Shear Stiffness of 4 Common Intracranial Tumors Measured Using MR Elastography: Comparison with Intraoperative Consistency Grading

BACKGROUND AND PURPOSE

The stiffness of intracranial tumors affects the outcome of tumor removal. We evaluated the stiffness of 4 common intracranial tumors by using MR elastography and tested whether MR elastography had the potential to discriminate firm tumors preoperatively.

MATERIALS AND METHODS

Thirty-four patients with meningiomas, pituitary adenomas, vestibular schwannomas, and gliomas scheduled for resection were recruited for MR elastography. On the elastogram, the mean and the maximum shear stiffnesses were measured by placing an ROI on the tumor. Blinded to the MR elastography findings, surgeons conducted qualitative intraoperative assessment of tumor consistency by using a 5-point scale. Histopathologic diagnosis was confirmed by using the resected specimens. The mean and maximum shear stiffnesses were compared with histopathologic subtypes, and the intraoperative tumor consistency was graded by the surgeons.

RESULTS

The mean and maximum shear stiffnesses were the following: 1.9 ± 0.8 kPa and 3.4 ± 1.5 kPa for meningiomas, 1.2 ± 0.3 kPa and 1.8 ± 0.5 kPa for pituitary adenomas, 2.0 ± 0.4 kPa and 2.7 ± 0.8 kPa for vestibular schwannomas, and 1.5 ± 0.2 kPa and 2.7 ± 0.8 kPa for gliomas. The mean and maximum shear stiffnesses for meningiomas were higher than those of pituitary adenomas (P < .05). The mean and maximum shear stiffnesses were significantly correlated with the surgeon's qualitative assessment of tumor consistency (P < .05). The maximum shear stiffness for 5 firm tumors was higher than that of nonfirm tumors (P < .05).

CONCLUSIONS

MR elastography could evaluate intracranial tumors on the basis of their physical property of shear stiffness. MR elastography may be useful in discriminating firm tumors preoperatively.

Pulsed Laser-Induced Amorphization of Silicon Films

Amorphization of silicon films occurred through homogeneous solidification of molten silicon layers on quartz substrates induced by irradiation with a 30ns-XeCl excimer laser. The crystalline nucleation rate was obtained to be 8×1030m−3s−1. Silicon films were completely amorphized for films thinner than 18nm. Complete amorphizatoin is brought about by reduced grain size and reduced recalescence as the film thickness decreases. Recalescence was observed in situusing transient thermometry with a platinum-temperature-sensing layer when a 15nm-thick silicon film was amorphized.

Pulsed-Laser Annealing of Silicon Films

Phase transition between crystalline and amorphous states was studied through 30ns-pulsed XeCl laser induced melting of silicon films. Crystallization occurs through interface controlled growth for laser energy above surface melting threshold. Grain size is smaller than lOOnm because of short melt duration (<80ns). Amorphization is observed in silicon films thinner than 40nm when the silicon films are completely melted then solidified homogeneously. The amorphized films have a large defect density (∼1020cm-3eV-1), which is remarkably reduced by hydrogen plasma treatment for 1 minute. This paper also discusses the application to fabrication of thin film transistors with a high carrier mobility (>100cm2/Vs) at a low temperature of 250°C.

XeCl Excimer Laser Annealing Used to Fabricate Poly-Si Tfts

Mo-gate n-channel poly-Si TFTs have been fabricated for the first time at a low processing temperature of 26°C. 500 to 1000A thick a-Si:H was successfully crystallized by pulsed XeCl excimer laser (308nm) annealing without heating the glass substrate. The channel mobility of the TFT was 180 cm2/V.sec when the a-Si:H was annealed at energy density of 200 mJ/cm2.

Surgical anatomy of the jugular foramen

The jugular foramen (JF) is a canal that makes communication between the posterior cranial fossa and the upper neck for one third of the cranial nerves and for the main venous channel of the brain. From a lateral view, the JF is protected by multiple layers of muscles and by the outer surface of the petrous bone. Surgical exposure of the JF is usually justified by the removal of benign tumors that grow in this region. In the first part of the present study we describe the surgical anatomy of the JF Then, we detail the relevant points of a stepwise surgical progression of three lateral skull base approaches with a gradual level of exposure and invasiveness. The infralabyrinthine transsigmoid transjugular-high cervical approach is a conservative procedure that associates a retrolabyrinthine approach to a lateral dissection of the upper neck, exposing the sinojugular axis without mobilization of the facial nerve. In the second step, the external auditory canal is transsected and the intrapetrous facial nerve is mobilized, giving more exposure of the carotid canal and middle ear cavity. In the third step, a total petrosectomy is achieved with sacrifice of the cochlea, giving access to the petrous apex and to the whole course of the intrapetrous carotid artery. Using the same dissection of the soft tissues from a lateral trajectory, these three approaches bring solutions to the radical removal of distinct tumor extensions. While the first step preserves the facial nerve and intrapetrous neurootologic structures, the third one offers a wide but more aggressive exposure of the JF and related structures.

Preoperative assessment of vascularity by color Doppler ultrasonography in human rectal carcinoma

PURPOSE

Although angiogenesis assessed by immunostaining endothelial cells (microvessel density) is a well-known prognostic factor in a wide variety of human solid tumors, preoperative determination of microvessel density seems to be difficult in rectal carcinoma. Thus, we performed transanal color Doppler ultrasonography in 46 patients with rectal carcinoma to assess preoperative angiogenic status and compare it with microvessel density in surgical specimens.

METHODS

Time-averaged maximal velocity, peak systolic velocity, number of vascular points, and vascular point index were conducted by color Doppler ultrasonography in 46 patients with rectal carcinoma. Number of vascular points was defined as the number of vessels with pulsation in the section of tumor. Vascular point index was defined as the average number of vascular points divided by the area assessed by color Doppler ultrasonography in the section of tumor. The profiles of number of vascular points were similar to those assessed by microangiography in five rectal carcinomas.

RESULTS

Vascular point index significantly correlated with microvessel density (P < 0.0001). No significant correlation was found between microvessel density and time-averaged maximal velocity or peak systolic velocity. Vascular point index was also a better indicator of lymph node metastasis and venous invasion than microvessel density. In addition, 11 of 46 cases with postoperative hematogenous metastasis (23.9 percent) were observed prospectively. Vascular point index may be a best predictor for hematogenous metastasis from rectal carcinoma compared with peak systolic velocity, time-averaged maximal velocity, and microvessel density by receiver operating characteristic analysis.

CONCLUSION

These results suggest that preoperative quantification of angiogenesis using color Doppler ultrasonography will provide quick and useful information in the management of rectal carcinoma.

Molecular typing and epidemiological study of Salmonella enterica serotype Typhimurium isolates from cattle by fluorescent amplified-fragment length polymorphism fingerprinting and pulsed-field gel electrophoresis

One hundred twenty Salmonella enterica serotype Typhimurium strains, including 103 isolates from cattle gathered between 1977 and 1999 in the prefecture located on the northern-most island of Japan, were analyzed by using fluorescent amplified-fragment length polymorphism (FAFLP) and pulsed-field gel electrophoresis (PFGE) to examine the genotypic basis of the epidemic. Among these strains, there were 17 FAFLP profiles that formed four distinct clusters (A, B, C, and D). Isolates that belonged to cluster A have become increasingly common since 1992 with the increase of bovine salmonellosis caused by serotype Typhimurium. PFGE resolved 25 banding patterns that formed three distinct clusters (I, II, and III). All the isolates that belonged to FAFLP cluster A, in which all the strains of definitive phage type 104 examined were included, were grouped into PFGE cluster I. Taken together, these results indicate that clonal exchange of serotype Typhimurium has taken place since 1992, and they show a remarkable degree of homogeneity at a molecular level among contemporary isolates from cattle in this region. Moreover, we have sequenced two kinds of FAFLP markers, 142-bp and 132-bp fragments, which were identified as a polymorphic marker of strains that belonged to clusters A and C, respectively. The sequence of the 142-bp fragment shows homology with a segment of P22 phage, and that of the 132-bp fragment shows homology with a segment of traG, which is an F plasmid conjugation gene. FAFLP is apparently as well suited for epidemiological typing of serotype Typhimurium as is PFGE, and FAFLP can provide a source of molecular markers useful for studies of genetic variation in natural populations of serotype Typhimurium.

Simultaneous up-regulation of urokinase-type plasminogen activator (uPA) and uPA receptor by hepatocyte growth factor/scatter factor in human glioma cells

Several lines of evidence indicate that hepatocyte growth factor/scatter factor (HGF/SF) and its receptor, c-Met, may play an important role in progression of human glioma. In this study, effects of HGF/SF on urokinase- type plasminogen activator (uPA)-mediated proteolysis network were examined in c-Met-positive human glioma cell lines. Treatment of the glioma cells with various concentrations of HGF/SF resulted in an enhanced secretion of uPA proteins accompanying increased transcription of uPA mRNA in a dose dependent fashion. The levels of uPA receptor (uPAR) mRNAs were also elevated simultaneously upon HGF/SF stimulation, and the cell-surface associated uPA activity was also elevated by the treatment. Since concomitant expression of HGF and its receptor c-Met are frequently observed in malignant gliomas, these results suggest that HGF/SF participates in invasive process of malignant glioma cells not only by its motility-stimulating activity but also through enhanced degradation of the extracellular matrix induced by autocrine activation of uPA proteolysis network.

Cord blood banking: volume reduction using "Procord" Terumo filter

Cryopreserved cord blood (CB) banking, space storage, and ABO major incompatibility transfusion as well as potential progenitor cell loss during processing, are the subjects of this study. We evaluate processing of fresh and thawed CB on "Procord" (Terumo Corp., Japan). On 16 freshed CBs, mean NC, CD34, CFU-GM yields were, respectively, 54% (SD +/- 20), 75% (SD +/- 25), and 171% (SD +/- 168) in a final volume of 20 ml. Final product was enriched in mononuclear cells (mean 69% granulocytes depletion) with reproducible erythrocyte and platelet depletions means of 97% (SD +/- 1.5) and 93% (SD +/- 8). On seven previous whole frozen CB units, Procord gave comparable red blood cell (98%) depletion with 53% (SD +/- 30) mean CD34 recovery. Procord is an efficient method for erythrocyte depletion of CB, and recoveries of NC and progenitor cells are comparable to those obtained with similar processing. Nevertheless, as all existing methods, it is associated with cell and progenitor cell loss.

Expression of emmprin (CD147), a cell surface inducer of matrix metalloproteinases, in normal human brain and gliomas

EMMPRIN (extracellular matrix metalloproteinase inducer), also called CD147, basigin or M6 in the human, is a member of the immunoglobulin superfamily that is present on the surface of tumor cells and stimulates adjacent fibroblasts to produce matrix metalloproteinases (MMPs). In our study, we investigated expression of EMMPRIN in human normal brain and gliomas, since mouse basigin and chicken HT7, the species homologues of human EMMPRIN, are associated with neuronal interactions and normal blood-brain barrier function, respectively. EMMPRIN expression was detected in all samples of non-neoplastic brain and glioma tissues examined. However, expression levels of EMMPRIN mRNA and protein were significantly higher in gliomas than in non-neoplastic brain. Moreover, levels of mRNA expression and immunohistochemical staining correlated with tumor progression in gliomas: They were highest in the most malignant form of glioma, glioblastoma multiforme, followed by anaplastic astrocytoma and then low-grade astrocytoma. Also, immunolocalization revealed quite different distributions in non-neoplastic brain and glioma: EMMPRIN was demonstrated only in vascular endothelium in non-neoplastic regions of the brain, whereas it was present in tumor cells but not in proliferating blood vessels in malignant gliomas. These data indicate that an MMP inducer molecule EMMPRIN is differently expressed in human normal brain and gliomas and could be associated with astrocytoma progression. Possible mechanisms whereby glioma cell EMMPRIN could influence tumor progression will be discussed.

Radiographic and scintigraphic courses of union in cervical interbody fusion: hydroxyapatite grafts versus iliac bone autografts

This study investigated the radiographic and scintigraphic courses of union in cervical interbody fusion using hydroxyapatite (HA) grafts or iliac bone autografts.

METHODS

Twelve patients underwent both serial plain radiography and bone scintigraphy during the 12 mo after surgery. Serial plain radiographs were obtained every month until the end of the study period. Bone scintigrams with 99mTc-hydroxymethylene diphosphonate (HMDP) were obtained at 2 wk and at 1, 2, 3, and 6 mo. Uptake of 99mTc-HMDP in the graft was expressed as a ratio of the counts in the graft to those in the axis.

RESULTS

In the HA graft group, the plain radiographs of all patients showed a radiolucent stripe that disappeared 7.3 +/- 1.5 (mean +/- SD) months after surgery. In the autograft group, a radiolucent stripe around the graft was not seen for any patient, and union was confirmed by follow-up radiographs within 6 mo after surgery. The serial changes in the 99mTc-HMDP uptake ratio showed no difference between the 2 groups. The 99mTc-HMDP uptake ratio peaked 1 mo after surgery and decreased rapidly to a plateau within 2 mo.

CONCLUSION

In the HA graft group, despite the presence of a radiolucent stripe around the graft for more than 6 mo, the scintigraphic course of union was not different from that in the autograft group. The likelihood is that the presence of a radiolucent stripe around the HA graft in the early months after surgery is not always a sign of pseudoarthrosis.

Angiographic cerebral circulation time before and after endovascular therapy for symptomatic vasospasm

AIM

To investigate the correlation between angiographic cerebral circulation time (CCT) and cerebral blood flow (CBF) evaluated by single photon emission computed tomography (SPECT) before and after endovascular treatment for symptomatic vasospasm.

MATERIALS AND METHODS

Seven patients with unilateral vasospasm as demonstrated by catheter angiography who underwent pre- and post-treatment SPECT were selected. All patients had angiographic vasospasm of unilateral middle cerebral artery (MCA). Eight vessels in seven patients underwent intra-arterial papaverine infusion and three vessels underwent percutaneous transluminal angioplasty. Angiographic CCT was defined as the interval from the first image in which contrast medium was visible at the origin of MCA to its disappearance from the cortical arteries in the MCA territory. In SPECT studies, the ischaemic degree in MCA territory was analysed by side to side comparison with calculating the asymmetry index (AI).

RESULTS

The pre-treatment mean CCT was 4.1 +/- 0.8 s. The mean CCT immediately after treatment was 2.7 +/- 0.5 s. In the control subjects (n = 15) with unruptured aneurysm, mean CCT was 3.5 +/- 0.2 s. The pre-treatment mean CCT was significantly prolonged compared with that in the control subjects (P = 0.02). The post-treatment mean CCT was significantly shortened compared with that in the control subjects (P = 0.001). The pre-treatment mean AI was 71.2 +/- 7.4%, and that immediately after treatment was 90.5 +/- 3.6%. AI increased in all territories treated with endovascular treatment; the mean change was 19.3%. Angiographic CCT was closely correlated with AI in both pre- (r = - 0.95) and post-treatment (r = - 0.79).

CONCLUSION

Measurement of CCT is useful in evaluating cerebral haemodynamics of endovascular treatments in patients with cerebral vasospasm.

Glioma cell extracellular matrix metalloproteinase inducer (EMMPRIN) (CD147) stimulates production of membrane-type matrix metalloproteinases and activated gelatinase A in co-cultures with brain-derived fibroblasts

Extracellular matrix metalloproteinase inducer (EMMPRIN) also called CD147, basigin or M6 in the human is a member of the immunoglobulin superfamily that is enriched on the surface of tumor cells and stimulates adjacent stromal cells to produce several matrix metalloproteinases (MMPs). In this study, we have demonstrated that coculturing of EMMPRIN-expressing human glioblastoma multiforme cells (U251) with brain-derived human fibroblasts not only stimulates production, but also activation of pro-gelatinase A (proMMP-2), an enzyme that is enriched in malignant gliomas and most likely crucial to tumor progression. Production of membrane types 1 and 2-MMPs (MT1-MMP and MT2-MMP), which are activators of proMMP-2, was also stimulated in these cocultures. Stimulation of MMP-2, MT1-MMP and MT2-MMP production was inhibited by anti-EMMPRIN monoclonal antibody in a dose-dependent manner. Thus, we have shown, for the first time, that EMMPRIN causes increased expression of MT1-MMP and MT2-MMP, as well as increased production and activation of MMP-2.

A comparison of Escherichia coli O157 isolates from cattle in Japan and the USA by molecular biological methods

Escherichia coli O157 isolates from cattle in Japan (n = 91) and in the USA (n = 415) were compared by pulsed-field gel electrophoresis of endonuclease-cleaved genomic DNA, location of the stx genes and bacteriophage typing. Three isolates from cattle in Japan with high similarity to isolates from cattle in the USA were found. Isolates from cattle farms in Japan and the USA may share a common source.

Unilateral middle cerebral artery stenosis in an adult with Down's syndrome--case report

A 29-year-old male with Down's syndrome presented with severe headache and vomiting. Computed tomography demonstrated subarachnoid hemorrhage. Left carotid angiography showed severe stenosis of the middle cerebral artery 2 cm distal to its origin, as well as abnormal hyper-vascularization near the stenosis site similar to that seen in moyamoya disease. Right carotid angiography showed no abnormalities. However, slight stenosis of the distal part of the bilateral vertebral arteries was noted. There was no aneurysm. We judged that the subarachnoid hemorrhage had been caused by rupture of the moyamoya-like vessel. Some patients with Down's syndrome have anatomical vascular abnormality and vascular fragility. The cerebral vascular abnormality found in this case may be part of the systemic vascular abnormalities associated with Down's syndrome. The vascular changes in some adult patients with Down's syndrome may be a sign of premature aging, and long-term studies with periodic vascular examination of patients with Down's syndrome need to be performed.

Multiple duodeno-jejunal diverticula causing massive intestinal bleeding

A case of massive intestinal blood loss from multiple duodeno-jejunal diverticula is described. A 39-year-old man was referred to our hospital because of recurrent bloody stool and worsening anemia. Upper and lower endoscopy, selective abdominal angiography, and radionuclide scanning were performed to seek the cause of the intestinal bleeding, but none of these studies revealed the source of bleeding. Small-bowel barium follow-through examination showed numerous diverticula in the distal duodenum and proximal jejunum. Excision of the duodenal diverticulum and resection of the involved portion of the jejunum cured the patient. On histopathological examination, an ulcerative lesion with an exposed vessel suggestive of the source of bleeding was seen in the resected duodenal diverticulum. Although duodeno-jejunal diverticula are rare, the importance of a careful search for this malformation in a patient with intestinal blood loss is stressed.

Clonal turnover of enterohemorrhagic Escherichia coli O157:H7 in experimentally infected cattle

A total of 401 enterohemorrhagic Escherichia coli (EHEC) O157:H7 isolates from two experimentally infected calves were analyzed using molecular biological methods. Genetic differences detected by pulsed-field gel electrophoresis were observed between the inoculated and recovered strains as early as 1 day post inoculation. The loss of the inoculated clone was observed in one calf. Replication and dissemination of the EHEC O157:H7 strains that mutated in cattle may result in the diversification of this organism among cattle populations.

Salmonella typhimurium DT104 from livestock in Japan

We examined the distribution of multidrug-resistant Salmonella enterica serotype Typhimurium definitive phage type 104 (DT104) among Japanese livestock from 1973 to 1998. The 144 S. Typhimurium field isolates were tested for susceptibility to ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, tetracycline, kanamycin, trimethoprim, nalidixic acid, and norfloxacin. Thirty-six of 68 strains which exhibited resistance to five or more antimicrobials (ACSSuT+) were identified as DT104. Results of plasmid profiling showed that all DT104 strains retain a 90-kb virulence plasmid, while 20 of 36 strains possessed a few additional small plasmids ranging from 2 to 4 kb. These results showed that DT104 strains have existed in Japanese livestock since 1990, and that this phage type may be an important pathogen for cattle in Japan.

Stresgenin B, an inhibitor of heat-induced heat shock protein gene expression, produced by Streptomyces sp. AS-9

Stresgenin B was isolated as an inhibitor of heat-induced heat shock protein (HSP) gene expression from a culture broth of Streptomyces sp. AS-9 by silica gel chromatography and HPLC. The molecular formula of the novel compound was determined as C11H13NO5 by high resolution FAB-MS analysis, and the structure was determined by UV, 1H NMR, 13C NMR, HMQC, HMBC, and NOESY spectra. Stresgenin B inhibited heat-induced luciferase reporter-gene expression directed by the human hsp70B promoter in Chinese hamster ovary (CHO) cells at concentrations lower than the concentrations for inhibition of dexamethasone-induced luciferase reporter-gene expression directed by the mouse mammary tumor virus (MMTV)-LTR promoter. The inhibition of heat-induced reporter gene expression was evident even when cells were exposed to stresgenin B only during heat stress treatment. Moreover, the compound inhibited heat-induced syntheses of hsp72/73, hsp90, and hsp110 and thereby suppressed the induction of thermotolerance. Stresgenin B showed moderate cytotoxic activities against several neoplastic cell lines and also showed antibacterial activities against Micrococcus luteus, Bacillus subtilis and Staphylococcus aureus strains.

EM2487, a novel anti-HIV-1 antibiotic, produced by Streptomyces sp. Mer-2487: taxonomy, fermentation, biological properties, isolation and structure elucidation

For the purpose of discovering novel agents that inhibit HIV-1 replication at the transcriptional level, we have established cell lines reflecting the HIV-1 long terminal repeat-driven gene expression. Using these cell lines, we have screened approximately 10,000 microorganism products and found that the culture supernatant of Streptomyces sp. Mer-2487 suppresses the HIV-1 Tat-induced gene expression without affecting the basal or tumor necrosis factor-alpha-induced transcription. The purified active component has a unique structure, as shown in Fig. 1. This compound has an inhibitory effect on HIV-1 replication in chronically infected cells as well as acutely infected cells, suggesting that the inhibition occurs at a postintegration step of HIV-1 proviral DNA in the HIV-1 replication cycle.

Salmonella Abortusequi strains of equine origin harbor a 95kb plasmid responsible for virulence in mice

Most Salmonella choleraesuis subsp. choleraesuis serovar Abortusequi strains of equine origin harbor a 95kb plasmid, pSA95. Results of PCR and Southern blot analysis suggest that pSA95 contains spv genes. A pSA95-cured strain of S. Abortusequi was 48 times less virulent to mice than its parental strain. Virulence was restored by reintroduction of pSA95. These results provide clear evidence that pSA95 confers virulence on S. Abortusequi in mice. This is the first report describing a virulence plasmid of S. Abortusequi.

Meningotheliomatous meningioma accompanied by aspergillosis at the skull base

A 73-year-old man was admitted because of right frontal headache and gradual loss of right visual acuity, which had been occurring for 1 year. He had been treated with corticosteroids under the diagnosis of retrobulbar optic neuritis at a nearby clinic. Magnetic resonance imaging (MRI) revealed a nodular lesion at the tuberculum sellae, which showed isointensity on T1-weighted images, iso- to low-intensity on T2-weighted images, and heterogeneous enhancement with Gd-DTPA. Meningioma was diagnosed, and surgery was performed but was limited to biopsy because of intraoperative detection of purulent inflammation of the nodule. Histologic examination revealed aspergillosis in a portion of the meningotheliomatous meningioma. The patient died of meningoencephalitis about 1 month after surgery in spite of extensive treatment with antifungal agents. MRI findings of meningioma and aspergillosis are similar, thus making preoperative diagnosis difficult. However, this case provides evidence that aspergillosis should be included in the differential diagnosis when a skull-base meningioma-like nodule is noted if sinusitis is revealed in the sphenoid sinus.

The shift of genetic subtypes of Escherichia coli O157:H7 isolates from cattle

A total of 46 Escherichia coli O157:H7 isolates were obtained from sequential faecal samples from seven cattle collected over periods of 2 months. Nine closely related genetic subtypes, determined by pulsed-field gel electrophoresis types using three kinds of restriction endonuclease were observed among the isolates. Distinguishable, but closely related genetic subtypes can be isolated from one farm, or from one cow, should be considered when undertaking an epidemiological survey.

Molecular typing of Escherichia coli O157:H7 (H-) isolates from cattle in Japan

A total of 77 Escherichia coli O157:H7 (H-) isolates from cattle in Japan were investigated by molecular biological methods. Most of these isolates (43 isolates) possessed the stx-2 gene, but not stx1. Fifteen bacteriophage types and 50 pulsed-field gel electrophoresis (PFGE) profiles were observed. One isolate was indistinguishable from the human outbreak strain by these methods. This indicates that cattle must be considered as a possible source of human E. coli O157:H7 infection in Japan.

Clinical usefulness of and problems with three-dimensional CT angiography for the evaluation of arteriosclerotic stenosis of the carotid artery: comparison with conventional angiography, MRA, and ultrasound sonography

BACKGROUND

Prevention of stroke is aided by determination of the degree of carotid artery stenosis and progression of arterial sclerosis. Three-dimensional computed tomography (CT) angiography (3D-CTA) is a new method for evaluating the degree of arterial stenosis. The purpose of this study was to compare the accuracy of 3D-CTA with the "gold standard": conventional angiography, magnetic resonance angiography (MRA), and ultrasound sonography (US).

METHODS

A total of 128 carotid bifurcations in 64 patients (42 men and 22 women; mean age, 68.5 years) were examined by 3D-CTA because of symptoms of cerebral infarction, carotid bruit, or findings suggestive of arteriosclerotic carotid artery stenosis on MRA screening. The following were used to compare 3D-CTA with conventional angiography, MRA and US: 1) estimation of the degree of stenosis; 2) depiction of irregularities in arterial walls, including calcification, intimal thickening, ulcers and plaque; and 3) surgical planning for carotid endarterectomy (CEA) and percutaneous transluminal angioplasty (PTA), and postoperative evaluation.

RESULTS

A strong correlation was found between the degrees of stenosis estimated by conventional angiography and 3D-CTA MIP image (r = 0.987/p < 0.0001). On the other hand, stenosis was generally overestimated by MRA, which, however, has the advantage of being able to scan the carotid siphon to the middle cerebral artery at one time. Calcification and ulceration of the artery wall could be evaluated with 3D-CTA, whereas with US, progression of arterial sclerosis could be evaluated by differentiation of homogenous and heterogenous plaque. The anatomical relationships between the site of stenosis and the internal jugular vein and bony structures, which must be known before CEA, were confirmed by observation of rotated images using the shaded surface reconstruction (SSR) method. Because the hemodynamics of cross and collateral flows cannot be clearly imaged with 3D-CTA, standard angiography is needed to determine suitability for bypass surgery.

CONCLUSIONS

The current method used in our hospital for the diagnosis of stenosis of the internal carotid artery includes MRA or US for initial screening, 3D-CTA for evaluation of the degree of stenosis and for preoperative and postoperative evaluation of CEA and PTA, and conventional angiography for evaluation of hemodynamics and determination of the indications for a bypass surgery.

Characterisation of Escherichia coli O157:H7 (H-) derived from cattle using random amplification of polymorphic DNA analysis

One hundred and two isolates of Escherichia coli O157:H7 derived from cattle were characterised by random amplification of polymorphic DNA (RAPD). Four different RAPD profiles were observed. Based on the combined results of RAPD typing and toxin genotyping, the isolates could be divided into six distinct groups.

Effect of intestinal Lactobacillus starter cultures on the behaviour of Staphylococcus aureus in fermented sausage

The effects of Lactobacillus strains isolated from intestinal tracts for starter cultures of fermented sausage on the growth rate and enterotoxin production of Staphylococcus aureus were studied at two fermentation temperatures of 20 degrees C and 35 degrees C. Initial inoculated populations in the sausage batter were approx. 10(4) cfu/g for S. aureus and 10(7) cfu/g for the Lactobacillus strain as a starter culture. Samples of sausage were taken during fermentation and analyzed for pH and microbial populations. In control lots without inoculation of Lactobacillus strains, staphylococcal enterotoxin was detected during fermentation at each temperature. Of three intestinal Lactobacillus strains, L. rhamnosus FERM P-15120 and L. paracasei subsp. paracasei FERM P-15121 inhibited the growth and enterotoxin production of S. aureus in sausages during fermentation at both temperatures, although L. acidophilus FERM P-15119 could not satisfactorily suppress them. The effect of the two selected strains in meat fermentation (i.e., fermentation time, acid production, inhibition of S. aureus) was the same as that of a commercial L. sake starter culture for fermented sausage. These results suggest the intestinal Lactobacillus strains selected in this study could be utilized as a starter culture to produce new fermented meat products that are microbiologically safe.

Application of SPET using technetium-99m sestamibi in brain tumours and comparison with expression of the MDR-1 gene: is it possible to predict the response to chemotherapy in patients with gliomas by means of 99mTc-sestamibi SPET?

Technetium-99m sestamibi (MIBI) is thought to be passively taken up by metabolically active tumour cells and effluxed from them by P-glycoprotein (Pgp). This 170-kDa membrane-bound protein, encoded by the MDR-1 gene, acts as an energy-dependent efflux pump for several antineoplastic agents, resulting in multidrug resistance. For this reason, it is of interest whether the tumour's response to chemotherapy can be predicted by MIBI single-photon emission tomography (SPET). In this study, MIBI SPET was compared with thallium-201 (Tl) SPET using magnetic resonance imaging as a guide in 16 patients with untreated brain tumours [ten glioblastomas (GBs), two anaplastic astrocytomas (AAs), two low-grade gliomas (LGASs) and two metastatic brain tumours) and in four patients who had received treatment for with brain tumours (two GBs, two AAs). In addition, we investigated the expression of the MDR-1 gene and its product Pgp in the same patients, and compared the results with MIBI SPET findings. MIBI, as well as Tl, was highly accumulated and retained in the enhanced region of malignant gliomas. In addition, MIBI SPET yielded sharp and well-contrasted images, and the margin of the tumour was more clearly defined than with Tl SPET due to a good signal-to-noise ratio. Follow-up MIBI SPET in patients who had received therapy showed marked uptake in a patient with malignant transformation, who deteriorated clinically. Patients with no uptake on MIBI SPET showed no sign of recurrence. Semiquantitative analysis of untreated patients showed a relationship between the early uptake index (UI, ratio of average count/pixel in the lesion to that in the contralateral area on early images) and the degree of malignancy (early UI = 1.08+/-0.06 in LGASs, 4.10+/-0.84 in AAs, 5.71+/-3.47 in GBs, and 7.52+/-1.52 in metastatic brain tumours). The retention index (RI, ratio of delayed to early UI) of MIBI was significantly lower than that of Tl in metastatic brain tumours (P<0.05), but not in malignant gliomas. Histological and biological investigation of gliomas showed that the MDR-1 gene and its product Pgp were expressed only in normal endothelial cells and not in tumour cells or proliferating endothelial cells; Pgp tended to decrease as the degree of malignancy rose. Hence, the presence of Pgp and the grade of malignancy were inversely related in gliomas. By contrast, immunohistochemical study showed strong accumulation of Pgp in metastatic brain tumour cells. These histopathological findings and MIBI SPET findings are compatible with experimental data; MIBI was washed out by Pgp. The main cause of chemoresistance is probably not an increasing drug efflux by Pgp in gliomas. Thus, MIBI SPET is useful for detecting the active lesions, but may not be useful for predicting the response to chemotherapy in gliomas.

The effects of sevoflurane anesthesia on insulin secretion and glucose metabolism in pigs

We investigated the effects of two different concentrations of sevoflurane, 0.4 minimum alveolar anesthetic concentration (MAC) and 1.0 MAC, on insulin secretion before, during, and after sevoflurane anesthesia using three successive intravenous glucose tolerance tests (IVGTT) in pigs with indwelling catheters. We also investigated changes in the levels of plasma glucose, catecholamines (epinephrine [E], norepinephrine [NE]), and cortisol (Cor). The pigs were grouped as awake, 0.4 MAC, or 1.0 MAC. Sevoflurane decreased the ratio of insulin/glucose (INS/GLU) in the basal condition (P < 0.05 awake versus 1.0 MAC) and during IVGTT (P < 0.01 awake versus 1.0 MAC and 0.4 MAC). These decreases were quickly reversible (control levels were regained within 2 h of the end of anesthesia), were probably dose-related, appeared not to be mediated by E, NE, or Cor. In addition, the INS/GLU ratio 2.5-4 h after the end of anesthesia was significantly higher in the anesthetized groups than in the awake group. We conclude that sevoflurane anesthesia has a rapidly reversible inhibitory effect on basal and glucose-stimulated insulin secretion, as do other inhaled anesthetics, and might induce insulin resistance.

[Juvenile cerebral infarction with familial hyperlipoproteinemia (a)--case report]

A 34-year-old male with a history of angina pectoris suddenly developed weakness in the right upper and lower limbs, and consulted our hospital. Computed tomography (CT) and magnetic resonance imaging (MRI) suggested cerebral infarction. Cerebral angiography revealed stenosis at the M1 portion of the left middle cerebral artery. Hypertension, diabetes, tobacco or hyperlipidemia were not considered as risk factors for cerebral infarction. The lipoprotein (a) [Lp(a)] level was high. In the present case, medication with a nicotinic acid agent, niceritrol, for hyperlipoproteinemia and low density lipoprotein (LDL) apheresis were performed. Concerning family history, the patient's mother and younger sister had hyperlipoproteinemia. Recent studies have reported that increased Lp(a) levels are an independent risk factor even in cerebral infarction and coronary artery disease. Measurement of Lp(a) levels and treatment for increased Lp (a) levels may be important.

Prediction of incontinence following low anterior resection for rectal carcinoma

PURPOSE

This study was performed to predict incontinence following low anterior resection for rectal cancer.

METHODS

Preoperatively, 21 patients were evaluated via patient history and a physical examination that included anal manometric studies. Six months postoperatively, repeat manometric studies and clinical evaluations were performed to assess the level of continence. Degree of continence was graded based on severity of the dysfunction and grade of the continence score.

RESULTS

The formula used for predicted postoperative resting pressure is as follows: predicted postoperative resting pressure = 0.42 x preoperative resting pressure +1.56 x length of remaining rectum +12.37 (R2 = 0.58; P < 0.001). It was demonstrated that patients with low predicted postoperative resting pressures (< 30 mmHg) had incontinence, and those with high predicted postoperative resting pressures (> 35 mmHg) were continent. There were significant correlations between length of the remaining rectum and ratio of the decrease in maximum resting pressure (postoperative/preoperative maximum resting pressure; r = 0.63; P < 0.01).

CONCLUSIONS

Continence following low anterior resection may be influenced by maximum resting pressure function of the internal anal sphincter; if it is injured during surgery, incontinence will occur. We may be able to foretell incontinence by using the predicted postoperative resting pressure formula, which is calculated by using preoperative resting pressure measurements and then determining the length of the remaining rectum.

Intraoperative squash and touch cytology of chondroid chordoma of the skull base. Report of a case with immunocytochemical and immunohistochemical studies

BACKGROUND

Chondroid chordoma is a rare variant of chordoma and is usually located in the sphenooccipital region. This tumor shows clinical and histologic features common to both conventional chordoma and low grade chondrosarcoma and has a better prognosis than either of those lesions. To our knowledge, there has been no English language report describing its cytologic features.

CASE

The cytologic features of skull base chondroid chordoma observed in intraoperative crush and touch preparations from a 33-year-old female are reported. Touch cytology revealed round or stellate cells distributed in a mucoid background without a typical epithelial cordlike arrangement. The cells had variably vacuolated cytoplasm and round or oval nuclei and showed slight cellular pleomorphism. May-Giemsa staining was superior to Papanicolaou staining in demonstrating the mucoid matrix and vacuolated cytoplasm of the tumor cells. Additionally, crush preparations were effective in demonstrating well-differentiated chondroid elements. Immunocytochemistry with positivity for S-100 protein and cytokeratins was an essential adjunct in the cytologic diagnosis of chordoma and helped in distinguishing it from other chondrogenic tumors.

CONCLUSION

It is possible and advantageous to diagnose chondroid chordoma with a combination of cytologic and immunocytochemical studies of intraoperative crush and touch preparations in conjunction with clinical and radiographic information.

Evaluation of indicators of tissue hypoxia during progressive hemorrhage and blood retransfusion

To establish whether the indicators of oxygen metabolism reflects the improvement in tissue oxygenation during therapy, twelve rabbits subjected to progressive hemorrhage followed by retransfusion were studied. The changes in oxygen delivery (DO2), oxygen consumption (QO2), oxygen extraction ratio (O2ER), arterial lactate concentration, venous-arterial difference in PcO2 (v-aDPcO2) and arterio-venous difference in pH (a-vDpH) were analyzed during two phases (above and below) the critical DO2 with the regression coefficient (slope). The main findings during the transfusion were: a) the slope, when compared during the two phases was not significantly different for O2ER, v-aDPcO2 or a-vDpH, while during hemorrhage each variable showed a significantly different slope, b) in the phase below the critical DO2, the slope was significantly less steep than that during hemorrhage for lactate and v-aDPcO2, c) in the phase above the critical DO2, lactate alone had significantly steeper slope than that during hemorrhage. In conclusion, it is suggested that the changes in QO2 best reflect the recovery from tissue hypoxia.

[Enzyme saturation of sevoflurane in piglets at clinically-used concentrations]

To investigate if sevoflurane saturates the metabolic capacity of the enzymes responsible for sevoflurane at clinically-used concentration ranges, we compared plasma fluoride levels and urinary excretion of inorganic fluoride in piglets after (1) low concentration sevoflurane anesthesia versus (2) high concentration sevoflurane anesthesia. Eleven male piglets, weighing 18-23.5 kg, were randomly divided into two groups: 1) L group: five animals were anesthetized for two hours with sevoflurane at 0.8% end-tidal concentration (0.4 MAC); 2) H group: six animals were anesthetized for two hours with sevoflurane at 3.0% end-tidal concentration (1.4 MAC). Plasma inorganic fluoride levels, blood sevoflurane concentration, urinary inorganic fluoride concentration and urine volume were measured. The blood sevoflurance concentration in both groups reached their plateau levels 30 min after the start of anesthesia. The plateau levels in the H and L groups were 275-306 microM and 105-115 microM, respectively. The plasma fluoride concentrations reached plateau levels 60 min after the start of anesthesia in both groups. The H group showed significantly higher plasma fluoride levels than the L group during sevoflurane anesthesia. The H group also showed significantly higher urinary excretion of inorganic fluoride than the L group. Therefore, metabolite production levels in the H group were significantly higher than the L group. These results suggest that low concentration sevoflurane anesthesia did not saturate the metabolic capacity of the enzymes responsible for defluorination of sevoflurane in piglets.

Relationship of inspired anesthetic concentration to plasma concentration and urinary excretion of sevoflurane metabolites in rats

In patients, plasma concentrations of sevoflurane metabolites may be independent of inspired sevoflurane concentration over a defined dose range. In contrast, studies using rabbits have found that plasma concentrations and urinary excretion of fluoride ion are dose-dependent up to 3% inspired sevoflurane. We measured sevoflurane metabolite concentrations in adult male Sprague-Dawley rats and related them to inspired sevoflurane concentrations. When plasma concentrations and urinary excretion of metabolites were measured in vivo, they were dependent on inspired anesthetic concentration at concentrations less than 1.25%, but became less dose-dependent at higher anesthetic concentrations. Sevoflurane metabolism by precision-cut liver slices in vitro became dose-independent at more than 10-30 microM sevoflurane. No evidence of substrate inhibition was observed. These data provide evidence that sevoflurane metabolite concentrations are almost independent of inspired anesthetic concentration over at least part of the clinically used concentration range.

The correlation of thymidine phosphorylase activity with the expression of interleukin 1 alpha, interferon alpha and interferon gamma in human colorectal carcinoma

Thymidine phosphorylase (dThdPase) is an angiogenic enzyme and seems to be related to an angiogenesis in human colorectal carcinoma. The incidence of dThdPase-positive cells was significantly correlated with microvessel count in 21 human colorectal carcinomas. Interleukin 1 alpha (IL-1 alpha), tumor necrosis factor alpha (TNF-alpha), interferon alpha (IFN-alpha) interferon gamma (IFN-gamma) induce dThdPase activity in human cancer cell lines. To study whether this phenomenon occurs in the human colorectal carcinomas, we examined the correlation between dThdPase activity and the expression levels of IL-1 alpha, TNF-alpha, IFN-alpha and IFN-gamma in colorectal carcinoma tissues. dThdPase activity was assayed by the methods of Friedkin and Robert, and the expression level of IL-1 alpha, TNF-alpha, IFN-alpha and IFN-gamma was determined by ELISA. dThdPase activity was significantly correlated with the amount of IL-1 alpha (n = 19, r = 0.347, P = 0.0001), INF-alpha (n = 18, r = 0.717, P = 0.008), and IFN-gamma (n = 4, r = 0.9777, P = 0.0234) in human colorectal carcinomas. However, the dThdPase activity was not correlated with the amount of TNF-alpha (n = 21, r = 0.235, P = 0.2682). These results suggested that the expression levels of IL-1 alpha, IFN-alpha and IFN-gamma are correlated with dThdPase activity in human colorectal carcinomas and that these cytokines may cause angiogenesis by inducing the expression of dThdPase.

[Effects of allopurinol on renal damage following renal ischemia]

We investigated the effects of allopurinol on renal damage following renal ischemia. Male Wistar rats weighing 250-300 g were classified into enflurane and allopurinol groups and anesthetized for 5 minutes using 1.7 MAC of enflurane in 30% oxygen. Then the left renal artery was dissected and clamped. Arterial occlusion was performed under 1.3 MAC enflurane for 30 minutes. Anesthesia was maintained for an additional 90 minutes after releasing the clip. In the allopurinol group, the rats were administered with allopurinol 3 mg.kg-1 intravenously prior to renal ischemia. At the end of anesthesia and 24 hours after the discontinuation of anesthesia, the necrotic areas, kidney weight/body weight ratios, gamma-GTP and NAG activities of the kidney which had been clamped were examined. Urinary gamma-GTP and NAG activities and serum inorganic fluoride concentrations were also measured. The necrotic area was significantly smaller in the allopurinol group than in the enflurane group. The activity of gamma-GTP in the kidney was higher in the allopurinol group than in the enflurane group. The kidney weight/body weight ratio was lower in the allopurinol group than in the enflurane group. There was no difference in serum inorganic fluoride concentration between the allopurinol and enflurane groups. These results suggest that allopurinol decreases renal damage following renal ischemia under enflurane anesthesia.

The effects of inhalational anesthetics on ischemic injury of rat kidney with renovascular occlusion

The effects of halogenated inhalational anesthetics, viz. halothane, enflurane, isoflurane and sevoflurane, on ischemic rat kidneys were studied through the response of renal gamma-glutamyl transpeptidase in the brush border of proximal tubules to monoclonal antibodies. Brush border staining characteristics were evaluated as follows: a) continuous (normal), b) discontinuous (damaged) and c) indistinct (necrotic). The isoflurane group had significantly fewer damaged and/or necrotic proximal tubules compared to the other groups. These results suggest that isoflurane is the most appropriate inhalational anesthetic when renal circulation is impaired.

[Hepatotoxicity of halogenated inhalational anesthetics studied in rats hepatocytes]

Effects of 2% halothane, 1.5% sevoflurane, 1.5% enflurane, and 1.2% isoflurane on hepatic dysfunction were studied using rat hepatocytes incubated in media containing 95% or 5% O2. The effects of anesthetics on hepatic perfusion were eliminated by incubation of hepatocytes for 45 minutes with each combination of anesthetic and oxygen concentration. After incubation, viability of hepatocytes was assayed by the LDH latency test. Enzyme (GPT, GOT, LDH) activities, lactate concentration and pyruvate concentration in the incubation medium were measured. The concentrations of adenine nucleotides and inorganic phosphorous in the liver were determined. Anesthetics administered in 95% O2 did not produce significant decreases in viability and enzyme release compared to 95% O2 alone. Halothane, sevoflurane, and isoflurane administered in 5% O2 produced significant decreases in viability and enzyme releases compared to 95% O2 alone. In groups administered 95% O2 there was a significant relationship between viability and energy charge in hepatocytes (P < 0.01). In the 5% O2 groups, there were significant relationships between viability and ATP in hepatocytes (P < 0.01) or L/P ratio in incubation medium (P < 0.01). These results suggest that the combination of anesthetics and hypoxia produce hepatotoxicity. Destruction of energy status might be the cause of hepatotoxicity.

A conjugative plasmid pTE195 coding for drug resistance and virulence phenotypes from Salmonella naestved strain of calf origin

Salmonella naestved strain AHI-195, of calf origin, harbors a conjugative 95 megadalton (MDa) plasmid, pTE195, which encodes resistance to tetracycline and chloramphenicol and belongs to incompatibility group FII. Moreover, DNA homology between pTE195 and the Salmonella dublin virulence plasmid pTE800 was revealed by digestion with several restriction endonucleases and confirmed by hybridization with different specific probes. These results indicate that pTE195 carries not only genes for drug resistance but also genes for virulence phenotypes such as serum resistance and mouse lethality.

5-S-cysteinyldopa in urine and tumors

1) The urinary 5-S-CD contents in malignant melanoma subjects (n = 135) and non-melanoma subjects (n = 204) were measured by HPLC. These results suggest that, as a biochemical marker, periodic measurement of urinary 5-S-CD is quite useful for evaluating the determinations of stage classification (UICC, 1987), and the detection of metastases, the therapeutic efficacy of operation or immunochemotherapy against malignant melanoma. 2) Quantitative analyses of 5-S-CD values in tissues from primary malignant melanoma lesions (n = 24) and pigmentary tumors other than melanomas (n = 136) showed 80.6-821.4 ng/mg and N.D.-55.0 ng/mg respectively. In view of the above findings, it was suggested that the pigmentary tumors can be diagnosed as malignant melanoma if the 5-S-CD value in the tissues is higher than 100 ng/mg.