Isolation and characterization of alpha-type HC3 and beta-type HC5 subunit genes of human proteasomes

Eukaryotic proteasomes from an evolutionarily conserved multi-gene family and are thought to have originated from a common ancestral gene and diverged into alpha-type and beta-type subgroups. To understand the molecular basis of the proteasome genes, we isolated and characterized two human proteasome genes econding the alpha-type HC3 and beta-type HC5 subunit. The functional genes for HC3 and HC5 are similar in being approximately 15 kb in length, but differ in having exon numbers of 9 and 6, respectively. Analyses of about 2.5 to 3.0 kb of the 5'-flanking regions of these two genes revealed the absence of TATA and CAAT promoter elements. However, two or three GC boxes were found. By analysis of the transcriptional regulatory activities in the 5'-flanking regions of the two genes, these GC boxes were found to function coordinately as promoters of the two genes. Interestingly, the HC3 gene possesses an additional silencer element in the 5'-upstream region near the first exon. This element is also able to repress the promoter activities of other genes, such as the HC5 and the type 1 glucose transporter genes, irrespective of whether it has a sense or antisense orientation, indicating that it acts as a general transcriptional silencer. The HC5 gene does not have this silence element, and its promoter activity is five to ten times that of HC3. These results show that the human proteasomal HC3 and HC5 genes differ not only in their genomic structures, such as their numbers of exons and their exon-intron organizations, but also in the mechanisms regulating their transcription, suggesting that they diverged at an early stage of evolution.

Isolation of rat TATA factor as an active 75kDa protein complex

A general transcription factor TFIID was purified from rat liver by a sequential column chromatography including organomercurial Sepharose and Sephacryl S-200 chromatographies, which were developed with an acidic buffer (pH5.5). Analyses by SDS-polyacrylamide gel electrophoresis, assay of eluants after renaturation, and immunoblotting showed that isolated TATA factor is an active 75kDa protein complex which contains 36kDa TATA-binding protein.

Myasthenia gravis associated with Addison's disease

Idiopathic Addison's disease developed in a 52-year-old female with a 15-year history of myasthenia gravis. The association of myasthenia gravis with other autoimmune diseases is well known, however an association with Addison's disease is rare. It was speculated that the development of Addison's disease in this patient might have been due to common immunological abnormalities underlying these two diseases. We report this case and briefly discuss the pathogenetic mechanism of this association.

Accelerated exon skipping of IRF-1 mRNA in human myelodysplasia/leukemia; a possible mechanism of tumor suppressor inactivation

The transcription factor IRF-1 has been shown to function as a tumor suppressor. Here we report that a significant proportion of the IRF-1 mRNA detected in normal human hematopoietic cells and cultured cell lines lacks exon 2 (containing the AUG initiation codon) and 3 as a result of exon skipping. Surprisingly, when we examined the bone marrow and peripheral mononuclear cells from patients with myelodysplastic syndrome (MDS) or leukemia secondary to MDS, we could still detect the exon-skipped form but little or none of the intact IRF-1 mRNA. This appears to be the result of accelerated exon skipping since we could find no mutations within the exons and splicing junctions from these patients. The exon-skipped form of IRF-1 lacking exons 2 and 3 displayed neither DNA binding nor tumor suppressive activities. Thus this accelerated exon skipping may cause the inactivation of IRF-1 and thereby contribute to the development of human hematopoietic malignancies.

Changes in muscle oxygenation during weight-lifting exercise

The quantitative analysis of haemoglobin oxygenation of contracting human muscle during weight-lifting exercise was studied noninvasively and directly using near-infrared spectroscopy. This method was developed as a three-wavelength method which confirmed the volume changes in oxygenated haemoglobin (oxy-Hb), deoxygenated haemoglobin (deoxy-Hb) and blood volume (total-Hb; Oxy-Hb+deoxy-Hb). Nine healthy adult men with various levels of training experience took part in the study. Ten repetition maximum (10 RM) one-arm curl exercise was performed by all the subjects. Results showed that at the beginning of the 10-RM exercise, rapid increases of deoxy-Hb and decreases of oxy-Hb were observed. In addition, total-Hb gradually increased during exercise. These results corresponded to the condition of arm blood flow experimentally restricted using a tourniquet in contact with the shoulder joint, and they showed the restriction of venous blood flow and an anoxic state occurring in the dynamically contracted muscle. In three sets of lifting exercise with short rest periods, these tendencies were accelerated in each set, while total-Hb volume did not return to the resting state after the third set for more than 90 s. These results would suggest that a training regimen emphasizing a moderately high load and a high number of repetitions, and a serial set with short rest periods such as usually performed by body builders, caused a relatively long-term anoxic state in the muscle.

Influence of efonidipine hydrochloride, calcium antagonist on the epithelium of prostates in spontaneously hypertensive rats

The hypertensive effect on the development of the prostatic abnormality in spontaneously hypertensive rats (SHRs) was examined using Efonidipine hydrochloride, a calcium antagonist. The control SHRs were given a high sodium and potassium diet (SP-diet) alone, and the treated SHRs were given a SP-diet with 0.15% Efonidipine hydrochloride from 8 to 28 weeks of age. The systolic blood pressure (SBP) in the control SHRs increased with age, while the elevation of SBP was significantly prevented in the treated SHRs. Light-microscopically, the prostatic lesion was observed both in the control and treated SHRs. The glandular lumen was narrowed with papillary protrusions, and the epithelium was composed of tall columnar epithelial cells. However, hypertension-induced complications in kidneys and hearts were not observed in the treated SHRs. These results suggested that the prostatic abnormality of SHRs might not be the consequent lesions upon hypertension.

Clival chordoma in early childhood without bone involvement

Intracranial chordomas are rare in childhood. Only 15 cases have been reported in children less than 6 years old. Bone destruction and calcification have been stated to be characteristics of this tumor. We present the case of a 5-year-old boy with clival chordoma without bone involvement.

Glucocorticoid regulation of calcitonin receptor in mouse osteoclast-like multinucleated cells

Abundant multinucleated cells (MNCs) are formed in cocultures of mouse osteoblastic cells and marrow cells in the presence of 1 alpha, 25-dihydroxyvitamin D3 [1 alpha, 25(OH)2D3], and these cells have the properties of osteoclasts (OCs). In this study using the mammalian OCs, we tried to clarify the role of glucocorticoids (GCs) in calcitonin receptors (CTR) and CT-responsive cAMP production in OCs. Dexamethasone (DEX) dose and time dependently enhanced the specific binding of [125I]salmon calcitonin (sCT). When the MNCs were preincubated with DEX for 24 h, the effect was evident at 10(-9) M and the maximum effect was obtained at 10(-7) M. The effect developed over 12-48 h at doses of 10(-9) and 10(-6) M DEX. The numbers of CTR-positive mononuclear cells and MNCs were not altered by the DEX treatment. Prednisolone and triamcinolone reproduced the DEX effect, but 17 beta-estradiol, progesterone, testosterone, aldosterone, and 1 alpha, 25(OH)2D3 did not. RU486, a GC receptor antagonist, attenuated the effect of DEX to enhance the specific binding of [125I]sCT. From a Scatchard plot analysis, DEX enhanced CTR number (212 +/- 64%) with a minimal change in the affinity to sCT. Autoradiographic studies using [125I]sCT showed that DEX enhanced the density of the grains on the tartrate-resistant acid phosphatase (TRAP)-positive MNCs and mononuclear cells, but not on other types of cells. DEX preincubation also enhanced sCT-stimulated but not prostaglandin E2- or forskolin-stimulated cAMP production.(ABSTRACT TRUNCATED AT 250 WORDS)

A randomized cross-over study of high-dose metoclopramide plus dexamethasone versus granisetron plus dexamethasone in patients receiving chemotherapy with high-dose cisplatin

We carried out a randomized, single-blind, cross-over trial to compare the antiemetic effect, for both acute and delayed emesis, of granisetron plus dexamethasone (GRN+Dx) with that of high-dose metoclopramide plus dexamethasone (HDMP+Dx). Fifty-four patients with primary or metastatic lung cancer, given single-dose cisplatin (> 80 mg/m2) chemotherapy more than twice, were enrolled in this study. They were treated with both HDMP+Dx and GRN+Dx in two consecutive chemotherapy courses. On day 1, patients experienced a mean of 2.5 (SD = 4.3) and 0.1 (SD = 0.4) episodes of vomiting in the HDMP+Dx and the GRN+Dx groups, respectively (P = 0.0008). Complete response rate on day 1 was 45 and 90% in the HDMP+Dx and the GRN+Dx groups, respectively (P = 0.0001). Patients treated with GRN+Dx had a tendency to suffer more episodes of vomiting than the HDMP+Dx group on days 2-5, but it was not statistically significant. Twenty-four patients (57%) preferred the GRN+Dx treatment and 14 patients (33%), HDMP+Dx. In the HDMP+Dx group, nine patients (21%) had an extrapyramidal reaction, and 5 patients (12%) had constipation that lasted for at least two days. In contrast, no patients had extrapyramidal reactions, and 18 patients (43%) had constipation in the GRN+Dx group (P < 0.01). GRN+Dx was more effective than HDMP+Dx only in preventing the acute emesis induced by cisplatin. An effective treatment for delayed emesis is still needed.

Sequence analyses and inter-species comparisons of three novel human proteasomal subunits, HsN3, HsC7-I and HsC10-II, confine potential proteolytic active-site residues

Proteasomes play a major role in non-lysosomal pathways of protein turnover mediated by distinct multiple proteolytic activities. Identification of their active-site residues is important for elucidating their catalytic mechanisms. Here we report the nucleotide sequences of three human proteasomal subunits, HsN3, HsC7-I and HsC10-II, coding for proteins with 264, 201 and 205 amino acid residues with calculated molecular weights of 29,192, 22,836 and 22,931, respectively. Sequence comparison showed that all three proteins belong to the beta-type superfamily and that they are the human counterparts of subunits reported to participate in the peptidyl-glutamyl-peptide hydrolyzing, chymotrypsin-like and trypsin-like activity of this complex. Alignments of the putative catalytically active subunits of various species revealed several family-specifically conserved serinyl residues within highly conserved amino acid stretches. Based on localization and hydrophobicity, the roles of these amino acid residues as active site and substrate binding site candidates are discussed.

Glycine 85 of the trp-repressor of E. coli is important in forming the hydrophobic tryptophan binding pocket: experimental and computational approaches

Experimental and computational analyses were performed on the corepressor (L-tryptophan) binding site of the trp-repressor of Escherichia coli to investigate the ligand-protein interactions. Gly85, one of the residues forming the hydrophobic pocket of the binding site, was systematically replaced with Ala, Val, Leu and Trp by cassette mutagenesis. Biochemical characterization showed that all these mutations caused significant decreases in tryptophan binding activity. Free energy perturbation calculations were performed for the mutants and were consistent with the experimental results. The lack of a side chain at position 85 was concluded to be essential for binding the corepressor; the structure of the binding pocket was suggested to be tight in the vicinity of Gly85.

Risk factors for the development of post-lab acute coronary occlusion following successful percutaneous transluminal angioplasty

Acute coronary occlusion can occur following percutaneous transluminal coronary angioplasty (PTCA) upon return to the coronary care unit (CCU), and is sometimes life-threatening. To identify high-risk patients for acute occlusion following PTCA, we analyzed 11 patients with post-lab acute occlusion. All of the patients had some evidence of intimal tear or dissection at the site of dilatation. During the study period, 1343 patients (1998 lesions) with angina pectoris underwent PTCA. Of these, 331 vessels (17%) had some degree of intimal tear or dissection at the site of dilatation. From these 331, 50 patients (50 vessels) without evidence of acute occlusion were randomly selected to serve as the control group. Patients in the acute occlusion group had more extensive dissection (p < 0.05) and less water balance (drip-infused water-urine, ml) during angioplasty (p < 0.1) than those in the control group. Furthermore, a significantly higher percentage of patients in the acute occlusion group complained of chest discomfort upon arrival at the CCU (72% vs 8%, p < 0.0001). These variables may be useful in identifying high-risk patients for post-lab acute occlusion, particularly in the presence of an intimal tear or dissection at the target site.

Phase I and pharmacokinetic study of paclitaxel by 24-hour intravenous infusion

Paclitaxel, a new antitubular agent, appears to be one of the most promising single agents for the chemotherapy of various solid tumors. The primary objectives of this phase I study of paclitaxel using 24-h continuous intravenous infusions were to determine the maximum tolerated dose of paclitaxel administered by this schedule to Japanese patients with solid tumors and to evaluate the pharmacokinetics of paclitaxel. Eighteen patients received one of five doses of paclitaxel, 49.5, 75, 105, 135 or 180 mg/m2. Premedication with diphenhydramine, dexamethasone, and ranitidine was used to prevent acute hypersensitivity reactions. Pharmacokinetic data were obtained from all 18 patients. Dose-limiting toxicities observed at 180 mg/m2 consisted of grade 4 granulocytopenia associated with grade 3 infection. No severe HSRs or cardiac toxicity were detected. Reversible toxicities observed included liver dysfunction, alopecia, peripheral neuropathy and myalgias. Pharmacokinetic studies performed using high-performance liquid chromatography demonstrated that plasma concentrations of paclitaxel increased during the 24-h infusion and declined immediately upon cessation of the infusion with a half life of 13.1-24.6 h (75-180 mg/m2). Less than 10% of paclitaxel was excreted in the urine within 72 h. The peak plasma concentrations and the areas under the concentration-versus-time curves increased linearly with the dose administered. Antitumor activity was observed in one patient with pulmonary metastasis from pharyngeal cancer. Based on these studies a phase II trial dose of 135 mg/m2 administered over 24 h was chosen.

Preliminary evaluation of the new tumor marker, CYFRA 21-1, in lung cancer patients

Serum samples from 137 lung cancer patients were examined by RIA to evaluate the clinical efficacy of the new tumor marker, CYFRA 21-1, which could identify the soluble fragment of cytokeratin 19. The cut-off value was determined to be 2.2 ng/ml according to the receiver operating characteristic curve. The sensitivity, specificity and accuracy of the RIA for CYFRA 21-1 were 57.7, 91.9 and 64.9%, respectively. The serum concentration of CYFRA 21-1 and the sensitivity of the assay increased as the disease progressed. Histologically, the sensitivity was highest for squamous cell carcinomas (SQ) (76.5%) in comparison with adenocarcinomas (47.8%) and small cell lung cancers (42.1%) (P < 0.01, P < 0.05, respectively). The sensitivities for SQ were 60.0, 83.3, 80.0 and 100% at stages I, II, III and IV, respectively. When compared with CEA (45.3%) and squamous cell carcinoma related antigen (SCC) (22.6%) in all lung carcinomas, CYFRA 21-1 showed the highest sensitivity (57.7%), (P < 0.05, P < 0.01, respectively). In SQ, the sensitivity of the CYFRA 21-1 RIA was significantly higher than that of the assay for SCC (47.1%) (P < 0.05). In patients with adenocarcinomas, the sensitivity of the CYFRA 21-1 assay was almost the same as that for CEA (49.3%). In a combination of CYFRA 21-1 and CEA for non-small cell lung cancers (NSCLC), the sensitivity and accuracy increased to 75.4 and 78.1%, respectively, although the specificity decreased to 86.5%. It is concluded that CYFRA 21-1 could replace SCC, a less satisfactory tumor marker, for SQ of the lung. The potentiality of the combination of CYFRA 21-1 and CEA for NSCLC should be estimated using larger samples in the near future.

A randomized prospective study of imipenem-cilastatin with or without amikacin as an empirical antibiotic treatment for febrile neutropenic patients

To evaluate the effect of adding amikacin (AMK) to imipenem-cilastatin (IPM/CS), we conducted a randomized controlled trial in patients who experienced neutropenia (< 1,000/mm3) and fever (> 38 degrees C) induced by cancer chemotherapy. There were 70 patients who entered the trial; 34 and 36 patients received IPM/CS plus AMK (arm A) and IPM/CS (arm B), respectively. There was no significant difference in patient characteristics between the two groups. Among 67 evaluable patients, 29 of 32 (91%) and 25 of 35 (71%) responded to the antibiotics therapy in arm A and B, respectively, with EORTC criteria (p < .047). Median days of antibiotics administration and of febrile episode over 38 degrees C were not statistically significantly different between arm A and B. There was no patient with severe side effects, such as seizure, and 17 patients (30%) experienced emesis in both groups. These data suggest IPM/CS plus AMK is therapeutically superior to IPM/CS alone in patients with neutropenic fever induced by cancer chemotherapy.

Angiographic follow-up of patients after transluminal coronary extraction atherectomy

The transluminal coronary extraction-endarterectomy catheter (TEC) consists of a torquing tube with a distal, conical rotating blade. We successfully treated 26 patients (27 lesions) using this catheter with adjunctive balloon angioplasty. Twenty-five patients (26 lesions) had serial angiography before, 1 day after, and 3 months after the procedure. All 17 patients without restenosis 3 months after the procedure had angiography at 6 months. Restenosis, defined as > 50% diameter stenosis, was noted in nine lesions at 3 months (early restenosis) and in five lesions at 6 months (late restenosis). Between vessels with and without early restenosis, the percentage of diameter stenosis seen 1 day after the procedure and the luminal diameter were significantly different (38% +/- 14% vs 22% +/- 12%, respectively, p < 0.01; 2.3 vs 2.9 mm, p < 0.01, respectively). However, between vessels with and without late restenosis, these variables were not significantly different. The overall restenosis rate was 54% (native vessels 50%; grafts 80%). This observational study suggests that very early diameter narrowing seen 1 day after the procedure has greater contribution to early restenosis than to late restenosis after successful TEC atherectomy with adjunctive balloon angioplasty.

Concurrent cisplatin-etoposide chemotherapy plus thoracic radiotherapy for limited-stage small cell lung cancer. Japanese Lung Cancer Chemotherapy Group in Japanese Clinical Oncology Group

A recent approach in the treatment of limited-stage small cell lung cancer (LDSCLC) has involved a combined modality of chemotherapy and chest irradiation. In using the modality, the study of scheduling methods for combining chemotherapy and radiotherapy should lead to other trials of combined modalities against LDSCLC since it is the most basic issue to be evaluated. We have thus conducted a multicenter phase II trial of concurrent cisplatin-etoposide (PVP) chemotherapy and radiotherapy for LDSCLC to determine the effects of the concurrent administration of a PVP regimen and chest irradiation on response rate, relapse, survival and treatment toxicity. The chemotherapy regimen consisted of a four-week cycle: cisplatin (80 mg/m2, given intravenously on day 1) and etoposide (100 mg/m2, given intravenously on days 1-3). This cycle was given four to six times within six months. Chest irradiation to the primary tumors at both the hili and the mediastinum was administered in standard fractions on days 2-12 in the first cycle of chemotherapy and on days 29-47 in the second cycle, with a total dose of 40-50 Gy. Prophylactic cranial irradiation was performed among complete remission (CR) or good partial remission (PR) patients after completion of the concurrent therapy. A total of 66 patients were entered into the trial and 59 were evaluated. The concurrent therapy induced an overall response rate of 94.9% in 59 patients: 24 patients, 40.7% CR, 32 patients, 54.2% PR. The median response duration was 8.7 months, and the median survival time for all eligible patients was 14.8 months. The percentage of patients with two-year survival periods was 20. A local relapse within the irradiated area was seen in only 22% of relapse patients. Brain metastases occurred in 24% of patients. Four of 32 patients treated with prophylactic cranial irradiation had brain metastases. Toxic effects, chiefly grades 3 and 4 leukopenia, as established by the World Health Organization, were detected in all treated patients. Other toxicities, including radiation-induced esophagitis and pneumonitis, were deemed almost acceptable. We concluded concurrent treatment of a PVP regimen with chest irradiation to be a feasible and beneficial therapy with an efficacy compatible to that of other published reports. The outcome of this protocol warrants further investigation to determine the optimal type of schedule for concurrent chemoradiotherapy against LDSCLC.

Diffuse spasm of a free gastroepiploic artery graft during percutaneous balloon angioplasty

Percutaneous transluminal balloon dilation of an 8-month-old free graft of the gastroepiploic artery was followed by diffuse and profound graft spasm. Because free arterial grafts are more prone to spasm, suitable precautions, such as administration of calcium channel antagonists, should be taken before attempting any interventions on these vessels.

Protective effects of the nucleic acid components on CCL4-induced liver injury in rats

In our previous studies, uracil was identified as the active principle from Trionyx carapax. The protective effects of other nucleic acid components, and of xanthine are further investigated.

CPT-11: population pharmacokinetic model and estimation of pharmacokinetics using the Bayesian method in patients with lung cancer

In this study, we aimed to develop a population pharmacokinetic model for CPT-11 and to use the Bayesian method to estimate CPT-11 pharmacokinetic parameters in each of 43 patients who received combined therapy consisting of CPT-11 and etoposide. The group was divided into first and second data sets of 30 and 13 patients, respectively. We developed a population pharmacokinetic model of CPT-11 based on the first data set. The individual pharmacokinetic parameters [area under the concentration curve (AUC) and clearance (CL)] were subsequently estimated by using the Bayesian method on the second data set. Plasma CPT-11 concentrations were measured by high-performance liquid chromatography, and compartmental pharmacokinetic models were fitted by the Bayesian method. The population pharmacokinetic model was developed by using the nonlinear mixed effect model. We selected the volume of the central compartment (Vc), CL, and distribution rate constants (K12, K21) as population pharmacokinetic parameters. The population mean values (CV%) of Vc, CL, K12, and K21 were, respectively, 31.8 (15.7%) liter/m2, 14.1 (27.8%) liter/h/m2, 1.1 (8.4%)/h, and 0.41 (30.3%)/h. Residual intraindividual variability was 22.9%. The optimal sampling regime for estimation of the AUC and CL in using the Bayesian method was the two time points of 1 and 8 h post infusion. The mean predictive error, the mean absolute predictive error, and the root mean squared error were -3.3, 9.4, 3.2% (AUC) and 6.3, 10.0, 3.5% (CL), respectively. We concluded that the AUC and CL of CPT-11 could be estimated from plasma concentrations at two times by using the Bayesian method.

Seroepidemiological study of toxoplasmosis in two different geographical areas in Nepal

A total of 302 serum samples collected from Chitawan (159) and Mustang (143) districts of Nepal were included in this study. Anti-toxoplasma antibody was detected using micro-latex agglutination (MLA) and ELISA methods. An overall positive rate was found to be 57.9%. The positive rate in Chitawan was significantly higher (64.1%) (less than 1,000 m altitude) compared to that in Mustang (51.0%) (more than 3,000 m altitude) (p < 0.05). Females in Chitawan showed significantly higher positive rate (71.2%) compared to males (56.9%) (p < 0.05). On the contrary, though insignificantly, males showed higher positive rate (57.9%) compared to that of females (43.3%) in Mustang. Almost equal positive rate was observed among males in both study area. Females in Chitawan showed significantly higher (71.2%) positive rate compared to their counterparts in Mustang (43.3%) (p < 0.001). A slight increase in positive rate with age was observed in Chitawan while in Mustang a decreasing trend was noticed. Ethnically though statistically not significant, Indo-Aryans showed a higher positive rate (69.2%) compared to the positive rate shown by Tibeto-Burmans (63.1%) in Chitawan while the reverse was true in Mustang (Tibeto-Burmans: 53.8% and Indo-Aryans: 38.4%). Interestingly, 2.9% and 1.3% of MLA positive samples showed toxoplasma IgM antibody. None of the IgM positive samples were positive for toxoplasmic antigens.

cDNA cloning and interferon gamma down-regulation of proteasomal subunits X and Y

Proteasomes are the proteolytic complex responsible for major histocompatibility complex (MHC) class I-restricted antigen presentation. Interferon gamma treatment increases expression MHC-encoded LMP2 and LMP7 subunits of the proteasome and decreases expression of two proteasome subunits, named X and Y, which alters the proteolytic specificity of proteasomes. Molecular cloning of complementary DNAs encoding X and Y showed that their proteins are proteasomal subunits with high amino acid similarity to LMP7 and LMP2, respectively. Thus, interferon gamma may induce subunit replacements of X and Y by LMP7 and LMP2, respectively, producing proteasomes perhaps more appropriate for the immunological processing of endogenous antigens.