Excretory urography with iohexol: evaluation in children

A multicenter clinical study was conducted using iohexol, a second-generation nonionic contrast medium, for excretory urography performed in 130 children. Doses of iohexol (300 mg iodine/ml) ranged between 150 and 660 mgI/kg (0.5 and 2.2 ml/kg). Iohexol was tolerated well, and no significant adverse reactions occurred. Sixty-five iohexol urograms were evaluated to determine the minimum dose for adequate visualization of the kidneys and collecting systems. A dose greater than 300 mgI/kg (1.0 ml/kg) always resulted in a urogram of diagnostic quality, while visualization was insufficient for diagnosis in 10% of studies done with doses of 150-300 mgI/kg (0.5-1.0 ml/kg). Another 65 iohexol urograms were compared in a blinded manner with a similar number of studies performed using iothalamate meglumine at comparable iodine concentration and dose. Visualization of calyces and pelvoinfundibular structures achieved with iohexol was rated better with statistical significance, but there was no difference in visualization of the renal parenchyma or ureters. Use of iohexol in excretory urography may be advantageous in children who are at greatest risk for an adverse reaction to contrast media or in those most likely to benefit from use of a low osmolality contrast agent.     

N-乙酰半胱氨酸对脑死亡状态巴马小型猪肾脏结构、功能与核转录因子κB表达的影响

目的：观察核转录因子κB活性抑制剂N-乙酰半胱氨酸对脑死亡状态下巴马小型猪肾脏结构、功能与核转录因子κB mRNA其蛋白表达的影响，以期提高脑死亡供肾的肾移植效果。方法：实验于2003—08／2004—12在河南省实验动物中心及河南省病理学重点实验室完成。①实验分组及方法：将15只巴马小型猪按随机数字表法分为3组（n=5），即脑死亡组、N-乙酰半胱氨酸组及对照组。脑死亡组和N-乙酰半胱氨酸组均应用改进的缓慢间断颅内加压法建立脑死亡模型，脑死亡组不行药物干预；N-乙酰半胱氨酸组分别于初次确认脑死亡后1h，12h给予N-乙酰半胱氨酸。对照组动物麻醉后仅行开颅与开关腹手术。②实验评估：分别于首次判定脑死亡后3，6，12，18和24h检测动物血清中尿素氮、肌酐、白细胞介素1β、白细胞介素6、肿瘤坏死因子α水平。于脑死亡后3，6，12及24h开腹取相同部位肾组织，苏木精-伊红染色后观察肾组织结构变化，应用免疫组化染色观察核转录因子κB蛋白的表达水平，应用反转录-聚合酶链反应法检测核转录因子κB mRNA动态变化。结果：15只猪均进入结果分析。①自首次判定脑死亡后12h开始，脑死亡组和N-乙酰半胱氨酸组尿素氮和肌酐水平逐渐升高（P〈0．05），相同时间点比较N-乙酰半胱氨酸组显著低于脑死亡组（P〈0．05）。②自首次判定脑死亡3h开始，脑死亡组及N-乙酰半胱氨酸组白细胞介素1β、白细胞介素6、肿瘤坏死因子α逐渐升高（P〈0．05），相同时间点比较N-乙酰半胱氨酸组显著低于脑死亡组（P〈0．05）。③自脑死亡后3h开始，脑死亡组及N-乙酰半胱氨酸组肾组织NF-κB mRNA其蛋白表达水平逐渐升高（P〈0．05），相同时间点比较N-乙酰半胱氨酸组显著低于脑死亡组（P〈0．05）。④N-乙酰半胱氨酸组和脑死亡组动物脑死亡后12h可见肾脏结构变化，N-乙酰半胱氨酸组变化程度明显轻于脑死亡组。结论：N-乙酰半胱氨酸可能通过抑制核转录因子κB mRNA其蛋白的表达，减少炎症介质的释放，从而保护脑死亡状态下肾脏的功能及结构，提高脑死亡供肾肾移植效果。     

Clinical significance of anti-Yt(b). Report of a case using a 51chromium red cell survival study

Several published reports have documented the variable survival of Yt(a+) red cells (RBC) in patients with anti-Yt(a) as measured by 51Chromium (Cr)-labeled RBC survival studies. Similar studies with anti-Yt(b) have not been reported. A 51Cr-labeled RBC survival study was performed using Yt(b+) RBCs and a monocyte monolayer assay in a young hemodialysis patient who required chronic transfusion therapy and who had developed anti-Yt(b). The survival of the transfused RBCs was 100 and 93 percent at 1 and 24 hours, respectively, with a half life of 21 days at termination of the study (normal, 28 to 32 days). These results showed no evidence of rapid destruction of the Yt(b+) RBCs, indicating that this patient could be transfused safely with blood from Yt(b+) donors. Long-term survival of the 51Cr-labeled Yt(b+) RBCs was shortened moderately, however, a finding that correlated with a slightly abnormal monocyte monolayer assay test.     

Monitoring for undertransfusion

BACKGROUND: Most published reviews and audits of blood and blood component transfusion have focused on the issue of overtransfusion and on the inappropriate use of red cell components. There is growing concern that efforts to curb unnecessary transfusions may result in a trend toward undertransfusion of patients. There is little published information that addresses this issue or the magnitude of this practice. STUDY DESIGN AND METHODS: Undertransfusion was evaluated by examining the transfusion records from a 3-month period for 55 patients who met the study criteria of having either a hemoglobin level < 7 g per dL or a platelet count of < 10 × 10(9) per L. If the identified patient did not receive a transfusion within 24 hours of the reported hemoglobin level or platelet count, the medical record was reviewed by a resident physician. RESULTS: A total of 213 individual hemoglobin levels and platelet counts, representing the 55 patients, met our transfusion criteria. All except 8 of the identified patients received red cells and/or platelet transfusions. Reasons for not transfusing red cells included the patient's response to nutritional support and iron supplementation, refusal of blood, and noncompliance. Reasons for not transfusing platelets included falsely low platelet count because of platelet clumping in vitro, contraindication based on clinical diagnosis (e.g., immune thrombocytopenic purpura), and the patient's death before transfusion. CONCLUSION: Red cell and platelet transfusions were appropriately ordered for all patients who met the transfusion criteria. Undertransfusion is not a problem at this institution according to the criteria established. It is recommended that other institutions expand their blood utilization audits to include investigation for evidence of undertransfusion. Further research regarding the issue of undertransfusion is warranted and could be expanded to include other components.     

Treatment of Felty's syndrome with the haemopoietic growth factor granulocyte colony-stimulating factor (G-CSF)

Felty's syndrome (FS) (rheumatoid arthritis with neutropenia and splenomegaly) has a poor prognosis, largely because of the high risk of severe infection. Granulocyte colony-stimulating factor (G-CSF) is an emerging treatment for chronic neutropenia. We prospectively monitored its use in eight patients with recurrent infections or who required joint surgery. Significant side-effects were documented in five, including nausea, malaise, generalized joint pains, and in one patient, a vasculitic skin rash. In two patients treatment had to be stopped, and in these cases G-CSF had been started at full vial dosage (300 micrograms/ml filgrastim or 263 micrograms/ml lenograstim) alternate days or daily. G-CSF treatment was continued in three patients by restarting at reduced dose, and changing the proprietary formulation. G- CSF raised the neutrophil count, reduced severe infection, and allowed surgery to be performed. A combined clinical and laboratory index suggested that long-term treatment (up to 3.5 years) did not exacerbate the arthritis. Once on established treatment, it may be possible to use smaller weekly doses of G-CSF to maintain the same clinical benefit. One of the three patients whose FS was associated with a large granular T-cell lymphocytosis showed a reduction in this subset of lymphocytes during G-CSF treatment.      

Long-term follow-up testing of red cell alloantibodies

BACKGROUND: In previous studies, 29 to 34 percent of potentially hemolytic red cell antibodies were not detected after short-term follow- up. STUDY DESIGN AND METHODS: To examine long-term detection, records were reviewed for 44 consecutive patients who were tested more than 5 years after their potentially hemolytic red cell antibodies were first identified in this hospital. RESULTS: After 5 to 10 years, 14 (39%) of 36 Rh, Kell, and Duffy system antibodies were not detected on at least one occasion. Twenty-two other such antibodies were sought again after more than 10 years; 10 (45%) were not detected. When restimulation by pregnancy was excluded, these rates were 42 and 48 percent, respectively. CONCLUSION: Clinically significant red cell antibody formation is probably more common than previously realized, because nearly half of these antibodies are undetected after long-term follow- up.     

Severe malaria in children in Papua New Guinea

The clinical features of severe falciparum malaria and risk factors for mortality were studied in 489 children admitted with malaria to Madang Hospital, Papua New Guinea. The most common severe manifestations of malaria were severe anaemia (22%) and coma (16%). Children with severe anaemia were younger than those with coma (median age 2.2 vs. 3.7 years) and had been ill for longer before admission (median 7 vs. 4 days, respectively). Although the clinical features of coma in Madang children with malaria resembled closely those reported in African children, mortality was lower (8% vs. 17-25%, respectively). Overall, 17 (3.5%) children died, most within 12 h of admission. A high level of plasma lactate (> or = 5 mmol/l) was common (20%) and was the major predictor of death in multiple regression analysis. Raised plasma creatinine and decreased plasma bicarbonate were also independent predictors of mortality. Coma was not predictive of death, although a high proportion of children with profound coma died. Investigation of the causes of acidosis in children with malaria is a high research priority. In view of the short time interval between admission and death in many children, emphasis must be placed on the prevention or early recognition and treatment of acidosis in the district health clinic as well as the central hospital.