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Biomedical subjects

R Walshaw

Publications and source records attributed to R Walshaw.

At least 37 records · Page 2Linked to original sources
PubMed1988

Thyroid and immunologic status of dogs with perianal fistula.

Lymphocyte-proliferation responses, absolute lymphocyte counts, and thyrotropin-stimulation responses were determined in 33 dogs with perianal fistula; serum immunoglobulin values also were determined in 15 of the 33 dogs. Lymphocytes were stimulated with concanavalin A, pokeweed mitogen, and phytohemagglutinin and were cultured with medium containing normal pooled canine serum or fresh patient's autologous serum. Initially, lymphocytes from 9 dogs (27.3%) had depressed stimulation responses to greater than or equal to 1 phytomitogen, and 4 of the 9 dogs had absolute lymphopenia. One month after recovery in these 9 dogs, lymphocytes from 4 dogs (66.7%) had normal proliferation responses. Of immunoglobulin determinations in 15 dogs, serum IgA values were 32 to 185 mg/dl (mean, 69 +/- 10 mg/dl) and were low in 2 dogs (13%), and serum IgM values were 48 to 610 mg/dl (mean, 263 to 46 mg/dl) and were high in 8 dogs (53%). Serum IgG values were 1,050 to 3,220 mg/dl (mean, 2,339 +/- 165 mg/dl) and were high in 10 dogs (71%). After thyrotropin stimulation, 1 dog was considered hypothyroid. Neither pathogenesis nor prognosis of canine perianal fistula was clarified via immunoglobulin concentrations or absolute lymphocyte counts. Based on lymphocyte-proliferation assays, suppression of cell-mediated immunity was probably a result of perianal fistula, rather than a cause of the fistula.

Animals↗
PubMed1987

Naproxen-induced toxicosis in a dog.

Naproxen, a nonsteroidal anti-inflammatory drug, induced gastric ulceration and bleeding in a dog. Clinical signs included vomiting, anemia, melena, and weakness. The dog responded to a blood transfusion and supportive treatment (lactated Ringer's solution with added K+ and B vitamins, an antacid, and cimetidine). Naproxen had been given to the dog by the owner, as treatment for shoulder stiffness.

Animals↗
PubMed1987

Radiotherapy of malignant nasal tumors in 67 dogs.

The nasal cavity of 67 dogs with malignant nasal neoplasia was treated with radiation. Preirradiation surgical cytoreduction of the tumor was done in 41 dogs. Fifty dogs were irradiated by use of 10 fractions over 22 days, and 17 dogs were given a similar total dose in 5 fractions over 35 days. The range of survival times (0.5 to 42 months), median survival time (8.5 months), and 1- and 2-year survival rates (38% and 30%, respectively) were better than those expected for other methods of treatment. Serious complications were few (4%). Survival times for dogs were determined on the basis of histologic tumor type and on the basis of megavoltage (cobalt or linear accelerator) vs softer deep radiation (cesium or orthovoltage) treatment, with or without cytoreductive surgery. Survival times of 10 dogs given softer radiation without surgery were shorter than those of 14 dogs that were given softer radiation and had cytoreductive surgery. Survival times of dogs that were given softer radiation and had surgery were similar to those of dogs that were given megavoltage radiation only. Cytoreductive surgery did not improve survival times for dogs that were given megavoltage radiation. Median survival time for 38 dogs with adenocarcinoma was 12 months, compared with 6 months for 14 dogs with squamous cell or undifferentiated carcinoma. Median survival time for 16 dogs with a variety of sarcomas was 11.2 months. Survival times of dogs with adenocarcinoma or sarcoma were significantly better (P less than 0.02 or 0.03) than for dogs with squamous cell or undifferentiated carcinoma. Necropsies were performed on 27 of 58 dogs that died or were euthanatized.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1987

Open peritoneal drainage for treatment of contaminated peritoneal cavity and septic peritonitis in dogs and cats: 24 cases (1980-1986).

The medical records of 22 dogs and 2 cats in which generalized peritonitis had been treated by open peritoneal drainage were reviewed. The age of the affected animals ranged from 5 months to 14 years. The causes of peritonitis were numerous, with the most common being leakage of gastrointestinal contents through spontaneous gastric or intestinal perforations and peritoneal contamination resulting from surgical complications. Bacteria were isolated from 18 (94.7%) of 19 specimens obtained for culturing at the time of diagnosis of peritonitis and from 8 (80%) of 10 specimens obtained for culturing at the time of final abdominal closure. Only 2 (25%) of 8 of the animals in which bacteria were isolated at the time of final abdominal closure died. The overall mortality was 33%. The mortality attributable to peritonitis or its direct complications was 21%. Open peritoneal drainage was tolerated well by all patients.

Animals↗
PubMed1986

Cyclosporine pharmacokinetics in normal and pancreatectomized dogs.

Oral and i.v. cyclosporine (Cs) pharmacokinetics determined from radioimmunoassay (RIA) data were compared in normal and pancreatectomized dogs. An altered pharmacokinetics of Cs was observed in the pancreatectomized dogs that include: a 170% larger central compartment volume; a 34% greater total-body clearance; and lower steady-state average serum concentrations relative to the normals. Even though there were marked intersubject variations, both groups displayed a triexponential decline in Cs serum concentrations and disposition kinetics. Following 7 daily oral doses of commercial cyclosporine (CsA) (20 mg/kg) the Cs serum trough concentrations of the pancreatectomized dogs were consistently below 100 ng/ml, while those of the normal dogs were above 400 ng/ml. No alteration of CsA oral absorption was noted following pancreatectomy. This study suggests that frequent serum Cs concentration monitoring, with appropriate dosage adjustments, even in normals, is necessary to assure adequate drug levels. More significantly, the CsA dosage for pancreatectomized dogs should be several times greater to maintain serum concentrations comparable to normal dogs.

Animals↗
PubMed1986

Transplantation of pancreatic islets in dogs.

Dispersed pancreatic islet tissue, prepared by collagenase digestion without separation of exocrine and endocrine components, was transplanted into the splenic pulp of 12 dogs made diabetic by total pancreatectomy. Four dogs (group 1) were given autotransplants, and all became euglycemic 4.5 +/- 1.5 days (mean +/- SE) after the transplantation was done. Three of these dogs remained euglycemic until splenectomized 60 days after transplantation was done. Four dogs (group 2) given allogeneic transplants from histocompatible littermates within the same group were administered cyclosporine (40 mg/kg of body weight/day; starting 2 days before transplantation was done until dogs were splenectomized), and 3 of these dogs became euglycemic 8.0 +/- 2.0 days after the transplant was done. Two of the 3 dogs that became euglycemic remained so until splenectomized 60 days after transplantation was done, and the 3rd was euglycemic until 31 days after transplantation. Four dogs (group 3) given allogeneic islet transplants from nonrelated histocompatible donors within the same group were given cyclosporine (40 mg/kg/day; as described for group 2), and none became euglycemic.

Animals↗
PubMed1984

Polytetrafluoroethylene versus autogenous vein grafts for vascular reconstruction in contaminated wounds.

A high incidence of dissolution and disruption of infected autogenous vein grafts has been demonstrated. PTFE, on the other hand, has been shown to maintain its structural integrity in the presence of well-entrenched infection, with a relatively small incidence of anastomotic disruption related to host artery necrosis. In addition, PTFE performed as well as autogenous vein when antibiotics were administered. Therefore, PTFE graft material is advocated for controlled clinical trials in patients with contaminated vascular injuries.

Animals↗
PubMed1979

Renal and ureteral duplication in a dog.

Duplication of a kidney and ureter in an 18-month-old male English Bulldog was demonstrated radiographically and was confirmed surgically. Urinary tract infection had been a problem for a year. Antimicrobial therapy resolved the clinical signs of urinary infection but did not eliminate bacteriuria.

Animals↗
PubMed1972

Immune reactions in mucous membranes. IV. Histochemistry of intestinal mast cells during helminth expulsion in the rat.

The histochemistry of intestinal (IMC) and connective tissue mast cells (CTMC) in the normal rat is compared. Acid mucopolysaccharide appears to be less strongly sulfated and the granule content of monoamines is lower in IMC. After infection with the intestinal helminth, Nippostrongylus brasiliensis, the mucosal content of IMC is altered. During the early phase of immunologic expulsion of this parasite (self-cure) the IMC proliferate and differentiate; the histochemical properties of the granules appear to reflect this process. Very large numbers of mature IMC are found in the mucosa during the later, rapid phase of worm expulsion. Both acid mucopolysaccharide and monoamines are depleted from the granules of these cells; this is consistent with previous studies suggesting that IMC discharge occurs at this stage. These findings lend further support to the hypothesis that the biogenic products of IMC discharge are responsible for the increase in mucosal permeability which occurs during self-cure and which may facilitate the rapid translocation of antiworm antibody into the intestinal lumen.

Animals↗
PubMedDate not supplied

Significance of the Heineke-Mikulicz pyloroplasty in the treatment of gastric dilatation-volvulus. A prospective clinical study.

Twenty-six dogs with gastric dilatation-volvulus (GDV) were stabilized medically, followed by tube gastrostomy and gastropexy. In 13 dogs, a Heineke-Mikulicz pyloroplasty was also performed. Complications and recurrences were monitored during the immediate postoperative period and for 5 to 31 months thereafter. Barium gastrograms and contrast radiographs of the stomach were evaluated at week 1 and months 5 to 31. Significantly fewer dogs without pyloroplasty had complications during the immediate postoperative period. There were no differences in the long-term complication rates. Radiographic evaluations of the width of the pylorus, the size of the stomach, and the rate of gastric emptying showed no differences between dogs with and without pyloroplasty at any evaluation period. The Heineke-Mikulicz pyloroplasty increased the immediate postoperative complication rate after surgical fixation of the stomach for the treatment of GDV. It did not appear to influence the long-term outcome of the surgical treatment of this disease. The Heineke-Mikulicz pyloroplasty is not recommended in the treatment of GDV unless pyloric outflow obstruction can be demonstrated.

Animals↗
PubMedDate not supplied

Gastric conduit urinary diversion in normal dogs. Part I, Upper urinary tract structure, function, and sepsis.

The urinary bladder of 10 clinically normal dogs was excised and the ureters were implanted into an isolated, vagotomized gastric segment derived from the fundic region of the stomach. The gastric segment was closed to form a conduit. Continence was maintained with a modified Kock "nipple valve" created from an isolated segment of ileum. Four dogs were euthanatized by day 30 because of complications related to the early onset of renal failure and electrolyte alterations. Six dogs were euthanatized on day 150. Ureteral dilatation, hydronephrosis, and decreased endogenous creatinine clearance rates were measured in all dogs at the end of the survival period. Pyelonephritis was diagnosed histologically in seven dogs. Positive renal cultures were obtained from seven dogs at necropsy. It was concluded that gastric conduit urinary diversion is unsatisfactory for long-term or short-term clinical use in dogs.

Animals↗
PubMedDate not supplied

Gastric conduit urinary diversion in normal dogs. Part II, Hypochloremic metabolic alkalosis.

Gastric conduit urinary diversion was performed in 10 dogs after complete cystectomy. Four dogs were euthanatized on day 30 because of hypochloremic metabolic alkalosis and renal failure. Hematologic and biochemical changes in six dogs evaluated for 120 days were compatible with hypochloremic metabolic alkalosis. The continuous loss of hydrochloric acid from the gastric conduit resulted in significant increases in arterial blood pH, PaCO2, anion gap, TCO2, and the concentration of HCO3-. There were significant decreases in PaO2 and the serum concentrations of chloride and potassium. Deterioration of renal function resulted in all dogs. It was concluded that hypochloremic metabolic alkalosis makes gastric conduit urinary diversion unsatisfactory for clinical use in dogs.

Acid-Base Equilibrium↗
PubMedDate not supplied

Long-term results of complete and partial ligation of congenital portosystemic shunts in dogs.

The medical records of 65 dogs that underwent complete or partial ligation of a single congenital portosystemic shunt (CPSS) were reviewed to determine the long-term clinical clinical results. Information retrieved from the records included age at surgery, preligation (baseline) portal pressure, postligation portal pressure, change in portal pressure from baseline, complete or partial occlusion of the shunting vessel and fasting, and 2-hour postprandial bile acids from the preoperative, early postoperative (PO), and greater than 1 year PO time periods. A clinical rating score derived from a follow-up examination greater than 1 year PO was assigned to each dog. Of the 56 dogs that survived the perioperative period, 29 (52%) had complete and 27 (48%) had partial ligations. Age at surgery, pre- and postligation portal pressure, change in portal pressure from baseline and serum bile acid concentrations were not related to long-term clinical outcome. Clinical rating scores were significantly greater for dogs with partial CPSS ligations compared with dogs with complete ligations, indicating a less favorable clinical outcome for partial ligations. Fasting and 2-hour postprandial bile acid values at both PO time intervals were significantly greater in partial versus complete ligation groups. Follow-up information for more than 1 year was available on 18 of 29 dogs (62%) with complete ligations. All were clinically normal. Of 27 dogs with partial ligations, 11 dogs (41%) developed recurrence of clinical signs resulting in presentation to the university or referring veterinarian for additional surgery, medical management, or euthanasia. Only three dogs with partial CPSS ligation (11%) were clinically normal.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

The medial saphenous fasciocutaneous free flap in dogs.

The purpose of this study was to identify the angiosome of the medial saphenous artery and vein and to evaluate the use of this cutaneous angiosome as a free skin flap in the dog. In phase 1 of this study, selective angiography of the medial saphenous artery performed in six canine cadavers showed that the skin covering the entire medial femorotibial area, the distal half of the caudal head of the sartorius muscle, and the gracilis muscle were perfused by the medial saphenous artery. In phase 2, a medial saphenous fasciocutaneous island flap was raised and sutured back to the skin edges of the donor wound in three dogs. One hundred percent survival of all of the flaps occurred. In phase 3, a medial saphenous fasciocutaneous microvascular free flap was transferred to a wound that was created over the dorsal metacarpal (n = 3) or metatarsal region (n = 3). The mean length +/- SD of the medial saphenous vascular pedicle was 80 +/- 13 mm (n = 5); the mean diameter +/- SD of the medial saphenous artery was 2.8 +/- 0.2 mm (n = 5) and the mean diameter +/- SD of the medial saphenous vein was 4.2 +/- 0.2 mm (n = 5). One hundred percent of all flaps survived (n = 6). Selective angiography or the distal cranial tibial artery (metatarsal wounds, n = 3) and the median artery (metacarpal wound, n = 3) was performed 3 weeks after surgery. All of the vascular anastomoses were patent and neovascularization of the wound beds was present. This free flap was found to be acceptable for cosmetic reconstruction of wounds located on the distal extremity.

Animals↗
PubMedDate not supplied

Evaluation of the cranial rectus abdominus muscle pedicle flap as a blood supply for the caudal superficial epigastric skin flap in dogs.

This study evaluates the cranial rectus abdominus muscle pedicle flap as the sole blood supply for the caudal superficial epigastric skin flap. This flap was composed of a cranially based rectus abdominus muscle pedicle flap that was attached to the caudal superficial epigastric island skin flap (including mammary glands 2 to 5) via the pudendoepigastric trunk. Selective angiography of the cranial epigastric artery in eight cadaver dogs proved that the arterial vasculature in the cranial rectus abdominus was contiguous with that in the caudal superficial epigastric skin flap. In the live dog study, three of six of the flaps failed because of venous insufficiency. Necrosis of mammary gland 2 occurred in two of six flaps. One of six flaps survived with the exception of the cranial most aspect of mammary gland 2. Angiography of the cranial epigastric artery proved that arterial blood supply to these flaps was intact. Histological evaluation of the failed flaps showed full-thickness necrosis of the skin and subcutaneous tissues, the presence of severe congestion, and venous thrombosis. Retrograde venous blood flow through the flap was inconsistent, and hence resulted in failure of this myocutaneous flap. Use of this flap for clinical wound reconstruction cannot be recommended.

Angiography↗
PubMedDate not supplied

Myoperitoneal microvascular free flaps in dogs: an anatomical study and a clinical case report.

The purpose of the anatomical study was to identify potential myoperitoneal microvascular free flaps, in dogs, that are based on a single artery and vein. The angiosomes of the right deep circumflex iliac artery and left phrenicoabdominal (cranial abdominal) artery were evaluated in six medium-sized canine cadavers. The right deep circumflex iliac artery and left phrenicoabdominal (cranial abdominal) artery were injected with a mixture of barium and latex (equal parts). The entire right and left transversus abdominis muscles were dissected from the abdominal wall and radiographed. The angiograms of the deep circumflex iliac artery showed poor arborization of the vessels within the transversus abdominis muscle in all six cadavers. The angiograms of the phrenicoabdominal (cranial abdominal) artery showed consistent filling of the vascular bed of the cranial half of the transversus abdominis muscle flap in all six dogs. The vascular pedicle lengths and the diameter of the arteries and veins of both the deep circumflex iliac and phrenicoabdominal (cranial abdominal) myoperitoneal free flaps were found to be acceptable for microvascular anastomosis. The deep circumflex iliac flap was unacceptable because of inadequate vascular perfusion. The cranial abdominal artery had a consistent, large branch that supplied the cranial half of the transversus abdominis muscle, thereby making a myoperitoneal flap supplied by this vessel a potentially useful free flap. An 8-year-old male, neutered, mixed-breed dog was evaluated for possible repair of a large defect of the hard palate. Previous operations, using local tissue flaps, had been unsuccessful. A myoperitoneal free flap, based on the right cranial abdominal artery, and consisting of the cranial portion of the transversus abdominis muscle, was used successfully to reconstruct the hard palate. Migrating epithelium from the edges of the wound covered the myoperitoneal flap by 10 weeks after surgery. Therefore, the cranial abdominal myoperitoneal free flap can be considered for reconstruction of intra-oral defects that cannot be repaired using conventional local flap techniques.

Abdominal Muscles↗