Computed tomography and ultrasound findings of a gas-containing splenic abscess.

A patient with an intrasplenic abscess diagnosed by computed tomography (CT) and ultrasound is presented. The characteristic findings of a gas-containing abscess, namely, a low density mass on CT coupled with an echo-free lesion associated with distal acoustical shadowing, are described.     

Cytopathologic and genetic diagnosis of pulmonary amebiasis: a case report

BACKGROUND: Amebiasis is a parasitic infection with Entamoeba histolytica. Pulmonary amebiasis is rare since the infection is commonly manifested as amebic colitis or liver abscess. Most pleuropulmonary amebiasis is seen in patients with amebic liver abscesses. A pulmonary amebic lesion without either a liver abscess or amebic colitis is extremely rare. Thus, reported cases of sputum cytologic diagnosis of a pulmonary amebic lesion from a patient without a liver abscess are also very rare. CASE: A 53-year-old man presented with a dry cough and mild fever. Chest radiography revealed an abnormal solitary mass lesion in the right upper lung field. The clinical diagnosis was a bacterial lung abscess. Sputum cytologic examination demonstrated many trophozoites of E. histolytica. Following sputum cytodiagnosis, serologic tests revealed a slightly high but almost normal titer of IgG antibodies to E. histolytica, indicating the possible presence of the pathogen. Polymerase chain reaction (PCR) using E. histolytica-specific primers for DNA extracted from the sputum sample revealed specific DNA product. CONCLUSION: Pulmonary amebiasis without either a liver abscess or amebic colitis must be distinguished from bacterial abscesses and neoplastic disease. A sputum cytologic examination combined with PCR for DNA extracted from a sputum sample is a good approach to the diagnosis of a pulmonary amebic abscess.     

CT appearance of experimental thalamic radiofrequency lesion in dog

The location and extent of thalamic lesions following thalamotomy can be identified as a large low density area in the acute stage to a small spot in the chronic stage. Stereotactic experimental radiofrequency lesions were placed in the thalamus of 35 mongrel dogs. CT images and whole brain specimens were obtained on days 0, 3, 7, 10, 14, 21 and 60. The appropriate time to map the lesions in the thalamus was thought to be about day 14, because of the thalamic size ratio and the correction of the ventricular deformity. The histological area of the lesion at day 14 corresponded better to the contrast-enhanced area than to that of the plain CT. These results suggest that the lesion demonstrated by contrast-enhanced CT scans at day 14 gives the best anatomical mapping of the actual histological defect.     

Pulmonary nocardiosis associated with cerebral abscess successfully treated by co-trimoxazole: a case report

Nocardiosis is an acute or chronic infectious disease caused by the soil-borne filamentous bacteria belonging to the genus Nocardia. The organisms opportunistically infect both immunocompromised and immunocompetent individuals. The lungs are the primary site of infection and brain abscess is, by far, the most common complication following nocardial metastasis from pulmonary lesions. Although surgical intervention must always be considered in the treatment of nocardial brain abscess, it can obviously be cured by antibiotic therapy alone. This report describes a case infected by Nocardia cyriacigeorgica. Identification of the infectious agent was achieved by conventional and semi-nested PCR techniques. A 55-year-old woman with fever was referred to the infect disclinic of Imam Khomeini hospital in Tehran and was hospitalized after clinical assessment. She was a kidney transplant recipient for 4 years and was taking immunosuppressive treatment including azathioprine and methylprednisolone. Follow-up of the patient by CT scan revealed pulmonary infection and cerebral lesions. Specimens of the brain lesions contained filamentous bacteria. The patient received a combination of co-trimoxazole and ceftriaxone and brain abscesses as well as lung inflammation disappeared gradually during the course of antibiotic therapy within 3 months. The patient was discharged from the hospital after 2 months of therapy.     

Description of diffuse interstitial lung diseases and assessment of their activity

Conventional roentgenograms constitute the groundwork for the evaluation of diffuse interstitial lung disease (DILD). ILO classification with its symbols (additionally extended to granulomatoses) does not comprise pathoanatomic assumptions and does not enter lesion genesis for it could lead to diagnostic misconception. "High resolution" computer tomography (HRCT) provides the evaluation of lesion morphology and disease activity. After having treated our 129 patients with diffuse interstitial lung disease we have come to the conclusion that, beside pneumoconiosis, the application of extended standard ILO symbols are suitable to other interstitial pathology for the homogeneity of morphologic characteristics. As for diagnoses making, in distinction to other methods, it can be said that analyzing roentgenograms of the extended ILO provides high level of lesion evaluation standardization for diffuse interstitial disease as well as substantial congruity with CT finding. It is clear that such analysis cannot be applied in our daily work, however we have both concluded and proved that on conventional roentgenograms the condition of interstitial lesion can roughly be assessed. This is of high importance considering minimal dose of radiation exposure by standard tests in comparison with other radiological techniques. Nevertheless, CT scanning should be performed if there should be the need for the assessment of the morphology and the activity of lesion, to the benefit of our patients.     

Treatment of stage IIIB squamous-cell lung cancer with pembrolizumab combined with chemotherapy to achieve pCR: a case report

Lung cancer is currently the leading cause of global cancer-related deaths and its incidence increases every year. Most squamous-cell lung cancers are in the advanced stage at diagnosis. This study reported a case of a 66-year-old man diagnosed with unresectable stage IIIB squamous-cell lung cancer (cT2aN3M0), who was treated with pembrolizumab combined with paclitaxel (albumin-bound) + nedaplatin. After four cycles, a follow-up chest computed tomography (CT) scan showed the disappearance of the original right lower lobe lung mass with cavitation-like changes, and a follow-up chest CT scan 6w later revealed a solid nodule measuring approximately 1.5 cm in diameter within the cavity. Subsequent surgical excision of the residual primary lesion was performed to achieve complete pathological remission. The patient was treated with pembrolizumab combined with paclitaxel (albumin-bound) + nedaplatin and achieved complete pathological remission with surgical excision.     

Absceso tiroideo. Serie de casos y revisión de la literatura

Thyroid abscess is rare in children but the presence of previous thyroid disease, and congenital remanants such as a pyriform sinus fistula, are predisposing factors. The classical presentation consists of fever, cervical pain and a painful mass. The diagnosis is confirmed through clinical findings, and by diagnostic imaging (ultrasound and computerized axial tomography). A barium swallow must be performed in order to detect a fistula and to consider surgical drain. We present the cases of thyroid abscess in five patients who were admitted in four medical centers (Fundación Cardioinfantil, Hospital Universitario San Ignacio, Clínica infantil de Colsubsidio and Hospital de la Misericordia) in Bogotá, Colombia between 2000 and 2010.     

Bacterial endocarditis of the mitral valve associated with annual calcification.

Bacterial endocarditis, caused mainly by Staphylococcus aureus, was found at autopsy in five patients who had a calcified posterior mitral valve annulus. Clincopathologic correlation indicates that the infection should be suspected in elderly patients with a calcified mitral annulus, the murmur of mitral insufficiency, fever, anemia, polymorphonuclear leukocytosis and a positive blood culture, regardless of evidence of peripheral embolism or of another disease that could cause the last four features. Pertinent pathologic findings are a calcified mitral valve annulus, vegetations of bacterial endocarditis towards the base of the posterior leaflet associated with leaflet perforation and an annulus abscess, and no other valvular disease. The infection may develop on the atrial aspect of a leaflet ulcerated by the calcium mass or may begin on its ventricular aspect, subsequently perforating the leaflet and infecting its atrial surface.     

The role of nigral projections to the thalamus in drug-induced circling behaviour in the rat

Unilateral injection of 6-hydroxydopamine (6-OHDA) into the ascending nigrostriatal pathway caused contraversive circling to apomorphine and ipsiversive circling to amphetamine respectively. An electrolesion of the ventromedial thalamic nucleus on the same side as the 6-OHDA lesion reduced apomorphine-induced circling, but not that to amphetamine. An electrolesion of the ventromedial thalamic nucleus on the side opposite to the 6-OHDA lesion reduced amphetamine circling but not that to apomorphine. Bilateral electrolesions of the ventromedial thalamic nucleus reduced neither apomorphine- nor amphetamine-induced circling. Electrolytic lesions of the parafascicular thalamic nucleus did not reduce apomorphine- or amphetamine-induced circling in animals with a unilateral 6-OHDA lesion of the nigrostriatal pathway. Knife cuts rostral and dorsal to the substantia nigra did not attenuate circling induced by injection of muscimol into the substantia nigra. Circling due to activition of nigral output pathways can be mediated by descending nigro-reticular pathways.     

A thalamo-cortical neural mass model for the simulation of brain rhythms during sleep

Cortico-thalamic interactions are known to play a pivotal role in many brain phenomena, including sleep, attention, memory consolidation and rhythm generation. Hence, simple mathematical models that can simulate the dialogue between the cortex and the thalamus, at a mesoscopic level, have a great cognitive value. In the present work we describe a neural mass model of a cortico-thalamic module, based on neurophysiological mechanisms. The model includes two thalamic populations (a thalamo-cortical relay cell population, TCR, and its related thalamic reticular nucleus, TRN), and a cortical column consisting of four connected populations (pyramidal neurons, excitatory interneurons, inhibitory interneurons with slow and fast kinetics). Moreover, thalamic neurons exhibit two firing modes: bursting and tonic. Finally, cortical synapses among pyramidal neurons incorporate a disfacilitation mechanism following prolonged activity. Simulations show that the model is able to mimic the different patterns of rhythmic activity in cortical and thalamic neurons (beta and alpha waves, spindles, delta waves, K-complexes, slow sleep waves) and their progressive changes from wakefulness to deep sleep, by just acting on modulatory inputs. Moreover, simulations performed by providing short sensory inputs to the TCR show that brain rhythms during sleep preserve the cortex from external perturbations, still allowing a high cortical activity necessary to drive synaptic plasticity and memory consolidation. In perspective, the present model may be used within larger cortico-thalamic networks, to gain a deeper understanding of mechanisms beneath synaptic changes during sleep, to investigate the specific role of brain rhythms, and to explore cortical synchronization achieved via thalamic influences.     

Massive primary hepatic tuberculoma mimicking hepatocellular carcinoma in an immunocompetent host

Tuberculoma of the liver is rare in an immunocompetent individual. We report a 26-year-old man with upper abdominal pain, abnormal liver function, and raised inflammatory markers. Abdominal computed tomography (CT) scan revealed a mixed attenuation lesion measuring 6 x 5 cm occupying most of the left lobe of the liver. Subsequent histology and culture confirmed tuberculous abscess. Following antituberculous therapy, repeat CT scan revealed complete resolution of the initial findings. This case illustrates the diagnostic difficulties of hepatic tuberculosis (TB) and the importance of considering TB in patients with hepatic lesions.     

Diagnosis and treatment of brainstem mass lesions by CT-guided stereotactic surgery

Current neuroradiographic techniques including computed tomographic scanning (CT) and magnetic resonance imaging (MRI) when added to the clinical neurologic examination can localize precisely even small lesions within the brainstem. While the clinical-radiographic diagnosis is accurate with respect to locale, it is often in error with respect to the pathologic nature of the solitary brainstem lesion. Therefore, empiric treatment without the benefit of a tissue diagnosis will often be inappropriate. CT-guided stereotactic surgery can safely and reliably provide a tissue diagnosis in such cases. Furthermore, in selected cases, therapeutic interventions can be of substantial and lasting benefit to the patient.     

Safe and successful endoarterial infusion of liposomal amphotericin B in treatment of mucormycosis

Mucormycosis is a rare invasive mycotic infection treated by antifungini or amphotericin B. We describe the case of a patient with septic fever and a necrotic lesion, with phlegmon of medial left thigh. Surgery was performed to drain the abscess content and to remove the necrotic tissue; mucormycosis was diagnosized by histological and culture tests and treated by intravenous amphotericin B. Since the lesion worsened, liposomal amphotericin B was directly infused into the left common iliac artery, with progressive improvement, and treatment was continued until complete recovery. Therefore, the endoarterial infusion of liposomal amphotericin B was a safe and successful treatment of advanced lesions of mucormycosis. In such lesions, intravenous general antibiotic administration probably is not sufficient to reach the whole infected area.     

The role of computed tomographic and digital radiographic techniques in stereotactic procedures for electrode implantation and mapping, and lesion localization

This paper describes a computer-based system for analyzing stereotactic CT scans and angiograms. Simple Plexiglas frames containing metallic marker pellets and rods are affixed to the sides of the frame during CT scanning and angiography. The images of these markers are recognized by the computer program and used to compute the frame coordinate system. Coordinates of a lesion on CT and angiogram images may be readily computed and coordinate sets specified by the operator may be displayed on the imager, along with positions of implanted electrodes and a numerical indication of recorded activity for each site.     

Primary Renal Hydatid Cyst: Mis-Interpretation as a Renal Malignancy

Primary renal echinococcosis, a rare disease involving the kidney, accounts for 2-3% of human echinococcosis. A 64-year-old female patient from Uzbekistan presented with complaints of left flank pain. A CT scan revealed a cystic mass in the upper to midpole of the left kidney. We regarded this lesion as a renal malignancy and hand-assisted laparoscopic radical nephrectomy was performed to remove the renal mass. The mass consisted of a large unilocular cyst and multiple smaller cysts without any grossly visible renal tissue. The final pathologic diagnosis was a renal hydatid cyst. For patients from endemic areas, hydatid cyst should be included in the differential diagnosis. Here, we present a case of renal hydatid cyst in a female patient who relocated from Uzbekistan to Korea.     

超声引导下穿刺置管引流治疗肝脓肿的疗效分析

目的:探讨超声引导下穿刺置管引流治疗肝脓肿的临床疗效。方法:回顾性分析本院2012-2013年56例肝脓肿住院患者超声引导下穿刺置管引流治疗的临床资料。结果:56例患者行超声引导下穿刺置管引流治疗,其中3例多发脓肿行2次穿刺置管治疗,其余均一次穿刺置管成功,未出现出血、胆漏、周围脏器损伤等并发症,本组患者手术前后体温、白细胞数及脓肿面积比较均有统计学意义(P0.01)。24例体温升高患者中,21例术后3天内恢复正常,3例仍有升高;41例白细胞数升高患者中,29例术后3天内恢复正常,12例仍有增高;56例患者术后脓肿面积均明显减小,该组患者腹痛、肝区叩痛等临床症状均明显缓解。结论:超声引导下穿刺抽吸及置管引流治疗肝脓肿是一种简单方便、安全可靠、创伤小、明显有效的局部治疗方法,操作者需要充分作好术前准备,严格把握适应症,严谨操作步骤并结合全身抗生素治疗可以明显改善患者发热症状,有效降低患者白细胞及中性粒细胞,明显缩短治疗周期,提高治愈率。     

Renal abscess due to Aspergillus fumigatus as the only sign of disseminated aspergillosis in a patient with AIDS

BackgroundAspergillus fumigatus can cause a wide variety of clinical syndromes, especially in the three largest immunocompromised groups, such as HIV-infected patients. Primary renal aspergillosis is an extremely rare entity.AimsWe report an unusual case of renal abscess due to Aspergillus fumigatus in a patient with AIDS.MethodsWe review clinical and laboratory records, and provide follow up of the patient.ResultsA 38-year-old man, HIV seropositive, was admitted to our hospital with fever, lumbar pain and respiratory symptoms. Abdominal ultrasound and computerised tomography showed a single and large lesion consistent with an abscess located in the left kidney. Aspergillus fumigatus was isolated from clinical sample obtained by ultrasound-guided needle aspiration. Despite a correct treatment based on amphotericin B and drainage of the abscess, surgery was necessary and nephrectomy was carried out. Histopathological examination of the surgical specimen confirmed the diagnosis of renal aspergillosis. Systemic antifungal therapy based on intravenous and oral voriconazole and highly active antiretroviral therapy was started after surgery. The patient had a good response to the established treatment and he remains in a good clinical condition at one year of follow up.ConclusionsCombined medical and surgical treatment is the elective therapy for renal abscesses due to Aspergillus when percutaneous drainage and the administration of systemic antifungal drugs, such as amphotericin B and/or oral voriconazole or itraconazole, fail. This case emphasizes renal fungal infections should be included in the differential diagnosis of kidney abscesses in AIDS patients.     

<Emphasis Type="Italic">Paracoccidioides brasiliensis</Emphasis> Infection Mimicking Recurrent Hodgkin Lymphoma: A Case Report and Review of the Literature

Paracoccidioides infection is a rare entity in the USA. This dimorphic fungus is found in Central and South America and is thought to be acquired by inhalation through the soil. We report a case of Paracoccidioides brasiliensis infection presenting as a clavicular bone lesion, peripancreatic mass, and various skin lesions. A 35-year-old man with a history significant for Hodgkin lymphoma presented with a left clavicular mass that was suspected clinically and radiologically as recurrent Hodgkin lymphoma. He was not experiencing any associated symptoms and was undergoing chemotherapy treatment for his known Hodgkin disease. On CT imaging, the mass was seen as a lytic bone lesion with an overlying soft tissue mass. This was biopsied and histologically diagnosed as a Paracoccidioides brasiliensis infection with associated necrotizing granulomatous inflammation. Also found on the CT scan was an enlarging peripancreatic mass which on endoscopic biopsy had similar histologic findings. In conclusion, this report presents a rare case of Paracoccidioides brasiliensis infection mimicking recurrent Hodgkin lymphoma.     

Optogenetic Stimulation of the Corticothalamic Pathway Affects Relay Cells and GABAergic Neurons Differently in the Mouse Visual Thalamus

The dorsal lateral geniculate nucleus (dLGN) serves as the primary conduit of retinal information to visual cortex. In addition to retinal input, dLGN receives a large feedback projection from layer VI of visual cortex. Such input modulates thalamic signal transmission in different ways that range from gain control to synchronizing network activity in a stimulus-specific manner. However, the mechanisms underlying such modulation have been difficult to study, in part because of the complex circuitry and diverse cell types this pathway innervates. To address this and overcome some of the technical limitations inherent in studying the corticothalamic (CT) pathway, we adopted a slice preparation in which we were able to stimulate CT terminal arbors in the visual thalamus of the mouse with blue light by using an adeno-associated virus to express the light-gated ion channel, ChIEF, in layer VI neurons. To examine the postsynaptic responses evoked by repetitive CT stimulation, we recorded from identified relay cells in dLGN, as well as GFP expressing GABAergic neurons in the thalamic reticular nucleus (TRN) and intrinsic interneurons of dLGN. Relay neurons exhibited large glutamatergic responses that continued to increase in amplitude with each successive stimulus pulse. While excitatory responses were apparent at postnatal day 10, the strong facilitation noted in adult was not observed until postnatal day 21. GABAergic neurons in TRN exhibited large initial excitatory responses that quickly plateaued during repetitive stimulation, indicating that the degree of facilitation was much larger for relay cells than for TRN neurons. The responses of intrinsic interneurons were smaller and took the form of a slow depolarization. These differences in the pattern of excitation for different thalamic cell types should help provide a framework for understanding how CT feedback alters the activity of visual thalamic circuitry during sensory processing as well as different behavioral or pathophysiological states.