[Clinical characteristics and their influences on the survival of leptomeningeal metastasis derived from lung adenocarcinoma harboring epithelial growth factor receptor mutation]

Objective: To analyze the clinical characteristics of leptomeningeal metastasis (LM) patients from epithelial growth factor receptor (EGFR)-mutated lung adenocarcinoma, and their impacts on the survival of the patients. Methods: From July 2018 to July 2022, the clinicopathological data of 81 patients diagnosed as EGFR-mutated lung adenocarcinoma LM by cytopathology who admitted to the Department of Oncology of Xiangya Hospital of Central South University were retrospectively analyzed, including 33 males and 48 females. The age ranged from 31 to 76 years, with a median age of 54 years. All the 81 patients were followed up, with a median follow-up of 21.0 months (95%CI: 12.5 to 29.5 months). The Kaplan Meier method was used to draw survival curve. Cox proportional hazards regression model was used to analyze the impact of the factors on the survival of patients. Results: Among the 81 patients, the interval between the initial diagnosis of lung cancer and the pathological diagnosis of LM in cerebrospinal fluid (CSF) was 0-108 months, with a median interval of 14 months. Fifty-two patients (64.2%) used the third-generation epithelial growth factor receptor tyrosine kinase inhibitor (EGFR-TKIs), while 17 patients (21.0%) used EGFR-TKIs in combination with other drugs, and 12 patients (14.8%) were treated with best supportive care (BSC). Sixty patients (74.1%) had a Kanofsky performance status (KPS) score of less than 60 points, and 71 patients (87.7%) had brain parenchymal metastasis and/or spinal metastasis. Twenty-two patients (27.2%) used pemetrexed through intrathecal CSF, and 17 patients (21.0%) used pemetrexed through the Ommaya sac to the CSF of the ventricle. The incidence of adverse event related to the administration of pemetrexed through CSF was 64.1% (25/39), mainly manifested as myelosuppression, including 22 patients of leukocyte reduction, 25 patients of hemoglobin reduction, and 14 patients of platelet reduction. The median post-leptomeningeal metastasis overall survival (pLM-OS) in 81 patients was 11.0 (95%CI: 7.7-14.3) months. KPS score≥60 points (HR=0.407, 95%CI: 0.170-0.973, P=0.043), CSF cytology negative after treatment (vs persistent positive, HR=0.351, 95%CI: 0.155-0.792, P=0.012), intraventricular administration of pemetrexed (vs non intraventricular administration of pemetrexed, HR=0.319, 95%CI: 0.137-0.745, P=0.008) and the treatment with third-generation EGFR-TKIs after LM (vs EGFR-TKIs in combination with other drugs, HR=0.486, 95%CI: 0.237-0.998, P=0.049) were a factor affecting pLM-OS of patients. Conclusions: Brain parenchyma, or/and spine are the most sites where the LM patients concurrently metastasize. KPS score≥60 points and CSF cytology negative after treatment, intraventricular administration of pemetrexed and the treatment with third-generation EGFR-TKIs are indictors affecting pLM-OS of the patients.

Acute respiratory distress syndrome following multiple wasp stings treated with extracorporeal membrane oxygenation: A case report

BACKGROUND

It is necessary for clinicians to be aware of a rare but possible acute respiratory distress syndrome (ARDS) complication caused by multiple wasp stings. Severe ARDS has a high mortality rate but no specific pharmacotherapies have been identified to date. This case study presents the first case of severe ARDS caused by multiple wasp stings, treated successfully with extracorporeal membrane oxygenation (ECMO). It also emphasizes the effectiveness of early ECMO treatment for severe ARDS with persistent hypoxemia.

CASE SUMMARY

A 24-year-old woman was admitted to the emergency department after being stung by more than 10 wasps within a 30-min period, with clinical symptoms of multiple rashes, dizziness, chest tightness, nausea, and vomiting. On the 2^nd day of admission, the patient developed progressive dyspnea. The patient was diagnosed with ARDS based on clinical manifestations and lung computed tomography (CT) scan. Because of the progressive dyspnea, the intensive care unit physician performed endotracheal intubation and continued to provide ventilator support, but the patient’s respiratory distress worsened, as indicated by the ratio of arterial partial pressure of oxygen to fraction of inspired oxygen. Veno-venous ECMO was initiated for 6 d. On day 7 of admission, ECMO was stopped. On the 11^th day of admission, CT scan of the lungs revealed significant reduction of ground-glass opacities and consolidations. After about 2 wk, the patient recovered completely from ARDS and was discharged to home. At the 2-mo follow-up, the patient was in good health with no recurrence of dyspnea nor chest tightness.

CONCLUSION

ARDS complication caused by multiple wasp stings may be fatal when mechanical ventilation becomes dangerous due to persistent hypoxemia and despite optimization of ARDS management. We propose that the early implementation of ECMO is a relatively effective treatment, although the evidence is relatively limited.

[The clinical characteristics and treatment of children with disorders of sex development and early prevention of their siblings]

Disorders of sex development (DSD) is a class of diseases characterized by discordant phenotypes of sex chromosome karyotypes, gonads and external genitalia. The etiology is complex and the clinical manifestations are varied. Understanding the clinical characteristics of patients with various types of DSD help make accurate etiological diagnosis and prepare individualized treatment plans according to the etiology (including sex assignment, endocrine hormone replacement, surgery and fertility protection, etc.). Due to the increased risk of DSD in the second pregnancy of the parents of DSD patients, early preventive measures such as pre-pregnancy genetic counseling and prenatal diagnosis during pregnancy can effectively avoid or reduce the risk of DSD in their siblings.

Case Report: A Candida Meningitis in an Immunocompetent Patient Detected Through the Next-Generation Sequencing

Background: Fungal infections of the central nervous system (CNS) are not commonly seen clinically. Clinical diagnosis of fungal infections often depend on the pathogen culture and the clinical features. This method is time-consuming and insensitive, which can lead to misdiagnosis. The authors introduce an adult patient with fungal infections diagnosed by next-generation sequencing (NGS).

Case: The patient was a 60-year-old male Chinese who had both hypermyotonia of the lower extremities and fever. The auxiliary examinations such as MRI, CT, and cerebrospinal fluid (CSF) analysis showed obvious abnormalities. Because of the difficulties in diagnosis, it was hard to determine the treatment plan. The NGS detected specific sequences of Candida albicans in 3 days. The patient was then treated with liposomal amphotericin B and fluconazole. About 3 weeks later, the symptoms of the patient improved significantly and he was discharged from the hospital.

Conclusion: Compared with the routine cultural method, NGS has made a huge advancement in infection diagnosis and targeting antimicrobial therapy for CNS infection.

[Viral pathogenic spectrum analysis of severe acute respiratory infection cases in Luohe City, Henan province from 2017 to 2019]

Objective: The purpose of this study was to investigate the characteristics of viral pathogen spectrum and the epidemiological characteristics of each viral pathogen in hospitalized cases associated with severe acute respiratory infection (SARI) in Luohe City, Henan Province from 2017 to 2019. Methods: Based the SARI Case Surveillance Platform, SARI cases were collected in Central Hospital of Luohe City, Henan Province from November 2017 to February 2019. In the end, 783 SARI cases were included, whose throat swabs were taken within 24 h of admission, as well as their demographic characteristics, onset time, clinical characteristics and other information recorded. At the same time, viral identification was performed, and the age and time distribution of each virus were analyzed. Results: The age of 783 SARI cases shown as M (P₂₅, P₇₅) was 3 (1, 5) years old, ranging from 1 month to 95 years old. Children under 5 years old were the majority (71.01%). The males (61.81%) were more than females (38.18%). Among the 783 SARI cases, a total of 9 kind of viruses were identified with 64.88% (508/783) of the throat swabs tested positive for at least one virus. The positive rate of influenza virus and human respiratory syncytial virus were both 20.18% (158 cases), which was the highest among all the detected respiratory virus. The co-infection rate was 15.84% (124/783), among which double infection was the most common, accounting for 85.48% (106/124) of the co-infected cases. And human respiratory syncytial virus, human rhinovirus and influenza virus were the most common pathogen in co-infection cases. Moreover, the viral positive rate was 68.71% in children aged 5 years and 63.27% in people aged 60-95 years. Influenza and human respiratory syncytial virus dominated in winter and spring, while human parainfluenza virus was the main infection in summer. Conclusion: Influenza virus and human respiratory syncytial virus were the main viruses in throat swabs of SARI cases from 2017 to 2019 in Luohe City, Henan Province. There were differences in the age and seasonal epidemiological characteristics of each virus.

[Analysis on the performance evaluation of the Global Fund Malaria Programme in China from 2003 to 2013]

Objective: To analyze the performance of the 5 Global Fund Malaria Programmes in China from 2003 to 2013. Methods: All of the proposals, summaries, progress reports, survey reports, Monitoring& Evaluation reports, and performance rating reports of the 5 Global Fund Malaria Programmes in China and the epidemic data of program areas were collected for statistical analysis from 2012 to 2014. Symposiums were held with relevant experts from national and provincial Centers for Disease Control and Prevention, program managers and staffs from national and provincial Global Fund Malaria Programme offices. The completion of the relevant programme indicators (including the general grant information such as program areas, beneficiaries and funding; the implementation of malaria control measures; the performance of malaria control measures; the malaria incidence in the program areas; the prevalence of malaria parasites; and program management and performance evaluation) were analyzed, and the results: of the symposiums were summarized. Results The implementation period of the 5 Global Fund Malaria Programs were as follows: Round 1 from 2003 to 2008, Round 5 from 2006 to 2010, Round 6 from 2007 to 2012, Round 10 from 2012 to 2013, and National Strategy Application (NSA) from 2010 to 2012. Under the support of all the Global Fund Malaria Programs, a total of 11 936 726 fever cases received microscopic tests, 1 485 915 confirmed and suspected malaria cases were treated, 1 579 773 Long Lasting Insecticide-treated Nets were distributed, 3 414 633 regular nets were treated by insecticide, 40 298 284 primary and middle school students received health education on malaria control. Compared with the baseline value, the completion rates of each indicator increased after the implementation of the programs. The growth value ranged from 12.83% to 83.11%, among which the biggest growth was the value of the indicator'Percentage of households with at least one LLIN/ITN in target areas', and it increased from 9.2% (baseline value of 2006) to 92.31% (value of 2012). The malaria incidence in program areas has dropped significantly year by year, the annual reported malaria incidence in Yunnan and Hainan provinces decreased from 1 950/100 000, 3 850/100 000 in 2002 to 3.31/100 000, 0.15/100 000 in 2012, the P. falciparum malaria incidence in target counties in Hainan province decreased from 90.6/100 000 in 2002 to 0/100 000 in 2012. As from the implementation of NSA grant in 2010 to 2012, the annual reported malaria incidence in 92% of the 75 Type 1 counties was less than 1 per 10 000, 60.00% of Type 1 counties and 98.69% of the 687 Type 2 counties reported zero locally transmitted malaria cases. The Global Fund Secretariat had conducted a total of 37 performance evaluations, of which 9 have been rated as A1, 4 rated as A2, 19 rated as B1 and 5 rated as B1. Conclusions: The Global Fund Malaria Program in China has been closely integrated with the goal and task of National Malaria Control Program, reducing malaria burden in target areas, and pushing Chinese malaria control efforts to move from control to elimination.

[Previous medical or surgical abortions and subsequent risk of preterm birth: a birth cohort study]

Objective: To understand the association between medical abortion (MA) or surgical abortion (SA) and the risk of preterm birth (PTB) in subsequent pregnancy. Methods: The prospective cohort study was conducted in Ma'anshan, Anhui province. The information about demographic characteristics and previous MA or SA of 3 474 pregnant women were collected before 14 gestational weeks. Logistic regression analysis was conducted to compare the rates of preterm birth based on the history of previous MA or SA, and 3 256 live births were included in the analysis. Results: The PTB rate and spontaneous preterm birth (sPTB) rate were 4.12% (n=134) and 2.49% (n=81) respectively. Previous MA was associated with an increased risk of total PTB (RR=2.00, 95%CI: 1.04-3.85 for one MA and RR=3.58, 95%CI: 1.04-12.30 for two or more MAs) and sPTB (RR=2.51, 95% CI: 1.23-5.15). The risk of PTB in women with one SA (RR=0.67, 95%CI: 0.42-1.01) or more SA (RR=0.97, 95%CI: 0.51-1.85) did not differ significantly compared with the women with no history of SA. Conclusion: This study suggests that medical abortion could increase the risk of PTB or sPTB.

Effects of NELL2 on the regulation of GnRH expression and puberty in female rats

Neural tissue-specific epidermal growth factor-like repeat domain-containing protein (NELL2) was previously found to play an important role in nerve growth, neural differentiation, neural elasticity, synaptic transport, and vesicle release. In this study, we examined the effect of NELL2 on gonadotropin-releasing hormone (GnRH) neurons and the initiation of puberty in female rats. We studied changes in NELL2 mRNA and protein expression at different stages of sexual development (postnatal days 30, 35, and 45) in female rats to determine the impact of NELL2 on GnRH mRNA expression. We also investigated the influence on the vulva-opening age by inhibiting NELL2 mRNA expression through lentiviral vector-mediated RNA interference. The intraventricular administration of an NELL2-interfering virus reduced NELL2 and GnRH expression at multiple stages of sexual development and delayed the age of vulva-opening in female rats. These results demonstrate that lentiviral-mediated RNA interference technology can be used for targeted regulation of sexual development in vivo. In addition, we found that NELL2 regulated the initiation of puberty in female rats.

Ferulic acid induces heme oxygenase-1 via activation of ERK and Nrf2

This study investigated the effect of ferulic acid (FA) on the up-regulation of heme oxygenase-1 (HO-1) in lymphocytes and the molecular mechanisms involved. Lymphocytes were treated with FA (0.001-0.1 μM) for certain times. Cell viability, the activity and level of expression of HO-1, and signal pathways were analyzed. FA significantly upregulated HO-1 expression both at the level of mRNA and protein in lymphocytes. Moreover, FA induced NF-E2-related factor (Nrf2) nuclear translocation and transcriptional activity, which is upstream of FA induced HO-1 expression. In addition, lymphocytes treated with FA exhibited activation of extracellular regulated kinase (ERK) and treatments with U0126 (an ERK kinase inhibitor) attenuated the FA induced activation of Nrf2, resulting in a decrease in HO-1 expression. Zinc protoporphyrin (ZnPP, a HO-1 inhibitor) markedly suppressed cytoprotection from radiation-induced cell damage by FA. Results suggested that the ERK signaling pathway controlled the anti-oxidation of FA by regulating the expression of the antioxidant enzyme HO-1.

Differential detection of B virus and rhesus cytomegalovirus in rhesus macaques

Non-human primate herpesviruses establish and maintain a lifelong persistent infection in immunocompetent hosts in the absence of clinical signs of disease. A fundamental issue for understanding the natural history of non-human primate herpesviruses is whether the viruses are maintained in a truly latent state or one characterized by a low level of chronic expression. To address this issue, a real-time PCR assay was developed to quantify Cercopithecine herpesvirus type 1 (B virus) DNA in mucosal fluids of rhesus macaques. This assay was rapid, sensitive (10 genome copies) and specific for B virus obtained from multiple species of macaques. The shedding profile of B virus was compared to another endemic herpesvirus, rhesus cytomegalovirus (RhCMV), in colony-reared monkeys. Mucosal swabs or saliva samples were taken daily from two groups of seropositive monkeys undergoing either a stressful relocation (group 1) or daily chair restraint (group 2). B virus DNA was detected in mucosal fluids from four animals relocated during the breeding season (group 1) but not from 10 animals moved at other times of the year. No B virus DNA was detected in any group 2 monkey. In contrast, RhCMV DNA was detected in the majority of animals of both groups 1 and 2. Detection of B virus DNA shedding is a relatively rare event associated with the breeding season, while RhCMV DNA is persistently detected in mucosal fluids of most monkeys.

[Inhibitory effect of genistein on the proliferation of the anterior pituitary cells of rats]

The effects of tyrosine kinase inhibitor genistein on the proliferation of rat anterior pituitary cells and mouse AtT-20 cells were studied using techniques of cell culture, 3H-TdR incorporation, flow cytometric analysis and electron microscope. Genistein significantly inhibited the proliferation of rat anterior pituitary cells and mouse AtT-20 cells. Genistein (50 and 100 mumol/L) blocked the proliferation of AtT-20 cells at G0/G1 and G2/M phases and evoked an apoptotic peak of these cells with an apoptotic ratio of 19.9% and 36.4%. The apoptotic cells were also observed under the electron microscope. In consequence, genistein, as a tyrosine kinase inhibitor, can significantly inhibit the proliferation of pituitary cells possibly by inducing apoptosis, and the tyrosine kinase activity may play a key role in the proliferation and differentiation of pituitary cells.

Primate cytomegaloviruses encode and express an IL-10-like protein

An open reading frame (ORF) with homology to interleukin-10 (IL-10) has been identified in rhesus cytomegalovirus (RhCMV). The IL-10-like protein is generated from a multispliced, polyadenylated early gene transcript encompassing part of the corresponding UL111A ORF of human CMV (HCMV). Immunological analyses confirm expression of the IL-10-like protein both in tissue culture and in RhCMV-infected rhesus macaques. Conserved ORFs were subsequently identified in human, baboon, and African green monkey CMV, and a fully processed transcript has been mapped in fibroblasts infected with the Towne strain of HCMV. The conservation of this previously unrecognized ORF suggests that the protein may play an essential role in primate CMV persistence and pathogenesis.

Prenatal exposure to toluene results in abnormal neurogenesis and migration in rat somatosensory cortex

Toluene inhalant abuse during pregnancy may result in growth-retarded microcephalic newborns who subsequently demonstrate developmental impairment. By using a rat model of toluene-abuse embryopathy, we studied the effects of prenatal toluene exposure on the generation and migration of cortical neurons. Dams were exposed by gavage to either corn oil or toluene diluted in corn oil on d 6-21 of gestation. The time of origin of cortical neurons was determined in the mature pups of dams injected with the thymidine analogue 5'-bromodeoxyuridine on 1 d during the period from d 13-21 of gestation. 5'-Bromodeoxyuridine-labeled neurons were identified by immunohistochemistry in a 400-microm-wide column of somatosensory cortex. The brains of the toluene-exposed pups had a significant reduction in the number of neurons within each cortical layer (p < 0.001). Depending on the cortical layer, the generation of neurons in the toluene-exposed pups was delayed by 1 or 2 d. In addition, the brains of the toluene-exposed pups also showed evidence of abnormal neuronal migration. However, there were no differences in either brain weight or body weight between the control and toluene-exposed pups. These observations suggest that although prenatal toluene exposure results in abnormal neuronal proliferation and migration, brain weight in the toluene-exposed pups may be preserved by enhanced development of glia or the neuropil.

Pathogenesis of experimental rhesus cytomegalovirus infection

Human cytomegalovirus (HCMV) establishes and maintains a lifelong persistence following infection in an immunocompetent host. The determinants of a stable virus-host relationship are poorly defined. A nonhuman primate model for HCMV was used to investigate virological and host parameters of infection in a healthy host. Juvenile rhesus macaques (Macaca mulatta) were inoculated with rhesus cytomegalovirus (RhCMV), either orally or intravenously (i.v. ), and longitudinally necropsied. None of the animals displayed clinical signs of disease, although hematologic abnormalities were observed intermittently in i.v. inoculated animals. RhCMV DNA was detected transiently in the plasma of all animals at 1 to 2 weeks postinfection (wpi) and in multiple tissues beginning at 2 to 4 wpi. Splenic tissue was the only organ positive for RhCMV DNA in all animals. The location of splenic cells expressing RhCMV immediate-early protein 1 (IE1) in i.v. inoculated animals changed following inoculation. At 4 to 5 wpi, most IE1-positive cells were perifollicular, and at 25 wpi, the majority were located within the red pulp. All animals developed anti-RhCMV immunoglobulin M (IgM) antibodies within 1 to 2 wpi and IgG antibodies within 2 to 4 wpi against a limited number of viral proteins. Host reactivity to RhCMV proteins increased in titer (total and neutralizing) and avidity with time. These results demonstrate that while antiviral immune responses were able to protect from disease, they were insufficient to eliminate reservoirs of persistent viral gene expression.

[Effects of monocarboxylic acid derivatives on cardiac ventricular CFTR Cl- channels in guinea pig]

Using the whole-cell recording technique, the effects of monocarboxylic acid derivatives on cystic fibrosis transmembrane conductance regulator (CFTR) Cl(-)-channel were examined in guinea pig ventricular myocytes. Anthracene-9-carboxylic acid (9-AC) added to the bath solution further enhanced the outward component of isoproterenol-induced currents in a reversible manner, whereas 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB) or diphenylamine-2-carboxylic acid (DPC) induced a biphasic effect on the currents. Either NPPB or DPC first produced a transient increase in the outward component of current before ensuing inhibition. Intracellular NPPB was found to potentiate isoproterenol-activated currents. It is concluded that these monocarboxylic acid derivatives have different binding sites in cardiac ventricular myocytes, which might partially account for the varied effects in blocking anion channels.

Regulation of ROMK1 channel by protein kinase A via a phosphatidylinositol 4,5-bisphosphate-dependent mechanism

ROMK inward-rectifier K+ channels control renal K+ secretion. The activity of ROMK is regulated by protein kinase A (PKA), but the molecular mechanism for regulation is unknown. Having found that direct interaction with membrane phosphatidylinositol 4, 5-bisphosphate (PIP2) is essential for channel activation, we investigate here the role of PIP2 in regulation of ROMK1 by PKA. By using adenosine-5'-[gamma-thio]triphosphate) (ATP[gammaS]) as the substrate, we found that PKA does not directly activate ROMK1 channels in membranes that are devoid of PIP2. Rather, phosphorylation by PKA + ATP[gammaS] lowers the concentration of PIP2 necessary for activation of the channels. In solution-binding assays, anti-PIP2 antibodies bind PIP2 and prevent PIP2-channel interaction. In inside-out membrane patches, antibodies inhibit the activity of the channels. PKA treatment then decreases the sensitivity of ROMK1 for inhibition by the antibodies, indicating an enhanced interaction between PIP2 and the phosphorylated channels. Conversely, mutation of the PKA phosphorylation sites in ROMK1 decreases PIP2 interaction with the channels. Thus, PKA activates ROMK1 channels by enhancing PIP2-channel interaction.

Tyrosine kinase-independent extracellular action of genistein on the CFTR Cl- channel in guinea pig ventricular myocytes and CFTR-transfected mouse fibroblasts

The effects of genistein, a protein tyrosine kinase inhibitor, on the cystic fibrosis transmembrane conductance regulator (CFTR) Cl- channel were studied in guinea pig ventricular myocytes and in NIH3T3 mouse fibroblasts stably transfected with CFTR cDNA by the whole-cell patch-clamp technique. Genistein did not activate whole-cell Cl- currents when applied to the intracellular (pipette) solution. In contrast, when applied to the extracellular solution, genistein alone promptly activated the Cl- current in a fully reversible manner. Also, extracellular genistein reversibly potentiated the forskolin-activated Cl- current. However, both basal and forskolin-activated Cl- currents were not affected by other protein tyrosine kinase inhibitors, including herbimycin A, lavendustin A, tyrphostin 21, tyrphostin 47, and tyrphostin 51. A nonspecific inhibitor of protein phosphatases, orthovanadate, had no effect on the genistein-induced activation of CFTR. Pretreatment with a protein kinase inhibitor, either H-89 or H-7, or with an adenylate cyclase inhibitor, SQ 22536, also had no effect on the genistein-induced response. Thus, it is concluded that genistein alone activates CFTR by a protein tyrosine kinase-independent and protein phosphatase-independent mechanism from the extracellular side, but not from the intracellular side.

Toluene abuse embryopathy: longitudinal neurodevelopmental effects of prenatal exposure to toluene in rats

To determine the longitudinal effects of prenatal exposure to toluene in rats, dams received daily gavage doses of toluene diluted in corn oil on Days 6 through 19 of gestation, whereas control dams received corn oil. Litters were evaluated either on Gestational Day 19, Postnatal Day 10, or Postnatal Day 21; morphometric analysis of brain and measurements of brain DNA, cholesterol, and protein were made. Prenatal toluene exposure produced growth retarded fetuses with smaller brain and caudate-putamen volumes, fewer forebrain cell nuclei (DNA), and a reduction in both hindbrain cell size (protein/DNA) and myelination per cell (cholesterol/DNA). Postnatal catch-up growth occurred in the prenatally toluene-exposed pups, and by Postnatal Day 21 these differences had resolved. However, on Postnatal Day 21, a significant reduction in forebrain myelination/cell was present in the prenatally toluene-exposed pups. Therefore, whereas the effects of toluene administered prior to the time of the brain growth spurt were, for the most part, reversible, these exposures resulted in reduced forebrain myelination that may be permanent.

Phosphatase-mediated enhancement of cardiac cAMP-activated Cl-conductance by a Cl- channel blocker, anthracene-9-carboxylate

An aromatic carboxylate, anthracene-9-carboxylic acid (9-AC), is known as a Cl- channel blocker. However, variable 9-AC effects have hitherto been reported on the cardiac cAMP-activated Cl- conductance, when applied extracellularly. We have reexamined the 9-AC effect on the Cl-conductance activated by isoproterenol or forskolin in guinea pig ventricular myocytes under whole-cell patch-clamp conditions. The inward current was blocked by 9-AC at > or = 0.5 mmol/L, but in contrast, the outward current was enhanced at much lower concentrations (ED50, approximately 13 mumol/L). 9-AC applied by the intracellular perfusion technique increased both the inward and outward currents. In the presence of intracellular 9-AC, deactivation of the conductance after washout of isoproterenol or forskolin was largely prevented. 9-AC produced an enhancing effect, even after inhibiting the deactivation process by okadaic acid (OA), whereas it failed to produce additional-effects in the presence of orthovanadate. Intracellular application of 9-AC together with OA virtually abolished the current deactivation. The 9-AC effects on the Cl-conductance were not dependent on intracellular Ca2+ or pH. Putative inhibitors of alkaline (bromotetramisole) and acid phosphatases (tartrate) were without effect. 9-AC failed to inhibit the activities of purified protein phosphatase (PP)-1, -2A, and -2C. In the extract of guinea pig ventricle, 9-AC (> or = 10 mumol/L for full action) significantly inhibited a fraction of endogenous phosphatase activity that was sensitive to orthovanadate but not to OA, bromotetramisole, and tartrate. It is concluded that 9-AC blocks cardiac cAMP-activated (cystic fibrosis transmembrane conductance regulator) Cl- conductance from the extracellular side but enhances the conductance from the intracellular side by inhibiting an orthovanadate-sensitive phosphatase distinct from PP-1, -2A, -2B, or -2C and alkaline or acid phosphatase.

The evaluation of developmental toxicity of chemicals exposed occupationally using whole embryo culture

The purpose of this study was to employ the whole embryo culture (WEC) system to evaluate the developmental toxicity of industrial chemicals. Five chemicals including lead, cadmium, vinyl chloride, 1,2-dichloroethan, and carbon disulphide were tested in our laboratory both in vitro and in vivo (except lead). In vitro studies showed that cadmium and lead were teratogenic in the rat; whilst carbon disulphide, 1,2-dichloroethan and vinyl chloride mainly induced embryo growth retardation. The in vitro effects on development of the five industrial chemicals were similar to the effects in vivo. The in vitro effects were studied by three different exposure routes, direct exposure--chemicals added to the culture medium; indirect exposure--serum prepared from treated rats then used as culture medium, and pre-exposure--embryos treated maternally then explanted into control (untreated) culture medium. Comparing these three different exposure routes suggests that the last exposure route is the most effective when using WEC to evaluate developmental toxicity of industrial chemicals. The effects on embryo development of culturing in sera prepared from subjects occupationally exposed to antineoplastic drugs (ADs) was also tested by the WEC system. Embryos were cultured with human serum that was thought to contain ADs or ADs' metabolic materials (serum taken from nurses routinely handling ADs), to evaluate the effects of ADs on embryo development. Embryos (9.5-day) cultured with serum from 11 female nurses who had been handling ADs for 2-17 years in the oncology department all survived, but showed slight growth retardation. Embryos cultured with serum from 30 healthy and unexposed people served as controls and embryo development in their serum was normal.

Development of a rat model of toluene-abuse embryopathy

A rat model was developed to study toluene-abuse embryopathy, a clinical syndrome which occurs in offspring of women who abuse toluene during pregnancy. On d 6-19 of gestation, eight dams received a daily gavage dose of toluene, 650 mg/kg body weight, diluted in corn oil, whereas eight control dams and eight pair-fed dams received corn oil. The fetuses were delivered on d 19 of gestation. In the toluene-exposed group, the weights of the fetuses were reduced by 21.6% (p < 0.001), and a delay in skeletal ossification was demonstrated. Toluene exposure significantly reduced the weight of the fetal brain by 11.9% (p < 0.001), as well as the weights of the heart, liver, and kidney. Organ weight/body weight ratios did not differ significantly. Morphometric analysis of brain sections demonstrated that toluene exposure resulted in smaller brains together with an increase in the size of the ventricular system and a reduction in the size of the caudate nucleus. Although toluene exposure resulted in a 13.7% reduction in maternal food consumption, the observations made in the pair-fed group did not differ from those made in the control group. These findings suggest that prenatal exposure to toluene results in generalized fetal growth retardation, and that these effects are not due to the reduction in maternal food consumption.

Effects of environmental tobacco smoke exposure in utero and/or postnatally on brain development

We evaluated whether environmental tobacco smoke exposure in utero and/or postnatally affects the biochemical composition of the brain. Pregnant Sprague-Dawley rats were exposed to filtered air (FA) or to sidestream smoke (SS) for 4 h/d, 7 d/wk from d 3 of pregnancy until delivery, then their female pups were exposed to either FA or SS for 9 wk postnatally. This resulted in four exposure conditions: in utero FA followed by postnatal FA (FA/FA), in utero FA followed by postnatal SS (FA/SS), in utero SS followed by postnatal FA (SS/FA), and in utero SS followed by postnatal SS (SS/SS). After completion of the exposures, the brains were removed and divided at the pontomesencephalic junction into forebrain and hindbrain; each specimen was then analyzed for DNA, protein, and cholesterol concentration. Data were analyzed by 2-way analysis of variance. In utero SS had no effect on these three biochemical measurements. However, postnatal SS reduced hindbrain DNA concentration (an indicator of cellular density) by 4.4% (p = 0.001). In addition, the hindbrain protein/DNA ratio (an index of cell size) was increased in these animals by 8.4% (p = 0.001). Hindbrain weight was not affected by SS exposure, but body weight was reduced by 6.4% (p = 0.016). These data suggest that postnatal exposure to SS affects the hindbrain (a region which undergoes significant postnatal growth) by reducing the total number of cells and by increasing cell size. Hindbrain cellular hypertrophy may help offset the decrease in cell number, thereby leaving hindbrain weight unchanged. Despite preserved hindbrain weight, these effects of postnatal exposure to SS may result in neurologic dysfunction.

The effects of high-dose toluene on embryonic development in the rat

Developmental disability, intrauterine growth retardation, renal anomalies, and dysmorphic features have been described in offspring of women who abuse toluene during pregnancy. A Sprague-Dawley rat model was developed to study this clinical syndrome. During d 6-19 of gestation, 11 treated dams received daily gavage doses of toluene, 520 mg/kg body weight, diluted in corn oil, and 11 control dams received corn oil. This dose of toluene simulates the blood toluene levels obtained after an inhalation exposure to 3290 ppm toluene, an inhalation level in the lower end of the range experienced by toluene abusers. Maternal weight gain was 24% less in the toluene-exposed group (p < 0.002); however, there were no maternal deaths. The fetuses were delivered on d 19 of gestation, and 287 fetuses (148 toluene exposed, 139 control) were examined. Toluene treatment did not affect the number of implantations or stillbirths. There were no toluene-induced major congenital malformations or neuropathologic changes noted. In the toluene-treated group, the weights of the fetuses were reduced by 9.4% (p < 0.004) and placental weights were reduced by 10.3% (p < 0.01). Toluene exposure also reduced fetal organ weights as follows: brain 4.6%, heart 5.9%, liver 13.2% (p < 0.02), and kidney 13% (p < 0.05). Organ weight/body weight ratios did not differ significantly, suggesting that prenatal toluene exposure produced a generalized growth retardation.

Crossed reticular formation connections that mediate the startle reflex in rats

The startle response is a bilateral response even when elicited by unilateral acoustic or tactile stimuli. Similarly, unilateral electrical stimulation of the reticular formation also elicits a bilateral startle-like response. To examine whether crossed reticular formation connections can distribute the effects of unilateral stimulation across the midline, we delivered one pulse to the caudal pontine (RPC) or medullary reticular formation (MRF) and a second pulse to the opposite side of the brain, at various interpulse intervals. The symmetric collision effects suggest that axons which produce at least 37% (range 23-53%) of the startle response efficacy cross from RPC to RPC with a mean conduction velocity of 13 m/s. Similar collision effects were observed between RPC and MRF sites but at shorter conduction times. To examine which axons might cause these collision effect, the axonally transported label DiI was injected post mortem into 37 RPC sites. Many coarse axons were observed to cross in fascicles between bilateral RPC sites and then separate in the contralateral RPC. The fiber diameters and trajectories of these DiI-labelled axons are consistent with the conduction velocities and trajectories of the substrates mediating the startle-like response determined in collision tests.

Perineuronal satellitosis in the human hippocampal formation

A previously unreported example of perineuronal satellitosis in the medial CA1 and adjacent subiculum in the human hippocampal formation is described. This phenomenon is characterized by a clustering of glial cells in relation to the perikarya of a subpopulation of neurons in the deep pyramidal layer and around most neurons scattered in the stratum oriens and subcortical white matter. Most of the perineuronal satellite glia were identified as oligodendrocytes based on their nuclear chromatin patterns and antigenic properties. Satellite oligodendrocytes were mostly of the medium dense variety. A type of satellite glia with nuclear features of the dark oligodendrocyte could not be identified unequivocally using the antigenic criteria employed in this study.

[Effects of furyl-dihydropyridine on action potential ventricular myocardium of rabbit in vivo and isolated guinea pig left atrium in vitro]

Effects of furyl-dihydropyridine (FDP) on action potential of rabbit ventricular myocardium in vivo were observed with floating microelectrode technique. FDP 0.5 mg.kg-1 i.v. increased APD30 from 104 +/- 7 to 127 +/- 7 ms, APD90 from 146 +/- 10 to 177 +/- 9 ms (P < 0.01, n = 7), decreased the heart rate from 230 +/- 18 to 203 +/- 20 bpm (P < 0.05). Nifedipine (Nif) 0.5 mg.kg-1 i.v. reduced APD and increased the HR in rabbit. In guinea pig left atrium, FDP and Nif decreased the APD, the effects of acetylcholine to shorten the APD was antagonized by FDP 1 mumol.L-1. In rabbit's sinoatrial nodes, FDP 0.5, 1 mumol.L-1 also suppressed the APA and increased the spontaneous sinus cycle length (SCL) and APD50. These results indicate that FDP may inhibit the Ca2+ and K+ currents of myocardium.

Motor neurons of the laryngeal nerves

The present study was undertaken to determine the relationship between the motor neurons of the superior and recurrent laryngeal nerves within the nucleus ambiguus. The retrograde transport of horseradish peroxidase was utilized to identify the motor neurons subsequent to its application to the proximal transected end of the superior and recurrent laryngeal nerves. Labeled superior laryngeal motor neurons were distributed ventrolaterally in the rostral portion the nucleus. The recurrent laryngeal motor neurons were distributed throughout the nucleus with two distinct populations: a rostral group and a caudal group. The rostral group overlaps the motor neurons of the superior laryngeal nerve. The caudal group occupies that portion of the nucleus that is classically described for the recurrent laryngeal nerve. Additional superior laryngeal nerve labeled perikarya were found in the dorsal motor nucleus of the vagus. This study defines the rostral distribution of the recurrent laryngeal nerve motor neurons and suggests that this rostral group is a component of the neuroanatomical substrate that is involved in the co-activation of the laryngeal abductors controlling the laryngeal aperture.

Afferent projections of the superior and recurrent laryngeal nerves

The central afferent projections of the superior and recurrent laryngeal nerves were investigated in the rat, utilizing the transganglionic transport of WGA-HRP. Labelled superior laryngeal nerve terminal fields were found bilaterally in the interstitial and medial subnuclei of the nucleus tractus solitarii with the ipsilateral being more dense. The distribution of the recurrent laryngeal nerve terminals were similar to that of the SLN with two major differences: the projections were ipsilateral, and there was a marked decrease in the terminal field density. The terminal field density differences were confirmed by quantitatively identifying the labelled ganglion cells of the vagus nerve. These findings accurately delineate the first integrative components in the mediation of the complex laryngeal reflexes.

[Bone metabolic disorders due to antiepileptic drugs and the therapeutic effect of vitamin D2]

Bone mineral content(BMC), serum calcium, phosphorus and AKP were measured in 64 epileptic patients on long-term treatment with antiepileptics and in 14 epileptic patients not taking antiepileptics. All these indices were also measured in a group of healthy controls. In the epileptic patients taking antiepileptics BMC was significantly lower than that in the control group. Serum calcium and phosphorus were also lower than normal, while AKP was elevated. In the epileptic patients not taking antiepileptics BMC was not significantly different from that in the control group. Serum calcium, phosphorus and AKP were all normal. After 3 months of treatment with vitamin D2, BMC and serum calcium level returned to normal, but AKP was still significantly lowered.

[Preventive effects of fortified pollen on diphenylhydantoin teratogenesis]

This paper reports the preventive effects of fortified pollen and folic acid on diphenylhydantoin (DPH) teratogenesis in pregnant SD rats. The experiment showed that i.p. injection of DPH 75mg/kg per day to pregnant rats on gestational days 7 through 11, and feeding of fortified pollen (pollen 10g/kg per day plus folic acid 20mg/kg per day) or folic acid (20mg/kg per day) on gestational days 0 through 20 may partly prevent the embryotoxicity and fetal toxicity produced by DPH. However, the preventive effects of fortified pollen is better than those of folic acid on the following: decrease of fetal body weight; retarded ossification of metacarpus, proximal phalanx, metatarsus, and supraoccipital bone; sternebrae ossification agenesis; subcutaneous hemorrhage; single eye defect; hydronephrosis and the widening of subarachnoid space. This paper also discusses the possible mechanism of prevention of fortified pollen and folic acid against DPH teratogenesis.

Reduction of the teratogenic effects of phenytoin by folic acid and a mixture of folic acid, vitamins, and amino acids: a preliminary trial

Four groups of pregnant rats were used to study the effects of dietary supplements of folic acid (FA) alone or a mixture of FA, vitamins (Vit), and amino acids (AA) on the teratogenic effects of phenytoin (PHT). Groups A, B, and C received intraperitoneal (i.p.) injections of high-dose (75 mg/kg/day) phenytoin (PHT) between 9 and 11 days of gestation, while the controls, group D, rats received distilled water. The diet was modified in groups A and B. Group A received a mixture of FA, Vit, and AA, while group B received FA supplementation alone. Groups C and D received a regular diet. We found that PHT, when administered without dietary supplementation, resulted in a decrease in weight and length of the fetuses, an increased rate of subcutaneous (s.c.) bleeding, a retardation of ossification centers, and an increased number of malformations. Supplementation of the diet with FA alone or FA with Vit and AA resulted in statistically greater fetal weight and length, decreased subcutaneous bleeding, more ossification centers, and fewer malformations. The mixture of FA and Vit and AA was superior to FA alone in reducing the incidence of internal abnormalities, ossification abnormalities of the distant phalanxes, and s.c. bleeding.

Epidemiology of epilepsy in urban areas of the People's Republic of China

To determine the prevalence of major neurologic disorders, a door-to-door survey was conducted in six cities of the People's Republic of China during 1983 in a well-defined population of 63,195. The survey included a complete census and a screening interview together with an examination having high sensitivity for detecting individuals with frequently occurring neurologic disorders, including epilepsy. All individuals with responses or findings suggesting neurologic disease were examined by senior neurologists using standardized diagnostic criteria. There was 100% cooperation among the study subjects. Two hundred eighty-nine individuals alive on prevalence day (January 1, 1983) were identified as having epilepsy, yielding a lifetime age-adjusted (to the 1960 U.S. population) point prevalence ratio of 4.4/1,000. There were 16 people who developed epilepsy in the sample population during 1982, providing an age-adjusted incidence rate of 35/100,000 per year. The most frequent type identified was generalized convulsive seizures. Brain injury, intracranial infection, and cerebrovascular disease, in that order, were the leading putative causes of epilepsy.