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At least 433 records · Page 24Linked to original sources
PubMed2005

Out-of-hospital cardiac deaths in adolescents and young adults in the United States, 1989 to 1998.

BACKGROUND: Out-of-hospital cardiac death (OHCD), often occurring suddenly and unexpectedly, is a major public health problem. The purpose of this study is to assess the epidemiologic pattern and secular trend of OHCD in adolescents and young adults aged 15-34 years in the United States. METHODS: United States national vital statistics mortality data from 1989 to 1998 were analyzed. OHCD was defined as death that occurred either at a pre-transport location, or in the emergency room, or was classified as "dead on arrival" in the emergency room, with an underlying cause of death as a cardiac disease (ICD-9 codes 390-398, 402, 404-429, 745, or 746). RESULTS: Of the 48,573 cardiac deaths occurring during 1989 to 1998, 31,827 (66%) were out of hospital. Of all OHCD victims from 1989 to 1998, 70% were men, and 76% were aged 25-34 years. The leading underlying causes of OHCD were coronary heart disease (29%), cardiomyopathy (18%), and arrhythmias (14%). The OHCD rates (per million population) were twice as high in men as in women (57.0 vs. 26.7 in 1997 and 1998), in African Americans as in whites (84.9 vs. 35.9 in 1997 and 1998), and increased with age. From 1989-1990 to 1997-1998, the age-adjusted OHCD death rates increased in both men (11%) and women (33%), and in African Americans (11%) and whites (19%). CONCLUSIONS: Although cardiac death remains rare in U.S. adolescents and young adults, the increased trend in OHCD rates in this age group warrants further investigation of etiology and prevention strategies.

Adolescent↗
PubMed2000

An association between sudden infant death syndrome (SIDS) and Helicobacter pylori infection.

BACKGROUND: Helicobacter pylori has recently been detected in the stomach and trachea of cases of sudden infant death syndrome (SIDS) and proposed as a cause of SIDS. AIMS: To establish the incidence of H pylori in the stomach, trachea, and lung of cases of SIDS and controls. METHODS: Stomach, trachea, and lung tissues from 32 cases of SIDS and eight control cases were examined retrospectively. Diagnosis of SIDS was based on established criteria. Controls were defined by death within 1 year of age and an identifiable cause of death. Tissues were examined histologically for the presence of bacteria. Extracted DNA from these tissues was tested for H pylori ureC and cagA sequences by nested polymerase chain reaction and amplicons detected by enzyme linked immunosorbent assay (ELISA). The cut off for each ELISA for each of the tissue types was taken as the mean optical density plus two times the standard deviation of a range of negative controls. RESULTS: Ages of SIDS cases ranged from 2 to 28 weeks. Ages of controls ranged from 3 to 44 weeks. For the ureC gene, 25 SIDS cases were positive in one or more tissues compared with one of the controls. For the cagA gene, 25 SIDS cases were positive in one or more tissues compared with one of the controls. CONCLUSIONS: There is a highly significant association between H pylori ureC and cagA genes in the stomach, trachea, and lung of cases of SIDS when compared with controls.

DNA, Bacterial↗
PubMed2000

Spatial distribution of cannibalism mortalities in commercial laying hens.

The distribution of cannibalism cases in a flock of 19,776 Babcock White Leghorns was monitored from 21 to 54 wk of age. The hens were kept in a single-floor house consisting of four banks of two-deck stair-step cages. Each of the 4,944 cages held four hens at a density of 152 cm(2) (60 inches(2)) per hen. Each cage was assigned a number from 1 to 4,944, and each dead bird was tagged according to its cage of origin. Dead birds were collected daily, kept in a freezer, and necropsied weekly. Farm personnel routinely transferred a live hen from an end cage to a cage where a mortality had occurred. The cause of death, age, cage number, and cage location were recorded for each dead hen. Of the 1,173 hens that died during the study period, 253 (21.6%) died from egg peritonitis, 184 (15.7%) from hypocalcemia, 167 (14.1%) from cannibalism, 164 (14%) from neoplastic disease, and the rest from various other causes. Cannibalism cases were analyzed statistically for clustering. Cannibalism was defined as death from tissue trauma and hemorrhage inflicted by cage mates. A spatial analysis showed that cannibalism is not a random event but one that occurs in clusters. The incidence of cannibalism was also found to be significantly higher on the top rows of cages as compared with the bottom rows.

Age Factors↗
PubMed1996

Extracellular deposition of beta-amyloid upon p53-dependent neuronal cell death in transgenic mice.

The finding that intracellular expression of the beta-amyloid protein (Abeta) under a neuron-specific promoter led progressively to degeneration and death of neurons in the brains of transgenic mice provides a unique opportunity to utilize this animal model to both understand the mechanism that underlies neuronal cell death and define the complexity of events which may ensue. We observed a correlation between Abeta accumulation in selective neurons and activation of p53, a protein that has been implicated in the induction of apoptosis. Histological and immunohistochemical evaluations of adjacent brain sections suggest that expression of p53 is accompanied by nuclear DNA fragmentation. In certain regions with marked neuronal cell death, extracellular deposition of A(beta) became evident, together with the local activation of astrocytes. Interestingly, the neuritic structures underlying the Abeta deposits showed altered synaptophysin immunoreactivity and morphologic evidence for damage. This transgenic mouse model suggests that intracellular generation of the Abeta protein not only leads to the death of the neuron but may also functionally impair neighboring neurons as well. It further offers a mechanism whereby neuritic plaques may be derived.

Alzheimer Disease↗
PubMed2005

Temporal development of hippocampal cell death is dependent on tissue strain but not strain rate.

Deformation of brain tissue in response to mechanical loading of the head is the root-cause of traumatic brain injury (TBI). Even below ultimate failure limits, deformation activates pathophysiological cascades resulting in delayed cell death. Injury response of soft tissues, such as the chest and spinal cord, is dependent on the product of deformation and velocity, a parameter termed the viscous criterion. We set out to test if hippocampal cell death could be predicted by a similar combination of strain and strain rate and if the viscous criterion was valid for hippocampus. Quantitative prediction of the brain's biological response to mechanical stimuli is difficult to achieve in animal models of TBI, so we utilized an in vitro model of TBI based on hippocampal slice cultures. We quantified the temporal development of cell death after precisely controlled deformations for 30 combinations of strain (0.05-0.50) and strain rate (0.1-50s(-1)) relevant to TBI. Loading conditions for a subset of cultures were verified by analysis of high-speed video. Cell death was found to be significantly dependent on time-post injury, on strain magnitude, and to a lesser extent, on anatomical region by a repeated-measures, three-way ANOVA. The responses of the CA1 and CA3 regions of the hippocampus were not statistically different in contrast to some in vivo TBI studies. Surprisingly, cell death was not dependent on strain rate leading us to conclude that the viscous criterion is not a valid predictor for hippocampal tissue injury. Given the large data set and extensive combinations of biomechanical parameters, predictive mathematical functions relating independent variables (strain, region, and time post-injury) to the resultant cell death were defined. These functions can be used as tolerance criteria to equip finite element models of TBI with the added capability to predict biological consequences.

Analysis of Variance↗
PubMed2003

PLA2 activity is required for nuclear shrinkage in caspase-independent cell death.

Apoptosis is defined on the basis of morphological changes like nuclear fragmentation and chromatin condensation, which are dependent on caspases. Many forms of caspase-independent cell death have been reported, but the mechanisms are still poorly understood. We found that hypoxic cell death was independent of caspases and was associated with significant nuclear shrinkage. Neither Bcl-2 nor Apaf-1 deficiency prevented hypoxic nuclear shrinkage. To understand the molecular mechanism of the nuclear shrinkage, we developed an in vitro system using permeabilized cells, which allowed us to purify a novel member of the phospholipase A2 (PLA2) family that induced nuclear shrinkage. Purified PLA2 induced nuclear shrinkage in our permeabilized cell system. PLA2 inhibitors prevented hypoxic nuclear shrinkage in cells and cell death. Hypoxia caused elevation of PLA2 activity and translocation of intracellular PLA2s to the nucleus. Knockdown of the Ca2+-independent PLA2 delayed nuclear shrinkage and cell death. These results indicate that Ca2+-independent PLA2 is crucial for a caspase-independent cell death signaling pathway leading to nuclear shrinkage.

Active Transport, Cell Nucleus↗
PubMed2006

Lysosomal biogenesis and function is critical for necrotic cell death in Caenorhabditis elegans.

Necrotic cell death is defined by distinctive morphological characteristics that are displayed by dying cells (Walker, N.I., B.V. Harmon, G.C. Gobe, and J.F. Kerr. 1988. Methods Achiev. Exp. Pathol. 13:18-54). The cellular events that transpire during necrosis to generate these necrotic traits are poorly understood. Recent studies in the nematode Caenorhabditis elegans show that cytoplasmic acidification develops during necrosis and is required for cell death (Syntichaki, P., C. Samara, and N. Tavernarakis. 2005. Curr. Biol. 15:1249-1254). However, the origin of cytoplasmic acidification remains elusive. We show that the alkalization of endosomal and lysosomal compartments ameliorates necrotic cell death triggered by diverse stimuli. In addition, mutations in genes that result in altered lysosomal biogenesis and function markedly affect neuronal necrosis. We used a genetically encoded fluorescent marker to follow lysosome fate during neurodegeneration in vivo. Strikingly, we found that lysosomes fuse and localize exclusively around a swollen nucleus. In the advanced stages of cell death, the nucleus condenses and migrates toward the periphery of the cell, whereas green fluorescent protein-labeled lysosomal membranes fade, indicating lysosomal rupture. Our findings demonstrate a prominent role for lysosomes in cellular destruction during necrotic cell death, which is likely conserved in metazoans.

Animals↗
PubMed2000

Early and late deaths after elective end of therapies for childhood cancer in Italy.

The first cohort of subjects treated for cancer during childhood is now entering adulthood, and it is necessary to determine whether treatment has been sufficient to completely eradicate the neoplastic clone, and whether the cancer itself or treatment-related toxicity may have increased the risk of premature death. For these reasons, long-term survival and causes of death were evaluated in a cohort of subjects treated for childhood cancer who reached the elective end of therapy in continuous remission and were registered until 1992 in the Italian Registry of off-therapy subjects (OTR). The vital status of OTR subjects was ascertained in 1996 by a postal survey through census bureaux; for deceased subjects, the cause of death was defined and compared with the expected rates in the general population. At follow-up, out of 6402 eligible and evaluable subjects, 890 were found to have died; the estimated overall survival at 20 years was 80.7% (95% CI 79.3-82.1). Most of the patients (84.6%) died due to recurrence of the primary cancer, usually within the first 5 years after the OT. The cumulative incidence of death due to recurrence of the primary tumor was greater among subjects treated for solid tumor than among those treated for leukemia/lymphoma (p = 0.0001); in contrast, OT subjects after leukemia and lymphoma were more likely to die due to of medical complications of therapy (p < 0.02). Second cancers were the second most frequent cause of death, with a 12-fold risk compared with the general population; the figures were similar in the 2 cancer groups. Compared with the general population, OT subjects were 32 times more likely than same-age subjects to die. The SMR decreased to 6.1 when only non-cancer deaths were considered. Deaths due to external or avoidable causes occurred among survivors at a rate similar to that of the general population.

Adolescent↗
PubMed2002

Levels and causes of maternal mortality in Senegal.

OBJECTIVES: To report the findings of a direct, community-based, assessment of maternal mortality and medical causes of death using verbal autopsy in three unique cohorts in rural Senegal. METHODS: Methods from ongoing demographic surveillance systems. We obtained records of all deaths and births in women of age 15-49 over a period of 14 years in Niakhar, 10 years in Bandafassi and 13 years in Mlomp. Relatives of all women who died were interviewed using a standard questionnaire. Causes of death were assigned by three physicians independently. Maternal deaths were defined according to the ninth and tenth revisions of the International Classification of Diseases. RESULTS: The maternal mortality ratio was similar in Mlomp [436 per 100 000 live births (95% confidence interval 209-802)] and Niakhar [516 per 100 000 (413-636)] but significantly higher in the more remote area of Bandafassi [852 (587-1196)] [relative risk compared with Niakhar 1.6 (1.0-2.4)]. Two-thirds of the maternal deaths were from direct obstetric causes, haemorrhage being the most common. Abortion was rare. CONCLUSIONS: Demographic surveillance systems are useful tools for the measurement of maternal mortality provided special studies are carried out to arrive at the levels and causes of maternal death. The estimates of maternal mortality reported here are lower than those published by the WHO and UNICEF but remain extremely high, particularly in the very remote areas with very limited health infrastructure, where as many as one in 19 women may be expected to die as a consequence of childbirth.

Adolescent↗
PubMed2004

Effect of persistent moderate viremia on disease progression during HIV therapy.

OBJECTIVE: Although highly active antiretroviral therapy has been shown to lower plasma HIV-1 RNA in HIV infection, many patients do not reach the target goal of undetectable viremia. We evaluated whether risk of clinical progression varies by level of viral suppression achieved. DESIGN: Patients in the Collaborations in HIV Outcomes Research/United States cohort who maintained stable HIV-1 RNA levels of either <400, 400 to 20,000, or >20,000 copies/mL during a run-in period of at least 6 months were studied. Baseline was the first day after this period. METHODS: Proportional hazards models were used to quantify the relation between baseline HIV-1 RNA levels and risk of a new AIDS-defining diagnosis or death after adjusting for CD4 count, age, gender, ethnicity, study site, prior AIDS-defining diagnosis, and antiretroviral therapy history. RESULTS: Patients (N = 3010) were followed for up to 4.3 years after the 6-month run-in period, with 343 deaths or AIDS-defining diagnoses reported. The risk of a new AIDS-defining diagnosis or death was not significantly different in the 400 to 20,000- and <400-copies/mL groups (6% vs. 7%, hazard ratio [HR] = 1.0, 95% confidence interval [CI]: 0.7-1.4; P = 0.9) but was significantly higher in the >20,000-copies/mL group (26%, HR = 3.3, 95% CI: 2.5-4.4; P < 0.001 vs. the <400-copies/mL group). Median CD4 count changes during the first year of follow-up showed increases of 75 and 13 cells/mm for the <400- and 400 to 20,000-copies/mL groups, respectively, whereas the >20,000-copies/mL group had a decrease of 23 cells/mm. CONCLUSIONS: Patients who maintained baseline HIV-1 RNA levels of 400 to 20,000 copies/mL for at least 6 months preserved immunologic status and were no more likely to die or develop a new AIDS-defining diagnosis in the time frame studied than those with baseline levels <400 copies/mL. Patients with HIV-1 RNA levels >20,000 copies/mL at baseline had greater clinical and immunologic deterioration. These data suggest that maintenance of moderate viremia may confer clinical benefit not seen when viremia exceeds 20,000 copies/mL, and this should be taken into account when considering the risks and benefits of continuing failing therapy.

Adult↗
PubMed1999

Primary sclerosing cholangitis (PSC): clinical, laboratory and survival analysis in children and adults.

BACKGROUND: Primary sclerosing cholangitis (PSC) is an uncommon disorder, rarely diagnosed in children, moreover, data on its natural history and survival are still lacking. AIM: The study was undertaken to compare clinical, laboratory and survival rates in two series of PSC: one in a pediatric group (group A) and the other in an adult population (group B). METHODS: Group A included 9 patients (5 males, 4 females, mean age 10 yrs, range 7-15); group B included 28 patients (19 males, 9 females, mean age 32 years, range 19-60). The mean follow-up was 5.2 years in group A and 6.9 years in group B (range 1-14 years). ERCP and colonoscopy were performed in each case. Survival was analyzed using the Kaplan-Meier method. RESULTS: At presentation children showed significantly higher levels of IgG and AST compared to adults (p<0.05); moreover, interface hepatitis occurred in 50% of children and in 14.2% in adults (p=ns). During follow-up the following major events occurred: oesophageal bleeding (n=2) in group A; progressive liver failure (n=6), cholangiocarcinoma (n=3), colonic cancer (n=1) in group B. Liver transplantation (OLTx) was performed in 4 adults (one died after a retransplantation). No deaths were observed in children. The Kaplan-Meier curve in adults shows a 65% rate of survival at 10 years. CONCLUSIONS: The present findings on PSC suggest a more severe activity of the disease in children than in adults at presentation; nonetheless, the prognosis seems to be better in children than in adults. The Mayo score prognostic index does not predict the development of liver/colonic cancer. A poor outcome (defined as death or being listed for OLTx) only occurred in adults.

Adolescent↗
PubMed2000

Structure/Function analysis of p55 tumor necrosis factor receptor and fas-associated death domain. Effect on necrosis in L929sA cells.

Tumor necrosis factor (TNF) induces a typical apoptotic cell death program in various cell lines by interacting with the p55 tumor necrosis factor receptor (TNF-R55). In contrast, triggering of the fibrosarcoma cell line L929sA gives rise to characteristic cellular changes resulting in necrosis. The intracellular domain of TNF-R55 can be subdivided into two parts: a membrane-proximal domain (amino acids 202-325) and a C-terminal death domain (DD) (amino acids 326-413), which has been shown to be necessary and sufficient for apoptosis. Structure/function analysis of TNF-R55-mediated necrosis in L929sA cells demonstrated that initiation of necrotic cell death, as defined by swelling of the cells, rapid membrane permeabilization, absence of nuclear condensation, absence of DNA hypoploidy, and generation of mitochondrial reactive oxygen intermediates, is also confined to the DD. The striking synergistic effect of the caspase inhibitor benzyloxycarbonyl-Val-Ala-Asp(OMe)-fluoromethylketone on TNF-induced necrosis was also observed with receptors solely containing the DD. TNF-R55-mediated necrosis is not affected by the dominant negative deletion mutant of the Fas-associated death domain (FADD-(80-205)) that lacks the N-terminal death effector domain. Moreover, overexpression of FADD-(80-205) in L929sA is cytotoxic and insensitive to CrmA, while the cytotoxicity due to overexpression of the deletion mutant FADD-(1-111) lacking the DD is prevented by CrmA. These results demonstrate that the death domain of FADD can elicit an active necrotic cell death pathway.

Adaptor Proteins, Signal Transducing↗
PubMed1988

Care of sudden cardiac death survivors: the aberrant cardiac patients.

Caring for survivors of sudden cardiac death presents nursing with a challenge. Although many of these individuals' needs are similar to those of other patients with cardiac disease, some are different. This article investigates the role of the nurse in providing care for these unique clients. To increase the nurse's understanding, sudden cardiac death is defined, its pathophysiology described, and the current medical management detailed. The unique nursing care needs of these individuals are outlined and suggestions for nursing interventions are presented. By providing comprehensive physical and emotional support to these individuals, recovery and return to a high-quality life will be facilitated.

Death, Sudden↗
PubMed2002

Identification of patients at high risk for death and cardiac ischemic events after hospital discharge.

BACKGROUND: Patients with unstable angina (UA) and non-ST-elevation myocardial infarction (NSTEMI) remain at risk for death and cardiac ischemic events after being discharged from the hospital. METHODS: We examined whether the Thrombolysis In Myocardial Infarction (TIMI) risk score for UA/NSTEMI, ascertained at presentation in patients enrolled in the TIMI 11B and Efficacy and Safety of Subcutaneous Enoxaparin in Unstable Angina and Non-Q-Wave MI (ESSENCE) trials, could be used to identify patients at high risk for major cardiac events after hospital discharge. RESULTS: There were a total of 1218 major cardiac events, defined as death, nonfatal myocardial infarction, or urgent revascularization, by day 43. Of these events, 336 (28%) occurred in patients after they were discharged from the hospital. Use of the TIMI risk score for UA/NSTEMI revealed a progressive, statistically significant increase in the rate of events after leaving the hospital as the patients' baseline level of risk increased (P <.001 for chi(2) test for trend). For patients with a risk score of 5 to 7, treatment with enoxaparin during the acute phase was associated with an odds ratio of 0.51 (95% CI 0.29-0.91) for the occurrence of death and cardiac ischemic events after hospital discharge. CONCLUSIONS: More than one fourth of the major cardiac events that will occur in the first 6 weeks occur after discharge from the hospital. Stratification at presentation on the basis of the TIMI risk score for UA/NSTEMI can be used to identify patients at high risk for these events. Among patients at high-risk, acute-phase treatment with enoxaparin significantly reduces the risk of major cardiac events after leaving the hospital.

Angina, Unstable↗
PubMed1999

"Apoptotic" biochemical cascades in synaptic compartments: roles in adaptive plasticity and neurodegenerative disorders.

Apoptosis is a form of cell death historically defined by morphological and biochemical changes that occur in the cell body and nucleus. However, in contrast to nonneuronal cells in which apoptosis has been most intensively studied, neurons exhibit elaborate morphologies with synaptic connections often located at sites a great distance from the cell body. Signaling events occurring in synaptic terminals are believed to play important roles in either promoting (e.g., activation of glutamate receptors in postsynaptic spines) or preventing (e.g., activation of neurotrophic factors in presynaptic terminals) neuronal cell death in various physiological and pathological settings. We have found that apoptotic biochemical cascades can be activated locally in synaptic terminals and neurites and have shown that such cascades can result in local functional and morphological alterations and can also propagate to the cell body resulting in neuronal death. Prostate apoptosis response-4 production, caspase activation, loss of plasma membrane phospholipid asymmetry, mitochondrial dysfunction, and production of factors capable of inducing nuclear chromatin condensation and fragmentation can all occur locally in synaptic terminals in response to various stimuli. Activation of receptors for neurotrophic factors (e.g., basic fibroblast growth factor, secreted form of amyloid precursor protein alpha, and activity-dependent neurotrophic factor) and cytokines (e.g., tumor necrosis factor-alpha) in synaptic terminals can exert synaptoprotective actions that either can be transduced locally or may require signals to the nucleus and back. In addition to their roles in synaptic degeneration and neuron death, apoptotic cascades may play roles in synaptic plasticity. For example, we found that caspase activation can lead to proteolysis of certain glutamate receptor subunits and that this action of capases is correlated with reduced calcium responses to glutamate. We propose that apoptotic cascades function in a continuum in which low levels of activation play roles in adaptive responses to "stressors," whereas higher levels of activation mediate synaptic degeneration and cell death.

Animals↗
PubMed2000

Calcium antagonists for acute ischemic stroke.

BACKGROUND: The sudden loss of blood supply in ischemic stroke is associated with increased levels of calcium ions within neurones. Inhibiting this increase could protect neurones and is thought to reduce neurological impairment, disability and handicap after stroke. OBJECTIVES: The aim of this review is to determine whether calcium antagonists reduce the risk of death or dependency after acute ischemic stroke. The influence of different drugs, dosages, routes of administration, time intervals after stroke and trial design on the risk of poor outcome was investigated. SEARCH STRATEGY: Relevant trials were identified in the Specialised Register of Controlled Trials (last searched: March 1999). SELECTION CRITERIA: All truly randomised trials comparing a calcium antagonist with control in patients with acute ischaemic stroke were included. DATA COLLECTION AND ANALYSIS: Two authors assessed all trials and extracted the data. Poor outcome, defined as death or dependency in activities of daily living, was used as the main outcome. Analyses were, if possible, "intention-to-treat". MAIN RESULTS: 46 trials were identified of which 28 were included (7521 patients). No effect of calcium antagonists on poor outcome at the end of follow-up (OR 1.07, 95% CI 0.97/1.18), or on death at end of follow-up (OR 1.10, 95% CI 0.98/1.24) was found. Intravenous administration (i.v.) of calcium antagonists was associated with an increase in the number of patients with poor outcome compared to oral administration (indirect comparisons). Comparisons of different doses of nimodipine suggested that the highest doses were associated with poorer outcome. Administration within 12 hours of onset was associated with an increase in the proportion of patients with poor outcome, but this effect was largely due to the poor results associated with i.v. administration. A subgroup analysis on nimodipine (oral, 120 mg/day) started within 12 hours of stroke onset, did not show a beneficial effect. REVIEWER'S CONCLUSIONS: No evidence is available to justify the use of calcium antagonists in patients with acute ischaemic stroke.

Brain Ischemia↗
PubMedDate not supplied

A modern definition of death?

Throughout the ages, man has struggled to define exactly when death takes place. Common law dictated that the presence or absence of a heartbeat indicated whether or not a person was alive. In more recent years, this definition has changed to include brain activity as an important criterion. However, legislation resulting from this changed definition has only brought about more questions--such as what criteria shall be used to decide brain death.

Beginning of Human Life↗