A case of hemophagocytic syndrome with severe liver injury manifestating adult Still''s disease

We investigated if complement-mediated enhancement of HIV infection occurs in peripheral blood mononuclear cells (PBMC). In 7 experiments, we evaluated the effect of human complement on HIVIIIB infection in vitro. We measured HIV antigen production on day 4 and found that pre-incubation of HIV with complement led to enhanced production of antigen with a median enhancement of 2.5-fold (range 1.1-6.8). This complement-mediated increase in antigen production was statistically significant (p < 0.02). Complement-mediated enhancement of HIV infection was also tested in CD4 cells enriched from PBMC, and CD4 cells persistently gave higher levels of infection enhancement than PBMC. Thus, CD4 cells appear to be sufficient for complement-mediated enhancement of HIV infection to occur. In addition, we tested if it was possible to detect complement-mediated enhancement of primary HIV isolates in PBMC. We tested 3 isolates and found only a minor effect on antigen production (median enhancement 1.2-fold, range 0.6-1.5). Furthermore, addition of HIV-specific antibodies in combination with complement resulted in enhanced antigen production in 2/3 sera tested. However, the combination of complement and antibodies resulted in only a minor increase in enhancement of HIV infection compared to that obtained with complement alone. Finally, we found evidence of complement-mediated enhancement of HIV infection in resting PBMC. In conclusion, we demonstrated that complement-mediated enhancement of HIV infection does occur in vitro in PBMC.     

Assessment of flail mitral leaflets by dynamic three-dimensional echocardiographic imaging

Patients with diabetic amyotrophy may have an inflammatory vasculopathy and may obtain reversal of neurological deficits with immunosuppression. We present a patient with NIDDM, subacute onset of painful asymmetric polyradiculopathy, and unilateral enhancement of lumbar nerve roots on MRI. Clinical improvement and resolution of nerve root enhancement occurred with immunosuppression. We suggest, therefore, that nerve biopsy and gadolinum-enhanced lumbosacral MRI be performed in all patients presenting with diabetic amyotrophy. If nerve root enhancement is present or if nerve biopsy shows perivascular infiltrates, we recommend a trial of immunosuppression.     

Congenital onychodysplasia of the index fingers in identical twins

We describe a patient with metastatic disease to an intracranial meningioma in which MR images showed multiple foci of intense enhancement within a background of moderate enhancement. The discrete foci proved to be metastatic disease from the patient's known breast carcinoma.     

Effect of ethanol on myocardial infarct size in a canine model of coronary artery occlusion-reperfusion

INTRODUCTION: We investigated the effectiveness of Levovist (SHU508A, Schering AG, Berlin, Germany) in the characterization of breast lesions. MATERIAL AND METHODS: June, 1996, to May, 1997, we studied 29 solid lesions in 29 patients (aged 17 to 83 years); our patients were 28 women and 1 man. The 29 solid lesions were 20 carcinomas (15 infiltrating ductal carcinomas, 4 ductal carcinomas in situ, 1 lobular carcinoma in situ), 6 fibroadenomas, 1 suspected postoperative recurrence and 2 apparently benign lesions. We used parameters suitable for the study of slow flows. A single bolus of contrast agent (300 mg/mL) was administered at 1-2 mL/s. Before Levovist injection, we studied the lesion signal intensity and the number of vascular poles. After contrast administration we re-evaluated both these parameters and studied the changes or presence of vessels undetected on the previous images. We also investigated the beginning and duration of enhancement and the presence of vessels inside and outside the lesions. RESULTS: We observed no signal enhancement in 17% of cases, mild enhancement in 7% and strong enhancement in 76% of cases. We found 3 more vascular poles (17%) in 5 lesions and 4 more poles in 3 lesions (10%). Increased vascularization was seen inside the lesion in 17% of cases, inside and outside it in 41% and only outside in 35% of cases. Carcinomas showed a rapid and long-lasting enhancement, while fibroadenomas showed a later and weaker enhancement. CONCLUSIONS: Levovist can be useful in the differential diagnosis of benign from malignant lesions, of recurrences from postoperative fibrosis, as well as in the staging and follow-up of the patients treated with neoadjuvant chemotherapy.     

Abdominal CT findings when the superior vena cava, brachiocephalic vein, or subclavian vein is obstructed

OBJECTIVE: We evaluated findings on contrast-enhanced abdominal CT scans that suggest obstruction of the superior vena cava, brachiocephalic vein, or subclavian vein. SUBJECTS AND METHODS: We conducted a retrospective review of 22 patients with superior vena caval, brachiocephalic vein, or subclavian vein obstruction and analyzed the upper abdominal images on a chest CT scan or an abdominal CT scan. We assessed collateral vessels in the upper abdomen to answer the following question: Did enhancement approach undiluted IV contrast or were there other findings? In the second part of our study, we conducted a prospective review of abdominal CT scans of 200 patients without known mediastinal disease or known upper extremity venous occlusion to determine the frequency of abnormal enhancement of these vessels in a healthy population. RESULTS: The groups of collateral vessels revealed on abdominal CT scans were azygos or hemiazygos veins, internal mammary veins, lateral thoracic and superficial thoracoabdominal veins, vertebral venous plexus veins, and small mediastinal collateral veins. In the retrospective series, one patient had focal enhancement of the liver and early inferior vena caval enhancement due to collateral vessels. In the prospective series, abdominal CT scans of two patients (1%) revealed dense undiluted enhancement of one or more groups of collateral vessels: One patient had an ipsilateral pacemaker, and the other patient had an anterior neck phlegmon to the upper mediastinum. Both conditions may have been factors in the revealing of the collateral vessels. Two other patients (1%) in the prospective series had mild to moderate vessel enhancement that was less than that from undiluted contrast material. In one of these patients, the enhancement was related to abdominal wall hyperemia after surgery. In the other patient, enhancement may have been the result of ipsilateral axillary nodes. CONCLUSION: On upper abdominal CT scans, dense undiluted contrast material in the collateral vessel groups that we studied suggests possible obstruction of the superior vena cava, brachiocephalic vein, or subclavian vein.     

Real time signal processing in the clinical setting

We routinely use a variety of real time signal acquisition, enhancement, and display techniques in the operating room to provide the surgeon with functional information. This enables reduction of surgical morbidity in cases which present a significant risk to the nervous system. Here we present regression based signal processing algorithms which produce considerable signal-to-noise-ratio enhancement with corresponding reduction in the time required to obtain an interpretable neurophysiological signal. We also present the approach we have applied to fault tolerance and distributed data display for our workstation cluster environment.     

Mamillary body enhancement on MR as the only sign of acute Wernicke encephalopathy

We report a case of Wernicke encephalopathy in which the only sign of acute disease was enhancement of the mamillary bodies. This case demonstrates the utility of gadolinium enhancement at MR imaging as a means of diagnosing or confirming the syndrome of Wernicke encephalopathy even in the absence of atrophy or T2 abnormalities within the diencephalon and mesencephalon.     

Brainstem mediates diazepam enhancement of palatability and feeding: microinjections into fourth ventricle versus lateral ventricle

The hypothesis that benzodiazepine-induced hyperphagia is due to a specific enhancement of the palatability of foods has been supported by previous 'taste reactivity' studies of affective (hedonic and aversive) reactions to taste palatability. Diazepam and chlordiazepoxide enhance hedonic reactions of rats (rhythmic tongue protrusions, etc.) to sweet tastes in a receptor-specific fashion. A role for brainstem circuits has been indicated by a previous demonstration of the persistence of the taste reactivity enhancement by diazepam after midbrain decerebration. The present study examined whether benzodiazepine brainstem receptors are the chief substrates for palatability enhancement even in intact brains. We compared the effectiveness of benzodiazepine microinjections to elicit feeding and enhance hedonic reactions when delivered into either the lateral ventricle (forebrain) or the fourth ventricle (brainstem) of rats. The results show diazepam is reliably more effective at eliciting feeding and enhancing positive hedonic reactions to oral sucrose when microinjections are made in the fourth ventricle than in the lateral ventricle. We conclude that brainstem neural systems containing benzodiazepine-GABA receptors are likely to be the chief substrates for benzodiazepine-induced palatability enhancement.     

Gadolinium-enhanced MR imaging of pediatric patients after reduction of dysplastic hips: assessment of femoral head position, factors impeding reduction, and femoral head ischemia

OBJECTIVE: We describe gadolinium-enhanced MR imaging of position and vascular enhancement of the femoral head in pediatric patients who have undergone reduction of hip dislocation. SUBJECTS AND METHODS: Within 24 hr of hip reduction and spica casting, we performed 25 gadolinium-enhanced MR studies in 18 infants and young children (15 girls, three boys) with 23 dysplastic hips. All but two patients underwent closed reductions. We evaluated intraoperative arthrograms for obstacles to reduction and subsequent radiographs for avascular necrosis. RESULTS: MR images showed that all femoral heads were in their respective acetabula, but several structures interfered with concentric reduction. Obstacles to reduction included a pulvinar (n = 16), infolding of the capsule (n = 9), interposition of the labrum (n = 2), and a hypertrophied ligamentum teres and transverse ligament (n = 2). All 50 femoral heads showed enhancement: 35 normally, 10 homogeneously but less than on the contralateral femoral head or the ipsilateral greater trochanter, and five with areas of focally decreased enhancement. Hips that showed decreased enhancement had undergone greater degrees of abduction (r = .38, p < .01). CONCLUSION: Gadolinium-enhanced MR imaging can reveal abnormalities of hip position and proximal femoral epiphyseal and physeal vascularity that can occur after hip reduction. Abnormalities of enhancement were more frequent in patients who had greater femoral abduction. The effect of decreased epiphyseal vascular enhancement is still uncertain.     

Nurses and physicians evaluate their intensive care experiences

PURPOSE: To evaluate quantitative analysis of dynamic breast MRI studies using a dedicated PC based diagnosis system (DS) providing parametric images and automatic ROI definition as compared to the standard subtraction image, manual-ROI based procedure. METHODS: We compared the diagnostic usefulness of parametric versus subtraction images in terms of visualisation of enhancement inhomogeneities and enhancement velocities. Quantitative analysis of enhancing lesions of 15 breast MRI studies was performed using both the DS and the system's console software (SC). We assessed the time needed for complete quantitative analysis and number of lesions evaluated. This was followed by assessment of within-reader and between-reader variability or within-case reproducibility of results of quantitative analysis. RESULTS: Parametric images are superior to subtraction images in visualizing enhancement inhomogeneities or ring enhancement in breast cancers. Mean time needed for analysis at DS and SC was 4 (3-5) min. and 23 (8-39) min., respectively. During this time period, significantly more lesions were evaluated per case using the DS as compared to the SC (2-14 vs. 1-6). Mean within-reader variability of enhancement velocities of the same lesions was 0% and 25% (DS and SC); between-reader variability of enhancement values obtained in the same lesions was 11% (DS) versus 41% (SC). CONCLUSION: The DS significantly cuts down the time needed for quantitative analysis. It significantly improves reproducibility of quantitative enhancement values due to standardization of ROI analysis.     

Tetraethylammonium-induced synaptic plasticity in rat neocortex

Recordings were obtained from neurons in layer II/III of slices of rat frontal cortex maintained in vitro. We investigated whether brief application of the potassium channel blocker tetraethylammonium (TEA), which induces a novel form of synaptic plasticity in the CA1 region of the hippocampus referred to as LTPK, evokes similar responses in neocortex. Consistent with previous findings, TEA produced a persistent enhancement of excitatory transmission, which was independent of NMDA receptor activation but required the activation of nifedipine-sensitive voltage-dependent Ca2+ channels (VDCC), presumably the L-type. We also observed a persistent enhancement of presumptive CI(-)-dependent GABAA receptor-mediated transmission. Enhancement of excitatory and inhibitory synaptic transmission did not require activation of synapses with electrical stimulation during TEA application. The enhancement of excitatory, but not inhibitory synaptic transmission, was blocked when the Ca2+ chelator 1,2-bis(2-aminophenoxy)-ethane N,N,N',N'-tetraacetic acid (BAPTA) was included in the recording electrode. Under voltage clamp conditions that minimized the activation of L-type channels robust enhancement of both excitatory and inhibitory transmission was still observed. No enhancement of excitatory synaptic transmission was observed in the presence of NiCl2, a putative T-type channel blocker. The possible involvement of kinase activation was studied by including the non-specific and competitive kinase inhibitor (+/-)-1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H-7) in the patch pipette. H-7 retarded the time course and reduced the magnitude of the enhancement of excitatory transmission. These results suggest that TEA-induced enhancement of excitatory transmission in the neocortex requires entry of Ca2+ into the postsynaptic neuron via VDCCs and possibly the activation of a kinase.     

Long-term enhancement of entorhinal-dentate evoked potentials following 'modified' ECS in the rat

Electroconvulsive therapy (ECT) is widely used as a treatment for drug-resistant depression. The animal analogue of ECT is electroconvulsive shock (ECS) seizures. We have recently shown that repeated ECS seizures cause a long-lasting, perhaps permanent, enhancement in entorhinal-dentate evoked potentials in the rat. Our study, however, involved 'unmodified' ECS, whereas in clinical practice ECT is now usually given in its 'modified' form (with near-threshold currents, a short-acting barbiturate, muscle relaxant and oxygen). We have therefore repeated our experiments using modified ECS. Entorhinal-dentate evoked potentials were measured in Long-Evans rats before and after: (1) eight modified ECS seizures; or (2) eight sham modified ECS trials. Despite the use of the modified procedure, a significant and long-lasting enhancement in population spike amplitude was seen in the ECS group. We conclude that the modified procedure does not protect rats against the long-lasting enhancement of evoked potentials. Similar changes may be occurring in the brains of patients subjected to modified ECT.     

Tumor imaging with a macromolecular paramagnetic contrast agent: gadopentetate dimeglumine-polylysine

RATIONALE AND OBJECTIVES: We evaluated magnetic resonance (MR) contrast enhancement of tumor tissue following injection of the macromolecular conjugate, gadopentetate dimeglumine-polylysine. METHODS: T1-weighted MR imaging scans were performed on female Fisher-344 rats with subcutaneously implanted mammary adenocarcinoma tumors. Following the baseline scan, gadopentetate dimeglumine-polylysine or gadopentetate dimeglumine was injected at a dose of 0.1 mmol gadolinium per kilogram. RESULTS: Gadopentetate dimeglumine-polylysine injection resulted in a maximum enhancement of tumor contrast of 310 +/- 60% (n = 7). Tumor tissue remained enhanced and well defined for several days after gadopentetate dimeglumine-polylysine injection. Gadopentetate dimeglumine injection at the same dose resulted in a 70 +/- 25% (n = 4) maximal tumor enhancement and a corresponding 25 +/- 4% muscle enhancement. CONCLUSION: Gadopentetate dimeglumine-polylysine provides higher, more sustained tumor contrast than does gadopentetate dimeglumine for the same dosage of gadolinium.     

Endolymphatic sac enhancement surgery in elderly patients with Ménière's disease

Ménière's disease is a pathologic condition of the inner ear that is characterized by vertigo, tinnitus and a progressive loss of hearing. When Ménière's disease is unresponsive to medical treatment and when destructive surgery is not advisable, patients, particularly the elderly, often benefit from endolymphatic sac enhancement, a conservative, nondestructive surgical procedure. We evaluated the outcomes of 62 such patients, aged 65 years and older, who underwent a total of 78 endolymphatic sac enhancements. We assessed their response to surgery by means of a questionnaire, which classified pre- and post-surgical data according to criteria established by the American Academy of Otolaryngology-Head and Neck Surgery. Of the 27 patients who returned questionnaires, 23 reported significant alleviation of vertigo symptoms and 19 said their hearing ability had either improved or was maintained at presurgical levels. Endolymphatic sac enhancement resulted in no mortality, and morbidity was documented in only one patient. We conclude that endolymphatic sac enhancement is a safe and viable treatment for elderly patients with Ménière's disease that is refractory to medical therapy.     

Ventricular tachycardia--diagnosis and therapy

We report a case of radiation-induced optic neuropathy in a 32-year-old man with Cushing's disease and a recurrent tumour of the left cavernous sinus. The patient experienced rapid, painless loss of vision 4 years after treatment without recurrence of tumour or other visual disorder. MRI showed enlargement and contrast enhancement of the optic chiasm. A year later the patient was almost blind and MRI showed atrophy and persistent contrast enhancement of the chiasm.     

Contrast media-enhanced magnetic resonance imaging visualizes myocardial changes in the course of viral myocarditis

BACKGROUND: The course of tissue changes in acute myocarditis in humans is not well understood. Diagnostic tools currently available are unsatisfactory. We tested the hypothesis that inflammation is reflected by signal changes in contrast-enhanced magnetic resonance imaging (MRI). METHODS AND RESULTS: We assessed 44 consecutive patients with symptoms of acute myocarditis. Nineteen patients met the inclusion criteria revealing ECG changes, reduced myocardial function, elevated creatine kinase, positive troponin T, serological evidence for acute viral infection, exclusion of coronary heart disease, and positive antimyosin scintigraphy. We studied these patients on days 2, 7, 14, 28, and 84 after the onset of symptoms. We obtained ECG-triggered, T1-weighted images before and after application of 0.1 mmol/kg gadolinium. We measured the global relative signal enhancement of the left ventricular myocardium related to skeletal muscle and compared it with measurements in 18 volunteers. The global relative enhancement was higher in patients on days 2 (4.8+/-0.3 [mean+/-SE] versus 2.5+/-0.2; P<.0001); 7 (4.7+/-0.5, P<.0001); 14 (4.6+/-0.5, P<.0002); and 28 (3.9+/-0.4, P=.009) but not on day 84 (3.1+/-0.3; P=NS). On day 2, the enhancement was focal, whereas at later time points, the enhancement was diffuse. In patients with evidence of ongoing disease, the values remained elevated. CONCLUSIONS: Acute myocarditis evolves from a focal to a disseminated process during the first 2 weeks after onset of symptoms. Contrast media-enhanced MRI visualizes the localization, activity, and extent of inflammation and may serve as a powerful noninvasive diagnostic tool in acute myocarditis.     

Silver enhancement of gold antibody probes in pre-embedding electron microscopic immunocytochemistry

In pre-embedding EM immunocytochemistry with gold probes, the gold must be small enough to penetrate through cell membranes treated with mild detergents. Antibodies labeled with small gold probes (1-1.4 nm) are too small to be resolved in thin sections but can be seen if they are silver-enhanced after the gold has bound to the antigens in the cells. We investigated several aspects of gum arabic-silver lactate-hydroquinone enhancement solution (Danscher solution) by examining gold-conjugated antibodies embedded in agar, sectioned on a vibrotome, and enhanced with different solutions. The rate of silver enhancement was optimized in 50% gum arabic and 200 mM HEPES buffer, pH 5.8. We also examined chemicals used as developers and found that N-propyl gallate (NPG) gave a more uniform development than the routinely used hydroquinone (HQ). The diameter of the silver-enhanced particles after incubation in osmium tetratoxide (OSO4) decreased somewhat with longer incubation time and higher percentages, but the density (number per unit area) of silver-enhanced particles was little changed. The loss of silver-enhanced particle diameter was reduced by lowering the concentration of OSO4 to 0.1%. Comparison of commercial small gold probes showed that NPG enhancement of Nanogold gave more uniform particle size and a better correlation between enhancement time and particle density. When this procedure was applied to cell cultures with monoclonal antibodies, the silver-enhanced particles were similar to those in the agar sections. When free-floating tissue sections were used, longer silver enhancement times were needed to obtain similarly sized particles. This new NPG-silver-enhancement procedure offers a reliable and easy method to localize proteins in cultured cells and tissue sections by pre-embedding electron microscopic immunocytochemistry.     

Isolated third nerve palsy due to sarcoidosis

We present a 28-year-old man with isolated third nerve palsy as the initial manifestation of sarcoidosis. MRI demonstrated abnormal enhancement of the cisternal portion of the right third nerve. One month after steroid therapy, he showed almost complete recovery with resolution of the contrast enhancement on MRI. This patient illustrates the usefulness of enhanced MRI for detection of cranial nerve lesions of sarcoidosis.     

Interactive 3-dimensional computerized tomography reconstruction in evaluation of the living renal donor

OBJECTIVE: This study investigated the findings revealed by dynamic helical CT of proximal arterioportal shunting associated with hepatocellular carcinoma. We also evaluated the diagnostic capability of this imaging technique to reveal the mass in patients with hepatocellular carcinoma. CONCLUSION: On dynamic helical CT, proximal arterioportal shunting altered liver perfusion and tumor enhancement. Heterogeneous enhancement of liver parenchyma and decreased enhancement of hepatomas diminished diagnostic capability on the arterial dominant phase image. However, with the addition of imaging in the arterial portal phase, lesion conspicuity improved.     

Genetic characterization of an oral treponeme isolated from human subgingival plaque

INTRODUCTION: Since many benign and malignant pathologic conditions can appear as solitary pulmonary nodules, to establish nodule nature is always necessary for correct patient management. Recently, some authors have demonstrated the effectiveness of incremental dynamic CT in distinguishing cancerous from noncancerous lesions. The purpose of this work is to report our personal experience in this field. MATERIAL AND METHODS: We reviewed the incremental dynamic CT scans of 21 patients with a solitary pulmonary nodule < 3.5 cm phi without any calcifications, cavities and fat--namely, 15 carcinomas, 3 granulomas, 2 hamartomas, 1 abscess. Lesion density was evaluated before and 30 s, 1, 2, 3 and 5 min after contrast agent administration; we used a circular region of interest consisting of the central portion of the nodule in all cases and of 60-70% of its area in most cases. We subdivided the nodules into two groups, according to their enhancement: the nodules with > 20 HU and those with < 20 HU. All the lesions were submitted to surgery and histologic studies. RESULTS: Fourteen of 15 carcinomas and one hamartoma had contrast enhancement > 20 HU; an abscess exhibited marked ring-shaped contrast enhancement (positive predictive value: 87%). One carcinoma, three granulomas and one hamartoma had no contrast enhancement, or else it was < 20 HU (negative predictive value: 80%). DISCUSSION: Recently, some authors have demonstrated that malignant nodules, studied with incremental dynamic CT, have higher contrast enhancement than benign nodules. A value > 20 HU is a good predictor of malignancy (positive predictive value: 90%) and, conversely, a value < 20 HU is an unquestionable sign of benignity (negative predictive value: 100%). Our findings confirm the positive predictive value of enhancement > 20 HU, but not its negative predictive value because we found a malignant nodule without contrast enhancement. CONCLUSIONS: Incremental dynamic CT is an effective indicator of solitary pulmonary nodule nature, but its predictive value is not absolute and therefore this technique should be integrated with biopsy in the cases which are clinically or radiologically suspicious.