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Biomedical subjects

C A Buffington

Publications and source records attributed to C A Buffington.

At least 37 records · Page 2Linked to original sources
PubMed1998

High affinity binding sites for [3H]substance P in urinary bladders of cats with interstitial cystitis.

PURPOSE: Pain is a common feature of interstitial cystitis (IC). Although the effects of IC on sensory neuron density have been investigated, its influence on substance P receptor (SPR) numbers and function are not well known. To evaluate the role of SPR in cats with IC, we measured the affinity (Kd), numbers (Bmax), and substrate specificity of binding sites for [3H]SP in urinary bladders of healthy cats and cats suffering from IC. MATERIALS & METHODS: Radioligand binding assays of cat and rat brain, normal cat bladders, and inflamed bladders from cats diagnosed with IC were conducted using [3H]SP to determine SPR affinity and numbers. Binding sites for [125I]SP were identified using autoradiography in slide-mounted frozen tissue sections, and their specificity determined with competition binding studies. RESULTS: In bladder homogenate binding studies, low affinity SP binding sites for [3H]SP were found both in normal and inflamed tissue, whereas high affinity binding sites were found in inflamed bladder tissue only. Based on autoradiographic studies, high affinity binding appeared to be to small blood vessels, and to be specific for substance P, a pharmacology consistent with the neurokinin-1 receptor (NK1R). CONCLUSIONS: Upregulation of NK1R may be part of the pathophysiology of IC, as it is in some other inflammatory diseases. If so, more specifically targeted therapies for IC may become available.

Animals↗
PubMed1997

Results of retrograde urethrography in cats with idiopathic, nonobstructive lower urinary tract disease and their association with pathogenesis: 53 cases (1993-1995).

OBJECTIVE: To describe results of retrograde urethrography in cats with idiopathic, nonobstructive lower urinary tract disease (LUTD), to review the normal anatomy of the feline urethra, and to relate anatomy observed radiographically to the pathogenesis and diagnosis of LUTD in cats. DESIGN: Retrospective case series and anatomic study. ANIMALS: 53 cats with signs of nonobstructive LUTD for which an underlying cause could not be determined. Results for these cats were compared with those for 6 healthy female cats undergoing urethrocystoscopy for another study and 6 male cats without a history of LUTD undergoing necropsy examination. PROCEDURE: Medical records, results of positive-contrast retrograde urethrography (cats with idiopathic, nonobstructive LUTD) and urethrocystoscopy (healthy female cats), and necropsy findings (healthy male cats) were reviewed. RESULTS: Abnormalities were not detected during urethrocystoscopy, dissection, or urethrography. Previously, the urethra in male cats has been described simply as a long tube that tapers caudally, and the only structures consistently differentiated by radiography have been pelvic and penile parts. In this study, the seminal colliculus, isthmus of the urethra, preprostatic part of the urethra, and urethral crest were consistently observed in male cats in addition to pelvic and penile parts. The urethral crest also was observed in the comparatively simple female urethra. CLINICAL IMPLICATIONS: During retrograde urethrography in cats, prior distention of the bladder with positive-contrast medium may obscure radiographic signs associated with normal anatomic structures. Knowledge of urethral anatomy and radiographic signs associated with idiopathic, nonobstructive LUTD in cats should improve understanding of the pathogenesis and diagnosis of this disease.

Animals↗
PubMed1997

Clinical evaluation of cats with nonobstructive urinary tract diseases.

OBJECTIVE: To identify the underlying cause of clinical signs in cats with nonobstructive diseases of the bladder and urethra. DESIGN: Prospective case series. SAMPLE POPULATION: 109 cats examined by the urology service of The Ohio State University's veterinary teaching hospital because of stranguria, hematuria, pollakiuria, or urination in inappropriate locations. PROCEDURE: History was obtained and a CBC, serum biochemical analyses, serologic tests for FeLV and feline immunodeficiency virus, urinalysis, bacterial culture of urine, and contrast radiography or urethrocystoscopy (females only) were performed. RESULTS: 16 cats had cystic calculi: 8 had struvite uroliths, 7 had calcium oxalate uroliths, and 1 had a urolith of unknown composition in conjunction with an anatomic defect. Anatomic defects, including diverticulae, urethral strictures, and a malpositioned urethra, were identified in 12 cats. A urinary tract infection was identified in 1 cat, and neoplasia was diagnosed in 2. One of the cats with neoplasia also had a struvite urolith. The remaining 80 cats did not have an anatomic defect, urolith, or tumor. Ten of these cats also did not have radiographic or cystoscopic abnormalities and were presumed to have a behavioral disorder. The remaining 70 cats had radiographic or cystoscopic abnormalities, and idiopathic cystitis was diagnosed. In 14 of the cats with idiopathic cystitis, results of a urinalysis were normal. Cats with idiopathic cystitis were significantly more likely to eat dry food exclusively (59%) than were cats in the general population (19%). CLINICAL IMPLICATIONS: Results suggest that idiopathic cystitis occurs commonly in cats with stranguria, hematuria, pollakiuria, or inappropriate elimination and is associated with consumption of dry foods. Contrast radiography or cystoscopy is necessary for differentiating idiopathic cystitis from behavioral disorders in some cats.

Animal Feed↗
PubMed1997

Excretion of fluorescein in the urine of women with interstitial cystitis.

PURPOSE: Altered bladder permeability may have a role in the pathogenesis of interstitial cystitis. Fluorescein, a fluorescent dye of molecular weight 325, has been used to assess membrane permeability. Orally ingested fluorescein normally is rapidly conjugated to glucuronate by the liver and excreted in the urine. MATERIALS AND METHODS: To test its use as a marker of bladder permeability, we administered fluorescein orally to 6 patients with interstitial cystitis who satisfied National Institutes of Health, National Institute for Diabetes and Digestive and Kidney Diseases criteria and to 6 normal female control subjects. After emptying the bladder and collection of a baseline blood sample, fasted subjects ingested 20 mg. fluorescein and blood samples were collected 1, 2, 3, 4 and 24 hours later. Urine was collected during each of the first 4 hours, and then from 4 to 10, 10 to 16 and 16 to 24 hours. Urine volume was measured, and all plasma and urine samples were analyzed for fluorescein. RESULTS: Plasma fluorescein concentrations (ng./ml.) were significantly (p < 0.05) higher in interstitial cystitis patients than in control subjects at 1 and 2 hours after fluorescein ingestion. Urine fluorescein excretion (mg.) was significantly (p < 0.05) lower in interstitial cystitis patients than in control subjects at 4 to 10 hours after fluorescein ingestion, and for the entire 24 hours. CONCLUSIONS: The increased fluorescein concentration in the plasma and decreased excretion in the urine of interstitial cystitis patients suggest that fluorescein may be a useful marker of altered membrane permeability.

Adult↗
PubMed1997

Effects of choreito consumption on urine variables of healthy cats fed a magnesium-supplemented commercial diet.

OBJECTIVE: To investigate the effect of choreito consumption (500 mg/kg of body weight/d) on struvite crystal formation and signs of lower urinary tract disease (LUTD) in cats consuming a commercial canned diet with 0.5% added inorganic magnesium. SAMPLE POPULATION: 6 male and 6 female adult cats, all considered to be clinically normal on the basis of physical examination findings; results of CBC, serum biochemical analyses, urinalyses, and urine cultures; and freedom from urolithiasis on the basis of urethrocystoscopic (females) or urethrocystographic (males) findings. PROCEDURE: Diets were fed for 12 weeks, or until appearance of signs of LUTD, including dysuria, hematuria, urine pH > 7.0, and severe struvite crystalluria. Presence of at least 2 of these signs was required for removal from study. Urine specimens were examined for electrolytes, struvite crystal content, and hematuria. RESULTS: Results for urine variables were compared between groups at 4 weeks, because of reduction in cat numbers attributable to removal from study. Struvite crystal content of 24-hour urine specimens was significantly lower for cats fed the choreito-containing diet. Moreover, frequency and severity of hematuria were significantly decreased in cats fed the choreito-containing diet. Correlation between hematuria and struvite crystal content was not observed in either group. Additionally, all 6 cats fed the diet without choreito had been removed from study by day 58 because of signs of LUTD. Of the 6 cats fed the choreito-containing diet, 2 completed the 12-week study. CLINICAL RELEVANCE: Choreito may be beneficial for relief of some signs of struvite-associated LUTD disease in cats.

Analysis of Variance↗
PubMed1997

Effects of choreito and takushya consumption on in vitro and in vivo struvite solubility in cat urine.

OBJECTIVE: To determine the effects of the takushya portion of choreito, a traditional Chinese treatment for urolithiasis, on urine and struvite crystal variables in cats fed diets containing takushya. SAMPLE POPULATION: 6 male and 6 female adult cats, all considered to be clinically normal on the basis of physical examination findings, results of CBC, serum biochemical analyses, urinalyses, and urine cultures; and freedom from urolithiasis on the basis of urethrocystoscopic (females) or urethrocystographic (males) findings. PROCEDURE: Cats were fed a commercial canned diet supplemented with 0.1-mg of takushya/kg of body weight, or with 0.5 mg of choreito/kg. Diets were fed, using a Latin-square design, to 3 groups of 4 cats (2 male, 2 female) each for 2 weeks, followed by blood and 24-hour urine sample collections. RESULTS: Consumption of takushya, which comprises 20% by weight of choreito, was not associated with adverse effects in cats at the amounts provided during the period of study. Moreover, takushya was responsible for most of the effect of choreito consumption on reduction of urine pH, and approximately half its ability to reduce struvite crystal formation in cat urine. CLINICAL RELEVANCE: Alternative treatments for struvite urolithiasis in cats may be feasible.

Analysis of Variance↗
PubMed1996

Intermittent alkaline urine in a cat fed an acidifying diet.

Detection of alkaline urine traditionally sends an alert to the clinician to consider the presence of a urease-producing bacterial urinary tract infection, postprandial alkaline tide, or the ingestion of a diet that is nonacidifying. In the cat of this report, acid urine was produced while the cat was in the home environment, but alkaline urine was produced following the stress of a long trip to the veterinarian's office. Stress-induced respiratory alkalosis was highly suspected as the cause for the alkaline urine. If traditional causes for alkaline urine are not apparent for cats that produce alkaline urine at the veterinary clinic, we suggest that urinary pH be determined on samples collected in the home.

Alkalosis, Respiratory↗
PubMed1996

Interstitial cystitis in cats.

Despite much research on FUS, there still is no consensus regarding its cause, or even its definition. We recently have demonstrated that some cases of FUS are similar to interstitial cystitis in human beings. Exclusion of anatomic defects, behavior abnormalities, neoplasia, urolithiasis, urethral obstruction, and urinary tract infection leads one to the diagnosis of interstitial cystitis in cats. This diagnosis suggests the need for new approaches to treatment, including pain management and environmental modification.

Animals↗
PubMed1996

Decreased urine glycosaminoglycan excretion in cats with interstitial cystitis.

PURPOSE: The urine protein and glycosaminoglycan (GAG) excretion of normal cats was compared with that of cats suffering from interstitial cystitis (IC), which is reported to decrease urine GAG excretion in humans. MATERIALS AND METHODS: Total urine GAG concentration was measured in random and 24-hour urine specimens by spectrophotometry by 1,9-dimethylmethylene blue (DMB) chloride. RESULTS: In both random and 24-hour urine samples, GAG and protein concentrations and GAG:creatinine and protein:creatinine ratios all were significantly lower in cats with IC. Total GAG and protein excretion also were significantly lower in 24-hour urine samples from cats with IC. CONCLUSIONS: GAG excretion was decreased in cats with IC, as it is in humans. It is unclear whether this is due to changes in synthesis, metabolism, or bladder permeability.

Animals↗
PubMed1995

Acute feline leukemia virus infection causes altered energy balance and growth inhibition in weanling cats.

Naturally occurring retroviral infections cause progressive weight loss, immune suppression, invasion by opportunistic organisms, and eventual death. Feline leukemia virus (FeLV) inhibited growth and decreased energy intake in seven experimentally infected weanling cats compared with age- and sex-matched controls. Remarkably, changes in energy intake, energy expenditure, and weight gain occurred in the acute phase of infection prior to the systemic/productive bone marrow phase of FeLV infection. In other words, growth inhibition developed before FeLV infection was clinically detectable with use of standard enzyme-linked immunosorbent assay or fixed-cell immunofluorescence assays of circulating neutrophils and platelets. Acutely infected, previremic cats consumed 25% less energy [Day 4 postinoculation to Day 16 postinoculation (p < 0.05)] and expended 20% less energy [Day 8 postinoculation to Day 18 postinoculation (p < 0.05)] compared with control cats. Growth stunting of inoculated cats began by Day 11 postinoculation (p < 0.05) and was not corrected during the remaining 4 months of the study. Thus, experimental FeLV infection causes perturbations of metabolism and energy balance resulting in permanent growth impairment. Secondly, detrimental metabolic effects begin in the acute phase of retroviral infection, prior to the clinically detectable phase of FeLV infection.

Acute Disease↗
PubMed1995

Increased insensible water loss in feline retrovirus-infected cats.

Feline retroviruses such as feline leukemia virus (FeLV) adversely affect the regulation of many vital host systems such as the immune response, erythropoiesis, and nutrient metabolism. In this paper, we describe the disruption of an additional homeostatic mechanism-evaporative water loss-by FeLV. Viremic cats had greater evaporative water losses (24.0 +/- 1.4 gm water/kg per day) at low relative humidity levels (19% to 25% relative humidity) when compared to age- and sex-matched control cats (19.7 +/- 1.4 gm of water/kg per day [P < 0.05]). At relative humidity levels greater than 50%, viremic and control cats had similar evaporative water losses. Viremia also resulted in an elevation in the average body temperature (39.1 +/- 0.5 degrees C) compared to control cats (38.4 +/- 0.3 degrees C) (P < 0.001). However, the energy expenditure of viremic cats (17.14 +/- 1.60 kJ/kg/h) was not significantly different from the energy expenditure of control cats (17.02 +/- 2.22 kJ/kg/h). The elevated body temperature of viremic cats likely causes a greater increase in evaporative water loss at low relative humidity levels and suggests further study of water balance in retroviral infection is warranted.

Animals↗
PubMed1994

New technique and management guidelines for percutaneous nonendoscopic tube gastrostomy.

A percutaneous nonendoscopic gastrostomy tube placement device and a new technique for nonendoscopic gastric feeding tube placement were developed for use in animals weighing < 15 kg. After a successful experimental trial in 7 cats, the tube placement device was used in 8 clinical animals (7 cats and 1 dog). All gastrostomy feeding tubes were placed on the first attempt within 10 minutes. Position of the tube was evaluated by endoscopy in 14 of 15, by radiography in 4 of 15, and by celiotomy and necropsy in 2 of 15 animals, respectively. Placement was comparable to the percutaneous endoscopic technique in all but 1 cat. In this animal, the tube had to be placed existing the skin in a caudoventral location because of severe panniculitis. Complications related to the use of the tube placement device were not observed. Complications related to gastrostomy tube management developed in 5 of 15 animals. The prevalence of clinically important or life-threatening complications (peritonitis or premature removal) was 3 of 15.

Animals↗
PubMed1994

Survey of statistical methods used in the veterinary medical literature.

Articles published in 1992 in 6 veterinary journals were reviewed. In 51% of the articles, statistical analyses were not performed or only descriptive statistics (eg, mean, median, standard deviation) were used. The most commonly used statistical tests were ANOVA and t-tests. Knowledge of 5 categories of statistical methods (ANOVA, t-tests, contingency tables, nonparametric tests, and simple linear regression) permitted access to 90% of the veterinary literature surveyed. These data may be useful when modifying the veterinary curriculum to reflect current statistical usage.

Analysis of Variance↗
PubMed1994

Lower urinary tract disease in cats--new problems, new paradigms.

Companion animal diets may be related to prevention, pathogenesis and/or treatment of diseases of the lower urinary tract. For example, urolithiasis can be either diet induced or nutrient sensitive. One of the most interesting developments in veterinary urolithiasis research has been the recent change in the composition of stones recovered from cats. In 1984, 88% of stones analyzed by quantitative methods were > 70% struvite, whereas < 1% were calcium oxalate. In 1992, the percentage of struvite had dropped to 62, whereas the percentage of calcium oxalate had increased to 24. Another recent development in lower urinary tract disease of cats is the recognition that urolithiasis appears to be a minor cause of the signs of frequency, urgency and hematuria for which patients are presented. This suggests that diet may no longer be involved, or be involved in previously unrecognized ways, in many current cases of this disease. Some of these feline patients may have a disease similar to interstitial cystitis, a disease of humans that appears to be of neuroepithelial origin. Our laboratory has been studying this possibility recently, and many similarities between the two diseases have been found.

Animal Feed↗
PubMed1994

Effect of interstitial cystitis on drug absorption from urinary bladder.

Our laboratory reported previously the in vivo absorption of salicylate and antipyrine from the urinary bladder of healthy rats. The present study extends these findings to examine the effect of interstitial cystitis on bladder permeability to drugs by comparing the bladder absorption of salicylate in healthy cats and cats with feline interstitial cystitis (FIC). Interstitial cystitis is a lower urinary tract disease and may involve inflammation of the bladder. A 25-mg/kg dose of sodium salicylate was instilled into the bladder and a 6-micrograms/kg i.v. dose of [14C]salicylic acid was administered concomitantly to determine systemic clearance in individual animals. In healthy and FIC cats, the clearance was 0.3 and 0.1 ml.min-1.kg-1, and the bioavailability of the intravesical dose was about 1 and 9%, respectively. The apparent bladder absorption rate constant and the peak plasma concentration in FIC cats were 7 to 8 times that in healthy cats. These data indicate a significantly higher bladder permeability to salicylate due to interstitial cystitis. In order to elucidate the cause of the lower clearance in FIC cats, a second study compared the disposition of a 2-mg/kg i.v. dose of salicylate in healthy and FIC cats. It was found that the lower salicylate clearance in FIC cats was due in part to a decreased metabolism in the disease state and also involved slower drug elimination at the higher plasma concentrations secondary to the more extensive absorption of the intravesical dose.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorption↗
PubMed1994

Effects of Tamm-Horsfall glycoprotein and albumin on struvite crystal growth in urine of cats.

Tamm-Horsfall protein (THP) was isolated and purified, using pooled urine collections from clinically normal cats. The effects of feline THP and purified feline serum albumin on urine chemical and struvite crystal variables were compared, using an in vitro crystal growth system and 24-hour samples of pooled urine obtained from 4 cats. Urine samples were placed in wells of cell culture plates, increasing concentrations of ammonium hydroxide were added to adjacent wells to stimulate struvite crystal growth, and the plates were incubated at 37 C. The effect of albumin and THP on crystal growth in sample wells was compared with that in control wells, without protein addition, in the same plate. Crystal growth was assessed by determination of number of crystals and supersaturation index, a scale of crystal habit at different degrees of supersaturation, by use of direct visualization with an inverted microscope. Albumin addition did not have significant effect on either crystal number or supersaturation, compared with controls. Addition of THP significantly (P < 0.05) increased crystal number and supersaturation index. It was concluded that THP significantly (P < 0.05) promoted growth of struvite crystals in feline urine, and thus, may have a role in feline struvite uroliths and struvite urethral plug formation.

Ammonia↗