Chronic gypsum fertiliser ingestion as a significant contributor to a multifactorial cattle mortality

A number of high-resolution molecular typing systems have been developed in recent years. Their availability raises the new issues of selecting the method (s) best suited for a particular purpose and interpreting and communicating typing results. Most of the currently available methods are comparative only: they allow testing of a sample of isolates for delineation of those closely related from those markedly different in genomic backgrounds. This approach is adequate for outbreak investigation, allowing determination of clonal spread in a microenvironment and identification of the source of infection. Comparative methods with sufficient resolution for most pathogens include restriction fragment-length polymorphism (RFLP), pulsed-field gel electrophoresis (PFGE), and arbitrarily primed and randomly amplified polymorphic DNA-polymerase chain reaction (PCR) analysis. For surveillance systems, monitoring clonal spread and prevalence in populations over extended periods of time requires library typing systems. These must be standardized, must have a high throughput, and must use a uniform nomenclature. Promising or validated methods include serotyping, insertion sequence fingerprinting, ribotyping, PFGE, amplified fragment-length polymorphism (AFLP), infrequent-restriction-site amplification PCR, interrepetitive element PCR typing (rep-PCR) and PCR-RFLP of polymorphic loci. PCR methods generating arrays of size-specific amplicons (AFLP, rep-PCR) can be more reproducibly analyzed by using denaturing polyacrylamide gel or capillary electrophoresis with automated laser detection. Binary probe typing systems appear optimal and should be enhanced further through use of DNA chip technology. In these systems, amplification of polymorphic regions is followed by solid-phase hybridization with a reference panel of sequence-variant specific probes. The resulting binary type results allow determination of reproducible, numeric profiles. However, interpretation and nomenclature of typing results for large-scale surveillance purposes still require a better understanding of population structure and microevolution of most microbial pathogens.     

Establishment of a learned preference for a zinc-containing solution by zinc-deficient rats.

24 zinc-deficient, male Holtzman albino rats were trained to associate a novel-tasting solution with the partial amelioration of their deficiency. For 4 days, Ss were permitted to drink only a distasteful acetic acid solution containing a small quantity of zinc. When later offered a choice between a solution associated with the deficiency (distilled water) and an acetic acid solution, the Ss strongly preferred the latter. This contrasted sharply with choices of zinc-deficient Ss which had no previous experience with the acid-zinc solution. This group showed a strong aversion to the taste of the acid. Results also show (a) a positive correlation between weight gain during the 4-day education period and preferences for the acid-zinc solution, (b) a unique dietary sampling pattern among deficient Ss with prior exposure to zinc, and (c) a strong resistance to extinction of consumption of the novel acidic solution when zinc had been deleted. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Some determinants of milk ingestion in suckling rats.

Eight experiments were conducted to examine several possible determinants and controls of milk intake in 10-day-old preweanling Sprague-Dawley rats. Results indicate that while the amount of milk the mother provides is a major determinant of milk consumption, pups will individually adjust their intake in response to certain treatments. Deprived pups ingested more milk than nondeprived littermate controls if given access to enough milk. Intragastric intubations of skimmed milk or distilled water reduced milk intake; heavy cream or isotonic saline did not. Injections of polyethylene glycol or formalin, which produced hypovolemia, increased milk consumption, and hypertonic saline decreased it. Results indicate that preweanling rats are behaviorally responsive to certain changes in body fluids and suggest that milk intake involves more than an invariant reflex. (30 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Massive hepatic necrosis secondary to treatment of hepatocellular carcinoma by percutaneous alcoholization

This study assesses the ability of plasma from women with pre-eclampsia to induce altered endothelial function in myometrial resistance vessels from normotensive women. Vessels from normotensive pregnant women (n = 7) were incubated with plasma from other pregnant women who were normotensive (n = 6) or had pre-eclampsia (n = 7). A wire myograph was used to test the endothelium-dependent relaxatory response to bradykinin of preconstricted vessels. The relaxation in vessels incubated with plasma from women with pre-eclampsia was markedly less than in vessels incubated with plasma from normotensive pregnant women (P = 0.039). This supports the theory that a plasma-borne factor contributes to the endothelial changes seen in pre-eclampsia.     

The effect of the long-term alcoholization of rats on partial kidney functions under increasing hypo- and hyperosmolarity

After prolonged alcoholisation of rats the water loads paradoxically induced a lesser water and univalent cations excretion as compared with the control. The same animals excreted less water and sodium and more potassium after the salt loads.     

Ontogeny of suckling in rats: Transitions toward adult ingestion.

Studied the suckling behavior of neonatal Sprague-Dawley rats on their own anesthetized mother from the day of birth until after weaning (35 days). Even newborn Ss were capable of nipple attachment without maternal assistance. Before 11–23 days of age, pups deprived of suckling for 22 hrs and nondeprived pups quickly attached to their mother's nipples, sucked, and remained attached to the nipple though no milk delivery occurred. Then behavior underwent at least 3 changes: (a) After 11–23 days of age, latency to attach became considerably elevated in nondeprived pups; (b) a 2nd change in latency occurred at 23–25 days of age, when nondeprived pups no longer even attached to the nipples of anesthetized mothers; and (c) about 14 days of age, deprived pups began to shift from 1 nipple to the next after initial attachment. These developmental changes were seen in other test situations in which pups were placed directly on a nipple and not required to search and when various periods of deprivation were utilized. These transitions were not critically dependent on the onset of visual function or on the pup's experience with food other than mother's milk. Suckling, therefore, in not an unmodified reflex but is an appetitive behavior that undergoes a series of changes during development. These transitions constitute major developmental events in the ontogeny of rat ingestive behavior. (48 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Oropharyngeal control of ingestion in rats: Acquisition of sham-drinking patterns.

Conducted 3 experiments with female Sprague-Dawley rats with esophageal fistulas (3 Ss in Exp I, 3 in Exp II, and 4 in Exp III). Offered a concentrated glucose solution, Ss sham drank relatively small amounts on the 1st session, whether or not such a solution was familiar. Intake rose to high levels over ensuing sham-drinking sessions, showing that the initial small volumes were not attributable to fixed properties of the solution itself. The gradual acquisition of copious sham drinking was not affected by previous "practice" at sham drinking other commodities; it was not simply an alteration in motor habits. The gradual acquisition of the sham-drinking pattern did not occur with more dilute solutions; in response to these, sham drinking was copious and continuous from the onset. The following conclusions are made: (a) Rats must learn to respond, by continuous drinking, to the absence of the postingestive inhibition normally produced by concentrated solutions. (b) No such learning is required in the case of more dilute solutions. This is further evidence that controlling factors with differing properties operate at different levels even of the single commodity, glucose in solution. (17 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Chronic administration of ORG 2766 for 6 months produces a subtle impairment in strategic learning by rats

Dysfunctions in serotonergic pathways may underlie several psychiatric disorders. The reuptake of serotonin (5-HT) from synaptic terminals is mediated by a specific transporter (5-HTT). Genetic variation in the gene coding for the 5-HTT protein might be involved in the predisposition to psychiatric disorders. A systematic screening of the whole coding sequence of the 5-HTT gene in mood disorder (MD) and obsessive-compulsive disorder (OCD) patients, as well as in healthy controls, using PCR and denaturing gradient gel electrophoresis (DGGE) revealed the presence of two mutations. The first was in intron 4, and the second was a C-->A transversion leading to an amino-acid exchange (Leu-->Met) in position 255 of the deduced protein sequence. No further occurrence of this substitution was found in an extended sample of patients and controls. Therefore, structural modifications of the 5-HTT gene do not seem to play either a major or minor role in the genetic predisposition to MD or OCD.     

Brain transections selectively alter ingestion and behavioral activation in neonatal rats.

Food-deprived neonatal rats actively ingest milk that is infused into their mouths through intraoral cannulas. This ingestion is accompanied by behavioral activation. The involvement of various brain regions in ingestion and activation was examined in 2-day-old Charles River pups by making transections along the neuraxis from the olfactory bulbs to the anterior pons. Following a 24-hr deprivation period, a series of oral milk infusions was given, and milk intake and activity were measured. Intake was severely reduced only in Ss with diencephalic transections. Cuts in front of or behind the diencephalon resulted in normal or slightly decreased intake. In contrast, activity tended to decline as the level of the transection became more caudal. Thus ingestion and its accompanying behavioral activation could be separated neuroanatomically. These results suggest that 2 brain mechanisms are involved in the ingestive response of the infant rat, one in the diencephalon and another caudal to the mesencephalon. However, behavioral activation appears less discretely organized, involving most of the neuraxis. (28 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Induction of hyperhydration in rats by IP loading with graded concentrations of NaCl solution

In April 1991, 91 hospitalized patients in Cairo were reported to the Egyptian Ministry of Health with botulism intoxication. To define the spectrum of illness and identify a food vehicle, 45 patients were interviewed and a case-control investigation was conducted among families of 5 hospitalized patients. Clinical specimens and specimens of implicated food were tested for toxin and cultured for Clostridium botulinum. Hospitalized patients had symptoms consistent with botulism; 18 (20%) of 91 reported patients died. Illness was associated with eating faseikh (uneviscerated, salted mullet fish; lower 95% confidence limit of odds ratio = 6.6, P < .001). All 5 case-families purchased faseikh from one shop. Very high levels of type E botulinal toxin were detected in faseikh reported to be purchased from the implicated shop; C. botulinum type E was isolated from cultures of clinical specimens and from the faseikh. This is the first documented outbreak of botulism in Egypt and the largest type E outbreak ever reported.     

Renal and hepatic nitrogen metabolism during NH4Cl ingestion in protein-deprived rats

PURPOSE: We assessed the morphodynamic features of cavernous arteries and helicine arterioles by power Doppler sonography in vasculogenic and nonvasculogenic impotent men. MATERIALS AND METHODS: A total of 40 impotent patients with and without definite vascular risk factors were studied by penile power Doppler sonography. The test was performed during penile flaccidity, after intracavernous injection of 20 mcg. alprostadil and after subsequent genital and audiovisual sexual stimulation. A second injection and stimulation were given if the erectile response observed after the initial injection was less than the maximum erection seen during sexual activity. Morphodynamic parameters evaluated by power Doppler imaging included vessel course, shape, wall thickness and pulsatility, peak systolic velocity, end diastolic velocity, acceleration time and resistance index. RESULTS: In the nonvasculogenic group all patients who achieved rigid erection showed normal cavernosal artery and helicine arteriole inflow. In these cases the arteriolar picture was characterized by the presence of 3 orders of distal ramifications originating from the cavernous arteries with an acute angle, systolic diastolic flow during penile tumescence and systolic flow alone at full rigidity. In the vasculogenic group patients with normal cavernous artery inflow showed an arteriolar tree that was pathological in 50% and was characterized by a reduced number of ramifications originating perpendicularly from the cavernous arteries and irregular caliber (arteriolar impotence). In the same group patients with reduced cavernous artery inflow also showed normal or pathological arteriolar components (pre-penile arterial impotence and diffused penile arterial impotence). CONCLUSIONS: Power Doppler sonography allows a precise study of the morphodynamics of the cavernous arteries and helicine arterioles. Our preliminary data suggest that the intracavernous arteriolar component may have a significant role in the genesis of some forms of vasculogenic impotence.     

Decremental carryover effects of sucrose ingestion in the negative anticipatory contrast procedure in rats.

To test for retrospective effects of sucrose ingestion in the anticipatory contrast procedure, 4 experiments examined intake of an initial 0.15% saccharin solution as a function of the unsignaled interspersing of days in which the 2nd solution was 32% sucrose or 0.15% saccharin. In Experiment 1, rats that received alternating saccharin-saccharin days and saccharin-sucrose days drank less saccharin on saccharin-only days, and on both days they drank less saccharin than a control group that received saccharin only. In Experiment 2, rats that received randomized saccharin-saccharin and saccharin-sucrose days drank less saccharin if, and only if, a sucrose day preceded. Experiments 3 and 4 used double and quadruple alternation of saccharin and sucrose days to examine persistence of the effects of a sucrose day. The results highlighted a retrospective carryover effect of sucrose that reduced intake of the initial saccharin solution and apparently was based on sucrose memories persisting over days. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of a nucleotide-nucleoside solution on hepatic regeneration after partial hepatectomy in rats

After hepatectomy, purine and pyrimidine metabolism is a key process in the synthesis of DNA and RNA and maintaining cellular energy metabolism. The purpose of this study is to evaluate changes in blood purine and pyrimidine levels after partial hepatectomy and the effect of purine and pyrimidine nucleoside solution injection on hepatic regeneration under the hypothesis that the rat after partial hepatectomy requires substrates for salvage nucleotide synthesis and changes blood nucleoside and nucleobase levels. Blood levels of nucleotides, nucleosides, and nucleobase by high-performance liquid chromatography method and liver ATP level by enzymatic analysis, and the effect of preoperative injection of nucleoside solution (OG-VI) on hepatic regeneration ratio and hepatocytes DNA synthesis, were assessed in rats after 70% partial hepatectomy. Decreased liver adenosine triphosphate and increased plasma xanthine and hypoxanthine after partial hepatectomy indicated an increase in catabolism of purine nucleotides in regenerating liver. Plasma thymidine and cytidine levels increased, then returned to the prevalue, suggesting that the thymidine and cytidine pool was enlarged. OG-VI increased labeling indices of hepatocytes at postoperative d 1 (POD) and hepatic regeneration ratio at POD 14. Blood purine nucleobase and pyrimidine nucleoside levels change after partial hepatectomy and preoperative supply of nucleoside solution is effective for increasing hepatocytes DNA synthesis and hepatic regeneration after partial hepatectomy.     

Chronic treatment with losartan ameliorates vascular dysfunction induced by aging in spontaneously hypertensive rats

OBJECTIVE: To evaluate the effects of prolonged treatment with losartan on endothelium-dependent and endothelium-independent relaxations of aortic rings from adult and senescent spontaneously hypertensive rats, and to clarify whether these effects were due to specific mechanisms of the drug or a consequence of its blood-pressure-lowering action. MATERIALS AND METHODS: Adult (aged 5 months) and senescent (aged 20 months) male spontaneously hypertensive rats were treated for 12 consecutive weeks with 10 mg/kg per day losartan. Systolic blood pressure and plasma concentration of nitrates were evaluated. We studied endothelium-dependent and endothelium-independent relaxations and response to angiotensin II of aortic rings from rats of each group. The direct effects of angiotensin II type 1 receptor antagonism on vascular reactivity of aortic rings from untreated adult and senescent rats that had been incubated beforehand with losartan were also studied. RESULTS: Losartan treatment comparably reduced blood pressure and increased plasma concentration of nitrates in rats of both age groups. Responses to acetylcholine and sodium nitroprusside were lower for rings from senescent than they were for rings from adult rats. Constrictor responses to angiotensin II were higher for rings from senescent than they were for rings from adult rats. Treatment with losartan increased the magnitude of relaxations in response to acetylcholine for rings from rats in both groups, but increased the magnitude of relaxations in response to nitroprusside only for rings from senescent spontaneously hypertensive rats. Incubation beforehand of aortic rings from untreated rats with losartan enhanced magnitude of relaxations in response both to acetylcholine and to nitroprusside only for rings from senescent spontaneously hypertensive rats. CONCLUSIONS: The consequences of aging for endothelium-dependent and endothelium-independent relaxations of rings from spontaneously hypertensive rats are ameliorated by losartan treatment, suggesting that angiotensin II plays a role via type 1 receptors. The effects of losartan on senescent spontaneously hypertensive rats were due not only to its blood-pressure-lowering action but also to the blockade of specific mechanisms derived from angiotensin II type 1 receptor antagonism, which might involve an increase in availability of NO.     

Soil ingestion in adults--results of a second pilot study

Numerous in vivo methodologies have documented the invasive behavior of glioma cells through normal brain parenchyma. Glioma cell locomotion has also been assessed with a number of in vitro assays including the Boyden chamber and other chemotaxis assays, colloidal gold cell tracking, analysis of migration of cells tumor cells from spheroids, confrontation cultures of glioma cells with aggregates of non-neoplastic tissue, time-lapse video microscopy, electron microscopic examination of the cytomorphologic correlates of cell motility, the radial dish assay, and quantitative enzyme immunoassay of proteins associated with invasion (e.g. laminin). Several of these techniques have been specifically modified to assess the effects of cytokines on glioma cell motility in vitro. Cytokines studied utilizing these methods include: epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), the bb dimer of platelet-derived growth factor (PDGFbb), nerve growth factor (NGF), interleukin 2 (IL-2), transforming growth factors alpha and beta 1 (TGF alpha and TGFstraat1), and tumor necrosis factor alpha (TNF alpha). This review summarizes the investigational methods used to evaluate random and directional glioma cell motility and invasion in vivo and in vitro. The roles of specific mitogens as motogens, as evaluated with these methods are then presented.     

Dystrophic and reparative changes in the cortical neurons of rat progeny in moderate prenatal alcoholization

Dynamics of dystrophic and reparative changes of sensorimotor cortex neurons ultrastructure in 21, 30 and 60-days progeny of rat treated with moderate doses of alcohol during pregnancy was studied with these changes found in mature cortical neurons having their own dynamics in postnatal ontogenesis. Dystrophic changes are better expressed until the age of a month. Signs of reparative processes increase with age, but hypoxically ischemic dystrophic neuronal changes remain up to puberty, which indicates effectiveness of moderate prenatal action of alcohol.     

Control of ingestion by oral habituation in rat pups.

The role of habituation of mouthing activity in the control of ingestion was investigated in 6-, 12-, and 18-day-old rat pups. In pups at all ages, oral habituation to a flavored diet inhibited ingestion of a continuous oral infusion of that same diet. 12-day-old pups that had orally habituated to a diet continued to consume less of a continuous oral infusion of that diet both 30 min and 3 hrs later, and the duration of suppressed ingestion was shown to be dependent on the rate of stimulus presentation during habituation experience. These data suggest that oral habituation may be a diet-specific influence on both intra- and intermeal patterning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)