Comparative study of sleep and circadian rhythms in patients presenting unipolar or bipolar major depressive episodes

Currently, there is a major challenge in distinguishing between unipolar and bipolar major depressive episode. A significant body of research has been dedicated to identifying biomarkers that can aid in this differentiation due to its crucial implications, particularly for therapeutic and prognostic purposes. Among the biomarkers of interest, markers related to sleep and circadian rhythms show promise and could potentially aid in making this distinction. Nevertheless, no study has simultaneously examined sleep-wake disorders, circadian rhythms, and seasonal patterns using both subjective and objective measures. This study aims to characterize and compare the sleep-wake and rhythm disorders including patients with unipolar major depressive episode (n = 72) and with bipolar major depressive episode (n = 43) using both subjective markers (using self-report questionnaires and sleep complaints) and objective markers (using actigraphy). Patients with unipolar major depressive episode seem to experience significantly poorer quality of sleep, more symptoms of insomnia and lower sleep efficiency compared to patients with bipolar major depressive episode. On the other hand, patients with bipolar major depressive episode exhibit significantly more symptoms of motor retardation and hypersomnia compared to patients with unipolar disorder. These results hold significant implications for identifying individuals with unipolar major depressive episode or bipolar major depressive episode using sleep and circadian markers, and for developing recommended and personalized therapeutic strategies.

Images: "Too much heat for my non-24-hour sleep-wake disorder!" A case report

The non-24-hour sleep-wake disorder (N24SWD) is a rare condition, sometimes associated with blindness or with suprachiasmatic nuclei lesions, resulting in a free-running rhythm or hypernycthemeral syndrome. Synchronizers, such as light, when light perception remains, melatonin, food intakes, physical activity, social interactions, and temperature, play a key role in the treatment of N24SWD. In this report, we describe a case illustrating the impact of outdoor temperature in a 34-year-old man with N24SWD effectively treated through a combination of chronotherapy interventions. During 3 consecutive heat waves, he experienced a recurrence of his natural 25.5-hour free-running rhythm, with a consistent bedtime phase delay caused by temperature, resulting in the discontinuation of chronotherapy. After these heat waves, he was able again to resynchronize his rhythms with the combination of chronotherapeutics. This case report highlights that patients with N24SWD may be particularly at risk of relapse during heat waves, with direct implications for monitoring and reinforcing chronotherapies.

CITATION

Garrivet J, d'Ortho M-P, Frija-Masson J, et al. "Too much heat for my non-24-hour sleep-wake disorder!" A case report. J Clin Sleep Med. 2024;20(2):329-333.

How Can Digital Mental Health Enhance Psychiatry?

The use of digital technologies is constantly growing around the world. The wider-spread adoption of digital technologies and solutions in the daily clinical practice in psychiatry seems to be a question of when, not if. We propose a synthesis of the scientific literature on digital technologies in psychiatry and discuss the main aspects of its possible uses and interests in psychiatry according to three domains of influence that appeared to us: 1) assist and improve current care: digital psychiatry allows for more people to have access to care by simply being more accessible but also by being less stigmatized and more convenient; 2) develop new treatments: digital psychiatry allows for new treatments to be distributed via apps, and practical guidelines can reduce ethical challenges and increase the efficacy of digital tools; and 3) produce scientific and medical knowledge: digital technologies offer larger and more objective data collection, allowing for more detection and prevention of symptoms. Finally, ethical and efficacy issues remain, and some guidelines have been put forth on how to safely use these solutions and prepare for the future.

Major depressive episode with insomnia and excessive daytime sleepiness: A more homogeneous and severe subtype of depression

Previous studies have noted the crucial role of excessive daytime sleepiness (EDS) in the course of depressive illness, and more recently, a few studies documented its strong associations with an increased risk of suicide. While insomnia is associated with heightened emotional reactivity, suicidal behaviors, and increased relapses and recurrence. Our main hypothesis is that major depressive episodes (MDE) with insomnia and EDS are associated with more severe manifestations of depression. However, to date, no study has directly compared MDE with insomnia without EDS (Ins), and MDE with insomnia with EDS (InsEDS) using both subjective biomarkers (administration of self-assessment questionnaires for psychiatric evaluation and sleep complaints) and objective biomarkers (of sleep and circadian rhythms (using actigraphy). The InsEDS group, compared to the Ins group, exhibited significantly increased suicidal ideation, larger seasonal impacts on mood, alterations in sleep duration, weight, appetite, energy levels, and social activities throughout the year. Furthermore, they had significant delayed onset of daily activity measured with actigraphy. These findings provided new insights into the link between suicide, sleep, alertness, and biological clock. They also hold significant implications for identifying individuals with more severe depressive manifestations and for developing tailored and personalized therapeutic strategies.

Predictors of cognitive behavioral therapy for insomnia (CBT-I) effects in insomnia with major depressive episode

Insomnia plays a critical role in the onset and maintenance of Major Depressive Episode (MDE). Cognitive behavioral therapy for insomnia (CBT-I) can successfully improve the sleep of patients with insomnia and MDE. Nonetheless, the factors influencing CBT-I's effects in MDE remain uncertain. This study aimed to identify predictors of insomnia improvement following CBT-I, as well as predictors of insomnia response, remission in patients with MDE and specific insomnia subtypes. Initially, we compared a 4-session weekly CBT-I treatment to baseline sleep education (SE) in a control group. This confirmed CBT-I's positive effects and the need to explore predictive factors. Notably, treatment-resistant depression (TRD) predicted reduced insomnia severity with CBT-I. Patients exhibiting seasonal fluctuations in depressive symptoms and sleep patterns throughout the year, or having daytime dysfunction, experienced enhanced CBT-I efficacy, especially for early awakenings insomnia. Conversely, shorter sleep duration predicted a less favorable response to CBT-I, less improvement in daytime dysfunction and sleep disturbance worries. Additionally, MDE with suicide attempts predicted a poorer improvement of daytime dysfunction. Further research is essential to comprehensively grasp the mechanisms behind CBT-I's heightened effectiveness in MDE patients with TRD and seasonal fluctuations.

The nightmare severity index (NSI): A short new multidimensional tool for assessing nightmares

This psychometric pilot study aims to evaluate a new multidimensional simple scale, named the nightmare severity index (NSI) - close to the existing insomnia (ISI) and hypersomnia (HSI) severity indexes. The NSI encompasses all main dimensions of nightmare disorder, evaluating four subdimensions: frequency, emotional impact, diurnal impact, and nocturnal impact of nightmares. The NSI was completed by a total of 102 patients. The majority of the population consisted of women (64%) and outpatient individuals (76%) diagnosed with mood disorders such as depression (31%) and bipolar disorder (41%). Comorbidity with post-traumatic stress disorder (PTSD) was prevalent (44%), and psychotropic medications were commonly used (47%). Internal validity analyses indicated that the NSI was well suited for exploratory factor analysis. All items demonstrated satisfactory correlations with the factors, and the questionnaire exhibited good internal consistency (Cronbach's alpha >0.7). Higher NSI scores were observed among individuals experiencing nightmare symptoms considering the DSM-5/ICSD-3 criteria. In summary, the NSI proves to be a promising and valuable tool for clinical practice, demonstrating good acceptability, internal validity, and the ability to assess nightmare severity.

Effect of lockdown on sleep-wake rhythm and alcohol use

The global covid-19 pandemic has imposed radical changes in daily lives. This study reflects upon sociodemographic and clinical characteristics (sleep-wake rhythm, psychiatric symptoms, and alcohol use behavior) during the full lockdown, comparing individuals who increased their alcohol use (iAU), those who maintained a stable use (sAU), and those who did not consume alcohol (AnoU). Participants were recruited via e-mails and they were required to complete an online survey that included questionnaires, during the last week of the full lockdown. The iAU group, compared to the sAU group, presented more disturbed sleep (PSQI; p < .001), more severe insomnia (ISI; p < .001), shorter sleep duration (p < .001), longer sleep latency (p < .001), and less regular sleep-wake schedules (p = .005). They also reported more anxiety (HAD-A; p = .009), more depressive symptoms (HAD-D: p = .006) and more psychotraumatic symptoms (PCL-5: p = .018). Moreover, the sAU group, compared to AnoU, showed better quality of sleep (PSQI; p = .002) and less severe anxiety symptoms (HAD-A; p = .014). Maintaining a stable use was also related to a better quality of life associated with bigger homes with more frequent outdoors living spaces and higher monthly incomes. Individuals who increased their alcohol consumption during the Covid-19 lockdown exhibited more sleep and circadian rhythm disturbances, as well as more (severe) psychiatric symptoms.

Quantitative SPECT/CT parameters of myocardial 99mTechnetium-3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) uptake in suspected cardiac transthyretin amyloidosis

Background

^99mTc-labelled bisphosphonates are used for imaging assessment of patients with transthyretin cardiac amyloidosis (ATTR). Present study evaluates whether quantitative SPECT/CT measurement of absolute myocardial ^99mTc-labelled 3,3-diphosphono-1,2-propanodicarboxylic acid (Tc-DPD) uptake can diagnose patients with suspected ATTR.

Methods

Twenty-eight patients (25 male, age 80.03 ± 6.99 years) with suspected ATTR referred for Tc-DPD imaging had planar and SPECT/CT imaging of the chest. Three operators independently obtained Tc-DPD myocardial SUVmax and SUVmean above threshold (SMaT) (20, 40 and 60% of SUVmax), using a semi-automated threshold segmentation method. Results were compared to visual grading (0–3) of cardiac uptake.

Results

Twenty-two patients (78%) had cardiac uptake (2 grade 1, 15 grade 2, 5 grade 3). SUVmax and SMaT segmentation thresholds enabled separating grades 2/3 from 0/1 with excellent inter- and intra-reader correlation. Cut-off values 6.0, 2.5, 3 and 4 for SUVmax, SMaT_20,40,60, respectively, separated between grades 2/3 and 0 /1 with PPV and NPV of 100%. SMaT_20,40,60(cardiac)/SUVmean (liver) and SMaT_20,40,60(cardiac)/SUV_mean(liver/lung) separated grades 2 and 3.

Conclusion

Quantitative SPECT/CT parameters of cardiac Tc-DPD uptake are robust, enabling separation of patients with grades 2 and 3 cardiac uptake from grades 0 and 1. Larger patient cohorts will determine the incremental value of SPECT/CT quantification for ATTR management.

Prospective assessment of disease-specific quality of life in adults with eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is an important cause of upper gastrointestinal dysfunction in children and adults. The EoE-quality of life (QOL)-A was validated as a disease-specific measure of quality of life in EoE. This study characterized the extent of QOL concerns in a cohort of adult EoE patients and delineated the relationships between QOL and other disease activity measures. One hundred sixty-seven patients enrolled in this prospective cohort study. Patients with established and suspected EoE undergoing endoscopy at a single university-based medical center were recruited. EoE was diagnosed on the basis of the clinical criteria and histologic demonstration of ≥15 eos/hpf while on proton pump inhibition therapy. Sixty five patients undergoing repeat endoscopy during the enrollment period participated twice. Patients provided demographic information and completed symptom assessments and the EoE-QOL-A. Analyses included comparisons with overall QOL as well as QOL subscales. Outcome measures included endoscopic activity using a validated instrument, the EoE Endoscopic Reference Score, and histology. Overall QOL was significantly correlated with dysphagia frequency, intensity, and severity (P < 0.001). Patients who experienced a food impaction in the last 30 days had significantly worse overall QOL (P = 0.009). There was no correlation between overall QOL and years since diagnosis, symptom duration, endoscopic features, or histologic findings. Patient symptoms correlated with endoscopic features of edema, rings, and stricture severity. Histologic activity was highly correlated with severity of endoscopic features. Patients who underwent repeat endoscopy with histologic response demonstrated improved eating and social QOL; however, overall QOL was unchanged. In adults with EoE, patient reported QOL is associated with symptom severity but not endoscopic or histologic features. Disease-specific QOL may complement parameters of biologic activity in the assessment of overall disease burden in EoE.

Systematic review: methodological flaws in racial/ethnic reporting for gastroesophageal reflux disease

Health care disparities affecting the care of multiple disease groups are of growing concern internationally. Research guidelines, governmental institutions, and scientific journals have attempted to minimize disparities through policies regarding the collection and reporting of racial/ethnic data. One area where shortcomings remain is in gastroesophageal reflux disease (GERD). This systematic review, which adheres to the PRISMA statement, focuses on characterizing existing methodological weaknesses in research focusing on studies regarding the assessment, prevalence, treatment, and outcomes of GERD patients. Search terms included GERD and typical symptoms of GERD in ethnic groups or minorities. We reviewed 62 articles. The majority of studies did not report the race/ethnicity of all participants, and among those who did, very few followed accepted guidelines. While there were diverse participants, there was also diversity in the manner in which groups were labeled, making comparisons difficult. There appeared to be a disparity with respect to countries reporting race/ethnicity, with certain countries more likely to report this variable. Samples overwhelmingly consisted of the study country's majority population. The majority of studies justified the use of race/ethnicity as a study variable and investigated conceptually related factors such as socioeconomic status and environment. Yet, many studies wrote as if race/ethnicity reflected biological differences. Despite recommendations, it appears that GERD researchers around the world struggle with the appropriate and standard way to include, collect, report, and discuss race/ethnicity. Recommendations on ways to address these issues are included with the goal of preventing and identifying health care disparities.

Reed-Sternberg cells in Hodgkin's lymphoma present features of cellular senescence

Hodgkin's Lymphoma (HL) is one of the most prevailing malignancies in young adults. Reed–Sternberg (RS) cells in HL have distinctive large cell morphology, are characteristic of the disease and their presence is essential for diagnosis. Enlarged cells are one of the hallmarks of senescence, but whether RS cells are senescent has not been previously investigated. Here we show that RS cells have characteristics of senescent cells; RS cells in HL biopsies specifically express the senescence markers and cell cycle inhibitors p21^Cip1 and p16^INK4a and are negative for the proliferation marker Ki-67, suggesting that these cells have ceased to proliferate. Moreover, the RS-like cells in HL lines, stained specifically for senescence-associated β-galactosidase (SA-β-gal). Oxidative stress promoted senescence in these cells as demonstrated by their staining for p21^Cip1, p16^INK4a, p53 and γH2AX. Senescent cells produce copious amounts of inflammatory cytokines termed ‘senescence-associated secretory phenotype' (SASP), primarily regulated by Nuclear Factor κB (NF-κB). Indeed, we show that NF-κB activity and NF-κB-dependent cytokines production (e.g., IL-6, TNF-α, GM-CSF) were elevated in RS-like cells. Furthermore, NF-κB inhibitors, JSH-23 and curcumin reduced IL-6 secretion from RS-like cells. Thus, defining RS cells as senescent offers new insights on the origin of the proinflammatory microenvironment in HL.

Effect of propofol on the medial temporal lobe emotional memory system: a functional magnetic resonance imaging study in human subjects

BACKGROUND

Subclinical doses of propofol produce anterograde amnesia, characterized by an early failure of memory consolidation. It is unknown how propofol affects the amygdala-dependent emotional memory system, which modulates consolidation in the hippocampus in response to emotional arousal and neurohumoral stress. We present an event-related functional magnetic resonance imaging study of the effects of propofol on the emotional memory system in human subjects.

METHODS

Thirty-five healthy subjects were randomized to receive propofol, at an estimated brain concentration of 0.90 μg ml(-1), or placebo. During drug infusion, emotionally arousing and neutral images were presented in a continuous recognition task, while blood-oxygen-level-dependent activation responses were acquired. After a drug-free interval of 2 h, subsequent memory for successfully encoded items was assessed. Imaging analysis was performed using statistical parametric mapping and behavioural analysis using signal detection models.

RESULTS

Propofol had no effect on the stereotypical amygdalar response to emotional arousal, but caused marked suppression of the hippocampal response. Propofol caused memory performance to become uncoupled from amygdalar activation, but it remained correlated with activation in the posterior hippocampus, which decreased in proportion to amnesia.

CONCLUSIONS

Propofol is relatively ineffective at suppressing amygdalar activation at sedative doses, but abolishes emotional modulation and causes amnesia via mechanisms that commonly involve hyporesponsiveness of the hippocampus. These findings raise the possibility that amygdala-dependent fear systems may remain intact even when a patient has diminished memory of events. This may be of clinical importance in the perioperative development of fear-based psychopathologies, such as post-traumatic stress disorder.

CLINICAL TRIAL REGISTRATION

NCT00504894.

Vascular depression: a new view of late-onset depression

We have suggested that cerebrovascular disease may predispose, precipitate, or perpetuate some late-life depressive syndromes. The mechanisms of "vascular depression" include disruption of cortico-striato-pallido-thalamo-cortical (CSPTC) pathways or their modulating systems. This view is supported by the presentation of vascular depression, which consists of depressive symptoms, cognitive abnormalities, as well as neuroimaging findings that may result from CSPTC impairment. Moreover, clinical and electrophysiological evidence of CSPTC impairment, an abnormality frequently found in patients with vascular depression, appears to be associated with poor response to antidepressant treatment and early relapse and recurrence. The vascular depression hypothesis provides the conceptual background for studies that may have clinical and theoretical impact. Agents influencing dopamine, acetylcholine, and opioid neurotransmitters may be studied in vascular depression, since these are essential neurotransmitters of the frontostriatal circuitry. Drugs used for prevention and treatment of cerebrovascular disease may be shown to reduce the risk for vascular depression or improve its outcomes. The choice of antidepressants in vascular depression may depend on their effect on neurological recovery from ischemic lesions. Finally, identification of specific relationships between specific symptoms, cognitive deficits, and disability may lead to interventions that target the patients' deficits as well as their interactions with psychosocial factors known to contribute to depression. Research can clarify the pathways to vascular depression by focusing on the site of lesion, the resultant brain dysfunction, the presentation of depression and time of onset, and the contribution of nonbiological factors.

Chiral resolution of the enantiomers of new selective CB2 receptor agonists by liquid chromatography on amylose stationary phases

Analytical HPLC methods using derivatized amylose chiral stationary phases, Chiralpak AD-H and Chiralpak AS, were developed for the direct enantioseparation of eight substituted 4-oxo-1,4-dihydroquinoline-3-carboxamide derivatives with one stereogenic center. Baseline separation (Rs>1.5) was always achieved on amylose based Chiralpak AD-H column to the difference with Chiralpak AS. Using UV detection, a linear response was observed within a 180-420 micromol L(-1) concentration range (r2>0.991) for three racemic compounds 1, 3 and 4 with best pharmacological potentials; repeatability, limit of detection (LD) and quantification (LQ) were also determined: LD varied, for the solutes, from 0.36 to 2.56 micromol L(-1). Finally, the enantiopurity of these compounds was determined. Additionally, the effect of temperature variations upon isomer separations was investigated.

Four novel mutations, including the first gross deletion in TCF1, identified in HNF-4alpha, GCK and TCF1 in patients with MODY in Israel

Maturity onset diabetes of the young (MODY) is characterized by a primary defect in insulin secretion with non-ketotic hyperglycemia, monogenic autosomal dominant mode of inheritance, age at onset less than 25 years, and lack of autoantibodies. The aim of this study was to characterize the genetic basis of MODY in different ethnic groups in the Israeli population. Fifty-nine unrelated Israeli patients with MODY were assessed for mutations in the three common MODY genes: hepatocyte nuclear factor (HNF)-4alpha, glucokinase (GCK), and transcription factor 1 (TCF1). Overall, 11 mutations in 12 unrelated families were found (20.3% of patients), for a relative frequency of 1.7% for MODY1, 8.5% for MODY2, and 10.1% for MODY3. Four mutations were novel, including the first gross deletion ever described in the TCF1 gene. The low overall mutation frequency found here may suggest the involvement of other, yet unidentified, genes in the etiology of MODY in Israel.

Impact of a two-arm educational program for improving diabetes care in primary care centres

Improvement of the quality of diabetes care is essential for reducing diabetes complications. Nevertheless, compliance with diabetes clinical practice recommendations is inadequate in primary care. The aim of this study was to assess the impact of diabetes education, when directed simultaneously to both diabetes care providers and patients, on the frequency of performance of relevant laboratory tests and improvement of metabolic control. A three-step educational program was applied at 45 community clinics of a health-managed organisation comprising 175 health care providers and 16,275 diabetic patients. At the end of a 2-year period, the proportion of diabetic patients with HbA1c tested at least once a year rose from 60 to 85%. The percentage of patients with HbA1c <7% rose from 38 to 50%, whereas the percentage with HbA1c >8.5% decreased from 27 to 19%. The number of patients visiting an eye clinic at least once yearly rose from 55 to 65% and of those undergoing microalbumin testing from 27 to 37%. There was a 20% increase in the number of patients with low-density lipoprotein cholesterol measurements. Our study demonstrates the efficacy of diabetes education when directed simultaneously to health care providers and diabetic patients. The improvement in quality of care induced by such intervention can translate into better metabolic control and, ultimately, the prevention of diabetes complications.

Functional neuroanatomy of non-verbal semantic sound processing in humans

Environmental sounds convey specific meanings and the neural circuitry for their recognition may have preceded language. To dissociate semantic mnemonic from sensory perceptual processing of non-verbal sound stimuli we systematically altered the inherent semantic properties of non-verbal sounds from natural and man-made sources while keeping their acoustic characteristics closely matched. We hypothesized that acoustic analysis of complex non-verbal sounds would be right lateralized in auditory cortex regardless of meaning content and that left hemisphere regions would be engaged when meaningful concept could be extracted. Using H(2) (15)O-PET imaging and SPM data analysis, we demonstrated that activation of the left superior temporal and left parahippocampal gyrus along with left inferior frontal regions was specifically associated with listening to meaningful sounds. In contrast, for both types of sounds, acoustic analysis was associated with activation of right auditory cortices. We conclude that left hemisphere brain regions are engaged when sounds are meaningful or intelligible.

Processing of environmental sounds in schizophrenic patients: disordered recognition and lack of semantic specificity

The recognition of environmental sounds is an important feature of higher auditory processing and essential for everyday life. The present study aimed to investigate the potential impairment of this mental function in schizophrenia. This work on immediate sound recognition is complementary to recent studies on auditory linguistic processing. Fifteen schizophrenic patients and 30 control subjects were asked to identify 43 complex environmental sounds from different categories and rate their familiarity when naïve to the sounds. In consecutive experiments, patients and control subjects rated the sounds according to emotional valence and arousal, as well as imageability. In both groups, correct identification of non-verbal sounds was highly associated with familiarity. Statistical analysis by group demonstrated a significantly higher error rate in identifying sounds in patients suffering from schizophrenia compared to healthy control subjects. In contrast, the affective recognition of the complex sounds was preserved in the schizophrenic patients. These results suggest a disturbance of higher-order, auditory mnemonic processing in schizophrenic patients in the non-linguistic domain. We discuss their abnormal responses in the context of recent theories of auditory physiological and semantic processing deficits in schizophrenia.

Mapping transient, randomly occurring neuropsychological events using independent component analysis

The feasibility of mapping transient, randomly occurring neuropsychological events using independent component analysis (ICA) was evaluated in an auditory sentence-monitoring fMRI experiment, in which prerecorded short sentences of random content were presented in varying temporal patterns. The efficacy of ICA on fMRI data with such temporal characteristics was assessed by a series of simulation studies, as well as by human activation studies. The effects of contrast-to-noise ratio level, spatially varied hemodynamic response within a brain region, time lags of the responses among brain regions, and different simulated activation locations on the ICA were investigated in the simulations. Component maps obtained from the auditory sentence-monitoring experiments in each subject using ICA showed distinct activation in bilateral auditory and language cortices, as well as in superior sensorimotor cortices, consistent with previous PET studies. The associated time courses in the activated brain regions matched well to the timing of the sentence presentation, as evidenced by the recorded button-press response signals. Methods for ICA component ordering that may rank highly the components of primary interest in such experiments were developed. The simulation results characterized the performance of ICA under various conditions and may provide useful information for experimental design and data interpretation.

Pulmonary function in patients with diabetes mellitus

BACKGROUND

Pulmonary complications of diabetes mellitus have been poorly characterized. Although some authors have reported normal pulmonary function, others found abnormalities in lung volumes, pulmonary mechanics, and diffusing capacity.

SUBJECTS AND METHODS

We studied pulmonary function in a group of patients with diabetes using a combined cardiopulmonary exercise test. Twenty-seven patients with diabetes aged 48 +/- 13 years participated in the study.

RESULTS

Overall, forced vital capacity, forced expiratory volume in 1 second, and forced expiratory flow, midexpiratory phase, were within the predicted values, but the residual volume/total lung capacity ratio was slightly elevated. Comparison by diabetes type showed nonsignificant differences in forced expiratory volume in 1 second and forced expiratory flow, midexpiratory phase. Residual volume/total lung capacity ratio was significantly elevated in type 1 patients compared with type 2. Carbon monoxide diffusion capacity (DLCO) was normal in both groups. There was no correlation between the results on pulmonary function test and duration of disease, presence of microangiopathy, or glycemic control. The DLCO was significantly lower in patients with microangiopathic changes, but not when DLCO was corrected for alveolar volume. On the cardiopulmonary exercise test, maximal workload, maximum oxygen uptake, and maximal heart rate were less than predicted, whereas anaerobic threshold and ventilatory reserve were normal. No significant differences were noted in diabetes type, and there was no correlation between parameters of cardiopulmonary exercise test and the other variables.

CONCLUSION

Spirometric values are preserved in patients with diabetes mellitus, and there are no defects in diffusing capacity. Cardiovascular factors may account for impaired physical performance. There is no need for routine screening of pulmonary function among diabetic patients.

Hippocampal and anterior cingulate activation deficits in patients with geriatric depression

OBJECTIVE

The authors assessed frontotemporal function in patients with geriatric depression, a debilitating and increasingly prevalent disorder that has not been examined with brain activation paradigms.

METHOD

Six depressed elderly patients and five healthy comparison subjects underwent high-sensitivity [(15)O]H(2)O positron emission tomography scans during a paced word generation task and a resting condition.

RESULTS

Bilateral activation deficits were noted in the dorsal anterior cingulate gyrus and hippocampus of the depressed geriatric patients relative to the comparison subjects. Patients had memory deficits that correlated with lower hippocampal activity during both rest and activation.

CONCLUSIONS

These initial findings suggest that hippocampal and dorsal anterior cingulate hypoactivation may constitute contributing neural substrates of geriatric depression. They also suggest that hippocampal dysfunction is related to the memory dysfunction characteristic of this disorder.

Neointimal and tubulointerstitial infiltration by recipient mesenchymal cells in chronic renal-allograft rejection

BACKGROUND

Tissue remodeling depends on mesenchymal cells (fibroblasts and myofibroblasts) and is a prominent feature of chronic renal-transplant rejection. It is not known whether the mesenchymal cells that participate in remodeling originate locally or from circulating precursor cells.

METHODS

We obtained biopsy specimens of renal allografts from six male recipients of an allograft from a female donor, four female recipients of an allograft from a male donor, two male recipients of an allograft from a male donor, and two female recipients of an allograft from a female donor. All the allografts were undergoing chronic rejection. All but two specimens were obtained within six months after transplantation. We used immunohistochemical methods to identify mesenchymal cells with smooth-muscle alpha-actin and in situ hybridization to identify mesenchymal cells with Y-chromosome DNA.

RESULTS

No Y-chromosome bodies were identified in the case of the two renal-allograft specimens in which both the donor and the recipient were female. In the case of the two renal-allograft specimens in which both the donor and the recipient were male, approximately 40 percent of mesenchymal cells contained a Y-chromosome body. In the case of the six specimens in which the donor was female and the recipient was male, a mean (+/-SD) of 34+/-16 percent of mesenchymal cells in the neointima, 38+/-12 percent of such cells in the adventitia, and 30+/-7 percent of such cells in the interstitium contained the Y-chromosomal marker, indicating that they originated from the recipient rather than the donor. In the case of the four renal-allograft specimens in which the donor was male and the recipient was female, the respective values were 24+/-15 percent, 33+/-9 percent, and 23+/-8 percent, indicating a persistent population of donor mesenchymal cells.

CONCLUSIONS

The presence of mesenchymal cells of host origin in the vascular and interstitial compartments of renal allografts undergoing chronic rejection provides evidence that a circulating mesenchymal precursor cell has the potential to migrate to areas of inflammation.

XAFS at the Pacific Northwest Consortium-Collaborative Access Team undulator beamline

The Pacific Northwest Consortium-Collaborative Access Team (PNC-CAT) has begun operating an insertion device beamline at the Advanced Photon Source. The beamline has been extensively used for XAFS studies. This paper summarizes its capabilities, and our initial operational experience. The beamline is based on APS undulator A, and incorporates full undulator scanning. The monochromator is liquid nitrogen cooled and has both Si(111) and Si(311) crystals in a side-by-side configuration. Crystal changes only take a few minutes. The crystals cover the energy range from 3-50 keV with fluxes as high as 2x10(13) ph/sec. Microbeams can be produced using Kirkpatrick-Baez mirrors (spot size 1-3 microm) or tapered capillaries (sub-microm spots). When these optics are combined with a 13-element Ge detector, the beamline provides powerful microbeam imaging and spectroscopy capabilities. Experimental examples from the environmental field and in-situ UHV film growth will be discussed.

Advances in functional neuroimaging methodology for the study of brain systems underlying human neuropsychological function and dysfunction

Functional neuroimaging allows the non-invasive identification of distributed patterns of human brain activity associated with perceptual, congnitive, emotional and behavioral processes, in health and disease. Work in this field is methodologically intensive, requiring an interdisciplinary team of scientists to develop and apply rapidly advancing techniques. Here we focus upon the principles and methods of functional imaging, from hypothesis generation and study design, to subject recruitment and clinical characterization, neuropsychological paradigm development, image acquisition, image processing and statistical analysis, and data interpretation. The strengths and limitations of the various techniques are discussed, with an emphasis on positron emission tomography (PET) and functional magnetic resonance imaging (fMRI), which have proven to be powerful tools for human brain mapping. The integration of these techniques with electroencephalography (EEG) and magnetoencephalography (MEG), which provide greater temporal information, is outlined. An understanding of such methodological issues is a necessary prerequisite to the development of new imaging methods with improved capabilities, to the careful application of existing methods to neuropsychological problems, and to the critical examination of planned or published studies.

Functional neuroimaging of human central auditory processing in normal subjects and patients with neurological and neuropsychiatric disorders

Auditory sensory processing in the human cerebral cortex is disturbed in several neurological and neuropsychiatric disorders, ranging from devastating perceptual deficits in neuropsychological syndromes such as cortical deafness and auditory agnosia to the problem of involuntary hallucinatory perception in schizophrenia. With modern non-invasive functional imaging techniques (e.g., PET, fMRI, and MEG), the normal auditory cortical functional anatomy can now be studied in humans in vivo, as well as its disruption in pathological conditions. This article will summarize current knowledge on human central auditory perception in health and disease, with an emphasis on recent functional neuroimaging studies, in the context of clinical and basic neuroscientific knowledge. New strategies include a focus on the role of other, non-temporal brain areas for auditory processing, particularly in the frontal lobes, and the combined use of techniques offering both precise spatial and temporal resolution. One step towards this goal has been the recent development of a silent, event-related fMRI scanning technique.

Hospitalization for general medical conditions among diabetic patients in Israel

BACKGROUND

Diabetes mellitus is a serious, costly and growing public health problem. Very few studies have been published on the economic impact of diabetes in Israel.

OBJECTIVE

To estimate health fund expenditures and rates of hospitalization for general conditions among the diabetic population in Israel.

METHODS

The total number of hospitalizations in Israel in 1998 of beneficiaries of the General Sick Fund (Kupat Holim Clalit) was obtained from its bureau of statistics. The diabetic and general populations were compared for age and gender distribution, days of hospitalization and cost of hospitalization. All hospitals in Israel were included.

RESULTS

There were 618,317 general admissions for a total of 3,005,288 hospitalization days. The diabetic population accounted for 11.5% of all admissions and 13.7% of all hospitalization days. Analysis by age revealed that diabetic patients over age 45 represented 18.3% of all admissions and 17.5% of all hospitalization days. The average stay in hospital was 4.8 days per patient for the general population and 5.3 days for diabetic patients. The overall hospital expenditure of the GSF for general medical conditions among diabetic patients in 1998 was estimated at US $173,455,790, of which 57% accounted for the daily hospitalization cost. Of the total hospital expenditures for that year, 13.3% was allocated to patients with diabetes of whom 96.4% were over 45 years old. No significant difference was found between males and females.

CONCLUSION

Hospital expenditures for diabetic people increase with patient age and represent one-fifth of the total health insurance expenditure for the middle-aged and elderly population.

Increased anterior cingulate and caudate activity in bipolar mania

BACKGROUND

Executive control of cognition, emotion, and behavior are disrupted in the manic state of bipolar disorder. Whereas frontal systems are implicated in such dysfunction, the localization of functional brain abnormalities in the manic state is not well understood.

METHODS

We utilized a high-sensitivity H(2)(15)0 positron emission tomography technique to investigate regions of increased brain activity in mania, compared to euthymia, in bipolar disorder.

RESULTS

The principal findings were manic state-related increased activity in left dorsal anterior cingulate, and left head of caudate.

CONCLUSIONS

The findings suggest that the manic state of bipolar disorder may be associated with heightened activity in a frontal cortical-subcortical neural system that includes the anterior cingulate and caudate.

Transit time, trailing time, and cerebral blood flow during brain activation: measurement using multislice, pulsed spin-labeling perfusion imaging

Transit time and trailing time in pulsed spin-labeling perfusion imaging are likely to be modulated by local blood flow changes, such as those accompanying brain activation. The majority of transit/trailing time is due to the passage of the tagged blood bolus through the arteriole/capillary regions, because of lower blood flow velocity in these regions. Changes of transit/trailing time during activation could affect the quantification of CBF in functional neuroimaging studies, and are therefore important to characterize. In this work, the measurement of transit and trailing times and CBF during sensorimotor activation using multislice perfusion imaging with pulsed arterial spin-labeling is described. While CBF elevated dramatically ( thick similar80.7%) during the sensorimotor activation, sizable reductions of transit time ( thick similar0.11 sec) and trailing time ( thick similar0.26 sec) were observed. Transit and trailing times were dependent on the distances from the leading and trailing edges of the tagged blood bolus to the location of the imaging slices. The effects of transit/trailing time changes on CBF quantification during brain activation were analyzed by simulation studies. Significant errors can be caused in the estimation of CBF if such changes of transit/trailing time are not taken into account.

A CBF-based event-related brain activation paradigm: characterization of impulse-response function and comparison to BOLD

A perfusion-based event-related functional MRI method for the study of brain activation is presented. In this method, cerebral blood flow (CBF) was measured using a recently developed multislice arterial spin-labeling (ASL) perfusion imaging method with rapid spiral scanning. Temporal resolution of the perfusion measurement was substantially improved by employing intertrial subtraction and stimulus-shifting schemes. Perfusion and blood oxygenation level-dependent (BOLD) signals were obtained simultaneously by subtracting or adding the control and labeled images, respectively, in the same data sets. The impulse response function (IRF) of perfusion during brain activation was characterized for multiple stimulus durations and compared to the simultaneously acquired BOLD response. The CBF response curve preceded the BOLD curve by 0.21 s in the rising phase and 0.64 s in the falling phase. Linear additivity of the CBF and BOLD responses was assessed with rapidly repeated stimulations within single trials, and departure from linearity was found in both responses, characterized as attenuated amplitude and delayed rising time. Event-related visual and sensorimotor activation experiments were successfully performed with the new perfusion technique.