The study and application of testis tissue xenografting

Testis tissue xenografting (TTX) provides a novel in vivo model for the study of testis function, and a previously-unavailable opportunity to produce spermatozoa in the grafts from immature donors of diverse species. The overall objectives of this thesis were to examine a number of factors that potentially affect the outcome of TTX, and to apply TTX using immature bison and deer donors as models for endangered ungulates. The objective of the first experiment was to examine the effects of recipient mouse strain, gender and gonadal status on the outcome of TTX. Eight small fragments of neonatal porcine testis tissue (~5 mg each) were grafted under the back skin of immunodeficient mice of different strains (SCID vs. nude), gender (male vs. female), and gonadal status (intact vs. gonadectomised), using a 2×2×2 factorial design (8 groups, n = 7 mice/group). The xenografts were recovered at 8 mo post-grafting and evaluated for gross and histological attributes. Gonadectomy of the recipients did not affect any of the measured outcomes of TTX (P > 0.05), and data were pooled into four groups based on recipient strain and gender. Overall, male recipient mice had grafts with higher mean (+SEM) recovery rate (97 ± 2.3% vs. 88 ± 2.4%, P = 0.004), weight (348 ± 26.3 vs. 104 ± 27.0 mg, P < 0.001), seminiferous tubular diameter (150 ± 3.3 vs. 108 ± 5.3 mg, P < 0.001), percentage of tubules containing spermatozoa (32 ± 3.2 vs. 6 ± 1.8%, P < 0.001), elongated spermatids (13 ± 1.4% vs. 4 ± 0.8%, P < 0.001), and round spermatids (10 ± 1.2% vs. 6 ± 1.1%, P = 0.006) than female mice. Overall, SCID mice had grafts with higher recovery rate (98 ± 2.4% vs. 87 ± 2.3%, P = 0.001), average weight (292 ± 27.0 vs. 160 ± 26.3 mg, P = 0.001), tubular density (44 ± 3.3 vs. 33 ± 2.1, P = 0.02), percentage of tubular cross-sections containing spermatocytes (27 ± 3.7% vs. 13 ± 2.3%, P = 0.003) than nude mice. Among the four groups of recipients, the grafts from male SCID mice had the highest weight (P < 0.05) and percentage of tubules containing spermatozoa (P < 0.05). The objective of the second experiment was to evaluate the effect of using different numbers of donor testis tissue fragments on the outcome of TTX. Fragments of donor piglet testis tissue were grafted subcutaneously under the back skin of four groups of castrated male nude mice (n = 10/group). Each group of recipient mice received 2, 4, 8, or 16 fragments per mouse. Mice were sacrificed at 8 mo post-grafting, and xenografts were evaluated for physical growth and histological development. The relative weight of the vesicular gland (index) was also determined as a measure of bioactive androgen production by grafts in castrated recipient mice. The overall graft recovery rate was ~94% (range 86-98%) which did not differ among the groups (P > 0.05). The group of mice that received 16 testis tissue fragments had higher mean (+ SEM) graft weights (278 ± 39.4 vs. 106 ± 38.0, P = 0.02), total graft weight (2,443 ± 338.8 vs. 192 ± 76.2, P < 0.001), vesicular gland index (0.5 ± 0.06 vs. 0.1 ± 0.06, P = 0.007), and percentage of seminiferous tubules with round spermatids (11 ± 1.5 vs. 3 ± 1.3, P = 0.03) than the group of mice that received two testis tissue fragments. The objective of the third experiment was to assess the use to salvage testis tissue from neonatal/immature bison or deer donors using TTX into immunodeficient recipient mice as models for closely-related rare or endangered ungulates. Donor testis tissue fragments from two newborn bison calves (Bison bison bison) and a 2-mo-old white-tailed deer fawn (Odocoileus virginianus) were grafted under the back skin of gonadectomised nude mice (n = 15 and n = 7 for bison and deer groups, respectively, 8 testis fragments/mouse). To examine the potential effect of individual donors, we grafted four testis tissue fragments from one bison calf on one side of the recipient and four fragments from the second bison calf on the other side. Single grafts were surgically removed from representative recipient mice every 2 mo for up to 16- and 14 mo post-grafting, for bison and deer groups, respectively. The overall graft recovery rates were 69% and 63% for bison and deer groups, respectively. For bison grafts, a donor effect on efficiency of spermatogenesis was also observed. The weight of bison testis tissue xenografts increased (P < 0.02) ~4-fold by 2 mo and ~10-fold by 16 mo post-grafting, and gradual maturational changes were evident in the form of seminiferous tubule expansion starting at 2 mo, first appearance of spermatocytes at 6 mo, round spermatids at 12 mo, and elongated spermatids at 16 mo post-grafting. Testis tissue xenografts from donor white-tailed deer also showed a gradual development starting with tubular expansion by 2 mo and presence of spermatocytes by 6 mo post-grafting, round and elongated spermatids by 8 mo, followed by fully-formed spermatozoa by 12 mo post-grafting. The timing of complete spermatogenesis roughly corresponded to the reported timing of sexual maturation in these species. Taken together, the findings in this thesis suggest that male SCID mice provide a more suitable recipient model for TTX with neonatal porcine testis tissue; recipient mice can be grafted with as many as 16 testis tissue fragments for optimal results; and that TTX is a feasible strategy for salvaging genetic materials from immature males of rare or endangered ungulates that die prematurely

The Number of Grafted Fragments Affects the Outcome of Testis Tissue Xenografting from Piglets into Recipient Mice

To optimize the procedure for testis tissue xenografting, we grafted 2, 4, 8, or 16 small fragments of immature porcine testis tissue under the back skin of immunodeficient castrated mice (n = 10 mice/group). At 8 months post grafting, the graft recovery rate did not differ between groups; however, not only the total but also the average graft weights were higher (by ∼12-fold and ∼2.5-fold, resp.) in mice receiving 16 fragments than those receiving 2 fragments (P < .05). The recipient mice with 16 fragments had the largest vesicular glands (indicators of testosterone release by the grafts) compared with those with 2 fragments (P = .007). The grafts in the group of 16 fragments also had more (P < .05) percentage of tubules with round spermatids than those of the group of mice receiving 2 fragments. Therefore, recipient mice can be grafted with at least 16 testis tissue fragments for optimal results

Product-type operators between minimal M\"{o}bius invariant spaces and Zygmund type spaces

In this paper, we consider product-type operators $T^m_{u,v,\varphi}$ from minimal M\"{o}bius invariant spaces into Zygmund type spaces. So some characterizations for boundedness and essential norm of these operators are obtained. As a result some conditions for the compactness will be given

Evaluation of Shear Bond Strength and Antimicrobial Effects of Resin-Modified Glass Ionomer Containing Titanium Oxide and Silver Nanoparticles

Objectives Streptococcus mutans, as one of the most important cariogenic bacteria, is responsible for dental caries. To prevent and control dental caries, it is reasonable to use new materials and techniques for eradicating cariogenic bacteria. The present study aimed to evaluate and compare the antimicrobial effects of resin-modified glass ionomer (RMGI) containing silver and titanium oxide nanoparticles, on Streptococcus mutans (S. mutans) and to assess and compare the shear bond strength between coronal and radicular dentins. Methods This study investigated the antibacterial properties of 16 RMGI discs, containing 3 weight percent (wt.%) of silver and titanium nanoparticles prepared for each group. Also, the shear bond strength of RMGI discs containing nanoparticles between the coronal and radicular dentins were compared. Kolmogorov-Smirnov test was used to evaluate the normal distribution of data. Normally distributed data were analyzed and compared between the groups, using two-way ANOVA test; otherwise, Kruskal-Wallis test was performed to analyze the data. The level of statistical significance was set at 0.05. Results The mean colony count of S. mutans significantly reduced in both silver and titanium nanoparticle groups after 15 days compared to one-hour and 24-hour intervals (P&lt;0.0001). The shear bond strength test revealed no significant differences between the two experimental groups (P&gt;0.05). Conclusion Incorporation of silver and titanium oxide nanoparticles at a concentration of 3 wt.% yielded optimal antibacterial characteristics, without causing any significant changes in the shear bond strength. Comparison between nanoparticle containing RMGI and RMGI showed that over time it has more ability to create antibacterial properties against S. mutans bacteria

Effects of different doses of tamoxifen on the sperm parameters and chromatin quality in mice: An experimental model

Background: Tamoxifen (TX) is widely used for the treatment of male factor and idiopathic infertility. It has been shown that TX induces sperm production and so improves male fertility. Objective: This study evaluated the effects of different doses of TX on the sperm parameters and chromatin quality in mice. Materials and Methods: In this research, 24 male NMRI mice were divided into three groups including group A: control animal receiving vehicle; group B: the group receiving basal diet and TX 0.4 mg/kg/day; and group C: the group receiving basal diet and TX 0.6 mg/kg/day for 35 days. Thereafter, epididymal spermatozoa were analyzed for standard parameters and nuclear chromatin quality using Aniline Blue (AB) and Toluidine Blue (TB) staining. Results: The results indicated that although the TX did not affect the sperm count, motility, and viability parameters, it could elevate the percentage of sperm cells with abnormal morphology and abnormal chromatin at both doses. In addition, in comparison with the control mice, a significant elevation was observed in spermatozoa with residual histones (assessed by AB staining) at high doses of TX. Conclusion: Our experimental data in mice suggested that the use of TX for treating male infertility might increase the rates of spermatozoa with abnormal chromatin in a dose-dependent manner

The Association between Myocardial Perfusion Scan and Electrocardiographic Findings among Patients with Myocardial Ischemia

Introduction: The aim of this study was to determine the consistency of Electrocardiography (ECG) and myocardial perfusion scan findings of patients with myocardial ischemia at Firoozgar and Hazrat-Rasool hospitals.Methods: Electrocardiogram of 80 patients undergoing myocardial perfusion scans was analyzed. All patients had a stable angina. All patients with bundle branch blocks and history of MI and coronary bypass or angiography were excluded. Overall, 120 patients were evaluated with single photon emission tomography/myocardial perfusion imaging for ischemia and 80 patients had a positive test.Results: Forty-five percent of patients were female and 55% were male. The average age of patients was 61.48 years. Sixty-one patients (76.25%) had normal ECG and 19 patients (23.75) had pathological changes in their ECG. Eleven patients had ST segment depression and 6 patients had T wave inversion. Furthermore, 21 patients (26.25%) had lateral wall ischemia in their myocardial perfusion scan and 13 (16.25%) patients had septal wall ischemia. The ECG changes in male patients and hypertensive cases were more prominent.Conclusions: This study showed that ST-T changes (ST depression and T inversion) in the ECG are more suggestive of accuracy of myocardial ischemia and ECG

Assessment of Health Literacy and Self-care Behaviors among Patients Discharged from COVID-19 Wards

Introduction: The rapid outbreak of the new COVID-19 virus has become an international health challenge. Confronting the prevalence of this pathogenic virus requires, in the first step, health literacy and self-care on people’s part. Materials and Methods: This descriptive cross-sectional study was carried out over three months. A total of 67 patients discharged from a COVID-19 ward were selected randomly. Data were collected using a validated researcher-made questionnaire on health literacy and self-care. The data were then analyzed using SPSS software version 16. Results: Sixty-seven patients (mean age: 45.32 ± 9.39; age range: 29 - 87) were assessed. The majority were male (64.2%), married (79.1%), illiterate (44.8%), and homemaker or unemployed (37.3%). The overall mean score of health literacy and self-care was moderate. The results of the Pearson correlation test showed a significantly positive association between overall health literacy and its components as well as the total self-care and its components among the patients studied (p &lt;.001). Conclusion: Since self-care increases with health literacy among COVID-19 patients, it demands educational interventions in this area to improve health literacy

Predicting the price of second-hand vehicles using data mining techniques

The electronic commerce, known as “E-commerce”, has been boosted rapidly in recent years, and makes it possible to record all information such as price, location, customer’s review, search history, discount options, competitor’s price, and so on. Accessing to such rich source of data, companies can analyze their users’ behavior to improve the customer satisfaction as well as the revenue. This study aims to estimate the price of used light vehicles in a commercial website, Divar, which is a popular website in Iran for trading second-handed goods. At first, highlighted features were extracted from the description column using the three methods of Bag of Words (BOW), Latent Dirichlet Allocation (LDA), and Hierarchical Dirichlet Process (HDP). Second, a multiple linear regression model was fit to predict the product price based on its attributes and the highlighted features. The accuracy index of Actuals-Predictions Correlation, the min-max index, and MAPE methods were used to validate the proposed methods. Results showed that the BOW model is the best model with an Adjusted R-square of 0.7841