Optimization of glucose oxidase production by Aspergillus niger

The glucose oxidase was produced by fermentation using Aspergillus niger isolated from potato as producer organism and glucose as the carbon source (substrate). Maximum production of the enzyme (1.59 ìmoleHQMin-1ml-1) was achieved at 10% glucose concentration after 48 h of submerged fermentation. The pH for the optimal production of enzyme was found to be 5.5 (enzyme activity 1.56 ìmoleHQMin-1ml-1). Addition of urea (0.2%) and KH2PO4 (0.4%) into the fermentation medium increases enzyme activity (2.01 and 2.96 ìmoleHQMin-1ml-1, respectively) while MgSO4·7H2O was found to inhibit GOX production by A. niger.Key words: Glucose oxidase, Aspergillus niger, glucose oxidase

Flow cytometric analysis of childhood leukemias

Objective: To collect demographic data for childhood (less than 15 years) leukemias in Karachi, describe the accuracy of the cell surface markers routinely used in the flow cytometric analysis of leukemic cells and arrive at an ideal panel of antibodies for analyzing leukemic samiples. Materials and Methods: Data from 62 consecutive cases of childhood leukemias referred to the Department of Pathology, Aga Khan University Hospital. (AKUH) between January 1995 and December 1998 was analyzed using Epi Info Version 6. Flow cytometry on all samples was performed using standard protocols. Results: The mean age of patients was 8.2 years and 49 (79%) were males. Fifty (81%) had acute lymphoblastic leukemias of which 50% were CD1O positive and 24% CD10 negative Pre-B cell leukemias. Among all Pre B cell All 98% were positive for CD19, 96% for CD22, 89% for HLA-DR and 67% for CD10. Of the 10 AML cases, 100% were positive for CD33, 90% for CD13, 80% for CD19 and 70% for HLA-DR. Conclusion: The mean age in this study population was significantly higher and percentage of CD10 positive Pre-B All is lower than that in the West. Both these factors might be responsible for the poorer prognosis of these patients. It is not possible to specify a minimum or maximum panel of antibodies that should be used for phenotyping all cases of childhood leukemias. A certain degree or redundancy is essential in any panel of antibodies used for flow cytometry of leukemias

Use of intravenous anti-D in patients with refractory and relapsed immune thrombocytopenic purpura

Objective: To determine the response to IV anti-D and its comparison with splenectomy as second line therapy in refractory and relapsed cases of ITP, in the Aga Khan University Hospital, Karachi. Methods: A total of 23 patients with chronic ITP were treated with either anti-D or splenectomy as second line treatment. The patients were assessed for time to achieve a response to second line treatment, duration ofresponse and adverse events. Results: There were 12 patients in the anti-D group and 11 in the splenectomy group. The mean platelet count at presentation was 9,000/cumm. The mean age was 8.9 years and 13.0 years and the male to female ratio was 1:1 and 1:1.2 in anti-D and splenectomy group respectively. 54.5% of the patient in the anti-D group responded compared to 81.8% in the splenectomy group. Median time to achieve a response was 7 days in the anti-D group and 1 day in the splenectomy group. Mean time to relapse was 87.8 days in the anti-D group and 55.4 days in the splenectomy group. No adverse events were recorded for any of the infusions of anti-D and none of the patients had more than 0.5 gm /dl fall in the hemoglobin level following anti-D infusion. Conclusion: It was thus concluded that Anti-D is a relatively safe, convenient and effective therapy for chronic ITP and can be used as a splenectomy sparing agent when treatment is clinically indicated

Accuracy of digitally coded healing abutments: A systematic review

The aim of this systematic review was to evaluate the in vitro accuracy of dental implant impressions taken using digitally coded healing abutments (CHAs) compared with impressions taken with conventional techniques (CI) and/or within the CHA group at varying degrees of angulations for multiple implant units. Two independent reviewers conducted a systematic electronic search in the MedLine, PubMed, Google Scholar, Cochrane Library, Web of Science, and Scopus databases. Some of the employed key terms, combined with the help of Boolean operators, were: “digitally coded healing abutments”, “encode healing abutment”, “dental implants”, “impression accuracy”, “digital impression”, and “conventional impression”. Publication dates ranged from January 2010 to November 2022. A total of 7 articles fulfilled the inclusion criteria: 6 studies compared the accuracy of CHA with conventional pick-up impression techniques, and one study only used CHAs at different angulations and heights to compare accuracy within the group. The results were divided into Group A (elastomeric impression of CHA) and Group B (CHA + Intraoral scanner). According to the results of this systematic review, elastomeric impression of CHA performed poorly when compared to CI for multiple implants, although an intraoral scan of CHA appears to be more accurate. Within the CHA group, the angulation and visible height of CHA play a significant role in impression accuracy. However, more studies are needed before CHA can be recommended for all non-parallel multiple implant-supported restorations

Electrospinning of Chitosan-Based Solutions for Tissue Engineering and Regenerative Medicine

Electrospinning has been used for decades to generate nano-fibres via an electrically charged jet of polymer solution. This process is established on a spinning technique, using electrostatic forces to produce fine fibres from polymer solutions. Amongst, the electrospinning of available biopolymers (silk, cellulose, collagen, gelatine and hyaluronic acid), chitosan (CH) has shown a favourable outcome for tissue regeneration applications. The aim of the current review is to assess the current literature about electrospinning chitosan and its composite formulations for creating fibres in combination with other natural polymers to be employed in tissue engineering. In addition, various polymers blended with chitosan for electrospinning have been discussed in terms of their potential biomedical applications. The review shows that evidence exists in support of the favourable properties and biocompatibility of chitosan electrospun composite biomaterials for a range of applications. However, further research and in vivo studies are required to translate these materials from the laboratory to clinical applications

Potential of electrospun nanofibers for biomedical and dental applications

YesElectrospinning is a versatile technique that has gained popularity for various biomedical applications in recent years. Electrospinning is being used for fabricating nanofibers for various biomedical and dental applications such as tooth regeneration, wound healing and prevention of dental caries. Electrospun materials have the benefits of unique properties for instance, high surface area to volume ratio, enhanced cellular interactions, protein absorption to facilitate binding sites for cell receptors. Extensive research has been conducted to explore the potential of electrospun nanofibers for repair and regeneration of various dental and oral tissues including dental pulp, dentin, periodontal tissues, oral mucosa and skeletal tissues. However, there are a few limitations of electrospinning hindering the progress of these materials to practical or clinical applications. In terms of biomaterials aspects, the better understanding of controlled fabrication, properties and functioning of electrospun materials is required to overcome the limitations. More in vivo studies are definitely required to evaluate the biocompatibility of electrospun scaffolds. Furthermore, mechanical properties of such scaffolds should be enhanced so that they resist mechanical stresses during tissue regeneration applications. The objective of this article is to review the current progress of electrospun nanofibers for biomedical and dental applications. In addition, various aspects of electrospun materials in relation to potential dental applications have been discussed

Modern sedative agents and techniques used in dentistry for patients with special needs: A review

According to the World Health Organisation, approximately 1.3 billion people worldwide experience substantial disability due to physical, mental or sensory impairment. People with special needs require special consideration and more time or altered delivery methods when receiving dental treatments. Various factors, such as patients' lack of cooperation, cognitive impairment and complex medical status, may lead dental practitioners to recommend conscious sedation. Several pharmacological agents and administrative routes are available, which achieve varying levels of sedation ranging from minimal to deep. Pre-operative assessment and careful case selection are necessary to determine the appropriate sedative agent, route of administration and level of sedation for each patient. Thus, a thorough understanding of the pharmacokinetics, risks and benefits, and implications of various sedatives available for PSN is essential to achieve the desired clinical outcomes. This review critically presents the considerations associated with the use of various sedative agents for PSN in dentistry. Considerations include patients' pre-anaesthesia medical comorbidities, cardiorespiratory adverse effects and cooperativeness, and the viable alternative treatment modalities

Dental Applications of Nanodiamonds

YesNanodiamonds (NDs) have been used in various fields of medicine such as drug delivery, tissue regeneration and gene therapy. Although there has been research carried out investigated the potential of these remarkable materials in dentistry, to date no review has been published to summarize the studies conducted. Due to their target cell specificity, small size and fluorescence they have also been found to be usefulness in dentistry. Main applications of NDs in dentistry and medicine include guided tissue regeneration, reinforcement of polymers and drug delivery to treat infections and cancers. Recent research also suggests that NDs can also be used as bioactive or antibacterial dental implant coatings. However, to date, the research conducted on their biocompatibility is limited and inconclusive. Hence, substantially more in vitro and in vivo studies are required to envisage the future of NDs in dentistry. It is hoped that in the next decade these promising materials will find a variety of uses in routine dentistry

A Critical Assessment of the Congruency between Environmental DNA and Palaeoecology for the Biodiversity Monitoring and Palaeoenvironmental Reconstruction

The present study suggests that standardized methodology, careful site selection, and stratigraphy are essential for investigating ancient ecosystems in order to evaluate biodiversity and DNA-based time series. Based on specific keywords, this investigation reviewed 146 publications using the SCOPUS, Web of Science (WoS), PUBMED, and Google Scholar databases. Results indicate that environmental deoxyribose nucleic acid (eDNA) can be pivotal for assessing and conserving ecosystems. Our review revealed that in the last 12 years (January 2008–July 2021), 63% of the studies based on eDNA have been reported from aquatic ecosystems, 25% from marine habitats, and 12% from terrestrial environments. Out of studies conducted in aquatic systems using the environmental DNA (eDNA) technique, 63% of the investigations have been reported from freshwater ecosystems, with an utmost focus on fish diversity (40%). Further analysis of the literature reveals that during the same period, 24% of the investigations using the environmental DNA technique were carried out on invertebrates, 8% on mammals, 7% on plants, 6% on reptiles, and 5% on birds. The results obtained clearly indicate that the environmental DNA technique has a clear-cut edge over other biodiversity monitoring methods. Furthermore, we also found that eDNA, in conjunction with different dating techniques, can provide better insight into deciphering eco-evolutionary feedback. Therefore, an attempt has been made to offer extensive information on the application of dating methods for different taxa present in diverse ecosystems. Last, we provide suggestions and elucidations on how to overcome the caveats and delineate some of the research avenues that will likely shape this field in the near future. This paper aims to identify the gaps in environmental DNA (eDNA) investigations to help researchers, ecologists, and decision-makers to develop a holistic understanding of environmental DNA (eDNA) and its utility as a palaeoenvironmental contrivance

A Critical Assessment of the Congruency between Environmental DNA and Palaeoecology for the Biodiversity Monitoring and Palaeoenvironmental Reconstruction

The present study suggests that standardized methodology, careful site selection, and stratigraphy are essential for investigating ancient ecosystems in order to evaluate biodiversity and DNA-based time series. Based on specific keywords, this investigation reviewed 146 publications using the SCOPUS, Web of Science (WoS), PUBMED, and Google Scholar databases. Results indicate that environmental deoxyribose nucleic acid (eDNA) can be pivotal for assessing and conserving ecosystems. Our review revealed that in the last 12 years (January 2008–July 2021), 63% of the studies based on eDNA have been reported from aquatic ecosystems, 25% from marine habitats, and 12% from terrestrial environments. Out of studies conducted in aquatic systems using the environmental DNA (eDNA) technique, 63% of the investigations have been reported from freshwater ecosystems, with an utmost focus on fish diversity (40%). Further analysis of the literature reveals that during the same period, 24% of the investigations using the environmental DNA technique were carried out on invertebrates, 8% on mammals, 7% on plants, 6% on reptiles, and 5% on birds. The results obtained clearly indicate that the environmental DNA technique has a clear-cut edge over other biodiversity monitoring methods. Furthermore, we also found that eDNA, in conjunction with different dating techniques, can provide better insight into deciphering eco-evolutionary feedback. Therefore, an attempt has been made to offer extensive information on the application of dating methods for different taxa present in diverse ecosystems. Last, we provide suggestions and elucidations on how to overcome the caveats and delineate some of the research avenues that will likely shape this field in the near future. This paper aims to identify the gaps in environmental DNA (eDNA) investigations to help researchers, ecologists, and decision-makers to develop a holistic understanding of environmental DNA (eDNA) and its utility as a palaeoenvironmental contrivance