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Biomedical subjects

G Eckert

Publications and source records attributed to G Eckert.

At least 19 recordsLinked to original sources

In-office cancer-screening education of primary care physicians.

In a demonstration project, education representatives were trained to perform "academic detailing" of cancer control information for physicians and for staff members of family physicians' offices. One-hour visits were arranged at specific times so as to avoid disruption of patient care activities. The representatives led discussions of salient tissues regarding early detection of cancer at three sites (breast, colon-rectum, and prostate) and left relevant patient education materials. Seventeen visits were made to 11 practices involving 22 physicians and 85 staff members. Ten items were selected as evidence of favorable cancer control activities: ashtrays had been removed from the waiting room, patient information was displayed in a wall rack, medical records contained a method for prompting the physician about preventive or screening services that were due to be performed, a recall system reminded patients of services that were due to be performed, the receptionist was involved, the nurse was involved, American Cancer Society (ACS)-recommended services were used or had been added, the physician talked to other physicians about the visit discussions, services or materials had been requested from the local ACS unit, and staff members or physicians had volunteered to serve the ACS. The compliance rate was 35% at baseline. At post-intervention assessment, the compliance rate had increased by 35%, for a final compliance rate of 70%.(ABSTRACT TRUNCATED AT 250 WORDS)

American Cancer Society

Use of dabsylation, column switching and chiral separation for the determination of a renin inhibitor in rat, marmoset and human plasma.

A high-performance liquid chromatographic method with column switching was developed for the determination of the renin inhibitor Ro 42-5892/001, (S)-alpha-[(S)-alpha-[(tert.-butylsulphonyl)methyl]hydrocinnama mido]-N- [(1S,2R,3S)-1-(cyclohexylmethyl)-3-cylcopropyl-2, 3-dihydroxypropyl]imidazole-4-propionamide methanesulphonate (1:1), in rat, marmoset and human plasma, using a Nucleosil C8 120 (3 microns) stationary phase. Since the analyte and the internal standard are optical isomers, beta-cyclodextrin was used as a mobile phase constituent for their chiral separation. The method took advantage of the characteristics of dabsyl chloride derivatives, namely sensitivity, specificity and, particularly, stability, providing a quantification limit of 5 ng/ml. The accuracy (range of inaccuracy 1-13%) and the inter-assay precision (coefficient of variation range 1.8-9.1%) were acceptable. The method was successfully applied to toxicokinetic studies in rats and marmosets.

Animals

Pentamidine aerosol increases the number of alveolar macrophages in HIV-infected patients.

In order to determine the possible effect of aerosolized pentamidine on the cellular composition of the bronchoalveolar lavage fluid in HIV-infected patients, differential counts of 22 consecutive patients who had been rebronchoscopied after 3-19 months were reviewed. Eleven patients were started on pentamidine prophylaxis subsequent to their first presentation. Eleven patients had never taken pentamidine or had discontinued the prophylactic regimen. Compared to first bronchoscopy, the bronchoalveolar lavage (BAL) from patients on regular prophylaxis revealed a significant increase in absolute alveolar macrophage (AM) counts at second presentation (20.8 +/- 11.2 to 50.3 +/- 39.4 x 10(5) cells/100 ml BAL; P less than 0.01). The AM counts of those without pentamidine remained essentially unchanged. Lymphocytes, including CD4 and CD8 subtypes, and neutrophils did not change over time in either group. The results of this retrospective analysis suggest that, in addition to its antimicrobial action, pentamidine may modulate local lung defence mechanisms, particularly by increasing the absolute number of AM.

Administration, Inhalation

[Acute pneumocystosis during polychemotherapy following the MACOP-B protocol].

Four out of eleven patients--none of them HIV positive--who received treatment for non-Hodgkin lymphoma by the MACOP-B protocol between June 1989 and February 1990 were taken ill during or shortly after the conclusion of the course with fulminant pneumonia necessitating artificial ventilation. In three cases Pneumocystis carinii was identified as the pathogen, and in one patient the diagnosis of pneumocystosis seemed probable. The mean cumulative doses given before the outbreak of pneumonia were as follows: cyclophosphamide 2753 +/- 1161 mg, methotrexate 1590 +/- 667 mg, bleomycin 36 +/- 16.8 mg and prednisone 4378 +/- 1734 mg. The mean haemoglobin concentration was 10.7 +/- 0.5 g/dl, leucocyte count 5250 +/- 2100/microliters, lymphocyte count 1300 +/- 300/microliters and lactate dehydrogenase 227 +/- 34 U/l. The cumulative doses and laboratory findings in the seven patients not affected by pneumocytosis were not significantly different. The patients with pneumonia were supported by mechanical ventilation for 6-26 days and treated with large doses of corticosteroids and co-trimoxazole. One patient died after 17 days' ventilation. Three patients were successfully weaned from the ventilator. Chemotherapy protocols such as MACOP-B predispose to acute Pneumocystis pneumonia. The risk of infection is independent of the cumulative doses of the drugs employed. For this reason, prophylaxis with co-trimoxazole is normally mandatory.

Antineoplastic Combined Chemotherapy Protocols

Urinary excretion of mefloquine and some of its metabolites in African volunteers at steady state.

Because of the extremely long terminal elimination half-life of mefloquine it is practically impossible to measure quantitatively its urinary excretion after a single dose. Indeed, a correct estimation would require collection of urine over a period of several months. This difficulty was overcome by measuring excretion in the course of a multiple-dose study when steady-state conditions had been reached. Six male African volunteers were given at an interval of 1 week 250 mg mefloquine base in the form of its hydrochloride. Urine was quantitatively collected from each subject during the 11th week and analyzed for unchanged drug and its alcohol and acid metabolites. Excretion of the unchanged drug and of its acid metabolite amounted respectively to 9% (5.2-13.1%) and 4.2% (2.9-6.2%) of the weekly dose. Concentrations of the alcohol metabolite were too low to be measured.

Adolescent

Atypical diabetes insipidus in small cell lung cancer. Paraneoplastic syndrome or metastatic disease?

A 54-year old man was admitted with extensive disease: small cell lung cancer, and severe central diabetes insipidus. Computer assisted tomography of the brain was negative for metastatic spread to the hypothalamus or pituitary gland. Basic levels of antidiuretic hormone were within normal limits, yet the hormone failed to increase secondary to elevated osmotic load. We hypothesize that in this patient, hypothalamus and pituitary gland were morphologically intact, and that diabetes insipidus was induced by the inhibitory action of ectopic opiates on the release of antidiuretic hormone. Nevertheless, since post-mortem studies were refused, metastatic diabetes insipidus could not be definitely excluded, in which case, the source of plasmatic antidiuretic hormone would be the tumor itself.

Brain Neoplasms

Chloride-induced increase of plasma potassium after transfusion of erythrocytes in dialysis patients.

The transfusion of packed red cells (PRC), though they are depleted in cellular potassium, is thought to result in an increase of serum potassium when transfused to patients on regular hemodialysis treatment. The aim of this study was to prove this hypothesis when transfusion was performed during the dialysis-free interval. The effect of 21 transfusions of 2 units of PRC once washed with 0.9% NaCl was analyzed in 10 anemic patients. A significant increase of plasma potassium from 5.5 to 5.9 mmol/l was observed. Intracellular sodium and potassium after transfusion reflected a mixing of the patients' endogenous and the transfused red cells. However, the excess of cellular chloride introduced by the washing procedure, which was by 27.6 mmol/l higher in the transfused cells, could not be detected in the mixed cell population after transfusion. The rapid chloride shift from the transfused acid red cells into plasma, which is accompanied by a rapid uptake of bicarbonate, is thought to release an equivalent amount of potassium, most likely from muscle or bone and enhances plasma potassium. Transfusion of PRC in the dialysis-free interval seems to be no risk for patients with a plasma potassium below 5 mmol/l. Alternatives are transfusion during dialysis or addition of 20 mmol sodium bicarbonate, when transfusion is performed in the dialysis-free interval.

Adult

Multiple-dose kinetic study of mefloquine in healthy male volunteers.

250 mg mefloquine was administered orally once a week for 21 consecutive weeks to 5 volunteers. Blood samples were collected just before administration of the next dose, and the unchanged drug and its metabolite, Ro 21-5104, were measured in the plasma. The mean plasma levels minima in individual subjects measured at steady state were for mefloquine between 0.56 and 1.25 micrograms/ml, and for the metabolite between 1.47 and 5.55 micrograms/ml. The corresponding metabolite to mefloquine ratios ranged between 2.3 and 8.6. The half-life of mefloquine determined at the end of the trial agreed fairly well with values measured in single dose kinetics. This suggests that induction or inhibition of the metabolizing enzymes did not occur during the period of administration.

Adult

HLA-B27 in possible ankylosing spondylitis with peripheral arthritis.

Among 86 patients selected as possibly having ankylosing spondylitis because of clinical symptoms and radiologically normal sacroiliac joints. HLA-B27 was positive in 41%. Four years later a representative sample of 38 individuals were re-examined and radiographed. HLA-B27 positive patients developed sacroiliitis as defined by radiological criteria twice as often (P less than 0.05). They also showed increased uptake of technetium 99 m upon quantitative scintigraphy with a region of interest method and more often probable or definite ankylosing spondylitis as defined by the New York criteria. Further differences between the HLA-B27 positive and negative follow-up groups concerned the frequency of clinical symptoms and peripheral arthritis. It is suggested that HLA-B27 typing may be helpful both in diagnosis and in judging the prognosis of possible or abortive ankylosing spondylitis.

Adult

Single dose kinetics of mefloquine in man. Plasma levels of the unchanged drug and of one of its metabolites.

Oral single dose kinetics of mefloquine was investigated in 16 male volunteers, 3 Caucasians and 13 African natives. Unchanged mefloquine (= M) and one of its metabolites (= MM) were measured in the plasma. The apparent half-life of absorption of M ranged from 0.36 to 2.0 h, its terminal half-life of elimination from 15 to 33 days. Assuming complete systemic availability, an apparent volume of distribution of 14-29 liters x kg-1 and a total clearance of 18-39 ml x min-1 were derived. MM given orally to mice or rats showed at equal dose the same tolerance as mefloquine. Following oral administration of M to man, plasma levels of MM surpassed those of M, resulting in a 2.4-5.1 larger AUC. However, because of its much smaller apparent volume of distribution, MM may be anticipated to represent only a small percentage of the dose and therefore to contribute only to a minor extent towards the unwanted side effects of the drug.

Adult

Demonstration of primary cytotoxic T cells in venous blood and cerebrospinal fluid of children with mumps meningitis.

Cryopreserved lymphocytes from venous blood and cerebrospinal fluid (CSF) of 10 children with mumps meningitis were tested in 5-hr 51Cr-release assays against uninfected and mumps virus-infected PHA-blasts. Lymphocytes from all patients were cytotoxic to autologous mumps virus-infected target cells, but completely failed to lyse histoincompatible virus-infected PHA-blasts. Cytotoxicity was specific for the infecting virus, and was mediated by E rosette-forming lymphocytes. The effector cells were present over 2 to 3 wk after onset of meningitis. Mumps viral antigens appeared to be preferentially recognized in association with HLA B determinants. The results show that specifically sensitized cytotoxic T cells (CTL) are induced in patients with mumps meningitis. These cells circulate in venous blood and are locally enriched in CSF. Based on clinical observations, it is proposed that mumps-specific CTL play an immunopathologic role.

Acute Disease

Idiotype-bearing peripheral blood lymphocytes in human multiple myeloma and Waldenström's macroglobulinaemia.

Antisera raised against idiotypic determinants (ID) of myeloma proteins and macroglobulins have been used to differentiate peripheral blood lymphocyte (PBL) populations from individual patients. ID-positive lymphocytes not resembling plasma cells have been regularly found in peripheral blood in these diseases. For further characterization ID-positive lymphocytes were enriched from the peripheral blood by affinity chromatography using heterologous anti-idiotypic sera. Two patients with IgG myeloma, one patient with Waldenström's macroglobulinaemia and two persons with benign monoclonal hyperglobulinaemia (BMH) were examined by this technique. The ID-positive PBL population was shown to be heterogeneous with respect to non-tumour-specific surface markers, such as sheep erythrocytes (SRBC), Fc and C receptors. Tumour-specific idiotypic determinants will thus allow a more correct recognition of the total tumour cell compartment in these diseases.

Adult

[Prevention of pulmonary micro-embolism during blood transfusion by means of fine mesh filters (author's transl)].

Disturbances of the pulmonary micro-circulation may be due to embolic obstruction by particles in stored blood. Mechanical blocking of the lung circulation plays an important pathogenetic role in the development of progressive respiratory failure. Extraneous micro-particles can be partly eliminated from stored blood by filtration. Although a detailed clinical study of the value of microfiltration of stored bloods is still missing, the prophylactic use of fine mesh filters is advisable for all transfusions of whole blood or corpuscle concentrates regardless of the quantity to be transfused.

Blood Preservation