Carbon Ion Fluxes at Mars: First Results of Tailward Flows From MAVEN-STATIC.

Characterizing C+ ions in the Martian ionosphere is important for understanding the history of the Martian atmosphere and surface due to its place in understanding carbon escape. Measuring minor ions, like C+, which are close in mass to major atmospheric ions, in this case O+, is difficult, requiring fitting algorithms and accurate background subtraction. Accurate measurement of these species is essential for understanding chemistry and transport in the ionosphere. In this paper, we use data from the Mars Atmospheric and Volatile EvolutioN SupraThermal And Thermal Ion Composition (MAVEN-STATIC) sensor to report the first C+ fluxes measured in the Martian magnetotail. We will describe a multistep method of background subtraction as well as fitting routines that are used to extract C+ fluxes from a 40-orbit subset of STATIC data. Our results show tailward fluxes in both optical shadow and the adjacent sunlit magnetotail at high altitudes ( > 3,000 km) and Mars-ward at low altitudes ( < 2,000 km) in shadow. These local flux values are similar to estimates of neutral carbon fluxes from photochemical escape. However, total carbon loss comparisons will require a more comprehensive study of integrated C+ loss over a larger data set from the Martian magnetotail.

Syntheses of semiconductor nanoparticles using single-molecular precursors.

Methods for the preparation of II-VI, III-V, and II-V as well as other compound semiconductor nanoparticles using main group single-molecular precursors have been developed. The work involves the design and synthesis of compounds containing all the elements required within the desired nanoparticulate material. Precursors are tailored to give reproducible, clean decomposition at moderate temperatures, leading to high quality, defect free, mono-dispersed nanoparticles. In this article we cover key aspects of precursor and nanoparticle synthesis. One of the more successful and reproducible series of single-source precursors used, and the one on which we have concentrated our research efforts, is the bis(dialkyldithio-/diseleno-carbamato)cadmium(II)/zinc(II) compounds, M(E(2)CNR(2))(2) (M = Zn or Cd, E = S or Se, and R = alkyl) for the preparation of chalcogenide nanoparticulate materials. Preliminary mechanistic studies suggest that the precursor to nanoparticle deposition route is strongly influenced by the alkyl substituent groups present, and may well determine the phase and quality of the final metal chalcogenide nanoparticles produced. Herein we discuss the synthesis of semiconductor nanoparticles using such single-molecular precursors.

A Phase I clinical trial of immunotherapy with interferon-gamma gene-modified autologous melanoma cells: monitoring the humoral immune response.

BACKGROUND: Tumor cells transduced with cytokine genes provide immunogenic vaccines for cancer immunotherapy. METHODS: A Phase I clinical trial was conducted for the specific active immunization of melanoma patients with interferon-gamma (IFN-gamma) gene-modified autologous melanoma tumor cells. Short term melanoma cultures were transduced retrovirally with the gene for human IFN-gamma. The genetically modified melanoma cells secreted biologically active IFN-gamma and showed enhanced expression of major histocompatibility complex class I and class II surface antigens. These cells were inactivated by irradiation (50 gray) and were cryopreserved for the vaccine. Twenty melanoma patients were enrolled in this clinical trial. The immunizations were administered in escalating doses once every 2 weeks for 3 months. The first and second injections consisted of 2 million cells, followed by 6 million for the third and fourth injections, and then 18 million for the fifth and sixth injections. The humoral immune responses of the patients were assessed by enzyme-linked immunoadsorbent assay, radioimmunoassay, and radioimmunoprecipitation. RESULTS: Thirteen of the 20 patients completed the immunization protocol. Eight of these 13 patients showed a humoral immunoglobulin (Ig)G response against autologous and allogeneic melanoma cells. The other five patients either had no detectable antimelanoma antibodies or showed a weak IgG response that did not rise significantly above the preimmune level. All the sera contained low or undetectable levels of antimelanoma IgM antibodies. The IgG response increased progressively in titer during the course of immunization. The positive sera showed preferentially strong binding to melanoma cell lines and some cross-reactivity to nonmelanoma tumors. A 75-80 kD antigen on melanoma cells was immunoprecipitated by postimmune sera of 3 of the responding patients. Preimmune sera from these three patients and sera from other patients immunized with a standard nontransduced melanoma cell vaccine failed to precipitate this antigen. Two patients with significant increases in serum IgG had clinical tumor regression, and two additional patients with low serum IgG response had transient shrinkage of nodular disease during therapy. CONCLUSIONS: These data suggest that gene therapy with IFN-gamma-transduced melanoma cells is safe and worthy of further investigation in patients with less advanced stage malignant melanoma. The ability to monitor changes in the humoral responses of the immunized patients has been demonstrated.

AIDS: MetLife's experience.

The national health burden created by AIDS/HIV disease has had a significant impact on the insurance industry. In an analysis of the MetLife health and life insurance claims from 1986 through 1989, it was found that a total of $323,900,000 has been paid for AIDS/HIV disease. This figure and related information from those years were based on the Company's underwriting and claims files, with personal and group operations reported separately. Personal life insurance claims rose from 344 in 1986 to 874 in 1989 with the dollar amounts increasing from $3.2 million to $8.9 million. In 1989 there were 689 group life claims with a face amount of $31.5 million and 6,450 people who received group medical claim payments for a total of $111.2 million. In 1989 AIDS claims comprised 1.61 percent of MetLife claims--up from 0.4 percent in 1986.

Shared pharmacy services: a cost-effective programme for small hospitals.

A pilot project for shared pharmacy service was undertaken to investigate costs and benefits under an agreement established between University Hospital, London and South Huron Hospital, Exeter, Ontario. The programme involved the use of facsimile telecopiers to transmit direct copies of the physicians' orders to the Pharmacy Department at University Hospital where they were entered into the computerized pharmacy system. At South Huron Hospital therapy was initiated from floor stock while the drug, dispensed in unit-of-use packaging, was delivered to the Exeter Hospital by courier service. The shared service pharmacist visited South Huron Hospital once weekly for nursing orientations, inservice lectures, patient consultations, medical staff meetings and direct contact with physicians. With the approval of the Bureau of Dangerous Drugs the pharmacist delivered Narcotic and Schedule G medications once weekly. After three months the patient census and average number of medication orders per patient per day had increased. The hours of pharmacy operation were extended, while the medication costs per patient day were reduced from $2.16 to $1.64. A shared pharmacy service can result in an improved element of drug use control for smaller hospitals in a cost-effective manner.

DTIC, CCNU, bleomycin and vincristine (BOLD) in metastatic melanoma.

Treatment of 91 consecutive patients having metastatic, Stage IV melanoma who had not received any previous chemotherapy was begun between January 1977 and April 1978. The therapy included bleomycin (B) at 7.5 units subcutaneously in the first course and 15 units in subsequent courses on days 1 and 4; vincristine or Oncovin (O) at 1 mg/m2 intravenously on days 1 and 5; CCNU or lomustine (L) at 80 mg/m2 p.o. on day 1 and DTIC (D) 200 mg/m2 intravenously on days 1 through 5. Evaluable patients (72) were those who had measurable tumours in the viscera and on the skin. Seven patients (9%) responded with complete tumor regression (CR), 22 (31%) with partial regression (PR) (50% or more tumor regression), 12 (17%) with stabilization of disease, and 31 (43%) with progression of the disease. Patients who responded with CR, PR, and stable disease (41 patients) had a median survival of 67 weeks, while those who did not respond (31 patients) had a median survival of 20 weeks (P < .0001). Overall median survival was 31 weeks. The bleomycin-Oncovin-lomustine-DTIC (BOLD) regimen is an effective alternative treatment for metastatic melanoma; there is good tumor response and prolongation of survival in the responding patients. Its overall toxicity is mild to moderate.