Mouse hepatocyte growth factor activator inhibitor type 1 (HAI-1) and type 2 (HAI-2)/placental bikunin genes and their promoters

Hepatocyte growth factor (HGF) activator inhibitor type 1 (HAI-1) and type 2 (HAI-2) were recently discovered as specific inhibitors of HGF activator. Each of them contains two Kunitz-type serine protease inhibitor domains and a transmembrane domain, so that their overall structures are similar to each other. In this study, mouse genes encoding HAI-1 and HAI-2 were cloned by screening of a mouse genomic bacterial artificial chromosome library and by polymerase chain reaction of mouse genomic DNA, respectively. The genes (mHAI-1 and mHAI-2) were defined to consist of 11 and eight exons spanning 11 kbp and 9.5 kbp, respectively. Neither a TATA nor CAAT box was found in 5'-flanking regions of both genes and no apparent homologous portion was observed between mHAI-1 and mHAI-2 promoter regions. Promoter assay of mHAI-1 and human HAI-1 revealed that the potential binding sites of a complex of Egr-1-3 and Sp1, which was well-conserved between human (-42 to -58) and mouse (-44 to -57), might be a key portion of its transcriptional regulation to function as not only house-keeping but also early responsive genes.

Pericellular activation of hepatocyte growth factor/scatter factor (HGF/SF) in colorectal carcinomas: roles of HGF activator (HGFA) and HGFA inhibitor type 1 (HAI-1)

Activation of hepatocyte growth factor/scatter factor (HGF/SF) is a critical limiting step in the HGF/SF-induced signaling pathway mediated by MET receptor tyrosine kinase. Although HGF/SF-MET signaling could have potentially important roles in the invasive growth of tumors and tumor angiogenesis, little is known about the regulation of HGF/SF activation in the tumor tissues. This activation occurs in the extracellular milieu caused by proteolytic cleavage at the bond between Arg194-Val195 in the single-chain HGF precursor to generate the active two-chain heterodimeric form. Here we show that activation of HGF/SF is significantly enhanced in colorectal carcinoma tissues compared with normal colorectal mucosa, and HGF activator (HGFA), a recently identified factor XII-like serine proteinase, is critically involved in this process. Furthermore, we also show that HGF activator inhibitor type 1 (HAI-1) should have an important regulatory role in the pericellular activation of HGF/SF having diverse roles acting as a cell surface specific inhibitor of active HGFA and a reservoir of this enzyme on the cell surface. The latter property might paradoxically ensure the concentrated pericellular HGFA activity in certain cellular conditions in which shedding of HAI-1/HGFA complex from the plasma membrane is upregulated.

Simultaneous up-regulation of urokinase-type plasminogen activator (uPA) and uPA receptor by hepatocyte growth factor/scatter factor in human glioma cells

Several lines of evidence indicate that hepatocyte growth factor/scatter factor (HGF/SF) and its receptor, c-Met, may play an important role in progression of human glioma. In this study, effects of HGF/SF on urokinase- type plasminogen activator (uPA)-mediated proteolysis network were examined in c-Met-positive human glioma cell lines. Treatment of the glioma cells with various concentrations of HGF/SF resulted in an enhanced secretion of uPA proteins accompanying increased transcription of uPA mRNA in a dose dependent fashion. The levels of uPA receptor (uPAR) mRNAs were also elevated simultaneously upon HGF/SF stimulation, and the cell-surface associated uPA activity was also elevated by the treatment. Since concomitant expression of HGF and its receptor c-Met are frequently observed in malignant gliomas, these results suggest that HGF/SF participates in invasive process of malignant glioma cells not only by its motility-stimulating activity but also through enhanced degradation of the extracellular matrix induced by autocrine activation of uPA proteolysis network.

[Small cell carcinoma of the prostate: a case report]

A 81-year-old man was admitted to our department with the chief complaints of pollakisuria and difficulty in voiding. He presented with increased serum PSA level (over 100 ng/ml). We performed biopsy of the prostate and found a moderately differentiated adenocarcinoma. Various urological examinations showed metastases to paraaortic lymph nodes and systemic bones. He was started-on hormonal therapy. Nine months from the start of hormonal therapy, this therapy was effective and the serum PSA level was decreased to 14 ng/ml. Thereafter, the serum PSA level and the tumor volume were increased and he died 29 months from the start of treatment. The autopsy revealed small cell carcinoma with adenocarcinoma of the prostate.

Hepatocyte growth factor activator inhibitor type 1 is a specific cell surface binding protein of hepatocyte growth factor activator (HGFA) and regulates HGFA activity in the pericellular microenvironment

Hepatocyte growth factor activator (HGFA) is responsible for proteolytic activation of the precursor form of hepatocyte growth factor in injured tissues. To date, two specific inhibitors of HGFA have been identified, namely HGFA inhibitor type 1 (HAI-1) and type 2 (HAI-2)/placental bikunin (PB). Both inhibitors are first synthesized as integral membrane proteins having two Kunitz domains and a transmembrane domain, and are subsequently released from cell surface by shedding. Here we show that an active form of HGFA is specifically complexed with membrane-form HAI-1, but not with HAI-2/PB, on the surface of epithelial cells expressing both inhibitors. This binding required the enzyme activity of HGFA. The selective binding of HGFA to the cell surface HAI-1 was further confirmed in an engineered system using Chinese hamster ovary cells, in which only the cells expressing HAI-1 retained exogenous HGFA. The binding of HGFA to HAI-1 was reversible, and no irreversible modifications affecting the enzyme activity occurred during the binding. Importantly, HAI-1 and the HGFA.HAI-1 complex were quickly released from the cell surface by treatment with phorbol 12-myristate 13-acetate or interleukin 1beta accompanying the generation of 58-kDa fragments of HAI-1, which are less potent against HGFA, as well as significant recovery of HGFA activity in the culture supernatant. This regulated shedding was completely inhibited by BB3103, a synthetic zinc-metalloproteinase inhibitor. We conclude that HAI-1 is not only an inhibitor but also a specific acceptor of active HGFA, acting as a reservoir of this enzyme on the cell surface. The latter property appears to ensure the concentrated pericellular HGFA activity in certain cellular conditions, such as tissue injury and inflammation, via the up-regulated shedding of HGFA.HAI-1 complex. These findings shed light on a novel function of the integral membrane Kunitz-type inhibitor in the regulation of pericellular proteinase activity.

Localization of hepatocyte growth factor activator inhibitor type 1 in Langhans' cells of human placenta

Activation of hepatocyte growth factor (HGF) is a crucial limiting step in HGF-induced signaling pathway. The HGF activator inhibitor type 1 (HAI-1) was identified as a potent inhibitor of HGF activator (HGFA), a serine proteinase that is responsible for the activation of HGF in vivo. HAI-1 is an integral membrane Kunitz-type serine proteinase inhibitor, and its mRNA has been reported to be most abundant in the placenta. In this report, specific antibody to HAI-1 was used in an immunohistochemical procedure to determine the localization of HAI-I in human placenta. HAI-1 was expressed in cytotrophoblasts (Langhans' cells) of the double-layered trophoblastic epithelium of chorionic villi tissue, and syncytiotrophoblasts were almost negative. On the other hand, extravillous trophoblasts of cytotrophoblastic columns showed markedly decreased immunoreactivity, and those infiltrating into the superficial decidua membrane of early placenta were hardly stainable. The amnionic epithelial cells were also immunostained intensely. The presence of HAI-1 mRNA was also confirmed in a cultured human cytotrophoblastic cell line. In addition to HAI-1, low but distinct expression of HGFA mRNA was observed in the placenta tissue and cultured cytotrophoblasts by using a sensitive RT-PCR method. Since HGF plays an essential role in the placenta development, expression of HAI-1 and HGFA may have an important regulatory role in the placenta. The localization of HAI-I in the proliferating trophoblastic stem cells (Langhans' cells), but not in syncytiotrophoblasts and extravillous trophoblasts, suggest a possible role of HAI-1 in the proliferation of trophoblasts.

Activation of hepatocyte growth factor/scatter factor in colorectal carcinoma

Activation of hepatocyte growth factor/scatter factor (HGF/SF) in the extracellular milieu is a critical limiting step in the HGF/SF-induced signaling pathway mediated by Met receptor tyrosine kinase, which has potentially important roles in tumor biology and progression. However, little is known concerning the regulation of HGF/SF activation in tumors. Immunoblot analysis revealed that the activation of HGF/SF was enhanced significantly in colorectal carcinoma tissues compared with the corresponding normal mucosa. Serum-free conditioned media of cultured human colorectal carcinoma cell lines contained HGF/SF-activating activity, and the addition of a single-chain precursor form of HGF/SF to the serum-free culture of these cells resulted in HGF/SF-dependent modulation of cellular phenotypes, such as increased scattering and enhanced secretion of vascular endothelial growth factor. This processing activity was enhanced by thrombin treatment but was inhibited significantly by a neutralizing antibody against HGF activator (HGFA), a factor XIIa-like serine proteinase believed to be expressed mainly in the liver. The activity was also inhibited by recombinant HGFA inhibitor type 1 (HAI-1). The presence of HGFA mRNA and secretion of HGFA protein were confirmed in the cell lines. Therefore, extrahepatic expression of HGFA in the colorectal carcinoma cells could be responsible for the single-chain HGF/SF-processing activity of the cells. We examined the expression of HGFA and HAI-1 in human colorectal mucosa and adenoma-carcinoma sequence. Immunohistochemically, HGFA was stained weakly in the normal enterocytes, and immunoreactivity was increased modestly in the neoplastic differentiation. The subcellular localization of HGFA immunoreactivity was altered in carcinoma cells showing basal or cell-stroma interface staining patterns, compared with normal and adenoma cells with a supranuclear or apical staining pattern. In contrast to HGFA, the expression of HAI-1 decreased significantly in carcinoma cells relative to the adjacent normal or adenoma cells, indicating that the net balance between HGFA and HAI-1 shifts in favor of HGFA in carcinomas. In fact, pro-HGFA and the active form of HGFA proteins increased in carcinoma tissue compared with the corresponding normal mucosa. It was concluded that HGFA is expressed in colorectal mucosa and tumors and could be involved in the activation of HGF/SF in colorectal carcinomas. Therefore, the balance between HGFA and HAI-1 could play an important role in the regulation of HGF/SF activity in colorectal carcinomas.

Genomic structure and chromosomal localization of the human hepatocyte growth factor activator inhibitor type 1 and 2 genes

Hepatocyte growth factor activator inhibitor type 1 (HAI-1) and type 2 (HAI-2) are recently discovered Kunitz-type serine protease inhibitors which can be purified and cloned from human stomach cancer cell line MKN45 as specific inhibitors against hepatocyte growth factor activator (HGFA). HAI-2 was identical with the protein originally reported as placental bikunin. Both proteins contain two Kunitz inhibitor domains (KDs), of which the first domain (KD1) is mainly responsible for the inhibitory activity against HGFA, and are expressed ubiquitously in various tissues. In this study, we cloned the genes coding for these two structurally similar proteins by screening of human genomic bacterial artificial chromosome (BAC) library and their genomic structures were compared. HAI-1 and -2 genes consist of 11 and 8 exons spanning 12 kbp and 12.5 kbp, respectively. Three exons were inserted between KD1 and KD2 of each gene, of which the middle one was the low-density lipoprotein (LDL) receptor-like domain (HAI-1) and the testis specific exon (HAI-2). Apparently homologous regions between HAI-1 and -2 were not found in 5'-flanking region and neither TATA nor CAAT box was present. The genes were mapped to chromosome 15q15 (HAI-1) and 19q13.11 (HAI-2). These results suggested that although HAI-1 and -2 genes might be derived from same ancestor gene, they acquired distinctive in vivo roles during their evolution.

Carcinoembryonic antigen and carbohydrate antigen 19-9-producing adenocarcinoma of the prostate: report of an autopsy case

Prostate-specific antigen (PSA) and prostatic acid phosphatase (PAP) are well known as specific tumor markers of prostate cancer, but carcinoembryonic antigen (CEA)- and carbohydrate antigen 19-9 (CA19-9)-producing adenocarcinoma originating in the prostate is rare. We report here a case of prostatic adenocarcinoma positive for these 4 tumor markers in a 50-year-old man who had initially complained about chest pain due to metastatic bone tumor. In spite of the extensive treatment involving hormone and radiation therapy, the patient died of rapid tumor extension only 4 months after initial diagnosis. Autopsy revealed multiple metastases to the bone, liver, lungs and lymph nodes. Histologically, two types of adenocarcinoma were involved in both primary prostate and metastatic sites: one was a poorly differentiated adenocarcinoma positive for PSA and PAP but not CEA or CA19-9, and the other one was a less differentiated adenocarcinoma partially positive for CEA and CA19-9 but not for PSA or PAP. Based on this case and previous cases by review of the literature, CEA- and CA19-9-producing adenocarcinoma of the prostate was suggested to rapidly progress with multiple metastases and to show poor prognosis with strong resistance to any treatment.

Mouse hepatocyte growth factor activator gene: its expression not only in the liver but also in the gastrointestinal tract

A cDNA encoding mouse hepatocyte growth factor activator (HGFA) has been cloned by RT-PCR, based on the screening result from the database of expressed sequence tags. Subsequently, its gene was cloned from a mouse genomic bacterial artificial chromosome library using the cDNA as a probe. Sequencing analysis revealed that mouse HGFA protein deduced from the cDNA, similar to its human and rat counterparts, has two epidermal growth factor-like domains, type 1 and 2 fibronectin homology domains, a single kringle domain and a catalytic domain of serine proteinase, and the gene consists of 14 exon spanning approximately 7.5 kb. Interestingly, mouse HGFA mRNA was detected not only in the liver but also in the gastrointestinal tract by RNA blot analysis. Since hepatocyte growth factor (HGF) is up-regulated in the damaged gastrointestinal mucosa, our present data suggest that HGFA might activate proHGF directly in the gastrointestinal mucosa and play an important role in wound repair throughout the gastrointestinal tract.

Upregulation of HGF activator inhibitor type 1 but not type 2 along with regeneration of intestinal mucosa

Hepatocyte growth factor (HGF) activator inhibitor type 1 (HAI-1) and type 2 (HAI-2) are new Kunitz-type serine protease inhibitors that were recently purified and cloned from the human stomach cancer cell line MKN45 as specific inhibitors against HGF activator. Both proteins contain two Kunitz inhibitor domains and are expressed abundantly throughout the gastrointestinal tract, in addition to the placenta, pancreas, and kidney. In this study, to assess the possible roles of HAI-1 and HAI-2 in the intestinal mucosa, we examined the expression of HAI-1 and HAI-2 during regeneration of the intestinal mucosa. Immunohistochemical studies revealed that HAI-1 but not HAI-2 was detected more strongly in regenerative epithelium than in normal epithelium, although both proteins were detected throughout the human gastrointestinal tract. During the course of acetic acid-induced experimental colitis in an in vivo mouse model, HAI-1 but not HAI-2 was upregulated in the recovery phase, suggesting that HAI-1 but not HAI-2 is associated with the regeneration of damaged colonic mucosa. Upregulation of HAI-1 may serve to downregulate the proliferative response after initial activation of MET receptor by HGF/scatter factor after an injury.

Conserved expression of hepatocyte growth factor activator inhibitor type-2/placental bikunin in human colorectal carcinomas

Hepatocyte growth factor activator inhibitor type 2 (HAI-2) was recently identified as a potent inhibitor of hepatocyte growth factor activator. It was also independently reported as placental bikunin (PB) and as a protein over-expressed in pancreatic cancer. The expression of HAI-2/PB was analyzed in human normal colon mucosa, adenomas, and carcinomas. HAI-2/PB mRNA was consistently expressed in the colorectal mucosa. The expression was conserved in the neoplastic colorectal mucosa, and no relationship was found between HAI-2/PB mRNA levels and tumor stages. Moreover, 13 out of 14 colorectal carcinoma cell lines expressed HAI-2/PB mRNA. Immunohistochemically, HAI-2/PB proteins were predominantly stained beneath the apical surface of normal enterocytes. In tumor tissues, rather disarranged intracytoplasmic granular staining was observed. The HAI-2/PB immunoreactivity was well conserved in the colonic adenoma-carcinoma sequence, and this protein may have important unknown function in the intestinal mucosa.

Overexpression of intestinal trefoil factor in human colon carcinoma cells reduces cellular growth in vitro and in vivo

BACKGROUND & AIMS

Intestinal trefoil factor (ITF) has a role in gastrointestinal mucosal integrity and the repair of damaged mucosa. However, little is known about its role in tumors. To analyze the role of ITF in colon carcinomas, overexpression of the ITF gene in colon carcinoma cells was used.

METHODS

Human colon carcinoma cell lines LoVo and SW837, expressing no endogenous ITF, and WiDr expressing a low level of ITF were stably transfected with an expression vector harboring human ITF complementary DNA. The effects of ITF overexpression on in vitro growth, morphology in collagen gel, response to epidermal growth factor (EGF), mitogen-activated protein kinase (MAPK) activity, and growth in nude mice were assessed.

RESULTS

Overexpression of ITF in LoVo and SW837 resulted in significantly reduced growth in vitro and in vivo. In collagen gels, the ITF-expressing LoVo clones formed smaller, more dispersed colonies. EGF-induced phosphorylation of MAPKs was modestly reduced in the ITF-expressing clones. The growth of WiDr was modestly suppressed only in vivo by ITF overexpression.

CONCLUSIONS

Overexpression of ITF suppressed the growth of colon carcinoma cells. ITF may function as an inhibitory factor for the growth of colonic neoplasm.

[Acute renal failure due to over-infusion in a child with bilateral obstruction of the pyeloureteral junction]

A 2-year-old boy was hospitalized with the chief complaint of oliguria and dyspnea. Bilateral hydronephrosis and obstruction of the pyeloureteral junction were detected by ultrasonography. Pulmonary edema was also found on chest radiographs. The clinical diagnosis was acute post renal failure due to bilateral pyeloureteral obstruction and pulmonary edema due to overtransfusion. After we performed bilateral percutaneous nephrostomy, the patient recovered from renal failure and pulmonary edema. Both nephrostomies were removed after we confirmed a non-obstructing pattern using the Whitaker test.

Solitary fibrous tumor of the spinal nerve rootlet: case report and literature survey

Solitary fibrous tumor (SFT) is a rare tumor that arises most commonly in the pleura. Recent evidence indicated that it is a tumor that originates from mesenchymal, probably fibroblastic, cells and is not restricted to the pleura. This report presents a case of primary SFT occurring as a dumbbell-shaped tumor of the cervical spine (C4/5) in a 46-year-old Japanese female, probably originating from the spinal rootlet. The tumor was predominantly extradural, loosely attached to the dura mater, with a small intradural extramedullary part attached to the C5 anterior and posterior rootlets. Histologically, the tumor was predominantly composed of a haphazard proliferation of spindle cells separated by abundant collagen. Immunohistochemically, the cells were strongly positive for CD34, bcl-2 and vimentin, but were negative for S-100 protein, neuron specific enolase, cytokeratin and epithelial membrane antigen. The present case and review of the literature strongly suggest that SFT is an entity that should be considered in the differential diagnosis of tumors of the cerebrospinal region.

Regulation of matrix metalloproteinase-2 (MMP-2) by hepatocyte growth factor/scatter factor (HGF/SF) in human glioma cells: HGF/SF enhances MMP-2 expression and activation accompanying up-regulation of membrane type-1 MMP

Hepatocyte growth factor/scatter factor (HGF/SF) contributes to the malignant progression of human gliomas. We investigated the effect of HGF/SF on matrix metalloproteinase-2 (MMP-2), membrane type 1 matrix metalloproteinase (MT1-MMP) and tissue inhibitors of metalloproteinases (TIMPs), expressions of c-Met/HGF receptor-positive human glioblastoma cells. Treatment of U251 human glioblastoma cells with HGF/SF resulted in enhanced secretion of MMP-2 with an increased level of the active form. This was accompanied by enhanced expression (2.5-fold) of mRNA specific for MMP-2. The stimulatory effect of HGF/SF on MMP-2 expression did not occur in the presence of herbimycin A, a protein tyrosine kinase inhibitor. MT1 -MMP, a cell-surface activator of proMMP-2, was also up-regulated by HGF/SF in a dose-dependent manner. By contrast, the level of TIMP- 1 mRNAs was not altered significantly and that of TIMP-2 was reduced mildly by the HGF/SF treatment, suggesting that HGF/SF may eventually modulate a balance between MMP-2 and TIMPs in favor of the proteinase activity in the glioma cell microenvironment. HGF/SF also stimulated MMP-2 expression of other glioblastoma cell lines. Since glioblastomas frequently co-express HGF/SF and its receptor, our results suggest that HGF/SF might contribute to the invasiveness of glioblastoma cells through autocrine induction of MMP-2 expression and activation.

Regulation of matrix metalloproteinase-2 (MMP-2) by hepatocyte growth factor/scatter factor (HGF/SF) in human glioma cells: HGF/SF enhances MMP-2 expression and activation accompanying up-regulation of membrane type-1 MMP

Hepatocyte growth factor/scatter factor (HGF/SF) contributes to the malignant progression of human gliomas. We investigated the effect of HGF/SF on matrix metalloproteinase-2 (MMP-2), membrane type 1 matrix metalloproteinase (MT1-MMP) and tissue inhibitors of metalloproteinases (TIMPs), expressions of c-Met/HGF receptor-positive human glioblastoma cells. Treatment of U251 human glioblastoma cells with HGF/SF resulted in enhanced secretion of MMP-2 with an increased level of the active form. This was accompanied by enhanced expression (2.5-fold) of mRNA specific for MMP-2. The stimulatory effect of HGF/SF on MMP-2 expression did not occur in the presence of herbimycin A, a protein tyrosine kinase inhibitor. MT1 -MMP, a cell-surface activator of proMMP-2, was also up-regulated by HGF/SF in a dose-dependent manner. By contrast, the level of TIMP- 1 mRNAs was not altered significantly and that of TIMP-2 was reduced mildly by the HGF/SF treatment, suggesting that HGF/SF may eventually modulate a balance between MMP-2 and TIMPs in favor of the proteinase activity in the glioma cell microenvironment. HGF/SF also stimulated MMP-2 expression of other glioblastoma cell lines. Since glioblastomas frequently co-express HGF/SF and its receptor, our results suggest that HGF/SF might contribute to the invasiveness of glioblastoma cells through autocrine induction of MMP-2 expression and activation.

Hepatocyte growth factor activator inhibitor type 2 lacking the first Kunitz-type serine proteinase inhibitor domain is a predominant product in mouse but not in human

Hepatocyte growth factor activator inhibitor type 2 (HAI-2) is a new Kunitz-type serine protease inhibitor, which is purified and cloned from human stomach cancer cell line MKN45. The mature HAI-2 protein contains two Kunitz domains and the first domain is mainly responsible for the inhibitory activity against hepatocyte growth factor activator (HGFA). In this study, we identified the mouse homolog of HAI-2 (mHAI-2) by screening the data base of public expressed sequence tag (dbEST). In addition to a full-length cDNA corresponding to human HAI-2, a shorter size of mHAI-2 cDNA was obtained from mouse kidney by reverse-transcription polymerase chain reaction (RT-PCR). Sequence analysis of this shorter cDNA revealed that the region encoding the first Kunitz domain was completely deleted. Analysis of mouse genomic DNA showed that the deleted cDNA was generated by an alternative splicing mechanism. Surprisingly, the spliced form lacking the first Kunitz domain was a predominant transcript in all tissues of mice tested but not in those of human as assessed by RT-PCR analysis. This phenomenon is also confirmed by Western blot analysis using the specific antiserum against human HAI-2 protein. These results suggest that most of HAI-2 expressed in various tissues of mice may be unable to inhibit HGFA efficiently.

Retroperitoneal bronchogenic cyst: report of a case and literature review

A large cystic mass was found in the subdiaphragmatic region of a 46-year-old woman who had complained of continuous pain in the left flank . The cyst was located in the retroperitoneum just below the diaphragm and was adhered to the diaphragmatic skeletal muscle and abdominal aorta, but was separate from the spleen, pancreas, left adrenal gland and left kidney. The surgically resected cyst measured 8 x 8 x 7 cm and was filled with protein-rich fluid, which contained amylase and embryonal proteins such as carcinoembryonic antigen, CA125 and CA19-9. Histologically, the cyst wall was composed of a fibrovascular connective tissue containing thin smooth muscle layers and mucus-secreting glands and was lined by a ciliated pseudostratified or tall columnar epithelium without dysplastic changes. Thus, a diagnosis of bronchogenic cyst, which is usually discovered in the posterior part of the mediastinum, was made. A rare case of bronchogenic cyst and a literature review is presented.

Up-regulation of vascular endothelial growth factor induced by hepatocyte growth factor/scatter factor stimulation in human glioma cells

Recent findings suggest that hepatocyte growth factor/scatter factor (HGF/SF) contributes to the malignant progression of human gliomas. We investigated the effect of HGF/SF on vascular endothelial growth factor (VEGF) expression of c-Met/HGF receptor-positive human glioma cell lines. Treatment of the glioma cells with various concentrations of HGF/SF resulted in an enhanced secretion of VEGF proteins accompanying increased transcription of VEGF mRNA in a dose-dependent fashion. Since malignant gliomas frequently co-express HGF/SF and its receptor, these results suggest that HGF/SF could act as an indirect angiogenic factor through autocrine induction of VEGF expression and secretion in malignant gliomas.

[Indication for surgery of pediatric testicular and funicular hydroceles in view of natural course]

PURPOSE

The purpose of this study is to confirm the definite indication for surgery of pediatric testicular and funicular hydroceles in view of natural course.

METHODS

During the period from 1978 to 1994, we encountered 160 hydroceles in 149 pediatric patients. Patients ages ranged from 5 days after birth to 13 years and the mean follow-up periods was 4.7 years. We investigated the indication for surgery of pediatric hydroceles in six points of view: value of an aspiration of hydroceles, of what testicular or funicular or both, communication, size, age and testicular development.

RESULTS

Nevertheless, of 160 hydroceles, 66 (41%) were performed an aspiration of hydroceles, the aspiration of hydrocele was ineffective in the majority of patients. Common hydroceles in neonates and infants required no specific treatment, as the majority of hydrocele resolve spontaneously, however surgical treatment was required for a communicating large hydrocele that had been often attacked by aspiration and appeared at older age. Funicular hydroceles were more difficult to spontaneous healing. Ipsilateral testis manifests a well-developed comparing control material.

CONCLUSION

The indication for surgery of pediatric hydroceles were as follows: 1) hydroceles complicated by a inguinal hernia or cryptorchidism, 2) hydroceles appeared at older age and not resolved during 2-3 years over, 3) giant communicating funicular and testicular hydroceles present with an/hindrance for daily life.

Inhibition by iota-carrageenan of the spread of murine cytomegalovirus from the peritoneal cavity to the blood plasma

The mechanism of iota-carrageenan (i-CAR)-induced protection against murine cytomegalovirus (MCMV) infection of mice was analysed. The virus titres in the target organs on the fourth day correlated with that in the plasma at 1 h after intraperitoneal inoculation of MCMV, irrespective of i-CAR treatment. Pretreatment of mice with i-CAR induced infiltration of polymorphonuclear neutrophils into the peritoneal cavity and inhibition of viral spread from the peritoneal cavity to the plasma. Although the direct relationship of these two phenomena was unclear, the inhibition by i-CAR of viral spread resulted in protection against MCMV infection of mice.

[A case of intracranial malignant melanoma with increased uptake of IMP in SPECT]

A patient with intracranial malignant melanoma was assessed by 123I-IMP SPECT. Early image, performed 30 minutes after intravenous injection of 111 MBq 123I-IMP, demonstrated an accumulation similar to normal gray matter-defect. Delayed image, performed 4-hour after injection, demonstrated increased accumulation of 123I-IMP. 123I-IMP SPECT, especially delayed scan, was valuable for qualitative diagnosis of intracranial malignant melanoma.

Protective effect of MDP-Lys(L18), a synthetic derivative of muramyldipeptide, on murine cytomegalovirus infection

The host-mediated antiviral effect of N alpha-(N-acetylmuramyl-L-alanyl-D-isoglutaminyl)-N epsilon-stearoyl-L-lysine [MDP-Lys(L18)] was evaluated in mice against murine cytomegalovirus (MCMV) infection. Mice treated with 800 micrograms of MDP-Lys(L18) on day 2 before the virus challenge survived systemic lethal infection. The protective effect of MDP-Lys(L18) was evidenced by an increase in plaque-forming units per LD50 and a decrease in virus titers in the target organs. No significant difference in the serum interferon level and 2',5'-oligoadenylate synthetase activity was observed among the mice treated with test compounds or phosphate-buffered saline, thought they were higher in MCMV-infected mice than in mock-infected mice. The natural killer (NK) activity was augmented remarkably in the mice treated with MDP-Lys(L18) or its original component, muramyldipeptide (MDP). MDP-Lys(L18) showed neither virocidal nor virostatic activity on MCMV in vitro. Thus, MDP-Lys(L18)-induced resistance against MCMV infection seems to be host-mediated. The MDP-Lys(L18)-induced resistance was not abrogated by the treatment with anti-asialo GM1 serum. The NK activity augmented by MDP-Lys(L18) may contribute to some part of the protective effect, though the augmentation of the NK activity alone did not correlate completely with the protective effect of MDP-Lys(L18). In addition, no difference was observed in anti-MCMV activity among peritoneal exudate cells from mice treated with MDP-Lys(L18), MDP or phosphate-buffered saline. Therefore, another host-mediated factor(s) may also participate in the antiviral effect of MDP-Lys(L18).