Arch Intern Med 2006 May 22; 166(10): 1115-20 (Read article online)

Wang L, Larson EB, Bowen JD, van Belle G

BACKGROUND: The association of physical function with progression to dementia has not been well investigated. We aimed to determine whether physical function is associated with incident dementia and Alzheimer disease (AD). METHODS: We performed a prospective cohort study of 2288 persons 65 years and older without dementia. Patients were enrolled from 1994 to 1996 and followed up through October 2003. Main outcome measures included incident dementia and AD. RESULTS: During follow-up 319 participants developed dementia (221 had AD). The age-specific incidence rate of dementia was 53.1 per 1000 person-years for participants who scored lower on a performance-based physical function test at baseline (10 points). A 1-point lower performance-based physical function score was associated with an increased risk of dementia (hazard ratio, 1.08; 95% confidence interval, 1.03-1.13; P<.001), an increased risk of AD (hazard ratio, 1.06; 95% confidence interval, 1.01-1.12; P = .01), and an increased rate of decline in the Cognitive Ability Screening Instrument scores (0.11 point per year; 95% confidence interval, 0.08-0.14; P<.001) after adjusting for age, sex, years of education, baseline cognitive function, APOE epsilon4 allele, family history of AD, depression, coronary heart disease, and cerebrovascular disease. CONCLUSIONS: Lower levels of physical performance were associated with an increased risk of dementia and AD. The study suggests that poor physical function may precede the onset of dementia and AD and higher levels of physical function may be associated with a delayed onset.

World J Gastroenterol 2006 May 7; 12(17): 2701-7 (Read article online)

Barry S, Dinan TG

The pathogenesis of Functional Dyspepsia (FD) remains unclear, appears diverse and is thus inadequately understood. Akin to other functional gastrointestinal disorders, research has demonstrated an association between this common diagnosis and psychosocial factors and psychiatric morbidity. Conceptualising the relevance of these factors within the syndrome of FD requires application of the biopsychosocial model of disease. Using this paradigm, dysregulation of the reciprocal communication between the brain and the gut is central to symptom generation, interpretation and exacerbation. Appreciation and understanding of the neurobiological correlates of various psychological states is also relevant. The view that psychosocial factors exert their influence in FD predominantly through motivation of health care seeking also persists. This appears too one-dimensional an assertion in light of the evidence available supporting a more intrinsic aetiological link. Evolving understanding of pathogenic mechanisms and the heterogeneous nature of the syndrome will facilitate effective management. Co-morbid psychiatric illness warrants treatment with conventional therapies. Acknowledging the relevance of psychosocial variables in FD, the degree of which is subject to variation, has implications for assessment and management. Available evidence suggests psychological therapies may benefit FD patients particularly those with chronic symptoms. The rationale for use of psychotropic medications in FD is apparent but the evidence base to support the use of antidepressant pharmacotherapy is to date limited.

Anesth Analg 2006 Jun; 102(6): 1709-14 (Read article online)

Orth M, Bravo E, Barter L, Carstens E, Antognini JF

Isoflurane and halothane cause electroencephalographic (EEG) depression and neuronal depression in the reticular formation, a site critical to consciousness. We hypothesized that isoflurane, more than halothane, would depress EEG activation elicited by electrical microstimulation of the reticular formation. Rats were anesthetized with either halothane or isoflurane and stimulating electrodes were positioned in the reticular formation. In a crossover design, anesthetic concentration was adjusted to 0.8 and 1.2 minimum alveolar concentration (MAC) of halothane or isoflurane and electrical microstimulation was performed and the EEG responses were recorded. Microstimulation increased the spectral edge and median edge frequencies 2-2.5 Hz at 0.8 MAC for halothane and isoflurane and 1.2 MAC halothane. At 1.2 MAC isoflurane, burst suppression occurred and microstimulation decreased the period of isoelectricity (24% +/- 19% to 8% +/- 7%; P < 0.05), whereas the spectral edge and median edge frequencies were unchanged. At anesthetic concentrations required to produce immobility, the cortex remains responsive to electrical microstimulation of the reticular formation, although the EEG response is depressed in the transition from 0.8 to 1.2 MAC. These data indicate that cortical neurons remain responsive to synaptic input during isoflurane and halothane anesthesia.

J Head Trauma Rehabil 2006 May-Jun; 21(3): 236-47 (Read article online)

Testa JA, Malec JF, Moessner AM, Brown AW

OBJECTIVE: To identify risk factors for poor family functioning and neurobehavioral problems after traumatic brain injury (TBI) or orthopedic injuries (OI). DESIGN: Longitudinal analyses of data from an inception cohort. PARTICIPANTS: Seventy-five patients with moderate/severe TBI, 47 patients with mild TBI, and 44 patients with OI at discharge; and 49 patients with moderate/severe TBI, 24 patients with mild TBI, and 33 patients with OI at 1-year follow-up. Outcome measures: Measures of family functioning (Family Assessment Device) and Neurobehavioral Functioning Index at hospital discharge and 1-year follow-up. RESULTS: At discharge, patients with moderate/severe TBI had more symptoms of depression, memory/attention problems, and motor impairments than patients with OI and greater communication difficulties than patients with OI or mild TBI. At follow-up, patients with moderate/severe TBI continued to have more problems in memory/attention, depression, and communication. Approximately one third of each group had unhealthy family functioning at each assessment period. Few patients reported both impaired family functioning and clinical depression. Distressed family functioning correlated strongly with increased rates of neurobehavioral symptoms. Family dysfunction at follow-up was best predicted by family dysfunction at discharge and depression or memory/attention deficits at follow-up. CONCLUSIONS: After TBI, patients at the greatest risk for distress at follow-up were those with family dysfunction at discharge and continued neurobehavioral problems. High-risk families need to be identified so that necessary referrals and/or treatment can be offered.

World J Gastroenterol 2006 May 21; 12(19): 2969-78 (Read article online)

Grover VP, Dresner MA, Forton DM, Counsell S, Larkman DJ, Patel N, Thomas HC, Taylor-Robinson SD

Hepatic encephalopathy (HE) is a common neuro-psychiatric abnormality, which complicates the course of patients with liver disease and results from hepatocellular failure and/or portosystemic shunting. The manifestations of HE are widely variable and involve a spectrum from mild subclinical disturbance to deep coma. Research interest has focused on the role of circulating gut-derived toxins, particularly ammonia, the development of brain swelling and changes in cerebral neurotransmitter systems that lead to global CNS depression and disordered function. Until recently the direct investigation of cerebral function has been difficult in man. However, new magnetic resonance imaging (MRI) techniques provide a non-invasive means of assessment of changes in brain volume (coregistered MRI) and impaired brain function (fMRI), while proton magnetic resonance spectroscopy ((1)H MRS) detects changes in brain biochemistry, including direct measurement of cerebral osmolytes, such as myoinositol, glutamate and glutamine which govern processes intrinsic to cellular homeostasis, including the accumulation of intracellular water. The concentrations of these intracellular osmolytes alter with hyperammonaemia. MRS-detected metabolite abnormalities correlate with the severity of neuropsychiatric impairment and since MR spectra return towards normal after treatment, the technique may be of use in objective patient monitoring and in assessing the effectiveness of various treatment regimens.

J Head Trauma Rehabil 2006 May-Jun; 21(3): 199-212 (Read article online)

Ouellet MC, Beaulieu-Bonneau S, Morin CM

OBJECTIVES: To document the frequency of insomnia (according to DSM-IV and ICSD criteria), to describe its sociodemographic and clinical characteristics, and to identify potential predictors of insomnia in persons with traumatic brain injury (TBI). PARTICIPANTS AND PROCEDURE: Four hundred fifty-two participants aged 16 years and older with minor to severe TBI answered a questionnaire pertaining to quality of sleep and fatigue. MAIN OUTCOME MEASURES: Proportion of participants fulfilling criteria for insomnia symptoms or syndrome. Validated measures of insomnia severity, fatigue level, and psychologic distress. Results of a logistic regression analysis. RESULTS: Overall, 50.2% of the sample reported insomnia symptoms and 29.4% fulfilled the diagnostic criteria for an insomnia syndrome. For the latter participants, insomnia was a severe and chronic condition remaining untreated in almost 60% of cases. Risk factors associated with insomnia were milder TBIs, and higher levels of fatigue, depression, and pain. CONCLUSION: Insomnia is a prevalent condition after TBI requiring more clinical and scientific attention as it may have important repercussions on rehabilitation.

Psychopathology 2006 May 23; 39(4): 187-191 (Read article online)

Favaro A, Tenconi E, Colombo G, Santonastaso P

Background: The aim of the study is to evaluate the frequency and characteristics of full and partial post-traumatic stress disorder (PTSD) among 66 World War II Nazi prisoners of war, some of whom had been deported to death camps. Methods: The Structured Clinical Interview for DSM-IV was used to assess the presence of PTSD and major depression. The Dissociative Experiences Scale and the 58-item version of the Hopkins Symptom Checklist were also administered. Partial PTSD was defined as the presence of at least one symptom in each of the clusters defined by DSM-IV. Results: Forty-eight percent of the subjects have a partial PTSD, while 20% reported the full syndrome. When compared to subjects with full PTSD, those with partial PTSD showed a significantly lower frequency of comorbid depression and lower levels of psychological distress, as measured by the Symptom Checklist. No differences were found with regards to dissociative symptoms and help-seeking. Conclusions: The problem of definition of PTSD partial syndromes deserves more attention in the literature. Copyright (c) 2006 S. Karger AG, Basel.

Anesth Analg 2006 Jun; 102(6): 1789-97 (Read article online)

van Dorp EL, Romberg R, Sarton E, Bovill JG, Dahan A

In searching for an analgesic with fewer side effects than morphine, examination of morphine's active metabolite, morphine-6-glucuronide (M6G), suggests that M6G is possibly such a drug. In contrast to morphine, M6G is not metabolized but excreted via the kidneys and exhibits enterohepatic cycling, as it is a substrate for multidrug resistance transporter proteins in the liver and intestines. M6G exhibits a delay in its analgesic effect (blood-effect site equilibration half-life 4-8 h), which is partly related to slow passage through the blood-brain barrier and distribution within the brain compartment. In humans, M6G's potency is just half of that of morphine. In clinical studies, M6G is well tolerated and produces adequate and long lasting postoperative analgesia. At analgesic doses, M6G causes similar reduction of the ventilatory response to CO(2) as an equianalgesic dose of morphine but significantly less depression of the hypoxic ventilatory response. Preliminary data indicate that M6G is associated less than morphine with nausea and vomiting, causing 50% and 75% less nausea in postoperative and experimental settings, respectively. Although the data from the literature are very promising, we believe that more studies are necessary before we may conclude that M6G is superior to morphine for postoperative analgesia.

Ann Neurol 2006 May 22; 59(6): 939-951 (Read article online)

Lin HJ, Huang CC, Hsu KS

OBJECTIVE: Synthetic glucocorticoid dexamethasone (DEX) is frequently used as a therapeutic agent to lessen the morbidity of chronic lung disease in premature infants. Surprisingly, little is known about the long-term neurodevelopmental outcomes of this therapy. METHODS: Using a schedule of tapering doses of DEX similar to that used in premature infants, we examined the consequences of neonatal DEX treatment on hippocampal synaptic plasticity of infants and associative memory later in their lives. RESULTS: Neonatal DEX treatment changed the direction of synaptic plasticity, favoring low-frequency, stimulation-induced, long-term depression and opposing the induction of long-term potentiation by high-frequency stimulation in adolescent (5-week-old) rats, but these alterations disappeared in young adult (8-week-old) rats. The effects of DEX on long-term depression and long-term potentiation were found to correlate with an increase in the autophosphorylation of Ca(2+)/calmodulin-dependent protein kinase II and a decrease in the protein phosphatase 1 activity. Neonatal DEX treatment also disrupted memory retention in 5-week-old (but not 8-week-old) rats subjected to passive avoidance learning tasks. INTERPRETATION:: These results suggest that neonatal DEX treatment alters hippocampal synaptic plasticity and contextual fear memory formation in later life, but these impairments apparently are not permanent. Ann Neurol 2006;59:939-951.

Mol Psychiatry 2006 May 23; (Read article online)

Hettema JM, An SS, Neale MC, Bukszar J, van den Oord EJ, Kendler KS, Chen X

Abnormalities in the gamma-aminobutyric acid (GABA) neurotransmitter system have been noted in subjects with mood and anxiety disorders. Glutamic acid decarboxylase (GAD) enzymes synthesize GABA from glutamate, and, thus, are reasonable candidate susceptibility genes for these conditions. In this study, we examined the GAD1 and GAD2 genes for their association with genetic risk across a range of internalizing disorders. We used multivariate structural equation modeling to identify common genetic risk factors for major depression, generalized anxiety disorder, panic disorder, agoraphobia, social phobia and neuroticism (N) in a sample of 9270 adult subjects from the population-based Virginia Adult Twin Study of Psychiatric and Substance Use Disorders. One member from each twin pair for whom DNA was available was selected as a case or control based on scoring at the extremes of the genetic factor extracted from the analysis. The resulting sample of 589 cases and 539 controls was entered into a two-stage association study in which candidate loci were screened in stage 1, the positive results of which were tested for replication in stage 2. Several of the six single-nucleotide polymorphisms tested in the GAD1 region demonstrated significant association in both stages, and a combined analysis in all 1128 subjects indicated that they formed a common high-risk haplotype that was significantly over-represented in cases (P=0.003) with effect size OR=1.23. Out of 14 GAD2 markers screened in stage 1, only one met the threshold criteria for follow-up in stage 2. This marker, plus three others that formed significant haplotype combinations in stage 1, did not replicate their association with the phenotype in stage 2. Subject to confirmation in an independent sample, our study suggests that variations in the GAD1 gene may contribute to individual differences in N and impact susceptibility across a range of anxiety disorders and major depression.Molecular Psychiatry advance online publication, 23 May 2006; doi:10.1038/sj.mp.4001845.

Neurology 2006 May 23; 66(10): 1556-8 (Read article online)

Pillon B, Ardouin C, Dujardin K, Vittini P, Pelissolo A, Cottencin O, Vercueil L, Houeto JL, Krystkowiak P, Agid Y, Destée A, Pollak P, Vidailhet M,

OBJECTIVE: To assess the effects of bilateral pallidal deep brain stimulation (DBS) on mood and cognitive performance in patients with dystonia before surgery (at baseline, while patients received their usual treatment) and 12 months postoperatively (while patients received neurostimulation and their medications) in a multicenter prospective study. METHODS: Twenty-two patients with primary generalized dystonia were evaluated with tests focused on executive functions. The authors considered the patients' severe disability and selected the following tests: Raven Progressive Matrices 38, Similarities and Arithmetic subtests of the Wechsler Adult Intelligence Scale-R, Grober and Buschke, Wisconsin Card Sorting Test (WCST), verbal fluency, Trail Making Test, and the Beck Depression Inventory. Median age at surgery was 30 years (range = 14 to 54 years), median duration of disease was 18.5 years (range = 4 to 37 years). RESULTS: Before surgery, no patients showed cognitive decline or depression. The surgical procedure appeared to be benign cognitively. One year after surgery, free recall improved. There was a significant reduction in the number of errors in the WCST. No behavioral or mood changes were found. CONCLUSIONS: Bilateral pallidal stimulation has a good benefit-to-risk ratio as it did not negatively affect cognitive performance and mood in primary dystonia, while a significant motor improvement was obtained. Moreover, a significant mild improvement in executive functions was observed, which may have been related either to the surgical treatment or to the marked decrease in anticholinergic drugs.

Arch Womens Ment Health 2006 May 22; (Read article online)

Howard M, Battle CL, Pearlstein T, Rosene-Montella K

Major depression and other psychiatric disorders are common during pregnancy and the postpartum period, yet these disorders remain largely under-diagnosed and under-treated. Developing programs that are uniquely tailored to meet the needs of perinatal psychiatric patients can improve both the quality and acceptability of care. In this report, we describe the development and implementation of a novel mother-baby day hospital service designed to meet the mental health needs of this special population, and present preliminary data regarding treatment acceptability and effectiveness. Our experience using this model of care for the past five years has suggested that specialized units such as this one represent an acceptable, effective, fiscally viable approach to the care of pregnant and postpartum psychiatric patients. Further research is needed to more thoroughly assess the effectiveness of this type of specialized perinatal service.

J Abnorm Child Psychol 2006 May 23; (Read article online)

Rowe R, Maughan B, Eley TC

Comorbidity between antisocial behavior and depression in adolescence is widely recognized. This paper examines whether links with depressed mood differ among three subtypes of antisocial behavior: oppositionality, physical aggression and delinquency. In addition we examine two possible contributors to these links: negative life events that are dependent upon the individual's actions and depressogenic attributional style. Data are drawn from the G1219 large-scale community twin and sibling sample, and include 2409 questionnaire responses from youths aged between 13 and 19 living in the United Kingdom. Depressed mood was independently associated with both oppositionality and delinquency, but not with physical aggression. Dependent negative life events were strongly implicated in the association between delinquency and depressed mood, whereas depressogenic attributional style was implicated in the associations of both oppositionality and delinquency with depressed mood. Oppositionality remained a significant predictor of depressed mood after accounting for attributional style and life events whereas delinquency did not. The pattern of associations was largely similar in boys and girls. We discuss these results in terms of developmental models of the links between antisocial behavior and depressed mood.

Mol Cell Biochem 2006 May 23; (Read article online)

Raeder MB, Fernø J, Vik-Mo AO, Steen VM

Drug-induced weight gain is a major problem in the treatment of psychiatric disorders, especially with some antipsychotic- and antidepressant drugs. We have recently demonstrated that antipsychotic- and antidepressant drugs activate the SREBP (sterol regulatory element-binding proteins) transcription factors in human- and rat glial cells, with subsequent up-regulation of downstream genes involved in cholesterol- and fatty acid biosynthesis. Since stimulation of cellular lipogenesis in the liver could be of relevance for the metabolic side effects of these drugs, we have now investigated the effects of antidepressants, antipsychotic- and mood-stabilizing drugs on cell cultures of human liver cells. For several of the drugs being strongly associated with weight gain (clozapine, imipramine, and amitriptyline), we observed a very pronounced activation of SREBP. Ziprasidone and buproprion, however, which are not associated with weight gain, did hardly stimulate the SREBP system. For haloperidol, olanzapine and mirtazapine, the correspondence between metabolic side effects and SREBP stimulation in liver cells was less obvious. The mood-stabilizers did not increase SREBP activation. The results indicate a relationship between drug-induced activation of SREBP in cultured human liver cells and weight gain side-effects of antidepressant and antipsychotic drugs.

Dysphagia 2006 May 23; (Read article online)

Ludlow CL, Humbert I, Saxon K, Poletto C, Sonies B, Crujido L

We tested two hypotheses using surface electrical stimulation in chronic pharyngeal dysphagia: that stimulation (1) lowered the hyoid bone and/or larynx when applied at rest, and (2) increased aspiration, penetration, or pharyngeal pooling during swallowing. Bipolar surface electrodes were placed on the skin overlying the submandibular and laryngeal regions. Maximum tolerated levels of stimulation were applied while patients held their mouth closed at rest. Videofluoroscopic recordings were used to measure hyoid movements in the superior-inferior and anterior-posterior dimensions and the subglottic air column position while stimulation was on or off. Patients swallowed 5 ml liquid when stimulation was off, at low sensory stimulation levels, and at maximum tolerated levels (motor). Speech pathologists, blinded to condition, tallied the frequency of aspiration, penetration, pooling, and esophageal entry from videofluorographic recordings of swallows. Only significant (p = 0.0175) hyoid depression occurred during stimulation at rest. Aspiration and pooling were significantly reduced only with low sensory threshold levels of stimulation (p = 0.025) and not during maximum levels of surface electrical stimulation. Those patients who had reduced aspiration and penetration during swallowing with stimulation had greater hyoid depression during stimulation at rest (p = 0.006). Stimulation may have acted to resist patients' hyoid elevation during swallowing.

Eur J Appl Physiol 2006 May 23; (Read article online)

Baudry S, Klass M, Pasquet B, Duchateau J

This study compares the fatigability of the ankle dorsiflexors during five sets of 30 maximal concentric and eccentric contractions in young and elderly adults. The torque produced by the ankle dorsiflexors and the average surface electromyogram (aEMG) of the tibialis anterior were continuously recorded. The contribution of central and peripheral mechanisms to muscle fatigue was tested before, after each set of contractions, and during a 30 min recovery period by the superimposed electrical stimulation method. The compound muscle action potential (M-wave), the mechanical response to single (twitch) and paired (doublet) stimulation, and the postactivation potentiation were also recorded. Compared with young subjects, elderly adults exhibited a greater loss of torque for concentric (50.2 vs. 40.9%; P<0.05) and eccentric (42.1 vs. 27.1%; P < 0.01) contractions. Although young subjects showed a lesser decrease in torque during the eccentric compared with concentric contractions, elderly adults experienced similar fatigability for the two types of contractions despite a comparable depression in the EMG activity of both groups and contraction types (10-20%). As tested by the interpolated-twitch method and aEMG/M-wave ratio, voluntary activation was not altered during either type of contraction or for either age group. During the two fatigue tasks, only elderly adults experienced a decrease in M-wave area (26.4-35.4%; P < 0.05). All together, our results suggest that the fatigue exhibited by both young and elderly adults during maximal concentric and eccentric contractions mainly involved peripheral alterations and that elderly adults may also have experienced a decline in neuromuscular propagation.

J Head Trauma Rehabil 2006 May-Jun; 21(3): 248-59 (Read article online)

Anson K, Ponsford J

OBJECTIVES: To examine the association between coping style and emotional adjustment following traumatic brain injury. PARTICIPANTS: Thirty three individuals who had sustained a traumatic brain injury (mean duration of posttraumatic amnesia = 32 days) between 1(1/2) months and almost 7 years previously. Measures: Coping Scale for Adults, Hospital Anxiety and Depression Scale, Rosenberg Self-Esteem Scale, State-Trait Anger Expression Inventory, and the Sickness Impact Profile. RESULTS: Approximately 50% of the sample reported clinically significant levels of anxiety and depression. Coping characterized by avoidance, worry, wishful thinking, self-blame, and using drugs and alcohol was associated with higher levels of anxiety, depression, and psychosocial dysfunction and lower levels of self-esteem. Coping characterized by actively working on the problem and using humor and enjoyable activities to manage stress was associated with higher self-esteem. Lower premorbid intelligence (measured via the National Adult Reading Test) and greater self-awareness (measured via the Self-Awareness of Deficits Interview) were associated with an increased rate of maladaptive coping. CONCLUSIONS: The strong association between the style of coping used to manage stress and emotional adjustment suggests the possibility that emotional adjustment might be improved by the facilitation of more adaptive coping styles. It is also possible that improving emotional adjustment may increase adaptive coping. The development and evaluation of interventions aimed at facilitating adaptive coping and decreasing emotional distress represent important and potentially fruitful contributions to enhancing long-term outcome following brain injury.

Clin Child Fam Psychol Rev 2006 May 23; (Read article online)

Alloy LB, Abramson LY, Smith JM, Gibb BE, Neeren AM

In this article, we review empirical research on the role of individuals' parenting and maltreatment histories as developmental antecedents for symptoms and diagnosable episodes of unipolar and bipolar spectrum disorders. Our review is focused on the following three overarching questions: (1) Do negative parenting and a history of maltreatment contribute risk to symptoms or diagnosable episodes of unipolar and bipolar disorders? (2) Are the associations of negative parenting and maltreatment histories with bipolar disorders similar to those for unipolar depression? and (3) Are the associations between negative parenting and maltreatment histories and unipolar and bipolar symptoms or disorders mediated by cognitive vulnerability to depression? We begin by discussing the methodological requirements for demonstrating a psychosocial risk factor and the methodological issues that plague the parenting and maltreatment literatures. Next, we review the extant studies on the role of parenting histories in unipolar and bipolar disorders. We consider the specificity and possible moderators of the parenting-mood disorder relationship, as well as cognitive vulnerability to depression as a mediator of this relationship. Then, we review studies on the association of maltreatment histories with unipolar and bipolar disorders and the role of cognitive vulnerability to depression as a mediator of this association. We conclude with an assessment of the state of the parenting and maltreatment literatures in unipolar and bipolar disorder with regard to our guiding questions.

Vestn Otorinolaringol 2006; 31-33 (Read article online)

Zyrianova KS, Kurenkov EL, Kofanov RV, Loginovskikh MA

A low-frequency ultrasound device UZOL-01-Ch was applied for therapy of chronic tonsillitis (CT). The activity of chronic inflammation was followed up under action of 0.05% dioxidine solution coming through the device UZOL-01-Ch on the tissues of palatine tonsils in CT at a clinical remission phase in 34 CT patients. CT activity degrees were proposed which were defined by the presence and distribution of polymorphonuclear neutrophils in inflammatory cellular infiltrate of palatine tonsil mucosa in CT. These degrees help assessed the results of therapeutic effect of the device UZOL-01-Ch on tonsil tissue in CT. Use of the device provided depression of inflammation activity in tonsil mucosa in CT patients at a clinical remission phase.

J Comp Physiol [B] 2006 May 18; (Read article online)

Melzner F, Bock C, Pörtner HO

Earlier work found cuttlefish (Sepia officinalis) ventilatory muscle tissue to progressively switch to an anaerobic mode of energy production at critical temperatures (T (c)) of 7.0 and 26.8 degrees C. These findings suggested that oxygen availability limits thermal tolerance. The present study was designed to elucidate whether it is the ventilatory apparatus that sets critical temperature thresholds during acute thermal stress. Routine metabolic rate (rmr) rose exponentially between 11 and 23 degrees C, while below (8 degrees C) and above (26 degrees C) this temperature range, rmr was significantly depressed. Ventilation frequency (f (V)) and mean mantle cavity pressure (MMP) followed an exponential relationship within the entire investigated temperature range (8-26 degrees C). Oxygen extraction from the ventilatory current (EO(2)) decreased in a sigmoidal fashion with temperature, falling from > 90% at 8 degrees C to 32% at 26 degrees C. Consequently, ventilatory minute volume (MV(V)) increased by a factor of 20 from 7 to 150% body weight min(-1) in the same temperature interval. Increases in MMP and MV(V) resulted in ventilatory muscle power output (P (out)) increasing by a factor of > 80 from 0.03 to 2.4 mW kg(-1) animal. Nonetheless, costs for ventilatory mechanics remain below 1.5% rmr in the natural thermal window of the population (English Channel, 9-17 degrees C), owing to very low MMPs of < 0.05 kPa driving the ventilatory stream, and may maximally rise to 8.6% rmr at 26 degrees C. Model calculations suggest that the ventilatory system can maintain high arterial PO(2) values of > 14 kPa over the entire temperature interval. We therefore conclude that the cuttlefish ventilation system is probably not limiting oxygen transfer during acute thermal stress. Depression of rmr, well before critical temperatures are being reached, is likely caused by circulatory capacity limitations and not by fatigue of ventilatory muscle fibres.