[HLA class II alleles and leprosy (Hansen's disease) classified by WHO-MDT criteria]

Human leukocyte antigens (HLA) class II alleles were analyzed in Japanese leprosy patients to ascertain whether immunogenetic differences exist among the forms of leprosy in classification of World Health Organization-recommended multidrug therapy (WHO-MDT). The subjects were 86 unrelated Japanese leprosy patients, including 62 multibacillary leprosy (MBL), 24 paucibacillary leprosy (PBL). Controls were 114 unrelated healthy subjects. Genotyping of HLA class II alleles was performed by using the polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and PCR-restriction fragment length polymorphism (RFLP) methods. The frequencies of HLA-DRB1* 1501, * 1502 and DRB5* 0101,* 0102 and DQA1* 0102 and DQB1* 0602 were significantly increased in the whole patients (44.2%, 34.9%, 44.2%, 34.9%, 53.4% and 41.9%, respectively) as compared with the control subjects (14.0%, 21.1%, 14.0%, 21.1%, 27.2% and 13.2%, respectively). On the other hand, the frequencies of HLA-DRB1* 0405, * 0803, * 0901 and DQA1* 03 and DQB1* 0401 were significantly decreased in the whole patients (10.5%, 5.8%, 16.3%, 41.9% and 9.3%, respectively) as compared with the control subjects (29.8%, 17.5%, 30.7%, 78.1% and 29.8%, respectively). When MBL and PBL patients were compared, the frequencies of HLA-DRB1* 1501, DRB5* 0101 and DQB1* 0602 were significantly increased in the MBL patients (51.6%, 51.6% and 48.4%, respectively) as compared with the PBL patients (25.0%, respectively). Our results suggest that HLA-DRB1* 1501, DRB5* 0101 and DQB1* 0602 contribute to the susceptibility to the Japanese MBL.

Neuroradiological applications of a new system of stereoscopic biplane digital subtraction angiography

A stereoscopic biplane digital subtraction angiography (DSA) system was developed, capable of obtaining frontal and lateral projections simultaneously during a single injection of contrast medium. This new system combines the advantages of both biplane and stereoscopic single-plane DSA, and permits high-quality neuroangiography.

Hyperperfusion and hypermetabolism in brain radiation necrosis with epileptic activity

We report a case of high uptake of 11C-methionine (MET), 18F-FDG (FDG) and 201Tl-Cl (Tl) in brain radiation necrosis. Twenty-one years previously, the patient had undergone surgery and radiation therapy consisting of 60-Gy for ependymoma in the anterior horn of the right lateral ventricle. The clinical features consisting of frequent seizures of the left face and arm suddenly appeared 2 wk before admission. MRI depicted a Tl and T2-prolonged lesion in the right frontal lobe. Abnormally high uptake in this area demonstrated by MET-PET, FDG-PET, Tl-SPECT or HMPAO-SPECT suggested the presence of a recurrent tumor. A craniotomy was then performed and an intraoperative electrocorticogram showed continuous epileptic spikes in the lesion. The epileptic foci were resected and the histological features of the lesion were consistent with radiation necrosis. After surgery, the seizures disappeared and the postoperative examinations with MET-PET, FDG-PET, Tl-SPECT and HM-PAO-SPECT no longer showed abnormally high uptake. Hypermetabolism and hyperperfusion related to epileptic fits are therefore thought to result in high uptake of MET, FDG and Tl in radiation necrosis.

Anti-tumor-promoting activities of triterpenoids from ferns. I

To search for possible anti-tumor-promoters (cancer chemopreventive agents), we carried out primary screening of 23 triterpenoid hydrocarbons (1-23) isolated from ferns using an in vitro synergistic assay system. Of these triterpenoids, hop-17(21)-ene (2), neohop-13(18)-ene (3), neohop-12-ene (4), taraxerane (17), multiflor-9(11)-ene (18), multiflor-8-ene (19), glutin-5(10)-ene (21) and taraxastane (23) exhibited remarkable inhibitory effects on Epstein-Barr virus (EBV) activation induced by the tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA). Further, compounds 2 and 3 exhibited remarkable anti-tumorpromoting effects on mouse skin tumor promotion in an in vivo two-stage carcinogenesis test using 7,12-dimethybenz[a]anthracene (DMBA) as an initiator and TPA as a promoter.

The usefulness of FDG positron emission tomography for the detection of mediastinal lymph node metastases in patients with non-small cell lung cancer: a comparative study with X-ray computed tomography

We evaluated the usefulness of fluorine-18-fluoro-2-deoxy-d-glucose positron emission tomography (FDG PET) in the detection of mediastinal lymph node metastases in patients with non-small cell lung cancer and then compared the findings with the results of X-ray CT by region based on the histological diagnoses. We examined 29 patients with non-small cell lung cancer. One hundred and thirty-two mediastinal lymph nodes were surgically removed and the histological diagnoses were confirmed. FDG PET images, including 146 mediastinal regions, were visually analysed and the mediastinal lymph nodes were scored as positive when the FDG uptake was higher than that in the other mediastinal structures. On the X-ray CT scans, any mediastinal lymph nodes with a diameter of 10 mm or larger were scored as positive. All three examinations were successfully performed on 71 regions. For FDG PET, we found a sensitivity of 76%, a specificity of 98% and an accuracy of 93%. On the other hand, for X-ray CT a sensitivity of 65%, a specificity of 87% and an accuracy of 82% were observed. A significant difference was observed in respect of both specificity and accuracy (P<0.05). Based on the above findings, FDG PET is suggested to be superior to X-ray CT when used for the detection of mediastinal lymph node metastases in patients with non-small cell lung cancer.

[Evaluation of the usefulness of 111In-DTPA-IgG scintigraphy for the detection of focal inflammatory lesions]

We evaluated the usefulness of 111In-DTPA-IgG scintigraphy for the detection of focal inflammatory lesions. We examined 9 patients with focal inflammatory lesions that had been diagnosed based on the findings of various types of laboratory data and other imaging modalities. Scanning was performed at 6, 24, 36 and 48 hours after the administration of 80 MBq of 111In-DTPA-IgG. The sensitivity was 78%. A good diagnostic ability was observed by the scintigraphy findings at 24 hours. In conclusion, 111In-DTPA-IgG scintigraphy at 24 hours is thus considered to be useful for detecting focal inflammatory lesions.

Cerebellar vascular response to acetazolamide in crossed cerebellar diaschisis: a comparison of 99mTc-HMPAO single-photon emission tomography with 15O-H2O positron emission tomography

Various observations on the cerebellar vasoreactivity in crossed cerebellar diaschisis (CCD) have previously been reported. The purpose of this study is to clarify the difference between oxygen-15 H2O positron emission tomographic (PET) and technetium-99m hexamethylpropylene amine oxime (HMPAO) single-photon emission tomograph (SPET) findings in CCD and to evaluate the effect of the absolute values of the cerebellar blood flow as measured by 15O-H2O PET on the 99mTc-HMPAO SPET findings. The subjects comprised 15 patients with a supratentorial infarct and CCD. The cerebellar blood flow increased by about 40% at 5 and 20 min after acetazolamide i.v. on both the CCD and the non-CCD side, as measured by 15O-H2O PET. The percentage differences in cerebellar blood flow between the CCD and the non-CCD side were -22.3%+/-5.7% in the resting state, -19. 6%+/-6.4% at 5 min after acetazolamide i.v. and 21.5%+/-6.7% at 20 min after acetazolamide i.v., as measured by 15O-H2O PET, while they were -10.6%+/-5.5% in the resting state and -5.6%+/-5.1% at 5 min after acetazolamide i.v., as measured by 99mTc-HMPAO SPET. After Lassen's linearization correction, the latter two measurements were -16.2%+/-7.7% and -9.6%+/-8.9%, respectively. The effect of acetazolamide did not differ between the CCD and the non-CCD side in 15O-H2O PET, while a greater response on the CCD side was observed in 99mTc-HMPAO SPET, even after Lassen's linearization correction. It is concluded that acetazolamide HMPAO SPET may overestimate the cerebellar vascular response on the CCD side (or underestimate it on the non-CCD side).

[Endoscopic treatment of gastrointestinal cancers--indication and limitation]

Recently, endoscopic treatments have been applied for the curative treatment of early gastrointestinal cancers and for the palliative treatment of end-stage gastrointestinal cancers. As a curative treatment for early gastric cancers, the endoscopic Nd-YAG laser therapy was initially applied and a satisfactory results were obtained. However, the endoscopic mucosal resection (EMR) is evaluated as the reliable endoscopic treatment for early gastric cancers because curability can be histologically detected by resected specimen. EMR technique is also applied for early esophageal cancers and early flat or depressed colon cancers. EMR-L (EMR with the use of Ligating device) developed by us is mainly practiced in our department. By the use of EMR-L technique. Resectability has been improved compared with 2 channel EMR technique. As the palliation of end-stage gastrointestinal cancers endoscopy recanalization of malignant esophageal stenosis is very effective to improve the patient's QOL. The memorial metallic stent for esophageal stenosis is very useful to keep cavity for a long term after endoscopic recanalization. PEG (percutaneous endoscopic gastrostomy) is also very effective to reduce the symptoms of the patients with peritonitis carcinoma or ileus. In this paper, the present status of curative and palliative endoscopic treatment for gastrointestinal cancers was reported. In recent future, endoscopy will be more widely applied as a less invasive therapeutic procedure for gastrointestinal cancers.

Characterization of crosslinked collagens synthesized by mature articular chondrocytes cultured in alginate beads: comparison of two distinct matrix compartments

We have characterized immunohistochemically and biochemically the collagens accumulating in two compartments of the matrix formed by mature bovine articular chondrocytes in alginate beads. At all times of the 28-day culture period, more than 90% of the collagen molecules were recovered from the rim of cell-associated matrix (CM) which encapsulates individual chondrocytes and chondrocyte clusters. Both the total amount and concentration of collagens in this matrix compartment rose progressively with time. The ratio of collagen/proteoglycan remained relatively constant with time and was always five to seven times higher in the CM than in the interterritorial matrix compartment further removed from the cells. In the CM, collagen types II, IX and XI were present on Day 28 in relative proportions (95/l/3) similar to those in adult cartilage. A higher proportion of newly synthesized collagen type XI than types II or IX molecules did not become incorporated into the pericellular rim of matrix but accumulated in the further removed matrix. Although collagen type I was synthesized in small amounts by flattened cells at the surface of the beads, it did not become incorporated as heterotrimers or homotrimers in the matrix. Mature pyridinium crosslinks, principally pyridinoline, were detected as early as Day 7 of culture but became much more abundant between Days 15 and 28, especially in the CM which contained at all times more than 90% of the crosslinks formed. The codistribution of collagen types II, IX and XI and mature collagen-specific crosslinks support the contention that mature chondrocytes cultured in alginate matrix surround themselves with a protective shell whose composition is very similar to that which encapsulated the cells in vivo.

CT diagnosis of pleural dissemination without pleural effusion in primary lung cancer

We retrospectively reviewed the CT scans of 25 primary lung cancers with disseminated pleural nodules or minimal malignant pleural effusions that were not recognized preoperatively. Special attention was devoted to abutting interlobar fissures, thick major fissures, and disseminated nodules on the chest wall, the diaphragm, and in the interlobar fissures. Among 10 primary tumors abutting interlobar fissures, nine (90%) had at least one of these findings. Among 15 primary lung tumors which did not abut interlobar fissures, four (27%) had at least one of these findings. We conclude that CT is a useful modality for detecting the pleural dissemination of primary lung cancers when primary lung cancers abut interlobar fissures even if no pleural effusion is detectable on CT.

Type D dural carotid-cavernous fistula. Results of combined treatment with irradiation and particulate embolization

PURPOSE

To assess the efficacy of irradiation combined with particulate embolization for treating type D dural carotid-cavernous fistulas, supplied by the meningeal branches of both external (ECA) and internal carotid arteries.

MATERIAL AND METHODS

Nine patients were treated by particulate embolization via the ECA branches, followed by radiation therapy with doses of 30 Gy. One of these patients with recurrent symptoms received an additional 30 Gy one year after initial treatment, making a total dose of 60 Gy.

RESULTS

In all cases, symptoms were improved immediately after the particulate embolizations. In 8 cases, complete resolution of symptoms were obtained in 4-19 months and an average of 8 months after treatment. In one case, chemosis was markedly improved and persisted minimally 41 months later.

CONCLUSION

Particulate embolization is effective for immediate symptomatic improvement, and complete resolution of symptoms can usually be achieved by subsequent radiation therapy.

FDG-PET in infectious lesions: The detection and assessment of lesion activity

The usefulness of FDG-PET in the detection of infectious foci and the assessment of lesion activity was evaluated. The study covered 24 patients with 25 FDG-PET studies, including lesions of bacterial, tuberculous and fungal origins. The FDG uptake was determined by the lesion to muscle ratio (LMR) on the static images. The time activity curves (TACs) were classified into four patterns based on both the existence of an initial peak and a slope thereafter. A high FDG uptake was observed in 23 of 25 lesions (92%). Two lesions, in which no abnormal uptake was noted, included one in the healing stage and the other consisting of a cavity with a thin wall. The acute active lesions showed higher LMRs than the chronic active or healing lesions (mean +/- SD: 9.8 +/- 3.6, 3.6 +/- 1.8 and 4.3 +/- 1.7, respectively, p < 0.05), and they could be approximately distinguished by an LMR of 6. The patterns of the TACs in acute or chronic active lesions were either an increase without an initial peak or a plateau, while those in the healing lesions demonstrated predominantly an increase with an initial sharp peak. Our results indicated that FDG-PET is clinically useful in the detection of the infection of miscellaneous microorganisms as well as in the assessment of lesion activity.

Computed tomographic findings of Bellini duct carcinoma of the kidney

OBJECTIVE

To analyze CT findings of Bellini duct carcinoma, a rare variant of renal cell carcinoma.

MATERIALS AND METHODS

The CT findings of five cases of Bellini duct carcinoma were reviewed and the findings were recorded.

RESULTS

In all cases the affected kidneys maintained the normal outer contours. In four cases the renal masses protruded into the central sinuses. Contrast enhancement was minimal in four cases.

CONCLUSION

Bellini duct carcinoma should be suspected in cases with these CT findings.

Age-related change of technetium-99m-HMDP distribution in the skeleton

To understand age-related changes of whole-body and regional skeletal metabolism, it is important to investigate the mechanisms of age-related bone loss and to develop suitable treatments for it. Bone biopsies show metabolism of the particular site examined while biochemical markers for bone metabolism reflect total skeletal metabolism. Bone scintigraphy is a convenient and simple way to analyze whole-body and regional skeletal metabolism. We attempted to study and understand age-related changes in bone metabolism by quantifying the bone scan and correlating it with biochemical bone metabolic markers.

METHODS

The whole-body skeletal uptake (WBSU) and tracer distribution pattern were studied in men and women by bone scintigraphy using 99mTc-hydroxy-methane-diphosphonate (HMDP). Bone scans were performed using a standard protocol and quantified by setting regions of interest (ROIs) on selected regions. WBSU and the skeletal distribution pattern were compared with simultaneously obtained serum biochemical markers.

RESULTS

WBSU showed an increase with age in both sexes, but in women, uptake in the head and legs increased more relatively than in the thoracic region, while in men no such tendency was observed. Increase of WBSU and relative increase of uptakes in the head demonstrated a weak correlation with the serum levels of alkaline phosphatase and type 1 collagen metabolites.

CONCLUSION

These results show an age-related increase of skeletal turnover and sex-dependent regional skeletal metabolism. The age-related changes seen in bone scintigrams might be a sign of progressive bone loss, reflecting changes in local bone metabolism.

2-Deoxy-2-fluoro-D-glucose as a functional probe for NMR: the unique metabolism beyond its 6-phosphate

Epimeric conversion of 2-deoxy-2-fluoro-D-glucose (FDG) to its 2-epimer 2-deoxy-2-fluoro-D-mannose (FDM) proved by 19F NMR has been shown to reflect the brain activity. To examine the feasibility of FDG as a new NMR probe for in vivo functional monitoring, we studied here the fundamental NMR properties of metabolites, spectral assignments, and reliability of NMR quantification. Metabolites confirmed in brain besides FDM-6-phosphate were as follows: FDG-1-phosphate, FDG-1,6-bisphosphate, FDM-1-phosphate, FDM-1,6-bisphosphate, and FDG and FDM derivatives of nucleotide diphosphate. NMR quantification of these metabolites was evaluated in comparison with the method of 18F-labeled FDG. In the NMR functional study using FDG, where a high dose is inevitable, the dose dependence of uptake was investigated. FDG uptake in mouse brain was shown to be in the range of interpretation using the biochemical parameters of enzymes for glucose uptake as long as a dose of < 200 mg/kg was used.

A clinical evaluation of FDG-PET to assess the response in radiation therapy for bronchogenic carcinoma

The clinical usefulness of FDG-PET in the prediction and assessment of response to radiation therapy in patients with bronchogenic carcinoma was evaluated. Thirty patients with untreated bronchogenic carcinoma were included in the study. All patients received FDG-PET before the initiation of radiation therapy, while 20 also received it after completing the therapy. The tumor to muscle ratio (TMR) was used as an index of the FDG uptake. The tumor response to therapy was classified as either a partial response (PR, n = 21) or no change (NC, n = 9) according to changes in the tumor size. Prognosis was made 6 months after the initiation of therapy, and was classified as either relapse (n = 19) or non-relapse (n = 9). The FDG uptakes both before and after therapy were compared with tumor response and prognosis. A high FDG uptake was noted in all 30 lesions before therapy. No significant differences in the uptake before therapy was observed according to the histological types nor T factors (UICC). The lesions with a higher uptake (TMR more than 7) responded better to therapy than those with a lower uptake (p < 0.05). The decrease in the uptake after therapy tended to be more prominent in the PR group than in the NC group. The rate of relapse was higher in lesions with a higher uptake before therapy (TMR more than 10) than in those with a lower uptake. The relapse group also showed a higher uptake after therapy than the non-relapse group. In addition, all 6 lesions showing a higher uptake (TMR more than 5) after therapy eventually relapsed (p < 0.05). Two lesions demonstrating a lower uptake both before and after therapy did not relapse, although no tumor regression due to the therapy was observed. These results indicate that FDG-PET plays a complementary role in both predicting and assessing the therapeutic response and prognosis in patients with bronchogenic carcinoma.

Positron-labeled antioxidant 6-deoxy-6-[18F]fluoro-L-ascorbic acid: increased uptake in transient global ischemic rat brain

The in vivo uptake and distribution of 6-deoxy-6-[18F]fluoro-L-ascorbic acid (18F-DFA) were investigated in rat brains following postischemic reperfusion. Global cerebral ischemia was induced in male Wistar rats for 20 min by occlusion of four major arteries. Two time points were chosen for 18F-DFA injection to rats subjected to cerebral ischemia, at the start of recirculation and 5 days following recirculation. The rats were then killed at 2 h after tail-vein administration of 18F-DFA and tissue radioactivity concentration was determined. Increased uptake of radioactivity in particular brain regions, including the cerebral cortex, hypothalamus, and amygdala following injection of 18F-DFA, compared to the sham-operated control, was observed 5 days after reperfusion. Similar results were also obtained in in vitro experiments using brain slices. Abnormal in vivo accumulation of 45Ca, a marker of regional postischemic injury, was observed in these brain regions in tissue dissection experiments. Furthermore, metabolite analysis of nonradioactive DFA using 19F-NMR showed that DFA remained intact in the postischemic reperfusion brain. The present results indicate that 18F-DFA increasingly accumulates in damaged regions of postischemic reperfusion brain.

Characterization of the core promoter of the Na+/K(+)-ATPase alpha 1 subunit gene. Elements required for transcription by RNA polymerase II and RNA polymerase III in vitro

We have analyzed the core promoter element of the Na+/K(+)-ATPase alpha 1 subunit gene by means of an in vitro transcription system composed of a HeLa nuclear extract. 5'-deletion and 3'-deletion analyses revealed that this gene is specifically transcribed by RNA polymerase II in a manner that is dependent on the upstream regulatory region of the gene (-102 to -61), and that the 3' boundary of the minimal promoter element does not extend beyond +5. Analysis of linker-substitution mutations and point mutations revealed that the TATA-like sequence (-33 to -26) is required for upstream-sequence-dependent transcription whereas linker-substitution mutations and point mutations near +1 did not abolish transcription. The gene was found to be transcribed by RNA polymerase III when phosphocellulose column fractions were assayed. Deletion analysis mapped the minimal RNA-polymerase-III--specific promoter element from -49 to +17. The phosphocellulose 0.3-M-KCl fraction is absolutely required for transcription by RNA polymerase III, while the 0.85-M-KCl fraction represses aberrant transcription from incorrect initiation sites. Analysis of linker-substitution mutations indicated that the TATA-like sequence is required for RNA-polymerase-III--specific transcription. Although point mutations in the 5' half of the TATA-like sequence did not affect transcription, those in the 3' half shifted the transcription initiation site 3 bp upstream. The results suggest the the Na+/K(+)-ATPase alpha 1 subunit gene promoter contains a TATA-like sequence which can direct transcription by RNA polymerase III in vitro. The mechanism of alternative regulation of RNA polymerase II and RNA polymerase III is discussed.

Purification and refolding of recombinant human proMMP-7 (pro-matrilysin) expressed in Escherichia coli and its characterization

Human matrix metalloproteinase-7 (MMP-7 = matrilysin) was overproduced in Escherichia coli as a recombinant zymogen (31 kDa), the C-terminus of which bears artificial hexa-histidines. Most of the enzyme was isolated from the insoluble fraction of the cell lysate and purified by a single step using Ni-NTA resin after solubilization of the precipitates with 8 M urea solution. The resin-bound recombinant protein was refolded into a form that is activatable by p-amino-phenylmercuric acetate in an autocatalytic manner. The activated enzyme cleaved a synthetic peptide substrate at the reported site for MMP-7. Digestion of carboxymethylated transferrin (a natural substrate of MMP-7) by the recombinant proteinase generated fragments with the same peptide map as in the case of native purified MMP-7. The autocatalytic activation and enzyme reaction were entirely dependent on the presence of calcium and zinc ions. The enzyme activity to cleave carboxymethylated transferrin was inhibited by tissue inhibitors of metalloproteinases-1 and -2, MMP-specific inhibitors. The activity of the recombinant MMP-7 was also inhibited by a synthetic peptide derived from a part of the cysteine switch that maintains the zymogen in an inactive state. Thus, we report here a simple means of preparing a large quantity of recombinant proMMP-7 that can be used to study the activation mechanism and to screen synthetic inhibitors.

Changes in glucose transporter 2 and carbohydrate-metabolizing enzymes in the liver during cold preservation and warm ischemia

In order to examine glucose metabolism in liver grafts during cold preservation (24 and 48 hr), warm ischemia (60 and 120 min), a combination of the two and reperfusion, the amount of protein and mRNA of glucose transporter 2 and the activities of enzymes in glycolysis (glucokinase, phosphofructokinase, pyruvatekinase), gluconeogenesis (glucose 6-phosphatase, fructose 1,6-bisphosphatase), and the pentose phosphate pathway (glucose 6-phosphate dehydrogenase) were measured. It appeared that glucose transport, the pentose phosphate pathway, and gluconeogenesis were maintained during cold preservation and warm ischemia. The activity of glucokinase significantly decreased from the control value of 1.33 +/- 0.23 IU/g protein to 0.70 +/- 0.17 (24 hr, P<0.05) and 0.57 +/- 0.12 (48 hr, P<0.01) only during cold preservation. However, the activity of phosphofructokinase significantly decreased from the control value of 4.37 +/- 0.06 IU/g protein to 2.67 +/- 0.15 (60 min, P<0.0001) and 1.53 +/- 0.06 (120 min, P<0.0001) only during warm ischemia. This indicates that glycolysis deteriorates during both cold preservation and warm ischemia and demonstrates further that the balance between glycolysis and gluconeogenesis shifts to gluconeogenesis. Even when cold preservation was combined with warm ischemia, the activity of glucokinase decreased only during cold preservation and the activity of phosphofructokinase decreased only during warm ischemia. Furthermore, these changes were time-dependent. It is suggested that they can be used as a clock to measure the durations of cold preservation and warm ischemia separately and that the magnitude of an ischemic injury to a liver and a liver graft's viability can be indirectly estimated before transplantation.

Complete primary structure of the subunits of heterodimeric phospholipase A2 from Vipera a. zinnikeri venom

Molecular weight determination of dimeric phospholipase A2 from Vipera aspis zinnikeri venom (PLA2-I) was performed with electrospray ionization mass spectrometry (ESI-MS). PLA2-I consists of an acidic and a basic subunit (subunit A and B), which bind noncovalently and dissociate under highly acidic conditions. The protonated molecular ions of subunit A and B were measured to be 13,655.9 and 13,842.6, respectively. The complete amino acid sequence was also determined by Edman sequencing of the S-pyridylethylated derivative and its peptides derived from enzymatic digestion. Both subunit A and B consist of 122 amino acid residues and contain 7 disulfide bonds. The theoretical molecular mass calculated from the primary structure completely agree with the ESI-MS data. THe sequential homology between subunit A and B was 63.9%; however, subunit A lacks enzymatic and biological activities that are characteristic for phospholipase A2. Although the amino acid residues essential for calcium binding (Tyr28, Gly30, Gly32, and Asp49) and catalysis (Asp92) were preserved, replacement of functionally important residue (His48) for catalysis with a Gln was found in subunit A. In addition, substitution of acidic amino acid residues for basic ones and hydrophilic residues for hydrophobic ones were observed in subunit A. Presumably, these changes in the primary structure of subunit A resulted in the loss of enzymatic activity and an increase in the binding ability with subunit B.

Differences in the reduced 18F-Dopa uptakes of the caudate and the putamen in Parkinson's disease: correlations with the three main symptoms

It has been reported that the F-Dopa (FD) uptake in patients with idiopathic Parkinson's disease (PD) decreased significantly in the caudate and putamen when compared to controls. The FD uptake severely decreased in the putamen, while it was relatively spared in the caudate nucleus. We also previously reported that atypical parkinsonism with no or little tremor showed a homogeneously reduced FD uptake in both the caudate and the putamen. In this study we evaluated the caudate and the putaminal FD uptakes in relation to the three main symptoms in PD. The FD uptake was measured by PET with 6-L-[18F]fluorodopa in 17 patients with PD. The caudate and the putaminal FD uptake ratios to the cerebellum at 120 min were evaluated. The caudate and the putaminal FD uptake ratios in the patients with PD decreased as their clinical stages advanced. These decreases also correlated with the degree of rigidity and bradykinesia. However, such decreases did not correlate with the degree of tremor. The caudate-putamen index (CPI)(%), which was calculated by a formula based on the difference in the uptakes of the caudate and putamen divided by the caudate uptake, indicated 11.6 +/- 3.6, 16.5 +/- 5.5 and 18.3 +/- 4.1 in the group of no, mild and moderate tremor, respectively, and increased as the degree of tremor advanced. The CPI in the group of moderate tremor significantly increased from that in the group of no tremor (P < 0.04). However, the CPI did not correlate with the clinical stage, the degree of rigidity or the degree of bradykinesia. The FD/PET study therefore effectively demonstrated the severity of the clinical symptoms of rigidity and bradykinesia in patients with PD in correlation with a decrease in the FD uptakes in the caudate and the putamen, and it also demonstrated that the severity of tremor might have a different mechanism from that of such other symptoms as rigidity and bradykinesia.

Absence of lysosomal cleavage in the cytotoxicity mechanism of an immunoconjugate composed of anti-alpha-fetoprotein monoclonal antibody and vindesine analog

The effect of lysosomal enzyme inhibition on the cytotoxic activity of an immunoconjugate composed of anti-alpha-fetoprotein monoclonal antibody and vindesine analog (VDS) was studied in vitro using human tumor clonogenic assay (HTCA). Addition of the lysosome enzyme inhibitors, leupeptin and ammonium chloride, to the HTCA system had little influence on the cytotoxicity of this immunoconjugate. In separate experiments, no released VDS was detected by HPLC after incubation with the supernatant of rat liver homogenate without inhibitor. These results show that the immunoconjugate may bypass the lysosomal process and exert its activity as an intact or similar form.

Structure and expression of two seed-specific cDNA clones encoding stearoyl-acyl carrier protein desaturase from sesame, Sesamum indicum L

We have isolated two cDNA clones (CDES01) and 04) encoding stearoyl-acyl carrier protein desaturase (SACPD; EC 1.14.99.6) from immature sesame seeds, and have analyzed accumulation levels of the corresponding mRNAs at different stages and organs in sesame. Clone CDES01 contains an open reading frame coding for a 396-amino acid protein of 45 kDa. CDES04 encodes a partial sequence of 141-amino acids. Deduced amino acid sequences of both clones exhibit a high identity to those of other plant SACPD cDNAs. Northern blots probed with CDES01 and CDES04 indicate that both messages accumulate in a seed-specific manner with a peak at 21 days after anthesis. However, expression patterns also indicate that regulation between CDES01 and CDES04 are slightly different. The CDES01 message accumulates at a low level in young leaves in addition to seeds, whereas accumulation of the RNA transcript corresponding to CDES04 is restricted to seeds. This observation implies the presence of at least two isozymes of SACPD having overlapping but slightly distinct functions in sesame.

Inflammatory pseudotumors of the spleen: CT and MRI findings

OBJECTIVE

Our goal was to elucidate the CT and MRI findings of inflammatory pseudotumors of the spleen.

METHODS

The CT and MRI findings of three patients with inflammatory pseudotumors of the spleen were reviewed and compared with the pathologic findings.

RESULTS

On the early phase of CT, the masses were hypodense to the normal spleen, and on the delayed phase, they demonstrated delayed enhancement. On T1-weighted MR images, the masses were isointense to the normal spleen, and on T2-weighted images, the masses had heterogeneous low signal intensities. After administration of Gd-DTPA, the masses showed delayed enhancement.

CONCLUSION

Inflammatory pseudotumors of the spleen were characterized by low signal intensity on T2-weighted MR images and delayed enhancement after contrast material administration on CT and MRI. The fibrous stroma may contribute to these unusual findings.