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Biomedical subjects

J Simon

Publications and source records attributed to J Simon.

At least 145 records · Page 8Linked to original sources
PubMed1999

Ileal neobladder and local recurrence of bladder cancer: patterns of failure and impact on function in men.

PURPOSE: Creation of an ileal neobladder has become a standard procedure in patients undergoing cystectomy for invasive bladder cancer. We evaluated the impact of local recurrence on ileal neobladder function and survival. MATERIALS AND METHODS: Between April 1986 and February 1997, 357 men underwent radical cystectomy and ileal neobladder substitution at our institution. We retrospectively reviewed the records of these patients to determine patterns of local recurrence and survival rates. RESULTS: Local recurrence developed in 43 of the 357 patients (12%), in whom median survival plus or minus standard deviation was 17 +/- 1.6 months and median time to recurrence was 10 months (range 2 to 41). Of the 43 patients with local recurrence at followup 36 had local advanced cancer on the final pathological evaluation (stage pT3a or node positive, or greater). A total of 17 patients (43%) had concomitant distant metastasis. Of the 43 patients 3 are alive at 36, 48 and 147 months, respectively. Death was due to disease in 36 cases, chemotherapy related complications in 3 and another cause in 1. Of the 43 patients 40 maintained good neobladder function. Local recurrence interfered with the upper urinary tract in 24 cases, neobladder in 10 and intestinal tract in 7. The neobladder was removed only in 1 patient due to a neovesical intestinal fistula. CONCLUSIONS: The local recurrence rate after orthotopic urinary reconstruction is 12%. Survival after local recurrence is diagnosed is limited despite multimodality therapy. However, most patients may anticipate normal neobladder function even in the presence of recurrent disease or until death. Thus, creating orthotopic diversion after cystectomy in patients with locally advanced bladder cancer, including macroscopically or microscopically positive lymph nodes, is safe.

Adult↗
PubMed1999

Genetic models for the study of insulin-like growth factors (IGF) and muscle development in birds compared to mammals.

IGFs are important positive modulators of overall body and muscle growth in different species. Genetic variation in IGF-I gene expression exists as shown by the possibility of genetic selection for high or low circulating IGF-I concentrations in mice and the associated variations in growth potential. Targeted over-expression of IGF-I in transgenic mice results in muscle hypertrophy, but it is yet unknown whether genetic variability in muscle IGF-I gene expression exists. Much less data are available in birds. This review is focussed on the potential role of IGFs on chicken muscle development. Apart from the absence of a type 2 IGF receptor (IGF-II receptor), the general characteristics of the chicken IGF system seem to be similar to mammalian species. In different genetic models with altered growth rates or body composition, differences in the IGF system are observed suggesting its importance in regulating body growth in those species. The components for a paracrine action of IGF are also present in chicken muscle but it has not yet been demonstrated if they contribute to differences in muscle development.

Animals↗
PubMed1999

A novel member of murine Polycomb-group proteins, Sex comb on midleg homolog protein, is highly conserved, and interacts with RAE28/mph1 in vitro.

The Polycomb group of (PcG) genes were originally described in Drosophila, but many PcG genes have mammalian homologs. Genetic studies in flies and mice show that mutations in PcG genes cause posterior transformations caused by failure to maintain repression of homeotic loci, suggesting that PcG proteins have conserved functions. The Drosophila gene Sex comb on midleg (Scm) encodes an unusual PcG protein that shares motifs with the PcG protein polyhomeotic, and with a Drosophila tumor suppressor, lethal(3)malignant brain tumor (l(3)mbt). Expressed sequence tag (EST) databases were searched to recover putative mammalian Scm homologs, which were used to screen murine cDNA libraries. The recovered cDNA encodes two mbt repeats and the SPM domain that characterize Scm, but lacks the cysteine clusters and the serine/threonine-rich region found at the amino terminus of Scm. Accordingly, we have named the gene Sex comb on midleg homolog 1 (Scmh1). Like their Drosophila counterparts, Scmh1 and the mammalian polyhomeotic homolog RAE28/mph1 interact in vitro via their SPM domains. We analyzed the expression of Scmh1 and rae28/mph1 using northern analysis of embryos and adult tissues, and in situ hybridization to embryos. The expression of Scmh1 and rae28/mph1 is well correlated in most tissues of embryos. However, in adults, Scmh1 expression was detected in most tissues, whereas mph1/rae28 expression was restricted to the gonads. Scmh1 is strongly induced by retinoic acid in F9 and P19 embryonal carcinoma cells. Scmh1 maps to 4D1-D2.1 in mice. These data suggest that Scmh1 will have an important role in regulation of homeotic genes in embryogenesis and that the interaction with RAE28/mph1 is important in vivo.

Amino Acid Sequence↗
PubMed1999

The single cysteine residue of the Sud protein is required for its function as a polysulfide-sulfur transferase in Wolinella succinogenes.

The periplasmic Sud protein which is induced in Wolinella succinogenes growing by polysulfide respiration, has been previously proposed to serve as a polysulfide binding protein and to transfer polysulfide-sulfur to the active site of polysulfide reductase [Klimmek, O, Kreis, V., Klein, C., Simon, J., Wittershagen, A. & Kröger, A. (1998) Eur. J. Biochem. 253, 263-269.]. The results presented in this communication suggest that polysulfide-sulfur is covalently bound to the single cysteine residue (Cys109) of the Sud monomer, and that Cys109 is required for tight binding of polysulfide-sulfur and for sulfur transfer. A modified Sud protein [(C109S)Sud-His6] in which the cysteine residue was replaced by serine, did not catalyze sulfur transfer from polysulfide to cyanide and did not stimulate electron transport to polysulfide, in contrast to Sud-His6. The polysulfide-sulfur bound to (C109S)Sud-His6 was fully removed upon dialysis against sulfide. After this treatment, Sud-His6 retained one sulfur atom per monomer; thiocyanate was formed upon addition of cyanide to the preparation. After incubation of Sud-His6 with polysulfide, a proportion of the Sud-His6 monomers carried one or two sulfur atoms, as shown by matrix-assisted laser desorption ionization mass spectrometry. The sulfur atoms were absent from monomers derived from Sud-His6 treated with cyanide and from (C109S)Sud-His6 incubated with polysulfide.

Amino Acid Substitution↗
PubMed1999

Circulating insulin-like growth factors (IGF-I and -II) and IGF binding proteins in divergently selected fat or lean chickens: effect of prolonged fasting.

Possible differences in insulin-like growth factors (IGF-I and -II) and their binding proteins (IGFBPs) were investigated in genetically fat or lean chickens. Comparisons were performed at 9 weeks of age in the fed or the fasted (48 h) state. Plasma concentrations of both IGFs were altered by nutrition and genotype. IGF-I, and to a lower extent IGF-II, decreased following fasting. IGF-I and -II were higher in fat compared to lean chickens, in both the fasted and the fed states. Of four circulating IGFBPs with molecular weights of 28, 34, 40 and 60 kDa, IGFBP-28, and to a lesser extent IGFBP-34 and -60, increased in the fasted state. No consistent differences were observed between genotypes for IGFBPs. Therefore in chickens, as in mammals, IGFs are downregulated, and IGFBP-28 upregulated by fasting. An increase in IGFs levels in Fat chickens may contribute to enhance fat deposition in this genotype.

Adipose Tissue↗
PubMed1999

Metabolic differences between genetically lean and fat chickens are partly attributed to the alteration of insulin signaling in liver.

Insulin signaling [tyrosine phosphorylation of insulin receptor (IR), insulin receptor substrate-1 (IRS-1), Src homology and collagen protein (Shc) and phosphatidyl inositol 3'-kinase activity (PI 3'-kinase)] was studied in the liver and thigh muscles of fat (FL) and lean (LL) chickens. These lines result from a divergent selection on abdominal fat pad size. The divergence is of metabolic origin. Extreme nutritional states were studied (fed, 48-h starved and 30-min refed). Such conditions significantly altered insulin signaling in chicken liver, but surprisingly not in the muscle (except the phosphorylation of Shc in the refed state). No major differences that could account for this divergence were found in muscle. Liver IR number and Shc protein did not differ between genotypes. Liver IRS-1 (protein and messenger) was lower in the fed state and higher in the starved state in FL compared to that in LL chickens. In the fed state, tyrosine phosphorylation of liver IR, IRS-1 and Shc action was higher in FL than in LL chickens that in the absence of insulin resistance rely on higher plasma insulin levels. In the starved state, phosphorylation of liver IR was lower, but the phosphorylation of IR and IRS-1 were higher in LL than in FL chickens, most likely in response to higher plasma glucose and insulin in the lean genotype. In the refed state, the phosphorylation of liver IR and IRS-1 did not differ between genotypes despite significantly lower plasma insulin in FL chickens. Finally, PI 3'-kinase was not affected by the genotype. A significant activation of early steps of insulin signaling in liver of fed FL chickens may at least partly account for their increased liver lipogenesis and ultimately their fattening.

Animals↗
PubMed1999

Effects of Mahonia aquifolium ointment on the expression of adhesion, proliferation, and activation markers in the skin of patients with psoriasis.

OBJECTIVE: To examine the effects of topical therapy with Mahonia aquifolium on the expression of pathogenetically relevant molecules in psoriatic skin by immunohistochemistry. STUDY DESIGN: Prospective-randomized, half-side comparison study with subsequent immunohistochemical assessment of biopsies. METHODS: The study areas were treated with Mahonia aquifolium ointment 3( daily and with dithranol in rising concentrations 1( daily, respectively. Biopsies of lesional skin from the test areas were carried out in 49 patients a) prior to therapy and b) 4 weeks after the start of therapy. Immunohistochemical stainings were performed with the following monoclonal antibodies: anti-ICAM-1, -CD3, -HLA-DR, -keratin 6, -keratin 16, -Ki-67. Evaluation of staining was made by two independent examiners using established semiquantitative scores. RESULTS: Marked staining with all of the cited monoclonal antibodies was observed in the lesional skin prior to therapy. After 4 weeks of therapy there was a marked reduction in the expressions of ICAM-1, CD 3, HLA-DR and keratin 6 and 16. There were significantly greater reductions of ICAM-1, CD3, and HLA-DR at sites treated with dithranol. The expression of Ki-67 was not reduced by either therapy. CONCLUSIONS: These results indicate efficacy of Mahonia aquifolium and dithranol in psoriatic skin both on cellular cutaneous immune mechanisms and on the hyperproliferation of keratinocytes. The effect of dithranol appears to be more potent than that of Mahonia aquifolium.

Administration, Topical↗
PubMed1999

Dual phase helical CT of a primary malignant fibrous histiocytoma of the right renal vein.

A case is reported of primary malignant fibrous histiocytoma of the right renal vein involving the ipsilateral kidney which showed early enhancement on dual phase helical CT. The correct diagnosis of a primary tumour of the renal vein involving the kidney was not made but in retrospect could have been achieved pre-operatively by considering several CT features.

Histiocytoma, Benign Fibrous↗
PubMed1999

Corticosterone alters insulin signaling in chicken muscle and liver at different steps.

Chronic treatment with corticosterone evokes insulin resistance in chickens, a species which is already resistant to insulin compared with mammals. The in vivo effects of corticosterone on insulin signaling were investigated in chicken liver and thigh muscle in two nutritional states: basal (overnight fasted) and stimulated (30 min refeeding). Corticosterone significantly decreased specific insulin binding in liver and the amount of insulin receptor substrate-1 (IRS-1) and p85 (regulatory subunit of phosphatidylinositol (PI) 3'-kinase) in both tissues. Insulin receptor (IR) and IRS-1 mRNAs generally varied accordingly. Src homology and collagen protein (Shc) and messenger were not altered. In liver, in the basal state, the tyrosine phosphorylation of IR, IRS-1 and Shc, and the IR-associated PI 3'-kinase activity were largely decreased by corticosterone. Following refeeding the cascade was activated in control but totally inhibited in treated chickens. In muscle, as previously observed, IR and IRS-1 phosphorylation and PI 3'-kinase were not stimulated by refeeding in controls. Only the phosphorylation of Shc was increased. On this background, corticosterone decreased the basal PI 3'-kinase activity and prevented the phosphorylation of Shc in response to refeeding. In conclusion, corticosterone largely impaired insulin signaling in liver and to some extent in muscle. This should contribute to the large impairment of growth. In addition, the present studies further emphasize the peculiarities of insulin signaling in chicken muscle, which needs further investigation.

Animals↗
PubMed1999

Correlation and prognostic significance of p53, p21WAF1/CIP1 and Ki-67 expression in patients with superficial bladder tumors treated with bacillus Calmette-Guerin intravesical therapy.

PURPOSE: We determine if, before intravesical bacillus-Calmette Guerin (BCG) therapy, p53, p21WAF-1-CIP1 (a critical downstream effector of p53 pathway of cell growth control, inhibiting cyclin dependent kinases) and the cell proliferation marker Ki-67 (MIB-1) could be used as prognostic markers of response to BCG in patients with superficial bladder tumors. MATERIALS AND METHODS: The study included 47 patients with superficial bladder tumors at high risk for recurrence or progression treated with 6 weekly intravesical BCG instillations. We analyzed p53, p21 and Ki-67 on paraffin embedded samples by immunohistochemistry and the percentage of positive cells was determined in a blinded fashion. Quantitative immunostaining was analyzed in relation to time to recurrence and progression using univariate or multivariate analysis and the Kaplan-Meier method. RESULTS: During a mean followup of 24.6 months 23 of the 47 patients (48.9%) presented with tumor recurrence and 10 (21.2%) had later progression to invasive disease. A p21 over expression (greater than 10%) was observed in 23 tumors (48.9%) and positively correlated with p53 (p = 0.0097) but not with Ki-67 (p = 0.327). Of the tumors 18 (38.2%) were p53 and p21 negative. Among p21 positive tumors 15 (65.2%) were p53 and p21 positive, suggesting that p21 may also be regulated by p53 independent pathways. However, p53 did not act as a predictor of recurrence or progression. In contrast, using Kaplan-Meier curves p21 over expression (greater than 10%) and Ki-67 at a 25% cutoff were associated with shorter recurrence-free survival (both p = 0.02 log rank test) but they did not predict additional information about risk of progression. However, multivariate analysis failed to demonstrate any independent prognostic value for p21 or Ki-67 in contrast to tumor stage. CONCLUSIONS: Our results indicate that p21WAF-1-CIP1 seems to be regulated by p53 independent pathways in superficial bladder cancer. The present study did not indicate an independent prognostic significance in patients treated with BCG for p53, p21WAF-1-CIP1 or Ki-67 markers. Larger prospective studies are needed to evaluate further the independent value of these biological markers in superficial bladder cancer management.

Adjuvants, Immunologic↗
PubMed1999

Differential effects of estrogen-androgen and estrogen-only therapy on vasomotor symptoms, gonadotropin secretion, and endogenous androgen bioavailability in postmenopausal women.

OBJECTIVE: To investigate somatic symptom relief, gonadotropin secretion, and endogenous androgen bioavailability (protein-bound and free) during 3 months of estrogen-androgen therapy or matched estrogen-only replacement therapy. DESIGN: Ninety-three naturally menopausal outpatients with 6 or more months of amenorrhea, who were experiencing mild-to-moderate vasomotor symptoms, were randomized to receive one of five treatments: oral esterified estrogens (0.625 mg or 1.25 mg), oral esterified estrogens combined with methyltestosterone (0.625 mg combined with 1.25 mg methyltestosterone or esterified estrogens 1.25 mg combined with 2.5 mg methyltestosterone), or placebo for 12 weeks. All treatments were preceded by a 4-week placebo lead-in period. RESULTS: Patients receiving the lower dose of estrogen-androgen therapy had fewer somatic menopausal symptoms than patients receiving the lower dose estrogen (0.625 mg), and they experienced somatic symptom relief similar to those patients receiving the higher dose of estrogen (1.25 mg). Significantly greater luteinizing hormone suppression (p < or = 0.03) occurred in estrogen-androgen groups compared to estrogen groups, suggesting that added androgen might mediate a more pronounced negative feedback on the hypothalamic-pituitary axis. Sex hormone-binding globulin increased significantly in both estrogen-treated groups (p < or = 0.01), whereas decreases occurred in both estrogen-androgen groups (p < or = 0.006). The higher dose estrogen-only preparation significantly reduced androstenedione (p < or = 0.01) and dehydroepiandrosterone sulfate (p < or = 0.005). CONCLUSION: The extent of relief with lower dose estrogen-androgen therapy was similar to higher dose estrogen-only treatment. The greater efficacy of combination therapy on somatic symptoms could be mediated by the same mechanism responsible for the suppressive effects of estrogen-androgen therapy on luteinizing hormone secretion. The marked differences in circulating levels of sex hormone building globulin, which were increased by estrogen and decreased by estrogen-androgen, and the resulting impact on bioavailable androgens and estrogens could also explain the differential somatic relief with both treatments. Endogenous adrenal androgens were lower in women treated with esterified estrogens 1.25 mg/day, suggesting that estrogen therapy can produce a significant hypoandrogenic state by inhibiting production or accelerating clearance of adrenal androgens.

Administration, Oral↗
PubMed1999

Progress in characterization of pre-implantation factor in embryo cultures and in vivo.

PROBLEM: Pre-implantation factor (PIF), a small, embryo-derived peptide is detected in the maternal serum prior to implantation and is associated with successful pregnancy outcome. However, its identity is not known. METHOD OF STUDY: PIF was isolated from mouse embryo conditioned media and from pregnant porcine sera, using high-performance liquid chromatography (HPLC) followed by mass spectrometry. RESULTS: Conditioned culture media was separated by gel filtration chromatography followed by reversed phase chromatography. At each step, PIF activity was determined by the lymphocyte/platelet binding autorosette assay (LPBA). Mass spectrometry yielded a single peak with a mass of 1300 Da. The peptide is, however, present in very low concentrations (fM), which has so far precluded complete identification. Pregnant porcine sera that exhibit potent PIF activity were deproteinated by acetone and further fractionated by reversed phase HPLC. Active fractions contain peptides of molecular masses 523 and 551 Da. CONCLUSION: PIF, likely to be peptides, represents a novel substance related to pregnancy initiation and maintenance.

Animals↗
PubMed1999

The role of morphine-augmented cholescintigraphy and real-time ultrasound in detecting gallbladder disease.

OBJECTIVE: Rapid diagnosis of acute cholecystitis is essential to minimize morbidity and mortality. The purpose of this study was to assess the diagnostic utility of cholescintigraphy using morphine augmentation compared with ultrasound, in acute and chronic gallbladder disease. METHODS: Cholescintigrams were performed on 103 patients suspected of having acute cholecystitis. In 79 patients (Group A) morphine sulfate was administered to reduce the scintigraphic imaging time if the gallbladder was not visualized during the first hour. In 24 control patients (Group B) no morphine was administered. All patients were evaluated clinically and 93 patients had concurrent ultrasound examination. RESULTS: The clinical presentation was nonspecific. The ultrasound findings were sensitive in detecting gallbladder disease (100%), but had low specificity (24%). Only findings of sediments and pericholecystic fluid were specific for cystic duct obstruction. Morphine augmentation reduced the imaging time by 126 min in patients with chronic cholecystitis. CONCLUSION: Real-time ultrasound has low specificity for gallbladder disease. In the presence of an abnormal ultrasound, it is essential to perform a hepatobiliary scan, either to exclude gallbladder disease or distinguish acute from chronic cholecystitis. Low-dose morphine administration is a safe and useful adjunct to standard cholescintigraphy by substantially reducing the time required to obtain a diagnostic study.

Acute Disease↗
PubMed1999

Gauze swabs left intrapericardially following cardiac surgery.

The occurrence of surgical gauze swabs left in the body following operations is not as rare as one would suspect, however the actual incidence is difficult to estimate. This accident seems to be occurring most frequently in general and gastro-intestinal surgery followed by operations in gynaecology and obstetrics and orthopaedics. There have been only a few papers in the literature dealing with the topic of foreign bodies left in place after cardiac surgical procedures. In this paper two cases of gauze swabs left intrapericardially following cardiac surgery are presented. The issue goes far beyond professional significance alone, but raises important and critical questions of medical ethics let alone legal implications.

Child↗
PubMed1998

Cloning and functional characterisation of the mouse P2X7 receptor.

We have isolated a 1785-bp complementary DNA (cDNA) encoding the murine P2X7 receptor subunit from NTW8 mouse microglial cells. The encoded protein has 80%, and 85% homology to the human and rat P2X7 subunits, respectively. Functional properties of the heterologously expressed murine P2X7 homomeric receptor broadly resembled those of the P2X7 receptor in the native cell line. However, marked phenotypic differences were observed between the mouse receptor, and the other P2X7 receptor orthologues isolated with respect to agonist and antagonist potencies, and the kinetics of formation of the large aqueous pore.

Amino Acid Sequence↗