The antiviral activity of isatin beta-thiosemicarbazone derivatives on vaccinia virus infection in mice

Newly synthetized compounds of Mannich bases isatin-beta-thiosemicarbazone derivatives: N,N'-bis-(beta-thiosemicarbazone-isatinmethyl)-2-methylpiperazine (TSKI-VI); N,N'-bis (beta-thiosemicarbazoneisatinmethyl)-cis-2,5-dimethylpiperazine (TSKI-VII) and N,N'-bis (beta-thiosemicarbazoneisatinmethyl)-trans-2,5-dimethylpiperazine (TSKI-VII), showed protective effect on mice infected i.c. with neurovaccinia virus. Antiviral activity was shown already at doses of 1-25 mg/kg increased with the concentrations of the administratered compounds. TSKI-VI given prophylactically also showed protective effect, similar to metisazone in mice later infected i.c. with vaccinia virus.     

Synthesis and aldose reductase inhibitory activity of benzoyl-amino acid derivatives

Discoid lupus erythematosus (DLE) is an uncommon disease in childhood. We present two patients initially diagnosed as impetigo and photosensitive eczema with impetigo, respectively, who failed to respond to topical and systemic antistaphylococcal agents and in whom a diagnosis of discoid lupus erythematosus subsequently became apparent.     

Synthesis of 5-substituted quinazolinone derivatives and their inhibitory activity in vitro

Quinazolinone derivatives I and their methyl esters were synthesized and evaluated as nonclassical lipophilic inhibitors of thymidylate synthase. Compounds Ib and Ic containing OH and CO2H as R substituents, respectively, were most effective, indicating that hydrogen bonding may contribute to the increased inhibitory activity. These compounds further showed high cytotoxic activity against tumor cells in culture.     

Effect of dual-subtype vaccine against feline immunodeficiency virus infection

Dual-subtype feline immunodeficiency virus (FIV) vaccine, consisting of inactivated cells infected with subtypes A (Petaluma strain) and D (Shizuoka strain), was developed and tested for its vaccine efficacy against FIV infection in specific pathogen free (SPF) cats. Animals were monitored for proviral DNA by FIV-specific PCR and for FIV-specific antibody profiles by ELISA and virus-neutralization assays. In addition, blood from challenged cats was inoculated into naive SPF cats to confirm the viral status of the vaccinated cats. All cats immunized with Petaluma vaccine alone were protected against homologous Petaluma challenge, but only one of four cats was protected against heterologous Shizuoka challenge. More importantly, all cats immunized with the dual-subtype vaccine were protected against both Petaluma and Shizuoka challenges. These results suggest that a multi-subtype vaccine approach may provide the broad-spectrum immunity necessary for vaccine protection against strains from different subtypes.     

Relationship between structure and inhibitory effect of arginine analogues on neuronal nitric oxide synthase activity

2,3,5-Trimethyl-6-(3-pyridylmethyl)1,4-benzoquinone (CV-6504), an inhibitor of 5-lipoxygenase and thromboxane A2 synthase and a scavenger of active oxygen species, has been shown to exhibit profound anti-tumour activity against three established murine adenocarcinomas (MACs) that are generally refractory to standard cytotoxic agents. For the cachexia-inducing MAC16 tumour, optimal anti-tumour activity was seen at dose levels of 10 and 25 mg kg-1 day-1, together with a reversal of cachexia and a doubling of the time to sacrifice of the animals through cachexia from 8 days to 17 days. The remaining tumour fragments showed extensive necrosis in regions distal from the blood supply. Growth of the MAC13 tumour was also effectively suppressed at dose levels between 5 and 50 mg kg-1 day-1, resulting in a specific growth delay between 1.0 and 1.2. Growth of the MAC26 tumour was also inhibited a concentration-related manner, with doses of 25-50 mg kg-1 day-1 being optimal. Anti-tumour activity towards all three tumours at low dose levels of CV-6504 was effectively suppressed by concurrent administration of linoleic acid (1 g kg-1 day-1), suggesting that inhibition of linoleate metabolism was responsible for the anti-tumour effect. Tumour sensitivity may be correlated with increased DT-diaphorase that are required to metabolise CV-6504 to the active hydroquinone, which inhibits 5-lipoxygenase activity.     

Synthesis of adenine derivatives and their activities against herpes virus in vitro

A series of 9-(N4-substituted acetaldehyde thiosemicarbazone) adenines were synthesized and evaluated for antiherpes virus activity. Compounds 4a-l were prepared by condensation of 9-(acetaldehyde) adenine(6) and the corresponding N4-substituted thiosemicarbazides (10). The antiviral effects of all compounds 4a-l were tested in vitro in primary rabbit kidney cell cultures infected with herpes simplex virus type 1 (HSV-1) and varicella-herpes zoster virus (VZV), and in primary human embryo cell cultures infected with herpes simplex virus type 2 (HSV-2). The results showed that the minimum inhibitory concentrations (MIC) of 4e and 4f for HSV-1 and VZV were 20, 40, 20 and 20 micrograms.ml-1, respectively, and other compounds were 200 micrograms.ml-1. For HSV-2, the MIC of all tested compounds were 300 micrograms.ml-1. We also evaluated the antiherpetic effect of 4e (and 4f) by combination with acyclovir (ACV) in the ratio of 1:1 in vitro. The MIC of the combined compounds were 2 micrograms.ml-1 for 4e and 6 micrograms.ml-1 for 4f, while their minimum cytotoxicities (MCC) in the cell were markedly reduced compared with the individual compounds.     

Antimicrobial activity of newly synthesized isothiocyanate derivatives against pathogenic plant microorganisms

Fifteen reaction products of isothiocyanates with cysteine, seven reaction products of isothiocyanates with 2,3-dimercapto-1-propanol, and four reaction products of isothiocyanates with sulfanilamide were synthesized. Their antimicrobial activity against pathogenic plant microorganisms was investigated.     

Inhibitory effect of 9-(2-phosphonylmethoxyethyl)adenine on visna virus infection in lambs: a model for in vivo testing of candidate anti-human immunodeficiency virus drugs

The acyclic nucleoside phosphonate analog 9-(2-phosphonylmethoxyethyl)adenine (PMEA) was recently found to be effective as an inhibitor of visna virus replication and cytopathic effect in sheep choroid plexus cultures. To study whether PMEA also affects visna virus infection in sheep, two groups of four lambs each were inoculated intracerebrally with 10(6.3) TCID50 of visna virus strain KV1772 and treated subcutaneously three times a week with PMEA at 10 and 25 mg/kg, respectively. The treatment was begun on the day of virus inoculation and continued for 6 weeks. A group of four lambs were infected in the same way but were not treated. The lambs were bled weekly or biweekly and the leukocytes were tested for virus. At 7 weeks after infection, the animals were sacrificed, and cerebrospinal fluid (CSF) and samples of tissue from various areas of the brain and from lungs, spleen, and lymph nodes were collected for isolation of virus and for histopathologic examination. The PMEA treatment had a striking effect on visna virus infection, which was similar for both doses of the drug. Thus, the frequency of virus isolations was much lower in PMEA-treated than in untreated lambs. The difference was particularly pronounced in the blood, CSF, and brain tissue. Furthermore, CSF cell counts were much lower and inflammatory lesions in the brain were much less severe in the treated lambs than in the untreated controls. The results indicate that PMEA inhibits the propagation and spread of visna virus in infected lambs and prevents brain lesions, at least during early infection. The drug caused no noticeable side effects during the 6 weeks of treatment.     

In vitro platelet-activating factor receptor binding inhibitory activity of pinusolide derivatives: a structure-activity study

Pinusolide, a labdane-type diterpene lactone isolated from Biota orientalis, was found to be a potent platelet-activating factor (PAF) receptor binding antagonist. To investigate the structure-activity relationship and find derivatives with improved pharmacological profiles, 17 pinusolide derivatives were prepared and tested for their ability to inhibit the PAF receptor binding. The results demonstrated that the carboxymethyl ester group at C-19, the integrity of the alpha,beta-unsaturated butenolide ring, and the exocyclic olefinic function of pinusolide are all necessary for its maximum PAF receptor binding inhibitory activity. Among the derivatives, the 17-nor-8-oxo derivative 8 was found to be as potent as pinusolide. The results also suggested that several derivatives warrant further pharmaceutical and pharmacological studies due to their improved water solubility (8 and 11) and apparent lack of susceptibility to Michael-type nucleophilic addition (13 and 18).     

Scavenging activity of furan derivatives against hydroxyl radical generated by Fenton system

As the continuation of the work on the antioxidant properties of furan derivatives, we have studied hydroxyl radical (OH.) scavenging activity of dimethylfuran (DMF) and diphenylfuran (DPF), which are well-known as an effective scavenger of singlet oxygen, by an ESR spin trapping technique. The incubation mixture of 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as a spin trapping agent with FE2+ and H202 in 50% acetonitrile aqueous solution gave 1:2:2:1 line signals characteristic of DMPO-OH spin adduct. The additions of furan derivatives to the incubation mixture decreased the intensity of the DMPO-OH spin adduct signal in a dose-dependent manner. The activities of furan derivatives were in the order of DMF > DPF > furan. The decrease in the intensity of the signals was not due to the inhibition of OH. generating system itself and the destruction of the spin adduct by furan derivatives. By comparison with the common OH. scavengers, DMF and DPF were found to scavenge OH. more effectively than dimethylsulfoxide and mannitol. These results indicate that DMF and DPF can act as a OH. scavenger as well as a singlet oxygen scavenger.     

Vaccination of pregnant macaques protects newborns against mucosal simian immunodeficiency virus infection

Simian immunodeficiency virus (SIV) infection of newborn rhesus macaques is a rapid, sensitive animal model of human pediatric AIDS. Newborn macaques were readily infected by uncloned SIVmac following oral-conjunctival exposure and had persistently high viremia and rapid development of AIDS. In contrast, when 3 pregnant macaques were vaccinated against SIV, 2 of the newborns that had transplacentally acquired antiviral antibodies were protected against mucosal SIV infection at birth. These results suggest that intervention strategies such as active immunization of human immunodeficiency virus (HIV)-infected pregnant women and anti-HIV immunoglobulin administration may decrease the rate of perinatal HIV infection.     

Mechanism of protective immunity against influenza virus infection in mice without antibodies

We describe a hypothalamus-specific mRNA that encodes preprohypocretin, the putative precursor of a pair of peptides that share substantial amino acid identities with the gut hormone secretin. The hypocretin (Hcrt) protein products are restricted to neuronal cell bodies of the dorsal and lateral hypothalamic areas. The fibers of these neurons are widespread throughout the posterior hypothalamus and project to multiple targets in other areas, including brainstem and thalamus. Hcrt immunoreactivity is associated with large granular vesicles at synapses. One of the Hcrt peptides was excitatory when applied to cultured, synaptically coupled hypothalamic neurons, but not hippocampal neurons. These observations suggest that the hypocretins function within the CNS as neurotransmitters.     

Substrate specificity for isomerase activity of macrophage migration inhibitory factor and its inhibition by indole derivatives

Macrophage migration inhibitory factor (MIF) was discovered as a cytokine that inhibits random migration of macrophages and concentrates them at inflammatory loci. We recently reported the tertiary structure of MIF, and revealed its similarity to that of 5-carboxymethyl-2-hydroxymuconate isomerase. Moreover, MIF was found to have isomerase activity converting D-dopachrome, a stereoisomer of naturally-occurring L-dopachrome, to 5,6-dihydroxyindole-2-carboxylic acid. In this study, we examined the effects of a series of compounds analogous to D-dopachrome on the enzyme activity to obtain vital information for identification of a natural substrate of MIF. Adrenochrome, lacking a carboxyl group at position 2 of the indolinequinone ring, could not be a substrate. Several indole-ring-containing compounds with a carboxyl group were inhibitory to D-dopachrome isomerase activity, of which indole-3-acrylic acid was the most potent inhibitor, with an inhibitor constant (Ki) of 2.8 mM. 2,3-Indolinedione, which lacks a complete indole ring or a carboxyl group but has carbonyl groups at positions 2 and 3, apparently inhibited the enzyme activity in a competitive or mixed manner with a Ki of 0.9 mM. Taken together, these facts suggest that the 2-carboxyl group of the substrate is essential for interaction with the active site of MIF.     

In vitro activity of artemisinin derivatives against African isolates and clones of Plasmodium falciparum

To evaluate the effect of intensive physical exercise on intraocular pressure (IOP) in 66- to 85-year-old subjects IOP was measured before and after a maximal bicycle ergometer test. The non-glaucomatous subjects comprised 85 males and 36 female athletes and 16 male and 22 female controls of corresponding age drawn from a population register. IOP was measured using a non-contact tonometer. The results indicated a decrease (> or = 2 mmHg) in 34% of the subjects, no change in 57% and an increase in 9%. The decrease was more pronounced in subjects with higher pre-test values. In all four subjects with a pre-test value above 22 mmHg a reduction from 4 to 11 mmHg was observed. The change in IOP during physical loading was not significantly associated with the intensity and duration of exercise test. Three of the 5 male subjects with diagnosed glaucoma and undergoing hypotensive medication, who were analyzed separately, also showed a reduction in IOP during loading. In the pre- or post-test values there were no differences between the athletes and controls, while women tended to have higher IOP values than men. It is concluded that physical loading has predominantly a moderating effect, if any, on IOP in elderly men and women.     

Stereospecificity of 6'-C-neplanocin A analogues as inhibitors of S-adenosylhomocysteine hydrolase activity and human immunodeficiency virus replication

The R- and S-isomers of 6'-C-neplanocin A analogues, which are all known as inhibitors of S-adenosylhomocysteine (AdoHcy) hydrolase, were studied for their inhibitory effects on Human Immunodeficiency Virus type 1 (HIV-1) replication and HIV-1 Tat-mediated transactivation. The R-isomers showed much greater activity against AdoHcy hydrolase than the S-isomers. The same differential activity was observed against the HIV-1 replication and the Tat transactivation.     

Synthesis and antihypertensive activity of 4-(diazabicyclo[4.1.0]-heptenyloxy)benzopyran derivatives and their analogues

A series of 3,4-dihydro-3-hydroxy-4-[(5-oxo-3,4-diazabicyclo[4.1.0]hept- 2-en-2-yl)oxy]-2H-1-benzopyrans and their analogues were synthesized and evaluated on potassium channel opening and hypotensive activities. Compound (-)-13B with a (4-methyl-5-oxo-3,4-diazabicyclo[4.1.0]hept-2-en-2-yl)oxy group for the 4-position of the benzopyran ring was 3 times as potent as EMD 57283 (II), the lead compound, in hypotensive activity. The results would demonstrate that 5-oxo-3,4-diazabicyclo[4.1.0]hept-2-en-2-yloxy moieties are effective as the substituents at the 4-position of benzopyran-type potassium channel openers.     

Effects of frequent intranasal administration of adjuvant-combined influenza vaccine on the protection against virus infection

In previous papers, we have shown that Escherichia coli heat-labile enterotoxin B subunit, supplemented with a trace amount of the holotoxin (LTB*) could be used as a potent adjuvant for a nasal influenza HA (haemagglutinin) vaccine in humans. The present study was designed to determine whether the effectiveness of a combined LTB*-HA vaccine could be limited by preexisting immunity to LTB and how many times the adjuvant-combined vaccine could be administered intranasally without reducing its protective efficacy in BALB/c, C3H and B10 mice. The magnitude of both nasal and serum Ab responses to HA vaccine was correlated with the degree of protection against virus infection. Higher doses of LTB*-combined vaccine were required for inducing high enough levels of anti-HA Ab responses to provide complete protection in low responder mice. Repeated pretreatments with LTB* alone (more than six times), which provided high levels of preexisting Abs to LTB, inhibited the induction of anti-HA Ab responses and reduced the protective efficacy of the adjuvant-combined vaccine. However, the LTB*-combined vaccine could be given repeatedly (about ten times) to mice without reducing the effectiveness of the adjuvant-combined vaccine. These results suggest that the LTB*-combined nasal influenza vaccine can be given to humans once every few years when an epidemic of influenza may occur.