Mammographic changes in postmenopausal women on hormonal replacement therapy

The purpose of this study was to investigate the extent of the effects of hormonal replacement therapy (HRT) on the mammographic breast pattern in postmenopausal women. In a hospital-based study mammographic examinations of 81 postmenopausal women were evaluated retrospectively, before and after 1–2 years of treatment with oestrogens or a combination of oestrogens and progestagens. Each individual mammographic film was examined separately, and the glandular tissue was classified according to a modified Wolfe classification. In a screening-centre-based study two consecutive mammograms, with a 2-year interval, of 645 women, of whom 70 were using some kind of hormone therapy, were evaluated retrospectively. In the hospital-based study 31% of patients treated with combination HRT showed an increase in fibroglandular tissue compared with only 8.7% in the group treated with oestrogens alone. The difference was statistically significant (p=0.046). In the screening-based study 14.3% of the women using hormonal therapy showed an increase, whereas in the non-users no increase was found (p=1.24×10⁻¹⁰). After beginning HRT many women (between 14 and 25% in our experience) can be expected to undergo a mammographically detectable increase in fibroglandular tissue. Radiologists should be aware of the aetiology of such changes, and can obtain information on HRT most conveniently by having the technologist routinely question each patient.     

P16INK4A immunostaining is a strong indicator for high‐risk‐HPV‐associated oropharyngeal carcinomas and dysplasias,but is unreliable to predict low‐risk‐HPV‐infection in head and neck papillomas and laryngeal dysplasias

Human papillomavirus (HPV) is a risk factor for the development of benign and malignant mucosal head and neck lesions. P16^INK4A is often used as a surrogate marker for HPV‐infection, although there is still controversy with respect its reliability. Our aim was to determine if p16^INK4A overexpression can accurately predict both high‐risk and low‐risk‐HPV‐presence in (pre)malignant and benign head and neck lesions. P16^INK4A immunohistochemistry was performed on paraffin‐embedded tissue sections of 162 oropharyngeal squamous cell carcinomas (OPSCC), 14 tonsillar and 23 laryngeal dysplasias, and 20 tonsillar and 27 laryngeal papillomas. PCR, enzyme‐immunoassay and FISH analysis were used to assess HPV‐presence and type. Of the 162 OPSCC and 14 tonsillar dysplasias, 51 (31%) and 10 (71%) were HPV16‐positive, respectively. All tonsillar papillomas were HPV‐negative and four laryngeal dysplasias and 26 laryngeal papillomas were positive for HPV6 or ?11. P16^INK4A immunohistochemistry revealed a strong nuclear and cytoplasmic staining in 50 out of 51 HPV16‐positive and 5 out of 111 HPV‐negative OPSCC (p < 0.0001) and in all HPV16‐positive tonsillar dysplasias, whereas highly variable staining patterns were detected in the papillomas and laryngeal dysplasias, irrespective of the HPV‐status. In addition, the latter lesions generally showed a higher nuclear than cytoplasmic p16^INK4A immunostaining intensity. In conclusion, our data show that strong nuclear and cytoplasmic p16^INK4A overexpression is a reliable surrogate indicator for HPV16 in OPSCC and (adjacent) dysplasias. For HPV6 or ?11‐positive and HPV‐negative benign and premalignant lesions of the tonsil and larynx, however, p16^INK4A immunostaining is highly variable and cannot be recommended to predict HPV‐presence.     

Tracing the Origin of Glomerular Extracapillary Lesions from Parietal Epithelial Cells

Cellular lesions form in Bowman''s space in both crescentic glomerulonephritis and collapsing glomerulopathy. The pathomechanism and origin of the proliferating cells in these lesions are unknown. In this study, we examined proliferating cells by lineage tracing of either podocytes or parietal epithelial cells (PECs) in the nephrotoxic nephritis model of inflammatory crescentic glomerulonephritis. In addition, we traced the fate of genetically labeled PECs in the Thy-1.1 transgenic mouse model of collapsing glomerulopathy. In both models, cellular bridges composed of PECs were observed between Bowman''s capsule and the glomerular tuft. Genetically labeled PECs also populated larger, more advanced cellular lesions. In these lesions, we detected de novo expression of CD44 in activated PECs. In contrast, we rarely identified genetically labeled podocytes within the cellular lesions of crescentic glomerulonephritis. In conclusion, PECs constitute the majority of cells that compose early extracapillary proliferative lesions in both crescentic glomerulonephritis and collapsing glomerulopathy, suggesting similar pathomechanisms in both diseases.Glomerular epithelial hyperplasia is an important characteristic of crescentic glomerulonephritis (CrGN), also known as rapidly progressive glomerulonephritis. Despite a wide variety of underlying causes, CrGN is characterized commonly by the development of cellular crescents (multilayered accumulation of cells in Bowman''s space) and necrosis of glomerular capillaries.¹ Loss of renal function occurs as a consequence of the obstruction of the tubular outlet by cellular crescents, so the proliferating cells present an important target for therapeutic interventions.²Collapsing glomerulopathy (CG) is characterized by massive proteinuria and rapid progressive renal insufficiency and histologically by segmental to global collapse of the capillary tuft and pronounced epithelial cell hyperplasia.³ This pattern has been described in HIV-associated nephropathy,⁴ parvovirus B19 infection,⁵ and pamidronate toxicity⁶ and also as an idiopathic form.³The pathomechanism of the development of cellular lesions remains to be established, and in both CrGN and CG the origin of the hyperplastic cells within cellular lesions has been a matter of debate. In CrGN, the cellular composition of crescents appears to change over time, with predominantly epithelial cells of unknown origin proliferating in early stages and increasing numbers of infiltrating macrophages, lymphocytes, and myofibroblasts in later stages, especially when Bowman''s capsule is ruptured.^7–9 Recent studies also pointed to a contribution of podocytes in the development of crescentic lesions.^10–13 Collapsing glomerulopathy lesions in turn often are associated with hyperplasia of epithelial cells covering the glomerular tuft, although connections to Bowman''s capsule appeared to be lacking. The visceral localization and the finding that these proliferating cells lacked expression of podocyte markers led to the concept of dysregulated podocytes, which are no longer growth restricted, causing epithelial hyperplasia.¹⁴ However, from the findings that these cells expressed markers normally expressed by PECs¹⁵ and the finding in serial sections that the cells on the tuft were connected to the PECs on Bowman''s capsule,¹⁶ we and others suggested that these cells may originate from parietal epithelial cells (PECs) rather than from podocytes.^16–20In the studies described above, the origin of the proliferating cells was identified based on the expression or loss of specific markers. This approach may be misleading, given that, first, PECs and podocytes share a common embryonic origin. Only during the last stages of nephrogenesis the phenotypes of both cells diverge. Second, PECs lack specific differentiation markers, and third, proliferating cells may possibly transdifferentiate into cells with a different phenotype. Genetic cell lineage tracing is a technique that has been established recently and enables one to trace cells over prolonged times, even when the cells switch to a different phenotype due to de- or transdifferentiation.^19,21 In the present study, we therefore used this technique to trace the relative contributions of PECs and podocytes in the development of cellular glomerular lesions in two murine models of CrGN, namely, nephrotoxic nephritis, and CG, namely, Thy-1.1 transgenic mice. These established murine models were chosen because both characteristically develop proliferative extracapillary lesions.     

Perinatal development of the lung in rat and spiny mouse: its relation to altricial and precocial timing of birth

Rat and spiny mouse (Acomys cahirinus) are closely related murinoid species that represent altricial (rat) and precocial (spiny mouse) modes of development. The late intrauterine developmental stages of the spiny mouse therefore seem comparable to the early extrauterine developmental stages of the rat. To elucidate the question to what extent the development of the lung is related to the developmental timing of birth, we have studied some enzymes involved in the de novo synthesis of phosphatidylcholine. Of the enzymes studied, cholinephosphate cytidylyltransferase shows peaks in activity in the perinatal period (rat and spiny mouse) and at the beginning of the 3rd postnatal week (rat only). This enzyme fulfills the requirements for a developmental parameter best as changes in activity of this enzyme can be correlated with phases of cell proliferation and surface expansion in the lung of the rat. The single peak of cholinephosphate cytidylyltransferase activity in the spiny mouse as well as microscopical examination of the lung support the hypothesis that the processes of proliferation and surface expansion, which occur consecutively in the rat, develop concurrently in the spiny mouse.     

Effects of transdermal and oral oestrogen replacement therapy on C-reactive protein levels in postmenopausal women: a randomised,placebo-controlled trial

To investigate the effect of postmenopausal oral and transdermal hormone therapy on plasma levels of C-reactive protein (CRP), we performed a randomised, double-blind, double-dummy, placebo-controlled, 15-month study. One hundred and fifty-two healthy hysterectomised postmenopausal women received daily either placebo (n = 49), or transdermal 17beta-oestradiol (E(2)) 50 micro g (tE(2) group, n = 33), or oral E(2) 1 mg (oE(2) group, n = 37), or oral E(2) 1 mg combined with gestodene 25 micro g (oE(2) + G group, n = 33) for thirteen 28-day treatment cycles, followed by four cycles placebo for each group. Data were collected at baseline and in cycles 4, 13 and 17. In cycle 13, CRP was significantly increased in the oE(2) group compared to placebo (P = 0.004). The median percentage change from baseline versus placebo was +75% (P <0.001). In cycle 17, significantly lower values were observed in the oE(2) group compared to cycle 13 and to the placebo group (-49%, P <0.001). There were no significant changes versus placebo in the other groups. In conclusion, oral E(2) significantly increased CRP levels. This change was larger than the increase found during oral E(2) + G. Transdermal E(2) did not affect CRP levels.     

Raloxifene reduces impedance to flow within the uterine artery in early postmenopausal women: a 2-year randomized, placebo-controlled, comparative study

OBJECTIVE: We sought to investigate the long-term effect of raloxifene and continuous combined hormone replacement therapy (ccHRT) on impedance to flow within the uterine artery in postmenopausal women. STUDY DESIGN: A prospective, randomized, double-blind, placebo-controlled 2-year study was performed in 95 postmenopausal women. They received either 60 mg of raloxifene daily (raloxifene 60 group), 150 mg of raloxifene daily (raloxifene 150 group), ccHRT, or placebo. At baseline and thereafter every 6 months, color Doppler ultrasonography was used to measure the pulsatility index (PI) of the uterine artery. RESULTS: After 24 months of treatment, compared with placebo, significant decreases were found in the PI in the raloxifene 150 group (P = .021) and in the ccHRT group (P = .007). In the raloxifene 150 group compared with the placebo group, after 6 and 24 months, decreases were observed in median PI of -5% and -15%, respectively, and in the ccHRT group decreases of -2% and -19%, respectively, were found. CONCLUSION: Long-term use of 150 mg of raloxifene daily or ccHRT reduces impedance to flow within the uterine artery. This indicates that high-dose raloxifene may exert cardiovascular protection.     

Exercise-induced apoptosis of lymphocytes depends on training status

PURPOSE: To investigate the effect of training status on lymphocyte apoptosis as well as the expression of cell death receptors and ligands after a marathon run, and to compare these data with the alterations after treadmill exercise tests. METHODS: Sixteen volunteers successfully finished the 2002 Münster marathon. Venous blood samples were drawn before and 0, 3, and 24 h after the race. After cell isolation, cell-based apoptosis markers annexin V, Fas receptor, and Fas ligand were measured by flow cytometry. The same parameters were investigated in a group of 10 subjects before, and 0 and 1 h after both an exhaustive (ExT) and a low-intensity (LoT) treadmill test. RESULTS: The percentage of apoptotic cells after the marathon changed in a biphasic manner. An early increase 3 h after the run was followed by a significant decrease 1 d later. Interestingly, the increase in apoptotic cells was not observed in highly trained athletes, whereas it was significantly more pronounced in badly trained athletes. ExT induced a lymphocyte apoptosis similar to the marathon, whereas no change in apoptosis was observed after the LoT. Both Fas receptor and ligand were increased after the marathon with different kinetics. Whereas the Fas receptor peaked at 1 h, Fas ligand was increased 3 h after the run. After the treadmill tests Fas receptor expression was enhanced in both groups, whereas Fas ligand increased only after the ExT. CONCLUSIONS: Endurance exercise like a marathon is able to induce apoptosis in lymphocytes. Thereby, apoptosis sensitivity seems to be related to training status in an inverse relationship. The increased expression levels of death receptors and ligands might indicate the high apoptosis inducing potential of this type of exercise.     

Decoupling of intracellular calcium signaling in granulocytes after exhaustive exercise

There is growing evidence that exhaustive exercise can induce a suppression of the innate immune functions. Most studies so far describe exercise induced changes in cell counts or functional responses while information regarding intracellular signal transduction parameters is lacking. Therefore in the present study we investigated in granulocytes the regulation of intracellular calcium ([Ca2+]i) which is an important intracellular second messenger. Healthy volunteers underwent a treadmill exercise test at 80% of their maximal oxygen uptake until exhaustion. Granulocytes were separated before and 1 hour after the test. [Ca2+]i was analyzed spectrophotometrically using the Ca2+ sensitive fluorescent dye Fura-2, while the oxidative burst and phagocytosis were measured by flow cytometry. While resting [Ca2+]i levels were unchanged, the Ca2+ transient induced N-formyl-methionyl-leucyl phenylalanine (fMLP) and platelet activating factor (PAF) were enhanced 1 hour after the test compared to pre-exercise values although fMLP receptor density did not change. In contrast, oxidative burst and phagocytosis evoked by fMLP and phorbol-myristate-acetate (PMA) were decreased after exercise. Together, our data support the view that exhaustive exercise affects regulation of Ca2+ signaling in granulocytes. The potentiation of Ca2+ signals is not accompanied by an enhancement of cellular functional parameters suggesting a blockade in intracellular signalling pathways.     

Time course of budding and maturation of R-MuLV-ts29 studied by electron microscopy

A temperature-sensitive mutant of Rauscher murine leukemia virus, is 29 was used to estimate the minimal time to complete budding and the time needed for morphological maturation at 31°. It was found that budding can be completed in 2 min. The first mature forms were seen 20–30 min after shiftdown from 39 to 31°.