Differences in the HbA1c-lowering efficacy of glucagon-like peptide-1 analogues between Asians and non-Asians: a systematic review and meta-analysis

AIMS

To compare the HbA1c-lowering efficacy of glucagon-like peptide-1 (GLP-1) analogues between Asians and non-Asians with type 2 diabetes.

METHODS

We searched randomized controlled trials from MEDLINE, EMBASE, LILACS, CENTRAL and ClinicalTrials.gov. Studies described in English were included if the treatment duration was 12 weeks or more, information about ethnicity and baseline HbA1c values were available and a GLP-1 analogue was compared with a placebo. For the ethnic comparison, we divided the studies into Asian-dominant studies (≥ 50% Asian participants) and non-Asian-dominant studies (<50% Asian participants).

RESULTS

Among the 837 searched studies, 15 trials were included for the meta-analysis. The weighted mean difference of HbA1c with GLP-1 analogues was -1.16% [95% confidence interval (CI) -1.48, -0.85] in the Asian-dominant studies and -0.83% (95% CI -0.97, -0.70) in the non-Asian-dominant studies. The between-group difference was -0.32% (95% CI -0.64, -0.01; p = 0.04). The relative risk (RR) with 95% CIs for achieving the target HbA1c ≤ 7.0% tended to be greater in the Asian-dominant studies [RR 5.7 (3.8, 8.7)] than in the non-Asian-dominant studies [RR 2.8 (2.4, 3.3)]. Body weight changes were similar between the two groups. Hypoglycaemia tended to be more common in Asian-dominant studies (RR 2.8 [2.3, 3.5]) than in non-Asian-dominant studies (RR 1.5 [1.2, 1.8]), but severe hypoglycaemia was very rare in both groups.

CONCLUSION

GLP-1 analogues lower HbA1c more in Asian-dominant studies than in non-Asian-dominant studies. Further studies are warranted to explore the potential mechanisms of the ethnic difference.

Investigation of thermal and electrical stabilities of a GdBCO coil using grease as an insulation material for practical superconducting applications

This paper presents the effects of thermal grease on the electrical and thermal characteristics of GdBCO pancake coils, observed through charge-discharge, sudden discharge, over-current, and thermal quench testing. In charge-discharge and sudden discharge tests, a coil using thermal grease as an insulation material demonstrated faster charging/discharging rates compared to a coil without turn-to-turn insulation. In the case of over-current tests, the coil using thermal grease exhibited the highest electrical stability. Furthermore, thermal quench testing showed the coil employing thermal grease to possess superior thermal characteristics, with rapid cooling and low temperature rise. Overall, the use of thermal grease as an insulation material may be a potential solution to the problems observed with the existing insulation materials, possessing fast charging/discharging rates with superior thermal and electrical stabilities.

Lipomembranous changes associated with systemic lupus erythematosus

Lipomembranous changes are distinctive histopathological findings, which include the presence of cystic cavities lined by crenulated, hyaline membranes in adipose tissue. It is likely that ischaemia is fundamental to the development of these lesions, and that lipomembranes are formed from the products of degenerating fat cell membranes by some unknown mechanism. Such changes may be seen, although rarely, in many types of subcutaneous inflammatory processes. However, an association with systemic lupus erythematosus (SLE) is rare. We report a patient with SLE who had the histological features of lipomembranous changes associated with vasculopathy.

A long-term survival case of a primary malignant intracerebral nerve sheath tumor

We report a long-term survival case of a primary malignant intracerebral nerve sheath tumor (MINST) occurring in the right frontal lobe of a 13-year old boy. After the gross total resection (GTR), we have performed radiation therapy but it recurred 50 months after the surgery, so the second GTR was performed. Later, second tumor recurrence was found 4 months after the second surgery. Subsequently the third GTR, radiotherapy, and chemotherapy were carried out. At present, the patient has been remaining alive for 77 months without evidence of tumor recurrence. According to the previous reports, the primary MINST is very rare : there are only 8 cases reported. It is also a fast-growing, invasive tumor with poor outcome. This is the first case that had no recurrence for 50 months after the surgery among the reported cases that had been followed up for more than 5 years. It is supposed that a period of recurrence free survival after GTR and low mitotic activity are associated with the patient's prognosis. A GTR followed by adjuvant radiation therapy and chemotherapy will be recommended to patients of MINST.

Differences in the glucose-lowering efficacy of dipeptidyl peptidase-4 inhibitors between Asians and non-Asians: a systematic review and meta-analysis

AIMS/HYPOTHESIS

The aim of this work was to compare the glucose-lowering efficacy of dipeptidyl peptidase-4 (DPP-4) inhibitors between Asian and non-Asian patients with type 2 diabetes.

METHODS

We searched MEDLINE, EMBASE, LILACS, CENTRAL, ClinicalTrials.gov and conference proceedings. Studies were eligible if they were randomised controlled trials with a treatment duration of at least 12 weeks, compared a DPP-4 inhibitor with a placebo as either monotherapy or oral combination therapy, had information on ethnicity and HbA1c values and were published or described in English. A systematic review and meta-analysis with a meta-regression analysis was conducted.

RESULTS

Among 809 potentially relevant studies, 55 trials were included. A meta-analysis revealed that DPP-4 inhibitors lowered HbA1c to a greater extent in studies with ≥50% Asian participants (weighted mean difference [WMD] -0.92%; 95% CI -1.03, -0.82) than in studies with <50% Asian participants (WMD -0.65%; 95% CI -0.69, -0.60). The between-group difference was -0.26% (95% CI -0.36, -0.17, p < 0.001). The baseline BMI significantly correlated with the HbA1c-lowering efficacy of DPP-4 inhibitors. The RR of achieving the goal of HbA1c <7.0% (53.0 mmol/mol) was higher in studies with ≥50% Asian participants (3.4 [95% CI 2.6, 4.7] vs 1.9 [95% CI 1.8, 2.0]). The fasting plasma glucose-lowering efficacy was higher with monotherapy in the Asian-dominant studies, but the postprandial glucose-lowering efficacy and changes in body weight were comparable between the two groups.

CONCLUSIONS/INTERPRETATION

DPP-4 inhibitors exhibit a better glucose-lowering efficacy in Asians than in other ethnic groups; this requires further investigation to understand the underlying mechanism, particularly in relation to BMI.

Anti-inflammatory effect of sinomenine by inhibition of pro-inflammatory mediators in PMA plus A23187-stimulated HMC-1 Cells

BACKGROUND AND OBJECTIVES

Sinomenine is an alkaloid compound and a prominent anti-inflammatory agent found in the root of the climbing plant Sinomenium acutum. However, its effects on the mechanism of human mast cell line (HMC)-1-mediated inflammation remained unknown.

MATERIALS AND METHODS

To provide insight into the biological effects of sinomenine, we examined its influence on the pro-inflammatory cytokine production in HMC-1 cells stimulated by phorbol 12-myristate-13-acetate (PMA) plus A23187 by evaluating the stimulated cells in the presence or absence of sinomenine. In the present study, the pro-inflammatory cytokine production was measured using ELISA, Reverse Transcription-polymerase chain reaction (RT-PCR) and nuclear factor (NF)-kappaB, mitogen-activated protein kinases (MAPKs) pathway activation, as determined by Western blot analysis. Also, cyclooxygenase (COX)-2 expression was measured through Western blot and RT-PCR analysis.

RESULTS

Sinomenine inhibited the pro-inflammatory cytokine production induced by PMA plus A23187 in a dose-dependent manner. Furthermore, sinomenine inhibited the phosphorylations of extracellular signal-regulated kinase (ERK) and p38 MAPKs as well as the translocation of NF-kappaB p65 through reduced IkappaBalpha degradation. In addition, sinomenine suppressed COX-2 protein and mRNA expression dose-dependently.

CONCLUSIONS

Taken together, the results of this study indicate that the anti-inflammatory effects of sinomenine may occur via the inhibition of pro-inflammatory cytokine and COX-2 production through the inhibition of MAPKs and NF-kappaB pathway activation by PMA plus A23187 stimulation in HMC-1 cells.

Combined therapy of temozolomide and ZD6474 (vandetanib) effectively reduces glioblastoma tumor volume through anti-angiogenic and anti-proliferative mechanisms

Currently, clinically available options for treating glioblastoma (GBM) are quite limited, and there is a clear need to develop novel treatment strategies that can more effectively manage tumors. Here, we present a combination treatment of temozolomide (TMZ), a blood-brain barrier penetrating DNA alkylating agent, and ZD6474 (vandetanib), a VEGFR2 and EGFR dual-targeting anti-angiogenic agent, as a novel treatment strategy for GBM. In a U-87MG orthotopic xenograft model, the combination treatment provided a marked 94% tumor volume reduction. This reduction was greater than that achieved by monotherapy of either agent, and was correlated with a statistically significant reduction in microvessel density (CD31+ cells) and proliferation (PCNA+ cells). These results confirm the necessity to target angiogenesis in addition to utilizing cytotoxic approaches, and provide the rationale for application of TMZ + ZD6474 combination therapy for treating GBM patients in the clinical setting.

ε-Acetamidocaproic acid pharmacokinetics in rats with gastric ulcer or small bowel inflammation

The pharmacokinetics of ϵ-acetamidocaproic acid (AACA) were evaluated after the intravenous and oral administration of an antiulcer agent, zinc acexamate (ZAC) at a dose of 20 mg kg⁻¹ (ion pairing between zinc and AACA) in rats with indomethacin-induced acute gastric ulcer (IAGU) or indomethacin-induced small bowel inflammation (ISBI). In IAGU rats, the area under the curves (AUCs) of AACA were significantly smaller after both the intravenous (551 versus 1270 μg min ml⁻¹) and oral (397 versus 562 μg min ml⁻¹) administration of ZAC than controls, possible due to the significantly faster CL(R) of AACA. In ISBI rats, however, the AUCs of AACA were comparable with controls after both the intravenous and oral administration of ZAC. In IAGU rats, the significantly smaller AUCs of AACA were due to the significantly faster CL(R) (due to the decreased urinary pH by indomethacin treatment) than controls. AACA has a basic secondary amine group. On the other hand, the comparable AUCs of AACA in ISBI rats were due to the comparable CL(R)s between ISBI and control rats. AACA was excreted in the urine via active renal tubular secretion in all rats studied.

Resolvin D1 attenuates activation of sensory transient receptor potential channels leading to multiple anti-nociception

BACKGROUND AND PURPOSE

Temperature-sensitive transient receptor potential ion channels (thermoTRPs) expressed in primary sensory neurons and skin keratinocytes play a crucial role as peripheral pain detectors. Many natural and synthetic ligands have been found to act on thermoTRPs, but little is known about endogenous compounds that inhibit these TRPs. Here, we asked whether resolvin D1 (RvD1), a naturally occurring anti-inflammatory and pro-resolving lipid molecule is able to affect the TRP channel activation.

EXPERIMENTAL APPROACH

We examined the effect of RvD1 on the six thermoTRPs using Ca(2+) imaging and whole cell electrophysiology experiments using the HEK cell heterologous expression system, cultured sensory neurons and HaCaT keratinocytes. We also checked changes in agonist-specific acute licking/flicking or flinching behaviours and TRP-related mechanical and thermal pain behaviours using Hargreaves, Randall-Selitto and von Frey assay systems with or without inflammation.

KEY RESULTS

RvD1 inhibited the activities of TRPA1, TRPV3 and TRPV4 at nanomolar and micromolar levels. Consistent attenuations in agonist-specific acute pain behaviours by immediate peripheral administration with RvD1 were also observed. Furthermore, local pretreatment with RvD1 significantly reversed mechanical and thermal hypersensitivity in inflamed tissues.

CONCLUSIONS AND IMPLICATIONS

RvD1 was a novel endogenous inhibitor for several sensory TRPs. The results of our behavioural studies suggest that RvD1 has an analgesic potential via these TRP-related mechanisms.

Total synthesis of pareitropone via radical anion coupling

A concise (9-step) synthesis of the tropoloisoquinoline alkaloid pareitropone has been achieved starting from 2-bromoisovanillin. The key step features oxidative cyclization of a readily available phenolic nitronate for the convenient construction of the fused tropone ring. This work underscores the synthetic utility of intramolecular oxidative coupling reactions of phenolic nitronates.

The pi40 gene for durable resistance to rice blast and molecular analysis of pi40-advanced backcross breeding lines

Rice blast severely reduces production in both irrigated and water-stressed upland ecosystems of tropical and temperate countries. Nearly 50 blast resistance genes have been identified and some of those are incorporated into several rice cultivars. However, most of the resistance genes break down in a few years because of their race specificity and the rapid change in pathogenicity of the blast fungus (Magnaporthe grisea). The objective of this study was to analyze advanced backcross breeding lines (ABL) possessing the gene Pi40 for durable rice blast resistance. In all, 4 resistant genotypes, 4 japonica cultivars, and 10 monogenic differential rice genotypes with some known resistance genes were bioassayed in the greenhouse using seven sequential plantings and 29 virulent M. grisea isolates of Korea. The genotypes with the Pi40 gene had <3% diseased leaf area, which was significantly below the disease threshold level of 40% considered for durable blast resistance. Moreover, the genotypes with the Pi40 gene expressed compatibility with only two to three virulent M. grisea isolates supporting durability of resistance, in contrast to susceptible cultivars with >50% diseased leaf area and 10 compatible isolates. Of the 10 known resistance genes tested, Piz-t, Piz-5, and Pi9 showed differential reactions to the pathogen isolates in seven plantings. Genotyping of the ABL with 260 simple sequence repeat (SSR) markers revealed rapid conversion toward recurrent parent genotypes with fewer donor chromosomal segments (5.3 to 14.5%). Our study based on a sequential testing and background selection of breeding lines with the resistance gene Pi40 provided valuable information for durable blast resistance breeding in rice.

Interaction between udenafil and tamsulosin in rats: non-competitive inhibition of tamsulosin metabolism by udenafil via hepatic CYP3A1/2

BACKGROUND AND PURPOSE

Orthostatic hypotension has been observed when PDE 5 (cGMP-specific phosphodiesterase type 5) inhibitors are co-administered with alpha-adrenoceptor antagonists. Here we assessed the pharmacokinetic and haemodynamic interactions between udenafil and tamsulosin in rats, as both drugs are metabolized via rat hepatic cytochrome P450 3A1/2.

EXPERIMENTAL APPROACH

Interactions between the two drugs were evaluated in rats after simultaneous 1 or 15 min i.v. infusion or after p.o. administration of udenafil (30 mg x kg(-1)) and/or tamsulosin (1 mg x kg(-1)). In vitro metabolism of tamsulosin with udenafil was measured to obtain the inhibition constant (K(i)) and [I]/K(i) ratio of udenafil.

KEY RESULTS

The total area under the plasma concentration-time curve from time zero to time infinity (AUC)s (or AUC(0-4 h)) of tamsulosin were significantly greater after 15 min of i.v. infusion or after oral administration with udenafil, compared with tamsulosin alone. The hepatic first-pass metabolism of tamsulosin was inhibited by udenafil, and the inhibition in vitro was in a non-competitive mode. The arterial systolic blood pressure was significantly lower at 5, 10 and 60 min after oral co-administration of the drugs.

CONCLUSIONS AND IMPLICATIONS

The significantly greater AUC of tamsulosin after i.v. and p.o. administration of both drugs may be attributable to non-competitive inhibition of cytochrome P450 3A1/2-mediated hepatic tamsulosin metabolism by udenafil. The inhibition was also observed in human liver S9 fractions, suggesting that a reassessment of the oral dosage of tamsulosin is necessary when udenafil and tamsulosin are co-administered to patients with benign prostatic hyperplasia.

Serum cholesterol in idiopathic and lupus-related protein-losing enteropathy

Abstract The characteristics of protein-losing enteropathy were evaluated in patients with systemic lupus erythematosus. Among the patients with systemic lupus erythematosus (n=380) in a tertiary hospital, we reviewed the records of seven patients with generalized edema, hypoalbuminemia without proteinuria and positive results on 99mTc-labelled human serum albumin scintigrams. Patient characteristics and laboratory findings were compared between these seven patients and patients with lupus enteritis (n=15) or idiopathic protein-losing enteropathy (n=11). Compared with the lupus enteritis patients, the erythrocyte sedimentation rate and serum total cholesterol levels were significantly increased in patients with systemic lupus erythematosus-related protein-losing enteropathy. Compared with idiopathic protein-losing enteropathy patients, the level of serum total cholesterol was significantly increased, but the level of serum albumin was decreased in patients with systemic lupus erythematosus-related protein-losing enteropathy. Among patients with systemic lupus erythematosus-related protein-losing enteropathy, four patients had high serum total cholesterol levels (>or=248 mg/dL) and achieved complete remission after receiving high doses of steroid treatment. However, three patients who had low serum total cholesterol levels (<or=219 mg/dL) responded poorly to the steroid-only treatment, and could achieve complete remission only after 3 months of cyclophosphamide pulse treatment with concurrent corticosteroid therapy. The levels of serum total cholesterol are intriguing feature in systemic lupus erythematosus-associated protein-losing enteropathy patients.

Systemic lupus erythematosus complicated by acquired von Willebrand’s syndrome

Haematological abnormalities are common in systemic lupus erythematosus (SLE). In some cases of acquired von Willebrand syndrome (AvWS), von Willebrand disease (vWD) is associated with autoimmune or lymphoproliferative disorders. In this study, we describe a 36-year-old woman with SLE and AvWS. The patient was referred to our hospital because of easy bruisability and recurrent vaginal bleeding. She had no history of bleeding tendency and no family history of bleeding diathesis, but she had a history of recurrent arthralgia, photosensitivity and sicca symptoms. Tests for antinuclear, anti–double stranded DNA, anticardiolipin and anti–β2-glycoprotein I antibodies were all positive. Analysis of haemostatic parameters showed complete absence of von Willebrand factor ristocetin cofactor (vWF:Rco), von Willebrand antigen (vWF:Ag) and ristocetin-induced platelet aggregation (RIPA). Electrophoretic analysis of plasma showed a complete absence of high–molecular weight vWF multimer. The presence of antibody to vWF was detected by enzyme linked immunosorbent assay (ELISA). Treatment with corticosteroids improved SLE symptoms and corrected bleeding diasthesis. Also, the multimeric patterns of vWF became normalised and anti–vWF antibody disappeared. These findings indicated that this patient had SLE associated with AvWS, which was ameliorated by corticosteroid treatment.

Behcet's disease associated with bone marrow failure in Korean patients: clinical characteristics and the association of intestinal ulceration and trisomy 8

OBJECTIVES

The aim of this study was to determine the clinical characteristics of Behcet's disease (BD) associated with bone marrow failure (BMF), classified as conditions such as myelodysplastic syndrome (MDS) or aplastic anaemia (AA), in Korea.

METHODS

A retrospective analysis was made of 13 patients with BD associated with BMF (MDS 8 cases, AA 5 cases) and 66 patients with BD not associated with BMF. These patients all fulfilled the diagnostic criteria of the international BD study group.

RESULTS

BD patients with BMF showed significantly lower leucocyte count, haemoglobin level and platelet count when compared with patients without BMF (P < 0.001). BD patients with BMF had significantly higher serum CRP level at the time of BD diagnosis compared with patients without BMF (P = 0.03). Intestinal lesions were more frequent in BD patients with BMF than those without BMF (61.5% vs 13.6%, P = 0.001). Cytogenetic abnormality was observed in 90.9% of BD patients with BMF. Of the cytogenetic abnormalities, trisomy 8 was most common, occurring in 70% of the patients. In four patients with refractory BD associated with BMF, successful treatment of BMF by haematopoietic stem cell transplantation resulted in clinical remission of BD.

CONCLUSIONS

Our study indicates that intestinal ulceration is a characteristic finding in BD associated with BMF. It also suggests that cytogenetic aberration, especially trisomy 8, may play an important role in the pathogenesis of BD associated with BMF.

Molecular modeling, synthesis, and screening of new bacterial quorumsensing antagonists

Abstract A new series comprising 7 analogs of N-(sulfanyl ethanoyl)-L-HSL derivatives, 2 analogs of N-(fluoroalkanoyl)- L-HSL derivatives, N-(fluorosulfonyl)-L-HSL, and 2,2-dimethyl butanoyl HSL were synthesized using a solid-phase organic synthesis method. Each of the 11 synthesized compounds was analyzed using NMR and mass spectroscopies, and molecular modeling studies of the 11 ligands were performed using SYBYL packages. Thereafter, a bacterial test was designed to identify their quorum-sensing inhibition activity and antifouling efficacy. Most of the synthesized compounds were found to be effective as quorum-sensing antagonists, where antagonist screening revealed that 10 among the 11 synthesized ligands were able to antagonize the quorum sensing of A. tumefaciens.

betaPak-interacting exchange factor-mediated Rac1 activation requires smgGDS guanine nucleotide exchange factor in basic fibroblast growth factor-induced neurite outgrowth

Neuritogenesis requires active actin cytoskeleton rearrangement in which Rho GTPases play a pivotal role. In a previous study (Shin, E. Y., Woo, K. N., Lee, C. S., Koo, S. H., Kim, Y. G., Kim, W. J., Bae, C. D., Chang, S. I., and Kim, E. G. (2004) J. Biol. Chem. 279, 1994-2004), we demonstrated that betaPak-interacting exchange factor (betaPIX) guanine nucleotide exchange factor (GEF) mediates basic fibroblast growth factor (bFGF)-stimulated Rac1 activation through phosphorylation of Ser-525 and Thr-526 at the GIT-binding domain (GBD). However, the mechanism by which this phosphorylation event regulates the Rac1-GEF activity remained elusive. We show here that betaPIX binds to Rac1 via the GBD and also activates the GTPase via an associated GEF, smgGDS, in a phosphorylation-dependent manner. Notably, the Rac1-GEF activity of betaPIX persisted for an extended period of time following bFGF stimulation, unlike other Rho GEFs containing the Dbl homology domain. We demonstrate that C-PIX, containing proline-rich, GBD, and leucine zipper domains can interact with Rac1 via the GBD in vitro and in vivo and also mediated bFGF-stimulated Rac1 activation, as determined by a modified GEF assay and fluorescence resonance energy transfer analysis. However, nonphosphorylatable C-PIX (S525A/T526A) failed to generate Rac1-GTP. Finally, betaPIX is shown to form a trimeric complex with smgGDS and Rac1; down-regulation of smgGDS expression by short interfering RNA causing significant inhibition of betaPIX-mediated Rac1 activation and neurite outgrowth. These results provide evidence for a new and unexpected mechanism whereby betaPIX can regulate Rac1 activity.

The JAK2 V617F mutation in de novo acute myelogenous leukemias

A missense somatic mutation in JAK2 gene (JAK2 V617F) has recently been reported in chronic myeloproliferative disorders, including polycythemia vera, essential thrombocythemia and myelofibrosis with myeloid metaplasia, strongly suggesting its role in the pathogenesis of myeloid disorders. As activation of JAK2 signaling is occurred in other malignancies as well, we have analysed 558 tissues from common human cancers, including colon, breast and lung carcinomas, and 143 acute adulthood leukemias by polymerase chain reaction -- single strand conformation polymorphism analysis. We found three JAK2 mutations in the 113 acute myelogenous leukemias (AMLs) (2.7%), but none in other cancers. The mutations consisted of two V617F mutations and one K607N mutation. None of the AML patients with the JAK2 V617F mutation had a history of previous hematologic disorders. This is the first report on the JAK2 gene mutation in AML, and the data indicated that the JAK2 gene mutation may not only contribute to the development of chronic myeloid disorders, but also to some AMLs.

Stereoselective Synthesis of Protected (2R,3R,4S)-4,7-Diamino-2,3-dihydroxyheptanoic Acid: A Novel Amino Acid of Callipeltins A and D

An orthogonally protected derivative 1 of (2R,3R,4S)-4,7-diamino-2,3-dihydroxyheptanoic acid, the unusual amino acid residue of the biologically active marine peptides such as callipeltins A and D and neamphamide A, was efficiently prepared in 10 steps and 30% overall yield from a commercially available L-ornithine derivative 2. The key step includes the N-diphenylmethylene-controlled diastereoselective dihydroxylation of (Z)-ester 3 with >13:1 selectivity for the desired isomer.

UV photolytic mechanism of N-nitrosodimethylamine in water: dual pathways to methylamine versus dimethylamine

The direct ultraviolet (UV) photolysis of N-nitrosodimethyl-amine (NDMA), a well-known potential carcinogen, was investigated in aqueous solution with its degradation products analyzed quantitatively. NDMA is known to be photolyzed either to dimethylamine (DMA) or to methylamine (MA) by two distinct pathways. However, the mechanism through which NDMA is photolyzed to DMA is still not clearly understood. This study reveals a new mechanistic pathway of NDMA photolysis to DMA by identifying the factors influencing the photolysis pathway. The two pathways of NDMA photolysis were found to be strongly dependent on the initial NDMA concentration and solution pH. Increasing the initial NDMA concentration clearly favored the DMA formation path. DMA production was optimized in the region of pH 4-5. The nitrite ion (NO2-) produced from the NDMA photolysis was identified as a key reagent in directing the NDMA photolysis toward DMA production. The observed photolytic behaviors of NDMA photolysis could be successfully explained in terms of the new mechanism involving the role of NO2-.

Stereoselective dihydroxylation reactions of γ-amino-α,β-unsaturated esters via their aryl ketimine derivatives

OsO4-catalysed dihydroxylation reactions of the aryl ketimine derivatives of (E)-gamma-amino-alpha,beta-unsaturated esters gave anti selectivity ranging from 6.7 : 1 to 19 : 1, whereas the opposite syn selectivity was consistently observed with those of (Z)-gamma-amino-alpha,beta-unsaturated esters (5.4 : 1 to > 100 : 1).

Effect of panel-reactive antibody positivity on graft rejection before or after kidney transplantation

INTRODUCTION

Because it is well known that kidney transplant recipients with preformed lymphocytotoxic antibodies against HLA antigens have increased graft rejection rates, a serological crossmatch is routinely performed before kidney transplantation. But, the presence of these antibodies is not routinely monitored after transplantation. We investigated the panel-reactive antibody (PRA) response to know whether variations before or after kidney transplantation were associated with graft rejection.

METHODS

We prospectively analyzed sera from 350 renal allograft recipients from September 1998 to March 2003. Pretransplantation and posttransplantation sera at 3 or 5 weeks postoperatively were tested in PRA. Recipients were stratified into 3 groups according to their PRA levels group I, PRA = 0; group II, PRA = less than 50%, and group III, PRA = more than 50%.

RESULTS

The total graft rejection rate among 350 recipients was 9.4% (n = 33). Twenty-four pretransplantation PRA-positive recipients had a graft rejection rate of 20.8% (n = 5), compared with an 8.6% (n = 28) rate among 326 pretransplantation PRA-negative recipients. Six of 24 posttransplantation PRA-positive recipients (25%) experienced a graft rejection versus 27 (8.3%) of 326 posttransplantation PRA-negative subjects. Among the pretransplantation PRA stratae, the rejection rate in group III was 25% (1 of 4) versus 20% (4 of 20) in group II and 8.6% (28 of 326) in group I (P < .05). According to the postransplantation PRA level, 37.5% (3 of 8) in group III versus 18.8% (3 of 16) in group II and 8.3% (27 of 326) in group I (P < .05) had a graft rejection.

CONCLUSION

Our study suggests that the PRA response pretransplantation and in the early posttransplantation period correlates with the kidney allograft rejection rate.

Prognostic factors affecting graft and patient survival in cadaveric and living kidney transplantation

Numerous studies have reported various prognostic factors that affect graft and patient survival in living and cadaveric donor kidney transplantation (KT). The purpose of this study was to evaluate the clinical outcomes and prognostic factors affecting graft and patient survivals in living and cadaveric donor KT. Between February 1995 and December 2001, 421 patients who had undergone cadaveric donor KT (group I: 216 cases, 51.3%) or living donor KT (group II: 205 cases, 48.7%), were retrospectively analyzed. Five-year overall graft survival rates in living was significantly better than that in cadaveric donor KT, respectively (P = .0234). There was no difference in patient survival rates between the two groups. Such factors as absence of rejection, female donor, female recipient, adult KT according to recipient age (>14 years), and donor serum creatinine level just before transplantation (< 2.5 mg/dL) were significantly associated with good graft survival among cadaveric donor KT, whereas two factors-absence of rejection and adult KT according to recipient age (>14 years)-influenced graft survival in living donor KT. In multivariate analysis, the only significant prognostic factor related to graft survival was the presence of rejection. In conclusion, we suggest that the presence of rejection is the only factor that impairs graft survival in both cadaveric and living donor KT, while other factors affected graft survival differently in the two groups.

Bioequivalence of a prednisolone tablet administered as a single oral dose in healthy male volunteers

OBJECTIVE

A bioequivalence study ofprednisolone as Nisolone (test) tablets versus Delta-Cortef (reference) tablets was conducted.

PATIENTS AND METHODS

Eighteen healthy male Korean volunteers received both 20 mg formulations of prednisolone in this 2 x 2 crossover study with a 1-week washout period between the doses. Plasma concentrations of prednisolone were monitored over a period of 12 hours after the administration using high-performance liquid chromatography. The AUC (area under the plasma concentration-time curve from time zero to infinity) and AUCt (area under the plasma concentration-time curve from time zero to the last sampling time) were calculated using the trapezoidal rule-extrapolation method. The Cmax (maximum plasma drug concentration) and t(max) (time to reach Cmax) were compiled from the plasma concentration-time data. Analysis of variance was carried out using logarithmically transformed AUC, AUCt and Cmax and untransformed t(max).

RESULTS

The geometric mean of AUCt was 1,786 ng/ml x h (test medication) and 1,787 ng/ml xh (reference medication). A Cmax of 409 ng/ml and 404 ng/ml was achieved for the test and the reference medication, respectively. Point estimates and 90% confidence intervals for AUCt (parametric) and Cmax (parametric) were 0.989 (0.942 approximately 1.039) and 1.013 (0.934 approximately 1.100), respectively. These results satisfy the bioequivalence criteria of the European Committee for Proprietary Medicinal Products and the US Food and Drug Administration Guidelines. The corresponding value of t(max) was -0.221 (-0.415 approximately 0.000).

CONCLUSION

The 2 medications of prednisolone examined are bioequivalent and, thus, may be prescribed interchangeably.

Polymerase chain reaction for the diagnosis of human polyomavirus-associated nephropathy in renal transplant recipients

Human polyomavirus type BK may be related to interstitial nephropathy or renal-allograft dysfunction. Patients with nephropathy due to infection with human polyomavirus may be identified early using the polymerase chain reaction(PCR). We attempted to evaluate whether the positive response in the PCR test of BK virus DNA in the plasma of renal transplant recipients affects the function of the renal allograft. Seventy-seven patients were prospectively analyzed according to the operative sex, age, sources of allograft, serum creatinine levels during PCR test for BK virus, postoperative type of immunosuppressant, and presence of graft rejection. Two groups were distinguished according to the PCR result for BK virus: group 1 (n = 12) positive PCR reaction and group 2 (n = 65) negative reaction. The mean follow-up was 32.6 weeks. The incidence of positive PCR tests for BK virus replication after renal transplantation was 15.6%. Decoy cells in the urine were detected in 20.7%. The incidence of BK virus nephropathy was 1.3%. The mean serum creatinine levels of group 1 and 2 at the time of the PCR tests were 1.34 and 1.22, respectively. The rejection rates in group 1 and 2 were 8% and 4.5%, respectively (P > .05). We consider that a PCR assay to detect BK virus in renal recipients blood may be useful to identify patients at risk for nephropathy. It may serve as a noninvasive indicator of BK virus replication, although this study is limited by the short follow-up and small numbers.