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D J Waters

Publications and source records attributed to D J Waters.

88 records · Page 5Linked to original sources
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The detection of pulmonary metastases by helical CT: a clinicopathologic study in dogs.

PURPOSE: We sought to determine the accuracy of helical CT in the detection of pulmonary metastases. METHOD: Four anesthetized dogs with metastatic osteosarcoma underwent helical CT with a collimation of 5 mm, a pitch of 2, and a reconstruction interval of 5 mm. All macroscopically evident metastases were recorded at autopsy. CT images were independently reviewed by 10 radiologists and compared with pathologic results. Alternate slices in the dog with the most metastases were microscopically examined in their entirety. RESULTS: Pathologic examination of the lungs revealed 132 macroscopically evident pulmonary metastases, of which 74 (56%) were detected by at least one reader. Forty-four of the 99 (44%) metastases of < or = 5 mm in diameter were detected by at least one reader compared with 30 of 33 (91%) metastases of > 5 mm in diameter (p < 0.0001). The 10 readers reported a total of 107 false positives. Complete microscopy of alternate slices in the dog with the most metastases (n = 68) revealed an additional 38 micrometastases of < or = 3 mm in diameter. None of the 32 micrometastases of < or = 1 mm were detected by CT. CONCLUSION: Helical CT has some limitations in the detection of pulmonary metastases.

Animals↗
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Effect of tamoxifen citrate on canine immobilization (disuse) osteoporosis.

The effect of tamoxifen citrate on bone mass in immobilization osteoporosis was studied in 11 growing dogs. Immobilization osteoporosis was induced by fiberglass cast immobilization of the right hindlimb for 28 days, while the left hindlimb served as a nonimmobilized control. Six dogs received tamoxifen citrate (1.5 mg/kg per os) once daily for 28 days; five dogs received no treatment. All dogs were euthanatized on day 28 and bone samples were collected. Bone mineral content of the distal tibial metaphysis of casted and uncasted limbs was measured by single photon absorptiometry. Immobilization resulted in a significant reduction in bone mass in the casted limb of untreated and tamoxifen-treated dogs. However, tamoxifen-treated dogs had less severe immobilization osteoporosis than untreated dogs. The calculated bone mass sparing effect of tamoxifen was 24.4%. Because of the complexity of pathologic bone remodeling, use of a single therapeutic agent may not be the optimal means of preventing bone loss associated with immobilization.

Animals↗
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A retrospective study of inguinal hernia in 35 dogs.

Inguinal hernia was associated with trauma in five dogs and was considered nontraumatic in 30 dogs. There were 11 males, 13 intact females, and six spayed females with nontraumatic inguinal hernia. Six dogs had bilateral hernias. Five dogs were younger than 4 months at the time of diagnosis. In 11 older dogs with nontraumatic inguinal hernia, the hernias were identified less than 7 days before surgical repair; in 14 older dogs, the hernias had been recognized for 1 to 60 months. Clinical signs in dogs without small intestinal incarceration were usually limited to a visible or palpable mass without pain or systemic illness. Herniorrhaphy approaches included inguinal, midline with contralateral ring evaluation, and celiotomy with or without inguinal exposure. Fat and omentum were the most common hernial contents. Small intestine was within the hernias of 12 dogs. Six dogs had nonviable small intestine. Postoperative complications included two incisional infections, one incisional dehiscence, two cases of peritonitis and sepsis associated with bowel leakage after intestinal resection and anastomosis, and one hernia recurrence. The overall prevalence of postoperative complications was 17%, and the mortality rate was 3%. Vomiting for 2 to 6 days was predictive of nonviable small intestine. Dogs younger than 2 years were at 11 times greater risk for nonviable small intestine than dogs older than 2 years. Four of five dogs with nontraumatic inguinal hernia and nonviable small intestine were intact males, whereas none of 13 intact females were affected. Only one of 14 dogs with longstanding hernias had nonviable small intestine.

Animals↗
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Reoperative neurosurgery in dogs with thoracolumbar disc disease.

OBJECTIVE: To characterize the subset of dogs in our neurosurgical practice that underwent spinal surgery for thoracolumbar (TL) disc herniation and subsequently underwent additional decompressive TL surgery. STUDY DESIGN: A retrospective case series. SAMPLE POPULATION: Thirty dogs that underwent reoperation for TL disc herniation. A comparison group of Dachshunds that underwent only one decompressive TL disc surgery was also studied. METHODS: Dogs that underwent reoperation were divided into two groups based on the interval between their first and second surgery. The early reoperation group included those dogs having a second surgery less than 4 weeks after the initial operation. The late reoperation group included those dogs having a second surgery more than 4 weeks after the initial operation. For each Dachshund in the late reoperation group, two Dachshunds that underwent only one decompressive TL disc surgery were selected and formed the comparison group. Dogs in the comparison group were matched with reoperated cases based on the severity of preoperative neurologic deficit and site of disc herniation. These two groups were compared to determine: (1) if age and body weight were risk factors for reoperation, and (2) if dogs had a poorer functional outcome after their second decompressive surgery than did those in the comparison group after their first (and only) decompressive surgery. RESULTS: A total of 30 of 467 (6.4%) dogs that underwent decompressive TL disc surgery were reoperated. In the early reoperative cases (n = 5 dogs), the inciting cause in all cases was residual compression from disc material at the site of the initial surgery. In the late reoperation group, 22 of 25 (88%) cases had a second disc herniation at a site distinct from the initial lesion. Dachshunds had a significantly higher risk for late reoperation (odds ratio and 95% CI = 3.67, 1.46 to 10.03); other small and medium-sized breeds (<20 kg) were underrepresented. Age and body weight were not significant predictors for reoperation. A total of 21 of 23 (91%) dogs had functional recovery after late reoperation. Complete sensorimotor loss was a significant negative predictor of functional recovery in the late reoperative cases (P = .01). Likelihood of functional recovery in dogs after their second decompressive surgery was identical to the functional recovery of dogs in the comparison group. CONCLUSIONS AND CLINICAL RELEVANCE: Our results show that a second disc herniation occurring at a site distinct from the initial lesion is the most common cause for reoperation and that Dachshunds have a significantly greater risk than other breeds.

Animals↗
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Intracranial lesions in dogs with hemangiosarcoma.

A retrospective analysis of 85 dogs with hemangiosarcoma (HSA) that underwent complete necropsy, including gross examination of the brain, was conducted. Grossly identifiable intracranial lesions were present in 17 dogs. Twelve of 85 dogs (14.2%) had brain metastases. Four of 85 dogs (4.7%) had hemorrhagic lesions and/or ischemic necrosis without identifiable tumor. One dog had a primary central nervous system tumor. Signs of intracranial disease were present in six of 85 dogs (7.1%) with HSA; four had brain metastases and two had nonneoplastic lesions. Metastases had a propensity for cerebrum and gray matter. Dogs with brain metastases had more widely disseminated disease than dogs without brain metastases (P less than 0.001). Dogs with pulmonary metastases were at greater risk for developing brain metastases than dogs without pulmonary metastases (odds ratio = 8.31). Although thoracic radiography accurately identified ten of 12 dogs (83%) with pulmonary metastases, too few cases were available to assess the applicability/accuracy of thoracic radiography in predicting the presence or absence of brain metastases in dogs with malignancy and signs of intracranial disease.

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Intramedullary spinal cord metastasis in the dog.

Intramedullary spinal cord metastasis (ISCM) was diagnosed in three dogs with signs of myelopathy. The clinicopathologic features of ISCM in these and previously reported cases in the veterinary and human literature were compared. Myelopathic signs associated with ISCM may be the initial clinical manifestation of malignancy or may develop in the patient with known malignancy. Pain, a frequent manifestation of extradural compressive myelopathy, is not a consistent feature of ISCM. Survey spinal radiographs are usually unrewarding and cerebrospinal fluid (CSF) abnormalities nonspecific. Myelography is indicated to differentiate intramedullary lesions from more common extradural compressive lesions. Myelographic interpretation may be difficult, and intramedullary tumors must be differentiated from spinal cord edema or hemorrhage. Evidence of widely disseminated malignancy should increase suspicion for ISCM; hemangiosarcoma and lymphosarcoma should be considered the most likely histologic types. CSF cytology may be helpful in the diagnosis of patients with lymphosarcoma. Prognosis is poor due to the frequent presence of disseminated disease, although temporary response to corticosteroid therapy may be achieved. More aggressive therapeutic approaches, such as spinal irradiation and microsurgical resection of metastases, have been advocated in humans but have not been reported in the dog. Although it is an uncommon complication of systemic malignancy, ISCM should be considered in the differential diagnosis of myelopathy in the dog.

Animals↗
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High urine concentrations of basic fibroblast growth factor in dogs with bladder cancer.

Because dogs with bladder cancer often have advanced disease at the time of diagnosis, the identification and use of a tumor marker that could facilitate earlier diagnosis is a valid approach to improve prognosis. The objective of this study was to determine if urine concentrations of the proangiogenic peptide, basic fibroblast growth factor (bFGF), are high in dogs with bladder cancer compared with normal dogs and dogs with urinary tract infection. We used a commercially available enzyme-linked immunosorbent assay test kit to quantitate bFGF in the urine of 17 normal dogs, 10 dogs with urinary tract infection, and 7 dogs with locally active transitional cell carcinoma of the urinary bladder. In normal dogs, the median urine bFGF concentration was 2.23 ng/g creatinine (quartile range, 1.53 to 5.12 ng/g creatinine). The median urine bFGF concentration in dogs with urinary tract infection did not differ significantly from normal dogs. Dogs with bladder cancer had significantly higher urine bFGF concentrations than normal dogs (P < .002) and dogs with infection (P < .02). The median urine bFGF concentration in dogs with transitional cell carcinoma was 9.86 ng/g creatinine (quartile range, 7.40 to 21.63 ng/g creatinine). Six of 7 dogs with bladder cancer had urine bFGF concentrations that were up to 7.4 times the 90th percentile value for normal dogs. Only 1 of 10 dogs with infection had a urine bFGF concentration that exceeded the 90th percentile of normal. These data suggest that canine bladder cancers export bFGF, and that urine bFGF may be useful as a diagnostic tumor marker or noninvasive indicator of treatment response.

Animals↗
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Skeletal metastasis as the initial clinical manifestation of metastatic carcinoma in 19 dogs.

Although the skeleton represents a potentially important target for the metastatic spread of carcinoma, the clinicopathologic features of skeletal metastases in dogs have not been documented extensively. In particular, no reports have focused on dogs in which skeletal metastasis was the initial clinical manifestation of their malignancy. Medical records were reviewed for dogs with skeletal carcinoma and cases were subdivided into 2 groups based upon the temporal relationship between the diagnosis of carcinoma and recognition of skeletal metastases. In 19 of 24 (79%) dogs, skeletal metastasis was the initial clinical manifestation of malignancy, and these dogs were studied in detail. Most affected dogs were elderly and weighted less than 25 kg. Thirty-six skeletal lesions were identified in 19 dogs. Skeletal metastases occurred most frequently in the axial skeleton and proximal long bones. Only 4 of 36 (11%) skeletal carcinomas occurred distal to the elbow or stifle. Mammary gland, prostate, and urinary bladder were the most common primary sites. In 11 of 19 (58%), dogs, the primary tumor could not be determined, and in 6 of these dogs, the primary tumor could not be identified despite complete postmortem evaluation. Physical examination and abdominal ultrasonography were most valuable in detecting the primary tumor. Although biopsy or fine-needle aspirate of skeletal lesions was essential in the diagnosis of skeletal carcinoma, these procedures did not yield definitive information on the primary tumor site. This report documents that the majority of skeletal metastases are diagnosed in dogs without a previous diagnosis of carcinoma. Detection of the primary tumor in these cases may be challenging, and skeletal metastases are frequently attributable to carcinoma of unknown origin.

Age Factors↗
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Skeletal neoplasms of small dogs: a retrospective study and literature review.

The skeletal neoplasms of small dogs are characterized poorly. In this retrospective study, the bone tumors of 37 small dogs (with body weights less than 15 kg), 74 large dogs (with body weights greater than 25 kg), and 134 small dogs previously reported in the literature were compared. Metastases accounted for about 25% of the bone tumors in small dogs, but less than 5% of the bone tumors in large dogs. In small dogs, osteosarcomas represented less than 50% of all skeletal neoplasms, frequently affected the axial skeleton, and had no apparent predilection for the distal radius. In this series and in the literature, fewer than 10 small dogs with appendicular osteosarcoma were treated with curative intent. Clinicians should use caution when extrapolating information on the biological behavior of osteosarcoma from large- and giant-breed dogs to small dogs.

Adenocarcinoma↗
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Skeletal metastasis in feline mammary carcinoma: case report and literature review.

Despite the highly malignant nature of feline mammary carcinoma, few cases of skeletal metastasis have been reported. In this paper, a case of feline mammary carcinoma with skeletal metastasis to a distal limb is presented. The pertinent literature on feline mammary carcinoma and bone metastases is reviewed. Although the metastases of carcinomas in dogs and humans usually exhibit a proximal skeletal distribution, cats are more likely to develop distal extremity lesions. Clinicians need to have an index of suspicion that skeletal metastases may be responsible for lameness in elderly cats. Further investigation of the comparative aspects of bone metastases in cats and other species may elucidate the factors that regulate the development of skeletal metastases.

Adenocarcinoma↗
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Cervical vertebral fractures in 56 dogs: a retrospective study.

The clinicopathological features of cervical fractures in 56 dogs were reviewed. "Hit by car" (HBC) was the most common inciting cause, and the axis and atlas were the vertebrae most frequently affected. Surgical treatment was associated with high (36%) perioperative mortality. However, all dogs that survived the perioperative period achieved functional recovery. Functional recovery was achieved in 25 (89%) of 28 nonsurgically treated dogs with adequate follow-up. Overall, severity of neurological deficits (nonambulatory status) and prolonged interval (five days or longer) from trauma to referral were associated with poorer outcome. Nonsurgical treatment is a viable therapeutic approach for many dogs with cervical fractures. Early neck immobilization and prompt referral are recommended, because delay in referral decreases the likelihood of functional recovery.

Accidents, Traffic↗
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Functional outcome in dogs after surgical treatment of caudal lumbar intervertebral disk herniation.

Caudal lumbar disk herniations (i.e., third lumbar [L3] to seventh lumbar [L7] intervertebral spaces) represent approximately 15% of surgically treated thoracolumbar disk herniations in dogs. A retrospective case-control study was conducted to determine the postoperative outcome of this subset of dogs in the authors' neurosurgical practice. Medical records (1985 through 1996) were reviewed for dogs with caudal lumbar disk herniation confirmed at surgery. Thirty-six cases were identified. For each case, two dogs that underwent surgical treatment for upper motor neuron thoracolumbar disk herniation (tenth thoracic [T10] to L3 intervertebral spaces) were selected as controls. Probabilities of functional recovery for cases and controls were 81% and 85%, respectively (p value of 0.49). In dogs with caudal lumbar disk herniation, complete sensorimotor loss was the only significant predictor of functional recovery (p value of 0.005). Disk herniations that occur at the thoracolumbar junction and those that occur in the caudal lumbar region should not be considered to be different in terms of surgical treatment and postoperative outcome. The lower motor neuron signs that often accompany caudal lumbar disk herniation reflect the site of spinal cord injury and do not necessarily predict a poor prognosis.

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Fibrocartilaginous embolic myelopathy in miniature schnauzers.

In large- and giant-breed dogs, fibrocartilaginous embolic myelopathy (FCEM) is a well-recognized syndrome of acute spinal cord infarction caused by embolization of fibrocartilage. The miniature schnauzer is reportedly the most frequently affected small breed, although clinical data from only six miniature schnauzers with FCEM is available in the literature. The purposes of this study were to determine the relative frequency of FCEM compared to other causes of myelopathy in miniature schnauzers, to characterize the clinicopathological features of FCEM in 38 miniature schnauzers, and to directly compare FCEM and intervertebral disk herniation in miniature schnauzers with respect to age at diagnosis; gender; neuroanatomical localization; and progression, asymmetry, and severity of neurological deficits. Fibrocartilaginous embolic myelopathy was the most common cause of myelopathy in miniature schnauzers. Age at diagnosis, asymmetry and severity of neurological deficits, and lack of progression of clinical signs after 24 hours assisted in distinguishing FCEM from intervertebral disk herniation. Fibrocartilaginous embolic myelopathy-related mortality in miniature schnauzers was significantly lower than mortality rates reported for affected large and giant breeds. Only 22% of miniature schnauzers were euthanized because of their disease, although the vast majority of survivors failed to achieve complete neurological recovery.

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Oncogene signal transduction inhibitors from medicinal plants.

Signal transduction is believed to be altered by cellular oncogenes or tumor suppressor genes during the transformation of normal cells into malignant cells. This proposition offers an attractive target for oncogene-based anticancer drug discovery from natural sources. Protein kinases encoded or modulated by oncogenes were used to prescreen the potential antitumor activity of medicinal plants. Protein-tyrosine kinase-directed fractionation and separation of the crude extracts of Polygonum cuspidatum and Koelreuteria henryi have led to the isolation of three different classes of protein-tyrosine kinase inhibitors, anthraquinone, stilbene and flavonoid. The anthraquinone inhibitor, emodin, displayed highly selective activities against src-Her-2/neu and ras-oncogenes.

Anthraquinones↗
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The canine prostate is a spontaneous model of intraepithelial neoplasia and prostate cancer progression.

Increasing evidence suggests that high grade prostatic intraepithelial neoplasia (PIN) represents a precancerous stage in the morphologic continuum of progression from benign epithelium to carcinoma. In this report, we summarize our work characterizing the high grade PIN that occurs spontaneously in the canine prostate. The similarity between canine and human PIN for basal cell layer disruption, proliferative index, microvessel density, and its association with carcinoma suggest that the canine prostate may be a useful model for studying carcinogenesis and cancer progression.

Aging↗