Apoptosis of CD8+ T cells is mediated by macrophages through interaction of HIV gp120 with chemokine receptor CXCR4

CD8-positive T cells are thought to play an important role in the control of infection by human immunodeficiency virus (HIV) as a result of their cytotoxic activity and by releasing soluble factors. In AIDS patients, the absolute number of CD8+ T lymphocytes is decreased in peripheral blood and their turnover rate is increased, suggesting that there is more cell renewal and cell death occurring. Anti-retroviral therapy raises CD8+ T-cell counts in HIV-infected patients. Here we report that the death rate of CD8+ T cells by apoptosis increased markedly during HIV infection of peripheral blood mononuclear cells in vitro. Apoptosis is induced in a dose-dependent manner by recombinant envelope glycoprotein gp120 from HIV strain X4, or by stromal-derived factor-1 (SDF-1), the physiological ligand of the chemokine receptor CXCR4. Apoptosis is mediated by the interaction between tumour-necrosis factor-alpha bound to the membrane of macrophages (mbTNF) and a receptor on CD8+ T cells (TNF-receptor II, or TNFRII). The expression of both of these cell-surface proteins is upregulated by HIV infection or by treatment with recombinant gp120 or SDF-1. Apoptosis of CD8+ T cells isolated from HIV-infected patients is also mediated by macrophages through the interaction between mbTNF and TNFRII. These results indicate that the increased turnover of CD8+ T cells in HIV-infected subjects is mediated by the HIV envelope protein through the CXCR4 chemokine receptor.

Senescence-associated barley NAC (NAM, ATAF1,2, CUC) transcription factor interacts with radical-induced cell death 1 through a disordered regulatory domain

Senescence in plants involves massive nutrient relocation and age-related cell death. Characterization of the molecular components, such as transcription factors (TFs), involved in these processes is required to understand senescence. We found that HvNAC005 and HvNAC013 of the plant-specific NAC (NAM, ATAF1,2, CUC) TF family are up-regulated during senescence in barley (Hordeum vulgare). Both HvNAC005 and HvNAC013 bound the conserved NAC DNA target sequence. Computational and biophysical analyses showed that both proteins are intrinsically disordered in their large C-terminal domains, which are transcription regulatory domains (TRDs) in many NAC TFs. Using motif searches and interaction studies in yeast we identified an evolutionarily conserved sequence, the LP motif, in the TRD of HvNAC013. This motif was sufficient for transcriptional activity. In contrast, HvNAC005 did not function as a transcriptional activator suggesting that an involvement of HvNAC013 and HvNAC005 in senescence will be different. HvNAC013 interacted with barley radical-induced cell death 1 (RCD1) via the very C-terminal part of its TRD, outside of the region containing the LP motif. No significant secondary structure was induced in the HvNAC013 TRD upon interaction with RCD1. RCD1 also interacted with regions dominated by intrinsic disorder in TFs of the MYB and basic helix-loop-helix families. We propose that RCD1 is a regulatory protein capable of interacting with many different TFs by exploiting their intrinsic disorder. In addition, we present the first structural characterization of NAC C-terminal domains and relate intrinsic disorder and sequence motifs to activity and protein-protein interactions.

Chronic toxic encephalopathy in solvent-exposed painters in Denmark 1976-1980: clinical cases and social consequences after a 5-year follow-up

On the basis of previous investigations from occupational medicine, neurology, and neuropyschology, a retrospective evaluation was made of 21 painters in whom chronic toxic encephalopathy following exposure to organic solvents had been diagnosed during a stay in the Neurology Department of Gentofte Hospital, Copenhagen, in the period 1976-1980. All the painters had given up their jobs for this reason. The assumption of a causal relationship between the exposure and the intellectual impairment was supported by a possible dose-effect relationship. The chronic toxic symptoms had considerable social consequences. Five years later, ten had not gotten other jobs. The lack of working ability was correlated to advancing age, increasing exposure, and increasing intellectual impairment. According to the results of the study, conditions at work places ought to be changed in such a way that harmful exposure can be prevented in the future.

Neurotoxic effects of organic solvents in exposed workers: an occupational, neuropsychological, and neurological investigation

Ninety-eight workers, 65 exposed to organic solvents and 33 unexposed, were examined in order to assess possible neurotoxic signs and symptoms related to solvent exposure. The study group, who were selected according to the type of exposure in a given work process, had been exposed to various types of solvents. The groups were comparable in regard to age, the history of brain traumas and other neurological diseases, and alcohol consumption. The exposed workers had more symptoms of intellectual impairment, poorer performances in psychological tests, and more often signs of cerebral asthenopia. Symptoms and signs of peripheral neuropathy were not significantly increased. Solvent exposure and neurotoxic signs and symptoms were mildly correlated in the study group. Such dose-effect correlations have previously been proved only in a few epidemiological studies. This warrants reevaluation of the risk of developing toxic encephalopathy during prolonged occupational exposure to solvents.

Neurotoxic effects of organic solvents in exposed workers: two controlled follow-up studies after 5.5 and 10.6 years

The findings of acute and/or chronic central and peripheral neurotoxic effects of organic solvents in workers from a previous controlled cross-sectional study (65 exposed and 33 unexposed) were re-assessed to ascertain whether the neurotoxic symptoms and signs had become chronic. These follow-ups were performed 5.5 years later by occupational medical and clinical neurological examination (59 exposed and 30 unexposed) and again 10.6 years later by a mailed questionnaire (53 exposed and 30 unexposed). Both follow-ups revealed more acute neurotoxic symptoms in the exposed workers than in the unexposed workers, but fewer than previously, and indeed, the current exposure to solvents had been reduced. However, at both follow-ups, the exposed workers showed significantly more symptoms of chronic encephalopathy, in particular, memory and concentration impairment. These latter symptoms had also significantly worsened in the workers who were still being exposed, while they were presently unchanged in the previously exposed workers who had been free of exposure for 6.6 years at the latter follow-up. On the other hand, symptoms of chronic encephalopathy had not appeared in the unexposed group. Among workers, both still and previously exposed, there were also social consequences in the form of occupational disqualification. According to the findings, long-term occupational exposure to organic solvents in concentrations that are not unusual at workplaces may lead to development of chronic neurotoxic symptoms.

Evidence for the separate molecular expression of four distinct polymorphic Ia epitopes on cells of DR4 homozygous individuals

The monoclonal antibodies 109d6 and IVD12 reacted with separate polymorphic Ia epitopes in immunofluorescent studies. Using a panel of lymphoblastoid B cell lines, antibody 109d6 reacted with all HLA-DR4 or DR7 positive lines in a pattern resembling the MT3 specificity recognized by human alloantisera. The antibody IVD12 reacted with all HLA-DR4 and two of three DR5 positive B cell lines suggesting that it recognized a specificity similar to MB3. The intensity of fluorescence was greater on DR5(+) cell lines than on DR4(+) cell lines relative to the amount of a nonpolymorphic Ia determinant. Among 45 unrelated control individuals reactivity with antibody 109d6 was correlated most closely with (r = 0.724) but not identical in occurrence to the MT3 specificity. Cocapping experiments demonstrated that the 109d6 epitope and the IVD12 epitope were present on independently redistributed cell surface molecules of DR4 homozygous lymphoblastoid cell lines. Furthermore, the DR4 alloantigens detected by an absorbed polyclonal human alloserum were similarly identified on molecules that were independent from those bearing either the 109d6 epitope or the IVD12 epitope. Taken together, these data indicate the existence of at least four distinct, serologically defined Ia molecular species.

Pontiac fever at a sewage treatment plant in the food industry

BACKGROUND AND OBJECTIVES

During a hot and humid summer period workers became ill with fever and flu-like symptoms after repairing a decanter for sludge concentration at a sewage treatment plant. The work took place over a period of 10 days in a small closed room, while another decanter was in operation and was consequently emitting aerosol to the environment, to which the workers were exposed. The aim of this study was to determine the cause of this outbreak of febrile illness so that additional cases could be prevented.

METHODS

All 5 patients were seen and examined in the Department of Occupational Medicine. Furthermore 2 of the workers had recurrent illness and were examined during hospitalization. As Pontiac fever (nonpneumonic legionellosis) was suspected, antibodies to legionellae were measured in blood samples. After positive antibody titers to Legionella pneumophila were found, samples of the sludge were collected for legionellae culture.

RESULTS AND CONCLUSIONS

The clinical picture agreed with that described for Pontiac fever, and positive antibody titers to L. pneumophila serogroup 1 were found in blood from all 5 patients. L. pneumophila serogroup 1 was cultured in high amounts from sludge from the decanter. It was concluded that the fever was caused by L. pneumophila emitted to the environment by the uncovered decanter. Procedures for preventing new cases were established.

Mapping a gene for 46,XY gonadal dysgenesis by linkage analysis

46,XY gonadal dysgenesis was transmitted as an autosomal-dominant trait in a large family with multiple affected members. Expressivity of the trait was highly variable, ranging from pure to partial gonadal dysgenesis associated with normal female genitalia or sexual ambiguity, to mild hypospadias in otherwise normal males. The phenotypic features of this trait appeared to be confined to the genitourinary system. Multipoint parametric analysis using markers D5S664, D5S633, and D5D2102 yielded an LOD score of 4.47, assuming sex-limited, autosomal-dominant inheritance with a penetrance of 0.6. Because mutation in testis-determining genes leads to gonadal dysgenesis in 46,XY individuals, we postulate that the gene mapped by this study normally plays a role in gonadal differentiation.

Skin irritation and exposure to diisocyanates in orthopedic nurses working with soft casts

BACKGROUND

Diisocyanates are widely used in industry, for example at hospitals as a constituent of Scotch Cast soft casts (3M, Glostrup, Denmark). They are a cause of occupational asthma and have been described as causing cutaneous problems both as irritants and as sensitizers.

OBJECTIVE

The sensitizing potential of diisocyanates has previously only sporadically been described, predominantly in case reports. Therefore, we conducted this study to investigate eventual work-related skin sensitization to diisocyanates in a regularly exposed population.

METHODS

The nursing staff of an orthopaedic outpatient clinic, consisting of 10 persons, were interviewed and subjected to patch testing using 5 types of diisocyanates and the TRUE Test (ECDRG Standard Series) to elucidate possible other type IV allergies with similar symptoms. Patch test results were evaluated according to the guidelines of the International Contact Dermatitis Group.

RESULTS

We found no relationship between exposure time and severity of symptoms. Symptoms were mild, consisting of redness, itching, or both, lasting about 30 minutes. There was no suggestion that they result in any chronic skin problems. One nurse presented a doubtful reaction towards diaminophenylmethane (MDA) and isophorene diisocyanate (IPDI). Nine persons had no reactions to the 5 diisocyanates used in the patch test. Positive reactions were seen to nickel (4/10), thiomersal (2/10), and perfume mix (1/10).

CONCLUSION

Our observations suggest that diisocyanates are primarily irritants rather than sensitizers in the professional setting studied. The skin symptoms of irritation were all mild and temporary.

Smoking habits and attitudes to smoking 2001 among hospital staff at a Danish hospital--comparison with a similar study 1999

BACKGROUND

Smoking is the main preventable cause of lifestyle-related diseases and smoking cessation interventions have shown to be cost-effective. It is important to know the smoking habits and attitudes towards smoking among the hospital staff because of the impact the staff have on the patients. Two studies were conducted to attain this information.

METHODS

This study analyzes the results of a survey conducted in the summer of 2001 and compares them to a similar study conducted in 1999. 970 anonymous questionnaires were distributed in 2001.

RESULTS

The number of smokers among the staff has significantly decreased from 33% to 26% over the 2-year period. Those who do still smoke are less willing to quit and are reluctant to accept help to stop smoking. Fewer are bothered by passive smoking now compared to 1999 and approximately 2/3 of the responders do not find it acceptable to implement sanctions against the members of staff who break the prohibition.

CONCLUSION

It is worth providing resources to smoking cessation intervention. The intensive preventive work carried out at the hospital may have resulted in significantly fewer smokers among the staff which again facilitate the staff's effort to help the patients stop smoking.

Reaction time of industrial workers exposed to organic solvents: relationship to degree of exposure and psychological performance

Auditory reaction time (RT) was examined on a day free from work and on a working day in 54 workers exposed to organic solvents and in 28 unexposed workers. Medical and occupational history was recorded and neurological examination and psychological testing carried out to establish quantitative parameters of exposure and cerebral function. There was a wider 95% range of the RT in the exposed group compared to the control group on the working day and a tendency in the same direction on the day free from work. There was no difference in the means of the RT, or within the groups between the examinations on the two days. The increased RT 95% range is interpreted as indicating an impaired ability in the exposed workers to maintain their attention during the experimental period, owing to chronic exposure of organic solvents. RT measurements did not correlate with exposure or psychological performance. RT would seem to be a means of measuring subclinical effects of exposure to organic solvents.

The effect of indomethacin 1% ophthalmic suspension in preventing surgically induced miosis at extracapsular cataract surgery

27 patients who underwent extracapsular cataract surgery (ECCE) were randomized in two groups with 12 patients in Group 1 treated with standard preoperative dilation regime and 15 patients in Group 2 receiving in addition Indomethacin 1% ophthalmic solution, one drop the evening before surgery and one drop 45 minutes before surgery. Horizontal pupillary diameter measurements were taken at the beginning of the operation before retrobulbar anesthesia, before capsulotomy, and before lens implantation. A significant decrease in pupillary diameter and area was seen in both groups (P greater than 0.001; t-test) from before capsulotomy until before lens implantation. No significant change was seen from start until before capsulotomy. A significant lesser pupillary constriction expressed as mean calculated pupillary area differences from start until before lens implantation was seen in Group 2 treated with indomethacin (17.70 +/- 6.68(mm)2), than in Group 1 without indomethacin (29.06 +/- 8.82(mm)2); (P greater than 0.05; t-test). It is concluded that local use preoperatively of the antiprostaglandin drug indomethacin in 1% ophthalmic solution (Indocid, MSD) is able to reduce surgically induced miosis during ECCE, thereby facilitating the operative procedure and probably minimizing complications.

Polymorphism of the HLA-D region in American blacks. A DR3 haplotype generated by recombination

The polymorphism of HLA class II molecules in man is particularly evident when comparisons between population groups are made. This study describes a DR3 haplotype commonly present in the American black population. Unlike the Northern European population in which almost all DR3 individuals are DQw2, approximately 50% of DR3-positive American blacks express a serologically undefined DQ allelic product. DNA restriction fragment analysis with the use of several unrelated individuals and an informative family has allowed us to identify unique DQ alpha- and beta-fragments associated with the DR3, DQw- haplotype. Based on fragment size, the DQ alpha genes of the DR3, DQw- and DRw8, DQw- haplotypes are similar as are the DQ beta genes of DR3, DQw-; DRw8, DQw-; and DR4, DQw- haplotypes. In addition, a DX beta gene polymorphism has been identified which is associated with some DR3 haplotypes including the American black DR3, DQw- haplotype. cDNA sequence analysis has revealed a DQw2-like alpha gene and a DQ beta gene which is similar to that previously described for a DR4, DQw- haplotype. It is postulated that recombination between DQ alpha and DQ beta genes and between the DQ and DX subregions has generated the various DR3 haplotypes and has played an important role in creating diversity in the HLA-D region.

Polymorphism of the HLA-D region in American blacks. A DR3 haplotype generated by recombination

The polymorphism of HLA class II molecules in man is particularly evident when comparisons between population groups are made. This study describes a DR3 haplotype commonly present in the American black population. Unlike the Northern European population in which almost all DR3 individuals are DQw2, approximately 50% of DR3-positive American blacks express a serologically undefined DQ allelic product. DNA restriction fragment analysis with the use of several unrelated individuals and an informative family has allowed us to identify unique DQ alpha- and beta-fragments associated with the DR3, DQw- haplotype. Based on fragment size, the DQ alpha genes of the DR3, DQw- and DRw8, DQw- haplotypes are similar as are the DQ beta genes of DR3, DQw-; DRw8, DQw-; and DR4, DQw- haplotypes. In addition, a DX beta gene polymorphism has been identified which is associated with some DR3 haplotypes including the American black DR3, DQw- haplotype. cDNA sequence analysis has revealed a DQw2-like alpha gene and a DQ beta gene which is similar to that previously described for a DR4, DQw- haplotype. It is postulated that recombination between DQ alpha and DQ beta genes and between the DQ and DX subregions has generated the various DR3 haplotypes and has played an important role in creating diversity in the HLA-D region.

Zero-discharge of nutrients and water in a willow dominated constructed wetland

A novel constructed wetland system has been developed to treat sewage, evaporate water and recycle nutrients from single households at sites where effluent standards are stringent and soil infiltration is not possible. Main attributes of the willow wastewater cleaning facilities are that the systems have zero discharge, the willows evapotranspire the water, and nutrients can be recycled via the willow biomass produced in the system. The willow wastewater cleaning facilities generally consist of c. 1.5 m deep high-density polyethylene-lined basins filled with soil and planted with clones of willow (Salix viminalis L.). The surface area of the systems depends on the amount and quality of the sewage to be treated and the local annual rainfall. For a single household the area needed typically is between 200-300 m2. Settled sewage is dispersed underground into the bed under pressure. When correctly dimensioned, the willow will--on an annual basis--evapotranspire all water from the sewage and rain falling onto the system, and take up all nutrients and heavy metals from the sewage. The stems of the willows are harvested on a regular basis to remove nutrients and heavy metals and to stimulate the growth of the willows. Initial experiences from full-scale systems in Denmark show promising results.