METHODS: This is a prospective cross-sectional study conducted at the University Malaya Medical Centre. A total of 30 patients who have undergone total laryngectomy were assessed objectively using the Sniffin' Sticks test and compared against normal age-matched Malaysians. Subsequently, they also filled out the modified Questionnaire on Olfactory Disorders. Correlations of patient demographics, disease and treatment variables against olfactory outcomes were conducted.
RESULTS: All subjects suffered olfactory impairment, with 66.7% of them being anosmic after total laryngectomy. The Sniffin' Sticks test demonstrated a statistically significant difference between laryngectomees and the normal age-matched Malaysian population in all three subtests for odor threshold, discrimination and identification. 37% of patients developed olfactory adaptive methods, which resulted in higher olfactory scores and a better quality of life. There were no patient demographics, disease or treatment variables associated with a poorer olfactory outcome identified.
CONCLUSION: Olfactory impairment should not be overlooked among patients after total laryngectomy. Although as many as a third of patients developed some sort of olfactory adaptive behavior, early rehabilitation should be integrated into the multidisciplinary rehabilitation program after total laryngectomy.
METHOD: This study included a total of 44 participants without subjective olfactory disturbances. Lavender and normal saline were used as the olfactory stimulant and control. Electroencephalogram was recorded and power spectra were analysed by the spectral analysis for each alpha, beta, delta, theta and gamma bandwidth frequency upon exposure to lavender and normal saline independently.
RESULTS: The oscillatory brain activities in response to the olfactory stimulant indicated that the lavender smell decreased the beta activity in the left frontal (F7 electrode) and central region (C3 electrode) with a reduction in the gamma activity in the right parietal region (P4 electrode) (p < 0.05).
CONCLUSION: Olfactory stimulants result in changes of electrical brain activities in different brain regions, as evidenced by the topographical brain map and spectra analysis of each brain wave.
RESULTS: Inulin decreased (P < 0.05) the average daily enteric H2 S and CH3 SH production by 12.4 and 12.1% respectively. The concentrations of acetate, propionate and butyrate in the large intestinal content were significantly increased (P < 0.05) with inulin treatment, whereas valerate concentration and MGL mRNA expression decreased (P < 0.05). The growth of Lactobacillus, Butyrivibrio, Pseudobutyrivibrio, Bifidobacterium and Clostridium butyricum was stimulated, while that of Desulfovibrio, the dominant SRB, was inhibited, and there was an accumulation of SO42- in the large intestinal content of the inulin-supplemented pigs, suggesting that inulin mitigates H2 S generation from the SO42- reduction pathway by reducing the growth of SRB.
CONCLUSION: The results showed that inulin mitigates CH3 SH generation via three methionine degradation metabolic pathways and H2 S generation from two cysteine degradation metabolic pathways, thus resulting in increased synthesis of these two sulfur-containing amino acids in the pig large intestine. © 2016 Society of Chemical Industry.
RESULTS: Thirty Hy-Line Gray and thirty Lohmann Pink laying hens were used in this study to determine the impact of cecal microbial structure on odor production of laying hens. The hens were managed under the same husbandry and dietary regimes. Results of in vivo experiments showed a lower hydrogen sulfide (H2S) production from Hy-Line hens and a lower concentration of soluble sulfide (S2-) but a higher concentration of butyrate in the cecal content of the Hy-Line hens compared to Lohmann Pink hens (P 0.05). Significant microbial structural differences existed between the two breed groups. The relative abundance of some butyrate producers (including Butyricicoccus, Butyricimonas and Roseburia) and sulfate-reducing bacteria (including Mailhella and Lawsonia) were found to be significantly correlated with odor production and were shown to be different in the 16S rRNA and PCR data between two breed groups. Furthermore, some bacterial metabolism pathways associated with energy extraction and carbohydrate utilization (oxidative phosphorylation, pyruvate metabolism, energy metabolism, two component system and secretion system) were overrepresented in the Hy-Line hens, while several amino acid metabolism-associated pathways (amino acid related enzymes, arginine and proline metabolism, and alanine-aspartate and glutamate metabolism) were more prevalent in the Lohmann hens.
CONCLUSION: The results of this study suggest that genotype of laying hens influence cecal microbiota, which in turn modulates their odor production. Our study provides references for breeding and enteric manipulation for defined microbiota to reduce odor gas emission.
METHODS: This was a cross-sectional study, conducted at Otorhinolaryngology outpatient clinic of Universiti Kebangsaan Malaysia Medical Centre, Secondary Science School, and Children Learning Centre in Kuala Lumpur, Malaysia, from August 2019 until December 2021.
RESULTS: In 450 healthy participants, the cut-off points of the threshold discrimination identification (TDI) scores at the 10th percentile for olfactory abilities were 19 in children, 30.1 in adolescents, 32.1 in young adults, 31.1 in middle-aged adults, and 28.6 in older adults. The children had significantly lower olfactory abilities, with the Bonferroni post-hoc tests of p<0.001. The young adults had higher olfactory abilities than older adults (p<0.05). The results showed that the identification score was highest in middle-aged adults (p<0.001). The discrimination score was the highest in young adults (p<0.001). The best odor threshold performance was observed in adolescents (p<0.001). The TDI score showed a significant difference in olfactory abilities between men and women (p=0.001).
CONCLUSION: Using a culturally adapted smell test, our population was able to identify, discriminate, and perceive odorants better than the European population. This data will help clinicians and researchers with a tool to reliably establish the correct results of olfactory function in our population. Women had better olfactory abilities than men.