The effect of smell training on COVID-19 induced smell loss.

OBJECTIVE: while smell training appears to be effective for post viral smell loss, its effectiveness in COVID-19 induced smell loss is currently not well known. Therefore, we aim to investigate the potential effect of smell training on patients with COVID-19 induced smell loss. METHODS: we conducted a case-control study with two comparable cohorts. One of which (n=111) was instructed to perform smell training twice daily for 12 weeks, therapeutical adherence was monitored on a daily schedule, while the other cohort (n=50) did not perform smell training. The Sniffin' Sticks Test (SST) was used to objectify participants' sense of smell at baseline and after 12 weeks, reported as a Threshold, Discrimination, and Identification (TDI) score. We also determined the association between therapeutical adherence and the TDI scores. RESULTS: we found a significant difference in psychophysical smell function between patients with COVID-19 induced smell disorders who performed 12 weeks of smell training and those who did not. Median TDI difference between groups was 2.00 However, there was no association between the therapeutical adherence and olfactory function. CONCLUSION: we discovered a significant moderate difference in psychophysical smell function between patients with COVID-19-induced smell disorders who performed smell training and those who did not, implying a possible advantage of training. However, no relationship was found between therapeutical adherence of smell training and olfactory function.

A follow-up on quantitative and qualitative olfactory dysfunction and other symptoms in patients recovering from COVID-19 smell loss.

BACKGROUND: Sudden smell loss is a specific early symptom of COVID-19, which, prior to the emergence of Omicron, had estimated prevalence of ~40% to 75%. Chemosensory impairments affect physical and mental health, and dietary behavior. Thus, it is critical to understand the rate and time course of smell recovery. The aim of this cohort study was to characterize smell function and recovery up to 11 months post COVID-19 infection. METHODS: This longitudinal survey of individuals suffering COVID-19-related smell loss assessed disease symptoms and gustatory and olfactory function. Participants (n=12,313) who completed an initial survey (S1) about respiratory symptoms, chemosensory function and COVID-19 diagnosis between April and September 2020, were invited to complete a follow-up survey (S2). Between September 2020 and February 2021, 27.5% participants responded (n=3,386), with 1,468 being diagnosed with COVID-19 and suffering co-occurring smell and taste loss at the beginning of their illness. RESULTS: At follow-up (median time since COVID-19 onset ~200 days), ~60% of women and ~48% of men reported less than 80% of their pre-illness smell ability. Taste typically recovered faster than smell, and taste loss rarely persisted if smell recovered. Prevalence of parosmia and phantosmia was ~10% of participants in S1 and increased substantially in S2: ~47% for parosmia and ~25% for phantosmia. Persistent smell impairment was associated with more symptoms overall, suggesting it may be a key marker of long-COVID illness. The ability to smell during COVID-19 was rated slightly lower by those who did not eventually recover their pre-illness ability to smell at S2. CONCLUSIONS: While smell ability improves for many individuals who lost it during acute COVID-19, the prevalence of parosmia and phantosmia increases substantially over time. Olfactory dysfunction is associated with broader persistent symptoms of COVID-19, and may last for many months following acute COVID-19. Taste loss in the absence of smell loss is rare. Persistent qualitative smell symptoms are emerging as common long-term sequelae; more research into treatment options is strongly warranted given that even conservative estimates suggest millions of individuals may experience parosmia following COVID-19. Healthcare providers worldwide need to be prepared to treat post COVID-19 secondary effects on physical and mental health.

Investigating morphological changes in the brain in relation to etiology and duration of olfactory dysfunction with voxel-based morphometry.

Olfactory loss (OL) affects up to 20% of the general population and is related to changes in olfaction-related brain regions. This study investigated the effect of etiology and duration of OL on gray matter volume (GMV) of these regions in 257 patients. Voxel-based morphometry was applied to measure GMV in brain regions of interest to test the effects of etiology and duration on regional GMV and the relation between olfactory function and regional GMV. Etiology of OL had a significant effect on GMV in clusters representing the gyrus rectus and orbitofrontal cortex (OFC), bilaterally. Patients with congenital anosmia had reduced GMV in the gyrus rectus and an increased OFC volume compared to patients with acquired OL. There was a significant association between volume of the left OFC and olfactory function. This implies that changes in GMV in patients with acquired OL are mainly reflected in the OFC and depend on olfactory function. Morphology of olfactory areas in the brain therefore seems to relate to olfactory function and the subsequent degree of exposure to olfactory input in patients with acquired OL. Differences in GMV in congenital anosmia are most likely due to the fact that patients were never able to smell.

Chemosensory perception and food preferences in colorectal cancer patients undergoing adjuvant chemotherapy.

BACKGROUND AND AIM: Cancer is one of the major public health problems, with colorectal cancer being one of the most occurring types of cancer. During treatment, patients may experience changes in their dietary intake due to side-effects of treatment, like changes in chemosensory perception, i.e. smell and taste function. This study investigated alterations in chemosensory perception and food preferences in colorectal cancer patients during and after adjuvant chemotherapy. METHODS: Objective olfactory and gustatory function were measured by the Sniffin' Sticks and the Taste Strips test. Subjective smell and taste perception were determined with a questionnaire, while food preferences were assessed with a computer-based ranking task. To investigate changes during chemotherapy, patients undergoing adjuvant chemotherapy were measured before the start, halfway through (approximately 3 months after the start of adjuvant chemotherapy), and within one month after finishing chemotherapy (longitudinal measurements, n = 15 patients). As a comparison group, colorectal cancer patients not undergoing chemotherapy (n = 20), underwent the same measurements at similar time points. To measure changes after treatment, chemosensory perception and food preferences of patients who had undergone chemotherapy treatment were measured once, either at 6, 12 or 24 months after diagnosis (cross-sectional measurements; n = 20 for all time points). Changes during treatment were assessed using linear mixed model analyses, and changes after treatment were assessed with a one-way ANOVA or a Kruskal Wallis test. RESULTS: Objective olfactory and gustatory function did not differ statistically significantly between any of the groups and at any time point during or after treatment (all p > 0.05). In contrast, subjective smell (F(1,84) = 8.17, p = 0.005) and taste (F(1,99) = 4.08, p = 0.046) perception were rated statistically significantly lower by patients undergoing chemotherapy than the comparison group during treatment. At 6 months after diagnosis, patients who underwent chemotherapy rated their subjective taste perception significantly lower than patients at 12 and 24 months after treatment (F(2,57) = 12.05, p = 0.002). Food preferences did not change during treatment, or thereafter (all p > 0.05). Preference for protein-rich foods was positively correlated with objective gustatory function (r = 0.36, p < 0.001), while the preference for low-energy foods showed a negative correlation with objective gustatory function (r = -0.28, p = 0.004). CONCLUSIONS: Similar to other cancer patient populations, mainly subjective smell and taste perception are affected in colorectal cancer patients undergoing adjuvant chemotherapy. Changes in objective olfactory and gustatory function in relation to chemotherapy were not detected by the tests used in our study nor did food preferences change. However, it should be noted that subjective changes in smell and taste perception can affect subsequent flavor perception and food enjoyment, which might negatively impact eating behavior and nutritional intake.

How to quench your thirst. The effect of water-based products varying in temperature and texture, flavour, and sugar content on thirst.

The sensation of thirst plays an important role in the consumption of water or other fluids to rehydrate the body in order to keep bodily functions working properly. An increase in saliva secretion, wetting the mouth by ingestion of liquids, and cooling and sour components in products can alleviate this sensation already before absorption of fluids by the body. This study aimed to investigate the thirst-quenching ability of water-based products differing in temperature and texture (cold solids and cool liquids), flavour (flavoured and non-flavoured) and sugar content in two consecutive experiments. The first experiment tested four products of 10ml each (flavoured popsicles, flavoured beverages, ice cubes, and water). 45 healthy, thirsty participants (8 men and 37 women, mean age 25.7years SD±6.6) were randomly assigned to a flavour group representing the flavour of the popsicles and beverages: mint, lemon, raspberry. Each flavour group tasted all four products (popsicles, beverages, water, ice cubes) in four sessions on consecutive days. Participants rated their thirst and four attributes (flavour intensity, thirst-quenching, refreshing, saliva stimulating) during 3min of consumption on a 100mm VAS scale and ranked all four products on thirst-quenching ability at the end of the last session. The second experiment was performed similarly (n=61, 6 men and 55 women, mean age 23.5years SD±2.87), but used sugar-reduced popsicles to compare to the regular popsicles from the first experiment. In addition, saliva was collected before and after consumption. In the first experiment, cold solid (55.8±0.99) and flavoured (55.9±0.95) products were found to be more thirst-quenching than cool liquid (52.8±0.96) and non-flavoured products (52.8±0.96). The second experiment confirmed that saliva production increased upon consumption of these popsicles, with an increase of saliva weight from 1.7g SD ±0.15 before consumption to 2.0 SD ±0.22 after consumption. Sugar-reduced popsicles were similar in thirst-quenching ability compared to regular popsicles. Overall, cold, solid, flavoured products (such as popsicles) performed best in quenching thirst, and it appeared that sugar-reduction in these products to create healthier alternatives can be achieved without compromising on thirst-quenching abilities. These results can be useful for optimisation of products to alleviate thirst in daily life, as well as in clinical settings for patients where fluid restriction is needed.

[Tasty food for cancer patients: the impact of smell and taste alterations on eating behaviour]. / Smakelijk eten voor patiënten met kanker.

- This article provides an overview of smell and taste changes in cancer patients and the influence of these changes on eating behaviour and food preferences.- Taste changes seem to be more common than alterations in the sense of smell.- The changes in taste and smell are often temporary; smell and taste functions mostly return to their previous level after treatment cessation.- The type of cancer and its treatment influence changes in the sense of smell and taste, making it challenging to give general advice.- Changes in taste and smell - which can lead to modified food preferences and decreased appetite - should be taken into consideration during the treatment of cancer patients to improve the nutritional status and the effectiveness of the treatment.- This requires a personal approach, a multidisciplinary team and validated methods. Moreover, it is important to involve the environment of the patient.

Establishment and characterization of 7 ovarian carcinoma cell lines and one granulosa tumor cell line: growth features and cytogenetics.

The characteristics of 7 newly established ovarian carcinoma cell lines and one granulosa tumor cell line obtained from tumor samples of 7 patients with varying histology of the primary tumor are reported. The cell lines were isolated from 5 serous carcinomas, a mucinous carcinoma, an endometrioid carcinoma and a granulosa cell tumor. All cell lines were passaged at least 25 times and showed stable growth rates. Colony-forming efficiency varied on plastic from 2 to 57% and in agar from 0.01 to 9.30%. The DNA index of the granulosa tumor cell line was diploid, while the ovarian carcinoma cell lines were all aneuploid. In 2 cell lines polyploidisation occurred during culturing. A thorough cytogenetic analysis of 7 cell lines revealed that the granulosa tumor cell line has only minor cytogenetic abnormalities (+5, 22q+). In contrast, the epithelial ovarian-cancer cell lines gave very complex karyotypes with numerous markers and structurally rearranged chromosomes. The chromosomes most often in excess were 15 and 20. Structural rearrangements of chromosomes 1, 3, 7 and 11 were prominent in all ovarian cell lines. In addition, we found changes in chromosomes X, 5, 8 and 13 that have rarely been described before.