ATLAS OF ROENTGENOGRAPHIC POSITIONS

Mere diagnosis of a valvular heart lesion without circulatory incapacity is inconsequential in considering the prognosis for a pregnant woman.There are grave dangers of heart failure during pregnancy, labor or the postpartum period in women who have had congestive failure prior to pregnancy or during a previous pregnancy and delivery.Decisions as to whether or not to recommend avoidance of pregnancy or therapeutic abortion should depend not alone upon the prospect of death during gestation or at the time of delivery, but also upon the possibility of increased impairment of heart function and physical incapacity of the mother in the postpartum period.Because of the extensive surgical procedure there are few indications for interrupting pregnancy after the third lunar month; and because the major circulatory loads do not increase after the eighth month, rarely should labor be prematurely induced after that time.The exertion of labor, although generally inconsequential, in some cases may produce sustained oxygen debt. In cases in which labor in a previous pregnancy has been accompanied by heart failure, cesarean section should be considered as a means of lessening the possibility of serious failure or death, although this is not a frequent consideration.In the resemblance of circulatory changes that occur, during delivery and immediately postpartum, to those changes produced by the closure of an arteriovenous shunt or patent ductus arteriosus, lies a suggestion as to some of the causative factors in heart failure during or soon after delivery. Probably of great importance is the decrease in blood volume and hemoconcentration at delivery followed by the return of water to the circulatory system, with consequent transient increase in blood volume, in the postpartum period. Additionally, the rise of venous pressure after use of oxytocic drugs suggests that rapid infusion of blood from an engorged uterus may cause an abrupt and perhaps poorly tolerated hypervolemia.Death by heart failure in pregnancy and the puerperium has become extremely rare in recent years due to the frequent observations, meticulous diagnosis of impending failure and improved care of cardiac patients jointly by the obstetrician and the internist. In addition to digitalis therapy and sodium restriction, patients exhibiting evidence of impending heart failure may require bed rest through the entire third trimester of pregnancy. Oxygen should be administered during labor in such patients and anoxia guarded against during anesthesia.     

Heart disease as a complication of pregnancy; with emphasis on indications for recommending therapeutic abortion or avoidance of conception

Mere diagnosis of a valvular heart lesion without circulatory incapacity is inconsequential in considering the prognosis for a pregnant woman.There are grave dangers of heart failure during pregnancy, labor or the postpartum period in women who have had congestive failure prior to pregnancy or during a previous pregnancy and delivery. Decisions as to whether or not to recommend avoidance of pregnancy or therapeutic abortion should depend not alone upon the prospect of death during gestation or at the time of delivery, but also upon the possibility of increased impairment of heart function and physical incapacity of the mother in the postpartum period. Because of the extensive surgical procedure there are few indications for interrupting pregnancy after the third lunar month; and because the major circulatory loads do not increase after the eighth month, rarely should labor be prematurely induced after that time.The exertion of labor, although generally inconsequential, in some cases may produce sustained oxygen debt. In cases in which labor in a previous pregnancy has been accompanied by heart failure, cesarean section should be considered as a means of lessening the possibility of serious failure or death, although this is not a frequent consideration. In the resemblance of circulatory changes that occur, during delivery and immediately postpartum, to those changes produced by the closure of an arteriovenous shunt or patent ductus arteriosus, lies a suggestion as to some of the causative factors in heart failure during or soon after delivery. Probably of great importance is the decrease in blood volume and hemoconcentration at delivery followed by the return of water to the circulatory system, with consequent transient increase in blood volume, in the postpartum period. Additionally, the rise of venous pressure after use of oxytocic drugs suggests that rapid infusion of blood from an engorged uterus may cause an abrupt and perhaps poorly tolerated hypervolemia. Death by heart failure in pregnancy and the puerperium has become extremely rare in recent years due to the frequent observations, meticulous diagnosis of impending failure and improved care of cardiac patients jointly by the obstetrician and the internist. In addition to digitalis therapy and sodium restriction, patients exhibiting evidence of impending heart failure may require bed rest through the entire third trimester of pregnancy. Oxygen should be administered during labor in such patients and anoxia guarded against during anesthesia.     

Survival after replantation.

Over a seven-year period in one unit performing replantation surgery 63 parts were replanted in 49 patients with an overall survival rate of 60%, which represents a worthwhile salvage of tissue otherwise not available for reconstruction. As the median operation time was eight hours (range 5-22) the implication of providing such prolonged operative procedures on the resources of the Health Service must be seriously considered. Yet there is a failure of awareness among the medical profession of the possibilities of such treatment, and potentially viable parts may be being discarded.     

Inhibitory effects of hyperthermia on mechanisms involved in autoresuscitation from hypoxic apnea in mice: a model for thermal stress causing SIDS.

The physiological mechanisms that might be involved in an association between heat stress and sudden infant death syndrome (SIDS) are obscure. We tested the hypothesis that a combination of acute hypoxia and elevated body temperature (T(B)) might prevent autoresuscitation from hypoxic apnea (AR). We exposed 21-day-old mice (total = 216) to hyperthermia (40.5-43.5 degrees C), hypoxia, or a combination of the two. Neither hyperthermia alone (40.5-42.5 degrees C) nor hypoxia alone was found to be lethal, but the combination produced failure to AR during the first hypoxic exposure with increasing frequency as T(B) increased. The ability to withstand multiple hypoxic exposures was also reduced as T(B) increased. In contrast, heat stress causing moderate T(B) increase (40.5 degrees C) had no effect on survival. Increased T(B) (43.5 degrees C) reduced gasping duration and number of gasps. It increased heart rate during anoxia but did not alter gasping rate. Furthermore, the oxygen-independent increase in heart rate observed before gasping failure was usually delayed until after the last gasp in hyperthermic animals. Mild dehydration occurred during T(B) elevation, but this did not appear to be a primary factor in AR failure. We conclude that a thermal stress, which by itself is nonlethal, frequently prevents AR from hypoxic apnea. This may be due, at least in part, to decreased gasp number and duration as well as to hyperthermia-related asynchrony of reflexes regulating heart and gasping frequencies during attempted AR.     

Synthesis and secretion of albumin and transferrin by foetal rat hepatocyte cultures

Hepatocytes derived from foetal rat liver synthesize and secrete albumin and transferrin when maintained in primary culture. These proteins are produced for at least seven days under the conditions of culture. Studies on hepatocyte cultures derived from 12, 13, 14, 15 and 19-day foetal rats show that the maximal cellular rate of secretion of both proteins increases about 50-fold over this period. The maximal rate of albumin secretion in all cultures is achieved after one day in culture and decreases in hepatocytes from early foetuses after the fourth to sixth day in culture. Transferrin secretion by hepatocytes from 12 to 15 day foetuses increases markedly during the second day of culture and is relatively constant thereafter. In contrast, secretion of transferrin by hepatocytes from 19-day foetuses is constant from the first day of culture. The results show that both albumin and transferrin are synthesized and secreted by the foetal liver as early as the twelfth day of gestation. The increase in the rate of transferrin secretion that occurs during culture of hepatocytes from 12 to 15 day foetuses may reflect the development of a secretory mechanism that is different from that for albumin.     

A role for aromatizable androgens in female rat puberty

The function that aromatizable androgens may have in female puberty is unclear. The present experiments were undertaken to examine, using a quantitative approach, the role that physiological levels of these androgens may play in determining the timing of vaginal opening and first ovulation in female rats. Serum androstenedione (delta 4) levels increased markedly between Postnatal Days 4 and 8, remained elevated through Day 16, and declined thereafter to remain at about 100 pg/ml throughout juvenile development (Days 20-32). Serum testosterone (T) also increased, though less prominently after Postnatal Day 4. Maximal values were found at Day 12 (about 150 pg/ml); thereafter, T levels decreased to intermediate values (about 100 pg/ml), which were maintained during juvenile days. Serum dehydroepiandrosterone (DHA) remained undetectable throughout prepubertal development. At puberty, serum delta 4 increased 2.5-fold, but only at the time of the preovulatory luteinizing hormone (LH) surge. In contrast, T levels increased significantly 2-fold on the early proestrous-2 phase of puberty, 3.5-fold on the morning of first proestrus, and 9-fold at the time of the LH surge. Serum DHA remained undetectable. Implantation of Silastic capsules containing T at 2 or 6 mg/ml oil into juvenile 28-day-old rats resulted in serum T levels similar to those found on early proestrous 2 (about 150-180 pg/ml) and at 1300 h of first proestrus (ca. 300-400 pg/ml), respectively. Both treatments induced precocious vaginal opening, but failed to advance first ovulation. About 50% of the T-implanted rats had ambiguous estrous-type vaginal cytology preceding the day of first diestrus, and failed to show corpora lutea at this time.(ABSTRACT TRUNCATED AT 250 WORDS)     

Age-related hematological changes in normal F344 rats: during the neonatal period.

In order to clarify age-related changes in hematological values of normal rats after birth, blood samples from neonatal F344 rats of both sexes were examined periodically during the period from 0 to 40 days postpartum. The erythrocyte count (RBC) increased with time after birth as a function of age. In contrast, the reticulocyte count (Retics) continuously decreased with time after birth. Hemoglobin (Hb), hematocrit (Ht), and the mean corpuscular hemoglobin concentration (MCHC) tended to decrease after birth until weaning (about 21 days postpartum), but they began to increase after weaning. Mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) also gradually decreased after birth until weaning, but they were unchanged thereafter. The platelet count (PLT) gradually increased after birth and reached a plateau at weaning. Microscopic examination of blood smears revealed that erythrocytes at birth had characteristic morphological features such as anisocytosis, polychromasia, basophilic stippling, Howell-Jolly body, and erythroblastosis. These characteristic features, however, disappeared by 30 days after birth. The total leukocyte count (WBC) gradually increased with time after birth, due to an increase in the number of lymphocytes. The lymphocyte count started to rapidly increase within several days after birth and the increase continued thereafter. Other differential leukocyte counts also showed various characteristic patterns of changes during the neonatal period. There were no apparent differences between males and females in these changes in hematological values.     

A longitudinal study of leptin during development in the male rhesus monkey: the effect of body composition and season on circulating leptin levels

The objective of this study was to examine longitudinal changes in serum leptin concentrations during development and to correlate those changes with sexual development in male rhesus monkeys housed under natural environmental conditions. Blood samples were drawn from 8 control animals approximately every other month from 10 to 30 mo of age and thereafter monthly through 80 mo of age. Leptin levels declined through the juvenile period until the onset of puberty and were negatively correlated with body weight. Seven of the eight animals became sexually mature during the breeding season of their fourth year of life. Puberty was delayed in the other animal until the subsequent breeding season. There were no significant fluctuations in leptin levels prior to or in association with the pubertal rise in LH and testosterone (T) secretion. During the peripubertal period, levels of leptin varied between 2 and 3 ng/ml. The animal that exhibited delayed puberty had the lowest body weight and highest leptin levels during this period. With the achievement of sexual maturity, leptin levels varied seasonally, with peak levels in the late winter (Jan-Mar) and a nadir in the late summer (Aug-Sept). A late winter rise in leptin was also evident in most of the animals during Years 2 and 3, but not during Year 4. In the fall of Years 5 and 6, the seasonal rise in leptin concentrations lagged 3-4 mo behind the seasonal increase in LH and T. In the fall of Year 5, but not thereafter, leptin levels were positively related to percent body fat and negatively correlated with lean body mass. The data do not support the hypothesis that increasing leptin concentrations trigger the onset of puberty in the male rhesus monkey. During the juvenile period and after sexual maturation, but not during the peripubertal period, leptin secretion varied with season in the animals; but the environmental factors that cue or drive this rhythm remain to be determined.     

Effects of three-hour restricted food access during the light period on circadian rhythms of temperature, locomotor activity, and heart rate in rats

The effects of food on biological rhythms may influence the findings of chronopharmacological studies. The present study evaluated the influence of a restricted food access during the rest (light) span of nocturnally active Wistar rats on the 24 h time organization of biological functions in terms of the circadian rhythms of temperature (T), heart rate (HR), and locomotor activity (LA) in preparation for subsequent studies aimed at evaluating the influence of timed food access on the pharmacokinetics and pharmacodynamics of medications. Ten-wk-old male Wistar rats were housed under controlled 12:12 h light:dark (LD) environmental conditions. Food and water were available ad libitum, excepted during a 3 wk period of restriction. Radiotelemetry transmitters were implanted to record daily rhythms in T, HR, and LA. The study lasted 7 wk and began after a 21-d recovery span following surgery. Control baseline data were collected during the first wk (W1). The second span of 3 wk duration (W2 to W4) consisted of the restricted feeding regimen (only 3 h access to food between 11:00 and 14:00 h daily) during the L (rest span) under 12:12 h LD conditions. The third period of 3 wk duration (W5 to W7) consisted of the recovery span with ad libitium normal feeding. Weight loss in the amount of 5% of baseline was observed during W1 with stabilization of body weight thereafter during the remaining 2 wk of food restriction. The 3 h restricted food access during the L rest span induced a partial loss of circadian rhythmicity and the emergence of 12 h rhythms in T, HR, and LA. Return to ad libitum feeding conditions restored circadian rhythmicity in the manner evidenced during the baseline control span. Moreover, the MESORS and amplitudes of the T, HR, and LA 24 h patterns were significantly attenuated during food restriction (p < 0.001) and then returned to initial values during recovery. These changes may be interpreted as a masking effect, since T, HR, and LA are known to directly react to food intake. The consequences of such findings on the methods used to conduct chronokinetic studies, such as the fasting of animals the day before testing, are important since they may alter the temporal structure of the organism receiving the drug and thereby compromise findings.     

Perinatal development of glucose-6-phosphatase and fructose-1,6-diphosphatase activities in pig liver

The activity of glucose-6-phosphatase (G6Pase) and fructose-1,6-bisphosphatase (FDPase) was determined in the homogenate of the liver of 69 pig fetuses during the last third of gestation (80th to 114th day), 47 piglets from birth to 4 weeks old (suckling period) and to slaughter pigs. G6Pase is evident in fetal liver at an early date and raises steadily during gestation. In newborn piglets, the enzyme activity increases rapidly during the first hours of life and remains at this high level during the first week of life. Afterwards the enzyme activity returns to birth level, which exists also in pigs at slaughtering. The activity of FDPase is constant during the fetal period. After birth enzyme activity rises at a lower rate than the G6Pase during the first week of life. This level remains constant during the suckling period and increases thereafter until the time of slaughtering of pigs. The role of hormones in the perinatal development of these enzymes is described. Probably, thyroxine causes the prenatal increase of the activity of both the enzymes. The rapid postnatal rise of G6Pase activity may be induced by the high level of hydrocortisone at parturition, and furthermore, glucagon may have a permissive effect.     

Induction of asparagine synthetase during lymphocyte activation by phytohemagglutinin

Asparagine synthetase was increased in cultured mouse spleen lymphocytes after stimulation by phytohemagglutinin. After a lag period of about 24h, the enzyme activity level rose sharply by 48h, reached its maximum at 72h, and decreased thereafter. The time course of the change in the enzyme activity was similar to that of the change in the rate of DNA synthesis. From the results that there was no increase of the activity of asparagine synthetase at the time induction of ornithine decarboxylase would occur (6h), it seems unlikely that asparagine synthesized in the cells contributes to the enhancement of ornithine decarboxylase during the activation of lymphocytes. The increase of asparagine synthetase activity was inhibited by cycloheximide and somewhat by actinomycin D, suggesting de novo enzyme synthesis during the stimulation.     

微创经皮肾穿刺碎石术（MPCNL）治疗上尿路结石的临床分析

目的：探讨微创经皮肾穿刺碎石术（MPCNL）用于治疗尿路结石的临床效果。方法：选取120例单侧上尿路结石病患者,随机分为两组,每组60人。一组应用微创经皮肾穿刺碎石术（MPCNL）进行一期单通道上尿路取石,另一组采用开放手术治疗。比较并分析两组患者的临床疗效。结果：应用MPCNL治疗的60名患者中,结石清除的有55名,清除率为91．17％,手术时间平均为77分钟,住院时间平均为5-3天。术中平均出血100mL,术后发生大出血者一例,经输血后好转,术后发热者38例,发热比例为63-3％,尿液转清时间平均为2．5天。应用开放式手术的60名患者中,结石清除的有39例,清除率为65．0％,平均手术之间为112分钟,住院时间平均为18．1天,术中平均出血380mL,术后发生大出血者9例,经输血后好转,术后发热者43例,发热比例为71．2％,尿液转清时间平均为8．6天。结论：MPCNL方法治疗上尿路结石的效果明显比开放式手术好,具有清除率高、手术时间短、术后并发症少、术后感染少以及患者恢复快的优点。     

Influence of urethane and of hydrostatic pressure on the growth of bacteriophages T2, T5, T6, and T7

In 0.5 per cent NaCl, nutrient broth at 35 degrees C., urethane in a concentration of 0.4 M stops the reproduction of Escherichia coli, strain B. On dilution with 20 volumes of sterile medium, growth is resumed at its former rate after a short lag. In the one-step growth of T2, 15, T6, or T7, in the same medium at the same temperature, 0.4 M urethane, when added at the time of infection, had no apparent effect on adsorption and caused no decrease in titer throughout the latent period of the control, but completely prevented a rise in titer. If diluted 1:20 with sterile medium prior to a certain critical time in the latent period, however, bacteriophage was liberated at the same time, and in the same amount as in the control. The initial stage of apparent insensitivity to the drug lasts from the time of infection until the approximate critical times of 7 minutes with T7, T2, or T6, or 13 minutes with T5. Under the conditions described, the normal latent periods were 14, 23, 30, and 44 minutes for T7, T2, T6, and T5, respectively. At the critical times referred to above, there begins a stage characterized by complete sensitivity, rather than complete insensitivity, to 0.4 M urethane, in the sense that no active phage is subsequently liberated in continued presence of the drug. The length of this completely sensitive stage, as judged by addition of the drug at successive intervals during the latent period, extends from approximately 7 until 9 minutes after infection with T7, 7 until 15 minutes with T2 or T6, or 13 until 25 minutes with T5. When the urethane is added late in this stage of T2, a decrease in initial titer takes place as judged by assays made 40 minutes after infection, the maximum effect occurring when the drug is added between 14 and 15 minutes after infection. When added subsequently to the completely sensitive stage of each type, i.e. subsequently to 9 minutes after infection with T7, 15 minutes with T2 or T6, or 25 minutes with T5, liberation of the bacteriophage takes place in presence of the drug, but the yield is reduced, the amount of reduction being greater the sooner it is added. The yield increases as addition of the drug is delayed, but it is measurably reduced when added late in the rise period. Macroscopic lysis with T7 is delayed by 0.4 M urethane, when present from the time of infection. The delay is less with increased multiplicities of infection. A similar delay occurs with T6r at a multiplicity of 4. The application of hydrostatic pressures of 7,000 to 9,000 p.s.i. early in the latent period, within 5 to 8 minutes after infection, prevents a yield in each of the four phage types, and if maintained for lengthy periods of time a reduction in initial titer occurs. If released at various times shortly after the latent period, a rise in the titer occurred after a certain interval whose length was characteristic of the phage type. The yield was less the longer the release of pressure was delayed. When the pressure was first applied late in the latent period, large amounts of phage were liberated either under pressure or explosively when pressure was released to make the assays. Hydrostatic pressure at 6,000 p.s.i. had little effect on the rate or amount of macroscopic clearing with T7 in relatively high multiplicity of infection, when applied at the start of lysis, but slowed the rate and reduced the amount of clearing when applied shortly after infection.     

Exhaustion of type I interferon response following an acute viral infection

Viral infections often cause a period of heightened susceptibility to a secondary infection but the cause of this phenomenon is unknown. We found that a primary viral infection in mice rapidly triggers an IFN-I-dependent partial activation state in the majority of B and T lymphocytes, which reverts to a resting phenotype within 5 days. When a secondary infection with an unrelated virus occurred 5 to 9 days after the primary infection, no recurrence of marked activation of lymphocytes was observed. This was not due to an inherent inability of the previously activated cells to undergo renewed partial activation, because they responded when challenged with virus after transfer into "naive" recipients. Instead, the failure to respond optimally resided in the original host's incapacity to mount an IFN-I response to the secondary infection during this time period. Thus, transient immunosuppression through exhaustion of IFN-I production during an acute viral infection creates a time period of enhanced susceptibility to secondary infection.     

Lipid synthesis and deposition by adult Richardson's ground squirrels in the natural environment

Summary Adult male Richardson's ground squirrels,Spermophilus richardsonii, were estimated to have emerged from hibernation in late February to early March, and adult females in mid to late March. Half of the females trapped in late March were not pregnant, as against 10% after that time. In late March males and all females had similar WAT (white adipose tissue) deposits. Between late March and early June, WAT deposits in males increased from 14 g to 64 g (a rate of 5.6 g per week). In non-parous females WAT deposits increased from 13 g to 48 g from late March to late May (4.2 g per week). Fat deposits decreased during lactation but thereafter increased from 8 g to 29 g (a rate of 6.0 g per week) between early May and early June. In males the rate of fatty acid synthesis in BAT (brown adipose tissue), liver and WAT did not change from late March to late May, and rates in the corresponding tissues of non-pregnant females were similar to those in males. Fatty acid synthesis decreased during late pregnancy and lactation. After lactation, the rate of fatty acid synthesis in all tissues increased to that in males and non-pregnant females. Males initiated fattening 5–7 weeks earlier than females. It is concluded that compared with adult males, the later immergence of adult female Richardson's ground squirrels into hibernation is due primarily to later initiation of fattening and less to differences in rate of lipid synthesis after the reproductive period. Rates of fatty acid synthesis in liver and BAT were several times greater than that in WAT. The former tissues may contribute fatty acids for prehibernatory fattening.Abbreviations BAT brown adipose tissue - WAT white adipose tissue     

Relationship between cell division and endogenous auxin in synchronously-cultured tobacco cells

In the cultured tobacco cell, we succeeded in obtaining a partial synchronization of cell division by a combination of pre-starvation, rhythmic light-dark pre-treatment and air tight pre-conditioning. The mitotic index increased during the light period according to the time interval after the end of pre-treatment, and reached its maximum (max=12%) at about 2.5 hr of irradiation, and about 80% of cells completed division 1.5 hr thereafter. During this period, IAA was biosynthesized in the cells, though these cells had been cultured in Murashige and Skoog's medium with 1 mg/l of 2,4-D as a growth substance. IAA was identified by paper chromatography, followed byAvena curvature test and combined gas chromatography-mass spectrometry. The time course of the increase and decrease in the amount of free IAA was parallel to that of the mitotic index. On the other hand, bound IAA increased later and decreased gradually after the end of cell division. Free IAA may have an important role in mitosis.     

鼎湖山生物圈保护区马尾松林凋落物的分解及其营养动态研究

 本文报道了鼎湖山生物圈保护区马尾松林凋落物分解及其营养动态的情况。松针和混合凋落物的失重率在试验过程中均呈直线下降。松针和混合凋落物的分解系数(K)分别为0.44a-1和0.37a-1。在凋落物分解过程中氮是5个元素中唯—的1个元素,它表现出浓度和绝对量均首先呈上升然后下降的变化。磷和钙的浓度和绝对量在凋落物分解过程中,表现相类似的变化模型。它们的释放速率较其它元素更类似于凋落物的失重率。钾是5个元素中最活跃的元素。其浓度和绝对量的变化在凋落物分解过程中相类似：在分解初期(30到50天)迅速下降后呈缓慢的变化。镁的浓度和绝对量在分解初期以相对快的速率下降后,呈现两种绝然不同的变化：绝对量渐渐下降而浓度则慢慢上升。5个元素的流动性比较,在两种凋落物的分解过程中,均早K>Mg>P>Ca>N的顺序变化。