Objective To observe the leading effect of end-tidal pressure of carbon dioxide in artery ( PET CO2 ) on mechanical ventila-tion in New Zealand white rabbits, and to establish parameters for medical animal experiments in terms of hemodynamics, blood gas, blood glucose, electrolyte. Methods 31 anesthetized New Zealand rabbits were practiced tracheostomy tube and mechanical ventilation. Respira-tion rate was 40 breaths/min and tidal volume was adjusted so that PET CO2 was 29 mmHg. Invasive blood pressure, electrocardiogram and PET CO2 were monitored. Blood gas analysis, electrolyte, hemoglobin and blood glucose were tested. Results When PET CO2 was maintained at 29 mmHg, the results were as follows:PH (7.42 ±0.07), 95% confidenceinterval (7.40~7.45);PaCO2(38.5 ±5.8) mmHg, 95%confidenceinterval (36. 4~40. 6) mmHg;BE (1. 45 ± 2. 80) mmol/L,95% confidenceinterval (0. 43~2. 48) mmHg. Conclusion Moni-toring of PET CO2 is good to guide mechanical ventilation in New Zealand white rabbits.

Objective To illustrate more accurately the feasibility of DNA barcode technology in species identification in different geographical areas.Methods Four plague host animals were selected from three plague natural foci in Inner Mongolia for DNA barcode comparison,GC base content,codon preference and genetic distance calculation,and a phylogenetic tree was constructed.Results Compared between different foci of A llactaga sibirica,the difference of base content was statistically significant (F =5.34,P ＜ 0.05);the variation of Meriones unguiculatus focus Allactaga sibirica base content was larger,and compared with other foci Allactaga sibirica,the difference was statistically significant (all P ＜ 0.05).Different foci between one species rarely exist in codon sites.The genetic distance of intraspecific was less than 1％,and the genetic distance of interspecific was more than 18％.Conclusions DNA barcode of each species is specific,with no interspecific species sharing,and does not change with geographical position.Molecular identification of plague host animal is effective by DNA barcode.

Objective To analyze the risk factors for failures of intramedullary and extramedullary internal fixation in surgery of femoral intertrochanteric fractures in elderly patients.Methods A retrospective study was conducted of the 205 elderly patients with osteoporotic femoral intertrochanteric fracture who had accepted closed reduction together with intramedullary and extramedullary internal fixation between September 2005 and August 2014.They were 89 men and 116 women,from 65 to 98 year of age (average,78.8 years).By AO classification,137 cases were of types AI.1-A2.1 (stable fractures),and 68 of type A2.2-A3.3(unstable fractures).The incidence of internal fixation failure and Harris scores at the last follow-up were recorded.The factors possibly contributing to the failure were analyzed using the univariate analysis and multivariate logistic regression analysis.Results Of the patients,192 obtained a mean follow-up of 39 months (from 14 to 60 months),but 13 were lost after a 10-month follow-up.Of the 205 patients,internal fixation failure occurred in 12 (incidence of 5.9％).Five failed cases received DHS fixation and 7 accepted PENA fixation.At the last follow-up when the 13 cases were lost after 10-month follow-up,the mean Harris hip score was 81.6 (from 57 to 92),and the excellent to good rate was 84.9％ (29 excellent cases,145 good ones,10 fair ones and 21 poor ones).The multivariate regression analysis revealed that tip-apex distance (TAD) ＞ 25 mm(OR ＝ 333.33),severe osteoporosis (OR =267.44),AO types A2.2-A3.3 (OR ＝ 22.24),functional reduction of fracture (OR =20.79),and concomitant medical diseases (OR =4.59) were independent risk factors for failures of internal fixation.Conclusions DHS and PFNA fixations are effective treatments for elderly patients with femoral intertrochanteric fractures.TAD＞ 25 mm,severe osteoporosis,unstable factures,functional reduction of fracture,and concomitant medical diseases may lead to internal fixation failure in surgery of femoral intertrochanteric fractures in elderly patients.

Objective To determine a method for amplification of cytochrome C oxidase subunit Ⅰ (CO Ⅰ) gene of Brandt's vole.Methods 发he Brandt's Voles were captured in Abagaqi Xilingol League Inner Mongolia,and DNA was extracted from liver tissue.CO Ⅰ gene was amplified by nested PCR and sequenced afterwards.Results A band of 657 bp and 1 132 bp was amplified by internal and external PCR primers,respectively,which were consistent with expected sizes.A total of 12 segments of Brandt's Vole CO Ⅰ gene sequences were amplified by PCR and verified by sequencing.一he sequence number was KF182196-KF182207 in GenBank.After gene sequence alignment of the 12 CO Ⅰ gene sequences,it was found that the similarity was 100％,and no base mutation.Conclusion CO Ⅰ gene of Brandt's Vole could be amplified by nested PCR without pseudo gene.

A model of intrahepatic portal hypertension was established in SD rats by injection of carbon tetrachloride (CCl4). By observing the opening angle of the portal vein, the zero-stress state of the portal veins was studied at different time during the pathogenesis of intrahepatic portal hypertension. After CCl4 injection, the opening angles of the portal veins were increased, in the tenth week, they were much greater than those in the corresponding controls (P<0.05). The results suggest that during the pathogenesis of portal hypertension, unequal remodeling exists in the portal veins to change its biomechanical properties, and the residual stress and strain of the portal veins in portal hypertensive rats are greater than those in normal controls.
Animals ; Carbon Tetrachloride Poisoning ; Disease Models, Animal ; Hypertension, Portal ; chemically induced ; physiopathology ; Injections, Subcutaneous ; Male ; Portal Vein ; physiopathology ; Rats ; Rats, Sprague-Dawley ; Stress, Mechanical

Objective:To evaluate the clinical effect of striated free wrist transverse flap pedicled with superficial palmar branch of radial artery carrying sensory nerve in repairing pulp defect of middle-and-distal segments of fingers.Methods:From February 2019 to March 2021, the data of 20 patients with defects of middle-and-distal finger segment were collected. The defects were repaired with striated free wrist transverse flaps pedicled with superficial palmar branch of radial artery. The defects sized were 2.0 cm×1.5 cm-4.0 cm×1.5 cm, and the flaps sized were 2.5 cm×2.0 cm-4.5 cm×2.0 cm. The flap carried metacarpal cutaneous branch of median nerve for the reconstruction of the sensation of finger pulps. The donor sites were directly sutured. After operation, the patients were evaluated according to the shape, sensation and functional recovery of the repaired fingers through outpatient visits and reviews via WeChat.Results:All 20 flaps survived and the wounds healed well. All patients entered regular follow-up for 6-12(average, 8) months. The colour of the flaps was close to the finger skin, without bloating flaps. The flaps were soft in good shapes and function. TPD were 6-11 mm, at 8 mm in average. The scars at the donor sites were hidden and the wrist function was not affected. According to the Trial Evaluation Standard of Upper Limb Function of Hand Surgery Society of Chinese Medical Association, 16 patients were classified as excellent and 4 as good.Conclusion:The striated transverse wrist flap with radial artery palmar superficial branch and sensory nerve offers many advantages, such as a good texture, hidden donor site, convenient flap harvesting, good recovery of sensation, etc. More clinical studies and the promotion of the technique are expected.

Esophageal squamous cell carcinoma (ESCC) is one of the most common malignant tumors with a poor prognosis. 4-nitroquinoline-1-oxide (4NQO) is a water-soluble quinoline derivative that can successfully induce the production of squamous cell carcinoma in vivo. Establishing and optimizing experimental methods for 4NQO induced ESCC formation in mice can provide a more suitable in situ model for the study of ESCC.

Objective:To explore the clinical effect of a modified surgical procedure for replantation of severed digit-tips in Tamai zones I-II.Methods:From November 2019 to October 2022, the Department of Hand and Foot Microsurgery of the First Affiliated Hospital of Bengbu Medical College employed a modified procedure (to abandon the anatomically labelling of blood vessels and nerves after naked-eye debridement and fracture fixation, then perform the microscopic dissections and anastomoses of blood vessels and nerves, and the anastomosis of dorsal veins though an auxiliary small incision by the lateral nail fold of the severed digit-tip) to replant severed digit-tips in Tamai zones I-II of 26 patients (29 digits). The patients were 20 males (23 digits) and 6 females (6 digits), aged 3-66 years old, with mean age at 28 years old. Nineteen digit-tips were severed in Tamai zone I and 10 in Tamai zone II. The severed digit-tips were 7 of thumbs, 9 of index fingers, 5 of middle fingers, 5 of ring fingers and 3 of little fingers. Causes of injury were 12 of cut, 8 of crush and 6 of avulsion. Postoperative management included infection prevention, antispasmodic for 3 days and keeping in bed for 5 days. The time of surgery was recorded on all patients. Postoperative follow-ups were conducted at outpatient clinics for 6 to 12 months to observe the survival of digit-tips and the appearance, recovery of sensation and motor functions, strength of digits and patient satisfaction.Results:(1)The surgical time was about 1.0 hour for replantation of a severed digit-tip in Tamai zone I, while it took about 1.5 hours for those in Tamai zone II. (2)Survival rate and appearance: all 29 replanted digit-tips survived, except 2 in Tamai zone I which encountered venous occlusion and survived after small incision for bloodletting. Twenty-two digit-tips gained pulp fat pads with full digit pulps. Four avulsed digit-tips had mild atrophy of pulp. The 15 digit-tips severed in Tamai zone I were about 2 mm shorter than the healthy sides, but without deformity. One digit-tip had poor nail appearance due to preoperative fungal infection of nail bed. (3)Sensory recovery: with the British Medical Research Council (BMRC), 23 digit-tips recovered to S 3+, and 2 digit-tips of avulsion and 1 digit-tip of crush recovered to S 3. TPD of the replanted digit-tips were: 4-7 mm in those of cut injury; 6-8 mm in those of crush and 9-11 mm in those of avulsion. (4)Motion and digit strength: results of functional assessment according to the total active mobility standard promoted by China's Society for Surgery of the Hand were: 21 cases of excellent and 5 of good, without pain in digit pulp when pinching and griping. The mobility of the digits with replanted digit-tips of both Tamai zones I and II were close to that of the healthy sides. The motions of the digits with replanted digit-tips in Tamai zone I were close to the healthy sides and the 5 of those in Tamai zone II had 0° in extension and 2°-3° in flexion, due to the severed plane at distal interphalangeal joint. (5)Patient satisfaction: 25 patients were satisfied, however 1 patient was dissatisfied to the poor function of the distal interphalangeal joint due to the severed thumb-tip in Tamai zone II. Conclusion:Modified replantation procedure for severed digit-tip in Tamai zones I-II has significant achievement in cutting down the surgical time through a modified procedure of debridement and fracture fixation (tendon suture) by naked-eyes operation first, followed by dissections and anastomoses of the blood vessels and nerves under the surgical microscope. The auxiliary small incision by the lateral nail fold of digit-tip in Tamai zone I facilitates an exposure of a constant, healthy lateral nail fold vein. It enables the anastomosis with a high-quality vein, hence improves the success rate of replantation. The appearance and function of the replanted digit-tip are found better in the severed digit-tips of cut injury than those with injuries of avulsion and crush.