Absence of human herpesvirus 8 DNA in benign and malignant endothelial lesions.
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Aged↗
Biomedical subjects
N Romano
Publications and source records attributed to N Romano.
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↗
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↗
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↗
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↗
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↗
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↗
The barley Hooded mutation caused by a duplication in a homeobox gene intron.
In barley (Hordeum vulgare L.) the unit of inflorescence is the spikelet, which bears a fertile bract, the lemma, and the floret consisting of palea, two lodicules, three stamens and the pistil. The Hooded mutation causes the appearance of an extra flower of inverse polarity on the lemma. This phenotype is governed by the single dominant genetic locus K3. Here we show that the homeobox gene Knox3 represents this locus. Ectopic Knox3 gene expression in the primordium of the extra floret is caused by a 305-base pair duplication in intron 4, and phenocopies of the mutation are obtained in the heterologous tobacco system by Knox3 overexpression. It is concluded that homeotic genes of the Knox gene family are involved in floral evocation. Furthermore, the study of polarity of reproductive organs in K and related mutants can now focus on homeobox genes.
Amino Acid Sequence↗
Suppression of gene expression by homologous transgenes.
When a wild-type strain of Neurospora crassa is transformed with different portions of the carotenogenic albino 1 or albino 3 genes, up to 30-35% of the transformants show an albino phenotype. The albino transformants presented a variety of phenotypes ranging from white or yellow to dark yellow colour. The ectopically integrated sequences provoke a severe impairment of the expression of the endogenous al-1 or al-3 genes. This phenomenon, that has been termed quelling, is found to be spontaneously and progressively reversible. In fact, all of the albino transformants have an unstable phenotype and revert progressively to wild type or intermediate phenotypes over a prolonged culturing time. The phenotypic reversion is characterised by a progressive release of the transcriptional inhibition and seems to correlate with the reduction of the number of the ectopic integrated sequences. However, there is no strict correlation between the copy number of the ectopic sequences and the intensity of quelling, as indicated by the existence of albino transformants containing only 1-2 ectopic sequences. The nature of the molecular events determining the onset of quelling is unclear, in any event, these are likely to involve some kind of interaction between the resident genes and ectopically integrated exogenous sequences. Recent evidences on a possible mechanism are presented.
Carotenoids↗
The changing pattern of human immunodeficiency virus type 1 infection in intravenous drug users. Results of a six-year seroprevalence study in Palermo, Italy.
A cross-sectional seroepidemiologic study was carried out between 1985 and 1990 in 1,567 heterosexual intravenous drug users who had been seen at the AIDS Regional Reference Center in Palermo, Italy, to evaluate the rate of human immunodeficiency virus type 1 (HIV-1) seroprevalence in this group and its long-term trend. Sixty serum samples collected from drug users in 1980 and 1983, before the founding of the Center (1985), were tested as well. Some demographic and behavioral risk factors were studied in a subgroup of intravenous drug users enrolled in 1985, 1987, and 1990 for their possible association with HIV-1. These factors were also studied in relation to hepatitis B virus infection, since both viruses share the same modes of spread. These drug users had a higher prevalence of markers for hepatitis B virus than of HIV-1 antibodies, and the prevalence rates in sera collected declined over time for both infections. The presence of both antibodies to HIV-1 and markers for hepatitis B virus was independently associated with the age of the drug user, the duration of drug use, and the year of serum collection. Antibodies to HIV-1 were observed more frequently in females than in males. No relation was found between education or employment status and the presence of HIV-1 antibodies or hepatitis B virus markers. Although new HIV-1 infections still occur, the decline in seroprevalence observed at the end of the 1980s might be related to modifications in social behavior among newer drug users, partial exhaustion of the susceptible population, and increasing risk awareness in more experienced users.
Acquired Immunodeficiency Syndrome↗
Quelling: transient inactivation of gene expression in Neurospora crassa by transformation with homologous sequences.
Up to 36% of Neurospora crassa transformants showing an albino phenotype were recovered by transforming a wild-type strain with different portions of the carotenogenic albino-3 (al-3) and albino-1 (al-1) genes. The presence of the exogenous sequences (which were randomly integrated in ectopic locations) provoked a severe impairment in the expression of the endogenous al-1 or al-3 genes. This phenomenon, which we have termed 'quelling', was found to be spontaneously and progressively reversible, leading to wild-type or intermediate phenotypes. The phenotypic reversion is characterized by a progressive release of the transcriptional inhibition and seems to correlate with a reduction of the number of the ectopic integrated sequences. Moreover, quelling appears to be monodirectional, as, once relieved, it cannot take place again, despite the continuing presence of some of the ectopic sequences in the genome.
Alkyl and Aryl Transferases↗
The Neurospora crassa carotenoid biosynthetic gene (albino 3) reveals highly conserved regions among prenyltransferases.
In the filamentous fungus Neurospora crassa the biosynthesis of carotenoids is regulated by blue light. Here we report the characterization of the albino-3 (al-3) gene of N. crassa, which encodes the carotenoid biosynthetic enzyme geranylgeranyl-pyrophosphate synthetase. This is the first geranylgeranyl-pyrophosphate synthetase gene isolated. Nucleotide sequence comparison of al-3 genomic and cDNA clones revealed that the al-3 gene is not interrupted by introns. Transcription of the al-3 gene has been examined in dark-grown and light-induced mycelia. The analysis revealed that the al-3 gene is not expressed in the dark and that its transcription is induced by blue light (Nelson, M. A., Morelli, G., Carattoli, A., Romano, N., and Macino, G. (1989) Mol. Cell. Biol. 9, 1271-1276). The al-3 gene encodes a polypeptide of 428 amino acids. Comparison of the deduced amino acid sequence of al-3 with the sequences of prenyltransferases of other species, from bacteria to humans, showed three highly conserved homologous regions. These homologous regions may be involved in the formation of the catalytic site of the prenyltransferases.
Amino Acid Sequence↗
Change in size of the envelope glycoprotein of a human immunodeficiency virus 1 (HIV 1) strain.
A strain of HIV 1 (PA 40), isolated from a patient with AIDS, showed a size variation of its external glycoprotein. This glycoprotein had an estimated molecular weight of 105 Kd and differed from that of both HIV 1 IIIb and HIV 2 Rod strains. The protein was derived from a bigger (140 Kd) precursor, detectable only in the infected cells and could incorporate labeled glucose in its prosthetic portion. The change in size of the external glycoprotein may be the result of envelope sequence variations since the unglycosylated form of the envelope precursor of PA 40 strain, detected in tunicamycin treated cells, was smaller than that of the HIV 1 IIIb strain. The different size of the external glycoprotein is a further aspect of the variability of the biological characteristic of HIV 1 strains and might be correlated with the emergence of more virulent variants which arose during the progression of the clinical disease.
Acquired Immunodeficiency Syndrome↗
Free and antibody-complexed antigen and antibody profile in apparently healthy HIV seropositive individuals and in AIDS patients.
The pattern of free and antibody-complexed HIV antigen and the antibody profile were investigated retrospectively in 305 serum samples taken from 22 AIDS patients before and during the development of AIDS and from 40 apparently healthy seropositive individuals. Most AIDS patients were found positive for both free and complexed antigen and had high gp41 antibody titres but low or undetectable p24 antibody. Four different patterns of HIV antigenaemia were observed: 1) positive for both free and complexed antigen; 2) negative for free HIV antigen at first, but always positive for complexed antigen; 3) positive for free antigen without complexed antigen; and 4) negative for both free and complexed antigen. The development of immune complexes preceded the appearance of free antigen and might reflect the ongoing viral replication with antigen excess and binding of anticore antibodies. No correlation was found between the development of AIDS symptoms and either the duration of free antigen positivity or the level of antigenaemia. A different pattern was observed in apparently healthy seropositive individuals: 90% of whom had high antibody titres to p24 and gp41 and were persistently negative for free and complexed HIV antigen. This study demonstrates that testing HIV markers in sequentially collected serum samples from HIV seropositive individuals is a useful and simple tool for early identification of persons at risk of developing AIDS.
Acquired Immunodeficiency Syndrome↗
Neutralizing antibody and clinical status of human immunodeficiency virus (HIV)-infected individuals.
An assay based on inhibition of cytopathic effect of human immunodeficiency virus (HIV) strains in Molt 4 cells was developed to quantitate neutralizing antibodies (NA) in sera of HIV-infected individuals. The assay was specific and gave results comparable to those obtained by the inhibition of immunofluorescence (IFI) and reverse transcriptase (RT) activity. Attempts were made to correlate the presence and the antibody titres with the clinical status of HIV-infected individuals classified according to Walter Reed staging classification scheme. NA titres correlated inversely with the stage of HIV infection: Compared with acquired immunodeficiency syndrome (AIDS) patients, HIV-infected subjects at stage WR1 had significantly higher NA titres. Moreover, a decrease in NA titre in relation to clinical deterioration was noted in sequential sera of eight of 11 AIDS patients, retrospectively examined, for NA. The symptomless subjects showed either the same level of NA or a trend towards an increasing antibody titre with time. Different isolates of HIV strains showed a variability in the extent of sensitivity to neutralization by sera obtained from different HIV-infected individuals.
Acquired Immunodeficiency Syndrome↗
Molecular cloning of a Neurospora crassa carotenoid biosynthetic gene (albino-3) regulated by blue light and the products of the white collar genes.
The albino-3 (al-3) gene of Neurospora crassa, which probably encodes the carotenoid biosynthetic enzyme geranylgeranyl pyrophosphate synthetase, was cloned. The N. crassa triple mutant al-3 qa-2 aro-9 was transformed to qa-2+ with mixtures of plasmids bearing N. crassa DNA inserts, and the transformants were screened for the al-3+ phenotype. One al-3+ qa-2+ transformant (AL3-1) was examined in detail and shown to contain intact vector sequences integrated into the N. crassa genome. The vector and some flanking sequences were recovered from AL3-1 after restriction, ligation, and selection of chloramphenicol-resistant transformants of Escherichia coli. The flanking sequences were subsequently used to detect the al-3-containing plasmid in the mixture of about 1,800 plasmids. Restriction fragment length polymorphism mapping was carried out to confirm the identity of the cloned fragment. The level of the al-3 mRNA was shown to be increased 15-fold in light-induced (compared with that in dark-grown) wild-type mycelia. The light-dependent increase in al-3 mRNA levels was not observed in presumed regulatory mutant (white collar) strains.
Carotenoids↗
No evidence of HIV 2 infection in Sicily.
A seroepidemiological survey was carried out with the aim of establishing whether or not HIV 2 infection could be detected in Western Sicily. Two groups of sera were tested by EIA and WB assay against HIV 1 and HIV 2. 200 sera taken from North African immigrants in the Mazara del Vallo area, and 297 samples taken from AIDS-high risk groups individuals living in Palermo. None of the North African sera was positive to HIV 1 and/or HIV 2 by either techniques. 118 of the 297 sera from Palermo were HIV 1 positive by both techniques; 69 thereof also reacted to HIV 2 by EIA. Only six of these were confirmed by WB assay, showing a clear reactivity against the 140 and 105 HIV 2 glycoproteins. However, all six sera were considered merely cross-reactive to HIV 2, since none of them had neutralizing antibody to HIV 2 and the cross reactivity to glycoproteins of HIV 2 could be removed by absorbing them with HIV 1 infected cells. It seems therefore that HIV 2 has not yet reached our area. Early detection of the possible presence of this virus in our country could be obtained by improving both the surveillance and the effectiveness of laboratory tools for HIV 2 diagnosis.
Acquired Immunodeficiency Syndrome↗
Main routes of transmission of human immunodeficiency virus (HIV) infection in a family setting in Palermo, Italy.
A cross-sectional seroepidemiologic study was carried out on household contacts and sexual partners of human immunodeficiency virus (HIV) antibody-positive intravenous drug abusers in Palermo, Italy, in 1985 to evaluate factors that influenced HIV transmission. A total of 43 index cases, 36 spouses or heterosexual partners, 28 children, and 55 adult household members were enrolled. None of the household members without sexual contact, who had shared items and facilities and had interacted with the index cases, contracted HIV infection. However, six of 36 sexual partners had antibodies to HIV. It was observed that the risk of HIV infection was significantly associated with the frequency of sexual intercourse with the seropositive partner. Four children were also found to be infected: two had acquired immunodeficiency syndrome-related complex, and the other two were clinically and immunologically normal. Furthermore, one other child had evidence of passive transfer of maternal antibodies. The infection was confined to the younger children (ranging in age from eight months to three years). The data support a high rate of vertical transmission from mother to infant, an intermediate rate of transmission to sexual partners, and no transmission attributable to household contact.
AIDS-Related Complex↗