Separation of a phenol carboxylating organism from a two-member, strict anaerobic co-culture.

In a culture converting phenol to benzoic acid under anaerobic conditions and previously described as being constituted of only a Clostridium-like strain 6, another bacterium (strain 7) was observed. Each organism was enriched by centrifugation on a Percoll gradient. Strain 6 was purified by dilution and plating. Strain 7 did not grow on solid media, but a strain 7 culture, cleared of strain 6, was obtained by subculturing in the presence of ampicillin and by dilution. In fresh medium, phenol was transformed by the reconstituted co-culture but not by each strain alone. In a supernatant from a co-culture or from a strain 6 culture, strain 7 alone transformed phenol but not strain 6. Maintenance of an active strain 7 in fresh medium instead of co-culture supernatant became possible when phenol was replaced by 4-hydroxybenzoate (4-OHB), which is decarboxylated to phenol before being transformed to benzoate. Even with 4-OHB, the use of co-culture (or strain 6 culture) supernatant resulted in faster transformation activity and growth rate. A phylogenetic analysis placed strain 7 in a cluster of uncultivated or nonisolated bacteria (92-96% homology). Strain 7 is also related to Desulfotomaculum, Desulfitobacterium, Desulfosporosinus, Moorella, and Sporotomaculum genera (87-92% homology).

Migrants and HIV / AIDS.

PIP: This paper outlines some of the imperatives that should drive attention to the rights of legal and illegal migrants to health, particularly in relation to HIV/AIDS. It is noted that migrants can be especially vulnerable to HIV/AIDS/sexually transmitted diseases (STDs), but they are often excluded or simply missed in many prevention and care programs. In terms of the effects of globalization, it would seem that governments are required to ensure that this state of affairs does not continue. Evidence indicates that human rights and other ethical violations are occurring and need to be urgently addressed at local, national and international levels. In view of such, it is recommended that HIV/AIDS/STD prevention and care programs for migrant populations should be developed with and guided by migrant communities, and involving substantial community mobilization. Although some progress in preventing the spread of HIV to and from migrants have been documented, and projects addressing their needs have been made accessible, the challenge of dealing more comprehensively the complex issues involved still remains.^ieng

A genetic selection for isolating cDNAs encoding secreted proteins.

We describe a simple, rapid technique for simultaneously isolating large numbers of cDNAs encoding secreted proteins. The technique makes use of a facile genetic selection performed in a strain of Saccharomyces cerevisiae deleted for its endogenous invertase gene. A cDNA cloning vector which carries a modified invertase gene lacking its leader sequence is used in conjunction with this strain. Heterologous secreted genes fused appropriately upstream of this defective invertase provide the necessary signals to restore secretion, allowing the yeast to grow on sugars such as sucrose or raffinose. This microbial growth selection facilitates scanning cDNA libraries containing millions of clones, enabling the wholesale identification of novel secreted proteins without the need for specific bioassays. The technique is similar to one previously described (Klein et al. (1996) Proc. Natl. Acad. Sci. USA 93, 7108-7113). We describe results using a cDNA library derived from activated human peripheral blood mononuclear cells (PBMC). Genes identified from this library encoded signal sequences of proteins of diverse structure, function, and cellular location such as cytokines, type 1 and type 2 transmembrane proteins, and proteins found in intracellular organelles. In addition, a number of novel secreted proteins were identified, including a chemokine and a novel G-protein-coupled receptor. Since signal sequences possess features conserved throughout evolution, the procedure can be used to isolate genes encoding secreted proteins from both eukaryotes and prokaryotes.

Transdermal testosterone administration in hypogonadal men: comparison of pharmacokinetics at different sites of application and at the first and fifth days of application.

In this study of 13 hypogonadal men (25-69 years of age), three open-label, randomized treatments were administered to determine the pharmacokinetics of serum testosterone after application of an investigational testosterone transdermal system to the upper buttocks, upper arm, and back. Testosterone in vivo input kinetics profiles were estimated by DeMonS, a recently developed numerical deconvolution method for estimating drug absorption at different time intervals and/or drug disposition model parameters, and compared on the first and fifth days of system application. Area under the concentration-time curve from 0 to 27 hours (AUC0-27) values for testosterone after one-day applications to the upper buttocks, upper arm, and back were 9,560 ng.hr/dL, 8,651 ng.hr/dL, and 8,988 ng.hr/dL, respectively. Maximum observed concentration (Cmax) values were 482 ng/dL, 462 ng/dL, and 499 ng/dL, respectively. Serum testosterone concentrations were equivalent to each other, and Cmax values fell within the normal range. No drug accumulation was seen with repeated dosing over 5 days.

Environmental health issues in prisoner of war camps.

Maintaining adequate environmental health and sanitation conditions in prisoner of war camps is essential for the fulfillment of our international legal obligations under the Geneva Conventions. Insights from Desert Storm and other conflicts are discussed.

The Southampton Wave.

The course planning team at Southampton University College of Midwifery wanted to offer a diploma course which reflected the realities of midwifery education in the clinical setting. For this a curriculum model--The Wave--was developed. The Wave is not a static model, but reflects the changes a midwifery curriculum must absorb in context and circumstances. Allocation of students to clinical areas is linked with course content, allowing direct application of theory to practice and practice to theory.

HIV/AIDS and school boards: a policy approach.

In general, there is a low incidence of HIV infection in members of school communities. Moreover, all available evidence supports the conclusion that HIV is not transmitted by the everyday contacts which occur in family, social, employment and educational settings. Despite this, the presence, in a school community, of persons infected with HIV or who have an HIV related disease have been perceived by some as presenting a threat to their children's, and even to their own health and well-being, which, in turn, has led to serious conflicts between various participants in that community. Experience, however, has shown that the fears of many persons and the risks of conflict and confrontation can be minimized, if not negated, if a school board has adopted policies and procedures in relation to HIV/AIDS. Such policies and procedures must be based on current medical knowledge and clearly identified ethical and legal principles, including identification of the rights, interests and needs of all persons and development of appropriate analyses, especially where these are required to resolve conflicts. In this text, educational authorities and their advisors are provided both with a comprehensive model HIV/AIDS policy, and a commentary which examines, amongst other matters, the fundamental ethical and legal considerations which have guided its formulation and the justifications for each of the principles contained therein.

Suppression of IgE synthesis in vitro by allogeneic T cells from atopic and non-atopic subjects.

The role of T cells in the regulation of IgE synthesis by human PBMC was studied. PBMC or separated and recombined populations of T and B cells from both normal and atopic donors were cultured for 10 days with and without cycloheximide. IgE and IgG synthesis were determined by specific RIA. IgE synthesis was detected in 0/30 non-atopic, 6/34 mildly atopic and 25/31 severely atopic subjects. Autologous T cells from 10/26 atopic donors, whose B cells synthesised IgE, significantly suppressed this IgE synthesis. The addition of allogeneic T cells from atopic or non-atopic subjects to atopic B cells resulted in greater suppression of IgE synthesis than the addition of autologous T cells. These data support the notion that atopic subjects have naturally occurring IgE isotype-specific suppressor T cells as well as suppressor T cells which can be activated during incubation with alloantigen.

Immunoregulation in juvenile chronic arthritis.

The presence of hyperimmunoglobulinaemia and antinuclear antibodies in patients with juvenile chronic arthritis (JCA) suggests a possible role for immunoregulatory abnormalities in the pathogenesis of the disease. This is further supported by the demonstration in the sera of such patients of an autoantibody active against a suppressor inducer T cell subset. To identify immunoregulatory defects in JCA, a method of measuring concanavalin A (Con A)-inducible lymphocyte suppression of IgG production in vitro has been established. Peripheral blood mononuclear cells were cultured in the presence of either medium alone, pokeweed mitogen (PWM), Con A, or PWM together with Con A. IgG present in culture supernates at 8 days was measured by a double-antibody radioimmunoassay. Spontaneous IgG synthesis by lymphocytes by both patients and child controls was found to be more than double that of lymphocytes from adult control subjects. However, lymphocytes of children (patients or controls) did not show stimulation of IgG production in the presence of PWM. Con A-induced suppression of spontaneous IgG synthesis was reduced compared to adult controls in both patients (p less than 0.02) and child controls (p less than 0.05). Con A-induced suppression of IgG synthesis in the presence of PWM was also reduced compared to adult controls in both patients (p less than 0.01) and child controls (p less than 0.01) but was also reduced in the patient group compared to the child controls (p less than 0.01). Thus, spontaneous IgG synthesis in children is increased compared to adults, and IgG-producing cells appear less subject to regulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Glucocorticosteroid enhancement of immunoglobulin synthesis by pokeweed mitogen-stimulated human lymphocytes. III. Common variable immunodeficiency.

We studied the effect of glucocorticosteroids (GCS) on IgG synthesis by peripheral blood mononuclear cells from 19 patients with common variable immunodeficiency (CVID). Purified T and B lymphocyte subpopulations from patients and normal subjects were recombined at various T : B ratios and cultured for 8 days unstimulated, stimulated with pokeweed mitogen (PWM) and in the presence of prednisolone. IgG synthesis was measured in the culture supernatants by radioimmunoassay. Enhancement of PWM-stimulated IgG synthesis by prednisolone at high T : B ratios was found in nine patients, four of whom produced negligible amounts of IgG with PWM alone. In four patients, enhancement by prednisolone of IgG synthesis by purified B lymphocytes was noted. In three out of eight patients whose IgG synthesis was increased by normal allogeneic T lymphocytes with PWM and prednisolone, negligible amounts of IgG were produced by similarly treated autologous combinations. T lymphocytes from CVID patients provided less help compared with normal T lymphocytes for IgG synthesis by normal B lymphocytes at high T : B ratios even in the presence of prednisolone. GCS in vitro enhance IgG synthesis by lymphocytes from some but not all patients with CVID by a mechanism which appears independent of GCS action on regulatory T lymphocytes.

Glucocorticosteroid enhancement of immunoglobulin synthesis by pokeweed mitogen-stimulated human lymphocytes.

We studied the role of the T lymphocyte in GCS enhancement of PWM-stimulated IgG synthesis by human peripheral blood mononuclear cells. Purified T or B lymphocyte subpopulations were pretreated with 10(-6) M prednisolone or recombined at various T:B ratios and 10(-6) M prednisolone was added. PWM-stimulated IgG synthesis was measured in the culture supernatants at 8 days by radioimmunoassay. Addition of prednisolone to cultures of autologous and allogeneic reconstituted mixtures of T and B lymphocytes resulted in enhancement of PWM-stimulated IgG synthesis. This effect was observed with constant and increasing numbers of lymphocytes in culture, independent of T:B ratio and occurred with purified B lymphocytes containing monocytes. Pretreatment of purified B lymphocytes containing monocytes but not purified T lymphocytes with prednisolone enhanced PWM-stimulated IgG synthesis in reconstituted mixtures of T and B lymphocytes. We propose that GCS enhancement of PWM-stimulated IgG synthesis by human mononuclear cells is independent of T lymphocyte regulation.

Corticosteroid enhancement of immunoglobulin synthesis by pokeweed mitogen-stimulated human lymphocytes.

The effects of the addition in vitro of corticosteroid on pokeweed mitogen (PWM) induced Ig synthesis by human peripheral blood lymphocytes were studied. IgG in supernatants produced under standardized culture conditions was measured by double antibody radioimmunoassay. The addition of 10(-6)M prednisolone caused a remarkable enhancement of PWM-stimulated IgG synthesis beginning at day 4 of culture and increasing at a faster rate than that in cultures with PWM alone. 10(-6)M prednisolone resulted in a geometric mean enhancement of 5.6-fold of PWM-stimulated IgG synthesis in all twenty-five normal controls studied. This enhancement occurred up to 3 days after the addition of PWM. 10(-6)M and 10(-5)M prednisolone resulted in significantly greater enhancement of PWM-stimulated IgG synthesis than 10(-7)M prednisolone. Hydrocortisone, prednisolone, methylprednisolone, betamethasone and dexamethasone at 10(-6)M were all equally effective in the enhancement of PWM-induced IgG synthesis.