Two new formulas for triangulation number T.

The present paper reports two new formulas for calculating triangulation number T. T = L2/l2 and T = 1.45 r2/l2, where L is the distance between pentons, l the distance between any two adjacent capsomeres, r the radius of viral nucleocapsid. The formulas have been verified and applied. It is worth noticing that the triangulation number, viral size and distance between capsomeres are fully connected by the formula r/the square root of Tl = 0.83, and the capsid parameters of all icosahedral viruses are unified in one constant, 0.83.

Manual de bioseguridad para VIH/SIDA / Biosafety manual on HIV/AIDS

Presenta las normas univerales de aplicación de los principios de lucha contra las infecciones en la práctica cotidiana del personal de salud. Destaca la importancia de la observación de las normas de prevención de transmisión de los agentes presentes en la sangre como el virus de la hepatitis B, con muchas más probabilidades de ser transmitido por accidentes en el trabajo

Oral melanotic macules in patients infected with human immunodeficiency virus.

A group of 217 patients seropositive for human immunodeficiency virus (HIV) were studied for 2 years, during which time pigmented lesions of the oral mucosa developed in 14 (6.4%) of them. The lesions were well circumscribed in some cases and diffuse in others. In some patients the macules enlarged or recurred after surgical excision. In two patients the macules appeared during the administration of zidovudine. Clinical and laboratory evidence of adrenal insufficiency was not detected in any of the patients examined. The histologic appearances were those of melanotic macules. No ultrastructural alterations of the melanocytes were observed. Two of these macules also contained Epstein-Barr virus, and in one case normal oral mucosa was examined and also contained Epstein-Barr virus in the epithelial cells. As a control group we examined 180 health care workers who did not belong to any risk category, and 30 intravenous drug abusers who tested seronegative to HIV. Oral melanotic pigmentation was found in eight of the control subjects (3.6%). The difference was not statistically significant (p = 0.3097). Our study shows that oral macules do not occur more frequently in HIV-infected patients. However, the clinical behavior of these lesions appears to be different during the course of HIV infection. In some HIV-infected patients the cause of the macules might relate to the administration of zidovudine and antifungal or antibacterial drugs. In others the cause remains unknown and could be due to multiple factors.

Inhibition of HIV replication by Hyssop officinalis extracts.

Crude extracts of dried leaves of Hyssop officinalis showed strong anti-HIV activity as measured by inhibition of syncytia formation, HIV reverse transcriptase (RT), and p17 and p24 antigen expression, but were non-toxic to the uninfected Molt-3 cells. Ether extracts from direct extraction (Procedure I), after removal of tannins (Procedure II), or from the residue after dialysis of the crude extract (Procedure III), showed good antiviral activity. Methanol extracts, subsequent to ether, chloroform and chloroform ethanol extractions, derived from procedure I or II, but not III, also showed very strong anti-HIV activity. In addition, the residual material after methanol extractions still showed strong activity. Caffeic acid was identified in the ether extract of procedure I by HPLC and UV spectroscopy. Commercial caffeic acid showed good antiviral activity in the RT assay and high to moderate activity in the syncytia assay and the p17 and p24 antigen expression. Tannic acid and gallic acid, common to other teas, could not be identified in our extracts. When commercial products of these two acids were tested in our assay systems, they showed high to moderate activity against HIV-1. Hyssop officinalis extracts contain caffeic acid, unidentified tannins, and possibly a third class of unidentified higher molecular weight compounds that exhibit strong anti-HIV activity, and may be useful in the treatment of patients with AIDS.

Application of electrospray mass spectrometry to the characterization of recombinant proteins up to 44 kDa.

Mass measurement by electrospray mass spectrometry (ESMS) is used as a rapid preliminary verification of the identity of various recombinant proteins ranging from 7 to 44 kDa with an accuracy of 0.01-0.03%. ESMS not only improves the speed but also the reliability of the protein structure determination when used in conjunction with other methods of protein analysis. Modifications of these large molecules, for example the loss of C-terminal amino acids, N-terminal acetylation, 2-mercaptoethanol addition to a cysteine, and trace formation of a covalent dimer (3%), are easily detected individually or in mixtures by mass measurement using ESMS; feats which would be very difficult to achieve using classical biochemical methods. As little as 1% of several structurally related protein contaminants have been identified in a 15 kDa recombinant protein preparation.

Quantitation of human immunodeficiency virus DNA by using the polymerase chain reaction.

The polymerase chain reaction was used to measure the DNA copy number of human immunodeficiency virus (HIV). Differences in polymerase chain reaction amplification efficiency were controlled by amplifying known amounts of HIV DNA in parallel with samples. This technique is a sensitive, accurate, and reproducible method for the quantitation of HIV DNA.

Peptide mapping on HIV polypeptides expressed in Escherichia coli. Quality control of different batches and identification of tryptic fragments containing residues of aromatic amino acids or cysteine.

Peptide mapping was used for the quality control of different batches of the recombinant HIV proteins p24 core and p24-gp41, expressed in Escherichia coli. These proteins comprise gag and env region polypeptides of the virus and may serve as suitable components in the diagnosis of HIV infections. The proteins were digested with trypsin and the mixtures were subjected to peptide mapping to prove batch equivalence of p24-gp41 and to isolate fragments of the p24-gp41 digest that differ from those of the p24 core digest. The proteins were reduced with dithiothreitol and the cysteine residues were derivatized by addition of 4-vinylpyridine. Peptide mapping was performed by means of reversed-phase high-performance liquid chromatography. Batch equivalence was proved by comparison of the maps. Peaks present in one map but not in the other were considered to be due to sequence differences or variability in digestion.

Preparation of 35S-labeled polyphosphorothioate oligodeoxyribonucleotides by use of hydrogen phosphonate chemistry.

The title compounds were chemically synthesized as their 5'-dimethoxytrityl derivatives by base-catalyzed reaction of 35S-enriched elemental sulfur with support-bound hydrogen phosphonate oligomer. This was derived from adamantane carbonyl chloride-activated coupling of nucleotide hydrogen phosphonate monomers, and similarly activated capping with isopropyl phosphite. A convenient, disposable, reversed-phase cartridge was utilized to purify and isolate the 5'-dimethoxytrityl derivative for subsequent in situ detritylation and elution of the final product. The specific activity obtained for the title compounds was ca. 10(7) cpm/mumols-eq P(O)S-. The procedure should be readily adaptable to appropriate syntheses of other P-S containing analogs of DNA and RNA.

Pesquisa de anticorpos HIV-1 em pacientes com paracoccidioidomicose ativa / HIV-1 antibodies in patients with active paracoccidioidomycosis

A literatura médica, no Brasil, registra rasos casos de paracoccidioidomicose em pacientes aidéticos (Bernard et al., em publicaçäo; Carnaúba et al.; Pedro et al; Goldani et al. e Bakos et al. totalizando 7 (sete) observaçöes, publicadas ou comunicadas em congressos. Esta ocorrência contrasta com a grande freqüência de candidíase (incluindo formas profundas), criptococose e histoplasmose, associadas a infecçäo pelo vírus HIV. Tal fato talves possa ser explicado por ser a AIDS síndrome infecciosa predominante urbana e a paracoccidioidomicose doença essencialmente de zonas rurais. Em soros de 50 pacientes com paracoccidioidomicose, 40 do sexo masculino (80%) e 10 do sexo feminino (20%) foram pesquisados anticorpos HIV-1 pela técnica ELISA e, em 19 casos limítrofes (38%) foi realizado teste confirmatório, pela técnica de Western-blot. Somente em um caso de paracoccidioidomicose foram detectados anticorpos específicos HIV-1 em 5 pacientes (10%) foram revelados anticorpos, provavelmente inespecíficos, anti-p24; gp160 em 3 casos (6%); gpl120 em dois casos (4%); e gp3 em um caso (2%). Dos sete soros de pacientes com bandas consideradas inespecíficas, repetidas as provas sorológicas para AIDS, com amostras colhidas alguns meses após (ver dados anexos), apenas em 1 foram registrados resultados positivos, com faixas de baixa intensidade. Tais pacientes, examinados na época, näo apresentaram nenhuma manifestaçäo clínica de AIDS ou de pré-AIDS

Prevalencia de enfermedades de transmisión sexual en las mujeres de Costa Rica / Prevelency of sexually transmitted diseases in CostaRican woman

Pocos estudios han descrito la epidemiología de las infecciones por enfermedades de transmisión sexual (ETS) basándose en muestras serológicas representativas de la población en general y no solo en grupos selectos de pacientes. Ello se debe a la dificultad para obtener serologías en muestras representativas de la población y a la falta de información sobre el historial médico y sexual de los pacientes para quienes existen estudios serológicos. Por otra parte, es solo en años recientes que se ha desarrollado una prueba serológica lo suficientemente específica para diferenciar los anticuerpos a los tipos 1 y 2 del virus del Herpes simplex (VHS) (1) lo que ha hecho posible estimar con precisión la prevalencia de la infección con el VHS de tipo 2 (VHS-2): una de las más importantes ETS. El presente artículo se base en las pruebas serológicas y la información de una muestra nacionalmente representativa de las mujeres de Costa Rica. Describe la prevalencia de anticuerpos al virus del Herpes simplex tipos 1 y 2, sífilis, chlamydia, virus de inmunodefiencia humana (HIV-1) y virus linfotrópico de células humanas-T (HTLV-1) según características demográficas, médicas y sexuales. El artículo también muestra la distribución regional de la prevalencia de anticuerpos a esto agentes

The detection of HIV by in situ hybridization.

A simplified method of in situ hybridization is described for the detection of HIV targets. This standardized method can be applied to sections of formalin-fixed paraffin-embedded tissues, cell blocks, and smears of cultured cells using 3H- or 35S-labeled DNA and 35S-labeled RNA probes. In order to use elevated stringencies in the hybridization and wash steps, tissue sections and cells are covalently bonded to silanated glass slides without their subsequent loss from the slides. Routine hematoxylin and eosin or Romanovsky's stains enable the identification of the cells detected by in situ hybridization. HIV-infected neuroblastoma and lymphoid cell lines, lymph nodes, bone marrow, kidney, as well as brain tissue from patients with acquired immunodeficiency syndrome (AIDS) and AIDS-related complex are used to demonstrate the generality of the procedure. The standardized method described widens the ease and applicability of in situ hybridization in the investigation of pathologic tissues with the use of diverse specimens and probes.

High-resolution structure of an HIV zinc fingerlike domain via a new NMR-based distance geometry approach.

A new method is described for determining molecular structures from NMR data. The approach utilizes 2D NOESY back-calculations to generate simulated spectra for structures obtained from distance geometry (DG) computations. Comparison of experimental and back-calculated spectra, including analysis of cross-peak buildup and auto-peak decay with increasing mixing time, provides a quantitative measure of the consistence between the experimental data and generated structures and allows for use of tighter interproton distance constraints. For the first time, the "goodness" of the generated structures is evaluated on the basis of their consistence with the actual experimental data rather than on the basis of consistence with other generated structures. This method is applied to the structure determination of an 18-residue peptide with an amino acid sequence comprising the first zinc fingerlike domain from the gag protein p55 of HIV. This is the first structure determination to atomic resolution for a retroviral zinc fingerlike complex. The peptide [Zn(p55F1)] exhibits a novel folding pattern that includes type I and type II NH-S tight turns and is stabilized both by coordination of the three Cys and one His residues to zinc and by extensive internal hydrogen bonding. The backbone folding is significantly different from that of a "classical" DNA-binding zinc finger. Residues C(1)-F(2)-N(3)-C(4)-G(5)-K(6) fold in a manner virtually identical with the folding observed by X-ray crystallography for related residues in the iron domain of rubredoxin; superposition of all main-chain and Cys side-chain atoms of residues C(1)-K(6) of Zn(p55F1) onto residues C(6)-Y(11) and C(39)-V(44) of rubredoxin gives RMSDs of 0.46 and 0.35 A, respectively. The side chains of conservatively substituted Phe and Ile residues implicated in genomic RNA recognition form a hydrophobic patch on the peptide surface.

Pathogenesis of malignant lymphomas in intravenous drug-abuser, HIV-infected patients.

To study the pathogenesis of malignant lymphomas (ML) in intravenous drug-abuser HIV-infected patients, we analyzed 19 cases of reactive lymphadenopathy (LAS) and 10 cases of ML. Clonality and differences in characteristics of these lymphoproliferative disorders were investigated by immunohistochemical and Ig and TCR gene rearrangement analyses. Rearrangements at the c-myc locus and presence of HIV and EBV viral genomes were also investigated. Four out of the five non-Hodgkin's lymphomas (NHL) analyzed were high-grade extranodal ML and were found to derive from precursor B cells. Monoclonal cell expansions were also detected in 2 cases of LAS. These cell expansions also consisted of precursor B cells. HIV genome was not detected in any of the samples tested and was therefore considered not to be involved as an etiological agent in these lymphoproliferative disorders. EBV genome was present in a clonal episomal form in the five Hodgkin's disease (HD) specimens tested. This finding suggested that a clonal cell population harboring the EBV viral genome must be present in HDs, pointing to a possible etiological relationship between EBV and HD in HIV-infected patients.