Fetal thermal dose considerations during the obstetrician's watch: Implications for the pediatrician's observations

There are a number of seemingly "usual" thermal episodes during pregnancy for which it is relatively easy to determine a rudimentary aspect of thermal dose; these episodes include fever, labor, labor plus epidural, and the normally-occurring 0.5 degrees C temperature elevation above maternal core temperature of the fetus during the entirety of the third trimester. Complications can involve, for instance, fever during the third trimester. We consider the thermal doses of five different but "usual" or "normal" hyperthermic episodes during human pregnancy and compare those doses with the thermal doses involved with both single and cohort exposures of pregnant guinea pigs throughout their gestational period. The end-point studied in the guinea pigs was microencephaly. In nine of the 10 comparisons (human fetal thermal dose vs. guinea pig fetal thermal dose) the human dose is substantially larger than that of the guinea pig thermal dose, which was substantially teratogenic. This situation is essentially the inverse of the type of information contained in the Physician's Desk Reference (PDR) on drugs, in which it is not unusual to discern that at high drug levels there may be teratogenic effects in laboratory animals, but such effects were not observed at "clinical" drug levels in animals or subsequent clinical trials. With hyperthermic events, however, it appears that the teratogenically-effective thermal dose levels associated with animal testing are quite low relative to those thermal doses associated with relatively "normal" obstetric observations during a pregnancy.     

新产程标准对产程中临床指征及母婴预后的影响

目的:探究新产程标准对产程中临床指征及母婴预后的影响。方法:选择2015年1月~2016年1月于我院妇产科分娩的产妇186例,其中101例采用旧产程标准的产妇为对照组,85例采用新产程标准的产妇为观察组。比较两组产妇产程中各项临床指征、产妇妊娠并发症、妊娠结局、新生儿围产结局。结果:观察组剖宫产率、催产素使用例数、产钳助娩干预显著低于对照组(P0.05);观察组产妇第一产程时间、第二产程时间均明显长于对照组(P0.05),两组活跃期时间、生产过程出血量比较差异无统计学意义(P0.05);两组产妇均未发生母婴不良结局事件。观察组和对照组胎膜早破、脐带扭转、羊水过少、产后出血等妊娠并发症的发生率比较差异无统计学意义(P0.05);两组新生儿在体重、宫内窘迫,窒息发生率、转入新生儿重症监护室(NICU)的比例等方面比较差异均无统计学差异(P0.05)。结论:新产程标准的应用延长了产程时限,给予产妇充分试产的机会,能够有效降低剖宫产率,减少产时过度干预。     

The effects of methyl palmitate,a putative regulator from perivascular fat,on the contractility of pregnant human myometrium

Aims

Methyl palmitate is thought to cause relaxation in vascular smooth muscle by opening voltage-activated potassium channels. We have tested the hypothesis that methyl palmitate, a putative regulator from perivascular fat, is an inhibitor of the contractility of human pregnant myometrium and that its effects might partially explain the higher incidence of dysfunctional labor in obese women compared to those with normal body mass indices.

Main methods

Strips of myometrium obtained with informed consent from women undergoing elective cesarean section at term were mounted in organ baths. Strips stimulated with oxytocin (1 nM) or KCl (30 mM) were exposed to cumulatively increasing concentrations of methyl palmitate up to 10 μM. Similar strips were exposed to cumulative addition of the potassium channel blockers 4-aminopyridine and tetraethylammonium. The contractility of the strips was monitored and analyzed using conventional methods.

Key findings

Methyl palmitate failed to inhibit oxytocin- or KCl-induced contractions over the concentration range tested. In fact, it exerted a slight excitatory effect in the presence of KCl, though not in the presence of oxytocin. The contractility of naïve strips was unaltered by exposure to 1 μM methyl palmitate. Both 4-aminopyridine and tetraethylammonium produced concentration-dependent contractions of human pregnant myometrium providing pharmacological evidence for the presence of voltage-activated potassium channels in this preparation.

Significance

Our findings do not support the hypothesis that methyl palmitate is an inhibitor of human pregnant myometrial contractility. Alternate hypotheses must be pursued to explain the higher incidence of dysfunctional labor in obese women.     

Behavioral flexibility in age castes of the antPheidole dentata

Division of labor among size and age classes in social insect colonies is a fundamental aspect of sociality, with such classes typically showing behavioral specialization and being associated with particular tasks for prolonged periods of time (i.e., forming castes). Theoretically, such specialization and division of labor enhance efficiency and, ultimately, reproductive success, and the ratios among members of those castes are hypothesized to be under selection and adaptive. However, our recent field study of the ant Pheidole dentatashowed no correlation between ecological factors which should affect colony growth and those caste ratios but implied flexibility in the association between minor worker age castes and their tasks. In laboratory experiments on behavioral flexibility in minor age castes of P. dentataold workers in colonies without young workers competently perform both old worker (castetypical) and young worker (atypical) tasks, and vice versa. The implications of these results for ergonomie theory are considered.     

Labor Productivity and Agricultural Development: Boserup Revisited

Labor productivity is a major component of agricultural development. Boserup is the scholar most associated with the view that labor productivity declines with intensification of agriculture. This paper reviews the theoretical argument and empirical support for the decline thesis. An empirical test is conducted by means of a comparative study of traditional rice agriculture in Southeast Asia. The decline thesis is rejected. The implications for agricultural development are discussed.     

The Low-Wage Conservationist: Biodiversity and Perversities of Value in Madagascar

ABSTRACT   In the early 1990s, donors began to implement "integrated conservation and development projects" (ICDPs) in Madagascar to stem deforestation, develop ecotourism, and promote forest conservation practices in rural areas. ICDPs recruited agrarian labor to groom and police parks and disseminate rules. In this article, I present a Marxian analysis of biodiversity's value in the global north, focusing on the role of manual workers in a Biosphere Reserve. I argue that ICDP's reliance on cheap local labor has maintained the historical interdependency of "slash-and-burn" agriculture, wage work, and forest conservation. By facilitating the discovery of species while unintentionally perpetuating the conditions of habitat endangerment, the conservation labor process creates forms of rain forest value.     

The Nurse of Parasites: Gender Concepts in Patrick Manson's Parasitological Research

Patrick Manson (1844-1922), the so-called father of tropical medicine, played a pivotal role in making that discipline into a specialty. During his early career in China he discovered that the mosquito was the intermediate host of the filarial parasite and he somewhat peculiarly called the mosquito the "nurse" of the filarial worm. The discovery contributed greatly to the intellectual foundation of modern parasitology. In this paper I situate Manson's nomenclature in the context of nineteenth-century biological research on reproductive mech-anisms and argue that Manson's concept of the "nurse" was derived from nineteenth-century theories of sexual division of labor in nature's economy. The way he framed the relation between the mosquito and the parasite, moreover, can be understood in the terms of the domestic arrangement of the colonial European household. Manson's research demonstrates the significant exchange between medical concerns over European women's procreative role in the tropics and biological studies of parasitic reproduction.     

Spatial organization in a dimorphic ant: caste specificity of clustering patterns and area marking

Living in groups constitutes the root of social organizationin animals. Likewise, the spatial aggregation between membersof insects societies plays a crucial role in social cohesionand division of labor, namely, in polymorphic ant species. Inthe present paper, we show caste-specific aggregation patternsin the strictly dimorphic Pheidole pallidula ant species. Weinvestigate the influence on the clustering of ants exertedby direct contacts between nest mates as well as by indirectcues through chemical marking. In a homogeneous environmentdeprived of chemical cues, majors show a higher aggregationlevel than minors and a centripetal behavior. By contrast, minorsare more scattered in the experimental arena and display a centrifugalbehavior. In addition, area marking laid by minors enhancestheir own aggregative behavior while contributing to the localizationof the spontaneously aggregating majors. Such differences inaggregative patterns as well as their adaptive value have tobe coupled with the mobility level and the task performanceefficiency of each worker caste. Contrary to majors that arelikely to aggregate, highly mobile minors, scattered insideand outside the nest colony, can detect colony needs and cancarry out most of the daily tasks for which they are more efficientthan majors.     

Altruistic cooperation during foraging by the Ache, and the evolved human predisposition to cooperate

This paper presents quantitative data on altruistic cooperation during food acquisition by Ache foragers. Cooperative activities are defined as those that entail a cost of time and energy to the donor but primarily lead to an increase in the foraging success of the recipient. Data show that Ache men and women spend about 10% of all foraging time engaged in altruistic cooperation on average, and that on some days they may spend more than 50% of their foraging time in such activities. The most time-consuming cooperative activity for both sexes is helping during the pursuit of game animals, a pattern that is probably linked to the widespread sharing of game by Ache foragers. Cooperative food acquisition and subsequent food redistribution in hunter-gatherer societies are critical behaviors that probably helped shape universal, evolved, cooperative tendencies that are well illustrated in modern experimental economics. This paper was originally presented at a Max Planck symposium on cooperation in Leipzig in June 1999. This work was partially funded by a grant from the L.S.B. Leakey Foundation and NSF grant BNS 9727656. Kim Hill is a professor of anthropology in the Human Evolutionary Ecology (HEE) program at the University of New Mexico. His primary research interests include hunter-gatherer behavioral ecology, life history theory, food acquisition strategies, food sharing, cooperation, and biodiversity conservation in lowland South America. He has done fieldwork with Nahautl, Ache, Guarani, Hiwi, Mashco Piro, Matsiguenga, and Yora indigenous peoples of Central and South America.