Interference study of the chi c0(13P0) in the reaction -pp-->pi0pi0.

Fermilab experiment E835 has observed (-)pp annihilation production of the charmonium state chi(c0) and its subsequent decay into pi(0)pi(0). Although the resonant amplitude is an order of magnitude smaller than that of the nonresonant continuum production of pi(0)pi(0), an enhanced interference signal is evident. A partial wave expansion is used to extract physics parameters. The amplitudes J=0 and 2, of comparable strength, dominate the expansion. Both are accessed by L=1 in the entrance (-)pp channel. The product of the input and output branching fractions is determined to be B((-)pp-->chi(c0))xB(chi(c0)-->pi(0)pi(0))=(5.09+/-0.81+/-0.25)x10(-7).

Sex-related immune changes in young mice.

Here we describe changes in selected immune parameters related to age and sex in young mice. We focused on the T cell compartment and studied thymuses and spleens from mice 3 to 9 weeks of age in order to bracket the time period around murine puberty. With regard to distribution of immune cells, no significant sex-related changes were seen in thymocyte expression of CD3, CD4, CD8, or CD4/CD8 or splenocyte expression of CD3, CD4, CD8, or CD45R/B220, a pan B cell marker. For splenocytes, significantly more cells were positive for CD3 in older (6-9 week old) compared with younger (3-4 week old) mice. Splenocyte and thymocyte cell proliferation as measured by DNA synthesis in response to in vitro mitogens was compared for cells from male and female mice over the ages studied. Thymocyte proliferation was not related to age or sex of the mice. For splenocytes of the youngest mice (3 weeks old), the response to a cell surface-receptor-independent mitogenic combination of phorbol ester and ionomycin induced a significantly greater response in cells from female mice compared with male mice. This trend was reversed for mice of 4-6 weeks of age, where the response by splenocytes from males was significantly greater than that by cells from females. For mice 7-8 weeks of age, splenocytes from female mice responded significantly less to stimulation by antibody to CD3, a component of the T-cell receptor. Our results demonstrate that depending on the assays employed, sexual dimorphism in the immune system may be demonstrated prior to puberty.

Evolution of the cellular response in P2-induced experimental allergic neuritis.

We examined the development of the inflammatory cellular response and demyelination in P2 protein-induced experimental allergic neuritis (EAN). Collections of inflammatory cells were first identified in nerve roots 14 days after immunization. Ia+ cells predominated in the evolving lesions and T-helper cells were the dominant T-cell type with T-suppressor/cytotoxic cells appearing later in the course of the disease. Vesiculation, the earliest change seen in the myelin sheath, appeared before the wave of cellular infiltration. These results indicate that myelin injury precedes inflammation in P2 protein-induced EAN, and provide further evidence that this disorder is indistinguishable from EAN induced with whole peripheral nerve myelin.

Early myelin lesions in experimental allergic neuritis.

We examined the evolution of demyelination in spinal roots of Lewis rats immunized with whole nerve and complete Freund's adjuvant. Roots were morphologically normal until 11 days after immunization, when we found endoneurial edema and myelin vesiculation in the absence of mononuclear cell contacts. Macrophage-associated myelin stripping was not detected until day 12. Macrophage infiltrations were extensive by day 14, but lymphocytes were sparse. These observations indicate that in experimental allergic neuritis, myelin injury may occur before macrophage-mediated demyelination, and provide support for an early role of serum factors in the development of this disorder.

Effect of experimental allergic neuritis serum on normal rat peripheral nerve.

To study the possible in vivo activity of experimental allergic neuritis (EAN) serum, we injected serum from rats immunized with whole nerve, P2 protein or adjuvant alone into the sciatic nerve of normal Lewis rats. Serum from whole nerve and P2-immunized animals produced demyelination 24 h after injection. Only high-titer anti-P2 serum was active and no control serum had this effect. Anti-P2 antibodies or other serum factors may contribute to the pathogenesis of whole nerve and P2-induced EAN.

Expression of nerve growth factor receptor during human peripheral nerve development.

The expression of NGF receptors on human Schwann cells during development and myelination and in culture was analyzed using a murine monoclonal antibody to human NGF receptor. Nonmyelinated femoral nerves from 13- to 14-week fetuses stained strongly for NGF receptor, whereas tissues from later stages of development showed a decrease in the staining intensity. These changes correlated with the initiation of myelination (17-19 weeks), as observed by phase-contrast and electron microscopy, and the reactivity with monoclonal antibody 4C5, a marker of mature Schwann cells. In adult nerves, only the perineurium and few endoneurial cells were stained with anti-NGF receptor antibody. Cultured human fetal Schwann cells were positive for NGF receptor by immunofluorescence irregardless of donor age or length of time in culture. The decreased staining of NGF receptor with nerve maturation may reflect a dependence of antigen expression on Schwann cell differentiation and/or neuron-Schwann cell interaction.

Teenage fathers: working with the neglected partner in adolescent childbearing.

The Teen Father Collaboration, a two-year national research and demonstration project launched in 1983, was designed to determine the most effective ways to assist teenage fathers in contributing to their children's social, emotional and financial well-being. Eight social service agencies from around the country provided nearly 400 young fathers and prospective fathers--most 17 or 18 years of age--with a variety of services, including counseling, educational assistance and job training. Many young fathers wanted to contribute financially to their children's upbringing but had only a limited ability to do so because they were unemployed or needed job training. By the end of the project, 56 previously unemployed participants had taken part-time jobs, and 92 participants had found full-time employment; nearly half of the non-graduates who were not enrolled in school when they entered the program had returned to school, had obtained their GEDs or had enrolled in GED classes by the time the Collaboration ended. An aggressive approach to recruitment and a good knowledge of the community were considered to have been crucial to the success of the programs: Staff members had to be able to go into the community and reach young men on a one-to-one basis. The experiences of the agencies indicate that a man in his 20s or 30s from the same ethnic and cultural background as the teen-age clients usually succeeded best as a counselor. The study also shows that ambivalence on the part of a cooperating agency was probably the most important factor hindering the efforts of the Collaboration.(ABSTRACT TRUNCATED AT 250 WORDS)

PIP: In a national research and demonstration project designed to determine the the most effective ways to assist teenage fathers in contributing to their children's well-being, 8 social service agencies from around the US provided nearly 400 young fathers and prospective fathers with counseling, educational assistance and job training. By the end of the project, 56 previously unemployed participants had taken part-time jobs, and 92 participants had found full-time employment. Nearly 1/2 of the non-graduates who were not enrolled in high school when they entered the program had returned to school, had obtained their GEDs, or had enrolled in GED classes. An agressive approach to recruitment and good knowledge of the community were crucial to program success. Men in their 20s or 30s from the same ethnic and cultural background as the teenage clients usually succeeded best as counselors. Ambivalence on the part of a cooperating agency was probably the most serious hindrance to project efforts. Where top-level administrative support was lacking, the program was largely ineffectual. Nonetheless, the project may have helped to erase the stereotype that all teenage fathers neglect their parental responsibilities.

Demyelination in vivo by Guillain-Barré syndrome and other human serum.

Serum from patients with acute inflammatory polyneuropathy (the Guillain-Barré syndrome, GBS) demyelinates peripheral nerves in vivo more intensely than control human serum. To clarify the processes leading to demyelination we injected rat sciatic nerves with serum from GBS and control subjects in the presence of complement and examined the sequential morphologic changes over 7 days. One day after injection, five of six GBS sera but none of seven control sera caused vesicular demyelination; 3-5 days after injection both GBS and control sera produced macrophage-mediated demyelination. These observations suggest that GBS serum can initiate acute myelin injury through a humoral mechanism that is disease associated. This response appears to be distinct from delayed cell-mediated serum-induced demyelination that is not disease specific.

Acute canine idiopathic polyneuropathy (ACIP) serum demyelinates peripheral nerve in vivo.

We examined the in vivo demyelinating activity of serum from dogs with acute canine idiopathic polyneuropathy (ACIP), a Guillain-Barré syndrome (GBS)-like illness. Sera from 6 ACIP cases demyelinated rat sciatic nerves more intensely than 11 control sera. Serum activity increased after guinea pig serum (gps) was added, although gps alone had little effect. ACIP sera did not bind more to whole nerve cross sections or Schwann cells in vitro than control sera, and did not contain elevated antigalactocerebroside titers. We do not as yet know the pathogenic importance of the demyelinating factor in ACIP and control dog serum, or understand its relationship to the demyelinating constituent in serum from humans with GBS.