by the oral administration of zosuquidar or intravenous administration of CsA, respectively. These results indicated that P-gp strictly limited the intestinal absorption of aliskiren in mice and monkeys, and also that the effects of intestinal P-gp inhibition by CsA or zosuquidar on the pharmacokinetics of aliskiren were sensitively reproduced in monkeys. In conclusion, aliskiren can be used as a sensitive substrate to evaluate intestinal P-gp inhibition in monkeys.

Biogeochemical signals from deep microbial life in terrestrial crust

In contrast to the deep subseafloor biosphere, a volumetrically vast and stable habitat for microbial life in the terrestrial crust remains poorly explored. For the long-term sustainability of a crustal biome, high-energy fluxes derived from hydrothermal circulation and water radiolysis in uranium-enriched rocks are seemingly essential. However, the crustal habitability depending on a low supply of energy is unknown. We present multi-isotopic evidence of microbially mediated sulfate reduction in a granitic aquifer, a representative of the terrestrial crust habitat. Deep meteoric groundwater was collected from underground boreholes drilled into Cretaceous Toki granite (central Japan). A large sulfur isotopic fractionation of 20–60‰ diagnostic to microbial sulfate reduction is associated with the investigated groundwater containing sulfate below 0.2 mM. In contrast, a small carbon isotopic fractionation (<30‰) is not indicative of methanogenesis. Except for 2011, the concentrations of H₂ ranged mostly from 1 to 5 nM, which is also consistent with an aquifer where a terminal electron accepting process is dominantly controlled by ongoing sulfate reduction. High isotopic ratios of mantle-derived ³He relative to radiogenic ⁴He in groundwater and the flux of H₂ along adjacent faults suggest that, in addition to low concentrations of organic matter (<70 µM), H₂ from deeper sources might partly fuel metabolic activities. Our results demonstrate that the deep biosphere in the terrestrial crust is metabolically active and playing a crucial role in the formation of reducing groundwater even under low-energy fluxes.

Phenotypes of CCAAT/enhancer-binding protein beta deficiency: hyperdontia and elongated coronoid process

OBJECTIVES

This investigation aimed to conduct a case-control study of mandibular morphology and dental anomalies to propose a relationship between mandibular/dental phenotypes and deficiency of CCAAT/enhancer-binding protein beta (CEBPB).

MATERIALS AND METHODS

Skulls of CEBPB(-/-), CEBPB(+/-) and CEBPB(+/+) mice were inspected with micro-computed tomography. Mandibular morphology was assessed with a method of Euclidean distance matrix analysis.

RESULTS

Elongation of the coronoid process was identified in CEBPB(+/-) (P ≤ 0.046) and CEBPB(-/-) 12-month-olds (P ≤ 0.028) but not in 14-day-olds (P ≥ 0.217) and 0-day-olds (P ≥ 0.189) of either genotype. Formation of supernumerary teeth in CEBPB(-/-) adult mice was demonstrated (χ(2) = 6.00, df = 1, P = 0.014).

CONCLUSIONS

CEBPB deficiency was related to elongation of the coronoid process and formation of supernumerary teeth. The mandibular and dental phenotypes of CEBPB deficiency were unseen by the 14th day after birth. Future investigations into the influence of CEBPB on mandibular and dental development are needed.

Low-Temperature-Adapted Influenza A2/AA/6/60 Virus Vaccine in Man

Volunteers inoculated nasopharyngeally with liver A2/AA/6/60 virus grown in primary bovine kidney cell cultures at 25 C were asymptomatic but developed significant serum and respiratory secretory antibody responses. Viruses were not recovered from these volunteers who had a low or moderate level of prevaccination antibody titers.

[A case of peripelvic extravasation related to pregnancy]

A 35-year-old woman was hospitalized at 39 weeks 0 days of gestation because of acute left flank pain. Magnetic resonance imaging (MRI) revealed bilateral hydronephrosis with peripelvic extravasation of contrast material around the left kidney. The pregnancy ended with a cesarean section and after the cesarean section a left double-J-stent was placed cystoscopically. An excretory urogram following the removal of the ureteral stent showed no extravasation or hydronephrosis in either kidney.

N-[[1-(2-phenylethyl)pyrrolidin-2-yl]methyl]cyclohexanecarboxamides as selective 5-HT1A receptor agonists

A series of benzamides was synthesized as selective agonists for the 5-HT1A receptor. It was found that (S)-N-[[1-(2-phenylethyl)pyrrolidin-2-yl]methyl]cyclohexanecarb oxamide(7-(S)) has potent and selective agonistic activity for the 5-HT1A receptor (5-HT1A; Ki 0.49 nmol/L, D2; IC50 = >1000 nmol/L, 5-HT2; Ki = 240 nmol/L).

First pass metabolism and in vitro metabolism of a new orally active dopamine prodrug, N-(N-acetyl-L-methionyl)-O,O-bis(ethoxycarbonyl)dopamine in dogs

To elucidate the first pass metabolism of the dopamine prodrug N-(N-acetyl-L-methionyl)-O,O-bis(ethoxycarbonyl)dopamine (TA-870) in the small intestine and liver of dogs, the blood and plasma concentrations of unchanged TA-870 and metabolites in the gastroduodenal vein, portal vein, hepatic vein, and abdominal aorta were measured by HPLC after intraduodenal administration of TA-870. In addition, an in vitro metabolic study of TA-870 was carried out using liver, small intestinal wall, and blood homogenates of dogs. The order of maximal concentration (Cmax 0-30 min) in gastroduodenal blood or plasma was unchanged TA-870 greater than deethoxycarbonylated TA-870 (DEC-TA-870) greater than conjugated dopamine greater than free dopamine (DA) greater than free homovanillic acid (HVA) greater than free 3,4-dihydroxyphenylacetic acid (DOPAC). This result showed that the main pathway of metabolism in the small intestine is catechol ester hydrolysis and minor pathways are amido hydrolysis, oxidative deamination, and catechol 3-O-methylation. The order of Cmax in the hepatic vein and abdominal aorta was conjugated DA greater than free DEC-TA-870 greater than free HVA greater than free DA greater than free DOPAC greater than conjugated DOPAC greater than unchanged TA-870. The main metabolic pathways in the liver were hydrolyses of ester and amido-linkage of TA-870 and conjugation of DA. In the in vitro studies, the main metabolites of TA-870 in liver, small intestinal wall, and blood homogenates were DEC-TA-870, 3- or 4-mono-deethoxycarbonylated TA-870, DA, and an unknown compound.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical evaluation of prophylactic intranasal 1-phenyl-3-(4-phenyl-2-thiazolyl) guanidine (CL 88,277) medication against rhinovirus 44 challenge

The prophylactic intranasal medication with a new antiviral compound, 1-phenyl-3-(4 phenyl-2-thiazolyl) guanidine (CL 88,277) was evaluated in humans against rhinovirus 44 challenge. One ml containing 250 mg of CL 88,277 was administered to 10 seronegative volunteers three times a day plus one dose prior to the rhinovirus challenge (32 TCID 50) and for six consecutive post-challenge days. Ten other subjects received 56% polyethylene glycol (PEG-400), the solvent of CL 88,277 at the same time. Five subjects in each of the CL 88,277-treated and placebo-treated groups developed illness. There were no differences between the two groups in the occurrence of the severe illness and of the moderate and severe illnesses. Each sign and symptom occurred almost equally in the two groups and there was no difference in their scores between the two groups. The challenge virus was isolated from both groups but the total number of the virus isolates was less and the time span of virus excretion was shorter for the drug-treated group. The post-challenge serum antibody titers were markedly lower in the drug-treated group. Prophylactic intranasal CL 88,277 medication did not affect the course of illness induced by rhinovirus 44 challenge. It appears, however, that the virus replication in the nose was reduced and as a result the serum antibody response was diminished. PEG-400 caused a transient irritation of the nasal mucosa in all recipients.

Clinical and serologic effects of live attenuated serum inhibitor-resistant influenza B vaccine in seronegative adults

The clinical effects, nasal and serum antibody responses, and virus excretion of a live attenuated serum inhibitor-resistant influenza B virus vaccine, R75, was evaluated in 43 seronegative healthy adults by a random double-blind study. Symptom responses were minimal and were not significantly different between vaccine and placebo groups. No fevers, abnormalities in physical examination or laboratory testing developed during 4 weeks of observation. Among vaccinees, 10 (48%) developed serum hemagglutination-inhibition (HI) antibodies, 16 (76%) developed serum neutralization (N) antibodies and 4 (19%) developed nasal N antibodies. The GMT responses from study day 0 to day 28 were 4.0 to 10.4 for serum HI, 1.8 to 9.8 for serum N, and 1.0 to 1.4 for nasal N. There were no significant titer changes in the placebo group. No virus excretion was detected. Although there are some questions concerning the relationship of antibody levels to protection, the low antibody responses in this study are an indication that R75 is not sufficiently immunogenic.

The effects of intramyometrial injection of prostaglandin F2alpha on severe post-partum hemorrhage

Effectiveness of prostaglandin F2alpha (PGF2alpha) in controlling postpartum uterine hemorrhage was evaluated with the following results. (1) Systemic administration, whether by continuous i.v. infusion or by gluteal i.m. injection, was not a completely adequate method for hemostasis. (2) Local administration by directly injecting into the uterine musculature, whether transabdominally or transvaginally, resulted in a dramatic reduction of the rate of bleeding. Routine clinical application of the direct intramyometrial injection of PGF2alpha for severe post-partum hemorrhage is recommended in view of its easy performance, excellent hemostatic effect, minimal side effects and good prognosis.

Double-blind clinical assessment of ribavirin (virazole) in the prevention of induced infection with type B influenza virus

The prophylactic effectiveness of oral administration of ribavirin (1-beta-D-ribofuranosyl-1,24-triazole-3-carboxamide, virazole) against artificially induced influenza B infection was evaluated in a double-blind clinical trial. Fifteen seronegative men received ribavirin capsules (600 mg/day in three divided doses), and 15 other men received placebo capsules two days before the inoculation of 6.4 X 10(4) 50% tissue culture infective doses of influenza virus B/Georgia/26/74 and for eight days after challenge. Ten men (69%) in each of the two groups developed mild to severe influenzal illness. Of these, five placebo-treated men developed severe febrile illness, while only one drug-treated man had illness of comparable severity. Illness of moderate severity was observed in three placebo-treated conrols and two drug recipients. There was no difference between the frequencies of isolation of virus or the anitbody responses in the two groups. Ribavirin suppressed signs and symptoms induced by influenza B challenge, but its effectiveness was marginal.

Comparative clinical and laboratory evaluation of the prophylactic capacity of ribavirin, amantadine hydrochloride, and placebo in induced human influenza type A

The comparative prophylactic effectiveness of oral treatment with ribavirin (1-beta-D-ribofuranosyl-1,2,4,triazole-3-carboxamide; virazole) and amantadine hydrochloride against artificially induced infection with influenza A virus was evaluated in 29 seronegative men who received ribavirin capsules (200 mg) three times daily, placebo capsules three times daily, or amantadine capsules (100 mg) twice daily. Medication was started two days before the inoculation of 2 X 10(4) 50% tissue culture infective doses of A University of Maryland/2/74 (H3N2) influenza virus and was continued for eight days after challege. Nine of the 10 subjects who received ribavirin, eight of the nine subjects who received placebo, and six of the 10 subjects who received amantadine developed influenzal illness. Significantly less virus was isolated from the amantadine-treated group than from the placebo-treated or the ribavirin-treated group. Antibody responses of the ribavirin-treated and placebo-treated groups were quite similar to each other; however, prophylactic treatment with amantadine significantly reduced titers of serum antibody and febrile responses. In a separate clinical trial involving challenge with A/Dunedin/73 (H3N2) influenza virus, ribavirin also failed to show prophylactic effectiveness.

Clinical studies with the Cendehill strain of attenuated rubella vaccine

The Saccharomyces cerevisiae killer factor glycoproteins killed the pathogen Torulopsis glabrata by a mechanism involving membrane damage. Some other yeast species were unaffected by these glycoprotein toxins.

Clinical and serologic effects of Alice strain live attenuated influenza A (H3N2) virus vaccine in an adult population

Alice strain live attenuated influenza A (H3N2) virus was evaluated in prison volunteers. By random double blind allocation, 94 volunteers received Alice strain vaccine (AS) intranasally and 97 received placebo. The vaccine was well tolerated, and there was no serious morbidity. The number, type, duration, and severity of symptoms was not significantly different between the vaccine and placebo groups. Seventy-five per cent of vaccines with initial HAI titers less than or equal to 1:8 had 4 fold or greater titer responses on day 30. Placebo recipients experienced no titer changes. The GMT among vaccinees increased from 23.5 prior to vaccination 59.7 30 days later. Surveillance activities failed to document influenza A (H3N2) infection in the volunteer population during a 6 month follow-up period. Additional studies on the protective effects of the vaccine are required before efficacy can be determined.

Alice strain live attenuated influenza (H3N2) vaccin in an elderly population

The clinical and antibody responses to Alice strain (AS) live attenuated influenza A (H3N2) vaccine and killed parenteral (KP) bivalent influenza vaccine were compared in a randomly allocated group of 150 elderly volunteers. AS recipients experienced more symptoms but these were mild and short in duration. Rhinitis occurred in 45% and pain at injection site in 25% of the AS and KP groups, respectively. Influenza A (H3N2) serum hemmaglutination inhibition titer responses were significantly higher in KP vaccinees; 95% of KP AND 60% OF AS recipients with initial titers smaller than or equal to 1:16 had fourfold or greater titer rises. KP induced significantly higher nasal neutralization titers but the proportion with fourfold or greater responses was not significantly different. Previous studies have shown poor correlations between antibody levels induced by live influenza vaccines and protection. Natural and/or challenge studies are needed before efficacy of influenza vaccines can be established.

Mode of action of colistin

The prophylactic efficacy of isoprinosine was evaluated in a double-blind fashion in volunteers challenged with two types of rhinovirus. In the rhinovirus 44 and 32 trials, each of 9 men received a placebo, and eight and 11 men received the drug, respectively. Oral isoprinosine, 6 g a day, was given for 2 days prior to intranasal challenge with 100 mean tissue culture infective doses of the virus and for 7 postchallenge days. In both trials the occurrence and severity of colds were greater in the placebo group, but the difference between the two groups was not significant. Higher antibody titers for both viruses and a greater number of rhinovirus 32 isolations were demonstrated in the drug group but without statistically significant differences. The prophylactic isoprinosine treatment may suppress the cold syndrome, but its effect was not convincingly apparent.

Antiviral effect of 3, 4-dihydro-1-isoquinolineacetamide hydrochloride in experimental human rhinovirus infection

Double-blind trials were conducted in volunteers to evaluate the efficacy of the prophylactic 3,4-dihydro-1-isoquinolineacetamide hydrochloride (DIQA) treatment against rhinovirus type 24 challenge. Ten men received a 7-day course of DIQA treatment and 11 men received a placebo. The intranasal viral challenge dose was 10 mean tissue culture infective doses. The oral administration of 1 g prechallenge and 2 g a day for 6 consecutive postchallenge days did not prevent the development of colds. Nine drug-treated men and 10 controls developed rhinovirus illness. However, the illnesses of the drug-treated men were mild. Rhinorrhea occurred less frequently and was more mild in the drug-treated group. The challenge virus was recovered from 80% of these subjects in both groups, but almost twice the number of challenge viruses were isolated from the controls than from the drug-treated men. The prophylactic DIQA therapy appears to suppress the cold syndrome and to reduce virus excretion, although its effect is marginal. Additional clinical trials are warranted to confirm the antirhinoviral effect of this drug.

In vitro effect of virazole against influenza viruses

The minimal inhibitory concentrations of Virazole against 32 mean tissue culture infective doses of three type A influenza strains including type A/England/42/72 (H3N2) and a type B strain in tissue culture were 0.1 and 0.05 mug/ml, respectively. The growth inhibition pattern by various Virazole concentrations of type A virus was similar to that of the type B virus. Virazole appears to be slightly more potent against the A/England/42/72 strain than are other antiinfluenzal agents.

Mucociliary function during experimentally induced rhinovirus infection in man

In conjunction with a controlled study of the effect of vitamin C on susceptibility to experimentally induced rhinovirus infections in man, we have conducted a study of nasal mucociliary function in the subjects volunteering for the study. In the 21 volunteers an average mucociliary flow rate (measured by the Quinlan tagged particle technique) of 7.5 mm/min was found in those with normal nasal morphology and 4.0 mm/min in those with abnormal nasal morphology. The rates decreased during infection in both groups but at different times after induction of infection. Ascorbic acid had no effect on either susceptibility to induced rhinovirus infection or mucociliary transport.

Evaluation of amantadine hydrochloride in the treatment of A2 influenzal disease

Amantadine hydrochloride is the first drug to show promise as a practical anti-influenza agent. Several studies demonstrating a prophylactic effect in volunteers with induced A2 disease as well as in patients during A2 outbreaks have created the impetus for therapeutic trials. The widespread A2 influenza epidemic that occurred early in 1968 provided the opportunity for therapeutic evaluation in the USA.A total of 197 prison inmates with proven influenza agreed to participate in the 10-day double-blind evaluation of amantadine (100 mg, twice daily). Onset of therapy was approximately 20 hours after first subjective awareness of illness.Assessment of drug effectiveness was based on rapidity of resolution of illness. There was a significant increase in the number of drug-treated as against placebo patients in the "rapid resolver" group whereas individuals receiving placebo dominated the "slow resolver" group. Analysis of febrile responses indicated that amantadine-treated patients had significantly more rapid defervescence. Virus isolation studies revealed etiologically related virus in 90% of all volunteers during the first 5 days of therapy. It was apparent that clinical improvement was not correlated with disappearance of the virus. Nevertheless, the trials conducted during the influenza season of early 1968 indicated the therapeutic effect of amantadine hydrochloride. Administration of 100 mg, twice daily, for 10 days did not cause any adverse effects.

Antibody Response in Respiratory Secretions of Volunteers Given Live and Dead Influenza Virus

The nature of the neutralizing antibody response in respiratory secretions to influenza virus has been compared in two groups of human volunteers, one given live virus via the respiratory tract and the other given dead virus parenterally. The “live-virus group” showed an antibody response in sputum and nasal washing that was significantly greater in magnitude and longer in duration than it was in the “dead-virus group.” There was no difference in the antibody response in saliva. In volunteers who were inoculated with live virus but showed no serum antibody rise, there was, nevertheless, a rise in sputum or nasal washing antibody. These results indicate that local infection is superior to parenteral immunization in inducing antibody in respiratory secretions.