湿性医疗技术在创面处理中的应用

[概述]创面生理性愈合仍是当今国际医学界的一个棘手问题.目前, 创面处理的方法随着细胞生物学与生物活性因子学的发展发生了根本性变化, 对创面愈合机理也有了更深入的研究.创面形成的原因包括外源性损伤因素, 如急、慢性机械性损伤, 物理性或化学性烧伤, 冻疮, 感染或毒素, 内源性损伤因素如基因变异、血管病变、自身免疫性疾病、代谢紊乱、癌变或身心疾病等.     

Initial experience of using intracardiac echocardiography (ICE) for guiding balloon mitral valvuloplasty (BMV)

Background and aimsBMV is an established treatment for rheumatic mitral valve stenosis. The procedure is historically guided by fluoroscopy, and the role of intracardiac echocardiogram (ICE) guidance is not well defined. We report our initial experience of using ICE to guide BMV procedures.MethodsDuring BMV procedure, ICE catheter was inserted into the right atrium from the right femoral vein, and the septal puncture was monitored by ICE, as well as positioning of the balloon in the mitral valve. Comparisons were made between ICE, transthoracic echocardiography (TTE), and catheterization derived hemodynamic measurements (cath).ResultsSeventeen patients with mitral stenosis underwent the procedure. The mean age was 44.4 ± 21 years. The mean MV area increased from 0.9 ± 0.1 cm² to 1.7 ± 0.2 cm², P < 0.0001 and the mean gradient decreased from 12.6 ± 5.8 mmHg to 4.9 ± 1.8 mmHg, P < 0.001. Atrial septum puncture and guidance of the balloon into the MV apparatus were obtained in all patients under ICE guidance. Severe MR developed in one patient and was readily detected by ICE. ICE derived gradient measurements were comparable to those obtained by TTE, and cath.ConclusionICE guidance of BMV is feasible, and useful in monitoring safe septal puncture, optimizing balloon positioning, and in detecting complications. The hemodynamic measurements obtained were comparable to those obtained by TTE, and cath.     

Human T-lymphotropic virus type I and type II infections and correlation with risk factors in blood donors from Sao Paulo, Brazil

BACKGROUND: Little is known about the prevalence of and risk factors for human T-lymphotropic virus type I and type II (HTLV-I, HTLV-II) infections in Brazil. STUDY DESIGN AND METHODS: Sera from 17,063 healthy Brazilian donors were screened by enzyme-linked immunosorbent assay for antibody to HTLV-I/II between August 1991 and July 1993. Repeatedly reactive samples were confirmed by Western blot, and discrimination between HTLV-I and HTLV-II was made by polymerase chain reaction or synthetic peptide enzyme-linked immunosorbent assay. A univariate analysis was performed on demographic and serologic data. RESULTS: HTLV-I infection was demonstrated in 83 percent of the 30 donors with reactive serologic tests (0.15% of the total tested [17,063]; 95% CI, 0.09-0.20) and HTLV-II infection in 17 percent (0.03% of the total tested [17,063]; 95% CI, 0.01-0.05). HTLV-I-positive donors were more likely than reference groups to be of Asian ethnicity (odds ratio [OR] 15.1; reference group: whites), more than 50 years old (OR 4.2; reference group: 20–29 years old), and positive for antibody to hepatitis C virus (anti-HCV) (OR 21.8) or to hepatitis B core (antigen) (anti-HBc) (OR 5.7). HTLV-II showed a significant association with anti-HCV (OR 75.2) and anti-HBc (OR 21.8). Eleven of the 25 HTLV-I- positive donors were counseled. Family origin in endemic areas of Japan (n = 4), prior blood transfusion (n = 3), or sexual contact with prostitutes (n = 1) were the risk factors reported by 8 donors. In 3 white men, no risk factors could be identified. CONCLUSION: Both HTLV-I and HTLV-II occur among Brazilian blood donors. HTLV-I is associated with Asian ethnicity, greater age, and the presence of anti-HCV and anti-HBc. Three HTLV-I-positive donors had a history of blood transfusion, which emphasizes the need for HTLV-I/II screening in Brazil.     

Haemodynamic parameters predicting variceal haemorrhage and survival in alcoholic cirrhosis

The relationship between the various haemodynamic abnormalities observed in cirrhosis and their prognostic value remains unclear. We report haemodynamic measurements on 96 patients with alcoholic cirrhosis (mean Childs-Pugh Score, CPS, 9.0 +/- 0.2, mean age 55.6 +/- 1.0 years) and assess their value in predicting variceal bleeding and death during a mean follow-up of 19.3 +/- 1.5 months. Baseline CPS correlated with hepatic venous pressure gradient (HVPG) (p = 0.001), azygos blood flow (p < 0.05), cardiac index (p < 0.05), and inversely with mean arterial pressure (p < 0.01) and systemic vascular resistance index (p < 0.05). Renal blood flow was not related to any haemodynamic parameter or CPS. Thirty-eight patients died during follow-up, and 16 had a variceal bleed. Death (p = 0.001) and variceal bleeding (p < 0.05) were more likely in patients with HVPG > 16 mmHg than in those with HVPG < 16 mmHg, and variceal bleeding was more likely in patients with HVPG > 12 mmHg (vs. HVPG < 12 mmHg, p < 0.05). HVPG also predicted death and variceal haemorrhage on univariate and multivariate analyses. No other haemodynamic parameter predicted death or bleeding. In alcoholic cirrhosis, severity of liver disease is related to HVPG, collateral blood flow and degree of systemic circulatory abnormalities. HVPG is a useful predictor of survival and variceal bleeding in these patients.      

Specific antibodies to Trypanosoma cruzi among blood donors in Los Angeles, California

BACKGROUND: Trypanosoma cruzi, the cause of Chagas' disease, is often transmitted by transfusion in Latin America. Previous studies showed that at least 1 in 1000 eligible blood donors at the Los Angeles County+University of Southern California (LAC+USC) Medical Center Blood Bank had specific antibodies to T. cruzi. In June 1993, serologic screening of prospective allogeneic donors at epidemiologic risk for T. cruzi infection was begun voluntarily. STUDY DESIGN AND METHODS: The risk of T. cruzi infection in all eligible donors was assessed by questionnaire. At-risk donors were screened serologically for antibodies to T. cruzi with an enzyme immunoassay, and confirmatory testing was done with a radioimmunoprecipitation assay. RESULTS: During the 29-month study period 1311 (39.5%) of 3320 donors were judged to be at risk for T. cruzi infection. Seven donors (1/475) were reactive by an enzyme immunoassay, and six of these seven (1/ 553) were positive in a radioimmunoprecipitation assay. All radioimmunoprecipitation assay- positive donors had been born in countries in which Chagas' disease is endemic. One person in this group had received a transfusion in his homeland. CONCLUSION: These results demonstrate that a substantive proportion of eligible blood donors at our institution have antibodies specific for T. cruzi and that a commercially available assay can be used to detect these antibodies. Our data suggest that the risk of transmission of T. cruzi by transfusion could be eliminated by serologic testing limited to persons born in or transfused in countries in which Chagas' disease is endemic.     

HLA antigens in Omani patients with vitiligo

Fifty native Omanis with vitiligo were studied to compare the incidence of HLA ABC and DR antigens with a control population. HLA Bw6 was found in 82% of patients compared with 49% controls (P_c= 0.0009 RR = 4.56) and HLA DR7 occurred in 40% of patients and 9% in controls (P_c= 0.00075 RR = 6.17). HLA DR7 was significantly increased in those patients with acrofacial, compared to focal disease (57% vs. 24%P= 0.038). Sixty-six per cent of the patients in this study had parents who were consanguineous and a positive family history was only found in this group with an incidence of 32%. HLA Bw4 segregated 100% with patients with a positive family history compared with 48% in consanguineous patients without a positive family history (P_c= 0.011 RR = 23). Vitiligo appears to be associated with different HLA antigens in different ethnic groups.     

Acceleration of full-thickness wound healing in normal rats by the synthetic thrombin peptide, TP508

Thrombin is an essential factor in hemostasis, inflammation, and tissue repair. The synthetic thrombin peptide, TP508, binds to high-affinity thrombin receptors and mimics cellular effects of thrombin at sites of tissue injury. Treatment of full-thickness excisional wounds in normal rats with a single topical application of 0.1 microg TP508 (14 pmol/cm2) reproducibly accelerates wound closure, yielding wounds that on average close 39% more than controls by day 7 (p < 0.001). Wounds treated with 1.0 microg TP508 are 35% and 43% (p < 0.001) smaller than controls on day 7 and 10, respectively. The early rate of closure is approximately 40% greater in TP508-treated than vehicle-treated wounds (20 versus 14 mm2/day) and remains higher through day 7. Breaking strength after closure is slightly greater (15-23%) in wounds treated with TP508 than with saline alone. Histologic comparisons show that TP508 enhances recruitment of inflammatory cells to the wound site within 24 hours post-injury. TP508 treatment also augments revascularization of injured tissue, as evidenced at day 7 by the larger size of functional vessels in the granulation tissue and by the directed development of blood vessels to wounds. These studies raise the possibility that TP508 may be clinically useful in management of open wounds.     

低氧调节途径的分子生物学基础(低氧可作为肿瘤治疗的一种靶目标)

作者以综述形式论述了肿瘤低氧调节途径的分子生物学基础,并分析了利用低氧调节途径的阻断来治疗肿瘤的几种可行性途径。低氧可导致机体的一系列反应,包括糖酵解、红细胞生成、血管生成、肾上腺素信号传导的改变和血管内皮细胞的增殖等。肿瘤细胞的低氧可导致肿瘤新生血管的形成、浸润性增强、放射敏感性降低、预后变差。而肿瘤细胞又和正常细胞一样,都存在着“氧感应”途径,即低氧通过“血素氧化还原酶”激活氧信号传导系统,导致一系列低氧调节基因的表达。已知的低氧调节基因有:红细胞生成素(ＥＰＯ)、血管内皮生长因子(ＶＥＧＦ)、糖酵解…     

The combinatorial use of propofol-fentanyl-ketamine for sedoanalgesia in patients undergoing urological procedures

Objectives:To compare sedoanalgesia achieved using propofol-fentanyl-ketamine (PFK) combination with general anesthesia (GA) in terms of safety, hemodynamic stability, and perioperative complications.Methods:Patients in the GA group were anesthetized using fentanyl (2 μg kg-1) and propofol (2 mg kg-1). The PFK group was anesthetized using a mixture of which each one ml contains 0.005 mg of fentanyl, 5 mg of propofol, 5 mg of ketamine, and 2 mg of lidocaine. Patients received an initial dose of 0.05 ml kg-1, followed by 0.05 mg kg-1 60 seconds later. Maintenance boluses of 0.025 ml kg-1 were administered every 3-5 minutes. Respiration occurred spontaneously through a simple face mask with 3 L min-1 O₂.Results:The GA group had 37 (37%) patients develop hypotensive episodes, compared to one (1%) episode in the PFK group (p<0.001). Five (5%) patients in the PFK group had an episode of transient O₂ desaturation, compared to one (1%) patient in the GA group (p=0.212). The duration of induction and termination of anesthesia were significantly shorter in the PFK group (p<0.001).Conclusion:The PFK combination herein described is safe, effective, and provides intraoperative hemodynamic stability in patients with multiple comorbidities undergoing urological procedures.