Structural relationships in the OmpR family of winged-helix transcription factors

A survey of 108 individuals from a coastal Aboriginal community in north Western Australia revealed that two species of gastrointestinal protozoan parasites (Giardia duodenalis--39.8%, Entamoeba coli--40.7%) and five gastrointestinal helminths (Hymenolepis nana--54.6%, Hookworm [Ancylostoma duodenale]--30.6%, Enterobius vermicularis--6.5%, Trichuris trichiura--2.8%, Strongyloides stercoralis 1.9%) were present. A total of 29 individuals infected with hookworm were offered treatment with either pyrantel pamoate at a single dose rate of 10 mg/kg body weight or albendazole (single 400 mg dose). Seven days after treatment stool samples were examined. Pyrantel had no significant effect against hookworm. In contrast, albendazole cleared hookworm infections completely and reduced the prevalence of Giardia. The former result suggests that locally A. duodenale is resistant to pyrantel and despite its relatively low cost and wide availability, should not be considered a drug of choice at this dose rate in the treatment of hookworm infections (A. duodenale) in endemic regions.     

Endonasal dacryocystorhinostomy--primary and secondary

OBJECTIVE: To determine the prevalence of Giardia duodenalis and other intestinal parasites in children, dogs and cats from Aboriginal communities in the west Kimberley region of Western Australia. DESIGN: A four-year parasitological survey of faecal specimens from humans and faecal and intestinal specimens from dogs and cats. SETTING: Local hospital servicing Aboriginal communities surveyed in this study and the Veterinary School, Murdoch University. POPULATION: Children (under 14 years) and adults, as well as dogs and cats, from five Aboriginal communities. RESULTS: G. duodenalis was the most prevalent parasite in children and adults (32.1% in children, n = 361; 12.5% in adults, n = 24). Human infections with Hymenolepis nana (20.5%) and Entamoeba coli (13.0%) were also common. Ancylostoma duodenale (1.3%), Pentatrichomonas hominis (1.0%), Chilomastix mesnili (0.52%), Entamoeba hartmanni (0.52%), Sarcocystis sp. (0.52%), Trichuris trichiura (0.26%), Enterobius vermicularis (0.26%), Strongyloides stercoralis (0.26%) and Isospora belli (0.26%) were present at low rates. Dogs were most commonly infected with Ancylostoma caninum (51.1%) and G. duodenalis (17.0%). Cats were found to have a high prevalence of Ancylostoma tubaeforme (18.2%), Toxoplasma gondii (18.2%), Isospora felis (15.1%) and Spirometra erinacei (15.1%). CONCLUSIONS: This study has shown that children from Aboriginal communities in the west Kimberley region of Western Australia, particularly in the age group one to five years, are commonly infected with intestinal parasites. The dogs and cats in these communities are also infected. The high prevalence rates of Giardia and other enteric parasites in this survey are indicative of poor living conditions and low levels of hygiene. In addition, the high prevalence of hookworm and Giardia infection in dogs and hookworm and Toxoplasma infection in cats is of potential zoonotic significance for humans in these communities.     

Brain tissue pressure gradients created by expanding frontal epidural mass lesion

There are 2 major species of hookworms that infect humans. Ancylostoma duodenale and Necator americanus. Although traditionally considered to be identical for treatment purposes, there are significant life history differences between the species that must be considered for the rational design of chemotherapeutic and immunoprophylactic control strategies. However, identification of the species infecting a particular population has been problematic, as the eggs of the 2 species cannot be reliably differentiated by classical parasitological methods. A PCR-based technique for the differentiation of hookworm species that infect humans is reported. A fragment of the 3' untranslated region of the cAMP-dependent protein kinase catalytic subunit gene was amplified from A. duodenale and N. americanus genomic DNA using primers derived from the corresponding A. caninum cDNA. Digestion of the amplified DNA with the restriction enzymes HpaII, MboI, TaqI, and ThaI generated specific restriction fragment patterns unique to each species. The technique can distinguish between pure and mixtures of hookworm DNA and can amplify DNA from a single egg. The primers also amplify the fragment from the DNA of several other species of hookworms that infect humans and other animals. The technique is fast, simple, and hookworm specific and represents a considerable savings in time over current methods used for distinguishing between human hookworm infections.     

Electrocardiographic and respiratory responses to viscerotropic and neurotropic strains of Newcastle disease virus measured by radio telemetry

Two groups each of White Rock chickens from 6 to 23 weeks old were monitored by radio telemetry to determine their electrocardiogram and respiration response after they were infected with either a velogenic viscerotropic isolate of Newcastle disease virus (VVND) or the neurotropic GB strain of Newcastle disease virus (NGB). Significant changes were found in the heart rate, R wave amplitude, ST segment elevation, T wave amplitude, RS complex interval, ST segment duration T wave interval, TP segment duration, PR segment duration and TP interval of the birds infected with VVND, but no significant ECG changes were found in the birds infected with NGB. There were no significant changes in respiration rate in any birds.     

Effect of the strain of Toxoplasma gondii on the development of toxoplasmic encephalitis in mice treated with antibody to interferon-gamma

To examine whether differences observed in the development of toxoplasmic encephalitis between strains of Toxoplasma gondii are determined by the numbers of cysts occurring in the brain, C57BL/10 mice were infected with ten cysts of the ME49, Beverley, or C56 strain of the parasite. At 10 weeks after infection, the numbers of cysts and inflammatory changes in the brains of the mice were examined in each of the experimental groups. The ME49 strain formed significantly more cysts than did the other two strains, with no difference in the number of cysts being noted between the Beverley and C56 strains. Mice infected with the ME49 strain showed infiltration of inflammatory mononuclear cells in both the meninges and the parenchyma of their brains, whereas mice infected with the Beverley or C56 strain showed no inflammatory changes in their brains. Treatment of mice with a monoclonal antibody to interferon-gamma (IFN-gamma) once weekly for 3 weeks beginning at 10 weeks after infection augmented the inflammatory changes in the brains of mice infected with each strain. However, the intensity of the inflammatory changes differed significantly between the mice, depending on the strain of T. gondii with which they were infected. Mice infected with the ME49 strain showed the most remarkable inflammatory changes in their brains. Mice infected with the Beverley strain developed foci of acute inflammation in their brains after treatment with an antibody to IFN-gamma.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of some parasitic infection on neurotransmitters in the brain of experimentally infected mice before and after treatment

The effects of some parasitic infection (bilharziasis, toxocariasis and trichinosis) on the brain of experimentally infected mice were investigated. Eighty animals were classified into four groups, group I contained five non infected animals as a control group. The other groups each contained twenty-five mice infected with Schistosoma mansoni (group II), Toxocara canis (group III) and Trichinella spiralis (group IV). Each infected group was divided into two subgroups (a,b). Subgroup (a) left untreated and subgroups (b) treated by praziquantel (in group II) and mebendazole (in group III and IV). Histopathological and immunological examination using peroxidase antiperoxidase (PAP) technique and neurotransmitters estimation (nor-epinephrine, dopamine and serotonine) were carried. In the untreated animals, there were mild histopathological changes and mild antigenic deposition in subgroups (IIa and IIIa) and marked changes in subgroup (IVa). There were significant decrease in dopamine in subgroup (IIIa), not improved after treatment (subgroup IIIb) and significant decrease in nor-epinephrine and serotonine in subgroup (IVa) improved after treatment in subgroup (IVb). The neurotransmitters changes may explain the motor, behavioural and emotional changes that occurred with these parasites.     

The influence of energy intake on the pathophysiology of Trypanosoma congolense infection in Scottish blackface sheep

The intensity of parasitaemia, degree of anaemia, live body weight gains and blood biochemical changes were measured in two groups of Scottish Blackface sheep infected experimentally with Trypanosoma congolense and allowed either a high (9.9 MJ metabolisable energy (ME) day-1) or a low (6.1 MJ ME day-1) energy intake. It was observed that infected animals on the low energy intake had a longer mean prepatent period, but following patency they developed more severe anaemia and greater growth retardation than those on the high energy intake. Both infected groups exhibited significant reductions in serum total lipids, phospholipids, plasma cholesterol and albumin. However, these changes were more severe in the animals on the low energy intake than in those on the high energy intake. It was concluded that adequate energy nutrition enhances the ability of infected animals to withstand the adverse effects of infection, by promoting body weight gains and moderating the severity of the pathophysiological changes associated with ovine trypanosomosis.     

Morphological changes in the jejunum of calves naturally infected with Giardia spp. and Cryptosporidium spp

Giardiosis and cryptosporidiosis are frequently diagnosed in calves at the large animal clinic of the veterinary school. Few studies have been reported in the literature regarding pathogenesis of these two intestinal protozoa. The aims of this study were to follow the histological changes in the villi and crypts and the changes in the number of intraepithelial lymphocytes in the jejunum of naturally infected calves during the acute phase of infection. For this purpose, 29 calves aged between 7 and 10 days were bought at a local auction. The animals were housed in individual pens to avoid cross-contamination. Fecal samples were examined microscopically for the presence of Giardia cysts and Cryptosporidium oocysts, three times per week for a period of 45 days. Six calves did not pass any cysts or oocysts and were used as controls. Fifteen calves passed Giardia cysts only, five passed both cysts and oocysts, and three passed oocysts only. The villus to crypt ratio index was 1.76 in the control group and 1.08 in the Giardia-infected group. In the Cryptosporidium-infected calves, the ratio was 1.18 and calves infected with both parasites had an index of 1.37. The number of intraepithelial lymphocytes per millimeter of jejunum tissue was 21 in the control group. This number was doubled in the calves infected with Giardia, but was slightly lower in the other infected groups. All of the infected calves had intermittent diarrhea and mucus was seen in many fecal samples.     

Effect of substance P, insulin-like growth factor-1 and vasoactive intestinal polypeptide on corneal re-epithelialization in galactosemic rats

Glutathione peroxidase 1 (GPX-1) is a selenium-dependent enzyme with antioxidant properties. Previous investigations determined that mice deficient in selenium developed myocarditis when infected with a benign strain of coxsackievirus B3 (CVB3/0). To determine whether this effect was mediated by GPX-1, mice with a disrupted Gpx1 gene (Gpx1-/-) were infected with CVB3/0. Gpx1-/- mice developed myocarditis after CVB3/0 infection, whereas infected wild-type mice (Gpx1+/+) were resistant. Sequencing of viruses recovered from Gpx1(-/-)-infected mice demonstrated seven nucleotide changes in the viral genome, of which three occurred at the G residue, the most easily oxidized base. No changes were found in virus isolated from Gpx1+/+ mice. These results demonstrate that GPX-1 provides protection against viral-induced damage in vivo due to mutations in the viral genome of a benign virus.     

Changes in the generation cycle of duodenal crypt cells in chickens infected with Eimeria acervulina

Changes in the duration of the progenitor cycle and its four phases were determined for duodenal crypt cells in chickens infected with Eimeria acervulina. Metaphase curves were constructed using percent labelled metaphase nuclei in duodenal crypt cells at short intervals after the injection of [3H]thymidine. The duration of the progenitor cycle and its four phases were calculated using the synthetic index and data obtained from the metaphase curves. The cycle time was reduced from 14 h in control birds to 10.2 h at 2 days and 10.6 h at 4 days postinfection. The change was attributable entirely to a reduction in G1 or the presynthetic phase. In addition, the population of dividing cells within each duodenal crypt was almost doubled in infected birds. These increases in cell production precedes all the histological changes observed earlier in the intestines of E. acervulina infected chickens. At least in this instance, changes in crypt morphology seems, therefore, to result from an induced change in the functional activity of the crypt.     

Heart muscle cells acutely infected with Trypanosoma cruzi: characterization of electrophysiology and neurotransmitter responses

Primary cell cultures of mouse ventricular myocardium were infected with Trypanosoma cruzi, to study the consequences of T. cruzi-muscle cell interaction on the rate of spontaneous contractions, on the responses to norepinephrine, and on action potential parameters. Single cells or small cell groups of infected cultures were subjected to pharmacological and electrophysiological experiments. In concentrations ranging from 1 nM to 100 microM, norepinephrine exerted positive or negative chronotropic effects mediated by alpha-adrenergic receptors. A significant number of infected cells (25%) did not respond to the agonist. Two days after infection the cultures exhibited a higher frequency of spontaneous contractions (20%), paralleled by an increase in firing rate and a decrease in the action potential duration without significant changes in maximum diastolic potential and action potential amplitude. A decrease in alpha-adrenergic receptor-mediated positive chronotropic response to norepinephrine was also observed in 2-day infected cells. Cells made to phagocyte ferritin particles showed an increase in the rate of spontaneous contractions, but no changes in the positive chronotropic responses to norepinephrine. In conclusion, these observations show that during acute infection with T. cruzi, there are alterations in automaticity and in the chronotropic responses to norepinephrine, whose mechanisms are related to the process of parasite endocytosis by the cardiac cells.     

Effects of insulin-like growth factor-1 on luteinizing hormone secretion in sheep

Liver dysfunction often occurs during chemotherapy for AML, but the etiologies are many and varied. To determine liver dysfunction that is not related to HCV, liver function during intense therapy for one week after complete remission was studied in eight patients not infected with HCV (38 courses) and six HCV-infected patients (19 courses) with AML. There were remarkable differences in changes of ALT levels among HCV-infected patients. ALT level changes among patients not infected with HCV were similar. Changes in mean serum ALT levels in HCV-infected patients occurred at higher serum levels as compared with those in patients not infected with HCV. The mean serum ALT levels in patients not infected with HCV significantly increased at one week (45 +/- 5 IU/l) and further increased at two (58 +/- 8 IU/l) and three weeks (57 +/- 5 IU/l) as compared with pretreatment levels (24 +/- 21 IU/l) (p < 0.001, p < 0.001, p < 0.0001, respectively). ALT levels returned to normal at four weeks. During 31 of 38 courses (81.6%) in patients not infected with HCV, febrile episodes occurred at three weeks. The mean serum ALT levels in patients with febrile episodes were significantly higher than those in patients without febrile episodes at three weeks, and serum ALT levels at three weeks showed a significant positive correlation with CRP levels at three weeks. These findings indicate that liver dysfunction during chemotherapy for AML is due to hepatocellular injury, and infection or inflammatory cytokine induced by infection results in the worsening of the liver dysfunction.     

New systemic drugs in the treatment of gastrointestinal cancer

Our objective was to study the antibody response to the parotiditis, rubella, measles and tetanus vaccines in HIV infected children. Forty-four children of HIV positive mothers, of which 14 were infected (SG) and 33 HIV negative (CG) were studied when they were between 2 and 3 years of age. Their response to vaccinations of four doses of tetanus toxoid and one dose of measles, rubella and parotiditis vaccines was assessed. Children in the SG were tested at the age of 5-6 years to study the evolution of the response. At the age of 2-3 years, all children had optimal protection against tetanus toxoid. The response to measles, parotiditis and rubella was poor (adequate levels of antibodies in 50%, 25% and 21%, respectively) in infected children and good (93%, 75% and 90%, respectively) in the CG. At 5-6 years of age, a decreased level of antitetanus antibodies were found in the SG, maintaining low protection levels. There was no evidence of any changes in the response to measles, while the number of cases with a good response to parotiditis and rubella increased. Further results are necessary to know the effectiveness of the booster. We conclude that: 1) The immunological response to vaccination is poor in HIV infected children. 2) There was no evidence of side effects or changes in the HIV symptoms after vaccination.     

Therapeutic efficacy of hyperimmune bovine colostrum treatment against clinical and subclinical Cryptosporidium serpentis infections in captive snakes

Therapy based on the protective passive immunity of Hyperimmune Bovine Colostrum (HBC) (raised against Cryptosporidium parvum in dairy cows immunized during gestation) was tested for heterologous efficacy in subclinical and clinical infections of 12 captive snakes with C. serpentis. Six gastric HBC treatments of 1% snake weight at 1-week intervals each, have histologically cleared C. serpentis in three subclinically infected snakes, and regressed gastric histopathological changes in one of these snakes. In all snakes, each subsequent HBC treatment significantly decreased the number of oocysts recovered in gastric lavage eluants (P < 0.03). The treatments induced oocyst-negative gastric eluants and stools in all snakes, and improved clinical signs of infection. Clinically infected snakes displayed severe histopathological changes in the gastric region; however, the numbers of developmental stages of C. serpentis were moderate. Considering the severity of pathology, much lower than expected pathogen numbers were observed, and it is believed that clinically infected snakes did not have enough time to repair tissue damage that had occurred over the years of infection. As the HBC treatment was safe and highly efficacious, it is recommended to gastrically administer the HBC therapeutically to snakes that are clinically or subclinically infected with C. serpentis. Hyperimmune bovine colostrum can also be used in snake supportive therapy or prophylaxis.     

Dirofilaria immitis: experimental infection of rabbits with immature fifth-stage worms

To establish an animal model for human pulmonary dirofilariasis, we experimentally infected nine rabbits with immature fifth-stage worms of Dirofilaria immitis. The rabbits were infected by subcutaneous transplantation with various numbers of immature worms collected from 110- and 120-day-old infections of dogs. Four of seven rabbits infected with up to four larvae possessed encapsulated worms in the lungs at 196 or 308 days post-transplantation. Two rabbits transplanted with eight worms died of pulmonary hemorrhagic infarction 18 and 28 days post-transplantation. Marked histopathologic changes were observed in the lungs at the site of degenerating worms, which were encapsulated by a fibrous wall. Severe to mild infiltrations with eosinophils, heterophils, lymphocytes, plasma cells, and histiocytes were found in granulomas and their surrounding areas. The findings in these rabbits resemble those reported for human cases of pulmonary dirofilariasis.     

Polymorphonuclear neutrophils in saliva and blood: a comparative study of morphology, function and phenotype

Sixteen beagle dogs were injected intradermally with Rickettsia rickettsii. The dogs were divided into four groups (n = 4): 1) infected, non-treated control; 2) infected, treated with doxycycline; 3) infected, treated with doxycycline and an anti-inflammatory dose of corticosteroid; and 4) infected, treated with doxycycline and an immunosuppressive dose of corticosteroid. Thoracic radiographs were made and ocular fluorescein angiography was performed on days 6, 10, 17 post-inoculation. A mild interstitial lung opacity was noted in 4/16 dogs on day 6, 5/16 on day 10 and 3/16 on day 17 post-inoculation. Increased retinal vascular permeability was noted in 8/16 dogs on day 6, 3/16 on day 10 and 1/16 on day 17 post-inoculation. Correlation between the presence of radiographic and retinal lesions was not significant (p = 0.08). Eleven, naturally infected, dogs with thoracic radiographs and a final diagnosis of RMSF were also evaluated. Four of the 11 dogs had an unstructured interstitial pattern. Dogs with acute, experimentally-infected or naturally-occurring RMSF may have subtle pulmonary changes characterized by an unstructured interstitial pattern.     

Basal cell tetrasomy in low-grade cervical squamous intraepithelial lesions infected with high-risk human papillomaviruses

We have analyzed 60 low-grade cervical squamous intraepithelial lesions for low- and high-risk human papillomaviruses (HPVs) and for numerical abnormalities of chromosomes 1, 3, 11, 17, and 18 and the X chromosome. Eleven of 33 lesions infected with high-risk HPVs (HPV 16, 18, 30, 31, 33, 35, 39, 45, 51, 52, 56, 58, and 66) but none of 24 lesions infected with low-risk HPVs (HPV 6, 11, 42, 43, and 44) and none of 15 normal cervices showed basal cell tetrasomy of all six chromosomes in the HPV-infected areas. These changes were not HPV type specific and were not present in all lesions infected with the same HPV type. The presence of basal cell tetrasomy in lesions infected with high- but not low-risk HPVs suggests that induction of chromosome instability may be one mechanism underlying the biological differences between these viral types.     

Some studies on the growth and development of Echinococcus granulosus, camel origin in experimentally infected dogs

Development of Echinococcus granulosus of camel subspecies in 35 experimentally infected dogs was performed at 3, 7, 10, 13, 18, 23, 35 and 56 days post-infection (d.p.i.). Morphological characters of each developmental stage was studied and discussed. Generally, the results indicate that the segmentation firstly appeared at 18 d.p.i. Also, male and female genitalia could be detected at the same period. However, completely developed of genitalia appeared at 56 d.p.i. Histological examination of small intestine of experimentally infected dogs revealed that the parasites were found in distended and thin wall crypts of Liberkuhn at 3, 7, & 10 d.p.i, while the parasite scolices were found embedded in the mucosa at 13, 18 & 23 d.p.i. No significant pathological changes were encountered in both infected and control dogs. This is the first report of strobilar development of E. granulosus of camel origin in experimentally infected dogs.     

The normal association between newly replicated DNA and the nuclear matrix is abolished in cells infected by herpes simplex virus type 1

In cells infected by herpes simplex virus type 1 (HSV1), a series of nuclear changes can be observed in a temporal sequence. Such changes are related to important modifications in the higher-order structure of host cell chromatin, such as loss of DNA loop supercoiling and wholesale DNA loop disorganization. It is known that the topological relationship between DNA and the nuclear substructure is a critical factor for proper nuclear physiology. Here we report that the usual association between newly replicated DNA and the nuclear substructure, commonly known as nuclear matrix, is abrogated in cells infected by HSV1, thus establishing a correlation between the virus-induced modifications in chromatin higher-order structure and a major biochemical change within the infected cell nucleus.     

Modified plasma and abomasal disposition of albendazole in nematode-infected sheep

The influence of gastrointestinal nematode infection on the kinetics of albendazole (ABZ) and its metabolites, albendazole sulphoxide (ABZSO) and sulphone (ABZSO2) in plasma and abomasal fluid was investigated in sheep. A micronised suspension of ABZ was administered intraruminally at 7.5 mg kg-1 to the following groups of sheep: (a) non-parasitised (control); (b) artificially infected with Haemonchus contortus; (c) naturally infected with Haemonchus contortus and other species of gastrointestinal nematodes. Plasma and abomasal fluid samples were obtained serially over 72 h post-treatment and they were analysed by HPLC for ABZ and its metabolites. The ABZ parent drug was not detected in plasma at any time post-treatment, however the metabolites ABZSO and ABZSO2 were recovered in the bloodstream. The active metabolite ABZSO was recovered in plasma between 0.5 and 48 (uninfected), 60 (H. contortus infected) or 72 h (naturally infected sheep) post-administration. The area under the plasma concentration vs time curve (AUC) values for ABZSO were higher in both artificially infected (64.0 micrograms h ml-1) and naturally infected (79.3 micrograms h ml-1) sheep as compared with non-infected animals (41.8 micrograms h ml-1). Peak plasma concentrations for ABZSO and ABZSO2 were higher in both artificially and naturally infected sheep than in non-parasitised animals. No changes in the half-lives and mean residence times for these metabolites were observed in infected sheep. ABZ and its metabolites were found in the abomasum between 0.5 and 48 (infected animals) or 72 h (uninfected) post-treatment. The availability (total AUCs) of ABZ and its metabolites in abomasal fluid were lower in H. contortus infected sheep than in the uninfected control animals. The increased abomasal pH induced by the presence of the H. contortus infection may reduce the plasma/abomasum pH gradient, which results in a decreased ionic-trapping of ABZ and its metabolites in the abomasum. Such a phenomenon correlates with: (a) the higher total AUC values obtained for ABZ metabolites in the bloodstream of the infected compared to the control sheep, (b) the lower concentration profiles of the ABZ parent drug and its metabolites found in the abomasal fluid of the infected animals.