Suspected fibrocartilaginous embolism in a cat

A 12-year-old cat was presented to the University of Queensland's Small Animal Teaching Hospital with a 1-day history of left hemiparesis of acute onset, with no evidence of trauma or toxin exposure. Neurological examination findings were consistent with a lesion in the caudal left cervical spinal cord (C6 to C8), which was non-painful and had not progressed since the onset of clinical signs. No other abnormalities were found, although myelography showed a mild swelling involving the caudal cervical and cranial thoracic spinal segments. A diagnosis of suspected fibrocartilaginous embolism was made on the basis of the history, clinical presentation and diagnostic tests results, making this case the first report of a suspected fibrocartilaginous embolism in a cat that returned to normal function.

Interference competition and the functional response of oystercatchers searching for cockles by touch

We examined interference competition for food in oystercatchers, Haematopus ostralegus L., feeding on cockles, Cerastoderma edule L., when kleptoparasitism was infrequent. These birds opened cockles by hammering a hole in the shell, searched for them by touch and experienced densities of feeding conspecifics that ranged from 0 to 2362.5 birds/ha. Handling times were not significantly correlated with competitor density, but the probability of successfully opening a cockle declined significantly as competitor density increased because birds were more likely to abandon cockles they had found. Birds were also significantly more likely to carry cockles away from where they were found prior to attempting to open them as competitor density increased. We used an optimal diet model to predict maximum energy intake rates achievable for birds feeding on a given prey population, and experiencing a range of competitor densities. Despite affecting foraging behaviour, the model showed that competitor density had a negligible impact on overall intake rates. Although kleptoparasitism was rare in our study population, only 1.5% (9/586) of cockles being lost to parasites, a recent model suggests that it was likely to be profitable, under the conditions experienced by our birds. We suggest that kleptoparasitism might be infrequent because birds could reduce its likelihood by adjusting their behaviour, with only a minimal cost in terms of a reduced intake rate. Behaviour-based models of interference competition, therefore, need to consider a range of potentially complex avoidance behaviours when attempting to describe the dynamics of this process. Copyright 1998 The Association for the Study of Animal Behaviour

Cognitive function 5 years after randomization to coronary angioplasty or coronary artery bypass graft surgery

BACKGROUND

Coronary bypass surgery often leads to short-term cognitive dysfunction, whereas coronary angioplasty does not. Perioperative cognitive dysfunction usually resolves, although a subgroup of surgical patients may continue to exhibit long-term cognitive dysfunction. The purpose of this study was to compare cognitive function 5 years after randomization to a strategy of either initial coronary surgery or initial angioplasty.

METHODS AND RESULTS

Five centers in the Bypass Angioplasty Revascularization Investigation participated in this ancillary study. Patients with multivessel coronary disease randomized to angioplasty or surgery were eligible at the time of their 5-year clinic visit. A battery of five measures previously shown to be sensitive to perioperative changes in cognitive function was administered, including the Logical and Figural Memory Scales from the Wechsler Memory Scale, the Digit Symbol and Digit Span subtests from the Wechsler Adult Intelligence Scale, and Part B of the Reitan Trail Making Test. The 125 study patients were generally similar to the 133 patients who were eligible but did not participate, although study participants were significantly younger (P=.003). The 64 patients randomly assigned to angioplasty had baseline characteristics similar to those of 61 patients randomly assigned to surgery. Cognitive function scores were not significantly different between angioplasty or surgery patients in an intention-to-treat analysis (P=.57). There also was no difference in cognitive function scores when the data were analyzed according to whether the patient had ever undergone bypass surgery (P=.59).

CONCLUSIONS

Long-term cognitive function is similar after coronary bypass surgery and coronary angioplasty in the majority of patients.

Prostate-specific antigen doubling times in patients who have failed radical prostatectomy: correlation with histologic characteristics of the primary cancer

OBJECTIVES

This study sought to characterize the postoperative prostate-specific antigen (PSA) doubling time and time to biochemical recurrence in patients who have failed radical prostatectomy.

METHODS

Of 539 consecutive patients who underwent radical prostatectomy between 1984 and 1992, postoperative PSA levels in 80 initially became undetectable (less than 0.07 ng/mL) before eventually increasing, as evidenced by rising PSA levels above the residual cancer detection limit of the Tosoh AIA-600 immunoassay run in the ultrasensitive mode (i.e., 0.07 ng/mL or higher). The PSA doubling time and time to biochemical recurrence were calculated for each of the 80 patients and were correlated with the histopathologic variables from the operative specimen.

RESULTS

Postoperative PSA doubling times were predicted by the extent of capsular penetration, percent Gleason grade 4 or 5, lymph node involvement, and tumor volume on univariate analysis and by capsular penetration, percent Gleason grade 4 or 5, lymph node involvement, and patient age on multivariate analysis. Times to recurrence were predicted by the presence of positive margins and percent Gleason grade 4 or 5 in both univariate and multivariate regression models. The PSA doubling time did not correlate with recurrence time. The median PSA doubling time for all patients was 284 days, and the median time to recurrence was 648 days.

CONCLUSIONS

These results demonstrate that PSA doubling time and recurrence time are indicative of different biologic characteristics of recurrent prostate cancer: Doubling time appears to represent the aggressiveness of the original prostate cancer, whereas time to recurrence reflects the extent of residual postoperative disease. This information should aid in the selection of men who need greater vigilance during postoperative surveillance.

Medical care costs and quality of life after randomization to coronary angioplasty or coronary bypass surgery. Bypass Angioplasty Revascularization Investigation (BARI) Investigators

BACKGROUND

Randomized trials comparing coronary angioplasty with bypass surgery in patients with multivessel coronary disease have shown no significant differences in overall rates of death and myocardial infarction. We compared quality of life, employment, and medical care costs during five years of follow-up among patients treated with angioplasty or bypass surgery.

METHODS

A total of 934 of the 1829 patients enrolled in the randomized Bypass Angioplasty Revascularization Investigation participated in this study. Detailed data on quality of life were collected annually, and economic data were collected quarterly.

RESULTS

During the first three years of follow-up, functional-status scores on the Duke Activity Status Index, which measures the ability to perform common activities of daily living, improved more in patients assigned to surgery than in those assigned to angioplasty (P<0.05). Other measures of quality of life improved equally in both groups throughout the follow-up period. Patients in the angioplasty group returned to work five weeks sooner than did patients in the surgery group (P<0.001). The initial mean cost of angioplasty was 65 percent that of surgery ($21,113 vs. $32,347, P<0.001), but after five years the total medical cost of angioplasty was 95 percent that of surgery ($56,225 vs. $58,889), a difference of $2,664 (P = 0.047). The five-year cost of angioplasty was significantly lower than that of surgery among patients with two-vessel disease ($52,930 vs. $58,498, P<0.05), but not among patients with three-vessel disease ($60,918 vs. $59,430). After five years of follow-up, surgery had an overall cost-effectiveness ratio of $26,117 per year of life added, but unacceptable ratios of $100,000 or more per year of life added could not be excluded (P=0.13). Surgery appeared particularly cost effective in treating diabetic patients because of their significantly improved survival.

CONCLUSIONS

In patients with multivessel coronary disease, coronary-artery bypass surgery is associated with a better quality of life for three years than coronary angioplasty, after the initial morbidity caused by the procedure. Coronary angioplasty has a lower five-year cost than bypass surgery only in patients with two-vessel coronary disease.

Risk factors for the development of obliterative bronchiolitis after lung transplantation

BACKGROUND

Acute rejection has emerged as an important risk factor for obliterative bronchiolitis after lung transplantation. We performed a multivariate analysis to assess the impact of additional variables.

METHODS

Seventy-four recipients (48 heart-lung, 18 single-lung, and 8 bilateral-lung recipients) who survived longer than 90 days and underwent transplantation more than 15 months before data analysis were included in this study. Several variables were entered into a Cox regression analysis to determine their association with the development of bronchiolitis obliterans syndrome.

RESULTS

Bronchiolitis obliterans syndrome developed in 48 (65%) of 74 patients. Significant correlations were detected for acute rejection score, defined as the sum of pathologic grades of each separate acute rejection episode (p = 0.0004, likelihood ratio test value = 12.4) and for lymphocytic bronchiolitis (p = 0.03). In a bivariate model, episodes of organizing pneumonia and bacterial or fungal pneumonia significantly increased the likelihood ratio test value of the acute rejection score. The addition of the cytomegalovirus infection score, reflecting the frequency and severity of infection, to the combination of the acute rejection score and episodes of bacterial or fungal pneumonia resulted in a further significant increase in the likelihood ratio test value. Significant risk factors for moderate to severe stages of airflow limitation were at least one episode of acute rejection of grade > or = 2, younger recipient age, and any acute rejection episode 180 days or longer after transplantation.

CONCLUSIONS

Increasing frequency and severity of acute rejection episodes are strongly associated with the development of bronchiolitis obliterans syndrome. Lymphocytic bronchiolitis appeared to be significant by univariate analysis, but in a two-risk factor model, it did not augment the influence of acute rejection. Organizing pneumonia, bacterial or fungal pneumonia, and increasing severity and frequency of cytomegalovirus infections potentiate the effect of acute rejection. Late episodes of acute rejection and younger recipient age increase the risk for development of advanced disease.

Randomised, controlled trial of efficacy of midwife-managed care

BACKGROUND

Midwife-managed programmes of care are being widely implemented although there has been little investigation of their efficacy. We have compared midwife-managed care with shared care (ie, care divided among midwives, hospital doctors, and general practitioners) in terms of clinical efficacy and women's satisfaction.

METHODS

We carried out a randomised controlled trial of 1299 pregnant women who had no adverse characteristics at booking (consent rate 81.9%). 648 women were assigned midwife-managed care and 651 shared care. The research hypothesis was that compared with shared care, midwife-managed care would produce fewer interventions, similar (or more favourable) outcomes, similar complications, and greater satisfaction with care. Data were collected by retrospective review of case records and self-report questionnaires. Analysis was by intention to treat.

FINDINGS

Interventions were similar in the two groups or lower with midwife-managed care. For example, women in the midwife-managed group were less likely than women in shared care to have induction of labour (146 [23.9%] vs 199 [33.3%]; 95% CI for difference 4.4-14.5). Women in the midwife-managed group were more likely to have an intact perineum and less likely to have had an episiotomy (p = 0.02), with no significant difference in perineal tears. Complication rates were similar. Overall, 32.8% of women were permanently transferred from midwife-managed care (28.7% for clinical reasons, 3.7% for non-clinical reasons). Women in both groups reported satisfaction with their care but the midwife-managed group were significantly more satisfied with their antenatal (difference in mean scores 0.48 [95% CI 0.41-0.55]), intrapartum (0.28 [0.18-0.37]), hospital-based postnatal care (0.57 [0.45-0.70]), and home-based postnatal care (0.33 [0.25-0.42]).

INTERPRETATION

We conclude that midwife-managed care for healthy women, integrated within existing services, is clinically effective and enhances women's satisfaction with maternity care.

Initial functional and economic status of patients with multivessel coronary artery disease randomized in the Bypass Angioplasty Revascularization Investigation (BARI)

Randomized trials of coronary angioplasty and bypass surgery have hypothesized that these procedures will have equivalent long-term rates of death and myocardial infarction. Functional status, quality of life, employment, and healthcare cost will therefore be critical measures of the efficacy of these alternative revascularization procedures. Patients at 7 sites in the Bypass Angioplasty Revascularization Investigation (BARI) were enrolled in an ancillary Study of Economics and Quality of Life (SEQOL). Physical function was assessed by the Duke Activity Status Index and emotional status by the Mental Health Inventory. Employment patterns and health care utilization were also measured at study entry and at 3-month intervals in follow-up. The 934 patients enrolled in SEQOL were similar to the 895 remaining BARI randomized patients. Most patients (63%) aged < or = 64 years were working, and almost all working patients (96%) intended to return to work. Patients aged > or = 65 years had lower household incomes but better health insurance coverage. Overall health ratings were significantly correlated with both physical and emotional status (p < 0.001). Patients enrolled in SEQOL are representative of the overall BARI population. Data collected in SEQOL will provide a detailed picture of the physical, emotional, and economic well-being after coronary angioplasty and bypass surgery.

A preliminary study of diltiazem in the prevention of coronary artery disease in heart-transplant recipients

BACKGROUND

Accelerated coronary artery disease is a major cause of late morbidity and mortality among heart-transplant recipients. Because calcium-channel blockers can suppress diet-induced atherosclerosis in laboratory animals, we assessed the efficacy of diltiazem in preventing coronary artery disease in transplanted hearts.

METHODS

Consecutive eligible cardiac-transplant recipients were randomly assigned to receive diltiazem (n = 52) or no calcium-channel blocker (n = 54). Coronary angiograms obtained early after cardiac transplantation and annually thereafter were used for the visual assessment of the extent of coronary artery disease. The average diameters of identical coronary artery segments were measured on the angiograms obtained at base line and at the first and second follow-up examinations.

RESULTS

In the 57 patients who had all three angiograms, the average coronary artery diameter (+/- SD) 0.27 decreased in the group that received no calcium-channel blocker from 2.41 +/- 0.27 mm at base line to 2.19 +/- 0.28 mm at one year, and to 2.22 +/- 0.26 mm at two years (P < 0.001 for both years). The average diameter in the diltiazem group changed little from the base-line value of 2.32 +/- 0.22 mm (2.32 +/- 0.27 mm at one year and 2.36 +/- 0.22 mm at two years). The average change in the diameter of the segment differed significantly between the two treatment groups (P < 0.001), and the estimated effect of treatment changed only negligibly after adjustment for other relevant clinical variables. New angiographic evidence of coronary artery disease developed in 14 patients not given calcium-channel blockers, as compared with 5 diltiazem-treated patients (P = 0.082). Coronary stenoses greater than 50 percent of the luminal diameter developed in seven patients not given calcium-channel blockers, as compared with two patients given diltiazem; death due to coronary artery disease or retransplantation occurred in five patients in the group that did not receive calcium-channel blockers and none of those who received diltiazem.

CONCLUSIONS

Our preliminary results suggest that diltiazem can prevent the usual reduction in the diameter of the coronary artery in cardiac-transplant recipients, but further follow-up will be required to determine whether diltiazem can decrease the long-term incidence of symptomatic coronary artery disease.

Clinical signs, laboratory changes and toxicokinetics of brodifacoum in the horse

Six horses gavaged with a commercial brodifacoum (BDF)-containing bait (Talone) at a dosage of 0.125 mg of BDF/kg of body weight showed weight loss, severe hypocoagulability and hemogram alterations. Four of the horses became depressed and anorectic; one required vitamin K1 therapy. Increases in clotting times were observed at 24 h in the partial thromboplastin time (PTT) followed by the thrombotest (TBT) and one-stage prothrombin time (PT) at 48 h. Elevated mean PTT, PT and TBT were observed from days 4 to 8 (p less than 0.05) with levels returning to pretreatment levels by day 12. Maximum prolongation was a fourfold increase in PTT (day 4), a 2.5-fold increase in TBT (day 6) and a twofold increase in PT (day 6). Thrombin clotting times remained unchanged. In two horses prolongation in clotting time did not normalize until day 23. The mean hematocrit (0.38 +/- 0.01 L/L) was decreased (p less than 0.05) from day 8 (0.33 +/- 0.02 L/L) to day 14 (0.33 +/- 0.01 L/L). The hemoglobin concentration and erythrocyte numbers were decreased (p less than 0.05) from day 6 (20.1%, 17.6% respectively) to day 14 (22%, 20% respectively). Platelet counts decreased on day 6 (17.2%) to nine (14.6%). No other significant changes were observed in routine hematological and serum biochemical parameters. Peak plasma concentrations of BDF occurred 2 to 3 h after oral administration; two horses had detectable levels of BDF at nine days. Pharmacokinetic evaluation indicated that BDF has a half-life of 1.22 +/- 0.22 days, a body clearance of 1073.1 +/- 53.21 mL/kg/day, a volume of distribution of 1853.7 +/- 26.41 ng-day/mL and closely approximates a one-compartment model in the elimination phase.(ABSTRACT TRUNCATED AT 250 WORDS)

Congenital toxoplasmosis in Abyssinian cats

Two of three litter-mate kittens born to an Abyssinian cat died of acute toxoplasmosis. Toxoplasma gondii was found in histologic sections of both kittens and this was confirmed by immunoperoxidase staining.

Reproductive patterns of pedigree cats

A survey of Brisbane catteries was carried out to investigate reproductive patterns of pedigree cats. Eighteen breeders supplied data on 751 litters with a total of 3171 kittens covering the Persian, Chinchilla, Siamese, Burmese and Abyssinian breeds. The overall sex ratio at birth was 100 males to 92 females. There was a significant seasonal effect on sex ratio with litters conceived during the wet season (September to February) producing more males than expected and litters conceived during the dry season producing more females than expected. Litter size and breed had no significant effect on the sex ratio. The average litter size varied with the breed with the most prolific being the Burmese (5.0) then the Siamese (4.5), Persian (3.9), Abyssinian (3.5) and Chinchilla (2.8). The average litter size was smaller for the first litter than for the subsequent 3 litters. The maximum average litter size was reached at 6 years with only a moderate decline thereafter. There was a seasonal fluctuation in births with the greatest numbers being born in spring and the least in late autumn. Longhair cats showed a more marked seasonal distribution of births than the shorthairs which reproduced for most of the year, particularly the Burmese breed.

An aetiological study of 290 XXY males, with special reference to the role of paternal age

Data on 290 non-mosaic 47,XXY males have been analysed for possible associations with parental ages at birth, season of birth, sex ratio among sibs, and twinning. Comparison with matched population controls revealed a highly significant association with parental age, which was fully explained by dependence on maternal age and maternal age alone. The maternal age effect was determined with greater precision than in an earlier study of the same material, in which siblings were used as controls, and was estimated to result in an increased risk of between 5% and 10% per annum (p.a.). The estimated independent effect of paternal age, after fitting maternal age, was marginally (but not significantly) negative, and excluded an increased risk in excess of 3% p.a. Paternal age therefore appears to have little if any independent significance in the aetiology of 47,XXY. After correcting for seasonal variations in the population birth rate and smoothing, there was a peak of XXY births in March and a trough in November. Though not statistically significant, the pattern resembled that reported in previous studies, and was similar for both younger and older mothers. The twinning rate for both the XXYs and their sibs, and the sex ratio among the latter, were close to the corresponding population values.

Electroejaculation in the domestic cat

A method of electroejaculation for tomcats is described. Normal sperm counts in 4 cats ranged from 6 to 13 X 10(6)/ejaculate. There was a great deal of variation between collections from the same cat indicating the necessity for at least 5 collections when assessing the fertility of a tomcat. Sperm counts were higher in the latter half of the year, at the time of increased sexual activity for cats in the Brisbane area. The volume of semen collected by electroejaculation increased in direct proportion to the length of electrical stimulation, hence, volume is not a reliable criterion for the appraisal of semen. However, results have indicated that semen volume tends to increase from July to December, thus indicating increased accessory gland activity during the breeding season. As this procedure does not cause any apparent discomfort or harmful effects there seems no reason to assume that it could not be used routinely on stud cats.

Enhanced incorporation of exogenous arachidonic acid into phosphatidylinositol and other phospholipids during the early stages of thrombin-induced aggregation in gerbil platelets

The degradation of platelet phospholipids via phospholipase activity is known to occur during thrombin-induced platelet aggregation. Both phosphatidylinositol and phosphatidylcholine are considered to be sources of the released arachidonic acid which becomes a substrate for prostaglandin and thromboxane A2 formation. In this work, the effect of thrombin on the incorporation of exogenous arachidonic acid into platelet membrane phospholipids was studied. Suspensions of gerbil platelets were incubated in aggregometer cuvettes with [14C] arachidonic acid in the absence or presence of thrombin, and product formation was monitored by thin layer chromatography and scintillation counting. Within 30 sec, the entry of arachidonic acid into phosphatidylinositol was increased by 165% in thrombin-stimulated platelets over controls. Under identical conditions, the incorporation into phosphatidylcholine was increased by only 57%. These results suggest that the incorporation of exogenous arachidonic acid via lysophosphatidylinositol and lysophosphatidylcholine acyltransferase activities may be intimately associated with thrombin-induced platelet aggregation in the gerbil.

The metabolism of the anti-inflammatory drug eterylate in rat, dog and man

Oral doses of 14C-eterylate were well absorbed by rat and man and excreted mainly in the urine (94% dose by rat in three days and 91% by man in five days). Oral doses to dogs were excreted in similar proportions in both the urine and faeces, although faecal 14C was probably derived in part, from biliary-excreted material. Peak plasma 14C and drug concn. were generally reached between one and three hours after oral doses. In humans, only two metabolites, salicylic acid and 4-acetamido-phenoxyacetic acid, were detected in plasma. The latter was cleared more rapidly than the former and hence plasma salicyclate concn. reached a peak (10.9 and 19.8 micrograms/ml in Subjects 1 and 2, respectively) and initially declined with a half-life of about two-three hours. Plasma 4-acetamidophenoxyacetic acid concn. reached a peak (4.3, 10.0 micrograms/ml, respectively) and declined with a half-life of about one hour. Tissue concn. of 14C were generally greater in dogs than in rats. Highest conc. occurred at three hours in dogs and at one hour in rats. Apart from those in the liver and kidneys, tissue concn. were lower than those in the corresponding plasma. Unchanged drug was not detected in urine or plasma of any species and was rapidly metabolized in human plasma. The major 14C components in human urine were identified as salicyluric acid and 4-acetamidophenoxyacetic acid; minor metabolites were salicylic acid, gentisic acid and paracetamol. These metabolites were also detected in rat urine albeit in different proportions to those in human urine. Dog urine contained less of these metabolites and a major proportion of the 14C was associated with relatively non-polar components. Although salicylic acid and 4-acetamidophenoxyacetic acid were the only major circulating metabolites in man and rat, dog plasma also contained the non-polar urine metabolites.