Search PubMed⌕ Search

Biomedical subjects

S Simon

Publications and source records attributed to S Simon.

At least 19 recordsLinked to original sources
PubMed1995

Computer-assisted morphonuclear characterization of radiotherapy-induced effects in MXT mouse mammary adenocarcinomas surviving earlier radiotherapy.

PURPOSE: To present the effects of different radiotherapeutic treatments on the morphonuclear characteristics and growth of the MXT mouse mammary adenocarcinoma. METHODS AND MATERIALS: We collected MXT tumor cells by means of fine-needle aspirations during various radiotherapeutic treatments and analyzed the morphological aspects of the cell nuclei by means of the digital cell image analysis of Feulgen-stained nuclei. In addition, we studied the morphonuclear aspects of cells from MXT tumors that had been radioresistant cell enriched. These radioresistant cell-enriched tumors involved MXT tumors that had survived one or two previous radiotherapies. The radiotherapy-induced effects on the morphonuclear characteristics were monitored by means of both monovariate (one-way variance) and multivariate (principal components and step-wise linear discriminant) analyses. RESULTS: The monovariate analyses showed that radiotherapy significantly influenced the values of the parameters relating to nuclear size (nuclear area--NA), the frequency of small dense chromatin clumps (short run length emphasis--SRL) in the nuclei, and the overall chromatin condensation level (local mean--LM). The global effect corresponded to a decrease in the overall chromatin condensation level in the radioresistant cell-enriched MXT tumors. This decrease occurred concomitantly with an increase in the frequency of the small dense chromatin clumps in the nuclei and a decrease in the nuclear area. The multivariate analyses showed that it was possible to quantitate the proportion of "radiosensitive-like" and "radioresistant-like" cell nuclei in the various MXT tumor types under study. CONCLUSIONS: The development of certain morphonuclear parameters, that is, the NA, the SRL, and the LM, could be proposed to predict the response of human tumors to radiotherapy as, indeed, could the quantitation of the proportion of radioresistant cells.

Adenocarcinoma↗
PubMed1995

Hepatitis C virus RNA detection and HCV genotype in patients with chronic non-A, non-B hepatitis in Jakarta.

Antibody response in HCV infection may be variable and the variability of the serological response could be due to the differences in HCV strains. Since the distribution of hepatitis C virus genotype has been found to be geographically dependent, it is important to determine the distribution of HCV genotype in various countries with high prevalence of chronic non-A, non-B hepatitis. In this study, serum HCV RNA was examined in 53 patients suspected of chronic non-A, non-B hepatitis with an anti-HCV test as determined by currently available assay. HCV viremia was detected in 48 patients (90.6%). These patients had elevated serum ALT level at the time of HCV RNA determination. Using specific genotype probes, all isolates were classified into three different genotypes. Double and triple infections were also noted. HCV genotype 1b is the predominant genotype found in chronic hepatitis C patients in Jakarta.

Adult↗
PubMed1995

Tracheal aspirates in long-term mechanically ventilated patients. A human model of gram-negative infection and airway inflammation.

It is well known that patients requiring long-term mechanical ventilation and tracheostomy have nearly universal airway colonization with Gram-negative organisms. However, useful parameters to objectively describe the airway inflammation associated with airway instrumentation and colonization have not been well define. In our respiratory care unit, patients who are medically stable except for ventilator dependence are readily available for longitudinal assessment of airway secretions and therefore provide a unique population for studying airway inflammation and infection. To quantitate production of respiratory secretions, we instituted a uniform protocol of suctioning over a 6-h period. Further, we devised a method of dilution and homogenization of tracheal aspirates that permits reproducible intrasample total cell counts (coefficient of variation, 4.6%). With these techniques, patients were then studied serially over a 4- to 7-week period. Total cell count, inflammatory cell differential, and two indices of airway inflammation, human neutrophil elastase (HLE) and soluble-intercellular adhesion molecule-1 (sICAM-1) studied in the sol phase of secretions were monitored. The mean total cell count was 42.2 x 10(6) cells per gram of secretions when patients were clinically stable and not receiving antibiotics. The average differential was neutrophils 69.9%, macrophages 26.9%, and lymphocytes 2.8%. Mean active HLE was 35.6 micrograms/mL and mean sICAM-1 was 83 ng/mL. Six patients during the period of observation received intravenous oral or aerosolized antibiotics for tracheobronchitis. A threefold drop in volume of secretions was measured (p < 0.018). The total cell count and percent neutrophils decreased from 76.4 x 10(6)/g of sputum to 54.9 x 10(6) and 72.2 to 54.9%, respectively. While these changes were not statistically significant, the absolute number of airway neutrophils over the 6 h decreased sevenfold (p < 0.014). Similarly sICAM-1 burden (micrograms per 6-h period) also decreased significantly (p < 0.034). These patients provide a unique human model for future studies specifically designed to assess the effect of novel modalities of anti-inflammatory and antimicrobial agents on respiratory secretions.

Adult↗
PubMed1994

Antibodies specific for the neuronal form of the Src protein elicited by an antigenized antibody.

To elicit antibodies directed specifically against the neuron-specific form of the c-src gene product, pp60c-src(+), we used an antigenized antibody comprising a decamer containing the amino acid sequence specific to pp60c-src(+) inserted into the third hypervariable loop of the heavy (H)-chain variable (V)-region. This was used to raise anti-idiotype antibodies reacting with the peptide epitope in rabbits. The antisera reacted with pp60c-src(+), as judged by immune blotting, immunoprecipitation, immune complex kinase assay, and indirect immunofluorescence staining, but did not react with the fibroblast form of the c-src gene product, pp60c-src. Antigenized antibody is a useful approach for producing antibodies able to distinguish between isoforms of the same gene product and specific for the neuronal form of the Src protein.

3T3 Cells↗
PubMed1993

Interactions of lipopolysaccharide with neutrophils in blood via CD14.

The functional characteristics of neutrophils are exceedingly sensitive to physiological conditions as well as the details of isolation. Exposure to lipopolysaccharide (LPS) or even contamination of the isolating media with traces of LPS is known to play an important role in regulating cell function and expression of receptors. Because of the suspected role of CD14 as a receptor for LPS, we used anti-CD14 monoclonal antibodies both to identify CD14 in the cell surface of polymorphonuclear leukocytes and to inhibit functional changes elicited by LPS. Cytometric techniques were used to investigate the regulation of CD14 and CR3 on the neutrophil cell surface in whole blood to minimize any effects of isolation. In whole blood neutrophil express low levels of formyl peptide receptor, CD14, and CR3, which increase substantially in response to formyl peptide and LPS. The increases in CR3 and CD14 occurred in parallel and were independent of protein synthesis and tumor necrosis factor (TNF) production. The increase in CR3 was inhibited by antibodies MY4, 3C10, and 28C5 against CD14. These findings are consistent with the notion that in blood the observed receptor up-regulation is in direct response to the action of LPS on neutrophils through CD14 and does not require products from macrophages such as TNF or the production of C5a from the plasma.

Antibodies, Monoclonal↗
PubMed1993

A constitutively expressed serum amyloid A protein gene (SAA4) is closely linked to, and shares structural similarities with, an acute-phase serum amyloid A protein gene (SAA2).

The acute-phase reactant serum amyloid A (SAA) is a polymorphic apolipoprotein encoded by a family of highly homologous and closely linked genes: SAA1, SAA2, and SAA3. We have isolated a human genomic cosmid clone containing the gene encoding a fourth, constitutively expressed member of the human SAA superfamily, C-SAA, together with an SAA2*2 (SAA2 beta) gene. The gene encoding C-SAA shares the same 5' to 3' orientation as SAA2*2 and has the characteristic four-exon structure of the other members of the SAA superfamily. The exons of the gene encoding C-SAA share only limited sequence identity with those of SAA1, SAA2, and SAA3; they specify an mRNA, represented by the CS-1 cDNA reported previously by us, which is expressed at low levels (relative to the acute-phase SAAs) in normal and acute-phase liver. The gene encoding C-SAA is located 9 kb downstream of SAA2*2 and therefore occupies the locus that has been identified as containing the SAA4 gene.

Acute-Phase Proteins↗
PubMed1992

[Kinetics of thermal killing of microorganisms in egg yolk].

Egg yolk is relating to its germ content and enzyme activity only restricted storable. Unpasteurized egg yolk get spoiled between a few hours and days. The rapid spoilage can be reduced by a pasteurization and following cold storage. The storage stability of egg yolk can be increased by additives, e.g. salt or saccharose. Kinetic results of the thermal microorganisms destruction in the egg yolk with and without stabilizing additives are presented in this article. It will be shown that the evaluation method from REICHART gives representative results for mixed cultures, too. A further evaluation method by a differential equation will be demonstrated and discussed.

Bacteria↗
PubMed1992

The prognostic value of the pathological response to combination chemotherapy before cystectomy in patients with invasive bladder cancer. European Organization for Research on Treatment of Cancer--Genitourinary Group.

The prognostic value of the pathological response to combination chemotherapy of deeply invasive transitional cell cancer of the bladder was retrospectively assessed in 147 patients. Data were collected from 8 different centers. Patients were eligible if they had received intravenous combination chemotherapy followed by partial, total or radical cystectomy, and if they had a minimum followup of 2 years after the start of chemotherapy. Of the patients 90% received methotrexate, vinblastine, doxorubicin and cisplatin (M-VAC) or cisplatin plus methotrexate for a median of 3 courses (range 1 to 6). Of the 83 patients who were alive at analysis actuarial median followup was 30.5 months (range 13.2 to 85.6 months). A major pathological response (stage P0, Pis, Pa or P1) was achieved in 41.5% of the patients. Patients with a major pathological response (p stage less than 2) had a 5-year survival of 75% in contrast to 20% for the remaining nonresponding patients (p stage 2 or more). The survival of patients with a major pathological response was independent of whether the response was induced by 2 or more courses of chemotherapy, or whether it was induced by M-VAC in comparison with cisplatin plus methotrexate. Preoperative clinical assessments can identify nonresponding patients correctly and in these cases alternative treatment programs are required, since 80% will die of the disease. Moreover, if neoadjuvant chemotherapy is proved to increase survival, the data emphasize the importance of the response rate of the primary tumor and the need to investigate the optimal number of courses to induce the best response, preferably in the individual patient.

Actuarial Analysis↗
PubMed1992

[Techniques and experiences in funnel chest operations].

Hegemann's technique of funnel chest correction using transsternal metal bar stabilization was adapted from the method published by Sulamaa and coworkers in 1958. Until the end of 1991, about 2400 chest wall corrections were performed in our department, more than 2000 of them using modifications of the original method. The principles of external chest wall measurement, our classification method, and the current operative modifications are described. In long-term follow-up examinations less than 3% recurrences should be possible.

Adolescent↗
PubMed1991

A restriction fragment of the C2 gene is a unique marker for C2 deficiency and the uncommon C2 allele C2*B (a marker for type 1 diabetes).

There are three common C2 protein alleles in caucasians, C2*C, C2*B, and C2*Q0, with allele frequencies of 0.96, 0.03, and 0.01, as well as Sst I RFLP variants of 2.75, 2.7, 2.65, 2.55, and 2.4 kb, with frequencies of 0.017, 0.533, 0.358, 0.017, and 0.075. Thus, C2*C is informatively split by the RFLP. Of 94 nonrandomly ascertained caucasian complotypes, 77 contained C2*C, four contained C2*Q0, and 13 had C2*B. None of the C2*C-containing complotypes carried the 2.75 kb Sst I fragment and all of the complotypes with C2*B or C2*Q0 carried it. All of the C2*Q0 alleles were associated with C4A*4, C4B*2 in the complotype S042 as previously reported. C2*B was usually (9/13) in the complotype SB42, occasionally (1/13 each) in SB45, SB41, SB(4,3)0, and SB31. Thus, the association of the C2 2.75-kb fragment was with C2*B and C2*Q0, not with C4A*4, C4B*2, or even C4A*4 alone. The complotype SC42 was associated with the 2.65-kb Sst I fragment in four of five instances and in a single example with the 2.7-kb fragment. C2*B and C2*Q0 possibly had a common evolutionary ancestor complotype which carried the 2.75-kb Sst I fragment, and BF*S, C4A*4, and C4B*2. C2*B (particularly as the haplotype HLA-Bw62, SB42, DR4) is associated with type 1 diabetes but C2*Q0 is protective.

Alleles↗
PubMed1991

A survey of the nutritional adequacy of meals served and eaten by patients.

The survey was carried out at one hospital to evaluate the nutrient content of the food served to and consumed by eight female patients. A weighed food intake was undertaken on the subjects chosen, over three days. Observations were also recorded regarding the nursing and catering practices relating to meals. The results showed that the food served to this group of patients was deficient in energy, folic acid, iron and vitamin D and that this group of patients failed to achieve an adequate vitamin C, protein, calcium and fibre intake. Problems also existed with the ordering and service procedure for meals, timing of meals, quantities of food delivered to the ward and procedure of patients who are eating poorly. Although the numbers in the survey were too small for statistical analysis, it was felt that the results were as representative as possible. This survey was felt to be very worthwhile and highlighted the need for all members of staff involved in the care of these patients to work together to consider ways that the patients' food intake could be improved in the future. The study, carried out by a dietitian is particularly relevant to the work of nurses in this field, as they are often the key persons affecting the patient's choice and consumption of food.

Female↗
PubMed1990

The p53 tumour suppressor protein is phosphorylated at serine 389 by casein kinase II.

The entire coding sequence of wild-type mouse p53 was expressed in Escherichia coli under control of the PL promoter of bacteriophage lambda. The bacterial p53 protein had identical mobility to p53 from SV3T3 cells on SDS polyacrylamide gels and was recognized in bacterial lysates by three p53-specific monoclonal antibodies, including PAb246 which is specific for wild-type mouse p53. Immunoprecipitates of the bacterial p53 were phosphorylated by a highly purified preparation of rat casein kinase II; the stoichiometry of incorporation was approximately 1 mol of phosphate per mol of p53. The phosphorylated residue was identified by phosphopeptide mapping as serine 389, which is a major site of p53 phosphorylation in vivo. p53 (serine 389) kinase activity was detected on lysates of SV3T3 cells; this activity co-purified with casein kinase II on phosphocellulose and Mono Q columns and was inhibited by heparin. Immunoprecipitates of the p53-T antigen complex from SV3T3 cells also had associated serine 389 kinase activity. Phosphorylation of serine 389 by this kinase was potently inhibited by heparin and quenched by excess unlabelled GTP. The data indicate that p53 is a physiological substrate of casein kinase II, which is stimulated in response to mitogens, phosphorylates nuclear oncoproteins, and may play a role in the transduction of extracellular signals to the nucleus.

Amino Acid Sequence↗
PubMed1989

The effect on gait of lengthening of the medial hamstrings in cerebral palsy.

The purpose of this study was to analyze the effect of lengthening of the medial hamstrings on the gait of patients who had spastic cerebral palsy. Thirty-one patients had preoperative and postoperative gait analyses. Standard parameters, such as velocity, cadence, and stride length, were evaluated, as were motion graphs of the hip, knee, and ankle. There was little difference between the preoperative and postoperative mean values for velocity, cadence, and stride length, which were expressed as percentages of normal for the patient's age. The contours of the postoperative motion graphs of the knees changed very little compared with those of the preoperative graphs; when a graph showed restricted motion preoperatively, it did so postoperatively. Although extension of the knee in stance phase improved postoperatively, the improvement was accompanied by decreased flexion of the knee during swing phase. When spasticity of both the hamstrings and the quadriceps was noted on the preoperative electromyogram, motion of the knee in the sagittal plane was markedly restricted.

Adolescent↗