Protein release microparticles based on the blend of poly(D,L-lactic-co-glycolic acid) and oligo-ethylene glycol grafted poly(L-lactide)

Bovine serum albumin (BSA), a model protein drug, was encapsulated with a microparticle based on the blend of poly(D,L-lactic-co-glycolic acid) (PLGA) and poly(L-lactide)-g-oligo(ethylene glycol) (PLLA-g-oligoEG). Effects of PLLA-g-oligoEG in the blend on degradation, characteristic properties, and release behavior of the microparticle were studied. Drug loading efficiency increased with increase in the graft frequency of oligoEG in the graft copolymer in the blend. The release of BSA was found to be more efficient for microparticles based on the blend than on the PLGA, which is due to the faster protein diffusion through the swollen phase of the hydrogel-like structure. The microparticles based on the blend showed a slower degradation and a lower pH shift compared to that of PLGA.

Ca2+-dependent membrane currents in vascular smooth muscle cells of the rabbit

The membrane potential in vascular smooth muscle cells contributes to the regulation of cytosolic [Ca2+], which in turn regulates membrane potential by means of Ca2+i-dependent ionic currents. We investigated the characteristics of Ca2+i-dependent currents in rabbit coronary and pulmonary arterial smooth muscle cells. Ca2+i-dependent currents were recorded using the whole-cell patch-clamp technique while cytosolic [Ca2+] was increased by caffeine. The reversal potentials of caffeine-induced currents were between -80 and -10 mV under normal ionic conditions, whereas they were about 0 mV when K+-free NaCl solutions were used both in pipette and bath. The total substitution of extracellular Na+ with membrane-impermeable cation N-Methyl-D-glucamine did not affect caffeine-induced currents, implying no significant contribution of Na+ as a permeant ion to the currents. The substitution of extracellular NaCl with sucrose reduced outward component of the currents and shifted the reversal potentials according to the change in Cl- equilibrium potential. Upon application of the niflumic acid under K+-free conditions, most of the current induced by caffeine was inhibited. Taken together, the results of the present study indicate that K+ and Cl- currents are major components of Ca2+i-dependent currents in vascular smooth muscles isolated from coronary and pulmonary arteries of the rabbit, and the relative contribution of each type of current to total currents are not different between the two arteries.

Is body mass index the prognostic factor in breast cancer?: a meta-analysis

This study was performed to integrate the results of previous studies that investigated the relationship between body mass index (BMI) and prognosis in breast cancer. We reviewed the English literatures using the MEDLINE database from 1966 to 1999. The materials included 12 published articles with a total of 8,029 cases of breast cancer. The effect size was obtained from hazard ratio in each study. Homogeneity test was conducted before the integration of each effect size and the result demonstrated that the studies were heterogeneous. A random effect model was used to integrate the overall effect size. The integrated effect size was 1.56 (95% confidence interval, 1.22-2.00). In addition, publication bias should be accounted for because each published study was asymmetric in shape revealed by funnel plot. These results suggest that BMI have a prognostic significance in breast cancer. We believe that well-designed longitudinal studies, involving a large number of samples are required to resolve these issues.

Characterization of mutations, including a novel regulatory defect in the first intron, in Bruton's tyrosine kinase gene from seven Korean X-linked agammaglobulinemia families

In this report, we describe seven mutations, including a novel single base pair substitution in intron 1, of the Bruton's tyrosine kinase (Btk) gene found in 12 Korean patients with X-linked agammaglobulinemia. Various mutations, including three novel genetic alterations, were discovered using single-strand conformation polymorphism analysis and direct DNA sequencing. The effect of the intron 1 point mutation (intron 1 +5G-->A) was further evaluated using reporter constructs. Using luciferase assay experiments, we showed that the transcriptional activity of the mutant was significantly lower than in normal counterparts, indicating that the intronic mutation was functional. In addition, DNase I footprinting analysis showed that a single protected region spanning the position +3 to +15 bp hybridized with a mutant-specific probe, but not with a wild-type probe. EMSA indicated that a distinct nuclear protein has the ability to bind the mutant oligonucleotides to produce a new DNA-protein complex. We also observed decreased expression of Btk proteins in monocytes of patients having the point mutation in intron 1. Taken together with the functional analysis, our results strongly suggest the existence of a novel cis-acting element, which might be involved in the down-regulation of Btk gene transcription. Precise definition of the regulatory defect in the Btk intron 1 may provide valuable clues toward elucidating the pathogenesis of X-linked agammaglobulinemia.

Pharyngo-enteral anastomosis for esophageal reconstruction in diffuse corrosive esophageal stricture

BACKGROUND

Diseases involving the entire esophagus usually require extensive surgical procedures to accomplish functional reconstruction. These procedures are extremely stressful for undernourished patients. We have utilized a simpler procedure for total esophageal reconstruction.

METHODS

This retrospective report reviews the experience in 8 patients who underwent esophageal reconstruction by pharyngo-colo-gastrostomy or jejunostomy without any resection of bony structures.

RESULTS

There was no operative or hospital death. Complications included anastomotic stenosis, transient leak from the ileal stump, and late enterocutaneous fistula, each in 1 patient. Laryngeal function was maintained without special treatments. After swallowing training for approximately 1 week, oral feeding was resumed. All patients have gained 7 to 21 kg at 35 to 67 months after surgery.

CONCLUSIONS

Our surgical procedure is shown to be safe and effective in undernourished patients with diffuse esophageal stricture.

Epidemiologic and clinical survey of Behcet's disease in Korea: the first multicenter study

The prevalence of Behcet's disease is the highest in the East Asian and the Mediterranean countries. Behcet's disease is also distributed in the Asian countries, but the nationwide survey has not been performed in Korea yet. The Korean Study Group for Behcet's Disease, founded in 1999, conducted a multicenter, retrospective survey on epidemiologic and clinical features of the patients with Behcet's disease from 20 hospitals around the nation from 1997 to 1999. Of 3,497 patients, 1,527 were classified into complete or incomplete type of Behcet's disease according to the revised Shimizu's classification. The sex ratio was 1:1.75 with the female predominance. Geographical distribution showed the highest frequency in Seoul (38.5%). Clinically, 98.8% had oral ulcers, 83.2% had genital ulcers, 84.3% had skin lesions and 50.9% had ocular lesions. As for the minor clinical manifestations, articular symptoms were the most frequent. The pathergy test showed positive in 15.4% of patients and revealed a higher positive rate in males (20.2%) than in females (12.7%). In conclusion, we performed the first multicenter study on Behcet's disease in Korea and revealed the female predominance, higher frequency of ocular lesions, and lower positivity of pathergy test in the patients.

Oligodendrocyte lineage genes (OLIG) as molecular markers for human glial brain tumors

The most common primary tumors of the human brain are thought to be of glial cell origin. However, glial cell neoplasms cannot be fully classified by cellular morphology or with conventional markers for astrocytes, oligodendrocytes, or their progenitors. Recent insights into central nervous system tumorigenesis suggest that novel molecular markers might be found among factors that have roles in glial development. Oligodendrocyte lineage genes (Olig1/2) encode basic helix-loop-helix transcription factors. In the rodent central nervous system, they are expressed exclusively in oligodendrocytes and oligodendrocyte progenitors, and Olig1 can promote formation of an chondroitin sulfate proteoglycon-positive glial progenitor. Here we show that human OLIG genes are expressed strongly in oligodendroglioma, contrasting absent or low expression in astrocytoma. Our data provide evidence that neoplastic cells of oligodendroglioma resemble oligodendrocytes or their progenitor cells and may derive from cells of this lineage. They further suggest the diagnostic potential of OLIG markers to augment identification of oligodendroglial tumors.

Tissue-engineered heart valve leaflets: an animal study

BACKGROUND

Tissue-engineered heart valve leaflets are a promising way to overcome the inherent limitations of current prosthetic valves. The aim of this study was to compare the biological responses of an autologous cell seeded scaffold and an acellular scaffold implanted in the pulmonary valve leaflet in the same animal.

METHODS

Myofibroblasts and endothelial cells were isolated and cultured from an ovine artery. A synthetic biodegradable scaffold consisting of polyglycolic acid and polylactic acid was initially seeded with the myofibroblasts, then coated with endothelial cells. Cells were seeded using a medium containing collagen and cultured. A tissue-engineered construct and a plain scaffold were implanted as double pulmonary valve leaflet replacement in the same animal in an ovine model (n=3). Additionally, the tissue-engineered construct (n=2) and the plain scaffold (n=2) were implanted as single valve leaflet replacements for long-term analysis. After sacrifice, the implanted valve leaflet tissues were retrieved, analyzed visually and using light microscopy.

RESULTS

Three animals that underwent replacement of two valve leaflets with a tissue-engineered construct and a plain scaffold, survived only a short-time (12, 24, 36 hours). The death was attributed to heart failure caused by severe pulmonary insufficiency. Animals that underwent single valve leaflet replacement survived longer and were electively sacrificed at 6 and 9 weeks after operation. The analysis of the leaflets from the short-term survivors showed that the tissue-engineered constructs contained less fibrins and protein exudates than the plain scaffold. In contrast, leaflets obtained from animals surviving 6 and 9 weeks showed similar well organized granulation tissues in the tissue-engineered constructs and the plain scaffolds.

CONCLUSION

This animal experiment demonstrates that in the early phase of implantation, the tissue-engineered construct shows a better biological response in terms of antithrombogenicity than the plain scaffold, although both of them have similar results in the later reparative phase.

Prolonged cold preservation augments vascular injury independent of renal transplant immunogenicity and function

BACKGROUND

While prolonged cold ischemia has detrimental effects on graft survival, the mechanisms remain unclear. We tested whether or not cold preservation enhances intragraft inflammatory responses and vascular injury.

METHODS

Rat renal grafts were cold preserved in University of Wisconsin solution for 2, 4, 6, 12, 24, and 48 hours, and then transplanted into syngeneic recipients and harvested after 24 hours. Frozen sections were examined histologically and stained for vascular cellular adhesion molecule-1 (VCAM-1), platelet-endothelial cell adhesion molecule-1 (PECAM-1), major histocompatibility complex (MHC) class II, tissue factor, leukocyte function associated molecule-1 (LFA-1), very late antigen-4 (VLA-4), as well as for inflammatory cells.

RESULTS

Function did not differ between isografts preserved for shorter (2 to 6 hours) or longer times (12 to 24 hours). Neutrophil influx and that of LFA-1-positive cells showed similar increases in all groups. Compared with short preservation groups, the long preserved grafts had more VLA-4-positive ED-1+ monocytic infiltrates adjacent to vessels expressing VCAM-1 (P < or = 0.001). Increased preservation duration had no effect on infiltration with recipient ED-2+ macrophages, MHC class II-positive cells, or dendritic cells. Decreased color intensity and continuity of PECAM-1 staining indicated loss of endothelial integrity in grafts preserved for longer than six hours. Intensity in VCAM-1 staining increased progressively in grafts preserved for more than six hours and was localized predominantly on the endothelium of elastic vessels. Endothelial cells, vascular smooth muscle cells, and monocytes expressed increasingly more tissue factor in grafts preserved for more than six hours, revealing enhanced intragraft procoagulant capacity. Furthermore, grafts with preservation times of more than six hours developed more severe vascular endothelial injury and worse tubular necrosis scores (P < or = 0.001) compared with grafts with shorter preservation times.

CONCLUSIONS

Because of the prominent vascular injury, strategies for endothelial protection should be attempted in grafts with long preservation times in clinical renal transplantation.

Effects of covariance model assumptions on hypothesis tests for repeated measurements: analysis of ovarian hormone data and pituitary-pteryomaxillary distance data

In the analysis of repeated measurements, multivariate methods which account for the correlations among the observations from the same experimental unit are widely used. Two commonly-used multivariate methods are the unstructured multivariate approach and the mixed model approach. The unstructured multivariate approach uses MANOVA types of models and does not require assumptions on the covariance structure. The mixed model approach uses multivariate linear models with random effects and requires covariance structure assumptions. In this paper, we describe the characteristics of tests based on these two methods of analysis and investigate the performance of these tests. We focus particularly on tests for group effects and parallelism of response profiles.

Amelioration of angiotensin II-induced cardiac injury by a 3-hydroxy-3-methylglutaryl coenzyme a reductase inhibitor

BACKGROUND

3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) have effects that extend beyond cholesterol reduction. We used an angiotensin (Ang) II-dependent model to test the hypothesis that cerivastatin ameliorates cardiac injury.

METHODS AND RESULTS

We treated rats transgenic for human renin and angiotensinogen (dTGR) chronically from weeks 4 to 7 with cerivastatin (0.5 mg/kg by gavage). We used immunohistochemistry, electrophoretic mobility shift assays, and reverse transcription-polymerase chain reaction techniques. Compared with control dTGR, dTGR treated with cerivastatin had reduced mortality, blood pressure, cardiac hypertrophy, macrophage infiltration, and collagen I, laminin, and fibronectin deposition. Basic fibroblast growth factor mRNA and protein expression were markedly reduced, as was interleukin-6 expression. The transcription factors NF-kappaB and AP-1 were substantially less activated, although plasma cholesterol was not decreased.

CONCLUSIONS

These results suggest that statins ameliorate Ang II-induced hypertension, cardiac hypertrophy, fibrosis, and remodeling independently of cholesterol reduction. Although the clinical significance remains uncertain, the results suggest that statins interfere with Ang II-induced signaling and transcription factor activation, thereby ameliorating end-organ damage.

Development of the stress response inventory and its application in clinical practice

OBJECTIVE

The purpose of this study was to develop the Stress Response Inventory (SRI), which includes emotional, somatic, cognitive, and behavioral stress responses, and then to use the scale in clinical practice.

METHODS

First, a preliminary survey was conducted using 109 healthy adults to obtain 75 response items. Second, the preliminary questionnaire was completed by 215 healthy subjects. Third, stress responses were compared among 242 patients (71 with anxiety disorder, 73 with depressive disorder, 47 with somatoform disorder, and 51 with psychosomatic disorder) and the 215 healthy subjects.

RESULTS

Factor analysis yielded seven subscales: tension, aggression, somatization, anger, depression, fatigue, and frustration. Reliability was computed by administering the SRI to 62 healthy subjects during a two-week interval. Test-retest reliability for the seven subscale scores and the total score was high, ranging between 0.69 and 0.96. Internal consistency was computed, and Cronbach's alpha for the seven subscales ranged between 0.76-0.91 and 0.97 for the total score. Convergent validity was computed by correlating the seven subscales and the total score of the SRI with the total score of the Global Assessment of Recent Stress (GARS) scale, the Perceived Stress Questionnaire (PSQ), and the subscale scores of the Symptom Checklist-90-Revised (SCL-90-R). The correlations were all at significant levels. The sensitivity of the SRI was 0.57, specificity 0.74, and the predictive value positive (PVP) was 0.71. The patient group also scored significantly higher on the six subscale scores and the total score than the control group, with the exception being the aggression subscale. The depressive disorder group was highest in total scores on the SRI among the four patient groups, and showed significantly higher total scores than the anxiety disorder and psychosomatic disorder groups. In total scores on the SRI, female subjects scored significantly higher than males.

CONCLUSIONS

These results indicate that the SRI is highly reliable and valid, and that it can be utilized as an effective measure of stress for research in stress-related fields. The depressive disorder group showed more prominent stress responses than the anxiety and psychosomatic disorder groups.

Presumptive mechanisms of peptic ulceration by Helicobacter pylori VacA involving mucoprotease and CagA

Helicobacter pylori vacuolating toxin (VacA) appears to be unusually stable, not only against extreme pH conditions or high temperatures, but also against common organic solvents or detergents. Under acidic conditions, its activity was markedly increased in the manner of temperature-independent, suggesting a spontaneous activation. A similar finding was also observed under alkaline conditions, however, it should have an appropriate temperature. From these observations, the mechanisms of VacA activation were suggested to be so redundant that either the case of acidic or basic amino acid residues could be involved in the VacA activation. Separately, we also found that the VacA production by H. pylori was pH-dependent: Its production was increased at a low pH region with a broad range (1.0-5.0), and at a high pH region with a narrow range (8.0-9.0). Astonishingly, a highly immunogenic CagA did not appear to be expressed under the acidic conditions. Its expression, however, was shown to be enhanced when the surrounding pH of this bacterium was raised. In contrast, mucoproteolytic activity in the H. pylori membrane was found to be increased at acidic conditions. Considering these observations, together with the stomach and duodenal pH of humans, two presumptive mechanisms of H. pylori VacA-associated ulceration may be deduced; namely, an acid- and an alkali-dependent type, involving mucoprotease and CagA, respectively.

An Outbreak of Typhoid Fever, Xing‐An County, People's Republic of China, 1999: Estimation of the Field Effectiveness of Vi Polysaccharide Typhoid Vaccine

To evaluate the effectiveness of Vi polysaccharide vaccine (Vi vaccine) in preventing typhoid fever, an analysis was done of an outbreak of typhoid fever among students attending a middle school in the People's Republic of China, where Vi vaccine is licensed for use. Vi vaccine effectiveness was analyzed by using Cox proportional hazards modeling to account for the time-dependent nature of vaccination and illness status during the outbreak. Among 1260 students who had been immunized before the outbreak, receipt of Vi vaccine was associated with 73% (95% confidence interval [CI], 32%-89%) protection. Among the additional 441 students immunized during the outbreak, receipt of Vi vaccine was associated with 71% (95% CI, -9% to 92%) protection. These results provide the first evidence about the effectiveness of Vi vaccine when deployed routinely in a typhoid-endemic area and support the use of Vi vaccine as a public health tool to control typhoid fever.

p53, BCL-2, and Ki-67 expression according to tumor response after concurrent chemoradiotherapy for advanced rectal cancer

BACKGROUND

Concurrent chemoradiotherapy (CCRT) for locally advanced rectal cancer is an important modality for curative resection, but tumors show wide spectrum response. The purpose of this study was to investigate any correlation among related genetic mutations, proliferative index, and tumor response after CCRT.

METHODS

This study included 23 patients with rectal cancer, who were preoperatively staged as at least T3 N1 or T4 (determined by transrectal ultrasonography and MRI). Enrolled patients were given 5-FU 450 mg/m2/day and leucovorin 20 mg/m2/day intravenously for 5 days during weeks 1 and 5 of radiotherapy (45-54 Gy). Surgical resection was performed 4 weeks after completion of the scheduled treatment. Tumor response was classified as CR (complete response), PR (partial response: 50% diminution of tumor volume and downstaging), and NR (no response). Paraffin-embedded tissue obtained before chemoradiotherapy was studied by immunohistochemical staining for p53, BCL-2, and Ki-67. The extent of tumor response was correlated with proliferative activity and was measured by immunostaining Ki-67 proliferative antigen and the expression of p53 and BCL-2 oncoproteins.

RESULTS

All patients were resectable. CR was obtained in 4 patients, PR in 10 patients, and NR in 9 patients. The p53 mutation was noted in 16 patients: NR in 5 patients, PR in 9 patients, and CR in 2 patients (P = .638). BCL-2 expression was noted in 11 patients: NR in 4 patients, PR in 3 patients, and CR in 4 patients (P = .799). The Ki-67 labeling index was NR: 615.4+/-47.2; PR: 663.2+/-20.4; and CR: 765.5+/-58.3 (CR + PR vs. NR, P = .029).

CONCLUSIONS

Immunohistochemical expression of p53 and BCL-2 does not correlate with tumor response after CCRT, but Ki-67 labeling may be a useful parameter for radiosensitive tumors selected for CCRT.

Modulating angiotensin II-induced inflammation by HMG Co-A reductase inhibition

Angiotensin (Ang) II is capable of producing inflammatory changes by signals through its AT1 receptor. Reactive oxygen species production, adhesion molecule expression, chemokines, and other mediators are involved. Nuclear factor-kappaB (NK-kappaB) and activator protein 1 (AP-1) are two of the transcription factors activating the responsible genes. We have studied Ang II-independent modulating effects in a double transgenic rat model harboring the human renin and angiotensinogen genes. We have recently focused on the protective effects of HMG-CoA reductase inhibition and review these data here. We found that cerivastatin decreased mortality, lowered blood pressure, preserved renal function, decreased cardiac hypertrophy, and inhibited the entire chain of inflammatory events. Furthermore, NF-kappaB and AP-1 activation was sharply attenuated. We also observed that cerivastatin blocked ERK1/2 phosphorylation in vivo and in vitro. Cerivastatin also inhibited phorbol ester-transmitted events in vascular smooth muscle cells. Because Rho, a member of the Ras protein superfamily is important to Ang II-dependent and -independent vascular smooth muscle signaling events, we suggest that cerivastatin may act by inhibiting the prenylation, membrane anchoring, and subsequent activation of Ras proteins. These data may in part explain cholesterol-independent, HMG-CoA reductase-related, protective effects.

Non-combustible waste vitrification with plasma torch melter

Non-combustible radioactive wastes generated from Nuclear Power Plants (NPPs) are composed of concrete, glass, asbestos, metal, sand, soil, spent filters, etc. The melting tests for concrete, glass, sand, and spent filters were carried out using a 60 kW plasma torch system. The surrogate wastes were prepared for the tests. Non-radioactive Co and Cs were added to the surrogates in order to simulate the radioactive waste. Several kinds of surrogate prepared by their own mixture or by single waste were melted with the plasma torch system to produce glassy waste forms. The characteristics of glassy waste forms were examined for the volume reduction factor (VRF) and the leach rate. The VRFs were estimated through the density measurement of the surrogates and the glassy waste forms, and were turned out to be 1.2-2.4. The EPA (Environmental Protection Agency) Toxicity Characteristic Leaching Procedure (TCLP) was used to determine the leach resistance for As, Ba, Hg, Pb, Cd, Cr, Se, Co, and Cs. The leaching index was calculated using the total content of each element in both the waste forms and the leachant. The TCLP tests resulted in that the leach rates for all elements except Co and Cs were lower than those of the Universal Treatment Standard (UTS) limits. There were no UTS limits for Co and Cs, and their leach rate & index from the experiments were resulted in around 10 times higher than those of other elements.

A biological phosphorus removal potential test for wastewaters

A simple test was proposed to assess whether phosphorus in a wastewater can be removed using a biological phosphorus removal (BPR) process. The test includes the measurement of phosphorus release during 2 hours of the anaerobic stage in a batch reactor containing phosphorus-accumulating organisms (PAOs) and estimation of the effluent phosphorus concentration using biochemical relationships. The BPR potential test developed allowed for the successful evaluation of BPR feasibility for five wastewater samples. The BPR potential test was validated by comparing the test results with the effluent phosphorus concentrations measured in a sequencing batch reactor (SBR). An effluent phosphorus concentration of 1.9 mg P/L predicted for the BPR potential test performed was close to the effluent phosphorus concentration of 1.8 mg P/L obtained from an SBR on the same day. During the anaerobic stage, phosphorus release was significantly affected by the sludge concentration initially, but became insignificant after 2 hours. The initial sludge concentration affected the phosphorus release rate; thus, it is recommended that the BPR potential test be conducted at a target mixed liquor volatile suspended solids concentration. It is also recommended that the BPR potential test be conducted at the site where the PAO-containing sludge is available and the wastewater sample can be delivered at 4 degrees C in less than 24 hours. The PAOs in different sludges had almost identical phosphorus release after 2 hours; however, the characteristics of facultative bacteria in sludges affected the phosphorus release. If the wastewater is prefermented for at least 3 days before the BPR potential test, the amount of phosphorus released by various PAO-containing sludges is expected to be identical.

Gain- and loss-of-function of Rhp51, a Rad51 homolog in fission yeast, reveals dissimilarities in chromosome integrity

Rad51 is crucial not only in homologous recombination and recombinational repair but also in normal cellular growth. To address the role of Rad51 in normal cell growth we investigated morphological changes of cells after overexpression of wild-type and a dominant negative form of Rad51 in fission yeast. Rhp51, a Rad51 homolog in Schizosaccharomyces pombe, has a highly conserved ATP-binding motif. Rhp51 K155A, which has a single substitution in this motif, failed to rescue hypersensitivity of a rhp51 mutant to methyl methanesulfonate (MMS) and UV, whereas it binds normally to Rhp51 and Rad22, a Rad52 homolog. Two distinct cellular phenotypes were observed when Rhp51 or Rhp51 K155A was overexpressed in normal cells. Overexpression of Rhp51 caused lethality in the absence of DNA-damaging agents, with acquisition of a cell cycle mutant phenotype and accumulation of a 1C DNA population. On the other hand, overexpression of Rhp51 K155A led to a delay in G(2) with decondensed nuclei, which resembled the phenotype of rhp51. The latter also exhibited MMS and UV sensitivity, indicating that Rhp51 K155A has a dominant negative effect. These results suggest an association between DNA replication and Rad51 function.

Dicobalt octacarbonyl catalyzed carbonylated cycloaddition of triynes to functionalized tetracycles

[reaction: see text]. We have demonstrated that a dicobalt octacarbonyl catalyzed double [2 + 2 + 1] carbonylative cycloaddition reaction of triyne can be carried out to yield a novel 5.5.5.6 tetracyclic di-enone system.

Nitric oxide synthase isoforms I, III and protein kinase-Ctheta in skeletal muscle fibres of normal and streptozotocin-induced diabetic rats with and without Ginkgo biloba extract treatment

The expression of nitric oxide synthase (NOS) isoforms I, III and protein kinase-Ctheta (PKCtheta) in rat vastus lateralis muscle was demonstrated immunohistochemically and then correlated to the physiological metabolic fibre types: SO (slow-oxidative), FOGI, FOGII (fast-oxidative glycolytic; I more glycolytic, II more oxidative), and FG (fast-glycolytic). NOS expression in muscles from different experimental groups (normal and diabetic rats, with and without Ginkgo biloba extract treatment) was assayed by Western blotting. Generally, NOS I and PKCtheta were co-expressed in fibres with predominantly oxidative metabolism (SO, FOGII). This suggests an interplay of PKCtheta and NOS I in nitric oxide production by oxidative fibres. NOS III was more highly expressed in fibres with predominantly glycolytic metabolism (FOGI, FG). A somewhat lower NOS I immunoreactivity was also found in NOS III positive fibres suggesting that NOS III and NOS I are co-expressed in these fibres. Western blotting revealed that NOS I as well as NOS III expression in the vastus lateralis muscle was down-regulated in diabetes and increased after Ginkgo biloba extract treatment. These effects may be associated with a diminished glucose uptake by myocytes of diabetic musclesand with an improved muscle function after Ginkgo biloba treatment.