Search PubMed⌕ Search

Biomedical subjects

F M Davis

Publications and source records attributed to F M Davis.

At least 73 records · Page 4Linked to original sources
PubMed1985

Phosphorylation of nonhistone proteins during premature chromosome condensation in a temperature-sensitive mutant, tsBN2.

In tsBN2 cells, a temperature-sensitive (ts) mutant of the BHK21 cell line, with a ts-defect in its regulatory system for chromosome condensation, antigens that react with mitotic specific mouse monoclonal antibody MPM-2 were produced when premature chromosome condensation (PCC) was induced by a temperature shift. The polypeptides of antigens recognized by MPM-2 in tsBN2 cells with PCC were identical to those of antigens in mitotic cells. These antigens appeared concomitantly with chromosome condensation, which suggests that these mitotic-specific antigens may be related to chromosome condensation. As the production of mitotic-specific antigens was inhibited by W-7, a specific and potent antagonist of calmodulin, calmodulin may function in the mitotic phosphorylation of nonhistone protein.

Animals↗
PubMed1985

Growth factor-mediated proliferation in B cell non-Hodgkin's lymphomas.

The non-Hodgkin's lymphomas (NHLs) are a heterogeneous group of human lymphoid tumors, primarily of B cell lineage, which appear to represent arrested stages in B lymphocyte differentiation. Control of cell proliferation is a fundamentally important but poorly understood area of study in these tumors. We have studied a representative group of B cell NHLs to assess their potential for growth factor-mediated proliferation in vitro. Our results show that purified monoclonal NHL B cells of the small cell (well-differentiated lymphocytic lymphoma, nodular poorly differentiated lymphocytic lymphoma, etc) type, that were positive for the human malignancy-associated nucleolar antigen could be stimulated by human B cell growth factor (BCGF) to proliferate in vitro. Other B cell activators such as insoluble anti-Ig and the mitogen protein A also could stimulate thymidine incorporation in the lymphoma cell populations. In vitro lymphoma cell growth could be maintained in the presence of the growth factor for up to five weeks. The large B cell type NHL, however, appeared to be refractory to in vitro stimulation by BCGF as well as other stimulators of normal B cells. These studies suggest that human B cell lymphoid tumors are not only phenotypically similar to their normal B lymphocyte counterparts, but are also sensitive in some cases, to the same types of immunoregulatory molecules that control normal lymphoid cell growth.

Antigens, Surface↗
PubMed1984

Phosphoproteins are components of mitotic microtubule organizing centers.

Protein phosphorylation has been suggested as an important control mechanism for the events leading toward the initiation and completion of mitosis. Using a monoclonal antibody recognizing a class of phosphoproteins abundant in mitotic cells, we demonstrated the localization of a subset of these phosphoproteins to several discrete mitotic structures. Patchy immunofluorescence was present in the interphase nuclei, but a significant increase in nuclear immunofluorescence was apparent at prophase. Subsequent mitotic stages demonstrated that immunoreactive material was particularly apparent at microtubule organizing centers, namely, centrosomes, kinetochores, and midbodies. Intense centrosomal localization occurred at the prophase-prometaphase transition and persisted until the reformation of the nuclear membrane in early G1. The cytoplasm of mitotic cells also contained immunoreactive material in sharp contrast to interphase cells that exhibited no cytoplasmic fluorescent staining. Much of the diffuse immunofluorescent cytoplasmic material was removed by a brief lysis of the cells with 0.15% Triton X-100 prior to fixation. The localization of the remaining immunoreactive material after detergent lysis to mitotic microtubule organizing centers suggests that they contain phosphoprotein structural components important, perhaps, in the mitotic phase-interphase transition.

Animals↗
PubMed1984

Identification of human lymphoma cells by antisera to malignancy-associated nucleolar antigens.

The non-Hodgkin's lymphomas (NHL) are a diverse group of human lymphoid neoplasms that have long presented pathologists with formidable diagnostic challenges. These tumors of the immune system are thought to represent neoplastic transformations of most of the recognized stages in T and B lymphocyte ontogeny. Lymphoma cells, however, often simulate their normal lymphocytic counterparts both morphologically and cell surface phenotypically, creating difficulties in discriminating normal from neoplastic lymphocytes. We have used heteroantisera to the human malignancy-associated nucleolar antigen (HMNA) to prospectively evaluate its efficacy in identifying the morphologically neoplastic cells in NHL lesions. In 65 cases of T and B cell histopathologic types of NHL, the antisera reacted with nucleoli in the morphologically and cytogenetically neoplastic lymphoma cells, but not with normal-appearing lymphoid and other cell types present in the lesions. Control specimens from normal and hyperplastic lymphoid tissue also failed to react with anti-HMNA antibodies. Normal activated lymphoid cells in vitro and growth-factor-dependent normal lymphoid cell lines also failed to express the nucleolar antigen(s). These data suggest that the HMNA is a valuable tumor cell marker for neoplastic human lymphoid cell populations and can be used with other types of cell markers for a better definition of the neoplastic cells in NHL.

Adult↗
PubMed1984

Human malignancy-associated nucleolar antigen as a marker for tumor cells in patients with acute leukemia.

Tumor burden in adult patients with acute leukemia is assessed using the percentage of blast cells in the bone marrow or blood. It is clear, however, that not all blast cells are leukemic cells, especially during rapid marrow regeneration. Similarly, some leukemia cell lines have been shown to differentiate in vitro, and the same process also occurs in vivo. Therefore, the leukemic burden may be due to more differentiated cells as well as to blast cells. The purpose of this study was to investigate whether the human malignancy-associated nucleolar antigen (HMNA) could be used as a marker for leukemic cells and to examine its potential as a diagnostic tool. The proportion of HMNA-positive cells in the bone marrow of patients with acute leukemia was determined by indirect immunofluorescence with antibodies to HMNA and was compared with the differential counts routinely made in the clinic laboratory. The percentages of HMNA-positive cells among the nucleated cells in the marrow of 72 patients with clinical evidence of leukemia were significantly higher (range 9%-98%, median 83%) than those observed for nonleukemic individuals (range less than 0.05%-2.5%, median 1%) or for fractions of marrow cells from normal volunteers enriched for normal early progenitor cells (less than or equal to 2%). Patients with leukemia in remission had a lower percentage of HMNA-positive cells (range 0%-83%, median 3%). The percentage of HMNA-positive cells increased as patients approached relapse. Although the percentage of HMNA-positive cells was related to the percentage of blast cells in the bone marrow of the patients with leukemia, some partially differentiated cells were also HMNA-positive in some specimens, and some blastic cells were HMNA-negative in other specimens. These studies indicate the potential usefulness of HMNA as a marker for leukemic cells.

Acute Disease↗
PubMed1983

Detection of leukemic cell colonies in agar plates by immunostaining for human malignancy-associated nucleolar antigen.

We have developed an indirect immunofluorescence technique to stain individual colonies in situ in agar to detect the presence of a human malignancy-associated nucleolar antigen. Bone marrow and peripheral blood cells from leukemia patients who were untreated or suffering relapse were used as a source for colony formation. The agar layer containing the colonies was stabilized by overlaying it with an additional agar layer. Cells in the colonies were fixed with methanol, rehydrated, and incubated for prolonged periods in both the primary and the secondary antibodies. The agar was then transferred onto a glass slide, air dried, and examined using a fluorescence microscope. The method is widely applicable for staining colonies in situ in agar with both polyclonal and monoclonal antibodies.

Animals↗
PubMed1983

Monoclonal antibodies to mitotic cells.

Certain proteins or activities are present in mitotic cells but not in interphase cells. These proteins may be synthesized or activated, or both, just prior to mitosis and are responsible for the breakdown of the nuclear envelope and the condensation of chromosomes. To learn more about the nature of these proteins, we raised monoclonal antibodies to mitotic cells. Spleen cells from mice immunized with a 0.15 M NaCl extract of synchronized mitotic HeLa cells were fused with SP2/0-Ag14 mouse myeloma cells, and hybrids were selected in medium containing hypoxanthine, methotrexate, thymidine, and glycine. Two different hybridoma clones secreting antibodies reactive with mitotic and meiotic cells from every species tested were isolated. Chromosomes as well as cytoplasm in mitotic cells reacted with the antibodies, as detected by indirect immunofluorescence. The proteins from mitotic cells were separated by electrophoresis in NaDodSO4/polyacrylamide slab gels, transferred to nitrocellulose sheets, and stained immunochemically. The two antibodies, designated MPM-1 and MPM-2, recognize a family of polypeptides with apparent molecular masses of 0.40 to greater than 200 kilodaltons (kDa). Both antibodies reacted strongly with three polypeptide bands of 182 kDa, 118 kDa, and 70 kDa. Only mitotic cells exhibited the protein bands that were recognized by the antibodies. All these bands were found to be phosphoproteins as shown by 32P labeling and autoradiography and their removal by alkaline phosphatase treatment.

Animals↗
PubMed1983

Narcotics and spasm of the sphincter of Oddi. A retrospective study of operative cholangiograms.

The operative cholangiograms of 112 patients undergoing elective cholecystectomy were reviewed independently and retrospectively by two radiologists who were not aware of the anaesthetic technique used. Fifty four patients who received opioid drugs either pre- and/or intra-operatively comprised one study group whilst 58 patients who received no opioids comprised the other. Spasm of the sphincter of Oddi was observed in two patients in the opioid group and in one patient in the non-opioid group. The use of opioid drugs as part of the anaesthetic management for cholecystectomy did not appear to interfere with the radiological interpretation of operative cholangiography nor to increase the low incidence of spasm of the sphincter of Oddi.

Adolescent↗
PubMed1983

Leukemic cell colony formation in soft agar by bone marrow cells and peripheral blood cells from untreated acute leukemia patients.

An in vitro culture technique for colony formation of marrow cells and peripheral blood cells from untreated acute leukemia patients and from patients in relapse is described. The colonies from bone marrow cells of an untreated acute myelogenous leukemia (AML) patient were demonstrated to be of leukemic origin by cytogenetic analysis. Cells obtained from colonies of leukemic origin contained the human malignancy-associated nucleolar antigen (HMNA) as detected by indirect immunofluorescence. This nucleolar antigen was not present in marrow or peripheral blood cells or cells from colonies of marrow from hematologically normal individuals. Colonies could be grown from over 70% of the marrow and peripheral blood samples from untreated acute leukemia patients. The median number of colonies obtained was 75 per 10(5) marrow cells from patients with AML. In 1/3 of the cases an increased number of colonies could be grown from marrow cell suspensions kept in liquid culture for 5 days. This is indicative of the proliferative capacity of the colony forming cell population. This assay may be useful for detection of residual clonogenic leukemic cells in marrow and peripheral blood cell suspensions.

Adult↗
PubMed1982

Patient administration of I.V. buprenorphine for postoperative pain relief using the "Cardiff" demand analgesia apparatus.

In 51 patients undergoing elective abdominal surgery, analgesia was provided for the first 24 h after surgery by bolus injections of buprenorphine 0.1 or 0.2 mg given i.v. on patient demand using a patient-operated syringe driver (the "Cardiff" palliator). Excellent analgesia was reported by 47 patients. Four elderly patients had difficulty in operating the demand apparatus. In two other patients, clinically significant ventilatory depression necessitated abandoning the trial. Although there was a high degree of patient and staff acceptance of the method, the potential for ventilatory depression emphasizes the need for close observation of patients receiving i.v. opioids by this technique.

Adult↗
PubMed1981

Warm peritoneal dialysis in the management of accidental hypothermia: report of five cases.

Five patients with accidental hypothermia are reported. Admission rectal temperatures ranged from 24 degrees C to 31.7 degrees C and two patients had suffered circulatory arrest. Ages ranged between 25 and 77 and predisposing factors included alcoholism, gluterthimide poisoning, pancreatitis and cerebro-vascular accident. Along with respiratory and circulatory management in an intensive care unit the patients were actively rewarmed by peritoneal dialysis with fluid at 37 degrees C. Rewarming was rapid, smooth and free of complications. All five patients made a good recovery.

Adult↗
PubMed1981

Aural thermometry during profound hypothermia.

External auditory canal temperature changes during profound hypothermia were studied experimentally in ten dogs and clinically in 20 patients undergoing open-heart surgery. The results were compared with nasopharyngeal and lower oesophageal temperatures. Tympanic membrane temperature provided a better approximation to brain temperatures measured in four dogs to below 20 degrees C than did either of the other two methods. In patients, auditory canal temperature showed less variability with respect to oesophageal temperature and fell at a faster rate than did nasopharyngeal temperature. It did not appear to be subject to positional or other artefacts but four patients showed evidence of auditory canal trauma. The precise relationship between auditory canal or tympanic membrane temperature and brain temperature during profound hypothermia is not established. Routine otoscopic examination should accompany the use of an ear probe.

Adolescent↗
PubMed1981

Spinal anaesthesia or general anaesthesia for emergency hip surgery in elderly patients.

One hundred and thirty-two elderly patients undergoing emergency hip surgery were randomly allocated to receive subarachnoid block (SAB) or general anaesthesia (GA). Using the 125.I fibrinogen uptake test, deep vein thrombosis was found to occur in 17 of 37 patients in the SAB group and 30 of 39 patients in the GA group (P 0.05). Blood loss was 513 ml (+/- SEM 44) in the SAB group and 714 ml (+/- SEM 67) in the GA group (P less than 0.01). Hypoxaemia was present preoperatively (mean PaO2 9.2 kPa). Immediately following general anaesthesia, the mean fall in PaO2 was 0.86 kPa compared with preoperative values but only 0.16 kPa following subarachnoid block (P less than 0.01). At 24 hours postoperatively the fall in PaO2 was similar in both groups and recovered only slowly during the first week. Twelve patients died, three in the SAB group and nine in the GA group. This difference in mortality was not statistically significant.

Aged↗