HIV-1 infection of in vitro cultured human monocytes: early events and influence of anti HIV-1 antibodies

Summary To characterize the role of the humoral immune response on HIV-1 infection of monocytes and macrophages (Ms) we examined the susceptibility of in vitro cultured monocyte/Ms to various HIV-1 isolates and the influence of heterologous and particularly autologous anti HIV-1 sera on this infection. Depending on the period of in vitro cultivation and the virus isolate used different patterns of susceptibility were detected. One week old monocyte/Ms were highly susceptible to HIV-1 infection, in contrast to monocyte/Ms cultured 4 weeks. The infection by virus isolated immediately after seroconversion lead to persistent infection with high level of antigen production in contrast to infection by homologous virus isolated later. MAb against the V3-IIIB loop and sCD4 inhibited the infection of monocyte/Ms in a dose dependent manner, indicating that infection requires binding to CD4 and that post binding events may be common to the infection of lymphocytes. Anti HIV-1 sera showed neutralizing activity against heterologous and even autologous escape virus. This finding, together with the observation that monocytes and Ms are infected in vivo, suggests that protection against HIV-1 infection of monocytes and Ms in vivo may not be obtainable by the humoral immune response alone.     

An HLA study in 74 Danish haemochromatosis patients and in 21 of their families

HLA-A and -B alleles in 74 Danish patients and 21 homozygous relatives with idiopathic haemochromatosis (IH) were compared with those in a sample of 1719 chromosomes from healthy Danish control subjects. The following alleles occurred with higher frequencies in IH compared to controls: A3: 53.6% vs. 15.1% (Pc less than 0.001); B7: 33.1% vs. 15.6% (Pc less than 0.001); B14: 6.9% vs. 3.0% (Pc greater than 0.05); B38: 5% vs. 0.9% (Pc greater than 0.05); B47: 4.0% vs. 0.4% (Pc greater than 0.05). Pedigree analyses disclosed 19 different haplotypes in IH subjects, compared to 286 haplotypes in controls. The following haplotypes occurred with higher frequency in IH compared to controls: A3,B5: 10.3% vs. 0.3% (Pc less than 0.001); A3,B7: 25.6% vs. 6.6% (Pc = 0.001); A3,B14: 3.4% vs. 0.6% (Pc greater than 0.05); A3,B47: 6.9% vs. 0.2% (Pc greater than 0.05). The major IH marker HLA-A3 was found in 56% of the haplotypes. The patterns of HLA-alleles associated with IH in Denmark show similarities to those in Central Europe, Australia, USA and Canada, being A3,B7 dominated and those in Central Sweden, England and Ireland, being A3,B14 dominated.     

Genome-scale reconstruction of the Saccharomyces cerevisiae metabolic network

The metabolic network in the yeast Saccharomyces cerevisiae was reconstructed using currently available genomic, biochemical, and physiological information. The metabolic reactions were compartmentalized between the cytosol and the mitochondria, and transport steps between the compartments and the environment were included. A total of 708 structural open reading frames (ORFs) were accounted for in the reconstructed network, corresponding to 1035 metabolic reactions. Further, 140 reactions were included on the basis of biochemical evidence resulting in a genome-scale reconstructed metabolic network containing 1175 metabolic reactions and 584 metabolites. The number of gene functions included in the reconstructed network corresponds to approximately 16% of all characterized ORFs in S. cerevisiae. Using the reconstructed network, the metabolic capabilities of S. cerevisiae were calculated and compared with Escherichia coli. The reconstructed metabolic network is the first comprehensive network for a eukaryotic organism, and it may be used as the basis for in silico analysis of phenotypic functions.     

Geographical and temporal conservation of antibody recognition of Plasmodium falciparum variant surface antigens

The slow acquisition of protection against Plasmodium falciparum malaria probably reflects the extensive diversity of important antigens. The variant surface antigens (VSA) that mediate parasite adhesion to a range of host molecules are regarded as important targets of acquired protective immunity, but their diversity makes them questionable vaccine candidates. We determined levels of VSA-specific immunoglobulin G (IgG) in human plasma collected at four geographically distant and epidemiologically distinct localities with specificity for VSA expressed by P. falciparum isolates from three African countries. Plasma levels of VSA-specific IgG recognizing individual parasite isolates depended on the transmission intensity at the site of plasma collection but were largely independent of the geographical origin of the parasites. The total repertoire of immunologically distinct VSA thus appears to be finite and geographically conserved, most likely due to functional constraints. Furthermore, plasma samples frequently had high IgG reactivity to VSA expressed by parasites isolated more than 10 years later, showing that the repertoire is also temporally stable. Parasites from patients with severe malaria expressed VSA (VSASM) that were better recognized by plasma IgG than VSA expressed by other parasites, but importantly, VSASM-type antigens also appeared to show substantial antigenic homogeneity. Our finding that the repertoire of immunologically distinct VSA in general, and in particular that of VSASM, is geographically and temporally conserved raises hopes for the feasibility of developing VSA-based vaccines specifically designed to accelerate naturally acquired immunity, thereby enhancing protection against severe and life-threatening P. falciparum malaria.     

Goblet cells in the normal adult human larynx--studies on morphology, distribution and density

From 12 clinically and macroscopically normal larynges from adult persons all the mucosa was prepared and stained with PAS-alcian blue to study the morphology, distribution, and density of the goblet cells. In each larynx goblet cells were counted in 600 fields of 0.01768 mm2 mucosal surface, distributed on 18, 18 and 24 localities in the subglottis, glottis with the sinus of Morgagni, and supraglottis respectively. The goblet cells form a continuous pattern, comprising the entire subglottis, the anterior commissure, the sinus of Morgagni, the false vocal cords, vestibule of the larynx, and reaching to the cranial part of the laryngeal surface of the epiglottis. Another continuous, but goblet cell-free area extended from a couple of mm posterior to the anterior commissure, posteriorad on the cranial surface of the vocal cords, ary regions, aryepiglottic fold, the edge of the epiglottis, and 4-5 mm of the laryngeal surface of the epiglottic top, epiglottic vallecula, piriform recess, and the postcricoid region. Between the pseudostratified, ciliated columnar epithelium with goblet cells and the goblet cell-free stratified squamous epithelium there is a transitional epithelium in which the goblet cells alter from the 40 micron tall goblet cells characteristic of the respiratory tract epithelium to being quite flattened in order to disappear completely in the stratified squamous epithelium. The goblet cell density is significantly lower in the subglottis, viz. 125 cells per field, than in the glottis with the sinus of Morgagni and supraglottis, where the median density is 166 and 161 cells respectively per field. A possible correlation between the influence of the respiratory air upon the density of goblet cells and the complex anatomy of the larynx is discussed.     

Prevalence of antibodies against heat-stable antigens from Helicobacter pylori in patients with dyspeptic symptoms and normal persons.

Heat-stable antigens from Helicobacter pylori were investigated for the detection of serum IgG, IgA and IgM antibodies against H. pylori by an ELISA technique. Antibody titers against H. pylori were measured in 167 dyspeptic patients, of whom 96 were H. pylori positive confirmed by culture or microscopy, and in 482 controls (0-98 years). Increased IgG antibody titers were found significantly more often in dyspeptic patients with active chronic gastritis than in patients with normal morphology, as well as in H. pylori-positive patients as compared to H. pylori-negative patients, independent of the endoscopic findings. The heat-stable antigens were compared with acid glycine-extracted antigens and a high degree of concordance was found in the results obtained with the two antigen preparations. The differences in the IgA antibody titers against H. pylori between H. pylori-positive and H. pylori-negative dyspeptic patients were significant and may be useful to confirm a borderline IgG result. No differences were found in IgM antibody titer between H. pylori-positive and -negative patients. The greatest age-dependent increase in IgG and IgA antibody titers was found in children, and if a lower cut-off level is used for children than for adults, as has been proposed, the proportion of people with increased antibody titers against H. pylori would be almost constant from the age of between five and 10 years until the time between 61 and 80 years. Comparison of H. pylori IgG antibodies with IgG antibodies against Campylobacter jejuni and total antibodies against cytomegalovirus (CMV) showed a greater similarity between H. pylori and C. jejuni (R = 0.51) than between H. pylori and CMV (R = 0.22). This may possibly be caused by cross-reactions between H. pylori and C. jejuni. The H. pylori heat-stabile antigen seems not to be very different from other crude H. pylori antigens like acid glycine-extracted antigens, but purification and characterization of the antigens are needed to improve antibody assays.     

Fatal familial cholestatic syndrome in Greenland Eskimo children

Summary We report the first detailed study of hepatic morphlogy in 28 biopsies from 16 Greenland Eskimo children with fatal familial cholestatic syndrome. The changes were categorized as early, intermediate and late. In the early stage, until 5 months of age, changes were restricted to zone 3, consisting of cholestasis and rosette formation without fibrosis. In the intermediate stage, from 5 to 14 months, cholestasis persisted and rosette formation increased, both with further extension into zone 2. Perisinusoidal fibrosis developed, first in zone 3 and later in zone 1. The late stage, from 17 to 60 months, showed a further increase in cholestasis and rosette formation, and fibrosis of zones 3 and 1 in nearly all biopsies. Portal to portal and portal to central fibrosis was evident with resulting cirrhosis in 2 of 7 patients. The morphological features can be summarized as pure cholestasis with prominent rosette formation followed by zone 3 fibrosis, zone 1 fibrosis, and, cirrhosis. Other characteristics are the virtual absence of inflammation and the lack of anatomical abnormalities such as paucity of bile ducts. The changes and their progression resemble those of Byler disease. Clinical and biochemical features are also largely similar, except for the presence of thrombocytosis in many of the Eskimo patients.     

Androgen receptor YAC transgenic mice carrying CAG 45 alleles show trinucleotide repeat instability

X-linked spinal and bulbar muscular atrophy (SBMA) is caused by a CAG repeat expansion in the first exon of the androgen receptor (AR) gene. Disease-associated alleles (37-66 CAGs) change in length when transmitted from parents to offspring, with a significantly greater tendency to shift size when inherited paternally. As transgenic mice carrying human AR cDNAs with 45 and 66 CAG repeats do not display repeat instability, we attempted to model trinucleotide repeat instability by generating transgenic mice with yeast artificial chromosomes (YACs) carrying AR CAG repeat expansions in their genomic context. Studies of independent lines of AR YAC transgenic mice with CAG 45 alleles reveal intergenerational instability at an overall rate of approximately 10%. We also find that the 45 CAG repeat tracts are significantly more unstable with maternal transmission and as the transmitting mother ages. Of all the CAG/CTG repeat transgenic mice produced to date the AR YAC CAG 45 mice are unstable with the smallest trinucleotide repeat mutations, suggesting that the length threshold for repeat instability in the mouse may be lowered by including the appropriate flanking human DNA sequences. By sequence-tagged site content analysis and long range mapping we determined that one unstable transgenic line has integrated an approximately 70 kb segment of the AR locus due to fragmentation of the AR YAC. Identification of the cis - acting elements that permit CAG tract instability and the trans -acting factors that modulate repeat instability in the AR YAC CAG 45 mice may provide insights into the molecular basis of trinucleotide repeat instability in humans.      

'Vanishing embryo syndrome' in IVF/ICSI

BACKGROUND: In a Danish population-based cohort study assessing the risk of cerebral palsy in children born after IVF, we made some interesting observations regarding 'vanishing co-embryos'. METHODS and RESULTS: All live-born children born in Denmark from 1 January 1995 to 31 December 2000 were included in this analysis. The children conceived by IVF/ICSI (9444) were identified through the IVF Register, the children conceived without IVF/ICSI (395 025) were identified through The Danish Medical Birth Register. Main outcome measure was the incidence of cerebral palsy. Within the IVF/ICSI children we found indications of an increased risk of cerebral palsy in those children resulting from pregnancies, where the number of embryos transferred was higher than the number of children born. CONCLUSIONS: The association between vanishing embryo syndrome and incidence of cerebral palsy following IVF requires further investigation in larger, adequately powered, studies.     

Severe hypertension with cerebral symptoms treated with furosemide, fractionated diazoxide or dihydralazine. Danish Multicenter Study

Emergency treatment of acute, severe hypertension defined as diastolic blood pressure (DBP) greater than or equal to 135 mmHg combined with cerebral symptoms was prospectively monitored in a randomized multicenter study including 64 patients. Treatment was divided into two periods. In the first hour the patients were observed in the supine position after being given 40 mg furosemide intravenously. If DBP remained greater than 125 mmHg (n = 52), the patients were put on fractionated diazoxide administered intravenously (n = 28) or dihydralazine administered intramuscularly (n = 24). Blood pressure (BP) decreased with diazoxide from an average of 241/149 mmHg to 180/111 mmHg after 5 hours and with dihydralazine from 237/149 to 161/101 mmHg. The inter-individual BP response varied considerably. A clear and identical regression in neurological symptoms was observed on both drug regimens. No new neurological symptoms were seen to develop. It is concluded that a gradual fall in BP can be obtained after fractionated dosage of diazoxide (i.v.) as well as after dihydralazine (i.m.). The indication of acute parenteral therapy compared to less aggressive oral treatment is discussed.