Evidence against the involvement of serotonergic neurons in the anti-punishment activity of diazepam in the rat

The effects of manipulating central serotonergic transmission were assessed on the anti-punishment effects of diazepam (2 mg/kg IP) in rats. In a paradigm involving the inhibition of pressing for food induced by the delivery of a signal previously associated with electric foot-shocks, lesioning serotonergic neurons of the dorsal raphé with the neurotoxin 5,7-dihydroxytryptamine (5,7-DHT; 1 g in 0.4 l) neither affected behavioral inhibition in control rats nor modified the ability of diazepam to release responding. Furthermore, suppression of pressing for food induced by a fixed ratio 7 schedule of shock presentation was reduced by bilateral infusion of 5,7-DHT (2 g in 0.5 l) into the substantia nigra, but the ability of diazepam to increase punished responding was preserved. Finally, blockade of benzodiazepine-induced decrease in serotonin release by application of the benzodiazepine receptor antagonist Ro 15-1788 (10^–5–10^–4 M in 0.2 l) into the dorsal raphé did not alter the releasing effect of diazepam on suppression of pressing for food caused by a signal of punishment. At these concentrations. Ro 15-1788 was devoid of any effect on behavioral inhibition in control rats. Taken together, these results indicate that the anti-punishment activity of benzodiazepines can be dissociated from the reduction in tryptaminergic transmission produced by these drugs.     

Iodine-123-labelled fatty acids for myocardial single-photon emission tomography: current status and future perspectives

Renewed interest in the clinical use of iodine-123-labelled fatty acids is currently primarily focused on the use of iodine-123-labelled 15-(p-iodophenyl)pentadecanoic acid (IPPA) and modified fatty acid analogues such as 15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP) which show delayed myocardial clearance, thus permitting single-photon emission tomographic imaging. Interest in the use of BMIPP and similar agents results from the differences which have often been observed in various types of heart disease between regional myocardial uptake patterns of [¹²³I]BMIPP and flow tracer distribution. Although the physiological basis is not completely understood, differences between regional fatty acid and flow tracer distribution may reflect alterations in important parameters of metabolism which can be useful for patient management or therapy planning. These tracers may also represent unique metabolic probes for correlation of energy substrate metabolism with regional myocardial viability. The two agents currently most widely used clinically are¹²³I-labelled IPPA and BMIPP. While [¹²³I]IPPA is commercially available as a radiopharmaceutical in Europe (Cygne) and Canada (Nordion), multicenter trials are in progress in the United States as a prelude to approval for broad use. [¹²³I]BMIPP was recently introduced as Cardiodine for commercial distribution in Japan (Nihon Medi-Physics, Inc.). [¹²³I]BMIPP is also being used in clinical studies on an institutional approval basis at several institutions in Europe and the United States. In this review, the development of a variety of radioiodinated fatty acids is discussed. The results of clinical trials with [¹²³I]IPPA and [¹²³I]BMIPP are discussed in detail, as are the future prospects for fatty acid imaging.     

Production of 5–15 µm Diameter Alginate-Polylysine Microcapsules by an Air-Atomization Technique

A novel method of preparing small-sized microcapsules using a Turbotak air-atomizer is reported. Alginate-polylysine microcapsules containing Bacillus Calmette Guérin vaccine have been prepared by an adaptation of the method of Lim (1) which allows the manufacture of small-sized microcapsules. A Turbotak is used to spray sodium alginate solution into calcium chloride solution to form temporary calcium alginate microgel capsules. These temporary microgel droplets are subsequently cross-linked with polylysine to form permanent membranes. Microcapules in the size range of 5–15 µm have been produced which can be compared to an average diameter of 300 µm obtained by the method reported by Lim. The microcapsule size is dependent on the conditions of operation of the Turbotak and the concentration of the sodium alginate solution. Particles within the size range 5–15 µm can be reproducibly manufactured using the conditions of operation reported here. Other size ranges below the minimum of 300 µm reported by Lim are also feasible using this technique.     

Evaluation of cellular viability by quantitative autoradiographic study of myocardial uptake of a fatty acid analogue in isoproterenol-induced focal rat heart necrosis

Previous studies led us to hypothesize that a fatty acid analogue, 15-p-iodophenyl--methyl pentadecanoic acid (IMPPA or BMIPP), which is taken up but not quickly metabolized by heart cells, would be a more suitable tracer of cellular viability than thallium-201. Biodistribution studies of 1-¹⁴C-IMPPA in conscious, freely moving rats showed that the concentration ratio of radioactivity in the heart with respect to the blood was about 8 for at least 60 min after intravenous administration, permitting its use as a putative tracer in these conscious, freely moving rats. Thereafter, the myocardial uptake of¹⁴C-IMPPA was studied in isoproterenol-treated rats (daily treatment for 10 days in order to induce cardiac hypertrophy and necrotic foci) with respect to control ones. Comparison of myocardial localizations by quantitative autoradiography of the uptake of²⁰¹Tl and¹⁴C-IMPPA with that of triphenyltetrazolium chloride (TTC) staining enabled comparative evaluation of nutritional blood flow, localization and uptake of¹⁴C-IMPPA and necrotic foci size. Distributions of¹⁴C-IMPPA and²⁰¹1 T1 in control rats' hearts were homogeneous, like TTC staining. In infarcted hearts, areas of decreased¹⁴C-IMPPA uptake were nearly the same (100%±5%) as those unstained by TTC. These areas were larger than those showing a decrease in thallium uptake (about 70%±5% of the total scar size). Therefore, IMPPA seems to be a more accurate and sensitive indicator of necrosis localization compared with thallium. It may be a useful agent for assessment of myocardial viability by single photon emission tomography (SPET) imaging.     

Synthesis and physico‐chemical properties of peptides in soil humic substances

Abstract: Soil humic substances (HS) are heterologous, polydispersive, and multi‐functional organometallic macromolecules ubiquitous in soils and sediments. They are key players in the maintenance of the belowground ecosystems and in the bioavailability of both organic and inorganic contaminants. It is widely assumed that the peptidic substructures of HS are readily degraded and therefore do not contribute significantly to interactions with contaminants such as toxic metals. To investigate the turnover of humified peptides, laboratory soil aging experiments were conducted with ¹³C‐glucose or ¹⁵N‐nitrate for 8.5 months. Evidence for random‐coil peptidic structures in the labeled HS was obtained from 2‐D nuclear magnetic resonance (NMR), pyrolysis gas chromatography‐mass spectrometry (pyro‐GC‐MS), and circular dichroism data. Interaction of metals with the peptidic carbonyls of labeled HS was rationalized from the solid‐state NMR data. Detailed ¹³C and ¹⁵N labeling patterns of amino acid residues in the acid hydrolysates of HS acquired from NMR and GC‐MS revealed two pools of peptides, i.e. one extant (unlabeled) and the other, newly humified with little isotopic scrambling (fully labeled). The persistence of pre‐existing peptidic structures indicates their resistance to degradation while the presence of fully labeled peptidic amino acids suggests wholesale incorporation of newly synthesized peptides into HS. These findings are contrary to the general notion that humified peptides are readily degraded.     

Unusual features in children with inv dup(15) supernumerary marker: a study of genotype-phenotype correlation in Taiwan

Recent molecular cytogenetic studies have elucidated the origin and nature of extra structurally abnormal chromosomes (ESACs) or small supernumerary chromosomes, which are often associated with developmental delay and malformations. We studied the prevalence of inv dup(15) in a nationwide screening programme for mentally retarded children in Taiwan and tried to correlate the genotype and phenotype in those patients. Fluorescence in situ hybridization (FISH) analysis using D15Z, D15Z1, and the cosmids from the Prader-Willi/Angelman syndrome chromosome region (PW/ASCR) was performed on 54 patients (0.45%) with ESACs from 11893 probands within a 5-year period. Of them, inv dup(15) was confirmed in 25 children (46.3%) by FISH analysis. The PW/ASCR probes were used to clarify the size and DNA composition of the markers. Patients with inv dup(15) chromosomes, containing only the heterochromatin or little euchromatin of the proximal 15q (i.e., pter→q11:q11→pter) may have a rather mild or nearly normal phenotype (group 1). Only one patient had some features suggestive of Angelman syndrome, but was considered to be a result of deleted (15)(q12) in the chromosome 15 homologue. Additional copies within D15S11 through GABRB3 (15q11.2-13) resulted in an abnormal phenotype which involved mental and developmental delay but was different from the classical phenotype of PW/AS (groups 2, 3). Signs of autistic behavior did occur in each group. FISH combined with microsatellite analyses showed that the marker was often of maternal origin in de novo cases (n = 12, 86%), or inherited from the mother in only one familial case. Down-inv dup(15) was mentioned in two cases. Unusual features including diaphragmatic eventration, hyperlaxity of joints, arachnodactyly, brain atrophy, epilepsy (particularly infantile spasm), ataxia, genital abnormalities, and cleft lip/palate were noted in those patients. This observation expands the range of phenotypic expression associated with this relatively common ESAC. Conclusion Marked phenotypic diversities exist in children with inv dup(15), dependent upon the size or genetic composition of the markers, degree of mosaicism, parental origin and familial occurrence or not. Patients with a larger inv dup(15) marker chromosome including the PW/ASCR may have a higher risk of abnormalities, but not the typical Prade-Willi/Angelman syndrome phenotype. Received: 11 February 1997 and in revised form: 20 May 1997 / Accepted: 20 May 1997     

IL-15对儿童MDS造血前体细胞bcl-2、bcl-xl mRNA表达的影响

目的 探讨IL-15对骨髓增生异常综合征(MDS)造血细胞bcl-2、bcl—xl mRNA表达的影响，以探索IL-15抑制MDS CD34^ 造血干／祖细胞凋亡的可能机制：方法 采用吸附单克隆抗体的免疫磁珠分离系统，分离纯化17例MDS患儿骨髓CD34^ 细胞，采用RT—PCR检测bcl-2、bcl—xl mRNA表达水平，观察IL-15对它们的影响。结果 IL-15可呈时间与剂量依赖性的增强体外培养的MDS造血前体细胞bcl-2、bcl—xl基因mRNA的表达。结论 IL-15可能为抑制MDS CD34^ 造血干／祖细胞凋亡的作用机制之一。     

超声引导下不同部位中心静脉置管在婴幼儿休克中的应用及临床分析

目的分析超声引导下不同部位中心静脉置管在婴幼儿休克中应用的临床特点，探讨在婴幼儿休克中应如何快速选择中心静脉置管部位。方法回顾性收集2016年1月至2020年12月广东医科大学附属东莞儿童医院儿童重症监护室收治的112例诊断为休克并进行中心静脉置管的婴幼儿临床资料，根据是否在超声引导下进行置管分为超声组（70例）及体表定位组（42例），总结分析患儿在超声引导下不同部位置管的应用情况，对各部位置管的一针成功率、总成功率、置管时间及并发症进行比较。结果与体表定位组相比，超声组颈内静脉及股静脉置管的一针成功率增高，置管时间缩短，并发症发生率减少（P<0.05）。超声组中，行颈内静脉置管比例最高（51%，36/70），其次为股静脉（33%，23/70），锁骨下静脉最少（16%，11/70）。超声引导下不同置管部位比较，颈内静脉成功置管时间最短［5.5（5.0，6.5）min］（P<0.05）；不同置管部位的并发症发生率比较差异无统计学意义（P>0.05）。结论在婴幼儿休克状态下，应用超声引导下行颈内静脉置管可作为临床医生优先选择的置管方式。     

Study on Hot Deformation Behavior of an Antibacterial 50Cr15MoVCu Tool Steel

Hot deformation behaviors of an antibacterial 50Cr15MoVCu tool steel were studied. The flow stress curves presented three typical characteristics: (i) a single peak dynamic recrystallization curve, (ii) a monotone incremental work-hardening curve, and (iii) the equilibrium dynamic recovery curve. The flow stress increased with the increase of the deformation rate at each deformation temperature and decreased with the increase of the deformation temperature at the same deformation rate. The thermal activation energy and material constants were Q of 461.6574 kJ/mol, A of 3.42 × 10¹⁷, and α of 0.00681 MPa⁻¹, respectively. The high temperature constitutive equation was: Z=ε˙expQ/RT=3.42×1017sinh0.0068×σ5.6807. Based on the processing maps and microstructure evolution, the best hot working process was a deformation temperature of 1050 °C and deformation rate of 0.001 s⁻¹.