Molecular Effects of Li+-Coordinating Binders and Negatively Charged Binders on the Li+ Local Mobility near the Electrolyte/LiFePO4 Cathode Interface within Lithium-Ion Batteries

The development of lithium-ion batteries (LIBs) is important in the realm of energy storage. Understanding the intricate effects of binders on the Li+ transport at the cathode/electrolyte interface in LIBs remains a challenge. This study utilized molecular dynamics simulations to compare the molecular effects of conventional polyvinylidene difluoride (PVDF), Li+-coordinating polyethylene oxide (PEO), and negatively charged polystyrene sulfonate (PSS) binders on local Li+ mobility at the electrolyte/LiFePO4 (LFP) cathode interface. By examining concentration profiles of Li+, three different polymer binders, and anions near Li+-rich LFP and Li+-depleted FePO4 (FP) surfaces, we found a superior performance of the negatively charged PSS on enhancing Li+ distribution near the Li+-depleted FP surface. The radial distribution function and coordination number analyses revealed the potent interactions of PEO and PSS with Li+ disrupting Li+ coordination with electrolyte solvents. Our simulations also revealed the effects of non-uniform binder dispersions on the Li+ local mobility near the cathode surface. The combined results provide a comparative insight into Li+ transport at the electrolyte/cathode interface influenced by distinct binder chemistries, offering a profound understanding of the binder designs for high-performance LIBs.

Academic libraries and research data management: a case study of Dataverse global adoption

Purpose

The purpose of this study is to examine the development of Dataverse, a global research data management consortium. The authors examine specifically the institutional characteristics, the utilization of the associated data sets and the relevant research data management services at its participating university libraries. This evidence-based approach is essential for understanding the current state of research data management practices in the global context.

Design/methodology/approach

The data was collected from 67 participants’ data portals between December 1, 2020, and January 31, 2021.

Findings

Over 80% of its current participants joined the group in the past five years, 2016–2020. Thirty-three Dataverse portals have had less than 10,000 total downloads since their inception. Twenty-nine participating universities are included in three major global university ranking systems, and 18 of those university libraries offer research data services.

Originality/value

This project is an explorative study on Dataverse, an international research data management consortium. The findings contribute to the understanding of the current development of the Dataverse project as well as the practices at the participating institutions. Moreover, they offer insights to other global higher education institutions and research organizations regarding research data management. While this study is practical, its findings and observations could be of use to future researchers interested in developing a framework for data work in academic libraries.

Sensor Fusion for Simultaneous Estimation of In-Plane Permeability and Porosity of Fiber Reinforcement in Resin Transfer Molding

To meet the expectation of the industry, resin transfer molding (RTM) has become one of the most promising polymer processing methods to manufacture fiber-reinforced plastics (FRPs) with light weight, high strength, and multifunctional features. The permeability and porosity of fiber reinforcements are two of the primary properties that control the flow of resin in fibers and are critical to numerical simulations of RTM. In the past, various permeability measurement methods have been developed in the literature. However, limitations still exist. Furthermore, porosity is often measured independently of permeability. As a result, the two measurements do not necessarily relate to the same entity, which may increase the time and labor costs associated with experiments and affect result interpretation. In this work, a measurement system was developed by fusing the signals from capacitive sensing and flow visualization, based on which a novel algorithm was developed. Without complicated sensor design or expensive instrumentation, both in-plane permeability and porosity can be simultaneously estimated. The feasibility of the proposed method was illustrated by experiments and verified with numerical simulations.

International trends in health science librarianship Part 10: The Greater China area

This is the 10th in a series of articles exploring international trends in health science librarianship. This issue describes developments in health science librarianship in the first decade of the 21st century in China, Hong Kong and Taiwan. The next issue will report on Japan and South Korea. JM.

Normal-sized ovarian papillary serous carcinoma: a case report

A normal-sized ovarian papillary serous carcinoma is rare. We present the case of a 46-year-old woman with progressive abdominal fullness of one week's duration. The medical evaluation revealed abdominal carcinomatosis with normal-sized ovaries and an elevated serum CA-125 level of 147,365.8 U/ml. Cytoreductive surgery (hysterectomy, bilateral salpingo-oophorectomy, omentectomy, lymphadenectomy, infracolic omentectomy, peritoneal biopsy, washing cytology, and appendectomy) was performed. The histologic examination revealed an ovarian serous papillary carcinoma. Adjuvant chemotherapy was administered. The serum CA-125 level decreased after completion of treatment. Normal-sized ovarian serous surface papillary carcinomas should be kept in mind as an origin of disease in patients who have peritoneal carcinomatosis, which sometimes is a diagnostic dilemma of the disease source. We report this case to emphasize the clinical symptoms and importance of the early and accurate diagnosis of a normal-sized ovarian papillary serous carcinoma.

A novel defense mechanism that is activated on amyloid-beta insult to mediate cell survival: role of SGK1-STAT1/STAT2 signaling

Amyloid-beta (Abeta) is known to induce apoptotic cell death and its underlying mechanism has been studied extensively, but the endogenous protection mechanism that results from Abeta insult is less known. In this study, we have found that Abeta(1-42) produced a dose-dependent decrease in cell viability and dose-dependent increase in apoptotic cell death in PC12 cells. Meanwhile, Abeta(1-42) (0.1 muM) increased the phosphorylation of serum- and glucocorticoid-inducible kinase1 (SGK1) at Ser-78 specifically. A parallel increase in ERK1/2, STAT1 and STAT2 phosphorylation and the anti-apoptotic gene Mcl-1 expression was also observed. Transfection of rat siRNAs against ERK1/2, SGK1, STAT1 and STAT2 abolished these effects of Abeta. Transfection of sgkS78D, the constitutively active SGK1, dose-dependently protected against Abeta-induced apoptosis and dose-dependently increased the expression of Mcl-1. SGK1 activation further phosphorylates STAT1 at Tyr-701 and Ser-727 directly, and activates STAT2 at Tyr-690 indirectly. Phosphorylation of STAT1/STAT2 upregulated Mcl-1 expression which in turn protected against Abeta-induced apoptosis. But Mcl-1 siRNA transfection enhanced Abeta-induced apoptosis. Mutation of SGK1 at Ser-78 blocked the effect of Abeta on STAT1/STAT2 phosphorylation and Mcl-1 expression. Further, mutation of STAT1/STAT2 prevented the effect of both Abeta and SGK1 on Mcl-1 expression. These results together showed a novel endogenous protection mechanism that is activated on Abeta insult to mediate cell survival.

Hypoxic preconditioning attenuated in kainic acid-induced neurotoxicity in rat hippocampus

The neuroprotective effect of hypoxic preconditioning on kainate (KA)-induced neurotoxicity, including apoptosis and necrosis, was investigated in rat hippocampus. Female Wistar-Kyoto rats were subjected to 380 mm Hg in an altitude chamber for 15 h/day for 28 days. Intrahippocampal infusion of KA was performed in chloral hydrate anesthetized rats, which acutely elevated 2,3-dihydroxybenzoic acid levels in normoxic rats. Seven days after the infusion, KA increased lipid peroxidation in the infused hippocampus and resulted in hippocampal CA3 neuronal loss. A 4-week hypoxic preconditioning attenuated KA-induced elevation in hydroxyl radical formation and lipid peroxidation as well as KA-induced neuronal loss. The effects of hypoxic preconditioning on KA-induced apoptosis and necrosis were investigated further. Two hours after KA infusion, cytosolic cytochrome c content was increased in the infused hippocampus. Twenty-four hours after KA infusion, pyknotic nuclei, cellular shrinkage, and cytoplasmic disintegration, but not TUNEL-positive staining, were observed in the CA3 region of hippocampus. Forty-eight hours after KA infusion, both DNA smear and DNA fragmentation were demonstrated in the infused hippocampus. Furthermore, TUNEL-positive cells, indicative of apoptosis, in the infused hippocampus were detected 72 h after KA infusion. Hypoxic pretreatment significantly reduced necrotic-like events in the KA-infused hippocampus. Moreover, hypoxic preconditioning attenuated apoptosis induced by KA infusion, including elevation in cytosolic cytochrome c content, TUNEL-positive cells, and DNA fragmentation. Our data suggest that hypoxic preconditioning may exert its neuroprotection of KA-induced oxidative injuries via attenuating both apoptosis and necrosis in rat hippocampus.

Hydrogen peroxide increases the activity of rat sympathetic preganglionic neurons in vivo and in vitro

Reactive oxygen species (ROS) have been shown to modulate neuronal synaptic transmission and have also been implicated in cardiovascular diseases such as hypertension. The hypothesis that H(2)O(2) acting on sympathetic preganglionic neurons (SPNs) affects spinal sympathetic outflow was tested in the present study. H(2)O(2) was applied intrathecally via an implanted cannula to the T7-T9 segments of urethane-anesthetized rats. Blood pressure and heart rate were used as indices to evaluate the spinal sympathetic effects of H(2)O(2) in vivo. Intrathecal H(2)O(2) (100-1000 nmol) dose-dependently increased both the mean arterial pressure and heart rate. Reproducible pressor effects of H(2)O(2) (1000 nmol) applied consecutively at intervals of 30 min were observed. The pressor effects of intrathecal H(2)O(2) (1000 nmol) were attenuated by pretreatment with intrathecal administration of catalase (500 units), or N-acetyl-cysteine (1000 nmol). The pressor effects of intrathecal H(2)O(2) (1000 nmol) were also antagonized dose-dependently by prior intrathecal injection of AP-5 (DL-2-amino-5- phosphonovaleric acid, 10 and 30 nmol), or 6-cyano-7- nitroquinoxaline-2,3-dione, 10 and 30 nmol. In vitro electrophysiological study in spinal cord slices showed that superfusion of 1 mM H(2)O(2) for 3 min, which had no effect on membrane potential, caused an increase in amplitude of excitatory postsynaptic potentials in SPNs, but had little effect on that of inhibitory postsynaptic potentials. Taken together, these results demonstrated that oxidative stress in spinal cord may cause an increase in spinal sympathetic tone by acting on SPNs, which may contribute to ROS-induced cardiovascular dysfunction.

Acute exposure to trichloroethylene differentially alters the susceptibility to chemoconvulsants in mice

The effects of a common industrial solvent, trichloroethylene (TCE), which was once used as an anesthetic agent but its in vivo mechanism is still unknown, on convulsant-induced seizures in mice were examined. Pretreatment with TCE (250-2000 mg/kg, i.p.) significantly increased pentylenetetrazol (PTZ)-, picrotoxin (PIC)-, bicuculline (BIC)-, strychnine (STY)-, 4-aminopyridine (4-AP)- and N-methyl-D-aspartate (NMDA)-induced convulsion thresholds and lethal doses. However, the increase in convulsion thresholds and lethal doses was much greater for GABAergic antagonists (PIC, BIC, and PTZ) than non-GABAergic convulsants (STY, 4AP, and NMDA) following 2000 mg/kg TCE administration. Pre-treatment of mice with disulfiram (an inhibitor of CYP 4502E1) but not 4-methyl pyrazole (an inhibitor of alcohol dehydrogenase) significantly prolonged the time required for TCE (5000 mg/kg, i.p.) to induce the loss of righting reflex. These results suggest that acute exposure to TCE differentially alters the susceptibility to chemically induced convulsions in mice. The anticonvulsive effect of TCE may be predominantly mediated by GABA(A) receptors. In addition, TCE appears to exert a direct anesthetic effect.

Ethanol effects on nitric oxide production in cerebral pial cultures

BACKGROUND

Although alcohol abusers are known to have higher incidences of hemorrhagic cerebrovascular diseases, it is not known whether these changes are associated with ethanol (EtOH) action on nitric oxide (NO) production in the cerebrovascular cells. The purpose of this study was to examine the effects of EtOH treatment on basal and cytokine-induced NO production in cortical pial cultures.

METHODS

Cell cultures for this study included murine primary pial vascular cells, primary glial cells and cortical neurons. These cells were exposed to cytokines or EtOH for 24 to 48 hr. The culture media were used for measurement of nitrite, as an indication for NO release, and lactate dehydrogenase (LDH), as an index of cell membrane integrity. In addition, immunocytochemical determinations were carried out to identify cell types and to assess inducible nitric oxide synthase (iNOS).

RESULTS

Exposure of primary pial vascular cultures to cytokines that consisted of interleukin-1 beta (IL-1 beta; 250 pg/mL) and interferon-gamma (IFNgamma; 2 ng/mL) or to EtOH (50 to 100 mM) for 24 to 48 hr significantly elevated NO production. NO production could be attenuated by N-nitro-L-arginine (N-arg), a nonspecific NOS inhibitor, or aminoguanidine (AG), an iNOS inhibitor. Increased iNOS immunoreactivity was observed in cytokines- or EtOH-treated pial cells. When pial cells were cocultured with cortical neurons, prolonged EtOH exposure led to a large increase in NO production as well as LDH release. However, this increase was not observed in pial culture alone or in mixed cortical culture. Nevertheless, inhibition of NO production with N-arg or AG did not alter the EtOH-induced LDH release in the pial cells cocultured with cortical neurons.

CONCLUSION

These results show that EtOH exposure led to increased production of NO in primary pial cell culture. In mixed culture that contained cortical neurons and pial cells, EtOH induced increase in NO as well as LDH release, which is an indication of loss of cell membrane integrity. However, EtOH-mediated LDH release in mixed cortical pial cultures was not a consequence of the increase in NO production by these cells. Studies that use mixed cortical-pial cultures may provide a unique in vitro system for examining the interactions among glial cells, neurons, and cerebrovascular cells.

Perinatal outcome of oligohydramnios without associated premature rupture of membranes and fetal anomalies

To investigate the perinatal outcome of patients with oligohydramnios (amniotic fluid index < or = 5 cm), but without premature rupture of membranes and fetal congenital anomalies, data from 245 singleton pregnancies were analyzed and compared to those with normal amniotic fluid volumes (5 < amniotic fluid index < 24 cm, n=27,261). Significantly higher incidences of primiparity, pregnancy-induced hypertension, premature separation of placenta, past history of intrauterine fetal death, past history of preterm delivery, postterm pregnancy, and advanced maternal age were noted to be associated with the occurrence of oligohydramnios. Pregnancies complicated by a markedly diminished amniotic fluid volume assessed antenatally by ultrasound were significantly more frequently associated with adverse perinatal outcomes such as preterm delivery, low or very low birth weight, low Apgar scores, intrauterine fetal death, small-for-gestational-age newborns, meconium staining, cesarean delivery, neonatal intensive care, and neonatal death.

Risk factors for pre-eclampsia in an Asian population

OBJECTIVE

To identify the risk factors for pre-eclampsia in an Asian population.

METHOD

We conducted a retrospective cohort study involving 29375 Taiwanese women who delivered between July 1990 and September 1998, excluding pregnancies complicated by chronic hypertension or fetal malformations.

RESULT

Four hundred and fifteen women had pre-eclampsia (1.4%). Women who had a history of pre-eclampsia (OR 6.3, 95% CI 4.4, 9.2), multiple gestation (OR 3.6, 95% CI 2.4, 5.5), a prepregnancy BMI > 24.2 kg/m(2) (OR 2.4, 95% CI 1. 8, 3.1), were > 34 years of age (OR 1.8, 95% CI 1.4, 2.4), nulliparous (OR 1.3, 95% CI 1.2, 1.5), had urinary tract infection (OR 4.8, 95% CI 1.5, 15.8), or worked during pregnancy (OR 1.9, 95% CI 1.4, 2.4) were at increased risk of pre-eclampsia.

CONCLUSION

Some of the risk factors for pre-eclampsia among Asian women are the same as those of other ethnic groups, whereas some of the risk factors are different.

Arecoline excites rat locus coeruleus neurons by activating the M2-muscarinic receptor

The action of arecoline on rat locus coeruleus neurons was studied by intracellular recording from the in vitro brain slice preparation. Superfusion of arecoline (0.1-100 microM) caused two dose-related effects, an increased firing rate and, in neurons previously hyperpolarized to a constant potential by passing a steady hyperpolarizing current across the membrane, depolarization. Both effects were associated with a reduction in membrane input resistance. Moreover, the arecoline-induced excitatory effects were antagonized by the muscarinic receptor antagonist, atropine, but not by the nicotinic receptor antagonist, hexamethonium. Methoctramine, a selective M2-muscarinic receptor antagonist, was also effective in reversing the arecoline-induced effects, with a dissociation equilibrium constant of 14.2+/-1.2 nM (n=6). These results therefore suggest that arecoline exerts its excitatory actions by binding to M2-muscarinic receptors on the cell membrane of neurons of the locus coeruleus.

Activation of rat locus coeruleus neuron GABA(A) receptors by propofol and its potentiation by pentobarbital or alphaxalone

The action of propofol on the rat locus coeruleus was examined using intracellular recording from in vitro brain slice preparations. Concentrations of propofol between 3 and 300 microM were tested. At 100 microM, propofol completely inhibited the firing of all neurons tested (n=34); this was associated with a 5.7-mV hyperpolarization (range 0-16 mV, n=33) and a 35.6% reduction in input resistance (range 7.3-66.1%, n=33). The propofol-induced responses were not affected by 2-hydroxysaclofen (50 microM) or BaCl(2) (300 microM), but were completely blocked by bicuculline methiodide (100 microM) or picrotoxin (100 microM), indicating that propofol acts on GABA(A) receptors. As assessed by inhibition of the spontaneous firing rate, propofol was 5.6-fold more potent than GABA (gamma-aminobutyric acid). Potentiation of the propofol effect by other general anesthetics or other drugs was also investigated. When pentobarbital (100 microM) was tested alone on locus coeruleus cells, no change in membrane potential or input resistance was seen and there was only a 20.3+/-7.2% (n=8) inhibition of firing rate; however, in combination with 30 microM propofol, it caused a 6.1-fold greater increase in membrane hyperpolarization and a 9.7-fold greater reduction in input resistance than 30 microM propofol alone. A relatively low concentration of alphaxalone (10 microM), when tested alone, had little effect on the membrane potential or input resistance and only produced a 46.0+/-8.9% (n=8) inhibition of firing rate; however, in combination with 30 microM propofol, it caused a 9.3-fold greater hyperpolarization and an 8.6-fold greater reduction in input resistance compared with 30 microM propofol alone. In contrast, diazepam caused no potentiation of either propofol- or GABA-induced responses. Our data also indicate that locus coeruleus neuron GABA(A) receptors possess distinctive pharmacologic characteristics, such as blocking of the propofol effects by zinc and insensitivity to diazepam and the direct action of pentobarbital. On the basis of these pharmacologic properties, we suggest that locus coeruleus neuron GABA(A) receptors do not contain the gamma subunit.

Effect of panax notoginseng extracts on inferior sperm motility in vitro

The purpose of this study was to investigate the effects of Panax notoginseng extracts on inferior sperm motility in vitro. Semen samples were collected from 23 patients with sperm motility between 20% and 40%. The sperm count was over 20 x 10(6)/ml in accordance with the World Health Organization standard. 1.0 mg/ml and 2.0 mg/ml of Panax notoginseng extracts including aqueous extract, n-butanol extract, and polysaccharide fraction on sperm motility and progression were evaluated by computer assisted semen analysis. The results demonstrated that sperm motility as well as progression on inferior sperm motility were enhanced at 1 hour and 2 hours after incubation with all three types of extracts.

Acute pentylenetetrazol injection reduces rat GABAA receptor mRNA levels and GABA stimulation of benzodiazepine binding with No effect on benzodiazepine binding site density

The effects of a single convulsive dose of pentylenetetrazol (PTZ, 45 mg/kg i.p.) on rat brain gamma-aminobutyric acid type A (GABAA) receptors were studied. Selected GABAA receptor subunit mRNAs were measured by Northern blot analysis (with beta-actin mRNA as a standard). Four hours after PTZ, the GABAA receptor gamma2-mRNA was decreased in hippocampus, cerebral cortex, and cerebellum; alpha1-mRNA was decreased in cerebellum; and beta2 subunit mRNA was decreased in cortex and cerebellum. The alpha5 subunit mRNA level was not altered. Those mRNAs that had been reduced were increased in some brain regions at the 24-h time point, and these changes reverted to control levels by 48 h. PTZ effect on GABAA receptors was also studied by autoradiographic binding assay with the benzodiazepine agonist [3H]flunitrazepam (FNP), the GABAA agonist [3H]muscimol, and the benzodiazepine antagonist [3H]flumazenil. There was an overall decrease in [3H]FNP binding 12 but not 24 h after PTZ treatment. In contrast, [3H]muscimol binding was minimally affected, and [3H]flumazenil binding was unchanged after PTZ treatment. Additional binding studies were performed with well-washed cerebral cortical homogenates to minimize the amount of endogenous GABA. There was no PTZ effect on specific [3H]FNP binding. However, there was a significant reduction in the stimulation of [3H]FNP binding by GABA. The results showed that an acute injection of PTZ caused transient changes in GABAA receptor mRNA levels without altering receptor number but affected the coupling mechanism between the GABA and benzodiazepine sites of the GABAA receptor.

Structure-activity relationships of naturally occurring and synthetic opioid tetrapeptides acting on locus coeruleus neurons

Intracellular recording was used to study the effects of eight opioid tetrapeptides with similar amino acid sequences, namely endomorphin-1 (Tyr-Pro-Trp-Phe-NH2), endomorphin-2 (Tyr-Pro-Phe-Phe-NH2), morphiceptin (Tyr-Pro-Phe-Pro-NH2), hemorphin-4 (Tyr-Pro-Trp-Thr), Tyr-MIF-1 (Tyr-Pro-Leu-Gly-NH2), Tyr-W-MIF-1 (Tyr-Pro-Trp-Gly-NH2), TAPS (Tyr-D-Arg-Phe-Sar) and DALDA (Tyr-D-Arg-Phe-Lys-NH2), on neurons of the rat locus coeruleus, using a submerged brain slice preparation. All the tetrapeptides inhibited the spontaneous firing of all neurons of the locus coeruleus tested. Higher concentrations also caused hyperpolarization of the neurons and a reduction in input resistance. These inhibitory effects were rapidly and completely reversed by CTAP (D-Phe-Cys-Tyr-D-Trp-Arg-Thr-Pen-Thr-NH2, a selective micro-opioid receptor antagonist). The IC50 of the opioid tetrapeptides, in terms of inhibition of spontaneous firing of locus coeruleus neurons, as compared to the concentrations which produced a 5-mV hyperpolarization (HC5 mV) were calculated, giving the same rank order of potency: TAPS (IC50 = 1.9 nM, HC5 mV = 3.4 nM) > endomorphin-1 (IC50 = 8.8 nM, HC5 mV = 22.1 nM) and endomorphin-2 (IC50 = 5.3 nM, HC5 mV = 16.1 nM)> DALDA (IC50 = 20 nM, HC5 mV = 143 nM) > morphiceptin (IC50 = 65 nM, HC5 mV = 335 nM) > Tyr-W-MIF-I (IC50 = 3.8 microM, HC5 mV = 6.7 microM) > hemorphin-4 (IC50 = 6.7 microM, HC5 mV = 36.9 microM) > Tyr-MIF-1 (IC50 = 37.5 microM, HC5 mV = 76.2 microM). Comparison of the ability of endomorphin-1 and endomorphin-2 to inhibit spontaneous firing based on single-cell recordings (n = 5) showed these two peptides to be equipotent. Based on these results, the structure-activity relationships of these opioid tetrapeptides are discussed herein.

Tumor vascular pattern and blood flow impedance in the differential diagnosis of leiomyoma and adenomyosis by color Doppler sonography

PURPOSE

Our objective was to evaluate the differences between leiomyoma and adenomyosis by color Doppler sonography with new criteria.

METHODS

A total of 78 patients with symptomatic uterine nodularities who were sonographically suspected to have leiomyoma or adenomyosis without other coexisting pathologic conditions was enrolled in the study. All patients underwent transvaginal color Doppler sonography (7.0-MHz vaginal probe) or transabdominal color Doppler sonography (5.0 MHz) during the early follicular phase. The morphology, tumor vascular pattern, and blood flow impedance of the uterine tumors were measured. All of the patients underwent surgery and the pathologic reports were used as references.

RESULTS

The mean age was not statistically significant in patients with adenomyosis versus leiomyoma (P > 0.05). The morphologic criteria for adenomyosis and leiomyoma by sonography detected 79% of adenomyosis and 84% of leiomyoma. Adenomyosis had 87% randomly scattered vessels or intratumoral signals and 88% of leiomyomas showed peripheral scattered vessels or outer feeding vessels. Eighty-two percent of adenomyosis had a pulsitility index (PI) of arteries within or around uterine tumors > 1.17 and 84% of leiomyomas had a PI < or = 1.17. The reliability test of tumor vascular pattern and blood flow impedance were better than that of using morphological criteria alone.

CONCLUSIONS

With the aid of color Doppler sonography, tumor vascular pattern and blood flow impedance of the arteries within or around uterine tumors could more accurately diagnose adenomyosis and leiomyoma in addition to the morphologic criteria on transvaginal sonography.

Risk factors for placenta accreta

OBJECTIVE

To identify risk factors associated with placenta accreta in a large cohort study.

METHODS

Data for this study came from the Taiwan Down Syndrome Screening Group, an ongoing project on feasibility of serum screening in an Asian population. Women who had serum screening for Down syndrome at 14-22 weeks' gestation using alpha-fetoprotein (AFP) and free beta-hCG between January 1994 and June 1997, and delivered in the same institution, were included (n = 10,672). Those who had multiple gestations (n = 200), overt diabetes (n = 11), or fetal malformations (n = 101) were excluded. If a woman was involved more than once, one randomly selected pregnancy was included in the analysis (n = 9349). Twenty-eight pregnancies were complicated by placenta accreta, diagnosed by clinical presentation (n = 26) or histologic confirmation (n = 2). Multiple logistic regression with adjustment for potentially confounding variables was used to identify independent risk factors for placenta accreta.

RESULTS

Women who had placenta previa (odds ratio [OR] 54.2; 95% confidence interval [CI] 17.8, 165.5) and second-trimester serum levels of AFP and free beta-hCG greater than 2.5 multiples of the median (OR 8.3; 95% CI 1.8, 39.3 and OR 3.9; 95% CI 1.5, 9.9, respectively), and were 35 years and older (OR 3.2; 95% CI 1.1, 9.4) were at increased risk of having placenta accreta.

CONCLUSION

Risk factors for placenta accreta include placenta previa, abnormally elevated second-trimester AFP and free beta-hCG levels, and advanced maternal age.

Decreased benzodiazepine binding with little effect on gamma-aminobutyric acid binding in rat brain after treatment with antisense oligodeoxynucleotide to the gamma-aminobutyric acidA receptor gamma-2 subunit

Benzodiazepine potentiation of gamma-aminobutyric acid (GABA) neurotransmission is associated with the presence of a gamma-2 subunit in the GABAA receptor. A method was developed to modify the gamma-2 subunit expression in adult rat brain. Unilateral intracerebroventricular (i.c.v.) infusion of a 17-base phosphorothioate-modified antisense oligodeoxynucleotide (ASO) was performed every 12 hr for 3 days. Controls were treated with a sense oligodeoxynucleotide. Parasagittal brain sections were used for quantitative autoradiographic analysis of radioligand binding. ASO treatment caused a 15% to 25% decrease of specific [3H]flunitrazepam binding in most brain areas, with statistically significant decreases in frontal cortex, cerebellar molecular layer, zona reticulata of substantia nigra and CA3 of hippocampus. In contrast, [3H]muscimol binding was not changed. [3H]GABA binding was also unchanged, except for a 10% decrease in cerebellar granule cell layer. The effect on the chloride channel of the GABAA receptor complex was examined by 4'-ethynyl-4-n-[2, 3-3H2]propylbicycloorthobenzoate binding; most brain areas showed small decreases in 4'-ethynyl-4-n-[2, 3-3H2]propylbicycloorthobenzoate binding. However, hippocampal regions showed much larger decreases. Binding of the adenosine A1 receptor antagonist [3H]8-cyclopentyl-1,3-dipropylxanthine was used to examine possible secondary effects of the ASO. There was a decrease in [3H]8-cyclopentyl-1,3-dipropylxanthine binding, but this was much smaller than the change in [3H]flunitrazepam binding, and no area showed a significant effect. Quantitative immunoblotting with a monoclonal antibody that recognizes GABAA receptor beta-2 and beta-3 subunits showed no change in immunoreactivity in cerebellar tissue after ASO treatment. The results indicate a selective effect on benzodiazepine binding to GABAA receptors and a possible change in receptor subunit composition.

Primary hyperparathyroidism in pregnancy--report of 3 cases

Three cases of primary hyperparathyroidism in pregnancy are described. Patient 1 developed left thigh pain and lower abdominal pain at 34 weeks' gestation. Patient 2 had right flank pain and lower abdominal pain at 32 weeks' gestation. Both patients accepted medical therapy initially, which resulted in poor control of hypercalcemia. Patient 1 delayed her parathyroidectomy until the postpartum period; she had maternal hypercalcemia and neonatal hypocalcemia. Patient 2 accepted parathyroidectomy at 32 weeks' gestation with an uneventful outcome for both mother and baby. Patient 3 was asymptomatic; her hyperparathyroidism was diagnosed postpartum after neonatal hypocalcemia and agreed to parathyroidectomy. All 3 patients had a parathyroid adenoma.

Electrochemical studies of the effects of substance P on dopamine terminals in the rat striatum

The purpose of this study was to investigate the regulation of dopamine (DA) release and clearance by Substance P (SP) in striatum. In vivo high speed chronoamperometric recording techniques, with Nafion-coated carbon-fiber electrodes, were used to evaluate extracellular DA concentrations in urethane-anesthetized Sprague-Dawley rats. SP was locally applied to striatum. Our data indicate that SP can induce DA release in striatum. However, only about half of the striatal sites respond to SP. Readministration of SP to the same site elicited a smaller DA release. These data suggest that SP-evoked release shows tachyphyllaxis and is heterogeneous in the striatum. Lesioning of DA neurons with 6-OHDA into the medial forebrain bundle abolished DA release induced by SP. It has been shown that SP interacts with three different tachykinin receptors. We found that application of the Neurokinin-1 (NK1) agonist [Sar9, Met (O2)11]SP, but not the NK3 agonist senktide, induced DA release, suggesting that SP-induced DA release may be mediated through NK1 receptors. We further examined SP effects on DA clearance in striatum. We found that pretreatment with SP significantly attenuated extracellular levels of DA after exogeneous application of DA, suggesting that DA clearance is augmented by SP. Taken together, our data demonstrate that substance P facilitates dopamine release and clearance in the striatum.

Electrophysiological and behavioral effects of Tyr-D-Arg-Phe-Sar on locus coeruleus neurons of the rat

The effect of Tyr-D-Arg-Phe-Sar (TAPS), a mu-selective tetrapeptide analog of dermorphin, was studied in the rat both in vitro, using slices of the locus coeruleus, and in vivo, after microinjection into the locus coeruleus. In electrophysiological studies, TAPS (1-100 nM) was able to inhibit spontaneous firing, cause hyperpolarization of the membrane potential and reduce the input resistance of neurons of the locus coeruleus, suggesting that there was an effect on the potassium channels. Based on the inhibition of the spontaneous firing rate, the average IC50 for TAPS was calculated to be 1.9 nM, a value lower than that reported for dermorphin or morphine. The TAPS-induced effects were antagonized by naloxone, with a dissociation equilibrium constant of 1.96 +/- 0.14 nM. The results indicate that TAPS binds to mu-opioid receptors on the cell membrane of neurons of the locus coeruleus to cause its inhibitory actions. In behavioral study, TAPS was microinjected bilaterally via chronically implanted cannulae into the locus coeruleus of non-anesthetized rats and its effects on locomotor activity determined. TAPS, at concentrations of 1 microM and 10 microM, but not of 0.1 microM, induced hypolocomotion/sedation and the effect was significantly reversed by naloxone (5 mg/kg i.p.). Taken together, these data suggest that TAPS has an inhibitory effect on neurons of the locus coeruleus and produces hypolocomotive/sedative effects in vivo.

Striatal glutamate release is important for development of ischemic damage to striatal neurons during rat heatstroke

This study attempted to ascertain whether heatstroke-induced ischemia is associated with augmented striatal glutamate release and can be attenuated by NMDA receptor antagonists. Mean arterial pressure (MAP), striatal cerebral blood flow (CBF), striatal glutamate release and striatal neuronal damage score were assessed in saline-treated rats and in rats treated with NMDA receptor antagonists. Heatstroke was induced by exposing the animals to a high ambient temperature; the moment at which MAP and CBF began to decrease from their peak levels was taken as the onset of heatstroke. During onset of heatstroke, rats displayed higher values of colonic temperature, striatal glutamate release and striatal neuronal damage score, and lower values of MAP and striatal blood flow compared with normothermic control rats. The decreased MAP, the diminished striatal blood flow, the augmented striatal glutamate release and the increased striatal neuronal damage score during onset of heatstroke were significantly attenuated by pretreatment with an NMDA receptor antagonist such as MK-801 or ketamine. In addition, the survival time (interval between onset of heatstroke and death) of the rats was extended by pretreatment with one of these two NMDA receptor antagonists. These results suggest that marked accumulation of glutamate in the striatum is important for the development of ischemic damage to striatal neurons during the onset of heatstroke.

Rupture of rudimentary horn pregnancy: a case report

A rare case of rupture of a noncommunicating rudimentary horn pregnancy is presented. The pregnancy continued to 16-weeks' gestation, when the rudimentary horn ruptured. The patient had signs and symptoms of massive hemoperitoneum. An emergency exploratory laparotomy revealed a ruptured rudimentary horn and an intact amnionic sac. Prompt excision of the rudimentary horn was performed. The relative literature and factors associated with a rudimentary horn pregnancy are reviewed and discussed.

The antral follicle count predicts the outcome of pregnancy in a controlled ovarian hyperstimulation/intrauterine insemination program

PURPOSE

Our purpose was to test whether age-related changes in antral follicle counts can predict the pregnancy outcome in the early follicular phase of a controlled ovarian hyperstimulation/intrauterine insemination (COH/IUI) program.

METHODS

A selected group of 107 women (36 healthy women requesting child sex preselection, 52 women with unexplained infertility, and 19 with minimal endometriosis) who underwent controlled ovarian hyperstimulation with clomiphene citrate (CC) plus human menopausal gonadotrophin (hMG) and subsequent intrauterine insemination were enrolled in the study. Transvaginal ultrasonography (7.0 MHz) was used to determine the total number of antral follicles (2-8 mm) in the right and left ovaries. The association among the antral follicle count, age, dominant follicle, and estradiol (E2) level on the day of human chorionic gonadotropin (hCG) was analyzed. The association of the pregnancy rate and OHSS with the antral follicle count, dominant follicle count, and age was also examined.

RESULTS

The total antral follicle number decreased with age (P < 0.0001). Dominant follicle number increased with total antral follicle number in women who received CC plus hMG/ IUI(P < 0.0001). The pregnant group had a higher number of antral follicle and dominant follicles in comparison with the nonpregnant group (P < 0.01 and P < 0.02, respectively). The E2 level on the day of hCG injection increased positively with the total number of antral follicles (P < 0.0001) and the total number of dominant follicles (P < 0.0001). In women aged younger than 35 years, the pregnancy rate and dominant follicle number rose as the number of antral follicles increased (P < 0.03 and P < 0.0001, respectively). The pregnancy rate was low (2/39) in women aged older than 35 years regardless of the number of antral follicles (P < 0.05) and the extent of hMG administration (P < 0.02). Women aged older than 35 also produced fewer dominant follicles (P < 0.001). No pregnancy was achieved in a patient with an antral follicle number of less than five (17 cases).

CONCLUSIONS

Age-related changes in antral follicle count significantly predicted the dominant follicle count and the pregnancy outcome. In women with antral follicle counts of less than five or who are older than 35 years, the application of COH/IUI may not be indicated.

Hypoxia-induced differential electrophysiological changes in rat locus coeruleus neurons

The effects of hypoxia on rat locus coeruleus (LC) neurons were investigated by intracellular recording from in vitro brain slices. In response to a brief exposure to hypoxic medium (2-5 min), equilibrated with 95% N2 - 5% CO2, two populations of cells could be distinguished, type 1 neurons (61%), showing hyperpolarization (9.3 +/- 0.4 mV, n = 125) and cessation of spontaneous action potentials, and type 2 neurons (39%), displaying gradual pure depolarization (6.0 +/- 0.3 mV, n = 80), instead of hypoxic hyperpolarization. Both types of response were associated with a reduction in membrane input resistance (34 +/- 1% for type 1 cells, n = 125, and 21 +/- 2% for type 2 cells, n = 68). While both types of neurons share similar electrophysiological properties, their membrane input resistance differ significantly (type 1 cells: 144 +/- 5 M omega, n = 125; type 2 cells: 183 +/- 9 M omega, n = 80, p < 0.001). These responses were compared to cyanide-induced chemical hypoxia. Cyanide (2 mM) induced the identical membrane response as effected by nitrogen hypoxia. All cells which responded to nitrogen-saturated hypoxic medium with a pure depolarizing response gave a similar response to cyanide and all neurons hyperpolarized by cyanide were also hyperpolarized by hypoxic medium. Moreover, the K(ATP) channel opener, diazoxide (1 mM), could mimic the hypoxia-induced hyperpolarization in type 1 neurons (10.6 +/- 0.9 mV, n = 18), but was unable to induce hyperpolarization in type 2 cells (n = 13). In addition, the N2-hypoxia-induced hyperpolarization was completely blocked by tolbutamide (200 microM, n = 8) or glibenclamide (3 microM, n = 9). These results indicate that a brief period of hypoxia evokes two different responses in LC neurons and this may be due to the heterogeneous distribution of K(ATP) channels among different LC neurons.

Opioid and antiopioid actions of Tyr-MIF-1, Tyr-W-MIF-1 and hemorphin-4 on rat locus coeruleus neurons: intracellular recording in vitro

Intracellular recording was used to study the effects of naturally occurring opioid tetrapeptides, including Tyr-Pro-Leu-Gly-NH2 (Tyr-MIF-1), Tyr-Pro-Trp-Gly-NH2 (Tyr-W-MIF-1), and Tyr-Pro-brain slice preparation. These tetrapeptides which, like other opioids, caused inhibitory effects on all LC neurons tested. Tyr-MIF-1 (10-100 microM), Tyr-W-MIF-1 (1-10 microM) and hemorphin-4 (1-30 microM) caused dose-related inhibition of the spontaneous firing. The IC50 were 37.5, 3.8 and 6.7 microM for Tyr-MIF-1, Tyr-W-MIF-1 and hemorphin-4, respectively. In addition, these tetrapeptides were tested for their blocking effects on the Tyr-D-Arg-Phe-sarcosine-OH (TAPS)-induced inhibitory actions. The results showed that Tyr-MIF-1, Tyr-W-MIF-1 and hemorphin-4 significantly decreased the actions of lower concentration of TAPS (30 nM), but did not decrease the actions of higher concentration of TAPS (100 nM). It is concluded that the blood-derived peptide hemorphin-4 and the endogenous peptides Tyr-W-MIF-1 and Tyr-MIF-1 possess opioid and antiopioid actions in the LC neurons.

Prenatal diagnosis of congenital cystic adenomatoid malformation of the lung: four cases report

Congenital cystic adenomatoid malformation of the lung (CCAML) is a rare pulmonary lesion, characterized by excessive overgrowth of the terminal respiratory bronchioles. Prenatal detection and serial sonographic study of fetuses with CCAML can provide information about the natural history of these lesions and reveal most of the nature history of pathophysiologic features which are likely to affect the clinical outcome. This information is crucial to the formulation of a prognosis and a management strategy. We report on four cases of CCAML, three of which involved macrocystic lesions including two cases of type I and one case of type II. Only one microcystic lesion, a type III CCAML, was identified in these patients. All of the cases were diagnosed by ultrasound between the 21 and 24 weeks of gestation. Fetal hydropic change was noted in all four cases. All of the parents opted for termination of pregnancy before fetal viability. Post-mortem examination confirmed the diagnosis in all four cases.

Effects of glucose on placental hormones in the human term placenta in vitro

Glucose intake during pregnancy results in a decrease in endogenous insulin-like growth factor binding protein-1 (IGFBP-1). However, the exact role of glucose on placental secretion of IGFBP-1 is unclear. This study was designed to investigate the direct effects of glucose on the production of IGFBP-1 and other placental hormones, using an isolated placental preparation. Using the dual recirculating perfusion system for an isolated human placenta lobule, a total of 43 experiments were performed over a duration of 6 hours. Twenty placentae were perfused with a medium containing 141 +/- 10 mg/dL (7.83 +/- 0.56 mmol/L) glucose (group I) and 23 placentae with 242 +/- 12 mg/dL (13.43 +/- 0.67 mmol/L) glucose (group II). Levels of insulin, glucose, lactate, insulin-like growth factor (IGF-I), IGFBP-1, human placental lactogen (hPL) and beta-human chorionic gonadotropin (beta-hCG) were measured at 30 minute intervals during perfusion. Insulin and IGF-I were barely detectable in the perfusates and their levels were not modulated by glucose. IGFBP-1 was predominantly detected in the maternal rather than the fetal compartment of the placental circulation. Glucose increased the levels of IGFBP-1 in the maternal circulation in groups I and II during the first two hours of perfusion (188 +/- 58% and 193 +/- 31%, respectively). However, during the subsequent 4 hour period, the increase in IGFBP-1 concentration was significantly higher in group II (926 +/- 427%) than in group I (428 +/- 216%) (p < 0.05). There was no difference in the levels of hPL or beta-hCG between the two groups in the maternal circulation. Thus, glucose stimulates the production of IGFBP-1 in the maternal circulation of a placenta in vitro. This increase in IGFBP-1 by glucose in vitro, as opposed to the decrease of IGFBP-1 in vivo, may be due to a lack of circulatory maternal insulin in the isolated placental preparation. These results also suggest that there may be a functional barrier within the placenta that prevents an increase in the level of IGFBP-1 in the fetal circulation.

Treatment with an antisense oligodeoxynucleotide to the GABAA receptor gamma 2 subunit increases convulsive threshold for beta-CCM, a benzodiazepine "inverse agonist', in rats

The gamma 2 subunit of the gamma-aminobutyric acid type-A (GABAA) receptor is associated with the actions of benzodiazepines and related drugs. A phosphorothioate-modified antisense oligodeoxynucleotide directed against the gamma 2 subunit was given by i.c.v. injection (18 micrograms in 2 microliters saline) to male Sprague-Dawley rats every 12 h for 3 days. Controls received the corresponding sense oligodeoxynucleotide. 4-6 h after the last i.c.v. treatment, rats were given methyl-beta-carboline-3-carboxylate (beta-CCM), a benzodiazepine "inverse agonist', by slow i.v. infusion. Compared to naive rats, the beta-CCM threshold dose was not affected by the sense oligodeoxynucleotide, but was increased 87% in antisense oligodeoxynucleotide-treated rats. The treatment had no effect on the seizure threshold for picrotoxin. Both antisense and sense oligodeoxynucleotide treatments slightly increased the threshold for strychnine seizures. The results suggest that antisense oligodeoxynucleotide treatment altered GABAA receptor composition and interfered with the actions of a benzodiazepine receptor ligand in vivo, and may provide a tool for studying regulation of receptor structure and function.

Chronic exposure of neonatal cardiac myocytes to hydrogen peroxide enhances the expression of catalase

The adaptive response of antioxidant enzymes to oxidative stress in the heart has not been investigated. Because H2O2 is considered to play a major role in reperfusion injury to the heart, this study was undertaken to examine if H2O2 alters the expression of these enzymes in the rat neonatal myocytes. H2O2 was continuously generated by the addition of glucose oxidase to the culture medium. Both the activity and the mRNA for catalase were increased following incubation of neonatal myocytes with non-toxic concentrations of glucose oxidase. The induction of mRNA preceded the enhancement of activity, and both remained elevated after 24 h incubation. Nuclear run-on assay indicated that the transcriptional rate for catalase mRNA was increased. The same treatment did not alter the activities for total superoxide dismutase and Se-glutathione peroxidase. The results suggest that H2O2-induced expression of catalase was in part due to transcriptional activation. It further implies that the induction of catalase may play an important role in protecting hearts from ischemic/reperfusion injury.

Prenatal diagnosis of major congenital cardiovascular malformations

This prospective study was designed to determine whether there would be a higher incidence of congenital cardiovascular malformation (CCVM) in pregnant women with certain risk factors. Fetal echocardiography, from second trimester of term, was performed in 1,659 pregnant women with risk factors for CCVMs and 826 pregnant women without risk factors from March 1990 to April 1995. Two-dimensional imaging, fetal M mode measurements, Doppler waveform velocity and Doppler color flow mapping were used for fetal heart examination. During this period, 70 fetuses with major cardiovascular malformations were found. The prenatal detection rate was determined as 2.8% (70/2,485) in our study. The rate in the high-risk group, however, was 3.7% (61/1,659). Of all indications, fetal risk factors had the highest rate (9.3%, 46/494) of detected CCVMs. Maternal and familial indications could be excluded from the high-risk group as they did not show any increased incidence over the low-risk group. We suggest that fetal echocardiography is mandatory in the high-risk group, especially in cases with fetal and placental risk factors. Fetal cardiac screening in the hands of first-line sonographers has a major role in prenatal diagnosis of CCVMs in the low-risk group.

Antioxidant enzyme gene transcription in copper-deficient rat liver

Antioxidant enzymes, Cu/Zn- and Mn-superoxide dismutase, catalase, and glutathione peroxidase, constitute an important defense mechanism against cytotoxicity of reactive oxygen species. Copper is essential for the activity of Cu/Zn-superoxide dismutase. Oxidative stress, therefore, is expected in organs of rats fed copper-deficient diet due to reduced Cu/Zn-superoxide dismutase activity. Our previous studies have shown that the expression of antioxidant enzymes was altered in copper-deficient rat liver. The present report was undertaken to study further the transcription of these enzymes in liver nuclei of rats made copper-deficient for 4 weeks. While copper deficiency decreased the copper in liver by about 80%, it did not alter the copper content in liver nuclei. In spite of a 100% elevation in nuclear iron concentration, liver nuclei from copper-deficient rats showed normal appearance. The transcriptional rates for Cu/Zn-superoxide dismutase, glutathione peroxidase, and glyceraldehyde-3-phosphate dehydrogenase were not altered by dietary copper deprivation. In contrast, transcriptional rates for Mn-superoxide dismutase and beta-actin were increased but that for catalase was reduced in the nuclei isolated from the copper-deficient rat liver. These results suggest that oxidative stress, resulting from copper deficiency, differentially modulates the gene transcription for the antioxidant enzymes in rat liver.

Action of dexmedetomidine on rat locus coeruleus neurones: intracellular recording in vitro

The action of dexmedetomidine on rat locus coeruleus neurones was examined using intracellular recordings from the in vitro brain slice preparation. Concentrations of dexmedetomidine from 1 to 1000 nM were tested. At 30 nM, dexmedetomidine produced complete inhibition of firing of all neurones tested (n = 21); this was associated with a 13 mV hyperpolarization (range 2.2-29.7 mV, n = 21) and a 27% reduction in input resistance (range 11.1-46.2%, n = 17). The dexmedetomidine responses reached a plateau phase between 100 and 1000 nM. Based on single-cell recordings, the hyperpolarizing potency of dexmedetomidine was found to be 6 times greater than that of clonidine (n = 10). The reversal potential for the dexmedetomidine-induced hyperpolarization was -106.9 +/- 1.7 mV (n = 9), a value similar to the K+ equilibrium potential; hyperpolarization was blocked by both CsCl and BaCl2. The effect of dexmedetomidine was antagonized by yohimbine, with a dissociation equilibrium constant of 30 nM. In contrast, prazosin, the alpha 1-, alpha 2B- and alpha 2C-adrenoceptor subtype-preferring ligand, did not inhibit the dexmedetomidine effect. Our results also show that low concentrations of oxymetazoline (10-300 nM), an alpha 2A-adrenoceptor subtype-selective drug, cause profound inhibition of neuronal activity in the locus coeruleus. These data therefore suggest that dexmedetomidine binds to alpha 2A-adrenoceptors on the cell membrane of neurones of the locus coeruleus and that this leads to opening of the inwardly rectifying K+ channels, resulting in the observed hyperpolarization of the membrane.

Prenatal diagnosis of tetralogy of fallot by Doppler color flow mapping

The prenatal diagnosis of tetralogy of Fallot (TOF) can be difficult, as the routine sonographic four-chamber view may be normal before birth. Unlike the normal fetus, in which blood flows adjacent to the left side of the interventricular septum, on color Doppler mapping a fetus with TOF also demonstrates antegrade flow along the right side of the interventricular septum. This Y-shaped ventricular outflow passing through the dilated aortic tract is confluent at the level of the ventricular septal defect during the systolic phase. In the past 3 years, three cases of TOF have been diagnosed prenatally at the Chang Gung Memorial Hospital. In each case, the above picture was demonstrated. 2-Dimensional Doppler color flow mapping may be helpful in the prenatal diagnosis of TOF.

Rapid down-regulation of [3H]zolpidem binding to rat brain benzodiazepine receptors during flurazepam treatment

In a previous study, it was found that down-regulation of benzodiazepine (BZ) binding in rats treated 4 weeks with flurazepam was relatively greater and more widespread when measured with [3H]zolpidem, a selective 'BZ1 receptor' ligand, than that measured with the non-selective ligand, [3H]flunitrazepam. In the present study, the time course for down-regulation of [3H]zolpidem binding was studied in rats treated with flurazepam. [3H]Zolpidem binding was also studied in rats given a midazolam treatment shown to cause tolerance. Rats were chronically treated with flurazepam for 1 or 2 weeks, or with midazolam for 3 weeks, then killed immediately after the treatment. Another group of rats was acutely treated with desalkyl-flurazepam and killed 30 min later. After 2 weeks of flurazepam treatment, the Bmax of [3H]zolpidem binding was decreased by 22% in cerebral cortex, 26% in cerebellum and 33% in hippocampus, with no change in the Kd in any region. After 1 week of flurazepam treatment, the Bmax was decreased by 23% in cerebellum and 14% in hippocampus, but not changed in cerebral cortex. The Kd was increased in cerebral cortex, but not in cerebellum or hippocampus. Neither the Bmax nor the Kd of [3H]zolpidem binding was affected by acute desalkyl-flurazepam treatment, or by 3 weeks of midazolam treatment. These results, in combination with previous findings, which showed no change in [3H]flunitrazepam binding after 1 or 2 week flurazepam treatment, and no change in cerebellum even after the 4 week treatment, may indicate a shift in BZ receptor subtypes in flurazepam-tolerant rats.(ABSTRACT TRUNCATED AT 250 WORDS)

c-fos expression as a marker of central cardiovascular neurons

Immunohistochemical detection of Fos, the protein product of the immediate-early gene c-fos, was evaluated as a functional marker of central neurons sensitive to a change of blood pressure/blood volume. Controlled hemorrhage and infusion of the hypotensive agent nitroprusside or hydralazine induced the appearance of Fos-immunoreactivity (Fos-IR) in several prominent groups of central neurons: the piriform cortex, bed nucleus of the stria terminalis, islands of Calleja, subfornical organ, central nucleus of the amygdala, parabrachial nucleus, supraoptic and paraventricular nuclei, pontine A5, locus ceruleus, ventrolateral medulla, the nucleus of the solitary tract, area postrema, and intermediolateral cell column in the spinal cord. Elevation of blood pressure by infusion of phenylephrine caused the appearance of Fos-IR in fewer groups of neurons: the bed nucleus of the stria terminalis, central nucleus of the amygdala, parabrachial nucleus, the nucleus of the solitary tract and area postrema. The differential distribution of Fos neurons in hypotensive versus hypertensive animals underscores the potential application of Fos as a metabolic marker in identifying a network of neurons responding to a specific cardiovascular challenge. Further, simultaneous characterization of the transmitter phenotype of Fos-containing neurons offers an additional advantage of this method over other conventional tract-tracing techniques.

Altered expressions of cardiac Na/K-ATPase isoforms in copper deficient rats

OBJECTIVE

The aim was to determine if copper deficiency affects the expression of Na/K-ATPase alpha isoforms in the rat heart.

METHODS

Copper deficiency was induced by placing weanling rats on a copper deficient diet for 4-5 weeks. Adult ventricular tissue, isolated ventricular myocytes, and brain stems of the control and deficient rats were compared for Cu, Zn-superoxide dismutase (CuZn-SOD) activity and for protein and mRNA contents of Na/K-ATPase alpha isoforms.

RESULTS

In brain stem, where copper deficiency did not alter CuZn-SOD activity, mRNA and protein levels of alpha isoforms also remained unchanged. In ventricular tissue and ventricular myocytes, copper deficiency reduced CuZn-SOD activity, mRNAs of alpha 1 and alpha 2 isoforms, and the alpha 2 isoform protein. The alpha 1 isoform protein of ventricular tissue and its myocytes was marginally reduced by copper deficiency.

CONCLUSIONS

In the rat ventricular tissue, oxidative stress resulting from copper deficiency (1) enhances the turnover of the more oxidant sensitive alpha 2 isoform to a greater extent than the turnover of the alpha 1 isoform; (2) regulates mRNA levels of alpha 1 and alpha 2 isoforms; and (3) contributes to the cardiomyopathy of copper deficiency.

Congenital malformation in newborns. Analysis of 501 cases

Over a 14-year period in Chang Gung Memorial Hospital, 510 out of 44, 362 newborns were found to have birth defects. Maternal age, gestational age, parity, infant sex and birth weight were analyzed for each anomaly and compared to normal newborns. The average maternal age and parity for newborns with congenital anomalies were not significantly different from normal newborns. Mothers giving birth to babies with chromosomal aberrations, however, had a significantly older maternal age than the normal population. The gestational age at delivery was significantly shorter for all except craniofacial anomaly. In addition, there was a high percentage of intrauterine growth retardation in congenital anomalies. The central nervous system, the musculoskeletal system and craniofacial systems were the most commonly involved. The leading anomalies included cleft lip, cleft palate, anencephaly, polydactyly, hydrops fetalis, trisomy 21 and cystic hygroma. With improved ultrasound equipment and other prenatal diagnostic procedures, many defects of the fetus can now be identified. If the fetus is diagnosed with a surgically correctable lesion like cleft lip, it can be kept to term, delivered, then managed postnatally. If life-incompatible malformations have been detected before the 24th week, physicians are in a good position to counsel the parents. After the 24th week termination is proscribed by law. Therefore, physicians must take special care to detect fetal abnormalities early.

Methotrexate treatment of cervical pregnancies with different clinical parameters. A report of three cases

Three cases of cervical pregnancy with different clinical parameters were successfully treated with methotrexate. Case 1 was a viable cervical pregnancy, case 2 was a cervical pregnancy after curettage that developed into a cervical hematoma, and case 3 was a cervical pregnancy at an early gestational age. The interval between diagnosis and treatment ranged from 45 to 76 days. The maximum quantitative beta-human chorionic gonadotropin (beta-hCG) levels in cases 1, 2 and 3 were 100,180, 19,093 and 956 mIU/mL, respectively. These patients showed a progressive decline in beta-hCG levels, and ultrasound showed a gradual decrease in the size of the pregnancies. The interval between treatment and beta-hCG resolution ranged from 14 to 59 days. Only in case 2 did side effects occur, including stomatitis and transient elevation of serum transaminase. In view of the risks of standard therapy and patients' desire for fertility, methotrexate treatment may be a therapeutic alternative for cervical pregnancy.

Maternal serum alpha-fetoprotein levels between 13 and 24 weeks' gestation

Maternal serum alpha-fetoprotein (MSAFP) screening has been widely used and proven valuable in the prediction of a variety of fetal disorders. Any laboratory intending to provide MSAFP screening needs to establish its own reference data. In order to establish a normal MSAFP median value at our own laboratory, 5256 samples of MSAFP were collected from uncomplicated, singleton pregnant women between 13 and 24 weeks' gestation. The MSAFP median levels steadily rise with advancing gestation about 16% per gestational week in average. There were 0.17% and 4.4% of the pregnancies with serum AFP levels less than 0.25 multiple of the median (MoM) and 0.5 MoM respectively, and 4.22% and 1.66% with serum levels above 2.0 MoM and 2.5 MoM. Accurate and satisfactory interpretation of MSAFP screening should be emphasized in the establishment of a well-developed normal median value.

Zinc inhibition of GABA-stimulated Cl- influx in rat brain regions is unaffected by acute or chronic benzodiazepine

Zinc modulation of GABAA receptor function was studied using GABA-stimulated 36Cl- influx into microsacs prepared from rat cerebral cortex, cerebellum and hippocampus. Zinc (10-100 microM) did not affect the basal influx, but significantly inhibited GABA-stimulated 36Cl- influx. The inhibition appeared to be noncompetitive. Zinc produced differing degrees of inhibition of GABA-stimulated 36Cl- influx in different brain regions. The order of sensitivity to zinc inhibition of GABA-stimulated 36Cl- influx was hippocampus > cerebral cortex > cerebellum. These regional differences may reflect the structural heterogeneity of GABAA receptors among brain areas. Zinc inhibition was not affected by the short-term addition of three benzodiazepines, diazepam, bretazenil and triazolam. The effect of diazepam and bretazenil to potentiate GABA-stimulated 36Cl- influx was not affected by zinc, but the effect of triazolam was decreased by zinc. In brain tissue prepared from flurazepam-treated rats, there was no difference compared with controls in zinc inhibition of GABA-stimulated 36Cl- influx. The results indicate that the effects of zinc on the GABAA receptor are largely independent of drugs acting on the benzodiazepine binding site.

c-fos antisense attenuates Fos expression in rat central neurons induced by hemorrhage

Hemorrhage caused by withdrawing 3-4 cm3 of blood from adult rats over a period of 1-2 h induced the expression of Fos proteins, which were detected by immunocytochemical methods in neurons of the hypothalamic supraoptic (SON) and paraventricular (PVN) nuclei, area postrema, nucleus of the solitary tract (NTS), ventrolateral medulla (VLM) and in intermediolateral cell column (IML) of the spinal cord. Daily intraventricular (i.c.v.) injections of c-fos antisense (50 nmol 5 microliters -1) for 2 days prior to hemorrhage markedly attenuated the extent and intensity of Fos-immunoreactivity (FOS-IR) compared with that of rats injected with c-fos sense in the areas mentioned above. The results indicate the effectiveness of i.c.v. administration of c-fos antisense in blocking Fos expression in central neurons following hemorrhage.