Management of Patients AB 18% Flashcards
Which interleukins send anorexigenic and orexigenic signals?
IL1 & IL6 - contribute to cancer cachexia
Define cancer cachexia.
profound destructive process characterized by skeletal m wasting with or w/o loss of fat mass and harmful abnormalities in fat and CHO metabolism in spite of adequate intake
Pathways involved in cancer cachexia
NF-kb –> ubiquitin proteasome pathway
TNFa up regulates myostatin (TGFb) that negatively regulates muscle mass
TNFa also interferes with anabolic effects of GH and IGF1
Cell autophagy/lysosomal and Ca2+-dependent protein degradation pathways, ER stress and mitochondrial dysfunction are involved in muscle protein degradation in cancer cachexia
Most common cause of paraneoplastic GI ulceration?
MCT with histamine the main driver
Tx for GI ulceration?
H2 blockers, PPIs, misoprostol, sucralfate, rehydration
prophylactically rec for advanced stage disease
Tumors associated with hypercalcemia in dog? Cat? (in order of commonality)
Dog - LSA (35-55%), AGASACA (25%), MM, parathyroid, thymoma, melanoma, mammary tumors, multiple others
Cat- LSA, SCC, MM, others
Tumors associated with hypoglycemia in order of commonality?
insulinoma, HCC, leiomyosarcoma/oma, HSA, LSA, lymphocytic leukemia, mammary carcinoma, melanoma, plasma cell, renal adenocarcinoma, salivary adenocarcinoma
Tumors associated with hyperestrongenism in order of commonality?
Sertoli cell, seminoma, interstitial cell, granulosa cell
Cause of acromegaly?
pituitary tumor (cat)
Which tumor has been associated with paraneoplastic ectopic ACTH release?
primary lung tumors
Most common cause of hyperglobulinemia?
MM
What else can cause a monoclonal gammopathy?
other than cancer
Leishmania, Erhlichia
Most common cause of hypercalcemia in cats (non-neoplastic v. LSA and myeloma)?
Options were: neoplasia 33%, idiopathic not listed
- Idiopathic 42%, CKD 35%, neoplasia 13% (LSA most common neoplasia, SCC second most)
- Confusing b/c Withrow – 1/3 (30%) cats w hypercalcemia was from malignancy
Tumors associated with pareneoplastic anemia? Thrombocytopenia?
LSA, leukemias, HSA, others
same for PLT and hct
Paraneoplastic erythrocytosis?
renal tumors, nasal fibrosarcoma, laeiomyosarcoma, schwannoma, tvt
Paraneoplastic neutrophilic leukocytosis caused by wat cancers?
lung tumors, LSA
Thrombocytopenia in tumor-bearing dogs typically secondary to?
- Chemotherapy
- As high as 36% in tumor-bearing dogs
- 58% in dogs w lymphoid neoplasia
- Also common in vascular splenic tumors
% of cats with thrombocytopenia that is cancer related?
39% - LSA most common
Mechanisms of cancer related thrombocytopenia?
- Platelet destruction
- Sequestration
- Consumption
- Decreased production
Tumors associated with DIC?
- HSA
- inflammatory mammary carcinoma
- pulmonary carcinoma
Nodular dermatofibrosis associated tumor?
renal cystadenoma/carcinoma
Which tumor causes superficial necrolytic dermatitis?
glucagonoma
Tumors associated with feline paraneoplastic alopecia?
pancreatic carcinoma, biliary carcinoma
Which tumor can cause exfoliative dermatitis in a cat?
thymoma
Tumors associated with glomerulonephritis?
primary erythrocytosis, lymphocytic leukemia
Which tumor is most likely to cause myasthenia gravis? Others?
thymoma
- OSA, biliary carcinoma, LSA, oral sarcoma
Tumors commonly associated with peripheral neuropathy?
insulinoma, lung tumors, mammary tumors
Most common cause of HO?
pulmonary metastasis from OSA > primary lung tumor
urinary tract tumors, esophageal tumors
Blood work for primary hyperparathyroidism? Most common cause?
- High iCa, normal or high PTH
- functional benign parathyroid adenoma or adenomatous hyperplasia
Case presented had increased TCa, increased Crea, N phos, N PTH, USG 1.011 =
inconclusive - either primary hyperparathyroidism or hypercalcemia of malignancy need more info
HARD IONS
Mechanism of hypercalcemia in osteolytic lesions (e.g. MM)?
TNF, IL-1, 6, calcitriol
Paracrine factors that increase osteoclast # and activity in bony metastasis?
IL1, 6, TNFa/b, RANKL
Most common CS of hyperCa in Dogs? Cats?
Dog - PU/PD d/t impaired action of ADH on renal tubular cells of collecting duct
Cat - anorexia, vomiting
Blood work for hypercalcemia of malignancy?
- low PTH, high OR normal PTHrp
- calcitriol is expected to be normal but can be high or low
When to tx hyperCa of malignancy?
- Always removal of cause or chemo induction if possible
- tCa > 16 mg/dL x phosphate (mg/dL) product > 60
- if p is ill or azotemia
- if p will not respond to sx or chemo
Fluid choice for hyperCa of malignancy? Why?
0.9% NaCl - competes with Ca for renal tubular absorption further enhancing calciuresis
TX mild hyperCa with minimal CS?
0.9% NaCl rehydration SQ or IV
Moderate to severe hyperCa tx?
- 0.9% NaCl over 4-6 hours rehydration then at 100-125 mg/kg/d (1.5-2x maintenance)
- Lasix 2-4 mg/kg q 8-12 IV, SC, PO ONLY IF HYDRATED
- Prednisone 1-2 mg/kg q12-24h PO if diagnosis made
- Pamidronate 1-2 mg/kg in 250 mL of NaCl IV over 2 hours
or - Zoledronate 0.1-0.25 mg/kg diluted in 60 mL of NaCl IV over 15 mins
Which bisphosphanate is less nephrotoxic, zoledronate or pamidronate?
zoledronate though more (100x) more potent
Aminobisphosphonates bine strongly to hydroxyapatite at which site?
R1
- R2 determines amino-BP (ex.zol) vs nonamino-BP (ex. clodronate)
MOA of zoledronate?
- Mevalonate pathway –> inhibit farnesyl pyrophosphate
- interfere with post translational prenylation of GTP-binding proteins (Ras, Rho, and Rac)
- inhibit bone resorption w/o inhibiting mineralization
- induction of apoptosis net attenuation of pathologic bone resorption
- synthetic analogs of inorganic pyrophosphates with preferential absorption at sites of active remodeling
Most common mechanism of hypoglycemia in non-islet cell (insulin secreting) tumors?
IGF-2 secretion
- others: IGF-1 or somatomedins, hypermetabolism of glucose, production of substances stimulating insulin release, production of hepatic glucose inhibitor, insulin binding by monoclonal immunoglobulin, insulin receptor proliferation, ectopic insulin production
What is the MOA of hypoglycemia associated with plasma cell tumors?
insulin binding by monoclonal immunoglobulin
% of dogs with Sertoli cell tumors with hyperestrogenism?
25-50% - TX by removing tumor
TX for hypoglycemia?
- Oral karosyrup–0.5-1.0ml/kg
- 50%dextrose–1ml/kgIV; Maintain with 2.5-5.0% dextrose CRI
- Small frequent meals
- Treat underlying disease
- Low dose glucocorticoids (0.5mg/kg SID)
- Diazoxide, octreotide
MOA of steroids for hypoglycemia?
- Increases gluconeogenesis
- Decreases peripheral tissue glucose utilization
MOA diazoxide?
- Inhibits insulin secretion
- Increases epinephrine release –-> inhibits glucose uptake by cells
MOA octreotide?
Somatostatin analogue that inhibits release of insulin
TX for ectopic ACTH secreting lung tumor?
- remove if possible
- Trilostane
In MM the M component is most likely to cause monoclonal gammopathy. How does the M component interfere with coagulation?
- coats PLT inhibiting aggregation to damaged endothelial surfaces
- release of PLT factor 3
Affects of Bence Jones proteinuria?
light chain tubular casts–> interstitial nephritis and renal failure
Causes of hyper viscosity syndrome?
monoclonal gammopathy, polycythemia vera, paraneoplastic erythrocytosis
Why is IgM macroglobulinemia most likely to cause hyper viscosity?
high molecular weight pentamer
- in MM the M component is more commonly IgA (dimer) than IgG (monomer); IgA will polymerize
TX for hyper viscosity syndrome?
- plasmapheresis if d/t serum proteins
- phlebotomy and IV fluids if d/t erythrocytosis