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Biomedical subjects

C A Rawlings

Publications and source records attributed to C A Rawlings.

At least 19 recordsLinked to original sources
PubMed2001

Results of cystometry and urethral pressure profilometry in dogs sedated with medetomidine or xylazine.

OBJECTIVE: To compare effects of medetomidine and xylazine hydrochloride on results of cystometry and micturition reflexes in healthy dogs and results of urethral pressure profilometry (UPP) in sedated and conscious dogs. ANIMALS: 20 dogs. PROCEDURES: Urodynamic testing was performed 6 times in each dog (3 times after administration of xylazine [1 mg/kg of body weight, IV] and 3 times after administration of medetomidine (30 microg/kg, IM). Before each episode of sedation, UPP was performed. Heart and respiratory rates and indirect blood pressures were recorded prior to and 5, 10, 20, and 30 minutes after injection of sedative. Cystometry measurements included threshold volume, threshold pressure, and tonus limb. The UPP measurements included maximal urethral closure pressure (MUCP), functional profile length, and, in male dogs, plateau pressure. RESULTS: Mean MUCP was decreased markedly in xylazine- and medetomidine-sedated dogs. Xylazine and medetomidine also decreased plateau pressure in male dogs. The MUCP measurements were consistent among days for conscious and xylazine-sedated dogs but were inconsistent for medetomidine-sedated female dogs. The proportion of valid cystometry measurements was greater for xylazine (39 of 60) than for medetomidine (27 of 60). Cystometry was considered invalid when bladder pressure reached 30 cm H2O without initiation of a micturition reflex. CONCLUSIONS AND CLINICAL RELEVANCE: Medetomidine and xylazine have similar effects on measurement of UPP and cystometry. Medetomidine was less consistent among days for UPP in female dogs and produced fewer valid cystometry tests, compared with xylazine. For urodynamic evaluations, medetomidine administered IM cannot be substituted for xylazine administered IV.

Animals↗
PubMed2001

A rapid and strong laparoscopic-assisted gastropexy in dogs.

OBJECTIVE: To develop a technique for laparoscopic gastropexy in dogs and evaluate effects on stomach position and strength of the adhesion between the stomach and abdominal wall. ANIMALS: 8 healthy dogs. PROCEDURE: Dogs were anesthetized, and the abdomen was insufflated with carbon dioxide. A laparoscope was placed through a cannula inserted on the abdominal midline caudal to the umbilicus. Babcock forceps placed through a cannula inserted lateral to the right margin of the rectus abdominus muscle were used to exteriorize the pyloric antrum, a longitudinal incision was made through the serosa and muscular layer of the pyloric antrum, and the seromuscular layer of the pyloric antrum was sutured to the transversus abdominus muscle. After surgery, positive-contrast gastrography was used to evaluate stomach position and the onset of gastric emptying, and ultrasonography was used to assess stomach wall activity and mobility. Dogs were euthanatized 1 month after surgery, and tensile strength of the adhesion was tested. RESULTS: In all dogs, stomach position and the onset of gastric emptying were normal 25 days after surgery, and the pyloric antrum was firmly attached to the abdominal wall 30 days after surgery. Mean +/- SD ultimate load of the adhesion in tension was 106.5 +/- 45.6 N. CONCLUSIONS AND CLINICAL RELEVANCE: The laparoscopic gastropexy technique described in the present study could be performed quickly and easily by an experienced surgeon, resulted in a strong fibrous adhesion between the stomach and abdominal wall, and appeared to cause minimal stress to the dogs.

Abdominal Muscles↗
PubMed2000

Development of a molecular probe to baboon interleukin-10 mRNA for in situ hybridization during experimental schistosomiasis.

A nucleic acid probe complementary to baboon interleukin 10 (IL-10) mRNA was developed for in situ hybridization. Highly conserved IL-10 protein sequences from several mammals were aligned to design oligonucleotide primers flanking a 270-bp sequence of the target cDNA. RNA was isolated from stimulated peripheral blood mononuclear cells (PBMC). IL-10 cDNA was reverse-transcribed from the total PBMC RNA and amplified with the polymerase chain reaction (PCR). Cloning and sequencing of the PCR product confirmed it to be of baboon IL-10 origin, with 97.8% identity to human and 100% identity to macaque mRNA sequences. The baboon IL-10 DNA probe hybridized in Southern blots to a 7.9-Kbp or 8.6-Kbp band after digestion of genomic baboon DNA with Bam H1 or Eco R1, respectively. Preliminary results with an antisense riboprobe derived from this sequence showed the presence of IL-10 mRNA in sections of granulomatous tissues.

Animals↗
PubMed2000

Immediate urodynamic and anatomic response to colposuspension in female Beagles.

OBJECTIVE: To characterize urodynamic function and anatomy before and after colposuspension in anesthetized female Beagles. ANIMALS: 12 adult female Beagles. PROCEDURE; During general anesthesia (thiopental sodium induction and halothane maintenance), urethral pressure profiles, leak point pressure measurements with a 50-ml bladder volume, positive contrast cystograms, and retrograde vaginourethrocystograms were performed. A caudal midline laparotomy was used to perform colposuspension. Urodynamic and radiographic studies were repeated after surgery. RESULTS: Leak point pressures were increased (120 to 168.9 cm H2O), and maximum urethral closure pressures decreased (43.7 to 19.3 cm H2O ) after colposuspension. The urethra and bladder were moved cranially; the external urethral orifice was positioned closer to the pelvic cavity, and the neck of the bladder was positioned more cranially into the abdomen. Length of the urethra, as measured by use of vaginourethrocystograms, was increased by 3%. As measured by use of urethral pressure profiles, total profile length was increased by 19.9%, and functional profile length was increased by 19.2%. CONCLUSIONS AND CLINICAL RELEVANCE: Increased leak-point pressure correlated with the expected clinical improvement attributable to colposuspension. Increased exposure of the urethra to abdominal and pelvic cavity pressures may be the mechanism by which incontinent dogs become continent after colposuspension. Results of the leak-point pressure test may correlate with clinical behavior before and after colposuspension for treatment of incontinence.

Anesthesia, General↗
PubMed2000

Serial laparoscopic biopsies of liver and spleen from Schistosoma-infected baboons (Papio spp.).

PURPOSE: To obtain large, serial biopsy samples from the liver and spleen by using laparoscopy. Large samples were needed for measurement of inflammatory mediators during various stages of schistosomiasis. METHODS: Each of the seven female baboons (Papio sp.) underwent as many as three laparoscopies, for a total of 19 laparoscopic procedures. This process permitted sampling of the liver, spleen, and mesenteric lymph nodes before and at 6 and 9 weeks after infection with Schistosoma mansoni. All surgery was performed through three trocar sites. Postoperative care included preemptive analgesia. After surgery, we monitored the animals' appetite and measured the core body temperature and activity by using implanted radiofrequency transmitters. RESULTS: We obtained samples of the liver and splenic biopsies during all 19 laparoscopic procedures. The mean weight of the liver biopsies was 3.7 g and that of the spleen samples was 5.3 g. We encountered small adhesions during 5 of the 12 reoperations. Eating and activity rapidly returned after surgery. CONCLUSIONS: Laparoscopy permitted collection of large, serial biopsies with apparently limited stress to the animals. Laparoscopy can be used for biopsies in studies to characterize disease response, confirm normal organ histology prior to drug toxicity studies, determine target-organ drug concentrations in pharmacokinetic studies, and measure drug residues. This refinement likely will reduce required animal numbers by decreasing the effect of surgery compared to that of the experimental conditions, enhance animal well-being, and permit repeated measurements in an animal that serves as its own control.

Analgesics, Opioid↗
PubMed1999

Stress leak point pressures and urethral pressure profile tests in clinically normal female dogs.

OBJECTIVE: To develop a stress leak point pressure (LPP) test for dogs, determine LPP for continent female dogs, and determine urethral pressure profile (UPP) values for nonanesthetized, continent female dogs. ANIMALS: 22 continent female dogs weighing from 21 to 29 kg. PROCEDURE: A standard UPP test and a modification of the LPP test used in women were performed on all dogs. On 3 occasions, dogs underwent UPP testing while awake. They then were anesthetized with propofol, and LPP was measured at bladder volumes of 75, 100, and 150 ml. For LPP tests, abdominal pressure was applied by inflating a human blood pressure cuff placed around the dog's abdomen. LPP were recorded through a urethral catheter (bladder LPP) and a rectal balloon catheter (abdominal LPP). RESULTS: Mean +/- SD and median maximal urethral closure pressure was 110.1+/-20.2 and 109.0 cm water, respectively. Mean bladder LPP for the 75, 100, and 150 ml bladder volumes was 172.4 cm water. Significant differences among LPP for the 3 bladder volumes were not detected. CONCLUSIONS: Stress LPP can be recorded in female dogs.

Animals↗
PubMed1997

Comparison of thoracic radiographs with images transmitted via advanced telecommunications equipment.

OBJECTIVE: To compare thoracic radiographs of clinically normal dogs and dogs with mild clinical heartworm disease with images transmitted by a desk-top, two-way audiovisual teleconferencing system. DESIGN: Prospective, matched-set study. STUDY POPULATION: 50 thoracic radiographs from clinically normal and heartworm-infected dogs and the digitally transmitted images of those radiographs. PROCEDURE: Thoracic radiographs from 25 clinically normal dogs and 25 dogs infected with 1 to 24 heartworms were evaluated by 3 clinicians. Using classic criteria for heartworm disease, evaluations of radiographs and images transmitted digitally over 2 high-speed data-transfer telephone lines (56 kilobits/s/line) were performed. Clinicians were asked to determine whether dogs had radiographic signs of heartworm disease. RESULTS: Clinicians' ability to detect heartworm disease did not differ between interpretations of radiographs and those of transmitted images. CLINICAL IMPLICATIONS: Radiographic images transmitted via a teleconference system can be used to provide reliable diagnostic information. Thoracic radiographs can be interpreted at a remote site permitting rapid consultation and immediate advice on clinical management.

Animals↗
PubMed1997

Use of partial prostatectomy for treatment of prostatic abscesses and cysts in dogs.

OBJECTIVE: To determine whether dogs had prostatic disease, urinary incontinence, or urinary tract infection 1 year after partial prostatectomy to treat prostatic abscesses and cysts. DESIGN: Prospective study. ANIMALS: 20 male dogs with prostatic abscesses or cysts. Fifteen dogs had evidence of urinary tract infection. Only 8 dogs urinated normally; the remainder dribbled, had obstructions, or required medical treatment. PROCEDURE: Partial prostatectomy was performed on each dog. Sexually intact dogs (n = 12) also were castrated. RESULTS: None of the dogs had return of prostatic cystic enlargement or clinical signs of prostatic disease during the first year after surgery. Two dogs were euthanatized within 1 year after surgery, with 1 dog having prostatic enlargement and adenocarcinoma and 1 dog having unrelated lymphosarcoma. Fifteen dogs were continent. The remaining 5 dogs urinated normally but had intermittent and minor incontinence. Eleven dogs had no signs of infection 1 year after surgery, 5 had pyuria or positive urine bacteriologic culture results, 2 did not have urinalysis performed, and 2 were euthanatized. CLINICAL IMPLICATIONS: Dogs with severe prostatic abscesses or cysts and infections can be successfully treated by partial prostatectomy with an ultrasonic surgical aspirator and castration, resulting in long-term disease resolution. Although most dogs with severe prostatic disease do not urinate normally before surgery, nearly all dogs resume normal micturition after partial prostatectomy. Postoperative results of partial prostatectomy appear to be better than those of previous drainage techniques for treatment of prostatic cavitary disease.

Abscess↗
PubMed1997

Production of polyclonal antibodies to feline tumor necrosis factor.

Two 13-amino-acid peptides were synthesized based on the putative feline tumor necrosis factor (FeTNF) sequence. The synthesized peptides were conjugated to keyhole limpet hemocyanin, emulsified in complete Freund's adjuvant, and injected into rabbits. The gene for FeTNF was cloned into the FLAG (International Biotechnologies Inc. [IBI], Kodak, New Haven, Conn.) fusion protein expression vector. The expressed fusion protein was purified by using the M-1 anti-FLAG octapeptide monoclonal antibody (IBI, Kodak). The fusion protein was emulsified in complete Freund's adjuvant and injected into chickens. The immune sera generated to the synthetic peptides and the fusion protein recognized the recombinant FeTNF fusion protein on Western or dot blot assay. The preimmune and immune sera were incubated with naturally occurring FeTNF (supernatants from lipopolysaccharide-stimulated cultured feline peritoneal exudate or peripheral mononuclear cells). The antibody raised to the recombinant FeTNF fusion protein and N-terminal synthetic peptide neutralized bioactivity of native FeTNF and recombinant human TNF. Preimmune sera did not have any neutralizing activity. The polyclonal antibodies were not specific for FeTNF, since both porcine and human recombinant TNF were neutralized by the fusion protein antibodies. The synthetic peptide antibodies recognized recombinant feline and equine TNF on a Western blot.

Animals↗
PubMed1996

Clinical, hematologic, and biochemical features of a syndrome in Bernese mountain dogs characterized by hepatocerebellar degeneration.

Seven related Bernese Mountain Dogs developed a syndrome Characterized by progressive cerebellar and hepatic disease. Clinically, stiffness in the hind limbs, mild incoordination, and a slight head tremor were first noticeable when pups were 4 to 6 weeks old. The condition progressed, causing pups to assume a wide-based stance. Other signs included head bobbing, spontaneous nystagmus, and, finally, paresis. Hematologic findings included leukocytosis with a left shift; normocytic, normochromic anemia; hypoproteinemia, low serum creatinine, and urea nitrogen concentrations; excessive fasting plasma ammonia concentration; and an increase in concentration of serum bile acids. Portal venography performed on 1 dog revealed a small liver and extensive extrahepatic varicosities. Necropsy revealed cerebellar hypoplasia, nodular liver, extensive abdominal varicosities, and ascites. Histologically, degeneration and depletion of Purkinje's cells and vacuolation, degeneration, and nodular regeneration of hepatic tissues were evident. Preliminary analysis of the pedigree was suggestive of an autosomal recessive pattern of inheritance.

Animals↗
PubMed1995

Surgical removal of heartworms from a cat with caval syndrome.

Caval syndrome was diagnosed in a 4-year-old male domestic shorthair cat with severe dyspnea attributable to chylothorax. The diagnosis of heartworm infection was made on the basis of the ultrasonographic detection of a large number of adult heartworms in the right side of the heart and positive results for modified Knott's and heartworm antigen tests. Heartworms were surgically removed through an incision in the jugular vein, using a string-type horsehair brush and an alligator forceps. All clinical signs resolved after the surgery. Although treatment with agents that would kill the adult heartworms was considered, surgical treatment was used on the cat reported here. Surgical treatment may be the method of choice for use in cats with severe or persistent clinical signs attributable to infections with large numbers of heartworms.

Animals↗
PubMed1995

Tumor necrosis factor production in cats in response to lipopolysaccharide: an in vivo and in vitro study.

Supernatants from feline peritoneal exudate cells (PECs) exposed to lipopolysaccharde (LPS) produced significantly (P < 0.05) more tumor necrosis factor (TNF) activity than supernatants from cells exposed to media. An in vitro LPS response was obtained following incubation of whole blood with 10 micrograms ml-1 LPS for 2 h. Intravenous infusion of LPS (750 micrograms kg-1 rapidly increased plasma TNF activity to a maximum at 60 min after initiation of LPS infusion. By 180 min, TNF activity returned to baseline. Cats produce TNF in response to LPS in a manner similar to other species. Measurement of TNF activity in plasma or in LPS-stimulated whole blood are methods to further characterize the inflammatory response in feline diseases.

Animals↗
PubMed1995

Video-assisted percutaneous cystoscopy of the bladder and prostatic urethra in the dog: new approach for visual laser ablation of the prostate.

A new minimally invasive approach for video laparoscopy was developed to access the bladder and prostatic urethra of the dog in order to perform laser ablation of the prostate without using either an open laparotomy or urethrostomy. During general anesthesia, a 10-mm laparoscope was introduced into the peritoneal cavity. Under direct vision, the bladder was distended, and trocars were placed percutaneously by two different methods. A 22F cystoscope was introduced through the transcystic trocar into the prostatic urethra for visual laser ablation of the prostate (VLAP). In all eight dogs, the video-assisted technique for percutaneous access to the prostatic urethra was successful. No complications were associated with placement of the Veress needle, creation of the pneumoperitoneum, or accessing of the bladder lumen and proximal urethra. The visibility in the peritoneal cavity was excellent, and hemorrhage was minimal in all cases. In two dogs, a laparotomy was performed after displacement of the cystoscope from the urinary bladder. Irrigation fluid for the cystoscope drained primarily around the trocar cuff surrounding the instrument. In one case, the irrigation fluid drained around the trocar in the bladder and filled the peritoneal cavity.

Animals↗
PubMed1995

A wire loop technique for ligation of patent ductus arteriosus.

A novel, yet simple and inexpensive, technique is described for the safe passage of suture material for closure of patent ductus arteriosus in small animals. The risk of haemorrhage is reduced by minimising dissection with forceps and by preventing inadvertent grasping of perivascular connective tissue.

Animals↗
PubMed1995

Expression of recombinant feline tumor necrosis factor is toxic to Escherichia coli.

The tumor necrosis factor (TNF) genes from cats, horses, and pigs have all been cloned into the pFLAG-1 fusion protein expression vector (International Biotechnologies, Inc., Kodak, New Haven, Conn.). Growth curves for Escherichia coli containing the pFLAG-1 vector alone and the pFLAG-1 vector containing the TNF gene from each species were determined by visible light spectrophotometry (at 600 nm). Porcine TNF, equine TNF, and feline TNF cultures had slower doubling rates than cultures containing the pFLAG-1 vector alone. Cultures of cells transformed with feline TNF reached peak densities at 3 to 4 h and then decreased to near initial densities prior to the recovery of growth. The induction of expression with isopropyl-beta-D-thiogalactopyranoside (IPTG) arrested the growth of fresh feline TNF cultures for 6 h, which was followed by complete recovery. This inhibition occurred in two strains of E. coli (LL308 and JM101). Induced feline TNF cultures expressed the TNF-FLAG fusion protein for the first 6.5 h. Uninduced cultures expressed low levels of fusion protein. The feline TNF-pFLAG-1 vector was purified from cells expressing fusion protein and from cells with recovered growth curves. Sequencing the vector demonstrated the complete feline TNF gene and tac promoter in cells expressing the fusion protein and a deletional mutation of the tac promoter site in recovered cells. In contrast to equine and porcine TNF, the expression of recombinant feline TNF is toxic to E. coli. Alterations in protein folding and the prevention of secretion of the feline protein may explain the toxic effect.

Animals↗
PubMed1993

Semiquantitative test for Dirofilaria immitis as a predictor of thromboembolic complications associated with heartworm treatment in dogs.

A semiquantitative heartworm test of antigen concentration was evaluated as a predictor of thromboembolism after adulticide treatment. Seventeen dogs with naturally acquired infections of Dirofilaria immitis (heartworms) were studied before and after thiacetarsamide treatment, using physical examinations, arterial blood gas analyses, thoracic radiography, and pulmonary hemodynamic and arteriographic tests. Eight dogs were considered to have a low burden of heartworms and 9 had a high burden. Dogs with a high worm burden had more severe pulmonary thromboembolism with pulmonary hypertension, dilated pulmonary arteries, flow obstruction of the caudal pulmonary arteries, and parenchymal lesions in the caudal lung lobes. Dogs with a low worm burden had minimal changes. Within each group of dogs, the severity of thromboembolism was less in some dogs in which all heartworms were not killed. Six of the 9 dogs with a high burden of heartworms had surviving heartworms, and 1 of these dogs had 38 live heartworms. Only 4 of the 8 dogs with a low worm burden had complete heartworm mortality, but only 1 dog had more than 3 surviving heartworms. We concluded that dogs with a high worm burden were more likely to have pulmonary thromboembolism after thiacetarsamide treatment and that dogs with a low worm burden were more likely to have minimal changes. A semiquantitative heartworm test of antigen concentration is recommended as part of the pretreatment evaluation of dogs infected with heartworms.

Animals↗
PubMed1993

Pulmonary thromboembolism and hypertension after thiacetarsamide vs melarsomine dihydrochloride treatment of Dirofilaria immitis infection in dogs.

The severity of pulmonary thromboembolism and pulmonary hypertension induced by heartworms dying after administration of 2 adulticides was evaluated. Because melarsomine dihydrochloride (RM340) has been shown to be more effective in killing Dirofilaria immitis (heartworms) than the traditional approved adulticide, thiacetarsamide, an attempt was made to determine whether this new adulticide induced more severe lung disease. Before adulticide treatment, 32 dogs with naturally acquired heartworm infections received physical examinations, semiquantitative antigen concentration tests, CBC, platelet counts, serum biochemistry analyses, arterial blood gas determinations, thoracic radiography, pulmonary arteriography, and pulmonary hemodynamic tests. Eight dogs with a low burden and 9 dogs with a high burden of heartworms were treated with thiacetarsamide, and 7 dogs with a low burden and 8 dogs with a high burden were treated with RM340. Except for the heartworm-burden test, tests were repeated at regular intervals during the first 7 weeks after treatment. None of the dogs coughed or had dyspnea after treatment. Six of 9 dogs with high worm burdens and 4 of 8 dogs with low worm burdens had surviving heartworms after thiacetarsamide treatment, in contrast to only 3 of 15 RM340-treated dogs. Differences between the 2 adulticide treatments were minimal as determined by thoracic radiography, pulmonary hemodynamic tests, clinical laboratory analyses, pulmonary arteriography, or necropsy. The RM340 treatment was a more effective adulticide, but it did not increase the severity of hypertension and thromboembolism.

Animals↗