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Biomedical subjects

S McCann

Publications and source records attributed to S McCann.

72 records · Page 4Linked to original sources
PubMed1989

Allogeneic bone marrow transplantation (BMT) for acquired severe aplastic anaemia (SAA) in children.

The SAA Registry of the EBMT now contains data on 171 children younger than 15 years of age with acquired SAA and undergoing BMT between 1970 and 1988. The overall actuarial survival is 63% at 10 years. In a multivariate Cox analysis, the year of transplant was the most important prognostic factor with a significant advantage for children grafted in 1984-88 (81%) vs 1981-83 (67%) and 1970-80 (41%) (p = 0.02). Cyclosporine A given for GVHD prophylaxis, no treatment before transplant and an interval less than 90 days from diagnosis to BMT were all favourable variables in univariate analysis. As regard to transplant procedures, the better results were obtained using Cyclophosphamide and Cyclosporine A (78%) followed by Cyclophosphamide plus irradiation plus Cyclosporine A (77%). Sex, etiology and the severity of the aplasia had no impact on survival in both uni and multivariate analysis.

Adolescent↗
PubMed1988

Bone marrow transplantation (BMT) versus immunosuppression for the treatment of severe aplastic anaemia (SAA): a report of the EBMT SAA working party.

This is an analysis of 509 patients with severe aplastic anaemia (SAA) treated in Europe between 1981 and 1986; 218 patients were treated by allogeneic bone marrow transplantation (BMT) from HLA identical sibling donors and 291 with immunosuppressive therapy (IS) with antilymphocyte globulin (ALG). The overall actuarial survival was 63% after BMT and 61% after IS therapy at 6 years. All patients fulfilled the criteria of SAA; however, most patients with a neutrophil count of less than 0.2 x 10(9)/l also had infections and haemorrhages. Therefore a further subclassification was defined by pretreatment peripheral blood neutrophil count: very severe aplastic anaemia (vSAA) (less than 0.2 x 10(9)/l neutrophils) and moderately severe aplastic anaemia (mSAA) (0.2-0.5 x 10(9)/l neutrophils). A Cox regression analysis showed that the only significant pre-treatment variables were a low neutrophil count (P = 0.001) and increasing age (P = 0.05). Thus it seemed reasonable to analyse survival data after combined stratification for neutrophils (vSAA versus mSAA) and age (cut off at 20 years). BMT was superior to IS in patients with vSAA under 20 years of age (64% v. 38%; P = 0.01). IS was superior to BMT in patients with mSAA aged 20 or more (82% v. 62%; P = 0.002). The two treatments gave comparable results in young patients with mSAA (BMT = 58%, IS = 62%; P = 0.1), and in older patients with vSAA (BMT = 44%, IS = 43%; P = 0.06). Overall 75/218 and 87/291 patients, given BMT or IS respectively, died. The major cause of failure in BMT patients was graft rejection (n = 22) or problems associated with graft-versus-host disease. For ALG patients the major problem was persistence of the aplasia with haemorrhage (n = 32) or infections (n = 46). This study indicates that over 60% of patients with SAA can be successfully treated with either BMT or IS. Overall survival does not differ in the two groups, though significant differences emerge after stratification for severity of the aplasia and age.

Adolescent↗
PubMed1987

Role of opioid peptides in pulsatile release of gonadotropins and prolactin in the rat.

To determine the role of endogenous opioid peptides in the pulsatile release of gonadotropins and prolactin in the ovariectomized rat, the opiate receptor blocker, naloxone, was administered intravenously, and its effect on plasma FSH, LH and prolactin was determined by multiple sampling prior to and after injection. Naloxone produced a dose-related increase in plasma LH and to a lesser extent FSH and decreased prolactin levels in the experiment in which they were examined. Higher doses of naloxone produced a significant increase in plasma LH pulse amplitude and lengthened the interpulse interval with a consequent decrease in pulse frequency. Minimum values between pulses were also increased. There was no clear effect on FSH pulsations but pulses of prolactin were blocked. Intraventricular (third ventricle) injection of a specific anti beta endorphin antiserum (3 microliter) produced an initial decline followed by an elevation of LH but had no effect on plasma FSH. The normal rabbit serum control injections were without effect. It is hypothesized that initiation of LH pulses in the castrated rat may be related to a periodic removal of tonic beta endorphinergic tone.

Animals↗
PubMed1981

Human bone marrow biochemical function and megaloblastic hematopoiesis after nitrous oxide anesthesia.

Prolonged exposure to nitrous oxide (N2O) inhibits bone marrow function. The duration of exposure to nitrous oxide necessary to induce these changes and their permanence is unknown. The possible prophylactic effect of prior treatment with folinic acid has not been examined previously. Bone marrow function in patients receiving nitrous oxide was assessed by the deoxyuridine (dU) suppression test. Morphologic changes in the bone marrow were also studied. One group was exposed for under 6 h, the next for between 12 and 24 h and a control group who received nonitrous oxide. The control group and the short exposure group showed no abnormality of bone marrow function. The long exposure group had abnormal dU supression tests and a megaloblastic hematopoiesis. The changes observed in this group resolved 12 h after discontinuance of the anesthetic. The changes observed could be prevented by the preoperative administration of folinic acid. The absence of either morphologic or dU suppression test abnormalities following N2O anesthesia for periods of less than 6 h confirms the safety of this anesthetic for the majority of operations for which it is used. It has been confirmed that prolonged exposure to the gas causes impaired marrow function which is of a temporary nature and may be prevented by the prior administration of folinic acid.

Anemia, Aplastic↗
PubMed1981

Evidence for a hypothalamic site of action of inhibin to suppress FSH release.

To determine if inhibin has a hypothalamic site of action to suppress FSH release, highly purified inhibin preparations from the rete testis fluid (RTF) of rams were injected into adult male rats which had been orchidectomized (ORDX) 24 hours earlier. Third ventricular (3rd V) injection of a potent inhibin fraction (RTF 38-I) significantly depressed plasma FSH concentrations, without influencing LH, 4-10 h after treatment. A less active preparation of inhibin (RTF 38-II) at the same dose had no effect. A higher dose of another less potent fraction (RTF 1A) significantly reduced FSH 2-6 h following 3rd V administration, accompanied by slight but significant decrements in LH at 2 and 4 only. To determine responsiveness of the pituitary, luteinizing hormone-releasing hormone (LHRH) was injected intravenously at 6 h. It induced similar elevations of FSH and LH in inhibin- and saline-treated groups. Systemic administration of RTF 38-II at a dose 2.5-fold higher than the dose effective centrally failed to modify either FSH or LH levels up to 6 h. These results provide evidence that inhibin from the male can preferentially suppress FSH release by a CNS site of action in addition to its well-known pituitary site of action.

Animals↗
PubMedDate not supplied

Assessment of variables contributing to cyclosporine distribution in blood.

Factors which can account for the poor correlation between whole blood and plasma Cyclosporine (CsA) levels in patients on CsA prophylaxis are evaluated. The study took account of the influence of plasma separation procedures, and the sample haematocrit on CsA distribution in the blood of renal transplant patients (n = 35). CsA was measured using both specific and non-specific CsA radioimmunoassays. Significant negative correlations occurred between CsA distribution and the haematocrit, independently of the plasma separation procedure or the specificity of the assay. All results were lower when using the specific assay but a significantly higher percentage of CsA was measured in the plasma by specific assay compared to nonspecific assay when plasma was separated at both 22 degrees C (t-test, p less than 0.02) and at 37 degrees C, p less than 0.01). This may relate to the selective binding of CsA and its analogues by blood cells. This study is a prelude to the development of more consistent plasma separation procedures in the monitoring of this drug.

Biological Availability↗
PubMedDate not supplied

The management of heart transplant recipients treated with cyclosporine in Ireland: monitoring of cyclosporine concentrations in blood.

Thirty seven cardiac transplants have taken place at the National Cardiac Centre in Ireland since 1985. Data is presented on three still-surviving male patients aged 19 to 42 who received cardiac transplants in 1985 and 1986. Circulating levels of blood cyclosporine were measured by high pressure liquid chromatography and radioimmunoassay; plasma creatinine and bilirubin were also measured. In one of these patients the distribution of cyclosporine in blood was measured by high pressure liquid chromatography in a long term study. For all three patients cyclosporine levels in blood were compared with the daily dose of cyclosporine and biochemical and histopathological parameters.

Adult↗
PubMedDate not supplied

Outcome of bone marrow transplantation in acquired and inherited aplastic anaemia in the Republic of Ireland.

BACKGROUND: Severe Aplastic Anaemia (SAA) and Fanconi Anaemia (FA) are rare haematological disorders characterised by pancytopenia and bone marrow hypoplasia. AIMS: We performed a retrospective study of all patients who underwent BMT for SAA and FA at St James's Hospital, Dublin, and at OLHSC, Crumlin, between 1985 and 2002. METHODS: The medical records of 63 patients, 50 with acquired SAA and 13 with FA, were reviewed. RESULTS: The median age at the time of transplant was 14 years (range 3-43 years). The actuarial survival (OS) (n = 63) was 76% at 17 years. The transplant related mortality (TRM) was 22% (n = 14). The most common cause of death was infection (46%). The survival was significantly better in patients receiving their transplant after 1995 (p = 0.002). Outcome was superior in those receiving less than 20 red cell transfusions prior to transplant: OS 91% (< 20 Units) versus 62% (> or = 20 Units). CONCLUSIONS: These national results are comparable to those of published international series and support the use of BMT in the treatment of SAA and FA. The known adverse effect of prior transfusion was confirmed.

Adolescent↗
PubMedDate not supplied

Fracture blisters: a review of the literature.

Following orthopaedic trauma, fracture blister formation creates a disruption in skin integrity for the injured patient and unique care challenges for the nurse and physician. These blisters may delay surgery, alter the optimum treatment plan, promote wound infection, delay wound healing, and ultimately prolong recovery. This article presents a review of the current literature and includes a discussion of the anatomy of the skin, pathophysiology of fracture blisters, and a review of current research. The complications, prevention, treatment, and implications for nursing care are also examined.

Blister↗