Effect of sea buckthorn berries and pulp in a liquid emulsion on gastric ulcer scores and gastric juice pH in horses.

BACKGROUND: Sea buckthorn berries (Hippophae rhamnoides) are rich in vitamin C and E, carotenoids, flavonoids, fatty acids, plant sterols, lignans, and minerals. A feed supplement containing sea buckthorn berries might have efficacy in treatment and prevention of gastric ulcers in horses. OBJECTIVES: To test the efficacy of a commercially available formulation of sea buckthorn berries and pulp (SeaBuck SBT Gastro-Plus) for treatment and prevention of gastric ulcers in stall-confined horses. ANIMALS: Eight Thoroughbred and Thoroughbred-cross horses (3-10 years of age, 5 geldings and 3 mares, 380-600 kg body weight). METHODS: This study was a 2-period crossover in which all horses received no treatment (untreated controls; n = 8) and treatment (SeaBuckSBT Gastro-Plus, 4 ounces [35.6 g berries and pulp], twice daily; n = 8) mixed with a pelleted complete feed (18% crude fiber; 9% starch; 14% crude protein). Horses were treated for 4 weeks followed by a 1-week (d28-d35) alternating feed-deprivation period to induce or worsen existing ulcers. Gastroscopic examinations were performed on days 0, 28, and 35. Gastric juice pH was measured and gastric ulcer number and severity scores were assigned by a masked investigator. RESULTS: Mean nonglandular gastric ulcer scores significantly (P < .05) increased in all horses after day 28, as a result of intermittent feed deprivation. Mean nonglandular gastric ulcer number (P = .84) and severity (P = .51) were not significantly different between SBT-treated and untreated control horses. However, mean glandular ulcer number (P = .02) and glandular ulcer severity (P = .02) were significantly lower in the SBT-treated horses compared with the untreated control at week 5. CONCLUSIONS AND CLINICAL IMPORTANCE: SeaBuck SBT Gastro-Plus liquid fed to horses did not show efficacy in treatment or prevention of naturally occurring nonglandular ulcers in horses; however, glandular ulcer scores were significantly lower in SBT-treated horses after feed deprivation. Thus, SBT might have efficacy in prevention of glandular ulcers in horses housed in stalls and undergoing intermittent feeding.

Hyperleptinemia in horses: responses to administration of a small dose of lipopolysaccharide endotoxin in mares and geldings.

Mares and geldings in good body condition selected for hyperleptinemia vs. normal leptin concentrations were studied to determine whether the hyperleptinemic condition affected various characteristics of the hematologic and hormonal systems after a challenge with lipopolysaccharide endotoxin. Four mares and 4 geldings that were determined to be hyperleptinemic (mean plasma leptin concentrations of 10.0 to 15.5 ng/mL) and 4 mares and 4 geldings with mean plasma leptin concentrations between 2.4 and 5.5 ng/mL were administered Escherichia coli O55:B5 endotoxin (35 ng/kg of BW in 500 mL of saline over a 30-min infusion), or saline only, in pairs in a single-switchback design, with horses and treatments randomly assigned for the first infusion. Physiological variables and blood components were monitored for 24 h after the onset of infusions. Treatments were switched and the second infusions were administered 8 d later. Relative to vehicle infusion, endotoxin infusion increased (P < 0.01) the rectal temperature, heart rate, respiration rate, plasma total protein concentration, and blood packed cell volume; there was an interaction of leptin status, endotoxin treatment, and time for heart rate (P = 0.039), respiration rate (P = 0.018), and plasma total protein concentration (P = 0.054). Blood concentrations of leukocytes, lymphocytes, and neutrophils all decreased (P < 0.001) after endotoxin infusion; there was an interaction (P = 0.0057) between sex and leptin status for blood platelet concentration. Plasma leptin concentrations increased (P = 0.013) after endotoxin infusion in both hyperleptinemic horses and those with reduced leptin concentrations. There were interactions (P < 0.037) of sex with endotoxin treatment and time for plasma concentrations of cortisol and prolactin, whereas plasma GH concentrations were affected (increased; P < 0.001) only by time after infusion. Given that the effects of hyperleptinemia were generally minor, it was concluded that the hyperleptinemic condition, and its associated type-2 diabetic symptoms, has a minimal impact on the components of the hematologic and hormonal systems studied.

Responses of rostral fastigial nucleus neurons of conscious cats to rotations in vertical planes.

The rostral fastigial nucleus (RFN) of the cerebellum is thought to play an important role in postural control, and recent studies in conscious nonhuman primates suggest that this region also participates in the sensory processing required to compute body motion in space. The goal of the present study was to examine the dynamic and spatial responses to sinusoidal rotations in vertical planes of RFN neurons in conscious cats, and determine if they are similar to responses reported for monkeys. Approximately half of the RFN neurons examined were classified as graviceptive, since their firing was synchronized with stimulus position and the gain of their responses was relatively unaffected by the frequency of the tilts. The large majority (80%) of graviceptive RFN neurons were activated by pitch rotations. Most of the remaining RFN units exhibited responses to vertical oscillations that encoded stimulus velocity, and approximately 50% of these velocity units had a response vector orientation aligned near the plane of a single vertical semicircular canal. Unlike in primates, few feline RFN neurons had responses to vertical rotations that suggested integration of graviceptive (otolith) and velocity (vertical semicircular canal) signals. These data indicate that the physiological role of the RFN may differ between primates and lower mammals. The RFN in rats and cats in known to be involved in adjusting blood pressure and breathing during postural alterations in the transverse (pitch) plane. The relatively simple responses of many RFN neurons in cats are appropriate for triggering such compensatory autonomic responses.

Responses of caudal vestibular nucleus neurons of conscious cats to rotations in vertical planes, before and after a bilateral vestibular neurectomy.

Although many previous experiments have considered the responses of vestibular nucleus neurons to rotations and translations of the head, little data are available regarding cells in the caudalmost portions of the vestibular nuclei (CVN), which mediate vestibulo-autonomic responses among other functions. This study examined the responses of CVN neurons of conscious cats to rotations in vertical planes, both before and after a bilateral vestibular neurectomy. None of the units included in the data sample had eye movement-related activity. In labyrinth-intact animals, some CVN neurons (22%) exhibited graviceptive responses consistent with inputs from otolith organs, but most (55%) had dynamic responses with phases synchronized with stimulus velocity. Furthermore, the large majority of CVN neurons had response vector orientations that were aligned either near the roll or vertical canal planes, and only 18% of cells were preferentially activated by pitch rotations. Sustained head-up rotations of the body provide challenges to the cardiovascular system and breathing, and thus the response dynamics of the large majority of CVN neurons were dissimilar to those of posturally-related autonomic reflexes. These data suggest that vestibular influences on autonomic control mediated by the CVN are more complex than previously envisioned, and likely involve considerable processing and integration of signals by brainstem regions involved in cardiovascular and respiratory regulation. Following a bilateral vestibular neurectomy, CVN neurons regained spontaneous activity within 24 h, and a very few neurons (<10%) responded to vertical tilts <15 degrees in amplitude. These findings indicate that nonlabyrinthine inputs are likely important in sustaining the activity of CVN neurons; thus, these inputs may play a role in functional recovery following peripheral vestibular lesions.

Effect of dexamethasone, feeding time, and insulin infusion on leptin concentrations in stallions.

Three experiments tested the hypotheses that daily cortisol rhythm, feeding time, and/or insulin infusion affect(s) leptin secretion in stallions. Ten mature stallions received ad libitum hay and water and were fed a grain concentrate once daily at 0700. In Exp. 1, stallions received either a single injection of dexamethasone (125 microg/kg BW i.m.; n = 5) or vehicle (controls; n = 5) at 0700 on d -1. Starting 24 h later, blood samples were collected every 2 h for 36 h via jugular venipuncture. Cortisol in control stallions varied (P < 0.01) with time, with a morning peak and evening nadir; dexamethasone suppressed (P < 0.01) cortisol concentrations. Leptin and insulin were greater (P < 0.01) in the treated stallions, as was the insulin response to feeding (P < 0.01). Leptin in control stallions varied (P < 0.01) in a diurnal pattern, peaking approximately 10 h after onset of eating. This pattern of leptin secretion was similar, although of greater magnitude (P < 0.01), in treated stallions. In Exp. 2, five stallions were fed the concentrate portion of their diet daily at 0700 and five were switched to feeding at 1900. After 14 d on these regimens, blood samples were collected every 4 h for 48 h and then twice daily for 5 d. Cortisol varied diurnally (P = 0.02) and was not altered (P = 0.21) by feeding time. Insulin and leptin increased (P < 0.01) after feeding, and the peaks in insulin and leptin were shifted 12 h by feeding at 1900. In Exp. 3, six stallions were used in two 3 x 3 Latin square experiments. Treatments were 1) normal daily meal at 0700; 2) no feed for 24 h; and 3) no feed and a bolus injection of insulin (0.4 mIU/kg BW i.v.) followed by infusion of insulin (1.2 mIU.kg BW(-1).min(-1)) for 180 min, which was gradually decreased to 0 by 240 min; sufficient glucose was infused to maintain euglycemia. Plasma insulin increased (P < 0.01) in stallions when they were meal-fed (to approximately 150 microIU/mL) or infused with insulin and glucose (to approximately 75 microIU/mL), but insulin remained low (10 microIU/mL or less) when they were not fed. The increases in insulin were paralleled by gradual increases (P < 0.01) in leptin concentrations 3 to 4 h later in stallions fed or infused with insulin and glucose. When stallions were not fed, leptin concentrations remained low. These results demonstrate that feeding time, and more specifically the insulin increase associated with a meal, not cortisol rhythm, drives the postprandial increase in plasma leptin concentrations in horses.

Analytical approach for sound attenuation in perforated dissipative silencers with inlet/outlet extensions.

The acoustic attenuation performance of perforated dissipative circular expansion chambers with inlet/outlet extensions is investigated. The eigenvalues and eigenfunctions of the sound field are analytically determined in the extended inlet/outlet circular ducts, upstream/downstream end annular dissipative chambers, and the central perforated dissipative expansion chamber. Utilizing the continuity conditions of velocity/pressure at the interfaces the transmission loss is predicted by a two-dimensional analytical approach. For a specific configuration, such predictions are compared with both experiments and a three-dimensional computational solution based on the substructure boundary element technique, showing a reasonable agreement. The analytical results for the effect of the absorbent resistivity, duct porosity, and geometryon the acoustic attenuation performance are discussed in detail.

Helmholtz resonator lined with absorbing material.

A closed-form, two-dimensional analytical solution is developed to investigate the acoustic performance of a concentric circular Helmholtz resonator lined with fibrous material. The effect of density and the thickness of the fibrous material in the cavity is examined on the resonance frequency and the transmission loss. With the expressions for the eigenvalue and eigenfunction in the cavity, the transmission loss is obtained for a piston-driven model by applying a pressure/velocity matching technique. The results from the analytical methods are compared to the numerical predictions from a three-dimensional boundary element method and the experimental data obtained from an impedance tube setup. It is shown that the acoustic performance of a Helmholtz resonator may be modified considerably by the density and thickness of the fibrous material without changing the cavity dimensions.

Understanding contextual fear conditioning: insights from a two-process model.

Contextual fear conditioning is an important behavioral paradigm for studying the neurobiology of learning and memory and the mnemonic function of the hippocampus. We suggest that research in this domain can profit by a better theoretical understanding of the processes that contribute to this phenomenon. To facilitate this understanding, we describe a theory which assumes that physical elements of a conditioning context represented in the brain as either (a) a set of independent features or (b) features bound into a conjunctive representation by the hippocampus which supports pattern completion. Conditioning produced by shocking a rat in a particular context, in principle, can be produced by strengthening connections between the feature representations and/or the conjunctive representation and basolateral region of the amygdala. We illustrate how this theory clarifies some of the complexities associated with the existing literature and how it can be used to guide future empirical work. We also argue that the mechanisms (conjunctive representations and pattern completion) that mediate the contribution the hippocampus makes to contextual fear conditioning are the same ones that enable the hippocampus to support declarative memory in humans.

Endocrine responses in mares and geldings with high body condition scores grouped by high vs. low resting leptin concentrations.

Previous observations from this laboratory indicated that horses with high BCS could have resting plasma leptin concentrations ranging from low (1 to 5 ng/mL) to very high (10 to 50 ng/mL). To study the possible interactions of leptin secretion with other endocrine systems, BCS and plasma leptin concentrations were measured on 36 mares and 18 geldings. From mares and geldings that had a mean BCS of at least 7.5, five with the lowest (low leptin) and five with the highest (high leptin) leptin concentrations were selected. Jugular blood samples were collected twice daily for 3 d from the 20 selected horses to determine average resting hormone concentrations. Over the next 12 d, glucose infusion, injection of thyrotropin-releasing hormone (TRH), exercise, and dexamethasone treatment were used to perturb various hormonal systems. By design, horses selected for high leptin had greater (P < 0.0001) leptin concentrations than horses selected for low leptin (14.1 vs. 2.8 +/- 0.92 ng/mL, respectively). In addition, mares had greater (P = 0.008) leptin concentrations than geldings. Horses selected for high leptin had lower (P = 0.027) concentrations of GH but higher (P = 0.0005) concentrations of insulin and thriiodothyronine (T3) than those selected for low leptin. Mares had greater (P = 0.0006) concentrations of cortisol than geldings. There was no difference (P > 0.10) in concentrations of IGF-1, prolactin, or thyroid-stimulating hormone (TSH). Horses selected for high leptin had a greater (P = 0.0365) insulin response to i.v. glucose infusion than horses selected for low leptin. Mares had a greater (P = 0.0006) TSH response and tended (P = 0.088) to have a greater prolactin response to TRH than geldings; the T3 response was greater (P = 0.047) in horses selected for high leptin. The leptin (P = 0.0057), insulin (P < 0.0001), and glucose (P = 0.0063) responses to dexamethasone were greater in horses selected for high leptin than in those selected for low leptin. In addition, mares had a greater (P < 0.0001) glucose response to dexamethasone than geldings. Cortisol concentrations were decreased (P = 0.029) by dexamethasone equally in all groups. In conclusion, differences in insulin, T3, and GH associated with high vs. low leptin concentrations indicate a likely interaction of these systems with leptin secretion in horses and serve as a starting point for future study of the cause-and-effect nature of the interactions.

'What is it?': findings on preschoolers' responses to play with medical equipment.

When young people enter a hospital they are exposed to a foreign world of unfamiliar people, medical equipment and language. Children diagnosed with leukaemia are particularly vulnerable to repeated exposure to these distressing hospital visits. Assessing a child's understanding of the stresses associated with treatment during hospitalization is now seen as a key element of caring for the paediatric patient. A population particularly vulnerable to the effects of the stress of intensive treatments during hospitalization are preschool children. In order to understand the impact on leukaemia preschool children of intensive hospital treatment it is necessary to have comparative information on healthy peers who have not been exposed to such treatment experiences. This article presents findings from recent qualitative research that explored the beliefs held by healthy preschoolers about what happens in hospital, what it means to be sick, their reactions to and knowledge of medical equipment and their level of knowledge regarding cancer and leukaemia. It is the hope and expectation that the findings will be used comparatively to contribute to a deeper understanding of the world of the child coping with leukaemia and related disorders.

Geographical distribution of cardiac arrest in Nottinghamshire.

BACKGROUND: to analyse the incidence of out-of-hospital cardiac arrest in Nottinghamshire; to ascertain its geographical distribution; and to determine whether the geography of coronary heart disease mortality and out-of-hospital cardiac arrest are the same. METHODS AND RESULTS: population based, retrospective study in the County of Nottinghamshire with a total population of 993,914 in an area of 2183 km2 divided into 191 electoral areas. In the 4 years from 1 January, 1991 to 31 December, 1994, 1634 patients sustained a cardiac arrest attributed to a cardiac cause (International Classification of Diseases codes 390-414 and 420-429) and were attended by the Nottinghamshire Ambulance Service. The overall crude mean incidence rate of community cardiac arrest per electoral area was 40.2 per 100,000 population (range 0-121.2). Thirteen electoral areas, relatively deprived according to the Townsend score, had a significantly greater than expected incidence rate of cardiac arrest (median of 75.6/100,000 per electoral area; interquartile range (IQR) 65.3, 83.8). Twelve relatively affluent electoral areas had a significantly lower than expected incidence rate (median of 18.5/100,000 per area (IQR 13.0, 28.7). After adjusting for deprivation index, there were no differences in coronary heart disease (CHD) mortality and community cardiac arrest in urban and rural electoral areas. Apart from response times by ambulance crews, the events that follow the cardiac arrest such as bystander resuscitation, ventricular fibrillation found as the presenting rhythm and survival were similar in all electoral areas. CONCLUSIONS: increasing level of deprivation is associated with areas of increased incidence of out-of-hospital cardiac arrest in Nottinghamshire, and the effect is apparently different from that on CHD mortality. There is scope for reducing incidence rates of community cardiac arrest and to introduce strategies to improve survival in areas identified as having high rates of community cardiac arrest.

Oxcarbazepine, an antiepileptic agent.

BACKGROUND: Epilepsy is a common neurologic condition. Many of the currently approved pharmacologic agents for its treatment are associated with numerous adverse drug reactions and drug interactions. OBJECTIVE: This review describes the pharmacology and therapeutic use of oxcarbazepine, an analogue of the well-known antiepileptic agent carbamazepine. METHODS: Articles for review were identified through a search of MEDLINE, International Pharmaceutical Abstracts, and EMBASE for the years 1980 through 2000. The terms used individually and in combination were oxcarbazepine, carbamazepine, epilepsy, and seizures. RESULTS: Oxcarbazepine and its primary metabolite have been effective in animal models of epilepsy that generally predict efficacy in generalized tonic-clonic seizures and partial seizures in humans. The exact mechanism of action of oxcarbazepine is unknown, although as with carbamazepine, it is believed to involve blockade of voltage-gated sodium channels. The pharmacokinetic profile of oxcarbazepine is less complicated than that of carbamazepine, with less metabolism by the cytochrome P450 system, no production of an epoxide metabolite, and lower plasma protein binding. The clinical efficacy and tolerability of oxcarbazepine have been demonstrated in trials in adults, children, and the elderly. In a double-blind, randomized, crossover trial in adults, oxcarbazepine 300 mg was associated with a decrease in the mean frequency of tonic seizures (21.4 vs 30.5 seizures during steady-state periods) and tonic-clonic seizures (8.2 vs 10.4) compared with carbamazepine 200 mg (P = 0.05). A multinational, multicenter, double-blind, placebo-controlled, randomized, 28-week trial assessed the efficacy and tolerability of oxcarbazepine at doses of 600, 1200, and 2400 mg as adjunctive therapy in patients with uncontrolled partial seizures. All 3 oxcarbazepine groups demonstrated a reduction in seizure frequency per 28-day period compared with placebo (600 mg, 26% reduction; 1200 mg, 40% reduction; 2400 mg, 50% reduction; placebo, 7.6% reduction; all, P < 0.001). A trial in children assessed the efficacy and toxicity of oxcarbazepine (median dose, 31.4 mg/kg/d) as adjunctive therapy for partial seizures. Patients receiving oxcarbazepine experienced a 35% reduction in seizure frequency, compared with a 9% reduction in the placebo group (P < 0.001). The most common adverse effects associated with oxcarbazepine are related to the central nervous system (eg, dizziness, headache, diplopia, and ataxia) and the gastrointestinal system (eg, nausea and vomiting). Compared with carbamazepine, there is an increased risk of hyponatremia with oxcarbazepine. The frequency and severity of drug interactions are less with oxcarbazepine than with carbamazepine or other antiepileptic agents. CONCLUSIONS: Oxcarbazepine may be considered an appropriate alternative to carbamazepine for the treatment of partial seizures in patients who are unable to tolerate carbamazepine. Its use in nonseizure disorders remains to be examined in large-scale clinical trials, and pharmacoeconomic comparisons of oxcarbazepine with other antiepileptic agents, particularly carbamazepine, are needed.

Coronary heart disease inequalities: deaths and the socio-economic environment in Nottingham, England.

We undertook an ecological study to investigate differences in coronary heart disease mortality within Nottingham health authority, England, to establish whether coronary mortality varied according to socio-economic status, and how mortality rates changed over a decade. An index of socio-economic status was developed from Census variables. This was used to group enumeration districts into quintiles to examine mortality inequalities. Death rates fell from 1982 to 1992, but at differential rates between the socio-economic zones. The gap in death rates between the most disadvantaged and advantaged areas widened in most population groups.

Inequalities in mortality and illness in Trent NHS Region.

BACKGROUND: The Department of Health is encouraging health authorities to improve health status by tackling health inequalities. We defined ward level spatial health variations in Trent National Health Service Region, England, investigated urban and rural inequalities, and examined the relationship with deprivation, to identify the extent of small area health inequalities and to establish whether a quantifiable difference exists between urban and rural health as affected by deprivation. METHOD: A small area ecological study design was adopted and ward level (n=591) standardized ratios were calculated (population aged <75, n=3,900,000) for specific causes of death and limiting long-term illness. A classification was devised to assess ward health inequalities according to an urban-rural dimension. Deprivation was measured using the Townsend Index and the relationship with mortality and illness was analysed using Pearson product moment correlation. RESULTS: Wide variations in mortality and illness were evident at ward level, being widest for accident mortality (standardized mortality range 0-508). Stroke mortality accounted for the largest proportion of wards with standardized mortality ratios over 125 (36.2 per cent). Relative deprivation correlated strongly with limiting long-term illness (r=0.82) and all-cause mortality (r=0.68) across Trent, and in both urban and rural environments. CONCLUSION: The study set health inequalities within a regional context for Trent as an initiative to coincide with the Government's proposed health strategy for the next few years. Wide health inequalities were evident in Trent and the association between deprivation and health was of a similar magnitude in urban and rural wards. This small area approach allows health authorities access to ward level information in order to inform key debate on tackling health inequalities and distributing resources in relation to need.

Resuscitation from out-of-hospital cardiac arrest: is survival dependent on who is available at the scene?

OBJECTIVE: To determine whether survival from out-of-hospital cardiac arrest is influenced by the on-scene availability of different grades of ambulance personnel and other health professionals. DESIGN: Population based, retrospective, observational study. SETTING: County of Nottinghamshire with a population of one million. SUBJECTS: All 2094 patients who had resuscitation attempted by Nottinghamshire Ambulance Service crew from 1991 to 1994; study of 1547 patients whose arrest were of cardiac aetiology. MAIN OUTCOME MEASURES: Survival to hospital admission and survival to hospital discharge. RESULTS: Overall survival from out-of-hospital cardiac arrest remains poor: 221 patients (14.3%) survived to reach hospital alive and only 94 (6.1%) survived to be discharged from hospital. Multivariate logistic regression analysis showed that the chances of those resuscitated by technician crew reaching hospital alive were poor but were greater when paramedic crew were either called to assist technicians or dealt with the arrest themselves (odds ratio 6.9 (95% confidence interval 3.92 to 26.61)). Compared to technician crew, survival to hospital discharge was only significantly improved with paramedic crew (3.55 (1.62 to 7.79)) and further improved when paramedics were assisted by either a health professional (9.91 (3.12 to 26.61)) or a medical practitioner (20.88 (6.72 to 64.94)). CONCLUSIONS: Survival from out-of-hospital cardiac arrest remains poor despite attendance at the scene of the arrest by ambulance crew and other health professionals. Patients resuscitated by a paramedic from out-of-hospital cardiac arrest caused by cardiac disease were more likely to survive to hospital discharge than when resuscitation was provided by an ambulance technician. Resuscitation by a paramedic assisted by a medical practitioner offers a patient the best chances of surviving the event.

Sickle cell anemia: an i.v. nursing challenge.

Patients with sickle cell anemia present a true challenge to an I.V. nurse's skill, but what is the reason for their difficult venous access? Is it the disease, its treatment, or both? The author will attempt to arrive at an answer to this perplexing situation. A review of the disease itself, the genetics involved, the pathophysiology, treatment modalities in the most frequently seen manifestations, and some possible answers to the problem are addressed.

Utilization of ribonucleic acid and deoxyoligomer primers for polyadenylic acid synthesis by adenosine triphosphate: polynucleotidylexotransferase from maize.

The ATP:polynucleotidylexotransferase isolated and purified from maize seedlings catalyzes the synthesis of polyadenylic acid by the sequential addition of 80 to 200 AMP moieties from ATP to the 3'-hydroxyl terminus of either ribo- or deoxyoligomers. Copurification of the RNA and DNA-primed activities, identical metal cofactor and reaction requirements for either primer and identical heat inactivation curves with either primer strongly suggest that both primers are utilized by the same enzyme.