Large scale coherent magnetohydrodynamic oscillations in a sunspot.

Although theoretically predicted, the simultaneous excitation of several resonant modes in sunspots has not been observed. Like any harmonic oscillator, a solar magnetic flux tube can support a variety of resonances, which constitute the natural response of the system to external forcing. Apart from a few single low order eigenmodes in small scale magnetic structures, several simultaneous resonant modes were not found in extremely large sunspots. Here we report the detection of the largest-scale coherent oscillations observed in a sunspot, with a spectrum significantly different from the Sun's global acoustic oscillations, incorporating a superposition of many resonant wave modes. Magnetohydrodynamic numerical modeling agrees with the observations. Our findings not only demonstrate the possible excitation of coherent oscillations over spatial scales as large as 30-40 Mm in extreme magnetic flux regions in the solar atmosphere, but also paves the way for their diagnostic applications in other astrophysical contexts.

Caesarean Section in Preventing Stillbirths in Pregnancy Complicated with COVID-19: a Narrative Review.

INTRODUCTION: COVID-19 is a complex syndrome caused by SARS-Cov-2. It mainly affects the respiratory system, but it could cause serious harm during pregnancy. An increase in stillbirths and preterm births has been highlighted by many authors. Although WHO and Royal College of Obstetrics and Gynecology don't recommend elective cesarean section in women with confirmed infection, cesarean sections were performed by many clinicians. This short narrative review aims to analyze pieces of evidence found in literature about the effectiveness of cesarean section in preventing stillbirths in COVID-19 positive mothers. METHODS: Studies included in the present review were retrieved searching MEDLINE (last access August 5th, 2021) with the following keywords: "pregnant woman with covid-19", "Caesarean section", "Ab-dominal Delivery" and "Stillbirth". Studies regarding the mode of delive-ry in pregnant women infected with COVID-19 and neonatal outcomes were included. Studies about biology, anesthesiology and necroscopy were excluded. Filters for "human" and "English" were applied. RESULTS: Searching MEDLINE, 24 references were found. Other 103 articles were found searching bibliography. Two references were excluded after duplicate removal, 77 references after the title screen and 27 after the abstract screen. The final number of references included was 23. Most of the included studies were case reports. Most of them were from China. DISCUSSION: Many authors highlighted the increased risk of fetal death in pregnancies complicated with SARS-Cov-2 infection, but it is not clear if Caesarean Section could reduce this risk. Pieces of evidence show that most clinicians choose to perform an elective cesarean section mostly because of maternal conditions or the fear of possible vertical transmission. Data show that mode of delivery doesn't affect the neonatal outcome and Caesarean Section doesn't reduce the positivity rate among neonates. Different opinions were found about the possible infection of amniotic fluid, cord blood and placenta. The risk of vertical transmission is considered moderate or low by most of the authors. Positivity to SARS-Cov-2 isn't an indication of elective cesarean section by itself, but this mode of delivery should be optioned in patients with other obstetrical indications or with severe conditions due to COVID. The recent increase in stillbirths could be related to the overall deterioration of maternal conditions.

Spectropolarimetric fluctuations in a sunspot chromosphere.

The instrumental advances made in this new era of 4 m class solar telescopes with unmatched spectropolarimetric accuracy and sensitivity will enable the study of chromospheric magnetic fields and their dynamics with unprecedented detail. In this regard, spectropolarimetric diagnostics can provide invaluable insight into magneto-hydrodynamic (MHD) wave processes. MHD waves and, in particular, Alfvénic fluctuations associated with particular wave modes were recently recognized as important mechanisms not only for the heating of the outer layers of the Sun's atmosphere and the acceleration of the solar wind, but also for the elemental abundance anomaly observed in the corona of the Sun and other Sun-like stars (also known as first ionization potential) effect. Here, we take advantage of state-of-the-art and unique spectropolarimetric Interferometric BIdimensional Spectrometer observations to investigate the relation between intensity and circular polarization (CP) fluctuations in a sunspot chromosphere. Our results show a clear link between the intensity and CP fluctuations in a patch which corresponds to a narrow range of magnetic field inclinations. This suggests the presence of Alfvénic perturbations in the sunspot. This article is part of the Theo Murphy meeting issue 'High-resolution wave dynamics in the lower solar atmosphere'.

DNA integrity of canine spermatozoa during chill storage assessed by the sperm chromatin dispersion test using bright-field or fluorescence microscopy.

The objective of this study was to evaluate the effect of chill storage on canine sperm DNA fragmentation assessed by the sperm chromatin dispersion test using bright-field microscopy with Wright solution (sDF-B) or fluorescence microscopy with propidium iodide (sDF-F). The relationship and agreement between the results obtained with both staining methods were analyzed. The values of DNA fragmentation indexes (sDF-F and sDF-B) were compared at each time of chill storage (0, 24, 48, 72, and 96 hours). Additionally, the sperm DNA fragmentation rate (slope) was compared between the methods during chill storage. Good agreement and no significant differences between values obtained with both staining procedures were observed. Finally, the effect of chill storage for up to 96 hours was assessed on sperm motility parameters and DNA fragmentation indexes. Significant differences were found after 48 hours of chill storage, obtaining greater values of fragmented DNA. Progressive sperm motility was lower just after 96 hours of chill storage, and no effect was found in total sperm motility. In conclusion, the Sperm-Halomax kit, developed for canine semen and based on the sperm chromatin dispersion test, can be used accurately under bright-field or fluorescence microscopy to assess the sperm DNA integrity of canine semen during chill storage. The sperm DNA fragmentation index increased after 48 hours of chill storage, thereby detecting sperm damage earlier than other routine sperm parameters, such as sperm motility.

Identification of sperm subpopulations in canine ejaculates: effects of cold storage and egg yolk concentration.

The aim of this study was to evaluate the effects of cold storage and egg yolk concentration on the distribution of spermatozoa within the different subpopulations. Twenty ejaculates from 4 dogs were collected, diluted in either TRIS buffer containing 20% (TEY20) or 10% centrifuged egg yolk (TEY10) and cooled following a conventional protocol. The kinematic parameters of individual spermatozoa were evaluated in fresh ejaculates and after 24 and 72 h of preservation at 5°C. A multivariate clustering procedure separated 54,261 motile spermatozoa into four subpopulations: Subpopulation 1 consisting of poorly active and non-progressive spermatozoa (19.80%), Subpopulation 2 consisting of slow and low-linear spermatozoa (25.21%), Subpopulation 3 consisting of high speed and progressive spermatozoa (23.88%), and Subpopulation 4 consisting of highly active but non-progressive spermatozoa (31.11%). Although, cold storage had a significant (P<0.05) effect on both the frequency distribution of spermatozoa within subpopulations and the motion characteristics of each subpopulation, the sperm subpopulation structure was perfectly maintained after cold storage. Subpopulations 1 and 2 significantly (P<0.001) decreased during cold storage (Subpopulation 1: 26.6, 16.9 and 18.4%; and Subpopulation 2: 33.6, 21.3 and 24.0%, respectively, for fresh, 24 and 72 h post-cooled), whereas Subpopulations 3 and 4 significantly (P<0.05) increased (Subpopulation 3: 16.7, 27.6 and 24.3%, and Subpopulation 4: 23.1, 34.1 and 33.4%, respectively, for fresh, 24 and 72 h post-cooled). Regarding the relative percentage of spermatozoa within each extender, Subpopulation 3 was more frequently observed in TEY20 after both 24 and 72 h of cold storage. Significant correlations (P<0.05) were found between the proportions of spermatozoa assigned to Subpopulation 3 in the fresh ejaculates and those in stored samples after 24 h (r=0.48498). In conclusion, cold storage significantly modified both the specific parameters and the distribution of spermatozoa within subpopulations. These changes did not affect the general motile sperm structure present in dog, which is conserved during cold storage. The analysis of the changes observed in structures of subpopulations also suggests that the TEY20 provide more effective preservation of dog semen during cold storage.

[Complete resection of isolated lung metastasis from breast carcinoma results in a strong increase in survival]. / La resezione completa delle metastasi polmonari isolate in seguito a carcinoma mammario prolunga significativamente la sopravvivenza.

BACKGROUND: Surgical treatment of pulmonary resection for metastatic disease has been proven a valuable therapeutic concept for a variety of neoplasms. Concerning breast cancer, at least 25% of patients develop distant metastases. In spite of increasingly sophisticated palliative therapies, the survival of these patients did not appear significantly prolonged during the last 25 years (19-32 months following diagnosis) and about 95% die from metastatic disease. METHODS: Between 1977 and 1997, three epidemiological comparable groups out of a total of 125 patients of our clinic were treated for isolated pulmonary metastasis following breast cancer. Complete data from 96 patients were retrospectively analyzed following stratification to three groups according their surgical therapy: C, complete resection, 28 patients; I, incomplete resection, 34 patients; N, no resection, 34 patients. RESULTS: Comparison of the three therapy methods concerning stage, histology and receptor levels of the primary tumor, number of metastases and the disease free interval (DFI), as well as adjuvant therapy modalities yielded no significant differences. Mean survival of group C was with 79 months (5-years-survival 80%, 10-years-survival 60%) significantly better compared to groups I and N (p < 0.00002). Mean survival of group I and N was not significantly different (15.5 and 9 months respectively). The DFI had no impact on the survival of group C, but showed a high correlation with the survival of group N (R2 = 0.81). CONCLUSIONS: Routine chest X-ray is necessary in the follow-up of breast cancer patients and if coin lesions occur, thoracic surgeon should be contacted.

Early detection of preeclampsia by determination of platelet aggregability.

Preeclampsia is still a leading cause of maternal and fetal morbidity and mortality. There is evidence for the involvement of platelets. Therefore, we investigated the suitability of corrected whole blood impedance aggregometry as an early predictor of preeclampsia in 71 consecutive, high-risk pregnancies. According to the occurrence of preeclampsia, defined postpartum by an independent investigator, and the stage of pregnancy (early and late, cutoff: 25 weeks of gestation), four study groups were defined. Platelet aggregation data were corrected for the influence of hematocrit and platelet count by a special purpose software package. Women developing preeclampsia showed significantly higher platelet aggregation response compared to controls in early and late pregnancy. In early pregnancy, all women developing preeclampsia had aggregation responses to collagen higher than the highest responses among the controls. Hence, this test had a 100% positive predictive value of subsequent preeclampsia. Despite being significantly increased, platelet aggregability was of minor predictive value in late pregnancy. We conclude that preeclampsia is accompanied by exaggerated platelet aggregability, particularly perceptible early in the course of pregnancy. We propose collagen-induced whole blood platelet aggregation with correction for the influence of hematocrit and platelet count for early detection of preeclampsia.

Changes of platelet surface antigens in patients suffering from abdominal septic shock.

Sepsis and related syndromes account for a high morbidity and mortality caused by the development of multiorgan failure. Pathogenesis of sepsis is complex, involving humoral as well as cellular factors. Since the role of platelets is still undefined in this concern, we investigated CD63, CD62P, CD36, and CD31 expression on platelets of patients in septic shock (n = 18) using a flow cytometric assay in whole blood. Samples were drawn within 24 hours of onset. We found thrombocytopenia accompanied by a significantly higher expression of CD63, CD62P, and CD31 and a significant downregulation of CD36 in comparison to healthy volunteers (n = 18). Changes in CD63 and CD62P expression indicates platelet activation. Because CD62P, CD36, and CD31 mediate interaction of platelets with leukocytes, subendothelial matrix and probably endothelial cells as well as platelet adhesion/aggregation, our findings suggest an involvement of platelets in leukocyte/endothelial cell interaction in septic shock. We suspect that thrombocytopenia is not due to bone marrow depression, but rather is due to consumption of highly activated platelets in the microcirculation. We feel that our observations may offer a rationale for potentially beneficial effects of antiplatelet therapy in sepsis; however, further studies have to evaluate its beneficial impact as well as its potential risk for bleeding complications.

Frequent high expression of bax pro-apoptotic protein in non-small cell lung cancer.

Bax, bcl-2 and their homologues regulate a distal step in an evolutionary very well conserved pathway of apoptotic cell death. It plays a crucial role in the balance between proliferation rate and cell viability. Thus in the last years the attention of the scientific community towards these proteins has remarkably increased, in particular in the oncologic field. We developed an immunohistochemical assay allowing us to evaluate the bax expression in formalin fixed and paraffin embedded lung cancer tissues to investigate bax expression in a cohort of 55 patients affected by non-small cell lung cancer. We detected high expression of bax in 72.7% of our patients. When we statistically analyzed our data we did not find any correlation between bax expression and any clinicopathologic parameters (sex, age, TNM status, tumor grade, histological type). In conclusion, our study shows the frequent overexpression of bax, and this highlights the "apoptotic tendency" of cells during the neoplastic proliferation. But, the role of bax in non-small cell lung cancer pathogenesis still remains unclear and further studies of large numbers of patients, including different stage groups, are needed to better define the involvement of this protein in the complex mechanism of lung carcinogenesis.

Bcl-2 protein expression correlates with nodal status in non small cell lung cancer.

We investigated the immunohistochemical expression of bcl-2 in 55 non small cell lung cancer patients in order to understand if the altered expression of this gene is involved in the development of this kind of neoplasm. Our results showed bcl-2 immunopositivity to be a frequent event in non small cell lung cancer (54.5%) with a higher expression in squamous carcinomas compared to adenocarcinomas (p = .04). In addition, we found a positive correlation between bcl-2 expression levels and nodal status (p < .003). We suggest that bcl-2 immunostaining could be considered as marker of loco-regional invasivity.

[Significant extension of survival by complete resection of isolated lung metastases after breast carcinoma]. / Signifikante Verlängerung des Uberlebens durch komplette Resektion isolierter Lungenmetastasen nach Mammacarcinom.

At least 25% of breast cancer patients develop distant metastases. In spite of increasingly sophisticated palliative therapies, the survival time of patients with metastasis did not appear to be significantly prolonged during the last 25 years (19-32 months following diagnosis) and 95% of them die from metastatic disease. Therefore, it seems appropriate that the therapeutic risk/benefit ratio and impact on quality of life should be reassessed when asymptomatic patients are treated. Surgical treatment and pulmonary resection for metastatic disease has been proven a valuable therapeutic concept for a variety of malignancies. Three epidemiologically comparable collectives out of a total of 125 patients from our clinic were treated for isolated pulmonary metastasis following breast cancer (observation period: 1977-1997). Complete data sets could be established for 96 patients and were retrospectively analyzed following stratification into three groups according to their surgical therapy. Twenty-eight patients underwent complete resection (K), 34 had incomplete resections (I) and 34 had no surgical intervention for lung metastases (N). Comparison of the three therapy arms concerning stage, histology and receptor levels of the primary tumor, number of metastases, and the disease-free interval yielded no significant differences between groups K, I and N. Patients after complete resection of isolated lung metastases (group K) had a mean survival of 79 months (5-year survival 80%, 10-year survival 60%). This was significantly better than groups I and N (P < 0.00002). The mean survival of groups I and N was not significantly different (15.5 and 9 months respectively). The disease-free interval after operation of the primary tumor had no impact on the survival of group K, but showed a high correlation with the survival of group N (R2 = 0.81). Complete resection of isolated pulmonary metastases from carcinoma of the breast results in marked prolongation of survival with a low morbidity rate. Hence, routine chest X-ray should be considered an indispensable part of the oncological aftercare in breast cancer patients.

Prognostic role of proliferating cell nuclear antigen in lung cancer: an immunohistochemical analysis.

Proliferating cell nuclear antigen (PCNA) is a 36 kDa protein acting as a subunit of DNA polymerase delta, and is therefore associated with DNA replication. Its involvement in DNA excision repair after DNA sub-lethal damage has been reported. We assessed the immunohistochemical expression of PCNA in 94 lung cancer specimens in order to evaluate its potential relationship with clinical history and the outcome of the evaluated patients. We found PCNA protein expressed in all the evaluated neoplastic specimens, but with different expression levels. In addition, our results showed a subgroup of patients (high expressors) having a statistically significant worse outcome compared to the other two groups of patients, independently of' any other clinico-pathological feature. In conclusion, our data highlight the central role of PCNA and estimation of the proliferation rate in the prediction of the prognosis of lung cancer patients.

Variable platelet response to low-dose ASA and the risk of limb deterioration in patients submitted to peripheral arterial angioplasty.

A group of 100 patients with intermittent claudication (70 male, 30 female), treated with I00 mg ASA per day, were followed over 18 months after elective percutaneous balloon angioplasty. Platelet function was monitored over a period of 12 months by corrected whole blood aggregometry (CWBA). Upon stimulation by arachidonic acid (AA), adenosine diphosphate (ADP) and collagen, CWBA-results were obtained by an electronic acquisition and evaluation system correcting for hematocrit and platelet count of the blood sample. All patients showed a completely inhibited platelet response to AA stimulation. Comparison of the CWBA-results with clinical parameters revealed that reocclusions at the site of angioplasty occurred exclusively in male patients for which CWBA failed to prove an inhibition of aggregation upon both agonists, ADP and collagen, and for these patients the risk of complication is at least 87% higher (p = 0.0093). Only 40% of male patients show the expected effect of ASA on in vitro platelet aggregation at any given point in time and CWBA is capable of predicting those male patients which are at an elevated risk of reocclusion following peripheral angioplasty.