A qualitative study of reinforcement workers' perceptions and experiences of working in intensive care during the COVID-19 pandemic: A PsyCOVID-ICU substudy.

Purpose: During the COVID pandemic, many hospitals had to mobilize reinforcement healthcare workers, especially in intensive care (ICUs). We investigated the perceptions and experiences of reinforcement workers deployed to ICUs, and the impact of deployment on their personal and professional lives.

Methods: For this qualitative study, a random sample of 30 reinforcement workers was drawn from 4 centres participating in the larger PsyCOVID-ICU study.

[Animals used in therapy for the wellbeing of elderly people].

Visits by dogs to elderly people in nursing homes have shown that animals can produce unexpected and positive reactions. This led to the idea of using a retrained guide dog for the blind in therapy workshops, with patients suffering from dementia. Setting up such a project is possible and produces interesting results.

Gene transfer into canine myoblasts.

We have developed and characterized cultures of healthy and dystrophic canine myoblasts for the evaluation of various gene transfer protocols. The number of desmin-positive myoblasts was elevated (>>80%) in cultures of myoblasts obtained from different muscle territories, the diaphragm muscle giving rise to the purest cultures. Myoblasts from dogs turned out to be a very convenient source of well transfectable and transducible cells.

Immune rejection of human dystrophin following intramuscular injections of naked DNA in mdx mice.

Intramuscular administration of plasmid expressing full-length human dystrophin in dystrophin-deficient adult mdx mice resulted in humoral and weak specific T cell responses against the human dystrophin protein. Following plasmid injection, human dystrophin was detected in the injected muscles at 7 days, but decreased thereafter. Anti-dystrophin antibodies were found 21 days following plasmid injection, which coincided with transient myositis.

Solvoplex: a new type of synthetic vector for intrapulmonary gene delivery.

A novel type of synthetic vector, termed solvoplex, is described that can greatly enhance gene expression in lung after intrapulmonary delivery. Solvoplexes consist of plasmid DNA and organic solvents. Several organic solvents were analyzed, and luciferase reporter gene expression was observed after intrapulmonary delivery of solvoplexes containing DPSO (di-n-propylsulfoxide), TMU (tetramethylurea), or BMSO (butylmethylsulfoxide).

Effect of liposome-encapsulated clodronate pretreatment on synthetic vector-mediated gene expression in mice.

One of the main limitations for the use of synthetic vectors in gene therapy is their relatively low in vivo efficiency when compared with viral vectors. Here, we describe a pretreatment protocol with liposome-encapsulated clodronate in mice by which gene expression levels of a luciferase reporter gene could be increased up to nine-fold in the lung, after intravenous (i.v.

In vitro and in vivo effects of glucocorticoids on gene transfer to skeletal muscle.

As a pharmacological approach to potentially improve gene transfer efficiency into skeletal muscle cells, glucocorticoids were shown here to allow efficient transfection of cultured and mouse human myoblasts, human pulmonary A549 cells, but not dog myoblasts, independently of the transfection protocol, the reporter gene and the transcription promoter employed. Transduction with adenovirus was also increased by dexamethasone. Pretreatment of cells 48 h prior to transfection was most effective and was shown to be concentration-dependent.

Transfection of myoblasts in primary culture with isomeric cationic cholesterol derivatives.

Transfection of satellite cells from dog muscle (myoblasts) in primary culture has been optimized with respect to the position of the cholesteryl moiety along the polyamine chain of spermidine or spermine. Spermidine or spermine were derivatized with cholesterylchloroformate giving rise to three isomers in the case of spermidine and two isomers for spermine that were separated by reversed-phase high-performance liquid chromatography (rp-HPLC). The position of the cholesteryl moiety was assigned by 13C-NMR and coelution with synthetic isomers of defined structure.

Aerosol administration of a recombinant adenovirus expressing CFTR to cystic fibrosis patients: a phase I clinical trial.

Ad CFTR, a replication-deficient adenovirus expressing the human cystic fibrosis transmembrane conductance regulator (CFTR), was administered by aerosolization in a single escalating dose to three pairs (cohorts) of cystic fibrosis (CF) patients. Buffer only was administered to the nose and lungs 9-14 days before nasal instillation of virus followed the day after by aerosolization of Ad CFTR to the lung. Nasal doses (defined in terms of viral plaque forming units, pfu) were 10(5), 10(7), and 4 x 10(8), whereas aerosolized doses were 10(7), 10(8), 5.

[Aerosol administration of a replication defective recombinant adenovirus expressing normal human cDNA-CFTR in the respiratory tractus in patients with cystic fibrosis].

At present it is conceivable to think that gene therapy represents a way to treat or even prevent the respiratory manifestations of cystic fibrosis. Consistent to such a concept, there is sufficient evidence that Ad-CFTR, a recombinant replication-deficient adenovirus expressing the human cystic fibrosis transmembrane conductance regulator cDNA, can vectorize the expression of a functional CFTR (cystic fibrosis transmembrane conductance regulator) to the nasal and airway epithelia. The clinical protocol was designed to assess the safety of single escalating doses of a replication defective adenovirus expressing the cystic fibrosis transmembrane conductance regulator gene (Ad-CFTR) when administered to the tracheobronchial portion of the airways and whether biological efficacy of CFTR delivery could be demonstrated.

A 17.6 kbp region located upstream of the rabbit WAP gene directs high level expression of a functional human protein variant in transgenic mouse milk.

We have investigated whether DNA regions present in the rabbit whey acidic protein (WAP) promoter/5' flanking sequence could potentially confer, in vivo, high level expression of reporter genes. Transgenic mice were generated expressing a variant of human alpha 1-antitrypsin, which has inhibitory activity against plasma kallikrein under the control of a 17.6 kbp DNA fragment located upstream of the rabbit WAP gene.

The promoter of the human cystic fibrosis transmembrane conductance regulator gene directing SV40 T antigen expression induces malignant proliferation of ependymal cells in transgenic mice.

Transgenic mice bearing a human cystic fibrosis transmembrane conductance regulator (CFTR) promoter-SV40 T antigen fusion transgene were generated in order to localize in vivo the potential oncogenesis linked to the tissue-specific activity of the promoter for the CFTR gene. Surprisingly, the only site of tumors resulting from expression of the reporter onc gene was ependymal cells lining the brain ventricles. SV40 T antigen expression in these cells led to a consistent pathology in the first weeks of age: ependymoma and consequent hydrocephaly.

Novel cell lines derived from transgenic mice expressing recombinant human proteins. Transgenic hepatoma-derived cell lines.

We have used transgenic mouse technology to establish immortalized hepatoma cell lines stably secreting heterologous proteins, such as human alpha 1-antitrypsin and human factor IX. Hepatocyte-specific regulatory DNA sequences were used to target both the expression of an onc gene and the gene coding for the human protein to the liver of transgenic mice which eventually developed hepatocellular carcinomas. Tumour cells were subsequently established as permanent cell lines, which maintained a differentiated phenotype under specific culture conditions, being capable of producing biologically active and correctly processed human alpha 1-antitrypsin and factor IX.

Characterization of trans-immortalized hepatic cell lines established from transgenic mice.

Hepato-specific regulatory (promoter/enhancer) DNA sequences were used for targeting the expression of onc genes, such as murine c-myc and Simian Virus 40 T Antigen, to hepatocytes of transgenic mice which subsequently developed hepatocellular carcinomas after a variable period of time (depending on the type of onc gene employed). Several trans-immortalized cell lines were established and compared with respect to the expression of adult hepatic markers and response to growth factors. Despite the morphological differences observed between trans-hepatomas, owing to the expression of the two different onc genes, all tumor-derived cell lines behaved in a comparable fashion during long-term culture displaying an adult hepatic phenotype for at least 40 passages.

Characterization of recombinant human factor IX expressed in transgenic mice and in derived trans-immortalized hepatic cell lines.

Transgenic mice were generated in which 5 kb of the 5' flanking promoter region of the human Factor IX (FIX) gene fused to various FIX constructs (gene, minigene and cDNA) were stably integrated in the germ line. Several transgenic mouse lines expressed high circulating levels of active and correctly processed recombinant human FIX. The presence of at least one FIX intron had a positive effect on the expression.

Transforming growth factor type beta 1 modulates the effects of basic fibroblast growth factor on growth and phenotypic expression of rat astroblasts in vitro.

In a search of the growth factors possibly involved in brain ontogenesis we have examined the effects of transforming growth factor beta 1 (TGF-beta 1) on the growth and phenotypic expression of rat astroblasts in primary culture. Along TGF-beta 1 elicited only a slight negative effect on the growth of these cells. However, this factor was found to modulate the mitogenic effects of other growth factors.

Heterologous protein expression by transimmortalized differentiated liver cell lines derived from transgenic mice (hepatomas/alpha 1 antitrypsin/ONC mouse).

A number of therapeutic plasma proteins are synthesized by human hepatocytes. Since many of these proteins undergo liver-specific post-translational modifications which are required for full biological activity, it may therefore be necessary to develop hepatocyte-based expression systems for their production. Using transgenic mice we have developed a transimmortalisation technique for the isolation of differentiated hepatic cell lines, already engineered to secrete human alpha 1 antitrypsin (alpha 1 AT), a plasma protein which is produced mainly in liver cells.

Reactive astrogliosis after basic fibroblast growth factor (bFGF) injection in injured neonatal rat brain.

Reactive gliosis was revealed by immunocytochemistry using antibodies against the glial fibrillary acidic protein (GFAP) after a stab or an electrolytic lesion administered to the cerebral cortex, corpus callosum, striatum, or hippocampus of a 6-day-old rat. The intensity of the gliosis was about the same in the various structures injured and did not change with the delay of 3, 7, or 20 days between the injury and the sacrifice of the animals. When basic fibroblast growth factor (bFGF) was injected in the lesion locus just after the lesion was performed, it resulted (as soon as 3 days after injury) in a strong astrogliosis that was enhanced after a delay of 7 days, the astrocytes in the lesion area exhibiting enlarged cell processes and intense GFAP-positive immunoreactivity.

Primary cultures of astrocytes from different brain areas of newborn rats and effects of basic fibroblast growth factor.

The effects of basic fibroblast growth factor (bFGF) on the morphology and the expression of glial fibrillary acidic protein (GFAP) and glutamine synthetase (GS) in cultured astrocytes prepared from various areas of newborn rat brain was studied. The brain was dissected in two ways, either the telencephalon (area A) and the diencephalon (area B) were dissected out of the brain (without olfactory bulbs, mesencephalon and cerebellum) or the brain was cut transversely into 3 parts (areas 1, 2 and 3). Area 1 (the anterior part) included the frontal cortex, the olfactory nuclei, the neostriatum, the accumbens nucleus and the septum; area 2 (the medial part) included the cortex, hippocampus, amygdale, thalamus and hypothalamus, and area 3 (the posterior part) included the occipital cortex, the posterior part of hippocampus and thalamus and the mamillary bodies.

Effects of acidic and basic fibroblast growth factors on proliferation and maturation of cultured rat oligodendrocytes.

A pure culture of oligodendrocytes has been developed starting from brain hemispheres of newborn rats. Various effects of acidic and basic fibroblast growth factors (FGFs) on the development of oligodendrocytes have been examined and compared. Both factors elicited similar effects, i.

An endogenous lectin found in rat astrocyte cultures has a role in cell adhesion but not in cell proliferation.

The presence of an endogenous cerebellar soluble lectin (CSL) has been demonstrated in cultured rat astrocytes by using immunocytochemical techniques. In these cells, the location of lectin CSL was found intracellularly as well as on the external surface of the plasma membrane of the cell bodies and processes, especially in the zones of contact between cells. This suggested that CSL could have a role in adhesion of astrocytes to sister cells.

Endogenous lectin CSL is present on the membrane of cilia of rat brain ependymal cells.

An endogenous brain lectin, with a great affinity for oligomannosidic glycans, called CSL (for 'cerebellar soluble lectin'), was detected on the surface of the cilia of ependymal cells both in cultures and in vivo. The lectin is not synthesized by the ependymal cells themselves. In vivo it is neither found in cerebrospinal fluid nor in cells of the choroid plexus.

Comparison of the morphological effects of acidic and basic fibroblast growth factors on rat astroblasts in culture.

The effects of acidic and basic fibroblast growth factors (aFGF and bFGF) on the morphology of cultured rat astroblasts and on the expression of glial fibrillary acidic protein (GFAP) were compared. The addition of either aFGF or bFGF affected the morphology of the flat, irregular, polygonal-shaped astroblasts, which formed processes and acquire a fibrous appearance. Appreciable different morphological aspects were observed between aFGF- and bFGF-induced cells, essentially between 11 and 14 days in culture.

Proliferation of rat astrocytes, but not of oligodendrocytes, is stimulated in vitro by protease inhibitors.

Various natural protease inhibitors stimulate the proliferation of rat astrocytes grown in primary culture in the absence of serum. They are inactive on the proliferation of oligodendrocytes. The mean level of stimulation of the astrocyte proliferation elicited by the protease inhibitors is higher when the cells are in the growth phase, at low cell density than when they are quiescent, at high cell density.