Search PubMed⌕ Search

Biomedical subjects

T G Murrell

Publications and source records attributed to T G Murrell.

At least 19 recordsLinked to original sources
PubMed1995

The potential for oxytocin (OT) to prevent breast cancer: a hypothesis.

This hypothesis proposes that carcinogens in the breast are generated by the action of superoxide free radicals released when acinal gland distension, under the influence of unopposed prolactin, causes microvessel ischaemia. Inadequate nipple care in the at-risk years leads to ductal obstruction preventing the elimination of carcinogens from the breast. The regular production of oxytocin (OT) from nipple stimulation would cause contraction of the myoepithelial cells, relieving acinal gland distension and aiding the active elimination of carcinogenic fluid from the breast. Mechanical breast pump stimulation causes an increase in plasma OT levels in the luteal but not in the follicular phase of the menstrual cycle. OT production upon nipple stimulation in the luteal phase of premenopausal, non-lactating women may be protective against the high rates of mitotic breast cell division noted at this time via the potential to block the effect of oestrogen. The epidemiology of breast cancer suggests that lengthy lactation time is beneficial. Sexual activity in nulliparous women also protects and OT levels have been shown to rise with orgasm in women and in men. OT systems in the brain are intricately linked to oestrogen and progesterone levels, and it is possible that these hormones may modify the OT secretory response both centrally and through an effect on the sensitivity of the breast. OT production with nipple care and in sex and lactation, and the reduction in cycling ovarian hormones that occurs with pregnancy, may all be important preventative factors in the development of breast cancer both pre- and post-menopausally.

Breast Neoplasms↗
PubMed1995

Process and outcomes in general practice consultations: problems in defining high quality care.

In order to explore the relationships between the verbal interactions of the consultation and several outcomes (patient health change, patient compliance and the satisfaction of both doctor and patient), 21 General Practitioners contributed ten audiotaped consultations each, from consecutive consenting adult patients. The effects of GP sex and postgraduate training were also investigated, but were found to be minimal. Patient health change was most clearly related to acuteness of symptoms at presentation, whereas reported compliance was predicted by patient satisfaction after the consultation. Different consultations were maximally satisfying for doctors and for patients, and patient and doctor satisfaction with specific consultations showed little correlation. This result implies that the measurement of quality of care, in general practice at least, is a more complex task than has been assumed, and in turn raises issues about whose definition of outcome is relevant in discussing quality of care.

Adolescent↗
PubMed1995

The usefulness of distinguishing different types of general practice consultation, or are needed skills always the same?

We hypothesized that it might be important to distinguish different types of consultation in order to understand better how help is delivered in general practice. This paper provides preliminary data on the ways that consultations can differ in how they unfold, and on how such differences might affect the helping process and the outcomes of each consultation. Several types of general practice consultation were noticed amongst 210 transcripts. Having established adequate inter-rater reliability of the classification system, we explored the differences between consultations of three broad types: Psychosocial, Complex, and Straightforward. Some of the questions asked in this preliminary study included: 1) do certain sorts of doctor, or patient, engage in certain sorts of consultation? 2) are there any relationships between the type of consultation and its length, patient-centredness or outcomes? 3) are the correlations between process and outcome clearer within categories of consultation than they are if consultations are treated as homogeneous? Findings provide a foundation for further investigations.

Clinical Competence↗
PubMed1994

Sudden infant death syndrome (SIDS): are common bacterial toxins responsible, and do they have a vaccine potential?

Despite extensive research, no unifying concept has satisfactorily explained the cause of the sudden infant death syndrome (SIDS). The details are briefly outlined of some of the evidence supporting the hypothesis that common bacterial toxins are important in the aetiology of SIDS. These bacterial toxins act as triggers to initiate a biochemical cascade resulting in death. Data from four research groups, each working independently, indicated that the bacteria Clostridium perfringens, Escherichia coli, Staphylococcus aureus, Streptococcus spp. and Enterococcus spp. were present in higher numbers in infants who had suffered SIDS than in control infants. Certainly more detailed studies need to be performed on the role of bacterial infections in infants. There are many implications arising from this work, particularly the use of vaccination as a means of reducing infections, and consequently the number of SIDS deaths.

Bacterial Toxins↗
PubMed1992

Verbal interactions in general practice. Information, support and doctor satisfaction.

OBJECTIVE: The general practice encounter can be seen as an exchange of information aimed at relief of the patient's presenting symptoms, and it is acknowledged that this goal can most effectively be achieved within the context of the professional's emotional support of the patient. We sought to describe the processes of information exchange and emotional support in detail, and to explore any differences in the speech pattern which were related to the doctors' lesser satisfaction with some consultations. DESIGN: Transcripts of general practice consultations (n = 143) from five medical practitioners were coded and analysed. MAIN OUTCOME MEASURES: The verbal interactions of the consultation were described in categories: for doctors, emotional support, informational support, and diagnostic activity; and for patients, relationship oriented and task oriented. Doctors also rated their satisfaction with each consultation. RESULTS: About two-thirds of the speech by both parties was found to be devoted to information exchange in the forms of diagnosis and medical advice, and the rest to the relationship between the participants. Doctors' satisfaction ratings (extremely satisfactory or otherwise) could be predicted from speech and activity variables by means of logistic regression. CONCLUSIONS: This study describes the verbal interaction which is the vehicle for medical helping in general practice, and it forms a foundation for needed research on how certain features of the verbal interaction are related to quality of care.

Adult↗
PubMed1991

Epidemiological and biochemical support for a theory on the cause and prevention of breast cancer.

Damage to the breast epithelium by chemical carcinogens as products of oxygen free radical release can lead to fibroblast proliferation, hyperplasia of epithelium, cellular atypia and breast cancer. Chemical carcinogens may accumulate in breast fluid in the non-lactating breast consequent to superoxide free radical production which occurs via the adenosine triphosphate (ATP) hypoxanthine pathway. This pathway is initiated by hypoxia of local tissue. Under hypoxic conditions ATP is broken down to form hypoxanthine. Hypoxanthine itself is broken down to produce xanthine and then uric acid. This results in the production of superoxide free radicals, the products of which are carcinogenic. The development of localized hypoxia, which is central to this hypothesis, is caused by acinal gland distention from fluid secreted by raised prolactin levels in the absence of oxytocin. Stimulation of the nipple in a non-lactating breast may raise plasma oxytocin and lower plasma prolactin levels. Contraction of the myoepithelial cells of the breast under the influence of oxytocin would relieve distention of the acinal glands and thus reduce hypoxia and the generation of lipid peroxidoses as products of free radical damage. The epidemiology of breast fibrosis and cancer support the notion that lack of nipple stimulation over time may be a significant variable. A review of this literature linked with current biochemical work on fibrosis and carcinogenesis suggest that draining the breasts of the products of superoxide free-radical release by the encouragement of regular nipple erections may prevent such breast disease.

Breast↗
PubMed1991

Speech patterns and satisfaction in diagnostic and prescriptive stages of general practice consultations.

With a general goal of establishing indicators of the quality of the helping relationship within medical consultations, we recorded and analysed verbal interactions in general practice consultations, in two studies. The diagnostic and prescriptive stages of the consultation were analysed separately, first with doctor satisfaction as the outcome and then, with a second sample of doctors, with both doctor and patient satisfaction as outcomes. Patients and doctors were found to have somewhat different views of what made a highly satisfactory consultation. The most satisfying consultations for doctors were those in which the medical problem and its solution seemed clear; patients felt most satisfied with consultations where they had discussed their own experiences and opinions during the second, prescriptive stage of the consultation.

Consumer Behavior↗
PubMed1991

Signs, symptoms, and the new descriptors.

Data from 143 consultations in general practice were assessed by factors relevant to the four-category descriptive system developed by the Royal Australian College of General Practitioners. It seems that there is no relationship between consultation length, apparent symptom seriousness or the occurrence of a physical examination. Suggestions are offered for improving the clarity of consultation descriptor categories.

Diagnosis↗
PubMed1990

Multiple sclerosis--one manifestation of neurobrucellosis?

There is good geographic evidence that an environmental factor is implicated in the aetiology of multiple sclerosis (MS). Controversy surrounds the interpretation of many studies supporting notions on whether the disease has greater prevalence in urban or rural communities. Rather than focus on residence at birth, in teenage years or at the time of study, analyses of MS mortality by occupation and a case control study to define exposure to animal farm products is thought to shed light in this controversy. The conclusion reached from the results of these studies is that exposure to farm animals or raw products is a common denominator in the aetiology of MS. A literature search for references of zoonotic disease with neurological symptoms produced a range of papers on brucellosis. A study of the literature on neurobrucellosis supports the hypothesis on clinical grounds. Finally, blood serum studies of Brucella exposure in a series of MS subjects and controls is described. These epidemiological studies support the hypothesis, that central nervous system involvement from exposure to brucellosis, may present with the features of multiple sclerosis.

Brucellosis↗
PubMed1990

The reducible risks of sudden infant death syndrome (SIDS).

The general practitioner rarely encounters a case of SIDS in practice. However, every young parent fears such a tragedy. The authors explore known risks for a SIDS death which are reducible. In particular, the infant between 2 and 4 months of age is at greatest risk from factors relating to poverty and seasonality. Counselling parents about such risks is an important role for the general practitioner.

Cause of Death↗
PubMed1990

The role of the GP in the management of chronic disease. Diabetes as a model.

Chronic disease is increasing as a percentage of all illnesses in Australia's health care system, in part because of the ageing of the population. New strategies are required to help manage these often incurable diseases. The general practitioner is well equipped to provide management expertise for chronic disease, provided he or she has access to community based allied health professionals.

Chronic Disease↗
PubMed1987

A hypothesis concerning Clostridium perfringens type A enterotoxin (CPE) and sudden infant death syndrome (SIDS).

This study identifies the presence of Clostridium perfringens type A enterotoxin (CPE) in some gastrointestinal and serum samples from babies who had died of the Sudden Infant Death Syndrome (SIDS) and other causes. On occasion antibodies to this toxin were identified in sera. CPE is parasympathomimetic in its action. In the adult food poisoning model it is produced when the organism sporulates in vivo. This leads to speculation as to whether this toxin may play an ante-mortem role in the dying process of infants, either in the agonal stages or as a causative factor in SIDS.

Bacterial Toxins↗
PubMed1986

A review of the sheep-multiple sclerosis connection.

This paper reviews a notion that the prevalence of multiple sclerosis is high in global areas where sheep populations are concentrated. Pilot studies are reported to serum antibodies in humans to three sheep diseases; focal symmetrical encephalomalacia (FSE), maedi visna and sarcocystis. In MS patients and controls antibodies were not found to the epsilon neurotoxin of the FSE organism, Clostridium welchii type D and to a caprine retrovirus that is closely related to maedi-visna virus. However, 34% of MS and control patients had antibodies to the protozoan parasite Sarcocystis spp., tissue cysts of which contain a powerful neurotoxin, sarcocystin. It is suggested that epidemiological MS prevalence rates for country areas of southern Australia require further study along with an examination for the prevalence of MS in vegetarians.

Adult↗