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1.
Ultrasound Obstet Gynecol ; 62(6): 891-903, 2023 12.
Article in English | MEDLINE | ID: mdl-37606287

ABSTRACT

OBJECTIVE: To assess the impact of photoacoustic imaging (PAI) on the assessment of ovarian/adnexal lesion(s) of different risk categories using the sonographic ovarian-adnexal imaging-reporting-data system (O-RADS) in women undergoing planned oophorectomy. METHOD: This prospective study enrolled women with ovarian/adnexal lesion(s) suggestive of malignancy referred for oophorectomy. Participants underwent clinical ultrasound (US) examination followed by coregistered US and PAI prior to oophorectomy. Each ovarian/adnexal lesion was graded by two radiologists using the US O-RADS scale. PAI was used to compute relative total hemoglobin concentration (rHbT) and blood oxygenation saturation (%sO2 ) colormaps in the region of interest. Lesions were categorized by histopathology into malignant ovarian/adnexal lesion, malignant Fallopian tube only and several benign categories, in order to assess the impact of incorporating PAI in the assessment of risk of malignancy with O-RADS. Malignant and benign histologic groups were compared with respect to rHbT and %sO2 and logistic regression models were developed based on tumor marker CA125 alone, US-based O-RADS alone, PAI-based rHbT with %sO2 , and the combination of CA125, O-RADS, rHbT and %sO2. Areas under the receiver-operating-characteristics curve (AUC) were used to compare the diagnostic performance of the models. RESULTS: There were 93 lesions identified on imaging among 68 women (mean age, 52 (range, 21-79) years). Surgical pathology revealed 14 patients with malignant ovarian/adnexal lesion, two with malignant Fallopian tube only and 52 with benign findings. rHbT was significantly higher in malignant compared with benign lesions. %sO2 was lower in malignant lesions, but the difference was not statistically significant for all benign categories. Feature analysis revealed that rHbT, CA125, O-RADS and %sO2 were the most important predictors of malignancy. Logistic regression models revealed an AUC of 0.789 (95% CI, 0.626-0.953) for CA125 alone, AUC of 0.857 (95% CI, 0.733-0.981) for O-RADS only, AUC of 0.883 (95% CI, 0.760-1) for CA125 and O-RADS and an AUC of 0.900 (95% CI, 0.815-0.985) for rHbT and %sO2 in the prediction of malignancy. A model utilizing all four predictors (CA125, O-RADS, rHbT and %sO2 ) achieved superior performance, with an AUC of 0.970 (95% CI, 0.932-1), sensitivity of 100% and specificity of 82%. CONCLUSIONS: Incorporating the additional information provided by PAI-derived rHbT and %sO2 improves significantly the performance of US-based O-RADS in the diagnosis of adnexal lesions. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.


Subject(s)
Adnexal Diseases , Ovarian Neoplasms , Photoacoustic Techniques , Female , Humans , Middle Aged , Ovarian Neoplasms/pathology , Prospective Studies , Ultrasonography/methods , Risk Assessment , CA-125 Antigen , Adnexal Diseases/pathology , Sensitivity and Specificity , Retrospective Studies
2.
Gynecol Oncol Rep ; 37: 100808, 2021 Aug.
Article in English | MEDLINE | ID: mdl-34169134

ABSTRACT

The role for localized radiation to treat ovarian cancer (OC) patients with locally recurrent vaginal/perirectal lesions remains unclear, though we hypothesize these patients may be salvaged locally and gain long-term survival benefit. We describe our institutional outcomes using intensity modulated radiation therapy (IMRT) +/- high-dose rate (HDR) brachytherapy to treat this population. Our primary objectives were to evaluate complete response rates of targeted lesions after radiation and calculate our 5-year in-field control (IFC) rate. Secondary objectives were to assess radiation-related toxicities, chemotherapy free-interval (CFI), as well as post-radiation progression-free (PFS) and overall survival (OS). PFS and OS were defined from radiation start to either progression or death/last follow-up, respectively. This was a heavily pre-treated cohort of 17 recurrent OC patients with a median follow-up of 28.4 months (range 4.5-166.4) after radiation completion. 52.9% had high-grade serous histology and 4 (23.5%) had isolated vaginal/perirectal disease. Four (23.5%) patients had in-field failures at 3.7, 11.2, 24.5, and 27.5 months after start of radiation, all treated with definitive dosing of radiation therapy. Patients who were platinum-sensitive prior to radiation had similar median PFS (6.5 vs. 13.4 months, log-rank p = 0.75), but longer OS (71.1 vs 18.8 months, log-rank p = 0.05) than their platinum-resistant counterparts. Excluding patients with low-grade histology or who were treated with palliative radiation, median CFI was 14.2 months (range 4.7 - 33.0). Radiation was well tolerated with 2 (12.0%) experiencing grade 3/4 gastrointestinal/genitourinary toxicities. In conclusion, radiation to treat locally recurrent vaginal/perirectal lesions in heavily pre-treated OC patients is safe and may effectively provide IFC.

3.
PLoS One ; 16(4): e0249447, 2021.
Article in English | MEDLINE | ID: mdl-33914774

ABSTRACT

Here we present our Python toolbox "MR. Estimator" to reliably estimate the intrinsic timescale from electrophysiologal recordings of heavily subsampled systems. Originally intended for the analysis of time series from neuronal spiking activity, our toolbox is applicable to a wide range of systems where subsampling-the difficulty to observe the whole system in full detail-limits our capability to record. Applications range from epidemic spreading to any system that can be represented by an autoregressive process. In the context of neuroscience, the intrinsic timescale can be thought of as the duration over which any perturbation reverberates within the network; it has been used as a key observable to investigate a functional hierarchy across the primate cortex and serves as a measure of working memory. It is also a proxy for the distance to criticality and quantifies a system's dynamic working point.


Subject(s)
Electrophysiology/methods , Neurons/cytology , Models, Neurological , Time Factors
4.
Gynecol Oncol ; 134(1): 24-8, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24823648

ABSTRACT

INTRODUCTION: Ccombination chemotherapy and radiation therapy is used for adjuvant treatment of stage III-IV endometrial cancer. The goal of this study was to review the treatment duration, toxicity, and survival for patients treated with concomitant chemotherapy and radiation. METHODS: Women with stage III-IV endometrial cancer treated with concurrent chemotherapy and radiation between 2006 and 2013 were included. Toxicities were classified per CTCAE v3.0 and RTOG/EORTC late radiation morbidity scoring. Descriptive statistics were used to quantify treatment and toxicities. Kaplan-Meier method was used to estimate survival. RESULTS: Fifty-one patients met our inclusion criteria. Median age was 60 (range 33-85). Thirty-six patients (70.6%) had endometrioid histology, 13 patients (25.5%) had serous, clear cell, or mixed histology, and 2 women (3.9%) had carcinosarcoma. Forty-eight patients had stage III disease and three patients were stage IVB. Mean treatment duration was 107 ± 19 days. Forty-two patients received all planned chemotherapy, and 16 patients required a dose reduction. Thirty-four patients (66.7%) experienced grade 3-4 toxicities, the majority of which were hematologic. There were no deaths related to therapy. Eighty-six percent of patients received leukocyte growth factors, and 25% of patients received a blood transfusion. Seven late grade 3-4 complications occurred: four gastrointestinal and two genitourinary, and one patient had ongoing neuropathy. Median progression-free survival was 42.8 months (range 4.4-81.5 months) and median overall survival was 44.9 months (range 5.1-82.6 months). Three-year overall survival was 80%. CONCLUSION: Concomitant chemotherapy and radiation is an adequately tolerated treatment modality that allows for shorter treatment duration.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Endometrial Neoplasms/drug therapy , Endometrial Neoplasms/radiotherapy , Adult , Aged , Aged, 80 and over , Carboplatin/administration & dosage , Chemoradiotherapy, Adjuvant , Endometrial Neoplasms/pathology , Female , Humans , Ifosfamide/administration & dosage , Middle Aged , Neoplasm Staging , Paclitaxel/administration & dosage , Radiotherapy, Intensity-Modulated , Retrospective Studies
5.
Food Sci Technol Int ; 19(3): 235-41, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23478913

ABSTRACT

Extended shelf life milk is a relatively new kind of fluid milk, generally manufactured by high-temperature treatment and/or micro-filtration. Being advertised as 'pasteurized milk with an extended shelf life', its flavour, compositional quality and labelling was questioned. Extended shelf life (high-temperature treatment), pasteurized ('traditionally produced') and ultrahigh-temperature milk were, therefore, compared at the beginning and end of shelf life. In triangle tests, panellists distinguished clearly between all products. High-temperature treatment milk's flavour was closer to ultrahigh-temperature and traditionally produced milk in the beginning and at the end of shelf life, respectively. Physicochemically and bacteriologically, all three types could be distinguished. Since 'extended shelf life' comprises many process varieties (each affecting flavour differently), consumer information and appropriate package labelling beyond 'long-lasting' is necessary, e.g. by mentioning the heat treatment applied.


Subject(s)
Food Handling/methods , Food Storage , Hot Temperature , Milk/chemistry , Animals , Food Microbiology , Milk/microbiology , Time Factors
7.
Med Klin Intensivmed Notfmed ; 106(1): 41-7, 2011 Sep.
Article in German | MEDLINE | ID: mdl-21975841

ABSTRACT

BACKGROUND: The number of patients of advanced age and with severe comorbidities undergoing cardiac surgery is rising. Therefore, in addition to the cardiac surgery procedure itself, postoperative intensive care treatment plays an increasingly important role. The mid-term outcome of patients with postoperative long-term stays in intensive care and perioperative risk factors for an adverse outcome have not been sufficiently evaluated. MATERIAL AND METHODS: All patients who underwent cardiac surgery in our institution between 2000 and 2004 and who required intensive care treatment on our cardiac surgery intensive care unit for at least 1 week were analyzed. Patients who received heart or lung transplantation or surgery for congenital heart failure were excluded. A total of 31 perioperative variables were evaluated for 230 patients. Follow-up was performed 1 year postoperatively. RESULTS: In all, 4.3% of our patients required a prolonged stay in intensive care following cardiac surgery. Overall 1-year mortality among patients with a long-term stay in intensive care was 26.9%. The logistic regression identified postoperative renal failure requiring dialysis (OR 4.98) as the strongest predictor for mortality within the first year after surgery, followed by postoperative tracheotomy and preoperatively known atrial fibrillation. CONCLUSION: Mid-term survival among patients who underwent cardiac surgery followed by a complicated postoperative course is encouragingly high. The risk factors identified for an adverse prognosis may be helpful in improving therapy strategies and general therapy decision-making.


Subject(s)
Critical Care/methods , Heart Diseases/mortality , Heart Diseases/surgery , Length of Stay/statistics & numerical data , Postoperative Complications/mortality , Postoperative Complications/therapy , Age Factors , Aged , Aged, 80 and over , Atrial Fibrillation/complications , Atrial Fibrillation/mortality , Female , Germany , Hospital Mortality , Humans , Kidney Failure, Chronic/mortality , Kidney Failure, Chronic/therapy , Male , Middle Aged , Prognosis , Renal Dialysis , Risk Factors , Survival Rate , Tracheotomy
8.
Philos Trans R Soc Lond B Biol Sci ; 363(1495): 1387-92, 2008 Apr 12.
Article in English | MEDLINE | ID: mdl-18198154

ABSTRACT

In this article, we describe the mechanisms by which morphogens in the Xenopus embryo exert their long-range effects. Our results are consistent with the idea that signalling molecules such as activin and the nodal-related proteins traverse responding tissue not by transcytosis or by cytonemes but by movement through the extracellular space. We suggest, however, that additional experiments, involving real-time imaging of morphogens, are required for a real understanding of what influences signalling range and the shape of a morphogen gradient.


Subject(s)
Activins/metabolism , Embryonic Induction/physiology , Morphogenesis/physiology , Signal Transduction/physiology , Xenopus/embryology , Animals
9.
J Dairy Sci ; 86(12): 3992-8, 2003 Dec.
Article in English | MEDLINE | ID: mdl-14740837

ABSTRACT

The objective of the study was to determine the effect of nutrition level (NL, multiples of maintenance energy requirement) on the digestibility of nutrients for dairy cows regarding the energy supply of the animal. The digestion of nutrients and energy was investigated in two trials using lactating dairy cows. The NL varied from 2.7 to 5.0 using diets similar composition. In addition, sheep were given the same feed with a NL of 1.4. Digestibility of dry matter (DM) and all specific measures of dietary components declined significantly as NL increased. Digestibility of energy decreased by 4.1% for each increase in NL. The metabolizable energy, the ability to metabolize energy (metabolizable energy/gross energy), and the content of net energy for lactation (NE(L)) per kilogram of DM intake were calculated for NL from 1 to 6 on the basis of these relationships and as well as the gross energy, methane energy, and urine energy. Accordingly the NEL content declined by 0.11 MJ/kg of DM intake or 1.6% as the NL increased by one unit. It means that the NE(L) requirement above the maintenance requirement increased by 0.07 MJ of NE(L) per kilogram of fat-corrected milk, if the NL increased by one unit.


Subject(s)
Cattle/physiology , Digestion , Energy Intake , Lactation , Nutritional Requirements , Animal Nutritional Physiological Phenomena , Animals , Energy Metabolism , Female , Male , Sheep
10.
Med Image Anal ; 6(4): 375-88, 2002 Dec.
Article in English | MEDLINE | ID: mdl-12426110

ABSTRACT

In order to improve the accuracy of image-guided neurosurgery, different biomechanical models have been developed to correct preoperative images with respect to intraoperative changes like brain shift or tumor resection. All existing biomechanical models simulate different anatomical structures by using either appropriate boundary conditions or by spatially varying material parameter values, while assuming the same physical model for all anatomical structures. In general, this leads to physically implausible results, especially in the case of adjacent elastic and fluid structures. Therefore, we propose a new approach which allows to couple different physical models. In our case, we simulate rigid, elastic and fluid regions by using the appropriate physical description for each material, namely either the Navier equation or the Stokes equation. To solve the resulting differential equations, we derive a linear matrix system for each region by applying the finite element method (FEM). Thereafter, the linear matrix systems are linked together, ending up with one overall linear matrix system. Our new approach has been tested and compared to a purely linear elastic model using synthetic as well as tomographic images. It turns out from our experiments, that the integrated treatment of rigid, elastic and fluid regions improves the physical plausibility of the predicted deformation results as compared to a purely linear elastic model.


Subject(s)
Brain/physiology , Magnetic Resonance Imaging/methods , Models, Neurological , Biomechanical Phenomena , Brain/surgery , Elasticity , Finite Element Analysis , Humans , Intraoperative Period , Linear Models , Neurosurgical Procedures/methods , Phantoms, Imaging
11.
IEEE Trans Med Imaging ; 18(10): 875-84, 1999 Oct.
Article in English | MEDLINE | ID: mdl-10628947

ABSTRACT

The accuracy of image-guided neurosurgery generally suffers from brain deformations due to intraoperative changes. These deformations cause significant changes of the anatomical geometry (organ shape and spatial interorgan relations), thus making intraoperative navigation based on preoperative images error prone. In order to improve the navigation accuracy, we developed a biomechanical model of the human head based on the finite element method, which can be employed for the correction of preoperative images to cope with the deformations occurring during surgical interventions. At the current stage of development, the two-dimensional (2-D) implementation of the model comprises two different materials, though the theory holds for the three-dimensional (3-D) case and is capable of dealing with an arbitrary number of different materials. For the correction of a preoperative image, a set of homologous landmarks must be specified which determine correspondences. These correspondences can be easily integrated into the model and are maintained throughout the computation of the deformation of the preoperative image. The necessary material parameter values have been determined through a comprehensive literature study. Our approach has been tested for the case of synthetic images and yields physically plausible deformation results. Additionally, we carried out registration experiments with a preoperative MR image of the human head and a corresponding postoperative image simulating an intraoperative image. We found that our approach yields good prediction results, even in the case when correspondences are given in a relatively small area of the image only.


Subject(s)
Brain/physiology , Magnetic Resonance Imaging/methods , Models, Neurological , Skull/physiology , Biomechanical Phenomena , Brain/pathology , Brain/surgery , Elasticity , Finite Element Analysis , Humans , Intraoperative Period , Magnetic Resonance Imaging/statistics & numerical data , Neurosurgical Procedures/methods , Neurosurgical Procedures/statistics & numerical data , Skull/pathology , Skull/surgery
12.
Dan Med Bull ; 44(5): 486-98, 1997 Nov.
Article in English | MEDLINE | ID: mdl-9408735

ABSTRACT

The literature has been provided with conflicting results concerning prorenin in rat plasma. The cause was investigated and we characterized severe methodological problems. Prorenin is in rats measured by its enzymatic property after trypsin activation. Besides activating prorenin, trypsin appeared to degrade renin substrate (angiotensinogen) and formed an unstable 'blank' which interfered in the prorenin measurement. An interfering sulphydryl enzyme was also found in plasma from nephrectomized rats. Identical 'blank' problems were also found in other animals such as pigs and cattle. These problems were solved and a new validated method was developed enabling the study of active renin and prorenin in species other than humans. Plasma prorenin was found primarily to originate from kidneys in rats as in other species although minor contribution of other tissues was likely. Evidence has accumulated during recent years supporting the existence of local tissue RAS's in ovary and uteroplacental unit. The presence of active renin and prorenin in female reproductive organs were verified in cattle and pigs. A marked species difference was found. Secretion of prorenin to plasma only seemed to take place in humans suggesting primarily a local function of reproductive RAS's. The concentration of prorenin varies during follicular maturation and pregnancy in reproductive tissues and fluids. A tissue incubation method was developed to study the bovine ovarian RAS in-vitro. The presence, formation, secretion and degradation of active renin in bovine ovarian follicles in-vitro indicate that active renin--and not prorenin as suggested earlier--is important in mediating effects of tissue RAS. Angiotensin II receptors are also present in high and varying densities in the ovary, uterus and placenta. Several potential effects, mediated through auto- or paracrine actions, are suggested. Ovarian RAS may affect oocyte maturation, ovulation, steroidogenesis and angiogenesis. The uteroplacental RAS may affect decidualization, angiogenesis, hormone synthesis, local blood flow and uterine contraction. Effects may, according to the marked species difference of RAS, vary between species. The understanding of tissue RAS's is in its infancy. The ovary seems to be a very good model in study of tissue RAS's and their possible relations to the bloodborne RAS. Further investigation may also benefit the reproductive endocrinology.


Subject(s)
Enzyme Precursors/analysis , Ovary/physiology , Placenta/physiology , Renin-Angiotensin System/physiology , Renin/analysis , Uterus/physiology , Animals , Enzyme Precursors/blood , Female , Humans , Pregnancy , Renin/blood
13.
Exp Clin Endocrinol Diabetes ; 105(5): 271-6, 1997.
Article in English | MEDLINE | ID: mdl-9354855

ABSTRACT

The relationship between follicular fluid concentrations of oestradiol (E2) and progesterone (P4), and follicular wall tissue renin concentrations and in-vitro secretion rates was investigated. The follicular fluid concentrations of prorenin correlated negatively with oestradiol and the E2/P4 ratio, and positively with progesterone in accordance with earlier findings. The high concentrations of active renin and prorenin in the follicular wall tissue, and the secretion rates of both active renin and prorenin all correlated positively with oestradiol and the E2/P4 ratio, but negatively with progesterone. These findings suggest that atretic follicles have higher follicular fluid renin concentrations but lower tissue renin concentrations and in-vitro secretion rates than healthy non-atretic follicles. The high follicular fluid prorenin concentrations in atretic follicles are most likely caused by a high prorenin secretion rate earlier in the oestrus cycle. The existence of relationships between the follicular fluid steroids and the follicular wall concentrations and secretion rates of active renin and prorenin indicates an interaction between the reninangiotensin system and steroidogenesis, but it may also reflect regulation by common factors, such as gonadotropins.


Subject(s)
Estradiol/metabolism , Follicular Fluid/metabolism , Progesterone/metabolism , Renin/metabolism , Animals , Cattle , Enzyme Precursors/metabolism , Female , In Vitro Techniques , Secretory Rate
14.
Anaesthesist ; 46(11): 964-8, 1997 Nov.
Article in German | MEDLINE | ID: mdl-9490584

ABSTRACT

We report the case of a 22-year-old woman who underwent two-step scoliosis surgery without allogeneic transfusion, although the intraoperative blood loss (3500 ml) during the first procedure was higher than the calculated blood volume (3250 ml). Preoperatively the patient had donated four units of autologous blood. Intraoperatively blood-saving methods were combined. During the first operation acute normovolemic hemodilution (target hemoglobin 9.0 g/dl) was applied and during the second operation controlled hypotension (systolic blood pressure 80 mmHg). Intraoperative auto-transfusion was used in both procedures. During the first operation severe normovolemic anemia (minimal hemoglobin 3.5 g/dl) was accepted while the patient was ventilated with FiO2 1.0. The hemoglobin concentration was 8.6 g/dl after the first procedure and had increased to 11.6 g/dl 4 weeks after the second procedure. No severe complications occurred during the postoperative phase. This case report shows that also in surgical procedures with extreme blood loss any allogenic transfusion can be avoided by the combination of blood-saving methods, acceptance of low intraoperative transfusion trigger and ventilation with 100% oxygen.


Subject(s)
Blood Loss, Surgical/physiopathology , Transfusion Reaction , Adult , Blood Loss, Surgical/prevention & control , Blood Transfusion, Autologous , Female , Humans , Scoliosis/surgery
16.
J Comput Assist Tomogr ; 19(3): 406-11, 1995.
Article in English | MEDLINE | ID: mdl-7790550

ABSTRACT

OBJECTIVE: The impact of injection flow rates, mono- or biphasic injection mode, and scan delay on liver and portal vein enhancement with helical CT was evaluated. MATERIALS AND METHODS: The liver of 75 consecutive patients was examined with helical CT before and after injection of 100 ml iopromide (30 g of iodine). Patients were randomly assigned to three protocols: (1) injection flow: 2 ml/s; (2) injection flow; 4 ml/s (60 ml) + 2 ml/s (40 ml); and (3) injection flow: 4 ml/s. Scanning started 40 s after the beginning of contrast material injection. A second scan was performed 70 s after contrast agent injection in Protocol 1. RESULTS: Mean parenchymal contrast enhancement was highest with Protocol 3 (48.5 HU) followed by Protocols 2 (38.9 HU) and 1 (early: 21 HU; late: 30.7 HU), with all differences being significant (p < 0.01). Enhancement of the portal vein was significantly higher with Protocols 3 and 2 (121 and 118 HU) than with Protocol 1 (early: 64 HU; late: 75 HU). CONCLUSION: Good enhancement of the liver parenchyma and the portal vessels can be obtained with 30 g of iodine if a monophasic injection with a flow rate of 4 ml/s is used.


Subject(s)
Iohexol/analogs & derivatives , Liver/diagnostic imaging , Tomography, X-Ray Computed/methods , Adult , Aged , Aged, 80 and over , Body Weight , Female , Humans , Injections, Intravenous , Male , Middle Aged , Prospective Studies , Radiographic Image Enhancement/methods
17.
Exp Clin Endocrinol Diabetes ; 103(5): 332-8, 1995.
Article in English | MEDLINE | ID: mdl-8536063

ABSTRACT

The expression of angiotensin (Ang) II receptors, active renin and prorenin in porcine and bovine ovarian follicles and corpora lutea was investigated and compared. In the wall tissue of porcine follicles, the Ang II receptor density was 47 (range 19-97; n = 13) fmol/mg membrane protein. The active renin concentration was 1.32 (0.40-3.43; n = 23) GU/kg wet tissue. These values were about 35-fold and 15-fold lower, respectively, than previously found in bovine follicles. No prorenin could be detected in the porcine follicular wall tissue. Ang II receptors of subtype 2 (AT2 receptors) with a dissociation constant (Kd) of 1.01 (0.64-1.79; n = 8) nmol/l for [Sar1-Ile5-Ile8]-Ang II were demonstrated in the bovine corpus luteum. The receptor density was 22.7 (1.9-93; n = 26) fmol/mg membrane protein, which was about 10-fold higher than in porcine corpora lutea. The active renin concentration was 20.7 (2.2-60.0; n = 26) GU/kg tissue in bovine and 0.40 (0.16-1.09; n = 17) GU/kg tissue in porcine corpora lutea. No prorenin could be detected in corpora lutea from both species. The variation between species in expression of the ovarian renin-angiotensin system indicates the existence of species differences in the physiological role.


Subject(s)
Cattle/metabolism , Ovary/metabolism , Receptors, Angiotensin/metabolism , Renin/metabolism , Swine/metabolism , Animals , Corpus Luteum/metabolism , Female , Osmolar Concentration , Ovarian Follicle/metabolism
19.
Adv Exp Med Biol ; 377: 407-10, 1995.
Article in English | MEDLINE | ID: mdl-7484443

ABSTRACT

The regulation of angiotensin (Ang) II receptor expression in ovarian follicles was reviewed. Ang II receptor expression, assessed as the Ang II binding capacity, varied with the animal species and the developmental stage of the follicle. In cows, the expression correlated positively with follicular size and negatively with the active renin concentration in the follicular wall tissue. No relations were found to the follicular fluid concentrations of prorenin, estradiol or progesterone. In cell cultures, luteinizing hormone up-regulated Ang II receptor expression in cows, whereas it was decreased by follicle-stimulating hormone, Ang II and testosterone in rats. These data support the concept of an active and regulated RAS in ovarian follicles. The species differences in Ang II expression suggest varying functional roles of the RAS between species.


Subject(s)
Angiotensin II/metabolism , Ovarian Follicle/metabolism , Ovary/metabolism , Receptors, Angiotensin/metabolism , Animals , Female , Humans , Rats
20.
Genetics ; 138(4): 1093-103, 1994 Dec.
Article in English | MEDLINE | ID: mdl-7896093

ABSTRACT

Duplicated DNA sequences in Neurospora crassa are efficiently detected and mutated during the sexual cycle by a process named repeat-induced point mutation (RIP). Linked, direct duplications have previously been shown to undergo both RIP and deletion at high frequency during premeiosis, suggesting a relationship between RIP and homologous recombination. We have investigated the relationship between RIP and recombination for an unlinked duplication and for both inverted and direct, linked duplications. RIP occurred at high frequency (42-100%) with all three types of duplications used in this study, yet recombination was infrequent. For both inverted and direct, linked duplications, recombination was observed, but at frequencies one to two orders of magnitude lower than RIP. For the unlinked duplication, no recombinants were seen in 900 progeny, indicating, at most, a recombination frequency nearly three orders of magnitude lower than the frequency of RIP. In a direct duplication, RIP and recombination were correlated, suggesting that these two processes are mechanistically associated or that one process provokes the other. Mutations due to RIP have previously been shown to occur outside the boundary of a linked, direct duplication, indicating that RIP might be able to inactivate genes located in single-copy sequences adjacent to a duplicated sequence. In this study, a single-copy gene located between elements of linked duplications was inactivated at moderate frequencies (12-14%). Sequence analysis demonstrated that RIP mutations had spread into these single-copy sequences at least 930 base pairs from the boundary of the duplication, and Southern analysis indicated that mutations had occurred at least 4 kilobases from the duplication boundary.


Subject(s)
Neurospora crassa/genetics , Point Mutation , Recombination, Genetic , Repetitive Sequences, Nucleic Acid , Base Sequence , DNA, Fungal/genetics , Molecular Sequence Data , Multigene Family , Sequence Alignment
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