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Biomedical subjects

M D Willard

Publications and source records attributed to M D Willard.

69 records · Page 4Linked to original sources
PubMed1978

Morphologic evaluation of IgM cells of the canine small intestine by fluorescence microscopy.

Biopsies of small intestine from 7 dogs were examined by fluorescence microscopy to determine the number of IgM-containing cells in the lamina propria. Biopsies were taken from duodenum, jejunum, and ileium. (Cell counts were made by 2 persons to demonstrate reproducibility.) There were 452.24 +/- 60.09 cells per mm2 in the duodenum 572.68 +/- 62.13 cells per mm2 in the jejunum, and 107.47 +/- 59.57 cells per mm2 in the ileum. All sections were cut at 6 micrometer. The ileum had fewer cells than either duodenum or jejunum (P = 0.000038 and 0.00001, respectively), whereas duodenum and jejunum did not differ significantly in numbers of cells (P = 0.17528). Quantifying autofluorescent cells in the same sites showed no significant differences among the 3 tissues (P = 0.24697). The autofluorescent cells differed in intensity and morphology from the IgM cells. These two observations tend to support the contention that the autofluorescent cells did not bias the IgM cell counts at the 3 sites. Total autofluorescence (cells, collagen, and vessels) was higher in the ileum than in either the jejunum or the duodenum (P = 0.04967 and 0.03050, respectively). However, all 3 categories counted (IgM cells, autofluorescent cells, and autofluorescent structures) had significant dog-tissue interactions. This will necessitate determining normals for each age-sex-breed category of dog studied.

Animals↗
PubMedDate not supplied

Short-bowel syndrome in four dogs.

Short bowel syndrome occurred in four dogs after extensive (74% to 88%) small intestinal resection. Weight loss and diarrhea were the principal clinical signs. Treatment was based on the severity of clinical signs. One dog is alive after 27 months. Three dogs died within 3 months. The prognosis depends on the extent and site of resection, degree of intestinal adaptation, preoperative condition, and postoperative care.

Anastomosis, Surgical↗
PubMedDate not supplied

The educational pelvic examination. Women's responses to a new approach.

To compare the reactions of women to educational and traditional formats of the pelvic examination, a convenience sample of 213 women with divergent demographic characteristics was selected from the practices of six nurses and physicians. After random assignment to educational or traditional groups, all subjects completed a questionnaire developed by the researchers that assessed preexisting attitudes toward pelvic examination. All subjects were then examined with either the educational or traditional method. Afterwards, all subjects completed a second questionnaire, which assessed their responses to the recent examination. The educational and traditional groups' preexisting attitudes toward pelvic examination did not differ significantly. After experiencing the pelvic examination, however, the educational group demonstrated significantly more positive attitudes toward the examination.

Attitude to Health↗
PubMedDate not supplied

Acquired myasthenia gravis. Selective involvement of esophageal, pharyngeal, and facial muscles.

Serum samples from 152 dogs with a clinical diagnosis of idiopathic megaesophagus without detectable generalized muscle weakness were tested for the presence of antibodies to acetylcholine receptors by immunoprecipitation radioimmunoassay. Positive serum antibody titers (mean, 3.1 nmoL/L; range, 0.77-30 nmoL/L; reference values less than 0.6 nmoL/L) were found in 40 dogs (26%), with German Shepherd dogs (8/25, 32%) and Golden Retrievers (7/20, 35%) having a greater percentage of positive submissions. By immunocytochemical methods, localization of immune complexes at the neuromuscular junction after incubation of serum with normal canine muscle was documented in an additional 17 cases (11% of all samples submitted) that did not have increased antibody titers to acetylcholine receptors. Of the 40 seropositive dogs, 17 (48%) had a clinical improvement or remission of clinical signs associated with decreasing AChR antibody titers. Idiopathic megaesophagus has been associated with a poor prognosis; however, this study demonstrates that a large percentage of the dogs have myasthenia gravis and that with supportive treatment, the clinical signs may improve or resolve.

Animals↗
PubMedDate not supplied

Itraconazole for the treatment of histoplasmosis in cats.

Eight cats with histoplasmosis were treated with itraconazole at 5 mg/kg per dose PO bid. There were multiple sites of infection, and 2 of the cats had hypercalcemia that was attributed to the histoplasmosis. All 8 cats were eventually cured, but 2 cats experienced recurrences of disease after completion of therapy, requiring 2 to 3 additional months of itraconazole. There were no clinically relevant adverse effects during treatment. Although a limited number of cats were treated, the study suggests that itraconazole is a well-tolerated and effective drug for the treatment of histoplasmosis in the cat.

Administration, Oral↗
PubMedDate not supplied

Efficacy of omeprazole for the prevention of exercise-induced gastritis in racing Alaskan sled dogs.

Exercise-induced gastritis and gastric ulcers are common in humans and horses, and recently have been described in racing sled dogs. The cause of exercise-induced gastric disease is not completely understood in any species, but pharmacologic suppression of acid secretion is an effective treatment in humans and horses. Thus, we tested the hypothesis that omeprazole, a proton-pump inhibitor shown to reduce gastric acid secretion in dogs, would reduce the severity of exercise-induced gastric disease. Three teams of 16 dogs each competing in the 2002 Iditarod Sled Dog Race were recruited for participation. Within each team, dogs were randomly assigned to either treatment (20 mg omeprazole PO q24h) or placebo. Treatments were administered until either completion of the race or withdrawal of an individual dog from competition. Gastric endoscopy was performed in all dogs 24 hours after completion or withdrawal, and the gastric mucosa was scored by using a subjective severity score (0 = normal, 3 = numerous bleeding ulcers). Treatment with omeprazole significantly reduced mean gastric severity score compared to placebo (omeprazole: 0.65 +/- 0.17, placebo: 1.09 +/- 0.18; P = .028), but also was associated with increased frequency of diarrhea during the race (omeprazole 54%, placebo 21%; P = .017). Examination of our data suggests that omeprazole may be an effective treatment for exercise-induced gastric disease in racing sled dogs. However, further investigation regarding the cause and clinical relevance of diarrhea associated with omeprazole treatment must be conducted before omeprazole can be recommended for routine prophylactic treatment in these athletes.

Alaska↗
PubMedDate not supplied

Prevalence of gastric lesions in racing Alaskan sled dogs.

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.

Alaska↗
PubMedDate not supplied

Intestinal crypt lesions associated with protein-losing enteropathy in the dog.

Six dogs were diagnosed with protein losing enteropathy (PLE). There was no evidence of inappropriate inflammatory infiltrates or lymphangiectasia in multiple mucosal biopsies of the small intestine of 4 of the dogs. The 5th and 6th dogs had obvious lymphangiectasia and a moderate infiltrate of inflammatory cells in the intestinal mucosa. All 6 dogs had a large number of dilated intestinal crypts that were filled with mucus, sloughed epithelial cells, and/or inflammatory cells. Whether PLE occurs in these dogs because of protein lost from the dilated crypts into the intestinal lumen or whether the dilated crypts are a mucosal reaction due to another undetermined lesion that is responsible for alimentary tract protein loss is unknown. However, when large numbers of dilated intestinal crypts are present, they appear to be associated with PLE even if there are no other remarkable lesions in the intestinal mucosa.

Animals↗
PubMedDate not supplied

Presumptive, iatrogenic gastric outflow obstruction associated with prior gastric surgery.

Iatrogenic gastric outflow obstruction in two dogs appeared to be caused by prior gastric surgery. The obstructions were believed to be anatomical rather than functional based on endoscopic examinations. Initially, the dogs had been evaluated and each had received two abdominal surgeries because of gastrointestinal bleeding, vomiting, or both. Eventually, both dogs were euthanized due to complications arising after attempted surgical correction of the iatrogenic obstructions. While gastric surgery commonly is performed, it seldom is considered to be a potentially harmful procedure. However, as these cases demonstrate, the decision to perform a gastrotomy must be weighed against possible risks and complications. Iatrogenic gastric outflow obstruction associated with surgery may be prevented by minimizing tissue inversion into the gastric lumen when surgery is performed near the pyloric outflow tract. Additionally, when large lesions near the pylorus are resected surgically, preservation of the continuity of the outflow tract is necessary.

Adenocarcinoma↗
PubMedDate not supplied

Food intolerance mimicking alimentary lymphosarcoma.

A cat with chronic diarrhea was diagnosed as having duodenal lymphosarcoma on two separate sets of endoscopic biopsies. Prednisolone failed to effect any clinical improvement. However, feeding the cat with a hypoallergenic diet resulted in long-term (i.e., six months) resolution of clinical signs. Most clinicians are familiar with the possibility of mistakenly diagnosing inflammatory bowel disease when the patient has lymphosarcoma; however, this case had the opposite problem: lymphosarcoma was diagnosed histologically on two separate occasions when inflammatory bowel disease was the problem.

Animals↗
PubMedDate not supplied

Pharmacokinetics and suggested oral dosing regimen of cisapride: a study in healthy cats.

The disposition of cisapride in seven healthy cats was determined following administration of either a single oral (2 mg/kg body weight) or intravenous (i.v.) (1 mg/kg body weight) dose. Cats were studied using a random crossover design. After administration of the oral capsule, maximum plasma drug concentration (Cmax) +/- standard deviation (SD) was 73.32 +/- 16.59 ng/ml, and bioavailability +/- SD was 29.0 +/- 22.6%. Following i.v. administration, extrapolated peak cisapride concentration (C0) +/- SD was 421.30 +/- 155.37 ng/ml, and clearance +/- SD was 15 +/- 0.67 ml/kg per minute. Elimination half-life (T1/2) was similar for both routes of administration (T1/2(oral) +/- SD was 5.27 +/- 3.16 hr, T1/2(i.v.) +/- SD was 5.19 +/- 3.77 hr). Adverse effects were not observed. Based on these results, a dose of 1 mg/kg body weight per os (PO) every eight hours or 1.5 mg/kg body weight every 12 hours is expected to result in plasma drug concentrations within the therapeutic ranges established for humans.

Administration, Oral↗
PubMedDate not supplied

Physaloptera infection in 18 dogs with intermittent vomiting.

Physaloptera infections were diagnosed endoscopically in 18 dogs. Each case had vomiting as the primary clinical sign, and four cases had regurgitation as a concurrent sign. Fecal flotations, using magnesium sulfate solution, were performed in 12 of the 18 cases and were negative for Physaloptera eggs. In 12 of the 18 cases, only one worm was seen during endoscopic examination. Fifteen of 18 cases were treated with pyrantel pamoate, and 10 of 12 cases with follow-up had resolution of their vomiting.

Animals↗
PubMedDate not supplied

Cryptosporidiosis, coccidiosis, and total colonic mucosal collapse in an immunosuppressed puppy.

An eight-week-old puppy with chronic diarrhea was diagnosed with simultaneous opportunistic pathogens (i.e., cryptosporidiosis, coccidiosis) and total colonic mucosal collapse. Lack of lymphoid follicles in the spleen and lymph nodes suggested a primary underlying immunosuppression that most likely permitted infection with these pathogens. Intensive antibiotic therapy was most likely responsible for the severe colonic lesion, and bismuth subsalicylate administration in this severely dehydrated puppy may have contributed to renal failure as the ultimate cause of death.

Animals↗