The influence of vascular pressure and angiographic characteristics on haemorrhage from arteriovenous malformations

BACKGROUND

The present study was designed to determine whether there is a physiological explanation for the predisposition of patients with certain angiographic characteristics to haemorrhage from cerebral arteriovenous malformations (AVMs).

METHODS

Intra-operative measurement of feeding artery pressure (FAP) and intravascular pressures in the draining venous system [draining vein pressure (DVP) and cranial sinus pressure (SP)] were performed for 30 AVM cases using direct puncture of the vessels. The correlation between pressures and previously described angiographic characteristics predisposing to haemorrhage were evaluated.

FINDINGS

Small nidus size and only one draining vein increased the risk of haemorrhage. FAP and DVP are both inversely related to the number of draining veins and the size of the AVMs. DVP was significantly higher in AVMs with haemorrhage (23.1+/-8.7 mmHg) than in those without (13.5+/-4.4), as was FAP (58.6+/-12.8 as opposed to 38.7+/-4. 7) (p<0.05). Moreover, the difference between systemic blood pressure and the FAP with haemorrhagic AVMs (17.0+/-9.5 mmHg) was significantly lower than that in nonhaemorrhagic cases (33.7+/-5.5) (p<0.05). The pressure difference between the feeding artery and draining vein was not significant between the haemorrhagic and nonhaemorrhagic groups. There was no significant difference of SP between haemorrhagic and nonhaemorrhagic patients.

INTERPRETATION

The present study suggests that a high DVP probably induced by high resistance in the venous drainage system, as well as a high FAP, may contribute to the development of haemorrhage from AVMs, and physiologically supports previous reports that small AVMs and AVMs with only one draining vein are susceptible to haemorrhage.

Clinicopathological study of intracranial fusiform and dolichoectatic aneurysms : insight on the mechanism of growth

BACKGROUND AND PURPOSE

Intracranial fusiform aneurysms can be divided into 2 clinically different subtypes: acute dissecting aneurysms and chronic fusiform or dolichoectatic aneurysms. Of these 2, the natural history and growth mechanism of chronic fusiform aneurysms remains unknown.

METHODS

A consecutive series of 16 patients with chronic fusiform aneurysms was studied retrospectively to clarify patient clinical and neuroradiological features. Aneurysm tissues were obtained from 8 cases and were examined to identify histological features that could correspond to the radiological findings.

RESULTS

Four histological features were found: (1) fragmentation of internal elastic lamina (IEL), (2) neoangiogenesis within the thickened intima, (3) intramural hemorrhage (IMH) and thrombus formation, and (4) repetitive intramural hemorrhages from the newly formed vessels within thrombus. IEL fragmentation was found in all cases, which suggests that this change may be one of the earliest processes of aneurysm formation. MRI or CT detected IMH, and marked contrast enhancement of the inside of the aneurysm wall (CEI) on MRI corresponded well with intimal thickening. Eight of 9 symptomatic cases but none of 7 asymptomatic cases presented with both radiological features.

CONCLUSIONS

Data suggest that chronic fusiform aneurysms are progressive lesions that start with IEL fragmentation. Formation of IMH seems to be a critical event necessary for lesions to become symptomatic and progress, and this can be monitored on MRI. Knowledge of this possible mechanism of progression and corresponding MRI characteristics could help determine timing of surgical intervention.

Ten years' experience of aortic aneurysm associated with systemic lupus erythematosus

BACKGROUND

aortic aneurysm is a rare but life-threatening cardiovascular complication in patients with systemic lupus erythematosus (SLE). The purpose of this study was to clarify the characteristic clinical features and the pathological mechanism of aneurysmal formation in these patients.

METHODS

among 429 patients operated on for abdominal aortic aneurysm (AAA) during the past 10 years, five cases with SLE were treated surgically. Their clinical data were reviewed, and the resected aneurysmal wall of the five patients was also examined histologically.

RESULTS

the mean age of the patients with SLE was 55 years, which was statistically younger than that of the other patients (mean 77 years, s.d. 7.9, p <0.05). They had received long-term corticosteroid therapy for the treatment of SLE for a mean of 23 years. Histologically, destruction of the medial elastic lamina was characteristic. Four patients had no complications in the postoperative follow-up period (mean 4 years), while the remaining patient died of rupture of a dissecting aneurysm two years after operation.

CONCLUSION

prolonged steroid therapy may play a major role in accelerating atherosclerosis, which can result in aortic aneurysmal enlargement, possibly together with primary aortic wall involvement and/or vasculitic damage in patients with SLE.

A simple HPLC-fluorescence method for the measurement of R,S-sotalol in the plasma of patients with life-threatening cardiac arrhythmias

R,S-sotalol, a ss-blocker drug with class III antiarrhythmic properties, is prescribed to patients with ventricular, atrial and supraventricular arrhythmias. A simple and sensitive method based on HPLC-fluorescence is described for the quantification of R,S-sotalol racemate in 500 microl of plasma. R,S-sotalol and its internal standard (atenolol) were eluted after 5.9 and 8.5 min, respectively, from a 4-micron C18 reverse-phase column using a mobile phase consisting of 80 mM KH2PO4, pH 4.6, and acetonitrile (95:5, v/v) at a flow rate of 0.5 ml/min with detection at lambdaex = 235 nm and lambdaem = 310 nm, respectively. This method, validated on the basis of R,S-sotalol measurements in spiked blank plasma, presented 20 ng/ml sensitivity, 20-10,000 ng/ml linearity, and 2.9 and 4.8% intra- and interassay precision, respectively. Plasma sotalol concentrations were determined by applying this method to investigate five high-risk patients with atrial fibrillation admitted to the Emergency Service of the Medical School Hospital, who received sotalol, 160 mg po, as loading dose. Blood samples were collected from a peripheral vein at zero, 0.5, 1.0, 1.5, 2.0, 3.0, 4. 0, 6.0, 8.0, 12.0 and 24.0 h after drug administration. A two-compartment open model was applied. Data obtained, expressed as mean, were: C MAX = 1230 ng/ml, T MAX = 1.8 h, AUC T = 10645 ng h-1 ml-1, Kab = 1.23 h-1, alpha = 0.95 h-1, ss = 0.09 h-1, t((1/2))ss = 7.8 h, ClT/F = 3.94 ml min-1 kg-1, and Vd/F = 2.53 l/kg. A good systemic availability and a fast absorption were obtained. Drug distribution was reduced to the same extent in terms of total body clearance when patients and healthy volunteers were compared, and consequently elimination half-life remained unchanged. Thus, the method described in the present study is useful for therapeutic drug monitoring purposes, pharmacokinetic investigation and pharmacokinetic-pharmacodynamic sotalol studies in patients with tachyarrhythmias.

Thromboangiitis obliterans: classic and new morphological features

The clinical and pathological concept of thromboangiitis obliterans (TAO, Buerger's disease) is still controversial. While the clinical criteria of TAO are relatively well defined, the etiology is unknown and its diagnosis based on pathology is confusing, since there is no consensus on the precise pathological criteria for TAO. To investigate the morphological features that differentiate TAO from arteriosclerosis obliterans (ASO) or thromboembolism, and to clarify the morphological independence of TAO, we studied 94 amputated specimens of lower extremities, including 31 specimens from patients with a clinical diagnosis of TAO and 31 autopsy specimens as control cases. It was revealed that most of the classic morphological features described by Buerger and others are not helpful when considered independently in the differential diagnosis, except for intact internal elastic lamina. In addition, findings of intimal inflammation, intact media and absence of medial calcification were demonstrated to be common in both TAO and thromboembolism. Statistical analysis in the present study, the most comprehensive thus far, showed that novel findings of onion-like-shaped recanalizing vessels in the occluded arteries, adventitial fibrosis without medial fibrosis, swelling of the endothelium of the vasa vasorum and edema beneath the external elastic lamina were characteristic of TAO and would be helpful in a differential diagnosis. When a combination of these morphological features is present, diagnosis of a presumed overlap of TAO and ASO in the same site of the vessel concerned is possible. Furthermore, comparison of statistical evaluations based on morphological features performed in various diagnostic groups implies that the clinical diagnosis of TAO is currently underestimated because the results of the analysis of morphological features of specimens in which TAO was suspected or specimens selected on the basis of a broad and nonspecific definition of TAO were surprisingly similar to the results in strictly defined TAO cases. Our findings suggest that injury and regeneration of minute vessels such as recanalizing vessels and vasa vasorum play a part in the pathogenesis of TAO.

Purification, molecular cloning, and genomic organization of human brain long-chain acyl-CoA hydrolase

An acyl-CoA hydrolase, referred to as hBACH, was purified from human brain cytosol. The enzyme had a molecular mass of 100 kDa and 43-kDa subunits, and was highly active with long-chain acyl-CoAs, e.g. a maximal velocity of 295 micromol/min/mg and K(m) of 6.4 microM for palmitoyl-CoA. Acyl-CoAs with carbon chain lengths of C(8-18) were also good substrates. In human brain cytosol, 85% of palmitoyl-CoA hydrolase activity was titrated by an anti-BACH antibody, which accounted for over 75% of the enzyme activity found in the brain tissue. The cDNA isolated for hBACH, when expressed in Escherichia coli, directed the expression of palmitoyl-CoA hydrolase activity and a 44-kDa protein immunoreactive to the anti-BACH antibody, which in turn neutralized the hydrolase activity. The hBACH cDNA encoded a 338-amino acid sequence which was 95% identical to that of a rat homolog. The hBACH gene spanned about 130 kb and comprised 9 exons, and was mapped to 1p36.2 on the cytogenetic ideogram. These findings indicate that the long-chain acyl-CoA hydrolase present in the brain is well conserved between man and the rat, suggesting a conserved role for this enzyme in the mammalian brain, and enabling genetic studies on the functional analysis of acyl-CoA hydrolase.

Aortic valve replacement with the Nicks annulus enlargement procedure 12 years after mitral valve replacement

An aortic valve replacement was successfully performed employing the Nicks annulus enlargement procedure in a case of aortic valve stenosis with small annulus 12 years after mitral valve replacement. Previous mitral valve replacement does not preclude feasibility of the Nicks procedure.

Spontaneous carotid cavernous fistulas with special reference to the influence of estradiol decrease

The etiology of the dural arteriovenous fistula (AVF) involving the cavernous sinus is still unknown. However, it is of interest that this condition usually occurs in post-menopausal women. The purpose of the present study was therefore to clarify the relationship between sex hormone blood levels and the occurrence of dural AVFs in the cavernous sinus. Serum sex hormone levels and factors associated with atherosclerosis were examined in 26 consecutive patients with dural AVF involving the cavernous sinus presenting at our institute during the last eight years and compared with those of a post-menopause control group. Of the present patient series, 21 (81%) were women. All except five had passed menopause. Five (24%) of the women patients presented with symptoms consistent with cessation of menstruation, namely, a blood level of estradiol significantly lower than the control value. Hypertension was recognized in 10 (71%) of 14 females who had experienced menopause 10 or more years previously and in all male patients. A sudden abnormal decrease of blood estradiol levels in female patients demonstrating symptoms consistent with menopause may thus be an important precipitating factor in the occurrence of dural AVFs involving the cavernous sinus. Hypertension, in older female and male patients, with or without longstanding low blood estradiol levels, may cause atherosclerosis of the feeding vessels in the dura mater, resulting in the opening of a normal AV shunt to provide collateral circulation.

Hyperfunctioning intrathyroid parathyroid adenoma: report of two cases

We report herein two cases of intrathyroid parathyroid adenoma, which is a rare condition in patients with hyperparathyroidism. In the first patient, an excised intrathyroid nodule was diagnosed to be parathyroid adenoma postoperatively. In the second patient, preoperative localization studies suggested the possibility of an intrathyroid adenoma. When a pathological gland is not found during surgery for primary hyperparathyroidism, an ectopic parathyroid gland including an intrathyroid adenoma should thus be considered.

A novel sesterterpenoid, nitiol, as a potent enhancer of IL-2 gene expression in a human T cell line, from the Peruvian folk medicine "Hercumpuri" (Gentianella nitida)

A novel sesterterpenoid designated as nitiol (1), possessing enhancement activity of IL-2 gene expression in a human T cell line, was isolated from the Peruvian folk medicine "Hercampuri" (Gentianella nitida). The structure was elucidated by extensive spectroscopic investigation.

Cytopathological observations in a 27-year-old female patient with endometrioid adenocarcinoma arising in the lower uterine segment of the uterus

The determination of the malignancy of an endometrioid adenocarcinoma arising in the lower uterine segment (LUS) is difficult because of the high degree of differentiation of adenocarcinoma. The cytopathological and immunohistochemical features of endometrioid adenocarcinoma arising in the LUS of a young adult female are presented. The preoperative cytopathological examination of a 27-yr-old female could not enable an accurate diagnosis of malignancy. Hysterectomy specimens revealed the presence of an endometrioid-type adenocarcinoma with minimal atypia and myometrial invasion, which was located in the LUS. This tumor was consistent with a histological diagnosis of endometrioid minimal-deviation adenocarcinoma (MDA). Immunohistochemically, the tumor's glands were p53-, proliferating cell nuclear antigen-, and carcinoembryonic antigen-positive, and estrogen receptor-, progesterone receptor-,and vimentin-negative. The cytological and surgical specimens showed a remarkable association of squamous metaplasia. Although cytopathological difficulties in determining malignancy of MDA endometrioid adenocarcinoma arising in the LUS are well-known, the following features worth noting include: 1) squamous metaplasia on cytological and histological slides; 2) epithelial cells incorporating polymorphic nuclear neutrophils on cytological slides; and 3) positive immunohistochemistry of p53 protein. Diagn. Cytopathol. 1999;21:117-121.

p53 mutations in tumor and non-tumor tissues of thorotrast recipients: a model for cellular selection during radiation carcinogenesis in the liver

Concerns over cancer development from exposure to environmental sources of densely ionizing, high linear energy transfer (LET) radiation, such as alpha-particles from radon, is a current public health issue. The study of tumors attributable to high LET irradiation would greatly augment our insights into the biological mechanisms of carcinogenesis. Chronic low-dose-rate internal exposure to alpha-radiation from thorium dioxide deposits following intravascular administration of the radiographic contrast agent Thorotrast is known to markedly increase the risk of cancer development, especially that of hepatic angiosarcomas and cholangiocarcinomas. Although the mechanism is hypothesized to be via cellular damage, DNA being a major target, wrought by the high LET alpha-particles, the specific genes and the actual sequence of events involved in the process of transforming a normal cell into a malignant one are largely unknown. To shed some light on the molecular mechanisms of cancer development during a lifetime exposure to alpha-radiation, we analyzed the most commonly affected tumor suppressor gene in humans, p53, in 20 Thorotrast recipients who developed cancer, mostly of hepatic bile duct and blood vessel origin. Of the 20 cases, 19 were found to harbor p53 point mutations. Moreover, the accompanying non-tumor tissues from these patients also had p53 mutations, albeit at lower frequency. The distribution pattern of the point mutations was significantly different between the non-tumor and tumor tissues, with most mutations in malignant tissues located in the highly conserved domains of the p53 gene. Our results support the idea that p53 mutations are important in the genesis of Thorotrast-induced tumors but that these point mutations are a secondary outcome of genomic instability induced by the irradiation. Additionally, non-tumor cells harboring p53 mutations may gain some survival advantage in situ but mutations in the domains responsible for the formation of structural elements critical in binding DNA may be necessary for a cell to reach full malignancy.

The factors influencing haematoma volume due to arteriovenous malformations

Haemorrhage due to cerebral arteriovenous malformations (AVMs) varies from massive, requiring urgent operations, to clinically silent. The present study was designated to identify factors influencing haematoma size, and the pathophysiological mechanisms of massive haemorrhage were studied. 55 patients with intracerebral haematomas due to supratentorial AVMs were included in this study. Angiographic and clinical findings were retrospectively evaluated in relation to haematoma size. Statistical analysis demonstrated that small size and the presence of only one draining vein were high risk factors for massive haemorrhage. The haematoma volume in small AVMs (30 +/- 4 cm3) was significantly larger than in other AVMs (7 +/- 3 cm3) (p = 0.0005). AVMs with only one draining vein were associated with massive haematoma volume as compared to AVMs with two or more draining veins (30 +/- 4 versus 11 +/- 3 cm3, p = 0.0023). Our previous study demonstrated that feeding artery pressure (FAP) was significantly higher in AVMs with haemorrhage than in those without, as was draining vein pressure (DVP), and FAP and DVP were inversely related to the number of draining veins and the size of the AVMs. Thus, in small AVMs and AVMs with only one draining vein, local increase in DVP may thus contribute to massive haemorrhage.

Tissue response of a small saccular aneurysm after incomplete occlusion with a Guglielmi detachable coil

A 49-year-old woman had a small saccular aneurysm that was incompletely occluded with a Guglielmi detachable coil (GDC). She died from rupture of another aneurysm 42 days after the treatment. Autopsy for the embolized aneurysm revealed no neoendothelium at the aneurysmal neck, but an organized thrombus was observed limited to the periphery of the aneurysmal lumen. Although isolation of the aneurysm was not apparent, loose embolization with this method may help to reinforce the aneurysmal wall.

Efficacy of the stump pressure ratio as a guide to the safety of permanent occlusion of the internal carotid artery

To determine whether the absolute value for the stump pressure might be a useful index of symmetrical cerebral blood flow (CBF), and to examine correlations with the stump pressure ratio (initial mean stump pressure/preocclusion mean arterial pressure), fifty candidates for ICA injury or permanent occlusion were evaluated preoperatively. Each was continuously monitored for mean stump pressure and arterial pressure before, during (for a total of 20 min), and after balloon test occlusion. During the occlusion, CBF was measured by 99 m Tc-hexamethyl-propyleneamine oxime (99 m Tc-HMPAO) single photon emission computed tomography (SPECT). The stump pressure and the stump pressure ratio were then compared with the results of 99 m Tc-HMPAO SPECT. Patients who failed to tolerate even brief periods of carotid occlusion and showed asymmetric decreases in CBF on SPECT were divided into high and moderate risk groups. Those with no significant changes in CBF on the occluded site formed the minimum risk group. Mean stump pressure was over 50 mmHg in 10 of a total of 25 patients in the high and moderate risk groups, and below 50 mmHg in 5 of the 25 patients in the minimum risk group. The stump pressure ratio did not exceed 56% in any but two patients in the high and moderate risk groups, and values were at least 60% in all patients of the minimum risk group. Decrease of CBF in two moderate risk group cases was localized in the posterior circulation. Difference in symmetrical CBF between the stump pressure ratio vs. the absolute value of mean stump pressure were statistically significant (p < 0.01, Fisher's Exact Test). Maintenance of a stump pressure ratio of 60% or more during test occlusion may be a more useful index for a good collateral circulation than any absolute value for mean stump pressure.

The efficacy of endovascular surgery for treatment of giant aneurysms with special reference to coil embolization for endosaccular occlusion

SUMMARY

We assessed the long-term follow-up results of platinum coil embolization and aneurysmography (ARG) with endovascular surgery for giant aneurysms. 24 cases of giant aneurysms were treated over a period of seven years. In the present study, the 16 of these for which surgical clipping was impossible so that only endovascular surgery was employed were investigated in detail. In 10 cases the cavernous sinus area was involved, in two each the tip of the basilar artery, and the bifurcation of the ophthalmic artery, and in one each the extracranial internal carotid and the vertebral artery. Since conventional angiography did not allow the position and size of the neck of 10 cavernous sinus aneurysms to be identified, making treatment decisions difficult, we applied the ARG developed by the senior author. Prior to treatment, balloon test occlusion of the parent arteries was performed. In all 10 cavernous sinus cases, ARG successfully revealed the morphology of the aneurysm. A small neck was diagnosed for seven of the aneurysms of the cavernous sinus and all those located at the basilar and ophthalmic arteries, making a total of 11, and for these endosaccular embolization was carried out. In the other 5 cases, proximal occlusion using Gold valve balloons was performed. Under ARG, embolization of the aneurysms could be safely accomplished with platinum coils, without dislocation of the coils into the parent arteries in all cases. In four out of 10 cases, re-opening of the aneurysms occurred after 2 months or longer, so that re-embolization was required. Regarding complications, transient monoparesis of the upper extremity was encountered in one case. After angiographic and MRA follow-up of 1-36 months (average, 13.8 months), 4 of 10 cases demonstrated complete occlusion, and 5 displayed an 80-90% reduction in blood flow. In only one case, involving a basilar tip aneurysm, was the treatment unsuccessful in preventing eventual rupture and death. In cases where the morphology of the aneurysm is unclear, ARG can be considered indispensable for determining the treatment modality and safe performance of localized embolization of the neck by endovascular surgery. However, since coils used for embolization of giant aneurysms may move or become compacted, re-opening can occur so that applications may be limited, especially with terminal type lesions with intraluminal thrombus, and the necessity for long-term follow-up must be emphasized.

Preoperative superselective embolization of skull-base meningiomas: indications and limitations

We evaluated the clinical significance of preoperative superselective embolization for skull-base meningiomas. The subjects consisted of 20 patients with skull-base meningiomas, and were classified into a preoperative embolized group and a non-embolized group. The volume of blood transfused during the operation, the length of the operative procedure and the neurological outcome were compared between the two groups. The results showed that, in tumors smaller than 6 cm, the blood lost during the operation was significantly less in the embolized group. In tumors larger than 6 cm, there was not difference in blood lost, perhaps because larger meningiomas tend to have tiny blood vessels that are unsuitable for preoperative embolization. There was no difference in the length of the operation between the two groups. The embolized group tended to show a better clinical outcome than the non-embolized group.

Dural-pial arteriovenous malformation after sinus thrombosis

BACKGROUND

We report an unusual case of acquired dural-pial arteriovenous malformation (AVM) following sinus thrombosis.

CASE DESCRIPTION

Initial angiography performed in a 39-year-old man showed thrombosis of the superior sagittal sinus (SSS) and the right transverse sinus (TS) but no vascular malformations. Follow-up angiography 29 months later revealed recanalization of the SSS and the TS, retrograde cortical venous drainage which suggested that thrombosis of the sinuses probably propagated into the adjacent parietal cortical veins, and development of a dural-pial AVM at or near the site of thrombi in more than one cortical vein. Complete surgical excision of the lesion was accomplished without neurological deterioration.

CONCLUSIONS

The present case suggests the possibility that the pial AVM is not only a congenital condition but also may develop as an acquired lesion.

The value of long-term clinical follow-up for cases of spontaneous carotid cavernous fistula

To clarify the value of clinical long-term follow-up with radiological examination, ranging from 12 to 63 months (average: 35 months), 18 consecutive patients suffering from spontaneous carotid cavernous fistula (CCF), were studied prospectively. Five aged patients without aggressive symptoms were treated conservatively, and the other 13 underwent transarterial embolization. The radiological follow-up was primarily by magnetic resonance angiography (MRA), performed from 2 to 6 times (average: 4.1 times) during the follow-up period. In three cases, CCFs persisted, but the other fifteen (83%) demonstrated complete cure as defined by long-term follow-up MRA. The three patients with persistent CCFs were comparatively young, less than 60 years old, had no atherosclerotic factors and demonstrated multiple venous drainage routes with cortical venous drainage on angiography. In two of them, the symptoms completely disappeared, and the other had only mild chemosis. However, surprisingly, in two, MRA revealed residual CCF with drainage into only cortical veins through the sphenoparietal sinus, this radiological finding being well known to signify danger. During the follow-up period, central retinal vein thrombosis occurred in two cases. The common point in these cases was that the superior ophthalmic vein was the only venous drainage route. This is also a point requiring care. We therefore emphasize the importance of careful long-term radiological follow-up for spontaneous CCF patients even when their symptoms improve or disappear. MRA is particularly suitable for this purpose and applicable in the out-patient clinic because of its non-invasive nature.

The significance of retrograde thrombosis following removal of arteriovenous malformations in elderly patients

BACKGROUND

Retrograde thrombosis of former feeding arteries should be considered as a distinct postoperative complication following surgery for arteriovenous malformation (AVM). Regardless of the presence of AVMs, the cerebral arteries undergo atherosclerotic changes with advancing age. In the present study, three cases in elderly patients who developed retrograde thrombosis are reported, and the effect of the patient's age on this complication is discussed.

CLINICAL MATERIALS AND METHODS

The present study group consisted of 158 patients who underwent AVM resection and postoperative angiographic studies. Five patients were 65 years of age or older (elderly group) at the time of operation, 108 were between 20 and 64 years of age (adult group), and 45 were less than 20 years of age (young group). The incidence of retrograde thrombosis in the elderly group was compared with that of the other two groups.

RESULTS

We found that surgery in the elderly group was accompanied by a significantly higher incidence of retrograde thrombosis (60%) than in the adult group (4%), or the young group (0%).

CONCLUSIONS

The present study suggests that this complication should be considered as a serious possibility following removal of an AVM, especially in elderly patients.

Multiple, unique, and common p53 mutations in a thorotrast recipient with four primary cancers

Four primary cancers found at autopsy of a patient who received the thorium-based contrast agent Thorotrast 50 years ago and who was healthy up until a few months before his death from liver failure were analyzed for p53 mutations. The data suggest that the chronic alpha-irradiation may be a large causative factor. Multiple mutations were found in all the cancer tissues: two foci of a cholangiocellular carcinoma, a tubular adenocarcinoma of the stomach, a squamous cell carcinoma of the lung, and an adenocarcinoma of Vater's ampulla. The total number of point mutations detected were 13. Moreover, homozygous aberrations were detected in a large area of normal small intestine and noncancer liver tissues suggesting that nontumor cells which harbored p53 abnormalities gained a survival advantage and clonally expanded.

Pial arteriovenous malformation with massive perinidal edema

It is generally considered that perinidal edema in an arteriovenous malformation (AVM) is caused by a concomitant intracerebral hematoma. We report a rare case of AVM with perinidal massive edema which was possibly not due to hemorrhage, and discuss the pathophysiological mechanisms of such edema development. A 60-year-old woman presented with a sudden onset severe headache. Computed tomography (CT) scans obtained two hours after the onset showed an AVM-like lesion with a small hematoma in the right parieto-occipital lobe, and unexpectedly early development of massive edema adjacent to the hematoma. Angiograms demonstrated a medium-sized AVM, and severe stenosis in the draining vein which suggested the presence of venous hypertension at prestenotic sites. Repeated CT scans and magnetic resonance (MR) images in the chronic period after the hemorrhage demonstrated persistence of the perinidal edema with mass effect. Removal of the lesion was achieved 2 months after the onset. MR images 3 months after the operation showed marked reduction of perinidal edema. The time course of the perinidal edema suggests that its development was unrelated to the hemorrhage. The findings indicate that increased venous pressure secondary to severe stenosis of the draining vein may possibly contribute to the development of perinidal edema.

Gain-of-function mutations of c-kit in human gastrointestinal stromal tumors

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors in the human digestive tract, but their molecular etiology and cellular origin are unknown. Sequencing of c-kit complementary DNA, which encodes a proto-oncogenic receptor tyrosine kinase (KIT), from five GISTs revealed mutations in the region between the transmembrane and tyrosine kinase domains. All of the corresponding mutant KIT proteins were constitutively activated without the KIT ligand, stem cell factor (SCF). Stable transfection of the mutant c-kit complementary DNAs induced malignant transformation of Ba/F3 murine lymphoid cells, suggesting that the mutations contribute to tumor development. GISTs may originate from the interstitial cells of Cajal (ICCs) because the development of ICCs is dependent on the SCF-KIT interaction and because, like GISTs, these cells express both KIT and CD34.

Mass effect caused by clinically unruptured cerebral arteriovenous malformations

OBJECTIVE

It is generally considered that mass effect caused by arteriovenous malformations (AVMs) is evidence of ruptures. In the present study, the incidence of mass effect in clinically unruptured AVMs was evaluated, and the underlying causative factors and pathophysiological mechanisms were studied.

METHODS

Twenty-seven patients with clinically unruptured supratentorial pial AVMs were examined. The majority were suffering from epilepsy, and frontal lobe involvement was revealed in approximately half of the patients. Angiographic studies, computed tomographic scans, and magnetic resonance images were obtained for all patients. Twenty-one patients underwent removal of AVMs. In 10 of the surgically treated patients, intraoperative vascular pressure measurements were obtained before removal of the AVMs.

RESULTS

Mass effect was detected in 12 (44%) of the 27 patients. Cortical sulci obliteration (eight patients) and lateral ventricle displacement (seven patients) were frequently noted. The volume of AVMs was significantly larger in patients with mass effect than in those without mass effect (P < 0.001). Large dilated venous sacs or ectatic veins were observed to be associated with mass effect (P < 0.001). In only one patient was gross displacement related to a surrounding massive brain edema. Draining vein pressure in patients with mass effect was significantly elevated as compared to the average value in patients without mass effect (22 +/- 5 versus 12 +/- 3 mm Hg) (P < 0.01).

CONCLUSION

The present study suggests that mass effect is not infrequent in clinically unruptured AVMs. Furthermore, multiple causative factors were detected, including the large size of AVMs, marked draining vein dilatation, and brain edema around the AVMs. Findings also indicated that a pathophysiologically high pressure in the venous drainage system may contribute to mass effect.

[Proliferating character of inverted papilloma of the urinary bladder]

BACKGROUND

Inverted papilloma (IP) of the urinary bladder is generally considered to be a benign lesion by histological examination. In recent years, however, there have been several cases of IP simultaneously accompanied with transitional cell carcinoma (TCC), elsewhere in the bladder or combined as a single urothelial lesion. So we investigated proliferating character of IP by DNA ploidy analysis and immunohistostaining with proliferating cell nuclear antigen (PCNA).

METHODS

Six cases of IP of the urinary bladder were analyzed and 12 cases of TCC of G1 and G3 grade were included in this study as a control. As DNA ploidy analysis, all specimens were feulgen stained using CAS DNA staining kit and examined by image cytometry (CAS 200R system). For the PCNA immunohistochemistry, all specimens were stained with anti-PCNA monoclonal antibody (Novocastra Lab.: PC10) according to ABC (avidin-biotin-complex) standard method. We determined that the DNA Index of the case under 1.20 was diploid and the others was aneuploid. PCNA staining were determined by only one pathologist as follows: negative (-) and positive (+), (2+) and (3+).

RESULTS

As DNA ploidy, 5 of 6 cases of TCC G3 group as a control were aneuploid. But in spite of all cases of TCC G1 group were diploid, among IP cases, only 1 out of 6 was aneuploid. As PCNA staining, 2 of 6 in TCC G1 group and 5 of 6 in G3 group were positive. And it was noted examination was positive.

CONCLUSION

There have been no recurrence since transurethral resection in all IP in the study including the case recognized as aneuploid and positive for PCNA staining. But the present results suggest that among IPs, considered generally as a benign tumor, the case which has high proliferating character exists.

Endovascular Approach to a Ligated External Carotid Artery

A 37-year-old female with left sided multiple congenital haemangiomata presented with repeated haemorrhage. The haemorrhagic origin was from the angiomatous lesion with arteriovenous (AV) shunting in the tongue and pharynx. The patient had already undergone ligation of the external carotid artery. Vascularization was mainly from the portion of the external carotid artery distal to the occlusion. Our first approach via the collateral channels to the haemangioma failed. Through direct puncture of the distal end of the external carotid artery with the use of two dimensional road mapping, we succeeded in catheterizing the distal end of the external carotid artery at the first attempt without placing any pressure on the neck, and carried out selective embolisation without mishap.

Purification and characterization of glutaredoxin (thioltransferase) from rice (Oryza sativa L.)

We purified and characterized glutaredoxin (thioltransferase), which catalyzes thiol/disulfide exchange reaction, for the first time in plants. The purification procedure employed an immunoabsorbent, antiglutaredoxin-Sepharose. Glutaredoxin was purified about 2,200-fold from rice bran and it appeared to be homogeneous on SDS-PAGE. MALDI-TOF mass spectrometry revealed that the protein has a molecular mass of 11,097.9 Da. Rice glutaredoxin consists of 105 amino acid residues, containing the tetrapeptide -Cys-Phe-Pro (Tyr)-Cys-, which constitutes the active site of Escherichia coli and mammalian glutaredoxins. Inactivation assay also indicated that cysteine residues are responsible for enzyme activity. Kinetic analyses revealed that the enzyme did not exhibit normal Michaelis-Menten kinetics. The enzyme has an optimum pH of about 8.7 with 2-hydroxyethyl disulfide as a substrate. In addition, rice glutaredoxin has dehydroascorbate reductase activity, like mammalian glutaredoxin.

Treatment of a Small Hole Post-traumatic Carotid-Cavernous Fistula with a Non-Detachable Balloon Catheter. A Technical Note

SUMMARY

Transarterial detachable balloon embolisation has become a well established primary treatment of post-traumatic carotid cavernous fistula (CCF) (1-3). However, in some instances due to the complexity of the fistula, the treatment can be difficult or impossibile. A simple and useful technique using a non-detachable balloon catheter to easily navigate the riilcrocatheter into the fistula via the transarterial route is discussed in this paper. The non-detachable balloon catheter allows easy navigation of the micro catheter into the small hole fistula, and complete occlusion of the fistula was obtained using one interlocking detachable coil (IDC) in the draining veins. The method of using a non-detachable balloon catheter to navigate a micro catheter into a fistula is relatively easy via the transarterial route.

Diclofenac plasma protein binding: PK-PD modelling in cardiac patients submitted to cardiopulmonary bypass

Twenty-four surgical patients of both sexes without cardiac, hepatic, renal or endocrine dysfunctions were divided into two groups: 10 cardiac surgical patients submitted to myocardial revascularization and cardiopulmonary bypass (CPB), 3 females and 7 males aged 65 +/- 11 years, 74 +/- 16 kg body weight, 166 +/- 9 cm height and 1.80 +/- 0.21 m2 body surface area (BSA), and control, 14 surgical patients not submitted to CPB, 11 female and 3 males aged 41 +/- 14 years, 66 +/- 14 kg body weight, 159 +/- 9 cm height and 1.65 +/- 0.16 m2 BSA (mean +/- SD). Sodium diclofenac (1 mg/kg, im Voltaren 75 twice a day) was administered to patients in the Recovery Unit 48 h after surgery. Venous blood samples were collected during a period of 0-12 h and analgesia was measured by the visual analogue scale (VAS) during the same period. Plasma diclofenac levels were measured by high performance liquid chromatography. A two-compartment open model was applied to obtain the plasma decay curve and to estimate kinetic parameters. Plasma diclofenac protein binding decreased whereas free plasma diclofenac levels were increased five-fold in CPB patients. Data obtained for analgesia reported as the maximum effect (EMAX) were: 25% VAS (CPB) vs 10% VAS (control), P < 0.05, median measured by the visual analogue scale where 100% is equivalent to the highest level of pain. To correlate the effect versus plasma diclofenac levels, the EMAX sigmoid model was applied. A prolongation of the mean residence time for maximum effect (MRTEMAX) was observed without any change in lag-time in CPB in spite of the reduced analgesia reported for these patients, during the time-dose interval. In conclusion, the extent of plasma diclofenac protein binding was influenced by CPB with clinically relevant kinetic-dynamic consequences.

A source of haemorrhage in adult patients with moyamoya disease: the significance of tributaries from the choroidal artery

This study concerns 19 patients over 16 years of age with Moyamoya disease. Ten cases of intracranial haemorrhage, as the initial haemorrhagic event in patients aged from 21 to 55 (haemorrhagic group) and 9 cases of ischaemic events in 18- to 53-year-old patients (ischaemic group) were included. All haemorrhages were associated with intraventricular haemorrhages (IVH); and all but one case of thalamic haemorrhage were thought to be primary IVH (2 cases of small paraventricular haemorrhage; 2 of small haemorrhages in the splenium; 5 with no intracerebral haematoma). In the 9 patients of the ischaemic group, there were 2 cases of transient ischaemic attacks and 7 of cerebral infarction. Angiographic evaluations demonstrated that the abnormal basal vessel formation and the collateral supplies from the external carotid arteries were poorly developed in both groups. In contrast, the collateral circulation via the choroidal and posterior pericallosal arteries was well demonstrated. Furthermore, marked enlargement of the choroidal arteries and the medullary arteries derived from them was seen more frequently in the haemorrhagic group. These findings suggested that the haemodynamic load in the vessels supplying the walls of the posterior parts of the ventricles and the periventricular region was increased, especially in the haemorrhagic group. Those vessels were considered to be important sites of IVH in adult patients with Moyamoya disease.

Simplified physiological pacing after cardiac surgery

Temporary pacing wires are routinely placed at the end of cardiac surgery. These pacing wires are helpful in maintaining patients with postoperative bradycardias, and physiological pacing is also more desirable in critically ill patients. We herein report our simplified procedure for atrial pacing. This technique uses commercially available intravenous pacing catheters. The catheter is passed through the skin, and its tip is placed at the pericardial oblique sinus just between the right and left pulmonary veins. Atrial pacing is then initiated with a temporary pulse generator. This procedure is simple and effective for patients undergoing cardiac surgery. We also report two clinical cases that satisfactorily underwent atrial pacing using this procedure.

Characterization of non-pigmented Staphylococcus chromogenes

A large number of non-pigmented Staphylococcus chromogenes were isolated from the skin of piglets with exudative epidermitis and healthy pigs. Their characteristics were homologous with S. chromogenes type strain, except for pigment production. Strains of non-pigmented S. chromogenes exhibited high levels of DNA homology with S. chromogenes type strain. The colony morphology and pigmentation of non-pigmented S. chromogenes was very similar to S. hyicus type strain, but their characteristics differ in hyaluronidase production, heat stable DNase, Tween 80 hydrolysis and bacitracin resistance. Further, DNA homology drew a distinction between non-pigmented S. chromogenes and S. hyicus type strain.

Involvement of Epstein-Barr virus expression in testicular tumors

PURPOSE

Because orchitis has been described as a symptom of infectious mononucleosis which is caused by Epstein-Barr virus (EBV), a human tumor virus, we tried to ascertain the relationship between EBV and testicular tumors.

MATERIALS AND METHODS

Sixteen seminomas, 11 embryonal carcinomas and 25 nonmalignant control testes were examined for persistence and expression of the EBV genome. To detect expression of EBV, mRNA in situ hybridization and immunofluorescence staining by monoclonal antibodies were performed. To confirm the EBV genome in testes, we used nested polymerase chain reaction (PCR).

RESULTS

Messenger RNA in situ hybridization showed that all 27 seminomas and embryonal carcinomas expressed EB viral RNA, but the 25 nonmalignant testes did not. Monoclonal antibody staining showed EBV-related nuclear antigen (EBNA) 2 and latent membrane protein (LMP) 1 expression in testicular tumors. Nested polymerase chain reaction detected the EBV genome in normal testes as well as in testicular tumors.

CONCLUSIONS

These results suggest that EBV is related to testicular tumors.

[Clinical studies of inverted papilloma of the bladder]

Clinical studies were conducted on 9 cases of inverted papilloma of the urinary bladder which were transurethrally resected between August, 1987 and July, 1995 at our hospital, in males between 29 and 81 years of age (mean:58.3). Six of the 9 inverted papillomas were localized at the bladder neck and 3 in the trigone. Cystoscopic examinations revealed that inverted papillomas were divided into two types, one with a thick and short stalk with a smooth surface and the other with a thin and long stalk with/without a partial papillary surface. The majority of the former was located in the trigone and all of the latter cases in the bladder neck, suggesting that the two types occurred at different sites. Pathological examination by Hematoxylin-Eosin staining demonstrated that 5 of the 9 cases were of the trabecular type and 4 were of the grandlar type. Immunohistochemically, none of the tumors were stained with the antiprostatic-specific-antigen antibody revealed. Follow-up periods after the operation were from 12 to 48 months(mean:26.6 months) and no recurrence was observed.

Stump pressure as a guide to the safety of permanent occlusion of the internal carotid artery

Does the absolute value of the stump pressure (post-occlusion back pressure) become a useful index of a good collateral circulation? The authors continuously monitored the mean arterial pressure before, during and after 20-minute balloon test occlusion in 24 patients. The stump pressure was then compared with the results of 99mTc-hexa-methyl propyleneamine (99mTc-HMPAO) single photon emission computed tomography (SPECT) performed after 20 minutes of test occlusion. Patients who failed to tolerate even brief periods of carotid occlusion and showed asymmetric decreases in cerebral blood flow (CBF) on SPECT were divided into high and moderate risk groups. Those with no significant change in CBF on the occluded side formed the minimum risk group. Mean stump pressure was over 50 mmHg in three of a total of 13 patients in the high and moderate risk groups, and below 50 mmHg in two of the 11 patients in the minimum risk group. The ratios of the initial mean stump pressure to the pre-occlusion mean arterial pressure (%) and of the final mean stump pressure at the end of occlusion to the post-opening mean arterial pressure (%) did not exceed 58% in any patient in the high and moderate risk groups, and were at least 60% in all patients of the minimum risk group. Maintenance of a mean stump pressure of 60% or more of the mean systemic pressure during test occlusion may be a more useful index of a good collateral circulation than the absolute value of mean stump pressure.

Strategy for breast conserving treatment--analysis of recurrence and prognosis after breast cosnserving treatment

Two hundred and four patients with small breast cancer (T < or = 3.0 cm. N0 or N1a) were given breast conserving treatment (radiation group: 101, non-radiation group: 103) during the period from Feb. 1988 to Jan. 1995. Survival analysis of breast conserving treatment radiation group versus non-radiation group revealed the following: 1) Breast conserving treatment had a good prognosis, and a 5-year overall survival rate of 96.2%. 2) There was no significant difference of 5-year overall, disease-free and ipsilateral breast disease-free survival rate between the radiation group and non-radiation group. 3) Surgical margin involvement was the most significant risk factor in local recurrence after breast conserving treatment, and non-radiation was a possible risk factor. 4) Local recurrence was a significant risk factor for distant metastases after breast conserving treatment the same as node positive. These results suggested as follows: 1) Lumpectomy with a clear margin and radiation is the best choice for small breast cancer (T < or = 3.0 cm, N0 or N1a). 2) Adjuvant therapy after surgical treatment is necessary for local recurrence.

Dural-pial arteriovenous malformation with unusual venous drainage

A 41-year-old female presented with an uncommon mixed dural-pial arteriovenous malformation (AVM) with unusual venous drainage. Angiography at the initial operation for massive intracerebral hematoma in the parietal lobe showed no vascular malformations. Follow-up angiography 3 years later revealed a mixed dural-pial AVM at the previous surgical site. Unexpectedly, the venous drainage from the AVM was not into the patent superior sagittal sinus, but was retrograde into the contralateral cortical veins in the occipital lobe. No skull fracture or sinus thrombosis was demonstrated. The AVM was resected successfully without neurological deterioration. The pial portion of the lesion may have been a congenital anomaly, and the dural portion acquired. The development of a dural AVM at an earlier surgical site is uncommon, and may indicate the possible pathogenesis of acquired dural AVMs unrelated to sinus occlusion or accidental trauma. Furthermore, there are various possible patterns of venous drainage in vascular malformations.

Renal leiomyoma associated with tuberous sclerosis

The renal lesions characteristic of tuberous sclerosis are angiomyolipoma and cysts, with the former considered to be more common. Other renal tumors are rarely associated with tuberous sclerosis. Here we present a tuberous sclerosis patient with a renal leiomyoma which was detected incidentally during the investigation of fever of unknown origin.

Erythropoietin-producing adrenocortical carcinoma

A 62-year-old Japanese male with an erythropoietin-producing adrenocortical carcinoma is presented. The elevated erythropoietin level and erythrocytosis returned to normal after surgical removal of a huge left adrenal tumor weighing 1,580 g. A histopathological diagnosis of adrenocortical carcinoma was made. Despite adjuvant combined chemotherapy, the patient died of lung and liver metastases 3.5 months after operation. Although the possibility that the elevated plasma erythropoietin level and erythrocytosis resulted from local kidney hypoxia, caused by pressure from the huge adrenal tumor, cannot be completely neglected, the positive cytoplasmatic evidence of immunoreactive erythropoietin in the carcinoma cells and the detection of a high erythropoietin level in the tumor extract on radioimmunoassay confirmed that this is a very rare case of erythropoietin-producing adrenocortical carcinoma.

Tumorigenicity of EBNA2-transfected cells

The Epstein-Barr virus nuclear antigen 2 (EBNA2) gene is thought to be important for transformation by Epstein-Barr virus (EBV), but the mechanism of this transformation is little understood. Here, to examine the transforming ability of EBNA2, we transfected a rat fibroblast cell line F2408 with a recombinant EBNA2 expression plasmid and examined cell morphology, colony formation in soft agar, and tumorigenicity in nude mice. The morphology of transfected clones was similar to those of untransfected cells, but two of seven clones grew in soft agar, and four clones of seven clones reproducibly formed tumors in nude mice. These four clones showed EBNA2 expression, but non-tumorigenic clones did not. These results indicate that the expression of EBNA2 is correlated with tumorigenicity.

[Giant schwannoma in the pelvic cavity presenting as renal failure: a case report]

A case of giant schwannoma in the pelvic cavity detected with renal failure is reported. A 50-year-old man was referred to another clinic with chief complaints of general fatigue and edema of the face and dorsa of the feet. On March the 4th 1994, he was hospitalized in the clinic because of renal failure. Bilateral hydronephrosis and a giant pelvic tumor were found by computed tomography (CT) and ultrasonography. Because bilateral percutaneous nephrostomies failed to recover his renal function, he was referred to our clinic for the purpose of hemodialysis and the further examination of the tumor on March 16, 1994. The pelvic angiography showed that the tumor was fed by the vessel from the left internal iliac artery. After the chemo-embolization from the feeding artery, tumor resection was performed on May 9, 1994. The tumor was 16x13x10 cm in size, and 1,110 g in weight. The histological findings of the tumor revealed the mixed type schwannoma of Antoni A and B. Six months after the operation, he has had no tumor recurrence. This is a rare case of pelvic schwannoma which was detected with renal failure. We reviewed and discussed 56 cases of schwannoma in the pelvic cavity, including our case, in the Japanese literature.

[Intrascrotal fibrous pseudotumor accompanied by pelvic kidney with ectopic ureteral opening: a case report]

A case of intrascrotal fibrous pseudotumor accompanied by pelvic kidney with ectopic ureteral opening is reported. The patient was a 65-year-old man with the complaint of swelling of the right scrotal contents. Ultrasonography showed a heterogeneous mass with acoustic shadow from the right epididymis to right spermatic cord. Intravenous pyelography revealed a non-visualizing right kidney. Endoscopic examination was performed because of the right non-functioning kidney and right epididymectomy was performed. Endoscopic findings showed that the ureteral opening existed at 6 degrees of the bladder neck. Retrograde pyelography demonstrated the right kidney in the pelvic cavity. The tumor was stony hard and 30 x 50 mm in size. Pathological diagnosis of the tumor was a fibrous pseudotumor. We reviewed and discussed 22 cases of fibrous pseudotumor, including our case, in the Japanese literature.

[Recurrence of transitional cell carcinoma in bilateral upper urinary tracts and ileal conduit with invasion in the abdominal wall around nephrostomy after total cystectomy: a case report]

A case of recurrence of transitional cell carcinoma in bilateral upper urinary tracts and ileal conduit with invasion in the abdominal wall around nephrostomy after total cystectomy is presented. A 33-year-old man with right nephrostomy, after total cystectomy, construction of ileal conduit, bilateral partial ureterectomy and left nephrectomy for transitional cell carcinoma at another hospital was referred to our hospital because of further recurrence in the right renal pelvis and ileal conduit. He had had left nephrostomy before the left nephrectomy was performed. Right nephrectomy and total extirpation of ileal conduit were performed and hemodialysis was started from the day after the operation. However, several weeks later, transitional cell carcinoma was detected pathologically in the left abdominal wall around the left nephrostomy which had been inserted. The renal pelvis was inferred to have leaked urine around the nephrostomy and invasion arose in this region. After radiation therapy he was discharged but he died from recurrence of carcinoma 9 months after the operation. After total cystectomy, examinations by percutaneous puncture of the renal pelvis are very effective for evidence of recurrence in the upper urinary tract. However, we emphasize that the percutaneous technique carries the risk of tumor invasion through the percutaneous urinary tract.

Expression of bone matrix protein messenger ribonucleic acids in human breast cancers. Possible involvement of osteopontin in development of calcifying foci

BACKGROUND

Development of calcifying foci is a fairly common finding in human breast cancers, and the deposition of calcium phosphate is observed in such foci. The calcium phosphate is a physiologic component of bones and teeth. Since the expression of messenger (m) RNAs of osteopontin (OPN), osteocalcin (OC), osteonectin (ON), and matrix gla protein (MGP) has been described in bones and teeth, we examined the mRNA expression of OPN, OC, ON, or MGP in the calcifying foci that were observed in human breast cancers.

EXPERIMENTAL DESIGN

Cell types expressing mRNAs of OPN, ON or MGP were identified with combination of in situ hybridization and immunohistochemistry.

RESULTS

The OPN mRNA-expressing cells clustered around the necrotic foci within cancer cell nests, and the examination with anti-OPN antibody revealed that OPN protein was localized in such necrotic foci where calcium phosphate deposited. The OPN mRNA-expressing cells were identified as macrophages by staining the adjacent section with the anti-CD68 PG-M1 monoclonal antibody which specifically recognizes macrophages. Neither ON mRNA-expressing cells nor MGP mRNA-expressing cells appeared to correlate with the deposition of calcium phosphate.

CONCLUSIONS

The OPN protein produced by macrophages appeared to play a significant role for development of calcifying foci within necrotic area of breast cancers.

Experimental saccular aneurysms. II. A new model in swine

A new technique for surgical construction of experimental lateral saccular aneurysms on the common carotid artery of swine is described. It involves end-to-side suturing of an isolated segment of vein to an artery. During a short period of parent artery clamping, an elliptical arteriotomy is fashioned through the open-ended vein graft, the open end of which is subsequently tied and clamps are removed to form an aneurysmal vein pouch. The principal advantage of this technique is the short period of vascular clamping necessary to isolate a segment of the parent artery. This prevents severe endothelial injury and prolonged postoperative vasospasm, both of which may promote intra-aneurysmal thrombosis. Narrow- or wide-necked aneurysms can be created. Steps in the surgical construction of this model are detailed, and specific advantages of using swine are highlighted.