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Biomedical subjects

A Karagiannis

Publications and source records attributed to A Karagiannis.

At least 19 recordsLinked to original sources
PubMed2006

Mortality rates of patients with a hip fracture in a southwestern district of Greece: ten-year follow-up with reference to the type of fracture.

Increased mortality after a hip fracture has been associated with age, sex, and comorbidity. In order to estimate the long-term mortality with reference to hip fracture type, we followed 499 patients older than 60 years who had been treated surgically for a unilateral hip fracture for 10 years. At admission, patients with femoral neck fractures (n = 172) were 2 years younger than intertrochanteric patients (77.6 +/- 7.7 [SD] vs. 79.9 +/- 7.4 [SD], P = 0.001) and had a greater prevalence of heart failure (57% vs. 40.3%, P = 0.03). Similar mortality rates were observed at 1 year in both types of fracture (17.9% vs. 11.3%, log rank test P = 0.112). Mortality rates were significantly higher for intertrochanteric fractures at 5 years (48.8% vs. 34.7%, P = 0.01) and 10 years (76% vs. 58%, P = 0.001). Patients 60-69 years old with intertrochanteric fractures had significantly higher 10-year mortality than patients of similar age with femoral neck fractures (P = 0.008), while there was no difference between the groups aged 70-79 (P > 0.3) and 80-89 (P = 0.07). Women were less likely to die in 5 years (relative risk [RR] = 0.57, 95% confidence interval [CI] 0.41-0.79, P = 0.0007) and 10 years (RR = 0.65, 95% CI 0.49-0.85, P = 0.002). Age, sex, the type of fracture, and the presence of heart failure were independent predictors of 10-year mortality (Cox regression model P < 0.0001). The intertrochanteric type was independently associated with 1.37 (95% CI 1.03-1.83) times higher probability of death at 10 years (P = 0.002). In conclusion, the type of fracture is an independent predictor of long-term mortality in patients with hip fractures, and the intertrochanteric type yields worse prognosis.

Age Factors↗
PubMed2000

Sedation for vitreoretinal surgery: a comparison of anaesthetist-administered midazolam and patient-controlled sedation with propofol.

Local anaesthesia is increasingly being used for vitreoretinal surgery, but the optimal technique for sedation remains unclear. Anaesthetist-administered midazolam, which is often used, was compared in this study to patient-controlled sedation with propofol in 43 patients undergoing 50 vitreoretinal procedures. A variety of patient, anaesthetist and surgical endpoints were measured. There were no significant outcome differences between the two agents except that midazolam produced more amnesia for the local anaesthetic eye block. However, several outcomes and the observations in patients who experienced both agents showed a trend in favour of propofol for intraoperative sedation. We conclude that both approaches are safe and that patient-controlled sedation with propofol is at least as satisfactory as anaesthetist-administered midazolam.

Procedural Sedation↗
PubMed1997

High-performance liquid chromatography of the renal blood flow marker p-aminohippuric acid (PAH) and its metabolite N-acetyl PAH improves PAH clearance measurements.

PAH (N-(4-aminobenzoyl)glycin) clearance measurements have been used for 50 years in clinical research for the determination of renal plasma flow. The quantitation of PAH in plasma or urine is generally performed by colorimetric method after diazotation reaction but the measurements must be corrected for the unspecific residual response observed in blank plasma. We have developed a HPLC method to specifically determine PAH and its metabolite NAc-PAH using a gradient elution ion-pair reversed-phase chromatography with UV detection at 273 and 265 nm, respectively. The separations were performed at room temperature on a ChromCart (125 mmx4 mm I.D.) Nucleosil 100-5 microm C18AB cartridge column, using a gradient elution of MeOH-buffer pH 3.9 1:99-->15:85 over 15 min. The pH 3.9 buffered aqueous solution consisted in a mixture of 375 ml sodium citrate-citric acid solution (21.01 g citric acid and 8.0 g NaOH per liter), added up with 2.7 ml H3PO4 85%, 1.0 g of sodium heptanesulfonate and completed ad 1000 ml with ultrapure water. The N-acetyltransferase activity does not seem to notably affect PAH clearances, although NAc-PAH represents 10.2+/-2.7% of PAH excreted unchanged in 12 healthy subjects. The performance of the HPLC and the colorimetric method have been compared using urine and plasma samples collected from healthy volunteers. Good correlations (r=0.94 and 0.97, for plasma and urine, respectively) are found between the results obtained with both techniques. However, the colorimetric method gives higher concentrations of PAH in urine and lower concentrations in plasma than those determined by HPLC. Hence, both renal (ClR) and systemic (Cls) clearances are systematically higher (35.1 and 17.8%, respectively) with the colorimetric method. The fraction of PAH excreted by the kidney ClR/ClS calculated from HPLC data (n=143) is, as expected, always <1 (mean=0.73+/-0.11), whereas the colorimetric method gives a mean extraction ratio of 0.87+/-0.13 implying some unphysiological values (>1). In conclusion, HPLC not only enables the simultaneous quantitation of PAH and NAc-PAH, but may also provide more accurate and precise PAH clearance measurements.

Biomarkers↗
PubMed1996

Angiotensin converting enzyme gene polymorphism is not related to essential hypertension in a Greek population.

Studies in various ethnic groups have shown contradictory evidence on the association of the angiotensin converting enzyme (ACE) insertion/ deletion (I/D) polymorphism with essential hypertension. In addition, mistyping of the insertion allele in heterozygotes has been reported. We analyzed the ACE genotype of 98 hypertensive and 84 normotensive subjects of Greek origin. Genomic DNA was extracted from blood samples and amplified by polymerase chain reaction (PCR). PCR primers were flanking the polymorphic region in intron 16 of the ACE gene. To avoid mistyping of heterozygotes, samples with the DD genotype were also amplified with primers that detect only the insertion allele. The distribution of the DD, ID, and II ACE genotypes was 30, 45, and 23 in hypertensive patients and 29, 40, and 15 in normotensive subjects, respectively. The estimated frequency of the insertion allele was 0.45 in hypertensive and 0.42 in normotensive subjects. The difference was not statistically significant. The results indicate a lack of association between ACE I/D polymorphism and essential hypertension in this Greek population, suggesting that other genes must contribute to the pathogenesis of hypertension.

Alleles↗
PubMed1996

Mobile retinal photography. A means of screening for diabetic retinopathy in aboriginal communities.

BACKGROUND: Mobile fundus photography undertaken by Aboriginal health workers has been suggested as a practical and effective method of screening for diabetic retinopathy among Aboriginal and Torres Strait Islander communities. METHODS: A pilot study was undertaken to demonstrate that interpretable colour slides of the retina could be produced by Aboriginal health workers trained over a two-week period. RESULTS: Of 47 subjects, 36 (76.6%) had interpretable retinal photographs. CONCLUSIONS: These findings warrant further evaluation as to the benefits and cost effectiveness of mobile retinal photography.

Australia↗
PubMed1995

Laser treatment in urology: our experience with neodymium:YAG and carbon dioxide lasers.

Laser surgery is currently considered as an effective alternative in the treatment of several urological diseases. We report on our three-year experience treating recurrent superficial low grade bladder carcinoma in 80 patients using Neodymium: YAG (Nd:YAG) laser. A decrease in local tumour recurrence rate (11%) was observed, but the overall not treated area recurrence was 45%. No complications were noted when the procedure was carried out on outpatient basis. Furthermore, we have been treating successfully urogenital condylomata using Nd:YAG and carbon dioxide (CO2) lasers in 364 patients. In addition we describe the use of Nd:YAG laser in the percutaneous treatment of a patient with bilateral transitional cell carcinoma of the renal pelvis.

Adult↗
PubMed1995

Carcinosarcoma of the bladder.

We present a case of carcinosarcoma of the bladder, the first in our experience. This tumour is generally considered to be a rare one, has uncertain aetiology and poor prognosis. At present, radical cystectomy is the treatment of choice.

Aged↗
PubMed1995

Percutaneous transluminal renal angioplasty in patients with renovascular hypertension: long-term results.

This study evaluated the long-term effects of percutaneous transluminal renal angioplasty (PTRA) on blood pressure and renal function in patients with renovascular hypertension. Seventy-eight patients with hypertension and unilateral or bilateral stenoses of the renal arteries (16 with fibromuscular dysplasia and 62 with atherosclerosis) were studied. All patients with fibromuscular dysplasia (group A) had normal renal function, while 27 of the 62 patients with atherosclerosis (group B) presented with various degrees of renal failure. PTRA was technically successful in 87.5% patients of group A. The overall technical success rate (complete plus partial) was 72.3% (55/76 renal arteries) in group B. Mean follow-up (range) in months was 42 (12-108) for group A and 39 (13-106) for group B. After successful PTRA, the overall benefit rate (cure plus improved) for hypertension was 100% in group A; 10 of 14 patients were cured and 4 of 14 were improved. In group B, the overall benefit rate was 70.8%; 9 of 48 were cured and 25 of 48 were improved. PTRA was technically successful in 18 of 27 patients with renal failure. Renal function improved in 4 of 18 patients, remained stable in 9 of 18, and deteriorated in 5 of 18 patients. The above results suggest that PTRA is an effective method for the long-term management of patients with renovascular hypertension, although the results were less favorable in the presence of bilateral renal artery stenoses: in addition to improved control of blood pressure, PTRA might improve renal function or delay its progressive deterioration.

Adult↗
PubMed1994

Spinal canal restoration by posterior distraction or anterior decompression in thoracolumbar spinal fractures and its influence on neurological outcome.

Thirty consecutive patients who had suffered unstable fractures and dislocations of the thoracolumbar spine mostly associated with neurologic impairment and bony encroachment on the spinal canal were treated either with Harrington distraction rods combined with sublaminar wires or with the Zielke-VDS device. These patients were subsequently assessed for neurologic outcome, spinal canal clearance, sagittal and coronal spinal deformity correction preoperatively and postoperatively with a minimum follow-up of 26 months. In the follow-up evaluation, the patients who underwent surgery with Harrington rods showed an overall improvement of their neurologic function of 90.9%, whereas all patients who underwent the Zielke operation improved. Preoperatively, positive correlations were found between the level of injury and Frankel grades; the cord lesion tended to demonstrate more severe neurologic deficit when compared with cauda equina ones (P < 0.001). Furthermore, dislocation accompanying the injury resulted in a more severe neurological deficit (P < 0.05). Harrington rods and Zielke device offer sufficient initial correction of the frontal spinal deformity but did not significantly either restore or maintain sagittal plane alignment. The Harrington series showed an overall improvement of the segmental kyphosis of 26% (NS), with a subsequent loss of correction of 7.38% (NS) on the follow-up observation. The Zielke device produced an immediate, much better correction of the segmental posttraumatic kyphosis of 45% (NS), but a loss of correction of 22.9% (NS) was measured in the follow-up evaluation. Correction of the anterior and posterior vertebral height was shown to be better for the Zielke patient group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

The relationship between the sympathetic nervous system and the renin-angiotensin system in renovascular hypertension.

UNLABELLED: The aim of this study is to evaluate and compare the activity of the sympathetic nervous system and the renin-angiotensin system in patients with unilateral or bilateral renovascular hypertension. Plasma noradrenaline (plNA) levels and plasma renin activity (PRA) were measured simultaneously in blood samples obtained both from a peripheral vein and from the renal veins, during catheterization of the venous cava system, in 17 patients with unilateral (group A) and in 9 patients with bilateral renal artery stenoses (group B). RESULTS: peripheral plNA levels were elevated in 6/17 patients of the group A and 3/9 patients of the group B, while in the remaining 11/17 and 6/9 were normal, respectively. The comparison of plNA levels between the renal veins showed that in both groups plNA levels were higher in the renal vein of the ischaemic (group A) or the more ischaemic kidney (group B), and the difference was statistically significant. Renal vein renin ratio was above 1.5 in both groups. Renin hypersecretion from the ischaemic or the more ischaemic kidney compared to renin suppression from the normal or the less ischaemic kidney showed statistically significant difference.

Humans↗
PubMed1992

Effects of adrenaline infusion on serum thromboxane B2 and plasma beta-thromboglobulin levels in hypertensive and normotensive subjects.

Adrenaline was infused in incremental doses of 0.05 up to 0.1 microgram/kg/min over a 60-min period in nine patients with mild essential hypertension and six age-matched normotensive controls. Blood samples were drawn at preset time intervals and plasma adrenaline, platelet count, serum thromboxane B2 (TxB2) and plasma beta-thromboglobulin (beta-TG) were measured. Adrenaline levels (m +/- SEM) rose significantly, from 0.078 +/- 0.01 (baseline) to 0.902 +/- 0.03 ng/ml (60 min), in the hypertensive group; a similar increase was observed in the control group (from 0.049 +/- 0.007 to 0.877 +/- 0.03 ng/ml). Platelet count increased significantly at early time points and remained high throughout infusion in both groups (hypertensive from 250 +/- 25 to 305 +/- 24 x 10(3)/microliters, control from 219 +/- 16 to 260 +/- 18 x 10(3)/microliters). TxB2 levels likewise increased significantly from 15 minutes after initiation of infusion. In hypertensive subjects the mean resting value of 186 +/- 17 ng/ml rose to 312 +/- 42 ng/ml, while in control subjects the resting value of 174 +/- 29 ng/ml rose to 286 +/- 32 ng/ml. Baseline levels of TxB2 were found to be higher in the hypertensive patients but not significantly. beta-TG levels increased from an initial value of 43.84 +/- 3.69 ng/ml to 59.5 +/- 4.69 ng/ml at 60 min in the hypertensive group, while a similar change from 28.7 +/- 19.2 ng/ml to 40.36 +/- 3.16 ng/ml was observed in the control group. These changes were significant, as was the difference between basal values in the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Non functioning adrenocortical carcinoma. A rare case.

Adrenocortical carcinoma is a rare tumor and experience in its diagnosis and treatment is limited. We present a case of non functioning adrenocortical carcinoma in which the pre-operative diagnosis of a kidney tumor had been made and a radical nephrectomy was performed.

Adrenal Cortex Neoplasms↗