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41.
A quantitative model is presented which accurately reproduces the time activity curve of the human left ventricular blood pool. Four parameters receive numerical values and may be of clinical value. 相似文献
42.
This intervention study compares the effectiveness of two approaches on caregiving stress reduction. Caregivers' psychobiological symptom experience and coping were profiled over time by identifying the types of stress-related symptoms most frequently experienced. Following pretesting (and selected matching procedures) using family functioning, coping, stress and mental status instruments, random assignment of caregivers was made to one of four groups: educative/didactic, psychotherapeutic/support, placebo, or control. Patients were tested at the end of eight weekly 2-hour sessions and again at 1-, 3-, 6-, and 12-month intervals after treatment. Although both the educative and psychotherapeutic groups were effective interventions for the reduction of strain, the psychotherapeutic/support group was the most effective over time, both at posttest and at the 3-month intervals. Neither group intervention was more effective than the control groups in reducing other types of stress, including anxiety, somatization, or depression. The psychobiological symptoms experienced by caregivers peaked at crisis periods in the caregiving trajectory, or when multiple demands were made of the caregiver during any one point in time. 相似文献
43.
44.
Susan Kirk MSc BNurs RGN RM RHV DNCert Caroline Carlisle MSc BA RGN RM DNCert DipCouns RNT Karen A. Luker PhD BNurs RGN RHV DNCert 《Journal of advanced nursing》1997,26(5):1036-1044
A national study was conducted between 1991 and 1994 to explore and describe the changing role of the nurse teacher following the introduction of Project 2000 pre-registration nursing courses. Multiple methods were used to collect data from a wide variety of respondents (nurse teachers, midwife teachers, clinical nurses, health service managers and higher education lecturers). This paper presents the findings relating to the impact of Project 2000 and the move into higher education on the continuing educational needs of nurse teachers. Views on college strategies for staff development, the changing nature of teachers'academic and professional development needs and the problems of the conflicting demands experienced are reported. The research highlights the need for clinical credibility to be clearly defined in relation to nurse teachers and for educational institutions to place more emphasis on teachers'clinical development if the rhetoric of policy is to become a reality. 相似文献
45.
Periodic breathing cycle duration (PCD), the time interval from the beginning of one respiratory pause to the beginning of the next pause within an episode of periodic breathing (PB), was measured by examination of 24-h impedance pneumograms in 51 preterm infants. Calculations of the SD of PCD within a given PB episode (approximately 3 s) and comparison of PCD values between two PB episodes in each infant (r = 0.68) revealed considerable variability in PCD. This variability was not related to the number of cycles in the PB episode or to the amount of PB in the recording. Contrary to the decrease in PCD from 15.0 s at 1 wk to 12.4 s at 12 wk in term infants reported previously, PCD did not vary as a function of postconceptional, gestational, or postnatal age in our preterm population. PCD has limited value as an indicator of chemoreceptor maturation in the preterm infant, and most likely reflects transient adjustments in respiratory system control. 相似文献
46.
Proteinuria in IgA nephropathy 总被引:4,自引:0,他引:4
Clinicopathological data in 74 patients with IgA nephropathy were analyzed with special attention to level of proteinuria and its prognostic significance in this disease. Excretion rates exceeding 3 g per day (heavy), in the range of 1 to 2.9 g (moderate) and under 1 g per day (mild) each occurred in approximately equal proportions of patients. One-sixth of those with more than 1 g developed end-stage renal failure, while serum creatinine never exceeded 2 mg/dl in any with mild proteinuria. "Renal survival" (serum creatinine of 2 mg/dl or less) at five years after presentation was 100% in patients with persistently mild proteinuria, 87% in those whose protein excretion reached the moderate range, and 69% when heavy or nephrotic range proteinuria developed. Of significance, only rarely did mild proteinuria at presentation increase to higher levels. A correlation existed between level of protein excretion and severity of mesangial, segmental or global proliferation, glomerulosclerosis, podocyte effacement, interstitial infiltration, tubular atrophy and vascular sclerosis, even in patients with unimpaired renal function. Moderate or heavy proteinuria typically preceded the onset of hypertension and occurred prior to the development of renal insufficiency. Our results underscore magnitude of proteinuria as an early marker of glomerular damage in the prognosis of IgA nephropathy. 相似文献
47.
Histamine is known to cause a substantial increase in the permeability of venules to both water and proteins. However, this increase is transient, i.e., the initially elevated permeability returns toward control levels, or "recovers," even during continuous histamine stimulation. In this investigation, we attempted to identify the possible chemical signal(s) initiating the permeability recovery process in single venules of rat mesentery. Specifically, we tested whether histamine's binding to H2 receptors and/or the production of prostacyclin by endothelial cells was involved in this process. To achieve this aim, the time course of endothelial cells was involved in this process. To achieve this aim, the time course of histamine-induced changes in permeability to alpha-lactalbumin was measured in the presence of H2 receptor antagonist (cimetidine) or of prostacyclin synthetase inhibitor (tranylcypromine), respectively. Permeability of individually perfused microvessels was measured using fluorescence microscopy. The results demonstrated that permeability recovery was not affected by the H2 receptor antagonist but was suppressed or even abolished by the prostacyclin synthesis inhibitor. Therefore, these results suggest that the production of prostacyclin by endothelial cells might serve as one chemical signal to initiate the permeability recovery process, whereas histamine's binding to H2 receptors is not involved in this phenomenon. 相似文献
48.
Baldwin RT Radovancević B Duncan JM Wampler RK Frazier OH 《Texas Heart Institute journal / from the Texas Heart Institute of St. Luke's Episcopal Hospital, Texas Children's Hospital》1992,19(2):81-86
The Hemopump Cardiac Assist System is a relatively new intraarterial, axial-flow circulatory assist device that offers temporary left ventricular support to patients in refractory cardiogenic shock, without requiring major surgery for insertion. Use of the Hemopump is associated with a low complication rate. Device-related morbidity is extremely rare. Because the Hemopump is safe for use in community hospitals, the number of patients supported by this device is expected to increase. In this report, we present general guidelines for the care of patients supported by the Hemopump. We describe techniques for the management of afterload reduction, supravalvular dislodgement, device malfunction, ventricular ectopy, intracardiac shunting, and inflow cannula obstruction. 相似文献
49.
Caffeine-induced anxiogenesis: the role of adenosine, benzodiazepine and noradrenergic receptors 总被引:1,自引:0,他引:1
The purpose of this study was to determine the mechanism by which caffeine increases anxiety. Rats were tested in the social interaction test of anxiety after administration of caffeine (20 or 40 mg/kg) alone or in combination with various compounds. In order to investigate the role of adenosine receptors, caffeine was given in combination with 2-chloroadenosine (0.1 and 1 mg/kg). To investigate the role of benzodiazepine receptors, chlordiazepoxide (5 mg/kg), a benzodiazepine antagonist, flumazenil (RO 15-1788, 1 and 10 mg/kg) and a triazolobenzodiazepine U-43,465 (32 mg/kg) were used. Finally, an alpha 2-receptor agonist, clonidine (0.1 and 0.025 mg/kg) and a beta-adrenoceptor antagonist, DL-propranolol (5 mg/kg), were used to study the role of noradrenergic systems in the effects of caffeine. Caffeine (20 and 40 mg/kg) reduced the time spent in social interaction and this effect was antagonized by chlordiazepoxide, U-43,465 and DL-propranolol, but not by flumazenil, 2-chloroadenosine or clonidine. It was therefore concluded that the anxiogenic effect of caffeine was unlikely to be due to its effects at adenosine or benzodiazepine receptors. It is suggested that the reversal of caffeine's effects by chordiazepoxide may have been "functional," i.e., merely a cancellation of two opposite effects. It is discussed whether the reversal of caffeine's effects by propranolol and U-43,465 are functional, or reflect a noradrenergic site of action. 相似文献
50.
MIA SON JEONG‐OK KONG SANG‐BAEK KOH JAEYOUNG KIM MIKKO HÄRMÄ 《Journal of sleep research》2008,17(4):385-394
We investigated the effects of 12‐hour shift work for five to seven consecutive days and overtime on the prevalence of severe sleepiness in the automobile industry in Korea. [Correction added after online publication 28 Nov: Opening sentence of the summary has been rephrased for better clarity.] A total of 288 randomly selected male workers from two automobile factories were selected and investigated using questionnaires and sleep‐wake diaries in South Korea. The prevalence of severe sleepiness at work [i.e. Karolinska Sleepiness Scale (KSS) score of 7 or higher] was modeled using marginal logistic regression and included theoretical risk factors related to working hours and potential confounding factors related to socio‐economic status, work demands, and health behaviors. Factors related to working hours increased the risk for severe sleepiness at the end of the shift in the following order: the night shift [odds ratio (OR): 4.7; 95% confidence interval (CI): 3.6–6.0)], daily overtime (OR: 2.2; 95% CI: 1.7–2.9), weekly overtime (OR: 1.6; 95% CI: 1.0–2.6), and night overtime (OR: 1.6; 95% CI: 0.8–3.0). Long working hours and shift work had a significant interactive effect for severe sleepiness at work. Night shift workers who worked for 12 h or more a day were exposed to a risk of severe sleepiness that was 7.5 times greater than day shift workers who worked less than 11 h. Night shifts and long working hours were the main risk factors for severe sleepiness among automobile factory workers in Korea. Night shifts and long working hours have a high degree of interactive effects resulting in severe sleepiness at work, which highlight the need for immediate measures to address these characteristics among South Korean labor force patterns. 相似文献