Structure-Based SAR in the Design of Selective or Bifunctional Nociceptin (NOP) Receptor Agonists

The nociceptin opioid receptor (NOP), the fourth member of the opioid receptor family, and its endogenous peptide ligand, nociceptin or orphanin FQ (N/OFQ), play a vital role in several central nervous system pathways regulating pain, reward, feeding, anxiety, motor control and learning/memory. Both selective NOP agonists as well as bifunctional agonists at the NOP and mu opioid receptor (MOP) have potential therapeutic applications in CNS disorders related to these processes. Using Surflex-Dock protocols, we conducted a computational structure-activity study of four scaffold classes of NOP ligands with varying NOP-MOP selectivity. By docking these compounds into the orthosteric binding sites within an active-state NOP homology model, and an active-state MOP crystal structure, the goal of this study was to use a structure-based drug design approach to modulate NOP affinity and NOP vs. MOP selectivity. We first docked four parent compounds (no side chain) to determine their binding interactions within the NOP and MOP binding pockets. Various polar sidechains were added to the heterocyclic A-pharmacophore to modulate NOP ligand affinity. The substitutions mainly contained a 1-2 carbon chain with a polar substituent such as an amine, alcohol, sulfamide, or guanidine. The SAR analysis is focused on the impact of structural changes in the sidechain, such as chain length, hydrogen bonding capability, and basic vs neutral functional groups on binding affinity and selectivity at both NOP and MOP receptors. This study highlights structural modifications that can be leveraged to rationally design both selective NOP and bifunctional NOP-MOP agonists with different ratios of functional efficacy.

Discovery and Structure-Activity Relationships of Nociceptin Receptor Partial Agonists That Afford Symptom Ablation in Parkinson's Disease Models

A novel series of C(3)-substituted piperdinylindoles were developed as nociceptin opioid receptor (NOP) partial agonists to explore a pharmacological hypothesis that NOP partial agonists would afford a dual pharmacological action of attenuating Parkinson's disease (PD) motor symptoms and development of levodopa-induced dyskinesias. SAR around the C-3 substituents investigated effects on NOP binding, intrinsic activity, and selectivity and showed that while the C(3)-substituted indoles are selective, high affinity NOP ligands, the steric, polar, and cationic nature of the C-3 substituents affected intrinsic activity to afford partial agonists with a range of efficacies. Compounds 4, 5, and 9 with agonist efficacies between 25% and 35% significantly attenuated motor deficits in the 6-OHDA-hemilesioned rat model of PD. Further, unlike NOP antagonists, which appear to worsen dyskinesia expression, these NOP partial agonists did not attenuate or worsen dyskinesia expression. The NOP partial agonists and their SAR reported here may be useful to develop nondopaminergic treatments for PD.

A bifunctional nociceptin and mu opioid receptor agonist is analgesic without opioid side effects in nonhuman primates

Misuse of prescription opioids, opioid addiction, and overdose underscore the urgent need for developing addiction-free effective medications for treating severe pain. Mu opioid peptide (MOP) receptor agonists provide very effective pain relief. However, severe side effects limit their use in the clinical setting. Agonists of the nociceptin/orphanin FQ peptide (NOP) receptor have been shown to modulate the antinociceptive and reinforcing effects of MOP agonists. We report the discovery and development of a bifunctional NOP/MOP receptor agonist, AT-121, which has partial agonist activity at both NOP and MOP receptors. AT-121 suppressed oxycodone's reinforcing effects and exerted morphine-like analgesic effects in nonhuman primates. AT-121 treatment did not induce side effects commonly associated with opioids, such as respiratory depression, abuse potential, opioid-induced hyperalgesia, and physical dependence. Our results in nonhuman primates suggest that bifunctional NOP/MOP agonists with the appropriate balance of NOP and MOP agonist activity may provide a dual therapeutic action for safe and effective pain relief and treating prescription opioid abuse.

Buprenorphine requires concomitant activation of NOP and MOP receptors to reduce cocaine consumption

Buprenorphine's clinical use is approved for the treatment of heroin addiction; however, evidence supporting its efficacy in cocaine abuse also exists. While for heroin it has been demonstrated that the effect of buprenorphine is mediated by its ability to activate μ-opioid peptide receptor (MOP) receptors, the mechanism through which it attenuates cocaine intake remains elusive. We explored this mechanism using operant models where rodents were trained to chronically self-administer cocaine for 2 hours daily. Buprenorphine (0.3, 1.0 and 3.0 mg/kg) given intraperitoneally 90 minutes before access to cocaine significantly and dose dependently reduced its intake. Pre-treatment with naltrexone or with the selective nociceptin/orphanin FQ peptide (NOP) antagonist SB-612111 did not prevent buprenorphine-induced reduction of cocaine intake. However, when naltrexone and SB-612111 were combined, the effect of buprenorphine on cocaine was completely prevented. To confirm that co-activation of MOP and NOP receptors is the underlying mechanism through which buprenorphine reduces cocaine intake, three compounds, namely, AT-034, AT-201 and AT-202, with a range of affinity and intrinsic activity profiles for MOP and NOP receptors, but weak ability for kappa-opioid peptide receptor (KOP) transmission, were tested. Consistent with our hypothesis based on buprenorphine's effects, results demonstrated that AT-034 and AT-201, which co-activate MOP and NOP receptors, reduced cocaine self-administration like buprenorphine. AT-202, which selectively stimulates NOP receptors, was not effective. Together, these data demonstrate that for buprenorphine, co-activation of MOP and NOP receptors is essential to reduce cocaine consumption. These results open new vistas on the treatment of cocaine addiction by developing compounds with mixed MOP/NOP agonist properties.

In vitro functional characterization of novel nociceptin/orphanin FQ receptor agonists in recombinant and native preparations

Nociceptin/Orphanin FQ (N/OFQ) regulates several biological functions via selective activation of the N/OFQ receptor (NOP). In this study novel nonpeptide NOP ligands were characterized in vitro in receptor binding and [³⁵S]GTPγS stimulated binding in membranes of cells expressing human NOP and classical opioid receptors, calcium mobilization assay in cells coexpressing the receptors and chimeric G proteins, bioluminescence resonance energy transfer (BRET) based assay for studying NOP receptor interaction with G protein and arrestin, the electrically stimulated mouse vas deferens and the mouse colon bioassays. The action of the AT compounds were compared with standard NOP agonists (N/OFQ and Ro 65-6570) and the NOP selective antagonist SB-612111. AT compounds displayed high NOP affinity and behaved as NOP agonists in all the functional assays consistently showing the following rank order of potency AT-127≥AT-090≥AT-035>AT-004= AT-001. AT compounds behaved as NOP full agonists in the calcium mobilization and mouse colon assays and as partial agonists in the [³⁵S]GTPγS and BRET assays. Interestingly AT-090 and AT-127, contrary to standard nonpeptide agonists that display G protein biased agonism, behaved as an unbiased agonists. AT-090 and AT-127 displayed higher NOP selectivity than Ro 65-6570 at native mouse receptors. AT-090 and AT-127 might be useful pharmacological tools for investigating the therapeutic potential of NOP partial agonists.

Small-molecule nociceptin receptor agonist ameliorates mast cell activation and pain in sickle mice

Treatment of pain with morphine and its congeners in sickle cell anemia is suboptimal, warranting the need for analgesics devoid of side effects, addiction and tolerance liability. Small-molecule nociceptin opioid receptor ligands show analgesic efficacy in acute and chronic pain models. We show that AT-200, a high affinity nociceptin opioid receptor agonist with low efficacy at the mu opioid receptor, ameliorated chronic and hypoxia/reoxygenation-induced mechanical, thermal and deep tissue/musculoskeletal hyperalgesia in HbSS-BERK sickle mice. The antinociceptive effect of AT-200 was antagonized by SB-612111, a nociceptin opioid receptor antagonist, but not naloxone, a non-selective mu opioid receptor antagonist. Daily 7-day treatment with AT-200 did not develop tolerance and showed a sustained anti-nociceptive effect, which improved over time and led to reduced plasma serum amyloid protein, neuropeptides, inflammatory cytokines and mast cell activation in the periphery. These data suggest that AT-200 ameliorates pain in sickle mice via the nociceptin opioid receptor by reducing inflammation and mast cell activation without causing tolerance. Thus, nociceptin opioid receptor agonists are promising drugs for treating pain in sickle cell anemia.

High affinity α3β4 nicotinic acetylcholine receptor ligands AT-1001 and AT-1012 attenuate cocaine-induced conditioned place preference and behavioral sensitization in mice

Cholinergic signaling via the nicotinic acetylcholine receptors (nAChRs) in the mesolimbic circuitry is involved in the rewarding effects of abused drugs such as cocaine and opioids. In mouse studies, nonselective nAChR antagonist mecamylamine blocks cocaine-induced conditioned place preference (CPP) and behavioral sensitization. Among subtype-selective nAChR antagonists, the β2-selective antagonist dihydrobetaerythroidine and α7 antagonist methyllycaconitine (MLA), but not MLA alone prevent behavioral sensitization to cocaine. Since the role of the α3β4 nAChR subtype in the rewarding and behavioral effects of cocaine is unknown, the present study investigated the effect of two potent and selective α3β4 nAChR ligands, AT-1001 and AT-1012, on the acquisition of cocaine-induced CPP and behavioral sensitization in mice. At 5-30mg/kg, cocaine produced robust CPP, whereas behavioral sensitization of locomotor activity was only observed at the higher doses (20-30mg/kg). Pretreatment with AT-1001 (1-10mg/kg) or AT-1012 (3-10mg/kg) blocked CPP induced by 5mg/kg cocaine, but not by 30mg/kg cocaine. Lower doses of AT-1001 (0.3-1mg/kg) and AT-1012 (1-3mg/kg) did not affect the increase in locomotor activity induced by 5 or 30mg/kg cocaine. But AT-1001, at these doses, blocked locomotor sensitization induced by 30mg/kg cocaine. These results indicate that the α3β4 nAChR play a role in the rewarding and behavioral effects of cocaine, and that selective α3β4 nAChR ligands can attenuate cocaine-induced behavioral phenomena. Since the selective α3β4 nAChR functional antagonist AT-1001 has also been shown to block nicotine self-administration in rats, the present results suggest that α3β4 nAChRs may be a target for the treatment of cocaine addiction as well as for cocaine-nicotine comorbid addiction.

AT-1001: a high-affinity α3β4 nAChR ligand with novel nicotine-suppressive pharmacology

BACKGROUND AND PURPOSE

The α3β4 subtype of nicotinic acetylcholine receptors (nAChRs) has been implicated in mediating nicotine reinforcement processes. AT-1001 has been recently described as a high-affinity and selective α3β4 nAChR antagonist that blocks nicotine self-administration in rats. The aim of this study was to investigate the mechanism of action underlying the nicotine-suppressive effects of AT-1001.

EXPERIMENTAL APPROACH

Effects of AT-1001 were determined using in vitro assays and rat models of nicotine addiction, and compared with varenicline.

KEY RESULTS

AT-1001 and its analogue AT-1012 were functionally selective as antagonists for α3β4 over α4β2 nAChRs, but not to the same extent as the binding selectivity, and had partial agonist activity at α3β4 nAChRs. In contrast, varenicline was a partial agonist at α4β2, a weak agonist at α3β4 and inhibited α4β2 at a much lower concentration than it inhibited α3β4 nAChRs. AT-1001 and varenicline also had very different in vivo properties. Firstly, AT-1001 did not exhibit reinforcing properties per se while varenicline was self-administered. Secondly, systemic treatment with AT-1001 did not induce reinstatement of nicotine seeking but rather attenuated reinstatement induced by varenicline, as well as nicotine. Finally, unlike varenicline, AT-1001 selectively blocked nicotine self-administration without altering alcohol lever pressing as assessed in an operant co-administration paradigm.

CONCLUSIONS AND IMPLICATIONS

These findings describe a more complex AT-1001 in vitro profile than previously appreciated and provide further support for the potential of AT-1001 and congeners as clinically useful compounds for smoking cessation, with a mechanism of action distinct from currently available medications.

Functional characterization of AT-1001, an α3β4 nicotinic acetylcholine receptor ligand, at human α3β4 and α4β2 nAChR

INTRODUCTION

Genome-wide association studies linking the α3, β4, and α5 nicotinic acetylcholine receptor (nAChR) subunits to nicotine dependence suggest that α3β4* nAChR may be targets for smoking cessation pharmacotherapies. We previously reported that AT-1001, a selective α3β4* nAChR ligand binds with high affinity to rat α3β4 and human α3β4α5 nAChR, antagonizes epibatidine-induced activation of rat α3β4 nAChR in HEK cells and potently inhibits nicotine self-administration in rats.

METHODS

Two-electrode voltage clamp was used for functional characterization of AT-1001 at recombinant human α3β4 and α4β2 nAChR expressed in Xenopus oocytes.

RESULTS

Concentration-response curves show that AT-1001 is a partial agonist at human α3β4 nAChR, evoking up to 35% of the maximal acetylcholine (ACh) response (50% effective concentration [EC50] = 0.37 μM). AT-1001 showed very little agonist activity at the α4β2 nAChR, evoking only 6% of the ACh response (EC50 = 1.5 μM). Pre- and co-application of various concentrations of AT-1001 with 50 μM ACh revealed a complex pattern of activation-inhibition by AT-1001 at α3β4 nAChR, which was best fitted by a 2-site equation. At α4β2 nAChR, co-exposure of AT-1001 with ACh only showed inhibition of ACh current with a shallower curve.

CONCLUSIONS

AT-1001 is a partial agonist at the human α3β4 nAChR and causes desensitization at concentrations at which it evokes an inward current, resulting in an overall functional antagonism of α3β4 nAChR. AT-1001 does not significantly activate or desensitize α4β2 nAChR at the same concentrations as at the α3β4 nAChR, but does inhibit ACh responses at α4β2 nAChR at higher concentrations. A combination of these mechanisms may underlie the inhibition of nicotine self-administration by AT-1001, suggesting that AT-1001 and compounds from this class may have clinical potential for smoking cessation pharmacotherapy.

Alterations of the p53 tumor-suppressor gene and ki-ras oncogene in human pancreatic cancer-derived cell-lines with different metastatic potential

Alterations of the p53 and Ki-ras genes were examined in 12 human pancreatic cancer-derived cell lines with different metastatic potential. Point mutations of the Ki-ras gene at codon 12 were found in 10 out of 12 cell lines (83%), while abnormalities of the p53 gene were identified in 8 out of 12 cell lines (67%) which included point mutations (n=7) and one base deletion (n=1). The comparison between alterations of the p53 and Ki-ras genes showed that all the 12 cell lines revealed alterations of both genes or one of these genes regardless of the metastatic potential. Further, same alterations of the Ki-ras gene or p53 gene were noted among the cell lines with increased metastatic potential and their parental cell lines. These findings suggest that alterations of the p53 gene, like the Ki-ras gene is a frequent event in pancreatic cancer, and could contribute cooperatively in the oncogenic steps of pancreatic cancer. It is also suggested that the genetic changes of the p53 and Ki-ras genes are not substantially associated with the metastatic potential in pancreatic cancer.

Possible association of nm23 gene-expression and ki-ras point mutations with metastatic potential in human pancreatic cancer-derived cell-lines

Nm23 gene expression and Ki-ras point mutations of eight human pancreatic cancer-derived cell lines with different metastatic capabilities were studied. Nm23 gene expression was significantly reduced in the cell lines with a high metastatic potential as compared with those with a low meta static potential (p<0.05). The same mutation at codon 12 of the Ki-ras gene (Gly12 to Asp12) was found in all cell lines with a high metastatic potential. These findings suggest a possible association of metastatic potential with Nm23 gene expression as well as the mutation of Ki-ras gene in human pancreatic cancer.

Elevation of serum albumin levels in nagase analbuminemic rats by allogeneic bone marrow cell transplantation

We investigated the feasibility of correcting the congenital absence of albumin in Nagase analbuminemic rats (NARs) by allogeneic bone marrow cell transplantation (BMT). Seven-week-old male NARs were used as recipients, and 6- to 8-week-old male Sprague-Dawley (SD) rats were used as allograft donors. NARs were divided into three groups: a BMT group (n=10) in which bone marrow cells were infused into the liver; a hepatocyte transplantation (HCT) group (n=8) in which hepatocytes were transplanted into the liver, and a control group (n=8) in which PBS was injected into the portal vein. Serum albumin levels were measured as an indicator of the function of the grafted cells, and the phenotypic characteristics of the engrafted cells in the recipient's liver were assessed with immunohistochemical and immunofluorescence techniques. At 8 weeks after cell transplantation, the serum albumin levels of the BMT group and HCT group were significantly higher than in the control group. The hepatocyte-like cells derived from bone marrow cells expressed albumin in liver of the NARs. According to this result, bone marrow cells can differentiate into hepatocyte-like cells in vivo. The results show that BMT is an effective treatment for congenital analbuminemia in a rat model and suggest that allogeneic BMT can be used as an efficient therapy for hereditary metabolic diseases.

Tracheal narrowing secondary to airway obstruction in two cats

Tracheal narrowing is described in two cats. In both cases, inspiratory radiographs demonstrated tracheal narrowing just cranial to the thoracic inlet; no narrowing was seen on expiratory radiographs. Magnetic resonance imaging revealed suspected nasal tumours in both cases, but no abnormalities were identified in the region of the narrowed trachea. Nasal biopsy confirmed intranasal lymphoma in one cat and nasal adenocarcinoma in the other. The former cat was treated with chemotherapy. The owner of the latter cat declined further treatment. The tracheal narrowing disappeared after the initiation of chemotherapy in the cat with intranasal lymphoma and it is suggested that the narrowing might have been associated with the nasal tumour. A careful evaluation of the airway, especially cranial to the narrowing, is recommended in cases of tracheal narrowing in cats.

[Significance of thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD) activity in breast cancer tissue]

TS, DPD, uridine phosphorylase and thymidine phosphorylase are enzymes involved in the metabolism of the anticancer drug pyrimidine fluoride. In this study, levels of these enzymes were measured in 47 women with primary breast cancer. These enzyme levels were then compared to levels determined from breast cancer patients who received either preoperative chemotherapy or nothing, in order to determine whether they might predict clinical outcome. The TS inhibition rate was significantly higher (p < 0.05) in patients receiving preoperative chemotherapy (20.4 +/- 13.3%) than in the untreated group (11.4 +/- 9.8%). No other significant differences in activity were noted between the treated and untreated groups for any of the other enzymes studied. The activity of each enzyme at the tumor site and the tumor/normal (T/N) ratio were also compared between patients with and without recurrence. The TS inhibition rate at the tumor site was lower in recurring cases than in non-recurring cases, and the T/N ratio tended to be higher for DPD in patients with recurrences. These findings indicate that the TS inhibition rate and DPD activity may be useful predictors for early recurrence of breast cancer following surgery.

Pancreatic arteriovenous malformation observed to bleed from the bile duct and a duodenal ulcer: report of a case

A 48-year-old man with recurrent episodes of biliary colic and subsequent pancreatitis was admitted to undergo a cholecystectomy. A gastroduodenal fiberscopic examination was performed because of massive melena on the seventh day after admission. It revealed a shallow ulcer on the posterior wall of a duodenal bulbus with rubor and an exposed vessel, which was clipped endoscopically to stop the bleeding. Further observations showed the papilla of Vater to be bleeding from the papilla. A contrast-enhanced abdominal computed tomography scan demonstrated a dilatation of the common bile duct and several dilated vasculatures around the portal vein, some of which drained into the portal vein. Based on the angiography findings, a diagnosis of arteriovenous malformation in the pancreas head was obtained and an embolization of the gastroduodenal artery was performed. Although the melena subsided, he underwent a pylorus-preserving pancreatoduodenectomy to prevent the recurrence of hemorrhaging. The histopathological findings of the bile duct revealed inflammatory cell infiltration and a detachment of the epithelium, except in a small part of the bile duct. A rupture of a damaged vessel inside the bile duct was observed, which was thought to be the cause of hemobilia. Sections of the pancreatic head demonstrated an inflammatory lesion with fibrosis and saponification as well as a large degree of arteriovenous anastomosis. The patient was discharged on the 35th day after the operation following an uneventful postoperative course.

A case of acute phlegmonous gastritis successfully treated with antibiotics

Acute phlegmonous gastritis is a rare disorder in which bacterial infection occurs in the gastric wall. Gastrectomy involving the affected area has been thought to be an effective form of treatment. The authors report a case of a 32-year-old woman who had severe upper abdominal pain without signs of peritoneal irritation. Endoscopy showed edematous and reddened gastric mucosa with a mass lesion in the gastric antrum. Endoscopic ultrasonography showed thickening of the antral wall and a low-echoic mass in the gastric antrum, thought to represent a fluid collection. White pus was aspirated from the mass. Localized type of acute phlegmonous gastritis with a gastric abscess was diagnosed. Culture of the pus showed Streptococcus pneumoniae. Through early diagnosis without laparotomy, the patient's gastritis was successfully treated with antibiotics alone.

Pretreatment staging of endoscopically early gastric cancer with a 15 MHz ultrasound catheter probe

BACKGROUND

The usefulness of and problems associated with an ultrasound catheter probe in the pretreatment staging of endoscopically early gastric cancer remain unexplored.

METHODS

Endoscopic ultrasonography using a 15 MHz catheter probe of 2.6 mm diameter was performed in a prospective study to determine the pretherapy staging of endoscopically early gastric cancer in 78 patients. The results of the ultrasound images were compared with the histologic findings of the specimens obtained by endoscopic mucosal resection or surgical resection.

RESULTS

The accuracy of the catheter probe for depth of invasion of endoscopically early gastric cancers was 67% (52 of 78 patients). The accuracy in determining depth of invasion in relation to endoscopic type was significantly higher for the elevated type (91%) than for the depressed type of early cancer (56%) (p < 0.01). The staging accuracy classified by histologic type was significantly higher for differentiated (86%) than for undifferentiated (18%) cancer (p < 0.01). Staging accuracy decreased as tumor size increased. The accuracy, sensitivity, and specificity for nodal staging were 80%, 17%, and 90%, respectively.

CONCLUSIONS

A 15 MHz ultrasound catheter probe is most useful for determining depth of invasion when the tumor is histologically differentiated and endoscopically of the small elevated type early gastric cancer, but it is unreliable in the diagnosis of metastatic lymph nodes.

Alteration of the CDKN2A gene in pancreatic cancers: Is it a late event in the progression of pancreatic cancer?

Various genetic changes are involved in progression of various cancers. We examined alterations (deletion, sequence abnormalities, methylation) of the CDKN2A gene in cell lines and tumor tissues of pancreatic cancers. Some alterations of this gene were found in all the 12 cell lines examined. In the primary lesions of pancreatic cancers, homozygous or hemizygous deletion were found in 8 of 24 ductal carcinoma and 4 of 9 other types of carcinomas. It appears that there is an association between the alteration of this gene and tumor size, regional lymph node metastasis and hematogenous distant metastasis in the ductal carcinoma, but not in the other types of carcinomas. All the 5 liver metastatic lesions of the ductal carcinoma examined revealed homozygous or hemizygous deletion and 3 bp deletion. These results suggest that inactivation of the CDKN2A gene occurs more frequently in cell lines than in pancreatic cancer tissues. Such genetic events on the CDKN2A gene may play an important role possibly at a later step in the progression of pancreatic ductal carcinoma.

Carcinosarcoma of the uterus: magnetic resonance imaging

We report the magnetic resonance imaging (MRI) findings with a paramagnetic enhancement agent (gadopentetate dimeglumine (Gd-DTPA)) in a 70-year-old woman with carcinosarcoma of the uterus. In the present patient, the polypoid portion histologically most abundant in the sarcomatous component was strongly enhanced by Gd-DTPA and was clearly demonstrated with high signal intensities on contrast-enhanced T1-weighted images. We suggest that MRI with Gd-DTPA may be clinically useful for detection of carcinosarcoma, and that any patient having endometrial carcinoma with the polypoid portion, which is more strongly enhanced by Gd-DTPA within the tumor, may be suspected of carcinosarcoma.

Ovarian strumal carcinoid with markedly high serum levels of tumor markers

We report a 54-year-old woman with ovarian strumal carcinoid in association with dermoid cyst and mucinous cystadenoma in the same ovary and who had markedly high serum levels of CEA (202 ng/ml), CA125 (710 U/ml), and CA19-9 (11,500 U/ml). These tumor markers were not found in the thyroid tissue or carcinoid by immunohistochemical methods, but their serum levels decreased to below the cutoff levels after surgery. In our case, the change of serum levels of these tumor markers may be useful for the follow-up after surgery.

Comparison of plasma pancreastatin and GAWK concentrations, presumed processing products of chromogranin A and B, in plasma of patients with pancreatic islet cell tumors

Plasma pancreastatin (PST) and GAWK, peptides processed from chromogranin A and B, were elevated in patients with various neuroendocrine tumors. In the present study, we measured plasma PST- and GAWK-like immunoreactivity (LI) concentrations in 12 patients with pancreatic islet cell tumors and evaluated them as a marker for these tumors. We also performed the gel filtration of the plasma from a gastrinoma patient and investigated the processing of PST and GAWK in plasma. Elevation of plasma PST-LI was found in 4 of 12 patients (33%) and elevation of plasma GAWK-LI was found in 6 of 12 patients (50%). A significant correlation was not found between plasma PST- and GAWK-LI concentrations of the patients. In the gel permeation chromatography of the plasma from a gastrinoma patient, PST-LI composed of a single peak but GAWK-LI composed of several components with wide range molecular weights.

Plasma concentration of human atrial natriuretic hormone in patients with connective tissue diseases

Atrial natriuretic peptide (ANP), a peptide released from the cardiac atria, compensates blood volume expansion by its diuretic, natriuretic and vasoactive properties. We measured human plasma ANP(hANP) levels in patients with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA) and progressive systemic sclerosis (PSS) and found that their values were higher than those of healthy controls. In SLE patients, hANP levels correlated with serum creatinine concentration and the patients with proteinuria showed high levels of hANP. Administration of large amount of corticosteroid as a remission induction of the patients with SLE caused high levels of hANP. In patients with PSS, %FEV1 showed strong inverse correlations between hANP levels, and the patients with an enlarged second curvature of the heart had high levels of hANP. In patients with RA, no significant correlation was found between hANP levels and clinical variables including patients' age.

Effect of LHRH on plasma 7B2 in patients with gonadotropin-producing pituitary adenomas

Plasma immunoreactive (IR)-7B2 was measured in four patients with gonadotropin-producing pituitary adenomas. The basal level of plasma IR-7B2 was elevated in one of the four patients. Hyperresponse of plasma IR-7B2 to LHRH or LHRH/TRH was noted in two patients tested. 7B2 was positively stained in a paraffin-embedded section of gonadotropin-producing pituitary adenoma obtained at surgery. These findings suggest that 7B2 is produced in gonadotropin-producing pituitary adenomas and secreted into the blood stream under certain conditions. 7B2 may be a useful marker for gonadotropin-producing pituitary adenomas.

7B2, a possible marker for nonfunctioning pancreatic islet cell tumor

Plasma 7B2 was measured in 13 patients with pancreatic islet cell tumors, 11 with pancreatic adenocarcinoma and 31 normal subjects as a control. The mean (+/- SD) concentrations of plasma 7B2 in the normal subjects and the patients with pancreatic islet cell tumors were 67 +/- 10 and 1041 +/- 1786 pmol/l, respectively, and the value in the patients with pancreatic islet cell tumors was significantly higher than that in the normal subjects (p less than 0.01). Elevation of plasma 7B2 over the normal range, defined as less than the mean + 3SD value of those in the normal subjects, was found in 10 of 13 patients with pancreatic islet cell tumors including 4 with nonfunctioning tumor. Plasma 7B2 dropped into the normal range postoperatively in 3 patients with nonfunctioning tumor. Plasma 7B2 concentrations in the patients with pancreatic adenocarcinoma remained in the normal range. These results raise a possibility that 7B2 is a useful marker for pancreatic islet cell tumors, in particular nonfunctioning tumor.

[Study of intermittent intra-arterial infusion chemotherapy in liver metastases from squamous cell carcinoma]

There are few reports about the methods, amounts, and kinds of dosage about intermittent intra-arterial chemotherapy of liver metastases from primal pathological type's squamous cell carcinoma. Because they are less than liver metastases from adenocarcinoma of colon or stomach. Although it is important of other factors about the operative method of primary focus and metastases of the other parts, it is possible that those cases obtained the good prognosis and protected liver failure, if those liver metastases could be controlled well. In our department from January 1987 to December 1989, 9 cases of inoperative liver metastases of squamous cell carcinoma (esophagus: 4 cases, larynx: 3 cases and cervix of uterus 2 cases) were treated of intra-arterial infusion chemotherapy of FAM (5Fu 500 mg/week, ADM 30 mg/4 weeks and MMC 4 mg/2 weeks) and CDDP methods (only CDDP 10 mg/week). Cases of esophagus carcinoma were treated with FAM method. On the CT-scan one of the cases showed the reduction rate of more than 50% and was a Progressive Response (PC), and the SCC tumor marker decreased in 2 cases. However, 2 other cases died of liver failure. Cases of larynx were treated with FAM and CDDP methods. However, on the CT-scan all of the cases showed No Change (NC) nor decrease in SCC. But thinking of prognosis FAM was better than CDDP. Cases of cervix of uterus were treated with the FAM and CDDP methods. FAM was not different than the CDDP in the prognosis and effect.

[Hepatic infusion-chemotherapy of liver metastases from stomach cancer--comparative study for intraarterial group and non-intraarterial group]

Metastasis to the liver was detected in 96 out of 1,825 patients with gastric cancer treated at our department from April 1980 to March 1990, and was respectively found to be synchronous and metachronous in 63 and 33 of the 96 patients. We compared survival durations among these 96 patients according to synchronous or metachronous metastasis by dividing them into the intermittent intra-arterial chemotherapy (FAM) group (18 patients) and non-intra-arterial chemotherapy group (78 patients). In the comparison between the intra-arterial and non-intra-arterial groups, the survival duration was determined to be significantly longer in the intra-arterial group by Wilcoxon generalized test and Cox-Mantel test (p less than 0.01). Among the patients with synchronous metastasis, a significantly longer survival duration was also observed in the intra-arterial group (p less than 0.01). The direct effect of intra-arterial chemotherapy through CT was seen in 56% of the patients in the intra-arterial group. These results indicated the usefulness of FAM hepatic infusion chemotherapy for the treatment of metastasis of gastric cancer to the liver. It is expected that therapeutic results will be much more improved by selecting more effective anticancer drugs in the future.

Establishment and characterization of human pancreatic cancer cell lines in tissue culture and in nude mice

Three human pancreatic cancer cell lines, designated as KP-1N, KP-2 and KP-3 have been established in both tissue cultures and in nude mice. The KP-1N and KP-3 tumors were obtained from liver metastases of pancreatic tumors and the KP-2 tumors was of primary pancreatic origin. The patients' tumors from which KP-1N and KP-2 were derived showed characteristics of adenocarcinoma, and the KP-3 tumor had adenosquamous carcinoma characteristics. Inoculations of samples from surgical specimens into athymic nude mice resulted in tumor formation, with the tumors histologically closely resembling the original neoplasms. Subcutaneous injections of the established cell lines also induced tumor formation and the tumors histologically resembled the original lesion in the cases of KP-2 and KP-3 tumors, but the KP-1N tumors in the mice were histologically different from the surgical specimen. The KP-1N, KP-2 and KP-3 cell lines have been cultured continuously in a medium supplemented with 10% fetal calf serum for more than 20, 21 and 17 months, respectively. The KP-2 and KP-3 cell lines produced and released carbohydrate antigen 19-9 into the spent medium but the KP-1N cell line did not. KP-1N and KP-3, produced liver metastases after intrasplenic injection into nude mice, whereas KP-2 produced few liver colonies. Cell lines highly metastatic to the liver, KP-1NLs and KP-3Ls, were isolated from the liver colonies of KP-1N and KP-3, respectively.

[A study of low-dose intermittent intra-arterial infusion chemotherapy for liver metastasis in colorectal cancer]

Since 1985 we have performed low-dose intermittent intra-arterial infusion chemotherapy using an implantable device for inoperable liver metastasis derived from colorectal cancer. We estimated the efficiency of this treatment in terms of effective rates and survival period. We classified subjects into intra-arterial infusion group and general administration group for comparison. The former group was comprised of 54 cases (37 synchronia, 17 heterochronia) treated with low-dose intermittent intra-arterial infusion (FAM ia) from July 1985 to June 1989. The latter comprised 32 cases (17 synchronia, 15 heterochronia) treated with general chemotherapy (general administration of 5-FU and MMC) for three years before December 1986. Of the 37 cases (23 synchronia, 14 heterochronia) evaluated in the intra-arterial infusion group, we recognized 9 PR cases (24.3%; including 5 synchronia, 4 heterochronia). On the other hand, we found only 1 PR case in the general administration group. The 50% survival period in the intra-arterial infusion group was 370 days (380 days synchronia, 340 days heterochronia), against 260 days (270 days synchronia, 250 days heterochronia) in the general administration group. There were no statistically significant differences between the two groups. Although it was not possible for us to obtain satisfactory results in terms of the efficiency of intermittent low-dose intra-arterial infusion treatment, we have been conducting a randomized study considering drug types, drug administration methods, and background of patients to further investigate the efficiency of arterial infusion treatment.

Synthesis and antiinflammatory activity of novel 12 beta-substituted analogues of betamethasone

A series of 9 alpha-halo-12 beta-hydroxy and 12 beta-acyloxy analogues of betamethasone 17,21-dipropionate were synthesized and tested for topical antiinflammatory potency in the croton oil ear assay. The compounds were assayed for systemic absorption in the contralateral ear assay, in which it was found that 12 beta-hydroxy analogues 9, 13, and 15 were all absorbed but the corresponding 12 beta-esters 11a-e, 14, and 16 were not. On repeated high-dose applications to the mouse ear, there was no evidence of systemic absorption of any 12 beta-propionate ester as gauged by thymus weights (thymic involution) and plasma cortisol levels (adrenal suppression). Results of limited SAR studies showed that topical antiinflammatory activity and systemic absorption were not greatly influenced by the 9 alpha-halogen but were largely dependent on the polarity and size of the 12 substituent. While the optimal compounds 14 and 16 were less topically active than the controls beta- and beclomethasone dipropionate, unlike the controls, they displayed no systemic effects, even after repeated high-dose applications. Surprisingly, propionate 14 was devoid of atrophogenic activity.

[Various methods of catheter placement in hepatic arterial infusion--technique of catheter placement via a femoral artery]

A comparative analysis of the individual techniques was performed on a total of 106 cases undergoing various methods of catheter placement in hepatic infusion. The comparison of laparatomy (n = 44) with a percutaneous method (n = 62) disclosed a higher incidence of peptic ulcer in the latter. When two modes of percutaneous approach, including a trans-left subclavian arterial method (n = 36) and a trans-femoral arterial method (n = 26), were compared, a shorter average catheterization time (approximately 70 minutes) and a higher selective insertion rate (92.3%) were noted in the trans-femoral approach. For these reasons, our department adopts the trans-femoral method as the percutaneous method of choice. It is advisable for further studies to be made in order to clarify indications for the individual techniques and for anti-complication measures.

[First pass effect by infusing 99mTc-human serum albumin into the hepatic artery]

The fundamental principles of intra-arterial infusion chemotherapy are thought to be increased local drug concentration and the "first-pass" effect. The concentration in the rest of the body can only be decreased if there is local elimination of the infused drug before reaching the systemic circulation. This is referred to as the "first-pass" effect. In the evaluation of "first-pass" effect, the uptake of liver after infusing 99mTc-human serum albumin (99mTc-HSA) in the hepatic artery by injecting the subcutaneously implanted silicon reservoir was compared with that obtained after intravenous administration of 99mTc-HSA. In order to remove the factor of portal infusion, each count of liver up take had been continued for only 24 seconds after starting the liver uptake. The results are as follows: for 24 cases excepting 6 cases with catheter obstruction, the mean i.a./i.v. ratio was 7.92 +/- 3.34 (range 3.25 to 17.25). Although the elimination rate of drugs in the liver varies with each drug, the infusion of intraarterial chemotherapy should be about 8 times more concentrative than intravenous administration on the "first-pass" effect.