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Biomedical subjects

G Scalia

Publications and source records attributed to G Scalia.

At least 19 recordsLinked to original sources

Human herpesvirus 6 infection in autologous bone marrow transplant recipients: a prospective study.

After primary infection in early life, human herpesvirus 6 (HHV-6) remains latent in the body and may reactivate in subjects with poor immune status. A 180-day longitudinal study of HHV-6 infection was carried out in 23 autologous bone marrow transplant recipients to evaluate reactivation of HHV-6; two of these patients underwent a double transplant. The patients were monitored prospectively for HHV-6 DNA in peripheral blood mononuclear cells (PBMC) by hot start nested PCR. Positive samples were typed by the enzymatic restriction protocol. Positive plasma samples were also tested for HHV-6 DNA. Antibodies against HHV-6 were measured by immunofluorescence. Five and two out of 23 patients had intermittent and persistent positivity to HHV-6 DNA in PBMCs, respectively; four patients carried variant B, and the other three patients both A and B. None of the respective plasma samples were positive. Two patients were positive for HHV-6 antibodies. Since the significance of HHV-6 DNA in PBMCs is unclear, these findings do not necessarily indicate active infection but may be due to mild immunosuppression in autologous BMT recipients.

Antibodies, Viral

Long-lasting decrease of CD4+/CD45RA+ T cells in HCL patients after 2-chlorodeoxyadenosine (2-CdA) treatment.

The CD45RA and CD45RO isoforms of the leukocyte common antigen identify functionally distinct CD4+ T cell subsets: CD4+/CD45RA+ cells which represent a more 'naive' stage of T cell compartment and CD4+/CD45RO+ 'memory' cells. Phenotypic and functional abnormalities in T cell compartment have been frequently reported in patients with hairy cell leukemia (HCL) and, in more recent studies, a significant reduction in the absolute number of CD4+ lymphocytes bearing the CD45RO antigen has also been recorded. In our study we evaluated the CD45RA and CD45RO expression on CD4+ T cells by three-color staining in flow cytometry in 38 HCL patients, 19 untreated and 19 previously treated with 2-chlorodeoxyadenosine (2-CdA), administered at a daily dose of 0.1 mg/kg c.i. for 7 days. In HCL untreated patients, the proportion and the absolute number of CD4+/CD45RA+ and of CD4+/CD45RO+ T cell subsets were similar to normal controls. In contrast, HCL patients at 3-5 years by the end of treatment with 2-CdA, together with a reduction in the absolute number of CD4+ T cells, showed a persistent and significant decrease in the proportion and absolute number of CD4+/CD45RA+ cells as compared with both untreated HCL patients and normal controls (41 +/- 16% vs 57 +/- 14% and vs 65 +/- 7%) (P = 0.01 and 0.0001) and (0.201 +/- 0.137 x 10(9)/l vs 0.549 +/- 0.238 x 10(9)/l and vs 0.696 +/- 0.078 x 10(9)/l) (P = 0.00009 and P = 0.00001). In addition, together with the reduction of CD4+/CD45RA+ cells, we recorded a concomitant increase in the proportion of the CD4+/CD45RO+ cells as compared to untreated HCL patients and normal controls (62 +/- 16% vs 47 +/- 15% and vs 42 +/- 12%) (P = 0.08 and 0.02). These findings may suggest that CD4+/CD45RA+ cells are more sensitive than CD4+/CD45RO+ to the toxic effect of 2-CdA.

Adult

Use of a microquantity enzyme immunoassay in a large-scale study of measles, mumps and rubella immunity in Italy.

The seroprevalence of antibodies to measles, mumps, and rubella viruses (MMR) was determined in 1498 subjects in Catania, Italy, ranging in age from 1 month to 25 years. The study population was divided into seven age groups and screened by enzyme immunoassay using microquantities (10 microl) of whole blood collected by fingerprick on filter paper discs. The results showed that seroconversion for measles (87.6%) and mumps (73.2%) occurred between 6 and 10 years of age. The seroprevalence of antibodies to rubella virus increased slowly through the age groups, reaching the highest rate (93.3%) between 16 and 20 years of age. Passively transmitted maternal antibodies to mumps and rubella were absent in babies between 5 and 8 months of age, and a few cases positive for measles antibodies were found among babies 6 and 7 months of age. The enzyme immunoassay was demonstrated to be suitable for low-cost large-scale screening for MMR immunity. The rate of vaccine failure was also evaluated and found to be 9.5% for the measles virus, 12.9% for the mumps virus and 0.0% for the rubella virus.

Adolescent

Isolation of Porphyromonas gingivalis and detection of immunoglobulin A specific to fimbrial antigen in gingival crevicular fluid.

The present study evaluated the prevalence of Porphyromonas gingivalis and the correlation between the bacterial culture method and the detection of immunoglobulin A (IgA) specific to the P. gingivalis fimbrial antigen in gingival crevicular fluid (GCF). P. gingivalis was isolated from 78.3% of subgingival plaque samples obtained from active sites and 34.7% of those from inactive sites of periodontal patients. P. gingivalis was isolated from only 4.7% of healthy subjects (control group). Immunoglobulins specific to the P. gingivalis fimbrial antigen were detected by enzyme-linked immunosorbent assay (ELISA). The overall agreement between the results of the P. gingivalis culture method and the results of specific IgA detection in periodontal patients was 71.7% for active sites and 58.7% for inactive sites. IgA specific to P. gingivalis was absent in GCF from all of the sites of healthy subjects. The results suggest that P. gingivalis is associated with the local production of specific IgA. The detection of IgA antibodies specific to P. gingivalis in GCF by ELISA may be used as a predictive parameter to reveal the early phase of the activation of recurrent periodontal infections.

Antibodies, Bacterial

Improvement in establishing the period of rubella virus primary infection using a mild protein denaturant.

A more precise determination of the date of primary rubella infection in pregnancy is obtained by application of the urea denaturation method. Two denaturation buffers containing 6 and 8 M urea were compared for the detection of rubella IgG avidity by enzyme immunoassay. The results demonstrate that IgG avidity detected by 6M urea increases more rapidly, from 16% on the third day to 51% on the 46th day after the rash, than that obtained by 8 M urea, from 13 to 36%. The specific rubella IgG avidity detected by 6 M urea denaturation buffer increased significantly in paired sera obtained at an interval of 15 days. The same samples did not show any significant increase of IgG avidity when an 8 M urea denaturation buffer was used. The use of a mild denaturant such as 6 M urea indicates the presumptive date of primary rubella infection in pregnancy within 2 months of sampling.

Acute Disease

Detection of immunoglobulin G to a Sindbis-related virus by a membrane antigen enzyme immunoassay.

We determined the seroprevalence of a Sindbis-related virus isolated for the first time in 1975 from ticks in south-east Sicily and typed by Gresikova et al. in 1978. An indirect enzyme immunoassay based on viral membrane antigen for coating microtiter strips was used for the detection of immunoglobulin G to the Sindbis-related virus. The method appeared more sensitive than a similar enzyme immunoassay based on crude lysate antigen. Comparison of the results obtained from sera tested both by membrane antigen enzyme immunoassay and microneutralization test showed 92% agreement, while the agreement between microneutralization test and crude antigen enzyme immunoassay was 76%. An overall elevated seroprevalence (63.66%) was found in a population group living in and around the area of first isolation and seroprevalence in different age groups was also studied.

Adolescent

Anti-HCMV serologic response in patients with acute viral hepatitis.

The authors point out a high serological incidence of HCMV infection in the course of HCV hepatitis compared to a low incidence detected in HBV and HAV hepatitis. Three immunoglobulin classes (IgG, IgM, and IgA) specific to HCMV were investigated. Antibody titers of each immunoglobulin class are reported for all the cases of HCMV infection.

Acute Disease

Detection of immunoglobulin G to measles virus, rubella virus, and mumps virus in serum samples and in microquantities of whole blood dried on filter paper.

Immunity to measles virus, rubella virus, and mumps virus was determined by EIA in serum samples and in dried whole blood specimens spotted on Whatman filter paper (5 mm in diameter). Both specimens were obtained from each patient by venepuncture and finger prick. Ten microliters of whole blood is enough to detect antibodies to these three different viruses. The comparison of the results obtained by EIA from 227 serum and whole blood samples have demonstrated close agreement: 98.6% for measles virus, 99.1% for rubella virus, and 96.0% for mumps virus. Moreover, 96 whole blood samples can be tested in a microtiter plate and can be stored at room temperature for 15 days or at +4 degrees C for several months. Therefore, whole blood dried on filter paper is a convenient alternative method for collecting and transporting specimens, it is easier and safer than venepuncture, and could be used for large-scale epidemiological studies, especially in newborns. This method could solve the problem of sampling, especially in young children, and could simplify studies of vaccine efficacy.

Adult

Exercise induced vasodepressor syncope.

Five cases of exercise induced pure vasodepressor syncope in patients without significant structural heart disease are reported. Hypotension and symptoms of syncope or pre-syncope were induced by treadmill exercise testing and in each case limited exercise performance. Evidence of inappropriate peripheral vasodilation, probably as a consequence of ventricular mechanoreceptor stimulation, was shown in all five patients. Head up tilt testing resulted in hypotension in four patients and isoprenaline infusion in the supine position resulted in hypotension in the fifth. These patients had a new condition of exercise induced neurally mediated (vasodepressor) syncope without appreciable structural cardiac abnormalities.

Adolescent

Mechanism of exercise hypotension in patients with ischemic heart disease. Role of neurocardiogenically mediated vasodilation.

BACKGROUND: Exercise-induced hypotension in patients with coronary artery disease (CAD) has been considered to be due to an inability to achieve an adequate increase in cardiac output to match the demands of exercise. We investigated 10 consecutive patients (9 men and 1 woman; age, 38 to 71 years; mean, 52 years) with angiographically documented CAD and exercise-induced hypotension (EIH) (BPPeak < BPRest). Ten approximately age- and sex-matched patients with documented CAD and normal exercise blood pressure response (NBP) served as control subjects. METHODS AND RESULTS: Nine patients with EIH and all 10 control subjects underwent forearm plethysmography and radionuclide ventriculography (RNV) during semierect cycle exercise. Forearm vascular resistance (FVR) fell by 35 +/- 21% in exercise-induced hypotension patients versus an increase of 78 +/- 65% in patients with an NBP response (P < .0001). Left ventricular ejection fraction increased by 5.1 +/- 7.5% in the group with EIH versus a fall of 4.1 +/- 6.2% in the control group (P = .004). Cardiac output at peak exercise (RNV) increased by 2.2 +/- 0.89-fold in the group with EIH versus 1.49 +/- 0.47-fold in the control group (P = .04). The tenth patient in the group with EIH underwent invasive hemodynamic evaluation during erect exercise. Systolic blood pressure fell (136/80Rest to 50/40Peak) and cardiac output (Fick) tripled, whereas calculated systemic vascular resistance decreased by a factor of 10. Successful angioplasty to an isolated circumflex lesion resulted in resolution of symptoms and abnormal hemodynamic responses during exercise. CONCLUSIONS: Abnormal vasodilation associated with a normal or even increased rather than decreased cardiac output response appears to be an important mechanism underlying EIH in some patients with CAD. In the present study, this appears to have been the dominant mechanism in 8 and contributory in 2 of the consecutive patients studied.

Adult

Correlation between islet cell antibodies and anti-cytomegalovirus IgM and IgG antibodies in healthy first-degree relatives of type 1 (insulin-dependent) diabetic patients.

To investigate whether cytomegalovirus (CMV) infection may be related to islet cell antibodies (ICA) production and/or to insulin-dependent diabetes mellitus (IDDM) development, we have analyzed the prevalence of anti-CMV, IgM, and IgG antibodies and of ICA in 80 healthy siblings of IDDM patients (HSIDDP) and in 60 control subjects with negative familiar anamnesis of IDDM. HSIDDP and controls were also typed for HLA-A-B-C and DR antigens. IgM and IgG anti-CMV were detected by an ELISA method, whereas the ICA assay was performed by standard indirect immunofluorescence on 5-microns unfixed sections of human pancreas. HLA-A-B and C antigens were studied by standard microlymphocytotoxicity; DR antigens were also studied by a standard microlymphocytotoxicity on a B-enriched lymphocyte population. Our results indicate a significant association (P less than 0.0001) between high titers of anti-CMV IgG antibodies and ICA in HSDIDDP, whereas no correlation was found between the presence of any HLA-A-B-C and DR antigens and the prevalence of anti-CMV IgM and IgG antibodies and/or ICA. Thus, these data may support the hypothesis that a chronic CMV infection may be associated with ICA production whereas other factors seem to be needed for the complete development of type 1 diabetes.

Adolescent

Detection of rubella virus antigen by one-step time-resolved fluoroimmunoassay and by enzyme immunoassay.

A one-step time-resolved fluoroimmunoassay (TR-FIA) and a conventional two-step enzyme immunoassay (EIA) for the detection of rubella virus antigen were developed. Two noncompetitive mouse monoclonal antibodies reactive with epitopes on the E1 polypeptide of rubella virus served as immunoreagents. One of the monoclones (7A6) was used for coating the solid phase, and the other (2C3) was labeled with either Europium chelate or with horseradish peroxidase. For TR-FIA, the specimen was incubated simultaneously with the label at 4 degrees C overnight. EIA required an overnight incubation with the specimen and after washing another 1 hr of incubation at 37 degrees C with the conjugate. The sensitivity of TR-FIA was 10 pg in an assay volume of 100 microliters, and the sensitivity of EIA was between 50 and 100 pg. Antigens could be detected by TR-FIA in supernatant of cultures of Vero cells 48 hr after inoculation with approximately 1 TCID50, while cytopathogenic effect (CPE) at that time was detected only in cultures inoculated with 10(5) TCID50 or more. Virus mixed with human amniotic fluid containing antirubella-specific IgG was detectable after an incubation at 37 degrees C for 5 days. The assays may find applications in prenatal diagnosis of intrauterine rubella infection, in early identification of viral antigens in cell culture and in monitoring production, concentration, and purification of rubella antigen for antibody assays.

Amniotic Fluid

Steady-state pattern electroretinogram in insulin-dependent diabetics with no or minimal retinopathy.

Steady-state pattern electroretinogram (PERG) in response to sinusoidal gratings (1.7 c/deg spatial frequency; 9 x 9 deg field size) temporally modulated (sinusoidally) at 8 Hz were recorded in 40 insulin-dependent diabetics and 28 age-matched normal subjects. Visual acuity was greater than or equal to 20/20 in all 40 patients; 31 (62 eyes) showed no sign of retinopathy and nine (18 eyes) showed a few microaneurysms on fluorescein angiography. Insulin-dependent diabetics showed a significant reduction in the PERG mean amplitude as compared with age-matched control subjects (one-way analysis of variance: p less than 0.0001). Significant differences were observed between normals and diabetics without retinopathy (Scheffé test: p less than 0.0001), normals and diabetics with early retinopathy (Scheffé test: p less than 0.0001), no retinopathy and early retinopathy patients (Scheffé test: p less than 0.05). In diabetics without retinopathy multifactorial analysis of variance revealed a significant effect of age of onset of the disease (p less than 0.01) and an interaction effect between age of onset and duration (p less than 0.001) on PERG amplitude. These results suggest a possible use of the steady-state PERG to detect early macular dysfunction in insulin-dependent diabetics.

Adult

Coxsackie virus and urogenital pathology.

In 43 women (average age 49.6 years), and 70 men (average age 55.2 years) with pathology of the genito-urinary apparatus, seroantibodies to Coxsachie virus B were measured using the passive hemoagglutination method and the virus was isolated in the uterine. Viral isolation test was negative in all urine samples tested. Seropositivity for Coxsackie virus was reported in 26 women (60.46%) and in 51 men (72.85%). Positivity to B1 was 37.16% (42 cases), B2 in 38.05% (43 cases), and to B4 in 35.39% (40 cases). 17.69% (20 cases) of patients were seropositive to only one serotype, 17.69% (20 cases) to 5 serotypes, 14.15% (16 cases) to 3 serotypes, 9.73% (11 cases) to 2 serotypes, and 8.84% (10 cases) to 4 serotypes. B1, 2, 3, 4, 5 (25.97%; 20 cases) and B2, 3, 4, 5 (7.79%; 6 cases) were the most frequent associations. Seropositivity to Coxsackie virus was reported in 100% of patients (4 cases) with urethral caruncola, in 84.21% (16 cases out of 19) with cancer of the bladder, in 81.81% with cystitis (9 cases out of 11) and in 80% with prostatitis (8 out of 10 cases). In relation to sex, seropositivity was higher in males in cases of calculosis (75%; 9 cases out of 12 against 28.57%; 2 cases out of 7) and in cystitis (100%; 6 cases against 60%; 3 cases out of 5). Further studies are necessary to determine the clinical significance of serum Coxsackie virus antibodies in patients with urological pathology in the absence of urinary elimination of Coxsackie virus.

Antibodies, Viral

Changes in spatial tuning of the pattern electroretinogram with age.

Experimental and clinical studies have demonstrated that the electroretinogram in response to periodical patterns alternating in contrast at constant mean luminance (pattern reversal ERG, P-ERG), is correlated with ganglion cell activity. Senile functional changes of these neurons might be therefore investigated by the P-ERG technique. Steady-state P-ERGs (8 Hz) in response to sinusoidal gratings of different spatial frequencies (0.6-6.8 c/d) were recorded in normal subjects ranging over 50 year age span. The P-ERG amplitude as a function of stimulus spatial frequency shows a maximum between 1.2-1.7 c/d and attenuation at higher and lower spatial frequencies (spatial tuning). The P-ERGs of the older subjects are reduced in amplitute, as compared to those of the younger ones, over the whole range of spatial frequency. This reduction is more marked at intermediate spatial frequencies resulting in a shallower tuning.

Adult

Macular electroretinogram as a function of age of subjects.

Macular and paramacular electroretinograms in response to two adjacent checks (6 deg/side), alternating at constant mean luminance, were recorded in 34 normal subjects ranging in age from 16 to 74 years. The macular electroretinogram declines progressively in amplitude with age (R = -0.42; P = 0.013). The amplitude ratio between macular and paramacular responses tends to be independent of age (R = -0.21; P = 0.22). Age-related changes in the macular electroretinogram shown in our study are consistent with previous anatomical and functional studies, which indicate a deterioration of photoreceptors beyond 20 years of age. These results suggest a possible use of this technique for future studies on macular degeneration.

Adolescent