Cerebral infarction and myocardial fibrosis in a white-handed gibbon (Hylobates lar).

A white-handed gibbon (Hylobates lar) lost the use of its right hand. Complete blood count, serum chemistry profile, electrocardiographic findings, blood pressure, and radiographic work-up were normal, but the gibbon died 2 days later. The gibbon was serologically positive for herpes simplex I and Epstein-Barr virus. Necropsy and histopathology showed acute infarction of the right cerebrum and multifocal to coalescing severe myocardial fibrosis.

Thymoma in two ferrets.

A cranial mediastinal mass was observed radiographically in two 5-year-old adult male ferrets (Mustela putorius furo), both with histories of chronic episodic vomiting, dyspnea, and lethargy. Malignant lymphoma, a common neoplasm observed in ferrets, was considered the most likely diagnosis. Cardiomegaly and splenomegaly were also present. Histologically both mediastinal masses were composed of thymic epithelial cells and small lymphocytes, establishing a diagnosis of thymoma. Thymoma should now be included in the differential diagnosis of a cranial mediastinal mass in ferrets.

Wound cultures: what, when and how.

Collecting wound cultures is a very controversial issue at this time when cost containment is at the forefront of healthcare providers' minds. It is also controversial in this time of Methicillin Resistant Staphylococcus-aureus (MRSA) becoming more common and very difficult to manage in acute and long term care facilities. While the basics of culturing may have not changed, the decision to culture or not, and knowing what, when and how to culture, are of vital importance in the treatment and quality of care for the patient, staff and others. The purpose of this article is to present the implications for culturing a wound and the proper procedure for collecting the specimen and planting the organism. In this discussion of wound culturing, the authors will provide guidelines to accurately interpret the results to accommodate proper treatment in a cost-effective manner.

The effects of dietary levels of inorganic phosphorus, calcium and cholecalciferol on the digestibility of phytate-P by the chick.

Male broiler chicks (1-d-old; Ross one) were given either a control diet containing recommended levels of phosphorus, calcium and cholecalciferol or experimental diets low in P and with variable levels of Ca (normal and low) and cholecalciferol (normal or high). The low-P diet with normal levels of Ca and cholecalciferol induced a hypophosphataemia and a hypercalcaemia which was reflected in reduced tibia length and weight and in reduced Ca, P and magnesium contents of tibia. The phytate digestibility remained normal while the retention of P and Ca fell significantly. The lowering of Ca alone elevated phytate digestibility and restored P and Ca retention. The hypercalcaemia and hypophosphataemia remained and tibia mineralization remained impaired. The raising of cholecalciferol alone dramatically increased phytate digestibility and the retention of Ca and P. While this remedied the hypercalcaemia, the hypophosphataemia persisted as did the diminution of tibia weight. The simultaneous lowering of dietary Ca and elevation of cholecalciferol on low-P diets restored all variables to the levels for the control diet. Circulating levels of 1,25-dihydroxycholecalciferol were significantly elevated by low-P diets, more so with high cholecalciferol intakes. However, Ca did not influence 1,25-dihydroxycholecalciferol levels in plasma.

Effects of estrone and estradiol-17 beta on 25-hydroxycholecalciferol hydroxylase activities in female Japanese quail.

Equimolar amounts of estrone and estradiol-17 beta injected into sexually immature female Japanese quail caused comparable increases and decreases in the renal activity of 25-hydroxycholecalciferol (25HCC) 1 alpha-hydroxylase and 25-hydroxycholecalciferol 24-hydroxylase, respectively. Peak activity of the former enzyme was induced by both estrogens within 6 hr and had declined by 24 hr. Plasma concentrations of estrone and estradiol following the injection were maximal within 3-6 hr of injecting the steroid i.m. Following [3H]estradiol injection, 25% of the radioactivity was located with estrone in the plasma following separation by TLC. Conversely, following [3H]estrone injection 30% of the radioactivity in plasma was located with estradiol. Thus, both estrone and estradiol may have physiological effects in quail, which in part may be due to their in vivo interconversion. Evidence that prolactin may be mediating the estrogenic stimulation of the 25HCC 1 alpha-hydroxylase is also presented.

Changes in plasma concentrations of reproductive steroids in female Japanese quail (Coturnix coturnix japonica) raised on long or short photoperiods.

Plasma concentrations of progesterone, testosterone, estradiol, and estrone were measured by radioimmunoassay in female Japanese quail 22 to 70 days of age. The birds were raised on long (16 hr light per day) or short (8 hr light per day) photoperiods. Only the birds raised on the long photoperiod layed eggs, starting between 42 and 49 days of age. The concentration of each reproductive steroid increased between 28 and 35 days of age, but the increases were more substantial in the birds raised on long days than in the birds raised on short days. Changes in plasma progesterone and testosterone concentrations showed similar trends: the concentrations increased before the onset of lay and were maintained at a high level in the laying birds. In contrast, plasma concentrations of estradiol and estrone increased to a peak at 35-42 days and declined once egg laying became established. The short-day birds also showed increased plasma estrogen levels, maximal at 35-42 days, with estrone being at a higher concentration than estradiol. The increases in plasma steroid levels occurred during the period of rapid growth of the ovaries and oviducts in the long-day birds, although in the short-day birds the growth of these organs was much less substantial.

The effect of age on egg production in the domestic hen.

The effect of age on egg production was investigated in the domestic fowl. The rate of egg production was reduced with increasing age and the incidence of thin-shelled and cracked eggs was markedly increased. Older hens which remained in lay produced fewer but larger eggs than the younger birds. The ovaries of these two groups of hens were of similar appearance but the largest preovulatory follicle and the oviduct were significantly heavier in the older birds. No differences in the circulating levels of progesterone or estradiol were apparent between the young and old birds but the activity of the renal 25-hydroxycholecalciferol 1 alpha-hydroxylase was found to be significantly reduced with age. Circulating levels of total and ionized calcium were very similar in the young and old laying birds, plasma ionized calcium levels being markedly depressed during egg shell calcification in both groups. The decreased rate of ovulation in the older birds and the increase with age in the size of the follicles ovulated is thought to be associated with a reduced rate of recruitment of follicles for rapid growth followed by a prolonged period of follicular growth and development. The poor calcification of egg shell in old birds would appear to be due to some dysfunction of the shell gland, possibly associated with reduced synthesis of 1,25-dihydroxycholecalciferol by the kidney. The maintenance of plasma ionized calcium concentrations does not appear to be of primary importance in this respect.

Changes in the concentrations of parathyroid hormone and ionic calcium in the plasma of laying hens during the egg cycle in relation to dietary deficiencies of calcium and vitamin D.

The concentrations of biologically active parathyroid hormone (PTH) and ionic calcium (Ca2+) were determined in the plasma of control and calcium-deficient laying hens during the egg cycle. The same measurements were made in hens that had ceased laying because of a deficiency of vitamin D and in normal hens during pauses in egg production. Changes in the concentration of Ca2+ during the egg cycle followed the same pattern and were of the same magnitude in the control and calcium-deficient birds: mean levels were high when egg shell calcification was not occurring and they were at least 0.10 mmol/litre lower during active shell formation. There was a reciprocal relationship between the concentrations of PTH and Ca2+; thus, PTH values were high during shell calcification and low before shell formation began and after oviposition. Mean concentrations of PTH in the birds given the low-calcium diet were more than twice as high as in the control birds both during shell formation at 0700 hr (12.85 and 5.95 pg/ml, respectively) and after oviposition at 1600 hr (4.25 and 0.55 pg/ml, respectively). The results of these experiments provide direct evidence that the mobilization of skeletal calcium for egg shell formation is under parathyroid control. In the non-shell-forming control and vitamin D-deficient birds there were no significant changes over the 27-hr sampling period in either PTH or ionic calcium.(ABSTRACT TRUNCATED AT 250 WORDS)

A comparative study of phytate hydrolysis in the gastrointestinal tract of the golden hamster (Mesocricetus auratus) and the laboratory rat.

The role of bacterial, dietary and intestinal phytases (EC 3.1.3.8) in the hydrolysis of phytate was investigated in the golden hamster and rat by assaying phytase in the small intestine and by measuring the disappearance of phytate from the stomach and large intestine, using chromium oxide as an insoluble solid-phase marker. It was confirmed that an active phytase was present in the proximal third of the small intestine of the rat but the enzyme was undetectable in the hamster. Extensive bacterial breakdown of phytate occurred in the pregastric pouch and true stomach of the hamster with both phytase-containing and phytase-free diets, with phytate digestibilities in the true stomach ranging from 0.69-0.90, confirming that the hamster can be regarded as a pseudo-ruminant. With a phytase-free diet, the digestibility of phytate in the stomach of the rat was very low (0.05) but with a wheat-based diet substantial breakdown of phytate occurred (digestibility up to 0.49), presumably under the influence of the cereal phytase. Intestinal phytase did not appear to be of great significance in the rat but some further hydrolysis of the residual phytate probably occurred in the large intestine of both species by bacterial phytase.

Reversible hypercholesterolaemia produced by cholesterol-free fish meal protein diets.

Groups of rabbits were fed isonitrogenous diets containing 30% soya, milk or whitefish meal protein and at least 130 g/kg of added fat for 1 year. Mean serum cholesterol values in fish meal animals (13.4 +/- 2.4 mmol/l) were substantially greater than for soya (3.0 +/- 0.2 mmol/l) or milk (4.6 +/- 0.7 mmol/l). Fish meal rabbits developed extensive aortic atherosclerosis (c. 70% surface involvement) which histologically showed both fibrous and foam cell intimal thickening and destruction and calcification of medial elastic tissue. In a second experiment fish meal was given with either saturated (coconut oil) or unsaturated (maize oil) fat. A similar degree of hypercholesterolaemia developed in each group and was rapidly reversed when a soya protein-low fat diet was substituted. This model may therefore be of value in studies of the progression and regression of experimental atherosclerosis.

Immune tolerance and atherosclerosis in rabbits. Effect of high-fat and cholesterol-supplemented diets.

Breeding rabbits were fed diets supplemented with 5% milk or soya protein for 1 month before conception and throughout pregnancy and lactation. Four groups of 5 or 6 of their offspring were given high-energy isonitrogenous diets containing either 30% soya or milk protein. Half of the animals from each litter received the same protein as their dams; the remainder were fed the alternative (i.e. dams soya; offspring milk, and vice versa). 0.75% cholesterol was added to the diets between 30 and 120 days after weaning. Animals given the same protein as their dams formed substantially lower amounts of food antigen-specific antibody than rabbits fed a novel protein at weaning but the extent of aortic atherosclerosis was similar in all groups. In a second experiment groups of 5-8 weanling rabbits were fed a cholesterol-free diet containing 30% soya and 17% saturated fat for 1 year. Animals in group 1 were bred from dams given soya but those in groups 2 and 3 were derived from a colony fed a soya-free diet. Rabbits in group 3 were immunised by repeated parenteral injections of soya protein and developed high levels of antisoya antibodies. Group 1 and 2 animals were injected with saline only but antisoya antibodies were substantially higher in animals derived from the soya-free breeding colony. Although serum cholesterol and triglyceride levels were similar in all groups, animals from dams fed soya (group 1) had significantly less aortic atherosclerosis (10% involvement of ascending aorta) than those reared from a colony fed a soya-free diet (group 2; 32%). Parenteral immunization with soya protein (group 3) was not associated with significantly increased atherosclerosis (37%). These findings indicate that perinatal exposure to dietary antigen in rabbits may be important in modulating the systemic immune reaction to food antigens. The magnitude of this systemic response is unlikely to alter the nature or distribution of cholesterol-induced atherosclerosis but may have an important influence on the development of aortic disease produced by prolonged feeding of high-fat, cholesterol-free diets.

The effect of polyunsaturated fatty acids on the n-3 and n-6 series on platelet aggregation and platelet and aortic fatty acid composition in rabbits.

Four groups of 6 New Zealand white rabbits were fed for 60 days on a commercial rabbit diet supplemented (60 g/kg) with 1 of 4 sources of fat: corn oil, linseed oil and fish oil, which respectively provided rich sources of linoleic acid (C18:2, n-6), alpha-linolenic acid (C18:3, n-3) and eicosapentaenoic acid (C20:5, n-3), and coconut oil, low in all polyunsaturated fatty acids (PUFA). Platelet-rich plasma was prepared and aggregation induced by ADP (final concentration 0.29-74.3 microM), collagen (2.5-20 micrograms/400 microliters, final concentration) and 2.5 U bovine thrombin, and recorded with a Peyton aggregometer. Platelet aggregation induced by both thrombin and collagen was significantly lower with either n-3 PUFA (fish or linseed oil) than with corn oil (n-6 PUFA) or the low PUFA coconut oil. ADP-induced platelet aggregation was significantly reduced only in animals fed fish-oil. Changes in platelet aggregation were accompanied by increased platelet lipid content of C20:5, n-3 and decreased content of C20:4, n-6, with little change in platelet total C20 fatty acids. Platelet levels of C20:5, n-3 were significantly increased with both the preformed C20:5, n-3 and its precursor C18:3, n-3 in the diet. However, aortic lipid accumulation of C20:5 only occurred with rabbits fed on fish oil. It was concluded that, for collagen and thrombin induced aggregation, C18:3, n-3 and C20:5, n-3 were equally antiaggregatory in rabbits. The implications of this in community nutrition programmes are discussed.

The effect of dietary protein source and saponins on serum lipids and the excretion of bile acids and neutral sterols in rabbits.

1. Four groups of six rabbits were given purified diets in which the dietary variables were protein source (isolated soya-bean protein or cow's-milk protein) with or without saponin supplementation (10 g/kg). 2. Rabbits given soya-based diets showed significantly lower serum concentrations of triglyceride and cholesterol (P less than 0.01). The latter changes were confined to the cholesterol fractions of beta-lipoproteins. 3. These changes in serum cholesterol were associated with a significantly increased excretion of acid and neutral sterols in animals given soya-bean protein. 4. There was no evidence to suggest that the effect of dietary protein source on serum lipids and the excretion of total and individual sterols was influenced by saponin supplementation. 5. These results do not support the hypothesis that the hypocholesterolaemia associated with plant proteins is due to the presence of saponins.

Immune tolerance produced by pre- and postnatal exposure to dietary antigens.

Circulating food antibody levels were measured by ELISA in groups of weanling rabbits fed 320 g/kg diet soya or milk protein. Soya-fed rabbits of milk-fed mothers (and vice versa) showed at least tenfold increase in antibody levels within 3-4 weeks. In contrast, animals fed the same diet as their dams had received in pregnancy and the postnatal period showed little change in antibody levels. These results indicate that contact with a dietary antigen before birth and during the suckling period is important in the induction of tolerance to food proteins in young animals.

Antibodies to heated milk protein in coronary heart disease.

Coronary arteriography was used to identify 37 patients with triple coronary vessel disease and 37 patients with no evidence of occlusive coronary atheroma. Two techniques were used to analyse serum levels of antibodies to heated milk protein, passive haemagglutination and enzyme-linked immunosorbent assay. No significant differences in these antibodies were observed between triple and zero vessel disease patients. Even after applying ECG evidence of myocardial infarction as a further criterion for classifying patients, no evidence was obtained to support the hypothesis that serum antibodies to heated milk protein are elevated in coronary heart disease.