Search PubMedSearch

Biomedical subjects

A De Santis

Publications and source records attributed to A De Santis.

At least 19 recordsLinked to original sources

Italian survey on comparative levofloxacin susceptibility in 334 clinical isolates of Pseudomonas aeruginosa.

A national survey on susceptibility patterns of 334 Pseudomonas aeruginosa isolates from intensive care units and hematology and oncology wards from 13 Italian hospitals compared the in vitro activity of levofloxacin, an injectable oral fluoroquinolone, to those of ciprofloxacin, ofloxacin, ceftazidime, imipenem, amikacin, and gentamicin. Amikacin and imipenem had the best susceptibility profiles. The activity of levofloxacin was superior to those of the other quinolones and was comparable to that of ceftazidime. The effect of levofloxacin in vitro on P. aeruginosa clinical isolates suggests that further clinical investigations are warranted.

Anti-Infective Agents

Delayed hypersensitivity to aminopenicillins is related to major histocompatibility complex genes.

BACKGROUND: Although in some cases delayed hypersensitivity may be observed, beta-lactam antibiotics frequently induce immediate allergic IgE-mediated reactions with the specificity localized in the acyl-side chain structure. Generally, delayed immunologic reactions are related to sensitized T lymphocytes and major histocompatibility complex restricted. OBJECTIVE: To investigate the prevalence of HLA class I and II antigens in patients with delayed hypersensitivity to aminopenicillins in order to evaluate a relationship between major histocompatibility complex immune response genes and aminopenicillins hypersensitivity. METHODS: We assessed 24 patients with history of delayed hypersensitivity to aminopenicillins using (1) skin test with penicilloyl polylysine, minor determinant mixture, benzylpenicillin, amoxicillin, and ampicillin; (2) patch tests with benzylpenicillin, amoxicillin, and ampicillin; (3) RAST for penicilloyls G and V; and (4) oral challenges with amoxicillin, ampicillin, and penicillin V in 18/24 patients. All patients were typed by microlymphotoxicity standard test for HLA class I and II antigens. Statistical analysis by chi2 test 2 x 2 contingency tables, according to Svejgaard, were used for comparison between patients and random Italian population (522 subjects). RESULTS: In the patients group we found higher prevalence of HLA A2 (12/24 = 50%, RR = 6.76 P < .001, EF = 0.425), DRw52 (20/24 = 83.3%, RR = 9.28, P < .001, EF = 0.74), and lower frequency of DR4 (3/24 = 12% ns). CONCLUSIONS: These data suggest that the immune mechanisms involved in adverse reactions to aminopenicillins in vivo are related to genetic markers of immune response and confirms that the presentation of penicillin-hapten determinants to lymphocyte is major histocompatibility complex restricted.

Adolescent

Most Helicobacter pylori-infected patients have specific antibodies, and some also have H. pylori antigens and genomic material in bile: is it a risk factor for gallstone formation?

Bile may contain a 130-kDa protein endowed with aminopeptidase activity and the ability to promote cholesterol crystallisation. As >90% of H. pylori strains have a similar peptidase activity, and half the isolates express a 110- to 140-kDa antigen, the CagA protein, we investigated a possible association between H. pylori infection and gallstones, and the presence in bile samples of factors related to H. pylori that could increase cholesterol crystallization. The prevalence of H. pylori infection was 82.1% in 112 patients with gallstones and 80.3% in 112 controls (NS). Fifteen bile samples out of 23 specimens from infected patients (65.2%) contained anti-CagA antibodies. A approximately 60-kDa antigen only reacting with an anti-CagA antibody was found in five bile samples (21.7%) from 23 infected patients. One bile sample (4.1%) contained ureA and cagA genes of H. pylori. The homology of CagA with the N-terminal sequence of aminopeptidase N was very low. We concluded that the presence of specific antibody to H. pylori in most bile samples tested and of an H. pylori putative antigen in a discrete number of cases may represent factors that increase the risk of gallstone formation.

Antibodies, Bacterial

Epidemiology and treatment of otitis media with effusion in children in the first year of primary school.

In this multicentre study we evaluated the prevalence and risk factors of otitis media with effusion (OME) in Italian school-children and the effectiveness of medical treatment of chronic OME with a new cephalosporin, ceftibuten. During two winter periods, 3413 children, aged 5 to 7 years, were examined for the presence of OME by means of pneumotoscopy and a portable, hand-held tympanometer. The prevalence of asymptomatic OME was 14.2%, with no difference as regards sex, age, month of examination or geographic area. Younger children had significantly more bilateral than unilateral effusion. A recent episode of acute otitis media and previous tonsillectomy or adenoidectomy were associated with an increased risk of OME in multivariate logistic regression models. The presence of OME was unrelated to such factors as birthweight, prematurity, sibling or parental history of allergy, duration of daycare attendance, family history of ear infections. After 12 weeks, 26.6% of children with OME still had middle-ear fluid: 52 were randomized to ceftibuten (9 mg/kg q.d. for 14 days) and 59 to no treatment (nasal saline drops allowed). Children treated with ceftibuten had a significantly better resolution of middle-ear effusion after 4 and 8 weeks. As mass screening programmes for OME in the year of school entry are questioned, a focus only on children with known risk factors seems advisable. Ceftibuten can be useful in reducing the duration of middle-ear effusion.

Ceftibuten

Neuropsychological outcome of operated cerebral aneurysms: prognostic factors on 148 patients.

OBJECTIVES: To analyse prognostic factors in patients operated upon for cerebral aneurysms. A previous investigation by our group showed that patients operated later than 10 days after bleeding have a worse neuropsychological prognosis, but the number of patients operated upon within 3 days was not sufficient. Here, a new sample of patients with early surgery is included in the analyses. MATERIAL AND METHODS: Patients numbered 148 (65 with ACoA, 39 with MCA, and 44 with PCoA aneurysms): 56 were operated within 3 days, 44 within 4-10 days, and 48 after at least 10 days from bleeding. A standardized battery of 13 neuropsychological tests was adopted: we considered both the number of defective scores and the average performance. RESULTS: Patients operated later than 10 days after bleeding had a worse prognosis than the 2 groups with early and intermediate surgery, which were not different. Aneurysm site was not relevant. Old age and low education were associated with a worse prognosis. Hunt and Hess scores at operation and post operation were also predictive of the outcome. CONCLUSION: On the whole, patients operated upon later than 10 days after bleeding have a less favourable prognosis than those with earlier operation timing.

Adolescent

[Evaluation of treatment results in patients operated for aneurysm].

The evaluation of the surgical results in patients operated on for intracranial aneurysms is still controversial, since a satisfactory method able to provide complete informations and ease to use is not still available. The more often used evaluation criteria provide standardized patterns, but the excessive simplifications affect the reliability of the final evaluation. Therefore, I suggest a brand new scale called Clinical Social Emotional Evaluation (CESE), based upon the following domains: neurological evaluation, psychomotor autonomy, return to prior job, behavioural and affective disorders, social reintegration and occurrence of seizures. In order to validate this scale, 190 patients operated on for intracranial aneurysms were assessed. Different scales provided different results. In detail, the number of the "best results" according to CESE was smaller (48%) when compared to the number provided by GOS (80%) and Rankin (62%). Nevertheless, the smaller amount of good results does not imply an overall worsening of the outcome. It is due to the different selection criteria employed by the diverse scales. Indeed, CESE selects groups of patients very homogeneously, whilst other scales include much more heterogeneous subjects. Thus, CESE would prove it-self to be a reliable, accurate and easy to use evaluation scale.

Humans

Mortality and morbidity in patients operated on for ruptured intracranial aneurysms.

It is generally agreed, mortality and morbidity rates, in patients operated on for ruptured intracranial aneurysm, strictly depend upon the state at admission. Nevertheless, a precise definition of surgical mortality is still not available. Even the term morbidity still remains rather controversial for the lack of accurate evaluation scales. The wide range of parameters, affecting the composition of sample and outcome of patients, such as age, blood at CT scan and atherosclerosis at angiography, makes harder a correct statistical analysis of mortality and morbidity. Moreover, the gap between bleeding and admission, the management and choice of treatment, the selection of unicentric or multicentric studies, the level of the hospital introduce even more striking bias errors. Recent papers reported concrete improvements obtained by means of both aggressive therapeutical behaviour and adequate intensive care management. Among factors, producing improvement of the overall outcome, have to be also reported the encouraging preliminary results supplied by the interventional neuroradiological techniques. However, the overall mortality rate of SAH remains high. Thus, a coded scheme for detection and prevention of risk factors significatively associated to mortality and outcome can be only worked out by employing an appropriate therapeutical behaviour and an adequate intensive care management. Furthermore, employment of feasible evaluation scales will be essential to point out the most accurate procedure for management and treatment of patients with intracranial ruptured aneurysm. We think CESE, developed by one of the authors, to be considered as an adequate method for the assessment of results at follow-up.

Aneurysm, Ruptured

Sonographic survey of the upper abdomen in 10 families of patients with immotile cilia syndrome.

Ten patients affected by the immotile cilia syndrome (ICS) and their families received an ultrasound examination of the upper abdomen to observe the possible familial occurrence of biliary, pancreatic, and splenic alterations. In 9 patients the liver was localized in the left hypochondrium, and in 1 patient there was an accessory spleen. In all the examined kin, the subdiaphragmatic organs were normally positioned. Two parents had an accessory spleen. We conclude that the supposed increased frequency of polysplenia, asplenia, and biliary atresia among ICS subjects and their kin is overestimated and based only upon anecdotal reports.

Abdomen

Gallstones and diabetes: a case-control study in a free-living population sample.

Data on the association between cholelithiasis and diabetes often are controversial and are mostly based on autopsies or on hospital series. Therefore, we designed a case-control study to determine the prevalence of diabetes mellitus in a group of subjects with gallstones or having undergone cholecystectomy (cases) and compared these with a control group of subjects without gallstones, selected during an epidemiological study performed on a free-living population sample. The subjects were matched for sex, age, and body mass index. We enlisted 336 cases and 336 controls, aged 30 to 69 years. All subjects with fasting glycemic levels of < 140 mg/dL and without a documented history of diabetes were submitted to a simplified oral glucose tolerance test (OGTT). All subjects who underwent OGTT were classified according to the National Diabetes Data Group (NDDG) criteria. The prevalence of diabetes in the subjects affected by gallstone disease was significantly higher than that in controls (11.6% vs. 4.8%; odds ratio [OR], 2.55; 95% confidence interval [CI], 1.39-4.67). Diabetes was more frequent in subjects with gallstone disease than in the control group, even according to sex (18.3% vs. 9.9% for men: OR, 2.03; 95% CI, 0.99-4.2; 9.3% vs. 2.6% for women: OR, 3.85; 95% CI, 1.4-10.6). We conclude that an altered glucose metabolism may increase the risk of developing cholelithiasis in certain subjects.

Adult

Chronic liver disease in the Alexandria governorate, Egypt: contribution of schistosomiasis and hepatitis virus infections.

BACKGROUND/AIMS: In Egypt chronic liver disease is customarily attributed to Schistosoma mansoni infection. Anti-HCV antibodies are highly prevalent among Egyptian blood donors, yet little is known about the risk factors, pathogenicity and virological features of HCV and its association with schistosomiasis. We studied 135 adult patients with chronic liver disease living in the Alexandria governorate, mostly in rural areas of the Nile Delta. METHODS: Evaluation included abdominal ultrasonography; detection of anti-HCV antibodies and markers of HBV and HDV infection; HCV-RNA assay by 5' untranslated region nested polymerase-chain-reaction and HCV genotyping by a line probe assay; serologic (anti-soluble egg antigen, anti-SEA) and parasitological examinations for Schistosoma mansoni infection; and liver biopsy, if not contraindicated. RESULTS: Ninety-one (67%) patients had anti-HCV and 107 (85%) anti-SEA, 32 (30%) of whom excreted schistosomal eggs in stools. In addition, 21 (16%) patients had HBsAg, 86 (64%) anti-HBc and four (3%) anti-delta. Thus, many patients had evidence of multiple infections, double in 66% (anti-HCV and anti-SEA), triple in 33% (anti-HCV HBsAg and anti-SEA). Based on our diagnostic criteria, 25 (19%) patients had schistosomal portal fibrosis (anti-HCV positive in eight), 24 (18%) chronic hepatitis (anti-HCV positive in 19), 76 (56%) cirrhosis (anti-HCV positive in 58) and 10 hepatic tumors (anti-HCV positive in six). At multivariate analysis, the presence of anti-HCV was independently associated with previous parenteral anti-schistosomal therapy, a history of hematemesis and seropositivity for anti-HBc. Fifty (55%) of 91 anti-HCV positive sera had HCV-RNA, in 41 cases classified as genotype 4a. Detection of HCV-RNA was associated with a more severe liver disease and occurred less frequently in patients with a history of schistosomiasis. CONCLUSIONS: HCV infection with genotype 4a is the main cause of severe chronic liver disease in Egypt, where it is highly associated with schistosomiasis.

Adult

Microbial detection by a glucose biosensor coupled to a microdialysis fibre.

The use of a glucose biosensor coupled to microdialysis sampling in a flow injection analysis system is described to follow the growth of Escherichia coli in a glucose-containing liquid culture medium. The experimental set-up permitted a throughput rate of 25 samples h-1. Growth curves were modelled by a modified Gompertz equation, which permitted the determination of lag time and maximum specific growth rate. The time required to produce an appreciable variation in the biosensor response (minimum detection time, MDT) was determined. A plot of MDT versus microbial concentration was found to be linear in the range 10(6)-10(10) colony forming units (cfu) ml-1. A microbial concentration of 10(6) cfu ml-1 can be detected after about 5 h.

Bacteriological Techniques

Schizophrenic symptoms and SPECT abnormalities in a coeliac patient: regression after a gluten-free diet.

A 33-year-old patient, with pre-existing diagnosis of 'schizophrenic' disorder, came to our observation for severe diarrhoea and weight loss. Use of single photon emission computed tomography, (99mTc)HMPAO SPECT, demonstrated hypoperfusion of the left frontal brain area, without evidence of structural cerebral abnormalities. Jejunal biopsy showed villous atrophy. Antiendomysial antibodies were present. A gluten-free diet was started, resulting in a disappearence of psychiatric symptoms, and normalization of histological duodenal findings and of (99mTc)HMPAO SPECT pattern. This is the first case in which, in an undiagnosed and untreated coeliac patient with psychiatric manifestations, the (99mTc)HMPAO SPECT demonstrated a dysfunction of frontal cortex disappearing after a gluten-free diet.

Adult

Characterization of a new TEM-derived beta-lactamase produced in a Serratia marcescens strain.

A natural TEM variant beta-lactamase was isolated from an epidemic strain of Serratia marcescens. Nucleotide gene sequencing revealed multiple point mutations located in the 42-to-44 tripeptide and positions 145 to 146, 178, and 238. In addition, a glutamic acid 212 deletion was also found. The purified enzyme was studied from a kinetic point of view, revealing the highest catalytic efficiency (k[cat]/Km) values for ceftazidime and aztreonam compared with the TEM-1 prototype enzyme. The in vitro resistance correlated with kinetic parameters, and the enzyme also mediated resistance to some penicillins and an ampicillin-clavulanic acid combination. The mutational and kinetic changes are discussed in relation to the three-dimensional crystallographic structure of the wild-type TEM-1 enzyme.

Amino Acid Sequence

Mechanisms involved in the in vitro modification of low density lipoprotein by human umbilical vein endothelial cells and copper ions.

In this study we evaluated the time course and mechanism of low density lipoprotein (LDL) oxidation induced by human umbilical vein endothelial cells (HUVECs), cell-free medium (CFM) and Cu2+. After incubating LDL (200 micrograms/ml) with HUVECs, CFM and Cu2+ (concentration adjusted to obtain the same degree of LDL modification as with HUVECs), the extent of LDL lipid peroxidation and apoprotein B modification was monitored at different times from 0 to 24 h. This involved evaluating the time course of LDL conjugated diene, peroxide, malonyldialdehyde (MDA), fluorescence, relative electrophoretic mobility (REM), vitamin E and monounsaturated and polyunsaturated fatty acids. After incubation with HUVECs, the LDL REM was significantly higher than that obtained in CFM (p < 0.01). When balanced for the same degree of LDL modification as obtained with HUVECs, Cu2+ gave a REM similar to that obtained with HUVECs. At the different times of incubation there was no statistical difference between conjugated diene and peroxide values after incubation with HUVECs and with CFM. The values obtained with Cu2+ were significantly higher than those obtained with HUVECs and CFM (p < 0.01). MDA and LDL fluorescence were significantly higher after exposure to HUVECs than to CFM (p < 0.01), values being similar to those obtained with Cu2+. There was no statistical difference between the values of LDL oleic, linoleic, arachidonic and eicosapentaenoic acids after incubation with HUVECs and CFM. Eicosatetraynoic acid (ETYA), a lipoxygenase inhibitor, determined dose-dependent reduction of MDA formation induced by the incubation of LDL with HUVECs; it did not affect LDL conjugated diene. ETYA did not have any effect on the MDA derived from LDL after incubation with Cu2+ or CFM. The results of this study demonstrate that, unlike Cu2+, the contribution of HUVECs to LDL modification does not involve only lipid peroxidation of the lipoprotein; it also includes intracellular radical and non-radical processes.

5,8,11,14-Eicosatetraynoic Acid

Purification and characterization of the reconstitutively active adenine nucleotide carrier from maize mitochondria.

The adenine nucleotide carrier from maize (Zea mays L. cv B 73) shoot mitochondria was solubilized with Triton X-100 and purified by sequential chromatography on hydroxyapatite and Matrex Gel Blue B in the presence of cardiolipin and asolectin. Sodium dodecyl sulfate-gel electrophoresis of the purified fraction showed a single polypeptide band with an apparent molecular mass of 32 kD. When reconstituted in liposomes, the adenine nucleotide carrier catalyzed a pyridoxal 5'-phosphate-sensitive ATP/ATP exchange. It was purified 168-fold with a recovery of 60% and a protein yield of 0.25% with respect to the mitochondrial extract. Among the various substrates and inhibitors tested, the reconstituted protein transported only ADP, ATP, GDP, and GTP, and was inhibited by atractyloside, bongkrekate, phenylisothiocianate, pyridoxal 5'-phosphate, and mersalyl (but not N-ethylmaleimide). Maximum initial velocity of the reconstituted ATP/ATP exchange was determined to be 2.2 mumol min-1 mg-1 protein at 25 degrees C. The half-saturation constants and the corresponding inhibition constants were 17 microM for ATP, 26 microM for ADP, 59 microM for GTP, and 125 microM for GDP. The activation energy of the ATP/ATP exchange was 48 kilojoule/mol between 0 and 15 degrees C, and 22 kilojoule/mol between 15 and 35 degrees C. Partial amino acid sequences showed that the purified protein was the product of the ANT-G1 gene sequenced previously (B. Bathgate, A. Baker, C.J. Leaver [1989] Eur J Biochem 183: 303-310).

Adenosine Diphosphate

Recurrent perimyocarditis following a non penetrating chest trauma. A case report.

A young man, after a non penetrating chest trauma, developed recurrent episodes of fever, chest pain, pleural and pericardial effusion, without laboratory evidence of viral infections, or positivity for conventional autoimmunity markers. A clearcut positivity for more specific cardiac autoantibodies, against Beta 1 adrenoceptors (AB1AA), was found (at all dilutions from 1:20 to 1:160). A full dosage of Prednisone rapidly relieved all symptoms, whereas antibiotic therapy had been previously uneffective. At a follow-up control after three months, the patient was healed and AB1AA were positive only at dilutions 1:20 and 1:40. As silent viral myocarditis was apparently ruled out by serological negativity for viral infections, it is possible that autoimmunity could have played a primary pathogenetic role for the development of pericarditis in this patient. Further work is needed to ascertain whether or not AB1AA detection could be a specific marker of cardiac autoimmunity phenomena.

Adult

Glutathione suppresses spontaneous activity in the frog spinal cord.

Spontaneous electrical activity in the isolated hemisected frog spinal cord increased in the presence of the SH reductant dithiothreitol (DTT) was reversibly suppressed by the oxidant 5-5'-dithio-bis-(2 nitrobenzoic acid) (DTNB) and was irreversibly suppressed by the sulphydryl modifying agents N-ethyl-maleimide (NEM) and monobromotrimethylammonio bimane. Glutathione (GSH), an important natural low molecular weight thiol, reversibly suppressed spontaneous activity. Cords pretreated with glutathione and successively exposed to NEM or bimane maintained their normal electrical activity. This indicates that GSH had interacted with the exposed sulphydryls and prevented their reaction with NEM or bimane. Incubation with bimane resulted in fluorescence-labelled neurones in the dorsal and ventral horns, whereas samples pretreated with NEM or with GSH were not labelled. Neurones appeared again fluorescent in cords preincubated with GSH and sequentially exposed to NEM or bimane. Both electrophysiological and histochemical methods indicate that exposed membrane sulphydryls are involved in the genesis and/or modulation of spontaneous electrical potentials.

Animals