Measuring executive function in sheep (Ovis aries) using visual stimuli in a semi-automated operant system.

BACKGROUND: Cognitive impairment is a distinguishing feature of many neurodegenerative diseases. The intra-dimensional (ID) extra-dimensional (ED) attentional set shift task is part of a clinical battery of tests used to evaluate executive function in Huntington's and Alzheimer's disease patients. The IDED task, however, has not translated well to pre-clinical rodent models of neurological disease. NEW METHOD: The ability to perform executive tasks coupled with a long lifespan makes sheep (Ovis aries) an ideal species for modelling cognitive decline in progressive neurodegenerative conditions. We describe the methodology for testing the performance of sheep in the IDED task using a semi-automated system in which visual stimuli are presented as coloured letters on computer screens. RESULTS: During each stage of IDED testing, all sheep (n = 12) learned successfully to discriminate between different colours and letters. Sheep were quick to learn the rules of acquisition at each stage. They required significantly more trials to reach criterion (p < 0.05) and made more errors (p < 0.05) following stimulus reversal, with the exception of the ED shift (p > 0.05). COMPARISON WITH EXISTING METHOD(S): Previous research shows that sheep can perform IDED set shifting in a walk-through maze using solid objects with two changeable dimensions (colour and shape) as the stimuli. Presenting the stimuli on computer screens provides better validity, greater task flexibility and higher throughput than the walk-through maze. CONCLUSION: All sheep completed each stage of the task, with a range of abilities expected in an outbred population. The IDED task described is ideally suited as a quantifiable and clinically translatable measure of executive function in sheep.

Immune cellular profile of bisphosphonate-related osteonecrosis of the jaw.

OBJECTIVES: Characterize the cell profile and immunostaining of proinflammatory markers in an experimental model of bisphosphonate-related osteonecrosis of the jaw (BRONJ). MATERIALS AND METHODS: Male Wistar rats (n = 6-7) were treated chronically with saline solution or zoledronic acid (ZA) at 0.04, 0.20, and 1.00 mg kg(-1) (1.4 × 10(-7) , 6.9 × 10(-6) , and 3.4 × 10(-5)  mol kg(-1) ), and subsequently, the first left inferior molar was extracted. Were performed counting of viable and empty osteocyte lacunae, viable and apoptotic osteoclasts, polymorphonuclear neutrophil, mast cells (toluidine blue), and the positive presence cells for CD68, tumor necrosis factor-alpha (TNF-α), IL (interleukin)-1ß, inducible nitric oxide synthase (iNOS), nuclear factor-kappa B (NF-kB) and IL-18 binding protein (IL-18 bp). RESULTS: BRONJ was showed in ZA treated with 0.20 and 1.00 mg kg(-1) . There is a dose dependent increase in percentage of empty osteocyte lacunae (P < 0.001) and apoptotic osteoclasts (P < 0.001), counting of total osteoclasts (P = 0.003), polymorphonuclear neutrophil cells (P = 0.009), cytoplasmic-positive cells of CD68 (P < 0.001), TNF-α (P = 0.001), IL-1ß (P = 0.001), iNOS (P < 0.001), NF-kB (P = 0.006), and nuclear-positive cells of NF-kB (P = 0.011). Consequently, there is no difference in mast cells (P = 0.957), and IL-18 bp immunostaining decreases dose dependently (P = 0.005). CONCLUSIONS: BRONJ is characterized by increases in immunostaining for proinflammatory markers and NF-kB and inversely associated with cells exhibiting IL-18 bp.

Diagnostic accuracy of fetal renal pelvis anteroposterior diameter as a predictor of uropathy: a prospective study.

OBJECTIVE: The purpose of this study was to assess the accuracy of prenatal ultrasound measurement of anteroposterior renal pelvis diameter (APD) to discriminate between significant uropathy and idiopathic renal pelvis dilatation. METHODS: One-hundred-and-three neonates who were found to have fetal renal pelvis dilatation, defined as presence of an APD > or = 5 mm, underwent systematic investigation for uropathies and were prospectively followed. An ultrasound scan was performed after the first week of postnatal life and all infants underwent a voiding cystourethrogram. Neonates with an APD larger than 10 mm underwent renal scintigraphy. Ultrasound scans, clinical examination and laboratory reviews were scheduled at 6-month intervals. Receiver-operating characteristics (ROC) curves were constructed to determine the best cut-offs for APD to identify renal units with significant uropathy as well as those requiring surgical intervention. Significant uropathy was defined as the presence of well-established urinary tract abnormalities or when there was abnormal renal scintigraphy. RESULTS: The estimated area under the curve for APD was 0.900 (95% CI, 0.841-0.942) indicating excellent power to discriminate between idiopathic pelvis dilatation and significant uropathy. The sensitivity and specificity for the 7.5 mm cut-off point were 97.9% and 40.6%, respectively. To identify infants who required surgical intervention, the calculated area under the curve was 0.953 (95% CI, 0.908-0.980). CONCLUSION: Our results suggest that measurement of APD is an excellent test to identify fetuses with significant uropathy, as well as those requiring postnatal intervention.

Plasma kinetic behavior in hyperlipidemic subjects of a lipidic microemulsion that binds to low density lipoprotein receptors.

It was previously reported that a protein-free microemulsion (LDE) with structure roughly resembling that of the lipid portion of low density lipoprotein (LDL) was presumably taken up by LDL receptors when injected into the bloodstream. In contact with plasma, LDE acquires apolipoproteins (apo) including apo E that would be the ligand for receptor binding. Currently, apo were associated to LDE by incubation with high density lipoprotein (HDL). LDE-apo uptake by mononuclear cells showed a saturation kinetics, with an apparent K(m) of 13.1 ng protein/mL. LDE-apo is able to displace LDL uptake by mononuclear cells with a Ki of 11.5 ng protein/mL. LDE without apo is, however, unable to displace LDL. The uptake of 14C-HDL is not dislocated by increasing amounts of LDE-apo, indicating that HDL and LDE-apo do not bind to the same receptor sites. In human hyperlipidemias, LDE labeled with 14C-cholesteryl ester behaved kinetically as expected for native LDL. LDE plasma disappearance curve obtained from eight hypercholesterolemic patients was markedly slower than that from 10 control normolipidemic subjects [fractional clearance rate (FCR) = 0.02 +/- 0.01 and 0.12 +/- 0.04 h-1, respectively; P < 0.0001]. On the other hand, in four severely hypertriglyceridemic patients, LDE FCR was not significantly different from the controls (0.07 +/- 0.03 h-1). These results suggest that LDE can be a useful device to study lipoprotein metabolism.

Cytochemical demonstration of lysosomes in skeletal and cardiac striated muscle of fish and turtles.

Skeletal and cardiac striated muscle from two species of fish and turtles were incubated for the cytochemical detection of trimetaphosphatase (TMPase) activity. The results showed that striated muscle from these animals has TMPase-positive structures, which are presumed to be lysosomes.

The effect of venous occlusion on the integration of vascularized cortical bone graft.

The biologic phenomena involved in the healing process of vascularized, cortical bone grafts, vascularized grafts with venous occlusion, and conventional cortical bone grafts, were studied in rabbits. The middle third of the radial diaphysis was the donor site, with a 1.6-cm-long bone cylinder delimited by double transverse osteotomies. The vascularized grafts were raised by extraperiosteal dissection, with preservation of their vascular pedicle, while the conventional grafts were obtained by subperiosteal dissection. The vascularized graft with venous occlusion had its draining vein ligated. Radiologic, scintigraphic, and histologic studies were undertaken at days 7, 15, 30, and 60 postoperatively. Results demonstrated that the vascularized graft healed earlier than the corresponding vascularized graft with venous occlusion and than the conventional graft, respectively. The vascularized graft with venous occlusion suffered some degree of impairment of its irrigation, probably due to retrograde block of the arterial blood flow. It underwent a degree of bone necrosis, followed by resorption and creeping substitution, which delayed its integration. This seemed to be a temporary effect, for it healed earlier than the conventional graft.

Effect of cholinergic stimulation of the medial septal area on the secretory properties of atrial myocardial fibers.

Adult male Wistar rats weighing 240-260 g were implanted with stainless steel guide cannulae into the medial septal area (MSA). Cholinergic stimulation of the MSA increased natriuresis (344.6 +/- 13.8 vs 22.2 +/- 2.1 microEq for the controls), the number of atrial specific granules (61.0 +/- 6.7 vs 43.8 +/- 3.5 granules/100 microns 2 sarcoplasma for the controls), and the number of electron-dense vesicles near the sarcolemma or appearing to undergo exocytotic extrusion (50.0 +/- 2.3 vs 21.4 +/- 5.7 vesicles/100 microns sarcolemma for the controls). It is not yet clear how cholinergic stimulation of the MSA changes the secretory characteristics of atrial myocardial fibers. However, the present study provides evidence that release of an atrial natriuretic factor may be controlled by the central nervous system (CNS). This may occur through the sympathetic and parasympathetic innervation of the heart or through the release of some substance produced by the CNS or produced at another site whose release is controlled by the CNS.

Effect of cholinergic stimulation of the medial septal area on the secretory properties of atrial myocardial fibers

Adult male Wistar rats weighing 240-260 g were implanted with stainless steel guide cannulae into the medial septal area (MSA). Cholinergic stimulation of the MSA increased natriuresis (344.6 + or - 13.8 vs 22.2 + or - 2.1 micronEq for the controls), the number of atrial specific granules (61.0 + or - 6.7 vs 43,8 + or - 3.5 granules/100 micron m**2 sarcoplasma for the controls), and the number of electron-dense vesicles near the sarcolemma or appearing to undergo exocytotic extrusion (50.0 + or - 2.3 vs 21.4 + or - 5.7 vesicles/100 micronm sarcolemma for the controls) It is not yet clear how cholinergic stimulation of the MSA changes the secretory characteristics of atrial myocardial fibers. However, the present study provides evidence that release of an atrial natriuretic factor may be controlled by the central nervous system (CNS). This may occur through the sympathetic and parasympathetic innervation of the heart or through the release of some substance produced by the CNS or produced at another site whose release is controlled by the CNS

Cytochemical evidence of lack of basic protein in mucosal mast cells of the small intestine in the rat.

The ammoniacal silver method, which identifies basic proteins, gives a positive reaction in cytoplasmic granules of rat peritoneal mast cells. However, in cytoplasmic granules of mucosal mast cells in the small intestine of the rat, this reaction is negative.

Traumatic separation of epiphyses. An experimental study in rats.

Four types of physeal fracture-separations, defined by the Salter-Harris classification, were created experimentally in the proximal physis of the right tibia of immature rats. The four types are: Type I, pure epiphyseal separation; Type II, separation of the epiphysis with a metaphyseal fracture; Type III, partial epiphyseal separation with a vertical fracture of the epiphysis; and Type IV, vertical epiphyseal and metaphyseal fractures. A sham operation performed on the left tibia served as the control. The animals were killed at various intervals up to 25 days after the operation. The findings were assessed by roentgenographic, histologic, and vessel injection methods. For Types I and II morphometric analyses were also performed. The influence of various types of lesions on the growth rate and the healing process was documented. For Types I and II lesions there was a transitory growth arrest and an increased thickening of the zone of hypertrophic cells. The alterations regressed after Day 15, and by day 25, a nearly normal plate was seen. For Type III lesions an angular deformity of the tibia occurred that increased with time. For Type IV lesions, a step-off developed on the articular surface that became more severe with time. Early vascular anastomoses between the epiphysis and the metaphysis led to the formation of bone bridges in Type III and Type IV lesions.

Effect of chronic alcoholism upon the parietal cells of the stomach of rats.

The effects of chronic alcoholism upon the parietal cells of the stomach of rats were studied providing to a group of animals, only sugar cane brandy "ad libitum" as liquid food. A group of control animals received tap water and to both groups it was provided a balanced solid diet. During the experiment the body weight as well as liquid and solid food consumption were rated each other day. The animals were sacrificed after 45, 90 or 180 d and the effects of alcoholism evaluated at the day of sacrifice through morphological and morphometric techniques. Our results allowed us to conclude that: 1) the body weight of alcohol-treated animals increased at much slower rates when compared to controls. (2) The treated animals ingested less liquid and solid food than controls. 3) The volume of gastric secretion (ml/h/100 g of body weight) was not affected but its HCl content (mEq/l) was smaller in alcoholic rats. 4) Discrete morphological disturbance of the gastric mucosa was observed only in animals that ingested alcohol for 45 d. In the longer treatments the appearance of the mucosa was quite similar to controls. 5) The secreting mass of parietal cells decreased in alcohol treated rats. This decrease was attributed to a reduction in number of these cells.

Studies on tendon healing. A comparison between suturing techniques.

An experimental study comparing Kessler's and Tsuge's techniques for tendon suture was undertaken in dogs. Both second and fifth flexor digitorum profundi tendons of the left forepaw were divided in the segment corresponding to zone 2 of human hands. Following division, the tendons to the second digit were repaired by Kessler's technique and those to the fifth digit by Tsuge's method. Results were evaluated by means of standard and polarized--light microscopy, intravascular dye injections and tensile strength tests. Both ordinary and polarized--light microscopy showed that a microscopical gap develops between the tendon ends, being filled in with healing tissue which undergoes progressive maturation. The tensile strength tests showed that the deformation (elongation) progress directly with load, up to the point of rupture; the suture thread does not interfere with this. Furthermore, strength increases with time. Intravascular dye injection showed that a net of newly formed blood vessels develops at the site of section and suture, previously destitute of macroscopical vessels. The new vessels tended to redistribute them selves to resemble the pattern in normally vascularized regions. It was not possible to detect, by means of the methods employed, any important difference between Kessler's and Tsuge's techniques for tendon suture.

Ultrastructural changing of the rat parathyroid gland under various fixation methods.

Ultrastructural features of the rat parathyroid (PT) glands have been studied under 3 different glutaraldehyde fixation methods. Cell differences caused by fixation or due to functional conditions were evaluated. The changes of organelles and relationship of plasma membranes of chief dark-light cells, as well the pericapillary and intercellular spaces were used for this evaluation. Light cells were observed in all PT glands studied. PT glands adequately perfused presented light chief cells as transitional secretory form. Incompletely-perfused and immersion-fixed glands presented most of light chief cells as a fixation artifact. The same interpretation was given to intercellular spaces which appeared only in glands fixed by immersion. In adequately perfused glands interdigitated and straight plasma membranes of neighbour chief cells were tightly continuous with frequent desmosomes. Distended mitochondria, RER and Golgi cisternae as well vacuolizations of chief cell cytoplasm and connective tissue were characteristics of unadequately perfused glands. The best fixation method for a homogeneous preservation of all components of rat PT glands, which decreased the possibility of a wrong interpretation of normal variations, was perfusion through the left ventricle. Fixative with pH and osmolarity carefully controlled were injected after saline washing of the vascular bed.

Light- and electron microscopic observations on parathyroid glands in different age groups of rats.

The parathyroid hormone (PTH) acts on bones, intestines, and kidneys to maintain the calcium homeostasis which, in turn, is a main factor in controling the parathyroid (PT) gland activity. In all mammals studied, the chief cells of PT glands changed their size, shape, and cytoplasmic structure due to different functional states which vary the serum calcium levels. The chief cells of the rat PT glands were classified as dark and light. The dark cells may constitute an active form, characterized mainly by the abundant free ribosomes, conspicuous rough endoplasmic reticulum, and GOLGI complexes, greater number of secretory granules (SG) and increased tortuosity of the plasma membranes as compared to the light ones which were considered as a less active type of cells. Due to different calcium requirements in newborn and young rats for the ossification of growing skeleton and in adult and senile rats with consolidate mature bones, the PT glands studied with electron microscope showed various cytological features. The parenchyma of newborn and young PT glands was composed by dark chief cells. The light chief cells were more frequent in adult and senile animals as a less active type of cell. Mature SG were only occasionally observed in dark cells of newborn, young and adult PT glands. They may constitute a reserve supply of PTH but probably not the main way of secretion, according to their little number. Another pool of PTH probably answers the needs for the small basal variations in the steady-state secretion and may be represented by the vesicles observed in the chief cells cytoplasm.

Histological and ultrastructural observations of the attachment between the oral cavity of the fetus and the nipple of the mother in opossum (Didelphis azarae).

The mechanism of fixation of the fetus to the maternal nipple of opossum (Didelphis azarae) was studied in fetus of different ages through histological sections of the oral cavity keeping the nipple inside it. No organic connection was found between the maternal nipple and the tissues of the fetus. The increase of the nipple volume inside the oral cavity of the fetus and the imbrication between the corneous extracts of the nipple, palate and tongue epitheliums increase the fixation strength and contribute to the act of suckling.

Enxerto homologo de osso cortical granulado e descalcificado na correcao de falha ossea diafisaria. Estudo experimental em coelhos. / Homologous graft of granulated and decalcified cortical bone in the correction of diaphyseal bone defect. An experimental study in rabbits

No presente trabalho, foi investigada uma forma alternativa de correcao de falhas osseas diafisarias com enxerto homologo de osso cortical descalcificado, na forma de granulos. Tendo o coelho como animal de experimentacao, foram retirados cilindros de 2 cm de comprimentos da regiao medio-diafisaria de ambos os radios, preservando-se o periosteo. A falha criada foi sempre preenchida por enxerto osseo nao descalcificado a esquerda, que serviu como controle. Os animais foram estudados ate 9 semanas apos a cirurgia. Os resultados foram avaliados radiologicamente, atraves de incorporacao de corantes fluorescentes indicadores de osso neoformado, tendo como marcadores calceina azul, xilenol laranja e tetraciclina, possibilitando um estudo dinamico da osteogenese. Nas falhas preenchidas com osso descalcificado, ja havia neoformacao ossea na primeira semana, e apos 9 semanas, houve correcao completa da falha ossea em 89% dos casos, formando-se um ossiculo cilindrico, perfeitamente solidario com o restante do radio e apresentando canal medular em alguns casos

Effects of hemidecortication on the regulation of rat thyroid function.

1. Thyroid function in hemidecorticate and control rats was studied by the measurement of oxygen consumption (under basal conditions and after cold exposure) and radioiodine (131 I) uptake by the thyroid after a low-iodine diet for 30 days. 2. The oxygen uptake of male and female hemidecorticate rats under basal conditions (29 degrees C) did not differ significantly from that of the controls. The values observed for both experimental groups were relatively constant, ranging from 40 to 75 kcal h-1 m-2 for 2 to 50-day-old animals. 3. When hemidecorticate and control rats, age 60-65 days, were exposed to 7-8 degrees C for 5-6 h, the oxygen consumption of the hemidecorticate rats increased (83-84 kcal h-1 m-2) but to a lower extent than that of the controls (105-106 kcal h-1 m-2). 4. The rate of radioiodine (131 I) uptake by the thyroid gland of hemidecorticate rats was also lower than that of controls when the animals were maintained on a low-iodine diet. 5. These results show that, under basal conditions, the hypothalamic-pituitary-thyroid axis of hemidecorticate rats does not differ from that of control rats. However, when exposed to cold the hemidecorticate animals were not able to increase their oxygen consumption to the extent achieved by the control groups.

Subcellular structure of the luminal content of the cauda epididymidis of the opossum (Didelphis azarae).

The luminal content of the cauda epididymidis of the opossum has been studied by transmission electron microscopy. The content is represented by single and paired spermatozoa. Subcellular features of both spermatozoa and their cytological components have been described on the basis of the morphology of spermatozoa in the epididymis of other metatherian forms.