Intrauterine exposure to chorioamnionitis and neuroanatomical alterations at term-equivalent age in preterm infants

PURPOSE

Infants born to mothers with chorioamnionitis (CAM) are at increased risk of developing adverse neurodevelopmental disorders in later life. However, clinical magnetic resonance imaging (MRI) studies examining brain injuries and neuroanatomical alterations attributed to CAM have yielded inconsistent results. We aimed to determine whether exposure to histological CAM in utero leads to brain injuries and alterations in the neuroanatomy of preterm infants using 3.0- Tesla MRI at term-equivalent age.

METHODS

A total of 58 preterm infants born before 34 weeks of gestation at Nagoya University Hospital between 2010 and 2018 were eligible for this study (CAM group, n = 21; non-CAM group, n = 37). Brain injuries and abnormalities were assessed using the Kidokoro Global Brain Abnormality Scoring system. Gray matter, white matter, and subcortical gray matter (thalamus, caudate nucleus, putamen, pallidum, hippocampus, amygdala, and nucleus accumbens) volumes were evaluated using segmentation tools (SPM12 and Infant FreeSurfer).

RESULTS

The Kidokoro scores for each category and severity in the CAM group were comparable to those observed in the non-CAM group. White matter volume was significantly smaller in the CAM group after adjusting for covariates (postmenstrual age at MRI, infant sex, and gestational age) (p = 0.007), whereas gray matter volume was not significantly different. Multiple linear regression analyses revealed significantly smaller volumes in the bilateral pallidums (right, p = 0.045; left, p = 0.038) and nucleus accumbens (right, p = 0.030; left, p = 0.004) after adjusting for covariates.

CONCLUSIONS

Preterm infants born to mothers with histological CAM showed smaller volumes in white matter, pallidum, and nucleus accumbens at term-equivalent age.

Underlying Disorders in Children With Infection-Related Acute Encephalopathy

BACKGROUND

Various factors contribute to the development of infection-related acute encephalopathy (AE) in children, such as infectious agents and chronic underlying disorders. We studied underlying disorders in children with AE to identify predisposing factors of AE.

METHODS

We investigated underlying disorders or past histories in patients with two types of AE from the database in the Tokai area of Japan between 2009 and 2022: 204 patients with AE with reduced subcortical diffusion (AED) and 137 with clinically mild encephalopathy with a reversible splenial lesion (MERS). We compared them with 89 patients with acute disseminated encephalomyelitis (ADEM) to clarify the specific disorders in the two AE types.

RESULTS

The prevalence of underlying disorders in AED (34%, 70 patients) was significantly higher than that in ADEM (12%, 11 patients) (P < 0.01). The prevalence of underlying disorders in MERS was 23% (32 patients). The underlying disorders included seizure disorders, premature birth, genetic/congenital disorders, and endocrine/renal diseases. In patients with seizure disorders in AED, five patients (18%) had Dravet syndrome and four (15%) had West syndrome, whereas none with MERS had these syndromes. Twenty-five (12%) of 204 patients with AED, three (2%) with MERS, and one (1%) with ADEM were preterm or low birth weight.

CONCLUSIONS

The high prevalence of seizure disorders suggests that seizure susceptibility is an important predisposing factor in AED. Premature birth also has an impact on the development of AED. Caution is required regarding the development of AE in patients with chronic seizure disorders or premature birth.

Two Cases of Juvenile Myelomonocytic Leukemia and Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease

BACKGROUND

Myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) is an autoimmune demyelinating disorder that often manifests after infections or vaccinations. We report two patients who developed MOGAD out of eight patients with juvenile myelomonocytic leukemia (JMML) that has never been reported.

METHODS

We investigated two patients with JMML who developed MOGAD among 127 patients with leukemia from 2012 to 2021.

RESULTS

Patient 1 was treated for JMML and developed fever and impaired consciousness at two years and one month of age. Magnetic resonance imaging revealed high-intensity lesions in the left frontal and left occipital white matter. The serum anti-MOG antibody test was positive, while the test was negative in the stored serum 45 days before the onset of encephalopathy. He had relapse of MOGAD after steroid therapy and plasmapheresis. Patient 2, who was treated for JMML, became apathetic and mute at three years and seven months of age. Magnetic resonance imaging revealed left frontoparietal subcortical high-intensity lesions. Anti-MOG antibody at the onset of encephalopathy was positive, while it was negative in stored serum 57 days before and 47 days after the onset.

CONCLUSION

We treated two patients who developed MOGAD out of eight patients with JMML and none with MOGAD out of 119 patients with acute lymphocytic leukemia, acute myelocytic leukemia, or chronic myelocytic leukemia. The activated autoimmune process via the RAS pathway abnormality may have led to the formation of the anti-MOG antibody and the onset of MOGAD. MOGAD can occur in children with JMML, and abnormalities of the RAS pathway possibly contribute to its onset.

Angelman syndrome with mosaic paternal uniparental disomy suggestive of mitotic nondisjunction

Angelman syndrome (AS) is caused by the functional absence of the maternal ubiquitin-protein ligase E3A (UBE3A) gene. Approximately 5% of AS is caused by paternal uniparental disomy of chromosome 15 (UPD(15)pat), most of which is considered to result from monosomy rescue. However, little attention has focused on how UPD(15)pat occurs. We suggest the mitotic nondisjunction mechanism as a cause of UPD(15)pat in a six-year-old patient presenting with distinctive characteristics in line with AS. DNA methylation screening of 15q11-q13 showed a paternal band and a faint maternal band, suggestive of mosaic status. By trio-based microsatellite analysis, we confirmed a large proportion of UPD(15)pat cells and a small proportion of cells of biparental origin. Single nucleotide polymorphism (SNP) microarray revealed isodisomy of the entire chromosome 15. These results suggest that the UPD(15)pat of the patient resulted from mitotic nondisjunction, which may also be the cause of other cases of AS with UPD(15)pat.

The DPP4 inhibitor linagliptin exacerbated heart failure due to energy deficiency via downregulation of glucose absorption and utilization in mice

Background

It was reported that glucagon-like peptide-1 has cardio-protective effects, however, the occurrence of heart failure was increased with DPP4 inhibitor in some large clinical trials.

Purpose

The purpose of the present work was to clarify whether DPP4 inhibitor had any effects on chronic, dilated heart failure and to identify the mechanisms.

Methods

Heart / Muscle-specific Manganese superoxide dismutase (Mn-SOD)-deficient mice, (H/M-Sod−/−) which exert dilated cardiomyopathy were randomized to receive low dose (1 mg/kg) linagliptin, HF-L group; high dose (10 mg/kg) linagliptin, HF-H group; mixed with food, or normal food, HF group; for eight weeks. Then, evaluation was performed in cardiac function and pathophysiological changes.

Result

Interestingly, the mice treated with linagliptin treatment exhibited shorter life span and greater heart/body weight ratio. Echocardiographic studies showed decreased contractility in the HF-H group with compared to the HF control group. In Sirius Red staining, severer fibrosis was also observed in the linagliptin groups. HbA1c levels did not change among three groups, however, glycogen content in the liver was significantly decreased in the linagliptin groups. Similarly, indirect calorimetry showed decreased carbohydrate consumption in the HF-H group compared to the HF control group, suggesting worsening of heart failure was due to unavailability of carbohydrates as an energy source. Therefore, we fed a diet containing 33 wt% glucose to the HF-H group as complementary experiments. As a result, adequate glucose supplementation reduced cardiac fibrosis and cardiac function, while worsened life span, HbA1c levels and CHO consumption were not changed. Therefore, we hypothesized that there might be a change in the absorption of glucose in intestine or utilization ability of glucose in body another experiments were performed. 13C, which was released from mice after the oral administration of 13C glucose and measured by respiratory gas analysis, was significantly reduced in HF-H mice. The measurements the amount of 13C in feces revealed increased levels of unabsorbed glucose by linagliptin treatment in HF. In addition, GLUT2, a glucose transporter, in small intestine, was downregulated in the HF-H and the HF-HG groups. On the other hand, the cardiac uptake of Deoxy-D-glucose, 2-[1,2-3H(N)] (3H-2DG), which was injected from mice tail vein, was not different between in the HF-H group and in the HF control group. Taken together, linagliptin treatment may inhibit glucose transport in intestine in HF.

Conclusions

Linagliptin treatment exacerbated heart failure, resulting in shortened life span, worsened cardiac function, and fibrosis of the myocardium. DPP4 inhibitor may promote the cardiac cachexia and exacerbate heart failure at least, in part, through modification of glucose absorption and utilization.

Funding Acknowledgement

Type of funding sources: None.

Whole-exome analysis of 177 pediatric patients with undiagnosed diseases

Recently, whole-exome sequencing (WES) has been used for genetic diagnoses of patients who remain otherwise undiagnosed. WES was performed in 177 Japanese patients with undiagnosed conditions who were referred to the Tokai regional branch of the Initiative on Rare and Undiagnosed Diseases (IRUD) (TOKAI-IRUD). This study included only patients who had not previously received genome-wide testing. Review meetings with specialists in various medical fields were held to evaluate the genetic diagnosis in each case, which was based on the guidelines of the American College of Medical Genetics and Genomics. WES identified diagnostic single-nucleotide variants in 66 patients and copy number variants (CNVs) in 11 patients. Additionally, a patient was diagnosed with Angelman syndrome with a complex clinical phenotype upon detection of a paternally derived uniparental disomy (UPD) [upd(15)pat] wherein the patient carried a homozygous DUOX2 p.E520D variant in the UPD region. Functional analysis confirmed that this DUOX2 variant was a loss-of-function missense substitution and the primary cause of congenital hypothyroidism. A significantly higher proportion of genetic diagnoses was achieved compared to previous reports (44%, 78/177 vs. 24-35%, respectively), probably due to detailed discussions and the higher rate of CNV detection.

Trajectory of the incidence of brushes on preterm electroencephalogram and its association with neurodevelopment in extremely low birth weight infants

BACKGROUND

Brush or delta brush is a well-known characteristic waveform in preterm electroencephalograms. However, the longitudinal trajectory of brushes and its association with neurodevelopment remain uncertain.

METHODS

We analyzed the longitudinal incidence of brushes in 36 extremely low birth weight infants without severe brain lesions and its association with neurodevelopment and white matter abnormality. Conventional eight-channel electroencephalograms were recorded at 30, 32, 36, and 40 postmenstrual weeks (PMW). Incidence of brushes was calculated as the sum of brushes from each channel separated by active sleep and quiet sleep. A developmental delay was defined as a developmental quotient of <85 assessed at corrected age of 18 months. White matter abnormalities were evaluated with term-equivalent magnetic resonance imaging.

RESULTS

The median incidence of brushes (per minute) in 36 infants at PMW 30, 32, 36, and 40 was 16.4, 20.4, 22.5, and 1.8 during active sleep and 7.5, 10.3, 11.5, and 1.7 during quiet sleep, respectively. Among the 36 infants, 14 infants were diagnosed with developmental delay. Longitudinal trajectories of the incidence of brushes were different between the normal and the delayed development groups. Brushes were observed most frequently at 36 PMW in the delayed development group. The incidence of brushes at 36 PMW was significantly correlated with the severity of white matter abnormalities and negatively correlated with the developmental quotient.

CONCLUSION

The incidence of brushes at 36 PMW can be a unique predictor of early neurodevelopment in extremely low birth weight infants without severe brain lesions.

Empagliflozin improves prognosis and energetic properties through modulating mitochondrial function in failing murine hearts

Background/Introduction

Sodium-glucose cotransporter 2 (SGLT2) inhibitors have been reported to have beneficial effects on heart failure in large clinical trials; however, the underlying mechanism is still unclear.

Purpose

The purpose of this study is to elucidate the mechanism of cardioprotective effect of empagliflozin in heart failure.

Methods

Eight-week-old mice deficient in cardiac and skeletal muscle-specific manganese superoxide dismutase, a mouse model of dilated cardiomyopathy (MnSOD-cKO mice), were given food mixed with or without 10 mg/kg empagliflozin for seven weeks and evaluated. Mitochondrial function in the cardiac muscle were measured by a high-resolution respirometer, Oxygraph-2K. Respiratory gas analysis were performed by indirect calorimetry (ARCO 2000) to estimate the energy consumption and energetic substrates.

Results

The survival rate (P=0.015) and cardiac fibrosis (P=0.036) were significantly improved in the empagliflozin group. The capacity of oxidative phosphorylation in cardiac mitochondria was significantly improved by empagliflozin. Blood lactate levels were decreased in the empagliflozin group, indicating that energy such as ATP could be produced without resorting to anaerobic metabolism.

Respiratory gas analysis revealed significant improvement in energy expenditure along with increase in food intake. Respiratory quotient was not different between the two groups, showing the consumption of the carbohydrate to fat rate was not changed by empagliflozin in this study. Ketone levels in blood and HbA1c were neither significantly different between the two groups. Although a moderate amount glucose was excreted in urine in the empagliflozin group (128.3±20.4 mg/day, 0.51±0.08 kcal/day), the available energy substrates in the whole body nonetheless expanded because of the increased caloric intake (10.58±0.72 in control group vs. 13.55±0.08 kcal/day in empagliflozin group, P=0.018).

Conclusion(s)

We have shown that empagliflozin improved myocardial mitochondrial function and increased energy metabolism, which was accompanied by adequate energy intake and uptake, even in heart failure. Empagliflozin decreased myocardial fibrosis and improved prognosis in failing murine hearts through positive energetical properties including mitochondrial function. The finding that empagliflozin modulates cardiac metabolism in a positive way provides a novel mechanism for the cardioprotective effect of SGLT2 inhibitors in heart failure.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Boehringer Ingelheim Empa improved prognosis in HFEmpa improved mitochondrial function

Age estimates from brain magnetic resonance images of children younger than two years of age using deep learning

The accuracy of brain age estimates from magnetic resonance (MR) images has improved with the advent of deep learning artificial intelligence (AI) models. However, most previous studies on predicting age emphasized aging from childhood to adulthood and old age, and few studies have focused on early brain development in children younger than 2 years of age. Here, we performed brain age estimates based on MR images in children younger than 2 years of age using deep learning. Our AI model, developed with one slice each of raw T1- and T2-weighted images from each subject, estimated brain age with a mean absolute error of 8.2 weeks (1.9 months). The estimates of our AI model were close to those of human specialists. The AI model also estimated the brain age of subjects with a myelination delay as significantly younger than the chronological age. These results indicate that the prediction accuracy of our AI model approached that of human specialists and that our simple method requiring less data and preprocessing facilitates a radiological assessment of brain development, such as monitoring maturational changes in myelination.

Initial treatment of seizures in children in an emergency department in rural Japan

OBJECTIVE

Although the initial treatment of childhood seizures is important, treatment within an appropriate time window is often difficult in resource-limited areas. This study examined childhood seizure treatment in a rural area in Japan.

METHODS

We retrospectively investigated children presenting to Nakatsugawa Municipal General Hospital emergency department between 2015 and 2018. From the hospital database, we identified children who were diagnosed with seizures, epilepsy, or acute infectious encephalitis/encephalopathy or were given benzodiazepines. We considered etiology, seizure duration, and treatment according to the specialties of the doctors providing initial care.

RESULTS

We extracted 236 seizure events: 40 initially treated by pediatricians, 16 by a mobile doctor team, and 180 by other doctors. Twenty patients had continuous seizures for longer than 5 min on admission. Two were treated by pediatricians at presentation; it took 4 and 7 min after arrival to stop the seizures. Four were treated by a mobile team, and 14 by other doctors; the median response times were 11.5 (range 3-47) and 19 (range 5-60) min, respectively. All patients treated by pediatricians or mobile doctor teams received intravenous or intramuscular diazepam, whereas 50% of those treated by other doctors initially received diazepam suppositories. In three of the 20 events, establishing intravenous access was difficult.

SIGNIFICANCE

In rural Japan, many children with seizures are initially treated by doctors other than pediatricians or emergency physicians, and they require a longer time to achieve seizure cessation. Non-intravenous benzodiazepine formulas, which have not yet been approved in Japan, would be helpful.

MRI findings in children with congenital cytomegalovirus infection retrospectively diagnosed with dried umbilical cord

PURPOSE

Brain MRI provides important information about suspected congenital CMV infection in neonatally underdiagnosed children. This study aimed to describe MRI findings in children in whom congenital CMV infection was not suspected during the neonatal period and was proven retrospectively.

METHODS

We enrolled 31 children referred to the pediatric neurology clinic with neurological symptoms who were proven to have congenital CMV infection based on dried umbilical cord samples. Upon diagnosis, MR and CT images were assessed using the van der Knaap scoring system integrated with additional variables. Two investigators independently assessed all images.

RESULTS

The age at diagnosis was < 12 months in 14, 12-24 months in 11, and > 24 months in 6 patients. The initial symptom triggering clinic referral was delayed development in 22, seizure in 5, deafness in 3, and hemiplegia in 1 patient. Of the 31 children, 30 had a white matter (WM) abnormality predominant in the deep WM of the parietal lobe (n = 25). Anterior temporal lesions were observed in 21 children. Cortical lesions were observed in 7 children, suggestive of polymicrogyria. No child had cerebellar or brainstem abnormalities. Brain CT was performed in 22 of 31 children, and 11 showed punctate cerebral calcification in the periventricular and/or deep WM.

CONCLUSION

Patients with congenital CMV infection with delayed neurological symptoms show a relatively uniform pattern of parietal-dominant multifocal WM lesions and anterior temporal lesions, with or without polymicrogyria.

Expression of protein gene product 9.5 and Sal-like protein 4 in canine seminomas

The aim of the present study was to characterize canine classical seminoma (SE) and spermatocytic seminoma (SS) by immunohistochemical expression of gonocytic and spermatogonial cellular markers (c-Kit, placental alkaline phosphatase [PLAP], protein gene product 9.5 [PGP9.5] and Sal-like protein 4 [Sall4]) and histochemically by the periodic acid-Schiff (PAS) reaction. Twenty-five cases of SE and 23 cases of SS were investigated. Two cases of dysgerminoma were also examined. c-Kit was expressed on the cell membrane of 13 of 25 cases of SE (52%) and four of 23 cases of SS (16%). This marker was not expressed in dysgerminoma. PLAP immunoreactivity was observed in the cytoplasm of neoplastic cells of six of 25 cases of SE (24%). PLAP was not expressed in cases of SS and dysgerminoma. All samples of SE, SS and dysgerminoma showed cytoplasmic expression of PGP9.5 and nuclear immunoreactivity for Sall4. There was fine granular cytoplasmic PAS staining in neoplastic cells in five of 25 cases of SE (20%), while all samples of SS and dysgerminoma cases were PAS negative. These findings suggest that it is not possible to differentiate canine SE and SS using these markers. This may be because canine SS may be derived from spermatogonia that can differentiate to spermatocytes and also because cases of canine SE might consist of neoplastic cells that have lost their gonocytic nature. This study was the first to show positive immunoreactivity for Sall4 in canine seminomas and dysgerminomas and expression of PGP9.5 in canine dysgerminomas.

Low-grade myofibroblastic sarcoma of the maxillary region in a dog

A subcutaneous tumour was identified in the maxillary region of a 14-year-old mixed breed dog. This tumour had grown rapidly over 2 weeks. Microscopically, the tumour had ill-defined borders and was composed of bundles and whorls of atypical spindle cells accompanied by abundant collagen fibres. Immunohistochemically, neoplastic cells were immunoreactive for vimentin, α-smooth muscle actin and calponin and negative for S100 protein, von Willebrand factor, desmin and smoothelin. These results suggested that the neoplastic cells were derived from myofibroblasts and that the tumour was a low-grade myofibroblastic sarcoma.

Influence of leukotriene pathway polymorphisms on clinical responses to montelukast in Japanese patients with asthma

WHAT IS KNOWN AND OBJECTIVE

Montelukast, a cysteinyl leukotriene receptor 1 antagonist, is safe and efficacious in patients with asthma. The mechanisms underlying the significant interpatient variability in response to montelukast are not clear but are believed to be, in part, because of genetic variability.

METHODS

To examine the associations between polymorphisms in candidate genes in the leukotriene pathway and outcomes in patients with asthma on montelukast for 4-8 weeks, we evaluated the changes in peak expiratory flow (PEF), forced expiratory volume in 1 s (FEV(1·0) ) and patients' subjective symptom before and after montelukast treatment. DNA was collected from 252 Japanese participants.

RESULTS AND DISCUSSION

Two single-nucleotide polymorphisms (SNPs) in the ALOX5 (rs2115819) and LTA4H (rs2660845) genes were successfully typed. There was no difference between members of the general population (n = 200) and patients (n = 52) in each genotype frequency. Significant associations were found between SNP genotypes in the LTA4H gene and changes in PEF and FEV(1·0) . The PEF and FEV(1·0) responses to montelukast in the A/A genotypes (n = 4) for the LTA4H SNP were significantly higher than those in the G allele carriers (A/G+G/G) (n = 17).

WHAT IS NEW AND CONCLUSION

Despite the small sample size, our results suggest that genetic variation in leukotriene pathway candidate genes contributes to variability in clinical responses to montelukast in Japanese patients with asthma.

Dysfunction of dopamine release in the prefrontal cortex of dysbindin deficient sandy mice: an in vivo microdialysis study

Dystrobrevin binding protein-1 gene (DTNBP1), which encodes dysbindin protein, has been identified as a schizophrenia susceptibility gene. Dysbindin has been shown to contribute to the regulation of exocytosis and formation of synaptic vesicles. Although hypofrontality in schizophrenia underlies its pathophysiology, the molecular function of dysbindin in synaptic neurotransmission remains unclear. In the present study, we investigated depolarization-evoked dopamine (DA) and serotonin (5-HT) release in the prefrontal cortex (PFC) of sandy (sdy) mice, which have a deletion mutation in the gene encoding DTNBP1. In vivo microdialysis analysis revealed that extracellular DA levels in the PFC of wild-type mice were increased by 60mM KCl stimulation, and the KCl-evoked DA release was significantly decreased in sdy mice compared with wild-type mice. Extracellular 5-HT levels in the PFC of wild-type mice were also increased by 60mM KCl stimulation. The KCl-evoked 5-HT release did not differ between wild-type and sdy mice. There was no difference in basal levels of DA and 5-HT before the stimulation between two groups. Behavioral sensitization after repeated methamphetamine (METH) treatment was significantly reduced in sdy mice compared with wild-type mice whereas no difference was observed in METH-induced hyperlocomotion between two groups. These results suggest that dysbindin may have a role in the regulation of depolarization-evoked DA release in the PFC and in the development of behavioral sensitization induced by repeated METH treatment.

Role of Ca2+ mobilization and Ca2+ sensitization in 8-iso-PGF 2 alpha-induced contraction in airway smooth muscle

BACKGROUND

Isoprostanes are prostaglandin (PG)-like compounds synthesized by oxidative stress, not by cyclooxygenase, and increase in bronchoalveolar lavage fluid of patients with asthma. The airway inflammation implicated in this disease may be amplified by oxidants. Although isoprostanes are useful biomarkers for oxidative stress, the action of these agents on airways has not been fully elucidated.

OBJECTIVE

This study was designed to determine the intracellular mechanisms underlying the effects of oxidative stress on airway smooth muscle, focused on Ca(2+) signalling pathways involved in the effect of 8-iso-PGF(2 alpha).

METHODS

Using simultaneous recording of isometric tension and F(340)/F(380) (an indicator of intracellular concentrations of Ca(2+), [Ca(2+)]i, we examined the correlation between tension and [Ca(2+)]i in response to 8-iso-PGF(2 alpha) in the fura-2 loaded tracheal smooth muscle.

RESULTS

Augmented tension and F(340)/F(380) by 8-iso-PGF(2 alpha) were attenuated by ICI-192605, an antagonist of thromboxane A(2) receptors (TP receptors). Moreover, D609, an antagonist of phosphatidylcholine-specific phospholipase C, markedly reduced both the tension and F(340)/F(380) induced by 8-iso-PGF(2 alpha), whereas U73122, an antagonist of phosphatidylinositol-specific phospholipase C, modestly inhibited them by 8-iso-PGF(2 alpha). SKF96365, a non-selective antagonist of Ca(2+) channels, markedly reduced both tension and F(340)/F(380) by 8-iso-PGF(2 alpha). However, diltiazem and verapamil, voltage-dependent Ca(2+) channel inhibitors, modestly attenuated tension although their reduction of F(340)/F(380) was not different from that by SKF96365. Y-27632, an inhibitor of Rho-kinase, significantly attenuated contraction induced by 8-iso-PGF(2 alpha) without reducing F(340)/F(380), whereas GF109203X and Go6983, protein kinase C inhibitors, did not markedly antagonize them although reducing F(340)/F(380) with a potency similar to Y-27632.

CONCLUSION

8-iso-PGF(2 alpha) causes airway smooth muscle contraction via activation of TP receptors. Ca(2+) mobilization by SKF96365- and D609-sensitive Ca(2+) influx and Ca(2+) sensitization by Rho-kinase contribute to the intracellular mechanisms underlying the action of 8-iso-PGF(2 alpha). Rho-kinase may be a therapeutic target for the physiologic abnormalities induced by oxidative stress in airways.

The biological assessment of flora and fauna as standards for changes in the near-shore ocean environment: a study of Barbers Point Harbor

The biological assessments of the flora and fauna in the near-shore ocean environment, specifically Barbers Point Harbor (BPH), demonstrate the usefulness of these biological analyses for evaluation of the changes occurring following man-made excavation for expansion of the harbor. The study included identification and enumeration of macroalgae and dinoflagellates and analyses of herbivores and carnivores in four areas within the perimeter of the harbor and the north and south entrances into the harbor. Numbers of macroalgae varied between 1994 and 1999 surveys, with significant decrease in numbers in stations C, D and E. Stations A and B were similar between 1994 and 1999 with a slight increase in 1999. The significant differences were shown with the appearance of Gambierdiscus toxicus (G toxicus) in 1999 among the algae in stations A and B. Assessment of herbivores and carnivores with the immunological membrane immunobead assay using monoclonal antibody to ciguatoxin and related polyethers demonstrated an increase in fish toxicity among the herbivore from 1994-1999 (22% increase) with a decrease (22%) in non-toxic fish. This was also demonstrated in the carnivores, but to a lesser degree. It is suggested that the biological analyses of the flora and the fauna of the near-shore ocean environment are appropriate to assess the changes that occur from natural and man-made alterations.

Evidence for palytoxin as one of the sheep erythrocyte lytic in lytic factors in crude extracts of ciguateric and non-ciguateric reef fish tissue

The occurrence of palytoxin or its congener in fish extracts has been presented in this study. The presences of hemolytic factors in fish extracts of Hawaiian reef fish and their implication in ciguatera poisoning have been shown by the sheep erythrocyte assay. By use of the anti-palytoxin inhibition assay with fish extracts and sheep red blood cell (RBC), it was shown that palytoxin was one of the major factors in the lysis of sheep erythrocytes. Ouabain, an antagonist of palytoxin for the Na+/K+ ATPase receptor on RBC, also showed inhibition of sheep RBC lysis by fish extracts. From these results, it was concluded that, in part, palytoxin and other palytoxin-related, hemolysin-like factors in fish extracts were responsible for sheep cell hemolysis.

The relationship of DNA ploidy to chromosomal instability in primary human colorectal cancers

The aim of this investigation was to corroborate the relationship between DNA ploidy and chromosomal variation in surgically removed colorectal cancers. For 101 specimens from 21 advanced colorectal cancers, the numerical variations in chromosomes 7, 17, and 18 among cells were measured by fluorescence in situ hybridization using DNA probes specific for centromere of each chromosome, and DNA ploidy was determined by laser scanning cytometry or flow cytometry. DNA diploidy (DNA index = 1.0) was linked with minor variation in copy number of chromosomes 7, 17 and 18, whereas DNA aneuploidy (DNA index > or = 1.2) was found exclusively in tumors with large variations in centromere copy number for all chromosomes. There was a significant difference in the degree of intercellular variations in chromosome copy number between diploid and aneuploid clones for all chromosomes examined (P < 0.001). In near-diploid clones (1.0 < DNA index < 1.2), the numerical variation of chromosome 18 was significantly different from that in diploid clones (P < 0.002), but it was not different from that in aneuploid clones. These observations support the hypothesis that chromosomal instability is associated with DNA aneuploidy in colorectal cancers. Additionally, they suggest that near-diploid tumors are also unstable at a lower level than classic aneuploid tumors and that all chromosomes are not affected equally in near-diploid cases.