Although it is accepted that progesterone (P) induces acrosome reaction through non-genomic regulation, it is not well known if P also affects hyperactivation of sperm. Hamster spermatozoa were hyperactivated by incubation for 4 h on modified Tyrode's albumin lactate pyruvate medium and recorded on a DVD via a charge-coupled device camera attached to a microscope with phase-contrast illumination and a small CO incubator. Phosphorylation of proteins was detected by western blotting using antiphosphotyrosine antibodies. Sperm hyperactivation was significantly increased and accelerated by a non-genomic signal of P. Although acceleration of motility of hyperactivated sperm occurred with 10, 20 and 40 ng/mL P, the most effective concentration was 20 ng/mL. Progesterone also significantly increased 80-kDa tyrosine phosphorylation of sperm proteins. Both extracellular Ca and albumin were essential for sperm hyperactivation, and the former was also essential for maintaining sperm flagellar movement. Moreover, phospholipase C (PLC) was associated with the regulation of hyperactivation by P. It is likely that P regulates sperm hyperactivation by a non-genomic signal in relation to tyrosine phosphorylation and PLC. (Reprod Med Biol 2008;: 63-74).
PurposeOral frailty or the loss of oral functionality can be a symptomatic precursor of overall frailty. Previous studies have suggested that decreased tongue pressure causes a decline in ingesting and swallowing function and poor nutrition. This study investigated what factor(s) contribute to tongue pressure, thereby leading to frailty.Patients and methodsFor the purposes of the present study, 467 residents of Hirosaki city in northern Japan aged≥60 years who completed a questionnaire about frailty and underwent an intraoral assessment, which included number of teeth, presence or absence of periodontitis, tongue pressure, and oral diadochokinesis (ODK) were recruited.ResultsOf the 467 participants with complete data sets, frailty was identified in 13 (7.5%) of 173 males and in 34 (11.6%) of 294 females. Significantly fewer teeth, lower tongue pressure, and a reduced diadochokinetic syllable rate were more prevalent among frail than among healthy residents. Multivariable logistic regression analysis revealed that age, body mass index, number of teeth, and tongue pressure significantly contributed to frailty, whereas ODK did not. Multiple regression analysis showed that tongue pressure was positively associated with muscle index and number of teeth.ConclusionThe results of the present study suggest that fewer teeth and lower tongue pressure, but not ODK function, are risk factors for developing overall frailty among older residents.
PurposePrevention, early detection and effective rehabilitation of dysphagia are important issues to be considered in an aging society. Previous studies have shown conflicting findings regarding the association between dysphagia and its potential risk factors, including age, malnutrition, oral conditions, lifestyle and medical history. Herein, we assessed the prevalence and association of dysphagia with potential risk factors in 50- to 79-year-old adults dwelling in a community in Japan.Patients and methodsIn this study, there were 532 participants (185 males and 347 females). Participants who responded positively to the question “Do you sometimes choke on drinks/food such as tea and soup?” or those who presented with abnormal repetitive saliva swallowing test findings were diagnosed with dysphagia. The data collected from these participants included the following: number of teeth, occurrence of oral dryness, age, body mass index, serum albumin concentration, smoking, drinking and exercise habits, presence of diseases, such as diabetes mellitus and hypertension, and questions from the Mini–Mental State Examination.ResultsDysphagia was observed in 33 males (17.8%) and 76 females (21.9%). To explore the effect of the potential risk factors on the prevalence of dysphagia, a model was built by multivariate logistic regression analysis. Using the forced entry method, oral dryness (odds ratio [OR] =3.683 and P=0.003 in males; OR =1.797 and P=0.032 in females) and the number of teeth (OR =0.946 and P=0.038 in males) were found to be significantly related to dysphagia.ConclusionThis cross-sectional study demonstrated associations between oral conditions and dysphagia. Factors such as oral dryness and number of teeth may contribute to dysphagia more so than aging, lifestyle and comorbidity in community-dwelling adults over the age of 50.
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