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Biomedical subjects

A Dimitriadis

Publications and source records attributed to A Dimitriadis.

At least 19 recordsLinked to original sources
PubMed2007

[Angiographic evaluation and embolization of juvenile nasopharyngeal angiofibroma].

OBJECTIVE: In juvenile nasopharyngeal angiofibroma (JNA), analysis of tumor extension and blood supply is useful for controlling intraoperative bleeding and helps in determining the appropriate surgical approach. The purpose of this study was to evaluate angiographic findings and the efficacy and benefits of preoperative embolization of JNA. PATIENTS AND METHODS: Twenty-one male patients with JNA (mean age 13.3 years) were included in this study. The tumors were embolized with particles of gel foam. Surgical removal was achieved through transantral approach (n=2), lateral rhinotomy (n=13), midfacial degloving (n=4), and endonasally (n=2). RESULTS: The blood supply was exclusively homolateral in 18 patients, deriving mainly from the external carotid artery, and bilateral in three. There were no connections between the branches of the internal and external carotid arteries. Intratumoral embolization was achieved in all patients. No major complications occurred. Mean blood loss during surgery was 560 ml. The recurrence rate was 14%. CONCLUSION: Preoperative angiographic evaluation and embolization of JNA are important tools for planning surgical approach. Embolization reduces significantly the intraoperative blood loss, minimizes the need of blood transfusion, and makes resection easier.

Adolescent↗
PubMed2005

Evaluation of a commercial enzyme immunoassay for detection of norovirus in outbreak specimens.

The aim of the study presented here was to use faeces from 41 gastroenteritis outbreaks (130 specimens) in Victoria, Australia, to evaluate the sensitivity and specificity of the RIDASCREEN norovirus enzyme immunoassay (EIA) kit relative to reverse transcription-polymerase chain reaction and/or electron microscopy. Seven specimens known to contain sapovirus, adenovirus, astrovirus and rotavirus were also tested. For single-specimen diagnosis the kit gave a specificity and sensitivity of 47% and 71%, respectively; altering the positivity cut-off to give a specificity of 73% reduced the sensitivity to 44%. Thus, the kit cannot be recommended for single-specimen diagnosis. One specimen containing adenovirus but not norovirus was identified as non-specifically positive by the EIA kit. If the criterion used for outbreak positivity was at least one EIA-positive specimen per outbreak, the kit's outbreak sensitivity was 94% but the outbreak specificity was only 60%.

Caliciviridae Infections↗
PubMed2004

Perforated diverticulum of the caecum. A difficult preoperative diagnosis. Report of 2 cases and review of the literature.

BACKGROUND: Perforation of a solitary caecal diverticulum is a rare cause of acute abdomen and an uncommon differential diagnosis for acute appendicitis. Nine hundred cases have been described since Potiers' first description of perforated caecal diverticulum in 1912. METHODS: We describe 2 cases of perforated diverticulum of the caecum. The first patient was a 50-year-old man diagnosed by subsequent histology, and the second a 77-year-old woman diagnosed intra-operatively. Radiography, ultrasound and CT scan of the abdomen pointed at the diagnosis in the second case. A right hemicolectomy was performed. RESULTS: There were no complications, apart from a transient faecal fistula in the first patient managed conservatively. In both patients histology revealed a perforated caecal diverticulum. CONCLUSIONS: The surgeon must be familiar with the diagnosis and management of this rare, inflammatory benign caecal entity.

Aged↗
PubMed2004

A case of mucinous adenocarcinoma arising in long-standing multiple perianal and presacral fistulas.

Chronic anal fistulas are not rare; however, the development of a carcinoma in long-standing, perianal fistulas is rare. We describe a case of an 85-year-old man with multiple, recurring, perianal fistulas, extending to the natal cleft. The patient underwent en bloc resection of the fistulas which were in direct continuity with the middle rectum. Histological examination revealed a mucinous colonic adenocarcinoma. Abdominal CT and colonoscopy revealed an extramural residual rectal mass. The patient refused a radical colorectal operation. Three years later, because of fistula recurrence, he underwent loop sigmoidostomy and radical en bloc excision of the perianal fistula and rectum, with immediate reconstruction by bilateral gluteal flaps. The patient was discharged on the 12th postoperative day, refusing adjuvant radiotherapy. We present this rare malignant entity, successfully treated by staged operations and without any adjuvant therapy.

Adenocarcinoma, Mucinous↗
PubMed2004

Long-term features of norovirus gastroenteritis in the elderly.

Noroviruses are important pathogens in both sporadic cases and outbreaks of gastroenteritis in humans. Noroviruses can affect individuals of all ages in a variety of settings, but are a particularly important cause of gastroenteritis in aged-care facilities. The relationship between clinical symptoms and norovirus excretion and the possible role of asymptomatic carriage of norovirus in the elderly are poorly understood. This study examined symptoms and norovirus excretion in elderly individuals associated with a norovirus outbreak in an aged-care facility. Ten individuals aged 79-94 years were recruited for the study. Nine were symptomatic and one was an asymptomatic contact who subsequently developed gastroenteritis. The 10 participants were interviewed regarding their clinical symptoms between two and six times over a three-week study period. One or more sequential faecal samples were collected from all participants over the same period and tested by reverse transcription-polymerase chain reaction for the presence of norovirus. Norovirus was detected in faecal samples from all 10 study participants and was commonly detected in formed stools. In the nine symptomatic participants, acute symptoms such as diarrhoea and vomiting had largely resolved by the third or fourth day of illness, but non-specific symptoms such as headache, thirst and vertigo could persist for as long as 19 days. Both acute and non-specific symptoms appeared to resolve and recur in some participants. The median excretion time for norovirus was 8.6 days (range 2-15 days) in symptomatic participants (N=5). There was no general relationship between the duration of norovirus excretion and the duration of either acute or non-specific symptoms. A faecal sample collected from the asymptomatic contact the day before gastroenteritis symptoms began was positive for norovirus, demonstrating prodromal excretion of norovirus. The results of this study indicate that infection control guidelines should consider both long-term excretion and prodromal excretion of norovirus, and the possibility that formed stools can contain norovirus. Furthermore, the care of elderly individuals recovering from a norovirus infection should take long-term non-specific clinical symptoms into account.

Aged↗
PubMed2001

Expression of Wnt genes in human colon cancers.

A polymerase chain reaction-based approach was used to study the expression of Wnt genes in human colon carcinoma tissue and normal colon mucosa. In a number of cases Wnts 2, 4, 5a, 6 and/or 7a were found to be more highly expressed in colon carcinoma tissue compared to surrounding normal-appearing mucosa from the same patients. Wnts 4, 5a, 6 and 7a, but not 2, were also found to be expressed in colon cancer cell lines. The increased levels of expression of these Wnt genes in tumor tissue may indicate their possible involvement in human colon tumorigenesis.

Cell Line↗
PubMed2000

Osteopenia in children and adolescents with hyperprolactinemia.

Three patients with hyperprolactinemia due to pituitary adenomas (two patients) or empty sella (one patient) and osteopenia are described. Their ages at presentation ranged from 8 to 17 years. Each patient was treated with cabergoline. Serum prolactin levels became normal in all patients within one month. Bone density and pubertal stage improved after 12 months of treatment.

Adolescent↗
PubMed1999

Intrasphenoidal encephalocele and spontaneous CSF rhinorrhoea.

Intrasphenoidal encephalocele is a rare clinical entity. In the international literature only 16 cases have been reported up today, with female predominance. Clinically they manifest at middle and advanced ages (40-67 years), when spontaneous CSF rhinorrhoea or recurrent meningitis occurs. We present our case, a 46 years old female, who had CSF rhinorrhoea from the right vestibule for 10 months. The diagnosis was based on the history and the high-resolution brain and skull base CT-scanning in conjunction with opaque fluid injection in the subarachnoidal space through a lumbar puncture. She was successfully treated with an operation, through an endonasal trans-ethmoid microendoscopic approach, using the Draf and Stammberger technique. We discuss the pathogenesis of the intrasphenoidal encephalocele, the existence of small occult defects in the skull base, which cause, at the middle and advanced ages, CSF fistula with spontaneous CSF rhinorrhoea and/or recurrent meningitis. Finally we emphasize the advantages of the endonasal surgical approach for the treatment of this condition.

Cerebrospinal Fluid Rhinorrhea↗
PubMed1998

Estimating urea clearance in patients on continuous ambulatory peritoneal dialysis: a multivariate analysis.

The purpose of this study was to determine if Kt/V urea in continuous ambulatory peritoneal dialysis (CAPD) could be estimated by a multivariate model based upon simple clinical observations. The study included 439 clearance studies in 301 CAPD patients followed in 8 dialysis centers. Weekly urea clearance, 24 h urine volume and 24 h drain volume were normalized to body water by the formulae of Watson (Kt/V, UV/V and DV/V respectively). Adequate dialysis was defined as Kt/V > or = 2.0 weekly. Subjects at 2 units were used to derive the models, while others were used for model validation. Stepwise multiple linear regression was performed on the derivation set (DS) to identify the clinical variables that correlated with Kt/V. The model was then used to estimate Kt/V for the validation set (VS). In the DS, 110 clearance studies were performed in subjects with residual renal function. Multiple linear regression showed that weekly Kt/V was defined by the expression: Kt/V=1.48 + 24.1 (UV/V) + 2.92(DV/V) - 0.049 (serum creatinine) (r=0.750, p<0.001). In 204 VS studies, the correlation between estimated and measured Kt/V was 0.633. There were marked differences in the proportion of adequately dialyzed patients when Kt/V estimated from the formula shown was <2.0, between 2.0 and 2.3, and >2.3 weekly (7.9%, 54.7% and 79.7%, respectively; p 2.3 weekly (8.1%, 68.8%, and 100%, respectively; p<0.001). The risk of low Kt/V can be estimated by multivariate linear models requiring only simple clinical measurements.

Female↗
PubMed1997

Serum albumin in continuous peritoneal dialysis: absence of universal predictors.

Factors shown to affect serum albumin concentration in continuous peritoneal dialysis (CPD) were compared between two CPD populations residing in Greece (patient n = 108) and the United States (patient n = 194). Compared to the U.S. group, the Greek CPD population had higher serum albumin levels (35.1 +/- 4.6 vs 33.9 +/- 5.0 g/L, p = 0.031), was older (61.2 +/- 12.0 vs 52.7 +/- 16.5 years, p < 0.001), and had a greater number of high or high-average peritoneal solute transport types (69.4% vs 52.1%, p = 0.003). The American CPD population had a higher number of diabetics (53.1% vs 27.8%, p < 0.001), higher total Kt/Vurea (2.06 +/- 0.57 vs 1.93 +/- 0.46 weekly, p = 0.046), and higher total creatinine clearance (76.3 +/- 38.7 vs 63.4 +/- 23.5 L/1.73 m2 weekly, p < 0.001), while normalized protein nitrogen appearance values were comparable (0.95 +/- 0.21 in the Greeks vs 0.94 +/- 0.22 g/(kg x 24 hr) in the Americans, NS). A logistic regression model developed in the United States identified advanced age, diabetes, and high/high-average peritoneal solute transport as the predictors of hypoalbuminemia (serum albumin < 35 g/L). This model generated the following areas with 95% confidence intervals (CI) under the receiver operating characteristic (ROC) curve: in the Greek CPD population, ROC area 0.594 (95% CI 0.486-0.702); in the American CPD population, ROC area 0.850 (95% CI 0.810-0.890). In Greek CPD patients serum albumin appears to be affected by factors other than those identified in North America. This complicates comparisons of serum albumin, and probably morbidity and mortality, between CPD populations residing in different parts of the world.

Creatinine↗
PubMed1996

Fractional urea clearance in continuous ambulatory peritoneal dialysis: effects of volume disturbances.

The effects of volume disturbances on the KT/V were investigated prospectively in 133 consecutive urea clearance studies on patients on continuous ambulatory peritoneal dialysis (CAPD). Four subjects (group A) had fluid loss (actual weight < dry weight), 57 (group B) were studied on the basis of their dry weight, 58 (group C) had moderate fluid excess (0.5% of dry weight), and 14 patients (group D) had severe fluid excess (> 5% of dry weight). The KT/V was calculated on the basis of dry weight and actual weight with V obtained from the Watson anthropometric formulae which were applied either uncorrected or with a correction for changes in body water from dry weight conditions. The groups compared by variance analysis. The following weekly KT/V estimates were obtained: (1) using dry weight V: group A 1.81 +/- 0.17, group B 2.0 +/- 0.59, group C 1.79 +/- 0.46, group D 1.85 +/- 0.37 (no difference between groups); (2) using uncorrected actual weight V: group A 1.85 +/- 0.15, group B 2.05 +/- 0.59, group C 1.77 +/- 0.45, group D 1.78 +/- 0.37 (group B had a higher KT/V than group C, p < 0.05), and (3) using corrected actual weight V: group A 1.93 +/- 0.14, group B 2.05 +/- 0.59, group C 1.70 +/- 0.43, group D 1.63 +/- 0.36, (group B had a higher KT/V than either group C or group D, both at p < 0.01). In CAPD, fluid deficit is rare and causes a small increase in KT/V, whereas fluid retention is frequent and causes a decrease in KT/V. This decrease is pronounced in patients with severe fluid excess. The uncorrected Watson formulae underestimate V and, consequently, overestimate KT/V in CAPD patients with fluid excess.

Aged↗
PubMed1996

Cisplatin and continuous infusion of fluorouracil followed by radiation and weekly carboplatin in the treatment of locally advanced head and neck cancer: a Hellenic Cooperative Oncology Group study.

Induction chemotherapy followed by radiation has been extensively studied in an effort to improve local control and possibly overall survival of patients with locally advanced head and neck cancer. From June 1989 until May 1991, 39 patients with locally advanced squamous cell carcinoma of the head and neck (SCCHN) were treated with 3 cycles of induction chemotherapy, consisting of cisplatin (100 mg/m2 d 1) and fluorouracil (1000 mg/m2 d 2-6) followed by radiation potentiated by weekly administration of carboplatin (60 mg/m2). Surgery was performed in selected patients with residual disease after the combined modality approach. Four cycles of adjuvant chemotherapy with carboplatin (325 mg/m2) and bleomycin (15 u) were administered in those patients who demonstrated a partial response after locoregional treatment. There were 36 men and 3 women with a median age of 56 (range 39-74) years and Karnofsky performance status of 70 (range 60-100). The primary site of the tumor was nasopharynx (8), oropharynx (8), hypopharynx (3), oral cavity (4), larynx (13), paranasal sinus (2), and salivary glands (1). Thirty-two (82%) patients presented with stage IV disease. After the completion of induction chemotherapy, 14 (36%, 95% CI 21-53%) patients achieved a complete response (CR). This CR rate was increased to 56% (95% CI, 42-74%) after locoregional treatment. Main toxicities included nausea/vomiting (56%), leukopenia (40%), anemia (30%), thrombocytopenia (10%), stomatitis (28%), diarrhea (17%), and alopecia (12%). Median relapse-free survival was 18 (1-50) months, median time to progression was 13 (0.3-58.5) months, and median survival 19 (0.3-59) months. Induction chemotherapy with cisplatin and fluorouracil followed by radiation potentiated with carboplatin is feasible. However, this combined modality approach, as applied in the present study, does not appear to yield superior results than those reported with chemotherapy followed by radiation alone.

Animals↗
PubMed1995

Cross-sectional analysis of erythropoietin use in CPD: its relation to azotemic index clearances.

The association between the use of erythropoietin and urea or creatinine clearance was studied in two populations on continuous peritoneal dialysis (CPD) residing either at an altitude of 1600 m (n = 194) or at sea level (n = 108). Among peritoneal and total KT/V urea and creatinine clearance (CCr) indices, only total CCr was lower in the high altitude group receiving erythropoietin than in the corresponding group not receiving erythropoietin (68.0 +/- 34.9 vs 82.9 +/- 40.9 L/1.73 m2 weekly, p < 0.01). However, 24-hour urine volume and urinary KT/V urea and CCr were consistently lower in the groups receiving erythropoietin than in those not receiving erythropoietin. Total weekly KT/V urea < or = 1.70 and CCr < or = 52 L/1.73 m2 were considered indicators of inadequate CPD. Although the percent of patients receiving erythropoietin did not differ overall between groups with adequate and those with inadequate CPD, a trend towards more frequent use of erythropoietin was found in the sea level group with inadequate CCr versus the group with adequate CCr (28.2% vs 16.9%, p = 0.084). In CPD decreased renal function is associated with more frequent use of erythropoietin. Whether inadequate total urea or creatinine clearance is also associated with more frequent erythropoietin use requires further study.

Altitude↗
PubMed1994

Extragonadal choriocarcinoma in a patient with Down syndrome.

There are several reports suggesting that there is a higher incidence of leukemia and testicular cancer in patients with Down syndrome. Fifteen patients with Down syndrome and testicular cancer were previously reported. The median age at diagnosis of testicular cancer was 18 years, (range: 3-45). The histologic subtypes were seminoma in 9 patients, not specified in 2 patients, and 1 patient each of adenocarcinoma, yolk sac, embryonal, and teratocarcinoma. In this article we describe a case of extragonadal choriocarcinoma in a patient with Down syndrome. To our knowledge, this is the first case ever reported. The patient had a complete remission following chemotherapy with cisplatin, etoposide, and bleomycin and is disease-free with a follow-up of 32 months. Patients with Down syndrome and advanced testicular cancer should be treated with potentially curative chemotherapy.

Abdominal Neoplasms↗
PubMed1993

The effect of simvastatin on dyslipemia in continuous ambulatory peritoneal dialysis patients.

The efficacy of simvastatin, an inhibitor of HMG-CoA reductase, was evaluated in 14 nondiabetic hypercholesterolemic continuous ambulatory peritoneal dialysis (CAPD) patients with or without hypertriglyceridemia. Following a hypolipemic diet for 6 weeks, simvastatin was administered at a dose of 10 mg/day for 6 months. After 6 weeks on simvastatin, cholesterol was reduced by 22% (p < 0.001), triglycerides by 24% (p < 0.001), low-density lipoprotein (LDL) by 27% (p < 0.001), while high-density lipoprotein (HDL) increased by 18% (p < 0.005). These changes remained steady for 6 months. Apolipoprotein-B (Apo-B) was reduced by 17.8% (p < 0.0001), while Apo-A was stable. There were no liver function abnormalities observed. In 3 patients serum creatinine kinase (CK) was increased, and in 2 treatment was stopped. No new lens opacities or other side effects were detected. Simvastatin seems to be an effective and relatively well-tolerated drug for dyslipemias in CAPD.

Adult↗