Hospitalizations for acetaminophen overdose: a Canadian population-based study from 1995 to 2004

<p>Abstract</p> <p>Background</p> <p>Acetaminophen overdose (AO) is the most common cause of acute liver failure. We examined temporal trends and sociodemographic risk factors for AO in a large Canadian health region.</p> <p>Methods</p> <p>1,543 patients hospitalized for AO in the Calgary Health Region (population ~1.1 million) between 1995 and 2004 were identified using administrative data.</p> <p>Results</p> <p>The age/sex-adjusted hospitalization rate decreased by 41% from 19.6 per 100,000 population in 1995 to 12.1 per 100,000 in 2004 (<it>P </it>< 0.0005). This decline was greater in females than males (46% vs. 29%). Whereas rates fell 46% in individuals under 50 years, a 50% increase was seen in those ≥ 50 years. Hospitalization rates for intentional overdoses fell from 16.6 per 100,000 in 1995 to 8.6 per 100,000 in 2004 (2004 vs. 1995: rate ratio [RR] 0.49; <it>P </it>< 0.0005). Accidental overdoses decreased between 1995 and 2002, but increased to above baseline levels by 2004 (2004 vs. 1995: RR 1.24;<it>P </it>< 0.0005). Risk factors for AO included female sex (RR 2.19; <it>P </it>< 0.0005), Aboriginal status (RR 4.04; <it>P </it>< 0.0005), and receipt of social assistance (RR 5.15; <it>P </it>< 0.0005).</p> <p>Conclusion</p> <p>Hospitalization rates for AO, particularly intentional ingestions, have fallen in our Canadian health region between 1995 and 2004. Young patients, especially females, Aboriginals, and recipients of social assistance, are at highest risk.</p

Surviving crack: a qualitative study of the strategies and tactics developed by Brazilian users to deal with the risks associated with the drug

<p>Abstract</p> <p>Background</p> <p>Due to marginalization, trafficking violence, conflicts with the police and organic and social psychological problems associated with the drug, crack is one of the most devastating drugs currently in use. However, there is evidence that some users manage to stay alive and active while using crack cocaine for many years, despite the numerous adversities and risks involved with this behavior. In this context, the aim of the present study was to identify the strategies and tactics developed by crack users to deal with the risks associated with the culture of use by examining the survival strategies employed by long-term users.</p> <p>Method</p> <p>A qualitative research method was used involving semi-structured, in-depth interviews. Twenty-eight crack users fulfilling a pre-defined enrollment criterion were interviewed. This criterion was defined as the long-term use of crack (i.e., at least four years). The sample was selected using information provided by key informants and distributed across eight different supply chains. The interviews were literally transcribed and analyzed via content analysis techniques using NVivo-8 software.</p> <p>Results</p> <p>There was diversity in the sample with regard to economic and education levels. The average duration of crack use was 11.5 years. Respondents believed that the greatest risks of crack dependence were related to the drug's psychological effects (e.g., cravings and transient paranoid symptoms) and those arising from its illegality (e.g., clashes with the police and trafficking). Protection strategies focused on the control of the psychological effects, primarily through the consumption of alcohol and marijuana. To address the illegality of the drug, strategies were developed to deal with dealers and the police; these strategies were considered crucial for survival.</p> <p>Conclusions</p> <p>The strategies developed by the respondents focused on trying to protect themselves. They proved generally effective, though they involved risks of triggering additional problems (e.g., other dependencies) in the long term.</p

Correction to the Amino Acid Sequence of the α Chain of Human Haptoglobin

The previously published amino acid sequence of the α chain of human haptoglobin must be corrected to include a half-cystine residue at position 73. </jats:p

The resemblance of the combination of human haptoglobin and double hemoglobin molecules to an antigen–antibody reaction

Human haptoglobin (Hp) combines with hemoglobin double molecules (Hb∙Hb) isolated from an inbred strain of mice, DBA/2J. When low ionic strength solutions of the two proteins are mixed, precipitates form. The extent of precipitation is dependent upon the ratios of the two proteins in a manner similar to that seen in a classical antigen–antibody precipitin reaction. In a more alkaline buffer of higher ionic strength, complexes form which remain soluble and may be resolved as a series of bands by acrylamide disc electrophoresis. The relative concentration of each band within the series depends upon the input ratios of Hp and Hb∙Hb. These results indicate that human haptoglobin is bivalent and combines with hemoglobin in a fashion analogous to the combination of an antibody with an antigen. </jats:p

Studies on the Interchain Disulfides of Human Haptoglobins

Cyanogen bromide cleavages have been performed on the three major haptoglobin types in order to study the interchain disulfide linkages. Fragments (PC III's) were isolated which contained an intact haptoglobin α chain joined to a fragment of the haptoglobin β chain. Peptictryptic digests of the PC III fragment from Hp 1-1 confirmed the presence of the 21α-21α disulfide peptide and revealed the presence of disulfide peptides which contained half-cysteines 35α, 69α, 73α, and the half-cysteine present in the β chain fragment. The PC III fragments from the polymetric haptoglobins (2-1 and 2-2) were found to exist as a series of polymers. This indicated that the half-cysteine at position 21 in haptoglobin α1, which after the partial duplication results in half-cysteines at position 21 and 80 in α2, is responsible for the formation of the haptoglobin polymers. </jats:p

The influence of haptoglobin on the reactivity of the –SH groups of hemoglobin

The rate of reaction of the β93 sulfhydryl of hemoglobin with iodoacetamide and 2,2′-, and 4,4′- dithiodipyridine is much slower when the hemoglobin is bound by haptoglobin than when it is free. However, these sulfhydryl reagents will react with the haemoglobin–haptoglobin complex, and the reaction of the complex with iodoacetamide is still at position β93. The results suggest that haptoglobin might induce a conformation change on oxyhemoglobin which is similar to that occurring upon deoxygenation. </jats:p

Unmasking of histone amino groups in chromatin at high pH.

The reactivity of the amino groups of histones in chromatin towards acetic anhydride was determined as a function of pH. In the pH range 7-10 the vast majority of amino groups in all five histones are buried. However, at higher pH values some of the histone amino groups become exposed, and the higher the lysine:arginine ratio for the histone the greater was the degree of unmasking observed. At pH 11.8 histone I appears to be completely dissociated, histones IIB1 and IIb2 have approx. 55% of the amino groups unmasked, and histones III and IV have approx. 25% of the amino groups unmasked

The Half-Molecule of Haptoglobin: Studies on the Product Obtained by the Selective Cleavage of a Haptoglobin Disulfide

A disulfide of haptoglobin 1-1 has been selectively cleaved using sodium sulfite and p-chloro-mercurisulfonate. The reaction product (half-haptoglobin) could be separated from haptoglobin by gel electrophoresis in urea or sodium dodecyl sulfate, and its molecular weight was one-half that of native haptoglobin 1-1. When the sulfite cleavage reaction was performed on haptoglobin 2-2 the haptoglobin polymers were broken down. Isolation of the S-sulfocysteine-containing peptide revealed that the disulfide bond broken in the formation of half-haptoglobin was the 21α-21α disulfide. This conclusion was confirmed by analysis of the cyanogen bromide fragments from half-haptoglobin and by a performic acid diagonal analysis of peptic peptides obtained from half-haptoglobin. </jats:p