Studies on effects of lactose on experimental Trypanosoma vivax infection in Zebu cattle. 1. Plasma kinetics of intravenously administered lactose at onset of infection and pathology

Lactose in normal saline was administered intravenously to a group of Zebu cattle infected with Trypanosoma vivax to determine the blood plasma kinetics at onset of an experimental infection and its ability to protect tissues against damage as part of preliminary studies to determine its suitability for use in the treatment of trypanosomosis. Significantly (P < 0.01) higher lactose concentrations were observed in the T. vivax-infected bulls at 30 min and 1 h (P < 0.05) post-infection (p.i.) and by 4 h p.i. the plasma lactose remained above the level prior to infusion, after which it fell slightly below the pre-infusion level in the uninfected group. Calculated pharmacokinetic parameters revealed delayed excretion of lactose in the T. vivax-infected group soon after infection. The total body clearance (Cl(B)) was significantly (P < 0.05) reduced. The biological half-life (t1/2), elimination rate constant (k(el)) and apparent volume of distribution (V(d)) were relatively decreased (P > 0.05) as a result of the T. vivax infection. Retention of lactose in the plasma was attributed to decreased plasma clearance. It is suggested that the presence of trypanosomes in circulation rather than organic lesions could have been responsible for the delay observed in the excretion of lactose. At 12 weeks p.i., when the experiment was terminated, the group infected and given lactose infusion (despite higher parasitaemia) had no gross or histopathological lesions in the brain, spleen, lymph nodes, heart, kidneys, liver and testes. However, the group infected but not infused with lactose were emaciated, had pale mucosae, watery blood, general muscular atrophy, serous atrophy of coronary fat and other adipose tissue, hepatomegaly, splenomegaly, swollen and oedematous lymph nodes, all of which are suggestive of trypanosomosis. Histopathological lesions included narrowing of Bowman's space and hypercellularity of glomerular tufts in the kidneys with the mean glomerular tuft nuclear indices (GTNs) in the group significantly higher (P < 0.01) than the mean GTNs of the lactose-infused and control bulls. Degenerative changes occurred in the myocardium, spleen, testes and epididymides. The tesicular and epididymal lesions are indicative of male reproductive dysfunction.     

Estimation of the total surface area in Indian elephants (Elephas maximus indicus)

Twenty-four adult Indian elephants (Elephas maximus indicus) of both sexes and different ages and weights, belonging to the Temple Devaswoms, the Forest Department of the Government of Kerala and the Gemini Circus formed the experimental subjects from which formulae were derived to predict the total surface area from either body measurements or areas of individual regions. Several models, using the parameters studied either singly or in combination, were tried independently for males and females and also for adults irrespective of sex. The best prediction of total surface area (S) in m² was obtained for adults irrespective of sex by using the two parameters, the height at the shoulders (H) in m and forefoot pad circumference (FFC) in m in the formula S=–8.245+6.807H+7.073FFC. No significant improvement in the accuracy of prediction resulted from the use of the independent best fit formulae for males and females. The conventional method of using the exponential of body weight (kg) for predicting suface area was not found to yield an equivalent accuracy in these animals.     

Enzymuria as an index of renal damage in sheep with induced aminoglycoside nephrotoxicosis

Acute nephrotoxicosis was induced in ewes by daily SC administration of gentamicin. Activity of 3 urine enzymes, gamma-glutamyltransferase (GGT), beta-N-acetylglucosaminidase (AGS), and beta-glucuronidase (GRS), were measured during the development of aminoglycoside nephrotoxicosis. Measurements from timed, volume-measured urine samples were performed on days 0, 7, and 8. Measurements from urine samples obtained without volume measurement (spot samples) were performed daily. Urine GGT and AGS activities were high 3 days prior to detection of high serum creatinine concentration and 1.5 days before the appearance of casts in the urine sediment; values consistently remained in the abnormal range until termination of the study. High urine GRS activity was inconsistent and transient; serum GGT activity did not change during the course of the study. Urine GGT and AGS activities expressed as total excretion per unit time and body weight, enzyme activity per unit volume, and as ratio of urine enzyme activity to urine creatinine concentration were strongly correlated. Urine GGT and AGS, but not GRS activities, are suitable indicators of renal tubular cell damage in sheep with aminoglycoside nephrotoxicosis. Urine GGT and AGS activities indicate cellular changes occurring several days prior to the first indications of renal functional change.     

Effect of immunization against somatostatin in the pregnant ewe on growth and endocrine status of the neonatal lamb

Absorption of somatostatin (SRIF) specific antibodies from colostrum of ewes actively immunized against SRIF may improve growth rate of the neonatal lamb by neutralizing the inhibitory effects of SRIF on pituitary and thyroid function. Growth and endocrine parameters in the offspring of SRIF immunized (SI) and control (C) crossbred ewes were examined. Lamb weight was recorded at birth and twice each week to 24 days of age. Blood samples were collected prior to first suckle and twice each week. At 21 to 24 days of age, in separate experiments, lambs were infused with glucose (0.29 g/kg), arginine (0.25 g/kg) or thyrotropin-releasing hormone (TRH; 0.33 microgram/kg). A strong correlation (R = 0.88; P less than .01) was observed between anti-SRIF titre in the ewe at parturition and in the lamb at 3 days of age. No effect on lamb birth weight (SI 4.28 +/- 0.27 kg; C 4.35 +/- 0.23 kg) was observed. At 24 days of age cumulative gain in SI lambs (5.4 +/- 0.32 kg) was greater (P less than .05) than in C lambs (4.5 +/- 0.32 kg). The growth hormone secretory responses to glucose or arginine were not affected by treatment. Plasma IGF-I, plasma thyroxine (T4) and the plasma thyrotropin and T4 responses to TRH were not different between treatments. Plasma triiodothyronine (T3) was higher (P less than .05) in SI (2.46 +/- .10 ng/ml) than in C (2.01 +/- .05 ng/ml) lambs, however, the plasma T3 response to TRH was lower in SI lambs. Plasma glucose (mg/dl) was higher (P less than .05) in SI (118.4 +/- 1.7) than in C (106.0 +/- 4.0) lambs. Plasma insulin was not affected by treatment. Increased plasma T3 and glucose concentrations during SRIF immunoneutralization in the neonate lamb may be important factors contributing to the growth response observed.     

Mechanical Properties of Four Suture Patterns for Transected Equine Tendon Repair

Thirty-six superficial digital flexor tendons from nine fresh equine cadavers were transected and sutured with size 2 monofilament nylon. Nine tendons were repaired with each of four suture patterns: single-locking loop, double-locking loop, triple-locking loop, or three-loop pulley. The times required for application, tensile strengths, resistance to distraction (gap), and modes of failure were analyzed. The mean times required were: single-locking loop, 3 mins, 15 secs; double-locking loop, 4 mins, 15 secs; triple-locking loop, 10 mins, 50 secs; and three-loop pulley, 4 mins. The double-locking loop, triple-locking loop, and three-loop pulley suture patterns were stronger than the single-locking loop. The triple-locking loop and three-loop pulley patterns were close in strength and only the triple-locking loop was stronger than the double-locking loop. The three-loop pulley had the greatest resistance to gap formation and its mode of failure was different from the others. The three-locking loop suture patterns failed by suture breakage but the three-loop pulley failed first by suture pull-out and then by suture breakage.     

Urinary indices of renal function in sheep with induced aminoglycoside nephrotoxicosis

Aminoglycoside nephrotoxicosis (AGNT) was induced in ewes by daily SC administration of gentamicin. Changes in urinary indices of renal function during the development of AGNT are reported. Measurements from timed, volume-measured urine samples were made on days 0, 7, and 8 and included creatinine clearance, total excretion (TE) rates of electrolytes (Na, K, Cl, P) and urine volume. Measurements from free-catch urine samples (without volume measurement) were made daily and included fractional excretion (FE) rate of electrolytes, urine osmolality, and urine-to-serum osmolality and urine-to-serum creatinine ratios. With the onset of AGNT, FE rates of Na, K, Cl, and P- increased many fold above baseline values (200x, 4 to 5x, 6 to 9x, and 70 to 95x, respectively, on days 7 and 8), indicating decreased tubular reabsorption or increased tubular secretion. The increased FE rates were not representative of increases in total electrolyte excretion rates. The total excretion of Na (TENa) was mildly increased, TEK was decreased, TECl was unchanged, and TEP was significantly increased on days 7 and 8. Abnormal urinalysis results, glucosuria, and increased FEP preceded appreciable increase in serum creatinine concentration. Other abnormal urinary indices of renal function coincided with or followed the increase in serum creatinine concentration. Urinary indices may help characterize renal function associated with the disease state, but did not provide early indication of AGNT.     

Anatomy of the orbital fasciae and the third eyelid in dogs

The connective tissue structures commonly referred to as the periorbita, orbital septum, muscular fasciae, and vagina bulbi or collectively, as the orbital fasciae were dissected then illustrated and described. Two sheets (layers) of the periorbita (endorbita) were found in our dogs. The periorbita should be renamed endorbita because of its anatomic relations. The periorbita did not always fuse with the periosteum of frontal and sphenoid bones. Rather, the periorbita and the periosteum were often distinct and separate; only medioventrally did several fibrous bands unite the superficial sheet of the endorbita with the periosteum. Two layers of the endorbita fused with the periosteum of the margin of the bony orbit and with the orbital ligament. The muscular fasciae were divided into 3 layers. The superficial layer extended caudally from the orbital septum, was thick, and was pierced by arteries, veins, and nerves. The middle layer was attached to the sclerocorneal junction and, at the temporal canthus of the eye, was divided into superficial and deep sheets. The deep portion was attached to the lateral angle of the third eyelid, similar to a strong ligament. The deep layer of the muscular fasciae extended caudally from the sclerocorneal junction in intimate contact with recti and oblique muscles of the eyeball. The deep portion of the deep muscular fascia covered the deep surface of all recti muscles and separated them from the retractor bulbi muscle. Intermuscular septa were observed between middle and deep muscular fascia layers.(ABSTRACT TRUNCATED AT 250 WORDS)     

Follicle characteristics of non-woolly Indian goats

Skin follicular studies of four non-woolly Indian goat breeds are reported. The number of primary follicles ranged from 2 to 14 mm-2 with an overall mean of 6.40 +/- 0.22. Secondary follicles per mm2 ranged from 1 to 23 with an overall mean of 9.48 +/- 0.55. The secondary/primary follicle ratios (S/P) for Black Bengal, Jamnapari, Barbari and Sirohi goats were 1.57 +/- 0.21, 1.15 +/- 0.16, 1.61 +/- 0.21 and 2.04 +/- 0.21, respectively, with an overall mean of 1.59 +/- 0.99. The corresponding values for the total follicles per mm2 for the four breeds were 16.83 +/- 1.39, 15.86 +/- 1.08, 17.66 +/- 1.41 and 13.19 +/- 1.41 with an overall mean of 15.88 +/- 0.66. Per cent primaries were lowest in Sirohi and highest in Jamnapari goats. Analysis of variance revealed significant differences between breeds for the number of primary follicles and S/P ratio. Sex differences and the interaction between breed x sex were not significant for any of the follicle traits studied. On the basis of follicle characteristics the non-woolly short-haired goats offer a reasonable scope for crossing with fibre goats, and Sirohi goats possibly have better skin quality for leather conversion than other goat breeds studied.     

Five field trials on the efficacy of a bovine respiratory syncytial virus vaccine

Five field trials evaluated whether immunization of beef cattle prior to weaning, at weaning, or immediately upon arrival at the feedlot with a commercial bovine respiratory syncytial virus (BRSV) vaccine would reduce subsequent treatment for respiratory disease.

Bovine respiratory syncytial virus vaccination was associated with a significant (p<0.05) reduction in treatment rate in one of three groups of calves immunized prior to weaning (−12%) and in calves immunized upon arrival at the feedlot (−4%).

There was no significant (p>0.05) effect of the BRSV vaccine on treatment rate in calves immunized at weaning, in calves immunized upon arrival at the Saskatoon bull test station, or in yearlings immunized upon arrival at the feedlot.

Although the trend in these field trials was to a sparing effect of the BRSV vaccine, the small reduction in treatment rate may not justify the cost of the vaccination program.