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Biomedical subjects

J W Simpson

Publications and source records attributed to J W Simpson.

At least 19 recordsLinked to original sources
PubMed2002

Canine dysautonomia: two clinical cases.

Two clinical cases of canine dysautonomia are described. Two young female neutered dogs were presented with clinical signs including vomiting, diarrhoea, faecal tenesmus, dysphagia and urinary retention. Decreased tear production, dry mucous membranes, bilateral Horner's syndrome, decreased anal sphincter tone and gastrointestinal hypomotility were also observed. Presumptive diagnoses of dysautonomia were made based on the clinical presentation and investigations. Postmortem histopathological examination in one of the cases demonstrated marked depletion of neuronal cell bodies in the intestinal myenteric plexuses and parasympathetic ganglia, confirming the diagnosis in this case. Criteria for aiding the antemortem diagnosis of this rare condition based on clinical observations and diagnostic testing are proposed.

Animals↗
PubMed2002

Association between anal furunculosis and colitis in the dog: preliminary observations.

Treatment of anal furunculosis in dogs is often unsatisfactory and may be associated with significant recurrence and complications. This may be compounded by the simultaneous presence of colitis in affected animals. Clinical signs associated with colitis and anal furunculosis may be similar, including faecal tenesmus, dyschezia and haematochezia. To examine the incidence of concurrent anal furunculosis and colitis, colonic biopsies were collected from 18 dogs referred for treatment of anal furunculosis. Nine dogs (50 per cent) had a histopathological diagnosis of colitis. Clinical signs more indicative of colitis than anal furunculosis (increased frequency of defecation, mucus in faeces and diarrhoea) were not observed more frequently in dogs with confirmed colitis compared with those with furunculosis alone. Therefore, while an association between colitis and anal furunculosis may exist, clinical signs alone cannot be used as an indicator of the presence of colitis in cases of anal furunculosis. The authors recommend that colonic biopsies should be undertaken in all dogs presented with anal furunculosis. Whether specific treatment of colitis in dogs with histopathological evidence of colitis improves the outcome of treatment for anal furunculosis awaits further study.

Animals↗
PubMed2001

Left atrial aneurysm.

Aneurysms of the left atrium are rare abnormalities. They can be congenital or acquired. Whereas a true congenital aneurysm presents as isolated pathology, inflammatory or degenerative processes involving the endocardium are associated with the acquired type. The clinical records of 2 patients with the diagnosis of left atrial aneurysm were reviewed, along with the surgical strategies, current literature, and patient outcomes. Because of the risk of life-threatening complications, surgery is recommended even in asymptomatic cases. Resection and mitral valvuloplasty should be the treatment of choice.

Cardiac Catheterization↗
PubMed2000

A transmission imaging spectrograph and microfabricated channel system for DNA analysis.

In this paper we present the development of a DNA analysis system using a microfabricated channel device and a novel transmission imaging spectrograph which can be efficiently incorporated into a high throughput genomics facility for both sizing and sequencing of DNA fragments. The device contains 48 channels etched on a glass substrate. The channels are sealed with a flat glass plate which also provides a series of apertures for sample loading and contact with buffer reservoirs. Samples can be easily loaded in volumes up to 640 nL without band broadening because of an efficient electrokinetic stacking at the electrophoresis channel entrance. The system uses a dual laser excitation source and a highly sensitive charge-coupled device (CCD) detector allowing for simultaneous detection of many fluorescent dyes. The sieving matrices for the separation of single-stranded DNA fragments are polymerized in situ in denaturing buffer systems. Examples of separation of single-stranded DNA fragments up to 500 bases in length are shown, including accurate sizing of GeneCalling fragments, and sequencing samples prepared with a reduced amount of dye terminators. An increase in sample throughput has been achieved by color multiplexing.

Animals↗
PubMed2000

Ectopia cordis and other midline defects.

BACKGROUND: Thoracic ectopia cordis and other midline defects are rare congenital anomalies that often occur with other intracardiac defects. Despite significant improvements in neonatal and infant cardiac surgeries, operations for thoracoabdominal ectopia cordis carry an extremely high mortality with only a few reported survivors of thoracic ectopia cordis. METHODS: The clinical charts of 4 patients with ectopia cordis over a 6-year period were reviewed. Three of the patients showed varying degrees of Cantrell's Pentalogy; thoracic ectopia cordis was found in 1. We have reviewed our surgical strategies and reported the patients' clinical outcomes. RESULTS: All 4 patients are alive at follow-up. Two infants with double-outlet right ventricle have been fully corrected, and extracorporeal membrane oxygenation was necessary in 1 infant for cardiac failure following the cardiac repair. A newborn with thoracoabdominal ectopia cordis underwent primary repair of his diaphragmatic defect, and a silo was used to progressively reduce the omphalocele. He is currently awaiting elective repair of tetralogy of Fallot. Lastly, the patient with thoracic ectopia cordis underwent successful soft tissue coverage, and she is being followed in the clinic with restrictive muscular ventricular septal defects and a left ventricular diverticulum. CONCLUSIONS: Our experience along with other reports in the literature demonstrates that patients with thoracic and thoracoabdominal ectopia cordis can undergo and survive full cardiac, neurologic, and abdominal repair during infancy. Furthermore we advocate different approaches determined by the severity of the presentation and the presence of other complicating factors.

Female↗
PubMed2000

Neutrophilic leucocytosis in a dog with a rectal tumour.

A nine-year-old cocker spaniel was presented with a three-year history of intermittent haematochezia and a palpable rectal mass. Routine haematological examination revealed a marked mature neutrophilia (86.04 x 10(9) neutrophils/litre). A friable mass in the middle portion of the rectum was detected on colonoscopy. Histopathological examination of mucosal pinch biopsies collected from the mass confirmed a diagnosis of adenomatous tubulopapillary polyp. Some evidence of malignant transformation was observed. Palliative treatment with piroxicam suppositories at a dose of 1.4 mg/kg administered rectally every third day was instituted. On re-evaluation, 47 days after starting medical therapy, the owner reported a significant reduction in haematochezia and tenesmus; however, frequency of defecation had remained unaltered. Routine haematology revealed a reduction in the mature neutrophil count (33.67 x 10(9) neutrophils/litre). This report describes a case of a rectal tumour associated with a neutrophilic leucocytosis, which responded to palliative therapy with piroxicam suppositories.

Adenoma↗
PubMed2000

Preliminary clinical observations on the use of piroxicam in the management of rectal tubulopapillary polyps.

Rectal tubulopapillary polyps were diagnosed in eight dogs following proctoscopy and mucosal pinch biopsy. Histological examination of the pinch biopsies revealed evidence of malignant transformation in three of the cases. The remaining cases were diagnosed as benign polyps. Inflammatory changes were observed in four cases. Seven dogs were treated with piroxicam suppositories and one with oral piroxicam. All dogs were re-examined after four to six weeks of piroxicam therapy and the extent of haematochezia, tenesmus and faecal mucus production was reduced in all cases. The owners of seven of the dogs considered the improvement in clinical signs to be good or excellent. Cases with and without evidence of inflammation responded equally well. This finding supports the hypothesis that piroxicam has an antineoplastic effect due to apoptosis and alteration in the cell cycle. Medical management with piroxicam may provide a non-invasive treatment option for dogs with rectal polyp formation in which surgical treatment is likely to be associated with complications such as incontinence, infection and wound breakdown, or where the owner declines such treatment.

Animals↗
PubMed2000

Idiopathic phenobarbital-responsive hypersialosis in the dog: an unusual form of limbic epilepsy?

Three unusual cases of salivary gland enlargement and hypersialosis in the dog that responded to anticonvulsant therapy are reported. Presenting complaints included weight loss, hypersalivation, retching and vomiting of several weeks' duration. Two dogs were presented with enlarged painful mandibular salivary glands. The third dog exhibited bizarre behaviour (including jaw chattering) and developed enlarged painful mandibular salivary glands during hospitalisation. Fine needle aspirate cytology and biopsies from the enlarged salivary glands revealed no significant pathological changes. In one dog, an electroencephalogram revealed changes consistent with epilepsy. Hypersialism and salivary gland enlargement resolved completely during phenobarbital administration in all cases. Two dogs were successfully weaned off treatment six months after diagnosis. The remaining dog relapsed after eight months, but normalised with the addition of oral potassium bromide. It is hypothesised that the syndrome idiopathic hypersialosis may in fact be an unusual form of limbic epilepsy.

Animals↗
PubMed1999

DNA transport by a micromachined Brownian ratchet device.

We have micromachined a silicon-chip device that transports DNA with a Brownian ratchet that rectifies the Brownian motion of microscopic particles. Transport properties for a DNA 50-mer agree with theoretical predictions, and the DNA diffusion constant agrees with previous experiments. This type of micromachine could provide a generic pump or separation component for DNA or other charged species as part of a microscale lab-on-a-chip. A device with reduced feature size could produce a size-based separation of DNA molecules, with applications including the detection of single-nucleotide polymorphisms.

DNA↗
PubMed1999

Gene expression analysis by transcript profiling coupled to a gene database query.

We describe an mRNA profiling technique for determining differential gene expression that utilizes, but does not require, prior knowledge of gene sequences. This method permits high-throughput reproducible detection of most expressed sequences with a sensitivity of greater than 1 part in 100,000. Gene identification by database query of a restriction endonuclease fingerprint, confirmed by competitive PCR using gene-specific oligonucleotides, facilitates gene discovery by minimizing isolation procedures. This process, called GeneCalling, was validated by analysis of the gene expression profiles of normal and hypertrophic rat hearts following in vivo pressure overload.

Animals↗
PubMed1999

Aetiology and diagnosis of persistent nasal disease in the dog: a retrospective study of 42 cases.

Forty-two dogs with a history of persistent nasal disease were evaluated by a combination of clinical examination, thoracic and nasal radiography, retroflexed endoscopy and biopsy, and anterograde rhinoscopy and blind nasal biopsy. A definitive diagnosis was made in 91 per cent of cases. Neoplasia was the most common diagnosis (33 per cent of cases), followed by inflammatory rhinitis (24 per cent). Other diagnoses included periodontal disease (10 per cent), aspergillosis (7 per cent) and foreign bodies (7 per cent). Adenocarcinoma was the most common tumour diagnosed. The clinical findings were found to be too variable to be used as specific diagnostic criteria. Anterograde rhinoscopy and retroflexed endoscopy had higher specificity and sensitivity than radiology for the diagnosis of neoplasia, inflammatory rhinitis, aspergillosis and foreign bodies. With a systematic approach to the investigation of persistent nasal disease, a definitive diagnosis can be successfully obtained in the vast majority of cases.

Adenocarcinoma↗
PubMed1998

Diet and large intestinal disease in dogs and cats.

Large intestinal disease, and more especially colitis, is a commonly seen problem in small animal practice. Although colitis is most frequently diagnosed in dogs, it is becoming increasing common in cats. The etiology of colitis is not known, but there is general agreement that an immune-mediated response to luminal antigen is involved. In particular, parasites, bacteria and dietary factors may be involved. In approximately 10% of dogs presented with typical signs of colitis, no pathologic lesion will be found on investigation. These dogs have a functional diarrhea associated with some stress factor and are thought to have irritable bowel syndrome (IBS). This condition is most frequently observed in working dogs, although highly nervous and excitable dogs may also exhibit similar clinical signs. Until the underlying etiology of colitis is determined, treatment regimens will remain symptomatic. Recent studies have placed considerable importance on the value of diet in the prevention, immediate and long-term therapy of colitis in dogs and cats. In particular the value of "novel" protein diets, fermentable fiber and polyunsaturated fatty acids is receiving the most attention. It is now possible to maintain patients in long-term remission and to modify the severity and chronicity of colitis by using diet alone. This paper will review the subject of dietary management of colitis and IBS and present results from the author's clinical research program.

Animals↗
PubMed1996

Megaoesophagus secondary to acquired myasthenia gravis.

Fifteen dogs with confirmed adult onset idiopathic megaoesophagus, in which no generalised muscle weakness was observed, were tested for the presence of acetylcholine receptor antibodies. Of these, six were found to have values greater than 0.6 nmol/litre, previously determined to be diagnostic of acquired myasthenia gravis. The mean serum titre value for these dogs was 5.59 nmol/litre (range 0.78 to 8.72 nmol/litre). It appears that a significant proportion of dogs presenting with megaoesophagus have myasthenia gravis and, if a prompt diagnosis and appropriate treatment can be instituted, clinical signs may improve.

Animals↗
PubMed1992

Fat absorption in dogs with demodicosis or zinc-responsive dermatosis.

Quantitative absorption of long-chain triglycerides was studied in normal dogs, dogs with demodicosis and dogs which had been successfully treated for zinc-responsive dermatosis. The mean serum triglyceride concentration of dogs treated for zinc-responsive dermatosis was significantly lower than that of normal dogs before (P less than 0.01) and at one hour (P less than 0.01) and two, three and four hours (P less than 0.001) after feeding vegetable oil. No significant difference was detected in the mean serum triglyceride concentration of dogs with demodicosis and normal dogs at any of the sampling times.

Absorption↗
PubMed1991

Cardiovascular risk factors in Hispanic, white, and black children: the Brooks County and Bogalusa Heart studies.

Cardiovascular disease risk factors were studied in Hispanic children in Brooks County, Texas, and in white and black children in Bogalusa, Louisiana, in 1984-1985. The same protocols were used at both sites; examiners in Brooks County were trained by Bogalusa Heart Study staff. All blood samples were analyzed in a single laboratory standardized by the Centers for Disease Control. Hispanic children were about 4 cm shorter and were about the same weight as white and black children. Subscapular skinfolds were thickest in Hispanic children. Little difference was noted for blood pressure levels in the three ethnic groups. Total cholesterol levels were highest in black children, with a drop during puberty being noted in all of the ethnic groups. This drop with puberty appeared somewhat earlier in the Hispanic children. Lipoprotein levels for Hispanic children were, in general, similar to those noted for white children. Some of the Hispanic-black differences in lipid and lipoprotein levels could be explained by differences in body size. Because Hispanics are at increased risk for specific diseases, such as diabetes, increased study of this population is warranted. Intervention and education programs aimed at altering this risk must address the unique cultural heritage of this population.

Adolescent↗