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.

[The combined petrosal approach. Anatomical principles, surgical technique and indications]. / La pétrectomie combinée Bases. anatomiques, technique chirurgicale et indications.

Management of large petroclival tumors requires the use of extensive surgical approaches that usually jeopardize the intrapetrous neuro-otologic structures. To confirm the interest of the combined petrosal approach in this indication, we describe the relevant anatomy and the surgical steps of this procedure. After making a periauricular skin incision and muscle elevation, an occipitotemporal bone flap is shaped. Then a retrolabyrinthine exposure is undertaken, with optimal skeletonization of the semicircular canals. Around the internal auditory canal, the retromeatal area and the petrous apex are resected. The retrosigmoid dura is opened followed by the incision of the subtemporal and posterior fossa dura along the superior petrosal sinus. The sinus is coagulated and divided. The tentorium is sectioned transversally toward its free edge behind the porus of the trochlear nerve. The combined petrosal approach is able to provide a wide multidirectional corridor toward the ventral surface of the pons, the basilary trunk and the ipislateral cranial nerves from the oculomotor to the lower cranial nerves. This study confirms that despite a significant extra time needed for proper achievement, the combined petrosal approach is a valuable conservative approach when the petroclival area, ventral brain stem and basilary trunk are targeted. This approach should be included in the panel of the transpetrous routes available by expert skull base teams.

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.

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.

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

UNLABELLED: 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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.