Mitogenic proteins of pokeweed. II. The differentiation of human peripheral blood B lymphocytes stimulated with purified pokeweed mitogens (Po-2 and Po-6) from pokeweed, Phytolacca octandra.

Purified pokeweed mitogens, Po-2 and Po-3, extracted from Phytolacca octandra, stimulated plasma cell formation in cultures of human peripheral blood lymphocytes. Plasma cell formation did not occur in cultures of purified B cells but was dependent on T-cell help. High T-cell numbers, however, suppressed plasma cell formation in mixed B- and T-cell cultures stimulated with Po-2. T-cell helper function was exerted across a major histocompatibility barrier and was not dependent on T-cell proliferation. Soluble helper factor(s) from activated T cells were not demonstrated. Po-3 was an effective B-cell stimulant only at concentrations between 0.1 and 1.0 micrograms/ml. In contrast, relatively high concentrations of Po-2 (50--100 micrograms/ml) were required to induce B-cell differentiation. More plasma cells were generated in Po-2-stimulated cultures than in Po-3-stimulated cultures and this was thought to reflect the more aggregated state of Po-2.     

Age-related loss of synaptophysin immunoreactive presynaptic boutons within the hippocampus of APP751SL, PS1M146L, and APP751SL/PS1M146L transgenic mice

Neuron and synapse loss are important features of the neuropathology of Alzheimer's disease (AD). Recently, we observed substantial age-related hippocampal neuron loss in APP751SL/PS1M146L transgenic mice but not in PS1M146L mice. Here, we investigated APP751SL mice, PS1M146L mice, and APP751SL/PS1M146L mice for age-related alterations in synaptic integrity within hippocampal stratum moleculare of the dentate gyrus (SM), stratum lucidum of area CA3 (SL), and stratum radiatum of area CA1-2 (SR) by analyzing densities and numbers of synaptophysin-immunoreactive presynaptic boutons (SIPBs). Wild-type mice, APP751SL mice and PS1M146L mice showed similar amounts of age-related SIPB loss within SM, and no SIPB loss within SL. Both APP751SL mice and PS1M146L mice showed age-related SIPB loss within SR. Importantly, APP751SL/PS1M146L) mice displayed the severest age-related SIPB loss within SM, SL, and SR, even in regions free of extracellular Abeta deposits. Together, these mouse models offer a unique framework to study the impact of several molecular and cellular events caused by mutant APP and/or mutant PS1 on age-related alterations in synaptic integrity. The observation of age-related SIPB loss within SR of PS1M146L mice supports a role of mutant PS1 in neurodegeneration apart from its contribution to alterations in Abeta generation.     

Modulation of osteopontin in proteinuria-induced renal interstitial fibrosis

Proteinuria is associated with macrophage-dependent interstitial fibrosis (IF). Osteopontin (OPN), a macrophage chemoattractant, may be involved in the transition of proteinuria to IF but protective properties have also been reported. To elucidate whether OPN may be involved in the proteinuria-induced cascade of tubulointerstitial damage, renal expression of OPN was studied during the development of proteinuria-induced renal damage and during anti-proteinuric intervention with ACE inhibition (ACEi). First, the temporal relationships between proteinuria, interstitial OPN induction, and IF in adriamycin nephrosis (AN), a model of chronic proteinuria-induced renal damage, were studied. Second, the effect of anti-proteinuric treatment on OPN expression was investigated. The time course of OPN induction and markers of renal damage was studied in rats with unilateral AN at 6-week intervals until week 30. In a second study, a renal biopsy was taken 6 weeks after induction of bilateral AN; subsequently, rats were treated with ACEi until termination (week 12). In unilateral AN, proteinuria developed gradually and stabilized at week 10. In proteinuric kidneys, OPN expression was induced from week 12 onwards. Simultaneously, a progressive increase in interstitial macrophages, alpha-smooth muscle actin (alpha-SMA), collagen type III, and focal glomerulosclerosis (FGS) was observed. In bilateral AN, ACEi reduced proteinuria and OPN protein and stabilized fibrosis. In untreated animals, OPN mRNA increased, with stable OPN protein and fibrosis and increased FGS. Thus, in AN, development of proteinuria is followed by up-regulation of OPN along with markers of renal damage. The up-regulation of OPN is reversible by anti-proteinuric treatment without a corresponding reduction in fibrosis. Whereas these data are consistent with a role for OPN in the cascade of transition from proteinuria to fibrosis, intervention with ACEi showed that reduction of OPN does not attenuate established fibrosis.     

Behavioral and hormonal effects of attachment object separation in surrogate-peer-reared and mother-reared infant rhesus monkeys

Mother-reared and surrogate-peer-reared rhesus monkeys were separated from their respective attachment objects at 6 months of age and tested for the following 9 weeks to determine their home cage behavior and their pituitary-adrenocortical responses to stress. Both groups displayed a strong immediate behavioral response to separation which was characterized by increases vocalization, increased locomotion, and decreased self-play. However, the surrogate-peer-reared infants showed a subsequent recovery in their levels of self-play whereas the mother-reared infants instead developed stereotypic behavior patterns such as repetitive pacing. The 2 groups displayed similar plasma cortisol responses to weekly sessions in an apparatus equipped with animated toy “monsters.” Mother-reared but not surrogate-peer-reared subjects, however, also manifested elevated cortisol levels when an animal in an adjacent cage was captured and removed for stress testing. Mother-reared infant monkeys thus responded in a stronger and more prolonged manner to the loss of their attachment object than surrogate-peer-reared infants. These results suggest that infant rhesus monkeys form stronger attachments to monkey mothers than to inanimate surrogate mothers, a phenomenon which has not been as clearly demonstrated using other indices of attachment strength.     

Evaluations of commercial West Nile virus immunoglobulin G (IgG) and IgM enzyme immunoassays show the value of continuous validation

West Nile virus was introduced into the United States in 1999 and in only four seasons has become endemic east of the Rocky Mountains. Recently, immunoglobulin M (IgM)-capture enzyme immunoassays for the detection of West Nile virus-specific IgM and indirect IgG enzyme immunoassays for the detection of IgG antibodies against West Nile virus were made available from Focus Technologies and PANBIO, Inc. We evaluated these commercial IgG and IgM test systems and determined agreement, sensitivity, and specificity for the assays, compared to immunofluorescence assay and the Centers for Disease Control and Prevention's IgM-capture enzyme-linked immunosorbent assay (ELISA). Initially, the Focus and PANBIO IgM enzyme immunoassays had at least 95% agreement, sensitivity, and specificity, and, based on the 95% confidence intervals, both IgM-capture assays performed similarly. The IgG assays also performed well, although the Focus IgG assay demonstrated greater specificity (98.8%) and the PANBIO IgG assay demonstrated greater sensitivity (99.3%). However, for 400 samples consecutively submitted for West Nile virus antibody testing during 2 days of the 2003 West Nile virus season, agreement, clinical sensitivity, and clinical specificity were 93.1, 98.0, and 92.4%, respectively, for the PANBIO IgM assay and were 97.4, 100.0, and 97.1%, respectively, for the Focus IgM assay. The specificities observed in this second evaluation equates to an overall false-positivity rate of 6.3% in the PANBIO West Nile virus IgM-capture ELISA versus 2.5% with the Focus West Nile virus IgM-capture ELISA. This experience demonstrates the importance of continuously evaluating the performance of an assay in order to detect any changes in assay performance as the test population evolves.     

Surgery-attached psychogeriatric nurses: an evaluation of psychiatric nurses in the primary care team

Aspects of the work of five community psychiatric nurses are examined by means of a questionnaire completed by the nurses for a sample of 50 patients. Information sharing and a close working relationship with the general practitioner, skills relating to assessment and psychological support of patients, organization of care by other agencies, a detailed knowledge of community agencies, and a capacity for interdisciplinary working were all found to be important. Tasks relating to body care were reported in only a small number of cases. The nurses saw themselves as advising on the planning of patient management and the selection of medication in a substantial minority of cases. The original brief had been to care for psychogeriatric patients but a third of the patients fell into a younger age group. These findings are discussed in connection with their implications for the future training of nurses and the relationship between primary care teams and local psychiatric services.     

The University of Missouri-Kansas City School of Medicine: thirty-five years of experience with a nontraditional approach to medical education.

The University of Missouri-Kansas City (UMKC) School of Medicine is a public medical school that opened in 1971 in response to a need to train more physicians in Missouri. As a six-year, integrated, combined-degree program leading to the baccalaureate and medical degrees, the school offers an innovative, nontraditional approach to medical education. In the past 35 years, UMKC has graduated over 2,400 physicians who are successful according to outcomes measures used at other medical schools. With recent interest in reforming medical education to prepare physicians for a changing world, a review of alternative models may be especially instructive.UMKC's academic plan offers a blueprint for the curriculum plan and governance of the school. The plan is built on four hallmarks: (1) a combined baccalaureate/MD program, (2) early exposure to clinical medicine, (3) small-group learning through the docent system, and (4) a continuing ambulatory care clinic experience for four years.This article catalogs the results of this plan including student, faculty, and graduates' perceptions of and satisfaction with the school's educational approach, students' achievement on licensing examinations and in the residency match, graduates' performance in residency programs, and their subsequent career patterns. The authors also discuss lessons learned and adjustments made in response to local needs in the context of a changing environment in education, health care, and health care delivery while continually improving the school's nontraditional approach to medical education. These include changes in basic and clinical science instruction, student assessment, faculty development, and funding and governance.     

Influenza A virus-induced apoptosis is a multifactorial process: exploiting reverse genetics to elucidate the role of influenza A virus proteins in virus-induced apoptosis

Three influenza viruses, A/Puerto Rico/8/34-A/England/939/69 clone 7a (H3N2), A/Fiji/15899/83 (H1N1), and A/Victoria/3/75 (H3N2), induce different levels of apoptosis in vitro at equal moi; Clone 7a > A/Victoria > A/Fiji. Previous studies have shown that several viral proteins from clone 7a and A/Fiji, including PB2, NA, NS1, M1, and M2, induce apoptosis when expressed individually fused to the herpes simplex virus tegument protein, VP22. However, this did not reflect viral protein-protein-RNA interactions known to occur within infected cells. To explore the role of viral proteins in apoptosis under infection conditions, recombinant viruses with single or triple gene exchanges were generated using A/Victoria or clone 7a as the background virus. Inserting the A/Fiji NS or PB2 gene into A/Victoria or clone 7a significantly reduced the level of apoptosis compared to the parent virus while clone 7a PA or NP genes increased apoptosis. Inserting A/Fiji NA or HA or clone 7a NS, M, NA, or HA genes individually into A/Victoria had no significant effect on apoptosis. Surprisingly, inserting the M, NA, and HA genes of A/Fiji together into clone 7a reduced apoptosis, whereas inserting clone 7a M, NA, and HA together into A/Fiji increased apoptosis. These results suggest that no single virus protein induces apoptosis and that the combination of genes required may be strain specific, highlighting the difficulty of predicting the virulence of new strains that arise in nature. No support for the view that apoptosis is essential for high virus yields was obtained as high virus yields were obtained with viruses that induced both high and low levels of apoptosis.     

Inactivation of Exonuclease 1 in mice results in DNA mismatch repair defects,increased cancer susceptibility,and male and female sterility

Exonuclease 1 (Exo1) is a 5'-3' exonuclease that interacts with MutS and MutL homologs and has been implicated in the excision step of DNA mismatch repair. To investigate the role of Exo1 in mammalian mismatch repair and assess its importance for tumorigenesis and meiosis, we generated an Exo1 mutant mouse line. Analysis of Exo1(-/-) cells for mismatch repair activity in vitro showed that Exo1 is required for the repair of base:base and single-base insertion/deletion mismatches in both 5' and 3' nick-directed repair. The repair defect in Exo1(-/-) cells also caused elevated microsatellite instability at a mononucleotide repeat marker and a significant increase in mutation rate at the Hprt locus. Exo1(-/-) animals displayed reduced survival and increased susceptibility to the development of lymphomas. In addition, Exo1(-/-) male and female mice were sterile because of a meiotic defect. Meiosis in Exo1(-/-) animals proceeded through prophase I; however, the chromosomes exhibited dynamic loss of chiasmata during metaphase I, resulting in meiotic failure and apoptosis. Our results show that mammalian Exo1 functions in mutation avoidance and is essential for male and female meiosis.