[Radiation monitoring of the workplace (IX). Air monitoring. (5) Measurement of concentration of tritiated water vapor, 14C and 35S in air (author's transl)].
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Plants have too long been ignored as useful screening and monitoring systems of environmental mutagens. However, there are about a dozen reliable, some even unique, plant genetic systems that can increase the scope and effectiveness of chemical and physical mutagen screening and monitoring procedures. Some of these should be included in the Tier II tests. Moreover, plants are the only systems now in use as monitors of genetic effects caused by polluted atmosphere and water and by pesticides. There are several major advantages of the plant test systems which relate to their reproductive nature, easy culture and growth habits that should be considered in mutagen screening and monitoring. In addition to these advantages, the major plant test systems exhibit numerous genetic and chromosome changes for determining the effects of mutagens. Some of these have not yet been detected in other nonmammalian and mammalian test systems, but probably occur in the human organism. Plants have played major roles in various aspects of mutagenesis research, primarily in mutagen screening (detection and verification of mutagenic activity), mutagen monitoring, and determining mutagen effects and mechanisms of mutagen action. They have played lesser roles in quantification of mutagenic activity and understanding the nature of induced mutations.Mutagen monitoring with plants, especially in situ on land or in water, will help determine potential genetic hazards of air and water pollutants and protect the genetic purity of crop plants and the purity of the food supply. The Tradescantia stamen-hair system is used in a mobile laboratory for determining the genetic effects of industrial and automobile pollution in a number of sites in the U.S.A. The fern is employed for monitoring genetic effects of water pollution in the Eastern states. The maize pollen system and certain weeds have monitored genetic effects of pesticides. Several other systems that have considerable value and should be developed and more widely used in mutagen monitoring and screening, especially for in situ monitoring, are discussed. Emphasis is placed on pollen systems in which changes in pollen structure, chemistry, and chromosomes can be scored for monitoring; and screening systems which can record low levels of genetic effects as well as provide information on the nature of induced mutations. THE VALUE OF PLANT SYSTEMS FOR MONITORING AND SCREENING MUTAGENS CAN BE IMPROVED BY: greater knowledge of plant cell processes at the molecular and ultrastructural levels; relating these processes to mutagen effects and plant cell responses; improving current systems for increased sensitivity, ease of detecting genetic and chromosome changes, recording of data (including automation), and for extending the range of genetic and chromosome end points; and designing and developing new systems with the aid of previous and current botanical and genetic knowledge.
Acceleration patterns of the fetal heart rate, or a normal heart rate during spontaneous contractions, were used as a short weekly screening test to evaluate fetal well-being in 1102 high-risk pregnancies. When accelerations or contractions were absent during the initial screening, oxytocin was administered to stimulate uterine contractions. The mean duration of the antenatal monitoring was 18.5 min when the initial antenatal monitoring was normal, but 38.8 min when the initial results were uncertain. Oxytocin was administered to 38% of patients. This reduced the number of occasions where the diagnosis was uncertain from 46.6% to 12%. Patients with uncertain antenatal fetal monitoring had significantly more late decelerations during labor as well as newborns with low Apgar scores when compared to those with normal antenatal monitoring. Patients with abnormal antenatal monitoring (positive stress test) had significantly more low 5-min Apgar scores, late decelerations during labor and growth-retarded infants than the patients with normal antenatal fetal monitoring. Only 1 intrauterine death occurred within 7 days of a normal antenatal heart rate recording. No preventable fetal deaths occurred when antenatal monitoring demonstrated an acceleration pattern of the fetal heart rate.
A controlled prospective study of the differential effects of intrapartum fetal monitoring on mothers and infants has been conducted at Denver General Hospital, Denver, Colorado. A total of 690 high-risk obstetric patients in labor were randomly assigned to one of three monitoring groups--auscultation, electronic fetal monitoring alone, or electronic monitoring with the option to scalp sample. There were no differences in immediate infant outcomes in any measured category (Apgar scores, cord blood gases, neonatal death, neonatal morbidity, nursery course) among the three groups. There were no differences in rates of infant or maternal infections. The cesarean section rate was markedly increased in the electronically monitored groups, especially in the electronically monitored alone (18%) as compared with the auscultated (6%) (P less than 0.005). In this controlled trial electronic monitoring did not improve neonatal outcomes and the mothers were at increased risk of cesarean section.
The plasma hormonal patterns of the normal menstrual cycle have been reviewed. A consistent cyclic pattern of plasma hormone levels is observed in LH, FSH, estrogens, and progestins in the menstrual cycle. Other plasma hormones, such as ACTH, growth hormone, TSH, and PRL, as well as androgens and corticosteroids, fluctuate throughout the menstrual cycle without any consistent pattern during the ovulatory cycle. FSH, LH, E2, E1, P, T, and A levels during the induced ovulatory cycle are presneted for comparison. In the gonadotropin-induced ovulatory cycle most hormones behave in a manner similar to that in the normal ovulatory cycle, except for FSH levels, which rise continuously throughout the follicular phase of the cycle. Following ovulation in the gonadotropin-induced cycle, T rises above normal levels. Early in the clomiphene-induced ovulatory cycle, unlike the normal cycle, LH is distinctly elevated. Levels of both LH and FSH in the rest of the cycle simulate those in the normal cycle. However, T and A levels rise from the very beginning of clomiphene therapy and continue to rise throughout the clomiphene-induced ovulatory cycle. Levels of E and P are higher than in the normal ovulatory cycle, but a similar pattern is preserved. Because of the potential dangers of gonadotropin therapy, monitoring by frequent examination and laboratory tests is required. E monitoring is mandatory to evaluate follicular maturation, to time hCG administration, and to minimize hyperstimulation. Cervical mucus is an unreliable parameter for monitoring gonadotropin therapy alone. In addition to cervical mucus, plasma or urinary E should be monitored regularly. Clomiphene therapy is less dangerous than gonadotropin therapy. Because of its lesser risk, monitoring is rarely performed during clomiphene use. An active monitoring approach has been described. While this approach may not necessarily improve the outcome of clomiphene therapy, it may hasten the process of selecting the appropriate dose. Although other ovulation-inducing agents are available, their use is rarely associated with serious medical complications, and monitoring would seem unnecessary.
Open-heart surgery has entered the third decade of its existence. The period has demonstrated increased patient safety during and after open-heart surgery due to the employment of simple and reliable monitoring techniques. The monitoring of the function of the brain has not kept pace with these advances. Electroencephalographic (EEG) method is impractical for routine use in the operating room and in the intensive care unit. The cerebral function monitor (CFM) offers simplified continuous monitoring and interpretation of cerebral electrical activity (integrated EEG) in the clinical situation. The unit displays a two channel tracing, one representing cerebral activity and a second indicating electrode impedance artefacts. The early changes seen in addition to other conventional monitoring of the electrocardiogram, blood pressures, pulse rate, etc. offers information especially pertinent to open-heart surgery. It would appear that there is a place in anesthetic practice during and after cardiopulmonary bypass for the routine use of the CFM to supplement existing monitoring for the safer conduct of open-heart surgery. This study analyzes the value of a cerebral function monitor in 112 patients undergoing open-heart surgery.
A plea is made for continuous electronic monitoring of every patient undergoing an anesthetic. Such monitoring is far superior to clinical observation by means of the natural sensors. A continuous record of the vital phenomena is indispensable. Routine monitoring of the following is advised: ECG, heart rate, capnogram, plethysmogram, temperature, oxygen percentage and indirect blood pressure. Big operations demand central venous pressure and direct blood pressure monitoring, in addition. In the Institute of Anesthesiology in Utrecht all electronic monitors are built into a single unit which is used during every anesthetic. Capnography it dealt with in some detail and its value as a universal monitor demonstrated. The routine use of electronic monitors improves the quality of anesthesia and increases the safety of the patient.
Conventional methods of monitoring arrhythmias impose heavy demands on staff and are unreliable. On-line arrhythmia computers have been developed to overcome these problems, but there has been no critical evaluation of the functioning of such a system in a clinical setting. A comparison was made of the efficacy of two methods of monitoring in detecting arrhythmias in sixty-four patients in a coronary-care unit. Half the patients were monitored by a commercially available arrhythmia computer; the other half were monitored by conventional means with a rate-triggered alarm system. More than 99 percent of episodes of potentially serious ventricular arrhythmias were detected by the computer; 95 percent of patients with these arrhythmias were treated immediately. In those monitored by conventional means, a large proporation of such arrhythmias were unrecognised: only 17 percent of affected patients received immediate antiarrhythmic therapy. In 30 percent, treatment was delayed for several hours, and none was given in 52 percent. False alarms occurred with both systems but were more readily recognised as such in the computer-monitored patients. It is concluded that an arrhythmia computer improves the standards of arrhythmia detection, leads to quicker institution of treatment, and diminishes the demand on skilled staff.