ACH50 Values Research Articles

Exploring the Role of Airtightness for Achieving Carbon Neutrality in Canadian Residential Buildings: A Streamlined Life Cycle Assessment

This study delves into the relationship between airtightness levels and the entire life cycle carbon emissions of buildings across diverse Canadian climates. With the 2020 update of the National Energy Code of Canada for Buildings, whole-building airtightness testing was introduced as an option, prompting discussions on its mandatory nature. Using a net zero target, our assessment unfolds in two phases. Initially, we employ three-dimension (3D) modeling in Revit to replicate a typical Canadian detached house’s architectural features and material compositions. Subsequently, the model was imported into One Click life cycle assessment (LCA) to set parameters such as lifetime, gross interior area, and annual electricity consumption. Our analysis is bifurcated into assessing climatic conditions in Edmonton, Toronto, and Vancouver, alongside examining code-specified airtightness levels. We compared annual energy loss per unit area at varying airtightness levels accounting for the general deterioration of airtightness in new buildings during the pre-service phase to pinpoint the optimal airtightness value (ACH50) during the design stage. The subsequent phase evaluated increased carbon emissions from material replacement to meet this optimal airtightness condition and passive energy savings. Findings underscore that designing airtightness to an ACH50 value of 1.0 is the most energy-efficient. Comparative analysis reveals that achieving carbon neutrality solely through increased envelope airtightness and passive energy savings, is viable in Edmonton (18.4 years) owing to regional energy source disparities. In contrast, Toronto and Vancouver necessitate active energy-saving devices to attain carbon neutrality over the design lifetime.

Effects of dietary thiamin (vitamin B1) on the growth performance, serum biochemical factors, immune response, and antioxidant activity of great sturgeon (Huso huso) juveniles.

The present research evaluated the positive effects of dietary thiamin (vitamin B1) levels on the growth performance, serum biochemistry factors, immune response, and antioxidant activity of great sturgeon (Huso huso) juveniles. Thiamin was included in diets with levels of 0 (control, T0), 7 (T7), 15 (T15), and 25 (T25) mg/kg diet. Measurements of thiamin levels in diets indicated that they contained 1.80 (T0), 8.02 (T7), 16.2 (T15), and 26.6 (T25) mg thiamin/kg feed. Sturgeon juveniles (240 individuals) with average weight of 44.8 ± 1.96g were distributed into 12 tanks, and fed with the experimental diets for 8 weeks. Final weight, body weight gain (%), specific growth rate, and feed conversion ratio (FCR) of great sturgeon were significantly influenced by dietary thiamin levels, and the maximum fish performance (P < 0.05) was obtained at a level of 15mg/kg diet. The trypsin, chymotrypsin, creatine kinase, lipase, α-amylase, and alkaline phosphatase activities were notably (P < 0.05) affected by the dietary thiamin levels. The glucose content was not significantly (P > 0.05) different among the experimental treatments. Diets supplemented with thiamine increased significantly (P < 0.05) triglyceride, cholesterol, and total protein levels accompanied with significant (P < 0.05) decreases in aminotransferase aspartate and alanine aminotransferase activities. Serum antioxidant enzymes were remarkably (P < 0.05) higher, while serum malondialdehyde was significantly (P < 0.05) lower in the thiamin-treated fish compared with the control group. Total immunoglobulin, lysozyme, and ACH50 values were significantly (P < 0.05) higher in fish fed with thiamin-supplemented diets than in the control group. The results of the present study demonstrated that dietary thiamin have an important role in enhancing the growth performance, immune response, and antioxidant activity of great sturgeon. Based on the regression fitting curve of final weight, weight gain, specific growth rate, and FCR values, the optimal level of thiamin is found to be 15.0-17.5mg/kg diet.

Complement component 3 haplotypes influence serum complement activity and milk production traits in Chinese Holstein cattle.

Complement component 3 (C3) is the key molecule of the three pathways of complement activation (alternative, classical, and lectin pathways), which are involved in phagocytosis, inflammation, and immunoregulation processes to destroy infectious microorganisms. In this study, three novel single-nucleotide polymorphisms (SNPs) (g.-1293C>G located in the 5'-flanking region, g.56T>C in exon I, and g.7017C>T in exon XII) of the C3 gene were detected using created restriction site polymerase chain reaction, restriction fragment length polymorphism, and DNA sequencing in 952 cattle from three Chinese breeds. The genotypes and haplotypes were analyzed to investigate the polymorphisms and their possible implications, with particular investigative focus on their associations with serum C3 level, complement hemolytic activity (CH50 and ACH50), and milk production traits. The g.56T>C SNP in exon I affected the serum ACH50 (P<0.01) and the milk somatic cell score (SCS) (P<0.05), and the g.7017C>T SNP in exon XII significantly affected the serum ACH50 values (P<0.01). Moreover, statistical analyses revealed that individuals with genotypic combination CCC/GCC showed significantly lower SCS and the lowest C3 concentration in serum compared with cows with CCC/GTT (P = 0.0007) and CTT/CTT (P = 0.0021); the individuals with CCC/CCT had significantly higher ACH50 values than those with CCC/CTC (P = 0.0008) and CTC/GTC (P = 0.001); cows with CCT/CTT had higher values of CH50 and 305-day milk yield (P>0.05). The C3 expression levels were significantly increased in lung and mammary tissues (P<0.05), while significantly decreased in heart, spleen, liver, and kidney tissues in mastitis cows compared with those in healthy animals (P<0.01), respectively. Bacterial counts of serum antibacterial activities were also completed to verify the effect of SNPs on resistance to mastitis pathogens. Genetically resistant cows (CCC/GCC) had serum with noticeably higher antibacterial activity against S. aureus and E. coli in vitro than the genetically susceptible CCC/GTT cows (P<0.05). Results from this study imply that the C3 gene plays a role in resistance to bacterial infection and that it can be used as a molecular marker for complement activity and traits related to milk production.

An Analysis of ACHn for Improving the Performance of Green Remodeling through the Airtightness Measurements

Purpose: The study analyzed the airtightness of several buildings which were constructed more than 30, 20, 10 years ago and recently constructed by using various air leakage metrics. In addition, the various ACHn values were estimated in which it is not possible to maintain the reference pressure difference of 50 Pa due to some building conditions such as aged or large volume. Moreover, the relationship between the values of ACH 50 and ACHn was analyzed. Method: Two rooms in four different buildings were chosen and the air leakage rates were measured by using the fan-pressurization method based on ISO Standard 9972. For the measurement, both pressurization and depressurization test modes were applied twice. Various airtightness metrics were analyzed for the air leakages in each room. Result: The biggest air leakages were observed in the oldest building in which the ACH50 value was 24.35 h<SUP>-1</SUP>. Similar air permeability values were observed between the rooms in the buildings. Therefore, this metric can be used as a representative air leakage rate for the whole building. Moreover, the conversion coefficient for the ACHn values at different pressures from 4 Pa to 75 Pa based on the ACH50 value was estimated.

Efficiency of fatty acid-enriched dipteran-based meal on husbandry, digestive activity and immunological responses of Nile tilapia Oreochromis niloticus juveniles

This study aimed to compare the enrichment capacity of polyunsaturated fatty acids (PUFA) and the long chain polyunsaturated fatty acids (LC-PUFA) of two dipteran species, Hermetia illucens - black soldier fly (BSF) - and a blowfly, Chrysomya putoria (CP), and to test its influence on growth, digestive activities and immune responses of Nile tilapia. Two types of enriched insect larval meal were produced using larvae cultured either on vegetable substrates (VGS) to formulate two diets rich in linolenic acid (ALA) (BSF/VGD and CP/VGD), or on fish offal substrates (FOS), in order to produce two diets rich in ALA and eicosapentaenoic acid (EPA) (BSF/FOD) or in ALA + EPA and docosahexaenoic acid (DHA) (CP/FOD). These four insect-based diets containing only palm oil as a lipid source were compared to a control diet based on fish meal (FM) and fish oil (FO). After 60 days of feeding, ALA or DHA muscle content of fish fed BSF/VGD or CP/FOD diet was comparable to that of the FMFO diet, and all insect diets increased the EPA muscle levels, except for a reduction by the BSF/VGD one. The CP/FOD diet induced similar fish growth, feed efficiency and protein efficiency ratio compared to the control FMFO diet, while a decrease was observed in fish fed other insect diets. Only BSF/VGD led to a decrease in protein and lipid digestibility. CP or BSF larval meal significantly increased alkaline phosphatase activity regardless of fatty acid (FA) enrichment. The expression level of fads2, fads6 and elovl5 was significantly higher in fish fed the BSF/VGD diet compared to fish fed the FMFO diet. FA-enriched insect diets increased some immune variables such as lysozyme, peroxidase and ACH50 values of fish fed CP/FOD, CP/VGD or BSF/VGD diets. Moreover, the expression level of β-defensin-1 and mhcII genes were significantly higher in fish fed the BSF/FOD diet than the FMFO diet. Also, the expression of the pro-inflammatory gene il-1-β was significantly higher in fish fed FMFO diet than in those fed CP/FOD diet, but comparable to fish fed all other diets. No significant effects were observed for the other tested genes. The results showed a better efficiency in LC-PUFA enrichment of the CP larvae compared to BSF ones, resulting in a higher stimulation of the fish nutrient utilization processes and therefore, a higher growth capacity. Nonetheless, all dipteran larval meal stimulated the immune status whatever the insect species or dietary essential fatty acids.

Total replacement of fish meal by enriched‐fatty acidHermetia illucensmeal did not substantially affect growth parameters or innate immune status and improved whole body biochemical quality of Nile tilapia juveniles

The study was designed to evaluate the effects of total remplacement of fish meal (FM) and fish oil (FO) by vegetable oil and black soldier fly (BSF) larval meal enriched with fatty acids (FAs) in Nile tilapia juveniles. Fish were fed a FMFO control diet compared to a non-FA-enriched BSF diet (BSF/T0) and diets enriched in linolenic acid-ALA (BSF/T1) or in eicosapentanoic acid-EPA (BSF/T2). After 59 days, the BSF diets did not affect growth except for a decrease by the BSF/T1 diet. However, protein utilization and digestibility were reduced by all the BSF diets. FA-enriched diets did not improve the digestive enzyme activities or immune parameters, while lysozyme and ACH50 values were increased by the BSF/T0 diet. Levels of polyunsaturated FAs in the whole body of fish fed ALA or EPA-enriched BSF diets were comparable to those of FMFO controls. The results demonstrate that BSF meal can totally replace FM without substantially effect on growth or innate immune status. The decrease in fish carcass FA quality induced by the BSF meal can be prevented by a well defined protocol for PUFA enrichment. Nonetheless, investigation of the long-term effects of the BSF meal use during the ongrowing phase is still needed.

Factors influencing envelope airtightness of lightweight timber-frame houses built in the Czech Republic in the period of 2006–2019

In this research, 558 family timber-frame houses newly built in the period of 2006–2019 in the Czech Republic were assessed in terms of their airtightness. The air leakage through the building envelope was evaluated via the ‘blower-door’ method, and the most important parameters affecting the airtightness of these types of buildings were simultaneously evaluated. In low-energy houses with natural ventilation, the mean air change rate at a pressure difference of 50 Pa (ACH50) was ascertained as 1.03 h−1, and in low-energy houses with mechanical ventilation and heat recovery, the average ACH50 value was 1.07 h−1. Passive houses had an average ACH50 value of 0.44 h−1. The positive effects of mandatory regulations and government subsidies were demonstrated. The ACH50 values improved with each new year of construction; this trend was especially evident for low-energy houses. A very significant influence was also found from the company conducting the construction and the construction technology being employed; an on-site construction method achieved lower ACH50 values than a method based on panel construction with a higher degree of prefabrication. The ACH50 values were also affected by the presence of a chimney and/or type of the interior airtight vapour barrier. In particular, a brick chimney body impaired the ACH50 values. Timber-frame houses with a vapour-permeable air barrier systems generally had smaller air leakage rate values than houses with a polyethylene vapour barrier. However, neither the internal building volume nor the envelope area were found to be significant parameters in terms of airtightness for the lightweight timber-frame residential houses.

Waterborne Phenanthrene Modulates Immune, Biochemical, and Antioxidant Parameters in the Bloods of Juvenile Olive Flounder

The current study aimed to evaluate potential effect of waterborne phenanthrene (Phe) on immune, biochemical, and antioxidant parameters in the blood of juvenile olive flounder (Paralichthys olivaceus). Juvenile olive flounder were exposed to different concentrations (control, 0.1, 0.5, and 1.0 μg L-1) of Phe for 14 days and bloods were sampled at day 7 and 14. Hematological (alternative complement activity, ACH50; lysozyme; total immunoglobulin, Ig; cortisol; Hemoglobin, Hb; red blood cell, RBC; white blood cell, WBC), biochemical (glucose; albumin; alanine aminotransferase, ALT; aspartate aminotransferase, AST; alkaline aminotransferase, ALP), lipid peroxidation marker malondialdehyde (MDA), and antioxidant (glutathione, GSH; catalase, CAT; superoxide dismutase, SOD) parameters were evaluated in the blood samples. ACH50, lysozyme, Ig, and WBC values were significantly decreased by 1.0 μg L-1 of Phe at day 14, while cortisol level was significantly increased by 0.5 and 1 μg L-1 of Phe at day 14. Total protein concentration was significantly decreased in the 1.0 μg L-1 Phe-exposed blood sample at day 7 and 14. Values for ALT, AST, and ALP were significantly increased in response to 0.5 and 1.0 μg L-1 of Phe at day 14. There was no significant change in Hb, RBC, albumin, and glucose upon Phe. MDA content was significantly increased by 1.0 μg L-1 of Phe at day 14. GSH content was significantly elevated upon 1.0 μg L-1 of Phe at day 7, while the content was significantly depleted at day 14. The enzymatic activities of CAT and SOD were significantly increased by 0.5 and 1.0 μg L-1 of Phe at day 14. The results indicate significant modulatory effects of waterborne Phe on immune, biochemical, and antioxidant parameters in the economically important fish. The modulations can be used as potential biomarkers in Phe-contaminated aquatic environment.

Airtightness of electrical, mechanical and architectural components in South Korean apartment buildings using the fan pressurization and tracer gas method

The purpose of this study is to measure airtightness of building components in newly constructed apartment buildings in South Korea. For the measurements, electrical, architectural and two mechanical components regarding water and air systems were categorized and air leakage rates of these parts were measured by the blower door test. In addition to these building components, air leakage rates on the entrance door and three different building heights were analyzed. Moreover, the results obtained by the blower door test were compared with the tracer gas measurements. As a result, the air leakage rates (ACH50) were between 0.7 and 1.0 h−1, when all parts were sealed. When unsealing all parts, the ACH50 values ranged from 1.6 to 2.7 h−1. In addition, the ACH50 values were highly influenced by the entrance door and window systems. By improving the windows and the entrance door, the air leakages can be significantly reduced in residential buildings. Furthermore, the comparison results obtained by the tracer gas and blower door showed that artificially produced pressure difference condition can cause the overestimated ACH value.

The role of air tightness in assessment of building energy performance: Case study of Lithuania

The aim of this work was to evaluate the reliability of building energy performance methodology and to determine the significance of the building air tightness.This paper presents a study on the significance of the building air tightness for 27 single-family detached houses, which were built in Central Lithuania during 2007–2011. Results of the field study and calculations indicated that air tightness of A class buildings corresponded to regulation requirements, ACH50≤0.6 (air changes per hour at a 50Pascal pressure difference between interior and exterior). There was a large variation in respect of B and C class buildings. The 90% confidence interval of ACH50 value was between 4.17 and 8.05. The results showed that Lithuanian buildings of B and C energy performance class were not sufficiently tight. The average the air change rate, when air pressure of 50Pa was present, was 2 times higher than the regulatory value (ACH50=3 air change per hour). This work presents the ACH50 values' distribution according to the qualifying indicator Cq for A, B, C class buildings. Part of the presented ACH50 values of B class buildings are close to the value applicable to C class buildings. When air tightness of the buildings is evaluated, B energy performance class buildings can turn out to be C class.Results of an existing building's energy performance calculations are reliable only after verifying that the building is air tight. Otherwise, the actual heating energy consumption in buildings can significantly differ from the value calculated as per regulations if air tightness is ignored.

Immunomodulatory effect of cimetidine in common carp (Cyprinus carpio L.)

The main indication of cimetidine is being H₂-receptor antagonist, but studies suggest that cimetidine may also act as a non-specific stimulant of cell-mediated immunity and immunomodulator. In order to determine the immunomodulatory effect of dietary intake of cimetidine in the common carp (100 ± 10 g), subjects were fed diets containing 0 (control), 50, 100 and 200 mg cimetidine kg⁻¹ of dry diet for a period of 6 weeks. TLC and NBT assays were significantly (P < 0.05) stimulated in cimetidine-supplemented groups displaying the highest value in 200 mg kg⁻¹ group. A decrease (P < 0.05) in cortisol and ACH50 value was recorded in fish treated with cimetidine. Serum protein, albumin and serum globulin levels were not significantly changed. The findings of the present investigation suggest that the incorporation of cimetidine in the diet of common carp enhances the non-specific immunity.

06/02209 Synthesis of industrial utility systems: cost-effective de-carbonisation: Varbanov, P. et al. Applied Thermal Engineering, 2005, 25, (7), 985–1001.

The aim of this work was to evaluate the reliability of building energy performance methodology and to determine the significance of the building air tightness.This paper presents a study on the significance of the building air tightness for 27 single-family detached houses, which were built in Central Lithuania during 2007–2011. Results of the field study and calculations indicated that air tightness of A class buildings corresponded to regulation requirements, ACH50 ≤ 0.6 (air changes per hour at a 50 Pascal pressure difference between interior and exterior). There was a large variation in respect of B and C class buildings. The 90% confidence interval of ACH50 value was between 4.17 and 8.05. The results showed that Lithuanian buildings of B and C energy performance class were not sufficiently tight. The average the air change rate, when air pressure of 50 Pa was present, was 2 times higher than the regulatory value (ACH50 = 3 air change per hour). This work presents the ACH50 values' distribution according to the qualifying indicator Cq for A, B, C class buildings. Part of the presented ACH50 values of B class buildings are close to the value applicable to C class buildings. When air tightness of the buildings is evaluated, B energy performance class buildings can turn out to be C class.Results of an existing building's energy performance calculations are reliable only after verifying that the building is air tight. Otherwise, the actual heating energy consumption in buildings can significantly differ from the value calculated as per regulations if air tightness is ignored.

The effect of vaccination and sea water entry on immunocompetence and susceptibility to Kudoa thyrsites in Atlantic salmon ( Salmo salar L.)

The effect of intraperitoneal (IP) vaccination and sea water entry (SWE) on the immunocompetence of Cascade Atlantic salmon was investigated. Smolts were IP injected with Aqua Health's Forte™ vaccine ( Listonella ( Vibrio) anguillarum, Listonella ordalii, Vibrio salmonicida and Aeromonas salmonicida) at four times (42, 238, 433 and 630 degree days, DD) prior to SWE and were examined for immunocompetence. Immune response measurements included mitogen-driven proliferation of peripheral blood leukocytes (PBL), head kidney leukocyte respiratory burst activity and alternative complement hemolytic titres and were measured 24 h prior to SWE, 72 h post-SWE and again 3.5 weeks post-SWE. A 50% reduction in the number of PBL was observed 3 days post-vaccination. At this time LPS-driven proliferation was low (stimulation index, SI, 1.5–2.9) in all groups prior to SWE compared with that of PBL from freshwater-reared Atlantic salmon parr (6.7). By 72 h and 3.5 weeks post-SWE, the LPS-driven SI from unvaccinated salmon and those vaccinated 630 and 433 DD prior to SWE increased 3-fold. In contrast, SI from salmon vaccinated 42 and 238 DD prior to SWE remained low. A similar pattern was observed for cultured PBL stimulated with PHA, although unlike LPS-stimulated PBL, the SI of cells from parr and unvaccinated control smolts remained low following SWE but increased in fish vaccinated 433 and 630 DD prior to SWE. The respiratory burst activity of head kidney leukocytes was not affected by SWE but showed a transient 50% depression 3 days post-vaccination. The alternative complement activity (ACH50) was similar for all treatment groups prior to and at 72 h post-SWE. By 3.5 weeks post-SWE, ACH50 values in salmon vaccinated 42 and 238 DD prior to SWE doubled to 874 and 860 U/ml, respectively. The prevalence and severity of Kudoa thyrsites infections, detected in all treatment groups approximately 2400 DD following SWE, were not significantly different among groups. Atlantic salmon parr should be IP vaccinated no earlier than 433 DD before SWE to avoid an enhanced risk of acquiring pathogens because of transient depression in some immune mechanisms.

The changes of complement activities in sera of mice after subcutaneous administration of beryllium chloride

We studied changes of the complement pathway activities and the content of C3 in sera of mice, administered BeCl2 (containing 5 micrograms of Be per mouse) or CuCl2 (containing 5 micrograms of Cu per mouse) by a single subcutaneous injection. The value of the classical complement pathway activity (CH50) of the Be group 3 days after administration was significantly higher than that of the control group (P < 0.001). It was significantly lower than in the control group after 7 days (P < 0.001). On the other hand, the CH50 value of the Cu group 3 hr after administration tended to increase, however, it was significantly lower than in the control group after 7 days (P < 0.01). The change of the alternative complement pathway activity (ACH50) value of the Be group was similar to the change of the CH50 value of the group. The ACH50 value of the Cu group 3 days after administration tended to increase but it was the same as the ACH50 value of the control group after 7 days. The C3 contents of both the Be and Cu groups 3 days after administration were significantly higher than in the control group (P < 0.001). The aspartate aminotransferase (AST) activity of the Be group 7 days after administration was significantly higher than that of the control group (P < 0.01). By contrast, AST activity of the Cu group 3 hr after administration was significantly higher than in the control group (P < 0.05). The value of the alanine aminotransferase (ALT) activity of the Be group was low (P < 0.01), but that of the Cu group was high (P < 0.05), 3 hr after administration. These values of both groups after 7 days, however, were significantly higher than in the control group (P < 0.05). The AST/ALT ratio in mice was very high at 3 hr, and it remained high by 7 days after Be injection. On the other hand, the ratio of the Cu group was almost constant for 7 days after Cu injection. Thus, these values changed with relative expedition after Be injection. Therefore, we confirmed that measurements of complement activities and the content of C3 were valuable indices for assaying acute effects of Be on mice.

Optimum conditions for the activation of the alternative complement pathway of a cyprinid fish (Tinca tinca L.). Seasonal variations in the titres

The present work describes the existence of a haemolytic activity in the serum of tench, Tinca tinca, against rabbit red blood cells (RRBC) which was identified as belonging to the alternative complement pathway from the following findings: haemolytic activity disappeared when the serum was heated to 45°C for 20 min; 10 mM EDTA, which chelates Ca2+ and Mg2+, induced a complete loss of haemolysis; Mg2+, but not Ca2+, was required for the activity, and the use of sheep red blood cells (SRBC), which have a high content of sialic acid, resulted in the serum activity falling to a very low degree of haemolysis. The ACH50 value (units ml-1 serum) was defined as the reciprocal of the serum dilution necessary to lyse 50% of 4 × 107 RRBC in a buffered medium of normal ionic strength (μ=0·15) containing 10 mM EGTA and optimum concentrations of Mg2+. The optimum conditions for the ACH50 assay were: pH 7·2-7-7; reaction temperature, 15°C; concentration of Mg2+, 5 mM; and reaction time, 90 min. Under these conditions, the values of ACH50 in spring, summer, autumn and winter for male tench were 69±13, 91±22, 90±36 and 137±41, and for female tench 100±11, 108±13, 82±12 and 145±17. The highest serum activity was found in the winter, suggesting the importance of this pathway during cold periods when the specific immune response is depressed in ectothermic vertebrates.

Estimation of the genetic variation in complement activity of common carp (Cyprinus carpio L.)

The complement status of hybrid, laboratory raised carp was determined by an in vitro approach of the alternate complement activity (ACH50) and total haemolytic activity (CH50), and by measurement of serum C3 levels. The lysis of target sheep red blood cells (RBC) in the haemolytic assay for CH50 activity depended, amongst others, on the haemolysin concentration in the assay. Rocket electrophoresis showed a mean serum C3 concentration of 0.95 mg ml-1. The variation for both ACH50 and CH50 haemolytic activity was approximately 30%. The degree of genetic determination of the parameters was investigated by estimation of their repeatabilities, which were relatively high for CH50 (0.71) and ACH50 activity (0.72), but lower for C3 levels (0.54). Correlations between ACH50 values and C3 levels were significant, but moderate (0.54-0.58).

A study of the humoral immunity of mice injected with beryllium chloride

We studied changes of humoral immunity, such as complement pathway activity, C3 contents and contents of immunoglobulin, in mice injected subcutaneously with BeCl2 or CuCl2 once a week for 12 weeks. Mean body weights of JCL: ICR female mice were approximately 30g in control mice (control group; n = 7), in mice injected with Be (Be group; n = 8) and in mice injected with Cu (Cu group; n = 8). Values of classical complement pathway activity (CH50) were 18.8 +/- 1.4 U per ml, 15.3 +/- 1.8 U per ml and 16.7 +/- 1.3 U per ml in the control group, Be group and Cu group, respectively. The CH50 values of Be and Cu groups were significantly lower than that of the control group (P < 0.01). In contrast, values of alternative complement pathway activity (ACH50) and contents of C3 were almost constant in the three groups. The immunoglobulin content in the Be group tended to increase. The activity of alanine aminotransferase in the Be group was markedly higher than that in the control group (P < 0.05), and the aspartate aminotransferase activity was also high. The CH50 value of mice injected with a small amount of Be once a week over a 12-week period decreased markedly, although either the ACH50 value or C3 content was the same as in the control group. The immunoglobulin content somewhat increased in the Be group. These results suggest the possibility that immune complex is induced by Be.

主要養殖魚の補体代替経路活性の測定法について

Methods for assaying the alternative complement pathway activity (ACH50) of rainbow trout Salmo gairdneri, ayu Plecoglossus altivelis, carp Cyprinus carpio, tilapia Tilapia nilotica, eel Anguilla japonica, yellowtail Seriola quinqueradiata, porgy Pagrus major and flounder Paralichthys olivaceus sera were investigated.The ACH50 values of the sera of all fish except eel could be measured by incubating each serum with rabbit red blood cells (target cells) at 20°C in the presence of 10mM EGTA and 10mM MgCl2. The pH values and incubation periods employed were: rainbow trout, pH 7.0, 1.5h; ayu, pH 7.0, 1.5h; carp, pH 7.5, 1.5h; tilapia, pH 7.0, 1.5; yellowtail, pH 7.0, 2.5h; porgy, pH 7.5, 2.0h; flounder, pH 7.5, 2.0h. The hemolytic activity of eel serum was not reduced even in the presence of 10mM EDTA, suggesting the participation of unknown factor(s) in the hemolysis. Therefore, titration of the ACH50 value of eel serum was not carried out.ACH50 values (unit/ml, mean±SD, n=3 to 24) of the above 7 species were as follows: rainbow trout, 456±88; ayu, 880±376; carp, 51±14; tilapia, 684±560; yellowtail, 1016±56; porgy, 328±188; flounder, 508±60. These values are 5 to 60 times higher than those reported for mammals, suggesting that the role of the alternative pathway is much more important in fish than in mammals.

マダイ血清の代替経路による溶血補体価（ＡＣＨ５０）

Alternative complement pathway activity (ACH50) of porgy serum was measured by in-cubating the serum with rabbit red blood cells (RaRBC) in the presence of 10mM EGTA. It was confirmed that the concentration of EGTA (10mM) is enough to prevent the activation of the classical pathway of porgy complement, and that among red blood cells from several animals, RaRBC is the most effective activator of the alternative pathway of porgy comple-ment. Optimum conditions for the hemolytic reaction were: reaction temperature, 15°C; reaction time, 120min; pH 7.8; concentration of Mg2+, 10mM. When determined under these conditions, the ACH50 values of the sera from 33 porgy, weighing 23-31g, were remarkably high (143±81units/ml) as compared with those reported for mammalian sera.

Assay of classical and alternative pathway activities of murine complement using antibody-sensitized rabbit erythrocytes

Methods for measurement of classical complement pathway activity (CH50) and alternative complement pathway activity (ACH50) in mouse serum using rabbit erythrocytes sensitized with guinea pig anti-rabbit erythrocyte antibody have been established. The assays measured CH50 values in mouse sera that could hardly be determined by the conventional method using antibody-sensitized sheep red blood cells. Mouse serum ACH50 values determined by the method were also 5–7 times higher than those obtained in conventional assays with rabbit erythrocytes. Both the CH50 and ACH50 values varied with the strain among the 25 different strains of mice studied. BALB/c (nu/nu, ♂), LT/SuJ and JcL-ICR27 strains exhibited higher CH50 values, and NIH (nu/+), ICR (nu/nu), NOD (♂) and AKR strains showed lower values. The ACH50 was higher in C3H/HeN (♂), C57BL/6J (♂), Jcl-ICR27 and BALB/c (nu/nu, ♂) mice, and lower in ICR (nu/nu), NOD (♀) and AKR mice. Sera from 16 out of the 25 mouse strains showed ACH50 values comparable to or higher than those in man. As for CH50, however, even the highest value seen in BALB/c (nu/nu, ♂) mice corresponded to about three-fifths of an average value in man. It is concluded that the complement system of mice, especially the alternative pathway of complement activation, functions as actively as that in man. It was also found that male mice have higher CH50 and ACH50 values than female mice. The differences in these parameters between males and females were only slight at the age of 4 weeks and became conspicuous after 6 weeks at which time both the CH50 and ACH50 virtually reached their respective peak levels of activity.