Sleep behaviors and attitudes among internal medicine housestaff in a U.S. university-based residency program.

PURPOSE: Physicians-in-training are susceptible to fatigue given their prolonged duty hours. Sleep deprivation has been shown to alter perceptions of sleepiness and performance. This study examined the state of sleepiness and attitudes about sleep and performance of work- and non-work-related tasks among incoming and current housestaff; and how rotation, call cycle, and call status are related to acute and chronic sleep deprivation and perceptions of sleepiness. METHOD: A survey instrument was administered in June 2001 to 53 incoming interns and 79 current housestaff at the University Pennsylvania School of Medicine, a university-based internal medicine residency program. RESULTS: All 132 participants (100%) completed the instrument. Acute sleep deprivation was experienced by 34% of the current housestaff and 64% of current housestaff were chronically sleep deprived. Current housestaff admitted to the possibility of dozing while performing various work-related tasks such as writing notes in charts (69%), reviewing medication lists (61%), interpreting labs (51%), and writing orders (46%). At least half of all respondents felt their patients received good care despite residents' sleepiness and as many believed sleep deprivation was a necessary part of training. Nearly half (48%) of current housestaff rotating on a ward service reported acute sleep deprivation, as did 81% of those who were postcall. Over two-thirds of the housestaff on wards and in the ICU reported chronic sleep deprivation. Subjective sleepiness did not vary much across rotations, call cycle, and call status. CONCLUSION: Chronic and acute sleep deprivation contribute to residents' fatigue. Education could be targeted at attitudes. Further investigation of factors contributing to chronic sleep deprivation in this population is warranted.     

An attempt to analyze lethal outcomes]

The results of the analysis of 2675 autopsy protocols for 1987-1990 in the Moscow City Pathology Centre and 18246 cases of surgery of patients with urgent abdominal pathology in the Ostroumov's Hospital N 33 for 1980-1989 (with 870 lethal issues) are presented. Over 62% of the total are patients over 75 years of age. The advanced age, the presence of multiple diseases (polypathies) considerably influenced the course, diagnosis, therapy and issues of diseases, particularly in the urgent surgical pathology. This is considered particularly in the urgent surgical pathology. This is considered in details on the example of the gallbladder stones. The frequency of different variants of ischemic cardiac disease, vascular brain damage, malignant tumours, respiratory diseases, diseases of the digestive and urinary tract is presented. Clinical diagnosis in cases of death at home is discussed.     

Hydration level is an internal variable for computing motivation to obtain water rewards in monkeys

In the process of motivation to engage in a behavior, valuation of the expected outcome is comprised of not only external variables (i.e., incentives) but also internal variables (i.e., drive). However, the exact neural mechanism that integrates these variables for the computation of motivational value remains unclear. Besides, the signal of physiological needs, which serves as the primary internal variable for this computation, remains to be identified. Concerning fluid rewards, the osmolality level, one of the physiological indices for the level of thirst, may be an internal variable for valuation, since an increase in the osmolality level induces drinking behavior. Here, to examine the relationship between osmolality and the motivational value of a water reward, we repeatedly measured the blood osmolality level, while 2 monkeys continuously performed an instrumental task until they spontaneously stopped. We found that, as the total amount of water earned increased, the osmolality level progressively decreased (i.e., the hydration level increased) in an individual-dependent manner. There was a significant negative correlation between the error rate of the task (the proportion of trials with low motivation) and the osmolality level. We also found that the increase in the error rate with reward accumulation can be well explained by a formula describing the changes in the osmolality level. These results provide a biologically supported computational formula for the motivational value of a water reward that depends on the hydration level, enabling us to identify the neural mechanism that integrates internal and external variables.     

An integrated residency in internal and preventive medicine.

The importance of preventive and population-based principles in clinical practice is widely acknowledged. The challenge of imparting these principles in either undergraduate or postgraduate medical education has, however, not been fully met. The necessary skills are provided comprehensively by preventive medicine residency programs, but at the expense of clinical training. Sequential residencies in primary care and preventive medicine, the currently available means of obtaining thorough preparation in both clinical and population-based principles, represent an inefficient, generally unappealing, and non-integrated approach. In response to these concerns, and in an effort to make preventive medicine training appeal to a wider audience, the authors developed and implemented a residency program fully integrating internal and preventive medicine. The program meets, and generally exceeds, the requirements of both specialty boards over a four-year period. The program provides extensive training in clinical, preventive, and public health skills, along with case management and cost-effective care, conferring the MPH degree and leading to dual board eligibility. The model is ideally wed to the demands of the modern health care environment in the United States, is extremely attractive to applicants, and may warrant replication both to train academic and administrative leaders and to raise the standards of preventive and public health practice in primary care.     

An attempt to analyse colour reception by electrophysiology

1. The problem of colour reception is that we do not know the action spectra of the visual pigments involved, the nature of the signals generated nor the interaction between these signals. We only know the incident light and the electric results of interaction.2. In Part 1 we show that S-potentials from red/green (R/G) units saturated with deep red light show this property: added green light pulls down the ceiling of depolarization, but more added red had no power to raise it again. Thus lights that depress the deep red ceiling equally stimulate the green pigment equally. From this the action spectrum of the green pigment can be obtained.3. If we assume that only two visual pigments are involved in the R/G unit, and that lights which do not pull down the deep red ceiling are below the threshold for green cones, then in this range only the red pigment is excited and we may obtain its action spectrum. Its maximum is at 680 nm where no visual pigment so far has been found.4. In Part 2 we consider the following mathematical problem: ;Is it possible that two pigments of given action spectra could combine their outputs in such a way that the resultant would be identical with the output of a third pigment of given action spectrum, for every intensity of every monochromatic light?' The solution shows that this is always mathematically possible, and the necessary interaction function is deduced.5. It is shown further that if the log action spectra are the ;visual parabolas' that resemble Dartnall's nomogram, then the interaction function is simply a linear transform such as Hartline & Ratliff (1957) have found with lateral inhibition in Limulus and Donner & Rushton (1959) with silent substitution in the frog.6. An interaction that matches a single pigment to perfection for all monochromatic lights will not match it for certain mixtures. By this criterion the 680 nm excitability is a pigment and not the resultant of two other pigments, i.e. pigments more excitable in other spectral regions.7. In Part 3 monochromatic lights are matched by red+green mixtures that give identical responses. From this the action spectrum of the red pigment may be obtained without involving nerve organization (except as a null detector). The result, which has one arbitrary constant, is given by the curves of Fig. 10, the continuous curve R or one of the dotted curves. Of these only curve R is acceptable.8. Knowing the action spectra for red and green cones we may consider what signals are generated and how they interact to give the records. Figure 11 suggests a model that will account for the size and sign of S-potentials as function of the quantum catch by the two pigments. It does not embrace the time or space parameters which can be very complex.     

An attempt to construct the Sensation Seeking Scale-Abstract Expression

The purpose of this study is to construct Sensation Seeking Scale-Abstract Expression (SSS-AE), consisting of 15 items. All items were described in relatively abstract terms. Data were collected from Japanese college students (246 males and 121 females). The total SSS-AE scores had positive correlation with the general factor of sensation seeking. This confirms the validity of the SSS-AE proposed in this study. From the factor analysis of the items, three factors were extracted: Thrill and Adventure Seeking (TAS), Disinhibition (Dis), and Experience Seeking (ES). But Boredom Susceptibility (BS) was not confirmed. These results were discussed in comparison with the factors reported by Zuckerman. Males showed higher ES scores than females, but females showed higher Dis scores than males.     

An attempt to improve classification of HCV-correlated chronic hepatitis

To verify the clinical efficacy of the Desmet classification of chronic hepatitis C we reviewed 801 liver biopsies from patients with HCV-chronic hepatitis (CH). The diagnosis of chronic hepatitis was assessed according to the Desmet classification based on the Knodell Histological Activity Index (HAI) (minimal CH=score 1-3; mild CH= 4-8; moderate CH= 9-12; severe CH= 13-18). Liver fibrosis was assessed according to the Scheuer scoring system. One hundred forty-eight patients had cirrhosis and 653 CH. Of these 653, according to the Desmet classification 145 patients showed minimal, 424 mild, 73 moderate and 11 severe chronic hepatitis. Since the classification underestimated the moderate and severe forms of HCV-related chronic hepatitis, we evaluated the possibility of improving the Desmet classification of chronic hepatitis C using our classification: minimal CH= score 1-3; mild CH= 4-6; moderate CH= 7-8; severe CH= 9-18. According to our classification 145 showed minimal CH, 363 mild CH, 61 moderate CH and 84 severe CH. All the 61 patients who crossed over from mild CH under the Desmet to moderate CH under our classification showed a periportal inflammation of grade 3, and all the 73 patients but 8 who crossed over from moderate to severe showed a grade of periportal inflammation higher than 3. The Desmet classification of HCV-related chronic hepatitis underestimated the severe forms of HCV-CH, while our classification seems to be suitable also for chronic hepatitis C.     

An attempt to produce automatism in a spinal center

Summary Experiments were conducted on frog spinal cord center with the creation of conditions for its activity analogous to those for the frog respiratory center activity. For this purpose one of the nerves was stimulated for a prolonged period, thus creating a background lengthy optimal excitation in the spinal cord nervous centers: then the synergetic nerve was subjected to periodical brief stimulation which led to a transitory depression of the initial excitation. In another series of experiments an attempt was made at inhibition of the initial central excitation from the same contralateral nerve. The main principles, governing conditions of activity of some automatically working centers (particularly of the frog respiratory center), were disclosed, permitting it to be modelled in other nonautomatic centers.(Presented by Active Member AMN SSSR A. V. Lebedinskii) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 54, No. 10, pp. 13–17, October, 1962.