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Biomedical subjects

L Wood

Publications and source records attributed to L Wood.

At least 181 records · Page 10Linked to original sources
PubMed1987

Lack of short-term effects on the donor during continuous-flow selective mononuclear cell collection.

In 50 individuals, intensive harvesting of relatively pure mononuclear cell fractions from the peripheral circulation was carried out in 195 procedures. Serial collections from bone marrow donors (group 1: n = 35) or isolated procedures from volunteers (group 2: n = 15) were without morbidity. A median yield of 4.0 X 10(9) mononuclear cells were recovered in a final volume of 104 ml of cell-rich plasma, for which 4,300 ml of venous blood was processed in 107 minutes. In neither group were changes documented in donor white cell count or lymphocyte numbers. In group 1, a statistically significant but clinically unimportant and transient fall occurred in the platelet count at the end of the 5-day intensive schedule. It is concluded that mononuclear fractions can efficiently be collected from normal donors without the development of relevant cell depletion.

Blood Donors↗
PubMed1987

Aluminium loading during therapeutic plasma exchange.

Graphite furnace atomic absorption spectroscopy was used to demonstrate a fivefold increase in the median plasma aluminium levels of four patients undergoing therapeutic plasmapheresis. This plasma aluminium loading resulted from contamination of albumin incorporated in the replacement fluids and took place during its preparation, with albumin aluminium levels of 646, 669, and 715 micrograms/liter present in three representative samples. Aluminium overload may result in the development of encephalopathy and osteomalacia in patients with renal impairment, indicating the need to monitor aluminium levels in the albumin-containing replacement fluids to avoid this potential hazard.

Aluminum↗
PubMed1987

Waldenstrom macroglobulinaemia treated with sequential hemibody irradiation.

A 40-year-old man presented with symptoms of anaemia and blurred vision. Waldenstrom macroglobulinaemia was diagnosed on the basis of plasmacytoid lymphocytes in the peripheral blood, extensive bone marrow involvement, and an IgM kappa monoclone in the plasma of 48 g/liter. Symptoms were immediately reversed by isovolaemic continuous-flow plasmapheresis coupled with red cell transfusion. Specific therapy was undertaken with sequential hemibody irradiation. At two years of follow-up the patient enjoys excellent health, has improved haematopoietic reserve in the bone marrow, and the only therapy required is intermittent plasmapheresis to control symptoms relating to rising viscosity. Thus, systemic irradiation, which is well tolerated and objectively reduces marrow tumour bulk, offers an alternative to chemotherapy in the palliative management of active macroglobulinaemia and may diminish but not prevent the need for intermittent plasmapheresis.

Adult↗
PubMed1987

Complete nucleotide sequence of the N-terminal domains of the murine alpha-1 type-III collagen chain.

We present the complete nucleotide (nt) sequence and derived amino acid (aa) sequence of the N-terminal portion of the murine alpha-1 type-III collagen chain. The detailed structure of this region is important for the understanding of type-III collagen biosynthesis in normal tissue and during fibrosis. The cDNA clones, pCIII-1-C119, pCIII-1-C534 and pCIII-1-C572, covering a total of 1485 nt, code for 19 nt of the 5' untranslated region, the 24 aa of the signal peptide, the 130 aa of the N-terminal propeptide, the 9 aa of the telopeptide and 334 aa of the helical domain.

Amino Acid Sequence↗
PubMed1986

Emergency surgery and refractory immune thrombocytopenic purpura. A case report.

A 35-year-old woman with post-splenectomy refractory immune thrombocytopenia presented with an acute abdominal emergency requiring laparotomy. Her platelet count was raised from 10 to 96 X 10(9)/l using a combination of high-dose methylprednisolone, plasma exchange against fresh-frozen plasma, infusion of gammaglobulin and a single mega-unit of platelets. The surgical procedure was uneventful, and with no further therapy the platelet count rose to a peak of 244 X 10(9)/l, but over the following 7 days fell back slowly to 10 X 10(9)/l, at which time the patient was discharged well.

Abdomen, Acute↗
PubMed1986

The effect of serial therapeutic plasmapheresis on platelet count, coagulation factors, plasma immunoglobulin, and complement levels.

One hundred therapeutic plasmaphereses were carried out at biweekly intervals in seven patients, without morbidity or mortality, using the IBM 2997 blood fraction separator. In standardised procedures, 1.5 times the calculated plasma volume was replaced with an electrolyte solution containing 4% salt-free human albumin. Anticoagulation was achieved using a whole venous blood to acid-citrate dextrose ratio of 11 to 1. Median flow rates, plasma collection, and procedure times were respectively 40 ml/minute, 20 ml/minute, and 3 hours. Haemoglobin and total white cell counts were not significantly affected by the procedures. In contrast, platelet count, fibrinogen, immunoglobulin levels, total haemolytic complement, as well as C3 and C4 fractions fell, and the prothrombin and partial thromboplastin times were lengthened by the exchanges. All these measurements had returned to normal within 24 hours, apart from the fibrinogen, which took between 48 and 72 hours, and the immunoglobulin level, which required 35 days to return to baseline. In a further patient, more detailed studies (n = 13) were carried out to characterise the behaviour of antithrombin III and factor VIII. Both levels were markedly reduced immediately following the procedure and, like fibrinogen, had returned to normal within 48 hours. These data indicate that in an isovolemic plasmapheresis there was a transient but rapidly reversible effect on all the factors studied, with fibrinogen level, antithrombin III, and factor VIII returning more slowly to normal than the others, and immunoglobulin levels responding the slowest. None of these changes was associated with clinically significant haemostatic abnormalities.(ABSTRACT TRUNCATED AT 250 WORDS)

Albumins↗
PubMed1986

Evidence for an immunocompromising effect of bovine pestivirus on bovid herpesvirus 1 vaccination.

Five calves were given live intranasal vaccine against bovid herpesvirus 1 (BHV1) two days after intranasal inoculation of bovine pestivirus (BVDV). Another 5 were vaccinated in the absence of BVDV. Control unvaccinated groups were also maintained. All calves were challenged with virulent BHV1. The unvaccinated calves developed signs of infectious bovine rhinotracheitis (IBR) and both vaccinated groups showed a similar degree of clinical protection from IBR. Those given BVDV before vaccination shed up to 140 times more BHV1 (P less than 0.01) in the nasal mucus following challenge than those which had received BHV1 vaccine alone. The epidemiological significance of this is discussed.

Animals↗
PubMed1986

Results of treatment in immune thrombocytopenia.

One hundred and forty-eight adults with immune thrombocytopenia attending a single institution between 1971 and 1981 were analysed retrospectively and observed for a minimum of three years. Prednisone was administered to 134 patients (90 per cent) in whom a peak platelet count occurred at a median of eight days, at which time four distinct patterns of response became evident: 20 patients (15 per cent) achieved complete remission with platelet counts greater than 200 X 10(9)/I, and of these 13 relapsed; 46 (34 per cent) had incomplete remission with platelet counts between 100 and 200 X 10(9)/I, and of these 38 relapsed; 22 (17 per cent) had a partial remission with platelet counts between 50 and 100 X 10(9)/I, and 14 have relapsed; the remaining 46 (34 per cent) failed to respond to prednisone. The addition of cytotoxic drugs for patients who relapsed or failed to respond to this agent was uniformly ineffective with the spleen in situ. One hundred and two patients underwent splenectomy without mortality, and peak platelet counts were achieved at a median of two days after the operation. Forty-one patients (40 per cent) achieved complete remission and four have relapsed; 36 (35 per cent) achieved incomplete remission and five have relapsed; 18 (18 per cent) had a partial remission and two have relapsed; treatment failed in seven (7 per cent). Eleven of the post-splenectomy patients relapsed in a median of four months. Together with the seven who failed to respond (n = 18), a subgroup of 17 was treated with immunosuppressive regimens including prednisone, azathioprine, cyclophosphamide or vincristine. Ten achieved stable although incomplete remissions, with platelet counts between 50 and 200 X 10(9)/I. We suggest that the treatment of immune thrombocytopenia in the adult initially should be a course of prednisone, from which complete remission rate will be 4.7 per cent and further incomplete remissions of 5.5 per cent and partial remissions of 8.5 per cent can be anticipated; no correlation was demonstrable with the duration of symptoms and response to prednisone. Symptomatic patients and those requiring unacceptable doses of adrenocorticosteroids should then proceed to splenectomy, when an overall response rate of 93 per cent is possible. A relapse rate of 11 per cent may require a limited course of immunosuppressive treatment, which is likely to be effective in approximately 75 per cent of these individuals.

Adolescent↗
PubMed1985

Cyclophosphamide-related intravascular haemolysis during continuous-flow plasma exchange.

The plasma of a patient being prepared for allogeneic bone marrow transplantation was found to be severely lymphocytotoxic to donor cells. Three isovolaemic plasma exchanges carried out using a continuous-flow technique were required to reduce this titre to undetectable levels. Neither these procedures nor pretransplantation conditioning of the patient with 60 mg/kg or cyclophosphamide on two consecutive days resulted in overt haemolysis. However, a single identical plasmapheresis 12 hours after completing the second dose of the alkylating agent resulted in profound intravascular haemolysis requiring red cell transfusion. Subsequent studies in five patients receiving the same cyclophosphamide regimen demonstrated that red cell life span, when measured with radiochromium, was reduced from a normal of 25-35 days to a median of 11.5 days. Further studies in the same five patients carried out simultaneously demonstrated that red cell fragility, when assessed in vitro with osmotic or mechanical stress, was marginally increased but became clearly abnormal in only one individual. These doses of cyclophosphamide may result in accelerated but subclinical red cell destruction, and plasma exchange in this period may be associated with rapid intravascular haemolysis. This complication should now be added to the list of those that can occur when plasmapheresis is required in this specific clinical situation.

Adult↗
PubMed1985

Platelet collection using the IBM 2997 cell separator.

Platelets were collected using the dual-channel module on the IBM 2997 Blood Fraction Separator. We carried out 320 procedures to harvest platelets for therapeutic purposes and yielded 5.1 +/- 1.5 X 10(11) platelets (mean +/- SD). Infusion into previously unsensitized recipients with hypomegakaryocytic thrombocytopenia achieved increments at 1 hr of 19 +/- 7.3 X 10(9)/liter/m2 (mean +/- SD) and at 24 hr of 15 +/- 6.3 X 10(9)/liter/m2. The only consistent donor reaction was mild hypocalcaemia, easily corrected by calcium gluconate infusion. Changes in donor packed-cell volume and white cell count were not statistically altered (p greater than 0.05) but donor platelet counts fell from 216 +/- 43.1 X 10(9)/liter to 162.5 +2- 41.7 X 10(9)/liter (mean +/- SD) (p less than 0.01). Additional plateletphereses were carried out in seven normal volunteers, using the same technique, in order that the function of the harvested platelets could be studied. Following radiochromium labelling and reinfusion into the same donors, normal in vivo recoveries were obtained at 10 min (59.4 +/- 3.4%; mean +/- SD) and platelet mean life span was also normal (218 +/- 12 hr; mean +/- SD). Furthermore, in vitro platelet factor III availability and aggregation patterns of the harvested platelets did not differ from control values and their ultrastructural appearance was normal.

Blood Platelets↗