Metastasis in para-aortic lymph nodes in patients with advanced gastric cancer, treated with extended lymphadenectomy

BACKGROUND/AIMS

Lymph node dissection is an essential component of curative resection for advanced gastric cancer. To improve the survival of N2 patients, Asian surgeons have been performing D2+para-aortic lymph node dissection. The current study presents the results of lymph node status from multicenter trial of D2 and D2 + para-aortic nodal (No.16) dissection (D4 dissection).

METHODOLOGY

Patients enrolled in the study had potentially curable gastric adenocarcinoma in an advanced stage, T2, T3 or T4/N1 or N2. Patients were randomized to undergo either D2 or D4 gastrectomy.

RESULTS

Two hundred and seventy patients were registered and 136 and 134 patients were allocated into the D2 or D4 group, respectively. The average nodal yield of No.16 in D4 group was 18.4 +/- 14.1, ranging from 2 to 84. No.16 metastasis was detected in 12 (9.0%) of 134 D4 patients. One, 9 and 2 patients had simultaneous involvement in N1, N2, and N3 (No.8p, 12, 13 or 14). Namely, in 39 patients who were diagnosed as N2 from the lymph node status in N1 and N2 levels, nine (23.0%) patients had No.16 metastasis. The stage migration by D4 was found in 10 (7.5%). Logistic regression analysis revealed that the stations of No.7 and No.8 were the significant predictors of No.16 involvement.

CONCLUSIONS

The present study may strongly suggest that prophylactic D4 dissection may be indicated for patients with N2 involvement, and that No.7 and No.8 are the junctional nodes for D4 dissection.

Suitable whole blood levels 2 hours after neoral in liver transplant patients: experiences at a single center

Whole blood levels 2 hours after Neoral (C2) administration were observed to correlate better with area under the curve (AUC(0-4)) than trough levels (C0), suggesting that C2 may be the best single time point predictor of Neoral absorption. Owing to concerns about drug toxicity due to excessive immunosuppression, C2 adjustments to target blood levels may represent an advance. The present study measured C2 and levels to determine which correlated more closely with AUC(0-4).

METHODS

Between August 2003 and July 2004, 40 adult liver transplantations were performed in our center. All patients received Neoral twice daily. They were maintained at a C0 level of about 200 ng/mL. C0 levels were measured daily. C2 levels were estimated on postoperative days 3, 5, 7, 14, and 28. AUC(0-4) performed on postoperative days 3, 7, and 28 was calculated using the trapezoidal rule.

RESULTS

The mean AUC(0-4), C0, C1, C2, C3, and C4 were 1100.3 +/- 484.8 ng/mL, 197.1 +/- 84.7 ng/mL, 240.7 +/- 166.2 ng/mL, 307.8 +/- 162.6 ng/mL, 302.8 +/- 138.9 ng/mL, and 300.3 +/- 142.8 ng/mL, respectively. C2 correlated with AUC(0-4) (R2 = 0.868: P < .05) better than C0 (R2 = 0.245: P < .05), C1 (R2 = 0.604: P < .05), or C4 (R2 = 0.583: P < .05).

CONCLUSIONS

Neoral dose monitoring according to a mean C2 range of 307.8 +/- 162.6 ng/mL correlated better with AUC(0-4). Further studies are required to determine suitable C2 levels in liver transplant patients.

Adjuvant chemotherapy with 5-fluorouracil, doxorubicin and mitomycin-C (FAM) for 6 months after curative resection of gastric carcinoma

AIM

This study aimed to evaluate the efficacy and safety of 5-fluorouracil (5-FU), doxorubicin and mitomycin-C (FAM) adjuvant chemotherapy in patients who had undergone curative resection of gastric carcinoma.

METHODS

From Nov 1999 to Jan 2002, 291 consecutive patients with stage IB-IIIB gastric adenocarcinoma were given FAM adjuvant chemotherapy. Chemotherapy comprised intravenous 5-FU 600 mg/m(2) (days 1, 8, 29 and 36), doxorubicin 30 mg/m(2) (days 1 and 29) and mitomycin-C 10 mg/m(2) (day 1), every 8 weeks for 6 months.

RESULTS

The median follow-up time was 60.6 months, 92 patients died, and 93 patients had recurrent disease. The 5-year overall survival (OS) rates were 85.9% for stage IB, 72.1% for stage II, 58.0% for stage IIIA, and 48.2% for stage IIIB (p=0.002). The 5-year relapse-free survival (RFS) rates were 85.2% for stage IB, 71.2% for stage II, 53.3% for stage IIIA, and 39.2% for stage IIIB (p<0.001). A total of 769 cycles of chemotherapy were delivered, and 15 patients experienced grade 3 or higher leukopenia. The most common grade 3 or higher non-hematologic toxicity was nausea/vomiting (11 patients), followed by stomatitis (3 patients).

CONCLUSIONS

Adjuvant chemotherapy with FAM for 6 months for gastric carcinoma indicated comparable RFS and OS with an acceptable toxicity profile.

Continuous removal of hydrogen peroxide with immobilised catalase for wastewater reuse

Hydrogen peroxide was continuously removed for wastewater reuse using an immobilised biocatalyst. A commercial catalase, which is an enzyme to decompose hydrogen peroxide to water and oxygen, was entrapped in chitosan beads. Hydrogen peroxide in aqueous solutions of varying pH, temperature and concentration was continuously removed through a reactor containing the catalase-entrapped chitosan beads at high efficiency for 24 h. Additional silicate coating of the chitosan beads resulted in significant improvements in the catalase performance under harsh conditions, which are often found in peroxide-based industrial processes. We expect that immobilisation of catalases can enhance their applicability for continuous degradation of hydrogen peroxide for wastewater reuse.

Molecular analysis of Staphylococcus aureus isolates associated with staphylococcal food poisoning in South Korea

AIMS

To investigate the molecular epidemiological study of Staphylococcus aureus from staphylococcal food poisoning (SFP) incidents in South Korea.

METHODS AND RESULTS

Three hundred and thirty-two strains isolated from ten provinces between June 1999 and January 2002 were characterized by staphylococcal enterotoxin genes, toxic shock syndrome toxin 1 (tst) gene, and exfoliative toxin genes. Toxin genotypes were sea-seh (n=197), sea (n=51), sea-seg-sei (n=14), seg-sei (n=10), seb (n=10), seb-sed-seg-sei-sej (n=3), sea-seg-seh-sei (n=1), sea-seb (n=1), sea-sec (n=1), seg-sei plus eta (n=4), and sea-seg-sei plus tst (n=40). Most of the strains could be classified into three clusters of pulsed-field gel electrophoresis (PFGE) types A and B with coagulase type VII and type E with coagulase type IV. Of the ten sequence types (ST), ST1, ST59, and ST30 were frequently showed by multilocus sequence typing.

CONCLUSIONS

The strain belonging to PFGE pattern A with sea-seh gene, coagulase VII, and ST1 was the most epidemic clone of SFP incidents in Korea.

Neoadjuvant imatinib in locally advanced gastrointestinal stromal tumors of the stomach: report of three cases

Neoadjuvant imatinib therapy used to treat locally advanced or metastatic gastrointestinal stromal tumors (GI ST) remains under active investigation. We studied three cases of locally advanced gastric GISTs treated with imatinib on a neoadjuvant basis, followed by a complete surgical resection. Three patients were diagnosed with locally advanced unresectable GIST of the stomach and were started on imatinib 400 mg/day. After the imatinib treatment, partial responses were achieved in all patients and the tumors were considered resectable. Surgical resection was done after 7, 11, and 8 months of imatinib therapy, respectively. In one case, a metastatic liver lesion was detected during the imatinib treatment using computed tomography scans, so the imatinib therapy was maintained for 11 months postoperatively. In the other two patients without distant metastasis, imatinib treatment was not restarted after surgery. Mutational analysis revealed a mutation in exon 11 of the c-kit gene in two patients, and wild-type c-kit and PDGFRA in one patient. During pathology review of all three cases, we noted several features common to imatinib treatment. There was no evidence of tumor recurrence in all three patients at respective follow-up visits of 22, 15, and 7 months. These results suggest that the neoadjuvant imatinib therapy is a potentially curative approach for selected patients with locally advanced GIST.

Association of Br polymorphism of platelet GP Ia gene and immune thrombocytopenic purpura

Studies on the molecular structure underlying Br(a)/Br(b) (HPA-5) platelet alloantigen show that a single base polymorphism at position 1648 on platelet mRNA coding for GP Ia results in a amino acid substitution at position 505 on the mature GP Ia which is associated with the two serologically defined Br types. While this polymorphism has no known effects on platelet function, the possible influence of this polymorphism in immune thrombocytopenia ITP is again unexplored. Therefore, the genotype frequency of Br polymorphism in ITP was compared with that of healthy general Korean population. Interestingly, there was a statistical difference (P=0.03) in genotype frequency of Br polymorphism. The association of Br(a)/Br(b) (HPA-5)genotype and occurrence of ITP may suggest the possible influence of genetic polymorphism on the pathogenesis of ITP.

Operative morbidity and mortality after D2 and D4 extended dissection for advanced gastric cancer: a prospective randomized trial conducted by Asian surgeons

BACKGROUND/AIMS

A randomized study was performed to evaluate morbidity and mortality after D2 (level 1 and 2 lymphadenectomy) and D4 (D2 plus lymphadenectomy of para-aortic lymph nodes) dissection for advanced gastric cancer.

METHODOLOGY

Two hundred and fifty-six patients with advanced gastric adenocarcinoma were enrolled (128 to each group). Patients were randomly allocated into D2 (N = 128) or D4 (N = 128) group. The first and second tiers of lymph nodes are removed in D2 dissection. In D4 gastrectomy, the paraaortic lymph nodes were additionally removed.

RESULTS

There was no indication of significant distribution bias with regard to age, sex, T-grade, and N-grade between the two groups. Operation time of D4 gastrectomy (369 +/- 120 min) was significantly longer than that of D2 gastrectomy (273 +/- 1103 min), and blood loss of the D4 group (872 +/- 683 mL) was significantly greater than that of the D2 group 571 +/- 527 mL (P < 0.001). Five (4%) and two (2%) medical complications developed in the D2 and D4 groups, respectively. Surgical complications developed in 28 (22%) and 48 patients (38%) after D2 and D4 gastrectomy. The most common complications were anastomotic leakage, pancreatic fistula, and abdominal abscess. Pancreatic fistula developed in 6 (19%) of 32 patients after D4 plus pancreatosplenectomy, but the incidence of pancreatic fistula after D2 gastrectomy plus pancreatosplenectomy was low (6%, 1/16). Two patients died within 30 days of operation (0.8%, 2/256), and each patient belonged to the D2 and D4 group.

CONCLUSIONS

Although there is a significantly higher surgical complication rate in D4 dissection, D4 dissection can be done safely as D2 dissection when performed by well-trained surgeons.

The point prevalence and associated factors of nasal methicillin-resistant Staphylococcus aureus colonisation in eight geriatric hospitals in Korea

The prevalence and associated factors of nasal methicillin-resistant Staphylococcus aureus (MRSA) colonisation were investigated among patients in geriatric hospitals in Korea. S. aureus was isolated from 317 (50.2%) of 632 patients. The nasal MRSA colonisation prevalence was 36.1%. In bivariate analysis, stay in an intensive care unit, decreased functional status, recent use of antibiotics, use of urinary catheters and the existence of skin breaks were associated with nasal MRSA colonisation (p < 0.05). Of these factors, only decreased functional status and recent use of systemic antibiotics were associated independently with nasal MRSA colonisation following logistic regression analysis.

Efficacy and safety study of docetaxel as salvage chemotherapy in metastatic gastric cancer failing fluoropyrimidine and platinum combination chemotherapy

PURPOSE

Fluoropyrimidine (F) and platinum (P) combination chemotherapy has been widely used for the first line treatment of advanced gastric cancer (AGC). Docetaxel (D) has shown promising activity in this disease. The present study retrospectively investigated the efficacy of D monotherapy as salvage chemotherapy for AGC that is failing F and P combination chemotherapy.

MATERIALS AND METHODS

A total of 34 patients, fitting the eligibility criteria, were included in this study. D was administered at a dose of 75 mg/m(2) IV every 3 weeks, with dexamethasone prophylaxis. Twenty-nine patients had measurable lesions. The median treatment-free interval was 38.5 days, and 91.2% of patients had progressed within 4 months of withdrawal of the first line chemotherapy.

RESULTS

A total of 133 cycles of D were administered, with a median of 3.5 (1 approximately 8) cycles. From an intention-to-treat analysis, 6 patients achieved partial responses (PR), with a response rate of 20.7% (95% CI, 6.0~35.4). The duration of objective PRs in these six were 2.3+, 2.5+, 2.9, 3.0+, 6.2 and 6.8 months, respectively. Six patients showed a stable disease, but 15 showed progression. The median time to progression was 4.2 months (95% CI, 2.8 approximately 5.5), with a median overall survival since the start of D monotherapy of 8.4 months (95% CI, 5.5 approximately 11.3). Grade 3/4 neutropenia and febrile neutropenia occurred in 12.9% of patients and 3.1% of cycles. The incidence of grade 3 or worse non-hematological toxicities were as follows; peripheral sensory neuropathy 9.7%, asthenia 3.2% and allergic reaction 2.7%.

CONCLUSION

Docetaxel, 75 mg/m(2), is active in AGC as second-line chemotherapy after failure of prior exposure to the F and P combination chemotherapy, with a favorable toxicity profile.

Aberrant CpG island methylation in early-onset sporadic gastric carcinoma

PURPOSE

Gastric carcinoma more commonly affects older patients, and it is thought that cases of early-onset gastric carcinoma may develop with a different molecular profile different from that of carcinoma occurring at a later age. We assayed the methylation status and genetic changes in genes associated with the APC-beta-catenin axis and the mismatch repair system in relatively early-onset gastric carcinoma samples to determine their association with gastric carcinogenesis.

METHODS

Tumor and normal tissue DNA samples were obtained from 40 patients with early-onset (< 50 y) gastric carcinomas and assayed for APC and CTNNB1 mutations, microsatellite instability, and methylation of the promoters of the hMLH1, TIMP3, THBS1, DAP- K, GSTP1 , APC, and MINT2.

RESULTS

Promoter methylation at these seven loci ranged from 12.5 to 62%, with 38/40 tumors (95%) showing promoter methylation at more than one locus. The CpG island methylation phenotype (CIMP) was classified as high in 16 tumors (40%), low in 22 tumors (55%), and negative in 2 tumors (5%). Two concurrent missense mutations (E1685G, R1763L) in the APC mutation cluster region were detected in two tumors, nine tumors showed loss of APC heterozygosity (LOH), and two showed both LOH and promoter methylation.

CONCLUSIONS

Our results indicate that, unlike in colorectal carcinoma, APC and CTNNB1 mutations do not appear to be highly implicated in early-onset gastric carcinogenesis. In contrast, our data show that promoter methylation is a prevalent phenomenon in early-onset gastric carcinoma and may be related to gastric carcinogenesis.

Magnetic resonance imaging and diffusion-weighted imaging changes after hypoglycemic coma

The authors report a case of severe hypoglycemic encephalopathy in an elderly patient. The magnetic resonance images showed bilateral cortical signal changes and basal ganglia lesions, which spared the thalami. The lesions were bright on fluid-attenuated inversion recovery and diffusion-weighted images and dark on the apparent diffusion coefficient map, being more conspicuous on the diffusion-weighted images than on the fluid-attenuated inversion recovery images. A literature review of the imaging features and pathophysiological mechanism in comparison with those of hypoxic ischemic injury is discussed.

Prospective study of the effectiveness of percutaneous transhepatic photodynamic therapy for advanced bile duct cancer and the role of intraductal ultrasonography in response assessment

BACKGROUND AND STUDY AIMS

We evaluated the therapeutic effects of percutaneous transhepatic photodynamic therapy (PDT) in patients with advanced bile duct cancer. The utility of intraductal ultrasonography (IDUS) for the assessment of responses and for regular follow up after PDT was also examined.

METHODS

Percutaneous transhepatic biliary drainage (PTBD) was initiated before PDT. Following dilation and maturation of the PTBD tract, percutaneous PDT was performed. Intraluminal photoactivation was carried out using percutaneous cholangioscopy 2 days after intravenous application of a hematoporphyrin derivative. All patients were additionally provided with percutaneous bile duct drainage catheters after PDT. IDUS was conducted monthly to measure the thickness of the tumor mass before and after PDT.

RESULTS

24 patients with advanced cholangiocarcinomas (Bismuth IIIa, n = 4; IIIb, n = 10; IV, n = 10) were treated with PDT. At 3 months after PDT, the mean thickness of the tumor mass had decreased from 8.7 +/- 3.7 mm to 5.8 +/- 2.0 mm (P < 0.01). At 4 months after PDT, the thickness of the mass had increased to 7.0 +/- 3.7 mm. Quality of life indices improved dramatically and remained stable 1 month after PDT; the Karnofsky index increased from 39.1 +/- 11.36 to 58.2 +/- 22.72 points (P = 0.003). The 30-day mortality rate was 0 %, and the median survival time was 558 +/- 178.8 days (current range 62 - 810 days).

CONCLUSIONS

PDT using percutaneous cholangioscopy is safe and effective for advanced hilar cholangiocarcinoma, and seems to prolong survival. IDUS is useful for evaluating changes in the thickness of the tumor mass after PDT.

Docetaxel (Taxotere), cisplatin, UFT, and leucovorin combination chemotherapy in advanced gastric cancer

We conducted this study to ascertain the efficacy and toxicity of docetaxel and cisplatin combined with oral UFT and leucovorin as a first-line treatment for patients with advanced gastric cancer. In all, 52 patients received courses of docetaxel 60 mg m(-2) intravenously (i.v.) for 1 h and then cisplatin 75 mg m(-2) i.v. for 2 h on day 1. Oral UFT at 400-600 mg day(-1), as determined by body surface area, and leucovorin at 75 mg day(-1) were administered for 21 consecutive days from day 1, and this was followed by a 7-day drug-free interval. A total of 225 courses were administered, and the median number of courses per patient was four. Four complete responses (7.7%) and 22 partial responses (42.3%) were achieved, giving an overall response rate of 50% (95% Confidence Interval: 36.4-63.6%). The major toxicity was neutropenia, which reached grade 3/4 in 36 patients (69.3%). Grade 3/4 nausea and vomiting was observed in 12 patients (23.1%). Median time to progression was 22 weeks (4 to 156+ weeks), median survival duration was 48 weeks (4 to 156+ weeks), and median response duration was 24 weeks (6-152 weeks). We conclude that docetaxel, cisplatin, oral UFT, and leucovorin combination chemotherapy is effective and tolerable for the treatment of advanced gastric cancer.

Clinicopathological analysis of Borrmann type IV gastric cancer

PURPOSE

Borrmann type IV gastric cancer is often diagnosed only at an advanced stage, resulting in a prognosis poor. We performed a retrospective study of the clinical characteristics of Borrmann type IV gastric cancer and the prognostic factors affecting the survival rate in such patients.

MATERIALS AND METHODS

Of 4,063 patients with all gastric cancers, 370 (9%) with Borrmann type IV gastric cancer were analyzed.

RESULTS

The clinical characteristics of these patients included a higher incidence rate in young females, and higher rates of serosa exposure, metastasis to lymph nodes and early peritoneal dissemination. Of patients presenting with peritoneal seeding, those resected had a higher survival rate than those that were not. A univariate analysis showed that the prognostic factors affecting the survival rate following a curative resection were the location, occupied area and depth of the primary tumor, as well as the presence of lymph node metastasis and the tumor stage. A multivariate analysis indicated that the tumor location and stage were significant independent prognostic factors after a curative resection for Borrmann type IV gastric cancer.

CONCLUSION

In conclusion, the early diagnosis and treatment of patients with Borrmann type IV gastric cancer are essential for the better survival of these patients. Even in patients with advanced tumors, a noncurative palliative resection may improve the prognosis.

Management of malignant stricture of the esophagogastric junction with a newly designed self-expanding metal stent with an antireflux mechanism

BACKGROUND AND STUDY AIMS

When stents are placed across the esophagogastric junction for palliative treatment of malignant strictures, they may lead to esophagogastric reflux. The aim of this study was to compare the effectiveness of a newly designed antireflux stent with that of a standard open stent and a currently available antireflux stent (Dostent) in preventing gastroesophageal reflux symptoms in patients with inoperable cancer at the esophagogastric junction.

PATIENTS AND METHODS

Thirty-six consecutive patients with cancer at the esophagogastric junction were randomly assigned to undergo placement of a newly designed antireflux stent (n = 12), a Dostent (n = 12), or a standard open stent (n = 12). Technical and clinical success, dysphagia score, reflux symptoms, complications and ambulatory 24-h esophageal pH monitoring were assessed.

RESULTS

The technical success rates were 100 %. After 1 week, dysphagia had improved in all patient groups ( P < 0.05), but the degree of improvement did not differ between the three groups. The DeMeester score was significantly lower in the group with the newly designed antireflux stent than in the other groups. The fraction of the total recording time during which esophageal pH was below 4 was 3.14 +/- 5.78 % using the newly designed antireflux stent, in comparison with 29.25 +/- 15.41 % in the Dostent group and 15.01 +/- 11.72 % in the standard open stent group ( P < 0.001). Fewer reflux episodes occurred with the newly designed antireflux stent than with the Dostent or standard open stent. There were no complications with any of the three stents.

CONCLUSIONS

The newly designed antireflux stent is effective in relieving dysphagia caused by malignant cancer at the esophagogastric junction. The newly designed antireflux stent is significantly more effective in preventing gastroesophageal reflux than currently available antireflux stents.

Phase II study of capecitabine and cisplatin as first-line combination therapy in patients with gastric cancer recurrent after fluoropyrimidine-based adjuvant chemotherapy

To evaluate the efficacy and safety of capecitabine and cisplatin in patients with recurrent gastric cancer after fluoropyrimidine-based adjuvant therapy. Patients with histologically confirmed and measurable advanced gastric cancer that had relapsed after fluoropyrimidine-based adjuvant chemotherapy received oral capecitabine (1250 mg m(-2) twice daily, days 1-14) and intravenous cisplatin (60 mg m(-2) over 1 h, day 1) every 3 weeks. In total, 32 patients were enrolled, of whom 30 were evaluable for efficacy and 32 for safety. A median of 5 cycles (range 1-10) was administered. One patient achieved a complete response and eight had partial responses, giving an overall response rate of 28% (95% CI, 13-44%). The median time to progression and median overall survival were 5.8 months (95% CI, 4.1-7.5 months) and 11.2 months (95% CI, 5.5-16.9 months), respectively. Grade 3 neutropenia and thrombocytopenia were observed in 38 and 6% of patients, respectively. Grade 2/3 nonhaematological toxicities included diarrhoea (19%), stomatitis (19%) and hand-foot syndrome (31%). No grade 4 toxicity, neutropenic fever or treatment-related deaths occurred. Capecitabine in combination with cisplatin was effective and well tolerated as first-line treatment in patients with recurrent gastric cancer after fluoropyrimidine-based adjuvant chemotherapy.

Multiple de novo vascular malformations in relation to diffuse venous occlusive disease: a case report

Brain vascular malformations are dynamic disorders. Although mostly considered to be of congenital origin, the improvement of clinical imaging and vasculogenesis knowledge has shown that they might also result from a biological dysfunction of the remodeling process after birth. Venous occlusive disease and ishemia may represent powerful revealing triggers and support the capillary venous origin of some vascular malformations. We report a unique case of the development of multiple de novo vascular malformations (transverse sinus dural fistula and posterior fossa cavernomas) following acoustic neuroma surgery.

3-D magnetic measurement of neuromagnetic response of somatosensory area to different repetition frequencies

3-D magnetic measurements of the bilateral somatosensory evoked fields (SEFs) by electric stimulus to the right thumb for four normal subjects were carried out, using a three-dimensional (3-D) second-order gradiometer connected to 39-channel SQUIDs, which can detect magnetic field components perpendicular to the scalp (Br) and tangential to the scalp (Btheta, Bphi) simultaneously. To discuss the relationship between the phase lag and stimulus repetition frequency (SRF), the delay times of a component synchronous with the SRFs (1.99 to 27.02 Hz) were calculated by the convolution of the reference signal and the SEF wave (BPF: 15-40 Hz). The phase lag characteristic to the SRF in the contralateral hemisphere to the stimulus was linear in the ranges below 8 Hz and above 8 Hz in all magnetic components. The phase lag characteristic of the ipsilateral hemisphere to the stimulus was linear in only below-8 Hz in all components. It was tested for significance of the linear regression slope (beta not = 0, P<0.05).

3-D magnetic measurement of exercise-induced MCG

We carried out a three-dimensional (3-D) vector measurement of exercise-induced magnetocardiograms (MCGs) for normal subjects with a wooden and brass-based bicycle ergometer. MCGs were measured by a 3-D second-order gradiometer connected to 39-channel SQUIDs, which can detect magnetic field components perpendicular to the chest wall (Bz) and tangential to the chest wall (Bx, By) simultaneously. Time-frequency analysis was applied to rest times and exercise-induced MCG data. It was shown that the power spectrum of the ST segment was different between the rest times and exercise-induced MCG. Principal component analysis (PCA) was also applied to the result of time-frequency analysis and the time course of frequency for the ST segment was evaluated quantitatively. It found that dominant frequency of the ST segment in the rest time was ranged 5.5 to 6.5 Hz in all components. And it was clearly shown that the peak frequency of the exercise-induced MCG was shifted to 10.5 Hz compared to that of rest MCG.

Prognostic significance of c-kit mutation in localized gastrointestinal stromal tumors

PURPOSE

Constitutive mutational activation of c-kit has been found to be associated with the pathogenesis of gastrointestinal stromal tumors (GISTs). The prognostic significance of c-kit mutations, however, is still controversial.

EXPERIMENTAL DESIGN

We examined 86 patients curatively resected for localized GIST. Genomic DNA was extracted from paraffin-embedded tumor tissues. Exons 9, 11, 13, and 17 of the c-kit gene were amplified by PCR and sequenced.

RESULTS

Mutations in exon 11 were detected in 61 tumors, and mutations in exon 9 were observed in three tumors, whereas no mutations were detected in exons 13 or 17. The overall c-kit mutation frequency was 74%. Amino acid alterations in the 61 tumors with exon 11 mutations were deletion in 33 tumors, substitution in 20, both deletion and substitution in 4, insertion in 1, and duplication in 3. Histologically, tumors with c-kit mutations showed higher mitotic counts and higher cellularity. The 5-year relapse-free survival (RFS) in patients having GISTs with c-kit mutations was 21%, compared with 60% in those without c-kit mutations. Significantly higher RFS rates were observed in patients with tumors having mitotic counts < 5 mitoses/50 high power field, spindle-cell histology, tumor size < 5 cm, or gastric GISTs. Multivariate analyses indicated association of poorer RFS with a higher mitotic count > or = 5 of 50 high power fields; odds ratio (OR) = 3.0], presence of c-kit mutations (OR = 5.6), and a larger tumor size (> or = 5 cm; OR = 4.2).

CONCLUSIONS

The presence of c-kit mutation, along with high mitotic count and larger tumor size, was an independent factor for poor prognosis in patients with localized GISTs.

Atypical manifestations of reversible posterior leukoencephalopathy syndrome: findings on diffusion imaging and ADC mapping

Typically, reversible posterior leukoencephalopathy syndrome (RPLS) involves the parieto-occipital lobes. When regions of the brain other than the parieto-occipital lobes are predominantly involved, the syndrome can be called atypical RPLS. The purpose of this study is to find radiological and pathophysiological features of atypical RPLS by using diffusion-weighted imaging (D-WI). We retrospectively reviewed seven patients (two with eclampsia, one with cyclosporine neurotoxicity, and four with hypertensive encephalopathy) with atypical MR manifestations of RPLS. Changes in signal intensity on T2-weighted imaging (T2-WI) and D-WI, and ADC ratio, were analyzed. In patients with atypical manifestation of RPLS, high signal intensities on T2-WI were noted in the frontal lobe, basal ganglia, thalamus, brainstem, and subcortical white matter in regions other than the parieto-occipital lobes. These areas of increased signal intensities on T2-WI showed increased ADC values, representing vasogenic edema in all seven patients. This result should be very useful in differentiating atypical RPLS from other metabolic brain disorders that affect the same sites with cytotoxic edema.