Low serum potassium concentration is a predictor of chronic kidney disease

AIMS

The aim of this study was to examine whether low serum potassium concentration could be a predictor of chronic kidney disease (CKD) in a community-based cohort.

MATERIALS AND METHODS

We enrolled 1001 subjects, median period of 5.7 years, and evaluated the risk factors for CKD, defined as estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m(2), and assessed whether low serum potassium concentration could predict CKD.

RESULTS

Compared with the subjects without development of CKD, age, body mass index, fasting plasma glucose, uric acid (UA), creatinine and serum sodium concentration were higher, and serum potassium concentration was lower in subjects with development of CKD. Univariate Cox regression analyses demonstrated that age, body mass index, fasting plasma glucose, UA, creatinine, serum sodium concentration and serum potassium concentration were associated with progression of CKD. Multiple Cox regression analysis revealed that age, gender, creatinine and serum potassium concentration were independent predictors of CKD after adjustment for covariates. When serum potassium concentration was below 4.0 mmol/l at baseline, hazard ratio (95% confidence interval) of developing CKD was 2.65 (2.04-3.44; p < 0.0001).

CONCLUSIONS

Serum potassium concentration could be a clinically relevant risk factor for the progression of CKD, defined as eGFR < 60 ml/min/1.73 m(2) , in healthy subjects.

Surface and intramural reentrant patterns during atrial fibrillation in the sheep

INTRODUCTION

This article is part of the Focus Theme of Methods of Information in Medicine on "Biosignal Interpretation: Advanced Methods for Studying Cardiovascular and Respiratory Systems".

BACKGROUND

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in humans and is predicted to dramatically increase its prevalence in the future. High-resolution mapping data and Fourier power spectral analysis with its dominant frequency support the hypothesis that AF in the structurally normal sheep heart and in some patients often presents organized drivers in the form of periodic surface re-entries or breakthroughs. Nevertheless, the dynamics of those surface patterns of activity, as well as their intramural components are still poorly understood.

OBJECTIVE

To present data on AF waves from the surface of isolated sheep hearts and discuss the interpretation of their intramural patterns.

METHODS

We used a combination of endocardial-epicardial optical mapping with phase and spectral analysis as well as computer simulation of the re-entrant activity in the myocardial wall.

RESULTS

Analysis of the surfaces' optical mapping data in the phase domain reveals that activation of the posterior left atrium (PLA) consisted of alternating patterns of breakthroughs and reentries. The patterns on the endocardial and epicardial PLA surface at any given moment of time of the AF could be either identical or not identical, and the activity in the thickness of the PLA wall is hypothesized to conform to either ectopic discharge or reentrant scroll waves, but a definite evidence for the presence of such mechanisms is currently lacking. A universal minimal-principle theory is shown in a computer model to result in a tendency of the axis of the scroll waves to align with the myocardial fibers inside the wall.

CONCLUSION

The tendency of filaments of scroll waves to align with myocardial fibers may contribute to the variety and intermittency of surface rotors seen in AF.

Diagnostic performance of plasma biomarkers in patients with acute intestinal ischaemia

BACKGROUND

The aim of this study was to evaluate the use of intestinal fatty acid binding protein (I-FABP) and traditional biomarkers in the early diagnosis of acute intestinal ischaemia of different causes.

METHODS

I-FABP, white blood cell (WBC) count, C-reactive protein, base deficit, lactate, lactate dehydrogenase, aspartate aminotransferase, creatine kinase and D-dimer were measured prospectively in consecutive patients suspected of having acute intestinal ischaemia. Biomarker levels were compared in patients with vascular and non-vascular ischaemia.

RESULTS

Two hundred and eight patients with a clinical suspicion of acute intestinal ischaemia were enrolled. Vascular intestinal ischaemia was diagnosed in 24 patients (11·5 per cent), non-vascular ischaemia in 62 (29·8 per cent) and non-ischaemic disease in 122 (58·7 per cent). The levels of most biomarkers (except WBC count and creatine kinase) were significantly higher in the vascular ischaemia group than in the other groups (P < 0·010). However, none of the biomarker levels differed between patients with non-vascular intestinal ischaemia and those with non-ischaemic disease. Receiver operating characteristic (ROC) curve analysis suggested that I-FABP was best at diagnosing vascular intestinal ischaemia (area under the curve 0·88).

CONCLUSION

Serum biomarkers may be useful in the diagnosis of vascular, but not non-vascular, intestinal ischaemia. Among them, I-FABP shows promise for detecting vascular ischaemia.

TWEAK/Fn14 pathway promotes a T helper 2-type chronic colitis with fibrosis in mice

Tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK), a TNF superfamily member, induces damage of the epithelial cells (ECs) and production of inflammatory mediaters through its receptor Fn14 in a model of acute colitis. In our current study of chronic colitis induced by repeated rectal injection of a hapten, we found that inflammation, fibrosis, and T helper 2 (Th2)-type immunity were significantly reduced in Fn14 gene knockout (KO) mice when compared with wild-type (WT) control mice. Expression of thymic stromal lymphopoietin (TSLP) was lower in Fn14 KO colon ECs than in WT ECs. TWEAK potentiates the induction of TSLP by interleukin-13 (IL-13) in colon explants from WT but not in Fn14 KO tissue. TSLP receptor KO mice exhibit milder chronic colitis, similar to that in Fn14 KO mice. TWEAK and IL-13 synergistically promote fibroblast proliferation. Thus we propose an IL-13-TWEAK/Fn14-TSLP axis as a key mechanism underlying chronic colitis with fibrosis.

Development of an (e,2e) electron momentum spectroscopy apparatus using an ultrashort pulsed electron gun

An (e,2e) apparatus for electron momentum spectroscopy (EMS) has been developed, which employs an ultrashort-pulsed incident electron beam with a repetition rate of 5 kHz and a pulse duration in the order of a picosecond. Its instrumental design and technical details are reported, involving demonstration of a new method for finding time-zero. Furthermore, EMS data for the neutral Ne atom in the ground state measured by using the pulsed electron beam are presented to illustrate the potential abilities of the apparatus for ultrafast molecular dynamics, such as by combining EMS with the pump-and-probe technique.

Spontaneous migration of a redundant nerve root accompanied by absorption of lumbar disk herniation. A case report

A redundant nerve root is defined as a large, elongated and tortuous nerve root commonly associated with severe lumbar spinal canal stenosis. Elongation of nerve roots as a result of mechanical trapping at stenotic level is assumed to be a possible mechanism. Here we present a case in a patient who showed a redundant nerve root above the level of a lumbar canal stenosis caused by disk herniation and redundancy spontaneously migrating to a lower lumbar stenosis level accompanied by absorption of the herniated disk as shown by magnetic resonance imaging (MRI). A 67-year-old Japanese woman presented with bilateral thigh/leg pain and intermittent claudication. A midsagittal T2-weighted MR image of the lumbar spine revealed severe spinal canal stenosis at the L3-4 and L4-5 levels. At the L3-4 level, central disk herniation compressed the dural tube. An MR image revealed redundant nerve roots just cranial to the severely compressed L3-4 level. A follow-up MRI study revealed regression of disk herniation at the L3-4 level. In contrast, there was no significant change of the stenosis at the L4-5 level. Sagittal T2-weighted MR imaging at follow-up revealed redundant nerve roots just cranial to the L4-5 level, whereas the redundant nerve roots cranial to the L3-4 level had disappeared. The MRI findings of the present case support the "squeeze" hypothesis as causative of redundant nerve roots.

Non-emissive plastic colour filters for fluorescence detection

We report the fabrication of non-emissive short- and long-pass filters on plastic for high sensitivity fluorescence detection. The filters were prepared by overnight immersion of titania-coated polyethylene terephthalate (PET) in an appropriate dye solution - xylene cyanol for short-pass filtering and fluorescein disodium salt for long-pass filtering - followed by repeated washing to remove excess dye. The interface between the titania and the dye molecule induces efficient quenching of photo-generated excitons in the dye molecule, reducing auto-fluorescence to negligible values and so overcoming the principal weakness of conventional colour filters. Using the filters in conjunction with a 505 nm cyan light-emitting diode and a Si photodiode, dose-response measurements were made for T8661 Transfluosphere beads in the concentration range 1 × 10(9) to 1 × 10(5) beads μL(-1), yielding a limit of detection of 3 × 10(4) beads μL(-1). The LED/short-pass filter/T8661/long-pass filter/Si-photodiode combination reported here offers an attractive solution for sensitive, low cost fluorescence detection that is readily applicable to a wide range of bead-based immunodiagnostic assays.

Inflammatory histopathogenesis of nasopalatine duct cyst: a clinicopathological study of 41 cases

OBJECTIVE

The aim of this study is to characterize immunohistochemical profiles of lining epithelia of nasopalatine duct cyst (NPC) as well as to correlate those findings with their clinicopathological features to understand the histopathogenesis of NPC.

MATERIALS AND METHODS

Forty-one surgical specimens from NPC were examined for clinical profiles and expression of keratin-7, 13, MUC-1, and P63 by immunohistochemistry, compared to radicular cyst (RC) and maxillary sinusitis.

RESULTS

Nasopalatine duct cyst was clinically characterized by male predominant occurrence: 44% of the cases involved tooth roots, and 70% with inflammatory backgrounds. Lining epithelia of NPCs without daughter cysts were immunohistochemically distinguished into three layers: a keratin 7-positive (+) ciliated cell layer in the surface, a keratin-13+ middle layer, and a MUC-1+/P63+ lower half, indicating that they were not respiratory epithelia, and the same layering pattern was observed in RC. However, those immunolocalization patterns of the main cyst lining with daughter cyst were exactly the same as those of daughter cyst linings as well as duct epithelia of mucous glands.

CONCLUSIONS

Two possible histopathogenesis of NPC were clarified: one was inflammatory cyst like RC and the other was salivary duct cyst-like mucocele.

Chair rising exercise is more effective than one-leg standing exercise in improving dynamic body balance: a randomized controlled trial

A randomized controlled trial was conducted to compare the effect of a one-leg standing exercise and a chair-rising exercise on body balance in patients with locomotive disorders. Thirty ambulatory patients (mean age: 66.6 years) were randomly divided into two groups (n=15 in each group): a one-leg standing exercise group and a chair-rising exercise group. All the participants performed calisthenics of the major muscles, a tandem gait exercise, and a stepping exercise. The exercises were performed 3 days per week, and the study period was 5 months. Physical function was evaluated at baseline and at one-month intervals. No significant differences in the baseline characteristics were observed between the two groups. After the 5-month exercise program, the timed up and go, one-leg standing time, and tandem gait time improved significantly in the one-leg standing exercise group, while the walking time and chair-rising time in addition to above parameters improved significantly in the chair-rising exercise group. The improvements in the walking time, chair-rising time, and tandem gait time were significantly greater in the chair-rising exercise group than in the one-leg standing exercise group. The present study showed that the chair-rising exercise was more effective than the one-leg standing exercise for improving walking velocity and dynamic body balance.

Comparison of contrast effect on the cochlear perilymph after intratympanic and intravenous gadolinium injection

BACKGROUND AND PURPOSE

3D-FLAIR imaging 24 hours after intratympanic gadolinium injection (IT-method) or 4 hours after IV injection (IV-method) has been used to visualize the endolymphatic hydrops in Ménière disease. The purpose of this study was to compare the degree of perilymph enhancement with the 2 methods and the perilymph contrast-effect difference with the IV-method in both sides in patients with unilateral Ménière disease.

MATERIALS AND METHODS

Sixty-one patients with Ménière disease or sudden SNHL were included in this study. Thirty-nine patients who underwent the unilateral IT-method (Gd-DTPA was diluted 8-fold with saline) and 22 patients who underwent the IV-method (a double-dose of Gd-HP-DO3A; 0.4 mL/kg body weight [ie, 0.2 mmol/kg body weight]) at 3T were analyzed retrospectively. Regions of interest of the cochlear perilymph and the medulla oblongata were determined on each image, and the signal-intensity ratio between the 2 (CM ratio) was subsequently evaluated. The differences in the CM ratio between the 2 methods (Student t test) and the IV-method CM ratio between the affected and unaffected sides in patients with unilateral Ménière disease (paired t test) were evaluated.

RESULTS

The IT-method CM ratio (2.98 ± 1.15, n = 39) was higher than the IV-method CM ratio (1.61 ± 0.60, n = 44; P < .001). In patients with unilateral Ménière disease who underwent the IV-method (n = 9), the CM ratio of the affected side (1.86 ± 0.74) was higher than that of the unaffected side (1.29 ± 0.31, P < .05).

CONCLUSIONS

In general, the IT-method provides higher perilymph enhancement than the IV-method. In the patients with unilateral Ménière disease who underwent the IV-method, the affected side had a higher contrast effect.

Low serum bilirubin concentration in haemodialysis patients with Type 2 diabetes

AIMS

Previous studies have implicated reduced serum bilirubin concentrations in the development of cardiovascular disease. The aim of this study was to examine whether bilirubin may explain the high incidence of vascular complications in haemodialysis patients with Type 2 diabetes.

METHODS

We compared serum bilirubin concentrations, as well as other known aetiological risk factors for cardiovascular disease, in 206 Type 2 diabetes patients on haemodialysis with those in 741 Type 2 diabetes patients not receiving haemodialysis, and evaluated the association between serum bilirubin concentration and cardiovascular disease incidence.

RESULTS

Incidences of cardiovascular disease and systolic blood pressure were higher; however, BMI and serum total cholesterol were lower in haemodialysis patients compared with those in patients without haemodialysis. Serum total (0.30 ± 0.10 vs. 0.74 ± 0.26 mg/dl, 0.005 ± 0.002 vs. 0.013 ± 0.004 mmol/l, P < 0.0001) and indirect (0.17 ± 0.08 vs. 0.70 ± 0.23 mg/dl, 0.003 ± 0.001 vs. 0.012 ± 0.004 mmol/l, P < 0.0001) bilirubin were lower in haemodialysis patients compared with those in patients without haemodialysis. Stepwise regression analysis demonstrated that age (β = 0.109, F = 5.959, P < 0.05), duration of diabetes (β = -0.112, F = 6.048, P < 0.05), sex (β = -0.123, F = 8.623, P < 0.05), cardiovascular disease events (β = -0.099, F = 5.131, P < 0.05) and presence of haemodialysis (β = -0.626, F = 201.727, P < 0.01) were independent factors for serum total bilirubin. Logistic regression demonstrated that age (OR 1.089, 95% CI 1.044-1.136; P < 0.0001), duration of diabetes (OR 1.029, 95% CI 1.001-1.059; P = 0.0423), body mass index (OR 1.115, 95% CI 1.001-1.242; P = 0.0487), habit of smoking (OR 2.445, 95% CI 1.046-5.716; P = 0.0391) and serum total bilirubin (OR 0.192, 95% CI 0.037-0.989; P = 0.0484) were independent factors for cardiovascular disease events.

CONCLUSIONS

Low serum bilirubin concentration could be one of the important factors for the high incidence of cardiovascular disease in Type 2 diabetes patients receiving haemodialysis.

Nasu-Hakola disease with a splicing mutation of TREM2 in a Japanese family

BACKGROUND

  Nasu-Hakola disease (NHD) is a rare autosomal recessive disorder, characterized by a combination of progressive presenile dementia and formation of multifocal bone cysts, caused by genetic mutations of DAP12 and TREM2, which constitute a receptor/adapter signaling complex expressed on osteoclasts, dendritic cells, macrophages, and microglia. No Japanese patients with TREM2 mutations have been reported previously.

METHODS

  We reported three siblings affected with NHD in a Japanese family. Amongst them, two died of NHD during the fourth decade of life. The analysis of genomic DNA, cDNA cloning, and western blot of lymphocyte proteins was performed on samples of the living patient. The transcriptome was studied in the autopsied brain of one patient.

RESULTS

  We identified a homozygous conversion of a single nucleotide T to C at the second position of intron 3 in the splice-donor consensus site (c.482+2T>C) of the TREM2 gene, resulting in exon 3 skipping and aberrant expression of truncated proteins. We identified 136 upregulated genes involved in inflammatory response and immune cell trafficking and 188 downregulated genes including a battery of GABA receptor subunits and synaptic proteins in the patient's brain.

CONCLUSIONS

  This is the first report of a Japanese NHD family caused by a splicing mutation of TREM2 that induces both neuroinflammation and neurodegeneration.

Complication of adenoid cystic carcinoma and sialolithiasis in the submandibular gland: report of a case and its etiological background

The authors report a case of adenoid cystic carcinoma (ACC) complicated with sialolithiasis of the submandibular gland. The patient was a 43-year-old female with a history of papillotubular carcinoma of the breast almost at the same time. She had noticed a swelling in her sublingual area for 10 years, which was later diagnosed by her dentist to be due to a sialolith in the left submandibular gland. After several years of observation, the patient was referred to have her left submandibular gland, containing the stone, surgically removed with a diagnosis of atrophic sialadenitis. Histopathologically, the submandibular gland was extensively replaced with fibrous granulation tissue, in which there were small but invasive foci of ACC. The present case indicates that ACC could arise in the background of chronic sialadenitis. It is suggested that long-standing sialadenitis cases should be carefully examined to exclude suspicion of malignancy before surgery.

Abstract P4-10-11: Nobel Approach for Breast Conserving Surgery after Primary Systemic Therapy: Real-Time Virtual Navigation

Background:

Breast-conserving surgery after primary systemic therapy (PST) has become a widely acceptable procedure for locally advanced breast cancers. Sometimes it is difficult to determine the appropriate resection-line at the time of surgical operation because of tumor size reduction or indistinct boundary of the tumor. Moreover we cannot detect tumors in cases with complete response. That was why we developed a new navigation technique using real-time image reconstruction.

Materials and methods: Multi-detector row computed tomography (MD-CT) has been performed for all breast cancer patients in our institute. DICOM images of MD-CT were analyzed by image processing software ‘OsiriX'. OsiriX is an open source software which anyone can download from website (http://www. osirix-viewer.com). OsiriX has been specifically designed for navigation and visualization of multimodality and multidimensional images. We used 3D volume rendering images. At the time of surgery, pre-PST volume rendering images ware superimposed directly on the patients’ skin from projector which was connected to a personal computer in the operating room.

Results: We could see ‘real-time’ rendering images (from skin to organ by layer to layer) on the patient's body. By using pre-PST imaging data, we could recognize precise tumor area and could perform breast conserving surgery safer and easier than before.

Conclusion: Using 3D reconstruction MD-CT images which were obtained before PST, ‘real-time’ virtual navigation was helpful to determine the resection-line for clear surgical margin in breast-conserving surgery after PST. This new technique does not need some expensive equipments and easily performed by surgeon. Ordinary personal computer and projector make it possible to demonstrate a new environment in surgical operation.

Complementary synaptic distribution of enzymes responsible for synthesis and inactivation of the endocannabinoid 2-arachidonoylglycerol in the human hippocampus

Clinical and experimental evidence demonstrates that endocannabinoids play either beneficial or adverse roles in many neurological and psychiatric disorders. Their medical significance may be best explained by the emerging concept that endocannabinoids are essential modulators of synaptic transmission throughout the central nervous system. However, the precise molecular architecture of the endocannabinoid signaling machinery in the human brain remains elusive. To address this issue, we investigated the synaptic distribution of metabolic enzymes for the most abundant endocannabinoid molecule, 2-arachidonoylglycerol (2-AG), in the postmortem human hippocampus. Immunostaining for diacylglycerol lipase-α (DGL-α), the main synthesizing enzyme of 2-AG, resulted in a laminar pattern corresponding to the termination zones of glutamatergic pathways. The highest density of DGL-α-immunostaining was observed in strata radiatum and oriens of the cornu ammonis and in the inner third of stratum moleculare of the dentate gyrus. At higher magnification, DGL-α-immunopositive puncta were distributed throughout the neuropil outlining the immunonegative main dendrites of pyramidal and granule cells. Electron microscopic analysis revealed that this pattern was due to the accumulation of DGL-α in dendritic spine heads. Similar DGL-α-immunostaining pattern was also found in hippocampi of wild-type, but not of DGL-α knockout mice. Using two independent antibodies developed against monoacylglycerol lipase (MGL), the predominant enzyme inactivating 2-AG, immunostaining also revealed a laminar and punctate staining pattern. However, as observed previously in rodent hippocampus, MGL was enriched in axon terminals instead of postsynaptic structures at the ultrastructural level. Taken together, these findings demonstrate the post- and presynaptic segregation of primary enzymes responsible for synthesis and elimination of 2-AG, respectively, in the human hippocampus. Thus, molecular architecture of the endocannabinoid signaling machinery supports retrograde regulation of synaptic activity, and its similar blueprint in rodents and humans further indicates that 2-AG's physiological role as a negative feed-back signal is an evolutionarily conserved feature of excitatory synapses.

Effect of cellulase supplementation in low-crude protein diets on performance, nitrogen excretion, fat deposition, hepatic lipogenic and lipolytic enzyme activity in broilers

1. Two experiments were conducted to investigate the effect of dietary enzyme supplementation of a low-protein diet on performance, nitrogen excretion, fat deposition, hepatic lipogenic and lipolytic enzyme activity in 7-21- (Experiment 1) and 21-42-d-old (Experiment 2) male broiler chicks. 2. Chicks were given diets containing 210 g (Experiment 1) or 170 g (Experiment 2) crude protein (CP)/kg (Control), amino acid-fortified diets 190 g (Experiment 1) and 150 g (Experiment 2) CP/kg (Low-protein), and a low-protein diet supplemented with 1000 U/kg of cellulase. 3. In Experiment 1, growth performance and abdominal fat deposition were not affected by dietary treatments, and birds given low-protein diets excreted less nitrogen. The activities of hepatic lipogenic and lipolytic enzymes were not different among the three dietary groups. 4. In Experiment 2, the dietary treatment did not affect growth performance or abdominal fat weight. Nitrogen excretion was significantly lower in chicks given the 150 g/kg CP diet than those on the 170 g/kg CP diet; however, nitrogen retention was no different among the treatments. Dietary CP and enzyme supplementation did not significantly affect hepatic enzyme activities. 5. These results suggest that CP content in the broiler diet can be reduced by 20 g/kg without lowering performance by the supplementation of crystalline amino acids, and can reduce nitrogen excretion by about 25%. Cellulase supplementation of a low-CP diet slightly lowered abdominal fat deposition; however, it did not significantly affect hepatic lipogenic and lipolytic enzyme activity.

A novel nonsecosteroidal VDR agonist (CH5036249) exhibits efficacy in a spontaneous benign prostatic hyperplasia beagle model

To date, there have been no reports showing the efficacy of nonsecosteroidal vitamin D receptor (VDR) agonists in a benign prostatic hyperplasia (BPH) animal model. To examine the efficacy of CH5036249, a novel nonsecosteroidal VDR agonist, we orally administered the compound at 0.03 microg/kg to a beagle model with spontaneous BPH. Prostate volume was checked by rectal ultrasonic probe periodically during 11 months of administration and the prostate tissues histologically examined. CH5036249 inhibited prostate growth in two out of three dogs compared with vehicle-treated dogs. In the prostate specimens, substantial atrophy of the epithelium was observed in all dogs administered CH5036249. At the dose given, serum calcium levels slightly increased in the CH5036249-treated dogs but stayed within a normal range. We next examined the cell growth inhibition of CH5036249 using human prostate stromal cells and found the cell growth inhibitory activity of CH5036249 to be comparable to that of 1alpha,25(OH)2D3. The bioavailability from oral administration in rats was 95.1% with a t1/2 of 17.6 h. Both micro-AMES and micronucleus tests were negative. Although the results are still preliminary, we consider the novel nonsecosteroidal VDR agonist CH5036249 to be a possible new drug candidate for the treatment of BPH in humans.

Cerebral oxygenation in the beach chair position before and during general anesthesia

AIM

Ischemic brain damage related to the beach chair position is a matter of concern. The current study was designed to evaluate whether the beach chair position before and during general anesthesia differentially induces changes in cerebral oxygenation as determined by near-infrared spectroscopy (NIRS) in surgical patients.

METHODS

We evaluated brain tissue oxygen index (TOI) values using the NIRS monitor NIRO-200TM in the beach chair position the day before and during general anesthesia. Thirty patients with normal preoperative TOI values undergoing shoulder surgery were enrolled. The initial TOI measurement in the supine position after 10 min rest or 10 min after tracheal intubation was followed by measurements after 5 min each in the 30-degree and subsequently 60-degree head-up tilt positions. During general anesthesia, patients were mechanically ventilated to obtain normocapnia under inhalation of 1.5% sevoflurane in 50% oxygen. Mean blood pressure (MAP) was measured non-invasively in the arm at heart level and was maintained above 60 mmHg with phenylephrine.

RESULTS

Preoperative TOI values and preoperative MAP were within the normal range in the study population. MAP decreased upon anesthesia but did not further change when the patient was placed in the 30- and 60-degree head-up tilt positions. Heart rate also decreased upon anesthesia. However, TOI values did not change with induction of general anesthesia or placement of the patients in the beach chair position.

CONCLUSION

Under general anesthesia, the beach chair position does not alter cerebral oxygenation in patients showing normal preoperative cerebral TOI values.