Blockade of GABA uptake with tiagabine inhibits audiogenic seizures and reduces neuronal firing in the inferior colliculus of the genetically epilepsy-prone rat

Tiagabine is a new anticonvulsant drug that blocks the uptake of GABA, prolonging the action of this inhibitory transmitter. In the present study the effects of systemically administered tiagabine [30 mg/kg, ip (ED50)] were examined on audiogenic seizure (AGS) severity and neuronal firing in the inferior colliculus (IC) in the freely moving genetically epilepsy-prone rat (GEPR-9). The IC is known to be critical to AGS initiation. The effects of focal microinjection of tiagabine into the IC were also examined. Bilateral focal microinjection of tiagabine into the IC significantly reduced seizure severity in the GEPR-9. Systemically administered tiagabine also produced a significant reduction in seizure severity in the GEPR-9. Tiagabine produced a reduction in IC (central nucleus) neuronal firing, which was significant only at high acoustic intensities (90-105 dB), concomitant with the considerable reduction in seizure severity. These data are consistent with enhancement by tiagabine of gamma-aminobutyric acid (GABA)-mediated inhibition in IC, which is most prominent at high acoustic intensities. The time course of the reduction in neuronal firing of IC neurons paralleled the reduction in seizure severity. Previous studies have shown that two forms of GABA-mediated inhibition (intensity-induced and offset inhibition) in IC neurons are most prominent at high stimulus intensities, which are required to induce AGS. The blockade of GABA uptake by tiagabine may act to inhibit audiogenic seizures, in part, by intensifying these naturally occurring forms of acoustically evoked inhibition in inferior colliculus neurons.

Mother-child interactions in ADHD and comparison boys: relationships with overt and covert externalizing behavior

Reciprocal relationships between child characteristics and such familial factors as parental psychopathology and interaction style with the child characterize the development and maintenance of attention-deficit hyperactivity disorder (ADHD) as well as its comorbidity with antisocial behavior. Our goal was to ascertain the ability of negative maternal behavior exhibited during mother-son interactions to predict independently observed overt and covert externalizing behavior in the child, controlling for current maternal symptomatology and the boy's acting out behavior during the interaction. Participants were 49 boys with ADHD and 37 comparison boys, aged 6 to 12 years. Hierarchical multiple-regression analyses revealed that, even with maternal psychopathology and child negativity with the mother partialed, maternal negative behaviors predicted both observed noncompliance exhibited in class and play settings and laboratory stealing. Stealing was predicted from maternal negativity even with child interactional compliance controlled. Differential predictions of noncompliance were revealed in ADHD versus comparison families, yet similar patterns emerged for stealing within each group. Results are discussed in light of the high risk for antisocial behavior in ADHD children.

Behavioral and characterological attributional styles as predictors of depression and loneliness: review, refinement, and test

The literature on self-blame and depression reveals two interrelated problems. First, although R. Janoff-Bulman's (1979) conceptualizations of self-blame are clear, empirical operationalization is difficult and has resulted in approaches that do not capture the richness of the constructs. Second, past research has produced inconsistent findings. A comprehensive literature review revealed that the inconsistencies are related to the method of assessing attributions. A correlational study designed to more accurately represent the self-blame conceptualization revealed that both behavioral and characterological self-blame contribute uniquely to depression and loneliness. Supplementary results regarding circumstantial attributions and regarding attributional styles for success were presented. Empirical issues regarding possible methodological refinements and effect size, as well as the value of categorical approaches to the study of attributional style were discussed.

Management of Pratylenchus penetrans on Oriental Lilies with Drip and Foliar-applied Nematicides

Pratylenchus penetrans is a pest for producers of oriental lilies in northern California. Concern over groundwater contamination from 1,2-dichloropropane following shank injections of 1,3-dichloropropene-l,2-dichloropropane mixture and granular applications of aldicarb prompted testing for alternative methods of controlling P. penetrans. In field trials, nematicides applied by drip irrigation (ethoprop, fenamiphos, oxamyl, sodium tetrathiocarbonate, water extracts of marigold and vetch, and 1,3-D plus emulsifier) were tested with and without foliar applications of oxamyl. Nematode populations were reduced (P = 0.05) relative to controls in soil or roots on one or more sampling dates by all drip-applied nematicides except the plant extracts. On some sampling dates, additional reductions (P = 0.05) occurred as a result of three foliar applications of oxamyl. Foliar-applied oxamyl alone also reduced (P = 0.05) nematodes in soil or roots. Lily bulb weight was not affected (P = 0.05) by chemical treatments.

Refinement of Hot Water Treatment for Management of Aphelenchoides fragariae in Strawberry

The effects of hot water treatments on a California population of the foliar nematode, Aphelenchoides fragariae, and on five strawberry cuttivars ('Chandler', 'Douglas', 'Fern', 'Pajaro', and 'Selva') were assessed in laboratory and greenhouse tests. Nematodes extracted from fern leaves were placed in water maintained at 44.4, 46.1,47.7, or 49.4 C for different time periods. Exposure periods of 15, 5, 4, and 2 minutes were required to produce 100% mortality at 44.4, 46.1, 47.7, and 49.4 C, respectively. In a water bath, 4 minutes were required for strawberry crowns initially at 25 C to equilibrate with temperatures ranging from 44.4-54.4 C. The maximum exposure periods that did not significantly reduce subsequent plant growth and flowering were 30, 15, and 10 minutes, at 44.4, 46.1, and 47.7 C, respectively. Survival of Selva was lower (P = 0.05) than for the other cultivars. Treatment at 49.4 C for 5 minutes significantly reduced plant growth and flowering of all cultivars. The minimum-maximum exposure periods that killed A. fragariae without damaging the cultivars tested were 20-30 minutes at 44.4 C, 10-15 at 46.1 C, or 8-10 at 47.7 C.

Evaluation of Hot Water Treatments for Management of Ditylenchus dipsaci and Fungi in Daffodil Bulbs

Treatment of daffodil (Narcissus pseudonarcissus) bulbs in a 0.37% formaldehyde water solution at 44 C for 240 minutes is a standard practice in California for management of the stem and bulb nematode, Ditylenchus dipsaci. Recent concern over the safety of formaldehyde and growers' requests for a shorter treatment time prompted a reevaluation of the procedure. The time (Y, in minutes) required to raise the temperature at the bulb center from 25 to 44 C was related to bulb circumference (X, in cm) and is described by the linear regression Y = -15 + 3.4X. The time required for 100% mortality of D. dipsaci in vitro without formaldehyde was 150, 60, and 15 minutes at 44, 46, and 48 C, respectively. Hot water treatment (HWT) with 0.37% formaldehyde at 44 C for 150 minutes controlled D. dipsaci and did not have a detrimental effect on plant growth and flower production. Shorter formaldehyde-HWT of 90, 45, and 30 minutes at 46, 48, and 50 C, respectively, controlled D. dipsaci but suppressed plant growth and flower production. Fungal genera commonly isolated from the bulbs in association with D. dipsaci were Penicillium sp., Fusarium oxysporum f. sp. narcissi, and Mucor plumbeus, representing 60, 25, and 5%, respectively, of the total fungi isolated. These fungi caused severe necrosis in daffodil bulbs. HWT at 44 C for 240 minutes reduced the number of colonies recovered from bulbs. The effects of formaldehyde, glutaraldehyde, and sodium hypochlorite in reducing the population of fungi within bulbs were variable. Satisfactory control of D. dipsaci within bulbs can be achieved with HWT of bulbs at 44 C for 150 minutes with 0.37% formaldehyde or at 44 C for 240 minutes without chemicals.

Chronic leukotriene inhibition in the rat fails to modify the toxicological effects of a cyclooxygenase inhibitor

A 5-week study was carried out in rats using a leukotriene biosynthesis inhibitor (MK-886; 3-[1-(4-chlorobenzyl)-3-t-butylthio-5-isopropylindol-2-yl]-2,2- dimethylpropanoic acid) at a dose of 300 mg.kg-1 x day-1, this being sufficient to produce > 90% inhibition of ex vivo leukotriene B4 synthesis in rat blood, and a cyclooxygenase inhibitor (indomethacin, 4 and 6 mg.kg-1 x day-1) to ascertain whether inhibition of leukotriene biosynthesis would potentiate or inhibit the toxicity associated with the administration of nonsteroidal anti-inflammatory drugs (NSAIDs), in particular the gastrointestinal damage. Treatment with indomethacin alone or in combination with MK-886 resulted in the toxicity normally associated with NSAIDs, including gastrointestinal lesions. No toxicity was associated with the administration of MK-886 alone, and MK-886 had no significant effect on the incidence of gastrointestinal lesions produced by indomethacin. These results indicate that leukotrienes are not significant mediators of NSAID-induced gastroenteropathy in the rat.

Stimulation or blockade of the dorsal nucleus of the lateral lemniscus alters binaural and tonic inhibition in contralateral inferior colliculus neurons

Recent studies have demonstrated that several specific types of acoustically-evoked GABA-mediated inhibition occur in neurons of the central nucleus of inferior colliculus (ICc). The dorsal nucleus of the lateral lemniscus (DNLL) provides a major GABAergic projection to ICc. The present study examined the effects of electrical or chemical stimulation or reversible blockade within the DNLL on the discharge characteristics of ICc neurons in anesthetized rats. Microinjection of a local anesthetic (lidocaine) or a GABA-A agonist (THIP) via a cannula placed into DNLL reversibly blocked acoustically-evoked binaural inhibition and increased spontaneous firing in most contralateral ICc neurons. Trains of electrical pulses or microinjection of the excitant amino acid, kainate, into DNLL resulted in reduced acoustically-evoked firing, which was similar to binaural inhibition, in most contralateral ICc neurons examined. The effects of DNLL electrical stimulation were reversibly blocked by microinjection of THIP into the stimulation site, suggesting that the effect of the electrical stimulation is mediated by direct effects on cell bodies of DNLL neurons. These data support the idea that contralateral GABAergic input from the DNLL is inhibitory to ICc neurons. Thus, binaural inhibition and tonic inhibition in ICc neurons may be mediated, in part, by the GABAergic projection from the contralateral DNLL.

Psychosocial outcomes of children of unipolar depressed, bipolar, medically ill, and normal women: a longitudinal study

The psychosocial functioning of children of unipolar depressed, bipolar, medically ill, and psychiatrically normal women was studied over a 2-year period. Ninety-six children aged 8-16 years were assessed at 6-month intervals on Child Behavior Checklist behavior problems, social competence, internalizing and externalizing behaviors, academic performance, and school behavior. The children of unipolar mothers showed significantly poorer functioning on all measures as compared with the other 3 groups of children, including bipolar offspring. A greater proportion of children in the unipolar group also had relatively chronic, clinically significant problems in psychosocial functioning. Children of bipolar women did not differ from children of psychiatrically normal women. Results are discussed in terms of the consequences of children's continuing exposure to maternal depression and attendant stressors, as well as the contribution of social and academic difficulties to a vicious cycle of maladjustment.

Critical developmental periods for effects on male rat genitalia induced by finasteride, a 5 alpha-reductase inhibitor

The conversion of testosterone to 5 alpha-dihydrotestosterone by the enzyme 5 alpha-reductase is inhibited by finasteride. In a study in which maternal dosing with finasteride commenced on Gestational Day 15 and terminated on Postpartum Day 21, there were 13 and 27% decreases in anogenital distance of male pups on Postnatal Day 1 at 0.03 and 3 mg/kg/day, respectively. These decreases were largely reversed by Postnatal Day 22 even though treatment of the dams continued. Treatment at 3 mg/kg/day also resulted in hypospadias with cleft prepuce and a 5-day delay in the separation of the prepuce from the glans penis in those animals without hypospadias. A second study in which 20 mg/kg/day finasteride was administered on successive 2-day periods during late gestation in rats demonstrated that the period of Gestational Days 16 to 17 was the most sensitive (critical period) for finasteride-induced hypospadias, cleft prepuce, decreased anogenital distance, reduced prostate weight, and nipple formation in F1 male offspring. This critical period is just prior to the appearance on Day 18 of gestation of a midline mesenchymal plate between the urogenital sinus and the rectum in normal male fetuses. This midline plate does not appear in finasteride-exposed fetuses destined to have hypospadias as demonstrated in a previous study. Based on these observations, we hypothesize that finasteride causes hypospadias by preventing the formation of the medial mesenchymal plate which is necessary for assisting the movement of the urogenital sinus from the base to the tip of the genital tubercle.

Laparoscopic colostomy closure

Perforated sigmoid diverticulitis often results in the patient undergoing a sigmoid resection, closure of the rectal stump, and an end sigmoid colostomy. To reestablish intestinal continuity, the patient must undergo a second major intra-abdominal operation. We have developed a technique of laparoscopic colostomy closure to reestablish intestinal continuity and have used it in two patients. Because of the reduced operative pain and shorter recovery period, this minimally invasive technique would be a better surgical alternative to colostomy closure.

Management of Plant-parasitic Nematodes with a Chitin-Urea Soil Amendment and Other Materials

Field trials were conducted with a chitin-urea soil amendment and several other nematicides on four crop-nematode combinations: tomato-Meloidogyne incognita; potato-Meloidogyne chitwoodi; walnut-Pratylenchus vulnus; and brussels sprouts-Heterodera schachtii. Significant (P </= 0.10) nematode population reductions were obtained with the chitin-urea soil amendment in the trims on potato and walnut. In the trials on brussels sprouts and on tomato, phytotoxicity occurred at rates of 1,868 and 1,093 kg/ha, respectively. Significant (P </= 0.10) nematode reductions were also obtained with metham sodium on potato; with 1,3-D on tomato and brussels sprouts; and with sodium tetrathiocarbonate, XRM 5053, fenamiphos, ethoprop, LX1075-05, LX1075-07, and SN 109106 on tomato. The following materials did not provide significant nematode control under the conditions of the particular experiments: metham sodium, oxamyl, and Yucca extract on tomato; and dazomet granules on brussels sprouts.

Glutamate in the inferior colliculus plays a critical role in audiogenic seizure initiation

Alterations of excitant amino acid (EAA) action are implicated in seizure susceptibility in the genetically epilepsy-prone rat (GEPR). The inferior colliculus (IC) is critical for audiogenic seizure (AGS) initiation in the GEPR. The present study observed that bilateral microinjection into the IC of L-canaline, a glutamate synthesis inhibitor, decreased AGS severity in the GEPR and also decreased potassium-evoked release of glutamate from IC slices. Bilateral microinjection of NMDA receptor antagonists, 2-amino-7-phosphonoheptanoate (AP7) or 3-((+/-)-2-carboxypiperazin-4-yl)-propyl-1-phosphonate (CPP) into IC blocked AGS, and an antagonist at non-NMDA EAA receptors, 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), also blocked AGS. NMDA receptor antagonists were 5-200 times more effective than CNQX. Microinjection of a non-competitive NMDA receptor antagonist, dizocilpine (MK-801), into IC had little effect except with very high doses. Microinjection of CPP or AP7 into the IC blocked AGS at considerably lower doses as compared to pontine reticular formation (PRF). However, MK-801 attenuated AGS when microinjected into PRF at doses that were ineffective in IC. Systemically administered CPP blocked AGS and significantly reduced IC neuronal firing in the behaving GEPR, suggesting an important action of systemically administered NMDA receptor antagonists on brainstem auditory nuclei critical to AGS. The present results support a critical role for glutamate acting, in part, through NMDA receptors in IC in initiation of AGS.

Takayasu arteritis

Takayasu Arteritis is a vasculitis of the giant cell type which affects young people. Complications of this disease can include myocardial infarction, stroke, limb loss, renal failure, and mesenteric ischemia. A case study demonstrates some of the complexities of diagnosis and treatment for this condition. Nursing care should be directed toward the alteration in tissue perfusion, prevention of infection in a patient on immunosuppressive therapy, and a variety of potential problems with coping.

Reversible effects of triamcinolone and lack of effects with aspirin or L-656,224 on external genitalia of male Sprague-Dawley rats exposed in utero

Inhibitors of the arachidonic acid cascade were given to pregnant rats during the critical period for morphogenesis of the external genitalia. Groups treated subcutaneously (s.c.) with 0.1 or 0.25 mg/kg/day of triamcinolone acetonide (TA) on gestational days (GD) 14-19 had male fetuses on GD 20 with moderate decreases in absolute anogenital distance (AGD), but gross and histological examinations revealed no alterations to the genital tubercle (i.e., no hypospadias). The s.c. coadministration of arachidonic acid at 100 mg/kg/day had minimal to no effect on AGD in the TA-exposed groups. No effect on AGD was observed in male fetuses from groups administered aspirin orally at 150 mg/kg/day, and only a 6% decrease was observed in the 300-mg/kg/day group. Neither TA nor aspirin adversely affected AGD of female fetuses. In another study, TA was administered on GD 11-19 at dose levels of 0.05 and 0.1 mg/kg/day, and dams were allowed to deliver. High-dose male offspring examined on postcoitum day (PCD) 23, had moderate decreases in AGD. In both studies with TA, there were also significant decreases in offspring weights. The contribution of the decreased weight to the decrease in absolute AGD was examined by a variety of methods (ratio of AGD to cube root of weight or biparietal distance, comparison to weight-matched controls, and covariance analysis). We conclude that TA caused a specific decrease in AGD on GD 20 that was largely reversed by PCD 23. When examined as adults (8 weeks old), the external genitalia of TA-exposed offspring were normal. Thus, the TA-induced decreases in AGD on GD 20 did not predict irreversible malformation. TA also caused other effects, which included a somewhat flattened genital tubercle and apparently thinned and glossy skin between the tubercle and the anus in both sexes on GD 20 and PCD 23, but not as adults. In addition, there were high pup mortality and high incidences of micrognathia and omphalocele (in the 0.25-mg/kg/day group only). Aspirin at 75 or 150 mg/kg/day and a specific lipoxygenase inhibitor (L-656,224) at 1,000 or 2,000 mg/kg/day were also administered from GD 14 to 19, and no offspring effects were observed. Thus, of the three agents that potentially inhibit the arachidonic acid cascade, only triamcinolone produced moderate effects on rat external genitalia that were largely reversible.(ABSTRACT TRUNCATED AT 400 WORDS)

Management of Ditylenchus dipsaci in Daffodils with Foliar Applications of Oxamyl

Ditylenchus dipsaci (Kühn) Filipjev is a serious pest of commercial daffodil (Narcissus sp.) in northern California. The control measures practiced by growers in recent years are postharvest treatment of planting bulbs for 3 hours in a 1% solution of formalin at 44 C combined with preplant soil fumigation with 1,3-dicbloropropene and (or) at-planting applications of phorate. In field trials, several combinations of rates (1.12, 2.24, or 4.48 kg a.i./ha in 189 liters of water/ha) and timings (one, two, or three applications at weekly intervals) of foliar applications with oxamyl on three daffodil varieties (Fortune, Ice Folley, and King Alfred) were evaluated as alternatives. Several treatments reduced nematode levels in leaves and bulbs. Phytotoxicity was not observed at any rate or combination of treatments.

Implementing continuous quality improvement (CQI) in hospitals: lessons learned from the International Quality Study

Continuous Quality Improvement is in the process of being implemented in hospitals around the world. In an attempt to gain a better understanding of the "best management practices" the International Quality Study is being conducted in four countries--Canada, Germany, Japan and the United States--and across four industries--Health Care, Banking, Automotive and Computers. Information collected through a survey process will be analysed through causal modeling to determine correlations between management practices and achievement of quality objectives. Given both the complexity of the models and the number of key concepts involved, 400 hospitals have been invited to participate. The preliminary results show direct correlations between cultural influences and the concept of quality. The perceived definition of quality by the various countries varies and therefore the application of "quality concepts" differs. Once complete, this database of "best management practices" will serve as a worldwide benchmark for quality progress.

Loss of intensity-induced inhibition in inferior colliculus neurons leads to audiogenic seizure susceptibility in behaving genetically epilepsy-prone rats

The genetically epilepsy-prone rat (GEPR) exhibits elevated seizure sensitivity and audiogenic seizures (AGS). The inferior colliculus (IC) is the most critical brain region for AGS initiation. The present study evaluated IC neuronal firing and convulsive behavior simultaneously in freely moving GEPRs. High intensity acoustic stimulation produces neuronal firing reductions (intensity-induced inhibition) in about 50% of IC neurons in normal rats. However, in GEPR IC neurons, intensity-induced inhibition is significantly less effective than normal. Offset inhibition is also reduced in GEPR IC neurons, which leads to a greater than normal incidence of offset (afterdischarge) responses at high stimulus intensities. At AGS onset most IC neurons exhibit burst firing and reductions of acoustically evoked neuronal responses. Responsiveness to acoustic stimuli returns following AGS. This change in IC neuronal firing pattern suggests that the network that governs IC neuronal firing has temporarily changed from the auditory system to the network that mediates seizure propagation. GABA is strongly implicated in intensity-induced, binaural, and offset inhibition in IC neurons. The diminished efficacy of these forms of GABA-mediated acoustically evoked inhibition in the GEPR IC extends previous results, showing reduced effectiveness of exogenously applied GABA and benzodiazepine in GEPR IC neurons. This reduced effectiveness of GABA-mediated inhibition along with excess excitant amino acids in GEPR IC, previously reported, appear to be vital neurotransmitter mechanisms, subserving the exaggerated output of IC neurons at high acoustic intensities. This exaggerated IC firing may be instrumental in seizure initiation in this epilepsy model.