External validation of the prognostic index in acute paraquat poisoning

OBJECTIVE

Some studies have evaluated the prognostic indicators associated with acute paraquat (PQ) poisoning. In this study, we externally validated the Yamaguchi index, which showed a good prognostic relevance in predicting the outcome of PQ poisoning.

METHODS

A retrospective analysis of 297 patients was performed. The Yamaguchi index was calculated using the following equation: Eq1 = (K(+) × HCO3(-))/(Creatinine × 0.088)(mEq/L) against time from PQ ingestion (T). The patients were divided into three groups: group A: Eq1 > 1500 - 399 × log T, group B: 930 - 399 × log T < Eq1 ≤ 1500 - 399 × log T, and group C: Eq1 ≤ 930 - 399 × log T).

RESULTS

The overall mortality rate was 65.3% (194 of 297). The mortality rates of the three groups stratified by the Yamaguchi index were 7.1% (2 of 28), 22.4% (15 of 67), and 87.6% (177 of 202). The area under the receiver-operating characteristic curve for predicting mortality from the external validation of the Yamaguchi index was 0.842 (95% confidence interval: 0.795-0.882).

CONCLUSION

The Yamaguchi index is a reliable prognostic factor and could be helpful in predicting mortality due to PQ poisoning.

Proliferation and functional assessment of pseudo-islets with the use of pancreatic endocrine cells

Many obstacles beset islet transplantation, particularly insufficient tissue mass. Previously, we reported production of pseudo-islets. In addition, there have been reports in which coculture with pancreatic islet and bone marrow mesenchymal stem cells (BMSCs) demonstrated positive effects on pancreatic islet function. The purpose of this study was to perform morphologic and functional evaluations of pancreatic pseudo-islets cocultured with BMSCs. Pancreatic endocrine cells (PECs) were collected with a previously reported method; bone marrow was aspirated from the rat femur. Subsequently, PECs and BMSCs cocultured at high density on low-cell-binding culture dishes kept suspended by shaking. The functionality and characteristics of the mixed cell complexes were evaluated by glucose challenge, insulin enzyme-linked immunosorbent assay, reverse-transcription polymerase chain reaction, and immunohistochemistry. Through expansion for 2 weeks in continuous culture passages, ∼1 million PECs were recovered after aggregation. They presented spherical shapes and sizes similar to naïve islets, according to phase-contrast microscopy. The spheroid aggregates of pancreatic islet cells and BMSCs showed fortified functions and maintained viability. In conclusion, PECs served as a cell source for pseudo-islets, which were both morphologically and genetically similar to naïve islets. We also suggest a manufacturing method for mixed cellular complexes from 2 different origins that can improve secretion ability and cell differentiation.

Coenzyme Q10 ameliorates pain and cartilage degradation in a rat model of osteoarthritis by regulating nitric oxide and inflammatory cytokines

Objective

To investigate the effect of CoenzymeQ10 (CoQ10) on pain severity and cartilage degeneration in an experimental model of rat osteoarthritis (OA).

Materials and Methods

OA was induced in rats by intra-articular injection of monosodium iodoacetate (MIA) to the knee. Oral administration of CoQ10 was initiated on day 4 after MIA injection. Pain severity was assessed by measuring secondary tactile allodynia using the von Frey assessment test. The degree of cartilage degradation was determined by measuring cartilage thickness and the amount of proteoglycan. The mankin scoring system was also used. Expressions of matrix metalloproteinase-13 (MMP-13), interleukin-1β (IL-1β), IL-6, IL-15, inducible nitric oxide synthase (iNOS), nitrotyrosine and receptor for advanced glycation end products (RAGE) were analyzed using immunohistochemistry.

Results

Treatment with CoQ10 demonstrated an antinociceptive effect in the OA animal model. The reduction in secondary tactile allodynia was shown by an increased pain withdrawal latency and pain withdrawal threshold. CoQ10 also attenuated cartilage degeneration in the osteoarthritic joints. MMP-13, IL-1β, IL-6, IL-15, iNOS, nitrotyrosine and RAGE expressions were upregulated in OA joints and significantly reduced with CoQ10 treatment.

Conclusion

CoQ10 exerts a therapeutic effect on OA via pain suppression and cartilage degeneration by inhibiting inflammatory mediators, which play a vital role in OA pathogenesis.

Long-term viability of transplanted hybrid cellular spheroids within chondrocyte sheets

Encapsulation of transplanted cells within an immunoisolating membrane may provide a new strategy for protecting these cells from recipient immune responses without the use of immunosuppressive drugs. We have previously reported a novel concept of immunoisolation and immunodelusion using recipient cells instead of traditional artificial materials. We developed a chondrocyte sheeting immunodelusive immunoisolated bioartificial pancreas (CSI-BAP) that would enable transplantation of cells across allogeneic and xenogeneic barriers without the cells being recognized as donor cells and without the need for immunosuppression. Recently, we have constructed hybrid cellular spheroids (HCSs) containing cells from two different cell lines (RIN-5F, an insulin-secreting cell line, and Hep-G2, a hepatocellular carcinoma cell line) to enhance the function and biocompatibility of the HCSs. These HCSs were then encapsulated with multiple layers of chondrocyte sheets obtained from the auricular cartilage of Sprague-Dawley (SD) rats. The in vitro ability of the CSI-BAP to secrete insulin was tested before transplantation. Histological evaluation of CSI-BAP chondrocyte microencapsulated immunoisolated islet morphology and viability of allogeneic or xenogeneic cell lines was performed 100 days after the CSI-BAP was transplanted into SD rats. Morphological evaluations revealed good viability of the islets and progression of islet encapsulation. In vitro insulin secretion from the CSI-BAP was well maintained. Additionally, insulin and albumin secretion from the CSI-BAP was confirmed by in vivo immunohistochemical examination. Moreover, the cell lines transplanted into the subcutaneous space in the form of HCSs within the chondrocyte sheets showed good viability of more than 100 days and sustained insulin and albumin secreting ability.

First flatus time and xerostomia associated with gum-chewing after liver resection

AIMS AND OBJECTIVES

The aim of this study was to compare the return of bowel function and xerostomia in patients who were and were not instructed to chew gum after elective open liver resection.

BACKGROUND

Patients who undergo liver resection have limited early ambulation, because they require bed rest after surgery to prevent internal bleeding. They normally also require narcotic analgesics or patient-controlled analgesia for pain control. For these reasons, they often have symptoms of intestinal gas accumulation, abdominal distension and/or abdominal pain.

DESIGN

Prospective case-control study.

METHODS

Forty-two patients with hepatocellular carcinoma who were treated at Samsung Medical Center from September 2010 to February 2011 were included in this study. Patients who were scheduled for elective liver resection for hepatocellular carcinoma and were over 30 years of age were eligible. Patients were assigned to a gum-chewing group or a non-gum-chewing (control) group before surgery.

RESULTS

The mean age of the gum-chewing group was 54·9 (±9·7) years, and the mean age of the control group was 55·1 (±8·4) years. The mean values of first flatus time and xerostomia were higher in the control group than in the gum-chewing group. First flatus time and xerostomia grade were significantly decreased in gum-chewing group compared with the control group after adjustment for hospitalisation days, duration of surgery and amount of analgesics administered.

CONCLUSION

Patients who were instructed to chew gum after surgery demonstrated faster bowel function recovery and lower xerostomia grade after elective open liver resection than patients who did not chew gum.

RELEVANCE TO CLINICAL PRACTICE

Gum-chewing is an inexpensive, helpful adjunct to standard postoperative care after liver resection.

Microencapsulation of pancreatic islets with canine ear cartilage for immunoisolation

Improving human islet transplantation is often limited by the shortage of donors and the side effects of immunosuppressive agents. If immunoisolation is properly used, it can overcome these obstacles. Because artificial materials are adopted in this technique, however, there are still multiple issues with biocompatibility and foreign body reactions. We developed a chondrocyte microencapsulated immunoisolated islet (CMI-islet) that allows living cells to act as the immunoisolating material. To manufacture CMI-islets for xenotransplantation, isolated rat pancreatic islets were placed on low cell-binding culture dishes. Subsequently, expanded canine auricular cartiage primary cells were seeded on these dishes at a high density and maintained in a suspended state via a shaking culture system. Morphological evaluations showed good islet viability and a clear progression of the islet- encapsulation events. When the cells were challenged with glucose, they were able to secrete sufficient insulin according to glucose concentrations. The CMI-islets responded better to the glucose challenge than did nude pancreatic islets and created better glucose-insulin feedback regulation. Moreover, insulin secretion into the culture medium was confirmed over a period of 100 days, showing the survival and secretory capacity of the CMI-islet cells. By microencapsulating pancreatic islets with recipient ear cartilage cells, long-term insulin secretion can be maintained and the response to glucose challenges improved. This new immunodelusion technology differs from other immunoisolation techniques in that the donor tissue is enclosed with the recipient's tissue, thus allowing the transplanted cells to be recognized as recipient cells. This microencapsulation method may lead to developing viable xenotransplantation techniques that do not use immunosuppressive drugs.

Effect of precursor ratio on the structural properties of ZnO thin films deposited by low pressure MOCVD

The effect of precursor ratio (H2O/DEZ) on the texture orientation, surface morphology, optical transparency and electrical resistivity of ZnO thin films deposited by MOCVD was investigated. Deposition temperature and pressure were fixed at 120 degrees C and 0.67 torr, respectively. The precursor ratio was varied between 0.1 and 4. It was found that the texture orientation changed from (0002) to (1120) with increase of the precursor ratio. (1120) textured film shows well facetted tetrapod like rough surface morphology, which scatters the incident light very effectively. The electrical resistivity was in the range of about 0.1 omega cm in the undoped state, which was found to decrease with increase of the film thickness and decrease of the precursor ratio.

Change of telomerase activity in peripheral whole blood of head and neck squamous cell carcinoma patients before and after surgery: a pilot study

BACKGROUND The purpose of this study was to evaluate telomerase activity in peripheral whole blood from head and neck squamous cell carcinoma (HNSCC) patients as a biomarker for diagnosis of HNSCC or detection of recurrence during follow-up. MATERIALS AND METHODS Telomerase activity was measured from peripheral whole blood extracts by telomerase repeat amplification protocol (TRAP) in HNSCC patients before and after surgery and in a control group. Sixty-two HNSCC patients and 42 control subjects were included. RESULTS Telomerase activity was found in 41 out of 62 (66.1%) HNSCC patients before surgery and in 8 out of 42 (19.0%) controls (p<0.001). Among 41 HNSCC patients who showed positive telomerase activity before surgery, 32 (78.1%) showed a conversion of telomerase activity to negative after surgery. In follow-up, 6 out of 8 (75%) showed conversion of telomerase activity from negative to positive after recurrence. Telomerase activity was changed to negative in 4 out of 6 (66%) recurred patients with positive telomerase activity after second surgery. CONCLUSION The telomerase activity in peripheral whole blood extracts of HNSCC patients might be a useful biomarker for detecting recurrence after treatment. Further study with larger sample size using a more sensitive detection method of telomerase activity is necessary to verify these results.

Endoscopic submucosal resection of esophageal subepithelial lesions using band ligation

Subepithelial lesions (SELs) are occasionally found in the esophagus during upper endoscopy. Sometimes endoscopic resection is needed for accurate diagnosis or in the rare cases of malignant transformation of SELs. In this case series, we evaluated the usefulness of endoscopic submucosal resection with a ligation device (ESMR-L) in esophageal SELs. Twenty-three patients with 25 esophageal SELs that were no larger than 13 mm and were localized within the muscularis mucosae or submucosa were enrolled. ESMR-L was successfully performed in all 25 SELs. The en bloc resection rate was 100% (25/25), and histologically complete resection was achieved in 24 lesions (24/25, 96%). After resection of the lesion by snare, minor immediate bleeding occurred in four cases, but there was no delayed bleeding or perforation.

Proliferation of pancreatic endocrine cells using disaggregation-expansion-reaggregation technology in isolated rat islets

Donor scarcity is a major obstacle for clinical islet transplantation. Hence, the effective use of the limited number of available islets is necessary for successful islet transplantation. We have developed a new technology that could produce pseudo-islets. Morphologic and functional evaluation was performed to test the feasibility of using these cells for transplantation. A 3-step procedure known as disaggregation-expansion-reaggregation (DER) was employed for pseudo-islet preparation. Islets isolated from 200 to 250-g male Lewis rats by collagenase digestion were separated into single cells by trypsinization. These pancreatic endocrine cells (PECs) were expanded by serial passages in culture before being aggregated at a high cell-density in a suspended state. After DER, cells were morphologically analyzed over time, and gene expression evaluated by reverse transcriptase polymerase chain reaction (RT-PCR). Through expansion by passage for 2 weeks in continuous cultures, approximately 1 million PECs were recovered after aggregation. By phase-contrast microscopy, they presented with spherical shapes and similar sizes compared with naïve islets (50-800 microm). RT-PCR results indicated expression of insulin, glucagon, and pancreatic and duodenal homeobox gene 1, which were observed in primary isolated islets as well. The insulin secretion capacity of pseudo-islets was confirmed by enzyme-linked immunosorbent assay. In conclusion, PECs treated with DER showed potential to serve as a cell source for pseudo-islet generation after in vitro cellular expansion. These cells were both morphologically and genetically similar to naïve islets. Our new technique could be a potential method to overcome the scarcity of donor islets in the near future.

Nanopattern insert molding

A new method was investigated to produce nanopatterns on polymeric surfaces with high resolution, good productivity, and low cost. It has certain advantages when compared with such conventional techniques as nanoimprint lithography (NIL), hot embossing, and injection molding. Polyvinyl alcohol (PVA) was utilized for preparation of the stamp with nanopatterns on its surface. The nanoimprinted PVA film was inserted into the cavity and the polymer melt was injected into the mold. Nanopatterns with pillars smaller than 100 nm were produced on the polymeric surface. The water soluble PVA film was used as the inserted template to overcome the difficulties of releasing the nanopatterned film from the substrate.

A new compound, 1H,8H-pyrano[3,4-c]pyran-1,8-dione, suppresses airway epithelial cell inflammatory responses in a murine model of asthma

Clinical and experimental studies have established eosinophilia as a sign of allergic disorders. Activation of eosinophils in the airways is believed to cause epithelial tissue injury, contraction of airway smooth muscle and increased bronchial responsiveness. As part of the search for new antiasthmatic agents produced by medicinal plants, the effects of 270 standardized medicinal plant extracts on cytokine-activated A549 human lung epithelial cells were evaluated. After several rounds of activity-guided screening, the new natural compound, 1H,8H-Pyrano[3,4-c]pyran-1,8-dione (PPY), was isolated from Vitex rotundifolia L. To elucidate the mechanism by which the anti-asthmatic responses of PPY occurred in vitro, lung epithelial cells (A549 cell) were stimulated with TNF-alpha, IL-4 and IL-1beta to induce the expression of chemokines and adhesion molecules involved in eosinophil chemotaxis. PPY treatments reduced the expression of eotaxin, IL-8, IL-16 and VCAM-1 mRNA significantly. Additionally, PPY reduced eotaxin secretion in a dose-dependent manner and significantly inhibited eosinophil migration toward A549 medium. In addition, PPY treatment suppressed the phosphorylation of p65 and ERK1/2, suggesting that it can inhibit the MAPK/NF-KB pathway. To clarify the anti-inflammatory and antiasthmatic effects of PPY in vivo, we examined the influence of PPY on the development of pulmonary eosinophilic inflammation in a murine model of asthma. To accomplish this, mice were sensitized and challenged with ovalbumin (OVA) and then examined for the following typical asthmatic reactions: an increase in the number of eosinophils in BALF; the presence of Th2 cytokines such as IL-4 and IL-5 in the BALF; the presence of allergen-specific IgE in the serum; and a marked influx of inflammatory cells into the lung. Taken together, our results revealed that PPY exerts profound inhibitory effects on the accumulation of eosinophils into the airways while reducing the levels of IL-4, IL-5, and IL-13 in the BALF. Therefore, these results suggest that PPY may be useful as a new therapeutic drug for the treatment of allergic asthma.

Detection of diverse SCCmec variants in methicillin-resistant Staphylococcus aureus and comparison of SCCmec typing methods

Non-duplicate methicillin-resistant Staphylococcus aureus (MRSA) isolates (n = 436), collected from four hospitals located in three Korean cities between 2001 and 2005, were investigated by SCCmec typing and multilocus sequence typing (MLST). Variations within SCCmec, especially type II, were detected in 165 (37.8%) isolates, and these variants were characterised using four different SCCmec typing methods. The predominant SCCmec type was a type II variant that differed from type II by the absence of a pUB110 insertion. MLST analysis showed that most of the isolates carrying SCCmec variants belonged to ST5.

Dual enteric and respiratory tropisms of winter dysentery bovine coronavirus in calves

Although winter dysentery (WD), which is caused by the bovine coronavirus (BCoV) is characterized by the sudden onset of diarrhea in many adult cattle in a herd, the pathogenesis of the WD-BCoV is not completely understood. In this study, colostrum-deprived calves were experimentally infected with a Korean WD-BCoV strain and examined for viremia, enteric and nasal virus shedding as well as for viral antigen expression and virus-associated lesions in the small and large intestines and the upper and lower respiratory tract from 1 to 8 days after an oral infection. The WD-BCoV-inoculated calves showed gradual villous atrophy in the small intestine and a gradual increase in the crypt depth of the large intestine. The WD-BCoV-infected animals showed epithelial damage in nasal turbinates, trachea and lungs, and interstitial pneumonia. The WD-BCoV antigen was detected in the epithelium of the small and large intestines, nasal turbinates, trachea and lungs. WD-BCoV RNA was detected in the serum from post-inoculation day 3. These results show that the WD-BCoV has dual tropism and induces pathological changes in both the digestive and respiratory tracts of calves. To our knowledge, this is the first detailed report of dual enteric and respiratory tropisms of WD-BCoV in calves. Comprehensive studies of the dual tissue pathogenesis of the BCoV might contribute to an increased understanding of similar pneumoenteric CoV infections in humans.

Fabrication of fluorine-doped diamond-like carbon stamps for UV nanoimprint lithography

Two fluorine-doped diamond-like carbon (F-DLC) stamps with sub-100 nm line patterns were fabricated using a direct etching method. These were applied successfully to ultraviolet (UV) nanoimprint lithography without requiring an anti-adhesion layer coating. Tests were performed to determine the optimum fluorine concentration for the F-DLC stamps. The ideal stamp material consisted of 25 at.% F-DLC with a contact angle of 85°, UV transmittance of 16.4-26.8%, and hardness of 4.5 GPa. The O(2) plasma etch rate of the DLC was increased considerably by the fluorine doping, making it comparable to the etch rate of polymethyl methacrylate (PMMA). Thus, only PMMA was used as the etch mask in the fabrication of the stamps.

Anatomical correlates of early mutism in progressive nonfluent aphasia

Patients with progressive nonfluent aphasia (PNFA) can become mute early in the course of the disease. Voxel-based morphometry showed that PNFA is associated with left anterior insula and inferior frontal atrophy. In PNFA with early mutism, volume loss was more prominent in the pars opercularis and extended into the left basal ganglia. Damage to the network of brain regions involved in both coordination and execution of speech causes mutism in PNFA.

The effects of apigenin-7-O-beta-D-glucuronopyranoside on reflux oesophagitis and gastritis in rats

1. This study evaluated the inhibitory action of apigenin-7-O-beta-D-glucuronopyranoside (AGC), apigenin, and omeprazole on reflux oesophagitis and gastritis in rats. AGC was isolated from Clerodendron trichotomum leaves. 2. Oesophagitis and gastritis were induced by surgical procedure and the administration of indomethacin, respectively. The intraduodenal (i.d.) administration of AGC decreased the volume of gastric juice and increased the gastric pH compared with apigenin and omeprazole. The acid output was more inhibited by AGC in a dose-dependent manner than by apigenin and omeprazole. Compared with apigenin and omeprazole, AGC significantly decreased the size of gastric lesions, which were induced by exposure of the gastric mucosa to indomethacin. 3. Malondialdehyde (MDA) content, which is the end product of lipid peroxidation, was increased significantly after the induction of reflux oesophagitis. The MDA content was decreased by AGC (i.d. 3 mg kg(-1)), but not by either apigenin or omeprazole. This suggests that AGC has an antioxidative effect. In the oesophagitis group, the mucosal levels of glutathione (GSH) were significantly lower than that in the normal group. However, the GSH levels were preserved after administering the AGC, suggesting that AGC possesses scavenging activity. 4. In summary, AGC is more potent than apigenin and omeprazole at inhibiting reflux oesophagitis and gastritis and may therefore be a promising drug for their treatment.

Effect of leptin on insulin resistance of muscle – direct or indirect?

We examined the effect of leptin on the insulin resistance in skeletal muscles by measuring glucose transport. Male Wistar rats were fed rat chow or high-fat diets for 30 days. Before sacrifice, rats fed high-fat diet were subcutaneously injected with leptin (1 mg/kg b.w.) for 3 days. The glucose transport in epitrochlearis and soleus muscles did not differ in the experimental groups under basal conditions, however these values decreased significantly in the rats fed high-fat diet under insulin stimulation (p<0.01). Leptin treatment recovered the decreased glucose transport in epitrochlearis (p<0.05) and soleus muscles (p=0.08). Triglyceride concentrations in soleus muscles were increased significantly in the rats fed high-fat diet as compared to rats fed chow diet (p<0.01), and were decreased significantly by leptin treatment (p<0.01). The glucose transport was measured under basal conditions and after 60 microU/ml of insulin treatment with or without 50 ng/ml of leptin. Leptin had no direct stimulatory effect on glucose transport under both basal and insulin-stimulated conditions in vitro. These results demonstrate that leptin injection to rats fed high-fat diet recovered impaired insulin responsiveness of skeletal muscles and muscle triglyceride concentrations. However, there was no direct stimulatory effect of leptin on insulin sensitivity of skeletal muscles in vitro.

Production of eleutherosides in in vitro regenerated embryos and plantlets of Eleutherococcus chiisanensis

High frequency somatic embryogenesis of Eleutheorcoccus chiisanensis was achieved through suspension culture of embryogenic cells in hormone-free Murashige and Skoog liquid medium supplemented with 30 g sucrose l-1. Cotyledonary somatic embryos were germinated and converted into plantlets using 20 microM: gibberellic acid which were then grown in a 10 l airlift bioreactor. HPLC analysis revealed the accumulation of eleutheroside B, E and E1 in the embryos and plantlets. Thus mass production of embryos and plantlets of E. chiisanensis can be achieved in liquid cultures and the biomass produced may become an alternative source of eleutherosides.

Mechanism of histone deacetylase inhibitor Trichostatin A induced apoptosis in human osteosarcoma cells

Although histone deacetylase (HDAC) inhibitors are emerging as a promising new treatment strategy in malignancy, how they exert their effect on osteosarcoama cells is as yet unclear. This study was undertaken to investigate the underlying mechanism of a HDAC inhibitor Trichostatin A (TSA)-induced apoptosis in a osteosarcoma cell line HOS. We observed that TSA treatment decreased the viability of the cells and prominently increased acetylation of histone H3. Evidence was obtained indicating that TSA induced apoptosis of HOS cells as follows: (1) Generation of DNA fragmentation; (2) activation of procaspase-3; (3) cleavage of PARP; and (4) increase of DNA hypoploidy. The reduction of MMP and the release of cytochrome c to cytosol were also shown, indicating that TSA induces apoptosis in HOS cells in a histone acetylation- and mitochondria-dependent fashions. We also examined whether TSA can sensitize HOS cells to the action of an antitumor agent genistein. The combination therapy of TSA and genistein showed synergistic anticancer effect indicating that TSA can be considered as a novel therapeutic strategy for osteosarcoma not only from its direct apoptosis-inducing activity but also from the possibility of sensitization to other antitumor agents.

Influence of exposure to electromagnetic field on the cardiovascular system

1 We examined whether extremely low frequency electromagnetic fields (ELF-EMF) affect the basal level of cardiovascular parameters and influence of drugs acting on the sympathetic nervous system. 2 Male rats were exposed to sham control and EMF (60 Hz, 20 G) for 1 (MF-1) or 5 days (MF-5). We evaluated the alterations of blood pressure (BP), pulse pressure (PP), heart rate (HR), and the PR interval, QRS interval and QT interval on the electrocardiogram and dysrhythmic ratio in basal level and dysrhythmia induced by beta-adrenoceptor agonists. 3 In terms of the basal levels, there were no statistically significant differences among control, MF-1 and MF-5 in PR interval, QRS interval, mean BP, HR and PP. However, the QT interval, representing ventricular repolarization, was significantly reduced by MF-1 (P < 0.05). 4 (-)-Dobutamine (beta1-adrenoceptor-selective agonist)-induced tachycardia was significantly suppressed by ELF-EMF exposure in MF-1 for the increase in HR (DeltaHR), the decrease in QRS interval (DeltaQRS) and the decrease in QT (DeltaQT) interval. Adrenaline (nonselective beta-receptor agonist)-induced dysrhythmia was also significantly suppressed by ELF-EMF in MF-1 for the number of missing beats, the dysrhythmic ratio, and the increase in BP and PP. 5 These results indicated that 1-day exposure to ELF-EMF (60 Hz, 20 G) could suppress the increase in HR by affecting ventricular repolarization and may have a down-regulatory effect on responses of the cardiovascular system induced by sympathetic agonists.

Differential regulation by Ca(2+) of calmodulin- and PKC-dependent contractile pathways in cat lower oesophageal sphincter

1. In the present investigation we examined the regulation of calmodulin (CaM)- and protein kinase C (PKC)-dependent pathways by cytosolic Ca(2+) in the contraction of cat lower oesophageal sphincter (LES). 2. Force developed in response to increasing doses of acetylcholine (ACh) was directly related to the increase of the [Ca(2+)](i) measured by fura-2. Thapsigargin, which depletes Ca(2+) stores, reduced the contraction and the [Ca(2+)](i). In addition, contraction in response to maximal ACh was reduced by the CaM inhibitor CGS9343B but not by the PKC inhibitor chelerythrine. The contraction in response to submaximal ACh was reduced by chelerythrine but not by CGS9343B. 3. In permeabilized cells, the contraction in response to low Ca(2+) (0.54 microm) was also reduced by CGS9343B. 4. The response to high Ca(2+) (1.0 microm) was reduced by CGS9343B. ACh also inhibited PKC activation induced by diacylglycerol, which activation is inhibited by the N-myristoylated peptide inhibitor derived from pseudosubstrate sequences of PKCalphabetagamma (myr-PKC-alphabetagamma), but not of myr-PKC-alpha. 5. These data are consistent with the view that activated CaM-dependent pathways inhibit PKC-dependent pathways, this switch mechanism might be regulated by Ca(2+) in the LES.

Enhanced post-germinative growth of encapsulated somatic embryos of Siberian ginseng by carbohydrate addition to the encapsulation matrix

This experiment was carried out to enhance conversion and ex vitro survival of encapsulated somatic embryos of Siberian ginseng (Eleutherococcus senticosus). Cotyledonary somatic embryos were encapsulated with 3.0% sodium alginate; 96% of the encapsulated embryos converted to plantlets with well-elongated epicotyls in Perlite containing sucrose as a carbon source. However, although they germinated, post-germinative growth of encapsulated embryos was suppressed on Perlite that did not contain sucrose. Instead of sucrose addition to Perlite, addition of carbon sources to the encapsulation matrix enhanced post-germinative growth of encapsulated embryos. In the encapsulation matrix with 2% sucrose, post-germinative growth of encapsulated embryos was more than twice (23.5%) that of the control capsules without sucrose (10.0%). Embryos encapsulated with both 2% sucrose and 1% starch powder showed the highest post-germinative growth percentage (42.1%). Iodine staining and analysis of starch content in the encapsulation matrix revealed that starch in the encapsulation matrix decomposed during embryo germination. This result indicates that carbohydrate treatment in the encapsulation matrix enhanced post-germinative growth of encapsulated embryos of Siberian ginseng.

Agrobacterium rhizogenes-mediated transformation of Taraxacum platycarpum and changes of morphological characters

Transformed hairy roots were efficiently induced from seedlings of Taraxacum platycarpum by infection with Agrobacterium rhizogenes 15834. Root explants produced transformed roots at a higher frequency (76.5+/-3.5%) as compared to stem (32.7+/-4.8%) or cotyledon (16.2+/-5.7%). Hairy roots exhibited active elongation with high branching of roots on growth regulator-free medium. The competence of plant regeneration from non-transformed adventitious roots and transformed hairy roots was compared. The frequency of adventitious shoot formation from transformed roots was much higher (88.5+/-9.8%) than that of non-transformed roots (31.7 +/-9.5%) on hormone-free medium. Rooting of hairy root-derived adventitious shoots occurred easily on growth regulator-free medium but no rooting was observed on non-transformed shoots. The stable introduction of rol genes into Taraxacum plants was confirmed by PCR and Southern hybridization. Transgenic plantlets showed considerable differences in their morphology when compared to the corresponding wild-type (non-transgenic) plants. Plantlets formed from transformed roots had numerous fibrous roots with abundant lateral branches instead of the thickened taproots in non-transformed plants. The differences observed may reflect the modification of morphological root characters by introduction of rol genes.

Agrobacterium-mediated transformation of niger [ Guizotia abyssinica (L. f.) Cass.] using seedling explants

A protocol was developed for Agrobacterium-mediated genetic transformation of niger [ Guizotia abyssinica (L.f.) Cass.] using hypocotyl and cotyledon explants. Hypocotyls and cotyledons obtained from 7-day-old seedlings were co-cultivated with Agrobacterium tumefaciens strain EHA101/pIG121Hm that harbored genes for beta-glucuronidase (GUS), kanamycin, and hygromycin resistance. Following co-cultivation, the hypocotyl and cotyledon explants were cultivated on MS medium containing 1 mg/l 6-benzylaminopurine (BA) for 3 days in darkness. Subsequently, hypocotyl and cotyledon explants were transferred to selective MS medium containing 1 mg/l BA, 10 mg/l hygromycin, 10 mg/l kanamycin, and 500 mg/l cefotaxime. After 6 weeks, hypocotyls and cotyledons produced multiple adventitious shoot buds, and these explants were subcultured to MS medium containing 1 mg/l BA, 30 mg/l hygromycin, and 30 mg/l kanamycin. After a further 3 weeks, the explants (along with developing shoot buds) were subcultured to MS medium containing 1 mg/l BA, 50 mg/l kanamycin, and 50 mg/l hygromycin for further selection. Transgenic plants were obtained after rooting on half-strength MS medium supplemented with 0.1 mg/l alpha-naphthaleneacetic acid, 50 mg/l kanamycin, and 50 mg/l hygromycin and were confirmed by GUS histochemical assay and polymerase chain reaction analysis. Genomic Southern blot hybridization confirmed the incorporation of the neomycin phosphotransferase II gene into the host genome.