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Biomedical subjects

R B Jenkins

Publications and source records attributed to R B Jenkins.

At least 145 records · Page 8Linked to original sources
PubMed1989

Acute leukemia with abnormal thrombopoiesis and inversions of chromosome 3.

Abnormal thrombopoiesis has been described in acute leukemias associated with inv(3) (q21q26.2) or t(3;3)(q21;q26.2). We reviewed 13 patients seen at the Mayo Clinic since 1979 with inversions of chromosome 3 or related abnormalities; 12 acquired and one constitutional. The patient with the constitutional abnormality had an inv(3)(p21q29) and mild leukocytosis and thrombocytosis. Among the 12 patients with acquired abnormalities, five had inv(3) (q21q26.2), three had t(3;3)(q21;q26.2), one had del(3)(q12q21), one had ins(6;3) (p21;q21q26.2), one had inv(3)(p21q12), and one had r(3)(p?21q?21). Each of these patients developed acute leukemia; eight had antecedent myelodysplastic syndrome, eight presented with platelet counts greater than 100 x 10(3)/microliters, and six had atypical megakaryocytic hyperplasia. Five patients had ringed sideroblasts in their marrow, an antecedent refractory anemia with ringed sideroblasts, or erythroleukemia. Seven patients received chemotherapy but showed no response. From the time of chromosome study, the median duration of survival was 4 months. Our results suggest that 1) although abnormal megakaryocytopoiesis is observed in patients with inv(3)(q21q26.2), multiple hematopoietic lineages are also involved in the neoplastic process; 2) an antecedent myelodysplastic syndrome is common in acute leukemia with inv(3) or related abnormalities; 3) affected patients have a poor survival and are resistant to conventional chemotherapy; and 4) abnormal megakaryocytopoiesis in acute leukemia may also be associated with pericentric inversions of chromosome 3.

Acute Disease↗
PubMed1989

A cytogenetic study of 53 human gliomas.

Cytogenetic studies were performed on human glioma samples obtained by stereotactic biopsy, stereotactic craniotomy, or routine craniotomy. Using in situ culture and robotic harvesting techniques, we obtained suitable metaphases in 50 (94%) of 53 tumors, including 28 diffuse astrocytomas, four juvenile pilocytic astrocytomas, two gliosarcomas, three other miscellaneous astrocytomas, eight oligodendrogliomas, four mixed oligodendroglioma-astrocytomas, and four ependymomas. Cytogenetic studies were performed only on primary cultures; the mean culture time was 9.6 days (range 1-31 days). One or more chromosomally abnormal clones were observed in 35 (66%) tumors. Eleven (21%) other specimens had random nonclonal chromosome abnormalities. In four (8%) specimens, no chromosome abnormalities were noted. The results of this study suggest that grade 3 and 4 tumors are more likely to contain an abnormal clone than tumors of grade 1 or 2 (p less than 0.01). The most common numeric chromosome abnormalities were -6, +7, -10, -13, -14, -15, -18, and -Y. The most common structural abnormalities involved 1p, 6q, 7q, 8p, 9p, 11p, 11q, 13q, and 19q. Four tumors had two or more independent clones and ten contained subclones demonstrating karyotype evolution. With in situ culture and robotic harvesting techniques, cytogenetic studies can be successful on nearly all human gliomas, including those derived from small stereotactic biopsies.

Adolescent↗
PubMed1989

Cytogenetic analyses on giant-cell tumors of bone.

Giant-cell bone tumors are considered to be benign proliferations composed of poorly differentiated mononuclear cells and large multinucleated giant cells with the appearance of osteoclasts. Treatment is usually surgical resection, but there is a small risk of local recurrence and metastasis. Cytogenetic analyses were performed on giant-cell bone tumors of six consecutive patients. Chromosomally abnormal clones were found in three of the tumors, but no two patients had the same chromosome abnormality. Thus, there was no correlation between any specific chromosome change and the clinical behavior or histology of giant-cell bone tumors. However, all of the tumors had a significantly higher incidence of nonclonal chromosome abnormalities than is encountered in cultures of normal cells. The most common nonclonal abnormalities involved unusual telomere-to-telomere chromosome translocations. These findings suggest that the cells in these tumors are chromosomally unstable. The telomeres most frequently involved were on the long arm of chromosomes 19 and 20.

Adult↗
PubMed1986

CFU-M-derived human megakaryocytes synthesize glycoproteins IIb and IIIa.

Human megakaryocytes have been shown by immunofluorescent techniques to express platelet glycoprotein IIb/IIIa antigen. We report evidence that megakaryocytes derived from human committed megakaryocytic progenitor cells in vitro (CFU-M) synthesize glycoproteins IIb and IIIa. Nonadherent light-density human bone marrow cells were cultured in human plasma and methylcellulose using conditions that promote large megakaryocytic colonies. On day 13 the megakaryocytic colonies were picked, pooled, and pulsed with 35S-methionine in methionine-free media. Populations of approximately 100,000 cells with greater than or equal to 95% viability and containing 70% to 90% megakaryocytes were obtained reliably for study. After the radioactive pulse, the cell suspension was solubilized with nonionic detergent. To reduce nonspecific binding of 35S-labeled proteins to agarose, the lysate was chromatographed sequentially on glycine-quenched Affi-gel and antihuman factor X-Sepharose. The unbound material from these resins was then chromatographed on an antiglycoprotein IIb/IIIa monoclonal antibody resin (HP1-1D-Sepharose) or on a control monoclonal antibody resin. Bound fractions were eluted and analyzed by polyacrylamide gel electrophoresis and autoradiography. Autoradiograms of diethylamine eluates from HP1-1D-Sepharose revealed two labeled proteins with electrophoretic mobilities identical with those of human platelet membrane glycoproteins IIb and IIIa, isolated using similar conditions. Autoradiograms of material synthesized by control macrophages from the same donors revealed no significant labeling of proteins in the glycoprotein IIb/IIIa molecular weight range, nor were such proteins bound by HP1-1D-Sepharose. Our observations show that protein synthesis by CFU-M-derived human megakaryocytes can be readily studied using a small amount of bone marrow aspirate as starting material. This approach will allow the study of protein synthesis by megakaryocytes from normal subjects or from subjects with clinical disorders, and it will circumvent the need to obtain large amounts of bone marrow to prepare enriched populations of megakaryocytes.

Chromatography, Affinity↗
PubMed1981

Chondroitin 6-sulfate oligosaccharides as immunological determinants of chick proteoglycans.

Monoclonal antibodies to hyaluronidase-treated chondroitin sulfate proteoglycan (CSPG) were used to study the immunological determinants of chick cartilage proteoglycan. The determinants recognized by the antibodies were studied by a radioimmune inhibition assay utilizing hyaluronidase-treated [35S]CSPG. Hyaluronidase-treated CSPG inhibits the reaction of four clonal antibodies, S54C, S103L, S11D, and P100D, with [35S]CSPG, but to varying degrees. Only the reaction of S103L is inhibited to a considerable extent by undigested CSPG, indicating that hyaluronidase treatment exposes determinants specific for the other three antibodies. These findings are consistent with the earlier conclusion that S103L is specific for a protein determinant (Dorfman et al., 1980). Only the reaction of S54C is not significantly inhibited by chondroitinase ABC-digested CSPG. This result indicates that chondroitinase ABC digestion can also expose determinants recognized by S11D and P100D but that such digestion removes the determinant recognized by S54C. Of the four antibodies tested, only the reaction of S54C with hyaluronidase-treated [35S]CSPG is significantly inhibited by chondroitin-6-SO4 tetra- and hexasaccharide (59 and 43% inhibition, respectively, at a concentration of 1333 microM). The reaction of S54C is inhibited to a lesser extent by chondroitin tetra- and hexasaccharide (28 and 26% inhibition, respectively, at a concentration of 1333 microM). In contrast, chondroitin-4-SO4 oligosaccharides do not inhibit the reactions of any of the clonal antibodies. These result suggest that S54C recognizes a determinant that contains chondroitin-6-SO4 oligosaccharide, attached via the linkage oligosaccharide to core protein.

Animals↗
PubMed1981

Multifocal primary ocular and central nervous system malignant lymphoma.

A patient had bilateral posterior uveitis of two weeks' duration and rapid neurologic deterioration. Obstructive hydrocephalus developed as a result of compression of the fourth ventricle by an enlarged cerebellar vermis. Autopsy revealed multiple foci of infiltration by malignant lymphomas in the eyes, brain, and cerebellum; no evidence of systemic lymphoma was found.

Brain Neoplasms↗
PubMed1975

Improvement of Parkinsonism in depressed patients treated with ECT.

Two patients with severe Parkinson's disease were treated with electroconvulsive therapy for a supervening depression. Not only did the symptoms of depression clear up after only four treatments, but the parkinsonian signs also showed striking and sustained improvement. This may be related to ECT-induced changes in dopamine and norepinephrine metabolism. Parkinsonism does not appear to be a contraindication to ECT. On the contrary, ECT may be the treatment of choice for certain patients with Parkinson's disease, whether nor not it is complicated by intractable depression.

Aged↗
PubMed1972

Levodopa therapy of patients with Parkinsonism and heart disease.

Forty patients with Parkinsonism and heart disease were studied before and during the administration of levodopa. Patients with increasing angina, myocardial infarction within the previous year, pre-existing severe postural hypotension, or transient cerebral ischaemia were excluded. Thirty-eight patients showed no adverse effects; angina improved in one patient but later worsened; one patient died of myocardial infarction after a severe gastrointestinal haemorrhage. Therapy with levodopa appears to pose little increased hazard to patients with most forms of heart disease. Inpatient monitoring is recommended at the beginning of therapy, and antiarrhythmic agents should be used when required.

Aged↗