Embryonic phenotype, ß-carotene and retinoid metabolism upon maternal supplementation of ß-carotene in a mouse model of severe vitamin A deficiency.

We investigated the effect of ß-carotene (bC) supplementation during pregnancy in a mouse model of severe vitamin A deficiency, i.e. Lrat-/-Rbp-/- dams maintained on a vitamin A-deficient diet during gestation. bC, a provitamin A carotenoid, can be enzymatically cleaved to form vitamin A for use by the developing embryo. We found that an acute supplementation (13.5 days post coitum, dpc) of bC to Lrat-/-Rbp-/- dams on a vitamin A-deficient diet activated transcriptional mechanisms in the developing tissues to maximize the utilization of bC provided to the dams. Nevertheless, these regulatory mechanisms are inefficient under this regimen, as the embryonic phenotype was not improved. We further investigated the effect of a repeated supplementation of bC during a crucial developmental period (6.5-9.5 dpc) on the above-mentioned mouse model. This treatment improved the embryonic abnormalities, as 40% of the embryos showed a normal phenotype. In addition, analysis of retinoic acid-responsive genes, such as Cyp26a1 in these embryos suggests that bC cleavage results in the production of retinoic acid which then can be used by the embryo. Taken together, these in vivo studies show that bC can be used as a source of vitamin A for severely vitamin A-deficient mammalian embryos.

A noninvasive test of sphincter of Oddi dysfunction in postcholecystectomy patients: the scintigraphic score.

The ideal noninvasive test of sphincter of Oddi dysfunction (SOD) does not exist and the diagnosis of patients with postcholecystectomy pain often relies on invasive procedures. In this paper we describe a scintigraphic test for SOD: the scintigraphic score. This score combines quantitative and visual criteria for interpretation of hepatobiliary scans. Twenty-six consecutive postcholecystectomy patients underwent hepatobiliary imaging, ERCP, and sphincter manometry. Twelve patients had SOD and 14 had normal sphincters determined by clinical findings, ERCP, and manometric studies. All patients with normal sphincter had scores of 0-4, while patients with SOD had values of 5-12 for a perfect sensitivity and specificity of 100%. Hepatobiliary scans scored in this fashion may become the noninvasive test of choice to screen postcholecystectomy patients with suspected SOD.

UTI: diagnosis and evaluation in symptomatic pediatric patients.

We retrospectively reviewed data on 260 hospitalized pediatric patients with symptomatic urinary tract infection (UTI). To ascertain the colony-forming units (CFU)/mL compatible with the diagnosis of UTI, a culture from a catheterized urine specimen containing >1,000 CFU/mL was considered diagnostic of UTI and resulted in imaging by renal ultrasound, voiding cystourethrography, and renal nuclear scan with Tc99m dimercaptosuccinic acid (DMSA). A positive DMSA renal scan is indicative of pyelonephritis. We used logistic regression analysis to determine which patient characteristics were predictive of pyelonephritis. We determined that, in hospitalized pediatric patients, the colony count of the positive urine culture, the type of organism grown in culture, and the voiding cystourethrography (VCUG) result (positive or negative for vesicoureteral reflux) did not predict which patients had pyelonephritis. In females, advancing age of the patient and positive renal ultrasound results were predictive of which patients had pyelonephritis when we controlled for other factors. We feel this emphasizes the importance of a thorough evaluation of hospitalized symptomatic patients, including patients with colony counts of 1,000 to 50,000 CFU/mL, to locate the level of infection and plan appropriate therapy.

Detection of tricuspid regurgitation by Tc-99m DTPA renal scintigraphy.

Tc-99m DTPA renal scintigraphy is an established technique for evaluating renal perfusion and function. A patient is described with clinically unsuspected tricuspid regurgitation detected during the perfusion phase of renal scintigraphy and confirmed by Doppler echocardiography. A review of extrarenal anomalies detected during renal blood flow imaging is presented.

Implementation of an acute myocardial perfusion imaging program for patients with chest pain and nondiagnostic electrocardiogram: the St. Agnes experience.

One of the current focuses of the chest pain emergency department (CPED) movement is to improve community awareness of chest pain signs and symptoms and thereby encourage patients to be evaluated early. However, such a strategy may overwhelm the mechanisms currently in place to evaluate these patients in a timely and cost-effective manner. In this article, the author reviews the experience of St. Agnes HealthCare using acute myocardial perfusion imaging (MPI) to help stratify patients who present with chest pain and nondiagnostic or normal ECG into low- and high-risk groups for the development of acute cardiac events. Currently, St. Agnes is participating in a randomized, multicenter trial to assess clinical and cost efficacy of employing a strategy of acute MPI in the CPED.

Use of gamma detecting probe and isosulphan blue to localize sentinel node in patients with malignant melanoma.

Elective lymph node dissection for patients with malignant melanoma remains controversial. Sentinel lymph node sampling has been recommended to select patients who will benefit from lymphadenectomy. Vital blue dye and a gamma detecting probe have been used to identify the sentinel node. Two patients are described in whom microscopic disease was identified in the sentinel node as the sole focus of metastasis. The ability to excise the sentinel node provides accurate pathologic and staging information, is cost effective, and minimizes the morbidity associated with a routinely performed lymphadenectomy.

Sentinel lymph node mapping for staging breast cancer: preliminary results of a prospective study.

Axillary lymph node dissection is the gold standard for staging breast cancer, but it is associated with significant morbidity and complications. Sentinel lymph node mapping technique has demonstrated a successful detection of the node or nodes more likely to have metastasis. Two techniques are being used to detect sentinel lymph node-intraoperative use of gamma detecting probe after injection of radio tracer preoperatively and the injection of blue dye and lymphatic mapping intraoperatively. We used both techniques. Twenty-four patients underwent sentinel lymph node mapping. Blue dye and gamma detecting probe identified sentinel lymph nodes in 78% and 77% of patients, respectively. Overall, 23 of 24 patients had a sentinel lymph node identified (96%). Ten patients had metastatic disease in the axilla. Out of these ten patients the only positive node/nodes were the sentinel lymph node in six patients. The other four patients had positive non-sentinel lymph node along with positive sentinel lymph node. All of the patients who had metastatic disease in the axilla were detected by the sentinel lymph node mapping technique. Therefore, no patient had positive non-sentinel lymph node if the sentinel lymph node was negative. This technique was 100% predictive of the axillary status. Sentinel lymph node mapping technique will change the management of breast cancer and will allow two-thirds of the patients with breast cancer to be managed without axillary lymph node dissection with a resulting reduction in morbidity and cost.

Minimally invasive parathyroidectomy utilizing a gamma detecting probe intraoperatively.

The most common pathologic finding in primary hyperparathyroidism is a single adenoma. Traditionally, all four glands have been explored during surgery for primary hyperparathyroidism. With the advent of accurate localizing diagnostic studies, such as the sestamibi scan, some surgeons are now recommending single-gland exploration. In addition, when a sestamibi scan is performed the day of surgery, a gamma detecting probe can be used intraoperatively to direct the dissection. Although an experienced surgeon will successfully locate the abnormal gland 95% of the time with the traditional approach, this new technique results in a smaller incision with better cosmetic results as well as decreased operative time. Our initial experience with eight cases utilizing this technique is presented.