Cephalad-caudad vs transverse blunt expansion of low transverse hysterotomy during caesarean section and risk of severe postpartum haemorrhage: A prospective comparative study.

BACKGROUND: The global prevalence of caesarean section as a delivery method is increasing worldwide. However, there is notable divergence among countries in their national guidelines regarding the optimal technique for blunt expansion hysterotomy of the low transverse uterine incision during caesarean section (cephalad-caudad or transverse). AIM: To compare the risk of severe postpartum haemorrhage (PPH) between cephalad-caudad and transverse blunt expansion hysterotomy during caesarean section. METHODS: This prospective comparative observational study was conducted in a university maternity hospital. All women who gave birth to one infant by caesarean section after 30 weeks of gestation between November 2020 and November 2021 were included in this study. The exclusion criteria were a coagulation disorder, the presence of placenta previa, multiple pregnancies, or enlargement of the hysterotomy with scissors. The choice between cephalad-caudad or transverse blunt expansion of the low transverse hysterotomy was left to the surgeon's discretion. The primary outcome measure was severe PPH, defined as estimated blood loss ≥ 1000 ml. Univariate and multivariate analyses were employed to assess the risk of severe PPH associated with the two methods of enlarging the low transverse hysterotomy. RESULTS: The study included 850 women, of whom 404 underwent transverse blunt expansion and 446 underwent cephalad-caudad blunt expansion. The overall incidence of severe PPH was 13.3 %. Univariate analysis revealed no significant difference in the frequency of severe PPH between the cephalad-caudad and transverse blunt expansion groups (13.9 % vs 12.6 %; p = 0.61). However, the use of additional surgical sutures (mainly additional haemostatic stitches) was less common with cephalad-caudad blunt expansion (26.7 % vs 36.9 %; p < 0.05). Multivariate analysis showed no significant difference in risk between the two techniques (odds ratio 1.17, 95 % confidence interval 0.77-1.78). CONCLUSION: No significant difference in the risk of severe PPH was found between cephalad-caudad and transverse blunt expansion of the low transverse hysterotomy during caesarean section.

[Intrahepatic cholestasis of pregnancy: French College of Obstetricians and Gynecologists guidelines for clinical practice]. / La cholestase gravidique : recommandations pour la pratique clinique du Collège national des gynécologues obstétriciens français.

OBJECTIVE: To identify strategies for reducing neonatal and maternal morbidity associated with intrahepatic cholestasis pregnancy (ICP). MATERIAL AND METHODS: The quality of evidence of the literature was assessed following the GRADE methodology with questions formulated in the PICO format (Patients, Intervention, Comparison, Outcome) and outcomes defined a priori and classified according to their importance. An extensive bibliographic search was performed on PubMed, Cochrane, EMBASE and Google Scholar databases. The quality of the evidence was assessed (high, moderate, low, very low) and a (i) strong or (ii) weak recommendations or (iii) no recommendation were formulated. The recommendations were reviewed in two rounds with external reviewers (Delphi survey) to select the consensus recommendations. RESULTS: Of the 14 questions (from 12 PICO questions and one definition question outside the PICO format), there was agreement between the working group and the external reviewers on 14 (100%). The level of evidence of the literature was insufficient to provide a recommendation on two questions. ICP is defined by the occurrence of suggestive pruritus (palmoplantar, nocturnal) associated with a total bile acid level>10µmol/L or an alanine transaminase level above 2N after ruling out differential diagnoses. In the absence of suggestive symptoms of a differential diagnosis, it is recommended not to carry out additional biological or ultrasound tests. In women with CIP, ursodeoxycholic acid is recommended to reduce the intensity of maternal pruritus (Strong recommendation. Quality of the evidence moderate) and to decrease the level of total bile acids and alanine transaminases. (Strong recommendation. Quality of the evidence moderate). S-adenosyl-methionine, dexamethasone, guar gum or activated charcoal should not be used to reduce the intensity of maternal pruritus (Strong recommendation. Quality of evidence low), and there is insufficient data to recommend the use of antihistamines (No recommendation. Quality of evidence low). Rifampicin (Weak recommendation. Very low quality of evidence) or plasma exchange (Strong recommendation. Very low quality of evidence) should not be used to reduce maternal pruritus and perinatal morbidity. Serum monitoring of bile acids is recommended to reduce perinatal morbidity and mortality (stillbirth, prematurity) (Low recommendation. Quality of the evidence low). The level of evidence is insufficient to determine whether fetal heart rate or fetal ultrasound monitoring are useful to reduce perinatal morbidity (No recommendation). Birth is recommended when bile acid level is above 99µmol/L from 36 weeks gestation to reduce perinatal morbidity, in particular stillbirth. When bile acid level is above 99µmol/L is below 100µmol/L, women should be informed that induction of labor could be considered 37 and 39 weeks gestation to reduce perinatal morbidity. (Strong recommendation. Quality of evidence low). In postpartum, total bile acids and alanine transaminases level should be checked and normalized before prescribing estrogen-progestin contraception, ideally with a low estrogen dose (risk of recurrence of pruritus and cytolysis) (Low recommendation. Quality of evidence very low). CONCLUSION: Although the quality of evidence regarding ICP gestational cholestasis remains low, there is a strong consensus in France, as shown by our Delphi study, on how to manage women with ICP. The reference first-line treatment is ursodeoxycholic acid.

[Vagal sensory reinnervation and composition of the sterno-cephalic muscle in rabbits]. / Réinnervation vagale sensitive et la composition du muscle sternocéphalique chez le lapin.

The crossed nerve anastomosis between the peripheral end of the vagus nerve, cut above the nodose ganglion, and the peripheral end of the accessory nerve has demonstrated the capacity of some vagal afferents to reinnervate, via the accessory nerve stump, certain sternocephalicus muscle fibers in the rabbit. These results add to our understanding of the capacity of these afferents to counter the past-denervational atrophying process that occurs in the reinnervated muscles and to evaluate the changes induced in these muscles during reinnervation. Our work shows that within 3 months, the vagal sensory reinnervation of previously denervated sternocephalicus muscles induces their total weight recovery. This recovery is concomitant on the one hand with the hypertrophy of the four muscle fiber types (I, IIBD, IIC and IIA) identified histochemically in the normal muscles and, on the other, with the appearance of small newly formed myofibers, which are often underlined by characteristic central nuclei. The vagal sensory neurones induce important changes in the percentages and the muscle cross-sectional distribution of the fibers in reinnervated muscles. In these muscles we see also the disappearance of the fast myosin heavy chains MHCIIB and MHCIID, the upholding of the fast MHCIIA percentage and an increase in the slow MHCI isoform.

In vitro infection of epidermal Langerhans cells with human immunodeficiency virus type 1 (HTLV-IIIB isolate).

Human epidermal Langerhans cells (LC) isolated from normal skin were infected in vitro with human immunodeficiency virus type 1 (HIV1). To control the permissivity of LC for HIV1, cells isolated from the epidermal sheet of normal skin by trypsinization were cocultured with HIV1-carrying promonocytic cells (U937) and observed by electron microscopy. An early sign of infection occurring in the coculture was the formation of retroviral type buds from LC membrane. Different steps in the process of viral budding up to virus release into the extracellular space were observed by electron microscopy. Treatment with either coupled phorbol esters/bacterial lipopolysaccharide or a recombinant cytokine (tumour necrosis factor alpha) did not significantly enhance viral production. The ability of in vitro infected LC to transmit virus to other haematopoietic cells and the consequences of such an infection on antigen-presenting function of LC remain to be elucidated.

In vitro HIV-1 entry and replication in Langerhans cells may clarify the HIV-1 genome detection by PCR in epidermis of seropositive patients.

Being dendritic antigen-presenting cells in skin and mucous membrane, Langerhans cells (LC) occur in areas at risk for inoculation by human immunodeficiency virus (HIV), and the question whether LC act as a target, reservoir, or vector for transmission of HIV has given rise to much controversy. To address this question, we first analyzed the epidermal compartment of skin from patients seropositive for HIV DNA. Second, we tested the susceptibility of each cell type normally found in this compartment to in vitro infection by HIV-1. A non-denatured DNA was obtained from epidermal sheets after a thermochemical treatment of biopsies (0.5 M ethylenediaminetetraacetic acid (EDTA), pH 7.5 at 60 degrees C for 90 seconds). Optimization of amplification of viral genome was performed with three primer pairs derived from gag, env, and pol sequences. Polymerase chain reaction (PCR) products were analyzed by Southern blot. Viral genome was found in five of 11 HIV-seropositive patients. To control the permissivity of epidermal cell population for HIV, cells isolated from the epidermal sheet of normal skin by trypsinization were co-cultured with HIV-1-carrying promonocytic cells (U937) and observed by electron microscopy. After 3-6 h of co-culture, numerous virions were either tightly bound or apparently engaged in the process of internalization through receptor-mediated endocytosis. At day 4 of co-culture, some infected LC appeared to release mature viral particles through bud formation. The in vitro HIV-1 entry and replication in LC may confirm the presence of the HIV-1 genome by PCR in epidermis of seropositive patients. The consequences of the permissivity of LC for HIV on the antigen-presenting function remain to be determined.

In vitro adhesion of human epidermal Langerhans cells to laminin and fibronectin occurs through beta 1 integrin receptors.

Human epidermal Langerhans cells are dendritic cells that can capture, process, and present antigens to T cells. It was previously shown that these Langerhans cells express the very late activation antigen (VLA) protein family of beta 1 integrins. beta 1 integrins mainly mediate the adhesion of cells to a number of extracellular components, such as laminin, fibronectin, and collagen, which are present in the skin. In this report, we demonstrate that a large percentage of the Langerhans cell population was able in vitro to attach to laminin and fibronectin but not to collagen. An ultrastructural study of adherent Langerhans cells showed that they were spread largely on laminin, with a loss of their round shape, and partially on fibronectin. Langerhans cell binding to laminin or fibronectin induced a decrease of the Birbeck granule number. Specific inhibitions of cell adhesion were performed, and it was demonstrated that VLA-6 was the major receptor involved in Langerhans cell adhesion to laminin. This adhesion was not RGD dependent and was slightly enhanced by Mn2+. VLA-3 and especially VLA-5 mediated Langerhans cell binding to fibronectin through the RGDS sequence of the protein. Mn2+ sharply increased the Langerhans cell adhesion to fibronectin. VLA-6 mediated in vitro Langerhans cell adhesion to laminin, which suggests that in vivo VLA-6 could permit Langerhans cells to attach and migrate through the basement membrane. Moreover, VLA-5 and VLA-3 take part in the in vitro Langerhans cell binding to fibronectin, suggesting that in vivo these fibronectin receptors could facilitate Langerhans cell passage throughout the fibronectin network of the dermis before migration to lymph nodes.

Biochemical and ultrastructural study of glycogen in cultured astrocytes submitted to the convulsant methionine sulfoximine.

The convulsant methionine sulfoximine is a potent glycogenic agent in the central nervous system of rodents in vivo. This investigation was undertaken to look for the basic mechanism underlying this property. Astrocytes were cultivated from newborn rat neopallium and glycogen was studied by both biochemical and ultrastructural methods. When the astrocytes were incubated in a medium containing 5.55 mM glucose, methionine sulfoximine (0.55 mM) induced a significant increase in their glycogen content. Glucose content did not change in astrocytes, but it diminished in the medium in all cases. When the decrease in glucose level in the medium was limited, the same glycogenic effects of methionine sulfoximine were observed, but the glycogen contents were higher. The augmentation of the concentration of the convulsant enhanced its glycogenic effect, but this was not directly dose dependent. When the flat and polygonal astrocytes were transformed into process-bearing astrocytes by dibutyryl cyclic AMP methionine sulfoximine always induced an increase in glycogen content. In this case, the values of glycogen contents were lower. In electron microscopy, no glycogen particles were present in the astrocytes even after methionine sulfoximine treatment, contrary to the case in vivo. These results show that the convulsant does not need the presence of neuronal cells to induce glycogen accumulation and that astrocytes may be the direct cell targets. The apparent discrepancy between the biochemical and ultrastructural data is probably due to the relatively low concentration of glycogen in cultured astrocytes.

Diffusion of horseradish peroxidase perfused through the lateral ventricle of the chick telencephalon.

Horseradish peroxidase, perfused into the lateral ventricle of chick brain, freely and slowly diffuses through the cerebral extracellular spaces. The layer of astrocytic end-feet surrounding blood capillaries does not consitute a barrier to the tracer which permeates the basal lamina, diffuses between the pericytic cells and finally accumulates in the intercellular space beneath the tight junctions between contiguous endothelial cells. No evidence was found for transport by micropinocytotic vesicles from the cerebral parenchyma to the capillary lumen.