Linear Unsaturated Polyamides: Nylons 6 u18 and 18 u18

Summary: Linear unsaturated nylons 6 u18 and 18 u18 have been made containing a double bond in the center of the diacid segment with potential for additional functionalization. Solution state NMR showed the presence of a small portion of cis amide units. Solid state NMR verified the presence of the double bond in the bulk, and that the polyamides were present in the α‐crystalline form. Thermal stability was comparable to linear saturated nylons, and the melting and crystallization temperatures of the unsaturated nylons were lower compared to the saturated analogs.

DSC heating and cooling thermograms for nylons 6 u18 and 18 u18.     

Genome-wide linkage analysis of families with obsessive-compulsive disorder ascertained through pediatric probands

The goal of this study was to identify chromosomal regions likely to contain susceptibility alleles for early-onset obsessive-compulsive disorder (OCD). A genome scan was done in 56 individuals from seven families ascertained through pediatric OCD probands; 27 of the 56 subjects had a lifetime diagnosis of definite OCD. Denser mapping of regions on chromosomes 2, 9, and 16 was subsequently done with those subjects and ten additional subjects from the largest family in the study. Direct interviews were completed with 65 of the 66 genotyped individuals. Relatives were interviewed blind to proband status. Of the 65 interviewed individuals, 32 had a lifetime diagnosis of definite OCD. Three of the seven probands had a history of Tourette disorder. Two of the 25 relatives with OCD had a tic history, whereas none of the 33 relatives without OCD had tics. The genome scan consisted of 349 microsatellite markers with an average between-marker distance of 11.3 centiMorgan (cM). Fine mapping was done with 24 additional markers at an average spacing of 1.6 cM. Parametric and nonparametric linkage analyses were conducted using GENEHUNTER(+). The maximum multipoint LOD score with a dominant model was 2.25 on 9p. However, with fine mapping and additional subjects, that LOD score decreased to 1.97. The maximum multipoint nonparametric LOD* score was 1.73 on 19q. The maximum multipoint LOD score with a recessive model was 1.40 on 6p. The results provide suggestive evidence for linkage on 9p and identify regions requiring further study with much larger samples.     

Long-term working memory in the rat: effects of hippocampally applied anisomycin

The extent to which protein synthesis is involved in working memory was investigated with the protein synthesis inhibitor anisomycin (ANI). Rats were trained to perform accurately on a 12-arm radial maze when delays of 240 min were interposed between choice 6 and choice 7. Bilateral hippocampal cannulas were then implanted. Accuracy on choices 7-12 was studied when ANI or saline was injected either 30 min before choice 1 or 5-10 min after choice 6 (Experiment 1). Pretrial injection of ANI significantly impaired performance following the 240-min delay, whereas ANI injected during the delay had no such effect. In Experiments 2 and 3, the ANI-induced amnesia was replicated, and the temporal course of development of the amnesia was determined. Pretrial administration of ANI did not significantly affect retention after a 2-min delay but did produce amnesia after delays of 15 min or longer. These data suggest that protein synthesis is important for the formation of temporary memories, provided the retention interval is long enough. It is suggested that working memory includes both short-term and long-term components. Protein synthesis appears to be important for formation of the long-term component, but not the short-term component, of working memory.     

Adjustment in Childhood Brain Tumor Survival: Child, Mother, and Teacher Report

Examined the adjustment of 6- to 18-year-old children and adolescents(n = 38) 2 to 5 years postdiagnosis of brain tumor with respectto standardized measures of anxiety and depression; self-perceptions;and adaptive living skills. Child, mother, and teacher reportdata were used. Maternal adjustment (anxiety and depression,parenting stress) was also assessed. Children and adolescentssurviving brain tumors reported themselves to be generally withinthe normal range. However, maternal ratings of social problemswere higher than normative scores and significantly lower thannorms on social problems, scholastic competence, and communicationskills. Teacher ratings on the Teacher Rating Form were allwithin normal limits. Maternal adjustment measures were withinthe normal range, although the Parent-Child Dysfunctional Interactionsubscale of the Parenting Stress Index was elevated. No differencesin scores were found between children in regular and specialeducation, or between children who had received radiation andthose who did not. This sample of survivors of pediatric braintumors and their mothers had relatively mild problems in adjustment,supporting a competency-based view of the adaptation of pediatricpatients and their families.     

Intraventricular insulin and leptin reverse place preference conditioned with high-fat diet in rats

The authors hypothesized that insulin and leptin, hormones that convey metabolic and energy balance status to the central nervous system (CNS), decrease the reward value of food, as assessed by conditioned place preference (CPP). CPP to high-fat diet was blocked in ad-lib fed rats given intraventricular insulin or leptin throughout training and test or acutely before the test. Insulin or leptin given only during the training period did not block CPP. Thus, elevated insulin and leptin do not prevent learning a food's reward value, but instead block its retrieval. Food-restricted rats receiving cerebrospinal fluid, insulin, or leptin had comparable CPPs. Results indicate that the CNS roles of insulin and leptin may include processes involving memory and reward.     

Recent changes among human influenza viruses

Recurrent epidemics of influenza are due to the frequent emergence of antigenic variants. With co-circulation of two influenza A subtypes and two antigenically distinct lineages of B viruses, genetic reassortment also has an important role in antigenic drift, as illustrated by recent changes in both A and B viruses. The H1N2 subtype viruses, which emerged during 2001, possessed a H1 HA similar to those of contemporary A/New Caledonia/20/99 (H1N1)-like viruses and seven genes closely related to those of recent H3N2 viruses, and did not represent a significant increase in the antigenic diversity of circulating viruses. The re-emergence of B/Victoria/2/87-lineage viruses, previously prevalent during the 1980s, in 2000 has been followed by the predominant circulation of reassortant B viruses possessing a B/Victoria-lineage HA and a B/Yamagata-lineage NA similar in sequence to those of recent B/Sichuan/379/99-like viruses. These events emphasize not only the lack of divergence in the complementary functional characteristics of the HA and NA of divergent influenza B lineages, but also the apparent convergence in compatibility between the H1 and N2 components of the two influenza A subtypes.     

Nationwide epidemic of septicemia caused by contaminated intravenous products: mechanisms of intrinsic contamination.

Between 1 July 1970 and April 1971, in many hospitals in this country, there were outbreaks of nosocomial septicemia caused by Enterobacter cloacae of E. agglomerans (formerly Erwinia, herbicola-lathyri). All of these hospitals used infusion products manufactured by one company, Abbott Laboratories, and all affected patients had onset of septicemia while receiving the company's infusion products. Septicemia was epidemiologically and microbiologically traced to intrinsic contamination of the company's screw-cap closure for infusion bottles which was sealed with a newly introduced elastomer liner. Epidemic organisms were isolated from these closures. Investigations both in the laboratory and in the manufacturing plant into the mechanism of contamination of these products revealed the following. (i) Epidemic strains were present in numerous areas throughout the manufacturing plants. (ii) Viable microorganisms gained access to the interior of screw-cap closures after the autoclave step of production. (iii) Cooling closures actively drew moisture through the thread interstices into the inner-most depths of the closure. (iv) Transfer of contaminants from closures to fluid was easily effected by simple manipulations duplicating normal in-hospital use. (v) The red-rubber liner used in the company's screw-cap closures before the introduction of elastomer contained a broad-spectrum antimicrobial inhibitor. The findings from this epidemic and the associated studies show that the screw-cap closure as it is now designed cannot be considered secure for products that must remain sterile.