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Biomedical subjects

R Simon

Publications and source records attributed to R Simon.

At least 379 records · Page 21Linked to original sources
PubMed1986

[Single vessel disease of the anterior interventricular branch as a cause of combined anterior and posterior wall infarct in comparison with 2-vessel disease of the RIVA and RCA].

Only few studies deal with the problem of an isolated stenosis of the left anterior descending coronary artery (LAD) leading to a combined anterior and inferior myocardial infarction in the ECG and VCG. In the present study patients with electrocardiographic signs of anterior and inferior myocardial infarction and either one-vessel disease of the LAD branch (n = 27; group I) or two-vessel disease including the LAD and the right coronary artery (RCA) (n = 29; group II) were investigated. Due to the anterior myocardial infarction present in all patients, unequivocal signs of posterior and posterolateral infarct location were missing in the ECG and VCG. There was a distinct variability with regard to Q-wave duration and amplitude in the inferior leads of the ECG and of the Q/R-relation in the scalar lead Y of the VCG (Frank-leads) in patients with isolated LAD disease when compared to those with combined LAD and RCA disease, but no reliable parameter was found in the ECG and VCG which allowed to allocate patients to one of the two groups. On the other hand, there were significant differences in hemodynamics and left ventricular function between the two groups. Group I patients showed a significantly higher left ventricular ejection fraction (mean 49 +/- 15%) than patients with two-vessel disease (group II) (mean 42 +/- 12%) (p less than 0.05). Left ventricular end-diastolic pressures at rest (13 +/- 7 mm Hg).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Catheterization↗
PubMed1986

Therapy of autochthonous skin cancers in mice with intravenously injected liposomes containing muramyltripeptide.

Liposomes containing the immunomodulator muramyltripeptide phosphatidylethanolamine (MTP-PE) or free saline were injected i.v. into BALB/c mice with autochthonous skin cancers induced by chronic exposure to ultraviolet irradiation. Treatment with liposomes containing MTP-PE produced significant retardation in the growth of the primary autochthonous skin cancers and significantly prolonged survival of the treated mice as compared with the saline-treated controls. Since ultraviolet-irradiated mice have a defect in immunological recognition of their autochthonous tumors, the therapeutic effects of liposomes containing MTP-PE are very encouraging. These results suggest that liposomes containing MTP-PE could be used for the treatment of patients with skin cancer or other malignant diseases.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1985

Height, weight, and risk of breast cancer relapse.

The records of 231 patients with primary breast cancer and 85 patients with metastatic breast cancer were reviewed to determine whether indices of body weight were associated with prognosis. Results support previous reports that indices of body weight are relatively weak, but real, prognostic factors.

Adult↗
PubMed1985

The development of plasmid-free strains of Agrobacterium tumefaciens by using incompatibility with a Rhizobium meliloti plasmid to eliminate pAtC58.

Agrobacterium tumefaciens strains LBA275 and LBA290 were cured of their cryptic plasmid pAtC58 by the introduction of the Rhizobium meliloti plasmid pRme41a, which is incompatible with pAtC58. pRme41a and pTiC58, the resident Ti plasmid of LBA275, were subsequently eliminated by growth at supraoptimal temperature (40 degrees C). The resulting plasmid-free Agrobacterium strains, UBAPF1 and UBAPF2, have proved extremely useful for the study of Rhizobium plasmids. The loss of the cryptic plasmid pAtC58 has no effect on the tumor-forming ability of the Agrobacterium strains; when the Ti plasmid is present, normal tumors are formed on Kalanchoe daigremontiana.

DNA, Bacterial↗
PubMed1985

Development and application of the student test used in the School Health Education Evaluation.

To accurately assess the health knowledge, attitudes, and practices of students in grades four-seven, the staff of the School Health Education Evaluation (SHEE) project devoted extensive effort to identify a test appropriate for such assessment. An extensive literature review failed to produce an instrument sufficiently comprehensive or psychometrically sound that could be employed. In this paper, the philosophic orientation and the detailed processes followed in developing a noncurriculum specific, psychometrically sound evaluation instrument for use in the study is described. Included are the bases for the test framework, test objective development, test item review, the various measures constructed using the test blueprint, student performance on the test battery, the psychometric qualities of the test, and suggestions for appropriate use of the final test in other school health education settings.

Attitude to Health↗
PubMed1985

Extension of the host range of Escherichia coli vectors by incorporation of RSF1010 replication and mobilization functions.

The broad-host-range vectors pSUP104, pSUP106, pSUP204, pSUP304, and pSUP404 are based on conventional Escherichia coli vectors (such as pBR325 and pACYC184) which have been modified to include the mobilization and broad-host-range replication functions of the IncQ plasmid RSF1010. These vector plasmids now can be maintained in a wide range of bacterial genera including Rhizobium, Agrobacterium, and Pseudomonas. They are efficiently mobilized by RP4 and thus are of particular interest for bacteria refractory to transformation. They offer the selection markers and cloning sites characteristic of the basic E. coli vectors. Therefore, they can be applied and adapted to a variety of cloning strategies. However, the cloning of very large fragments (e.g., in cosmid hybrids of pSUP106) was found to affect the stability of the recombinant molecules in a Rec+ background. This instability was not observed with smaller inserts of about 5 kilobases.

Cloning, Molecular↗
PubMed1985

A reevaluation of nonhormonal cytotoxic chemotherapy in the treatment of prostatic carcinoma.

The palliative role of nonhormonal cytotoxic chemotherapy in the treatment of endocrine-resistant prostatic carcinoma has not been established. Conventional means of quantifying tumor response are most frequently not applicable in this disease because of the lack of measurable objective parameters to allow for a reliable estimation of antitumor effects. While this problem is not unique to prostatic carcinoma, this review illustrates its magnitude in this disease. Only approximately 5% of patients studied fulfill the various criteria for complete response (CR), partial response (PR), or both, while the vast majority of patients reported as responders are actually in the stable disease category. Stable disease is highly questionable as an indicator of antitumor response and should not be used as a criterion for response in conventional phase II studies unless it is convincingly demonstrated that it occurs as a result of treatment. A study design that may allow a more reliable assessment of the value of the stable disease category is described in the text. More effective means for assessing tumor responses and better instruments to measure aspects of quality of life are needed. Review of several prospective randomized clinical trials showed that no treatment program tested during the last decade resulted in a survival advantage when compared with a concurrently treated control group. Furthermore, in two such trials, four different single chemotherapeutic agents widely used in the treatment of this disease (cyclophosphamide, 5-fluorouracil, estramustine phosphate, and streptozocin) either alone or in combination, did not produce any prolongation of survival when compared to a no chemotherapy (standard treatment) control arm. Survival curves for endocrine-resistant patients fall within a relatively narrow and possibly predictable range that may be used as an additional endpoint in conjunction with response (CRs and PRs only) in phase II trials. More definitive evidence of therapeutic efficacy in this disease should derive from phase III trials using survival as one of the major endpoints. Because of the poor results observed with chemotherapy thus far, we suggest that the appropriate control arm for phase III testing in endocrine-resistant patients continues to be a no chemotherapy control arm consisting of a best symptomatic care or a uniformly applied second-line endocrine manipulation.

Antineoplastic Agents↗
PubMed1985

Prediction of survival in glioma patients by means of positron emission tomography.

The aim of this study was to determine whether positron emission tomography (PET) with fluorine-18 (18F)-2-deoxyglucose (FDG) can be used as a prognostic test in patients with high-grade cerebral gliomas, regardless of the treatment given. Forty-five patients with astrocytoma Grade III or IV were included in this analysis. The mean survival time of patients with tumors exhibiting high glucose utilization as determined by PET-FDG was 5 months, whereas patients with gliomas showing lower glucose utilization had a mean survival period of 19 months. It is postulated that PET-FDG scans reflect the biological behavior of high-grade astrocytomas and may be used to predict the survival time of patients harboring such neoplasms.

Adolescent↗
PubMed1985

Pharmacokinetic evaluation of cimetidine in newborn infants.

The pharmacokinetics of cimetidine were studied in three newborn infants with reflux esophagitis or stress ulcer. One infant was given 5 mg/kg intravenously (IV), one was given 10 mg/kg IV, and one was given 10 mg orally. Serum concentrations 30 minutes after administration were 1.2 micrograms/ml, 5 micrograms/ml, and 4.2 micrograms/ml, respectively. Concentrations greater than 0.5 micrograms/ml were measured 1, 6, and 9 hours, respectively, after administration. The half-life of the drug ranged from 1.10 to 2.18 hours. These preliminary data suggest that a dose of 5 to 7 mg/kg would effectively suppress gastric acid secretion in neonates.

Cimetidine↗
PubMed1985

Testing for qualitative interactions between treatment effects and patient subsets.

Evaluation of evidence that treatment efficacy varies substantially among different subsets of patients is an important feature of the analysis of large clinical trials. Qualitative or crossover interactions are said to occur when one treatment is superior for some subsets of patients and the alternative treatment is superior for other subsets. A non-crossover interaction arises when there is variation in the magnitude, but not in the direction, of treatment effects among subsets. Some authors use the term quantitative interaction to mean non-crossover interaction. Non-crossover interactions are usually of less clinical importance than qualitative interactions, which often have major therapeutic significance. A likelihood ratio test is developed to test for qualitative interactions. Exact critical values are determined and tabulated.

Biometry↗
PubMed1985

Randomized phase II clinical trials.

The sources of variability influencing the results of phase II trials are reviewed. Randomized designs for phase II testing are presented and evaluated. Phase II designs with "standard therapy" control groups are not found to be broadly useful. Designs which randomize among new agents or schedules appear to be of value both scientifically and logistically where patient accrual is adequate. The rationale and advantages of this design are described. The concept of ranking and selection of new agents and schedules is presented as an alternative to testing the null hypothesis of therapeutic equivalence. Sample size calculations demonstrate potential advantages of this approach in appropriate situations. The conduct of pilot or "phase II" studies of combinations is also discussed and randomized designs with early stopping rules are proposed.

Antineoplastic Agents↗
PubMed1984

Improved detection of focal lesions with computerized tomographic examination of the liver using ethiodized oil emulsion (EOE-13) liver contrast.

A prospective study of computerized tomography (CT) of the liver using a liver contrast agent compared to conventional CT was undertaken. CT scanning without contrast agents (NC-CT), CT with water-soluble contrast (WSC-CT), and CT with ethiodized oil emulsion (EOE-CT) were performed on patients with possible or probable hepatic metastases. The findings on these three examinations were compared to the objective findings at surgery in 53 patients. Accuracy of these examinations was 80.7% for NC-CT, 77.1% for WSC-CT, and 84.9% for EOE-CT. The true-positive percentage for 129 hepatic lesions was 40.6% for the NC-CT, 33.6% for WSC-CT, and 76.7% for the EOE-CT. Eighty-three percent (44/53) of 1- to 2-cm liver lesions were detected by EOE-CT, whereas only 26.4% (14/53) lesions of this size were detected by the NC-CT and 20.4% (10/49) shown by WSC-CT. The likelihood that a lesion seen by CT scan was malignant was 84.6% for NC-CT, 89.4% for WSC-CT, and 81.8% for EOE-CT. The EOE contrast agent improves the sensitivity of liver CT for detecting hepatic metastases. The improvement occurs with lesions 1 cm and greater in diameter, but is particularly striking for lesions of 1 to 2 cm in diameter.

Ethiodized Oil↗
PubMed1984

High frequency mobilization of gram-negative bacterial replicons by the in vitro constructed Tn5-Mob transposon.

A DNA fragment of the broad host range plasmid RP4 carrying the cis-acting DNA recognition site for conjugative DNA transfer between bacterial cells (Mobsite) was cloned into the kanamycin-neomycin resistance transposon Tn5. Using conventional transposon mutagenesis techniques the new transposon, called Tn5-Mob, can easily be inserted into the host DNA of gram-negative bacteria. A host replicon carrying Tn5-Mob is then mobilizable into any other gram-negative species if the transfer functions of plasmid RP4 are provided in trans. The potential of Tn5-Mob was demonstrated by mobilizing Rhizobium meliloti plasmids as well as the E. coli chromosome at high frequencies.

Chromosomes, Bacterial↗