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P Simon

Publications and source records attributed to P Simon.

At least 55 records · Page 3Linked to original sources
PubMed2002

Utilization of Lactobacillus sp. for steroid glycoalkaloids degradation by lactic acid fermentation.

The degradation fo steroid glycoalkaloids (SGAs) has been studied in model solutions. The number of colony forming units (CFU) was determined using a nondirect (cultivation) method during all stages of fermentation. The changes in SGAs content were observed by HPLC on the Supelcosil LC-NH2 column. The changes in alpha-tomatine concentration added to fermented Lactobacillus MRS broth have been studied. A mathematical model of steroid glycoalkaloids degradation during lactic fermentation was proposed. The mathematical model was based on the experimental data of SGA and glucose concentration and should be used for study and prediction of SGA concentration changes of fermented samples. The ratio of SGA degradation rate by fermentation and by lactic acid hydrolysis was calculated. The experimental data evaluated by proposed mathematical model for the selected strain of Lactobacillus plantarum 976H show real feasibility for SGA degradation by lactic acid fermentation.

Alkaloids↗
PubMed2002

Ki-67 immunostaining activity is higher in positive axillary lymph nodes than in the primary breast tumor.

BACKGROUND: The monoclonal antibody Ki-67 allows to investigate the proliferative activity of tumor and is a clinically useful marker to characterize breast cancer. In this study, we have compared Ki-67 activity in 38 primary breast tumors and in their respective positive axillary lymph nodes (ALNs). METHODS: Immunohistochemistry with the monoclonal antibody against Ki-67 was performed in 38 nodes positive breast carcinomas and in their respective positive ALNs. Statistical analysis was performed with the Student's t-test (2-tailed) for equality of means. RESULTS: The proliferation index measured by Ki-67 expression was significatively higher (p < 0.02) in ALN than in the primary tumor (29.8% v.s. 21.8%). CONCLUSION: These results strongly suggest a higher proliferation and perhaps aggressivity of metastatic neoplastic cells when compared with their respective primary tumor. Perhaps, in the future, these differences in proliferation behavior might be taken into account when considering the choice of the adjuvant therapy.

Adult↗
PubMed2002

Hyperalgesia, nerve infiltration and nerve growth factor expression in deep adenomyotic nodules, peritoneal and ovarian endometriosis.

BACKGROUND: The aim of this study was to investigate a possible role for nerve growth factor (NGF) in the mechanism of pain and hyperalgesia induced by deep adenomyotic nodules and other forms of endometriosis and to clarify the relationship between endometriotic lesions and the surrounding nerves. METHODS: Endometriotic lesions (deep adenomyotic nodules, peritoneal endometriosis, ovarian endometriosis) and eutopic endometrium were obtained from 51 patients presenting with pain. Patients were allocated to two groups (group 1: patients with a deep adenomyotic nodule (n = 23); group 2: patients with peritoneal and/or ovarian endometriosis but without deep adenomyotic nodule (n = 28). Immunohistochemistry with antibodies against NGF, NGF specific tyrosine-kinase receptor (Trk-A) and S-100 protein was performed. Results were expressed as mean H-scores +/- SD, and correlated with the presence of hyperalgesia. RESULTS: The percentage of patients presenting hyperalgesia at physical examination was significantly higher in group 1 (96%) than in group 2 (11%) (P < 0.001). NGF expression was significantly stronger in deep adenomyotic nodules (DAN) than in ovarian (OE) and peritoneal endometriosis (PE), both in the proliferative phase in the glands [DAN: 226 +/- 18; OE: 140 +/- 9 (P < 0.001); PE: 110 +/- 7 (P < 0.001)] and in the stroma [(DAN: 204 +/- 21; OE: 125 +/- 15 (P < 0.001); PE: 100 +/- 9 (P < 0.01)]. NGF expression in DAN is also significantly stronger than in OE and PE in the secretory phase in the glands [DAN:181 +/- 32; OE: 85 +/- 3.3 (P < 0.001); PE: 65 +/- 9 (P < 0.001)] and in the stroma [DAN: 173 +/- 28; OE: 85 +/- 3.7 (P < 0.001); PE: 35 +/- 13 (P < 0.001)]. Perineurial and intraneurial invasion by endometriotic lesions were found only in deep adenomyotic nodules and not in the other forms of endometriosis. The specific receptor for NGF (Trk-A) is expressed in all the nerves that were included in the biopsies. CONCLUSIONS: These results suggest a role of NGF in endometriotic pain and hyperalgesia in deep adenomyotic nodules. The strong expression of the NGF-TrkA pathway in deep adenomyotic nodules could explain why this type of lesion infiltrates in richly innervated anatomical sites.

Adult↗
PubMed2002

The N34S mutation of SPINK1 (PSTI) is associated with a familial pattern of idiopathic chronic pancreatitis but does not cause the disease.

BACKGROUND: Mutations in the PRSS1 gene explain most occurrences of hereditary pancreatitis (HP) but many HP families have no PRSS1 mutation. Recently, an association between the mutation N34S in the pancreatic secretory trypsin inhibitor (SPINK1 or PSTI) gene and idiopathic chronic pancreatitis (ICP) was reported. It is unclear whether the N34S mutation is a cause of pancreatitis per se, whether it modifies the disease, or whether it is a marker of the disease. PATIENTS AND METHODS: A total of 327 individuals from 217 families affected by pancreatitis were tested: 152 from families with HP, 108 from families with ICP, and 67 with alcohol related CP (ACP). Seven patients with ICP had a family history of pancreatitis but no evidence of autosomal dominant disease (f-ICP) compared with 87 patients with true ICP (t-ICP). Two hundred controls were also tested for the N34S mutation. The findings were related to clinical outcome. RESULTS: The N34S mutation was carried by five controls (2.5%; allele frequency 1.25%), 11/87 (13%) t-ICP patients (p=0.0013 v controls), and 6/7 (86%) affected (p<0.0001 v controls) and 1/9 (11%) unaffected f-ICP cases. N34S was found in 4/108 affected HP patients (p=0.724 v controls), in 3/27 (11%) with wild-type and in 1/81 (1%) with mutant PRSS1, and 4/67 ACP patients (all p>0.05 v controls). The presence of the N34S mutation was not associated with early disease onset or disease severity. CONCLUSIONS: The prevalence of the N34S mutation was increased in patients with ICP and was greatest in f-ICP cases. Segregation of the N34S mutation in families with pancreatitis is unexplained and points to a complex association between N34S and another putative pancreatitis related gene.

Adult↗
PubMed2002

[Osteosynthesis and radiotherapy of the proximal femur: report of 6 cases].

PURPOSE OF THE STUDY: Post-radiation shaft fractures of long bones are uncommon. Late or partial healing increases the risk of stress fracture. Different fixation techniques have been proposed. Treatment of radiated bone is difficult. We report a series of 6 nonunions of the proximal femur after radiotherapy. MATERIAL AND METHODS: Three patients had true fractures of irradiated bones several years after radiotherapy for bone or soft tissue tumors. Three other patients had pathological fractures or malignant osteolysis related to a myeloma and treated by osteosynthesis and post-operative radiotherapy. RESULTS: Treatment required a total of 19 surgical procedures. There were nine stress fractures of ostheosynthesis material involving locked nails, cervicodiaphyseal nails and plates. There were no vascularized grafts in this series. At last follow-up the pathological fracture had healed in three cases, was stable but not healed in two, and required prosthetic reconstruction in one. CONCLUSION: We emphasize the importance of rigorous patient selection for radiotherapy and the possible preventive effect of osteosynthesis in certain cases with a high risk of secondary fracture of an irradiated bone. Vascularized grafts may be useful for refractory nonunion and may be proposed as first line treatment for post-radiation fractures.

Aged↗
PubMed2002

[Progression of choroidal neovascularization after macular translocation in age-related macular degeneration and degenerative myopia].

PURPOSE: To study the progression of choroidal neovascularization (CNV) after macular translocation in age-related macular degeneration (AMD) and degenerative myopia. PATIENTS AND METHODS: The data from 42 consecutive eyes (28 AMD, and 14 degenerative myopia) operated on by limited macular translocation (DeJuan technique), with a follow-up of 6 months or more, were prospectively analyzed. In the AMD group, neovascularization was classic in 54% of eyes and classic and occult in 46% of eyes. Previous laser treatment was applied on extra- or juxtafoveal CNV in 3 eyes. The major outcome measures were visual acuity, fluorescein and indocyanine green angiographies. RESULTS: After translocation, foveal displacement was greater in AMD than in myopic eyes (mean: 1 260 and 812 micro m, respectively). Laser photocoagulation was applied postoperatively onto extra-or juxtafoveal CNV in 26 (93%) AMD eyes and 12 myopic eyes (86%). Mean follow-up was 10 months (range, 6-18 months). Recurrence of CNV occurred in 14 AMD eyes (50%) and 2 myopic eyes (14%) an average of 5.6 months after surgery (range, 1-18 months). Recurrence was more frequent in AMD eyes with preoperative occult CNV (66%) than without (36%). Recurrence reached the new fovea in 69% of cases. Supplementary laser treatment was possible and successful on extra- or juxtafoveal recurrence in 3 eyes. Recurrence was significantly correlated with a poor visual prognosis: eyes without recurrence or with extra- or juxtafoveal recurrence had a final gain in visual acuity of 2.4 lines, eyes with subfoveal recurrence had a loss of 1.3 lines, and eyes with diffuse recurrence had a loss of 4.2 lines. CNV appeared in a new area at a BSS injection site in one eye. Occult CNV seemed to fade relatively within the first postoperative weeks, but were unchanged at the end of follow-up. In one eye, a small polypoidal lesion near the disc noted preoperatively disappeared after surgery. CONCLUSION: Our results suggest that the surgical procedure does not affect the course of classic or occult CNV. The rate of recurrence of CNV after macular translocation seemed similar to that observed after conventional laser treatment for extrafoveal CNV in AMD. Neovascular recurrence is the most frequent postoperative complication and was frequently directed at the new fovea. Despite these complications, macular translocation moves CNV outside of the subfoveolar zone so the eyes can be treated with conventional laser, leading to a favorable outcome at the last follow-up in 57% of cases. Further studies are required to confirm these findings and to define the best criteria for treatment.

Choroid↗
PubMed2002

[Traumatic bilateral rotatory C1-C2 dislocation in an adult: case report and review of the literature].

Trauma led to bilateral rotatory atlantoaxial dislocation in a 23-year-old woman. Clinical diagnosis of this uncommon dislocation of the cervical spin is generally difficult and often made late. Typical signs include pain in the upper cervical spine and a fixed rotated position of the head. Integrity of the transverse ligament of the atlas is a determining factor for atlantoaxial stability and allows orthopedic treatment after reduction using moderate traction on the head. As for most authors, orthopedic was successful in our patient who totally recovered cervical spine mobility without pain.

Accidents, Traffic↗
PubMed2002

[The gynecology-obstetrics department].

The scientific and clinical activities of the Department of Obstetrics and Gynaecology have involved the three main subdivisions: the gynecological surgery, the obstetrics and fetal medicine, the endocrinology and the reproductive medicine. Minimal invasive surgery including laser assisted laparoscopy or robotic assisted surgery has been particularly developed. Endometriosis, a frequent and sometimes particularly invasive disease, and oncologic surgeries have been developed in collaboration with the digestive surgery department. The department has also contributed to the comprehension and treatment of prenatal pathologies such as premature labor and deliveries or the gestational diabetes. The department has supported the development of techniques to study the fetal well-being in utero: the prenatal echography, the chorionic villous sampling, the amniotic puncture or the cordocentesis for prenatal genetic diagnosis or fetal infectious contaminations, the CMV transmission more specifically. In endocrinology and reproductive medicine, the department has mainly developed the in vitro fertilization techniques. The prolonged embryo culture, the study of preimplantation embryo metabolism, the preimplantation genetic diagnosis and the cryopreservation of ovarian fragments to preserve fertility in women undergoing oncologic treatments represent the more recent developed topics. Finally, the security of viral transmission in assisted procreation and the treatment of these patients with chronic viral diseases (Hepatitis C or HIV) are another domain with important scientific activity.

Belgium↗
PubMed2002

[The oto-rhino-laryngology and cervico-facial surgery department].

ENT department was present at the opening of the hospital but its activity began to increase in 1989. Now all the fields of modern ENT are present due to the collaboration of physicians very specialized in otology, rhinology, laryngology and head and neck surgery. Drilled in all surgical techniques using the best technologies available, the members of our team are also working in collaboration with the Laboratory of Histopathology in the field of nasal inflammation, cholesteatoma and malignant tumors of head and neck area.

Belgium↗
PubMed2001

Clinical characterization of patients with hereditary pancreatitis and mutations in the cationic trypsinogen gene.

PURPOSE: We determined the clinical manifestations of hereditary pancreatitis in nearly 30 families. PATIENTS AND METHODS: The two trypsinogen mutations N29I and R122H were identified in a group of 550 patients with chronic pancreatitis of unclear origin. The following criteria were used to characterize the severity of chronic pancreatitis (one point each): calcifications, cysts, dilation of the pancreatic duct, diabetes, hospital treatment, and operation. Stages were defined as stage 0 (no points), stage 1 (one to two points), stage 2 (three to four points), and stage 3 (more than four points). Smoking and drinking habits were also recorded. RESULTS: Six families with the N29I mutation (25 subjects with the mutation) and 21 families with the R122H mutation (76 subjects with the mutation) were identified. The median ages for the onset of disease were 11 years in N29I and 10 years in R122H patients. The severity of chronic pancreatitis and symptoms were similar for both mutations. About 26% (n = 26) of the 101 subjects carrying a mutation were asymptomatic, and 42% (n = 42) had mild disease (stage 1). Twenty-nine percent (n = 29) had moderate disease (stage 2), and only 4% (n = 4) had severe disease (stage 3). CONCLUSIONS: Symptoms of patients with the N29I or R122H trypsinogen mutation were generally similar. The majority of subjects with trypsinogen mutations had mild disease or was asymptomatic.

Adolescent↗
PubMed2001

Molecular defects underlying the Kell null phenotype.

Expression of the Kell blood group system is dependent on two proteins, Kell and XK, that are linked by a single disulfide bond. Kell, a type II membrane glycoprotein, is a zinc endopeptidase, while XK, which has 10 transmembrane domains, is a putative membrane transporter. A rare phenotype termed Kell null (Ko) is characterized by the absence of Kell protein and Kell antigens from the red cell membrane and diminished amounts of XK protein. We determined the molecular basis of eight unrelated persons with Ko phenotypes by sequencing the coding and the intron-exon splice regions of KEL and, in some cases, analysis of mRNA transcripts and expression of mutants on the cell surface of transfected cells. Six subjects were homozygous: four with premature stop codons, one with a 5' splice site mutation, G to A, in intron 3, and one with an amino acid substitution (S676N) in exon 18. Two Ko persons with premature stop codons had identical mutations in exon 4 (R128Stop), another had a different mutation in exon 4 (C83Stop), and the fourth had a stop codon in exon 9 (Q348Stop). Two Ko persons were heterozygous for two mutations. One had a 5' splice site mutation (G to A) in intron 3 of one allele that caused aberrant splicing and exon skipping, and the other allele had an amino acid substitution in exon 10 (S363N). The other heterozygote had the same amino acid substitution in exon 10 (S363N) in one allele and a premature stop codon in exon 6 (R192Stop) in the other allele. The S363N and S676N mutants, expressed in 293T cells, were retained in a pre-Golgi compartment and were not transported to the cell surface, indicating that these mutations inhibit trafficking. We conclude that several different molecular defects cause the Kell null phenotype.

Adult↗
PubMed2001

Orbital frustration at the origin of the magnetic behavior in LiNiO2.

We report on the ESR, magnetization, and magnetic susceptibility measurements performed over a large temperature range, from 1.5 to 750 K, on high-quality stoichiometric LiNiO2. We find that this compound displays two distinct temperature regions where its magnetic behavior is anomalous. With the help of a statistical model based on the Kugel'-Khomskii Hamiltonian, we show that below T(of) approximately 400 K, an orbitally frustrated state characteristic of the triangular lattice is established. This then gives a solution to the long-standing controversial problem of the magnetic behavior in LiNiO2.

Journal Article↗
PubMed2001

Detecting the Kondo screening cloud around a quantum dot.

A fundamental prediction of scaling theories of the Kondo effect is the screening of an impurity spin by a cloud of electrons spread out over a mesoscopic distance. This cloud has never been observed experimentally. Recently, aspects of the Kondo effect have been observed in experiments on quantum dots embedded in quantum wires. Since the length of the wire may be of order the size of the screening cloud, such systems provide an ideal opportunity to observe it. We point out that persistent current measurements in a closed ring provide a conceptually simple way of detecting this fundamental length scale.

Journal Article↗
PubMed2001

Translocation of the macula for management of subfoveal choroidal neovascularization: comparison of results in age-related macular degeneration and degenerative myopia.

PURPOSE: To report the results of limited macular translocation in subfoveal choroidal neovascularization resulting from age-related macular degeneration or degenerative myopia. METHODS: The first consecutive 32 patients (23 age-related macular degeneration eyes and nine myopic eyes) were operated on with the limited macular translocation technique described by de Juan. Before and after surgery, a complete examination included fluorescein and indocyanine-green angiographies and optical coherence tomography. Mean follow-up was 9 months in the age-related macular degeneration group (range, 6 to 14 months) and 10 months in the myopic group (range, 6 to 15 months). RESULTS: The improvement in visual acuity was better in the myopic group than in the age-related macular degeneration group and was correlated with younger age in the myopic group (P <.05). At the end of follow-up, visual acuity improved by 2 lines or more in seven age-related macular degeneration eyes (30%), including four eyes (13%) with an improvement of 6 lines or more, and in six myopic eyes (67%), including two eyes (22%) with an improvement of 6 lines or more. Final visual acuity was unchanged in four age-related macular degeneration eyes (17%) and three myopic eyes (33%), and decreased in 12 age-related macular degeneration eyes (52%). Conversely, the mean foveal displacement was greater in age-related macular degeneration than in myopia (1,105 microm and 685 microm, respectively; P <.05). Main complications were retinal detachment (six eyes), neovascularization at the injection site (two eyes), and recurrence of neovascularization (43% of the age-related macular degeneration group and 11% of the myopic group). CONCLUSIONS: Limited macular translocation allowed a significant improvement in visual acuity in some eyes with subfoveal neovascularization and resulted in a moderate rate of complications. Longer follow-up and additional studies are required to confirm these findings.

Adult↗
PubMed2001

Persisting active and proliferative intrinsic ureteral endometriosis under GNRH agonists therapy: a case with immunohistological study.

We report the case of a 30-year-old patient who underwent a segmental ureteral resection with ureteroureterostomy because of the presence of a left ureterohydronephrosis caused by an intrinsic ureteral endometriotic lesion. Preoperatively, the patient received a 3 months course of GNRH agonists. The serum estradiol level was at 12 pg/ml at the moment of surgery. Histology and immunohistochemistry performed on the resected specimen showed the presence of numerous large haemorrhagic endometriotic foci containing very high levels of alpha-estrogen and progesterone nuclear receptors, a high Ki-67 labeling index and a strong positivity for EGF-receptor. This is the first report of immunohistochemical study performed on ureteral endometriosis preoperatively treated with GNRH agonists. Because hormonal treatments are often prescribed in the treatment of ureteral endometriosis, clinicians should be aware of the possibility of persisting very active and proliferative ureteral endometriotic lesions even under treatment with GNRH agonists and very low levels of circulating estradiol.

Adult↗
PubMed2001

The levels of retinoid RARbeta receptors correlate with galectin-1, -3 and -8 expression in human cholesteatomas.

Cholesteatoma is a benign disease characterized by the presence of an unrestrained growth and the accumulation of keratin debris in the middle ear cavity. This often recurs, even when surgical resection is thought to be complete. In a previous study we showed that cholesteatomas with the highest apoptotic indices recurred more rapidly and also exhibited a high level of p53 immunopositive cells. In view of their relevance to the characterization of the cell differentiation status, the present study focuses on the expression of retinoid acid receptors (RARs) and galectins in human cholesteatomas. Retinoids control the differentiation processes in keratinocytes while galectins play strikingly modulatory roles at apoptosis and cell adhesion levels in a wide variety of tissue (embryonic, normal and neoplastic). To clarify the expression of these two protein families in human cholesteatomas we examined and quantified the levels of immunohistochemical expression of RARalpha, beta and gamma, and also galectin-1, -3 and -8 in a series of 70 human cholesteatomas. Our data show clearly that predominantly RARbeta and galectin-1 were expressed. The RARgamma concentration was significantly lower than that of the RARalpha; this was also observed for the galectin-8 concentration in comparison with the galectin-3 one. Furthermore, the level of RARbeta expression correlated highly (P=0.00001) with the level of galectin-8 expression, which also correlated significantly with the level of RARalpha and RARgamma expression. In addition, this parameter also correlated with the level of galectin-1 and galectin-3 expression. These data suggest that cholesteatomas may originate in an undifferentiated population of keratinocytes, and that a relation may exist between retinoid activity and galectins.

Adult↗