OBJECTIVE: To investigate the effect of intraoperative blood salvage autotransfusion on local recurrence and long-term metastasis of patients after carotid body tumor resection. METHODS: We retrospectively reviewed a consecutive series of 61 patients undergoing elective carotid body tumor resection from August 2009 to December 2020. Among them, 14 received intraoperative blood salvage autotransfusion (autotrasfusion group) and 47 did not (non-autotransfusion). Data of general information, surgical status and postoperative follow-up results were collected. RESULTS: The proportion of Shamblin Ⅲ in the autotransfusion group was 85.7%, which was significantly higher than 31.9% in the non-autotransfusion group (P=0.003). The average operation time of the 14 patients in the autotransfusion group was (264±84) min, intraoperative blood loss was 1 200 (700, 2 700) mL, and autologous blood transfusion was 500 (250, 700) mL. Of these, 8 patients (57%) required concomitant allogeneic blood with 400 (260, 400) mL of allogeneic blood. The average operation time of the 47 patients in the non-autotransfusion group was (153±75) min, and the intraoperative blood loss was 300 (100, 400) mL. Of these, 6 (13%) required allogeneic blood transfusion, and 520 (400, 520) mL of allogeneic blood was used. Compared with the non-autotransfusion group, the average operation time in the autologous blood transfusion group was significantly longer (P < 0.001), and the intraoperative blood transfusion volume was larger (P=0.007). Of the 14 patients undergoing autotransfusion, 8 (57%) needed allogeneic blood at the same time; while in the 47 non-autologous transfusion patients, 6 (13%) needed allogeneic blood transfusion. The proportion of autotransfusion group using allogeneic blood at the same time was even higher (P=0.002). The incidence of nerve injury within 30 days after surgery was 29.5%, and there was no significant difference between the two groups. No early deaths occurred. The average follow-up was (76±37) months. One case of local recurrence occurred in the non-autotransfusion group. There was no distant metastasis. There were no tumor-related deaths. The estimated 5-year and 10-year overall survival rates were 96.4% and 83.8%, respectively. There was no significant difference in overall survival between the two groups (P=0.506). CONCLUSION The use of intraoperative blood salvage autotransfusion increased no risk of local recurrence and distant metastasis in patients with carotid body tumor, which is safe and effective in carotid body tumor resection.
Humans ; Blood Transfusion, Autologous/methods* ; Operative Blood Salvage/methods* ; Retrospective Studies ; Male ; Female ; Carotid Body Tumor/pathology* ; Middle Aged ; Prognosis ; Neoplasm Recurrence, Local ; Blood Loss, Surgical ; Aged ; Adult ; Operative Time

Taste buds relay taste sensory information to the primary taste neurons but depend on those same neurons for essential components to maintain function. While denervation-induced taste bud degeneration and subsequent regeneration were discovered decades ago, the mechanisms underlying these phenomena (e.g., heterogenous cellular responses to nerve injury and the signaling pathways involved) remain poorly understood. Here, using mouse genetics, nerve injury models, pharmacologic manipulation, and taste bud organoid models, we identify a specific subpopulation of taste cells, predominantly c-Kit-expressing sweet cells, that exhibit superior resistance to nerve injury. We found the c-Kit inhibitor imatinib selectively reduced the number of residual c-Kit-expressing sweet cells at post-operation week 2, subsequently attenuating the re-emergence of other type II cells by post-operation week 4. In taste bud organoids, c-Kit-expressing cells were resistant to R-spondin withdrawal but susceptible to imatinib, while other taste cell types showed the opposite behavior. We also observed a distinct population of residual taste cells that acquired stem-like properties, generating clonal descendent cells among suprabasal keratinocytes independent of c-Kit signaling. Together, our findings reveal that c-Kit signaling confers resilience on c-Kit-expressing sweet cells and supports the broader reconstruction of taste buds during the later regenerative stage following nerve injury.
Animals ; Taste Buds/metabolism* ; Proto-Oncogene Proteins c-kit/metabolism* ; Mice ; Signal Transduction ; Imatinib Mesylate/pharmacology* ; Mice, Inbred C57BL

The aim of the present study was to explore the role of group II and III metabotropic glutamate receptors (mGluRs) in carotid body plasticity induced by chronic intermittent hypoxia (CIH) in rats. Sprague Dawley (SD) rats were treated with CIH in Oxycycler A84 hypoxic chamber for 4 weeks, and the tail artery blood pressure was measured at the end of model preparation. RT-qPCR was performed to examine the mRNA expression levels of mGluR2/3/8 in rat carotid body. Carotid sinus nerve activity was detected by ex vivo carotid sinus nerve discharge recording technique, and acute intermittent hypoxia (AIH) was administered to induce carotid body sensory long-term facilitation (sLTF), in order to observe the role of group II and group III mGluRs in carotid body plasticity induced by CIH. The results showed that: 1) After 4 weeks of CIH exposure, the blood pressure of rats increased significantly; 2) CIH down-regulated the mRNA levels of mGluR2/3, and up-regulated the mRNA level of mGluR8 in the carotid body; 3) AIH induced sLTF in carotid body of CIH group. In the CIH group, activation of group II mGluRs had no effect on sLTF of carotid body, while activation of group III mGluRs completely inhibited sLTF. These results suggest that CIH increases blood pressure in rats, and group III mGluRs play an inhibitory role in CIH-induced carotid body plasticity in rats.
Rats ; Animals ; Carotid Body/metabolism* ; Rats, Sprague-Dawley ; Hypoxia ; Receptors, Metabotropic Glutamate/metabolism* ; RNA, Messenger/metabolism*

The purpose of this study was to investigate the effect of glutamate and its ionotropic receptor agonists on the response to acute hypoxia in rat carotid body in vitro. Briefly, after SD rats were anesthetized and decapitated, the bilateral carotid bifurcations were rapidly isolated. Then bifurcation was placed into a recording chamber perfused with 95% O₂-5% CO₂ saturated Kreb's solution. The carotid body-sinus nerve complex was dissected, and the carotid sinus nerve discharge was recorded using a suction electrode. To detect the response of carotid body to acute hypoxia, the chamber was perfused with 5% O₂-5% CO₂-90% N₂ saturated Kreb's solution for a period of 100 s at an interval of 15 min. To observe the effect of glutamate, ionotropic α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor agonist AMPA or N-methyl-D-aspartate (NMDA) receptor agonist NMDA on the response to acute hypoxia in rat carotid body, the chamber was perfused with 5% O₂-5% CO₂-90% N₂ saturated Kreb's solution containing the corresponding reagent. The results showed that glutamate (20 μmol/L), AMPA (5 μmol/L) or NMDA (10 μmol/L) inhibited the acute hypoxia-induced enhancement of carotid sinus nerve activity, and these inhibitory effects were dose-dependent. In summary, the activation of glutamate ionotropic receptors appears to exert an inhibitory effect on the response to acute hypoxia in carotid body of rats.
Rats ; Animals ; Glutamic Acid/pharmacology* ; alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid/pharmacology* ; N-Methylaspartate/pharmacology* ; Carotid Body ; Rats, Sprague-Dawley ; Carbon Dioxide ; Receptors, N-Methyl-D-Aspartate ; Receptors, AMPA ; Hypoxia

The purpose of the present study was to explore the role of carotid body metabotropic glutamate receptor 1 (mGluR1) in chronic intermittent hypoxia (CIH)-induced carotid body plasticity. Sprague Dawley (SD) rats were exposed to CIH (6%-21% O₂, 4 min/cycle, 8 h/day) for 4 weeks. The blood pressure of rats was monitored non-invasively by tail-cuff method under consciousness. RT-qPCR was used to examine the mRNA expression level of mGluR1 in rat carotid body. Western blot was used to detect the protein expression level of mGluR1 in rat carotid body. The role of mGluR1 in CIH-induced carotid body sensory long-term facilitation (sLTF) was investigated by ex vivo carotid sinus nerve discharge recording, and the carotid body sLTF was evoked by a 10-episode of repetitive acute intermittent hypoxia (AIH: 1 min of 5% O₂ interspersed with 5 min of 95% O₂). The results showed that: 1) CIH increased the systolic blood pressure (P < 0.001), diastolic blood pressure (P < 0.005) and mean arterial blood pressure (P < 0.001) of rats; 2) CIH decreased the mRNA and protein levels of mGluR1 in the rat carotid body (P < 0.01); 3) 4 weeks of CIH induced carotid body sLTF significantly, exhibiting as an increasing baseline sensory activity during post-AIH, which was inhibited by application of an agonist of group I metabotropic glutamate receptors, (S)-3,5-dihydroxyphenylglycine (DHPG), during sLTF induction (P < 0.005). In summary, these results suggest that activation of mGluR1 inhibits CIH-induced carotid body plasticity in rats.
Rats ; Animals ; Carotid Body/metabolism* ; Rats, Sprague-Dawley ; Hypoxia ; Receptors, Metabotropic Glutamate/metabolism* ; RNA, Messenger/metabolism*

Objective: To investigate the feasibility of isolation and culture of human adenoid-derived mesenchymal stem cells (aMSCs) in vitro, and to observe the differentiation of aMSCs into olfactory sensory neurons. Methods: Adenoid tissues surgically removed from children with adenoid hypertrophy in the Second Xiangya Hospital of Central South University from September to November of 2020 were collected. The adenoid tissues were digested and isolated by trypsin and then cultured with adhesion method. The expressions of cell surface antigens CD45, CD73 and CD90 on aMSCs of P5 generation were tested by flow cytometry, and the ability of osteogenic and adipogenic induction were used to identify cell differentiation ability. Then, aMSCs were induced into differentiation by retinoic acid (RA), sonic hedgehog (SHH), basic fibroblast growth factor (bFGF), RA+SHH, RA+bFGF, SHH+bFGF and RA+SHH+bFGF, respectively. The morphology of differentiated cells was observed under inverted microscope. The expression of β-tubulin 3, which was the specific marker of sensory neuron, the expressions of growth associated protein-43 (GAP43) and olfactory maker protein (OMP), which were the specific markers of olfactory sensory neuron, were detected by immunofluorescence antibody assay. The expression intensities were compared by Chi-square test of four-grid table data. Results: aMSCs were successively isolated and cultured from human adenoid tissues. P0 cells generation had good adhesion and proliferation performance. P2 cells were basically purified. P5 cells expressed CD73 and CD90 with the purity of 99.3% and 99.75% respectively, without CD45 expression. P5 cells had a good ability of osteogenic differentiation and adipogenic differentiation. Neuron-like morphology and expression of β-tubulin 3 were found in differentiated cells after induced by RA, SHH, or bFGF, respectively. An induction of expression of GAP43 was found in differentiated cells of bFGF+SHH group and RA+SHH+bFGF group, without expression of OMP of each group. The intensity of GAP43 expression of RA+SHH+bFGF group was stronger than that of bFGF+SHH group (χ²=17.48, P<0.005). Conclusions: aMSCs can be cultured from human adenoid tissues, with the stably passaged and good differentiation ability. As a new population of mesenchymal stem cells, aMSCs have the neuroregenerative properties and could differentiate into immature olfactory sensory neurons under the induction of RA+SHH+bFGF in vitro.
Child ; Humans ; Hedgehog Proteins ; Olfactory Receptor Neurons ; Tubulin ; Adenoids ; Osteogenesis ; Cell Differentiation

The dorsal lingual epithelium, which is composed of taste buds and keratinocytes differentiated from K14⁺ basal cells, discriminates taste compounds and maintains the epithelial barrier. N6-methyladenosine (m⁶A) is the most abundant mRNA modification in eukaryotic cells. How METTL3-mediated m⁶A modification regulates K14⁺ basal cell fate during dorsal lingual epithelium formation and regeneration remains unclear. Here we show knockout of Mettl3 in K14⁺ cells reduced the taste buds and enhanced keratinocytes. Deletion of Mettl3 led to increased basal cell proliferation and decreased cell division in taste buds. Conditional Mettl3 knock-in mice showed little impact on taste buds or keratinization, but displayed increased proliferation of cells around taste buds in a protective manner during post-irradiation recovery. Mechanically, we revealed that the most frequent m⁶A modifications were enriched in Hippo and Wnt signaling, and specific peaks were observed near the stop codons of Lats1 and FZD7. Our study elucidates that METTL3 is essential for taste bud formation and could promote the quantity recovery of taste bud after radiation.
Animals ; Epithelium/metabolism* ; Homeostasis ; Methylation ; Methyltransferases/metabolism* ; Mice ; RNA ; Taste Buds/metabolism*

Cranial Fossa, Middle ; Ear Neoplasms/surgery* ; Ear, Middle ; Glomus Tympanicum ; Humans

Objective To investigate the risk factors for patients using intraoperative vasopressor infusions during carotid body tumor(CBT)excision.Patients' mean arterial pressure(MAP)and heart rate(HR)fluctuations as well as their requirements for vasoactive agents during surgery were assessed. Methods The patients receiving CBT excision in Peking Union Medical College Hospital from May 1,2013 to July 31,2017 were included for a retrospective cohort study.The potential factors of intraoperative requirement for vasopressor infusions were investigated using univariate analysis and Logistic multivariate analysis.Furthermore,the relationships of Shamblin types of CBT with intraoperative MAP/HR fluctuations and requirements for vasoactive agents were analyzed. Results A total of 108 patients with 116 CBTs were included.Univariate analysis revealed that maximum tumor diameter >4 cm,intraoperative internal carotid artery injury,internal carotid artery reconstruction,malignant pathology,advanced Shamblin types(type Ⅱ and Ⅲ),estimated blood loss ≥400 ml,and operation duration >4 hours were associated with intraoperative requirements for vasopressor infusions.Logistic analysis showed that Shamblin type Ⅲ(OR=2.286,95% CI=1.324-14.926,P=0.016)and operation duration >4 hours(OR=3.874,95% CI=1.020-14.623,P=0.046)were risk factors for intraoperative requirements for vasopressor infusions during CBT surgery.In addition,Shamblin type Ⅲ was associated with intraoperative abnormal HR elevation and requirements for vasopressors.Conclusions Shamblin type Ⅲ and operation duration>4 hours are risk factors for intraoperative requirements of patients for using vasopressor infusions during CBT surgery.Shamblin type Ⅲ is associated with intraoperative abnormal HR elevation and requirements for vasopressors.
Carotid Body Tumor ; Humans ; Retrospective Studies ; Risk Factors ; Treatment Outcome ; Vascular Surgical Procedures

OBJECTIVES: To identify the alternative splicing isoform of mouse sweet taste receptor T1R2, and investigate the effect of lipopolysaccharide (LPS) local injection on T1R2 alternative splicing and the function of sweet taste receptor as one of the bacterial virulence factors. METHODS: After mouse taste bud tissue isolation was conducted, RNA extraction and reverse transcription polymerase chain reaction (PCR) were performed to identify the splicing isoform of T1R2. Heterologous expression experiments RESULTS: T1R2 splicing isoform T1R2_Δe3p formed sweet taste receptors with T1R3, which could not be activated by sweet taste stimuli and significantly downregulated the function of canonical T1R2/T1R3. Local LPS injection significantly increased the expression ratio of T1R2_Δe3p in mouse taste buds. CONCLUSIONS LPS stimulation affects the alternative splicing of mouse sweet taste receptor T1R2 and significantly upregulates the expression of non-functional isoform T1R2_Δe3p, suggesting that T1R2 alternative splicing regulation may be one of the mechanisms by which microbial infection affects host taste perception.
Alternative Splicing ; Animals ; Lipopolysaccharides ; Mice ; Receptors, G-Protein-Coupled/metabolism* ; Taste ; Taste Buds