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Biomedical subjects

M Pitman

Publications and source records attributed to M Pitman.

15 recordsLinked to original sources
PubMed2004

LIF receptor signaling modulates neural stem cell renewal.

Activation of the leukemia inhibitory factor (LIF) receptor has been reported to promote gliogenesis and also to support neural stem cell (NSC) renewal. To investigate this paradox, we isolated NSCs and generated neurospheres from embryonic mice either wild-type, heterozygous, or homozygous null for LIF receptor (LIFR)-beta. Exogenous LIF abrogated neurosphere formation and promoted expression of GFAP by all cells in wild-type and heterozygous cultures. LIF also stimulated a twofold increase in the number of multipotential clones generated from these cultures in comparison with those pretreated with EGF and FGF-2 (E+F) alone. In contrast, the clonogenicity of low-density cultures of LIFR knockout cells was reduced in comparison with that of wild-type cells grown in E+F and was unaffected by LIF. Thus, although LIFR signaling is not necessary for NSC self-renewal, it enhances both the clonogenicity and the expression of GFAP by these multipotential cells.

Animals↗
PubMed2001

Irreducible subjectivity and interactionism: a critique.

The authors offer a critique of the privileging of subjectivity in psychoanalysis characteristic of what Hanly has called interactionism, with specific reference to the work of Renik. First, Renik's argument for the irreducible subjectivity of the analyst is explored and critiqued from a philosophical perspective. The need for and plausibility of a subtler notion of objectivity that takes into account the limitations of human subjectivity and that analysts can meaningfully pursue is defended. Second, Renik's 're-visioning' of psychoanalysis, which follows from his notion of irreducible subjectivity, is explored and critiqued. Renik's view of enactments is contrasted with a 'totalistic' perspective of countertransference that allows for important, finer conceptual distinctions. Renik's conceptualisation of countertransference enactments is characterised as a 'special case' of countertransference as a vice. Next, Renik's view of transference is critiqued for privileging the adaptive dimensions of transference, and for potentially sidelining archaic dimensions. Finally, Renik's conclusions and 're-visioning' of psychoanalysis are shown to follow from his modifying or jettisoning certain features of the analytic situation and process. These features and their implications are elaborated on. The conclusion outlines the extent to which the arguments presented can be extended to other advocates of interactionism.

Ego↗
PubMed1998

The treatment of isolated articular cartilage lesions in the young individual.

The treatment of isolated articular cartilage defects is an evolving field in orthopaedic surgery today. We have summarized the basic science and clinical date on the treatment of isolated articular cartilage defects. Further long-term controlled studies are required in order to compare definitively the efficacy of treatments in this difficult clinical area. In future studies, inclusion/exclusion criteria must be detailed, and classification systems need to be standardized Comparative analysis can then be performed to assess the efficacy of various techniques.

Adolescent↗
PubMed1996

Analysis of the sugar specificity and molecular location of the beta-glucan-binding lectin site of complement receptor type 3 (CD11b/CD18).

Zymosan, the cell wall from Saccharomyces cerevisiae, was reported to be a macrophage activator through its beta-glucan over 30 yr ago. Nevertheless, the identity of the beta-glucan receptor has been controversial. This study showed that the alpha M beta 2-integrin, CR3 (Mac-1, CD11b/CD18) served as the beta-glucan receptor through one or more lectin sites located outside of the CD11b I-domain that contains the binding sites for iC3b, ICAM-1, and fibrinogen. Sugar specificity, analyzed with FITC-labeled soluble polysaccharides and flow cytometry, showed CR3-specific staining with several pure beta-glucans but not with alpha-mannan. However, a 10-kDa soluble zymosan polysaccharide (SZP) with high affinity (6.7 x 10(-8) M) for CR3 consisted largely of mannose and approximately 5% glucose. Binding of either SZP-FITC or beta-glucan-FITC to CR3 was blocked not only by pure beta-glucans from yeast, mushroom, seaweed, or barley, but also by N-acetyl-D-glucosamine (NADG), alpha- or beta-methylmannoside, and alpha- or beta-methyl-glucoside. SZP-FITC and beta-glucan-FITC stained all leukocyte types similarly to anti-CR3-FITC, and polysaccharide-FITC staining was inhibited > or = 95% by unlabeled anti-CR3. SZP-FITC staining of cells expressing recombinant chimeras between CR3 and CR4 (p150,95, CD11c/CD18) suggested that both the divalent cation-binding region of CD11b and the region C-terminal to it may regulate binding of polysaccharides to CR3. Unlabeled SZP or beta-glucan also blocked CR3 staining by 11 mAb to C-terminal domain epitopes of CD11b but had no effect on staining by mAb directed to the I-domain. In conclusion, CR3 serves as the leukocyte beta-glucan receptor through a cation-independent lectin site located C-terminal to the I-domain of CD11b. Its sugar specificity is broader than originally appreciated, allowing it to react with certain polysaccharides containing mannose or NADG, as well as glucose.

Animals↗
PubMed1994

Coping with change in public health medicine in the 1990s.

Investigates the effect of change, both structural and in process, in the NHS with regard to the capacity of public health doctors and dentists in the South Western Regional Health Authority to cope with the inherent stresses. Sixty-three public health doctors and dentists were asked to fill in a questionnaire. Satisfaction was expressed most with factors intrinsic to the job (41%) followed by the role in the organization (24%), relationships at work (21%), career development (8%), and organizational structure and climate (6%). Dissatisfaction was identified with factors related to organizational structure and climate (32%), factors intrinsic to the job (30%), the role in the organization (18%), career development (14%) and relationships at work (6%). Overall there was much more dissatisfaction than satisfaction with organizational structure and climate and career development than with the other factors. Improvements suggested included more support staff and improved training. Joint problem solving sessions with managers to identify what is required to co-ordinate the work of both, and the use of time management techniques might be helpful.

Adult↗
PubMed1991

Entrapment of an accessory superficial peroneal sensory nerve.

A 29 year old man had an accessory branch of the superficial peroneal nerve which entered the foot by rostro-caudally traversing the lateral malleolus laterally. The nerve was entrapped by a fascial band, resulting in pain over the lateral malleolus and dorsum of foot. Symptoms resolved when the nerve was surgically released.

Adult↗
PubMed1990

A biomechanical study of tendon adhesion reduction using a biodegradable barrier in a rabbit model.

Adhesion formation associated with tendon surgery is a widespread problem in which a healing tendon becomes adherent via scar tissue to surrounding structures such as bone, muscle, skin, tendon sheath, or other tendons. A model is described in which adhesions were generated reproducibly between the plantaris and Achilles tendons of the rabbit using a partial tenotomy, a Bunnel suture, and immobilization. Using this model, the effect of an absorbable barrier, INTERCEED (TC7), on adhesion formation was investigated. This material, which is a fabric comprised of oxidized regenerated cellulose, was found to diminish significantly the extent and severity of intertendinous adhesions, assessed both mechanically and histologically. No evidence of a foreign body reaction was observed.

Animals↗
PubMed1989

Lower extremity fractures: relationship to reaction time and coordination time.

The purpose of this study was to examine the possible relationship between delayed reaction time and slow coordination time as a contributing factor to lower extremity fracture. A simple reaction time tester and hand coordination tester were used to assess the relative times of reaction and coordination. Subjects were also questioned concerning their daily activity levels. A definite relationship was observed to exist between the times recorded and lower extremity fractures: subjects with lower extremity fractures exhibited delayed reaction times and longer coordination times. Moreover, shorter reaction times and coordination times were seen in those subjects who reported higher activity levels. Statistical analysis was performed on selected data which show an association of fracture with reaction time.

Adolescent↗