2-甲基-7-亚甲基-1,4,6-三氧螺[4,4]壬烷与丙烯腈、丙烯酸甲酯的共聚合反应及竞聚率的测定

用高效液相色谱跟踪2-甲基-7-亚甲基-1,4,6-三氧螺[4,4]壬烷(MMTN)与丙烯腈(AN),丙烯酸甲酯(MA)的共聚合反应。根据Lowry-Meyer共聚积分方程式,采用插值法进行数据拟合测定单体的竞聚率。对于体系MMTN(M_1)-AN(M_2),r_1=0.048;r_2=0.213;MMTN(M_1)-MA(M_2)r_1=0.025,r_2=0.764。说明两组共聚体系均有较强的交替共聚趋势。     

Gorog Thrombosis Test: analysis of factors influencing occlusive thrombus formation.

We used the Gorog Thrombosis Test to analyze the factors influencing the occlusion time, which represents platelet activation and subsequent occlusive thrombus formation, in 132 healthy Japanese volunteers (116 men, 16 women; mean age, 45.0 +/- 12.0 years). The Gorog Thrombosis Test was designed to evaluate platelet aggregation and thrombolytic activity under a high shear stress condition (175 dynes/cm) in a native blood sample in vitro. The mean +/- SD occlusion time was 154.8 +/- 64.7 s (men, 153.4 +/- 64.2 s and women, 165.4 +/- 56.5 s). The occlusion time was inversely correlated with von Willebrand factor ristocetin cofactor activity (VWF:Rco) (r = -0.242, P = 0.0055) and von Willebrand factor antigen (r = -0.230, P = 0.0080). The mean occlusion time in the group with VWF:Rco of at least 170% (137 s) was significantly shorter than that in the group with VWF:Rco less than 170% (156 s, P < 0.05). Platelet counts, other coagulation markers and smoking showed no significant correlations with occlusion time. Red blood cells (r = -0.177, P = 0.0365), hemoglobin (r = -0.191, P = 0.0245) and hematocrit (r = -0.182, P = 0.0329) also showed inverse correlations with the occlusion time. This report is the first to clearly demonstrate the role of von Willebrand factor in the formation of occlusive thrombi in the Gorog Thrombosis Test.     

Surgical treatment for intrathoracic aneurysm of the innominate artery in an 83-year-old asymptomatic woman

Aneurysm of the innominate artery is uncommon compared with other peripheral aneurysms, and holds the potential for rupture, embolization, or thrombosis as well as various complications caused by compression to the adjacent structures. The most effective treatment for this condition is surgical resection, but the earlier reports described high mortality rates. We report the case of an 83-year-old asymptomatic woman with an aneurysm in the innominate artery, which was successfully resected and repaired with the use of modern surgical techniques of hypothermic circulatory arrest and selective cerebral perfusion. Aggressive surgical intervention should be employed despite the fact that a patients is asymptomatic.     

Analysis of small dense LDL in patients with type 2 diabetic mellitus by the modified Krauss method using an internal standard

In patients with Type 2 diabetes mellitus (Type 2 DM), the relationship between the prevalence rate of small dense LDL (sdLDL) and parameters of lipid metabolism was analyzed using the method devised by modified Krauss method using apoferritin as an internal standard. The prevalence rate of sdLDL was 34% compared with it of normal subjects in this study. When the severity of Type 2 DM was classified into three groups of the HbA1c value, neither the sdLDL size nor its prevalence rate differed significantly depending upon the severity of the Type 2 DM. Also, when the prevalence rate of sdLDL was analyzed in relation to the severity of complications, i.e., of microangiopathy (retinopathy and nephropathy) or macroangiopathy (cerebral infarction), there was no significant difference in the prevalence rate of sdLDL depending on the severity of any of these complications. On the other hand, the prevalence rate of sdLDL was found to be correlated with the serum TG level. The serum level of TG-rich remnants (metabolites of TG) was also high in patients with sdLDL. It should take notice that the assessment of sdLDL should be used the authorized method for the evaluation. Thus it is concluded that the levels of sdLDL were important in evaluation of Type 2 DM. The prevalence rate of sdLDL did not correlate with the severity, nor the modalities for the complications of Type 2 DM.     

Copolymerization of 1,6-anhydro-sugar derivatives with cyclic monomers, 1. Tri-O-benzyl ether and tri-O-methyl ether of 1,6-anhydro-ß-D-glucopyranose as sugar monomers

The cationic, ring-opening copolymerization of 1,6-anhydro-2,3,4-tri-O-benzyl-ß-D -glucopyranose with epichlorohydrin, 3,3-bis(chloromethyl)oxetane and 1,3-dioxolane was investigated with phosphorus pentafluoride as catalyst at low temperatures. Besides, copolymerization of 1,6-anhydro-2,3,4-tri-O-methyl-ß-D -glucopyranose with epichlorohydrin was studied. Structure and composition of the copolymers were determined by ¹H and ¹³C NMR spectroscopy, indicating that copolymerization occurred in each combination of monomers. Number-average molecular weights of copolymers were in the range of 1 400 to 22 800. From the specific rotation and ¹³C NMR spectrum of copolymers, it was revealed that the ring-opening copolymerization of the benzylated 1,6-anhydro-glucopyranose with the cyclic monomers occurred in a stereoregular manner to give the C-1 carbon of glucose unit with α-configuration. Debenzylation of a copolymer prepared from 1,6-anhydro-2,3,4-tri-Obenzyl-ß-D -glucopyranose and 1,3-dioxolane gave a copolymer composed of free sugar units in the polymer main chain. Assignment of ¹³C NMR spectra of 2,3,4-tri-O-benzyl-ß-D -glucopyranan and of a copolymer of 1,6-anhydro-2,3,4-tri-O-benzyl-ß-ß-glucopyranose with 1,3-dioxolane was attempted.     

Measurement of plasma von Willebrand factor cleaving protease in patients with varied thrombotic microangiopathy

Thrombotic thrombocytopenic purpura(TTP) is a multisystem disorders characterized by thrombocytopenia, microangiopathic hemolytic anemia associated with red cell fragmentation, and neurological and renal symptoms. Plasma of patients with TTP has been shown to contain unusually large von Willebrand factor(vWF) multimers that may cause platelet agglutination in vivo. Recently, a metalloprotease responsible for cleavage of vWF multimers has been isolated from normal human plasma and was found to be deficient in some patients with TTP. We examined the activity of the vWF-cleaving protease(vWF-CP), by modified Furlan's method, in plasma from patients with a familial TTP, 3 acquired TTP, 4 thrombotic microangiopathy(TMA) and 2 veno-occlusive disease(VOD) associated after allo-BMT. Diluted plasma samples of patients were incubated with protease-free vWF purified from normal human plasma, in the presence of urea and barium ions. The extent of vWF degradation was assayed by electrophoresis in SDS-agarose gels and immunoblotting. Activity of vWF-CP from 12 normal plasma have been shown as 77-180%(average 115%), whereas, no vWF-CP(below 5%) was observed in plasma from familial TTP, before and after plasma exchange, although FFP infusion therapy has been effective for this patient to recover thrombocytopenia. In 3 acquired TTP, 2 patients showed lack of vWF-CP activity in plasma, and inhibitors against vWF-CP have been elucidated by plasma cross-mixing test. After extensive plasma exchange and FFP infusion followed by corticosteroid therapy, normal vWF-CP was recovered in plasma from 2 acquired TTP patients. Among BMT patients, plasma from 4 BMT-TMA showed normal vWF-CP activities as 55-111%, whereas plasma from 2 BMT-VOD revealed low vWF-CP activity, as 24% and 37%, respectively. Thus, measurement of vWF-CP is crucial to predict differentiation of primary forms of TMA to establish the pathogenesis in varied endothelial dysfunction.     

A simple and rapid method for HLA-DP genotyping by digestion of PCR-amplified DNA with allele-specific restriction endonucleases

We previously reported a simple and rapid method for HLA-DQA genotyping by digestion of polymerase chain reaction-amplified DQA genes with allele-specific restriction endonucleases. Here we report the application of this method to DP genotyping. The second exon of the HLA-DPB genes was selectively amplified from genomic DNAs of 72 HLA-D homozygous B-cell lines by the polymerase chain reaction method. Amplified DNAs were digested with ApaI, SacI, BstUI, FokI, and RsaI, which can recognize allelic sequence variations in the polymorphic segments of the DPB second exon and then subjected to electrophoresis in polyacrylamide gels. Sixteen different polymorphic patterns of the restriction fragments were found, and twelve were identical to patterns predicted from the known DNA sequences correlating with each HLA-DPw specificity defined by cellular typing. The other four patterns were distinct from those of the known DPw specificities, suggesting the presence of novel DP alleles. This polymerase chain reaction-restriction fragment length polymorphism method provides a simple and rapid technique for accurate definition of HLA-DP types at the nucleotide level, replacing the technically demanding method of primed lymphocyte typing.     

Ramp rate of blood pressure changes does not affect aortic afferent sensitivity in anesthetized rats

To investigate whether the rate of change in blood pressure affects the sensitivity of the aortic baroreceptor afferent response, the change in aortic nerve activity (ANA) to two different rates of ramp increase in mean blood pressure (MBP), elicited by phenylephrine administration, was determined in the rat under urethane (1.5 g kg⁻¹) anesthesia. The sensitivity of the increase in ANA following a rapid (average ramp rate, 9.14 ± 0.60 mmHg s⁻¹, n = 11) or gradual (1.78 ± 0.24 mmHg s⁻¹, n = 11) increase in MBP was 2.03 ± 0.14% and 1.81 ± 0.20% of baseline mmHg⁻¹, respectively. These values were not significantly different from each other (P = 0.16). Furthermore, we found no correlation between the rate of ramp increase in MBP and the sensitivity of the increase in ANA (r = 0.24, P = 0.29, n = 22). These results suggest that, at least within the normal physiological range of MBP, the rate of the ramp change in blood pressure does not affect aortic baroreceptor afferent sensitivity in the anesthetized rat.     

Synthesis of 3-amino-ribofuranans having 1,5-α and -β structures by selective ring-opening polymerization of a 1,4-anhydro-3-azido-3-deoxy-α-D-ribopyranose derivative

Ring-opening polymerization of a new anhydro ribose-type monomer, 1,4-anhydro-3-azido-3-deoxy-2-O-tert-butyldimethylsilyl-α-D -ribopyranose (A3ASR), was investigated. The monomer was synthesized from 1,4-anhyro-α-D -xylopyranose by three steps comprising Walden inversion at the C3 position into ribose configuration. Ring-opening polymerization of A3ASR by Lewis acid catalysts such as boron trifluoride etherate and stannic chloride gave a stereoregular 3-azido-3-deoxy-2-O-tert-butyldimethylsilyl-(1→5)-α-D -ribofuranan having specific rotations of +246 ～ +271 deg · dm^?1 · g^?1 · cm³ and number-average molecular weights of 18,7 × 10³ ～ 25,1 × 10³. When the polymerization was carried out by antimony pentachloride at 0°C, the resulting polymer exhibited a negative specific rotation of ?6 deg · dm^?1 · g^?1 · cm³ and the C1 absorption in the ¹³C NMR spectrum shifted downfield to 107,5 ppm, suggesting that the polymer might consist of 1,5-β furanosidic unit. The reduction of the azido group of the 1,5-α and 1,5-β furanosidic polymers into amino group and subsequent desilylation gave 3-amino-3-deoxy-(1→5)-α- and -β-D -ribofuranans, respectively. In addition, copolymerization of A3ASR with 1,4-anhydro-2,3-di-O-tert-butyldimethylsilyl-α-D -ribopyranose (ADSR) in various feeds was performed by boron trifluoride etherate as catalyst to give copolymers with different monomeric components. The structural analysis of the homopolymers and copolymers was examined by means of ¹H and ¹³C NMR spectroscopies, IR spectroscopy, and optical rotation.