Use of infliximab in pediatric patients with inflammatory bowel disease

BACKGROUND: The concentration of tumor necrosis factor, a proinflammatory cytokine, is increased in the gastrointestinal mucosa of patents with active Crohn's disease (CD) and ulcerative colitis (UC). Neutralization of tumor necrosis factor decreases the mucosal inflammatory response of adults with CD. Little information is available on the use of monoclonal antibody to tumor necrosis factor (infliximab) in children and adolescents with CD or UC. OBJECTIVE: To evaluate the clinical response and side effects of patients to infliximab. METHODS: A retrospective review of data regarding 18 pediatric and adolescent patients with active CD (n = 15) and UC (n = 3) poorly controlled with conventional therapy. All patients received one to six intravenous infusions of infliximab 5 mg/kg, while receiving their usual medications. RESULTS: All patients experienced clinical improvement, including decrease in the frequency of stooling and resolution of extraintestinal symptoms such as arthropathy, malaise, and skin manifestations after treatment with infliximab. All but one patient had a documented decrease in the erythrocyte sedimentation rate. Prednisone dosage was tapered in all but two patients, and discontinued in seven patients. Intravenous infusion of infliximab was well tolerated. One patient developed a rash several days after the infusion. A patient who received six infliximab infusions developed recurrent Staphylococcus aureus infections, as well as septic arthritis and chronic osteomyelitis during the follow-up period, raising the issue of the long-term safety of infliximab. CONCLUSIONS: Treatment of our patients with refractory CD and UC with infliximab was associated with remarkable clinical improvement. Although the drug may have an important role in their management, further assessment of long-term safety and efficacy is needed.     

Interobserver variation in the interpretation of abdominal radiographs

A total of 140 sets of abdominal radiographs were reviewed independently by four qualified diagnostic radiologists. The degree of interobserver agreement was determined by calculating kappa values for 19 commonly used radiographic signs and diagnoses. There was fair to excellent interobserver agreement for 11 signs and diagnoses and poor agreement for the remaining eight. The signs and diagnoses for which agreement is poor cannot be considered reliable and include particularly large bowel obstruction and nonspecific gas pattern.     

Effect of intersection spacing on MR image contrast and study time

The effects of section separation on image contrast and calculated T1 relaxation times were investigated in healthy volunteers and a phantom using an early commercial version magnetic resonance imaging system. The effects are explained qualitatively on the basis of side lobes of excitation occurring outside the selected section resulting in reduction of the time permitted for T1 relaxation. The options for dealing with imperfect section selection, including separation of the sections (i.e., leaving gaps) and nonsequential excitation, are illustrated and the trade-offs involved in each explained.     

The role of prostaglandin E2 in immune suppression following injury.

It has been thought for some time that prostaglandin E2 (PGE2) released from activated monocytes/macrophages may contribute to the suppression of immunity seen after burns and major injury because PGE2 inhibits the activation of T lymphocytes. To clarify this issue, we studied 15 patients with total body surface area burns of 20% to 90% (mean, 48%). Peripheral blood mononuclear cells (PBMC) were obtained from these patients one to two times each week for 1 month after burn and were stimulated with the T-cell mitogen phytohemagglutinin (PHA). On 14 occasions the PBMCs from eight patients were significantly suppressed (30% or more) in their response to PHA (suppressed [sup] burn) as compared with PBMCs from normal controls. In 38 instances PBMCs from 12 patients were not significantly suppressed in PHA (nonsuppressed [nonsup] burn). Sup burn PBMCs and control PBMCs were cultured with or without the addition of the cyclooxygenase (CO) inhibitor indomethacin (Indo, 1 microgram/mL) and studied for PHA response and the production of the stimulatory cytokine interleukin-2 (IL-2). Indo partially restored the PHA response of sup burn PBMCs to normal. Sup burn PBMCs also were deficient in production of IL-2. Indo increased IL-2 production by sup burn PBMCs significantly more (160% +/- 20%, p less than 0.005) than control (57% +/- 5%) and nonsup PBMCs (67% +/- 8%). Next inhibition of the PHA response of PBMCs from 12 burn patients and 17 controls was studied by exogenous PGE2. At all time periods after burn injury, patients' PBMCs were significantly more sensitive to inhibition by PGE2 (50% inhibition at 10(-8) mol/L [molar] PGE2) than PBMCs from normal controls (50% inhibition at 10(-6) mol/L PGE2) with maximum sensitivity occurring 8 to 14 days after injury. Peripheral blood mononuclear cells from patients with more than 40% burns were significantly (p less than 0.05) more sensitive to PGE2 than those from patients with lesser burns. Interleukin-2 was added to cultures of sup burn PBMC, nonsup burn PBMC, and controls containing 10(-7) mol/L PGE2. Interleukin-2 totally reversed PGE2 inhibition of the PHA response in PBMC from both controls and burn patients. Because endotoxin leak from the gut has been implicated as a trigger for a number of the metabolic and immunologic abnormalities following injury, the authors looked for the effect of a bolus infusion of Escherichia coli endotoxin (Endo, 4 ng/kg) in seven normal healthy volunteers on the response of PBMC to PHA and on the production of PGE2 and IL-2.(ABSTRACT TRUNCATED AT 400 WORDS)     

Pulsatile masses surrounding vascular prostheses: real-time US color flow imaging

A prospective evaluation of color flow mapping and real-time ultrasound was performed to determine if pseudoaneurysms could be distinguished from other causes of masses surrounding vascular grafts of the lower extremities. Twelve palpable pulsatile masses were imaged. Diagnoses were confirmed at angiography (n = 11), computed tomography (n = 7), aspiration biopsy (n = 5), and operative intervention (n = 6). A swirling pattern of blood flow was seen in six of seven cases of pseudoaneurysm. Lack of flow signals was noted in four of the five collections representing hematoma (n = 2) or infection (n = 2). The seventh case was later shown to be an infected, thrombosed pseudoaneurysm. The single false-positive diagnosis was made early in the series when the flow signals detected were due to transmitted arterial pulsations. The authors conclude that color Doppler flow imaging is useful in the differential diagnosis of pulsatile masses associated with prosthetic grafts. Prosthetic graft pseudoaneurysms have a specific appearance of swirling blood flow arising from a wide neck and are distinguishable from traumatic or iatrogenic pseudoaneurysms of the native vascular tree.     

Suppression of interleukin 2 production in an animal model of thermal injury is related to prostaglandin synthesis

We performed studies using an animal model of thermal injury to confirm the observed decrease in interleukin 2 (IL-2) production in burned patients and to explore the underlying mechanisms. Ten mice subjected to a 25% scald were compared with ten anesthetized littermates (controls) and six untreated mice (normal mice) 1, 3, 5, 7, 10, 14, and 21 days after burn. Production of IL-2 by splenocytes was stimulated by concanavalin A alone, or in the presence of the cyclooxygenase inhibitor indomethacin or flurbiprofen. The IL-2 content of the resulting supernatant was determined by the response of the IL-2-dependent cell line CTLL-2. The IL-2 production was significantly suppressed in the burned mice at three days (mean +/- SEM, 30.9% +/- 5.2%), five days (19% +/- 5.5%), seven days (41.6% +/- 6.4%), and 21 days (20% +/- 4.5%). Significant enhancement of IL-2 production by indomethacin was seen in the burned group (mean, 95%), but not in controls (mean, 23.8%) or normal mice (mean, 17.2%), and similar effects were seen with flurbiprofen. In separate experiments the effects of exogenous prostaglandin E2 on lymphocyte blastogenesis and IL-2 production were studied, and an increased susceptibility to the inhibitory effects of prostaglandin E2 was observed following thermal injury.     

Perforation of the inferior vena cava with aortic and vertebral penetration by a suprarenal Greenfield filter

Various complications have been reported after insertion of the Greenfield filter. This report describes an unusual complication after suprarenal placement of this filter: spreading of the filter struts, with perforation of the inferior vena cava, and penetration of the aorta and a vertebral body, followed by fracture of one of the struts.     

High-resolution MR imaging with local coils

We propose the following rules to govern the choice of local coils by the practicing radiologist: 1. Smaller coils permit smaller FOVs and better resolution. The coil should be as small as possible. 2. Match the ROS of the coil to the FOV, which will be determined by the anatomic region of interest. 3. For the case of a choice between surface coils or between a surface and a whole- or partial-volume coil, the anatomic region should lie on the high side of the crossover point. For the case of a choice among whole-volume coils, the smallest coil that surrounds the region of interest should be chosen. 4. Considerations in regard to the anatomic shape or the need to vary the position of the structure may alter the choice of coil from that obtained by S/N considerations alone.