Extracellular volume fraction using contrast-enhanced CT is useful in differentiating intrahepatic cholangiocellular carcinoma from hepatocellular carcinoma

Objectives

To evaluate whether tumor extracellular volume fraction (fECV) on contrast-enhanced computed tomography (CT) aids in the differentiation between intrahepatic cholangiocarcinoma (ICC) and hepatocellular carcinoma (HCC).

Methods

In this retrospective study, 113 patients with pathologically confirmed ICC (n = 39) or HCC (n = 74) who had undergone preoperative contrast-enhanced CT were enrolled. Enhancement values of the tumor (Etumor) and aorta (Eaorta) were obtained in the precontrast and equilibrium phase CT images. fECV was calculated using the following equation: fECV [%] = Etumor/Eaorta × (100 - hematocrit [%]). fECV values were compared between the ICC and HCC groups using Welch's t-test. The diagnostic performance of fECV for differentiating ICC and HCC was assessed using receiver-operating characteristic (ROC) analysis. fECV and the CT imaging features of tumors were evaluated by two radiologists. Multivariate logistic regression analysis was performed to identify factors predicting a diagnosis of ICC.

Results

Mean fECV was significantly higher in ICCs (43.8% ± 13.2%) than that in HCCs (31.6% ± 9.0%, p < 0.001). The area under the curve for differentiating ICC from HCC was 0.763 when the cutoff value of fECV was 41.5%. The multivariate analysis identified fECV (unit OR: 1.10; 95% CI: 1.01-1.21; p < 0.05), peripheral rim enhancement during the arterial phase (OR: 17.0; 95% CI: 1.29-225; p < 0.05), and absence of washout pattern (OR: 235; 95% CI: 14.03-3933; p < 0.001) as independent CT features for differentiating between the two tumor types.

Conclusions

A high value of fECV, peripheral rim enhancement during the arterial phase, and absence of washout pattern were independent factors in the differentiation of ICC from HCC.

Three-Year Outcomes of a Phase II Study of Perioperative Capecitabine Plus Oxaliplatin Therapy for Clinical SS/SE N1-3 M0 Gastric Cancer (OGSG 1601)

Background

We previously reported the good feasibility and favorable efficacy of perioperative capecitabine plus oxaliplatin (CapeOx) in patients (pts) with clinical T3(SS)/T4a(SE) N1-3 M0 gastric cancer (GC) in a phase II study in which the pathological response rate, the primary endpoint, of 54.1% was demonstrated. Here, we report 3-year follow-up data.

Methods

The eligibility criteria included clinical T3(SS)/T4a(SE) N1-3 M0 GC according to the Japanese Classification of Gastric Carcinoma-3rd English Edition (JCGC). Three cycles of neoadjuvant CapeOx (capecitabine, 2000mg/m² for 14 days; oxaliplatin, 130mg/m² on day 1, every 3 weeks) were administered, followed by 5 cycles of adjuvant CapeOx after D2 gastrectomy. Three-year overall survival and relapse-free survival are presented here, and analyzed by cohorts based on pathologic response rate (pRR).

Results

Thirty-seven pts were enrolled from July 2016 to May 2017, and fully evaluated for efficacy and toxicity. Thirty-three pts (89.2%) completed the planned three cycles of neoadjuvant CapeOx and underwent gastrectomy, with an R0 resection rate of 78.4% (n = 29). The overall survival (OS) rate and relapse-free survival (RFS) rate at 3 years was 83.8% (95% CI, 72.7-96.5%) and 73.0% (95% CI, 60.0-88.8%), respectively. Further, the 3-year OS rate in pts with pathological response of grade 1a (n = 13) and grade 1b or higher (n = 20) was 69.2% (95% CI: 48.2-99.5%) and 100.0%, respectively, based on JCGC. Pathological response rate was classified according to JCGC as follows: grade 0, the tumor was not affected; grade 1a, less than one-third of the tumor was affected; grade 1b, one to two thirds of the tumor was affected; grade 2, greater than or equal to two thirds was affected; and grade 3, no residual tumor. A pathological response was defined as grade 1b or greater.

Conclusion

Perioperative CapeOx showed good feasibility and favorable prognosis, especially in pts with pathological response of grade 1b or higher and was found to be useful in predicting prognosis. The data obtained using this novel approach warrant further investigation (Trial ID: UMIN000021641, jRCTs051180109).

A phase II study of perioperative capecitabine plus oxaliplatin for clinical SS/SE N1-3 M0 gastric cancer (OGSG1601)

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Background: D2 gastrectomy followed by adjuvant S-1 is one of the standard therapy for the patients (pts) with stage III gastric cancer (GC) in Japan; however, the outcome is not satisfactory. We examined the efficacy of perioperative capecitabine and oxaliplatin (CapeOx) in pts with clinical SS/SE N1-3 M0 GC. Methods: The eligibility criteria included histopathologically confirmed clinical T3(SS)/T4a(SE) N1-3 M0 GC according to the Japanese Classification of GC (JCGC; 3rd English Edition). Three cycles of neoadjuvant CapeOx (NAC; capecitabine, 2,000 mg/m2 for 14 days; oxaliplatin, 130 mg/m2 on day 1, every 3 weeks) were administered, followed by five cycles of adjuvant CapeOx after D2 gastrectomy. The primary endpoint was the pathological response rate (pRR) according to JCGC ( ≥Grade 1b). Results: Thirty-seven pts were enrolled from April 2016 to May 2017, and fully evaluated for efficacy and toxicity. Thirty-three pts (89.2%) completed the planned three cycles of NAC and underwent gastrectomy, with an R0 resection rate of 78.4% (n = 29) and a pRR of 54.1% (n = 20, p = .058; 90% confidence interval [CI], 39.4–68.2) were demonstrated. The relative dose intensity (RDI) of capecitabine and oxaliplatin were 90.5% and 91.9%, respectively. Among 27 pts who initiated AC, 21 (63.6%) completed the treatment, and the RDI of capecitabine and oxaliplatin were 80.9% and 65.1%, respectively. Grade 3–4 toxicities during NAC included neutropenia (8%), thrombocytopenia (8%), and anorexia (8%) and during AC included neutropenia (37%), diarrhea (4%), and anorexia (4%), but no treatment-related death was reported. The overall survival (OS) rate and relapse free survival (RFS) rate at 3 years was 83.8% (95% CI, 72.7-96.5%) and 73.0% (95% CI, 60.0-88.8%), respectively. Subgroup analyses according to residual tumor after surgery (R status) showed a 3-year OS and RFS rate of 86.2% (95% CI, 74.5-99.7%) and 75.7% (95% CI, 63.0-90.8%) for R0. Conclusions: Perioperative CapeOx showed good feasibility and favorable prognosis with sufficient pathological response, although statistical significance at .058 did not reach the commonly accepted cutoff of .05. The data obtained using this novel approach warrant further investigations. Clinical trial information: 000021641.

Multicenter phase II study of neoadjuvant chemotherapy with S-1 and oxaliplatin for locally advanced gastric cancer (Neo G-SOX PII)

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Background: Prognosis for locally advanced gastric cancer (LAGC), such as clinical T4 disease, bulky nodal metastases, type 4 and large type 3 gastric cancer, was not satisfactory even by D2 gastrectomy followed by adjuvant chemotherapy. Neoadjuvant chemotherapy is another promising approach, therefore, we have conducted a phase II study to evaluate the efficacy and safety of the neoadjuvant chemotherapy of S-1 and oxaliplatin (G-SOX) followed by gastrectomy with D2/3 lymph node dissection for LAGC, and the primary endpoint of curative resection rate was met [Miki A, ESMO 2019]. We show longer follow-up data from this study. Methods: Patients with adenocarcinoma of the stomach; clinical T4; clinically resectable gastric cancer of type 4 or large type 3; bulky nodal involvement around major branched arteries to the stomach were enrolled. Patients receive two cycles of neoadjuvant chemotherapy with S-1 (80 mg/m2, p.o., days 1-14 followed by 1 week rest) and oxaliplatin (130 mg/m2 at day 1), followed by D2 or higher surgery with no residual disease. Patients with pathological R0/1 resection received S-1 (80 mg/m2, p.o., days 1-28 followed by 2 week rest) for 1 year as adjuvant chemotherapy. Primary endpoint was curative resection rate. Results: Between August 2015 and March 2017, forty-one patients were in enrolled. Of the patients, 39 patients (95%) completed the two courses of neoadjuvant chemotherapy of G-SOX, 37 (90%) received gastrectomy, and 36 (87.8%) received curative resection (R0/1). Grade 3 or higher toxicities during neoadjuvant chemotherapy of G-SOX were neutropenia (7%), fatigue (7%), diarrhea (5%) and thrombocytopenia (2%). No treatment related deaths were observed. Surgical complications including postoperative complications were observed in 13 patients (35%). Pathological response rate after neoadjuvant G-SOX was 40%. With a median follow-up period of 33.8 months, 3year-relapse free survival and 3year-ovearll survival was 54.3% and 73.1%, respectively. Conclusions: An update analysis confirmed that neoadjuvant chemotherapy of G-SOX is a feasible and might be one of the promising strategies for patients with LAGC. Clinical trial information: UMIN000018661.

A pathological complete response by chemotherapy with S-1 and oxaliplatin for a locally advanced duodenal adenocarcinoma in Lynch syndrome: a case report

BACKGROUND

Although primary duodenal adenocarcinoma (DA) is a rare malignancy representing ~ 0.5% of all gastrointestinal cancers, the incidence of DA is more frequent in Lynch syndrome. Because of its rarity, treatment strategies or optimal chemotherapeutic regimens have not been clearly defined for advanced DA.

CASE PRESENTATION

A 72-year-old woman with Lynch syndrome visited our hospital with a right upper abdominal pain. Computed tomography (CT) showed wall thickness with enhancement in the second portion of the duodenum and adjacent abdominal wall, which suggested direct tumor invasion to the abdominal wall. Upper gastrointestinal endoscopy (UGE) showed a large ulcerative tumor in the second portion of the duodenum, and histological analysis revealed a poorly differentiated adenocarcinoma. A cT4N0M0, cStage IIB (Union for International Control Cancer TNM staging) DA was diagnosed. After three courses of chemotherapy with S-1 and oxaliplatin (SOX), follow-up CT and UGE showed shrinkage of the duodenal tumor. Therefore, the patient underwent pancreaticoduodenectomy with lymph node dissection with curative intent. Histological examination showed a pathological complete response to SOX therapy. The postoperative course was uneventful, and the patient was discharged on postoperative day 29. The patient received no adjuvant chemotherapy, and there has been no evidence of recurrence 6 months after the operation.

CONCLUSIONS

SOX therapy provided a remarkable response and can be an optimal chemotherapeutic regimen for advanced DA in Lynch syndrome.

A Phase II Study of Perioperative Capecitabine plus Oxaliplatin Therapy for Clinical SS/SE N1-3 M0 Gastric Cancer (OGSG 1601)

LESSONS LEARNED

Perioperative capecitabine and oxaliplatin (CapeOx) therapy showed favorable efficacy with sufficient pathological response. Small sample size limited the statistical power of this result. Perioperative CapeOx therapy showed good feasibility. Further studies with larger sample size are required to validate this novel approach.

BACKGROUND

D2 gastrectomy followed by adjuvant S-1 is the standard therapy for patients (pts) with stage III gastric cancer (GC) in Japan; however, the outcome is not satisfactory. We examined the efficacy of perioperative capecitabine and oxaliplatin (CapeOx) in pts with GC.

METHODS

The eligibility criteria included confirmed clinical T3(SS)/T4a(SE) N1-3 M0 GC according to the Japanese Classification (JCGC; 3rd English Edition). Three cycles of neoadjuvant CapeOx (NAC; capecitabine, 2,000 mg/m² for 14 days; oxaliplatin, 130 mg/m² on day 1, every 3 weeks) were administered, followed by five cycles of adjuvant CapeOx (AC) after D2 gastrectomy. The primary endpoint was the pathological response rate (pRR) according to the JCGC (≥grade 1b).

RESULTS

Thirty-seven pts were enrolled on CapeOx. An R0 resection rate of 78.4% (n = 29) and a pRR of 54.1% (n = 20, p = .058; 90% confidence interval [CI], 39.4-68.2) were demonstrated. Among 27 pts who initiated AC, 21 (63.6%) completed the treatment. Grade 3-4 toxicities during NAC included neutropenia (8%), thrombocytopenia (8%), and anorexia (8%) and during AC included neutropenia (37%), diarrhea (4%), and anorexia (4%).

CONCLUSION

Perioperative CapeOx showed good feasibility and favorable efficacy with sufficient pathological response, although statistical significance at .058 did not reach the commonly accepted cutoff of .05. The data obtained using this novel approach warrant further investigations.

Metabolic tumor volume of metastatic lymph nodes and survival after total laryngectomy in laryngeal and hypopharyngeal cancer

OBJECTIVES

The prognostic value of metabolic tumor volume (MTV) in locally advanced laryngeal or hypopharyngeal cancer is established in the setting of chemoradiotherapy, while it remains unknown in the setting of upfront total laryngectomy.

MATERIALS AND METHODS

We retrospectively analyzed 88 patients receiving total laryngectomy and neck dissection, using Cox regression models.

RESULTS AND CONCLUSION

Variables related to metastatic lymph node were associated with overall survival, whereas those related to primary tumor were not. In multivariable models, MTV of metastatic lymph nodes (N-MTV) as a continuous variable (Akaike's information criterion (AIC), 277.5) was equivalent to pathological nodal status (AIC, 278.2; P = 0.40), and superior to pathological nodal classification as an ordinal variable (AIC, 281.4; P < 0.05) in ability of predicting death. The risk of death was increased by 1.2-fold (95% confidence interval (CI), 1.0-1.4; P = 0.03) every 10-ml increment of N-MTV, while patients with pN+ disease were at a higher risk of death by 2.9-fold (95% CI, 1.0-12.2; P < 0.05) compared with patients with pN0 disease. Using recursive partitioning analysis (RPA), we classified the patients as having a low, intermediate, or high risk of death on the basis of N-MTV and extranodal extension (ENE). This RPA classification system exhibited greater concordance with overall survival than the classification considering pathological nodal status and ENE (AIC, 275.8 versus 281.4; P = 0.02). In the setting of upfront total laryngectomy, N-MTV is a critical predictor of mortality. A staging system in which N-MTV is incorporated may better inform adjuvant treatment decisions.

Impact of number of [(18)F]fluorodeoxyglucose-PET-positive lymph nodes on survival of patients receiving neoadjuvant chemotherapy and surgery for oesophageal cancer

BACKGROUND

[(18) F]fluorodeoxyglucose (FDG)-PET has been used to evaluate the response of primary tumours to neoadjuvant therapy for oesophageal cancer. The clinical significance of the number of PET-positive nodes before and after therapy has not been investigated previously.

METHODS

[(18) F]FDG-PET was performed before and 2-3 weeks after completion of neoadjuvant chemotherapy to identify the number of PET-positive nodes, and these numbers were assessed in relation to metabolic changes in the primary tumour.

RESULTS

Of 302 patients in total, 90 had no PET-positive nodes, 83 had one, 59 had two and 70 patients had three or more positive nodes before therapy. After treatment, the numbers were: none in 207 patients, one in 59, two in 20 and three or more in 16 patients. The number of PET-positive nodes after treatment was influenced by both the number of PET-positive nodes before therapy and the response to preoperative therapy, and correlated with the number of metastatic lymph nodes. Overall survival was longer in patients who had no PET-positive nodes after treatment than in those who had one or more. Multivariable analysis identified the numbers of PET-positive nodes before and after chemotherapy as independent prognostic factors, together with clinical response, tumour depth and lymph node involvement.

CONCLUSION

The number of PET-positive nodes after treatment correlated with survival in patients with oesophageal cancer who underwent neoadjuvant chemotherapy.

Long-term survival outcomes of advanced gastric cancer patients who achieved a pathological complete response with neoadjuvant chemotherapy: a systematic review of the literature

BACKGROUND

A pathologic complete response (pCR) can sometimes be induced by intensive or long-term neoadjuvant chemotherapy (NAC). This prognostic research study based on a systematic review of the literature evaluated the impact of a pCR on the long-term survival of gastric cancer (GC) patients.

METHODS

Articles were extracted from PubMed and the Japanese medical search engine "Ichu-shi," using the terms "GC," "NAC," and "pCR." Articles were selected based on the following criteria: (1) full-text case report, (2) R0 resection following NAC for locally advanced GC, and (3) pathological complete response in both the primary stomach and in the lymph nodes. A questionnaire regarding the patients' prognoses was sent to the corresponding authors of the articles selected in July 2013.

RESULTS

Twenty-four articles met the criteria. Twenty authors responded to the questionnaire. Finally, 22 patients from 20 articles were entered into the present study. The median follow-up time (range) of the survivors was 76 (range 13-161) months. Tumors that were stage III/IV (86%: 19/22) and of an undifferentiated histology (61.9%: 13/21) were dominant. An S1-based regimen was frequently selected for the NAC. All patients underwent R0 resection and D2/D3 lymphadenectomy. The overall survival and recurrence-free survival rates at 3 and 5 years were 96% and 85% and 91% and 75%, respectively.

CONCLUSIONS

Although a pCR was a relatively rare event, a high pCR rate would be helpful to select the regimen and courses of NAC, especially when the pathological response rates are similar.

[Retrospective analysis of Charlson comorbidity index (CCI)]

Owing to the advance of supportive care and the development of molecular targeted therapies, the elderlies or patients who have comorbidities have been treated more than before. The assessment of the comorbidity is indispensable to select the appropriate treatment or the control of following therapy. Some indices to determine them have been developed in western countries but not in Japan. The index which is used most is the Charlson comorbidity index (CCI). This index has never been evaluated in Japan. So we investigated the utility of the index for Japanese population. We surveyed retrospectively 498 patients aged 65 or more patients with colon cancer, breast cancer, lung cancer that have been treated in our hospital during 2002-2007. According to CCI, patients are classified into three groups and verified 1-year and 3-year survival rate. 1-year survival rate was 76.9% in groups of 0 points, 83.5% in groups of1 -5 points, 75.0% in the group of six or more points respectively (p=0.19). 3-year survival rate were 59.0%, 63.1%, 75.0%, respectively (p=0.46). Multivariate analysis identified age (≥ 50), Sex (man), stage (III and IV) as significant predictors for worse OS at 3-year. However, there was no significant difference in CCI. There are some items which frequency is zero, so the items of CCI may not match to Japanese population. Presence of existing disease is an important factor for the cancer therapy, and it should be evaluated accurately. It is urgently necessary to develop an evaluation method and establish the scale.

[Are the Japanese guidelines for the management of hepatitis B virus reactivation being properly implemented ?]

Hepatitis B virus(HBV)reactivation has been reported as a fatal complication following systemic chemotherapy or other immunosuppressive therapies. The Japanese Guidelines for HBV reactivation were published in 2009. Despite the publication of these guidelines, there have been some reports of fulminant hepatitis B. Therefore, it was suggested that the guidelines were not yet been widely implemented. We investigated whether the guidelines had been implemented in our hospital. After the evaluation, it was determined that 89%of HBV cases were screened for the HBV surface antigen(HBs-Ag). Additionally, the screening for HBV surface antibody(HBs-Ab)and HBV core antibody(HBc-Ab)should be performed in cases negative for HBs-Ag, which was performed in only 17% of HBs-Ag-negative cases. It was concluded that the guidelines had not been implemented in our hospital. Therefore, we conducted educational activities to promote the implementation of the guidelines. Screening tests were performed in all 270 HBV cases between January and June 2013. Two antigen-positive carriers were identified. The rate of HBs-Ag-negative and/or HBc antibody -positive cases was 20.3%. Of these, 76.4%were tested using a DNA quantitative test, but DNA quantification did not increase in any case. HBV reactivation is expected to increase due to the development of new drugs and the use of diverse regimens. All physicians who perform immunotherapy and chemotherapy should immediately participate in educational activities.

Clinicopathological analysis for recurrence of stage Ib gastric cancer (according to the second English edition of the Japanese classification of gastric carcinoma)

BACKGROUND

The prognosis for patients with stage Ib (second English edition of the Japanese classification of gastric carcinoma) gastric cancer is promising, with an expected 5-year survival of 90%. Despite this relatively high survival rate, the outcome for patients who experience recurrence is poor. To date, however, prognostic and recurrence factors for stage Ib gastric cancer are poorly understood, and appropriate adjuvant chemotherapy protocols have not been developed.

METHODS

We retrospectively analyzed data from 86 stage Ib gastric cancer patients who underwent curative gastrectomy to determine the rates and predictive factors of recurrence.

RESULTS

Eleven patients showed recurrence, with a 12.8% 5-year cumulative recurrence rate. Nearly all of these patients were initially histologically diagnosed with poorly differentiated adenocarcinoma. Based on univariate analyses, recurrence was associated with gender and histological type. Multivariate analyses revealed that the only independent risk factor for recurrence was histologically undifferentiated-type adenocarcinoma. The 5-year survival rate of patients with undifferentiated-type adenocarcinoma was 84%. The predominant recurrence pattern was peritoneal dissemination, and was typically observed 1-3 years post-resection.

CONCLUSION

This retrospective study identified undifferentiated-type adenocarcinoma as the only risk factor for recurrence in stage Ib gastric cancer patients. Although randomized controlled studies are necessary, stage Ib gastric cancer patients with this identified recurrence risk factor would be candidates for adjuvant chemotherapy.

Serological survey of Encephalitozoon cuniculi infection in Japanese dogs

Antibodies to Encephalitozoon cuniculi were examined by enzyme-linked immunosorbent assay using E. cuniculi PTP2 recombinant protein and by Western blot analysis on a total of 472 dog serum samples that had been collected in Japan. Of these samples, 21.8% (103/472) had antibodies against E. cuniculi. Each of 5 serum samples that showed high (>1.0) or low (<0.1) OD value was selected randomly and further examined by Western blot using E. cuniculi-native antigens. All samples with high OD values reacted with specific E. cuniculi proteins, including an antigen of approximately 35 kDa corresponding with PTP2; sera with low OD values did not recognize this E. cuniculi band. This study is the first to demonstrate the prevalence of E. cuniculi infection in dogs in Japan.

[The new communication system about each patient's treatment from the ward to the chemotherapy center in our hospital]

Because the expert nurse of the chemotherapy center collected his profile from his chart and the hospital summary of nursing and we orientated about the induced chemotherapy regimen to the patient who got it after discharge from the ward former, we could not grasp neither his general condition nor mental status adequately. The merit of the outpatient chemotherapy is the improvement of the quality of life, but the patient feels the solitude and anxiety because of the lack of the medical and nursing staff around him. Then we changed that we have visited the patients to collect their profile and orientate about new regimen on his bedside for the smooth conversion to the outpatient chemotherapy. We visited a-total of 45 patients in 2007. Thirty-eight patients visited before their discharge answered, The orientation of the new chemotherapy before my discharge let me get with a security. The visit also enabled both staffs of the chemotherapy center and the ward to possess the common information of each patient and to do the common nursing. We thought that the visit before discharge was effective for the smooth conversion to the outpatient chemotherapy. We would like to reduce the anxiety of the patients who had chemotherapy and to support their struggle against diseases, cooperating to other department and standardizing our care program.

A randomized phase III trial to determine the efficacy of postoperative antimicrobial prophylaxis in gastric cancer surgery (OGSG0501)

e15576

Background: In Japan, antimicrobial prophylaxis (AMP) is typically administered for 3 to 4 days postoperatively in gastric cancer surgery. This far exceeds the recommended 24h or less laid out by the Centers for Disease Control (CDC) guidelines for the prevention of surgical-site infections, after a clean-contaminated operation. Methods: A multicenter randomized phase III trial was designed to evaluate the effect of postoperative AMP in gastric cancer surgery. Patients (pts) were required to have histologically proven gastric cancer which was curable by distal gastrectomy, be classifiable as ASA 1 or 2, and have adequate organ function. Pts were randomized to: (A) perioperative AMP (cefazolin 1g, at <30min before incision, every 3h intraoperative supplements) plus postoperative AMP (cefazolin 1g, twice daily for 2 postoperative days) or (B) perioperative AMP alone. Pts were stratified by institution and ASA. The primary endpoint was the incidence of surgical site infection (SSI). With 171 pts per arm, this study had 80% power to demonstrate non-inferiority with 5% margin of peri-AMP alone and 0.05 1-sided alpha. Results: 355 patients were recruited (A: 179, B: 176) in 7 centers between June 2005 and December 2007. The surgical-site infection rate was 9.0 percent (16 of 178) for peri-/post AMP and 4.5 percent (8 of 176) for peri-AMP alone, with no significant differences (Fisher's exact test: P=0.14, RR=1.98 [95%CI, 0.89–4.44]), but showing a significant non-inferiority (P<0.001). The remote site infection rate was 3.4 percent (6 of 178) for peri-/post AMP and 5.1 percent (9 of 175) for peri-AMP alone, with no significant differences (P=0.44, RR=0.66 [95%CI, 0.25- 1.70]). Conclusions: This multicenter randomized phase III trial confirms that postoperative AMP is unnecessary in patients undergoing distal gastrectomy for gastric cancer.

No significant financial relationships to disclose.

Pituitary adenylate cyclase-activating polypeptide is associated with schizophrenia

Pituitary adenylate cyclase-activating polypeptide (PACAP, ADCYAP1: adenylate cyclase-activating polypeptide 1), a neuropeptide with neurotransmission modulating activity, is a promising schizophrenia candidate gene. Here, we provide evidence that genetic variants of the genes encoding PACAP and its receptor, PAC1, are associated with schizophrenia. We studied the effects of the associated polymorphism in the PACAP gene on neurobiological traits related to risk for schizophrenia. This allele of the PACAP gene, which is overrepresented in schizophrenia patients, was associated with reduced hippocampal volume and poorer memory performance. Abnormal behaviors in PACAP knockout mice, including elevated locomotor activity and deficits in prepulse inhibition of the startle response, were reversed by treatment with an atypical antipsychotic, risperidone. These convergent data suggest that alterations in PACAP signaling might contribute to the pathogenesis of schizophrenia.

A complex polymorphic region in the brain-derived neurotrophic factor (BDNF) gene confers susceptibility to bipolar disorder and affects transcriptional activity

Previous studies have suggested that genetic variations in the brain-derived neurotrophic factor (BDNF) gene may be associated with several neuropsychiatric diseases including bipolar disorder. The present study examined a microsatellite polymorphism located approximately 1.0 kb upstream of the translation initiation site of the BDNF gene for novel sequence variations, association with bipolar disorder, and effects on transcriptional activity. Detailed sequencing analysis revealed that this polymorphism is not a simple dinucleotide repeat, but it is highly polymorphic with a complex structure containing three types of dinucleotide repeats, insertion/deletion, and nucleotide substitutions that gives rise to a total of 23 novel allelic variants. We obtained evidence supporting the association between this polymorphic region (designated as BDNF-linked complex polymorphic region (BDNF-LCPR)) and bipolar disorder. One of the major alleles ('A1' allele) was significantly more common in patients than in controls (odds ratio 2.8, 95% confidential interval 1.5-5.3, P=0.001). Furthermore, a luciferase reporter gene assay in rat primary cultured neurons suggests that this risk allele (A1) has a lower-transcription activity, compared to the other alleles. Our results suggest that the BDNF-LCPR is a functional variation that confers susceptibility to bipolar disorder and affects transcriptional activity of the BDNF gene.

Possible association between nonsynonymous polymorphisms of the anaplastic lymphoma kinase (ALK) gene and schizophrenia in a Japanese population

We examined, for the first time, the possible association between schizophrenia and the anaplastic lymphoma kinase (ALK) gene which plays an important role in neurodevelopment. When two nonsynonymous polymorphisms (Arg1491Lys and Glu1529Asp) were examined, there were significant differences in genotype and allele distributions between patients and controls. Individuals homozygous for the minor allele (1491Lys-1529Asp) were more common in patients than in controls (p = 0.0064, odds ratio 2.4, 95% CI 1.3-4.6). These results suggest that genetic variations of the ALK gene might confer susceptibility to schizophrenia.

Association study of the frizzled-3 (FZD3) gene with schizophrenia and mood disorders

Two research groups have recently reported a significant association between schizophrenia and genetic variants of Frizzled-3 (FZD3) gene. We examined a possible association in a Japanese sample of schizophrenia, bipolar disorder, unipolar depression and controls with four single nucleotide polymorphisms (SNPs), tested in previous reports. We failed to find significant association in the four SNPs or haplotype analysis. The FZD3 gene might not play a role in conferring susceptibility to major psychosis in our sample.

Radionuclide imaging metabolic activity of brown adipose tissue in a patient with pheochromocytoma

We describe a patient with extra-adrenal pheochromocytoma and high plasma norepinephrine levels. Radionuclide images of this patient obtained using (18)F-fluorodeoxyglucose and (123)I-metaiodobenzylguanidine revealed bilateral tracer accumulation in the shoulder and lower neck. The regions of radiotracer uptake corresponded to the location of human brown adipose tissue (BAT). Excessive sympathetic stimulation by high circulating catecholamine concentrations augmented the metabolic activity and tracer uptake in the BAT. This study showed that radionuclide imaging can noninvasively visualize human BAT in terms of metabolic and functional activity.

Analysis of enhancer activity of a dinucleotide repeat polymorphism in the neurotrophin-3 gene and its association with bipolar disorder

Growing evidence has implicated the possible involvement of neurotrophins in the pathogenesis of functional psychoses such as schizophrenia and bipolar disorder. Previous studies reported a significant association of a dinucleotide repeat polymorphism of the neurotrophin-3 (NTF3) gene with schizophrenia. The aims of the present study were to examine whether this polymorphism is associated with bipolar disorder and whether the polymorphic region has an enhancer/silencer effect on transcriptional activity in an allele-dependent manner. In an association analysis between the polymorphism and bipolar disorder in a Japanese sample of 88 patients and 98 controls matched for age, sex, and ethnicity, the distribution of alleles did not differ significantly between the two groups. pGL3-promoter luciferase reporter vectors containing the polymorphic region increased luciferase activity relative to empty pGL3-promoter vector in HeLa, IMR-32 (neuroblastoma) and Hs683 (glioma) cell lines; however, no significant difference was detected between alleles for either cell line. Our results suggest that the examined polymorphism has no major role in giving susceptibility to bipolar disorder. Although the polymorphic region may have an enhancer-like effect on transcriptional activity, we obtained no evidence for allele-dependent differential effects.

Association analysis of the ?308G > A promoter polymorphism of the tumor necrosis factor alpha (TNF-?) gene in Japanese patients with schizophrenia

Two research groups have thus far reported a significant association between schizophrenia and a promoter polymorphism (-308G > A) of the gene encoding tumor necrosis factor alpha (TNF-alpha), while contradictive negative results have also been reported. We examined the possible association in a Japanese sample of 297 schizophrenia cases and 458 controls. Allele frequencies of both the patients and controls were very low (1.5% and 0.8%, respectively), and the difference was not statistically significant. We conclude that the effect of the -308G > A polymorphism on the development of schizophrenia is, if any, weak and the majority of Japanese schizophrenics are unrelated to the -308G > A polymorphism of the TNF-alpha gene.

Gamma camera coincidence imaging with [18F]fluorodeoxyglucose in the pretreatment evaluation of patients with oesophageal cancer

This study investigated the role of [18F]fluorodeoxyglucose (FDG) dual-head gamma camera coincidence imaging (GCI) in the pretreatment evaluation of patients with oesophageal cancer. Twenty-two patients (20 men; mean age, 64 years) with untreated, biopsy proven squamous cell carcinoma of the oesophagus underwent positron emission tomography (PET) and GCI 1 and 3 h after a single injection of FDG, respectively. Computed tomography (CT) was performed within 2 weeks of the FDG imaging. The sensitivity of lesion detection was compared between GCI and PET. Regional (N) and distant (M) metastases detected by GCI were evaluated with reference to PET and CT. The staging obtained by each modality was also compared with pathological staging in nine patients who underwent surgery. FDG PET detected 22 primary tumours, 34 metastatic lymph nodes and four organ metastases. Of them, GCI detected all primary tumours, 24 (71%) metastatic lymph nodes, and none of the organ metastases. Lymph nodes missed by GCI were smaller in size and the majority of them were located in the thoracic region. GCI provided N and M staging identical to CT and PET in eight patients and improved staging over CT in four patients. On the other hand, GCI missed metastases detected by both PET and CT in five patients. The addition of GCI to CT could improve detection of patients with metastasis to 82% (18/22) compared with 64% (14/22) detected by CT alone. In patients with pathological staging (n = 9), GCI could influence management changes in two patients (22%). In conclusion, FDG GCI has a role that is complementary to CT in the initial staging of patients with oesophageal cancer, and due to the additional detection of nodal metastasis, GCI can provide staging information, which may influence changes in management.

Perceptibility curves for the Digora system

OBJECTIVES

To construct perceptibility curves (PCs) for given calibration settings in order to define psychophysical properties of the Digora storage phosphor system and to evaluate the effects of automatic exposure correction (AEC) on the PCs.

METHODS

The Digora system was calibrated at two exposures, 80 microC kg(-1) (high calibration) and 40 microC kg(-1) (low calibration). Since the grey levels displayed in the radiographs are adjusted by AEC, dose-response functions at high calibration were obtained using AEC on and off modes. The dose-response function at low calibration was obtained with AEC off. The PC at each experimental setting was calculated using known physical parameters of the system and the performance of the average observer used in a previous study. In addition, PCs were also constructed using transmitted radiation flux behind the test object calculated from the attenuation coefficient in order to study observer and system performance. PCs obtained under these conditions were compared.

RESULTS

The PC using calculated transmitted radiation flux behind the test object showed a wide plateau at the peak owing to AEC, while the PC obtained by a modified approach showed a higher but narrower peak. There were no differences between the two PCs using AEC on and off modes when the PCs were constructed using a modified approach. There were no differences between the two PCs obtained at high and low calibration settings or between the three PCs obtained with AEC on except for the position along the exposure axis.

CONCLUSIONS

Psychophysical properties of the Digora system may be determined if we employ registered exposures from a dose-response function with AEC off under a given calibration setting. Under these circumstances the shape and height of the PCs will be unchanged irrespective of the AEC mode.

Association study of C825T polymorphism of the G-protein b3 subunit gene with schizophrenia and mood disorders

Alterations of G proteins have been implicated in major psychiatric illnesses. A C825T polymorphism of a gene encoding the beta3 subunit of heterotrimeric G proteins (GNB3) was reported to be associated with several pathological conditions, such as hypertension and depressive disorder. We examined whether this polymorphism is associated with functional psychoses in a Japanese sample of 370 schizophrenics, 164 bipolars, 68 depressive patients, and 198 controls. We obtained no evidence for an association of the polymorphism with any diagnostic group.

Requirement of nef for HIV-1 infectivity is biased by the expression levels of Env in the virus-producing cells and CD4 in the target cells

The nef gene of human immunodeficiency virus type 1 (HIV-1) encodes a 27 to 34 kDa myristoylated protein, which enhances viral infectivity in a single-round infection assay. The level of Nef enhancement of HIV-1 infectivity depends on the viral strains, on the target cells, and on the cells used for propagating the viruses. In this study, we aimed at clarifying the molecular basis of these differences in the requirement for Nef. We found that the requirement for Nef was increased when we decreased the quantity of Env protein in the virus-producing cells or the quantity of CD4 in the target cells. Both the wild-type and Nef-defective HIV-1 viruses were propagated in 293T cells, which did not express any CD4; therefore, Nef-induced CD4 down-regulation did not explain this phenomenon. Moreover, we did not observe any increase in the viral entry or fusion activity of gp120env in the wild-type HIV-1 compared to that in the Nef-defective HIV-1. Thus, we propose that Env on the virion and CD4 on the target cells have inhibitory effects on the post-entry step of the HIV-1 replication cycle, and that Nef functions to counteract this negative effect.

Effects of iterative reconstruction on image contrast and lesion detection in gamma camera coincidence imaging in lung and breast cancers

To investigate the effects of iterative reconstruction in 18F-fluorodeoxyglucose (FDG) gamma camera coincidence imaging (GCI), image contrast and visual detection obtained by using the iterative ordered-subsets expectation maximization (OSEM) reconstruction, in a phantom and in patients with lung cancer and breast cancer, were compared with those obtained by using the conventional filtered backprojection (FBP) reconstruction. Images of a cylindrical phantom containing hot spheres of various sizes (10-38 mm) were acquired by positron emission tomography (PET) and GCI at various sphere-to-background activity ratios. Forty-one consecutive patients with biopsy-proven cancer of lung (n = 20) and breast (n = 21) underwent PET and GCI on the same day after intravenous injection of 370 MBq of FDG. GCI images reconstructed by the OSEM and the FBP were compared. FDG PET was considered as the standard of reference. In GCI phantom images, OSEM yielded better contrast and signal-to-noise ratio (SNR) than FBP over the range of sphere sizes. Attenuation correction improved both the image measures and sphere detection obtained by the OSEM in GCI. In the study involving patients, FDG PET depicted 41 primary tumours and 25 metastatic lymph nodes. All of the tumours >2 cm in diameter (n = 25), six of the nine tumours 1.5-2.0 cm in diameter (67%), two of seven tumours <1.5 cm in diameter (29%), and 20 metastatic lymph nodes (80%) were detected in attenuation uncorrected GCI reconstructed by the OSEM as well as the FBP. The undetected lesions in GCI were identical between the OSEM and the FBP reconstructions. OSEM yielded significantly greater tumour-to-background (T/B) ratios and lower noise than FBP in GCI (T/B ratios, 4.1+/-3.2 vs 3.7+/-2.7, P = 0.02; noise, 0.09+/-0.04 vs 0.14+/-0.05, P<0.0001). In conclusion, OSEM yielded better image contrast and less noise than the FBP in GCI, but the lesion detection obtained by the OSEM and the FBP in attenuation uncorrected GCI in patients with lung cancer and breast cancer were similar. Phantom data suggest the potential of OSEM for improving lesion detection in GCI after attenuation correction.

Feasibility of a short acquisition protocol for whole-body positron emission tomography with fluorine-18 fluorodeoxyglucose

The conventional protocol for whole-body positron emission tomography (PET) with fluorine-18 fluorodeoxyglucose (FDG) requires a total acquisition time of 40-60 min, which is inconvenient for many oncological patients owing to fatigue and discomfort. This study examined the feasibility of a short protocol for whole-body PET. A phantom containing six "hot" spheres of gradually increasing diameter (10-38 mm) was imaged using a dedicated PET scanner for 20, 40, 60, 80, 120 and 600 s at various count rates. Thirty-four patients with various neoplasms underwent whole-body emission scans for 1 min per bed position 1 h after intravenous injection of 370 MBq of FDG (short protocol). A standard simultaneous transmission-emission acquisition for 10 min per bed position was performed thereafter. The images were reconstructed using an iterative algorithm. At a count rate of 40 kcps, which is close to the average count rate obtained in a whole-body FDG PET study, the 60-s image visualised five spheres, of which the smallest was 13 mm in size. Despite the better image quality, lesion detection was not improved in images acquired for more than 60 s (80-600 s). Only three of the six spheres could be detected in images acquired for less than 60 s. In the patient study, the standard protocol visualised 120 tumour lesions, of which 93 (78%) could be detected using the short protocol. Among the non-visualised lesions, 22 (82%) were < or =1.5 cm in size and 17 (63%) were lymph nodes. It is concluded that the proposed short protocol for whole-body FDG PET has a reasonably high detection rate and may be suitable for patients who are unable to undergo scanning for a prolonged period. It may also be useful as a pre-scan guide before a standard whole-body acquisition.

Sensitive detection and differentiation of Sapporo virus, a member of the family Caliciviridae, by standard and booster nested polymerase chain reaction

Norwalk virus and Sapporo virus (SV) were approved as type species of the genus Norwalk-like viruses and the genus Sapporo-like viruses, respectively, in the family Caliciviridae. Nested polymerase chain reaction (PCR), using newly designed primers in the RNA-dependent RNA polymerase region, was developed to detect and differentiate viruses in the three genetic groups of SV based on the relative size of the PCR products obtained. In addition, a booster nested PCR that performs nested PCR in a single tube was introduced to reduce the chance of contamination during the procedure of standard nested PCR. The specificity of the newly developed PCR was confirmed by testing 77 stool specimens and 16 tissue culture fluids derived from growth of unrelated viruses. The sensitivity of the nested PCR was compared with the conventional PCR using Sapp35/Sapp36 primer pair by testing the three cDNA clones obtained from viruses in the SV/SV82, the SV/London92, and the SV/Parkville virus, respectively. This assay can detect SV in a more sensitive way than the conventional PCR and Southern hybridization. Sensitive and suitable methods to detect and differentiate SV are required to obtain accurate epidemiological data on these viruses and the standard and booster nested PCR should be a very useful tool for this purpose.

Establishment of a MAGI-derived indicator cell line that detects the Nef enhancement of HIV-1 infectivity with high sensitivity

The Nef protein of the simian and human immunodeficiency viruses (SIV and HIV) is regarded as one of the critical determinants of the pathogenicity of HIV-1 in vivo. The positive effect of Nef on viral replication is examined most easily in vitro by the use of indicator cells such as HeLa-CD4-LTR-beta-gal cells (MAGI) or MAGIC5 cells, which are MAGI-derived, CCR5-expressing cells. However, Nef increases the infectivity of many HIV-1 strains no more than 10-fold in these indicator cells. It was noted that MAGI cells expressing a lower level of CD4 enabled us to discriminate more clearly between wild-type and Nef-defective virions. A MAGIC5-derived cell line, MAGNEF, which stably expressed a low level of CD4, was established. The infectivity of the Nef-defective HIV-1 NL4-3 strain was consistently less than one-twentieth of that of the wild type in MAGNEF cells. By using MAGNEF cells, it was shown that Nef enhanced the infectivity of a subtype C HIV-1, Indie-C1 strain, although the effect of Nef on Indie-C1 was significantly less than that on the subtype B strains NL4-3 and SF2. These results validate the versatility of MAGNEF cells for use in the simple and sensitive assay for the level of Nef dependence of various HIV-1 isolates.

Clinical severity of Norwalk virus and Sapporo virus gastroenteritis in children in Hokkaido, Japan

OBJECTIVE

To clarify the clinical significance and etiologic impact of Norwalk virus (NV) and Sapporo virus (SV) in viral gastroenteritis in Japanese children.

STUDY DESIGN

Two outbreaks each of NV gastroenteritis and SV gastroenteritis occurring in an infant home in Sapporo, Japan, as well as 95 hospitalized children with acute gastroenteritis were retrospectively evaluated using a 0- to 20-point clinical severity scoring system.

RESULTS

The mean severity scores for NV and SV gastroenteritis outbreaks were 7.9 and 5.2, respectively, as compared with 8.4 for rotavirus A gastroenteritis that occurred in the same infant home. Among 95 hospitalized children with acute gastroenteritis, rotavirus A was detected in 47% followed by NV in 18%. SV was not found.

CONCLUSION

Our data indicate that NV can cause severe gastroenteritis and is an important etiologic agent in hospitalized cases, whereas SV causes mild gastroenteritis in Japanese children.

A novel missense mutation in human lactate dehydrogenase B-subunit gene

Reduced activity of serum lactate dehydrogenase (LDH; EC 1.1.1.27) was found in a male medical student during practical examinations of his own blood. Serum LDH isoenzyme pattern showed reductions in activities of the isoenzymes with lower subunit A/B ratios such as LDH1 and LDH2. These findings were indicative of a partial LDH-B subunit deficiency, which was confirmed in erythrocyte hemolysates by Western blotting. Polymerase chain reaction (PCR)-based DNA sequence analysis of the LDH-B subunit gene revealed a heterozygous nucleotide change: a guanine to adenine substitution in codon 69 (GGG --> GAG) at the third exon of the LDH-B subunit gene that resulted in a glycine to glutamic acid substitution (G69E). The mutation was confirmed by PCR-restriction fragment length polymorphism (RFLP) analysis using a mismatched primer to introduce a new NcoI restriction site. The same heterozygous mutation was found in his mother but not in other family members. This mutation involves a residue belonging to alphaC helix in LDH-B subunit protein molecule that functions as an interface for other subunits.

Infectious DNA clone of HIV type 1 A/G recombinant (CRF02_AG) replicable in peripheral blood mononuclear cells

We constructed an infectious DNA clone of the HIV-1 A/G recombinant 97GH-AG2, which was isolated in Ghana in 1997 and was classified originally as subtype A. By phylogenetic and recombination breakpoint analyses, p97GH-AG2 was grouped in the circulating form of A/G recombinants (CRF02_AG) and was found to contain the least amount of subtype G-derived region among the known CRF02_AG HIV-1 DNAs. This result suggests that CRF02_AG may be a predominant form in Ghana. Virions produced by transfection of p97GH-AG2 into 293T cells grew in phytohemagglutinin-stimulated peripheral blood mononuclear cells (PBMCs). 97GH-AG2 also replicated efficiently in CCR5-expressing HeLa cells, MAGIC5, but only weakly in the parent MAGI cells, indicating that 97GH-AG2 uses mostly CCR5 as a coreceptor. Isolation of the first HIV-1 (CRF02_AG) DNA clone that replicates in PBMCs will accelerate the molecular analysis of this subtype.

Conventional and predicted perceptibility curves for contrast-enhanced direct digital intraoral radiographs

OBJECTIVES

To construct Perceptibility Curves (PCs) for contrast-enhanced digital intraoral radiographs.

METHODS

Radiographs of a test object having holes of increasing depths were exposed using three digital systems, the CDR (Schick Technologies, Long Island, NY, USA), the Dixel (J Morita MFG, Kyoto, Japan) and the Sens-A-Ray (Regam Medical Systems, Sundsvall, Sweden). The radiographs were contrast-enhanced and PCs constructed in the conventional way using 10 observers. Predicted PCs were calculated and compared with observer data.

RESULTS

The PCs showed that contrast enhancement is effective for the perception of small contrast details, especially in the low exposure range. Predicted PCs demonstrated excellent agreement with observer data.

CONCLUSIONS

Contrast enhancement should be advantageous in digital radiography. The effects of contrast enhancement on PCs may be predicted without previous knowledge of observer performance.

Augmentation of human immunodeficiency virus type 1 subtype E (CRF01_AE) multiple-drug resistance by insertion of a foreign 11-amino-acid fragment into the reverse transcriptase

A human immunodeficiency virus type 1 (HIV-1) subtype E (CRF01_AE) variant (99JP-NH3-II) possessing an in-frame 33-nucleotide insertion mutation in the beta3-beta4 loop coding region of the reverse transcriptase (RT) gene was isolated from a patient who had not responded to nucleoside analogue RT inhibitors. This virus exhibited an extremely high level of multiple nucleoside analog resistance (MNR). Neighbor-joining tree analysis of the pol sequences indicated that the 99JP-NH3-II variant had originated from the swarm of drug-sensitive predecessors in the patient. Population-based sequence analyses of 82 independently cloned RT segments from the patient suggested that the variants with the insertion, three or four 3'-azido-3'-deoxythymidine resistance mutations, and a T69I mutation in combination had strong selective advantages during chemotherapy. Consistently, in vitro mutagenesis of a drug-sensitive predecessor virus clone demonstrated that this mutation set functions cooperatively to confer a high level of MNR without deleterious effects on viral replication capability. Homology modeling of the parental RT and its MNR mutant showed that extension of the beta3-beta4 loop by an insertion caused reductions in the distances between the loop and the other subdomains, narrowing the template-primer binding cleft and deoxynucleoside triphosphate-binding pocket in a highly flexible manner. The origin of the insert is elusive, as every effort to find a homologue has been unsuccessful. Taken together, these data suggest that (i) HIV-1 tolerates in vivo insertions as long as 33 nucleotides into the highly conserved enzyme gene to survive multiple anti-HIV-1 inhibitors and (ii) the insertion mutation augments multiple-drug resistance, possibly by reducing the biochemical inaccuracy of substrate-enzyme interactions in the active center.

Isolation and characterization of a full-length molecular DNA clone of Ghanaian HIV type 1 intersubtype A/G recombinant CRF02_AG, which is replication competent in a restricted host range

We have isolated a replication-competent, full-length molecular clone of HIV-1 CRF02_AG, designated p97GH-AG1, by reconstituting two separately amplified genomic regions of an HIV-1 provirus of a 1997 Ghanaian isolate. The phylogenetic and recombination breakpoint analyses revealed that 97GH-AG1 had an A/G recombinant structure similar to that of prototype Nigerian isolate IbNG. The 17-nucleotide insertion downstream of the primer-binding site appeared to be a common sequence signature specific to most CRF02_AG strains, including 97GH-AG1. 97GH-AG1 showed an R5 phenotype and exerted productive infection in both HOS and NP2 cell infectivity assays, whereas it failed to show a detectable level of progeny production in peripheral blood mononuclear cells (PBMCs). The data may suggest the presence of unknown determinant(s) that dictate efficient replication in PBMCs, but that are not required for replication in immortalized cell lines.

Whole-body hybrid PET with 18F-FDG in the staging of non-Hodgkin's lymphoma

PET with a double-head gamma camera (hybrid PET) is a new approach to tumor imaging with 18F-FDG. This study was conducted to clarify the feasibility of whole-body FDG hybrid PET in the staging of non-Hodgkin's lymphoma (NHL) in comparison with PET with a dedicated camera (dedicated PET) and to compare the results of both FDG studies with those of CT and 67Ga scanning as conventional imaging studies (CIS).

METHODS

Thirty patients with NHL were prospectively evaluated. The results of the imaging studies regarding detection of the sites involved and staging were compared with each other and with those of the reference standard based on the final overall clinical evaluation.

RESULTS

Of the total of 206 sites, whole-body FDG hybrid PET and dedicated PET detected 159 sites (77.2%) and 179 sites (86.9%), respectively. Eighteen of the 20 sites missed by hybrid PET alone consisted of lesions < 1.5 cm. Both FDG studies provided concordant staging results in all but 2 patients. CIS, on the other hand, detected 164 (79.6%) of the 206 sites, 137 of which were also detected by hybrid PET. Hybrid PET detected an additional 22 sites not found by CIS, whereas CIS detected 27 additional sites. Hybrid PET and CIS provided concordant staging results in 19 patients. Hybrid PET correctly staged NHL in 5 additional patients, whereas CIS correctly staged NHL in only 1 additional patient.

CONCLUSION

Whole-body FDG hybrid PET appeared to be an accurate method of staging NHL. Despite its poorer image quality compared with dedicated PET, hybrid PET provided NHL staging results comparable with those of dedicated PET. Hybrid PET also yielded results comparable with those of CIS. However, whole-body FDG hybrid PET is currently inadequate as a single modality for staging NHL and is complementary to CT.

Rapid and simple phenotypic assay for drug susceptibility of human immunodeficiency virus type 1 using CCR5-expressing HeLa/CD4(+) cell clone 1-10 (MAGIC-5)

We describe a rapid and simple novel phenotypic assay for drug susceptibility of human immunodeficiency virus type-1 (HIV-1) using a CCR5-expressing HeLa/CD4(+) cell clone 1-10 (MAGIC-5). MAGIC-5 cells produced large amounts of HIV-1 in culture supernatants, which enabled us to perform the phenotypic resistance assay. Determination of HIV-1 susceptibility to various protease inhibitors (PI) and nucleoside reverse transcriptase inhibitors was completed within 15 days in T-cell-tropic (X4) and macrophage-tropic (R5) viruses using fresh plasma samples containing at least 10(4) copies/ml. The nucleotide sequence of the envelope V3 region of HIV-1 in plasma was almost identical to that of the virus isolated by MAGIC-5 cells, suggesting a lack of selection bias in our assay. The assay variability was confined to within five-fold in all drugs examined. Accordingly, we used a 10-fold increase in the 50% inhibitory concentration as the cutoff value for viral resistance in the present assay. HIV-1 resistant to lamivudine, which was not detected by conventional genotypic assays, was isolated. In HIV-1 with PI-associated primary amino acid substitutions, our assay showed that drug resistance profiles correlated well with previously reported genotypic-assay data. Furthermore, our assay provided comprehensive results regarding PI resistance in the presence of multiple mutations. The novel assay successfully quantified the level of resistance of clinical HIV-1 isolates to a battery of anti-HIV drugs, indicating its clinical usefulness, particularly in patients who failed to respond to antiretroviral chemotherapy.

Evaluation of lung cancer by 99mTc-tetrofosmin SPECT: comparison with [18F]FDG-PET

PURPOSE

The purpose of this study was to clarify the validity of (99m)Tc-tetrofosmin SPECT (TF-SPECT) in the evaluation of lung cancer in comparison with [18F]fluorodeoxyglucose ([18F]FDG-PET).

METHOD

Twenty-one patients with biopsy-proven non-small cell lung cancer were examined by both TF-SPECT (early and delayed images) and FDG-PET within a week of each study. Lung cancers were analyzed visually and semiquantitatively using the ratio of lesion to background counts (L/B ratio). Mediastinal lymph node metastases were analyzed only visually.

RESULTS

Both early and delayed TF images could detect 18 of 21 lung cancers on visual analysis (85.7%), whereas FDG-PET could detect all the lesions (100%). The L/B ratio of TF-SPECT was significantly higher in delayed than in early images (1.79 +/- 0.55 vs. 1.56 +/- 0.40; p < 0.001). However, the L/B ratio of FDG-PET was 8.85 +/- 3.05, significantly higher than those of both TF images (p < 0.0001). In the assessment of mediastinal involvement, TF-SPECT was 40.0% sensitive, 100% specific, and 71.4% accurate, whereas FDG-PET was 80.0% sensitive, 81.8% specific, and 81.0% accurate.

CONCLUSION

Although the detection sensitivity was far better than expected, TF-SPECT is not considered to be an alternative to FDG-PET in the evaluation of malignant pulmonary lesions because of its significantly low L/B ratio. TF-SPECT has poor sensitivity for mediastinal lymph node metastases and is useless for staging patients with lung cancer.

Ibudilast modulates platelet-endothelium interaction mainly through cyclic GMP-dependent mechanism

3-Isobutyryl-2-isopropylpyrazolo[1,5-a]pyridine (ibudilast) has been widely used in Japanese clinics for its antiasthmatic and antithrombotic effects. We investigated the mechanisms involved in the antiplatelet effects of the agent, specifically focusing on platelet-endothelium interaction. Ibudilast inhibits both phosphodiesterase (PDE) 3 and 5, the two major PDE isoforms of human platelets, with an IC50 of 31 and 2.2 microM, respectively. Cyclic guanosine monophosphate (GMP) accumulation in washed human platelets exposed to ibudilast alone increased significantly only at high concentrations of the agent (100 microM), whereas > or = 1 microM ibudilast enhanced cyclic GMP levels in the platelets cocultured with bovine aorta endothelial cells (ECs). In contrast, ibudilast enhanced cyclic AMP accumulation only at 100 microM, either with or without ECs. The synergistic effect of ibudilast and EC on cyclic nucleotide accumulation also was demonstrated by the inhibitory capability of the drug and the cells on platelet aggregation. The synergism between ibudilast and aspirin-pretreated ECs was more pronounced than that between ibudilast and N(omega)-nitro-L-arginine (L-NNA)-pretreated ECs. Ibudilast affected neither ATP diphosphohydrolase activity nor NO release from EC up to a concentration of 10 microM. We conclude that ibudilast exhibits antiplatelet properties mainly by inhibiting PDE5 to potentiate antiplatelet function of endothelium-derived NO.

Changes in local cerebral blood flow in photochemically induced thrombotic occlusion model in rats

We demonstrated earlier that in a photochemically induced thrombotic occlusion model, a reperfusion-like phenomenon may be involved in the progress of brain damage. Therefore, we now investigated changes in local cerebral blood flow in a photochemical model compared with changes in a thermocoagulated occlusion model, using autoradiography. At 5 min, and 3, 6 and 24 h after middle cerebral artery occlusion, local cerebral blood flow was measured by intravenous injection of 4-iodo[N-methyl-14C]antipyrine (20 mu Ci). In the ischemic core zone, the reduction in blood flow was similar in the two models. However, blood flow in the ischemic border zone in the photochemical model decreased transiently in the third hour after ischemia and then increased again, while the blood flow in a thermocoagulated model continued to decrease. Time courses of brain damage formation in both models were no different up to 24 h. These findings suggest that the transient reduction in cerebral blood flow in the third hour following ischemia may contribute to a reperfusion-like phenomenon in a photochemical model.