The analysis of benefit and risk of combined pancreatic and renal transplantation versus renal transplantation alone

Currently, diabetes mellitus is the most common cause of renal failure in adults. However, combined pancreatic and renal transplantation (PRT) remains controversial when compared with renal transplantation alone (RTA) in diabetic recipients. We analyzed the results and morbidity in four age-matched groups--31 patients with Type I diabetes undergoing PRT before dialysis, 30 patients with diabetes who are dependent of dialysis undergoing PRT, 31 concurrent and historic patients with Type I diabetes undergoing RTA and 31 concurrent patients without diabetes undergoing RTA. All patients received cadaver donor organs and were managed with cyclosporine and prednisone immunosuppression with selective OKT3 induction. The four groups were comparable with respect to age, weight, gender, duration and severity of diabetes, dialysis type, number of retransplants, degree of sensitization, preservation time and matching. The groups differed with regard to duration of dialysis and period of follow-up evaluation, pretransplant blood transfusions, racial distribution and OKT3 induction therapy. PRT was associated with a greater morbidity rate as evidenced by a slightly higher incidence of rejection, infections and reoperations. The number of readmissions and hospitalization period during the first 12 months was also greater after PRT versus RTA. However, none of these differences were significant. No detrimental effect was noted on renal allograft function at one year; patient and graft survival was actually higher in the PRT groups. Quality of life was improved in nearly 90 percent of PRT recipients. Although the improved results after PRT may be attributed to selection bias, only lesser differences were noted among the four study groups. The aforementioned data suggest that appropriate patient selection can overcome the morbidity associated with PRT, resulting in excellent patient and graft survival with the potential for complete rehabilitation.

Comparative polysomnographic study of narcolepsy and idiopathic central nervous system hypersomnia

Patients with a primary diagnosis of narcolepsy or idiopathic CNS hypersomnia seen at Stanford University Sleep Disorders Clinic over a 5-year period were studied retrospectively. The two patient groups were compared with respect to blood pressure, Minnesota Multiphasic Personality Inventory (MMPI) psychological profile, nocturnal sleep structure, prevalence and severity of sleep apnea and periodic leg movements in sleep, and daytime sleep tendency. Narcoleptic patients tended to have higher blood pressure, higher prevalence of abnormally elevated MMPI scores, more abbreviated and more disrupted sleep at night, and greater daytime sleep tendency. Sleep apnea and periodic leg movements were more prevalent in narcoleptic patients, but only periodic leg movements in sleep were more prevalent in narcoleptic patients than in the general population. Periodic leg movements during REM sleep were observed in more than one-third of narcoleptic patients, which may be an important pathophysiologic feature of this disorder.

Muscarinic cholinergic receptors and the canine model of narcolepsy

The role of the muscarinic cholinergic receptor in narcolepsy was examined using radioligand binding to various brain regions of normal and genetically narcoleptic Doberman pinschers. In this multi-litter study, a previous report of a proliferation of muscarinic cholinergic receptors in the brainstem was confirmed, and the concentration of the M2 receptor subtype, in particular, was elevated. This up-regulation of brainstem cholinergic receptors suggests a problem with release of acetylcholine, which, together with previous reports of an impairment of dopamine release, may be indicative of a fundamental membrane problem in narcolepsy.

Circadian timekeeping in narcoleptic dogs

Anatomical and functional aspects of the circadian timekeeping system containing the suprachiasmatic nucleus (SCN) were compared in normal and genetically narcoleptic dogs. The retinohypothalamic tract was delineated by tritiated amino acid autoradiography, the SCN was identified and examined by morphological techniques, and the circadian rhythm of melatonin concentrations in cerebrospinal fluid was measured by radioimmunoassay. Results suggest that the retinal input, cytoarchitecture, and essential timekeeping function of the SCN are intact in narcoleptic dogs.

Sleep apnea disorders. Introduction to sleep and sleep disorders

This overview of normal and disordered sleep introduces techniques for recording and classifying sleep stages, physiological and temporal characteristics of sleep, age-related changes in sleep, consequences of sleep deprivation, theories on the function of sleep, and neurophysiological and biochemical mechanisms regulating sleep. Various categories of sleep disorders are briefly surveyed, with special emphasis on differential diagnosis of sleep apnea syndromes and other disorders characterized by symptoms of excessive daytime somnolence.

Electroencephalographic correlates of cataplectic attacks in narcoleptic canines

Cataplectic attacks were monitored behaviorally and polygraphically in 4 narcoleptic dogs, of which three inherited the disorder. The recorded EEG signals were evaluated by power spectral analysis. We found 3 distinct stages of cataplexy: an initial stage which resembled wakefulness with tonic suppression of EMG activity, a later stage which was highly similar to REM sleep, and a final transitional stage to wakefulness or NREM sleep. The first stage of cataplexy was characterized by full postural collapse, a waking-like EEG spectrum, visual tracking, and a hypotonic EMG. The second stage of cataplexy differed electrographically from the previous stage by the onset of hypersynchronous hippocampal theta activity, a REM-like EEG spectrum, larger amplitude EEG signals, and a higher peak theta frequency. Glazed eyes, sporadic rapid eye movements and muscle twitches were also present. The final stage of cataplexy was characterized by mixed amplitude, mixed frequency EEG activity, and by the absence of rapid eye movements, visual tracking, directed movements, and muscle twitches. The EEG spectra of two other narcoleptic phenomena, sleep-onset REM periods and NREM sleep onsets from cataplexy, were nearly identical to the spectra of the normally occurring REM and NREM sleep periods.

Sleep-wakefulness patterns in the aged cat

This investigation compared the 24 h sleep-wake characteristics of young adult (2-4 years) and old (10-11 years) cats in order to determine whether there were significant age- and/or gender-related differences. Aged animals had more brief (6-14 sec) awakenings, less REM sleep, and more NREM sleep than young adults. There were no significant age- or gender-related differences with respect to either the daily numbers or the mean durations of sleep and waking episodes. Compared with the young adults, aged males had substantially less DSWS and fewer numbers of short-duration (less than or equal to 2.5 min) LSWS bouts. Both males and females showed age-related differences with respect to the sequencing of state-patterns. The expression of these patterns in relation to time of day was comparable for young and old animals. Overall, these findings compare favorably with those commonly reported in the elderly human.

Rapid eye movement sleep and its relationship to feeding behavior in the adult cat

The aim of this study was to corroborate a previous report that, in cats kept on a 12:12-hr light-dark schedule, there is a highly significant negative correlation between the quantity of REM sleep in a 12-hr period and food intake in the subsequent 12-hr interval. Analyses of sleep-wake and food intake measures from freely behaving adult cats failed to disclose any consistent correlations between food consumption and REM sleep quantities in the same or adjacent 12-hr periods; amounts of waking (or total sleep) and slow-wave sleep also showed no consistent relationship to food intake. These findings question assertions that REM sleep participates directly in regulating the expression of motivated behaviors.

Narcolepsy: cholinergic receptor changes in an animal model

An inbred colony of narcoleptic doberman pinschers has been analyzed for muscarinic receptor levels in 19 discrete brain regions. In comparison to age-matched controls, receptors were generally elevated in the brainstem and reduced in forebrain areas. No changes in receptor binding affinity were detected. The increased receptor levels found in the brainstem suggest that cholinoceptive neurons in this region are hypersensitive and may be involved in the initiation of cataplexy and other aspects of the narcolepsy syndrome.

Narcolepsy: biogenic amine deficits in an animal model

Concentrations of biogenic amine metabolites in discrete brain areas differed significantly between dogs with genetically transmitted narcolepsy and age- and breed-matched controls. Dopamine and 3,4-dihydroxyphenylacetic acid were consistently elevated in the brains of narcoleptic animals, while homovanillic acid was not. Narcoleptic animals consistently exhibited lower utilization of dopamine and higher intraneuronal degradation of dopamine but no uniform decrease in serotonin utilization. Hence neuropathology appears to be associated with genetically transmitted canine narcolepsy. The data indicate a nonglobal depression of dopamine utilization or turnover or both.

Sleep-related apneic and apneustic breathing following pneumotaxic lesion and vagotomy

Sleep-wakefulness state was found to be a crucial determinant of respiratory pattern in chronic cats with bilateral lesions of the rostral pontine pneumotaxic complex (PC). Lesions resulted in increased TE, TI, and VT in all sleep and waking states. Several state-specific respiratory effects were also observed: (1) comparatively eupneic breathing during alert wakefulness (WI); (2) greatly increased TE in slow wave sleep (SWS); (3) decreased TE during rapid eye movement sleep (REM), relative to SWS; (4) increased tendency for prolonged TI (brief apneusis) during REM. Bilateral vagotomy at 2-5 weeks after PC lesion exaggerated these effects and caused distinct apneusis during REM. The results confirm that the PC is not essential for the occurrence of either rhythmic breathing or for expression of state changes in respiration, although the effects of the PC on breathing in the intact cat may vary as a function of sleep-wakefulness state. It is suggested that other regulatory systems that influence the central respiratory rhythm generator (RRG) are similarly modulated by state, and that variations in respiratory pattern observed following PC lesion and vagotomy are the result of state-dependent changes in the balance between multiple inputs to the RRG.

Sleep-waking patterns in hypoxic kittens

Kittens at 10, 20, and 40 days of age were made intermittently hypoxic in 10 or 7% oxygen chambers for either 3 or 8 days. Respiration, EKG, EEG, and neck and eye movements were recorded during hypoxia. Compared to 21% oxygen controls, hypoxic kittens had fewer and shorter epochs of active sleep, and longer epochs of quiet sleep. Some hypoxic kittens exhibited slow and labored respiration during quiet sleep and transitional epochs, which reversed during active sleep. Kittens that showed most pronounced respiratory changes or died had less active sleep than kittens that compensated adequately and survived. These results suggest that active sleep may be important for stimulation of respiration during infancy. Suppression of active sleep, augmentation of quiet sleep, or other disturbances to normal sleep-waking patterns during hypoxia, may increase the risk for hypoxic respiratory depression and death.

Sleep apnea in hypoxic and normal kittens

Frequency and characteristics of apneas were studied in 10-, 20-, and 40-day old kittens during several days of exposure to 21%, 10%, or 7% oxygen atmospheres. Ninety-seven percent of all apneas occurred during sleep or at transitions between sleep and waking states. Hypoxic kittens, compared to controls, had greatly decreased apnea frequency, but other characteristics of apneas did not differ significantly. Apneas in both control and hypoxic kittens were normal, stereotyped events and were not considered to represent pathological processes. Evaluation of events preceding apneas indicated that a majority of apneas followed augmented breaths and/or brief arousals. We suggest that apnea, heart rate changes during apnea, and frequently concurrent transitions in sleep-waking state may be causally related to these pre-apnea events. The results of this study and a parallel study of human infants suggest that below-normal apnea frequency may indicate hypoxemia and may be associated with higher risk for Sudden Infant Death Syndrome.

Reversal of cardiopulmonary failure during active sleep in hypoxic kittens: implications for sudden infant death

Experimentally induced hypoxia in kittens precipitated episodes of depressed respiration and irregular cardiac function during quiet sleep, waking, and transitional states. The onset of active sleep stimulated both breathing and heart rate and decreased abnormal variability in these functions. However, hypoxia markedly reduced the proportion of active sleep. These data suggest that active sleep protects against respiratory and cardiac abnormalities in infants. Chronic hypoxemia or other factors that reduce active sleep in infants, including the normal developmental decrement in this state, may increase the risk of cardiopulmonary failure and death.

The dimensions of nonauthoritarianism

The converse of authoritarianism has not been conceptualized very clearly though scales purporting to measure nonauthoritarianism are among the most commonly used in. personality inventories. Using the Autonomy scale of the Omnibus Personality Inventory (a derivative of the original California F scale), as administered to a sample population of beck and white college freshmen, the dimensions of nonauthoritarianism were explored. A factor analysis of the scale creates three components (anti-authoritarianism, anti-conventionalism and open-mindedness) that are conceived of as successive phases in the weakening of authoritarianism. This phase hypothesis is supported with evidence from Guttman scales and a correlational analysis of how black and lower-class as compared to white and middle-class students shift from one phase to another over the course of the freshman year.