Errors in lamina growth of primary olfactory axons in the rat and mouse olfactory bulb

In the adult olfactory nerve pathway of rodents, each primary olfactory axon forms a terminal arbor in a single glomerulus in the olfactory bulb. During development, axons are believed to project directly to and terminate precisely within a glomerulus without any exuberant growth or mistargeting. To gain insight into mechanisms underlying this process, the trajectories of primary olfactory axons during glomerular formation were studied in the neonatal period. Histochemical staining of mouse olfactory bulb sections with the lectin Dolichos biflorus-agglutinin revealed that many olfactory axons overshoot the glomerular layer and course into the deeper laminae of the bulb in the early postnatal period. Single primary olfactory axons were anterogradely labelled either with the lipophilic carbocyanine dye, 1,1'-dioctodecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI), or with horseradish peroxidase (HRP) by localized microinjections into the nerve fiber layer of the rat olfactory bulb. Five distinct trajectories of primary olfactory axons were observed in DLI-labelled preparations at postnatal day 1.5 (P1.5). Axons either coursed directly to and terminated specifically within a glomerulus, branched before terminating in a glomerulus, bypassed glomeruli and entered the underlying external plexiform layer, passed through the glomerular layer with side branches into glomeruli, or branched into more than one glomerulus. HRP-labelled axon arbors from eight postnatal ages were reconstructed by camera lucida and were used to determine arbor length, arbor area, and arbor branch number. Whereas primary olfactory axons display errors in laminar targeting in the mammalian olfactory bulb, axon arbors typically achieve their adult morphology without exuberant growth. Many olfactory axons appear not to recognize appropriate cues to terminate within the glomerular layer during the early postnatal period. However, primary olfactory axons exhibit precise targeting in the glomerular layer after P5.5, indicating temporal differences in either the presence of guidance cues or the ability of axons to respond to these cues. (C) 1999 Wiley-Liss, Inc.

Expression of EphA5 during development of the olfactory nerve pathway in rat

The olfactory neuroepithelium is a highly plastic region of the nervous system that undergoes continual turnover of primary olfactory neurons throughout life. The mechanisms responsible for persistent growth and guidance of primary olfactory axons along the olfactory nerve are unknown. In the present study, we used antibodies against the Eph-related receptor, EphA5, to localise EphA5, and recombinant EDhA5-IgG fusion protein to localise its ligands. We found that although both EphA5 and its ligands were both expressed by primary olfactory neurons within the embryonic olfactory nerve pathway, there was no graded or complementary expression pattern. In contrast, the expression patterns altered postnatally such that primary olfactory neurons expressed the ligands, whereas the second-order olfactory neurons, the mitral cells, expressed EphA5. The role of EphA5 was analysed by blocking EphA5-ligand interactions in explant cultures of olfactory neuroepithelium using anti-EphA5 antibodies and recombinant EphA5. These perturbations reduced neurite outgrowth from explant cultures and suggest that intrafascicular axon repulsion may serve to limit adhesion and optimise conditions for axon growth. (C) 2000 Wiley-Liss, Inc.

Metal-directed synthesis routes to a 16-membered tetraazamacrocycle with two pendant primary amine groups

The reaction of the bis(propane-1,3-diamine)copper(II) ion with paraformaldehyde and nitroethane in dry methanol under basic conditions produces a macrocyclic product, (cis-3,11-dimethyl-3,11-dinitro-1,5,9,13-tetraazacyclohexadecane)copper(II) perchlorate, in low yield, compared with the good yield obtained in the parallel chemistry possible even under aqueous conditions using palladium(II) as a template. The palladium complex was reduced with zinc amalgam in dilute aqueous acid to yield the metal-free 16-membered macrocyclic hexaamine, in this case re-complexed and characterised by an X-ray crystal structure as the (cis-3,11-dimethyl-1,5,9,13-tetraazacyclohexadecane-3,11-diamine)copper(II) perchlorate. The copper ion is found in a tetragonally elongated and trigonally-distorted octahedral environment, with all six of the ligand nitrogens coordinated, the two primary amine pendant groups occupying cis sites. (C) 2000 Elsevier Science S.A. All rights reserved.

The development and evaluation of an incontinence screening questionnaire for female primary care

Although there is a high prevalence of leaking urine among Australian women, there are currently no standardized procedures for screening patients for incontinence in the primary care setting (known in Australia as general practice). In response to this, an incontinence screening questionnaire (ISQ) was developed and evaluated for use in general practice. Eighty-nine women completed an original compilation of 33 items that asked about situations associated with leaking urine, avoidance of leakage, and concern about leakage. Each item was assessed according to its acceptability for the population of female general practice patients, discriminative value, and test-retest reliability. These patients also underwent an objective test of incontinence, the 48-hour pad test, so that the screening items could be validated against an objective classification of incontinence. The study included women who had bladder control problems and those who did not. Eight items on the ISQ were shown to be acceptable to patients, discriminative, reliable, and valid indicators of objective incontinence. Five items were capable of predicting almost 70% of patients who showed objective leakage of urine and misclassified fewer than 15% of these patients. Those five items were selected for inclusion in the (refined) ISQ. (C) 2000 Wiley-Liss, Inc.

Effect of removing user fees on attendance for curative and preventive primary health care services in rural South Africa

User fees are used to recover costs and discourage unnecessary attendance at primary care clinics in many developing countries. In South Africa, user fees for children aged under 6 yea rs and pregnant women were removed in 1994, and in 1997 all user fees at all primary health care clinics were abolished. The intention of these policy changes was to improve access to health services for previously disadvantaged communities. We investigated the impact of these changes on clinic attendance patterns in Hlabisa health district. Average quarterly new registrations and total attendances for preventive services (antenatal care, immunization, growth monitoring) and curative services (treatment of ailments) at a mobile primary health care unit were studied from 1992 to 1998. Regression analysis was undertaken to assess whether trends were statistically significant. There was a sustained increase in new registrations (P = 0.0001) and total attendances (P = 0.0001)for curative services, and a fall in new registrations (P = 0.01) and total attendances for immunization and growth monitoring (P = 0.0002) over the study period. The upturn in demand for curative services started at the time of the first policy change. The decreases in antenatal registrations (P = 0.07) and attendances (P = 0.09) were not statistically significant The number of new registrations for immunization and growth monitoring increased following the first policy change but declined thereafter. We found no evidence that the second policy change influenced underlying trends. The removal of user fees improved access to curative services but this may have happened at the expense of some preventive services. Governments should remain vigilant about the effects of new health policies in order to ensure that objectives are being met.

Health for all beyond 2000: the demise of the Alma-Ata Declaration and primary health care in developing countries

Access to basic health services was affirmed as a fundamental human right in the Declaration of Alma-Ata in 1978. The model formally adopted for providing healthcare services was primary health care (PHC), which involved universal, community-based preventive and curative services, with substantial community involvement. PHC,did not achieve its goals for several reasons, including the refusal of experts and politicians in developed countries to accept the principle that communities should plan and implement their own heathcare services. Changes in economic philosophy led to the replacement of PHC by Health Sector Reform, based on market forces and the economic benefits of better health. It is time to abandon economic ideology and determine the methods that will provide access to basic healthcare services for all people.

Francoist Primary education: the schoolbook as an instrument of child indoctrination

The Francoist rule, mainly in its first decades, exerted a strong control upon education, which was left in the hands of the Catholic nationalist. Innumerous children`s schoolbooks were published driven by strong patriotic and religious bias. The authors aimed to shape the children`s minds based on the premises that supported the regimen: authority, hierarchy, order, abeyance, fear and devotion to God and the leader Francisco Franco. This paper analyzes the content of the elementary education books and shows how they were important instruments of child indoctrination marked by intolerance. The content and the images of the books contributed to construct an excluding national identity based on a heightened Catholic patriotism, stimulated heroism, martyrdom, child sacrifice, and hatred for the enemies of the religion and of ""mother Spain"".

Adoptive transfer of gene-engineered CD4+ helper T cells induces potent primary and secondary tumor rejection

Because CD4(+) T cells play a key role in aiding cellular immune responses, we wanted to assess whether increasing numbers of gene-engineered antigen-restricted CD4(+) T cells could enhance an antitumor response mediated by similarly gene-engineered CD8(+) T cells. In this study, we have used retroviral transduction to generate erbB2-reactive mouse T-cell populations composed of various proportions of CD4(+) and CD8(+) cells and then determined the antitumor reactivity of these mixtures. Gene-modified CD4(+) and CD8(+) T cells were shown to specifically secrete Tc1 (T cytotoxic-1) or Tc2 cytokines, proliferate, and lyse erbB2(+) tumor targets following antigen ligation in vitro. In adoptive transfer experiments using severe combined immunodeficient (scid) mice, we demonstrated that injection of equivalent numbers of antigen-specific engineered CD8(+) and CD4(+) T cells led to significant improvement in survival of mice bearing established lung metastases compared with transfer of unfractionated (largely CD8(+)) engineered T cells. Transferred CD4(+) T cells had to be antigen-specific (not just activated) and secrete interferon gamma (IFN-gamma) to potentiate the antitumor effect. Importantly, antitumor responses in these mice correlated with localization and persistence of gene-engineered T cells at the tumor site. Strikingly, mice that survived primary tumor challenge could reject a subsequent re-challenge. Overall, this study has highlighted the therapeutic potential of using combined transfer of antigen-specific gene-modified CD8(+) and CD4(+) T cells to significantly enhance T-cell adoptive transfer strategies for cancer therapy.