Pi resonance of chemisorbed alkali atoms on noble metals

We have performed a joint experimental and theoretical study of the unoccupied electronic structure of alkali adsorbates on the (111) surfaces of Cu and Ag. Combining angle- and time-resolved two-photon photoemission spectroscopy with wave packet propagation calculations we show that, along with the well known sigma resonance oriented along the surface normal, there exist long-lived alkali-localized resonances oriented parallel to the surface (pi symmetry). These new resonances are stabilized by the projected band gap of the substrate and emerge primarily from the mixing of the p and d Rydberg orbitals of the free alkali atom modified by the interaction with the surface.

Frailty, health-related quality of life and mental well-being in older adults with cardiometabolic risk factors

OBJECTIVE

Frailty is an emergent health-related problem in older adults. The aim of this study was to examine the health-related quality of life (HRQOL) and the effect of frailty in elderly patients with cardiometabolic risk factors.

METHODS

One-hundred and one patients 65 years or older responded to an HRQOL assessment using the World Health Organization Quality of Life (WHOQOL)-26 questionnaire. Frailty was assessed using two indices: the Hebrew Rehabilitation Center for Aged (HRCA) vulnerability index and the Vulnerable Elders Survey (VES) index. In addition, these patients completed self-rating questionnaires assessing mental well-being [the 28-item version of the General Health Questionnaire (GHQ-28)] and depression (Geriatric Depression Scale).

RESULTS

Based on the combination of HRCA and VES indices, 24 subjects (23.7%) met the criteria of frail. Persons > or = 75 years old and those with depressive mood or lower creatinine clearance had significantly lower WHOQOL-26 scores than their counterparts. Diabetes and macrovascular complications did not associate with the WHOQOL-26 scores. Compared with non-frail patients, the frail scored lower on the WHOQOL-26 questionnaire after adjusting for age, kidney dysfunction and depressive mood. Frail patients also reported significantly higher the GHQ-28 scores compared with non-frail patients.

CONCLUSIONS

Frail older adults had a significant lower HRQOL, as well as lower mental well-being, independent of age, diabetes, macrovascular complication, kidney dysfunction and depressed mood.

Establishment of embryonic stem cells secreting human factor VIII for cell-based treatment of hemophilia A

BACKGROUND

Hemophilia A is an X-chromosome-linked recessive bleeding disorder resulting from an F8 gene abnormality. Although various gene therapies have been attempted with the aim of eliminating the need for factor VIII replacement therapy, obstacles to their clinical application remain.

OBJECTIVES

We evaluated whether embryonic stem (ES) cells with a tetracycline-inducible system could secrete human FVIII.

METHODS AND RESULTS

We found that embryoid bodies (EBs) developed under conditions promoting liver differentiation efficiently secreted human FVIII after doxycycline induction. Moreover, use of a B-domain variant F8 cDNA (226aa/N6) dramatically enhanced FVIII secretion. Sorting based on green fluorescent protein (GFP)-brachyury (Bry) and c-kit revealed that GFP-Bry(+)/c-kit(+) cells during EB differentiation with serum contain an endoderm progenitor population. When GFP-Bry(+)/c-kit(+) cells were cultured under the liver cell-promoting conditions, these cells secreted FVIII more efficiently than other populations tested.

CONCLUSION

Our findings suggest the potential for future development of an effective ES cell-based approach to treating hemophilia A.

Helicobacter pylori infection and the risk of Barrett's oesophagus: a community-based study

OBJECTIVE

Gastric colonisation with the Helicobacter pylori bacterium is a proposed protective factor against oesophageal adenocarcinoma, but its point of action is unknown. Its associations with Barrett's oesophagus, a metaplastic change that is a probable early event in the carcinogenesis of oesophageal adenocarcinoma, were evaluated

METHODS

A case-control study was carried out in the Kaiser Permanente Northern California population, a large health services delivery organisation. Persons with a new Barrett's oesophagus diagnosis (cases) were matched to subjects with gastro-oesophageal reflux disease (GORD) without Barrett's oesophagus and to population controls. Subjects completed direct in-person interviews and antibody testing for H pylori and its CagA (cytotoxin-associated gene product A) protein.

RESULTS

Serological data were available on 318 Barrett's oesophagus cases, 312 GORD patients and 299 population controls. Patients with Barrett's oesophagus were substantially less likely to have antibodies for H pylori (OR = 0.42, 95% CI 0.26 to 0.70) than population controls; this inverse association was stronger among those with lower body mass indexes (BMIs < 25, OR = 0.03, 95% CI 0.00 to 0.20) and those with CagA+ strains (OR = 0.08, 95% CI 0.02 to 0.35). The associations were diminished after adjustment for GORD symptoms. The H pylori status was not an independent risk factor for Barrett's oesophagus compared with the GORD controls.

CONCLUSIONS

Helicobacter pylori infection and CagA+ status were inversely associated with a new diagnosis of Barrett's oesophagus. The findings are consistent with the hypothesis that H pylori colonisation protects against Barrett's oesophagus and that the association may be at least partially mediated through GORD.

Phase II study of docetaxel and S-1 combination therapy in patients with previously treated non-small cell lung cancer

18122

Background: Docetaxel is active against chemotherapy-pretreated non-small-cell lung cancer (NSCLC). S-1 is a novel oral fluoropyrimidine, composed of tegafur, 5-chloro-2,4-dihydroxypyridine (dihydropyrimidinedehydrogenase inhibitor), and potassium oxonate (orotate phosphoribosyl transferase inhibitor). It has been commercially available and used for NSCLC in Japan. We conducted this study to evaluate the efficacy and safety of docetaxel combined with S-1 in NSCLC patients (pts) who were previously treated with one or more regimens. Methods: Eligible pts were required to have histologically or cytologically confirmed measurable or evaluable stage IIIB or IV NSCLC, age= 20 years, one or more previous chemotherapy, a performance status (PS) 0–1, and adequate organ function and bone marrow reserve. In this study, pts received S-1 (80 mg/m2 orally on days 1–14) and docetaxel (40mg/m2 IV on days 1). Treatment was repeated every 3 weeks. Results: Between January 2005 and May 2006, 30 pts were enrolled on this study. 29 pts were eligible and evaluable. Median age was 67 (48–79), male/female (23/6), PS 0/1 (9/20), stage IIIB/IV (7/22), and prior chemotherapy regimen 1/2/3 (23/4/2). 28 pts received a platinum-based chemotherapy. Response: PR=7(24%), SD=13, PD=7, NE=2. Median survival time was 10.2 months. Grade 3/4 toxicities (% of pts) were as follows: leukocytes 6/0 (20.6%), neutrophils 7/3 (34.4%), platelets 0/0, infection 0/1 (3.4%), fever 2/0 (6.9%), diarrhea 1/0 (3.4%), neurology 0/1 (3.4%), and mucositis 1/0 (3.4%). There were no treatment-related deaths. Conclusions: The combination of docetaxel and S-1 was effective with acceptable toxicity in pts with previously treated NSCLC. These results warrant further investigations of this regimen a randomized controlled trial as a second-line treatment for NSCLC.

No significant financial relationships to disclose.

Validity of sentinel lymph node biopsy in breast cancer patients after neoadjuvant chemotherapy

11023

Background: Sentinel lymph node biopsy (SLNB) is a potential alternative procedure to conventional axillary lymph node dissection (ALND) in clinically node-negative breast cancer patients. Neoadjuvant chemotherapy (NAC) is a standard of care for patients with locally advanced breast cancer and indications of NAC have been widespread to operable breast cancer patients to facilitate breast conserving surgery. However, the validity of SLNB in breast cancer patients who received NAC is still controversial. Methods: Forty-six patients with stage II or III breast cancer who were treated with NAC from January 2002 to May 2006 were included in the study. Consecutive 122 patients who had SLNB without NAC during the same period were used as a control group. All patients underwent SLNB followed by completion ALND. Sentinel lymph node (SLN) was detected using a combined method of injecting isosulfan blue dye and small-sized technetium- 99m-labeled tin colloid (particle size: 200–400 nm in diameter) peritumorally and subcutaneously. SLNs were evaluated by means of H&E and immunohistochemical staining. Results: SLNs were successfully identified in 42/46 patients (91.3%) treated with NAC and 112/113 patients (99.1%) without NAC (p=0.01). Metastases in the SLNs were found in 16/42 patients (38.1%) with NAC and 32/112 patients (28.6%) without NAC (p=0.2). There were 5 false negative cases (false negative rate: 23.8%) in the NAC group and 2 false negative cases (false negative rate: 5.9%) in the control group (p=0.05). Accuracy of SLNB in the NAC group was also significantly inferior to the control group (88.1% vs. 98.2%, p<0.01). The presence of clinically positive axillary lymph nodes before NAC was not correlated with false negative rate. Conclusions: These data suggest that NAC might be considered a contraindication to SLNB even in patients with clinically negative axillary lymph nodes before NAC.

No significant financial relationships to disclose.

Correlative study of EGFR mutations or protein expressions of EGFR, phosphorylated EGFR, HER2, phosphorylated HER2 and IGFR-1 with gefitinib sensitivity in patients with non-small cell lung cancer: Results of West Japan Thoracic Oncology Group trial (WJTO)

14008

Background: Both epidermal growth factor receptor (EGFR) mutation and gene copy number of HER2, a member of EGFR family, are associated with gefitinib sensitivity. We carried out a correlative study to determine the relationships between EGFR mutations, EGFR or HER2 protein expressions, their activation status (pEGFR, pHER2) or insulin-like growth factor receptor 1 (IGFR-1) protein expressions and clinical outcomes after gefitinib treatment in advanced NSCLC. Method: Tumors from patients (pts) were evaluated for EGFR mutations by DNA sequence, and for protein expressions of EGFR, pEGFR, HER2, pHER2 and IGFR-1 by immuno-histochemistry. Time to progression (TTP) was calculated by the Kaplan-Meier method; groups were compared using the log-rank test. Risk factors associated with TTP were evaluated with Cox proportional hazard regression modeling. Correlation between EGFR mutation and response was evaluated by Fisher’s direct method. Relationship between each protein expression and response was tested by two-sided. Primary endpoint was to detect biomarkers to predict gefitinib sensitivity. Results: From Dec. 2003 to Dec. 2005, 103 consecutive pts were enrolled onto the study, and received gefitinib until disease progression. Median age was 68 years, female (58%), adenocarcinoma (83%), never smoker (55%) and no previous chemotherapy (49%). 98 pts were evaluable for efficacies, toxicities and gene analyses. Forty-one pts (42%) had EGFR mutations; 14 pts had deletional mutation in exon 19, 27 pts had missense mutation (L858R) in exon 21. EGFR mutations were significantly related to response (62 vs. 26%; P = 0.001), disease control rate (92 vs. 65%; P = 0.003) and TTP (median, 10.1 vs. 5.1months; hazard ratio = 0.64; P = 0.048). Both pEGFR (0, +1 vs. =+2; P = 0.002,) and pHER2 (0 vs. =+1; P = 0.001) expressions are significantly associated with incidence of EGFR mutation. Conclusions: EGFR mutation was a significant predictive biomarker of response to gefitinib. Phosphorylated EGFR protein expression is a potent replaceable biomarker for EGFR mutation.

No significant financial relationships to disclose.

Sentinel node mapping for esophageal cancer

4552

Background: Extended radical esophagectomy with three-field lymph node dissection has been recognized as a standard procedure for esophageal cancer in Japan, even for clinically node negative cases. However, a significant increase of morbidity and mortality after the invasive procedure was reported in randomized trials. To eliminate the uniform application of highly invasive surgery, we hypothesized that sentinel node (SN) mapping plays a key role to obtain individual information and allows modification of the surgical procedure for early esophageal cancer. Methods: We have established radio-guided method to detect SNs in patient with early esophageal cancer using endoscopic injection of technetium-99m tin colloid. Preoperative lymphoscintigraphy and intra-operative use of hand held gamma probe were reliable to locate the radioactive SNs. Intra-operative gamma probing was also feasible in thoracoscopic or laparoscopic surgery using a special gamma detector which is introducible from trocar ports. Results: SN mapping has been performed for 105 patients with clinically N0 early esophageal cancer in our institute since 1999. Detection rate of hot node using our procedure was 93% (98/105). The mean number of sentinel nodes per case was 5.1. Thirty-three of 37 cases with lymph node metastasis showed positive sentinel nodes. The sensitivity to detect metastasis based on SN status was therefore 89% in our experience. Accuracy of metastatic status based on SN was 96% (94/98). SNs widely spread from cervical to abdominal areas. In more than 80% of the cases, at least one SN was located in the 2nd or 3rd compartment of regional lymph nodes. Conclusions: Our results suggest that SN concept for clinically N0 early esophageal cancer could be validated, and individualized selective and modified lymphadenectomy targeted on sentinel node basins for clinically N0 early esophageal cancer should become feasible and clinically useful as less invasive surgical procedures.

No significant financial relationships to disclose.

Effect of scatter and attenuation correction in ROI analysis of brain perfusion scintigraphy

The aim of this study was to evaluate the effect of scatter and attenuation correction in region of interest (ROI) analysis of brain perfusion single-photon emission tomography (SPECT), and to assess the influence of selecting the reference area on the calculation of lesion-to-reference count ratios. Patients, methods: Data were collected from a brain phantom and ten patients with unilateral internal carotid artery stenosis. A simultaneous emission and transmission scan was performed after injecting 123I-iodoamphetamine. We reconstructed three SPECT images from common projection data: with scatter correction and nonuniform attenuation correction, with scatter correction and uniform attenuation correction, and with uniform attenuation correction applied to data without scatter correction. Regional count ratios were calculated by using four different reference areas (contralateral intact side, ipsilateral cerebellum, whole brain and hemisphere). Results: Scatter correction improved the accuracy of measuring the count ratios in the phantom experiment. It also yielded marked difference in the count ratio in the clinical study when using the cerebellum, whole brain or hemisphere as the reference. Difference between nonuniform and uniform attenuation correction was not significant in the phantom and clinical studies except when the cerebellar reference was used. Calculation of the lesion-to-normal count ratios referring the same site in the contralateral hemisphere was not dependent on the use of scatter correction or transmission scan-based attenuation correction. Conclusion: Scatter correction was indispensable for accurate measurement in most of the ROI analyses. Nonuniform attenuation correction is not necessary when using the reference area other than the cerebellum.

Effect of scatter and attenuation correction in ROI analysis of brain perfusion scintigraphy: phantom experiment and clinical study in patients with unilateral cerebrovascular disease

The AIM of this study was to evaluate the effect of scatter and attenuation correction in region of interest (ROI) analysis of brain perfusion single-photon emission tomography (SPECT), and to assess the influence of selecting the reference area on the calculation of lesion-to-reference count ratios.

PATIENTS, METHODS

Data were collected from a brain phantom and ten patients with unilateral internal carotid artery stenosis. A simultaneous emission and transmission scan was performed after injecting 123I-iodoamphetamine. We reconstructed three SPECT images from common projection data: with scatter correction and nonuniform attenuation correction, with scatter correction and uniform attenuation correction, and with uniform attenuation correction applied to data without scatter correction. Regional count ratios were calculated by using four different reference areas (contralateral intact side, ipsilateral cerebellum, whole brain and hemisphere).

RESULTS

Scatter correction improved the accuracy of measuring the count ratios in the phantom experiment. It also yielded marked difference in the count ratio in the clinical study when using the cerebellum, whole brain or hemisphere as the reference. Difference between nonuniform and uniform attenuation correction was not significant in the phantom and clinical studies except when the cerebellar reference was used. Calculation of the lesion-to-normal count ratios referring the same site in the contralateral hemisphere was not dependent on the use of scatter correction or transmission scan-based attenuation correction.

CONCLUSION

Scatter correction was indispensable for accurate measurement in most of the ROI analyses. Nonuniform attenuation correction is not necessary when using the reference area other than the cerebellum.

Simultaneous determination of mean pressure and deviatoric stress based on numerical tensor analysis: a case study for polycrystalline x-ray diffraction of gold enclosed in a methanol-ethanol mixture

It is known that the {100} and {111} planes of cubic crystals subjected to uniaxial deviatoric stress conditions have strain responses that are free from the effect of lattice preferred orientation. By utilizing this special character, one can unambiguously and simultaneously determine the mean pressure and deviatoric stress from polycrystalline diffraction data of the cubic sample. Here we introduce a numerical tensor calculation method based on the generalized Hooke's law to simultaneously determine the hydrostatic component of the stress (mean pressure) and deviatoric stress in the sample. The feasibility of this method has been tested by examining the experimental data of the Au pressure marker enclosed in a diamond anvil cell using a pressure medium of methanol-ethanol mixture. The results demonstrated that the magnitude of the deviatoric stress is ∼0.07 GPa at the mean pressure of 10.5 GPa, which is consistent with previous results of Au strength under high pressure. Our results also showed that even a small deviatoric stress (∼0.07 GPa) could yield a ∼0.3 GPa mean pressure error at ∼10 GPa.

Epidermal growth factor receptor mutations and gene amplification in Japanese non-small cell lung cancer patients treated with gefitinib

17063

Background: To evaluate relationship between epidermal growth factor receptor (EGFR) gene status and clinical outcome in patients with non-small-cell lung cancer (NSCLC) treated with gefitinib. Also, to examine an involvement of human papilloma virus (HPV) in EGFR status of these patients. Methods: Twenty seven patients with NSCLC who had relapsed after surgery and received gefitinib were included. Genomic DNA was extracted from the 12 paraffin and the 15 frozen surgical specimens. PCR and sequencing for genotyping were done for EGFR (exon 18–21) and ERBB2 (exon 19–22) and KRAS (exon 1). Gene amplification for EGFR was analyzed by quantitative real-time PCR. HPV was detected by PCR and in-situ PCR. Results: Nine patients (33%) had EGFR mutations; seven patients had deletion mutations in exon 19, one patient had missense mutations (L858R) in exon 21. Two patients had missense mutations (G719S, exon 18 and L838P, exon 21) No mutations were identified in ERBB2 and KRAS. EGFR copy number in the tumor cells ranged from 1.1 to 9.7, and increased EGFR copy numbers (≥3) were observed in six patients ( 22.2%). Two patients (7%) had HPV, and had no mutation and no amplification. Response rate (67% {six of nine patients} v 18% {three of 17 patients}; p = 0.012) was significantly better in patients with EGFR mutations than in patients with wild-type EGFR. Overall survival (median 17 v 9 months) was better in patients with EGFR mutations than in patients with wild-type EGFR. EGFR copy number and presence of HPV were not associated with clinical outcome. Conclusions: EGFR mutations were significantly associated with better clinical outcome in gefitinib treated NSCLC patients.

No significant financial relationships to disclose.

HRCT shows variations in appearance in disseminated tuberculosis in adults

OBJECTIVE

To examine patterns of high resolution computed tomography (HRCT) of lungs of adults with disseminated tuberculosis (TB).

DESIGN

Disseminated TB was defined as radiological involvement of all lung lobes.

RESULTS

The case series illustrated wide variation in HRCT of disseminated TB. Patterns identified on HRCT included (1) miliary TB (haematogenous dissemination), (2) miliary TB with exudative reaction, (3) bronchogenic spread, (4) miliary TB mixed with bronchogenic spread, and (5) bronchogenic spread with multiple cavity formation.

CONCLUSION

The HRCT patterns described allow classification of disseminated TB according to the mechanism of spread (haematogenous and/or bronchogenic) and the degree of local lung involvement (reaction or cavitation).

Evidence of antisense tumor targeting in mice

Even though increased accumulations of radiolabeled antisense DNAs compared to control DNAs are becoming a routine observation in cultured tumor cells, trustworthy evidence of tumor targeting in vivo by an antisense mechanism remains elusive. The goal of this study was to obtain convincing evidence of antisense tumor targeting in nude mice by using two different tumors and both intratumoral (i.t.) and intravenous (i.v.) administration of radiolabeled antisense and control sense DNAs. Both the MDR++ cell line KB-G2 and its parent MDR+ cell line KB-31 were used in this study. The antisense (AS) DNA was directed against the AUG start codon of the MDR1 mRNA and, along with the sense (S) control DNA, was a uniform phosphorothioate administered naked. In previous cell culture studies from our laboratories, the accumulation of this AS DNA was strikingly high in KB-G2 cells and only average in KB-31 cells, a fact we attribute to the 1000-fold higher expression by RT-PCR of MDR1 mRNA in the former cell line. In this study, both DNAs were radiolabeled with (99m)Tc via MAG3 and administered i.t. or i.v. at 1 microg (100 microCi) per animal 24 h prior to sacrifice and dissection in mice bearing thigh tumors of about 1 g. Following i.t. administration, no statistically significant differences (Student's t test, p < 0.05, N = 4) between the AS and S DNA biodistributions in normal tissues were observed except in the KB-G2 mice in which muscle levels were lower for the S control. In contrast, tumor levels in the KB-G2 animals were significantly higher for the AS DNA vs S DNA (14.7 vs 8.5% ID/g) while this difference (8.6 vs 4.3% ID/g) was insignificant in the KB-31 animals. The whole body images obtained just prior to sacrifice clearly show improved targeting of AS DNA vs S DNA in the KB-G2 but not the KB-31 animals. Calculations based on these results show that about 60 000 AS DNAs accumulated specifically (i.e. AS DNA - S DNA) per KB-G2 tumor cell following i.t. administration. When administered i.v. rather than i.t., higher tumor levels in KB-G2 animals compared to KB-31 were not observed, most likely because of the lower dosage reaching the tumors. When the KB-G2 and KB-31 results are combined, no statistically significant differences between the AS and S DNA biodistributions in normal tissues were observed except in blood in which S DNA levels were higher and in spleen in which they were lower. In contrast, tumor levels were significantly higher for the AS DNA vs S DNA (0.100 vs 0.063% ID/g). Calculations based on these results show that about 400 AS DNAs accumulated specifically per tumor cell following i.v. administration. Therefore evidence for tumor targeting in vivo by an antisense mechanism has been obtained in that statistically higher tumor accumulations of the (99m)Tc-AS DNA were observed compared to the control (99m)Tc-S DNA both following i.t. and i.v. administrations. The successful localization of AS DNA in tumor demonstrates that in vivo AS targeting of tumor is feasible although improvements in tumor delivery and normal tissue clearance are needed for practical antisense imaging.

CCL22 and CCL17 in rat radiation pneumonitis and in human idiopathic pulmonary fibrosis

Pulmonary fibrosis is caused by various known and unknown aetiologies, but the key pathogenic mechanisms are still ill-defined. Chemokines are a large family of chemotactic cytokines that play pivotal roles in various inflammatory diseases. In the present study, the roles of chemokines in a rat model of radiation pneumonitis/ pulmonary fibrosis were examined. Accumulation of inflammatory cells and pneumonitis were observed on day 28, and diffuse alveolar wall thickening with extensive fibrosis was observed on day 56. In addition to the previously reported CCL2 (macrophage chemoattractant protein-1) induction, selective upregulation of CCL22 (macrophage-derived chemokine) and CCL17 (thymus and activation-regulated chemokine) were demonstrated for the first time in the irradiated lung tissues. Immunohistochemically, it was demonstrated that CCL22 and CCL17 were localised primarily to alveolar macrophages, whereas their receptor CC chemokine receptor 4 (CCR4) was detected on alveolar lymphocytes and macrophages. On further analysis of bronchoalveolar lavage fluid from patients with idiopathic pulmonary fibrosis and sarcoidosis, elevated levels of CCL22, but not of CCL17, were observed in the idiopathic pulmonary fibrosis patients. Since these two chemokines play pivotal roles in various type-2 T-helper cell-dominant diseases, it was speculated that CCL22, and probably CCL17, are involved in the pathophysiology of radiation pneumonitis/pulmonary fibrosis and idiopathic pulmonary fibrosis through the recruitment of CC chemokine receptor 4-positive type-2 T-helper cells and alveolar macrophages.

Elevation of cytokeratin 19 fragment (CYFRA 21-1) in serum of patients with radiation pneumonitis: possible marker of epithelial cell damage

Cytokeratin 19 fragment (CYFRA 21-1) level in serum have already been documented as a useful tumor marker for lung cancer. In the present study, we hypothesized that CYFRA 21-1 increases in the sera of patients with radiation pneumonitis, resulting from epithelial cell damage. We measured CYFRA 21-1 in the sera of patients with radiation pneumonitis and evaluated the correlation between CYFRA 21-1 level and severity of radiation pneumonitis as well as clinical course. We studied 16 patients diagnosed with radiation pneumonitis associated with primary lung cancer. CYFRA 21-1 levels in the sera of patients with diffuse radiation pneumonitis (n = 6) significantly increased compared to normal smokers (n = 10) or patients with local radiation pneumonitis (n = 10). CYFRA 21-1 values in sera changed according to the progression or improvement of the diffuse radiation pneumonitis. An immunohistochemical study using pulmonary tissues obtained from autopsied patients with radiation pneumonitis demonstrated that the hyaline membrane and proliferating type II pneumocytes were strongly stained by the anti-human cytokeratin 19 antibody. Our data demonstrated that CYFRA 21-1 was increased in patients with diffuse radiation pneumonitis. Since CYFRA 21-1 is widely used as a tumor marker for lung cancer, this evidence should be noted especially in irradiated patients.

Anti-Salmonella activity of (2E)-alkenals

AIMS

This study investigated the effect of a series of naturally occurring aliphatic (2E)-alkenals against Salmonella choleraesuis subsp. choleraesuis ATCC 35640 and evaluated their antibacterial action.

METHOD AND RESULTS

A homologous series of aliphatic (2E)-alkenals from C5-C13 were tested for their antibacterial activity against Salm. Choleraesuis. The antibacterial action of (2E)-alkenals against Salm. choleraesuis increases with increasing carbon chain length. (2E)-Dodecenal (C12) was the most effective against this food-borne bacterium with minimum bactericidal concentration (MBC) of 6.25 microg ml-1 (34 micromol l-1), followed by (2E)-undecenal (C11) with an MBC of 12.5 microg ml-1 (77 micromol l-1). The activity was found to correlate with the hydrophobic alkyl chain length from the hydrophilic aldehyde group. The time-kill curve study showed that (2E)-dodecenal was bactericidal against Salm. choleraesuis at any growth stage.

CONCLUSIONS

The antibacterial activity of (2E)-alkenals against Salm. choleraesuis was found to correlate with the hydrophobic alkyl chain length. The conjugated double bond is not essential in eliciting the activity but is associated with increasing it.

SIGNIFICANCE AND IMPACT OF THE STUDY

Because of their easy availability and wide distribution in many edible plants, (2E)-alkenals can be used as anti-Salmonella agents.

Thallium-201 single-photon emission computed tomography in the detection of retroperitoneal schwannoma

We describe a patient with retroperitoneal schwannoma whose tumour was detectable by 201Tl single-photon emission computed tomography (SPECT). Physiologic uptake in the alimentary tract did not hamper the interpretation on SPECT images. Uptake by the tumour extending along the spinal nerve root was well recognised in axial and coronal images. Our results suggest that 201Tl SPECT may be useful in the detection of retroperitoneal schwannomas.

Genetic susceptibility to thymic lymphomas and K-ras gene mutation in mice after exposure to X-rays and N-ethyl-N-nitrosourea

PURPOSE

Ras activation is one of the major mechanisms for the development of murine thymic lymphomas by radiation and chemical carcinogens. To gain insight into the relationship between genetic susceptibility and ras gene mutation, the frequency and spectrum of ras gene mutation was examined in thymic lymphomas from susceptible and resistant mice.

MATERIALS AND METHODS

K- and N-ras mutations in thymic lymphomas that arose in X-ray-irradiated and N-ethyl-N-nitrosourea (ENU)-treated mice of susceptible C57BL/6, rather resistant C3H and their hybrid B6C3F1 were analysed by polymerase chain reaction-single-strand conformation polymorphism and subsequent DNA sequencing.

RESULTS

C57BL/6 exhibited a higher incidence of thymic lymphomas after exposure to X-rays and ENU than C3H, with B6C3F1 being intermediate. K-ras gene mutations occurred frequently in the pathogenesis of ENU-induced thymic lymphomas in susceptible C57BL/6 as opposed to resistant C3H. The ras mutations were more frequent in ENU-induced thymic lymphomas than X-ray-induced thymic lymphomas, and with the latter, there was no clear evidence for strain differences, suggesting that the genetic susceptibility to X-rays was independent of ras activation. The mutations of K-ras in thymic lymphomas from C57BL/6 were predominantly GGT to GAT in codon 12, whereas this mutation type was never found in those from C3H. No strain difference was observed in the nucleotide sequence or expression levels of O(6)-alkylguanine alkyltransferase, indicating that this enzyme did not account for the genetic susceptibility to ras activation.

CONCLUSIONS

The results indicate that there is a clear strain and carcinogen dependency of K-ras mutation and that the frequency of ras mutation might determine the genetic susceptibility to ENU-induced lymphomagenesis, whereas pathways independent of ras activation might determine the susceptibility to X-ray-induced lymphomagenesis.

Expression of thyroid transcription factor-1 in 16 human lung cancer cell lines

It has been suggested that thyroid transcription factor-1 (TTF-1) is frequently expressed in human lung cancer, especially in adenocarcinoma and small cell lung cancer, and the TTF-1 expression is closely related with the expression of surfactant protein. We hypothesized that TTF-1 is expressed in human lung cancer cell lines and its expression might be related to the expression of surfactant protein. To test this, expressions of TTF-1 and surfactant protein A (SP-A) were immunohistochemically evaluated in 16 human lung cancer cell lines. In addition, expressions of mRNAs for TTF-1 and SP-A were analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR) and sequencing. As a result, nuclear staining of TTF-1 was observed in two of six adenocarcinoma cell lines, none of seven small cell lung cancer cell lines, and none of three squamous lung cancer cell lines. Among the 16 cell lines, six cell lines (PC3, LC2/Ad, A549, RERF-LC-OK, HI1017, and PC9) expressed significant amounts of mRNA for TTF-1. In contrast, cytoplasmic staining of TTF-1 was observed in five of six adenocarcinoma cell lines, in six of seven small cell lung cancer cell lines, and in all three squamous cell lung cancer cell lines. One of the two adenocarcinoma cell lines those showed positive nuclear staining and cytoplasmic SP-A staining released a significant amount of SP-A in culture supernatant. Our present study demonstrates that the frequency of TTF-1 expression in the nucleus was very low in human lung cancer cell lines; however, their cytoplasmic positivities should be further investigated.

Expression of Bcl-2 and Bax in hypokalemic nephropathy in rats

OBJECTIVES

Potassium depletion results in hyperplasia of renal tubular and interstitial cells in humans and animals, and potassium repletion induces rapid regression of hyperplasia. Apoptosis participates importantly in this reduction of cell number, although we have observed tubular and interstitial apoptosis in rats during potassium depletion as well.

METHODS

To investigate mechanisms of apoptosis in this model, we assessed expression of Bcl-2 and Bax, using immunohistochemistry and reverse transcriptase-polymerase chain reaction (RT-PCR).

RESULTS

Cell proliferation identifiable by labeling with 5-bromo 2'-deoxyuridine was prominent in tubular and interstitial cells of the cortex and outer medulla (OM) 7 days after potassium depletion. Simultaneously present apoptotic cells identified by light microscopy, electron microscopy, and nick end labeling were located mainly in the OM. Seven days after potassium repletion, apoptotic cells increased again but proliferating cells decreased. Bcl-2 protein distributed in the tubules of the OM was significantly decreased in potassium-depleted and potassium-repleted rats compared with control rats, while immunoreactivity for Bax protein tended to increase above control levels in potassium-depleted rats. RT-PCR for bcl-2 and bax demonstrated a significant decrease in levels of bcl-2 mRNA in potassium-depleted and potassium-repleted rats relative to those in controls. Expression of bax mRNA in potassium-depleted and potassium-repleted rats tended to increase, while ratios of bcl-2 mRNA to bax mRNA significantly decreased.

CONCLUSIONS

These results suggest that apoptosis is associated with progression and regression of cellular proliferation in hypokalemic nephropathy, and a decrease in Bcl-2 may be involved in promoting this apoptotic process.

Adjuvant pelvic irradiation in patients with pathologic T2b carcinoma of the uterine cervix

Patients with cervical cancer are subject to postoperative adjuvant therapy if the histopathologic examination reveals parametrial involvement. This study evaluated the patterns of failure in patients with pathologic parametrial invasion (pT2b) treated with adjuvant pelvic irradiation. Between April 1985 and March 1997, 45 patients with pT2b cervical cancer were treated with postoperative pelvic irradiation. The median age was 52 years. Preoperative clinical stages were stage Ib in 8 patients, IIa in 4, and IIb in 33. Twenty-three patients had lymph node metastasis. The median total dose of whole pelvic radiation therapy was 50 Gy. Occurrence of pelvic failure or distant metastasis according to the nodal status was examined. None of the 22 patients without lymph node metastasis developed distant metastasis. Among the 23 node-positive patients, 6 developed distant metastasis as an initial failure site. The 5-year overall survival of the entire group was 78%. The actuarial distant metastasis-free rates at 5 years were 73% and 100% for those with and without pelvic lymph node metastasis, respectively (P = 0.016). Results support previous evidence for chemoradiation in patients with pelvic lymph node metastasis. However, it appears that the role of systemic chemotherapy for node-negative pT2b patients is yet to be established.

Effects of food intake and age on the pharmacokinetics of AS-924, a novel ester-type cephem antibiotic. Comparison with cefpodoxime proxetil

The effects of food intake and age on intestinal absorption of AS-924, a novel prodrug-type cephem antibiotic, were examined in 16 healthy adult volunteers (eight young volunteers and eight elderly volunteers) by the cross-over method, using cefpodoxime proxetil (CPOD-PR) as the control drug. The gastrointestinal absorption of AS-924 and CPOD-PR was increased slightly by food intake and the extent of increase was slightly greater after administration of CPOD-PR. The absorption of AS-924 was not affected by age, whereas intestinal absorption of CPOD-PR increased with age. In conclusion, these results confirmed that AS-924 has the unique characteristics as a novel prodrug and that its absorption is less likely to be affected by food intake and age.

Effect of antacid pretreatment on the pharmacokinetics of AS-924, a novel ester-type cephem antibiotic--comparison with cefteram-pivoxil

The effect of pretreatment with ranitidine, an antacid, on the absorption of AS-924, a novel prodrug-type cephem antibiotic derived from ceftizoxime (CTIZ), was examined in eight healthy adult male volunteers by the cross-over method, using cefteram-pivoxil (CTER-PI) as the control drug. The C(max) and area under the concentration (AUC) values and cumulative urinary excretion rate (0-24 h) of cefteram (CTER) after administration of CTER-PI decreased by 32, 38 and 37%, respectively, in the ranitidine pretreatment group whereas those of AS-924 were not affected by the antacid. The urinary levels of pivaloyl-carnitine determined to evaluate the solubility of these antibiotics in the gastrointestinal tract suggested that this was not affected by ranitidine. These results indicate that the absorption of CTER-PI was affected by pretreatment with ranitidine largely due to inactivation of this antibiotic in the gastrointestinal tract at high pH rather than to a decrease in solubility. In contrast, isomerization of AS-924 was hardly induced by the elevation of pH, thus demonstrating that AS-924 was less likely to be affected by pretreatment with antacids.

Substrate-specific diffusion of select dicarboxylates through Chlamydia trachomatis PorB

Chlamydiae contain two porins, MOMP and PorB, that facilitate diffusion of solutes through the outer membrane. MOMP is a general porin that permits the diffusion of a wide variety of compounds including carbohydrates and amino acids. The relative inefficiency of PorB as a general porin and its low abundance in the outer membrane suggest that it may function as a substrate-specific porin. The tricarboxylic acid (TCA) cycle of chlamydiae is incomplete and to function would require the exogenous acquisition of 2-oxoglutarate or glutamate. A liposome-swelling assay for anions as well as an enzyme-linked liposome assay were used to demonstrate the efficient diffusion of dicarboxylates such as 2-oxoglutarate through PorB. These data demonstrate that PorB is a dicarboxylate-specific porin that may feed the chlamydial TCA cycle and provide chlamydiae with carbon and energy production intermediates.

[Clinical significance of sentinel node navigation surgery in the treatment of early gastric cancer]

Radical lymphadenectomy is the standard surgical approach even for early-stage gastric cancer with a relatively low incidence of lymph node metastasis because of the limited sensitivity of diagnostic imaging to detect micrometastasis in regional lymph nodes. The sentinel node (SN) concept is one topic among novel diagnostic procedures for micrometastasis. The SN is defined as the first draining node from the primary lesion and it would be the first site of micrometastasis. SN biopsy has been clinically validated and applied for the surgical treatment of malignant melanoma and breast cancer. Although the feasibility of this technique in other solid tumors including gastric cancer is still controversial, there are several reports demonstrating the diagnostic significance of SN mapping in early gastric cancer. We have established radio-guided SN mapping for early gastric cancer, and the diagnostic accuracy using this procedure in cT1N0 cases reached 98%. The radio-guided method allows us to detect the SN in endoscopic surgery quantitatively and reproducibly. Validation of the SN concept in gastric cancer in a multi-centric clinical trial is essential for clinical application of this procedure, including the establishment of a novel, minimally invasive approach for early-stage gastric cancer.

Laparoscopic detection of sentinel lymph nodes in gastrointestinal cancer: a novel and minimally invasive approach

Although the sentinel node (SN) concept has been validated in malignant melanoma and breast cancer, the application of this concept for other solid tumors, including gastrointestinal (GI) cancer, is still controversial. We have demonstrated the feasibility of radioguided SN mapping during laparotomy in patients with esophageal, gastric, and colorectal cancers. In 188 patients, the SNs identified by this technique had an overall diagnostic accuracy of 96% for regional lymph node metastasis. Aberrant drainage sites that have been called skip metastasis from the primary lesion were detectable using this method. More recently, we have undertaken SN mapping during laparoscopic surgery. A combination of radiotracer and blue dye optimized the identification of SNs that drained GI cancers. Our preliminary data indicate that laparoscopic mapping of the SN is a sensitive intraoperative technique for identifying lymph node micrometastasis, and we believe that it will become an important component of a minimally invasive approach to early-stage GI cancers.

Heparin-binding outer membrane protein of chlamydiae

As an intracellular pathogen, the mechanism by which Chlamydia invade eukaryotic cells represents a cornerstone to understanding chlamydial biology. The ability of chlamydiae specifically to bind heparan sulphate or heparin and the association of this ability to bind and enter mammalian host cells was approached by searching experimentally for chlamydial outer membrane proteins that bind heparin. The 60 000 molecular weight cysteine-rich outer membrane complex protein, OmcB, bound heparin. The ability of OmcB to bind heparin was supported by mapping the region of the protein with heparin-binding capacity and demonstrating that an OmcB synthetic 20-mer peptide from this region specifically bound heparin. Surface localization of OmcB was shown using monospecific antisera specific to the 20-mer OmcB peptide that bound the surfaces of elementary bodies (EB) and by heparin-binding peptide cross-linking of EB surface proteins.

FDG uptake in the morphologically normal thymus: comparison of FDG positron emission tomography and CT

The purpose of this study was to evaluate the correlation between fluorine-18 fluorodeoxyglucose (FDG) thymic uptake and a normal appearing thymus on CT. Non-attenuation corrected FDG positron emission tomography (PET) data from 94 young persons (mean age 25.4 years, range 18-29 years) with a normal thymus diagnosed on CT were retrospectively evaluated. No subject had clinical symptoms suggestive of thymus-related disease or mediastinal tumour (follow-up period 6-69 months). PET images were visually assessed and the count ratio between the thymus and the lung (T/L ratio) was calculated. Increased FDG uptake occurred in 32 (34%) subjects. In these 32 cases, the T/L ratio was 2.86+/-0.49 (range 2.02-3.99). In 86 subjects whose CT images were available to calculate the CT attenuation of the thymus (CAT), the CAT value was -17.5+/-45.7 HU (range -103.6 HU to 79.9 HU). The T/L ratio correlated with the CAT value (r=0.58). CAT values in subjects with positive PET findings were significantly higher than CAT values in subjects with negative PET findings (p<0.001, unpaired t-test). These results suggest that even in young adults, if the thymus has a relatively high CT attenuation value, the presence of physiological thymic uptake in FDG-PET is a normal variant. In this study, the diagnosis of normal thymus was based on CT appearance and clinical course. Further studies are needed to clarify the relationship between histopathology and FDG uptake in the thymus.

[A case of breast cancer with bone marrow and liver metastases responding completely to low-dose weekly paclitaxel combined with toremifene]

A 36-year-old woman was admitted to our hospital because of general malaise in October 1999. She was diagnosed with bilateral breast cancer with bone marrow and liver metastases. Low-dose weekly paclitaxel (60 mg/body/week) combined with toremifene (120 mg/day) was started in December 1999. Myelofunction was recovered after 2 weeks of chemotherapy (CT), and the primary tumors and cervical/axillary lymphadenopathy disappeared after 4 weeks of CT. Bone marrow and liver metastases was no longer detected after 16 weeks of CT, and the case was evaluated as a complete response (CR). The same therapy has been performed for eight months and no evidence of recurrence has been observed.

Inexplicable suppression of hepatic uptake of gallium-67, a case report

We describe here a case report of a patient with acute lymphocytic leukemia in whom hepatic gallium-67 (Ga-67) uptake was suppressed. The patient was hospitalized with increasing dyspnea. In Ga-67 scintigraphy, there was no hepatic uptake, although other physiological uptake was clearly observed. In addition, the scintigraphy showed increased accumulation in the right lung consistent with infection. We considered possible reasons for these findings. The patient had no history of chemotherapy or blood transfusion, and his iron metabolism was almost normal. He was not receiving any medication which might reduce hepatic blood flow. Blood chemistry suggested normal hepatic and renal function. The patient died from pneumonia 6 weeks later. The autopsy revealed extensive infiltration of the right lung with Bacillus cereus (B. cereus). Metabolic acidosis and/or iron utilization of B. cereus may induce both increased Ga-67 accumulation in the infected lesion and suppressed uptake in the liver, but these mechanisms could not explain normal physiological uptake in the other organs. This case warranted the further study of the hepatic Ga-67 uptake mechanism.

Very-long-period seismic signals and caldera formation at Miyake Island, Japan

Over a period of roughly 40 days, starting on 8 July 2000, a caldera structure 1.7 kilometers in diameter developed by means of gradual depression and expansion of the summit crater at Miyake Island, Japan. At the same time, very-long-period (VLP) seismic signals were observed once or twice a day. Source mechanism analyses of the VLP signals show that the moment tensor solutions are smooth step functions over a time scale of 50 seconds, with dominant volumetric change components. We developed a model to explain the caldera and the VLP signals, in which a vertical piston of solid materials in the conduit is intermittently sucked into the magma chamber by lateral magma outflow. This model offers potential for making quantitative estimations of the characteristic physical properties of magma systems.

[Contrast enhancement for sentinel lymph node imaging]

The paper proposes a new contrast enhancement method for sentinel lymph node imaging. The sentinel lymph node image acquired by a conventional gamma camera system has a wide dynamic range, so that the contrast of sentinel lymph nodes relatively decreases. The proposed method, which is named an annular background subtraction (ABS) method, first found the center of the distribution of activity. Then we calculated the mean value in each annular area centered at the injection point of radiopharmaceuticals with one pixel width. The original image was subtracted by the mean value at each annular area. The performance of the proposed method was confirmed by clinical data.

[Biodistribution of hypoxic marker, 99mTc-HL91 (4,9-diaza-3,3,10,10-tetramethyldodecan-2,11-dione dioxime)]

99mTc-HL91 (4,9-diaza-3,3,10,10-tetramethyldodecan-2,11-dione dioxime) was developed as a hypoxic marker. Athymic mice bearing human tumors were administered with 99mTc-HL91 to evaluate it from the clinical point view. The tumor was visualized clearly 4 hours after injection. The biodistribution study revealed that 99mTc-HL91 was accumulated in the liver (tissue-to-blood ratio (T/B) = 11.5) and kidney (2.25) with higher than in the tumor (1.01). Oxygen condition of the tumor and muscle was measured by using the probe. 99mTc-HL91 uptake of tumors with PO2 (tumor-to-muscle ratio) under 0.55 was higher than that with 0.55 or higher PO2. Oxygen condition of tumors with 1.0 or higher uptake (tumor-to-blood ratio) was lower than that with the lower uptake. Autoradiography of tumor sections indicated that 99mTc-HL91 was scarcely accumulated in the necrotic and viable areas while strong radioactivity was observed in the border zone (speculated to be hypoxic condition). Our experimental results suggest that the 99mTc-HL91 scintigraphy may be useful for evaluating oxygenation status of some tumors in non-abdominal region.

Breast-conserving therapy for ductal carcinoma in situ

This retrospective analysis evaluates the treatment results and prognostic factors of 114 patients with ductal carcinoma in situ (DCIS) undergoing breast conserving therapy (BCT) at Keio University Hospital Department of Radiology, between 1988 and 1997. A total of 132 patients with DCIS of the breast came to our hospital between 1988 and 1997, and 114 cases were suitable candidates for BCT. All of the patients were female and ranged in age from 26 to 81 years (median 46). Ninety-one patients were premenopausal, and 23 were postmenopausal. Median clinical tumor size was 2.0 cm (0-8.0 cm). Postoperatively 48 cases received 50 Gy/25 fractions of external irradiation to the whole breast via tangential ports. The follow-up period after treatment ranged from 11 to 162 months (median 46.7). The local relapse-free rate and overall survival rate of the 114 patients were 89.5% and 100%, respectively. Local failure and regional nodal failure occurred in 12 and 1 patient, respectively. Radiotherapy was a significant risk factor for local failure (p=0.05). No postmenopausal patients developed local failure, but the difference did not reach statistical significance (p=0.103). The 12 recurrent cases underwent additional surgery and all remain alive without recurrence, to date, i.e., at least 16 months. Breast-conserving surgery plus irradiation is appropriate treatment for DCIS patients.

Novel, potent, and selective phosphodiesterase 5 inhibitors: synthesis and biological activities of a series of 4-aryl-1-isoquinolinone derivatives

A novel class of potent and selective phosphodiesterase 5 (PDE5) inhibitors, 4-aryl-1-isoquinolinone derivatives, which have been designed by the comparison of the structure of cGMP and a previously reported 1-arylnaphthalene lignan, was disclosed. Among these compounds, methyl 2-(4-aminophenyl)-1,2-dihydro-1-oxo-7-(2-pyridinylmethoxy)-4-(3,4,5-trimethoxyphenyl)-3-isoquinoline carboxylate dihydrochloride (36a) exhibited potent PDE5 inhibitory activity (IC(50) = 1.0 nM) with high isozyme selectivities (IC(50) ratio: PDE1/PDE5 = 1300, PDE2/PDE5 > 10 000, PDE3/PDE5 > 10 000, PDE4/PDE5 = 4700, PDE6/PDE5 = 28). Compound 36a also showed the most potent relaxant effect on isolated rabbit corpus cavernosum (EC(30) = 7.9 nM). Compound 63 (T-1032), the sulfate form of 36a, was selected for further biological and pharmacological evaluation of erectile dysfunction.

Attenuation of live E. coli-induced acute lung injury by X-ray irradiation in guinea pigs

Irradiation is suspected to injure inflammatory cells, such as neutrophils and mononuclear phagocytes, cells known to contribute to the development of acute lung injury (ALI). This study examined whether preexposure to x-ray irradiation modifies ALI induced by E. coli injected intravenously in guinea pig. Thirty animals were divided into two control and two irradiated subgroups: the first control group received saline only (n = 8), and the second control group received E. coli, 2 x 10(9)/kg body weight, suspended in saline (n = 6), IV. The first irradiated group received a single 12-Gy dose + saline (n = 6), and the second irradiated group received a single 12-Gy dose + E. coli (n = 10). The lung wet-to-dry-weight ratio (W/D) and 125I-albumin lung tissue/plasma ratio (T/P) were measured as markers of lung injury. W/D was significantly higher in the control E. coli group than in the other groups. T/P in the control E. coli group was also increased compared with T/P measured in the other groups. In the control E. coli group, a marked increase in bronchoalveolar lavage (BAL) neutrophils was observed compared with the control saline group. However, no significant difference in BAL neutrophil counts was observed between the control and irradiated E. coli groups. In contrast, BAL macrophages were significantly reduced in the irradiated E. coli groups compared with the control E. coli group. These findings suggest that x-ray irradiation attenuates E. coli-induced ALI in guinea pigs, an effect explained, at least in part, by a reduction in the number of alveolar macrophages.

Lymph node metastasis from breast cancer diagnosed by F-18 FDG whole-body PET (case report)

We report a 48-year-old woman with lymph node (LN) metastases from breast cancer in whom diagnosis was difficult by conventional imaging methods but easy by F-18 fluorodeoxyglucose (FDG) PET. She was given a diagnosis of right breast cancer and then underwent modified radical mastectomy in December 1997. During routine CT and US studies in September 1998, a questionable LN measuring 1 cm in diameter was detected in the right supraclavicular region, but a definitive diagnosis of this LN was difficult by these tests. The patient underwent FDG PET test, which showed strong nodular activity (SUV= 7.1) in the right supraclavicular region, indicating a metastatic lesion. Moreover, an unexpected second metastatic LN lesion (SUV= 5.5) in the medial aspect of the right axillary was diagnosed by PET. The PET results were confirmed by pathological examination of the surgical specimens. FDG PET is a useful tool to detect small malignant lesions that are not easily diagnosed by conventional imaging techniques such as CT and US. It is expected that PET test will be feasible at many institutions.

Completely inverse images in dual-isotope SPECT with Tl-201 and I-123 MIBG in a patient with myocarditis

Dual-isotope myocardial SPECT in a female patient with idiopathic myocarditis showed completely inverse images in Tl-201 and I-123 MIBG SPECT. In the dual-isotope SPECT performed 13 days after her admission, Tl-201 SPECT images showed reduced accumulation in the apex and normal accumulation in the other regions, whereas the corresponding I-123 MIBG SPECT images showed normal findings in the apex and reduced uptake in the other regions. These rare discrepancies were due to the difference in photon attenuation of the two isotopes in the apex and denervated-but-viable myocardium in the basal region, which were suggested by the following findings of gated perfusion SPECT and echocardiography. Gated SPECT with Tc-99m tetrofosmin performed 23 days after admission revealed normal myocardial perfusion and normal wall motion. Iodine-123 MIBG SPECT findings reflected impaired wall motion in echocardiography performed on admission, which resembles a phenomenon called "memory image" in coronary artery disease. The present case indicated a pitfall in interpreting dual-isotope imaging.

Structure-Activity study of retinoid agonists bearing substituted dicarba-closo-dodecaborane. Relation between retinoidal activity and conformation of two aromatic nuclei

We have investigated the structure activity relationships of the potent retinoid agonist, 4-[4-(2-propyl-1,2-dicarba-closo-dodecaboran-l-yl)phenylamino]benzoic acid (BR403), which we have previously reported. Substitution of a methyl group on the aromatic nucleus or a methyl group on the nitrogen atom, or replacement of the amino group with ether, methylene, carboxyl or 1,1-ethylene greatly decreased the activity. The relatively planar conformation at the phenyl-N-phenyl moiety seems to play a critical role in the appearance of the biological activity.

Comparison of image reconstruction algorithms in myocardial perfusion scintigraphy

The purpose of this study was to compare the clinical utility of two image reconstruction algorithms in myocardial perfusion SPECT (single-photon emission computed tomography): filtered back-projection (FBP) and ordered subset expectation maximization (OSEM). A rest/stress one-day protocol with 99mTc-MIBI or tetrofosmin was performed on 102 consecutive patients who underwent coronary angiography. After SPECT data acquisition, images were reconstructed with FBP and OSEM algorithms. We assessed diagnostic performance (sensitivity, specificity and accuracy) in detecting coronary artery stenosis and evaluated regional tracer uptake with a 4-point scoring system. Although there were no significant differences in diagnostic performance between FBP and OSEM reconstruction, the OSEM method yielded higher uptake in the RCA area than the FBP method by reducing the count-loss artifact due to hepatic uptake of the tracers. In addition, regional uptake in the LCX area was significantly lower in the OSEM image than in the FBP image; this phenomenon was observed mainly in patients with coronary stenosis and/or infarction in the LCX territory. In conclusion, OSEM and FBP offered comparable diagnostic performance in stress myocardial perfusion SPECT. The OSEM method contributed to reduction of the count-loss artifact in inferior and posterior walls and to easy recognition of hypoperfusion in the LCX area.