A Randomized Trial of Nafamostat for Covid-19

A Randomized Trial of Nafamostat for Covid-19Nafamostat mesylate is a potent in vitro antiviral that inhibits the host transmembrane protease serine 2 enzyme used by SARS-CoV-2 for cell entry. Morpeth et al report the results of an open-label randomized clinical trial of nafamostat for noncritically ill patients with Covid-19.

A multi-site, international laboratory study to assess the performance of penicillin susceptibility testing of Staphylococcus aureus

OBJECTIVES

There is clinical uncertainty over the optimal treatment for penicillin-susceptible Staphylococcus aureus (PSSA) infections. Furthermore, there is concern that phenotypic penicillin susceptibility testing methods are not reliably able to detect some blaZ-positive S. aureus.

METHODS

Nine S. aureus isolates, including six genetically diverse strains harbouring blaZ, were sent in triplicate to 34 participating laboratories from Australia (n = 14), New Zealand (n = 6), Canada (n = 12), Singapore (n = 1) and Israel (n = 1). We used blaZ PCR as the gold standard to assess susceptibility testing performance of CLSI (P10 disc) and EUCAST (P1 disc) methods. Very major errors (VMEs), major error (MEs) and categorical agreement were calculated.

RESULTS

Twenty-two laboratories reported 593 results according to CLSI methodology (P10 disc). Nineteen laboratories reported 513 results according to the EUCAST (P1 disc) method. For CLSI laboratories, the categorical agreement and calculated VME and ME rates were 85% (508/593), 21% (84/396) and 1.5% (3/198), respectively. For EUCAST laboratories, the categorical agreement and calculated VME and ME rates were 93% (475/513), 11% (84/396) and 1% (3/198), respectively. Seven laboratories reported results for both methods, with VME rates of 24% for CLSI and 12% for EUCAST.

CONCLUSIONS

The EUCAST method with a P1 disc resulted in a lower VME rate compared with the CLSI methods with a P10 disc. These results should be considered in the context that among collections of PSSA isolates, as determined by automated MIC testing, less than 10% harbour blaZ. Furthermore, the clinical relevance of phenotypically susceptible, but blaZ-positive S. aureus, remains unclear.

Anticoagulation Strategies in Non-Critically Ill Patients with Covid-19

Anticoagulation in Non-Critically Ill Covid-19 PatientsMcQuilten et al. conducted a randomized clinical trial comparing low-dose, intermediate-dose, low-dose plus aspirin, and therapeutic-dose anticoagulation in patients with Covid-19 of diverse ethnicities in high-, low-, and middle-income countries.

Nuclear exclusion of SMAD2/3 in granulosa cells is associated with primordial follicle activation in the mouse ovary

Maintenance and activation of the limited supply of primordial follicles in the ovary are important determinants of reproductive lifespan. Currently, the molecular programme that maintains the primordial phenotype and the early events associated with follicle activation are not well defined. Here, we have systematically analysed these events using microscopy and detailed image analysis. Using the immature mouse ovary as a model, we demonstrate that the onset of granulosa cell (GC) proliferation results in increased packing density on the oocyte surface and consequent GC cuboidalization. These events precede oocyte growth and nuclear translocation of FOXO3a, a transcription factor important in follicle activation. Immunolabelling of the TGFβ signalling mediators and transcription factors SMAD2/3 revealed a striking expression pattern specific to GCs of small follicles. SMAD2/3 were expressed in the nuclei of primordial GCs but were mostly excluded in early growing follicles. In activated follicles, GC nuclei lacking SMAD2/3 generally expressed Ki67. These findings suggest that the first phenotypic changes during follicle activation are observed in GCs, and that TGFβ signalling is fundamental for regulating GC arrest and the onset of proliferation.

The physiological role of arcuate kisspeptin neurons in the control of reproductive function in female rats

Kisspeptin plays a pivotal role in pubertal onset and reproductive function. In rodents, kisspeptin perikarya are located in 2 major populations: the anteroventral periventricular nucleus and the hypothalamic arcuate nucleus (ARC). These nuclei are believed to play functionally distinct roles in the control of reproduction. The anteroventral periventricular nucleus population is thought to be critical in the generation of the LH surge. However, the physiological role played by the ARC kisspeptin neurons remains to be fully elucidated. We used bilateral stereotactic injection of recombinant adeno-associated virus encoding kisspeptin antisense into the ARC of adult female rats to investigate the physiological role of kisspeptin neurons in this nucleus. Female rats with kisspeptin knockdown in the ARC displayed a significantly reduced number of both regular and complete oestrous cycles and significantly longer cycles over the 100-day period of the study. Further, kisspeptin knockdown in the ARC resulted in a decrease in LH pulse frequency. These data suggest that maintenance of ARC-kisspeptin levels is essential for normal pulsatile LH release and oestrous cyclicity.

Investigations of TGF-β signaling in preantral follicles of female mice reveal differential roles for bone morphogenetic protein 15

Bone morphogenetic protein 15 (BMP15) and growth differentiation factor 9 (GDF9) are 2 closely related TGF-β ligands implicated as key regulators of follicle development and fertility. Animals harboring mutations of these factors often exhibit a blockage in follicle development beyond the primary stage and therefore little is known about the role of these ligands during subsequent (preantral) stages. Preantral follicles isolated from immature mice were cultured with combinations of BMP15, GDF9, and activin receptor-like kinase (ALK) inhibitors. Individually, GDF9 and BMP15 promoted follicle growth during the first 24 hours, whereas BMP15 subsequently (48-72 h) caused follicle shrinkage and atresia with increased granulosa cell apoptosis. Inhibition of ALK6 prevented the BMP15-induced reduction in follicle size and under basal conditions promoted a rapid increase in granulosa cell proliferation, suggesting BMP15 signals through ALK6, which in turn acts to restrain follicle growth. In the presence of GDF9, BMP15 no longer promoted atresia and in fact follicle growth was increased significantly more than with either ligand alone. This cooperative effect was accompanied by differential expression of Id1-3, Smad6-7, and Has2 and was blocked by the same ALK5 inhibitor used to block GDF9 signaling. Immunostaining for SMAD2/3 and SMAD1/5/8, representing the 2 main branches of TGF-β signaling, supported the fact that both canonical pathways have the potential to be active in growing follicles, whereas primordial follicles only express SMAD2/3. Overall results highlight differential effects of the 2 main TGF-β signaling pathways during preantral follicle growth.

Effect of cell shape and packing density on granulosa cell proliferation and formation of multiple layers during early follicle development in the ovary

The postnatal mouse ovary is rich in quiescent and early-growing oocytes, each one surrounded by a layer of somatic granulosa cells (GCs) on a basal lamina. As oocytes start to grow the GCs change shape from flattened to cuboidal, increase their proliferation and form multiple layers, providing a unique model for studying the relationship between cell shape, proliferation and multilayering within the context of two different intercommunicating cell types: somatic and germ cells. Proliferation of GCs was quantified using immunohistochemistry for Ki67 and demonstrated that, unusually, cuboidal cells divided more than flat cells. As a second layer of GCs started to appear, cells on the basal lamina reached maximum packing density and the axes of their mitoses became perpendicular to the basal lamina, resulting in cells dividing inwards to form second and subsequent layers. Proliferation of basal GCs was less than that of inner cells. Ultrastructurally, collagen fibrils outside the basal lamina became more numerous as follicles developed. We propose that the basement membrane and/or theca cells that surround the follicle provide an important confinement for rapidly dividing columnar cells so that they attain maximum packing density, which restricts lateral mitosis and promotes inwardly oriented cell divisions and subsequent multilayering.

Gonadotropin-releasing hormone neuron requirements for puberty, ovulation, and fertility

The absolute requirement for reproduction implies that the hypothalamo-pituitary-gonadal axis, controlling fertility, is an evolutionary robust mechanism. The GnRH neurons of the hypothalamus represent the key cell type within the body dictating fertility. However, the level of functional redundancy within the GnRH neuron population is unknown. As a result of a fortuitous transgene insertion event, GNR23 mice exhibit a marked allele-dependent reduction in GnRH neuron number within their brain. Wild-type mice have approximately 600 GnRH neurons, compared with approximately 200 (34%) and approximately 70 (12%) in GNR23(+/-) and GNR23(-/-) mice, respectively. Using these mice, we examined the minimal GnRH neuron requirements for fertility. Male GNR23(-/-) mice exhibited normal fertility. In contrast, female GNR23(-/-) mice were markedly subfertile, failing to produce normal litters, have estrous cycles, or ovulate. The failure of ovulation resulted from an inability of the few existing GnRH neurons to generate the LH surge. This was not the case, however, for the first cycle at puberty that appeared normal. Together, these observations demonstrate that 12% of the GnRH neuron population is sufficient for pulsatile gonadotropin secretion and puberty onset, whereas between 12 and 34% are required for cyclical control in adult female mice. This indicates that substantial redundancy exists within the GnRH neuronal population and suggests that the great majority of GnRH neurons must be dysfunctional before fertility is affected.

[MARS (Molecular Absorbent Recirculating System) as hepatic extracorporeal care in serious acute liver failure of alcoholic etiology]

Acute liver failure with criteria of seriousness and alcoholic etiology is a picture of worldwide distribution, with an elevated mortality, of approximately 50%, that requires admission to the ICU. Acute serious alcoholic hepatitis is defined by a Maddrey score value > 32 and/or spontaneous encephalopathy. Together with the classical treatment with corticosteroids and nutritional supplements, alcoholic abstinence and others such as anti-TNF therapy, we introduce MARS (Molecular Adsorbent recirculating System) as a extracorporeal liver assistance system with detoxification function, that is presented as a support measure that makes it possible to maintain the patient in good conditions until an organ becomes available or until the functional recovery of the native liver. In our case, MARS has shown some spectacular results and above all, results maintained over time, associated to the rest of the therapeutic measures characteristic of this disease.

Caspase-3, TUNEL and ultrastructural studies of small follicles in adult human ovarian biopsies

BACKGROUND

The aim of this study was to investigate evidence for cell death by apoptosis in small unilaminar ovarian follicles of adult humans.

METHODS

Cortical biopsies from 13 healthy donors were either frozen and protein extracted for western blots or fixed for immunohistochemistry (IH) to localize procaspase-3 and active-caspase-3, to detect DNA fragmentation in situ and undertake routine transmission electron microscopy (TEM).

RESULTS

Blots identified the presence of the inactive pro-form of caspase-3, and IH localized this in all follicles studied. In contrast, the active form of caspase-3, a major effector of apoptosis, was only detected in large antral follicles that also had microscopic signs of atresia. Active caspase-3 was not detected in primordial (n = 87), primary (n = 8) or secondary follicles. The atretic follicles were also the only ovarian structures with positive evidence of DNA fragmentation after terminal deoxynucleotidyl transferase-mediated dUTP nick end-labelling (TUNEL) treatment. Confocal microscopy showed dual labelling for both active caspase-3 and TUNEL in individual granulosa cells in large atretic follicles, but no such labelling was evident in any other follicles. No apoptotic bodies were seen by TEM in sections of 39 small follicles from seven patients.

CONCLUSION

This study found evidence for TUNEL and active caspase-3 only in human ovarian antral follicles.