IgE antibodies to Plasmodium falciparum and severity of malaria in children of one ethnic group living in Burkina Faso

Plasmodium falciparum malaria infection induces elevated blood levels of both total immunoglobulin and anti-plasmodial antibodies belonging to different isotypes. We have previously shown that donors living in areas of malaria transmission develop malaria-specific IgE antibodies that are present at highest concentrations in patients with severe disease, suggesting a role for this isotype in malaria pathogenesis. To establish the possible importance of IgE in the course and severity of this disease, we have analyzed a large and homogenous group of African children (age range = 6 months to 15 years) belonging to one ethnic group (Mossi) living in identical epidemiologic conditions in the same urban area (Ougadougo) of Burkina Faso. While IgG antibodies to P. falciparum increased to high concentrations in very young children and then remained at these levels in older patients, IgE antibodies increased with age, becoming most significantly elevated in children more than four years of age. In older children, those with severe malaria had significantly higher IgE antibody levels than those with non-severe disease. No significant differences between the patient groups were seen for IgG antibodies to P. falciparum. However, when the patients with severe malaria were divided into two groups distinguished by the presence of absence of coma, both IgG and IgE antibodies against malaria were lower in the comatous patients than in the non-comatous patients. The results support the conclusion that IgE antibodies against malaria, regardless of their possible protectivity, also contribute to disease severity in this large and homogenous group of African children.     

Magnetic resonance imaging of the kidney

Summary At present, MRI of the kidney is considered to be a problem-solving imaging modality that is complementary to CT and ultrasound. The anatomy of the kidney and perirenal space is consistently visualized on MRI, which provides excellent demonstration of the corticomedullary differentiation on T1-weighted images. The indistinctness or obliteration of corticomedullary differentiation is a sensitive but nonspecific finding. The large field of view provided by MRI facilitates the diagnosis of congenital anomalies, but the high cost of the examination precludes its use as a primary imaging method. The use of contrast media has expanded the application of MRI into the detection and characterization of renal masses. However, the greatest value of MRI lies in the staging of renal-cell carcinoma, specifically in cases in which CT and ultrasound findings have proved to be inconclusive. The main advantages provided by MRI in such cases involve the assessment of vascular patency and the evaluation of direct tumor extension.     

Evaluation of prostate size: A comparison of ultrasound and magnetic resonance imaging

To determine the relative accuracy of ultrasonography (US) and magnetic resonance imaging (MRI) in the evaluation of prostate volume, we compared US and MR images with surgical findings in 15 patients. Transabdominal US was excellent for determining prostate size in patients with small to moderate enlargement. When compared with surgical specimens, the difference between the weight of the gland as predicted by US and the actual weight was 14% (SD±12). With the transabdominal approach, the length was often inaccurately imaged, but the addition of transrectal scans in the sagittal projection improved results: with combined transabdominal and transrectal US, the average difference in weight was 8% (SD±7). The MRI more accurately predicted prostatic volume (average difference, 6% (SD±6), but the difference between the latter 2 is not significant.     

Second-Opinion Interpretations of Gynecologic Oncologic MRI Examinations by Sub-Specialized Radiologists Influence Patient Care

Purpose

To determine if second-opinion review of gynaecologic oncologic (GynOnc) magnetic resonance imaging (MRI) by sub-specialized radiologists impacts patient care.

Methods

469 second-opinion MRI interpretations rendered by GynOnc radiologists were retrospectively compared to the initial outside reports. Two gynaecologic surgeons, blinded to the reports’ origins, reviewed all cases with discrepancies between initial and second-opinion MRI reports and recorded whether these discrepancies would have led to a change in patient management defined as a change in treatment approach, counselling, or referral. Histopathology or minimum 6-month imaging follow-up were used to establish the diagnosis.

Results

Second-opinion review of GynOnc MRIs would theoretically have affected management in 94/469 (20 %) and 101/469 (21.5 %) patients for surgeons 1 and 2, respectively. Specifically, second-opinion review would have theoretically altered treatment approach in 71/469 (15.1 %) and 60/469 (12.8 %) patients for surgeons 1 and 2, respectively. According to surgeons 1 and 2, these treatment changes would have prevented unnecessary surgery in 35 (7.5 %) and 31 (6.6 %) patients, respectively, and changed surgical procedure type/extent in 19 (4.1 %) and 12 (2.5 %) patients, respectively. Second-opinion interpretations were correct in 103 (83 %) of 124 cases with clinically relevant discrepancies between initial and second-opinion reports.

Conclusions

Expert second-opinion review of GynOnc MRI influences patient care.

Key points

? Outside gynaecologic oncologic MRI examinations are often submitted for a second-opinion review.? One-fifth of MRIs had important discrepancies between initial and second-opinion interpretations.? Second-opinion review of gynaecologic oncologic MRI is a valuable clinical service.

     

Bile duct disease: Prospective comparison of ERCP,CT, and fat suppression MRI

The authors compared computed tomography (CT) and endoscopic retrograde cholangiopancreatography (ERCP), techniques commonly used to study the biliary tree, with pre- and post-Gd-DTPA breath-hold fast low angle shot (FLASH) and fat suppressed spin-echo in 28 consecutive patients with bile duct abnormalities detected on ERCP, including 11 patients with malignant disease and 17 patients with benign disease. ERCP, CT, and magnetic resonance (MR) images were prospectively interpreted in a blinded fashion and reviewed by consensus. ERCP characterized all cases of malignant disease by the presence of a narrowed bile duct lumen with irregular margins. CT and MRI detected all cases of malignant disease and characterized nine of 11 as malignant. In seven of these cases, CT and MRI showed thickening of extrahepatic bile duct walls >5 mm. MRI images showed intrahepatic-enhancing periportal tissue in four cases, which was not seen on CT images, and which was biopsyproven tumor extension. Benign disease was characterized on ERCP images by the demonstration of smooth tapered narrowings in 16 cases, whereas on CT and MR images it was characterized by mild to moderate dilatation of the intrahepatic bile ducts and wall thickness < 5 mm in 13 cases. Overall ERCP correctly characterized 27 cases as benign or malignant and CT and MRI both characterized 25. The results of this study show a trend that ERCP is superior to CT and MRI for characterizing bile duct disease.     

Liver lesion detection: Comparison between excitation-spoiling fat suppression and regular spin-echo at 1.5T

The role of excitation-spoiling fat suppression (fatsat) imaging in the detection of liver lesions was assessed comparing short TR/TE and long TR/ TE spin-echo (SE) sequences with and without excitation-spoiling fat suppression in 25 patients at 1.5T. The study included patients with liver metastases (n = 21), primary liver cancer (n=3), and hepatic adenoma (n=1). Liver lesion detection and lesionliver signal-to-noise ratios (SNR) were determined for the various imaging sequences in a prospective fashion. Liver lesion-liver SNR were highest for long TR/TE (2000-2500/70-80) fatsat images (12.7±4.8) compared to long TR/TE regular SE (2000-2500/70-80) images (8.8±5.6) [(p = ns) (not significant)], short TR/TE (200-400/15-20) fatsat images (-6.2±4.8) (p=0.05), and short TR/TE regular SE images (-4.9±3.2) (p<0.01). Lesion detection was greatest for long TR/TE fatsat (86) followed by long TR/TE regular SE (78) (p=0.05), short TR/TE fatsat (65) (p<0.01), and short TR/TE regular SE (60) (p<0.01). The results of this study suggest that excitation-spoiling fat suppression may improve liver lesion detection and conspicuity.     

Lysosomal enzyme studies after endotoxin administration in normothermia and hypothermia

The LD₅₀ dose of endotoxin results in a considerable increase in the plasma level of acidic phosphatase and -glucuronidase. The endotoxin decreases the quantity of -globulin fraction of sera as an effect of neutral lysosomal proteases. In hypothermic rabbits the activity of lysosomal enzymes is increased only slightly after administration of endotoxin and the change in the -globulin level is also more less than in the normothermic animals. The importance of our results in the pathogenesis of inflammation induced by endotoxin is discussed.     

Role of preoperative MR imaging in the evaluation of patients with persistent or recurrent gynaecological malignancies before pelvic exenteration

Purpose

To determine the diagnostic performance of MRI in assessing local tumour extent and evaluate associations between MRI features and survival in patients undergoing MRI before pelvic exenteration for persistent or recurrent gynaecological cancers.

Methods and materials

The study included 50 patients with persistent or recurrent gynaecological malignancies who underwent pelvic exenteration between January 1999 and December 2011 and had MRI at most 90 days before surgery. Two radiologists independently assessed invasion of adjacent organs (on a 5-point scale). Diagnostic accuracy, inter-reader agreement, and associations between organ invasion on MRI and patient survival were evaluated.

Results

Areas under receiver operating characteristic curves (AUCs) for invasion of the bladder, rectum and pelvic sidewall were 0.96, 0.90 and 0.98 for reader 1 and 0.95, 0.88 and 0.90 for reader 2. Corresponding sensitivities/specificities were 87.0 %/92.6 %, 81.3 %/97.0 % and 87.5 %/97.2 % for reader 1, and 87.0 %/100.0 %, 75.0 %/97.0 % and 75.0 %/94.4 % for reader 2. Inter-reader agreement was excellent for organ invasion (κ?=?0.81–0.85). Pelvic sidewall invasion on MRI was associated with overall and recurrence-free survival (P?=?0.01–0.04 for the two readers).

Conclusion

Preoperative MRI is accurate in predicting organ invasion. It may guide surgical planning and serve as a predictive biomarker in patients undergoing pelvic exenteration for gynaecological malignancies.

Key Points

? MRI can accurately assess bladder and rectal wall invasion before major surgery. ? MRI identifies patients requiring extended pelvic exenteration by detecting sidewall invasion. ? Inter-reader agreement for detecting organ invasion and tumor size is excellent. ? Pelvic sidewall invasion on MRI is associated with shorter overall and recurrence-free survival.