Effect of ambient temperature on heat production and heat loss in burn patients.

Four controls and eight burned patients with thermal injury ranging from 7 to 84% total body surface were studied in an environmental chamber at 25 and 33 degrees C ambient temperature and a constant vapor pressure during two consecutive 24-h periods. Hypermetabolism was present in the burn patients in both ambient temperatures and core and skin temperatures were consistently higher than in the normal men despite increased evaporative water loss. The higher environmental temperature decreased metabolic rate in patients with large thermal injuries in whom the decrement in dry heat loss produced by higher ambient temperature exceeded the increase of wet heat loss. In patients with burns smaller than 60%, these changes equaled one another and higher environmental temperature exerted no effect on metabolic rate. Core-skin heat conductivity increased with burn size; patients with large burns were characterized by inadequate core-skin insulation when exposed to the cooler environment, necessitating the compensatory increase of metabolic rate. This increase, however, was small and of the order of 5-8 kcal times m-2 times h-1.     

The modelling of a Pseudomonas aeruginosa wound process

P. aeruginosa wound infection was induced in white mice to test new preparations against P. aeruginosa. This model ensures the nearest approximation to the course of P. aeruginosa chronic infection, i.e. it reproduces the focus of inflammation and the prolonged course of the disease (the positive decision on application No. 4, 324, 555 of November 2, 1987, has been obtained). The essence of the method consists in obtaining the model of P. aeruginosa wound infection by a combined trauma of the skin (burn and incision): P. aeruginosa is introduced in a dose of 6 X 10(9)-8 X 10(9) microbial cells into the burn blister through the incision made 3 hours after the burn and then 20-24 hours later in a dose of 10(9)-2 X 10(9) microbial cells, introduced under the crust formed by that time.     

Opsonic Activity of Sera and Blister Fluid from Severely Burned Patients Evaluated by a Chemiluminescence Method

Burn wound sepsis is the most common and severe complication in the patients with severe burn. To know the systemic and local defect in immunity of burned patients, we measured the luminol-enhanced chemiluminescence (CL) response of normal polymorphonuclear leukocytes (PMNs) upon exposure to zymosan particles, bacteria or Candida albicans that were opsonized with any of patient's serum, blister fluid of burn wound or pooled normal serum (blood type AB). Sera from patients exhibited lower opsonic activities than those of pooled normal serum in the early postburn days. The levels of serum immunoglobulins, complement components and plasma fibronectin were found to correlate well with opsonin-index (OI), which was determined based on the CL response data obtained during the course of infusion therapy with fresh frozen plasma. Furthermore, patient's blister fluid showed much lower opsonic activity against bacteria such as Pseudomonas aeruginosa than patient's own serum. These results indicate that blister fluid is also not effective to opsonize bacteria because of the marked depression of the levels of immunoglobulins and complement components. Destruction of the skin barrier by thermal injury and impairment of systemic or local humoral immunity may predispose these patients to burn wound sepsis.     

The biochemistry of blister fluid from pediatric burn injuries: proteomics and metabolomics aspects

Burn injury is a prevalent and traumatic event for pediatric patients. At present, the diagnosis of burn injury severity is subjective and lacks a clinically relevant quantitative measure. This is due in part to a lack of knowledge surrounding the biochemistry of burn injuries and that of blister fluid. A more complete understanding of the blister fluid biochemistry may open new avenues for diagnostic and prognostic development. Burn insult induces a highly complex network of signaling processes and numerous changes within various biochemical systems, which can ultimately be examined using proteome and metabolome measurements. This review reports on the current understanding of burn wound biochemistry and outlines a technical approach for ‘omics’ profiling of blister fluid from burn wounds of differing severity.     

The germination of mucilaginous seeds of t Plantago coronopus,Reboudia pinnata,and t Carrichtera annua on cyanobacterial soil crust from the Negev Desert

We studied the effect of intact, crushed or sterile cyanobacterial soil crust from the Negev Desert highlands of Israel as substrates for the germination of seeds of three annual plant species from local populations that produce mucilaginous seeds t Plantago coronopus, Reboudia pinnata and t Carrichtera annua. Mucilaginous seeds of these species were wetted on local intact cyanobacterial soil crust which inhibited their germination in comparison with their germination on filter paper. However, the percentage of germination of each species differed on sterile and crushed soil crust after 72 h of wetting. Germination of t Plantago coronopus seeds was inhibited mechanically and biologically on intact soil crust, since it was significantly higher on both crushed and sterile soil crust. Germination of t Reboudia pinnata seeds was slightly mechanically and biologically inhibited on intact soil crust, but germination on live crushed crust was higher than on sterile crushed crust. By contrast, germination of t Carrichtera annua seeds was not mechanically inhibited by live soil crust but there was significant biological acceleration of germination on intact soil crust relative to crushed soil crust. Each of the three species exhibited different requirements for germination. Germination of t P. coronopus is promoted by disturbances and removing the crust components (including its biological and structural effects). t R. pinnata and t C. annua germination is less affected by crust disturbance but is generally inhibited after removing the live components of the cyanobacterial crust.These species differences suggest different functions of the mucilage of the seed coat for the three species.     

Interleukin-1 levels in blister fluids of some skin diseases with blister formation

The interleukin-1 (IL-1) concentrations in 32 blister fluid samples from 26 patients with several bullous dermatoses were determined using a radioimmunoassay technique in order to investigate the relation between IL-1 levels and blister formation. In epidermolysis bullosa, cases with the recessive dystrophic type showed normal levels, but about half of the cases of the simplex type demonstrated high levels. In autoimmune bullous diseases a tendency to higher levels was observed, and especially a patient with herpes gestationis had remarkably high levels. The high IL-1 levels in 25% (3/12) of samples from burn patients are probably related to the severity of inflammation and the duration after bulla formation. Since the IL-1 levels showed no great change in time courses of days, observations in the shorter term, i.e. in the course of hours, will be more useful.     

Proliferative activity of endotheliocytes of growing corneal capillaries in the rabbit

The intensity of capillaries growth in the rabbit's cornea was investigated after chemical burn and exposure to colchicine. Proliferative activity was determined in endothelial cells along the course of newly formed capillaries. Growth intensity proved to be 2 times higher when burn and colchicine effects were combined, than in case of burn alone. The increase in the proliferative activity of endothelial cells and the peculiarities of their arrangement were found in both cases. The most active proliferation was observed in cells located in a zone where capillaries originated from intact vessels of the limb. The process of new vessel formation depends on endotheliocyte shift from this zone towards the site where growth-stimulating factors were applied.     

Influence of stress rate on water loss, matrix deformation and chondrocyte viability in impacted articular cartilage

The biomechanical response of articular cartilage to a wide range of impact loading rates was investigated for stress magnitudes that exist during joint trauma. Viable, intact bovine cartilage explants were impacted in confined compression with stress rates of 25, 50, 130 and 1000 MPa/s and stress magnitudes of 10, 20, 30 and 40 MPa. Water loss, cell viability, dynamic impact modulus (DIM) and matrix deformation were measured. Under all loading conditions the water loss was small (approximately 15%); water loss increased linearly with increasing peak stress and decreased exponentially with increasing stress rate. Cell death was localized within the superficial zone (< or =12% of total tissue thickness); the depth of cell death from the articular surface increased with peak stress and decreased with increasing stress rate. The DIM increased (200-700 MPa) and matrix deformation decreased with increasing stress rate. Initial water and proteoglycan (PG) content had a weak, yet significant influence on water loss, cell death and DIM. However, the significance of the inhomogeneous structure and composition of the cartilage matrix was accentuated when explants impacted on the deep zone had less water loss and matrix deformation, higher DIM, and no cell death compared to explants impacted on the articular surface. The mechano-biological response of articular cartilage depended on magnitude and rate of impact loading.     

DEVELOPMENT,STRUCTURE AND FUNCTION OF SUBPALISADE CELLS IN WATER IMPERMEABLE SIDA SPINOSA SEEDS

Newly matured prickly sida (Sida spinosa) seeds were hard, but afterripening, heat or pressure permitted water entry solely via a predefined region of the chalazal area. In this region, the raising of a “blister” formed by separation of the palisade of the seed coat from underlying tissues preceeded measurable water uptake by prickly sida seeds. A single subpalisade layer, unique to the region beneath the blister, was involved in the sequence of events in seed water uptake. The lateral walls of subpalisade cells invariably broke near the palisade border and cell contents were extruded onto the surface. This report describes the cytological development of the subpalisade layer from 1-21 days post anthesis. Cells beneath the potential “blister” near the chalazal slit developed into columnar subpalisades and cells beneath the subpalisades or beyond the margins of the potential blister, developed into oval, thick-walled chalazal cap cells. By 6-10 days, distinct features of the subpalisades included: 1) thin portions in lateral walls due to lack of secondary wall depositions at the palisade border; 2) progressive accumulation of fibrous material in numerous vacuoles; and 3) progressive coalescence of osmiophilic bodies and degeneration of cytoplasmic contents. At 21 days, the seeds were dehydrated, mature and hard, but the thin, lateral subpalisade walls were still intact and had not broken. The thin-walled portions were predetermined weak sites that break, permit palisade separation, expose the area under the blister to available moisture and result in subsequent imbibition of water by the seed. The hydrophilic, fibrous material extruded from the ruptured subpalisade cells may attract water to the newly exposed surface and facilitate penetration of water into the nutritive and embryonic seed tissues.     

Presence of interleukin 10 in the serum and blister fluid of patients with pemphigus vulgaris and pemphigoid

Interleukin 10 (IL-10) is an immunoregulatory cytokine produced by T lymphocytes and macrophages. Recently, it has been suggested that IL-10 may be involved in the pathogenesis of various inflammatory and autoimmune diseases. Using an ELISA we investigated the presence of IL-10 in the serum and blister fluid of pemphigus vulgaris (PV) patients with active disease and those in prolonged clinical remission compared with normal controls. Sera from patients with bullous pemphigoid (BP), ocular cicatricial pemphigoid (OCP), oral pemphigoid (OP) and blister fluid from five patients with BP were also studied. Increased levels of IL-10 were detected in the sera of 87.5% of patients with active PV and were statistically significant (P=0.0003) when compared with levels in normal human serum. Lower levels of IL-10 were detected in 12.5% PV patients in remission and were statistically significant (P=0.0001) when compared with levels in patients with active disease. Levels of IL-10 were detected in sera of 4.6% (1 of 24) of the normal controls. The levels of IL-10 were approximately four times higher in blister fluids than levels in the serum in the same PV patients. This difference was highly statistically significant (P=0.0008). A correlation was observed between serum levels of IL-10 and titres of pemphigus autoantibodies and with disease severity. Elevated level of IL-10 was detected in the blister fluid from five BP patients. Levels of IL-10 in the sera of patients with BP, OCP and OP were not significantly increased. These preliminary data suggest that IL-10 in concert with other cytokines may play an important role in the pathogenesis of PV and BP.     

温度和CO2浓度升高对荒漠藻结皮光合作用的影响

2007年,对腾格里沙漠东南缘沙坡头地区1956年(51龄)和1981年(26龄)人工植被区及自然植被区的藻结皮净光合速率(P_n)变化,及其与结皮含水量(>100%、40%～60%和<20%)、大气CO₂浓度(360和700 mg·L^-1)和温度(13 ℃、24 ℃ 和28 ℃)的关系进行研究.结果表明：51龄、26龄人工植被区和自然植被区的藻结皮P_n分别为3.4、4.4和3.2 μmol·m^-2·s^-1,且51龄人工植被区藻结皮的P_n显著高于26龄人工植被区和自然植被区;藻结皮含水量对其P_n影响显著,且中等含水量(40%～60%)藻结皮的P_n显著高于低含水量(<20%)和高含水量(>100%);CO₂倍增(700 mg·L^-1)后,中等和高含水量藻结皮的P_n增加了1.8～3.3倍,而低含水量时,藻结皮的P_n变化不明显;高含水量和中等含水量处理时,24 ℃和28 ℃条件下藻结皮的P_n较13 ℃时提高27%～66%,而在低含水量时,不同温度的藻结皮P_n值无显著差异.     

Biological Soil Crusts in a Xeric Florida Shrubland: Composition,Abundance, and Spatial Heterogeneity of Crusts with Different Disturbance Histories

Biological soil crusts consisting of algae, cyanobacteria, lichens, fungi, bacteria, and mosses are common in habitats where water and nutrients are limited and vascular plant cover is discontinuous. Crusts alter soil factors including water availability, nutrient content, and erosion susceptibility, and thus are likely to both directly and indirectly affect plants. To establish this link, we must first understand the crust landscape. We described the composition, abundance, and distribution of microalgae in crusts from a periodically burned, xeric Florida shrubland, with the goal of understanding the underlying variability they create for vascular plants, as well as the scale of that variability. This is the first comprehensive study of crusts in the southeastern United States, where the climate is mesic but sandy soils create xeric conditions. We found that crusts were both temporally and spatially heterogeneous in depth and species composition. For example, cyanobacteria and algae increased in abundance 10-15 years after fire and away from dominant shrubs. Chlorophyll a levels recovered rapidly from small-scale disturbance relative to intact crusts, but these disturbances added to crust patchiness. Plants less than 1 m apart can experience different crust environments that may alter plant fitness, plant interactions, and plant community composition.     

温度和CO2浓度升高对荒漠藻结皮光合作用的影响

2007年,对腾格里沙漠东南缘沙坡头地区1956年(51龄)和1981年(26龄)人工植被区及自然植被区的藻结皮净光合速率(P_n)变化,及其与结皮含水量(>100%、40%～60%和<20%)、大气CO₂浓度(360和700 mg·L^-1)和温度(13 ℃、24 ℃ 和28 ℃)的关系进行研究.结果表明：51龄、26龄人工植被区和自然植被区的藻结皮P_n分别为3.4、4.4和3.2 μmol·m^-2·s^-1,且51龄人工植被区藻结皮的P_n显著高于26龄人工植被区和自然植被区;藻结皮含水量对其P_n影响显著,且中等含水量(40%～60%)藻结皮的P_n显著高于低含水量(<20%)和高含水量(>100%);CO₂倍增(700 mg·L^-1)后,中等和高含水量藻结皮的P_n增加了1.8～3.3倍,而低含水量时,藻结皮的P_n变化不明显;高含水量和中等含水量处理时,24 ℃和28 ℃条件下藻结皮的P_n较13 ℃时提高27%～66%,而在低含水量时,不同温度的藻结皮P_n值无显著差异.     

黄土高原水蚀风蚀交错区藓结皮对土壤酶活性的影响

以黄土高原水蚀风蚀交错区黄绵土和风沙土上发育30年的典型藓结皮为对象,分6层采集0～12 cm土层土样,研究了藓结皮对不同土层4种水解酶活性的影响及其与土壤养分的关系.结果表明: 与无结皮相比,黄绵土藓结皮的脲酶、碱性磷酸酶、蔗糖酶和蛋白酶活性分别提升了2.4、7.6、20.7、2.4倍,而风沙土藓结皮的这4种水解酶活性分别提升了3.5、22.2、22.3、2.0倍;黄绵土和风沙土藓结皮的体积含水量分别降低了6.5%和0.8%,温度分别降低了0.8和2.5 ℃;黄绵土藓结皮的有机质、碱解氮和速效磷含量分别提升了2.5、2.9和3.6倍,风沙土分别提升了3.6、3.0和6.6倍.4种水解酶的活性与土壤养分含量呈显著正相关,与土壤含水量呈显著负相关;而土壤温度与脲酶活性呈显著正相关,与蛋白酶活性呈显著负相关.黄土高原水蚀风蚀交错区2种土壤藓结皮均能显著提升水解酶活性,这是藓结皮加速土壤养分周转的重要因素;通过改变土壤含水量和温度等酶促反应条件间接影响酶活性,是藓结皮促进土壤酶活性的重要途径.     

The activity of the red blood cell Ca pump is decreased in hemolytic anemia of the beagle dog

A mild hereditary nonspherocytic anemia in Beagle dogs was studied. Compared to RBCs from normal dogs, RBCs from hemolytic Beagles were larger on average, contained more potassium, and exhibited an approximately 50% decrease in rate of loss of ATP induced by Ca and the ionophore, A23187. Under certain conditions, this rate of ATP loss can be taken as a measure of the Ca pump ATPase activity of intact RBCs. From RBC fractionation studies it appeared that the defective Ca pump ATPase was acquired during the relatively short life-span of the hemolytic RBC. Significant loss of Ca pump ATPase may be causally related to the hemolytic anemia. The mechanism(s) by which Ca pump ATPase activity is lost in this hemolytic anemia remain(s) to be determined.     

THE KINETICS OF PENETRATION : XV. THE RESTRICTION OF THE CELLULOSE WALL

When Valonia cells are impaled on capillaries, it is in some ways equivalent to removing the comparatively inelastic cellulose wall. Under these conditions sap can migrate into a free space and it is found that on the average the rate of increase of volume of the sap is 15 times what it is in intact cells kept under comparable conditions. The rate of increase of volume is a little faster during the first few hours of the experiment, but it soon becomes approximately linear and remains so as long as the experiment is continued. The slightly faster rate at first may mean that the osmotic pressure of the sap is approaching that of the sea water (in the intact cell the sap osmotic pressure is always slightly above that of the sea water). This might result from a more rapid entrance of water than of electrolyte, as would be expected when the restriction of the cellulose wall was removed. During the linear part of the curve the osmotic concentration and the composition of the sap suffer no change, so that entrance of electrolyte must be 15 times as fast in the impaled cells as it is in the intact cells. The explanation which best accords with the facts is that in the intact cell the entrance of electrolyte tends to increase the osmotic pressure. As a consequence the protoplasm is partially dehydrated temporarily and it cannot take up more water until the cellulose wall grows so that it can enclose more volume. The dehydration of the protoplasm may have the effect of making the non-aqueous protoplasm less permeable to electrolytes by reducing the diffusion and partition coefficients on which the rate of entrance depends. In this way the cell is protected against great fluctuations in the osmotic concentration of the sap.     

Structural, physical and chemical characteristics of Microcystis aeruginosa hyperscums from a hypertrophic lake

SUMMARY. 1. This paper examines the structural, physical and chemical characteristics of cyanobacterial hyperscums (floating scums of densely packed eyanobacteria. measuring decimetres in thickness, that are covered by a dry crust of photo-oxidized cells) from hypertrophic Hartbeespoort Dam, South Africa. 2. The hyperscum community was a cyanobacterial-baclcrial association, in which the cyanobacterium Microcystis aeruginosa comprised 98% of the biovolumc, with cell concentrations exceeding 10⁹ ml^?1. 3. The buoyancy mechanism of M. aeruginosa and evaporation at the surface led to increasing compaction of the colonies with declining distance from the surface, and the formation of three distinct, but continuous layers: a 1–2 mm dry surface crust (water content: 14%, chlorophyll a concentration: 3 g l^?1), a 5–10 mm compact layer just below the crust (77% water, 1 g l^?1 chlorophyll a), and a less compact layer (96% water, 200–500 mg l^?1 chlorophyll a) from about 1 cm depth to the bottom, comprising the bulk of the hyperscum. 4. The crust attenuated all the incident light and reduced free gas exchange. Beneath it continuously dark anaerobic, highly reduced conditions prevailed. As the hyperscum aged over 3 months in 1984, at 10 cm depth the pH gradually declined from 6.6 to 5.9, interstitial water ammonia-N concentrations increased from 0.45 to 119 mg l^?1, soluble reactive phosphorus from 2.8 to 83.3 mg l^?1, and dissolved organic carbon reached a maximum of 460 mg l^?1. At any point in time these concentrations declined gradually with increasing depth within the hyperscum, and declined dramatically beneath the hyperscum. Similar patterns were recorded in another hyperscum in 1986. 5. The chemical and temperature depth profiles indicated that free water movement took place around and under the hyperscum, but within it water movement was restricted to diffusion. 6. Gas bubbles composed of 28% methane. 19% CO₂, 53% N₂, and traces of H₂ trapped within the hyperscum, and the presence of volatile fatty acids in the interstitial water were indicative of anaerobic decomposition processes mediated by fermenting and methanogenic bacteria, and N:P ratios below 1.5 in the interstitial water suggested that nitrogen was lost as gas, possibly through denitrification. 7. We hypothesize that the major sites of decay of M. aeruginosa were the crust and the compact layer beneath it, while deeper within the hyperscum this cyanobacterium could survive prolonged periods of dark anaerobic conditions. This hypothesis requires confirmation.     

Bone marrow colony-forming capacity in mice subjected to burn trauma]

A method of exogenous splenic colonies was applied to the study of the dynamics of the content of the colony-forming units (CFU) in the bone marrow of CBA mice to which thermal burn of the III degree of 15% of the body surface was inflicted. On the 4th and 16th days after the burn the CFU content in the bone marrow of mice decreased 1.7-2.1 times. The thymus cells of the intact mice administered simultaneously with the bone marrow of the burned mice increased, the amount of the splenic exogenous colonies formed in the recipients. The data obtained permitted to make a suggestion that not only the CFU count diminished in the bone marrow in the burned animals, but also the thymus-dependent cells necessary for normal colony formation.     

Suspension and settlement of particles in flowing water: comparison of the effects of varying water depth and velocity in circulating channels

SUMMARY. 1. An experimental study is described, designed to test the hypothesis that the loss of particles from suspension in flowing water follows an exponential decay function, the exponent of which is influenced more by water depth than water velocity. Successive experiments employed suspensions of Lycopodium spores which were introduced into one of the FBA's circulating channels maintained at its Watcrston site, Dorset, under different combinations of water depth and pumping rate.
2. In each experiment, the concentration of introduced spores indeed declined exponentially through time. The bulked, transformed data-set also conformed well to a single regression against a common time scale and which explained over 94% of the accumulated variances.
3. The variance unexplained by the regression was apportioned among components distinguishing between experiments, experimental differences in starting concentration, water depth and pumping rate (velocity). This analysis revealed that, after elimination of different initial concentrations, only water depth produced a significant effect, through its relation to the settling velocity of the Lycopodium . Thus, the hypothesis was not invalidated: water depth and not Row velocity proved to be the main controlling variable determining the rale of sinking loss in these experiments. Flow velocity is, nevertheless, an important component only in the sense that it influences the horizontal distance travelled by the residual spore suspension through the time period required for complete settlement.
4. The consequences of experimental findings are applied to the maintenance of planktonic diatoms in rivers: both the survival of a potential growth inoculum and its downstream dispersion are strongly time-dependent and are enhanced by greater channel depths.     

The influence of the thermal factor on the antigenic properties of skin]

Results of immunochemical studies of normal and thermally-treated human skin in vitro showed at least 2 of 4-5 organospecific dermal antigens to be thermostable-they withstood heating at 100 degrees C for 3 minutes; 2 or 3 antigens were thermolabile. The thermostable antigens possessed electrophoretic migration in the field of alpha1- and gamma-globulins. The burn eschar was found to retain one of the two thermostable oranospecific antigens together with the loss of thermolabile antigen.