Sukumaran Anil

Is the presence of Helicobacter pylori in dental plaque of patients with chronic periodontitis a risk factor for gastric infection

BACKGROUND Helicobacter pylori is considered to be a pathogen responsible for gastritis and peptic ulcers, and a risk factor for gastric cancer. A periodontal pocket in the teeth of individuals with chronic periodontitis may function as a reservoir for H pylori. OBJECTIVE The present study was undertaken to evaluate whether the presence of H pylori in the dental plaque of patients with and without periodontitis correlates with gastric involvement. METHODS A total of 101 patients with dyspepsia were included in the present study. Subjects were divided into periodontitis and nonperiodontitis groups. For the detection of H pylori in dental plaque, samples were collected from two teeth using a periodontal curette. Subgingival plaque was obtained by inserting two sterile paper points into periodontal pockets for 20 s. This was followed by an upper gastrointestinal endoscopy and antral biopsies. RESULTS Sixty-five per cent of patients had dental plaque positive for H pylori and more than 50% harboured the bacteria in their stomach. Periodontitis patients had a significantly higher percentage of H pylori in their dental plaque (79% versus 43%; P<0.05) and the stomach (60% versus 33%; P<0.05) than patients with no periodontitis. Additionally, 78% of patients from the periodontitis group versus only 30% from the nonperiodontitis group had a positive test result for the coexistence of H pylori in both dental plaque and the stomach. CONCLUSION Patients with poor oral hygiene have a higher prevalence of H pylori in dental plaque and in the stomach. This finding suggests that the oral cavity may be a reservoir for H pylori, and potentially a source of transmission or reinfection.

Undersized Implant Site Preparation to Enhance Primary Implant Stability in Poor Bone Density: A Prospective Clinical Study

PURPOSE Achieving primary implant stability in areas with poor bone density is often challenging to the clinician. Previous research has suggested that modified surgical protocols might be beneficial in such situations. The objective of the present clinical study was to evaluate the survival rate of implants placed using undersized implant site preparation in areas with poor bone density. MATERIALS AND METHODS A total of 52 implants were placed in 29 patients. Of the 52 implants, 26 were surgically placed according to the standard drilling protocol (control group) and 26 were placed in low-density bone using an adapted bone drilling method (test group). The maximum insertion torque values and resonance frequency analysis measurements were also recorded. All implants were examined clinically and radiographically at follow-up visits during the study period. Oral hygiene status, bleeding on probing, peri-implant probing depth, and implant survival rate were assessed. RESULTS According to the survival criteria used in the present study, no failure was recorded, and the overall survival rate was 100% for both groups after 12 months. The mean probing depth was 2.75 ± 0.75 mm in the test group and 2.87 ± 0.79 mm in the control group. The mean insertion torque value was 35.19 ± 4.79 Ncm in the test group and 34.62 ± 5.82 Ncm in the control group. The resonance frequency analysis value was 68.58 ± 4.81 implant stability quotient and 66.69 ± 5.41 implant stability quotient in the test and control groups, respectively. The observed differences were not statistically significant (P > .05). CONCLUSIONS The results of the present study suggest that placement of implants by an adapted drilling technique in sites with poor bone density is beneficial in enhancing primary implant stability and improving the implant survival rate.

Role of dental plaque, saliva and periodontal disease in Helicobacter pylori infection.

Helicobacter pylori (H. pylori) infection is one of the most common bacterial infections in humans. Although H. pylori may be detected in the stomach of approximately half of the worlds population, the mechanisms of transmission of the microorganism from individual to individual are not yet clear. Transmission of H. pylori could occur through iatrogenic, fecal-oral, and oral-oral routes, and through food and water. The microorganism may be transmitted orally and has been detected in dental plaque and saliva. However, the role of the oral cavity in the transmission and recurrence of H. pylori infection has been the subject of debate. A large number of studies investigating the role of oral hygiene and periodontal disease in H. pylori infection have varied significantly in terms of their methodology and sample population, resulting in a wide variation in the reported results. Nevertheless, recent studies have not only shown that the microorganism can be detected fairly consistently from the oral cavity but also demonstrated that the chances of recurrence of H. pylori infection is more likely among patients who harbor the organism in the oral cavity. Furthermore, initial results from clinical trials have shown that H. pylori-positive dyspeptic patients may benefit from periodontal therapy. This paper attempts to review the current body of evidence regarding the role of dental plaque, saliva, and periodontal disease in H. pylori infection.

Seaweed Polysaccharide-Based Nanoparticles: Preparation and Applications for Drug Delivery

In recent years, there have been major advances and increasing amounts of research on the utilization of natural polymeric materials as drug delivery vehicles due to their biocompatibility and biodegradability. Seaweed polysaccharides are abundant resources and have been extensively studied for several biological, biomedical, and functional food applications. The exploration of seaweed polysaccharides for drug delivery applications is still in its infancy. Alginate, carrageenan, fucoidan, ulvan, and laminarin are polysaccharides commonly isolated from seaweed. These natural polymers can be converted into nanoparticles (NPs) by different types of methods, such as ionic gelation, emulsion, and polyelectrolyte complexing. Ionic gelation and polyelectrolyte complexing are commonly employed by adding cationic molecules to these anionic polymers to produce NPs of a desired shape, size, and charge. In the present review, we have discussed the preparation of seaweed polysaccharide-based NPs using different types of methods as well as their usage as carriers for the delivery of various therapeutic molecules (e.g., proteins, peptides, anti-cancer drugs, and antibiotics). Seaweed polysaccharide-based NPs exhibit suitable particle size, high drug encapsulation, and sustained drug release with high biocompatibility, thereby demonstrating their high potential for safe and efficient drug delivery.

Clinical Appearance of Oral Candida Infection and Therapeutic Strategies

Candida species present both as commensals and opportunistic pathogens of the oral cavity. For decades, it has enthralled the clinicians to investigate its pathogenicity and to improvise newer therapeutic regimens based on the updated molecular research. Candida is readily isolated from the oral cavity, but simple carriage does not predictably result in development of an infection. Whether it remains as a commensal, or transmutes into a pathogen, is usually determined by pre-existing or associated variations in the host immune system. The candida infections may range from non-life threatening superficial mucocutaneous disorders to invasive disseminated disease involving multiple organs. In fact, with the increase in number of AIDS cases, there is a resurgence of less common forms of oral candida infections. The treatment after confirmation of the diagnosis should include recognizing and eliminating the underlying causes such as ill-fitting oral appliances, history of medications (antibiotics, corticosteroids, etc.), immunological and endocrine disorders, nutritional deficiency states and prolonged hospitalization. Treatment with appropriate topical antifungal agents such as amphotericin, nystatin, or miconazole usually resolves the symptoms of superficial infection. Occasionally, administration of systemic antifungal agents may be necessary in immunocompromised patients, the selection of which should be based upon history of recent azole exposure, a history of intolerance to an antifungal agent, the dominant Candida species and current susceptibility data.

Preparation and characterization of chitosan-natural nano hydroxyapatite-fucoidan nanocomposites for bone tissue engineering.

Solid three dimensional (3D) composite scaffolds for bone tissue engineering were prepared using the freeze-drying method. The scaffolds were composed of chitosan, natural nano-hydroxyapatite (nHA) and fucoidan in the following combinations: chitosan, chitosan-fucoidan, chitosan-nHA, and chitosan-nHA-fucoidan. Fourier transform infrared spectroscopy (FT-IR), thermal gravimetric analysis (TGA), X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), and optical microscopy (OM) were used to determine the physiochemical constituents and the morphology of the scaffolds. The addition of nHA into the chitosan-fucoidan composite scaffold reduced the water uptake and water retention. FT-IR analysis confirmed the presence of a phosphate group in the chitosan-nHA-fucoidan scaffold. This group is present because of the presence of nHA (isolated via alkaline hydrolysis from salmon fish bones). Microscopic results indicated that the dispersion of nHA and fucoidan in the chitosan matrix was uniform with a pore size of 10-400μm. The composite demonstrated a suitable micro architecture for cell growth and nutrient supplementation. This compatibility was further elucidated in vitro using periosteum-derived mesenchymal stem cells (PMSCs). The cells demonstrated high biocompatibility and excellent mineralization for the chitosan-nHA-fucoidan scaffold. We believe that a chitosan-nHA-fucoidan composite is a promising biomaterial for the scaffold that can be used for bone tissue regeneration.

The effect of oral bacteria on Candida albicans germ-tube formation

Abstract: A total of eight bacterial isolates belonging to six species, and a select group of 12 oral Candida albicans isolates, were used to study the effect of bacteria on germ‐tube formation. Briefly, each bacterial suspension (105–6 cells/ml) was mixed with a C. albicans suspension (107 cells/ml) and incubated at 37 °C for 90 min with bovine serum, and the percentage germ‐tube‐positive Candida cells was quantified using a haemocytometer, under light microscopy. In general, out of eight bacteria, Streptococcus sanguis SK21A, Streptococcus salivarius SK56, Escherichia coli ATCC 25922, and S. salivarius OBU3 suppressed germ‐tube formation to varying degrees, with different C. albicans isolates. Porphyromonas gingivalis Pg 50, Lactobacillus casei ATCC 7469 and Prevotella intermedia OBU4 elicited significant enhancement of germ‐tube formation, whereas S. sanguis OBU 2 had no effect. E. coli ATCC 25922 was the only organism to show statistically significant suppression of germ‐tube formation (p=0.0312). A significant increase in the germ tube production of C. albicans isolated from HIV‐infected compared with HIV‐free individuals was also noted. The current results tend to suggest that commensal and transient oral bacterial populations may selectively influence the differential expression of germ‐tube‐forming ability of C. albicans isolates.

Antimicrobial and anticancer activities of porous chitosan-alginate biosynthesized silver nanoparticles

The main aim of this study was to obtain porous antimicrobial composites consisting of chitosan, alginate, and biosynthesized silver nanoparticles (AgNPs). Chitosan and alginate were used owing to their pore-forming capacity, while AgNPs were used for their antimicrobial property. The developed porous composites of chitosan-alginate-AgNPs were characterized using Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible spectroscopy, X-ray diffraction (XRD) analysis, and scanning electron microscopy (SEM). The FT-IR results revealed the presence of a strong chemical interaction between chitosan and alginate due to polyelectrolyte complex; whereas, the XRD results confirmed the presence of AgNPs in the composites. The dispersion of AgNPs in the porous membrane was uniform with a pore size of 50-500μm. Antimicrobial activity of the composites was checked with Escherichia coli and Staphylococcus aureus. The developed composites resulted in the formation of a zone of inhibition of 11±1mm for the Escherichia coli, and 10±1mm for Staphylococcus aureus. The bacterial filtration efficiency of chitosan-alginate-AgNPs was 1.5-times higher than that of the chitosan-alginate composite. The breast cancer cell line MDA-MB-231 was used to test the anticancer activity of the composites. The IC50 value of chitosan-alginate-AgNPs on MDA-MB-231 was 4.6mg. The developed chitosan-alginate-AgNPs composite showed a huge potential for its applications in antimicrobial filtration and cancer treatment.

Brief exposure to antimycotics reduces the extracellular phospholipase activity of Candida albicans and Candida tropicalis

Background: Although the phospholipase activity is considered a potential virulence determinant of the pathogenic Candida species, the effect of antimycotics on this attribute is not known. Hence we evaluated the phospholipase activity in 10 isolates each of Candida albicans and Candida tropicalis, after their exposure to antifungals. Methods: The impact of antimycotics on phospholipase activity was also assessed after exposure of the isolates to sub-minimum inhibitory concentrations of nystatin, amphotericin B and fluconazole. Results: All Candida isolates investigated exhibited phospholipase activity (Pz). In general C. albicans showed relatively higher Pz activity than C. tropicalis, and exposure of the isolates to antimycotics led to a significant (p < 0.05) reduction in the phospholipase activity. Nystatin and amphotericin B, but not fluconazole, significantly reduced the phospholipase activity of both Candida species. Conclusion: These observations, while confirming the higher virulence of C. albicans relative to C. tropicalis, demonstrate for the first time the effect of antifungal agents on extracellular phospholipases of these common opportunistic pathogens.

Marine Fish Proteins and Peptides for Cosmeceuticals: A Review

Marine fish provide a rich source of bioactive compounds such as proteins and peptides. The bioactive proteins and peptides derived from marine fish have gained enormous interest in nutraceutical, pharmaceutical, and cosmeceutical industries due to their broad spectrum of bioactivities, including antioxidant, antimicrobial, and anti-aging activities. Recently, the development of cosmeceuticals using marine fish-derived proteins and peptides obtained from chemical or enzymatical hydrolysis of fish processing by-products has increased rapidly owing to their activities in antioxidation and tissue regeneration. Marine fish-derived collagen has been utilized for the development of cosmeceutical products due to its abilities in skin repair and tissue regeneration. Marine fish-derived peptides have also been utilized for various cosmeceutical applications due to their antioxidant, antimicrobial, and matrix metalloproteinase inhibitory activities. In addition, marine fish-derived proteins and hydrolysates demonstrated efficient anti-photoaging activity. The present review highlights and presents an overview of the current status of the isolation and applications of marine fish-derived proteins and peptides. This review also demonstrates that marine fish-derived proteins and peptides have high potential for biocompatible and effective cosmeceuticals.