Employment of time-varying sensory evidence to test the mechanisms underlying flexible decision-making

To make flexible decisions in dynamic environments, the brain must integrate behaviorally relevant information while simultaneously discarding irrelevant information. This study aimed to investigate the mechanisms responsible for discarding irrelevant information during context-dependent decision-making. We trained two macaque monkeys to switch between direction and depth discrimination tasks in successive trials. During decision-making, the strength of the motion or depth signal changes transiently at various times, introducing a brief pulse. We assessed the effects of pulse on behavioral choices. Consistent with previous findings, early relevant pulses, such as motion pulses during direction discrimination, had a significantly larger effect compared to late pulses. Critically, the effects of irrelevant pulses, such as motion pulses during depth discrimination, exhibited an initial minimal effect, followed by an increase and subsequent decrease as a function of pulse timing. Gating mechanisms alone, aimed at discarding irrelevant information, did not account for the observed time course of pulse effects. Instead, the observed increase in the effects of irrelevant pulses with time suggested the involvement of a leaky integration mechanism. The results suggested that the brain controls the amount of disposal in accumulating sensory evidence during flexible decision-making.

Representation of Motion Direction in Visual Area MT Accounts for High Sensitivity to Centripetal Motion, Aligning with Efficient Coding of Retinal Motion Statistics

The overrepresentation of centrifugal motion in the middle temporal visual area (area MT) has long been thought to provide an efficient coding strategy for optic flow processing. However, this overrepresentation compromises the detection of approaching objects, which is essential for survival. In the present study, we revisited this long-held notion by reanalyzing motion selectivity in area MT of three macaque monkeys (two males, one female) using random-dot stimuli instead of spot stimuli. We found no differences in the number of neurons tuned to centrifugal versus centripetal motion; however, centrifugally tuned neurons showed stronger tuning than centripetally tuned neurons. This was attributed to the heightened suppression of responses in centrifugal neurons to centripetal motion compared with that of centripetal neurons to centrifugal motion. Our modeling implies that this intensified suppression accounts for superior detection performance for weak centripetal motion stimuli. Moreover, through Fisher information analysis, we establish that the population sensitivity to motion direction in peripheral vision corresponds well with retinal motion statistics during forward locomotion. While these results challenge established concepts, considering the interplay of logarithmic Gaussian receptive fields and spot stimuli can shed light on the previously documented overrepresentation of centrifugal motion. Significantly, our findings reconcile a previously found discrepancy between MT activity and human behavior, highlighting the proficiency of peripheral MT neurons in encoding motion direction efficiently.SIGNIFICANCE STATEMENT The efficient coding hypothesis states that sensory neurons are tuned to specific, frequently experienced stimuli. Whereas previous work has found that neurons in the middle temporal (MT) area favor centrifugal motion, which results from forward locomotion, we show here that there is no such bias. Moreover, we found that the response of centrifugal neurons for centripetal motion was more suppressed than that of centripetal neurons for centrifugal motion. Combined with modeling, this provides a solution to a previously known discrepancy between reported centrifugal bias in MT and better detection of centripetal motion by human observers. Additionally, we show that population sensitivity in peripheral MT neurons conforms to an efficient code of retinal motion statistics during forward locomotion.

Task-Specific Employment of Sensory Signals Underlies Rapid Task Switching

Much of our flexible behavior is dependent on responding efficiently to relevant information while discarding irrelevant information. Little is known, however, about how neural pathways governing sensory-motor associations can rapidly switch to accomplish such flexibility. Here, we addressed this question by electrically microstimulating middle temporal (MT) neurons selective for both motion direction and binocular disparity in monkeys switching between direction and depth discrimination tasks. Surprisingly, we frequently found that the observed psychophysical bias precipitated by delivering microstimulation to neurons whose preferred direction and depth were related to opposite choices in the two tasks was substantially shifted toward a specific movement. Furthermore, these effects correlated with behavioral switching performance. Our findings suggest that the outputs of sensory signals are task specific and that irrelevant sensory-motor pathways are gated depending on task demand so as to accomplish rapid attentional switching.

Prediction-Related Frontal-Temporal Network for Omission Mismatch Activity in the Macaque Monkey

Sensory prediction is considered an important element of mismatch negativity (MMN) whose reduction is well known in patients with schizophrenia. Omission MMN is a variant of the MMN which is elicited by the absence of a tone previously sequentially presented. Omission MMN can eliminate the effects of sound differences in typical oddball paradigms and affords the opportunity to identify prediction-related signals in the brain. Auditory predictions are thought to reflect bottom-up and top-down processing within hierarchically organized auditory areas. However, the communications between the various subregions of the auditory cortex and the prefrontal cortex that generate and communicate sensory prediction-related signals remain poorly understood. To explore how the frontal and temporal cortices communicate for the generation and propagation of such signals, we investigated the response in the omission paradigm using electrocorticogram (ECoG) electrodes implanted in the temporal, lateral prefrontal, and orbitofrontal cortices of macaque monkeys. We recorded ECoG data from three monkeys during the omission paradigm and examined the functional connectivity between the temporal and frontal cortices by calculating phase-locking values (PLVs). This revealed that theta- (4-8 Hz), alpha- (8-12 Hz), and low-beta- (12-25 Hz) band synchronization increased at tone onset between the higher auditory cortex and the frontal pole where an early omission response was observed in the event-related potential (ERP). These synchronizations were absent when the tone was omitted. Conversely, low-beta-band (12-25 Hz) oscillation then became stronger for tone omission than for tone presentation approximately 200 ms after tone onset. The results suggest that auditory input is propagated to the frontal pole via the higher auditory cortex and that a reciprocal network may be involved in the generation of auditory prediction and prediction error. As impairments of prediction may underlie MMN reduction in patients with schizophrenia, an aberrant hierarchical temporal-frontal network might be related to this pathological condition.

Effects of the time-of-day (morning vs. afternoon) of implementing a combined physical and cognitive exercise program on cognitive functions and mood of older adults: A randomized controlled study

This study examined the effects of the time of conducting a combined physical and cognitive exercise program on cognitive functions and the mood of older adults. We randomly assigned 17 participants (8 men, 9 women, age 73,24±3,75) to the morning group (AM Group), 18 (8 men, 10 women, age 73,11±4,84) to the afternoon group (PM Group), and they completed a 12-week, dual-task exercise program in the morning or the afternoon, respectively. Moreover, the waiting-list control group consisted of 12 participants (6 men, 6 women, age 73,25±5,93). The cognitive functions and the mood of the participants were assessed before and after the program by using the Neurobehavioral Cognitive Status Examination, and the short version of the Profile of Mood States, respectively. As a result, the exercise program conducted in the afternoon had broader effects on cognitive functions (increased Repetition and Memory) than in the morning (increased Repetition), or the waiting-list control group (increased Judgment). Moreover, the program in the afternoon tended to reduce Anger-Hostility, and Fatigue. In conclusion, conducting the exercise program in the afternoon might be more effective for improving cognitive functions and the mood of older adults than in the morning. However, there was heterogeneity between the groups despite the randomization. Therefore, we suggest conducting a more rigorously controlled study using a larger sample to validate these findings.

“Mobile Nurse” Platform for Ubiquitous Medicine

Objectives : We introduce “Mobile Nurse" (MN) - an emerging platform for the practice of ubiquitous medicine.

Methods : By implementing in a dynamic setting of daily life the patient care traditionally provided by the clinical nurses on duty, MN aims at integral data collection and shortening the response time to the patient. MN is also capable of intelligent interaction with the patient and is able to learn from the patient's behavior and disease sign evaluation for improved personalized treatment.

Results : In this paper, we outline the most essential concepts around the hardware, software and methodological designs of MN. We provide an example of the implementation, and elaborate on the possible future impact on medical practice and biomedical science research.

Conclusions : The main innovation of MN, setting it apart from current tele-medicine systems, is the ability to integrate the patient's signs and symptoms on site, providing medical professionals with powerfultools to elucidate disease mechanisms, to make proper diagnoses and to prescribe treatment.

Visual impairment by surrounding noise is due to interactions among stimuli in the higher-order visual cortex

Observers have difficulty identifying a target in their peripheral vision in the presence of surrounding stimuli. Although hypotheses addressing this phenomenon have been proposed, such as the integration of stimuli and surround suppression in the higher-order visual cortex, no direct comparisons of the psychophysical and neuronal sensitivities have been performed. Here we measured the performance of monkeys with a variant of the direction discrimination task using a center/surround bipartite random-dot stimulus while simultaneously recording from isolated neurons from the middle temporal visual area (MT). The psychophysical threshold increased with the addition of a task-irrelevant noise annulus that surrounded the task-relevant motion stimuli. The neuronal threshold of MT neurons also increased at a spatial scale similar to the psychophysical threshold. This suggests that the impaired ability in our task resulted from impairment in the MT area. Importantly, reduced neuronal performance was due to both a reduced response to preferred motion and an enhanced response to nonpreferred motion. These observations suggest that impairment caused by surrounding noise results from interactions between stimuli and noise and not from a reduction in the response of visual neurons.

Neuronal mechanisms of visual perceptual learning

Numerous psychophysical studies have described perceptual learning as long-lasting improvements in perceptual discrimination and detection capabilities following practice. Where and how long-term plastic changes occur in the brain is central to understanding the neural basis of perceptual learning. Here, neurophysiological research using non-human primates is reviewed to address the neural mechanisms underlying visual perceptual learning. Previous studies have shown that training either has no effect on or only weakly alters the sensitivity of neurons in early visual areas, but more recent evidence indicates that training can cause long-term changes in how sensory signals are read out in the later stages of decision making. These results are discussed in the context of learning specificity, which has been crucial in interpreting the mechanisms underlying perceptual learning. The possible mechanisms that support learning-related plasticity are also discussed.

Reversed intestinal malrotation with concurrent cecal carcinoma

A 57-year-old man was admitted with a type 2 (ulcerated with clear margin) cancer in the cecum. Contrast-enhanced CT showed that the superior mesenteric vein was anterior to the superior mesenteric artery, and the patient was suspected of having intestinal malrotation. A laparoscopic-assisted ileocecal resection was performed. At operation, the cecum and the transverse colon passed through the root of the mesentery behind the superior mesenteric artery with the duodenum. Therefore, this was thought to be a reversed-type intestinal malrotation. After the operation, 3D-CT colonography with duodenography images were reconstructed to retrospectively confirm the diagnosis of a reversed malrotation. These images clearly demonstrated the abnormal anatomy and overall orientation of the intestine. Patients with a reversed intestinal malrotation and concurrent cecal cancer are extremely rare. Herein, we present a patient who underwent a laparoscopic-assisted ileocecal resection for cecal cancer that presented concurrently with a reversed intestinal malrotation.

Reduction in receptive field size of macaque MT neurons in the presence of visual noise

The visual system faces a trade-off between increased spatial integration of disparate local signals and improved spatial resolution to filter out irrelevant noise. Increased spatial integration is beneficial when signals are weak, whereas increased spatial resolution is particularly beneficial when focusing on a small object in a cluttered natural scene. The receptive field (RF) size of visual cortical neurons can be modulated depending on various factors such as sensory context, allowing adaptive integration of sensory signals. In this study, we explored the spatial integration properties of neurons in macaque middle temporal visual area (MT). We hypothesized that spatial resolution would increase when high-contrast noise was presented simultaneously with a visual stimulus, enabling focus on a small object in a cluttered scene. To test this hypothesis, we mapped the RFs of MT neurons of two fixating monkeys in a 5 × 5 grid manner using a small patch of random-dot motion. To examine the effects of noise on RF profile, a dynamic noise (0% coherence dots) of varying diameter was concurrently presented at the RF center. We found that RF size decreased when noise diameter increased. Analyses based on the response normalization model and area summation provided evidence for the potential contribution of spatial summation properties within the RF and surround suppression to the apparent contraction of RF size. Our results suggest that MT neurons integrate smaller regions of motion signals when signals are embedded in noise, an efficient strategy to filter out surrounding noise.

Enhanced photon generation in a Nb/n-InGaAs/p-InP superconductor/semiconductor-diode light emitting device

We experimentally demonstrate Cooper pairs' drastic enhancement of the band-to-band radiative recombination rate in a semiconductor. Electron Cooper pairs injected from a superconducting electrode into an active layer by the proximity effect recombine with holes injected from a p-type electrode. The recombination of a Cooper pair with p-type carriers dramatically increases the photon generation probability of a light-emitting diode in the optical-fiber communication band. The measured radiative decay time rapidly decreases with decreasing temperature below the superconducting transition temperature of the niobium electrodes. Our results indicate the possibility to open up new interdisciplinary fields between superconductivity and optoelectronics.

Characterization of two-photon polarization mixed states generated from entangled-classical hybrid photon source

We experimentally prepare bi-photon mixed states in polarization employing an entangled-classical hybrid photon emitter which can properly model solid-state entangled photon sources with uncorrelated background photons. Polarization-uncorrelated photon pairs in totally mixed (TM) states are embodied with classical thermal radiation, while the polarization-entangled ones in a Bell state are generated by conventional parametric down conversion. The bi-photon states generated from the hybrid photon emitter are characterized in terms of a linear entropy-tangle plane, which reveals the formation of two-qubit Werner states. We also propose a direct way for evaluating the Werner states by means of minimal coincidence counts measurements. This simple method can be widely applicable in examining the bi-photon states from solid-state entangled photon sources, in which the polarization-entangled photon pairs have temporal correlation while the background photons in the TM states do not.

The spatial profile of macaque MT neurons is consistent with Gaussian sampling of logarithmically coordinated visual representation

Neurons in extrastriate visual areas have large receptive fields (RFs) compared with those in primary visual cortex (V1), suggesting extensive spatial integration. To examine the spatial integration of neurons in area MT, we modeled the RFs of MT neurons based on a symmetrical (Gaussian) integration of V1 outputs and tested the model using single-unit recording in two fixating macaque monkeys. Because visual representation in V1 is logarithmically compressed along eccentricity, the resulting RF model is log-Gaussian along the radial axis in polar coordinates. To test the log-Gaussian model, the RF of each neuron was mapped on a 5 x 5 grid using a small patch of random dots drifting at the preferred velocity of the neuron. The majority of MT neurons had RFs with a steeper slope near the fovea and a shallower slope away from the fovea. Among various two-dimensional Gaussian models fitted to the RFs, the log-Gaussian model provided the best description. The fitted parameters revealed that the range of sampling by MT neurons has no systematic relationship with eccentricities, consistent with a recent study for V4 neurons. Our results suggest that MT neurons integrate inputs from constant-sized patches of V1 cortex.

Relationship between age at onset and magnetic resonance image-defined hyperintensities in mood disorders

OBJECTIVES

To examine in patients with mood disorders the relationship of age at onset with the location and degree of MRI-defined brain hyperintensities.

METHOD

Fifty-two patients diagnosed as having mood disorders and 14 controls participated in the study. Brain MR images were analyzed according to semiquantitative ratings for the anatomical distribution and severity of T2-weighted hyperintensities. We compared these hyperintensities among the three age- and sex-matched groups of late-onset mood disorder patients (LOM), early-onset mood disorder patients (EOM), and controls. The time since the onset of disorder was significantly longer in the EOM than in the LOM group. We also conducted linear multiple regression analysis using the severity of hyperintensities as dependent variable to determine whether the clinical features correlate with vascular pathology.

RESULTS

As for deep white matter hyperintensity (DWMH), LOM exhibited higher ratings than EOM; as for brain areas, significant between-group differences were detected in the bilateral frontal areas and in the left parieto-occipital area. No significant difference was observed between EOM and controls. As for periventricular hyperintensity, there was no difference among the three groups. We obtained a significant regression model to predict DWMH ratings; age, number of ECTs, and LOM were selected as significant variables.

CONCLUSION

The present study suggests that the time since the onset of disorder does not affect the development of white matter lesions, but that white matter lesions are associated with late-onset mood disorders. The frontal areas and the left parieto-occipital area would be important for the development of late-onset mood disorders.

Spatial frequency integration for binocular correspondence in macaque area V4

Neurons in the primary visual cortex (V1) detect binocular disparity by computing the local disparity energy of stereo images. The representation of binocular disparity in V1 contradicts the global correspondence when the image is binocularly anticorrelated. To solve the stereo correspondence problem, this rudimentary representation of stereoscopic depth needs to be further processed in the extrastriate cortex. Integrating signals over multiple spatial frequency channels is one possible mechanism supported by theoretical and psychophysical studies. We examined selectivities of single V4 neurons for both binocular disparity and spatial frequency in two awake, fixating monkeys. Disparity tuning was examined with a binocularly correlated random-dot stereogram (RDS) as well as its anticorrelated counterpart, whereas spatial frequency tuning was examined with a sine wave grating or a narrowband noise. Neurons with broader spatial frequency tuning exhibited more attenuated disparity tuning for the anticorrelated RDS. Additional rectification at the output of the energy model does not likely account for this attenuation because the degree of attenuation does not differ among the various types of disparity-tuned neurons. The results suggest that disparity energy signals are integrated across spatial frequency channels for generating a representation of stereoscopic depth in V4.

Brain metabolic changes associated with predispotion to onset of major depressive disorder and adjustment disorder in cancer patients--a preliminary PET study

OBJECTIVES

To explore neurobiological risk factors for major depressive disorder (MDD) and adjustment disorder in cancer patients by examining regional brain metabolism before psychiatric manifestation using positron emission tomography and by prospectively observing depressive and anxiety symptoms.

METHOD

Cancer patients who showed no psychiatric symptoms when they underwent 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) were followed up for one year using the Hospital Anxiety and Depression Scale (HADS). Fourteen patients who showed high HADS scores and 14 patients who showed low HADS scores were assessed by a psychiatrist 2 years after the PET scan and grouped into the deterioration group (n=10) and the no-change group (n=9). 18F-FDG PET images were analyzed to examine the difference in local brain glucose metabolism between the two groups.

RESULTS

The deterioration group showed a decreased glucose metabolism in the right medial frontal gyrus (BA6) and an increased glucose metabolism in the right posterior cingulate (BA29), right anterior cingulate (BA25), left subcallosal gyrus (BA25), and left caudate compared with the no-change group.

CONCLUSION

Cancer patients who later developed MDD or adjustment disorder showed regional brain metabolic changes. These regions may be associated with vulnerability to the onset of MDD or adjustment disorder in cancer patients.

"Mobile Nurse" platform for ubiquitous medicine

OBJECTIVES

We introduce "Mobile Nurse" (MN) - an emerging platform for the practice of ubiquitous medicine.

METHODS

By implementing in a dynamic setting of daily life the patient care traditionally provided by the clinical nurses on duty, MN aims at integral data collection and shortening the response time to the patient. MN is also capable of intelligent interaction with the patient and is able to learn from the patient's behavior and disease sign evaluation for improved personalized treatment.

RESULTS

In this paper, we outline the most essential concepts around the hardware, software and methodological designs of MN. We provide an example of the implementation, and elaborate on the possible future impact on medical practice and biomedical science research.

CONCLUSIONS

The main innovation of MN, setting it apart from current tele-medicine systems, is the ability to integrate the patient's signs and symptoms on site, providing medical professionals with powerful tools to elucidate disease mechanisms, to make proper diagnoses and to prescribe treatment.

Reliability of recalled self-report on headache intensity: investigation using ecological momentary assessment technique

Recalled evaluation of headache intensity is often affected by several factors. Recently, computerized ecological momentary assessment (EMA) has been developed to avoid such problems as recall bias. Here, we compared recalled headache intensity with momentary headache intensity using EMA in tension-type headache (TTH). Forty patients with TTH wore watch-type computers for 1 week to record momentary headache intensity and also rated their headache intensities by recall. We calculated intraclass correlation coefficients between recalled headache intensity and indices from EMA recordings in the whole study population and in two subgroups divided by variability of momentary headache intensity. The results showed that consistency and agreement of momentary and recalled headache intensity were low, and this was especially marked in the subjects whose headache varied widely. These observations suggested that variability of headache intensity may affect recall of headache intensity and this should be taken into consideration in both clinical and research settings.

[Use of a balloon occlusion catheter for descending aortic aneurysm after total arch replacement using the elephant trunk technique]

A 74-year-old man who had previously undergone prosthetic graft replacement of the total aortic arch using the elephant trunk technique and of the abdominal aorta was admitted to our hospital for surgical treatment of descending aortic aneurysm. Computed tomography (CT) on admission revealed descending aortic aneurysm of 6.5 cm in diameter, and the previously placed prosthetic graft was detected in the aneurysm. Surgery for the descending aorta was performed under femoro-femoral partial bypass. During the operation, a balloon occlusion catheter introduced through the right brachial artery into the 'elephant trunk' graft was inflated before the aneurysm was opened, then the previously placed prosthetic graft was cross-clamped and the descending aorta was replaced with a new prosthetic graft with usual fashion. The postoperative course was uneventful.

[Aortic root replacement in Marfan syndrome with hemophilia A]

A 34-year-old man with Marfan syndrome was admitted to our hospital for surgical treatment of aortic regurgitation due to annuloaortic ectasia. He had no history of bleeding complications. Preoperative investigation revealed a slight prolongation of an activated partial thromboplastin time, which went unnoticed. He underwent aortic root replacement with a composite valve graft. During the operation, he had excessive bleeding due to coagulopathy after the termination of cardiopulmonary bypass, and needed a large amount of blood transfusion to obtain hemostasis. Before his discharge from our hospital, he was diagnosed as mild hemophilia A because of the decline in his factor VII level. To our knowledge, there has been no published case of cardiac operations in Marfan syndrome with hemophilia A.

[Coronary artery bypass grafting in a patient with right aortic arch; report of a case]

A 60-year-old man was admitted to another hospital because of chest oppression on effort. Chest X-ray showed radiographic evidence of a right aortic arch and double vessel coronary artery disease with 50% stenosis in the left main trunk was diagnosed by coronary angiography. He was transferred to our institute for surgical treatment of angina pectoris. Preoperatively, multi-detector row computed tomography (CT) was performed and it revealed a right aortic arch and an aberrant left subclavian artery with narrow left internal thoracic artery. A right internal thoracic artery was well demonstrated. Therefore, conventional coronary artery bypass grafting using a right internal thoracic artery and a saphenous vein graft was performed and his postoperative course was uneventful.

HPA axis normalization, estimated by DEX/CRH test, but less alteration on cerebral glucose metabolism in depressed patients receiving ECT after medication treatment failures

OBJECTIVE

To examine the clinical effects of electroconvulsive therapy (ECT) on depressed patients with medication treatment failures, we investigated the alterations in hypothalamic-pituitary-adrenocortical (HPA) function and regional cerebral metabolism rate of glucose (rCMRGlu) after ECT in these patients.

METHOD

Before and after ECT, the combined dexamethasone/corticotrophin-releasing hormone (DEX/CRH) test was administered to seven patients who were referred for ECT. In the same patients, (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) was also assessed.

RESULTS

Cortisol response in the DEX/CRH test significantly decreased after a successful ECT. A significant hypometabolism in various frontal regions and hypermetabolism in the parietal regions of these patients when compared with controls remained after ECT.

CONCLUSION

Depressed patients who failed trials of antidepressant medication showed a remission with ECT that was accompanied by resolution of HPA dysregulation. However, measures of cerebral brain metabolism did not resolve.

[Beating heart surgery for ischemic mitral regurgitation: report of a case]

A 51-year-old man was admitted to our hospital because of dyspnea. Coronary angiography revealed triple vessel disease and echocardiography demonstrated severe mitral regurgitation with poor left ventricular function. Under a diagnosis of ischemic mitral regurgitation, on-pump beating mitral annuloplasty and coronary artery bypass grafting using the normothermic retrograde continuous coronary sinus perfusion of oxygenated blood was performed in order to prevent reperfusion injury. The patient was easily weaned from cardiopulmonary bypass and his postoperative course was uneventful. Because of the advantages of this procedure (e.g., no reperfusion injury, testing of the mitral valve repair is done in real physiologic conditions with beating tonus), on-pump beating heart surgery seems a good surgical option for ischemic mitral regurgitation with poor left ventricular function.

[One-staged operation for mitral regurgitation and annuloaortic ectasia without aortic regurgitation with Marfan syndrome; report of a case]

A 32-year-old man with Marfan syndrome was admitted to our hospital for detail examination of congestive heart failure. Doppler echocardiography showed severe mitral regurgitation due to prolapse of posterior mitral leaflet. Annuloaortic ectasia without aortic regurgitation was also detected by aortography. Considering the future operative need for aortic root and ascending aorta, we performed mitral valve replacement with a mechanical valve and preventive concomitant aortic root replacement with a composite valve graft. His postoperative course was uneventful. Optimal surgical treatment of mitral regurgitation and annuloaortic ectasia in Marfan syndrome is controversial because the underlying connective tissue defect theoretically might compromise repair durability. Several surgical options for mitral regurgitation and annuloaortic ectasia in Marfan syndrome are discussed.

[Off-pump coronary artery bypass grafting via a left thoracotomy in a patient with left main trunk disease]

We report a case of multiple coronary artery bypass grafting (CABG) via a left thoracotomy without cardiopulmonary bypass. A 54-year-old female with unstable angina pectoris associated with left main trunk disease underwent emergency CABG. Because the patient had a history of total arch and aortic root replacement due to type A aortic dissection, a left thoracotomy approach was selected. The proximal end of the Y-shaped saphenous vein graft was anastomosed to the left subclavian artery, rather than to the descending aorta, owing to the remaining aortic dissection. The distal end of the Y-shaped saphenous vein graft was anastomosed to the left anterior descending artery and the posterolateral branch without cardiopulmonary bypass. The postoperative course was uneventful. The results of this surgery seem to indicate that off-pump CABG via a left thoracotomy is a viable technique, especially for patients undergoing repeat CABG.

Secondary mitral valve replacement in antiphospholipid syndrome and chronic renal failure

A 48-year-old woman admitted with progressive dyspnea had previously been diagnosed with systemic lupus erythematosus, antiphospholipid syndrome, and chronic renal failure, and had undergone mitral valve replacement with a Carpentier-Edwards pericardial bioprosthesis for mitral insufficiency 9 years before. She suffered a cerebral infarction 5 years earlier, despite appropriate anticoagulant therapy. On admission, echocardiography showed severe bioprosthetic stenosis. Repeat mitral valve replacement was conducted using a Mosaic bioprosthesis. On postoperative day 2, when heparinization was commenced, she suddenly had an epileptic fit. She also developed ischemic necrosis of the fingers and toes, considered secondary to microthrombosis. Aspirin was administered and heparin replaced by warfarin sodium. Necrosis gradually disappeared, and she was discharged 3 months after surgery. The original bioprosthesis showed degenerative changes with significant thrombus formation on cusps, thought to be mainly due to her hypercoagulable state. Considering the thrombophilic tendency in patients with antiphospholipid syndrome, strict management of anticoagulant therapy is required.

A new procedure for chronic atrial fibrillation: bilateral appendage-preserving maze procedure

BACKGROUND

Atrial transport and atrial natriuretic peptide secretion is severely reduced from normal after the maze III procedure. To improve these factors, we developed a bilateral appendage-preserving maze procedure (BAP-maze).

METHODS

Forty-six patients with chronic atrial fibrillation who underwent the BAP-maze procedure were compared with 40 patients who underwent the maze III procedure. The ratio of the peak velocity of the A and E waves of transmitral flow (transthoracic pulsed Doppler echocardiography), the left atrial appendage ejection fraction (transesophageal echocardiography), and the atrial natriuretic peptide secretory reserve during treadmill exercise test were measured at 6 months postoperatively.

RESULTS

Sinus rhythm was restored in 44 patients (95.7%) by the BAP-maze procedure and in 39 patients (97.5%) by the maze III procedure. The ratio of the peak velocity of the A and E waves was 0.52 +/- 0.22 in the BAP-maze group and 0.25 +/- 0.19 in the maze III group (p < 0.0001). The left atrial appendage ejection fraction was 44.7% +/- 11.5%, and the atrial natriuretic peptide secretory reserve was greater in the BAP maze group (p = 0.037).

CONCLUSIONS

The BAP-maze procedure improved atrial transport and atrial natriuretic peptide secretion as well as simplifying the maze operation, without decreasing its effectiveness against atrial fibrillation.

Relationship between trait anxiety, brain activity and natural killer cell activity in cancer patients: a preliminary PET study

The purpose of this study is to examine the relationship between psychological factors, regional brain activity and natural killer cell activity (NKA). Eight patients with malignant diseases were studied by FDG-PET under a resting condition. NKA and degree of anxiety and depression were measured using Taylor's manifest anxiety scale (MAS) and Zung's self-rating depression scale (SDS). Linear correlation of NKA and psychological measures to the regional brain metabolism in cancer patients was examined using statistical parametric mapping (SPM). Positive linear correlation between NKA and regional metabolic rate ratios was identified in the visual association cortex, anterior cingulate gyrus (CG) and sensorimotor area, and negative correlation was identified in the inferolateral prefrontal cortex (ILPFC), prefrontal cortex (PFC), orbitofrontal cortex (OFC) and anterior temporal cortex. Positive linear correlation to the MAS score was identified in the visual association cortex, anterior CG, primary sensorimotor area and the posterior parietal cortex, and negative correlation was detected in the ILPFC, PFC, OFC and anterior temporal cortex. The NKA and MAS scores positively correlated with each other (p<0.001). The result might serve as supporting data for a hypothesis that psycho-immune interaction is also mediated by the cerebral cortex and limbic system.

Depressive state and regional cerebral activity in cancer patients - a preliminary study

BACKGROUND

The aim of this study was to investigate influences of depressive states, chemotherapy and existence of remaining tumors on the regional brain activity of cancer patients.

MATERIAL AND METHODS

Positron emission tomography with 18F-fluorodeoxyglucose was performed on 21 patients with various types of cancer. Their brain images were compared to 10 age- and gender-matched control data using statistical parametric mapping (SPM). The patients were subgrouped into the with and without depression based on the scores on Zung's self-rating depression scale (SDS), with and without previous chemotherapy, and with and without existence of remaining tumors.

RESULTS

Significant metabolic reduction was detected in the cingulate gyrus, prefrontal, dorsolateral prefrontal, temporoparietal cortices and basal ganglia in cancer patients. These findings were close to known lesions of major depression. Intra-group comparisons showed that these hypometabolic findings were associated with the depth of depressive state. Influences of chemotherapy and remaining tumors on the cerebral cortex seemed to be weaker than that of psychological factors.

CONCLUSIONS

The present pilot study suggests that frontal hypoactivity commonly seen in cancer patients is likely to be associated with depression rather than chemotherapy or remaining tumors. A brain mapping technique might be useful in evaluating neuropsychiatric problems in cancer patients.

Mitral insufficiency associated with primary antiphospholipid syndrome and chronic renal failure

We report a case of 52-year-old woman with primary antiphospholipid syndrome who developed mitral insufficiency and chronic renal failure. Continuous ambulatory peritoneal dialysis was started preoperatively due to thrombocytopenia that was aggravated by hemodialysis. Mitral annuloplasty was performed since the mitral valve was not severely damaged. Her postoperative hemodynamics were stable, and anticoagulant therapy was controlled easily. She recovered from severe thrombocytopenia while on continuous ambulatory peritoneal dialysis. Valvular heart disease is a well known feature of primary antiphospholipid syndrome, and there have been several reports about valve replacement in patients who had antiphospholipid syndrome with or without systemic lupus erythematosus. However, valve repair has been reported in only a few such patients. We believe that valve repair is better than valve replacement in patients with antiphospholipid syndrome because of its hypercoagulable tendency. In addition, it seems that continuous ambulatory peritoneal dialysis is a suitable method for the perioperative management of patients with antiphospholipid syndrome who suffer from chronic renal failure as well as thrombocytopenia, and require cardiac surgery under cardiopulmonary bypass.

Use of A heparin-coated circuit for extracorporeal circulation with selective cerebral perfusion

The use of selective cerebral perfusion with a heparin-coated extracorporeal circuit has not been reported. We developed a unique extracorporeal circulation system that can be used for selective cerebral perfusion based on an existing heparin-coated circuit with a centrifugal pump for general open-heart surgery and a heparin-coated oxygenator without venous drainage by gravity. Between July 1994 and December 1999, this system was used for 12 patients undergoing surgery for true aortic arch aneurysm. The dose of heparin used was reduced to maintain minimum activated clotting time above 300 sec during extracorporeal circulation. One patient suffered a stroke, and one patient had transient postoperative neurologic deficit. One patient died suddenly of ventricular arrhythmia on the 11th postoperative day. The circuit remained thrombus-free. Selective cerebral perfusion with a heparin-coated bypass circuit was safe and very easy to perform after a simple modification of a standard circuit for open-heart surgery.

The effect of a traditional Chinese prescription for a case of lung carcinoma

OBJECTIVE

To examine the effectiveness of Ninjin Yoei To (NYT; Ren-Shen-Yang-Rong-Tang in Chinese medicine; Kotaro Pharmaceutical Co., Ltd., Osaka, Japan), one of the traditional herbal medicines, against lung carcinoma.

SETTING

The Nursing Center Himawari DESIGN, PATIENT, AND PREPARATION: The regular dosage of NYT (15 g/d) was prescribed for 7 weeks to one elderly patient with lung carcinoma. The daily standard dose of NYT is prepared from dried extract obtained from 12 crude natural substances, ginseng, cinnamon bark, Japanese angelica root, astragalus root, peony root, citrus unshiu peel, rehmannia root, polygala root, atractylodes rhizome, schisanda fruit, poria sclerotium, and glycyrrhiza. NYT is certified by the Japanese Ministry of Health and Welfare.

RESULTS

The tumor marker levels (CEA and CA19-9) decreased and the scores of yin-yang and xu-shi inverted from negative and positive during 7 weeks. The patient's cough disappeared and her appetite recovered.

CONCLUSION

NYT has a positive effect on life expectancy for patients with malignancy. The diagnostic scoring system in yin-yang and xu-shi and prescription of Chinese herb may be available to gain control over a patient's health.

Assessment of patients by DSM-III-R and DSM-IV in a Japanese psychosomatic clinic

BACKGROUND

The aim of this study was to investigate the clinical features of psychosomatic disorders in Japan.

METHODS

A total of 1,432 outpatients (515 males and 917 females; 9-95 years of age, mean age 36) attending a psychosomatic clinic for the first time were assessed by the DSM-III-R or DSM-IV semistructured interview.

RESULTS

Major ICD-10 diagnoses found were eating disorder, other anxiety disorders, autonomic nervous dysfunction, somatoform disorders, and irritable bowel syndrome. The most frequent diagnosis on the DSM-III-R and DSM-IV axis I was 'somatoform disorders not otherwise specified', followed by bulimia nervosa, 'depressive disorder not otherwise specified', anorexia nervosa, conversion disorder, major depression or depressive disorder, 'panic disorder with agoraphobia', and 'psychological factors affecting physical or medical condition'. On axis II, 11-17% of the patients met the criteria for personality disorder. On axis IV, 78-80% had mild or moderate psychosocial stress; major psychosocial and environmental problems classified by the DSM-IV were the problems with primary supports and occupation.

CONCLUSIONS

The results seem to reinforce the belief that the diagnoses on the DSM-III-R and DSM-IV axis I are inadequate for describing psychosomatic phenomena. A new diagnostic system in combination with the multidimensional assessments by the DSM-III-R and DSM-IV is needed to form the common guidelines of diagnoses and therapies in psychosomatic medicine.

Decrease in serum cortisol during yoga exercise is correlated with alpha wave activation

We examined changes in brain waves and blood levels of serum cortisol during yoga exercise in 7 yoga instructors and found that alpha waves increased and serum cortisol decreased. These two measures were negatively correlated (r = -.83). Comparison with a control group of nonpractitioners is desirable.

Improvement of C-reactive protein levels and body temperature of an elderly patient infected with Pseudomonas aeruginosa on treatment with Mao-bushi-saishin-to

OBJECTIVE

To examine the effectiveness of Mao-bushi-saishin-to (Ma-Huang-Fu-Zi-Xi-Xin-Tang in Chinese medicine) (Tochimototenkaido Co. Ltd., Osaka, Japan), one of the traditional herbal medicines, against resistant bacterial infection.

SETTING

The Nursing Center Himawari, Izumo, Japan DESIGN, PATIENT, AND PREPARATION: Half of the standard dose of Mao-bushi-saishin-to was prescribed for 7 days to one elderly patient with fever and positive C-reactive protein (CRP) levels suffering from drug resistant Pseudomonas aeruginosa. The daily standard dose of Mao-bushi-saishin-to is prepared from 1200 mg of dried extract obtained from three crude drugs, Ephedrae Herba (4 g), Asiasari Radix (3 g), and Aconiti Tuber (1 g). It is certified by the Japanese Ministry of Health and Welfare.

RESULTS

The patient's fever and CRP level returned to normal levels.

CONCLUSIONS

In cases in which the fever does not fall in response to antibiotics for at least 3 days, half of the standard dose of Mao-bushi-saishin-to for 7 days might be worth trying to induce remission, especially for elder patients.

Duplex scanning to assess radial artery suitability for coronary artery bypass grafting

OBJECTIVE

Radial artery suitability in coronary artery bypass grafting was assessed using duplex ultrasonography.

SUBJECTS AND METHODS

The vascular condition along the entire radial artery was scanned in 55 patients, measuring the internal diameter and mean flow velocity at the wrist (distally), after ulnar artery branching (proximally), and midway between these 2 points (medially). Distally along the radial and ulnar arteries, the mean flow velocity was determined before and after radial artery occlusion.

RESULTS

Atherosclerotic changes were detected in 4 patients. The internal diameter was 3.1 +/- 0.4 mm proximally, 2.7 +/- 0.3 mm medially, 2.4 +/- 0.4 mm distally. The distal flow velocity was 0, and a reverse flow (peak velocity: 11.3 +/- 6.0 cm/s) was observed after the occlusion test in patients with an intact palmar arch, their mean flow velocity, 21.1 +/- 8.9 cm/s, and flow distally along the ulnar artery 58.0 +/- 23.4 ml/min, were higher after the occlusion test than before it 14.7 +/- 6.7 cm/s mean flow and 38.1 +/- 15.9 ml/min distally. This was not observed in patients with an interrupted palmar arch. In 15 patients, radial arteries could not be used because of their small internal diameter, lack of a radial artery, poor vascular condition, or an interrupted palmar arch evaluated using duplex scanning.

CONCLUSION

Reliable noninvasive assessment of radial artery anatomy and palmar arch continuity is thus possible using duplex ultrasonography.

Use of photic feedback as an adjunct treatment in a case of Miller Fisher syndrome

Photic Feedback treatment of a patient diagnosed with Miller Fisher syndrome has resulted in the rapid and permanent remission of symptoms. During Photic Feedback treatment, the CD20 appeared to be slightly increased. This may have been associated with changes in humoral immunity. The present clinical observation of a single patient suggests that Photic Feedback treatment should be investigated as a possible adjunct therapy for patients who suffer from polyneuropathies, such as Miller Fisher syndrome, within a carefully controlled clinical trial.

[Drug Compliance Scale. I. Development of the Drug Compliance Scale]

The failure of patients to comply with treatment regimens recommended by their physicians is a significant clinical problem. Researches on the assessment of compliance have, however, been precluded by methodological difficulties such as lack of adequate measures. The purpose of this study was to develop a self-administered questionnaire to evaluate drug compliance. First, questionnaire containing a 52-items complied by two doctors, a pharmacist and a nurse, was tested on 81 outpatients, all volunteers, attending the departments of psychosomatic medicine and internal medicine. Four items were temporarily removed for later analysis because they directly inquired about drug compliance (drug compliance items). The other 48 items were analyzed and three factors consisting of 26 items were further studied: expectation on taking medicine, rejection to taking medicine and seeking knowledge of drugs. Chronback's alpha coefficients representing internal consistency of the three factors were sufficiently high (ranging from .75 to .84). Furthermore, we preformed a simplified pill count to validate the 4 drug compliance items. There was a weak to moderate correlation between the result of pill count and each of 4 drug compliance items. A new self-administered questionnaire of 30 items was thus developed and named the Drug Compliance Scale.

[Drug Compliance Scale. II. Psychological factors affecting drug compliance in the department of psychosomatic medicine]

The purpose of this study was to investigate psychological factors affecting drug compliance in the department of psychosomatic medicine. Seventy-four outpatients were asked to answer a battery of self-administered questionnaire including the Drug Compliance Scale (DCS) that we had recently developed and other questionnaire evaluating psychological and vegetative symptoms, self-efficacy and attributional styles on the promotion of health and personality closely related to interpersonal relationships. Results of path analysis indicated that attributional styles and self-efficacy mainly affected three factors of DCS such as expectation on taking medicine, rejection to taking medicine and seeking knowledge of drugs, through which they influenced drug compliance, and also indicated that personality and self-efficacy mainly affected the stability of mood state, suggesting a further influence on drug compliance.

Psychosocial factors associated with peptic ulcer in aged persons

The relationship between psychosocial factors and the occurrence and aggravation of peptic ulcer was studied in elderly people. Thirty-nine (14 male) ulcer patients and 79 (30 male) elderly people aged 65 years and over and living in the community were tested. Information on health status, medication, lifestyle, and psychosocial status was obtained by means of interviews using a questionnaire and from the clinical records of the ulcer patients. The same questionnaire was distributed to the residents. Logistic regression analysis adjusting for age disclosed that peptic ulcer was significantly associated with having an occupation and low exercise practice in men. However, the relationship weakened below statistical significance after adjusting for some physical risk factors besides age. Low education was significant but low instrumental support fell short of statistical significance with peptic ulcer in women even after adjustment for several physical risk factors besides age. Thus, the specific psychosocial factors might be independently associated with the occurrence and aggravation of peptic ulcer in at least elderly women.

Heparin-coated circuits prevent renal dysfunction after open heart surgery

We examined whether heparin-coated (HC) circuits can improve the operative results in patients with chronic renal insufficiency.

SUBJECTS AND METHODS

Elective cardiac surgery was performed in 24 patients with a serum creatinine (Cr) level of at least 1.5 mg/dl. Uncoated circuits were used in 12 patients, and HC circuits were used in 12 patients. The results of surgery were compared between the two groups.

RESULTS

The mean preoperative Cr concentration was significantly higher in the HC group (2.3 vs 1.8 mg/dl). The heparin doses, protamine dose, and activated clotting times were significantly lower in the HC group. The mean blood loss was also less, although this difference was not significant. The postoperative increase in the Cr level was small in the HC group (2.3-->2.5 mg/dl) compared to that in the noncoated group (1.8-->2.3 mg/dl). Postoperative dialysis was not required in the 5 patients in the HC group with a preoperative Cr clearance less than 20 ml/min.

CONCLUSION

HC circuits and low-dose heparin can be used to maintain renal function after cardiopulmonary bypass, even in patients with severe kidney disease.

Coagulofibrinolysis during heparin-coated cardiopulmonary bypass with reduced heparinization

BACKGROUND

We examined the safety of reduced systemic heparinization during heparin-coated cardiopulmonary bypass by measuring coagulofibrinolitic indices, including fibrinopeptide A, which directly reflects fibrinogenesis.

METHODS

Twenty-four patients who had elective cardiac operations were perfused using a circuit coated with covalently bonded heparin. Twelve patients received 300 U/kg of heparin and the remaining 12 patients received 150 U/kg. Blood was obtained for the measurement of thrombin-antithrombin III complexes, fibrinopeptide A, plasmin-alpha 2 plasmin inhibitor complexes, and D-dimer preoperatively; after heparin administration; 10, 60, and 90 minutes after the start of bypass; after protamine administration; and 1, 3, 6, 12, and 24 hours after the end of bypass.

RESULTS

Preoperative, intraoperative, and postoperative variables including postoperative bleeding were not significantly different between the two groups. Further, there were no complications in either group. No significant differences between the two groups were noted for any hematologic index at any time point.

CONCLUSIONS

Reduced systemic heparinization combined with a heparin-coated cardiopulmonary bypass circuit is biochemically and clinically safe but does not reduce postoperative bleeding.

Use of heparin-coated cardiopulmonary bypass circuit with low-dose heparin reduces postoperative bleeding

Postoperative bleeding was examined in patients undergoing cardiopulmonary bypass with a heparin-coated circuit and low-dose heparin. Out of 150 patients who underwent cardiopulmonary bypass for longer than 90 minutes, 74 received a standard dose (300 IU/kg) of heparin with an uncoated circuit (group C) and 76 received a low-dose (150 IU/kg) of heparin with a heparin-coated circuit (group H). The coagulation and fibrinolytic systems were investigated in 24 patients. Re-opening of the chest due to bleeding was performed in 5 patients in group C (7%), but none of the patients in group H (p=0. 03). The median of blood loss in the first 12 hours after surgery was 292 ml in group C, and 216 ml in group H (p=0.006). There were no significant differences in the peak thrombin-antithrombin complex concentration between the two groups. The plasmin-alpha 2 plasmin inhibitor complex concentrations after protamine administration were 1.9 ng/ml (median) in group C and 1.1 ng/ml in group H (p=0.002). The use of heparin-coated cardiopulmonary bypass circuits with low-dose heparin suppressed the activation of fibrinolysis. This may explain the reduction in postoperative bleeding.

Assessment of ego state in anorexia nervosa and bulimia nervosa

To clarify the effects of ego states on anorexia nervosa (AN) and bulimia nervosa (BN), the questionnaire of the Tokyo University Egogram (TEG) with critical parent, nurturing parent, adult, free child and adapted child scales was administered to 32 female AN patients aged 14 to 32 years (mean age 20 years) and 49 female BN patients aged 14 to 33 years (mean age 23 years). The scores on the critical parent and adapted child scales for AN were significantly lower than those for BN. A multiple logistic regression analysis including all of the TEG scales, age, duration of illness and education showed that the adapted child scale significantly discriminated between AN and BN. The adaptive ego state is suggested for differentiating between the two disorders.