Health effects of indoor fluoride pollution from coal burning in China

The combustion of high fluoride-content coal as an energy resource for heating, cooking, and food drying is a major exhaust emission source of suspended particulate matter and fluoride. High concentrations of these pollutants have been observed in indoor air of coal-burning families in some rural areas in China. Because airborne fluoride has serious toxicological properties, fluoride pollution in indoor air and the prevalence of fluorosis have been analyzed in a fluorosis area and a healthy nonfluorosis area in China and in a rural area in Japan. For human health, fluoride in indoor air has not only been directly inhaled by residents but also has been absorbed in stored food such as corn, chilies, and potatoes. In the fluorosis area in China, concentrations of urinary fluoride in the residents have been much higher than in the nonfluorosis area in China and in the rural area in Japan. In the fluorosis area, almost all elementary and junior high school students 10-15 years of age had dental fluorosis. Osteosclerosis in the skeletal fluorosis patients was very serious. Urinary deoxypyridinoline in rural residents in China was much higher than in rural residents in Japan. Data suggest that bone resorption was extremely stimulated in the residents in China and that fluoride may stimulate both bone resorption and bone formation. Because indoor fluoride from combustion of coal is easily absorbed in stored food and because food consumption is a main source of fluoride exposure, it is necessary to reduce airborne fluoride and food contamination to prevent serious fluorosis in China.

Indoleamine metabolism in the pineal gland of the Chinese hamster, Cricetulus griseus

Day- and nighttime contents of pineal melatonin and other indoleamines were measured in the Chinese hamster, Cricetulus griseus. The hamsters were inbred in our colony and kept in LD 14:10. Absolute levels of pineal melatonin and N-acetylserotonin contents were extremely low, but showed a significant circadian rhythm with a minor peak during the light period. Pineal hydroxytryptophan and serotonin (5HT) contents were also found to be higher in the light period. The activity of N-acetyltransferase in the pineal was higher in the light period than in the dark period, whereas there was no difference in hydroxyindole-O-methyltransferase activity between the light and dark periods. The uptake level of tryptophan into the pineal gland was higher in the light period than in the dark period. These results suggest that the 5HT synthesis pathway and/or tryptophan uptake may be involved in forming the circadian rhythm of 5HT content in the Chinese hamster pineal gland.

Quantitative light microscopic study on the heterogeneity in the superficial pineal gland of the rat

BACKGROUND

The previous results regarding regional and day-night differences in pinealocyte size in rats are conflicting. The relationships between these differences and the vascularity and sympathetic innervation have scarcely been investigated.

METHODS

Wistar-King rats, kept under light/dark 12:12, were killed at midday or midnight in October. The nuclear density of pinealocytes in the superficial pineal was measured on the dorsoperipheral, dorsocentral, ventroperipheral, and ventrocentral regions at distal, middle, and proximal levels at daytime and nighttime. The total area of blood vessels per unit area at daytime and nighttime and total length of tyrosine hydroxylase (TH)-immunoreactive fibers per unit area at daytime were determined on the same regions at the same levels.

RESULTS

Pinealocyte size was larger toward the distal levels and in the periphery than in the center at any level. The area of blood vessels and length of TH fibers were also larger toward the distal levels; the former in the ventral region and the latter in the dorsal and ventral regions were larger in the periphery than in the center. Ventral pinealocytes, but not dorsal ones, showed day-night changes in size. Prominent day-night rhythms in area of blood vessels occurred in the ventral region, where TH fibers were more abundant than in the dorsal region.

CONCLUSIONS

Pinealocyte size shows the distal to proximal and peripheral to central gradients, which may be related to the differential distribution of blood vessels and sympathetic fibers. Since pinealocytes and blood vessels, showing prominent day-night changes in size, are localized in the more richly innervated regions, sympathetic fibers may play an important role in controlling these rhythms.

Non-functional role of syntaxin 2 in insulin exocytosis by pancreatic beta cells

This study was designed in order to examine the expression and functional role of syntaxin 2/epimorphin in pancreatic beta cells. Northern blot analysis revealed that syntaxin 2 mRNA was able to be detected in mouse beta TC3 cells, but not in isolated mouse islets. In agreement with this result, immunoblot analysis detected an appreciable amount of syntaxin 2 protein in beta TC3 cells, but not in mouse islets. Immunohistochemistry of the mouse pancreas demonstrated that syntaxin 2 was little evident in islet cells of Langerhans, and somewhat predominant in exocrine tissues. In order to examine whether syntaxin 2 is anchored to cell surfaces in beta TC3 cells, living cells were incubated with a monoclonal antibody against syntaxin 2 (MC-1). The antibody bound to their surfaces, indicating that syntaxin 2 was localized on cell surfaces. The addition of MC-1 to the culture medium of beta TC3 cells did not affect insulin release under the presence or absence of 11 mM glucose, indicating that syntaxin 2 is not associated with insulin exocytosis. Thus, the expression of syntaxin 2 in islets of Langerhans is very low and the function of this protein is probably unrelated to the insulin exocytosis pathway.

Low level c-myc gene amplification in gastric cancer detected by dual color fluorescence in situ hybridization analysis

BACKGROUND AND OBJECTIVES

By using the dual color fluorescence in situ hybridization analysis, the amplification of c-myc gene can be detected in the tumor tissue samples obtained from patients with gastric cancer, and the relationship between the molecular cytogenetic change and the clinical stage or histological type may be clarified.

METHOD

The tumor tissue samples were obtained from 21 patients with gastric cancer. Simultaneous detection of signals from the chromosome 8 centromere and c-myc gene in each cell after hybridization with appropriate probes was carried out on 50-200 tumor cells in each case.

RESULTS

Chromosome 8 polysomy was found in 10 patients. The average centromere 8 copy number was significantly higher in differentiated (2.7) than in undifferentiated (2.3) types of gastric cancer. However, there was no significant difference in occurrence of polysomy 8 between early and advanced cancer. The relative gain (1.1-1.9) of c-myc copy number was found in all 21 cases. There was no significant difference in the fraction of cells with c-myc gene amplification between early (pT1) and advanced (pT2-4) carcinomas.

CONCLUSION

We conclude that the present dual color fluorescence in situ hybridization of gastric cancer may be useful in the evaluation of low level c-myc gene amplification, which is difficult to detect by Southern blotting, and may be applicable to the diagnosis of early gastric cancer.

Propiverine hydrochloride, an anti-pollakiuric agent, inhibits the activity of actomyosin ATPase from the urinary bladder

The present study was performed to investigate the effects of propiverine hydrochloride (1-methyl-4-piperidyl diphenylpropoxyacetate hydrochloride, P-4), a novel anti-pollakiuric agent, on the contractile proteins of smooth muscle. P-4 (30-300 microM) inhibited the activity of native actomyosin adenosine triphosphatase (ATPase) that had been freshly purified from canine urinary bladder, and calmodulin at 10 microM overcame this inhibition. P-4 also inhibited myosin light chain kinase from smooth muscle in a dose-dependent manner. However, at 300 microM, P-4 was unable to inhibit by 50% the activity of trypsin-treated myosin light chain kinase, which was independent of Ca2+/calmodulin. 1 mol of calmodulin bound 4 to 5 mol of [14C]P-4 in a Ca2+-dependent manner with a K(d) of 77.4 microM. These results indicate that calmodulin is one of the intracellular target molecules for P-4 and that inhibition of the action of calmodulin by P-4 might cause the inhibition of actomyosin ATPase activity, with subsequent relaxation of the smooth muscle of the urinary bladder.

Effect of an endothelin-1 antagonist, BQ-485, on cerebral oxygen metabolism after complete global cerebral ischemia in dogs

Endothelin-1 (ET-1) plays an important role in the physiologic or pathophysiologic regulation of cerebral circulation. To evaluate the effects of the newly synthesized ETA receptor-selective antagonist, BQ-485 (N-perhydroazepin-l-ylcarbonyl-Leu-D-Trp-D-Trp-OH), on the cerebral metabolism of oxygen during the delayed cerebral hypoperfusion that follows global cerebral ischemia, we occluded the ascending aorta and caval veins of 10 beagle dogs for 12.5 min. The animals were randomized into two groups. BQ-485 was given directly into the carotid artery at 0.03 mg/kg per min for 30 min, starting 15 min after reperfusion in the treatment group (n = 5). Isotonic saline was infused in the control group (n = 5). A fiberoptic catheter was inserted into the superior sagittal sinus to monitor its oxygen saturation (SssO2) continuously. Arterial O2 content (CaO2), and sagittal sinus O2 content (CssO2) were monitored before and at 0.5, 1, 2, 4, 6 and 8 h after the ischemic insult. BQ-485 significantly prevented the expected decrease in SssO2 and increase in the cerebral O2 utilization coefficient at 4, 6 and 8 h after the ischemic insult (P < 0.05). Thus, BQ-485 ameliorated the mismatch between O2 supply and demand in the delayed hypoperfusion phase. We conclude that ET may be involved in the pathogenesis of delayed cerebral hypoperfusion after cardiac arrest.

Differentiation and morphogenesis in pellet cultures of developing rat retinal cells

We previously developed a reaggregate cell culture system (pellet cultures) in which retinal neuroepithelial cells proliferate and give rise to rod photoreceptor cells (rods) in vitro (Watanabe and Raff, 1990, Neuron 4:461-467). In the present study, we analyzed cell differentiation and morphogenesis in pellet cultures by using both cell-type-specific markers with immunofluorescence and electron microscopy. We demonstrated that, in addition to rods, the other major retinal cell types, including amacrine cells, bipolar cells, Müller cells, and ganglion cells were all present in the pellets, where most were able to develop from dividing precursor cells in vitro. The different cell types in the pellets became organized into two distinct structures: dark rosettes and pale rosettes. The cellular composition of these structures indicated that the dark rosettes correspond to the outer nuclear layer and the pale rosettes to the inner nuclear layer of the normal retina. Ultrastructural studies have indicated that the thin layer of neuronal processes surrounding the dark rosettes correspond to the outer plexiform layer, and the central region of the pale rosettes correspond to the inner plexiform layer of the normal retina. Other features of normal retinal development also occurred in the pellets, including programmed cell death and the formation of inner and outer rod cell segments and synapses. Thus, pellet cultures provide a convenient way to study different aspects of retinal development where one can control the size and the cellular composition of the initial reaggregate.

QM is a novel zinc-binding transcription regulatory protein: its binding to c-Jun is regulated by zinc ions and phosphorylation by protein kinase C

A novel method was developed for cloning of zinc-binding proteins. We used 65Zn2+ as a probe to screen a human lung cDNA library, and isolated QM using this approach. QM appears to be a negative regulator of c-Jun that acts by binding to the leucine zipper region of c-Jun. We demonstrated that QM bound zinc ions and that such binding was necessary for the interaction of QM with c-Jun. We also showed that protein kinase C introduced about 1 mol of phosphate into 1 mol of QM. The binding of QM to c-Jun was decreased by 60% when QM had been phosphorylated. These results suggest that QM is a novel zinc-binding transcription regulatory protein and that interaction between QM and c-Jun is regulated by zinc ions and phosphorylation.

[Quantitative evaluation of magnetization transfer ratio in irradiated breast with breast conservation therapy]

To assess the late effects of radiotherapy, magnetization transfer was evaluated in 2 patients with breast conservation treatment and in 4 patients without treatment. The magnetization transfer ratios (MTRs) were measured from a pair of images obtained by the conventional SPGR pulse sequence and the MT-prepared SPGR sequence on a 1.5-TMR system. The MTR values of irradiated breast were higher than those of non-irradiated breast. The difference in MTR between them was considered to represent tissue change due to irradiation. We showed that MTR is a useful parameter in estimating the late effects of radiotherapy.

Narrow photon beam dosimetry for linear accelerator radiosurgery

The dosimetric characteristics of linear accelerator radiosurgery for 10-MV X-ray were measured. Measurement of the relative output factor and tissue maximum ratio with a microchamber produced results equivalent to those of measurement with X-ray film. The 80% isodose level width measured with the microchamber was significantly smaller than that measured with the X-ray film. For the measurement of relative output factor and tissue maximum ratio, a microchamber seems to be the more appropriate choice. X-Ray film was found to be suitable for beam profile measurement.

Development of a potassium-specific adsorbent for direct hemoperfusion

Direct hemoperfusion (DHP) over an exchange resin for sodium is capable of rapidly lowering an elevated serum potassium level but has not been used clinically because of subsequent electrolyte abnormalities. After the completion of detailed in vitro studies, we developed a sodium/calcium/magnesium exchange resin mixture specifically to remove potassium from the blood. The mixture, which consisted of exchange resins for sodium (48%), calcium (48%), and magnesium (4%), gave the most satisfactory results in vitro. DHP through these resin-mixture columns for 2 h reduced elevated plasma potassium levels (6.7 +/- 1.1 to 3.5 +/- 0.6 mEq/L, p < 0.001) in anephric dogs without including any significant change in the levels of sodium, calcium, magnesium, albumin, total protein, or cholesterol. The platelet losses and changes in the plasma free hemoglobin levels observed were similar to those found with activated charcoal hemoperfusion. These results suggest that this resin hemoperfusion may be useful in patients with acute hyperkalemia.

[Analysis of risk factors for development of bronchopleural fistula after pneumonectomy for lung cancer]

Bronchopleural fistulas (BPF) developed in six (7.9%) of 76 patients who underwent a pneumonectomy for treatment of lung cancer. Five patients (18.2%) underwent a right pneumonectomy and one (3.7%) a left pneumonectomy. All patients were male, had squamous cell carcinoma, and were diagnosed as having BPF within one month after pneumonectomy. Their average age was 60.2 years. Univariate analyses related to development of BPF showed that significant risk factors were preoperative infection (Chi-square test; p < 0.001), right pneumonectomy (Chi-square test; p < 0.05), and metastasis to a subcarinal lymph node (Chi-square test; p < 0.05). However, sex, age, operating time, amount of blood loss during surgery, amount of blood transfused during surgery, history of smoking, degree of lymph node dissection, degree of curability, performance of combined resection, histologic type of tumor, tumor size, presence of residual tumor at the bronchial stump, and suturing method were not significant risk factors for development of BPF. Our stepwise regression analysis related to development of BPF showed that preoperative infection, metastasis to a subcarinal lymph node, right pneumonectomy, and combined resection were significant risk factors. Sometimes it is difficult to preserve the bronchial arteries upon the dissection of metastatic subcarinal lymph nodes which tightly adhere to the bronchial sheath. Moreover, after a conventional right pneumonectomy, the bronchial stump protrudes into the pleural cavity and is not covered by any tissue. Ligation of the bronchial arteries or protrusion of the bronchial stump into the right pleural cavity reduces the blood supply to the bronchial stump to a very low level and causes development of BPF. Therefore, we suggest that control of preoperative infection, wrapping of the bronchial stump, and preservation of the bronchial arteries during mediastinal lymph node dissection are important to prevent development of BPF.

[Quantification of brain metabolites by 1H spectroscopy using cyclohexane as an external reference]

We tested the reliability of quantifying brain metabolite concentrations by MR spectroscopy. We employed a PRESS sequence and used a cyclohexane sample as an external standard. The signal intensity ratios of water and cyclohexane were measured by changing the geometrical arrangement of the cyclohexane sample and water phantom with various loading factors of the coil. Choline (Cho) concentrations were calculated from the signal intensity ratios of Cho and water and compared with actual Cho concentrations (1.0 to 2.6 mmol/L). The brain metabolites Cho, creatine/phosphocreatine (Cr/PCr) and N-acetylaspartate (NAA) were evaluated in five normal volunteers and six patients with metastatic brain cancer before (0 Gy), after 20 Gy and after 40 Gy of whole brain radiotherapy. Variation in the ratio of spectrum intensity between water and cyclohexane was less than 1.5% for various geometrical arrangements and loading factors. The error in quantification of Cho concentrations in the phantom study was 0.05 +/- 0.10 mmol/L. The concentrations measured in the volunteers were: Cho 1.6 +/- 0.4 mmol/L, Cr/PCr 6.4 +/- 1.1 mmol/L and NAA 8.2 +/- 0.1 mmol/L. There was no significant difference (p > 0.05) in these concentrations between the control group and the patients before, during, or after radiotherapy.

Localization and ontogeny of GLUT3 expression in the rat retina

This study investigates the presence, localization, and developmental expression of a neuron-specific facilitated-diffusion glucose transporter, GLUT3, in the rat retina so as to elucidate molecular mechanisms regulating glucose homeostasis in support of the visual function. Immunoblot analysis using anti-GLUT3 antibody (ALM3-C) revealed the presence of GLUT3 as a heterogeneously glycosylated protein with an average molecular weight of approximately 44 kDa. Although immunofluorescence staining showed it to be localized primarily in the inner and outer plexiform layers, some of the cell bodies in the inner nuclear layer also showed weak immunoreactivity. Immunoblot analysis of developing rat retinal tissues revealed the presence of the GLUT3 protein as early as embryonic day 15 (E15), and immunofluorescence staining revealed its expression in the inner plexiform layer near the time of birth and in the outer plexiform layer at postnatal day 14 (P14), i.e., when the eyes normally open and retinal activity commences. The protein's abundance remained at a relatively low level during the embryonic stages and up until the end of the first postnatal week (P7), though a transient increase was confirmed to occur at E18. From P13, however, the abundance steadily increased, rapidly reaching the adult level at P24. Based on these observations, we hypothesize that GLUT3 is expressed in some subsets of retinal neurons, being preferentially abundant in their neuronal processes, and that its ontogeny is closely associated with morphological and functional development of the retina. As such, this suggests that GLUT3 plays some important role(s) in the retina where glucose metabolism is essential.

[A fulminating case of Edwardsiella tarda septicemia with necrotizing fasciitis]

A 67-year-old Japanese male, suffering from liver cirrhosis with hepatoma, was admitted to the Yokohama National Hospital because of ascites retention. On physical examination, his abdomen was massively distended with ascites and his lower extremities were edematous. Laboratory findings on admission revealed hypoalbuminemia, moderate icterus, pancytopenia and hepatitis C virus antibody positivity. After admission, abdominal distention and edema were improved with the use of diuretics. On the 15th day of hospitalization, the patient noted diarrhea and bowel movements that occurred 10 times a day. On the following day, his body temperature rose to over 39 degrees C. On the morning of the 17th day, he complained of severe pain in the right lower extremity. Swelling and erythema over his right lower leg were evident. The skin lesion spread rapidly over the knee and became necrotic. His right leg became increasingly swollen with the development of edema and hemorrhagic bullae. About 4 hrs after the emergence of the skin lesion, his blood pressure fell to less than 60 mmHg. Laboratory findings suggested disseminated intravascular coagulation and multiple organ failure due to serious bacterial infection. In spite of vigorous treatment including administration of antibiotics, dopamine, gabexate mesilate and plasma, he did not recover from the state of shock and died about 14 hrs after the appearance of leg pain. Bacterial culture of the blood and contents of the bullae grew a gram negative rod identified as Edwardsiella tarda (E. tarda). Histological findings showed necrotizing fasciitis. E. tarda has recently become recognized as a pathogenic bacteria, particularly in patients with an underlying illness. This is the first reported case of E. tarda septicemia with necrotizing fasciitis.

Regional differences in the pineal gland of the cotton rat, Sigmodon hispidus: light microscopic, electron microscopic, and immunohistochemical observations

Light microscopic, electron microscopic and immunohistochemical observations of the various portions of the pineal gland of the cotton rat (Sigmodon hispidus) were made. The volume of the proximal half occupied about 30% of the whole organ, and pinealocytes were slightly smaller in size in the proximal portion than elsewhere. The distal and intermediate portions contained few interstitial cells and numerous astrocytes, but the proximal portion lacked interstitial cells and had more abundant astrocytes than elsewhere. Astrocytes, which were immunoreactive for glial fibrillary acidic protein, mainly lined the pericapillary spaces in the distal and intermediate portions, but in the proximal portion these cells often surrounded isolated or groups of pinealocytes. In the distal and intermediate portions, abundant sympathetic fibers and less numerous non-sympathetic, peptidergic fibers were mainly localized in the pericapillary spaces; these fibers were sparsely distributed in the parenchyma close to interstitial cells or astrocytes. In the proximal portion, non-sympathetic fibers were scarce and sympathetic fibers were distributed abundantly and almost exclusively in the parenchyma. Most of the sympathetic fibers were adjacent to astrocytes and, occasionally, made specialized contact with them. Fenestrae in the capillary endothelium were numerous in the distal portion but absent in the proximal portion. Thus, marked differences in structure existed between the distal and proximal portions of the pineal gland of the cotton rat suggesting that both portions are functionally dissimilar. In addition, the present study indicates that the proximal portion of the cotton rat was well developed and showed morphological features similar to the deeply situated pineal glands of other mammals.

[Evaluation of the prognosis of patients with stage I non-small cell lung cancer with respect to predicted postoperative lung function]

One hundred and forty patients underwent absolute curative resction for stage I non-small lung cancer from 1982 to 1993 at our department. For these, prognosis and changes in quality of life (QOL) were evaluated retrospectively with respect to the predicted postoperative lung function. The average age of the patients was 62 years (range 31 to 84 years), and 103 males and 37 females were included. Seventy-five of the patients had adenocarcinoma, 61 squamous cell carcinoma, and 4 large cell carcinoma. These 140 patients were classified into two groups, H and N, according to the predicted postoperative %FEV1.0 and %VC. Group H patients (n = 39) had a predicted %FEV1.0 and/or %VC of 55% or less for postoperative respiratory disease. Group N patients (n = 101) had a predicted %FEV1.0 and %VC of 56% or more for expected normal respiratory conditions postoperatively. Group N patients showed a 98% one-year survival rate, and 72% five-year survival rate and good QOL postoperatively. On the other hand, group H patients showed 86% and 45% one- and five-year survival rates respectively, the same as those predicted for patients with stage II non-small cell lung cancer. Furthermore, group H patients more than 70 years old showed 80% and 17% one- and five-year survival rates, the same as those predicted for patients with stage IIIA non-small cell lung cancer, and poor prognosis in comparison with that of the group N patients more than 70 years old. Then, QOL was investigated one year postoperatively. The group H patients showed deterioration of performance status in comparison with the group N patients. Since there was a high incidence of postoperative respiratory disease in the patients with a predicted %FEV1.0 and/or %VC of 55% or less, physicians should avoid extended lung resection, which might cause deterioration of the cardiopulmonary reserve volume, in patients in whom respiratory disease is predicted to occur, particularly for patients more than 70 years old. In conclusion, physicians should consider limiting surgical intervention to preserve lung volume and QOL of patients more than 70 years old with restricted cardiopulmonary function.

Simultaneous determination of serotonin, N-acetylserotonin and melatonin in the pineal gland of the juvenile golden hamster by high-performance liquid chromatography with electrochemical detection

A simple and simultaneous determination of melatonin and its precursors, serotonin (5-HT) and N-acetylserotonin, was achieved by reversed-phase high-performance liquid chromatography with electrochemical detection. The addition of an ion-pairing agent, sodium 1-octanesulfonate, to the chromatographic mobile phase caused an increase of the retention time of 5-HT, and resulted in the successful simultaneous resolution of these three indoleamines. This method was used to quantitate these indoleamines in the pineal gland of juvenile golden hamsters.

Sprouting of non-sympathetic myelinated and unmyelinated fibres in response to chronic sympathetic denervation in the pineal gland of the Chinese hamster, Cricetulus griseus

We have examined the effects of chronic sympathetic denervation on non-sympathetic myelinated and unmyelinated fibres in the superficial pineal gland of the Chinese hamster (Cricetulus griseus), using LM, EM and immunohistochemistry. The results suggest that non-sympathetic, myelinated and unmyelinated fibres enter the superficial pineal gland at its distal portion by way of the nervi conarii, and that these fibres are immunoreactive for calcitonin gene-related peptide or substance P. Non-sympathetic, myelinated and unmyelinated fibres in the superficial pineal gland increased in number following chronic superior cervical ganglionectomy. The number of unmyelinated fibres in the nervi conarii also increased in ganglionectomized animals. Thus, the numerical increase of calcitonin gene-related peptide or substance P fibres found in the superficial pineal gland after long-term sympathectomy may be due to sprouting of these fibres. It is speculated that the growth of non-sympathetic, myelinated and unmyelinated fibres and myelination of the former fibres occurring after sympathectomy are caused by nerve growth factor-related mechanisms.

Effects of mild Trendelenburg on central hemodynamics and internal jugular vein velocity, cross-sectional area, and flow

Despite widespread use of the Trendelenburg position, its autotransfusion effect remains controversial. Additionally, its adverse effect on cerebral circulation is not generally appreciated. The effects of a 10 degrees head-down tilt on central hemodynamics and flow through the internal jugular vein (IJV) were examined in ten healthy volunteers. Left ventricular end-diastolic volume (LVEDV) and cardiac output (CO) were calculated from two-dimensional echocardiograms. IJV velocity and cross-sectional area were determined by the pulsed Doppler system. Measurements were made with the subjects in the supine position and at 1 minute and 10 minutes after tilting. A significant increase (16%) in CO followed by the increase in LVEDV was observed at 1 minute after tilting, although these changes disappeared after 10 minutes of tilting. Mean arterial pressure at the heart level did not change during the maneuver. The IJV velocity decreased whereas the IJV cross-sectional area increased at 1 minute after tilting, but both factors returned to control level at 10 minutes after tilting. As a result, calculated IJV blood flow was unchanged throughout the period of tilt. Therefore, the mild trendelenburg position produces a transient autotransfusion effect in normovolemic patients. Our data also suggest that the Trendelenburg produces no adverse effect on cerebral circulation in patients with normal cerebral autoregulation.