Mm In Maximum Diameter Research Articles

Development of a histological pseudocapsule and its use as a surgical capsule in the excision of pituitary tumors

The presence of a histological pseudocapsule around pituitary tumors was noted in the early 1900s. Since that time there has been no emphasis on the sequence of the stages of its development or on the relationship between these stages and the capacity to identify very small pituitary tumors at surgery in patients in whom preoperative imaging has been nondiagnostic. In addition, limited emphasis has been given to the pseudocapsule's use for selective and complete resection of pituitary adenomas. The development of the pseudocapsule was examined by performing histological analysis of portions of pituitary glands removed during 805 operations for Cushing disease. Twenty-five adenomas, each measuring between 0.25 and 4 mm in maximum diameter, were detected in the excised specimens; 17 were adenocorticotropic hormone-positive adenomas and eight were incidental tumors (four prolactin-secreting and four nonsecreting lesions). In 16 tumors the size of the adenoma could be established. The distribution of tumor size in relation to the presence of a histological pseudocapsule indicates a transition from the absence of a reticulin capsule (tumor diameter < or =1 mm) through the initial compression of surrounding tissue (tumor diameter 1-2 mm) to the presence of a multilayered reticulin capsule observed when adenomas become larger (tumor diameter 2-3 mm). The absence of a reticulin capsule in cases of very small tumors may contribute to limited localization of these lesions during surgical exploration of the pituitary gland. In this article the authors describe surgical techniques in which the histological pseudocapsule is used as a surgical capsule during pituitary surgery. In their experience, recognition of this surgical capsule and its use at surgery has contributed to the identification of microadenomas buried in the pituitary gland, aided the recognition of subtle invasion of the pituitary capsule and contiguous dura mater, and enhanced the consistency of complete tumor excision with small and large tumors.

Randomized, Placebo-Controlled, Esophageal Squamous Cell Cancer Chemoprevention Trial of Selenomethionine and Celecoxib

Esophageal squamous cell carcinoma remains a leading cause of cancer death worldwide. Squamous dysplasia, the accepted histological precursor for esophageal squamous cell carcinoma, represents a potentially modifiable intermediate end point for chemoprevention trials in high-risk populations. We conducted a randomized, controlled trial of selenomethionine 200 microg daily and/or celecoxib 200 mg twice daily (2 x 2 factorial design) among residents of Linxian, People's Republic of China. Subjects had histologically confirmed mild or moderate esophageal squamous dysplasia at baseline. Esophagogastroduodenoscopy was performed before and after a 10-month intervention. Per-subject change (regression, stable, or progression) in the worst dysplasia grade was defined as the primary end point. Results were compared by agent group (selenomethionine vs placebo; celecoxib vs placebo). Two hundred sixty-seven subjects fulfilled all eligibility criteria, and 238 (89%) completed the trial. Overall, selenomethionine resulted in a trend toward increased dysplasia regression (43% vs 32%) and decreased dysplasia progression (14% vs 19%) compared with no selenomethionine (P = .08). In unplanned stratified analyses, selenomethionine favorably affected a change in dysplasia grade among 115 subjects with mild esophageal squamous dysplasia at baseline (P = .02), but not among 123 subjects with moderate esophageal squamous dysplasia at baseline (P = 1.00). Celecoxib status did not influence changes in dysplasia grade overall (P = .78) or by baseline histology subgroup. After a 10-month intervention, neither selenomethionine nor celecoxib inhibited esophageal squamous carcinogenesis for all high-risk subjects. However, among subjects with mild esophageal squamous dysplasia at baseline, selenomethionine did have a protective effect. Although it is based on unplanned stratified analyses, this finding is the first report of a possible beneficial effect for any candidate esophageal squamous cell carcinoma chemopreventive agent in a randomized controlled trial.

Isolated recurrence at the residual uterine cervix after abdominal radical trachelectomy for early cervical cancer

Background. We report an isolated recurrence at the residual cervix shortly after abdominal radical trachelectomy for cervical cancer. Case. A 34-year-old woman underwent radical abdominal trachelectomy and pelvic lymphadenectomy for FIGO stage IB1 squamous cell cervical cancer. The tumor measured 10 mm in maximum diameter with 4 mm of invasion. Histology showed lymph vascular space involvement with no infiltration of adjacent structures and no pelvic lymph node metastases. Tumor-free resection margins exceeded 15 mm. At the 6-month follow-up examination, cervical cytology showed cells suspicious for recurrent cervical cancer. Abdominal hysterectomy was performed and histology showed an isolated 3-mm recurrence in the residual cervix. The patient is free of disease 8 months after hysterectomy. Conclusion. Recurrence at the residual cervix is a potential risk of abdominal trachelectomy for early cervical cancer. Patients should be counseled accordingly and followed closely.

Forensic Discrimination of Sheet Glass by a Refractive-Index Measurement and Elemental Analysis with Synchrotron Radiation X-ray Fluorescence Spectrometry

Measurements of the refractive index (RI) and elemental analysis using synchrotron radiation X-ray fluorescence spectrometry (SR-XRF) were applied to the forensic discrimination of sheet-glass samples from different origins. The refractive index was calculated from the matching temperature at which the glass fragments became invisible in silicone oil. Fragments smaller than 1 mm in maximum diameter were taken from each of 11 sheet glasses and subjected to analysis by SR-XRF. The XRF spectrum of these samples indicated that a comparison of 6 elements (Ca, Fe, Sr, Zr, Ba and Ce) was useful for the discrimination of sheet glasses. Cluster analysis was performed using 33 sets of SR-XRF data obtained by triplicate measurements for the 11 glasses. Comparing 528 pairs among 33 samples, 515 pairs could be correctly discriminated. The number of indistinguishable pairs could be reduced from 36 to 4 by comparing the SR-XRF data. Elemental analysis by SR-XRF could provide small glass fragments with a more evidential value than the solely measurement of only RI, through a significant improvement of the discrimination capability.

MDCT Urography of Upper Tract Urothelial Neoplasms

The purpose of our study was to review the MDCT urography appearance of pathologically proven transitional cell carcinomas of the renal collecting system and ureter and to correlate the MDCT urography findings with pathology findings. Of 370 MDCT urography examinations performed over an 18-month period, 18 patients were diagnosed with 27 renal collecting system or ureteral urothelial neoplasms at endoscopic biopsy (n = 8) or surgery (n = 19). Initial MDCT reports were reviewed to determine the sensitivity of original reviewers in detecting these neoplasms. Two radiologists also retrospectively reviewed these scans and characterized the CT appearance of the neoplasms on both axial CT and 3D reformatted images. Findings at retrospective review were correlated with pathology results to determine whether any CT features could be used to predict tumor grade. Eighteen of 27 neoplasms were prospectively identified on MDCT urography, and an additional six neoplasms were detected on retrospective review. Three ureteral neoplasms could not be visualized. The 24 retrospectively detected neoplasms had three distinct MDCT appearances: circumferential urothelial wall thickening (n = 14), small masses (> 5 mm in maximal diameter) (n = 5), and large masses (> 5 mm in maximal diameter) (n = 5). All detected lesions could be seen on axial excretory phase images provided wide window settings were reviewed; however, only six were detected on 3D reconstructions. MDCT urography appearance did not correlate with tumor grade. MDCT urography is a promising technique for detecting upper urinary tract neoplasms. The static 3D reconstructions used in this study are insufficient for visualization. Axial image review remains essential for tumor identification.

Concurrent chemoradiotherapy using low-dose continuous infusion of 5-fluorouracil for postoperative regional lymph node recurrence of esophageal squamous cell carcinoma

Radiotherapy plays an important role in salvaging patients who suffer locoregional recurrence; however, it displays poor prognosis. Because concurrent chemoradiotherapy offers superior treatment results compared to radiotherapy alone in patients with localized esophageal cancer, to improve survival rates, we treated patients displaying postoperative regional lymph node recurrence of esophageal squamous cell carcinoma using radiotherapy combined with protracted low-dose continuous infusion of 5-fluorouracil (5-FU). Between January 1992 and December 2001, 14 patients with postoperative regional lymph node recurrence of esophageal squamous cell carcinoma were treated with concurrent chemoradiotherapy. Radiotherapy was delivered at 1.8–2.0 Gy/day, for a total dose of 56–70 Gy (median, 60 Gy). Chemotherapy was administered 5 days/week as continuous infusion of 5-FU (250–300 mg/m2) for at least 5 weeks. Median follow-up time was 27 months. Twelve patients demonstrated partial response, and 2 patients displayed stable disease. Response rate was therefore 86% (12/14). In-field recurrence occurred in 3 patients. Involved lymph nodes that recurred in the irradiation field were ≥40 mm in maximum diameter and invaded into the surrounding normal tissues. Local progression-free rate at 2 years was 72%. As an initial failure, 6 patients displayed out-field recurrence. Disease progression-free rate at 2 years was 42%. Overall survival rates at 1 and 2 years were 85% and 57%, respectively. Concurrent chemoradiotherapy using low-dose continuous infusion of 5-FU was effective for patients with postoperative regional lymph node recurrence of esophageal squamous cell carcinoma. Close follow-up is crucial, and further investigation is required to prevent out-field recurrence.

Gastric duplication cyst: A rare endosonographic finding in an adult

Cystic lesions located in the gastric wall are a rare finding in endosonography of the gastrointestinal tract. Compared to all forms of benign and malignant tumours of the stomach, gastric duplication cysts are an uncommon anomaly – especially in adults. We report on a 59-year-old woman suffering from intermittent abdominal pain, weight loss and nausea. A gastric duplication cyst was identified by endoscopic ultrasound (EUS), but malignancy was excluded by EUS and fine-needle aspiration histology. Because of continuously increasing abdominal complaints, surgery was performed with partial resection of the gastric corpus and splenectomy. Gross anatomy and histology showed a gastric cyst measuring 150 mm in maximum diameter with no evidence of malignancy or inflammation. Following surgery, the patient's condition recovered fully.

SLOW VERSUS FAST SHOCK WAVE LITHOTRIPSY RATE FOR UROLITHIASIS: A PROSPECTIVE RANDOMIZED STUDY

We determined the effect of shock wave lithotripsy (SWL) rate on treatment outcome in patients with renal and ureteral stones. A total of 156 patients were prospectively randomized to receive SWL using a slow (60 pulses per minute) or fast wave rate (120 pulses per minute). Inclusion criteria were patients with a single radiopaque renal or ureteral stone not exceeding 30 mm in maximum diameter. Patient characteristics, stone and therapy features were reviewed, and the relation to success rate and total number of shock waves required was assessed using the chi-square, Fisher exact and Mann-Whitney tests. Factors proven to be significant in univariate analysis were entered in a multivariate logistic regression analysis. The study included 114 male (73.1%) and 42 female (26.9%) patients with a mean age +/- SD of 42.1 +/- 13.3 years. Stone length measured in maximum diameter was 13.2 +/- 5.9 mm (range 5 to 30). Renal stones were encountered in 94 (60.3%) patients and ureteral stones in 62 (39.7%). The slow SWL rate was used in 76 (48.7%) patients and the fast rate in 80 (51.3%). Baseline variables were comparable in both groups. However, the total number of shock waves required was statistically significantly lower in the slow rate group (p = 0.004) and the treatment time was significantly longer (p = 0.000). The rate of success, defined as being completely stone-free or having clinically insignificant gravel less than 2 mm, was significantly higher with the slow rate (p = 0.034), an increased number of sessions (p = 0.001), decreased stone length (p = 0.000) and greater total number of shock waves (p = 0.011). However, only the slow SWL rate and stone length maintained a statistically significant impact in multivariate analysis. The slow SWL rate is associated with a significantly higher success rate at a lower number of total shock waves compared to the fast SWL rate.

Mucin phenotypic expression and p53 gene abnormality of gastric super-minute well-differentiated adenocarcinoma: Re-evaluation with relationship between histogenesis of well-differentiated adenocarcinoma and intestinal metaplasia in distal stomach

BackgroundAlthough the gastric well-differentiated adenocarcinoma in the distal stomach has been thought to develop via a intestinal metaplasia-carcinoma sequence, there are some disproofs from new mucin examinations for minute-size lesions in same type carcinoma. The current study was performed and pointed out the new findings for the solution to the problem according to the point described above.Methods12 super-minute lesions (less than 1 mm in maximum diameter) of well-differentiated adenocarcinoma in distal stomach (SMCa), which were detected from the pathological examinations of 210 surgically resected stomach specimens, and the mucosa adjacent to these carcinoma lesions, were examined by immunohistochemical mucin stainings (MUC2 and CD-10: intestinal phenotype, 45M1 and MUC6: gastric phenotype) and p53-overexpression. And the analyses of the replication error of the microsatellites in chromosome 17 related p53 gene (TP53 and D17S786) (RER-p53MS) were performed in SMCa lesions, adjacent mucosa to each lesion and other gastric mucosa with intestinal metaplasia, because all SMCa lesions showed p53-overexpression immunohistochemically, decribed below.Results1. The carcinoma cells in all SMCa lesions were positive for 45M1 and p53. On the other hand, no positive carcinoma cells for MUC6 were seen although the pyloric glands and the remnant pyloric gland in the SMCa lesions in the same slides were positive for MUC6. Ten lesions (83%) had intestinal phenotypic mucin (10 lesions: MUC2 (+), 4 lesions: CD10 (+)). Two lesions (17%) were positive for only 45M1 (gastric phenotypic mucin). 2. All of the mucosa adjacent to SMCa showed intestinal metaplasia (complete type: 7 regions, incomplete type: 5 regions). 3. RER-p53MS was confirmed in 42% (5/12 regions) of SMCa, in 42% (5/12 regions) of the mucosa adjacent to SMCa and 14% (6/42 regions) of the other intestinal metaplasia mucosa.ConclusionMost of the super-minute well-differentiated adenocarcinoma lesions in the distal stomach, which had both gastric and intestinal phenotypic mucin, are considered to develop from the tubular proliferative zone with the incomplete type of the intestinal metaplasia and p53 gene abnormality, while a part of them, which had only gastric phenotypic mucin, may derive from the gastric native tubules (non-metaplastic epithelium) with p53 gene abnormality.

PATHOLOGICAL AND MOLECULAR‐BIOLOGICAL STUDIES ON SEQUENCE FROM REFLUX ESOPHAGITIS TO DEVELOPMENT OF BARRETT's ADENOCARCINOMA

Background: Barrett's adenocarcinoma is considered to develop via a dysplasia‐carcinoma sequence. However, this theory is thought to be incomplete, because the reports supporting it have been led by an investigation using relatively large‐sized neoplasias or biopsy materials. We think that the minute‐sized neoplasias and the propria mucosa adjacent to these lesions must be examined histologically to clarify the histogenesis of digestive tract carcinoma. In the present study, new findings on the histogenesis of Barrett's adenocarcinoma were revealed according to this point described above.Methods: First, Barrett's epithelium (in particular, specialized colmunar epithelium: SCE) was investigated histologically and immunohistochemically. Second, 28 lesions of the super‐minute tubular neoplasia within 1 mm in maximum diameter in Barrett's esophagus (SMBa) were detected by pathological examinations, and loss of heterozygosity of microsatellite markers (TP53, D17S796 and D17S786) in chromosome 17‐related p53 (p53‐LOH) in these SMBa lesions were examined by DNA extraction using microdissection and high resolution fluorescence labeled PCR primers.Results: Histological and immunohistochemical findings showed that the tubules of SCE had a three‐layer structure and typical SCE should be thought to be the large bowel‐type of the intestinal metaplasia (or goblet cell metaplasia) in the cardiac gland mucosa. According to the overexpression of p53 protein labeling index (p53‐LI), the SMBa lesions were divided into two groups. Three lesions with p53‐LI over 90%, which were thought to be intramucosal adenocarcinoma morphologically, showed high frequency of p53‐LOH (loss of heterozygosity) (100%), and 25 lesions with an average p53‐LI of 58%, which were thought to be benign neoplasia morphologically, also showed p53‐LOH (36%).Conclusions: SCE is thought to be the large bowel type of the intestinal metaplasia in the cardiac gland mucosa. Pathological and molecular‐biological findings of SMBa in SCE supports the dysplasia‐carcinoma sequence in the histogenesis of Barrett's cancer and synchronously some SMBa suggests that there is a different route, the so‐called de novo carcinoma theory.

Current concepts of endovascular aneurysm treatment, and about the role of stents for endovascular repair of cerebral arteries

Within the last 15 years, image-guided minimally invasive endovascular treatment for ruptured or un-ruptured cerebral aneurysms has surpassed surgical treatment for a subset of aneurysms, as shown in recent large randomised trials (ISAT, ISUIA). Endovascular patient care occurs at equal or lower cost than surgery. Cerebral aneurysms are of variable pathogenesis and by far the largest group consists of saccular aneurysms formed at proximal cerebral vessel bifurcations. Likely based on a focal vessel wall weakness, fragile out-pouchings typically develop in areas of high shear stress and at areas of the vessel tree where there is higher intravascular pressure, i.e. along the proximal intracranial branching of the internal carotid artery and less frequently of the vertebro-basilar system. Initiation, growth and rupture of an aneurysm are likely driven by a combination of several factors, each contributing to a variable degree in each of the evolutionary steps of an aneurysm's history. Current treatment modalities include for open surgical treatment various techniques to reconstruct the artery (clips) or to reinforce the aneurysm wall (wrapping) or to bypass circulation of the vessel carrying an aneurysm (aneurysm trapping and bypass surgery). Less invasive, endovascular treatment techniques have been based on the principles of aneurysm filling with coils or polymers or vessel occlusion (aneurysm trapping). More recently, vessel reconstruction with stents rather than aneurysm filling has been advocated as treatment (Lylyk et al., J Neurosurg 2002;97: 1306-13). Both coils and stent techniques aim to induce slowing of blood flow and initiation of thrombosis within the aneurysm. Secondary vessel wall repair with scar tissue occurs within weeks. With small vessel wall defects (focal defects, usually less than 3-4 mm in maximum diameter), coil implantation seems to allow successful repair under this principle, provided that the lumen of the aneurysm pouch is suitable for coil introduction. With larger vessel wall defects in proportion to the vessel diameter (segmental defects), either the vessel must be occluded if tolerated by the patient, or the vessel is reconstructed with the use of stent implants. Based on initial clinical experience, stents seem to offer advantages over coils alone in the endovascular repair of segmental arterial wall defects. However, more research is required to better understand this stent function and to adapt stent technology to the new role it is asked to play in the intracranial circulation: repairing vessels with an aneurysm rather than opening a stenosis as typically requested in coronary or peripheral vessels. The following text is an update on current concepts and treatment, and how medical informatics is about to influence patient management by better lesion understanding, treatment simulation, implant design and medical engineering.

Efficacy of Endoscopic Mucosal Resection with Suction in the Treatment of Gastric Adenoma

Efficacy of Endoscopic Mucosal Resection with Suction in the Treatment of Gastric Adenoma Jae G. Kim, Hyung Joon Kim, Bong Gi Cha, Jae Hyuk Do, Sae Kyung Chang, Sill Moo Park Endoscopic mucosal resection with suction (EMR-S) is an established treatment option for gastric adenoma. The EMR-S is broadly divided into 2 categories by technical aspect, which are endoscopic mucosal resection with ligator device (EMR-L) and endoscopic mucosal resection with cap-fitted endoscope (EMR-C). The aim of this study was to clarify the efficacy and limitation of EMR-S for the resection of gastric adenoma.Methods: To compare the EMR-L and EMR-C, we studied the size of lesion, location, macroscopic finding and complete resection (CR) rate according to resection technique. Between June 1996 and June 2003, 32 gastric adenomas in 27 patients that were diagnosed by endoscopic biopsy were resected with EMR-S. The patients were classified into three groups, which were EMR-L (n=16), EMR-C with single channel endoscope (EMR-C1, n=9) and EMR-C with double channel endoscope (EMR-C2, n=7). Results: Overall complete resection rate of EMR-S was 90.6% (29/32). Two of 3 incomplete resected cases were vertically invaded to submucosal layer. The other case was laterally invaded. CR rate according to location was lowest in the post-wall side of body. No difference of CR rate was noted with regard to the macroscopic finding. The average size of the resected specimens were 8.5 6 3.9 mm in EMR-L, 12.5 6 3.2mm inEMR-C1 and 15.06 6.0mm inEMR-C2. The size of resected specimens was significantly larger in EMR-C2 than EMR-L and EMR-C1 (p<0.05). No serious complication was encountered. Conclusion: EMR-S is effective and safe for the treatment of gastric adenoma. The lesions less than 21mm in maximal diameter can be resected by EMR-C2. *M1805 Metastatic Tumors to the Stomach: Analysis of 83 Patients Diagnosed by Endoscopy Noriko Sakemura, Takuji Gotoda, Takahisa Matsuda, Hisanao Hamanaka, Ichiro Oda Background: Metastases to the gastrointestinal tract are considered unusual site for malignant tumors. There have been a few published reports on metastatic lesions to the stomach about endoscopic findings. We investigated endoscopic features of metastatic tumors to the stomach from distant sites. Patients and Method: We used retrospectively entered database (from 1968 to 2002) to identify all patients with metastatic tumors to the stomach, which were detected endoscopically at the National Cancer Center Hospital in Tokyo. Patients with leukemia, malignant lymphoma with gastric involvement, or gastric invasion directly from neighboring organs, were excluded from this study. Results: The primary sites were as followings; lung (18cases, 22%), malignant melanoma (17cases, 20%), breast (16cases, 19%), esophagus (16cases, 19%), and the others (head and neck; 4, ovary; 3, uterus; 2, testis; 2, biliary tract; 1, kidney; 1, and unknown; 3). Among 83 cases with metastatic tumors to the stomach, 49 cases (59%) had solitary gastric lesion and the rest 34 cases had multiple lesions (41%). Seventy-six cases (92%) of the metastatic tumors were located in the middle or upper third of the stomach. In the endoscopic appearance, 41 patients had lesions resembling submucosal tumor. Twenty-eight patients, including 4 patients with Borrman 4 like formation, had tumors resembling primary gastric cancer. Three of four cases looked like Borrman 4 gastric cancer were from breast cancer. In all cases with malignant melanoma, small black dots were recognized. Conclusions: When we faced the features mentioned above at endoscopic examination, metastatic tumor to the stomach should be considered as a differential diagnosis.

Petewilliamsite, (Ni,Co)30(As2O7)15, a new mineral from Johanngeorgenstadt, Saxony, Germany: description and crystal structure

AbstractPetewilliamsite, ideally (Ni,Co)30(As2O7)15, monoclinic, space group C2, a = 33.256(5), b = 8.482(1), c = 14.191(2) Å, ß = 104.145(3)°, V = 3881.6(11) Å3, a:b:c = 3.9209:1:1.6731, Z = 2, is a new mineral found on a single nickeline-veined quartz specimen from Johanngeorgenstadt, Saxony, Germany. The mineral possesses a pronounced subcell-supercell: a (subcell) = 1/5 a (supercell); b (subcell) = b (supercell); c (subcell) = 1/3 c (supercell), and the strongest six lines of the X-ray powder-diffraction pattern are [d in Å (I) (hkl)]: 4.235(30)(020) ; 3.118(100)(513, 023); 3.005(60); 2.567(50); 1.637(50)(536 ); 1.507(30b)(553, ). It occurs predominantly as scattered patches of mm-sized aggregates which are intimately associated with varicoloured xanthiosite; additional associations include bunsenite, aerugite, rooseveltite, native bismuth, paganoite and two undefined arsenates. Subhedral equant crystals with rounded faces are intimately intergrown in 1 mm-sized aggregates and individual grains do not exceed 0.5 mm in maximum diameter. The average crystal size is variable from 20 μm to 0.3 mm. The colour varies from dark violet-red to dark brownish-red and the streak is pale reddish-brown to pale purplish-brown. Crystals are translucent, brittle, vitreous, and do not fluoresce under ultraviolet light. The mineral shows neither twinning nor cleavage, has an uneven fracture, and the calculated density (for the empirical formula) is 4.904 g/cm3. Electron-microprobe analyses gave NiO 19.45, CoO 18.39, CuO 3.40, CaO 0.17, FeO 0.04, As2O5 60.32, total 101.77 wt.%. The empirical formula, derived from crystal-structure analysis and electron-microprobe analyses, is (Ni14.662+Co13.822+Cu2.412+Ca0.17Fe0.032+)Σ31.09(As1.975+O7)15, based on O = 105 atoms per formula unit (a.p.f.u.). In reflected plane-polarized light in air, petewilliamsite is dark grey with orange to spectral (multicoloured) internal reflections and no obvious bireflectance, anisotropy or pleochroism. Measured reflectance values in air are tabulated; the index of refraction calculated at 589 nm is 1.88. The mineral name honours Professor Peter (‘Pete’) Allan Williams of the University of Western Sydney, New South Wales, Australia, for his contributions to the study of secondary minerals.The crystal structure of petewilliamsite has been solved by direct methods and refined on the basis of F2 using 9212 unique reflections measured with Mo-Kα X-radiation on a diffractometer equipped with a CCDbased detector. The final R1 was 7.68%, calculated for 1273 observed reflections. The structure contains 15 symmetrically distinct As5+ cations, each of which is tetrahedrally coordinated by four O atoms, and pairs of these AsO4 tetrahedra share a vertex which results in As2O7 pyroarsenate groups that are in layers parallel to (010). The structure also has 16 distinct transition-metal M (M: Ni,Co) sites of which there are one tetrahedral, four square bipyramidal, and 11 octahedral arrangements. Adjacent pyroarsenate groups are linked through bonds to M cations. The structure of petewilliamsite is not closely related to other naturally occurring arsenates and it is the first pyroarsenate mineral.

大型・巨大椎骨動脈りゅうに対する治療

We investigated long-term outcome of 6 patients with a large or giant aneurysm of the vertebral artery. Patients were 4 men and 2 women, aged from 26 to 74 (mean 56) years old. Only 1 patient presented with subarachnoid hemorrhage, whereas 3 patients presented with signs of brain stem compression and 2 patients with headache. Aneurysms were 18 to 40 (mean 26) mm in maximum diameter and 5 of them were thrombosed in various degrees. Three patients underwent direct surgery (neck clipping+aneurysmectomy, trapping, coating) and 3 patients were treated conservatively at initial presentation. The latter 3 patients developed deterioration of neurological symptoms and enlargement of the aneurysm within the following 4 to 6 years, and thus 2 patients underwent surgery (neck clipping+aneurysmectomy, endovascular parent artery occlusion). One month after endovascular surgery, however, 1 of the patients died of rupture of aneurysm. Long-term outcome in GOS was as follows: GR (2), SD (1), and D (3). Two patients with GR underwent direct surgery via transcodylar approach at initial presentation for aneurysms less than 30 mm in size. Although difficult in many cases, neck clipping or trapping with aneurysmectomy via the cranial base approach, before enlarging to “untreatable” size, is the best therapeutic strategy for these aneurysms. On the contrary, long-term outcome of patients with conservative treatment was poor.

Clinical experience with percutaneous ethanol injection therapy in hemodialysis patients with renal hyperparathyroidism

Background:Percutaneous ethanol injection therapy (PEIT) is a noteworthy method to treat patients with renal hyperparathyroidism (RHPT). This study was performed to enable the authors to propose appropriate indications for PEIT. Methods:The authors injected anhydrous ethanol under ultrasonographic guidance into the parathyroid glands of 74 patients with RHPT. The size, volume, and blood vessel density of all parathyroid glands detected were evaluated. Results:The patients’ mean age and hemodialysis duration were 53.8 and 14.3 years, respectively. Intact parathyroid hormone (PTH) levels decreased significantly after treatment (from 950.5 ± 448.1 to 532.0 ± 393.2 pg/mL [ng/L], P < 0.05), and the serum calcium and phosphorus levels as well as all bone metabolic parameters had improved. The percentage reduction was greater in cases with 1 gland over 10 mm in maximal diameter, and, as the number of glands over 10 mm rose, the percentage reduction declined. Group A was defined as patients with a small number of glands (1 or 2) with high-grade blood vessel density, and group B as patients with a larger number of such glands. The percentage reduction in intact PTH levels was significantly greater in group A than in group B (56.5 ± 27.5% v 28.1 ± 22.0%; P < 0.01). Conclusion:the authors’ analysis showed that the effectiveness of PEIT was influenced by both the number of glands detected that were more than 10 mm in maximal diameter and by the grade of blood vessel density. They identified appropriate indications for PEIT based on the predictive factors that influenced the efficacy of PEIT.

Management of vestibular schwannoma by fractionated stereotactic radiotherapy and associated cerebrospinal fluid malabsorption

The goal of this study was to investigate outcomes in patients with vestibular schwannoma (VS) who were treated with fractionated stereotactic radiotherapy (SRT). One hundred one patients with VS were treated with fractionated SRT at a radiation level of 40 to 50 Gy administered in 20 to 25 fractions over a 5- to 6-week period. The median tumor size in these patients was 19 mm (range 3-40 mm), and 27 tumors were larger than 25 mm. Patients were consistently followed up using magnetic resonance imaging every 6 months for 5 years in principle. The median follow-up period was 45 months. The actuarial 5-year rate of tumor control (no growth > 2 mm and no requirement for salvage surgery) was 91.4% (95% confidence interval 85.2-97.6%). Three patients with progressive tumors underwent salvage tumor resection. The actuarial 5-year rate of useful hearing preservation (Gardner-Robertson Class I or II) was 71%. The observed complications of fractionated SRT included transient facial nerve palsy (4% of patients), trigeminal neuropathy (14% of patients), and balance disturbance (17% of patients). No new permanent facial weakness occurred after fractionated SRT. Eleven patients (11%) who had progressive communicating hydrocephalus (cerebrospinal fluid malabsorption) and no evidence of tumor growth after fractionated SRT required a shunt. The symptoms of this type of hydrocephalus were similar to those of normal-pressure hydrocephalus and occurred 4 to 20 months (median 12 months) after fractionated SRT. The mean size (+/- standard deviation) of tumors causing symptomatic hydrocephalus (25.5 +/- 7.8 mm) was significantly larger than that of other tumors (18.2 +/- 8.7 mm) (p = 0.011). Only four of the 72 patients with tumors smaller than 25 mm in maximum diameter received a shunt. Fractionated SRT resulted in an excellent tumor control rate, even for relatively large tumors, and produced a high rate of hearing preservation that was comparable to the best results of single-fraction radiosurgery. The progression of communicating hydrocephalus should be monitored closely, particularly in patients harboring a large VS.

La coloscopie virtuelle joue-t-elle un rôle dans le dépistage du cancer colorectal?

Virtual colonoscopy (VC) represents a new promising methodology of noninvasive examination of the colon and rectum in patients screened for colorectal cancer or adenomas. The major advantages of this examination as compared to colonoscopy are 1) the limited risk, as no colonie perforation has been reported at this time and 2) the absence of need for sedation, although patient’s comfort does not appear to be optimal during prone and supine acquisitions of VC. The clinical usefulness of VC has to be estimated by comparison with available screening tests in different situations: Hemoccult and colonoscopy for general population screening and colonoscopy in case of patients at higher risk of colorectal cancer. The case of high risk patients appears simple: the perpolyp sensitivity of VC ranges between 40 and 100% for polyps more than 10 mm in maximal diameter, and drops for smaller lesions including flat adenomas that represent 30 % of all adenomas, and are a characteristic of these highrisk patients in case of HNPCC syndrome. Thus, VC does not compare favorably with colonoscopy in this group of atrisk patients. Regarding patients from the general population with a 4% cumulated risk of colorectal cancer, VC has a clearly higher sensitivity than Hemoccult for the diagnosis of cancer or adenomas. However, in a population context, increased specificity is a major aim in order to avoid unnecessary colonoscopies. The specificity of VC colonoscopy appears lower than that of Hemoccult, and most of all no prospective populationbased study has been performed: specificity would probably drop in such studies, as compared to selected population at higher risk of colorectal cancer and adenomas, for multiple reasons including the fear of missing adenoma or cancer. Moreover, despite this bias that overestimates the specificity of VC, costefficacy studies have shown that VC is at this time the more costly screening modality as compared to Hemoccult and colonoscopy. For all these reasons, indications of VC remain limited to incomplete colonoscopy (because of colonie loops or obstructive cancer) and examination of old and/or diseased patients not suitable for usual colonoscopy. These are the actual recommendation of the French Health Accreditation Agency (ANAES) as well as that of the American Society for Gastrointestinal Endoscopy (ASGE).

MDCT scan visualizes the adamkiewicz artery

Ischemic spinal cord injury is a serious complication after surgical repair of descending thoracic or thoracoabdominal aortic aneurysm. The Adamkiewicz artery (arteria radicularis magna [ARM]) is well known as a main feeder of the spinal cord. It originates from a segment of the intercostal or lumbar artery. The anatomical information of the ARM is important in conducting surgical strategy and may reduce the risk of postoperative neurologic deficit. To detect the ARM, selective angiography and magnetic resonance angiography have been used and reported to identify the ARM in 70% to 80% of patients. Alternatively, we have adopted a fourchannel multi-detector row computed tomographic (MDCT) scan that could successfully visualize the ARM. A 70-year-old man with a dissecting thoracoabdominal aortic aneurysm (DeBakey type IIIb; maximal diameter, 60 mm) underwent MDCT scan, as seen in this helical computed tomographic image (Fig 1A). The axial computed tomographic image shows the aneurysm that it is 60 mm in maximal diameter (Fig 1B). The study revealed the ARM originating from the left L1 lumbar artery and connecting to the anterior spinal artery with the classic “hairpin” bend, as seen in this preoperative MDCT scan with coronal reformation (Fig 2 [ASA aspirin]). His surgical repair consisted of aneurysmectomy and graft replacement with the reconstruction of the left T8 and T10 intercostal arteries, the left L1 lumbar artery, the celiac artery, the superior mesenteric artery, and the bilateral renal arteries. To minimize the duration of spinal cord ischemia, the left L1 lumbar artery was reconstructed first. The postoperative MDCT scan after the operation showed that the ARM was successfully reconstructed (Fig 3) and no neurologic complication was noticed. The MDCT scan was acquired under a protocol approved by our institutional review board. Computed tomographic images were obtained while injecting 100 mL of 350 mg/dL iodinated contrast medium at a flow rate of 5 mL per second through the right antecubital vein. A 0.5 second tube-detectors rotation time and helical pitch 5 were used. The patient was requested to breathe quietly during the scan. All computed tomographic data were processed in our three-dimensional imaging workstation to get sagittal and coronal reformations of 1-mm thickness. The MDCT scan is noninvasive to visualize the ARM and helpful in surgical repair of the descending thoracic or thoracoabdominal aortic aneurysm. Moreover, this study is economically acceptable and is not time consuming. Address reprint requests to Dr Shiiya, Department of Cardiovascular Surgery, Hokkaido University School of Medicine, Kita 14, Nishi 5, Kita-ku, Sapporo, Hokkaido 060-8648, Japan; e-mail: shiyanor@ med.hokudai.ac.jp. Fig 1.

Lung cysts in subacute hypersensitivity pneumonitis.

To determine the frequency of cystic lesions on high-resolution computed tomography (CT) in patients with subacute hypersensitivity pneumonitis. High-resolution CT scans in 182 patients with proven subacute hypersensitivity pneumonitis were retrospectively evaluated for the presence of lung cysts. Patients with CT evidence of emphysema or interstitial fibrosis and patients with connective tissue disease were excluded from the study. Two thoracic radiologists reviewed the thoracic CT scans for the presence and location of lung cysts. Thin-walled lung cysts were identified in 24 (13%) of 182 patients and ranged in size from 3 to 25 mm in maximal diameter. The patients included 16 men and 8 women (age range, 30-79 years; mean age, 48 years). The cysts ranged from 1 to 15 in number (mean, 4 cysts) and had a random distribution. Sixteen of the 24 patients also had areas of decreased attenuation and vascularity consistent with air trapping. Thin-walled cysts can be seen in a small percentage of patients with subacute hypersensitivity pneumonitis. The cysts resemble those seen in lymphocytic interstitial pneumonia, and their pathogenesis is uncertain.

Endovascular treatment of anterior communicating artery aneurysms: results of clinical and radiological outcome in Newcastle

The results of endovascular management of anterior communicating artery aneurysms (ACoAA) using Guglielmi Detachable Coils (GDC) are presented. We detail the clinical and radiological features, and postoperative clinical and radiological outcome in a consecutive series of patients. We have prospectively collected comprehensive data on our patients with SAH since 1989. This study reports on patients admitted between January 1990 and December 1998, and focuses on 30 patients who had their ACoAA endovascularly treated. An independent observer (TE) carried out long-term follow-up in January 2002. Statistical analysis was performed to study the relationship between clinical factors, the radiological morphology of aneurysms and the long-term outcome. The age ranged from 25 to 74 years (median: 54) and endovascularly treated ACoAA were more common in women, 19 (63%) compared with men, 11 (37%). Seventy-seven per cent were in good grade (WFNS 1&2) before treatment. Three patients rebled before treatment. The aneurysms were less than 10 mm in maximal diameter in 27/30 patients. The follow-up period was from 1 to 53 months (mean 32.5, median 36.6 months). Excellent outcome was recorded for 11 patients (36.7%), good in seven patients (23.3%), fair in three patients (10%) and poor in four cases (13.3%). Five patients had died (mortality 16.7%). Favourable outcome was achieved in younger patients, women, and in those who presented in grades 1 and 2. The long-term radiological follow-up revealed residual necks in 13 patients. Only one has required retreatment and no rebleed has occurred in 3 - 6 years. This study reports a contemporary experience with the endovascular management of ACoAA. Long-term stability of the coil and good outcome is demonstrated. Endovascular treatment using GDC is an efficient technique for treating acutely ruptured ACoAA with little additional morbidity. The clinical and radiological results are comparable with those in the literature.