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Biomedical subjects

G Caruso

Publications and source records attributed to G Caruso.

At least 37 records · Page 2Linked to original sources
PubMed2003

Genetic diversity of bacterial agents detected in ticks removed from asymptomatic patients in northeastern Italy.

A total of 360 ticks were removed from 353 asymptomatic subjects in Belluno Province, Italy and surrounding areas, from 1998 to 2001. Ticks were identified as Ixodes ricinus (357), Ixodes hexagonus (1), Rhipicephalus sanguineus (1), and Ixodes ventalloi (1). Tick DNA was investigated by PCR and subsequent sequencing of amplified products to identity associated bacterial agents. Primers targeting different genes of Rickettsia (gltA and OmpA), Borrelia (16S rDNA, rpoB), Francisella (16S rDNA), and all genera members of the Anaplasmataceae (16S rDNA), were used. DNA of bacterial agents was identified in 28 Ixodes ricinus specimens (7.8%). Rickettsia helvetica was detected in 7 ticks. Rickettsia sp. IRS4 and Borrelia afzelii was detected in 4 ticks each. B. garinii and B. valaisiana were identified in one tick each. Anaplasma phagocytophilum, the agent of human granulocytic ehrlichiosis, was identified in 1 specimen of I. ricinus. A new Ehrlichia sp. ("Candidatus Ehrlichia walkerii", sp. nov.) was identified in 10 I. ricinus specimens.

Anaplasma phagocytophilum↗
PubMed2003

Common arterial trunk in the fetus: characteristics, associations, and outcome in a multicentre series of 23 cases.

OBJECTIVE: To assess the accuracy of prenatal diagnosis, the incidence of extracardiac and chromosomal anomalies, and the perinatal outcome in a population of fetuses with common arterial trunk (CAT). DESIGN: Observational study of 23 fetuses from three referral centres with a confirmed diagnosis of CAT. All underwent fetal echocardiography, detailed anatomical scanning, and karyotyping. In 19 cases, FISH analysis was done to detect 22q11 microdeletion. The following variables were evaluated: gestational age at diagnosis, anatomical variants of the CAT, presence of extracardiac and chromosomal anomalies, pregnancy, and fetal-neonatal outcome. Necropsy reports and postnatal files were available for confirmation of the prenatal diagnosis in all cases. RESULTS: The prenatal diagnosis proved correct in 23 of 24 cases, the last being pulmonary atresia with ventricular septal defect (PAVSD). A second cardiovascular anomaly was present in eight cases (34.8%); extracardiac anomalies were found in 10 (43.4%). FISH analysis showed 22q11 microdeletion in six of 19 cases (31.6%). Outcomes were as follows: eight terminations of pregnancy (34.8%), two intrauterine deaths (8.7%), five postnatal deaths (before or after surgery) (21.7%); the remaining eight neonates (34.8%) are alive and thriving after surgery (six) or awaiting surgery (two). CONCLUSIONS: CAT can be reliably diagnosed and characterised in prenatal life, although differentiation from PAVSD may be challenging. The association with chromosomal anomalies is consistent (8.7%), but there is a higher risk of 22q11 microdeletion (31.6%), in agreement with postnatal studies. The relatively poor survival rate (34.8%) reflects the high rate of terminations and the unfavourable cardiac anatomy in some cases.

Aorta, Thoracic↗
PubMed2002

Outbreak of African tick-bite fever in six Italian tourists returning from South Africa.

In May 1999, a cluster of cases of African tick-bite fever was detected in six Italian tourists who had returned from South Africa. All of the patients had moderate fever and cutaneous eschars. Regional lymphangitis was observed in three of the patients and skin rash in two. By comparing the number of eschars with the number of detectable bite sites it was suggested that at least two-thirds of the biting vectors were capable of transmitting Rickettsia africae. The clinical course of disease was mild in all cases, and all but one of the patients recovered spontaneously before antibiotic treatment was initiated. The diagnosis of African tick-bite fever was confirmed serologically using both microimmunofluorescence and Western blot tests.

Animals↗
PubMed2002

Heterotrophic bacteria in the northern Adriatic Sea: seasonal changes and ectoenzyme profile.

A seasonal study of the quantitative and qualitative distribution of heterotrophic bacterial community was carried out in the Adriatic Sea between April 1995 and January 1996, in order to evaluate its spatial and temporal variability and metabolic potential in the degradation processes of organic matter. The culturable bacteria (CFU) ranged between 0.1 and 22% of total bacterioplankton with a maximum percentage in surface samples of coastal zones. Their distribution was generally affected by the prevailing hydrological conditions. At the coastal stations about 44-75% of CFU variance could be explained by river runoff. The changes in the composition of heterotrophic bacterial community showed a seasonal succession of main bacterial groups, with a prevalence of Gram negative, non fermenting bacteria in the cold period (April-January) and an increase of Vibrionaccae and pigmented bacteria in summer. The seasonal variations were more important at the stations influenced by rivers than offshore. The bacterial community showed a greater versatility for organic polymers hydrolysis in the offshore station than in the coastal areas. Over 60% of all isolated heterotrophic bacteria expressed peptidase, lipase and phosphatase ectoenzymes activities, in all seasons and showed an increasing trend in warm period (in July October). The alpha- and beta-glucosidase potentials of bacteria were lower (20% on average) and showed different pattern during the year. These results suggest different role of the bacterial community in the decomposition of organic matter in the Adriatic Sea. Since only 20% of bacterial strains expressed glucosidase activity, carbohydrate-rich polymers such as mucilage might accumulate.

Bacteria↗
PubMed2002

Development of an enzyme assay for rapid assessment of Escherichia coli in seawaters.

AIMS: An analytical protocol has been developed and applied for the detection of glucuronidase activity in marine waters as a rapid alternative approach to assess the microbiological quality of seawaters. METHODS AND RESULTS: The fluorogenic substrate 4-methylumbelliferyl-beta-D-glucuronide is cleaved to a fluorescent product, methylumbelliferone, by the enzyme beta-glucuronidase, specific to Escherichia coli and closely related enterobacterial species (Shigella). The results suggest that this test is related to E. coli numbers, as estimated by immunofluorescence, more significantly than to faecal coliform numbers, obtained from culture media. CONCLUSIONS: The determination of the potential rate of glucuronidase activity may be used as a diagnostic tool for the indirect estimation of the presence of E. coli in seawaters. SIGNIFICANCE AND IMPACT OF THE STUDY: The method may be particularly useful in the early warning of seawater pollution, allowing the screening of coastal areas with different contamination levels in reduced time.

Bacteriological Techniques↗
PubMed2002

Prenatal diagnosis of interruption of the aortic arch and its association with deletion of chromosome 22q11.

OBJECTIVES: Differentiation of interruption of the aortic arch (IAA) type A from type B by prenatal echocardiography is possible but difficult. We report nine consecutive cases of the prenatal detection of IAA and evaluate the feasibility of making a correct prenatal diagnosis with fetal echocardiography. The incidence of 22q11 microdeletion in our series, detected using fluorescent in situ hybridization (FISH) analysis, was determined. METHODS: Echocardiography and FISH for the DiGeorge critical region (22q11) were performed in all cases. The findings were confirmed by autopsy (three cases) or at postnatal surgery (six cases). RESULTS: On fetal echocardiography we identified six type B cases and three type A. FISH detected microdeletions in 22q11 in five of nine fetuses (four type B cases and an unusual association with type A in one case). CONCLUSIONS: Our report confirms the feasibility of making a correct prenatal diagnosis of IAA and its different types, based on echocardiographic examination. Furthermore our data are consistent with previous reports indicating that type A and type B are distinct entities. In more than 50% of fetuses with IAA type B, 22q11 microdeletion and DiGeorge or velo-cardio-facial syndromes may be expected. IAA type A is not commonly associated with 22q11 hemizygosity.

Aorta, Thoracic↗
PubMed2002

Immunofluorescence detection of Escherichia coli in seawater: a comparison of various commercial antisera.

Through a microscopical method, relying on the interaction between fluorescent antibodies and target antigen, it is possible to detect and enumerate Escherichia coli in seawaters. Various commercial monoclonal and polyclonal antisera have been tested in an indirect immunofluorescence (IIF) assay developed for microbiological monitoring of coastal waters. Prior to use, they have been titrated and screened for cross-reactions with a collection of clinical and environmental isolates. A comparison among counts obtained on field samples showed higher performance for microscopical than for plate methods, due to the ability of all antisera to label target cells specifically, regardless of their viability. Because of their different specificities, polyclonal antisera yielded better quantitative results than monoclonal antisera. The study further suggested the usefulness of the immunofluorescence assay as a rapid alternative analytical tool for the specific detection of bacterial pathogens in aquatic environments.

Colony Count, Microbial↗
PubMed2001

Rickettsia africae, a tick-borne pathogen in travelers to sub-Saharan Africa.

BACKGROUND: African tick-bite fever occurs after contact with ticks that carry Rickettsia africae and that parasitize cattle and game. Sporadic reports suggest that this infection has specific clinical and epidemiologic features. METHODS: We studied patients who were tested for a rickettsial disease after returning from a visit to Africa or Guadeloupe. To assess the value of the microimmunofluorescence assay, Western blotting, and cross-adsorption assays, we compared the results of these tests in 39 patients in whom African tick-bite fever had been confirmed by the polymerase-chain reaction assay, cell culture, or both; 50 patients with documented R. conorii infection; and 50 blood donors. These diagnostic criteria were then applied to 376 additional patients who had returned from southern Africa and 2 who had returned from Guadeloupe and whose serum was being tested for rickettsial disease. RESULTS: In the 39 patients with direct evidence of R. africae infection, the combination of microimmunofluorescence assay, Western blotting, and cross-adsorption assays showing antibodies specific for R. africae had a sensitivity of 0.56; however, each test had a positive predictive value and a specificity of 1.0. An additional 80 patients were found to have an R. africae infection on the basis of these serologic criteria. Infections with R. africae were acquired by visitors to 11 African countries and Guadeloupe. The illness was generally mild and was characterized by a rash in 46 percent of the patients; the rash was usually maculopapular or vesicular and rarely purpuric. Ninety-five percent of patients had an inoculation eschar or eschars, and 54 percent of these patients had multiple eschars, a finding that is unusual in patients with rickettsial infection. CONCLUSIONS: In this series, R. africae was the cause of nearly all cases of tick-bite rickettsiosis in patients who became ill after a trip to sub-Saharan Africa.

Adolescent↗
PubMed2001

Small fibers involvement in Friedreich's ataxia.

Although the involvement of large myelinated sensory fibers in Friedreich's ataxia (FA) is well documented, an impairment of unmyelinated fibers has not been described. We demonstrate an involvement of cutaneous unmyelinated sensory and autonomic nerve fibers in FA patients. We performed a morphological and functional study of cutaneous nerve fibers in 14 FA patients and in a population of control subjects. We used immunohistochemical techniques and confocal microscopy applied to punch skin biopsies from thigh, distal leg, and fingertip, and compared the density of epidermal nerve fibers (ENFs) with the results of mechanical pain sensation and thermal and tactile thresholds performed on hand dorsum, thigh, distal leg, and foot dorsum. We observed in our patients a statistically significant loss of ENFs, a reduced innervation of sweat glands, arrector pilorum muscles and arterioles, and an impairment of thermal and tactile thresholds and mechanical pain detection.

Adolescent↗
PubMed2001

A preliminary study of angiogenesis in paediatric glioblastoma multiforme and its correlation with survival.

OBJECTS: There is a distinct challenge in bringing modern insights into glial tumour genesis to bear on improved outcomes for patients. Insights provided by neuroncological, neuroradiological, neuropathological, and neurosurgical investigations may offer significant advantages in the management of paediatric GBM. The goal of this study was to evaluate angiogenesis as a potential indicator of survival in paediatric glioblastoma multiforme (GBM). METHODS: Angiogenesis was evaluated in six cases of paediatric GBM with multiple criteria, including contrast enhancement on preoperative CT scan, histological vascular hyperplasia (VH) and endothelial proliferation (EP) and immunohistochemical tenascin-C (TN-C) expression. We employed a semiquantitative scale, ranging from not detected (zero) to marked (+3), for each investigational parameter. We evaluated the influence of angiogenesis on survival in each case. CONCLUSIONS: In this preliminary study, angiogenesis provided information that correlated with survival, albeit in a limited number of patients. As we gain better understanding of the molecular biology of brain tumours, with the multitude of genetic alterations and growth factors new therapeutic approaches may emerge, which may hold the promise for cure.

Brain Neoplasms↗
PubMed2001

Isolation and characterization of Borrelia burgdorferi sensu lato strains in an area of Italy where Lyme borreliosis is endemic.

Between 1993 and 1998, we isolated Borrelia burgdorferi sensu lato from 55 of the 119 patients with clinically diagnosed Lyme borreliosis who were admitted to "San Martino" Hospital in Belluno, Veneto, an Adriatic region in northeastern Italy where Lyme borreliosis is endemic. Upon hospitalization, all patients presented erythema migrans. Isolates were typed using ribosomal DNA PCR-restriction fragment length polymorphism (RFLP) analysis of the rrfA-rrlB intergenic spacer. Of the 41 isolates typed, 37 belonged to Borrelia afzelii, 2 to Borrelia garinii, and 2 to B. burgdorferi sensu stricto. Pulsed-field gel electrophoresis, performed on 21 strains (13 new isolates and 8 controls), revealed different RFLP patterns within the B. garinii and B. afzelii strains; among the five B. garinii strains and the 12 B. afzelii strains, three or two different RFLP patterns were identified, according to the restriction enzyme used. The protein patterns of the new isolates confirmed their genotypic classification and revealed the level of expression of some immunodominant proteins like OspA and other characteristic Osps. These findings constitute the first report of such a high recovery rate of B. burgdorferi from patients in a very restricted area in Italy; they also indicate the predominance of the genospecies B. afzelii in the study area and the heterogeneity of the circulating strains.

Adult↗
PubMed2001

[Brain perfusion ultrasound in atherosclerotic disease. Work in progress].

AIM: The use of low frequency probes allows to overcome the resistance of the skull and evaluate Willis's circle by B-mode and Trans-Cranial Color-Doppler (TCCD) to obtain morphological and functional information related to brain circulation during pathologic conditions. With the new software available today modern technology allow us to measure the transient scattering produced by the rupture of the contrast medium microbubbles and estimate the presence of the contrast medium both in macro- and microcircle. In this way it is possible to appraise parenchymal perfusion. This study aims to assess the intracranial micro- and macrocircle using TCCD with contrast medium (Levovist) and to compare the results with the patients' clinical signs. MATERIAL AND METHODS: We studied 21 subjects aged 45-73 years (mean 68 years) with atheromatous uncomplicated plaques in the internal carotid artery producing varying degrees of stenosis and 10 healthy controls. The examinations were performed using an ATL HDI 3000 ultrasound machine with a Phased Array 3.25 MHz probe. The mechanic index was calibrated to high values to obtain rupture of the microbubbles under insonation. Intensity/time curves of transient scattering were extrapolated for both the cerebral macrocircle and the parenchymal microcircle in the region of interest. RESULTS: The curves were compared with the clinical presentation of the different classes of patients and the results obtained were consistent in showing a clinical pattern of perfusional deficit in subjects with symptoms of chronic brain ischemia. In particular, it was possible to compare the morphologic data relative to the contrast medium decay curves with the patient's clinical condition, confirming the suspicion of cerebral microcircle pathology. CONCLUSION: Thanks to improvements in the software and to the definition of effective algorithms, contrast-enhanced TCCD will be able to provide information on brain perfusion in a simple, inexpensive and relatively non-invasive manner.

Adult↗
PubMed2001

Relationship between cardiac function and insulin resistance in obese patients.

Both overweight and insulin resistance predispose to atherosclerosis and cardiovascular diseases, independently of other risk factors. We studied the relationship between insulin resistance and heart function and dimension in 39 patients with different degrees of obesity. Twenty-six women and 13 men with body mass index (BMI) ranging 26.1-41 kg/m2 (mean +/- SD = 33.9 +/- 3.8), without diabetes, hypertension and heart, liver or kidney diseases were studied. Patients were subdivided into 2 groups, 25 with overweight or grade I obesity (group A) and 14 with severe (grade II or III) obesity (group B). Insulin sensitivity was evaluated by the Insulin Tolerance Test (ITT), performed after an overnight fast and K(ITT) was calculated. Echocardiographic measurements were also assessed. Between the two groups no significant difference was observed for either K(ITT) (group A, K(ITT) = 5.47 +/- 1.30; group B, K(ITT) = 4.57 +/- 1.53) or the ejection fraction (EF%) (group A, 71.40 +/- 6.63; group B, 69.86 +/- 7.43). No correlation was observed between BMI and both the EF% and other echocardiographic measurements. In patients with mild obesity (group A) a significant negative correlation between EF% and KITT (r = -0.62,p < 0.001) was observed. In mild obesity, therefore, cardiac function changes occur in relation to the level of insulin resistance but these changes are not related to mass and/or volume changes. The cause(s) of this relationship is not clear, but most likely involves metabolic or endocrine factors. The increased EF% in moderately obese patients that are insulin-resistant may provide an initial compensatory mechanism but may also contribute to a late cardiac damage.

Adult↗
PubMed2000

Atypical Friedreich ataxia phenotype associated with a novel missense mutation in the X25 gene.

We describe two sisters with early onset gait ataxia, rapid disease progression, absent or very mild dysarthria and upper limb dysmetria, retained knee jerks in one, slight to moderate peripheral nerve involvement, and diabetes. Molecular analysis showed that they are compound heterozygotes for GAA expansion and a novel exon 5a missense mutation (R165P). This mutation appears to be associated with an atypical but not milder Friedreich ataxia phenotype.

Adult↗
PubMed2000

Monitoring of fracture calluses with color Doppler sonography.

PURPOSE: Fracture callus formation is closely associated with vascular invasion, and the use of color Doppler sonography has been suggested as a means to monitor, earlier than gray-scale sonography, the first stages of the healing process. We report the findings in a series of patients with tibial fractures in whom both gray-scale sonography and color Doppler imaging were employed to monitor new bone formation at the fracture site. METHODS: Twenty patients with tibial fractures treated with external fixator frames were examined sonographically about 10 days after surgery and then about every 25 days until radiographic demonstration of consolidation. RESULTS: Eighteen of 20 patients had a well-developed callus, while the remaining 2 patients showed delayed fracture healing. In patients with normal callus development, color Doppler imaging demonstrated the progressive formation of new vessels until about 100 days from the surgery; at subsequent examinations, flow signals decreased, and bone remodeling was confirmed by conventional radiography and gray-scale sonography. The resistance indices in these patients tended to decrease in the early weeks after surgery and then slightly increased. In contrast, lack of development of flow signals and persistence of high resistance indices were observed in the 2 patients with delayed fracture healing. CONCLUSIONS: Color Doppler sonography seems to have the capability to predict whether the development of fracture calluses will be normal or delayed.

Adolescent↗
PubMed2000

Accuracy of clinical diagnostic criteria for Friedreich's ataxia.

The accuracy of the diagnostic criteria for Friedreich's ataxia proposed by Harding and by the Quebec Cooperative Study on Friedreich's Ataxia was studied in 142 patients with progressive unremitting ataxia of autosomal recessive inheritance or sporadic occurrence. Eighty-eight patients received the molecular diagnosis of Friedreich's ataxia. Traditional diagnostic criteria are characterized by high specificity, but they yield a high number of false-negative diagnoses. We suggest three levels of diagnostic certainty: (1) possible Friedreich's ataxia, defined as sporadic or recessive progressive ataxia with (a) lower limb areflexia and dysarthria, Babinski sign, or electrocardiographic repolarization abnormalities, or (b) with lower limb retained reflexes and electrocardiographic repolarization abnormalities (95% sensitivity and 88% positive predictive value); (2) probable Friedreich's ataxia as defined by Harding's criteria (63% sensitivity and 96% positive predictive value) or by Quebec Cooperative Study on Friedreich's Ataxia criteria (63% sensitivity and 98% positive predictive value); (3) definite diagnosis, molecularly confirmed.

Adolescent↗
PubMed2000

Immunohistochemical tenascin-C expression in paediatric supratentorial glioblastoma multiforme.

Tenascin-C (TN-C) plays an important part in the growth of neoplastic tissue, leading to new vessel development. TN-C has been assessed in adult glioblastoma multiforme (GBM) and has been evaluated as anti-neoplastic therapy. No studies have focused on this tissue in paediatric GBM. Tissues were obtained from six paediatric supratentorial GBMs. Immunohistochemistry was performed using a mouse antibody directed against human TN-C, and expression in tumour vasculature was described on the basis of TN-C immunoreactivity. The expression was minimal in three, moderate in two, and intense in one specimen. TN-C was not correlated with clinical history, neurological findings, or with tumour site. Although based on a limited number of patients, this study provides additional insights into tumour growth modulation and cytogenetic profile of paediatric GBM. The detailed understanding of events responsible for GBM growth is a prerequisite for the development of therapeutic modalities leading to improved prognosis and cure.

Child↗