Epidemiological impact of a large number of false negative SARS-CoV-2 test results in South West England during September and October 2021

During September and October 2021, a substantial number of Polymerase Chain Reaction (PCR) tests in England processed at a single laboratory were incorrectly reported as negative. We estimate the number of false negative test results issued and investigate the epidemiological impact of this incident. We estimate the number of COVID-19 cases that would have been reported had the sensitivity of the laboratory test procedure not dropped for the period 2 September to 12 October. In addition, by making comparisons between the most affected local areas and comparator populations, we estimate the number of additional infections, cases, hospitalisations and deaths that could have occurred as a result of increased transmission due to false negative test results.We estimate that around 39,000 tests may have been false negatives during this period and, as a direct result of this incident, the most affected areas in the South-West of England could have experienced between 6000 and 34,000 additional reportable cases, with a central estimate of around 24,000 additional reportable cases. Using modelled relationships between key variables, we estimate that this central estimate could have translated to approximately 55,000 additional infections.Each false negative likely led to around 1.5 additional infections. The incident is likely to have had a measurable impact on cases and infections in the affected areas in the South-West of England. IMPACT STATEMENT: These results indicate the significant negative impact of incorrect testing on COVID outcomes; and make a substantial contribution to understanding the impact of testing systems and the need to ensure high accuracy in testing and reporting of results.

Integrating blue: How do we make nationally determined contributions work for both blue carbon and local coastal communities?

Blue Carbon Ecosystems (BCEs) help mitigate and adapt to climate change but their integration into policy, such as Nationally Determined Contributions (NDCs), remains underdeveloped. Most BCE conservation requires community engagement, hence community-scale projects must be nested within the implementation of NDCs without compromising livelihoods or social justice. Thirty-three experts, drawn from academia, project development and policy, each developed ten key questions for consideration on how to achieve this. These questions were distilled into ten themes, ranked in order of importance, giving three broad categories of people, policy & finance, and science & technology. Critical considerations for success include the need for genuine participation by communities, inclusive project governance, integration of local work into national policies and practices, sustaining livelihoods and income (for example through the voluntary carbon market and/or national Payment for Ecosystem Services and other types of financial compensation schemes) and simplification of carbon accounting and verification methodologies to lower barriers to entry.

An analysis of the potential positive and negative livelihood impacts of coastal carbon offset projects

Carbon offset credits, and associated projects, are acclaimed to address economic, environmental and social issues simultaneously. However, critics argue that carbon offset mechanisms are ill equipped to assist developing countries in achieving sustainable development. Social standards now exist to provide robust methods for assessing the social and biodiversity performance of carbon offset projects and credible impact assessments to help ensure positive outcomes for local people and biodiversity. Following such a standard, and simultaneously applying the Sustainable Livelihoods Approach, we develop the Coastal Carbon Impacts Framework (CCIF) as a conceptual framework to document the potential positive and negative impacts of coastal carbon offset projects on local livelihoods. We apply the CCIF to four case studies and derive its main livelihood outcomes as well as describe potential long-term impacts. By using the capitals approach, the CCIF is able to dismantle the different impact areas into smaller entities. This allows a more detailed analysis on the positive and negative impacts a project has on communities - across the natural, financial, social, human, physical, cultural and political capital. While the case studies analysed show mainly positive outcomes, certainly no project is without risk of negatively impacting the community. The CCIF is however able to demonstrate potential social risk areas. If applied to additional coastal carbon offset projects, best practice documents, community engagement and the monitoring and evaluation process of such projects can be improved.

Diagnostic Methods of Ectopic Pregnancy and Early Pregnancy Loss: a Review of the Literature

This review article presents recent evidence on early pregnancy loss and ectopic pregnancy. In the light of recent evidence, the β-hCG discriminatory zone may be extended in clinically stable cases without evidence of bleeding. A possible cut-off is 4300 mIU/ml, which corresponds to when a sonographer should detect an intrauterine pregnancy. Embryonic demise can be confirmed when a transvaginal ultrasound finding shows no heartbeat in an embryo of more than 7 mm CRL, no embryo in a gestational sac having a mean sac diameter of more than 25 mm, or no appearance of an embryo within 7-10 days after the primary examination. These are considered definitive signs of embryonic demise. Suggestive signs of embryonic demise require closer monitoring of the pregnancy.

Abstract OT1-03-08: DESIREE - A multicenter, randomized, double-blind, phase II study to evaluate the tolerability of an induction dose escalation of everolimus in patients with metastatic breast cancer

Background: The BOLERO-2 study demonstrated a relevant benefit for patients who received everolimus in addition to exemestane in patients who progressed during/after a non steroidal aromatase inhibitor (NSAI), which led to approval of everolimus in this indication. However, in routine use a high rate of intolerability due to side effects is reported. The most common side effect of everolimus is mucositis with a reported high rate of intolerability especially during the first 12 weeks of treatment. Mucositis is also considered to be the leading cause for treatment discontinuation not related to tumor progression. In the neoadjuvant GeparQuinto study, a dose-escalation schema was successfully used to improve tolerability of everolimus together with cytotoxic agents.

Methods: DESIREE (NCT02387099) is a randomized, double-blind, phase II study of everolimus in addition to exemestane in patients who progressed during or after NSAI. Patients will be randomized in a 1:1 ratio to receive either everolimus 10 mg/day (week 1-3: 4x2.5 mg/day, blinded; week 4-24: 10mg/day, open according to label) or an escalating dose of everolimus as follows: week 1: 1x2.5 mg verum + 3x placebo/day; week 2: 2x2.5 mg verum + 2x placebo/day; week 3: 3x2.5 mg verum + 1x placebo/day; week 4-24: 10 mg/day (open according to label).

The primary aim of the study is to evaluate the incidence of the first episode of mucositis grade 2-4 (WHO's oral toxicity scale) any time during a 12 week period after start of everolimus treatment. Secondary objectives are to compare the cumulative rate of mucositis grade 2-4 at 24 weeks after start of treatment, the cumulative rate of mucositis grade 1 and any grade at 12 and 24 weeks after start of treatment, the rate of patients on 10 mg daily at 12 weeks and 24 weeks after start of treatment, the clinical benefit rate after 24 weeks, safety, time to onset of grade ≥2 mucositis, the cumulative everolimus dose at 4 weeks, the relative dose intensity for everolimus, and quality of life using the FACT-B and the QSDQ questionnaire. Biomaterial (whole blood, serum, plasma and optional primary tumor/metastasis tissue) will be collected to evaluate potential biomarkers predicting safety and compliance. Overall, 156 evaluable patients (78 in each arm) are required to detect a clinically relevant difference of 20% in the mucositis rate between treatment arms using a continuity-corrected χ2-test on a significance two sided level alpha of 0.2 and a power of 90%. The rate was estimated to be 40% and 20% in the control arm and the treatment arm, respectively.

Results: The study will be conducted in up to 60 German centers. Recruitment will start in June 2015. Enrollment is planned to be completed within 24 months.

Conclusion: The combination of everolimus and exemestane has shown to improve the outcome of patients with metastatic breast cancer. In the DESIREE trial a dose-escalating schema will be employed to enhance patient compliance and tolerability necessary to achieve an adequate dose-intensity.

Citation Format: Loibl S, Furlanetto J, Barinoff J, Bauerschlag D, Herr D, Lübbe K, Maass N, Müller V, Mundhenke C, Schmidt M, Schwedler K, Thill M, Gkantiragas I, Burchardi N, von Minckwitz G. DESIREE - A multicenter, randomized, double-blind, phase II study to evaluate the tolerability of an induction dose escalation of everolimus in patients with metastatic breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr OT1-03-08.

Electrochemotherapy in Breast Cancer: A Review of References

Electrochemotherapy is a new method for the local treatment of cutaneous and subcutaneous metastases. If surgery and/or radiotherapy are no longer possible, this innovative technology can be used effectively for local tumour control. The minor side effects of the therapy and the low intraoperative duration of treatment make it possible to admit patients to hospital for just a short time. Thus, the repeated use of electrochemotherapy has allowed for an increase in the rate of complete remissions. In fact, in 2013, this form of treatment, which consists of a low-dose cytostatic and electroporation, was also included in the mammary guidelines of the Working Group for Gynaecological Oncology (AGO) and the German Cancer Society (DKG). The favourable cost-benefit ratio makes this method of treatment very interesting in clinical practice and, as a result, it is already being used successfully in many German hospitals.

Therapy for Primary Vulvar Carcinoma

The rather rare vulvar cancer is almost always a squamous cell carcinoma that mostly develops from an underlying VIN or HPV infection. In addition, lichen sclerosus et atrophicans, immune deficiency, nicotine abuse or anogenital intraepithelial neoplasias may play a role in the pathogenesis. Surgical therapy aims at an R0 resection in the sense of a complete vulvectomy or a radical local excision with, if necessary, plastic reconstruction. Also, the vulvar field resection with consideration of the compartment model has been discussed. Besides the classic inguinofemoral lymphadenectomy, in selected cases of vulvar cancer sentinel biopsies are performed by experienced surgeons in the larger centres. In contrast, systemic therapy plays only a subordinate role; in isolated cases down-staging by means of neoadjuvant chemotherapy may be useful. However, there is at present no indication for adjuvant chemotherapy. Neoadjuvant radiochemotherapy is also not to be recommended on account of its unfavourable ratio of efficacy to side effects. On the other hand adjuvant radiotherapy is indicated in cases of positive inguinal lymph nodes. According to the current data the indication should be made generously in such cases.

Polyhydramnios: Causes, Diagnosis and Therapy

Polyhydramnios is defined as a pathological increase of amniotic fluid volume in pregnancy and is associated with increased perinatal morbidity and mortality. Common causes of polyhydramnios include gestational diabetes, fetal anomalies with disturbed fetal swallowing of amniotic fluid, fetal infections and other, rarer causes. The diagnosis is obtained by ultrasound. The prognosis of polyhydramnios depends on its cause and severity. Typical symptoms of polyhydramnios include maternal dyspnea, preterm labor, premature rupture of membranes (PPROM), abnormal fetal presentation, cord prolapse and postpartum hemorrhage. Due to its common etiology with gestational diabetes, polyhydramnios is often associated with fetal macrosomia. To prevent the above complications, there are two methods of prenatal treatment: amnioreduction and pharmacological treatment with non-steroidal anti-inflammatory drugs (NSAIDs). However, prenatal administration of NSAIDs to reduce amniotic fluid volumes has not been approved in Germany. In addition to conventional management, experimental therapies which would alter fetal diuresis are being considered.

Regulation of Endothelial Permeability in the Corpus Luteum: A Review of the Literature

The development of the human corpus luteum (yellow body) is dictated by a strictly controlled system of mutually communicating cells, the luteal steroid hormone-producing cells and endothelial cells. This cell-to-cell communication facilitates control of neoangiogenesis which is a prerequisite for the development of the corpus luteum and its function, the rapid release of large amounts of progesterone into the blood-vascular system. Preconditions for this process are the hormonal regulation of endothelial cell proliferation as well as of vascular permeability through LH and hCG. The morphological correlates of endothelial permeability are cell-to-cell adhesion molecules such as adherens junctions (AJ) and tight junctions (TJ) that open and close the gaps between mutually interacting, neighbouring endothelial cells like a "zip fastener". Various types of cell adhesion molecules have been detected in the corpus luteum such as occludin, claudin 1 and claudin 5 as well as VE-cadherin. It may be assumed that the regulation of AJ and TJ proteins is of particular importance for the permeability and thus for the function of the corpus luteum in early pregnancy since hCG treatment leads to a down-regulation of cell adhesion molecules in the luteal vessels. This effect is apparently mediated by VEGF. From a functional point of view, the hCG-dependent and VEGF-mediated down-regulation of cell adhesion molecules leads to a reduced transmissibility of cell-to-cell contacts and thus to an increased endothelial permeability. In this process the various cell adhesion molecules are not only directly regulated by VEGF but they also mutually interact and thus influence one another.

Taking action against ocean acidification: a review of management and policy options

Ocean acidification has emerged over the last two decades as one of the largest threats to marine organisms and ecosystems. However, most research efforts on ocean acidification have so far neglected management and related policy issues to focus instead on understanding its ecological and biogeochemical implications. This shortfall is addressed here with a systematic, international and critical review of management and policy options. In particular, we investigate the assumption that fighting acidification is mainly, but not only, about reducing CO2 emissions, and explore the leeway that this emerging problem may open in old environmental issues. We review nine types of management responses, initially grouped under four categories: preventing ocean acidification; strengthening ecosystem resilience; adapting human activities; and repairing damages. Connecting and comparing options leads to classifying them, in a qualitative way, according to their potential and feasibility. While reducing CO2 emissions is confirmed as the key action that must be taken against acidification, some of the other options appear to have the potential to buy time, e.g. by relieving the pressure of other stressors, and help marine life face unavoidable acidification. Although the existing legal basis to take action shows few gaps, policy challenges are significant: tackling them will mean succeeding in various areas of environmental management where we failed to a large extent so far.

Multivariate classification of blood oxygen level-dependent FMRI data with diagnostic intention: a clinical perspective

SUMMARY

There has been a recent upsurge of reports about applications of pattern-recognition techniques from the field of machine learning to functional MR imaging data as a diagnostic tool for systemic brain disease or psychiatric disorders. Entities studied include depression, schizophrenia, attention deficit hyperactivity disorder, and neurodegenerative disorders like Alzheimer dementia. We review these recent studies which-despite the optimism from some articles-predominantly constitute explorative efforts at the proof-of-concept level. There is some evidence that, in particular, support vector machines seem to be promising. However, the field is still far from real clinical application, and much work has to be done regarding data preprocessing, model optimization, and validation. Reporting standards are proposed to facilitate future meta-analyses or systematic reviews.

Chemotherapy for 70-Year-Old Women with Breast Cancer in Germany: A Survey by the German Breast Group

Aim: Around half of all women in Germany with breast cancer are older than 65 and approximately one third of them is older than 70 years of age. In theory, the preferred therapeutic management of women with breast cancer aged 65 and above corresponds to that formulated for younger patients and complies with the S3 Guidelines and the therapy recommendations formulated by AGO. To study the current therapies used to treat women with breast cancer aged 70 and above in Germany, a survey of the clinics of the German Breast Group (GBG) was done. Method: An online survey was carried out with requests sent to 599 physicians registered as principal investigators in the database of the GBG. The 12-item questionnaire was used to investigate the systematic therapeutic management of 70-year-old patients in different settings. The indication for chemotherapy was taken as a given. Results: In a neoadjuvant setting, 62 % of physicians opted for anthracycline and taxane-based therapy as did 56.6 % of physicians in an adjuvant setting. One third of physicians preferred a taxane-based therapy with the anti-angiogenesis inhibitor bevacizumab as first-line therapy for primary metastatic cancer and after anthracycline-based therapy. Capecitabine (around 30 %) and navelbine (around 20 %) were proposed as second-line neoadjuvant and adjuvant therapies after prior anthracycline- and taxane-based therapy. Conclusion: The chemotherapy regimen prescribed for women with breast cancer aged 70 and above in Germany appears to be relatively standardised and corresponds to the recommendations given in the S3 Guidelines and by the AGO Breast Committee.

Molecular mechanisms of ovarian hyperstimulation syndrome: paracrine reduction of endothelial claudin 5 by hCG in vitro is associated with increased endothelial permeability

BACKGROUND

Ovarian hyperstimulation syndrome (OHSS) is a potentially life-threatening complication of ovarian stimulation associated with severe vascular hyperpermeability. Primary co-cultures of human luteinized granulosa cells (LGCs) and human umbilical vein endothelial cells (HUVECs) were used as a model of steroidgenic/endothelial cell interaction in OHSS.

METHODS

hCG and the vascular endothelial growth factor (VEGF) inhibitor, Flt-1Fc, were added to co-cultures of LGCs and HUVECs separated by a micropore membrane. Endothelial permeability to labeled bovine serum albumin was measured and the expression of the endothelial cell-specific adhesion protein claudin 5 was investigated using immunocytochemistry and western blotting.

RESULTS

The addition of hCG increased HUVEC permeability in the presence of LGCs (P < 0.05). hCG increased VEGF concentrations in both chambers of the co-culture system (P < 0.05). The increased permeability in the presence of LGCs and hCG was inhibited when VEGF was blocked by Flt-1Fc (P < 0.05). Endothelial membrane claudin 5 protein was reduced in the presence of hCG and LGCs, as measured by immunocytochemistry (P < 0.05) and western blotting (P < 0.05) and this reduction was inhibited by Flt-1Fc. hCG had no direct effects on endothelial cell claudin 5.

CONCLUSIONS

For OHSS, this novel paradigm suggests that hCG can increase endothelial permeability by up-regulating VEGF in LGCs which causes reduction in endothelial claudin 5 expression.

Regulation of tight junction proteins occludin and claudin 5 in the primate ovary during the ovulatory cycle and after inhibition of vascular endothelial growth factor

Ovarian follicular and corpus luteum development, including angiogenesis, are characterized by cell-cell rearrangements that may require dynamic changes in cell-cell adhesion. The present study investigates the expression of tight junction proteins occludin and claudin 5 during follicular and luteal development in the primate ovary and after inhibition of vascular endothelial growth factor (VEGF) by VEGF trap treatment. Occludin was localized to the plasma membrane of granulosa cells. During follicular development occludin staining decreased significantly (P < 0.05) and disappeared completely by the ovulatory stage. After inhibition of VEGF, occludin staining was significantly (P < 0.05) higher in the granulosa of secondary and tertiary follicles compared with controls. Claudin 5 was exclusively localized to the theca vasculature. A significant (P < 0.05) increase in staining was detected from the pre-antral to the antral and ovulatory stage. However, dual staining with CD31 revealed that within the theca endothelium the amount of claudin 5 remained constant during follicular development. Treatment with VEGF trap throughout the follicular phase revealed a lack of claudin 5 staining in the theca interna but no difference was observed in the remaining theca externa vasculature. In the corpus luteum, claudin 5 was also localized in the vasculature. Treatment with VEGF trap in the mid-luteal phase resulted in a significant increase in staining (P < 0.05). These results led us to hypothesize that tight junctions are involved in regulation of follicular growth, antrum transition and follicular angiogenesis which is compromised by VEGF inhibition. VEGF may influence luteal vascular permeability by regulation of the endothelial specific tight junction protein claudin 5.

Regulation of endothelial proliferation by the renin–angiotensin system in human umbilical vein endothelial cells

This study was performed in order to evaluate the role of angiotensin II in physiological angiogenesis. Human umbilical vein endothelial cells (HUVEC) were stained for angiotensin II type 1 receptor (AGTR1) immunocytochemically and for gene expression of renin–angiotensin system (RAS) components. The regulation of the angiogenesis-associated genes vascular endothelial growth factor (VEGF) and angiopoietins (ANGPT1andANGPT2) were studied using quantitative RT-PCR. Furthermore, we examined the effect of angiotensin II on the proliferation of HUVEC using Ki-67 as well as BrdU immunocytochemistry and investigated whether the administration of the AGTR1 blocker candesartan or the VEGF antagonist FLT1-Fc could suppress the observed angiotensin II-dependent proangiogenic effect. AGTR1 was expressed in HUVEC and the administration of angiotensin II significantly increased the gene expression ofVEGFand decreased the gene expression ofANGPT1. Since the expression ofANGPT2was not affected significantly the ratio of ANGPT1/ANGPT2 was decreased. In addition, a significantly increased endothelial cell proliferation was observed after stimulation with angiotensin II, which was suppressed by the simultaneous administration of candesartan or the VEGF antagonist FLT1-Fc. These results indicate the potential capacity of angiotensin II in influencing angiogenesis by the regulation of angiogenesis-associated genes via AGTR1. Since VEGF blockade opposed the effect of angiotensin II on cell proliferation, it is hypothesised that VEGF mediates the angiotensin II-dependent effect in concert with the changes in angiopoietin expression. This is the first report of the RAS on the regulation of angiogenesis-associated genes in physiology.

Potential role of Renin-Angiotensin-system for tumor angiogenesis in receptor negative breast cancer

OBJECTIVE

This study examined the potential role of Angiotensin II for the regulation of angiogenesis associated genes in receptor positive and negative human breast cancer.

METHODS

Expression of different Renin-Angiotensin system (RAS) components in human breast cancer tissue was investigated using immunofluorescence, and in a receptor positive (MCF-7) and receptor negative (MDA-MB 468) breast cancer cell line by performing immunocytochemistry and RT-PCR. Both cell lines were stimulated with Angiotensin II and Angiotensin II receptor type 1 (At(1)R) blocker Candesartan, and gene expression of vascular endothelial growth factor (VEGF), Angiopoietin 1 and 2 (Ang-1 and Ang-2), tissue inhibitor of matrix metalloproteinases 1 (TIMP-1), and hypoxia inducible transcription factor 2alpha (HIF-2alpha) were quantified by TaqMan-Real-Time PCR analysis.

RESULTS

RAS components, Angiotensinogen, Renin, Angiotensin I-converting enzyme (ACE), and At(1)R and At(2)R were expressed in hormone-receptor negative and positive human breast cancer tissue as well as in MDA-MB 468 and in MCF-7 human breast cancer cells. In addition, we found expression of VEGF, Ang-1, TIMP-1, and HIF-2alpha in both cell lines. However, only in receptor negative MDA-MB 468 cells, did Angiotensin II significantly increase gene expression of VEGF, HIF-2alpha, and TIMP-1. This effect was completely inhibited by Candesartan.

CONCLUSION

In conclusion, it is hypothesized that Angiotensin II may be involved in regulation of tumor angiogenesis especially in receptor negative breast cancer by regulation of angiogenesis associated genes via At(1)R. These findings are the first evidence for targeting tumor angiogenesis by inhibition of At(1)R in receptor negative human breast cancer cells and may lead to new therapeutical anticancer strategies based upon inhibition of At(1)R.

Angiotensin II type 1 receptor antagonist candesartan is an angiogenic inhibitor in MDA-MB 468 human breast cancer cells

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Background: The present study examined the effect of angiotensin II on the regulation of different angiogenesis associated genes in human breast cancer cells and attempted to determine whether administration of At1R blocker candesartan could suppress the angiotensin II dependent gene regulation. Methods: Angiotensin II dependent expression of vascular endothelial growth factor (VEGF), tissue inhibitor of matrix metalloproteinases 1 (TIMP-1), and hypoxia inducible transcription factor 2alpha (HIF-2alpha) as well as administration of angiotensin II and At1R blocker candesartan was analyzed in MDA-MB 468 human breast cancer cells using immunofluorescence and TaqMan-Real-Time PCR analysis. Results: VEGF, TIMP-1, HIF-2alpha and the At1R were expressed in MDA-MB 468 human breast cancer cells. Angiotensin II significantly increased gene expression of VEGF, TIMP-1, and HIF-2alpha in these cells. This effect was completely inhibited by candesartan. Conclusion: It is hypothesized that angiotensin II is involved in regulation of tumor angiogenesis in breast cancer by regulation of angiogenesis associated genes via At1R. These findings are the first evidence for targeting tumor angiogenesis by inhibition of At1R in human breast cancer cells and may lead to new therapeutical anticancer strategies proposing administration of candesartan.

No significant financial relationships to disclose.

Cytochrome P2A13 and P1A1 gene polymorphisms are associated with the occurrence of uterine leiomyoma

PROBLEM

To investigate the association between the occurrence of uterine leiomyoma and two SNPs of the CYP 2A13 and CYP 1A1 genes.

METHOD OF STUDY

Prospective case control study with 132 women with clinically and surgically diagnosed uterine leiomyoma and 260 controls. Genotyping was performed by polymerase chain reaction (PCR) based amplification of CYP 2A13 and CYP 1A1 genes, and restriction fragment length polymorphism (RFLP) analysis.

RESULTS

Comparing women with uterine leiomyoma and controls, we demonstrate statistical significant differences of allele frequency and genotype distribution for the CYP 1A1 polymorphism (P = 0.025 and P = 0.046, respectively). Furthermore, for the CYP 2A13 polymorphism we found a significant difference concerning allele frequency (P = 0.033). However, for the genotype distribution, only borderline significance was observed (P = 0.064).

CONCLUSIONS

The CYP 2A13 and CYP 1A1 SNPs are associated with uterine leiomyoma in a Caucasian population and may contribute to the understanding of the pathogenic mechanisms of uterine leiomyoma.

hCG-dependent regulation of angiogenic factors in human granulosa lutein cells

As prerequisite for development and maintenance of many diseases angiogenesis is of particular interest in medicine. Pathologic angiogenesis takes place in chronic arthritis, collagen diseases, arteriosclerosis, retinopathy associated with diabetes, and particularly in cancers. However, angiogenesis as a physiological process regularly occurs in the ovary. After ovulation the corpus luteum is formed by rapid vascularization of initially avascular granulosa lutein cell tissue. This process is regulated by gonadotropic hormones. In order to gain further insights in the regulatory mechanisms of angiogenesis in the ovary, we investigated these mechanisms in cell culture of human granulosa lutein cells. In particular, we determined the expression and production of several angiogenic factors including tissue inhibitor of matrix metalloproteinases-1 (TIMP-1), Leptin, connective tissue growth factor (CTGF), meningioma-associated complimentary DNA (Mac25), basic fibroblast growth factor (bFGF), and Midkine. In addition, we showed that human chorionic gonadotropin (hCG) has distinct effects on their expression and production. hCG enhances the expression and production of TIMP-1, whereas it downregulates the expression of CTGF and Mac25. Furthermore it decreases the expression of Leptin. Our results provide evidence that hCG determines growth and development of the corpus luteum by mediating angiogenic pathways in human granulosa lutein cells. Hence we describe a further approach to understand the regulation of angiogenesis in the ovary.

Chorionic gonadotropin regulates the transcript level of VHL, p53, and HIF-2? in human granulosa lutein cells

The ovarian corpus luteum plays a critical role in reproduction being the primary source of circulating progesterone. After ovulation the corpus luteum is build by avascular granulosa lutein cells through rapid vascularization regulated by gonadotropic hormones. The present study was performed to investigate whether this process might be influenced by the human chorionic gonadotropin (hCG)-dependent expression of different tumor suppressor genes and hypoxia dependent transcription factors. RNA was isolated from cultured granulosa lutein cells, transcribed into cDNA, and the transcript level of following genes were determined: RB-1, VHL, NF-1, NF-2, Wt-1, p53, APC, and hypoxia inducible factor-1 (HIF-1), -2, and -3alpha. Additionally, the influence of hCG on the expression of VHL, p53, and HIf2alpha were investigated. We demonstrate that in human granulosa lutein cells the tumor suppressor genes RB-1, VHL, NF-1, NF-2, Wt-1, p53, and APC and the hypoxia dependent transcription factors HIF-1alpha, -2alpha, and -3alpha are expressed. In addition, we showed that hCG regulates the expression of p53, VHL, and HIF-2alpha. Our results indicate that hCG may determine the growth and development of the corpus luteum by mediating hypoxic and apoptotic pathways in human granulosa lutein cells.

Regulation of endothelin-1 and transforming growth factor-beta1 production in cultured proximal tubular cells by albumin and heparan sulphate glycosaminoglycans

BACKGROUND

Both endothelin-1 (ET-1) and transforming growth factor beta 1 (TGF-beta1) have been implicated in the progression of interstitial fibrosis. In the present study we enquired if albumin influences the production of these factors in cultured human proximal tubular epithelial cells (PTEC) and if heparan sulphate glycosaminoglycans (HS-GAG) can inhibit this production.

METHODS

ET-1 and TGF-beta1 production in supernatants of PTEC was measured by RIA and ELISA respectively. In addition semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) was performed to study differences in ET-1 and TGF-beta1 mRNA expression. To demonstrate ET-1 or TGF-beta1 binding to heparin or HS-GAG, binding studies by means of dot blot analysis were carried out.

RESULTS

TGF-beta1 and ET-1 were both produced in different concentrations, depending on the PTEC culture tested. Human serum albumin (HSA) up-regulated the production of both factors in a time and dose dependent fashion. The production of these factors was inhibited by heparin under basal and stimulatory conditions. ET-1 production was only inhibited by HS-GAG with a high degree of sulphation. For the inhibition of TGF-beta1 production, the sulphation of HS-GAG was less critical. TGF-beta1, but not ET-1 mRNA expression was inhibited by HS-GAG. Inhibition of sulphation of cell surface HS-GAG resulted in the inhibition of ET-1 but not TGF-beta1 production. Both factors were able to bind to HS-GAG, although this required different amounts of HS-GAG sulphation for each factor.

CONCLUSIONS

Our data demonstrate that in PTEC the release of pro-fibrogenic factors can be inhibited by HS-GAG. This may explain to some extent the beneficial effect of heparin in the treatment of interstitial fibrosis.

Treatment of chronic renal allograft rejection in rats with a low-molecular-weight heparin (reviparin)

BACKGROUND

Low-molecular-weight heparin (LMWH) has been shown to prolong survival of rat cardiac allografts independently from immunosuppressive treatment. Furthermore, long-term treatment reduces the development of chronic graft vascular disease after experimental heart transplantation. The aim of the present study was to determine whether treatment with the LMWH reviparin has a beneficial effect on chronic rejection in a rat renal allograft model.

METHODS

Kidneys of Fisher (F344) rats were transplanted into unilaterally nephrectomized Lewis (LEW) recipients. LEW-->LEW isografts served as controls. Animals were treated with cyclosporine (5 mg/kg/d) for the first 10 days. Nephrectomy of the remaining kidney was performed after 10 days. Allografted animals were treated either with reviparin (2 mg/kg/d subcutaneously) for 24 weeks (Allo-24), from week 12 to 24 (Allo-12), or with vehicle for 24 weeks. Proteinuria was determined at regular intervals. Kidneys were harvested after 24 weeks for histomorphological and immunohistochemical evaluation.

RESULTS

No major bleeding complications were observed in reviparin-treated animals. Proteinuria was significantly reduced in allografted animals both by early as well as by late-onset treatment with reviparin. Transplant glomerulopathy was diminished in Allo-24 and in Allo-12 groups compared to vehicle-treated animals, whereas tubulointerstitial inflammation was influenced only in animals immediately treated with reviparin. Immunohistochemical studies demonstrated a marked reduction of renal monocyte and T-cell infiltration as well as expression of MHC II by treatment with reviparin.

CONCLUSIONS

Treatment with the LMWH reviparin significantly improved chronic renal allograft rejection in the F344-to-LEW rat model, both after early and late start of therapy. Although the exact mechanisms of this beneficial effect remain unclear, our data offer a potential new therapeutical approach for prevention of chronic allograft nephropathy.