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Biomedical subjects

N A Anderson

Publications and source records attributed to N A Anderson.

At least 19 recordsLinked to original sources
PubMed1997

A prospective randomized study of three types of platelet concentrates in patients with haematological malignancy: corrected platelet count increments and frequency of nonhaemolytic febrile transfusion reactions.

We prospectively randomized 51 patients with haematological malignancy requiring platelet concentrates (PCs) to receive either single donor platelet-pheresis products (SD-PC), PCs made from pooled buffy coats (BC-PC) or pooled units of platelets made by the platelet-rich plasma method (PRP-PC). The leucocyte content of each type of PC was 0.33 (0.03-13.5), 5.68 (0.19-99.0) and 365 (65-910) x 10(6); median (range), respectively; P < 0.0001. All red cell transfusions were leucodepleted by filtration. Statistical comparison of the probability of the occurrence of a nonhaemolytic febrile transfusion reaction (NHFTR) following transfusion of PCs in patients in each group showed a significant decrease for the SD-PC and BC-PC groups (0.031 and 0.038, respectively) when compared with PRP-PC (0.171); P = 0.0001. The actual corrected platelet count increments (CCI) at 1-6 and 18-24 h post-transfusion for all three types of PC did not differ significantly. We conclude that transfusion of PRP-PC is associated with a significant increase in NHFTR.

Adult↗
PubMed1996

Haemolytic disease of the newborn due to anti-G.

Mrs P. presented at 13 weeks of gestation with apparent anti-C+D. At week 34, with antibody levels of 168 IU/ml, a D-negative (r'r) baby was delivered with a strongly positive DAT and an Hb of 3.0 g/dl. Anti-G in maternal serum was isolated by adsorption and elution from R2R2 cells and shown, using flow-cytometric and chemiluminescence assays, to sensitize r'r cells at levels of cell-bound IgG consistent with fetal haemolysis. In an analysis of 28 sera from alloimmunized women with over 5 IU/ml anti-C+D, 2 sera were shown to contain levels of anti-G consistent with moderate or severe haemolytic disease of the newborn (HDN). Thus HDN due to anti-G may not be rare. An analysis of 187,037 blood donors in the south-west of England showed the r' gene frequency to be 0.005897 suggesting that approximately 2.9% of matings of rr women with D-negative fathers can produce an r'r baby. These findings highlight the need for the continuous non-invasive monitoring of D-negative fetuses of women with apparent anti-C+D.

Antibodies, Anti-Idiotypic↗
PubMed1996

Reproducibility of Bayesian belief network assessment of breast fine needle aspirates.

OBJECTIVE: To assess the consistency of diagnosis of fine needle aspiration biopsies of breast lesions by three experienced and five less experienced pathologists using conventional means and applying a Bayesian belief network (BBN) to 10 diagnostic features to support diagnostic decision making. STUDY DESIGN: Forty fine needle aspiration biopsies, previously assessed by one of the experienced pathologists both conventionally and using a BBN, were assessed by two further experienced pathologists and five less experienced pathologists. RESULTS: Using the BBN, the experienced pathologists arrived at diagnoses in agreement with an established consensus at a slightly lower rate than by conventional means. The less experienced pathologists arrived at the correct diagnoses no more frequently with the help of the BBN than conventionally. CONCLUSION: As used in this study, the BBN did not help less experienced pathologists to interpret their observations but did not enable less experienced pathologists to identify how their observations differed and affected their diagnoses. The prototype system used in this study has since been upgraded by providing computer graphic displays of the features to be observed so that a more uniform mental image can be held by the participating pathologists. This will be tested with the same study design.

Biopsy, Needle↗
PubMed1995

Immediate and long-term results following repair of aortic left ventricular discontinuity: a 25-year experience.

From 1967 to 1993, 21 patients underwent surgical repair of aortic left ventricular discontinuity as a result of acute bacterial endocarditis. Repair of the defect between the aorta and left ventricle was usually with interposition of a patch (prosthetic patch or autologous pericardium), using a continuous monofilament suture. Interrupted pledgetted stitches were used when the ventricular tissue appeared friable. A valve prosthesis was then sewn to the patch and remaining annulus. Three patients died in the immediate perioperative period. Long follow-up ranging from 5 to 142 months (mean 36 months) is available on 17 of 18 survivors. There were six deaths in this group from 11 to 142 months (mean 67 months) from initial surgery. Of 11 long-term survivors (5 to 61 months (mean 21 months) after operation), nine have had event-free courses. Two cases of recurrent subacute bacterial endocarditis occurred 3 and 52 months after surgery in patients who were intravenous drug abusers, both of whom were managed medically. It is concluded that while aortic left ventricular discontinuity remains a potentially lethal complication of acute bacterial endocarditis, débridement of infected necrotic tissue, patch repair of the defect, and prosthetic valve replacement offer satisfactory immediate and late results.

Adult↗
PubMed1995

A clinical comparison of the efficacy of an electromechanical flossing device or manual flossing in affecting interproximal gingival bleeding and plaque accumulation.

This one-month clinical trial was designed to compare the effect of an electromechanical flossing device and manual flossing on reducing interproximal gingival bleeding and plaque accumulation in a cohort of 60 healthy adults. After baseline evaluation of interproximal gingival bleeding, soft tissue trauma and plaque, patients were randomly assigned to one of the two experimental groups, given flossing instructions, and had their teeth cleaned. At 30 days all three clinical parameters were again evaluated. The results showed a reduction in GI from baseline to follow-up in each group. This effect is significant (p<0.0001) in the analysis of variance. There was no overall difference in the groups (p=0.93). There was no difference in the reduction in GI from baseline to follow-up between the two groups (p=0.91); interaction). As with the GI, there was a significant reduction in PI from baseline to follow-up in each group (p<0.0001). There was no overall difference between the groups (p=0.24). There was no difference in the reduction in PI from baseline to follow-up between the two groups (p=0.59; interaction). No soft tissue trauma was noted at the baseline examination or at the follow-up examination after 30 days.

Adolescent↗
PubMed1994

Hepatitis C (HCV)-positive blood donors in south-west England: a case control study.

The aim of this study was to compare the socio-demographic characteristics and risk factors in anti-HCV positive blood donors with those of matched controls. The participants were 50 hepatitis C antibody (HCV) positive blood donors and 50 matched blood donors with no evidence of HCV infection, who gave blood to the South Western Transfusion Centre between November 1991 and July 1992. A confidential structured interview was conducted to collect socio-demographic data and to elicit information on risk factors for HCV. Measurements were made of the prevalence of risk factors and socio-demographic characteristics in cases and controls. The main results were that 45 of the 50 cases could have been exposed to HCV by previous intravenous drug abuse (IVDA), blood transfusion or medical employment. Cases were significantly more likely to have a history of IVDA, tattooing or of medical employment than matched controls. Cases with no history of IVDA were significantly more likely to have had a blood transfusion. The key conclusions to emerge are that current policies are ineffective at excluding those with a history of IVDA from the donor pool. Consideration should be given to the introduction of a policy of direct confidential questioning about risk factors for all donors, or, at a minimum, the use of a questionnaire.

Adult↗
PubMed1994

Effectiveness of sealed dental prophylaxis angles inoculated with Bacillus stearothermophilus in preventing leakage.

It was the purpose of this in vitro investigation to evaluate the effectiveness of several brands of sealed, reusable prophylaxis angles to keep internal materials within the internal portions of the head of the prophylaxis angle, and not allowing contaminates to leak out. Three brands of sealed, reusable dental prophylaxis angles were autoclaved and then taken apart under a biocontainment flow hood. Testing conditions were designed to prevent a "worst case scenario" by inoculating dental prophylaxis angles with 10(6) of the heat resistant spores of Bacillus stearothermophilus and 20% bovine serum albumin to simulate the presence of human serum. The concentration of Bacillus stearothermophilus spores was verified before testing procedures were initiated. The internal portions of the sterile prophylaxis angles were inoculated with a 1:1 mixture of the Bacillus stearothermophilus spores and bovine serum albumin, at a concentration of 1.15 x 10(6) spores/inoculation. The prophylaxis angles were reassembled under sterile conditions, and a sterile rubber cup was inserted into each of the prophylaxis angles. The prophylaxis angles were attached to a sterile dental handpiece and then submerged in a 50 ml tube containing sterile trypticase soy broth and run at 3000 rpm for 30 seconds. The tube of medium was incubated for 7 days. No growth of Bacillus stearothermophilus spores could be cultured from one of the brands of prophylaxis angles at any time during the incubation period. The other two brands of prophylaxis angles did produce some leakage of the Bacillus stearothermophilus spores.

Cross Infection↗
PubMed1992

U.K. multicentre study on blood donors for surrogate markers of non-A non-B hepatitis. Part I: Alanine transferase and anti-HBc testing.

Blood samples from 9,215 blood donors in three U.K. centres (North London, Bristol and Manchester) were tested for their alanine aminotransferase (ALT) level and the presence of anti-HBc and anti-HCV. This paper presents the results of the ALT and anti-HBc tests. The prevalence of ALT > 45 IU/l was 3.1% overall (North London 3.06%, Bristol 4.56% and Manchester 1.97%). Manchester results were skewed by the methodology used for ALT measurement, highlighting the need for standard test methods. Anti-HBc was detected using the Wellcome enzyme-immunosorbent assay (EIA) and confirmatory testing was performed using a radioimmunoassay (RIA) and the Corecell haemagglutination assay. Repeat reactive rates were 0.9, 0.79 and 0.94% for North London, Bristol and Manchester, respectively, with an overall rate of 0.9%. The confirmed positive rate was 0.73, 0.53 and 0.65% for the three centres with an overall rate of 0.63%. Donors with an ALT > 45 IU/l, or with confirmed anti-HBc, were interviewed with a medical questionnaire for risk factors. The major contributing factors in donors with a raised ALT were alcohol consumption and obesity.

Adolescent↗
PubMed1991

Comparison of platelet-rich plasma collection using the Haemonetics PCS and Baxter Autopheresis C.

We have compared 118 platelet-rich plasma donations collected using the Autopheresis-C Platelet cell (Auto C) with 166 donations using the Haemonetics PCS. The median platelet yield from the Auto C was superior (2.51 vs. 1.54 x 10(11] although collection times differed (60 vs./40 min). There was greater variability in the platelet yield from the Auto C (0.45-5.6 vs./0.26-2.8 x 10(11], but leucocyte contamination was not significantly different. After secondary processing, there was significantly less residual platelet-poor plasma (272 vs. 369 ml). Platelet function assessed during 5 days of storage was satisfactory for both, although platelet aggregation responses to collagen and adenosine diphosphate were superior in the Auto C platelets.

Humans↗
PubMed1991

Plasma exchange in the treatment of Guillain-Barré syndrome: experience in a sub-regional referral centre.

Plasma exchange became popular in the treatment of Guillain-Barré syndrome with the publication in 1985 of results by the Guillain-Barré Study Group. Since then we have treated 24 patients referred for plasma exchange. We have audited their outcome and compared this with the results of patients in the treatment arm of the USA Study. Our patients were of comparable age and clinical severity and had similar duration of illness before starting plasma exchange. Nine of our patients required ventilation for a median of 24 days. The median time to improve one clinical grade was 19 days which compared well with the Study Group results. We have shown that plasma exchange may be safely performed in a district general hospital in a setting appropriate to the patient's clinical condition. We concur with the central conclusion of the Study, that if treatment is started early in the disease, the patient's outcome is improved.

Adult↗
PubMed1990

Bone marrow processing on the Haemonetics V50 cell separator.

We have processed 27 bone marrow (BM) harvests using the Haemonetics V50 cell separator with a paediatric plasmapheresis set and programmed for lymphocyte collection. The mean starting volume of 843 mL was processed in 6-8 cycles to a buffy coat (BC) with a mean volume of 230 mL. The mean starting mononuclear cell (MNC) count was 1.22 x 10 8/kg recipient weight, and recovery was 92%. Clonogenic potential of the BC was assessed using CFU-GM assays and recovery was measured after cryopreservation or purging. On 4 occasions where major ABO incompatibility existed between donor and recipient, both BM and BC were consecutively diluted in compatible blood and processed twice. This achieved a calculated reduction in donor erythrocytes of 98%. The procedure was efficient and yielded a BC fraction suitable for cryopreservation and purging. Adequate stem-cells were retained as verified by CFU-GM assays and documentation of stable engraftment.

Adolescent↗
PubMed1989

Social network advice during pregnancy: myths, misinformation, and sound counsel.

One hundred eighty-five low-income, inner-city women were interviewed after they gave birth. They were allowed to report on up to 30 members of their social networks, including household members, relatives, and friends. Questions were asked regarding the types and nature of health advice given to them by these individuals, the relationship of each advisor, and his or her age and sex. Respondents received between 0 and 211 (median 20) pieces of advice related to pregnancy health from 0 to 19 (median 5) members of their social networks. Both folk beliefs and information aligned with accepted medical views of health promotion were communicated to individual women. Most advice rendered was sound, but often the rationale for the recommended health action was poorly understood. Some respondents received advice that, if followed, could be harmful to health. This suggests that for some low-income, inner-city women, social networks serve as important resources for health information. However, the advice they convey may cause unnecessary worry or come into conflict with recommendations of health care providers. Therefore, new educational strategies are required to address the informational needs not just of individual women, but of their social networks as well.

Adult↗