Cloning and sequencing of Pseudomonas genes determining sodium dodecyl sulfate biodegradation.

The nucleotide sequences of two genes involved in sodium dodecyl sulfate (SDS) degradation, by Pseudomonas, have been determined. One of these, sdsA, codes for an alkyl sulfatase (58,957 Da) and has similarity (31.8% identity over a 201-amino acid stretch) to the N terminus of a predicted protein of unknown function from Mycobacterium tuberculosis. The other gene, sdsB, codes for a positive activator protein (33,600 Da) that has extensive similarity with the lysR family of helix-turn-helix DNA-binding activator proteins.     

Immunologic studies with LFA-1- and Mo1-deficient lymphocytes from a patient with recurrent bacterial infections

A patient and his parents, deficient for lymphocyte function associated antigen-1 (LFA-1) and Mo1 (OKM1), were studied with respect to leukocyte surface marker expression and functional properties. The patient had a history of severe recurrent bacterial infections. Two siblings had already died of bacterial infections. The patient's granulocytes, monocytes, and lymphocytes expressed low but detectable amounts (less than or equal to 10%) of LFA-1 and Mo1. Intracellularly, LFA-1 and Mo1 (OKM1) were detectable and LFA-1 expression was enhanced on patient T cells stimulated with phytohemagglutinin. Granulocytes and monocytes of both the patient's parents expressed markedly decreased amounts of LFA-1 and Mo1. Lymphocytes of the mother expressed 40 to 60% of the amount of LFA-1 expressed on control lymphocytes, but his father's lymphocytes showed a normal LFA-1 expression. Granulocytes of the patient and of his deceased sister showed normal phagocytosis, but they had a dysfunction in the activation of the oxidative metabolism. Functional activities mediated by patient T cells were all normal. Moreover, all lymphocyte functions, including killer (K), natural killer (NK), cytotoxic T cell activity, helper activity for in vitro immunoglobulin (Ig) production by normal B cells, and PHA-induced proliferation were inhibitable by anti-LFA-1 monoclonal antibodies. K and NK activity mediated by patient leukocytes was 100-fold more sensitive to the inhibiting effect of anti-LFA-1 antibody than K and NK activity of normal donor leukocytes. Thus, although the amount of LFA-1 expressed was strongly reduced, it was still sufficient and required for the functional activity exhibited by patient T cells. The major functional defect observed with leukocytes of the patient and his father was an apparent B cell defect. B cells of the father and of the patient failed to produce Ig in the pokeweed mitogen (PWM)-driven system. The B cells of patient and of his father only produced Ig when cultured with T cells of the father, and not with normal donor T cells or T cells of the mother, in the presence of exogenous interleukin 2 (IL 2). In addition, the father's B cells produced Ig when cocultivated with patient T cells in the IL 2-driven system. This restriction of helper T cell activity is noteworthy because PWM- and IL 2-driven Ig synthesis by normal lymphocytes show no histocompatibility requirements between cooperating T and non-T cell populations.(ABSTRACT TRUNCATED AT 400 WORDS)     

Comparison of dot blot with in-situ hybridization for the detection of Neisseria gonorrhoeae in urethral exudate

Dot blot hybridization and in-situ hybridization with DNA probes prepared from total genomic gonococcal DNA were compared with Gram staining and culturing for the detection of gonococci in urethral exudates. Fifteen of 60 patients were positive by at least one of the four methods. Gram staining and in-situ hybridization scored best with 13 positives but culture and dot blot hybridization yielded only 10 and 9 positives respectively. The failure to detect gonococci in culture can be explained by overgrowth in one case and possibly self medication with ampicillin before culture in another. The in-situ hybridization test is a fast and sensitive hybridization method for the detection of gonococci in urethral exudate from men.     

The Facilitating Role of Chemotherapy in the Palliative Phase of Cancer: Qualitative Interviews with Advanced Cancer Patients

Objective

To explore the extent to which patients have a directing role in decisions about chemotherapy in the palliative phase of cancer and (want to) anticipate on the last stage of life.

Design

Qualitative interview study.

Methods

In depth-interviews with 15 patients with advanced colorectal or breast cancer at the medical oncology department in a Dutch teaching hospital; interviews were analysed following the principles of thematic content-analysis.

Results

All patients reported to know that the chemotherapy they received was with palliative intent. Most of them did not express the wish for information about (other) treatment options and put great trust in their physicians’ treatment advice. The more patients were aware of the severity of their disease, the more they seemed to ‘live their life’ in the present and enjoy things besides having cancer. Such living in the present seemed to be facilitated by the use of chemotherapy. Patients often considered the ‘chemotherapy-free period’ more stressful than periods when receiving chemotherapy despite their generally improved physical condition. Chemotherapy (regardless of side-effects) seemed to shift patients’ attention away from the approaching last stage of life. Interestingly, although patients often discussed advance care planning, they were reluctant to bring on end-of-life issues that bothered them at that specific moment. Expressing real interest in people ‘as a person’ was considered an important element of appropriate care.

Conclusions

Fearing their approaching death, patients deliberately focus on living in the present. Active (chemotherapy) treatment facilitates this focus, regardless of the perceived side-effects. However, if anxiety for what lies ahead is the underlying reason for treatment, efforts should be made in assisting patients to find other ways to cope with this fear. Simultaneously, such an approach may reduce the use of burdensome and sometimes costly treatment in the last stage of life.     

Stem cells: The root of all cells

The plant basic body plan is laid down during embryogenesis. All post-embryonic development has its origin in the stem cells located in niches in the heart of the shoot and root meristems. Creating the root niche requires auxin dependent patterning cues that provide positional information in combination with parallel inputs to specify and maintain the root stem cell niche from embryogenesis onwards. Once established, the architecture of the root niche differs from that in the shoot but recent findings reveal a conserved module for stem cell control. Important for stem cell maintenance is the balance between cell division and differentiation. Dealing with the environment is the biggest challenge for plants and that includes complete regeneration of stem cell systems upon damage. Here we will address these issues as we follow the formation, function and maintenance of the root stem cell niche during development.