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1.
Abstract: Serum and heparinized plasma samples were collected from 11 adult, clinically healthy llamas. Aliquots were assayed for sorbitol dehydrogenase (SDH) activity after storage at room temperature (20°C), 4°C, or −20°C for defined time intervals up to 1 week postcollection. Sorbitol dehydrogenase activity in all samples was within reference intervals for our laboratory. No difference was found between serum and plasma SDH activity when measured immediately (within 1 hour) after collection. Sorbitol dehydrogenase activity decreased to 79% of initial activity by 24 hours in serum stored at room temperature; plasma had 94% of initial SDH activity under the same conditions. Sorbitol dehydrogenase activity was stable in both plasma and serum stored for up to 1 week at 4°C or −20°C. With the exception of serum stored at 20°C for > 8 hours, in vitro stability of llama SDH was adequate for its use in diagnostic testing.  相似文献   

2.
Investigaltions to determine the effect of sample storage on the concentration of copper in liver tissue and on the activity of erythrocyte superoxide dismutase were undertaken in preparation for a study of blesbok (Damaliscus pygargus phillipsi) that were suspected to be suffering from copper deficiency. Two liver samples were collected from each of 20 culled blesbok in a manner that simulated the collection of biopsies from the live animal. These samples were stored either in 10% formalin or frozen at -20 degrees C until analysed 4 1/2 months later. The effect of different methods of sample storage on superoxide dismutase activity was determined. Erythrocytes collected from 3 Jersey cows and 5 culled blesbok were washed and divided into 0.5 ml portions, stored at room temperature (approximately 20 degrees C), in a refrigerator (4 degrees C), frozen at -20 degrees C in a freezer, and in liquid nitrogen (-200 degrees C). An analysis of superoxide dismutase activity was undertaken using a commercial assay kit at intervals of 2-4 days until the levels of activity had fallen significantly. The copper concentration in formalin-preserved liver samples was significantly lower than that measured in frozen liver tissue apparently as a result of leaching. The activity of superoxide dismutase in cattle blood was unchanged for 4 days at room temperature but fell appreciably after 2 days at 4 degrees C and -20 degrees C. Enzyme activity remained unchanged for 200 days in erythrocytes stored in liquid nitrogen. Superoxide dismutase activity levels in healthy blesbok were considerably lower than those measured in Jersey cows and remained unaffected for up to 6 days in samples stored at 4 degrees C and 20 degrees C. The level of activity fell significantly thereafter. Samples stored in liquid nitrogen were unchanged after 40 days.  相似文献   

3.
Nonenzymatic glycation of hemoglobin is a slow, continuous, and irreversible process which takes place during the whole lifespan of the erythrocyte. When hemolytic diseases are ruled out, the levels of glycated hemoglobins reflect the time-averaged serum glucose concentration for the preceding weeks. Canine hemoglobin also binds physiologically to intraerythrocytic glucose to form a glycated fraction which provides information on the animal's long-term glycemic status. This study describes an overall evaluation of ion-exchange microchromatography and thiobarbituric acid (TBA) colorimetry for the measurement of canine glycated hemoglobins. The intra- and inter-assay coefficients of variation (CVs) found were less than 5% in normal and diabetic canine samples, and both assays proved linear over the analytical range tested, which was wide enough to include the expected clinical values. Under our laboratory's conditions, the reference range for HbA(1) was 5.82 +/- 0.62% and for HbA(1)c was 2.35 -/+ 0.47%. Sample stability was lower using the ion-exchange procedure, with increases in HbA(1) observed after 4 days in whole blood and hemolysates stored at room temperature, after 12 days in whole blood stored at 4 degrees C, and after 7 days in hemolysates stored at 4 degrees C and -20 degrees C. In the case of TBA colorimetry, whole blood was stable for at least 21 days at room temperature and at 4 degrees C, and hemolysates were stable for 18 days at room temperature, at least 21 days at 4 degrees C, and up to 3 months at -20 degrees C.  相似文献   

4.
Background: A 35-day-old male lamb with Mycoplasma ovis infection (previously Eperyihrozoon avis ) was evaluated because of severe hypoglycemia (serum glucose 4 mg/dL, Hitachi 704 automated chemistry analyzer) inconsistent with the animal's condition. Whole blood glucose concentration measured with a glucometer was 74 mg/dL. Objective: The purpose of this study was to investigate this discrepancy through in vitro evaluation of the patient's blood.
Methods: Blood was incubated alone, with increasing concentrations of plasma, or with equine serum of known glucose concentration for 0,15, 30, and 60 minutes at room temperature; end-point glucose concentrations were compared with blood from a control sheep handled similarly.
Results: A rapid decline in glucose concentration was observed in heparinized or EDTA anticoagulated whole blood from the infected lamb incubated alone or with the equine serum. Glucose concentrations in incubated samples from a control sheep remained stable. Incubation of increasing concentrations of heparinized blood with autologous plasma resulted in decreased glucose concentrations in patient, but not control, blood. As parasitemia decreased after treatment, serum glucose concentration increased, serum lactate concentration decreased, and in vitro glucose concentration stabilized.
Conclusions: These findings are consistent with parasite-associated in vitro glucose consumption. An increase in the lamb's plasma glucose concentration associated with reduction of parasite load suggested excess glucose consumption also may have occurred in vivo.  相似文献   

5.
A specific radioimmunoassay was used to measure concentrations of hydrocortisone (cortisol) in the serum and plasma of 4 dogs. Differences (P greater than 0.05) in concentrations of cortisol were not found between serum and plasma (from EDTA-treated and heparinized blood samples). Differences (P greater than 0.05) in serum or plasma concentrations of cortisol were not found between samples stored at 4 C for various times (10 minutes, 10 hours, 40 hours) after collection, but before removal of RBC. In a study designed to determine the stability of cortisol in serum samples stored at room temperature, degradation was dependent on the initial serum concentrations of cortisol. Decreases (P greater than 0.05) did not occur in concentrations of cortisol in serum samples stored up to 15 days when initial concentrations of cortisol were less than 15 ng/ml. However, when initial concentrations of cortisol were approximately 55 ng/ml and 80 ng/ml, significant (P greater than 0.05) degradation occurred after 9 and 5 days of storage, respectively. Results of this investigation indicate that either serum or plasma of dogs is suitable for radioimmunoassay of cortisol and that samples (with and without added coagulants) incubated at 4 C may be left uncentrifuged for up to 40 hours without cortisol degradation. However, prolonged storage of serum at room temperature is detrimental, particularly for samples having large concentrations of cortisol.  相似文献   

6.
Bovine thyrotropin (bTSH) stimulation testing has long been considered the gold standard for diagnosis of canine hypothyroidism. Unfortunately, bTSH is no longer commercially available. Recently, the use of recombinant human thyrotropin (rhTSH) to perform thyroid-stimulating hormone (TSH) stimulation testing in dogs was described. The cost of an rhTSH vial (1.1 mg) limits the practical use of this product. The study reported here was performed to determine the effects of storing rhTSH on the post-TSH increase of serum total (TT4) and free (FT4) thyroxine concentrations during TSH stimulation testing in 12 euthyroid Beagles in a crossover trial. Three TSH tests with recombinant human thyrotropin (rhTSH; 91.5 microg IV) were performed on each dog during 3 different periods: 1 with freshly reconstituted rhTSH (fresh); 1 with rhTSH, reconstituted and stored at 4 degrees C for 4 weeks (refrigerated); and 1 with rhTSH, reconstituted and frozen at -20 degrees C for 8 weeks (frozen). Blood samples for determination of TT4 and FT4 concentrations were collected before and 4 and 6 hours after rhTSH administration. There was no significant difference in TT4 or FT4 concentration after stimulation with fresh, refrigerated, and frozen rhTSH. Furthermore, there was no significant difference between TT4 or FT4 serum concentration observed 4 and 6 hours after rhTSH administration. In conclusion, reconstituted rhTSH can be stored at 4 degrees C for 4 weeks and at -20 degrees C for 8 weeks without loss of biological activity, allowing clinicians to perform more TSH response tests per vial.  相似文献   

7.
To assess changes in 24 blood constituents in frozen serum and heparinized plasma, blood samples were drawn from 10 clinically normal German Shepherd army dogs. The storage characteristics of nine enzymes (ALP, ALT, amylase, AST, CK, GGT, GLDH, LDH, lipase), and 15 metabolites and minerals (albumin, bile acids, bilirubin, calcium, cholesterol, creatinine, fructosamine, glucose, magnesium, phosphate, potassium, protein, sodium, triglycerides, urea) were studied. Parallel samples of serum and heparinized plasma were stored for 90 and 240 days at two different storage temperatures, -200 degrees C and -700 degrees C. Sixteen of the 24 analytes (ALP, ALT, amylase, AST, CK, GGT, GLDH, LDH, bile acids, calcium, cholesterol, creatinine, fructosamine, magnesium, phosphate, urea) showed statistically significant (p < 0.05) changes during the storage period related to storage time, storage temperature, and sample type. Seven of the analytes (amylase, GGT, GLDH, LDH, bile acids, fructosamine, magnesium) showed changes of possible clinical importance with mean differences from baseline larger than 20% for the enzymes and 10% for the metabolites and minerals during the storage periods.  相似文献   

8.
BACKGROUND: A review of the literature revealed limited information about the stability of samples for coagulation testing in dogs. OBJECTIVE: The aim of this study was to evaluate the stability of individual coagulation factors, clotting times, and other parameters of hemostasis in stored canine plasma. METHODS: Citrated plasma samples were obtained from 21 dogs. Prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen concentration, and factor I, II, V, VII, VIII, IX, X, XI, and XII activities were measured on an automated coagulation analyzer with commercially available reagents. Antithrombin (AT) activity and D-dimer concentration were measured on an automated chemistry analyzer using validated kits. Samples were analyzed within 1 hour after collection (initial analysis) and once daily for 2 or 4 consecutive days following storage at room temperature (RT) or 4 degrees C, respectively. RESULTS: Storage time at either temperature did not have any effect on PT, factor II, V, VII, X, or XII activities, D-dimer concentration, or AT activity. In contrast, aPTT was significantly prolonged after 72 and 96 hours at 4 degrees C; fibrinogen concentration was decreased after 48 hours at RT; the activities of factors VIII and IX were decreased after 48, 72, and 96 hours at 4 degrees C; and factor XI activity was decreased after 72 hours at 4 degrees C. CONCLUSIONS: Results suggest that storage of canine plasma for 2 days at RT does not have a significant effect on hemostasis test results with the exception of a slight decrease in fibrinogen concentration. In contrast, aPTT and factors VIII, IX, and XI were unstable in refrigerated plasma after 48 or 72 hours of storage.  相似文献   

9.
The production of interferons in blood and milk leukocytes of three groups of cows was measured to determine the effect of 6-days cold treatment (-2 degrees to -8 degrees C) and/or starving. The first group (cold) was treated with low ambient temperature (-2 degrees C to -8 degrees C) 11 hours every day for 6 days, the second (cold and starved) was treated with low temperature and starved for 6 days. The third group (controls) was fed normally and kept in a barn at room temperature (18 degrees to 20 degrees C). The leukocytes of the control and the cold treated cows responded normally to interferon induction with Newcastle Disease Virus (NDV) and mitogens: phytohemagglutinin (PHA) and concanavalin A (ConA). The cows treated with low temperature and starved for 6 days developed biochemical blood changes of ketosis. Leukocytes of these cows with ketosis produced less interferon (p less than 0.05) than before starvation and less than leukocytes of the control cows and the cold treated cows. It can be assumed that ketosis caused by starving decreases the ability of a cow's leukocytes to produce interferons.  相似文献   

10.
The stability of serum ionized calcium concentration (ICa) from dairy cows was studied after anaerobic collection and frozen storage. Paired blood samples were obtained from five groups of cows: nonlactating, first third of lactation, midlactation, last third of lactation, and 2-year-old nonlactating heifers. Vacutainer multiple sample needles and serum separator tubes (SST) were used for venipuncture. Aspiration of serum was within 1.5 hours after collection: one sample for immediate determination (within 2 hours of collection); the other sample stored at -4 degrees C in evacuated plastic vacutainer tubes filled with serum to provide dead space of less than 75% of volume, and analyzed after 14 to 30 days in storage (half, 15, of the samples from each lactation group were analyzed after frozen anaerobic storage at 14 or 30 days, respectively). Processing samples in this manner significantly altered the values obtained for ICa, normalized calcium concentration (NCa), and pH. Analysis after frozen storage in evacuated tubes caused ICa and NCa concentrations to decrease and pH to increase (P< 0.05); total calcium levels were not significantly different from initial values. There were no significant differences among lactation groups. The difference between values obtained from these paired samples was either due to loss of CO(2) during transfer from the SST to the evacuated tube or during frozen storage. Changes in samples assayed after freezing and storage could be adjusted to original values by using the mean difference between the fresh and frozen levels as correction factors: ICa (+0.4379), NCa (+0.2797), and pH (-0.0926). It was concluded that immediate determination of serum ICa in dairy cattle is the ideal but using this methodology and performing analyses later may be acceptable if correction factors are determined.  相似文献   

11.
Paraoxonase-1 (PON-1) activity is a new inflammatory and oxidative marker. Technical effects and biological factors could affect the accuracy of PON-1 activity measurement. We investigated the effects of storage at different temperatures, repeated freeze–thaw cycles, interferences from hemolytic, lipemic, and icteric samples, and seasonal effects on PON-1 activity in horses. We evaluated 2 substrates with an automated spectrophotometer. Ten equine serum samples were stored under different conditions. Although storage at room (21°C) or refrigeration (4°C) temperature induced a statistically significant decrease (p < 0.05) in PON-1 activity, this is not diagnostically relevant. PON-1 activity in frozen samples (−20°C) was stable for short-term storage; diagnostically significant (p < 0.01) fluctuations were observed after 1 mo. Four repeated freeze–thaw cycles were assessed, and all cycles affected PON-1 activity (p < 0.01); however, this was diagnostically significant only after the 4th cycle. Hemolysis induced an overestimation of PON-1 activity; lipemia and hyperbilirubinemia did not change PON-1 activity. Thirty-four horses were sampled monthly for 1 y, and PON-1 activity was higher in autumn (p < 0.05) and winter (p < 0.05) than in spring and summer.  相似文献   

12.
The ability to ship cooled stallion sperm for subsequent freezing at a facility specializing in cryopreservation would be beneficial to the equine industry. Stallion sperm has been centrifuged, cooled to 5 degrees C for 12 h, and frozen without a detrimental effect on motility in a previous study; however, no fertility data were available. Experiment 1 compared the post-thaw motility of sperm cooled for 18 h at 15 or 5 degrees C at either 400 or 200 x 10(6) sperm/mL and then frozen. Storage temperature, sperm concentration, or the interaction of temperature and concentration had no effect on total (TM) and progressive motility (PM) after cooling. Post-thaw TM and PM were higher for control than (P < 0.05) for treated samples. There was no difference in post-thaw TM and PM due to temperature or concentration. Experiment 2 further evaluated procedures for cooling before freezing. Ejaculates were either cooled to 5 degrees C for 18 h and centrifuged, centrifuged at room temperature and then cooled to 5 degrees C for 18 h before freezing, or centrifuged and frozen immediately (control). There was no difference among treatments on post-thaw TM or PM. In Exp. 3, mares were inseminated with semen that had been extended in skim milk-egg yolk without glycerol, centrifuged, resuspended at 200 x 10(6) sperm/mL, cooled to 5 degrees C for 18 h, and then frozen or not cooled for 18 h before freezing (control). Pregnancy rates did not differ for mares receiving semen cooled and then frozen (21 of 30, 70%) or semen frozen directly without prior cooling (16 of 30, 53%). In summary, a procedure was developed for cooling stallion sperm for 18 h before freezing without a resultant decrease in fertility.  相似文献   

13.
BACKGROUND: Glutamate dehydrogenase (GLDH) is a mitochondrial enzyme with highest activity in periacinar hepatocytes. It is reported to be a sensitive indicator of hepatic injury; however, results of studies regarding tissue specificity are contradictory. OBJECTIVES: The purpose of the study reported here was to examine the effect of 3 factors on serum GLDH activity in dogs: serum storage, anti-inflammatory oral doses of prednisone, and spontaneous hyperadrenocorticism (HAC). METHODS: Stability of enzyme activity was determined by comparing serum samples stored at approximately 20 degrees C, 4 degrees C, and 20 degrees C for 4, 24, 48, and 72 hours, 1 week, and 6 months. To determine whether orally administered prednisone affected GLDH activity, the median difference in serum GLDH activity was compared between 5 untreated control dogs and 8 dogs that had received a tapering oral dose of prednisone. Lastly, GLDH enzyme activity was compared between 17 dogs with HAC and 16 age-matched controls. RESULTS: GLDH activity remained stable for 48 hours, 1 week, and 6 months, in serum stored at approximately 20 degrees C, 4 degrees C, and 20 degrees C, respectively. The median change in GLDH activity was not significantly different between dogs receiving prednisone and controls; however, dogs with HAC had significantly higher values than those of age-matched controls. CONCLUSIONS: Serum samples should be maintained at 4 degrees C if analysis of GLDH activity will be delayed by >48 hours; serum stored at 20 degrees C yields reliable results for up to 6 months. Serum GLDH activity was not increased in most dogs receiving short-term, anti-inflammatory oral doses of prednisone, in contrast to its increased activity in dogs with HAC.  相似文献   

14.
OBJECTIVES: To evaluate the consistency of partial pressures (P) of arterial oxygen (aO(2)), arterial carbon dioxide (aCO(2)) and pH measurements in equine carotid arterial blood samples taken into syringes made from three different materials and stored at room temperature or placed in iced water for measurement at three different times. STUDY DESIGN: Prospective observational study over 19 days. ANIMALS: Four clinically normal Thoroughbred or Thoroughbred-cross horses (three geldings, one mare, mean age 6.25 years, range 5-7 years). METHODS: Identical blood samples were taken on two separate occasions from the carotid arteries of the four horses into syringes made of glass, plastic and polypropylene. PaO(2), PaCO(2) and pH determinations were performed on blood from each syringe type at 10, 60 and 120 minutes post-sampling with samples stored at room temperature (approximately 20 degrees C) or in iced water (approximately 0 degrees C). Data were analysed by anova and a split plot model fitting syringe within horse X pair and time within temperature within syringe. RESULTS: Syringe material, storage temperature and time before analysis all had significant effects on PaO(2) (p < 0.001). PaCO(2) was unaffected by syringe material or storage temperature. However, over 120 minutes, storage duration significantly (p = 0.002) affected values. Temperature of storage and duration prior to analysis both significantly affected pH values (p = 0.005 and p < 0.001, respectively), but syringe material did not. Several significant interactions between these variables were noted. CONCLUSIONS: Equine arterial blood gas determination has a different sensitivity to storage conditions compared to other veterinary species. CLINICAL RELEVANCE: For accurate equine arterial blood analysis, PaO(2) samples need to be analysed within 10 minutes or taken into glass syringes, stored on ice and analysed at 2 hours post-sampling. PaCO(2) and pH measurements can be performed on samples stored in glass, plastic or polypropylene syringes at room temperature for up to 1 hour post-sampling.  相似文献   

15.
BACKGROUND: Blood typing before transfusion minimizes the risk of transfusion reactions and prevents immunization of the recipient against incompatible RBC antigens. The major RBC antigens that warrant identification before packed RBC or whole blood transfusions in horses are Ca and Aa. Standard blood-typing protocols are time-consuming (2.5-3.0 hours) and impractical in emergency settings. OBJECTIVES: The purpose of this study was to determine whether equine RBCs could be typed for Ca and Aa antigens using sera from horses with RBC antibodies in a modified rapid (15 minute) blood-typing protocol. METHODS: Serum was obtained from a horse with anti-Ca antibodies and from another horse with anti-Aa antibodies. The presence of agglutinating antibodies was confirmed with antibody screening. Venous blood samples, collected in citrate-phosphate-dextrose, were obtained from 21 horses of various breeds. Samples were blood typed in the Veterinary Medical Teaching Hospital Hematology Laboratory using standard methodology. Washed RBCs from each of the 21 horses were incubated individually with anti-Ca and anti-Aa sera at dilutions of 1:4, 1:8, and 1:16 for 15 and 30 minutes at room temperature and 37 degrees C. RESULTS: Of the 21 horses, 13 were identified as Aa+/Ca+, four were Aa+/Ca-, two were Aa-/Ca+, and two were Aa-/Ca-. All 17 Aa-positive horses had a positive agglutination reaction at all dilutions of anti-Aa serum, incubation times, and temperatures, while all Aa-negative horses were negative. Each Ca-positive horse had a positive agglutination reaction at all incubation time points and temperatures up to the 1:16 dilution of the anti-Ca serum. All Ca-negative horses were negative at all times, temperatures, and dilutions of anti-Ca serum. Use of the modified protocol on 26 hospitalized horses resulted in accurate typing, based on complete antibody screens. CONCLUSIONS: These results support the hypothesis that equine RBCs can be blood typed using a rapid (15 minute) protocol, at room temperature, for the presence of Ca and Aa antigens using equine-derived antisera. This technique may be beneficial for pretransfusion testing of equine patients in an emergency setting.  相似文献   

16.
After 14C-labelled cortisol infusion in ponies and pigs, faecal samples were collected. Extraction of 0.5 g faeces with 5 ml 80-90% methanol yielded the highest radioactivity in the supernatant. Most of the metabolites were ether soluble. After high performance liquid chromatography (HPLC), the presence of immunoreactive metabolites was demonstrated by measuring each HPLC fraction using enzyme immunoassays for cortisol, corticosterone and 11-oxoaetiocholanolone. Only the assay for 11-oxoaetiocholanolone revealed peaks with co-eluting radioactivity. For biological validation of the test system, adrenocorticotrophic hormone (ACTH) and dexamethasone were injected intravenously successively in both species (n = 6). Cortisol concentration in blood and the 11-oxoaetiocholanolone immunoreactive substances in faeces were determined. In horse faeces, basal values of 2.3-35.2 nmol/kg were measured. After ACTH administration, an increase (more than 200% above basal values) of these metabolites was seen about 1 day after ACTH administration. After dexamethasone injection the levels decreased, reaching minimum concentrations 2 days after administration. In pigs, an increase in these metabolites was measured in only three animals after ACTH; dexamethasone did not cause a decrease. The stability of the samples after defecation was tested by storing samples from cows, horses and pigs at room temperature. It was shown that there was a significant increase in the concentration of measured cortisol metabolites in bovine, equine and porcine faeces after storage for 1 h, 4 h and 24 h, respectively. In frozen samples this effect was diminished after thawing samples at 40 degrees C; thawing the samples at 95 degrees C prevented an increase in immunoreactive substances.  相似文献   

17.
Little is known about stability of hormones in blood samples stored under various conditions. This study was conducted to examine stability of triiodothyronine (T3), thyroxine (T4), luteinizing hormone (LH), prolactin, insulin, cortisol and progesterone in blood and serum samples. Experiment 1 was designed to determine if concentrations of these hormones were affected by exposure to cellular elements of anticoagulated and coagulated blood when stored at 4 C and room temperature (22 to 26 C). Jugular venous blood was collected from six diestrous Holstein cows into evacuated bottles containing sodium ethylenediaminetetraacetic acid (EDTA), heparin or no anticoagulant. Subsamples of EDTA-treated and heparinized blood were stored .25, .5, 1, 2, 4, 8, 24 and 72 h at 4 C or room temperature. Subsamples of blood without anticoagulant were stored in polypropylene tubes (clot tubes) or serum separator tubes for 1, 2, 4, 8, 24 ad 72 h. Mean concentrations of T3, T4, LH, prolactin and cortisol did not change in plasma or serum from either of the four types of samples stored at 4 C or room temperature for 72 h. The mean insulin concentration decreased 18% by 72 h in serum from serum separator tubes stored at room temperature. At 4 C, mean progesterone concentrations decreased 55% by 24 h and 73% by 72 h in plasma from EDTA-treated blood; 41% by 72 h in serum from clot tubes, and 26% by 24 h and 36% by 72 h in serum from serum separator tubes.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

18.
It has been previously shown that Ca(I) concentration is stable in serum collected from healthy horses for 10 days if stored at 40 degrees C. This may not be true for horses with abnormal Ca(I) concentrations. Thus the stability of ionized calcium (Ca(I)) concentration and pH measurement in serum from horses with both normal and abnormal Ca(I) concentrations stored for various times at 40 degrees C and -10 degrees C was evaluated. Our results indicated that serum Ca(I) concentration was stable throughout 7 days of cold or frozen storage, after being received by the Clinical Chemistry Laboratory. Serum Ca(I) concentration showed a significant decrease by 14 days of frozen storage (-10 degrees C). Serum pH showed a statistically significant increase by 7 days of cold storage, and within 3 days of frozen storage. If equine serum is collected, handled and stored anaerobically, and kept cold or frozen, Ca(I) concentration can be accurately measured for approximately 7 days after collection, regardless of the health status of the animal. An accurate measurement of pH may be made within 3 days of cold or 1 day of frozen storage.  相似文献   

19.
With the aim of evaluating the effect of freezing goat milk samples on recovery of intramammary pathogens, 1200 milk samples from udder halves with subclinical intramammary infection were studied. Samples (20 ml) were frozen at -20 and at -80 degrees C. Thawing was carried out at room temperature at 7, 14, 21, 28, 58, 118, 178, 236 and 730 days after collection and bacteriological analyses were carried out to determine the number of colony forming units/ml (CFU/ml). Mixed model statistical analysis showed that bacterial group, temperature of storage, interaction of bacterial group and temperature of storage and the interaction of bacterial group, time and temperature of storage were statistically significant effects. For coagulase negative staphylococci (CNS), least squares means of log CFU/ml recovered at -20 and -80 degrees C were not different. Nevertheless, for Gram negative bacilli (GNB) a significant decrease was detected in samples frozen at -20 vs. -80 degrees C. At both temperatures and at different times of storage, significant increases were detected between log CFU/ml of CNS and values on day zero. At -20 degrees C, a significant decrease in GNB recovery was detected between freezing days zero and 730. This difference was not detected when goat milk samples infected by GNB were frozen at -80 degrees C. The results show that frozen milk samples can be useful in goat subclinical mastitis control programs.  相似文献   

20.
OBJECTIVE: To investigate the activities of hyaluronidases in equine sera and synovial fluid samples and sera from fetal and adult bovids and evaluate the extent to which the degradation of hyaluronan is influenced by chondrocytes. SAMPLE POPULATION: Commercial and noncommercial samples of equine (n = 6) and bovine (6) sera and 16 synovial fluid samples from horses. PROCEDURE: Hyaluronidase activities in sera and synovial fluid samples were assessed via enzyme zymography (performed at pH 4, 5, 6, or 7). Chondrocytes were isolated from equine cartilage and cultured with or without hyaluronan (1 mg/mL); the degradation of hyaluronan was assessed via agarose gel electrophoresis. RRESULTS: Hyaluronidase activity was detected in equine sera and synovial fluid samples at pH 4, but not at pH 7, and in bovine sera at both pH values. In all samples at pH 4, a major band of activity (molecular weight, approx 60 kd) and some additional higher molecular weight bands were detected; high- and low-molecular-weight activities were detected in bovine sera at pH 7 Hyaluronan in tissue culture medium with or without fetal calf serum was degraded in the presence, but not the absence, of equine chondrocytes. CONCLUSIONS AND CLINICAL RELEVANCE: Hyaluronidase activity was detected in equine sera and synovial fluid at pH 4 and in bovine sera at pH 4 and 7. Primary chondrocytes in monolayer culture can degrade exogenous hyaluronan. Modulating native hyaluronidase activity may offer a new approach to improve the quantity and quality of hyaluronan in articular joints.  相似文献   

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