[Clinical characteristics of severe pre-eclampsia in a single tertiary referral center of Xiamen City].

Objective: To explore the key points for preventing and reducing severe pre-eclampsia (SPE) and its severe complications in the tertiary medical referral system of a second-tier city by analyzing the clinical characteristics of SPE. Methods: The clinical data of 341 patients with SPE who terminated pregnancy in Women and Children's Hospital, School of Medicine, Xiamen University, from January 1, 2020 to December 31, 2022 were retrospectively analyzed, and the pre-eclampsia (PE) risk factors, clinical characteristics and severe complications of SPE between the patients referred from primary hospitals (referral group) and the patients received regular prenatal care in the tertiary referral center (central group) were compared, as well as the influence of the referral timing on the maternal and perinatal outcomes. Results: Among the 341 cases of SPE, 92 cases were in the referral group and 249 cases were in the central group. (1) Analysis of PE risk factors: there was no statistical difference in the proportion of risk factors of PE between these two groups [75.0% (69/92) vs 71.9% (179/249); χ2=0.328, P=0.567]. (2) Analysis of clinical features: the gestational ages at the PE early warning factors onset, at the PE first symptom onset and at SPE diagnosed, pregnancy terminated and onset of SPE severe complications in the referral group were significantly earlier than those in the central group (all P<0.05), the proportions of terminating pregnancy before 32 weeks of gestation, between 32 and 34 weeks of gestation, intensive care unit (ICU), neonatal ICU hospitalization and fetal growth restriction in single pregnancies were higher than those in the central group, while the live birth rate was lower than that in the central group (all P<0.05). (3) Analysis of SPE severe complications: the rates of SPE severe complications in the referral group was higher than that in the central group [28.3% (26/92) vs 13.7% (34/249); χ2=9.885, P=0.002]. Among them, the rates of placental abruption [7.6% (7/92) vs 2.8% (7/249); χ2=3.927, P=0.048] and still birth [6.5% (6/92) vs 0.4% (1/249); χ2=9.656, P=0.002] in the referral group were significantly higher than those in the central group. (4) Analysis of referral timings: the timings included referral after onset of SPE severe complications (9.8%, 9/92), referral after SPE diagnosed (63.0%, 58/92), referral after detection of SPE early warning signs (20.7%, 19/92) and referral after detection of PE risk factors (6.5%, 6/92). The gestational ages at SPE diagnosed and pregnancy terminated in group of referral after onset of SPE severe complications and group of referral after SPE diagnosed were significantly earlier than those in group of referral after detection of PE early warning signs and group of referral after detection of PE risk factors (P<0.05). The earlier the referral, the higher the live birth rates (P<0.05). Conclusions: The tertiary referral center of the second-tier city plays an important role in reducing the maternal and perinatal damage of PE. The timing of referral in primary medical institutions is the key point of reducing the occurrence of SPE severe complications and maternal, perinatal damage of PE. It is necessary for medical institutions of all levels in all regions to improve the ability of early identification and early intervention for PE, to enhance the awareness of SPE and its severe complications prevention and control. Primary medical institutions should especially pay attention to raise the consciousness of PE risk factors and early warning signs, and to improve the ability of PE risk factors and early warning signs screening.

Large-scale analysis of gene expression changes during acute and chronic exposure to [Delta]9-THC in rats.

Large-scale cDNA microarrays were employed to assess transient changes in gene expression levels following acute and chronic exposure to cannabinoids in rats. A total of 24,456 cDNA clones were randomly selected from a rat brain cDNA library, amplified by PCR, and arrayed at high density to investigate differential gene expression profiles following acute (24 h), intermediate (7 days), and chronic (21 days) exposure to Delta(9)-tetrahydrocannabinol (Delta(9)-THC), the psychoactive ingredient of marijuana. Hippocampal mRNA probes labeled with (33)P obtained from both vehicle and Delta(9)-THC-treated animals were hybridized with identical cDNA microarrays. Results revealed a total of 49 different genes altered by Delta(9)-THC exposure; of these, 28 were identified, 10 had homologies to expressed sequence tags (ESTs), and 11 had no homology to known sequences in the GenBank database. Chronic or acute cannabinoid receptor activation altered expression of several genes (i.e., prostaglandin D synthase, calmodulin) involved in biochemical cascades of cannabinoid synthesis or cannabinoid effector systems. Other genes [i.e., neural cell adhesion molecule (NCAM), myelin basic protein], whose relation to cannabinoid system function was not immediately obvious, were also significantly altered. Verification of the changes obtained with the large-scale screen was determined by RNA dot blots in different groups of animals treated the same as those in the large-scale screen. Results are discussed in terms of the different types of genes affected at different times during chronic Delta(9)-THC exposure.

Role of cyclic AMP dependent protein kinase in cannabinoid receptor modulation of potassium "A-current" in cultured rat hippocampal neurons.

Cannabinoid receptor agonists have been previously shown to enhance a potassium A-current (IA) in cultured rat hippocampal neurons. This effect has been further demonstrated to be dependent on G-protein linkage to adenylyl cyclase and levels of intracellular cyclic AMP (cAMP). The present study extends this analysis to the involvement of cAMP-dependent protein kinase (PKA) in this cascade. Specific activators and inhibitors of PKA were shown to have differential effects on the voltage dependence of IA. Specific activators of PKA produced a negative shift in voltage dependence of IA, whereas PKA inhibitors produced a positive shift in IA voltage dependence, the latter similar to that effected by the cannabinoid agonist WIN 55,212-2. Although the negative shift in IA induced by PKA stimulation could be reversed by PKA inhibitors, the positive shift produced by the PKA inhibitors alone was only 50-60% of the cannabinoid-produced shift in IA voltage dependence. This partial effect of PKA inhibition was confirmed by biochemical assays in the same cultured neurons that showed a similar 50-60% decrement in in vitro protein phosphorylation produced by PKA inhibitors. Results are discussed in terms of a diffusible second messenger linkage of the cannabinoid receptor to the A-current channel via the role of protein phosphorylation in modulation of IA.

Protein kinase-dependent phosphorylation and cannabinoid receptor modulation of potassium A current (IA) in cultured rat hippocampal neurons.

The potent cannabinoid receptor agonist WIN 55,212-2 produces positive shifts in steady-state inactivation of the potassium A current (IA) in rat hippocampal neurons via an adenosine 3',5'-cyclic monophosphate (cAMP)-, protein kinase A (PKA)-dependent process. This effect is probably mediated by phosphorylation or dephosphorylation of the IA channel protein. The role of protein phosphorylation in this cascade was tested by testing cannabinoid actions in cultured hippocampal neurons (pyramidal cells) that were exposed also to either the catalytic subunit of PKA (PKAc), a PKA-specific phosphorylation inhibitor (IP-20, Walsh peptide), or a potent protein phosphatase inhibitor (okadaic acid). Cannabinoids such as WIN 55,212-2 produce a positive (rightwards) shift in the steady-state inactivation of IA, thus providing increased current at a given membrane voltage. Cells dialyzed with PKAc showed a negative shift in IA inactivation, opposite to that produced by cannabinoids, and similar to that produced by increased levels of cAMP. In addition, PKAc completely blocked the positive shift produced by WIN 55,212-2. In contrast, dialysis of cells with IP-20 produced a positive shift in steady state inactivation of IA, similar to that produced by WIN, but the effects were not additive with cannabinoid receptor activation. The phosphatase inhibitor, okadaic acid produced a small negative shift in IA steady-state inactivation when administered alone, and blocked the positive shift produced by WIN 55,212-2. Okadaic acid also enhanced the negative shift in IA inactivation when co-administered with forskolin. The effects of okadaic acid and WIN 55,212-2 were not additive, suggesting a common pathway. These results demonstrate that IA is altered by direct manipulations of the phosphorylation status of the channel protein, and that cannabinoid effects on IA are probably mediated by dephosphorylation of the IA channel.

Cannabinoid receptors differentially modulate potassium A and D currents in hippocampal neurons in culture.

Cannabinoid (CB(1)) receptor activation produced differential effects on voltage-gated outward potassium currents in whole-cell recordings from cultured (7-15 days) rat hippocampal neurons. Voltage-dependent potassium currents A (I(A)) and D (I(D)) were isolated from a composite tetraethylammonium-insensitive current (I(comp)) by blockade with either 4-aminopyridine (500 microM) or dendrotoxin (2 microM) and subtraction of the residual I(A) from I(comp) to reveal I(D). The time constants of inactivation (tau) of I(A) and I(D) as determined in this manner were found to be quite different. The CB(1) agonist WIN 55,212-2 produced a 15- to 20-mV positive shift in voltage-dependent inactivation of I(A) and a simultaneous voltage-independent reduction in the amplitude of I(D) in the same neurons. The EC(50) value for the effect of WIN 55,212-2 on I(D) amplitude (13.9 nM) was slightly lower than the EC(50) value for its effect on I(A) voltage dependence (20.6 nM). Pretreatment with either the CB(1) antagonist SR141716A or pertussis toxin completely blocked the differential effects of WIN 55,212-2 on I(A) and I(D), whereas cellular dialysis with guanosine-5'-O-(3-thio)triphosphate mimicked the action of cannabinoids but blocked the action of simultaneously administered cannabinoid receptor ligands. Finally, the differential effects of cannabinoids on I(A) and I(D) were both shown to be mediated via the well documented cannabinoid receptor inhibition of adenylyl cyclase and subsequent modulation of cAMP and protein kinase. These actions are considered in terms of cAMP-mediated phosphorylation of separate I(A) and I(D) channels and the contribution of each to composite voltage-gated potassium currents in these cells.