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Biomedical subjects

R Ihle

Publications and source records attributed to R Ihle.

At least 19 recordsLinked to original sources
PubMed1996

Occupant generated carbon dioxide as a measure of dilution ventilation efficiency.

The time rate of decay of occupant generated carbon dioxide after workers have left a work area can be used in indoor air quality screening. Tests in a dilution chamber proved the goodness-of-fit of a limited exponential decay model. Correlation coefficients for the log-linear plots of the chamber tests approached unity as did the ratios of actual airflow to calculated flow. The model was used to estimate the number of air changes per unit time at the point of sample collection. Multiplying the number of air changes per minute by the room volume gave the effective ventilation rate. Dividing the actual quantity of air entering the space by the effective quantity provided a measure of ventilation effectiveness, i.e., a measure of mixing. The number of room air changes measured by carbon dioxide decay was positively correlated with the evaluator's qualitative assessment of the ventilation effectiveness in several offices and laboratories.

Air↗
PubMed1992

A short multilingual quality of life questionnaire--practicability, reliability and interlingual homogeneity.

International cooperative clinical trials require a multilingual quality of life questionnaire. The 'International Society for Chemo- and Immunotherapy' therefore designed a study to develop and test a 'health accentuated' quality of life questionnaire in the eight languages spoken in this society. The objective was to examine practicability, reliability and interlingual homogeneity. Versions of the questionnaire in Czech, German, Hungarian, Italian, Kroatian, Polish, Romanian and Slovakian have been prepared. The results are based on data of 1,104 adult patients. They demonstrate that the developed questionnaire is practicable. Patients need 10-15 min to answer it, usually without assistance. The proportion of missing values is for all but two questions less than 3%. The questionnaire also found high acceptance reflected by only 2.7% refusals. It is reasonably reliable in each language. Interlingual homogeneity could be shown by demonstration of strong structural similarities between the different versions using multidimensional scaling, factor analysis and comparison of mean profiles.

Adolescent↗
PubMed1989

Phenotype switch in acute leukemia patients after intensive chemotherapy.

According to Stass et al. the percentage of a lineage switch occurs in 6.7%-8.6% of patients with acute leukemia. Mostly, a conversion from the lymphoid to the myeloid phenotype is seen. In our three cases we found two switches from the myeloid to the lymphoid phenotype and only one from lymphoid to myeloid. This lineage switch is seen in relapsing and resistant leukemia cases. Different hypotheses have been discussed concerning the phenotype switch. Cytostatic chemotherapy may eradicate one leukemic cell clone, allowing another one to proliferate. Otherwise, the leukemic transformed stem cell could be influenced by the chemotherapy, resulting in a change of the differentiation program of the cell and following with a switch of marker expression. Perhaps there is some clinical importance to monitoring the phenotype switch in order to administer the best treatment.

Adolescent↗
PubMed1989

Sensitivity of CFU-GM from normal human bone marrow and leukaemic clonogenic cells (CFU-L) from blood of patients with myelogenous leukaemia to 3'-deoxy-3'-fluorothymidine in comparison to 3'-azido-3'-deoxythymidine.

3'-Deoxy-3'-fluorothymidine (FT), a thymidine analogue highly effective against HIV 1 in vitro was investigated as to its in vitro effect on normal human bone marrow CFU-GM (agar colony assay) and on human peripheral myeloid leukaemic clonogenic cells (CFU-L, colony assay in methylcellulose). For comparison, 3'-azido-3'-deoxythymidine (AZT), structurally related and used in AIDS treatment, was included in the study. Both compounds inhibit the formation of clusters and colonies from bone marrow stem cells with an [IC]50 between 10(-6) and 10(-5)M. In concentrations only 5-10 times lower than the [IC]50, FT begins to stimulate cluster and colony formation. AZT and FT also inhibit the formation of clusters and colonies from CFU-L. Compared to CFU-GM, CFU-L were more sensitive to FT, and a stimulation was not seen. It is concluded that similar side effects on bone marrow could be expected for possible use of FT against AIDS as have been found for AZT and that both compounds are potential candidates for anti-leukaemic drugs.

Adolescent↗
PubMed1989

Bone marrow stromal culture from patients with myelodysplastic syndromes and patients at different stages of acute nonlymphocytic leukaemia.

The haematopoietic microenvironment or stroma plays a decisive role for the proliferation and differentiation of haemopoietic cells. We studied if bone marrow cells from patients with myelodysplastic syndromes (MDS) and acute nonlymphocytic leukaemias (ANLL) are altered in their ability to form adherent stromal layer with active haemopoiesis in the Dexter liquid culture. Bone marrow cells were obtained from 24 normal volunteers, 28 patients with ANLL in different stages of the disease and 9 patients with MDS. There are no differences between the stromal layers of patients with ANLL in complete remission and those of normal volunteers after two weeks of cultivation. However, bone marrow cells from patients with ANLL before treatment and from patients in relapse formed a poor adherent stromal layer in most cases. In 6 of 9 cases we found the normal stromal grade of bone marrow cells from patients with MDS. There were qualitative differences in the nonadherent cell population between normal and ANLL patients in complete remission. In most cases we found morphologically recognizable erythroid cells after two-weeks Dexter liquid culture of bone marrow cells from patients with ANLL in complete remission, which were not seen with normal volunteers. This could be an indication of harmful effects on the balance of haematopoiesis caused by previous infiltration with leukaemic cells or/and high-dose chemotherapy.

Bone Marrow Cells↗
PubMed1988

[Evaluating the success of blood transfusion with erythrocytes preserved in different ways].

In a clinical study 18 patients with an indication to polytransfusion were examined by reason of secondary anaemias in diseases of the haemopoietic system. The efficiency of transfusion on the basis of body height, body mass and sex of the patients and the blood volume resulting from it as well as the exact amount of haemoglobin provided by stored blood and the increase of HB post transfusionem connected with it were found to be the criteria for the success of a transfusion. However, selected clinical parameters (LDH, Hbe, potassium, bilirubin) were constantly checked. The following values for the average efficiency of transfusion were found 16 hours post transfusionem: in washed erythrocyte concentrate 77%; in erythrocyte concentrate c. b. c. 45%; in erythrocyte concentrate GK 36%. Therefore, special emphasis is placed on an accompanying control of haemotherapy.

Blood Preservation↗
PubMed1988

[Effect of cytosine arabinoside on the differentiation of granulocyte-monocyte progenitors (CFU-GM) and myeloid leukemia blasts (CFU-L) in vitro].

The serum concentrations of Ara-C are in the range from 10(-6) to 10(-8) M in LD-Ara-C treated patients. The growth of CFU-GM from bone marrow of healthy volunteers was depressed depending on Ara-C-concentration applied in vitro. The growth of CFU-L from peripheral blood of two patients with AML (M 2) and one patient with CML in blast crisis was differently influenced by Ara-C-application in vitro. An elevated proportion of mature cells was observed in smears of cultured cells with Ara-C from two patients. The usefulness of Ara-C for a differentiation inducing therapy is discussed.

Cell Differentiation↗
PubMed1987

[Bone marrow aplasia: a rare complication in virus-induced hepatitis].

Bone marrow aplasia associated with acute viral hepatitis is a rare, in the rule late complication. A prognostic relation between the latency of acute hepatitis and the development of aplastic anemia is described. We report a case of nearly symptomless hepatitis in a 25 year old women with a fatal course of aplastic anemia. First clinical symptoms were caused by aplastic anemia. The pathogenesis of aplastic anemia associated to viral hepatitis is obscure. Genetic and immunological causes are discussed. A direct viral action is possible. Because the main part of the described cases is caused by non-A, non-B hepatitis, it seems apparent that at least a non-A, non-B virus strain could have an affinity to bone marrow cells. Ensuring this, relations will be impossible up to the identification of the virus.

Adult↗
PubMed1987

[Determination of the S-phase fraction of myeloid-determined stem cells (CFU-GM) using the cytosine arabinoside suicide technic in patients with acute myeloid leukemia in complete remission following polychemotherapy].

S-phase fraction of granulocyte-macrophage colony forming cells (CFU-GM) was assessed by cytosine arabinoside suicide technique in five normal volunteers and eight patients with acute myeloblastic leukaemia in complete remission after the cessation of polychemotherapy. An increased proliferation of CFU-GM (S-phase-fraction: 55-80%) was found in bone marrow of patient in complete remission up to the 27th day after polychemotherapy. Reduction of this increased proliferation was seen at day 30 after the cessation of polychemotherapy (S-phase fraction: 22 and 33%). Because of increased proliferation of CFU-GM in the early phase after polychemotherapy cytostatic drugs of the antimetabolite-type seem to be unsuitable for purging bone marrow in remission.

Adolescent↗
PubMed1987

[Effect of hormonal contraceptives on blood pressure following pregnancy-induced hypertension].

During a period of observation of one year blood pressure was measured three times in the 0,6 th and 12 th months from a group of users of oral contraceptives (n = 377) and a reference group (n = 238) dependent from pregnancy-induced hypertension in women's history. Mean systolic blood pressure dropped in the group of oral contraceptive users by 0.7 mm Hg (0.1 kPa), diastolic blood pressure increased by 2.1 mm Hg (0.3 kPa) with significant difference vs. the reference group. Mean systolic blood pressure increased by 1.7 mm Hg (0.22 kPa) 6 months after using oral contraceptives in the group with pregnancy-induced hypertension (with significant difference). In the reference group without pregnancy-induced hypertension mean systolic blood pressure increased by 1.5 mm Hg (0.2 kPa) (without significant difference). Diastolic blood pressure values were not different. In the subgroup with pregnancy-induced hypertension history basal values of systolic and diastolic blood pressure distinctly were higher than in the control group.

Adult↗