Search PubMedSearch

Biomedical subjects

J F Edwards

Publications and source records attributed to J F Edwards.

At least 19 recordsLinked to original sources

Multiple extrahepatic portosystemic shunts in dogs: 30 cases (1981-1993).

OBJECTIVE: To describe the long-term outcome in dogs with naturally developing multiple extrahepatic portosystemic shunts (PSS). DESIGN: Retrospective case series. ANIMALS: 30 dogs with multiple PSS. PROCEDURE: Medical records of dogs with multiple PSS were reviewed. Follow-up data were obtained by 1 or more of the following methods: recheck at the veterinary teaching hospital (n = 6) or telephone contact with the referring veterinarian (n = 18) or owner (n = 10). The chi 2 or Mann-Whitney rank sum test was used to determine the association of clinical factors with long-term outcome. Survival curves were generated by the Kaplan-Meier product limit method. RESULTS: Median age at diagnosis was 1 year. Findings on exploratory surgery in 25 dogs included ascites; numerous tortuous vessels connecting the portal vein with systemic veins; a small, misshapen liver; and an enlarged portal vein. The most common lesions on histologic evaluation of hepatic tissue specimens were hepatocellular atrophy, portal vascular duplication, cirrhosis, inflammation, and bile duct proliferation. Twelve dogs were treated surgically with vena caval banding, whereas 13 dogs were treated conservatively with dietary restriction of protein and administration of antibiotics, diuretics, and other drugs. Long-term survival and quality of life were similar in dogs from both treatment groups. Median follow-up interval in dogs that survived hospitalization was 24 months (range, 1 to 54 months). CLINICAL IMPLICATIONS: On the basis of these findings, vena caval banding in dogs with multiple PSS is not superior to medical and nutritional treatment.

Animals

Differential diagnosis of chronic fatigue in children: behavioral and emotional dimensions.

A battery of self-report questionnaires and structured diagnostic interviews was administered to 20 children and adolescents who presented to a pediatric specialty clinic with chronic fatigue. Matched groups of healthy and depressed control subjects (aged 8 to 19 years) were also studied. Criteria were established to identify those items in the assessment battery that reliably differentiated among the three groups. Analysis of item content suggested several clusters of characteristics that discriminated among the subject groups, including life changes, cognitive difficulties, negative self-attributions, social relationship disruption, and somatic symptom presentation. The results suggest that certain psychological factors can discriminate chronic fatigue from depressive symptomatology, as well as normal functioning. Items discriminating among groups are presented in an organized questionnaire format to assist with the understanding and assessment of pediatric chronic fatigue cases.

Adolescent

Bacteriologic culture and histologic examination of samples collected from recumbent cattle at slaughter.

OBJECTIVE: To evaluate the potential food safety risks constituted by recumbent cattle that are slaughtered for edible beef. DESIGN: Prospective case series. ANIMALS: Thirty cattle in recumbency that passed a routine antemortem inspection at a US federally inspected abattoir. PROCEDURE: Aerobic, bacteriologic culture of blood samples taken immediately prior to slaughter and of spleens taken during viscera inspection. Gross lesions were recorded, and samples of liver, lung, kidney, and heart were collected from each animal for routine light microscopic examination. RESULTS: Bacteremia caused by Salmonella dublin was documented in 1 cow that had arthritis. Two other cows were condemned after postmortem inspection: 1 because of pneumonia and pleuritis and the other because of vegetative endocarditis. Three carcasses were retained and later condemned because of antibiotic residues in tissues; 1 of these cows had mastitis, 1 had liver abscesses, and 1 was the cow with vegetative endocarditis. Sarcocystosis was found in 27 of 30 hearts, but other clinically important histologic lesions were observed only in liver samples. In 11 of the 30 cows, multifocal, microscopic foci of hepatitis were observed, suggesting that terminal embolic bacterial showering of the liver had occurred in these animals. Liver samples were not submitted for bacteriologic culture. CLINICAL IMPLICATIONS: Most recumbent cows slaughtered for edible beef are not contaminated by bacteria; however, the viscera from these animals may present a food safety danger. Efforts should be made to develop rapid tests to identify bacteremic animals at slaughter and to more fully evaluate terminal showering of viscera by bacteria in cattle at slaughter.

Abattoirs

Vertebral fracture associated with trauma during movement and restraint of cattle.

Two female Limousin calves in a group of 68 calves suffered fractures of a lumbar vertebra subsequent to moving through a chute and being restrained to facilitate administration of vaccines. One calf collapsed as it exited the chute, whereas the second calf collapsed 10 minutes after it was released from the chute. Both heifers were euthanatized. The fractures, of the first lumbar and of the third lumbar vertebral bodies, respectively, were not associated with mineral imbalances. Fractures were determined to be the result of calves attempting to escape through a gap formed by erosion of the area beneath a gate in the holding pen of the corral system. By moving cattle in such a way as to bypass the gate, further injuries were avoided. The calves described here underscore the importance of the use of corral systems appropriate for cattle of various sizes and the necessity of maintaining properly repaired corral systems to prevent injuries to cattle.

Animal Husbandry

Changes in the intestinal mucosal cell populations of German shepherd dogs fed diets containing different protein sources.

Sixteen German Shepherd Dogs from 4 litters were IgA-deficient on the basis of at least 1 of 2 serum IgA determinations, and all had small intestinal bacterial overgrowth, as documented by quantitated small intestinal bacterial culture in another study. These dogs were fed 2 diets that differed principally in their protein source (chicken vs beef, milk, and wheat). All dogs were fed each diet for 2 weeks before the study began. Next, all dogs were fed the chicken-based diet for 2 months. Then, half the dogs (group 1) were randomly assigned to continue eating the chicken-based diet, while the other half (group 2) ate a diet containing beef, milk, and wheat proteins. The small intestine was biopsied at the beginning of the study and after dogs had eaten the assigned diet for 2 and 4 months. At 2 months, group-2 dogs had more colonic mucosal mast cells, but this difference did not persist at 4 months. At the end of the study (ie, 4 months), although all dogs were clinically normal, group-2 dogs had significantly (P = 0.010) decreased numbers of jejunal villus plasma cells. However, these histologic changes were not considered clinically important. There were no significant differences in blood eosinophil counts, serum trypsin-like immunoreactivity, or cobalamin, folate, or IgA concentration. Clinical differences were not detected between the 2 groups, before or after the study. Changes were seen in serum IgM and IgG concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

Case control study of chronic fatigue in pediatric patients.

OBJECTIVE: To determine the demographic characteristics, medical features, psychological profile, and natural history of children with chronic fatigue. DESIGN: Case control study. SETTING: Pediatric Infectious Diseases Clinic of Kosair Children's Hospital, 1990 to 1992. PARTICIPANTS: Forty-four patients referred for persistent fatigue were evaluated. Twenty patients participated in a psychological study; 20 healthy controls of similar age and gender were recruited from community pediatric practices and 20 matched depressed controls were recruited from university psychiatry services (subjects were treated as groups in the analyses). MEASURES: Demographic data were obtained for all referred patients. Those with fatigue for at least 2 months and no alternative diagnosis received a detailed history, physical, and battery of laboratory tests (complete blood count, sedimentation rate, chemistry panel, chest X-ray thyroid stimulating hormone, thyroxine, anti-nuclear antibodies, urinalysis, immunoglobulins, and Epstein-Barr virus (EBV), toxoplasma, and cytomegalovirus serologies). Psychological study participants completed the following: background structured interview; Kaufman Brief Intelligence Test; Children's Depression Inventory; Child Behavior Checklist; Youth Self Report; Diagnostic Interview for Children and Adolescents-Revised; mail-in follow-up survey. RESULTS: The median age of fatigue patients was 14.3 years; 60% were female, 96% white, and 87% from the mid/upper socioeconomic status (SES). Fatigue patients were demographically similar to 21 patients referred for infectious mononucleosis (IM) but were older than other clinic patients (P < .0001). White race (P = .0568) and mid/upper SES (P = .0403) were over-represented among fatigue patients compared to patients referred for other diagnoses. Of 36 patients meeting criteria for further study, 5 had an IM-like illness including evidence of recent EBV infection. For the remaining 31 patients, clinical and laboratory evaluations were unrevealing. Psychological study subjects reported marked declines in quality-of-life and scored high on measures of internalizing, withdrawal, and social isolation. Nine met diagnostic criteria for depression, although depressive symptoms were not as prominent as those reported by depressed controls. Fatigue subjects scored higher on somatization than both control groups. The follow-up survey indicated symptomatic improvement in most patients. CONCLUSIONS: Chronic fatigue was a common reason for referral, with over-representation of white children from mid/upper SES. After exclusion of EBV-associated IM, screening laboratory tests were not helpful in establishing specific organic diagnoses. Whereas the natural history was favorable, chronic fatigue resulted in major quality-of-life changes and was associated with significant levels of psychosocial distress. IMPLICATIONS: Psychological evaluation is warranted in these patients, as some may have treatable psychological conditions. Given the absence of proved medical therapies, psychosocial interventions to improve quality-of-life should be studied.

Adolescent

Ventral pararectal approach to the seminal vesicles of bulls.

Results of bilateral seminal vesiculectomy on 4 clinically normal bulls indicated that a ventral pararectal approach can be done to gain exposure to the seminal vesicles without excessive risk of postoperative complications or alterations in the bull's ability to develop and maintain an erection or to ejaculate semen. Advantages of the ventral pararectal approach over the lateral approach to the seminal vesicles are that all dissection is on the midline between the rectum and pelvic urethra and the prevalence of intraoperative hemorrhage and postoperative hematoma formation is decreased. Additionally, the potential to damage nerves that lie adjacent to the rectum and pelvic urethra is reduced. Consequently, bladder atony and ejaculatory failure are less likely to develop after seminal vesiculectomy via a ventral pararectal approach.

Animals

Cache Valley virus.

Cache Valley Virus (CVV) is a causative agent of a mosquito-borne disease syndrome of sheep and, possibly, of all ruminants, characterized by embryonic and fetal death, stillbirths, and multiple congenital malformations. CVV is endemic in Canada, Mexico, and the United States. Several related Bunyaviruses also may play a role in syndromes of congenital malformations and embryonic losses in North America.

Abnormalities, Multiple

Juvenile-onset neuronal ceroid-lipofuscinosis in Rambouillet sheep.

Two, 8-month-old Rambouillet half-sister ewes with signs of visual loss and decreased mentation were examined. Ewe No. 1 was necropsied at 10 months of age, and after being held under observation for a further 6 months, ewe No. 2 was necropsied at 16 months of age. At that time, the ewe was blind and severely depressed. Both ewes had deposition of an autofluorescent lipopigment, identified as ceroid-lipofuscin, in neurons of the brain, spinal cord, eye, and dorsal root ganglia. The disease process was progressive and characterized by deposition of lipopigment with neuronal degeneration and severe fibrillary astrogliosis. This progressive loss of neurons in the older ewe led to severe retinal degeneration. No pigment was observed in cells outside of the nervous system and eye. Controlled breeding studies have shown that this disease has an autosomal, recessive inheritance. The disease referred to here as juvenile-onset neuronal ceroid-lipofuscinosis of Rambouillet sheep is unlike the majority of the hereditary ceroid-lipofuscinoses that occur in human beings and animals in that only the nervous system is affected. Therefore, this disease could serve as an excellent model for the study of lipopigment deposition that affects the nervous system as a result of various disease states and during aging.

Animals

Evaluation of the developmental toxicity of citrinin using Hydra attenuata and postimplantation rat whole embryo culture.

Citrinin (a mycotoxin produced as a frequent contaminant of food and feed by numerous species of Aspergillus and Penicillium fungi) is embryo/fetotoxic and embryocidal in mice and rats. The present study was designed to examine whether the in vivo observed developmental toxicity of citrinin could be recapitulated using the Hydra attenuata (HA) bioassay and then be confirmed in rat whole embryo culture (WEC). Results from the HA assay indicated that the minimal affective concentrations of citrinin required to elicit a toxic response in the adult hydra (MACA) and in the regenerating hydra (MACD) were 30 mg/l and 20 mg/l, respectively. The Hydra developmental hazard index (A/D ratio) was equal to 1.5, classifying citrinin as a coaffective developmental toxin. In WEC, rat embryos were cultured in homologous (rat) serum containing citrinin at various concentrations ranging from 0.0 and 300 micrograms/ml for a period of 45 h. The results indicated a concentration-dependent reduction in yolk sac diameter, crown-rump length, somite number, protein and DNA contents. No embryonic dysmorphogenesis was observed in any treatment group. Histological examination revealed severe diffuse mesodermal and ectodermal necrosis in embryos treated with 250 micrograms/ml citrinin. At lower concentrations of citrinin, embryos were neither grossly nor histologically different from controls. Both the HA and WEC bioassays demonstrated that citrinin is not a primary developmental toxin. The use of HA and WEC bioassays in tandem may facilitate the rapid detection and ranking of the developmental hazards of food and feedborne mycotoxins.

Animals

Analysis of multiple mRNAs from pathogenic equine infectious anemia virus (EIAV) in an acutely infected horse reveals a novel protein, Ttm, derived from the carboxy terminus of the EIAV transmembrane protein.

Transcription of pathogenic equine infectious anemia virus (EIAV) in an acutely infected horse was examined by using the polymerase chain reaction and nucleotide sequencing. Four spliced transcripts were identified in liver tissue, in contrast to the multiplicity of alternatively spliced messages reported for in vitro-propagated human immunodeficiency virus, simian immunodeficiency virus, and, to a lesser extent, EIAV. Nucleotide sequence analysis demonstrated that three of these mRNAs encode known viral proteins: the envelope precursor, the product of the S2 open reading frame, and the regulatory proteins Tat and Rev. The fourth transcript encodes a novel Tat-TM fusion protein, Ttm. Ttm is a 27-kDa protein translated from the putative tat CTG initiation codon and containing the carboxy-terminal portion of TM immediately downstream from the membrane-spanning domain. p27ttm is expressed in EIAV-infected canine cells and was recognized by peptide antisera against both Tat and TM. Cells transfected with ttm cDNA also expressed p27ttm, which appeared to be localized to the endoplasmic reticulum or Golgi apparatus by indirect immunofluorescence. The carboxy terminus of lentiviral TM proteins has previously been shown to influence viral infectivity, growth kinetics, and cytopathology, suggesting that Ttm plays an important role in the EIAV life cycle.

Amino Acid Sequence

Rectal hemorrhage associated with vascular ectasia in a young dog.

Rectal bleeding in a 7-month-old 13-kg sexually intact female mixed-breed dog was determined to be associated with vascular ectasia of the small intestine, descending colon, rectum, and anus. Microscopically, the telangiectasia was associated with lymphangiectasia and focal ulceration. Surgical intervention resulted in incomplete resection of the lesion and only temporary amelioration of clinical signs. The dog's age was compatible with a congenital origin for the defect, but an acquired cause could not be excluded.

Angiodysplasia

Amebic meningoencephalitis in a sheep.

A 1.5-year-old Suffolk ewe with acute onset of incoordination and blindness unresponsive to antibiotic treatment was examined at necropsy. The meninges were congested, opaque, and thick. Microscopically, focal areas of hypercellularity in the left cortical gray matter and the meninges were observed. The inflammatory response consisted of gliosis and perivascular cuffing (lymphocytes, plasma cells, and variable numbers of eosinophils). An amebic organism in 2 life stages was found in the cerebral parenchyma. Numerous large (15 to 35 microns in diameter) organisms, interpreted as trophozoites, were characterized by vacuolated cytoplasm and small nuclei with a prominent eosinophilic nucleolus (karyosome). The smaller (10 to 17 microns in diameter) encysted stage was surrounded by a capsule-like membrane, and contained a large central body sometimes surrounded by a clear halo. Immunofluorescence studies for amebic antigens were strongly positive for an ameba recently isolated in human beings and baboons (Leptomyxid sp).

Amebiasis

Idiopathic muscular hypertrophy of the equine small intestine: 11 cases (1980-1991).

The medical records of 11 horses with idiopathic muscular hypertrophy (MH) of the small intestine were reviewed to determine the clinical and pathological features of the disease. The median age of affected horses was 10.0 years (range 5-18 years). No breed or sex predisposition was apparent. Ten horses (91%) had chronic (23 days to 2.4 years) signs of mild, intermittent colic, and 1 horse had signs of severe colic of only 3 days' duration. Partial anorexia and chronic weight loss of variable duration (1-6 months) were prominent historical findings in 5 (45%) horses. Diagnostic tests, with the exception of exploratory caeliotomy, were ineffective for definitive diagnosis of intestinal MH as a cause of colic. In 2 horses, however, a thickened, rigid ileum was detected by palpation per rectum, and in 5 horses, multiple loops of distended small intestine were detected by palpation per rectum. Hypertrophy of both the circular and longitudinal layers of muscularis was determined as the cause of intestinal thickening in all horses. Muscular hypertrophy of the ileum was present in 9 (82%) horses. Two horses (18%) had MH of a section of jejunum only, and 4 (36%) horses had MH of the ileum in combination with MH of other sections of small intestine. Two (18%) horses had MH of the entire small intestine. In 9 (82%) horses, intestinal MH resulted in narrowing of the luminal diameter at the site of MH. Small diverticula were present on the mesenteric border of the hypertrophied ileum of 5 (45%) horses. Five linear (up to 150-cm) diverticula were present in the hypertrophied jejunum of 1 (9%) horse. Haemomelasma ilei was present on the antimesenteric serosal surface of affected intestine of 8 (73%) horses. Full-thickness rupture of the ileum with subsequent diffuse, septic peritonitis occurred in 3 (27%) horses.

Animals