Germline mutations of the p53 gene in children with malignant solid tumors

Although somatic mutations of p53 are the most common genetic changes observed to date, the frequency of germline p53 mutations is found to be very low in sporadic malignant tumors. It has been postulated that de novo germline p53 mutations may occur in a substantial population of patients in pediatric age group, who die of their disease and do not propagate the mutation. To determine the frequency and type of p53 germline mutations in pediatric patients, we screened 65 children who were consecutively admitted with primary malignant solid tumors.     

Dynamic susceptibility contrast MR imaging of plaque development in multiple sclerosis: application of an extended blood-brain barrier leakage correction

Since the pathogenesis of multiple sclerosis (MS) lesions is not yet fully understood, we investigated the potential of dynamic susceptibility contrast (DSC) magnetic resonance (MR) perfusion imaging for a better characterization of lesion pathology. Twenty-five MS patients were examined on a 1.5 T scanner. A single dose of gadolinium (Gd)-DOTA contrast agent was injected, and echoplanar images were acquired every 0.5 seconds for 1 minute. From the signal intensity-versus-time curves, the relative cerebral blood volume (rCBV) was evaluated for regions in plaques and in gray and white matter. The rCBV calculated for acute, Gd-enhancing plaques was corrected for the effects of blood-brain barrier leakage, using a new correction algorithm. Acute plaques had significantly higher blood volumes than normal-appearing white matter (P < = 0.01). Chronic plaques that appeared hypointense on T(1)-weighted images had lower rCBV than T(1)-isointense plaques (P < = 0.03). Our results indicate that the acute phase in MS is accompanied by vasodilation. In later stages of gliosis, the perfusion decreases with increasing axonal injury. Although the DSC technique is less sensitive than conventional MR imaging, the information provided is essentially different from that obtained with any other MR method.     

The mechanical properties of intact and traumatized epidural catheters

Comparative data on the mechanical properties of epidural catheters used clinically are not available. We performed a controlled laboratory investigation to assess the mechanical performance of three different intact or traumatized catheter types (Polyurethane, clear nylon, and radiopaque nylon catheters, designed for 18-gauge Tuohy needles). We studied a control (intact) and two trauma groups (needle bevel and surgical blade). Catheters were loaded to their breaking points by using a Lloyd LS500 material testing machine (Lloyd, Southampton, UK). Maximal load and extension values before breakage were measured, and modulus of elasticity and toughness values were calculated. Intact polyurethane catheters did not break within the limits of the experimental study (extension up to 3 times the original length of a specimen). The toughness values obtained from polyurethane and clear nylon catheters were significantly higher than those for the radiopaque catheters in intact specimens (P < 0.05). In the traumatized groups, polyurethane catheters had the highest toughness values (P < 0.05). Modulus of elasticity values were higher in both control and trauma groups of the radiopaque catheters when compared with the polyurethane and clear nylon catheters, which indicates a higher stiffness to elastic deformation (P < 0.05). In conclusion, polyurethane catheters are the most durable catheter type to tensile loading, either intact or traumatized. Mechanical properties can be used to predict complications related to the clinical use of these catheters. IMPLICATIONS: Using a computer-assisted material testing machine, we studied the mechanical properties of three different types of epidural catheters, either intact or traumatized, in a blinded, controlled study. This information may be vital to clinicians who implant epidural catheters by helping them choose a catheter that has the lowest probability of failure.     

The safety and efficacy of Isola-Galveston instrumentation and arthrodesis in the treatment of neuromuscular spinal deformities

BACKGROUND: Implant systems that realign and stabilize a deformed spine continue to evolve. The purpose of the study of this case series was to determine the safety and effectiveness of a system designed to integrate hook, wire, screw, and post anchors for the treatment of a wide spectrum of neuromuscular disorders associated with pelvic deformity or the potential for deformity. METHODS: Forty-seven consecutive patients who had a spinal deformity that was due to cerebral palsy or an upper motor-neuron cerebral palsy-like disease (thirty-one patients), myelomeningocele (nine), Duchenne muscular dystrophy (four), or other disorders (three) were managed with Isola-Galveston instrumentation and arthrodesis. The average age at the time of the operation was fourteen years and three months (range, five years and four months to twenty-three years and nine months). Eight patients (17 percent) had an additional anterior discectomy and arthrodesis without instrumentation, and three (6 percent) had an additional decancellation egg-shell osteotomy. The forty-seven patients were followed for an average of forty-seven months (range, twenty-four to 100 months). The complications were tabulated to assess the safety of the procedure, and the correction of each deformity was calculated to determine the efficacy. RESULTS: There were no deaths, acute wound infections, or serious neurological problems. Reoperation was necessary in five patients (11 percent). One reoperation was performed because of a delayed deep wound infection; one, because of delayed sterile drainage; and one, for a pseudarthrosis repair. The remaining two reoperations were done for removal of an implant because the cephalad portion had become prominent. In addition to the pseudarthrosis that required a reoperation, there were three possible pseudarthroses that did not require a reoperation (overall prevalence of pseudarthrosis, 9 percent). Postoperative bracing was used for eleven patients (23 percent); it did not influence the rate of pseudarthrosis or possible pseudarthrosis. The average preoperative scoliosis of 70 degrees was corrected to 24 degrees (a 66 percent correction) at the time of the latest follow-up, and the average preoperative pelvic obliquity of 27 degrees was corrected to 5 degrees (an 81 percent correction). A survey of the patients, parents, and caregivers indicated that 96 percent of them were satisfied or very satisfied with the result of the operation. CONCLUSIONS: Isola-Galveston instrumentation seems as safe and effective as other types of instrumentation that have been studied in comparable series in the literature. Isola-Galveston instrumentation is probably more effective for the correction of pelvic obliquity and the maintenance of correction. Only a posterior procedure is used, and the instrumentation appears to decrease the need for an additional anterior approach. Spinal hook, wire, screw, and post anchors have been successfully integrated into one posterior spinal implant system.     

An unusual case of epigastric heteropagus: parasite with a rudimentary heart

Parasitic or heterotopic conjoined twins are exceedingly rare, and these cases are referred to as "heteropagus" when there is a parasitic attachment in a nonduplicated fashion to any portion of the body. Epigastric heteropagus twinning refers to the attachment of the parasite to the epigastric region of the autosite. An unusual epigastric heteropagus case is presented with a rudimentary cardiopulmonary and also nearly complete gastrointestinal and genitourinary system of the parasite, and an organogenetic and vascular status of the previously reported cases are reviewed. The current case might be unique for the parasite having a cardiopulmonary development--although rudimentary--and this might be the reason that it has more complete organogenesis than the cases that have been presented previously in the literature.     

Vascular endothelial growth factor expressing mesenchymal stem cells improves cardiac function in chronic myocardial infarction in pigs

Transplantation of mesenchymal stem cells （MSCs） for myocardial reconstruction has shown promise in both animal models and human phase 1 clinical studies. Vascular endothelial growth factor （VEGF） is a strong therapeutic agent for treating ischaemia by inducing angiogenesis. The feasibility of ex vivo MSCs mediated gene transfer is documented. Matsumoto and colleagues have recently reported genetically engineered MSCs carrying VEGF165 delivery for revascularization in a model of acute myocardial infarction （MI）. The promising data from our laboratory in both angiogenesis and MSCs transplantation in cunicular heart model of acute MI have prompted us to attempt the combined and simultaneous application of the two strategies.     

Risk factors for early-onset, ventilator-associated pneumonia in critical care patients: selected multiresistant versus nonresistant bacteria

BACKGROUND: Ventilator-associated pneumonia is the leading nosocomial infection in critically ill patients. The frequency of ventilator-associated pneumonia caused by multidrug-resistant bacteria has increased in recent years, and these pathogens cause most of the deaths attributable to pneumonia. The authors, therefore, evaluated factors associated with selected multidrug-resistant ventilator-associated pneumonia in critical care patients. METHODS: The authors prospectively recorded potential risk factors at the time of intensive care unit admission. An endotracheal aspirate was obtained in all patients who met clinical criteria for pneumonia. Patients were considered to have ventilator-associated pneumonia only when they met the clinical criteria and aspirate culture was positive for bacteria 48 h or more after initiation of mechanical ventilation. Pediatric patients were excluded. Adult patients with ventilator-associated pneumonia were first grouped as "early-onset" (< 5 days) and "late-onset," determined by episodes of ventilator-associated pneumonia, and then, assigned to four groups based on the bacteria cultured from their tracheal aspirates: Pseudomonas aeruginosa, Acinetobacter baumanii, methicillin-resistant staphylococci, and all others. The first three bacteria were considered to be multidrug resistant, whereas the others were considered to be antibiotic susceptible. Potential risk factors were evaluated with use of univariate statistics and multivariate regression. RESULTS: Among 486 consecutive patients admitted during the study, 260 adults underwent mechanical ventilation for more than 48 h. Eighty-one patients (31%) experienced 99 episodes of ventilator-associated pneumonia, including Pseudomonas(33 episodes), methicillin-resistant staphylococci (17 episodes), Acinetobacter(9 episodes), and nonresistant bacteria (40 episodes). Sixty-six of these episodes were early onset and 33 episodes were late onset. Logistic regression analysis identified three factors significantly associated with early-onset ventilator-associated pneumonia caused by any one of the multidrug-resistant bacterial strains: emergency intubation (odds ratio, 6.4; 95% confidence interval, 2.0-20.2), aspiration (odds ratio, 12.7; 95% confidence interval, 2.4-64.6), and Glasgow coma score of 9 or less (odds ratio, 3.9; 95% confidence interval, 1.3-11.3). A. baumanii-related pneumonia cases were found to be significantly associated with two of these factors: aspiration (odds ratio, 14.2; 95% confidence interval, 1.5-133.8) and Glasgow coma score (odds ratio, 6.0; 95% confidence interval, 1.1-32.6). CONCLUSIONS: The authors recommend that patients undergoing emergency intubation or aspiration or who have a Glasgow coma score of 9 or less be monitored especially closely for early-onset multidrug-resistant pneumonia. The occurrence of aspiration and a Glasgow coma score of 9 or less are especially associated with pneumonia caused by A. baumanii.     

香榧假种皮中紫杉醇的检定

目的:检定香榧假种皮中紫杉醇.方法:以乙醇、乙酸丁酯、氯仿为溶剂,采用溶剂直接浸取和索氏提取两种方法萃取香榧假种皮,提取物经萃取纯化后,通过HPLC测定其中的紫杉醇含量,通过流动注射质谱检测其中是否含有紫杉醇类似物.结果:香榧假种皮中紫杉醇含量少于0.003%,提取物中紫杉醇类物质的含量非常少.结论:香榧假种皮作为紫杉醇药源的开发价值不大.     

复方丹参胶囊质量控制标准研究

采用 TLC法鉴别复方丹参胶囊中高原丹参、三七及冰片 ;利用薄层扫描法测定高原丹参中丹参酮 A的含量 :甲醇提取液点样 ,石油醚 -醋酸乙酯 -冰醋酸 ( 8∶ 2∶ 0 .5)展开两次 ,4 80 nm扫描法测定。 5批样品每粒胶囊均含丹参酮 A0 .4 59～ 0 .557mg。