Portable multi-purpose device for monitoring of physiological informations

Unconstrained system that measures physiological information as skin temperatures and heart rate per unit time of a human subject was developed. The system contained portable device included memory control unit, instrumentation unit, timer and batteries, read-out unit, test unit and verify unit. Total number of data and channels, and interval were selected by switches in the memory control unit. The data from the instrumentation unit were transferred to memory control unit and stored in the Erasable Programmable ROM (EPROM). After measurement, EPROM chip was taken off the memory control unit and put on the read-out unit which transferred the data to the microcomputer. The data were directly calculated and analyzed by microcomputer. In application of the instrumentation unit, 8-channel skin thermometer was developed and tested. After amplification, 8 analog signals were multiplexed and converted into the binary codes. The digital signals were sequentially transferred to memory control unit and stored in the EPROM under controlled signal. The accuracy of the system is determined primarily by the accuracy of the sensor of instrumentation unit. The overall accuracy of 8-channel skin thermometer is conservatively stated within 0.1 degree C. This may prove to be useful in providing an objective measurement of human subjects, and can be used in studying environmental effect for human body and sport activities in a large population setting.     

Limitations of the surface electromyography technique for estimating motor unit synchronization

Motor unit synchronization was estimated from the surface electromyograms (EMG) of the first dorsal interosseus muscle of human volunteers by a simplified surface-EMG technique (Milner-Brown et al. 1973, 1975). Single motor units were identified from intramuscular recordings and were used to obtain a spike-triggered average of the surface-EMG. The discharge rate of a reference motor unit was controlled at two levels (high and low), and the effect of motor unit activity on the surface-EMG estimate of synchronization was studied in 56 motor units. The surface-EMG estimate of motor unit synchronization was significantly higher when the reference motor unit discharged at the high rate than when it discharged at the low rate. A regression analysis indicated that the synchronization ratio calculated from the surface EMG was significantly correlated with the level of EMG activity in the muscle. Motor unit synchronization was also estimated from surface-EMG measurements that were derived by computer simulation. The simulation permitted manipulation of motor unit activity (discharge rate and recruitment) with a complete absence of synchrony among the units in the pool. The stimulated surface-EMG index was influenced by an artifact associated with signal rectification, and this effect changed non-monotonically with motor unit activity. Furthermore, the increase in the motor unit activity reduced the signal-to-noise ratio of the spike-triggered surface EMG average, and consequently decreased the sensitivity of the surface-EMG index as an estimate of motor unit synchronization. We conclude that the simplified surface-EMG method (Milner-Brown et al. 1973, 1975) does not provide a useful index of motor unit synchronization due to its inability to accurately distinguish the synchronization from methodological effects related to a rectification artifact and variation in the signal-to-noise ratio.     

Preparation of chondroitin sulfate libraries containing disulfated disaccharide units and inhibition of thrombin by these chondroitin sulfates

Chondroitin sulfate (CS) containing GlcA-GalNAc(4,6-SO₄) (E unit) and CS containing GlcA(2SO₄)-GalNAc(6SO₄) (D unit) have been implicated in various physiological functions. However, it has been poorly understood how the structure and contents of disulfated disaccharide units in CS contribute to these functions. We prepared CS libraries containing E unit or D unit in various proportions by in vitro enzymatic reactions using recombinant GalNAc 4-sulfate 6-O-sulfotransferase and uronosyl 2-O-sulfotransferase, and examined their inhibitory activity toward thrombin. The in vitro sulfated CSs containing disulfated disaccharide units showed concentration-dependent direct inhibition of thrombin when the proportion of E unit or D unit in the CSs was above 15–17%. The CSs containing both E unit and D unit exhibited higher inhibitory activity toward thrombin than the CSs containing either E unit or D unit alone, if the proportion of the total disulfated disaccharide units of these CSs was comparable. The thrombin-catalyzed degradation of fibrinogen, a physiological substrate for thrombin, was also inhibited by the CS containing both E unit and D unit. These observations indicate that the enzymatically prepared CS libraries containing various amounts of disulfated disaccharide units appear to be useful for elucidating the physiological function of disulfated disaccharide units in CS.     

Molecular diversity of the 5S rRNA gene and genomic relationships in the genus Avena (Poaceae: Aveneae).

The molecular diversity of the rDNA sequences (5S rDNA units) in 71 accessions from 26 taxa of Avena was evaluated. The analyses, based on 553 sequenced clones, indicated that there were 6 unit classes, named according to the haplomes (genomes) they putatively represent, namely the long A1, long B1, long M1, short C1, short D1, and short M1 unit classes. The long and short M1 unit classes were found in the tetraploid A. macrostachya, the only perennial species. The long M1 unit class was closely related to the short C1 unit class, while the short M1 unit class was closely related to the long A1 and long B1 unit classes. However, the short D1 unit class was more divergent from the other unit classes. There was only one unit class per haplome in Avena, whereas haplomes in the Triticeae often have two. Most of the sequences captured belonged to the long A1 unit class. Sequences identified as the long B1 unit class were found in the tetraploids A. abyssinica and A. vaviloviana and the diploids A. atlantica and A. longiglumis. The short C1 unit class was found in the diploid species carrying the C genome, i.e., A. clauda, A. eriantha, and A. ventricosa, and also in the diploid A. longiglumis, the tetraploids A. insularis and A. maroccana, and all the hexaploid species. The short D1 unit class was found in all the hexaploid species and two clones of A. clauda. It is noteworthy that in previous studies the B genome was found only in tetraploid species and the D genome only in hexaploid species. Unexpectedly, we found that various diploid Avena species contained the B1 and D1 units. The long B1 unit class was found in 3 accessions of the diploid A. atlantica (CN25849, CN25864, and CN25887) collected in Morocco and in 2 accessions of A. longiglumis (CIav9087 and CIav9089) collected in Algeria and Libya, respectively, whereas only 1 clone of A. clauda (CN21378) had the short D1 unit. Thus there might be a clue as to where to search for diploids carrying the B and D genomes. Avena longiglumis was found to be the most diverse species, possibly harboring the A, B, and C haplomes. The long M1 and short M1 are the unit classes typical of A. macrostachya. These results could explain the roles of A. clauda, A. longiglumis, and A. atlantica in the evolution of the genus Avena. Furthermore, one clone of the tetraploid A. murphyi was found to have sequences belonging to the short D1 unit class, which could indicate that A. murphyi might have been the progenitor of hexaploid oats and not, as postulated earlier, A. insularis. The evolution of Avena did not follow the molecular clock. The path inferred is that the C genome is more ancient than the A and B genomes and closer to the genome of A. macrostachya, the only existing perennial, which is presumed to be the most ancestral species in the genus.     

Oxidative capacity and capillary density of diaphragm motor units

Motor units in the cat diaphragm (DIA) were isolated in situ by microdissection and stimulation of C5 ventral root filaments. Motor units were classified based on their isometric contractile force responses and fatigue indexes (FI). The muscle fibers belonging to individual units (i.e., the muscle unit) were identified using the glycogen-depletion method. Fibers were classified as type I or II based on histochemical staining for myofibrillar adenosine triphosphatase (ATPase) after alkaline preincubation. The rate of succinate dehydrogenase (SDH) activity of each fiber was determined using a microphotometric procedure. The location of capillaries was determined from muscle cross sections stained for ATPase after acid (pH = 4.2) preincubation. The capillarity of muscle unit fibers was determined by counting the number of capillaries surrounding fibers and by calculating the number of capillaries per fiber area. A significant correlation was found between the fatigue resistance of DIA units and the mean SDH activity of muscle unit fibers. A significant correlation was also observed between DIA unit fatigue resistance and both indexes of muscle unit fiber capillarity. The mean SDH activity and mean capillary density of muscle unit fibers were also correlated. We conclude that DIA motor unit fatigue resistance depends, at least in part, on the oxidative capacity and capillary density of muscle unit fibers.     

Small and large fixed ratios with the same unit price

Key pressing of rats was maintained under multiple and discrete-trial choice schedules with reinforcer units of 45 mg food pellets or 3.5 s dips of sucrose solution. Both smaller and larger fixed ratio (FR) schedules were associated with the same unit price in a manner, for example, that each of eight iterations of FR120 was associated with delivery of a single reinforcer unit and one instance of FR960 was associated with eight reinforcer units. FR requirement varied between 20 and 1560 per aggregate reinforcer and unit price varied between 20 and 240 per reinforcer unit. During multiple schedules with food reinforcers, rates and patterns of responding were comparable over nearly a 50-fold range of FR requirements (20-1380) when unit price was 20; over nearly a six-fold range of FR requirements (120-720) when unit price was 120; and was only marginally maintained when unit price was 240. Demand for food pellets was comparatively inelastic at FRs between 20 and 120, during which subjects did not receive supplemental feeding outside experimental sessions, but was elastic at FRs greater than 240, when subjects sometimes did receive supplemental feeding. In a discrete-trial choice procedure with a constant unit price of 120 for sucrose solution, subjects were indifferent between smaller FRs and alternative FRs as large as 480, but began switching away from larger FRs that were 600 or greater. Because responding had been comparably maintained under both FR120 and FRs as large as 960 in the multiple schedule, results from the choice procedure indicated that choice performance was influenced by variables other than FR requirement and unit price. Because aggregate reinforcers were the same for smaller and larger FRs, the most likely reason for preferring smaller FRs was the nearness in time to some reinforcer.     

Collaborative systematic review of the randomised trials of organised inpatient (stroke unit) care after stroke. Stroke Unit Trialists' Collaboration.

OBJECTIVES: To define the characteristics and determine the effectiveness of organised inpatient (stroke unit) care compared with conventional care in reducing death, dependency, and the requirement for long term institutional care after stroke. DESIGN: Systematic review of all randomised trials which compared organised inpatient stroke care with the contemporary conventional care. Specialist stroke unit interventions were defined as either a ward or team exclusively managing stroke (dedicated stroke unit) or a ward or team specialising in the management of disabling illnesses, which include stroke (mixed assessment/rehabilitation unit). Conventional care was usually provided in a general medical ward. SETTING: 19 trials (of which three had two treatment arms). 12 trials randomised a total of 2060 patients to a dedicated stroke unit or a general medical ward, six trials (647 patients) compared a mixed assessment/rehabilitation unit with a general medical ward, and four trials (542 patients) compared a dedicated stroke unit with a mixed assessment/rehabilitation unit. MAIN OUTCOME MEASURES: Death, institutionalisation, and dependency. RESULTS: Organised inpatient (stroke unit) care, when compared with conventional care, was best characterised by coordinated multidisciplinary rehabilitation, programmes of education and training in stroke, and specialisation of medical and nursing staff. The stroke unit care was usually housed in a geographically discrete ward. Stroke unit care was associated with a long term (median one year follow up) reduction of death (odds ratio 0.83, 95% confidence interval 0.69 to 0.98; P < 0.05) and of the combined poor outcomes of death or dependency (0.69, 0.59 to 0.82; P < 0.0001) and death or institutionalisation (0.75, 0.65 to 0.87; P < 0.0001). Beneficial effects were independent of patients'' age, sex, or stroke severity and of variations in stroke unit organisation. Length of stay in a hospital or institution was reduced by 8% (95% confidence interval 3% to 13%) compared with conventional care but there was considerable heterogeneity of results. CONCLUSIONS: Organised stroke unit care resulted in long term reductions in death, dependency, and the need for institutional care. The observed benefits were not restricted to any particular subgroup of patients or model of stroke unit care. No systematic increase in the use of resources (in terms of length of stay) was apparent.     

Activation and stabilization of the catalytic unit of adenylate cyclase.

The requirements for stability and activity of the catalytic unit (C) of adenylate cyclase were investigated. After solubilization of bovine brain membranes in the zwitterionic detergent 3-[(3-cholamidopropyl)dimethylammonio]propane-1-sulphonate (Chaps), the catalytic unit was separated from the stimulatory guanine-nucleotide-binding protein (Gs) by gel filtration on Ultrogel AcA-34. The partially purified C unit was rapidly inactivated at 30 degrees C; 0.25 mM-ATP stabilized activity. Although C-unit activity was dependent on Mg2+ or Mn2+, stabilization by ATP did not require bivalent cations. Activity of the Ultrogel-AcA-34-purified C unit was increased by Ca2+ plus calmodulin and by phosphatidylcholine plus lysophosphatidylcholine; activity in the presence of both activators was significantly greater than with each alone. Calmodulin plus Ca2+ and phospholipids also stabilized C unit. The column-purified C unit was activated by forskolin; the effect of forskolin was additive to those of calmodulin plus Ca2+ and phospholipids. p[NH]ppG-stimulated adenylate cyclase activity was reconstituted by mixing samples from the gel-filtration column containing Gs with C unit. Activation by Ca2+ plus calmodulin and Gs plus p[NH]ppG was additive; Ca2+ plus calmodulin did not alter the concentration of p[NH]ppG required for half-maximal activation. Results were similar with forskolin and Gs plus p[NH]ppG; the presence of one activator did not alter the effect of the other. These studies define conditions for separation of C unit and Gs from brain adenylate cyclase and demonstrate that ATP (in the absence of bivalent cations), phospholipids, calmodulin plus Ca2+, and forskolin all interact with C unit in a manner that is independent of functional Gs.     

中华大蟾蜍染色体“单位线”结构的研究

适量BrdU处理中华大蟾蜍外周血淋巴细胞,常规制片后可观察到直径恒定为0.4μm的染色质纤维——单位线结构。本实验表明两栖类染色体同样具有单位线结构,并发现组成染色体两单体的姐妹单位线相伴排列,且与中期染色体有明显的形态联系。通过分析显示染色体和单位线过渡变化的分裂相,认为染色体高级结构由单位线进一步螺旋化完成,从而支持Bak模型。     

Estimation of human fetal-placental unit metabolic rate by application of the Bohr principle

The Bohr Principle via continuous indirect calorimetry was used to estimate human fetal-placental unit metabolic rate in 12 normal women undergoing elective caesarean section under continuous lumbar epidural anaesthesia. Maternal oxygen consumption decreased after umbilical cord clamping and after placental removal. Fetal-placental unit oxygen consumption was 10.7 +/- 1.3 ml/min per kg (mean +/- SEM). Fetal oxygen consumption was 6.8 +/- 1.4 ml/min per kg. Placental oxygen consumption was 37 +/- 12 ml/min per kg. Fetal-placental unit carbon dioxide production was 9.2 +/- 1.2 ml/min per kg. These mean values agree favourably with measurements of uterine and fetal metabolism from other mammalian species. Maternal minute ventilation decreased with removal of the fetal-placental unit, and this decrease was found to be linearly related to the fetal-placental unit carbon dioxide production.     

Characterization of summer infertility of sows in large confinement units

Data were from 3119 farrowings in three large swine confinement units in eastern North Carolina. Litters were weaned during April through October. Interval to first estrus after weaning was greater during June through September than during other months. The two-way interactions among farm unit, parity and month weaned all affected weaning-to-estrus interval. Conception rate at first estrus was lower for primiparous than for multiparous sows and declined from April through July. Conception rate at first estrus was affected by farm by parity interaction. Weaning-to-conception interval was longer for primiparous than multiparous sows and was longer during June through October. Weaning-to-conception interval was affected by interactions of unit with parity and unit with month weaned. Total pigs farrowed at the subsequent farrowing was affected by unit, parity, length of the previous lactation and the unit x parity interaction. Overall, reproductive performance varied among farm units, was lower in primiparous than in multiparous sows and was reduced during June through October.     

Function of Node Unit in Photosynthate Distribution to Root in Higher Plants

Leaf-root interaction is a critical factor for plant growth during maturation and activity of roots is maintained by a sufficient supply of photosynthates. To explain photosynthate distribution among organs in field crops, the node unit hypothesis is proposed. One node unit consists of a leaf and an upper adventitous root, as well as the axillary organs and the lower adventitious root, which is adjacent to one node. Using ¹⁴C as tracer, the carbon distribution system has been clarified using spring wheat, soybean, tomato, and potato. The interrelationship among organs from the strongest to the weakest is in the following order: (1) within the node unit > (2) between the node unit in the same or adjacent phyllotaxy > (3) in the main root or apical organs, which are adjacent to the node unit. Within the node unit, ¹⁴C assimilated in the leaf on the main stem tended to distribute to axillary organs in the same node unit. The ¹⁴C assimilated in the leaf of axillary organs tended to distribute within the axillary organs, including adventitious roots in the axillary organ and then translocated to the leaf on the main leaf of the same node unit. In different organs of the node unit in the same or adjacent phyllotaxy, ¹⁴C assimilated in the leaf on the main stem was also distributed to the organs (node unit) belonging to the same phyllotaxy in dicotyledons, while in monocotyledons, the effect of phyllotaxy on ¹⁴C distribution was not clear. Among roots/apical organs and node unit, ¹⁴C assimilated in the upper node unit was distributed to apical organs and ¹⁴C assimilated in the lower node unit was distributed to roots. Thus the node unit hypothesis of photosynthate distribution among organs is very important for understanding the high productivity of field crops.     

Amplitude cancellation reduces the size of motor unit potentials averaged from the surface EMG.

The purpose of the study was to evaluate the influence of selected physiological parameters on amplitude cancellation in the simulated surface electromyogram (EMG) and the consequences for spike-triggered averages of motor unit potentials derived from the interference and rectified EMG signals. The surface EMG was simulated from prescribed recruitment and rate coding characteristics of a motor unit population. The potentials of the motor units were detected on the skin over a hand muscle with a bipolar electrode configuration. Averages derived from the EMG signal were generated using the discharge times for each of the 24 motor units with lowest recruitment thresholds from a population of 120 across three conditions: 1) excitation level; 2) motor unit conduction velocity; and 3) motor unit synchronization. The area of the surface-detected potential was compared with potentials averaged from the interference, rectified, and no-cancellation EMGs. The no-cancellation EMG comprised motor unit potentials that were rectified before they were summed, thereby preventing cancellation between the opposite phases of the potentials. The percent decrease in area of potentials extracted from the rectified EMG was linearly related to the amount of amplitude cancellation in the interference EMG signal, with the amount of cancellation influenced by variation in excitation level and motor unit conduction velocity. Motor unit synchronization increased potentials derived from both the rectified and interference EMG signals, although cancellation limited the increase in area for both potentials. These findings document the influence of amplitude cancellation on motor unit potentials averaged from the surface EMG and the consequences for using the procedure to characterize motor unit properties.     

The effect of activity during early postnatal development on motor unit size

At early stages of neuromuscular development, motor unit territory is expanded, with each muscle fibre being supplied by several axons. During postnatal development, some synapses are eliminated, motor unit size decreases, and the adult distribution of motor unit sizes emerges. This process depends on activity, since it proceeds more rapidly when the nerve is activated and is slower when activity is reduced. Here we studied whether, in addition to influencing the rate of retraction of motor unit territory, activity during the critical period of development affects the final outcome of the distribution of motor unit sizes. The sciatic nerve of 8- to 12-day-old rats was stimulated daily. One week later the tension of the extensor digitorum longus muscle and that of its individual motor units was recorded. The sizes of individual motor units were calculated and compared with those from animals that received no stimulation. The distribution of motor unit sizes from stimulated muscles was not significantly different from those from control muscles. Therefore, we conclude that although activity increases the rate at which motor units attain their adult size, it does not influence the final outcome of motor unit size distribution.     

Dependence of photosynthetic rates on leaf density thickness in deciduous woody plants grown in sun and shade

Comparisons of photosynthetic rates were made on leaves of ten species of woody dicotyledons grown in the field under full sun or under a canopy which transmitted approximately 18% of full light. Photosynthesis and dark respiration were measured and compared on various bases: area, chlorophyll, fresh weight of lamina, density thickness (fresh weight per unit area), and protein.

Light-saturated photosynthesis per unit area or unit chlorophyll was about 1.5 times greater in the sun leaves than in the shade leaves and essentially equal per unit fresh weight or unit protein. Sun leaves were thicker but the enzymes per unit fresh weight remained constant as thickness varied. Chlorophyll per unit area remained about constant; chlorophyll per unit fresh weight varied inversely with changes in leaf thickness. Thus, density thickness variation is important in photosynthetic adaptation to sun and shade. This is also shown by the relationship between light-saturated photosynthesis per unit area and density thickness.

     

Axis differentiation in two South American Nothofagus species (Nothofagaceae)

An analysis was carried out on the length, diameter and number of leaves, and the ratios between these variables for current-year growth units (sibling growth units) derived from different nodes of previous-year growth units (parent growth units) of young Nothofagus dombeyi and Nothofagus pumilio trees. Changes in sibling growth unit length, diameter, and number of leaves with position on the parent growth unit were assessed. In both species, sibling-growth unit morphology varied according to both the axis type of the parent growth unit and the position of the sibling growth unit on its parent growth unit. For the largest parent growth units, the length, diameter and number of leaves of their sibling growth units decreased from distal to proximal positions on the parent growth unit. Distal sibling growth units had a more slender stem and longer internodes than proximal sibling growth units. Sibling growth units in equivalent positions tended to have a more slender stem for N. dombeyi than for N. pumilio. Long main-branch growth units of N. pumilio had longer internodes than those of N. dombeyi; the converse was true for shorter growth units. The growth unit diameter/leaf number ratio was consistently higher for N. pumilio than for N. dombeyi. Nothofagus pumilio axes would go through a faster transition from an 'exploring' morphology to an 'exploiting' morphology than N. dombeyi axes. Within- and between-species variations in growth unit morphology should be considered when assessing the adaptive value of the branching pattern of plants.     

Analysing branching pattern in plantations of young red oak trees (Quercus rubra L., Fagaceae)

Branching patterns of the growth units of monocyclic or bicyclic annual shoots on the main axis of 5-year-old red oaks were studied in a plantation in south-western France. For each growth unit, the production of axillary structures associated with each node was described in the form of a sequence. For a given category of growth units, homogeneous zones (i.e. zones in which composition in terms of type of axillary production does not change substantially) were identified on such sequences using a dedicated statistical model called a hidden semi-Markov chain. For instance, on the first growth unit of bicyclic annual shoots, a zone with 1-year-delayed branches was found systematically below a zone with buds and one-cycle-delayed branches. Branching patterns shown by the growth unit of monocyclic annual shoots and on the second growth unit of bicyclic annual shoots were very similar. Branches with a 1-year delay in development tended to be polycyclic at the top of the growth unit and monocyclic lower down. The number of nodes shown by the branched zone of the growth unit of monocyclic annual shoots was stable, irrespective of the total number of nodes of the growth unit. In contrast, the second growth unit of bicyclic annual shoots exhibited a correlation between the number of nodes in the branching zone and the total number of nodes. The contribution made by this method to understanding plant functioning is discussed.     

Total family unit Helicobacter pylori eradication and pediatric re-infection rates

BACKGROUND: Re-infection with Helicobacter pylori is more common in children than adults, and it is generally accepted that the family unit plays a significant role in primary childhood infection. We investigated whether the family unit plays a significant role in pediatric re-infection and if eradication of H. pylori from the entire family reduces the risk of childhood re-infection. METHODS: Fifty families, each with an H. pylori-infected pediatric index case (mean age 9.48 years), were recruited. A 13carbon urea breath test was performed on all family members in the same house as the index case. Each family unit was randomized into a 'family unit treatment' group (all infected family members treated) or an 'index case treatment' group (index case only treated). RESULTS: At long-term follow-up (mean 62.2 months), there were three re-infected children in the 'index case treatment' group compared with one in the 'family unit treatment' group. The re-infection rate was 2.4% per patient per year in the 'index case treatment' group and 0.7% per patient per year in the 'family unit treatment' group (p = .31). CONCLUSIONS: This study is the first to evaluate the effect of total family unit H. pylori eradication on pediatric re-infection rates and reports the longest period of re-infection follow-up in children. In childhood, re-infection with H. pylori is not significantly reduced by family unit H. pylori eradication.