Search PubMed⌕ Search

Biomedical subjects

F Wiener

Publications and source records attributed to F Wiener.

At least 91 records · Page 5Linked to original sources
PubMed1980

Restriction of C-type viral antigen in H-2/Fv-1 syngeneic mouse somatic cell hybrids.

Somatic cell hybrids between an AKR lymphoma or a C3H sarcoma and H-2, Fv-1 syngeneic CBA sarcoma or carcinoma have been examined for expression of the structural components of murine leukemia virus (MuLV) by radioimmunoassay and complement-dependent cytotoxicity assay. Parental AKR and C3H cells contained high concentrations of MuLV core protein p30 in their cell extracts and showed high sensitivity to anti-MuLVgp70 and p30 sera. In contrast, CBA cells expressed little detectable p30 in the extracts, were much less sensitive to anti-gp70 serum, and were almost insensitive to anti-p30 serum. The hybrids between the AKR or C3H cells and CBA cells had a decreased amount of p30 in the extracts and were almost resistant to cytotoxicity by anti-p30 serum, although they maintained high sensitivity to anti-gp70 serum. These findings suggest that the CBA genotype suppresses the production and cell-surface expression of p30 antigen of AKR and C3H endogenous C-type viruses. The suppressive gene is not Fv-1n.

Animals↗
PubMed1980

Nonrandom chromosomal changes in thy-1-positive and thy-1-negative lymphomas induced by 7,12-dimethylbenzanthracene in SJL mice.

Leukemias were induced by 7,12-dimethylbenzanthracene feeding of intact, thymectomized, or Freund's adjuvant-pretreated SJL mice. Four of six Thy-1-positive thymomas that arose in intact mice had a pseudodiploid stemline with one morphologically similar or identical marker. Banding analysis showed that the marker had arisen by the translocation of the distal part of one chromosome 15 to one X chromosome [t(X;ter 15)]. Two normal No. 15 chromosomes were also present in the same metaphase plates. These four Thy-1-positive lymphomas were thus trisomic for the distal part of chromosome 15. All 8 Thy-1-negative lymphomas, originating in the spleen or lymph nodes of thymectomized or adjuvant-pretreatment mice, had a trisomy of chromosome 12 and also a trisomy of either chromosome 3 or chromosome 18. These results further stress the importance of gene dosage effects, related to the distal part of chromosome 15, in Thy-1-positive T-cell leukemogenesis. The cytogenetic difference between the Thy-1-positive and -negative leukemias supports our hypothesis that nonrandom chromosomal changes in murine leukemias are dependent on the target cell type, rather than the inducing agent.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1979

Non-random duplication of chromosome 15 in murine T-cell leukemias induced in mice heterozygous for translocation T(14:15)6.

Trisomy of chromosome 15 is a highly regular feature of murine T-cell leukemogenesis. We have studied the chromosomal constitution of 7,12-dimethylbenza(a)anthracene (DMBA)-induced T-cell leukemias in C57BL X CBAT6T6 F1 mice. The CBAT6T6-derived chromosome T(14:15)6 was regularly duplicated whereas the C57BL-derived normal chromosome 15 was only present in one copy. It was concluded that the gene(s) that tend to duplicate in parallel with the neoplastic transformation of the prothymocyte to an overt leukemic cell have a greater chance of duplicating and/or may have a stronger promoting effect on leukemogenesis if stronger promoting effect on leukemogenesis if located on the CBA-derived, structurally rearranged T(14:15)6 than the corresponding genes located on the C57BL-derived normal chromosome 15.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1979

Nonrandom chromosome changes involving the Ig gene-carrying chromosomes 12 and 6 in pristane-induced mouse plasmacytomas.

The karyotypes of pristane-induced mouse plasmacytomas were studied by G banding. Only primary tumors or early passage generations were analyzed. In contrast to murine T cell leukemias that showed a regular trisomy of chromosome 15, all plasmacytomas showed a consistent translocation of the distal part of chromosome 15 to either chromosome 6 [rcpT(6;15)] or 12 [T(12;15)]. The specific breakpoints were at 6C, 15D3/E ro D2/3 and 12F2. Early passage generations often showed a mixed population with two different translocations, suggesting polyclonal origin. Considered together with the known karyotypic features of murine and human lymphomas, these findings support the theory that the nonrandom chromosomal changes in lymphoproliferative malignancies are associated with the type of the target cell, rather than with the etiological agent. Moreover, the involvement of the chromosomes known to carry the heavy chain (12) and the light chain (6) determinants, respectively, raises the question of whether the translocations may be related to the DNA level rearrangements known to occur during the differentiation of normal plasma cells.

Animals↗
PubMed1979

Is trisomy cause or consequence of murine T cell leukemia development? Studies on Robertsonian translocation mice.

Trypsin-Giemsa banding studies on T cell leukemias induced in Robertsonian translocation mice by dimethylbenz[a]anthracene and Moloney leukemia virus show a trisomy of chromosome 15 even in cases in which chromosome 15 has undergone centromeric fusion with chromosomes 1, 5, or 6. These results suggest that the duplication of gene(s) located on chromosome 15 is of critical importance for murine T cell leukemia development.

Animals↗
PubMed1979

A study of the renal countercurrent system by computer simulation.

A model of the renal medulla is formulated, taking into account the transport properties of each medullary structure. Using known data on inflow to the vascular and tubular systems and on urine output in normal man in hydropenia, and assuming medullary osmotic profiles similar to published data on hydropenic dogs, transport coefficients are calculated for each medullary structure. The calculated coefficients compare reasonably well with measurements made in the rat kidney. A normal hydration case is calculated by reducing the collecting duct permeability until a urine output and concentration of 1.0ml/min and 700 mosm/l is obtained. The coefficients are then kept constant, and medullary osmotic profiles and urine output corresponding to various system imputs are calculated. These studies show that medullary osmolarities decrease and urine flow increases with increasing medullary blood flow and that an optimal rate of proximal reabsorption exists for producing a maximally concentrated urine. Such results are consistent with observations on renal function reported both experimentally and clinically.

Biological Transport↗
PubMed1979

Measurement of toe temperature for assessing the severity of acute circulatory failure.

The temperature gradient between the ventral surface of the first toe and the ambient temperature was measured and compared with established hemodynamic measurements in 71 critically ill patients. Thirty-two patients had acute myocardial infarctions, 21 patients had primary bacteremia and 18 patients had primary hypovolemia which followed acute blood loss. The temperature gradient served as a more predictable indicator of survival or fatality than either arterial pressure or cardiac index in each group of patients. Patients who improved after treatment and survived had increases in the toe minus ambient temperature gradient to more than 4 degrees C., whereas a gradient of less than 3 degrees over an interval of 12 hours was typically observed in patients who subsequently died. These observations indicate that the toe minus ambient temperature gradient provides a valuable, inexpensive and noninvasive monitor of tissue perfusion in critically ill patients.

Acute Disease↗
PubMed1978

Chromosome changes (trisomy 15) in murine T-cell leukemia induced by 1,12-dimethylbenz(a)anthracene (DMBA).

The banding pattern of DMBA-induced leukemias in C57BL/6 mice revealed a very constant chromosome pattern: the presence of trisomy 15 in almost all leukemic cells. This finding strongly suggests that chromosome 15 trisomy is the first detectable specific chromosome change associated with the development of DMBA-induced T-cell lymphomas. A similar association was previously shown with regard to development of radiation-leukemia-virus-induced T-cell lymphoma. It is conceivable that in tumors of diverse etiologies common cytogenetic changes may appear in the same common target-cell precursor, by a process of the "convergent microevolution" type.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1978

Proof of in vivo fusion of murine tumor cells with host cells by universal fusers.

Two mouse cell lines (A9HT CI.3C and 501-1), each carrying both a recessive and a dominant mutation (and therefore designated "universal fusers"), were utilized for selection of in vivo hybrids from tumors produced intraperitoneally and subcutaneously in appropriated hosts. The double selective medium eliminated both parental (tumor and host) cells but allowed the survival and proliferation of the fused product. This proved that hybridization between tumor and host cells occurred in vivo.

Animals↗
PubMed1978

Chromosome changes (trisomies #15 and 17) associated with tumor progression in leukemias induced by radiation leukemia virus.

An experimental system was developed that permitted nonrandom chromosome changes that occur in radiation leukemia virus (RadLV)-induced lymphomas to be followed during tumor progression. RadLV variant-induced preleukemia and leukemia cells originating from female inbred C57BL/6 mice were injected into male animals of the same strain. Since all donors were females and all recipients were males, the sex chromosome complements (XX and XY) were used to distinguish the preleukemia and leukemia cells from those of host origin. The G-banding analysis revealed that more than 50% of animals that were inoculated with preleukemia cells and that developed leukemia possessed tumor stem-lines of 41 chromosomes with a tristomy of chromosome #15. In animals inoculated with overt leukemia cells and in which tumor progression occurred, the G-banding an additional trisomy of chromosome #17. The cytogenic data strongly suggested that the trisomy of chromosome #15 was the first specific tumor-associated chromosome change that occurred in the process of conversion of RadLV-induced preleukemia cells to fully autonomous tumor cells.

Animals↗
PubMed1977

Chromosome banding, isoenzyme studies and determination of Epstein-Barr virus DNA content on human Burkitt lymphoma/mouse hybrids.

Four independently fused hybrid clones derived from a cross between the mouse mammary carcinoma TA3Ha and the human Burkitt lymphoma line Daudi were tested for the EBV-determined nuclear antigen (EBNA), EBV-DNA and the presence of human chromosomes, in the course of serial propagation in vitro. EBNA and EBV-DNA were lost in parallel with the loss of human chromosomes. It seems that the persistence of EB-viral genetic information does not require the presence of a specific human chromosome(s) in this particular hybrid combination.

Animals↗
PubMed1977

Computer simulation of medical reasoning in the assessment of kidney disease.

A system for the simulation of clinical reasoning was applied to the evaluation of patient data in nephrological diseases. The system allows the physician to computerise the medical logic in his area of specialisation, to prepare suitable protocols for recording clinical observations, to analyse the patient data for assessing his present clinical status and to plan appropriate diagnostic and therapeutic interventions. The medical logic is expressed in modular form as a series of inferences to be confirmed or rejected on the basis of Boolean combinations of clinical findings and previous inferences. The acceptable Boolean combinations are formulated in terms of threshold logic. The computer programs produce alphabetical lists of the clinical findings appearing in the medical logic, which are organised by the physician into data acquisition protocols appropriate to each phase of clinical activity. The system was run on a series of 22 patients hospitalised in the Department of Nephrology. The patient status reports produced by the computer were in substantial agreement with the assessment of a senior nephrologist. The protocols assured a more complete and accurate recording of patient data than that appearing in the routine patient chart. The program was of value in standardising patient examinations and in the training of new medical staff.

Diagnosis, Computer-Assisted↗
PubMed1977

Computer-aided tumour classification and treatment selection in breast cancer.

In order to provide a common basis for treatment decisions and the future evaluation of breast cancer therapy, the breast cancer protocol used in our clinic was formulated for the computer. A system for the simulation of clinical reasoning was used which allows the physician to express the medical logic as a series of inferences to be confirmed or rejected on the basis of Boolean combinations of medical criteria. The system enables the physician to rearrange these criteria into a questionnaire for complete and accurate recording of patient data. These data are then fed into the computer to produce a patient status report and treatment recommendations. The data from 26 patients in various stages of breast cancer have been processed by the computer and the computer's conclusions compared to the assessment made by a junior physician in our department. In three cases the staging was not identical, in 15 cases the treatment decisions were not identical and in all cases investigations were left out by the physician. The system has been of considerable value in standardising patient examination and treatment and in training inexperienced physicians.

Breast Neoplasms↗