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Biomedical subjects

C M Hendrix

Publications and source records attributed to C M Hendrix.

At least 19 recordsLinked to original sources

Macracanthorhynchus ingens infection in a dog.

A 4-month-old sexually intact female Siberian Husky was examined because of diarrhea and 4 flesh-colored annulated helminths that were recovered from the dog's feces. Infection with Macracanthorhynchus ingens was diagnosed on the basis of morphologic features of the adult parasites and ova. Spindle-shaped eggs (mean length, 91 microm; mean width; 54 microm) were obtained from the body cavity of a gravid female specimen. The dog was treated empirically with epsiprantel (5.5 mg/kg [2.5 mg/lb] of body weight) and ivermectin (250 to 500 microg/kg [114 to 227 microg/lb]), and the diarrhea resolved. Infection with this parasite has been reported in raccoons from the same geographic area. Macracanthorhynchus ingens is typically a parasite of raccoons, wolves, badgers, foxes, skunks, mink, and moles; transmission from wildlife to dogs may occur via ingestion of infected intermediate hosts (millipedes).

Acanthocephala↗

A survey of reading, writing, and oral communication skills in North American veterinary medical colleges.

In the 1989 report by the Pew National Veterinary Education Program (PNVEP), communication skills topped the list of characteristics the veterinary graduate should possess in order to function effectively in the twenty-first century. To determine the reading, writing, and oral communication requirements and opportunities in veterinary curricula in the US and Canada, and to determine the perceived communication tasks that might be commonly required of practicing veterinarians in the next century, we sent a 15-item communications skills questionnaire to the academic deans of the 31 veterinary curricula in the US and Canada. The results reinforce the importance of communication skills in veterinary medicine, as detailed by the PNVEP over 10 years ago. Based on the responses to our questionnaire and on our own experiences with veterinary medical students, we make several recommendations to enhance communication instruction in veterinary medical curricula.

Canada↗

Large-scale screening assay to measure epidermal growth factor internalization.

Recently, we showed that the internalization of the epidermal growth factor (EGF) receptor is inhibited by hydrogen peroxide (H(2)O(2)) in human fibroblasts. In order to test the effect of various stress conditions on receptor internalization and to test a variety of antioxidants in their capacity to prevent or reduce the H(2)O(2)-induced inhibition of internalization, a screening assay was developed to measure the internalization in 96-well plates. In this assay, cells are exposed to biotin-conjugated EGF and the amount of internalized EGF is detected with horseradish peroxidase-conjugated streptavidin. We show that the results obtained by this new assay are comparable with those from internalization studies performed with radioactive labeled EGF. Therefore, the cellular internalization assay as presented here is a reliable method to measure EGF receptor internalization. Moreover, because elaborate processing of the cells is not required, the assay is a relatively fast and inexpensive method to study ligand-induced internalization in 96-well plates and thereby is suitable for large-scale screening of compounds or conditions interfering with this internalization.

3T3 Cells↗

Furunculoid myiasis in a dog caused by Cordylobia anthropophaga.

Two days after returning with its owners from a 60-day visit to Liberia, an 8-year-old 6.5-kg spayed female Miniature Schnauzer was examined by a veterinarian in the United States. A 1.0 x 1.0-cm raised erythematous nodule was noticed on the medial aspect of the right pinna. In the center of the nodule was a 1.0 x 1.0-mm pore from which a 0.5 x 0.5 x 1.0-cm white larva was extracted. The larva was identified as a third-stage larva of Cordylobia anthropophaga, the African Tumbu fly, a fly restricted to sub-Saharan Africa. Cordylobia anthropophaga does have zoonotic potential, but the owners did not have any skin lesions. Detection of C anthropophaga in the United States warranted reports to state and federal authorities and personnel at the Centers for Disease Control and Prevention. The situation described here illustrated the potential of tourists' pets to import foreign diseases.

Alabama↗

Efficacy of lufenuron against developmental stages of fleas (Ctenocephalides felis felis) in dogs housed in simulated home environments.

Twenty-four, adult, female Beagles were arranged by body weight from greatest to least and allocated to 2 groups of 12 dogs, using random numbers. Dogs were housed collectively in 2 adjacent metal buildings, each divided into 4 rooms measuring 2.1 x 3.7 m. Each room was paneled and carpeted and had an access door to the outside with a connecting run that measured 2.1 x 9.1 m. Each run had a surface consisting of 5 cm of pea gravel overlaying 5 cm of sand, and was partially covered by an awning that provided shade at its proximal end. For placement in room/run units, dogs in each of the treated and control groups were alloted to 4 subgroups of 3 dogs each. Each subgroup of dogs was placed in a separate room/run unit. Units containing treatment or control subgroups were alternated to avoid placing identically treated subgroups adjacent to each other. Dogs of subgroups A, C, E, and G were treated with lufenuron monthly at a minimal target dosage of 10 mg/kg of body weight; those of subgroups B, D, F, and H were treated with excipient tablets. Dogs were treated on study days 7, 37, 68, and 98. Each dog was infested with 100 newly emerged, unfed, insectary-reared, adult Ctenocephalides felis on each of study days 0 and 2. Thereafter, infestations on all dogs were dependent on continued development of fleas either in the indoor or outdoor environment. Numbers of fleas on each of the treated and control dogs were determined, using a nondestructive counting technique on days 6, 14, 21, 28, 35, 56, 70, 84, 98, 112, and 119.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Efficacy of milbemycin oxime against naturally acquired or experimentally induced Ancylostoma spp and Trichuris vulpis infections in dogs.

The efficacy of milbemycin oxime was evaluated at dosages of 0.25, 0.50, and 0.75 mg/kg of body weight in dogs naturally infected with mature Ancylostoma spp, at a dosage of 0.50 mg/kg in dogs with experimentally induced immature and mature A caninum, and at dosages of 0.55 to 0.86 mg/kg in dogs naturally infected with mature Trichuris vulpis. Milbemycin oxime was 95 and 99% effective against mature Ancylostoma spp at dosages of 0.50 and 0.75 mg/kg, respectively, but only 49% effective at a dosage of 0.25 mg/kg. Efficacy was 49% against pulmonary L3-L4 stages of A caninum (36 hours after inoculation), greater than 80% against L4 (120 hours after inoculation) and early L5 stages (216 hours after inoculation), and greater than 90% against experimentally induced mature stages (360 hours after inoculation). Milbemycin oxime was also 97% effective in the removal of mature Tr vulpis from naturally infected dogs. Adverse reactions were not observed following treatment in any of the dogs.

Ancylostomiasis↗

Dirofilariasis.

Explore the source record for details and available documents.

Animals↗

Determination of homovanillic acid, 5-hydroxyindoleacetic acid and pressure in the cerebrospinal fluid of collie dogs following administration of ivermectin.

Twelve adult Collie dogs were studied to determine the effects of ivermectin on neurotransmitter metabolites released from the brain into the cerebrospinal fluid (CSF) and on CSF pressure. Ten of the 12 Collies were given ivermectin orally at a concentration of 200 micrograms/kg body weight. Three of these 10 Collies showed clinical signs of ivermectin-induced toxicosis which progressed into a state of unresponsive recumbency in 2 dogs. Cerebrospinal fluid pressures and neurotransmitter metabolite concentrations in cisterna magna CSF were analysed 49 to 50 hours after administration of ivermectin in 6 of the 10 treated dogs, and in the 2 untreated control Collies. Cerebrospinal fluid pressures were within normal limits in all dogs. However, compared to the CSF concentrations in the 2 untreated and 3 non-reactive Collies, the 2 ivermectin-reactive Collies still in recumbency had elevated CSF concentrations of homovanillic acid (HVA), a metabolite of dopamine, and 5-hydroxyindoleacetic acid (5-HIAA), a metabolite of serotonin. These findings suggest an association between altered neurotransmission and severe ivermectin-induced neurological abnormalities. No evidence of elevated intracranial pressure was found.

Animals↗

Controlled dosage titration of febantel paste in naturally parasitized cattle.

A controlled anthelmintic trial was conducted to determine the efficacy of febantel paste (45.5%) at dosages of 2.5, 5.0, 7.5, and 10.0 mg/kg in calves harboring natural gastrointestinal nematode infections. Dosages of 5.0, 7.5 and 10.0 mg of febantel/kg of body weight were greater than 96% effective in removing adults of Haemonchus contortus, Ostertagia spp, Cooperia spp, and Oesophagostomum radiatum. The 2.5 mg/kg dosage was considered suboptimal because of low efficacy against Ostertagia and Cooperia spp. Efficacies against Trichostronglylus axei, Trichuris spp, Bunostomum phlebotomum, and Stronglyloides papillosus were difficult to determine because fewer numbers of these nematodes were recovered. Efficacies of febantel paste against immature bovine parasites ranged from 83.62% to 97.72%.

Animals↗

Comparison of serologic tests for detection of antigen in canine heartworm infections.

In 30 random-source dogs, we determined sensitivity and specificity of 5 serologic tests for detection of canine heartworm antigens. Seventeen of the dogs were infected naturally with adult Dirofilaria immitis, and 4 of the infected dogs were amicrofilaremic. The ability of the serologic tests to predict whether a dog was infected or uninfected (overall test accuracy) ranged from 73 to 97%. Sensitivity was not affected by circulating D immitis microfilariae, but was markedly influenced by the number of adult D immitis present. False-positive reactions were rare and were not associated with intestinal parasites or Dipetalonema reconditum microfilariae. Modifications of some of the test procedures were necessary to maximize test accuracy and reproducibility. These modifications and other technical details might limit the usefulness of some of the tests in a veterinary practice.

Animals↗

Inactivation of Giardia lamblia and Giardia canis cysts by combined and free chlorine.

Free chlorine and a combined organic N-chloramine (3-chloro-4,4-dimethyl-2-oxazolidinone, compound 1) were compared for efficacy as disinfectants against an admixture of cysts of Giardia lamblia and Giardia canis in water solution under a variety of test conditions; variables were pH, temperature, and water quality. In general, compound 1 was found to reduce the giardial excystation in the solutions at lower concentration or shorter contact time at a given total chlorine concentration than did free chlorine.

Analysis of Variance↗

Experimental Cryptosporidium parvum infections in opossums (Didelphis virginiana).

Five nursing opossums (Didelphis virginiana) were each inoculated with 5 x 10(6) Cryptosporidium parvum oocysts of calf origin. Following inoculation, endogenous stages of C. parvum were observed in the ileum, cecum, and colon of these opossums. Two of three noninoculated pouch mates acquired infections during the study based on examinations of feces and tissue sections of all eight opossums. Mild diarrhea was observed in four of seven opossums harboring C. parvum, although none died as a result of the infection. Under the conditions of this study, C. parvum appeared to be only mildly pathogenic for opossums.

Animals↗

Anatrichosoma sp infection in a dog.

Embryonated, double-operculated eggs were observed during routine examination of a fecal specimen from a 5-month-old dog. Similar eggs were found on a skin scraping of a raised, flaking, erythematous nodule on the dorsal midline in the lumbar region. Eggs were identified as being similar to those of Anatrichosoma spp. After surgical excision, histologic examination of the nodule revealed nematodes with morphologic features consistent with those of Anatrichosoma spp.

Animals↗

Whipworms and intestinal threadworms.

Whipworms (genus Trichuris) parasitize the lower bowel of humans, domestic animals, and wild animals. The species of Trichuris that are important in small animal practice are T. vulpis in the dog and T. campanula and T. serrata in the cat. Intestinal threadworms (Strongyloides stercoralis in the dog and S. tumefaciens in the cat) parasitize the small intestine. The identification of whipworms and threadworms, their life cycles, and the diagnosis, treatment, and control of infection are discussed in this article.

Animals↗