Identification of natural killer markers associated with fatal outcome in COVID-19 patients

Introduction

Increasing evidence has shown that coronavirus disease 19 (COVID-19) severity is driven by a dysregulated immunological response. Previous studies have demonstrated that natural killer (NK) cell dysfunction underpins severe illness in COVID-19 patients, but have lacked an in-depth analysis of NK cell markers as a driver of death in the most critically ill patients.

Methods

We enrolled 50 non-vaccinated hospitalized patients infected with the initial virus or the alpha variant of SARS-CoV-2 with moderate or severe illness, to evaluate phenotypic and functional features of NK cells.

Results

Here, we show that, consistent with previous studies, evolution NK cells from COVID-19 patients are more activated, with the decreased activation of natural cytotoxicity receptors and impaired cytotoxicity and IFN-γ production, in association with disease regardless of the SARS-CoV-2 strain. Fatality was observed in 6 of 17 patients with severe disease; NK cells from all of these patients displayed a peculiar phenotype of an activated memory-like phenotype associated with massive TNF-α production.

Discussion

These data suggest that fatal COVID-19 infection is driven by an uncoordinated inflammatory response in part mediated by a specific subset of activated NK cells.

Exploring ambivalence toward pregnancy among young Inuit women

Ambivalence toward pregnancy is an important predictor of early pregnancy as documented in diverse Western societies. Inuit women from Nunavik, a northern region of Quebec, Canada, experience a high rate of early pregnancy, yet no study has explored their attitudes toward pregnancy. Grounded in a participatory approach, this study aimed to explore ambivalence toward pregnancy, among other pregnancy-related attitudes, and identify themes underlying ambivalence among young Inuit women from Nunavik. We conducted semi-structured interviews with 15 women aged 16 to 20 years, who became pregnant during the year preceding the interview. We used an inductive approach to analyse the data. Eleven participants were identified as ambivalent toward pregnancy while three were characterised as having a favourable attitude, and one as unfavourable. Four themes related to ambivalence were identified: the value of childbearing/motherhood; the use of contraceptives; the likelihood of becoming pregnant; and the ideal age to become pregnant. A better understanding of young women's attitudes toward pregnancy could contribute to the development of culturally relevant programmes to more effectively support adolescents, pregnant adolescents and young mothers, and to lead to better care.

Plasticity of natural killer cells in pregnant patients infected with SARS-CoV-2 and their neonates during childbirth

The COVID-19 pandemic has occurred due to infection caused by the SARS-CoV-2 coronavirus, which impacts gestation and pregnancy. In SARS-CoV-2 infection, only very rare cases of vertical transmission have been reported, suggesting that fetal immune imprinting due to a maternal infection is probably a result of changes in maternal immunity. Natural killer (NK) cells are the leading maternal immune cells that act as a natural defense system to fight infections. They also play a pivotal role in the establishment and maintenance of pregnancy. While peripheral NK cells display specific features in patients infected with SARS-CoV-2 in the general population, information remains elusive in pregnant mothers and neonates. In the present study, we analyzed the characteristics of NK cells isolated from both neonatal umbilical cord blood and maternal peripheral blood close to the time of delivery. Phenotype and functions were compared in 18 healthy pregnant women and 34 COVID-19 patients during pregnancy within an ongoing infection (PCR⁺; N = 15) or after recovery (IgG⁺PCR⁻; N = 19). The frequency of NK cells from infected women and their neonates was correlated with the production of inflammatory cytokines in the serum. The expression of NKG2A and NKp30, as well as degranulation of NK cells in pregnant women with ongoing infection, were both negatively correlated to estradiol level. Furthermore, NK cells from the neonates born to infected women were significantly decreased and also correlated to estradiol level. This study highlights the relationship between NK cells, inflammation, and estradiol in patients with ongoing infection, providing new insights into the impact of maternal SARS-CoV-2 infection on the neonate.

Saphenous nerve injury after anterior cruciate ligament reconstruction: Reduced numbness area after ligamentoplasty using quadriceps tendon compared with hamstring tendon

PURPOSE

Injury to the infra-patellar branches of the saphenous nerve (IPBSN) is the main neurological complication of anterior cruciate ligament (ACL) reconstruction procedures. Surgical technique using quadriceps tendon (QT) autograft allows a less invasive tibial approach potentially protecting the IPBSN. The aim of this study was to compare the numbness surface of the cutaneous area supplied by the IPBSN after ACL reconstruction using either hamstring tendon (HT) or QT autografts.

METHODS

This was a retrospective comparative cohort study including 51 patients who underwent ACL reconstruction (27 QT and 24 HT) between January 2017 and April 2018. A sensory clinical evaluation was performed on each patient: length of the tibial scar, eventual numbness surface area and the type of sensory disorder were reported. To be considered as an IPBSN lesion, the numbness area had to spread at least one-centimeter away from the scar.

RESULTS

The average follow-up was 15 months. In the HT group, the numbness area surface measured 21.2 ± 19 cm² (0-77) and the scar length was on average 31.3 ± 5.6 mm. In the QT group, the numbness area was reduced to 5 ± 10 cm² (P = .0007) as well as the scar length (13.3 ± 2.8 mm, P < .0001). We counted five (17.8%) and 19 (76%) real IPBSN lesions in the QT and HT groups, respectively (P = .0002). Hypoesthesia was the main sensory disorder observed (87.5%).

CONCLUSION

Numbness area of the cutaneous surface supplied by the IPBSN after ACL reconstruction is reduced using QT autograft compared with HT autograft.

[Management of cardiovascular co-morbidities in young patients with early onset psychosis: State of the art and therapeutic perspectives]

Patients with psychiatric disorders have a decrease in their life expectancy. Excess mortality of patients with schizophrenia was demonstrated by a meta-analysis in the late 1990s and has not decreased for the past 30years. A recent meta-analysis including nearly 250,000 patients with schizophrenia found an average decrease in life expectancy of 14.5years (CI95: 11,2-17,8), more important for men than for women: 15.9 (CI95: 13,8-18,0) vs 13.6 (CI95: 11,4-15,8). A closer look at the somatic comorbidities, including metabolic syndrome, and investigation of causes of death of these patients highlighted already well-known factors, namely late diagnosis and insufficient treatment of physical diseases, side effects of antipsychotics, unhealthy lifestyle (poor diet, smoking, excessive alcohol consumption and lack of exercise), and higher risk of suicide and accident. Concerning ultra-high risk (UHR) patients, a 2016 meta-analysis of 47 studies evaluated the cardiovascular risk factors. They reported a higher prevalence of smoking in UHR (odds ratio 2,3) and a lower level of physical activity associated with a normal BMI (Body Mass Index) compared to the control population. A meta-analysis about patients with a first episode of psychosis (FEP) found reduced total and LDL cholesterol levels and an increased triglyceride level compared to the control population. One study found alteration of the fasting plasmatic levels of glucose and insulin, as well as insulin resistance in FEP patients, compared to controls albeit the HbA1c level was not significantly different. A meta-analysis reported a prevalence of metabolic syndrome of 10 % in FEP or drug naïve patients versus 35 % and 20 % in treated and untreated patients with chronic schizophrenia respectively. Somatic comorbidities usually appear during the first two years of the disease. Some interventions have proven their efficacy in reducing the occurrence of metabolic syndrome and other cardiovascular risk factors. For instance, metformin, a treatment for type 2 diabetes that is allowed from the age of 10, has shown benefits in children and adolescents receiving second-generation antipsychotics in a recent meta-analysis, with a mean weight loss of 3.23kg (IC95 % -5.59 -0.86) after 16 weeks. Dietary-hygienic interventions are also effective in reducing cardiovascular risk. Other interventions such as omega-3 supplementation, vitamin D, N-acetylcysteine, and fasting have not proven to be effective. Comprehensive care programs have been developed to promote somatic care in psychiatric patients, such as the Canadian HeAL (Healthy Active Lives) program. These programs are more effective when proposed from the beginning of the disease and the introduction of antipsychotics. In this review, because there is no French recommendation, we translate a tool for the prescription of metformin and the Canadian recommendations from the HeAL program. Generalization of these programs to all young psychotic patients could improve their life expectancy and reduce the overall mortality. Prevention of cardiovascular risk factors and cardio-metabolic monitoring of treatments must be part of the standard of care in early psychosis. These programs aim at providing patients with the quality of somatic and mental care they are entitled to. This requires the involvement of all stakeholders, including patients and their families but also psychiatrists and other caregivers.

Limited HIV-2 reservoirs in central-memory CD4 T-cells associated to CXCR6 co-receptor expression in attenuated HIV-2 infection

The low pathogenicity and replicative potential of HIV-2 are still poorly understood. We investigated whether HIV-2 reservoirs might follow the peculiar distribution reported in models of attenuated HIV-1/SIV infections, i.e. limited infection of central-memory CD4 T lymphocytes (TCM). Antiretroviral-naive HIV-2 infected individuals from the ANRS-CO5 (12 non-progressors, 2 progressors) were prospectively included. Peripheral blood mononuclear cells (PBMCs) were sorted into monocytes and resting CD4 T-cell subsets (naive [TN], central- [TCM], transitional- [TTM] and effector-memory [TEM]). Reactivation of HIV-2 was tested in 30-day cultures of CD8-depleted PBMCs. HIV-2 DNA was quantified by real-time PCR. Cell surface markers, co-receptors and restriction factors were analyzed by flow-cytometry and multiplex transcriptomic study.

HIV-2 DNA was undetectable in monocytes from all individuals and was quantifiable in TTM from 4 individuals (median: 2.25 log₁₀ copies/10⁶ cells [IQR: 1.99–2.94]) but in TCM from only 1 individual (1.75 log₁₀ copies/10⁶ cells). HIV-2 DNA levels in PBMCs (median: 1.94 log₁₀ copies/10⁶ PBMC [IQR = 1.53–2.13]) positively correlated with those in TTM (r = 0.66, p = 0.01) but not TCM. HIV-2 reactivation was observed in the cells from only 3 individuals. The CCR5 co-receptor was distributed similarly in cell populations from individuals and donors. TCM had a lower expression of CXCR6 transcripts (p = 0.002) than TTM confirmed by FACS analysis, and a higher expression of TRIM5 transcripts (p = 0.004). Thus the low HIV-2 reservoirs differ from HIV-1 reservoirs by the lack of monocytic infection and a limited infection of TCM associated to a lower expression of a potential alternative HIV-2 co-receptor, CXCR6 and a higher expression of a restriction factor, TRIM5. These findings shed new light on the low pathogenicity of HIV-2 infection suggesting mechanisms close to those reported in other models of attenuated HIV/SIV infection models.

HIV-2 induces a still poorly understood attenuated infection compared to HIV-1. We investigated whether this infection might follow peculiarities associated with other models of attenuated HIV-1/SIV infection, i.e. a limited infection of a key subset of memory CD4 T lymphocytes, the central-memory ones (TCM). Thus we studied the infection rates in peripheral blood cells from 14 untreated HIV-2 infected individuals from the ANRS-CO5 HIV-2 cohort, and found; 1) a lack of infection of monocytes, 2) extremely low infection in central-memory CD4+ T lymphocytes while HIV-2 predominated in the transitional-memory cells, 3) a poor replicative capacity of HIV-2 in individuals cells. We then investigated the cellular expression of a hundred-host genes potentially involved in HIV-2 control. We found in individuals’ TCM cells, compared to TTM ones, a lower expression of CXCR6, a potentially alternative co-receptor of HIV-2 but not of HIV-1, and a higher expression of TRIM5α, a restriction factor to which HIV-2 is more sensitive than HIV-1. Altogether our findings shed new light on the low pathogenicity of HIV-2 suggesting mechanisms close to those reported in other models of attenuated HIV/SIV infection models.

Meniscoplasty for lateral discoid meniscus tears: Long-term results of 14 cases

INTRODUCTION

Discoid lateral meniscus lesions are relatively rare. The objective of this study was to determine the long-term results of 14 cases of discoid lateral meniscus tears treated by arthroscopic meniscoplasty between July 1991 and May 2009, and to assess the development of osteoarthritis in the lateral compartment.

METHODS

The series consisted of 10 patients (14 knees): 3 girls under the age of 15, 3 men and 4 women aged from 16 to 47 years (mean age: 31.4±11.1 years). The main reason for consultation was pain in 10 cases, locking in 2 cases and pain associated with locking in 2 cases. The diagnosis was confirmed preoperatively by MRI in 10 cases, CT-arthrography in 1 case and arthrography in 3 cases. The indication for surgery was made because of a symptomatic discoid lateral meniscus. All cases were treated by arthroscopic meniscal reshaping. Functional results were evaluated using the Lysholm-Tegner, IKDC, KOOS and satisfaction scores. Radiological results were evaluated based on the modified Alhbäck classification for osteoarthritic (OA) changes.

RESULTS

No complications were found. Two patients were lost to follow-up. The remaining eight patients (12 knees) were reviewed at a mean of 157.5±72.1 months (61-276). The mean Lysholm-Tegner score was 88.9±10.6 points (67-100), the mean KOOS was 92.4±9.5 (65-100) and the mean IKDC score was 85.4±16.5 points (65-100). All eight of the reviewed patients were satisfied or very satisfied with the result. Radiological analysis found that five knees had no signs of OA, five knees had stage 1, one had stage 2 and one had stage 3. At last follow-up, no patient had been reoperated.

CONCLUSION

Meniscoplasty of discoid lateral meniscus tears leads to excellent long-term functional results despite signs of osteoarthritic changes in the lateral compartment of the knee.

LEVEL OF EVIDENCE

IV (retrospective study).

V-erbA generates ribosomes devoid of RPL11 and regulates translational activity in avian erythroid progenitors

The v-erbA oncogene transforms chicken erythrocytic progenitors (T2EC) by blocking their differentiation and freezing them in a state of self-renewal. Transcriptomes of T2EC, expressing either v-erbA or a non-transforming form of v-erbA (S61G), were compared using serial analysis of gene expression and some, but not all, mRNA-encoding ribosomal proteins were seen to be affected by v-erbA. These results suggest that this oncogene could modulate the composition of ribosomes. In the present study, we demonstrate, using two-dimensional difference in gel electrophoresis, that v-erbA-expressing cells have a lower amount of RPL11 associated with the ribosomes. The presence of ribosomes devoid of RPL11 in v-erbA-expressing cells was further confirmed by immunoprecipitation. In order to assess the possible impact of these specialized ribosomes on the translational activity, we analyzed proteomes of either v-erbA or S61G-expressing cells using 2D/mass spectrometry, and identified nine proteins present in differing amounts within these cells. Among these proteins, we focused on HSP70 because of its involvement in erythroid differentiation. Our results indicate that, in v-erbA-expressing cells, hsp70 is not only transcribed but also translated more efficiently, as shown by polyribosome fractionation experiments. We demonstrate here, for the first time, the existence of ribosomes with different protein components, notably ribosomes devoid of RPL11, and a regulation of mRNA translation depending on v-erbA oncogene expression.

Characterisation of a cluster of TRIM-B30.2 genes in the chicken MHC B locus

We have identified and characterised a cluster of six TRIM-B30.2 genes flanking the chicken BF/BL region of the B complex. The TRIM-B30.2 proteins are a subgroup of the TRIM protein family containing the tripartite motif (TRIM), consisting of a RING domain, a B-box and a coiled coil region, and a B30.2-like domain. In humans, a cluster of seven TRIM-B30.2 genes has been characterised within the MHC on Chromosome 6p21.33. Among the six chicken TRIM-B30.2 genes two are orthologous to those of the human MHC, and two (TRIM41 and TRIM7) are orthologous to human genes located on Chromosome 5. In humans, these last two genes are adjacent to GNB2L1, a guanine nucleotide-binding protein gene, the ortholog of the chicken c12.3 gene situated in the vicinity of the TRIM-B30.2 genes. This suggests that breakpoints specific to mammals have occurred and led to the remodelling of their MHC structure. In terms of structure, like their mammalian counterparts, each chicken gene consists of five coding exons; exon 1 encodes the RING domain and the B-box, exons 2, 3 and 4 form the coiled-coil region, and the last exon represents the B30.2-like domain. Phylogenetic analysis led us to assume that this extended BF/BL region may be similar to the human extended class I region, because it contains a cluster of BG genes sharing an Ig-V like domain with the BTN genes (Henry et al. 1997a) and six TRIM-B30.2 genes containing the B30.2-like domain, shared with the TRIM-B30.2 members and the BTN genes.

Diversity of Mhc class I and IIB genes in house sparrows (Passer domesticus)

In order to understand the expression and evolution of host resistance to pathogens, we need to examine the links between genetic variability at the major histocompatibility complex ( Mhc), phenotypic expression of the immune response and parasite resistance in natural populations. To do so, we characterized the Mhc class I and IIB genes of house sparrows with the goal of designing a PCR-based genotyping method for the Mhc genes using denaturing gradient gel electrophoresis (DGGE). The incredible success of house sparrows in colonizing habitats worldwide allows us to assess the importance of the variability of Mhc genes in the face of various pathogenic pressures. Isolation and sequencing of Mhc class I and IIB alleles revealed that house sparrows have fewer loci and fewer alleles than great reed warblers. In addition, the Mhc class I genes divided in two distinct lineages with different levels of polymorphism, possibly indicating different functional roles for each gene family. This organization is reminiscent of the chicken B complex and Rfp-Y system. The house sparrow Mhc hence appears to be intermediate between the great reed warbler and the chicken Mhc, both in terms of numbers of alleles and existence of within-class lineages. We specifically amplified one Mhc class I gene family and ran the PCR products on DGGE gels. The individuals screened displayed between one and ten DGGE bands, indicating that this method can be used in future studies to explore the ecological impacts of Mhc diversity.

What is the surface specific area of porous cement-based material? A nuclear magnetic relaxation dispersion approach

We propose a new NMR method to measure and follow the evolution of the surface specific area, Sp, of a porous cement-based material. This method, that does not require any preliminary drying process, uses nuclear magnetic relaxation dispersion (NMRD), the measurement of spin-lattice relaxation rate as a function of magnetic field strength or nuclear Larmor frequency. The method is applied for three different mortars samples prepared by mixing cement, sand, silica fume, water and superplasticizer with a water to cement ratio w/c=0.25, 0.38 and 0.65, respectively. The evolution of Sp grows linearly with the degree of advancement of chemical reactions measured by thermal heating and we evidence two relaxation processes independent of the w/c ratio.

Probing the surface area of a cement-based material by nuclear magnetic relaxation dispersion

We show how nuclear magnetic spin-lattice relaxation dispersion of 1H water can provide a direct reliable value of the specific surface area of a cement-based material. The remarkable features of the relaxation dispersion support an interpretation in terms of coupled solid-liquid relaxation at pore interfaces, surface diffusion, and nuclear paramagnetic relaxation. The measurement is sufficiently fast to be applied continuously during the progressive hydration and setting of the material. This method is relevant to other chemically reactive porous media in chemical engineering and oil recovery.

[Three-dimensional reconstruction calibrated with ultrasonographic images. Application to the measurement of clot volume in vitro]

OBJECTIVE

We used 3D ultrasonographic reconstruction with manual acquisition to study the volume of venous clots in vitro.

MATERIAL AND METHODS

Native 2D ultrasound slices were acquired free hand for 3D reconstruction. The spatial coordinates of each slice were delivered in real time with an electromagnetic captor. We applied a standard ultrasound protocol to test the calibrated 3D reconstruction quantitatively. The volume of 5 clots of increasing size was quantified in vitro using manual segmentation in a double-blind manner by two independent operators.

RESULTS

The comparison tests and the interoperator regression lines evidenced good agreement between real and measured volumes, confirming the coherence of the reconstruction protocol and the feasibility of this technique in a routine medical setting. Intraoperator variability was 7 to 11% and interoperator variability 16.9%.

CONCLUSION

This calibrated 3D reconstruction is compatible with in vitro measurement of venous clots. This technique could be useful to follow the evolution of the head of proximal deep vein thrombi in vivo. It will be more reliable with semi-automatic or even automatic segmentation becomes available.

Variability of sperm specific histones in sea urchins

The variability of sperm histones was compared in two species of sea urchin. Whole sperm specific histones (SpH), were isolated from Tetrapygus niger (Arbacoida) and Parechinus angulosus (Echinoida). Individual histones were purified by chromatography on BioGel P-60 followed by reverse high pressure liquid chromatography (HPLC). The heterogeneity of each major histone type from T. niger was established from their HPLC elution patterns and further confirmed by electrophoresis in polyacrylamide gels containing 6 mM Triton X-100 combined with a transverse urea gradient (0--8 M). In T. niger, as well as in P. angulosus, a single form of SpH1 and SpH2A were found. In contrast, SpH2B was found to be heterogeneous, but represented by one major form in both species. The relatedness between both sets of histones was determined by establishing their immunological cross-reactivity. In this context, polyclonal antibodies elicited against T. niger sperm histones were assayed against individual histones from P. angulosus. From the results obtained, it emerged that histone SpH2A was the more closely related protein between these two species, followed by histone SpH1. In contrast, histone SpH2B was found to be only moderately related. These results confirm that SpH2A did not co-evolve with SpH2B, as was predicted for most species.

Post-synchronized scintigraphic data to estimate antral motility

We evaluated an improved dynamic antral scintigraphy (DAS) technique, without any frequency filtering or computation of an autocorrelation function. This DAS was performed in 15 consecutive patients and 10 healthy volunteers. Antral frequency was first estimated and was given as an input parameter to compute phase and amplitude values in each antral pixel. Motility indices were calculated by multiplying the frequency by a normalized amplitude in the whole antrum. In addition, a gastric emptying (GE) test was performed. Only 10 patients had a delayed GE when using a cut-off value of the mean of half emptying time (T +2SD) obtained in controls. Antral frequencies were significantly increased but motility indices were significantly lower in patients than in controls. These results in patients were accounted for by a retention of food in the antrum. Therefore, amplitude normalization by the antral mean count activity of each set of data was essential for discriminating between patients and controls and normalized indices appeared early predictors of hypomotility in patients with normal GE. This improved DAS technique should be a useful tool to assess antral dysmotility noninvasively, and may be of physiological and clinical interest.

Early onset and familial predisposition to prostate cancer significantly enhance the probability for breast cancer in first degree relatives

Genetic predisposition accounts for >/=10% of all cancer of the prostate (CaP) and is therefore considered a major risk factor, together with age and ethnic origin. Several epidemiological studies have suggested that familial clustering of CaP may be associated with an increased frequency of breast and other cancers among relatives. In order to correlate the incidence of CaP with prevalence of breast and other cancers, we have performed uni- and multi-variate analyses on 691 complete pedigrees including probands, who were consecutive patients with confirmed CaP treated in three French urological departments. We have shown a significantly higher risk (RR = 2.3, p = 0.01) to develop breast cancer in families with multiple than in those with a single CaP. Risk of observing other types of cancer within these families was not significant. We then calculated the breast cancer risk in early onset prostate cancer families, and observed a relative risk that is even more significant (RR = 5.5, p = 0.002). Furthermore, the risk was >30 times that a proband's mother have breast cancer if CaP occurred below 55 years of age, rather than after 75 years (p = 0.003). This study has therefore shown for the first time, the relatively high penetrance for breast cancer in relatives of early onset CaP patients.

Phosphonocationic lipids in protein delivery to mice lungs

Cationic liposomes constitute one of the main approaches currently investigated to introduce a gene with therapeutic properties into a cell. Another alternative consists in directly introducing the normal protein of concern to, for example, restore the deleted function. We report here on in vitro and in vivo results obtained with GLB73, one of the phosphonolipids investigated as gene transfer agents. In previous studies this cationic lipid had shown its DNA-transfer efficacy in vitro and in vivo. We also confirmed the feasibility of protein/cationic lipid delivery in epithelial cells of mice lungs after intratracheal administration by use of a reporter gene (beta-galactosidase). Two quantitative tests (i.e., a chemiluminescent assay and a flow cytometry assay) were used to determine the amount of beta-galactosidase found in the lungs and the percentage of transfected cells. They showed that 50% of the cells of mice lungs were still positive at day 4 after protein/GLB73 delivery. Immunohistochemistry and electron microscopy studies allowed us to determine the spatial distribution and visualize the penetration of our complex into the lungs.

Combined lumbar and sacral plexus block compared with plain bupivacaine spinal anesthesia for hip fractures in the elderly

BACKGROUND AND OBJECTIVES

This prospective randomized study was designed to determine the hemodynamic effects and quality of combined lumbar and sacral plexus block compared with plain bupivacaine spinal anesthesia in the elderly for repair of proximal femoral fractures.

METHODS

Twenty-nine elderly patients ranging in age from 68 to 97 years were randomly assigned to 2 groups: a spinal anesthesia group with single-shot 3 mL 0.5% plain bupivacaine, and a combined block group with 30 mL lidocaine 1.33% with epinephrine for the posterior lumbar plexus block and 10 mL same mixture for the parasacral block and an iliac crest block with 5 mL lidocaine 1%.

RESULTS

No need for general anesthesia was encountered in either group. Anesthesia was judged unsatisfactory in 1 of 15 patients in the combined block group. The initial decrease of mean arterial pressure was 38% in the spinal group and 27% in the block group and was not significantly different. A more prolonged hemodynamic effect was found in the spinal group, indicated by the more frequent use of ephedrine to stabilize blood pressure (P<.05). Patients over 85 years had a significantly larger decrease in blood pressure than younger patients (P<.01).

CONCLUSIONS

Plain bupivacaine spinal anesthesia and combined lumbar/sacral plexus block provided adequate anesthesia for repair of hip fracture in the elderly. Hypotension was induced by both the combined peripheral nerve block and plain bupivacaine spinal anesthesia in aged patients; hypotension was found to be longer lasting after spinal anesthesia and of a larger magnitude in patients over 85 years of age.

Potential involvement of post-translational modifications as a mechanism modulating selective proteolysis after fertilization

The role of proteolysis during fertilization has been investigated only to a very limited extent as compared with its role on the control of cell cycle progression. In this report, we discuss briefly the proteases involved in fertilization, their relevance in the egg-sperm interaction and in the chromatin remodeling that occurs before the reestablishment of the diploid condition of the zygote. We further emphasize how the post-translational modifications of target proteins modulate these proteolytic events. J. Cell. Biochem. Suppls. 32/33:149-157, 1999.

Phosphorylation protects sperm-specific histones H1 and H2B from proteolysis after fertilization

At intermediate stages of male pronucleus formation, sperm-derived chromatin is composed of hybrid nucleoprotein particles formed by sperm H1 (SpH1), dimers of sperm H2A-H2B (SpH2A-SpH2B), and a subset of maternal cleavage stage (CS) histone variants. At this stage in vivo, the CS histone variants are poly(ADP-ribosylated), while SpH2B and SpH1 are phosphorylated. We have postulated previously that the final steps of sperm chromatin remodeling involve a cysteine-protease (SpH-protease) that degrades sperm histones in a specific manner, leaving the maternal CS histone variants unaffected. More recently we have reported that the protection of CS histones from degradation is determined by the poly(ADP-ribose) moiety of these proteins. Because of the selectivity displayed by the SpH-protease, the coexistence of a subset of SpH together with CS histone variants at intermediate stages of male pronucleus remodeling remains intriguing. Consequently, we have investigated the phosphorylation state of SpH1 and SpH2B in relation to the possible protection of these proteins from proteolytic degradation. Histones H1 and H2B were purified from sperm, phosphorylated in vitro using the recombinant alpha-subunit of casein kinase 2, and then used as substrates in the standard assay of the SpH-protease. The phosphorylated forms of SpH1 and SpH2B were found to remain unaltered, while the nonphosphorylated forms were degraded. On the basis of this result, we postulate a novel role for the phosphorylation of SpH1 and SpH2B that occurs in vivo after fertilization, namely to protect these histones against degradation at intermediate stages of male chromatin remodeling.

Poly(ADP-ribosylation) protects maternally derived histones from proteolysis after fertilization

Fertilization in sea urchins is followed by the replacement of sperm-specific histones by cleavage-stage histone variants recruited from maternal stores. Such remodelling of zygote chromatin involves a cysteine proteinase that degrades the sperm-specific histones in a selective manner, leaving the maternal cleavage-stage histone variants intact. The mechanism that determines the selectivity of the sperm-histone-selective proteinase (SpH-proteinase) was analysed by focusing on the post-translational modification status of both sets of histones. It has previously been reported that only native cleavage-stage histones are poly(ADP-ribosylated), whereas the sperm-specific histones are not modified. To determine whether the poly(ADP-ribose) moiety afforded protection from degradation, the ADP-ribose polymers were removed from the cleavage-stage histones in vitro; these proteins were then assayed as potential substrates of the SpH-proteinase. Strikingly, the cleavage-stage histone variants were extensively degraded after the enzymic removal of their ADP-ribose moieties. In addition, the SpH cysteine proteinase was not inhibited by isolated poly(ADP-ribose) polymers. Consequently, only poly(ADP-ribosylated) cleavage-stage histone variants are protected from proteolysis. These results demonstrate a novel role for this type of post-translational modification, namely the protection of nuclear proteins against nuclear proteinases after fertilization.

Cationic phosphonolipids as nonviral gene transfer agents in the lungs of mice

With the aim of developing new gene transfer tools for treating CF with gene therapy, we have synthesized a novel family of molecules named cationic phosphonolipids. The most efficient among them were selected by in vitro screening to compare their activities in vivo in mouse lungs. We used a reporter gene whose activity was measured cytofluorimetrically (FACS-Gal assay) and by means of a chemiluminescence technique. These tests allowed us to identify the percentage of transfected cells and to quantify total beta-galactosidase in the lungs. This enabled us to identify two molecules, significantly efficient in comparison with DNA alone: GLB73 (p = 0.0015) and GLB253 (p = 0.007). Their use resulted in a time lag between transfection and maximum efficiency: maximum efficiency was observed 4 days after transfection with GLB73, whereas it was noticeable only on day 7 with GLB253. Moreover, from toxicity studies carried out in vivo, GLB73 seems to be nontoxic. In vivo results were correlated with in vitro results obtained with CF epithelial cell lines. Consequently, GLB73 is a potential candidate for phase I clinical trials in humans.