What Can Be Expected of Balloon Aortic Valvuloplasty in Adults?

Introduced more than 15 years ago, balloon aortic valvuloplasty (BAV) has clearly delineated indications and limitations. Although, aortic valve replacement is undoubtedly the treatment of choice for healthy patients with aortic stenosis, BAV has been demonstrated as a valuable and safe palliative procedure for patients considered too risky or old for current day surgery. Between January 1991 and December 1999, 858 patients (mean age 76 ± 11 years, 479 [57%] women) underwent BAV at our center. Indications for BAV were contraindication to surgery in 16.2% of the patients, high risk in 40.4%, refusal of surgery in 10.7%, personal decision in 18.5%, and other in 14.2%. The mean gradient decreased from 65 ± 23 to 27 ± 12 mmHg and the valve area increased from 0.56 ± 0.19 cm² to 1.0 ± 0.38 cm². Eleven (1.1%) patients died during the procedure. The other severe complications were complete AV block in 18 (1.8%) patients, stroke in 8 (0.8%), tamponade in 6 (0.6%), and massive aortic insufficiency in 4 (0.4%). In conclusion, BAV does not replace valve replacement, even in the elderly. All those who can be operated on, should be. However, if surgical intervention is not considered reasonable, BAV offers good immediate results with an acceptable complication rate. Furthermore, previous published series have demonstrated that BAV is particularly indicated in specific subgroups, such as very old patients with high operative risk, end-stage heart failure, cardiogenic shock, or general anesthesia for noncardiac surgery.     

Volumetric rendering of MR images

The authors developed new techniques for three-dimensional display of magnetic resonance (MR) images that preserve soft-tissue definition, are fully automatic, and work with routinely used section thicknesses. MR images are segmented, selectively enhanced, and displayed by means of a volumetric rendering algorithm. These techniques were used to illustrate normal anatomy of the brain, knee, and liver. Three-dimensional rendering of balanced spin-echo images shows the ventricles and extracerebral veins and of T1-weighted images, the sulci and gyri. The large hepatic and portal vessels can be seen with these enhancement techniques. Three-dimensional views of the knee reveal articular surfaces of the tibia and clearly depict menisci and posterior and anterior cruciate ligaments. These techniques make it possible to image multiple soft tissues simultaneously while preserving the detail contained in the original images. Three-dimensional presentation of complex, overlapping anatomic regions is helpful in surgical planning and should lead to improved diagnosis.     

Anesthesia for children in Sub-Saharan Africa – a description of settings, common presenting conditions, techniques and outcomes

Anesthesia in developing countries deserves special attention. The most common technique is general anesthesia (with spontaneous or manually assisted ventilation). Nonmedical anesthetists with limited training and supervision and lacking the most common drugs and anesthetic equipment administer anesthesia, usually for emergency surgery. There are important safety issues, especially for pediatric anesthesia. Regarding pediatric surgery, the major workload is due to abdominal emergencies, mainly neonatal bowel obstruction or peritonitis due to typhoid perforation. The morbidity and mortality rate for these conditions is high.     

Cell tracking technologies for acute ischemic brain injury

Stem cell therapy has showed considerable potential in the treatment of stroke over the last decade. In order that these therapies may be optimized, the relative benefits of growth factor release, immunomodulation, and direct tissue replacement by therapeutic stem cells are widely under investigation. Fundamental to the progress of this research are effective imaging techniques that enable cell tracking in vivo. Direct analysis of the benefit of cell therapy includes the study of cell migration, localization, division and/or differentiation, and survival. This review explores the various imaging tools currently used in clinics and laboratories, addressing image resolution, long-term cell monitoring, imaging agents/isotopes, as well as safety and costs associated with each technique. Finally, burgeoning tracking techniques are discussed, with emphasis on multimodal imaging.     

VJ REARRANGEMENTS OF THE TCRγ LOCUS IN PERIPHERAL T-CELL LYMPHOMAS: ANALYSIS BY POLYMERASE CHAIN REACTION AND DENATURING GRADIENT GEL ELECTROPHORESIS

Using Southern blotting for the diagnosis of clonality in peripheral T-cell lymphomas (PTCLs), analysis of the T-cell receptor (TCR) γ gene rearrangement was shown to be more informative than that of the TCR β gene rearrangement. In order to amplify every VJγ rearrangement, a polymerase chain reaction (PCR) procedure using newly designed GC-clamp primers has been developed. All primers can be mixed in a single multiplex PCR. PCR products are analysed by denaturing gradient gel electrophoresis (DGGE), providing tumour-specific imprints inasmuch as the procedure characterizes N sequence polymorphism at the VJ junctions. In a series of 30 PTCL cases, the PCR procedure demonstrated 27 cases to be clonally rearranged and failed in three cases. PCR was more accurate than Southern blotting, showing 47 rearranged γ alleles, four of which were undetectable on the Southern blot. When lymphomas were studied at different sites and at relapse, the DGGE pattern remained unchanged. In PTCL, the proposed PCR is helpful for the diagnosis and staging of the disease and should improve the follow-up monitoring. The undetectability of clonal rearrangements in a few cases is discussed in the light of concepts of lymphomagenesis and T-cell differentiation.     

Nosocomial respiratory syncytial virus infection in Canadian pediatric hospitals: a Pediatric Investigators Collaborative Network on Infections in Canada Study

OBJECTIVE: To determine nosocomial transmission of respiratory syncytial virus (RSV) in Canadian pediatric hospitals, outcomes associated with nosocomial disease, and infection control practices. DESIGN: A prospective cohort study in the 1992 to 1994 winter respiratory seasons. SETTING: Nine Canadian pediatric university-affiliated hospitals. PARTICIPANTS: Hospitalized children with symptoms of lower respiratory tract infection (at least one of cough, wheezing, dyspnea, tachypnea, and apnea) and RSV antigen identified in a nasopharyngeal aspirate. RESULTS: Of 1516 children, 91 (6%) had nosocomial RSV (NRSV), defined as symptoms of lower respiratory tract infection and RSV antigen beginning >72 hours after admission. The nosocomial ratio (NRSV/[com-munity-acquired RSV {CARSV})] + NRSV) varied by site from 2.8% to 13%. The median length of stay attributable to RSV for community-acquired illness was 5 days, but 10 days for nosocomial illness. Four children with NRSV (4. 4%) died within 2 weeks of infection, compared with 6 (0.42%) with CARSV (relative risk = 10.4, 95% confidence interval: 3.0, 36.4). All sites isolated RSV-positive patients in single rooms or cohorted them. In a multivariate model, no particular isolation policy was associated with decreased nosocomial ratio, but gowning to enter the room was associated with increased risk of RSV transmission (incidence rate ratio 2.81; confidence interval: 1.65, 4.77). CONCLUSIONS: RSV transmission risk in Canadian pediatric hospitals is generally low. Although use of barrier methods varies, all sites cohort or isolate RSV-positive patients in single rooms. Children with risk factors for severe disease who acquire infection nosocomially have prolonged stays and excess mortality.     

Evidence that large granular lymphocytes from B-CLL patients with hypogammaglobulinemia down-regulate B-cell immunoglobulin synthesis [published erratum appears in Blood 1989 Jun;73(8):2232]

B-chronic lymphocytic leukemia (CLL) patients frequently suffer from moderate to severe hypogammaglobulinemia. This complication is a serious cause of morbidity and mortality in this disorder. There is recent evidence that natural killer (NK) cells modulate B-cell immunoglobin (Ig) synthesis/secretion. The authors therefore evaluated the circulating NK cells from B-CLL patients on their ability to regulate mitogen-induced B-cell Ig synthesis. Blood, NK cells (CD16+, CD3-) from three B-CLL patients with hypogammaglobulinemia were able to clearly down-regulate the pokeweed mitogen (PWM)-induced-B-cell Ig secretion. In contrast, CD16+, CD3- cells from age-sex-matched controls or B-CLL patients with normal Ig were either nonregulatory or enhanced mitogen-induced B-cell Ig secretion. An alternative explanation for hypogammaglobulinemia in B-CLL patients is the immunomodulation of B- cell Ig production/secretion by CD16+, CD3- blood cells.     

003 胺碘酮可作为心房纤颤转复为窦性心律的首选药物

在美国,胺碘酮仅被批准用于治疗致命性室性心律失常,而在其他国家,尤其是南欧,也被广泛用于心房纤颤(Af)的治疗。然而有关胺碘酮复律效果报道不一,其成功率在16％～92％。本文前瞻性随机对照研究胺碘酮作为Af复律的首选药物的疗效及安全性。 连续208例症状性Af,男性102例,女性106例,年龄27～78(65±10)岁。将受试者随机分为胺碘酮治疗组与安慰剂组。胺碘酮用法：300mg静脉注射,持续1小时,然后以20mg/kg静脉滴注,持续24小时,继之口服200mg,tid,共1周,400mg/d共3周。如果受试者此前未用地高辛,则给予地高辛0.5mg静脉注射,2小时后再静脉注射0.25mg,继之静脉注射0.25mg,q6h,共24小时,此后调整地高辛剂量以维持治疗剂量的血清浓度,对Af持续48小时以上或持续时间不明、未用抗凝药物者均应用醋硝香豆素(acenocoumaro1),至少21天,复律成功者继续用药21天,未成功者用药时间不定。本研究将Af持续1个月以上者定义为慢性Af,＜24小时者定义为新近发作Af,其余定义为持续性Af。     

Detection and viability of tumor cells in peripheral blood stem cell collections from breast cancer patients using immunocytochemical and clonogenic assay techniques [see comments]

Although peripheral blood stem cell collections (PBSC) are thought to have less tumor involvement than bone marrow (BM), the incidence of circulating tumor cells in patients with breast cancer has not been widely investigated. We prospectively investigated the incidence and viability of tumor cell involvement in PBSC and BM collections from breast cancer patients undergoing high-dose chemotherapy/hematopoietic stem cell transplantation. Paired samples of PBSC and BM from 48 patients were analyzed using an immunocytochemical technique that detects one epithelial-derived tumor cell per 5 x 10(5) mononuclear cells. Immunostained tumor cells were detected in 9.8% (13/133) PBSC specimens from 9/48 (18.7%) patients and in 62.3% (38/61) BM specimens from 32/48 (66.7%) patients, a significantly higher rate than in PBSC (P < .005). The geometric mean concentration of tumor cells in contaminated PBSC specimens was 0.8/10(5) mononuclear cells (range 0.33 to 2.0/10(5)) compared with 22.9/10(5) mononuclear cells in BM (range 1 to 3,000/10(5), P < .0001). In culture experiments, clonogenic tumor colonies grew in 21/26 immunocytochemically positive specimens. No tumor colony growth was detected in 30/32 immunocytochemically negative specimens. Immunocytochemical detection of tumor involvement in BM and PBSC correlated significantly with in vitro clonogenic growth (P < .0001). We conclude that PBSC contain fewer tumor cells than paired BM specimens from patients with advanced breast cancer and that these tumor cells appear to be capable of clonogenic growth in vitro.