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Biomedical subjects

D Saunders

Publications and source records attributed to D Saunders.

At least 109 records · Page 6Linked to original sources
PubMed1982

Cross-linked [DAlaA1]Insulins. Evidence for a change in the conformation of the insulin monomer at its receptor.

[(Boc-DAla)2A1,B1]Insulin was produced by reaction of insulin with phenylisothiocyanate, protection of the B29-epsilon-amino function with the Msc residue, Edman degradation, reaction of A2 and B2 with Boc-DAla-ONSu, and removal of the Msc group. This derivative was used to prepare [DAla2A1,B1]insulin, a B29-B29' dimer, and N alpha A1, N epsilon B29-diaminosuberoyl-[DAla2 A1,B1]-insulin. These derivatives had lipogenic potencies similar to those already reported for analogous derivatives of native insulin (87%, 2.8%, and 8.7% respectively). This suggests that the low activities observed for A1-B29 cross-linked insulins is not due to perturbation of the N-terminus of the A chain. It is argued that the hindrance of a slight conformational adjustment involving the C-terminus of the B chain by the cross-link is a more likely explanation.

Animals↗
PubMed1980

Covalent linking of photoreactive insulin to adipocytes produces a prolonged signal.

The first step of insulin's many cellular functions is specific binding to receptors on the plasma membrane of target cells. The subsequent molecular basis of insulin action, particularly the coupling mechanism(s) involved in transmitting the biological message, remains largely unknown. Our approach to the problem centres on the application of a series of well characterized photo-insulins carrying an aryl-azido or nitro-aryl-azido group in positions A1, B1, B2 or B29 (refs 2--4). Specific binding to membrane components could be demonstrated with B1-, B29- (ref. 5) and A1-photo-insulins as well as a B2-derivative. We now report that lipogenesis is increased to, and maintained at, near-maximal levels for several hours after photoinduced covalent binding of B2- (2-nitro,4-azidophenylacetyl)-des-PheB1-insulin (Napa-DP-insulin) to living adipocytes.

Adipose Tissue↗
PubMed1979

Life stresses and depression in the menopause.

Research on the climacteric has largely concentrated on relationships between ovarian insufficiency, oestrogen deficiency, and climacteric symptoms. Little attention has been paid to those who have no symptoms. It is proposed, in addition to these relationships, that the life events of this period are significantly involved; and that resultant stress may contribute to oestrogen deficiency as opposed to physiologically normal postmenopausal oestrogen levels. In this preliminary study, two groups of women under conditions of relatively low stress and high stress were tested over a period of 15 mth. They were rated on the Hamilton Rating Scale for depression and anxiety and results were compared with the corresponding total urinary oestrogen output. The results, which suggest a significant relationship between stress related to depression and oestrogen levels in the menopause, are discussed and compared with differing life circumstances of the subjects.

Anxiety↗
PubMed1977

The re-estimation of absorbed doses of less than 1 rad measured with lithium fluoride thermoluminescent dosemeters.

The technique of ultraviolet light bleaching for the re-estimation of the absorbed dose of radiation received by lithium fluoride thermoluminescence dosemeters has been extended to the extruded ribbon and PTFE disc form of dosemeter. The threshold of detection for the re-estimation of absorbed dose was found to be 1-1 rad for the PTFE disc dosemeters and 2-8 rad for the extruded ribbon dosemeters. A further study of this technique has revealed that by raising the temperature of the dosemeter during bleaching the threshold for re-estimated absorbed doses may be substantially reduced. The optimum temperature was found to be 80 degrees C and the practical threshold for the re-estimation of absorbed dose using a PTFE disc dosemeter was determined as 750 mrad.

Evaluation Studies as Topic↗
PubMedDate not supplied

Biological action and fate of photoaffinity-labelled insulin-receptor complexes.

Covalent linking of two photoactivatable insulin derivatives, B2-(2-nitro,4-azidophenylacetyl)-des-PheB1-insulin and B29-(2-nitro,4-azidophenylacetyl)-insulin to viable rat adipocytes gives a system, which contains a fixed stoichiometry between hormone and receptor. The biological signal of prolonged lipogenesis has been used to study several aspects of insulin binding and action: the role of the site of the crosslink between insulin and receptor, recognition of bound photoinsulin by anti-insulin antibodies, the half-life of the biologically active complex, the pH-dependence of the biological signal, and the possible role of internalization. Furthermore, the effect of trypsin on the insulin receptor, as well as the insulin-receptor complex, has been investigated and a refined model of the receptor is presented.

Adipose Tissue↗
PubMedDate not supplied

The Injured Workers Survey: development and clinical use of a psychosocial screening tool for patients with hand injuries.

Hand therapists often recognize that their patients are experiencing psychosocial distress following traumatic hand injury but may lack the time and training to determine whether referral for psychological assessment and treatment is warranted. The Injured Workers Survey (IWS) is a brief, effective self-report tool that screens for psychosocial distress, in particular for characteristic symptoms of post-traumatic stress disorder (PTSD). It also collects clinically relevant information about other psychosocial issues that have a major effect on treatment outcomes. A recent research study has validated the IWS as a screen for PTSD and supports its routine use in the initial assessment of all patients with traumatic hand injuries. To the extent that psychosocial distress interferes with recovery, its early identification and treatment can optimize overall treatment outcomes and facilitate successful in return to work.

Hand Injuries↗
PubMedDate not supplied

Hypnosis in a case of long-standing idiopathic itch.

OBJECTIVE: This article presents the results of a brief hypnosis treatment of a woman with chronic, idiopathic vaginal and anal itch. METHODS: The patient was referred after 3 years of unsuccessful outcomes with standard topical and oral treatments prescribed by her family physician and three dermatologists. Treatment consisted of five sessions of self-hypnosis training in techniques of relaxation, deepening, and imagery, and home practice with an individualized instructional tape. RESULTS: After treatment, the patient reported substantial tissue healing, confirmed by her treating physician, that coincided with significant reductions in her scores of itch intensity, itch-related sleep disruption, and distress from pre- to posttreatment. These improvements continued at 4 months of follow-up, and the patient reported complete resolution of physical symptoms. CONCLUSIONS: The fact that these changes coincided with only minor improvements in general anxiety scores suggests that the resolution of the patient's itch condition was treatment-specific rather than the result of methodological artifact, participant reporting bias, or a general sense of feeling better. These findings suggest that hypnosis is a cost-effective treatment for idiopathic itch conditions, especially those that are unresponsive to standard medical treatments.

Adult↗