Centrally administered neuropeptide Y (NPY) inhibits gastric emptying and intestinal transit in the rat

Neuropeptide Y is distributed abundantly not only in the brain, but also in the gastrointestinal tract and suppresses intestinal muscle contraction in isolated muscle preparations. The purpose of the present study was to determine whether centrally administered neuropeptide Y modulated gastric emptying and intestinal transit in conscious rats. Graded doses of neuropeptide Y were administered intracisternally 1 min before ingestion of test meals through an oral tube. Four hours after ingestion of 60 Amberlite pellets, the rats were sacrificed and residual pellets in the stomach and the small intestine segments were counted to calculate the solid meal transit rate. The liquid meal transit rate was calculated 1 hr after 0.07% phenol red ingestion by determining the residual phenol red in the stomach and the small intestine segments. Neuropeptide Y elicited potent suppression of gastric emptying and intestinal transit of both solid and liquid meals. Pretreatment with propranolol antagonized, whereas phentolamine did not affect, the suppressive effect of central neuropeptide Y. Although carbachol blocked the effects of neuropeptide Y, neither atropine nor hexamethonium altered the actions of neuropeptide Y. In conclusion, centrally administered neuropeptide Y strongly inhibited gastrointestinal transit by stimulating a beta-adrenergic pathway.

Cardiac protection by ischaemic preconditioning is not mediated by myocardial stunning

OBJECTIVE

Previous studies have shown that cardiac protection by ischaemic preconditioning wanes before contractile function recovers; thus stunning is insufficient to cause preconditioning. To test whether reduced contractile effort is necessary for preconditioning induced protection, the effect on myocardial infarct size of restoring contractile function with dobutamine was examined in preconditioned and control dogs.

METHODS

In two experimental groups (groups P and P+D), preconditioning was produced by four 5 min occlusions of the left anterior descending coronary artery, each separated by 5 min of reperfusion. Contractile function was assessed by sonomicrometry 5 min after completion of the preconditioning protocol. In group P+D, dobutamine (average dose = 5 micrograms.kg-1.min-1) was then infused intravenously to restore systolic shortening to baseline. The artery then was reoccluded for 40 min of sustained ischaemia followed by 4 d of reperfusion. Two additional groups of non-preconditioned control dogs (groups C and C+D) also underwent 40 min of coronary occlusion and 4 d of reperfusion. Group C+D received a dobutamine infusion beginning 15 min before and during the 40 min occlusion to match the dobutamine received in group P+D, whereas group C received normal saline.

RESULTS

Preconditioning caused mild postischaemic contractile dysfunction (50% decrease in systolic shortening) which was easily reversed by dobutamine treatment. Dobutamine also increased both the rate-pressure product and the left ventricular dP/dt in both treated groups (C+D and P+D). Histological infarct size was 12.3(SEM 2.0)% of the area at risk in the untreated control group (n = 11), and was reduced to 4.4(1.7)% in the untreated preconditioning group (n = 8; p < 0.05). Dobutamine increased non-preconditioned infarct size (group C+D) to 22.1(3.4)% (n = 7; p < 0.05). Infarct size in the dobutamine treated preconditioning group (P+D) was not significantly different from infarct size in group P (n = 8), at 6.1(2.5%).

CONCLUSIONS

In preconditioned hearts, dobutamine restored postischaemic contractile function but did not increase infarct size significantly. Thus reduced contractile effort is not required for the cardioprotective effect on ischaemic preconditioning.

Structure of 85 kDa subunit of human phosphatidylinositol 3-kinase analyzed by using monoclonal antibodies

An 85 kDa subunit (p85 alpha) of phosphatidylinositol 3-kinase (PI-3K) has one SH3 and two SH2 regions [SH2(N) and SH2(C)], which direct protein-protein interaction. We have established eighteen hybridomas producing monoclonal antibodies against p85 alpha to study the structure-function relationship of this protein. Epitope mapping using a series of deletion mutants expressed in E. coli showed that the monoclonal antibodies bound to at least 5 distinct epitope regions, which were well dispersed on p85 alpha except for its carboxyl-terminus. Monoclonal antibodies against amino-terminal regions and polyclonal antibodies against carboxyl-terminal regions immunoprecipitated p85 alpha expressed in human cells and in E. coli. On the other hand, monoclonal antibodies against the central part of p85 alpha failed to immunoprecipitate p85 alpha efficiently; however, they could immunoprecipitate p85 alpha mutants with deletion of either the amino- or the carboxyl-terminal region. Similar results were obtained by immunocytochemistry using confocal microscopy. These results suggested that steric hindrance prevents binding of monoclonal antibodies to the central part of p85 alpha where SH2(N) is located. The SH2(N) may have a distinct function from SH2(C), which is located at the carboxyl-terminal region and has been shown to mediate the binding of PI-3K to activated growth factor receptors.

Effects of physical exercise on the elasticity and elastic components of the rat aorta

To evaluate the effects of exercise on aortic wall elasticity and elastic components, young male rats underwent various exercise regimes for 16 weeks. In the exercised rats, the aortic incremental elastic modulus decreased significantly when under physiological strain. The aortic content of elastin increased significantly and the calcium content of elastin decreased significantly in the exercised group. The accumulated data from the exercised and sedentary groups revealed that the elastin calcium content was related positively to the incremental elastic modulus. We concluded that physical exercise from an early age decreases the calcium deposit in aortic wall elastin and that this effect probably produced in the exercised rats a distensible aorta.

Pitfalls in fine needle aspiration cytology of breast tumors. A report of two cases

Two cases of fibroadenoma that were cytologically misdiagnosed as mucous carcinoma are reported. The reason for this misdiagnosis was the presence of mucus in the background of the smears. Cytologically, even if plenty of mucus is present in a smear, careful observation of the content of the mucus is necessary. A group of stromal cells in mucus or of epithelial cells dissociated from mucus suggests fibroadenoma with a mucous change in the fibromatous tissue.

Structural requirement of CRK SH2 region for binding to phosphotyrosine-containing proteins. Evidence from reactivity to monoclonal antibodies

The SH2 region of signal-transducing proteins mediates binding to phosphotyrosine-containing proteins. We analyzed the structure-function relationship of the SH2 region of the human CRK protein by using a series of monoclonal antibodies (mAbs). Seventeen mAbs against the CRK SH2 region were classified into 5 groups according to the reactivity with mutant CRK proteins expressed in COS7 cells and in Escherichia coli and by epitope scanning with synthetic nonapeptides. Two groups of mAbs (groups A and B) were reactive only with intact SH2. Mutation(s) in either the amino-terminal B box or the carboxyl-terminal C box, which are the two subdomains of SH2, abolished the reactivity of the CRK mutants to the mAbs of groups A and B. Group A mAbs competed the binding of the CRK SH2 region to the phosphotyrosine-containing proteins. Moreover, the spectrum of the CRK mutants which were recognized by group A mAbs coincided with that of the CRK mutants which could bind phosphotyrosine-containing proteins, suggesting that group A mAbs were directed against the site of binding to phosphotyrosine-containing proteins. Group C mAbs, directed against the region between the B and C boxes, were reactive with both wild-type and mutant CRK proteins and did not affect the capacity of SH2 to bind phosphotyrosine-containing proteins. Contrary to group A and B mAbs, mAbs belonging to groups D and E, which were mapped onto the C box, did not bind well to the native CRK proteins, but bound to CRK mutants with mutation(s) in either the B or the C box. These results suggest that the B and C boxes, which are separated by a hinge region, coordinately form the functional SH2 domain that binds to the phosphotyrosine-containing proteins and to the group A mAbs.

Purification and properties of pyridoxal kinase from bovine brain

A 27,000-fold purification of pyridoxal kinase from bovine brain tissue has been achieved by a combination of ammonium sulfate fractionation, DEAE-cellulose chromatography, hydroxyapatite chromatography, Sephadex G-150 gel filtration, Blue Sepharose CL-6B chromatography, and Phenyl-Superose chromatography. The final chromatography step yields a homogeneous preparation of high specific activity (2105 nmol/min/mg protein). The molecular mass of the native enzyme was estimated to be approximately 80,000 on gel filtration. The subunit molecular mass was determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis to be approximately 39,500. This indicates that pyridoxal kinase is a dimeric enzyme.

Proton magnetic resonance spectroscopy with dementia

To provide new insights into metabolic changes in the brain of patients with dementia, we performed in vivo localized proton magnetic resonance spectroscopy in nine patients with primary degenerative dementia and in three patients with normal-pressure hydrocephalus. We compared the results with those in 26 healthy volunteers. Measurements of regional cerebral blood flow were performed in seven patients by means of single photon emission computed tomography with amphetamine I 123 as a tracer. The magnetic resonance spectra constantly showed three major peaks corresponding to N-acetylaspartate (NAA), creatine and phosphocreatine (Cr), and choline-containing compounds. There were no age-related changes in the mean area ratio of NAA to Cr in neurologically normal volunteers. The NAA/Cr ratio was significantly reduced in patients with primary degenerative dementia. The reduction of the NAA/Cr ratio was observed even in dementia patients with no significant brain atrophy or reduction in regional cerebral blood flow. No significant reduction of the NAA/Cr ratio was seen in patients with normal-pressure hydrocephalus. The NAA/Cr ratio might reflect the number and/or activity of neuronal cells in the brain. Proton magnetic resonance spectroscopy may well provide a useful tool for early detection of, and further pathophysiological study of, primary degenerative dementia.

Chemotherapeutic efficacy of the protein-doxorubicin conjugates on multidrug resistant rat hepatoma cell line in vitro

In vitro studies were initiated to study the antitumour effect of protein-doxorubicin (DXR) conjugate on the growth of the multidrug resistant rat ascites hepatoma cell line, AH66DR. The 50% inhibitory concentration (IC50) for DXR in AH66DR cell line was 16 mumol l-1 (AH66 parental cell line, AH66P, IC50 was 0.08 mumol l-1). Treatment of AH66P and AH66DR cells with various concentrations of DXR or conjugates at equivalent concentrations of DXR was performed. The two types of conjugates used were bovine serum albumin (BSA)-DXR conjugate and immunoglobulin G (IgG)-DXR conjugate. Both of these conjugates showed potent dose-dependent inhibition of cell growth against AH66DR cells as compared with the cells treated with DXR or other controls. The IC50 for BSA-DXR and IgG-DXR conjugates in AH66DR cell line was 0.05 (equivalent DXR) mumol l-1 and 0.07 (equivalent DXR) mumol l-1, respectively. These values were similar to that of the AH66P treated with DXR. Cellular uptake and accumulation of DXR or BSA-DXR conjugate was also quantitated in both cell lines. The cellular concentration of DXR in AH66DR cells was 2-fold lower than that of AH66P cells throughout the experiment. In contrast, by the treatment of AH66DR cells with BSA-DXR conjugate, the intracellular drug concentration increased as a function of time up to 24 h (639.1 +/- 41.8, equivalent DXR, ng 10(-5) cells) and reached the same drug level as AH66P cells treated with DXR (617.9 +/- 17.3 ng-5 cells). Ammonium chloride treatment inhibited the effects of the conjugates but did not inhibit the free drugs. Intracellular DXR was effluxed rapidly from AH66DR cells, but BSA-DXR conjugate remained in the cells at relatively high concentration for a long time. These results indicate that by chemically modifying DXR, such as by conjugation of the drug with proteins, it may be possible to overcome multidrug resistance.

CD3 down-regulating factor in sera and culture supernatants of leukaemic cells from patients with adult T cell leukaemia

Immunological abnormality of T lymphocytes in patients with adult T cell leukemia (ATL) is characterized by abnormal expression of the 55 kD chain of the receptor for interleukin 2 (IL-2R/p55) (Tac), and the down-regulation of CD3 expression. Using serum and culture supernatants of leukaemic cells from ATL patients (Group A) whose CD3 expression was down-regulated and those (Group B) whose CD3 was not low, the possible mechanism of CD3 down-regulation on ATL cells was discussed. When PBMC from normal individuals were cultured with sera from ATL patients for 24 h, CD3 expression revealed by mean fluorescent intensity (MFI) was down-regulated by sera from ATL patients in Group A (MFI: Pt 1 = 51.6 +/- 4.5, Pt 2 = 48.0 +/- 6.9, control = 96.5 +/- 6.6), not by sera from patients in Group B (MFI: Pt 3 = 105.5 +/- 7.9, Pt 4 = 102.5 +/- 8.3, control = 96.5 +/- 6.6). When normal PBMC were cultured with supernatants of leukaemic cells from ATL patients in Group A, this CD3 down-regulating activity was also detected (MFI: Pt 1 = 78.0 +/- 10.2, Pt 2 = 70.6 +/- 8.7, control = 94.0 +/- 6.6). By using gel-chromatography, the fractionated supernatants from ATL patients in Group A decreased CD3 expression of normal PBMC significantly (MFI: Pt = 22.9 +/- 5.8, Pt 2 = 28.8 +/- 7.4, control = 92.1 +/- 9.6). This CD3 down-regulating activity in fractionated supernatant was not inhibited by any lymphokine antibodies, anti-IL-1 alpha antibody (Ab), anti-IL-1B Ab, anti-IL-2 Ab, anti-IL-3 Ab, anti-IL-4 Ab, anti-IL-6 Ab, anti-TNF-alpha Ab and anti-IFN-gamma Ab. Any known cytokines (IL-1, IL-2, IL-3, IL-4, IL-6, TNF-alpha and IFN-gamma) could not modulate CD3 expression of normal PBMC. These findings suggested that there are novel factor(s) with CD3 down-regulating activity in the serum and culture supernatant of ATL patient and those factor(s) are involved in progression of ATL.

Cytotoxic effect of the protein-doxorubicin conjugates on the multidrug-resistant human myelogenous leukemia cell line, K562, in vitro

In vitro studies were performed to examine the antitumor effect of protein-doxorubicin (DXR) conjugate on the growth of the multidrug-resistant human chronic myelogenous leukemia cell line, K562/DXR. The 50% inhibitory concentration (IC50) for DXR in the K562/DXR cell line was 20 nM (in the K562 parental cell line, IC50 was 3.2 nM). Treatment of both types of cells with various concentrations of DXR or conjugates at equivalent concentrations of DXR was carried out. One type of the conjugates used was human serum albumin (HSA)-DXR conjugate and human transferrin (Tf)-DXR conjugate via a glutaraldehyde bridge (HSA-ga-DXR, Tf-ga-DXR, respectively) and another type used was HSA-DXR conjugate with a dextran bridge (HSA-dex-DXR). All of these conjugates showed potent dose-dependent inhibition of cell growth against the K562/DXR cells as compared with the cells treated with DXR or other controls. IC50 for HSA-ga-DXR, Tf-ga-DXR and HSA-dex-DXR conjugates in the K562/DXR cell line was 2.4, 3.6 and 1.0 (equivalent DXR) nM, respectively, which were approximately similar to the value of the K562 treated with DXR. Through the treatment of K562/DXR cells with HSA-DXR conjugate, the intracellular drug concentration increased as a function of time up to 24 h compared with the cells treated with DXR. Intracellular DXR effluxed rapidly from K562/DXR cells, but HSA-ga-DXR as well as HSA-dex-DXR conjugates remained in the cells at a relatively high concentration for a long time. These results indicate that it may be possible to overcome multidrug resistance by chemically modifying DXR, such as by conjugation of the drug with proteins.

Correlation between number of anastomosed vessels and survival rate in finger replantation

In replantation surgery, an attempt is made to repair as many vessels as possible. However, operative procedures might be simplified to reduce the operative time and the number of personnel required. In an attempt to determine the essential number of vascular anastomoses in finger replantation, the correlation between the number of anastomosed vessels and survival rates was examined in 216 replanted fingers that had been completely amputated. Digits with two arteries repaired had higher survival rates than those with only one artery repaired; however, there was no significant difference between survival rates and the number of arterial anastomoses in any of the zones. The number of anastomosed veins was well-correlated statistically with the survival rate. In Zone I (distal to the lunula), there was no significant difference in the survival rates between no venous anastomosis and one to two venous anastomoses. A statistically significant difference between the survival rates with one venous anastomosis and two or three venous anastomoses was observed only in Zone III (middle phalangeal region). These results support the following conclusions: 1) The essential amount of arterial repair appears to be one arterial anastomosis. 2) The essential venous repair appears to be no veins in Zone I, one vein in Zone II (lunula to distal interphalangeal joint), two veins in Zone III, and one vein in Zone IV (proximal phalangeal region).

Fibrinogen Osaka IV: a congenital dysfibrinogenemia found in a patient originally reported in relation to surgery, now defined to have an A alpha arginine-16 to histidine substitution

We discovered a congenital heterozygous dysfibrinogen in a patient and reported this case in relation to surgery some time ago (Jpn J Surg (1988) 18:43-46). Further studies on the isolated abnormal population of fibrinogen derived from this patient have revealed that fibrinopeptide A was not cleaved by ancrod, a snake venom-derived thrombin-like enzyme, but by thrombin, slowly but completely. The released fibrinopeptide A components, being the A, AY, and AP peptides, were all found to be abnormal, as evidenced by slightly earlier elution positions on high-performance liquid chromatography, compared with the normal counterparts. By analyzing their amino acid sequence, we have identified an arginine to histidine substitution at position 16 of the A alpha chain, the thrombin cleavage site. Utilizing insolubilized abnormal fibrinogen, we confirmed that the polymerization site assigned to the central E domain, the "A" site, was exposed by thrombin, but not by ancrod. This dysfibrinogen, designated as fibrinogen Osaka IV, is the second abnormal molecule with an A alpha arginine-16 to histidine substitution identified among Japanese families.

An abnormal protein C (protein C Yonago) with an amino acid substitution of Gly for Arg-15 caused by a single base mutation of C to G in codon 57 (CGG-->GGG). Deteriorated calcium-dependent conformation of the gamma-carboxyglutamic acid domain relevant to a thrombotic tendency

Protein C Yonago is a dysfunctional protein C characterized by defective anticoagulant activity determined by a coagulation assay and normal amidolytic activity measured on a synthetic substrate S-2366 (Iijima et al., Thromb Res 1991;63:249-257). We have identified a single point mutation of C to G in codon 57 (CGG-->GGG) of the gene for protein C Yonago by genetic analysis utilizing the polymerase chain reaction. The mutation should have resulted in an amino acid substitution of Gly for Arg at position 15 of the light chain of mature protein C. No mutations were found in nucleotides spanning the putative gamma-carboxylase recognition site or gamma-carboxyglutamic acid residues of protein C. Protein C Yonago was non-reactive to monoclonal antibodies JTC-1 and -3 that solely recognized the calcium-dependent conformation of the gamma-carboxyglutamic acid domain. This indicated that the mutation had critically perturbed the highly conserved structure of the gamma-carboxyglutamic acid domain. Thus, the calcium-dependent conformation required for the phospholipids binding to exert the physiological functions of protein C may not have been elicited normally in this abnormal protein C, resulting in defective generation of anticoagulant activities in plasma. Consequently, no anticoagulant activities may have been generated in vivo.

Protein characterization of Babesia equi piroplasms isolated from infected horse erythrocytes

Proteins of Babesia equi piroplasms were characterized. The piroplasms of B. equi were purified by lysis of infected horse erythrocytes with N2 gas cavitation followed by separation in Percoll density-gradient centrifugation. The relative molecular weights (Mr) of major proteins separated by two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis were 18, 28, 30, 41, 43, 54, 66.5, and 96 kDa. Immunoblot analysis using serum from an experimentally infected horse revealed six immunodominant proteins of 15, 18, 28, 30, 41, and 96 kDa. Two immunodominant proteins of 18 and 28 kDa were membrane-bound proteins as revealed by Triton X-114 phase partitioning.

Hepatic arterial infusion of interleukin-2 in advanced hepatocellular carcinoma

From August 1988 to February 1991, we performed hepatic arterial cannulation after tumor mass reduction in 17 patients with advanced hepatocellular carcinoma. By a subcutaneous infusion pump the patient received a continuous infusion of interleukin-2 (IL-2) (0.35 x 10(6) Japanese Reference Unit/day) and intermittent chemoembolization with 10 mg doxorubicin emulsion. The longest period of IL-2 infusion was 32 months. In 3 patients, the IL-2 dose could not be increased to the planned level due to fever or jaundice. Eight patients received the infusion for more than 10 months. NK and LAK activity in the peripheral blood, which had been reduced after partial liver resection, arterial embolization, or ethanol injection, was enhanced significantly by the IL-2 infusion, and the levels remained high for about 8 to 10 months. During periods of high NK and LAK activity, direct effects on the liver tumors were observed. In 11 patients who received IL-2 infusion for more than 6 months there was CR in 4, PR in 2, NC in 3 and PD in 2. Thereafter, however, the levels of NK and LAK activity decreased despite increase in the IL-2 dose, and sudden appearance of metastatic tumors caused deterioration of the patients. The 1-year and 2-year cumulative survival rates were 41% and 16% respectively. Further studies are required to explore ways for longer-lasting enhancement of NK and LAK activity.

[A new technique for evaluating the respiratory tract--digital subtraction bronchography (DSBG)]

Bronchography is essential for evaluation of morphological changes in the bronchial tree. However, conventional bronchography using Propyliodone (Dionosil) is extremely invasive, especially to those with pulmonary infections. In the present study, we developed a new less invasive method of bronchography with the aid of digital subtraction technique (DSBG), and evaluated its clinical benefits. Bronchography was performed by injecting contrast medium (Iopamidol: Iopamiron 300) via the lumen of the bronchoscope (Olympus Type 20), and image processing of the respiratory tract was performed using digital subtraction technique. From 1991 to 1992, DSBG was performed in 15 cases (8 bronchiectasis, 1 diffuse panbronchiolitis, 1 lung cancer, 1 pulmonary emphysema, and 4 others). DSBG clearly demonstrated the morphological changes of large and segmental bronchial lesions in cases of bronchiectasis and lung cancer, as well as conventional bronchography using Dionosil. In addition, it was possible to image the morphological changes of bronchiolar lesions in diffuse panbronchiolitis and pulmonary emphysema to the same detail as obtained using classical selective alveolo-bronchography (SAB). Since DSBG can provide enhanced images the bronchial tree without being affected by cardiac and respiratory movements, we could obtain detailed information on bronchial and/or bronchiolar lesions. With respect to side effects, Iopamiron was quickly drained and/or absorbed within 2 hours after injection. Pulmonary infection and bronchial bleeding, which are well known primary complications of classical bronchography using Dionosil, were not observed. We conclude that 1) DSBG is useful new technique for examining morphological changes of the respiratory tract, and 2) DSBG is less invasive than conventional bronchography.

Adhesion of cerebral endothelial cells to lymphocytes from patients with multiple sclerosis

To investigate the factors regulating the entry of lymphocytes into the brain, we assessed the adhesion in vitro of 51Cr labelled lymphocytes from peripheral blood of patients with multiple sclerosis (MS) to human cerebral endothelial cells, and evaluated the effect on the adhesion of endothelium activated by interferon-gamma (IFN-gamma), lipopolysaccharides (LPS), interleukin-1 (IL-1) and tumor necrosis factor (TNF). Patients with acute relapsing MS during an exacerbation showed significant increase in MNC adherence to cerebral endothelial cells as compared with controls (p < 0.001). MNC adherence to cerebral endothelial cells activated by IFN-gamma or LPS, was significantly increased as compared to the controls (p < 0.01). MNC adherence to endothelial cells was not blocked by antibodies against the intercellular adhesion molecule-1 (ICAM-1), but was blocked by lymphocyte function-associated antigen-1 (LFA-1). The increased adherence observed in patients with acute relapsing MS during an exacerbation would modulate the migration of lymphocytes across the blood-brain barrier (BBB).

Suppression of spontaneous development of uterine adenomyosis and mammary hyperplastic alveolar nodules by Chinese herbal medicines in mice

The effects of traditional Chinese herbal remedies, Shakuyaku-kanzo-to (SKT) and Hachimijiou-gan (HJG), on the spontaneous development of uterine adenomyosis and mammary hyperplastic alveolar nodules (HAN) were examined in an experimental animal model using SHN strain of mice. Female mice were provided with the chow containing 1% of SKT or HJG during 25-150 days of age. At 150 days of age, SKT treatment showed significantly lower incidence of adenomyosis, and HJG treatment resulted in a significantly lower incidence of HAN when compared to a control chow containing no medicines. Long-term exposure to these herbal medicines affected little serum prolactin (PRL) level, estrous cycle, food intake and body growth. Thus, the present mouse data suggest that the oral administration of these herbal medicines is a useful tool for the treatment of uterine adenomyosis or mammary disorder such as cystic mastitis.

The indications for tumor mass reduction surgery and subsequent multidisciplinary treatments in stage IV hepatocellular carcinoma

The indications for tumor-mass reduction surgery and subsequent immunotherapy in patients with stage IV hepatocellular carcinoma (HCC) were elucidated in this study. About 42% of the resected specimens from stage IV-A patients (n = 26) contained well-differentiated multicentrically occurring HCC, which was not found in any of the stage IV-B patients (n = 9). The 2-year survival rate after reduction surgery was 49% for the stage IV-A patients and only 13% for the stage IV-B patients, while 6 of the stage IV-A patients who survived for more than 2 years had no vascular invasion or distant organ metastases. Some of the stage IV patients maintained normal peripheral natural killer (NK) activity and were also able to tolerate surgical insults immunologically, provided that appropriate postoperative immunotherapy was given. Thus, stage IV-A HCC has a greater possibility of containing slow-growing intrahepatic tumor clusters, and the removal of any rapidly growing tumors from among these should be undertaken by reduction surgery followed by subsequent multidisciplinary treatment for residual tumor cells, including appropriate immunotherapy.

Reversible interactions between plasminogen activators and plasminogen activator inhibitor-1

We have shown that the urokinase (UK) kringle domain contains a high-affinity plasminogen activator inhibitor-1 (PAI-1) binding site, responsible for the 10-fold faster complex formation between UK and PAI-1 than between PAI-1 and low-molecular-weight urokinase (LMWUK). Complex formation between UK and PAI-1, but not between LMWUK and PAI-1, was suppressed 10-fold in the presence of peptide U-107 derived from the UK kringle domain. Peptide U-373 derived from the UK catalytic domain slowed complex formation between UK and PAI-1 and also LMWUK and PAI-1. Inactivation of tissue-type plasminogen activator (tPA) by PAI-1 was slowed 10-fold in the presence of peptides derived from the tPA finger and kringle-2 domains. DFP-inactivated (DIP) UK and both forms of DIP-tPA inhibited PAI-1 binding to U-107 and to U-373 whereas single-chain urokinase-type PA (scuPA) was unable to compete with either peptide for PAI-1 binding. These data suggest that the reversible PAI-1 binding site in the UK A-chain plays a role in the rapid association with PAI-1 as important as those that reside in the tPA A-chain and that reversible PAI-1 binding sites are expressed on the surface of UK upon conversion from scuPA, in contrast to tPA.