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Biomedical subjects

G Georgescu

Publications and source records attributed to G Georgescu.

At least 19 recordsLinked to original sources

Cytomegalovirus cholangitis presenting with recurrent hemobilia.

Cytomegalovirus (CMV) cholangitis is a rare manifestation of CMV infection that has previously been described only in HIV-infected patients and solid-organ-transplant recipients. Reported here is a case of CMV cholangitis that occurred in a patient on chronic corticosteroid therapy who presented with recurrent hemobilia and biliary obstruction and was successfully treated with ganciclovir and cholecystostomy. A search of the medical literature revealed no previous case of this kind.

Adrenal Cortex Hormones↗

Echocardiographic findings in long-term, long-hour hemodialysis patients.

This article describes the echocardiographic structural and functional findings in a cohort of 30 patients on ten or more years of uninterrupted long-hour (24 hours per week dialysis schedule) hemodialysis (mean duration 187.7 months, range 120 to 299 months). Cardiac structural analysis was remarkable for the prevalence of LVH (76%), very rarely asymmetric (3%). Hemoglobin and (log) plasma renin activity were determinants of the LV wall thickness ratio (r = -0.57 and 0.54, p = 0.003 and 0.044 respectively). Markers of systolic contractile function were frequently normal (100% MVCFS; 85% FSI). Diastolic ventricular compliance was abnormal in 59% of patients. Blood pressure history appeared important in determining LVH, but office/ABPM measures of BP were not. Patients after parathyroidectomy (PTx) had a smaller LVPWTN (8.68 mm/m2 without PTx cf 7.01 mm/m2 after PTx, p = 0.036). Left ventricular cavity size was rarely enlarged (10%), with hemoglobin (r = -0.47, p = 0.012) and PTH (r = -0.65, p < 0.001) the major determinants of EDDN. Left atrial diameter was increased in 77% of patients. Cardiac valvular calcification was seen in 50% of patients. Our findings show that despite good BP control without recourse to antihypertensive drugs, LVH with good LV systolic function is very common in these long-survivors.

Aortic Valve↗

Efficacy of simultaneous determination of bone alkaline phosphatase mass concentration in serum and urinary excretion of pyridinium cross-links for detection of bone metastases.

OBJECTIVES: To examine the diagnostic validity of bone alkaline phosphatase (BAP) in serum (a marker of bone formation) and of urinary excretion of pyridinium cross-links (PYR) (a marker of bone resorption) for detection of bone metastases. DESIGN AND METHODS: Two heterogeneous immunoassays were employed for determination of BAP mass concentrations (Tandem-R Ostase) in serum and the urinary excretion of PYR (Collagen Crosslinks) in a consecutive series of 89 tumor patients examined by bone scintigraphy (with 99mTc-methylene diphosphonate). RESULTS: The discrimination power (as determined by Z score analysis) and the accuracy (as assessed by the area under the receiver-operating characteristic curve) was higher for BAP (0.84) than for PYR (0.76). Combination of both markers yielded a further increase of accuracy (0.89). There was a correlation (r = +0.422; p < 0.001) between the urinary excretion of pyridinium cross-links and bone alkaline phosphatase mass concentrations in the whole of 89 patients examined. In 14 (16%) of 89 patients bone alkaline phosphatase values were within the reference interval in spite of total alkaline phosphatase activity being increased; this indicates a higher diagnostic specificity of bone alkaline phosphatase (compared with total alkaline phosphatase) with respect to detection of bone metastases. CONCLUSION: Simultaneous assessment of bone formation by BAP and of bone resorption by PYR provides a suitable tool for detection of bone metastases.

Adult↗

Simultaneous assessment of bone collagen synthesis and degradation in patients with different malignant tumours. Comparison with the results of 99mTc-methylene bisphosphonate bone scintigraphy.

We report on the diagnostic validity of the serum concentrations of the C-terminal propeptide of type I procollagen (a marker of bone formation) and of the urinary excretion of deoxypyridinoline (a marker of bone resorption) in a consecutive series of 89 tumour patients who were routinely examined by 99mTc-methylene bisphosphonate bone scintigraphy for detection of bone metastases. Z score analysis reveals that the discriminating power of deoxypyridinoline is superior to that of calcium excretion whereas the discriminating power of the C-terminal propeptide concentrations is inferior to that of bone alkaline phosphatase values. Accuracy (as assessed by the area under the receiver-operating characteristic curve) was 0.75 for deoxypyridinoline and 0.82 for the C-terminal propeptide. Combination of both markers did not yield an increase of accuracy (0.82) compared with the determination of the C-terminal propeptide concentrations alone. There was a correlation (r = +0.398; p < 0.0001) between C-terminal propeptide concentrations and deoxypyridinoline excretion values in the group of 89 patients examined. Further studies should be done to elucidate whether the determination of bone collagen turnover is suitable as a screening procedure for detecting bone metastases.

Adult↗

[Parametric representation of kidney function using 99mTc-mercaptoacetyltriglycine (MAG3)].

99mTc-mercaptoacetyltriglycine (MAG3) has recently been introduced for imaging kidney function. Due to the much lower radiation dose per MBq, the total administered activity can be much higher than in the case of 131I-ortho-iodo-hippurate (OIH). The improved counting statistics make this tracer useful for parametric imaging of the kidneys. To investigate this potential of MAG3, its kinetics was compared with that of the reference tracer OIH in 38 patients. Parameters of extrarenal tracer kinetics such as the distribution volumes, the whole-body elimination times and the clearance rates showed a good correlation; however, the clearance rate of MAG3 was always lower than that of OIH. The intrarenal kinetics was investigated using the transfer function which was calculated by deconvolution analysis of the renographic curves. Parameters of the transfer function such as the amplitude, extraction fraction and mean transport time demonstrated a high correlation between the two tracers. Since MAG3 seems to be suitable for parametric imaging of kidney function, parametric images of perfusion, uptake, extraction and transport times were calculated by deconvolution analysis of the MAG3 pixel-renograms in various renal disorders. The parameters were distributed homogeneously throughout the parenchyma of normal kidneys. In a kidney with a hemodynamically significant renal artery stenosis the perfusion parameter was decreased and the time parameter was prolonged. Further examples of a renal graft acute tubular necrosis, an obstructive uropathy, an obstructive nephropathy and of a horse-shoe kidney demonstrate that the parametric images are useful for quantitative investigation of regional renal function.

Humans↗

World health organisation inter-laboratory comparison study in 12 countries on quality performance of nuclear medicine imaging devices.

Twelve countries participated in the WHO intercomparison for which transmission CAP (College of American Pathologists) brain and CAP liver phantoms and emission London liver phantoms were used. A total of 157 imaging devices were tested. Overall results from the phantoms revealed a wide range of targets detected. For the CAP-phantoms target detectability dropped below 50% for target sizes less than 9 mm and below 60% for target contrast less than 0.84:1. On average one false positive and six false negative results were reported using CAP-brain phantoms and one false positive and one false negative result using CAP-liver phantoms. For the London liver phantoms containing the tissue equivalent rubber abdominal simulation the target of 1 cm was never visualised. Two targets in this phantom (2 cm and 2.5 cm) were correctly identified in 34% of studies and one of these targets in 52% of studies. Equivocal and false positive results were reported in 42%. The WHO inter-comparison demonstrated the need to establish new, or to improve the existing, quality control programmes.

Brain↗