Biomedical subjects

P Marone

Publications and source records attributed to P Marone.

At least 37 records · Page 2Linked to original sources

PubMed2000

Granular cell tumors of the colon: report of a case and review of the literature.

Granular cell tumors are uncommon, usually benign tumors that can be located anywhere in the body. They commonly occur in the oral cavity and in subcutaneous tissue. In the gastrointestinal tract, granular cell tumors are uncommon and are quite rare in the colon. To date, 55 patients diagnosed with granular cell tumors of the colon have been reported in the literature, only 15 had multiple tumors. We describe the case of a 38-year-old man with a family history of colon cancer who was diagnosed with multiple colonic granular cell tumors after a screening colonoscopy. This seems to be the first report of this type. However, in our patient, the diagnosis of colonic granular cell tumors was incidental and there is no data that correlates adenomas or colorectal cancer with granular cell tumors of the colon. Finally, since granular cell tumors are usually benign, we suggest a conservative approach to patients with multiple granular cell tumors of the colon by means of endoscopic resection and a strict endoscopic follow-up.

Adult↗

PubMed2000

Role of endoscopic ultrasonography in the staging of rectal cancer: a retrospective study of 63 patients.

We evaluated retrospectively the accuracy of endoscopic ultrasonography (EUS) in the preoperative staging of 63 patients with rectal cancer who were hospitalized and underwent surgery at our institution from January 1994 to December 1997. These patients, 39 men and 24 women with a mean age of 60 years, underwent preoperative EUS, which was performed in all cases using an echo-colonoscope Olympus CF UM 20, with a 7.5 MHz radial scanner. Ten patients did not undergo surgery and, therefore, were excluded from the analysis. EUS showed an overall accuracy of 81% for the T stage (including nontraversable stenotic tumors) and of 70% for the N stage. The accuracy of EUS for the T stage increased from 81 to 90% when we excluded those cases with nontraversable stenotic cancers from the analysis. Five tumors (9.4%) were understaged. while another five cases (9.4%) were overstaged. Finally, EUS was highly accurate (81%) in differentiating T1 from T24 tumors. In conclusion, our data shows that EUS is very accurate in the locoregional staging of rectal cancer and confirms the role of this imaging technique in the preoperative staging of patients with rectal cancer.

Adenocarcinoma↗

PubMed2000

Vancomycin-resistant Enterococcus faecium infection in three children given allogeneic hematopoietic stem cell transplantation: clinical and microbiologic features.

BACKGROUND AND OBJECTIVES: The emergence of vancomycin-resistant enterococci (VRE) as nosocomial pathogens is a major problem in the US; in Europe, VRE nosocomial infections are uncommon and only rarely have been reported in Pediatric or Neonatal Units. The aim of this study is to report on the clinical and microbiological features of VRE infections in 3 children given hematopoietic stem cell transplantation (HSCT). PATIENTS AND METHODS: Five episodes of vancomycin-resistant Enterococcus faecium (VREF) infection were diagnosed in 3 children given an allogeneic HSCT. Molecular methods, such as random amplification of polymorphic DNA (RAPD) fingerprinting and automated ribotyping, were used in order to define the circulation of strains. RESULTS: All the isolates were resistant to all commercially available agents and showed the VanA genotypic profile. All children were successfully treated with the combination of quinupristin/dalfopristin (QD) plus teicoplanin (TEC), although treatment was not sufficient to eradicate the micro-organism promptly from the gastrointestinal tract. All our children are still alive. After the first isolation of VRE, a surveillance protocol was started and we documented that the rate of colonization in children and their mothers was less than 1.5%. The RAPD method demonstrated the possible nosocomial transmission of one strain. INTERPRETATION AND CONCLUSIONS: Our experience demonstrates that VRE infection is a life-threatening complication in children given HSCT. Prompt diagnosis of this infection and its treatment with the combination of QD and TEC can successfully manage this severe infection in profoundly immunocompromised patients.

Anti-Bacterial Agents↗

PubMed1999

Mucosal expression of carcinoembryonic antigen and carbohydrate antigen 19-9 in patients with gastritis and gastric cancer.

Sixty-eight patients (45 males, 23 females) were studied in order to assess the usefulness of mucosal tissue concentrations of both carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) in detecting patients at high risk for gastric cancer. CEA and CA19-9 were assayed on cytosol obtained from multiple endoscopic biopsies of 41 patients with chronic superficial gastritis, 18 with chronic atrophic gastritis, and 9 with gastric cancer. Mucosal tissue concentrations of both CEA and CA19-9 increased from chronic superficial gastritis to chronic atrophic gastritis and to gastric cancer (p = 0.005 and p = 0.002, respectively). Mucosal CEA levels in patients with intestinal metaplasia (IM) were significantly higher than in nonmetaplastic mucosa (p = 0.04). Epithelial dysplasia was associated with higher, though not significant, tissue concentrations of both CEA and CA19-9 when compared with IM. Finally, a correlation between serum levels and tissue concentrations was observed only for CA19-9 (Pearson's correlation coefficient = 0.7). In conclusion, these data indicate that gastric mucosa of patients with chronic atrophic gastritis and intestinal metaplasia express high levels of both CA19-9 and CEA.

Adult↗

PubMed1999

Antibiotic-impregnated fibrin glue in ocular surgery: in vitro antibacterial activity.

A strategy to reduce postoperative ocular infections might consist in maintaining a high antibiotic concentration in the eye by using a topical slow-release drug formulation. Fibrin glue is widely used in ocular surgery. Vancomycin, teicoplanin, cephalothin and gentamicin were added to a 500 IU/ml thrombin solution, their concentrations in 1 g fibrin glue being 500 microg for vancomycin and 400 microg for the other drugs. The in vitro antibacterial activity of antibiotic-impregnated fibrin glue was evaluated against a recent clinical isolate of Staphylococcus epidermidis. Moreover the antibiotic elution from fibrin discs in saline was assayed for up to 96 h. Fibrin glue properties were maintained when thrombin was reconstituted with a CaCl2 solution additioned with the antibiotics tested. All antibiotic fibrin mixtures exhibited good antistaphylococcal activity immediately after the preparation. A prolonged inhibition (4 days) of S. epidermidis growth was observed with teicoplanin discs. Gentamicin and teicoplanin levels were higher than those of the other antibiotics. The results suggest that the fibrin glycopeptide and/or gentamicin mixtures can be used, both prophylactically and therapeutically, in ocular surgery.

Cephalothin↗

PubMed1999

Typing of methicillin-resistant Staphylococcus aureus (MRSA) strains from an intensive care unit by random amplified polymorphic DNA (RAPD).

The identification and control of methicillin-resistant Staphylococcus aureus (MRSA) is of primary concern in intensive care units (ICUs) worldwide. The introduction and circulation of particular strains is best studied by genomic procedures and random amplified polymorphic DNA (RAPD) is well suited for this task. In this study 14 isolates of MRSA, obtained over an 8 month period from the blood cultures of 12 patients in an ICU at our hospital, were typed by RAPD method using seven primers. Three separate groups were distinguished and clustering of certain types in time and space was noted. These results suggest that although different strains of MRSA were involved in this outbreak, cross-infection with individual types occurred. RAPD fingerprinting is a relatively simple method that allows epidemiologic investigation of MRSA outbreaks in hospital infection.

Bacterial Typing Techniques↗

PubMed1998

Population pharmacokinetics of rifabutin in human immunodeficiency virus-infected patients.

Rifabutin pharmacokinetics were studied by the population approach (NONMEM) with 40 human immunodeficiency virus-infected patients receiving rifabutin at different doses for prophylaxis or therapy of mycobacterial infections. A two-compartment open model with first-order absorption was used as the structural pharmacokinetic model. Parameter estimates were the absorption rate constant (0. 201/h), clearance/bioavailability (CL/F; 60.9 liters/h), volume of the central compartment/bioavailability (231 liters), intercompartmental clearance (60.3 liters/h), and volume of the peripheral compartment/bioavailability (Vp/F; 1,050 liters). The distribution and elimination half-lives were 1.24 and 25.4 h, respectively. The covariates tested for influence on CL/F and Vp/F were sex, age, weight, height, body surface area, tobacco smoking, drug addiction, alanine aminotransferase levels, creatinine clearance, total protein, bilirubin, numbers of CD4(+) cells, presence of diarrhea, cachexia index, rifabutin use (prophylaxis versus therapy), rifabutin dose, study site, and the concomitant administration of clarithromycin, fluconazole, phenobarbital, ciprofloxacin, azithromycin, or benzodiazepines. The only statistically significant effects on rifabutin pharmacokinetic parameters were a 27% decrease in Vp/F due to the concomitant administration of azithromycin and a 39% increase in Vp/F due to tobacco smoking. Such effects may be considered clinically unimportant. Our results confirm the lack of a correlation of rifabutin pharmacokinetic parameters with parameters of disease progression and gastrointestinal function. Also, the lack of a correlation with covariates which were previously found to be significant, such as concomitant fluconazole and clarithromycin use, may suggest that the effect of such covariates may be less important in the real clinical setting, in which several concomitant factors may influence pharmacokinetic parameters, with an overall effect of no apparent correlation.

Adult↗

PubMed1998

Multicenter comparison of ESP Culture System II with BACTEC 460TB and with Lowenstein-Jensen medium for recovery of mycobacteria from different clinical specimens, including blood.

The recently developed ESP Culture System II (AccuMed, Chicago, Ill.) was compared with radiometric BACTEC 460TB (Becton Dickinson, Towson, Md.) and with Lowenstein-Jensen medium for recovery of mycobacteria from over 2,500 clinical specimens both of respiratory and nonrespiratory origin, including blood. The majority of the 219 mycobacterial isolates (129) belonged to the Mycobacterium tuberculosis complex, followed by 37 isolates of the Mycobacterium avium complex (MAC) and 53 isolates of eight other mycobacterial species. Rates of recovery obtained with BACTEC, ESP, and Lowenstein-Jensen medium were 89, 79, and 64%, respectively, with such differences being statistically significant. Different media and systems appeared to behave differently when the more frequently detected organisms were considered: M. tuberculosis complex isolates grew better with BACTEC, and MAC isolates grew better with ESP. An analysis of the combinations of Lowenstein-Jensen medium with BACTEC and with ESP did not reveal significant differences in recovery rates. With regard to the times needed for the detection of positive cultures, they were significantly longer on Lowenstein-Jensen medium (average, 28 days) than with the remaining two systems, between which there was no difference (average, 18 days). We conclude, therefore, that the ESP system, when used in combination with a solid medium, performs as well as the thoroughly validated radiometric BACTEC system and offers the advantages of full automation and absence of radioisotopes.

Bacteriological Techniques↗

PubMed1998

Comparative in vitro activity of silver sulfadiazine, alone and in combination with cerium nitrate, against staphylococci and gram-negative bacteria.

Silver sulfadiazine (SSD), a topical antimicrobial agent, has been widely used for the prophylaxis and treatment of burn infections during the past 30 years. We determined the antimicrobial activity of SSD, alone and in combination with cerium nitrate (CN), gentamicin and amikacin against 130 recent clinical isolates, including multiresistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) or Pseudomonas aeruginosa. The overall activity of SSD was good against all the tested strains and it was particularly high against MRSA (MIC90 100 microg/ml). CN showed no inhibitory effect, even up to 800 microg/ml, on bacterial strains tested. The combination of SSD and CN was as active as SSD alone. In conclusion, SSD has a broad spectrum of activity at concentrations lower than those commonly used in clinical preparations. All strains were inhibited by less then one-fiftieth of the SSD "in use" concentration (10 mg/ml). Our data confirm the efficacy of this topical agent in the prevention and treatment of infections in burns or other surgical wounds and suggest its possible use in clearing staphylococcal carriage as an alternative to mupirocin.

Anti-Infective Agents, Local↗

PubMed1998

Rapid identification of Mycobacterium tuberculosis and Mycobacterium avium by polymerase chain reaction and restriction enzyme analysis within sigma factor regions.

A single Polymerase Chain Reaction (PCR) within the rpoV gene was developed to rapidly distinguish mycobacteria isolated from clinical specimens. The species identifications of Mycobacterium avium complex (MAC) and Mycobacterium tuberculosis were congruent with standard typing techniques. The analysis was targeted toward the identification of species-specific markers for the clinically relevant M. tuberculosis and M. avium. In addition, HaeIII digestion of the amplification products yielded isolates-specific bands.

DNA Primers↗

PubMed1997

Prevalence of and risk factors for fungal vaginitis caused by non-albicans species.

OBJECTIVE: Our purpose was to evaluate the prevalence of symptomatic yeast vaginitis caused by non-albicans species among patients attending a vaginitis clinic over an 8-year period. STUDY DESIGN: A retrospective study of 1263 patients with symptomatic yeast vaginitis confirmed by culture techniques was performed. RESULTS: The prevalence of symptomatic fungal vaginitis caused by non-albicans species increased from 9.9% (10/101) in 1988 to 17.2% (36/209) in 1995 (chi 2 for trend = 9.33, p = 0.002). Non-albicans species were found more frequently in known human immunodeficiency virus-seropositive patients (23/102 vs 143/1161, odds ratio 2.07, 95% confidence interval 1.2 to 3.46) than in seronegative subjects or subjects of unknown status for the virus. Recurrent vaginal candidiasis was an additional risk factor for vaginitis caused by non-albicans species (odds ratio 2.47, 95% confidence interval 1.72 to 3.52). The increase in non-albicans isolates during the study period was confirmed in stratified analysis and in the subgroup of self-referred patients with no history of either human immunodeficiency virus infection or recurrent vaginal candidiasis. CONCLUSION: The prevalence of fungal vaginitis caused by non-albicans species has increased sharply in the setting of a vaginitis clinic. The characteristics of risk factors suggest that fungal cultures should be done routinely in human immunodeficiency virus-seropositive subjects with suspected vaginal candidiasis and in patients with recurrent vaginal infection.

Adult↗

PubMed1997

Rapid drug susceptibility of Mycobacterium avium complex using a fluorescence quenching method.

Mycobacteria Growth Indicator Tube (MGIT) is a recently introduced rapid growth detection method which uses an oxygen quenched fluorescent indicator. The present study evaluated the ability of this new method to determine the drug susceptibility of Mycobacterium avium complex (MAC). Thirty strains recovered from patients with AIDS were tested for susceptibility to clarithromycin, rifabutin, ciprofloxacin, azithromycin and amikacin using MGIT. Results were compared to susceptibilities determined by the agar dilution method. The results obtained showed a 100% correlation between MGIT and the agar dilution method for rifabutin and clarithromycin. There was a 100% correlation between the two methods for azithromycin against 27 strains. MGIT was well correlated with the agar dilution method for detecting resistance to clarithromycin, rifabutin and azithromycin in 4 days, but the correlation was poor when susceptibilities to ciprofloxacin and amikacin were determined. This rapid method is non-radiometric, noninvasive and does not require any special instruments.

Acquired Immunodeficiency Syndrome↗

PubMed1996

Comparison of an improved RAPD fingerprinting with different typing methods for discriminating clinical isolates of Staphylococcus spp.

Different epidemiological markers were used to characterize 2 Staphylococcus epidermidis and 8 Staphylococcus aureus strains isolated from patients with severe infections. We compared random amplified polymorphic DNA (RAPD) fingerprints, biotypes, antibiotic assays, plasmid profiles and chromosomal DNA restriction endonuclease analysis (REA). Data analysis based on numerical taxonomy methods indicates that RAPD and REA give similar results allowing a good discrimination of the two species and of each isolate. The RAPD method is easier and faster than REA, but the reproducibility of RAPD fingerprints obtained in independent experiments can be problematic. We have found simple technical devices to improve the reproducibility of the RAPD procedure which is therefore a very useful tool in epidemiology for identification and characterization of Staphylococcus spp.

DNA, Bacterial↗

PubMed1996

The katE gene, which encodes the catalase HPII of Mycobacterium avium.

Disseminated Mycobacterium avium-Mycobacterium intracellulare disease is a prevalent opportunistic infection in patients with acquired immune deficiency syndrome (AIDS). These pathogens are generally resistant to isoniazid (INH), a powerful antituberculosis drug. It is now generally accepted that the INH susceptibility of Mycobacterium tuberculosis results from the transformation of the drug into a toxic derivative, as a result of the action of the enzyme catalase-peroxidase (HPI), encoded by the katG gene. It has been speculated that the presence of a second catalase (HPII) in some mycobacterial species, but lacking in M. tuberculosis, may impair the action of INH. In this report, the nucleotide sequence of the M. avium katE gene, encoding catalase HPII, is described. This enzyme shows strong similarity to Escherichia coli catalase HPII and eukaryotic catalases. All amino acids previously postulated as participating directly in catalysis by liver catalase and most of the amino acids binding the prosthetic group are conserved in M. avium catalase HPII. The enzyme is expressed in E. coli and is inhibited by 3-amino-1,2,4-triazole (AT). Furthermore, Southern blot hybridizations and polymerase chain reaction experiments demonstrate the distribution of katE gene in several mycobacterial species. To evaluate the potentially antagonistic effect of HPII catalase on INH susceptibility, the katE gene was transformed into M. tuberculosis H37Rv and the minimum inhibitory concentration (MIC) for INH was determined. Despite strong expression of the katE gene, no change in MIC was observed, thus ruling out a possible contribution of this enzyme to the natural resistance of M. avium to the drug. The availability of the gene probe, encoding the second mycobacterial catalase HPII, should open the way for the development of new drugs and diagnostic tests to combat drug-resistant pathogen strains.

Amino Acid Sequence↗

PubMed1996

Effects of recombinant murine (rm) interleukin-12 and rm interferon-gamma in mice infected with Bordetella pertussis.

The recombinant cytokines interferon (IFN)-gamma and interleukin (IL)-12 stimulate several macrophage-mediated functions that are important in host defense. An experimental pertussis model showed that intraperitoneal (i.p.) administration of 10,000 U of recombinant murine (rm) IFN-gamma to mice at the time of Bordetella pertussis infection caused a marked and significant reduction in the number of colony-forming units of bacteria in the lungs. Administration i.p. of 1 microgram of rmIL-12 or 1 microgram of rmIL-12 at the time of and for 5 consecutive days after B. pertussis challenge also induced a significant reduction in the number. However, i.p. administration of 1 microgram of rmIL-12 with 10,000 U of IFN-gamma at the time of B. pertussis challenge did not provide protection. These findings indicate that exogenous administration of rmIL-12 and rmIFN-gamma enhances resistance of mice to B. pertussis infection.

Animals↗

PubMed1995

Ocular infections: antibiotics and bacterial adhesion on biomaterials used in ocular surgery.

The in vitro antibacterial activity of ofloxacin, sagamycin and other antibiotics was evaluated against 85 bacterial isolates [coagulase-negative staphylococci (CNS), n = 37, Staphylococcus aureus, n = 28, and Pseudomonas aeruginosa, n = 20] obtained from patients with ocular infections. The antistaphylococcal activity of ofloxacin was quite elevated with a 90% minimal inhibitory concentration (MIC90) of 1.56 mg/l against CNS and S. aureus. Rokitamycin and erythromycin showed a good activity against methicillin-sensitive staphylococci, but were less active than ofloxacin and sagamycin against methicillin-resistant strains (MIC90 > 100 mg/l). Sagamycin was highly effective against staphylococci (MIC90 0.78 mg/l) and appeared to be the most active compound against P. aeruginosa (MIC90 6.25 mg/l), followed by ofloxacin, tobramycin and gentamicin. In a successive part of the study, the adhesive properties of slime-producing staphylococci were tested on biomaterials used in ocular surgery. Intraocular lenses, Silastic sheetings, circling bands and grooved strips showed a high affinity for slime-producing strains, while round silicone sponges were not covered by bacterial biofilm. In the last part of our study, we demonstrated how subMIC levels of ofloxacin increased the adhesion of slime-producing staphylococci. Our data confirmed the excellent activity of ofloxacin and sagamycin against ocular pathogens and the key role of adhesion in promoting colonization and infections of biomaterials.

Anti-Bacterial Agents↗

PubMed1995

[Not Available].

Rhodococcus equi is a facultative intracellular, obligate aerobe, partially acid fast, gram-positive pathogen that causes cavitary pneumonia in animals and immunocompromised humans. We describe 8 cases of R. equi pneumonia in patients with advanced HIV infection (CD4 counts less than 100/mm3), 7 males and 1 female (mean age 30.8 years), observed between 1991 and 1994. A history of exposure to farm animals was found in 4 patients. The most common presenting symptoms were fever, malaise, dyspnea, cough and hemoptysis, chest pain and weight loss. Chest x-rays showed tipical focal area of consolidation throughout the lung (3 upper, 3 lower and 2 middle fields) associated with cavitation in 4 cases. The definitive diagnosis in our hands was delayed only in the first case in which conflicting data resulted from blood culture (Bacillus sp. isolation) and sputum examen (acid-fast bacterium in the Ziehl-Neelsen stain). Final microbiological diagnosis depended on blood cultures (n=5), bronchoalveolar lavage (n=1), sputum (n=1), lung biopsy (n=1). All the patients were treated with prolonged courses of antibiotic therapy (259 days, range 120-340 in 6 dead patients; more than one year and two months respectively in two patients alive). According to microbial susceptibility TMP/SMX, vancomycin, imipenem, rifampin, aminoglycosides, macrolides and quinolons were more frequently used. Resistant R. equi mutants were selected during therapy with TMP/SMX (n=2), rifampin (n=1) and erythromycin (n=1). Five patient underwent pulmonary lobectomy after exclusion of metastatic bacterial lesions. Only 2 patients are alive, one after 365 days of antibiotic therapy and upper lung lobectomy, one after 60 days of antibiotic therapy. Optimal antimicrobial therapy and the role of surgery remain, in our experience, uncertain.

English Abstract↗

PubMed1994

Sternal osteomyelitis due to Aspergillus fumigatus after cardiac surgery.

Sternal osteomyelitis due to Aspergillus fumigatus after cardiac surgery occurred in two nonimmunosuppressed patients. The clinical features of the infection were markedly different in the two cases. In the first patient, sepsis showed a late and insidious onset followed by slow progression. In the second case, fungi were isolated from wound swabs within a few days of surgery and the clinical picture showed acute onset and rapid progression. Only a few cases of sternal osteomyelitis due to Aspergillus have been described previously after cardiac surgery. Aspergillus infection should be considered in the differential diagnosis of mediastinitis after cardiac surgery, especially in a clinical setting of otherwise unexplained sepsis or nonhealing wound despite apparently adequate treatment.

Aged↗