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Background Preoperative L-lactatemia and heart rate have been suggested as prognostic indicators of outcome for cows with right dilatation of the abomasum or volvulus ( RDA/ AV). However, postoperative L-lactatemia has not been assessed as a potential prognostic tool. Objectives To determine the prognostic value of postoperative L-lactatemia ( LAC2), duration of treatment (Dt), relative L-lactatemia difference (compared with preoperative L-lactatemia [LAC1]) ([LAC2 − LAC1]/LAC2) and change in L-lactate over time ([LAC2 − LAC1]/Dt) as compared to preoperative findings ( LAC1 and heart rate [ HR]) as prognostic factors in dairy cows with RDA/ AV. Animals A total of 41 dairy cows were included: 19 with AV and 22 with RDA; 11 cows had a negative outcome ( NO) and 30 cows had a positive outcome ( PO) based on telephone follow-up with owners 30 days after surgery. Methods Prospective cohort study. Analysis was performed using logistic regression and comparison of area under the receiver operating characteristics curve ( AUC) using nonparametric tests. Results LAC1 > 1.4 mmol/L or LAC2 > 2.2 mmol/L had the same accuracy with sensitivity of 100% (95% CI, 75.1-100%) and specificity of 80% (95% CI, 61.4-92.3%) for predicting NO. The relative L-lactatemia difference ([LAC2 − LAC1]/LAC1) or lactate kinetics ([LAC2 − LAC1]/Dt) were not associated with prognosis. The AUC of the preoperative model (which included HR and lnLAC1) was 0.92 (95% CI, 0.83-1.0) and that of the postoperative model (including only lnLAC2) was 0.95 (95% CI, 0.88-1.0); these were not significantly different. Conclusions and Clinical Importance Postoperative L-lactatemia is helpful to predict outcome in cows with RDA/ AV. The short-term change in blood L-lactate is not a useful prognostic indicator , at least during the period of time spent on the farm for surgery and treatment. [ABSTRACT FROM AUTHOR]

243 measurements of cerebral blood flow by a noninvasive (133)Xe clearance technique have been made in 45 patients undergoing surgery for a recently ruptured cerebral aneurysm. Two groups of patients have been defined by the presence or absence of a postoperative rise in cerebral blood flow which showed a significant correlation with level of consciousness after operation. [ABSTRACT FROM AUTHOR]

Regional cerebral blood flow was measured by injection of (133)Xenon into the internal carotid artery in 11 patients with cerebrovascular disease. All patients were studied under general anaesthesia, first at normocapnia and then at hypocapnia. The 15 minute isotope clearance curves were analysed by computer by two-compartmental analysis and regional changes in flow and the proportions of fast and slow clearing tissue obtained at two levels of arterial CO(2) tension. Hypocapnia caused a fall in blood flow which was consistently accompanied by a decrease in the proportion of fast clearing tissue. Regional changes were not significantly different from the hemisphere mean changes. There was no correlation between changes in blood flow through grey matter and the proportion of fast clearing tissue on a hemisphere mean basis, but on regional analysis the data from 10 out of the 11 patients showed that in areas where blood flow through grey matter changed most the proportion of fast clearing tissue changed least and vice versa. A hypothesis has been proposed to explain this phenomenon. [ABSTRACT FROM AUTHOR]

Objective: Pertussis toxin uncoupling-based studies have shown that Gαi and Gαo can inhibit insulin secretion in pancreatic β-cells. Yet it is unclear whether Gαi and Gαo operate through identical mechanisms and how these G-protein-mediated signals inhibit insulin secretion in vivo. Our objective is to examine whether/how Gαo regulates islet development and insulin secretion in β-cells.Research Design and Methods: Immunoassays were used to analyze the Gαo expression in mouse pancreatic cells. Gαo was specifically inactivated in pancreatic progenitor cells by pancreatic cell-specific gene deletion. Hormone expression and insulin secretion in response to different stimuli were assayed in vivo and in vitro. Electron microscope and total internal reflection fluorescence-based assays were used to evaluate how Gαo regulates insulin vesicle docking and secretion in response to glucose stimulation.Results: Islet cells differentiate properly in Gαo(-/-) mutant mice. Gαo inactivation significantly enhances insulin secretion both in vivo and in isolation. Gαo nullizygous β-cells contain an increased number of insulin granules docked on the cell plasma membrane, although the total number of vesicles per β-cell remains unchanged.Conclusions: Gαo is not required for endocrine islet cell differentiation, but it regulates the number of insulin vesicles docked on the β-cell membrane. [ABSTRACT FROM AUTHOR]

Thirty five adults and two children with clinically isolated optic neuritis were examined by magnetic resonance imaging (MRI) to determine the presence of disseminated lesions within the brain at presentation and to compare these findings with the results of evoked potential studies. Of the adult patients, 61% showed lesions on the scans whereas the evoked potentials suggested the presence of lesions outside the visual system in 30%. MRI is a sensitive method for the demonstration of clinically unsuspected lesions in patients with uncomplicated optic neuritis. [ABSTRACT FROM AUTHOR]

Twenty-four cases have been operated upon using a prototype Brown-Roberts-Wells, CT-guided stereotactic neurosurgical system. This device has proved to be practical and flexible in clinical use. No CT scanner modifications were required, a fact which simplified its use in more than one hospital. Multiple targets can be biopsied with ease and relative safety. Drainage and other therapeutic procedures can be carried out with minimal hazard. Future applications of this system may include its use with NMR and PET images. [ABSTRACT FROM AUTHOR]

The responses of baboon cerebral and extracerebral arteries to prostaglandin endoperoxide (PGH2) and prostacyclin (PGI2) were investigated on isolated arteries and in vivo by serial angiography. Both PGH2 and PGI2 could produce dose-dependent contraction or relaxation of isolated arteries. PGH2 induced relaxation was indicative of prostacyclin synthetase activity, the enzyme which converts PGH2 to PGI2. In isolated arteries tested one to four hours post mortem only the vertebral artery showed prostacyclin synthetase activity. Thus PGH2 induced contraction of cerebral arteries may be indicative of a physiological function. Vasomotor tone may in part be the result of a balance between PGH2 constriction and PGI2 dilatation. In vivo PGI2 infusion caused pronounced and prolonged dilatation of cerebral arteries, which lasted longer than the cardiovascular changes. As PGI2 is the most potent cerebral vasodilator drug tested, it may be of clinical use in the treatment of cerebral vasospasm. [ABSTRACT FROM AUTHOR]

The relationship between clinical condition and vasoconstrictor factors in cerebrospinal fluid was studied in 19 patients for up to six weeks after subarachnoid haemorrhage. Vasoconstrictor activity was assayed biologically. Sixteen of 19 patients improved as vasoconstrictor activity declined; this pattern was not significantly influenced by surgery. Serial angiography was performed on three patients and a qualitative relationship was shown between arterial dilatation, clinical improvement, and reduced pharmacological activity. [ABSTRACT FROM AUTHOR]

The mode of anaesthesia used during pneumoencephalography has a significant effect on the size of the cerebral ventricles 24 hours after the procedure. Post-encephalographic ventricular enlargement is less marked in patients examined under nitrous oxide anaesthesia. This appears to be related to passage of the gas into the ventricles during the encephalogram, and subsequent diffusion outwards. Variations in arterial carbon dioxide tension during the anaesthesia do not contribute significantly to changes in ventricular size. However, both hyperventilation and inhalation of nitrous oxide may cause apparent increase in size of the cerebral sulci. [ABSTRACT FROM AUTHOR]

Patients suffering from severe migraine, usually for many years, have been examined by the EMI scanner between attacks. Judged by criteria validated originally by comparison with pneumoencephalography, about half of the patients showed evidence of cerebral atrophy. Perhaps of more significance than generalised atrophy was the frequency of areas of focal atrophy and of evidence of infarction. [ABSTRACT FROM AUTHOR]

Computerized tomography, using the EMI Scanner, allows the diagnosis of cerebral atrophy or hydrocephalus to be made with the same degree of accuracy as conventional neuroradiological methods. Ventricular measurements made on EMI scans have been compared with those from pneumoencephalograms and ventriculograms. A range of normal ventricular measurements for the EMI scan is suggested. [ABSTRACT FROM AUTHOR]

Computerized tomography has been used for the estimation of regional cerebral blood volume in a group of 18 patients. Sodium iothalamate was injected intravenously (1.75 ml/kg) to increase the absorption of x-rays in the cerebral circulation. A mean value of 5.7 ml/100 g was found for the cortex and 5.1 for tha thalamus. [ABSTRACT FROM AUTHOR]

Computerized axial tomography using the EMI scanner as a new method of using x-rays in diagnosis. The technique displays intracranial and orbital structures in the transverse plane. The appearances of normal EMI Scans are described and correlated with cerebral and orbital anatomy seen in transverse section. [ABSTRACT FROM AUTHOR]

(1) The extent and severity of visual field loss has been compared in a series of 14 patients with occlusions of the posterior cerebral artery or its branches, all verified angiographically. Atheroma, embolism, and migraine were the commonest types of underlying vascular disease. (2) Occlusion of the main trunk of the artery was associated with severe and permanent field loss usually with some sparing of the central area and, in one case, of some field adjacent to the vertical meridian. It is suggested that this is due to collateral blood flow reaching the margins of the posterior cerebral territory from the adjacent middle cerebral territory via pial anastomoses. (3) Single or multiple occlusions of the main branches of the posterior cerebral artery gave variable amounts of field loss with considerable recovery in some cases. Collateral blood flow from the middle cerebral territory and from other branches of the posterior cerebral artery was demonstrated and the variation may be due to the size and number of pial anastomoses and to systemic factors such as blood pressure and vascular reactivity. (4) Occlusion of smaller branches of the calcarine artery produced localized zones of capillary underperfusion near the posterior cerebral pole. These corresponded to scotomatous paracentral defects in the visual field which were often permanent and showed no central sparing. The potential capacity of the collateral system may be limited by occlusion of intracerebral arteries or by involvement of segments of the pial arteries in the disease process. [ABSTRACT FROM PUBLISHER]

The article reports a study in which nine healthy adult rhesus monkeys, in which cutaneous reactions to tuberculin and nervous tissue had been previously shown to be negative, were immunized by an injection into the thigh muscles of 400 mg of nervous tissue weekly for 3 weeks. The monkeys were observed daily for evidence of EAE, and were killed by cardiac puncture under pentobarbital anesthesia when the disease was fully established. After a rapid increase the cytotoxic factor maintained a steady value during a period variable for each animal suggesting the presence of a "defence reaction" against the aggressive antibody.

Tinofedrine, a new derivative of l-norephedrine, was examined for cerebral vasodilator activity in man. Ten patients with reduced cerebral blood flow (CBF) and multi-infarct dementia were given the drug intravenously. Cerebral blood flow increased significantly by 28% from a mean of 43.3 to 55.5 ml/100 g/min. [ABSTRACT FROM AUTHOR]