Epstein-Barr virus BHRF1 protein protects intestine 407 epithelial cells from apoptosis induced by tumor necrosis factor alpha and anti-Fas antibody

Tumor necrosis factor (TNF) and cytotoxic T lymphocytes, which utilize Fas to induce apoptosis in target cells, are known to play a critical role in the host defense against viral infection. In this study, the Epstein-Barr virus BHRF1 protein was stably expressed in intestine 407 cells which were susceptible to cell death mediated through both the TNF receptor and Fas. WST-1 conversion assays and acridine orange staining showed that vector-transfected control cells were killed by TNF-alpha or anti-Fas antibody in a dose-dependent manner, whereas BHRF1-expressing cells were resistant to apoptosis induced by these mediators. DNA fragmentation, a characteristic of apoptosis induced by TNF-alpha and the anti-Fas antibody, was suppressed in BHRF1-expressing cells. These results indicate that the BHRF1 protein protects cells from apoptosis mediated by the TNF receptor and Fas. The role of BHRF1 as an inhibitor of cytokine-induced apoptosis during the Epstein-Barr virus lytic cycle in vivo is discussed.

Expression of Epstein-Barr virus latent membrane protein 1 protects Jurkat T cells from apoptosis induced by serum deprivation

It has been generally accepted that inhibition of apoptosis is important in the development of malignancy. To determine whether Epstein-Barr virus (EBV) latent membrane protein 1 (LMP1), the virus-coded transforming oncogene product, has an anti-apoptotic function in non-B-cells, Jurkat T cells were transfected with the LMP1-expression vector pSV2gptMTLM consisting of the human metallothionein promoter and were selected for mycophonolic acid resistance. LMP1-expressing clones of Jurkat cells showed resistance to apoptosis induced by serum deprivation. In LMP1-expressing clones, although the levels of Bcl-2 and Bax were similar to those in the clones of vector transfectants or parental cells, c-Myc expression was significantly depressed. Down-regulation of c-Myc by LMP1 was confirmed by using LMP1-expressing clones treated with CdCl2. Addition of c-myc antisense oligonucleotides to Jurkat cells specifically inhibited apoptosis induced by serum deprivation at the concentrations which suppressed c-Myc expression. These results suggest that LMP1 expression and subsequent down-regulation of c-Myc protect Jurkat T cells from apoptosis induced by serum deprivation. The significance of the anti-apoptotic function of LMP1 in non-B, Jurkat T cells is discussed in relation to the pathogenesis of EBV malignancy.

[Surgical management of extracranial internal carotid artery aneurysms]

Aneurysms of the extracranial internal carotid artery are rare but may present as a mass, with ischemic symptoms, or with fatal hemorrhage. We operated on aneurysms in four patients, two males and two females, whose ages ranged from 47 to 57 years. While a lot of etiological factors for the aneurysms have been known to include trauma, vascular dysplasia, infection or surgery using patch graft for carotid endarterectomy, three aneurysms in our series were atherosclerotic and one was spontaneously dissecting. One patient had focal neurological deficit due to embolism, two presented with a growing cervical mass, and one was symptom-free. The aneurysm was located proximal below the angle of the mandible in three patients and was distal above the angle in one. All patients were found able to tolerate test occlusion of the internal carotid before surgery. The aneurysm was trapped in one case (case 1) and was encased by vascular prosthesis in another (case 4). In the other two cases, arterial reconstruction after aneurysmal resection was carried out. In one case out of the two, the aneurysm was located at the level of 2nd cervical vertebral body (case 2). Vertical mandibular osteotomy was performed posteriorly to the exit of the inferior alveolar nerve from the bone, which gave a good view of the upper third of the internal carotid artery and facilitated primary end-to-end anastomosis. In the other case in which there was a dilated distal carotid artery and multiple aneurysms at the basilar and bilateral vertebral arteries (case 3), an extracranial-intracranial (EC-IC) saphenous vein bypass was inserted so as not to increase the hemodynamic stress in the posterior circulation. Except for a transient lower cranial nerve palsy in one case (case 2), there were no incidences of morbidity or death. Magnetic resonance angiography (MRA), Doppler ultrasonography or three-dimensional CT angiography (3-D-CT-A) was found useful in evaluating the change of aneurysmal size. It is essential in surgery for an internal carotid artery aneurysm to choose an appropriate approach characterized by its size and location. It may be important in cases with associated vascular lesions to estimate the potential hemodynamic change that might be induced by aneurysmal surgery.

[Regulation of apoptosis by the latent infection membrane protein 1 of Epstein-Barr virus]

The latent infection membrane protein 1(LMP1) of Epstein-Barr virus(EBV) protects human B cells from apoptosis by up-regulating expression of Bcl-2 and A20. We have demonstrated that LMP1 transfectants of Jurkat T cells are resistant to apoptosis induced by serum depletion without affecting Bcl-2/Bax system. Expression of LMP1 in epithelial cells have affected apoptosis induced by TNF-alpha but not apoptosis induced by anti-Fas antibodies, suggesting that LMP1 is involved in the signal pathway specific for TNF receptor. These results indicate that LMP1 regulates apoptosis by different mechanisms among each cell type. The regulation of apoptosis by LMP1 is discussed in relation to EBV infection.

Evidence for facilitation of motor evoked potentials (MEPs) induced by motor imagery

This study examined the extent to which motor imagery can facilitate to specific pools of motoneurons. Motor commands induced by motor imagery were subthreshold for muscle activity and were presumably not associated with any change in background afferent activity. To estimate excitability changes of flexor carpi radialis (FCR) muscle motoneuron in spinal and cortical level, electric stimuli for recording H-reflex and transcranial magnetic stimulation (TMS) for recording motor evoked potentials (MEPs) were used. During motor imagery of wrist flexion, remarkable increases in the amplitude of the MEP of FCR were observed with no change in the H-reflex. Furthermore, facilitation of antagonist (extensor carpi radialis; ECR) was also observed. Therefore, it is concluded that internal motor command can activate precisely cortical excitability with no change in spinal level without recourse to afferent feedback.

Clinical significance of immunohistochemically detectable p53 protein in renal cell carcinoma

OBJECTIVE

To elucidate the clinical significance of p53 protein in renal cell carcinoma (RCC).

MATERIALS AND METHODS

The p53 protein in the paraffin-embedded materials taken from 72 patients with RCCs was evaluated immunohistochemically and was compared with the histological findings, expression of proliferating cell nuclear antigen (PCNA), genetic instability as assessed by 2c deviation index (2cDI) and 5c exceeding rate (5cER) as well as clinical outcome.

RESULTS

The p53 positivity was demonstrated only in a localized and/or focal area of the cancerous tissue. The positive rate of p53 protein was 40.3% in this study. The p53 protein significantly correlated with nuclear grade as well as PCNA expression (p < 0.001 and p < 0.01, respectively). Although there was a wide scatter of 2cDI and 5cER values between p53 positive and negative RCCs, the RCC with positive p53 exhibited significantly higher values in 2cDI as well as 5cER, as compared to that with negative p53 (p < 0.02 and p < 0.005, respectively). However, some of the RCCs with negative p53 showed relatively higher values in 2cDI and 5cER. Using univariate analysis, the prognostic relevance was noted in T, N, M categories, age and p53 positivity, while it was not in 2cDI, 5cER and PCNA expression. Multivariate analysis demonstrated that N category and p53 positivity were independently significant indicators in predicting survival.

CONCLUSIONS

The presence of p53 protein might reflect the genetic instability already occurred. The p53 positivity reflecting a high cellular proliferation could afford an additional but useful information when predicting survival in patients with RCC.

Hemodynamics in an arterial union--simulation study on therapeutic unilateral vertebral artery occlusion

Hemodynamic changes following unilateral vertebral artery (VA) occlusion were investigated in a rat model. The left carotid artery was resected and anastomosed to the right side in an end-to-side fashion to create a half-ring bypass. The distal side of the bypass was regarded as a union of VAs. Changes in the geometry, histology and hemodynamics in the union were investigated after the recipient artery was ligated. Intimal thickening was most prominently observed in the recipient arterial segment distal to the ligation site, where the lumen was obliterated. However, the portion of the lumen within 2.6 +/- 0.6 (mean +/- s.d.) mm, a distance of 2.9 +/- 0.6 times the internal diameter from the union, was not obliterated. The angle of the union was positively related to the length of this residual lumen. The results of this study explain some of the pathogenesis in unsuccessful aneurysmal thrombosis or brain stem infarction after therapeutic unilateral VA occlusion.

Immunohistochemical analysis of proliferating cell nuclear antigen, p53 protein and nm23 protein, and nuclear DNA content in transitional cell carcinoma of the bladder

BACKGROUND

Transitional cell carcinoma (TCC) of the bladder displays an unpredictable biologic behavior and the morphologic methods of grading tumor malignancy are often insufficient to predict the clinical outcome of patients with TCC of the bladder. Thus, the new indicator should reliably reflect prognosis. In this study, the authors determined the prognostic significance of proliferating cell nuclear antigen (PCNA), p53 protein, and nm23 protein, as well as nuclear DNA content in specimens with TCC of the bladder.

METHODS

Paraffin embedded materials taken from 77 patients with nonmetastatic untreated TCC of the bladder (classified as pTa-3b, NO, MO) treated with total cystectomy were employed in this study. PCNA expression, p53 protein and nm23 protein immunoreactivities, and the parameters for nuclear DNA content such as 2c deviation index (2cDI) and 5c exceeding rate (5cER) were evaluated using a computer-assisted image analyzer, and the results were compared with histologic findings and clinical outcome.

RESULTS

PCNA expression positively correlated with p53 protein and nm23 protein immunoreactivities, 2cDI value, and 5cER. In addition, histologic grade positively correlated with all of these five parameters. Similarly, pT category and disease progression positively correlated with all of the five parameters, except for nm23 protein immunoreactivity. In tumors with high genetic instability as judged by 2cDI and 5cER, both PCNA expression and p53 protein immunoreactivity were elevated, whereas nm23 protein immunoreactivity was not. However, the percent coefficient of variation in PCNA expression was smaller than that observed in p53 protein immunoreactivity in each group of genetic instabilities. In univariate analysis, prognostic potential was found with histologic grade, pT category, PCNA expression, p53 protein immunoreactivity, 2cDI value, and 5cER, but was not noted in nm23 protein immunoreactivity. Multivariate analysis indicated that quantity and intensity of PCNA expression (chi 2 = 8; P = 0.0047 for quantity and chi 2 = 8.71; P = 0.0032 for intensity) and 2cDI value (chi 2 = 5.52; P = 0.0019) were independent variables of histologic grade and pT category when predicting survival. However, p53 protein and nm23 protein immunoreactivities and 5cER were not of independent significance.

CONCLUSIONS

The tumor growth fraction as assessed by PCNA immunostaining is an independently significant predictor for survival of patients with TCC of the bladder.

[Hemodynamic simulation study of cerebral arteriovenous malformations: changes of wall stress and early detection of NPPB]

Obliteration procedures for large high-flow arteriovenous malformations (AVM) were simulated using a compartmental flow model to investigate the role of altered autoregulatory conditions in the development of hyperperfusion and normal perfusion pressure breakthrough (NPPB). Since the arterioles are primarily responsible for autoregulatory function, the role of these structural changes on the development of hyperperfusion was also studied by evaluating the wall thickness (T), internal radius (Ri) and tangential wall stress (sigma). As the AVM flow was decreased during the obliteration procedures, the perfusion pressure (delta P) of the brain tissue surrounding the AVM increased. When the autoregulatory condition was impaired [AR (-)] and the lower limit of the autoregulatory pressure range (LAR) was shifted from 60 mmHg (LAR60) to 40 mm Hg (LAR40), the flow volume in the surrounding brain (Fb) increased markedly, from 67 ml/100g/min to 92 ml/100g/min, with the progress of the obliteration procedures. In these conditions, T/Ri was supposed to be constant and sigma value increased uniformly. In the presence of the autoregulatory mechanism [AR (+)], T/Ri increased against increasing delta P, which resulted in smaller sigma value than that under AR (-) conditions. When the contracted vascular wall yielded on the process of increasing wall stress, delta P and feeder pressure (Pf) decreased to some degree. Concomitantly increase of the sigma value and marked hyperperfusion developed in the brain. The yield of the contracted vascular wall would result in the decrease of a pressure gradient across the arteriole and the reciprocal increase of pressure load on the walls of the capillary and venula, which might lead to NPPB. Since the decrease of delta P or Pf during the progress of the obliterating procedures is considered specific to the appearance of hyperperfusion or NPPB, monitoring these parameters would be useful for its early detection. If the upper limit of the autoregulatory pressure range was assumed to decrease and become the yield point in the brain surrounding high flow AVMs, hyperfusion or NPPB could be considered to develop in the conditions with the autoregulatory pressure range being narrowed and/or shifted to the lower pressure level. Induced systemic hypotension was found to be effective in reducing the magnitude of Fb, delta P, and Pf when induction was appropriately performed in stepwise fashion. T/Ri and sigma were kept in narrow ranges compared to those before induction of hypotension.

[Anti-apoptotic function of the Epstein-Barr virus LMP1 and BHRF1 proteins]

Two Epstein-Barr virus (EBV) gene products, latent infection membrane protein 1 (LMP1), expressed mainly in latent infection, and BHRF1, expressed in lytic infection, have the ability to promote cell survival. LMP1 protects human B cells from apoptosis by upregulating expression of Bcl-2 and A20. We have demonstrated that LMP1 transfectants of Jurkat T cells are resistant to apoptosis induced by serum depletion without affecting the Bcl-2/Bax system. Overexpression of LMP1 in epithelial cells inhibits apoptosis induced by TNF-alpha, but not by anti-Fas antibodies. These results indicate that the anti-apoptotic mechanism of LMP1 differs among different cell types. BHRF1 can prevent apoptosis induced by TNF-alpha and anti-Fas antibodies in epithelial cells. The implication of the anti-apoptotic function of LMP1 and BHRF1 is reviewed in relation to EBV infection.

Intravesical instillation of epirubicin: effect on tumour recurrence in patients with dysplastic epithelium after transurethral resection of superficial bladder tumour

OBJECTIVE

To evaluate whether the intravesical instillation of epirubicin is effective in preventing the recurrence of tumour in the bladder where dysplastic mucosa remains after transurethral resection of tumour.

PATIENTS AND METHODS

Biopsy specimens were taken from apparently normal areas of the bladder mucosa in patients undergoing transurethral resection of the primary tumours. Of the 75 evaluable patients, 18 (24%) had abnormalities in at least one or more specimens. The patients were divided into two groups, 57 with normal and 18 with abnormal biopsy results. Intravesical chemotherapy with epirubicin (20 mg/40 mL saline) was randomized to patients in each group. Tumour recurrence rates were estimated and compared amongst the groups. Factors related to tumour recurrence were evaluated using univariate and multivariate analyses.

RESULTS

The risks of tumour recurrence and progression were evaluated in 18 patients with concomitant mucosal abnormalities. All 10 patients with abnormal biopsy results who were treated with epirubicin had recurrence of tumour within a mean interval of 9 months, whereas six of eight controls had recurrence within a mean of 10.9 months. While there was progression in grade in four of 10 patients with abnormal biopsy results and treated with epirubicin, none of the recurrent tumours in six control patients with mucosal abnormalities progressed in grade. The overall recurrence-free rate of the patients with mucosal abnormalities was higher in controls than in those receiving epirubicin, but the difference was not statistically significant. There were no significant differences in recurrence rate for those treated with epirubicin and controls in the 57 patients with normal biopsy results. Univariate analysis showed that the recurrence-free rates were significantly influenced by tumour multiplicity and the mucosal biopsy results (P < 0.001 and P = 0.02, respectively). In a Cox proportional-hazards model, tumour multiplicity alone had prognostic significance for tumour recurrence (P = 0.002).

CONCLUSIONS

The prophylactic intravesical instillation of epirubicin had no effect in preventing tumour recurrence and, conversely, it may promote tumour progression in bladders with dysplastic mucosal changes.

Contralateral external carotid-to-external carotid artery (half-collar) saphenous vein graft for common carotid artery occlusion

In a patient having common carotid artery occlusion complicated with contralateral internal carotid artery stenosis, a saphenous vein bypass graft was performed from the contralateral external carotid artery to the ipsilateral external carotid artery simultaneously with contralateral carotid endarterectomy. The bypass was patent 1 year later and the patient was free from fainting spells. Among a number of the reconstructive surgical procedures, this "half-collar bypass" can be placed adequately in the subcutaneous soft tissue so that head or mandibular movement does not displace or compress the graft. Intraoperative hemodynamic measurements were considered useful in determining surgical options.

Hemodynamic simulation study of cerebral arteriovenous malformations. Part 2. Effects of impaired autoregulation and induced hypotension

The hemodynamic changes occurring during obliteration procedures for arteriovenous malformations (AVM) have not been fully elucidated. Therefore, we undertook a simulation study using a compartmental flow model to investigate the role of altered autoregulatory conditions in the development of hyperperfusion during obliteration of large high-flow AVM. Induced hypotension was also simulated to evaluate its usefulness in reducing the incidence and severity of the event. As the AVM flow was decreased during the obliteration procedures, feeder pressure increased and drainer pressure decreased, with a concomitant increase in the perfusion pressure in the brain tissue surrounding the AVM. Cerebral blood flow (CBF) remained constant at 50 ml 100 g-1 min-1 in the presence of autoregulation and increased to 67 ml 100 g-1 min-1 in its absence. When the lower limit of the autoregulatory pressure range (LAR) was shifted from 60 to 50 or 40 mm Hg, the flow volume increased markedly from 67 to 77 ml 100 g-1 min-1 or to 92 ml 100 g-1 min-1 after complete obliteration. Decrease in LAR would be a cause of the hyperperfusion. Induced systemic hypotension was found to be effective in reducing the magnitude of these hemodynamic changes, when induction was appropriately performed in a stepwise fashion. A simulation study is useful in clarifying the various hemodynamic changes that develop during the treatment of AVM.

A large thrombosed superior cerebellar artery aneurysm: a case report

MATERIAL AND RESULT: A large thrombosed aneurysm arising from the distal superior cerebellar artery was successfully resected.

DISCUSSION AND CONCLUSION

An aneurysm in this location is very rare. Accumulation of intraoperative hemodynamic data may be useful in evaluating the capacity of collateral circulation.

Factors related to the outcome of M-VAC in 101 patients with advanced urothelial cancer

The objective of this study is to identify factors related to the results of intravenous methotrexate, vinblastine, doxorubicin and cisplatin (M-VAC) for 101 patients with advanced urothelial cancer. The effects of various factors on response and survival were evaluated using univariate and multivariate analyses. The factors included in the analyses were sex, age, performance status (PS), primary site, histological type, grade, T category, N category, M category, prior chemotherapy, prior radiotherapy, and dose of chemotherapeutic drugs. Univariate analysis revealed that M category and prior chemotherapy had a significant correlation with the response, and that factors significantly related to survival were PS, primary site, N category, M category, prior chemotherapy and prior radiotherapy. A multiple logistic regression model showed that N category, M category and prior chemotherapy were related to response. The response rates of patients with N1-4 or M1 or prior chemotherapy were lower than those with N0 or M0 or without prior chemotherapy. A Cox regression model demonstrated that PS and M category independently contributed to survival. Patients with high grade PS or distant metastases showed a lower survival rate than those with low grade PS or localized diseases. M category was the most important factor related to response and survival. These results seem to indicate the low effectiveness of M-VAC for distant metastases, and the inability of this regimen to improve the outcome of patients with advanced urothelial cancer.

Molecular analysis of mutations induced by 2-chloroacetaldehyde, the ultimate carcinogenic form of vinyl chloride, in human cells using shuttle vectors

Vinyl chloride (VC) is a carcinogen associated with human and animal cancers. The ultimate carcinogenic form of VC, 2-chloroacetaldehyde (CAA), has been suspected to be mutagenic and we confirmed the mutagenicity of CAA using a modified shuttle vector plasmid. Base sequence analyses of 109 mutant plasmids with mutations in the supF gene, which were treated with CAA and propagated in the cultured human cells, revealed that more than half of the single base substitutions were G:C to A:T transitions with eight hotspots. The majority of the mutations involving G:C base pairs were in 5'-AAGG-3' or 5'-CCTT-3' sequences suggesting that these sequences are the main targets of mutagenesis caused by CAA.

[Two cases of acute massive pulmonary embolism diagnosed by pulmonary angiography with Swan-Ganz catheter]

We report two cases of acute massive pulmonary embolism diagnosed at the bedside by pulmonary angiography with Swan-Ganz catheter. In both cases the patients (women 48 and 49 years old) went into shock after surgery. Pulmonary angiography with Swan-Ganz catheter was done at the bedside to confirm the diagnosis. In both cases this revealed filling defects. Hemodynamics improved after-thrombolytic therapy. In general, pulmonary embolism can be definitively diagnosed by lung perfusion scan or pulmonary angiography. Pulmonary angiography with a Swan-Ganz catheter is useful in hospitals without complicated instruments, but is indicated only for unmovable and unstable patients with hemodynamic problems.

[Detection of cortical infarcts in brain MR imaging: feasibility of short-TR-T2-weighted imaging using a fast spin echo sequence]

MRI of the brain using a fast SE sequence is often performed with a TR above 5000 msec, so there is a tendency for the signal of CSF to become too high. However, when cerebral atrophy is marked, small lesions of the brain parenchyma can be hard to detect. Therefore, we examined short-TR-T2-weighted images using a fast spin echo sequence. The 58 subjects included 33 men and 25 women, and cortical infarction was detected in five of them. On the short-TR-T2WI sequences, the infarct lesions were imaged as areas of higher signal intensity than cerebrospinal fluid, the signal of which was reduced. In cortical infarction cases, fluid-attenuated inversion recovery (FLAIR) images can detect the lesion more easily, but FLAIR sequences cannot be obtained with all MR equipment. Short-TR-T2WI, which readily yields images comparable to those of FLAIR, is an useful method.

Significance of rapid urease test for identification of Helicobacter pylori in comparison with histological and culture studies

Helicobacter pylori in the stomach is an etiological factor of gastritis and peptic ulcer. It is now considered that gastric cancer can be, at least in some cases, a late complication of H. pylori infection. In 123 consecutive endoscopic antral biopsies obtained from patients with the Okamoto Hospital, the specimens were subjected to the rapid urease test (RUT), histology (H&E stain), and culture, for the identification of H. pylori. The results of these methods were compared semi-quantitatively in order to evaluate these detection methods for identifying H. pylori. The results of these methods were found to agree well, with the Spearman's rank correlation coefficient between RUT and culture being 0.90 (P < 0.01) and that between histology and culture being 0.80 (P < 0.01). RUT is considered to be a very simple, sensitive, and highly specific test which enables the endoscopist to diagnose H. pylori infection.

Nitric oxide inhibits Epstein-Barr virus DNA replication and activation of latent EBV

Nitric oxide (NO), a mediator of biological functions, has antimicrobial activity against a variety of pathogens including viruses. Effects of NO donors on EBV replication in two EBV lytic systems, Raji cells infected with P3HR-1 virus and P3HR-1 cells activated with TPA plus n-butyrate, were studied. S-nitroso-N-acetylpenicillamine (SNAP), which generates NO when placed in an aqueous solution, and 3-morpholinosydnonimine (SIN-1), which liberates NO and O2-, resulting in the formation of peroxynitrite, were used as NO donors. Immunoprecipitation analysis showed that in superinfected Raji cells, SNAP inhibited EBV late protein synthesis but not EBV early protein expression. Analysis of the structure of EBV DNA termini demonstrated that SNAP suppressed the amplification of EBV DNA in superinfected Raji cells at a dose which did not affect synthesis of EBV early proteins required for EBV DNA replication. In TPA plus n-butyrate-treated P3HR-1 cells, SNAP inhibited synthesis of both early and late proteins of EBV. Northern blot analysis of RNA expressed in TPA plus n-butyrate-treated P3HR-1 cells demonstrated that expression of EBV immediate-early mRNAs coded from BZLF1 and BRLF1 genes was inhibited by SNAP. SIN-1 showed no or little effect on EBV replication in both cell systems. Cell viability and cellular protein synthesis were not affected by either NO donor under the conditions used. These findings suggest that NO prevents EBV replication by inhibiting EBV DNA amplification during the lytic phase of the life cycle as well as by blocking activation of the latent EBV genome. The mechanism for inhibiting of EBV replication by NO was discussed in relation to the role of NO in EBV latency in vivo.

[Lipoprotein Z]

The term lipoprotein Z (remnant-like particles) refers to lipoproteins that do not have an immunoaffinity to gel mixture of anti-apo A-I and apo B100 monoclonal antibodies (JI-H antibody). Lp Z is enriched in apo E and cholesterol esters. Quantification of this lipoprotein provides a useful index of atherogenic chyromicron and VLDL remnant particles. Serum concentration of this lipoprotein is well correlated to serum triglycerides in normal subjects and patients with hypertriglyceridemia, and to serum LDL-cholesterol in normal subjects. The normal range of this lipoprotein is below 5 mg/dl and the increased serum concentration is often observed in ischemic heart disease, diabetes mellitus, hypertriglyceridemia and fatty liver.

Giant thrombosed vertebral artery aneurysm treated by extracranial-intracranial bypass and aneurysmectomy--case report

A 42-year-old male presented with a giant thrombosed aneurysm of the left vertebral artery. The aneurysm was resected through a combined subtemporal and suboccipital approach after a saphenous vein bypass graft was placed between the right external carotid artery and the posterior cerebral artery. Intraoperative measurements of the blood flow volume and pressure demonstrated good blood flow in the bypass. Postoperatively, uncontrollable hypertension resulted in huge intracerebral hematoma formation and increased intracranial pressure. Control of systemic hypertension is essential in such patients.

The relationship between spontaneous calcium oscillations and cell proliferation in cultured smooth muscle cells

The relationship between spontaneous Ca2+ oscillations and cell proliferation was investigated in cultured longitudinal muscle cells from guinea pig ileum. BAPTA, caffeine, thapsigargine and La3+ suppressed the spontaneous Ca2+ oscillations and the DNA synthesis at 5.0 mM, 10.0 mM, 15.62 nM and 0.5 mM, respectively, whereas verapamil, nicardipine and ryanodine did not suppress either. However, BAPTA and La3+ did not inhibit the DNA synthesis at 1.25 mM and 0.13 mM, but did suppress the Ca2+ oscillations even at 1.0 mM and 0.1 mM, respectively. These results show that the spontaneous Ca2+ oscillations are not prerequisite for the cell proliferation.

[EC-IC bypass surgery using saphenous vein graft: technical improvement in our experience]

We managed ten cases of EC-IC bypass using a vein graft; six cases with multiple cerebral arterial occlusion and four cases with aneurysm necessitating therapeutic occlusion of the parent artery (Table). Patency of the graft was confirmed in seven cases on long-term follow-up ranging from 7 months to 5 years. Of the ten cases, two died within 7 days after surgery from causes unrelated to the bypass and one was lost in follow-up surgery. Hemorrhagic infarction was observed in two cases, one of which underwent removal of the hematoma. In five cases with cerebral occlusive disease, there were no additional ischemic events and two cases with giant aneurysms showed improvement of visual acuity and extraocular movement. We improved on several surgical techniques for vein graft. We used small hemoclips to occlude branches of the saphenous vein instead of ligating them, which shortens the harvesting time of the saphenous vein. Vessel cannula with a small-sized elegant tip and one-directional valve (DLP, INC., USA) was also used to inflate or deflate vein grafts with saline. It was easily attached to the graft and minimized air entrapment in the lumen. Small clips for microvascular anastomosis (Mizuho INC., Japan) were used to temporarily occlude branches or perforators from the recipient artery. One of the branches of the graft was dissected long enough, through which intraluminal air or thrombus was washed out at the final stage of the surgery. These procedures are useful for shortening occlusion time of the recipient artery and decreasing the risk of embolism.

Simulation study on therapeutic vertebral artery occlusion for VA-PICA giant aneurysm

We investigated haemodynamic effects of therapeutic vertebral artery (VA) occlusion on giant aneurysms at the bifurcation of the VA-posterior inferior cerebellar artery (PICA). An hydraulic model of the human vertebro-basilar artery was manufactured from glass and silicone tubes. Glass-spheres 2.5 cm in diameter were placed at the bifurcation as model aneurysms with respective distances of 8.5, 7.5, 6.5 and 5.5 mm between the VA union and aneurysmal neck. A 40% glycerol solution was perfused in this system and the half-life of the dye injected into aneurysms was regarded as an index of intra-aneurysmal stagnation. Flow conditions in aneurysms depended on the presence or absence of the effect of contralateral VA flow as well as the PICA flow. The half-life increased significantly after VA occlusion proximal to the PICA when the aneurysmal neck was more than 7.5 mm away from the VA union and PICA flow volume was less than 12 ml min-1. The half-life in aneurysms located within 6.5 mm from the union changed little after VA occlusion regardless of the PICA flow volumes. The haemodynamic simulation study would be helpful in speculating on the efficacy of this treatment.