Aspects of fetal physiology from 18 to 37 weeks' gestation as assessed by blood sampling

OBJECTIVE: To construct reference ranges for fetal pH, oxygen pressure (PO2), and hematologic and biochemical blood constituents, which can be used to analyze changes with gestation and differences with maternal values, thus elucidating some aspects of fetal biology and the effects of the maternal and placental environments. METHODS: We assayed venous pH, PO2, hematocrit, glucose, uric acid, urea, creatinine, total protein, total and direct bilirubin, aspartate aminotransferase, alanine aminotransferase, gamma-glutamyltransferase, alkaline phosphatase, lactic dehydrogenase, amylase, pseudocholinesterase, creatine kinase, triglycerides, and cholesterol concentrations in 157 fetuses and 134 mothers who underwent fetal blood sampling from 18 to 37 weeks' gestation. None of the fetuses was infected or had chromosomal, hematologic, or hormonal abnormalities. RESULTS: All the variables analyzed were similar in fetuses sampled at the placental cord insertion (n = 125) or at the intrahepatic vein (n = 32). Maternal and fetal concentrations of glucose (r = 0.79, P < .001), urea (r = 0.96, P < .001), creatinine (r = 0.83, P < .001), and uric acid (r = 0.94, P < .001) correlated significantly, and their differences exhibited significant changes: the maternal-fetal differences of glucose and urea increased, whereas those of uric acid and creatinine decreased with advancing gestation. Fetal pH and PO2 decreased with gestational age, whereas hematocrit increased, similar to what has been described previously. All of the other variables, with the exception of amylase and cholesterol, changed significantly during the investigated period of pregnancy. Gestational age explained at least 40% of the variance in values of fetal total protein, pseudocholinesterase, alanine aminotransferase, creatine kinase, and triglycerides, but only 3-25% of the variation in the remainder. Most enzymes were higher in the fetus than in the maternal circulation, and all except alkaline phosphatase increased with gestational age. The maternal-fetal glucose difference correlated significantly with hematocrit, pH, and PO2, independent of gestational age and independent of each other. CONCLUSION: With the exception of aspartate aminotransferase, all of the analyzed fetal variables were different from the maternal values, and most changed with gestational age. The mechanisms leading to these fetal specificities remain mostly uncertain, but the provision of reference ranges for several blood constituents may be useful in the differential diagnosis of fetal disease.     

Constipation in the elderly

Constipation affects as many as 26 percent of elderly men and 34 percent of elderly women and is a problem that has been related to diminished perception of quality of life. Constipation may be the sign of a serious problem such as a mass lesion, the manifestation of a systemic disorder such as hypothyroidism or a side effect of medications such as narcotic analgesics. The patient with constipation should be questioned about fluid and food intake, medications, supplements and homeopathic remedies. The physical examination may reveal local masses or thrombosed hemorrhoids, which may be contributing to the constipation. Visual inspection of the colon is useful when no obvious cause of constipation can be determined. Treatment should address the underlying abnormality. The chronic use of certain treatments, such as laxatives, should be avoided. First-line therapy should include bowel retraining, increased dietary fiber and fluid intake, and exercise when possible. Laxatives, stool softeners and nonabsorbable solutions may be needed in some patients with chronic constipation.     

Effects of age on the biomechanics and physiology of gait

There are significant changes in gait across the life span, but particularly after the age of 70 years. This article reviews the physiology of gait and the motor control challenges during gait. The kinematics (motion) and the kinetics (moment and power) of normal gait of a database of healthy young and older adults are compared. Older subjects generate significantly lower peak ankle plantar flexor power during gait. The clinical significance of the reduction in ankle plantar flexion power is discussed.     

Anatomy and physiology of the kidney

The kidneys are complex organs, and they are vital in maintaining normal body functions. A human being's survival depends, to a large degree, on the crucial functions and processes performed by the kidneys. The renal system affects all parts of the body by keeping body fluids in balance and other organ systems functioning normally. Renal and urologic disorders may strike anyone at any age and at any time. An estimated 20 million Americans are affected with renal disorders each year.     

动态排粪造影在诊断及指导治疗功能性出口梗阻便秘中的临床价值

目的:探讨动态排粪造影在诊断功能性出口梗阻便秘中的价值.方法:对86例功能性出口梗阻性便秘患者进行排粪造影检查,女性81例,男性5例,年龄23岁- 80岁,平均年龄42岁,病史3个月到30年.结果:对86例患者排粪造影检查,发现会阴下降71例,直肠前突75例,直肠粘膜脱垂5例,盆底疝6例(乙状结肠疝4例,小肠疝2例),内脏下垂6例,直肠内套叠1例.结果:术后临床症状消失69例,症状改善10例,症状改善不明显7例,治愈率为92%.结论:动态排粪造影对诊断功能性出口梗阻及手术术式的选择及判定有重要的指导作用.     

Dietary copper in the physiology of the microcirculation

Dietary copper has long been known to be essential for cardiovascular homeostasis. However, the role of copper and cuproenzymes in the normal control of vascular physiology is not well understood. Most studies in the cardiovascular system have focused on copper deficiency-induced defects in the heart or large vessels. Recently, attention has also focused on the effects of copper deficiency in the microcirculation or the small blood vessels that control blood flow, nutrient and waste exchange, and peripheral vascular resistance. Studies in the microcirculation demonstrate that copper is important in mechanisms of macromolecular leakage, platelet-endothelial interactions and vascular smooth muscle reactivity. There is a significantly greater leakage of proteins from postcapillary venules in copper-deficient rats in response to mast cell-released histamine. This response appears to be the result of increased numbers of mast cells and thereby increased available histamine. Copper deficiency also causes an inhibition of in vivo thrombogenesis, which appears to be related to an inhibition of platelet adhesion. Subsequent studies have demonstrated that this is probably caused by a diminished concentration of the adhesion molecule von Willebrand factor. Nitric oxide (NO)-mediated arteriole vasodilation is also compromised in copper-deficient rats. This functional deficit to NO can be reversed by the addition of Cu, Zn-superoxide dismutase (SOD), suggesting that degradation of NO by superoxide anion occurs during copper deprivation. These observations demonstrate that dietary copper is necessary for several microvascular control mechanisms affecting inflammation, microhemostasis and regulation of peripheral blood flow.     

以企业标准为先导提高一钢公司竞争力

分析了一钢公司原有的标准体系,认为原标准体系已不能适应今后不锈钢精品基地的需要.结合今后不锈钢精品基地国内领先、国际先进的总体要求,论述了重新确立适合不锈钢精品基地的标准体系框架,制定需编制和确定的标准目录的必要性.     

Review of endocrine physiology

Growth is a complex process in fish. This study was designed to test the effect of different levels of recombinant tilapia growth hormone (tiGH) injected intraperitoneally in juvenile hybrid tilapia Oreochromis hornorum. Tilapia GH cDNA was cloned from hybrid O. hornorum tilapia. The mature protein was expressed in E. coli under regulation of the phage T7 promoter. The E. coli-derived tiGH was partially purified to 67% purity and, following renaturation, was shown to be biologically active in in vivo and in vitro assays. Recombinant tiGH stimulated extracellular matrix synthesis as shown by 35S-sulfate uptake in ceratobranchial cartilage explants. Zero, 0.1, 0.5 and 2.5 μg tiGH/g body weight (gbw) were injected in tilapia, and the effects on the growth-promoting action, hepatosomatic index (HSI), and mRNA insulin-like growth factor (IGF) induction were measured. A significant increase in the body weight (P < 0.05) and length (P < 0.01) was observed in tilapia receiving 0.5 μg tiGH/gbw. However, tilapia receiving 0.1 and 2.5 μg tiGH/gbw did not show an increase in body weight and length with respect to the control group receiving BSA injections. Binding sites for the recombinant tiGH were identified in the liver. Consistent with its somatotropic actions, the IGF mRNA induction was observed in the groups injected with 0.1 and 0.5 μg tiGH/gbw (P < 0.05). No significant increase in the HSI was detected in the injected groups when compared to the control group. These results demonstrated that the injection of biologically active E. coli-derived tiGH produces physiological changes in juvenile tilapia that ultimately resulted in a growth-promoting action only at a dose of 0.5 μg tiGH/gbw.     

巫筮与理性——从天人关系的衍化看荀子礼学的根源

荀子礼学根源于原始宗教的瓦解和人文精神的觉醒.天代表巫筮传统,人代表理性传统.天、人内涵经历了一个从绝地天通,到不语怪力乱神、尽心知性,再到明于天人之分的衍化.这是荀子礼学的理论之根.     

Working on the basis of collective and lease contracts

Vocational-Economic Training

Working on the basis of collective and lease contracts     

The physiology of spasticity

The contractile effects of ATP and related purine compounds on the isolated rabbit detrusor were investigated. It was found that ATP produced an initial rapid, phasic contraction followed by a slowly developing and maintained increase in tension. ADP caused a contraction closely mimicking the tonic response to ATP. The ADP induced contraction and the tonic response to ATP could both be abolished by indomethacin. beta, gamma-methylene ATP (APPCP), which is not degraded to ADP, elicited a rapid, phasic response, which could be abolished by nifedipine. AMP, dibutyryl-cAMP, and adenosine in low concentrations had no contractile effects; high concentrations of adenosine and 2-chloroadenosine, which is resistant to adenosine deaminase, decreased tone and spontaneous activity. The amplitude of the ATP induced contraction was positively correlated to the Ca2+-concentration in the extracellular medium; removal of Ca2+ abolished the ATP contraction before the responses to high K+ and carbachol disappeared. Responses to electrical field stimulation, mediated by non-cholinergic, non-adrenergic mechanisms were abolished by nifedipine and significantly reduced by indomethacin. It is concluded that in isolated rabbit detrusor, a direct contractile response can be elicited only by tripolyphosphates (ATP and APPCP), and that the diphosphate moiety ADP stimulates synthesis of prostaglandins The similarity between the effects of stimulation of non-cholinergic, non-adrenergic neurones and the phasic response to ATP supports the view that in rabbit detrusor ATP may be involved in excitation.     

The physiology of erection

The majority of contemporary knowledge on the physiology of erection was assembled during the past thirty years. Today we consider erection as a multifactorial process. Mechanically it can be compared to an electromechanically controlled hydraulic system. Its function is conditioned by a number of mutually coordinated processes. As to nervous processes they include autonomous (parasympathetic and sympathetic) innervation, as well as somatic innervation (sensory and motor pathways). The control function is exerted by spinal as well as cerebral centres. As to mediators, in particular acetylcholine, nitrous oxide (NO) released from the endothelium are involved, noradrenaline, VIP (vasoactive intestinal polypeptide), CGRP (calcitonin gene-related peptide) and prostaglandins. The most important roles in the phase of erection are played by nitrous oxide and VIP. Erection can be either reflex erection, psychogenic or nocturnal or morning. It usually takes place in six stages (at rest, latent, the tumescence stage, complete erection, rigid erection and subsequently the stage of detumescence). Except for neurohumoral mechanisms an essential prerequisite for the development of erection are the arterial supply of the genital and the so-called venoocclusive mechanism. Erection takes the following course (simplified): erotogenic stimuli lead to the stimulation of the parasympathetic nerve-->vasodilating substances are released-->the s inusoids are filled with blood (tumescence stage)-->the venoocclusive mechanism starts to work: thus complete erection occurs. Then the contractions of the musculature of the perineum compress the proximal portions of the corpora cavernosa: this leads to rigid erection. Detumescence which occurs as a rule after ejaculation) is due to released noradrenaline (active stage) and the reduced tonus of the smooth muscles of the blood vessels (released endothelin and neuropeptide Y). Knowledge of the physiological mechanisms of erection made clinical diagnosis of their disorders and successful treatment of some forms of impotence possible.     

Improvement of reduction on the basis of the ARM Tekhnologa model

A model of direct iron production by pellet reduction in a shaft furnace has been developed. This model includes the material and energy balances of all the main components of the reduction system (shaft furnace, reformer, etc.) and is based on ARM Tekhnologa software for the analysis and optimization of the reduction conditions at OAO OEMK. The calculation results may be used in the reconstruction of the reduction system and implemented in practice. To predict the reduction conditions and control the direct production of iron, a determinate model of the heat and mass transfer and gas dynamics in the bed is added to ARM Tekhnologa software. This supplementary model simulates the reduction dynamics of a pellet in the shaft furnace and expands the scope for calculating new reduction conditions, so as to boost product output and quality.