Is there a relationship between delta sleep at night and afternoon cerebral blood flow, assessed by HMPAO-SPECT in depressed patients and normal control subjects? Preliminary data

We wished to explore the relationships between waking HMPAO uptake and visually scored polysomnography. We hypothesized that HMPAO activity would correlate positively with slow wave sleep measures the same night. Eight unmedicated unipolar patients with current DSM-IV major depression (17-item Hamilton Depression Rating Scale score 21.5+/-2.9) and seven control subjects received polysomnography on 2 consecutive nights. On the afternoon following the adaptation night, subjects received cerebral SPECT, with 15 mCi Tc-99m-HMPAO injected while subjects performed the Continuous Performance Task. Patients and control subjects did not significantly differ on demographic, polysomnographic, and SPECT variables. Slow wave sleep measures correlated positively (Spearman's) with global and regional tracer activity for depressed (n = 8), control (n = 7) and combined groups (n = 15); in other words, the greater the global or regional afternoon HMPAO uptake, the greater the slow wave sleep measures were the same night. In addition, the greater the waking afternoon global or regional HMPAO activity, the faster subjects fell asleep and the less Stage 2% they had. In patients, global and regional HMPAO activity correlated positively with REM density. Positive correlations between waking tracer activity and subsequent slow wave measures are consistent with previous hypotheses linking slow wave sleep with brain energy conservation and restoration. Further study is needed to determine whether these functional relationships differ in depression.

1H MRS in acute traumatic brain injury

The objective of this study was to demonstrate 1H MR spectroscopy (MRS) changes in cerebral metabolites after acute head trauma. Twenty-five patients (12 children, 13 adults) were examined with quantitative 1H MRS after closed head injury. Clinical grade (Glasgow Coma Scale [GCS]) and outcome (Rancho Los Amigos Medical Center Outcome Score [ROS]) were correlated with quantitative neurochemical findings. N-acetylaspartate (NAA), a neuronal and axonal marker, was reduced (P < .03-.001). In children, a reduced NAA/creatine plus phosphocreatine (Cr) level and the presence of detectable lipid/lactate predicted bad outcome (sensitivity, 89%; specificity, 89%). The first MRS examination of all patients correlated with ROS versus NAA (r = .65, P < .0001). Although most patients showed MRS abnormalities, striking heterogeneity of 1H MRS characterized the individual patients. 1H MRS identifies multiple patterns of diffuse brain injury after blunt head trauma. There was a strong correlation between MRS and outcome. Future prospective studies will be needed to determine the clinical usefulness of MRS in predicting outcome from closed head injury.

Rapid tryptophan depletion, sleep electroencephalogram, and mood in men with remitted depression on serotonin reuptake inhibitors

BACKGROUND

In previous studies, depletion of brain serotonin by administration of a tryptophan-free amino acid drink (TFD) (1) temporarily reversed the antidepressant effects of selective serotonin reuptake inhibitors (SSRIs) in euthymic patients who had a history of major depression, and (2) enhanced rapid eye movement (REM) sleep in normal volunteers. In this study, we hypothesized that the TFD would not only increase depressive symptoms but also the propensity for REM sleep in euthymic patients treated with SSRIs.

METHODS

Ten fully remitted, medicated male patients who had a history of major depressive episode ingested a 100-g TFD (the experimental dose) or a 25-g TFD (designed to be the control drink) in double-blind, random order on separate days. The effects were assessed with mood ratings, plasma tryptophan concentrations, and an all-night sleep electroencephalogram.

RESULTS

The TFDs produced a dose-dependent reduction in plasma tryptophan concentrations, sleep latency, and REM latency, as well as increased REM percentage, REM minutes, REM density, and total sleep time. Neither strength of TFD altered mood to a clinically significant degree.

CONCLUSIONS

Although the TFD affected plasma tryptophan concentrations and various sleep measures, our study did not confirm previous reports that TFD temporarily reversed the antidepressant effects of SSRIs in euthymic patients. Our patients, however, had been treated for a longer period with SSRIs and were more fully remitted at the time of the study. Our results suggest that TFD-induced relapse in SSRI-treated patients in remission decreases as a function of treatment duration, degree of remission, or both.

The use of an oligonucleotide that hybridizes to DNA sequences interspersed in the genome of members of the genus Phytophthora as an adjunct to morphological criteria in species identification

An oligonucleotide (primer), designed from a conserved region of the multi-allelic b locus of the basidiomycete fungus Ustilago maydis, generated reproducible PCR fingerprints in Phytophthora species. The primer hybridized in a species-specific manner to nucleotide sequences interspersed in the genome of the closely related members of Phytophthora taxonomic group IV. We recommend the use of this PCR procedure as an alternative method for resolving the close taxonomic affinity of some members of the genus Phytophthora.

The gastric bubble: medicine, magic or mania?

This paper is presented to acquaint the GIA with a new medical procedure that is rapidly gaining popularity throughout the United States. It includes a brief discussion of the medical device itself and the technique of implantation as well as indications and contraindications for its use. In addition, an overview of the program developed at Placentia-Linda Community Hospital, Placentia, CA, is offered. Personal reflections are also rendered regarding the unique nursing opportunities afforded by this procedure and its accompanying follow-up program. In conclusion, this paper will substantiate, with personal experience and early supportive research data, the parallels between the medicinal value, the magic, and the mania accompanying the Gastric Bubble.

Effects of a tryptophan-free amino acid drink challenge on normal human sleep electroencephalogram and mood

BACKGROUND

Serotonin has been implicated in the regulation of sleep and mood. In animals a tryptophan-free amino acid drink (TFD) challenge has been found to reduce brain serotonin. We hypothesized this TFD would produce alterations in electroencephalographic (EEG) sleep commonly associated with depression, i.e. an enhancement of rapid eye movement (REM) sleep, and adversely affect mood ratings in humans.

METHODS

We investigated the effects of a TFD challenge in 11 healthy male subjects on EEG sleep and mood (assessed by Profile of Mood States). All subjects received on separate occasions an experimental drink containing approximately 100 g of an amino acid mixture (100% TFD) and a control drink containing one fourth strength (25% TFD) of the experimental drink 5 hours prior to sleep (6:00 PM).

RESULTS

Both drinks significantly decreased plasma tryptophan levels 5 hours postchallenge (11:00 PM). Both drinks significantly decreased REM latency, and the 25% TFD also increased REM time and REM% compared to baseline. No significant changes were found in subjective ratings of depression; however, subjects reported confusion and tension and a decrease in elation, vigor, and friendliness compared with baseline.

CONCLUSIONS

These TFD findings further support the involvement of serotonin deficiency in EEG sleep findings commonly seen in depression.

Measurement of gastric mucosal carbon dioxide tension by saline and air tonometry

PURPOSE

This study compares the balloon air tonometry method of measuring gastric mucosal CO2 to standard saline tonometry. Also, this study investigates the effect of histamine-2 receptor blockade on the precision of tonometric measures of gastric mucosal PCO2 (PtCO2).

MATERIALS AND METHODS

We obtained hourly measurements of PtCO2 from two gastric tonometers inserted orally in 19 healthy volunteers. One tonometer measured PtCO2 by the intermittent saline method, whereas the other measured PtCO2 using a newer continuous air method. Subjects received intravenous 5% dextrose during the first 6 hours of the experiment followed by a continuous infusion of a solution of ranitidine in 5% dextrose for another 6 hours. The ranitidine infusion was titrated to maintain gastric fluid pH > or = 4.

RESULTS

Comparison of air to saline tonometry yielded a bias of -1.3 mm Hg with a limit of agreement of 6.6 mm Hg under optimal conditions of optimal gastric fluid pH (gastric fluid pH > or = 5.0). Measures of PtCO2 were lower with ranitidine for either group, 45.3 +/- 1.3 mm Hg versus 39.7 +/- 0.5 mm Hg for saline (P < .01) and 45.9 +/- 1.0 versus 41.3 +/- 0.5 for air (P < .01). The mean PCO2 gap (PtCO2-P(arterial)CO2) at gastric fluid pH > or = 5.0 was 1.4 mm Hg, with a standard deviation of 2.7 mm Hg. A span of three standard deviations yields a normal limit for PCO2 gap of 9.5 mm Hg.

CONCLUSION

Measures of PtCO2 with the air tonometer method are similar to those obtained with saline tonometry. The reliability of PtCO2 measurements with either method improved with the use of ranitidine to maintain gastric fluid pH > or = 5.

Characterizing the coherence of Bose-Einstein condensates and atom lasers

For a dilute, interacting Bose gas of magnetically-trapped atoms at temperatures below the critical temperature T0 for Bose-Einstein condensation, we determine the second-order coherence function g (2) (r1 ; r2) within the framework of a finite-temperature quantum field theory. We show that, because of the different spatial distributions of condensate and thermal atoms in the trap, g (2) (r1 ; r2) does not depend on jr1 r2j alone. This means that the experimental determinations of g (2) reported to date give only its spatial average. Such an average may underestimate the degree of coherence attainable in an atom laser by judicious engineering of the output coupler.

Health promotion and screening services reported by older adult patients of urban primary care physicians

BACKGROUND

Adult preventive services provided at intervals recommended by expert panel guidelines may reduce morbidity and mortality. As part of an intervention trial to increase primary preventive services in urban primary care practices, baseline data were collected on primary prevention and screening test rates in older adults and on patient characteristics associated with provision of these services.

METHODS

A questionnaire on preventive services offered or provided over the past 2 years was completed by patients aged 52 to 77 years and another by their 42 participating physicians. Logistic regression was used to identify patient characteristics associated with increased provision of these services.

RESULTS

Usable questionnaires were completed by 1457 (80.9%) patients. Patient age and sex were not associated with the provision of primary preventive and counseling services. The presence of two or more chronic diseases was predictive of primary preventive services (P < .02), but was not associated with an increase in screening tests or procedures. Age was positively associated with delivery of prostate-specific antigen blood tests (P < .001) and rectal examinations (P < .001) in men, but was negatively associated with mammography (P < .001) and Papanicolaou (Pap) tests (P = .02) in women. The negative trend in screening mammography was evident even for women aged 50 to 65 years despite the national consensus regarding the benefits of screening for this age group. Patients with health management organization insurance reported significantly more mammography (P = .002), cervical Pap tests (P = .050), sigmoidoscopies (P = .002), and fecal occult blood tests (P = .035).

CONCLUSIONS

In our study patients, the provision of primary preventive and screening services was closer to consensus guidelines than is typically reported in the literature. The data suggest that future investigations and interventions to improve primary prevention and screening services in older adults who have access to primary care do not need to be directed at fundamental changes in the way preventive services are delivered, but rather should target procedures of proven benefit, such as mammography, where rates remain below recommended guidelines.

Differential effects on TNF alpha production by pharmacological agents with varying molecular sites of action

This study describes the activation conditions for tumor necrosis factor-alpha (TNF alpha) production in myelomonocytic U937 cells and human primary peripheral blood monocytes in response to lipopolysaccharide (LPS) and/or phorbol 12-myristate 13-acetate (PMA). PMA itself induced only low levels of TNF alpha production with delayed kinetics (e.g. 0.758 +/- 0.128 ng/ml from U937 cells after 48 h) while LPS induced greater levels of TNF alpha production in less time (e.g. 2.083 +/- 0.96 ng/ml from monocytes in 24 h). Pharmacological agents with various molecular sites of action were used to validate the two systems, with the protein serine-threonine kinase inhibitors staurosporine and Ro-31-8220, the protein tyrosine kinase inhibitor herbimycin A (HBA) and dexamethasone exhibiting the greatest potency (IC50S 5-350 nM). In contrast to the effect on TNF alpha production, PMA induced strong phosphorylation/activation of p42/p44mapk in monocytes by 10 min determined in a mobility shift assay, while LPS was a weaker inducer. Additionally, staurosporine (to LPS and PMA) and HBA (to LPS only) inhibited the activation of these mitogen-activated protein kinase (MAPK) isoforms at doses 10-100 fold higher than those required to inhibit maximal TNF alpha production. These data indicate the involvement of the p42/p44mapk signalling pathway in LPS-induced pro-inflammatory cytokine production but suggest that other signalling pathways are also implicated in this phenomenon.

Assessment of CSF levels of tau protein in mildly demented patients with Alzheimer's disease

CSF levels of tau protein are increased in many patients with Alzheimer's disease (AD). Studies disagree on whether the increase is found in moderate or severe AD to a greater extent than in mild AD, and in two reports there was an inverse correlation between tau levels and cognitive scores. To readdress this question, we measured CSF tau in a group of mildly impaired patients with AD (Mini-Mental State Examination [MMSE] scores > or =20/30) and compared their tau levels with those in age-comparable normal and neurologic controls. We found that the mean level of CSF tau was significantly increased in the AD group compared with the controls, and 29 of 36 patients with AD had levels that exceeded a cutoff determined in a previous study. CSF tau levels did not correlate with MMSE scores. These findings and those of previous studies show that elevated CSF tau levels are found in most patients with AD, occur early in the course of dementia, and may be useful in supporting the diagnosis of AD.

Sharing the experience

The Nurses' Work Experience of the Collaborative Nursing Program at North Island College is helping to prepare students to face the challenges of the new health care. Moreover, it is helping practicing nurses recognize the valuable role they can play in students' initial experiences with nurses' work.

The Genome Sequence DataBase version 1.0 (GSDB): from low pass sequences to complete genomes

The Genome Sequence DataBase (GSDB) has completed its conversion to an improved relational database. The new database, GSDB 1.0, is fully operational and publicly available. Data contributions, including both original sequence submissions and community annotation, are being accomplished through the use of a graphical client-server interface tool, the GSDB Annotator, and via GIO (GSDB Input/Output) files. Data retrieval services are being provided through a new Web Query Tool and direct SQL. All methods of data contribution and data retrieval fully support the new data types that have been incorporated into GSDB, including discontiguous sequences, multiple sequence alignments, and community annotation.