头颈部放射治疗对味觉的损害

放射线治疗是恶性肿瘤的常用治疗手段之一。头颈部放射治疗常引起局部疼痛、口干、味觉障碍等一系列并发症，可不同程度地影响到病人的生活质量以及对治疗的耐受性。近年来，对头颈部放射治疗并发症的研究已引起临床重视。灵敏的味觉是维持良好生活质量的重要条件之一。味觉障碍既是一种客观症状，也是一种主观感受，它不仅直接抑制病人的食欲，导致营养缺失，更可加重其身心负担。本文对头颈部放疗引起味觉损害的相关研究作一综述，侧重介绍味觉损害的发生机制、临床表现、治疗及预防等方面的新进展。     

Examining the effects of lipopolysaccharide and cholecystokinin on water ingestion: comparing intake and palatability

Lipopolysaccharide (LPS) and cholecystokinin (CCK) have been shown to have anorectic properties in a variety of species. The present study examined the effects of LPS and CCK, both alone and in combination, on two different aspects of water ingestion, water intake and palatability. On test days, animals were first injected intraperitoneally (i.p.) with either LPS (200 microg/kg) or NaCl vehicle, and 2 h later received a second injection of either CCK (8 microg/kg) or NaCl vehicle. In Experiment 1, water intake was monitored for 1 h on 3 separate test days 72 h apart; while in Experiment 2, water palatability was assessed using the taste reactivity test (TRT), on two separate test days 72 h apart. Both LPS and CCK significantly (p<0.05) reduced water intake, with the effects of combined LPS with CCK being more pronounced than either agent injected alone. Rats developed a rapid tolerance to the effects of LPS on water intake on subsequent exposures to LPS. Results from the TRT indicated that LPS enhanced water palatability (p<0.05), as evidenced by a high level of ingestive responding, whereas CCK produced a pattern of responding indicative of satiety. LPS plus CCK reduced ingestive responding on the first test day, but these responses were significantly increased on the second test day (p<0.05). These results demonstrate that although LPS reduces water intake, it enhances water palatability. The results further underscore the necessity for examining palatability changes in addition to intake measures when studying the regulation of feeding and drinking.     

The hedonic impact and intake of food are increased by midazolam microinjection in the parabrachial nucleus

Benzodiazepines have been reported to induce eating when administered into the brainstem of rats (either the fourth ventricle or the parabrachial nucleus). Benzodiazepines in the brainstem also have been reported to enhance the hedonic impact of taste, as measured by hedonic/aversive taste reactivity patterns, when administered to the fourth ventricle. The present study examined whether the parabrachial nucleus in particular is a brainstem site of the benzodiazepine-produced enhancement of eating and palatability. Food intake (cereal mash) was measured after brainstem microinjections of midazolam or vehicle (0.0, 7.5, and 15.0 microg) into the parabrachial nucleus, the nucleus of the solitary tract, the pedunculopontine tegmental nucleus, or the fourth ventricle (60 microg). We used the taste reactivity paradigm to measure hedonic/aversive affective reactions elicited from rats by oral infusions of a bittersweet solution (7% sucrose-0.01% quinine). Positive hedonic reactions and negative aversive reactions to sucrose-quinine were also measured after microinjections of midazolam (0.0, 7.5, and 15 microg) into the parabrachial nucleus. Midazolam increased food intake and selectively enhanced positive hedonic taste reactivity patterns to the bittersweet solution when microinjections were delivered to the parabrachial nucleus. When administered to the other brainstem sites at the same doses, however, midazolam had no effect. We therefore conclude that the parabrachial nucleus can mediate the benzodiazepine-induced enhancement of the hedonic impact of taste as well as mediating the enhancement of eating behavior.     

The etiologies and considerations of dysgeusia: A review of literature

BackgroundDysgeusia is a prevalent qualitative gustatory impairment that may affect food intake and quality of life. The facial (VII), glossopharyngeal (IX), and vagus (X) nerves are the three cranial nerves responsible for sensing taste. Typically, dysgeusia is considered a general term for all taste disorders. In addition, dysgeusia may be a symptom of underlying systemic conditions such as diabetes mellitus, chronic kidney disease, respiratory infections, and nutritional deficiencies. Various subjective and objective diagnostic approaches are available to aid clinicians, each with its own set of benefits and drawbacks.HighlightsTaste impairment can lead to a lack of enjoyment while eating, food aversion, and malnutrition, resulting in a decrease in the quality of life and loss of muscle mass. Therefore, the present review aims to address the probable etiologies, diagnostic aids, and management of dysgeusia. A broad search for studies was conducted using PubMed, Web of Science, Scopus, and Google Scholar. In addition, relevant studies found in the references of the selected articles were also studied.ConclusionOral health care providers should be aware of the possible etiologies of dysgeusia, diagnostic tools, and treatment options. Accurate diagnosis of the cause of taste dysfunction has a significant impact on the management of taste impairment.     

Theophylline increases saliva sonic hedgehog and improves taste dysfunction

ObjectiveTo determine changes in saliva sonic hedgehog (Shh) and in taste dysfunction before and after oral theophylline treatment.DesignShh was measured in parotid saliva of both normal subjects and patients with taste dysfunction of multiple etiologies by use of a sensitive spectrophotometric ELISA assay. Taste dysfunction was defined clinically by both subjective inhibition of taste function (including acuity loss) and impaired gustometry.ResultsTheophylline treatment increased patient saliva Shh and improved taste dysfunction both subjectively and by gustometry.ConclusionsBy use of these systematic clinical measurements theophylline can be demonstrated to increase saliva Shh and improve taste dysfunction. These results are consistent with saliva Shh acting as a taste bud growth factor which stimulates stem cells of taste buds to initiate development and perpetuation of taste bud receptors. Measurements of saliva Shh provide an important marker for the presence of taste dysfunction and in the improvement by theophylline treatment.     

Taste and olfactory status in a gourmand with a right amygdala lesion

In a patient with a lesion of the right amygdala and temporal pole who had the characteristics of the gourmand syndrome, sensory and hedonic testing was performed to examine the processing of taste, olfactory, and some emotional stimuli. The gourmand syndrome describes a preoccupation with food and a preference for fine eating and is associated with right anterior lesions. It was found that the taste thresholds for sweet, salt, bitter, and sour were normal; that the patient did not dislike the taste of salt (NaCl) at low and moderate concentrations as much as age-matched controls; that this also occurred for monosodium glutamate (MSG); that there were some olfactory differences from normal controls; and that there was a marked reduction in the ability to detect face expressions of disgust.     

木蝴蝶含片的研制

摘 要 目的： 制备木蝴蝶含片。方法: 以木蝴蝶提取物为主药,采用湿法制粒压片法,在单因素考察基础上,以含片外观、口感、崩解时限、硬度为指标,通过正交设计试验对处方进行优化筛选,确定含片的制备处方。以平均重量差异和平均崩解时间为指标,对按照优化的处方工艺制备的3批含片进行质量检查。结果: 优选的处方为：甘露醇50%,甜味剂为蔗糖-甜菊糖苷（100∶1）5%,清凉剂为天然薄荷油5%,粘合剂为聚维酮-K30（PVP-K30）-85%乙醇（6∶10）35%。以筛选的处方工艺制备的3批含片平均重量差异为 (1.83±0.29) %,平均崩解时间为（14.7±0.6）min,均符合药典质控要求。结论: 木蝴蝶含片制备工艺稳定,重复性良好。     

Regional and Chronological Variation of Chemosensory Dysfunction in COVID-19: a Meta-Analysis

BackgroundOlfactory and gustatory dysfunction are frequently reported in patients with coronavirus disease 2019 (COVID-19). However, the reported prevalence of olfactory and/or gustatory dysfunction varies widely, and the reason for the inter-study differences is unclear. Hence, in this meta-analysis, we performed subgroup analyses to investigate the factors that contribute to the inter-study variability in the prevalence of olfactory and gustatory dysfunction.MethodsOut of 943 citations, we included 55 eligible studies with 13,527 patients with COVID-19 for a meta-analysis. Calculating the data extracted from each study, the weighted summary prevalence of olfactory and gustatory dysfunction was estimated using a Freeman-Tukey transformation with models based on random-effects assumptions. A meta-analysis of variance compared the prevalence of olfactory and gustatory dysfunction according to regional, chronological, demographic, and methodologic factors, respectively.ResultsThe overall pooled prevalence rates of olfactory and gustatory dysfunction were 51.4% and 47.5%, respectively, in the random-effect model. In subgroup analyses, the prevalence rates of olfactory and gustatory dysfunction were significantly different among four geographical regions (both P < 0.001, respectively). Although the prevalence rates of olfactory and gustatory dysfunction did not significantly differ according to the time of enrollment, the subgroup analyses including only studies from the same geographical region (Europe) revealed a significant difference in olfactory dysfunction according to the time of enrollment.ConclusionThe regional and chronological differences in the prevalence rates of olfactory and gustatory dysfunctions partly explain the wide inter-study variability.     

Behavioral and neural responses to gustatory stimuli delivered non-contingently through intra-oral cannulas

The act of eating requires a decision by an animal to place food in its mouth. The reasons to eat are varied and include hunger as well as the food's expected reward value. Previous studies of tastant processing in the rat primary gustatory cortex (GC) have used either anesthetized or awake behaving preparations that yield somewhat different results. Here we have developed a new preparation in which we explore the influences of intra-oral and non-contingent tastant delivery on rats' behavior and on their GC neural responses. We recorded single-unit activity in the rat GC during two sequences of tastant deliveries, PRE and POST, which were separated by a waiting period. Six tastants ranging in hedonic value from sucrose to quinine were delivered in the first two protocols called 4TW and L-S. In the third one, the App L-S protocol, only hedonically positive tastants were used. In the 4TW protocol, tastants were delivered in blocks whereas in the two L-S protocols tastants were randomly interleaved. In the 4TW and L-S protocols the probability of ingesting tastants in the PRE sequence decreased exponentially with the trial number. Moreover, in both protocols this decrease was greater in the POST than in the PRE sequence likely because the subjects learned that unpleasant tastants were to be delivered. In the App L-S protocol the decrease in ingestion was markedly slower than in the other protocols, thus supporting the hypothesis that the decrease in appetitive behavior arises from the non-contingent intra-oral delivery of hedonically negative tastants like quinine. Although neuronal responses in the three protocols displayed similar variability levels, significant differences existed between the protocols in the way the variability was partitioned between chemosensory and non-chemosensory neurons. While in the 4TW and L-S protocols the former population displayed more changes than the latter, in the App L-S protocol variability was homogeneously distributed between the two populations. We posit that these tuning changes arise, at least in part, from compounds released upon ingestion, and also from differences in areas of the oral cavity that are bathed as the animals ingest or reject the tastants.     

The Association of Taste with Change in Adiposity-Related Health Measures

The relationship between taste-intensity patterns and 5-year change in adiposity-related health measures was determined. Participants were members of the Beaver Dam Offspring Study, a study of the adult children of participants in the population-based Epidemiology of Hearing Loss Study. There were 1,918 participants (mean baseline age=48.8 years; range=22 to 84 years) with baseline taste (2005 to 2008) and follow-up (2010 to 2013) data. Outcomes included 5-year change in body mass index, waist circumference, blood pressure, non–high-density lipoprotein cholesterol, and glycosylated hemoglobin A1c, and hedonic ratings of specific foods. Cluster analysis with Ward's minimum variance method identified the following 5 patterns of the suprathreshold taste intensities of salt, sweet, sour, and bitter: salt and sweet intensities slightly above population averages, average sour and bitter intensities; salt, sour, and bitter intensities above population average, average sweet intensity; salt, sour, and bitter intensities above population average, sweet intensity substantially above average; all intensities below population averages; and all intensities close to population average. The General Linear Model procedure was used for testing cluster differences in the outcomes. With covariate adjustment, the group with all intensities close to population averages had a significantly lower average increase in body mass index compared with the group with above-average intensities for salt, sour, and bitter (+0.4 vs +0.9), and in glycosylated hemoglobin A1c compared with the group with above-average intensities for all tastes (+0.20% vs +0.34%). Clusters differed in the hedonics of foods representing sweetness and saltiness. The study's findings provide evidence that perceived taste intensity might be related to changes in adiposity-related health.