A multiplex PCR-based DNA assay for the detection of paraoxonase gene cluster polymorphisms.

Paraoxonase (PON) is a high-density lipoprotein (HDL) associated protein which is supposed to protect low-density lipoprotein (LDL) against oxidation and to play a role in the development of atherosclerosis. Interindividual variability in serum PON activity is attributable to common variants in components of the PON gene cluster on chromosome 7. We describe experimental conditions that permit the simultaneous determination of three common PON polymorphisms (PON1-192, PON1-55 and PON2-311) that are tightly associated with an increased risk of atherosclerosis. We used a multiplex PCR-based DNA assay using mismatch primers that introduce a unique recognition site for the endonuclease HinfI in the PCR products in case of presence of the R allele of PON 1-192, of the L allele of PON1-55 and of the S allele of PON2-311. The restriction analysis with HinfI allows to identify an electrophoretic band pattern which is specific for the combination of the three polymorphisms. This technique could be applied in the association studies aimed at assessing the role of PON and their polymorphisms in many clinical settings. In a preliminary study on a small population sample from south Italy about 10% of chromosomes exhibited the presumed risk-related haplotype R(192)/L(55)/S(311).

Extraction and determination of oxybutynin in human bladder samples by reversed-phase high-performance liquid chromatography.

A reversed-phase high-performance liquid chromatography method is described for the determination of oxybutynin (OXB) in human bladder samples. Following homogenization, tissue samples underwent double extraction with hexane and eventually were concentrated by freeze-drying before analysis. Chromatographic separation was performed with a mobile phase of acetonitrile-water-1 M ammonium acetate, pH 7.0 (85:13:2, v/v/v) at a flow-rate of 0.5 ml/min and double (electrochemical and UV) detection was applied. The retention time of oxybutynin eluting peak was around 18 min. Using a standard curve range of 10 to 500 ng/ml the quantification limit with electrochemical detection was 5 ng/ml with an injection volume of 100 microl. Within-day and day-to-day relative standard deviation values were 4.9 and 9.81%, respectively, while a 94% accuracy and a 72% recovery was attained. We applied this method to compare the OXB levels into bladder wall tissue samples after passive diffusion and after electromotive drug administration (EMDA), using a two-chambered poly(vinyl chloride) diffusion cell designed and developed in our laboratory. The results obtained show that EMDA enhanced OXB penetration into bladder wall and that this novel way of local drug administration can be potentially used in patients with neurogenic bladder dysfunction or urinary incontinence.

Fully automated assay for total homocysteine, cysteine, cysteinylglycine, glutathione, cysteamine, and 2-mercaptopropionylglycine in plasma and urine.

We describe a 6-min HPLC method to measure the total concentrations of the most important thiols in plasma and urine--cysteine, homocysteine, cysteinylglycine, and glutathione--as well as the concentrations in plasma and urine, respectively, of cysteamine and 2-mercaptopropionylglycine, two compounds used to treat disorders of cysteine metabolism. Precolumn derivatization with bromobimane and reversed-phase HPLC were performed automatically by a sample processor. Throughput was up to 100 samples in 24 h. The within-run CV ranged from 0.9% to 3.4% and the between-run CV ranged from 1.5% to 6.1%. Analytical recovery was 97-107%, with little difference between plasma and urine samples. The detection limit was approximately 50 nmol/L for all the analytes studied. Thiol concentrations were determined in the plasma of 206 healthy donors and in the urine of 318 healthy donors distributed for age and sex. Mean values of plasma cysteine and homocysteine were significantly lower in infants (ages, <1 y) compared with other age groups (P <0.005). In adults, mean plasma homocysteine values were higher in males than in females (9.2 vs 6.7 micromol/L, P <0.0001) and in the 6- to 10-year-old group (P <0.05). Mean values for glutathione and cysteinylglycine were not sex- and age-dependent. In urine, both cysteine and homocysteine showed a wide range of variation.

Multiple CT imaging in pressure sores.

In patients affected by pressure sores, bones can be reached easily by the infection. This suggested a new way for a more precise diagnostic evaluation, looking at the most recent technological knowledge, which can offer a better evaluation of single lesions for a better planning of surgical operations. The possibility of performing multiple imaging under a CT guide, as well as a simple technique for contrast permanence within the sore, led the authors to demonstrate the validity of modern CT scanning as a main diagnostic method.

Correlation between hyperglycemia and cerebral infarct size in patients with stroke. A clinical and X-ray computed tomography study in 104 patients.

Infarct area size on CT scan in 104 patients with ischemic stroke was compared with blood glucose levels and with other biological parameters (arterial pressure, hematocrit, consciousness impairment, clinical picture) during the acute stage. Infarct size was also compared with the presence and severity of diabetes mellitus and other risk factors. Infarct size was significantly correlated with hyperglycemia in the acute stage (p = 0.0348), regardless of the presence of established diabetes. These findings support the hypothesis that hyperglycemia directly increases regional brain damage due to acute vascular insufficiency. Infarct size was also correlated with the presence of atrial fibrillation, consciousness impairment, severity of clinical picture and neurological outcome.

[New imaging with computed tomography in dental implantology]. / Nuovo imaging con Tomografia Computerizzata nell'implantologia dentale.

The authors report on a new image processing technique, for the imaging of both mandible and maxilla, which is very useful for oral specialists, especially in pre- and postoperative protocols for dental implants. After performing very thin axial scans (1-2 mm) with overlapping and without gantry tilt, of the mandible and/or maxilla, the data are reconstructed with a Elscint DentaCT software. With this program, multiple panoramic alveolar views can be obtained in a very short time (about 5 minutes), with a focal plane which can be easily modified by the operator; these planes are parallel to the curved axis of maxilla or mandible. Furthermore, the operator can get multiple images absolutely cross-sectional to the curved axis of alveolar regions (radial sections) and can image the number of cross-sectional planes and the distance between them. In all studied patients (41 over the last 6 months, 66 images overall), DentaCT yielded an excellent representation not only of all anatomical structures but also of every single implant; this allowed a complete preoperative planning based on morphovolumetric, densitometric and spatial data, together with the correct evaluation of implant positioning and of osteointegration success.

[The spinal vacuum phenomenon. Radiographic and tomodensitometry aspects]. / Il fenomeno "vacuum" spinale. Aspetti radiografici e tomodensitometrici.

The spinal vacuum phenomenon is readily recognized by computed tomography: there fore its observation has become frequent enough. The side of the gaseous collection (intervertebral disk, vertebral body, apophyseal joint) depends on the disease inducing the phenomenon. Radiological and CT aspects of this findings are discussed. The usefulness of vacuum phenomenon in the diagnosis of several pathological conditions is examined.

[Iatrogenic changes in the dural sac. Radiologic semeiology]. / Alterazioni iatrogene del sacco durale. Semeiologia radiologica.

The authors have studied the pathological appearances of follow-up and post-operative radiculography. It has been possible to distinguish between lesions due to arachnoiditis and periduritis.

[Fogging effect in the ischemic cerebral infarction to computerized tomography (author's transl)]. / L'effetto maschera nell'infarto cerebrale ischemico alla tomografia computerizzata.

We have examined, with systematic serial computerized tomography (CT) studies, 6 patients with persistent ischemic cerebral infarction. The CT of the ischemic cerebral infarction shows, during the third week, an isodense area. We have called this phenomenon "fogging effect" because at this effect and the CT report could be negative. The possibility of a false negative can be avoided by a control study with contrast medium: the infarction has an intensive contrast enhancement.