Copper-ion-catalyzed vitreous liquefaction in vivo

To investigate copper-ion (Cu2+)-catalyzed vitreous liquefaction in vivo, Cu2+ solution (10 mumol) was injected into the vitreous cavity of rabbits. At 24 h after the injection, the gel and liquid vitreous were weighed, and the percent of vitreous liquefaction was calculated. Cu2+ injection resulted in liquefaction of 58% of the vitreous, although control eyes had 12% liquefaction (p < 0.1). The vitreous liquefaction was more pronounced in the presence of exogenous ascorbic acid. However, the addition of mannitol, a hydroxyl-radical-specific scavenger, significantly suppressed the Cu(2+)-catalyzed vitreous liquefaction. The free radicals generated by the Cu(2+)-catalyzed oxidation system may cause vitreous liquefaction in vivo.

Messenger RNA expression of the genes encoding receptors for bone morphogenetic protein (BMP) and transforming growth factor-β (TGF-β) in the cells from the posterior longitudinal ligament in cervical spine

Posterior longitudinal ligament (PLL) in cervical spine is one of the sites of ossification in idiopathic hyperostotic diseases. Although the mechanism of the pathological triggering of the disease has not yet been clarified, the cells in PLL have been reported to express osteotropic cytokines such as BMP-2 and TGF-β. However, it has not been known whether the cells in PLL express receptors for these cytokines. We examined the expression of the messenger RNAs of the genes encoding receptors for BMP-2/4 and TGF-β in the PLL cells. Tissues from three OPLL (ossification of the posterior longitudinal ligament) patients who underwent anterior decompression surgery with removal of the ossified PLL were dissected microscopically and were subjected to explant cultures; the cells outgrown from the explants were examined. Type I BMP receptor (BMPR) mRNA was expressed at moderate levels in the cells derived from both ossifying PLL tissues as well as nonossifying adjacent fibrous tissues. Type II TGF-β receptor (TβR) mRNA and α1(I) collagen mRNA were also constitutively expressed in these PLL cells from either regions. Treatment with BMP-2 enhanced the expression of BMPR mRNA in five out of ten of the cell cultures, suggesting that functional BMP receptors were expressed in at least a part of the PLL cells. The BMP-2 effect on BMPR was specific since no such enhancement was observed with regard to the levels of TβR mRNA in all of the ten cultures. These results indicated for the first time that mRNAs of the genes encoding receptors for BMP-2/4 and TGF-β were expressed in the cells derived from human PLL cells.

[Suitable measure for medicines resulting from pharmacist-visit and assistance for a good treatment]

Our medication team, consists doctors, nurses, pharmacists, and other staffs, made an effort to satisfy our patients with medical treatment. We especially tried to guarantee patient rights. Pharmacists visited patients in September 1995, seeking to inform every patient about effects and side effects of medicines using the "Medicine Information Sheet" with samples. As a result, in one case now under treatment by medicine, he no longer needs it. Then, our medication team had a conference and his doctor changed his prescription. In another case, we found a symptom suspected to be a side effect of a medicine. We asked his doctor about it, and he stopped the medicine in question. His medical condition then became better. This resulted in a "suitable amount" of medicine. We are confident that this is also necessary for every patient under treatment at home, when a pharmacist visits his or her home and informs them about the effects and side effects of medicines, and assists them to assure good treatment.

BMP-2/-4 mediate programmed cell death in chicken limb buds

During limb development, the mesenchymal cells in restricted areas of limb bud, anterior necrotic zone, posterior necrotic zone, opaque zone and interdigital necrotic zones, are eliminated by programmed cell death. The transcripts of bone morphogenetic protein (Bmp)-2 and −4 were first detected in the areas where cell death was observed, then showed overlapping expression with the programmed cell death zones except the opaque zone. To investigate the function of BMP-2 and BMP-4 during limb pattern formation, the dominant negative form of BMP receptor was overexpressed in chick leg bud via a replication-competent retrovirus to block the endogenous BMP-2/-4 signaling pathway. This resulted in excess web formation at the anterior and posterior regions of limb buds in addition to marked suppression of the regression of webbing at the interdigital regions. Significant reductions in the number of apoptotic cells in these three necrotic zones were found in the limb buds which received the virus carrying dominant negative BMP receptor. This indicates that extra tissue formation is due to suppression of programmed cell death in the three necrotic zones. Moreover, BMP-2/-4 protein induced apoptosis of mesenchymal cells isolated from the interdigital region in vitro. Other TGFbeta family proteins as TGFbeta1 and Activin did not show this effect. These results suggest that BMP-2 and BMP-4 are the apoptotic signal molecules of the programmed cell death process in the chick limb buds.

Developmental changes in alpha 1-adrenergic receptors, IP3 responses, and NE-induced contraction in cerebral arteries

Cerebral arteries show significant developmental and artery-specific changes in noradrenergic-mediated contraction. To test the hypothesis that these changes result from differences in the density of alpha 1-adrenergic receptors (alpha 1-ARs) and/or norepinephrine (NE)-induced inositol 1,4,5-trisphosphate [Ins(1,4,5)P3,IP3] synthesis, we quantified these variables and the NE-induced contraction in the common carotid artery (Com) and main branch cerebral arteries (MBC) from term fetal (approximately 140 gestational day) and newborn (2- to 5-day) sheep and compared them with adult values. In fetal and newborn Com, maximal contractions to NE (percent K+ maximum response) were 132 +/- 14 and 118 +/- 9%, respectively (adult = 92 +/- 7%). For fetal and newborn middle cerebral artery, these values were 34 +/- 10 and 43 +/- 7%, respectively (adult = 24 +/- 7%). alpha 1-AR density values in Com of fetal and newborn sheep were 113 +/- 18 and 106 +/- 4 fmol/mg protein, respectively (adult = 54 +/- 3 fmol/mg protein). For the MBC, density values were 47 +/- 2 and 24 +/- 3 fmol/mg protein, respectively (adult = 23 +/- 3 fmol/protein). In term fetal and newborn MBC, NE produced dose-dependent increases in Ins(1,4,5)P3, the maximal increases above basal values being 245 +/- 40 and 189 +/- 16%, respectively (adult = 254 +/- 35%). Neither fetus nor newborn Com showed significant Ins(1,4,5)P3 responses to NE. We concluded that in fetal and newborn Com and MBC, alpha 1-AR density and NE-induced Ins(1,4,5)P3 response varied as a function of developmental age and specific vessel. However, these variations did not correlate with NE-induced maximum contraction. Thus we reject the hypothesis that age-dependent and vessel-specific differences of cerebral artery adrenergic-mediated contraction are a function of alpha 1-AR density or Ins(1,4,5)P3 response. Rather, the differences would appear to result from other factors such as non-Ins(1,4,5)P3-mediated calcium activation and/or sensitivity to Ins(1,4,5)P3. The studies also suggest considerable potential for maturational modulation of pharmacomechanical coupling and homeostatic regulation of cerebrovascular tone.

The role of BMP-4 and GATA-2 in the induction and differentiation of hematopoietic mesoderm in Xenopus laevis

Vertebrate embryonic blood formation is regulated by factors that participate in dorsal-ventral patterning and mesoderm induction. The GATA-binding transcription factors are required for normal hematopoiesis and are expressed during gastrulation when ventral mesoderm (VM) is induced to form blood. Based on the recent demonstration that bone morphogenetic protein (BMP-4) is a potent ventralizing factor and inducer of hematopoietic tissue, we hypothesized that GATA-2 could be induced or activated by BMP-4. Here we demonstrate that BMP-4 can stimulate GATA-2 expression, and that expression of a dominant negative BMP-4 receptor can suppress GATA-2 induction by BMP-4 in ventral mesoderm. Over-expression of GATA-2 in ventral mesoderm leads to increased globin production and forced expression of GATA-2 in primitive ectoderm adjacent to ventral mesoderm also stimulates globin expression. Our results suggest that BMP-4 and GATA-2 can function in two adjacent germ layers, mesoderm and ectoderm, to participate in blood cell formation during embryogenesis.

Assessment of the course and variations of the hepatic artery in bile duct cancer by intraductal ultrasonography

BACKGROUND

We evaluated the course and variations of the hepatic artery in bile duct cancer using intraductal ultrasonography (IDUS).

METHODS

IDUS was used to demonstrate the course of the hepatic artery preoperatively in 20 patients with extrahepatic bile duct cancer, and the image was compared with angiographic and surgical findings.

RESULTS

IDUS was able to assess tumor invasion to the main branch of the right hepatic artery in all cases. However, it demonstrated only three cases in the left hepatic artery and four cases in the proper hepatic artery. When the hepatic artery indicated re-entry or bifurcation on the IDUS image, the proximal portion of re-entry or bifurcation was established as the proper hepatic artery, but when it showed neither re-entry nor bifurcation it was established as the right hepatic artery.

CONCLUSIONS

IDUS demonstrated the main branch of the right hepatic artery in all cases, but was not useful for demonstration of the left and proper hepatic arteries. Correct assessment of re-entry and bifurcation was essential on IDUS images for making the distinction between the right hepatic artery and the proper hepatic artery.

[Progress and clinical usefulness of color Doppler method in diagnosing abdominal diseases]

We report the clinical usefulness of extracorporeal color Doppler ultrasonography (CDUS), color Doppler endoscopic ultrasonography (CDEUS), and recent progress in diagnosing abdominal diseases by the color Doppler method. CDUS has the advantage of being able to be performed repeatedly and noninvasively, it is thought to be useful for the evaluation of tumor vascularity and diagnosis of vascular tumor invasion and analysis of hemodynamics in abnormal vessels found in several abdominal diseases. CDEUS, which is performed under endoscopic ultrasonography (EUS), can evaluate the hemodynamics more minutely and visualize small vessels more clearly than conventional CDUS. Recent progress in the color Doppler method, such as US color angiography and the use of contrast agents is expected to lead to a higher resolution of visualization and easier detection of abdominal vessels.

Assessment of pancreatic parenchymal invasion by bile duct cancer using intraductal ultrasonography

BACKGROUND AND STUDY AIMS

This study was performed to clarify the diagnostic accuracy of intraductal ultrasonography (IDUS) in assessing pancreatic parenchymal invasion by bile duct cancer.

PATIENTS AND METHODS

Preoperative assessment of pancreatic parenchymal invasion was carried out by IDUS via a percutaneous tract or a transpapillary route in 18 patients with extrahepatic bile duct cancer. Various probes with diameters of 1.4, 2.0, 2.4, 2.6 and 3.2 mm, and frequencies of 7.5, 15, 20 and 30 MHz were used. All patients underwent angiography and endoscopic ultrasonography (EUS). In the first six cases, IDUS and EUS images were analyzed retrospectively without knowledge of the operative outcome or the results of other imaging tests. In the subsequent 12 cases, the IDUS und EUS images were prospectively reviewed prior to surgery. The diagnostic accuracy of IDUS was compared with angiography and EUS by means of a histopathological examination of the resected specimens.

RESULTS

The accuracy of IDUS, EUS, and angiography in assessing pancreatic parenchymal invasion was 100%, 78% and 61%, respectively. However, IDUS could not assess pancreatic capsular invasion. The accuracy of IDUS in assessing horizontal tumor extension to the intrapancreatic bile duct and to the hepatic side was 83% and 72%, respectively.

CONCLUSIONS

IDUS proved useful for assessing the extension of cancer invasion to the pancreatic parenchyma, but not to the pancreatic capsule or mucosal surface.

Diagnosis of gallbladder carcinoma with color Doppler ultrasonography

A 65-yr-old woman was referred to our department for evaluation of a gallbladder lesion detected at another institution, where she was diagnosed with chronic cholecystitis. Conventional ultrasonography revealed that the gallbladder lumen was filled with debris-like components, and the gallbladder wall was mildly thickened. Color Doppler ultrasonography revealed color signals in both the lesion and the gallbladder wall. These signals showed a high-speed pulsatile wave, and one of the visualized signals revealed a high-resistance index (1.0) on fast Fourier transform analysis. These findings were highly suggestive of malignancy. Surgery was performed, and histological examination of the resected specimen revealed carcinoma of the gallbladder. We conclude that color Doppler ultrasonography can be useful in the diagnosis of tumefactive gallbladder lesions.

BMP-4 mediates interacting signals between the neural tube and skin along the dorsal midline

BACKGROUND

The neural tube and its overlying tissues (skin and mesenchyme) interact along the dorsal midline during early development. This has been previously demonstrated experimentally in chicken embryos by the fact that the dorsal neural tube transplanted ectopically induced expression of Msx 2 in the adjacent tissues. It is important to identify the molecules responsible for these interactions.

RESULTS

We observed that BMP-4, a member of the TGFbeta-family, is expressed in the dorsal neural tube in a pattern closely correlated with that of Msx 2. In order to investigate whether BMP-4 mediates the signal between the neural tube and the skin/mesenchyme, BMP-4 was ectopically administered in ovo either by implantation of the recombinant protein or transplantation of COS cells producing BMP-4. Both manipulations resulted in ectopic induction of Msx 2 expression in the adjacent skin/mesenchyme. In addition, the activity of BMP-4 in inducing Msx 2 was counteracted by the floor plate.

CONCLUSION

These data suggest that BMP-4 positively mediates the signals from the neural tube to the adjacent tissues and that this signal may be an essential step for the establishment of the dorsal midline structures.

An ascidian homologue of vertebrate BMPs-5-8 is expressed in the midline of the anterior neuroectoderm and in the midline of the ventral epidermis of the embryo

The ascidian tadpole larva is thought to be the prototype for the ancestral chordate. Although ascidians show a highly determinate mode of development, recent studies suggest significant roles of cell-cell interaction during embryogenesis. To elucidate the signaling molecules responsible for the cellular interaction, we investigated an ascidian homologue of the transforming growth factor beta (TGF-beta) superfamily. HrBMPa is an ascidian member of the 60A subclass of the BMP subfamily. Molecular phylogenetic analysis suggested that HrBMPa branched prior to further divergence of vertebrate BMPs-5-8. The zygotic expression of HrBMPa was initiated around gastrulation. HrBMPa transcripts were first evident in precursor cells of the spinal cord, notochord, epidermis and nervous system, although signals in the first two regions quickly disappeared. In neurulae and early tailbud embryos, transcripts were evident in the adhesive organ, midline of the anterior dorsal neuroectoderm and midline of both ventral and dorsal ectoderm, suggesting that HrBMPa plays a major role in neuroectodermal cell differentiation during embryogenesis. This HrBMPa expression profile resembled that of Xenopus BMP-7, implying a primordial function of BMP-7 among vertebrate BMPs-5-8.

Assessment of arterial invasion in pancreatic cancer using color Doppler ultrasonography

OBJECTIVE

We report the first study on the value of color Doppler ultrasonography (CDUS) in assessing arterial invasion of pancreatic cancer.

METHODS

The relationships between tumors and surrounding major splanchnic arteries (celiac, superior mesenteric, common hepatic, splenic, and gastroduodenal arteries) were preoperatively evaluated with CDUS in 33 consecutive patients with pancreatic cancer. When a tumor partially or completely surrounded the artery, the invasion was diagnosed as positive. Imaging results were then compared with angiographic, surgical, and histopathological findings.

RESULTS

In 22 nonsurgical patients, the correspondence rate of CDUS with angiography for the presence of invasion, absence of invasion, and overall was 78%, 95%, and 88%, respectively. In 11 surgical patients, a sensitivity of 60%, specificity of 93%, and accuracy of 87% for detection of arterial invasion were obtained in comparing CDUS with surgical and histopathological findings. There was no significant difference between the accuracy of CDUS and that of CT, or that of angiography. However, the accuracy of CDUS was higher than that of CT (72%) and equal to that of angiography (91%).

CONCLUSION

Color Doppler ultrasonography is useful for detecting arterial invasion in pancreatic cancer. It may make angiography unnecessary, especially with advanced tumors, if thorough evaluation for the large artery invasion is performed initially.

Cloning of rat type I receptor cDNA for bone morphogenetic protein-2 and bone morphogenetic protein-4, and the localization compared with that of the ligands

A rat homologue cDNA of mouse (Koenig et al. [1994] Mol. Cell Biol. 14:5961-5974; Suzuki et al. [1994] Proc. Natl. Acad. Sci. USA 91: 10255-10259) and human (ten Dijke et al. [1994] J. Biol. Chem. 269:16985-16988) type I receptors for BMP-2 and BMP-4 was cloned. Tissue distribution of the receptor mRNA was studied by in situ hybridization using rats at embryonic days 9, 13, 15, and 18 as well as 1- and 5-day-old postnatal rats. In the rats at embryonic days 9, 13, and 15, the receptor mRNA was diffusely expressed over the embryonic bodies. At embryonic day 18, the receptor mRNA expression was high in the hair and whisker follicles, tooth bud, cartilage, bone, digestive organs, lung, kidney, heart, and meninges. The receptor mRNA was expressed over a much wider area than those of the ligands in many organs. In the lung and digestive organs, the receptor mRNA was diffusely expressed and most highly expressed in the bronchial epithelium and muscle layer, respectively, in both of which mRNA expression of the ligands was undetectable. The receptor mRNA was highly expressed in the meninges, although neither of the ligands was expressed in or near this region. These results suggest that this receptor participates in both mesoderm formation in early embryogenesis and differentiation of mesodermal cells during maturation of organs, and further suggest the presence of another factor(s) that binds the type I receptor.

Pancreatic arteriovenous malformation with duodenal ulcer. Demonstration by color Doppler ultrasonography

We report the color Doppler ultrasonography features of arteriovenous malformation (AVM) of the pancreas, a very rare disease. The patient was a 52-year-old man with congenital AVM of the pancreas and a duodenal ulcer that had been resistant to medication. Endoscopic color Doppler ultrasonography (color Doppler EUS) revealed many abnormal color signals showing pulsatile wave form at the portion of the duodenal wall involving the duodenal ulcer. Extracorporeal color Doppler ultrasonography revealed a mosaic-like color signal, caused by turbulent flow, in the portal trunk. Angiography demonstrated a vascular network with extensive proliferation at the pancreatic head and early portal filling. It is possible that the pancreatic AVM had caused the duodenal ulcer. Color Doppler EUS can be a useful modality for detection of vessel abnormalities of the gastrointestinal tract.

Laparoscopic transcystic cholangioscopic lithotripsy for common bile duct stones during laparoscopic cholecystectomy

BACKGROUND AND STUDY AIMS

Following the recent introduction of laparoscopic cholecystectomy (LC) for cholecystolithiasis, treatment of concomitant common bile duct (CBD) stones has been evaluated by using laparoscopic choledochotomy, a transcystic approach, or by means of endoscopic sphincterotomy (ES) before or after LC.

PATIENTS AND METHODS

During laparoscopic cholecystectomy, we attempted lithotripsy of CBD stones using laparoscopic transcystic cholangioscopy with lithotripsy (LTCL), in 70 patients out of 950 laparoscopic cholecystectomies. Preparatory tests included laboratory values, ultrasound, and performance of endoscopic retrograde cholangiography (ERC) with placement of a nasobillary tube (without sphincterotomy).

RESULTS

Introduction of the cholangioscope into the CBD was successful in 65 patients (92.9%) and CBD clearance was completely achieved by LTCL alone in 51 (78.5%). The overall success rate was therefore 73%. The remaining 19 cases required postoperative procedures such as extracorporeal shock-wave lithotripsy without ERC or ES (successful in all). The average hospital stay period was 9.4 days for patients in whom CBD clearance was achieved by LTCL alone. This period did not differ significantly from that of patients who underwent LC alone (8.4) days. The operation time was about 70 minutes longer for the LTCL group (total time 174 minutes on average) than for the LC group (107 minutes). We did not observe any series complications during or after LTCL (mean follow-up period: 34 months).

CONCLUSION

LTCL in combination with LC allows shortening of the hospital stay and a swift return to work for patients with CBD stones. This procedure also preserves the function of the sphincter of Oddi, so that the longterm prognosis for patients is likely to be very good.

TAB1: an activator of the TAK1 MAPKKK in TGF-beta signal transduction

Transforming growth factor-beta (TGF-beta) regulates many aspects of cellular function. A member of the mitogen-activated protein kinase kinase kinase (MAPKKK) family, TAK1, was previously identified as a mediator in the signaling pathway of TGF-beta superfamily members. The yeast two-hybrid system has now revealed two human proteins, termed TAB1 and TAB2 (for TAK1 binding protein), that interact with TAK1. TAB1 and TAK1 were co-immunoprecipitated from mammalian cells. Overproduction of TAB1 enhanced activity of the plasminogen activator inhibitor 1 gene promoter, which is regulated by TGF-beta, and increased the kinase activity of TAK1. TAB1 may function as an activator of the TAK1 MAPKKK in TGF-beta signal transduction.

Utility of endoscopic ultrasonography with color Doppler function for the diagnosis of islet cell tumor

OBJECTIVE

To evaluate the efficacy of endoscopic ultrasonography with color Doppler function for the diagnosis of islet cell tumor.

METHODS

Endoscopic ultrasonography was compared with other modalities such as ultrasonography, computed tomography, and angiography in the evaluation of seven patients with islet cell tumor and 28 patients with duct cell cancer.

RESULTS

In cases of islet cell tumor, the tumor detection rates by ultrasonography and endoscopic ultrasonography were 86% and 100%, respectively. Color signals were detected in 14% and 100% of the cases of islet cell tumor by ultrasonography and endoscopic ultrasonography, respectively. The pattern of color signals obtained was rich and abundant, showing pulsatile and/or continuous wave patterns. Angiography and computed tomography showed hypervascularity. However, in cases of duct cell cancer, the tumor detection rates by ultrasonography and endoscopic ultrasonography were 96% and 100%, respectively, whereas color signals were detected in 78% with both ultrasonography and endoscopic ultrasonography. The image of blood flow, which was connected to surrounding vessels, showed a linear pattern and few blood flow signals. In these cases, angiography and computed tomography demonstrated encasement of the artery or portal vein without hypervascularity.

CONCLUSIONS

Endoscopic ultrasonography was usefull for the localization and differential diagnosis of islet cell tumor because of its excellent ability to visualize small lesions and tumor vascularity simultaneously.

The usefulness of ultrasonic microprobe imaging for endoscopic variceal ligation

OBJECTIVES

This study investigated whether ultrasonic microprobe (UMP) imaging was useful in judging the therapeutic effect of endoscopic variceal (EVL) on varices as well as assessing varices and surrounding vessels before and after EVL.

METHODS

UMP imaging was performed repeatedly safely and easily via the biopsy channel of an endoscope in 20 patients with esophageal varices. Using this modality in combination with our method of "intensive ligation," we treated esophageal varices successfully.

RESULTS

Before EVL, UMP imaging displayed esophageal varices, periesophageal collaterals, and the azygous vein as echo-free lumens. In 15 of 20 patients, UMP imaging clearly detected the perforating vein, one of the optimal ligation sites for EVL, connecting the varix and collateral vein. Just after EVL, UMP imaging revealed a hyperechoic change ("snow ball" sign or "snow channel" sign), indicating blood flow stasis in the esophageal varices. On subsequent EVL, UMP imaging showed the cross-sectional area of varices was undetectable (occluded) or partially detectaable. After repeated EVL (2.9 treatment sessions on average), UMP imaging, as well as endoscopy, indicated that almost all varices were eradicated (undetectable). However, UMP imaging demonstrated that neither collaterals nor the azygous vein had significantly changed in size.

CONCLUSIONS

This modern diagnostic modality provided a clinical adjunct to current endoscopy when observing esophageal varices and surrounding vessels before and after EVL to determine the need for additional therapy.

NE-induced contraction, alpha 1-adrenergic receptors, and Ins(1,4,5)P3 responses in cerebral arteries

Adrenergic-mediated responses in cerebral vessels in vitro differ with vessel segment. We performed this study to test the hypothesis that these vessel-specific cerebral artery norepinephrine (NE)-induced contractility changes are mediated in part by differences in alpha 1-adrenergic receptor (alpha 1-R) density (Bmax) or antagonist dissociation constant (KD), and/or inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] synthesis. In common carotid (Com), circle of Willis (Wil), and middle cerebral arteries (MCA) from adult sheep we measured NE-induced contractions. We also quantified alpha 1-R in these, and in anterior, middle, and posterior (AMP) cerebral arteries and cerebral microvessels (Micro). In addition, we quantified NE-induced Ins(1,4,5)P3 synthesis. pD2 values of Com and MCA were 5.2 +/- 0.1 and 6.3 +/- 0.1, respectively. In contrast, the MCA maximum response to NE compared with K+ was much lower than that of the Com. In the Com, Wil, AMP, and Micro, alpha 1-R Bmax was 54 +/- 3, < 5 +/- 2, 23 +/- 3, and 35 +/- 3 fmol/mg protein, respectively. KD averaged 0.20 +/- 0.05 nM in the several vessel groups. In Com and in AMP cerebral arteries, NE produced a rapid increase in Ins(1,4,5)P3 with a peak at 45 s, and 50% effective concentration of 5.5 +/- 0.2 microM. NE stimulated a 240% increase of Ins(1,4,5)P3 in both Com and AMP, whereas Wil showed essentially no response. The ovine MCA was more sensitive to NE than was the Com. In contrast, MCA showed a much lower maximum contractile response to NE compared with K+. Cerebral arteries (AMP) had only about half the alpha 1-R density of the Com. In AMP cerebral arteries, both the basal and NE-stimulated Ins(1,4,5)P3 values were much less than those of the Com. In MCA, the ratio of Ins(1,4,5)P3 response to alpha 1-R Bmax was much greater than in Com. These findings suggest important artery-to-artery differences in components of the cerebrovascular alpha 1-R-mediated contractile pathway. They also suggest considerable potential for modulation of pharmacomechanical coupling and homeostatic regulation of cerebrovascular tone.

Involvement of Ras/Raf/AP-1 in BMP-4 signaling during Xenopus embryonic development

Previously, we elucidated the role of bone morphogenetic protein 4 (BMP-4) in the dorsal-ventral patterning of the Xenopus embryo by using a dominant negative mutant of the BMP-4 receptor (DN-BR). The present paper describes the involvement of Ras, Raf, and activator protein 1 (AP-1) in BMP-4 signaling during Xenopus embryonic development. The AP-1 activity was determined by injecting an AP-1-dependent luciferase reporter gene into two-cell-stage Xenopus embryos and measuring the luciferase activity at various developmental stages. We found that injection of BMP-4 mRNA increased AP-1 activity, whereas injection of DN-BR mRNA inhibited AP-1 activity. Similar inhibitory effects were seen with injection of mRNAs encoding dominant negative mutants of c-Ha-Ras, c-Raf, or c-Jun. These results suggest that the endogenous AP-1 activity is regulated by BMP-4/Ras/Raf/Jun signals. We next investigated the effects of Ras/Raf/AP-1 signals on the biological functions of BMP-4. DN-BR-induced dorsalization of the embryo, revealed by the formation of a secondary body axis or dorsalization of the ventral mesoderm explant analyzed by histological and molecular criteria, was significantly reversed by coinjection of [Val12]Ha-Ras, c-Raf, or c-Jun mRNA. Furthermore, the BMP-4-stimulated erythroid differentiation in the ventral mesoderm was substantially inhibited by coinjection with the dominant negative c-Ha-Ras, c-Raf, or c-Jun mutant. Our results suggest the involvement of Ras/Raf/AP-1 in the BMP-4 signaling pathway.

EM523L, a nonpeptide motilin agonist, stimulates gastric emptying and pancreatic polypeptide secretion

We investigated the efficacy and the mechanism of action of EM523L, a nonpeptide motilin agonist (motilide), on the stimulation of gastric emptying and on the release of gut peptides after ingestion of a solid meat in normal controls (n = 8) and in diabetic patients (n = 8) with signs of neuropathy. A dose of 2 mg EM523L was administered IV over 15 min just after ingestion of a solid meal (200 kcal Gastric emptying was measured by a radionuclide technique. EM523L accelerated gastric emptying and markedly augmented postprandial pancreatic polypeptide (PP) response in both normal control and diabetic patients. This may suggest the mediation of the Vagal-cholinergic pathway to accelerate gastric emptying. The present study offers a promising therapeutic potential of the motilide in gastrointestinal motility disorders like those observed in diabetics mellitus.