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Biomedical subjects

L Romano

Publications and source records attributed to L Romano.

At least 37 records · Page 2Linked to original sources

Nonfunctioning endocrine tumors of the pancreas: possibilities of spiral CT characterization.

The aim of this study was to assess the ability of spiral CT to adequately characterize the nonfunctioning endocrine tumors (NFETs) of the pancreas, distinguishing this lesion from the other pancreatic tumors. The spiral CT examinations of 21 cases of histologically proven NFETs, along with those of 29 cases of other pancreatic tumors and tumor-like lesions, were retrospectively reviewed in a blinded fashion by two radiologists, in order to correctly classify the lesions, highlighting the typical signs reported in the literature. Discordant cases were further analyzed in the presence of a third radiologist. The final diagnosis was acquired by means of a majority or overall consensus. The histopathologic examination was considered the gold standard. The sensitivity, specificity, and positive and negative predictive values of CT were calculated. After the consensus evaluation, the correct diagnosis was reached in 72% of cases, with 10% of nonspecific diagnoses of solid pancreatic tumor and 18% of wrong diagnoses. The sensitivity and specificity of spiral CT in identifying NFETs were 66.6 and 82.7%, respectively. The positive and negative predictive values were 73.7 and 77.4%, respectively. In up to 70% of cases the NFET demonstrates a typical aspect of a mass hyperdense in the arterial contrastographic phase eventually associated with hyperdense hepatic metastases in more than half of the patients. This finding does allow the diagnosis of NFET but without certainty indeed, since other tumors can show a similar densitometric behavior and among them particularly the ductal adenocarcinoma. On the other hand, both the solid, hypovascularized NFETs, and the cystic form, cannot be differentiated from the other solid and cystic tumors of the pancreas.

Adenoma, Islet Cell↗

In vitro susceptibility of Vibrio spp. isolated from the environment.

Bacteria of the genus Vibrio include harmless aquatic strains as well as strains capable of causing epidemics of cholera and human intestinal diseases. Some of these species may show resistance to different antibiotics including cefotaxime, tetracycline and chloramphenicol. The susceptibility to different antibiotics was tested using 40 Vibrio alginolyticus, eight V. parahaemolyticus and six V. vulnificus strains isolated in the coastal waters of Northern Sardinia (Italy). The frequency of resistance to beta-lactams was unexpectedly high. More than 80% of Vibrio isolates were resistant to ampicillin and 2.5% of V. alginolyticus were resistant to ceftazidime and cefotetan. Forty percent of V. alginolyticus and three V. vulnificus isolates gave a positive nitrocefin test. PCR was also performed using selected primers chosen for having common sequences of bla(TEM) and bla(SHV) genes.

Anti-Bacterial Agents↗

Molecular basis of rifampin and isoniazid resistance in Mycobacterium bovis strains isolated in Sardinia, Italy.

Fourteen of 22 (68%) Mycobacterium bovis strains isolated from cattle in Sardinia were found to be resistant to rifampin and isoniazid. Analysis of the rpoB and the katG, oxyR-ahpC, and inhA gene regions of these strains was performed in order to investigate the molecular basis of rifampin and isoniazid resistance, respectively. The most frequent mutation, encountered in 6 of 10 strains (60%), was in the rpoB gene; it occurred, at codon position 521 and resulted in leucine changed to proline. This suggests that codon 521 may be important for the development of rifampin resistance in M. bovis. Resistance to isoniazid is associated in Mycobacterium tuberculosis with a variety of mutations affecting one or more genes. Our results confirm the difficulty of interpreting the sequence variations observed in clinical strains of M. bovis. M. bovis strains isolated from the same geographic area showed similar mutations within the genes responsible for rifampin and isoniazid resistance. Our results represent the first study to elucidate the molecular genetic basis of drug resistance in M. bovis isolated from cattle.

Animals↗

[Role of computerized tomography in the diagnosis of peritoneo-intestinal lesions resulting from closed trauma. Experience at 2 emergency departments].

INTRODUCTION: Small and large bowel mesenteric injuries from blunt abdominal trauma are rare and often difficult to diagnose. Computed Tomography used in cases of blunt abdominal trauma has been found sensitive in detection of bowel and mesenteric injuries and discrimination of operable from nonoperable candidates. PURPOSE: A retrospective study of the CT examination of 24 patients, with surgically confirmed bowel and mesenteric injuries, was performed. Our goal was to evaluate the various CT signs of blunt bowel and mesenteric injury and the related frequency. MATERIAL AND METHODS: Our series includes 24 patients, 16 of them (first group) were investigated with CT at Cardarelli Hospital, Naples, while the remaining 8 (second group) at University of Bari. Patients of the first group, 11 men and 5 women, age ranging from 18 to 77 years, were submitted to a conventional abdominal CT performed after i.v. administration of contrast media. Patients of the second group, 7 men and 1 woman, age ranging from 4 to 81 years, were submitted to helical CT performed with the following parameters: 10 mm slice thickness, 5-mm contiguous intervals from the level of the diaphragm to the pubic bone, pitch 1.5. Helical CT was performed in all cases before and after i.v. administration of contrast material injected at a rate of 3.5 ml/sec. A scanning delay of 40 seconds after the beginning of contrast injection was routinely used. In all patients the following CT signs were retrospectively searched on: peritoneal or retroperitoneal fluid, mesenteric hematoma, hazy streaky changes in mesenteric fat, high-density clot (sentinel clot) adjacent to the involved bowel, pneumoperitoneum, retropneumoperitoneum, extravasation of intravenous contrast material, bowel wall thickening. RESULTS: In the first group the following CT signs were observed: mesenteric hematoma (87.5%), hazy streaky changes in mesenteric fat (56.25%), peritoneal or retroperitoneal fluid (37.5%), sentinel clot (25%), bowel wall thickening (18.75%), extravasation of intravenous contrast material (12.5%). In the second group the following CT signs were observed: peritoneal or retroperitoneal fluid (87.5%), bowel wall thickening (50%), mesenteric hematoma (37.5%), sentinel clot (25%), pneumoperitoneum (12.5%), retropneumoperitoneum (12.5%), hazy streaky changes in mesenteric fat (12.5%). DISCUSSION AND CONCLUSIONS: Bowel and mesenteric injuries from blunt trauma are infrequent and difficult to diagnose clinically, as the physical and laboratory findings may be subtle and are often overshadowed by other injuries in patients with multisystem trauma. CT represents a proven modality in the evaluation of bowel and mesenteric injuries: careful inspection and technique are required to detect often subtle findings. In our series of 24 patients with surgically confirmed bowel and mesenteric injuries, the presence of mesenteric hematoma and of peritoneal or retroperitoneal fluid were the more frequent CT signs observed. Radiologists may play a crucial role in the timely diagnosis of these injuries, allowing prompt and appropriate management of these patients.

Abdominal Injuries↗

[Effects of metformin on insulin resistance and on ovarian steroidogenesis in women with polycystic ovary syndrome].

BACKGROUND: Polycystic ovary syndrome is considered the most frequent endocrine abnormality during the fertile age. Hyperinsuli-nemia, typical of this syndrome, alters the functionality of the cytochrome P450 c 17 alfa and this causes an exaggerated secretion of male hormones produced by the female gonad. Objective of this study was to verify if the reduction of the circulating insulin levels, obtained through therapy with metformin, caused the reduction of LH levels, LH:FSH ratio, of testosterone and androstenedione levels, but also of cholesterolemia, triglyceridemia, BMI, and naturally of insulinemia, glycemia, as well as an increase in HDLC (high density lipoprotein cholesterol). METHODS: The presence of insulin-resistance and hyperinsulinemia, in 15 women aged between 20 and 30 with BMI >26 kg/m2, has been verified with test loaded with glucose; 500 mg of metformin have been given to these women three times a day before meals for 12 weeks. LH and FSH levels, LH:FSH ratio testosterone, androstenedione, progesterone, estradiol levels, cholesterolemia, trygliceridemia, HDLC and BMI have been considered in each patient before and after therapy. RESULTS: A statistically significant modification of all measured parameters was observed but the most important data is the reduction of the androgens. CONCLUSIONS: The reduction of insulinemia seems to be actually associated with a reduction of circulating androgens in women with polycystic ovary syndrome. As well as the reproductive function, this insulin-sensitizing agent has the further < > advantage of a possible favourable effect also on the complications of the polycystic ovary syndrome specifically connected with: glucose-intolerance, dislipidemia, arteriosclerosis and hypertension. To consider the effects on the complications of the syndrome it would be necessary to give the drug for a period longer than 12 weeks.

Adult↗

[Delayed diagnosis of benign paroxysmal vertigo: economic impact].

Some time has passed since the early 1980's when a group of vestibologists with the same singular passion introduced in Italy the concept of Paroxysmal Positional Vertigo (PPV). Since then great advances have been made, but, despite the energy focused on improving and expanding the knowledge on this common disorder, PPV still frequently goes unrecognized. The direct consequence of delayed diagnosis is prolonged patient discomfort and the execution of useless, costly clinical examinations. Today, in most cases, delayed diagnosis is unjustified. Within the modern concept of health care economics, such delay is costly to the health care provider and has obvious psycho-physical repercussions for the patient who has to undergo a fruitless series of examinations and treatments of all types without reaping any benefits. In this light the Authors have performed a study to identify and quantify the relative costs of the most common errors made in the diagnosis of PPV. For a sample population of 100 patients, the clinical-instrumental tests performed before the disorder was correctly diagnosed were gathered and analyzed. Then the costs for the management of PPV patients diagnosed late were compared with those for patients whose diagnosis was reached early on. The results indicate that for each delay in PPV diagnosis the average cost was Euro 317.66 vs. Euro 64.04 for early diagnosis: a difference of Euro 253.06. The Authors underline how in this brief period of time (March-September 2000) the prescription of excessive testing led to a significant waste of money (Euro 10137.01).

Adult↗

Ultrasensitive in-house reverse transcription-competitive PCR for quantitation of HIV-1 RNA in plasma.

An ultrasensitive version of an 'in-house' reverse transcription-competitive polymerase chain reaction assay described previously for quantitation of human immunodeficiency virus type 1 (HIV-1) RNA in plasma was developed. The increase in sensitivity from 400 to 50 HIV-1 RNA copies/ml was achieved by pelleting virus particles from 1.8 ml plasma by centrifugation prior to RNA extraction, modifying competitor DNA structure and amounts, and redesigning primers. Quantitation of HIV-1 RNA in 130 samples tested previously by the standard assay showed that the two procedures yield comparable results (mean absolute difference, 0.26+/-0.20 log) and that the ultrasensitive version detects HIV-1 RNA below the threshold of sensitivity of the standard method. The ultrasensitive 'in-house assay' and the reference QUANTIPLEX HIV-1 RNA 3.0 had the same sensitivity and gave equivalent results (mean absolute difference, 0.19+/-0.11 log), as shown by parallel blinded testing of 47 plasma samples. Titration experiments with reconstructed plasma samples allowed the determination of a dynamic range of 50-500000 HIV-1 RNA copies/ml for the 'in-house' system. The interassay coefficient of variation for samples nominally containing 200, 4000 and 80000 HIV-1 RNA copies/ml were 33.4, 22.9 and 38.2%, respectively. The performance, turnaround time, and cost-effectiveness of this system make it suitable for medium-scale clinical application.

Centrifugation↗

Commercial systems for fluconazole susceptibility testing of yeasts: comparison with the broth microdilution method.

Fluconazole susceptibility was tested in 100 clinical yeast isolates (65 Candida albicans, 13 C. glabrata, 8 C. tropicalis, 7 C. parapsilosis, 3 Saccharomyces cerevisiae, 1 each of C. krusei, C. lusitaniae, Cryptococcus neoformans, Rhodotorula glutinis) and two control strains (Candida krusei ATCC 6258, C. parapsilosis ATCC 22019) using broth microdilution (reference method), disk diffusion, Etest strips, Sensititre YeastOne, Candifast, Integral System Yeasts. Using M27-A breakpoints, isolates were classified as susceptible (81%), susceptible-dose dependent or Resistant with broth dilution. Rates of concordance with the reference method were good for Sensititre YeastOne, Etest and disc-diffusion (81.2%-94.7%) but very low for the Candifast (3.1%) and Integral System (16.6%), which classified most susceptible isolates as resistant. Lack of standardisation (inoculum, medium composition) and non-objective interpretation schemes may be the cause of their poor performance. Sensititre YeastOne, Etest and disc-diffusion are potentially useful for fluconazole antifungal susceptibility testing of yeasts in clinical laboratories.

Antifungal Agents↗

Antiretroviral resistance mutations in human immunodeficiency virus type 1 reverse transcriptase and protease from paired cerebrospinal fluid and plasma samples.

Twenty-four adults infected with human immunodeficiency virus type 1 (HIV-1) with central nervous system symptoms were studied for antiretroviral resistance mutations in HIV-1 RNA obtained from paired cerebrospinal fluid (CSF) and plasma samples. Paired sequences were obtained from 21 and 13 patients for reverse transcriptase (RT) and for protease, respectively. Mutations conferring resistance to the RT inhibitors zidovudine, lamivudine, or nevirapine were detected in 14 patients, including 11 pretreated and 3 drug-naive subjects. The mutation patterns in the 2 compartments were different in most patients. Genotypic resistance to protease inhibitors was detected in both plasma and CSF from 1 patient treated with multiple protease inhibitors. However, accessory protease inhibitor resistance mutations at polymorphic sites were different in plasma and CSF in several patients. Partially independent evolution of viral quasispecies occurs in plasma and CSF, raising the possibility that compartmentalization of drug resistance may affect response to antiretroviral treatment.

Adult↗

Reverse cross blot hybridization assay for rapid detection of PCR-amplified DNA from candida species, Cryptococcus neoformans, and Saccharomyces cerevisiae in clinical samples.

A PCR-based assay was developed to detect and identify medically important yeasts in clinical samples. Using a previously described set of primers (G. Morace et al., J. Clin. Microbiol. 35:667-672, 1997), we amplified a fragment of the ERG11 gene for cytochrome P-450 lanosterol 14alpha-demethylase, a crucial enzyme in the biosynthesis of ergosterol. The PCR product was analyzed in a reverse cross blot hybridization assay with species-specific probes directed to a target region of the ERG11 gene of Candida albicans (pCal), C. guilliermondii (pGui), C. (Torulopsis) glabrata (pGla), C. kefyr (pKef), C. krusei (pKru), C. parapsilosis (pPar), C. tropicalis (pTro), the newly described species C. dubliniensis (pDub), Saccharomyces cerevisiae (pSce), and Cryptococcus neoformans (pCry). The PCR-reverse cross blot hybridization assay correctly identified multiple isolates of each species tested. No cross-hybridization was detected with any other fungal, bacteria, or human DNAs tested. The method was tested against conventional identification on 140 different clinical samples, including blood and cerebrospinal fluid, from patients with suspected fungal infections. The results agreed with those of culture and phenotyping for all but six specimens (two of which grew yeasts not included in the PCR panel of probes and four in which PCR positivity-culture negativity was justified by clinical findings). Species identification time was reduced from a mean of 4 days with conventional identification to 7 h with the molecular method. The PCR-reverse cross blot hybridization assay is a rapid method for the direct detection and identification of yeasts in clinical samples.

Candida↗

Modification of transepithelial ion transport in human cultured bronchial epithelial cells by interferon-gamma.

Human bronchial epithelial cells were treated in vitro with interferon-gamma or tumor necrosis factor-alpha to assess their effect on transepithelial ion transport. Short-circuit current measurements revealed that Na(+) absorption was markedly inhibited by interferon-gamma (10-1,000 U/ml). The cystic fibrosis transmembrane conductance regulator was also downregulated by interferon-gamma as evident at the protein level and by the decrease in the cAMP-dependent current. On the other hand, interferon-gamma caused an increase of the current elicited by apical UTP application, which is due to the activity of Ca(2+)-dependent Cl(-) channels. Tumor necrosis factor-alpha caused few changes in ion transport. Transepithelial fluid transport was measured in normal and cystic fibrosis cells. At rest, both types of cells showed an amiloride-sensitive fluid absorption that was inhibited by interferon-gamma but not by tumor necrosis factor-alpha. Our results show that interferon-gamma alters the transepithelial ion transport of cultured bronchial cells. This effect may change the ion composition and/or volume of periciliary fluid.

Biological Transport↗

Evidence of lymphocyte alveolitis by bronchoalveolar lavage in thalassemic patients with pulmonary dysfunction.

Pulmonary dysfunction represents one of the least studied complications in thalassemic patients. Probably, it is due to the absence of pulmonary symptoms. There are few works in the literature, and contradictory results have been published. The aim of this study was to define the spirometric pattern and the possible causes of lung impairment by testing bronchoalveolar lavage (BAL) with pathological pulmonary function tests (PFTs). Furthermore, diffusion capacity tests for carbon monoxide corrected for hemoglobin value (Dco*) were performed. We studied 48 thalassemic patients (27 F and 21 M), with an age range from 8 to 23 years, divided into two groups on the basis of PFTs results. Thus, group A was formed by 16 patients with restrictive spirometric patterns of whom 14 had also reduced Dco* values and group B consisted of 32 patients with normal PFTs and Dco* values. Patients of group A underwent chest high-resolution computing tomography (CHRCT) and BAL whose fluid was analyzed by microbiologic and cytological assays. A pathological CHRCT picture was present in 8 patients. Nine out of 16 patients who accepted to undergo BAL had a chronological age greater than 17 years with a mean bone age of 13.9 years. BAL results showed lymphocyte alveolitis in 6 patients and a normal cytogram in 3, while alveolar iron-laden macrophages were present in 4 out of 6 patients with alveolitis and 2 out of 3 patients with normal cytogram. Moreover, all examined BAL fluids showed a normal CD4/CD8 ratio, while only 2 patients showed an altered serum CD4/CD8 ratio. We demonstrated the presence of (1) lung-restrictive syndrome in 16 of the oldest thalassemic patients; (2) lymphocyte alveolitis in 6 patients, and (3) a picture of interstitial fibrosis by CHRCT in 8 of them. All these data are suggestive of a diagnosis of interstitial lung disease secondary to thalassemia. BAL helped to identify the presence of alveolar iron-laden macrophages that represented a local defense mechanism against free iron. This latter finding therefore might be the primary cause of the lung impairment promoting an oxidative damage. Further studies are needed to investigate this hypothesis and therapeutical potentials.

Adolescent↗

Analysis of the HIV-1 nef gene in five intravenous drug users with long-term nonprogressive HIV-1 infection in Italy.

Great variability in the course of human immunodeficiency virus type 1 (HIV-1) infection results from a complex interplay between host and virus factors. Some of the patients with prolonged nonprogressive infection have been reported to harbor virus variants with gross deletions in the accessory nef gene that has been implicated in in vivo pathogenicity in simian and mouse models. To investigate the role of nef-deleted HIV-1 in long-term nonprogressor (LTNP) drug addicts in Italy the nef sequence from proviral DNA was analyzed from five LTNPs and five rapid progressor controls. Only small (2-12 amino acids) in-frame deletions and insertions were detected in the N-terminal polymorphic and variable regions obtained from three LTNPs and one rapid progressor. There was no evidence of premature termination of the Nef protein and all of the identified functional motifs were well conserved in both groups. Phylogenetic analysis showed interdigitation of nef sequences obtained from LTNPs and rapid progressors. The nef sequence of one LTNP, however, diverged significantly from those of the other patients. Availability of two additional blood DNA samples obtained previously from this subject allowed to detect evolution of nef at 14-17 years of HIV-1 infection, including progressive deletions. Although alterations of nef may be relatively frequent and continue to evolve in LTNPs, this study of a small number of patients does not indicate that gross deletions or loss of functional motifs play a major role in delaying or halting disease progression in infected drug abusers in Italy.

Adolescent↗

[The role of spiral computed tomography in sigmoid diverticulitis and the diagnostic-therapeutic implications].

PURPOSE: Colonic diverticula are saccules made of colonic mucosa and submucosa that herniate from the colonic lumen through the muscular layer of the wall where straight vessels penetrate. Diverticula are localized in the sigmoid colon in 95% of cases. Bacteria pooling in the lumen may cause lumen erosion and eventually perforation. CT is a useful technique in this condition because it can demonstrate intra- and/or extramural inflammation. Aim of this retrospective study was to assess the capabilities of contrast-enhanced helical Computed Tomography (CT) in sigmoid diverticulitis, especially relative to selection of the appropriate treatment. MATERIAL AND METHODS: We retrospectively reviewed the findings of 41 patients referred to our emergency department for diverticulitis. CT scans were performed 65 seconds after i.v. injection of nonionic contrast material (3 mL/s, 120 mL in all) administered by a CT-power injector. The following 7 CT findings were considered at least suggestive of acute diverticulitis: focal wall thickening, intramural abscess, inflammatory changes in the sigmoid mesentery root, pericolic fat inflammation or pericolic abscess formation, fistula, peritonitis. CT results were compared with surgical and physical findings. RESULTS: Based on CT findings, diverticulitis was classified as mild (25 patients) or severe (15 patients). In mild diverticulitis we found: focal sigmoid wall thickening (6 patients), intramural abscess (3 patients), sigmoid mesentery root thickening (5 patients), edema fluid (8 patients) and phlegmon (3 patients). In severe diverticulitis we found: sigmoid mesentery abscess (6 patients), fistula (5 patients) and peritonitis (4 patients). CT findings were questionable in 1 case and thus we could not exclude a perforated carcinoma. CONCLUSION: Contrast-enhanced helical CT is the imaging modality of choice in assessing mild or severe acute diverticulitis because it provides useful information for appropriate treatment planning in the emergency setting. This technique is most useful in questionable cases and in patients with suspected severe diverticulitis where a choice must be made between different treatment options.

Colon, Sigmoid↗

Development and significance of the HIV-1 reverse transcriptase M184V mutation during combination therapy with lamivudine, zidovudine, and protease inhibitors.

To analyze the emergence and role of the lamivudine (3TC)-selected HIV-1 reverse transcriptase (RT) M184V mutation under triple therapy, we performed a retrospective study of 40 nucleoside RT inhibitor-pretreated and 16 drug-naive patients who were switched to combined treatment with zidovudine (ZDV) plus 3TC plus a protease inhibitor (PI). Plasma viral load and pol genotype were analyzed at baseline and after 24 and 48 weeks of combination therapy. Emergence of the M184V RT mutation at week 48 was detected in 3 of 16 (18.7%) initially drug-naive subjects as opposed to 21 of 40 (52.5%) ZDV-pretreated patients. Multivariate logistic analysis detected HIV-1 RNA load at week 24 as the best predictor of subsequent selection of the M184V mutant (p = .0121). Among ZDV-resistant study subjects at week 24 (n = 17), those with mutant RT M184V codon had a more favorable HIV-1 RNA slope than those with wild-type RT 184M codon (p = .0551). This trend was observed, although in a less evident manner, even in pretreated ZDV-sensitive patients. These findings suggest that development of the 3TC-resistance M184V mutation under triple therapy with 3TC, ZDV, and a PI may have unexpected beneficial effects in vivo in addition to those associated with resensitization of ZDV-resistant virus to ZDV.

Anti-HIV Agents↗