Suspected appendicitis in children: rectal and intravenous contrast-enhanced versus intravenous contrast-enhanced CT

PURPOSE: To retrospectively compare the diagnostic performance of intravenous contrast material-enhanced computed tomography (CT) with that of intravenous and rectal contrast-enhanced CT in the evaluation of children suspected of having appendicitis by using pathologic findings, surgical findings, or a follow-up telephone call as the reference standard. MATERIALS AND METHODS: This HIPAA-compliant study was approved by the committee on clinical investigations. As part of a larger study, informed consent was obtained from all parents and from all children older than 7 years. Consecutive patients aged 5-21 years who presented to the emergency department and were suspected of having appendicitis were studied with CT. From April 2003 until February 2004, patients underwent intravenous and rectal contrast-enhanced CT. From March 2004 until December 2004, patients underwent intravenous contrast-enhanced CT. Demographic data, clinical outcomes, and test performance characteristics--including sensitivity, specificity, accuracy, and negative and positive predictive values--were compared. RESULTS: Of the 416 patients who met inclusion criteria, 223 underwent intravenous and rectal contrast-enhanced CT and 193 underwent intravenous contrast-enhanced CT. There were no differences in sex distribution (55% vs 52% male patients), frequency of appendicitis (36% vs 32%), or frequency of equivocal CT findings (4%) between the groups. Intravenous and rectal contrast-enhanced CT had a sensitivity of 92% (95% confidence interval [CI]: 85%, 97%), a specificity of 87% (95% CI: 79%, 92%), a negative predictive value of 94% (95% CI: 90%, 98%), and an accuracy of 89% (95% CI: 85%, 93%). Intravenous contrast-enhanced CT had a sensitivity of 93% (95% CI: 84%, 97%), a specificity of 92% (95% CI: 85%, 96%), a negative predictive value of 95% (95% CI: 90%, 99%), and an accuracy of 92% (95% CI: 88%, 96%) (P > .2 for all comparisons). Conclusion: There was no significant difference between the performance of intravenous contrast-enhanced CT and that of rectal and intravenous contrast-enhanced CT in children suspected of having appendicitis.     

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Episodic painless hematuria of unusual etiology--a case report and review of literature

We present the case of an 11-year-old girl with hereditary hemorrhagic telangiectasia who presented with recurrent macroscopic hematuria secondary to bladder vascular abnormalities. This case illustrates the importance of taking a detailed clinical and family history and cystoscopic examination at the time of active hematuria in cases where recurrent hematuria persists and no other cause is identified.     

Carbon Monoxide Rescues Heme Oxygenase-1-Deficient Mice from Arterial Thrombosis in Allogeneic Aortic Transplantation

Heme oxygenase-1 (HO-1) catalyzes the conversion of heme into carbon monoxide (CO), iron, and biliverdin. In preliminary studies, we observed that the absence of HO-1 in aortic allograft recipients resulted in 100% mortality within 4 days due to arterial thrombosis. In contrast, recipients normally expressing HO-1 showed 100% graft patency and survival for more than 56 days. Abdominal aortic transplants were performed using Balb/cJ mice as donors and either HO-1^+/+ or HO-1^−/− (C57BL/6×FVB) mice as recipients. Light and electron microscopy revealed extensive platelet-rich thrombi along the entire length of the graft in HO-1^−/− recipients at 24 hours. Treatment of recipients with CORM-2, a CO-releasing molecule (10 mg/kg of body weight intravenously), 1 hour prior and 1, 3, and 6 days after transplantation, significantly improved survival (62% at >56 days, P < 0.001) compared with HO-1^−/− recipients treated with inactive CORM-2 (median survival 1 day). Histological analyses revealed that CO treatment markedly reduced platelet aggregation within the graft. Adoptive transfer of wild-type platelets to HO-1^−/− recipients also conferred protection and increased survival. Aortic transplants from either HO-1^−/− or HO-1^+/+ C57BL/6 donors into HO-1^+/+ (Balb/cJ) mice did not develop arterial thrombosis, surviving more than 56 days. These studies demonstrate an important role for systemic HO-1/CO for protection against vascular arterial thrombosis in murine aortic allotransplantation.Heme oxygenase-1 (HO-1) is an inducible enzyme that catalyzes the rate-limiting step in heme degradation, leading to the generation of equimolar amounts of iron, biliverdin, and carbon monoxide (CO). Biliverdin is then converted to bilirubin by biliverdin reductase.^1,2 HO-1 is highly up-regulated in mammalian tissues in response to a wide variety of conditions including vascular injury, ischemia, inflammation, immune injury, oxidative stress, cell cycle dysregulation, and sublethal and lethal cell damage.^3,4,5 The wide range of inducers of HO-1 provides support for a vital role in maintenance of cellular homeostasis under different pathophysiological conditions including inflammatory diseases such as septic shock and asthma,^6,7 cardiovascular diseases such as myocardial infarction and atherosclerosis,^8,9 ischemia-reperfusion injury in multiple organ systems,^8,10 and transplant rejection.^11,12One of the products of HO-1-mediated heme degradation, CO, is known to be toxic at high concentrations due to its high affinity for hemoglobin. However, there is substantial evidence that lower concentrations of CO endogenously generated from the breakdown of heme by HO serves essential regulatory roles in a variety of physiological and pathophysiological processes.¹³ Exogenous or endogenous CO can confer some of the cytoprotective effects attributed to HO-1.^14,15Transitional metal carbonyls, CO-releasing molecules (CORMs), have been used to deliver CO in a controlled manner without altering carboxyhemoglobin levels.^16,17,18 A wide range of CORMs containing manganese (CORM-1), ruthenium (CORM-2 and −3), boron (CORM-A1), and iron (CORM-F3) are currently being investigated to facilitate the pharmaceutical use of CO for the prevention of vascular dysfunction, inflammation, ischemia-reperfusion injury, and transplant rejection.^{19,20,21,22,23}Thrombosis is a major complication during multiple vascular pathological conditions during which HO-1 and its byproduct CO could provide significant protection through attenuation of inflammation, endothelial cell damage, and apoptosis, as well as modulation of vascular tone.^6,8,9 However, very little is known regarding the potential roles of HO-1 and CO in modulating platelet-dependent effects after vascular injury in the setting of transplantation. In these studies, we show that expression of HO-1 plays a critical role in the development of post-transplant arterial thrombosis immediately following abdominal aortic transplantation. We tested the hypothesis that CO, a product of the HO-1 reaction, mediates anti-thrombotic effects in vivo by inhibition of platelet mediated thrombus formation within the graft. We found that HO-1-deficient mice develop vascular thrombosis following aortic transplantation and that the development of thrombosis can be prevented by systemic administration of CORM-2.     

Correlation of physical parameters during radiochemical synthesis of (18)F positron emission tomography radiopharmaceuticals

Positron emission tomography is a highly specialized imaging technique using short-lived radiolabel substances to produce extremely high resolution images of the body's biological function. The (18)F(-) ion is produced via the (18)O(p,n)(18)F reaction using a silver target cell filled with 1.4 mL of enriched [(18)O] water. On a typical run, the target is irradiated for 45 minutes with 16.5 MeV protons (on target) and an average beam current of 5-45 mA. When the same reaction takes place with [(16)O] water [(13)N] Ammonia is produced as the primary product by the abstraction of hydrogen from water. This study investigated the physical parameters of medical cyclotron during the radiochemical process with induced radioactivity flux and mutual correlation of physical parameters for 16.5 MeV medical cyclotron at the INMAS Delhi, India. It is observed that by getting farther from the target, the relative number of low-energy neutrons increases while the overall flux of neutrons decreases. This is due to multiple scattering of high-energy neutrons in the walls and eventually absorption of low-energy neutrons. The other parameters are also linked with each other which are correlatable.     

Convergence of entorhinal and CA3 inputs onto pyramidal neurons and interneurons in hippocampal area CA1--an anatomical study in the rat

The entorhinal cortex (EC) conveys information to hippocampal field CA1 either directly by way of projections from principal neurons in layer III, or indirectly by axons from layer II via the dentate gyrus, CA3, and Schaffer collaterals. These two pathways differentially influence activity in CA1, yet conclusive evidence is lacking whether and to what extent they converge onto single CA1 neurons. Presently we studied such convergence. Different neuroanatomical tracers injected into layer III of EC and into CA3, respectively, tagged simultaneously the direct entorhino-hippocampal fibers and the indirect innervation of CA1 neurons by Schaffer collaterals. In slices of fixed brains we intracellularly filled CA1 pyramidal cells and interneurons in stratum lacunosum-moleculare (LM) and stratum radiatum (SR). Sections of these slices were scanned in a confocal laser scanning microscope. 3D-reconstruction was used to determine whether boutons of the labeled input fibers were in contact with the intracellularly filled neurons. We analyzed 12 pyramidal neurons and 21 interneurons. Perforant path innervation to pyramidal neurons in our material was observed to be denser than that from CA3. All pyramidal neurons and 17 of the interneurons received contacts of both perforant pathway and Schaffer input on their dendrites and cell bodies. Four interneurons, which were completely embedded in LM, received only labeled perforant pathway input. Thus, we found convergence of both projection systems on single CA1 pyramidal and interneurons with dendrites that access the layers where perforant pathway fibers and Schaffer collaterals end.     

A rare actinomycosis of humerus: an unusual location and a diagnostic dilemma. A case report

Background Isolated actinomycosis of the humerus is a very rare entity. Method A 30-year-old male had an erythematous plaque with a pus-(minimal) discharging sinus over left lower arm. The patient had no discharge of sulphur granules from the sinus. The patient had raised ESR with a single lytic lesion with minimal sclerosis and inconspicuous periosteal reaction on radiographs. Such atypical clinical and radiological features lead to initial wrong diagnosis of tuberculosis. A diagnosis of Actinomycosis of humerus became possible after demonstration of filamentous bacilli in culture and on histopathology from the sulphur grains obtained by open biopsy. Result The patient recovered completely after administering PenicillinG 24 million units intravenous for 7 days followed by 1.2 g of oral amoxicillin in three divided doses for 3 months and did not show any recurrence during last 2 years of follow up. Conclusion Surgeons should be aware of this rare entity and difficulty in its diagnosis due to its variable manifestations, including confusion with highly endemic tuberculous infection. Awareness of full spectrum of the diseases and careful evaluation in individual cases will expedite diagnosis and avoid unnecessary surgical interventions. No financial or any otherwise support has been received in any regard from any organization or institution for this case report titled “A rare actinomycosis of humerus: an unusual location and a diagnostic dilemma—a case report.” All authors have contributed to the study and publication of this case report and agree in congruence to the same.