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Biomedical subjects

N Romano

Publications and source records attributed to N Romano.

At least 19 recordsLinked to original sources
PubMed2000

Immunopurification of T-cells from sea bass Dicentrarchus labrax (L.).

The monoclonal antibody DLT15, specific for thymocytes and peripheral T-cells of the teleost fish Dicentrarchus labrax (sea bass), was used to purify immunoreactive cells from blood and gut-associated lymphoid tissue. The purification was performed by immuno-magnetic sorting of leucocyte fractions enriched by Percoll density gradient centrifugation, and the purity of the isolated cells was estimated by cytofluorimetric analysis. Following a single step, the percentage of DLT15-purified cells was 88 +/- 10% for gut-associated lymphoid tissue and 79 +/- 18% for blood leucocytes. DLT15-purified cells from gut-associated lymphoid tissue were employed for RNA extraction and cDNA synthesis. In RT-PCR experiments using as primers degenerate oligonucleotides corresponding to the peptide sequence MYWY and VYFCA of the trout TcR beta chain, a 203 bp product was amplified. When sequenced, the cDNA was found to show 60% nucleotide identity to the trout TcRV beta 3. By 3'-RACE the cDNA was elongated to obtain the TcR constant region, with high similarity to other fish TcR sequences. These results strongly suggest that cells recognised by DLT15 are putative T lymphocytes.

Amino Acid Sequence↗
PubMed2000

Soluble tumor necrosis factor alpha receptors (sTNF-Rs) in HIV-1-infected intravenous drug users: change in circulating sTNF-R type II level and survival for AIDS patients.

UNLABELLED: This study in intravenous drug users (IVDUs) investigated differences in serum soluble tumor necrosis factor types I and II (sTNFR-I and II) concentrations in HIV-1-infected IVDUs and controls. This study also investigated whether changes of sTNFRs concentration affect the risk of death among patients with AIDS. A cross-sectional study of 54 subjects with AIDS, 47 HIV-seropositive IVDUs, 47 HIV-seronegative IVDUs, and 21 healthy subjects showed that sTNFRs concentration increases from healthy controls to AIDS patients through HIV-seronegative and HIV-seropositive subjects (p < 0.01). sTNFR-I concentration, however, was shown to be similar in HIV-seronegative IVDUs and healthy controls. In the longitudinal study, serum concentration of sTNFRs was determined near AIDS diagnosis in 21 IVDUs and 1 year later (start for the survival study). Cox proportional hazards regression was performed to assess the prognostic value of percent change of sTNFR level alone and in combination with T lymphocyte subsets, HIV-p24 antigenemia and opportunistic infections for death within 240 days. Uni- and multivariate Cox modelling for dichotomised variables according to its median showed an increase of sTNFR-II by at least 30% to be single significant predictor of death: crude relative risk 3.69, p = 0.03; adjusted relative risk 5.67, p = 0.02. Mean survival was 126 days in 11 patients whose sTNFR-II level increased by at least 30%, and 176 days in 10 patients with less change in sTNFR-II (p = 0.02). CONCLUSIONS: sTNFRs concentration is higher in IVDUs than in healthy controls and is highest in AIDS patients. Survival of patients with AIDS is associated with variation in the concentration of sTNFR-II.

Acquired Immunodeficiency Syndrome↗
PubMed2000

Antibodies to human herpes virus type 8 (HHV8) in general population and in individuals at risk for sexually transmitted diseases in Western Sicily.

BACKGROUND: Human herpes virus 8 (HHV8) appears to be the primary aetiologic agent of Kaposi sarcoma (KS). To study the distribution of HHV8, a seroepidemiological study was carried out in western Sicily, where a high incidence rate of classical KS is well documented. METHODS: A total of 970 sera of healthy human immunodeficiency virus (HIV) negative individuals of general population (1-70 years old) and 742 sera of individuals in different risk groups for HIV infection were evaluated by means of an indirect immunofluorescence assay able to detect antibodies to lytic and latent HHV8 antigens. RESULTS: Crude seroprevalence to HHV8 antigens was 11.5% in the general population, and it increased significantly with age from 6% under age 16 to 22% after age 50. Significantly higher HHV8 seroprevalence rates were detected among HIV positive and negative homosexual men (62% and 22%, respectively), men who had sex with prostitutes (40% and 29%, respectively); female prostitutes (42% and 30%, respectively), and clients at a sexually transmitted disease clinic (male: 60% and 33%, respectively, female: 63% and 43%, respectively). In contrast, heterosexual intravenous drug users had seroprevalence rates comparable to those found in the general population. CONCLUSIONS: The results suggest that HHV8 infection is widespread in Western Sicily. The high seroprevalence in individuals with high risk sexual activity point to the role of sexual behaviour in the transmission of the infection in adults, whereas the detection of antibodies in younger population (under 16 years old) is suggestive of a non-sexual route of transmission, probably occurring during childhood by close personal contact.

Adolescent↗
PubMed1999

Histological and cytological studies on the developing thymus of sharpsnout seabream, Diplodus puntazzo.

The structure of the developing thymus of the marine teleost, Diplodus puntazzo, was studied by light and transmission electron microscopy. The first anlage of the thymus developed by d 20 postfertilisation (p.f.) as a group of undifferentiated cells dorsal to the epithelium of the branchial chamber. The organ increased significantly in size around d 51-66 p.f. and differentiation of cortex and medulla occurred concomitantly. On the basis of their localisation, 4 main types of epithelial cell were distinguished: (1) limiting, adjacent to the connective capsule; (2) medullary and cortical reticular cells; (3) nurse cells, located in the corticomedullary boundary; (4) Hassall-like corpuscles. The majority of medium to large blast-like lymphoid cells were localised in the medulla, while small lymphocytes were housed in the cortical region. These morphological features were maintained at later stages. However, in juveniles in the medulla we observed reticular epithelial cells with cysts and rare Hassall-like corpuscles. The study was designed to obtain more information concerning the histology of the developing thymus of sharpsnout seabream and give a concise description of the differentiation of epithelial cells and lymphoid cells in the thymic parenchyma.

Animals↗
PubMed1999

Retinal degeneration associated with ectopia lentis.

Two brothers had retinal degeneration, lens subluxation, and myopia since early life. There was no evidence of Marfan syndrome, homocystinuria, or other systemic disease. They had nystagmus, myopia, inferior dislocation of the lens, and posterior subcapsular opacities in both eyes. Fundus examination showed attenuated retinal vessels, macular atrophy with occasional pigment accumulation as clumps, and perivascular sleeves. Electroretinography revealed decreased photopic and scotopic responses. The visual fields were constricted. We believe this to be the first report of retinal degeneration with bilateral lens subluxation in a family. It appears to be inherited in an autosomal recessive fashion.

Adult↗
PubMed1999

Inhibition of human immunodeficiency virus 1 (HIV-1) by variant B of human herpesvirus 6 (HHV-6).

Four HHV-6 strains were initially isolated during attempts to observe HIV-1 replication in cultured primary lymphocytes from 48 patients with AIDS. HHV-6 DNA from each strain was extracted from primary cell cultures and amplified using specific primers in a nested polymerase chain reaction (PCR) assay. All HHV-6 strains were classified as B variants by submitting the PCR products to the digestion of two restriction enzymes (Hind III and Bgl II). Since in primary cultures, the appearance of HHV-6 cytopathic effect was followed by a progressive reduction of HIV-1 replication, we tried to reproduce the observed inhibition in vitro. Two HHV-6 strains, used throughout the experiments, showed their ability to suppress HIV-1 replication when the viruses co-infected CD4+T lymphocyte cultures. While the intrinsic mechanism of this finding still remains unclear, the inhibition of HIV-1 replication was observed only when a high multiplicity of infection (m.o.i.) of HHV-6 and a low m.o.i. of HIV-1 were used in dually infected cell cultures. By using a semiquantitative determination of HIV-1 cDNA by PCR, it appears that the inhibition begins in infected cell cultures and, once established, does not allow any further HIV-1 replication.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Distribution of macrophages during fish development: an immunohistochemical study in carp (Cyprinus carpio, L.).

A monoclonal antibody against carp macrophages (WCL15) has been utilised in flow cytometry, immuno-histochemistry and immuno-electron microscopy to assess the distribution of monocytes/macrophages in developing carp lymphoid tissues. In suspensions of living cells WCL15 reacted strongly with cytoplasm and plasmic membrane of macrophages. It also cross-reacted with a subpopulation of thrombocytes, but this reaction could be neglected by double immunostaining in combination with a thrombocyte-specific marker. In Bouin-fixed tissues the antibody distinctly recognised macrophages. Macrophages were found from day 2 post-fertilisation in head kidney and in the dorsal portion of the yolk sac epithelium. From 1 week onwards macrophages were found scattered in thymus and gut and during the second week in spleen. Macrophages increased in number in all lymphoid tissues until the 6-8th week post-fertilisation, but they decreased except in thymus, where they became localised mainly in the cortical-medullary boundary, and in white pulp areas of head kidney. The role of macrophages in allowing an early non-specific defence in young fish and in co-operating during the differentiation processes of T-cells and B-cells is discussed.

Animals↗
PubMed1998

Distribution of hepatitis C virus genotypes among intravenous drug users. A ten-year study in Palermo, Sicily.

A cross-sectional study was carried out on the sera of 88 active intravenous drug users (IVDU) collected between 1985 and 1986 to evaluate the circulation of HCV genotypes in Western Sicily. The patients were grouped by age and classified by their HIV status. Genotype 3a (48.8% of all cases) was most frequently detected, followed by genotype 1a (20.4%) and type 1b (17.0%). No significant differences in HCV genotype distribution were observed between HIV positive and negative individuals. Next, the HCV genotype distribution found in sera samples of IDVUs drawn between 1985 and 1986 was studied and divided into three age groups. The genotype distribution in the younger group was then compared with samples collected ten years later, between 1995 and 1996, from young HIV negative IVDU individuals. A different distribution between HCV genotypes 3a and 1a was found with a relative, though not significant, increase in the detection of genotype 1a (38%). Finally, sera from six IVDUs obtained at three different times over a ten-year period were genotyped for HCV. None of the subjects showed any change in the genotype found at the first sampling throughout the ten years. The results suggest that a) genotype 1a and 3a are the most common among IVDUs in Western Sicily, b) concurrent HIV infection does not seem to influence HCV genotype and c) infected IVDUs harbor almost exclusively one genotype.

Adolescent↗
PubMed1997

Immunocytochemical detection and cytomorphology of lymphocyte subpopulations in a teleost fish Dicentrarchus labrax.

The monoclonal antibodies DLT15 and DLIg3 directed against thymocytes and serum immunoglobulins of the sea bass (Dicentrarchus labrax, L.) were used to study cells from the thymus, head kidney, spleen, gut-associated lymphoid tissue and peripheral blood leukocytes of this fish by immunofluorescence and pre-embedding immunoelectron microscopy. Immunofluorescence and flow cytometry of leukocyte fractions revealed a large number of DLT15-positive cells in the thymus (approximately 80%) and intestine (approximately 55%) and fewer cells in the spleen (approximately 7%), head kidney (approximately 6%) and peripheral blood (approximately 3%). DLT15-positive cells had two main morphologies, both detectable among thymocytes: a large round heterochromatic nucleus with light sparse cytoplasm (type a) and an irregular and heterocromatic nucleus with cytoplasm rich in polysomes and mitochondria (type b). Type b was most represented in spleen, head kidney, intestine and blood. We suggest that the type b morphology represents more differentiated lymphocytes. Flow cytometry revealed numerous DLIg3-positive cells in the head kidney (approximately 33%), spleen (approximately 30%) and peripheral blood leukocytes (approximately 21%) and fewer positive cells in the intestine (approximately 3%) and thymus (approximately 2%). DLIg3-positive cells had the morphology of lymphocytes (with a large round nucleus) or macrophages in all tissues. Plasma cells lacked membrane immunoreactivity. This is the first ultrastructural characterisation of putative T- and B-lymphocyte subpopulations in a fish species; these subpopulations are differentially distributed in teleost lymphoid organs.

Animals↗
PubMed1997

Human herpesvirus type 8 DNA sequences in biological samples of HIV-positive and negative individuals in Sicily.

OBJECTIVE: To evaluate the circulation of a new human herpesvirus (HHV), HHV-8 or Kaposi's sarcoma (KS)-associated herpesvirus in a geographical area where a high incidence rate of classical KS was already present before the appearance of the AIDS epidemic. DESIGN AND METHODS: The study was carried out by analysing: (i) bioptic samples from classic, AIDS-associated KS, and controls; (ii) peripheral blood mononuclear cells (PBMC) from classic KS, HIV-positive subjects with and without KS and healthy HIV-negative individuals; (iii) semen samples from heterosexual HIV-positive and HIV-negative individuals affected or not by KS; and (iv) cervical swabs from HIV-negative healthy heterosexual females. All specimens were tested for the presence of HHV-8 DNA sequences by a two-step polymerase chain reaction. RESULTS: Positive results were obtained in 90% of bioptic samples of classic KS and in 100% of AIDS-associated KS. Viral sequences were also present in 50% of PBMC of subjects with classic KS and AIDS-associated KS, in 10% of AIDS patients without the angiosarcoma and in 11% of healthy HIV-negative individuals. Finally, HHV-8 DNA was detected in 13% of semen of HIV-negative heterosexual individuals and in 10% of AIDS patients without KS. Both PBMC and ejaculates from the same individual gave positive results. No HHV-8 sequences were found in cervical swabs. CONCLUSIONS: HHV-8 is widespread in the general population in Sicily since it was detected in PBMC and semen of heterosexual HIV-negative individuals and is not found only in high-risk groups. The viral load appears to be more elevated in a high-risk population and it may be ascribed to a viral reactivation. The higher incidence rates of KS in Sicily compared with northern Italy and other European countries might be related to the presence of HHV-8 in the general population.

AIDS-Related Opportunistic Infections↗
PubMed1996

Mild RIP-an alternative method for in vivo mutagenesis of the albino-3 gene in Neurospora crassa.

We have used a biological phenomenon that occurs in Neurospora crassa, termed Repeat-Induced Point mutation (RIP), to create partially functional mutant alleles of the albino-3 (al-3) gene encoding geranylgeranyl pyrophosphate synthase, an enzyme involved in the biosynthesis of carotenoids and diverse prenylated compounds. A total of 70 RIP-induced al-3 mutants were identified by their pale albino phenotype, resulting from inactivation of carotenoid bio-synthesis. Nucleotide sequence analysis of the al-3 gene in five of the RIP-induced mutants revealed that in each case RIP had introduced no more than six point mutations. The low frequency of RIP mutants (0.42%) and the isolation of only leaky mutants with very few mutations suggest that ascospores containing a heavily mutated al-3 gene do not survive. These results are evidence that the RIP phenomenon, used to inactivate and silence duplicated genes in N. crassa, may be exploited in its mild version as a method of sequence-specific in vivo mutagenesis to obtain functional mutant alleles of Neurospora genes. This mild form of mutagenesis may be particularly advantageous in selecting for leaky mutations in essential Neurospora genes.

Alkyl and Aryl Transferases↗
PubMed1996

Influence of partial decerebration and hypophyseal allograft on differentiation of thymic epithelial cells in chick embryos: an ultrastructural study.

The thymus of 18-day-old normal-chick embryos, partially decerebrated chick embryos, and partially decerebrated embryos bearing hypophyseal allografts were analysed by light and transmission electron microscopy. The hypophyseal influence on the cytological differentiation of epithelial components has been studied. The thymus of partially decerebrated embryos showed a delayed differentiation of some types of epithelial cells and a marked decrease in number of lymphoid cells. Partially decerebrated embryos with hypophyseal implants showed a consistent recovery in the degree of differentiation of epithelial components. These findings indicate the influence of the hypophysis in establishing a correct environment for stromal cell differentiation.

Animals↗
PubMed1996

Rare association of human herpesvirus 6 DNA with human papillomavirus DNA in cervical smears of women with normal and abnormal cytologies.

We investigated by nested PCR the possible association of human herpesvirus 6 (HHV-6) and human papillomavirus (HPV) genomes in the cervixes of 109 women with normal and abnormal cytological smears. HPV DNA was detected in 8.33% of 24 women with normal cytologies and in 41.1% of 85 women with abnormal cytologies; the proportion of HPV DNA was directly related to the severity of the lesions. HHV-6 DNA was found in only one patient, who had a cytological pattern of koilocytosis. The HHV-6 genome was classified by restriction enzyme analysis as variant B. The study indicates that detection of the HHV-6 genome in the cervixes of women with a wide spectrum of gynecological complaints is a rare event and rules out the possible association between HHV-6 and HPV genomes in cervical cancer lesions.

Adult↗
PubMed1996

Evaluation of fatty acids in membrane phospholipids of erythrocytes in retinitis pigmentosa patients.

Several investigators have observed abnormalities of plasma DHA in various common forms of retinitis pigmentosa. Erythrocyte membranes are an accessible tissue which may more closely reflect neural membrane fatty acid levels, but little data is yet available on their fatty acid composition in retinitis pigmentosa patients. We have evaluated the DHA levels in red blood cells membrane phospholipids in various genetic forms of retinitis pigmentosa and relative controls. The results obtained indicate significantly lower DHA levels in red blood cell membrane phospholipids in retinitis pigmentosa patients with respect to controls (p < 0.01). This data is significant for autosomal dominant forms only (p < 0.01). Fatty acid content alterations in membrane phospholipids of red blood cells may be considered as markers for abnormalities in the lipid metabolism which disturb the retina integrity.

Adolescent↗
PubMed1996

Fatty acid composition of membrane phospholipids of cataractous human lenses.

The effect of lipid peroxidation on fatty acid composition in membrane phospholipids of transparent and cataractous lens nuclei was investigated. The preliminary results demonstrate a trend toward an increase in the content of palmitic acid with a decrease in the content of oleic acid, linolenic acid and docosahexaenoic acid in the opaque nuclei as compared to the transparent ones of senile cataractous lenses.

Cataract↗
PubMed1996

Ultrastructural study on the plical epithelium of the bursa of Fabricius in chick embryos: influence of partial decerebration and hypophyseal allografts.

The bursa of Fabricius of 18 day normal and partially decerebrated chick embryos, and partially decerebrated embryos bearing a hypophyseal allograft was analysed by scanning and transmission electron microscopy, focusing on the ultrastructural characterisation of the plical epithelium. The plicae of the normal bursa consist of interfollicular (IFE) and follicle associated epithelium (FAE). The FAE is composed of typical polygonal cells and is supported by a layer of epithelial cells which appears as a continuation of the corticomedullary epithelium. Bordering cells lie between the FAE and IFE. The IFE is composed of 4 cell types: (1) undifferentiated, (2) goblet, at various stages of maturity, (3) prismatic, and (4) globular light cells. Partially decerebrated embryos showed a gross impairment of plical epithelium development and the complex of FAE and IFE cells was largely undifferentiated. Partially decerebrated embryos with a hypophyseal allograft displayed the same cellular types as observed in controls, thus indicating a restored differentiation of plical epithelium. These findings suggest that the hypophysis affects the differentiation of plical epithelium during ontogenesis.

Animals↗