Summertime blues. Summer's common emergencies.
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Bites and Stings↗
Biomedical subjects
R Ball
Publications and source records attributed to R Ball.
Dimensions of the Beck Depression Inventory-II in clinically depressed outpatients.
To ascertain the dimensions of the Beck Depression Inventory-II (BDI-II; Beck, Steer, & Brown, 1996) in clinically depressed outpatients, exploratory factor analyses were performed with the BDI-II responses of 210 adult (> or =18 years) outpatients who were diagnosed with DSM-IV depressive disorders. Two factors representing Somatic-Affective and Cognitive dimensions were found whose compositions were comparable to those previously reported by Beck, Steer, and Brown (1996) for psychiatric outpatients in general. A subsequent confirmatory factor analysis supported a model in which the BDI-II reflected one underlying second-order dimension of self-reported depression composed of two first-order factors representing cognitive and noncognitive symptoms. The clinical utility of using subscales based on these two latter first-order symptom dimensions was discussed.
Adolescent↗
Developmental regulation of glutamate transporters and glutamine synthetase activity in astrocyte cultures differentiated in vitro.
Glutamate plays an important role in brain development, physiological function, and neurodegeneration. Astrocytes control synaptic concentration of glutamate via the high affinity glutamate transporters, GLT-1 and GLAST, and the glutamate catabolizing enzyme, glutamine synthetase. In this study we show that astrocytes cultured from rat brain in various stages of development including embryonic (E18), postnatal (P1-P21) and mature (P50), show distinct patterns of GLT-1 and GLAST expression, glutamine synthetase activity, and phenotypic changes induced by dibutyryl-cyclic adenosine monophosphate. The transcripts for GLT-1 message were detectable in embryonic astrocytes only, whereas the GLAST message was highly expressed in E18 and P1-P4 astrocyte cultures, declined in P10-P21, and was undetectable in P50 astrocytes. Uptake of 3H-glutamate correlated well with GLAST expression in astrocyte cultures of all developmental stages. Glutamine synthetase activity significantly declined from high embryonic levels in P4 astrocytes and remained low throughout postnatal maturation. Exposure of astrocyte cultures to the differentiating agent, db-cAMP (250-500 microM; 6 days), resulted in a pronounced stellation, up-regulation of GLT-1 and GLAST in E18, and GLAST in P4 cultures, while it was ineffective in P10 astrocytes. By contrast, db-cAMP induced a more pronounced stimulation of glutamine synthetase activity (up to 10-fold above basal) in P10 than in E18 cultures (up to 2 times above basal). The differences in expression/inducibility of glutamate transporters and glutamine synthetase observed in astrocyte cultures derived from various stages of fetal and postnatal development suggest that astrocytes in vivo might also respond differently to environmental or injurious stimuli during development and maturation.
ATP-Binding Cassette Transporters↗
Multiple microvascular and astroglial 5-hydroxytryptamine receptor subtypes in human brain: molecular and pharmacologic characterization.
Physiologic and anatomic evidence suggest that 5-hydroxytryptamine (5-HT) neurons regulate local cerebral blood flow and blood-brain barrier permeability. To evaluate the possibility that some of these effects occur directly on the blood vessels, molecular and/or pharmacologic approaches were used to assess the presence of 5-HT receptors in human brain microvascular fractions, endothelial and smooth muscle cell cultures, as well as in astroglial cells which intimately associate with intraparenchymal blood vessels. Isolated microvessels and capillaries consistently expressed messages for the h5-HT1B, h5-HT1D, 5-HT1F, 5-HT2A but not 5-HT7 receptors. When their distribution within the vessel wall was studied in more detail, it was found that capillary endothelial cells exhibited mRNA for the h5-HT1D and for the 5-HT7 receptors whereas microvascular smooth muscle cells, in addition to h5-HT1D and 5-HT7, also showed polymerase chain reaction products for h5-HT1B receptors. Expression of 5-HT1F and 5-HT2A receptor mRNAs was never detected in any of the microvascular cell cultures. In contrast, messages for all 5-HT receptors tested were detected in human brain astrocytes with a predominance of the 5-HT2A and 5-HT7 subtypes. In all cultures, sumatriptan inhibited (35-58%, P < .05) the forskolin-stimulated production of cyclic AMP, an effect blocked by the 5-HT1B/1D receptor antagonists GR127935 and GR55562. In contrast, 5-carboxamidotryptamine induced strong increases (> or = 400%, P < .005) in basal cyclic AMP levels that were abolished by mesulergine, a nonselective 5-HT7 receptor antagonist. Only astroglial cells showed a ketanserin-sensitive increase (177%, P < .05) in IP3 formation when exposed to 5-HT. These results show that specific populations of functional 5-HT receptors are differentially distributed within the various cellular compartments of the human cortical microvascular bed, and that human brain astroglial cells are endowed with multiple 5-HT receptors. These findings emphasize the complex interactions between brain serotonergic pathways and non-neuronal cells within the CNS and, further, they raise the possibility that some of these receptors may be activated by antimigraine compounds such as brain penetrant triptan derivatives.
Astrocytes↗
Predicting risk of decompression sickness in humans from outcomes in sheep.
In animals, the response to decompression scales as a power of species body mass. Consequently, decompression sickness (DCS) risk in humans should be well predicted from an animal model with a body mass comparable to humans. No-stop decompression outcomes in compressed air and nitrogen-oxygen dives with sheep (n = 394 dives, 14.5% DCS) and humans (n = 463 dives, 4.5% DCS) were used with linear-exponential, probabilistic modeling to test this hypothesis. Scaling the response parameters of this model between species (without accounting for body mass), while estimating tissue-compartment kinetic parameters from combined human and sheep data, predicts combined risk better, based on log likelihood, than do separate sheep and human models, a combined model without scaling, and a kinetic-scaled model. These findings provide a practical tool for estimating DCS risk in humans from outcomes in sheep, especially in decompression profiles too risky to test with humans. This model supports the hypothesis that species of similar body mass have similar DCS risk.
Algorithms↗
Urologic applications of the holmium laser.
The holmium laser has various urologic applications. It is important for urologic nurses and associates to be familiar with the laser physics and safety recommendations of the holmium laser, as well as to understand the applications and surgical techniques associated with this therapy.
Holmium↗
Sending the right message
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Journal Article↗
Gonadotropin releasing hormone analogue antiandrogen failure secondary to a pituitary adenoma.
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Adenocarcinoma↗
Decompression sickness presenting as forearm swelling and peripheral neuropathy: a case report.
Neurological symptoms after decompression from a dive are usually thought to be manifestations of central nervous system (CNS) decompression sickness (DCS). We present a case of DCS in which neurological symptoms are present but which the clinical findings, magnetic resonance imaging and electroneuromyographic studies suggest were caused by muscle injury and exacerbation of an existing peripheral neuropathy. This finding supports the alternative hypothesis that some neurological symptoms and signs in DCS are due to effects on peripheral nerves rather than the CNS.
Adult↗
4-Heterocyclylpiperidines as selective high-affinity ligands at the human dopamine D4 receptor.
5-(4-Chlorophenyl)-3-(1-(4-chlorobenzyl)piperidin-4-yl)pyrazole (3) was identified from screening of the Merck sample collection as a human dopamine D4 (hD4) receptor ligand with moderate affinity (61 nM) and 4-fold selectivity over human D2 (hD2) receptors. Four separate parts of the molecule have been examined systematically to explore structure-activity relationships with respect to hD4 affinity and selectivity over other dopamine receptors. It was found that the 4-chlorophenyl group attached to the pyrazole is optimal, as is the 4-substituted piperidine. The lipophilic group on the basic nitrogen is more amenable to change, with the optimal group found to be a phenethyl. The aromatic heterocyle can be altered to a number of different groups, with isoxazoles and pyrimidines showing improved affinities. This heterocycle can also be advantageously alkylated, improving the selectivity of the compounds over D2 receptors. It is hypothesized that the conformation around the bond joining the aromatic heterocycle to the piperidine is important for D4 affinity, based on crystal structures of isoxazoles (29 and 30) and on a conformationally constrained compound (28). Putting all the favorable changes together led to the discovery that 5-(4-chlorophenyl)-4-methyl-3-(1-(2-phenylethyl)piperidin-4-yl)iso xazole (36) is a nanomolar antagonist at human dopamine D4 receptors with > 500-fold selectivity over hD2 and > 200-fold selectivity over hD3. Compound 36 is an antagonist of hD4 receptors with good oral bioavailability of 38%, a half life of 2 h, and brain levels 10-fold higher than plasma levels.
Cell Line↗
The efficacy of local anaesthetics administered by general dental practitioners.
AIM: To obtain empirical evidence for the efficacy of local anaesthesia in dentistry. DESIGN: Retrospective analysis of serial administrations of local anaesthesia. METHODS: Dentist and patient evaluations of the success of differing techniques (infiltration and block) of anaesthesia in a variety of general practice procedures. Results were analysed for correlation between dentist and patient using a 5-point scale. RESULTS: Complete data were analysed for 331 administrations. In the hands of experienced dentists over 93% of operations were assessed by both dentist and patient as comfortable or completely comfortable. Dentists were generally able to judge patient comfort (P < 0.001). Administrations requiring repeat injections were less comfortable. Dentists judged infiltration administrations more comfortable than block administrations (P < 0.001), but patient judgements of comfort failed to distinguish between differing techniques at the P < 0.05 level. CONCLUSIONS: Some variations in success rate exist between dentists the most dental procedures under local anaesthetic in general practice were assessed as being comfortable or better by both dentists and patients.
Adult↗
Stimulation of glutamate uptake and Na,K-ATPase activity in rat astrocytes exposed to ischemia-like insults.
The postsynaptic actions of glutamate are rapidly terminated by high affinity glutamate uptake into glial cells. In this study we demonstrate the stimulation of both glutamate uptake and Na,K-ATPase activity in rat astrocyte cultures in response to sublethal ischemia-like insults. Primary cultures of neonatal rat cortical astrocytes were subjected to hypoxia, or to serum- and glucose-free medium, or to both conditions (ischemia). Cell death was assessed by propidium iodide staining of cell nuclei. To measure sodium pump activity and glutamate uptake, 3H-glutamate and 86Rb were both simultaneously added to the cell culture in the presence or absence of 2 mM ouabain. Na,K-ATPase activity was defined as ouabain-sensitive 86Rb uptake. Concomitant transient increases (2-3 times above control levels) of both Na,K-ATPase and glutamate transporter activities were observed in astrocytes after 4-24 h of hypoxia, 4 h of glucose deprivation, and 2-4 h of ischemia. A 24 h ischemia caused a profound loss of both activities in parallel with significant cell death. The addition of 5 mM glucose to the cells after 4 h ischemia prevented the loss of both sodium pump activity and glutamate uptake and rescued astrocytes from death observed at the end of 24 h ischemia. Reoxygenation after the 4 h ischemic event caused the selective inhibition of Na,K-ATPase activity. The observed increases in Na,K-ATPase activity and glutamate uptake in cultured astrocytes subjected to sublethal ischemia-like insults may model an important functional response of astrocytes in vivo by which they attempt to maintain ion and glutamate homeostasis under restricted energy and oxygen supply.
Animals↗
Steroidogenesis-inducing protein, isolated from human ovarian follicular fluid, is a potent mitogen for cell lines derived from ovarian surface epithelial carcinomas.
The majority of human ovarian cancers originate from the surface epithelial (OSE) cells that surround the ovary. The incidence of OSE cancer is correlated with the number of ovulations that occur during fertile life. OSE cells remain quiescent but undergo rapid mitotic activity after ovulation to repair the wound. This increase in mitotic activity following each ovulation may give rise to mutations that make the OSE susceptible to malignant transformation. Steroidogenesis-inducing protein (SIP), a protein isolated from human follicular fluid obtained from hyperstimulated ovaries, is a potent mitogen for several gonadal cells. To investigate the possibility that SIP may be involved in the proliferation of OSE cells, we have studied its effects on DNA synthesis in seven cell lines derived from OSE carcinomas (HEY, MLS, SKA, OW-1, SAU, NIH:OVCAR-3, and Caov-3). The cells were cultured in serum-free medium in the presence of SIP for 18 hr, followed by incubation with [3H]thymidine for 4 hr. The radioactivity incorporated into the DNA was measured. SIP stimulated DNA synthesis in six of the cell lines. HEY, SKA, MLS, and OVCAR3 were most responsive to SIP. Interactions between SIP and other growth factors and cytokines known to be present in follicular fluid (EGF/TGFalpha, TGFbeta, FGF, IGF-1, IL-1beta, and TNFalpha) were also investigated in HEY and SKA cells. EGF/TGFalpha and IGF-1 potentiated the effects of SIP. TGFbeta had no effect on SIP, and/or EGF/TGFalpha stimulated DNA synthesis. Other growth factors which were tested in this study had no effect on DNA synthesis in SKA cells. Dibutyryl cyclic-AMP blocked the effects of SIP on DNA synthesis. We conclude that SIP is a potent mitogen for OSE cell lines and together with TGFalpha and IGF-1 may be involved in the proliferation of normal OSE cells after ovulation. Since SIP is obtained from the preovulatory follicle, it may represent a link between the number of ovulations and the increased incidence of OSE cancers.
Female↗
Glutamate uptake and Na,K-ATPase activity in rat astrocyte cultures exposed to ischemia.
In this study we demonstrate the stimulation of both glutamate uptake and Na,K-ATPase activity in rat astrocyte cultures in response to a sublethal ischemic insult in vitro. To measure sodium pump activity and glutamate uptake, 3H-glutamate and 86Rb were simultaneously added to the cultures in the presence or absence of 2 mM ouabain. Na,K-ATPase activity was defined as ouabain-sensitive 86Rb uptake. Cell death was assessed by exclusion of the vital dye, calcein-AM from cells. Concomitant transient increases (2-3 fold above control levels) in both Na,K-ATPase and glutamate transporter activities were observed in astrocytes after 2-4 hours of ischemia. By contrast, 24 hours of ischemia caused a profound loss of both activities which paralleled significant cell death. The addition of 5 mM glucose to the cells after 4 hours of ischemia prevented the loss of sodium pump activity and glutamate uptake, and rescued astrocytes from the lethal effects of 24 hours of ischemia.
Animals↗
Screening for major depression disorders in medical inpatients with the Beck Depression Inventory for Primary Care.
To ascertain how effective the Beck Depression Inventory for Primary Care (BDI-PC) was for differentiating medical inpatients who were and were not diagnosed with DSM-IV major depression disorders (MDD), this 7-item self-report instrument composed of cognitive and affective symptoms was administered to 50 medical inpatients along with the Depression subscale (HDS) from the Hospital Anxiety and Depression Scale (Zigmond & Snaith, 1983, Acta Psychiatrica Scandinavica, 67, 361-370). The Mood Module from the Primary Care Evaluation of Mental Disorders (Spitzer et al., 1995, Prime-MD instruction manual updated for DSM-IV) was used to diagnose MDD. The internal consistency of the BDI-PC was high (alpha = 0.86), and it was moderately correlated with the HDS (r = 0.62, P < 0.001). The BDI-PC was not significantly correlated with sex, age, ethnicity, or type of medical diagnosis. A BDI-PC cut-off score of 4 and above yielded the maximum clinical efficiency with both 82% sensitivity and specificity rates. The clinical utility of the BDI-PC for identifying medical inpatients who should be evaluated for MDD is discussed.
Adolescent↗
Further evidence for the construct validity of the Beck depression Inventory-II with psychiatric outpatients.
To provide further information about the construct validity of the Beck Depression Inventory-II the inventory was administered to 210 psychiatric outpatients along with Derogatis' SCL 90-R. As hypothesized, the Beck Depression Inventory-II was more positively correlated with scores on the Depression subscale (r = .89) than it was with scores on the Anxiety subscale of the SCL-90-R (r = .71).
Adolescent↗
Geriatric assessment. Special considerations of the over-65 patient.
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Aged↗