High expression of cyclooxygenase-2 in macrophages of human colonic adenoma

Cyclooxygenase (COX)-2 is a possible molecular target for suppression of colon carcinogenesis by non-steroidal anti-inflammatory drugs (NSAIDs). However, the expression of COX-2 in human colonic tumors during the adenoma-carcinoma sequence has not been elucidated. In the present study, we examined immuno-histochemically the expression and localization of the COX-2 protein in human colonic adenomas and cancers. Twelve human colonic adenomas and 9 advanced cancers were studied. Immunoreactive COX-2 was predominantly and strongly expressed in sub-epithelial interstitial cells broadly present in the surface area of adenomas. The staining pattern of macrophages was similar to that observed for COX-2 in adenomas. Adjacent normal colonic mucosa was negative for COX-2 expression. In contrast, COX-2 was relatively weakly expressed in both tumor cells and interstitial cells in advanced colon cancers. In conclusion, the target of NSAIDs in preventing colon carcinogenesis may be the COX-2 expressed in interstitial cells, possibly macrophages, of colonic adenomas.

High expression of cyclooxygenase-2 in macrophages of human colonic adenoma

Cyclooxygenase (COX)-2 is a possible molecular target for suppression of colon carcinogenesis by non-steroidal anti-inflammatory drugs (NSAIDs). However, the expression of COX-2 in human colonic tumors during the adenoma-carcinoma sequence has not been elucidated. In the present study, we examined immuno-histochemically the expression and localization of the COX-2 protein in human colonic adenomas and cancers. Twelve human colonic adenomas and 9 advanced cancers were studied. Immunoreactive COX-2 was predominantly and strongly expressed in sub-epithelial interstitial cells broadly present in the surface area of adenomas. The staining pattern of macrophages was similar to that observed for COX-2 in adenomas. Adjacent normal colonic mucosa was negative for COX-2 expression. In contrast, COX-2 was relatively weakly expressed in both tumor cells and interstitial cells in advanced colon cancers. In conclusion, the target of NSAIDs in preventing colon carcinogenesis may be the COX-2 expressed in interstitial cells, possibly macrophages, of colonic adenomas.

Massive gastrointestinal hemorrhage in systemic lupus erythematosus: successful treatment with corticosteroid pulse therapy

Although mesenteric vasculitis due to systemic lupus erythematosus (SLE) is relatively uncommon, it is the most dangerous manifestation associated with high mortality. We describe the case of a SLE patient with life-threatening gastrointestinal hemorrhage due to mesenteric vasculitis in whom methylprednisolone pulse therapy was quite effective in controlling the hemorrhage and resulted in a satisfactory long term outcome. A 47-yr-old woman presenting with high fever, rash, and melena was diagnosed with SLE from positive antinuclear antibodies, anti-dsDNA, and low complement titers. Although fever and rash subsided with administration of prednisolone, massive hematemesis appeared with melena. Endoscopy demonstrated bleeding ulceration of the antrum, which was intractable despite intensive antiulcer therapy and transfusion. Surgical exploration revealed ileal penetration, and multiple bleeding ulcerations were observed over the resected ileum as well as the antral ulceration. However, bleeding persisted after surgery and surgical findings prompted us to select methylprednisolone pulse. Hemorrhage responded promptly to the therapy, and the patient has remained well since then for >10 yr. Our report indicates that corticosteroid pulse may serve as one of the therapeutic options for SLE with massive hemorrhage due to widespread mesenteric vasculitis.

[Screening of prostate cancer with PSA and transperineal six sextant biopsy]

OBJECT

The objectives of this study are to examine how many cancer patients we can detect among the outpatients whose PSA values are above 4.0 ng/ml, and to compare the usefulness of transperineal six sextant biopsy (ss-biopsy) with that of transrectal one.

METHODS

All the male outpatients (above 50 years old) were inspected Tandem-R PSA levels and digital rectal examination (DRE). Among them, 129 patients showed more than 4.0 ng/ml of PSA values and/or positive finding of DRE, and underwent subsequent transperineal ss-biopsy.

RESULTS

Cancers were detected in 52 patients (40.3%) without major complications. Among 64 gray zone (PSA 4.1-10.0 ng/ml) patients, 17 (26.6%) were found to be cancer by ss-biopsy, meanwhile only 2 cancer patients (8.9%) were detected from 23 gray zone ones by traditional directed biopsy. Application of PSA density could not be found practicable to eliminate unnecessary biopsies in the gray zone group.

CONCLUSION

Prostate cancer could be found nearly a fourth in the gray zone group of the outpatients. To enhance the detection rate, obtaining at least 6 core samples are recommended from either perineal or rectal root.

A new quantitative method for rabies virus by detection of nucleoprotein in virion using ELISA

We have developed a new quantitative method for rabies virus (RV) detection using enzyme-linked immunosorbent assay (ELISA). The method named N-ELISA was based on the quantitation of nucleoprotein (N) in RV virions captured by RV-specific polyclonal antibodies on an ELISA plate. Both infective and defective interfering (DI) particles of RV could be detected by this method. When viruses were propagated in a medium of pH 7.4 adjusted with 7% NaHCO3, N-ELISA could detect them with titers of more than 10(6) pfu/ml, though the result did not correlate highly with that of the infectivity assay. The reason for this was considered to be that RVs included spikeless and damaged particles which were produced under conditions of low or high pH. However, in the time course of virus yield, titers of N-ELISA correlated well with those of the infectivity assay.

Endoscopic variceal ligation is a sufficient procedure for the treatment of oesophageal varices in patients with hepatitis C liver cirrhosis: comparison with injection sclerotherapy

AIMS

Endoscopic variceal ligation (EVL) is a recently developed alternative to endoscopic injection sclerotherapy (EIS) for the treatment of oesophageal varices. Endoscopic variceal ligation and EIS were compared in an attempt to clarify the efficacy and safety of EVL for patients with cirrhosis due to hepatitis C.

METHODS

Endoscopic variceal ligation was performed in 60 patients and EIS in 30. Varices were eradicated in all patients by EVL and 87% (26 out of 30) by EIS.

RESULTS

There was no significant difference between EVL and EIS in relation to the incidence of bleeding and the 5 year survival rate after treatment. There were no severe complications except mild substernal pain after EVL, while pulmonary embolism occurred in one patient receiving EIS.

CONCLUSIONS

Endoscopic variceal ligation is a safe and effective technique for eradicating oesophageal varices in patients with hepatitis C cirrhosis.

Nonsteroidal anti-inflammatory drugs may prevent colon cancer through suppression of hepatocyte growth factor expression

Nonsteroidal anti-inflammatory drugs which inhibit cyclooxygenase have been reported to suppress colon carcinogenesis. However the mechanism has not yet been elucidated. Growth factors such as hepatocyte growth factor, which are produced by fibroblasts, have been shown to be important in carcinogenesis and the progression of various human cancers. In the present study, we tested the hypothesis that nonsteroidal anti-inflammatory drugs inhibit hepatocyte growth factor expression through an endogenous prostaglandin-mediated pathway in cultured human colonic fibroblasts. Human colonic fibroblasts were obtained from a resected colon and cultured. Hepatocyte growth factor and prostaglandin E2 were measured by enzyme-linked immunosorbent assay. Induction of cyclooxygenase-1 and cyclooxygenase-2 protein was estimated by immunoblotting. Prostaglandins increased hepatocyte growth factor production significantly in a dose- and time-dependent manner. Cholera toxin and 8-bromo cAMP also stimulated hepatocyte growth factor production. Further, prostaglandin E1 significantly increased cellular cAMP. The prostaglandin EP2 and EP4 receptors were detected by reverse transcription-polymerase chain reaction. Interleukin-1beta dramatically increased prostaglandin E2 production and significantly stimulated hepatocyte growth factor synthesis. Interleukin-1beta induced cyclooxygenase-2 but not cyclooxygenase-1 protein. Indomethacin significantly reduced interleukin-1beta-induced prostaglandin E2 release and hepatocyte growth factor production. These results suggest that prostaglandin is a factor for the production of hepatocyte growth factor by human colonic fibroblasts. Nonsteroidal anti-inflammatory drugs may suppress colon carcinogenesis, in part, through the suppression of hepatocyte growth factor expression by inhibiting endogenous prostaglandin production.

Cloning and characterization of a novel Rab-family gene, Rab36, within the region at 22q11.2 that is homozygously deleted in malignant rhabdoid tumors

Malignant rhabdoid tumors (MRTs) are rare, pediatric soft-tissue tumors. Homozygous deletions at chromosome 22q11.2 are a recurrent cytogenetic characteristic of MRTs, an indication that this locus may harbor one or more genes conferring tumor-suppressor activity. We constructed a deletion map of the relevant part of 22q11.2 from a panel of seven MRT cell lines, and isolated a novel gene from the center of the region. As it showed a high degree of sequence homology to genes of the Rab family, we designated it Rab36. The protein encoded by Rab36 was localized at the Golgi body. Sequencing of Rab36 cDNAs from three cell lines that retained at least one allele of this gene revealed no nonsense or frameshift mutations. Experiments to induce over-expression of Rab36 by transfection to an MRT cell line similarly failed to justify designation of this gene as a tumor suppressor that would contribute to tumorigenesis by a loss-of-function mechanism.

Enzymatic analysis of acetylpolyamine

An enzymatic method was proposed for measuring acetylpolyamine (AcPA) alone, even when non-acetylated polyamine co-exists. The method consisted of four enzymatic reactions. First, AcPA was hydrolysed by acylpolyamine amidohydrolase to yield acetate; followed by the other three reactions coupled with three enzymes, respectively, acetate kinase, pyruvate kinase, and lactate dehydrogenase; the acetate formation caused a decrease in NADH. The quantity of AcPA was then evaluated as the change in absorbance at 340 nm. The reagent composition of the reaction mixture was determined, and characteristics of the method were investigated. The validation tests produced satisfactory results. The co-existence of non-acetylated polyamine gave no effect on the measurement. The present method was found to be used easily, rapidly and reliably for the selective determination of AcPA itself.

Endoscopic ligation for non-esophageal variceal upper gastrointestinal hemorrhage

BACKGROUND

Endoscopic ligation can be used for bleeding lesions in non-fibrotic tissue; however, only small numbers of patients with non-esophageal variceal upper gastrointestinal hemorrhage have been treated in this way. To evaluate the utility of the technique, we performed the procedure to treat hemorrhage not from esophageal varices during emergency endoscopy.

PATIENTS AND METHODS

Bleeding was identified from gastric Dieulafoy's ulcers (n=4), duodenal ulcers (n=3), gastric angiodysplasia (n=2) and Mallory-Weiss tears (n=3). The bleeding points were aspirated and controlled by endoscopic ligation and complete hemostasis was achieved in all cases.

RESULTS

Although these lesions were located in difficult areas where endoscopic injection therapy and clipping sometimes fail, endoscopic ligation was performed easily and effectively without complications. Six of the patients had severe underlying disease, including acute and chronic myelogenous leukemia, liver cirrhosis and chronic renal failure; none suffered deterioration in their general condition after endoscopic ligation.

CONCLUSIONS

Our findings suggest that endoscopic ligation is an easy and effective method of treatment for patients with gastrointestinal hemorrhage not from esophageal varices, and is safe even in patients with poor general health.

A mesenteric liposarcoma with production of granulocyte colony-stimulating factor

A 77-year-old female was admitted to our hospital because of pyrexia and a right retroperitoneal mass. Leukocytosis and other inflammatory findings were noted. Bone-marrow aspiration revealed hypercellularity with no malignant cells. An additional mass was detected sonographically in the pelvis. The serum concentration of granulocyte colony-stimulating factor (G-CSF) was highly elevated (299 pg/ml). The tumors were removed at laparotomy, and the pelvic mass was found to arise from the ileocecal mesentery. Postoperatively, white blood cell count and serum G-CSF concentrations decreased to normal levels. The mesenteric tumor showed weakly positive immunostaining for human G-CSF, and Northern and polymerase chain reaction (PCR) analyses detected CSF and its mRNA in the mesenteric tumor.

Follow-up of improvement in regional cerebral blood flow and mental status in Alzheimer's disease: a case report

Cerebral SPECT imaging has the potential to make important contributions in the follow-up care of patients with Alzheimer's disease. An unusual case of a patient who showed a follow-up cerebral blood flow pattern different from that routinely seen in Alzheimer's disease patients is reported here. Qualitative and voxel-based objective evaluation of follow-up scans revealed improvement in parietotemporal deficits that had been observed on a baseline study. This change was observed without significant further deterioration in ratings by dementia batteries. This case shows that a baseline regional cerebral blood flow study might be necessary for reference and comparison in the proper follow-up care of Alzheimer's disease patients.

[Bone marrow relapse in high-risk pediatric patients with acute lymphoblastic leukemia: a comparison of relapse times and initial clinical features of patients on different protocols. Children's Cancer and Leukemia Study group (CCLSG)]

To clarify the efficacy of modern intensive chemotherapy for ALL patients with unfavorable features, we compared the time to failure and initial clinical features of children who relapsed in the bone marrow or combined sites, as documented by early CCLSG studies (H811 and H851; 1981-1987) and later studies (H874 and H/HH911; 1987-1993) concerning high-risk ALL patients. In the later studies patients outcomes with new intensive regimens employing early intensification and reinduction therapy were apparently better than those of patients in the early studies with conventional regimens. When we compared the number of relapsed patients based on duration of first remission, we found that the improved outcomes for patients in the later studies were due to a decrease in the number who relapsed 7-36 months after the start of treatment (intermediate relapse), and that the percentage of those who relapsed within the first 6 months of therapy (early relapse) was higher. Patients with high initial WBC counts tended to relapse much earlier than those with low initial WBC counts. However, in the later studies, patients with high WBC counts often relapsed after the termination of therapy (late relapse). These results suggest that the intensive chemotherapy regimens used in the later studies can prevent the development of drug resistant leukemic clones, except in extremely high-risk patients likely to relapse within the first 6 months of therapy.

Phosphorylation of CrkII adaptor protein at tyrosine 221 by epidermal growth factor receptor

CrkII adaptor protein becomes tyrosine-phosphorylated upon various types of stimulation. We examined whether tyrosine 221, which has been shown to be phosphorylated by c-Abl, was phosphorylated also by other tyrosine kinases, such as epidermal growth factor (EGF) receptor. For this purpose, we developed an antibody that specifically recognizes Tyr221-phosphorylated CrkII, and we demonstrated that CrkII was phosphorylated on Tyr221 upon EGF stimulation. When NRK cells were stimulated with EGF, the tyrosine-phosphorylated CrkII was detected at the periphery of the cells, where ruffling is prominent, suggesting that signaling to CrkII may be involved in EGF-dependent cytoskeletal reorganization. The EGF-dependent phosphorylation of CrkII was also detected in a c-Abl-deficient cell line. Moreover, recombinant CrkII protein was phosphorylated in vitro by EGF receptor. These results strongly suggest that EGF receptor directly phosphorylates CrkII. Mutational analysis revealed that the src homology 2 domain was essential for the phosphorylation of CrkII by EGF receptor but not by c-Abl, arguing that these kinases phosphorylate CrkII by different phosphorylation mechanisms. Finally, we found that the CrkII protein phosphorylated upon EGF stimulation did not bind to the phosphotyrosine-containing peptide and that CrkII initiated dissociation from EGF receptor within 3 min even with the sustained tyrosine phosphorylation of EGF receptor. This result implicated phosphorylation of Tyr221 in the negative regulation of the src homology 2-mediated binding of CrkII to EGF receptor.

Neonatal urinary ascites caused by urinary tract obstruction: two case reports

Two cases of neonatal urinary ascites are reported, one (case 1) caused by posterior urethral valves associated with right vesicoureteral reflux, and the other (case 2) secondary to bilateral obstructed megaureter--a very rare cause. Abdominal distension, electrolyte imbalance, and an elevated BUN/serum creatinine ratio were noted at the time of hospitalization in both cases. These laboratory values promptly returned to normal after the establishment of appropriate urinary drainage, accomplished through bladder catheterization in case 1 and bilateral percutaneous nephrostomy in case 2. In case 1, transurethral resection of the posterior urethral valves was followed by resumption of normal urination. In case 2, bilateral ureteroneocystostomy with ureteral tapering was performed successfully. These are only the fifth and sixth cases of neonatal urinary ascites reported in the Japanese literature.

Monoclonal origin of an esophageal carcinosarcoma producing granulocyte-colony stimulating factor: a case report

BACKGROUND

Carcinosarcomas are comprised of carcinomatous and sarcomatous elements, and their histogenesis remains unclear. The authors examined the serum concentrations of hematopoietic growth factors and performed immunohistochemical studies on an esophageal carcinosarcoma from a patient with marked granulocytosis to determine its histopathogenesis and clonality.

METHODS

The authors examined the case of a 63-year-old man with a polypoid tumor of the esophagus associated with marked leukocytosis (131 x 10(9) per liter). Immunohistochemical staining of the esophageal tumor was performed using monoclonal antibodies against granulocyte-colony stimulating factor (G-CSF), keratin, epithelial membrane antigen (EMA), and vimentin.

RESULTS

The patient's leukocyte count was increased (124 x 10(9) per liter) on admission. Because mature granulocytes predominantly were increased despite the absence of apparent infection, the patient's serum G-CSF concentration was examined and found to be 286.0 pg/mL and to increase with time. After thoracic esophagectomy was performed, granulocyte count and serum G-CSF concentration rapidly normalized. G-CSF concentration was 50-fold higher in the tumor tissue extract than in the extract from normal esophageal tissue. Microscopic examination of the resected specimens revealed that the tumor was comprised of squamous cell carcinoma (SCC) and spindle-shaped sarcomatous elements, and transitional features were observed within these two components. Immunohistochemical examination disclosed cells that were positive for keratin and EMA in the carcinomatous element and vimentin positive cells in the sarcomatous element. However, both types of tumor cells were positive for G-CSF.

CONCLUSIONS

The presence of G-CSF in both SCC cells and spindle-shaped sarcomatous cells indicated that these two components originated from a single clone.

Monoclonal origin of an esophageal carcinosarcoma producing granulocyte-colony stimulating factor: a case report

BACKGROUND

Carcinosarcomas are comprised of carcinomatous and sarcomatous elements, and their histogenesis remains unclear. The authors examined the serum concentrations of hematopoietic growth factors and performed immunohistochemical studies on an esophageal carcinosarcoma from a patient with marked granulocytosis to determine its histopathogenesis and clonality.

METHODS

The authors examined the case of a 63-year-old man with a polypoid tumor of the esophagus associated with marked leukocytosis (131 x 10(9) per liter). Immunohistochemical staining of the esophageal tumor was performed using monoclonal antibodies against granulocyte-colony stimulating factor (G-CSF), keratin, epithelial membrane antigen (EMA), and vimentin.

RESULTS

The patient's leukocyte count was increased (124 x 10(9) per liter) on admission. Because mature granulocytes predominantly were increased despite the absence of apparent infection, the patient's serum G-CSF concentration was examined and found to be 286.0 pg/mL and to increase with time. After thoracic esophagectomy was performed, granulocyte count and serum G-CSF concentration rapidly normalized. G-CSF concentration was 50-fold higher in the tumor tissue extract than in the extract from normal esophageal tissue. Microscopic examination of the resected specimens revealed that the tumor was comprised of squamous cell carcinoma (SCC) and spindle-shaped sarcomatous elements, and transitional features were observed within these two components. Immunohistochemical examination disclosed cells that were positive for keratin and EMA in the carcinomatous element and vimentin positive cells in the sarcomatous element. However, both types of tumor cells were positive for G-CSF.

CONCLUSIONS

The presence of G-CSF in both SCC cells and spindle-shaped sarcomatous cells indicated that these two components originated from a single clone.

Monoclonal origin of an esophageal carcinosarcoma producing granulocyte-colony stimulating factor: a case report

BACKGROUND

Carcinosarcomas are comprised of carcinomatous and sarcomatous elements, and their histogenesis remains unclear. The authors examined the serum concentrations of hematopoietic growth factors and performed immunohistochemical studies on an esophageal carcinosarcoma from a patient with marked granulocytosis to determine its histopathogenesis and clonality.

METHODS

The authors examined the case of a 63-year-old man with a polypoid tumor of the esophagus associated with marked leukocytosis (131 x 10(9) per liter). Immunohistochemical staining of the esophageal tumor was performed using monoclonal antibodies against granulocyte-colony stimulating factor (G-CSF), keratin, epithelial membrane antigen (EMA), and vimentin.

RESULTS

The patient's leukocyte count was increased (124 x 10(9) per liter) on admission. Because mature granulocytes predominantly were increased despite the absence of apparent infection, the patient's serum G-CSF concentration was examined and found to be 286.0 pg/mL and to increase with time. After thoracic esophagectomy was performed, granulocyte count and serum G-CSF concentration rapidly normalized. G-CSF concentration was 50-fold higher in the tumor tissue extract than in the extract from normal esophageal tissue. Microscopic examination of the resected specimens revealed that the tumor was comprised of squamous cell carcinoma (SCC) and spindle-shaped sarcomatous elements, and transitional features were observed within these two components. Immunohistochemical examination disclosed cells that were positive for keratin and EMA in the carcinomatous element and vimentin positive cells in the sarcomatous element. However, both types of tumor cells were positive for G-CSF.

CONCLUSIONS

The presence of G-CSF in both SCC cells and spindle-shaped sarcomatous cells indicated that these two components originated from a single clone.

NRP/B, a novel nuclear matrix protein, associates with p110(RB) and is involved in neuronal differentiation

The nuclear matrix is defined as the insoluble framework of the nucleus and has been implicated in the regulation of gene expression, the cell cycle, and nuclear structural integrity via linkage to intermediate filaments of the cytoskeleton. We have discovered a novel nuclear matrix protein, NRP/B (nuclear restricted protein/brain), which contains two major structural elements: a BTB domain-like structure in the predicted NH2 terminus, and a "kelch motif" in the predicted COOH-terminal domain. NRP/B mRNA (5.5 kb) is predominantly expressed in human fetal and adult brain with minor expression in kidney and pancreas. During mouse embryogenesis, NRP/B mRNA expression is upregulated in the nervous system. The NRP/B protein is expressed in rat primary hippocampal neurons, but not in primary astrocytes. NRP/B expression was upregulated during the differentiation of murine Neuro 2A and human SH-SY5Y neuroblastoma cells. Overexpression of NRP/B in these cells augmented neuronal process formation. Treatment with antisense NRP/B oligodeoxynucleotides inhibited the neurite development of rat primary hippocampal neurons as well as the neuronal process formation during neuronal differentiation of PC-12 cells. Since the hypophosphorylated form of retinoblastoma protein (p110(RB)) is found to be associated with the nuclear matrix and overexpression of p110(RB) induces neuronal differentiation, we investigated whether NRP/B is associated with p110(RB). Both in vivo and in vitro experiments demonstrate that NRP/B can be phosphorylated and can bind to the functionally active hypophosphorylated form of the p110(RB) during neuronal differentiation of SH-SY5Y neuroblastoma cells induced by retinoic acid. Our studies indicate that NRP/B is a novel nuclear matrix protein, specifically expressed in primary neurons, that interacts with p110(RB) and participates in the regulation of neuronal process formation.

Nonsteroidal anti-inflammatory drugs may delay the repair of gastric mucosa by suppressing prostaglandin-mediated increase of hepatocyte growth factor production

Prostaglandins (PGs), hepatocyte growth factor (HGF), and induction of cyclooxygenase (PG synthetase, COX) play important roles in the repair process of gastric mucosa. We hypothesized that nonsteroidal anti-inflammatory drugs (NSAIDs), including indomethacin (IND), retard the healing of ulcers by suppressing these factors. In this study, we investigated the effects of cytokines, growth factors, and IND on production of PG and HGF, and induction of COX using cultured human gastric fibroblasts. Exogenous PGs significantly increased HGF production in a dose-dependent manner. Among various potential stimulants tested, interleukin-1 beta (IL-1 beta) dramatically increased PGE2 production and significantly stimulated HGF production. IL-1 beta induced COX-2 but not COX-1 protein. IND significantly reduced both basal and IL-1 beta-induced PGE2 release and HGF production. These results suggest that the IL-1 beta-PG-HGF pathway plays a role in the repair process of gastric mucosa. Further, NSAIDs may delay the healing of gastric mucosal ulcer, in part through suppression of HGF expression via inhibition of endogenous PG production.

Regulation of cyclin D-dependent kinase activity in rat liver regeneration

The regulation of cyclin D-dependent kinase activity in tissue regeneration in vivo has not been fully described. In young adult rat liver after 70% partial hepatectomy, the association of cyclin D1 with cdk4 was significantly promoted during G1 phase and was maximal at 18 hr, corresponding mainly to late G1. Cyclin D1-dependent kinase activity also strongly increased during G1 phase. The timing of the induction of cyclin D1 / cdk4 complex assembly correlated well with that of cyclin D1-dependent kinase activity. At 18 hr after partial hepatectomy, the amounts of CDK inhibitors p21(CIP1) and p27(KIP1) were also maximal, while only one-tenth of p21(CIP1) and of p27(KIP1) was associated with cyclin D1. These findings suggest that cyclin D1, cdk4 and their association act as promoting factors, and that both p21(CIP1) and p27(KIP1) may have physiological functions as adaptor proteins in additions to their roles as CDK inhibitors in rat liver regeneration.

Hepatocyte growth factor accelerates restitution of intestinal epithelial cells

Many cytokines are involved in the repair of damaged tissue, and one of these, hepatocyte growth factor (HGF), is involved not only with liver regeneration but also in the repair of other tissues. To investigate the importance of HGF in the repair of the small intestine, we evaluated its effect and that of other growth factors in IEC-6 cells, an intestinal epithelial cell line derived from normal rat small intestine. Round "wounds" were made in confluent monolayers of IEC-6 by silicon rubber-tipped steel rods and various cytokines; transforming growth factor alpha (TGF-alpha), transforming growth factor beta1 (TGF-beta1), keratinocyte growth factor (KGF), and HGF, were added. We photographed the repaired monolayers every 24 h and calculated the ratios of areas not covered by cells to initial areas. Cell proliferation with TGF-alpha, TGF-beta, KGF, or HGF was examined in terms of [3H]-thymidine uptake. Finally, we determined c-met (the HGF receptor) mRNA in the IEC-6 cells by Northern blot hybridization. HGF was the most potent of the cytokines in accelerating repair of the damaged monolayer of IEC-6. HGF was also 1.34 times more effective than control the medium for inducing cell proliferation of IEC-6. By Northern blot hybridization, three bands of mRNA bound to c-met cDNA. These results suggest that HGF is important in the repair of the small intestine.

Constitutive association of EGF receptor with the CrkII-23 mutant that inhibits transformation of NRK cells by EGF and TGF-beta

Crk belongs to the adapter proteins that participate in many signalling pathways from cell surface receptors. We have characterised the CrkII-23 mutant that inhibits the transformation of NRK cells induced by epidermal growth factor (EGF) and transforming growth factor (TGF)-beta. To study the biochemical difference, cDNAs of the wild-type CrkII and the CrkII-23 mutant were introduced stably into NIH 3T3 cells expressing EGF receptor (EGFR). Both CrkII and CrkII-23 were phosphorylated on tyrosine upon EGF simulation with similar time course and dose dependency. Whereas the wild-type CrkII bound to EGFR only after EGF stimulation, CrkII-23 bound to EGFR from before stimulation. Mutation in the Src homology (SH) 2 or amino-terminal SH3 domain did not abolish the binding of CrkII-23 to EGFR in the quiescent cells, suggesting that the binding is mediated by a novel mechanism. These CrkII-23-derived mutants, however, did not suppress transformation of NRK cells by EGF and TGF-beta. Hence, both the SH2 and amino-terminal SH3 domains are required to inhibit transformation of NRK cells. These results suggest that persistent signalling from CrkII-23 bound to EGFR suppresses transformation by EGF and TGF-beta in NRK23 cells.

[The intrarenal distribution of prostaglandin E2 and thromboxane A2 in the rat with unilateral ureteral obstruction or unilateral nephrectomy]

BACKGROUND

We evaluated the intrarenal distribution of prostaglandin E2 (PGE2) and thromboxane B2 (TxB2) on the rats that underwent unilateral ureteral obstruction (UUO), unilateral nephrectomy (UNX) or sham operation.

METHODS

Male Sprague-Dawley rats were divided into three groups; left ureteral obstruction (UUO), left nephrectomy (UNX) and sham-operation (Control). They were sacrificed at 1, 3, 6, 12, 24 hours and Day 2, Day 3, Day 5, Day 7 and Day 9 after surgery. Intrarenal distribution of eicosanoids were immunohistochemically detected on both kidneys of UUO rats, and on right kidneys of UNX and Control rats.

RESULTS

PGE2: In the obstructed kidneys, immunostained PGE2 increased in medullary interstitium at one hour to 6 hours, and in glomeruli and cortical interstitium at 6 hours. An increase of immunostained PGE2 was observed again in cortical interstitium at Day 3 to 5, and in medullary interstitium at Day 2 to 5. In the intact opposite kidneys, expression of immunostained PGE2 increased in glomeruli at Day 5 to 7, and in medullary interstitium at Day 3 to 5. In UNX, immunostained PGE2 increased in the medullary interstitium of the remnant kidneys at 3 hours and Day 3 to 7. On the other hand, an increase of immunostained PGE2 observed in glomeruli and cortical interstitium of these kidneys at Day 5 to 7. TxB2: In the obstructed kidneys, immunostained TxB2 increased in glomeruli and cortical interstitium at 6 hours, and in medullary interstitium at 3 to 12 hours. Predominant expression of TxB2 was observed in medullary interstitium at 3 hours compared to PGE2. We also observed an increase of immunostained TxB2 in cortical interstitium at Day 3 to 5, and in medullary interstitium at Day 2 to 5. In the intact opposite kidneys, immunostained TxB2 increased in medullary interstitium at 3 hours and Day 3. In the remnant kidneys of UNX, an increase of immunostained TxB2 was demonstrated in glomeruli at 6 hours and Day 7, and in medullary interstitium at 3 to 6 hours and Day 3 to 7.

CONCLUSION

In the obstructed kidneys, imbalance between PGE2 and TxA2 may contribute to the progression of renal injuries. The fact that expression patterns of these eicosanoids in the opposite kidneys of UUO different from that of the remnant kidneys of UNK, even though both were similarly associated with functional loss of contralateral kidneys, suggested that the opposite kidneys of UUO were affected by any additional factors different from that responsible for the remnant kidneys of UNK.

A carrier for clinical use of recombinant human BMP-2: dehydrothermally cross-linked composite of fibrillar and denatured atelocollagen sponge

The clinical applicability of a dehydrothermally cross-linked composite of fibrillar and denatured atelocollagen sponge (DCFD-AS), as a carrier of recombinant human bone morphogenetic protein-2 (rhBMP-2) was evaluated in the rat subcutaneous pouch. After four weeks, DCFD-AS with rhBMP-2 formed compact bone, without undergoing significant changes in shape and size, by means of intramembranous ossification. The ultimate size, shape and location of induced new bone was accurately controlled by the carrier. Low antigenicity of soluble atelocollagen, cross-linking without chemicals, the combination of gelatin with fibrillar collagen, and the spongy structure probably all contributed to new bone formation through intramembranous ossification without inducing an inflammatory response. Atelocollagen sponge is easily sterilized, can be stored at room temperature, and can act as a rhBMP-2 carrier without the need for complex procedures.