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Biomedical subjects

A Ciardi

Publications and source records attributed to A Ciardi.

At least 19 recordsLinked to original sources
PubMed2006

Dynamics of cylindrically converging precursor plasma flow in wire-array Z -pinch experiments.

This paper summarizes the present understanding of the processes leading to precursor column formation in cylindrical wire arrays on the 1 MA MAGPIE generator at Imperial College London. Direct experimental measurements of the diameter variation during the collapse and formation phase of the precursor column are presented, along with soft x-ray emission, and quantitative radiography. In addition, data from twisted cylindrical arrays are presented which give additional information on the behavior of coronal plasma generated in wire array z pinches. Three stages in precursor column formation are identifiable from the data: broad initial density profile, rapid contraction to small diameter, and slow expansion after formation. The correlation of emission to column diameter variation indicates the contraction phase is a nonlinear collapse resulting from the increasing on-axis density and radiative cooling rate. The variation in the minimum diameter is measured for several array materials, and data show good agreement with a pressure balance model. Comparison of column expansion rates to analytical models allows an estimate of column temperature variation, and estimates of the current in the column are also made. Formation data are in good agreement with both fluid and kinetic modeling, but highlight the need to include collisionless flow in the early time behavior.

Journal Article↗
PubMed2006

Non-linearities and data analysis: towards a quantitative investigation of delayed luminescence.

Innovative techniques for the acquisition and analysis of delayed luminescence (DL) signals are proposed and discussed. At a preliminary level, the signals prove to be a useful tool, not only for quantitative analysis, but also for discrimination--on theoretical grounds--among different, possibly competing, mechanisms responsible for DL in photosynthetic organisms. Moreover, DL recordings from non-photosynthetic organisms (S. cerevisiae yeast) with avalanche photodiode (APD) detection will be discussed.

Data Interpretation, Statistical↗
PubMed2006

Pheochromocytoma associated with adrenocortical tumor in the same gland. Two case reports and literature review.

Pheochromocytomas are catecholamine-producing neuroendocrine tumours arising from chromaffin cells of the adrenal medulla or extra-adrenal paraganglionic system that show 2 distinctive features, rarity and clinical variability. Pheochromocytoma occasionally is associated with pathological lesions of the adrenal cortex. We present 2 cases of patients referred to our hospital with a finding of clinical suspected pheochromocytoma. Both of them were hypertensive; the first patient with typical symptoms of pheochromocytoma and the second patient with chest pain and hypertension resistant to pharmacological treatment. The diagnosis of pheochromocytoma was confirmed in both cases with laboratory analysis and the lesion was achieved by employing 3 imaging techniques: computed tomography (CT), magnetic resonance imaging (MRI) and scintigraphy with (123)I-metaiodobenzilguanidine (MIBG). The patients underwent adrenalectomy and in the same adrenal gland we found a pheochromocytoma associated with a nonfunctioning cortical adenoma. As far as we know few cases with this association are available in the literature.

3-Iodobenzylguanidine↗
PubMed2005

Synchronous colon and gastric advanced carcinomas.

An unusual case of advanced synchronous colon and gastric carcinoma is described. A 36 year old female was admitted to our Department with a stenosing right colon cancer diagnosed at endoscopy which was performed for lower crampy abdominal pain and gross blood in the stool. Multiple colon polyps, distal to the tumor, were also detected. On preoperative abdominal computed tomography, a stenosing right colon cancer, without evidence of abdominal diffusion, was confirmed. At laparotomy, in addition to colon cancer, an antral gastric cancer was incidentally found. En bloc hemigastrectomy and subtotal colectomy were performed. Digestive continuity was restored by gastrojejunal and ileosigmoid anastomoses. At histology, a poorly differentiated gastric adenocarcinoma with signet ring-cell component (pT2, pN0; stage IB) and a moderately differentiated colon adenocarcinoma with a tubulovillous component (pT3, pN1; stage III, Stage Dukes C) were revealed. Both tumors showed a low expression of p53 and c-erb2 oncoproteins. No genetic defect was identified in the APC and MMR genes. The patient is alive, without recurrence, two years after the operation.

Adult↗
PubMed2003

Subcutaneous metastasis of pancreatic cancer in the site of percutaneous biliary drainage.

A subcutaneous metastatic lesion from a carcinoma of the pancreas or common bile-duct along the tract of a percutaneous transhepatic biliary drainage is a rare finding. Prompted by a case that came to our observation by chance, we reviewed the literature and analysed the 29 cases collected. Neoplastic cell seeding along a percutaneous drainage tract, albeit rare, must be kept in mind. The complication can be avoided if patients at risk, whenever possible, undergo endoscopic drainage.

Aged↗
PubMed2002

Indirect-drive inertial confinement fusion using highly supersonic, radiatively cooled, plasma slugs.

We present a new approach to indirect-drive inertial confinement fusion which makes use of highly supersonic, radiatively cooled, slugs of plasma to energize a hohlraum. 2D resistive magnetohydrodynamic simulations of slug formation in shaped liner Z-pinch implosions are presented along with 2D-radiation-hydrodynamic simulations of the slug impacting a converter foil and 3D-view-factor simulations of a double-ended hohlraum. Results for the Z facility at Sandia National Laboratory indicate that two synchronous slugs of 250 kJ kinetic energy could be produced, resulting in a capsule surface temperature of approximately 225 eV.

Journal Article↗
PubMed2001

Presacral myelolipoma in a patient with colon carcinoma.

Myelolipoma is an uncommon benign tumor, composed of an admixture of adipose tissue and hematopoietic cells, usually discovered within the adrenal glands. Extra-adrenal myelolipomas are rare and approximately half of the reported cases were presacral. We report a case of an asymptomatic presacral myelolipoma measuring 9x8x7 cm, incidentally found in a 71-year-old woman with a stenosing colon cancer. Ultrasonography, computed tomography and magnetic resonance imaging of the presacral mass evidenced a well circumscribed tumor with heterogeneous features due to a nonuniform composition. Surgical excision of the mass was performed.

Adenocarcinoma↗
PubMed2000

An unusual late radiotherapy-related complication requiring surgery in anal canal carcinoma.

We herein describe an unusual late radiation-related complication requiring surgery in a 60-year-old male affected by anal epidermoid carcinoma. The patient presented with obstructed defecation and ulcerated perianal lesions. The perianal biopsies were positive for anal squamous carcinoma. Transanal diagnostic investigations could not be performed because of anal stenosis. Computed tomography detected left inguinal lymphadenopathy and a nonhomogeneous presacral mass, infiltrating the rectal wall, the coccyx, and the sacrum. The patient underwent a colostomy, infusion of cisplatin and 5-fluorouracil, and irradiation of the pelvis, perianal region, and inguinal lymph nodes. In June 1997 the patient complained of the onset of continuous pain at the genitalia, and for penis necrosis he underwent penis amputation. The histologic examination was conclusive for postradiotherapy thrombosis. This complication could strengthen the hypothesis of vasculoconnective damage as the origin of long-term effects of radiotherapy. Probably the minimal dose in transit volume could not be achieved. Careful evaluation in choosing the treatment scheme is necessary if different options are available.

Amputation, Surgical↗
PubMed2000

Orbital osteoclastoma of apparent extraskeletal origin in a pagetic patient: a case report.

A large mass in the right orbit, causing proptosis, ptosis of the right upper eyelid, and limitation to eye movements, was surgically removed from a 51-year-old woman suffering from Paget's bone disease (PBD). Histologically, a giant cell tumor of the bone (osteoclastoma) was diagnosed. No bony involvement was apparent either operatively, microscopically, or on preoperative computed tomographic scans. The neoplasm has not recurred in a 3-year follow-up. In addition to the fact that osteoclastoma complicating PBD is rare, the extraskeletal origin of the tumor is a matter of interest and can be tentatively explained by an unusually powerful systemic stimulus acting on circulating osteoclast precursors. HUM PATHOL 31:1527-1531.

Female↗
PubMed2000

Postmortem histological survey of the ocular lesions in a British population of AIDS patients.

AIMS: To study ocular pathology and systemic correlations in a series of 73 postmortem eyes from British patients who died from AIDS before the introduction of a HAART regimen. METHODS: The eyes were studied with conventional histology, special histochemical stainings, and immunohistochemistry. RESULTS: 72.6% of the cases showed chronic uveal inflammation, caused by opportunistic agents in 37.7% of them (cytomegalovirus (CMV) in 30.1%, C neoformans in 5.6%, and Gram positive bacteria in 1.8%). Cytoid bodies were noted in 10/73 eyes, three linked to CMV retinitis. Six retinal haemorrhages, four of which were secondary to CMV, were found. 14 specimens (19. 1%) showed foci of calcification, and a further 11 (15%) calcium oxalate deposits. In no cases were the calcific deposits suspected clinically. Six eyes (8.2%) did not show any abnormality. CONCLUSIONS: CMV retinitis is the most common (28.7%, 21/73) ocular infection in this series and may occur either during or in the absence of systemic dissemination. Conversely, ocular cryptococcosis appears to be an epiphenomenon of systemic and CNS disease. No other opportunistic ocular infections were present in this series. Interesting findings were the presence of intraocular precipitates of calcium oxalate and calcium phosphate or carbonate in a significant number of cases (15% and 19%, respectively), and the high prevalence of idiopathic uveal inflammation (43.8%).

AIDS-Related Opportunistic Infections↗
PubMed1999

Histological findings in the eyelids of AIDS patients.

PURPOSE: The eyelids of 15 AIDS patients (17 specimens) were examined histologically at postmortem. METHODS: Formalin-fixed, paraffin-embedded and haematoxylin-eosin stained sections were examined by conventional light microscopy. The presence of calcific deposits was confirmed by special stains and elemental analysis (X-ray energy dispersive spectroscopy). RESULTS: 6 cases had abnormal microscopical findings. In two cases deposits of calcium oxalates were observed in the wall of dermal blood vessels and in epithelial cells of sweat and sebaceous glands, respectively. Precipitates of calcium phosphate were observed in the superficial substantia propria of the palpebral conjunctiva in an additional patient. Other histological findings in the remaining three patients included flat warts, an unusual elastotic degeneration of the forniceal palpebral conjunctiva and more common lesions (chalazion, Demodex folliculorum infestation of the eyelashes, trichilemmal cyst). CONCLUSION: The presence of microscopical lesions in nearly half of this small series demonstrates that the eyelids may be affected subclinically in AIDS patients.

Acquired Immunodeficiency Syndrome↗
PubMed1999

Ocular, cerebral and systemic interrelationships of cytomegalovirus infection in a post-mortem study of AIDS patients.

PURPOSE: Eighty-six post-mortems of AIDS patients were reviewed microscopically and the presence of cytomegalovirus (CMV) infection in the viscera, brain and eye was recorded. METHODS: Immunohistochemical stains and in situ hybridisation with a CMV probe were performed. RESULTS AND CONCLUSION: CMV infection was observed in 63% of the cases. Visceral, cerebral and ocular involvement were overall 49%, 33% and 29%, respectively. The visceral form with no concomitant ocular and/or cerebral infection was the main cause of death (31%) in the 54 CMV-infected patients. Although CMV retinitis occurred mostly (20%) as a component of systemic disease, in 13% of the CMV-infected patients the eyes only were involved, while there were no cases with CMV limited to the brain. In the absence of systemic involvement, 9% of the cases showed concomitant ocular and cerebral infection, but because we failed to observe CMV optic neuritis without ocular involvement, retrograde viral spread from the brain through the optic nerve appears to be an infrequent mechanism of CMV retinitis.

AIDS-Related Opportunistic Infections↗
PubMed1999

Primary non-Hodgkin's lymphoma of the liver.

The clinicopathological features of a rare case of primary non-Hodgkin's hepatic lymphoma (PHL) are described and compared to those of the other 76 cases reported in the world literature. PHL is mainly a disease of Caucasian, middle-aged males and, in approximately half of the reported cases, was associated with other diseases involving depression or chronic stimulation of the immune system. Right upper abdominal and epigastric pain with loss of weight are the most common presenting symptoms. The tumour is usually a single large mass involving both hepatic lobes and is almost invariably composed of lymphocytes reacting with B-cell markers. Most tumours are of intermediate or high grade according to the classification of the Working Formulation for Clinical Usage. No correlation is apparent between gross appearance of PHL (massive or nodular) and grade of severity. Chemotherapy or radiotherapy alone appears to be ineffective, while relatively good results can be obtained with combination modalities.

Adult↗
PubMed1997

Plasma cholesterol regulates soluble cell adhesion molecule expression in familial hypercholesterolemia.

BACKGROUND: Hypercholesterolemia is associated with endothelial dysfunction. On the basis of the hypothesis that high plasma cholesterol per se may be a sufficient stimulus to upregulate endothelial adhesiveness and that this phenomenon might be reversible, soluble endothelial leukocyte adhesion molecules (sELAMs) were studied in patients with familial hypercholesterolemia undergoing LDL apheresis. METHODS AND RESULTS: Selective LDL absorption by dextran sulfate columns was used to treat plasma volumes of 6.5 to 9.2 L; after LDL apheresis, total cholesterol, LDL cholesterol, apolipoprotein B, triglycerides, and lipoprotein(a) levels were reduced by 74%, 82%, 79%, 56%, and 86%, respectively. Soluble intercellular adhesion molecule-1 (sICAM-1) and sELAM- were measured before, immediately after, and 2 and 6 days after LDL apheresis. Basal sICAM-1 and sELAM-1 values were higher than in healthy control subjects. After LDL apheresis, they decreased (P<.0001 and P<.0004, respectively); their removal by extracorporeal circulation components was excluded. Individual pretreatment and posttreatment values of sICAM-1 and sELAM-1 were positively correlated (P<.0001 and P<.001, respectively) with total cholesterol; their rebound curves showed patterns similar to the total cholesterol rebound curve but not to the triglyceride and lipoprotein(a) curves. CONCLUSIONS: In the absence of changes in clinical chemical parameters, tumor necrosis factor-alpha, interleukin-6, and acute-phase reactant proteins, these results confirm in a clinical setting the upregulation of endothelial adhesiveness observed in experimental hypercholesterolemia and suggest a direct role for cholesterol in regulating this phenomenon, at least in familial hypercholesterolemia.

Adult↗
PubMed1996

Sciatic nerve injury in the adult rat: comparison of effects on oligosaccharide, CGRP and GAP43 immunoreactivity in primary afferents following two types of trauma.

Using immunocytochemical and morphometric techniques, the localisation of three neuronal oligosaccharide antigens (two lactoseries and one globoseries oligosaccharide) were studied in the spinal cord and dorsal root ganglia of adult rats following unilateral crushing or transection of the sciatic nerve. The expression of CGRP and GAP43 was also studied for comparison. We found that following transection of the nerve the expression of lactoseries oligosaccharides and CGRP was permanently depressed, whilst that of the globoseries antigen (SSEA4) was unaffected. However following crush trauma and subsequent regeneration after 2 months, only the expression of one lactoseries antigen, LA4 remained significantly depressed. Our results suggest that different subsets of sensory neurons vary in the rate of reaction to injury and that one subset of neurons expressing a lactoseries oligosaccharide antigen is particularly susceptible to axotomy-induced changes. Furthermore neurons expressing the globoseries oligosaccharide antigen SSEA4 appear to be relatively unaffected by peripheral axotomy.

Afferent Pathways↗
PubMed1996

Investigation on the expression of major histocompatibility complex class II and cytokines and detection of HIV-1 DNA within brains of asymptomatic and symptomatic HIV-1-positive patients.

Among the various mechanisms proposed to explain the pathogenesis of cerebral lesions in human immunodeficiency virus (HIV)-induced encephalitis, a cytokine-mediated action has found most favour. Indeed, elevated expression of cytokines such as interleukin (IL)-1 and tumor necrosis factor-alpha (TNF-alpha), thought to be neurotoxic, has been found in AIDS patients. As a previous study had demonstrated the presence of HIV proviral DNA in brain tissue of a number of HIV-positive non-AIDS patients, we undertook this present investigation using morphological, immunohistochemistry (IHC) and polymerase chain reaction (PCR) methods to detect the expression of major histocompatibility complex (MHC) class II molecules, the presence of HIV-1 proviral DNA and of the cytokines TNF-alpha, IL-1 alpha, IL-4 and IL-6 in brains of the same group of individuals. The study included brains of 36 asymptomatic HIV-1 positive patients and the results were compared with those of AIDS patients either affected by HIV encephalitis (n = 8) or exempt from any neuropathological changes (n = 10) as well as of normal controls (n = 5). Results show that: HIV proviral DNA could be detected by PCR in 17 out of the 36 brains from HIV-positive pre-AIDS cases; most (15 of 17) of PCR-positive brains showed minimal to severe expression of MHC class II antigen; and cytokines could be detected predominantly within white matter even at this early stage. The data demonstrated that the state of immune activation described in AIDS is already present at the pre-AIDS stage and suggest that the presence of cytokines may already trigger the cascade of events leading to brain damage.

AIDS Dementia Complex↗
PubMed1996

Acquired immunodeficiency syndrome and ocular calcification.

We report the presence of peculiar nonbanded calcification of the cornea in three patients with acquired immunodeficiency syndrome, discovered on postmortem histological examination of the globes. In one patient, multiple calcium salt precipitates also affected other ocular and orbital structures. Calcium deposits were present in the corneal stroma but spared Bowman's layer, as is usually seen in primary and secondary corneal calcification. The calcified areas were positive to von Kossa, alizarin red, alcian blue, and colloidal iron stains. Electron probe analysis of the three cases showed the presence of calcium and phosphorus in a ratio characteristic for hydroxyapatite. No predisposing factors could be found. The possible role of associated alterations in the mucopolysaccharide content or composition in the calcified areas is unclear.

Acquired Immunodeficiency Syndrome↗