[Surgical management for an unruptured cerebral aneurysm accompanied by anti-phospholipid antibody syndrome: a case report]

Anti-phospholipid antibody syndrome(APS) is characterized by the presence of antibodies to phospholipids and various symptoms including those derived from thrombosis. APS has been shown to be frequently accompanied by multiple and recurrent cerebral ischemic lesions, suggesting that APS may play a critical role in developing cerebral ischemia of unknown etiology. Here, we present a case with an unruptured cerebral aneurysm accompanied by a severe stenosis of the middle cerebral artery as a manifestation of APS. The aneurysm was successfully treated surgically employing the following precaution to prevent potential damage on the fragile ischemic brain: preoperative administration of anticonvulsant, intermittent brain retraction, intraoperative SEP monitoring, and postoperative administration of anticoagulant. Our experience suggests that unruptured cerebral aneurysms accompanied by APS could be safely treated by strict paraoperative management.

Continuous surveillance of organochlorine compounds in human breast milk from 1972 to 1998 in Osaka, Japan

The presence of chlorinated organic compounds in breast milk of lactating women living in Osaka Prefecture, Japan, has been followed since 1972. Following the highest concentration found at the start of the measurements, contamination by polychlorinated biphenyls (PCBs) and organochlorine pesticides, such as beta-HCH and DDT declined to about 3-13% of the peak levels by the mid-1970s and continued to decrease to low-level equilibrium states. This decline varies greatly with the chemical compound. In comparison with 1970s, when the contamination of breast milk was highest, the beta-HCH level fell to about 3%, DDT to about 7%, and PCBs to about 13%, representative of different half-lives in the environment and the particular persistence of PCB. In the case of chlordane, a termite insecticide, more than 10 years have passed since its use was prohibited in Japan, but it continues to be found in human breast milk, although at a low level.

Precancerous conditions for pancreatic cancer

Precancerous conditions for ductal adenocarcinoma of the pancreas in hamsters and human beings are discussed. In hamsters, ductal adenocarcinomas induced by nitrosamines are of nonmucin-hypersecreting tubular or papillary tumor types, and genetic alterations resembling these types are found in their human counterparts. Ductal lesions develop step-by-step from hyperplasias to carcinomas, and atypical ductal cell hyperplasias may be precancerous. In humans, ductal lesions, hyperplasias, or dysplasias, with or without mucin hypersecretion, are possible preneoplastic conditions. Genetic or phenotypic markers to determine their likelihood of progressing to pancreatic duct adenocarcinomas are a high priority for future research.

Dimethylarsinic acid induces 8-hydroxy-2'-deoxyguanosine formation in the kidney of NCI-Black-Reiter rats

Dirnethylarsenic peroxyl radical [(CH(3))(2)AsOO] has been postulated to be responsible for DNA damage induced by dimethylarsinic acid (DMA). In an effort to elucidate the possible mechanism of tumor-inducing potential of DMA, an experiment was designed to investigate the formation of 8-hydroxy-2'-deoxyguanosine (8-OHdG), a specific marker of oxidative base damage in the kidney tissues of NCI-Black Reiter (NBR) rats. Animals were divided into four groups and administered the vehicle - saline, 5, 10 and 20 mg/kg body weight respectively of DMA by gavage, once a day, 5 days a week, for a period of 4 weeks. DMA induced increase of 8-OHdG levels in the kidney of the rats treated, with the highest level at the dose of 10 mg/kg body weight. Analysis of the kidney for cell proliferation employing PCNA-positive index showed greater proliferation in the tissues of treated rats. However, DMA did not have any influence on apoptosis in this regimen. Histopathological examination of the kidney selections revealed the presence of vacuolated degeneration and dilation of the proximal tubule cells in two groups (10 and 20 mg/kg body weight). This study provides evidence to substantiate the role of DMA in inducing oxidative DNA damage in the kidney.

Photochemical and oxidative degradation of the solid-state tretinoin tocoferil

The photostability of tretinoin tocoferil was investigated under irradiation with three kinds of lamps, i.e., a cool white fluorescent lamp, a UV-A fluorescent lamp and a D65 fluorescent lamp. A combination of the cool white fluorescent lamp and the UV-A fluorescent lamp, and the D65 lamp having relative spectral power distribution similar to that of direct daylight, correspond to options 2 and 1 in ICH Guidelines, respectively. The photodegradation apparently followed second-order kinetics under these light sources and the degradation rate constant under exposure by the D65 lamp was larger than that by the cool white fluorescent lamp. The drug was susceptible to degradation by visible and UV light below 480 nm and was degraded most remarkably at around 420 nm, showing a wavelength-dependency. The semi-logarithmic plots of apparent degradation rate constant against the reciprocal of illuminance showed a good linear relationship in the Arrhenius-type fashion, and the photostability under ordinary illumination conditions could be predicted from the data obtained under the accelerated illumination conditions. The rate of oxidative degradation was slightly accelerated with the rise of temperature. Thermodynamic parameter was calculated from the Arrhenius plot. The degradation rate constant rapidly increased in proportion to partial pressure of oxygen below 20 kPa.

Histological Investigation of Endothelial Cell Proliferation on the Coil Surface after Endovascular Treatment Using FactorXIII. Preliminary Results in Swine Model

SUMMARY

Recently, endovascular treatment of coil embolisation has been widely used for obliterating cerebral aneurysms. However, the process of endothelial cell growth within aneurysms to prevent aneurysmal rupture associated with endovascular coil embolisation remains unclear. Fourteen aneurysms were produced in seven matured swine and embolised with Guglielmi Detachable coils (GDCs). The aneurysms were resected either immediately or three weeks after coil embolisation, and subjected to histological and scanning electron microscopic examinations. Blood coagulation factor XIII was administered in four animals on the day of embolisation and on the following four days. These aneurysms were also resected three weeks after the embolisation and investigated histologically. Marked fibroblast proliferation and growth of endothelial cells on the intraluminal surface of the coil were observed more often in the group administered factor XIII than in those not given factor XIII. These results suggest that administration of factor XIII may contribute to more effective aneurysm obliteration during coil embolisation.

Increased expression of cyclooxygenase-2 protein in 4-nitroquinoline-1-oxide-induced rat tongue carcinomas and chemopreventive efficacy of a specific inhibitor, nimesulide

Expression of cyclooxygenase (COX)-2 protein in 4-nitroquinoline-1-oxide (4-NQO)-induced rat tongue lesions and the postinitiation chemopreventive potential of a selective COX-2 inhibitor, nimesulide (NIM), were examined in Fischer 344 male rats. NIM was administered in the diet at doses of 150, 300, and 600 ppm for 14 weeks after treatment with 25-35 ppm 4-NQO in the drinking water for 12 weeks. Western blot analysis revealed COX-2 protein to be barely expressed in the normal tongue epithelia, whereas it was increased approximately 6-fold in squamous cell carcinomas (SCCs). Immunohistochemically, COX-2 protein was diffusely present in SCCs and dysplasia but expressed only in basal cells in hyperplasia and papillomas. In basal cells of normal epithelia, it was also occasionally weakly stained. NIM dose-dependently decreased at doses of 150 and 300 ppm, the incidences of SCCs to 4 of 12 (33.3%) and 1 of 13 (7.7%) and their multiplicity to 0.33+/-0.49 and 0.08+/-0.28 per rat, respectively, as compared with 4-NQO alone group values of 9 of 11 (81.8%) and 1.00+/-0.77. A lesser decrease was observed with 600 ppm, the values being 5 of 12 (41.7%) and 0.50+/-0.67. NIM did not significantly affect the development of hyperplasias, dysplasias, and papillomas. These results clearly indicate chemopreventive potential of a selective COX-2 inhibitor against the postinitiation development of SCCs in rat tongue carcinogenesis.

[Prolonged use of paclitaxel for platinum-refractory ovarian cancer--brief report]

The patient was a 41-year-old women with platinum-refractory ovarian cancer. She received 135-210 mg/m2 paclitaxel for 13 cycles. She received granulocyte colony-stimulating factor (G-CSF) support to prevent severe granulocytopenia, and experienced little neurologic toxicity. Her quality of life was good throughout the prolonged period of use of paclitaxel.

Increased oxidative DNA damage in mammary tumor cells by continuous epidermal growth factor stimulation

BACKGROUND

Growth factors can enhance the malignant potential of tumor cells. To examine the relationship between growth factors and tumor progression, we previously established a weakly malignant cell line, ER-1. We found that a 24-hour exposure of ER-1 cells to epidermal growth factor (EGF) induced malignant properties (tumor progression) that were reversible but that, after a 1-month exposure, these changes were irreversible. In this study, we investigated the irreversible changes induced in ER-1 cells by a 1-month exposure to EGF and the possible involvement of oxidative stress.

METHODS

ER-1 cells were treated with EGF (100 ng/mL) for 1 month in the presence or absence of an antioxidant, N-acetylcysteine or selenium, and compared with untreated control ER-1 cells. We assessed tumor progression by measuring intracellular peroxide levels, 8-hydroxydeoxyguanosine (a marker for oxidative DNA damage) levels, in vitro invasiveness, and in vivo tumorigenicity and metastatic ability. All statistical tests are two-sided.

RESULTS

After ER-1 cells were treated for 1 month with EGF, levels of intracellular peroxide and 8-hydroxyguanosine in the DNA of treated cells were higher than those in the DNA of control cells, and treated ER-1 cells were more tumorigenic and metastatic in vivo and more invasive in vitro than untreated control cells (all P<.001). Levels of 8-hydroxyguanosine in DNA increased as the length of the EGF treatment increased (P<.001). However, when N-acetylcysteine or selenium was added with EGF for 1 month, levels of intracellular peroxide and 8-hydroxyguanosine in DNA were comparable to those in control cells (r =.795). Both tumorigenicity (P =.008) and metastatic ability (P<.001) decreased after addition of N-acetylcysteine or selenium.

CONCLUSION

The irreversible changes caused by continuous EGF stimulation of ER-1 cells result from increased oxidative damage in the DNA, which generates tumor cells with more malignant characteristics.

Absence of PTEN/MMAC1 gene mutations in lung adenocarcinomas induced by N-nitrosobis(2-hydroxypropyl)amine in rats

Mutations of the phosphatase and tensin homolog deleted on chromosome ten/mutated in multiple advanced cancers 1 (PTEN/MMAC1) gene were investigated in lung adenocarcinomas induced by N-nitrosobis(2-hydroxypropyl)amine (BHP) in rats. Male Wistar rats (6 weeks old) were given 2000 ppm BHP in their drinking water for 12 weeks and maintained without further treatment until they were killed at week 25. Total RNA was extracted from 15 adenocarcinomas and mutations of the PTEN/MMAC1 gene were investigated by reverse transcription-polymerase chain reaction-restriction-single-strand conformation polymorphism analysis. No mutations were detected, and loss or decrease of expression of PTEN/MMAC1 mRNA was also not found in any of the cases. These results suggest that alterations of the PTEN/MMAC1 gene may not be involved in the development of adenocarcinomas induced by BHP in rats.

Increased susceptibility of poly(ADP-ribose) polymerase-1 knockout mice to nitrosamine carcinogenicity

The involvement of poly(ADP-ribose) polymerase-1 (Parp-1), one of the poly(ADP-ribose) polymerase family proteins, in genomic stability, DNA repair and cell death triggered by DNA damage has been well documented. However, the potential role of Parp-1 in carcinogenesis has not been well evaluated. In this study the carcinogenic activity of N:-nitrosobis(2-hydroxypropyl)amine (BHP) was studied in Parp-1(-/-) mice, generated by disrupting P:arp-1 gene exon 1. Parp-1(-/-) and Parp-1(+/+) male mice received 0, 250 and 500 p.p.m. BHP in their drinking water for 20 weeks and were then killed. The percentage of animals bearing hemangiomas and hemangiosarcomas in the liver and numbers of tumors per mouse were markedly higher in the Parp-1(-/-) groups given 250 or 500 p.p.m. BHP than in their Parp-1(+/+) counterparts. Hemangiosarcomas developed only in Parp-1(-/-) mice. In the lung the numbers of adenomas per mouse were increased in Parp-1(-/-) mice given BHP at 250 and 500 p.p.m. (P < 0.01) compared with the Parp-1(+/+) case. The results show that susceptibility to BHP is significantly elevated in Parp-1(-/-) mice, thus providing direct evidence that Parp-1 is relevant to carcinogenesis.

Alterations of the transforming growth factor-beta signaling pathway in hepatocellular carcinomas induced endogenously and exogenously in rats

To elucidate involvement of the transforming growth factor-beta (TGF-beta) signaling pathway in endogenous and exogenous liver carcinogenesis, we investigated mutations of TGF-beta receptor type II (TGF-betaRII), Smad2 and Smad4 genes, and expression of TGF-betaRII in hepatocellular carcinomas (HCCs) induced by a choline-deficient L-amino acid-defined (CDAA) diet and by N-nitrosodiethylamine (DEN). Male Fischer 344 rats received a CDAA diet continuously and HCCs were sampled after 75 weeks. Administration of DEN was followed by partial hepatectomy (PH), with colchicine to induce cell cycle disturbance and a selection pressure regimen, HCCs being obtained after 42 weeks. Total RNAs were extracted from individual HCCs and mutations in TGF-betaRII, Smad2 and Smad4 were investigated by reverse transcription (RT)-polymerase chain reaction (PCR)-restriction-single-strand conformation polymorphism (SSCP) analysis followed by sequencing analysis. Mutations of Smad2 were detected in 2 out of 12 HCCs (16.7%) induced by the CDAA diet, a GGT-to-GGC transition (Gly to Gly) at codon 30 and a TCT-to-GCT (Ser to Ala) transversion at codon 118, without any TGF-betaRII or Smad4 alterations. No mutations of TGF-betaRII, Smad2 and Smad4 were encountered in eleven HCCs induced by the exogenous carcinogen. Semi-quantitative RT-PCR revealed reduced expression of TGF-betaRII in 2 HCCs (16.7%) without Smad2 mutations out of 12 HCCs induced by the CDAA diet and none of 11 induced by DEN. These results suggest that the TGF-beta signaling pathway may be disturbed in endogenous liver carcinogenesis in rats.

Sodium sensitivity related to albuminuria appearing before hypertension in type 2 diabetic patients

OBJECTIVE

To find whether sodium sensitivity of blood pressure appears before hypertension and whether the sensitivity is related to diabetic nephropathy, we examined type 2 diabetic patients with normal levels of serum creatinine.

RESEARCH DESIGN AND METHODS

A total of 32 patients were divided into three age-matched groups: 11 patients had normoalbuminuria, 12 had microalbuminuria, and 9 had macroalbuminuria. Patients stayed on a diet with ordinary sodium levels for 1 week and a sodium-restricted diet for 1 week, in random order. Urinary excretion of sodium and albumin and systemic blood pressure were measured daily. A pressure-natriuresis curve was drawn by linkage of the two datum points obtained in the steady state during the different diets. We calculated the sodium sensitivity index as the reciprocal of the slope of this curve.

RESULTS

The median sodium sensitivity index and the mean blood pressure were higher in micro- and macroalbuminuric patients than in normoalbuminuric patients. Eighteen patients were without hypertension (<140/90 mmHg); of these, 10 had blood pressure readings <130/85 mmHg with ordinary sodium levels. Urinary albumin was correlated with the index but not with blood pressure. For these 10 patients, the index in those with albuminuria was higher than in those with normoalbuminuria. In such patients with albuminuria, sodium restriction decreased albuminuria and blood pressure.

CONCLUSIONS

In type 2 diabetic patients with albuminuria but normal levels of serum creatinine, sodium sensitivity of blood pressure appears before hypertension and is related to albuminuria; sodium restriction is one treatment for diabetic nephropath, even without hypertension.

[Efficacy of axillary-axillary bypass grafting for the subclavian artery disease]

Axillary-axillary bypass procedure was performed in 5 patients (3: atherosclerosis, 1: rupture of aortic arch aneurysm, 1: trauma) with the total occlusion of the subclavian artery. All the operations were performed with 6 mm ringed expanded polytetrafluoroethylene under general anesthesia. Though several types of extrathoracic procedures such as carotid-subclavian bypass, subclavian-subclavian bypass and axillary-axillary bypass are introduced, the efficacy of axillary-axillary bypass procedure is greater ease of anatomic exposure with no concern of interfering with the carotid circulation. The type of bypass to be used in a given case will depend on the individual circumstances. We suggest that this procedure is minimally invasive as well as effective for subclavian artery occlusion depending on the case.

Bone induction by Escherichia coli -derived recombinant human bone morphogenetic protein-2 compared with Chinese hamster ovary cell-derived recombinant human bone morphogenetic protein-2

Most recombinant human bone morphogenetic protein (rhBMP) is currently obtained from Chinese hamster ovary (CHO) cells. If rhBMP with more activity could be derived from Escherichia coli (E. coli), a large quantity of rhBMP could be produced at low cost. The bone-inducing ability of an E. coli -derived rhBMP-2 (ErhBMP-2) variant with an N-terminal sequence was examined and compared with CHO cell-derived rhBMP-2 (CrhBMP-2). Two, 10, or 50 microgram of ErhBMP-2 or CrhBMP-2 was mixed with 3mg of atelopeptide type I collagen as the carrier, and specimens were implanted into the calf muscle pouches of Wistar rats (n= 5 in each group). Three weeks later, new bone had formed in all the ErhBMP-2-implanted and CrhBMP-2-implanted muscles. Radiographic and histological examinations showed that the bone induced by ErhBMP-2 had a large hollow bone matrix with more fatty marrow than the bone induced by CrhBMP-2. Quantitative analysis indicated that the activity of ErhBMP-2 was similar to that of CrhBMP-2, so ErhBMP-2 may be useful for inducing bone formation.

Influence of peripheral vascular occlusive disease on the morbidity and mortality of coronary artery bypass grafting

The impact of peripheral vascular occlusive disease (PVD) on outcome for patients who have undergone coronary artery bypass grafting (CABG) was assessed by comparing preoperative and intraoperative patient characteristics and outcome in 2 groups of patients who underwent CABG (patients with PVD, n=96; patients without PVD, n=593). Patients with PVD were significantly older (69+/-8.4 vs 63+/-8.7; p<0.0001), and had a higher incidence of diabetes mellitus (48% vs 32%; p<0.01), hypertension (62% vs 46%; p<0.01), preoperative cerebral infarction (26% vs 12%; p<0.001) and chronic renal dysfunction (11% vs 4.4%; p<0.01) than those without PVD. Postoperative morbidity and mortality were assessed, after those risk factors were adjusted, using multivariate logistic regression analysis. The perioperative myocardial infarction (PMI) rate and in-hospital mortality rate were significantly higher in patients with PVD than in patients without PVD (9.4% vs 3.0%; p=0.0108, 17% vs 2.7%; p=0.0003, respectively). The odds ratio of PMI and in-hospital mortality were 3.4 (95% confidence intervals (CI): 1.3-8.6) and 4.3 (95% CI: 2.0-9.5), respectively. Although the excess mortality rate was mainly the result of cardiac problems, such as low output syndrome or arrhythmia, in most of the cases, PVD, which may frequently prevent the use of the intraaortic balloon pump, also seemed to have a strong relation to postoperative morbidity and mortality.

Mutations of adenomatous polyposis coli and beta-catenin genes during progression of lung tumors induced by N-nitrosobis(2-hydroxypropyl)amine in rats

In the present study, we investigated mutations of the adenomatous polyposis coli (APC) and beta-catenin genes to clarify possible molecular mechanisms underlying development of lung tumors induced by N-nitrosobis(2-hydroxypropyl)amine (BHP) in rats. Male Wistar rats, 6 weeks of age, were given 2000 ppm BHP in drinking water for 12 weeks and then maintained without further treatment until sacrifice at week 25 DNA was extracted from paraffin-embedded tissues, and PCR-single-strand conformation polymorphism analysis, followed by nucleotide sequencing, was performed. No APC mutations were detected in 17 hyperplasias, but 2 of 15 adenomas (13.3%) and 8 of 20 adenocarcinomas (40.0%) showed changes within exon 1 to the mutation cluster region in exon 15. For beta-catenin, no mutations were detected in 17 hyperplasias, but 3 of 15 adenomas (20.0%) and 5 of 20 adenocarcinomas (25.0%) had alterations within or flanking codons corresponding to important phosphorylation sites. Immunohistochemical staining showed beta-catenin protein localized in the cell membranes in the surrounding normal-appearing lung and 216 hyperplasias and localized mainly in the cytoplasm and/or nucleus in 10 of 37 adenomas (27.0%) and 21 of 40 adenocarcinomas (52.5%). These results suggest that the APC-beta-catenin-T-cell factor signaling pathway is involved in the acquisition of growth advantage from adenomas to adenocarcinomas in BHP-induced rat lung carcinogenesis.

Electromicroscopic Investigation of the Efficacy of FactorXIII for Coil Embolization in Experimental Aneurysms. Preliminary Report

SUMMARY

In recent years, endovascular treatment has often been used to treat cerebral aneurysms. Basic investigation to elucidate the process of endothelial cell growth within aneurysms is a crucial problem.We performed elecrtro-detachable coil embolization in aneurysms under administration of blood coagulation factorXIII, a wound-healing accelerator, and examined changes in endothelial cells on the surface of the inserted coil with a scanning electron microscope. Experimental aneurysms produced in animals were treated by coil embolization and histological changes in embolized coil after the treatment of factorXIII were investigated. Aneurysms were produced in four matured swines under general anesthesia and coil embolization was performed with a elecrtro-detachable coil. The aneurysms were resected immediately and 3 weeks after coil embolization, and investigated histologically with a scanning electron microscope. Seven animals were administrated with blood coagulation factorXIII on the day of embolized and the following 4 consecutive days. These aneurysms were also resected 3 weeks after embolization and investigated histologically. More marked fibroblast proliferation and growth of endothelial cells on the surface of luminal side of embolized coil were seen in the aneurysms in the group administrated with factorXIII than in aneurysms treated without factorXIII. More effective and sufficient coil embolization can be obtained by administration of factorXIII.

[Evaluation of right ventricular function by intraoperative transesophageal echocardiography for patients with left ventricular dysfunction]

We evaluated right and left ventricular function by intraoperative transesophageal echocardiography for the patients with left ventricular dysfunction (left ventricular ejection fraction (LVEF) < or = 40) who underwent isolated coronary artery bypass grafting (CABG). We divided these patients into two groups; group 1 who had difficulty of weaning from cardiopulmonary bypass due to hypotension (n = 8) and group 2 who did not have any difficulty of it (n = 17). Basement characteristics (age, gender, history of myocardial infarction, congestive heart failure, LVEF, severity of the right coronary artery disease) of both groups were not different significantly. Intraoperative characteristics (the number of distal anastomoses, duration of aortic cross-clamp and cardiopulmonary bypass, and bypass to the right coronary artery) were also not different between two groups. However, mean duration of ICU stay and in-hospital mortality were significantly longer and higher in group 1 than group 2. On the other hand, right ventricular systolic function was severely impaired, particularly postoperatively, in group 1 compared with group 2. Right and left ventricular systolic function of group 2 was fairly improved postoperatively. These results may indicate that right ventricular dysfunction is a potent predictor of postoperative morbidity and mortality for the patients with left ventricular dysfunction who undergo isolated CABG.

Mutations and reduced expression of the transforming growth factor-beta receptor II gene in rat lung adenocarcinomas induced by N-nitrosobis-(2-hydroxypropyl)amine

Mutations and expression of the transforming growth factor-beta receptor type II (TGF-beta RII) gene were investigated in lung adenocarcinomas induced by N-nitrosobis(2-hydroxypropyl)amine (BHP) in rats. Males of the Wistar strain, 6 weeks old, were given 2000 ppm of BHP in their drinking water for 12 weeks and then maintained without further treatment until killed at week 25. Total RNA was extracted from 12 adenocarcinomas and mutations in TGF-beta RII were investigated by RT-PCR-restriction-SSCP analysis followed by sequencing analysis. Two out of 12 adenocarcinomas showed band shifts, indicative of mutations (16.7%). One was a CTG-to-TTG (Leu to Leu) transition at codon 308 without amino acid alteration and the other a frameshift deletion of one of two guanines at nucleotides 1434 to 1435 (codon 477 to 478). Semi-quantitative RT-PCR analysis demonstrated significantly reduced TGF-beta RII expression in adenocarcinomas, as compared with normal lung tissue. These results suggest that TGF-beta RII alterations may play a role in the acquisition of growth advantage by lung adenocarcinomas induced by BHP in rats.

Increases in 1,5-anhydroglucitol levels in germinating amaranth seeds and in ripening banana

To examine whether 1,5-anhydroglucitol (AG) is derived from starch degradation in plant tissues, we colorimetrically measured AG contents of germinating amaranth seeds and ripening banana pulp. In both cases, as starch degradation proceeded, AG levels were significantly increased, but were 1,700-5,000 times lower than those of total soluble carbohydrates. alpha-1,4-Glucan lyase activity, which is measured by the 1,5-anhydrofructose (AF) liberated from non-reducing glucose residues of starch or glycogen, was too low to be detected in amaranth or banana by the 3,5-dinitrosalicylic acid method. On the other hand, AF reductase, which reduces AF to AG, was detected in germinating amaranth seeds and banana pulp. Thus, the increases in AG levels are conceived to be derived from starch breakdown, although further investigation is needed to answer whether the starch degradation pathway via alpha-1,4-glucan lyase/AF reductase exists in plant tissues.

Inhibitory effect of various thrombin inhibitors on shear-induced platelet function and dynamic coagulation

We assessed the effects of active site-directed, fibrinogen recognition exosite (FRE)-directed and bifunctional thrombin inhibitors, on shear-induced platelet reactivity (adhesion/aggregation) and dynamic coagulation (coagulation of flowing blood). An in vitro test for shear-induced haemostatic plug formation and dynamic coagulation (haemostatometry) was employed using non-anticoagulated rat blood. The active site-directed inhibitors (argatroban, P891, P899) caused inhibition of platelet reactivity and coagulation at 1-, 100- and 100-microM concentrations, respectively. Bifunctional inhibitors (P553, P1053) exerted inhibitory effects at 0.1 microM. A dimeric bifunctional inhibitor P824 caused significant inhibition at 1 microM. The FRE-directed inhibitor (P960) inhibited shear-induced platelet reactivity at 10 microM but the dynamic coagulation at 1 microM. Combination of active site-directed argatroban and FRE-directed P960 did not show any synergistic effect. The most potent inhibition was observed in monomeric bifunctional inhibitors. The inhibitory effects were compared with the K(i) values against human thrombin and with the IC(50) values against fibrin clot formation. The minimum effective concentrations on shear-induced platelet reactivity and dynamic coagulation were comparable with the IC(50) values, but not with the K(i) values.

Enhancement of hepatocarcinogenesis initiated with diethylnitrosamine or N-nitrosobis(2-hydroxypropyl)amine by a choline-deficient, L-amino acid-defined diet administered prior to the carcinogen exposure in rats

Effects of pre-administration of a choline-deficient, L-amino acid-defined (CDAA) diet on hepatocarcinogenesis initiated with diethylnitrosamine (DEN) or N-nitrosobis(2-hydroxypropyl)amine (BHP) in rats were investigated. A pre-administrating period was set as 1 week, because CDAA diet induces liver injuries by this time-point. In a time-course study, male Fischer 344 rats, 6 weeks old, received a 1-week pre-administration of choline-supplemented, L-amino acid-defined (CSAA) or CDAA diet, DEN at a dose of 100 mg/kg body weight by a single intraperitoneal injection, then CSAA or CDAA diet for up to 8 weeks, and were sacrificed 4, 6 and 8 weeks after DEN. CDAA diet administered only after DEN significantly increased the numbers of glutathione S-transferase placental form (GST-P)-positive lesions 4, 6 and 8 weeks after DEN and their sizes 6 and 8 weeks after DEN. CDAA diet administered both before and after DEN similarly increased the numbers and sizes of GST-P-positive lesions, but with a significantly greater degree than obtained by the diet administered only after DEN. In a dose response study, rats received vechicle or DEN, at a dose of 0.001, 0.01, 0.1, 1, 10, 20, 50, 100 or 200 mg/kg body weight, 1 week after the commencement of CSAA or CDAA diet, and sacrificed 8 weeks after vehicle or DEN. The significant increases of the numbers of GST-P-positive lesions were obtained after 50-200 mg/kg body weight of DEN under the CSAA diet administration, whereas those were detected after 10-200 mg/kg under CDAA diet administration. Sizes became significantly larger with only 200 mg/kg body weight of DEN in the CSAA case but with 50-200 mg/kg in the CDAA case. Male Wistar rats received a 1-week pre-administration of CSAA or CDAA diet, vehicle or BHP, at a dose of 600 or 1200 mg/kg body weight, by a single intraperitoneal injection, then CSAA or CDAA diet for 8 weeks, and were then sacrificed. The numbers of GST-P-positive lesions demonstrated significant increment with 1200 mg/kg body weight of BHP by CDAA diet administered only after BHP and, to a significantly greater degree, by the diet administered both before and after BHP. While CDAA diet administered only after BHP did not alter the sizes of GST-P-positive lesions, the diet administered both before and after 600 and 1200 mg/kg body weight of BHP significantly increased the sizes of the lesions. These results indicate that the pre- plus post-administration of CDAA diet enhances hepatocarcinogenesis initiated with DEN or BHP, more than the post-administration only, thus providing a sensitive model to detect weak liver carcinogenic potency of environmental chemicals.

Primary leiomyosarcoma of the pulmonary artery mimicking massive pulmonary thromboembolism

A 57-year-old man with dyspnea and dry cough exhibited pulmonary embolism. Pulmonary arteriography demonstrated absent perfusion of the left main and the right upper and middle lobe pulmonary arteries. A diagnosis of chronic pulmonary thromboembolism was assumed and surgical thromboendarterectomy was attempted under standard cardiopulmonary bypass. At operation, a tumor had invaded far into both the right and left pulmonary arteries and radical resection was impossible. The final pathological diagnosis was primary leiomyosarcoma of the pulmonary artery. The patient refused any adjuvant therapy and died 63 days after the surgery. The clinical presentation of this case was similar to that of pulmonary thromboembolism and its diagnosis and treatment were very difficult.