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1.
Diabetol Int ; 15(2): 237-243, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38524940

ABSTRACT

Aims: To evaluate and compare the effectiveness of once-daily insulin degludec/liraglutide (IDegLira) to that of once-daily insulin degludec/insulin aspart (IDegAsp) after switching from basal insulin therapy at 6 months by assessing changes in hemoglobin A1c (HbA1c), body weight, and insulin doses in patients with type 2 diabetes (T2D). Materials and methods: A total of 91 patients with T2D with HbA1c levels exceeding 7.0% were included in this study. Adjusted least square mean changes in HbA1c, body weight, and total insulin doses were compared between the IDegLira group and IDegAsp group. Subgroup analyses were performed, stratified by median values of HbA1c (< 8.5 and ≥ 8.5%), obesity (body mass index < 25 and ≥ 25 kg/m2), and basal insulin doses (< 14 and ≥ 14 units) at baseline to assess treatment interaction by subgroup. Results: The IDegLira group showed a greater reduction in HbA1c levels than the IDegAsp group (- 0.17 vs - 0.79%, p = 0.003) with comparable body weight changes. The analyses of adjusted mean changes of total insulin doses showed that the IDegAsp group had a larger increase than the IDegLira group (3.64 vs 1.30 unis, p = 0.016). The effect of IDegLira on HbA1c levels was superior to that of IDegAsp in patients with high HbA1c. There were no inter-group differences in the rate of hypoglycemic episodes. Conclusions: Once-daily IDegLira had greater effects on HbA1c and a lesser increase in insulin doses than IDegAsp when patients are switched from basal insulin therapy. Moreover, the effect on HbA1c was enhanced in patients with high HbA1c levels at baseline.

2.
Chronic Dis Transl Med ; 8(2): 134-144, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35774427

ABSTRACT

Background: This study was to explore the clinical efficacy and safety of darbepoetin alfa injection replacing epoetin alfa injection (recombinant human erythropoietin injection, rHuEPO) for the treatment of anemia associated with chronic kidney failure in Chinese patients undergoing hemodialysis. Method: This study was a multicenter, randomized, open-label, intergroup parallel control phase III noninferiority trial from April 19, 2013 to September 9, 2014 at 25 sites. In this study, the members of the darbepoetin alfa group underwent intravenous administration once per week or once every two weeks. The members of the control drug epoetin alfa group underwent intravenous administration two or three times per week. All subjects underwent epoetin alfa administration during the 8-week baseline period. After that, subjects were randomly assigned to the darbepoetin alfa group or epoetin alfa group. The noninferiority in the changes of the average Hb concentrations from the baseline to the end of the evaluation period (noninferiority threshold: -1.0 g/dl) was tested between the two treatments. The time-dependent hemoglobin (Hb) concentration and the maintenance rate of the target Hb concentration (the proportion of subjects with Hb concentrations between 10.0 and 12.0 g/dl) were also evaluated. Iron metabolism, including changes in the serum iron, total iron-binding capacity, ferritin, transferrin saturation, and comparisons of the dose adjustments between the two groups during the treatment period were analyzed further. Adverse events (AEs) were also observed and compared, and the safety was analyzed between the two treatment groups. The conversion rate switching from epoetin alfa to darbepoetin alfa was also discussed. SAS® software version 9.2 was used to perform all statistical analyses. Descriptive statistics were used for all efficacy, safety, and demographic variable analyses, including for the primary efficacy indicators. Results: Four hundred and sixty-six patients were enrolled in this study, and ultimately 384 cases were analyzed for safety, including 267 cases in the darbepoetin alfa group and 117 cases in the epoetin alfa group. There were 211 cases in the per-protocol set, including 152 cases in the darbepoetin alfa group and 59 cases in the epoetin alfa group. The changes in the average Hb concentrations from the baseline to the end of the evaluation period were -0.07 and -0.15 g/dl in the darbepoetin alfa group and epoetin alfa group respectively. The difference between the two groups was 0.08 g/dl (95% confidence interval [CI]: -0.22 to 0.39), and the lower limit of the 95% CI was -0.22 > -1.0 g/dl. The average Hb concentrations of the two groups were 10.88-11.43 g/dl (darbepoetin alfa) and 10.91-11.38 g/dl (epoetin alfa) during the study period of Weeks 0-28, with the maintenance rates of the target Hb concentration ranging within 71%-87% and 78%-95% in the darbepoetin alfa group and epoetin alfa group respectively. During the period of comparison between the two groups, the incidence of AEs in the darbepoetin alfa group was 61.42%, while in the epoetin alfa group it was 56.41%. All of the adverse events and reactions in the study were those commonly associated with hemodialysis. Conclusion: The overall efficacy and safety of darbepoetin alfa for the treatment of Chinese renal anemia patients undergoing hemodialysis are consistent with those of epoetin alfa.

3.
Chronic Dis Transl Med ; 8(1): 59-70, 2022 Mar.
Article in English | MEDLINE | ID: mdl-35620165

ABSTRACT

Background: Erythropoietin is a glycoprotein that mainly regulates erythropoiesis. In patients with chronic renal failure with anemia, darbepoetin alfa can stimulate erythropoiesis, correct anemia, and maintain hemoglobin levels. This study was designed to demonstrate the efficacy and safety of darbepoetin alfa injections as being not inferior to epoetin alfa injections (Recombinant Human Erythropoietin injection, rHuEPO) when maintaining hemoglobin (Hb) levels within the target range (10.0-12.0 g/dL) for the treatment of renal anemia. Methods: Ninety-five patients were enrolled in this study from April 15, 2013 to April 10, 2014 at 25 sites. In this study, patients (n = 95) aged 18-70 years were randomized into a once per week intravenous darbepoetin alfa group (n = 56) and a twice or three times per week intravenous epoetin alfa group (n = 39) for 28 weeks, who had anemia with hemoglobin levels between 6 g/dL and 10 g/dL due to chronic kidney disease (CKD) and were undergoing hemodialysis or hemofiltration with ESA-naive (erythropoiesis stimulating agent-naive). The primary efficacy profile was the mean Hb level (the non-inferiority margin was -1.0 g/dL, week 21-28); the secondary efficacy profiles were the Hb increase rate (week 0-4), the target Hb achievement cumulative rate and time, the change trends of the Hb levels, and the target Hb maintenance ratio. Adverse events (AEs) were observed and compared, and the efficacy and safety were analyzed between the two treatment groups. Additionally, the frequencies of dose adjustments between the darbepoetin alfa and epoetin alfa groups were compared during the treatment period. SAS® software version 9.2 was used to perform all statistical analyses. Descriptive statistics were used for all efficacy, safety, and demographic variable analyses, including for the primary efficacy indicators. Results: The mean Hb level was 11.3 g/dL in the darbepoetin alfa group and 10.7 g/dL in the epoetin alfa group, respectively; the difference of the lower limits of the 95% confidence intervals (CI) between the two groups was 0.1 g/dL (>-1.0 g/dL), and non-inferiority was proven; the Hb levels started to increase in the first four weeks at a similar increase rate; no obvious differences were observed between the groups in the target Hb achievement cumulative rates, and the Hb levels as well as the target Hb level maintenance rate changed over time. The incidence of AEs was 62.5% in the darbepoetin alfa group and 76.9% in the epoetin alfa group. All the adverse events observed in the study were those commonly associated with hemodialysis. Conclusion: Darbepoetin alfa intravenously once per week can effectively increase Hb levels and maintain the target Hb levels well, which makes it not inferior to epoetin alfa intravenously twice or three times per week. Darbepoetin alfa shows an efficacy and safety comparable to epoetin alfa for the treatment of renal anemia.

4.
J Diabetes Investig ; 12(11): 1983-1991, 2021 Nov.
Article in English | MEDLINE | ID: mdl-33938149

ABSTRACT

AIMS/INTRODUCTION: To evaluate and compare the efficacy of insulin degludec (IDeg) and insulin glargine 300 U/mL (Gla300) 6 months after switching from other basal insulins by assessing the changes in glycated hemoglobin (HbA1c), body mass index (BMI), and insulin doses in patients with type 1 and type 2 diabetes in a real-world clinical setting. MATERIALS AND METHODS: A total of 307 patients with type 1 diabetes and 294 patients with type 2 diabetes with HbA1c >7.0% were studied. Adjusted mean changes in HbA1c, BMI, and insulin doses were compared between IDeg (IDeg group) and Gla300 (Gla300 group) switchers. Multivariable logistic regression analyses were carried out to examine whether the IDeg or Gla300 group was associated with HbA1c or insulin dose reduction and BMI gain. RESULTS: HbA1c was significantly decreased in both the IDeg and Gla300 groups. Adjusted mean changes in HbA1c (approximately -0.3% and -0.5% in type 1 diabetes and type 2 diabetes patients, respectively) and BMI were similar between both groups. The mean change in insulin dose was slightly larger for dose reduction in the IDeg group than in the Gla300 group. Multivariable logistic regression models showed that the IDeg group was significantly associated with insulin dose reduction after adjusting for basal insulin type, insulin dose, and number of basal insulin injections at baseline and other confounding factors. CONCLUSIONS: The current study suggested that IDeg and Gla300 have similar effects in reducing HbA1c and gaining BMI after switching from other basal insulins in Japanese patients with type 1 diabetes and type 2 diabetes. IDeg selection was associated with insulin dose reduction.


Subject(s)
Diabetes Mellitus, Type 1/drug therapy , Diabetes Mellitus, Type 2/drug therapy , Drug Substitution , Hypoglycemic Agents/administration & dosage , Insulin Glargine/administration & dosage , Insulin, Long-Acting/administration & dosage , Adult , Aged , Body Mass Index , Diabetes Mellitus, Type 1/blood , Diabetes Mellitus, Type 2/blood , Female , Glycated Hemoglobin/drug effects , Humans , Insulins/administration & dosage , Japan , Logistic Models , Male , Middle Aged , Retrospective Studies , Treatment Outcome
5.
BMJ Open ; 10(10): e039947, 2020 10 29.
Article in English | MEDLINE | ID: mdl-33122322

ABSTRACT

BACKGROUND: The effects of sleep quality on the risk of developing non-alcoholic fatty liver disease (NAFLD) remain uncertain. The purpose of this study was to clarify the association between sleep quality and NAFLD. METHODS: The data of 4828 participants who underwent health check-ups at four hospitals were analysed. Sleep quality was evaluated by the Pittsburgh Sleep Quality Index (PSQI), which comprised seven elements scored from 0 to 3. The global PSQI score and the score for each element were compared between NAFLD and non-NAFLD groups separately by sex. Logistic regression analysis was performed to determine the association between NAFLD and each PSQI score. RESULTS: In both men and women, the mean PSQI score for sleep medication use was significantly higher in non-NAFLD than in NAFLD. With regard to sleep medication use in men, the OR (95% CI) for NAFLD was lower with a score of 3 (OR 0.60, 95% CI 0.38-0.95) than with a score of 0 on multivariate logistic regression analysis adjusted for age, smoking habits and physical activity. The OR for NAFLD based on daytime dysfunction was also higher with a score of 3 than with a score of 0 in both men (OR 2.82, 95% CI 1.39-5.75) and women (OR 2.08, 95% CI 1.10-3.92). After adjustment for body mass index, the sleep latency scores in men and daytime dysfunction in women were associated with NAFLD. CONCLUSION: Sleep quality was associated with NAFLD, and there were sex differences.


Subject(s)
Non-alcoholic Fatty Liver Disease , Sleep Wake Disorders , Body Mass Index , Cross-Sectional Studies , Female , Humans , Male , Non-alcoholic Fatty Liver Disease/complications , Non-alcoholic Fatty Liver Disease/epidemiology , Risk Factors , Sleep , Sleep Wake Disorders/epidemiology
6.
Expert Rev Mol Diagn ; 20(7): 715-724, 2020 07.
Article in English | MEDLINE | ID: mdl-32513031

ABSTRACT

INTRODUCTION: Among the family of fibroblast growth factors (FGFs), FGF19, FGF21, and FGF23 act as circulating hormones and are called endocrine FGFs. FGF19 and FGF21 regulate bile acid and energy homeostasis, respectively, whereas FGF23 regulates vitamin D and phosphate homeostasis. Accumulating evidence suggests that FGF23 plays a critical role in disturbed mineral metabolisms, left ventricular hypertrophy, immunosuppression, inflammation, among others in patients with chronic kidney disease (CKD), highlighting the potential both as a biomarker and a therapeutic target. Several studies have also examined the potential role of FGF19 and FGF21 in CKD patients. AREAS COVERED: In this review, we present a brief overview of the biology of FGF19, FGF21, and FGF23, and summarize recent clinical and experimental studies on the pathophysiological roles of endocrine FGFs, mainly FGF23, in CKD patients. EXPERT OPINION: Among the endocrine FGFs, FGF23 represents the most promising biomarker in CKD patients. If future studies confirm that FGF23 is directly toxic in CKD patients, FGF23 could be regarded as a therapeutic target and its measurement would be valuable if applied in clinical practice. Despite their potentially important roles, the clinical relevance of FGF19 and FGF21 in CKD patients is unclear, and much more studies are required.


Subject(s)
Fibroblast Growth Factors/blood , Renal Insufficiency, Chronic/blood , Animals , Bile Acids and Salts/metabolism , Biomarkers/blood , Disease Models, Animal , Endocrine System/physiopathology , Fibroblast Growth Factor-23 , Fibroblast Growth Factors/physiology , Glucuronidase/deficiency , Glucuronidase/physiology , Humans , Hypertrophy, Left Ventricular/etiology , Hypertrophy, Left Ventricular/physiopathology , Infections/metabolism , Inflammation/metabolism , Kidney/metabolism , Klotho Proteins , Mice , Minerals/metabolism , Phosphates/metabolism , Rats , Renal Insufficiency, Chronic/complications , Renal Insufficiency, Chronic/physiopathology , Vascular Calcification/metabolism
7.
No Shinkei Geka ; 48(5): 397-405, 2020 May.
Article in Japanese | MEDLINE | ID: mdl-32434950

ABSTRACT

A hybrid operating room(Hybrid OR), where operative equipment and flat panel angiography are both available, is becoming common for complex cerebrovascular surgery. However, the current Hybrid OR remains suboptimal as it is not cost-effective and contains uncomfortable operating beds, and a single-plane flat panel. Therefore, we introduced a novel Hybrid OR system, which has a biplane flat panel detector and three mutually exchangeable tailor-made operating beds. In this article, we report our preliminary experience of this novel Hybrid OR, focusing on improved cost-effectiveness by the availability of diagnostic angiography and standard endovascular surgery, optimal selection of three different types of operating beds, and procedural workflow in individual hybrid cerebrovascular surgery.


Subject(s)
Operating Tables , Angiography , Humans , Neurosurgical Procedures , Operating Rooms , Stereotaxic Techniques
8.
J Bone Miner Metab ; 38(5): 687-694, 2020 Sep.
Article in English | MEDLINE | ID: mdl-32274572

ABSTRACT

INTRODUCTION: Primary hyperparathyroidism (PHPT) is caused by parathyroid adenoma, primary parathyroid hyperplasia, or parathyroid carcinoma. For some patients with PHPT controlling serum calcium levels is critical. MATERIALS AND METHODS: We conducted an open-label, single-arm, 52-week, phase III study in Japanese patients with hypercalcemia due to PHPT to demonstrate efficacy and safety of evocalcet, a new calcimimetic. Patients with intractable PHPT (n = 13), postsurgical recurrence (n = 2), and parathyroid carcinoma (n = 3) were enrolled. Evocalcet administration started at a dose of 2 mg once or twice daily and was titrated to achieve the target serum corrected calcium (cCa) concentration (≤ 10.3 mg/dL) for two consecutive weeks (maximal dose 24 mg/day). RESULTS: Fourteen patients achieved the target (77.8%; 95% confidence interval [CI] 52.4-93.6). The lower limit of 95% CI exceeded the predetermined reference limit (11%), and thus, efficacy was confirmed. Of 18 patients, 12 (66.7%; 95% CI 41.0-86.7) showed decreased serum cCa of ≥ 1.0 mg/dL from the baseline for two consecutive weeks during the titration phase. Sixteen patients entered the maintenance phase, and 15 patients completed the study. Treatment-emergent adverse events (TEAEs) were recorded in 18/18 patients (100%) and drug-related TEAEs in 8/18 (44.4%). The most commonly observed drug-related TEAE was nausea (2/18 patients). No unexpected drug-related TEAEs were observed. All drug-related TEAEs were mild in severity. No patient discontinued the study because of drug-related TEAEs. CONCLUSION: Evocalcet demonstrated long-term effectiveness in reducing serum cCa concentrations and safety without any unexpected drug-related TEAEs in PHPT patients.


Subject(s)
Hyperparathyroidism, Primary/drug therapy , Naphthalenes/therapeutic use , Pyrrolidines/therapeutic use , Calcium/blood , Creatinine/blood , Dose-Response Relationship, Drug , Female , Humans , Hyperparathyroidism, Primary/blood , Male , Middle Aged , Naphthalenes/administration & dosage , Naphthalenes/adverse effects , Naphthalenes/pharmacology , Parathyroid Hormone/blood , Phosphates/blood , Pyrrolidines/administration & dosage , Pyrrolidines/adverse effects , Pyrrolidines/pharmacology
9.
No Shinkei Geka ; 48(2): 151-158, 2020 Feb.
Article in Japanese | MEDLINE | ID: mdl-32094314

ABSTRACT

INTRODUCTION: Astroblastoma is a rare, supratentorial glial tumor, occurring predominantly in children and young adults. However, treatment strategies have not yet been established for this rare disease. CASE PRESENTATION: A 6-year-old boy presented with headache and nausea. CT and MRI revealed a left frontal mass lesion with slight edema and macrocalcifications. Gross tumor resection was performed. Histological examination found neoplastic cells with astroblastic characteristics, and a striking perivascular array of pseudorosettes. The final diagnosis was high-grade astroblastoma. MRI 13 months after surgery suggested local recurrence, and an enlargement was found 3 months later. Stereotactic radiotherapy(SRT)was performed. MRI after SRT showed enhanced cyst formation around the tumor bed, suggesting tumor recurrence. However, 11C-methionine positron emission tomography(PET)revealed radiation necrosis. The last follow-up MRI 15 months after SRT showed no further recurrence. CONCLUSION: Astroblastoma is rare, therefore, no optimal management is known. SRT may be effective to treat recurrent astroblastomas. 11C-methionine PET/CT was useful to differentiate metastatic disease from radiation necrosis.


Subject(s)
Brain Neoplasms/radiotherapy , Neoplasms, Neuroepithelial/radiotherapy , Radiosurgery , Child , Humans , Male , Neoplasm Recurrence, Local , Positron Emission Tomography Computed Tomography
10.
Ther Apher Dial ; 24(3): 248-257, 2020 Jun.
Article in English | MEDLINE | ID: mdl-31486206

ABSTRACT

Patients with chronic kidney disease often develop secondary hyperparathyroidism (SHPT), marked by high levels of circulating parathyroid hormone (PTH) and increased risk of morbidity and mortality. Patients with SHPT are treated with a therapeutic combination that commonly includes calcimimetics, which have recently become popular in clinical settings, and other agents such as vitamin D preparations. Calcimimetics are a drug class that reduces PTH levels by targeting the calcium-sensing receptor. Cinacalcet, a representative calcimimetic, is widely used; however, a high incidence of upper gastrointestinal (GI) tract-related adverse events (AEs) can result in insufficient dosage and poor long-term compliance. The newly approved evocalcet has equivalent efficacy to cinacalcet at a lower clinical dose, with improved bioavailability, fewer upper GI tract-related AEs, and fewer safety concerns. This review gives an overview of calcimimetic agents, with a special focus on evocalcet, and describes the clinical advantages of evocalcet in the treatment of dialysis patients with SHPT.


Subject(s)
Hyperparathyroidism, Secondary , Naphthalenes/pharmacology , Pyrrolidines/pharmacology , Renal Insufficiency, Chronic , Calcimimetic Agents/pharmacology , Drug Discovery , Humans , Hyperparathyroidism, Secondary/drug therapy , Hyperparathyroidism, Secondary/etiology , Receptors, Calcium-Sensing/antagonists & inhibitors , Renal Dialysis/methods , Renal Insufficiency, Chronic/complications , Renal Insufficiency, Chronic/metabolism , Renal Insufficiency, Chronic/therapy , Treatment Outcome
11.
Sci Rep ; 6: 18849, 2016 Jan 06.
Article in English | MEDLINE | ID: mdl-26732094

ABSTRACT

Bone morphogenetic proteins (BMPs) are multi-functional growth factors that belong to the TGF-beta superfamily. Recently, several soluble BMP receptors, such as ActRIIA-Fc, ActRIIB-Fc, and ALK1-Fc, are undergoing clinical trials. Both BMPRIA and BMPRIB are type I BMP receptors, and while BMPRIA-Fc has been reported to have bone-increasing properties, there have been no investigations concerning the biological functions of BMPRIB-Fc. Therefore, comparing the effects of BMPRIA-Fc and BMPRIB-Fc in vivo should be helpful in revealing the differences in biological function between BMPRIA and BMPRIB, and would also aid in the evaluation of BMPRIB-Fc as a therapeutic agent. Here, we produced Tg chimeras in which BMPRIA-Fc and BMPRIB-Fc proteins circulated at high concentrations (36.8-121.4 µg/mL). Both Tg chimeras showed a significant increase of bone volume and strength. Using histological analysis, adenoma of the glandular stomach was observed only in BMPRIA-Fc chimeras suggesting the tumorigenic activity of this protein. Administration of recombinant BMPRIB-Fc protein to normal mice also increased bone volumes. Finally, treatment with BMPRIB-Fc decreased the area of osteolytic regions in a mouse model of breast cancer metastasis. In conclusion, our data suggest that BMPRIB-Fc can be used for the treatment of bone-related disorders with a lower risk than BMPRIA-Fc.


Subject(s)
Bone Diseases/metabolism , Bone Morphogenetic Protein Receptors, Type I/metabolism , Animals , Bone Diseases/diagnosis , Bone Diseases/drug therapy , Bone Morphogenetic Protein Receptors, Type I/blood , Bone Neoplasms/drug therapy , Bone Neoplasms/pathology , Bone Neoplasms/secondary , Bone Substitutes , Disease Models, Animal , Ligands , Mice , Mice, Transgenic , Osteolysis/drug therapy , Protein Binding , Recombinant Proteins/metabolism , Recombinant Proteins/pharmacology , X-Ray Microtomography
12.
Immunol Lett ; 161(1): 31-7, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24792671

ABSTRACT

The effect of conophylline (CNP) on the receptor activator of nuclear factor-κB ligand (RANKL) or lipopolysaccharide (LPS)-induced osteoclast formation was studied in vitro using bone marrow-derived macrophages (BMMs) or the mouse macrophage-like cell line RAW 264.7. CNP inhibited RANKL-induced formation of osteoclasts identified as tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells in a culture of BMMs. It also inhibited RANKL- or LPS-induced osteoclast formation in RAW 264.7 cells. CNP lowered the osteoclast maturation markers such as calcitonin receptor, MMP9 and cathepsin K in BMMs, suggesting that CNP would inhibit the process of osteoclast differentiation. CNP inhibited the RANKL-induced expressions of c-Fos and nuclear factor of activated T cells (NFATc1), key transcription factors for osteoclastogenesis. On the other hand, CNP did not inhibit the signaling pathway of NF-κB and mitogen-activated protein kinases (MAPKs) in RANKL-stimulated BMMs. Interestingly, CNP inhibited RANKL-induced CREB activation that can mediate c-Fos and NFATc1. CNP also inhibited RANKL- or LPS-induced CREB, c-Fos and NFATc1 activation in RAW 264.7 cells. We have previously found that CNP directly binds to ADP-ribosylation-like factor-6 interacting protein (ARL6ip), although its role in osteoclastogenesis is not clear. Gene knockdown of ARL6ip by siRNA inhibited RANKL-induced c-Fos expression, suggesting that inactivation of ARL6ip may be involved in an inhibitory effect of CNP. Taken together, CNP was shown to inhibit osteoclast formation possibly via CREB inactivation following a decrease in c-Fos and NFATc1 expression.


Subject(s)
Cyclic AMP Response Element-Binding Protein/genetics , Gene Expression Regulation/drug effects , Lipopolysaccharides/pharmacology , Osteoclasts/drug effects , Osteoclasts/metabolism , RANK Ligand/pharmacology , Vinca Alkaloids/pharmacology , Animals , Bone Marrow Cells/drug effects , Bone Marrow Cells/metabolism , Cell Line , Cyclic AMP Response Element-Binding Protein/metabolism , Down-Regulation , Mice , Mitogen-Activated Protein Kinases/metabolism , NF-kappa B/metabolism , NFATC Transcription Factors/genetics , Proto-Oncogene Proteins c-fos/genetics , Signal Transduction/drug effects
13.
J Am Chem Soc ; 124(7): 1164-5, 2002 Feb 20.
Article in English | MEDLINE | ID: mdl-11841273

ABSTRACT

The rhodium-catalyzed, terminal-selective borylation of alkanes has been used to modify polyolefins. The functionalization of two materials, polyethylethylene (PEE) of molecular weights 1200 and 37 000, was conducted by combining bis-pinacoldiboron and 2.5 mol % [Cp*RhCl2]2 in neat polymer and heating at 150 degrees C. This procedure causes the polymer and boron reagent to melt, the catalyst to dissolve, and the reaction to form material with boryl groups at the terminal position of the polymer side chains. Oxidation of the borylated material generated polymers with hydroxyl groups at the terminal position of the side chains. The functionalization was conducted at various ratios of boron reagent to monomer. The resulting borylated and subsequent hydoxylated materials were characterized by 1H and 13C NMR spectroscopy, as well as MALDI-MS and GPC. Little change in polymer molecular weight and polydispersity was observed, and these data indicate that scission of the main chain does not occur. Measurements of the Tg of the polymers showed in increase in Tg of up to 50 degrees C after the modification. Thus, homogeneous, catalytic, selective alkane functionalization can be used to modify polymer properties.

15.
Angew Chem Int Ed Engl ; 40(2): 411-414, 2001 Jan 19.
Article in English | MEDLINE | ID: mdl-29712390

ABSTRACT

Unique selectivity, hitherto not observable in ordinary radical and ionic reactions, is achieved with the bowl-shaped tris(2,6-diphenylbenzyl)tin hydride (TDTH; see structure), which has been successfully utilized as a new reducing agent.

16.
Angew Chem Int Ed Engl ; 37(21): 3039-3041, 1998 Nov 16.
Article in English | MEDLINE | ID: mdl-29711140

ABSTRACT

A reaction chamber is formed by a cage compound in which a dicarbonyl guest molecule is encapsulated by two bowl-shaped aluminum tris(2,6-diphenylphenoxide) molecules through Lewis acid-base interactions (structure of complex with 1,4-dimethylpiperazine-2,5-dione depicted). The carbonyl compound held inside the molecular capsule is effectively protected against the approach of external nucleophiles. On the other hand, the chamber is large enough to allow Diels-Alder cycloadditions to take place under mild conditions and with high selectivity.

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