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Introduction: Cardiac diseases can affect the contractile and/or conductive cardiac muscle cells. Recently, the microscopic examination of the subendocardial biopsy is being used in the diagnosis of some cardiac lesions. However, the routine staining cannot differentiate between different types of cardiac fibers. Aim of the work: The present study aims to illustrate the use of anti-cardiac troponin-T3 (cTnT3) immunostaining as a recent tool to distinguish between the contractile and conducting fibers. Materials and Methods: Specimens from both left ventricular wall and interventricular septum were obtained from 6 healthy adult male mice. These specimens were fixed in 4% paraformaldehyde at 4⁰C and processed for paraffin sections. Then, 3 μm thick sections were stained with H&E and anti-cTnT3 antibody and were examined under light microscope. The optical density of the cTnT3 staining affinity of the cardiac fibers was measured morphometrically and the values were statistically analyzed. Results: Examination of H&E stained sections of the left ventricular wall and interventricular septum revealed homogenous staining of all cardiac fibers with an undetectable difference among them. While examination of the immunostained sections with anti-cTnT3 revealed different affinities: the majority of fibers expressed high-positive staining affinity while other fibers had a low or no staining affinity. The high-positive staining affinity was in the form of cytoplasmic transverse dark brownish striations in longitudinally oriented cardiac fibers. The fibers which expressed a low or no staining affinity were either singly scattered especially in the left ventricular wall or grouped in the subendocardial regions of the interventricular septum. Statistically, the optical density values of a low or no staining affinity cardiac fibers were significantly lower (2.5±0.01) than high positive staining affinity cardiac fibers (3.04±0.19). Conclusion: Immunostaining with anti-cTnT3 staining could be added to the routine staining in the examination of cardiac biopsies. [ABSTRACT FROM AUTHOR]

We performed this study to understand the effect of human umbilical cord blood derived mesenchymal stem cells (hUCB-MSCs) on the submandibular gland after bilateral ovariectomy. For this, 21 adult female rats were distributed equally among 3 groups: the sham-operated group (SHAM); the ovariectomized group (OVX); and the OVX group that received repeated intravenous injections of the hUCB-MSCs (OVX + hUCB-MSCs). We used reverse transcription - PCR to analyze for the gene expression of AQPs 3, 4, 5, and BMP-6. The cellular localization and expression of human CD105, human CD34, proliferating nuclear antigen (PCNA), single-stranded DNA (ss-DNA), caspase 3, AQP1, and α smooth muscle actin (α-SMA) were determined immunohistochemically. In the OVX group, a significant decrease in the gene expression of AQP3, AQP4, and BMP6, as well as the acinar area % was detected, while area % of granular convoluted tubules (GCTs) showed a significant increase. A significant decrease in area % staining positively for AQP1 and α-SMA was noted. An obvious improvement in the structure of the submandibular gland was demonstrated in the group injected with hUCB-MSCs, as well as a significant increase in the gene expression of AQP3, AQP4, and BMP6. The acinar and GCT area %, as well as the different measured markers, were relatively normal. This demonstrates that E2-deficiency induces structural changes to the submandibular gland. Moreover, a definite amelioration of the structure and function of the submandibular gland was detected after the administration of hUCB-MSCs. [ABSTRACT FROM AUTHOR]