Temperature- and pH-dependent cytotoxic effect of the hemolytic lectin CEL-III from the marine invertebrate Cucumaria echinata on various cell lines

We investigated the cytotoxicity of CEL-III, one of four Ca2+-dependent galactose/N-acetylgalactosamine (GalNAc)-binding lectins from the marine invertebrate Cucumaria echinata. Among six cell lines tested, MDCK cells showed the highest susceptibility to CEL-III cytotoxicity and its LD50 was estimated to be 53 ng/ml, while no significant cytotoxicity of CEL-III was observed in CHO cells up to 10,000 ng/ml. In the presence of 0.1 M lactose, the cytotoxicity of CEL-III was strongly inhibited. The binding studies using FITC-labeled CEL-III revealed that the amount of CEL-III bound to MDCK cells was about 2-fold greater than that in the case of CHO cells. The cytotoxicity of CEL-III increased with decreasing temperature. The surviving fractions of Vero cells exposed to CEL-III at 4 degrees C were immediately decreased, and more than 90% of exposed cells were killed within 20 min, whereas at 37 degrees C much longer exposure period (more than 10 h) was required to kill 50% of the cells. CEL-III induced the release of carboxyfluorescein (CF) from CF-loaded MDCK cells and this activity was markedly increased at alkaline pH (pH 10) and at lower temperature (4 degrees C). Even in CHO cells, considerable CF release was induced by CEL-III at 4 degrees C and at pH 10 but not at pH 7.5 at both temperatures. In agreement with these results, CHO cells exposed to CEL-III at 4 degrees C and at pH 10 were killed in a dose-dependent manner. These results suggest that CEL-III exhibits cytotoxicity through damaging the plasma membrane by pore-formation in a temperature- and pH-dependent manner. Different susceptibility of each cell line to CEL-III cytotoxicity may be due to differences in the processes leading to pore-formation after binding to cell-surface carbohydrates.

Endovascular treatment for acute thrombotic occlusion of the middle cerebral artery: local intra-arterial thrombolysis combined with percutaneous transluminal angioplasty

We report our experience in treating 15 patients with acute thrombotic occlusion of the M1 or M2 segment of the middle cerebral artery who underwent intra-arterial thrombolytic therapy alone or in combination with percutaneous transluminal angioplasty (PTA). The results were compared with those of 30 patients with acute embolic occlusion of the same artery. Intra-arterial thrombolysis was performed in 10 patients and thrombolysis combined with PTA in 5 in whom symptoms reappeared due to restenosis or reocclusion, or in whom recanalisation was not successfully accomplished by thrombolysis alone. In the patients with embolism recanalisation was observed in 28 (93 %) and there was no patient with reocclusion. In the patients with thrombosis recanalisation immediately after thrombolysis alone was observed in 9 of 15 (60%). Restenosis, with reappearance of symptoms, occurred in 2 of these (22 %). In the patients who also underwent PTA, angiography after 1 month did not demonstrate any restenosis or reocclusion. Thrombolysis combined with PTA for acute thrombotic stroke may provide an effective procedure for restoring patency and preventing reocclusion of the occluded artery.

Carbohydrate-binding properties of the hemolytic lectin CEL-III from the holothuroidea Cucumaria echinata as analyzed using carbohydrate-coated microplate

The carbohydrate-binding properties of the hemolytic lectin CEL-III from the Holothuroidea Cucumaria echinata were studied using the microplate assay system which we have recently developed [Hatakeyama et al. (1996) Anal. Biochem. 237, 188-192]. When the binding of CEL-III to lactose covalently immobilized on a microplate was examined using colloidal gold solution, the binding was detected with as little as 1 microgram/ml protein. Affinity of several carbohydrates to CEL-III was assessed by means of an inhibition experiment using the lactose-coated plate and it was found that N-acetylgalactosamine has the highest affinity for CEL-III, followed by lactose and lactulose. Examination of the binding of CEL-III to the lactose-coated plate at various pH values and temperatures revealed that the affinity is higher in the acidic pH region and at lower temperatures. From the Ca(2+)-dependence profile for the binding of CEL-III to the lactose-coated plate, the apparent dissociation constant for Ca2+ was estimated to be 2.3 mM. These results suggested that the carbohydrate-binding properties of CEL-III are closely related to its hemolytic activity, although an additional interaction between the protein and the lipid bilayer, which is enhanced in the alkaline pH region, also seems to be necessary for its hemolytic action.

[Renal function in children with reflux nephropathy followed up more than 10 years after disappearance of vesicoureteral reflux: usefulness of alpha 1-microglobulin as a marker to predict the prognosis of these children]

BACKGROUND

Although reflux nephropathy (RN) is one of the most important causes of renal failure in adolescence and young adulthood, we have no appropriate markers to know the future course of children with RN. In order to find out useful marker to predict the prognosis of these children, we analyzed the result of over ten years follow-up of children with RN.

METHODS

We evaluated renal function in 25 patients (aged between 11 years and 23 years, 14 males and 11 females) with RN using urinary alpha 1-microglobulin (alpha 1 m), urinary albumin and 99mTc-dimercaptosuccinic acid (DMSA) renal scan. All patients were followed up more than 10 years after disappearance of vesicoureteral reflux.

RESULTS

Of 25 patients, 13 showed high levels of urinary alpha 1 m (> 4.4 mg/gCr = upper normal limit) during follow-up period. Among them, renal dysfunction developed in 9 on DMSA renal scan and/or serum creatinin (Cr) level. Before puberty, all patients, even children with renal dysfunction (serum Cr > 1.0 mg/dl), remained in normal or slight high urinary albumin levels. Five cases, showed high levels of urinary alpha 1 m before puberty, demonstrated a remarkable increase of urinary albumin levels after puberty.

CONCLUSION

From these results, it was suggested that urinary levels of alpha 1 m could be utilized as a marker to predict the prognosis of children with RN.

Quantitative determination of cardiac glycosides in Digitalis lanata leaves by reversed-phase thin-layer chromatography

An analytical method for the determination of cardiac glycosides in Digitalis lanata leaves by reversed-phase thin-layer chromatography (RP-TLC) was developed. The procedure consisted of extraction of dry leaf powder with 50% methanol and clean-up by Sep-Pak cartridges prior to RP-TLC analysis. RP-TLC was performed on an octadecylsilyl bonded silica gel plate, using a developing solvent of acetonitrile-methanol-0.5 M NaCl (1:1:1) for primary glycosides and acetonitrile-methanol-0.5 M NaCl (12:7:9) for secondary glycosides. The plate was scanned with a reflectance densitometer at 225 nm. The quantitation was carried out by the internal standard method. The present method is reliable and relatively simple for the determination of cardiac glycosides in Digitalis lanata leaves.

A strategy for selective anti-cancer drug concentration increase in rat glioma tissue with Ca(2+)-channel blocker co-administration: calcium kinetics in intra-glioma arteriolar smooth muscle cells

A rat glioma model was employed to estimate the Ca2+ kinetics in the tumor arteriolar smooth muscle cells. Electron microcytochemistry revealed that the density of intracellular Ca2+ deposits in the intra-tumor arteriolar smooth muscle cells was significantly greater, with slightly higher membrane Ca(2+)-adenosine triphosphatase (ATPase) activity, compared to the contralateral cerebral arterioles. Furthermore, the administration of tyrphostin, a tyrosine kinase inhibitor, specifically increased only the intra-tumor blood flow. These findings suggest that the condition of the intra-tumor arteriole alters the susceptibility to contraction by the accelerated Ca2+ influx into the cytoplasm mediated through the tyrosine kinase pathway. After the administration of diltiazem, which also has a blocking effect on the Ca(2+)-channel mediated through this pathway, the local intra-tumor blood flow showed an increase of 39% with a marked decrease of intracellular Ca2+ concentration of the arteriolar smooth muscle cells in the tumor, while the blood flow in the basal ganglia increased by only 8%. The intra-tumor concentration of Nimustine-HCl (ACNU) with co-administration of diltiazem was significantly increased compared to that without the co-administration. Co-administration of diltiazem may be a valuable strategy in chemotherapy for glioma in affording the selective increase of intra-tumor concentration of the anti-cancer drug.

[Three cases of acute subdural hematoma in abused children]

We encountered 3 cases of battered children with acute subdural hematoma. In this report, we discuss the difficulties in treating this condition surgically, and we emphasize the importance of early diagnosis and treatment of abused children and their parents. Case 1: A girl, aged 2 months, was brought in by her mother, because the child had become drowsy. The mother stated that the child had been battered by her father. Physical examination revealed tense anterior fontanelle, bruises on her face, consciousness disturbance and retinal bleeding. Marked anemia was revealed on laboratory studies. A computed tomographic (CT) scan demonstrated an interhemispheric subdural hematoma in the parietooccipital region. She was treated conservatively for 2 months. Follow-up CT revealed a bilateral chronic subdural hematoma. Burr hole irrigation and drainage on both sides brought about complete disappearance of these lesions. Case 2: A girl, aged 1 year and 9 months, was brought in by her parents. According to her mother's allegation, the child fell down from the top of an indoor slide and became comatose. Physical examination revealed severe malnutrition, loss of consciousness, dilated pupils and negative light reflex. Numerous areas of subcutaneous bleeding and skin erosions were seen on her back and abdomen. Marked anemia was revealed on laboratory studies. CT scan demonstrated a left acute subdural hematoma and massive brain swelling. Despite an emergency craniotomy, the child died 5 days later. Case 3: A 4-year-old boy was admitted in a comatose state. According to his mother's allegation, he was thrown to the floor from a 1.5m height and struck against a wall by his father. Physical examination revealed severe malnutrition, consciousness loss, dilated pupils and negative light reflex. Many scratches and bruises were seen over his whole body, especially on his back. Marked anemia was revealed on laboratory studies. A CT scan demonstrated a left acute subdural hematoma and massive brain swelling. Three days later, he died despite emergency craniotomy. The incidence of battered children is increasing in Japan, and these cases sometimes involve severe head injuries, such as subdural hematoma. In these cases, successful surgical treatment is difficult after admission to the neurosurgical institute. This may result from late admission as well as marked anemia and malnutrition. Therefore, we conclude that early diagnosis of child abuse and treatment of the abused child and psychological treatment for their parents are very important.

Nosocomial diarrhoea in the elderly due to enterotoxigenic Clostridium perfringens

To diagnose sporadic diarrhoea due to Clostridium perfringens infection, faecal specimens from elderly patients were examined directly for C.perfringens enterotoxin using reverse passive latex agglutination assay, and then cultured for this organism. C.perfringens isolates from those samples were grouped by slide agglutination and by pulsed-field gel electrophoresis (PFGE). Fifty of the 60 isolates agglutinated with newly raised antiserum WX2 and 38 shared the same genomic PFGE pattern. Characteristics of the epidemics and experimental data suggest that the diarrhoea was caused by a nosocomial spread of C.perfringens, and not by a food-borne outbreak.

[Investigation of retention time of intravesical instillation therapy with pirarubicin (THP)]

The effective and less side effect retention time of intravesical instillation therapy with Pirarubicin (THP) was investigated for the treatment of urinary bladder tumor. Fifty-seven cases of urinary bladder tumor were treated by intravesical instillation therapy with THP (20 mg/40 ml) a total of 6 times, with the first instillation at the time of surgery and the other 5 at a rate of three times a week thereafter. The retention time was 30 minutes, and it was allowed to last 10 or 60 minutes for comparison in some cases. Tumor and normal tissue were examined in the first instillation, and normal tissue in the sixth instillation. Infiltration to the bladder wall of THP was observed under fluorescence microscopy. Although the amount of tumor uptake was larger than normal tissue in the first instillation, no satisfactory infiltration was obtained. Repeated administration of THP with the retention time of 30 minutes enhanced the uptake and increased the infiltration in many cases, and side effects were scarcely noted. Retention time of 10 minutes was unsatisfactory, while the retention time of 60 minutes was discontinued in the early stage of treatment due to severe irritative bladder symptoms. Therefore, a retention time of 30 minutes is adequate in the case of repeated administration of THP in a short period.

Oligomerization of the hemolytic lectin CEL-III from the marine invertebrate Cucumaria echinata induced by the binding of carbohydrate ligands

The hemolytic lectin CEL-III is a Ca2+-dependent, galactose/GalNAc-specific lectin purified from the marine invertebrate Cucumaria echinata (Holothuroidea). We found that this lectin forms ion-permeable pores in erythrocyte and artificial lipid membranes that have specific carbohydrate ligands on the surface. The hemolytic activity of CEL-III exhibited characteristic pH dependence; activity increased remarkably with pH in the alkaline region, especially above pH 9. When rabbit erythrocyte membrane was examined by immunoblotting using anti-CEL-III antiserum after treatment with CEL-III, the irreversible binding of the CEL-III oligomer increased with pH, indicating that the increase in hemolytic activity at higher pH is associated closely with the amount of oligomer irreversibly bound to the membrane. Surface hydrophobicity of CEL-III, as measured by the fluorescent probe 8-anilino-1-naphthalenesulfonate, increased markedly with the binding of specific ligands such as lactose, lactulose, and N-acetyllactosamine at pH 9-10 in the presence of 1 M NaCl. The enhancement of surface hydrophobicity induced by the binding of carbohydrates was also accompanied by the formation of a CEL-III oligomer, which was found to be the same size on sodium dodecyl sulfate-polyacrylamide gel electrophoresis as the oligomer that formed in CEL-III-treated erythrocyte membranes. Far-UV circular dichroism spectra of CEL-III and the oligomer revealed a definite difference in secondary structure. These data suggest that the binding of CEL-III to specific carbohydrate ligands on the erythrocyte surface induces a conformational change in the protein, leading to the exposure of a hydrophobic region which triggers oligomerization and the irreversible binding of the protein to the membrane.

An assay for lectin activity using microtiter plate with chemically immobilized carbohydrates

A simple microtiter plate assay for lectins or carbohydrate-binding proteins was developed. The method utilizes carbohydrates immobilized in the wells of the microtiter plate containing primary amino groups on their surface. After incubation of the lectins, bound proteins are measured by the protein assay using the colloidal gold solution. When the binding of Ricinus communis agglutinin, concanavalin A, and wheat germ agglutinin was measured using the microtiter plate wells coated with lactose, mannose, or N-acetylglucosamine, binding of the lectins according to their known specificity was observed. Inhibition experiments with various carbohydrates also demonstrated that the specificity of lectins for different carbohydrates could be determined quantitatively. Since there is no need for modification of the lectins, such as biotinylation or conjugation with marker enzymes, the carbohydrate-binding ability of intact proteins can be easily determined by this method. When gel filtration fractions from the extract of the marine invertebrate Cucumaria echinata were subjected to this assay, different carbohydrate-binding activities were observed with different elution profiles, suggesting that this assay could also be widely applicable for the simultaneous detection of lectins from various sources.

A clinicopathological study of familial abdominal aortic aneurysms

The purpose of this report is to document what we have observed in patients with familial abdominal aortic aneurysms (FAAAs) between 1987 and 1993. Patients with FAAAs were reviewed and compared with those without familial clustering with regard to age, sex, past history, laboratory data, smoking habits, and type of implanted graft. We identified 7 families among which a total of 15 members had AAAs. The incidence of familial clustering reached 5.4%. The mean age of the FAAA group was significantly younger than that of the non-FAAA group (mean age: 65.8 +/- 10.3 versus 71.0 +/- 7.3 years). In the FAAA group, furthermore, patients in the second generation were significantly younger than those in the first generation (mean age: 55.3 +/- 10.5 versus 69.6 +/- 7.4 years). FAAA was significantly more often complicated by ischemic cardiac diseases. There were no significant differences in other risk factors. Interestingly, however, we observed a morphological similarity in the shape of the aneurysms within each family. Histological examinations showed moderate or severe lymphocytic infiltration into the aortic adventitia in 6 out of 9 cases. FAAA is clinically important, because it can represent a high-risk group that may benefit from a screening program for early detection and elective management of AAA. Studies of FAAAs will be useful for elucidating the pathogenesis of AAAs.

[Operative results in fourteen cases of paranasal sinus and anterior cranial fossa lesions surgically treated by an extended transbasal approach]

We describe the outcomes and complications of 14 patients with paranasal sinus and anterior cranial fossa lesions surgically treated by an extended transbasal approach, originally described by Kawakami, in our department. They were 10 patients with malignant tumors, 2 with benign tumors, and 2 with inflammatory diseases. A bifrontal craniotomy was performed using a high coronal skin incision, and the orbital rim and roof were removed after the dissection of the dura mater from the anterior skull base. Transcranial resection of the tumor was performed, and assisted by transnasal and transmaxillar resection using a nasal endoscope. Reconstruction of the anterior skull base was performed with the fasica lata and galeopericranial flap in all cases, temporal musculo-pericranial flap in 3 and free bone flap from the cranial convex in 3. Among 10 patients with malignant tumors (malignant melanoma; 4, squamous cell carcinoma; 2 adenocarcinoma; 1, malignant plemorphic adenoma; 1, chondrosarcoma; 1, and neuroblastoma; 1), total removal was performed in 5 patients and subtotal removal in 5 patients. Though local recurrence of the tumor was recognized in 6 patients, only one underwent additional surgery. Eight patients survived, and 2 patients died of systemic metastasis of the tumor and complications due to liquorrhea. Seven patients obtained a good quality of life, and the mean survival period in 8 patients still living was 27 months after the first surgery. In 2 patients with benign tumors (chordoma and osteoma), partial and total removal was performed. The patient with chordoma was operated on several times by this approach and the transoral approach, respectively. Each had a good postoperative course.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino acid sequence of a C-type lectin CEL-IV from the marine invertebrate Cucumaria echinata

The complete amino acid sequence of a Ca(2+)-dependent lectin, CEL-IV, from the marine invertebrate Cucumaria echinata was analyzed. The established sequence showed that CEL-IV comprises 157 amino acid residues with a molecular mass of 17,098 Da (without disulfide bonds). From comparison with other proteins, CEL-IV was apparently homologous with the C-type lectin family. The identity was relatively high with a sea cucumber (Stichopus japonicus) lectin SJL-I (40.0%) and a sea urchin (Anthocidaris crassispina) lectin echinoidin (32.6%). In CEL-IV, one interchain and two intrachain disulfide bonds were identified. Interestingly, one of the two intrachain disulfide bonds that were highly conserved among the other C-type lectins was missing, suggesting that this might be a characteristic feature of C-type lectins in the Holothuroidea.

Changes in coagulation and fibrinolytic system after local intra-arterial thrombolysis for acute ischemic stroke

Intracerebral hemorrhagic transformation is one of the most important complications of thrombolytic therapy for acute ischemic stroke. The relationship between changes in markers for the coagulation and fibrinolytic systems and occurrence of hemorrhagic transformation was determined after local intra-arterial thrombolytic therapy using urokinase (UK) (24 patients) or recombinant tissue plasminogen activator (t-PA) (10 patients) within 6 hours of onset. All 34 patients had no hypodensity areas on initial computed tomography scans. Plasma concentrations of fibrinogen-fibrin degradation products (FDP), fibrinogen, alpha 2-plasmin inhibitor (alpha 2-PI), plasmin-alpha 2 plasmin inhibitor complex (PIC), thrombin-antithrombin III complex (TAT), and D-dimer were measured. Hemorrhagic transformation occurred in seven patients (21%) with complete or partial recanalization; four in the UK group and three in the t-PA group. Doses of the thrombolytic agents did not correlate with the incidence of hemorrhagic transformation. The FDP levels in the hemorrhagic transformation group treated with UK significantly increased immediately and 1 hour after the therapy. The alpha 2-PI activities decreased and PIC levels increased in both the hemorrhagic transformation and the nonhemorrhagic groups after the therapy. The TAT levels in both groups tended to be higher than the normal range, but there was no significant difference from the pretreatment levels. The D-dimer levels in the hemorrhagic transformation group were higher than those in the nonhemorrhagic group at 24 hours after the therapy. Furthermore, the D-dimer levels were significantly higher in patients with complete recanalization compared with those with none or partial recanalization.(ABSTRACT TRUNCATED AT 250 WORDS)

Interaction of the hemolytic lectin CEL-III from the marine invertebrate Cucumaria echinata with the erythrocyte membrane

CEL-III is one of four Ca(2+)-dependent galactose/N-acetylgalactosamine (GalNAc)-binding lectins from the marine invertebrate Cucumaria echinata which exhibits hemolytic activity, especially toward rabbit and human erythrocytes. The hemolytic activity of CEL-III was also Ca(2+)-dependent and was found to be inhibited by galactose or GalNAc-containing carbohydrates, suggesting that the hemolysis was caused by CEL-III binding to specific carbohydrates on the erythrocyte membrane by Ca(2+)-dependent lectin activity, followed by partial destruction of the membrane. The activity of CEL-III was highest at 10 degrees C and decreased markedly with increasing temperature, unlike usual enzymatic reactions. The hemolytic activity of CEL-III increased with increasing pH from neutral to 10, but almost no hemolysis was observed below pH 6.5. Immunoblotting analysis of proteins from the erythrocyte membrane after treatment with CEL-III indicated that CEL-III aggregates were irreversibly bound to the membrane. When erythrocytes were incubated with CEL-III in the presence of dextran with molecular masses greater than 4 kDa, lysis was impeded considerably, while a concomitant release of ATP was detected from these osmotically protected cells. It was found that CEL-III released carboxyfluorescein from artificial globoside-containing lipid vesicles, and it is suggested that CEL-III is a novel pore-forming protein with the characteristics of a Ca(2+)-dependent lectin, which may act as a toxic protein to foreign microorganisms.

Hearing improvement following removal of acoustic neuroma with preoperative sudden deafness

We report three cases of small intracanalicular acoustic tumor with sudden hearing loss (SHL). The tumors were totally removed through the middle cranial fossa approach, preserving both the facial and cochlear nerves between one and four months after the onset of deafness. From one to three months postoperatively hearing has improved significantly. Hearing improvement in acoustic tumor surgery is a new aspect to be studied more in the future. Although the data are insufficient to draw broad conclusions, surgical removal of small acoustic tumors is rational to improve hearing, reduce or eliminate tinnitus and prevent recurrent attacks of deafness or vertigo. Factors relevant to postoperative hearing improvement are considered.

Purification and characterization of four Ca(2+)-dependent lectins from the marine invertebrate, Cucumaria echinata

Four Ca(2+)-dependent, N-acetylgalactosamine/galactose-specific lectins were purified from the marine invertebrate, Cucumaria echinata (Holothuroidea), by column chromatography on lactosyl-Sepharose 4B, Sephacryl S-200, and Q-Sepharose. The molecular masses of these lectins were estimated to be 27 kDa (CEL-I), 35 kDa (CEL-II), 45 kDa (CEL-III), and 68 kDa (CEL-IV) on SDS-PAGE under nonreducing conditions. Among these lectins, CEL-I and CEL-IV strongly agglutinated rabbit and human erythrocytes, and were found to recognize N-acetylgalactosamine and galactose-containing carbohydrates from the results of a hemagglutination inhibition assay. In contrast, CEL-II failed to agglutinate any erythrocytes tested, although its carbohydrate-binding ability was confirmed by a carbohydrate-binding assay involving asialofetuin-horseradish peroxidase. Interestingly, CEL-III caused hemolysis of rabbit and human erythrocytes, while it showed only hemagglutination of chicken and horse erythrocytes at relatively high concentrations. The hemolytic activity of CEL-III was also dependent on the Ca(2+)-concentration, and inhibited by N-acetylgalactosamine and galactose-containing carbohydrates, suggesting that the hemolysis was caused by Ca(2+)-dependent binding of CEL-III to specific carbohydrate chains on the erythrocyte surface and the following partial destruction of the membrane.

Amino acid sequence of a lectin from the sea cucumber, Stichopus japonicus, and its structural relationship to the C-type animal lectin family

The complete amino acid sequence of SJL-I, a lectin from the sea cucumber, Stichopus japonicus, was determined by sequence analysis of peptides derived on enzymatic and chemical fragmentation of the protein. SJL-I consists of 143 amino acid residues and its molecular mass was calculated to be 15,837 Da. Comparison of the sequence of SJL-I with a database revealed that SJL-I exhibits apparent homology with C-type lectins, especially with those of marine invertebrates. The highest homology (identity 28.6%) was found with echinoidin, a lectin from the sea urchin, Anthocidaris crassispina. Comparison of the sequence of SJL-I with those of other C-type lectins indicated that the conserved amino acids are relatively abundant in the C-terminal half of their carbohydrate-recognition domains (CRDs), that can be considered to be involved in binding with Ca2+ as well as carbohydrates.

Primary Ewing's sarcoma of the occipital bone--case report

A 12-year-old boy presented with primary Ewing's sarcoma of the occipital bone manifesting as intermittent high fever and local pain in the occipital region. Plain skull x-ray films disclosed an unclear lytic lesion in the occipital bone. Computed tomography and magnetic resonance imaging demonstrated the irregularly enhanced mass. The tumor was removed totally. He received intensive chemotherapy and radiation therapy postoperatively. No recurrence or metastasis has been noted, and he was in good condition 18 months after the operation.

Evaluation of risk of hemorrhagic transformation in local intra-arterial thrombolysis in acute ischemic stroke by initial SPECT

BACKGROUND AND PURPOSE

Thrombolytic therapy was carried out on patients with acute ischemic stroke, and the risk of hemorrhagic transformation was evaluated from the residual cerebral blood flow (CBF) by pretherapeutic single-photon emission-computed tomography (SPECT).

METHODS

Local intra-arterial thrombolytic therapy was carried out using urokinase or recombinant tissue plasminogen activator (rt-PA) within 6 hours from the onset in 34 patients in whom no hypodensity areas were observed on the initial computed tomography examination. In the 20 patients with carotid territory occlusion who underwent 99mTc-labeled hexamethylpropyleneamine oxime (99mTc-HMPAO) SPECT, the residual CBF of the ischemic region was evaluated semiquantitatively by calculating two parameters: the ischemic regional activity to cerebellar activity ratio (R/CE ratio) and asymmetry index (AI).

RESULTS

The occluded vessels could be recanalized in 22 (92%) of the 24 patients in the urokinase group and in all 10 of the patients in the rt-PA group. Hemorrhagic transformation appeared in 4 patients in the urokinase group and 3 patients in the rt-PA group. Among the 20 patients who underwent SPECT before the treatment, the residual CBF was lower in the 5 patients who developed hemorrhagic transformation than in the 15 who did not (P < .05). Hemorrhagic transformation occurred in all patients with R/CE ratio of less than 0.35 and AI of more than 1.5.

CONCLUSIONS

The risk of hemorrhagic transformation after recanalization of occluded vessels by local intra-arterial thrombolytic therapy was considered to be high when the pretherapeutic residual CBF was markedly reduced.

Computer-aided 3-dimensional visualization of abdominal aortic aneurysms from CT images

A new method for elucidating the process of abdominal aortic aneurysm enlargement is presented herein. First, 3-dimensional (3-D) reconstructed images were used to precisely evaluate the size of an aneurysm, after which reconstruction and a volume analysis of images were performed with a personal computer system using serial computed tomographic films. The evolution of an aneurysm was examined by the detailed reconstruction, and an estimation of size was achieved by accurately measuring the figure reconstructed from the angle perpendicular to the axis of the contour. In quantifying the enlargement of an aneurysm, an exact evaluation of volume changes and morphological changes can be performed using the 3-D reconstruction method from the film series obtained at follow-up studies. The volume analysis proved especially useful for evaluating the axial expansion of aneurysms with stable maximum diameters.

Purification and characterization of two lectins from the sea cucumber Stichopus japonicus

Two Ca(2+)-dependent lectins were purified from the sea cucumber Stichopus japonicus by affinity chromatography on lactosyl-Sepharose 4B and ion-exchange chromatography on Q-Sepharose. Their molecular masses were estimated to be 13kDa (SJL-I) and 15 kDa (SJL-II) on SDS-PAGE. SJL-I agglutinated rabbit erythrocytes as well as human A, B, and O-type erythrocytes, but SJL-II agglutinated only rabbit erythrocytes. Hemagglutination by SJL-I was competitively inhibited by N-acetyl-D-galactosamine and galactose-containing carbohydrates. On the other hand, only lactose, melibiose, and raffinose gave weak inhibition of hemagglutination by SJL-II, suggesting that SJL-II may have high specificity for particular complex carbohydrate(s) on the surface of rabbit erythrocytes. SJL-II was activated at ten times lower Ca2+ concentration than SJL-I. Both lectins lost activity in acidic pH, while SJL-I appeared more stable down to pH 4.5.

Recovery of protein synthesis in tolerance-induced hippocampal CA1 neurons after transient forebrain ischemia

Protein synthesis at various recirculation times after 5-min transient forebrain ischemia was evaluated in gerbil hippocampal CA1 pyramidal neurons that had acquired tolerance to delayed-type ischemic injury. Evaluation was performed by observing polyribosomes under electron microscopy, and by [14C]leucine autoradiography. Hippocampal CA1 pyramidal neurons in the gerbils acquired stable and reproducible tolerance to delayed-type ischemic injury subsequent to a 5-min ischemia by pretreatment that consisted of loading two 2-min ischemic periods at a 1-day interval, followed by 48 h of recirculation. During the early phase following the 5-min ischemia, polyribosomal disaggregation, loss of dendritic microtubules, and significant suppression of radiolabeled leucine incorporation were observed in the tolerance-induced CA1 neurons as well as in the non-tolerance-induced neurons. While these findings persisted in the non-tolerance-induced neurons throughout the duration of the experiment, most of the tolerance-induced neurons demonstrated reaggregation of cytosomal ribosomes, increase in the number of dendritic microtubules, and restoration of impaired amino acid incorporation 24 h after the ischemia. These findings suggest that recovery of protein synthesis during the early post ischemic phase is essential for CA1 neuron survival after ischemic injury.