An outbreak of Shigella sonnei infection associated with consumption of iceberg lettuce

OBJECTIVES: This study compared the relative strength of the associations of a set of structural (social, economic, and political) variables and a set of health services variables with state-level infant, neonatal, and postneonatal mortality. It also examined whether health services mediate the relationships between structural variables and state-level infant, neonatal, and postneonatal mortality. METHODS: With the state as the unit of analysis, data for all 50 states were analyzed by means of multiple regression. RESULTS: Structural variables accounted for substantially more variance in infant, neonatal, and postneonatal mortality than health services variables, and health services variables were more strongly related to infant mortality than to neonatal or postneonatal mortality. When health services variables were controlled, the strengths of the associations between the structural variables and infant, neonatal, and postneonatal mortality were reduced but remained statistically significant. CONCLUSIONS: A substantial portion of the variance in state-level infant mortality is accounted for by states' structural characteristics, which are partially mediated by health services.     

Ultraviolet exposure and the development of banal and atypical naevi--a cross-sectional study on Cura?ao and in The Netherlands

The atypical naevus is both a risk factor for and a precursor lesion of melanoma. Sunlight is known to be an important aetiological factor for melanoma. Whether solar exposure is also involved in the initiation of (atypical) naevi is an issue of current interest. We performed a cross-sectional study among 270 inhabitants in the cloudy Netherlands and 282 white Dutch immigrants of the tropical island Cura?ao to investigate whether solar exposure plays a role in the development of atypical naevi. All participants were interviewed and underwent total skin examination; banal melanocytic naevi and atypical naevi were counted. There was no significant difference in the mean number of melanocytic naevi > or = 2 mm or > or = 5 mm between Cura?ao and the Netherlands. Furthermore, there was no significant difference in the mean crude and age standardized prevalence of atypical naevi between the Netherlands and Cura?ao. In both groups individuals with atypical naevi had significantly more total naevi. Concerning the role of sun exposure in the development of naevi in the Netherlands, we found that the total naevus count had a significant association with cumulative sun exposure before the age of 12 as well as with two or more painful sunburns before the age of 12. In Cura?ao these relationships were not observed. In contrast, however, on Cura?ao the presence of atypical naevi showed an association (odds ratio = 2.6, 95% confidence interval 1.1-6.0) with the highest level of cumulative sun exposure and with painful sunburns before the age of 12 (odds ratio = 2.6, 95% confidence interval 1.2-5.5). In the Dutch group these associations were not significant. We hypothesize that in the development of banal naevi there is an association between the total number of naevi and sun exposure only at low exposure levels; however, after overstepping a critical threshold a further association between melanocytic naevi and sun exposure is lacking. Sunlight exposure before the age of 12 plays a complex role: only very high exposure levels seem to contribute to the development of atypical naevi.     

Effects of mass transfer and free convection on the unsteady mhd flow past a vertical porous plate with constant suction

Effects of free convection currents and mass transfer on the unsteady flow of an electrically conducting and viscous incompressible fluid past an infinite vertical porous plate subjected to uniform suction, in the presence of transverse magnetic field, have been studied taking into account that the external flow velocity varies periodically with time in magnitude but not in direction. The effect of the induced magnetic field has been neglected. Approximate solutions to the transient flow, the amplitude and the phase of the skin-friction and the rate of heat transfer have been derived. During the course of the discussion, the effects of the Grashoff number Gr, the modified Grashoff number Gc (depending on the concentration difference), the Schmidt number Sc, the Eckert number Ec, the magnetic field parameter M, and the frequency ω have been discussed.     

Accumulation of human immunodeficiency virus-specific cytotoxic T lymphocytes away from the predominant site of virus replication during primary infection

Down-regulation of the initial burst of viremia during primary human immunodeficiency virus (HIV) infection is thought to be mediated predominantly by HIV-specific CD8+ cytotoxic T lymphocytes (CTL). This response is associated with major perturbations in the T cell receptor (TCR) repertoire. To investigate the failure of the cellular immune response to adequately control viral spread and replication and to prevent establishment of HIV infection, changes in the TCR repertoire and in the distribution of virus-specific CTL between blood and lymph node were analyzed in three patients with primary infection. By the combined use of clonotype-specific polymerase chain reaction and analysis of the frequency of in vivo activated HIV-specific CTL, it was shown that HIV-specific CTL clones preferentially accumulated in blood as opposed to lymph node. Accumulation of HIV-specific CTL in blood occurred prior to effective down-regulation of virus replication in both blood and lymph node. These findings should provide new insights into how HIV, and possibly other viruses, elude the immune response of the host during primary infection.     

Introduction to the AFDC program. Aid to Families with Dependent Children

The NADYA Group, integrated in the Spanish Society of Parenteral and Enteral Nutrition (SENPE), and made up of professionals dedicated to Artificial Nutrition, and specifically, to Artificial Nutrition in the home, annually undertakes the task of collecting data on diagnosis, type of support, follow up characteristics, complications, and quality of life, of patients included in programs of at home artificial nutrition in Spain. In the Annual Register corresponding to 1994, 17 hospitality groups have participated, providing 369 patients with Home Enteral Nutrition, and 30 with Home Parenteral Nutrition. Home Enteral Nutrition is mainly applied in patients with neoplasias (36%) or neurological alterations (35%). The most commonly used access route in the nasogastric tube, although there is an observed increase in the application of Percutaneous Gastrostomies (21%) in relation to previous data of the Spanish population. There is an observed complications index of 0.07 episodes/patient-year, a mortality of 30% (neoplasias) and 20% (neurological alterations), and low rehabilitation indexes in this group. In Home Parenteral Nutrition, post-radiation enteritis, neoplasias, and mesenteric ischemia, are the main diagnostic groups. The majority of the patients have a tunneled tube (63%), with 37% using an implanted tube. With an index of hospitalizations of 0.83 hospitalizations/ patient-year, catheter septicemia justifies the majority of the re-hospitalizations derived from nutritional treatment (0.56 hospitalizations/patient-year), note the mortality of 37%. There are complete rehabilitations, continuing the previously normal activity in 80% of the cases.     

Investigation of the Metal–Oxide Buried Interfacial Zone with Linear Sweep Voltammetry

Interest in copper as a technologically important material needs to be met with greater understanding of the fundamental chemical reactions of copper. In particular, there is still a lack of universal agreement on the oxidation process of bulk copper and thin copper films. In this study, the authors demonstrate the use of linear sweep voltammetry (LSV) to study buried structures in the oxide layers on copper. In particular, LSV can be used to detect reactions at buried interfaces. It is also emphasized that surface scientists should recognize Cu₃O₂ and the decomposition of copper oxides at the metal–oxide interface in new studies on copper oxidation and in interpreting already existing copper oxidation data. The two key parameters that drive oxide growth and decomposition are demonstrated to be oxygen activity and the free energies of formation of the oxides (per mole of oxide ion). The complex nature of the oxidation of copper, as well as other metals and alloys, can be described qualitatively using the Modified Cabrera–Mott (C–M) Model. Surface studies of oxidation of metals and alloys need to be supported and complemented by other techniques such as chemical or electrochemical methods.