Integrative Analysis Reveals STC2 as a Prognostic Biomarker of Laryngeal Squamous Cell Carcinoma.

Stanniocalcin 2 (STC2) is involved in many tumour types, but it remains unclear what its biological function is in laryngeal squamous cell carcinoma (LSCC). Therefore, we investigated STC2's expression, potential function, and prognostic significance of in LSCC. The expression and prognosis of STC2 in LSCC were described using the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. In the TCGA database, the relationship between STC2 and immune infiltration, expression of immune cell chemokine and receptor genes, immune cell molecular marker genes, and epithelial‒mesenchymal transition (EMT) marker genes were analysed. The biological processes involved in STC2 and its expression-related genes were analysed comprehensively using bioinformatics. The single-gene ceRNA network of STC2 was constructed in the TCGA database. Finally, LSCC patients' tumour tissue STC2 expression was verified. STC2 silencing with the RNAi technique was used for the determination of cellular functions in a laryngeal cancer cell line. STC2 expression was higher in most tumours, including LSCC, than in normal tissues and was associated with poor prognosis. The relative proportions of naïve B, plasma, follicular helper T, and macrophage M0 cells in LSCC and normal samples differed significantly. STC2 expression correlated significantly positively with that of TGFB1 (biomarker of Tregs) and significantly negatively with that of D79A and CD19 (biomarkers of B cells). Furthermore, STC2 affected chemokine and receptor gene expression in immune cells. STC2 expression correlated with EMT marker gene expression in LSCC. STC2 was enriched in the PI3K/AKT signalling pathway, extracellular matrix (ECM) organisation, ECM-receptor interaction, and other tumour-related signalling pathways. STC2 was highly expressed in our clinical samples. N-cadherin and vimentin expression were decreased in the TU686 cell line after successful silencing of STC2, indicating that high STC2 expression may prompt LSCC cells to adopt a mesenchymal cell phenotype. STC2 silencing substantially reduced proliferation and migration in the TU686 cell line. STC2 may be a promising predictive biomarker for tumours, providing new approaches for LSCC diagnosis and treatment monitoring.

Toxicity of micro(nano)plastics with different size and surface charge on human nasal epithelial cells and rats via intranasal exposure.

Micro (nano)plastics (MNPs) have become emerging environmental contaminants, yet their toxicity and systemic effects via intranasal exposure remain unclear. This study investigated the in vitro toxicity of thirteen polystyrene MNPs with different surface functionalization (carboxylic (C-PS), amino (A-PS), and bare (PS)) and sizes (20-2000 nm) on human nasal epithelial cells (HNEpCs) at 10-1250 µg/mL as well as their in vivo toxicity to rats via intranasal administration at 125 µg/mL. The in vitro study showed that PS20, PS50, A-PS50, PS500, and A-PS500 significantly inhibited cell viability, which was dependent on particle concentration. A-PS induced higher cytotoxicity than C-PS and PS, and most MNPs inhibited cell proliferation after 24-h. Flow cytometry analysis suggested that PS induced cell apoptosis, while A-PS caused cell necrosis. MNPs were phagocytosed by HNEpCs and entered nucleus. The in vivo study showed that MNPs inhibited dietary behaviors of rats. Histological analysis indicated that PS20, PS200, and A-PS50 thinned out nasal mucosa. Immunohistochemical analysis revealed that exposure to PS20, PS200, and A-PS50 enhanced expression of transient receptor potential cation channel subfamily M (melastatin) member 8 (TRPM8). Systemic effects including hepatocyte cytoplasmic vacuolation and renal tubule dilatation were observed. The results suggested that nasal inhalation of MNPs may disturb energy metabolism and damage upper respiratory tract, liver, and kidneys.

Effects of combination docetaxel with NO treatment to enhance the anti-nasopharyngeal carcinoma efficiency in vitro and in vivo.

Nasopharyngeal carcinoma (NPC) is one of the major causes of death in Southern China. Due to the insidious location of NPC, the therapeutic effect of locoregionally advanced NPC is still unsatisfactory. In this work, to improve the treatment efficiency, combining DOC and JS-K to inhibit NPC cells (HNE-1) in vitro was investigated, as well as its possible mechanisms. Moreover, the in vivo effects of DOC and JS-K combination treatment were also evaluated in a xenograft model with HNE-1 cells. In vitro experiments including cell proliferation, migration ability, apoptosis, and expression levels of apoptosis-associated proteins revealed that the combination of DOC and JS-K was able to enhance antitumor effects. In vivo results further confirmed a significant treatment effect without obvious toxicity on mice. The present work provides a promising idea for the treatment of locally advanced NPC.

Upregulation of Long Noncoding RNA_GAS5 Suppresses Cell Proliferation and Metastasis in Laryngeal Cancer via Regulating PI3K/AKT/mTOR Signaling Pathway.

BACKGROUND: Laryngeal cancer is one of the most common malignant tumors among head and neck cancers. Accumulating studies have indicated that long noncoding RNAs (lncRNAs) play an important role in laryngeal cancer occurrence and progression, however, the functional roles and relative regulatory mechanisms of lncRNA growth arrest-specific transcript 5 (GAS5) in laryngeal cancer progression remain unclear. METHODS: The expression of lncRNA GAS5 in both laryngeal cancer tissues and cell lines was evaluated using quantitative reverse transcription-polymerase chain reaction (RT-qPCR) assay. The relationships between lncRNA GAS5 expression and clinical parameters were also analyzed. To determine the biological function of lncRNA GAS5, a lncRNA GAS5-specific plasmid was first transfected into laryngeal cancer cells using lentiviral technology. Cell counting kit-8 assay, flow cytometry, and Transwell assays were used to detect in vitro cell proliferation, apoptosis, cycle distribution, and metastasis abilities, respectively. Furthermore, in vivo cell growth experiments were also performed using nude mice. Additionally, western blotting was performed to identify the underlying regulatory mechanism. RESULTS: In the current study, lncRNA GAS5 was downregulated in laryngeal cancer tissues and its low expression was closely associated with poor tumor differentiation, advanced TNM stage, lymph node metastasis, and shorter overall survival time. In addition, lncRNA GAS5 upregulation significantly inhibited laryngeal cancer cell proliferation both in vitro and in vivo. Moreover, in response to lncRNA GAS5 overexpression, more laryngeal cancer cells were arrested at the G2/M stage, accompanied by increased cell apoptosis rates and suppressed migration and invasion capacities. Mechanistically, our data showed that the overexpression of lncRNA GAS5 significantly regulated the PI3K/AKT/mTOR signaling pathway. CONCLUSION: LncRNA GAS5 might act as a suppressor gene during laryngeal cancer development, as it suppressed cell proliferation and metastasis by regulating the PI3K/AKT/mTOR signaling pathway; thus, lncRNA GAS5 is a promising therapeutic biomarker for the treatment of laryngeal cancer.

MiR-125a-5p inhibits cell proliferation, cell cycle progression, and migration while promoting apoptosis in head and neck cancers by targeting ERBB3.

OBJECTIVE: Head and neck cancer is one of the most common cancer types worldwide. MicroRNAs play a vital regulatory role in the occurrence and development of cancer. The objective of this study is to explore the mechanism of miR-125a-5p in the proliferation, migration and apoptosis of head and neck cancer cells and define its target genes. METHODS: The effects of miR-125a-5p on head and neck cancer cells proliferation, cell cycle distribution, apoptosis and migration were evaluated by colony formation, BrdU assay, flow cytometry and transwell assays. The potential target gene of miR-125a-5p was determined by luciferase activity assay and western blot analysis. RESULTS: In this study, overexpression of miR-125a-5p significantly inhibited the proliferation of head and neck cancer cells, whereas inhibition of miR-125a-5p enhanced their proliferation. BrdU assay and flow cytometry revealed that miR-125a-5p might inhibit the proliferation of cancer cells by causing cell cycle arrest. Cell apoptosis assay and Transwell assay indicated that miR-125a-5p induced cell apoptosis and inhibited cell migration of cancer cells. Other experiments confirmed that miR-125a-5p could significantly downregulate its expression by binding to ERBB3 to inhibit proliferation and ERBB3 could at least partially mediate the inhibition of miR-125a-5p on the proliferation of head and neck cancer cells. CONCLUSION: The findings of this study suggested that the miR-125a-5p/ERBB3 axis might play a role in the proliferation, regulation of cell cycle, migration and apoptosis of head and neck cancer cells, potentially offering a new target for treatments of head and neck cancers.

Long noncoding RNA FOXD2-AS1 enhances chemotherapeutic resistance of laryngeal squamous cell carcinoma via STAT3 activation.

Laryngeal squamous cell carcinoma (LSCC) is a common head and neck cancer. Despite recently improved management of LSCC, chemotherapy resistance of patients remains a challenge. In this study, we identified that long noncoding RNA FOXD2-AS1 regulates LSCC therapeutic resistance by augmenting LSCC stemness. LSCC chemotherapy-resistant patients showed increased FOXD2-AS1 expression compared with that in chemotherapy-sensitive patients, which predicted poor prognosis. Gain- or loss-of-function experiments showed that upregulated FOXD2-AS1 maintained cancer stemness, reducing the response to chemotherapy, while FOXD2-AS1 downregulation had the opposite effects. FOXD2-AS1 acted as a scaffold for STAT3 and PRMT5, promoting STAT3 transcriptional activity, which is essential to maintain cancer stemness and promote chemotherapeutic resistance. Interfering with FOXD2-AS1 using short hairpin RNA rescued LSCC's chemotherapeutic sensitivity. Thus, FOXD2-AS1 promotes LSCC chemotherapeutic resistance and is an upstream activator of STAT3, making FOXD2-AS1 a potential therapeutic target to improve the chemotherapy effect in LSCC patients.

PLOD2 contributes to drug resistance in laryngeal cancer by promoting cancer stem cell-like characteristics.

BACKGROUND: Advanced stage laryngeal squamous cell carcinoma (LSCC) presents a poor prognosis; thus, there is a great need to identify novel prognostic molecular markers. Procollagen-lysine, 2-oxoglutarate 5-dioxygenase 2 (PLOD2) is thought to be a novel prognostic factor in several cancers, but its role in LSCC remains unknown. Cancer stem cells (CSCs) are responsible for most instances of tumor recurrence and the development of drug resistance and have been proven to be present in head and neck cancers. Our preliminary study indicated that PLOD2 was elevated in LSCC tissues; therefore, we hypothesized that PLOD2 is related to the prognosis of LSCC patients and aimed to explore the role and underlying mechanism of PLOD2 in LSCC. METHODS: We validated the prognostic role of PLOD2 in 114 LSCC patients by immunohistochemistry. Stable PLOD2-overexpressing Hep-2 and FaDu cells were established and assessed by molecular biology and biochemistry methods both in vitro and in vivo. RESULTS: We confirmed that PLOD2 overexpression was correlated with poor prognosis in LSCC patients. PLOD2 overexpression strengthened the CSC-like properties of Hep-2 and FaDu cells, activated the Wnt signaling pathway and conferred drug resistance in LSCC in vitro and in vivo. CONCLUSIONS: We found that PLOD2 could serve as a prognostic marker in patients with LSCC and confer drug resistance in LSCC by increasing CSC-like traits; in addition, a Wnt-responsive CSC pathway was identified.

[The long-term clinical efficacy of endoscopic surgery of primary sinonasal malignant neoplasms].

OBJECTIVE: To assess the long-term clinical efficacy of endoscopic surgery of primary sinonasal malignant neoplasms and find out the potential postoperative prognostic factors. METHOD: Forty-three clinical cases of primary sinonasal malignant neoplasms treated under endoscopy were analyzed retrospectively. RESULT: Fifteen patients died. The 1-year, 2-year, 3-year and 5-year survival rates were 83. 7% (36/43), 74. 4% (32/43), 69. 8% (30/43) and 65. 1% (28/43), respectively. Kaplan-Meier single-variable analysis showed that gender, T grade, TNM stage and pathological types of olfactory neuroblastoma were statistically significant prognostic factors (P< 0. 05). COX Pro-Portional hazard models showed that TNM stage was an independent prognostic factors. CONCLUSION: Endoscopic surgery for primary sinonasal malignant neoplasms is a safe and effective minimally invasive surgical treatment, and it is an important supplement to the traditional surgery. Gender, T grade, TNM stage and pathological types of olfactory neuroblastoma might be significant prognostic factors.

[Expression and its significance of CD44 in SP cells of nasopharyngeal carcinoma].

OBJECTIVE: Discussion of expression and its significance of CD44 in SP cells of nasopnaryngeal carcinoma. METHOD: Flow cytometry was used to sort cultured CNE-2 cells of nasopharyngeal carcinoma for obtaining CD44-SP and CD44+SP cells. Biological differences of CNE-2, CNE-2 SP, CNE-2 NSP, CNE-2 CD44+SP and CNE-2 CD44-SP cells were statistically analyzed by experiments such as cell migration experiments, plate clone formation assay, cell cycle analysis and sensitivity tests to chemotherapeutics. RESULT: Two point 3 perent of SP cells were extracted from CNE-2 cells of nasopharyngeal carcinoma, among which 36.5% was CD44+SP cells. Abilities of proliferation, cell migration and plate clone of CD44+SP cells were significantly higher than other cells (P < 0.01), and its tolerance to chemotherapeutics was significantly higher too (P < 0.01). CONCLUSION: The proportion of SP cells in nasopharyngeal carcinoma cells was small, but SP cells had strong activeness in the aspect of cell proliferation with a "seed" characteristic of tumor cells. As CD44+SP cells played an important role in proliferation and chemotherapy resistance of nasopharyngeal carcinoma, it indicated that CD44 can be one of the surface markers of SP cells of nasopharyngeal carcinoma.

[Progress on treatment of transverse patella fractures with tension band fixation].

Transverse fracture is the most common in patella fracture and tension band fixation is one of the most effective methods. Surgical wire tension band technique is simple, the use of materials is also simple, but it is not strong and difficult to promote. Kirschner tension band technique can get satisfactory reduction with reliable fixation, but it is easy to complicate with steel wire breakage and Kirschner loosening. Screw tension band technique inherits the traditional advantages of simple manipulation and reliable fixation, also overcomes the disadvantages of early activity limitations caused soft tissue irritation of tension band around knee, the slippage and breakage of internal fixation, and the technique can be popularized generally.

[The clinical application of modified rhytidectomy incision in superficial parotid tumor surgery].

OBJECTIVE: To evaluate the modified rhytidectomy incision in superficial parotidectomy. METHOD: Thirty-five patients with superficial parotid tumor were included in this study. A modified rhytidectomy incision often used in facial plastic surgery was used for superficial parotidectomy and subtotal superficial parotidectomy with preservation of facial nerve and great auricular nerve. The follow-up study included the exposed region, the cosmetic effect of this approach and the rate of complication. RESULT: All patients healed without salivary fistula, and were satisfied with this modified approach. Temporary paralysis of the marginal mandibular branch of facial nerve were found in five patients, and six patients felt insensible around earlobe after operation. They all recovered in 1 to 3 months after surgery, no recurrence was happened during follow-up in 36 to 60 months (median follow-up period was 48 months). CONCLUSION: The modified rhytidectomy incision provided good exposure, had less complication and better cosmetic outcome.

Endoscope-assisted versus conventional second branchial cleft cyst resection.

BACKGROUND: This study evaluates the feasibility of endoscope-assisted second branchial cleft cyst resection via retroauricular approach by comparing it with conventional cervical incision for removal of second branchial cleft cyst. METHODS: From January 2009 to December 2010, 25 patients were randomly assigned to the endoscope-assisted surgery group (13 patients) or the conventional surgery group (12 patients). The clinical characteristics of patients, operation time, operative bleeding volume, postoperative complications, and subjective satisfaction with incision scar checked by visual analog scale were compared between the groups, retrospectively. RESULTS: All 13 second branchial cleft cyst resections were successfully performed endoscopically, and the wounds healed uneventfully. Endoscope-assisted surgery lasted 54.6 ± 6.3 min, and conventional surgery lasted 49.6 ± 6.9 min (P = 0.069). Degree of bleeding volume did not differ between the groups (P = 0.624). Mean patient satisfaction score was 9.2 ± 0.6 in the endoscope-assisted surgery group and 6.2 ± 0.8 in the controls (P < 0.001). All 13 patients in the endoscope-assisted surgery group were satisfied with their cosmetic results. One case showed temporary numbness around the earlobe that recovered within 1 month after surgery. No marginal nerve palsy occurred. No complications such as bleeding, salivary fistula, or paresis of the marginal mandibular branch occurred. All 25 patients were disease free with follow-up of 6-24 months (median 16 months). CONCLUSIONS: Endoscope-assisted second branchial cleft cyst resection via retroauricular approach is a feasible technique. This procedure may serve as an alternative approach that allows an invisible incision and better cosmetic results.

[A comparison between endoscopic-assisted submandibular gland resection via retroauricular hairline incision and conventional submandibular gland resection].

OBJECTIVE: To assess the feasibility, the risks and the advantages of endoscope-assisted submandibular gland resection using a retroauricular hairline incision (RAHI) by comparing it with the conventional submandibular gland resection. METHODS: Twenty eight patients with benign lesions of the submandibular gland were included in the prospective clinically controlled study. Thirteen patients had endoscope-assisted resection using the RAHI approach and 15 cases had conventional transcervical approach resection. The size, location and adjacency of all lesions were evaluated by CT or MRI before surgery. The pathologic diagnoses of all cases were identified as benign diseases using fine needle aspiration biopsy. The two groups were compared for incision length, operation time, bleeding, incision cosmetic result, and complications. RESULTS: All 28 operations were successfully performed. Incision length in the endoscopic group was significantly longer than that in the transcervical group (Z = -4.516, P < 0.01), and the surgical time was longer in the endoscopic group (Z = -3.263, P < 0.01). After three months the mean subjective satisfaction score for the incision scar in the endoscopic group was significantly higher than that in the transcervical group (Z = -4.472, P < 0.01). In the endoscopic group, 2 cases (15.4%) with temporary numbness of the earlobe and 1 case (7.7%) with a temporary marginal mandibular nerve paralysis were found postoperatively. However, they recovered within 1 month. All 28 patients were disease free with a follow-up of 10 to 24 months (median of 18 months). CONCLUSIONS: Endoscope-assisted submandibular gland resection via RAHI is feasible and safe for the treatment of benign submandibular gland lesions. In comparison with the transcervical approach, this method can provide better cosmetic results without significant complications.

[Selective neck dissection for treating recurrent branchial anomalies].

OBJECTIVE: To evaluate the role of selective neck dissection in the treatment of recurrent branchial anomalies. METHOD: The clinical data of 18 patients with recurrent branchial anomalies were retrospectively analyzed. In accordance with the embryologic and anatomic features of branchial anomalies, different types of selective neck dissection were applied. With dissection and protection of important vessels, nerves and other structures, enbloc resection principles were applied to extirpate branchial lesions, scarrings and inflammatory granuloma during the operation. RESULT: Of all 18 patients, 16 cases were healed with primary healing, 2 cases with local incision infection were healed after dressing changes. A temporary facial nerve paralysis occurred in 1 case with recurrent first branchial cleft fistula postoperatively, and completely recovered 2 months after operation. A postoperative temporary vocal cord paralysis occurred in 1 case with recurrent fourth branchial cleft fistula, and totally recuperated 1 month after operation. No recurrences were found in all 18 cases with a follow-up period of 12-78 months (average 35 months). CONCLUSION: Selective neck dissection is a safe and effective surgical procedure for the radical treatment of recurrent branchial anomalies.

[Preliminary experience with endoscope-assisted transoral excision of the submandibular gland].

OBJECTIVE: To discuss the indications, risks and benefits of endoscope-assisted transoral approach to excise the submandibular gland. METHODS: A retrospective review of a series of 12 patients treated by endoscope-assisted transoral submandibular gland excision was carried out. Of the 12 patients, 8 were chronic sialoadenitis (2 cases with sialolith), 3 were pleomorphic adenoma, and 1 was cyst of submandibular gland. Preoperatively, all patients were diagnosed as benign diseases by Ultrasonography, CT or MRI. Pathologic diagnosis of 8 cases were identified by fine needle aspiration cytology (FNAC) or fine needle aspiration biopsy (FNAB). RESULTS: Temporary lingual sensory paresis and temporary limitation of tongue movement were found in two patients. However, these signs soon resolved spontaneously within 1 - 3 months. There were no other complications. Postoperatively, mean satisfaction score with cosmetic results was 10. All patients were satisfied with the cosmetic results. No recurrences were found in patients with pleomorphic adenoma with a follow-up period ranged from 12 months to 48 months (median follow-up period: 36 months). CONCLUSIONS: Endoscope-assisted transoral excision of the submandibular gland is a feasible and safe approach for the benign diseases of the submandibular gland. The major advantages of this approach are no external scar and no injury to the marginal mandibular nerve.

[The short duration functional electrical stimuli do not cause mRNA expression change of K(ATP) channel and acute inflammation cytokine in recurrent laryngeal nerve].

OBJECTIVE: To investigate whether the inflammation response and K(ATP) channel damage happened because of acute injury after functional electrical stimuli (FES) act on the recurrent laryngeal nerve (RLN). METHOD: Thirty rabbits were divided into 3 groups by 10 rabbits for each group. The unilateral RNL were stimulated by FES with cuff electrode in first group. There was electrode on the RNL without FES in second group. The third group was normal control. The electrical generator and isolation unit provide electrical stimulation to the RLN at 50 Hz, with 4 mA current, for 2ms pulse duration. The total train duration was 5 seconds (2 seconds on; 3 seconds off). The RLN were collected in 1 hour after 3 hours electrical stimuli. We measured mRNA expression of injury acute response inflammation cytokine IL-10, TGF-beta1, TNF-alpha and K(ATP) Subunit protein Kir6.1, Kir6.2, SUR2AB, using real-time reverse transcribed-polymerase chain reaction. PCR products were verified by electrophoresis in agarose gels. We investigated the vocal synchronic adductive movement with RLN FES by endoscopy. We investigated the nerve local RNL morphological burn. Data were analyzed with the One-way ANOVA analysis of SPSS version 13.0 for Windows. RESULT: There were no significance difference among three groups in mRNA expression of inflammation cytokines IL-10, TGF-beta1, TNF-alpha and K(ATP) channel protein Kir6.1, Kir6., SUR2AB. We did not find the nerve morphological burn in all rabbits RLN. The vocal synchronic adductive movement were normal during stimuli time. CONCLUSION: The short duration functional electrical stimuli do not cause mRNA expression change of K(ATP) channel and acute inflammation cytokine in recurrent laryngeal nerve.

[Diagnosis and treatment of congenital fourth branchial anomaly].

OBJECTIVE: To discuss the anatomic features, clinical presentations, diagnosis, differentiations and treatments of congenital fourth branchial anomaly(CFBA). METHODS: The clinical data of 8 patients with CFBA were retrospectively analyzed. RESULTS: Of the 8 patients aging from 27 to 300 months (median age: 114 months), 4 male and 4 female; 3 untreated previously and 5 recurrent. All lesions, including 1 cyst, 3 sinus (with internal opening) and 4 fistula, located in the left necks. Three patients presented acute suppurative thyroiditis, 4 deep neck abscesses, and 1 neck lump. Preoperative examinations included barium esophagogram, direct laryngoscopy, ultrasonography, CT, MRI, and so on. The principles of managements were adequate drainage, infection control during acute period and radical surgery during quiescent period. Classic surgical approach consisted of complete excision of branchial lesions, dissection of recurrent laryngeal nerve and partial thyroidectomy. Selective neck dissection was applied in recurrent cases to extirpate branchial lesions, scarrings and inflammatory granuloma. Postoperatively, 1 case was with local incision infection which healed by wound care; 1 case was with temporary vocal cord paralysis which completely recovered 1 month after operation. No recurrence was found in all of 8 cases with follow-up of 13 to 42 months (median: 21 months). CONCLUSIONS: CFBA relates closely anatomically with recurrent laryngeal nerve and thyroid grand. The barium esophagogram and direct laryngoscopy are the most useful diagnostic tools. CT and MRI are all beneficial to the diagnosis of CFBA. The treatment key to CFBA is the complete excision of lesion during a quiescent period after inflammatory control, together with the dissection of recurrent laryngeal nerve, partial thyroidectomy and partial resection of lamina of thyroid cartilage (if necessary), which all can decrease the risk of complications and recurrence. For recurrent cases, selective neck dissection is a safe and effective surgical procedure.

[Influence of blood supply of the esophageal and gastric stumps on anastomotic healing after esophagogastrostomy in rabbits].

OBJECTIVE: To study how blood supply of the esophageal and gastric stumps influences the anastomotic healing after esophagogastrostomy in rabbits. METHODS: Twenty-seven New Zealand rabbits were randomly divided into 3 groups to receive esophagogastrostomy, followed by different procedures. Except for those in group I, all the rabbits were subjected to procedures of reducing the blood supply either of the esophageal or the gastric stump (group II and group III, respectively), followed by single-layer esophagogastric anastomoses using interrupted 5-0 polypropylene sutures. Ten days after operation, all the rats were killed and the anastomotic sites excised for measurement of the inner diameter, tensile strength, and hydroxyproline concentration. RESULTS: Healing of the esophagograstric anastomosis was obtained in all the rabbits but one with anastomotic leakage in group I and one with perforation of the gastric fundus in group III. The anastomotic inner diameters were similar in all the three groups, whereas the tensile strength and hydroxyproline concentration at the anastomoses decreased in group III in comparison with the other two groups (P<0.05) that had similar measurements (P>0.05). CONCLUSIONS: Extended length of the free esophageal stump does not significantly affect anastomotic healing as decrease of blood supply in the gastric stump.