[Flow cytometric analysis of DNA ploidy in intramucosal gastric carcinoma]

In order to investigate whether or not DNA ploidy was altered in intramucosal gastric carcinomas, nuclear DNA content of biopsy specimen was measured using flow cytometry in 38 intramucosal carcinomas. DNA aneuploidy was detected in 27 of 38 lesions (71.1%), and noted more frequently in differentiated carcinomas than in undifferentiated ones (83.0% vs. 20.0%, p < 0.01). There was no significant relationship between the frequency of DNA aneuploidy and macroscopical type or tumor size. DNA aneuploidy was even found in two of three minute carcinomas (5 mm or less in diameter). DNA indices showed 1.2 or lower values in 40% of the lesions with DNA aneuploidy. The average value of DNA index was significantly larger in depressed type than in elevated type (p < 0.01). In conclusion, DNA ploidy is altered in most differentiated intramucosal carcinomas. A high resolution method is essential for accurate determination of DNA ploidy in intramucosal carcinomas, especially elevated ones.

[Flow cytometric DNA analysis of colorectal carcinoma in adenoma]

We evaluated the DNA ploidy in 23 lesions of colorectal carcinoma in adenoma (CIA) and 90 adenomas without carcinomas by flow cytometry using fresh samples. DNA ploidy of carcinoma and adenoma components were assessed, respectively, with 17 paraffin-embedded samples of CIAs. The incidence of DNA aneuploidy (AP) was significantly higher in CIAs than in adenomas (47.8% vs. 12.2%, p < 0.01). Even in adenoma components of CIAs, AP tended to be found more frequent than in adenomas (41.2% vs. 12.2%). The incidence of AP in adenoma components was similar to that in carcinoma components (35.3%) in CIAs. In conclusion, DNA aneuploidy in adenomas may be a marker of malignant potential.

[MultiCycle software for cell cycle analyses]

MultiCycle software (M-cycle), a computer cell cycle analysis program that has a background debris and aggregation compensating function, was utilized in this study to prove the usefulness of the M-cycle. The S phase fraction (SPF) calculated by the M-cycle was compared to that of bromodeoxyuridine labelling index (BLI) using colorectal carcinoma cell lines. The SPF value was slightly lower using the M-cycle than that of the BLI in Colo 201 and Colo 320 and lower significantly in Widr. This may indicate that the M-cycle effectively compensated for the background existing in the DNA histogram. The SPF value was computed both by the M-cycle and the sum of broadened rectangles model (SOBR). The SPF value of these cell lines showed a lower figure in the M-cycle than in the SOBR. The SPF value of paraffin-embedded material through the M-cycle and the SOBR was compared according to DNA ploidy patterns. The SPF value computed by the M-cycle was significantly lower in both ploidy patterns than that of the SOBR. In conclusion, the M-cycle is a useful tool for cell cycle analyses of simple DNA flow cytometric histograms obtained by paraffin-embedded material.

Arteriovenous differences in PCO2 and cardiac output during CPR in the dog

Using 14 mongrel dogs, we investigated the correlation between arteriovenous differences of PCO2 (AVD-CO2) and cardiac output (CO) during CPR. Ventricular fibrillation was induced by an electrical current and the respirator was stopped for 5 min. Cardiopulmonary resuscitation (CPR) was performed during the next 10 min and CO was measured with simultaneous arterial and venous blood gas analysis. CO was measured 26 times during CPR. The animals were divided into two groups according to the values of CO during CPR: low-CO group (CO < 0.3 l/min) and high-CO group (CO > or = 0.3 l/min). AVD-CO2 in the low CO group was 39.8 +/- 5.7 mmHg and that of the high group was 27.4 +/- 14.8 mmHg (mean +/- S.D., P < 0.05). In conclusion, AVD-CO2 showed an inverse result with the degree of CO during CPR.

Clinical usefulness of an assay for hepatitis C virus core in the diagnosis of non-A, non-B hepatitis and monitoring of the response to interferon therapy

The clinical utility of a new JCC-2 enzyme-linked immunosorbent assay kit that detects and quantitates anti-hepatitis C virus (anti-HCV) core antibodies (anti-HCc) was investigated. Serum samples were obtained from 102 patients with various non-A, non-B liver diseases, including 19 cases of chronic hepatitis type C who had been treated with interferon (IFN). The results of the anti-JCC-2 assay were significantly correlated with serum HCV-RNA positivity. Patients who were HCV-RNA positive exhibited a high rate of positivity for anti-JCC-2 (72.2% in acute hepatitis, > 90% in chronic liver diseases). The geometric mean of the anti-JCC-2 titre was not significantly different among different stages of chronic liver disease (among CPH, CAH and LC). The anti-JCC-2 titre decreased gradually in cases that became HCV-RNA negative after IFN therapy. If HCV-RNA positivity recurred, the anti-JCC-2 titre increased, indicating that serial measurements of the anti-JCC-2 titre are useful for monitoring the antiviral effect of IFN treatment. These results suggest that quantification of anti-HCc by the anti-JCC-2 assay is superior to the semi-quantification of circulating HCV-RNA provided by monitoring of IFN therapy. Monitoring of HCV-RNA status using reverse transcription-nested polymerase chain reaction (RT-nested PCR) is possible, but it is technically demanding and too expensive for routine clinical use.

A novel mutation in Cu/Zn superoxide dismutase gene in Japanese familial amyotrophic lateral sclerosis

Recently, several missense mutations in the Cu/Zn superoxide dismutase gene (SOD1) have been reported as a putative cause of chromosome-21q-linked familial amyotrophic lateral sclerosis (FALS). We have discovered a novel missense mutation (substitution of Thr for Ala4) in exon 1 (GCC to ACC) in two FALS patients from one Japanese FALS family. No mutations were found in 17 cases of sporadic ALS. The enzyme activity of recombinant fusion protein containing the Cu/Zn superoxide dismutase (SOD) with the Ala4-to-Thr mutation was significantly reduced in E. coli. On the other hand, in the expression system in insect cells using Baculovirus, the mutant SOD expressed an enzyme activity as high as wild-type SOD. These results suggest that the stability of SOD with the Ala4-to-Thr mutation is disrupted especially in the fusion protein. Autopsy was carried out on one of the two patients, and the pathological findings were typical of FALS with posterior column involvement. These results raise the possibility that mutation of the SOD1 is responsible for FALS with broader pathological involvement.

Horizontal condylar path in patients with disk displacement with reduction

In 32 patients with disk displacement with reduction, the condylar path in the horizontal plane during opening and closing movements of the mandible were analyzed with a computerized axiograph. The horizontal condylar tracings during opening were divided into 15 types. There was no clear relationship between the types and clinical symptoms. The specific correspondence of the types were revealed between the right and left joint. In 21 of 32 patients, the condyle on one side deviated medially, while the contralateral condyle deviated laterally at maximum opening. In most of the patients showing medio-lateral condylar deviation at maximum opening, a straight condylar path was observed from the maximum opening to the position just before the closing click. In some of the patients, the type of horizontal condylar tracing during opening was related to the displacement pattern of the disk assessed by magnetic resonance imaging (MRI).

Expression of cytokines, TNF-alpha and IL-1 alpha, in MAM acetate and 1-hydroxyanthraquinone-induced colon carcinogenesis of rats

The expression of cytokines, TNF-alpha and IL-1 alpha, was examined by means of a reverse transcription followed by PCR (RT-PCR) in rat colon carcinogenesis. Forty male F344 rats were used and divided into four groups. At the start of the experiment, 20 rats were treated with methylazoxymethanol (MAM) acetate (25 mg/kg body wt, one time, i.p.) and divided into two groups; group 1 was exposed to 1% 1-hydroxyanthraquinone (1-HAQ) and group 2 was fed a basal diet during the experiment (40 weeks). Other rats were also divided into two groups; group 3 was exposed to 1% 1-HAQ as group 1, and group 4 was used as control. Tumor incidence (100%) and multiplicity (5.00 +/- 2.05) in group 1 were significantly greater than those in group 2 (20% and 0.2 +/- 0.42) and group 3 (10% and 0.10 +/- 0.32) (P < 0.01 and P < 0.01 respectively). RT-PCR technique with RNA was applied to the tissues from colon neoplasms and mucosa in each group. Expression of TNF-alpha and IL-1 alpha in the colon neoplasms was much stronger than that in the colon mucosa of each group (P < 0.001 and P < 0.01 respectively). The expression of TNF-alpha was more remarkable in the colon mucosa of group 1 than that in corresponding tissue of groups 2 and 3 (P < 0.01). The expressions of TNF-alpha and IL-1 alpha were more increased in the colon mucosa of groups 1, 2 and 3 than that in group 4 as control (P < 0.01 and P < 0.05 respectively). The results indicate that TNF-alpha and IL-1 alpha may act as growth factors in rat colon carcinogenesis by MAM acetate and 1-HAQ. In addition, the synergistic effect of 1-HAQ with MAM acetate in colon carcinogenesis might be related to biological effects of the cytokines expressed in the inflammatory condition generated by 1-HAQ.

A case of fibrous histiocytoma associated with xanthogranulomatous alteration

We report here an unusual case of fibrous histiocytoma in which an area of xanthogranuloma was observed histologically. Our case suggests that adult xanthogranuloma is a variant of fibrous histiocytoma.

Antiphospholipid antibodies. A prognostic factor in sarcoidosis?

Serum antibodies against five types of phospholipids, antiphospholipid antibodies (aPL), were determined by an enzyme-linked immunosorbent assay in 55 patients with sarcoidosis. Either IgG or IgM aPL were detected in 21 patients (38 percent). This positive rate was significantly higher than that (7 percent) of healthy control subjects (p < 0.001). In terms of immunoglobulin classes, 5 cases had IgG aPL only, 11 cases had IgM aPL only, and 5 cases had both classes of aPL. No correlation was observed between the occurrence of aPL and disease activity of sarcoidosis. A significant correlation was noted between the occurrence of aPL and many extrathoracic organ lesions or the persistence of abnormal chest x-ray film findings for periods of 2 and 5 years. Taken together, the presence of aPL in sarcoidosis is a useful index to judge the prolongation of the disease.

MRI and MRS studies on acute effects of ethanol in the rat brain

Magnetic resonance imaging and spectroscopy (MRI and MRS) were used to examine the effects of intoxicating doses of ethanol on the rat brain. 1H-MR images were obtained using three different methods: (1) PD weighted images, (2) T1 weighted images and (3) T2 weighted images. T1 and T2 relaxation times of the tissues were calculated by pixel-to-pixel image computation. After ethanol treatment, the cerebral hemispheres showed high signal intensities in the T1 weighted images, whereas low signal intensities were observed in the T2 weighted images, markedly in the cortex. At 4 h, the T1 values significantly decreased in the thalamus and the hypothalamus of the ethanol treated rats compared with those of the animals under pentobarbital anesthesia. At 1 h, the T2 values significantly decreased in the cortex of the ethanol treated rats. At 4 and 24 h, the T2 values significantly decreased throughout the cerebral hemispheres in the ethanol treated rats. The in vivo 31P-MRS results showed that after ethanol treatment, ATP and phosphocreatine slightly decreased, but not to a great degree. Intracellular pH levels, determined using the values of the chemical shift in inorganic phosphate peaks, decreased and returned to normal by 4 h. In the highly sedated animals, the acidosis observed early on was followed by heavy alkalosis. In in vitro 1H-MR spectra of brain and blood extract samples, many kinds of metabolites were assigned. The quantitative results were as follows: (1) Blood and brain ethanol levels rose to a peak at 1 h after ethanol treatment and no ethanol was detected at 24 h in any samples. (2) Blood acetate levels increased significantly, and returned to the control level by 24 h, whereas the brain acetate levels were largely unchanged. (3) Blood lactate levels decreased significantly at 0.5 h and brain lactate levels mildly increased and rose to a peak at 2 h. (4) Brain N-acetylaspartic acid (NAA) increased at 0.5 h significantly and decreased significantly at 4 h. Electron microscopic findings were as follows: (1) Both neuronal and glial cells were edematous after ethanol treatment. (2) Congestion was serious in all the regions we observed, and it was still present 24 h after ethanol treatment. (3) Swelling of mitochondria was observed in capillary endothelial cells. Our results suggest that high doses of ethanol cause circulatory disorders in the rat brain and disturb the water balance in the cerebral tissues, changing the structures of intracellular water molecules. It also causes metabolic confusion without depletion of high energy phosphate metabolites.

Left ventricular mass and subsequent blood pressure changes among middle-aged men in rural and urban Japanese populations

BACKGROUND

It has been suggested that echocardiographically determined left ventricular mass (LVM) is useful in the prediction of hypertension. To examine the relation between LVM and subsequent blood pressure (BP) change, a 6- to 8-year follow-up was conducted in adult Japanese men.

METHODS AND RESULTS

LVM was determined by M-mode echocardiography using the American Society of Echocardiography formula among 354 normotensive men aged 30 to 59 years from a rural community (n = 193) and from urban companies (n = 161) in Japan between 1979 and 1983. BP was remeasured 6 to 8 years after baseline in 148 rural men (77%) and 127 urban men (79%). For men whose BP was remeasured, the mean +/- SD LVM index (LVM/body surface area [g/m2]) at baseline was 117 +/- 22 in rural men and 99 +/- 15 in urban men (the difference, P < .001). For both populations, LVM index was positively associated with age and physical activity but not with body mass index. Associations of LVM index with usual alcohol intake and initial BPs were generally weak. According to linear regression analyses after controlling for these covariates at baseline, a 20-g/m2 greater LVM index at baseline was associated with a 5 mm Hg increase in systolic and a 4 mm Hg increase in diastolic BP during the subsequent 6 to 8 years for urban men. A 1-mm greater average ventricular wall thickness was associated with a similar BP increase. For rural men, positive associations of LVM index with BP increase existed but were weak. The weaker association between LVM index and BP increase in rural compared with urban men was probably the result of effects of higher physical activity, leading to a larger left ventricular internal dimension. The increase in systolic and diastolic BPs over the 6 to 8 years of observation was significantly related to baseline LVM index in rural and urban men with a smaller internal dimension (rural men, < or = 49 mm; urban men, < or = 47 mm) but not in those with larger dimensions.

CONCLUSIONS

An increased LVM index predicts subsequent BP increase in middle-aged normotensive men in the presence of a normal or small internal dimension.

Horizontal transmission of Salmonella enteritidis and effect of stress on shedding in laying hens

Horizontal transmission of Salmonella enteritidis in laying hens and the short-term effect of stress on shedding were examined in 32 seven-month-old laying hens. Half were inoculated with 10(5) colony-forming units of S. enteritidis phage type 4, and the remaining half were left uninoculated to study horizontal transmission. Isolation of S. enteritidis from cecal droppings of all hens was attempted every morning. Uninoculated hens rapidly became infected through contaminated drinking water. Introduction of young chickens to the same rearing room and withdrawal of water and feed for 2 days coincided with a rapid increase in the shedding rate of S. enteritidis for a short period of time. The results showed that a short-term increase in the shedding rate of S. enteritidis is associated with short-term exposure to environmental stress.

[A case of Budd-Chiari syndrome treated by radical operation under hepatic perfusion and extracorporeal circulation]

A 41-year-old male patient of Budd-Chiari syndrome associated with membranous obstructions of the retrohepatic inferior vena cava and the left hepatic vein was reported. A radical operation was carried out. The retrohepatic inferior vena cava was reconstructed by a ringed EPTFE patch graft after endovenectomy with the aid of extracorporeal circulation for caval and portal bypasses utilizing cold hepatic perfusion. The patient has been doing well 18 months after the operation.

Involvement of a DNA binding protein, MDR-NF1/YB-1, in human MDR1 gene expression by actinomycin D

The human multidrug resistance 1 (MDR1) gene is an SOS gene that responds to environmental stress including various anticancer agents. The chloramphenicol acetyltransferase (CAT) gene was linked to various lengths of MDR1 promoter, and these constructs were integrated into the genome of human cancer KB cells. Using these cell lines, we previously demonstrated that various environmental stimuli lead to an increased abundance of both CAT enzymatic activity and CAT mRNA in a sequence dependent manner. We examined the molecular mechanism of this stress response using actinomycin D, a potent RNA synthesis inhibitor. We found that CAT activity was significantly increased more than 10 fold by actinomycin D itself without comparable elevation of CAT mRNA. CAT induction was, however, lost in the presence of a deletion from position -136 to -76. Gel mobility shift assays showed that the specific DNA binding activity of the transacting protein, MDR-NF1/YB-1, which binds to the inverted CCAAT box, was augmented in nuclear extracts from the cells treated with actinomycin D. We also found that actinomycin D increased the steady state levels of MDR-NF1/YB-1 mRNA, which encodes the inverted CCAAT box binding protein. These results indicate that MDR-NF1/YB-1 mediates the response of the MDR1 gene to environmental stress.

Effects of herbimycin A and its derivatives on growth and differentiation of Ph1-positive acute lymphoid leukemia cell lines

The molecular basis of the Philadelphia chromosome (Ph1) is a structurally altered c-abl (bcr/abl) gene which encodes an abnormally large protein with protein tyrosine kinase activity. Herbimycin A, an inhibitor of tyrosine kinase, preferentially inhibited the growth of Ph1-positive acute lymphoid leukemia (ALL) cell lines, as well as Ph1-positive chronic myeloid leukemia (CML) cell lines. Although noncytotoxic concentrations of herbimycin A induced erythroid differentiation of two CML-derived cell lines, K562 and KU812, in a previous study, the differentiation-inducing effect of herbimycin A on Ph1-positive ALL cell lines was less strong. Herbimycin A enhanced some differentiation-associated properties of one Ph1-positive ALL cell line, L2, but the effect of herbimycin A on the other Ph1-positive ALL cell lines was cytotoxic rather than cytostatic (differentiation-inducing). Several derivatives of herbimycin A were synthesized and their effects on the cell proliferation of Ph1-positive CML and ALL cell lines were examined. The sensitivities of the Ph1-positive cell lines to herbimycin A derivatives were different from the data on the rat kidney cell line infected with Rous sarcoma virus (v-src) derived from a previous study, suggesting bcr/abl kinase may differ in sensitivity from other tyrosine kinases. Moreover, the sensitivities of the ALL cell lines were not the same as those of the CML cell lines. These results suggest that a specific inhibitor of bcr/abl kinase could be an effective antileukemic agent against Ph1-positive CML or ALL.

Female predominance of extrathymic T cells in mice: statistical analysis

Female predominance of autoimmune diseases is widely known in humans and animals. To elucidate one of the underlying mechanisms, we examined whether sex differences exist at the level of extrathymic T cells in various organs of mice under physiological conditions. This attempt came from previous experimental results showing that estrogen administration to mice activates extrathymic T cells in the liver. Extrathymic T cells expressing TCR (and CD3) of intermediate intensity (i.e., intermediate TCR cells) and a high level of IL-2 receptor beta-chain (IL-2R beta), and thymus-derived T cells expressing TCR of bright intensity (i.e., bright TCR cells) and lacking IL-2R beta, were identified by immunofluorescent tests using mAbs. Three groups of different strains were examined. It was demonstrated that intermediate TCR cells were much more predominant in the liver and some other organs tested of female mice than of male mice, of each strain tested.

Correlation of p53 protein expression in human urothelial transitional cell cancers with malignant potential and patient survival

The p53 gene product has been detected frequently in various human malignancies. We have studied the expression of p53 protein in urothelial transitional cell cancers (TCCs) and examined its correlation with pathologic grade, stage(pT) and patient survival. Specimens from 69 surgically-resected TCCs (38 cases of urinary bladder cancer, 17 cases of ureteral cancer and 14 cases of renal pelvic cancer) were examined by immunohistochemical staining, using two anti-p53 monoclonal antibodies, PAb1801 and PAb240, and a polyclonal antibody, CM-1. Twenty-six TCCs (37.6%) were positively stained by at least one of the three antibodies. Statistical analysis showed a significant correlation between p53 expression and high pathologic grade (p < 0.05, p < 0.001) or progressive pathologic stage (p < 0.01). In addition, in 51 of the patients who were available for follow-up (23 cases of urinary bladder cancer, 13 cases of ureteral cancer, and 15 cases of renal pelvic cancer), the correlation between p53 protein expression and prognosis was examined. The survival of patients exhibiting positive p53 protein expression was significantly worse than those with p53-negative tumors (p < 0.05). These results suggest that an immunohistochemical test for p53 protein may be a useful method of evaluating the malignant potential of TCCs. Additionally, expression of p53 protein in TCCs is an indicator of a poor prognosis which should be considered in drawing up treatment strategies.

Antihistone antibodies in systemic sclerosis. Association with pulmonary fibrosis

OBJECTIVE

To determine the prevalence and clinical significance of antihistone antibodies (AHA) in systemic sclerosis (SSc).

METHODS

Serum samples from patients with limited cutaneous SSc (n = 44), diffuse cutaneous SSc (dcSSc; n = 48), and other SSc-related disorders (n = 22) were examined by enzyme-linked immunosorbent assay and immunoblotting for AHA.

RESULTS

AHA were demonstrated in 29% of the 92 SSc patients and in 44% of those with dcSSc. The presence of AHA correlated with severe pulmonary fibrosis in those with dcSSc. Immunoblotting revealed that the predominant antigen was histone H1.

CONCLUSION

AHA might be a serologic indicator of the severity of pulmonary fibrosis in SSc.

Bonhoeffer-van der Pol oscillator model of the sino-atrial node: a possible mechanism of heart rate regulation

A Bonhoeffer-van der Pol equation with a stable limit cycle is proposed as a model of the pacemaker in the sino-atrial node to explain heart rate regulation. Standard tools, such as the phase transition curve in nonlinear dynamic system theory, are used to analyze the model and results are compared with other studies on experiments with dogs.

Toe skin temperature as a guide to epidural anaesthesia dosing

To determine the time for additional epidural anaesthesia, skin temperature of the big toe was evaluated in 50 patients undergoing mastectomy. Epidural catheters were placed at or near the T5-6 intervertebral space and 12 ml, lidocaine 1.5% with 1:200,000 epinephrine were injected. When the skin temperature, which had increased following epidural anaesthesia, decreased by 0.3 degrees C without an increase of systolic arterial blood pressure (ABP) of more than 20%, 8 ml lidocaine 1.5% were injected. If the skin temperature increased, the monitor was judged to have been useful. When ABP increased > 20% without a decrease of skin temperature, the monitor was judged not to have been useful. Monitoring of toe skin temperature was useful in 39 patients (78%) in estimating the time for the first additional dose of epidural anaesthetic. First, second and third intervals between injection were 96.5 +/- 21.0 (n = 39), 69.7 +/- 14.2 (n = 35) and 50.1 +/- 12.2 min (n = 7), respectively. We conclude that, when epidural puncture is performed at upper thoracic levels, toe skin temperature can be a useful monitor to judge the time for additional anaesthetic.

Cortical magnetic and electric fields associated with voluntary finger movements

Multichannel recordings of both movement-related magnetic fields (MRMFs) and movement-related cortical potentials (MRCPs) were simultaneously recorded in association with voluntary unilateral self-paced index finger abduction movement in two normal volunteers. 1) Slow magnetic field (readiness field; RF) can be detected several hundred msec before the movement onset, and its field distribution indicates the existence of the largest generator source over the contralateral primary motor area. Taken together with the vertex-maximal Bereitschaftspotential which corresponds to the earlier part of the RF, the complexity of this magnetic field suggested by relatively low correlation value in single dipole model indicates the co-activation of other underlying generators besides this largest dipole. 2) The utilization of MRMF with MRCP facilitates the separation of two distinct electrophysiological events in proximity to the movement onset, which are difficult to be determined by the technique of MRCP only. Those are the motor field (MF) and the movement evoked field I (MEFI) in MRMF, and the parietal peak motor potential (ppMP) and the frontal peak motor potential (fpMP) in MRCP, which occur approximately 20 and 100 msec after EMG onset, respectively. These two subcomponents may imply the culmination of motor cortex and sensory feedback activation, respectively. Combined study of MRMF and MRCP will provide better definition of cortical events related to voluntary movement than the study of either modality alone.

[Dilated pericerebellar fluid space in patients with chronic subdural hematoma]

It is not uncommon to observe the dilation of the pericerebellar fluid space (PCFS) on CT in patients with chronic subdural hematoma (CSDH). CT scans of 92 patients with CSDH proven by surgery were reviewed with respect to the dilatation of PCFS and we evaluated the incidence of dilated PCFS and the relationship between PCFS and other factors. There were 68 males and 24 females. Patients ranged in age from 20 to 90 years (mean 65.2 years). Another 50 patients without CSDH were also reviewed as a control group. A new PCFS grading based on the CT findings was proposed, divided into 3 grades as follows. In grade 0, no PCFS could be seen on CT scans. In grade 1, PCFS could be detected along the posterior aspect of the petrous pyramid, and in grade 2, PCFS could be seen not only along the posterior aspect of the petrous pyramid but also under the tentorium cerebelli. The dilation of PCFS was seen in 78 patients (84.8%) out of the 92 cases. In 50 patients without CSDH (control group), the dilatation of PCFS was noted only in 6 (12%). The dilatation of PCFS was almost always seen on the same side as the CSDH. Among many factors, the significant factor was the degree of the midline shift, the bigger the midline shift caused by CSDH, the larger was the dilated PCFS. Although the mechanism of the dilated PCFS in patients with CSDH is not clear, it is postulated that the mechanism is caused by CSF flow disturbance, compression or adhesion of the subarachnoid space due to CSDH.(ABSTRACT TRUNCATED AT 250 WORDS)