[Investigation of pregestational diabetes mellitus in 15 hospitals in Guangdong province].

Objective: To investigate the morbidity, diagnostic profile and perinatal outcome of pregestational diabetes mellitus (PGDM) in 15 hospitals in Guangdong province. Methods: A total of 41 338 women delivered in the 15 hospitals during the 6 months, 195 women with PGDM (PGDM group) and 195 women with normal glucose test result (control group) were recruited from these tertiary hospitals in Guangdong province from January 2016 to June 2016. The morbidity and diagnostic profile of PGDM were analyzed. The complications during pregnancy and perinatal outcomes were compared between the two groups. In the PGDM group, pregnancy outcomes were analyzed in women who used insulin treatment (n=91) and women who did not (n=104). Results: (1) The incidence of PGDM was 0.472%(195/41 338). Diabetes mellitus were diagnosed in 59 women (30.3%, 59/195) before pregnancy, and 136 women (69.7%,136/195) were diagnosed as PGDM after conceptions. Forty-six women (33.8%) were diagnosed by fasting glucose and glycohemoglobin (HbA1c) screening. (2) The maternal age, pre-pregnancy body mass index (BMI) , prenatal BMI, percentage of family history of diabetes, incidence of macrosomia, concentration of low density lipoprotein were significantly higher in PGDM group than those in control group (all P<0.05). Women in PGDM group had significantly higher HbA1c concentration ((6.3±1.3)% vs (5.2±0.4)%) , fasting glucose [(6.3±2.3) vs (4.8±1.1) mmol/L], oral glucose tolerance test (OGTT) -1 h glucose ((12.6±2.9) vs (7.1±1.3) mmol/L) and OGTT-2 h glucose [(12.0±3.0) vs (6.4±1.0) mmol/L] than those in control group (P<0.01). (3) The morbidity of preterm births was significantly higher (11.3% vs 1.0%, P<0.01), and the gestational age at delivery in PGDM group was significantly smaller [(37.6±2.3) vs (39.2±1.2) weeks, P<0.01]. Cesarean delivery rate in the PGDM group (70.8% vs 29.7%) was significantly higher than the control group (P<0.01). There was significantly difference between PGDM group and control in the neonatal male/female ratio (98/97 vs 111/84, P=0.033). The neonatal birth weight in PGDM group was significantly higher ((3 159±700) vs (3 451±423) g, P<0.01) . And the incidence of neonatal hypoglycemia in the PGDM group was higher than the control group (7.7% vs 2.6%, P=0.036). (4) In the PGDM group, women who were treated with insulin had a smaller gestational age at delivery [(36.9±2.9) vs (37.9±2.5) weeks, P<0.01], and the neonates had a higher neonatal ICU (NICU) admission rate (24.2% vs 9.6%, P<0.01). Conclusions: The morbidity of PGDM in the 15 hospitals in Guangdong province is 0.472%. The majority of PGDM was diagnosed during pregnancy; HbA1c and fasting glucose are reliable parameters for PGDM screening. Women with PGDM have obvious family history of diabetes and repeated pregnancy may accelerate the process of diabetes mellitus. Women with PGDM have higher risk for preterm delivery and neonatal hypoglycemia. Unsatisfied glucose control followed by insulin treatment may increase the need for NICU admission.

Regulation of electrical activity and neuronal excitability in Helisoma trivolvis by carbon monoxide.

Carbon monoxide (CO), like other gaseous neuromodulators, has a dual nature as both a toxic gas and a physiologically relevant signaling molecule. In the nervous system, high concentrations of CO can lead to neuronal injury while lower concentrations are found to be neuroprotective. The number of cellular targets affected by physiological concentrations of CO is rapidly growing and includes ion channels in various cell types. The modulation of ion channels by CO in neurons, however, and the effect it has on neural activity are incompletely understood. Here, the well-characterized buccal neurons, B5 and B19, of the freshwater snail, Helisoma trivolvis, were used to investigate the role that CO plays in regulating spontaneous firing activity and neuronal excitability. Neurons were studied in single-cell culture, thereby removing other signals normally present in the intact nervous system and allowing for the optimal characterization of physiological effects of CO. We found that the CO donor molecule, carbon monoxide releasing molecule-2 (CORM-2), hyperpolarized the resting membrane potential of B5 neurons and silenced their spontaneous firing activity. These effects were mediated through the inhibition of a persistent sodium current. CORM-2 also inhibited neuronal excitability. This effect was mediated by the inhibition of voltage-gated calcium channels by CO. The general findings of CO acting as a hyperpolarizing signal and an inhibitor of neuronal excitability extended to B19 neurons. Taken together, these findings suggest that CO is a potent modulator of ion channels with broad implications for the modulation of neural activity in a wide range of neuron-types.

Dopamine suppresses neuronal activity of Helisoma B5 neurons via a D2-like receptor, activating PLC and K channels.

Dopamine (DA) plays fundamental roles as a neurotransmitter and neuromodulator in the central nervous system. How DA modulates the electrical excitability of individual neurons to elicit various behaviors is of great interest in many systems. The buccal ganglion of the freshwater pond snail Helisoma trivolvis contains the neuronal circuitry for feeding and DA is known to modulate the feeding motor program in Helisoma. The buccal neuron B5 participates in the control of gut contractile activity and is surrounded by dopaminergic processes, which are expected to release DA. In order to study whether DA modulates the electrical activity of individual B5 neurons, we performed experiments on physically isolated B5 neurons in culture and on B5 neurons within the buccal ganglion in situ. We report that DA application elicited a strong hyperpolarization in both conditions and turned the electrical activity from a spontaneously firing state to an electrically silent state. Using the cell culture system, we demonstrated that the strong hyperpolarization was inhibited by the D2 receptor antagonist sulpiride and the phospholipase C (PLC) inhibitor U73122, indicating that DA affected the membrane potential of B5 neurons through the activation of a D2-like receptor and PLC. Further studies revealed that the DA-induced hyperpolarization was inhibited by the K channel blockers 4-aminopyridine and tetraethylammonium, suggesting that K channels might serve as the ultimate target of DA signaling. Through its modulatory effect on the electrical activity of B5 neurons, the release of DA in vivo may contribute to a neuronal output that results in a variable feeding motor program.