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Biomedical subjects

U Bucher

Publications and source records attributed to U Bucher.

At least 37 records · Page 2Linked to original sources
PubMed1983

[Hemostasis disorders with reduced activity of the von Willebrand factor in myeloproliferative syndromes].

Splenectomy performed in a patient with polycythaemia vera and incipient osteomyelofibrosis was complicated by severe postoperative bleeding. A transient decrease of factor VIII/von Willebrand factor (VIIIR:WF) was detected as a possible cause of the bleeding tendency. As a result of this observation the VIIIR:WF system was investigated in all patients with myeloproliferative disorders who are presently followed by this laboratory. Subnormal VIIIR:WF activity was found in 5 of 9 prospectively investigated patients with polycythaemia vera and in one of 12 patients with chronic myeloid leukemia. These results suggest that acquired defects of the VIIIR:WF system are, in addition to the well known functional abnormalities of blood platelets, quite common in myeloproliferative disorders, especially polycythaemia vera, and must be reckoned with before surgery in particular. When specific antibodies directed against VIIIR:WF have been ruled out, the etiology of the VIIIR:WF defect found in our patients remains unclear.

Blood Coagulation Factors↗
PubMed1983

Rapid preparation of fresh platelet concentrates from CPD-blood by (mild) acidification.

Two methods of preparation of platelet concentrates (PC) derived from citrate-phosphate-dextrose (CPD) whole blood have been compared: (1) resuspension after having left the PC undisturbed at room temperature for 1 h (according to Mourad), and (2) immediate resuspension of the PC after the centrifugation of a platelet-rich plasma which has been acidified beforehand by the addition of ACD. In vitro platelet yield in acidified (CPD/ACD-)PC was at least equal to and, in cases with a particularly strong postcentrifugal tendency for clumping of platelets, clearly better (p less than 0.05) than in the 'Mourad platelets'. The results show that it is possible to produce PC from fresh CPD whole blood without delay. This may be helpful in clinical situations where freshly prepared PC should be available immediately. A special double bag (Fenwal DFX 733) containing CPD-A in the primary bag and 10 ml of ACD in the satellite bag, allows preparation of PC under these conditions in a closed system.

Blood Platelets↗
PubMed1983

Spontaneous hematologic recovery from bone marrow aplasia after accidental tenfold overdosage with radiophosphorus.

Two patients with polycythemia vera received intravenously an accidental tenfold overdosage of radiophosphorus therapy (60 and 50 mCi 32P, respectively). In both patients, the occurrence of hemorrhagic complications 3 wk after the 32P medication led to detection of the error and referral to our hospital. Upon admission they showed an agranulocytosis, severe thrombocytopenia, and bone marrow aplasia. In both cases, spontaneous recovery of the hematopoiesis was observed from day 40 posttreatment onward. In one patient, a slow but ultimately complete normalization of blood counts and marrow morphology took place, whereas in the other, a mild thrombocytopenia persists. Nearly 5 yr after the accidental overdosage, both patients are clinically well. Symptoms of polycythemia vera have not reappeared up to now. Attempts were made to evaluate the radiation dose absorbed by the bone marrow. In the first patient, the daily 32P excretion was determined from day 22 to day 60, whereas in the other patient a whole body count was performed on day 78 after administration. From these results, an approximate cumulative bone marrow dose of 10 Sv (1000 rem) could be calculated.

Aged↗
PubMed1982

[The 5q syndrome--a chromosome aberration with characteristic hematologic picture: preleukemia? Literature review and description of a personal case].

The case of a 74-year-old woman with macrocytic, refractory anemia, typical changes in the bone marrow and a 5q-chromosome in bone marrow cells is presented and the literature of this newly described hematological disorder is reviewed. The syndrome is characterized by partial deletion of the long arms of a chromosome No. 5 in bone marrow cells. The chromosomal anomaly is acquired and originates most probably from a pluripotent hematologic stem cell. Hematologic changes are (1) macrocytic, refractory anemia, (2) low to normal leukocyte counts, (3) normal to increased platelet number with marked anisocytosis and a high proportion of megathrombocytes, (4) normal to hypoplastic erythropoiesis and generally small megakaryocytes with nonlobulated nuclei in the bone marrow. In most of the reported cases (16 out of 19) with isolated 5q-anomaly, the clinical picture and laboratory findings remained stationary during a follow-up period of up to 6 years. In only 2 out of 19 cases did acute leukemia develop. In the presence of additional chromosomal abnormalities, all the cases developed acute leukemia and especially acute myelogenous leukemia. The diagnosis of 5q-syndrome in patients with refractory anemia is of prognostic significance, since it renders possible early recognition of a potentially malignant disorder and early detection of leukemic transformation.

Aged↗
PubMed1982

[Controlled substitution with blood products in hemostatic disorders].

It is essential for an efficient substitution to define the nature of the defect as good as possible. Simple screening tests allow a rapid classification. Prophylactic substitution is recommended in potentially reversible defects (bone marrow aplasia in connection with leukaemia treatment) and/or imminent bleeding (eventually complicated by additional risk factors). If bleeding cannot be stopped surgically therapeutic substitution is indicated. In case of bone marrow failure, a substitution may be particularly promising. In presence of an increased peripheral platelet destruction (disseminated intravascular coagulation, antithrombocytic antibodies) treatment of the basic disease is mandatory. Combined hemostatic defects can be influenced by fresh frozen plasma (FFP). Fresh whole blood (not older than 48 hours) may be considered in cases of thrombocytopenia and concomitant anemia. For isolated defects (e.g. hemophilias with or without antibodies, congenital afibrinogenemia, lack of factor XIII) special preparations are at hand. The clinical effect of substitution depends on the specific activity of the preparation, on the volume of expansion in the recipient and on other pharmacokinetic factors. Hepatitis and antibody-production may be considered as particularly grave side-effects.

Blood Coagulation Factors↗
PubMed1981

[Clarification of neutropenia].

Detection of neutropenia depends on the white cell count and the differential count, both of which involve considerable error. Pathogenetically, neutropenia can be attributed one of the following mechanisms: insufficient (or inefficient) formation, enhanced destruction or utilization, or--rarely--shift to the marginal pool. Isolated neutropenia should be distinguished from neutropenia combined with anemia and/or thrombocytopenia. The latter is usually due to bone marrow failure, whereas the former depends on peripheral mechanisms. Drug induced neutropenia may appear either as unforeseen acute agranulocytosis (aminophenazone type), depending on preceding sensitization, or as a slowly developing, dose-dependent cytopenia. Gradually developing neutropenia is an early stage of a general disease (collagen diseases, leukemia and other neoplasias, infections).

Agranulocytosis↗
PubMed1981

[Suspected leukemia: what should be done?].

Whenever leukaemia is suspected the diagnosis should be firmly established or excluded without delay. Clinical examination, blood counts (including platelet count) and a blood smear usually serve to diagnose or rule out chronic leukaemias. Bone marrow examination is necessary for the diagnosis of acute leukaemias. The value of additional tests, some of which are highly sophisticated, is not yet established. Chemotherapy of chronic leukaemias remains symptomatic. Various combinations of cytostatic drugs are used for treatment of acute leukaemias. Complete remissions are mostly achieved after transient bone marrow aplasia; this aplastic phase must be overcome by supportive measures. Although long survival is still exceptional in the adult, cure of the leukaemias appears to be theoretically possible. This view is supported by the preliminary results of bone marrow transplantation.

Adult↗
PubMed1981

Effects of nootropic drugs on dopaminergic systems in the CNS.

The effect of 3 nootropic drugs, meclofenoxat (MEC), piracetam (PIR) and orotic acid (methylglucamine orotate, MGO), on locomotor activity and on rotational behavior after intracerebral injection of dopamine was tested in female Wistar rats. Whereas MGO-pretreatment increased the dopaminergic supersensitivity following repeated haloperidol in both behavioral tests, the other nootropics were without influence on intensity and duration of supersensitivity. Stimulating and sedative action of apomorphine on locomotion (following 2 mg/kg and 40 micrograms/kg apomorphine sc, respectively) was found to be unchanged after single doses of nootropics (300 mg/kg PIR or MEC, 225 mg/kg MGO, 30 min before apomorphine). Preceding systemic application of nootropics did not change the rotational behavior following application of dopamine (200 micrograms/2 microliters) into nucleus accumbens or nucleus caudatoputamen. The results show that nootropic drugs are without influence on spontaneous and dopaminergically stimulated locomotor activity but in contrast to PIR and MEC, MGO is able to facilitate the dopaminergic supersensitivity.

Animals↗
PubMed1981

[Effect of ethanol on the behavior of mice treated with haloperidol].

Ethanol interacts with several central transmission systems. Following ethanol application we observed an inhibition of locomotion, vigilance and muscle tone in a modified Irwin-behaviour test. The effect was strengthened by a single dose of haloperidol. Contrary to this observation the ethanol effects decreased when haloperidol was given repeatedly for weeks before the application of ethanol. Three days after haloperidol withdrawal in case of nearly complete haloperidol elimination and development of dopaminergic supersensitivity the decrease was most pronounced. The results indicate that ethanol effects on dopaminergic functions are weakened in consequence of an increased efficiency of the adequate transmission system and vice versa.

Animals↗
PubMed1980

Cryoprotection of human bone marrow committed stem cells (CFU-c) by dextran, glycerol and dimethyl sulfoxide.

Dextran, glycerol and dimethyl sulfoxide (DMSO), alone or in combination, were used for cryoprotection of human bone marrow cells. The viability of cryopreserved cells was assessed by culture of myelopoiesis-committed stem cells (CFU-c) in vitro. A significantly better protection against freezing injury was obtained by 9% dextran in combination with 3 or 5% DMSO, and also with 5 or 10% DMSO alone, than with either 15% glycerol or 9% dextran with 1% DMSO.

Animals↗
PubMed1980

[Normal reference values in frequently carried out laboratory analyses hematologic cytology and blood coagulation)].

In 310 individuals (165 men and 145 women) significant pathological processes were exluded by reference to the patient's history, by physical investigation and by detailed laboratory tests (clinical chemistry, hematological cytology and most important coagulation analyses). Hematological laboratory values were then evaluated for age and sex differences, and in women according to menstruation versus post-menopause an oral contraception. Only the well known sex-specific differences in hematocrit values, hemoglobin and red cell counts were statistically highly significant (Z > 10). All other hematological values were pooled after exclusion of methodological errors. According to the non-symmetrical distribution of hematological laboratory values, percentiles were calculated. The 2.5 to 97.5 percentiles thus established now serve as "normal hematological reference values" for our laboratory.

Adult↗
PubMed1980

[Lymphatic manifestation forms in the terminal phase of chronic myelocytic leukemia].

A blastic transformation in chronic myeloic leukaemia (CML) is reported, which, on the one hand, is characterized by the "lymphoid" feature of blasts and, on the other hand, by the appearance of great lymph node swellings. The clear distinction from (secondary) malignant lymphomas may be difficult. The inclusion of such forms of blastic transformation in CML is based on cytogenetic findings. Their non-granulocytic or "lymphoid" nature emerges from their cytological behavior. The fact that these lymphoid transformations respond to vincristin and prednison emphasize that their recognition as special entities is justified. They also demonstrate that the neoplastic process in CML may not only involve myelopoietic but pluripotent stem cells as well.

Adult↗
PubMed1980

Immunothrombocytopenia and IgA nephritis.

A 32 year old female patient demonstrates the rare combination of a typical IgA nephritis and familial immunothrombocytopenia. Although this association may be purely fortuitous, our observation adds a new facet to a spectrum of reports on (familial) "thromborenal syndromes". The pathogenesis of the IgA nephritis has not yet been clarified. However, since IgA deposits are found relatively frequently in the mesangium in a number of diverse underlying diseases, there might be common etiological factors. In view of this possibility more attention should be directed to the investigation of IgA associated diseases.

Adult↗
PubMed1979

[Autologous bone marrow reimplantation in children with advanced tumor. First experiences of feasibility].

In three children with metastatic tumor uncontrollable by conventional chemo- and radiotherapy, bone marrow was obtained under general anesthesia and cryopreserved according to a carefully developed protocol. The autologous bone marrow cells were reinfused after intensive cytostatic therapy and total body irradiation (2 patients). After an aplastic phase of 7--14 days the peripheral blood leukocyte and thrombocyte count began to recover. The toxicity of the intensive treatment preceding the autologous bone marrow transfusion, and the autologous bone marrow cells themselves were well tolerated. The aplastic phase was easily controlled by the use of granulocytes, thrombocytes and erythrocytes. Except for fever and mucosal ulcerations observed during the phase of extreme leukopenia, the general condition of the patients during partial isolation lasting 26--34 days was astonishingly good. One child died 13 weeks after returning home due to a local relapse. The other two patients survived for 6 + and 11 + weeks and are in complete and partial remission respectively. A further evaluation of the clinical significance of autologous bone marrow reimplantations appears to be feasible in pediatric oncology.

Adolescent↗