Effect of posterior pituitary lobectomy on in vivo and in vitro secretion of prolactin in lactating rats

The effect of removing the posterior and neuro-intermediate lobes (PLX) of the pituitary gland of lactating rats was determined on both suckling-induced release and transformation of prolactin (PRL), and on regionalization of PRL release. Sixteen hours, or 1 or 4 d after either PLX or sham surgery, acute (15-min) suckling was applied. Also, regionalization of PRL release was analyzed by incubating the central and peripheral regions of APs from nonsuckled rats. Plasma PRL was analyzed by radioimmunoanalysis (RIA), whereas anterior pituitary (AP) PRL content and in vitro released PRL were determined by polyacrylamide gel electrophoresis. Plasma PRL increased 25- to 30-fold after suckling in intact and sham, and 10- to 15-fold in 1- and 4-d PLX rats, but no change occurred on either 16-h PLX nonsuckled and suckled rats. Also, PRL transformation occurred in intact, sham, and 4-d PLX suckled rats, but not in 16-h sham, or in 16-h and 1-d PLX suckled rats. Finally, the higher secretion of PRL shown in vitro by the central region of APs from intact and sham was not observed in APs from PLX rats. These results show that PLX transiently depresses the suckling-regulated PRL transformation and release. Likewise, influences from the posterior and/or neuro-intermediate lobes may determine regionalization of PRL release.     

The regionalization of [H]dihydrotetrabenazine binding sites in the mouse brain and its relationship to the distribution of monoamines and their metabolites

[³H]Dihydrotetrabenazine binding was measured in 8 areas of the mouse brain. In all areas, binding occurred on a homogeneous class of sites (K_d 2.6nM). The density of [³H]dihydrotetrabenazine binding sites strongly varied between the different brain structures; it was compared to endogenous levels of biogenic monoamines and their metabolites: the density is independent of the nature of the monoamine and of neuronal activity, but is highly correlated to the total amount of monoamines present in each structure.     

我国地黄人工种植生态适宜性区划研究

目的进行地黄的生态适宜性区划,为地黄人工种植基地选取和优质工业原料收购区域的确定提供依据。方法以全国740个气象站点、1971—2001年的气象数据为基础,采用“模板模式”,应用相似度分析、德尔菲法和空间分析方法进行地黄种植气候适宜性等级划分;以气候适宜性等级划分结果和中国土壤图栅格数据为基础,应用ArcGIS软件进行空间叠加和空间计算,进行地黄的生态适宜性区划。结果地黄最适宜区主要集中在河南北部,以及与河南北部接壤的山西、河北南部,山东西南部和安徽北部地区。新疆以及甘肃的部分地区也有适宜地黄栽培的气候条件。结论应用空间分析技术,从气候和土壤两个方面,进行地黄的生态适宜性区划研究,可以为地黄人工种植基地选取和优质工业原料收购区域的确定提供依据。     

基于气候因子的白术生态适宜性区划研究

通过对白术中白术内酯类成分含量与气候因子之间的相关性研究,对白术在全国主产区5省份的气候适宜性进行区划研究,为开展白术种植的合理区域选取提供科学的依据。在对全国5省份40个产地白术实地采样的基础上,应用统计分析方法,全面分析了不同气候因子条件下白术内酯类成分含量的变异,及各气候因子对白术内酯类成分含量的影响。并应用空间技术,依据白术内酯类成分含量与气候因子之间的关系,进行了基于气候因子的白术生态适宜性区划。最适宜白术内酯类成分积累的气候条件为:最湿月降水量(220~230 mm)、最暖季平均温(25℃以下)、最干季平均温(大于10℃)。     

Localization of latexin-immunoreactive neurons in the adult cat cerebral cortex and claustrum/endopiriform formation

The distribution of neurons that are immunoreactive to latexin, which is an endogenous inhibitor of the A/B subfamily of metallocarboxypeptidases, was investigated in the adult cat telencephalon. Latexin-immunoreactive neurons were distributed in the lower layers of the neocortex and adjacent ventral mesocortex, as well as in the claustrum/endopiriform formation. There were marked regional and laminar differences in density and distribution of latexin-immunoreactive neurons in the cerebral cortex. The density followed a roughly lateral-to-medial decreasing gradient: it was high in lateral cortical regions, which included the insular, second somatosensory, and anterior sylvian areas, and in the temporal auditory field; moderate in laterodorsal cortical regions, which included the primary and second auditory fields; and low in dorsal cortical regions, which included visual areas 18 and 19. Latexin-immunoreactive neurons were absent in medial cortical regions, which included the motor, premotor, prefrontal, prelimbic, cingulate, and retrosplenial areas. The lateral-to-medial gradient was apparent even within a single cytoarchitectonic area in certain cortical regions. The allocortex was devoid of latexin-immunoreactive neurons, with the exception of the anteroventral part of the dentate gyrus. The majority of cortical latexin-immunoreactive neurons were localized in layers V and VI and appeared to correspond to the “modified pyramidal cells in the infragranular layers.” The remaining latexin-immunoreactive neurons were localized in layer IV, as well as in lower layer III and in the white matter. There were no latexin-immunoreactive neurons from layer I through upper layer III. Latexin-immunoreactive neurons were present in telencephalic structures outside the cerebral cortex, with particularly high density in the claustrum/endopiriform formation. All these features, with the exception of that detected in the archicortex, are compatible with the features observed previously in the rat telencephalon. The similar pattern of distribution of latexin-immunoreactive neurons in several mammalian species from different orders suggests that latexin plays an important role in a specific cortical network.     

应用模糊数学方法进行黄连引种适栽区划的研究

本文应用的模糊数学方法，选择与黄连生物学特性有较大关系的气候生态因子，对我国黄连引种栽培提出适栽区别，以减少黄连等药用植物的盲目引种。     

Use of High-Technology Care Among Women with High-Risk Pregnancies in the United States

Objective: Infant mortality has been reduced dramatically with the development of perinatal regionalized high-technology care. Our objective was to assess use of high technology care among women with high-risk pregnancies in the urban and rural United States. Methods: The 1988 National Maternal and Infant Health Survey was linked to the 1988 American Hospital Association survey of all obstetrical hospitals. Hospitals were classified into five levels of care based on services and staffing. Women were classified as having high-risk pregnancies using two definitions: (1) gestational age <34 weeks and birthweight <1500 g (High Risk I) and (2) the first definition or an antenatal high-risk medical diagnoses (High Risk II). Analyses assessed the proportion of high-risk women delivering in appropriate locations in the rural and urban United States and explored how personal characteristics, insurance status, and use and source of prenatal care influenced where high-risk women delivered. Results: 71.2% of High Risk I and 55.9% of High Risk II women delivered in a high-technology facility (Level IIA or III). Fifty percent of HRI rural women delivered in tertiary high-technology hospitals and 39% of HRII rural women delivered in a high-technology hospital. High-risk urban women were two to three times more likely to deliver in a high-technology facility compared to their rural counterparts. The multivariate analysis showed that Black high-risk women were more likely to deliver in a high-technology setting and that receipt of prenatal care in a private setting lowered the odds of delivering in a high-technology setting when other factors were controlled. Conclusions: In an era where regionalized perinatal care was not threatened by managed care, a large proportion of high-risk women received care in less than optimal settings. Rural high-risk women delivered in high-technology hospitals less often than their urban counterparts. The multivariate analyses implied that the potential barriers to care may be more important among those considered more socially advantaged, who may be more at the mercy of managed care. The current reimbursement environment, which discourages referral to specialists and high-technology care, could result in less access today.