Growth factor receptors are differentially expressed in cancers of the papilla of vater and pancreas

OBJECTIVE

To compare growth factor receptor expression in papilla of Vater cancer and pancreatic cancer.

SUMMARY BACKGROUND DATA

Cancer of the papilla of Vater has a much better prognosis than pancreatic cancer. Earlier symptoms may result in earlier diagnosis, but different biologic growth behaviors and genetic alterations might also be explanations.

PATIENTS AND METHODS

Surgical specimens from papilla of Vater cancers (24 patients) and pancreatic cancers (80 patients), normal papilla of Vater tissues (20 patients), and normal pancreatic tissues (24 patients) were frozen and fixed. The authors compared the expression of the epidermal growth factor receptor (EGFR) and c-erbB2 and c-erbB3 by Northern blot, in situ hybridization, and immunohistochemistry.

RESULTS

In papilla of Vater cancer, Northern blots showed comparable EGFR and c-erbB2 mRNA expression but significantly lower c-erbB3 mRNA levels than in normal papilla. In pancreatic cancer, mRNA expression was enhanced compared with normal controls for EGFR (4-fold), c-erbB2 (2.5-fold), and c-erbB3 (5.2-fold). In situ hybridization confirmed this and showed mRNA expression only in cancer cells. EGFR immunohistochemical staining scores were comparable in papilla of Vater cancer (1.17 +/- 0.22) and normal papilla (1.42 +/- 0.25). Staining scores for c-erbB2 (2.72 +/- 0.40 vs. 3.89 +/- 0.37) and c-erbB3 (2.78 +/- 0.35 vs. 3.89 +/- 0.53) were slightly lower than controls in papilla of Vater cancer. In pancreatic cancer, immunostaining scores for EGFR, c-erbB2, and c-erbB3 were significantly higher than controls.

CONCLUSION

Members of the EGFR family show similar or lower expression in papilla of Vater cancer than in normal controls. In pancreatic cancer, these receptors are upregulated. This supports the hypothesis that papilla of Vater cancer and pancreatic cancer have biologic differences that may contribute to the different growth of these tumors.

Inhibition of the generation of thrombin and factor Xa by a fucoidan from the brown seaweed Ecklonia kurome

The effects of a fucoidan (C-II), which was purified from the brown seaweed Ecklonia kurome, on the generation of thrombin and factor Xa have been investigated by measuring the amidolytic activities by using the respective specific chromogenic substrates in both plasma and purified systems. C-II inhibited significantly the generation of thrombin in both the intrinsic and the extrinsic pathways, although the intrinsic inhibitory effect by C-II was more remarkable than the extrinsic one. On the other hand, C-II was a good inhibitor of the factor Xa generation in the intrinsic pathway, while it was a poor one in the extrinsic pathway. In the purified systems C-II also inhibited the formation of prothrombin-activating complex (i.e., prothrombinase), but not its activity. The concentration of C-II required for 50% inhibition of thrombin generation was about one-tenth to one-seventh of that of the activity of the generated thrombin in plasma. These results indicate that C-II has an inhibitory effect on the generation of thrombin by blocking the formation of prothrombinase and by preventing the generation of intrinsic factor Xa in addition to its antithrombin activity, and also that the generation-inhibitory effect is more remarkable than C-II's enhancement effect on the antithrombin activity by heparin cofactor II in plasma.

Concomitant analysis of the epidermal growth factor receptor family in esophageal cancer: overexpression of epidermal growth factor receptor mRNA but not of c-erbB-2 and c-erbB-3

The epidermal growth factor receptor family consists of four closely related transmembrane receptors: epidermal growth factor receptor (EGF-R), c-erbB-2, c-erbB-3, and c-erbB-4. Overexpression of each receptor may lead to cell transformation and contributes to tumor progression in various malignancies. Although these factors have been analyzed in many cancers separately, little is known about their concomitant expression in esophageal cancer. Based on the finding that EGF-R and c-erbB-2 form highly active transmembranous heterodimers that enhance cell growth and proliferation, we used Northern blot analysis and immunohistochemistry to analyze the concomitant expression of EGF-R, c-erbB-2, and c-erbB-3 in tissue samples obtained from 39 patients undergoing esophagectomy for esophageal cancer. Northern blot analysis revealed a fourfold increase (p < 0.01) in EGF-R mRNA levels in the esophageal cancer samples in comparison with normal tissue samples. The c-erbB-2 receptor was only 1.25-fold elevated in the esophageal cancers, which failed to be statistically significant (p = 0.31). In contrast, c-erbB-3 mRNA levels were 3.5-fold lower (p < 0.01) in the esophageal cancers than in the normal tissues. Immunohistochemical analysis showed weak EGF-R, c-erbB-2, and c-erbB-3 immunostaining in the normal esophageal tissue. In esophageal cancer samples, immunoreactivity for EGF-R, c-erbB-2, and c-erbB-3 was mainly located in the cancer cells. Strong EGF-R, c-erbB-2, and c-erbB-3 immunoreactivity was present in 59%, 64%, and 64% of the esophageal cancer samples, respectively. In consecutive tissue sections, identical cancer cell clusters often exhibited these three closely related receptors simultaneously. However, correlation of the immunohistochemical findings with the clinicopathologic patient parameters revealed that the presence of EGF-R, c-erbB-2, or c-erbB-3 had no influence on patient survival (p > 0.05). In addition, the simultaneous presence of these receptors did not influence survival. Our findings indicate that in esophageal cancer the presence of EGF-R, c-erbB-2, and c-erbB-3 alone or in combination seems to have no major influence on patient prognosis and does not alter tumor growth behavior significantly.

Molecular cloning and expression of the Na+/H+ exchanger gene in Oryza sativa

Na+/H+ exchanger catalyzes the countertransport of Na+ and H+ across membranes. We isolated a rice cDNA clone the deduced amino acid sequence of which had homology with a putative Na+/H+ exchanger in Saccharomyces cerevisiae, NHX1. The sequence contains 2330 bp with an open reading frame of 1608 bp. The deduced amino acid sequence is similar to that of NHX1 and NHE isoforms in mammals, and shares high similarity with the sequences within predicted transmembrane segments and an amiloride-binding domain. The expression of the gene was increased by salt stress. These results suggest that the product of the novel gene, OsNHX1, functions as a Na+/H+ exchanger, and plays important roles in salt tolerance of rice.

[Induction of molecular chaperones HSP70 and HSP90 in rat liver cytosol by a highly toxic coplanar PCB]

We report here that a highly toxic coplanar polychlorinated biphenyl (PCB), 3,3',4,4',5-pentachlorobiphenyl (PenCB) induces molecular chaperones, HSP70 and HSP90 in liver cytosol of rats. Male Wistar rats received PenCB in corn oil once at a dose of 25 mg/kg i.p. Pair-fed control groups were treated with the vehicle and given the amount of chow matched with that taken by the PenCB-treated animals, and free-fed controls were given the vehicle. The liver cytosolic HSP70 level in rats treated with PenCB was 5-fold higher than those in free-fed controls, though that for pair-fed controls was approximately 2-fold higher than that in free-fed controls. The liver cytosolic HSP90 alpha and HSP90 beta levels were also higher in PenCB-treated rats than in both control groups, but the induction extent was lesser than that for HSP70. Inductive effect on the chaperones was examined with a single different dose of PenCB 0, 0.5, 1.0, 5.0, 10 and 25 mg/kg. Marked induction of the HSP70 level was observed with a minimum dose of PenCB 0.5 mg/kg. The HSP90 alpha level was induced with PenCB-dose dependent manner although the HSP90 beta induction was greatest with a dose of PenCB 5.0 mg/kg. HSP70 and HSP90 are essential for cells under normal conditions and act as molecular chaperones. HSP90 is well known to modulate the function of sex steroid hormone or aromatic hydrocarbon receptors while HSP70 is required for receptor-HSP90 heterocomplex assembly. The role of molecular chaperones may be involved in the endocrine disrupting properties of coplanar PCB and dioxins.

[A case of hypertensive intracerebral hemorrhage associated with ipsilateral internal carotid artery occlusion]

We report a case of intracerebral hemorrhage associated with ipsilateral internal carotid artery occlusion. The patient was a 54-year-old man, who developed a small cerebral hemorrhage in the left internal capsule. He was admitted with mild right hemiparesis to out hospital. Left carotid angiography showed an occlusion at the origin of the internal carotid artery. Right cerebral angiography revealed the slow filling of cerebral arteries of left hemisphere by the cross flow. He was treated conservatively. Two days after admission, the neurological examination revealed no notable abnormalities. The etiology of hemorrhage of this case is presumed as the arterial necrosis due to hypertension. There has been no report on the intracerebral hemorrhage associated with ipsilateral internal carotid artery occlusion. Our case suggests that the volume and enlargement of cerebral hemorrhage may be influenced by cerebral perfusion pressure.

Membrane deinsertion of SecA underlying proton motive force-dependent stimulation of protein translocation

The proton motive force (PMF) renders protein translocation across the Escherichia coli membrane highly efficient, although the underlying mechanism has not been clarified. The membrane insertion and deinsertion of SecA coupled to ATP binding and hydrolysis, respectively, are thought to drive the translocation. We report here that PMF significantly decreases the level of membrane-inserted SecA. The prlA4 mutation of SecY, which causes efficient protein translocation in the absence of PMF, was found to reduce the membrane-inserted SecA irrespective of the presence or absence of PMF. The PMF-dependent decrease in the membrane-inserted SecA caused an increase in the amount of SecA released into the extra-membrane milieu, indicating that PMF deinserts SecA from the membrane. The PMF-dependent deinsertion reduced the amount of SecA required for maximal translocation activity. Neither ATP hydrolysis nor exchange with external SecA was required for the PMF-dependent deinsertion of SecA. These results indicate that the SecA deinsertion is a limiting step of protein translocation and is accelerated by PMF, efficient protein translocation thereby being caused in the presence of PMF.

Induction of a cytosolic 54 kDa protein in rat liver that is highly homologous to selenium-binding protein

We have previously shown that a 54 kDa protein in rat liver is highly homologous to selenium-binding protein (SeBP) or acetaminophen-binding protein (APBP) in mice and is highly inducible by treatment with 3,3',4,4',5-pentachlorobiphenyl or 3-methylcholanthrene. In this study, we examine the effect of six typical inducers, 3-methylcholanthrene (MC), isosafrole (ISO), phenobarbital (PB), dexamethasone (DEX), clofibrate (CLO), pyrazole (PYR) and butylated hydroxytoluene (BHT), on the expression level of this 54 kDa protein. Male Wistar rats were given each inducer following a predetermined schedule. Among these inducers, the 54 kDa protein was inducible by MC and BHT. The response to MC and BHT was compared with that of NAD(P)H: quinone oxidoreductase and ethoxyresorufin O-deethylase activities. The induction mechanisms and physiological role of the 54 kDa protein are discussed in the light of our results.

Simultaneous optical imaging of intracellular Cl- in neurons in different layers of rat neocortical slices: advantages and limitations

Simultaneous recording of changes in intracellular Cl- concentration ([Cl-]i) in individual neurons situated in different layers (e.g. II/III-VI) of neocortical slices was found to be feasible by means of optical fluorescence measurements using 6-methoxy-N-ethylquinolinium iodide (MEQ). Gamma-aminobutyric acid (GABA) caused a measurable increase in [Cl-]i in adult neocortical neurons, but a decrease in immature neurons. Developmental changes in the function of the Cl- pump and cation-Cl- co-transporters were evaluated using inhibitors such as furosemide (FURO), ethacrynic acid (ETA), and bumetanide (BMT). However, it was found that these inhibitors absorb and/or emit light of the wavelength that is used for the optical imaging of MEQ. In addition, quenching of MEQ fluorescence by Cl- and leakage of loaded MEQ was significantly enhanced at a higher temperature, which will limit experimentation at > 30 degrees C. Estimation of [Cl-]i in individual neurons in slices was made possible by calibrating intracellular MEQ fluorescence signals at known Cl- concentrations ([Cl-]) in the presence of tributyltin, a Cl(-)-OH- antiporter, nigericin, a K+-H+ antiporter, and KSCN. This enables comparison of [Cl-]i between neurons in different slices. Thus, optical imaging of [Cl-]i in brain slices can provide valuable spatial information about [Cl-]i dynamics and homeostasis, although it should be emphasized that the technique does have some limitations.

Astrocytes are more vulnerable than neurons to cellular Ca2+ overload induced by a mitochondrial toxin, 3-nitropropionic acid

The differential effects of 3-nitropropionic acid on cultured neurons and astrocytes (of cortical and striatal origin) were examined by studying intracellular Ca2+ changes using imaging techniques with fura-2. The neurons and astrocytes whose intracellular Ca2+ concentration was recorded were identified later by immunocytochemical staining for microtubule-associated protein 2 and glial fibrillary acidic protein, respectively. 3-Nitropropionic acid (1.7 mM) irreversibly increased intracellular Ca2+ in astrocytes (27%) and, to a significantly smaller extent, in neurons (10%). The latency to onset of the intracellular Ca2+ increase was longer in neurons (45 min) than in astrocytes (29 min). Thus, a differential susceptibility of astrocytes and neurons was observed. The 3-nitropropionic acid-induced astrocytic and neuronal Ca2+ accumulations were both due to influx of Ca2+, as the increases were absent in Ca2+-free medium. An inhibitor of the Na+-Ca2+ exchanger (2',4'-dichlorobenzamil), greatly reduced the intracellular Ca2+ increase in astrocytes, but not in neurons. This indicates that the intracellular Ca2+ increase in astrocytes is primarily mediated by a reverse operation of the Na+-Ca2+ exchange system, whereas in neurons it is mediated by a different mechanism. In addition, we noted that astrocytic cell death occurred in 9% of cells at 60 min or more after the start of a 40 min perfusion with 3-nitropropionic acid, while only 4% of neurons died. In astrocytes, cell death was preceded by blebbing of the cell membrane, and by a sustained increase in intracellular Ca2+ followed by an abrupt further elevation occurring just before cellular collapse. The present results indicate that astrocytes are more vulnerable than neurons to 3-nitropropionic acid-induced cellular Ca2+ overload and toxicity, and hence support the hypothesis that, in part, 3-nitropropionic acid-induced neurotoxicity could be secondary to astrocytic cell death caused by Ca2+ overload.

Severe respiratory distress following sodium oleate ingestion

CASE REPORT

Oleic acid and oleate are pulmonary toxins used to create laboratory models of acute respiratory distress syndrome, but there is little information on human toxicity. We report the intentional ingestion of 50 mL sodium oleate 20% by a 22-year-old woman with no symptoms for the first 2 days after ingestion. Her respiratory status deteriorated rapidly on day 3 progressing to acute respiratory distress syndrome (PaO2/FIO2 < 100 mm Hg) on day 4. Treatment with high-dose steroids and intensive respiratory support including high-frequency jet ventilation were associated with gradual but complete recovery by day 39. The delayed onset of symptoms suggested that the lung injury was due to the systemic circulation of oleate to the lungs rather than to direct aspiration. In oral poisoning by sodium oleate, the lung is the first and most lethally affected target organ in humans. This case demonstrates that ingestion of a relatively small amount of sodium oleate can cause delayed, progressively severe, lung injury.

The plasminogen activator/plasmin system is up-regulated after acute necrotizing pancreatitis in human beings

BACKGROUND

Proteolysis and formation of new extracellular matrix components are important mechanisms in tissue remodeling and repair. In this study we analyzed the expression and distribution of the urokinase plasminogen activator (uPA), its membrane receptor (urokinase plasminogen activator receptor [uPAR]), and its inhibitor (plasminogen activator inhibitor-1 [PAI-1]) in acute necrotizing pancreatitis in human beings. In addition, we studied the concomitant expression of transforming growth factor-beta-1 (TGF-beta 1), which is activated by uPA from its precursor and is a potent regulator and stimulator of formation of extracellular matrix.

METHODS

With immunohistochemistry and Northern blot analysis, the expression and cellular distribution of uPA, uPAR, PAI-1, and TGF-beta 1 were determined in 12 normal pancreata obtained from organ donors and 12 pancreatic tissues obtained from patients undergoing operation because of complications of acute necrotizing pancreatitis.

RESULTS

Northern blot analysis showed enhanced expression of uPA, uPAR, and PAI-1 in eight of 12, seven of 12, and nine of 12 necrotizing pancreatitis samples, respectively, compared with normal control samples. In addition, increased TGF-beta 1 mRNA expression was present in eight of 12 necrotizing pancreatitis samples. In contrast, amylase mRNA expression was markedly decreased in the samples of acute necrotizing pancreatitis. Immunohistochemistry revealed elevated uPA, uPAR, and PAI-1 immunoreactivity in the remaining acinar and ductal cells adjacent to the necrotic tissue areas. In contrast, acinar and ductal cells that were located farther from pancreatic necrosis exhibited less uPA and uPAR immunoreactivity. A similar staining pattern in samples of necrotizing pancreatitis was found for TGF-beta 1.

CONCLUSIONS

Up-regulation of uPA and uPAR, which activate proteolysis, might create a milieu that enhances lysis and removal of pancreatic necrosis. The increase in TGF-beta 1 might result from the enhanced catalytic conversion of its precursors by uPA, which subsequently might stimulate formation of extracellular matrix, formation of granulation tissue, and fibrosis.

The Tokyo subway sarin attack: disaster management, Part 1: Community emergency response

The Tokyo subway sarin attack was the second documented incident of nerve gas poisoning in Japan. Prior to the Tokyo subway sarin attack, there had never been such a large-scale disaster caused by nerve gas in peacetime history. This article provides details related to how the community emergency medical services (EMS) system responded from the viewpoint of disaster management, the problems encountered, and how they were addressed. The authors' assessment was that if EMTs, under Japanese law, had been allowed to maintain an airway with an endotracheal tube or use a laryngeal mask airway without physician oversight, more patients might have been saved during this chemical exposure disaster. Given current legal restrictions, advanced airway control at the scene will require that doctors become more actively involved in out-of-hospital treatment. Other recommendations are: 1) that integration and cooperation of concerned organizations be established through disaster drills; 2) that poison information centers act as regional mediators of all toxicologic information; 3) that a real-time, multidirectional communication system be established; 4) that multiple channels of communication be available for disaster care; 5) that public organizations have access to mobile decontamination facilities; and 6) that respiratory protection and chemical-resistant suits with gloves and boots be available for out-of-hospital providers during chemical disasters.

The Tokyo subway sarin attack: disaster management, Part 2: Hospital response

The Tokyo subway sarin attack was the second documented incident of nerve gas poisoning in Japan. The authors report how St. Luke's Hospital dealt with this disaster from the viewpoint of disaster management. Recommendations derived from the experience include the following: Each hospital in Japan should prepare an emergent decontamination area and have available chemical-resistant suits and masks. Ventilation in the ED and main treatment areas should be well planned at the time a hospital is designed. Hospital disaster planning must include guidance in mass casualties, an emergency staff call-up system, and an efficient emergency medical chart system. Hospitals should establish an information network during routine practice so that it can be called upon at the time of a disaster. The long-term effects of sarin should be monitored, with such investigation ideally organized and integrated by the Japanese government.

The Tokyo subway sarin attack: disaster management, Part 3: National and international responses

The authors report the national and international responses to the disaster produced by the Tokyo subway sarin attack. From a worldwide historical perspective, there had never been such a large-scale disaster caused by nerve gas during peacetime. Therefore, this event should be studied from various viewpoints in cooperation with members of the international community. To this end, the Japanese government should help coordinate a large-scale and detailed investigation of the Tokyo subway sarin attack, including the long-term effects of sarin. The authors also recommend that the Japanese Self Defense Forces should be used more effectively in large-scale disasters. The system of direct control of disaster management by the Japanese government could be useful in a large-scale disaster.

Over-expression of glutathione S-transferase Yp isozyme and concomitant down-regulation of Ya isozyme in renal cell carcinoma of rats induced by ferric nitrilotriacetate

An iron chelate, ferric nitrilotriacetate (Fe-NTA), induces renal proximal tubular damage, a consequence of iron-catalysed Fenton-like reactions, that finally leads to a high incidence of renal cell carcinoma (RCC) in rodents. Glutathione S-transferase (GST) is a family of enzymes that play an important role in detoxification of hydrophobic and electrophilic molecules, and has been associated with putative preneoplastic foci of rat hepatocarcinogenesis and chemotherapy-resistance of human cancers. Our previous study revealed an induction of pi-class glutathione S-transferase (Yp) mRNA in the kidney 3 h after administration of Fe-NTA. In the present study, expression of GST isozymes were further investigated in the Fe-NTA-induced RCCs of rats which are characterized by (1) high incidence of metastasis and invasion, (2) high incidence of tumour-associated mortality, and (3) possible involvement of reactive oxygen species in carcinogenesis. In the Fe-NTA-induced RCCs, the levels of alpha-class GST (Ya) mRNA and proteins were markedly decreased with no apparent change in the copy number of the gene. In contrast, GST-Yp mRNA and proteins were significantly increased in the RCCs while the total GST enzymatic activity was decreased. Immunohistochemical analysis revealed intense staining of GST-Yp not only in the primary RCCs and its metastatic sites, but also in their non-tumorous part of proximal tubules. The contrastive expression of GST isozymes in this renal carcinogenesis model suggests an alteration of its transcription mechanisms and warrants further investigation of this particular detoxifying enzyme from the viewpoint of reactive oxygen species-induced carcinogenesis.

Herpes simplex virus hepatitis in macrophage-depleted mice: the role of massive, apoptotic cell death in pathogenesis

Infection with herpes simplex virus or hepatitis viruses can lead to fulminant hepatitis, but there is controversy about the underlying conditions needed for such disease. To investigate how the impairment of host defences might be involved, macrophages were depleted by administration of silica to mice before intravenous injection with herpes simplex virus type 1 (HSV-1). Such mice died rapidly and their livers were yellowish and shrunken (acute yellow atrophy), and occasionally grossly haemorrhagic. Small foci of apoptotic cells developed in the liver lobules; these rapidly became confluent and zonal over time. The overall lesion pattern was similar to massive hepatic necrosis, and there was extensive HSV replication in the liver lesions. In the liver, DNA fragmentation characteristic of apoptosis followed the time course of HSV-1 propagation. These findings suggest that one of the underlying conditions for fulminant viral hepatitis may be inadequate macrophage response, and that the massive hepatic damage, often defined as cell necrosis, may actually be apoptosis of liver cells subsequent to virus infection.

Estrogen protects against while testosterone exacerbates vulnerability of the lateral striatal artery to chemical hypoxia by 3-nitropropionic acid

Gender differences in the vulnerability of the lateral striatal artery (1STR artery) to systemic intoxication with 3-nitropropionic acid (3-NPA, succinate dehydrogenase inhibitor) were studied. Subcutaneous injection of 3-NPA (20 mg/kg once a day for 2 days) induced striatal selective lesions in half of male rats associated with motor symptoms (rolling, paddling, recumbency, etc) while female rats were resistant. Lesions were located in the lateral striata and characterized by astroglial necrotic cell death, enhanced immunoreaction to factor VIII-related antigen, edema, extravasation of IgG and sometimes bleeding. The motor and histological disturbances were highly sex-dependent and modulated by changes in hormonal levels. Males were more susceptible than females. Castration had little effect but ovariectomy enhanced the vulnerability. Replacement therapy with testosterone increased while estradiol or tamoxifen suppressed the vulnerability in ovariectomized females. Investigation of the arterial architecture of the brain often revealed rectangular and acute angled branchings in the centrolateral striatum where the ISTR artery feeds. A parallel in vitro toxicity study demonstrated that an extreme Ca++ overload and a strong cellular swelling resulted in astrocytic cell death. Data suggest that 1STR artery and astrocytes are highly vulnerable to 3-NPA intoxication in males. The greater vulnerability of the ISTR artery may contribute to the pathogenesis of neurodegenerative diseases, striatal bleeding, etc. Protective effects of estrogen and tamoxifen may mediate gender differences often observed in these disorders and suggest their potential use as therapeutic agents for these disorders.

A neuronal C5a receptor and an associated apoptotic signal transduction pathway

1. We report the first experimental evidence of a neuronal C5a receptor (nC5aR) in human cells of neuronal origin. Expression of nC5aR mRNA was demonstrated by the reverse transcriptase-polymerase chain reaction (RT-PCR) in TGW human neuroblastoma cells. 2. Expression of a functional C5aR was supported by the finding that C5a evoked a transient increase in the intracellular calcium level as measured by flow cytometry (FACS). 3. To analyse the function of the nC5aR, an antisense peptide fragment of the C5aR was used. Previous data showed that a C5aR fragment (a peptide termed PR226) has C5aR agonist and antagonist effects in U-937 cells depending on the concentration of the peptide. We found that a multiple antigenic peptide (MAP) form of the same peptide (termed PR226-MAP) induced rapid elevation of nuclear c-fos immunoreactivity and resulted in DNA fragmentation, a characteristic sign of apoptosis, in TGW cells. 4. Early electrophysiological events characteristic of apoptosis were also detected: intermittent calcium current pulses were recorded within 1-2 min of peptide administration. C5a pretreatment delayed the onset of this calcium influx. 5. We also demonstrated that the apoptotic pathway is linked to nC5aR via pertussis toxin-sensitive G-proteins. 6. Although the function of C5a and its receptor on neurons is unknown, these results suggest that an abnormal activation of this signal transduction pathway can result in apoptosis and, subsequently, in neurodegeneration.

An inhibitor of aldose reductase and sorbitol accumulation from Anthocepharus chinensis

A flavonoid glycoside was isolated from Anthocepharus chinensis. Its structure was elucidated by spectral data and determined to be myricetin 3-O-(4"-acetyl)-alpha-fucoside. This flavonoid glycoside and its aglycone showed potent inhibition against rat and porcine lens aldose reductase. The flavonoid aglycone also inhibited sorbitol accumulation in human red blood cells.

Changes in intracellular Ca2+ induced by GABAA receptor activation and reduction in Cl- gradient in neonatal rat neocortex

We have studied the effects of gamma-aminobutyric acid (GABA) and of reducing the Cl- gradient on the [Ca2+]i in pyramidal neurons of rat somatosensory cortex. The Cl- gradient was reduced either with furosemide or by oxygen-glucose deprivation. Immature slices taken at postnatal day (P)7-14 were labeled with fura-2, and [Ca2+]i was monitored in identified pyramidal cells in layer II/III as the ratio of fluorescence intensities (RF340/F380). The magnitude of the [Ca2+]i increases induced by oxygen-glucose deprivation was significantly reduced (by 44%) by bicuculline (10 microM), a GABAA receptor antagonist. Under normal conditions, GABA generally did not raise [Ca2+]i, although in some neurons a small and transient [Ca2+]i increase was observed. These transient [Ca2+]i increases were blocked by Ni2+ (1 mM), a blocker of voltage-dependent Ca2+ channels (VDCCs). Continuous perfusion with GABA did not cause a sustained elevation of [Ca2+]i but bicuculline caused [Ca2+]i oscillations. After inhibition of Cl- extrusion with furosemide (1.5 mM), GABA induced a large [Ca2+]i increase consisting of an initial peak followed by a sustained phase. Both the initial and the sustained phases were eliminated by bicuculline (10 microM). The initial but not the sustained phase was abolished by Ni2+. In the presence of Ni2+, the remaining sustained response was inhibited by the addition of 2-amino-5-phosphonopentanoic acid (AP5, 20 microM), a selective N-methyl-D-aspartate (NMDA) receptor antagonist. Thus the initial peak and the sustained phase of the GABA-evoked [Ca2+]i increase were mediated by Ca2+ influx through VDCCs and NMDA receptor channels, respectively, and both phases were initiated via the GABAA receptor. These results indicate that, in neocortical pyramidal neurons, a reduction in the Cl- gradient converts the GABAA receptor-mediated action from nothing or virtually nothing to a large and sustained accumulation of cellular Ca2+. This accumulation is the result of Ca2+ influx mainly through the NMDA receptor channel. Thus GABA, normally an inhibitory transmitter, may play an aggravating role in excitotoxicity if a shift in the Cl- equilibrium potential occurs, as reported previously, during cerebral ischemia.

NMDA receptor-mediated differential laminar susceptibility to the intracellular Ca2+ accumulation induced by oxygen-glucose deprivation in rat neocortical slices

Slices of somatosensory cortex taken from immature rats on postnatal day (P)7-14 were labeled with fura-2. Intracellular Ca2+ concentration ([Ca2+]i) was monitored in identified pyramidal cells as the ratio of fluorescence intensities (RF340/F380) during oxygen-glucose deprivation. The RF340/F380 ([Ca2+]i) of individual pyramidal cells was monitored in each of the cortical layers II-VI simultaneously. Neurons in all neocortical layers exhibited significant increases in [Ca2+]i that varied with the duration of oxygen-glucose deprivation. Individual neurons responded to oxygen-glucose deprivation with abrupt increases in [Ca2+]i after various latencies. The ceiling level of the [Ca2+]i increase differed from cell to cell. Neurons in layer II/III showed significantly greater increases in [Ca2+]i than those in layers IV, V, or VI. Kynurenic acid, a nonselective glutamate receptor antagonist, and bicuculline, a selective gamma-aminobutyric acid (GABA)A receptor antagonist, suppressed the intracellular Ca2+ accumulation induced by oxygen-glucose deprivation in all neocortical layers examined. After kynurenic acid, but not after bicuculline, there was no longer a differential [Ca2+]i increases in layer II/III. Both 2-amino-5-phosphonopentanoic acid (AP5), a selective N-methyl-D-aspartate (NMDA) receptor antagonist, and 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), a non-NMDA receptor antagonist, strongly suppressed the intracellular Ca2+ accumulation induced by oxygen-glucose deprivation in all layers. The laminar difference in terms of the [Ca2+]i increases was abolished by AP5, but not by CNQX. These results indicate that layer II/III cells are the most prone to oxygen-glucose deprivation-induced intracellular Ca2+ accumulation, and that this is primarily mediated by NMDA receptors. Thus, layer II/III neurons would be more likely to suffer cellular Ca2+ overload and excitotoxicity during ischemia than layer IV-VI cells. Such a differential laminar vulnerability might play an important role in determining the pathological characteristics of the immature cortex and its sequelae later in life.

Vulnerability to cerebral hypoxic-ischemic insult in neonatal but not in adult rats is in parallel with disruption of the blood-brain barrier

BACKGROUND AND PURPOSE

Vulnerability to cerebral hypoxic-ischemic (H-I) insult and its relation to disruption of the blood-brain barrier were investigated in postnatal rats.

METHODS

Pups of postnatal day (P) 7, P14, and P21 underwent ligation of a unilateral carotid artery and were exposed to hypoxic conditions. For the detection of early-phase deterioration, brains were perfusion-fixed 24 hours after H-I insult and examined by argyrophil III method. For the detection of later infarction, animals were fixed at 72 hours after the H-I insult.

RESULTS

In either case, tissue damage was detected in the striatum, parietal cortex, and hippocampus. The vulnerability of P7 and P21 rats was remarkable, as compared with P14 rats. Although the developmental status of the vasculature was not significantly different at each age, the permeability of IgG after H-I injury was prominent in P7 rats and to a lesser extent in P14 rats. In P21 rats, however, there was little IgG leakage even 24 hours after the insult. Dexamethasone pretreatment blocked the extravasation of IgG and reduced the damaged tissue in P7 and P14 rats but not in P21 rats. Percentages of reduction in infarcted areas by the dexamethasone became smaller in proportion to ages.

CONCLUSIONS

The results suggest that in younger rats vulnerability to H-I insult was in parallel with permeability of the blood-brain barrier, whereas in adults in might be more dependent on cellular vulnerability.

Cellular response to the redox active lipid peroxidation products: induction of glutathione S-transferase P by 4-hydroxy-2-nonenal

Membrane lipid peroxidation is known to produce various aldehydic compounds which cause a wide range of biological effects including heart disease, aging, and cancer. To investigate the effect of lipid peroxidation products on the expression of glutathione S-transferases (GSTs), which catalyze the conjugation of reactive chemicals with glutathione and play an important role in protecting cells, normal rat liver epithelial cells (RL34) were exposed to a variety of aldehydic compounds. We found that the GST activity in RL34 cells was induced by alpha,beta-unsaturated aldehydes, such as acrolein (1.3-fold), crotonaldehyde (1.3-fold), 4-hydroxy-2-hexenal (HHE) (1.4-fold), and 4-hydroxy-2-nonenal (HNE) (1.7-fold). The induction of GST activity by HNE was time-dependent, reaching a plateau after 16 h. The immunoblot analysis using the polyclonal antibodies against GST isozymes demonstrated that GST-P (pi-class), a well-known tumor marker, was significantly induced 16 h after the HNE treatment. Also, immunostaining for the presence of GST-P confirmed the enhanced expression of GST-P in the cytoplasm of the cells. Northern blot analysis revealed that the HNE treatment of RL34 cells for 1 h enhanced the expression of GST-P mRNA, which returned to the control level after 16 h. These data suggest that the induction of GST-P by HNE may represent an important cellular defense mechanism against oxidative injury.

Virus elimination and histologic improvement in patients with chronic hepatitis C treated with interferon alpha

We evaluated the elimination of hepatitis C virus (HCV) by means of interferon alpha (IFN-alpha) by investigating both positive- and negative-stranded RNA forms in the peripheral blood mononuclear cells and liver tissue. We also assessed the long-term histologic improvement accompanying viral clearance. We studied 20 persons with HCV whose serum aminotransferase levels remained normal for more than 1.5 years after IFN-alpha treatment withdrawal. The presence of HCV RNA in their peripheral blood and of both positive and negative strands in the peripheral blood mononuclear cells and liver tissue was investigated using the reverse transcription polymerase chain reaction method. We examined the histologic findings using the European classification and the histology activity index scoring system. In 16 of 20 patients, both strands disappeared from the possible reservoirs. The histologic findings indicated reduced activity, and histology activity index scores (1, 2, 3, and total) also showed significant improvement. We confirmed that IFN-alpha therapy can induce the elimination of HCV RNA from the conceivable HCV reservoirs and effect histologic improvement. Therapy with IFN-alpha is effective for treating chronic hepatitis C.

Dopamine-denervation enhances the trophic activity in striatum: evaluation by morphological and electrophysiological development in PC12D cells

To evaluate the possibility that dopamine (DA) denervation enhances the trophic activity in striatum, normal or DA-depleted striatal tissue extract (N- or L-extract, respectively) was obtained, and their trophic effects on PC12D cells were investigated from the viewpoints of differentiation using morphological and electrophysiological analyses. Treatment with N- or L-extract induced neurite outgrowth in a concentration-dependent manner, and induced the enlargement of cell size. These effects were stronger in L-extract than in N-extract. Cation currents were investigated in whole cell patch-clamp mode. Development of cation current started with delayed-rectifier type K+ current (IK) and transient type K+ current (IA), followed by Ca2+ current (ICa) and tetrodotoxin-sensitive Na+ current (INa). INa was expressed more frequently in L-extract treated cells than N-extract treated cells at D7-9. The larger IK amplitude in L-extract treatment at D7-9 seemed to be related to the expression of INa. Development of IA was similar at any stage for both treatments. ICa development started at D3-5 after treatments, and the amplitude and current density were similar in both treatments. ICa was strongly blocked by omega-conotoxin GVIA (3 microM), indicating that N-type channels were mainly expressed after treatments. The data suggests that L-extract has stronger effects to hasten the differentiation of PC12D cells than N-extract by promoting the neurite outgrowth, cell enlargement and expression of voltage-dependent cation channels, especially INa and IK.

[Diagnosis of tumor extension of ductal adenocarcinoma of the pancreas based on histological findings]

This study was undertaken to evaluate the diagnosis for tumor extension of ductal adenocarcinoma of the head of the pancreas based on histological investigation. From 1968 to 1995, 316 patients underwent radical resection and histological tumor extension was quite as follows; the rate of invasion to the anterior pancreatic capsule was 49%, invasion to the retroperitoneal tissue was 77%, invasion to the portal vein system was 38%, invasion to the extrapancreatic nerve plexus was 53% and lymph node metastases were 79%. 249 patients was performed extended radical operation consisted of regional lymphadenectomy, retroperitoneal dissection and resection of portal vein system, however non-curative resection was 52% with tumor invasion to dissected pancreatic surface in 88% of non-curative patients. And there was no 5-year survivor with non-curative resection. The extended radical operation should be indicated for patients who will have curative resection. Then, we set up clinical stage (CS; CSI approximately IV) by three factors related to resectability mostly; invasion to retroperitoneal tissue (RP), invasion to portal vein system (PV), invasion to major arterial system (A). It was also set up preoperative diagnostic criteria for RP, PV and A factor by computed tomography (CT) or abdominal angiography. From 1989 to 1995, 101 patients who had extended radical operation were investigated prospectively. The rate of accuracy of preoperative diagnosis of tumor extension were about 80% in each factor. Curability was 94% in CS I, 67% in CS II, 43% in CS III, respectively, and 3-year survival rate was 53% in CS I, 35% in CS II, 2-year survival rate was 8% in CS III. However, in CS IV the rate of non-curative resection was 77% and there was no 2-year survivor. It was concluded that extended radical operation of ductal adenocarcinoma of the head of the pancreas should be indicated for patients in less than CS III diagnosed by CT or angiography preoperatively.

3-Nitropropionic acid increases the intracellular Ca2+ in cultured astrocytes by reverse operation of the Na+-Ca2+ exchanger

The effect of 3-nitropropionic acid (3-NPA) on intracellular calcium ([Ca2+]i) in cultured cortical and striatal astrocytes was examined using a calcium imaging technique with fura-2. 3-NPA (1.7 mM) increased the [Ca2+]i in cortical and striatal astrocytes. The latency for the onset of the rise in [Ca2+]i in cortical astrocytes was 22.7 +/- 0.8 min and was significantly longer in striatal astrocytes (39.2 +/- 2.4 min; P < 0.001). The maximal increase in [Ca2+]i for both astrocytes was seen after 50 min and remained at that level even after extensive washing. The maximal responses were about 125 and 140% of the initial values for striatal and cortical cells, respectively. Pretreatment (2-3 h) with creatine (25 mM) significantly delayed the onset of increase in [Ca2+]i by 3-NPA in cortical (39.8 +/- 3.7 min) and in striatal (57.8 +/- 2.5 min) astrocytes from the respective untreated cells (P < 0.05). However, the [Ca2+]i increase was similar to that of the untreated cells at 60 or 90 min. The increase in [Ca2+]i by 3-NPA was not observed in Ca2+-free or low-Na+ medium, but there was rather a 10-15% decrease under the Ca2+-free condition (P < 0.05). Superfusion of normal Ca2+ (2 mM) medium after exposure of the cells to 3-NPA in Ca2+-free medium increased the [Ca2+]i dramatically and reversibly. This increase was significantly attenuated in the presence of 2',4'-dichlorobenzamil (100 microM), nifedipine (10 microM), or Ni2+ (2 mM) or after exposure to amiloride (1 mM). The blockade was total in the case of 2',4'-dichlorobenzamil. The results indicate that the 3-NPA-induced increase in [Ca2+]i in astrocytes was due to an influx of Ca2+ by the reverse operation of the Na+-Ca2+ exchanger system, which may be responsible for the gliotoxic action of 3-NPA.

Inhibition of aldose reductase and sorbitol accumulation by astilbin and taxifolin dihydroflavonols in Engelhardtia chrysolepis

Dihydroflavonol taxifolin and its glycoside, astilbin, from Engelhardtia chrysolepis inhibited rat lens and recombinant human aldose reductase. Taxifolin also inhibited sorbitol accumulation in human red blood cells. Furthermore, this dihydroflavonol aglycone maintained the clarity of rat lens incubated with a high concentration of glucose. These dihydroflavonols may be effective for preventing osmotic stress in hyperglycemia.

Acute 3-nitropropionic acid intoxication induces striatal astrocytic cell death and dysfunction of the blood-brain barrier: involvement of dopamine toxicity

Mechanisms underlying the selective vulnerability of the lateral striatal area to the toxic effects of 3-nitropropionic acid (3-NPA) were investigated in rats. A single exposure to 3-NPA (20 mg/kg, s.c.) induced no deficits in behavior and histology, but subsequent injection produced motor symptoms, catalepsy, lip smacking, abnormal gait, paddling, rolling, opisthotonos, tremor, recombence, somnolence and so on, in 30% of the animals within a few hours. Diffusion-weighted magnetic resonance imaging of the brains revealed an area of high signal intensity in the bilateral striata. By this stage (within a few hours), striatal astrocytes had become swollen and disintegrated. Extravasation of immunoglobulin G was detected, indicating blood-brain barrier (BBB) dysfunction. Electron microscopy revealed edema and disorganization of structures inside the astrocytic end-feet around the branches of the lateral striatal artery. Neurons were less vulnerable than astrocytes to the 3-NPA injury. Treatment of the rats with D2 receptor agonist prior to exposure to 3-NPA attenuated the behavioral abnormalities and histological damage whereas pretreatment with D2 antagonist exacerbated these changes. The concentrations of extracellular dopamine (DA) and dihydroxyphenyl acetic acid (DOPAC) were both increased in rats exposed to 3-NPA. In vitro imaging of astrocytes revealed a progressive increase in [Ca2+]i after superfusion with 3-NPA, and the 'ceiling' level was maintained even after extensive washing. DA superfusion also increased the astrocytic [Ca2+]i and this increase was reversible. Data indicate that 3-NPA-induced striatal damage was associated with astrocytic cell death and dysfunction of the BBB. Intracellular edema and extreme Ca2+ overload induced by the toxin were further aggravated by an increase in the level of DA activity. These factors acting either singly or in combination may trigger astrocyte destruction.

Topography of hypoxic injury proved by argyrophilia in postnatal rat brain

The argyrophil III method, a new esterification-silver staining approach, was used to elucidate regional differences in the susceptibility of developing brain to hypoxic-ischemic (H-I) injury. We created a unilateral common carotid artery-ligation model with hypoxia (8% oxygen) in postnatal day (P) 7, P14 and P21 rats. The argyrophil (i.e., deteriorated) neurons were apparent in the ipsilateral hippocampus, cortex, and striatum in each age group. Argyrophil neurons exhibited some morphological signs of the "early phase" of injury preceding the loss of structure and/or cell death in the "late phase," as indicated by hematoxylin-eosin (H-E) staining. The argyrophil neurons were apparent as early as 12 hours after the insult, whereas the histological changes revealed by H-E staining were subtle. The early phase and late phase histological changes had a stereotyped pattern of appearance in all ages studied. However, the duration of H-I situation required to produce argyrophil cells differed according to age. The most resistive age was P14 (P14 > P7 > P21) in this observation. Therefore, argyrophil III staining is feasible for H-I brain damage model in neonates. The results suggest that both the early phase and the late phase pathological processes after H-I injury have a characteristic topographical vulnerability that does not change during development but have a differing susceptibility according to age.

Antiperoxidative activity of neolignans from Magnolia obovata

Honokiol and magnolol, neolignans in Magnolia obovata, have been evaluated as antioxidants. Microsomal lipid peroxidation induced by Fe(III)-ADP/NADPH and mitochondrial lipid peroxidation induced by Fe(III)-ADP/NADH were inhibited by these compounds. These neolignans protected mitochondrial respiratory chain enzyme activity against NADPH-induced peroxidative stress and protected red cells against oxidative haemolysis. The anti-oxidative activity of honokiol was more potent than that of magnolol. Neolignans in M. obovata were shown to be effective in protecting biological systems and functions against oxidative stress.

4-Hydroxy-2-nonenal cytotoxicity in renal proximal tubular cells: protein modification and redox alteration

4-Hydroxy-2-nonenal (HNE), one of the major products of membrane lipid peroxidation, has been shown recently to be present in a form covalently attached to proteins in the renal proximal tubules of rats treated with a renal carcinogen, ferric nitrilotriacetate (Toyokuni, S., et al. (1994) Proc. Natl. Acad. Sci. USA 91, 2616-2620; Uchida, K., et al. (1995) Arch. Biochem. Biophys. 317, 405-411). In the present study, the mechanism of HNE cytotoxicity was studied using the renal tubular epithelial cells (LLC-PK1), focusing on the protein modification and alteration of cellular redox status induced by HNE. Upon treatment with HNE for 2 h, the LLC-PK1 cells were found to be resistant to the low concentration (10 microM) of HNE, while HNE at higher concentrations (> or = 50 microM) mediated cell death. The cytotoxicity of HNE appeared to be correlated with the HNE modification of cellular proteins. Among a number of proteins modified by HNE, a glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase was detected as one of the major targets of HNE in the cells. On the other hand, exposure of LLC-PK1 cells to HNE resulted in rapid reduction of cellular glutathione (GSH) levels, suggesting that HNE influenced primarily the redox status of the cells. Depletion of GSH with buthionine sulfoximine, a potent suppressor of GSH biosynthesis, before HNE treatment caused the cells to be sensitive to HNE cytotoxicity and to HNE modification of cellular proteins, whereas the increase in intracellular GSH levels by treatment with N-acetylcysteine before HNE treatment resulted in a dose-dependent inhibition of HNE-mediated protein modification. These results suggest that intracellular GSH is a determinant on cellular resistance against the HNE-mediated cytotoxicity.

Parameters for plaque formation in the potency assay of Japanese measles vaccines

Parameters for plaque formation by measles vaccine strains licensed in Japan were studied. For the plaque test, inoculum volume was one of the critical factors for obtaining an appropriate titre of the sample. A linear relationship between the inoculum volume and the apparent reciprocal titre was discovered, enabling the comparison of absolute titres. Another factor affecting the infectivity was the strain-specific temperature sensitivity in the plaque assay. Although all the vaccine strains tested showed the highest titre at 35 degrees C, the pattern of the temperature sensitivity differed from one strain to another. These factors must be taken into consideration in order to obtain an appropriate titre of a vaccine virus.

Rheumatoid factor in the serum of hepatitis C virus-infected patients: an increase in the titre during cold storage

Storage of serum at 4 degrees C elevated the titre of rheumatoid factor (RF) as measured by nephelometry with IgG-coated latex in 12 of 38 specimens positive for hepatitis C virus. Increased RF following cold storage was not detected in HCV-negative sera. Most of the sera showing the cold-dependent elevation of RF had decreased complement hemolytic activity (CH50) after the cold storage. The RF titre elevated by cold storage decreased to the level of fresh serum by the addition of guinea pig serum as a complement supplement in a dose-dependent fashion. Thus, in the serum of some HCV-infected patients, the affinity of RF appears to be weak, and the binding between the RF and IgG coated on latex may be inhibited by the complement components of fresh serum.

[Surgical treatment of aorto-iliac occlusive disease]

Recently, various endovascular techniques were applied to the short segmental stenosis of aorto-iliac artery. However, bypass operation is the most reliable treatment for multiple stenotic or occlusive lesion. Preoperative systemic evaluation is important for the adequate selection of the patients and the operations. Dipyridamole-thallium scintigraphy is more useful than exercise stress testing to assess cardiac risks of patients with peripheral arterial diseases. Anatomical bypass is the standard operation resulting in favorable patency. Despite of relatively inferior long term patency, extra-anatomical bypass operations are useful alternatives for the patients having high systemic risks or severe sclerosis of aorto-iliac arteries. The improved medical care of the elderly patients with severe systemic diseases results in the increase of extra-anatomical bypass and extended operation combined with infrainguinal revascularization.

3-Nitropropionic acid produces striatum selective lesions accompanied by iNOS expression

Systemically administered 3-nitropropionic acid (3-NPA) that inhibits the mitochondrial oxidative phosphorylation induces selective lesions in the striatum. To investigate the nature of these selective lesions, we administered 3-NPA (20 mg/kg, s.c. daily for 2 or 3 days) to Wistar rats and investigated the behavioral disturbance, striatal lesions and their variations after modulating the activity of nitric oxide synthase (NOS). On the second or third day of 3-NPA administration, half the animals manifested behavioral disturbances (paddling, rolling, tremor, abnormal gait, and recumbence). A strong extravasation of immunoglobulin G (IgG) and a decrease in immunoreaction for glial fibrillary acidic protein (GFAP) were detected, and iNOS-like (iNOS-L) immunoreactive small cells appeared in the lateral and central striatum especially around the vessels. A week later, lesions lacking GFAP-immunoreaction were detected in the striatum in survived animals. Pretreatment with N-nitro-L-arginine methyl ester (L-NAME) along with each injection of 3-NPA did not improve the behavioral disturbances nor the survival rate, but attenuated the extravasation of IgG and iNOS-L immunoreaction. Pretreatment with aminoguanidine or FK506 improved the behavioral symptoms and survival rate. Extravasation of IgG and expression of iNOS-L immunoreactivity were attenuated, and the striatal lesion was reduced. Data indicate the involvement of NO in the high vulnerability of the striatum, and that iNOS, one of inflammatory markers, is induced following exposure to 3-NPA.

Oxidative stress response in iron-induced renal carcinogenesis: acute nephrotoxicity mediates the enhanced expression of glutathione S-transferase Yp isozyme

An iron chelate, ferric nitrilotriacetate (Fe-NTA), induces acute renal proximal tubular necrosis, a consequence of free radical-mediated oxidative tissue damage, that eventually leads to a high incidence of renal adenocarcinoma in rodents. In the present study, we investigated the free radical-induced oxidative stress response in this carcinogenesis model, focusing on the expression of glutathione S-transferases (GSTs) which catalyze the conjugation of reactive chemicals with glutathione and play an important role in protecting cells. A single intraperitoneal Fe-NTA treatment (15 mg Fe/kg body weight) induced a rapid oxidative stress, which was monitored by the accumulation of lipid peroxidation products and the loss of sulfhydryl contents in the kidneys, resulting in a 30% reduction of GST activity 1 h after an Fe-NTA treatment. The enzyme activity returned to the control level after 16 h. The immunoblot analysis of GST isozymes demonstrated that the level of alpha-class GSTs (GST-Ya and GST-Yc) and pi-class GST (GST-Yp), major GST isozymes constitutively produced in the kidney, decreased immediately within 1 h of the Fe-NTA treatment. The onset of the recovery of GST-Yp protein levels was detected 3 h after the Fe-NTA treatment. The enhanced production of GST-Yp in gene expression was evident in the drastic elevation of mRNA levels and these increases coincided with a substantial rise in the GST activity and protein levels. The alpha-class GSTs were not inducible by treatment with Fe-NTA. The immunohistochemical analysis demonstrated that the expression of GST-Yp was strongly induced in the regenerating proximal tubular cells. A steady accumulation of GST-Yp protein was observed in the subacute toxicity experiments with multiple injections of Fe-NTA. These results suggest that the enhanced expression of GST-Yp is important in mediating cell repairs or increasing the resistance to subsequent injury.

Effect of Polygonum hydropiper sulfated flavonoids on lens aldose reductase and related enzymes

The sulfated flavonoids in Polygonum hydropiper showed potent inhibiton against lens aldose reductase. Among these flavonoids isorhamnetin 3,7-disulfate (5) was most potent. Kinetic analysis showed that 5 exhibited noncompetitive inhibition against both dl-glyceraldehyde and NADPH.

Tissue extract from dopamine-depleted striatum enhances differentiation of cultured striatal type-1 astrocytes

The effects of tissue extract from dopamine (DA)-depleted striatum (lesion extract, L-ext) on morphological and electrophysiological natures of cultured striatal astrocytes were investigated. L-ext treatment suppressed the proliferation of type-1 astrocytes. They became fibrous in a concentration-dependent manner. These changes were not observed in type-2 astrocytes. By whole cell patch-clamp recording, two kinetically and pharmacologically distinct voltage-activated potassium currents, A current and delayed rectifier, were identified. L-ext treatment enhanced both currents in type-1 astrocytes, but only A current in type-2. Data suggest that in tissue extract from DA-depleted striatum, there are increased trophic activities that promote the differentiation of type-1 astrocytes.

Second primary neoplasms in thyroid cancer patients

To determine risk patterns for second primary neoplasms after the occurrence of thyroid cancer, we conducted a retrospective cohort study of 3321 thyroid cancer patients who were operated and histologically confirmed at the Noguchi Thyroid Clinic and Hospital Foundation between 1946 and 1985. They were followed from the date of operation through the end of 1990 with an observation period from 45 to 5 years. The average observation period of the patients was 13.4 years and the follow-up rate reached 98%. The standardized mortality ratio (SMR) was computed to assess possible risk increase by cancer site. In this computation, the time period less than 5 years after operation was omitted to reduce the influence of deaths related to the original thyroid cancer. A total of 103 deaths from malignant neoplasms other than thyroid cancer were observed during this time period (SMR = 1.6, 95% confidence interval [CI] = 1.3-2.0). Analyses of site-specific cancer mortality revealed significantly elevated risks for the central nervous system (SMR = 16.1, CI = 5.2-37.6) and respiratory organs (SMR = 2.6, CI = 1.5-4.1). Based on a review of available medical records with histological findings, we concluded that the risk increases for these sites were most likely to be attributable to second primary neoplasms. Whether or not the patients had received radiotherapy was not significantly associated with elevated risk. Further investigations are needed to clarify the risk factors responsible for the above findings.

Quantification of leucocyte elastase and cathepsin G in plasma by a simple method: effect of elastase in plasma levels of D-dimer and thrombomodulin

The purpose of this study was to determine levels of leucocyte elastase and cathepsin G in the plasma of patients in various pathological states, in which plasma increases or decreases in coagulation and fibrinolytic factors were seen. Simple methods were developed to measure the leucocyte proteinases and the results were correlated with conventional assays of coagulation and fibrinolytic factors. The total number of patients and total number of plasma samples examined were 340 and 1292, respectively. No correlation was observed between the plasma levels of elastase and cathepsin G, and plasminogen, fibrinogen and leucocyte counts. There was a weak overall correlation, however, between the leucocyte proteinases and each of the four parameters: D-dimer, thrombomodulin, antithrombin III and platelet count. There was a strong correlation between leucocyte proteinases and D-dimer and thrombomodulin in those patients with plasminogen levels within the normal range. Increased D-dimer levels, as well as plasmin, may suggest that elevated leucocyte proteinases contribute to elevated fibrinolytic mechanisms in these instances.