Infected Untreated Control Research Articles

THE BIOSYNTHESIS OF DEOXYGUANOSINE TRIPHOSPHATE (dGTP) IN HERPES SIMPLEX TYPE-1 (HSV-1) INFECTED VERO CELL TREATED WITH ACYCLOVIR (ACV) AND HYDROXYUREA (HU): 109

Purine deoxynucleoside triphosphate pools increased dramatically in HSV-1 infected vero cells treated with ACV. This study quantitatively compares the contributions of the ribonucleotide reductase (RR) and deoxyguanosine salvage pathways for the biosynthesis of dGTP in HSV-1 infected cells. [14C]Guanine introduced 1 hr after infection was readily incorporated into dGTP and HSV DNA. By 6-8 hrs after treatment with ACV at 100 μM, both dATP and dGTP pools increased 7 fold and [14C]dGTP accumulated 32 fold over untreated infected controls. The increase in [14C]dGTP, dGTP and dATP in the presence of ACV was prevented by HU at 10 mM, which inhibits RR. By prelabeling cellular DNA with [5'-3H]deoxyguanosine prior to infection, it was possible to show that salvage of deoxyguanosine, derived from host DNA, was a minor pathway for dGTP syntheis during infection, and that HU had no effect on this process. Greater than 99% of the dGTP in infected ACV treated cells was derived from the guanine ribonucleotide pool through the RR reaction, as compared with <1% of the dGTP being derived from the salvage of endogenous deoxyguanosine formed from [5'-3H]-labeled cellular DNA.

Immunosuppression in bovine trypanosomiasis: response of cattle infected with Trypanosoma congolense to foot-and-mouth disease vaccination and subsequent live virus challenge

The primary and secondary antibody responses to foot-and-mouth disease virus vaccine were examined in cattle infected with Trypanosoma congolense and the response of some of these animals to live foot-and-mouth disease virus challenge was assessed. Infected groups of cattle had rather lower antibody responses than uninfected control cattle after primary vaccination but the antibody titres were not significantly depressed until after secondary vaccination. These levels remained depressed for the duration of the experiment, ie, 183 days. Trypanocidal therapy with diminazene aceturate of infected cattle at the time of vaccination did not significantly improve the antibody response to primary vaccination. Their subsequent response to live virus challenge was somewhat equivocal in that the number of animals protected was not significantly different in comparison to the untreated infected and uninfected controls. It was concluded that trypanosome-infected cattle do not produce optimal responses to foot-and-mouth disease vaccination. Nevertheless, the antibody titres are generally above those considered adequate to confer 95 per cent protection against needle challenge.

In Vitro and In Vivo Activity of a Synthetic Halogenated Quinoline Against Cryptococcus neoformans

The minimum inhibitory concentrations of a halogenated quinoline, 3-amino-7-chloro-3,4-dihydro-1-hydroxycarbostyril (CBS), against nine clinical strains of Cryptococcus neoformans were determined by in vitro testing. The CBS was fungistatic at a minimum concentration of 0.2 mug/ml at 48 h for several strains. In vivo toxicity studies were carried out in mice. Mice were also infected with C. neoformans strain Price and injected with various concentrations of CBS. Mean life expectancy of treated groups of animals was increased over infected untreated controls.

Response to primary infection with Herpesvirus saimiri in immunosuppressed juvenile and newborn squirrel monkeys

Immunosuppression of juvenile squirrel monkeys with combined azathioprine, prednisolone, and antilymphocyte globulin resulted in decreased antibody responses to viral antigens after primary infection with Herpesvirus saimiri (HVS). The virus was repeatedly isolated from the oropharynx of immunosuppressed monkeys but not from untreated infected controls. Thus immune factors are important in inhibiting shedding of HVS from the oropharynx. HVS could be isolated from the peripheral blood lymphocytes of infected control monkeys but not from the lymphocytes of immunosuppressed monkeys. Immunosuppressed monkeys also had decreased percentages of lymphocytes capable of forming rosettes with sheep erythrocytes. These results indicate that the immunosuppressive agents had inhibitory effects on lymphocytes (presumably thymus derived) capable of being latently infected with HVS. Antibody responses in newborn monkeys infected with HVS were delayed compared with juvenile monkeys. Treatment of newborn monkeys with antilymphocyte globulin had no suppressive effect on antibody responses to HVS.

Deoxyribonucleic acid replication in simian virus 40-infected cells. IV. Two different requirements for protein synthesis during simian virus 40 deoxyribonucleic acid replication.

The replication of simian virus 40 (SV40) deoxyribonucleic acid (DNA) was inhibited by 99% 2 hr after the addition of cycloheximide to SV40-infected primary African green monkey kidney cells. The levels of 25S (replicating) and 21S (mature) SV40 DNA synthesized after cycloheximide treatment were always lower than those observed in an infected untreated control culture. This is consistent with a requirement for a protein(s) or for protein synthesis at the initiation step in SV40 DNA replication. The relative proportion of 25S DNA as compared with 21S viral DNA increased with increasing time after cycloheximide treatment. Removal of cycloheximide from inhibited cultures allowed the recovery of viral DNA synthesis to normal levels within 3 hr. During the recovery period, the ratio of 25S DNA to 21S DNA was 10 times higher than that observed after a 30-min pulse with (3)H-thymidine with an infected untreated control culture. The accumulation of 25S replicating SV40 DNA during cycloheximide inhibition or shortly after its removal is interpreted to mean that a protein(s) or protein synthesis is required to convert the 25S replicating DNA to 21S mature viral DNA. Further evidence of a requirement for protein synthesis in the 25S to 21S conversion was obtained by comparing the rate of this conversion in growing and resting cells. The conversion of 25S DNA to 21S DNA took place at a faster rate in infected growing cells than in infected confluent monolayer cultures. A temperature-sensitive SV40 coat protein mutation (large-plaque SV40) had no effect on the replication of SV40 DNA at the nonpermissive temperature.

Sulfonamide Resistance in Chicken Coccidiosis: A Clinico-Pathological Study

Coccidiosis is a disease of great economic importance for the emerging poultry industry of Bangladesh. Sulfonamides have been used extensively for treatment and control of chicken coccidiosis. However, there have been complaints regarding failure of Esb3 ® (sodium sulfachloropyrazine monohydrate; Ciba-Geigy) in treating clinical coccidiosis. Therefore this study was undertaken to examine the degree of sulfonamide resistance of field coccidian isolates. Four groups of 12-day-old chicks were infected with 104 sporulated oocysts of four field coccidian isolates. Each group contains four subgroups containing 8 chicks in each subgroup, among which one subgroup remained as infected untreated control and another 3 subgroups were treated with 30% Esb3 ® @ 1 , 2, or 2.5 g/l of drinking water for 3 consecutive days. The sulfonamide resistance was assessed on the basis of faecal oocyst counts and clinico-pathological findings. There was no significant difference (p &gt;0.05) in weight gain between untreated chicks and the chicks treated @ 1 and 2 g/l. However, a significantly higher (p &lt;0.05) weight gains were noted in subgroups treated with Esb3 ® @ 2.5 g/l. Chicks received treated with 2 g/l Esb3 ® received similar clinical coccidiosis and histopathological changes but little less oocyst counts as found in untreated infected control chicks. Chicks treated with 2 g/l Esb3 ® did not reveal clinical coccidiosis and revealed no or very minimal oocyst counts during the treatment period. But on histopathology, arrested or stunted parasitic stages were found during the treatment period whereas flourish parasitic development with subacute-chronic ulcerative caecitis was evident following withdrawal of treatment. These findings suggest that the drug only cause an arrested parasitic development rather than killing the parasite. Therefore, an alternative to the sulfonamides needs to find out for treating and controlling chicken coccidiosis. Keywords: Chicken; Coccidiosis; Sulfonamide; ResistanceDOI: http://dx.doi.org/10.3329/bjm.v25i1.4860 Bangladesh J Microbiol, Volume 25, Number 1, June 2008, pp 60-64

Gongronema latifolium Benth. Leaves (Uteze) Ameliorate Malaria Infection in Plasmodium berghei-Infected Mice

Herbs are vital sources of bioactive compounds. This study evaluates the antimalarial, antioxidant, phytochemical and nutritional properties of Gongronema latifolium Benth. (Uteze) leaves. Pulverized dry leaves sample were macerated in hexane, methanol, ethanol and distilled water to obtain their respective extracts. The antimalarial efficacy of these extracts was assessed in male Swiss albino mice infected intraperitoneally with chloroquine-sensitive Plasmodium berghei NK65, using the chemo-suppressive, prophylactic and mean survival time (MST) assays. Phytochemical and proximate analyses were assessed by standard protocols. The antioxidant capacity of the extracts was analyzed using DPPH radical scavenging and ferrous ion chelating assays. From the results, the plant had significant (p &lt; 0.05) antimalarial activity compared to the infected untreated control. The chemo-suppressive activity of the extracts declined accordingly; ethanol (46.34%) &gt; methanol (43.16%) &gt; aqueous (32.24%), while their prophylactic activity declined in the order of aqueous (40.25%) &gt; ethanol (38.99%) &gt; methanol (26.94%). Only MST in the four-day chemo-suppressive assay was significant (p &lt; 0.05) compared to the infected untreated control. Tannins, alkaloids, flavonoids, saponins, phenolics, cardiac glycosides and proanthocyanidins were detected in reasonable quantities in the plant. The plant also had antioxidant activity as the aqueous extract (IC50 48.50 ± 0.42) scavenged DPPH radicals better, while methanol extract (IC50 21.15 ± 0.33) chelated ferrous ion radicals more compared to other extracts. Meanwhile, the percentage nutritional composition of the plant was moisture (6.23 ± 0.01), total ash (2.22 ± 0.02), crude fat (16.32 ± 0.04), crude fibre (1.04 ± 0.01), crude protein (9.33 ± 0.58) and nitrogen free extract (64.85 ± 0.63). In conclusion, the antimalarial activity of Gongronema latifolium Benth. (Uteze) leaves could be due to its rich phytochemical and nutritional properties.

The effect of sublethal doses of the molluscicide (N-tritylmorpholine) on the development of Schistosoma mansoni in Biomphalaria glabrata (Say).

1. The effects of a sublethal concentration (0·0165 p.p.m.) of N-tritylmorpholine on the development of S. mansoni in B. glabrata are described.2. A total of 160 snails were infected with S. mansoni and then divided into 4 groups. Each group was treated separately with N-tritylmorpholine for a period of 24 hours.3. The first group was treated 10 days after infection (early prepatent stage); the second group 20 days after infection (late prepatent stage); the third group 42 days after infection (patent stage); and the fourth group was left untreated and kept as an infected but untreated control group.4. Three groups of uninfected snails were treated simultaneously with the infected groups, and a fourth uninfected group was left untreated and maintained as an uninfected and untreated control group.5. In the early and late prepatent groups treated with N-tritylmorpholine a relatively short incubation period was observed compared with those in the patent and untreated infected groups.6. No significant difference was observed between the cercarial infection rates of the 4 infected groups of snails (x2 = 0·744; p &gt; 0·5).7. In all infected groups peak cercarial production was observed about 15–20 days after the emergence of cercariae was first noted, after which numbers declined. No significant difference was observed between the total cercarial production of the early prepatent, late prepatent or patent groups and that of the untreated infected control group (p &gt; 0·4).8. The mortality rate of snails in the patent group was significantly higher than in the corresponding uninfected control group (x2 = 6·04; p &lt;0·02).9. Treated infected snails in all three groups ultimately had a lower survival rate than did treated uninfected snails.10. The survival rate of untreated infected snails while initially as good as that of the untreated and uninfected group, was ultimately much poorer.

The Inhibitory Effect of a Dithiosemicarbazone on Acute Infections of Anaplasma marginale

Acute infections of Anaplasma marginale in splenectomized calves and adult cattle were inhibited by administering a micronized suspension of α-ethoxy-ethylglyoxal dithiosemicarbazone. Intravenous administration produced the best results. A comparison of treated principals with untreated infected controls showed that a single dose of 5 mg./kg. body-weight suppressed parasite development, lessened anaemia and increased the survival rate. Acute anaplasmosis did not develop in a yearling steer given a subcutaneous dose of 10 mg./kg. suspended in Freund’s incomplete adjuvant

Production in mice of tolerance to the toxic manifestations of Candida albicans.

Hasenclever, H. F. (National Institutes of Health, Bethesda, Md.) and William O. Mitchell. Production in mice of tolerance to the toxic manifestations of Candida albicans. J. Bacteriol. 84:402-409. 1962. - Lethal toxic manifestations of Candida albicans in mice were demonstrated by the intravenous injection of 10(7) viable yeast cells. Untreated control animals had an average survival time of 4.5 to 10 hr after challenge. No multiplication of C. albicans could be demonstrated in the tissues of untreated infected controls 12 hr after challenge. Mice infected ip with C. albicans 6 days before iv challenge survived for periods three to four times longer than controls. Mice previously infected with other fungi also demonstrated tolerance to the toxicity of C. albicans. Coccidioides immitis and C. stellatoidea were especially effective. High-titer rabbit antiserum to viable C. albicans yeast cells was not protective. Studies of total and differential peripheral leukocytes indicated that mice in the tolerant state demonstrated a slight granulocytosis. Direct evidence of the protective effect of the granulocytic response was not shown

Effect of diethylcarbamazine, oxophenarsine hydrochloride and piperazine citrate on Toxocara canis larvae in mice

Diethylcarbamazine (Hetrazan) and oxophenarsine hydrochloride (Mapharsen) but not piperazine citrate (Antepar) exhibited a limited degree of effectiveness against the larvae of Toxocara canis in white mice. Diethylcarbamazine used for a protracted period in an established T. canis infection in mice reduced the number of larvae to 35% of those recoverable from infected untreated control mice. However this drug proved ineffective against the larvae during hatching and early migration periods. Oxophenarsine hydrochloride in 1-mg doses either once or twice a week was somewhat effective when given for 6 weeks in an established T. canis infection in mice, reducing the larvae to 77% of the number recoverable from infected untreated controls. Blood eosinophilia was observed to occur during the known periods of larval migration of this ascarid in mice, although the magnitude was variable and apparently was unaffected by the administration of either diethylcarbamazine or oxophenarsine hydrochloride.

Sulfamethazine Treatment of Cecal Coccidiosis

Until last year no drug was available for the treatment of coccidiosis in chickens. Horton-Smith and Taylor (1942) demonstrated that 2 percent sulfamethazine1 in the mash prevented the development of symptoms in birds infected with Eimeria tenella when administered 96 hours after infection. Horton-Smith and Taylor (1943) also showed that a saturated solution of sulfamethazine substituted for the drinking water was efficacious in the treatment of cecal coccidiosis, treatment being instituted after the symptoms appeared.EXPERIMENTALFour-week-old White Leghorn chicks, supplied by the poultry husbandry department of this station, were divided into three groups of 25 each. These served respectively as (1) uninfected controls, (2) infected untreated controls, and (3) infected sulfamethazine treated birds. The latter two groups of birds were infected by placing equal amounts of a suspension of sporulated oöcysts of E. tenella in the mash. The birds were weighed one week before infection and thereafter at weekly .