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Biomedical subjects

F Becker

Publications and source records attributed to F Becker.

At least 19 recordsLinked to original sources
PubMed2007

Ultrastructural analysis reveals striking differences of intercellular contact lengths in bovine embryos produced in vivo, in vitro and by somatic cell nuclear transfer.

Cellular coherence and communication, thus cell-to-cell contact is an indispensable premise to sustain the formation of complex, multi-cellular organisms. We have analyzed intercellular contact lengths in NT-cloned bovine embryos compared to the in vivo or in vitro produced counterparts. Therefore, ultrastructural analysis was carried out by transmission electron microscopy (TEM) at the 8-cell and blastocyst stage of development. To obtain embryos generated in vivo, oviducts of superovulated cows were flushed 3 days after insemination, subsequent to slaughter. Standard in vitro maturation (IVM) and -fertilization (IVF) were utilized to obtain in vitro embryos. Cloned embryos by somatic nuclear transfer were produced by the handmade cloning (HMC) procedure. The points of apposition/focal contact points (CPs) between the blastomeres were of the shortest order in cloned embryos (236 +/- 135 nm) and of highest order in the in vivo produced embryos (2,085 +/- 1,540 nm), although no significant differences regarding the blastomere sizes in the various groups of 8-cell embryos could be established. In summary, the CP lengths in case of in vitro and in vivo 8-cell embryos were, on an average, five or nine times longer, respectively, than in the case of the cloned embryos. These differences of CP lengths vanished in embryos reaching the blastocyst stage of embryonic development in all the three groups of embryos. The observed differences of intercellular contact length at distinct stages of embryonic development could be responsible for differences in intercellular communication between the blastomeres at the beginning of cellular differentiation. These may be one reason for the lower developmental competence of cloned (NT) embryos.

Animals↗
PubMed2006

Pregnancy rates, LH and progesterone concentrations in mares treated with a GnRH agonist.

The aim of the study was to investigate the effect of the GnRH agonist Buserelin given on day 10 after ovulation on pregnancy rate and concentrations of progesterone and LH. Altogether 191 warmblood mares were used for two trials. Fresh or frozen/thawed semen from 27 stallions was used for A.I. In trial A 171 mares received either Buserelin (Receptal, Hoechst, Germany, 40 microg/animal) or 10 ml 0.9% NaCl (placebo). On day 16 after A.I. pregnancy diagnosis was performed by ultrasound scanning of the uterus. For statistical analysis, data were analyzed by a mixed model, with four fixed factors (treatment, type of spermatozoa, A.I. number, reproductive status of the mare) and a random factor (stallion). Least Square Means (LSM) for pregnancy rate were 46.0% in GnRH agonist treated mares and 36.4% in the control group (P=0.22). In trial B 20 lactating and cycling mares were used for endocrine studies. Blood samples were recovered for analyses of progesterone and LH from days 0 to 11. The mean progesterone concentrations increased continuously from days 0 to 8 after ovulation in both groups (GnRH group: from 0.81+/-0.48 to 5.47+/-0.48 ng/ml, control group: from 0.63+/-0.68 to 5.83+/-0.68 ng/ml). Moreover, the progesterone concentrations from days 9 to 11 were not different between the GnRH and the control group. In contrast to this LH concentrations were markedly influenced by the GnRH agonist. On day 10 LH concentrations were significantly higher in GnRH agonist treated than in placebo treated animals. From the data obtained from individual animals it can be concluded that GnRH agonist, given during luteal phase may have different effect on luteal function.

Animals↗
PubMed2006

[Lymphedema].

This paper report a CME course about lymphedema of upper and lower limbs. The anatomy and physiology of lymphatic system, the different forms of lymphatic insufficiency and the clinical characters of the lymphatic edema, primary and secondary lymphedemas, complications of lymphedema, treatment and prevention are discussed.

Humans↗
PubMed2006

Outcome of renal tumors in young adults.

PURPOSE: Sporadic RCC is rare in young adults. We retrospectively reviewed the outcomes of patients 20 to 40 years old at our institution. MATERIALS AND METHODS: Between 1975 and 2004, 2,710 patients were treated surgically for renal masses at our institution. We found 120 patients (4.4%) 20 to 40 years old. We analyzed the clinical presentation, pathological characteristics and outcome of these patients, and compared it to patients older than 40 years. RESULTS: The mean age of 120 young adults was 34.1 years (range 20.4 to 39.8). Symptomatic presentation was documented in 49.5% of patients. RCC was found in 87 (72.5%) young adults. Young patients generally had a higher rate of organ confined tumors than patients older than 40 years (73.6% vs 59.3%, p <0.05). Histopathological characteristics, tumor size, lymph node metastases and distant metastatic disease did not differ significantly in young and older patients. Women were significantly more likely to have benign lesions (41% vs 20%, p <0.05). Mean followup for 120 patients was 80.6 months and 15 of 87 patients with RCC (17.2%) died of tumor related causes (mean followup 27.5 months). The 10-year cancer specific survival rate was 78% in young adults and 68% in older patients (p = 0.22). Multivariate Cox regression analysis revealed lymph node metastases and tumor differentiation grade as independent prognostic parameters in young patients. CONCLUSIONS: Young patients are more likely to have symptomatic tumors at presentation. Nevertheless, they have more favorable pathological features and a definite trend to superior disease specific survival following surgical treatment. Organ sparing surgery should be considered in young women since benign lesions are frequent found in this population.

Adult↗
PubMed2006

[Elastic stockings and compression therapy, arguments favoring more rational use].

Elastic stockings and compression therapy are often considered as a major tool in the prevention and in the treatment of chronic venous insufficiency and of lymphedema. Nevertheless we must note that this therapeutic option is both underused and misused. We discuss the reasons for this paradox and the expected modes of action and pathophysiological benefits, and finally propose a prescription guide (indications, dosage, practice details) for a rational use of elastic stockings and compression therapy.

Humans↗
PubMed2006

Measurement of redox potential and steroid concentrations in the follicular fluid of growing and regressing follicles of mares.

The aim of this study was to prove if oxidation-reduction levels in the follicular fluid were new functional indices of follicular health and whether there was a high level of accordance with endocrinological parameters and with the growth stage as detected by ultrasound monitoring of individual follicles during the oestrous cycle in mares. Follicles were classified as growing and regressing follicles using ultrasonography. Altogether 48 follicles with a diameter from 20 to 56 mm were aspirated by transvaginal ultrasound guided follicular aspiration. Follicular concentration of oestradiol and progesterone in relation to the diameter of growing follicles showed correlations of r = 0.64 and r = 0.57, respectively. The redox potential derived index D2 varied from -448 to +431 in the collected fluids of the follicles. The accordance of the judgement of all follicles using both complexes of methods - endocrinological and ultrasonographic parameters vs. analysis of oxidation and reduction levels - reached 72.5%. This finding has shown that parameters of redox reactions do not correlate closely with the stage of follicular growth or regression as determined by in vivo scanning of ovaries or by assessment of follicular steroid concentrations. However, the measurement of redox potentials offers an opportunity to examine the whole process of metabolism in follicular cells and to forecast impairments of cellular performances. Changes of redox parameters in growing follicles enable an earlier prediction of their further development. The data demonstrate that growing and regressing follicles do not represent nonatretic, early atretic and atretic follicles, respectively.

Animals↗
PubMed2006

[The best of vascular medicine in 2005].

It is illusory to think that one year is long enough to establish all the truths that will guide our clinical practice in vascular medicine. On the contrary, one year was long enough to contradict what the preceding twelve months had set out to demonstrate. Consequently, promising trials in the treatment of abdominal aortic aneurysms by endoprostheses have been the object of contradictory debate with regards to the long-term benefits. In fundamental research, circulating progenitors of endothelial cells have been shown to be a marker of atherosclerosis, but is it a better marker than LDL-cholesterol values? The demonstration that these progenitors are of value in the treatment of essential ischaemia of the lower limbs is awaited. Finally, ximelagatran, a direct thrombin antagonist, seemed to have all the qualities of an ideal anticoagulant: easy to use, safe... until the report of raised hepatic enzymes, the clinical relevance of which remains to be determined. In the good news section: the Systolic Pressure Index, an unquestioned marker of arterial disease. Its reduction was known to be correlated with the prevalence of cardiovascular complications. However, it has now been shown that an increase in the index is also associated with cardiovascular complications, a real U-shaped curve. Renal arterial stenosis should be considered in patients with left ventricular failure presenting with flash pulmonary oedema. In the absence of cardiac pathology, BNP would seem to be a good biological marker of haemodynamically significant renal arterial stenosis. Finally, should superficial femoral artery stenosis be treated by an active stent. To date, there is no formal proof.

Angiogenesis Inhibitors↗
PubMed2005

Elective nephron sparing surgery should become standard treatment for small unilateral renal cell carcinoma: Long-term survival data of 216 patients.

OBJECTIVES: Our experiences with elective nephron-sparing surgery (NSS) for renal cell carcinoma (RCC) in a consecutive series of 216 patients are presented. Clinicopathological features and long-term oncological outcome is compared to patients treated with radical nephrectomy (RN). METHODS: Between 1975 and 2002, NSS was performed in 488 patients; 311 of these patients had elective indications. Renal cell carcinoma was found in 241/311 patients (77.5%). Long-term follow up data could be obtained in 216/311 patients. Cancer-specific survival was estimated using the Kaplan-Meier method. Cox's regression analysis and log-rank tests were used to evaluate independent predictive values of different clinicopathological features. Survival data of the 216 patients after NSS surgery were compared to 369 patients with small RCC treated with RN. RESULTS: After a mean follow up of 66 months (median 64 months) 29 (13.4%) of 216 patients treated with NSS had died, 4 of them (1.8%) tumour-related. Tumour recurrence was detected in 12 patients (5.6%). 204 patients (94.4%) were free of tumour at last follow-up. Cancer specific survival rates at 5 and 10 years for patients treated with NSS (RN) were 97.8% (95.5%) and 95.8% (84.4%). CONCLUSIONS: Elective NSS surgery provides optimal long-term outcome in patients with small localized RCC. Compared to RN, renal parenchyma is preserved without any disadvantage in survival rates. Consequently elective NSS should be accepted as gold standard for small renal tumours.

Adult↗
PubMed2005

Endocrine, morphological, and cytological effects of a depot GnRH agonist in bovine.

The present study was conducted to assess effects of the gonadotropin-releasing hormone agonist (GnRHa) triptorelin in dairy heifers. The peptide was released from a commercial 4-week depot formulation (Decapeptyl Depot) administered at animals' estrus (day 0). First experiment (EXP I, n=5), which was aimed to explore the availability of peptide, detected a maximum of triptorelin concentration between day 2 and 5 after depot injection, and the peptide remained detectable by RIA in peripheral blood for about 3 weeks. In further experiments, the peptide release was terminated on day 9 (EXP II, n=16) or day 21 (EXP III, n=47). Treatment effects were studied on follicular development, the characteristics of cumulus-oocyte complexes (COCs) (EXP II; EXP IIIa) and secretions of LH and progesterone (EXP IIIb). Results showed that the occurrence of the pre-ovulatory LH surge was more uniform in treated heifers than that in controls. The duration of ovulation periods was similar amongst the heifers of EXP II, but more compact amongst those of EXP III each compared with the respective controls. Post-ovulatory, the number of LH pulses was significantly reduced by treatment, whereas both basal LH and progesterone concentrations were elevated on a few days. Follicular growth was reduced only by the prolonged influence of the GnRHa. There were increased proportions of both degenerated COCs and immature oocytes from small follicles (<3mm in diameter), and meiotic configuration and quality of oocytes isolated from follicles 3-5mm were changed after the prolonged, 21-day treatment. These results indicate that a continuous influence of a GnRHa over more than 1 week may increasingly impair the development of bovine follicles and oocytes. This may have some significance for the development of novel GnRH-based techniques in regulating the reproductive function in cattle.

Animals↗
PubMed2005

[Thoracic outlet syndrome].

Careful clinical evaluation is the most important diagnostic tool for proper identification of thoracic outlet syndrome (TOS). TOS can be classified in hightly probable TOS (neurogenical, arterial, neuro-arterial, venous clear types) and in non-specific or disputed TOS which are the vast majority (including neurological compressions of subjective expression). Bony compressions, visible on X-ray pictures, are rare but can cause severe damages. More often than not, the underlying mechanism is a disorder or a weakness of the vertebro-scapular statics. The treatment is conservative including physical therapy and self-exercice of the whole vertebral and vertebro-scapular system first. Surgery is considered in case of arterial complications, of overt clinical bony compressions and in case of well performed physical therapy failure.

Chronic Disease↗
PubMed2005

Influence of ovarian steroid hormones or platelet-activating factor on mRNA of platelet-activating factor receptor in endometrial explant perfusion cultures from ovariectomized bovine.

Platelet-activating factor (PAF) and its receptors are involved in inflammatory-like processes of the uterus associated with increased vascular permeability. PAF is supposed to be influenced by ovarian steroid hormones. The present study was undertaken to examine whether progesterone (P(4)), estradiol (E(2)) or PAF influence the PAF receptor gene expression in perfused endometrial explants derived from ovariectomized bovine. Furthermore, we identified the cell types in which the PAF receptor gene and protein are expressed. In endometrial explants, applications of 10 nM P(4) or 10nM P(4) plus 10 nM E(2) for 24 h induced elevated transcript levels of PAF receptor in comparison to the controls or after treatment with 1 nM E(2). When explants were administered 10 nM E(2), a slight decrease in the transcript level was recorded. After treatment of explants with PAF, no significant changes in PAF receptor mRNA expression was observed compared to the control group. We demonstrate that PAF receptor immunoreactivity and mRNA are detected mainly in the luminal epithelium, epithelial cells of the superficial glands and to a lesser degree in stroma. Levels of PAF receptor mRNA in bovine endometrial explants were correlated with PAF receptor protein localization assessed by immunohistochemistry. The regulation of PAF receptor by progesterone in bovine endometrial explants suggests that PAF is involved in the physiological process of reproduction.

Animals↗
PubMed2005

[Effects of elastic stockings on venous flow during simple movements and muscular contractions of lower limb in healthy volunteers. Pilot study].

AIM: To study common femoral vein flow during simple movements and voluntary contractions of muscles of lower limbs in healthy volunteers and to evaluate the effects of elastic stocking on venous flow. METHODOLOGY: Experimental study. Ten subjects, aged 21 to 25 years, underwent duplex ultrasound to examine venous flow, the lower limb being fitted with sensors to characterize kinematics and of muscle activity. MOVEMENTS STUDIED: In supine position: thigh muscles contraction. forefoot dorsal flexion. Standing on both feet: thigh muscles contraction, tip-toe, front load transfer, extension of the leg on the knee, loading on one limb, forefoot back flexion. Data were recorded with a computerised system for secondary analysis. A mean venous velocity was calculated after elimination of parasite signals. Venous velocity was correlated with muscle signals. The procedure was repeated with the patient wearing a thigh-length class II elastic stockings (Varisma Innothera Ltd). RESULTS, CONCLUSION: All movements increased venous flow. Wearing elastic stockings increased the venous flush due to movements or muscle contractions. The level of muscle activity during the same movement or the same muscle contraction varied from one subject to the other.

Adult↗
PubMed2005

The venous return simulator: an effective tool for investigating the effects of external compression on the venous hemodynamics--first results after thigh compression.

BACKGROUND: To present a virtual model, the venous return simulator (VRS), designed to compute venous hemodynamic variations when compression is applied to the leg. METHODS: The VRS defines a numerical network of the lower extremity and computes the dynamic variables (flow rate, venous diameter and internal pressure) for a defined external pressure. The VRS was based on physiological data from the literature and clinical studies on healthy subjects. Clinical correlations were required to confirm its validity; for this purpose, we carried out experiments simulating the conditions of a clinical trial, in which the diameter of superficial and deep veins was measured while increasing pressures (20, 40 and 60 mmHg.) were applied to the thighs of patients enduring deep valvular insufficiency and venous ulcers. The diameters and flow rates calculated using our VRS model were compared with the experimental data obtained at the same thigh compression levels. RESULTS: The numerical results of VRS are in good agreement with the clinical data obtained by Duplex, (R2 = 0.96). In accordance with the in vivo measurement the computed results show that only a pressure greater than 40 mmHg is able to reduce the venous diameter at thigh-level, both in the great saphenous vein and in the femoral vein. CONCLUSION: The venous return simulator computes lower limb hemodynamic parameters under static conditions. The good correlation existing between the VRS and the data obtained in a previous clinical study shows that this numerical approach could provide a useful means of predicting the hemodynamic consequences of compression therapy.

Bandages↗
PubMed2005

Current TNM classification of renal cell carcinoma evaluated: revising stage T3a.

PURPOSE: : Recent studies of rare cases of pT3a renal cell carcinoma extending directly into the adrenal gland showed worse survival than in other pT3a cases and recategorization as stage pT4 was suggested. We assessed the prognostic validity of a stage pT3a diagnosis based on perirenal fat infiltration. MATERIALS AND METHODS: : The records of 1,794 patients with renal cell carcinoma who underwent surgical resection between 1975 and 2000 at our institution were analyzed retrospectively. Focusing on pT3a tumors, as defined by perirenal fat infiltration, numerous clinical and histopathological parameters were investigated by univariate and multivariate statistical methods with cancer specific survival as the primary end point. RESULTS: : We identified 237 of 1,794 patients with perirenal fat infiltration, classified as having pT3a disease. In patients with pT3a tumors tumor size was a significant parameter predicting survival. The most significant cutoff value for tumor size in pT3a disease was 7 cm. Patients with distant metastasis had a worse prognosis independent of T classification. Therefore, to assess the prognostic value of the current T classification in regard to T3a tumors we excluded patients with tumor stage cM+ for further subgroup analysis. Survival comparison of pT1 pNall, cM0 (744 of 1,794 cases) and pT3a pNall, cM0 7 cm or less (100 of 237) as well as pT2 pNall, cM0 (265 of 1,794) and pT3a pNall, cM0 greater than 7 cm (93 of 237) yielded similar results. After splitting pT3a into a modified T1/T2 classification a significant difference in 5-year survival analysis for a modified T1/T2 stage was found (pT1 plus pT3a less than 7 cm 90% vs pT2 plus pT3a greater than 7 cm 73%, p <0.001). Subsequently multivariate analysis in all 1,794 patients showed that modified T stage was an independent significant predictor of cancer specific survival. CONCLUSIONS: : We suggest revising the current pT3a classification based on perirenal fat infiltration but rendering a modified pT1/pT2 classification, which resolves pT3a cases without the loss of prognostic validity. Perirenal fat infiltration should not be used to assign T category. Tumors directly infiltrating the adrenal gland should be reclassified as T4.

Carcinoma, Renal Cell↗