An In Vitro Study of Cellular and Molecular Mechanisms of Ligament Scarring

When ligaments such as the medial collateral ligament (MCL) are injured, they generally heal but form scar tissue, which is composed of a disorganized collagen matrix that is over-produced by fibroblasts. Scar tissue has inferior structural and mechanical properties, which can lead to joint instability. Excessive fibroblast contraction is thought to contribute to tissue scarring. Previous studies have shown that both TGF-â1 and TGF-â3 increase fibroblast contraction and collagen synthesis. However, TGF-â1 enhances scar tissue formation whereas TGF-â3 actually reduces it. In addition, both TGF-â isoforms have been found to increase the expression of á-SMA, which correlates with increased fibroblast contractility. An increase in tension at the wound site has also been found to increase á-SMA protein levels. Therefore these factors are all important in the wound healing process. The overall objective of this thesis research was to investigate cellular and molecular mechanisms that affect scar tissue formation in healing ligaments. Contraction forces, collagen synthesis, and á-SMA protein expression of healing and normal MCL fibroblasts in response to treatment with TGF-â1, TGF-â3, and collagen gel tension were investigated. A novel culture force monitor (CFM) system was used to quantify forces of fibroblast contraction. It was found that healing MCL fibroblasts produced greater contractile forces and higher levels of collagen synthesis than normal MCL fibroblasts. In addition, treatment with TGF-â1 or TGF-â3 increased contraction forces in healing fibroblasts compared to untreated controls, with TGF-â1 consistently producing greater contraction forces than treatment with TGF-â3. TGF-â1 and TGF-â3 also induced higher levels of á-SMA protein expression compared to untreated fibroblasts. Consistent with the contraction forces, fibroblasts treated with TGF-â1 expressed higher levels of á-SMA protein than those treated with TGF-â3. Further, it was found that when tension in gels embedded with normal MCL fibroblasts was released, expression of á-SMA protein also decreased. Thus, this study showed that healing and normal fibroblasts have differential contractile and collagen synthesis abilities. The results of this study showed that the presence of TGF-â1, TGF-â3, and tension in the matrix should be regulated to improve ligament healing. Decreasing the ratio of TGF-â1 to TGF-â3 in an injured ligament may decrease fibroblast contraction and thus reduce scar formation in healing MCLs. Finally, reducing tension levels in healing ligaments and hence down-regulating á-SMA protein expression may also decrease ligament scarring

Two Phosphodiesterases from Ustilago Maydis Share Structural and Biochemical Properties with Non-Fungal Phosphodiesterases

The dependence of Protein Kinase A (PKA) activity on cAMP levels is an important facet of the dimorphic switch between budding and filamentous growth as well as for pathogenicity in some fungi. To better understand these processes in the pathogenic fungus Ustilago maydis, we characterized the structure and biochemical functions of two phosphodiesterase (PDE) genes. Phosphodiesterases are enzymes involved in cAMP turnover and thus, contribute to the regulation of the cAMP-PKA signaling pathway. Two predicted homologs of PDEs were identified in the genome of U. maydis and hypothesized to be involved in cAMP turnover, thus regulating activity of the PKA catalytic subunit. Both umpde1 and umpde2 genes contain domains associated with phosphodiesterase activity predicted by InterPro analysis. Biochemical characterization of recombinantly produced UmPde1 (U. maydis Phosphodiesterase I) and UmPde2 demonstrated that both enzymes have phosphodiesterase activity in vitro, yet neither was inhibited by the phosphodiesterase inhibitor IBMX. Moreover, UmPde1 is specific for cAMP, while UmPde2 has broader substrate specificity, utilizing cAMP and cGMP as substrates. In addition, UmPde2 was also found to have nucleotide phosphatase activity that was higher with GMP compared to AMP. These results demonstrate that UmPde1 is a bona fide phosphodiesterase, while UmPde2 has more general activity as a cyclic nucleotide phosphodiesterase and/or GMP/AMP phosphatase. Thus, UmPde1 and UmPde2 likely have important roles in cell morphology and development and share some characteristics with a variety of non-fungal phosphodiesterases

Choriocarcinoma: a rare case of stomach metastasis

Choriocarcinoma is a rare form of cancer which commonly occurs in women of reproductive age, rarely in post-menopausal women and in women under 20 years of age. We report a rare case of uterine choriocarcinoma with stomach metastasis in a 29 year-old woman who presented with upper gastrointestinal symptoms. The presented case report emphasizes the need for innovative treatment approach and appropriate diagnostic technology to enable early diagnosis and correct treatment. Furthermore the case highlights the need for healthcare workers to consider rare causes of gastrointestinal signs and symptoms

Cytological dilemma of a rare subcutaneous fungal infection: Phaeoacremonium griseorubrum

Human disease caused by Phaeoacremonium species is rare. It was first reported in 1974 to cause subcutaneous tissue infection in the renal transplant recipient. Since then, only a few cases have been reported in the literature; however, underreporting is common in such cases due to incomplete or incorrect identification. Furthermore, some cases of subcutaneous infection in otherwise healthy patients may be asymptomatic and definitive identification of the etiological agent is not pursued. Identification of fungi at the species level is challenging by conventional methods; hence, final identification of fungi is based on culture. Phaeoacremonium has a very wide spectrum of presentation ranging from subcutaneous infections to fungemia and disseminated disease. We report a case of subcutaneous tissue swelling in an immunocompetent 55-year-old male, in whom etiology was traced to Phaeoacremonium griseorubrum. To the best of our knowledge, this report of P. griseorubrum causing human infection is second of its kind and the first from India. The patient did not respond well to oral itraconazole therapy and was advised surgical debridement with amphotericin B therapy

Using CFD simulations to investigate the shear stress in hydrodynamic cavitation reactors coupled with experimental validation using colony count measurements

The current work investigates the shear stress distribution in hydrodynamic cavitation reactors with two different geometries using CFD simulations. Venturi type (positive geometry) and bore (negative geometry) were used to induce cavitation. Experimental validation of the predictions from simulations was also conducted by calculating the reduction rate in the colony count of Legionella pneumophila , a pathogenic bacterial strain. Both the numerical and experimental studies revealed the significant influence of the shape of the cavitation-inducing geometry on the flow characteristics and the distribution of shear stress. The simulation data indicated high shear stress formation in the positive geometry as a venturi, with the cavitation ranges for the two reactors being far apart from each other. The experimental study also confirmed that the flow conditions in the venturi-type reactor were more favourable compared to the bore geometry, resulting in a bacterial reduction efficiency as high as 99.98%. It was clearly demonstrated that the geometry of the cavitating device plays a crucial role in deciding the shear stress and its efficacy for the desired applications as per the predictions of the simulation model validated by the experimental results

tert-Butyl N-{2-[bis­(prop-2-yn-1-yl)amino]­phen­yl}carbamate

In the crystal of the title compound, C17H20N2O2, the molecules are linked by C—H⋯O interactions. Intra­molecular C—H⋯O and N—H⋯N hydrogen bonds also occur

Managing dub with progesterone - locally or orally which is a better option?

Background: The levonorgestrel intrauterine system (LNG-IUS) is a safe and effective form of contraception used by millions of people worldwide. Other than this, it has many non-contraceptive benefits-treatments for dysfunctional uterine bleeding (DUB), fibroid uterus, endometriosis and endometrial hyperplasia.Methods: A prospective longitudinal comparative study was carried out at department of obstetrics and gynaecology S.N. Medical College, Agra, Uttar Pradesh, India including 100 women of 20-45 years of age group (comparable in all aspects), with DUB. All cases were subjected to detailed history, examination and baseline investigations- Hemoglobin (Hb), endometrial aspiration, histopathology and ultrasound pelvis (along with endometrial thickness) and PBAC scoring before starting the treatment. Then cases were randomly allocated in two equal groups. In group A LNG-IUS was inserted. In group B cases were prescribed oral medroxy progesterone acetate 10 mg bd from 5th and 25th day of menstrual cycle. Cases were followed at 1 month, 3 months and 6 months after starting treatment. At each follow-up visit primary outcome in terms of subjective assessment by patient, PBAC scores and secondary outcome as Hb levels and side-effects were recorded.Results: Reduction in PBAC Scores, improvement in Hb and reduction in endometrial thickness were seen with both treatment modalities but results were significantly (p <0.0001) better with LNG-IUS group as compared to MPA. LNG-IUS was found to be more effective in endometrial hyperplasia and proliferative type of endometrium.Conclusions: LNG-IUS is a good alternative to oral progesterone therapy for patients of DUB

Knowledge and attitude among Indian medical students towards thalassemia: a study in Delhi NCR

Background: Thalassemia can easily be prevented by awareness, education, screening, premarital genetic counselling and prenatal diagnosis. There are only a handful of articles on knowledge and awareness about thalassemia among general population or parents of thalassaemic children. Aims and objectives was to evaluate the level of awareness, knowledge and attitudes of medical students towards thalassemia as well as to analyse the differences if any between the first year and second year MBBS students and their correlation with various socio-demographic parameters.Methods: This was an institutional based cross sectional observational descriptive study regarding knowledge and attitude of first and second year MBBS students about thalassemia using a pre-designed, structured, self-administered questionnaire. Data was analyzed using SPSS software version 17. Values of p<0.05 were considered significant.Results: Mean knowledge scores of second year MBBS students compared to first year MBBS were 11.73±1.78 versus 10.8±1.92, the difference being statistically significant, however, the difference between mean attitude scores was not found to be significant. There was no effect of age, gender, region or Kuppuswamy’s socio-economic class on the knowledge or attitude of MBBS students towards thalassemia.Conclusions: Majority of the MBBS students had good knowledge and positive attitude towards thalassemia. To confirm the observations, large scale studies need to be conducted comprising of different study populations. Screening for thalassemia should be made mandatory, as part of medical examination, at entry to a medical college so that the medical college students are sensitized and can spread awareness among general population

A Correlation of Tumor Budding and Tumor Stroma Ratio with Clinicopathological Factors in Oral Squamous Cell Carcinoma

Background: Squamous cell carcinoma is the most common carcinoma in the head and neck region. Both tumor budding and tumor stroma ratio are being studied in the recent years in various solid tumors for their role as a prognostic marker, however the studies in oral squamous cell carcinoma are limited. Methods: A total of 50 patients of oral squamous cell carcinoma proved histologically were included in the study over a period of 4 months (July 2022-October 2022). Tumor budding(TB) and Tumor stroma ratio (TSR) were evaluated on routine hematoxylin and eosin stained sections and these were correlated with clinicopathological parameters. Statistical analysis was done using Chi-square test and p value &lt;.05 considered significant. Result: The mean age was 52.72 +_ 13.16 and M: F of 7.1:1. Most of the tumors were located on tongue (46%) followed by buccal mucosa (26%), gingivobuccal sulcus (12%) and retromolar trigone (8%). Palate and alveolus were the other sites involved constituting 4% each. Both TB and TSR were found to be significantly associated with grade of the tuumor, lymph node metastasis and size of the tumor. A highly significant correlation was also found between Tb and TSR with a p value &lt;.001. Conclusion: Both TB and TSR can be easily evaluated on routine H&amp;E sections and are highly reproducible and found to be reliable independent prognostic markers in OSCC. Thus, this simple and cost-effective method of prognostification which is currently lacking will help in identifying patients with poor prognosis and thus, individualise the treatment plan. Keywords: Tumor Budding, Oral squamous cell carcinoma, Tumor stroma ratio