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Biomedical subjects

K G Patterson

Publications and source records attributed to K G Patterson.

At least 19 recordsLinked to original sources
PubMed1995

Hepatitis B transmission from contaminated cryopreservation tank.

Over a 25-month period, six multiply transfused patients undergoing cytotoxic treatment for haematological or other malignant disorders developed icteric acute hepatitis B virus (HBV) infection. Bone marrow or peripheral-blood stem cells had been harvested from all six patients and stored in the same cryopreservation tank for possible future transplantation. Human DNA, HBsAg, and HBV DNA with sequences identical to those from four patients with related infections were subsequently found in the liquid nitrogen. Leakage of the cryopreservation bags used to store bone marrow harvested from the first patient when acutely infected with HBV led to contamination of the tank and its contents with HBV and subsequent transmission to patients after transplantation. This incident emphasises the continuing need to screen donors of tissue to be cryopreserved for bloodborne virus infections. It also reinforces the requirement for primary containers used to cryopreserve human tissue to be sealed in a way which prevents exchange of material between the specimen and the liquid nitrogen.

Acute Disease↗
PubMed1995

Two-centre evaluation of the Abbott CD3500 blood counter.

The CD3500 blood counter (Abbott Laboratories) is a 33 parameter fully automated blood counter that produces a five part differential count with flagging of leucocyte abnormalities. In this evaluation excellent correlation between CD3500 and Coulter STKR blood counter was found for all red cell and platelet parameters on the 221 samples tested. Studies of carryover, mixing efficiency and precision also gave excellent results. There was a good correlation with manual 400 cell differential counts for neutrophils, lymphocytes, monocytes and eosinophils for the 468 samples compared. Correlation of CD3500 and manual basophil counts was poor. Normal samples stored at 4 degrees C and analysed while cold showed satisfactory stability for WBC, RBC, Hb, MCV and platelets for 48 h and a stable differential for 24 h. Correlation with the differential count produced by the Coulter STKS showed good correlation for neutrophils, lymphocytes, monocytes and eosinophils; correlation with STKS basophils was poor. False positive flagging rate varied between 8.9% (Band and/or IG) and 0.9% (NRBC) depending on the nature of the flag; 5.8% of samples exhibited two or more false positive flags. No significant breakdowns were encountered during the period of the evaluation. The scatterplot displays of laser light scatter produced by the instrument provide an interesting adjunct to conventional morphology.

Blood Cell Count↗
PubMed1993

Life-threatening thrombotic and haemorrhagic problems associated with silent myeloproliferative disorders.

Myeloproliferative disorders are well recognized as being associated with haemorrhage and thrombosis. We describe two cases, one of life-threatening haemorrhage and the other of thrombosis, in patients with normal peripheral blood counts and films, both of whom went on to develop overt manifestations of myeloproliferative disorders (CGL and essential thrombocythaemia) more than a year after their first presentation.

Adult↗
PubMed1992

Granulocyte-macrophage colony-stimulating factor induces neutrophil adhesion to pulmonary vascular endothelium in vivo: role of beta 2 integrins.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) causes upregulation of neutrophil surface CD11b/CD18 expression, and enhances the adhesion of neutrophils to cultured human endothelial cells in vitro. Systemic administration of GM-CSF results in a rapid, transient decrease in circulating phagocyte numbers. Using a nonhuman primate model (Cynomolgus), we provide histologic evidence that this transient leukopenia is associated with the margination of neutrophils in the pulmonary microcirculation. In four animals receiving 2 to 15 micrograms/kg recombinant human GM-CSF (rhGM-CSF), light microscopic sections of lung contained 36 +/- 8, 17 +/- 7, 21 +/- 6, and 15 +/- 8 (mean +/- SD, n = 20) neutrophils within a graticule grid, as compared with two control animals receiving saline injections whose lung sections contained 2.1 +/- 1.6 and 3.1 +/- 2.1 (mean +/- SD, n = 20) neutrophils within the same grid. Scanning electron microscopy shows activated leukocytes adherent to pulmonary vascular endothelium, but no morphologic evidence of endothelial damage, and no migration of cells into the extravascular space. Margination is associated with an increase in surface expression of CD11b/CD18 on circulating phagocytes, which could contribute to the adhesion to capillary endothelial cells, but CD11b/CD18 levels remain elevated even when demargination is complete. In vitro, monoclonal antibodies (MoAbs) to CD18 and CD11b were able to inhibit neutrophil aggregation and adhesion to endothelium. FMLP-induced neutrophil aggregation was inhibited by 39.8% +/- 11.5% and 44.8% +/- 12.3%, respectively, by MoAbs to CD18 and CD11b (P less than .0005, n = 4 for both); a similar effect was demonstrated on TPA-induced aggregation. MoAb CD18 reduced the adhesion of unstimulated neutrophils to endothelium by 44% (P less than .01, n = 7), and inhibited the amount of GM-CSF-stimulated adhesion by 74% (P less than .001, n = 7), while MoAb to CD11b produced a reduction of unstimulated neutrophil adhesion by 30%, and of GM-CSF-stimulated adhesion by 40% (P less than .01, n = 5, for both). However, when administered in vivo, MoAb CD18 produced only a small, albeit significant, amelioration of GM-CSF-induced margination in vivo, while MoAb CD11b was without effect. These results show that GM-CSF-induced transient leukopenia is associated with enhanced neutrophil adherence to pulmonary vascular endothelium, but suggest that the beta 2 leukocyte integrins CD11/CD18 play only a minor role in this process.

Antibodies, Monoclonal↗
PubMed1992

The use of radioisotopes in haematology.

Radioisotopes used in haematology may be divided into four groups: 1. those used for in vivo studies, involving the labelling of cells in the blood or bone marrow and the use of labelled plasma albumin; 2. investigations involving surface counting over organs such as the bone marrow, spleen, liver and heart; 3. in vitro use of radioisotopes in the haematology laboratory and 4. isotopes used as part of imaging procedures. The shorter the half life of the isotope, the more limited patient exposure to radioactivity will be, but the greater the problems of starting and completing the investigation before the isotope has decayed. Isotopes studies should not be carried out in children or pregnancy unless there are exceptional clinical indications.

Absorption↗
PubMed1992

Mini-BEAM followed by BEAM and ABMT for very poor risk Hodgkin's disease.

High dose chemotherapy and autologous bone marrow transplantation (ABMT) is an effective form of salvage therapy in patients with relapsed or resistant Hodgkin's disease. Patients with large tumour masses at the time of ABMT have a poorer prognosis and we have therefore administered intermediate dose BCNU, etoposide, cytarabine and melphalan (mini-BEAM) prior to high dose therapy with the same agents (BEAM) and ABMT in such patients. In addition we have used the same strategy in patients with bone marrow infiltration at the time of relapse in an attempt to clear the bone marrow for transplant. A total of 23 patients received mini-BEAM and 21 proceeded to BEAM and ABMT. Platelet engraftment was delayed compared to BEAM recipients who had not received mini-BEAM (P = 0.008) but there was only one procedure related death. Responses to BEAM and ABMT were not predicted by the response to mini-BEAM indicating a dose response effect at the upper end of the dose intensity spectrum. At 2 years, the overall survival and progression free survival are 61% and 46% respectively for this group of Hodgkin's patients with extremely poor prognosis.

Adult↗
PubMed1992

The effect of macrophage colony-stimulating factor on haemopoietic recovery after autologous bone marrow transplantation.

Macrophage colony-stimulating factor (M-CSF) is active in the late stages of monocyte maturation, activates mature monocyte-macrophages and enhances their production of various other cytokines. We have examined the effects of a 21 d course of escalating doses of M-CSF purified from human urine (hM-CSF) on recovery following autologous bone marrow transplantation (ABMT) in 20 patients with malignant lymphomas. Four patients were treated at each dose level of 4, 8, 16, 32 and 64 x 10(6) U/m2/d and results compared to 46 concurrent controls. There was no significant difference in recovery to an absolute neutrophil count (ANC) of 0.5 x 10(9)/l (median 20 d in hM-CSF group versus 22 in controls) or in recovery of platelets to 50 x 10(9)/l (32 d versus 39 d, 0.05 less than P less than 0.1); hM-CSF patients received a median of 81 platelet units following ABMT (controls 112 units, P = NS). hM-CSF patients had a median of 5.5 d with fever greater than 37.5 degrees C (control 8, P = NS), received parenteral antibiotics for 14.5 d (control 17, P = NS) and had a 50% incidence of bacteraemia (control 48%). hM-CSF treated patients were discharged by a median of day 29 following transplantation (control 33, P less than 0.05). Platelet and neutrophil recovery correlated significantly with the number of marrow mononuclear cells (MNC) reinfused in the hM-CSF group (P = 0.05 and P = 0.014 respectively) but not in controls. Subgroup analysis showed that hM-CSF patients receiving greater than 2 x 10(8) MNC/kg body weight reached an ANC of 0.5 x 10(9)/l by a median of day 16.5 (control 18.5, NS), became platelet transfusion independent by day 17 (control 29, P less than 0.05) and reached a platelet count of 50 x 10(9)/l by day 21 (control 40, P less than 0.05). No significant toxicity attributable to hM-CSF treatment was seen. These results suggest that hM-CSF accelerates platelet recovery following ABMT and that relatively large marrow innocula are required to see this effect.

Adult↗
PubMed1991

Liposomal amphotericin B (AmBisome) in the treatment of fungal infections in neutropenic patients.

The use of high-dose chemotherapy and the subsequent prolonged neutropenia in patients with haematological diseases has resulted in an increased incidence of fungal infections. The diagnosis and treatment of these infections in neutropenic patients pose major therapeutic problems. The only drug with proven efficacy in the treatment of deep-seated fungal infections, including invasive aspergillosis, is amphotericin B. Unfortunately, this drug has adverse side effects, most importantly dose-dependent nephrotoxicity; furthermore, some patients fail to show a response to amphotericin B. We have treated 20 patients undergoing myeloablative chemotherapy and/or bone marrow transplantation for haematological diseases with liposomal amphotericin (AmBisome) for proven or suspected aspergillosis. Eighteen patients had diffuse interstitial pneumonitis and two patients had suspected fungal liver abscesses. Five patients had mycologically proven fungal infection and of these, three patients (60%) showed a complete response to liposomal amphotericin. Eleven patients received liposomal amphotericin because of the failure of conventional amphotericin B to eradicate proven or suspected fungal infection. Five of these 11 patients (45%) showed a complete clinical response to liposomal amphotericin. Eight patients received liposomal amphotericin because of pre-existing renal impairment or nephrotoxicity caused by conventional amphotericin B. Four of these patients (50%) showed a response to liposomal amphotericin. Recovery from probable fungal infection in this group of patients occurred when there was complete remission of underlying disease and recovery of neutrophil counts, when they were concurrently treated with liposomal amphotericin.

Adolescent↗
PubMed1991

Measurement of haematological indices of chronic rheumatic disease with two newer generation automated systems, the H1 and H6000 (Technicon).

Two automated counters, the H1 (Technicon) and the H6000 (Technicon), which count 10,000 cells per sample, were compared and used to examine the clinical relevance of the additional haematological information now provided to the rheumatologist in three groups of patients--38 with rheumatoid arthritis (RA), 41 with ankylosing spondylitis (AS), and 35 with systemic lupus erythematosus (SLE). The two machines agreed in their estimations of the main indices (haemoglobin, red blood cell count, and white blood cell count), but estimations of platelet count and volume were significantly lower on the H6000 machine, as were mean cell haemoglobin and monocyte count, whereas packed cell volume and red cell distribution width were higher. As expected, both machines identified pancytopenia among the group with SLE, while low haemoglobin and high platelet count were found particularly among patients with RA and AS respectively. Additional information available from these counters showed marked variability in red cell size in SLE, and also of haemoglobin content, which is only measured on the newer H1 machine. Flags for microcythaemia, anisochromasis, and white cell noise (usually due to nucleated red cells) were all more common in SLE. Interpretation of results was complicated by the inevitable difference in age and sex distribution among the disease groups, and identification of active disease was also limited by the effect of drugs. In conclusion, the increasingly widespread use of automated counters as part of the routine haematological service may provide the rheumatologist with useful information, but, as always, care should be taken in the interpretation of indices in patients receiving non-steroidal or second line agents, and also in extrapolating results from one machine to another when they are updated or when patients are monitored at more than one centre.

Adolescent↗
PubMed1990

High-dose chemotherapy and autologous bone marrow transplantation in acute myeloid leukemia.

For younger patients with acute myeloid leukemia (AML), an allogeneic transplant from a matched sibling may afford the best chance of cure. In patients who are older or without a matched sibling donor, dose intensification can be achieved with an autologous bone marrow transplant (ABMT). We report here the results of a high-dose chemotherapy regime with nonpurged ABMT in 82 adult patients in first remission of AML with a median follow-up of 31 months. The median age was 40 years (range 16 to 57 years). The median interval between remission and ABMT was 5 months (range 1 to 12 months). Twenty-eight of these patients received a second course of the same high-dose chemotherapy and ABMT. The procedure related mortality rate was 6%. The projected leukemia-free survival (LFS) at 5 years is 48% for all 82 patients and 50% for the 76 patients with no known preceding myelodysplastic syndrome. For those patients with primary AML who received a double ABMT the projected LFS is 67%. The interval between remission and ABMT did not predict for either relapse or LFS. ABMT using a multidrug chemotherapy protocol is less toxic than allogeneic BMT yet results in a similar LFS.

Adolescent↗
PubMed1989

An evaluation of the Coulter VCS differential counter.

An evaluation of the Coulter VCS (volume, conductivity, light scatter) automated differential counter demonstrated satisfactory correlations with manual 800-cell differential counts for neutrophils, lymphocytes, monocytes and eosinophils. For the detection of abnormal cells, 12.2% of samples gave false-negative results on the VCS, and 13.4% gave false-positive results. However, only 0.8% of the false-negatives would be expected to be picked up by a standard 100-cell manual differential count. Carry-over accorded to manufacturer's specifications and throughput was 60 samples/h. Reference normal ranges have been established and the instrument's precision and performance with leucopenic and neonatal blood samples assessed.

Adult↗
PubMed1989

Detection of important abnormalities of the differential count using the Coulter STKR blood counter.

An assessment of the three part differential provided by the Coulter STKR blood counter showed good correlation when compared with an 800 cell manual differential. Satisfactory flagging of eosinophilia, basophilia, and the presence of immature cells was found. The use of variables derived from the STKR in conjunction with interpretive reporting and user-defined flagging enabled this department to reduce considerably the numbers of films requiring manual differential counts.

Blood Cell Count↗
PubMed1982

Effect of surgery on monocyte function.

In vitro monocyte lysozyme production (IVMLP) was assessed in 10 male patients preoperatively and at intervals postoperatively. A similar procedure was carried out in 6 sex- and age-matched controls. In contrast to the control group where the IVMLP was constant, the IVLMP levels in the surgical group showed a marked increase at 6-10 h postoperatively, falling to control levels after 10 days. In addition, peripheral monocyte counts were carried out using a Technicon Hemalog D counter which produces accurate reproducible counts for cells such as monocytes which occur at low frequency. The peripheral monocyte counts were stable in the control group, whilst in the surgical patients there were significantly higher readings at 36-48 h, which persisted for up to 10 days compared with preoperative counts. This study suggests that surgery has both a qualitative (IVMLP) and quantitative (monocyte counts) effect on the mononuclear phagocytes. These data may be relevant when considering factors that influence the early stages of wound healing.

Adolescent↗
PubMed1982

Bone marrow processing and cryopreservation.

Three different closed procedures for concentrating bone marrow progenitor cells prior to cryopreservation have been compared. These were by a manual double centrifugation method, a Hemonetics 30 cell separator and an Aminco Celltrifuge. The best results were achieved using the paediatric pheresis set on the Hemonetics model 30. Marrow was frozen in 120 ml aliquots in a programmed freezer with rapid cooling of the freezing chamber during the phase change from the liquid to the solid state. After freeze-thawing the average nucleated cell recovery was approximately 50% and the progenitor cell recovery 80%.

Bone Marrow Cells↗