Ultrahigh-field cardiovascular magnetic resonance T1 and T2 mapping for the assessment of anthracycline-induced cardiotoxicity in rat models: validation against histopathologic changes

Background Chemotherapy-induced cardiotoxicity is a well-recognized adverse effect of chemotherapy. Quantitative T1-mapping cardiovascular magnetic resonance (CMR) is useful for detecting subclinical myocardial changes in anthracycline-induced cardiotoxicity. The aim of the present study was to histopathologically validate the T1 and T2 mapping parameters for the evaluation of diffuse myocardial changes in rat models of cardiotoxicity. Methods Rat models of cardiotoxicity were generated by injecting rats with doxorubicin (1 mg/kg, twice a week). CMR was performed with a 9.4 T ultrahigh-field scanner using cine, pre-T1, post-T1 and T2 mapping sequences to evaluate the left ventricular ejection fraction (LVEF), native T1, T2, and extracellular volume fraction (ECV). Histopathological examinations were performed and the association of histopathological changes with CMR parameters was assessed. Results Five control rats and 36 doxorubicin-treated rats were included and classified into treatment periods. In the doxorubicin-treated rats, the LVEF significantly decreased after 12 weeks of treatment (control vs. 12-week treated: 73 ± 4% vs. 59 ± 9%, P = 0.01). Increased native T1 and ECV were observed after 6 weeks of treatment (control vs. 6-week treated: 1148 ± 58 ms, 14.3 ± 1% vs. 1320 ± 56 ms, 20.3 ± 3%; P = 0.005, < 0.05, respectively). T2 values also increased by six weeks of treatment (control vs. 6-week treated: 16.3 ± 2 ms vs. 10.3 ± 1 ms, P < 0.05). The main histopathological features were myocardial injury, interstitial fibrosis, inflammation, and edema. The mean vacuolar change (%), fibrosis (%), and inflammation score were significantly higher in 6-week treated rats than in the controls (P = 0.03, 0.03, 0.02, respectively). In the univariable analysis, vacuolar change showed the highest correlation with native T1 value (R = 0.60, P < 0.001), and fibrosis showed the highest correlation with ECV value (R = 0.78, P < 0.001). In the multiple linear regression analysis model, vacuolar change was a significant factor for change in native T1 (P = 0.01), and vacuolar change and fibrosis were significant factors for change in ECV (P = 0.006, P < 0.001, respectively) by adding other histopathological parameters (i.e., inflammation and edema scores) Conclusions Quantitative T1 and T2 mapping CMR is a useful non-invasive tool reflecting subclinical histopathological changes in anthracycline-induced cardiotoxicity.

Toxic leukoencephalopathy caused by chemotherapeutic drugs other than methotrexate

Background & Objective Chemotherapy-induced toxic leukoencephalopathy is clinically characterized by progressive cognitive loss, often resulting in sudden death. The objective of this study is to share distinctive clinicopathological features of chemotherapy-induced brain change.Methods The brains of a 64-year-old woman and a 63-year-old man who suffered from rapid deterioration of consciousness were autopsied. The initial clinical impressions were central nervous system (CNS) graft versus host disease (GVHD), infectious or autoimmune encephalitis. Both patients had been treated with multidrug chemotherapy, including cytarabine arabinoside, daunorubicin, fludarabine, azacitidine, and busulfan, and allogeneic peripheral blood stem cell transplantation because of hematological malignancy (acute myelogenous leukemia and myelodysplastic syndrome). Results The autopsies revealed a vacuolar change of the white matter with axonal spheroids, reactive gliosis, and foamy macrophage infiltration in the brain, predominantly in the visual pathway of the occipital and temporal lobes. There was no lymphocytic infiltration in the brain tissue, which is characteristic of CNS-GVHD or encephalitis, suggesting these syndromes were not the cause of brain illness. Conclusion The leukoencephalopathy found in our cases is often occur after methotrexate treatment, but our autopsy cases showed that it can also be caused by a regimen of chemotherapeutic drugs other than methotrexate.

Age-Related Arteriolar Changes With Lipid and Amyloid Deposits in the Gonads of Dogs

Arteriolar lesions with lipid and/or amyloid deposits are frequently detected in canine gonads by routine histopathologic examination; however, they have never been examined in detail. In the present study, a total of 139 testes/epididymides and 200 ovaries from 72 male (4 months to 14 years old) and 105 female (7 months to 16 years old) dogs were examined for arteriolar lesions. Arteriolar lesions were detected in 21 of 72 male dogs (29%) and 54 of 105 female dogs (51%). These lesions were histologically classified into 4 types: “fibromuscular hypertrophy,” characterized by thickening of the tunica intima; “focal vasculitis,” characterized by mononuclear cell infiltration; “vacuolar change,” consisting of lipid accumulation and infiltration of foamy cells; and “hyalinosis,” characterized by irregular thickening with amyloid deposits. In the lesions of vacuolar change and hyalinosis, lipid deposition and infiltration of α-SMA-positive cells and Iba-1-positive cells were also observed. Foamy cells and amyloid deposits were immunopositive for apolipoproteins and oxidized low-density lipoprotein-related proteins. These results indicate that vacuolar change is possibly an early stage of atherosclerosis, and that amyloid may deposit as a consequence of the microenvironment associated with atherogenesis. Logistic regression analysis revealed that arteriolar lesions with lipid deposits were associated with age and interstitial cell tumors in male dogs, and with age in female dogs. Aging is likely an important risk factor of arteriolar lesions with lipid deposits of the canine gonads.

EVALUATION OF PROTECTIVE POTENTIAL OF CITRUS AURANTIFOLIA (CHRISTM) SWINGLE PEEL EXTRACT IN ATTENUATING DOXORUBICIN-INDUCED HEPATOTOXICITY IN EXPERIMENTAL MODELS

Citrus aurantifolia is a very common, and widely cultivated and consumed for its antioxidant properties due to its robust flavonoids content. Doxorubicin (DOX) is an antibiotic broadly used in the treatment of different types of solid tumours, but its use also comes at a cost, organ toxicity. The curative and preventive properties of Citrus aurantifolia peel extract (CAPE) in doxorubicininduced hepatotoxicity in Wistar rats were evaluated. Thirty female rats were divided into six groups of five (5) rats each in both curative and preventive studies. In curative study, five groups of rats (II – VI) received Doxorubicin (mixed with normal saline, 15 mg/kg body weight i.p) on day one, 24 hours after, graded doses of CAPE and alpha-lipoic acid (A.L.A.) were administered to groups II- V and VI respectively for 7 consecutive days. For the prophylactic study, groups II – V and VI received graded doses of CAPE and A.L.A. respectively, 24 hours after Doxorubicin was administered to groups II-VI. Groups treated with D.W. and A.L.A. were used as a negative and positive control, respectively Liver enzymes such as A.S.T., A.L.T. and A.L.P., including liver samples, were examined for histopathological changes. A significant reduction (p< 0.05) in serum A.S.T. and A.L.T. levels was observed in animals treated with CAPE 200 and 400mg/kg in the preventive study, while in curative, a significant reduction in an expected rise in serum A.S.T., A.L.T. and A.L.P. (p<0.05) was observed in animals treated with CAPE 400mg/kg when compared to the group treated with DOX + distilled water. Hepatocellular necrosis was observed in the histology of DOX- distilled water treated group. Besides, the hepatocytes of groups treated with CAPE (200 and 400mg/kg) in this study showed narrow foci of mild vacuolar change as compared with groups treated with the lowest dose of CAPE (100mg.kg) and distilled water, which revealed random foci of mild vacuolar change. This study has provided information that DOX damaged liver tissue due to an increase in liver enzymes and histopathological results showing tissue damaged in groups treated with lower doses of CAPE and distilled water. This study further demonstrates that groups treated with CAPE 200, 400 mg/kg and A.L.A. protect hepatic damage induced by DOX.

Involvement of Annexin A2 Expression and Apoptosis in Reverse Polarization of Invasive Micropapillary Carcinoma of the Breast

Invasive micropapillary carcinoma (IMPC) is characterized by pseudopapillary tumor-cell clusters with a reverse polarity (RP) floating in lacunar spaces, with aggressive biological characteristics. The RP prevention is considered to inhibit IMPC, but its pathogenic mechanisms remain unclear. Annexin A2 (ANX A2), a cell-polarity protein, is known to be involved in lumenogenesis. ANX A2 expression is immunohistochemically examined, as well as both epithelial membrane antigen (EMA) and mucin-1 glycoprotein (MUC-1), the gold-standard markers for luminal differentiation, in the background tumor components of a case of IMPC. The following findings were noticed: (1) Apoptosis was scattered with peripheral apoptotic vacuolar change; (2) EMA and MUC-1 expressions were found, rimming the peripheral apoptotic vacuoles (including the contact surface with neighboring tumor cells), and these positions corresponded to the ones with a distinct ANX A2 positivity; and (3) partially detached tumor cells showed distinct positivity of three proteins at the stroma-facing surface, which is consistent with a RP. Taken together, frequent apoptosis in tumor cells with membranous accumulation of ANX A2 is considered to be indispensable for the reverse polarization of IMPC, and that secondary necrosis following apoptosis induces the cell-polarity disorder and creates detached tumor cells with a RP.

Accuracy of US-Guided FNA of Focal Liver Lesions in Dogs: 140 Cases (2005–2008)

Medical records from dogs having abdominal ultrasound (US) performed between March 2005 and October 2008 were reviewed for detection of focal liver lesions (FLL) with both cytologic and histologic sampling. Samples were classified as to either the presence or absence of major categories of pathologic processes, including malignant neoplasia, inflammation, hyperplasia/benign neoplasia, vacuolar change, extramedullary hematopoeisis, cholestasis, necrosis, and no microscopic abnormalities. Evaluation of selection bias was performed by review of the relative distribution of cytologic diagnoses for cases with histology compared with cases excluded from the comparison analysis because histology results were not available. Cytology had the highest sensitivity for vacuolar change (57.9%), followed by neoplasia (52.0%). Cytology had the highest positive predictive value (PPV) for neoplasia (86.7%) followed by vacuolar change (51.6%). Cytology had lower sensitivity and PPVs for inflammation, necrosis, and hyperplasia. The ability of cytology to characterize disease in canine FLL varies by pathologic process. Clinicians can have a high degree of confidence when a cytologic diagnosis of neoplasia is given; however, cytology is less reliable for excluding the potential for neoplasia. Cytology has a low sensitivity and PPV for inflammation and a limited diagnostic performance for the diagnosis of vacuolar change.

Vacuolation in Renal Tubular Epithelium of Mice: an Incidental Lesion

Prominent cytoplasmic vacuoles in renal tubular epithelial cells of the outer medulla were observed in several kidneys from test article-dosed mice during routine light microscopic (LM) examination. Because the vacuolar change was seen infrequently by LM examination, and was not found in any control mice from that study, it was not clear whether the vacuolation represented a drug-induced change. To address this question, kidney sections from multiple unrelated mouse studies (214 control mice and 541 test article-dosed mice representing six different compounds) were examined by LM for similar vacuolar changes. Vacuolation was seen by LM in 2.3% of the control and 2.8% of the test article-dosed mice. Transmission electron microscopy (TEM) was performed on kidneys with prominent vacuoles seen by LM in 5 control mice and 2 test article-dosed mice to further characterize the vacuoles. Additionally, kidneys from 4 randomly selected control mice lacking vacuolation by LM were examined by TEM. Samples from the outer medulla of kidney that had been fixed by immersion in 10% formalin were post-fixed in 2.5% glutaraldehyde and 2% osmium tetroxide and processed routinely for TEM.