Hyperdynamic therapy: the nurse's role in the treatment of cerebral vasospasm

The onset of subtle diffuse ischemic neurological deficits often associated with cerebral vasospasm is a major cause of morbidity and mortality following aneurysmal subarachnoid hemorrhage. The exact etiology of cerebral vasospasm is unclear. Increasing intravascular volume, decreasing blood viscosity and inducing hypertension may help prevent or diminish neurological deficits from cerebral vasospasm by improving cerebral blood flow. An intensive multidisciplinary approach is necessary with the role of the neuroscience nurse being pivotal. An understanding of the subtle neurological changes suggestive of cerebral vasospasm and its effects leads to early recognition, and allows for rapid institution of therapy.     

Chromosomal anomalies in stage D1 prostate adenocarcinoma primary tumors and lymph node metastases detected by fluorescence in situ hybridization

We previously reported a HPLC assay method using fluorimetric detection for the simultaneous determination of urinary N2-(3-aminopropyl)biopterin (oncopterin, a natural pteridine newly found in urine from cancer patients), biopterin and neopterin. We now have observed that an unknown substance, which may be derived from methotrexate, in urine from a patient with stomach cancer interfered with the assay of oncopterin and demonstrated that oncopterin could be completely separated from the unidentified substance by HPLC using a Nucleosil 100-5SA strong cation-exchange column. Furthermore, oncopterin was not detectable by this HPLC-fluorimetric method in urine samples from patients with stomach cancer who were not treated with methotrexate. The content of urinary oncopterin from cancer patients is supposed to be very low, with less than 1 mumol/mol creatinine. The present results indicate that the peak found with elution from the C18 column was a methotrexate-derived compound and co-eluted with the analyte oncopterin.     

Technetium-99m-MIBI versus fluorine-18-FDG in diffuse multiple myeloma

Experience of scintigraphic detection of bone lesion and active bone marrow involvement of multiple myeloma, especially with sestamibi and FDG-PET scans is in evolution. We report a case of intense sestamibi uptake in bone marrow correlating with the extent of the disease, while FDG-PET scans showed activity only in areas of active disease progression associated with pain. Technetium-99m-sestamibi appears to indicate the extent of the disease, while [18F]FDG-PET scans show sites of active tumor proliferation and may be useful in directing local therapy such as radiation.     

Should diastasis recti be corrected?

From theoretical considerations animals with a higher protein-fat ratio in the body should have a higher maintenance energy requirement (MEm). The literature on this problem shows a non-uniform picture with deviating results. From the results of a series of experiments it is possible to compare the heat production (HP) of male and female animals of the Vietnamese Sway-back breed pigs which vary quite widely in their body composition. The protein-fat ratio was 1.2 for the male and 0.2 for the female animals. In the experiments 4 male and 4 female animals in the live weight range of 20-33 kg and 33-42 kg, respectively, were involved. The HP measurements were carried out in climatized respiration chambers on two levels of energy intake at ambient temperatures of 6 degrees C, 12 degrees C, 18 degrees C, 24 degrees C, 30 degrees C, and 35 degrees C. The dependence of HP on the ambient temperature has been described by a cubic regression function. Thermoneutral temperatures are lower in the female animals caused by the better insulation effect of the backfat. The difference in HP which was expected by the large difference in body composition, was not found. The absolute protein mass determined the correlation to HP. Certainly the difference increased after lowering the ambient temperature. The influence of different factors on HP is discussed.     

Atmospheric Effects on Compressive Creep of SiC-Whisker-Reinforced Alumina

A SiC-whisker-reinforced alumina composite was crept in compression at 1200° to 1400°C in an air ambient and in nitrogen. The data were described by a power-law-type constitutive relation. The measured value of the stress exponent was n = 1 at 1200°C and n = 3 at 1300° and 1400°C in both ambients. TEM observations were correlated with the measured creep response to determine active deformation mechanisms. Values of n = 1 were associated with diffusional creep and unaccommodated grain-boundary sliding, while values of n = 3 were associated with increased microstructural damage in the form of cavities. Experiments conducted in circulated air resulted in higher creep rates than comparable experiments in nitrogen. The accelerated creep rates were caused by the thermal oxidation of SiC and the resultant formation of a vitreous phase along composite interfaces. The glassy phase facilitated cavitation, weakened interfaces, and enhanced boundary diffusion.     

Habituation, prepulse inhibition, fear conditioning, and drug modulation of the acoustically elicited pinna reflex in rats.

A reliable component of the acoustic startle response in animals is a flexion of the ears, the pinna reflex (PR). The present investigation attempted to develop a preparation and apparatus suitable for analyzing the PR in the awake rat. A 2nd goal was to examine the PR under behavioral and pharmacological conditions known to affect other response systems, such as whole-body startle, and determine whether the PR is a valid model for analyzing behavioral plasticity. The amplitude of the PR in 17 spinally transected male Sprague-Dawley rats was directly related to stimulus intensity and exhibited short-term habituation, prepulse inhibition, and enhancement by prior fear conditioning. PR amplitude increased following intraperitoneal administration of strychnine HCl (0.75 mg/kg) and was decreased following clonidine HCl (40 μg/kg). It is concluded that this preparation and response system are valid for studying various forms of behavioral modification. Findings are discussed in terms of the potential utility of this response system in investigating the cellular correlates of behavioral plasticity in mammals. (30 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lesions of the amygdala, but not of the cerebellum or red nucleus, block conditioned fear as measured with the potentiated startle paradigm.

In Exp I, 97 male Sprague-Dawley albino rats were given 10 light–shock pairings on 2 successive days. At 24–48 hrs following training, groups of Ss received bilateral transection of the cerebellar peduncles, bilateral lesions of the red nucleus (which receives most of the cerebellar efferents), or bilateral lesions of the central nucleus of the amygdala. Controls were sham operated. At 3–4 days after surgery, Ss were tested for potentiated startle (PS [increased acoustic startle in the presence of the light previously paired with shock]). PS was blocked by lesions of the central nucleus of the amygdala but not by transection of the cerebellar peduncles or lesions of the red nucleus. Exp II, in which a visual prepulse test was used with 14 Ss, indicated that the blockade of PS observed in Ss with amygdala lesions could not be attributed to optic tract damage. Exp III, with 20 Ss, demonstrated that the absence of potentiation in Ss with amygdala lesions was not simply due to a lowered startle level ceiling, because these Ss could show increased startle with increased stimulus intensity and with administration of intraperitoneal strychnine, (0.75 mg/kg), a drug that increases startle. Results are consistent with the hypothesis that the amygdala is involved in fear conditioning. (64 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neuropeptide Y Y1-receptor stimulation is required for physiological amplification of preovulatory luteinizing hormone surges

Neuropeptide Y (NPY) has been shown to potentiate the actions of LHRH during the generation of preovulatory LH surges. It is not yet known, however, if activation of a specific subtype of NPY receptors in the anterior pituitary gland is an obligatory event in the stimulation of spontaneous LH surges. A battery of NPY receptor agonists, as well as the specific NPY Y1 receptor antagonist BIBP3226, were used to assess the role of Y1 receptors in the amplification of LH surges. In Exp 1, the potencies of a number of NPY agonists in facilitating LHRH-induced LH surges were assessed in pentobarbital (PB)-blocked, proestrous rats. The rank-ordered potencies of these compounds were determined to be PYY = [Leu31Pro34]NPY > NPY > hPP = rPP = NPY(13-36), which most closely reproduces the known rank-ordered affinties of these compounds for the Y1 receptor. In Exp 2, a Y1 subtype- specific antagonist, BIBP3226, was administered to unanesthetized, proestrous rats to assess the involvement of the Y1 receptor in the stimulation of spontaneous LH surges. The BIBP3226 compound strongly attenuated the endogenous proestrous LH surge, reducing the integrated value of LH secretion during the proestrous surge by more than 70%. In Exp 3, we assessed the ability of the Y1 receptor antagonist to block exogenous NPY effects on LHRH-induced LH surges. Treatment with BIBP3226 was found to completely prevent NPY amplification of LHRH-induced LH surges in pentobarbital-blocked, proestrous rats, thus confirming a pituitary locus of action of the drug. Taken together, these data clearly demonstrate that activation of neuropeptide Y receptors of the Y1 subtype is required for the physiological amplification of the spontaneous preovulatory LH surge in rats.     

Electromagnetic scattering calculated from pair distributionfunctions retrieved from planar snow sections

Electromagnetic wave scattering in dense media, such as snow, depends on the three-dimensional (3D) pair distribution function of particle positions. In snow, two-dimensional (2D) stereological data can be obtained by analyzing planar sections. In this paper the authors calculate the volume 3D pair distribution functions from the 2D stereological data by solving Hanisch's integral equation. They first use Monte Carlo simulations for multisize particles to verify the procedure. Next they apply the procedure to available planar snow sections. A log-normal distribution of particle sizes is assumed for the ice grains in snow. To derive multisize pair functions, a least squares fit is used to recover pair functions for particles with sufficient number density and the hole correction approximation is assumed for the larger particles. A family of 3D pair distribution functions are derived. These are then substituted into dense media scattering theory to calculate scattering. It is found that the computed scattering rates are comparable to those calculated under the Percus-Yevick approximation of pair distribution functions of multiple sizes