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Biomedical subjects

K Miller

Publications and source records attributed to K Miller.

At least 523 records · Page 29Linked to original sources

Interaction of whole-body hyperthermia and irradiation in the treatment of AKR mouse leukemia.

Whole-body hyperthermia (WBH) to 41-42 degrees C combined with fractionated total-body irradiation (TBI) was studied in mice with transplanted AKR leukemia. Mice treated with both TBI and WBH survived longer than mice treated with either modality alone. From other groups of similarly treated mice the spleens were removed, weighed, and assayed for their content of leukemic colony-forming units (CFU) by injecting single-cell suspensions into normal syngeneic recipients. Using this methodology it was determined that the thermal enhancement ratio for WBH combined with TBI was 1.6, and that enhanced killing of leukemia cells occurred irrespective of the sequence of WBH and TBI. Data are presented which relate variables, such as duration of WBH or heating time to target temperature, to the response of neoplastic disease. The implications of these preclinical findings to clinical trials are discussed.

Animals↗

Heat stroke New Orleans style.

An in-depth discussion of Classic Heat Stroke (CHS) and Exertional Heat Stroke (EHS) Syndromes occurred during morning report at a large metropolitan teaching institution during a New Orleans heat wave. The opportunity arose to compare the syndromes via case reports of two patients admitted the same day to the same housestaff teams. The physiology of the hyperthermic state, maladaptions predisposing the hyperthermic syndrome and current heat stroke management updates are reviewed in detail. This report should compel the reader to remain attentive to the subtleties and differences presented in life-threatening high-heat and humidity-related illnesses and how to act rapidly and prudently in management of the illnesses.

Adult↗

Proliferation kinetics of human B- and T-lymphocytes.

Human peripheral blood B- and T-lymphocytes, highly purified by immunological methods, were supplemented with gamma-irradiated unseparated autologous mononuclear cells to restore helper functions and stimulated with pokeweed mitogen and phytohaemagglutinin, respectively. Proliferation kinetics of the cell populations were investigated using 5-bromodeoxyuridine (BrdU) labelling of the cell cultures and chromosome preparation at different times after stimulation. The percentages of metaphase cells having replicated for one, two or three generations in the presence of BrdU were determined following sister chromatid differential staining. In all donors, the changes in these percentages were faster in B- than in T-lymphocytes, indicating a longer cell cycle time in the latter population.

Adult↗

Detection of Gardnerella vaginalis in vaginal specimens by direct immunofluorescence.

The preparation of a fluorescein-labeled Gardnerella vaginalis polyclonal antibody is described, and its usefulness is assessed for the detection of this microorganism in vaginal samples obtained from 263 women attending the gynecological department of a general hospital, 66 of whom harbored an intrauterine device. The direct immunofluorescence technique was positive for G. vaginalis in 21% of the specimens, whereas only 12.5% of the total bacteriological cultures were positive. The frequency was higher in patients harboring intrauterine devices since 34.8% exhibited positive immunofluorescence and 30.3% exhibited positive cultures.

Animals↗

Vitamin A acetate as a regulator of accessory cell function in delayed-type hypersensitivity responses.

Mice fed on a vitamin A acetate (VAA)-supplemented diet respond to concentrations of oxazolone which are too low to elicit contact sensitivity on a standard diet. This study has investigated whether enhanced responsiveness could be due to VAA-induced changes in antigen-presenting cell function. The draining lymph nodes were used as the source for accessory cell populations, and cells from control and sensitized mice on either standard or VAA diet were compared in syngeneic and allogeneic responses. Their ability to induce delayed-type hypersensitivity reactions was also compared. There was no qualitative difference between accessory cells from the standard and VAA-fed groups respectively, but there was already a striking quantitative increase in the number of accessory cells which correlated with augmented sensitization. These findings are consistent with the postulate that the effect of VAA may be associated with regulation of accessory cell function, and that susceptibility to contact sensitization can be modified by quantitative changes in antigen presentation.

Adjuvants, Immunologic↗

Isolation of an endocytic compartment from A431 cells using a density modification procedure employing a receptor-specific monoclonal antibody complexed with colloidal gold.

Our objective was to isolate a prelysosomal compartment involved in receptor-mediated endocytosis in human epidermoid carcinoma (A431) cells. The isolation protocol involves density modification of endosome elements in A431 cells, caused by the receptor-dependent binding and internalization at 20 degrees C of colloidal gold-transferrin receptor antibody (B3/25) particles. The use of 125I-labelled gold-B3/25 provides a radioactive marker for the endosome compartment, the major peak being recovered at the bottom of a continuous sucrose gradient at a density of 1.23g ml-1. Enzyme markers characteristic of other cytoplasmic compartments are present only in negligible amounts in this fraction and L-[35S]methionine-labelling of the cells indicates approximately a 200-fold enrichment of 125I-labelled gold-B3/25 versus protein. Electron microscopy of the endosome-rich fraction reveals that we have isolated a highly purified population of small gold-containing vesicles and tubules from which the transferrin receptor can be immunoprecipitated using the B3/25 antibody. Gel electrophoresis and fluorography of L-[35S]-methionine-labelled cells suggests that these elements contain a characteristic profile of approximately 10 major proteins of which three appear to be specifically enriched. In cells incubated with [125I]transferrin, 12% of the ligand sediments with the gold-labelled elements. We conclude, therefore, that the components we have isolated play a role in the intracellular processing of the transferrin-transferrin receptor complexes.

Antibodies, Monoclonal↗

Enalapril: a well-tolerated and efficacious agent for the pediatric hypertensive patient.

Enalapril either alone or with a diuretic was administered to 15 children with various renal diseases and hypertension. Five were transplant recipients on multiple immunosuppressive agents. No adverse clinical or laboratory experiences were encountered except for mild proteinuria in two children, one of whom has evidence of chronic rejection. Enalapril effectively controlled blood pressure in all 15 patients when given once daily with or without food. Renal function improved in seven children. Six children are under excellent blood pressure control despite a reduction in the dose of enalapril. Two are currently on no medication, five require a diuretic, while one child is on an increased dose of enalapril.

Adolescent↗

Adverse effects of toxins and drugs on the surfactant systems.

Various inhaled or administered compounds have adverse effects on the surfactant system. In experimental animals quartz inhalation induces alveolar proteinosis. This condition may also be induced by amphiphilic drugs or through increases in surfactant apoproteins. In one experimental model, damage to Clara cells by a methyl-furan derivative led to an increase in extracellular surfactant levels without a change in whole lung pool size. A comparative study of the effects of nitrogen dioxide in the rat and hamster demonstrated differing effects on Clara cells, type II and surfactant levels. These and other studies demonstrate that the effects of chemicals and drugs on cells involved in surfactant synthesis, secretion and catabolism provide a sensitive indicator of incipient toxic effects in the lung.

Animals↗

Tandem duplication chromosome 21 in the offspring of a ring chromosome 21 carrier.

A direct tandem duplication chromosome 21 was found in a boy with Down's syndrome. The proband's mother and grandmother both carried a ring chromosome 21. The observed duplication chromosome in the child may be explained either by recombination between the maternal ring and the mother's normal chromosome 21 or by break of a double-sized ring chromosome 21.

Child, Preschool↗

[The ileal neobladder].

Currently we are witnessing an increase of interest in bladder substitution enterocystoplasty. The goal of this presentation is to describe operative technique and first clinical results of a ileal neobladder for total bladder replacement. Creation of a ileal neobladder for total bladder replacement is described in 11 patients. To achieve a low pressure system, disruption of directional bowel peristalsis with a longitudinal incision at the antimesenteric border of a 70 cm ileal segment is performed. A spherical pouch, the neobladder, is fashioned and anastomosed to the urethra. The ureters are implanted according to Le Duc and Camey. Videourodynamic studies during various postoperative phases demonstrate this neobladder to be a urinary reservoir with a capacity approximating that of a normal bladder, good compliance during filling by maintaining pressures lower than 30 cm water and no reflux. Eight of the 11 patients with the neobladder are completely dry day and night. Three are stress incontinent grade I. All 11 patients developed recognizable sensations of bladder distension closely simulating those of their earlier bladders. The use of this ileal neobladder in male patients undergoing radical cystectomy offers a stoma free alternative to urinary diversion resulting in a highly compliant low pressure bladder. A urodynamic comparison between the most recent developments (Kock-pouch, Camey, Mainz-pouch, "Le Bag") is made and this clearly shows the ileal neobladder to have several distinct advantages: the ileocolonic junction and the terminal ileum are saved; the operative technique is safe, simple and reliable (no Kock valve, no 180 degree rotation of the reservoir, simple antireflux technique); development of recognizable sensations of bladder filling in all cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗

A multicenter comparative trial of three-day norfloxacin vs ten-day sulfamethoxazole and trimethoprim for the treatment of uncomplicated urinary tract infections.

Two-hundred nine patients with symptoms of acute urinary tract infection and pyuria were randomized to 400 mg of administered norfloxacin twice daily for three days, or 800 mg of sulfamethoxazole and 160 mg of trimethoprim administered twice daily for ten days. Therapeutic outcome was assessed five to nine days and four to six weeks after treatment. The cure rates were 71/74 (96%) with norfloxacin and 81/81 (100%) with sulfamethoxazole and trimethoprim five to nine days after treatment. Only seven patients had a recurrence at the second follow-up visit; four in the norfloxacin group and three in the sulfamethoxazole and trimethoprim group. No isolates were resistant to norfloxacin, but three Escherichia coli were resistant to sulfamethoxazole and trimethoprim. Fifteen patients in each group reported a side effect during treatment. Two patients in the norfloxacin group and four patients in the sulfamethoxazole and trimethoprim group discontinued therapy due to an adverse effect. In this multicenter study, a three-day course of norfloxacin was as effective and safe as a ten-day regimen of sulfamethoxazole and trimethoprim in the treatment of acute uncomplicated urinary tract infections.

Acute Disease↗

Thrombocytopoietic response to immunothrombocytopenia in nude mice.

Thrombocytopoiesis was evaluated in T cell-deficient nu/nu mice and in T cell-replete nu/+ controls to determine if abnormalities would be associated with the deficiency of T cells. Mice were studied in the unperturbed steady state and after acute immunothrombocytopenia was induced by an injection of guinea pig antimouse platelet serum (APS). The state of thrombocytopoiesis was determined from platelet counts, megakaryocyte size, megakaryocyte number, and numbers of Meg-CFC. Splenic lymphocytes were evaluated by response to the mitogens bacterial lipopolysaccharide (LPS), phytohemagglutinin (PHA), and concanavalin A (Con A). Hematocrits, reticulocyte counts, leukocyte counts, marrow cellularity, GM-CFC, and BFU-E also were measured. Steady state thrombocytopoiesis was identical in nu/nu and nu/+ mice. In response to an injection of APS, acute thrombocytopenia was followed by macromegakaryocytosis and rebound thrombocytosis in mice of both genotypes. Splenic Meg-CFC increased in nude mice after APS or an injection of normal guinea pig serum (NGpS), and splenic GM-CFC increased after APS. Neither Meg-CFC nor GM-CFC increased in the spleens of nu/+ mice, but they showed early transient increases in bone marrow that did not occur in nu/nu mice. Sporadic, but weak, mitogenic responses to PHA or Con A were occasionally observed with nu/nu spleen cells, but these did not correlate with the state of thrombocytopoiesis. The results demonstrated that platelet production was normal in nu/nu mice and that megakaryocytopoiesis and platelet production responded to the stimulus imposed by acute immunothrombocytopenia. Increases in megakaryocyte size and platelet production occurred independently of changes in numbers of Meg-CFC, GM-CFC, or BFU-E. A normal complement of T cells appears to be unnecessary for normal platelet production and its augmentation in response to the stimulus of acute immunothrombocytopenia in vivo.

Animals↗

[Extracorporeal shock wave lithotripsy of a deep calculus of the ureter].

Until recently, extracorporeal shockwave lithotripsy (ESWL) was limited to ureteral calculi above the pelvic brim. A new positioning technique has now made it possible to use ESWL for stones in the lower ureter too. The overall success rate with 72 patients treated in our department from January through August 1986 was 91%. ESWL, as a noninvasive method, is preferable to invasive procedures for the treatment of distal ureteral calculi. This may lead to narrowing of the range of indications for ureteroscopy.

Adult↗

Sister chromatid exchange in highly purified human B and T lymphocytes.

Sister chromatid exchange (SCE) rates were determined in human peripheral blood B and T lymphocyte populations highly purified by immunologic methods. The purified populations were supplemented with gamma-irradiated unseparated autologous mononuclear cells to restore helper-functions and stimulated with pokeweed mitogen (PWM) and phytohemagglutinin (PHA), respectively. Measured at the different peaks of proliferation after identical bromodeoxyuridine (BrdU) incubation times, T lymphocytes showed significantly higher SCE frequencies than B lymphocytes. In both populations, different proliferation kinetics and a different minimal BrdU concentration for sister chromatid differentiation (SCD) were observed.

B-Lymphocytes↗