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Biomedical subjects

L Manna

Publications and source records attributed to L Manna.

16 recordsLinked to original sources
PubMed2006

Deltamethrin-impregnated collars for the control of canine leishmaniasis: evaluation of the protective effect and influence on the clinical outcome of Leishmania infection in kennelled stray dogs.

A 2-year field study on kennelled stray dogs living in a highly endemic area of leishmaniasis was designed to evaluate whether deltamethrin-impregnated collars (Scalibor) Protector Band) could confer protection against leishmaniasis in this peculiar setting, and to assess differences in clinical outcomes between collared and uncollared dogs. A cohort of 120 clinically healthy and Leishmania-seronegative dogs was enrolled, 50% of which were collared before the 2003 transmission season, and then re-collared before the subsequent season. Collared and uncollared animals were allowed to live with infected dogs in same groups within the kennel. Follow-up included serological (IFAT) assessment twice a year with parasitological Leishmania confirmation, and clinical evaluation performed every 3 months on seroconverted dogs from both groups. Collar losses during the two seasons were high (35%). About 50% of enrolled dogs were lost at follow-up because of death or they were moved to other locations. After the 2003 season, cross-sectional serological examinations tested positive in 5 out of 44 collared animals (11.4%) and in 14 out of 34 controls (41.2%), with 72.3% estimated protection (P<0.005). After the 2004 season, 7/31 seronegative collared dogs seroconverted (22.6%) compared with 7/17 seronegative controls (41.2%), with 45.1% protection (P=0.15). At the end of the study, the cumulative rate of protection was 50.8% (P=0.005). At the clinical evaluation of 21 seroconverted dogs from both groups, canine leishmaniasis signs were significantly more frequent (90% versus 36%, P=0.017) and rapidly progressive in uncollared than in collared dogs. Reasons for such partial clinical protection in collared dogs may be found in the vector anti-feeding effect of protector bands, resulting in a lower number of infectious bites and, probably, in the reduction of antigenic stimuli necessary to shift toward a non-protective immune response.

Animals↗
PubMed2006

First detection of canine parvovirus type 2c in pups with haemorrhagic enteritis in Spain.

Canine parvovirus type 2 (CPV-2), the aetiological agent of haemorrhagic enteritis in dogs, includes three antigenic variants, types 2a, 2b and 2c. CPV-2c has been detected initially in Italy and subsequently in Vietnam. We report the first identification of this novel antigenic variant in Spain, where it caused an outbreak of fatal enteritis in basset hound pups in association with canine coronavirus type I and type II. We suggest that this new antigenic variant of CPV-2 could spread throughout Europe and that there is a subsequent need to update current CPV vaccines.

Animals↗
PubMed2005

Focused microwave-assisted extraction and LC determination of the active ingredient in naproxen-based suppositories.

A simple and rapid open-vessel focused microwave-assisted extraction (FMAE) method followed by LC analysis was developed for the determination of naproxen in suppositories. Parameters which might affect the FMAE method, such as nature and volume of the extraction solvent, temperature and extraction time were optimized. The extraction solvent consisted of methanol/sodium hydrogen carbonate (pH 8.7; 0.1 M) (50:50, v/v). Extractions were performed by reaching the target temperature of 70 degrees C in a 7 min linear ramp and then maintaining the target temperature for 3 min. Chromatographic analysis was performed on a Discovery RP-Amide C16 column (250 mm x 4.6 mm i.d., 5 microm particle size). The mobile phase consisted of acetonitrile/potassium dihydrogenphosphate (pH 3.0; 25 mM) (40:60, v/v). The complete analytical procedure was validated with regard to limit of quantification, linearity, precision and accuracy. The advantages of the proposed method in comparison to conventional methods are decreased extraction time, reduced solvent consumption and no further sample clean-up steps required before liquid chromatographic analysis.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2004

Formation and characterization of glutamate dehydrogenase monolayers on silicon supports.

In this paper we have tested two different procedures (the "three-step" and the "four-step" procedures) for the covalent immobilization of glutamate dehydrogenase (GDH) onto silicon supports. Atomic force microscopy (AFM), Fourier-transform infrared spectroscopy (FT-IR), fluorescence spectroscopy and an enzymatic assay were used to probe the structure and activity of the immobilized enzyme. Our results demonstrate that coupling through the "three-step" procedure does not significantly affect either the fold pattern or the activity of the enzyme, suggesting that this method could be ideally suited to the development of high quality monolayers for use in enzyme-based planar biosensors.

Biosensing Techniques↗
PubMed2003

RP-HPLC study of the degradation of diclofenac and piroxicam in the presence of hydroxyl radicals.

The effect of hydroxyl radical attack on two non-steroidal anti-inflammatory drugs (NSAIDs) was studied in vitro. Diclofenac and piroxicam were analysed by RP-HPLC after reaction with OH* free radicals to detect newly formed oxidation and/or degradation products. OH* free radicals were obtained by means of ferrous sulphate and ascorbic acid mixtures. During the reaction the mixtures were exposed to irradiation by a tungsten lamp to obtain an increased and more reproducible formation of hydroxyl radicals. The chromatographic profiles showed the formation of several new peaks for both diclofenac and piroxicam due to the presence of a number of degradation/oxidation products formed in the presence of OH* radicals.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2002

Development and validation of a reversed-phase liquid chromatographic method for the assay of lidocaine in aqueous humour samples.

A simple, fast and reliable reversed-phase liquid chromatographic method was developed for the assay of lidocaine in human aqueous humour samples. The samples were analysed without any preliminary treatment on a C8 column with UV detection at 225 nm. The mobile phase consisted of methanol/sodium dihydrogen phosphate (30 mM) containing sodium pentansulphonate (10 mM) adjusted to pH 2.5 with phosphoric acid (50:50 v/v). Validation of the method showed it to be precise, accurate and linear over the concentration range of analysis with a limit of detection of 0.2 microgml(-1). The limit of quantitation was 2.5 microgml(-1) with a relative standard deviation of 2.5%. Linear regression analysis in the range 2.5-60 microgml(-1) gave correlation coefficients higher than 0.999. No interference from three commonly co-administered drugs was observed. The method developed was applied to the analysis of lidocaine in aqueous humour samples in order to evaluate and compare the efficacy of two different forms of administration of lidocaine for topical anaesthesia in cataract surgery.

Aqueous Humor↗
PubMed2001

Linearly polarized emission from colloidal semiconductor quantum rods.

Colloidal quantum rods of cadmium selenide (CdSe) exhibit linearly polarized emission. Empirical pseudopotential calculations predict that slightly elongated CdSe nanocrystals have polarized emission along the long axis, unlike spherical dots, which emit plane-polarized light. Single-molecule luminescence spectroscopy measurements on CdSe quantum rods with an aspect ratio between 1 and 30 confirm a sharp transition from nonpolarized to purely linearly polarized emission at an aspect ratio of 2. Linearly polarized luminescent chromophores are highly desirable in a variety of applications.

Cadmium Compounds↗
PubMed2000

Shape control of CdSe nanocrystals

Nanometre-size inorganic dots, tubes and wires exhibit a wide range of electrical and optical properties that depend sensitively on both size and shape, and are of both fundamental and technological interest. In contrast to the syntheses of zero-dimensional systems, existing preparations of one-dimensional systems often yield networks of tubes or rods which are difficult to separate. And, in the case of optically active II-VI and III-V semiconductors, the resulting rod diameters are too large to exhibit quantum confinement effects. Thus, except for some metal nanocrystals, there are no methods of preparation that yield soluble and monodisperse particles that are quantum-confined in two of their dimensions. For semiconductors, a benchmark preparation is the growth of nearly spherical II-VI and III-V nanocrystals by injection of precursor molecules into a hot surfactant. Here we demonstrate that control of the growth kinetics of the II-VI semiconductor cadmium selenide can be used to vary the shapes of the resulting particles from a nearly spherical morphology to a rod-like one, with aspect ratios as large as ten to one. This method should be useful, not only for testing theories of quantum confinement, but also for obtaining particles with spectroscopic properties that could prove advantageous in biological labelling experiments and as chromophores in light-emitting diodes.

Journal Article↗
PubMed2000

Synthesis and structural characterisation of CdS nanoparticles prepared in a four-components "water-in-oil" microemulsion

Nanostructured semiconductor particles are currently under intense investigation because of their enhanced photoreactivity and photocatalytic properties due to the quantum-size effect and the dependence of the photophysical and photochemical properties on their size as it approaches the exciton diameter. This increasing interest has led to the development of several synthetic procedures to prepare and stabilise uniform crystallites. In this paper, we report a novel synthetic pathway to obtain cadmium sulphide (CdS) nanoparticles in a quaternary "water-in-oil" microemulsion formed by a cationic surfactant cetyltrimethylammonium bromide (CTAB), pentanol, n-hexane and water. The synthesis of CdS in this system is achieved by mixing two microemulsions containing Cd(NO3)2 and Na2S, respectively. The nanocrystals have been characterised by using UV--visible spectroscopy and Transmission Electron Microscopy to investigate the influence of various parameters of the particles' formation and stability in solution. Capping of nanoparticles with suitable organic molecules has been performed in order to increase their stability and afford solubility in a wide range of solvents.

Journal Article↗
PubMed1999

Amoxicillin sodium-potassium clavulanate: evaluation of gamma radiation induced effects by liquid chromatography on both the individual drugs and their combination.

The effects of gamma irradiation on the stability of potassium clavulanate, amoxicillin sodium and their combination were investigated. A decrease in purity and increase in degradation products up to 30 days after the irradiation were evaluated by reversed phase HPLC. The comparison between unirradiated and irradiated amoxicillin sodium, performed within 24 h following the irradiation process, showed no significant increase in the pre-existing impurities and no evidence of newly induced degradation products. On the contrary, an appreciable increase in the content of some impurities was evidenced 30 days after the irradiation. The chromatographic profile of irradiated potassium clavulanate showed the appearance of one unidentified new product and a slight increase of one pre-existing impurity. No further change in the impurity content was noted 30 days after the irradiation. The amoxicillin sodium-potassium clavulanate combination underwent the same kind of radiation induced degradation as the single compounds.

Amoxicillin↗
PubMed1997

Preliminary report of infection in dogs related to Ehrlichia equi: description of three cases.

The clinical course of naturally infected dogs with E. equi are described. Fever (up to 41 degrees C), depression, dysorexia and ascites were observed. Laboratory findings revealed mild anemia, inclusion bodies within neutrophils in one dog, thrombocytopenia, hypoproteinemia, hypoalbuminemia and in two dogs hyperglobulinemia. In acute and convalescent dogs sera antibody titers from 1:60 to 1:480 to E. equi using IFA test were detected. Clinical resolution was obtained with long-term doxycycline monohydrate therapy.

Animals↗
PubMed1988

Comparative analysis of autonomic and somatic dysfunction in chronic uraemia.

The relationship between autonomic dysfunction and peripheral somatic neuropathy was investigated in uraemics. The battery of autonomic tests included R-R interval variation test, deep breathing, Valsalva manoeuvre, heart rate and blood pressure responses to standing, and sustained handgrip. Maximum conduction velocity along sensory and motor fibres of the posterior tibial nerve was measured. An impairment of parasympathetic reflexes was more frequent than a sympathetic damage, but with no relationship to the degree of electrophysiological disturbances. Cardiovascular autonomic dysfunction and somatic neuropathy in uraemia result to be two different entities in incidence and perhaps in pathogenesis.

Adult↗
PubMed1986

Cardiovascular reflex tests. Assessment of age-adjusted normal range.

To assess the relationship between aging and autonomic control of heart rate and blood pressure, cardiovascular reflex tests were performed in 70 healthy volunteers in the age range 25-71 years. R-R interval variation, heart rate change with deep breathing, 30/15 ratio and blood pressure response to standing appeared significantly declining with age. For each test we calculated the P0.99 and P0.01 confidence limits for individual observations. On the other hand, Valsalva ratio and the blood pressure response to sustained handgrip appeared to be unrelated to age. These results suggest that there is an age-dependent degradation of the mechanisms involved in the cardiovascular reflexes. The assessment of age-adjusted normal values improves the criteria for delineating abnormal from normal results in individual testing of autonomic function.

Adult↗
PubMed1986

Serum thyroid hormones and thyroid hormone binding proteins in patients with completed stroke.

Thirty euthyroid patients hospitalized for completed stroke had serum thyroxine, triiodothyronine, thyroxine-binding globulin and thyroxine-binding prealbumin levels significantly decreased (p less than 0.01 to p less than 0.001) compared with 70 age- and sex-matched healthy controls. Admission serum thyroxine levels gave the best correlation with mortality (T4 less than 65 nmol/l = 100% mortality; 65-77 nmol/l = 38%; 78-90 nmol/l = 9%; greater than 90 nmol/l = 0%). In general, during hospitalization a progressive decrease in serum concentrations of these parameters was observed in the 11 patients who subsequently died, while there was a progressive increase in the 19 survivors. However, the most sensitive index of clinical recovery appeared to be prealbumin, since a decrease in prealbumin levels was observed in all subjects who died, and an increase in prealbumin was found in all survivors.

Aged↗
PubMedDate not supplied

Uremic vagal neuropathy: has parathyroid hormone a pathogenetic role?

Cardiac vagal reflexes were investigated in 19 dialysis patients, with the aim of verifying whether parathyroid hormone, proposed as an important uremic neurotoxin, plays a role in the development of uremic vagal neuropathy. The results indicate that parasympathetic control of heart function is frequently impaired in uremics. Plasma parathyroid hormone levels were significantly correlated with the time on dialysis. However, a correlation between autonomic disturbances and plasma parathyroid hormone concentrations was not found in this study.

Adult↗