Prevalence of olfactory dysfunction in D614G, alpha, delta and omicron waves: a psychophysical case-control study.

BACKGROUND: The purpose of this study was to compare the prevalence of olfactory dysfunction (OD) at different stages of the COVID-19 pandemic by evaluating subjects diagnosed with SARS-CoV-2 infection during the Omicron wave with psychophysical tests and comparing the results with those obtained from patients infected during the D614G, Alpha and Delta waves and with those of a control group. METHODOLOGY: The study included adult patients diagnosed with SARS-CoV-2 infection. Depending on the time of diagnosis, the subjects were divided into four study groups: D614G; Alpha, Delta and Omicron variant groups. A group of uninfected individuals was used as control. All subjects underwent psychophysical evaluation of the olfactory function with the Connecticut Chemosensory Clinical Research Center olfactory test (D614G and Alpha groups) or the extended version of the Sniffin'Sticks test (Delta, Omicron and control groups). RESULTS: 372 cases (134 D614G group, 118 Alpha group, 32 in Delta group and 88 Omicron group) were recruited and evaluated within 10 days of infection, alongside 80 controls. Patients self-reported olfactory loss in 72.4% of cases in the D614G group, in 75.4% of cases in the Alpha group, in 65.6% of cases in the Delta group and in 18.1% in the Omicron group. Psychophysical evaluation revealed a prevalence of OD: 80.6%, 83.0%, 65.6% and 36.3% in the D614G, Alpha, Delta and Omicron group respectively. The differences between the D614G, Alpha and Delta groups were not statistically significant. The Omicron group demonstrated a significantly lower prevalence of OD than the other variants but still significantly higher than the controls. CONCLUSIONS: During the Omicron wave OD was less prevalent than during the D614G, Alpha and Delta periods. One-third of patients have reduced olfactory function on psychophysical evaluation during the Omicron wave. Our results should be considered with caution as the VOC has not been determined with certainty.

Platelet-rich plasma uterine infusion and pregnancy rate in barren mares with chronic degenerative endometritis.

The chronic degenerative endometritis (CDE) is recognised as directly related to age and infertility in the mare. In this study, the 14 days post ovulation (PO) pregnancy rate was assessed in 60 barren mares affected by CDE, submitted to platelet-rich-plasma intrauterine infusion (PRPI) 24 hours PO. Data showed a significant positive effect of PRPI on the chance to become pregnant in mares affected by Kenney I-II CDE. The overall 14 days PO pregnancy rate was 75%. Sixty-nine % of the overall pregnancies was achieved with the 1st PRPI, but an additional 31% was obtained with the 2nd PRPI at the subsequent heat, increasing significantly the number of pregnancies. Although the 1st PRPI lead to a higher pregnancy rate than the 2nd PRPI (52 vs 23%), the repetition of the treatment had a significant positive effect on the overall pregnancies. Mare's young age positively influenced the chance to become pregnant and was associated to endometritis Kenney I. Mares with endometritis Kenney I had better chance to become pregnant than those with endometritis Kenney II. The PRPI proved, therefore, to be beneficial in barren mares with CDE, and resulted in high overall pregnancy rate achievement in barren mares.

Evaluation of the Sealing Capability of the Implant Healing Screw by Using Real Time Volatile Organic Compounds Analysis: Internal Hexagon Versus Cone Morse.

BACKGROUND: Implant sealing capability is a crucial issue in assessment of implant success and peri-implant marginal bone loss. Clinical studies demonstrated presence of viable bacteria in the internal part of functioning implants during tissue healing. For this study, a volatile organic compounds (VOCs) emission test was developed to evaluate the existing "seal" between implant and healing screw. Two kinds of implant-screw connection were compared: 1) internal hexagon; and 2) cone Morse. METHODS: Fifteen patients were enrolled in the study, three males and 12 females, who required fixed prosthetic rehabilitation. A total of 37 implants was placed, 23 with a cone Morse taper internal connection and 14 with a screw-retained internal hexagon abutment. VOCs real-time measures were performed in the implant site immediately after removing the healing screw. RESULTS: Statistical analysis was carried out. Results showed VOCs maximum peak amplitude in cone Morse versus internal hexagon showed significant difference (P <0.001), whereas VOCs time to peak showed no significant difference (P = 0.7). CONCLUSIONS: Use of the new methodology for the VOCs emission test may lead to important new data for understanding how the "failed" attachment of implant components, in two-part assemblies, may contribute to implant losses. In particular, study results support the hypothesis that the microgap of the implant-screw healing junction could cause differences in bacterial penetration. VOCs emission test evaluation represents a new diagnostic tool with an effective approach to quickly analyze, in real time, sealing capability of dental implants with healing screw interfaces.

Influence of Sensory Stimulation on Exhaled Volatile Organic Compounds.

The real-time exhaled volatile organic compounds (VOCs) have been suggested as a new biomarker to detect and monitor physiological processes in the respiratory system. The VOCs profile in exhaled breath reflects the biochemical alterations related to metabolic changes, organ failure, and neuronal activity, which are, at least in part, transmitted via the lungs to the alveolar exhaled breath. Breath analysis has been applied to investigate cancer, lung failure, and neurodegenerative diseases. There are by far no studies on the real-time monitoring of VOCs in sensory stimulation in healthy subjects. Therefore, in this study we investigated the breath parameters and exhaled VOCs in humans during sensory stimulation: smell, hearing, sight, and touch. Responses sensory stimulations were recorded in 12 volunteers using an iAQ-2000 sensor. We found significant effects of sensory stimulation. In particular, olfactory stimulation was the most effective stimulus that elicited the greatest VOCs variations in the exhaled breath. Since the olfactory pathway is distinctly driven by the hypothalamic and limbic circuitry, while other senses project first to the thalamic area and then re-project to other brain areas, the findings suggest the importance of olfaction and chemoreception in the regulation lung gas exchange. VOCs variations during sensory activation may become putative indicators of neural activity.

Hypoxic Ventilatory Reactivity in Experimental Diabetes.

Diabetes, apart from generalized neuropathy and microangiopathy, involves tissue hypoxia, which may drive chronic proinflammatory state. However, studies on the ventilatory control in diabetes are sparse and conflicting. In this study we examined the function and morphology of diabetic carotid bodies (CBs). Diabetes was evoked in Wistar rats with streptozotocin (70 mg/kg, i.p.). The acute hypoxic ventilatory responses (HVR) to 12 and 8 % O(2) were investigated in conscious untreated rats after 2 and 4 weeks in a plethysmographic chamber. CBs were dissected and subjected to morphologic investigations: (1) electron transmission microscopy for ultrastructure and (2) laser scanning confocal microscopy to visualize the microvascular bed in sections labeled with the lectin Griffonia simplicifolia-I (GSI), an endothelial cell marker, and fluorescein isothiocyanate (FITC). All findings were referenced to the normal healthy rats. We found that diabetes distinctly dampened the HVR. At the ultrastructural level, the diabetic CB displayed proliferation of connective tissue and neovascularization deranging the interglomal structure, and lengthening the O(2) diffusion path from capillaries to chemoreceptor cells. The chemoreceptor cells remained largely unchanged. The endothelial cell labeling confirmed the intensive angiopathy and the induction of microvessel growth. We conclude that diabetes hampers the chemical regulation of ventilation due to remodeling of CB parenchyma, which may facilitate chronic hypoxia and inflammation in the organ.

Adaptation of olfactory threshold at high altitude.

The aim of this study was to investigate the effects of the extreme environment of high altitude hypoxia on olfactory threshold. The study was conducted before, during, and after a scientific expedition to Mera Peak (5,800 m). The n-butanol test was used for the assessment of the magnitude of the olfactory threshold. The finding was that the olfactory threshold dramatically increased at high altitude. We conclude that there is a physiological adaptation of olfaction due to altitude-hypoxia.

Reduced pulmonary function is age-dependent in the rat lung in normoxia.

BACKGROUND: Oxygen transport is optimized at the cellular level, since oxygen serves as the terminal electron acceptor in mitochondrial oxidative phosphorylation and several enzymatic processes require molecular oxygen as substrate. During development and aging, redundant cells and exhausted cells are eliminated, respectively, whereas others can adapt to the stressful environment and survive. OBJECTIVE: The study investigated the molecular mechanisms activated in the lung during normal aging, through the expression of hypoxia inducible factor (HIF), vascular endothelial growth factor (VEGF), p53, p66⊃Shc, putative cysteine protease (CPP32) and kinaseB-α phosphorylation (pIkB-α). MATERIAL AND METHODS: Twelve male Wistar rats divided into two age-groups, each consisting of 6 animals, 3 and 24 months old, were used. The rats were anesthetized with Nembutal (40 mg/kg, ip) and the lungs were excised from each rat and processed for TUNEL and Western blotting analyses. RESULTS: The expressions of p53, p66⊃Shc and CPP32 were significantly increased in the old normoxic rat lung specimens, when compared with the young ones. In parallel, expressions of VEGF and pIkBα were increased in old rather than young rats. CONCLUSIONS: Aging leads to increased expressions of p53, p66⊃Shc and CPP32, suggesting that apoptosis is in progress. At the same time, the lung tries to counteract apoptosis through the production of VEGF and pIkB-α to adapt itself to a stressful situation. The aging lung creates a life-support system in order to counteract the apoptotic process.

Absence of bioactivity of lipid derivatives of serotonin.

BACKGROUND: Serotonin (5-HT) and its receptors are present in central, the brain stem, and peripheral, the carotid body, tissues controlling the ventilatory responses to hypoxia. The exact action of serotonin and its nature are, however, unsettled. We hypothesized that the discrepant results on the ventilatory action of serotonin could be caused by the inability of serotonin to penetrate into the brain or the plasma membrane lipid bilayers, the target site of signal transduction cascades, after its exogenous administration. OBJECTIVE: To study the penetrability of novel lipid derivatives of serotonin of varying fatty acid chain length and number of saturated/unsaturated bonds, the oleic, caprylic, and caprolic amides of 5-HT, into the brain, and their functional effects on the hypoxic ventilatory response in awake rats after systemic administration. MATERIAL AND METHODS: Adult Wistar rats were used for the experiments. In the biochemical part of the study, the presence and stability of the compounds tested, after i.p. injection, was assessed in brain extracts using spectrophotometry and thin-layered chromatography. In the functional part, the ventilatory responses to 8 and 12% hypoxia were compared before and 1 h after the compound administration using a whole body plethysmography. RESULTS: The "lipidized" serotonin compounds turned out to be stable in brain extracts in vitro for up to 3 h of the test. However, we could not substantiate the presence of any of the compounds in the brain, with either method used, after i.p. administration. Likewise, none of the compounds had any appreciable effect on the profile of the stimulatory hypoxic ventilatory response. CONCLUSIONS: Synthetically attaching lipophilic groups to the serotonin molecule does not make it penetrate into the brain. The lack of serotonin penetrability likely depends on the planarity of its molecule, as it does not seem to depend on the size, number of carbons or bond saturation of the "lipidized" molecules. Such molecules do not directly interfere with the carotid chemoreceptor-mediated hypoxic ventilatory response. The study failed to substantiate the bioactive potential of the lipid derivatives of serotonin.

Voltage-activated current properties of male and female mouse vomeronasal sensory neurons: sexually dichotomous?

The vomeronasal organ, the chemosensory organ of the vomeronasal system, is vital in determining sexual and gender-specific behavior in mice. Here, whole-cell voltage-activated currents of individual mouse vomeronasal sensory neurons of two strains (BALB/c and CBA) were measured and correlated to sex in each strain. The average resting membrane potentials, maximal outward current magnitudes, and kinetics of activation and inactivation, were found to be independent of sex. Maximal inward current magnitudes differed significantly across gender in CBA, whereas they did not significantly differ in male and female BALB/c mice: BALB/c males -347+/-45 pA ( n=51), and females -430+/-56 pA ( n=27); CBA males -308+/-36 pA ( n=56) and females -155+/-18 pA ( n=28). These results suggest that some voltage-activated properties may differ slightly according to gender and to strain.

A comparative morphometric analysis of the optic nerve in two cetacean species, the striped dolphin (Stenella coeruleoalba) and fin whale (Balaenoptera physalus).

A comparative study was made on one Mysticete (the fin whale, Balaenoptera physalus) and one Odontocete species (the striped dolphin, Stenella coeruleoalba) by measuring several morphological characteristics seen in cross sections of the optic nerve. We found that the two cetacean nerves share a number of specializations that distinguish them from the optic nerve of terrestrial mammals. Fiber density is approximately two-fold lower than in land mammals. A corresponding increase in the cross-sectional area occupied by astrocytes is observed. A population of "giant" (up to 15 microm in diameter) optic axons is present in both the B. physalus and the S. coeruleoalba nerve. It is argued that these features probably reflect common adaptations to the constraints imposed by the aquatic environment. "Giant" optic axons might ensure short-latency detection of preys and other targets during navigation while the increased astroglial content might be related to the maintenance of neuronal function during periods of anaerobic metabolism under water.