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Biomedical subjects

R Rush

Publications and source records attributed to R Rush.

34 records · Page 2Linked to original sources
PubMed1989

The usefulness of dye-penetration studies reexamined.

An in vitro study to determine the usefulness of dye-penetration studies was conducted. In part I, teeth were prepared through the foramen and then left open, either apically, coronally, or at both ends. In all cases, the dye did not penetrate the full length of the canal. The only exception was when both ends were left open and the teeth were placed into the dye in an upright position. In part II, a measurable defect in a canal filling the length of the canal was created and left open apically. When the tooth was immersed in dye, the penetration was incomplete. When the air was removed by vacuum pump prior to placement in the dye, the penetration was total. The validity of dye studies that do not consider entrapped air is open to question.

Coloring Agents↗
PubMed1981

Effect of nerve activity on transport of nerve growth factor and dopamine beta-hydroxylase antibodies in sympathetic neurones.

The effect of nerve activity on the uptake and retrograde transport of nerve growth factor (NGF) and dopamine beta-hydroxylase (DBH) antibodies was studied by injecting 125I-labelled NGF and anti-DBH into the anterior eye chamber of guinea-pigs. Decentralization of the ipsilateral superior cervical ganglion (SCG) had no significant effect on the retrograde transport of either NGF or anti-DBH. Phenoxybenzamine produced a 50% increase in anti-DBH but not NGF accumulation and this effect was prevented by prior decentralization. This demonstrates that NGF is taken up independently of the retrieval of synaptic vesicle components.

Adrenergic Fibers↗
PubMed1977

Involvement of complement in degeneration of sympathetic nerves after administration of antiserum to dopamine beta-hydroxylase.

The involvement of complement in the degeneration of noradrenergic nerves in the guinea-pig iris produced by administration of antibody to dopamine beta-hydroxylase (DBH) in vivo was investigated histochemically. When 500 microliter of antiserum to DBH was injected systemically, no evidence of degeneration was observed in the iris although the noradrenergic supply of the myenteric plexus of the ileum degenerated within 2 days. However, injection of 20 microliter of complement (C) into the anterior chamber of one eye within 2 days of the systemic administration of anti-DBH produced a degeneration of 50--90% of noradrenergic terminals in the iris, the nerves of the iris of the contralateral uninjected eye being unaffected. Electron microscopy confirmed the presence of degenerating nerve terminals in the iris. The extent of degeneration produced by addition of C decreased when C was injected at increasing intervals after the antiserum. Intraocular injection of 5 microliter of anti-DBH together with 20 microliter of C caused a substantial degeneration of noradrenergic nerves in the iris. In contrast, intraocular injection of the Fab'2 fragment of anti-DBH (which did not bind C, but still bound DBH in vitro and in vivo) failed to cause degeneration in the presence of 20 microliter of C. The degeneration of guinea-pig sympathetic nerves caused by antibodies to DBH thus appears to be due to a complement mediated lysis of sympathetic axon membranes. The relative susceptibilities of the noradrenergic fibres in different tissues probably depend on the local concentrations of anti-DBH and C.

Adrenergic Fibers↗
PubMed1977

A method for measurement of fibrin monomer with the use of an immune precipitate of fibrinogen.

A semiquantitative test for measuring fibrin monomer in human plasma is described. The test is based upon the ability of fibrin monomer to form a complex with an immune precipitate of fibrinogen. The test is not sensitive to the plasmin digestion products of fibrinogen and relatively insensitive to plasmin digestion products of fibrin. The test is easily performed on small quantities of plasma in approximately 2 hours.

Adolescent↗
PubMed1971

Detection of intravascular coagulation.

A method is described for the measurement of soluble thrombin-altered fibrinogen (circulating fibrin) in human plasma. This method is dependent upon the enzymatic incorporation of glycine ethyl ester-(14)C (GEE-(14)C) into circulating fibrin by the action of the fibrin-stabilizing enzyme, factor XIII. The mean incorporation of GEE-(14)C into the fibrinogen of normal human plasma controls was 167 +/-47 dpm/mg fibrinogen. The addition of 0.03 NIH U/ml of thrombin to normal human plasma resulted in a two to threefold increase in the incorporation of GEE-(14)C into the fibrinogen. The addition of plasmin split products of fibrinogen to normal plasma did not increase the incorporation of GEE-(14)C unless these products were also exposed to thrombin. The addition of plasmin split products of a fibrin clot resulted in only minimal increase in the incorporation of GEE-(14)C (57 dpm/mg fibrinogen) at 37.5% concentration. The method was therefore sensitive to thrombin alterations of fibrinogen but insensitive to plasmin alterations of fibrinogen and fibrin.Clinically, the method was found to provide useful information for the diagnosis and treatment of disseminated intravascular coagulation in two patients with meningococcemia, two patients with Rocky Mountain spotted fever, and three patients in whom therapeutic abortions were induced by the injection of hypertonic saline.

Abortion, Therapeutic↗
PubMedDate not supplied

Psychosocial effects of living with an increased risk of breast cancer: an exploratory study using telephone focus groups.

Research to date has mainly focused on the short-term psychological impact of genetic risk counselling for breast cancer. This study aimed to explore the long-term consequences for women of being informed about an increased risk of breast cancer in terms of: the effect on their everyday lives, their coping strategies and their unmet needs in terms of the current service. The participants were 25 women with a family history of breast cancer who had received genetic risk counselling and had consequently been receiving clinical surveillance for at least 2 years. They took part in one of seven telephone focus groups and subsequently completed a feedback questionnaire. Transcripts of the focus groups were qualitatively analysed by three independent researchers with inter-rater agreement between pairs of raters ranging from Kappa = 0.61-0.79. Six key issues emerged from the data, which provide an important insight into the long-term consequences of living with an increased risk of breast cancer concerning: (1) psychological adaptation, (2) behavioural adaptation, (3) family issues, (4) clinical surveillance, (5) provision of information, and (6) peer support. These findings, together with the quantitative results of the feedback questionnaire, have clinical implications that require further investigation in larger scale quantitative research.

Adaptation, Psychological↗
PubMedDate not supplied

Prophylactic oophorectomy versus screening: psychosocial outcomes in women at increased risk of ovarian cancer.

This study investigated the psychosocial outcome of prophylactic oophorectomy versus regular screening in women at increased risk of ovarian cancer. Women who had undergone prophylactic oophorectomy (n=29) were compared with women who remained on the ovarian screening programme (n=28). Assessments were made retrospectively by postal questionnaire. The surgical group showed significantly poorer functioning on two sub-scales of the Short Form (SF)-36 Health Status Questionnaire (role-emotional (p=0.04) and social functioning (p=0.01)), and there was a trend (p=0.06) for them to report more menopausal symptoms. General Health Questionnaire (GHQ) scores were significantly higher (p=0.03) in the surgical group. There were no significant differences between the groups for cancer worry or sexual functioning. Experience of the operation was better (p=0.01) and incidence of self-reported post-operative problems was lower (p=0.02) for women who had undergone the 'keyhole' rather than an 'open' procedure. Being pre-menopausal at the time of surgery predicted higher GHQ (p=0.04) and longer subjective recovery time (p=0.04). Women who have undergone prophylactic oophorectomy may have more physical and emotional symptoms than women who remain on an ovarian cancer screening programme, and may report equivalent levels of cancer worry. Those who are pre-menopausal at the time of the operation may be particularly vulnerable to psychological distress and take longer to recover post-operatively. A larger prospective study is needed to evaluate the casual versus causal role of oophorectomy in these findings, and the extent to which it allays patients' fear of cancer.

Body Image↗
PubMedDate not supplied

Thromboembolic complications in thermally injured patients.

The frequency of thromboembolic complications in burn patients has been estimated to range from 0.4% to 7%. The clinical significance of these events is often debated and has prompted some centers to adopt the routine prophylactic use of low dose heparin prophylaxis. A 10 year review of 2,103 burn patients treated at this institution was undertaken. Twenty-five (1.2%) patients, with a mean age of 40.0 years and an average burn size of 49.3% total body surface area (TBSA), were identified as having significant pulmonary thromboembolism (PTE). In only 3 (0.14%) patients was the thromboembolism considered to be a cause of death. Nineteen (0.9%) patients, with an average age of 36.7 years and a mean burn size of 48.3% TBSA, developed clinically evident deep venous thrombosis (DVT); however, in only 1 (0.05%) patient did the disease progress to fatal PTE. A review of the literature reveals a 0.6% to 5% incidence of complications related to low dose heparin therapy which includes bleeding, thrombocytopenia, and arterial thrombosis. We feel that the infrequency of clinically significant PTE and DVT in burn patients and the comparable or greater rate of complications associated with heparin prophylaxis mitigate against the routine use of low dose heparin therapy except in patients at high risk for these events.

Adolescent↗
PubMedDate not supplied

The influence of the renin angiotensin system on abnormal expression of nerve growth factor in the spontaneously hypertensive rat.

1. The levels of the neurotrophic factor, nerve growth factor (NGF) in the mesenteric vascular bed of the spontaneously hypertensive rat (SHR) were greater than those in the corresponding vascular bed of normotensive Wistar-Kyoto rats (WKY). 2. Administration of angiotensin II (200 ng/kg per min, by minipump) for 2 weeks to juvenile WKY rats increased the levels of NGF in the mesenteric vasculature to those seen in untreated SHR. 3. Administration of the angiotensin II receptor antagonists losartan (30 mg/kg per day, p.o.) or PD144277 (10 mg/kg per day, p.o.) to juvenile SHR for 4 weeks reduced the levels of NGF such that they were indistinguishable from the values obtained for normotensive WKY rats. 4. The results confirm the elevated level of NGF in the mesenteric vasculature of the SHR and suggest that angiotensin II may play a role in regulating the abnormal concentrations of the protein in this tissue.

Angiotensin II↗