Clin Path Flashcards
Why is hypophosphatemia thought to be a cause of post-parturient hemoglobinuria?
Severe hypophosphatemia is though to cause a reduction in erythrocytes ability to produce ATP. This lack of ATP causes a loss of power of Na pumps, rendering the intracellular Na to rise. This causes the cell to become rigid and eventually burst as it moves through the capillary beds.
10.1111/jvim.12497
A study evaluated RBC phosphate concentration and osmotic resistance, to determine if hypophosphatemia was a cause of postparturient hemoglobinuria. What were the results?
Hypophosphatemia induced by dietary P depletion was neither assoc. with a decline in erythrocyte [P] nor with decreased osmotic resistance of erythrocytes P depletion alone is unlikely to cause intravascular hemolysis.
Also, dextrose infusion induced a decline of [P] but did not affect erythrocyte [P] nor osmotic resistance.
10.1111/jvim.12497
In a study looking at equine colic and the correlation between acute phase proteins (SAA, haptoglobin and fibrinogen) under the influence of demographics, disease processes, disease location, disease duration, hypovolemia and hospital admission, what were the results?
Concentration of APPs are assoc. mainly with disease process and duration of colic. The magnitude of the APP response is positively associated with the amount of tissue affected and the severity of tissue damage. SAA may be a diagnostic marker for use in colic differential diagnosis, but more research is needed.
10.1111/jvim.12542
Serum bile acids (SBA) and histological scores were evaluated in association with short and long-term survival in horses with hepatic disease. What hepatocellular changes were included in the histological scores?
Cell types, fibrosis, apoptosis, hemosiderin, bile duct proliferation, bile stasis, hepatocyte nuclei
10.1111/jvim.12551
Serum bile acids (SBA) and histological scores were evaluated in association with short and long-term survival in horses with hepatic disease. What provided the best prognostic indicator for long term survival?
Histological score
10.1111/jvim.12551
Procalcitonin (PCT) has been shown in human medicine to be a biomarker of SIRS. How does this occur?
PCT occurs from CALC-1 gene transcription and calcitonin-mRNA translation. It is restricted to neuroendocrine cells in the thyroid and has a low serum level in healthy patients. In states of inflammation, expression of CALC-1 is upregulated and PCT is released from many tissues and cells. Plasma PCT concentration rises rapidly within 3‐6 h, especially in response to bacterial infection and endotoxemia, seeming to be also an early marker of bacterial infection and endotoxemia in human patients.
10.1111/jvim.13640
When evaluating procalcitonin in horses with SIRS, compared to horses without SIRS, what were the results?
There was an increase in [PCT] in SIRS horses as previously reported in humans and dogs. It could be used as a single assay in equine practice for detectio of SIRS.
10.1111/jvim.13640
The Precision Xtra® meter is a promising low cost electrochemical point‐of‐care unit for measuring blood glucose concentration ([gluc]) in cattle blood. The meter uses an algorithm that assumes the intra‐erythrocyte [gluc] equals the plasma [gluc] on a molal basis, and that the hematocrit is similar in humans and cattle.
Was the meter accurate when measuring plasma glucose in dairy cattle?
The meter utilizes an algorithm that is optimized for human blood and is inaccurate when applied to bovine blood. Until a cattle‐specific algorithm is developed, we recommend using plasma as the analyte instead of blood and calculating plasma [gluc] using the equation: [gluc] = 0.66 × [gluc]p‐meter + 15, where [gluc]p‐meter is the value reported by the meter. If blood is measured, then we recommend using the equation: [gluc] = 0.90 × [gluc]b‐meter + 15.
10.1111/jvim.13608
When compared to humans erythrocytes, what did a study evaluating the efficacy of the Precision Xtra® meter for blood glucose reveal about cattle erythrocytes and [gluc]?
The major finding of the study reported here was that the intra‐erythrocyte [gluc] is low in blood from adult cattle and approximately 18% of the plasma [gluc] when expressed in molar units. This estimate indicates that bovine erythrocytes are not very permeable to glucose and contrasts with human erythrocytes, which are very permeable to glucose.
10.1111/jvim.13608
Novel biomarkers might improve the understanding of SIRS and aid diagnosis and determination of prognosis.
High motility group box 1 (HMGB-1) and nucleosomes have been studied in other species. Where do these come from?
HMGB-1 is a late phase cytokine of sepsis in other species.
Nucleosomes are disk‐shaped complexes made up of histones surrounded by DNA, which are released mainly during apoptotic cell death, and [ ] increase with sepsis in humans.
10.1111/jvim.13811
How did the novel biomarkers, HMGB-1 and nucleosomes, measure up when compared in horses with and without SIRS, and colic?
HMGB-1 and nucleosomes were significantly higher in inflamm and strangulating groups compared to healthy horses. Concentrations in the group with nonstrangulating disease did not differ from healthy horses.
10.1111/jvim.13811
What are antemortem diagnostics for DIC?
At least 3 abnormal test results (low platelet count, prolonged PT, prolonged APTT, low AT activity, low fibrinogen concentration or high D-dimer concentration) based on institution-derived reference intervals was the most sensitive method for determining outcome.
10.1111/jvim.13659
In a study evaluating horses before and after death for evidence of DIC, did the antemortem diagnostics correlate with postmortem histologic evidence?
No association was found between antemortem classification of coagulopathy and postmortem diagnosis of DIC based on tissue fibrin deposition. None of the hemostatic parameters was significantly different between horses with or without postmortem diagnosis of DIC. There was no association between horses with fibrin in tissues or different cut‐offs for D‐dimer concentration and postmortem evidence of DIC.
10.1111/jvim.13659
What are the four different components of the strong ion differences?
Cations - Na+, K+, Ca2+, Mg+
Anions - Cl-, lactate, sulfate, ketoacids
paCO2
Atot - plasma proteins
10.1111/jvim.13590
If measurement of [l‐lac−] is unavailable, what can be used as a surrogate test to detect hyperlactatemia in hospitalized foals?
AG and SIG could be used as surrogate tests. It is important to recognize that metabolic acidosis is produced by a decrease in the SID. The SID might be decreased by hyponatremia in presence of normochloremia or hyperchloremia, and hyper‐l‐lactatemia.
10.1111/jvim.13590
C-reactive protein concentration (CRP) and haptoglobin are well established biomarkers of infection in humans. How are they viewed in horses?
CRP is considered a minor APP that is moderately elevated in 3-7 d after an inflammatory event.
Haptoglobin is considered a minor APP that is moderately increased in 4-6 d of an inflammatory event
10.1111/jvim.12568
How can C-reactive protein concentration (CRP) and haptoglobin be used when evaluating neonatal foals for sepsis?
CRP increases with inflammation but is not indicative of sepsis. In this study, haptoglobin was lower in septic foals than in sick nonseptic foals.
10.1111/jvim.12568
When using the SIG method to evaluate diarrheic calves, what contributed most to a metabolic acidosis?
Hypophosphatemia and an unmeasured D-lactate accounted for 58% of the variation in venous blood pH and 77% of the variation in AG and SIG.
10.1111/jvim.12556
Increased [LAC] at hospitalization identified the severity or magnitude of hyperlactatemia in critically ill foals. The change in [LAC] over time also evaluates duration or persistence of hyperlactatemia in the face of treatment. Abnormal values of the aforementioned were assoc. with decreased survival. A study then looked at the area under the [L-lactate]-time curve in similar foals. What were the results?
LACarea was significantly larger in nonsurviving foals then in surviving foals. Further investigation is warranted because approximately 20% of all foals evaluated using LAC parameters are currently misclassified regarding survival to discharge.
10.1111/jvim.12559
Extracellular potassium represents what percent of total body K+?
Approximately 2% of total body potassium
10.1111/jvim.12559
Is the plasma [K+] representative of intracellular [K+]?
Plasma [K+] is only representative of intracellular [K+] if blood pH and [glucose] are within normal limits.
10.1111/jvim.12559
What are the potassium levels in diarrheic calves?
The calves tend to be overall potassium depleted, due to intestinal losses and decreased milk intake, but will register as normo/hyperkalemic.
10.1111/jvim.12559
What was the old adage when it came to why diarrheic calves were normo/hyperkalemic? What is the proposed theory now?
It was thought that diarrheic calves had a normal/high plasma [K+] due to buffering in a metabolic acidotic state and due to Na+/K+ ATPase impairment at a low pH.
It is now understood that dehydration and renal function impairment play a role plasma [K+]. An acidotic environment does encourage K+ out of the cell, but renal impairment decreases the body’s ability to excrete increased extracellular K+.
It was found that the presence of d‐lactataemia in acidemic calves resulted in significantly lower odds for hyperkalemia but significantly higher odds for the presence of hypokalemia. Since d‐lactic acidosis in neonatal diarrheic calves is not necessarily associated with clinical dehydration, the acidemia‐induced efflux of potassium ions could have been masked by the ability to eliminate potassium ions by the kidneys which would have resulted in marked K+ wasting during an ongoing acidosis.
10.1111/jvim.12559
What are some risk factors in diarrheic calves for developing hypokalemia?
Marked metabolic acidosis, low milk intake and a long history of diarrhea.
10.1111/jvim.12559
What are some other clinical effects of hyperkalemia in calves with diarrhea?
Lethargy, muscle weakness, cardiac arrhythmias, atrial standstill, increased QRS duration, clinical dehydration, cyanosis.
10.1111/jvim.12537
How do hypertonic sodium bicarbonate solutions (HBS) change plasma [K+]?
- High osmolarity causes immediate and sustained plasma volume expansion leading to a dilutional effect on plasma [K+]
- Enhances redistribution of K+ between the EC and IC spaces
10.1111/jvim.12537
In a study on alkalinization and rehydration on plasma potassium concentrations in neonatal calves with diarrhea, how did the administration of hypertonic sodium bicarbonate solutions lower the plasma K+?
- Increased in EC [HCO3-] enhanced cellular uptake by a Na+/HCO3- co-transporter for Na+/H+ exchange, which stimulated Na+/K+ ATPase and consequently net cellular K+ uptake
- Profound osmotically driven plasma volume expansion as indicated by marked decreases of total protein concentrations
- Hypertonicity has been proposed to result in an increase of intracellular K+ as a result of cellular dehydration which consequently provokes passive diffusion of potassium out of the cells. This effect was therefore discussed to counteract in part the desired plasma potassium‐lowering effect of hypertonic sodium bicarbonate
10.1111/jvim.12537
How does oxidative stress contribute to severe mammary tissue damage, during acute coliform mastitis?
Severe mammary tissue damage during acute coliform mastitis in cattle is partially caused by oxidative stress. Reactive metabolites by phagocytic cells result in oxidative mammary tissue damage. Increased metabolism of PUFAs, such as arachodonic acid, generates lipid hydroperoxidases that contribute to RM. Oxidative stress occurs when elevated RM overwhelm the anti-oxidant defenses and induces tissue damage.
10.1111/jvim.13793
15-F2t-isoprostanes (15-F2t-Isop) is considered a gold standard biomarker in some human conditions of oxidative stress. What did its evaluation as a biomarker for coliform mastitis in dairy cattle result in?
Free plasma 15‐F2t‐Isop quantified by LC‐MS/MS and total milk 15‐F2t‐Isop quantified by cbELISA are accurate biomarkers of systemic and mammary gland oxidant status, respectively. Free 15‐F2t‐Isop in urine and milk were not predictive of systemic or local mammary gland environment oxidant status, respectively.
10.1111/jvim.13793
What regulates extracellular potassium balance?
Input - from feed intake
Output - renal excretion
These things can be affected by drugs (diuretics, mineralocorticoids)
10.1111/jvim.13842
What regulates intracellular potassium balance?
Driving from IC to EC: acidosis, alpha-adrenergic receptors, cell damage, ischemia, heavy exercise
Driving from EC to IC: alkalosis, insulin, beta-adrenergic receptors, aldosterone
10.1111/jvim.13842
A study was performed to evaluate the potassium homeostasis by comparing the extracellular and intracellular potassium concentration in cows with reduced feed intake and GI ileus. IC K was measured in erythrocytes and muscle tissue. What was the association between IC and plasma [K+]?
There was no association between IC K+ pool and blood [K+]. Erythrocytes were also not a suitable sample material for IC measurement of K+.
10.1111/jvim.13842
How do band neutrophils differ in ability when compared to mature neutrophils?
- Reduced capability to manage infection
- Reduced migration to chemoattractants
- Decreased production of reactive O2 species
- Deceased phagocytic and bacteriocidal activity
10.1111/jvim.13968
What are characteristics of toxic neutrophils?
- Cytoplasmic basophilia
- Cytoplasmic vacuolation
- Dohle bodies
- Toxic granulations
10.1111/jvim.13968
In a study looking at presence of band cells and toxic neutrophils with SIRS and outcome in horses with acute disease, what were the results?
The detection of band neutrophils on admission was assoc. with the SIRS status of the horse and with poor outcome. Simllarly, the presence of a neutrophil toxic grade higher than 3 was assoc. with SIRS and death. The microscopic review of blood smears from critically ill horses to detect band cells or neutrophil toxic change is valuable and could help in assessing disease severity and prognosis in adult equine emergency admissions.
10.1111/jvim.13968
What advantages does SAA have over fibrinogen?
- Low or undetectable values in healthy animals
- Rapid increase after inflammatory event
- Rapid decrease after disease resolution
10.1111/jvim.13978
In foals with bronchopneumonia, was SAA a reliable diagnostic when comparing to healthy foals?
While SAA did increase in those foals with bronchopneumonia, significantly higher, the ability of SAA to predict was limited with a Sn of 64% and Sp of 77%.
10.1111/jvim.13968
