Biomedical subjects

M E Rose

Publications and source records attributed to M E Rose.

At least 37 records · Page 2Linked to original sources

PubMed1994

Eimeria maxima: ELISA and western blot analyses of protective sera.

Infection of chickens with Eimeria maxima induces the production of parasite-specific antisera which can be used passively to protect naive chickens against infection. Globulin fractions of these antisera can also be used passively to protect chickens. Similarly, intramuscular injection of soybean lectin affinity purified gametocyte antigens of E. maxima in Freund's Complete Adjuvant induces production of antibodies which are maternally transferred and thereby protect hatchlings against E. maxima. ELISA analyses of serum pools having varying protective capacities revealed good correlations between passive protection and levels of anti-unsporulated oocyst, anti-sporulated oocyst, anti-merozoite and anti-gametocyte antibodies. Western blotting demonstrated that the sera mainly recognized a number of high molecular weight antigens in all developmental stages and that the intensity of the reactions reflected the degree of protection induced by the sera. Sera from birds immunized with gametocyte antigens also recognized high molecular weight antigens from all the developmental stages, with banding patterns remarkably similar to those observed for sera from infected birds. Taken together, these results indicate that antibodies can protect against infection with E. maxima and these antibodies may recognize and act against asexual and/or sexual stages of the parasite.

Animals↗

PubMed1994

Immunization against experimental coccidiosis produces contrasting results in inbred mice of differing susceptibility to infection.

Pretreatment of inbred mice with intravenous and/or intraperitoneal injection of an antigen prepared from sporozoites of Eimeria vermiformis modulated the course of infection with the parasite in a manner that depended on the resistance-susceptibility phenotype of the host. Mice with a resistant background (BALB) produced more oocysts and those with a susceptible background (C57BL) produced fewer oocysts than their respective controls. The optimum conditions for producing these effects were established, and evidence is presented which suggests that the phenomenon might also apply in the target host, the chicken.

Animals↗

PubMed1993

Immunity to coccidiosis: genetic influences on lymphocyte and cytokine responses to infection with Eimeria vermiformis in inbred mice.

Cellular and cytokine responses to infection with Eimeria vermiformis were compared in BALB/c (resistant) and C57BL/6 (B6-susceptible) inbred mice. Cellular responses in the mesenteric lymph node (MLN) occurred sooner after primary infection in the resistant BALB/c strain. In contrast, proliferative responses occurred earlier after challenge in B6 mice. Resting levels of CD4 + ve and CD8 + ve T-lymphocytes in the MLN differed between the two strains but the relative numbers of each subset remained relatively constant throughout primary infection. MLN cells taken at intervals after infection were assayed for release of the cytokines IFN-gamma, IL-5 and IL-10 after culture in vitro with the mitogen Concanavalin A (Con-A) or with parasite antigen. With either stimulus cells from resistant BALB/c mice released IFN-gamma and IL-5 earlier after infection than did B6 cells. The strains had a comparable absolute ability to produce IFN-gamma but BALB/c cells released more IL-5 than did B6, levels declining, rather than increasing, during primary infection in the latter. Only cells from BALB/c mice released IL-10 during infection. Cells taken after a secondary infection released relatively little cytokine after pulsing in vitro. These data suggest that the difference in response phenotype between the two strains when infected with E. vermiformis reflect a kinetic, rather than a qualitative, difference in ability to mount protective T-helper (Th) cell subset responses. No evidence was found for a Th2-mediated interference with ability to release IFN-gamma, the cytokine most closely associated with protective immunity.

Animals↗

PubMed1992

Isolation of acylcarnitines from urine: a comparison of methods and application to long-chain acyl-CoA dehydrogenase deficiency.

Carnitine esters from acetylcarnitine (C2 acyl chain) to octadecanoylcarnitine (C18 acyl chain) can be extracted from urine with recoveries of greater than 80%. However, to obtain such recoveries, it is important to choose the method of extraction appropriate to the acylcarnitines of interest. For acylcarnitines with acyl chain length C2 to C8 (acetylcarnitine to octanoylcarnitine), an ion-exchange procedure is recommended. Acylcarnitines with acyl chain length C8 to C12 (octanoylcarnitine to dodecanoylcarnitine) are best isolated from carefully acidified urine by solvent extraction with butan-1-ol. For long-chain acylcarnitines, C10 to C18 (decanoylcarnitine to octadecanoylcarnitine), solvent extraction of unacidified urine with hexan-2-ol is particularly simple and effective.

Acyl-CoA Dehydrogenase, Long-Chain↗

PubMed1992

Identification of urinary acylcarnitines using gas chromatography-mass spectrometry: preliminary clinical applications.

Many disorders of organic acid metabolism are associated with abnormalities in the levels of acylcarnitines excreted in urine. Profiling of urinary acylcarnitines allows diagnosis and characterisation of many acidurias and acidemias, monitoring dietary treatment of such patients, and elucidation of the metabolism of some exogenous acidic compounds. Urine (ca. 0.5 ml) was subjected to a simple work-up by ion-exchange chromatography, and the isolated acylcarnitines were derivatized by cyclization in 35 min to give volatile lactones that are compatible with gas chromatography-mass spectrometry using electron or chemical ionization. The feasibility of this new and affordable procedure has been confirmed by identifying urinary acylcarnitines in cases of medium-chain acyl-coenzyme A dehydrogenase deficiency, propionic acidemia and isovaleric acidemia.

Acylation↗

PubMed1992

Immune control of murine coccidiosis: CD4+ and CD8+ T lymphocytes contribute differentially in resistance to primary and secondary infections.

The effect of treatment with monoclonal antibodies (Mabs) which deplete CD4+ or CD8+ T lymphocytes, on infections with Eimeria spp. was examined in NIH mice. Treatment with anti-CD4 Mab increased susceptibility to primary infections with E. vermiformis or E. pragensis and reduced the subsequent resistance of the mice to homologous challenge. Similar treatment of immune mice did not affect their resistance to re-infection but this was reduced in mice depleted of CD8+ T lymphocytes. In mice immunized with E. vermiformis the effect of CD8(+)-depletion was very slight, apparent only as the presence of small numbers of oocysts in the faeces of some mice; in mice immunized with E. pragensis there was a small, though significant, increase in oocyst production, compared with controls and anti-CD4-treated groups. These results confirm the importance of mechanisms involving the function of CD4+ T lymphocytes in the control of primary infections with Eimeria spp. and indicate that CD8+ cells play some part in the expression of resistance to reinfection. They also show that a major part of this resistance was not affected by either of the treatments given.

Animals↗

PubMed1992

Intestinal changes associated with expression of immunity to challenge with Eimeria vermiformis.

To provide more information on the mechanisms involved in the immune inhibition of eimeria infections, NIH mice were adoptively immunized against infection with Eimeria vermiformis by the transfer of mesenteric lymph node cells from primed animals and homologously challenged. Subsequent changes in the architecture and cellular composition of the intestine were compared with those observed in similarly challenged susceptible control mice and correlated with the development of the parasite in the two groups. Actively immunized mice were also examined. In adoptively immunized mice, the development of E. vermiformis was inhibited within 3 days of administering the challenge inoculum. Concurrent changes in the intestine included lymphocytic infiltration, crypt hyperplasia, flattening of the crypt epithelium, and a reduction in the number of Paneth cells. Hyperplasia of goblet and pyroninophilic cells in response to challenge, although accelerated and enhanced in adoptively immunized hosts, occurred after the inhibition of the parasites, and mastocytosis was not observed in these animals, findings which suggest that the activities of goblet, pyroninophilic, and mast cells were not instrumental in reducing the numbers of parasites. The intestines of immunized mice contained fewer intraepithelial lymphocytes at the time of inhibition of the parasites than did those of the controls. The protective effects and intestinal changes described above did not differ appreciably from those seen after challenge of mice that had been immunized by infection.

Animals↗

PubMed1992

Alfentanil-induced hypermetabolism, seizure, and histopathology in rat brain.

We evaluated the effect of alfentanil on hippocampal glucose utilization and histopathology associated with alfentanil-induced seizures. Three separate experiments were performed. First, anesthetized, paralyzed Long-Evans rats (n = 15; 5 rats per group) were mechanically ventilated and randomly assigned to three groups: (a) control, 70% N2O and 30% O2 continued for 1 h; (b) low-dose alfentanil (150 micrograms/kg i.v. bolus), followed by infusion at 15 micrograms.kg-1 x min-1 for 1 h without N2O; or (c) high-dose alfentanil (1000 micrograms/kg i.v. bolus), followed by infusion at 100 micrograms.kg-1 x min-1 for 1 h without N2O. After 1 h, [6-14C]glucose was injected intravenously for autoradiography. With high-dose alfentanil, there was increased glucose utilization in the ventral hippocampus and the lateral septal nucleus. In the second experiment, anesthetized, paralyzed Sprague-Dawley rats (n = 12; 4 rats per group) were mechanically ventilated, underwent insertion of hippocampal depth electrodes, and were randomly assigned to three groups: (a) control, 70% N2O and 30% O2; (b) low-dose alfentanil (150 micrograms/kg i.v. bolus), with 70% N2O and 30% O2; or (c) high-dose alfentanil (1000 micrograms/kg i.v. bolus), with 70% N2O and 30% O2. An epileptiform pattern was observed on hippocampal and subdermal electroencephalographic recordings in both alfentanil groups. In the third experiment, anesthetized, paralyzed Sprague-Dawley rats (n = 20) were mechanically ventilated and assigned to two groups: (a) control, 70% N2O and 30% O2 (n = 5) or 100% O2 (n = 5) continued for 1 h; or (b) alfentanil (2000 micrograms/kg i.v. bolus), followed by infusion at 33.3 micrograms.kg-1 x min-1 for 1 h with 100% O2. After tracheal extubation, the rats recovered overnight. Light-microscopic evaluation revealed hippocampal or amygdaloid damage in 6 of the 10 alfentanil-treated rats. High doses of alfentanil administered to rats can produce limbic system seizure activity with hypermetabolism associated with neuropathologic lesions.

Alfentanil↗

PubMed1991

Eimeria tenella: localization of the sporozoites in the caecum of the domestic fowl.

When sporozoites of Eimeria tenella were inoculated into an isolated horn of the bicornuate caecum of the domestic fowl, replicating infections, culminating in the production of oocysts, were found, almost exclusively, in the inoculated horn. In contrast, sporozoites of E. tenella introduced into the bloodstream via a superficial vein induced infections of equivalent intensity in both horns of the caecum. These findings are discussed with reference to (1) the detection (by tissue transfer) of infective sporozoites in samples of cardiac blood and vascular tissues taken within 3 to 18 h of the oral inoculation of oocysts, and (2) the (previously published) observation that the sporozoites of E. tenella are transported from the superficial epithelium of the caecum (site of invasion) to the crypts (site of initial development) within host intra-epithelial lymphocytes. We suggest that a local inflammatory response to the invasion of sporozoites may be responsible for their re-location in proximity to the site of entry. This could act by directing the homing (or retention) of the parasite-bearing lymphocytes, and/or by providing a stimulus for the sporozoite to leave its transporting cell.

Animals↗

PubMed1991

Identification of a sterol mutant of Neurospora crassa deficient in delta 14,15-reductase activity.

A mutant (erg-3) of Neurospora crassa resistant to the polyene antibiotic nystatin was compared with its sensitive, wild-type parent to detect differences in sterol composition using gas chromatography-mass spectrometry. The major sterol in wild-type mycelia, comprising 80% of the total, was ergosterol. The major sterols in mutant mycelia, comprising 86% of the total, were delta 8,14-sterols. It is proposed that the nystatin-resistant strain is unable to synthesize ergosterol because it lacks delta 14,15-reductase activity as a result of a mutation in the erg-3 gene.

Ergosterol↗

PubMed1991

Interferon-gamma-mediated effects upon immunity to coccidial infections in the mouse.

The effect of treatment with a monoclonal antibody (MoAb) capable of neutralising interferon-gamma (IFN-gamma) on the course of coccidial infections in mice (C57BL/6 and NIH infected with Eimeria vermiformis or E. pragensis, and BALB/c infected with E. pragensis) was examined. The results differed with the species of parasite, the strain of mouse, the measure of infection and whether the infection was a primary or secondary one. The replication of E. vermiformis in primary infections was enhanced in both C57BL/6 and NIH mice, but less MoAb was required in NIH than in C57BL/6 to produce similar effects. In neither strain did treatment prevent priming or interfere with the complete immunity to challenge normally induced by moderate infection with E. vermiformis. The replication of E. pragensis in primary infections was not affected in any of the strains of mouse but the clinical effects were exacerbated. Priming with E. pragensis was unaffected by treatment but the partial immunity to challenge, normally induced by infection with this species, was reduced when MoAb was given 2 h before challenge. This reduction was evident as an increased faecal output of oocysts and loss of body weight. These results confirm the role of IFN-gamma in resistance to coccidiosis and further emphasise the complexity of the immune response in this disease.

Animals↗

PubMed1991

Gamma interferon-mediated inhibition of Eimeria vermiformis growth in cultured fibroblasts and epithelial cells.

The growth of Eimeria vermiformis within cultured murine fibroblastlike (L-929) or rat epithelial-like (RATEC) cells was inhibited by treatment of the cells with the appropriate recombinant gamma interferon. The effect was apparent as a reduction in both the initial numbers of intracellular sporozoites and, to a much greater extent, the numbers of subsequent developmental stages. Pretreatment of the host cells was more effective than treatment in the early postinvasive period, and recombinant gamma interferon had no effect on the development of the parasite if added 24 h or later after the inoculation of sporozoites. Incubation of sporozoites in medium containing recombinant gamma interferon in no way affected their ability to invade or to grow within host cells. These findings indicate that the inhibitory effects of recombinant gamma interferon on the growth of E. vermiformis are mediated via the host cell and are directed mainly against the transforming sporozoite, although the ability of the sporozoite to invade the host cell was also reduced to some extent. The later developmental stages were refractory to the effects of this lymphokine.

Animals↗

PubMed1990

Eimeria vermiformis: differences in the course of primary infection can be correlated with lymphocyte responsiveness in the BALB/c and C57BL/6 mouse, Mus musculus.

BALB/c and C57BL/6 mice are high- and low-responders, respectively, to infection with Eimeria vermiformis, this genetically determined difference being immunologically mediated. In order to identify the level at which response phenotype is determined, the proliferation of mesenteric lymph node cells and their ability to transfer immunity adoptively were investigated in each strain; the development of circulating serum antibodies to E. vermiformis was also determined. In all respects BALB/c mice responded earlier than the C57BL/6 but peak values were similar in both strains. The relationship between the temporal differences noted and the characteristic, differing course of the primary infection in the two strains is discussed.

Animals↗

PubMed1990

Simple and unambiguous method for identifying urinary acylcarnitines using gas chromatography--mass spectrometry.

Several inherited metabolic disorders, particularly the organic acidurias and acidemias, are often characterised by excretion of acylcarnitines, especially octanoylcarnitine, in the urine. Clinical investigation of such serious disorders ideally requires a rapid, simple and selective method for determining acylcarnitines in urine. Initial results are given here of a method that may approach this ideal. The procedure involves chemical derivatisation, in which the zwitterionic acylcarnitines are cyclised to volatile lactones, and analysis by gas chromatography and gas chromatography--mass spectrometry. Preparation of urine samples by ion-exchange purification and an illustrative application of the proposed method to a clinical sample are also outlined.

Acetylcarnitine↗

PubMed1989

Defective sterol C5-6 desaturation and azole resistance: a new hypothesis for the mode of action of azole antifungals.

Two azole resistant isolates of Saccharomyces cerevisiae carried mutations allelic to erg 3 and were blocked to differing degrees at the C5-6 desaturation step of ergosterol biosynthesis. When treated with the sterol 14 alpha-demethylation inhibitor fluconazole the wild-type sensitive strain accumulated lanosterol and 14 alpha-methyl-erogosta-8,24(28)-dien-3 beta, 6 alpha-diol (14-methyl-3,6 diol). The stringent desaturase mutant, A2, accumulated 14 alpha-methyl-8,24(28)-dien-3 beta-ol (14-methyl fecosterol) and lanosterol as the major sterol components when treated with fluconazole. Resistant isolate A3 accumulated 14-methyl-3,6-diol, 14-methyl fecosterol, and lanosterol and was only partially blocked at sterol C5-6 desaturation. We conclude that functional sterol C5-6 desaturase is required for the synthesis of 14-methyl-3,6-diol under conditions of azole inhibition. We present a new hypothesis for the mode of action of azole antifungals based on the inability of 14-methyl-3,6-diol to support growth, and suggest that growth can occur through utilisation of 14-methyl fecosterol, produced by a combination of azole inhibition and defective sterol C5-6 desaturation.

Antifungal Agents↗

PubMed1989

Eimeria vermiformis and E. mitis: inhibition of development in vivo by cyclosporin A.

Treatment of the host (Mus musculus, Gallus domesticus) with cyclosporin A during infection with Eimeria vermiformis or E. mitis resulted in a reduction in the numbers of oocysts passed in the feces and/or a delay in patency. The general immunosuppressive effects of the treatment were confirmed in chickens by monitoring their antibody responses to human erythrocytes and lymphoproliferative responses to phytohemagglutinin. Nevertheless, mice and chickens treated with cyclosporin A during a primary infection with E. vermiformis or E. mitis, respectively, were immune to subsequent challenge with these organisms. Thus, cyclosporin A did not interfere with priming. The antiparasite effect of the drug did not allow an evaluation of its effect on established immunity to the coccidia when it was administered at the time of challenge. In an exceptional treated chicken, however, delayed patency of the challenge infection was followed by the production of a number of oocysts similar to that found in unprimed animals. This suggests that the mechanisms of immunity to challenge may be susceptible to disruption by cyclosporin A.

Animals↗

PubMed1989

Immunity to coccidiosis: T-cell control of infection with Eimeria vermiformis in mice does not require co-operation with inflammatory cells.

The necessity for co-operation between lymphocytes and myeloid-derived inflammatory cells in the mediation of anti-coccidial immunity was investigated using mice infected with Eimeria vermiformis. Reciprocal exchange of immune lymphocytes between H-2 compatible strains of contrasting susceptibility to infection (resistant BALB/B and susceptible C57BL/10) resulted in successful transfer of immunity in both homologous and heterologous exchanges. Recipients of immune cells, whatever their original response phenotype, expressed a high degree of immunity to infection, indicating that the differential susceptibility of the strains is a property of their lymphoid cells and is not attributable to their capacity to mount inflammatory responses. This conclusion was confirmed by the successful adoptive transfer of immunity into NIH mice previously exposed to 600 rad X-irradiation; at this level of irradiation inflammatory responsiveness is severely depressed. Additional confirmation that strain-response phenotype is lymphocyte dependent and that immune lymphocytes can mediate their effects against E. vermiformis without the intervention of inflammatory cells was obtained from studies on the mucosal mast cell response to infection. No correlation existed between the development of intestinal mastocytosis, an index of T-cell-mediated inflammatory responsiveness, and the expression of resistance to E. vermiformis in BALB/c (resistant), C57BL/10 (susceptible) and NIH (susceptible) mice.

Animals↗

PubMed1989

Gamma interferon controls Eimeria vermiformis primary infection in BALB/c mice.

Neutralization of endogenous gamma interferon by treatment with a rat monoclonal antibody caused enhancement of infection with the protozoon Eimeria vermiformis in naive BALB/c mice. The effect was dose dependent and was apparent when a monoclonal antibody was given at 2 h before infection or up to 7 days postinfection, but it decreased with increasing time postinfection between days 4 and 7. The titers of parasite-specific antibodies in the serum were not significantly affected by the injection of monoclonal antibodies. Treatment during priming did not prevent the development of resistance to challenge, and treatment at the time of challenge did not abrogate established immunity. The results indicate that gamma interferon is involved in the control of primary infection with E. vermiformis in BALB/c mice but not in the expression of immunity to challenge.

Animals↗