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Biomedical subjects

R Schofield

Publications and source records attributed to R Schofield.

At least 19 recordsLinked to original sources

Psychological distress across the course of care: a case study from implantable cardioverter defibrillator to cardiac transplantation evaluation.

The psychological distress of cardiac patients can complicate treatment or the recovery process. This case study presents a 47-year-old male recipient of an implantable cardioverter defibrillator who experienced multiple, consecutive shocks and subsequently developed anxiety and depressive difficulties. Psychological treatment to diminish these symptoms was employed. Despite declining cardiac function, the patient made significant progress in managing this negative affect. Subsequently, he was evaluated for cardiac transplant, and this treatment progress became critical evidence of his psychosocial suitability for transplant.

Defibrillators, Implantable↗

From hospital to community: bridging therapeutic relationships.

The 'Bridge to Discharge' project evolved from a participatory research project. The team included public health nurses, in-patient schizophrenia program nurses and mental health consumers. The project focused on therapeutic relationships and used Peplau's theory of Interpersonal Relations. A broad perspective of therapeutic relationships was used that explicitly included both peer and professional support. The theoretical approach is described and illustrated with a case study.

Continuity of Patient Care↗

Teledermatology--high technology or not?

As an alternative to attending a conventional dermatology clinic, patients had a high-resolution conventional photographic image taken by a professional medical photographer. The photographic images were viewed by a dermatologist together with referral details from the general practitioner and any other relevant information from the patient's notes. From the images, a dermatological diagnosis was derived and a management plan for each patient instituted. After treatment, histological assessment of the tumours allowed diagnostic accuracy to be determined. The preliminary diagnostic accuracy (71%) was greater than that of the referring general practitioners (49%). However, when the diagnostic ability of the method to detect the nature of malignant lesions was examined, telemedicine was able to detect malignancies in 94% of cases compared with only 70% detected by general practitioners. The results of the present study indicate that teledermatology is achievable using a low-technology, low-cost approach.

Humans↗

Empowerment education for individuals with serious mental illness.

1. Traditionally, health education for people who have a serious mental illness has been teacher-driven and illness focused. However, nurses are challenged to shift toward learner-driven and health-focused formats. 2. Through an empowerment education process, a group of people who experience mental illness can find greater meaning in their lives. Increased relationships, more integration with self-chosen work activities, and self-reflection creates a purpose in their lives. 3. An ongoing supportive environment is essential in the journey toward self-responsibility and meaning.

Adult↗

Bridging the discharge process.

Current mental health initiatives are decreasing the number of psychiatric beds and thus increasing the number of clients with serious mental illness who are being served in the community. Such changes have implications for clients' quality of life and health care economics. To implement the changes while addressing the unique needs of psychiatric clients, appropriate models of discharge planning and community integration are critical.

Adult↗

Evaluation of bridging institution and housing--a joint consumer-care provider initiative.

1. The most common alternative housing choice in the community for individuals with serious mental illness was a boarding home. 2. Community consumers noted that being with other people was the most important benefit of the teaching apartment, followed by eating, learning new skills, and entertainment. 3. Although they reported negative aspects about the homes, most consumers did not want to change anything about their boarding home.

Activities of Daily Living↗

Sustained reflow in dogs with coronary thrombosis with K2P, a novel mutant of tissue-plasminogen activator.

Coronary artery reocclusion after thrombolysis with human recombinant tissue-type plasminogen activator (rt-PA) is related to the short half-life of this agent in plasma. K2P, a mutant of rt-PA lacking the fibronectin fingerlike, epidermal growth factor-like and first kringle domains (amino acids 6 to 173) and having the glycosylation site Asn184 mutagenized to Gln, has been produced in Chinese hamster ovary cells. In this study we compared the thrombolytic effect of K2P and rt-PA in dogs with electrically induced coronary artery thrombosis. Both agents were given intravenously in equimolar amounts over 20 min after the occlusive thrombus was stable for 30 min; dogs were monitored for 1 h after reperfusion if flow occurred. Coronary blood flow was restored by rt-PA in 6 (60%) of 10 dogs. The restored flow lasted for 49 +/- 12 min and mean flow at 60 min from the start of reperfusion was 7 +/- 3 ml/min. The reocclusion rate was 50% (three of six dogs). Flow was restored in five (100%) of five dogs by K2P. The restored blood flow lasted during the entire 1-h observation period in all but one dog and mean flow at 60 min was 49 +/- 16 ml/min (p less than 0.02 vs. flow in rt-PA-treated dogs). Restored coronary blood flow showed marked cyclic flow variations in rt-PA-treated but not in K2P-treated dogs.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

TxA2 inhibition and ischemia-induced loss of myocardial function and reactive hyperemia.

To determine the contribution of thromboxane (Tx) A2 release in reperfusion injury, 17 dogs were subjected to total coronary occlusion for 1 h and reperfusion for 1 h. Eleven dogs were treated with saline, and six were treated with selective TxA2 synthetase inhibitor U63,557A (5 mg/kg iv) 30 min before coronary artery occlusion. In all saline-treated dogs, peak reactive hyperemia after 10-s total coronary artery occlusion was diminished (P less than 0.01) after reperfusion. Myocardial segmental shortening was also reduced (9.8 +/- 1.9 to -6.7 +/- 2.0%, P less than 0.01) in the reperfused region. Reperfusion was associated with 737 +/- 343 premature ventricular contractions (PVCs) per hour. Histology revealed extensive myocardial infiltration and capillary plugging by leukocytes in the reperfused region. Myeloperoxidase, an index of leukocyte infiltration, was also increased (P less than 0.02) in the reperfused region. In the U63,557A-treated animals, serum and plasma TxB2 levels were markedly (P less than 0.02) reduced. Decrease in myocardial shortening fraction was less in U63,557A- than in saline-treated animals (P less than 0.05). The frequency of reperfusion PVCs was also significantly reduced (10 +/- 5 PVCs/h, P less than 0.02 compared with saline-treated dogs). However, peak reactive hyperemia was reduced similar to that in saline-treated dogs. Myocardial infiltration and capillary plugging by leukocytes in the reperfused regions was also similar in the U63,557A- and saline-treated dogs. These results indicate that treatment with U63,557A decreases reperfusion arrhythmias and preserves myocardial function. However, coronary reperfusion-induced deterioration in reactive hyperemia is not affected.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

On the late seeding of CFU-S to the spleen: 8- vs 12-day CFU-S.

Marrow from 5-fluorouracil- or cyclophosphamide-treated mice, injected into lethally irradiated recipients, gives an increasing number of spleen colonies between days 7 and 14. It has been suggested that the later-forming colonies result from the more primitive spleen colony-forming units (CFU-S), which first seed into the marrow, only later to be recirculated and form colonies in the spleen. Strontium 89 (89Sr), a bone-seeking radionuclide, was injected into recipient mice to block such putative recirculation. A dose of 89Sr, which killed at least 99.8% of CFU-S in, or entering, the bone cavities, was incapable of preventing the increase in spleen colony numbers. Similarly, the splenic environment, modified by the presence of spleen colonies and able to provide a better bed for trapping CFU-S from the peripheral circulation, yielded the same number of further CFU-S, whether or not the animal had received 89Sr. Thus, it was concluded that the 12-day CFU-S does not seed initially into the marrow spaces. Direct observation of the quality of CFU-S initially seeding into the bone marrow and spleen showed, by retransplantation into secondary irradiated mice, that a similar spectrum of CFU-S types had seeded both organs.

Animals↗

The radiation sensitivity of the haemopoietic microenvironment--effect of dose rate on ectopic ossicle formation.

The haemopoietic microenvironment (HM) consists of a complex mixture of cellular types and extra-cellular matrix. It is essential for prolonged haemopoiesis in both the normal situation and after bone marrow transplantation. The competence of the HM can be assessed by ectopic grafting of femoral marrow. A complete haemopoietic organ develops at the site of implantation. Stem cells (CFU-S) which inhabit the ossicle formed after ectopic implantation can be measured, to assess the function of the engrafted HM to support haemopoiesis. Using this functional endpoint we have examined the radiation sensitivity of the HM at both high and low dose rates, and conclude that high doses of gamma-irradiation delivered at 4 Gy/min or 0.016 Gy/min have widely different effects on the HM, the former proving much more damaging than the latter.

Animals↗

Marrow repopulation in mice treated with busulphan or isopropyl methane sulphonate and bone marrow.

By using karyotypic analysis of female mice treated with busulphan or isopropyl methane sulphonate (IMS), and injected with male bone marrow the donor contribution to both total marrow cellularity and spleen colony forming cells (CFU-S) was assessed for up to 6 months after transplant. In the mice treated with busulphan the marrow cells yielded metaphases of which between 40% and 83% were of donor type. Between 60% and 97% of metaphases in spleen colonies formed in irradiated mice were of donor type during the 24-week study period. In contrast, mice prepared for the transplant with IMS showed no cells of donor type at any time after transplant, neither did they possess CFU-S of donor type. We were therefore led to conclude that the donor cells made no contribution to longterm engraftment in mice prepared with IMS, whilst in those prepared with busulphan they were the predominantly active haemopoietic cells. These results are consistent with a model of haemopoiesis in which the most primitive cells reside in a 'niche' where they are resistant to the effects of IMS but susceptible to the action of busulphan. Busulphan may vacate some niches to allow engraftment by transplanted marrow, whilst IMS yields no unoccupied niches for grafted cells to occupy, and cannot therefore lead to a stable chimaerism.

Alkylating Agents↗

Standardization of procedures for ectopic marrow grafting. II. Influence on recipients of radiation dose and field size.

The ectopic implantation of mouse marrow to the kidney capsule offers considerable scope as an assay of the hemopoietic microenvironment. Our previous work has shown that whole-body irradiation of the graft recipient prior to implantation results in superior ossicle formation in the kidney of the host. Here we report that a range of irradiation doses over a 4-Gy threshold are equivalent with respect to conditioning the graft recipient. We also show that two distinct and separable influences affect graft growth in the irradiated recipient, namely, a local effect brought about in the irradiated kidney (and restricted to it) and secondly, a systemic effect resulting from irradiation of sites other than the kidney, which nevertheless affects ossicle growth in the shielded renal capsule.

Animals↗

Ectopic implantation studies using Sl/Sld marrow and recipients.

Marrow from Sl/Sld mice (in which the hemopoietic stromal microenvironment is defective), when implanted beneath the renal capsule of a normal littermate, produces an ectopic marrow site containing the same number of stem cells (CFU-S) and nearly as many GM-CFC as that obtained by implanting marrow from a normal littermate. On the other hand, a marrow plug from an Sl/Sld donor implanted beneath the renal capsule of an Sl/Sld littermate produces less than half the number of CFU-S and about 10% of the number of GM-CFC. This suggests that the recipient of the ectopic implant can contribute in some way to the stromal environment of the grafted marrow.

Animals↗

Hematopoietic effects of TCNU in mice.

Carmustine has been in clinical use since the 1960s and has proved efficacious in many treatment protocols. It has, however, been limited in its applications because of delayed hematopoietic toxicity which results in curtailment of treatment. A new derivative based on taurine, 1-(2-chloroethyl)-3-/2-(dimethylaminosulfonyl)ethyl-1-nitrosourea, has been developed and we have investigated its effects with a view to assessing the possibility of its being a causative agent for long-term marrow damage. We have found that while this new compound is less hematoxic than carmustine, it still demonstrates significant residual impairment of blood cell formation after application to mice. This impairment is noted in the CFU-S (stem cell) numbers and in the microenvironmental populations responsible for forming an ectopic site of hemopoiesis, persists for at least 180 days after the cessation of treatment, and may therefore be considered irreversible.

Animals↗

Comparison of haemopoiesis in young and old mice.

Haemopoietic status and functions have been compared in young (2-3-month-old) and old (2-2.5-year-old) BDF1 mice. The parameters measured include total marrow cellularity, CFU-S, CFU-mix, GM-CFC, BFU-E and CFU-F. In all cases the numbers of these cells in the femoral marrow of the old mice was equal to or greater than those in the femoral marrow of young mice. In addition to these parameters we have compared the ability of marrow from young and old mice to repopulate the marrow of recipient mice whose marrow had been eliminated by radiation; to grow in long-term bone marrow cultures; to produce ectopic grafts of marrow beneath the renal capsule of normal recipients; and to supply inhibitor and stimulator of stem cell proliferation in the marrow and to resynthesise these substances. We could detect no differences in any of these functions with the exception of that of resynthesis of the stem cell regulator substances, which appears to be somewhat slower in the old mice. This, however, does not impose any limitation upon the ability of the marrow to function either under normal conditions or in conditions requiring rapid proliferation. Therefore we can find no evidence whatsoever to suggest that aging of the haemopoietic system plays any part in aging of the individual or influencing the life-span.

Aging↗

Effects of plutonium-239 on haemopoiesis. I. Quantitative and qualitative changes in CFU-S in different regions of the mouse femur and vertebrae.

Mice were injected with plutonium-239 (960 Bq/mouse) and, over a period of four months, the response of haemopoietic tissue and the self-renewal capacity of its stem cells was monitored. Cellularity, CFU-S concentration and self-renewal capacity were measured in five different regions of bone and marrow--axial and marginal marrow of the femoral shaft, femur shaft, proximal and distal ends of the femur shaft and vertebrae. Cellularities were little affected by plutonium but CFU-S were reduced in all regions, most severely in the bone shaft and marginal marrow due to the initial deposition of plutonium on the bone surface, by four days. The reduction in axial CFU-S, however, was due probably to a relatively long plasma half-life resulting from the tendency of plutonium to combine with plasma proteins. The capacity of CFU-S for self-renewal was reduced and remained low in all zones. Thus, although the highly self-renewing axial CFU-S were depleted, and remained so, due probably to a longer term redistribution of plutonium throughout the marrow, additional proliferation of the more mature CFU-S in the other zones kept their self-renewal low while replenishing their numbers and maintaining a normal cell output.

Alpha Particles↗

Standardization of procedures for ectopic marrow grafting: I. Influence of sex of recipient.

Bone marrow plugs implanted beneath the renal capsule of a normal syngeneic mouse recipient develop, within a few weeks, into a shell of marrow-containing bone. The marrow stromal microenvironment of the implant is reported to be of donor origin and therefore the technique has the potential for development into a quantitative assay of the stroma, or stroma-forming, capacity of the implanted marrow. A surprising difference has been shown, however, in that the female mouse does not permit the development of such an ectopic implant to the same extent as does a male recipient. The suppression of development of the implant is particularly dramatic when marrow from a male donor is implanted into a female recipient, but is strongly operative even upon donor marrow from a syngeneic female. The effect is partly strain dependent, being more pronounced in C57B1/6 and B6D2F1 mice than in DBA/2 or Balb/c. Castration and ovariectomy do not abrogate or modify the suppression. On the other hand, exposure of recipients to 6 Gy 137Cs gamma-radiation before implantation results in bigger implants developing in male recipients, and the suppressive effect of the female recipient upon the graft is reduced considerably or eliminated altogether. Marrow plugs were implanted into chimeras made by transplanting marrow from syngeneic male or female donors, i.e., into heavily irradiated B6D2F1 mice of the same or opposite sex. In female mice repopulated with marrow cells from male donors, the ectopic implants contained 2-3 times as many spleen colony-forming units (CFU-S) as did those in female mice populated by female marrow cells. Ectopic implants into male mice repopulated with female marrow cells contained fewer CFU-S than implants into male recipients having a male marrow, though the differences are smaller than those found in female recipients and may not be significant.

Animals↗