Factor XI contributes to thrombus propagation on injured neointima of the rabbit iliac artery

BACKGROUND

Thrombus formation through the activation of tissue factor (TF) and factor (F) XI is a critical event in the onset of cardiovascular disease. TF expressed in atherosclerotic plaques and circulating blood is an important determinant of thrombogenicity that contributes to fibrin-rich thrombus formation after plaque disruption. However, the contribution of FXI to thrombus formation on disrupted plaques remains unclear.

METHODS

A mouse monoclonal antibody against FXI and activated FXI (FXIa) (XI-5108) was generated by immunization with activated human FXI. Prothrombin time (PT), activated partial thromboplastin time (APTT), bleeding time, and ex vivo platelet aggregation in rabbits were measured before and after an intravenous bolus injection of XI-5108. We investigated the role of FXI upon arterial thrombus growth in the rabbit iliac artery in the presence of repeated balloon injury.

RESULTS

The XI-5108 antibody reacted to the light chain of human and rabbit FXI/FXIa, and inhibited FXIa-initiated FXa and FXIa generation. Fibrin-rich thrombi developed on the injured neointima that was obviously immunopositive for glycoprotein IIb-IIIa, fibrin, TF, and FXI. Intravenous administration of XI-5108 (3.0 mg kg(-1)) remarkably reduced thrombus growth, and the APTT was significantly prolonged. However, PT, bleeding time and platelet aggregation were not affected.

CONCLUSIONS

These results indicate that plasma FXI plays a potent role in thrombus growth on the injured neointima. Inhibition of plasma FXI activity might help to reduce thrombus growth on ruptured plaques without prolonging bleeding time.

Late flare-up of nephrotic lupus nephritis transforming histological pattern and autoantibody reactions

A 15-year-old boy developed a nephrotic syndrome. At that time, autoantibodies related to systemic lupus erythematosus (SLE) had been persistently negative, even on repeated evaluation. C1q was normal, but C4, C3 and CH50 were low. Renal biopsy revealed membranous lupus nephritis (LN) based on the new classification of glomerulonephritis in SLE [Weenig et al. 2004]. We did not establish our diagnosis of SLE on the criteria of the American Rheumatism Association (ARA). The patient showed complete remission ofnephrotic syndrome treated with prednisolone and cyclophosphamide. Thereafter, he had no proteinuria and clinical evidence of SLE for 22 years. At the age of 37, however, he developed facial discoid eruption, proteinuria in the nephrotic range, hypocomplementemia and positive reaction to autoantibodies of SLE. Light microscopic findings of renal biopsy indicated mesangial LN, which showed "full-house" immunofluorescence and mesangial dense deposits associated with diffuse epithelial cell foot process effacement in electron microscopy. Steroid therapy was very effective. This case initially showed autoantibody-negative and hypocomplementemic LN with membranous type, and transformed to SLE with mesangial LN after a long interval.

Distribution of dioxins in surface soils and river-mouth sediments and their relevance to watershed properties

The dioxins toxic equivalent (TEQ) concentration in surface soils, river sediments and river-mouth sediments was measured by the CALUX assay in the Yasu and Ado River basins around Lake Biwa, Japan. In order to examine the distribution of dioxins in each watershed, we evaluated and compared the correlation between the dioxins TEQ concentration and the solid characteristics (i.e. organic carbon content and particle size distribution) of all samples. In both basins, the dioxins TEQ concentration in forest soil correspondingly showed a very good linear relationship to organic carbon content. On the other hand, the dioxins TEQ concentration in paddy field was significantly high, although organic carbon content was relatively low. Generally, the smaller particles have the higher dioxins TEQ concentrations in surface soils, and river sediments were composed of very coarse particles and had relatively low dioxins TEQ concentration. Therefore, we expected high dioxins TEQ concentration in river-mouth sediment, which was, however, not the case. Although the dioxins TEQ concentration in river-mouth sediments is low, the degree of dioxins pollution was different in each basin. The difference was considered to come from the difference of watershed properties including land use, river-slope, dam construction as well as the surface soil pollution.

Computer simulation of flow dynamics in paraclinoidal aneurysms

SUMMARY

Endovascular treatment, which is very useful method especially for paraclinoidal aneurysms, has the limitations of coil compaction and recanalization, which are difficult to predict. We tried to understand flow dynamic features, one of the important factors of such problems, using computer flow dynamics (CFD) simulations. CFD simulations were made in paraclinoidal aneurysm model of different size and protruded directions. Flow patterns, flow velocities and pressure are analyzed. Although the pressure on the aneurismal orifice is highest in the aneurysm protruding vertically - upward, the flow velocity is highest in the superior-medial protruding one. Significant difference is not observed in either flow patterns, flow velocities or pressures on the aneurismal orifices between the sizes of aneurismal sac. Among paraclinoidal aneurysms, an aneurysm protruding to superior-medially receives the most severe haemodynamic stresses at the orifice and the aneurysm size does not cause significant differences in the aspect of flow dynamics. It should be considered in the treatment of such aneurysms.

Transverse fundal uterine incision in a patient with placenta increta

In cases with placenta accreta occurring on the previous cesarean scar, a longitudinal incision is generally appropriate. However, the placenta may prevent both a longitudinal and lower transverse incision. We report a case of placenta increta on the previous cesarean scar, and discuss the role of transverse fundal uterine incision.

Feasibility of photocrosslinkable chitosan as an embolization material for aneurysms. Biological reaction after aneurysm embolization

SUMMARY

The purpose of this study was to evaluate the feasibility of photocrosslinkable chitosan as an embolization material for aneurysms. Three experimental aneurysms were created in three Japanese white rabbits. All of the aneurysms were packed with chitosan hydrogel. Histopathologic data were analyzed on two, seven, and 30 days after embolization. Unorganized clots and minimal inflammation around the applied chitosan hydrogel were observed two days after implantation. After seven days, the chitosan was reduced and inflammatory response appeared. At 30 days, most of the aneurysm lumen was replaced with inflammatory cells, and the remaining chitosan was not observed. Severe complications such as anaphylaxis did not occur after the embolization with the chitosan. These results suggest that photocrosslinkable chitosan might be a candidate for an embolization material for endovascular treatment of cerebral aneurysms.

Clinical features of the posterior horn tear in the medial meniscus

INTRODUCTION

A lower threshold of suspicion is necessary for the appropriate diagnosis of a posterior horn tear in the medial meniscus. In these cases, radial tears or meniscus detachment from its insertion follow minor trauma and precipitate severe knee pain in middle-aged and elderly patients. The purpose of this paper is to demonstrate the key points for diagnosis through examination of the clinical features of this tear.

MATERIALS AND METHODS

Arthroscopic examination of 250 knees with medial meniscus tears (and no ligamentous injuries; over 40 years old) identified 26 knees (26 tears) with a posterior horn tear. Of these 26 tears, 16 were radial, and 10 were detached.

RESULTS

Eighty-five percent of patients could recall discrete events that preceded the pain. They described these events as a click or a feeling of shock. Afterwards, most patients complained of severe pain or giving way. Hydrarthrosis involving more than 5 ml was present in 81%. Most radiographs (92%) appeared nearly normal.

CONCLUSION

It is important to note that this type of tear of the posterior horn in the medial meniscus is not rare. Because this area is difficult to visualize arthroscopically, it may be overlooked unless the threshold of suspicion is lowered.

Radiological and pathological changes in the sinus of an experimental arteriovenous fistula of the rat

SUMMARY

The object of this study is to evaluate the radiological and pathological changes in the sinus of an experimental arteriovenous fistula of the rat. Twenty-five male Sprague-Dawley rats, including two control rats, were used for this study. A venous hypertension model in the transverse sinus was induced by means of anastomosis of a common carotid artery (CCA) to the ipsilateral external jugular vein (EJV). Rats were sacrificed 11 to 42 weeks after the procedure, then histopathological and immunohistopathological examinations were performed for the resected transverse sinus. Follow-up angiography was performed two to three weeks after the anastomosis in every case, and five months later in two rats. Patency of the anastomosed portion was confirmed in 12 of the 23 anastomosed rats. An ipsilateral carotid angiogram demonstrated a highflow arteriovenous (AV) shunt from the CCA to the sigmoid-to-transverse sinus and draining into the contralateral juglar vein. A contralateral angiogram displayed a steal phenomenon via the communicating artery. Histopathologically, the vein of the anastomosed portion and the transverse sinus were markedly dilated in with cases. There was a thickening the connecting tissue and a proliferation of fibroblast in four (50%) of the eight cases. Thrombus formation in the transverse sinus was found in one case. VEGF stained strongly in the endothelial hypertrophied area and in fibrous connective tissue around the transverse sinus compared to the control sinuses. Our results from this long-term observation of the radiological and pathological changes in the sinus exposed to hypertension resembled the clinical findings of a dural AV fistula.

Treatment strategy for aneurysms of the posterior cerebral artery

SUMMARY

The authors carried out a retrospective review of the records of 12 patients with aneurysms of the posterior cerebral artery (PCA). Four were asymptomatic, 1 presented with a mass effect, and 7 with a subarachnoid haemorrhage (SAH). Of the 7 ruptured aneurysms, 3 were embolized and 2 were clipped. However, 2 patients died from rebleeding before any treatment. Of the 5 unruptured aneurysms, 1 was embolized with coils but the remaining 4 have been conservatively observed. No aneurysms have ruptured during the follow-up period, and 3 have thrombosed spontaneously. According to our results, the PCA aneurysms should be treated aggressively in the early phase. Although the preservation of the anatomical integrity of the PCA should naturally be one of the prime objectives, PCA occlusion may sometimes be inevitable when treating large or fusiform aneurysms. On the other hand, conservative therapy is one of the options for the treatment of incidentally encountered unruptured ones, because these have the possibility of spontaneous thrombosis.

Chart analysis of body composition change among pre- and postadolescent Japanese subjects assessed by underwater weighing method

OBJECTIVE

To examine the effect of age on the relationship between fat-free mass (FFM) and fat mass (FM), and fat-free mass index (FFMI) and fat mass index (FMI) by applying body composition chart analysis on pre- and postadolescent Japanese subjects.

SUBJECTS AND METHOD

A sample of 516 children (244 boys and 272 girls) ranging in age from 11 to 17 y and 840 adults (288 male and 552 female subjects) ranging in age from 18 to 59 y were studied to determine a body composition by an underwater weighing method. FMI and FM were put on an x- and y-axis in body composition chart 1, and FFMI (FFM/ height(2)) and FMI (FM/height(2)) were taken on an x- and y-axis in body composition chart 2.

RESULTS

In body composition chart 1, the plots for male subjects stayed flat from 11 to 14 y and after that a steady growth of FFM concurring with the FM growth was observed. During the adult stage, steady increments of FM and gradual decreases of FFM were observed. In body composition chart 2, steady increases of FFMI and gradual decreases of FMI were indicated in the male preadolescent period. In the adult stage, FFMI decreased year by year, although the FMI continued to increase. In female subjects, a conspicuous increase of FMI was observed throughout all periods of the present subjects. After middle age, the decline of FFMI was characteristically demonstrated in the chart.

CONCLUSION

The relationships between FFM and FM are characteristically delineated on the body composition charts demonstrating clear gender differences. The change of body mass index was not reflecting the change of adiposity level in male subjects, although it was occurring along with the changes of the adiposity level in female subjects.

Nutcracker syndrome associated with severe anemia and mild proteinuria

A 70-year-old man was referred to our hospital with the chief complaint of gross hematuria. Urinalysis revealed gross hematuria (3+, RBC 100/HPF or more) and mild proteinuria (3+, 1.8 g/day) with no urinary casts. Computed tomography of the abdomen showed compression of the left renal vein between the superior mesenteric artery and the aorta. Ultrasonography showed an increased flow velocity at the stenotic portion of the left renal vein. An aortography and selective left renal arteriography showed that there was no evidence of tumor vessels or arterial abnormalities in the arterial phase. However, the venous phase revealed a stenosis of the left renal vein just lateral to the aorta as well as a reflux of contrast material toward the left gonadal vein which was dilated. In addition, cystoscopy revealed left ureteral bleeding. Based on these findings, we made the diagnosis of gross hematuria caused by nutcracker syndrome (NCS). We concluded that the main cause of the anemia and proteinuria in our patient was leakage of blood and this is confirmed by the relationship of red blood cells to protein in the urine because we proved whole blood and plasma protein loss in the urine by calculation. Fourteen months after discharge, both the gross hematuria and proteinuria spontaneously disappeared. This case strongly suggested that the first therapy for hematuria and proteinuria with NCS should be observation.

Comparison of Endovascular and Surgical Treatment for Ruptured Cerebral Aneurysms with respect to Short and Long-Term Outcome

SUMMARY

We compared the treatment for ruptured aneurysms from the clinical and radiological follow-ups after endovascular (GDC) or surgical treatment. There were 142 surgically treated cases and 38 endovascular treated cases from May 1997 to December 2001. In endovascular cases there were four A-com, four MCA, 12 ICA and 18 posterior circulation aneurysms. In surgical cases, there were 53 A-com ACA, 51 MCA, 36 ICA and two posterior circulation aneurysms. The clinical outcomes of endovascular and surgical treatments were correlated with the H & H grades before treatments. At short stage, 71% of endovascular and 78.2% of surgical cases showed a favorable outcome (GOS GR or MD) (p=0.3). Long-term clinical follow ups (14.5 to 58 months) showed 77.7% of endovascular and 87.7% of surgical cases resulted in GR or MD (p=0.17). In endovascular cases, 22.2% showed recurrence during the follow-up period and five of them needed re-treatment. We experienced failed endovascular approach at acute stage in seven cases which changed to surgery. In conclusion, the short and long term clinical results of endovascular treatment were acceptable comparing surgical clipping. High recurrence rate after GDC treatment did not permit future completeness of the treatment. Still the treatment alternative between endovascular or surgical treatment may change depending on the criteria of each institution, attention should be paid to the disadvantages of endovascular treatment as the first choice for ruptured aneurysms.

Which cartilage is regenerated, hyaline cartilage or fibrocartilage? Non-invasive ultrasonic evaluation of tissue-engineered cartilage

OBJECTIVE

To investigate ultrasonic evaluation methods for detecting whether the repair tissue is hyaline cartilage or fibrocartilage in new cartilage regeneration therapy.

METHODS

We examined four experimental rabbit models: a spontaneous repair model (group S), a large cartilage defect model (group L), a periosteal graft model (group P) and a tissue-engineered cartilage regeneration model (group T). From the resulting ultrasonic evaluation, we used %MM (the maximum magnitude of the measurement area divided by that of the intact cartilage) as a quantitative index of cartilage regeneration. The results of the ultrasonic evaluation were compared with the histological findings and histological score.

RESULTS

The %MM values were 61.1 +/- 16.5% in group S, 29.8 +/- 15.1% in group L, 36.3 +/- 18.3% in group P and 76.5 +/- 18.7% in group T. The results showed a strong similarity to the histological scoring.

CONCLUSION

The ultrasonic examination showed that all the hyaline-like cartilage in groups S and T had a high %MM (more than 60%). Therefore, we could define the borderline between the two types of regenerated cartilage by the %MM.

Computer simulation of flow dynamics in an intracranial aneurysm. Effects of vessel wall pulsation on a case of ophthalmic aneurysm

SUMMARY

Using a supercomputer, the authors studied the effect of vessel wall pulsation on flow dynamics with a three-dimensional model simulating both a rigid and pulsatile style. The design of the aneurysm models was set with a 5 mm dome diameter and a 1 or 3 mm orifice size to simulate a carotid-ophthalmic aneurysm. Flow dynamics were analyzed according to flow pattern, wall pressure and wall shear stress. The flow pattern in the aneurysm sac showed the great difference between rigid and pulsatile models particularly in the small-neck aneurysm model. The arterial wall tended to be exposed to a higher pressure peak in the pulsatile model than in the rigid one, especially at its bifurcation and curved regions. Sites of shear stress peak were found on the aneurysmal dome as well as at the distal end of the orifice in both rigid and pulsatile models. The effects of vessel-wall pulsation should be considered whenever evaluating conditions in and around an aneurysm.

Nagoya university training system for neuroendovascular therapists

SUMMARY

It is very important to train more neuroendovascular therapists (NETists) in response to Japan's growing social needs. Since the supply of qualified NETists is still insufficient to cover Japanese institutions, therefore some emergency cases with indications for endovascular therapy may be overlooked, untreated or treated by other methods resulting in unfavorable outcomes. Thus, neuroendovascular therapies are situated as one of the important tratment modalities for neurosurgical diseases (1,2). We studied our present states of the endovascular neurosurgery and introduce our training system.

Can ultrasound predict histological findings in regenerated cartilage?

OBJECTIVE

To evaluate regenerated articular cartilage quantitatively by introducing an ultrasonic probe into the knee joint under arthroscopy and analysing the A-mode echogram by means of wavelet transformation.

METHODS

Three experimental rabbit models (spontaneous repair model, large cartilage defect model, treatment model) were examined using our ultrasonic evaluation system and a histological grading scale. From resulting wavelet map, the percentage of maximum magnitude was selected as the quantitative index of the ultrasonic evaluation system.

RESULTS

The percentage maximum magnitude in the spontaneous repair model was 61.1%, that in the large defect model was 29.8% and that in the treatment model was 36.3%. There was modest correlation between the percentage maximum magnitude and the histological grading scale (r = -0.594)

CONCLUSION

Our findings indicate that ultrasound analysis can predict the microstructure of regenerated cartilage.

Mutation of the p53 gene predicts lymph node metastases in Japanese patients with esophageal carcinoma: DNA and immunohistochemical analyses

We evaluated the clinicopathologic significance of p53 gene mutations, including a comparison of DNA analysis and immunohistochemical examination, in Japanese patients with esophageal squamous cell carcinoma, a highly aggressive cancer. Genomic DNA isolated from 76 tumors without preoperative treatment was subjected to polymerase chain reaction and sequencing. Associations were sought between p53 mutations and clinicopathologic characteristics. Cases also were investigated immunohistochemically to detect abnormal p53 protein accumulation. Overexpression of p53 protein occurred in 51 cases (67.1%), while gene mutations in the examined exons were found in only 14 (18.4%). By multivariate analysis, p53 mutation predicted detection of eight or more lymph node metastases. Mutations of the p53 gene may not only participate in the initiation of esophageal cancer, but also may promote lymph node metastasis. Unlike gene mutations, p53 protein overexpression did not predict nodal metastasis extent.

Multivariate analysis of risk factors for hemorrhagic cystitis after hematopoietic stem cell transplantation

To establish the most appropriate prophylactic therapy and risk factors for predicting hemorrhagic cystitis (HC) after stem cell transplantation (SCT), we retrospectively analyzed the clinical records of 450 transplant patients treated from 1982 to 2002. In all, 81 patients developed early- and/or late-onset HC (early=29, late=48, both=4). For the incidence of early-onset HC, administration of cyclophosphamide (CY) (p=0.0079, odds ratio (OD)=5.109, 95% confidence interval (CI)=1.533-17.030), busulfan (BU) (p=0.0015, OD=3.336, 95% CI=1.584-7.027), BU+CY (p=0.0001, OD=4.369, 95% CI=2.055-9.292), antithymocyte globulin (p=0.0009, OD=3.368, 95% CI=1.642-6.911), nonradiation (p=0.0163, OD=2.564, 95% CI=0.181-0.841), 2-mercaptoethane sodium sulfonate (Mesna) (p=0.0001, OD=7.519, 95% CI=2.847-19.858), and bladder irrigation (p=0.0001, OD=4.950, 95% CI=2.328-10.523) were risk factors. By Fisher's exact test, the combination of BU and Mesna was a more significant risk factor (P<0.001) than Mesna alone (p=0.008) compared to the administration of neither agent. By multivariate analysis, prophylactic administration of Mesna (p=0.0105, OD=5.301, 95% CI=1.477-19.026) and bladder irrigation (p=0.0001, OD=9.469, 95% CI=3.872-23.156) were significant risk factors of early-onset HC. We conclude that (i). high-dose BU as well as CY is a cause of HC, (ii). protective bladder irrigation has an opposite effect, and (iii). Mesna possibly has a toxic effect on bladder mucosa.

[Redo coronary artery bypass operation under beating heart via the left thoracotomy reusing patent grafts]

We report three cases of successful redo coronary artery bypass grafting (CABG) under beating heart via left thoracotomy with recycling of patent grafts previously implanted. Case 1 and 2: Anginal attack relapsed due to occlusion of the proximal portions of saphenous vein grafts (SVG) that had been sequentially anastomosed to the left coronary artery branches. In each case, the distal portion of the SVG was patent and functioned as coronary-coronary bypass. The left internal thoracic artery graft (ITAG) anastomosed to the left anterior descending coronary artery (LAD) was patent. Each patient underwent off-pump CABG through a left posterolateral thoracotomy. CABG was performed with the radial artery to the circumflex coronary artery (case 1) or the circumflex coronary artery and previous SVG (case 2). The proximal ends of radial artery grafts were anastomosed to the descending aorta. Case 3: Simultaneous reoperative CABG and the operation for the pseudoaneurysm that developed after the abdominal aortic graft replacement were performed. Bypass grafting between ITAG and LAD was performed with SVG via a left anterolateral thoracotomy because of severe anastomotic stricture of ITAG-LAD. The postoperative courses was uneventful for all patients.