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Biomedical subjects

S L Marks

Publications and source records attributed to S L Marks.

48 records · Page 3Linked to original sources
PubMed1992

Surgical treatments for intervertebral disc disease.

Surgical treatments for intervertebral disc disease are useful for animals with gradually progressive, severely acute, or recurrent lesions. Surgical patients require a diligent neuroradiographic evaluation to confirm location and severity of the discopathy and rule out conditions unrelated to disc disease. Although controversial, some surgeons advocate fenestration for recurrent pain or mild ataxia associated with a noncompressive lesion. Decompressive procedures are recommended for treatment and prognostication of compressive disc-associated myelopathy. Foraminotomy is reserved for patients with lateralizing extrusions confirmed with myelography or newer imaging modalities (CT, MRI). Future treatments for animals may include chemonucleolysis or various discectomy procedures currently performed in humans with symptomatic disc disease.

Animals↗
PubMed1991

DNA flow cytometric study of the hyperplastic and neoplastic canine prostate.

Flow cytometric DNA measurements were carried out on 45 formalin-fixed, paraffin-embedded canine prostate tissues. The tissues were categorized as normal, hyperplastic, or neoplastic on the basis of light microscopic examination, and DNA ploidy was compared with histologic classification. Ten normal prostate samples showed diploid DNA histograms, but with proliferation greater than that found in the normal human prostate. Thirteen specimens of benign prostate hyperplasia showed diploid or near-diploid DNA histograms. Of 22 prostatic carcinomas, 12 were diploid and 10 were aneuploid, with the majority of the aneuploidy being near-triploid. The frequency of DNA aneuploidy recognized in canine prostatic carcinoma is similar to findings in human prostatic carcinoma if all their grades of malignancy are included.

Aneuploidy↗
PubMedDate not supplied

Quantitative videofluoroscopic evaluation of pharyngeal function in the dog.

Videofluoroscopic evaluation of both liquid barium and barium soaked kibble was performed in 11 adult, clinically normal dogs of varying breeds. Each examination was digitized and evaluated frame by frame to establish the normal timing sequence of the pharyngeal phase of swallowing. Closure of the epiglottis was considered the onset of swallowing. The time to each of the following events was recorded: (1) Maximum pharyngeal contraction, (2) Opening of the epiglottis, (3) Opening of the cranial esophageal sphincter, and (4) Closure of the cranial esophageal sphincter. These values were found to be consistent both intra and interpatient. Retrospective analysis of 3 videofluoroscopic examinations from dogs that met the subjective criteria defining cricopharyngeal achalasia was then performed. A statistically significant delay in the time to opening and closure of the cranial esophageal sphincter was found employing both liquid barium and barium soaked kibble in the dogs with cricopharyngeal achalasia.

Animals↗
PubMedDate not supplied

Nonsecretory multiple myeloma in a dog: immunohistologic and ultrastructural observations.

A 12-year-old, female spayed Chihuahua was diagnosed with nonsecretory multiple myeloma on the basis of multiple osteolytic lesions, histological evidence of plasma cell infiltrate on a bone biopsy, and absence of a monoclonal protein on serum and urine electrophoresis. A 6-week course of prednisone therapy resulted in no clinical improvement and the dog was euthanized 2 weeks after presentation because of progressive neurological impairment. Bone marrow specimens were processed and stained for ultrastructural and immunohistologic evaluation. Staining with antisera to immunoglobulin (Ig) G, IgM, and IgA was negative. Tumor cells in both the pelvic and rib masses displayed prominent reactivity with an antibody specific for a canine beta 1 integrin similar to VLA-4; however, the tumor cells failed to stain with antibodies known to react predominantly with antigens on B-lymphocytes (major histocompatibility complex class II, CD45RA, and CD21) or T-lymphocytes (Thy-1). The tumor cells also failed to stain with an antibody specific for the beta-subunit (CD18) of the leukocyte integrins (D11/CD18). Ultrastructural studies performed on bone marrow specimens revealed a pleomorphic population of plasma cells with moderate amounts of rough endoplasmic reticulum, erythrophagocytosis, and lack of crystalline inclusions.

Animals↗
PubMedDate not supplied

Pheochromocytoma in dogs: 61 cases (1984-1995).

This report presents the clinical, laboratory, imaging, and pathologic findings in 61 dogs with pheochromocytoma by retrospective evaluation of medical records. Pheochromocytomas were diagnosed by histopathologic examination of tissue specimens in all dogs. Special stains (chromogranin A and synaptophysin) also were used to confirm the chromaffin cell origin of the tumors. Epidemiologic findings were in agreement with previous studies, indicating that pheochromocytomas affect middle-aged to older dogs with no apparent gender or breed predilection. The tumor was considered clinical in 21 dogs (34%), was responsible for abnormalities related to a space-occupying mass in 7 dogs (11%), and was an incidental finding in 35 dogs (57%). The hematologic and biochemical findings were nonspecific. Hypertension was detected in 10 of 23 (43%) dogs tested, but all hypertensive dogs had concurrent diseases that may have contributed to hypertension. Abdominal ultrasonography was the most commonly used imaging procedure, with a mass detected in the region of the adrenal glands in 20 of 40 (50%) dogs examined. In 4 of the 20 dogs (20%), invasion of the caudal vena cava was identified. Surgery was performed in 17 dogs (28%) with immediate death or euthanasia of 5 dogs. Survival after surgery ranged from 1 day to 3.25 years. Pheochromocytomas were locally invasive in 39% of affected dogs and produced metastases in 13% of the cases. Common sites for metastases included regional lymph nodes, liver, lung, kidney, spleen, and bone. A high frequency of concurrent neoplasia (54%), including endocrine neoplasia, was identified.

Adrenal Gland Neoplasms↗
PubMedDate not supplied

Prevalence and identity of translocating bacteria in healthy dogs.

Bacterial translocation is characterized by the passage of intestinally derived bacteria across the intestinal mucosa to local or regional tissues. This phenomenon is believed to be important in the pathogenesis of gram-negative bacteremia and septicemia; however, the pathway or route of translocation remains unclear. To define the route of translocation better, mesenteric lymph nodes from 50 apparently healthy dogs undergoing elective ovariohysterectomies were cultured aerobically and anaerobically. The aims of this study were to determine the prevalence of bacterial translocation and to quantify and identify types of organisms found in mesenteric lymph nodes. Peripheral blood and portal blood samples were similarly cultured to rule out hematogenous organisms as a source of lymph node contamination. Bacteria were isolated from mesenteric lymph nodes of 26 dogs (52%). The number of bacteria varied from 50 to > 10(5) organisms/g of tissue. Bacteria isolated included Staphylococcus intermedius (n = 3), coagulase-negative Staphylococcus (n = 2), nonhemolytic Streptococcus (n = 4), Bacillus species (n = 5), Escherichia coli (n = 6), Salmonella species (n = 3), Pseudomonas species (n = 2), Enterococcus species (n = 2), Clostridium sordelli (n = 1), Micrococcus species (n = 1), Lactobacillus species (n = 1), and Propionibacterium acnes (n = 1). One of 50 peripheral blood samples yielded an unidentified gram-positive coccus and a coagulase-negative Staphylococcus. No bacteria were isolated from portal blood samples of any dog. Further studies of this type on sick dogs are warranted before clinical recommendations can be made to culture mesenteric lymph nodes routinely.

Animals↗
PubMedDate not supplied

Dietary vitamin D toxicity in a household of pot-bellied pigs (Sus scrofa).

Vitamin D intoxication developed in Vietnamese Pot-Bellied Pigs (Sus scrofa) fed 2 commercially available swine rations. Pronounced hypercalcemia and a history incompatible with other causes of hypercalcemia led to confirmation of this diagnosis by plasma vitamin D metabolite analysis in 2 affected animals as compared to a control animal. Feed sample analysis suggested the diet as the likely source of toxicity.

Animal Feed↗
PubMedDate not supplied

Evaluation of serum feline pancreatic lipase immunoreactivity and helical computed tomography versus conventional testing for the diagnosis of feline pancreatitis.

Serum feline trypsinogen-like immunoreactivity (fTLI) concentrations and abdominal ultrasound have facilitated the noninvasive diagnosis of pancreatitis in cats, but low sensitivities (33% and 20-35%, respectively) have been reported. A radioimmunoassay has been validated to measure feline pancreatic lipase immunoreactivity (fPLI), but the assay's sensitivity and specificity have not been established. In human beings, the sensitivity of computed tomography (CT) is high (75-90%), but in a study of 10 cats, only 2 had CT changes suggestive of pancreatitis. We prospectively evaluated these diagnostic tests in cats with and without pancreatitis. In all cats, serum was obtained for fTLI and fPLI concentrations, and pancreatic ultrasound images and biopsies were acquired. Serum fPLI concentrations (P< .0001) and ultrasound findings (P = .0073) were significantly different between healthy cats and cats with pancreatitis. Serum fTLI concentrations (P = .15) and CT measurements (P = .18) were not significantly different between the groups. The sensitivity of fTLI in cats with moderate to severe pancreatitis was 80%, and the specificity in healthy cats was 75%. Feline PLI concentrations were both sensitive in cats with moderate to severe pancreatitis (100%) and specific in the healthy cats (100%). Abdominal ultrasound was both sensitive in cats with moderate to severe pancreatitis (80%) and specific in healthy cats (88%). The high sensitivities of fPLI and abdominal ultrasound suggest that these tests should play an important role in the noninvasive diagnosis of feline pancreatitis. As suggested by a previous study, pancreatic CT is not a useful diagnostic test for feline pancreatitis.

Animals↗