Eyeball simulator for extraocular muscles

Learning about human eye movements broadens our comprehension of the visuomotor system and aids in the effective management of strabismus. One’s clinical practice is improved by a dynamic simulation of human eye movements using physical models of the extraocular muscles (EOMs). We use our eyeball model to teach the basics of strabismus to undergraduate students and ophthalmology residents. In Listing’s plane, extraocular movements of each muscle and the angle demonstration are being used to familiarize students with their knowledge. The degree of the residents’ understanding of strabismus is significantly influenced by the eyeball strabismus simulator. This model is an inexpensive, Do It Yourself (DIY) model that is simple to build.

Primary eye care in pediatric population-I study (PREPP-I study): Demographic and clinical profile of pediatric patients treated in six major vision centers of a tertiary eye care facility in South India

Purpose: The study intends to evaluate the demographic and clinical profile of pediatric patients (0–18 years) attending six vision centers (VCs) of a tertiary eye care facility in south India. Methods: This is a cross?sectional observation study conducted at six major peripheral VCs of a tertiary eye care facility in South India from June 20 to Dec 20. All children presenting at the VCs under a base hospital (BH) in Pondicherry, whose parents gave consent were included. Data were entered by the ophthalmic assistants in the VC and cross checked by the principal investigator at the BH. Results: A total of 250 pediatric patients were brought to the VCs during the study period, predominantly males (60.8%), with a mean age of 8.2 ± 4.5 years (0– 18 years). Half of them were staying within 5 km from the VCs. Most children were escorted by their parents (88%), and the expenditure of travel to the VC was affordable for most of the parents (75%). Also, 53.6% of patients were in their primary school, while schooling had not started for 28% of children. Visual acuity (VA) could be assessed only for school?going children and older children due to lack of age?matched VA assessment tools. Most children (91.3%) had uncorrected VA better than or equal to 6/18 in the better eye, and approximately 3% had VA worse than 6/60. All patients had best corrected VA of 6/6–6/18 after cycloplegic refraction. Most children reported to the VC for allergic conjunctivitis (25%), followed by refractive error (13%) and squint (10.4%). Urgent referral to the BH was made for 47 children. Conclusion: Primary eye care in pediatric population?I (PREPP?I) showed that most children can be treated at the VCs and only one?fifth of the children require active intervention at higher referral centers. Further study on satisfaction of services provided for pediatric patients in these VCs and barriers of not reporting to the BH when referred are considered for the PREPP?II study

Important signs to check posterior capsule integrity

For beginner surgeons, it is difficult to recognize the posterior capsule during cataract surgery. In the case of brown cataracts with a thin posterior capsule and in cataracts with asteroid hyalosis, it is difficult to identify the capsule before intraocular lens (IOL) implantation even for expert surgeons. Here we illustrate five important signs, which can be practiced in routine cases to make sure the posterior capsule is intact, before IOL implantation.

Clinical profile and management of sixth nerve palsy in pediatric patients (0–15 years) in Southern India – A hospital-based study

Purpose: This study was done to evaluate the clinical profile in pediatric patients (0–16 years) presenting with acute onset esotropia due to sixth nerve palsy and its management options in a tertiary care set up of Southern India. Methods: A total of 12 patients presenting to our OPD with acute onset esotropia due to sixth nerve palsies were included in this retrospective study. All patients were observed for 6 months and managed with prism and/or patching while waiting for spontaneous resolution and later managed surgically. Neuroimaging was done in all cases. Results: The mean deviation of esotropia at presentation was 30.17 ± 5.7 Prism Diopter (range 12–50 Prism Diopter 95% CI, SD 10.11). Mean age of the patients during presentation was 8.6 ± 2.4 years (range: 1–15 years, SD 4.27). Among the common causes of sixth nerve palsy in our study population were trauma and idiopathic intracranial hypertension followed by tumor and miscellaneous causes. Only three patients underwent surgical correction of residual deviation after a waiting period of 6 months for self?resolution. Spontaneous resolution was observed in 41.6% patients, and surgical correction (unilateral resection–recession) was done in 25% of the patients with good surgical outcome. Conclusion: At 1?year follow up, the motor outcome was satisfactory except for one patient who had diffuse pontine glioma and had worsening neurological symptoms on follow?up

A study of referral pattern to pediatric ophthalmology department in a tertiary eye-care center of South-India

Purpose: The study was aimed at finding out the present pattern of referrals to the Pediatric Ophthalmology outpatient department (OPD) in a tertiary eye care hospital and thus identify the discrepancy of referral, if any, which would help to modify and enhance the practice guidelines. Methods: The study was conducted by retrospectively collecting data from all referral letters that were already uploaded in the Electronic Medical Report (EMR) against all patients from June 2019 to December 2019. All pediatric patients in the age group of 0–16 years were included in the study. The practicing field of referring clinicians was noted along with the maximum information that could be collected from the referral letter and were thus assessed for the quality, accuracy, and timely referral. Results: Out of 77 referrals received in the study period, six referral letters neither had any mention of the designation of the referring clinician nor any specific diagnosis or details. Thus, only 71 patients were included for further study. The referring clinicians were mainly ophthalmologists, pediatricians, general practitioners (GPs), and others (cardiologists, neurologists). Maximum patients were referred by ophthalmologists (76%) but visual acuity was noted only for 30% of these patients. Almost half of the referral diagnosis was accurate. Pediatrician referrals were found to be more detailed and précised. Conclusion: There is a need for a standardized hospital?specific format of referrals and basic training to primary care providers on some simple tests (Lights reflex tests) for identifying the “red flags” in pediatric eye examination and thus enhancing the quality and timely referral per se

Dermoid cyst in the floor of the mouth

@#Dermoid cysts are rare developmental benign lesions that arise as a result of ectodermal differentiation of multipotent cells. Histologically the cysts are classified as dermoid, epidermoid and teratoid cysts depending on the presence of adnexal structures and derivatives of germ layers. When dermoid cysts appear in the floor of the mouth they can cause difficulty in deglutition and respiration. The differential diagnosis of dermoid cyst could be infection, ranulaor tumor. Intraoral or extra oral approach for enucleation is the method of treatment. Dermoid cysts have a good prognosis with low malignancy and recurrence rate. A case report of a dermoid cyst in the floor of the mouth is presented in this paper along with clinical, histopathological evaluation and the treatment.

Potential gene regulatory role for cyclin D3 in muscle cells.

Cyclin D3 is important for muscle development and regeneration, and is involved in post-mitotic arrest of muscle cells. Cyclin D3 also has cell-cycle-independent functions such as regulation of specific genes in other tissues. Ectopic expression of cyclin D3 in myoblasts, where it is normally undetectable, promotes muscle gene expression and faster differentiation kinetics upon serum depletion. In the present study, we investigated the mechanistic role of cyclin D3 in muscle gene regulation. We initially showed by mutational analysis that a stable and functional cyclin D3 was required for promoting muscle differentiation. Using chromatin immunoprecipitation assays, we demonstrated that expression of cyclin D3 in undifferentiated myoblasts altered histone epigenetic marks at promoters of muscle-specific genes like MyoD, Pax7, myogenin and muscle creatine kinase but not non-muscle genes. Cyclin D3 expression also reduced the mRNA levels of certain epigenetic modifier genes. Our data suggest that epigenetic modulation of muscle-specific genes in cyclin-D3-expressing myoblasts may be responsible for faster differentiation kinetics upon serum depletion. Our results have implications for a regulatory role for cyclin D3 in muscle-specific gene activation.

Lamins, laminopathies and disease mechanisms: Possible role for proteasomal degradation of key regulatory proteins.

Lamins are major structural proteins of the nucleus and are essential for nuclear integrity and organization of nuclear functions. Mutations in the human lamin genes lead to highly degenerative genetic diseases that affect a number of different tissues such as muscle, adipose or neuronal tissues, or cause premature ageing syndromes. New findings on the role of lamins in cellular signalling pathways, as well as in ubiquitin-mediated proteasomal degradation, have given important insights into possible mechanisms of pathogenesis.

Differential dynamics of splicing factor SC35 during the cell cycle.

Pre-mRNA splicing factors are enriched in nuclear domains termed interchromatin granule clusters or nuclear speckles. During mitosis, nuclear speckles are disassembled by metaphase and reassembled in telophase in structures termed mitotic interchromatin granules (MIGs). We analysed the dynamics of the splicing factor SC35 in interphase and mitotic cells. In HeLa cells expressing green fluorescent protein (GFP)-SC35, this was localized in speckles during interphase and dispersed in metaphase. In telophase, GFP-SC35 was highly enriched within telophase nuclei and also detected in MIGs. Fluorescence recovery after photobleaching (FRAP) experiments revealed that the mobility of GFP-SC35 was distinct in different mitotic compartments. Interestingly, the mobility of GFP-SC35 was 3-fold higher in the cytoplasm of metaphase cells compared with interphase speckles, the nucleoplasm or MIGs. Treatment of cells with inhibitors of cyclin-dependent kinases (cdks) caused changes in the organization of nuclear compartments such as nuclear speckles and nucleoli, with corresponding changes in the mobility of GFP-SC35 and GFP-fibrillarin. Our results suggest that the dynamics of SC35 are significantly influenced by the organization of the compartment in which it is localized during the cell cycle.

Retrospective and prospective study of ovarian tumours and tumour-like lesions.

Two hundred and thirty three cases of ovarian tumours and tumour like lesions were studied. Of these 233 cases, 96 cases were of ovarian tumours and 137 were tumour like lesions of the ovary. Of the 96 cases of ovarian tumours, 72.9% were benign, 4.1% were borderline and 22.9% were malignant. Histologically surface epithelial tumours were the commonest (48.8%) followed by germ cell tumours (23.9%), sex cord stromal tumours (8.3%) and metastatic tumours (2.0%). Ultrasound guided FNAC done in cases of ovarian tumours showed an accuracy of 100% for malignant lesions and 100% for benign and borderline lesions when compared with histopathological diagnosis. Of the non neoplastic lesions follicular cysts and corpus leuteal cysts were commonest (80.2%). Tuberculosis constituted (2.9%) cases and was the major cause of clinical diagnostic pitfalls for cases in which a clinical diagnosis of ovarian neoplasm was made.

Laminopathies: multiple disorders arising from defects in nuclear architecture.

Lamins are the major structural proteins of the nucleus in an animal cell. In addition to being essential for nuclear integrity and assembly, lamins are involved in the organization of nuclear processes such as DNA replication, transcription and repair. Mutations in the human lamin A gene lead to highly debilitating genetic disorders that primarily affect muscle, adipose, bone or neuronal tissues and also cause premature ageing syndromes. Mutant lamins alter nuclear integrity and hinder signalling pathways involved in muscle differentiation and adipocyte differentiation, suggesting tissue-specific roles for lamins. Furthermore, cells expressing mutant lamins are impaired in their response to DNA damaging agents. Recent reports indicate that certain lamin mutations act in a dominant negative manner to cause nuclear defects and cellular toxicity, and suggest a possible role for aberrant lamins in normal ageing processes.

Towards understanding lamin gene regulation.

The lamins are components of the nuclear lamina, which forms a fibrous meshwork lining the inner nuclear membrane. Lamina-membrane interactions play a crucial role during nuclear disassembly and reassembly at mitosis, whereas lamina-chromatin association has been proposed to be essential for chromatin organization. The composition of the lamina changes considerably during embryonic development and cell differentiation. Recent studies have provided insights into the regulation of the lamin genes.

Inhibition of avian myeloblastosis virus reverse transcriptase by an RNA-binding protein from plasma membranes of normal and tumor cells.

Purified plasma membranes from normal rat liver, a rat hepatoma and a rat hepatic fibrosarcoma have been shown to contain a protein which drastically inhibits avian myeloblastosis virus reverse transcriptase activity. The inhibition is caused by the binding of the protein to the template. The binding and the consequent inhibition of enzyme activity are template-specific; copying of RNA templates is inhibited whilst that of DNA templates remains unaffected. Investigations using different templates suggest that the inhibitory protein has a stronger binding affinity for G, C-rich templates. The inhibitor appears to have a wide distribution in plasma membranes from diverse sources.