Histomorphometric Study of the Tunics of Ductus Arteriosus in Human Fetal Cadavers Using the ImageJ Software.

INTRODUCTION: The ductus arteriosus (DA) connects the left pulmonary artery with the aorta during fetal life. Although it connects two elastic arteries, histological studies have shown that it is a muscular artery. There are very few studies on the histomorphometry of human fetal cadaveric DA. There are few studies on the changes in the tunics of the DA at various stages of fetal development. The present study aimed to observe the histomorphometric features of DA and its histological variations according to the gestational age of the fetus. METHODS: The study sample was DA dissected from 34 fetal cadavers of different gestational ages and stained with standard hematoxylin and eosin staining (H&E). We studied the structure of DA under a light microscope. We used ImageJ software (National Institutes of Health, Bethesda, Maryland) to measure the thickness of all three layers of the DA wall. RESULTS: The thickness of the DA wall was directly proportional to the gestational age of the fetus. In each trimester, we observed distinct histological changes in the tunics. CONCLUSION: The formation of multiple intimal mounds and the increase in intimal thickness observed during the last trimester are responsible for the closure of the ductus after birth. Elastosis is associated with patent DA. The disappearance of elastosis at a later gestational age ensures the closure of the ductus.

Anatomical variations of peroneus tertius and its clinical implications: case report with systematic literature review.

PURPOSE: Peroneus tertius (PT) or Fibularis tertius, a muscle of the anterior compartment of the leg is very distinctive to the Homo sapiens. This is because of the evolutionary acquisition of bipedal gait along with the eversion of the foot, which are unique to humans. It is considered as the fifth tendon of the extensor digitorum longus. Variations in the attachments of PT can cause stress fractures like the Jones fracture. PT has been extensively used in tendoplasty, tendon transfer and resection of the foot. The study aims to transpose the knowledge in variations of the morphology of PT from bench to bedside. METHODS: Routine dissection of a 64-year-old male cadaver revealed bilateral variations in the insertion of PT. This was documented photographically. The findings prompted a systematic literature review on the morphological variations of PT. An exhaustive search was undertaken through PubMed and Google Scholar databases to identify the published literature related to variations in the morphology of PT. Related anatomical studies of the variations in peroneus tertius were identified and a review of the literature was performed. RESULTS: Variations in the insertion of PT were observed bilaterally in the cadaver dissected by us. Statistical analysis revealed the absence of PT in 7.03% of lower limbs. 10% of studies showed accessory and duplicated PT each. Out of 20 articles reviewed, 51 lower limbs showed variation in origin, 230 lower limbs showed variations in insertion and 161 lower limbs showed other variations. CONCLUSION: PT muscle flap and tendon grafts are used in correcting the laxity of the ankle joint and foot drop. Absence of PT plays a crucial role in altering the mechanics of stress fractures of the 5th metatarsal. Thus, knowledge of the morphology of PT is crucial for plastic surgeons and orthopedic surgeons.

Effectiveness of flipped classroom model in teaching histology for first-year MBBS students based on competency-based blended learning: An interventional study.

BACKGROUND: With recent changes in the curriculum of bachelor of medicine and bachelor of surgery (MBBS) course to meet the global trends and to fulfill the standards expected from an Indian medical graduate, introduction of newer teaching methodologies becomes mandatory. The usage of flipped classroom (FCR) in medical education has always been rewarding. This study was to evaluate the effectiveness of FCR as a teaching method in comparison with traditional lectures in histology sessions in Sri Ramaswamy Memorial (SRM) Medical College Hospital and Research Centre, Chennai, Tamil Nadu, India. MATERIALS AND METHODS: This interventional study was conducted among the 1st year MBBS students in SRM Medical College Hospital and Research Centre for a period of 1 year (2018-2019 academic year). The histology sessions were taught using both traditional lectures and FCR methodology. Pre- and posttests were conducted for each traditional and FCR session with ten multiple-choice questions pertaining to that topic. Students' performance was assessed by paired t-test (for pre- and posttest comparisons) and independent t-test (for traditional and FCR posttest mark comparison) using SPSS software version 26. A feedback survey based on Likert scale was also conducted on the students and was analyzed. P < 0.05 was considered statistically significant. RESULTS: Posttest marks had statistically significantly improved when compared to pretest marks (P < 0.0001) in both traditional and FCR teaching methods. Comparison of posttest marks showed statistically significantly higher marks in FCR when compared to traditional teaching (P < 0.0001). Similarly, students' feedback survey showed that FCR benefitted the students in achieving the competency required. CONCLUSION: FCR methodology of teaching histology had a very impressive outcome and the students' perception was very positive.

Poly-ε-Caprolactone/Gelatin Hybrid Electrospun Composite Nanofibrous Mats Containing Ultrasound Assisted Herbal Extract: Antimicrobial and Cell Proliferation Study.

Electrospun fibers have emerged as promising materials in the field of biomedicine, due to their superior physical and cell supportive properties. In particular, electrospun mats are being developed for advanced wound dressing applications. Such applications require the firers to possess excellent antimicrobial properties in order to inhibit potential microbial colonization from resident and non-resident bacteria. In this study, we have developed Poly-ε-Caprolactone /gelatin hybrid composite mats loaded with natural herbal extract (Gymnema sylvestre) to prevent bacterial colonization. As-spun scaffolds exhibited good wettability and desirable mechanical properties retaining their fibrous structure after immersing them in phosphate buffered saline (pH 7.2) for up to 30 days. The initial burst release of Gymnema sylvestre prevented the colonization of bacteria as confirmed by the radial disc diffusion assay. Furthermore, the electrospun mats promoted cellular attachment, spreading and proliferation of human primary dermal fibroblasts and cultured keratinocytes, which are crucial parenchymal cell-types involved in the skin recovery process. Overall these results demonstrated the utility of Gymnema sylvestre impregnated electrospun PCL/Gelatin nanofibrous mats as an effective antimicrobial wound dressing.