Non-super-selective venous sampling for persistent hyperparathyroidism using a systemic hypocalcemic challenge.

PURPOSE: To describe a new protocol employing an acute systemic hypocalcemic challenge (SHC) aimed at augmenting the parathyroid hormone (PTH) gradient to enable non-super-selective venous sampling (VS) in patients with persistent primary hyperparathyroidism (PHPT). MATERIALS AND METHODS: In a retrospective study, 37 patients (39 studies-20 SHC, 19 super-selective VS) who underwent VS for persistent or recurrent PHPT were examined. Study patients were pretreated with intravenous hydration, diuretics, and bicarbonate to induce temporary relative hypocalcemia and then underwent non-super-selective VS targeted at large vessels within the neck and chest with rapid PTH testing. The traditional VS protocol involved super-selective VS with arteriography. RESULTS: SHC decreased ionized calcium by 0.098 mmol/L ± 0.18 (P = .07) and increased peripheral PTH by 10.2 pg/mL (P = .58). Positive VS gradients, defined as a ≥ 1.4-fold difference from baseline to after SHC, were detected in 95% of patients. VS findings guided successful surgery in 77% of SHC cases and 90% of super-selective VS cases; the peak gradient site was concordant with operative findings in 46% of SHC cases and 80% of super-selective VS cases. Avoidance of super-selective sampling decreased mean fluoroscopy time from 91 minutes to 33 minutes and decreased contrast material administered from 204 mL to 63 mL (both P < .0001). CONCLUSIONS: The SHC protocol to enable non-super-selective VS in patients with persistent PHPT had the same ability as super-selective VS to detect a positive (≥ 1.4-fold) PTH gradient, was associated with decreased accuracy in identifying the site of the adenoma compared with super-selective VS, and significantly decreased contrast material used and fluoroscopy time.

MDCT evaluation of blunt abdominal trauma: clinical significance of free intraperitoneal fluid in males with absence of identifiable injury.

OBJECTIVE: The purpose of our study was to determine the clinical significance of the isolated finding of free intraperitoneal fluid on 64-MDCT in male patients who have undergone blunt trauma. MATERIALS AND METHODS: A retrospective study was performed of 669 consecutive male patients, ranging in age from 15 to 85 years, who underwent CT evaluation of the abdomen and pelvis at our level 1 trauma center over a 17-month period. Two radiologists evaluated the images for the presence of free intraperitoneal fluid and for an underlying cause. For patients with free intraperitoneal fluid, the mean attenuation and the size of the largest pocket of fluid on both portal venous and delayed phase images were measured for both those with and those without injury. For the patients who had free intraperitoneal fluid as an isolated finding, the electronic chart was reviewed to determine the clinical outcome, specifically whether these patients were observed, had short-interval follow-up imaging, or underwent exploratory laparotomy. RESULTS: Forty-eight of the 669 patients (7.2%) had free intraperitoneal fluid. Twenty-nine (4.3%) of these patients had an identifiable solid organ, bowel, bladder, or pelvic injury to explain the free fluid. In the remaining 19 (2.8%) patients, free fluid was an isolated finding. The size of the largest collection of fluid was smaller for patients without identifiable injury on portal venous phase (1,236 vs 348 mm(2)) and delayed phase (1,325 vs 298 mm(2)) images (p = 0.0015 and p < 0.0001, respectively). Fluid in patients without identifiable injury was also shown to be less dense. A statistically significant difference between the mean attenuation coefficients of the fluid in the patients with and without injury was also found on both the portal venous phase (45.1 vs 13.1 HU, p < 0.0001) and delayed phase (45.6 vs 20.8 HU, p < 0.0001) images. All 19 patients without identifiable injury were admitted for observation and discharged without surgical intervention. CONCLUSION: With 64 MDCT, the isolated finding of free intraperitoneal fluid in male patients who have undergone blunt trauma is seen in approximately 3% of patients. The size and mean attenuation coefficient measurements may add useful information regarding the clinical management of these patients, suggesting that small amounts of low-attenuation free fluid, in the absence of identifiable injury, may have no significant clinical implications.

Chronic wound fluid suppresses proliferation of dermal fibroblasts through a Ras-mediated signaling pathway.

Wound fluid collected from chronic venous leg ulcers (chronic wound fluid (CWF)) has been shown to inhibit the growth of dermal fibroblasts by interfering with cell-cycle progression from G1 into S phase. Specifically, CWF was shown to downregulate the levels of hyperphosphorylated retinoblastoma tumor-suppressor gene (Rb) and cyclin D1, known to be critical for entering the S phase of the cell cycle. To further elucidate the effects of CWF, a Ras-mediated signaling pathway involving the mitogen-activated protein kinase kinase (MEK), known to modulate the expression of these cell-cycle-regulatory proteins, was examined. Transient transfection of dermal fibroblasts with constitutively active Ras abrogated the growth suppressive effects of CWF on hyperphosphorylated Rb (ppRb) and cyclin D1. In contrast, an MEK inhibitor PD 98059 mimicked the effects of CWF on these cell-cycle-regulatory proteins. Concurrent treatment with PD 98059 and CWF produced additive effects. Taken together, these results suggest that CWF inhibits the growth of dermal fibroblasts at least in part by decreasing the level of active Ras, resulting in decreased levels of ppRb and cyclin D1. Therefore, a Ras-dependent signaling pathway may mediate the growth inhibitory effect of CWF, and reconstitution of Ras activity may overcome this growth inhibitory effect.