An active atmospheric methane sink in high Arctic mineral cryosols.

Methane (CH4) emission by carbon-rich cryosols at the high latitudes in Northern Hemisphere has been studied extensively. In contrast, data on the CH4 emission potential of carbon-poor cryosols is limited, despite their spatial predominance. This work employs CH4 flux measurements in the field and under laboratory conditions to show that the mineral cryosols at Axel Heiberg Island in the Canadian high Arctic consistently consume atmospheric CH4. Omics analyses present the first molecular evidence of active atmospheric CH4-oxidizing bacteria (atmMOB) in permafrost-affected cryosols, with the prevalent atmMOB genotype in our acidic mineral cryosols being closely related to Upland Soil Cluster α. The atmospheric (atm) CH4 uptake at the study site increases with ground temperature between 0 °C and 18 °C. Consequently, the atm CH4 sink strength is predicted to increase by a factor of 5-30 as the Arctic warms by 5-15 °C over a century. We demonstrate that acidic mineral cryosols are a previously unrecognized potential of CH4 sink that requires further investigation to determine its potential impact on larger scales. This study also calls attention to the poleward distribution of atmMOB, as well as to the potential influence of microbial atm CH4 oxidation, in the context of regional CH4 flux models and global warming.

Utilization of fluorescent microspheres and a green fluorescent protein-marked strain for assessment of microbiological contamination of permafrost and ground ice core samples from the Canadian High Arctic.

Fluorescent microspheres were applied in a novel fashion during subsurface drilling of permafrost and ground ice in the Canadian High Arctic to monitor the exogenous microbiological contamination of core samples obtained during the drilling process. Prior to each drill run, a concentrated fluorescent microsphere (0.5-microm diameter) solution was applied to the interior surfaces of the drill bit, core catcher, and core tube and allowed to dry. Macroscopic examination in the field demonstrated reliable transfer of the microspheres to core samples, while detailed microscopic examination revealed penetration levels of less than 1 cm from the core exterior. To monitor for microbial contamination during downstream processing of the permafrost and ground ice cores, a Pseudomonas strain expressing the green fluorescent protein (GFP) was painted on the core exterior prior to processing. Contamination of the processed core interiors with the GFP-expressing strain was not detected by culturing the samples or by PCR to detect the gfp marker gene. These methodologies were quick, were easy to apply, and should help to monitor the exogenous microbiological contamination of pristine permafrost and ground ice samples for downstream culture-dependent and culture-independent microbial analyses.

Glide: a new approach for rapid, accurate docking and scoring. 2. Enrichment factors in database screening.

Glide's ability to identify active compounds in a database screen is characterized by applying Glide to a diverse set of nine protein receptors. In many cases, two, or even three, protein sites are employed to probe the sensitivity of the results to the site geometry. To make the database screens as realistic as possible, the screens use sets of "druglike" decoy ligands that have been selected to be representative of what we believe is likely to be found in the compound collection of a pharmaceutical or biotechnology company. Results are presented for releases 1.8, 2.0, and 2.5 of Glide. The comparisons show that average measures for both "early" and "global" enrichment for Glide 2.5 are 3 times higher than for Glide 1.8 and more than 2 times higher than for Glide 2.0 because of better results for the least well-handled screens. This improvement in enrichment stems largely from the better balance of the more widely parametrized GlideScore 2.5 function and the inclusion of terms that penalize ligand-protein interactions that violate established principles of physical chemistry, particularly as it concerns the exposure to solvent of charged protein and ligand groups. Comparisons to results for the thymidine kinase and estrogen receptors published by Rognan and co-workers (J. Med. Chem. 2000, 43, 4759-4767) show that Glide 2.5 performs better than GOLD 1.1, FlexX 1.8, or DOCK 4.01.

Natural killer cell activity in schizophrenia and schizoaffective disorder: a pilot study.

Natural killer cell activity was prospectively studied in 15 patients with chronic schizophrenia and in seven patients with schizoaffective disorder, depressed type. These patients were compared to individually matched normal controls. No mean differences in natural killer cell activity between the patient groups and their controls were observed.

Primary health care in the CMHC: a role for the nurse practitioner.

Although persons with chronic mental illness have a high incidence of physical health problems, they are often ill equipped to seek care within complex health care systems and tend to depend on community mental health centers as their only source of regular health care. The authors describe a role for the nurse practitioner in assessing the medical needs of chronic mentally ill outpatients at a community mental health center and in devising strategies to meet those needs. The nurse practitioner's activities include direct physical health screening and treatment, referral for specialized medical services, consultation, research, and staff and patient education.

Limbic-hypothalamic-pituitary-adrenal axis activity and ventricular-to-brain ratio studies in affective illness and schizophrenia.

Some investigators have speculated that structural brain alterations observed in some psychiatric patients might be related to increased limbic-hypothalamic-pituitary-adrenal axis (LHPA) activity. To explore this hypothesis, we prospectively studied 166 research volunteers (19 patients with research diagnostic criteria (RDC) major depression, 9 patients with RDC bipolar depression, 45 patients with RDC schizophrenia, and 94 RDC normal controls), examining the relationship between magnetic resonance image-determined ventricular-to-brain ratio (VBR) and indices of LHPA axis function (cerebrospinal fluid (CSF) corticotropin-releasing factor (CRF), CSF adrenocorticotropic hormone (ACTH), and 24-hour urinary-free cortisol secretion). We observed no significant differences in mean VBR among the three patient groups and the normal control volunteers. Of the indices of LHPA activity, only CSF CRF concentrations distinguished the four subject groups, with CSF CRF being significantly elevated in the more severely depressed major depression patients. Indices of LHPA activity were not significantly correlated with VBR in any of the three patient groups or in the normal volunteers. These preliminary results suggest that VBR is not highly associated with alterations in LHPA activity, at least as determined cross-sectionally. Further longitudinal studies with reference to diagnostic subtypes, severity, symptom profiles, and more specific neuroanatomic regions may allow the elucidation of possible relationships between LHPA pathology and structural brain alterations.

Lateral ventricle-brain ratio and balance between CSF HVA and 5-HIAA in schizophrenia.

OBJECTIVE: Lateral ventricle enlargement in schizophrenia has been positively correlated with poor premorbid competence, negative symptoms, and poor treatment response and negatively correlated with concentrations of homovanillic acid (HVA), a dopaminergic metabolite. The authors provide further evidence of a reciprocal relationship between lateral ventricle size and dopaminergic activity in schizophrenia. METHOD: They assessed the relationship between lateral ventricle enlargement (ventricle-brain ratio, VBR) and CSF neurotransmitter metabolite concentrations (HVA and 5-hydroxyindoleacetic acid [5-HIAA]) in 45 patients with schizophrenia, 28 with affective disorders (19 patients with major depression and nine with bipolar disorder), and 91 normal comparison subjects. RESULTS: No group mean differences were significant. Although individual correlations of VBR with HVA and 5-HIAA were not statistically significant, the ratio of HVA to 5-HIAA was significantly correlated with VBR in the patients with schizophrenia, a finding consistent with dopaminergic-serotonergic balance hypotheses. CONCLUSIONS: These data suggest that it is the balance between HVA and 5-HIAA rather than their absolute levels which is associated with brain morphology and that this relationship between brain chemistry and morphology may be characteristic of the normal range of functioning for these systems. In other words, independent of whether brain morphology and chemistry differentiate psychopathological from nonpsychopathological states, there may be an orderly relationship between lateral ventricle size and the balance between HVA and 5-HIAA balance that is especially prominent in schizophrenia.

Assessment of psychosocial functioning of patients with sickle cell disease.

The Chronic Illness Problem Inventory (CIPI) was used to assess level of psychosocial functioning in 89 patients with sickle cell disease. The results indicated that sickle cell patients have significant psychosocial distress in the areas of employment and finances, sleeping and eating, and performance of normal daily activities. Fear and anxiety regarding body deterioration, and lack of assertiveness in social relationships were also found. These findings suggest that depression may be a common problem among sickle cell patients. Treatment alternatives that address these areas are reviewed.

Direct observation of the femtosecond excited-state cis-trans isomerization in bacteriorhodopsin.

Femtosecond optical measurement techniques have been used to study the primary photoprocesses in the light-driven transmembrane proton pump bacteriorhodopsin. Light-adapted bacteriorhodopsin was excited with a 60-femtosecond pump pulse at 618 nanometers, and the transient absorption spectra from 560 to 710 nanometers were recorded from -50 to 1000 femtoseconds by means of 6-femtosecond probe pulses. By 60 femtoseconds, a broad transient hole appeared in the absorption spectrum whose amplitude remained constant for about 200 femtoseconds. Stimulated emission in the 660- to 710-nanometer region and excited-state absorption in the 560- to 580-nanometer region appeared promptly and then shifted and decayed from 0 to approximately 150 femtoseconds. These spectral features provide a direct observation of the 13-trans to 13-cis torsional isomerization of the retinal chromophore on the excited-state potential surface. Absorption due to the primary ground-state photoproduct J appears with a time constant of approximately 500 femtoseconds.

Bacteriorhodopsin's L550 intermediate contains a C14-C15 s-trans-retinal chromophore.

Conformational changes of the retinal chromophore about the C14-C15 bond in bacteriorhodopsin (BR) have been proposed in models for the mechanism of light-driven proton transport. To determine the C14-C15 conformation in BR's L550 intermediate, we have examined the resonance Raman spectra of BR derivatives regenerated with retinal deuterated at the 14 and 15 positions. Vibrational calculations show that the C14-2H and C15-2H rocking modes form symmetric (A) and antisymmetric (B) combinations in [14,15-2H]retinal chromophores. When there is a trans conformation about the single bond between C14 and C15 (14-s-trans), a small frequency separation or splitting is observed between the A and B modes, which are found at approximately equal to 970 cm-1. In 14-s-cis molecules, the splitting is large, and the Raman-active symmetric A mode is predicted at approximately equal to 850 cm-1. In addition, the monodeuterium rock should appear at an unusually low frequency (920-930 cm-1) in the 14-2H-labeled 14-s-cis molecules. These patterns are insensitive to computational details: similar results are predicted by a modified Urey-Bradley force field and by MNDO (modified neglect of differential overlap) calculations for twisted chromophores and for highly delocalized protonated Schiff base cations. Time-resolved resonance Raman spectra were obtained of BR's L550 intermediate regenerated with [14-2H]-, [15-2H]- and [14,15-2H]retinal. The symmetric A rock in L550 is found at 968 cm-1, within 4 cm-1 of the frequencies for the monodeuterio derivatives, and no scattering is observed between 800 and 940 cm-1. The rocking frequencies of deuterated L550 are within 5 cm-1 of those observed in BR568, which contains a 14-s-trans chromophore. These results show that L550 contains a 14-s-trans chromophore and suggest that only 14-s-trans structures are involved in the proton pumping photocycle of BR.

Isolated chylopericardium after cardiac operations.

Case histories are reported of four patients having chylopericardium following cardiac operations. This entity can be recognized by noting the presence of postprandial milky mediastinal drainage that stains positive for fat with Sudan III. Chylopericardium is caused by operative injury to the thoracic duct, by operative injury to tributaries of the thoracic duct, or by thrombosis at the confluence of the left subclavian and jugular veins with subsequent obstruction of thoracic duct drainage. Appropriate management, which may be either conservative or operative, depends upon the volume and duration of drainage. The conservative approach entails adequate pericardial drainage and institution of a medium-chain triglyceride diet; operative therapy entails ligation of the thoracic duct low in the posterior mediastinum.

Combined synchronous abdomino-vaginal operation in management of recurrent urinary stress incontinence.

A synchronous combined abdomino-vaginal repair operation is described which enables adequate mobilisation and subsequent fixation of the urethro-vesical junction with accurate insertion of supporting stitches. This procedure is of great value in the management of patients with previous failed anterior colporrhaphy for stress incontinence.

The Sickness Impact Profile: reliability of a health status measure.

This report describes the results of research conducted on the reliability of the Sickness Impact Profile (SIP). The SIP is a questionnaire instrument designed to measure sickness-related behavioral dysfunction and is being developed for use as an outcome measure in the evaluation of health care. The test-retest reliability of the SIP in terms of several reliability measures was investigated using different interviewers, forms, administration procedures, and a variety of subjects who differed in terms of type and severity of dysfunction. The results provided evidence for the feasibility of collecting reliable data using the SIP under these various conditions. In addition, subject variability in relation to reliability is discussed.