农业类兽医临床病理(英)课件.ppt

1、Veterinary Clinical Pathology兽医临床病理学Prof.Zhaoxin TangProf.Zhaoxin TangCollege of Veterinary Medicine,South China Agricultural College of Veterinary Medicine,South China Agricultural University,Guangzhou,China,510642University,Guangzhou,China,5106422021/02/241PrefaceVeterinary Clinical Pathology:Vete

2、rinary Laboratory MedicineInclude:1 Clinical Hematology2 Clinical biochemistry3 Clinical cytology4 Clinical microbiology5 Clinical parasitology6 Clinical toxicology2021/02/242PrefaceGeneral Laboratory concepts Veterinarians have many choices regarding laboratory testing.Important factors include:-Ne

3、ed and usefulness-Practicality-Cost-effectiveness-Accuracy-Turnaround time2021/02/243Complete Blood Count and Bone Marrow Examination:general comments and selected techniques Complete blood count Quantitation techniques Blood smear analysis Other determinations Bone marrow examination Bone marrow bi

4、opsy and aspirate2021/02/244Complete blood count(CBC)CBC is a pro tests used to describe the quantity and quality of the cellular elements in blood and a few substances in plasma.CBC is a cost-effective screen the detects many abnormalities and disease conditions.Bone marrow examination is used in s

5、elected instances to answer questions the more readily available CBC cannot.2021/02/245Quantitation Techniques Sample submission Microhemotcrit Hemoglobin concentration Cell counts Absolute nucleated RBC count Automated hematology cell counters2021/02/246Blood Smear Analysis Making the smear Stains

6、Evaluating blood smears -platelet morphology -leukocyte morphology -leukocyte estimation -leukocyte differential count -erythrocyte morphology2021/02/247Bone Marrow Examination Bone marrow is usually examined to answer certain question that arose from evaluating the CBC.Indications for bone marrow e

7、xamination include:-nonregenerative anemia -Persistent neutropenia -Persistent thrombocytopenia -Unexplained polycythemia or thrombocytosis -Atypical cells in blood2021/02/248Erythrocytes Basic concepts of erythrocyte function,metabolism,production and breakdown Heme synthesis Globin synthesis Iron

8、metabolism2021/02/249Erythrocyte metabolism Embden-meyerhof pathway -Glycolysis generates ATP and NADH Pentose phosphate pathway -This pathway produces NADPH Methemoblobin reductase pathway -Methemoglobin(Fe3+)cannot transport oxygen Rapoport-luebering pathway -2,3 diphosphoglycerate(2,3 DPG)2021/02

9、/2410Red blood cells The fundamental stimulus for production of red blood cells(erythropoiesis)is erythropoietin(红细胞生成素）红细胞生成素）,a glycoprotein produced by the kidneys in response to renal tissue hypoxia.Other hormones,such as corticosteroids,thyroid hormone and androgens,stimulate the production or

10、release of erythropoietin but have no intrinsic erythropoietic activity.The average lifespan of a circulating erythrocyte is 110-120 days in the dog and 68 days in the cat.Aged or damaged red cells are removed primarily by macrophages in the liver,spleen and bone marrow.2021/02/2411NeutrophilsThe pr

11、oduction of neutrophils,eosinophils and basophils is termed granulopoiesis.The neutrophils in the bloodstream either circulate freely(the circulating pool)or adhere to the vascular endothelium(the marginal pool).In the dog the marginal pool and the circulating pool are approximately equal in size,wh

12、ilst in the cat the marginal pool is two to three times larger than the circulating pool.There is a continual exchange of cells between these two pools.The half-life of circulating neutrophils is only 6-14 hours,after which time they leave the circulation and pass into the tissue pool.The circulatin

13、g time is shortened during acute infections as neutrophils pass to the site of infection in the tissues.The main function of the neutrophil is the phagocytosis of pyogenic bacteria.2021/02/2412Lymphocytes Lymphoid primitive stem cells divide and differentiate into pre-B lymphocytes and pre-T lymphoc

14、ytes in the bone marrow.Pre-T lymphocytes mature and proliferate into T cells in the thymus.Pre-B cells proliferate in the bone marrow and migrate to peripheral lymphoid organs(spleen and lymph nodes)where further proliferation takes place.Platelets Platelets are produced from the cytoplasm of megak

15、aryocytes Once in the circulation,platelets survive for 8-12 days.Up to 20-30%of circulating platelets can be sequestered in the spleen;the figure may be a high as 90%if there is splenomegaly.Old or damaged platelets are removed from the circulation by the spleen,liver and bone marrow.2021/02/2413RO

16、UTINE HAEMATOLOGYThe complete blood count is an integral part of the diagnostic investigation of any systemic disease process.It consists of two components:A quantitative examination of the cells,including:packed cell volume(PCV)total red cell count(RBC)total white cell count(WBC)differential white

17、cell count platelet count mean corpuscular volume(MCV),mean corpuscular haemoglobin(MCH),mean corpuscular haemoglobin concentration(MCHC),total plasma protein concentration.A qualitative examination of blood smears for changes in cellular morphology.2021/02/2414Table 1 Reference values for red cell

18、indices DogsCatsTotal red blood cells(x1012/L)5.58.55.010.0Haemoglobin(g/dl)12.018.08.015.0PCV(L/L)0.370.550.260.45MCV(fl)60.077.039.055.0MCH(pg)19.524.512.517.5MCHC(g/dl)32.037.030.036.0ROUTINE HAEMATOLOGY2021/02/2415RED BLOOD CELL INDICESMCV(fl飞升飞升)=PCV(L/L)1000/total red cells(1012/L)MCH(pg皮克皮克)=

19、total haemoglobin(g/dl)10/total red blood cells(1012/L)MCHC(g/dl)=total haemoglobin(g/dl)/PCV(L/L)RBC indices are helpful in the classification of certain anemias.ROUTINE HAEMATOLOGY2021/02/2416Differential white cell countsThe differential white cell count is performed by counting 200 leucocytes in

20、 a blood smear.The cells are counted along the long edge of the smear,using the battlement meander method:four high-power fields are counted in one direction,then four more in a direction at right angles to the first,and so on,following the shape of a battlement.The percentage of each type of cell i

21、s determined.This percentage is then multiplied by the total white cell count to obtain an absolute count for each cell type.ROUTINE HAEMATOLOGY2021/02/2417Plasma protein concentration(Reference range:60-80 g/1 for the dog and cat)Total plasma protein(TPP)and PCV should be interpreted together.Quali

22、tative examination of a blood smearA blood smear should always be evaluated when automated cell counts are made or when in-practice instrumentation is limited to a centrifuge for PCV Preparation of a blood smear A small drop of blood is placed on one end of a glass slide,using a capillary tube.A spr

23、eader slide(made by breaking off the comer of another slide,after scoring it with a glass cutter or diamond writer)is placed on to the slide holding the blood drop,in front of the drop and at an angle of 20-40.ROUTINE HAEMATOLOGY2021/02/2418Anaemia is characterized by an absolute decrease in red cel

24、l count,haemoglobin concentration and PCV.Acute haemorrhage may be due to trauma or surgery,bleeding gastrointestinal ulcers or tumours,rupture of a vascular tumour(e.g.splenic haemangiosarcoma),or a coagulopathy(e.g.warfarin toxicity).Immediately following acute haemorrhage the red cell parameters,

25、including PCV,are normal because both red cells and plasma have been lost in proportion.Compensatory mechanisms such as splenic contraction may further offset any fall in PCV.The PCV falls when blood volume is replaced by interstitial fluid and so does not indicate the full magnitude of blood loss f

26、or at least 24 hours after the onset of haemorrhage.ROUTINE HAEMATOLOGY2021/02/2419 Chronic haemorrhageChronic external blood loss(e.g.chronic gastrointestinal haemorrhage,renal or bladder neoplasia)initially results in a regenerative anaemia but gradually the anaemia becomes non-regenerative as the

27、 iron stores become depleted.Young animals become iron-deficient more bone marrow is already very active producing red cells quickly than adults following blood loss,partly because they have low iron stores and partly because their to match their growth rate and so has less capacity to increase its

28、rate of haemopoiesis.Haemolytic anaemiasMost cases of haemolytic anaemia are immune-mediated.In the dog most cases of immune-mediated is haemolytic anaemia(IHA)are primary(idiopathic)and are termed autoimmune haemolytic anaemia(AIHA).IHA may occur in association with:drugs(e.g.potentiated sulphonami

29、des);lymphoreticular diseases(e.g.lymphoid leukaemia);systemic lupus erythematosus;or infections(e.g.Babesia,bacterial endocarditis).ROUTINE HAEMATOLOGY2021/02/2420DISORDERS OF WHITE CELL NUMBERNeutrophiliaFigure 3.20 Causes of neutrophilia Physiological response(fear,excitement,exercise)Stress/cort

30、icosteroid-induced Acute inflammatory response:bacterial infection(localized or generalized),immune-mediated disease,necrosis,e.g.pancreatitis,neoplasia,especially with tumor necrosis.Chronic granulocytic leukaemia Neutrophil dysfunction Paraneoplastic syndromes 2021/02/2421Neutropenia The three mai

31、n causes of neutropenia are:An overwhelming demand for neutrophils Reduced production of neutrophils in the bone marrow Defective neutrophil maturation in the bone marrow.An overwhelming demand for neutrophils may occur with peracute bacterial infections,especially Gram-negative sepsis and endotoxae

32、mia.Other possible causes include peritonitis,pyometra（子宫蓄脓）（子宫蓄脓）,aspiration pneumonia and canine parvovirus infection.DISORDERS OF WHITE CELL NUMBER2021/02/2422 Eosinophils are distributed in the body among various pools in a similar way to neutrophils,although the bone marrow storage pool is mini

33、mal.Eosinophils circulate in the bloodstream for only a few hours before entering the tissues,where they may live for several days.Their two main functions are to kill parasites and to regulate allergic and inflammatory reactions.Eosinopenia in combination with lymphopenia occurs following stress,ad

34、ministration of corticosteroids and in spontaneous hyperadrenocorticism(Cushings syndrome).Basophils contain inflammatory mediators such as histamine and heparin and function in a similar manner to mast cells in hypersensitivity reactions.DISORDERS OF WHITE CELL NUMBER2021/02/2423Causes of lymphocyt

35、osis 1.Physiological lymphocytosis,with concomitant neutrophilia,in response to excitement(especially cats)2.Strong immune stimulation(e.g.in chronic infection,viraemia or immune-mediated disease)3.Chronic lymphocytic leukaemia 4.Hypoadrenocortiscism(lymphocytosis may be associated with an eosinophi

36、lia)5.Increased numbers of large reactive lymphocytes may occur transiently following vaccination 6.Young animals have a higher lymphocyte count than adult animalsDISORDERS OF WHITE CELL NUMBER2021/02/2424StressGlucocorticoid therapyHyperadrenocorticismChylothorax(loss of lymphocytes into the pleura

37、l space)Lymphangiectasia(loss of lymphocytes into the gut)Acute phase of most viral infections(e.g.canine distemper,parvovirus,FeLV)Septicaemia/endotoxaemiaDISORDERS OF WHITE CELL NUMBER2021/02/2425DogsCats percentageAbsolute valuepercentageAbsolute value(10/Total WBCN/a617N/a5.519.5Band neutropils0

38、300.30300.3Neutropils6077311.535372.512.5Lymphocytes123014.820551.57Monocytes3100.21.51401.5Eosinopils2100.11.321201.5basopilsrarerarerareRareReference ranges for total and differential white blood cell counts2021/02/2426Table 2 shows the alterations in some of parameters in various diseases.Laborat

39、ory assessmentTests to assess primary haemostasis include:Platelet count Bleeding time Clot retraction.Tests to assess secondary haemostasis include:Whole blood clotting time(WBCT)Activated clotting time(ACT)Activated partial thromboplastin time(APPT)One-stage prothrombin time(OSPT)Thrombin time(TT)

40、DISORDERS OF WHITE CELL NUMBER2021/02/2427Disseminated intravascular coagulation(DIC):This may be triggered by a wide variety of diseases,including endotoxaemia neoplasia(especially haemangiosarcoma 血管肉瘤血管肉瘤)acute infections(e.g.infectious canine hepatitis)haemolytic anaemia pancreatitis heat stroke

41、.The clinicopathological features of DIC are:Thrombocytopenia Increased OSPT/APTT Elevated FDPs Low fibrinogen Schistocytes in the blood film.DISORDERS OF WHITE CELL NUMBER2021/02/2428兽医临床病理学兽医临床病理学College of Veterinary Medicine,SCAU,Guangzhou,China 5106422021/02/2429Clinical biochemistryIntroductio

42、n Serum proteins Total protein and albumin Globulins Indicators of renal function Urea nitrogen Creatinine Markers of hepatic disease Alanine aminotransferase Aspartate aminotransferase Alkaline phosphatase Gamma-glutamyi transferase Bilirubin Bile acids Ammonia Pancreatic disease Amylase LipaseElec

43、trolytes Sodium;Potassium;Chloride Magnesium;Calcium;Phosphorus Muscle enzymes Creatine kinaseAspartate aminotransferase Carbohydrate metabolism GlucoseFructosamine Lipid metabolism CholesterolTriglycerides Miscellaneous tests Iron Lead ZincCopper Chemical profiles and test selection 2021/02/2430SER

44、UM PROTEINS Physiology The circulating proteins are synthesized predominantly in the liver,although plasma cells also contribute to their production.Quantitatively the single most important protein is albumin(35-50%of the total serum protein concentration).The other proteins are collectively known a

45、s globulins.The functions of proteins are many and varied but include maintenance of plasma osmotic pressure,transport of substances around the body(e.g.ferritin铁蛋白铁蛋白,ceruloplasmin血浆血浆铜蓝蛋白铜蓝蛋白),humoral immunity,buffering and enzyme regulation.Indications for assay The measurement of proteins is gen

46、erally included in an initial health screen in all patients but especially where intestinal,renal or hepatic disease or haemorrhage is suspected.Analysis Protein concentrations can be estimated in serum,plasma,urine or body fluids with a refractometer or by spectrophotometry.Serum albumin levels are

47、 measured by bromocresol green dye溴甲酚绿溴甲酚绿 binding and the serum globulin is calculated by subtraction of the albumin concentration from the total protein concentration.2021/02/2431Reference ranges Neonates and very young animals have lower concentrations of albumin and globulins(due to minimal quan

48、tities of immunoglobulins).As the animal gains immunocompetence the protein concentrations rise to reach adult values.Physiological decreases in albumin may be noted during pregnancy.Critical values Marked hypoalbuminaemia(1.030 in dogs,1.035 in cats)supports the diagnosis of a prerenal azotaemia.IN

49、DICATORS OF RENAL FUNCTION2021/02/2439PhysiologyCreatinine is formed from creatine in the muscles in an irreversible reaction.The quantity of creatinine produced depends upon diet(small contribution)and the muscle mass.Disease affecting the muscle mass may affect the daily creatinine production.Both

50、 urea and creatinine are freely filtered at the renal glomerulus but urea is subject to tubular reabsorption and thus creatinine is said to be a better indicator of GFR.Analysis Creatinine can be measured in serum,plasma or abdominal fluid by spectrophotometric methods.Reference ranges Dogs 20-110 u