Post-mortem toxicology in the diagnosis of sudden death in young and middle-aged victims.

OBJECTIVE: We aimed to investigate the impact of the toxicological results found in cases of sudden death (SD) and to correlate the clinical, autopsy and genetic findings with the toxicology results. MATERIALS AND METHODS: Consecutive SD in people aged between 16 and 50 years with medico-legal autopsies and toxicology studies were included over a 3-year period. The comparison between the toxicological data and demographic characteristics, clinical circumstances, autopsy, and genetic results were taken into account. RESULTS: 101 cases were finally included. They were predominately males (84%) and the mean age was 39.8 years. 52 (51.5%) cases had positive toxicological findings and in 25 cases (24.8%), toxic compounds were considered the first cause of death. Ethanol was the most frequently identified agent (69%), following by licit drugs (56%) and drugs of abuse (39%). Cases with positive toxicology were younger than those with negative results (37.9±9.1 vs. 41.9±7.8; p=0.02). Patients with more than 3 comorbidities showed an association with positive toxicological results (n=14 vs. n=3; p=0.017). The genetic study was performed in 70 (69.3%) SD cases. We identified pathogenic or likely pathogenic variants in 17.1% cases and uncertain significance variants in 42.8% cases. 58% of these variants were probably related to the cause of death. CONCLUSIONS: A large fraction of SD victims had positive toxicological findings and a quarter of deaths were directly caused by toxic substances. The identification of the factors that trigger SD provides a good approach to contribute in avoiding future episodes.

A widespread bacterial phenazine forms S-conjugates with biogenic thiols and crosslinks proteins.

Phenazines are redox-active compounds produced by a range of bacteria, including many pathogens. Endowed with various biological activities, these ubiquitous N-heterocycles are well known for their ability to generate reactive oxygen species by redox cycling. Phenazines may lead to an irreversible depletion of glutathione, but a detailed mechanism has remained elusive. Furthermore, it is not understood why phenazines have so many protein targets and cause protein misfolding as well as their aggregation. Here we report the discovery of unprecedented conjugates (panphenazines A, B) of panthetheine and phenazine-1-carboxylic (PCA) acid from a Kitasatospora sp., which prompted us to investigate their biogenesis. We found that PCA reacts with diverse biogenic thiols under radical-forming conditions, which provides a plausible model for irreversible glutathione depletion. To evaluate the scope of the reaction in cells we designed biotin and rhodamine conjugates for protein labelling and examined their covalent fusion with model proteins (ketosynthase, carbonic anhydrase III, albumin). Our results reveal important, yet overlooked biological roles of phenazines and show for the first time their function in protein conjugation and crosslinking.

Comparison of magnetic resonance enteroclysis and capsule endoscopy with balloon-assisted enteroscopy in patients with obscure gastrointestinal bleeding.

BACKGROUND AND STUDY AIMS: New modalities are available for visualization of the small bowel in patients with possible obscure gastrointestinal bleeding (OGIB), but their performance requires further comparison. This study compared the diagnostic yield of magnetic resonance enteroclysis (MRE) and capsule endoscopy in patients with OGIB, using balloon-assisted enteroscopy (BAE) as the reference standard. PATIENTS AND METHODS: Consecutive consenting patients who were referred for evaluation of OGIB were prospectively included. Patients underwent MRE followed by capsule endoscopy and BAE. Patients with high grade stenosis at MRE did not undergo capsule endoscopy. The reference standard was BAE findings in visualized small-bowel segments and expert panel consensus for segments not visualized during BAE. RESULTS: Over a period of 26 months, 38 patients were included (20 female [53 %]; mean age 58 years, range 28 - 75 years). Four patients (11 %) did not undergo capsule endoscopy due to high grade small-bowel stenosis at MRE (n = 3; 8 %) or timing issues (n = 1; 3 %). Capsule endoscopy was non-diagnostic in one patient. The reference standard identified abnormal findings in 20 patients (53 %). MRE had sensitivity, specificity, and positive and negative likelihood ratios of 21 %, 100 %, infinity, and 0.79, respectively. The corresponding values for capsule endoscopy were 61 %, 85 %, 4.1, and 0.46. The reference standard and capsule endoscopy did not differ in percent positive findings (P = 0.34), but MRE differed significantly from the reference BAE (P < 0.001). Capsule endoscopy was superior to MRE for detecting abnormalities (P = 0.0015). CONCLUSION: Capsule endoscopy performed better than MRE in the detection of small-bowel abnormality in patients with OGIB. MRE may be considered as an alternative for the initial examination in patients with clinical suspicion of small-bowel stenosis.

Diagnóstico prenatal de 2 casos de arco aórtico derecho / Prenatal diagnosis of 2 cases of right-sided aortic arch

Las anomalías del arco aórtico derecho se adscriben a un grupo de malformaciones poco frecuentes y escasamente descritas en la bibliografía en su forma prenatal; sin embargo, no es infrecuente hallarlas como causa de patología respiratoria o digestiva (refractarias a tratamiento) en pacientes adultos e incluso como procesos vasculares severos con morbimortalidad elevada. La relación de los grandes vasos con la tráquea en el mediastino alto, en el estudio fetal, permite un diagnóstico relativamente sencillo, cuando se contempla su posibilidad diagnóstica

The use of the three vessels and trachea view, described by Yagel in 2001, allows diagnosis of aortic arch malformations, which can help to guide fetal chromosome study and identify patients who will benefit from lifelong follow-up. Right-sided aortic arch anomalies belong to a group of infrequent malformations. Few cases of prenatal forms have been described in the literature. Nevertheless, it is not infrequent to find these anomalies as the cause of respiratory or digestive disease (refractory to treatment) in adult patients and even as severe vascular processes with high morbidity and mortality. The position of the great vessels in relation to the trachea at the level of the superior mediastinum in fetal study allows a relatively simple diagnosis, especially when the diagnostic possibilities are considered

Cell surface display of a lysosomal enzyme for extracellular gene-directed enzyme prodrug therapy.

Prodrug conversion is a promising approach to cytotoxic gene therapy if an efficient transfer of the generated drug to adjacent cells can be achieved. To maximize the efficacy of this strategy we sought to develop a system that is based on a human enzyme, acts extracellularly yet in close vicinity of the transduced cell and can be used with multiple prodrugs. Results obtained with a secreted version of human beta-glucuronidase suggested that this enzyme could be a suitable candidate, although a more stringent retention of the enzyme at the site of the producer cell, such as its attachment to the cell surface, would be desirable. Here, we show that the fusion of the transmembrane domain of the human PDGF receptor to a C-terminally truncated form of human beta-glucuronidase results in its surface accumulation at high steady-state levels. Using a doxorubicin prodrug, we demonstrate that this GDEPT system produces a strong bystander effect and has potent antitumor activity in vivo.

High-resolution mapping and recombination interval analysis of mouse chromosome 17.

Analysis of homologous recombination in eukaryotes has shown that some meiotic crossing-over occurs preferentially at specific genomic sites of limited physical distance called recombinational hotspots. In the mouse, recombinational hotspots have only been defined in the major histocompatibility complex (MHC) on chromosome (Chr) 17. In an attempt to examine whether hotspots are unique to the MHC or are present throughout the genome, high-resolution linkage maps of Chr 17 based on five backcrosses involving different inbred strains have been generated. These maps separate many markers that were previously shown at the same map position and allow a detailed analysis of recombination patterns across Chr 17. Corresponding recombination intervals in these maps have been compared for the identification of intervals with very little or no recombination in certain genetic crosses and considerable recombination in other genetic crosses. This approach has been termed Recombination Interval Analysis. Possible haplotype-dependent non-MHC hotspots, as well as previously identified MHC hotspots, have been detected by interval analysis.

Cognitive manifestations of Huntington disease in relation to genetic structure and clinical onset.

OBJECTIVE: To examine the cognitive manifestations of Huntington disease (HD) with respect to age, clinical onset, progression, and genetic analyses. DESIGN: Case series of people with HD or at risk (AR) for HD. SETTING: Movement disorders and medical genetics clinics. PARTICIPANTS: Volunteer sample of 50 patients with HD and 127 AR adults. MEASURES: Neuropsychological evaluation was conducted with multiple measures of cognitive function (intelligence, memory, attention, executive, spatial, language), strength, manual speed/dexterity, somatosensory function, and mood. Quantitative molecular genetic analysis by means of polymerase chain reaction was conducted on 31 patients with HD and 86 AR subjects. RESULTS: In clinical HD, cognitive impairment correlated with number of years affected but not age at onset. The linear regression had a negative intercept, suggesting impaired cognitive function by the time of onset. In AR gene carriers, lower cognitive performance correlated with more trinucleotide repeats. In clinical HD, trinucleotide repeats interacted with disease chronicity such that more repeats were associated with worse performance over time; the overall effect of this was small compared with the effect of disease chronicity alone. Except for one AR subject, mood state was not associated with cognitive performance in either patients with HD or AR subjects. CONCLUSIONS: Cognitive decline appears to start before clinical onset of HD and is correlated with the number of trinucleotide repeats. Subsequent cognitive decline is primarily a function of number of years affected, although there is evidence that the presence of more trinucleotide repeats is associated with faster deterioration.

Effect of the mouse scid mutation on meiotic recombination.

The goal of this study was to determine the effect of the mouse severe combined immunodeficiency (scid) mutation on the rate of meiotic recombination, by standard backcross linkage analysis. For this purpose, we examined four crosses that involved F1 hybrid animals heterozygous for the strain C57BL/6 and BALB/c genomes. In one set of reciprocal crosses, F1 animals were homozygous scid/scid, and in a second set of reciprocal crosses, F1 mice were homozygous wild-type (+/+) at the scid locus. Backcross progeny were typed for recombination between selected genetic markers on mouse Chromosomes (Chrs) 1, 4, 6, 7, 9, 15, and 17. Although some differences in recombination were observed over some intervals, the expression of the SCID phenotype did not appear to have a major or consistent effect on meiotic recombination.

Ea recombinational hot spot in the mouse major histocompatibility complex maps to the fourth intron of the Ea gene.

The majority of recombination events detected within the mouse major histocompatibility complex (MHC) fall into regions of limited physical distance known as hot spots of meiotic recombination. The hot spot associated with the Ea gene appears to be active only in the presence of the p allele carried by the intra-MHC recombinant strain BIO.F(13R). To study the frequency, regulation, and haplotype specificity of recombination at the Ea hot spot, progeny from three different backcrosses involving BIO.F(13R) were screened for recombination events across the MHC using DNA microsatellite markers. Screening of a total of 750 backcross progeny permitted the identification of seven recombinants within the Ea gene. Using restriction site polymorphisms, and sequence-based nucleotide polymorphisms, the recombination breakpoints in all seven Ea recombinants were mapped to two adjacent segments of 71 bp and 346 bp in intron 4 of the Ea gene.

Analysis of recombinational hot spots associated with the p haplotype of the mouse MHC.

Most of the recombination events detected within the major histocompatibility complex (MHC) of the mouse fall into areas of limited physical size that have been designated recombinational hot spots. One of these hot spots, associated with the Ea gene, appears to be active only in the presence of the p haplotype of the MHC. To study the regulation of the Ea recombinational hot spot and its haplotype specificity, a high-resolution comparative map of the MHC and adjacent regions was completed in four different backcrosses carrying the p haplotype. This mapping study utilized a total of 29 PCR-based molecular markers, including 7 newly developed markers spanning the region between Pim1 and D17Mit11 on Chromosome 17. The analysis of a total of 1093 backcross animals: (1) revealed that the presence of the p haplotype of the MHC is not sufficient to induce recombination at the Ea hot spot in a dominant manner, and (2) resulted in the definition of a new intra-MHC recombinational hot spot between the Tnfb and the H2-D genes.

[The role of radiophotography in tuberculosis control programs in Poland]. / Miejsce badan radiofotograficznych w programie zwalczania gruzlicy w Polsce.

The role of mass radiophotography in Poland in the years 1985-1898 is presented basing on routine data from Antituberculous Centers and Radiophotographic Units. Mass radiophotography detects approximately 30% of new registered pulmonary tuberculosis cases. In the analysed period the number of radiophotographic examinations systematically fell. Also the percentage of the population that was screened using this method decreased, as well as, although to a lesser state, the percentage of new detected cases of pulmonary tuberculosis. A significant decrease in usage of mass radiophotography equipment was also seen. The economical cost of such examination increased. The role and place of mass radiophotography in tuberculosis control programs in Poland is discussed by the authors. It seems that first contact physicians will have the most pronounced role in early diagnosis of pulmonary tuberculosis. Also more emphasis should be placed on bacteriological diagnosis of tuberculosis.

Effects of diuretic therapy and exercise-related arrhythmias in systemic hypertension.

The effect of aerobic exercise on cardiac arrhythmias, plasma catecholamines, potassium and magnesium in patients with systemic hypertension was assessed. Twenty patients (age 54 +/- 8 years) with uncomplicated hypertension underwent exercise treadmill testing twice while receiving placebo and twice while receiving hydrochlorothiazide 100 mg daily. Blood samples for electrolytes and catecholamines were obtained at rest, at peak exercise and 10 minutes after exercise. There were no substantial differences comparing the first to the second placebo phase or the first to the second treatment period. As expected, hydrochlorothiazide treatment caused a significant decrease in serum potassium (4.00 +/- 0.44 to 3.32 +/- 0.49 mEq/liter, p less than 0.001). Serum magnesium did not change with treatment. Serum potassium, serum magnesium and plasma catecholamines increased significantly with exercise. No rebound hypokalemia occurred during recovery. Occasional ventricular premature contractions were noted at rest during all phases of the study, with only a slight increase in frequency during exercise. Couplets were noted only rarely. No difference in the frequency or complexity of arrhythmias was noted between placebo and treatment periods. Diuretic therapy or diuretic-induced hypokalemia has no profound effect on cardiac arrhythmias during or after exercise in patients with uncomplicated systemic hypertension.

Flecainide: electrophysiologic and antiarrhythmic properties in refractory ventricular tachycardia.

Twenty-two patients with coronary artery disease and spontaneous ventricular tachycardia (VT) or ventricular fibrillation (VF) underwent intracardiac electrophysiologic evaluation and, when possible, ambulatory monitoring before and after therapy with flecainide (mean dose 418 +/- 87 mg [mean +/- standard deviation]). An average of 4 antiarrhythmic agents were used and were unsuccessful before therapy with flecainide was begun. During 64 +/- 16 hours of control Holter monitoring in 16 patients, all had 1 or more salvos of VT, as well as ventricular premature complexes (VPCs). Programmed stimulation during the control period induced VT in 17 of 22 patients. After flecainide therapy, Holter monitoring showed elimination of all forms of VT in all but 1 patient, as well as significant reduction of paired VPCs by 95% (p less than 0.03) and single VPCs by 70% (p less than 0.005). Electrophysiologic study during flecainide therapy showed significant increases in AH, HV, PR, QRS and QTc intervals, and the ventricular effective refractory period. Programmed stimulation in 17 patients taking flecainide, with a mean plasma level of 1,075 +/- 521 ng/ml, showed ablation of inducible VT in only 2 patients, a worsening in 5 and continued VT inducibility in 10. Adverse effects that required drug withdrawal were infrequent and encountered in patients who received higher drug levels: 1 patient with congestive heart failure and 1 with severe sinus bradycardia. Thus, although flecainide suppresses complex ventricular arrhythmias on Holter recordings, it rarely alters the response to programmed stimulation. Caution is recommended in its use for recurrent sustained VT or VF and in the interpretation of electrophysiologic studies until the predictive value of programmed stimulation with flecainide therapy is established.

Daily living group: focus on transition from hospital to community.

A group (Daily Living Group) that prepares patients for discharge from a psychiatric hospital was formulated to provide patients with information on activities essential for their integration into the outside community. The information included the use of support systems in the hospital setting to aid in bridging the gap between hospital and community, as well as emphasis on the patients' leisure interests, community resources, and environment outside the hospital. The group then gave the patients the opportunity to apply what they learned, that is, practical experience in working through their problems. Patients with an investment in making behavioral changes responded well, but those with no investment lowered the morale of the group when coerced into attending.