Central venous catheter-related infection: a prospective, observational study to assess the incidence rate at a teaching hospital in Argentina.

One hundred fifty-one central venous catheters (CVCs) were observed for development of infection. The infection rate was higher for CVCs with a duration of less than 6 days than for those with a longer duration. Our data suggest that scheduled replacement of CVCs is not necessary.     

Absence of all cyclovertical extraocular muscles in a child who has Apert syndrome.

A 6-month-old patient with Apert syndrome underwent strabismus surgery for a hypertropic eye. At surgery, the patient was found to have agenesis of all four cyclovertical muscles in one eye. Further investigation by computed tomography demonstrated absence of all four cyclovertical muscles in the fellow eye as well. A transposition procedure corrected the strabismus. While isolated aberrant or missing extraocular muscles are well documented in patients with craniofacial syndromes, bilateral absence of all four cyclovertical muscles, as demonstrated in this patient, poses unique treatment challenges.     

犬自体肺组织瓣修补食管壁部分缺损的可行性

目的:分析犬自体肺组织瓣修补食管壁部分缺损的可行性。方法:实验于2003-01/2004-11在中国医科大学附属第二医院动物实验室完成。选用健康成年杂种犬20只,按随机数字表法分为2组,即支架组和无支架组,每组10只。20只实验犬经右胸第5肋间进胸,于胸内中段食管处胸内食管侧壁制成长4cm,环1/2~2/3周径全层缺损。于相应部位选择适当的肺组织,制成带蒂类舌状肺组织瓣。两组均将肺组织瓣覆盖并缝合固定于食管缺损处,支架组于食管缺损内衬自扩性记忆合金支架(管腔直径2.0cm、长6.0cm)并固定。术后抗炎及营养支持治疗。观察实验犬术后情况,并于术后2,4,6,8,10和12周定期处死实验犬行组织学观察。结果:无支架组实验犬存活7只,其中1只犬存活>24个月;支架组存活6只。①实验犬术后一般情况:存活犬于术后均能正常经口进食,早期有进食后呕吐,再吃下呕吐食物的现象,以支架组明显。②组织学观察结果:术后2周,无支架组均可见替代物表面有胶原及炎性渗出物,边缘见1~2层鳞状上皮细胞;支架组除有无支架组基本表现外,可见支架固定良好,光镜下见网架压迫处有较多中性粒细胞浸润。4~6周,两组均可见替代物表面有新生的3~5层复层鳞状上皮细胞;支架组见支架已基本陷入黏膜层内。8~10周,两组均可见管腔表面有6~8层新生复层鳞状上皮细胞;支架组网架边缘瘢痕组织增生,支架完全被包裹,炎症较重的局部有细胞爬行中断现象或新生细胞层数较薄,多为一两层。结论:应用自体肺组织瓣修补食管壁部分缺损是可行的,但支架组支架对食管修补处组织刺激大,炎性反应重,瘢痕重,因此如何选择合适的支撑物是今后替代节段性食管缺损面临的重要问题。     

甲壳素微结晶分散体系的研制：一种新的甲壳素溶解环试验

目的:鉴定细菌是否分泌甲壳素酶,并分解利用甲壳素的经典方法是甲壳素缺刻试验,但其需时较长,结果不明显,为解决以上缺点,研制甲壳素微结晶分散体系,拟创造一种新的实验方法甲壳素溶解环试验,并探讨其影响因素。方法:实验于2005-04/2006-12在浙江省医学科学院医学生物工程研究所完成。①通过高温高压、超声等综合手段,制备乳白色的甲壳素微结晶分散体系,并进行透射电镜观察。②采用制备的甲壳素微结晶分散体系,制造甲壳素培养基,取副溶血弧菌和致病性大肠杆菌44815菌悬液106cfu/mL各1μL,分别注入甲壳素培养基中,37℃培养72h,如接种点周围出现明显的透明环,即为阳性,反之为阴性。③制备2%,1%,0.5%3种不同浓度的NaCl及相应8.0,7.0和6.0不同pH值组合的3种甲壳素培养基,分别接种副溶血弧菌菌悬液106cfu/mL各1μL,37℃培养72h后测量溶解环直径。④菌量和培养温度的影响:将3种浓度菌悬液(108,106和104cfu/mL)各1μL注入甲壳素培养基中,37℃培养72h;固定菌量(2.8×106cfu/mL)接种后,分别在40℃、37℃和25℃培养72h,测量溶解环直径。结果:①成功制备了甲壳素微结晶分散体系,甲壳素浓度为4%,微粒粒径<0.5μm。②培养72h后,接种副溶血弧菌甲壳素培基上呈现阳性反应。③在NaCl浓度为2.0%,pH为8.0环境条件下,溶解环直径最大。④在菌量108￣104cuf/mL范围内,菌量与溶解环直径大小呈正比,但最适浓度为106cuf/mL;在37℃环境中溶解环直径最大。结论:①甲壳素溶解环试验是鉴定细菌能否分泌甲壳素酶、并分解利用甲壳素的一种直观、快速、准确的方法。②甲壳素培养基NaCl、pH值、培养温度及菌量等对甲壳素溶解环试验均有直接的影响。     

Factors influencing collection and engraftment of CD34+ cells in patients with breast cancer following high-dose chemotherapy and autologous peripheral blood progenitor cell transplantation

Although autologous PBPC transplantation is being used increasingly for the treatment of breast cancer, there are few data on factors influencing mobilization and engraftment in these patients. We have analyzed these factors in 70 patients with advanced or metastatic breast cancer undergoing autologous PBPC transplantation. All patients were mobilized after stimulation with G-CSF, and a median of 3.16 x 10(6)/kg CD34+ cells (range 0.75-23.33) were infused. All patients received conditioning with a combination of cyclophosphamide, thiotepa, and carboplatin, and postinfusion G-CSF was administered to 60 patients. The median times to reach 0.5 x 10(9)/L and 1 x 10(9)/L neutrophils were 10 and 11 days, respectively. The median times to obtain 20 x 10(9)/L and 50 x 10(9)/L platelets were 12 and 18 days, respectively. An analysis of factors that influence CD34+ cell collection was performed by linear regression. Previous radiation therapy and increasing age were associated with lower numbers of CD34+ cells collected. Those variables that could influence the tempo of engraftment were examined by multivariate analysis using Cox regression models. The number of CD34+ cells infused was found to influence both neutrophil and platelet recovery. The use of G-CSF after transplant, accelerated neutrophil recovery, and having more than six cycles of previous chemotherapy was an unfavorable factor for recovering >50 x 10(9)/L platelets.     

Improvement of platelet storage conditions by using new polyolefin containers

BACKGROUND : Storage of pooled platelet concentrates (PCs) with yields above 3.0 × 10¹¹ platelets per unit in a 1-L PL-732 polyolefin container for 5 days often results in a drop in pH to below 6.0. Recently, new oxygen-permeable platelet containers (1-L PL-2410, 1-L and 1.5-L Compoflex) have been developed. The maximal platelet storage capacities of the new containers and the PL-732 were compared. STUDY DESIGN AND METHODS : Large platelet pools (n = 27) with platelet concentrations between 1.2 and 1.4 × 10¹¹ per L were made from 3 to 5 PCs prepared from buffy coats. The pools were divided in equal volumes among the PL-732 and the three new platelet containers. Platelet counts in the PCs ranged from 1.0 to 5.0 × 10¹¹ per unit. All PCs were stored on a flatbed shaker at 22 ± 2°C and evaluated on Days 1, 3, 5, and 7 by measuring platelet count, pH, pO₂, pCO₂, HCO₃-, glucose, lactate, platelet swirling, and soluble p-selectin. RESULTS : Day 7 storage of PCs (n = 6) with yields between 3.0 and 4.0 × 10¹¹ platelets in PL-732 showed mean ± SD pH values of 5.93 ± 0.05 and lactate values of 32.3 ± 7.9 mmol per L; in 4 of these 6 PCs, pH was below 6.0. In contrast, storage of these PCs in 1-L PL-2410 and 1.5-L Compoflex containers and of 2 of these 6 PCs in 1-L Compoflex containers showed pH values above 6.8. Lactate values were 15.5 ± 1.3, 15.3 ± 1.8, and 19.5 ± 4.7 mmol per L, respectively (p < 0.001 vs. PL-732). The platelet storage capacity of the new containers with platelet yields between 4.0 and 5.0 × 10¹¹ per unit (n = 6) was evaluated. Day 7 storage of these PCs in the 1.5-L Compoflex showed an average pH value of 6.74 ± 0.20; in 2 of 6 PCs, pH was below 6.8. The average pH value in the PL-2410 was 6.38 ± 0.31, and in all PCs, pH was below 6.8. Average lactate values were 17.8 ± 5.7 and 25.8 ± 5.6 mmol per L (p < 0.05), respectively. Soluble p-selectin values on Day 7 of storage increased approximately twofold in all PCs. CONCLUSION : The new oxygen-permeable containers showed platelet quality comparable to that with the PL-732 and for longer storage periods and at higher platelet counts.     

Risk factors associated with St. Louis encephalitis seroprevalence in two populations from Córdoba, Argentina

St. Louis encephalitis virus (SLEV) is endemic in Argentina. The first outbreak was recorded in Córdoba during the late summer of 2005. This study analyzes the association between social and demographic factors and other variables related to exposure to mosquitoes with SLEV infection in 264 individuals who attended two health centers in the city of Córdoba during the period December 2004-January 2005. Multiple logistic regression models were used to estimate the risk coefficients. The seroprevalence was 12.9%, similar to that in previous reports. Risks of infection were associated with the presence of garbage dumps near dwellings, the practice of outdoor activities at night and place of residence. Risk for older people (60-80 years old) was moderate. The identification of risk factors related to SLEV infection would be useful to improve programs for vector control and community health.     

Hymenolepis nana infection: symptoms and response to nitazoxanide in field conditions

A matched case-control study on clinical symptoms of Hymenolepis nana and an open trial of nitazoxanide treatment were conducted in a village on the northern coast of Peru. Interview data were obtained from 25 individuals with hymenolepiasis only and 46 matched controls. Individuals with other intestinal helminths or giardiasis were excluded. Twenty nitazoxanide-treated cases were followed with stool examination a month later. There were no significant differences between groups in the prevalence of symptoms except headache, which was less frequent in the cases. Treatment efficacy was 75%. Hymenolepiasis in this community did not have significant impact on specific symptoms.