Long-term instrumental parameter investigation of a Fabry-Perot spectrometer at an isolated field station

To insure that long-term determinations of Doppler width and shift--derived from observations of atmospheric emissions--are internally consistent and reliable, we have developed a method to both continuously and nonintrusively determine and monitor the instrumental constants of the Fabry-Perot spectrometer making the observations. We have used this method at our isolated field experiment at South Pole, Antarctica, because the instrument is only accessible to us for a few days every year. Here we report both the method and the Fabry-Perot stability results for the past 22 years of operation. The method involves the description of real Fabry-Perot instrumental constants as a small departure from those of an ideal Fabry-Perot. In general, this model is applicable for most observations. However, experimentally, there are times when the small-departure model is not applicable, thus indicating how to best reduce the observations into physical quantities for the utmost consistency in the geophysical results.

[Diagnostic value and functional correlations of the ADAS-Cog scale in Alzheimer's disease: data on NORMACODEM project]

INTRODUCTION

The aims of this study were to assess the criterion validity of Alzheimer's Disease Assessment Scale (ADAS) and its cognitive subscale (ADAS-Cog) for the diagnosis of Alzheimer's disease (AD), and to determine their different cut-off scores and sensitivity and specificity values. In addition, we also attempted to study the possible correlations between cognitive scores (ADAS) and functional measures.

METHODS

451 subjects were studied (254 controls, 86 subjects with mild cognitive impairment and 111 patients with AD). ADAS total score was obtained by adding the cognitive (ADAS-Cog) and non-cognitive (ADAS-Nocog) scales. Scores were adjusted for age and formal education. For assessing the possible correlation between cognitive and functional measures, the following instruments were administered: Rapid Disability Rating Scale-2 (RDRS-2), Blessed Dementia Rating Scale (BDRS) and the Interview for the Deterioration of Daily Living in Dementia (IDDD).

STATISTICAL ANALYSIS

ROC curves and Pearson correlation coefficient.

RESULTS

ADAS best cut-off score for dementia was > or = 17 providing sensitivity and specificity values of 90.09% and 85.88 % respectively, while for the ADAS-Cog best cut-off score was > or = 12 with sensitivity and specificity values of 89.19 % and 88.53 % respectively. In both cases scores were adjusted for age and formal education. The area under the ROC curve was 0.95 and 0.94 respectively. Highly significant correlations were found for ADAS and 19 ADAS-Cog with the functional scales studied.

CONCLUSIONS

Both, ADAS and ADAS-Cog report good validity in terms of sensitivity, specificity and as predictive value for AD. Moreover, significant correlations were found between the functional impairment observed in patients with AD and the overall scores achieved in the ADAS and ADAS-Cog.

Validation of an 8-14 microm cloud monitor using visual observations of Antarctic cloud cover

A cloud monitor instrument, sensing 8-14 microm infrared radiation, has been installed near McMurdo, Antarctica, in order to provide supporting cloud cover information for a high-resolution sky-viewing Fabry-Perot spectrometer experiment. Validation of the cloud monitor observations was performed by a 1 year long comparison with the available 6 h visual cloud observations, expressed in octas (obscured eighths of the sky). The agreement between visual observations and those of the cloud monitor is good--the variation being slightly over one step, or octa--except at the clear sky extreme, which the subjective visual observations tend to overestimate during dark and moonless conditions. Both visual observations and the cloud monitor measurements show an austral winter-summer difference with the winter being clearer.

TRPV1 receptors in the CNS play a key role in broad-spectrum analgesia of TRPV1 antagonists

Vanilloid receptor type 1 (TRPV1) is a ligand-gated nonselective cation channel that is considered to be an important integrator of various pain stimuli such as endogenous lipids, capsaicin, heat, and low pH. In addition to expression in primary afferents, TRPV1 is also expressed in the CNS. To test the hypothesis that the CNS plays a differential role in the effect of TRPV1 antagonists in various types of pain, the analgesic effects of two TRPV1 antagonists with similar in vitro potency but different CNS penetration were compared in vivo. Oral administration of either A-784168 (1-[3-(trifluoromethyl)pyridin-2-yl]-N-[4-(trifluoromethylsulfonyl)phenyl]-1,2,3,6-tetrahydropyridine-4-carboxamide) (good CNS penetration) or A-795614 (N-1H-indazol-4-yl-N'-[(1R)-5-piperidin-1-yl-2,3-dihydro-1H-inden-1-yl]urea) (poor CNS penetration) blocked capsaicin-induced acute pain with the same potency. In complete Freund's adjuvant (CFA)-induced chronic inflammatory pain, oral administration of either compound blocked thermal hyperalgesia with similar potency. Furthermore, intraplantar or intrathecal administration of A-784168 blocked CFA-induced thermal hyperalgesia, suggesting that both peripheral and CNS TRPV1 receptors may play a role in inflammatory thermal hyperalgesia. The effects of the two TRPV1 antagonists were further assessed in models presumably mediated by central sensitization, including CFA- and capsaicin-induced mechanical allodynia and osteoarthritic pain. In these models, the potency of the two compounds was similar after intrathecal administration. However, when administered orally, A-784168, with good CNS penetration, was much more potent than A-795614. Together, these results demonstrate that TRPV1 receptors in the CNS play an important role in pain mediated by central sensitization. In addition, these results demonstrate that significant CNS penetration is necessary for a TRPV1 antagonist to produce broad-spectrum analgesia.

Comparison of antinociceptive actions of standard analgesics in attenuating capsaicin and nerve-injury-induced mechanical hypersensitivity

Intradermal capsaicin injection produces immediate spontaneous pain behaviors, and a secondary mechanical hypersensitivity (SMH) that is employed in the clinic as a model potentially predictive of human neuropathic pain. Presently, we have characterized capsaicin-induced SMH in rats, and compared pharmacological actions of standard analgesics in this and two nerve injury models, the L5/L6 spinal nerve ligation (SNL) and sciatic nerve chronic constriction injury (CCI) models. Intraplantar capsaicin produced dose-related SMH (enhanced paw withdrawal response to von Frey monofilament stimulation at an area away from injection site) that lasted for over 4 h. While pretreatment with a potent selective transient receptor potential vanilloid receptor-1 (TRPV1) antagonist A-425619 (1-isoquinolin-5-yl-3-(4-trifluoromethyl-benzyl)-urea) prevented development of acute nocifensive (flinching) behavior immediately following capsaicin injection (ED(50)=4.9 mg/kg), the compound failed to attenuate the SMH when administered 2 h following capsaicin (10 microg/10 microl). Additional standard analgesics were also tested 3 h following intraplantar capsaicin in the SMH model. Comparison of their potencies in attenuating mechanical hypersensitivity in capsaicin, SNL and CCI models revealed similar ED(50)s for morphine (2.3 mg/kg, 1.6 mg/kg and 3.2 mg/kg, respectively), gabapentin (33.1 mg/kg, 33.9 mg/kg and 26.3 mg/kg, respectively) and lamotrigine (9.1 mg/kg, 8.9 mg/kg and 15.5 mg/kg, respectively). Duloxetine produced 50-65% effect at the highest tested dose (50 mg/kg), whereas the highest tested doses of morphine (10 mg/kg), gabapentin (85.5 mg/kg) and lamotrigine (30 mg/kg) all produced >70% efficacy in capsaicin SMH, SNL and CCI models. In contrast, celecoxib and ibuprofen showed weak effects in all three models. All standard analgesics generally had weak efficacy in attenuating capsaicin-induced immediate acute flinching behavior when administered before capsaicin. These results provide further support to the suggestions that distinct pharmacological mechanisms underlie capsaicin-induced acute nocifensive and SMH behaviors, and certain neuronal mechanisms underlying neuropathic pain states are also contributory to capsaicin-induced SMH.

Treatment of restless legs syndrome with gabapentin: a double-blind, cross-over study

OBJECTIVE

To assess the effects of gabapentin on sensory and motor symptoms in patients with restless legs syndrome (RLS).

METHODS

Patients with RLS (22 idiopathic, 2 secondary to iron deficiency) were randomized and treated for 6 weeks with either gabapentin or placebo. After a 1-week washout they crossed over to the alternative treatment for 6 weeks. Patients were rated at baseline and at scheduled intervals by the RLS Rating Scale, Clinical Global Impression, pain analogue scale, and Pittsburgh Sleep Quality Index. At the end of each treatment period, all-night polysomnography was performed.

RESULTS

Compared to placebo, gabapentin was associated with reduced symptoms on all rating scales. In addition, sleep studies showed a significantly reduced periodic leg movements during sleep (PLMS) index and improved sleep architecture (increased total sleep time, sleep efficiency, and slow wave sleep, and decreased stage 1 sleep). Patients whose symptoms included pain benefited most from gabapentin. The mean effective dosage at the end of the 6-week treatment period was 1,855 mg, although therapeutic effects were already observed at the end of week 4 (1,391 mg).

CONCLUSIONS

Gabapentin improves sensory and motor symptoms in RLS and also improves sleep architecture and PLMS.

[Primitive neuroectodermal tumor of the cauda equina. Report of a case]

Primitive neuroectodermal tumors are malignant neoplasms whose classification has been controversial. Spinal primitive neuroectodermal tumors are rare and at the cauda equina are even less common. We report the case of a 40 year-old man with a history of progressive back pain and gait difficulty. After the diagnosis of a primitive neuroectodermal tumor of the cauda equina, the patient presented seeding to the intracranial subarachnoid space followed by a poor outcome. We review the literature of primary spinal primitive neuroectodermal tumors.

Influence of polymeric enteral nutrition supplemented with different doses of glutamine on gut permeability in critically ill patients

OBJECTIVES

To evaluate the effect of glutamine-supplemented polymeric enteral formulas on the recovery of gut-permeability abnormalities in critically ill patients.

METHODS

Twenty-three patients were randomized to receive a conventional casein-based enteral formula (ADN), ADN plus glutamine in a dose of 0.15 g x kg(-1) x d(-1) or ADN plus 0.30 g x kg(-1) x d(-1) of glutamine for 8 d. The lactulose mannitol permeability test (L/M) was performed at baseline and at the end of the study. Nineteen healthy volunteers served as controls for the L/M test.

RESULTS

An increase in permeability compared with control subjects was observed in patients at baseline (mean +/- standard error of the mean; L/M ratio: 0.11 +/- 0.03 and 0.025 +/- 0.004, respectively; P < 0.02). The L/M ratio improved after the period of enteral nutrition as a whole (initial L/M: 0.11 +/- 0.03, final L/M: 0.061 +/- 0.01; P < 0.03), but no difference was found between groups.

CONCLUSIONS

Even though polymeric enteral nutrition was associated with a significant improvement in the L/M ratio, glutamine supplementation did not show a specific influence in improving recovery of gut permeability in critically ill patients.

[Microalbuminuria, pulse wave velocity and common carotid artery intima-media thickness in type 2 diabetes]

The aim of the study was to evaluate pulse wave velocity (PWV) and carotid intima-media thickness (IMT) in type 2 diabetics with microalbuminuria (mualb). The study concerned 37 patients type 2 diabetics, age: 53.4 +/- 6.6, years free of cardiovascular complications. HbA1C was 7.73 +/- 1.39%, waist circumference 104.2 +/- 11.7 cm. 19 patients with BP > 130/85 mmHg were identified as mild hypertensives (17/19 under treatment). All patients underwent ABPM, PWV and IMT measurements. The study population was separated into 2 subgroups according to median of mualb (mg/24 h): 18.9. [table: see text] In patients with mualb > 18.9 mg/24, IMT and PWV were significantly increased (p = 0.06; p < 0.01). After adjustment to BP and age, there was no significant difference in IMT and PWV in the subgroups. In this selected population of type 2 diabetics, microalbuminuria appears associated to a pressure-dependant vascular remodeling.

Millisecond time scale conformational flexibility in a hyperthermophile protein at ambient temperature

Rubredoxin from the hyperthermophile Pyrococcus furiosus is the most thermostable protein characterized to date with an estimated global unfolding rate of 10(-6) s(-1) at 100 degrees C. In marked contrast to these slow global dynamics, hydrogen exchange experiments here demonstrate that conformational opening for solvent access occurs in the approximately millisecond time frame or faster at 28 degrees C for all amide positions. Under these conditions all backbone amides with exchange protection factors between 10(4) and 10(6), for which EX(2) exchange kinetics were directly verified, have exchange activation energy values within 2-3 kcal/mol of that observed for unstructured peptides. The conformational flexibility of this protein is thus sufficient for water and base catalyst access to the exchanging amide with quite limited structural disruption. The common hypothesis that enhanced conformational rigidity in the folded native state underlies the increased thermal stability of hyperthermophile proteins is not supported by these data.

Decreased NADH glutamate synthase activity in nodules and flowers of alfalfa (Medicago sativa L.) transformed with an antisense glutamate synthase transgene

Legumes obtain a substantial portion of their nitrogen (N) from symbiotic N2 fixation in root nodules. The glutamine synthetase (GS, EC 6.3.1.2)/glutamate synthase (GOGAT) cycle is responsible for the initial N assimilation. This report describes the analysis of a transgenic alfalfa (Medicago sativa L.) line containing an antisense NADH-GOGAT (EC 1.4.1.14) under the control of the nodule-enhanced aspartate amino-transferase (AAT-2) promoter. In one transgenic line, NADH-GOGAT enzyme activity was reduced to approximately 50%, with a corresponding reduction in protein and mRNA. The transcript abundance for cytosolic GS, ferredoxin-dependent GOGAT (EC 1.4.7.1), AAT-2 (EC 2.6.1.1), asparagine synthase (EC 6.3.5.4), and phosphoenolpyruvate carboxylase (PEPC, EC 4.1.1.31) were unaffected, as were enzyme activities for AAT, PEPC and GS. Antisense NADH-GOGAT plants grown under symbiotic conditions were moderately chlorotic and reduced in growth and N content, even though symbiotic N2 fixation was not significantly reduced. The addition of nitrate relieved the chlorosis and restored growth and N content. Surprisingly, the antisense NADH-GOGAT plants were male sterile resulting from inviable pollen. A reduction in NADH-GOGAT enzyme activity and transcript abundance in the antisense plants was measured during the early stages of flower development. Inheritance of the transgene was stable and resulted in progeny with a range of NADH-GOGAT activity. These data indicate that NADH-GOGAT plays a critical role in the assimilation of symbiotically fixed N and during pollen development.

Ultrastructural alterations in the adrenal gland cortex of mice experimentally infected with a Venezuelan isolate of Trypanosoma evansi

The ultrastructural study of adrenal gland from mice experimentally infected with Trypanosoma evansi, in addition to intravascular and intracellular trypanosomes, showed different degrees of cortical cell alterations and capillary wall modifications. Beside its biological scope, these results suggest a role for the adrenal cortex to partake in Surra's etiopathogenesis and describe for the very first time a T. evansi intracellular stage.

Gut mucosal atrophy after a short enteral fasting period in critically ill patients

PURPOSE

The purpose of this study was to evaluate the presence of gut mucosal atrophy and changes in mucosal permeability in critically ill patients after a short fasting period.

MATERIALS AND METHODS

Fifteen critically ill patients underwent a period of enteral fasting of at least 4 days (mean 7.8 days). We took the following measurements the day before initiating enteral nutrition: indirect calorimetry, serum albumin, prealbumin, and lymphocyte count. We also performed a duodenal endoscopic biopsy with histopathological and mucosal morphometric analysis including villus height and crypt depth. The lactulose-mannitol test was performed to assess gut permeability. A total of 28 healthy volunteers served as controls for duodenal biopsy or lactulose-mannitol test. Clinical data, such as length of fasting, severity score, and previous parenteral nutritional support, were recorded.

RESULTS

We found gut mucosal atrophy, expressed as a decrease in villus height and crypt depth, in patients compared with controls. The patients also exhibited an abnormal lactulose-mannitol test. Morphometric changes did not correlate with permeability. Further, we found no correlation between the results of the lactulose-mannitol test and of mucosal morphometry with clinical data.

CONCLUSIONS

We found that a short period of enteral fasting was associated with significant duodenal mucosal atrophy and abnormal gut permeability in critically ill patients.

Care paths. A new approach to high-risk maternal-child home visitation

Care paths for the maternal and infant populations are used to define immediate and long-term outcomes related to care received in the home. This article describes a care path developed by public health nurses for intervention with an at-risk maternal-child population in a city/county health department. A public health nursing care management model provided the framework for developing this care path to foster cost-effective use of limited resources. It is crucial that public health nurses articulate clearly the services provided in the home both for those who may seek service and for policy makers who determine funding structure. The project demonstrated that care paths for home visitation involving high-risk prenatal clients are useful tools that streamline documentation, foster consistency and continuity of care, facilitate quality improvement efforts, and provide outcome data.

Development of Weiner et al. force field parameters suitable for conformational studies of [1,4]-benzodiazepines and related compounds

A set of force field parameters capable of reproducing the preferred conformations of the biologically important [1,4]-benzodiazepines was developed for AMBER and other molecular modeling programs that utilize the Weiner et al. force field. Equilibrium parameters were obtained from representative model compounds found in the Cambridge Structural Database, and bond stretching and torsion potential force constants were estimated using AM1 and PM3 semiempirical Hamiltonians. Parameters obtained with the two semiempirical methods and the existing linear interpolation method are compared. Molecular mechanics and dynamic simulations showed that AM1 derived parameters, together with MNDO ESP fitted atomic charges, predicted the X-ray structure of a number of representative [1,4]-benzodiazepines within 0.01 A, 0.8 degree, and 5 degrees, from observed bond lengths, bond angles, and bond torsions, respectively.

Changes in the quality of life of patients with end-stage renal disease treated with high-efficiency bicarbonate hemodialysis in Mexico

In accordance with the epidemiological changes in Mexico, the results of this study are intended to contribute to the evaluation of the end-stage renal disease (ESRD) program of the health services in Mexico. We measured the quality of life of 21 ESRD patients before and after 6 months of exposure to treatment with high-efficiency hemodialysis with bicarbonate (HEHD/bicarbonate). We cross-sectionally assessed the Quality Adjusted Life Year (QALY) index and the biochemical status of the subject pool. The QALY score for patients undergoing HEHD/bicarbonate after 6 months was significantly higher than with the previous dialysis modality (0.95 and 0.74, respectively, p = 0.02). The marked similarities of the biochemical status variables indicated there was little or no effect in the improvement of the quality of life of patients. Dialysis modality likely exerts an important influence on the quality of life of chronic dialysis patients; thus we believe HEHD/bicarbonate does offer greater benefits than hemodialysis alone. Longitudinal studies are needed to better ascertain the effect of the case mix, the treatment approach, and the characteristics of the dialysis in relation to the improvement of the quality of life of ESRD patients.