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Biomedical subjects

R C Straw

Publications and source records attributed to R C Straw.

At least 37 records · Page 2Linked to original sources
PubMed1991

Prevalence of nephrotoxicosis associated with a short-term saline solution diuresis protocol for the administration of cisplatin to dogs with malignant tumors: 61 cases (1987-1989).

The study reported here was undertaken to determine the nephrotoxicosis associated with the administration of cisplatin, an antineoplastic agent, to dogs when administered during 6-hour saline solution diuresis. Cisplatin (70 mg/m2 of body surface, IV, every 21 days) was given to 61 dogs with malignant neoplasia with a total of 185 doses in 1 (n = 9 dogs), 2 (n = 26 dogs), 3 (n = 4 dogs), 4 (n = 9 dogs), 5 (n = 2 dogs), and 6 (n = 11 dogs) treatments. The cisplatin was given over a 20-minute period after 0.9% NaCl solution (saline solution) was administered IV for 4 hours at a rate of 18.3 ml/kg of body weight/h. After the cisplatin infusion, saline solution diuresis was continued at the same rate for 2 hours. Before each treatment with cisplatin, dogs were evaluated with at least a physical examination, CBC, determination of serum urea nitrogen concentration, and in most cases, determination of serum creatinine concentration and urine specific gravity. Four of the 61 dogs (6.6%) developed clinically evident renal disease after 2 (1 dog), 3 (2 dogs), and 4 (1 dog) doses of cisplatin were administered. Three of the 4 dogs had preexisting disease of the urinary tract prior to the start of treatment. The survival time in dogs that developed renal disease (median, 145 days; range, 15 to 150 days) was similar to that of all dogs in this study (median, 154 days; range, 30 to 500 days), with 13 dogs still alive at the conclusion of the study.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Toxicoses associated with administration of mitoxantrone to dogs with malignant tumors.

One hundred twenty-nine dogs with histologically confirmed malignant tumors were used in a prospective study to determine the toxicity of the new dihydroxyquinone derivative of anthracene, mitoxantrone, which was administered IV at 21-day intervals at dosages ranging from 2.5 to 5 mg/m2 body surface area. Each dog was evaluated for signs of toxicosis for 3 weeks after each dose was administered or until the dog died, whichever came first. The number of dogs in each evaluation period were as follows: 1 dose (n = 129), 2 doses (n = 82), 3 doses (n = 43), 4 doses (n = 26), 5 doses (n = 19), 6 doses (n = 9), 7 doses (n = 6), 8 doses (n = 5), 9 doses (n = 3), and 10 doses (n = 1). The most common signs of toxicosis were vomiting, diarrhea, anorexia, and sepsis secondary to myelosuppression. None of the dogs died of complications resulting from mitoxantrone treatment. Dogs with signs of toxicosis during the 21-day interval from administration of the first dose of mitoxantrone were 95 times (P = 0.003) more likely to develop signs of toxicosis during the 21-day interval from the second dose of mitoxantrone. Similarly, dogs that developed signs of toxicosis during the 21-day interval from the administration of the second dose were 34 times (P less than 0.001) more likely to develop signs of toxicosis during the 21-day interval from the administration of the third dose. With each 1 mg/m2 increase in mitoxantrone, the odds of developing signs of toxicosis increased by 5.9 fold (P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Efficacy of mitoxantrone against various neoplasms in dogs.

One hundred twenty-six dogs with histologically confirmed, measurable malignant tumors were evaluated in a prospective study to determine the response to the antineoplastic drug mitoxantrone. Ninety-five dogs had been refractory to one or more treatment modalities (surgery, n = 57; chemotherapy other than mitoxantrone, n = 37; radiation, n = 4; whole body hyperthermia, n = 1). The extent of neoplastic disease was determined immediately before each dose of mitoxantrone was administered (1 to 10 doses, 2.5 to 5 mg/m2 of body surface area, IV) 21 days apart. Each dog was treated with mitoxantrone until the dog developed progressive disease or until the dog's quality of life diminished to an unacceptable level as determined by the owner or attending veterinarian. A partial or complete remission (greater than 50% volume reduction) was obtained in 23% (29/126) of all dogs treated. Tumors in which there was a partial or complete remission included lymphoma (11/32), squamous cell carcinoma (4/9), fibrosarcoma (2/9), thyroid carcinoma (1/10), transitional cell carcinoma (1/6), mammary adenocarcinoma (1/6), hepatocellular carcinoma (1/4), renal adenocarcinoma (1/1), rectal carcinoma (1/1), chondrosarcoma (1/2), oral malignant melanoma (1/12), cutaneous malignant melanoma (1/1), myxosarcoma (1/1), mesothelioma (1/1), and hemangiopericytoma (1/1). Our results indicated that mitoxantrone induces measurable regression in various malignant tumors in dogs.

Animals↗
PubMed1991

Percent tumor necrosis as a predictor of treatment response in canine osteosarcoma.

The percent tumor necrosis was determined in 200 dogs with spontaneously occurring osteosarcoma. One hundred dogs had no treatment before amputation or death. One hundred other dogs were treated with either radiation therapy alone (n = 23), intraarterial (IA) cisplatin alone (n = 16), intravenous (IV) cisplatin alone (n = 6), radiation therapy plus IA cisplatin (n = 47), or radiation therapy plus IV cisplatin (n = 8). Eighty-nine of these 100 dogs had their tumors resected 3 weeks after the end of therapy (6 weeks after the initiation of therapy) and replaced with a cortical bone allograft. Dogs with preoperative treatment were evaluated for local tumor control and time to metastasis. The mean percent tumor necrosis in untreated osteosarcoma was 26.8%. The mean percent tumor necrosis for dogs receiving radiation only, IA cisplatin only, and IV cisplatin only was 81.6%, 49.1% and 23.8%, respectively. The mean percent tumor necrosis for dogs receiving radiation therapy plus IA cisplatin or radiation therapy plus IV cisplatin was 83.7% and 78.2%, respectively. There was no significant difference between percent tumor necrosis in untreated osteosarcoma compared with those receiving IV cisplatin, but there was a significant increase in percent tumor necrosis with all other treatments. A mathematic model for the effect of cisplatin and radiation dose was developed using multiple regression analysis. The radiation dose calculated to cause at least 80% tumor necrosis was 42.2 Gy (95% confidence interval [CI], 38.0 to 47.6 Gy) when radiation was given alone and 28.1 Gy (95% CI, 21.3 to 36.6 Gy) when radiation was combined with IA cisplatin. Areas of viable tumor tended to be most frequent adjacent to the articular cartilage and in the joint capsule. Percent tumor necrosis was strongly predictive for local tumor control; 28 of 32 dogs with greater than 80% tumor necrosis had local control, and only eight of 29 dogs with less than 79% tumor necrosis had local control (P = 0.0047). There was no correlation between percent tumor necrosis and time to metastasis.

Animals↗
PubMed1991

Comparative aspects of osteosarcoma. Dog versus man.

Canine osteosarcoma bears striking resemblance to osteosarcoma in humans. Similarities include the following: male sex predilection, large patient size, 75% or more affecting the appendicular site, metaphyseal location, generally unknown etiology, less than 10% of patients have documented metastasis at presentation, over 90% of tumors show high-grade histology, 75% of tumors show aneuploidy, the metastatic rate is 80% or more with amputation alone, the lung is the most common site of metastasis, and there is improved survival with adjuvant chemotherapy. The major differences are age of onset, with dogs being affected in middle age; greater frequency in the dog, with over 8000 new cases per year; and time to metastasis being faster in the dog than man. Canine osteosarcoma is a readily available and highly comparable spontaneously occurring cancer that should be useful in a better understanding of the same disease in humans.

Age Factors↗
PubMed1990

Comparison of DNA aneuploidy of primary and metastatic spontaneous canine osteosarcomas.

Spontaneous canine osteosarcomas were analyzed for DNA aneuploidy and percentage of S phase cells using flow cytometry. Forty-eight dogs were studied in which both a primary tumor and subsequent metastases were available. The DNA index distributions for the primary tumors and the metastases were quite similar. However, when individual primary tumors and metastases derived from them were compared, many of the cases had different ploidy values. The tumor cells were also analyzed for percentage of S phase. The diploid metastases had less than 17% S phase cells, whereas the aneuploid metastases had up to 40% S phase cells. There was a direct correlation between the DNA index and the percentage of S phase in the metastases.

Aneuploidy↗
PubMed1990

Radiotherapy prior to cortical allograft limb sparing in dogs with osteosarcoma: a dose response assay.

Twenty-one dogs with spontaneously occurring appendicular osteosarcoma were given preoperative radiation therapy prior to a limb sparing procedure using a cortical allograft. Radiation doses were randomly assigned, ranged from 36-52 Gy in 4 Gy intervals, and were given in 10 equally-sized fractions on a M, W, F schedule. Seventeen of the 21 dogs underwent the limb sparing procedure approximately 3 weeks after completion of radiation therapy. Local tumor recurrence was documented in 4 of 17 dogs at mean and median times of 5.5 and 5.8 months, respectively, after initiation of radiation therapy. Three of 4 recurrences were in anatomic regions with sparse adjacent soft tissue which precluded wide excision. Complications were significant. Fixation device failure occurred in 9 of 17 dogs and was associated with host bone necrosis, muscle thinning and fibrosis of vessels and nerves in irradiated normal tissue. Incidence of host bone necrosis was directly related to radiation dose (Kendall's statistic, p = 0.005). Metastasis occurred in all 21 dogs. Mean and median times to metastasis in these dogs were 5.1 and 4.0 months, respectively, after initiation of radiation therapy. Local tumor control rates and survival times were higher in dogs developing allograft infection suggesting that infection acted as an immunostimulant. All local failures occurred in dogs that did not develop allograft infection and median survival times for uninfected versus infected dogs were 5 and 11 months, respectively (logrank test, p = 0.029). Increased tumor radiopacity following radiation therapy was significantly related to survival. Median survival in dogs whose tumors were characterized by decreased, unchanged or increased opacity after radiation therapy were 3.5 and 14 months, respectively (logrank test, p = 0.014). Based on the results of our study, radiation therapy can not be recommended as part of limb sparing treatments for patients with osteosarcoma at doses and dose per fraction values similar to those used herein.

Animals↗
PubMed1990

Management of canine appendicular osteosarcoma.

Canine appendicular osteosarcoma is a highly malignant primary bone cancer that closely resembles the same disease in humans. Although amputation alone usually controls local disease, metastatic cancer is common and is the cause of death or euthanasia in 90% of dogs by 1 year. Cisplatin (+/- doxorubicin) chemotherapy appears to improve survival time in dogs; however, metastatic cancer remains a problem. Pulmonary metastasectomy may prolong survival in carefully selected dogs. Limb-sparing, although involved and potentially fraught with complications, can result in local disease control and a functional, pain-free limb in selected dogs without adversely affecting their survival. Studies are ongoing to improve local disease control with limb-sparing and improve disease-free survival in dogs with appendicular osteosarcoma. In conclusion, dogs with osteosarcoma were previously thought to have a hopeless prognosis, but the outlook is beginning to appear more optimistic. Limb-sparing in dogs is still evolving; however, it is possible in selected cases to optimize survival and preserve limb function.

Animals↗
PubMed1989

Limb-sparing treatment for osteosarcoma in dogs.

Twenty dogs with spontaneously developing osteosarcoma of the extremities were treated with 1 of 3 multimodality limb-sparing procedures. Excision of the tumor was preceded by intra-arterial (IA) administration of cisplatin (cis-diamminedichloroplatinum) alone directed to the affected extremity, irradiation plus IA administration of cisplatin, or irradiation plus IV administration of cisplatin. All dogs were free of apparent metastatic disease at the time of initial treatment. After diagnosis, dogs administered cisplatin IA had selective angiography performed on arteries supplying the tumor, and 70 mg of cisplatin/m2 of body surface was administered over 2 hours. This protocol was repeated 3 weeks later. Dogs that were irradiated received 25 or 40 Gy in 10 fractions over a 22-day period. The first and last radiation doses were immediately preceded by IA administration of cisplatin. Dogs given IV treatment received 10 mg of cisplatin/m2 2 hours before each radiation fraction was administered. Three weeks after the last treatment, tumors were excised and the limb underwent orthopedic reconstruction, generally using cortical allografting and bone plating. Limb function, allograft healing, local tumor control, and metastatic dissemination were monitored. Limb function was good to excellent in 69% (11/16) of dogs evaluated. Forelimb-sparing procedures were generally associated with better function than were limb-sparing procedures performed on hind limbs. Local tumor control was obtained in 79% (11/14) of dogs thoroughly evaluated, with local recurrences in 3 dogs at 3, 4, and 7 months after treatment. Fifteen dogs developed metastatic disease at a median time of 8 months from the time of diagnosis. Mean and median survival times for all dogs, regardless of cause of death, were 11.7 and 8 months, respectively. Tumor necrosis greater than 80% was statistically associated with lack of recurrence. Of 16 dogs, 5 (31%) developed infections at the surgical site. Multimodality limb-sparing treatment is believed to be a viable alternative for appropriately selected dogs with osteosarcoma. The optimal method of treatment prior to or after tumor excision has not yet been established.

Angiography↗
PubMed1989

Multilobular osteochondrosarcoma of the canine skull: 16 cases (1978-1988).

The medical records of 12 dogs with multilobular osteochondrosarcoma (MLO) and examined at the Veterinary Teaching Hospital, Colorado State University from August 1979 to January 1987 were reviewed. Medical records of 1 dog with MLO and 3 dogs with MLO examined at the Ontario Veterinary College, University of Guelph and the Veterinary Medical Teaching Hospital, University of California, Davis, respectively, were also reviewed and included in the study. The mean age of affected dogs was 7.5 years, a single breed did not appear to be overrepresented, and males were affected as frequently as were females. All of the primary lesions affected either the mandible, maxilla, or cranium. Excision was the only treatment in 11 dogs, 2 dogs had radiotherapy in addition to excision, and 1 dog had radiotherapy and chemotherapy after excision. Twelve treated dogs had follow-up information available. Of the 12 treated dogs, 7 (58%) had local recurrence, with median time to recurrence of 14 months. Seven dogs (58%) developed metastatic disease after treatment, with median time to metastasis of 14 months. The median disease-free interval was 12 months, and the median survival time was 21 months. Excision with histologically complete surgical margins appeared to offer good opportunity for long-term tumor control. The role of adjuvant chemotherapy and radiotherapy in the management of MLO remains unclear.

Animals↗
PubMed1988

Jamshidi needle biopsy for diagnosis of bone lesions in small animals.

Sixty-two bone lesions in 59 small animals were biopsied using a Jamshidi-type biopsy needle. In all instances, the Jamshidi needle biopsy diagnosis was confirmed or disputed by results of histologic examination of specimens obtained by surgical resection or by amputation or at necropsy. In 57 of 62 bone lesions, biopsy resulted in an accurate diagnosis of tumor vs nontumor, yielding an accuracy rate of 91.9%. The specific tumor type or lesion type was identified accurately by Jamshidi needle biopsy in 51 of 62 lesions, yielding an accuracy of 82.3%. Of the 62 bone lesions, 48 were intramedullary osteosarcoma and 62.5% of these were subclassified correctly by Jamshidi needle biopsy results as osteoblastic, chondroblastic, fibroblastic, osteoclastic, or poorly differentiated osteosarcoma. Jamshidi needle biopsy was easy, quick, and safe, and its high accuracy rate of diagnosis indicated that it should be a valuable aid for diagnosis of bone lesions in small animals.

Animals↗
PubMed1986

Use of radiotherapy for the treatment of intranasal tumors in cats: six cases (1980-1985).

Six cats with intranasal neoplasia treated with radiotherapy were evaluated. The mean survival time from the initiation of radiotherapy was 19 months, with 2 cats still known to be alive. Two cats died for reasons unrelated to the primary tumor. One cat had no clinical evidence of nasal tumor 41 months after treatment, but was lost to further follow-up evaluation.

Adenocarcinoma↗
PubMed1985

Idiopathic hematuria of unilateral renal origin in a dog.

Idiopathic hematuria of unilateral renal origin was diagnosed in a 3-month-old male Weimaraner. The hematuria had been visible grossly for 6 weeks. Extensive clinicopathologic, radiographic, and histologic evaluations localized the source of the hematuria to the right kidney, but could not identify a cause. Nephrectomy of the right kidney resolved the problem. This case report supports a previous article comparing canine idiopathic hematuria of renal origin with benign essential hematuria of human beings.

Animals↗
PubMed1985

Transposition of the great arteries in a cat.

Transposition of the great arteries, a congenital cardiac disorder, was diagnosed in a 4-month-old domestic short-haired kitten. Angiography revealed a patent ductus arteriosis, with the pulmonary artery originating from the left ventricle and the aorta originating from the right ventricle. Blood gas analysis suggested a high ventricular septal defect. Necropsy confirmed the diagnosis.

Angiography↗