De Garengeot's hernia: an unusual right groin mass due to acute appendicitis in an incarcerated femoral hernia.

The presence of an acutely inflamed vermiform appendix in a femoral hernia sac is extremely rare; the condition is termed De Garengeot's hernia. Here we describe an elderly patient for whom preoperative computed tomography aided the diagnosis of this rare entity. This Chinese woman had presented with a painful right groin mass. The patient successfully underwent an emergency appendicectomy and primary femoral hernia repair. Once diagnosed, it is imperative to follow key surgical principles to limit the spread of infection.

Cardiopulmonary manifestations of portovenous shunts from congenital absence of the portal vein: pulmonary hypertension and pulmonary vascular dilatation.

HPS and PPHTN are unusual and challenging pulmonary manifestations of liver disease. We report two pediatric cases in association with heterotaxy polysplenia syndrome and congenital absence of the portal vein. Both patients were symptomatic and hemodynamically compromised and required aggressive medical therapy. One patient with PPHTN alone achieved a successful liver transplant. The second child presented with combined HPS and PPHTN and exhibited a different evolution of pulmonary vascular disease. These cases illustrate associations that must be entertained in the setting of heterotaxy syndrome, cyanosis, or pulmonary hypertension and how strategic medical combined with surgical management can provide a good outcome.

Use of magnetic resonance imaging in evaluation of placental invasion.

AIM: To review and describe the magnetic resonance imaging (MRI) features in patients with suspected placental invasion and correlate the findings with surgery and pathology findings. MATERIALS AND METHODS: A retrospective review was undertaken of the MRI images of seven consecutive patients with ultrasound findings suspicious for placental invasion. Two experienced MRI radiologists, blinded to the pathology and surgery findings, reviewed the MRI. The pathology or surgical findings were used as the reference standard to establish accuracy and concordance with the MRI findings. RESULTS: Three MRI features described in an earlier series were consistently present in the patients with placental invasion: lower uterine bulging, heterogeneous placenta, and dark intraplacental linear bands on T2-weighted images. CONCLUSION: MRI features, which were described in patients with placental invasion in an earlier series, were useful in establishing the presence and depth of placental invasion.

Adenoid cystic carcinoma of the breast.

Adenoid cystic carcinoma of the breast is a rare neoplasm that constitutes less than one percent of all mammary carcinomas. To date, there have been about 140 cases reported in the literature. It is a rare variant of adenocarcinoma that usually occurs in the salivary glands. In contrast to the aggressive nature of adenoid cystic carcinoma that occurs in the head and neck region, adenoid cystic carcinoma of the breast has a very favourable prognosis. Little has been published to date on its radiological features. We describe a 63-year-old woman with adenoid cystic carcinoma detected on mammography in our national breast screening programme, the radiological findings at presentation, the surgical management and a review of the literature.

Prevalence of significant extracoronary findings on multislice CT coronary angiography examinations and coronary artery calcium scoring examinations.

The purpose of the study was to review the prevalence of significant extracoronary findings in patients who underwent multislice CT coronary angiography examinations and coronary artery calcium scoring examinations. We reviewed the reports of 295 consecutive patients who underwent multislice CT coronary angiography examinations and 140 consecutive patients who had separate coronary calcium scoring examinations from September 2004 to March 2006 in our department's radiology information system. Additional investigations carried out as a result of these findings were also recorded. Fifty-six (19%) out of 295 patients had significant extracoronary findings on coronary CT angiography requiring clinical or radiological follow up. There were 60 significant extracoronary findings. These included 24 patients who had pulmonary abnormalities, 4 who had mediastinal abnormalities, 20 who had upper abdominal abnormalities and 5 who had non-coronary cardiac abnormalities. Three patients had both pulmonary and upper abdominal abnormalities. Eleven (8%) out of 140 patients had significant pulmonary, breast, mediastinal, upper abdominal and cardiac abnormalities on coronary artery calcium scoring examinations, yielding a total of 12 significant findings. In our experience, 19% of the patients who underwent multislice CT coronary angiography and 8% of the patients who underwent coronary artery calcium scoring examinations had significant extracoronary findings requiring follow up. It is therefore imperative for the reporting physician to review the entire examination after the coronary arteries have been assessed. The prevalence of extracoronary findings on these examinations may be of significance, resulting in additional 'hidden costs' if widespread 'screening' is adopted.

Gadolinium-enhanced magnetic resonance angiography in renal artery stenosis: comparison with digital subtraction angiography.

OBJECTIVES: To evaluate the accuracy of gadolinium-enhanced magnetic resonance angiography in assessing renal artery stenosis compared to catheter digital subtraction angiography. DESIGN: Retrospective study. SETTING: Singapore General Hospital. PATIENTS: Records of patients who underwent magnetic resonance angiography as well as digital subtraction angiography for assessment of renal artery stenosis from January 2003 to December 2005 were reviewed. RESULTS: There were 27 patients (14 male, 13 female) with a mean age of 62 (range, 44-77) years. There were 10 patients with renal transplants; their native renal arteries were not evaluated. Each of the two experienced interventional and body magnetic resonance radiologists, who were blinded to the results, reviewed the digital subtraction angiography and magnetic resonance angiography images respectively. Digital subtraction angiography was used as the standard of reference. A total of 39 renal arteries from these 27 patients were evaluated. One of the arteries was previously stented and could not be assessed with magnetic resonance angiography due to severe artefacts. Of the remaining 38 renal arteries, two were graded as normal, seven as having mild stenosis (<50%), eight as having moderate stenosis (> or =50% but <75%), and 21 as having severe stenosis (> or =75%). Magnetic resonance angiography and digital subtraction angiography were concordant in 89% of the arteries; magnetic resonance angiography overestimated the degree of stenosis in 8% and underestimated it in 3% of them. In the evaluation of clinically significant renal artery stenosis (> or =50%) with magnetic resonance angiography, the overall sensitivity, specificity, positive predictive value, and negative predictive value were 97%, 67%, 90%, and 86% respectively. The sensitivity and specificity of magnetic resonance angiography in transplant renal artery stenosis was 100%. CONCLUSION. Our experience suggested that gadolinium-enhanced magnetic resonance angiography is a sensitive non-invasive modality useful in the assessment of clinically significant renal artery stenosis.

Posttransplant diabetes mellitus in pediatric thoracic organ recipients receiving tacrolimus-based immunosuppression.

BACKGROUND: Posttransplantation diabetes mellitus (PTDM) is a well-known complication of tacrolimus-based immunosuppression in both adult and pediatric solid organ recipients. The "natural history" of diabetes in the pediatric thoracic transplant population has not yet been described. METHODS: We identified all pediatric thoracic transplant patients receiving tacrolimus-based immunosuppression who developed PTDM. Medical records were reviewed, with a particular focus on the clinical course of PTDM and its relationship to drug weaning. RESULTS: Diabetes developed in 24 of 143 (17%) 30-day survivors of heart (12/96, 13%) and heart-lung/lung (12/ 47, 26%) transplantation. In 17 (71%) patients, the immunosuppressive regimen at the onset of PTDM also included maintenance corticosteroids. Seventeen patients demonstrated glucose intolerance before the onset of diabetes. Nine patients (38%) developed diabetes during pulsed corticosteroid therapy. Median time of onset after transplantation was 9.0 months. All patients required s.c. insulin for glucose control. The median follow-up from transplant was 49.9 months. There was a significant decrease in mean tacrolimus dosage (P<0.01), tacrolimus level (P<0.04), and steroid dosage (P<0.02) from onset of PTDM to most recent follow-up. Despite this significant reduction in immunosuppression, only 3/24 (13%) patients were successfully weaned off insulin. CONCLUSIONS: Diabetes mellitus is a common complication in pediatric thoracic transplant patients receiving tacrolimus-based immunosuppression. Insulin dependence in our population rarely resolved, even after lowering tacrolimus and steroid doses. Discontinuation of steroids did not guarantee resolution of diabetes.

Endomyocardial biopsy in pediatric heart transplant recipients: a useful exercise? (Analysis of 1,169 biopsies).

The objective of this study was to define the diagnostic yield for endomyocardial biopsy (EMB) procedures performed for various indications in a large pediatric heart transplant population. Endomyocardial biopsy procedure has been employed as the 'gold standard' for rejection surveillance. Previous studies have questioned the value of surveillance EMB beyond the early post-transplant period. We retrospectively reviewed data on 82 pediatric heart transplant recipients with serial EMB. A total of 1,169 EMB were performed during a follow-up period of 2-149 months (median 41 months). EMB were classified by age at transplantation, time from transplant, immunosuppressive regimen used [tacrolimus vs. cyclosporin A (CsA)] and indication, i.e. surveillance, follow-up after rejection or lowering of immunosuppression, non-specific clinical symptoms and graft dysfunction. During the first year after heart transplantation, surveillance EMB demonstrated significant rejection [International Society for Heart and Lung Transplantation (ISHLT) grade > or = 3A] in 18% of biopsies with the yield being 14-43% for all other indications. Surveillance EMB 1-5 yr post-transplantation were found to have a lower diagnostic yield in infants (4%, vs. 13% in children) and in patients with favorable first-year rejection history (9% vs. 17% in 'frequent rejectors'). Tacrolimus-based immunosuppression was associated with significantly less rejection, but only in the first year post-transplantation (14% in tacrolimus vs. 24% in CsA surveillance EMB, p = 0.035). Surveillance EMB remains an important diagnostic tool for rejection surveillance during the first 5 years after pediatric heart transplantation. Endomyocardial biopsy is particularly warranted after reduction of immunosuppression and for monitoring for ongoing rejection after treatment of acute rejection episodes.

Optimal dosing of intravenous tacrolimus following pediatric heart transplantation.

BACKGROUND: Early experience with intravenous tacrolimus at high doses (0.1-0.15 mg/kg/day) was associated with frequent clinical toxicity. The optimal dosing regimen after pediatric heart transplantation is unknown. METHODS: We retrospectively reviewed data on the last 45 pediatric heart transplant recipients to document the time required to achieve therapeutic blood levels and the safety of 2 differing intravenous dosing regimens (tacrolimus 0.03 & 0.05 mg/kg/day as continuous i.v. infusion). Target plasma levels were (1.2-1.7 ng/ml) with levels >2.0 ng/ ml considered toxic, and target whole blood levels were 15-20 ng/ml with levels >25 ng/ml considered toxic. RESULTS: Mean age at transplantation was 7.5 +/- 5.6 years (0.1-18), and 14 were infants. Intravenous tacrolimus was commenced at a mean of 7 +/- 3 hours (range 2-16) after arrival in the ICU. Eight patients were excluded from analysis because of protocol modifications. Of the remaining 37 pts, 9 received initial infusion at 0.03 mg/kg/day; 3 (33%) achieved 'therapeutic' levels within 48 hours and 1 patient had a toxic level (27 ng/ml) at 36 hours. Twenty-eight patients received 0.05 mg/kg/day; 18 (64%) achieved therapeutic levels within 48 hours and 9 (32%) developed toxic levels. Patients with toxic whole blood levels had higher tacrolimus levels on first blood assay compared to those who did not develop toxicity (16.4 +/- 3.4 vs 9.3 +/- 3.9, p < .0001; level >10 ng/ml on first assay in 7/7 toxic patients vs 7/19 without toxicity, p = .004). Patients receiving the higher dose regimen had fewer episodes of moderate or severe rejection (> or =Grade 3A) at first biopsy than those receiving the lower dose infusion (32% vs 75%; p = .046). No patient required renal dialysis. CONCLUSIONS: Dosing below 0.05 mg/kg/day may result in clinically important delay in achieving therapeutic levels. Toxicity may be reduced by frequent monitoring of levels for the first 48 hours after transplantation especially when the initial level is >10 ng/ml.

Human CD4 restores normal T cell development and function in mice deficient in murine CD4.

The ability of a human coreceptor to function in mice was investigated by generating human CD4 (hCD4)-expressing transgenic mice on a mouse CD4-deficient (mCD4-/-) background. From developing thymocyte to matured T lymphocyte functions, hCD4 was shown to be physiologically active. By examining the expansion and deletion of specific V beta T cell families in mutated mice with and without hCD4, it was found that hCD4 can participate in positive and negative selection. Mature hCD4 single positive cells also were found in the periphery and they were shown to restore MHC class II-restricted alloreactive and antigen-specific T cell responses that were deficient in the mCD4 (-/-) mice. In addition, these hCD4 reconstituted mice can generate a secondary immunoglobulin G humoral response matching that of mCD4 wild-type mice. The fact that human CD4 is functional in mice and can be studied in the absence of murine CD4 should facilitate studies of human CD4 activity in general and human immunodeficiency virus 1 gp120-mediated pathogenesis in acquired immune deficiency syndrome specifically.