The Prospective Assessment of Autonomic Nerve Function by Pupillometry in Adolescents with Type 1 Diabetes Mellitus

The study aimed to compare the longitudinal assessment of autonomic nerve function by computerized infrared pupillometry and standard cardiovascular tests in adolescents with diabetes. Adolescents (n = 150) were assessed at two time points (T1 and T2). The median time interval between assessments was 1.5 (range 0.9–3) years. At T1 the median age was 14.5 (range 8.3–19.5) years and the median duration was 6.5 (range 1.1–16) years. The pupillary variables assessed included the resting pupil diameter, the maximum constriction velocity, and the reflex amplitude of constriction. Heart rate reflexes were assessed in response to deep breathing, the Valsalva manoeuvre, and on standing from a lying position (30/15 ratio). Between visits there was a significant decrease in maximum constriction velocity (6.0 mm s^?1 vs 6.3 mm s^?1, p = 0.0001) and resting pupil diameter (6.2 mm vs 6.3 mm, p = 0.001). At reassessment pupillary abnormalities increased from 32 (21 %) to 45 (30%), with 17 (54 %) of the initial abnormalities persisting. Adolescents with abnormally slow maximum constriction velocity compared to those with normal maximum constriction velocity had a higher glycated haemoglobin (HbA_1c%) at T2 (p = 0.02) and between assessments (p = 0.01). Cardiovascular test abnormalities did not increase between visits and the persistence of initial abnormalities was low (21 %). In summary, pupillometry appears a more sensitive test of autonomic nerve dysfunction in adolescents with diabetes than assessment of cardiovascular reflexes.     

Functional plasticity of microglia: a review

The present review summarizes recently acquired data in vivo, which support a role of CNS microglia as a source of defense cells in the CNS capable of carrying out certain immune functions autonomously. We have kept the following discussion restricted to microglial cells and have not included work on the immunological functions of astrocytes, which has been recently reviewed elsewhere (Fontana et al.: Immunological Reviews 137:3521-3527, 1987). Resting microglia are scattered uniformly throughout the CNS forming a network of potential immunoeffector cells, which can be activated by stimuli ranging from peripheral nerve injury over viral infections to direct mechanical brain trauma. The term "activated microglia" is used here to describe proliferating cells that demonstrate changes in their immunophenotype but have not undergone transformation into brain macrophages. Such a transformation can be stimulated by neuronal death but not by sublethal neuronal injury. Microglia may function as antigen-presenting cells and may thus represent the effector cell responsible for the recruitment of lymphocytes to the brain resulting in an inflammatory reaction. The recent developments in the understanding of microglial cell function may lead to a redefinition of the often cited "immune privilege" of the brain.     

Normal aging decreases regional homogeneity of the motor areas in the resting state

Our knowledge about aging modulation of the central motor system remains sparse and contradictory. In the current study, we used functional MRI (fMRI) to study the aging influence on regional homogeneity of the motor-related brain areas in the resting state. We found that regional homogeneity in extensive motor regions, like the cingulate motor area, cerebellum, primary motor cortex, premotor area, supplementary motor area, thalamus, globus pallidus and putamen was significantly decreased in aged subjects. Our study indicates that normal aging process may disrupt the function of motor areas in the resting state, which may contribute to the declined motor ability in aged population.     

Predicting Home and Work Blood Pressure Measurements from Resting Baselines and Laboratory Reactivity in Black and White Americans

The relationship between blood pressure in the laboratory (both at rest and in response to laboratory tasks) and ambulatory blood pressure at home and at work was evaluated. One hundred nineteen normotensive and unmedicated mild-moderate hypertensive black and white females and males participated in laboratory blood pressure monitoring at rest and during four challenging tasks (structured interview, video game, bicycle exercise, and cold pressor test) as well as ambulatory blood pressure monitoring while at home and at work. Baseline blood pressure taken while subjects were at rest was the strongest predictor of ambulatory systolic blood pressure (r = .64) and diastolic blood pressure (r = .77) at work. Among reactivity tasks the strongest predictors of ambulatory blood pressure in the total population were the structured interview and the video game (both psychological tasks) followed by the cold pressor test. Racial comparisons, however, determined that the cold pressor test predicted diastolic blood pressure significantly better for blacks (r = .73) than for whites (r = .40), suggesting a possible difference in blood pressure regulation.     

Psychometric Properties of Resting Anterior EEG Asymmetry: Temporal Stability and Internal Consistency

We examined whether resting anterior electroencephalographic (EEG) asymmetry in the alpha frequency band has psychometric properties that would be expected of a measure assessing individual differences. In each of two experimental sessions, separated by three weeks, resting EEG in midfrontal and anterior temporal sites was recorded from 85 female adults during eight 60-s baselines. Resting alpha asymmetry demonstrated acceptable test-retest stability and excellent internal consistency reliability. Analyses including other frequency bands indicated that degree of stability varied somewhat as a function of band and region. In addition, asymmetry was less stable than absolute power. Discussion focuses on the implications of the present findings for the measurement and conceptualization of resting anterior asymmetry.     

Morphological characteristics of the life cycle of resting cartilage cells in mouse rib investigated in intrasplenic isografts

Summary Resting cartilages taken from 2-day-old mouse ribs were transplanted into spleens in order to carry out morphological investigations of the life cycles of their chondrocytes. The explants were isografted for periods of up to 60 days and examined at light and electron microscopic levels, using von Kossa's reaction or osmium-potassium ferrocyanide (OPF) fixation. By day 3 after transplantation, resting cartilage containing immature chondrocytes was well adapted to splenic tissue and by 7 days after transplantation these chondrocytes had changed into early hypertrophic chondrocytes containing large vacuoles, glycogen aggregates and abundant secretory organelles. It was also demonstrated by von Kossa's reaction that the initial calcification occurred in the territorial matrix during this period. In spite of the hypertrophic chondrocytes in the central zone being surrounded by an extensively calcified matrix during days 14–21 after transplantation, these cells had well-preserved organized organelles, except that Golgi-associated elements and endoplasmic reticulum revealed a tendency toward degenerative changes. With increased duration of the grafting period, from 30–60 days, the calcification zone progressed gradually, and the number of hypertrophic chondrocytes embedded in the calcified matrix decreased considerably. By day 60, degenerating hypertrophic chondrocytes of two types were distinguished: flattened cells containing large vacuoles, poorly developed Golgi apparatuses, and rough endoplasmic reticulum; and shrunken dark cells displaying terminal hypertrophy. During the present study, we observed no vascular invasion into the calcified matrix, or appearance of bone-related cells, and the morphological changes from the resting chondrocytes to cellular hypertrophy accompanied by the formation of a calcified matrix were observed at day 60. These findings indicate that resting cartilage cells of the mouse have the capacity for terminal differentiation when transplanted into the spleen.     

Effects of 12 weeks of aerobic exercise plus dietary restriction on body composition,resting energy expenditure and aerobic fitness in mildly obese middle-aged women

This study investigated the effects of 12 weeks of aerobic exercise plus voluntary food restriction on the body composition, resting metabolic rate (RMR) and aerobic fitness of mildly obese middle-aged women. The subjects were randomly assigned to exercise/diet (n = 17) or control (n = 15) groups. The exercise/diet group participated in an aerobic training programme, 45–60 min · day ^–1 at 50%–60% of maximal oxygen uptake (VO_2max), 3–4 days · week^–1, and also adopted a self-regulated energy deficit relative to predicted energy requirements (–1.05 MJ · day ^–1 to –1.14 MJ · day ^–1 ). After the regimen had been followed for 12 weeks, the body mass of the subjects had decreased by an average of 4.5 kg, due mainly to fat loss, with little change of fat free mass (m _ff). The absolute RMR did not change, but the experimental group showed significant increases in the RMR per unit of body mass (10%) and the RMR per unit of m _ff (4%). The increase in RMR/m _ff was not correlated with any increase in VO_2max/m _ff. The resting heat production per unit of essential body mass increased by an average of 21%, but the resting heat production rate per unit of fat tissue mass remained unchanged. We concluded that aerobic exercise enhances the effect of moderate dietary restriction by augmenting the metabolic activity of lean tissue.     

武警某部女学员有氧耐力训练训练心率的研究

目的为指导和监控部队有氧耐力训练提供参考资料.方法对382名18～22岁女学员依照GJB1337-92和GJB2558-96规定的方法分别测定其安静心率和训练心率.结果安静心率均值为72.85±6.28b/min;按平均年龄21岁计算,中等训练心率为165.76±5.96b/min;最小训练心率为151.17±6.06b/min;最大训练心率为178.23±6.14b/min.结论女学员有氧耐力训练的适宜训练心率为151～178b/min.     

Ca2+ channel actions of the non-dihydropyridine Ca2+ channel antagonist Ro 40-5967 in vascular muscle cells cultured from dog coronary and saphenous arteries

Summary We studied the membrane effects of (1S,2S)-2-(2-[[3-2(benzimidazolyl) propyllmethylamino]ethyl)-6-fluoro-1,2,3,4-tetrahydro-l-isopropyl-2-naphthyl-methoxy-acetate dihydrochloride, Ro 40-5967, a new non-dihydropyridine (DHP) Ca²⁺ channel antagonist, on dog coronary and saphenous arterial vascular muscle cells using the whole-cell patch-clamp method. Long-lasting (L-type) inward currents in 20 mM Ba²⁺ were measured over a range of test potentials (300 ms) from –50 mV to + 90 mV from a holding potential of –80 mV in the presence of 1 M Bay k8644 (a DHP Ca²⁺ agonist). Ro 40-5967 caused a concentration-dependent suppression of Ca²⁺ channel currents in muscle cells from both arteries, with greater potency on coronary than saphenous arterial cells. The concentration of Ro 40-5967 which inhibited the magnitude of peak inward currents by 50% (IC₅₀) was estimated to be 1 M (n = 5) in muscle cells from coronary artery and 10 M (n = 4) in saphenous artery. Ro 40-5967 (1 M) decreased the amplitude of the activation current-voltage relationship for coronary L-type Ca²⁺ channel currents over a wider range of membrane potentials than verapamil, diltiazem, or nifedipine. In contrast, block of Ca²⁺ channel currents in saphenous artery cells by 1 M Ro 40-5967 was only observed at command potentials positive to 0 mV. Ro 40-5967 (1 M) significantly shifted the voltage-inactivation curve downward by 40% in coronary (n = 4), but only by 18% in saphenous arterial muscle cells (n = 3). The non-parallel shift of the coronary artery inactivation curve suggests that pronounced resting channel block is a notable feature of Ro 40-5967. The marked inhibition of Ba²⁺ current by 1 M Ro 40-5967 in the inactivation protocol in coronary arterial muscle cells was found over the entire range of membrane holding potentials tested, while inhibition in the saphenous artery inactivation curve occurred only from holding potentials more positive than –40 mV. Therefore, Ro 40-5967 is unique: 1) in acting over a wider range of voltages, on both instantaneous and resting Ca²⁺ currents, than other Ca²⁺ antagonists; 2) in producing more significant resting state block; and 3) in acting with selectivity for coronary over saphenous arteries.This research was supported by National Institutes of Health grants HL38537, HL38645, and by F. Hoffmann-La Roche, Basel, Switzerland     

Erworbene Bauchhöhlenmuskelstörungen

Zusammenfassung Die Bauchhöhle hat ein Faszienskelett, das durch ihren permanenten veränderhchen Ruhetonus verspannt gehalten wird. Zur Bauchhöhle gehören mit der seitlichen Bauchmuskulatur auch das Zwerchfell und der Beckenboden. Willkürliche und reflektorische Tonusänderungen bedingen ihre Verformung und ihren Verschluß oder ihre Eröffnung. Am Versuchstier haben wir diesen Ruhetonus schon in der Schwanzmuskulatur nachgewiesen, von der der Beckenboden des Menschen stammesgeschichtlich abstammt. Der Beckenboden bildet mit den Sphinkteren das anorektale Kontinenzorgan. Es ist, phylogenetisch erklärbar, bei der Frau viel schwächer entwickelt als beim Mann. Diese unterschiedliche Mächtigkeit ist his zu den Kernen des Rückenmarks, die diese Muskulatur steuern, zu verfolgen. Diese Asthenie des weiblichen Kontinenzorgans wird durch das Gebären und die Obstipation noch zusätzlich belastet. Das gleiche gilt für die Bauchdecke der Frau, die, wie hier nachgewiesen wird, nach einer Gravidität die gleichen, bleibenden Denervationserscheinungen ihrer Muskulatur erkennen läß t. Es sind die gleichen Schäden, die der Beckenboden mit den Sphinkteren erleidet. In schwereren Fällen ist neben der Inkontinenz also auch ein Schlotterbauch die Folge dieser Belastungen. Der ruhetonisierte Beckenboden kann das spastische Beckenbodensyndrom, die kontinente Obstipation, zur Folge haben. Sic kann psychotherapeutisch geheilt werden. Davon muß die inkontinente Obstipation unterschieden werden, die manchmal mit einem Mastdarmvorfall einhergeht. Bei ihr liegt das Hindernis im Darm. Sic kann in schweren Fällen durch eine Sigmaresektion gebessert werden. Die Denervationsinkontinenz ist am besten durch das operative Engerstellen des ganzen Levatortrichters zu bessern. Voraussetzung ist: Der gelähmte Beckenboden muß noch eine Restruheaktivität aufweisen.

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Acquired disturbances of muscles of the peritoneal cavity

The peritoneal cavity has a fascial skeleton that is kept under tension by permanent variable resting tone maintained by the abdominal muscles. The lateral abdominal muscles, the diaphragm and the pelvic floor are all components of this fasciomuscular support system. Voluntary and reflective changes in muscle tension allow the entry and exit of matter into and out of the spherical abdominal cavity by opening and closing of specialized wall segments called sphincters. We have previously demonstrated the existence of a resting tone in the tail muscles of mammals from which the human pelvic floor muscles are derived. The pelvic floor and its integrated sphincters form the anorectal organ of continence. This organ is much weaker in females than in males. The spinal centers that govern continence, contain in the female significantly fewer ganglion cells than the corresponding centers in the male. Childbirth and a commonly found tendency to develop constipation are additional stressors for the congenitally weaker female organ of continence. We explain in this paper why the abdominal wall and the pelvic floor may suffer stretch-induced denervation injuries during pregnancy and delivery. Such damage may persist in later life and can give rise to incontinence and flabby abdomen. Based on our work in this field, we found a new differentiation between continent and incontinent constipation. Continent constipation is caused by spasticity of the pelvic floor characterized by abnormally high sphincter activity. This spastic pelvic floor syndrome can be treated successfully by psychotherapeutic techniques. Incontinent constipation, in contrast, is always associated with subnormal activity of the sphincters and may be a cause of rectal prolapse. It can be treated successfully by anterior rectosigmoid resection. Incontinent constipation will also require operative approximation of the levators in many cases. Improvement cannot be expected to result from this procedure, however, unless the pelvic floor shows some residual resting activity.

Korrespondenz an: em. Prof. Dr. Dr. h. c. mult. F. Stelzner