The novel Mechanical Ventilator Milano for the COVID-19 pandemic

This paper presents the Mechanical Ventilator Milano (MVM), a novel intensive therapy mechanical ventilator designed for rapid, large-scale, low-cost production for the COVID-19 pandemic. Free of moving mechanical parts and requiring only a source of compressed oxygen and medical air to operate, the MVM is designed to support the long-term invasive ventilation often required for COVID-19 patients and operates in pressure-regulated ventilation modes, which minimize the risk of furthering lung trauma. The MVM was extensively tested against ISO standards in the laboratory using a breathing simulator, with good agreement between input and measured breathing parameters and performing correctly in response to fault conditions and stability tests. The MVM has obtained Emergency Use Authorization by U.S. Food and Drug Administration (FDA) for use in healthcare settings during the COVID-19 pandemic and Health Canada Medical Device Authorization for Importation or Sale, under Interim Order for Use in Relation to COVID-19. Following these certifications, mass production is ongoing and distribution is under way in several countries. The MVM was designed, tested, prepared for certification, and mass produced in the space of a few months by a unique collaboration of respiratory healthcare professionals and experimental physicists, working with industrial partners, and is an excellent ventilator candidate for this pandemic anywhere in the world.

Ultrasonographic evaluation of placental cord insertion at different gestational ages in low-risk singleton pregnancies: a predictive algorithm

OBJECTIVE

To evaluate the accuracy of ultrasound in visualizing placental cord insertion (PCI) at different gestational ages in order to recommend the most feasible period during pregnancy to identify it. Secondary aim was to propose a predictive algorithm for PCI visualization.

METHODS

We performed a single-center, prospective cohort study. We enrolled patients with singleton low-risk pregnancies who underwent fetal ultrasound scan at different gestational ages. We excluded patients with body mass index of 30 Kg/m2 or more, uterine fibroids larger than 5 cm, high-risk pregnancies, fetal weight lower than < 10° percentile or higher than > 90° percentile, increased ("deep pocket" > 80 mm) or decreased ("deep pocket" < 20 mm) amniotic fluid.

RESULTS

Among the 468 recruited patients, the visualization of PCI was not possible in 5.77% of the cases. Furthermore, we showed that PCI visualization was lower as the gestational age increased (p = 0.049) and more difficult in case of posterior placenta (p = 0.001).

CONCLUSIONS

PCI should be evaluated in the first trimester or as early as possible during the second trimester. Moreover, we propose a feasible model to predict the possibility of PCI visualization according to gestational age and uterine site of implantation.

Otorrhagia and Nosebleed as first signs of Intravascular Absorption Syndrome During Hysteroscopy: From Bench to Bedside

Hysteroscopic surgery is indicated for the treatment of several intrauterine diseases. The surgeon needs to be aware of, and know how to prevent, possible complications related to these procedures. In the case of operative hysteroscopy, the systemic effects of low-viscosity fluid uptake must be considered in order to prevent the complications in the patient. We report on two unusual clinical signs of intravascular absorption syndrome (IAS) that developed during an operative hysteroscopy with glycine 1.5% as the fluid of distension. Based on our experience, we recommend that practitioners reduce operating times, monitor fluid balances, check electrolytes and kinetic heart rates, and monitor for symptoms including otorrhagia and nosebleed, in order to identify and possibly prevent IAS due to an overload of low-viscosity fluids.

The microRNA-26a target E2F7 sustains cell proliferation and inhibits monocytic differentiation of acute myeloid leukemia cells

Blocks in genetic programs required for terminal myeloid differentiation and aberrant proliferation characterize acute myeloid leukemia (AML) cells. 1,25-Dihydroxy-vitamin D3 (VitD3) arrests proliferation of AML cells and induces their differentiation into mature monocytes. In a previous study, we showed that miR-26a was induced upon VitD3-mediated monocytic differentiation. Here, we identify E2F7 as a novel target of miR-26a. We show that E2F7 significantly promotes cell cycle progression and inhibits monocytic differentiation of AML cells. We also demonstrate that E2F7 binds the cyclin-dependent kinase inhibitor p21^CIP1/WAF1 (cyclin-dependent kinase inhibitor 1A) promoter repressing its expression. Moreover, interfering with E2F7 expression results in inhibition of c-Myc (v-myc myelocytomatosis viral oncogene homolog) transcriptional activity. This leads to the downregulation of c-Myc transcriptional target miR-17-92 cluster, whose expression has a well-defined role in contributing to block monocytic differentiation and sustain AML cell proliferation. Finally, we show that the expression of E2F7 is upregulated in primary blasts from AML patients. Thus, these findings indicate that the newly identified miR-26a target E2F7 might have an important role in monocytic differentiation and leukemogenesis.

HIV-1 viral DNA is present in ejaculated abnormal spermatozoa of seropositive subjects

BACKGROUND

Semen is the major vehicle for HIV-1 infection as it contains free and cell-associated virions and infected cells. However, the presence of HIV-1 in spermatozoa has been a matter of debate, since the sperm cell fraction may contain somatic infected cells that jeopardize the attribution of the detected virus to the spermatozoa.

METHODS

Spermatozoa from 12 HIV-1 seropositive subjects were purified by multilayered Percoll gradient followed by osmotic shock. Residual presence of non-seminal cells (NCS) in purified spermatozoa, was then evaluated by cytometric and molecular analysis. HIV-1 DNA was revealed by nested PCR and in situ PCR after sperm chromatin decondensation. DNA-fragmented ejaculated spermatozoa in semen of infected subjects were detected by terminal deoxynucleotidyl transferase-mediated dUDP nick-end labeling (TUNEL) analysis.

RESULTS

Purification procedure adopted allowed complete removal of NCS. On purified sperm cells, HIV-1 DNA was detected in 5 out of 12 subjects by nested-PCR. On crude semen of 10 out of 12 subjects, HIV-1 DNA was in situ detected in a small percentage of abnormal spermatozoa with a wide range of structural alterations. TUNEL analysis revealed an increased percentage of DNA-fragmented ejaculated spermatozoa in semen of infected subjects.

CONCLUSIONS

We report molecular evidence demonstrating that HIV-1 infected subjects can ejaculate small amounts of HIV-1 DNA-positive abnormal spermatozoa. Their possible role in HIV-1 sexual transmission remains to be clarified.

Bisperoxovanadium, a phospho-tyrosine phosphatase inhibitor, reprograms myogenic cells to acquire a pluripotent, circulating phenotype

Satellite cells are the main source of myogenic progenitors in postnatal skeletal muscle, but their use in cell therapy for muscle disorders is limited because these cells cannot be delivered through circulation and they are rapidly exhausted in severe myopathies. The search for alternative donor cells is ongoing, but none of the candidates so far show all the features required for successful colonization and repair of diseased muscle. In this study, we show that bisperoxovanadium, a phospho-tyrosine phosphatase inhibitor, induces myogenic cells to acquire a gene expression profile and a differentiation potential consistent with the phenotype of a circulating precursors, while maintaining their myogenic potential. These effects are mediated, at least in part, by NF-kappaB activation through the Tyr42-IkappaB-alpha phosphorylation, as shown by the expression of the dominant negative mutant form of the p50 NF-kappaB subunit. Moreover, when bisperoxovanadium-treated cells are injected into the femoral artery of alpha-sarcoglican null dystrophic mice, they are able to circulate and to reach muscle tissue; importantly, they contribute to muscle regeneration, as shown by the expression of alpha-sarcoglican in some fibers. Our observations indicate that bisperoxovanadium, or similar compounds, may prove very valuable to obtain and to expand, from committed cells, multipotent cell populations suitable for gene-cell therapy applications and may help to understand the molecular basis of genome reprogramming and "stem-ness."

Prognostic value of umbilical-middle cerebral artery pulsatility index ratio in fetuses with growth restriction

OBJECTIVE

To study the utility of Doppler velocimetry and computerized cardiotocography in the management of intrauterine growth restriction and prediction of neonatal outcome.

PATIENTS AND METHODS

Seventy-two pregnant women with fetuses showing growth restriction and delivered within 48 h of their last Doppler velocimetry evaluation. The last computerized cardiotocographic trace from these fetuses was used for statistical analysis, and the last trace from the healthy fetuses of 93 consecutive women undergoing cesarean section was used as control. Umbilical artery pulsatility index (UA PI), middle cerebral artery pulsatility index (MCA PI), UA PI/MCA PI ratio, and uterine artery resistance index (Ut RI) were assessed.

RESULTS

Among women with growth-restricted fetuses, all parameters were significantly higher in those who had hypertension; and in those who had diabetes, only the UA PI/MCA ratio was significantly higher. Umbilical artery PI values and the UA PI/MCA ratio were higher in those who had a nonreassuring result to computerized nonstress test immediately before delivery. A multiple logistic analysis showed that the UA PI/MCA ratio was the only Doppler velocimetry parameter predicting cardiotocographic nonreactivity; furthermore, the predictivity of extended newborn hospitalization (longer than 15 days) was verified, with a sensitivity of 56% and a specificity of 92% when the ratio was higher than 1.26.

CONCLUSION

The MCA PI of fetuses with growth restriction should be assessed. The UA PI/MCA ratio is predictive of a nonreactive computerized cardiotocography trace and of prolonged neonatal hospitalization.

Presence of membrane and soluble forms of Fas ligand and of matrilysin (MMP-7) activity in normal and abnormal human semen

BACKGROUND

The aim of this study is to shed some light on the role of the Fas system in human semen, by investigating whether there is an association between the expression of the molecules regulating the Fas system [membrane-bound Fas ligand (mFasL), soluble Fas ligand (sFasL) and matrilysin, the metalloprotease cleaving mFasL to sFasL] and sperm parameters.

METHODS

We investigated, by flow cytometric analysis, the presence of FasL on spermatozoa from normozoospermic and teratozoospermic subjects and, by western blot, the presence of sFasL and matrilysin in the seminal plasma of the same samples as well as on samples from azoospermic subjects. The enzymatic activity of matrilysin was examined by gel zymography.

RESULTS

We observed that sperm cells expressed mFasL in 22% of normozoospermic men, whereas it was absent from spermatozoa from teratozoospermic patients. Higher levels of sFasL and augmented enzymatic activity of matrilysin were found in azoospermic samples.

CONCLUSIONS

The presence of mFasL on sperm from normozoospermic men and its absence in pathological samples emphasize the role of the Fas system in human semen. Moreover, the presence of both sFasL and matrilysin in seminal plasma implies a fine regulation of the function of the Fas system and, consequently, of the apoptotic process in the human genital tract.

FLIP is expressed in mouse testis and protects germ cells from apoptosis

Apoptosis control in adult testis is crucial to achieve normal spermatogenesis. In this study c-FLIP, an apoptosis-modulating protein, was investigated. In Western blot and immunohistochemical analyses, the 55 KDa c-FLIP long isoform (c-FLIP(L)) was found to be expressed strongly in spermatocytes and spermatids, at low levels in spermatogonia and at almost undetectable levels in Sertoli cells. This expression pattern was confirmed by Northern blot analyses. Further experiments carried out on GC-1spg germ cell line revealed that reducing c-FLIP(L) expression increases Fas-dependent apoptosis. Conversely, restoring c-FLIP(L) expression reduces this response to control levels. Caspase-10 expression was found to match c-FLIP(L) expression pattern; further, caspase-10 activation upon anti-Fas treatment inversely correlated with c-FLIP(L) expression. Finally, TUNEL staining of seminiferous tubules incubated with anti-Fas antibody showed that apoptosis occurs mostly in basally located germ cells, indicating that such cells, expressing low levels of c-FLIP(L), are sensitive to Fas-mediated apoptosis. These data indicate for the first time that c-FLIP(L) might control germ cell apoptosis and caspase activity in the adult testis.

Control and impairment of immune privilege in the testis and in semen

It has long been known that the testis is an immunologically privileged site in the body, and that human seminal plasma possesses a generalized immunosuppressive activity. Multiple factors participate in the establishment of immunotolerance in the testis: the blood-tubular barrier; the local production of immunosuppressive molecules by Sertoli cells; and the Fas system as regulator of immunological homeostasis in both physiological and pathological conditions. Cytokine-induced up-regulation of Fas as well as of integrin ligands, which are known to be specific binding molecules for lymphocytes on the Sertoli cell surface, indicates that the 'nursing' cells of seminiferous epithelium might be important in the impairment of immune privilege, causing autoimmune orchitis. In addition, the soluble form of Fas-ligand protein present in the seminal plasma of infertile patients might suggest a role for this immunomodulatory protein in male infertility. Finally, an understanding of the mechanisms underlying immune privilege in the testis and in semen might help to clarify how cells expressing 'non-self' antigens (such as male gametes) can escape the immune system in both the male and female genital tracts.

Testicular FasL is expressed by sperm cells

The testis is the main source of Fas ligand (FasL) mRNA in rodents; it is generally believed that this molecule, expressed on bordering somatic Sertoli cells, bestows an immune-privileged status in the testis by eliminating infiltrating inflammatory Fas-bearing leukocytes. Our results demonstrate that the attribution of testicular expression of FasL to Sertoli cells is erroneous and that FasL transcription instead occurs in meiotic and postmeiotic germ cells, whereas the protein is only displayed on mature spermatozoa. These findings point to a significant role of the Fas system in the biology of mammalian reproduction.

Histone deacetylase-targeted treatment restores retinoic acid signaling and differentiation in acute myeloid leukemia

Histone deacetylase (HDAC)-dependent transcriptional repression of the retinoic acid (RA)-signaling pathway underlies the differentiation block of acute promyelocytic leukemia. RA treatment relieves transcriptional repression and triggers differentiation of acute promyelocytic leukemia blasts, leading to disease remission. We report that transcriptional repression of RA signaling is a common mechanism in acute myeloid leukemias (AMLs). HDAC inhibitors restored RA-dependent transcriptional activation and triggered terminal differentiation of primary blasts from 23 AML patients. Accordingly, we show that AML1/ETO, the commonest AML-associated fusion protein, is an HDAC-dependent repressor of RA signaling. These findings relate alteration of the RA pathway to myeloid leukemogenesis and underscore the potential of transcriptional/differentiation therapy in AML.

TNF-alpha and IFN-gamma regulate expression and function of the Fas system in the seminiferous epithelium

Sertoli cells have long been considered to be involved in the regulation of the immune response in the testis. More recently, the Fas system has been implicated in the maintenance of the immune privilege in the testis as well as in the regulation of germ cell apoptosis. However, the control of Fas and Fas ligand (FasL) expression in the testis remains unknown. In the present study, we demonstrate that cultured mouse Sertoli cells constitutively express a low level of membrane-bound Fas protein, but not a soluble form of Fas. Sertoli cells stimulated with TNF-alpha and IFN-gamma markedly increase the expression of both soluble and membrane-bound Fas in a dose-dependent manner. The up-regulated membrane-bound Fas protein is functionally active because it induces a significant level of Sertoli cell death in the presence of Neuro-2a FasL+ effector cells. Interestingly, the soluble form of Fas, which is induced by the same cytokines but has an antiapoptotic effect, is also functional. In fact, conditioned media from TNF-alpha-stimulated Sertoli cell cultures inhibit Neuro-2a FasL+-induced cell death. Taken together, our data suggest a possible regulatory role of TNF-alpha and IFN-gamma on Fas-mediated apoptosis in the testis through disruption of the balance between different forms of Fas.

Tumor necrosis factor-alpha induces interleukin-6 production and integrin ligand expression by distinct transduction pathways

Tumor necrosis factor-alpha (TNF-alpha) is a pleiotropic cytokine that elicits a large number of biological effects. However, the intracellular signaling mechanisms that are responsible for the TNF-alpha effects remain largely unknown. We have previously demonstrated that cultured mouse Sertoli cells, after TNF-alpha treatment, increase the surface expression of adhesion molecules such as intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) and interleukin-6 (IL-6) production (Riccioli, A., Filippini, A., De Cesaris, P., Barbacci, E., Stefanini, M., Starace, G., and Ziparo, E. (1995) Proc. Natl. Acad. Sci. U.S.A. 92, 5808-5812). Here, we show that, in cultured Sertoli cells, TNF-alpha activates the mitogen-activated protein kinase pathway (p38, c-Jun N-terminal protein kinase/stress-activated protein kinase, and the p42/p44 mitogen-activated protein kinases) as revealed by an increased phosphorylation of p38, activating transcription factor-2, c-Jun, and Elk-1. Furthermore, our data indicate that the biological effects induced by TNF-alpha in Sertoli cells (enhancement of ICAM-1, VCAM-1, and IL-6 expression) depend on the activation of different signaling pathways. SB203580, a highly specific p38 inhibitor, does not affect ICAM-1 and VCAM-1 expression, but strongly inhibits IL-6 production. Moreover, interferon-gamma, which up-regulates adhesion molecule expression and reduces IL-6 production, does not induce phosphorylation of p38. Our data strongly support the hypothesis that, in response to TNF-alpha, activation of p38 leads to IL-6 production, whereas ICAM-1 and VCAM-1 expression could be induced by activation of the c-Jun N-terminal protein kinase/stress-activated protein kinase pathway.

Rapid purification and properties of human glycodelin (endometrial alpha2-globulin)

The method presented can easily produce milligram amounts of glycodelin from pregnancy endometrium, with a 19% yield. It involves anion-exchange chromatography, gel permeation and chromatofocusing; it results in one stainable band at Mr 28,000 after sodium dodecyl sulphate-polyacrylamide electrophoresis, as well as after immunoblot analysis, performed using an affinity-purified IgG fraction from an antiserum against glycodelin. In spite of this, the corresponding gel isoelectric focusing pattern gives four stainable bands with pI values between 4.55 and 5.2. Western immunoblot analysis of tissue extracts indicates the presence of glycodelin epitopes associated with materials heavier than the native protein. Circular dichroism spectra of the highly purified protein in water solutions indicate a large amount of beta-sheet conformation, whereas those obtained with different proportions of 2-propanol in water, show an increased proportion of alpha-helix conformation.

Efficient one-step direct labelling of recombinant antibodies with technetium-99m

High-affinity bacterially expressed antibody fragments can nowadays be cloned from established hybridomas or, more conveniently, isolated directly from antibody libraries displayed on filamentous phage. Such antibodies can be tagged with C-terminal peptide tags containing one cysteine residue, which represents a convenient functionalisation site for a number of applications, including technetium-99m labelling. Here we describe a simple one-step method for 99mTc labelling of cysteine-tagged recombinant antibodies with more than 50% radionuclide incorporation. The labelled antibodies displayed full retention of immuoreactivity and good stability.

Distribution of SP1, immunoreactivity among different plasma proteins: real molecular heterogeneity or adsorption of SP1-beta to other plasma proteins?

Three SP1-containing factors from pooled term pregnancy sera were subjected to crossed immunoelectrophoresis. New patterns as far as electrophoretic mobilities and shapes of the immunoprecipitates were revealed. The appearance of an additional anodic radioimmunoassayable activity in agarose electrophoresis of mixed SP1-alpha and SP1-beta suggested a binding capacity of SP1-alpha for SP1-beta determinants. In the serum of a single patient at the third trimester of pregnancy we also found two SP1 variants, possessing little radioimmunological reactivity and with crossed immunoelectrophoretic characteristics quite different from those of the 'usual' alpha and beta SP1 forms. These results suggest that, in this particular case, the overall SP1 production cannot be evaluated by competitive binding assay and, that in general, SP1 is a complex antigen the heterogeneity of which can be determined following adsorption of some beta epitopes to another serum protein.

Evagination of smooth muscle cells in the hypoxic pulmonary trunk

Six female Wistar albino rats were exposed to the hypoxia of a simulated altitude of 5500 m, three for a period of one week and three for a month. They developed ultrastructural changes in the pulmonary trunk consisting of evaginations of muscle cells of its media through gaps in the internal elastic lamina to press into the underlying endothelial cells. Such evaginations were usually devoid of myofilaments and organelles. Some appeared so electron-lucent as to be unrecognisable as muscle apart from the unequivocal connection with the parent smooth muscle cells. Elsewhere we have demonstrated that muscular evaginations in normal pulmonary blood vessels are an artefact brought about by collapse of lung tissue and that they can be avoided by distending the lung. Hence in the present investigation, in which the pulmonary trunk was fixed in distension, the evaginations are interpreted as indicating contraction of the muscle cells able to overcome the distending force. We interpret them as evidence of constriction of muscle cells in the media of the pulmonary trunk in response to hypoxia.