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Biomedical subjects

W Miller

Publications and source records attributed to W Miller.

At least 199 records · Page 11Linked to original sources

Optimal alignments in linear space.

Space, not time, is often the limiting factor when computing optimal sequence alignments, and a number of recent papers in the biology literature have proposed space-saving strategies. However, a 1975 computer science paper by Hirschberg presented a method that is superior to the new proposals, both in theory and in practice. The goal of this paper is to give Hirschberg's idea the visibility it deserves by developing a linear-space version of Gotoh's algorithm, which accommodates affine gap penalties. A portable C-software package implementing this algorithm is available on the BIONET free of charge.

Algorithms↗

Clinical photography utilizing office staff: methods to achieve consistency and reproducibility.

This report describes solutions to common problems incurred in clinical photography for facial and cosmetic surgery and focuses on the physician who utilizes office staff to obtain photographs. Issues addressed include space and room requirements, camera and lens, lighting and shadows, pose, retrieval, and quality control. The methods and systems described are aimed at assisting the physician in obtaining consistent, reproducible, quality pre- and postoperative photographs.

Humans↗

A cause-specific hazard rate analysis of prognostic factors among 199 adults with acute lymphoblastic leukemia: the Memorial Hospital experience since 1969.

Results of a multivariable analysis of prognostic factors are reported for 199 previously untreated adults with acute lymphoblastic leukemia (ALL). These patients have long-term follow-up, and the probability of cure is estimated at approximately 35%. The cause-specific hazard rate analysis found lower rates of achieving complete remission (CR) in patients with WBC greater than 10,000/microL, AUL (undifferentiated) morphology, and older age. Since these patients required additional time to respond, fewer of them actually achieved CR. Characteristics directly associated with a higher rate of death during induction therapy due to severe bone marrow suppression were low serum albumin concentration (less than or equal to 3.5 g/dL), age greater than 50 years, acute undifferentiated leukemia (AUL) morphology, low Karnofsky performance status, and weight loss greater than 5%. Factors associated with a higher rate of relapse were WBC greater than 20,000/microL, non-T cell ALL, age greater than 60 years, Ph' + ALL, and time to achieve CR greater than 5 weeks. These criteria were used to identify patients at high risk of relapse. In addition, the predictive value of high WBC was found to disappear by 18 months of continuous CR. Finally, the rate of death following first relapse was higher in patients with a short first remission duration, high percentage weight loss at initial diagnosis, and older age. In summary, factors associated with a higher rate of death during attempted induction (ie, low albumin, high percent weight loss, and poor performance status) had no association with the patient's ability to remain relapse-free. Conversely, factors correlating with more extensive or resistant disease (ie, high WBC, null or B cell ALL, or Ph' + ALL) showed no association with the ability to tolerate therapy. Thus, a less toxic but more effective induction regimen is needed for patients with a poor clinical status, whereas a more intensive form of therapy appears warranted for patients presenting with more extensive or resistant disease.

Adult↗

Hysteroscopic correction of cornual occlusion with resultant term pregnancy.

Hysteroscopic correction of proximal cornual occlusion is possible in some cases using a simple ureteral stent. This allows re-establishment of tubal patency in selected cases with the possibility for occurrence of intrauterine pregnancy without the need for major surgery. The case presented represents the first reported term pregnancy in a well-documented case of this type.

Adult↗

Therapy of chronic myelogenous leukemia with allogeneic bone marrow transplantation.

From December 1982 to January 1986, 57 patients received allogeneic bone marrow transplantation as therapy for Philadelphia chromosome (Ph') positive chronic myelogenous leukemia (CML). All patients were prepared for transplantation with cyclophosphamide 60 mg/kg (day -6, -5) and fractionated total body irradiation, 165 cGy twice daily (day -4, -3, -2, -1) and received major histocompatibility (MHC) matched donor marrow (day 0). All patients received graft-v-host disease (GVHD) prophylaxis with methotrexate, prednisone, and either antithymocyte globulin (ATG) (55 patients) or OKT3 infusion (two patients). The projected survival of 29 chronic phase patients is 64% (95% confidence interval [Cl] 42% to 86%); and of 28 accelerated phase patients, 30% (95% Cl, 12% to 48%) at 30 months (P = .005). Multivariate regression analysis of pretransplant patient characteristics demonstrated that the presence of chronic phase and age less than 30 years were the only prognostic features studied that independently predicted survival. No evidence of persistent or recurrent disease has occurred in chronic phase patients; however, reappearance of the Ph' was observed in seven accelerated-phase patients, and hematologic relapse occurred in three of these seven patients. The incidence of grade II to IV acute GVHD is 63% (95% Cl, 50% to 76%) at 100 days, and that of extensive chronic GVHD is 53% (95% Cl, 33% to 74%) at 30 months. The median Karnofsky activity assessment of survivors is 100% (range, 60% to 100%), and all activity assessments less than 100% can be attributed to complications of GVHD. Bone marrow transplantation therapy for CML after preparation with cyclophosphamide and fractionated total body irradiation results in a high proportion of disease-free survival in chronic-phase patients. Survival in accelerated phase is significantly worse and is associated with relapse. GVHD has emerged as a significant cause of morbidity and mortality in this study.

Antigens, Surface↗

Therapy of severe aplastic anemia in young adults and children with allogeneic bone marrow transplantation.

During an 8-year period, 28 young adults (median age 27 years) and 30 children (median age 10 years) with severe aplastic anemia have received allogeneic bone marrow transplantation (BMT) from major histocompatibility locimatched sibling donors after preparation with cyclophosphamide and total lymphoid irradiation (TLI). All recipients were previously transfused. Comparison of post-bone marrow transplantation events in adults and children reveals equivalent median time to engraftment, median duration of hospitalization, median Karnofsky assessment of activity, and equivalent low rejection rate. Although the incidence of moderate and severe acute graft-v-host disease (GVHD) and of extensive chronic GVHD was greater in adults than in children, the projected survival at 4 years of adults (67%; 95% confidence interval [CI] 49% to 85%) and of children (73%; 95% CI 57% to 89%) was equivalent. All survivors are transfusion-free and have normal peripheral blood counts. One of 28 adults and 2 of 30 children have experienced rejection, and 1 of these patients survives after a second transplant. No malignancies have been identified following transplantation. An unexpectedly high incidence of hypothyroidism has been detected and may be attributable to preparation of recipients with TLI. Therapy of severe aplastic anemia with allogeneic BMT after preparation with cyclophosphamide and TLI offers a high rate of transfusion-free survival and a low rejection rate in previously transfused young adults and children.

Acute Disease↗

Phenotypic and functional evaluation of suppressor cells in normal pregnancy and in chronic aborters.

To evaluate the potential role of immunoregulatory cells modulating the maternal immunologic response during pregnancy, we carried out phenotypic and functional studies in patients with normal obstetrical histories during each trimester and in patients with chronic idiopathic spontaneous abortions. Using monoclonal antibodies (Ortho), total numbers of T cells (T3+) and T4+ cells progressively increased during pregnancy (compared to nonpregnant controls) and then declined in the third trimester. Increased percentages of T8+, T10+, and Ia+ cells were found in the third trimester. The relative decline in numbers of T4+ cells, with increased numbers of T8+ cells, led to a significantly reduced T4/T8 ratio in the third trimester. Histamine receptors on T cells were quantitated by an immunofluorescent technique. Significantly reduced numbers of H1-type receptors were noted during the second trimester of pregnancy and this was associated with a decreased H1/H2 ratio. Functionally, histamine-induced suppression was measured in a lymphocyte proliferation assay. Patients in the first and second trimester of pregnancy had greater histamine-induced suppression of phytohemagglutinin (PHA)-stimulated proliferation at high concentrations of histamine (10(-3) to 10(-7)) but less suppression at the lower concentrations (10(-9) to 10(-11) M), compared to nonpregnant controls. In contrast, patients studied in the third trimester failed to respond to any concentration of histamine. MLC-induced suppressor activity was generated by incubating the maternal cells with either paternal or third-party mononuclear cells for 2 or 6 days and assaying the cell-free supernatant for its suppressive effects on PHA-stimulated proliferation. Maternal responses to paternal cells did not result in significant suppression in 2-day supernatants during any trimester but by 6 days the suppressive activity was equivalent to non-pregnant controls in patients during the first and second trimester. Maternal responses to third party cells was greater during the second trimester than either the first or third trimesters in both 2- and 6-day supernatants. Patients with histories of chronic idiopathic spontaneous abortions, who were not pregnant at the time of study, exhibited normal numbers of T-cell subsets and T4/T8 ratios. Numbers of both H1 and H2 receptor bearing T cells were proportionally reduced, resulting in a normal H1/H2 ratio. Despite having decreased numbers of H1 and H2 receptor bearing cells, histamine-induced suppression of PHA-stimulated proliferation was comparable to nonpregnant controls over the concentration range (10(-3) to 10(-11) M) employed.(ABSTRACT TRUNCATED AT 400 WORDS)

Abortion, Habitual↗

Initial evaluation of the use of the potassium-titanyl-phosphate (KTP/532) laser in gynecologic laparoscopy.

A new surgical laser, the potassium-titanyl-phosphate 532 nm laser (Laserscope, Santa Clara, CA) has recently become available for investigative procedures in gynecology. This article reports initial investigation of this laser energy at laparoscopy with the use of a flexible fiberoptic delivery system in rabbits and patients with endometriosis. Tissue effects on peritoneal structures of rabbits with laparoscopic firing of this new laser demonstrated the ability to accomplish surface vaporization without bowel perforation or penetration greater than 2 mm. In ten patients with pelvic endometriosis and pain, effective laparoscopic vaporization of implants has been safely accomplished with ease. Early follow-up revealed symptomatic improvement in all patients. This new laser is easy to use laparoscopically, appears safe in early investigations, and effectively reduces early postoperative pain associated with pelvic endometriosis.

Animals↗

Nonlymphomatous lymphoid disorders of the lung.

Nonlymphomatous lymphoid disorders of the lung consist of several entities with varied histology and clinical behavior. On the basis of histologic appearance, six lesions can be identified. They include Castleman's disease, plasma-cell granuloma, pseudolymphoma, lymphocytic interstitial pneumonitis, angioimmunoblastic lymphadenopathy, and lymphomatoid granulomatosis. These conditions in 22 patients, their radiologic and histopathologic features, and their relationship to the malignant lymphomas are discussed. Although a radiographic diagnosis may be suggested, overlapping features mandate open-lung biopsy in most instances. The frequent evolution toward malignant lymphoma with lymphomatoid granulomatosis and pseudolymphoma necessitates close follow-up and sometimes aggressive therapy.

Granuloma, Plasma Cell↗

Cytomegalovirus infection after bone marrow transplantation: an association with acute graft-v-host disease.

Among 181 patients undergoing allogeneic bone marrow transplantation over a five-year period (1978 through 1982), cytomegalovirus (CMV) infection was a frequent and often lethal complication. Recipient pretransplant serology was the most important predictor of posttransplant CMV infection. CMV infection occurred in 26/137 seronegative recipients and in 28/44 seropositive recipients (P less than .001). Among patients who developed CMV infection, the time to infection was identical in seronegative and seropositive patients (median, 71 days post transplant). Bone marrow donor CMV serology did not significantly influence CMV infection rate. CMV infection was strongly associated with acute graft-v-host disease (AGVHD), occurring in 34/81 patients with AGVHD and 20/100 without GVHD (P less than .001). AGVHD preceded CMV infection by 33.7 days (mean) in patients developing both complications. Patients who developed CMV infections had also received more cellular blood products post transplant. These data suggest that CMV infection may occur through reactivation of latent virus (in seropositive recipients) or through exogenous exposure, possibly through transfused blood products, but that duration of immunoincompetence may be more critical than route of exposure in timing of clinically evident CMV infection. Prophylaxis tailored to the likely infectious source and more effective GVHD prevention both may be critical in preventing CMV infection after bone marrow transplantation.

Acute Disease↗

Pneumothorax during positive-pressure mechanical ventilation.

The hemodynamic and respiratory effects of unilateral pneumothorax were studied during positive-pressure mechanical ventilation in five sheep. The sheep were anesthetized, intubated, and placed on mechanical ventilation with positive end-expiratory pressure (5 cm H2O). After baseline studies, including chest roentgenograms, were taken, increments of air were injected into the right pleural cavity. Measurements were repeated at pneumothoraces of 500, 1,000, and 1,500 ml. There was a steady fall in cardiac output (p less than 0.02) at pneumothoraces of 1,000 and 1,500 ml. The decrease in cardiac stroke volume paralleled that of cardiac output. Heart rate rose (p less than 0.05) at a pneumothorax of 1,500 ml. There appeared to be a linear relationship between the percent increase in pneumothorax as estimated by roentgenogram and the percent fall in cardiac output (r = 0.991). There was a steady rise in mean pulmonary arterial, pulmonary arterial capillary wedge, superior vena caval, and inferior vena caval pressures, although the changes in inferior vena caval pressure were not statistically different from baseline. Peak airway pressure increased from baseline at pneumothoraces of 1,000 and 1,500 ml. Both right and left end-expiratory intrapleural pressures increased and were statistically different (p less than 0.01) from baseline. However, there was a substantially greater rise in right intrapleural pressure than left. Arterial oxygen tension remained physiological throughout the study. This study indicates that cardiac output decreases as the amount of pneumothorax increases in sheep during mechanical ventilation. This study also demonstrates that, during positive-pressure mechanical ventilation, a relatively benign-appearing pneumothorax by chest roentgenogram may be associated with a significantly depressed cardiac output. In addition, arterial oxygen tension may not be useful in predicting the onset of pneumothorax during mechanical ventilation.

Animals↗

MR imaging of the mediastinum: a retrospective comparison with computed tomography.

Magnetic resonance (MR) imaging of the mediastinum was performed with a 0.12 T resistive magnet and compared with the results of CT. On T1 weighted images with partial saturation technique, soft tissue masses, lymphadenopathy, lipomatosis, and vascular anatomy were comparable with MR and CT imaging in 19 of 30 patients (63.3%). In the remaining 11 patients only slight differences between the two modalities were observed. Our experience suggests that MR imaging at low field strength is equivalent to CT in the morphologic assessment of the mediastinum without the need for administration of intravenous contrast medium or exposure to ionizing radiation.

Humans↗