Absorption of epirubicin instilled intravesically immediately after transurethral resection of superficial bladder cancer

As postoperative adjuvant therapy for superficial bladder cancer, intravesical instillation therapy is commonly conducted. In this case, from the view point of prevention of intraoperative dissemination, commencement of instillation therapy at an early postoperative period is preferred. However, increased drug permeability is suspected because of damage to the bladder mucosa during operation. Therefore, this study was conducted to investigate the plasma level of epirubicin (EPI) instilled immediately after transurethral operation. EPI (20 mg/40 ml or 50 mg/100 ml) was instilled immediately after a transurethral operation, and retained in the bladder for 1 h. Blood samples were obtained before instillation, as well as 30, 60, 120 and 240 min after instillation, and EPI levels were assayed. The mean EPI concentrations (ng/ml) among the 20-mg/40 ml group (n = 5) were < 2.5 and < 2.0 at 30 and 60 min, respectively, after which they were undetectable. The 50-mg/100 ml group (n = 5) recorded 5.0, 4.4 and < 3.0 after 30, 60 and 120 min, respectively, and after 240 min it was undetectable. Intravesical instillation of EPI immediately after a transurethral operation causes a small increase in the plasma level and it is thought to cause small systemic side effects.

Results of pharmacokinetic modulating chemotherapy in combination with hepatic arterial 5-fluorouracil infusion and oral UFT after resection of hepatic colorectal metastases

BACKGROUND

Pharmacokinetic modulating chemotherapy (PMC) is a new therapeutic concept in combination with continuous 5-fluorouracil (5-FU) infusion and UFT. UFT enhanced plasma 5-FU concentration and antitumor effects during 5-FU infusion. The authors report on their experiences with arterial 5-FU infusion and UFT after resection of hepatic colorectal secondaries.

METHODS

Fifty-eight patients were divided into two groups after hepatectomy. Group A, 30 patients, underwent hepatic arterial infusion (HAI) via implantable port system with perfusion 5-FU for 2 consecutive days per week at 600 mg/m(2)/day, and oral administration of UFT at 400 mg/day for 5-7 days per week, repeated 10 times, and Group B, 28 patients, underwent oral administration of UFT at 400 mg/day for 6 months. All the patients were managed at the outpatient clinic at Hyogo College of Medicine, and recurrence, survival, and toxicity were documented. Plasma 5-FU concentrations during chemotherapy were detected using high performance liquid chromatography.

RESULTS

Maximum plasma concentrations of 5-FU in Group A reached 144.0 ng/mL and in Group B 58.7 ng/mL. Cumulative 5-year survival rate after hepatectomy in Group A was 59% and in Group B was 27%. (P = 0.00001) HAI-PMC drastically decreased hepatic recurrence (median hepatic recurrence free times were 34.2 months in Group A vs. 18.4 months in Group B; P = 0.00002). Grade 3 toxicity in Group A was found in 3 patients

CONCLUSIONS

Pharmacokinetic modulating chemotherapy was designed as a uracil-related biochemical modulation. HAI-PMC significantly decreased hepatic recurrence after curative resection. This new chemotherapy concept significantly improved prognosis in patients with hepatic colorectal metastases.

The endolymphatic sac in patients with Ménière's disease: correlation between the MRI and the surgical findings

The endolymphatic sac (ES) is thought to have close relations to pathogenesis of endolymphatic hydrops. Here is reported a retrospective study of 41 patients (42 ears) with Meniere's disease who underwent MRI prior to endolymphatic sac surgery. Based on proton-density weighted image (PDI) and T2-weighted image (T2), the ES including an endolymphatic duct (ED) were estimated whether it was detectable or not. Fourteen ESs were detected on both images (Group A), 14 ESs were detected only on PDI (Group B), and the remaining 14 ESs were not detected on either image (Group D). The actual shape of the sac, obtained from surgical findings, was classified into three (normoplastic, atrophic, invisible). Seventeen ears showed normoplastic ESs and 14 showed atrophic ESs. ES was not detected in 11 ears during surgery, and these findings were compared with image classification. From the study data, normoplastic ESs tend to be observed on both images whereas atrophic or invisible sacs were hardly observed on T2. This classification of ES on MRI was thought to correlate with surgical findings and this correlation was statistically significant (Spearman's rank correlation coefficient. r(s) = 0.58, p < 0.01).

Haemophilus influenzae infection and Guillain-Barré syndrome

It has been reported recently that Haemophilus influenzae can elicit an axonal form of Guillain-Barré syndrome. To investigate the incidence and features of H. influenzae-related Guillain-Barré syndrome, anti-H. influenzae antibody titres were measured by enzyme-linked immunosorbent assay (ELISA) in 46 consecutive Japanese patients with Guillain-Barré syndrome, 49 normal controls, 24 patients with multiple sclerosis and 27 patients with amyotrophic lateral sclerosis (ALS). Whole bacteria of non-encapsulated (non-typable) H. influenzae isolated from one of the Guillain-Barré syndrome patients was the antigen used. Elevated anti-H. influenzae antibodies for two or three classes of IgG, IgM and IgA were found in six (13%) Guillain-Barré syndrome patients, but not in the normal controls and patients with multiple sclerosis or ALS. The incidence was significantly higher in patients with Guillain-Barré syndrome than in the normal controls (P = 0.01) and patients with multiple sclerosis or ALS (P = 0.009). Western blot analysis confirmed that the H. influenzae-positive patients' IgG recognized the lipopolysaccharides of H. influenzae. Guillain-Barré syndrome patients with anti-H. influenzae antibodies showed relatively uniform clinical and laboratory features: prodromal respiratory infection, less frequent cranial and sensory nerve involvement, pure motor axonal degeneration on electrophysiology, and positivity for IgG anti-GM1 antibodies. Although the features were similar to those in Guillain-Barré syndrome patients infected by Campylobacter jejuni, the recoveries seemed to be better in patients with H. influenzae-related Guillain-Barré syndrome. It is concluded that a form of Guillain-Barré syndrome occurs after respiratory infection by H. influenzae in the Japanese population. A particular strain of non-typable H. influenzae has a ganglioside GM1-like structure and elicits axonal Guillain-Barré syndrome similar to C. jejuni-related Guillain-Barré syndrome.

[The proposal of the activities of daily living (ADL) index for institutionalized older adults]

The purpose of this study was to propose the ADL index constructed with a unidimensional scale based on item difficulty for institutionalized older adults. Six hundreds and three subjects (159 males and 444 females) were divided into the following four groups based on assisting devices for movement: G1 did not use assisting devices for movement; G2 used a stick or a walker; G3 used a wheelchair; G4 could not move. As the results of examinations from the points of the approximation of proportions, non-answer rates and agreement rates of each item according to 74 ADL items representing 9 ADL domains, the 27 ADL items were selected as utility items. The reliability and unidimensionality of the ADL index consisting of 27 items were considered to be high. As the results of examining the difficulty of items and ADL ability characteristics of each group, the ADL concerning movement and other lower limb activity in G1 and G2, and concerning changes of posture and manual activity in G3 and G4 were considered to reflect the individual differences of ADL ability, respectively. The numbers of ADL items which should first be assessed in each group were as follows: 20 items in G1; 21 items in G2; 21 items in G3; 11 items in G4.

Results of pharmacokinetic modulating chemotherapy in combination with hepatic arterial 5-fluorouracil infusion and oral UFT after resection of hepatic colorectal metastases

BACKGROUND

Pharmacokinetic modulating chemotherapy (PMC) is a new therapeutic concept in combination with continuous 5-fluorouracil (5-FU) infusion and UFT. UFT enhanced plasma 5-FU concentration and antitumor effects during 5-FU infusion. The authors report on their experiences with arterial 5-FU infusion and UFT after resection of hepatic colorectal secondaries.

METHODS

Fifty-eight patients were divided into two groups after hepatectomy. Group A, 30 patients, underwent hepatic arterial infusion (HAI) via implantable port system with perfusion 5-FU for 2 consecutive days per week at 600 mg/m(2)/day, and oral administration of UFT at 400 mg/day for 5-7 days per week, repeated 10 times, and Group B, 28 patients, underwent oral administration of UFT at 400 mg/day for 6 months. All the patients were managed at the outpatient clinic at Hyogo College of Medicine, and recurrence, survival, and toxicity were documented. Plasma 5-FU concentrations during chemotherapy were detected using high performance liquid chromatography.

RESULTS

Maximum plasma concentrations of 5-FU in Group A reached 144.0 ng/mL and in Group B 58.7 ng/mL. Cumulative 5-year survival rate after hepatectomy in Group A was 59% and in Group B was 27%. (P = 0.00001) HAI-PMC drastically decreased hepatic recurrence (median hepatic recurrence free times were 34.2 months in Group A vs. 18.4 months in Group B; P = 0.00002). Grade 3 toxicity in Group A was found in 3 patients

CONCLUSIONS

Pharmacokinetic modulating chemotherapy was designed as a uracil-related biochemical modulation. HAI-PMC significantly decreased hepatic recurrence after curative resection. This new chemotherapy concept significantly improved prognosis in patients with hepatic colorectal metastases.

Tissue factor pathway inhibitor-2 suppresses the production of active matrix metalloproteinase-2 and is down-regulated in cells harboring activated ras oncogenes

A human placenta cDNA expression library was screened for genes inducing flat reversion when transfected into a v-K-ras-transformed NIH3T3 cell line, DT. One such gene was found to encode a Kunitz-type serine protease inhibitor, tissue factor pathway inhibitor-2 (TFPI-2). While the TFPI-2 mRNA can be detected in normal human fibroblasts (MRC-5), it is down-regulated in MRC-5 cells expressing an activated H-ras oncogene and in the human fibrosarcoma cell line, HT1080. Restored expression of the TFPI-2 gene in HT1080 cells resulted in the suppression of matrix invasion activity in vitro with concomitant decrease in the relative amount of active matrix metalloproteinase-2 secreted from the cells. When DT cells were cultured in the presence of conditioned medium and extracellular matrix prepared from TFPI-2-transfected HT1080 cells, increased attachment and flat reversion were observed. These results suggest that TFPI-2 may be required for the maintenance of the integrity of extracellular matrix in normal tissues and its down-regulation as a result of oncogene activation may contribute to the malignant phenotypes of tumor cells.

Rapid oscillation of insulin release by the rat pancreatic islets under stringent Ca2+-free conditions

Oscillation of insulin release by the pancreatic islets was evaluated under stringent Ca(2+)-free conditions for the first time. Isolated single rat islets were exposed to 16.7 mM glucose in the presence of 1.9 mM Ca(2+), or under the stringent Ca(2+)-free conditions (Ca(2+) omission with 1 mM EGTA, 6 microM forskolin and 100 nM phorbol 12-myristate 13-acetate). Fifteen minutes after the initiation of glucose stimulation, effluent was collected at a 6-s interval, insulin was determined in duplicate by a highly sensitive insulin radioimmunoassay, and oscillation and pulsatility of release statistically analyzed. Significant oscillation of insulin release was observed in all islets irrespective of presence and absence of Ca(2+). Significant pulsatility of release was detected in 7 of 11 islets in the presence of Ca(2+) and three of six isl! ets in the absence of Ca(2+). In conclusion, high glucose elicits oscillatory insulin release both in the presence and absence of extracellular Ca(2+).

Novel proteinaceous toxins from the box jellyfish (sea wasp) Carybdea rastoni

During summer and autumn, the box jellyfish (sea wasp) Carybdea rastoni is one of the most bothersome stinging pests to swimmers and bathers on the Japanese coast. Two labile but potent hemolytic toxins from the tentacles of Carybdea rastoni were isolated in their active forms using newly developed purification methods. The molecular masses of the isolated C. rastoni toxin-A and toxin-B (CrTX-A and CrTX-B) are 43 and 46 kDa, respectively, as calculated from SDS-PAGE. In the present study, we sequenced the full-length cDNA (1600 bp), which encodes both CrTX-A and CrTX-B. The deduced 450 amino acid sequence of the CrTXs, showed no significant homology with any known protein. This report presents the first complete sequence of a proteinaceous jellyfish toxin. Furthermore, it was revealed that CrTX-A was primarily localized in the nematocyst, whereas CrTX-B was detected only in the tentacle. Because the nematocyst is the organ responsible for the cnidarian sting, the remainder of the study focused on the toxicity of CrTX-A. We found that CrTX-A was fatally toxic to mice at 20 microg/kg (i.v.) and crayfish at 5 microg/kg (i.p.). Subcutaneously injected CrTX-A (0.1 microg) caused inflammation of mouse skin. These results showed that CrTX-A is responsible for the cutaneous inflammation observed in humans stung by C. rastoni.

Prevalence of diabetes estimated by plasma glucose criteria combined with standardized measurement of HbA1c among health checkup participants on Miyako Island, Japan

OBJECTIVE

To estimate the prevalence of diabetes in participants of an annual health checkup in the district of the Miyako Public Health Center (Okinawa, Japan) by using the revised criteria of the Japan Diabetes Society (JDS).

RESEARCH DESIGN AND METHODS

The subjects studied here were all Japanese and 45-75 years of age at the time of the health examination in 1998. Diagnosis of diabetes was based on the following: 1) fasting plasma glucose > or =7.0 mmol/l, 2) casual plasma glucose > or =11.1 mmol/l, 3) HbA(1c) > or =6.1%, and 4) self-report on a special questionnaire given at the examination. The HbA(1c) value was standardized by the measurement of 2 standard samples provided by the JDS.

RESULTS

Among the 2,621 subjects, 59.7% had their fasting blood glucose levels measured. Of the subjects diagnosed as having diabetes, 154 (12.6%) were men and 115 (8.6%) women. Among the subjects newly diagnosed with diabetes from their fasting blood glucose levels. 27.5% of the men and 21.9% of the women had diagnoses based on HbA(1c) alone. Overall, 34.9% of the subjects with newly diagnosed diabetes were identified by plasma glucose (PG) alone and 33.0% were diagnosed by HbA(1c) alone.

CONCLUSIONS

The combination of PG and HbA(1c) resulted in a considerable increase in newly diagnosed diabetes as compared with the use of only one of these parameters. Considering the convenience and correlation with vascular complications, use of the 2 tests may be beneficial in epidemiological studies of the Japanese population to identify high-risk groups for micro- and macrovascular diseases.

Surgical management of genital prolapse: is chain cystourethrography useful for evaluating anatomical corrections and urinary symptoms after surgery?

OBJECTIVE

To evaluate the relationship between chain cystourethrography and surgery for genital prolapse and urinary symptoms.

METHODS

A retrospective study of women with genital prolapse was conducted from January 1991 through December 1997. To assess the preoperative and postoperative anatomical situations objectively, chain cystourethrography was performed.

RESULTS

Fifty-seven patients underwent surgical repairs for genital prolapse. All of them recovered from the genital prolapse both subjectively and objectively after surgery. Chain cystourethrography is useful for evaluating postoperative anatomical corrections. However, 6 patients (12%) suffered from a recurrent feeling of genital prolapse, and 14 patients (28%) had urinary symptoms postoperatively.

CONCLUSIONS

Our treatment showed good anatomical corrections based on chain cystourethrography, and there were no prognostic differences among the surgical procedures. However, anatomical correction does not always mean improvement of urinary symptoms. Further studies are needed to clarify what factors contribute to the prognosis in such cases.

[Construction of a subjective fatigue scale for adolescent students]

OBJECTIVE

There is no appropriate scale to evaluate subjective symptoms of fatigue (SSF) in everyday life in adolescent students. An existing scale long before constructed for laborers has been used. It is essential to establish a practical, rational scale. The purpose of this study was to construct a practical scale to measure subjective symptoms of fatigue for high school and college students.

METHODS

A questionnaire on SSF was administered to 5,435 students aged 15-20 yr. Factor analysis based on the oblique Promax rotation method was applied to a correlation matrix consisting of 44 items.

RESULTS

Six factors were interpreted as follows: difficulty with concentrated thinking, languor, reduced activation, reduced motivation, drowsiness and feeling of physical disintegration. A subjective fatigue scale (SFS-Y: 24 items) was constructed using these factors. The eigen-value of principal component analysis, alpha reliability coefficients, and test-retest reliability coefficients for each subscale were very high.

CONCLUSION

The SFS-Y generated in the present study is a very practical scale with high validity and reliability.

[Virucidal activity of disinfectants. Influence of the serum protein upon the virucidal activity of disinfectants]

Five disinfectants were tested for virucidal activity on three DNA viruses and three RNA viruses in the presence or absence of serum protein. Disinfectants of the aldehyde and halogen groups had a virucidal activity on human herpes virus, bovine rhabdo virus, human immunodeficiency virus, human adeno virus, porcine parvo virus, and polio virus. Disinfectants of the invert and amphoteric soap groups, and biganide group had a destructive effect on RNA and DNA viruses possessing an envelope. The presence of serum protein exerted great influence upon the virucidal activity of disinfectants of the invert and amphoteric soap groups.

An improved genetic linkage map of rat chromosome 20

BACKGROUND AND PURPOSE

Rat chromosome 20 is one of special interest because it contains some diabetogenic genes, such as a major histocompatibilitiy complex (MHC)-linked genetic components and quantitative trait loci. We studied rat chromosome 20, using the backcross progeny between BB/Wor and PVG.R23 rats, and confirmed the genetic linkage map by use of another backcross panel.

METHODS

Backcross panels were done between BB/Wor and PVG.R23 rats, and BN and KZC rats. Length variations of simple sequence length polymorphism markers were analyzed by use of polymerase chain reaction (PCR) analysis. Alleles of RT1-Bb and RT1-Db were analyzed by use of the PCR-restriction fragment length polymorphism method. Genetic maps of rat chromosome 20 were constructed, using the Map Manager computer program.

RESULTS

Fifty-two loci were mapped on rat chromosome 20. Genetic length was 57.9 cM, with average spanning of 1.11 cM between markers. The positions of RT1-N1, Tnf, and RT1-Bb into the MHC region were separated and confirmed by results of two backcross panels in our linkage studies.

CONCLUSIONS

The genetic linkage map of rat chromosome 20 was improved, and was a useful tool for genetic analysis of a diabetogenic gene(s) and for producing MHC congenic strains.

Identification and expression of a novel 3'-exon of mouse Runx1/Pebp2alphaB/Cbfa2/AML1 gene

Cbfa1 (recently renamed as Runx2) is prerequisite for the differentiation of osteoblasts that play a central role in regulation of bone metabolism. Runx transcription factors belong to Drosophila pair rule gene "runt" family that also play critical roles during the development of hematopoietic tissues or insect bodies. To identify novel sequences related to Runx (Cbfa) genes, we screened a 11 d.p.c (days postcoitum) mouse embryonic cDNA library using a probe corresponding to Runx2 (Cbfa1) runt domain and identified a novel cDNA fragment. This cDNA (521-41) is about 2.4 kb in length and contains a sequence identical to the N-terminal half of mouse Runx1 (Pebp2alphaB/Cbfa2/AML1b) and a novel protein coding sequence in the C-terminal region. High expression levels of 521-41 mRNA were observed during the early mouse embryogenesis. In adult mice, 521-41 mRNA was expressed ubiquitously in lumbar vertebrae, brain, kidney, heart, muscle, and ovary. We also found that 521-41 mRNA was constitutively expressed in an osteoblast-like cell line, MC3T3E1. These data indicate that 521-41 gene is a novel splicing variant of mouse Runx1 which is expressed in skeletal tissues and osteoblast-like cells.

Improvement of multiple pathophysiological phenotypes of klotho (kl/kl) mice by adenovirus-mediated expression of the klotho gene

BACKGROUND

We have established a novel mouse mutant, klotho (kl), by insertional mutation of a transgene and identified the structural gene. The mouse homozygous for the mutation exhibits multiple pathological conditions resembling age-related disorders in humans and can be regarded as a model of human premature aging syndromes. However, the pathophysiological role of Klotho protein has not been clarified.

METHODS

A replication-deficient adenoviral vector expressing the membrane form of the mouse klotho gene was constructed and we examined Klotho expression in vitro. The recombinant adenoviral vector was then administered intravenously into klotho mice at 4-5 weeks of age and its therapeutic potential was examined.

RESULTS

Expression of Klotho protein was observed in the adenoviral vector-infected CHO cells. The klotho mice infused with the recombinant adenovirus showed a significant extension of life span and gain in body weight at 1 week after treatment. Macroscopic and histological analyses demonstrated the improvement of multiple pathological findings such as restoration from atrophy and cell formation and differentiation in the gonadal cells, immune tissues and subcutaneous fat.

CONCLUSION

We showed that local expression of the klotho gene retards or partially improves pathological abnormalities in several organs of klotho mice after onset of the phenotypes. Therefore, the recombinant adenovirus vector will provide an important tool for investigating the molecular mechanism of the Klotho protein and give clues to understanding the individual disease mechanisms.

An osteogenesis-related transcription factor, core-binding factor A1, is constitutively expressed in the chondrocytic cell line TC6, and its expression is upregulated by bone morphogenetic protein-2

Core-binding factor A1 (Cbfa1), also called Pebp2 alpha A/AML3, is a transcription factor that belongs to the runt-domain gene family. Cbfa1-deficient mice are completely incapable of both endochondral and intramembranous bone formation, indicating that Cbfa1 is indispensable for osteogenesis. Maturation of chondrocytes in these mice is also disorganized, suggesting that Cbfa1 may also play a role in chondrogenesis. The aim of this study was to examine the expression and regulation of Pebp2 alpha A/AML3/Cbfa1 expression in the chondrocyte-like cell line, TC6. Northern blot analysis indicated that Cbfa1 mRNA was constitutively expressed as a 6.3 kb message in TC6 cells and the level of Cbfa1 expression was enhanced by treatment with bone morphogenetic protein-2 (BMP2) in a time- and dose-dependent manner. This effect was blocked by an RNA polymerase inhibitor, 5,6-dichloro-1-beta-d-ribofuranosylbenzimidazole, but not by a protein synthesis inhibitor, cycloheximide. Western blot analysis of the cell lysates using polyclonal antibody raised against Cbfa1 indicated that BMP2 treatment increased the Cbfa1 protein level in TC6 cells. In TC6 cells, BMP2 treatment enhanced expression of alkaline phosphatase and type I collagen mRNAs but suppressed that of type II collagen mRNA. In addition to TC6 cells, Cbfa1 mRNA was also expressed in primary cultures of chondrocytes and BMP2 treatment enhanced Cbfa1 mRNA expression in these cells similarly to its effect on TC6 cells. These data indicate that the Pebp2 alpha A/AML3/Cbfa1 gene is expressed in a chondrocyte-like cell line, TC6, and its expression is enhanced by treatment with BMP.

Binding of avian ovomucoid to shiga-like toxin type 1 and its utilization for receptor analog affinity chromatography

Development of a simple and efficient purification procedure for Shiga-like toxin I (Stx1) was attempted. Since it has been suggested that pigeon egg white ovomucoid carries a P1 antigenic determinant, we examined its ability to bind Stx1. The ovomucoid glycoprotein fraction (GPro) was prepared from pigeon egg white by acetone precipitation, and a portion of the GPro was treated with pronase to obtain the glycopeptide fraction (GPep). When both GPro and GPep were coupled to CNBr-activated Sepharose 4B and subjected to affinity chromatography, Stx1 specifically bound to both columns. The Stx1 eluted with a buffer containing 4.5 M MgCl2 was shown to be highly purified to homogeneity by polyacrylamide gel electrophoresis under denatured condition; only two protein bands with molecular weights of 32,000 and 8000, which correspond to the A and the B subunits of Stx1, respectively, were recognized. The purified toxin showed cytotoxicity on Vero cells with a specific activity of approximately 6 x 10(8) CD50/mg protein; almost 100% of the activity was recovered from Escherichia coli cell lysate. We propose that the utilization of avian ovmucoid for the affinity chromatography provides a potentially simple, convenient, and widely available method to purify Shiga-like toxins.

Enhancement of poly-adenosine diphosphate-ribosylation in human hepatocellular carcinoma

BACKGROUND

Poly-adenosine diphosphate (ADP)-ribosylation, catalysed by poly(ADP-ribose) polymerase (PARP), is a post-translational modification of nuclear proteins and is involved in a wide range of biological processes including DNA repair, cell proliferation and malignant transformation. Alteration of this reaction in human hepatocellular carcinoma (HCC) is of interest, but has not yet been explored. The aim of this study was to evaluate poly-ADP-ribosylation and to compare the expression of PARP in HCC and adjacent non-tumour tissues.

METHODS

Tumorous and adjacent non-tumorous tissues were obtained from five consecutive patients with HCC during surgery for tumour resection. Tissue homogenates were subjected to ADP-ribosylation with [32P]-nicotinamide adenine dinucleotide. The ADP-ribosylated proteins were separated by sodium dodecylsulfate-polyacrylamide gel electrophoresis, followed by autoradiography. Expression of PARP was also evaluated by western blotting.

RESULTS

Several proteins were ADP-ribosylated in human HCC tissues. Notably, the radiolabelling of a 116-kDa protein was remarkably greater than that in adjacent non-tumorous tissues (86.5 +/- 35.2 arbitrary units by densitometry vs 12.2 +/- 9.9, mean +/- SD, n = 5, P < 0.02). The radiolabelling of the 116-kDa protein was decreased in the presence of PARP inhibitors in a concentration-dependent manner. Immunoblot analyses revealed that the radiolabelled protein was PARP and that its expression was significantly greater in HCC than in adjacent non-tumorous tissues (333 +/- 204% of non-tumorous tissue, P < 0.05).

CONCLUSIONS

We found that poly-ADP-ribosylation and PARP expression were significantly increased in human HCC compared with those in adjacent non-tumorous tissues in surgically obtained specimens.

Identification of a series of transforming growth factor beta-responsive genes by retrovirus-mediated gene trap screening

Transforming growth factor beta (TGF-beta) plays important roles in the regulation of proliferation, differentiation, apoptosis, and carcinogenesis. To identify genes responsible for maintaining the phenotype induced by TGF-beta, we performed a retrovirus-mediated gene trap screening designed to isolate TGF-beta-responsive genes in human lung carcinoma cell line A549. After screening 249 trap lines, 21 were found to express the reporter beta-galactosidase gene in a TGF-beta-responsive manner. Interestingly, in large proportions of these trap lines, the reporter gene was responsive also to phorbol ester and was suppressed by gamma interferon. Fragments of all these trapped genes were recovered by 5'- and 3'-rapid amplification of cDNA ends (RACE), and in 15 out of 21 cases (71%), the TGF-beta responsiveness of the endogenous genes was confirmed by RNA blot hybridization. In at least five cases, the TGF-beta-induced upregulation was found to be cycloheximide resistant, suggesting the roles of the genes in the TGF-beta-induced primary responses. Sequence analyses revealed that 43% (9 of 21) of the trapped genes were novel and that the remainder included genes previously reported to be upregulated by TGF-beta, such as epidermal growth factor receptor and beta1 integrin, documenting the validity of this approach. Other known genes include the ones encoding the proteins associated with cell proliferation (ribosomal proteins S15a, hNRP/NAP-1, and lipocortin II), focal adhesions (paxillin), and transcriptional regulation (thyroid hormone receptor activator molecule 1 [TRAM-1]).

Development of EIA systems for active-form MAP kinase

Quantitative sandwich enzyme immunoassay (EIA) systems, that can distinguish between active-form subtypes of mitogen-activated protein kinases (p44 and p42 MAP kinase, also called ERK1 and ERK2), were developed employing subtype-specific antibodies as a solid phase and an antibody specific for the phosphorylated region of MAP kinases as the detector. Using these systems, we investigated the dynamic changes in the activity of ERK1 and ERK2 in platelet-derived growth factor (PDGF)-treated rat mesangial cells and nerve growth factor (NGF)-treated PC12. Both ERK1 and ERK2 were activated immediately after stimulation, and the activity reached a maximum at 5-10 min. The total activity of both subtypes correlated well with that obtained using the conventional method. Compared with the usual methods, these systems should have a higher specificity and be more convenient and suitable for experiments with multiple samples. Moreover, as these EIA systems can be applied not only to rat MAP kinases but also to human, mouse and rabbit MAP kinases, they are potentially very useful for a range of investigations.

SOX9 enhances aggrecan gene promoter/enhancer activity and is up-regulated by retinoic acid in a cartilage-derived cell line, TC6

SOX9 is a transcription factor that plays a key role in chondrogenesis. Aggrecan is one of the major structural components in cartilage; however, the molecular mechanism of aggrecan gene regulation has not yet been fully elucidated. TC6 is a clonal chondrocytic cell line derived from articular cartilage. The purpose of this study was to examine whether SOX9 modulates aggrecan gene expression and to further identify molecules that regulate Sox9 expression in TC6 cells. SOX9 overexpression in TC6 cells enhanced by approximately 3-fold the transcriptional activity of the AgCAT-8 construct containing 8-kilobase (kb) promoter/first exon/first intron fragments of the aggrecan gene. SOX9 enhancement of aggrecan promoter activity was lost when we deleted a 4.5-kb fragment from the 3'-end of the 8-kb fragment corresponding to the region including the first intron. In TC6 cells, SOX9 enhanced the transcriptional activity of a reporter construct containing the Sry/Sox consensus sequence >10-fold. SOX9 enhancement of aggrecan gene promoter activity and SOX9 transactivation through the Sry/Sox consensus sequence were not observed in osteoblastic osteosarcoma cells (ROS17/2.8), indicating the dependence on the cellular background. Northern blot analysis indicated that TC6 cells constitutively express Sox9 mRNA at relatively low levels. To examine regulation of Sox9 gene expression, we investigated the effects of calciotropic hormones and cytokines. Among these, retinoic acid (RA) specifically enhanced Sox9 mRNA expression in TC6 cells. The basal levels of Sox9 expression and its enhancement by RA were observed similarly at both permissive (33 degrees C) and nonpermissive (39 degrees C) temperatures. Furthermore, RA treatment enhanced the transcriptional activity of a reporter construct containing the Sry/Sox consensus sequence in TC6 cells. Moreover, RA treatment also enhanced the transcriptional activity of another reporter construct containing the enhancer region of the type II procollagen gene in TC6 cells. These observations indicate that SOX9 enhances aggrecan promoter activity and that its expression is up-regulated by RA in TC6 cells.

Transient over-expression of NGFI-A gene suppresses NGF-induced neurite outgrowth in PCI2 cells

Using an inducible gene expression system (Tet-ON system), the role of NGFI-A gene during the neuronal differentiation of PCI2 cells was examined. When NGFI-A was transiently over-expressed, no obvious effects on cell proliferation or neurite outgrowth were observed. Interestingly, however, NGFI-A over-expression resulted in significant retardation in NGF-induced neurite outgrowth. Similar suppressive effects were observed also on the v-K-ras-induced neurite outgrowth. These results raise the possibility that NGFI-A protein may play some negative role in NGF signaling.

Antibiotic susceptibility of bacteria detected from the root canal exudate of persistent apical periodontitis

Intracanal exudates in persistent endodontic cases were sampled for detecting bacteria using a preculture method, and the antibiotic susceptibility of the bacteria identified was examined. Twelve species were recovered from 15 cases. The species most commonly detected were alpha-Streptococcus and Enterococcus. The results of the antibiotic susceptibility tests revealed that Enterococcus was highly resistant to antibiotics tested, especially to cephalosporin products. Enterococcus is known as one of the bacteria that show multidrug resistance. In cases of prolonged endodontic treatment, a specific antibiotic prescription would play an important role for efficient treatment. Collecting data about antibiotic susceptibility could be helpful. Identification, however, take approximately 2 wk and a further study to develop the method that rapidly informs us about the antibiotic susceptibility that might be needed.

Expression of Indian hedgehog during fracture healing in adult rat femora

Indian hedgehog (Ihh) has recently been shown to be expressed in prehypertrophic and hypertrophic chondrocytes during embryonic development, and it has been implicated in the regulation of terminal differentiation of chondrocytes. In this paper we examined the expression of Ihh during fracture healing in an adult rat model. A transverse diaphyseal fracture was made in the right femur, and the expression of Ihh in the fracture callus was examined at 1, 2, and 3 weeks after fracture. Northern blot analysis demonstrated the expression of Ihh mRNA in these tissues. Immunohistological analysis detected hedgehog protein in prehypertrophic chondrocytes in the fracture callus at 1 week after fracture. From 2 weeks and on, positive staining was observed in hypertrophic chondrocytes as well. At 3 weeks, some of the osteoblasts close to the endochondral ossification front were also stained positive for hedgehog protein. Our data indicate that Ihh is expressed in chondrocytes and osteoblasts during the process of fracture healing in adult rat femora, suggesting that Ihh, a regulator of endochondral ossification in embryonic development, may also play a role in the regulation of bone formation during fracture repair in adult animals.

Induction of erythroid differentiation by inhibition of Ras/ERK pathway in a friend murine leukemia cell line

The role of Ras and MAP kinases (MAPKs) in the regulation of erythroid differentiation was studied using a cell line (SKT6) derived from Friend virus (Anemic strain)-induced murine erythroleukemia. This cell line undergoes differentiation in vitro in response to erythropoietin (EPO) or other chemical inducers such as dimethylsulfoxide (DMSO). When a constitutively active ras mutant (ras12V) was expressed in SKT6 cells, EPO-induced differentiation was inhibited. Conversely, a dominant negative ras mutant (ras17N) induced differentiation even in the absence of EPO, suggesting that the basal Ras activity is essential for the maintenance of the undifferentiated phenotype and proliferative potential in this cell line. Rapid inactivation of ERK was observed after expression of ras17N. Slow but significant inactivation of ERK was also observed during EPO-induced differentiation. Furthermore, overexpression of a constitutively active mutant of ERK-activating kinase (MAPKK) was found to suppress erythroid differentiation, while pharmacological inhibition of MAPKK induced differentiation. These findings suggest that down-regulation of Ras/ERK signaling pathway may be an essential event in EPO-induced erythroid differentiation in this system.

Pleiotrophin signals increased tyrosine phosphorylation of beta beta-catenin through inactivation of the intrinsic catalytic activity of the receptor-type protein tyrosine phosphatase beta/zeta

Pleiotrophin (PTN) is a platelet-derived growth factor-inducible, 18-kDa heparin-binding cytokine that signals diverse phenotypes in normal and deregulated cellular growth and differentiation. To seek the mechanisms of PTN signaling, we studied the interactions of PTN with the receptor protein tyrosine phosphatase (RPTP) beta/zeta in U373-MG cells. Our results suggest that PTN is a natural ligand for RPTP beta/zeta. PTN signals through "ligand-dependent receptor inactivation" of RPTP beta/zeta and disrupts its normal roles in the regulation of steady-state tyrosine phosphorylation of downstream signaling molecules. We have found that PTN binds to and functionally inactivates the catalytic activity of RPTP beta/zeta. We also have found that an active site-containing domain of RPTP beta/zeta both binds beta-catenin and functionally reduces its levels of tyrosine phosphorylation when added to lysates of pervanidate-treated cells. In contrast, an (inactivating) active-site mutant of RPTP beta/zeta also binds beta-catenin but fails to reduce tyrosine phosphorylation of beta-catenin. Finally, in parallel to its ability to inactivate endogenous RPTP beta/zeta, PTN sharply increases tyrosine phosphorylation of beta-catenin in PTN-treated cells. The results suggest that in unstimulated cells, RPTP beta/zeta is intrinsically active and functions as an important regulator in the reciprocal control of the steady-state tyrosine phosphorylation levels of beta-catenin by tyrosine kinases and phosphatases. The results also suggest that RPTP beta/zeta is a functional receptor for PTN; PTN signals through ligand-dependent receptor inactivation of RPTP beta/zeta to increase levels of tyrosine phosphorylation of beta-catenin to initiate downstream signaling. PTN is the first natural ligand identified for any of the RPTP family; its identification provides a unique tool to pursue the novel signaling pathway activated by PTN and the relationship of PTN signaling with other pathways regulating beta-catenin.

Up-regulated cytoplasmic expression, with reduced membranous distribution, of the src substrate p120(ctn) in gastric carcinoma

p120(ctn) is a substrate of the tyrosine kinase pp60 src. Tyrosine kinases such as src localize to the adherens junctions and phosphorylate junctional proteins in both normal and transformed cells.(1) p120(ctn) forms a complex with E-cadherin at the adherens junction and is phosphorylated by ligands such as epidermal growth factor receptor as well as pp60 src. Phosphorylation of p120(ctn) has been shown to correlate with cell transformation. The aim of this study was to investigate in vivo expression of p120(ctn) in gastric carcinoma and to examine any relationship to pathological characteristics and patient survival. Immunohistochemical staining for p120(ctn) was performed in 68 gastric carcinoma specimens (19 diffuse, 49 intestinal type), in 22 lymph node metastases, and in gastric mucosal biopsies from 16 patients with gastric dysplasia and ten healthy controls. Up-regulation of p120(ctn) cytoplasmic staining was seen in six (37 per cent) of the gastric dysplasia cases and in 45 (66 per cent) tumours (89 per cent of diffuse and 57 per cent of intestinal tumours). Loss of membranous distribution of staining for p120(ctn) was seen in 22 (32 per cent) tumours (52 per cent of diffuse and 24 per cent of intestinal tumours). The staining pattern in the primary tumour showed no correlation with tumour type, grade, or stage, or patient survival. Of 22 lymph node metastases examined, 13 (60 per cent) showed loss of membranous staining. In conclusion, staining for p120(ctn) in gastric carcinoma and dysplasia revealed marked up-regulation of cytoplasmic staining, sometimes associated with reduced membranous expression. Up-regulation of expression of p120(ctn) has not previously been described in human epithelial malignancy. The significance of these findings is uncertain, but they may reflect a change in tyrosine kinase signal transduction pathways, and a role for p120(ctn) in ligand-induced mitogenic signalling and cell transformation.

Endoscopic mucosal resection using a partial transparent hood for lesions located tangentially to the endoscope

BACKGROUND

Numerous methods have been developed to resect early-stage gastric and esophageal cancers, but it is difficult to resect lesions viewed tangentially with the endoscope.

METHODS

We have designed and developed an original method of endoscopic mucosal resection using a partial transparent hood to treat difficult cases in which the lesions are located tangentially to the endoscope. The hood was attached on the right side of the endoscope and, after insertion into the stomach or the esophagus, was lightly pressed on the orad side of the lesion. Then the lesion was resected using grasping forceps and electrosurgical current snare.

RESULTS

The average diameter of specimens was 26 +/- 8 mm in gastric lesions and 20 +/- 3 mm in esophageal lesions, both 6 mm larger than those obtained by previous methods.

CONCLUSION

This device and technique were extremely useful for mucosal resection of lesions located tangentially to the endoscope.

Measurement of bromate in bread by liquid chromatography with post-column flow reactor detection

This method is suitable for the determination of bromate residues in a variety of baked goods. The peer-verified method trial was performed on white bread, multigrain bread, and coffee cake spiked with known levels of potassium bromate. The analytical portion is extracted with deionized water to remove bromate from the bulk of the baked product. The aqueous extract is carried through a series of steps to remove co-extractives that would interfere with the liquid chromatography (LC) in the determinative step or hasten the deterioration of the LC column. The extract is filtered before passing it through a reversed-phase solid-phase extraction (SPE) column and a cation-exchange column in the silver form to remove lipids and chloride, respectively. Ultrafiltration is then used to remove proteins with molecular weights of >30,000 daltons. Finally, a cation-exchange column in the sodium form is used to remove silver ions from the extract. The determinative step uses LC with a reversed-phase column and an ion-pairing agent in the mobile phase. Detection is based on the post-column reaction of bromate with o-dianisidine to form an oxidation product that is quantitated spectrophotometrically at 450 nm. Overall agreement between the submitting and peer laboratories was quite good. For bromate levels of 10-52 ppb, overall mean recoveries were 76.9 and 78.8% for the submitting and peer laboratories, respectively. The standard deviations were higher for the results of the peer laboratory, probably because of the generally higher level of baseline noise present in the chromatograms. The results demonstrate that the method provides adequate accuracy with low-fat as well as high-fat foods. Bromate at levels as low as 5 ppb (ng/g) can be detected with the method.

High-resolution micro-computed tomography analyses of the abnormal trabecular bone structures in klotho gene mutant mice

Inactivation mutation of the recently discovered klotho gene in mice causes a syndrome resembling aging. Manifestations include short life span, atherosclerosis, gonadal atropy, skin atropy, emphysema, ataxia and ectopic calcification. These mice also exhibit abnormally high bone density in the epiphyses of their tibiae based on X-ray and histological analyses. However, micro-structures of the trabecular bones in arbitrary two-dimensional planes or three-dimensional regions are difficult to analyze by these techniques. Therefore, we applied high resolution micro-computed tomography (microCT) to characterize the micro-structural abnormality in the trabecular bone in long bones as well as in vertebrae of four- to six-week-old klotho mutant mice. Two-dimensional microCT analyses in the mid-sagittal plane as well as three-dimensional microCT analyses indicated that the trabecular bone volume fraction measured in the proximal metaphyses of the tibiae was increased more than twofold in klotho mutant mice compared with the wild-type mice. Similarly, the trabecular bone area fraction in the mid-sagittal plane of the lumbar vertebral bodies was also increased by about 80% at the proximal and distal ends. No significant difference was observed with regard to the cortical thickness in the mid-shaft of femora between klotho mutant and wild-type mice. Three-dimensional microCT analyses also indicated that the trabecular number and thickness of the proximal metaphyses of the tibiae were increased by about 80% and 300% respectively in the klotho mutant mice, while trabecular separation was 60% less in klotho mutant mice compared with the wild-type mice. These quantitative microCT analyses indicate that the inactivation of klotho gene expression results in an increase in three-dimensional bone volume fraction, number and thickness of the trabecular bones in these mice.

Differential tetraethylammonium sensitivity of KCNQ1-4 potassium channels

In Shaker-group potassium channels the presence of a tyrosine residue, just downstream of the pore signature sequence GYG, determines sensitivity to tetraethylammonium (TEA). The KCNQ family of channels has a variety of amino acid residues in the equivalent position. We studied the effect of TEA on currents generated by KCNQ homomers and heteromers expressed in CHO cells. We used wild-type KCNQ1-4 channels and heteromeric KCNQ2/3 channels incorporating either wild-type KCNQ3 subunits or a mutated KCNQ3 in which tyrosine replaced threonine at position 323 (mutant T323Y). IC50 values were (mM): KCNQ1, 5.0; KCNQ2, 0.3; KCNQ3, > 30; KCNQ4, 3.0; KCNQ2 + KCNQ3, 3.8; and KCNQ2 + KCNQ3(T323Y), 0.5. While the high TEA sensitivity of KCNQ2 may be conferred by a tyrosine residue lacking in the other channels, the intermediate TEA sensitivity of KCNQ1 and KCNQ4 implies that other residues are also important in determining TEA block of the KCNQ channels.

Treatment of ununited fracture of the hook of hamate by low-intensity pulsed ultrasound: a case report

A patient presented 4 months after sustaining a fracture of the hook of hamate. X-rays and computed tomography scanning of the carpal tunnel confirmed the presence of an ununited fracture. Low-intensity ultrasound was applied to the fracture site. After 4.5 months of exposure to ultrasound, union was confirmed by both x-rays and computed tomography scanning of the carpal tunnel. (J Hand Surg 2000; 25A:77-79.

AMPA-kainate subtypes of glutamate receptor in rat cerebral microglia

Microglial cells were isolated from rat cerebral cortex, and kainate (KA)-induced inward current was measured at a holding potential of -40 or -60 mV. 6-Cyano-7-nitroquinoxaline-2, 3-dione-sensitive KA-induced currents increased with increasing KA concentration. The half-activation concentration and Hill coefficient were 3.3 x 10(-4) M and 1.4, respectively. Although glutamate (Glu) and AMPA-induced currents were much smaller than that induced by KA, all KA-, Glu-, and AMPA-induced currents were greatly and consistently enhanced in the presence of cyclothiazide (CTZ). On the other hand, KA-induced currents were much less sensitive to potentiation by concanavain A, suggesting that the KA-induced response in rat microglia is predominantly mediated by AMPA-preferring receptors (subunits GluR1-GluR4). The current-voltage relationships of KA- and AMPA-CTZ-induced currents were almost linear or slightly outward rectifying. The reversal potential of KA-induced current shifted to negative potentials (from +4 to -40 mV) on switching from high Na(+) to high Ca(2+) external solution, indicating the low Ca(2+) permeability through the AMPA-KA receptor channel complexes. AMPA-KA receptor expression was studied with immunohistochemistry and reverse transcription-PCR, from which GluR2, GluR3, GluR4, and GluR5 were identified. Lower levels of mRNAs for GluR7 and KA-1-KA-2 were also indicated. Finally, activation of these receptors with KA or Glu significantly enhanced the production of tumor necrosis factor-alpha. These results suggest that primary cultured rat microglia possesses functional Glu receptor, which may mediate neuron to microglia communication in the physiological and pathological states.

Retardation in bone resorption after bone marrow ablation in klotho mutant mice

The klotho gene mutant mice exhibit both osteopetrotic phenotype, including elongation of trabeculae in the epiphyses of long bones and vertebral bodies, and osteopenic phenotype, such as thin cortical bones in the diaphyses of these bones. These diverse features raise the question of whether the klotho gene defect results in alteration in bone resorption in vivo. Therefore, we examined the effect of the klotho gene defect on bone resorption by using bone marrow ablation model. At 1 week after bone marrow ablation, trabecular bones were formed in the ablated marrow cavity to levels higher than those in unablated bones in both klotho mutant and wild-type mice. At 2 weeks postsurgery, newly formed trabecular bones were resorbed in wild-type mice to resume normal bone marrow and trabecular bone volume fraction as reported previously. In contrast, the newly formed trabecular bones in the ablated marrow in klotho mutant mice remained at levels similar to those at 1 week. The defect in the bone resorption phase in klotho mutant mice is associated with site-specific reduction of the number and size of osteoclasts in klotho mutant mice. Moreover, the expression levels of osteoprotegerin messenger RNA in the ablated femora of klotho mutant mice were higher than those in wild-type mice. These results indicate that lack of klotho gene expression suppressed bone resorption that should normally take place 2 weeks after bone marrow ablation.

Enhancement of the growth of Helicobacter pylori in Brucella broth by hydrogen peroxide

We found that a sub-lethal concentration of hydrogen peroxide (HPOx) enhanced the growth of Helicobacter pylori in Brucella broth supplemented with 10% fetal bovine serum (BB/FBS). The enhancement was evident at 0.1 mM HPOx and reached a maximun at 3.5 mM. The growth stimulation was dependent on the basal media used; when brain heart infusion broth (BHIB) was used instead of BB, the growth was not altered regardless of the presence or absence of HPOx. Furthermore, the growth in BHIB/FBS was comparable to that in BB/FBS plus 3.5 mM HPOx. This suggested that the enhancement of growth by HPOx resulted from the derepression of the inhibitory factor existing in BB by HPOx. The inhibitory substance seemed to be bisulfite salt since the bacteria grew to a similar extent in bisulfite-less Brucella broth (BLBB0)/FBS compared to the bacterial growth in BHIB/FBS and BB/FBS plus HPOx. These results indicate that the detoxification of bisulfite in BB can be easily achieved by simply adding HPOx to the medium, which causes the oxidation of bisulfite to bisulfate, a less-toxic compound to the bacterial growth. Since we also found that the morphology and cellular protein profile of BB/FBS-cultured bacteria were apparently different from those cultured in BLBB/FBS, we propose that the use of BB for primary isolation and cultivation of H. pylori should be limited on certain occasions, or if necessary, BB can be used after detoxification of the bisulfite by the addition of a low concentration of HPOx.

HPLC analysis of dental resin composites components

Five uncured commercial dental resin composites (two bis-glycidyl methacrylate based products and three non-bis-glycidyl methacrylate based products) were examined for contamination with bisphenol A, which is a known xenobiotic. After the samples were processed with acetonitrile for extraction of their components, high performance liquid chromatography analysis was performed and the eluted peaks were fractionated for comparison using UV spectra. The results suggested that all the resin composites tested were contaminated with bisphenol A or its derivatives. Theoretically, bisphenol A is not a component of dental resin composite, but it could remain as an impurity of the composite during the synthesis of Bis-GMA. The results suggest that it is necessary to investigate the ability of this impurity and its derivatives in dental resin composites to cause estrogenic effects, as well as to evaluate the release of the impurity from cured resin composites.

Cytotoxicity and mutagenicity of UVB assessed using cultured rat fibroblast

A retroviral vector carrying both positive (neo) and negative (herpes simplex virus thymidine kinase or HSV-tk) selection markers was constructed as a substrate for mutational assay in mammalian cells. Using a population of rat fibroblast cells carrying a single copy per cell of retroviral DNA randomly integrated in their chromosomes, we examined the cytotoxic and mutagenic activities of ultraviolet light (UV) at four wavelengths (254, 290, 300, and 320 nm). The action spectra for these activities are similar to some of the previously reported spectra for photochemical DNA modifications, erythema, cell killing, and mouse skin carcinogenesis, except at 290 and 320 nm. At 290 nm, no significant mutagenicity was observed. At 320 nm, both cytotoxic and mutagenic activities were 10 times higher than the values expected from the absorption spectrum for DNA and the action spectrum for bacterial inactivation and mutagenesis. Structural comparison of some of the HSV-tk mutants obtained after irradiation with 300 and 320 nm UV revealed partially different patterns of mutation specificity, suggesting the involvement of multiple molecular mechanisms in the genotoxicity associated with this range of UV.

Coordinated expression of noggin and bone morphogenetic proteins (BMPs) during early skeletogenesis and induction of noggin expression by BMP-7

Coordinated regulation of the activities of bone morphogenetic protein (BMP) and its inhibitors is essential for skeletal development since loss-of-function experiments show that both BMPs and BMP inhibitory signals, such as noggin, are required to establish proper formation of skeletal tissues. In this paper, we asked how and when noggin would be functional to interact with BMPs during skeletogenesis in mammals. For this purpose, we first analyzed the spatial and temporal patterns of noggin, BMP-2, BMP-4, and BMP-7 expression during early skeletogenesis in mouse embryos. In situ hybridization study revealed that noggin expression was detected at a low level in limb mesenchyme, whereas BMP-7 was expressed at a high level throughout limb mesenchyme 10.5 days postcoitum (dpc) in mouse embryos. One day later, noggin mRNA was expressed at a high level in the prechondrogenic condensations in appendicular and axial skeletal primordia, where sox9 transcripts were also expressed. At this stage, noggin-expressing cells were surrounded by those expressing BMP-7. The chondrogenic cell condensation continued to express noggin transcripts in 12.5 dpc and 13.5 dpc embryos, and again the noggin-expressing cells within the cartilaginous tissue were surrounded by those expressing BMP-7. We further examined interaction of noggin and BMPs by using organ cultures of 11.5 dpc mouse forelimbs and found that implantation of carriers containing BMP-7 protein into the forelimb explants induced noggin expression in the limb mesenchyme. BMP-7 also induced type II collagen and sox9 mRNAs in the same cell population, indicating that noggin induction occurred in the chondrogenic precursor cells. BMP-7 effects on noggin expression were observed in a dose-dependent manner within a dose range of 10-100 ng/microliter. These results suggest that BMP-7 induced expression of noggin transcripts within skeletal cell condensation and that this noggin expression in turn could act antagonistically to attenuate BMP action in the early skeletogenesis.

Calbindin-D(28k) controls [Ca(2+)](i) and insulin release. Evidence obtained from calbindin-d(28k) knockout mice and beta cell lines

The role of the calcium-binding protein, calbindin-D(28k) in potassium/depolarization-stimulated increases in the cytosolic free Ca(2+) concentration ([Ca(2+)](i)) and insulin release was investigated in pancreatic islets from calbindin-D(28k) nullmutant mice (knockouts; KO) or wild type mice and beta cell lines stably transfected and overexpressing calbindin. Using single islets from KO mice and stimulation with 45 mM KCl, the peak of [Ca(2+)](i) was 3.5-fold greater in islets from KO mice compared with wild type islets (p < 0.01) and [Ca(2+)](i) remained higher during the plateau phase. In addition to the increase in [Ca(2+)](i) in response to KCl there was also a significant increase in insulin release in islets isolated from KO mice. Evidence for modulation by calbindin of [Ca(2+)](i) and insulin release was also noted using beta cell lines. Rat calbindin was stably expressed in betaTC-3 and betaHC-13 cells. In response to depolarizing concentrations of K(+), insulin release was decreased by 45-47% in calbindin expressing betaTC cells and was decreased by 70-80% in calbindin expressing betaHC cells compared with insulin release from vector transfected betaTC or betaHC cells (p < 0.01). In addition, the K(+)-stimulated intracellular calcium peak was markedly inhibited in calbindin expressing betaHC cells compared with vector transfected cells (225 nM versus 1,100 nM, respectively). Buffering of the depolarization-induced rise in [Ca(2+)](i) was also observed in calbindin expressing betaTC cells. In summary, our findings, using both isolated islets from calbindin-D(28k) KO mice and beta cell lines, establish a role for calbindin in the modulation of depolarization-stimulated insulin release and suggest that calbindin can control the rate of insulin release via regulation of [Ca(2+)](i).

Sympathetic potentiation of cyclic ADP-ribose formation in rat cardiac myocytes

We examined the role of cyclic ADP-ribose (cADP-ribose) as a second messenger downstream of adrenergic receptors in the heart after excitation of sympathetic neurons. To address this question, ADP-ribosyl cyclase activity was measured as the rate of [(3)H]cADP-ribose formation from [(3)H]NAD(+) in a crude membrane fraction of rat ventricular myocytes. Isoproterenol at 1 microM increased ADP-ribosyl cyclase activity by 1.7-fold in ventricular muscle; this increase was inhibited by propranolol. The stimulatory effect on the cyclase was mimicked by 10 nM GTP and 10 microM guanosine 5'-3-O-(thio)triphosphate, whereas 10 microM GTP inhibited the cyclase. Cholera toxin blocked the activation of the cyclase by isoproterenol and GTP. The above effects of isoproterenol and GTP in ventricular membranes were confirmed by cyclic GDP-ribose formation fluorometrically. These results demonstrate the existence of a signal pathway from beta-adrenergic receptors to membrane-bound ADP-ribosyl cyclase via G protein in the ventricular muscle cells and suggest that increased cADP-ribose synthesis is involved in up-regulation of cardiac function by sympathetic stimulation.

Molecular cloning and biological activity of a novel Ha-Ras suppressor gene predominantly expressed in skeletal muscle, heart, brain, and bone marrow by differential display using clonal mouse EC cells, ATDC5

We cloned a cDNA encoding a novel mouse protein, named A-C1, by differential display between two mouse cell lines: embryonic fibroblast C3H10T1/2 and chondrogenic ATDC5. The deduced amino acid sequence of A-C1 consists of 167 amino acids and shows 46% identity with that of a ras-responsive gene, rat Ha-rev107. Northern blot analysis showed a distinct hybridization band of 3.2 kilobases. Expression of A-C1 mRNA was detected in undifferentiated ATDC5 cells and myoblastic C2C12 cells, while none of C3H10T1/2 cells, NIH3T3 fibroblasts, Balb/c 3T3 fibroblasts, osteoblastic MC3T3-E1 cells, and ST2 bone marrow stromal cells expressed A-C1 mRNA in vitro. Moreover, A-C1 mRNA was expressed in skeletal muscle, heart, brain, and bone marrow in adult mice. By in situ hybridization, A-C1 gene expression was localized in hippocampus as well as bone marrow cells. By immunocytochemistry, A-C1 protein was detected in the cytoplasm as well as perinuclear region of the cells. Transfection of A-C1 cDNA into Ha-ras-transformed NIH3T3 cell line caused increase in the number of flat colonies and inhibition of cell growth. Our data indicate that A-C1 is expressed in some specific tissues in vivo and modulates Ha-ras-mediated signaling pathway.