Investigation of N-Glycan Functions in Receptor for Advanced Glycation End Products V Domain through Chemical Glycoprotein Synthesis.

The receptor for advanced glycation end products (RAGE) plays a crucial role in inflammation-related pathways and various chronic diseases. Despite the recognized significance of N-glycosylation in the ligand-binding V domain (VD) of RAGE, a comprehensive understanding of the site-activity and structure-activity relationships is lacking due to the challenges in obtaining homogeneous glycoprotein samples through biological expression. Here, we combined chemical and chemoenzymatic approaches to synthesize RAGE-VD and its congeners with Asn3-glycosylation by incorporating precise N-glycan structures. Evaluation of these samples revealed that, in comparison to other RAGE-VD forms, α2,6-sialylated N-glycosylation at the Asn3 site results in more potent inhibition of HMGB1-induced nuclear factor-κB (NF-κB) expression in RAGE-overexpressing cells. Hydrogen/deuterium exchange-mass spectrum analysis revealed a sialylated RAGE-VD-induced interaction region within HMGB1. Conversely, Asn3 N-glycosylation in VD has negligible effects on RAGE-VD/S100B interactions. This study established an approach for accessing homogeneously glycosylated RAGE-VD and explored the modulatory effects of N-glycosylation on the interactions between RAGE-VD and its ligand proteins.

Facile Preparation of Carbohydrate-Containing Adjuvants Based on Self-Assembling Glycopeptide Conjugates.

Carbohydrates are intriguing biomolecules possessing diverse biological activities, including immune stimulating capability. However, their biomedical applications have been limited by their complex and heterogeneous structures. In this study, we have utilized a self-assembling glycopeptide conjugate (GPC) system to produce uniform nanoribbons appending homogeneous oligosaccharides with multivalency. This system successfully translates the nontrivial structural differences of oligomannoses into varied binding affinities to C-type lectin receptors (CLRs). We have shown that GPCs could promote the CLR-mediated endocytosis of ovalbumin (OVA) antigen, and two mannotriose-modified peptides F3m2 and F3m5 exhibit potent activity in inducing antigen-presenting cell maturation, as indicated by increased CD86 and MHCII expression. In vivo studies demonstrated that GPCs, combined with OVA antigen, significantly enhanced OVA-specific antibody production. Specifically, F3m2 and F3m5 exhibited the highest immunostimulatory effects, eliciting both Th1- and Th2-biased immune responses and promoting differentiation of CD4+ and CD8+  T cells. These findings highlight the potential of GPCs as vaccine adjuvants, and showcase their versatility in exploiting the biological functions of carbohydrates.

Discovery of endosomalytic cell-penetrating peptides based on bacterial membrane-targeting sequences.

Cell-penetrating peptides (CPPs) are prominent scaffolds for drug developments and related research, particularly the endocytic delivery of biomacromolecules. Effective cargo release from endosomes prior to lysosomal degradation is a crucial step, where the rational design and selection of CPPs remains a challenge and calls for deeper mechanistic understandings. Here, we have investigated a strategy of designing CPPs that selectively disrupt endosomal membranes based on bacterial membrane targeting sequences (MTSs). Six synthesized MTS peptides all exhibit cell-penetrating abilities, among which two d-peptides (d-EcMTS and d-TpMTS) are able to escape from endosomes and localize at ER after entering the cell. The utility of this strategy has been demonstrated by the intracellular delivery of green fluorescent protein (GFP). Together, these results suggest that the large pool of bacterial MTSs may be a rich source for the development of novel CPPs.

Site-Specific Protein Modification with Reducing Carbohydrates.

Protein glycosylation plays critical roles in many biological processes. However, the fundamental study and application of glycobiology are hindered by the heterogeneousness of oligosaccharides in natural glycoproteins and the difficulty in constructing glycoproteins of human design. Herein, we describe a semisynthetic method to site-specifically modify proteins with reducing carbohydrates. The method involves the genetic incorporation of a side-chain-esterified aspartate, which was subsequently quantitatively converted into alanine-ß-hydrazide (Aßz), and chemoselective conjugation of Aßz with a range of readily available reducing carbohydrates. The resulting Aßz-linked GlcNAc is a close mimic of native N-GlcNAc and could be installed on various proteins, including IL-17A and RNase A. Notably, Aßz-linked GlcNAc on proteins reacted with biantennary oligosaccharide oxazoline derivatives through endoglycosidase-catalyzed transglycosylation reactions to enable the assembly of homogeneous glycans on proteins.

The significance of serum soluble intercellular adhesion molecule 1 and transforming growth factor alpha in patients with nasopharyngeal carcinoma.

OBJECTIVE: To determine serum levels of soluble intercellular adhesion molecule 1 (sICAM-1) and transforming growth factor alpha (TGF-alpha) in 51 patients with nasopharyngeal carcinoma before, during, and after radiation therapy (5-year follow-up period). RESULTS: The mean +/- SD serum levels of the 2 cytokines were found to be higher in patients before radiotherapy (sICAM-1, 369.6 +/- 123.7 ng/mL; TGF-alpha, 36.6 +/- 24.6 ng/mL) than after radiotherapy (sICAM-1, 225.9 +/- 124.3 ng/mL; TGF-alpha, 20.2 +/- 22.3 ng/mL) (P<.05), and they were significantly higher in patients with recurrence (sICAM-1, 512.5 +/- 271.2 ng/mL; TGF-alpha, 48.2 +/- 23.4 ng/mL) and in those who died (sICAM-1, 542.6 +/- 245.4 ng/mL; TGF-alpha, 50.2 +/- 28.8 ng/mL) than in patients with no recurrence (sICAM-1, 217.9 +/- 116.4 ng/mL; TGF-d, 21.5 +/- 26.8 ng/mL) and in those who survived (sICAM-1, 209.4 +/- 167.2 ng/mL; TGF-alpha, 20.4 +/- 27.3 ng/mL) (P<.05). The increases in serum levels occurred approximately 3 months before relapse. CONCLUSION: We found that sICAM-1 and TGF-alpha levels are extremely useful markers for predicting illness, recurrence, and survival.

Significance of c-Myc and Bcl-2 protein expression in nasopharyngeal carcinoma.

OBJECTIVE: To investigate the relationship between oncogene protein expression and nasopharyngeal carcinoma outcome. DESIGN: Tumor samples from 51 patients with nasopharyngeal carcinoma were analyzed by immunohistochemical staining for expression of Bcl-2 and c-Myc protein before irradiation. Five-year follow-up data were available. RESULTS: Thirty-one (61%) of 51 tumors expressed Bcl-2 protein, and 29 (57%) of 51 tumors expressed c-Myc protein. In the Bcl-2+ group, 20 (65%) and 19 (61%) of 31 patients experienced recurrence or died, respectively, whereas only 7 (35%) and 5 (25%) of 20 patients with Bcl-2- tumors did so. On the other hand, patients with c-Myc+ tumors had lower recurrence and death rates (38% [11/29] and 34% [10/29], respectively) than those with c-Myc- tumors (73% [16/22] and 64% [14/22], respectively). A statistically significant association was confirmed between Bcl-2 and c-Myc positivity and patient outcome. CONCLUSION: Expression of Bcl-2 and c-Myc protein seems to be a useful marker to reflect irradiation response and to predict illness condition and patient outcome.

A controlled study of the upper airway structure and function in patients with obstructive sleep apnea syndrome and normal adults.

OBJECTIVE: To investigate the major factors associated with the development of obstructive sleep apnea syndrome (OSAS) by logistic step regression analysis. METHOD: Fifty-nine patients with OSAS and 57 normal adults were included in the study. The dependent was whether the subject had OSAS, and the independents included age, sex, body mass index (BMI), as well as the measured data of palate, uvula, lingua and epiglottis by CT scan. Logistic regression was performed by using SPSS software. RESULTS: Among 40 independents, 8 were chosen by logistic regression as the major factors associated with the risk of developing OSAS. These factors were the increase of pharyngeal wall resilience in the uvula region, the thickness of the retropharyngeal soft tissue in the uvula and palate region, the increase of genioglossus width, the decrease of cross section of the palate region, the decrease of the coronal diameter of the uvula and lingual region, and a narrowed diameter of the uvula region. CONCLUSION: The results suggest that anatomic changes of the upper airway at different levels and an increase of the pharyngeal wall resilience in the uvula region are major etiological factors for OSAS.

[Treatment and prevention of serious perioperative complications of obstructive sleep apnea hypopnea syndrome].

OBJECTIVE: To summarize experiences of serious perioperative complications management of obstructive sleep apnea hypopnea syndrome (OSAHS), and evaluate the effect of intervention in decreasing the incidence of serious complications. METHODS: Retrospective analysis of clinical data in Shenyang General Hospital of PLA and Liaoning Province Jinqiu Hospital of OSAHS surgery cases from January 1995 to December 2009 were included in this study, patients were divided into two groups according to with or without intervention. Experience and lessons were analyzed. RESULTS: Patients without and with intervention were 402 and 521 respectively, and uvulopalatopharyngoplasty (UPPP) cases in each group were 387 and 390. Five patients in the first group who accepted UPPP had breathing difficulty and were all successfully rescued, while no one in the second group had breathing difficulty. The difference was significant (P < 0.05). Sixteen patients in the first group had severe bleeding after UPPP, while only 5 patients had the severe bleeding in the second group. The difference was significant, too P < 0.05. No breathing difficulty cases in the second group, and serious bleeding cases in each group was 5 and in 1, there was no significant difference (P > 0.05). CONCLUSIONS: Breath difficulty and serious bleeding are serious perioperative complications of OSAHS surgery, and with systemic intervention the incidence of the complications can be decreased.

[Study of lingual arterial CT angiography and security of partial glossectomy in obstructive sleep apnea hypopnea syndrome].

OBJECTIVE: To explore the difference of lingual arterial CT angiography images(CTA) between obstructive sleep apnea hypopnea syndrome (OSAHS) patients and normal subjects, and to investigate the safety of partial glossectomy guided by lingual arteria CT angiography. METHODS: Seventy-four patients with OSAHS and 10 control adults were included in the study. The lingual upper airway and lingual arterial CT angiography were obtained. The area and the dimensions of lingual upper airway, and the length and thickness of lingua, length of lingual arteria, depth and bilateral lingual arteria spacing were studied. The CT measuring data of OSAHS patients and normal adults were compared. The multinomial logistic regression analysis was used to investigate the main factors which affects the lingual arterial measuring results. Guided by the lingual arterial CT angiography and measuring results, glossectomy was performed in 23 OSAHS patients with lingua hypertrophy. RESULTS: The area and dimensions of lingual airway of OSAHS patients were less than those of control adults, and the length and thickness of lingua of OSAHS were more than those of control adults (t test, P < 0.05 or P < 0.01). There were no difference in length of lingual arteria and bilateral lingual arteria spacing between OSAHS patients and control adults. The 3 measured points' depth (x(-) +/- s) of lingual arteria of OSAHS patients were (29.1 +/- 5.5) mm, (26.9 +/- 5.1) mm and (25.6 +/- 5.2) mm, respectively, and those of control adult were (23.0 +/- 3.8) mm, (22.6 +/- 2.7) mm and (21.5 +/- 2.6) mm, the depth of lingual arteria of OSAHS was more than that of control adults (t test, P < 0.05 or P < 0.01). The main factors affects lingual arterial depth were body mass index (BMI), lingual length and lingual thickness, unstandardized regression coefficient were 0.255, 0.11 and 0.03, respectively (analysis of variance, F = 6.216, P < 0.05). No damage of lingual arteria and nerve in 23 patients who had expanded glossectomy. CONCLUSIONS: The study showed statistical difference significance of lingual arterial CTA measurements between OSAHS patients and control adults. Guided with lingual arteria CTA data, the expanded glossectomy in OSAHS patients has proved good safety and high cure rate.

[Frontal sinusitis after transfrontal craniotomy: causes and management].

OBJECTIVE: To explore the causes, clinical manifestation and therapy of frontal sinusitis after transfrontal craniotomy. METHODS: Thirty-three patients with frontal sinusitis after transfrontal craniotomy were included in the study. Among them, 7 cases had frontal sinus abscess and 4 cases had frontal sinus fistula. Twenty-three patients were treated with traditional frontal sinus surgery with facial incision. The nasofrontal dilatation tube was positioned for more than 3 months. Nine patients were treated with endoscopic frontal sinus surgery, and 1 patient was treated with combined endoscopic and traditional frontal sinus surgery, with nasofrontal dilatation tube positioned for less then 1 month. In the revision surgery, the bone wax and phlogistic acestoma were cleaned out in both operational methods. The causes of frontal sinusitis after transfrontal craniotomy were discussed by studying the frontal sinus CT image, and prior surgical data. RESULTS: All patients were followed up for more than 6 months after the nasofrontal dilatational tube was removed. Among 33 patients, two cases with traditional frontal sinus surgery were operated twice due to nasofrontal dilatation tube fall off in 1 month. In all 33 patients, 30 cases cured and 3 cases got better. There were no curative difference between two operational methods. CONCLUSIONS: The causes of frontal sinusitis after transfrontal craniotomy were inadequate sinus management in craniotomy and bone wax tamping in frontal sinus. There was more frontal sinus abscess and fistula occurring in frontal sinusitis after transfrontal craniotomy than that in ordinary frontal sinusitis. The therapy included cleaning out bone wax and phlogistic acestoma, and expanding the frontal sinus ostium. The satisfying curative effect was obtained in both operational methods, but endoscopic frontal sinus surgery was better because it is minimally invasive, no facial incision and quick recovery with less nasofrontal dilatational tube posting time.

[The effects of pressure level in veil on upper airway in patients with obstructive sleep apnea hypopnea syndrome].

OBJECTIVE: To observe the effects of pressure level in veil on upper airway in patients with obstructive sleep apnea hypopnea syndrome (OSAHS) and normal adults. METHOD: We scanned the upper airway from roof of nasopharynx to glottis with SIMENS 16 layer spiral CT scanner. The area and the dimensions of palate, uvula, and the region after lingua and epiglottis were measured by application of image work station. Forty-six patients with OSAHS and 35 normal adults were scanned by CT at 0 kPa water column and 0.784 kPa water column pressures in face mask, respectively. RESULT: The area and inner diameter of OSAHS patients upper airways were less than those of normal adults at the same pressure in face mask. The area and inner diameter of upper airway at the pressure of 0.784 kPa water column were more than those at 0 kPa water column in both OSAHS patients and normal adults, and the increased extent of normal adults were more than those of OSAHS patients. We measured the minimum increased normal Cross sectional area of palate, uvula, and the region after lingua and epiglottis when the pressure in the mask increased from 0 kPa to 0.784 kPa, and we made it as the standard. The 46 OSAHS patients were sorted into 17 cases (group 1) with normal dilation and 29 cases (group 2) with less dilation in such standard. There was not significant difference between the two groups at 0 kPa pressures in area and inner diameter, but the area and inner diameter of group 1 were more than those of group 2 at 0.784 kPa pressure. CONCLUSION: The increased pressure in face mask would lead to upper airway dilation both in OSAHS patients and normal adults, and the dilated extents of normal adults were significant more than those of OSAHS patients. The less dilation of OSAHS may be duo to anatomic constriction and some pharynx wall pathological changes.

[Relationship of lingual region upper airway stricture and lingua-palate position type in obstructive sleep apnea hypopnea syndrome patients].

OBJECTIVE: To explore the relationship ol lingual region upper airway stricture and lingua-palate position type in obstructive sleep apnea hypopnea syndrome (OSAHS) patients. METHODS: One hundred patients with OSAHS were included in the study and divided into 4 groups by lingua-palate age, AHI, BMI and lowest SaO2, the dimensions and area of lingual region airway, the thickness of retropharyngeal and lateral pharyngeal tissue, the tongue width, tongue length and tongue area were compared among four groups. The multinomial step regression process was performed with SPSS software to explore the effects of lingua-palate position type on lingual region upper airway stricture. RESULTS: There were no statistical difference of age, BMI, AHI and lowest pulse oxygen among four groups OSAHS patients (P > 0.05). And the CT results showed: starting from type I to type IV, the area, coronal and arrowe diameter of lingual region upper airways were decreasing, tongue length, tongue area and the percentage of lingual region airway stricture were increasing, the percentage of lingual region airway stricture were 0/25, 3/39, 7/22, 14/14, respectively (P < 0.05). The multinomial step regression analysis showed that the area of lingual airway was the most important factor of lingua-palate position type, the unstandardized coefficient was -0.39, and standardized coefficient was -0.545. CONCLUSIONS: The study suggests that there is evident correlation between lingual region airway stricture and lingua-palate position type, and lingual region airway stricture can be roughly determined by lingua-palate position type.

[Quantitative evaluation of the upper airway by CT scan with the Muller maneuver].

OBJECTIVE: To explore the quantitative evaluation of upper airway by CT scan with Muller maneuver, and study the difference of the pharynx wall resilience between OSAHS patients and normal adults. METHOD: Twenty-five patients with OSAHS and 20 normal adults were included in the study. CT evaluated the upper airway from roof of nasopharynx to glottis with the use of a Phlips Tomoscan AV Expander E1 spiral scanner. The cross section area and the dimension of palate, uvula, lingua and epiglottis region upper airway were studied. Then repeated the same scan process when testee play-ed Muller maneuver, and calculated the total pharynx wall resilience (TPWR), lateral pharynx wall resilience (LPWR) and anterior post-pharynx wall resilience (APPWR) of different levels of upper airway. RESULT: Between OSAHS patients and normal adults, there are obviously difference in the TPWR and LPWR of palate, uvula, lingua region upper airway, and no difference in epiglottis region upper airway. There are obviously difference in the APPWR of palate and uvula region upper airway, and no difference in lingua and epiglottis region upper airways. The LPWR is much more than APPWR in all four level of upper airway in both OSAHS patients and normal adults. CONCLUSION: The study suggest that we can get quantitative data of upper airways by CT scan. And there are obviously TPWR, LPWR and APPWR difference at different levels of upper airway between OSAHS patients and normal adult, the increasing of TPWR, LPWR and APPWR is one etiology of OSAHS.

[The relationship of lingua and uvula in OSAS].

OBJECTIVE: To observe the relationship between lingual base and uvula, the relationship between lingua and jaw dentition in normal adults, snorers and patients with obstructive sleep apnea syndrome (OSAS) and to study the difference of the relationships among them. METHOD: 21 patients with OSAS, 25 snorer and 30 normal adults were included in the study. The relationship between lingua and uvula and the relationship between lingual base and jaw dentition were observed. The difference of the relationships among the OSAS patients, snorers and normal adults were studied. RESULT: Among the OSAS patients, snorer and normal adults, there are obviously difference in the relationship between lingua and uvula and the relationships between lingual base and jaw dentition. In normal adults, the lingua below to jaw dentition and the uvula is visible at opening of mouth; in snorers, the lingua match the jaw dentition and the uvula is visible at pronunciation; in OSAS patients, the lingua tower above the jaw dentition and the uvula is sightless at pronunciation. CONCLUSION: The study suggests that the enlarge of lingua and uvula be the one of etiology of OSAS.

[The lingual region upper airway CT scan of obstructive sleep apnea patients].

OBJECTIVE: To compare the lingual region upper airway CT scan results of OSAS patients and normal adults to explore if there are upper airway stricture in OSAS patients and the reason of stricture. METHODS: 59 patients with OSAS and 57 normal adults were included in the study. CT evaluated the lingual region upper airway with the use of a Philips Tomoscan AV Expander E1 spiral scanner. The shapes of lingual region upper airway were observed. The area and the dimensions of lingual region was studied, and the thickness of retropharyngeal and lateral pharyngeal tissue were evaluated too. The another focus area was tongue, and the evaluated data included the tongue width, genioglossus width, hyogolssus width, tongue length and tongue area. RESULTS: The data comparative results of OSAS and normal groups were as follows: the right to left diameter and area of OSAS patients' lingual region upper airways were less than those of normal adults, the thickness of lateral pharyngeal, tongue width, genioglossus width, hyogolssus width and tongue area were more than those of normal adults. And there were not obviously difference between OSAS patients and normal adults in tongue length, anterior-to-posterior dimension and thickness of retropharyngeal wall tissue of upper airway. CONCLUSIONS: The study suggests that there are obviously difference between the patients with OSAS and normal adult in lingual upper airway CT scan measure. And the anatomic stricture of lingual upper airway is one of the etiology of OSAS. The main reasons of stricture are increasing of thickness of lateral pharyngeal, tongue width, genioglossus width, hyogolssus width and tongue area.

[The effects of body posture on upper airway in OSAHS patients].

OBJECTIVE: To explore the effects of body posture on upper airway shapes in OSAHS patients. METHOD: Thirty-one male OSAHS patients were included in the study. The fibre endoscopic photos were taken on palate and lingua region upper airway at normal breath at supine with 30 degree neck flexion, supine and right lateral recumbent position, respectively. The cross section area and the dimensions of palate and lingua region upper airway were studied by running image tools software in computer. RESULT: In OSAHS patients, there were obviously difference in the area and arrowy dimension of palate airway among three posture, and so to in area, arrowy and coronary dimension of lingua airway. CONCLUSION: The study suggests that the body posture changes have obviously influence on upper airway, and the influence is the base of apnea increasing at special posture.

[The upper airway CT scan in patients with obstructive sleep apnea syndrome].

OBJECTIVE: To compare the CT scan results in OSAS patients and normal adults so as to explore its value in measuring upper airway structure. METHOD: 53 patients with OSAS and 53 normal adults were included in the study. The upper airway from roof of nasopharynx to glottis was evaluated with the use of a Phlips Tomoscan AV Expander E1 spiral scanner. The area and the dimensions of palate, uvula, lingua and epiglottis region was studied, and the thickness of retropharyngeal and lateral pharyngeal tissue were evaluated, too. RESULT: There were obviously differences between OSAS patients and normal adults in the areas of palate, uvula, lingua, and there are differences of dimension and thickness in different sites. CONCLUSION: The study suggests that there is a obviously difference between the patients with OSAS and normal adult in upper airway by CT scan. The anatomic structure of upper airway is one of causes of OSAS.

[Localization of upper airway stricture in patients with obstructive sleep apnea syndrome by CT scan].

OBJECTIVE: To evaluate the diagnostic significance of CT scan in the localization of the stricture in the upper airway in patients with obstructive sleep apnea syndrome (OSAS). METHODS: Fifty-four patients with OSAS were included in this study. CT scan evaluated the upper airway from the roof of nasopharynx to the glottis using a Phlips Tomoscan AV Expander E1 spiral scanner. The areas and the dimensions of palate, uvula, lingua and epiglottis region, as well as the thickness of retropharyngeal and lateral pharyngeal tissue was evaluated. The reference values had been set-up in 225 normal adult upper airways CT scan, some patients' results were compared with the CT scan results during apnea. RESULTS: There were no any upper airway stricture in 12 patients with OSAS, and there were one or more upper airway stricture sites in other 42 patients. Twenty-four patients had only one stricture site. Fourteen patients had 2 adjacent stricture sites. One patient had three stricture sites. Three patients had 4 upper airway strictures. There was a good concordance between the results of CT scans during awakening and sleeping in 14 patients. CONCLUSION: Most patients with OSAS had anatomic upper airway strictures, the CT scan can localize the stricture site very well.