Amphotere ionenaustauscher (teil IV)

Polymer complexing agents containing methylphosphonic acid groups at the polyethyleneimine skeleton were synthesized by condensation of polyethyleneimine with formaldehyde and phosphorous acid. A new amphoteric ion exchanger of high mechanical and chemical stability was obtained by reaction of crosslinked polyethyleneimine with formaldehyde and phosphorous acid. The degree of substitution did not exceed 50% as well with a crosslinked as with the non-crosslinked polyethyleneimine. The ion exchange resins ability to bind Cu^2⊕, Zn^2⊕, Ni^2⊕, and Mg^2⊕ was investigated. The capacity for Cu^2⊕ at pH 6 was 6.0 m Val/g. The investigation of the swelling of the amphoteric ion exchanger at various pH values have shown that the swelling of the polymer depends only very little on the pH. The crosslinked polyethyleneimine was prepared by reaction with 1.4-Bis-(chloromethyl)-benzene. This crosslinked polyethyleneimine is a new weakly basic ion exchanger with good mechanical and chemical stability. The capacity for copper as well as the swelling properties were investigated at various pH.     

Über das schwermetallbindungsvermögen von vernetztem poly(vinylamin) und daraus hergestellter amphoterer ionenaustauscher

The possibility of binding the metal ions Cu⁺⁺, Ni⁺⁺, Co⁺⁺, Zn⁺⁺, and Mg⁺⁺ by poly-(vinylamin) crosslinked with hydrophilic hexa-1.5-dien-3.4-diol was studied in the pH range 3–8 as well as the kinetics of this process. By condensation of the amin resins with chloroacetate chelating resins with a high capacity were obtained. The introduction of the α-aminomethylphosphonic group into the amin resin by reaction with chloromethylphosphonate or formaldehyde and phosphorous acid resulted in new amphoteric resins. At different pH values for both types of resins the adsorption of transition metal ions and their exchange rate was measured.     

Saccharide Polymers, 5

Summary: New “saccharide polymers” were synthesized via free radical polymerization. The saccharide compounds in copolymerisation reactions were 2,4,6‐tri‐O‐acetyl‐3‐deoxy‐D ‐erythro‐hex‐2‐enono‐1,5‐lactone ( 1 ), (Ac‐GEL 1 ) and 2,4,6‐tri‐O‐benzoyl‐3‐deoxy‐D ‐erythro‐hex‐2‐enono‐1,5‐lactone ( 2 ), (Bz‐GEL 2 ). These sugar monomers are easily obtained with high yield in a one step reaction from glucono‐δ‐lactone. They have a pyranoid structure containing an endocyclic double bond and they are electron acceptor compounds. Copolymerization reactions were carried out in solution and in substance. Copolymers with different sugar contents and low as well as high molecular weights were obtained. The structures and the compositions of the soluble saccharide polymers were established by elemental analysis, polarimetry, FTIR spectroscopy, ¹H and ¹³C NMR spectroscopy. Some characteristic properties, e.g., molecular weight, optical rotation and copolymerization parameters are reported.

Schematic conversion of glucono‐δ‐lactone to saccharide monomers.     

Localization of 5-HT2A, 5-HT3, 5-HT5A and 5-HT7 receptor-like immunoreactivity in the rat cerebellum

Although serotonin (5-hydroxytryptamine, 5-HT) is known to exert a modulatory action on cerebellar function, our current knowledge of the nature of receptor subtypes mediating serotonergic activity in this part of the brain remains fragmentary. In this study, we report the presence and distribution of 5-HT3, 5-HT5A and 5-HT7 receptor-like immunoreactivity in the rat cerebellum using immunofluorescence histochemistry. 5-HT3 immunoreactivity was found in fibers sparsely distributed throughout the cerebellum. Most of them were seen in the cerebellar cortex as fine varicose 5-HT3-positive axonal processes. 5-HT5A immunoreactivity, on the other hand, was observed in neuronal somata of the cerebellar cortex and deep cerebellar nuclei. Based upon cell morphology and the use of cell-specific markers, Purkinje cells, molecular layer interneurons and Golgi cells were found to be 5-HT5A immunopositive. In addition, the use of cell-specific markers allowed us to identify previously reported large 5-HT2A-positive cells in the granular layer as being Golgi cells. Finally, 5-HT7 immunoreactivity was observed only in Purkinje cells. Corroborating previous radioligand-binding, in situ hybridization and immunohistochemical studies, our data relate serotonin receptor subtypes to specific cerebellar cell types and may consequently contribute to the elucidation of serotonergic actions in the cerebellum.     

5-HT4, 5-HT6, 5-HT7; molecular pharmacology of adenylate cyclase stimulating receptors

Throughout the nervous system the receptors for the neurotransmitter serotonin form an unusually diverse set. Receptor-mediated responses to serotonin utilize a large collection of biochemical second messenger pathways, such as the stimulation or inhibition of adenylate cyclase activity, the hydrolysis of phosphoinositides, the mobilization of calcium and direct gating of ion channels. This diversity of structure and activity has been substantiated by the application of molecular cloning techniques which have now yielded at least 15 distinct molecular entities. The most recent subset of receptors for serotonin to be cloned are those that couple to the stimulation of adenylate cyclase activity. These subtypes: 5-HT₄, 5-HT₆ and 5-HT₇, although sharing a common signal transduction pathway, are remarkably divergent in their amino acid sequences, distribution in the brain and pharmacological properties. This digression from the expected relationships of receptor subtypes based on other serotonin receptors, as well as other biogenic amino receptor families, is unexpected and raises many questions about the extreme diversity of this signaling system.     

LRP5, low-density-lipoprotein-receptor-related protein 5, is a determinant for bone mineral density

Osteoporosis is a multifactorial trait with low bone mineral density (BMD). We report results of an association study between BMD and nine candidate genes (TGFB1, TGFBR2, SMAD2, SMAD3, SMAD4, IFNB1, IFNAR1, FOS and LRP5), as well as of a case-control study of osteoporosis. Samples for the former association study included 481 general Japanese women. Among the nine candidate genes examined, only LRP5 showed a significant association with BMD. We identified a strong linkage disequilibrium (LD) block within LRP5. Of five LPR5 single nucleotide polymorphisms (SNPs) that are located in the LD block, three gave relatively significant results: Women with the C/C genotype at the c.2220C>T SNP site had higher adjusted BMD (AdjBMD) value compared to those with C/T and T/T (p=0.022); and likewise, G/G at IVS17–30G>A and C/C women at c.3989C>T showed higher AdjBMD than those with G/A or A/A (p=0.039) and with C/T or T/T (p=0.053), respectively. The case-control study in another series of samples consisting of 126 osteoporotic patients and 131 normal controls also gave a significant difference in allele frequency at c.2220C>T (²=6.737, p=0.009). These results suggest that LRP5 is a BMD determinant and also contributes to a risk of osteoporosis.     

Tryptophan, 5-HTP, 5-HT and 5-HIAA in the cerebrospinal fluid and sexual behavior in male rats

No changes were found in the concentration of tryptophan (Trp), 5-hydroxytryptophan (5-HTP), 5-hydroxytryptamine (5-HT) or 5-hydroxyindole acetic acid (5-HIAA) in the cerebrospinal fluid (CSF) of male rats either before sexual activity, immediately after ejaculation of after the postejaculatory refractory period (PEI). Injection of the Trp hydroxylase inhibitor p-chlorophenylalanine (PCPA, 25 or 100 mg/kg i.p. for 3 days) in combination with an injection of the monoamine oxidase inhibitor pargyline (100 mg/kg i.p.) increased the concentration of Trp while decreasing the concentration of 5-HTP, 5-HT and 5-HIAA in the CSF. Furthermore 100 (but not 25) mg/kg PCPA in combination with pargyline caused a significant reduction in the latency to ejaculation. Injection of probenecid (200 mg/kg i.p.), an inhibitor of the transport of 5-HIAA from the CSF, increased the concentration of 5-HIAA in the CSF and slightly prolonged the latency to ejaculation. Sexual activity caused no further increase in CSF 5-HIAA levels in the probenecid-treated rats. Since drug-induced changes in sexual behavior are associated with marked alterations in 5-HT metabolism in the CSF, whereas the changes in the behavior which occur normally are not, these results question the physiological significance of the proposed inhibitory role of 5-HT in male rat sexual behavior.     

46，XY,-5，＋der（5p＋）mat一例

患儿　男性,年龄15天。因多发畸形,特异脸形,哭声似猫叫就诊。患儿出生体重2 .6kg ,小头圆脸,两眼眼距宽、下斜、内眦赘皮。两侧耳低位,前缘均有3个小赘生物生长,对称。两手通贯掌,两小手指均为两节指骨。两足足底呈舟状足。外生殖器检查:双侧均为隐睾,未探及睾丸。阴茎极短小( <0 .3cm)。哭声轻,酷似“猫叫”。呼吸音粗而急,心脏可闻及胸骨左缘收缩期杂音Ⅲ级,粗糙杂音,唇周紫绀。经上海市儿童医院心脏彩超检查,诊断为“法乐氏四联症”先天性心脏病。一家3人在本中心细胞遗传学检查,经外周血淋巴细胞培养,G带显带,染色体核型分析:患儿为46…