Relationship between axonal regeneration and vascularity in tubulation--an experimental study in rats

This study investigated the effect of vascularity in a nerve conduit on peripheral nerve regeneration. The effect of three different types of tube (empty, blood vessel-containing and ligated vessel-containing) was compared using a rat sciatic nerve preparation with a 10-mm gap. Nerve regeneration through the vessel-containing tube was more efficient than in the other tubes 6 and 12 weeks after tubulation surgery, but there were no statistically significant differences among the three types of tube after 24 weeks. Electrophysiological, histological and microangiographic studies showed that vessels which were preinserted in the nerve conduit accelerated axonal regeneration through rapid capillary formation in the tube.

Strain variation in susceptibility to the development of monoclonal antibody 5-1-6-induced proteinuria in rats

Susceptibility to the development of MoAb 5-1-6-induced proteinuria was investigated in four different rat strains, i.e. Brown-Norway (BN), Lewis (LEW), Sprague-Dawley (SD) and Wistar. An intravenous injection of 5 mg of MoAb 5-1-6 to female 7-week-old rats of a given strain induced massive proteinuria in BN, LEW and Wistar rats. However, SD rats developed almost no proteinuria. A similar tendency was observed in the second experiment, in which the injected dose of MoAb was adjusted according to the body weight of each rat (3 mg/100 g body weight). Immunofluorescence (IF) and immunoelectron microscopy (IEM) revealed no differences between the binding patterns of the MoAbs to normal rat kidneys derived from each strain. Quantitative study using 125I-labelled MoAb showed that there was no significant difference in the amount of antibody bound to the kidney 1 h and 5 days after injection between two rat strains, LEW and SD. Localization of 5-1-6 in vivo and its kinetics were investigated. In IF a linear-like pattern along capillary walls was observed 2 h after injection in both LEW and SD strains. This linear-like pattern was shifted to a granular pattern in proteinuric LEW rats 6 days after injection, whereas it remained linear-like in non-proteinuric SD rats. IEM confirmed this difference in the localization of injected MoAb 6 days after injection to LEW and SD rats also at the ultrastructural level. We conclude that there is a clear-cut strain difference in the development of proteinuria induced by MoAb 5-1-6. SD rats were less susceptible to MoAb-induced glomerular injury than BN, LEW and Wistar rats. Although the exact reason for strain variation in susceptibility to MoAb-induced proteinuria remains to be clarified, the movement of bound MoAb, presumably together with corresponding antigenic molecule along the glomerular epithelial cell surface followed by endocytosis into the epithelial cell, seems to be closely related to the induction of proteinuria.

Arteriovenous malformation of the bronchial artery showing endobronchial protrusion

The bronchoscopic findings of arteriovenous malformation of the bronchial artery are compared with findings on angiography and pathology. A non-pulsatile protrusion with engorged vessels on its glossy and uneven surface was seen at the distal portion of the right anterior segmental bronchus. A bronchial angiogram demonstrated that the protrusion corresponded to the hypervascular area of convoluted vessels. Histologically, a glossy, uneven surface and engorged vessels represented normal mucosa overlaying an extramuscular tortuous artery and proliferation of submucosal tiny vessels, respectively. These bronchoscopic findings were important clues for diagnosis.

Lipopolysaccharide treatment in vivo induces tissue expression of GTP cyclohydrolase I mRNA

A significant induction of GTP cyclohydrolase I (GTPCH) mRNA was observed in lung, heart and kidney of rats treated with lipopolysaccharide (LPS; 10 mg/kg i.v.). GTPCH mRNA levels in liver were high even in untreated rats, and remained elevated after LPS treatment. Parallel induction of nitric oxide synthase (NOS) mRNA was observed in these tissues of LPS-treated rats. Our results demonstrate induction of GTPCH mRNA after LPS treatment in vivo and provide molecular evidence for the increased GTPCH activity which may up-regulate NOS activity in vivo.

Thermosensitivity of green fluorescent protein fluorescence utilized to reveal novel nuclear-like compartments in a mutant nucleoporin NSP1

Tagging proteins with the green fluorescent protein (GFP) from Aequorea victoria is a good means of analyzing protein localization in living cells. Nevertheless, GFP and a chimeric protein, GFP-nucleoplasmin, expressed in Saccharomyces cerevisiae were less fluorescent at high culture temperatures. Proteins synthesized at a low temperature retained their fluorescence despite a shift to a higher temperature. Hence, when a temperature-sensitive nsp1 mutant expressing GFP-nucleoplasmin was cultured at 23 degrees C and then shifted to 35 degrees C, we were able to exclusively monitor the localization of the protein synthesized prior to the temperature shift. This protein accumulated in novel nuclear-like compartments devoid of DNA.

Cloning of the creatinine amidohydrolase gene from Pseudomonas sp. PS-7

The gene encoding creatinine amidohydrolase (EC 3.5.2.10) was isolated from Pseudomonas sp. PS-7. The primary structure of creatinine amidohydrolase deduced from the nucleotide sequence showed that the protein is composed of 259 amino acids and has a molecular weight of 28,437. The enzymatic property of creatinine amidohydrolase produced by recombinant E. coli was identical with those by Pseudomonas sp. PS-7.

T-cell receptor V alpha and V beta gene use by infiltrating T cells in labial glands of patients with Sjögren's syndrome

Sjögren's syndrome is an autoimmune disease affecting the exocrine glands; it is thought to result from T-cell-mediated damage. In the labial glands of 20 patients with Sjögren's syndrome, infiltrating T cells were immunohistochemically characterized, and T-cell receptor (TCR) gene expression was examined with a method based on polymerase chain reaction. Most of these lymphocytes expressed CD3, CD4, CD45RO, and TCR alpha beta, whereas less than 5% of them expressed CD25 and CD69. The TCR V alpha and V beta genes expressed in peripheral blood mononuclear cells were diverse, whereas the TCR V alpha and V beta repertoires in the labial glands were more restricted but were still heterogeneous. The predominantly used V alpha and V beta families in the labial glands, when compared with those in peripheral blood mononuclear cells, were found to vary in individual patients and also to differ from patient to patient. Thus the T-cell population in the labial glands was polyclonal but showed a more restricted pattern than that seen in peripheral blood mononuclear cells.

Biodegradable plate fixation of rabbit femoral shaft osteotomies. A comparative study

Femoral shaft transverse osteotomies in 58 rabbits were fixed with ultrahigh strength poly-L-lactic acid plates made by a drawing technique. Similar osteotomies in another 35 rabbits were fixed using stainless steel plates. The union rate, the mechanical strength of the united bones, bone mineral content and density in the area beneath the plate using dual energy x-ray absorptiometry, and the cortical thickness beneath and opposite the plate using a digitizer was compared between the poly-L-lactic acid and stainless steel groups after postoperative periods of 8, 25, and 40 weeks. The poly-L-lactic acid and stainless steel groups showed union rates of 67% (39 of 58) and 80% (28 of 35) without displacement, respectively. In the poly-L-lactic acid group, plate failure occurred in 14% (8 of 58). The mechanical strength of the specimen was restored to a level equal to that on the untreated side by 25 weeks, and cortical thickness and bone mineral content and density were maintained almost normal for 40 weeks in the poly-L-lactic acid group. The stainless steel group showed significantly lower mechanical strength and led to osteopenia because of stress shielding after 25 weeks.

Pituitary adenylate cyclase-activating polypeptide stimulates the synthesis of dopamine in cultured bovine adrenal chromaffin cells

The effect of pituitary adenylate cyclase-activating polypeptide1-38 (PACAP1-38) on the synthesis of dopamine in cultured bovine adrenal chromaffin cells was examined. PACAP1-38 stimulated [14C]dopamine synthesis from [14C]tyrosine, in a concentration-dependent manner, causing maximal stimulation at 10(-7)M. This stimulatory action of PACAP1-38 was not significantly inhibited by staurosporine (an inhibitor of protein kinase C) or in the cells in which protein kinase C was down-regulated by prolonged exposure to TPA (an activator of protein kinase C), whereas it was partially attenuated in Ca(2+)-free medium. PACAP1-38 increased the formation of [3H] inositol phosphates, [Ca2+]i, 45Ca2+ uptake and cAMP level. The peptide also stimulated the phosphorylation of tyrosine hydroxylase, the enzyme catalyzing the rate-limiting step in dopamine synthesis. Dopamine synthesis and tyrosine hydroxylase phosphorylation stimulated by the maximal effective concentration of dibutyryl cAMP or high K+, which activates Ca2+ uptake, were further enhanced by PACAP1-38. These results indicated that PACAP1-38 may stimulate the activities of cAMP- and calcium-dependent protein kinases in cultured bovine adrenal chromaffin cells, resulting in increase in the synthesis of dopamine probably by stimulation of phosphorylation of tyrosine hydroxylase.

Physiological significance of plasma sulfoconjugated dopamine: experimental and clinical studies

Sulfoconjugated catecholamines have been regarded simply as metabolites of free catecholamines. However, a conjugated form of the catecholamine, dopamine has recently attracted much attention because it is present at high levels in the plasma of humans and experimental animals. We carried out experimental and clinical studies to determine the physiological significance of this large amount of dopamine conjugate in the plasma. Clinical studies showed that the plasma level of dopamine sulfate decreased significantly during the acute phase of heart failure, whereas that of free dopamine increased. Moreover, the plasma level of conjugated dopamine in patients with essential hypertension was higher than that in control subjects, and being highest in patients with renal hypertension. In experimental studies, we examined the activity for deconjugating DA sulfate in homogenates of organs from dogs. The kidney and liver exhibited the highest activities, and in the heart, the activity was higher in the atrium than the ventricle. We also examined the effect of dopamine sulfate on isolated perfused rat heart. Dopamine sulfate was found to be converted to free dopamine, which was responsible for the positive inotropic action, in atrial tissue. Moreover, deconjugation of DA sulfate to the free form was accelerated by a high work lord on the heart. From these results, we conclude that the formation of dopamine sulfate plays a role in regulating the level of plasma free dopamine and that plasma dopamine sulfate may be a storage or reserve form of dopamine. Free (or active) dopamine may be formed through a deconjugation reaction when necessary.

Genetic diagnosis of cytoplasmic male sterile cybrid plants of rice

Twelve Japanese rice cultivars were converted to CMS by asymmetric protoplast fusion with MTC-5A, the cytoplasm of which was derived from an indica rice, Chinsurah Boro II. With the exception of the cybrids that had a nucleus from Hoshiyutaka, most of these cybrid plants were sterile. The unique sequence downstream from the mitochondrial atp6 of MTC-5A was specifically amplified in the sterile cybrid plants by PCR. All progenies of the cybrid plants carrying this unique sequence were sterile. On the other hand, in some of the sterile cybrid plants in which the unique sequence was not amplified by PCR, fertility was recovered in their progenies. Somaclonal mutation may have caused sterility in these cybrids. Only the cybrid plants that had the unique sequence detected by PCR were CMS. Thus, the CMS plants can be selected rapidly and easily by PCR, at an early stage of plant regeneration. Soon after transplanting the regenerated plants to a green house, fertile cybrids and sterile cybrids produced by somaclonal mutation can be removed. These findings also show that the unique region downstream from atp6 is tightly linked with the CMS phenotype.

Influence of disodium (1-hydroxythylidene) diphosphonate on bone ingrowth into porous, titanium fiber-mesh implants

The influence of disodium (1-hydroxythylidene) diphosphonate on the bonding between bone and porous, titanium fiber-mesh implants was studied. Rectangular, porous, titanium fiber-mesh implant (15 x 10 x 2.4 mm) were implanted into the tibial bone of mature male rabbits. The rabbits were divided into six groups. Disodium diphosphonate was administered daily by subcutaneous injection to groups 1-5. Groups 1-4 received doses of 5.0, 2.5, 1.0, and 0.1 mg per kilogram of body weight per day for 8 weeks, respectively. Group 5 received a dose of 5 mg per kilogram of body weight per day for 4 weeks. Group 6 (control group) was given saline injections. At 8 weeks after implantation, the rabbits were killed. The tibiae containing the implants were dissected out and subjected to detachment tests. The failure load, when an implant became detached from the bone or when the bone itself broke, was measured. The interface of the bone and implant was investigated by Giemsa surface staining and contact microradiography. Giemsa surface staining and contact microradiography showed that porous implant bonding to bone tissue was inhibited by a high dose of disodium diphosphonate in groups 1, 2, and 5. Soft tissue was observed at the interface. In groups 3, 4, and 6, bone tissue ingrowth was observed at the interface between the porous implant and bone tissue. Growth of bone into the porous fiber-mesh implant of a cementless prosthesis is possible if a low dose of diphosphonate below 1.0 mg per kilogram of body weight is given subcutaneously.

Scanning electron microscopy-electron probe microanalysis study of the interface between apatite and wollastonite-containing glass-ceramic and rabbit tibia under load-bearing conditions after long-term implantation

Glass-ceramic implants containing oxy- and fluoroapatite [Ca10(PO4)6(O, F2)] and beta-wollastonite (CaSiO3) were studied under load-bearing conditions in a segmental replacement model in the tibia of the rabbit. A 16-mm segment of the middle of the tibial shaft was resected at a point distal to the junction of the tibia and the fibula. The defect was replaced by a 15 mm-long hollow, cylindrical implant that was fixed by intramedullary nailing using Kirschner wire. The implants were 9 mm in diameter and 15 mm long bearing a central hole 3.05 mm in dianeter. The rabbits used were killed 6 months, 1 year, 18 months, and 2 years after implantation. The interface between the bone and the glass-ceramic was investigated by scanning electron microscopy-electron-probe microanalysis (SEM-EPMA). None of the glass-ceramic implants broke, and the glass-ceramic had bonded directly to the bone tissue without any intervening soft tissue. A calcium-phosphorus layer (Ca-P layer) was observed at the glass-ceramic/bone interface. This layer was 30-100 microns thick at 6 months after implantation, 60-110 microns thick at 1 year after implantation, 80-200 microns thick at 18 months, and 120-350 microns thick at 2 years. At the lateral surface of the glass-ceramic uncovered by the bone, the calcium-phosphorus layer was 50-80 microns thick at 6 months after implantation, 250-450 microns thick at 1 year, 300 approximately 400 microns thick at 18 months, and 300 microns thick at 2 years. The thickness of the calcium-phosphorus layer increased moderately after long-term implantation. However, it was difficult to estimate the rate of increase in the thickness of calcium-phosphorus layer.

Calcium efflux from cultured bovine adrenal chromaffin cells induced by pituitary adenylate cyclase-activating polypeptide (PACAP): possible involvement of an Na+/Ca2+ exchange mechanism

The effect of pituitary adenylate cyclase-activating polypeptide 1-38 (PACAP1-38) on Ca2+ efflux from cultured bovine adrenal chromaffin cells was examined. PACAP1-38 stimulated the efflux of 45Ca2+ from the cells in a concentration dependent manner (10(-9)-10(-7)M). This effect was inhibited by its potent receptor antagonist PACAP6-38. PACAP1-38 increased the formation of [3H]inositol phosphates and cyclic AMP in the cells. Forskolin, an activator of adenylate cyclase, also stimulated the efflux of 45Ca2+ from the cells. 3-Isobutyl-1-methylxanthine (IBMX), an inhibitor of phosphodiesterase, enhanced PACAP1-38-induced 45Ca2+ efflux from the cells. Phorbol 12-myristate 13-acetate (PMA), an activator of protein kinase C, had no effect on the efflux of 45Ca2+ from the cells. The increases in 45Ca2+ efflux induced by PACAP1-38 and forskolin were reduced by deprivation of extracellular Na+ and the Na+/Ca2+ exchange inhibitor amiloride. In addition, PACAP1-38 stimulated 22Na+ influx into the cells, and this action was inhibited by amiloride. These results suggest that PACAP1-38 stimulates an Na+/Ca2+ exchange mechanism through activation of adenylate cyclase in cultured bovine adrenal chromaffin cells.

[Measurement of anti-acetylcholine receptor antibody using human rhabdomyosarcoma cell line]

We developed a radioimmunoassay for AChR Ab using AChR solubilized from membrane extracts of human rhabdomyosarcoma cell line (RD cell). The binding affinity of this AChR to the alpha-Bungarotoxin (alpha-BTX) was similar to that of AChR from cell surface. Lyophilized AChR was stable within two months at -20 degrees C. In our assay system, sera from patients with Myasthenia Gravis (MG) showed markedly high titers and frequency (94%) of anti-AChR Ab. On the other hand, almost all sera from normal and non-myasthenic patients such as rheumatoid arthritis and thyroid disease were negative (< 0.2nmol/l). Our assay using AChR from RD cells shows sufficient results in the intra- and inter-CV values, and recovery and dilution tests. AChR Ab titers of our assay showed good correlations with those measured by AChRs from both human ischemic muscles and TE671 cells (commercial kit). The radioimmunoassay for AChR Ab using the membrane extracts of RD cells has high sensitivity, specificity and stability. Therefore, the assay is valuable as the routine assay for the diagnosis of MG.

Evaluation of novel platinum complexes, inhibitors of topoisomerase I and II in non-small cell lung cancer (NSCLC) sublines resistant to cisplatin

We determined the in vitro cytotoxicities of promising new platinum complexes, an inhibitor of topoisomerase I, and novel anthracycline derivatives, and examined using clonogenic assay whether these compounds are cross-resistant in CDDP-resistant sublines derived from human non-small cell lung cancer (NSCLC) cell lines. Cytotoxicities were evaluated by means of the relative antitumor activity (RAA = peak plasma concentration/IC50 values), which we reported previously as a model for predicting antitumor activity. Of the CDDP analogues tested, including carboplatin (CBDCA), [(glycolate-0,0') diammineplatinum (II) (254-S)], ormaplatin [tetrachloro-(d,1-trans)- 1,2-diaminocyclohexaneplatinum (IV) (OP)] and oxaliplatin [oxalato (trans-1-1,2-diaminocyclohexane) platinum (II) (1-OHP)], no agent showed superior antitumor activity compared to CDDP. ME2303 [7-O-(2,6-dideoxy-2-fluoro-alpha-L-talopyranosyl) adriamycinone-14-O -pimelate], a new anthracycline derivative, showed higher antitumor activity than adriamycin (ADM). The CDDPresistant sublines, PC-9/CDDP and PC-14/CDDP, were 18.3- and 7.7-fold more resistant to CDDP compared to the respective parent cell lines. The CDDP analogues were all cross-resistant to CDDP and the order of relative resistance values was CBDCA > 254-S > 1-OHP > OP for PC9/CDDP and 254-S > CBDCA > 1-OHP > OP for PC-14/CDDP. Although OP showed cross-resistance to CDDP, OP was the most active against the CDDP-resistant sublines with relative resistance values of 3.8 and 1.6 for PC-9/CDDP and PC-14/CDDP, respectively. ME2303 and CPT-11, [7-ethyl-10-(4-[1-piperidino]-1-piperidino) carbonyloxycamptothecin], an inhibitor of topoisomerase I, was active against CDDP-resistant human NSCLC cell lines. These results suggest that OP, ME2303 and CPT-11 could be active in patients with, NSCLC clinically resistant to CDDP.

Autogenous callo-osseous grafts for the repair of osteochondral defects

We describe a new method of biological repair of osteochondral defects. In rabbit knees an osteochondral defect was reconstructed with a callo-osseous graft made of a superficial sheet of medullary fracture callus attached to a base of cancellous bone. This was taken from the iliac bone of the same animal which had been osteotomised ten days earlier. The reparative tissues were evaluated for 24 weeks by quantitative histology, biochemical analysis of the uronic acid content, and immunohistochemical staining of collagen constituents. The callo-osseous graft provided significantly faster and better repair of the articular surface than an untreated defect or a callo-osseous graft in which the cells had been devitalised by irradiation before transplantation. Our findings indicate that the callo-osseous graft contributes to the repair process by providing both favourable extracellular matrices and pluripotential mesenchymal cells. Our study tested the hypothesis that early medullary callus generates hyaline cartilage instead of bone after transfer to an articular surface.

Useful laser source criteria for optical storage employing extended eye-diagram jitter theory

In view of the recent progress in visible lasers for next-generation optical disks, we describe the influence of source wavelength, aberration, and noise on eye-diagram jitter, which determines the ultimate disk density. The analysis indicates that the sources used in a readout of a 6× areal density, (4,22) run-length-limited code with a minimum mark length of 0.4 µm must have a wavelength that satisfies the Nyquist condition of relationship between the spot size and the minimum mark length, a wave-front aberration of less than 0.035 rms λ, and relative intensity noise of less than -125 dB/Hz.

Autogenous callo-osseous grafts for the repair of osteochondral defects

We describe a new method of biological repair of osteochondral defects. In rabbit knees an osteochondral defect was reconstructed with a callo-osseous graft made of a superficial sheet of medullary fracture callus attached to a base of cancellous bone. This was taken from the iliac bone of the same animal which had been osteotomised ten days earlier. The reparative tissues were evaluated for 24 weeks by quantitative histology, biochemical analysis of the uronic acid content, and immunohistochemical staining of collagen constituents. The callo-osseous graft provided significantly faster and better repair of the articular surface than an untreated defect or a callo-osseous graft in which the cells had been devitalised by irradiation before transplantation. Our findings indicate that the callo-osseous graft contributes to the repair process by providing both favourable extracellular matrices and pluripotential mesenchymal cells. Our study tested the hypothesis that early medullary callus generates hyaline cartilage instead of bone after transfer to an articular surface.

Disseminated intravascular coagulopathy in infection compared with that in malignant neoplasia

The organic symptoms and results of coagulation tests of disseminated intravascular coagulopathy (DIC) in 17 patients with infection were compared with those in 12 patients with malignancy. The infectious diseases were mainly sepsis and pneumonia, and the malignancy was mainly lung cancer. The mean antithrombin III (AT III) before treatment was 54% in infection and 68% in malignancy, and the AT III values improved after administration of 1500 U of AT III concentrates per day. The mean thrombin-antithrombin complex level decreased from 22 ng/ml to 9 ng/ml after the treatment in infection, but it increased in malignancy. There were no differences in DIC scores between infection and malignancy before treatment; however, the scores were significantly more improved in infection than in malignancy after treatment (p < 0.05). The fibrin/fibrinogen degradation product level, platelet count, and fibronectin level were also significantly more improved in infection than in malignancy. This better response to treatment in infection than in malignancy is probably due to eradication of the causative organisms by antibiotics in infection. These data suggest that therapy against both DIC and the underlying disease is crucial for successful treatment.

NM23-H1 and NM23-H2 messenger RNA abundance in human hepatocellular carcinoma

nm23 was originally identified as an antimetastatic gene, the expression of which was inversely correlated with tumor metastatic potential in rodent model systems. Subsequently, two related human nm23 genes, nm23-H1 and nm23-H2, were identified. The relationship between expression of nm23-H1 and nm23-H2 in hepatocellular carcinoma specimens from 30 patients and metastatic potential was investigated with the use of a quantitative reverse transcription-PCR procedure. The abundance of nm23-H1 and nm23-H2 mRNA was compared with serum alpha-fetoprotein concentration, tumor size (maximum diameter), and histopathological parameters such as portal vein tumor thrombus, intrahepatic metastasis, capsular formation, capsular infiltration, differentiation of tumor cells, and TNM stage. The abundance of nm23-H1 mRNA showed a significant inverse correlation with intrahepatic metastasis and TNM stage. Furthermore, we confirmed that reduced expression of nm23-H1 mRNA was in accordance with a reduced amount of NM23-H1 protein using Western blot analysis. No correlation was apparent between nm23-H2 mRNA abundance and intrahepatic metastasis. These data support the conclusion that nm23-H1 may play a more important role than nm23-H2 in intrahepatic metastasis in hepatocellular carcinoma. Furthermore, nm23-H1 mRNA abundance may be a predictor of intrahepatic metastasis, the most important factor correlated with the metastatic potential of hepatocellular carcinoma.

Posttranscriptional regulation of the c-myb proto-oncogene in estrogen receptor-positive breast cancer cells

We have determined that expression of the c-myb proto-oncogene is associated with estrogen receptor (ER) status and not with tumor progression in human breast epithelial cells. Analysis of normal, immortalized, nontumorigenic, and tumorigenic mammary epithelial cells showed that only ER+ tumor cell lines expressed readily detectable levels of c-myb mRNA and a Mr 75,000 protein that was the same size as the c-myb transcripts and protein products present in hematopoietic cells. In this report we show that c-myb mRNA and protein levels are down-regulated during estrogen withdrawal. A 20-fold increase in c-myb mRNA and protein expression was observed upon addition of beta-estradiol to the culture medium. Nuclear run-on transcription analyses showed that c-myb was transcribed at the same rate in the presence and absence of estrogen, suggesting that c-myb mRNA accumulation was regulated at a posttranscriptional level. To provide additional evidence that c-myb mRNA was dependent on ER expression, we examined c-myb mRNA levels in MCF-7 cells selected for resistance to antineoplastic drugs. c-myb expression was decreased only in cell lines that showed concomitant loss of ER expression. Moreover, c-myb mRNA was expressed and modulated by estrogen in ER-, MDA-MB-231 cells stably transfected with a human ER gene. When considered together, these data indicate that c-myb mRNA levels are regulated by estrogens and further suggest that this proto-oncogene plays a role in the biology of ER+ breast tumor cells.

Synthesis and conformational investigation of tandem repeat sequence in RNA polymerase II

The largest subunit of RNA polymerase II has a very interesting sequence in the C-terminus; that is, a tandem repeat sequence of Ser-Pro-Thr-Ser-Pro-Ser-Tyr consisted of proline residues and three kinds of residues having side-chain hydroxyl groups. Although lack of this tandem repeat is a lethal event in vivo, its functional role is unclear. The sequential polypeptide corresponding to this tandem repeat, poly(Ser-Pro-Thr-Ser-Pro-Ser-Tyr), was synthesized and its conformation was investigated by circular dichroism comparing to the monomeric heptapeptide. In addition, the theoretical conformational analysis based on the molecular mechanics was tried for the heptapeptide in the repeating unit and the periodic polyheptapeptide corresponding to the tandem repeat sequence. These results suggested the possibility that the tandem repeat contains a kind of super conformation composed of the repetitive turn structure in the native state. The characteristic repetitive turn structure would be the key of its function mechanism.

Small depressed cancer of the large bowel: report of three cases

This report describes three patients in whom colonoscopy detected small depressed cancers (without an elevated component) that had invaded the submucosa. They represent 0.4% (3/884) of all patients with invasive cancers and 3% (3/101) of patients with submucosal cancers in the National Cancer Center Hospital between January 1990 and February 1994. This type of cancer may have been overlooked in the past because of its small, flat nature. A slight deformity of the lumen, a faint color change (slightly reddish), and a loss of a vascular network pattern were important colonoscopic findings. Small depressed cancers may follow a different pathway to advanced cancer than polypoid cancers, although both pathways are included in the adenoma-carcinoma sequence. We should be aware of these lesions in our efforts to detect colorectal cancers in the early stage.

Lansoprazole for maintenance therapy of peptic ulcer disease: weekend full-dose or everyday half-dose administration?

Seventy-one patients with peptic ulcer (44 gastric ulcer and 27 duodenal ulcer patients) were enrolled in this study. After the ulcers had healed with 2 months of treatment with lansoprazole (LPZ) 30 mg/day, patients were divided into two groups: 43 in the half-dose q.d. group and 28 in the weekend full-dose group. Fourteen (23%) of the 43 patients in the half-dose q.d. group and 14 of the 28 (50%) in the weekend full-dose group failed to continue taking the drug for 6 months owing to poor compliance (p < 0.05). None of the 30 patients who continued to take the maintenance dose of LPZ experienced ulcer recurrence during the 6-month follow-up period, whereas 71% of the patients who stopped taking LPZ experienced recurrence (p < 0.01). In conclusion, maintenance therapy using the half-dose q.d. administration schedule was superior to weekend full-dose administration because of the better patient compliance and a lower ulcer recurrence rate.