Interaction of a Neutral Endopeptidase Inhibitor with an ANP-C Receptor Ligand in Anesthetized Dogs

Inhibition of important degradative pathways of atrial natriuretic peptide (ANP) in vivo could be a valuable therapeutic tool for regulating endogenous levels of ANP. The aim was to investigate the in vivo effects of both blockade of atrial natriuretic peptide clearance receptor and inhibition of neutral endopeptidase 24.11, an enzyme shown to be involved in ANP breakdown. Therefore, we infused a specific neutral endopeptidase inhibitor ((S)-thiorphan) and an ANP-C receptor ligand (AP 811) alone or in combination into anaesthetized beagle dogs.

Compared with vehicle controls, coadministration of (S)-thiorphan and AP 811 (100μg/kg/min and 10μg/kg/min, resp.) had greater effects on endocrine and renal parameters than administration of either substance alone.     

Vitamin K supplementation does not significantly impact bone mineral density and biochemical markers of bone in pre- and perimenopausal women

Because of its role in osteoblastic metabolism, vitamin K has been studied with respect to bone. However, there has been limited research examining the influence of long-term vitamin K supplementation on bone mineral density (BMD). Therefore, the purpose of this study was to assess the impact of 6 months of vitamin K supplementation on BMD and biomarkers of bone in pre- and perimenopausal women. Based on previous work, we hypothesized that vitamin K would improve BMD and biochemical markers of bone formation. A double-blind, placebo-controlled, randomized trial is an effective way to study the impact of long-term supplementation. Thus, 14 pre- and perimenopausal women, 25 to 50 years of age, were randomly assigned to an experimental group (E) that received 600 μg/d of vitamin K in the form of phylloquinone (K₁) or a control group (C) that received identical-looking placebo tablets. Regional BMD and percent body fat, measured by dual-energy x-ray absorptiometry, and serum osteocalcin and urinary N-telopeptide levels were all assessed at 0, 3, and 6 months. When BMD was measured across time, C had a significant increase (P = .011) in greater trochanter BMD compared to E. The E group had a nonsignificant increase (P = .067) in shaft BMD compared to the C group. There was no significant difference between E and C in serum osteocalcin concentrations over time. Urinary N-telopeptide levels increased significantly over time in E compared to C (P = .008). Six months of 600 μg/d vitamin K₁ supplementation did not improve regional BMD in this group of pre- and perimenopausal women.     

13,14双氢15-酮基前列腺素F_(2α)放射免疫测定法和初步应用

采用日本大耳白家免获得了亲和力高,特异性强的13,14-双氢15-酮基前列腺素F_(2α)(PGF_(2α)M)抗血清,建成了灵敏、精确、操作简便的PGF_(2α)M放射免疫测定法(RIA)。测定了人和动物血浆和尿样的正常值,同时观察了醋酸棉酚对大鼠血浆和尿中PGF_(2α)M含量的影响以及妇女月经周期中血浆PGF_(2α)M含量的变化。     

Distribution and quantification of corticotropin-releasing hormone (CRH) in the brain of the teleost fish Oreochromis mossambicus (tilapia)

The recent characterization of the corticotropin-releasing hormone (CRH) prehormone of the fish tilapia (Oreochromis mossambicus) showed that more variation exists between vertebrate CRH amino acid sequences than recognized before. The present study investigates whether the deviating composition of tilapia CRH coincides with an atypical distribution of CRH in the brain. For this purpose we applied immunohistochemistry, as well as radioimmunoassay (RIA) quantification in brain slices. The results are plotted in a new atlas and reconstruction of the tilapia brain. The largest population of CRH-immunoreactive (ir) neurons is present in the lateral part of the ventral telencephalon (Vl). Approximately tenfold less CRH-ir neurons are observed in the preoptic and tuberal region. The CRH-ir neurons observed in the preoptic region are parvocellular and do not, or hardly, display arginine-vasotocin (AVT) immunoreactivity. CRH-ir neurons are also present in the glomerular layer of the olfactory bulb, in the periventricular layer of the optic tectum, and caudal to the glomerular nucleus. A very dense plexus of CRH-ir terminals is located in the most rostral part of the dorsal telencephalon. This region has not been described in other teleosts and is in the present study subdivided into the anterior part of the dorsal telencephalon (Da) and the anterior part of the laterodorsal telencephalon (Dla). High densities of CRH-ir terminals were observed in and around Vl, in the tuberal region, around the rostral part of the lateral recess, and in the caudal part of the vagal lobe. In the pituitary, CRH-ir terminals are concentrated in the neuro-intermediate lobe. Overall, the immunohistochemical and quantitative data correlated well, as the RIA CRH profile in serial 160-microm slices revealed four peaks, which corresponded with major ir-cell groups and terminal fields. Our results strongly suggest that the CRH-ir cells of Vl project to the rostro-dorsal telencephalon. Consequently, they may not be primarily involved in regulation of pituitary cell types but may subserve other functions. The presence of a CRH-containing Vl-Da/Dla projection seems to be restricted to the most modern group of teleosts, i.e., the Acanthopterygians. Further anatomic indications for non-pituitary-related functions of CRH are found in the vagal lobe and the optic tectum of tilapia. Although the low CRH content of the preoptic region reported here for tilapia may be typical for unstressed fish, the fact remains that remarkably few CRH-ir neurons are involved in regulating the pituitary. Overall, the CRH distribution in the brain of tilapia is more widespread than previously reported for other teleosts.     

Tissue distribution of human calcium-binding protein (28 000 g mol-1)

Immunoreactive calcium-binding protein (28 000 g mol-1, L-CaBP) has been quantified using a specific radioimmunoassay to human cerebellar L-CaBP. The level of L-CaBP in post-mortem tissue samples varied from undetectable in muscle to 8 micrograms/mg-1 protein in the cerebellum and 16 micrograms mg-1 protein in the dentate nucleus. L-CaBP was found to be widely distributed throughout the nervous system while the only non-nervous tissue which contained appreciable levels was the renal cortex.     

Development of Bile Acid Metabolism in Neonates during Perinatal Period | Part 2. Mass screening of congenital biliary atresia by radioimmunoassay using dried blood spot

Inour country, congenital biliary atresia (CBA) has occurred in approximately 1 of 10,000 live births, but its prognosis has been extremely poor. In the mass screening of this disease, glycocholic acid (GCA) or chenodeoxycholic acid (CDCA) level in dried blood spots on filter paper in5-day-old neonates was determined by radioimmunoassay (RIA).
To determine GCA in dried blood spots on filter paper, the procedures in this experiment were modified using commercial kit for serum.
The mean GCA level of controls (n=391) was 5.88±4.28 nM/ml and that of CBA (n=22) was 14.1 ±3.1 nM/ml. On the other hand the mean CDCA level of controls (n=86) was 5.86 ±3.07 pM/l disc that of CBA (n=22) was 30.0 ±35.9 pM/l disc. When the criterion is assumed to be more than 16 nM/ml of GCA level or 10 pM/l disc of CDCA level, false negative diagnoses of CBA are 31.8% and 18.2% respectively. On the other hand false positive diagnoses of CBA are 6.9% and 3.5% respectively. It was thought that false negative diagnosis on mass screening with GCA level would decrease using fresh dried blood spot within 2 weeks after taking blood.
In 22 CBA cases, the GCA levels in dried blood spots on filter paper were not always parallel with the CDCA levels.     

Enzyme-linked immunosorbent assay of substance P and its metabolite SP 1-7. A comparison with RIA

We have investigated enzyme-linked immunosorbent assay (ELISA) as a possible alternative to radioimmunoassay (RIA) for the detection and measurement of the neuropeptide substance P (SP) and its metabolite substance P1-7. The sensitivities were higher with ELISA than with RIA utilizing the same antisera. The intra-assay and inter-assay variation in ELISA was 1% and 13% respectively. The higher sensitivities are in part due to the standard curves having less steep slopes, and in part to lower IC50s in the ELISA. Since there was a good correlation between peptide levels in biological samples as determined by ELISA and RIA respectively, ELISA might be considered an attractive alternative to RIA.     

胰岛素样生长因子-Ⅰ、瘦素与Graves病相关性研究

目的 探讨血清胰岛素样生长因子-Ⅰ(IGF-Ⅰ)、瘦素(Leptin)及BMI在Graves病(GD)中的改变及其相互关系.方法 采用放射免疫分析法(RIA)检测55例(男15例,女性40例)患者从初发病到治疗稳定、停药复发血清IGF-Ⅰ、Leptin水平,并与年龄和性别相匹配的健康人(对照组)比较.结果 初发组血清IGF-Ⅰ水平升高明显,与对照组比较差异均有显著性(P＜0.01);停药后复发组血清Leptin水平下降,差异有显著性(P＜0.05).结论 IGF-Ⅰ、Leptin与自身免疫性疾病GD的发病有关.     

应用RIA技术构建医学形态学网络图像资源库的研究

在介绍R IA技术的概念、特点以及技术平台的基础上,指出网络上流行的医学形态学图像资源库的现状,同时分析了应用RIA技术所构建的新型医学形态学网络图像资源库的组织结构、功能特点及其意义。     

糖尿病酮症酸中毒治疗前后的甲状腺激素变化

测定６５例糖尿病酮症酸中毒患者治疗前及治疗后１周、２周甲状腺激素；同时测定糖尿病控制组（对照组）甲状腺激素。结果：糖尿病酮症酸中毒治疗前血清ｒＴ３明显高，Ｔ３、ＦＴ３明显低，Ｔ４、ＦＴ４无明显变化。随病情好转，各项指标逐渐恢复，２周后甲状腺激素恢复至糖尿病控制组水平。说明甲状腺激素变化与糖尿病酮症酸中毒病情轻重有关。