Schistosoma mansoni: fatty acid-induced cercarial tail loss does not involve eicosanoid production and chemoreceptors

Inhibitors of eicosanoid production had no effect on linoleic acid-induced Schistosoma mansoni cercarial tail loss. In addition, linoleic acid-induced cercarial tail loss was not inhibited by silver nitrate, which binds to putative chemoreceptors for fatty acids in cercariae. There was no correlation between molecular structures of fatty acids and their potencies to induce tail loss. Furthermore, transcompounds of fatty acids which cannot be precursors of eicosanoids elicited tail loss as potently as cis-compounds did. The present results suggest that fatty acid-induced cercarial tail loss is not mediated by eicosanoid production and chemoreceptors, which are involved in cercarial penetration behavior stimulated by fatty acids.

Amino acid sequence of glutathione S-transferase a from guinea pig liver

The amino acid sequence of glutathione S-transferase a from guinea pig liver was determined. Glutathione S-transferase a was composed of two identical subunits, each comprising 218 amino acid residues. The amino acid sequence of glutathione S-transferase a exhibited 73% homology with that of human glutathione S-transferase Ha, 69% with that of rat glutathione S-transferase Ya, and 68% with that of rat glutathione S-transferase Yc, which are known to belong to class Alpha. From the above result, together with previous observations on its substrate specificity, it was concluded that glutathione S-transferase a belonged to class Alpha.

Enhanced inhibitory effect of polymeric star burst formed yigsr Peptide on newly established nude-mouse spontaneous adenocarcinoma metastatic model

A highly metastatic nude mouse adenocarcinoma cell line, XK-4, was established, and the inhibitory effect of the polymeric star burst YIGSR peptide on XK-4 metastasis was examined. XK-4 adenocarcinoma arose spontaneously in a nude mouse after the subucutaneous transplantation of a human colon cancer. XK-4 cells were first cultured in February, 1990 after serial transplantation of the tumor in nude mice since October, 1985. The XK-4 cell line produces blood borne lung or liver metastasis 2 weeks after injection into the tail vein or anterior mesenteric vein, respectively. Chromosomal analysis of the XK-4 cell line revealed only murine chromosomes, and isozyme analysis showed a murine pattern. Transplantation of XK-4 cells into a thymus-intact litter mate was rejected. These results suggest that the XK-4 adenocarcinoma grew spontaneously in the nude mouse due to some kind of human cancer stimulation. A peptide consisting of the active domain of laminin, YIGSR, was chemically synthesized as a polymer with a star burst pattern. The inhibitory effect of polymeric star burst YIGSR on XK-4 metastasis was enhanced, compared with monomeric YIGSR. These effects appear to be due to the prolonged half-life of polymeric star burst YIGSR in vivo, and increased binding of polymeric star burst YIGSR to the YIGSR receptor. In this study we established a new metastatic model, and confirmed the enhanced metastatic inhibitory effect of a polymeric form of the star burst YIGSR peptide.

Induction of cytochrome P450 1A2 by musk analogues and other inducing agents in rat liver

We characterized the inducing effects of two musk analogues, musk xylene and musk ambrette, on phase I and phase II drug-metabolizing enzymes in rat liver and compared their effects with 3-methylcholanthrene, isosafrole and 2(3)-tertbutylhydroxyanisole (BHA) at 0.1 mmol/kg dose level. Musk xylene and isosafrole increased more efficiently the metabolic activation of 2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole (Glu-P-1) to mutagen than that of benzo(a)pyrene. Musk ambrette increased both the activation of Glu-P-1 and benzo(a)pyrene to the same extent. Western blot analyses revealed that musk xylene, musk ambrette, isosafrole and BHA induced more strongly cytochrome P450 1A2 (CYP1A2) in microsomes than CYP1A1. 3-Methylcholanthrene induced CYP1A1 in preference to CYP1A2. On the other hand, all drugs except for 3-methylcholanthrene did not show remarkable increases in phase II enzyme activities, such as DT-diaphorase, glutathione S-transferase and UDP-glucuronyltransferase, at 0.1 mmol/kg dose level. These results show that musk xylene, musk ambrette, isosafrole and BHA at the dose level used in this study possess the potency to induce CYP1A2 without remarkable induction of CYP1A1 and phase II enzyme activities as observed for 3-methylcholanthrene, although they have been considered to induce both phase I and phase II drug-metabolizing enzymes at higher doses.

Dynamics and participation of type II phospholipase A2 in rat zymosan-induced pleurisy

Intrapleural injection of zymosan into rats induces acute inflammation characterized by plasma leakage and cellular influx. The level of type II phospholipase A2 (PLA2) increased in the pleural fluid as well as in exudating leukocytes after the injection of zymosan. Rather low PLA2 activity was found in cell lysates, though treatment of such lysates at low pH increased the PLA2 activity drastically. The appearance of "acid-extracted" PLA2 activity in leukocytes preceded that of the extracellular enzyme activity, suggesting that pleural leukocytes might be one of the origins of the extracellular enzyme. Treatment of exudating pleural leukocytes with purified rat type II PLA2 elicited the production of prostaglandin E2, but not platelet-activating factor appreciably. These findings indicate that type II PLA2 might play a role in the progression of inflammation through the production of eicosanoids in the present inflammation model.

[Maintenance therapy on the anemia in continuous ambulatory peritoneal dialysis (CAPD) patients using subcutaneous administration of recombinant human erythropoietin fortnightly--a multicenter trial]

Eighty-seven CAPD patients whose hematocrit (Ht) level was maintained by recombinant human erythropoietin (rHuEPO) were enrolled in this trial for a new formulation of rHuEPO suitable for subcutaneous injection. 6000IU rHuEPO was administered every 2 weeks for 12 weeks. Fortnightly doses were increased to 9000IU or 12000IU at 4 or 6 weeks if the Ht level decreased by 2% or more. During the study period, Ht values were maintained at the appropriate level in 88% of patients. 6000IU or lower was selected as a maintenance dose given every 2 weeks in 57 (76.0%) patients, 9000IU was selected in 8 patients and 12000IU was chosen in one patient. In 9 patients, the Ht could not be maintained during the study and the appropriate dose, therefore, remained unclear. Hypertension was observed in 2 patients as a side effect, and headache occurred in 2 other patients during the trial. Cutaneous abnormalities were not observed in the course of the subcutaneous injections. We conclude that anemia in most CAPD patients could be controlled with fortnightly injections in the dose range of 6000 to 12000IU rHuEPO given subcutaneously.

[Establishment of a human lung squamous cell carcinoma cell line LK-17, and characterization of procoagulant, platelet aggregation and metastatic potential]

A squamous cell carcinoma cell line LK-17 was established from original surgical specimen of the lung. Doubling time of LK-17 in vitro is 43.2 hours, and chromosome analysis shows various abnormality and main modeat 62. LK-17 shows stable metastatic potential to the lung of nude mouse when injected i.v. LK-17 cells show platelet aggregating activity with number population dependent manner. LK-17 secretes direct factor X activating procoagulant which differs from those of tissue factor, cystein protease A and coagulant cancer antigen 1. These platelet aggregation potential and procoagulant activity may play a important roll in metastatic process.

Involvement of opioid receptors in shaking behaviour induced by paraquat in rats

Paraquat (30-70 mg/kg intraperitoneally) caused typical shaking behaviour in rats in a dose-dependent manner. Myoclonus also appeared after the shaking behaviour in several rats treated with the highest dose of paraquat. Morphine (5 mg/kg intraperitoneally, 30 min. before paraquat) significantly reduced the frequency of shaking behaviour. The alleviation by morphine disappeared when naloxone (1.5 mg/kg intraperitoneally 15 min. after morphine) was coadministered. Although there was no histological change in brain slices of paraquat-treated rats (70 mg/kg intraperitoneally), the fluorescein uptake into brain was increased by the treatment. Morphine prevented the increase of fluorescein uptake, but naloxone failed to antagonize this effect. On the other hand, intracerebroventricularly administered paraquat (25.7 micrograms/rat) caused tremor in all rats, but not shaking behaviour nor myoclonus. These findings suggest that paraquat administered systemically as well as centrally may be toxic to the brain. Although the actions of paraquat on the brain seem to be complicated, opioid receptors may play a role in the actions.

Role of calcium ion in Schistosoma mansoni cercarial tail loss induced by unsaturated fatty acids

Linoleate (C18: 2) and oleate (C18: 1), but not stearate (C18: 0), induced tail removal in cercariae. Linoleate stimulated tail loss more strongly than oleate did. Tail loss induced by linoleate was significantly suppressed by incubating cercariae with ethyleneglycol-bis-(beta-aminoethyl ether) N,N,N',N'-tetraacetic acid (EGTA). Preincubation of cercariae with EGTA for 5 min caused further inhibition of the tail loss. Calcium ionophore A23187 (A23187) increased the cercarial tail-loss rate. When A23187 was combined with linoleate at 0.03 mM, an additive effect on tail loss appeared, whereas the ionophore in combination with linoleate at 0.3 mM had no such effect. EGTA almost completely abolished cercarial tail loss induced by linoleate at both 0.03 and 0.3 mM in the presence and absence of A23187. Linoleate at 3 mM provoked cercarial tail loss even in the presence of EGTA, although the effect of oleate at 3 mM disappeared. Under these conditions, the effect of linoleate was synergistically enhanced by the combination with A23187. A similar, but not significant, synergism took place in cercariae stimulated by oleate. These findings suggest that unsaturated fatty acids enhance calcium influx into cercariae, resulting in triggering tail loss, and, furthermore, that the fatty acids have other potentiating effects on cercarial tail loss. Protein kinases play an insignificant role in fatty acid-induced cercarial tail loss, because a protein kinase C inhibitor, 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine (H-7), and an inhibitor of various protein kinases, staurosporine, had little or no effect on cercarial tail loss induced by linoleate at 3 mM.

Studies of cardiovascular responses to some endogenous pressor and hypotensive agents in conscious stroke-prone spontaneously hypertensive rats of different ages

The effects of the endogenous pressor agents noradrenaline (NA), and angiotensin II (Ang II), and of the hypotensive agents acetylcholine (ACh) and adenosine (ADS), on blood pressure and heart rate in conscious and unrestrained stroke-prone spontaneously hypertensive rats (SHR-SP) and normotensive Wistar Kyoto rats (WKY) of different ages (4-9 weeks old) were investigated. Pressor responses to NA were enhanced in 7- and 9- week-old SHR-SP compared with those in WKY, but pressor responses to Ang II in SHR-SP were not different from those in WKY at all ages. The bradycardias following pressor responses to NA and Ang II were markedly attenuated in SHR-SP, especially older ones. Hypotensive responses to ACH were enhanced in SHR-SP, particularly at 9 weeks of age. However, hypotensive responses to ADS were attenuated in SHR-SP, especially at 7 weeks of age. Transient fall of heart rate due to ADS was also attenuated in 7- and 9- week-old SHR-SP. These alterations of hemodynamic or cardiovascular responses in SHR-SP became more evident in the established stages of hypertension. These results suggest intimate relationships of the enhanced pressor responses to NA, attenuated bradycardias following pressor effects with NA or Ang II, and the attenuated hypotensive responses to ADS with the development or the maintenance of hypertension in SHR-SP.

Re-uptake of nascent low-density lipoproteins by HepG2 cells

The kinetics and specificity of the interaction of nascent HepG2 LDL with the HepG2 LDL receptor were examined. 125I-Labeled HepG2 LDL and plasma LDL were bound by HepG2 cells in a specific and saturable manner at 4 degrees C. Competition studies with HepG2 LDL and plasma LDL indicated that both ligands bound to the same receptor. Scatchard analyses of the specific 4 degrees C-binding data revealed a Kd of 75 nM for HepG2 LDL and a Kd of 30 nM for plasma LDL suggesting that HepG2 LDL bind less efficiently to the HepG2 LDL receptor than plasma LDL. Binding, internalization and degradation studies carried out at 37 degrees C indicated that HepG2 cells are capable of catabolizing their own nascent LDL; however, under normal experimental conditions re-uptake of nascent LDL is quantitatively insignificant.

Esophagectomy for metastatic carcinoma of the esophagus from lung cancer

A patient with metastatic carcinoma of the esophagus from lung cancer is reported. The patient was a 54-year-old woman who underwent a left lower lobectomy for lung cancer 5 years previously. The authors performed a thoracic esophagectomy, dissection of mediastinal lymph nodes, and reconstruction of the esophagus; the surgery was followed by chemotherapy. Because the histologic pattern of the esophageal tumor was similar to that of lung cancer and mucosal involvement was not seen, the esophageal tumor was interpreted to be a metastasis from lung cancer. The patient is well without recurrence of disease 23 months after operation. This is the first report of a successful esophagectomy for metastatic carcinoma of the esophagus from lung cancer.

Interindividual variability of carbonyl reductase levels in human livers

Interindividual variability of carbonyl reductase levels in human livers (N = 11) was examined by measuring reductase activity toward various substrates and by western blot analysis using anti-rat ovarian carbonyl reductase CR2 antibody. The carbonyl reductase activity toward p-nitrobenzaldehyde (PNBA) (58.1 +/- 5.4 nmol/mg protein/min, mean +/- SE) was highest among the substrates examined, followed by 4-benzoylpyridine (4BP) (14.4 +/- 2.0 nmol/mg protein/min) and p-nitroacetophenone (PNAP) (2.00 +/- 0.37 nmol/mg protein/min). The reductase activity (6.33 +/- 0.56 pmol/mg protein/min) toward 13,14-dihydro-15-keto-prostaglandin F2 alpha (15KD-PGF2 alpha), which is a diagnostic substrate for rat ovarian carbonyl reductases, was relatively high compared to that in other species. Western blot analysis revealed that each human liver contained several immunoreactive proteins to anti-CR2 antibody. The activities toward 15KD-PGF2 alpha (r = 0.85, P < 0.01) and 4BP (r = 0.84, P < 0.01), but not PNBA (r = 0.53, not significant) or PNAP (r = 0.52, not significant), were closely correlated with the relative amounts of the high molecular weight immunoreactive proteins determined with a densitometer. Thus, the major carbonyl reductases in human liver are similar to those of rat ovarian enzymes.

[Detection of chromosomal aberration using fluorescence in situ hybridization in DNA diploid colorectal carcinomas]

Numerical aberrations of chromosomes can be detected by fluorescence in situ hybridization (FISH), using chromosome-specific probes. It is possible to observe this in solid tumors from which it is very difficult to obtain metaphase nuclei. The present study employed surgical specimens from 15 cases of colorectal carcinoma, all of which showed DNA diploidy. In the same samples, we analyzed chromosomal numerical aberration by FISH according to the method of Pinkel et al. Biotinylated DNA probes specific to chromosome #7, #11 and #17, were used. The hybridization spots were observed by fluorescent microscopy. As a result, the numerical aberrations of chromosomes detected by FISH were found in DNA diploid cases by FCM. They were trisomy and monosomy. These results indicate that FISH is useful to detect the chromosomal aberrations of DNA diploid cases.

[Evaluation of chemosensitivity test for cancer using the collagen gel embedded culture system--DNA ploidy pattern and chemosensitivity]

The authors previously reported the advantages of a collagen gel embedded culture system for chemosensitivity tests for cancer. In this report, the chemosensitivities of surgically resected specimens were evaluated by the collagen gel embedded culture system and compared with the DNA ploidy pattern, measured by flow cytometry. The chemosensitivity and DNA ploidy pattern were determined in 11 patients with lung cancer, 8 with gastric cancer and 46 with colorectal cancer. Anticancer agents were MMC and CDDP at Cmax for one hour of exposure, and 5-FU, VDS, VP-16 and ADM at one tenth the Cmax for 24 hours of exposure. Results were compared with those of DNA histogram. In eight lung cancers which were demonstrated to be sensitive by the collagen gel system, 5 showed DNA aneuploidy (DA) and 3 DNA diploidy (DD). Seven cases (87.5%) of gastric cancer were demonstrated to be sensitive with the collagen gel system. Two of them showed DA and five DD. On the other hand, 19 cases (41.3%) of colorectal cancer were found to be sensitive, and 7 of them showed DA and twelve DD. Lung cancer and gastric cancer exhibiting aneuploidy demonstrated sensitivity with the collagen gel system, but the rate of sensitivity was only 28% in colorectal cancer, and even aneuploidy cases showed a low sensitivity.

[Ultrasonic findings of the cholecyst and biliary tract after gastrectomy]

Periodical ultrasonic findings were taken up to 1 year after operation in 207 gastric cancer patients and generation of gallstones after gastrectomy was examined. Abnormal ultrasonic findings were observed frequently in cases with advanced cancer and cases which received anticancer drugs, but operative procedures, reconstruction procedures and the degree of removal of lymph nodes did not significantly affect ultrasonic findings. Gallstone findings were observed from 3 months after operation. Among 18 of 135 cases (13.3%) with gallstone findings observed 12 months after operation, 10 had shifted from biliary debris and sludges to gallstones. In 53 cases which were able to be observed periodically from the preoperative period, 9 (17.0%) of gall stones were observed after 12 months, and 7 had shifted from biliary debris and sludges. In cases with abnormal ultrasonic findings, the serum GOT levels on day 1 and day 7, and GPT levels on day 1, day 7, and day 14 were significantly higher than the preoperative values. Hepatic dysfunction of the early postoperative stage and generation of biliary debris and sludges may play an important role in gallstone formation, and anticancer drugs after gastrectomy may have an aid of gallstone formation.

Hyperthyroidism with potent thyroid-stimulation-blocking antibodies and negative thyroid-stimulating antibodies after subtotal thyroidectomy for Graves' disease with follicular thyroid carcinoma

A 39-year-old woman with Graves' disease associated with follicular thyroid carcinoma underwent subtotal thyroidectomy. TSH-binding inhibitor immunoglobulins (TBII) were positive, whereas thyroid-stimulating antibodies (TSAb) and thyroid-stimulation-blocking antibodies (TSBAb) were both negative before the operation. After the operation, TBII markedly increased above the pretreatment value. TSBAb became positive 3 months after the operation and then their activity increased, while TSAb remained negative after the operation. Subtotal thyroidectomy may have influenced the development of TSBAb in this patient. Irrespective of these findings, the patient became hyperthyroid again several months after the operation.

[Comparison of typical and atypical bronchoplasty for bronchogenic carcinoma]

One-hundred and twenty-eight patients who underwent bronchoplasty for bronchogenic carcinoma from 1969 to 1990 were retrospectively analyzed. Ninety-six patients had upper sleeve lobectomy or upper lobectomy with wedge bronchoplasty (typical procedure) and 32 underwent bronchoplasty with lobectomy other than upper lobes (atypical bronchoplasty). The two groups were statistically similar in preoperative characteristics including sex, age, cell types and stages. In typical group, right upper sleeve lobectomy was performed in 48 patients, left upper sleeve lobectomy in 27, right upper lobectomy with wedge bronchoplasty in 11, left upper lobectomy with wedge bronchoplasty in 7 and sleeve bronchoplasty alone in 2. In atypical group, right middle and lower lobectomy with sleeve bronchoplasty in 10 patients, left lower sleeve lobectomy in 5, right lower lobectomy with wedge bronchoplasty in 4 and others in 13. Postoperative mortality was 5.2% in the typical group and 9.4% in the atypical group. Postoperative respiratory complications occurred in 16 patients (50%) in the patients with the atypical group and in 33 (34.7%) in those with typical group. Three years and 5 years survival rates in the typical group were 46 and 40% and those in the atypical group, 27 and 18%. However, there was no statistical difference in survival between the two groups. In conclusion, atypical bronchoplasty is useful for preserving the lung parenchyma, but, careful perioperative management and surgical technique of bronchoplasty are mandatory.

Product dependence of deuterium isotope effects in enzyme-catalyzed reactions

Theory for enzyme-catalyzed reactions is developed for the dependence on product concentration of deuterium isotope effects on V and V/K. Generally, a product that decreases the off-rate for a second product to zero causes the isotope effect on V/K to decrease to DKeq and that on V to decrease to a value between 1 and DKeq. If the second product off-rate is decreased to a finite value, DV and D(V/K) will decrease to a value greater than DKeq, while if there is no effect on the off-rate for the second product, DV and D(V/K) will not change. Interestingly, for a ping-pong mechanism, the presence of the product that provides a reversible connection between the isotope-sensitive step and the isotope-insensitive half-reaction will give an isotope effect on V/K for the latter. (In the absence of the product, the isotope effect on V/K for the isotope-insensitive half-reaction will be unity.) Theory is supported with data for alcohol and lactate dehydrogenases. For lactate dehydrogenase, D(V/Kpyruvate) decreases from 1.93 +/- 0.02 at zero to 1.16 +/- 0.02 at infinite lactate concentration, while DV decreases from a value of 1.75 +/- 0.03 at zero to a value of 0.93 +/- 0.05 at infinite lactate concentration. Thus, it appears that the pathway in which lactate is released first is greatly preferred, but the pathway in which NAD+ is released before lactate is observed at high lactate concentration.(ABSTRACT TRUNCATED AT 250 WORDS)

Mechanical modulation of a voltage-dependent non-inactivating K+ current in cultured bullfrog sympathetic neurones

Cultured bullfrog sympathetic ganglion cells were voltage-clamped with a whole-cell patch-clamp technique. Local flow of a solution (identical to the bathing solution) from a micropipette to a cell, but not other mechanical stimuli, produced a non-inactivating outward (in 34 cells out of 141) or inward (in 70 cells) current [I(f)(out) or I(f)(in), respectively] depending on cells. Both I(f)(out) and I(f)(in) appeared at voltages more positive than -60 mV. The mechanism, however, was activated even at -70 mV, as I(f)(out) or I(f)(in) appeared on shifting membrane potential to -30 mV immediately after the local flow. I(f)(out) and I(f)(in) were accompanied by increases and decreases, respectively, in the membrane conductance and current relaxation to a voltage jump between -30 mV and -55 mV without a change in its time constant (whose value was similar to that of a voltage-dependent non-inactivating K+ current, IM), and reversed at a membrane potential close to the equilibrium potential for K+. Both I(f)(out) and I(f)(in) were blocked by Ba2+ (4-8 mM), a blocker of IM, and by muscarine (10 microM), which produced either an "apparent inward" or outward current. A transient outward current activated by a voltage jump from -85 mV (or -75 mV) to -30 mV was little affected by a local flow of a solution which produced I(f)(out) or I(f)(in). These results suggest that the local solution flow produced I(f)(in) or I(f)(out) by deactivating or activating IM, respectively.

Transformation of HepG2 nascent lipoproteins by LCAT: modulation by HepG2 d > 1.235 g/ml fraction

We have previously shown that lecithin:cholesterol acyltransferase (LCAT) can transform ultracentrifugally isolated HepG2 lipoproteins (d < 1.235 g/ml) into particles that differ substantially from their nascent precursors. Transformed high density lipoprotein (HDL) subpopulations, as judged by nondenaturing gradient gel electrophoresis (GGE), resemble plasma HDL, i.e., HDL2a- and HDL3a-sized particles predominate. In HepG2 conditioned medium (CM), 60-70% of apoA-I is in the d > 1.235 g/ml fraction (lipid-poor apoA-I); hence we investigated whether inclusion of d > 1.235 g/ml fraction in LCAT incubations altered HDL subpopulations. After 18 h incubation of CM (containing lipoproteins and d > 1.235 g/ml fraction) with purified LCAT, the major transformation product on GGE was a large 9.7-nm particle (HDL2b pattern); a minor component appeared at 7.4 nm (HDL3c). Differences in particle size distribution between CM and isolated lipoprotein incubations were not the result of differences in LCAT activity; mass ratios of unesterified cholesterol:cholesteryl ester and phospholipid:cholesteryl ester were similar. Removal of apoA-I from the d > 1.235 g/ml fraction by immunoaffinity chromatography prior to incubation with the d < 1.235 g/ml fraction produced the same products (i.e., HDL2b pattern) as incubations performed with the unaltered d > 1.235 g/ml fraction; therefore, lipid-poor apoA-I does not influence nascent HDL transformation. Cholesteryl ester was transferred from HepG2 HDL to LDL in CM incubations; however, cholesteryl ester transfer protein was not immunochemically identified. Removal of HepG2 LDL from CM prior to incubation with LCAT still resulted in the HDL2b pattern. We conclude that HepG2 cells secrete a factor(s) that modifies nascent HDL transformation products into a predominantly HDL2b subpopulation.