Potential of microbial-derived biosurfactants for oral applications-a systematic review.

BACKGROUND: Biosurfactants are amphiphilic compounds produced by various microorganisms. Current research evaluates diverse types of biosurfactants against a range of oral pathogens. OBJECTIVES: This systematic review aims to explore the potential of microbial-derived biosurfactants for oral applications. METHODOLOGY: A systematic literature search was performed utilizing PubMed-MEDLINE, Scopus, and Web of Science databases with designated keywords. The results were registered in the PROSPERO database and conducted following the PRISMA checklist. Criteria for eligibility, guided by the PICOS framework, were established for both inclusion and exclusion criteria. The QUIN tool was used to assess the bias risk for in vitro dentistry studies. RESULTS: Among the initial 357 findings, ten studies were selected for further analysis. The outcomes of this systematic review reveal that both crude and purified forms of biosurfactants exhibit antimicrobial and antibiofilm properties against various oral pathogens. Noteworthy applications of biosurfactants in oral products include mouthwash, toothpaste, and implant coating. CONCLUSION: Biosurfactants have garnered considerable interest and demonstrated their potential for application in oral health. This is attributed to their surface-active properties, antiadhesive activity, biodegradability, and antimicrobial effectiveness against a variety of oral microorganisms, including bacteria and fungi.

Establishing transducers-dependent sensorineural acuity level normative data among young Malaysian adults.

INTRODUCTION: The sensorineural acuity level (SAL) test was developed as an alternative assessment to estimate bone conduction (BC) thresholds in cases where masking problems occur in pure tone audiometry (PTA). Nevertheless, prior to its clinical application, the respective SAL normative data must be made available. As such, the present study was carried out to establish SAL normative data using an insert earphone and two different commercially available bone transducers. Additionally, to determine the effect of earphone type on SAL test results, it was also of interest to compare the present study's findings with those of a previous study (that used a headphone to derive SAL normative data). MATERIALS AND METHODS: In this repeated-measures study, 40 Malaysian adults (aged 19-26 years) with normal hearing bilaterally (based on PTA results) were enrolled. They then underwent the SAL test based on the recommended protocol by Jerger and Tillman (1960). The SAL normative data for each ear were obtained by calculating the differences between air conduction (AC) thresholds in quiet and AC thresholds in noise by means of insert earphone, B71 and B81 bone vibrators. RESULTS: The SAL normative values were comparable between the ears (p > 0.05), and the data were pooled for subsequent analyses (n = 80 ears). Relative to B81 bone transducer, B71 bone vibrator produced statistically higher SAL normative data at all frequencies (p < 0.05). The SAL normative values established by the present study were statistically lower than those of the previous study (that utilised headphones) at most of frequencies tested (p < 0.05). CONCLUSIONS: The SAL normative data produced by the two bone vibrators were significantly different. The SAL normative values were also affected by the type of earphone used. While conducting the SAL test on Malaysian patients, the information provided by this study can be useful to guide the respective clinicians in choosing the appropriate normative data.

Advances and challenges in regenerative dentistry: A systematic review of calcium phosphate and silicate-based materials on human dental pulp stem cells.

Conventional dentistry faces limitations in preserving tooth health due to the finite lifespan of restorative materials. Regenerative dentistry, utilizing stem cells and bioactive materials, offers a promising approach for regenerating dental tissues. Human dental pulp stem cells (hDPSCs) and bioactive materials like calcium phosphate (CaP) and silicate-based materials have shown potential for dental tissue regeneration. This systematic review aims to investigate the effects of CaP and silicate-based materials on hDPSCs through in vitro studies published since 2015. Following the PRISMA guidelines, a comprehensive search strategy was implemented in PubMed MedLine, Cochrane, and ScienceDirect databases. Eligibility criteria were established using the PICOS scheme. Data extraction and risk of bias (RoB) assessment were conducted, with the included studies assessed for bias using the Office of Health and Translation (OHAT) RoB tool. The research has been registered at OSF Registries. Ten in vitro studies met the eligibility criteria out of 1088 initial studies. Methodological heterogeneity and the use of self-synthesized biomaterials with limited generalizability were observed in the included study. The findings highlight the positive effect of CaP and silicate-based materials on hDPSCs viability, adhesion, migration, proliferation, and differentiation. While the overall RoB assessment indicated satisfactory credibility of the reviewed studies, the limited number of studies and methodological heterogeneity pose challenges for quantitative research. In conclusion, this systematic review provides valuable insights into the effects of CaP and silicate-based materials on hDPSCs. Further research is awaited to enhance our understanding and optimize regenerative dental treatments using bioactive materials and hDPSCs, which promise to improve patient outcomes.

Oral mycobiome in community-dwelling elderly and its relation to oral and general health conditions.

OBJECTIVE: Oral fungal infection is generally associated with dysbiosis related to antibiotic use, immunodeficiency, or frailty. However, fungal colonization in a typical population without apparent symptoms and its associated conditions are poorly understood. In this study, oral fungal colonization in community-dwelling and independently living elderly populations was evaluated and factors affecting fungal colonization were analyzed. SUBJECTS AND METHODS: The subjects (410; 181 males and 229 females) were 75-99 years of age; those under prior antibiotic use were excluded. Fungal populations in the saliva were evaluated by PCR-based molecular techniques. Body mass index (BMI), smoking habits, and oral health conditions were examined. RESULTS: Salivary fungal amounts exceeded 104  CFU/ml in 63 (15.4%) of 410 subjects. Candida albicans was most frequently detected (98.4%), followed by Candida glabrata (54.0%), and Candida dubliniensis (38.1%) in those subjects with fungi at 104  CFU/ml or over. Fungi at 104  CFU/ml or over in the presence of C. glabrata or C. dubliniensis was significantly associated with low BMI. CONCLUSIONS: Candida albicans, C. glabrata, and C. dubliniensis dominated the oral mycobiome in Japanese community-dwelling elderly. Lower BMI might signify compromised health status and thus could result in susceptibility to specific candidiasis by C. glabrata and C. dubliniensis.

Ipsilateral and contralateral recordings of the 40-Hz auditory steady state response (ASSR): Which one is better?

OBJECTIVE: Few studies have investigated the auditory steady state response (ASSR) thresholds evoked by ipsilateral and contralateral stimulation. The present study was conducted to compare 40-Hz ASSR thresholds between ipsilateral and contralateral recordings at specific test frequencies. METHODS: Twenty young female subjects with normal hearing bilaterally (hearing level ≤ 20 dB HL across speech frequencies) were included in the study. One-octave-wide narrow band CE-chirp® stimuli centred at 500, 1000, 2000 and 4000 Hz with 40 Hz modulation frequency (MF) were presented ipsilaterally and contralaterally to each subject through insert earphones. The ASSR thresholds were obtained for each recording condition. RESULTS: The mean ASSR thresholds were higher for contralateral recording than for ipsilateral recording at all test frequencies, but analysis using the paired t-test revealed that the differences were not significant at any of the test frequencies (p>0.05). Comparing the ASSR thresholds among the test frequencies for the two recording conditions, there were no significant differences as determined using one-way ANOVA (p>0.05). CONCLUSION: The 40-Hz ASSR thresholds can be reliably recorded with ipsilateral and contralateral stimulation. For objective determination of hearing thresholds in young women, either ipsilateral or contralateral ASSR recording is appropriate. Nevertheless, the combination of both recordings might increase the diagnostic value of 40-Hz ASSR in estimating behavioural hearing thresholds.

Microbial community in persistent apical periodontitis: a 16S rRNA gene clone library analysis.

AIM: To characterize the microbial composition of persistent periapical lesions of root filled teeth using a molecular genetics approach. METHODOLOGY: Apical lesion samples were collected from 12 patients (23-80 years old) who visited the Kyushu University Hospital for apicectomy with persistent periapical lesions associated with root filled teeth. DNA was directly extracted from each sample and the microbial composition was comprehensively analysed using clone library analysis of the 16S rRNA gene. Enterococcus faecalis, Candida albicans and specific fimA genotypes of Porphyromonas gingivalis were confirmed using polymerase chain reaction (PCR) analysis with specific primers. RESULTS: Bacteria were detected in all samples, and the dominant findings were P. gingivalis (19.9%), Fusobacterium nucleatum (11.2%) and Propionibacterium acnes (9%). Bacterial diversity was greater in symptomatic lesions than in asymptomatic ones. In addition, the following bacteria or bacterial combinations were characteristic to symptomatic lesions: Prevotella spp., Treponema spp., Peptostreptococcaceae sp. HOT-113, Olsenella uli, Slackia exigua, Selemonas infelix, P. gingivalis with type IV fimA, and a combination of P. gingivalis, F. nucleatum, and Peptostreptococcaceae sp. HOT-113 and predominance of Streptococcus spp. On the other hand, neither Enterococcus faecalis nor C. albicans were detected in any of the samples. CONCLUSION: Whilst a diverse bacterial species were observed in the persistent apical lesions, some characteristic patterns of bacterial community were found in the symptomatic lesions. The diverse variation of community indicates that bacterial combinations as a community may cause persistent inflammation in periapical tissues rather than specific bacterial species.

Heme oxygenase-1 induction protects against hypertension associated with diabetes: effect on exaggerated vascular contractility.

Disturbances in vascular reactivity are important components of diabetes-evoked hypertension. Heme oxygenase-1 (HO-1) is a homeostatic enzyme upregulated in stress. This study aims to investigate the protective effect of HO-1 against diabetes-evoked hypertension. Rats were left 8 weeks after diabetes induction with streptozotocin to induce vascular dysfunction in the diabetic groups. HO-1 inducers, hemin and curcumin, were daily administrated in the last 6 weeks in the treated groups after 2 weeks of induction. Then, at the end of the study (8 weeks), HO-1 protein level was assessed by immunofluorescence; blood pressure (BP) was recorded; isolated aorta reactivity to phenylephrine (PE) and KCl was studied; reactive oxygen species (ROS) generation was determined; and serum level of glucose, advanced glycation end products (AGEs), and tumor necrosis factor alpha (TNF-α) were determined. While not affected by diabetes, HO-1 protein expression was strongly induced by hemin or curcumin administration. Compared with control animals, diabetes increased systolic and pulse BP. Induction of HO-1 by hemin or curcumin significantly reduced elevated systolic BP and abolished elevated pulse BP without affecting the developed hyperglycemia or AGEs level. The possibility that alterations in vascular reactivity contributed to diabetes-HO-1 BP interaction was investigated. Diabetes increased contractile response of the aorta to PE and KCl, while HO-1 induction by curcumin or hemin prevented aorta-exaggerated response to PE and KCl. Furthermore, the competitive HO inhibitor, tin protoporphyrin, abolished the protective effect of hemin. Diabetes was accompanied with elevated level of TNF-α and ROS generation, while HO-1 induction abrogated increased TNF-α and ROS generation. Collectively, induction of HO-1 protects against hypertension associated with diabetes via ameliorating exaggerated vascular contractility by reducing TNF-α and aortic ROS levels.

Gender differences in coping skills of parents with hearing-impaired children.

OBJECTIVE: To assess differences between the coping strategies of the mothers and fathers with hearing-impaired children. METHODOLOGY: A cross-sectional study was conducted looking at parents of children with moderate to profound hearing impairment. The parents with more than one child with a hearing impairment, the parents of children with additional disabilities and syndromes, single parents, and parents with their own hearing impairments were excluded from the study. A Brief COPE Scale questionnaire translated into Malay was used to assess the coping strategies. The questionnaire includes 28 items and was rated using a four-point Likert scale. Independent t-testing was used to compare the coping strategies of mothers and fathers. Simple linear regression was used to determine the association between age and coping strategies. RESULTS: There were 72 participants. The number of mothers and fathers was equal. Religion, active coping and acceptance were the highest three scores in the domains, while substance use and behavioural disengagement were least used in both groups. The domains of religion, seeking emotional support and seeking instrumental support scored significantly higher in mothers than in fathers (p < 0.05). There was a significant difference between the two groups in terms of problem-focused strategies (p = 0.016) but not in terms of emotional-focused strategies (p = 0.134). There were significant negative linear correlations between age and seeking emotional support, humour and instrumental support ( p < 0.05). CONCLUSION: There were gender differences in the coping strategies among parents with hearing-impaired children. These are important factors that should be considered when counselling and establishing support groups for the parents of these children.

Screening of dental staff nurses for noise induced hearing loss.

PROBLEMS/OBJECTIVES: The effect of noise on employees of dental clinics is debatable. The purposes of this study were to determine the intensity and frequency components of dental instruments used by dental staff nurses and the prevalence of noise induced hearing loss. METHODOLOGY: We performed a comparative, cross sectional study on a group of dental staff nurses. Participants underwent ear examination followed by pure tone audiometry. Pure tone audiometry was performed at least 48 hours after the participants were free from noise exposure. Noise induced hearing loss was defined as failed definitive threshold at a frequency of 4000 Hz greater than 20 dB. The intensity level, noise spectrum, and frequency of hand piece, saliva suction, and scaler were recorded during the dental procedure. RESULTS: A total of 65 dental staff nurses were included. The mean intensity of hand pieces, scalers, and saliva suctions were 88.7 (SD2.2), 87.1 (SD2.6), and 77.4 (SD6.3) dBA while their most prominent frequencies were 3880, 7997, and 3513 Hz, respectively. Three of the subjects had slightly more than 20 dB hearing loss at 4 kHz on audiogram; all were affected unilaterally. These three individuals worked as dental nurses for 11, 13, and 21 years, respectively. Therefore, the prevalence of noise induced hearing loss was 5.0% (95% CI: -1.0%, 10.0%). CONCLUSIONS: Dental staff nurses might have an increased risk of noise induced hearing loss, depending upon individual factors influencing susceptibility and duration of noise exposure.

Anti-nociceptive and anti-inflammatory properties of Caralluma arabica.

In the present study, a 10% ethanolic extract of Caralluma arabica at the doses of 200 and 400 mg/kg was evaluated for the antinociceptive activity using the hot plate and acetic acid induced abdominal constrictions in mice and tail flick method in rats. Oral and topical application of C. arabica extract was assessed in the present study for anti-inflammatory properties using carrageenan-induced rat paw oedema. Anti-inflammatory activity was also evaluated using cotton pellet granuloma method. C. arabica extract showed significant Anti-nociceptive properties in all the models studied. C. arabica extract significantly reduced the increase in hind paw volume induced by carrageenan injection when used orally or topically. Results of the present study confirm the use of C. arabica traditionally for the treatment of painful and inflammatory conditions and indicate transdermal absorption of the plant extract.

Neuropharmacological actions of Portulaca oleraceae L v. sativa (Hawk).

Portulaca oleracea L v. sativa (family: Portulacaceae) is a warm-climate annual, cultivated in the Arabian peninsula and used traditionally for alleviating pain and swelling. It was observed that a 10% ethanolic extract of this plant produced restriction of movement in animals during the routine screening studies. Therefore the effects of the extract on the locomotor activity, threshold to noxious stimulus, anti-convulsant activity and relaxant effects on the skeletal muscle were studied. The extract, on intraperitoneal administration, showed a significant reduction in the locomotor activity in mice, anti-nociceptive activity in rats using Tail Flick Method, an increase in the onset time of pentylenetetrazole-induced convulsions in mice and muscle relaxant activity in in vitro (rat hemidiaphragm) and in vivo (grip strength) experiments. The anti-nociceptive activity of the extract in rats was attenuated by naloxone pre-treatment indicating the involvement of opioid receptors in its anti-nociceptive effects. It is indicated from the results of the present study that P. oleracea v. sativa possesses varied effects on both the central and peripheral nervous system and the plant should be exhaustively studied for other neuropharmacological effects.

Anti-inflammatory and anti-ulcer activity of Calligonum comosum in rats.

The 10% ethanol extract of the aerial parts of Calligonum comosum (50--400 mg/kg, i.p.) significantly reduced the increase in hind paw oedema induced by carrageenan in rats. Following sub-acute oral administration of the extract (50 and 100 mg/kg, daily for 14 days), a significant anti-inflammatory activity in the cotton pellet model was observed. Pre-treatment with the extract (100, 200 and 400 mg/kg) produced a significant and dose-dependent inhibition to the acute gastric ulcers induced by phenylbutazone, indomethacin, 0.2 N NaOH and 80% ethanol.

The analgesic and anti-inflammatory effects of Portulaca oleracea L. subsp. Sativa (Haw.) Celak.

Many ethnic groups have used different species of Portulaca oleracea L., a member of the Family Portulacaceae, as vegetable and also herbal medicine against several diseases for many centuries. A review of the records in both folkloric and scientific literature indicates that Portulaca has many medicinal uses. After our previous preliminary screening of three species of the family for analgesic and anti-inflammatory properties, Portulaca oleracea L. subsp. sativa (Haw.) Celak. (a cultivar) was chosen for further work due to its abundant availability from reliable sources. The 10% ethanolic extract of the aerial parts (dried leaves and stem) showed significant anti-inflammatory and analgesic after intraperitoneal and topical but not oral administration when compared with the synthetic drug, diclofenac sodium as the active control. Results indicate this cultivar species of Portulaca also possesses some of the claimed traditional uses of the wild species in the relief of pain and inflammation.

Effect of some free radical scavengers on reperfusion induced arrhythmias in the isolated rat heart.

The possible role of oxygen free radicals in the development of reperfusion arrhythmias was investigated using a 10-min period of coronary ligation followed by reperfusion in the isolated rat heart. Superoxide dismutase (5 to 20 u/ml) glutathione (10(-5) to 10(3)M) and ascorbic acid (10(-4) to 5 X 10(-4) M) when given before coronary ligation attenuated the development of reperfusion arrhythmias. Mannitol (2 X 10(-2)M) and catalase (100 and 300 u/ml) did not have any significant effect on reperfusion arrhythmias when given alone but they did potentiate the antiarrhythmic effect of superoxide dismutase. Glutathione, and a combination of superoxide dismutase, catalase and mannitol also reduced the incidence of reperfusion induced ventricular fibrillation when given just before reperfusion. By perfusing hearts with ferricytochrome C it was possible to show an increased reduction of ferricytochrome C during the first minute of reperfusion which could be prevented by the addition of superoxide dismutase. These results provide evidence that oxygen free radicals are produced and may be important in the genesis of reperfusion induced arrhythmias in the isolated rat heart.