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Biomedical subjects

M Browne

Publications and source records attributed to M Browne.

At least 55 records · Page 3Linked to original sources
PubMed1992

[Results of multicenter evaluation of reagents for determination of sodium, potassium and chloride ions using enzyme activation].

We present the results of a multicentre evaluation with Boehringer Mannheim/Hitachi instruments of new "enzymatic" methods for the determination of Na+, K+, and Cl- in serum or plasma. The between-day coefficient of variation was less than 1.4% (Na+), less than 2.6% (K+) and less than 1.7% (Cl-). The linear range of the assays were at least 80 to 200 mmol/l (Na+), 1.5 to 17 mmol/l (K+) and about 30 to at least 200 mmol/l (Cl-). The comparisons with routine flame atomic emission spectrometry and coulometry showed a satisfactory agreement of the test results. The "enzymatic" assays are insensitive to even grossly elevated levels of bilirubin and lipids (sodium, potassium, and chloride assays), NH4+ (potassium assay) and amylase (chloride assay). Interference by various drugs was not detected. Since the new methods can easily be adapted to photometric clinical chemistry instruments, they represent a valuable alternative to the use of ion-selective electrodes, flame atomic emission spectrometry and coulometry.

Calibration↗
PubMed1992

Evidence of cytotoxic T-cell destruction of epidermal cells in human graft-vs-host disease. Immunohistology with monoclonal antibody TIA-1.

A newly described mouse monoclonal IgG1 antibody, TIA-1, binds serine esterase-positive granule membranes of cytotoxic human T cells and is a candidate for an effector molecule involved in T-cell cytolytic mechanisms analogous to those of the perforin system. We performed immunohistologic studies on frozen human skin (n = 5) and lip (n = 21) sections as well as on control frozen sections of tonsils, purified cytolytic T (CD8) cells, and B cells using an indirect immunoperoxidase system. We found a strong association of TIA-1+ cells with CD8+ cells invading the epidermis in lip and skin lesions of graft-vs-host disease in human marrow allograft recipients, as well as a sharp geographic association of TIA+ lymphocytes with CD8+ regions in human tonsil sections. Double staining of CD8 and TIA-1 antigens with fluorescein isothiocyanate and Texas red confirmed that 80% to 90% of the CD8 cells were TIA-1+ in the epidermal infiltrates. Leu-7 activity (natural killer cell) was minimal and found in only three of 17 lip biopsy specimens. These data provide new evidence that direct cytolytic attack by donor T lymphocytes is the mechanism of epithelial target cell killing in human graft-vs-host disease.

Adolescent↗
PubMed1991

Preparatory brain potentials in major depressive disorder.

1. Psychomotor slowing in depression is frequently reflected by delayed reaction times (RT). 2. The role of central arousal mechanisms in response slowing was examined by comparing scalp-recorded slow negative potentials of depressed patients with normal controls in two separate studies. 3. Varying fore-warned RT conditions elicited contingent negative variation (CNV) waveforms and the resultant mid-point amplitudes of these waveforms together with orienting (O-wave), expectancy (E-wave) and post-imperative negative variation (PINV) component amplitudes and sensory evoked responses (N1, P2) were compared between groups. 4. RTs were significantly slowed in depressed patients and the patient group exhibited consistently larger PINV amplitudes. Depending on the RT condition, patients also exhibited larger mid-point CNV amplitudes and smaller N1 and P2 amplitudes.

Adult↗
PubMed1991

Amphotericin B vs high-dose ketoconazole for empirical antifungal therapy among febrile, granulocytopenic cancer patients. A prospective, randomized study.

We compared high-dose ketoconazole (800 mg/kg per day, orally) with amphotericin B (0.5 mg/kg per day, intravenously) for empirical antifungal therapy in a prospective, randomized study of persistently or recurrently febrile granulocytopenic cancer patients. Among 97 patients eligible for empirical antifungal therapy, 20 (21%) of these patients were ineligible for randomization to ketoconazole treatment because of their inability to tolerate oral medications. Among 72 patients eligible for randomization, 64 were assessable (32 in each arm of the study). Five of six patients with proved fungal infections who were randomized to receive ketoconazole treatment required crossover to amphotericin B treatment because of progressive infection. The conditions of three of these five patients improved after receiving amphotericin B. The frequency of transaminase elevation was higher in those receiving ketoconazole, while the frequency of azotemia was higher in those receiving amphotericin B. Bioavailability of ketoconazole was unpredictable. Amphotericin B remains the drug of choice for empirical antifungal therapy in granulocytopenic patients; whereas, lack of a parenteral formulation, ineffectiveness against proved mycoses, and unreliable bioavailability preclude high-dose ketoconazole from being an appropriate compound for this purpose.

Adult↗
PubMed1990

Performance tests and quality control of cathode ray tube displays.

Spatial resolution, noise, characteristic curve, and absolute luminance are the essential parameters that describe physical image quality of a display. This paper presents simple procedures for assessing the performance of a cathode ray tube (CRT) in terms of these parameters as well as easy set up techniques. The procedures can be used in the environment where the CRT is used. The procedures are based on a digital representation of the Society of Motion Pictures and Television Engineers pattern plus a few simple other digital patterns. Additionally, measurement techniques are discussed for estimating brightness uniformity, veiling glare, and distortion. Apart from the absolute luminance, all performance features can be assessed with an uncalibrated photodetector and the eyes of a human observer. The measurement techniques especially enable the user to perform comparisons of different display systems.

Data Display↗
PubMed1990

Lithium as an adjunct in the treatment of major depression.

This paper reports a double-blind cross-over study (1) to investigate the efficacy of lithium carbonate to produce rapid relief of major depression in patients who were previously unresponsive to at least 4 weeks of antidepressant therapy; (2) to study the effect of acute lithium administration on antidepressant blood levels. In contrast to other studies, lithium was found to be no more effective than placebo. The effect of lithium adjunct on antidepressant levels was not significant.

Antidepressive Agents↗
PubMed1988

Antidepressant plasma levels and clinical response in depressed patients treated with oxaprotiline and doxepin.

Relationship between plasma levels of a new tetracyclic antidepressant oxaprotiline and a tricyclic antidepressant doxepin, the clinical response and side-effects was studied in 30 patients with primary endogenous depression. Patients were treated following a placebo wash-out period with gradually increasing doses (75, 150, 225 mg/day) of either drug for 4 weeks. The clinical outcome (percentage of responders and of decrease in HAMD scores) was similar in groups of patients treated with the two drugs. No significant relationship was found between the plasma levels of the parent drugs (oxaprotiline or doxepin) and a measure of clinical response (HAMD scores). However, in patients treated with doxepin, there was a significant relationship between the therapeutic response and plasma levels of the drug's metabolite, desmethyldoxepin. In addition, side-effects were more frequently observed in patients with higher plasma levels of both drugs. Incidences of anticholinergic side-effects was significantly higher in patients treated with doxepin.

Adult↗
PubMed1987

Pete's story.

Explore the source record for details and available documents.

Humans↗
PubMed1987

Measurement of radiographic changes occurring in rheumatoid arthritis by image analysis techniques.

We have applied image analysis techniques to serial measurements of bone contour in standard radiographs of single small joints of the hands in subjects with rheumatoid arthritis (RA) and controls. Adequate reproducibility was shown in 20 controls radiographed twice over a six month period. The technique showed significant changes in a proximal interphalangeal joint of 13 of 15 patients with RA studied over periods of three to 10 months. In further serial studies in selected small joints of RA hands significant changes could be shown as early as four months. These results justify further development of these techniques to allow their full scale evaluation in multiple joints in patients with RA receiving long term drug therapy.

Adult↗
PubMed1987

Treatment of major affective disorder with fluvoxamine.

A placebo-controlled, double-blind study of 63 inpatients with major affective disorder was performed to compare the safety and efficacy of fluvoxamine and imipramine. Results indicate that fluvoxamine and imipramine are superior to placebo and demonstrate a trend toward superiority of fluvoxamine over imipramine. Fluvoxamine was generally well tolerated in most patients.

Adult↗
PubMed1986

A randomized trial comparing ceftazidime alone with combination antibiotic therapy in cancer patients with fever and neutropenia.

To assess the efficacy of single-agent therapy relative to standard combination antibiotic therapy for the initial management of fever and neutropenia in cancer patients, we conducted a randomized trial comparing ceftazidime alone with a combination of cephalothin, gentamicin, and carbenicillin. Of 550 evaluable episodes of fever and neutropenia, 282 were treated with ceftazidime alone and 268 with the combination. All episodes were evaluated for responses at 72 hours after the start of treatment and at resolution of the neutropenia. Of the patients with unexplained fever who were given ceftazidime alone, 99 percent were alive at 72 hours and 98 percent were alive when the neutropenia resolved, as compared with 100 percent and 98 percent, respectively, of those given combination therapy. Of the patients with documented infection who were given ceftazidime alone, 98 percent were alive at 72 hours and 89 percent when the neutropenia resolved, as compared with 98 percent and 91 percent, respectively, of those given combination therapy. The majority of episodes of documented infection in both treatment groups necessitated additional antimicrobial treatment or other modifications of the initial regimen, as compared with only 22 percent of the episodes of unexplained fever. We conclude that initial single-agent therapy with certain beta-lactam antibiotics is a safe alternative to standard combination antibiotic therapy, although patients with documented infection or protracted neutropenia are likely to require additional or modified treatment.

Adolescent↗
PubMed1985

New beta-lactam antibiotics in granulocytopenic patients. New options and new questions.

Infectious complications are a frequent cause of morbidity and, at many centers, the major cause of death in patients with cancer. The increased risk and severity of infectious sequelae result from profound alterations in normal host defenses that occur secondary to the underlying malignancy and the treatment thereof. During the last decade, early empiric antibiotic therapy has become standard practice in the initial management of febrile granulocytopenic patients and has contributed significantly to the improved outcome among patients undergoing cancer therapy. Although early death due to unsuspected or inadequately treated bacterial infection has been largely overcome, new problems--also with life-threatening implications--have emerged. As the use of cancer chemotherapy continues to increase, new populations of patients are being placed at increased risk of infection. Defining the host and environmental factors that contribute to this risk assumes central importance for delineating those patients who require the most intense surveillance. Changing medical practices (e.g., increased use of indwelling catheters) have contributed to the emergence of new pathogens. Recent drug developments (e.g., the third-generation cephalosporins and extended-spectrum penicillins) offer new treatment options, as well as generate controversy and confusion. For example, authorities disagree on the optimal duration and modifications in treatment that are required by cancer patients who remain granulocytopenic and who thus are at continued risk of multiple infectious episodes or superinfections. A question of current interest is whether combination therapy with synergistic agents is important in light of the development of the third-generation cephalosporins and extended-spectrum penicillins. Several of these new antibiotics have an exceedingly broad spectrum of activity that includes Pseudomonas aeruginosa, as well as Enterobacteriaceae, Serratia, Citrobacter, indole-positive Proteus, and anaerobes (including Bacteroides fragilis). However, the third-generation cephalosporins are not as active against staphylococci and streptococci as are the first-generation cephalosporins, and none is effective against enterococci. Nonetheless, these agents achieve serum levels that can be 10 to 100 times greater than the minimal inhibitory and bactericidal concentrations of gram-negative bacteria, raising the possibility that these drugs might be effective as single agents. The advantages of the third-generation cephalosporins are their minimal toxicity and long serum half-lives.(ABSTRACT TRUNCATED AT 400 WORDS)

Agranulocytosis↗
PubMed1985

Prospective randomized study of open lung biopsy versus empirical antibiotic therapy for acute pneumonitis in nonneutropenic cancer patients.

Diffuse pulmonary infiltrates and acute respiratory compromise frequently occur in patients with cancer who are undergoing chemotherapy, and treatment remains controversial. We initiated a prospective randomized trial in 22 nonneutropenic patients to compare the efficacy of immediate open lung biopsy with that of empirical trimethoprim-sulfamethoxazole and erythromycin therapy with delayed open lung biopsy if no clinical improvement occurred after 4 days of therapy. Diagnoses included non-Hodgkin's lymphoma (15 patients), T-cell lymphoma (2), acute lymphoblastic leukemia (3), Hodgkin's disease (1), and breast cancer (1). The median age was 40 years, and fever (18) and tachypnea (13) were the most frequent signs. Median room air arterial oxygen tension in 18 hypoxic patients was 53 mm Hg; 19 patients had diffuse pulmonary infiltrates. Eight of the 10 patients randomized to empirical antibiotic therapy showed improvement after 4 days. The 2 patients whose condition did not improve and who underwent delayed open lung biopsy had Pneumocystis carinii pneumonia. One of them did show improvement, and the other died of respiratory failure. Time to clinical resolution in the 9 surviving patients was 14 days; 4 required prolonged ventilation (longer than 24 hours). Findings for the 12 patients randomized to immediate open lung biopsy were P. carinii pneumonia in 7 and nonspecific pneumonitis in 5; there were 3 deaths related to open lung biopsy. Time to resolution in the surviving patients was 13 days for those with P. carinii pneumonia and 5 days for those with nonspecific pneumonitis; 7 required prolonged ventilation.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗