Biomedical subjects
Publications and source records attributed to A Conte.
Aspergillus endocarditis is a rare event; a very few cases have been reported in injection drug users (IDUs) and patients infected with human immunodeficiency virus (HIV). We report 2 proven cases and 1 highly suggestive case of Aspergillus endocarditis in IDUs, 2 of whom were infected with HIV, and discuss some related clinical and pathogenic aspects.
The role of pH on the calcium dependence of nitric oxide synthase (NOS) of Cyprinus carpio brain was investigated. This fish is known to survive prolonged periods of hypoxia. Under this condition, cerebral blood flow is no longer regulated by nitric oxide (NO). Nitric oxide synthase activity is pH dependent in the range of pH between 7.4 and 6.2 with a decrease when tissue acidifies. At acidic pH, the dependence of the NOS activity on the free Ca(2+) concentrations changes considerably and shows an EC(50) of 0.13 microM at pH 7.1 and of 5.1 microM at pH 6.2 for the soluble enzyme. The variation in the Ca(2+) dependence with acidification is greater for the soluble than for the particulate enzyme. This may be the main factor protecting sudden NO formation mainly during anoxic-normoxic transitions.
Prenatal exposure to misoprostol has been associated with Moebius and limb defects. Vascular disruption has been proposed as the mechanism for these teratogenic effects. The present study is a multicenter, case-control study that was designed to compare the frequency of prenatal misoprostol use between mothers of Brazilian children diagnosed with vascular disruption defects and matched control mothers of children diagnosed with other types of defects. A total of 93 cases and 279 controls were recruited in eight participating centers. Prenatal exposure was identified in 32 infants diagnosed with vascular disruption defects (34.4%) compared with only 12 (4.3%) in the control group (P<0.0000001). Our data suggest that prenatal exposure to misoprostol is associated to the occurrence of vascular disruption defects in the newborns.
The phytate urinary levels in a group of active calcium oxalate stone formers were studied and compared with those found in healthy people. Urinary phytate was significantly lower for stone formers. If deficit of the capacity to inhibit crystallization of calcium salts is considered an important factor related to calcium stone formation, the excretion of low phytate amounts could be an important risk factor in the development of this type of renal calculi. The influence of dietary phytate on urinary excretion was also studied. Clearly maintenance of a phytate-free diet significantly decreased the urinary excretion of phytate (about 50% after 36 h). This demonstrated the importance of dietary phytate in maintaining adequate urinary levels to permit effective crystallization inhibition of calcium salts and consequently preventing renal stone development.
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Heparin, heparan sulfate and chondroitin sulfate were evaluated for their possible role on proliferation and differentiation of hematological precursor cells from cord blood. For these purposes, different concentrations of glycosaminoglycans were added to methyl-cellulose in colony assay performed with human cord blood derived cells. A volume of 10 microg/ml heparin induces a significant increase of both granulocyte-monocyte and granulocyte colonies, and a decrease of erythroid-colonies, more evident in the presence of 100 microg/ml. Heparan sulfate-treatment induces a significant increase of all granulocyte-monocyte colonies derived from CFU-granulocyte-monocyte, CFU-granulocyte and CFU-monocyte precursors. A significant decrease of multipotent cells was also observed. On the other hand, chondroitin sulfate induces an increase of granulocyte-colonies and a decrease of erythroid-colonies. Glycosaminoglycans with different structure may be useful to increase the number of specific colonies. The selective and differential binding of glycosaminoglycans with several growth factors and the regulation of their activities is discussed.
The crystallization of indinavir in synthetic urine at different pH values and indinavir concentrations was kinetically studied. It was found that precipitation time notably decreases at urinary pH values above 6.0. The effects of some products as potential crystallization inhibitors were studied. Some natural saponins such as escin and glycyrrhizic acid provoked a notable increase in the precipitation time of indinavir, this pointing out their possible use to prevent renal tubular solid deposition.
The authors propose a contribution to the possible revision of Chapters 1.4.1. and 1.4.2. of the International Animal Health Code (Code) of the Office International des Epizooties (OIE). In particular, data are presented to illustrate some of the inadequacies of both the rationale and the results of the method for risk assessment reported in the Code. The method suggested by the Code for risk assessment is based on the calculation of the 'probability of the occurrence of at least one outbreak' of a given disease following the importation of a given quantity of either live animals or animal products (unrestricted risk estimate). This is usually undertaken when dealing with rare events. For a country such as Italy, this method may not be particularly useful as the frequency of disease outbreaks is what should be estimated, so as to provide decision makers with appropriate and relevant information. Practical use of risk information generated by the use of the OIE risk assessment method for swine vesicular disease (SVD) would have encouraged the Chief Veterinary Officer of Italy to prohibit all imports of swine from the Netherlands and Belgium for at least two years in the early 1990s, with the consequential heavy economic losses for both Italy and the exporting countries. On the contrary, the number of actual outbreaks of the disease due to direct imports of swine from Member States of the European Union (EU), which occurred in Italy in 1992, 1993 and 1994 was very low (two to five outbreaks due to direct imports of swine from the Netherlands and one to two from Belgium). An example of a method for assessing the risks associated with high volumes of trade in commodities is also described. This method is based on the Monte Carlo simulation and provides the information required to evaluate the costs of the strategies compared. The method can be used to predict the number of outbreaks which are likely to occur following importation and enables a comparison to be made of alternative safeguards. This would lead to the selection of the most cost-effective one. The comparison is conducted using risk curves and allows a quantitative evaluation and comparison to be made of various scenarios, varying from an absence of safeguards to combinations of various safeguards.
OBJECTIVES: This paper presents the results of a test to globally determine the urinary risk factor of calcium stone formation in the evaluation of treatments using crystallization inhibitors, such as citrate and phytate. METHODS: Three groups of active calcium oxalate stone-formers have been selected. The lithogen urinary risk was determined using a specially designed disposable test before any medical treatment. After evaluation group I did not receive any treatment, group II was treated with potassium citrate and group III with a phytate-rich dietary complement. When 15 days had elapsed, the test to evaluate the risk of urinary calcium stone formation was applied again to the three groups. The main lithogenic biochemical parameters of each tested urine were also determined before and after treatment. RESULTS: An important number of calcium oxalate stone-formers with high urinary risk factor (positive test) became negative after medical treatment (52% of the citrate-treated patients and 50% of the phytate-treated patients), but only 7% of the untreated patients (1 patient) showed a decrease in their urinary risk factor for calcium stones (negative test) after 15 days had elapsed. When the treatment was not effective, in an important number of cases, the urine contained high levels of calcium or showed pH values greater than 6.5. CONCLUSION: From the obtained results it can be concluded that the test is useful to evaluate the efficacy of a given renal lithiasis medical treatment, and also the efficacy of the treatment of calcium oxalate renal lithiasis using crystallization inhibitors, such as citrate and phytate, in an important number of cases.
A 66-year-old man affected by polyostotic form of fibrous dysplasia in consequence of worsening of lower extremity bone pain aggravated by walking and concomitant increase of serum alkaline phosphatase and osteocalcin, was subjected first to a radionuclide study. Bone scan demonstrated a pathological uptake of the radiotracer in the craniofacial bones, right scapula, left and right posterior ribs, right hemipelvis and lower extremities confirming the diagnosis but establishing especially the extent of bone involvement, greater than expected on the basis of symptoms and X-ray findings, underlying the importance of nuclear medicine imaging in the assessment and follow-up of this rare disease.
Sera and blood from cattle and sheep were examined for the presence of Babesia and Theileria spp by microscopy and serology at the Parasitology Department of the Istituto Zooprofilattico Sperimentale of Abruzzo and Molise (IZSAM). Of the 47 bovine herds (323 animals) tested, 15 were found positive for Babesia bigemina and 1 for Babesia bovis. Two outbreaks occurred, one caused by B. bigemina and one by B. bovis. The B. bigemina outbreak occurred in Abruzzo and has been followed for two years. The isolate of B. bigemina was very pathogenic leading to the death of two cows out of 57. The vector responsible of the transmission appeared to be Rhipicephalus bursa. Parasites were observed in the erythrocytes for 30 days whereas sera were positive to indirect immunofluorescence (IFA) for at least one year. The B. bovis outbreak occurred in the province of Mantova (Northern Italy) in a group of 70 beef cattle imported from France. The infection resulted in the death of 5 animals and severe illness in another 6. In contrast with what occurred for Babesia infection, no clinical cases were recorded in cattle when species of Theileria were detected by microscopy. Of the 24 bovine herds (252 animals) tested for Theileria, 21 were found positive for the T. "sergenti"/buffeli/orientalis group. Single and mixed infection of T. "sergenti" and T. buffeli/orientalis were detected in herds of cross-bred cattle from Abruzzo and Marche. The parasites were identified by using a polymerase chain reaction which amplified DNA encoding p32/34. Most of the collected ticks (90%) were adults of R. bursa whereas the others were adults of Hyalomma detritum. During the period the animals have been observed (18 months), no clinical cases have been recorded and no associations have been found between blood abnormalities and animals found infected with Theileria. Prevalences of subclinically infected carriers increased from February till December (95.4%) even if the animals were indoors and no ticks were present. The prevalence then dropped dramatically six months later (76.7%). In calves less than 1 year old, the prevalence of infection significantly (p<0.05) increased with age, however intraerythrocytic stages of Theileria were found in the blood of three newborn calves (<7 days of age). Of the 18 ovine flocks tested for Babesia spp. (150 animals examined), 1 was positive for B. ovis and 2 for B. motasi. B. motasi infection was not associated with symptoms, while an outbreak of babesiosis caused by B. ovis occurred in Abruzzo. The infection resulted in the death of 3 animals (0.75% of the flock), two rams (20% of the total number) and a ewe, and severe illness in another 5 ewes (2% of the flock). Specimens of R. bursa and R. turanicus were collected from the infected animals. Of the 18 flocks (150 animals) examined, 12 were microscopically positive for Theileria spp. No clinical cases were recorded and identification at species level was not possible on the basis of morphological criteria. The prevalence distribution of infected herds and infected animals within herds and flocks have been calculated by a Monte Carlo simulation model, running 10,000 iterations. The most likely levels of prevalence of infected herds and infected animals within herds found for the species observed were as follows: 20% for B. bigemina with a prevalence within herd of 27%, 11% for B. bovis (18% within herd), 10% for Babesia ovis (19% within herd), 10% for B. motasi (17.5% within herd), 63% for Theileria in cattle (66% within herd) and 51% for Theileria in sheep (55% within herd).
Nitric oxide synthase (NOS) activity is found both in soluble and in particulate fractions of the carp brain. The Km values for arginine are 2.8+/-0.5 and 3.3+/-0.4 microM for the soluble and particulate fractions, respectively. K for NG-monomethyl-L-arginine inhibitor are 2.6+/-0.5 and 2.9+/-0.6 microM, and activation energy for the breakdown of the substrate-enzyme complex 8120+/-710 and 4620+/-450 cal per mole. Carp enzyme shows higher affinity than rat NOS for Ca2+ and for the competitive inhibitor 7-nitroindazole.
The changes in some nocturnal urine urolithogenic parameters in response to the extradietary ingestion of 2.16 g potassium citrate (20 meq) after dinner have been determined. The study included 15 patients (hypocitraturic calcium oxalate stone formers). On the basis of the different pH changes three groups have been differentiated. Different kinetics of citrate metabolism can justify the existence of these three groups. In general, a beneficial effect on urolithogenic parameters was confirmed, and a pH control of patients under treatment was recommended.
A simple test to evaluate the capacity of a urine to crystallize calcium salts is presented. The test is based on the fact that if a non-protected non-renewed surface remains in contact with a urine, sooner or later the contained supersaturated substances crystallize on it. Thus, by using an adequate surface, it is possible to derive a period within which a normal urine does not crystallize whereas a lithogenic urine induces the growth of calcium salts. The test was applied to urines of oxalocalcic stone-formers and healthy people and showed an excellent discrimination between clearly abnormal and healthy urines. Semiologic analysis of the data is also included.
Static and dynamic posturography was used to study patients who had experienced a prevalent laterally directed whiplash in a car accident. Results of both static and dynamic examinations were recorded. Findings showed that the whiplash injury had provoked shifting of the pressor center of the body toward a side that was at least indicative of the kind of cervical twist experienced, even when not corresponding to the prevalent direction of the trauma incurred.
The effect of minimum doses of extradietary potassium citrate ingestion on urolithogenic parameters has been studied. Separate urine fractions were collected in 24-hour periods. Five calcium oxalate stone formers have participated in the study. pH, calcium, citric acid, and the crystallization inhibitory capacity levels in fractional urine samples were determined before and during treatment. The most beneficial effect (increase in citraturia and crystallization inhibitory capacity) was produced by potassium citrate tablets ingested after dinner.
A comparative study between different etiological factors of calcium oxalate monohydrate (COM) and calcium oxalate dihydrate (COD) is presented. The most frequent alteration in COD urolithiasis was associated with hypercalciuria, whereas in COM urolithiasis was associated with urinary pH. A comparison between COM and COD groups of stone formers that exhibited 1, 2 or 3 alterations was performed. Thus, in individuals with two simultaneous alterations, the association between altered urinary pH and hypomagnesiuria was the most frequent in the COM group, whereas the association between hypercalciuria and altered urinary pH was most frequent in the COD group. In individuals with three simultaneous alterations, the association between hypercalciuria, hyperphosphaturia and hyperuricuria was most frequent in both COM and COD stone formers.