Pegylated interferon-alpha for the treatment of sexually transmitted acute hepatitis C in HIV-infected individuals

BACKGROUND: Sexually transmitted acute hepatitis C among HIV-positive homosexual men has been noted as an emerging epidemic. METHODS: Forty-seven patients with mainly sexually acquired, acute hepatitis C were enrolled in this prospective, multicentre trial, and 36 of these patients were treated within the acute phase of hepatitis C infection with pegylated interferon (peg-IFN) therapy. RESULTS: Early treatment resulted in sustained virological response in 61% of patients. Peg-IFN alone showed similar treatment response rates and lower incidence of anaemia compared with peg-IFN+ribavirin combination therapy. Higher treatment response rates were observed in patients treated over 48 weeks compared with 24 weeks. CONCLUSIONS: Treatment of hepatitis C in HIV-positive individuals in the acute phase of infection leads to high rates of sustained virological response. Optimal time and mode of therapy have yet to be defined.     

Time-trends in method-specific suicide rates compared with the availability of specific compounds. The Danish experience

Restriction of means for suicide is an important part of suicide preventive strategies in different countries. All suicides in Denmark between 1970 and 2000 were examined with regard to method used for suicide. Overall suicide mortality and method-specific suicide mortality was compared with official information about availability of medical compounds (barbiturates, benzodiazepines, analgesics, antidepressants) and carbon monoxide in vehicle exhaust and household gas. Restrictions on the availability of carbon monoxide, barbiturates and dextropropoxyphen was associated with a decline in the number of suicides by self-poisoning with these compounds. Restricted access occurred concomittantly with a 55% decrease in suicide rate.     

Clade extinction appears to balance species diversification in sister lineages of Afro-Oriental passerine birds

Recent analyses suggest that the number of species in a clade often increases rapidly at first, but that diversification subsequently slows, apparently as species fill ecological space. Support for diversity dependence comes largely from the failure of species richness to increase with clade age in some analyses of contemporary diversity. However, clades chosen for analysis generally are named taxa and thus are not selected at random. To avoid this potential bias, we analyzed the numbers of species and estimated ages of 150 pairs of sister clades established by dispersal of ancestral species between the Oriental and African biogeographic regions. The observed positive exponential relationship between clade size and age suggests that species diversify within clades without apparent limit. If this were true, the pattern of accumulation of sister-clade pairs with increasing age would be consistent with the random decline and extinction of entire clades, maintaining an overall balance in species richness. This “pulse” model of diversification is consistent with the fossil record of most groups and reconciles conflicting evidence concerning diversity dependence of clade growth.The close relationship between local species richness and characteristics of the physical environment supports the existence of ecological constraints on species coexistence mediated through competition and other interactions (1–3), although historical influences on diversity sometimes parallel gradients in the physical environment (4–6). If species richness were limited as ecological space filled, one would expect the net rate of species production to slow and the number of species in a clade to level off as species richness approached ecological constraints.Evidence for such “diversity-dependent diversification” consists mostly of (i) nonrandom concentrations of branch points (speciation events) toward the origin of a clade (7–12) and (ii) independence of the number of species and clade age in comparisons among clades (11–14). However, clades included in such analyses often are not randomly chosen. In particular, small clades may be ignored because they do not command interest, and large, older clades are often passed over because of incomplete sampling (15, 16). Moreover, most phylogenetic analyses of diversification include species in named higher taxa rather than clades that have diversified within particular regions.Further support for diversity limits comes from the fossil records of many higher taxa, which exhibit long-term stability in number of species (17–19). It is also clear that species and entire clades continually replace each other through time, and the dynamics of this process appear to include the decline and extinction of evolutionary groups as a component of the local and regional regulation of the number of coexisting species (20–25).We take advantage of the sister relationships of clades of passerine birds in two major biogeographic regions—tropical southern Asia [Oriental (OR)] and the continent of Africa [African (AF)]—to examine the independent diversification of sister clades of known stem ages, selected only because one of the ancestors had dispersed between the two continents at some time in the past. Movement of species between these regions occurred either over water across the Indian Ocean, possibly using island stepping-stones, or through the Arabian Peninsula during periods of suitable environment. Each dispersal event defines the origin of a pair of same-aged sister clades in the two regions.If each diversifying clade filled a certain part of ecological space to a carrying capacity for species, after which diversification slowed, the sizes of clades filling this space would level off over time (26). Furthermore, the number of species per sister clade, particularly among older clades that have filled ecological space, might be correlated between regions, with species richness reflecting the ecological space available to each of the sister lineages (27). Finally, for those dispersal events whose directionality can be inferred, the rate of diversification should be higher, leading to larger clade size compared between sister lineages, in the newly colonized region, which initially would have fewer close (and ecologically similar) relatives of the ancestral species.We include all species of passerine birds (Passeriformes) and, separately, species in nonpasserine orders, of small, terrestrial birds, in the Oriental and African biogeographic regions (SI Appendix, section S1). The passerine avifauna of these regions accumulated from several sources over most of the Cenozoic Era (28, 29), with an old Gondwanan clade of suboscine passerines diversifying in tropical Africa and southern Asia early in the Tertiary, followed by radiations of core corvoid and passerid oscine passerines out of Australia during the early to mid-Cenozoic, through Wallacea to southern Asia, or directly across the Indian Ocean to Africa (30, 31). Thus, the diversification of sister clades in the African and Oriental regions takes place against a background of an increasing number of lineages of modern passerine birds as a whole within the region. Nonpasserine orders of terrestrial birds are likely to have diversified earlier within these regions (32) and perhaps were replaced to some extent by the passerines.Characteristics of a sample of clades include the distribution of node ages and the relationship between clade size and stem age, as well as the distribution of clade sizes regardless of age, including the proportion of clades that contain a single species. Any process-based model of diversification should be judged by how well it reproduces these characteristics. We use these criteria to evaluate simulations in which we attempt to reconstruct the underlying diversification process.     

Magnesium substitution in acute ischaemic heart syndromes.

It has recently been suggested that intravenous infusion of magnesium may reduce mortality and the incidence of serious arrhythmias in patients with ischaemic heart disease and acute myocardial infarction. In the present double-blind, placebo-controlled study, 298 patients with suspected acute myocardial infarction were randomized to receive either intravenous magnesium chloride (80 mmol.24 h-1) or placebo. Infusions were started immediately after admission to the coronary care unit. One hundred and fifty patients received magnesium and 148 the placebo. Ischaemic heart disease was diagnosed in 244 patients. Acute myocardial infarction was observed among 83 patients in the magnesium group and 79 in the placebo group. Both treatment groups were comparable regarding sex, age, clinical status, previous cardiac disease and medication. Serum magnesium was significantly raised during magnesium infusion compared to placebo (P less than 0.01). Fatal events were only observed among patients with myocardial infarction, but neither the in-hospital mortality (magnesium: 12.1%; placebo 10.1%) nor the mortality after a follow-up period of 245 days (median observation time) was affected by magnesium substitution. Magnesium infusion was accompanied by a significantly increased incidence of atrioventricular conduction disturbances. The results suggest that patients suffering from acute ischaemic heart syndromes do not benefit from intravenous magnesium supplementation.