Automated Nuclear Morphometry: A Deep Learning Approach for Prognostication in Canine Pulmonary Carcinoma to Enhance Reproducibility.

The integration of deep learning-based tools into diagnostic workflows is increasingly prevalent due to their efficiency and reproducibility in various settings. We investigated the utility of automated nuclear morphometry for assessing nuclear pleomorphism (NP), a criterion of malignancy in the current grading system in canine pulmonary carcinoma (cPC), and its prognostic implications. We developed a deep learning-based algorithm for evaluating NP (variation in size, i.e., anisokaryosis and/or shape) using a segmentation model. Its performance was evaluated on 46 cPC cases with comprehensive follow-up data regarding its accuracy in nuclear segmentation and its prognostic ability. Its assessment of NP was compared to manual morphometry and established prognostic tests (pathologists' NP estimates (n = 11), mitotic count, histological grading, and TNM-stage). The standard deviation (SD) of the nuclear area, indicative of anisokaryosis, exhibited good discriminatory ability for tumor-specific survival, with an area under the curve (AUC) of 0.80 and a hazard ratio (HR) of 3.38. The algorithm achieved values comparable to manual morphometry. In contrast, the pathologists' estimates of anisokaryosis resulted in HR values ranging from 0.86 to 34.8, with slight inter-observer reproducibility (k = 0.204). Other conventional tests had no significant prognostic value in our study cohort. Fully automated morphometry promises a time-efficient and reproducible assessment of NP with a high prognostic value. Further refinement of the algorithm, particularly to address undersegmentation, and application to a larger study population are required.

Alternative Lengthening of Telomeres Is Rare in Canine Histiocytic Sarcoma.

Cancer cells activate telomere maintenance mechanisms (TMMs) to overcome senescence and thus are targets for TMM-specific therapies. Telomerase-independent alternative lengthening of telomeres (ALT) is frequently utilized as a TMM in human sarcoma subtypes. Histiocytic sarcoma (HS) is a rare but aggressive tumor of hematopoietic origin with unknown ALT incidence in humans. ALT has been identified in canine HS, a tumor type comparable to human HS that occurs with high rates in certain canine breeds such as Bernese mountain dogs (BMDs). This retrospective study characterized the frequency of ALT in BMD and non-BMD patients diagnosed with HS as surrogates for humans. Formalin-fixed paraffin-embedded tumor samples from 63 dogs at two centers, including 47 BMDs, were evaluated for their ALT activity and relative telomere content (TC) using a radiolabel C-circle assay (CCA). Known ALT-positive samples served as controls. CCA-positive cases were validated via FISH. Two BMD samples showed ALT activity of 1-14% compared to controls. All other samples were ALT-negative. The TC did not correlate with the CCA results. ALT positivity was validated by the appearance of ultrabright telomere foci. Low ALT activity was present in 4% of BMDs with HS and therefore does not appear to be a common target for therapeutic approaches but can have diagnostic value.

Successful Insulin Glargine Treatment in Two Pet Guinea Pigs with Suspected Type 1 Diabetes Mellitus.

Scientific information on spontaneous type I diabetes mellitus (DM) and treatment modalities in guinea pigs is scarce. As most diabetic guinea pigs are overweight and respond to dietary changes, a disorder resembling type II-DM in humans seems to be most prevalent in this species. In the present report, a nine-month-old female intact guinea pig (GP1) was presented because of a cataract and polyphagia. The physical examinations in GP1 and its littermate, GP2, were unremarkable. Laboratory tests revealed hyperglycemia, hyperlipidemia, elevated fructosamine concentrations, and glucosuria in GP1 and GP2. Not responding to dietary changes, an insulin-dependent diabetes mellitus was suspected in both animals. Treatment with 0.5 IU of glargine insulin (Lantus®) per guinea pig subcutaneously (s.c.) once daily was initiated in both animals. Monitoring included repeated clinical evaluations and the measurement of plasma glucose and fructosamine concentrations. Capillary glucose concentration was measured using a glucometer, and glucosuria was monitored by dipstick. Blood glucose concentrations decreased quickly in both GPs, and glucosuria resolved. Including several dose adjustments, DM remained controlled for over 1.5 years. Bilateral cataracts and lens-induced uveitis in GP1 were medically managed with only slight progression. This is the first report of guinea pigs with insulin-dependent diabetes mellitus that were successfully treated with long-acting basal insulin glargine.

Prevalence and potentially prognostic value of C-circles associated with alternative lengthening of telomeres in canine appendicular osteosarcoma.

Alternative lengthening of telomeres (ALT) is a telomerase-independent telomere maintenance mechanism (TMM) with high prevalence in human osteosarcomas but remains unknown in canine osteosarcomas. The aim of this study was to evaluate the prevalence of ALT by detection of extra-chromosomal circles of telomeric DNA and to assess clinical outcome in canine patients with spontaneous occurring appendicular osteosarcoma. Fifty dogs with histopathological confirmed osteosarcomas were included into this study. Medical records were retrospectively analysed for patient characteristics, oncologic therapy and survival. DNA was isolated from archived FFPE tumour tissue specimens and applied for C- and G-circle assay (CCA and GCA) and for telomeric content (TC) measurement with radiolabeled probes. ALT activity was detected for 10 of 50 (20%) cases by CCA. Four CCA positive cases were detected even with input DNA below 1 ng and demonstrated the high sensitivity of CCA for canine tumours. G-circles and TC were not suitable to distinguish CCA positive and negative cases. CCA-status showed an association with male gender and Rottweiler breed. Dogs with CCA positive osteosarcomas had shorter overall survival times than patients with CCA-tumours and CCA-status was a significant prognostic factor besides treatment in the Cox proportional hazard model. These findings make canine osteosarcomas an interesting model for comparative TMM research, but future studies are warranted to investigate if CCA-status can serve as novel prognostic marker.

Remission of diabetes mellitus after ovariohysterectomy in a guinea pig with ovarian cysts.

A 3-year-old intact female guinea pig was presented with a history of polydipsia, polyphagia, and hyperactivity combined with non-pruritic hair loss. The physical examination revealed bilateral alopecia mainly including the flanks and the ventral abdomen. Bilateral rounded masses just caudal to the kidneys were detected on abdominal palpation. Abdominal ultrasound examination confirmed bilateral ovarian cysts and an enlarged uterus with cystic lesions. Blood biochemistry revealed highly increased glucose and fructosamine concentrations. The final diagnoses were diabetes mellitus, bilateral ovarian cysts, and pathologic changes of the uterus. The guinea pig underwent ovariohysterectomy. After surgery, diabetes mellitus and all of the existing clinical signs were fully resolved. A causal relationship between hormonally active ovarian cysts and diabetes mellitus that commonly present independently from each other in the guinea pig can be strongly assumed in the present case. In suspicious cases of gestagen-induced diabetes mellitus ovariohysterectomy could be considered a potential treatment option in guinea pigs.

Impact of extended working periods on genomic and telomeric DNA and on inflammatory markers: Results of an intervention study with office workers and carpenters.

Aim of this study was to clarify if extension of the work phase has an impact on DNA- stability, telomere lengths and inflammatory markers. We conducted an intervention trial with office workers (n = 24) and carpenters (n = 10), who changed their working schedule from 8 to 12 h per day over a period of 3 months. The work of both groups involved only moderate physical activity. We found no evidence for induction of double strand breaks (measured in γH2AX assays) and relative telomere lengths (relTL_36B4 and ALB) in lymphocytes in the two study groups. Furthermore, no overall changes of the levels of C-reactive protein (CRP), interleukin-6 (IL-6) and thiobarbituric acid reactive substances (TBARS) in plasma were detected. However, we found in agreement with earlier investigations a moderate (not significant) increase of the CRP levels with age. Furthermore, significant higher CRP concentrations (P = 0.03) were detected in young individuals (21-30 years) as a consequence of the extended working period. Taken together our findings indicate that prolongation of the working hours has no pronounced impact on DNA stability, telomere shortening and inflammatory markers; but the increase of the CRP concentrations in young workers may be indicative for adverse health effects in this subgroup.