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Biomedical subjects

A Pesce

Publications and source records attributed to A Pesce.

At least 55 records · Page 3Linked to original sources

The beta-lactamase problem: new therapeutic options.

As a consequence of their successful use in prophylaxis and therapy, bacterial resistance mediated by beta-lactamases is now widely diffused among beta-lactam antibiotics. Several effective strategies have been suggested in order to overcome this problem. One interesting option is offered by the development of a series of new beta-lactam compounds that possess a very high intrinsic stability to the hydrolytic action of the most common beta-lactamases. Among these molecules the oral third generation cephalosporins represent a significant breakthrough. Cefetamet pivoxil, because of its broad coverage of most gram-negative and gram-positive community acquired pathogens, rightly belongs to these new agents. The activity of cefetamet has been confirmed in a survey in Italy involving 4191 isolates. on this collection of strains cefetamet emerged as the most active in vitro compound, followed by cefixime, with all other comparative agents (cefuroxime, cefaclor, cephalexin, cefradoxil, ampicillin, amoxicillin-clavulanate, ampicillin-sulbactam, doxycycline, erythromycin and clindamycin) displaying lower eradication rates. According to the data gathered in the Italian survey, cefetamet can be considered the only compound, among those taken into consideration, that might be selected as the drug of choice in the empiric therapy of respiratory and urinary community-acquired infections. In fact, the prevalence of resistance to cefetamet in the most prevalent pathogens occurring in this setting is, at present, sufficiently low to render therapeutic failures, based on this parameter, highly improbable.

Anti-Bacterial Agents↗

[Muscular involvement in the course of AIDS. Anatomo-clinical study of 17 cases].

We report 17 patients seropositive for the human immunodeficiency virus, with muscle tissue involvement in different stages of the disease. Some patients are treated with azidothymidine (AZT). Others have no opportunistic infections. In all cases, there are some muscular symptoms such as progressive symetric and proximal muscular weakness with myalgias, elevated serum muscle enzymes, abnormal electromyogramma and very often a peripheral neuropathy. The muscle biopsy reveals the following features: rarely a focal muscular opportunistic infection in advanced stage of the disease is observed; a polymyositis is quite often the first clinical manifestation of the disease; a myopathy with mitochondrial involvement is observed in some of the AZT treated patients; some cachectic, under nourrished, bedridden patients present a type II muscle fiber atrophy. We conclude that a muscle biopsy could help us in our therapeutic planning directing us to a corticotherapy in the polymyositis, mitochondriopathies and wasting syndrome. Interruption alone of AZT or associated with a treatment by carnitine could allow remission of the muscular pathology.

Acquired Immunodeficiency Syndrome↗

[Kaposi disease and sex hormones: apropos of a case, review of the literature].

The authors report one case of AIDS-related-like Kaposi's sarcoma (KS) in a 59-year-old bisexual man without HIV-1 and HIV-2 infection. KS developed while the patient was receiving both androgen and steroid therapy for aplastic anemia, and regressed after their simultaneous interruption, despite the persistence of aplastic anemia. The authors discuss the etiology of KS in the patient, with a special regard to a putative role of the androgen therapy. The authors examine the arguments of the literature, probably underestimated, that may suggest a role of sex hormones in the pathogenesis of KS.

Anemia, Aplastic↗

Pancreatitis in patients with end-stage renal disease.

In a population of 716 patients with end-stage renal disease (ESRD), 46 patients (6.4%) were identified as having pancreatitis. Pancreatitis was significantly more common in those with alcohol abuse, systemic lupus erythematosus (SLE), and polycystic kidney disease. It was not significantly associated with hyperlipidemia, biliary tract disease, or hypercalcemia. Acute pancreatitis occurring before the patient developed ESRD was mainly alcohol-related and did not appear to be a significant risk factor for future episodes of pancreatitis during dialysis. Chronic calcific pancreatitis diagnosed before ESRD was almost invariably due to alcohol abuse, and tended to be a marker for recurrent acute exacerbation after development of ESRD, whether alcohol consumption continued or not. Pancreatitis occurring for the first time after ESRD in patients on dialysis was generally benign, and was usually accompanied by an uneventful recovery and few recurrent episodes. However, a significant elevation of the calcium x phosphate product was observed in these patients, occurring in about half the patients without any known precipitating factor. After kidney transplantation, the development of pancreatitis was associated with higher morbidity and mortality. Chronic calcific pancreatitis diagnosed after ESRD occurred only in patients with SLE; reported here for the first time, it may be a manifestation of long-standing disease, chronic steroid therapy, or both.

Acute Disease↗

Stability in the presence of widespread beta-lactamases. A prerequisite for the antibacterial activity of beta-lactam drugs.

Bacterial resistance to the beta-lactam drugs is extremely widespread, as a result of extensive drug use. Loss of susceptibility is primarily attributable to hydrolysis by inactivating enzymes, namely the beta-lactamases. While the number of characterised beta-lactamases may exceed 100, only a few are a problem in the treatment of community-acquired infections (TEM-1, TEM-2, SHV-1, BRO-1). Chromosomally mediated and extended-spectrum beta-lactamases are usually dominant in nosocomial pathogens where oral antibiotic therapy is seldom used. Therefore, the threat posed by beta-lactamases must be considered in general practice. Several effective strategies have been implemented in order to overcome beta-lactamase-mediated resistance, e.g. use of non-beta-lactam drugs or beta-lactamase inhibitors. Another option has been the development of new beta-lactam compounds that possess a high intrinsic stability against the hydrolytic action of common beta-lactamases. Among these compounds, the oral third generation cephalosporins represent an important breakthrough. Cefetamet pivoxil, a new oral third generation cephalosporin, is characterised by excellent antimicrobial potency against Enterobacteriaceae, and Moraxella (Branhamella) catarrhalis and Haemophilus influenzae, irrespective of their ability to produce beta-lactamases. The Gram-positive respiratory pathogens, Streptococcus pyogenes and penicillin-susceptible S. pneumoniae, are also satisfactorily covered. The activity of cefetamet has recently been corroborated in a survey conducted in Italy involving 4191 isolates. However, cefetamet shows no activity against enterococci, staphylococci, Listeria, alpha-streptococci, Pseudomonas, Acinetobacter and anaerobes. Given this antibacterial profile, cefetamet pivoxil may provide a useful alternative to other oral antibacterial agents in the empirical therapy of acute community-acquired respiratory and urinary tract infections. From the results of the Italian survey, cefetamet emerged as the only agent among those considered (which included cefuroxime, cefaclor, cefalexin, cefadroxil, ampicillin, amoxicillin/clavulanic acid, ampicillin/sulbactam, doxycycline, erythromycin and clindamycin) that might be selected as the drug of choice in the empirical therapy of outpatient infections.

Administration, Oral↗

Recurrent cytogenetic abnormalities observed in complete remission of acute myeloid leukemia do not necessarily mark preleukemic cells.

We have undertaken the cytogenetic monitoring of 39 adult patients treated for de novo acute myeloid leukemia (AML) by intensive chemotherapy. We describe this monitoring in seven patients in continuous complete clinical and morphologic remission (CR) of AML. Although in CR, these patients exhibit the emergence of cytogenetically abnormal clones. Abnormalities observed include monosomy 7, del(20)(q11), partial trisomy 1q, and 6p12-22 rearrangements. They correspond to well-known chromosomal rearrangements commonly found in myelodysplasia (MDS), and myeloproliferative syndromes (MPS), as well as AML. Present as the sole detected chromosomal change, they preceded by months the onset of overt leukemia or MDS. In some cases, the abnormal clone showed a proliferative advantage (some patients exhibited up to 100% of abnormal bone marrow metaphases in subsequent analyses). AML relapse, when it occurred, was associated with a different chromosomal modification. Altogether the question arises, whether the abnormalities pointed out in our study (monosomy 7, del(20)(q11), partial trisomy for the long arm of chromosome 1 (q21qter), 6p12-22 rearrangements), and seen after chemotherapy, mark preleukemic cells or not, and whether they participate indirectly, or not at all in the leukemic process.

Adult↗

Paraneoplastic Raynaud's phenomenon.

A testicular tumour could be diagnosed by the occurrence of a Raynaud's phenomenon complicated by severe digital arteritis. The arteritis rapidly regressed under prostacyclin therapy. Such vascular manifestations are frequent in testicular carcinoma, but they usually develop after chemotherapy. To our knowledge, this is the first case where they preceded the diagnosis and specific treatment of a tumour of the testis.

Adolescent↗

Lymphoma developing in a patient with rheumatoid arthritis taking methotrexate.

We report one case of non-Hodgkin lymphoma in a patient, with a 30-year history of rheumatoid arthritis, taking low dose methotrexate weekly over a 10-month period. The mild immunosuppression that occurs with methotrexate therapy probably places patients with rheumatoid arthritis at added risk of developing lymphoproliferative diseases, but coincidence cannot be excluded.

Aged↗

Inhibition of Pseudomonas aeruginosa virulence factors by subinhibitory concentrations of azithromycin and other macrolide antibiotics.

The ability of three macrolide antibiotics (erythromycin, clarithromycin and azithromycin) to inhibit the expression of several pathogenicity traits of Pseudomonas aeruginosa at concentrations that do not affect the rate of growth of this microorganism was investigated. Sub-MICs of azithromycin manifested the broadest spectrum of action and strongly suppressed the synthesis of elastase, proteases, lecithinase and DNase. Clarithromycin and erythromycin were far less effective. Gelatinase was reduced almost to the same level by the three antibiotics, while haemolysins and lipase were only marginally affected. Loss of motility was a strain and drug-dependent event, but all the macrolides tested shared the ability to induce this effect. However, only azithromycin totally suppressed synthesis of pyocyanin in all isolates. These results indicate that newer macrolides and especially axithromycin are endowed with a remarkable ability to inhibit in vitro the expression of a number of physiological processes that are considered more essential than replication in the pathogenesis of P. aeruginosa. Since erythromycin sub-MICs have already been shown to exert beneficial effects in clinical practice, our data, pointing to a much higher potency of azithromycin, suggest its use in future studies.

Anti-Bacterial Agents↗

A case study of a recent decline in the dialysis fatality rate.

Geoffrey Berlyne, whom we honor in this Festschrift, has contributed much to the modern understanding of diseases of the kidney, and of the clinical and metabolic disorders that occur in acute and chronic renal failure. The Festschrift highlights the many areas of his contributions. It is important to note that underlying them all is astute clinical observation, incisive analysis and reasoning, a breadth of approach, experimentation that facilitated understanding of the relevant clinical issues, and an unusual clarity of exposition in the literature. As author, editor, and teacher, Geoffrey Berlyne has brought this clarity of approach to a generation in nephrology. The following analysis of clinical data from a working dialysis unit, rendering care to a predominantly underprivileged patient population, is presented in the hope that it throws light on everyday problems in nephrology in a manner similar to that in which Geoffrey has guided the nephrology community.

Case-Control Studies↗

[Erythroderma disclosing transformation of refractory anemia with excess of blasts into lymphoblastic leukemia].

We report a case of erythroderma revealing lymphoblastic leukaemia occurring immediately after myelodysplasia. The patient was an 87-year old man admitted for poor general condition, lymph node enlargement and pruriginous oedematous erythroderma. Laboratory examinations showed tricytopenia, bone marrow invasion by lymphoblasts in a myelodysplastic environment of the refractory anaemia type with excess of blasts, and a cutaneous lymphocytic infiltrate with non-blastic lymph node reaction. Owing to its morphological and immunohistological features, the lymphocytic infiltrate was regarded as non-specific. We could not help comparing this case to the other non-specific cutaneous lesions of refractory anaemia which usually reflect transformation into leukaemia.

Aged↗

Plasmid loss from gram-negative bacteria exposed to subinhibitory concentrations of beta-lactam drugs and azithromycin.

The stability of F'lac, pW101 and pHSG298 in Escherichia coli K12 exposed to subinhibitory concentrations of beta-lactam antibiotics, amikacin and tetracycline was studied. High molecular weight low copy plasmids (F'lac and pW101) were eliminated from bacteria treated with PBP-3 binding molecules, while a low molecular weight high copy extrachromosomal element (pHSG298) was not. None of the carbapenem antibiotics, mecillinam, amikacin or tetracycline promoted high rate plasmid loss from their hosts. Under the same conditions, plasmid-mediated ampicillin-resistance due to beta-lactamase production was also lost from F'lacTn1-carrying bacteria. In contrast, the high copy R6K plasmid was stably inherited in their hosts with the exception of those organisms treated with cefixime. When the same experiments were performed with a Klebsiella pneumoniae strain induced to form filaments by azithromycin at sub-MICs, F'lacTn1 and pW101 loss was detected, while pHSG298 was stably inherited. These results confirm previous observations that plasmid stability is correlated with cell shape and that recovery is more easily achieved when bacteria undergo an unbalanced division resulting in cell filamentation.

Anti-Bacterial Agents↗