[Gene expression of human eukaryotic initiation factor-4E for protein synthesis and study of its recognition mechanism of mRNA cap structure]

Being stimulated by the insights from model studies that (i) the intimate combination of hydrogen-bonding pairing and aromatic stacking interactions is important for the specific binding of guanine base by peptide and (ii) the pi-pi stacking force of Trp is significantly strengthened by the guanine N7-methylation (m7G), this research project was started, because (a) the mRNA cap structure is characterized by the existence of m7G and (b) an eukaryotic initiation factor-4E (eIF-4E), a protein which specifically recognizes the mRNA cap structure and opens the protein biosynthesis, contains 8 Trp residues irrespective of its relatively low molecular weight of about 25 kDa. In order to prepare the sufficient amount of sample for carrying out the analysis of the recognition mechanism of mRNA cap structure by eIF-4E at the atomic level, firstly, the expression of human eIF-4E gene in Escherichia coli was attempted. An artificial gene encoding for human eIF-4E was chemically synthesized and succeeded in the expression with two different forms, i.e., as a fusion protein with human growth hormone and a direct expression of soluble protein. The isolation of eIF-4E and its purification procedure using the m7GTP affinity chromatography were accomplished. It was shown by spectroscopic methods that the recombinant eIF-4E exhibits essentially the same tertiary structure as the native one and the binding ability with mRNA cap analog was identical with each other. In order to analyze the functional amino acid residues which are essential for specific recognition of mRNA cap structure, next a series of eIF-4E mutants were prepared by the site-directed mutagenesis, and His37, His200, Trp102 and Glu103 were suggested to be important for binding of mRNA cap structure, as judged from comparison of the binding abilities of respective mutants with a m7GTP affinity column. Since the crystals of recombinant eIF-4E-m7GTP complex suitable for X-ray crystallography are now in preparation, the detailed interaction mode between them will be opened in near future.

[Determinations of microproteinuria in early diabetic nephropathy]

Microalbuminuria, transferrin and IgG were determined in the urine of diabetic patients with normal renal function. Microalbuminuria was assayed by the immunoturbidity method, transferrin by the latex agglutination method and IgG by the ELISA method using biotin labelled IgG.HRP labelled protein G. The correlation between microalbuminuria and urinary transferrin concentrations was high (r = 0.902). However, a low titer of transferrinuria was observed, (25.5%) among the patients with microalbuminuria; a wider distribution of transferrinuria was noted than microalbuminuria. Determination of transferrinuria did not appear to be superior to the determination of microalbuminuria in early diabetic nephropathy. The urinary IgG levels assayed by ELISA using biotin labelled IgG.HRP labelled protein G method were distributed from zero to 5 mg/g Cr in the patients with normoalbuminuria. The reference intervals of the urinary IgG concentration should be settled below 5 mg/g Cr. In the patients with microalbuminuria, the concentration of urinary IgG showed a wide variation and no correlation between concentrations of microalbuminuria and urinary IgG was noted (r = 0.02). Determination of urinary IgG is not useful as an early diagnostic procedure for diabetic nephropathy.

[Effect of a coplanar PCB on lipid metabolism: the remarkable difference between rats and guinea pigs]

We studied the effect of 3, 4, 5, 3', 4'-pentachlorobiphenyl (PenCB) on lipid metabolism by determining the level of triacylglycerol and total cholesterol in rats and guinea pigs. Male Wistar rats and male Hartley guinea pigs received PenCB in corn oil one at a dose of 25 mg/kg i.p. and 0.5 mg/kg i.p., respectively. Pair-fed control group of both species were treated with the vehicle and given the amount of chow matched with that taken by the PenCB-treated animals. Free-fed control group was treated with vehicle and was given the chow ad libitum. The plasma was collected on the day 5 after the treatment and the liver was removed. The plasma triacylglycerol level in guinea pigs treated with PenCB was significantly higher than those in free- and pair-fed controls, whereas no significant difference was observed in PenCB-treated rats from both control groups. The plasma cholesterol level was also higher in PenCB-treated guinea pigs than in the two control groups, though the level in rats was significantly lower than the corresponding control values. The hepatic triacylglycerol and cholesterol levels were increased significantly in both species by the PenCB treatment. Although lipid metabolism was disordered in both animals by treatment with PenCB, the responsiveness was remarkably different between guinea pigs and rats. These differences could be associated with species difference in susceptibility toward toxic chlorinated aromatic hydrocarbons.

Translocation (9;22)(q22;q12). A recurrent chromosome abnormality in extraskeletal myxoid chondrosarcoma

Cytogenetic analysis of a case of extraskeletal myxoid chondrosarcoma revealed a reciprocal translocation between 9q and 22q in almost all metaphases analyzed. Structural rearrangements involving 9q and 22q have been reported previously in three cases of extraskeletal myxoid chondrosarcoma. The breakpoints on chromosomes 9 and 22 in the present case were in regions 9q22-q31 and 22q11-q12.2, respectively. The same breakpoints were present in all three previously reported cases. Thus, this recently identified rearrangement of 9q and 22q may serve as a critical cytogenetic parameter for the diagnosis and classification of extraskeletal myxoid chondrosarcoma, as well as being a primary chromosomal event in the course of development of this rare malignancy.

Bronchoalveolar mast cells in summer-type hypersensitivity pneumonitis: increase in numbers and ultrastructural evidence of degranulation

To investigate the role of mast cells in the development of summer-type hypersensitivity pneumonitis (SHP), which is the most common type of hypersensitivity pneumonitis in Japan, bronchoalveolar lavage fluid (BALF) cells from 13 patients with this disease was studied by light and electron microscopy. The proportion and number of BALF mast cells recovered from SHP patients were significantly greater than those from patients with sarcoidosis and from control subjects. The BALF mast cells from the SHP patients showed various ultrastructural changes such as the transformation of granules, cytoplasmic vacuolation, and an increase of lipid droplets. These findings appeared to reflect activation and degranulation of bronchoalveolar mast cells, suggesting that mast cells play a role as inflammatory cells in the development of SHP.

Structure of the osteopontin gene and its promoter

We cloned the hOPN gene and its 5' upstream region, and analyzed its exon-intron structure and potential regulatory sequences of the promoter region in comparison with those of mouse and porcine homologues. The hOPN gene consists of 7 exons that are similar to those of the mouse gene, although the hOPN gene is longer than the mouse homologue. This difference is attributable to an insertion of about 1750 bp immediately before exon 4 in the hOPN gene. A region of approximately 285 bp immediately upstream of the hOPN transcription initiation site was highly conserved and contained a number of potential cis regulatory consensus sequences. CAT analysis using SCC-3 cells demonstrated that nucleotides at positions -439 to -270, -124 to -80, and -55 to -39 contained cis-acting enhancing elements, in which the -124 to -80 element was much more active than the others. Deletion of the sequences between -474 and -270 localized the cis elements to the sequence at position -439 to -410, whereas the deletion between -124 to -80 localized it to -124 to -115, and -94 to -80 (data not shown). Gel shift analysis using synthesized double-stranded oligonucleotides corresponding to the 30 bp at position -439 to -410 (data not shown), and 10 and 15 bp regions at positions -124 to -115 and -94 to -80, respectively, as probes revealed that each probe formed one or two bands complexed with a nuclear protein prepared from SCC-3 cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Neurogenic tumors of the mediastinum originated from the vagus nerve

Thirty-nine patients with neurogenic tumors observed between 1974 to 1992 were reviewed. There were 32 patients with neurilemoma, one with neurofibroma, five with ganglioneuroma, and one with malignant neurilemoma. Two cases of neurilemoma originated from the vagus nerve, which is very rare. Surgical resection is recommended, not only to confirm the nature of the lesion, but also to prevent further growth and compression on adjacent structures. For benign encapsulated neurogenic tumors, resection is curative.

Expression of wild-type and mutated rabbit osteopontin in Escherichia coli, and their effects on adhesion and migration of P388D1 cells

Recombinant wild-type rabbit osteopontin (rOP) and the protein with an aspartate-to-glutamate transposition induced by a point mutation in the rabbit OP cDNA within the Gly-Arg-Gly-Asp-Ser (GRGDS) sequence were expressed in Escherichia coli and purified to homogeneity. P388D1 cells bound rOP in a saturable manner. rOP induced adhesion and haptotaxis of P388D1 cells, whereas mutated rabbit OP (rOPmut) did not. Anti-rOP IgG F(ab')2 and synthetic GRGDS peptide inhibited rOP-mediated adhesion and haptotaxis of P388D1 cells. Fibronectin (FN)-mediated adhesion of P388D1 cells was markedly inhibited in the presence of fluid-phase rOP. Adhesion of P388D1 cells to rOP was significantly inhibited by anti-[alpha-subunits of VLA4 (alpha 4) and VLA5 (alpha 5)] monoclonal antibodies (mAbs), but not by anti-[alpha-subunit of vitronectin (VN) receptor (alpha V) or Mac-1 (alpha M)] mAb. Adhesion of P388D1 cells to FN and VN was significantly inhibited by anti-alpha V mAb but not anti-alpha 4, -alpha 5 or -alpha M mAb. Haptotaxis of P388D1 cells to rOP was significantly inhibited by anti-alpha V mAb, but not by anti-alpha 4, -alpha 5 and alpha M mAbs, whereas that to FN showed no inhibition with all three mAbs. Haptotaxis of P388D1 cells to VN was significantly inhibited by anti-alpha 5 and -alpha V mAbs but not by anti-alpha 4 and -alpha M mAbs. Similar features of inhibition of adhesion and haptotaxis of P388D1 cells to human OP were observed by mAbs. rOP had no chemotactic effect on P388D1 cells. Significant polymorphonuclear leucocyte migration was observed 3-12 h after intradermal injection of rOP into rabbits.

Clinical features of sarcoidosis in relation to HLA distribution and HLA-DRB3 genotyping by PCR-RFLP

BACKGROUND

Susceptibility to the development of sarcoidosis has been demonstrated to be associated with HLA-DR5, -DR6, and -DR8 encoded by the DRB1 gene. However, involvement of the DRB3 (HLA-DR52) gene in the development of sarcoidosis remains unclear.

METHODS

HLA-DRB3 genotyping was performed using the PCR-RFLP method and the clinical features of the patients with and without the DR3, 5, 6, 8 group antigens were compared.

RESULTS

HLA-DRB3 genotyping indicated an association between DRB3*0101 and sarcoidosis. The DR8 haplotype lacking the DRB3 gene has been found to be increased significantly in sarcoidosis, suggesting that the HLA-DRB3 gene is not a primary determinant of predisposition to sarcoidosis. The association of DRB3*0101 with sarcoidosis is attributable to linkage disequilibrium with DR5- and DR6-associated alleles. There were significant decreases in the DR3, 5, 6, 8 group (DR5, DR6, or DR8) antigen frequencies in patients with retinal perivasculitis, high intraocular pressure (or secondary glaucoma), and optic nerve and/or macular lesion. Correlations were observed among the DR3, 5, 6, 8 group antigens, early onset sarcoidosis and disease with fewer intraocular lesions.

CONCLUSION

This established a molecular basis for some of the clinical heterogeneity observed in sarcoidosis.

The role of cyclic AMP in the lipopolysaccharide-induced suppression of thymidine kinase activity in macrophage

We observed that lipopolysaccharide (LPS, 1 micrograms/ml) can suppress [3H]thymidine incorporation into acid-insoluble fraction in a mouse macrophage cell line J774 (over 70% at 6 h) without affecting the uptake of [3H]thymidine or DNA polymerase activity. Paralleling this suppression, a decrease in the thymidine kinase (TK) activity, but not of thymidine monophosphate (TMP) kinase and thymidine diphosphate (TDP) kinase, was observed. LPS dose-dependently increased intracellular cAMP levels to about 3.5-times basal at 6 h, proportionally to the decrease of the TK activity. Elevation of intracellular cAMP by several reagents also decreased TK activity. Apparently LPS treatment elevates cAMP concentration by decreasing the low Km cAMP phosphodiesterase activity (58% at 6 h). The time course of cAMP-dependent protein kinase (PK-A) activity during the first 6 h after LPS treatment correlated with that of cAMP concentration. Treatment with a PK-A inhibitor restored about 63% of LPS-induced reduction of TK activity at 6 h. At longer times, however, there was a discrepancy between the change of cAMP concentration or PK-A activity and the reduction of TK activity. Therefore, protein kinase activation caused by the accumulation of intracellular cAMP probably triggers some mechanism responsible for the reduction of the TK activity.

Systemic magnesium deficiency disclosed by magnesium loading test in patients with essential hypertension

The present study was designed to determine whether magnesium (Mg) deficiency is present in patients with essential hypertension. We measured the retention of an intravenously administered Mg load (0.2 mmol/kg MgSO4 over 4 h), and serum and erythrocyte Mg concentrations in 17 inpatients with essential hypertension and in 15 normotensive controls. There was no significant difference between the two groups in erythrocyte Mg concentration (normotensives vs., hypertensives: 2.0 +/- 0.5 vs. 2.1 +/- 0.4 mmol/l cells), serum Mg concentration (normotensives vs. hypertensive: 2.1 +/- 0.2 vs. 2.1 +/- 0.2 mg/dl), or in urinary Mg excretion (normotensives vs. hypertensives: 65.8 +/- 25.5 vs. 73.7 +/- 26.7 mg/day). However, Mg retention was significantly higher in hypertensives than in normotensives (normotensives vs. hypertensives: 31.8 +/- 12.1 vs. 41.9 +/- 13.3%). These results suggest that a systemic Mg deficiency, which is undectectable by serum or erythrocyte Mg determination, may exist in patients with essential hypertension.

Contrast-enhanced MR imaging of intrahepatic cholangiocarcinoma: pathologic correlation study

The authors describe the enhanced magnetic resonance (MR) imaging appearance of intrahepatic cholangiocarcinoma. The MR images of eight patients with intrahepatic cholangiocarcinoma who underwent MR examination within 3 weeks before partial hepatectomy were retrospectively studied. The MR images, including a dynamic study, were compared directly with pathologic and histologic findings. The peripheral region of the medullary subtype of cholangiocarcinoma, with many tumor cells, showed greater enhancement relative to liver parenchyma in the early phase. The peripheral region of the scirrhous subtype, with fewer tumor cells showed less enhancement in the early phase. In one patient, the thin rim of the medullary tumor showed less enhancement in the late phase, and this rim corresponded to the peripheral region of the medullary tumor with many tumor cells. The central region of tumors with a large amount of fibrous tissue showed prolonged enhancement in the late and delayed phases. The thin rim of liver parenchyma around the tumor showed less enhancement in the early phase and greater enhancement in the late phase; this rim corresponded to congestive liver parenchyma with dilated sinusoids. Intrahepatic cholangiocarcinoma shows various enhancement patterns, which depend on both the histologic subtype and the degree and distribution of fibrosis within the tumor.

Overexpression of Pseudomonas putida catechol 2,3-dioxygenase with high specific activity by genetically engineered Escherichia coli

The cloned xylE gene encoding catechol 2,3-dioxygenase (metapyrocatechase) from TOL plasmid in Pseudomonas putida mt-2 has been expressed in Escherichia coli W3110 to a level of approximately 15% of the total soluble protein. Of the total iron in the crude extract, 45% was on the enzyme. The crystallized enzyme from E. coli had higher iron content (3.7 mol/mol enzyme) and specific activity (536 U/mg) than the enzyme from P. putida mt-2. However, no differences were observed in physicochemical, protein-chemical, and kinetic properties between the two enzymes. The enzyme was a homotetramer, and no changes were observed in the values of M(r) (136,000 +/- 5,000) and Stokes radius (4.26 nm) in the concentration range from 0.36 nM to 2.8 microM, indicating that the native enzyme neither dissociated into subunits nor polymerized in this range. The catalytic center activity and the Km values for catechol and dioxygen were 278 s-1, 1.87 and 7.45 microM, respectively, at pH 7.5 and 25 degrees C. The enzyme showed a broad substrate specificity. Among substrates, 4-methylcatechol and 4-chlorocatechol showed specificity constants (approximately 200 microM-1.s-1) higher than that for catechol. Acetone and phenol derivatives competitively inhibited the activity against catechol. The relationship between specific activity and iron content was not linear, suggesting some conformational changes in the partially iron-depleted enzyme.

Lymph node cancer of the mediastinal or hilar region with an unknown primary site

We herein report three cases of lymph node cancer of the mediastinal or hilar region, in which the primary sites could not be determined in spite of performing various systemic examinations. Two cases revealed a large cell anaplastic carcinoma in the mediastinal lymph node, while the other demonstrated a small cell carcinoma in the hilar lymph node. However, based on radiographic and pathological examinations, the primary sites could not be found in either the head and neck, lung, or abdominal organs. All cases underwent surgical resections for lymph node cancer, while two patients also received adjuvant therapy. Two patients experienced recurrence soon after treatment. Despite the rarity of this disease, lymph node cancer must always be kept in mind when an enlargement of either the mediastinal or hilar lymph node is detected in patients with an unknown primary site, and a poor prognosis is generally expected.

Conserved delta-activity in reverse enantiomeric opioid peptide

A reverse enantiomeric peptide has a reversed amino acid sequence with enantiomeric amino acid residues compared with its parent peptide. In most cases the random change of amino acid sequence or chirality might be expected to bring about significant changes in peptide activity. However, the reverse enantiomeric peptides of Leu-enkephalin and Tyr-D-Ala-Gly-Phe-D-Leu (DADLE) have shown affinity for the opioid delta-receptor, but not for mu- or kappa-receptors. This suggests that delta-opioid receptor recognition occurs primarily through interaction with the peptide side chains, since the native opioid peptide and its reverse enantiomer are able to have similar side-chain conformation.

A new applicator utilizing distributed electrodes for hyperthermia: a theoretical approach

We propose a new type of applicator for hyperthermia namely a Distributed Electrodes Applicator. Many electrodes are fixed on boli below which the patient is placed. A set of RF with optimized amplitudes and phases is supplied to the electrodes so as to minimize the ratio of SAR (specific absorption rate) in the fat layers to that in the central region of the patient. SAR patterns in a heated material were calculated using two-dimensional finite element method, and the results showed that the proposed applicator can heat the deep portions of the patient without excessive heating of the fat layers.

Secondary amyloidosis associated with Castleman's disease

A rare case of secondary amyloidosis associated with Castleman's disease is reported. A 53-year-old woman was referred for investigation of proteinuria. Biopsy specimens from kidney and gastric mucosa revealed numerous amyloid deposits, defined as AA amyloidosis by immunohistological staining. Castleman's disease was found in the abdomen as the primary disease for the amyloidosis. Although the urinary protein was somewhat reduced and the inflammatory findings were improved after removal of the lymphoma, renal insufficiency progressed and hemodialysis was begun.

Soluble expression of a synthetic gene for human translation initiation factor 4E in Escherichia coli

In order to obtain the active form of recombinant human initiation factor (eIF) 4E effectively, an artificial synthetic gene was cloned into an expression vector (pMAL-p2) and the soluble expression was attempted in Escherichia coli under the control of a tac promoter. Two expression systems were finally constructed as a fusion protein with maltose-binding protein, which contain a recognition sequence for the site specific protease alpha-thrombin and factor Xa, respectively. Most of the fusion protein was induced as a soluble form. The soluble human eIF-4E digested from the fusion protein showed binding specificity for the m7GTP affinity column.

[Case report: rheumatoid arthritis complicated by chronic myelogenous leukemia treated with interferon]

A fifty-six-year old man complained of arthralgia and swelling of both feet, morning stiffness in both hands and finger joints in March 1987, and was treated with non-steroidal anti-inflammatory agents at another hospital. He has been treated for chronic myelogenous leukemia (CML) since May 1990. He was admitted to our hospital in March 1991 because of worsening of his multiple arthralgias, and a diagnosis of rheumatoid arthritis (RA) (Stage I, Class 2) was made on the basis of gait disturbance, arthralgia persisting for more than 6 weeks, the presence of subcutaneous nodules and X-ray findings. CML was confirmed by peripheral blood and bone marrow findings and the presence of the Philadelphia chromosome and bcr gene rearrangement. High fever and dyspnea developed suddenly 3 days after administration of interferon in May 1991. In addition to pneumonia, a leucostasis was suspected and he was treated with high dose steroids and antibiotics. After improvement, the steroids were tapered and he was discharged from hospital in July 1991.

[A report to 2 cases where Stenotrophomonas maltophilia with a mucoid phenotype was isolated from the sputum]

Mucoid Stenotrophomonas maltophilia was isolated from the sputum of 2 women. Case 1 which we reported recently was primary pneumonia caused by S. maltophilia. However, in Case 2, mucoid S. maltophilia represented part of the transient flora. Interestingly, colonization of mucoid Pseudomonas aeruginosa on respiratory tract occurred in both cases after mucoid S. maltophilia was isolated from their sputum.

The relationship between the immunodetection of transforming growth factor-beta in lung adenocarcinoma and longer survival rates

We immunohistochemically examined the expression of transforming growth factor-beta (TGF-beta) on tissue specimens from primary 124 human lung adenocarcinoma, using a polyclonal antibody. The overall mean immunoreactivity of TGF-beta was 25.7 +/- 22.9, therefore we separated patients into two groups according to their mean immunoreactivity. There were 59 (48%) with a high TGF-beta and 65 (52%) with a low TGF-beta. No correlation was observed between the expression of TGF-beta and clinicopathological factors except for degree of differentiation. The 5-year survival rates of patients with high and low TGF-beta were 71% and 37%, respectively (P < 0.05). A multivariate analysis using the Cox life table regression model showed TGF-beta to be a significantly independent factor. We thus concluded, based on our findings, that the expression of TGF-beta was found to be related to a better prognosis. Therefore, estimating the negative cell proliferation activity induced by TGF-beta on immunohistochemical technique is considered to be useful for determining the patients' prognosis in cases of lung adenocarcinoma.

Enantioselective biotransformation of 1-isopropylnaphthalene in rabbits

1-Isopropylnaphthalene (1) was administered orally to rabbits and the following eight metabolites, 2-(1-naphthyl)-2-propanol (7), 2-(1-naphthyl)-1-propanol (8: R/S = 83:17), 2-(1-naphthyl)-1,2-propanediol (9:R/S = 40:60), 4-isopropyl-1,2-naphthoquinone (10), 4-isopropyl-1-naphthol (11), 4-isopropyl-2-naphthol (12), 5-isopropyl-2-naphthol (13), and 2-(1-naphthyl)propanoic acid (14') as its methyl ester (14: R/S = 52:48), were isolated from urine. Among them, three metabolites (8, 9, and 14), possessing an asymmetric carbon atom in the molecule, were formed enantioselectively and five metabolites (7, 10, 11, 12, and 13) were formed regioselectively. The presumed metabolic pathways of 1-isopropylnaphthalene (1) in rabbits leading to these metabolites are discussed.

[Preoperative prediction of the amount of surgical correction by using Botulinum A type toxin for the treatment of paralytic esotropia]

The aim of this study was to obtain the correct choice of initial surgical procedure and to predict the amount of surgical correction by using the maximum reduction rate of eye position after Botulinum A-type toxin injection for the treatment of acquired neurogenic paralytic strabismus. The subjects were 30 with sixth nerve palsy and 33 with non-paralytic esotopia with no previous surgery. The results were that if the maximum reduction rate of eye position after the first injection of 1.25 U was less than 68%, the modified Jensen procedure with recession of medial rectus muscle was necessary to achieve 100% recovery. However, if it was more than 100%, then recession-resection of the horizontal rectus muscles alone produced successful ocular alignment. Based on our data of 100 cases of sixth nerve palsy that showed spontaneous recovery, we conclude that surgical treatment should be planned, if the maximum percentage reduction of preoperative eye position after Botulinum A-type toxin treatment is under 68% (reflecting the inability of the medial rectus muscle to contract and the lengthening of the lateral rectus muscle), and if the patient has no spontaneous improvement at all within 12 weeks after onset.