Dynamics of maternal and paternal effects on embryo and seed development in wild radish (Raphanus sativus).

BACKGROUND AND AIMS: Variability in embryo development can influence the rate of seed maturation and seed size, which may have an impact on offspring fitness. While it is expected that embryo development will be under maternal control, more controversial hypotheses suggest that the pollen donor and the embryo itself may influence development. These latter possibilities are, however, poorly studied. Characteristics of 10-d-old embryos and seeds of wild radish (Raphanus sativus) were examined to address: (a) the effects of maternal plant and pollen donor on development; (b) the effects of earlier reproductive events (pollen tube growth and fertilization) on embryos and seeds, and the influence of embryo size on mature seed mass; (c) the effect of water stress on embryos and seeds; (d) the effect of stress on correlations of embryo and seed characteristics with earlier and later reproductive events and stages; and (e) changes in maternal and paternal effects on embryo and seed characteristics during development. METHODS: Eight maternal plants (two each from four families) and four pollen donors were crossed and developing gynoecia were collected at 10 d post-pollination. Half of the maternal plants experienced water stress. Characteristics of embryos and seeds were summarized and also compared with earlier and later developmental stages. KEY RESULTS: In addition to the expected effects of the maternal plants, all embryo characters differed among pollen donors. Paternal effects varied over time, suggesting that there are windows of opportunity for pollen donors to influence embryo development. Water-stress treatment altered embryo characteristics; embryos were smaller and less developed. In addition, correlations of embryo characteristics with earlier and later stages changed dramatically with water stress. CONCLUSIONS: The expected maternal effects on embryo development were observed, but there was also evidence for an early paternal role. The relative effects of these controls may change over time. Thus, there may be times in development when selection on the maternal, paternal or embryo contributions to development are more and less likely.

The chondroprotective effects of ferulic acid on hydrogen peroxide-stimulated chondrocytes: inhibition of hydrogen peroxide-induced pro-inflammatory cytokines and metalloproteinase gene expression at the mRNA level.

OBJECTIVE: The objective of the study is to evaluate the effect of ferulic acid (FA), an antioxidant from the Chinese herb Dong-Gui [Chinese angelica, Angelica sinensis (Oliv.) Diels], on the regulation of various genes in hydrogen peroxide-stimulated porcine chondrocytes at the mRNA level. METHODS: The effect of FA and the effective concentration of FA on porcine chondrocytes was evaluated by the lactate dehydrogenase, WST-1, crystal violet assay, and a chemical luminescence assay. Gene expression in hydrogen peroxide-stimulated chondrocytes either pre- or post-treated with FA was evaluated by real-time PCR. RESULTS: Chondrocytes pre-treated with 40 microM FA decreased the hydrogen peroxide-induced interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha), and MMP-1 and partially restored SOX9 gene expression. Post-treatment with 40 microM FA also decreased the expression of MMP-1 and MMP-13. CONCLUSION: FA decreased the hydrogen peroxide-induced IL-1beta, TNF-alpha, MMP-1 and MMP-13 and increased SOX9 gene expression. These findings suggest that FA may prove to be important in the treatment of osteoarthritis. Further research is needed.

Rectal prolapse as initial clinical manifestation of colon cancer.

Rectal prolapse as the initial clinical manifestation of colorectal cancer is uncommon. We describe the case of a 75-year-old woman who was diagnosed as having adenocarcinoma of the sigmoid colon after presenting with complete rectal prolapse. The tumor caused rectosigmoid intussusception and then it prolapsed out through the anus. She underwent rectosigmoidectomy and rectopexy. The postoperative course was uneventful. The relationship between colorectal cancer and rectal prolapse has not been clearly established. This case report describes an unusual presentation of colorectal cancer. It suggests that rectal prolapse can present as the initial symptom of colorectal cancer and may also be a presenting feature of the occult intra-abdominal pathology. The importance of adequate investigation such as colonoscopy should be emphasized in patients who develop a new onset of rectal prolapse.

Differential effects of allyl sulfides from garlic essential oil on cell cycle regulation in human liver tumor cells.

In this study, diallyl sulfide (DAS), diallyl disulfide (DADS) and diallyl trisulfide (DATS), which are major organosulfur compounds (OSCs) of garlic, were used as experimental materials to investigate their modulation effects on cell viability and cell cycle in human liver tumor cells (J5). According to the results of cell viability assay, 50 or 100 microM DATS significantly decreased the cell viability as compared with the control (P < 0.05) in dose and time dependent relations. Phenomena of cell number loss, shape deformation and lysis were observed after treatment with 100 microM DATS for 24 h. Cell cycle studies showed that J5 cells were significantly arrested in G2/M phase as the cells were treated with 100 microM DADS, 10, 50 or 100 microM DATS for 24 h (P < 0.05). DATS was more effective in arresting cells in G2/M phase than DADS, and the phenomena of arresting J5 cells in G2/M phase increased obviously in dose and time dependent relations. According to the Western blot analysis, DATS decreased cyclin-dependent kinase (Cdks)-Cdk7 (i.e. Cdc2 activate kinase) protein levels in J5 cells but increased cyclin B1 protein level. The modulation potency to cyclin B1 and Cdk7 expressions was in the order of DATS > DADS > DAS. The modulation potency to cyclin B1 and Cdk7 protein levels increased with increasing in DATS concentration and culture time. In conclusion, DATS might affect cell viability and cell morphological changes in J5 cells and lead cells to be arrested in G2/M phase via controlling the expression of cyclin B1 and Cdk7 in J5 cells, and the controlling action might relate to the sulfuric atom numbers in the structures of all these allyl sulfides.

Tracing developing pathways in the brain: a comparison of carbocyanine dyes and cholera toxin b subunit.

The present study examined the efficiency of fluorescent carbocyanine dye 1,1'-dioctadecyl-3,3,3',3'-tetramethylinodocarbocyanine perchlorate and cholera toxin B subunit in tracing the crossed tectal projection to the nucleus rotundus of the thalamus (tectorotundal pathways) of paraformaldehyde-fixed and living chick embryos. The tracers were injected into the optic tectum under three experimental conditions (carbocyanine postfix, carbocyanine in vivo, and cholera toxin B subunit in vivo) and the anterograde transport of the nucleus rotundus was monitored and compared. In the carbocyanine postfix method, small crystals of carbocyanine dye were inserted into the tectum of paraformaldehyde-fixed embryos. A 6-month post-insertion period was required to label the crossed tectorotundal pathway. Results showed that tectal neurons did not begin to innervate the ipsilateral nucleus rotundus until embryonic day 9 and the contralateral nucleus rotundus until embryonic day 17. This slow progression of labeling through the crossed tectal projection resulted in significant contrast of the labeling between the ipsilateral and contralateral nuclei rotundus. In the carbocyanine in vivo method, a small volume of carbocyanine dye solution was injected into the tectum of living embryos. A 8- to 12-h survival period was sufficient enough to label the tectorotundal pathway. By embryonic day 8, the labeled axons terminated in the ipsilateral nucleus rotundus and the crossed tectorotundal projection was first detected by embryonic day 10. Similarly, in the cholera toxin B subunit in vivo method, a small volume of cholera toxin B subunit solution was injected into the tectum of living embryos. After a 6- to 10-h survival period, heavily labeled axons were found to innervate bilaterally the nucleus rotundus by embryonic day 8. This appeared to be the earliest schedule for detecting the crossed tectorotundal projection, compared with that of both the postfix and in vivo methods of carbocyanine dye. Based on the differences in the detectability of the crossed tectorotundal projection between the postfix and in vivo methods, the present data suggest that the former method is of limited purpose for labeling tectal collaterals during embryogenesis. Moreover, given the rapid transport rate and absence of photobleaching, which is often seen when using carbocyanine dye, the cholera toxin B subunit in vivo method appears to be the tracer of choice for investigating embryonic pathways.

Effect of diallyl sulfide and diallyl disulfide, the active principles of garlic, on the aflatoxin B(1)-induced DNA damage in primary rat hepatocytes.

The objective of this study was to investigate the effect of the active principles in garlic-- diallyl sulfide (DAS) and diallyl disulfide (DADS)--on aflatoxin B(1) (AFB(1))-induced DNA damage in primary rat hepatocytes. Primary rat hepatocytes, induced with DNA damage using 10 microM AFB(1) were used as an experimental model. According to the results of LDH leakage, 0.5 and 2 mM of DAS or 0.5 and 1 mM of DADS significantly increased the viability of hepatocytes compared with the AFB(1) controls after 4, 8 and 24 h treatment (P<0.05). According to the results of unscheduled DNA synthesis (UDS) test, 0.5 and 2 mM of DAS or 0.5 and 1 mM of DADS could significantly decrease the DNA damage induced by AFB(1) (P<0.05). Furthermore, 0.5 and 2 mM DAS or 0.5 and 1 mM DADS could increase the glutathione S-transferase (GST) and glutathione peroxidase (GPx) activities as compared with the AFB(1) controls after 24 h treatment (P<0.05). Results of immunoblot analysis of cytosolic GST isoenzyme indicate that the levels of GST isoform Ya, Yb2 and Yc were markedly increased after treatment with 0.5 and 2 mM DAS or 0.5 and 1 mM DADS compared with the AFB(1) control. These results indicate that 0.5 and 2 mM DAS or 0.5 and 1 mM DADS might protect hepatocytes from AFB(1)-induced DNA damage via increasing the activities of GST and GPx.

Ascorbic acid supplementation improved antibody response to infectious bursal disease vaccination in chickens.

The purpose of the present study was to determine if supplementation of ascorbic acid (AA) to the diet would have a beneficial effect on infectious bursal disease (IBD) vaccination of chickens for protection against infectious bursal disease virus (IBDV) infection. Two hundred forty specific pathogen-free (SPF) chickens were divided into eight experimental groups. A 2 x 2 x 2 factorial arrangement in a completely randomized design was used; AA supplementation at 1,000 ppm in the diet, vaccination, and challenge were the main effects. Prior to challenge and 10 d after challenge, serum AA concentration, serum corticosterone concentration, ELISA antibody titer to IBDV, body weight, bursa-to-body weight (B:B) ratio, and bursal histological score (BHS) were determined. Nonvaccinated chickens fed a diet supplemented with AA did not exhibit clinical signs or mortality following challenge, whereas AA-unsupplemented counterparts had 100% cumulative morbidity and 30% cumulative mortality. Serum AA levels of AA-supplemented and vaccinated chickens were significantly (P < 0.05) higher than AA-unsupplemented and vaccinated chickens. Fourteen days following vaccination, significantly (P < 0.05) higher ELISA titers to IBDV were observed in vaccinated chickens supplemented with AA as compared to AA-unsupplemented counterparts. Ascorbic acid-supplemented chickens, especially those also vaccinated, had higher body weight gains as compared to the AA-unsupplemented chickens. Ascorbic acid-supplemented chickens challenged with IBDV did not show any clinical signs or mortality. The results suggest that supplementation of AA at 1,000 ppm in the diet has beneficial effects on antibody response to IBD vaccination and body weight gain.

Effect of ascorbic acid supplementation on the immune response of chickens vaccinated and challenged with infectious bursal disease virus.

One-day-old chickens were divided into two groups and reared under similar conditions. One group was fed a diet supplemented with 1000ppm ascorbic acid and the other group was fed an identical diet, but not supplemented with ascorbic acid. Both groups were vaccinated against infectious bursal disease (IBD) at 7 days of age and challenged orally with 4x10(5) of 50% embryo-lethal-dose IBDV 14 days later. The number of anti-IBDV antibody secreting cells, production of interleukin-2 (IL-2) by splenocytes, number of CD4(+), CD8(+) and IgM(+) cells in spleen and IgM(+) cells in bursa of Fabricius were compared between the two groups at 7 days (prior to vaccination), 21 days (14 days post-vaccination and prior to challenge) and 31 days (10 days post-challenge) of age. The number of CD8(+) in spleen at 7 days of age and IgM(+) cells in bursa at 7, 21 and 31 days of age were significantly higher in ascorbic acid supplemented group (P<0.05). Production of IL-2 by splenocytes was higher as indicated by higher stimulation indices in ascorbic acid supplemented group. The number of anti-IBDV IgG antibody secreting cells in spleen at 21 and 31 days of age were significantly higher in ascorbic acid supplemented group (P<0.05). Dietary supplementation of ascorbic acid may ameliorate the immunosuppression caused by IBDV vaccination and improve humoral and cellular immune responses.

Atypical signaling defects prevent IL-2 gene expression in lpr/lpr CD4-CD8- cells.

T cells with CD4-CD8- (double negative, DN) phenotype in MRL-lpr/lpr mouse serve as a model to establish the correlation between the extremely low IL-2 gene expression and the specific signaling inactivation. The extent of nonresponsiveness in lpr DN cells was distinctive in several unusual defects. First, the poor IL-2 production in lpr DN cells could not be restored by supplement of signals known to augment IL-2 response in normal T cells. Second, the activations of both mitogen-activated protein (MAP) kinase and c-Jun N-terminal kinase (JNK) were attenuated in lpr DN cells upon direct activation by TPA/A23187. Third, IL-2 mRNA was degraded much faster in lpr DN cells than that in normal T cells. Fourth, of the four major transcriptional elements on IL-2 promoter, only AP-1 and nuclear factor of activated T cells (NFAT)-binding activities were suppressed in lpr DN T cells. Altogether, these results suggest that an extremely low level of IL-2 production in lpr DN T cells was due to both the increased instability of mRNA and the reduced activation of IL-2 gene promoter, the latter defect could be attributed to the inactivation of AP-1 and NF-AT as well as the poor activation of the upstream MAP kinase and JNK.

The thalamo-hyperstriatal system is established by the time of hatching in chicks (Gallus gallus): a cholera toxin B subunit study.

Connections of the thalamo-hyperstriatal system of hatchling chicks were investigated using multiple injections of cholera toxin B subunit (CTb) in the wulst. In the diencephalon, cells with CTb-like immunoreactivity (CTb-LI) were seen bilaterally in n. dorsolateralis anterior thalami, pars lateralis dorsalis and ventralis, n. dorsolateralis anterior thalami, pars magnocellularis, and pars lateralis rostralis. Within this complex, more CTb-LI cells were observed in the ventral portions of the ipsilateral side, whereas more labeled cells were found in the dorsolateral portions of the contralateral side. Moreover, CTb-LI cells were seen bilaterally in n. superficialis magnocellularis. In the nonvisual thalamic structures, numerous CTb-LI cells were seen in n. dorsolateralis anterior thalami, pars medialis and n. dorsolateralis posterior thalami. In the ventral thalamus, intense CTb-LI fibers/terminals were present in the external half of the external laminae of n. geniculatus lateralis, pars ventralis. Moderate to minor concentrations of fibrous labeling were found in n. intercalatus thalami and n. ventrolateral thalami. Moreover, efferent projections of the wulst were evident in the most ventral half of the optic tectum and the pretectal areas. The latter included n. pretectalis medialis, n. spiriformis medialis, n. principalis precommissuralis, n. lentiformis mesencephali, pars magnocellularis, and n. superficialis synecephali. Also, CTb-LI fibers were seen in n. basal optic root. The present study provides strong evidence that neuronal connections of the thalamo-hyperstriatal system are well established by the time of hatching. Additionally, efferent projections from the wulst to the diencephalic, mesencephalic, and pretectal structures are evident.

Beneficial effects of tetramethylpyrazine, an active constituent of Chinese herbs, on rats with endotoxemia.

Tetramethylpyrazine, an inhibitor of phosphodiesterase, has been widely used for treatment of cardiovascular diseases in China. Here, we investigate the effects of tetramethylpyrazine on hypotension, vascular hyporeactivity to norepinephrine (NE), release of tumor necrosis factor-alpha (TNF alpha) and nitric oxide (NO) in a rat model of circulatory shock induced by bacterial endotoxin (E. coli lipopolysaccharide, LPS). Male Wistar-Kyoto rats were anesthetized and instrumented for the measurement of mean arterial pressure (MAP) and heart rate (HR). Injection of LPS (10 mg/kg, i.v.) resulted in a fall in MAP and an increase of HR. In contrast, animals pretreated with tetramethylpyrazine (10 micrograms/kg, i.p. at 30 min prior to LPS) maintained a significantly higher MAP, but tachycardia was further enhanced at 60 min and 120 min when compared to rats given only LPS (LPS-rats). The pressor effect of NE (1 microgram/kg, i.v.) was also significantly reduced after treatment of rats with LPS. Similarly, the thoracic aorta obtained from rats after in vivo studies showed a significant reduction in the contractile responses elicited by NE (1 microM). Pretreatment of LPS-rats with tetramethylpyrazine partially, but significantly, prevented this LPS-induced hyporeactivity to NE in vivo and ex vivo. The injection of LPS resulted in a significant increase in the plasma TNF alpha level at 60 min, whereas the effect of LPS on the plasma nitrate (an indicator of NO formation) level increased in a time-dependent manner. This increment of both TNF alpha and nitrate levels induced by LPS was significantly reduced in LPS-rats pretreated with tetramethylpyrazine. The early hypotension caused by LPS was slightly, but significantly, prevented by pretreatment with tetramethylpyrazine, suggesting that tetramethylpyrazine affects the endothelial constitutive NOS (eNOS). This was examined by the effect of tetramethylpyrazine on acetylcholine (ACh, 1 microM)-induced relaxation in rats treated with tetramethylpyrazine for 4 h. However, tetramethylpyrazine had no significant effects on the ACh-induced relaxation, indicating that tetramethylpyrazine does not affect the activity of eNOS. Thus, tetramethylpyrazine attenuates the early hypotension and the delayed circulatory failure caused by endotoxin in the rat. These effects may be due to inhibition of the release of circulation factors and TNF alpha, which usually reveal synergism upon the induction of iNOS.

Functional development of the vibrissae somatosensory system of the rat: (14C) 2-deoxyglucose metabolic mapping study.

Functional development of the rat whisker somatosensory system was studied by using the (14C) 2-deoxyglucose (2DG) metabolic mapping technique. Restrained rat pups had their left mystacial vibrissae stroked for 30 minutes and their brains harvested, sectioned, and autoradiographed from the level of the lower medulla to the frontal cortex. Subjects were tested at postnatal days (PNDs) 0-9 and 21. At birth, all subjects exhibited a significant increase of 2DG uptake in the left spinal trigeminal nuclei, the principal trigeminal sensory nucleus, and a portion of the right ventral posteromedial thalamic nucleus. The primary somatosensory cortex exhibited significant 2DG uptake contralateral to stimulation by PND 6, followed by the secondary somatosensory cortex at PND 7. The pattern of 2DG uptake in the somatosensory cortices became more intense and well defined by PND 9. Given that the somatosensory system develops in an orderly fashion from the periphery to higher brain structures, the present results show that brain structures mediating whisker sensory input are not metabolically active until projections from lower somatosensory centers are established. Neurons become responsive to whisker stimulation in the subcortical structures at birth and in the somatosensory cortex a few days later. This cortical activity follows the organization of the upper tier of thalamocortical fibers into a "barrelfield." Moreover, there is a gradual enhancement in functional activity of the vibrissa neurons at different somatosensory nuclei as rats mature. The present study elucidates the time course of functional development in the rat somatosensory system.

Bacterial translocation in the course of acute pancreatitis: beneficial role of nonabsorbable antibiotics and lactitol enemas.

Two-hundred Wistar rats were allocated to 4 groups. The groups, 3 representing our acute pancreatitis model induced by intrabiliary injection of a trypsin/enterokinase mixture, were studied as follows: (A) no treatment; (B) given a daily 30-ml enema with 20 mg/kg rifaximin; (C) given a daily 30-ml enema with 20 mg/kg rifaximin plus lactitol 0.5 g/kg, and (D) given a daily 30-ml enema with warm saline. A further group of healthy rats was given an intrabiliary injection of 0.15 ml saline. Sacrifices were made after 6, 12, 24, 48 and 72 h of observation. Serial blood samples were drawn to measure pancreatic enzymes and endotoxin. At sacrifice, ascites, lymph nodes, pancreas, spleen, portal vein blood, arterial blood and bile were obtained for bacteriological culture. Both enema treatments brought about a significant improvement in survival. Enema treatments did not affect the serum level of pancreatic enzymes. A time-course increase in endotoxin level was observed in untreated rats. However, significantly decreased levels were observed after both enema treatments. Overall, ascites was the sample most frequently infected. Lymph nodes contiguous to the gut were found to be infected more frequently than those close to major vessels. The histological pancreatic damage was of a significantly lesser degree in both enema treatment groups. Virtually all severe necrotico-hemorrhagic pancreatic lesions were associated with bacterial infection. These data suggest that bacterial translocation plays a relevant role in the outcome of experimental necrotizing pancreatitis. Intra-abdominal spread and lymphatics seem to be the pathways most likely involved in such processes. Colonic cleansing by non-absorbable antibiotics and lactitol seems to exert a beneficial effect on the supervening infection of experimental necrotizing pancreatitis.

Neonatal capsaicin treatment alters the metabolic activity of subcortical somatosensory structures of developing rats in response to whisker stimulation.

Sprague-Dawley rats neonatally treated with capsaicin exhibited significant changes in 2-deoxy-glucose uptake in the subcortical somatosensory structures following repetitive whisker deflection. There was an increased uptake in the spinal trigeminal nucleus pars caudalis and a decrease in the principal sensory nucleus and the ventral posteromedial thalamic nucleus. The present study suggests that disruption of nociceptive afferents during development causes functional changes to subcortical somatosensory trigeminal nuclei.

Detection of pelvic deep vein thrombosis by subcutaneous radionuclide venography utilizing an acupuncture point.

The authors present a case of thrombosis involving the right common iliac vein evaluated with subcutaneous radionuclide venography (SCRNV) after injection at acupuncture points. SCRNV demonstrated interruption of venous flow to the right common femoral vein and right iliac vein with prominent collateral venous drainage into the contralateral deep veins. This technique, which is technically simple and relatively operator-independent, has the potential to become a screen or follow-up test for deep vein thrombosis.

Neonatal capsaicin treatment (NCT) alters the metabolic activity of the rat somatosensory cortex in response to mechanical deflection of the mystacial vibrissae.

Capsaicin, a selective neurotoxin of unmyelinated C-fibers, was administered to neonatal rat pups at birth. Following a recovery period of 10 days, pups were injected with 2-deoxy-glucose (2DG) and subjected to repetitive mechanical stimulation to the left whiskerpad. Their brains were then harvested for autoradiography. The observed changes in 2DG uptake in the somatosensory cortex of capsaicin-treated rats were compared to vehicle-treated rats. The cross-sectional area and density of 2DG uptake by the primary and the secondary somatosensory cortex (SSI and SSII, respectively) were measured. Capsaicin-treated rats significantly exhibited a reduction in area of activation and a decrease of 2DG uptake in both structures. The present data indicates that neonatal capsaicin affects the functional activity of the rat somatosensory cortex. It is suggested that unmyelinated sensory afferents play a role in the development of the rat somatosensory system.

Hypovolemic shock and mortality after ingestion of Tripterygium wilfordii hook F.: a case report.

Tripterygium wilfordii Hook F (TWHF) is a kind of Chinese herbal medicine used for 2000 years. It was applied externally for treatment of arthritis and inflammatory tissue swelling in early years. Recently, this drug has been found to have immunosuppressive effects which could successfully induce remission of some autoimmune disorders without obvious adverse effects. Although there are side effects of gastrointestinal upset, infertility and suppression of lymphocyte proliferation, little information about lethal toxicities has been reported. A case is presented here of a previously healthy young man who developed profuse vomiting and diarrhea, leukopenia, renal failure, profound hypotension and shock after ingestion of an extract of TWHF. In addition to his hypovolemic shock, serial electrocardiograms (ECG), cardiac enzyme studies, and echocardiography also showed some evidence of coexisting cardiac damage. He died of intractable shock 3 days after the abuse of TWHF. Further studies of the pathogenesis of peripheral collapse and possible cardiac toxicity, and determination of the therapeutic range of this drug are necessary before it is used extensively.

Aminoguanidine attenuates the delayed circulatory failure and improves survival in rodent models of endotoxic shock.

1. We have investigated the effects of aminoguanidine, a relatively selective inhibitor of the cytokine-inducible isoform of nitric oxide synthase (iNOS), on the delayed circulatory failure, vascular hyporeactivity to vasoconstrictor agents, and iNOS activity in a rat model of circulatory shock induced by bacterial endotoxin (E. coli lipopolysaccharide; LPS). In addition, we have evaluated the effect of aminoguanidine on the 24 h survival rate in a murine model of endotoxaemia. 2. Male Wistar rats were anaesthetized and instrumented for the measurement of mean arterial blood pressure (MAP) and heart rate (HR). Injection of LPS (10 mg kg-1, i.v.) resulted in a fall in MAP from 115 +/- 4 mmHg (time 0, control) to 79 +/- 9 mmHg at 180 min (P < 0.05, n = 10). The pressor effect of noradrenaline (NA, 1 microgram kg-1, i.v.) was also significantly reduced at 60, 120 and 180 min after LPS injection. In contrast, animals pretreated with aminoguanidine (15 mg kg-1, i.v., 20 min prior to LPS injection) maintained a significantly higher MAP (at 180 min, 102 +/- 3 mmHg, n = 10, P < 0.05) when compared to rats given only LPS (LPS-rats). Cumulative administration of aminoguanidine (15 mg kg-1 and 45 mg kg-1) given 180 min after LPS caused a dose-related increase in MAP and reversed the hypotension. Aminoguanidine also significantly alleviated the reduction of the pressor response to NA: indeed, at 180 min, the pressor response returned to normal in aminoguanidine pretreated LPS-rats. 3. Thoracic aortae obtained from rats at 180 min after LPS showed a significant reduction in the contractile responses elicited by NA (10-9- 10-6 M). Pretreatment with aminoguanidine (15 mg kg- 1, i.v.,at 20 min prior to LPS) significantly prevented this LPS-induced hyporeactivity to NA ex vivo.4. Endotoxaemia for 180 min resulted in a significant increase in iNOS activity in the lung from 0.6 +/- 0.2 pmol mg-1 min-1 (control, n = 4) to 4.8 +/- 0.3 pmol mg-1 min-1 (P<0.05, n = 6). In LPS-rats treated with aminoguanidine, iNOS activity in the lung was attenuated by 44+/- 5% (n = 6, P <0.05).Moreover, when added in vitro to lung homogenates obtained from LPS-rats, aminoguanidine and N omega-nitro-L-arginine methyl ester (L-NAME; 10-8 to 10-3 M) caused a concentration-dependent inhibition of iNOS activity (n = 3-6, IC50: 30 +/- 12 and 11 +/- 6pEM, respectively P>0.05). In contrast,aminoguanidine was a less potent inhibitor than L-NAME of the constitutive nitric oxide synthase in rat brain homogenates (n = 3-6, IC50 is 140 +/- 10 and 0.6 +/- 0.1 I1M, respectively, P<0.05). In addition, the inhibitory effect of aminoguanidine on iNOS activity showed a slower onset than that of L-NAME(maximal inhibition at 90 min and 30 min, respectively).5. Treatment of conscious Swiss albino (T/O) mice with a high dose of endotoxin (60 mg kg-1, i.p.)resulted in a survival rate of only 8% at 24 h (n = 12). However, therapeutic application of aminoguanidine (15 mg kg-1, i.p. at 2 h and 6 h after LPS) increased the 24 h survival rate to 75%(n = 8), whereas L-NAME (3 mg kg-1, i.p. at 2 h and 6 h after LPS) did not affect the survival rate(11%, n=9).6 Thus, aminoguanidine inhibits iNOS activity and attenuates the delayed circulatory failure caused by endotoxic shock in the rat and improves survival in a murine model of endotoxaemia. Aminoguanidine,or novel, more potent selective inhibitors of iNOS may be useful in the therapy of septic shock.

Antiplatelet effects of clausine-D isolated from Clausena excavata.

Clausine-D inhibited concentration-dependently the aggregation and release reaction of washed rabbit platelets induced by arachidonic acid and collagen, without affecting those induced by U46619, PAF and thrombin. The IC50 values of clausine-D on arachidonic acid- and collagen-induced platelet aggregation were calculated to be 9.0 +/- 1.1 and 58.9 +/- 0.9 microM, respectively. Thromboxane B2 and prostaglandin D2 formation in platelets caused by arachidonic acid were also suppressed. Clausine-D inhibited increased intracellular concentration of calcium in platelets caused by arachidonic acid and collagen, and also abolished the generation of inositol monophosphate caused by arachidonic acid, but not that by collagen, U46619, PAF and thrombin. In human citrated platelet-rich plasma, clausine-D inhibited the secondary phase, but not the primary phase, of aggregation induced by epinephrine and ADP. These results indicate that the antiplatelet effect of clausine-D is due to inhibition of the formation of thromboxane A2.

Subcutaneous radionuclide venography. An effective method for diagnosis of deep venous thrombosis.

Traditional acupuncture points K-3 are physiologically tender points located halfway between the Achilles tendon and the medial malleolus. Recently, the authors developed a new method of radionuclide venography of the lower limbs, namely subcutaneous radionuclide venography (SC-RNV), by subcutaneous injection of Tc-99m pertechnetate at these points. The authors applied this method in a patient with suspected deep vein thrombosis of both lower limbs. For comparison, ascending radionuclide venography by intravenous injection (IV-RNV) of Tc-99m MAA and color Doppler ultrasound were also done. The SC-RNV showed partial obstruction of right popliteal vein and complete obstruction of the left popliteal vein with prominent collateral flows. These results were compatible with the findings of color Doppler ultrasound. However, the IV-RNV showed small narrowing with patency of the left popliteal vein, and normal flow on the right. This suggests that the results of SC-RNV may be different from that of IV-RNV. The benefits of SC-RNV in the detection of deep vein thrombosis are described.